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LINDSTROM, L., J. J. AHTIAINEN, J. MAPPES, J. S. KOTIAHO, A. LYYTINEN i R. V. ALATALO. "Negatively condition dependent predation cost of a positively condition dependent sexual signalling". Journal of Evolutionary Biology 19, nr 2 (marzec 2006): 649–56. http://dx.doi.org/10.1111/j.1420-9101.2005.01043.x.
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Kurtz, Joachim, Klaus Reinhold i Leif Engqvist. "Immunosuppression under stress: necessary for condition-dependent signalling?" Trends in Ecology & Evolution 15, nr 10 (październik 2000): 418–19. http://dx.doi.org/10.1016/s0169-5347(00)01969-8.
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David, Patrice, Tracey Bjorksten, Kevin Fowler i Andrew Pomiankowski. "Condition-dependent signalling of genetic variation in stalk-eyed flies". Nature 406, nr 6792 (lipiec 2000): 186–88. http://dx.doi.org/10.1038/35018079.
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Palchevska, O. L., V. V. Balatskyi, L. L. Macewicz i O. O. Piven. "Cardiospecific deletion of β-catenin gene associated with an activity violation of signaling cascades involved in the development of myocardial hypertrophy". Visnik ukrains'kogo tovaristva genetikiv i selekcioneriv 15, nr 2 (28.02.2018): 181–86. http://dx.doi.org/10.7124/visnyk.utgis.15.2.877.
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The aim of our study was to investigate the molecular mechanisms of hypertrophy response under cardiospecific β-catenin haploinsufficiency condition. Materials and methods. Studies were done with β-catenin condtional knockout mice (β-catflox/flox) and α-MHC-Cre-transgenic mice. To induce hypertrophy we used swimming test during 6 weeks. Using western-blot, we have analyzed the level of studied proteins. Results. It has been shown that the β-catenin haploinsufficiency is associated with increased signaling activity of MAPK, PI3-kinase-mTOR-dependent signaling cascades in both: with prolonged physical activity and without it. However, even with an increased activity of this signalling, β-catenin haploinsufficient mice expressed weaker hypertrophic response. Conclusions. The transcriptional activity of β-catenin is necessary for the proper interaction of signaling cascades during heart maturation and adaptation to stress. Keywords: β-catenin, hypertrophy, Wnt-signalling, MAPK signalling, PI3-kinase-mTOR-dependent cascade, PKA-signalling, myocardium.
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Garratt, Michael, i Robert C. Brooks. "Oxidative stress and condition-dependent sexual signals: more than just seeing red". Proceedings of the Royal Society B: Biological Sciences 279, nr 1741 (30.05.2012): 3121–30. http://dx.doi.org/10.1098/rspb.2012.0568.
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The links between fitness, health, sexual signals and mate choice are complex and subject to ongoing study. In 1999, von Schantz et al . made the valuable suggestion that oxidative stress may be an important missing piece of this complex puzzle. Their suggestion has been enthusiastically tested, with over 300 studies citing their paper, but most effort has concerned carotenoid-based (and to a lesser extent melanin-based) visual signals, predominantly in birds and fishes. Today, we know a great deal more about oxidative stress and related physiology, in both a pathological and regulatory sense, than we did in 1999. We revisit von Schantz et al .'s predictions and, more importantly, highlight novel mechanisms that could link oxidative stress with a range of energetically demanding signals, greatly increasing the scope from visual signalling systems that are usually discussed and nearly always tested. In particular, we argue that differences between individuals in their ability to regulate physiology related to oxidative stress may be an important factor influencing the production of sexual signals and the costs that are incurred from investment.
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Runemark, Anna, Bengt Hansson, Marcus Ljungqvist, Mikkel Brydegaard i Erik I. Svensson. "Has the inbreeding load for a condition-dependent sexual signalling trait been purged in insular lizard populations?" Molecular Ecology 22, nr 5 (7.01.2013): 1310–21. http://dx.doi.org/10.1111/mec.12178.
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HEALEY, MO, i MATS OLSSON. "Too big for his boots: Are social costs keeping condition-dependent status signalling honest in an Australian lizard?" Austral Ecology 34, nr 6 (wrzesień 2009): 636–40. http://dx.doi.org/10.1111/j.1442-9993.2009.01968.x.
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Steiger, Sandra, Wolf Haberer i Josef K. Müller. "Social environment determines degree of chemical signalling". Biology Letters 7, nr 6 (8.06.2011): 822–24. http://dx.doi.org/10.1098/rsbl.2011.0457.
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Few studies have attempted to distinguish between cues and signals in the context of chemical communication. A number of chemical substances have been shown to vary with physiological state, such as stage of oestrus cycle, fertility, dominance status or nutritional condition, but little is known about whether this variation is incidental or adaptive. Here, we provide evidence of a substance whose emission varies with breeding state, but is not merely an incidental by-product of physiological state, but rather, an evolved signal. Breeding females of the facultative biparental burying beetle, Nicrophorus vespilloides , release methyl geranate, a substance that helps males to identify breeding status and to distinguish between their female partners and non-breeding intruders. We demonstrate that females respond flexibly to their social environment and emit high amounts of methyl geranate only in the presence of a male partner, i.e. a receiver. In contrast, cuticular hydrocarbons, which also have been shown to change with breeding status, are not modulated and do not differ between single and paired breeding females. Receiver-dependent chemical signalling is expected to evolve when costs are involved in the production or transmission of the signal; such signal modulation might be more common than previously thought.
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Chan, Anita YM, Vernon W. Dolinsky, Carrie-Lynn M. Soltys i Jason RB Dyck. "DISSECTING THE SIGNALLING PATHWAYS INVOLVED IN THEANTI-HYPERTROPHIC EFFECTS OF RESVERATROL". Clinical & Investigative Medicine 31, nr 4 (1.08.2008): 7. http://dx.doi.org/10.25011/cim.v31i4.4796.
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Background: Pathological left ventricular hypertrophy is associated with all-cause mortality; however, effective treatment for this condition is currently lacking. We have shown that activation of AMP-activated protein kinase (AMPK) by resveratrol can inhibit myocardial hypertrophy by decreasing protein synthesis and suppressing nuclear factor ofactivated T-cells (NFAT) activation. However, the mechanism by which resveratrol affects AMPK isunknown. Since LKB1 is the upstream kinase of AMPK, we hypothesize that resveratrol signals via LKB1 toactivate AMPK and it is this signalling pathway that contributes to the anti-hypertrophic effects of resveratrol. Methods: Wildtype (WT), LKB1 null, and AMPK null mouseembryonic fibroblasts (MEFs) were treated with vehicle or 100?M resveratrol for 1 h. Cell lysates were subjected to immunoblot analysis to examine the phosphorylation status of the proteins of interest. NFAT-dependent transcription was also measured in these MEFs using a NFAT-luciferase reporter transgene. Results: While resveratrol treatment increased AMPK phosphorylation in WT MEFs, resveratrol was unable to activate AMPK in LKB1 null MEFs. In addition, resveratrol suppressed NFAT-dependent transcription in WT MEFs, yet failed to inhibit NFAT activity in AMPK null MEFs. Conclusion: These data combined with our previous data suggest that resveratrol signals through LKB1 to activate AMPK and that this activation results in suppressed protein synthesis and reduced NFAT activation. As the development of pathologicalcardiac hypertrophy is dependent on protein synthesis and NFAT activation, inhibition of these two pathways by resveratrol may be an exciting new approach for the treatment of pathological cardiac hypertrophy.
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Galeotti, P., R. Sacchi, M. Fasola, D. Pellitteri Rosa, M. Marchesi i D. Ballasina. "Courtship displays and mounting calls are honest, condition-dependent signals that influence mounting success in Hermann's tortoises". Canadian Journal of Zoology 83, nr 10 (1.10.2005): 1306–13. http://dx.doi.org/10.1139/z05-130.
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Like other terrestrial tortoises, the courtship behaviour of Hermann's tortoises (Testudo hermanni Gmelin, 1789) is based on a multiple signalling system that involves visual, olfactory, tactile, and acoustic signals. In this study, we analysed relationships between male morphology, hematological profile, courtship intensity, vocalizations, and mounting success in Hermann's tortoises breeding in semi-natural enclosures to investigate the effects of male condition on signals exhibited during courtship and on their mounting success. Results showed that mounting success of Hermann's tortoise males was positively affected by the number of sexual interactions/h, number of bites given to the female during interactions, and by call rate and frequency-modulation range. Call rate, frequency-modulation range, and number of sexual interaction/h increased with hematocrit value, while number of bites given to females decreased with leukocyte concentration. In conclusion, courtship signals exhibited by Hermann's tortoise males, including vocalizations, reliably reveal different components of male condition, and females may use these multiple traits to choose high-quality partners. This is the first study documenting the condition-dependent nature of tortoise courting signals and their effect on male mounting success.
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Abubaker, Aisha Alsheikh, Dina Vara, Caterina Visconte, Ian Eggleston, Mauro Torti, Ilaria Canobbio i Giordano Pula. "Amyloid Peptideβ1-42 Induces IntegrinαIIbβ3 Activation, Platelet Adhesion, and Thrombus Formation in a NADPH Oxidase-Dependent Manner". Oxidative Medicine and Cellular Longevity 2019 (14.03.2019): 1–12. http://dx.doi.org/10.1155/2019/1050476.
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The progression of Alzheimer’s dementia is associated with neurovasculature impairment, which includes inflammation, microthromboses, and reduced cerebral blood flow. Here, we investigate the effects ofβamyloid peptides on the function of platelets, the cells driving haemostasis. Amyloid peptideβ1-42 (Aβ1-42), Aβ1-40, and Aβ25-35 were tested in static adhesion experiments, and it was found that platelets preferentially adhere to Aβ1-42 compared to other Aβpeptides. In addition, significant platelet spreading was observed over Aβ1-42, while Aβ1-40, Aβ25-35, and the scAβ1-42 control did not seem to induce any platelet spreading, which suggested that only Aβ1-42 activates platelet signalling in our experimental conditions. Aβ1-42 also induced significant platelet adhesion and thrombus formation in whole blood under venous flow condition, while other Aβpeptides did not. The molecular mechanism of Aβ1-42 was investigated by flow cytometry, which revealed that this peptide induces a significant activation of integrinαIIbβ3, but does not induce platelet degranulation (as measured by P-selectin membrane translocation). Finally, Aβ1-42 treatment of human platelets led to detectable levels of protein kinase C (PKC) activation and tyrosine phosphorylation, which are hallmarks of platelet signalling. Interestingly, the NADPH oxidase (NOX) inhibitor VAS2870 completely abolished Aβ1-42-dependent platelet adhesion in static conditions, thrombus formation in physiological flow conditions, integrinαIIbβ3 activation, and tyrosine- and PKC-dependent platelet signalling. In summary, this study highlights the importance of NOXs in the activation of platelets in response to amyloid peptideβ1-42. The molecular mechanisms described in this manuscript may play an important role in the neurovascular impairment observed in Alzheimer’s patients.
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Foresta, C., M. Rossato, P. Bordon i F. Di Virgilio. "Extracellular ATP activates different signalling pathways in rat Sertoli cells". Biochemical Journal 311, nr 1 (1.10.1995): 269–74. http://dx.doi.org/10.1042/bj3110269.
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1. The present study describes effects of extracellular ATP (ATPe) on plasma membrane potential and cytoplasmic Ca2+ concentrations ([Ca2+]i) in rat Sertoli cells. Sertoli cells in suspension were stimulated with ATPe and other nucleotides and ionic changes were monitored utilizing the fluorescent dyes bis-oxonol and fura-2/AM. ATPe induced a prompt plasma membrane depolarization which was dependent on Na+ influx from the extracellular medium, since it was abolished by omission of extracellular Na+. Depolarization was independent of [Ca2+]i rise as it also occurred in the absence of extracellular Ca2+ and after intracellular Ca2+ stores were discharged with thapsigargin. ATPe also stimulated a rapid and biphasic increase in [Ca2+]i: a prompt spike was followed by a prolonged sustained plateau. The initial spike was dependent on Ca2+ release from intracellular stores since it was also present when cells were incubated in EGTA-supplemented Ca(2+)-free medium and was abolished by pretreatment with ionomycin and thapsigargin, agents that discharge intracellular Ca2+ stores. The sustained phase was dependent on Ca2+ influx from the extracellular medium as it was abolished when cells were incubated in EGTA-supplemented Ca(2+)-free medium. Ca2+ influx was due to activation of voltage-operated calcium channels (VOCCs) since it was abolished by the VOCC inhibitors verapamil and nifedipine or incubation in sucrose medium, an experimental condition which precludes plasma membrane depolarization by ATPe. 2. ATPe-induced rises in intracellular Ca2+ concentration and plasma membrane depolarization were reduced by pretreatment with pertussis toxin, suggesting that ATPe-activated transduction mechanisms are in part under the control of pertussis toxin-sensitive G-proteins. These data show that Sertoli cells possess P2-purinergic receptor subtypes coupled to influx of Na+ and release of Ca2+ from intracellular stores and provide evidence for an activation of different pathways by extracellular ATPe. Activation of these receptors induces Na+ influx that causes a rapid plasma membrane depolarization. Furthermore, ATPe also triggers Ca2+ release from intracellular stores and Ca2+ influx from extracellular space via dihydropyridine-sensitive VOCCs.
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Du Preez, Stanley, Natalie Eaton-Fitch, Peter K. Smith i Sonya Marshall-Gradisnik. "Altered TRPM7-Dependent Calcium Influx in Natural Killer Cells of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients". Biomolecules 13, nr 7 (26.06.2023): 1039. http://dx.doi.org/10.3390/biom13071039.
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Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disabling multisystemic condition. The pathomechanism of ME/CFS remains unestablished; however, impaired natural killer (NK) cell cytotoxicity is a consistent feature of this condition. Calcium (Ca2+) is crucial for NK cell effector functions. Growing research recognises Ca2+ signalling dysregulation in ME/CFS patients and implicates transient receptor potential ion channel dysfunction. TRPM7 (melastatin) was recently considered in the pathoaetiology of ME/CFS as it participates in several Ca2+-dependent processes that are central to NK cell cytotoxicity which may be compromised in ME/CFS. TRPM7-dependent Ca2+ influx was assessed in NK cells isolated from n = 9 ME/CFS patients and n = 9 age- and sex-matched healthy controls (HCs) using live cell fluorescent imaging techniques. Slope (p < 0.05) was significantly reduced in ME/CFS patients compared with HCs following TRPM7 activation. Half-time of maximal response (p < 0.05) and amplitude (p < 0.001) were significantly reduced in the HCs compared with the ME/CFS patients following TRPM7 desensitisation. Findings from this investigation suggest that TRPM7-dependent Ca2+ influx is reduced with agonism and increased with antagonism in ME/CFS patients relative to the age- and sex-matched HCs. The outcomes reported here potentially reflect TRPM3 dysfunction identified in this condition suggesting that ME/CFS is a TRP ion channelopathy.
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David, Morgan, Yannick Auclair, Sasha R. X. Dall i Frank Cézilly. "Pairing context determines condition-dependence of song rate in a monogamous passerine bird". Proceedings of the Royal Society B: Biological Sciences 280, nr 1753 (22.02.2013): 20122177. http://dx.doi.org/10.1098/rspb.2012.2177.
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Condition-dependence of male ornaments is thought to provide honest signals on which females can base their sexual choice for genetic quality. Recent studies show that condition-dependence patterns can vary within populations. Although long-term association is thought to promote honest signalling, no study has explored the influence of pairing context on the condition-dependence of male ornaments. In this study, we assessed the influence of natural variation in body condition on song rate in zebra finches ( Taeniopygia guttata ) in three different situations: during short and long encounters with an unfamiliar female, and within heterosexual mated pairs. We found consistent individual differences in male directed and undirected song rate. Moreover, body condition had a positive effect on song rate in paired males. However, male song rate was not influenced by body condition during short or long encounters with unfamiliar females. Song rate appears to be an unreliable signal of condition to prospective females as even poor-condition birds can cheat and sing at a high rate. By contrast, paired females can reliably use song rate to assess their mate's body condition, and possibly the genetic quality. We propose that species' characteristics, such as mating system, should be systematically taken into account to generate relevant hypotheses about the evolution of condition-dependent male ornaments.
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Mougeot, Francois, Jesuús Martínez-Padilla, Lucy M. I. Webster, Jonathan D. Blount, Lorenzo Pérez-Rodríguez i Stuart B. Piertney. "Honest sexual signalling mediated by parasite and testosterone effects on oxidative balance". Proceedings of the Royal Society B: Biological Sciences 276, nr 1659 (2.12.2008): 1093–100. http://dx.doi.org/10.1098/rspb.2008.1570.
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Extravagant ornaments evolved to advertise their bearers' quality, the honesty of the signal being ensured by the cost paid to produce or maintain it. The oxidation handicap hypothesis (OHH) proposes that a main cost of testosterone-dependent ornamentation is oxidative stress, a condition whereby the production of reactive oxygen and nitrogen species (ROS/RNS) overwhelms the capacity of antioxidant defences. ROS/RNS are unstable, very reactive by-products of normal metabolic processes that can cause extensive damage to key biomolecules (cellular proteins, lipids and DNA). Oxidative stress has been implicated in the aetiology of many diseases and could link ornamentation and genetic variation in fitness-related traits. We tested the OHH in a free-living bird, the red grouse. We show that elevated testosterone enhanced ornamentation and increased circulating antioxidant levels, but caused oxidative damage. Males with smaller ornaments suffered more oxidative damage than those with larger ornaments when forced to increase testosterone levels, consistent with a handicap mechanism. Parasites depleted antioxidant defences, caused oxidative damage and reduced ornament expression. Oxidative damage extent and the ability of males to increase antioxidant defences also explained the impacts of testosterone and parasites on ornamentation within treatment groups. Because oxidative stress is intimately linked to immune function, parasite resistance and fitness, it provides a reliable currency in the trade-off between individual health and ornamentation. The costs induced by oxidative stress can apply to a wide range of signals, which are testosterone-dependent or coloured by pigments with antioxidant properties.
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Burmeister, Sabrina S., Verónica G. Rodriguez Moncalvo i Karin S. Pfennig. "Differential encoding of signals and preferences by noradrenaline in the anuran brain". Journal of Experimental Biology 223, nr 18 (9.07.2020): jeb214148. http://dx.doi.org/10.1242/jeb.214148.
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ABSTRACTSocial preferences enable animals to selectively interact with some individuals over others. One influential idea for the evolution of social preferences is that preferred signals evolve because they elicit greater neural responses from sensory systems. However, in juvenile plains spadefoot toad (Spea bombifrons), a species with condition-dependent mating preferences, responses of the preoptic area, but not of the auditory midbrain, mirror adult social preferences. To examine whether this separation of signal representation from signal valuation generalizes to other anurans, we compared the relative contributions of noradrenergic signalling in the preoptic area and auditory midbrain of S. bombifrons and its close relative Spea multiplicata. We manipulated body condition in juvenile toads by controlling diet and used high pressure liquid chromatography to compare call-induced levels of noradrenaline and its metabolite MHPG in the auditory midbrain and preoptic area of the two species. We found that calls from the two species induced different levels of noradrenaline and MHPG in the auditory system, with higher levels measured in both species for the more energetic S. bombifrons call. In contrast, noradrenaline levels in the preoptic area mirrored patterns of social preferences in both S. bombifrons and S. multiplicata. That is, noradrenaline levels were higher in response to the preferred calls within each species and were modified by diet in S. bombifrons (with condition-dependent preferences) but not S. multiplicata (with condition-independent preferences). Our results are consistent with a potentially important role for preoptic noradrenaline in the development of social preferences and indicate that it could be a target of selection in the evolution of condition-dependent social preferences.
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Özdemi̇r Sanci, Tuba, Hilal Özdağ, Yasin Köksal, Seda Tasır Yılmaz, Husniye Nese Yarali, Namik Yasar Özbek i Habibe Meltem Özgüner. "Transcriptomic Profile of Bone Marrow-Derived Mesenchymal Stromal Cells of Pediatric Pre-B Acute Lymphoblastic Leukemia Patients and Healthy Donors after Interaction with Leukemic Cells". Blood 134, Supplement_1 (13.11.2019): 3957. http://dx.doi.org/10.1182/blood-2019-128282.
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Background: Acute lymphoblastic leukemia (ALL) is a hematological malignancy characterized by the abnormal expansion of clonal lymphoblasts in the bone marrow (BM). The behavior of malignant lymphoblasts is not only dependent on their genomic abnormalities but also, on their complex and reciprocal relationships with their local niche. BM microenvironment is a dynamic network of growth factors, cytokines, and stromal cells, providing a permissive environment for leukemogenesis and progression. Despite some evidence about the implication of the bidirectional interaction between mesenchymal stromal cells (MSCs) and leukemic cell on growth and survival, it is still largely unknown. Although an increasing number of studies are reporting on the expression of specific genes in leukemic cells-interacting MSCs, gene expression profiling in cocultured MSCs (with respect to mono culture conditions) has not been done on a transcriptome-wide basis. Taking all this into consideration, we have established cocultures between BM-derived MSCs and the leukemic mononuclear cells and performed gene expression profile (GEP) studies on the MSC population to determine those deregulated genes due to the coculture condition with respect to MSCs in mono culture. Methods: Primary MSCs from BM samples of healthy donors (n=4) and pediatric pre-B ALL patients (n=4) were isolated and expanded and mononuclear cells were, also, isolated from patients peripheral blood. At passage 2, healthy/patient (h/p) MSCs were cocultured with the leukemic cells for 72 hours and subsequently subjected to GEP analyses. RNA isolated from h/pMSCs and biotinylated amplified RNA was synthesized. For the hybridization HG-U133 Plus, 2.0 GeneChip oligonucleotide arrays (Affymetrix) was used. Raw microarray data were processed into expression values through the Affy package in R. RMA (robust multi-array average) algorithm was used for preprocessing. The linear regression model package LIMMA (Linear Models for Microarray Data) was used to identify significant differential expression of genes (DEGs) compared to h/pMSCs after coculture with MSCs from the same origin in mono culture. Minimum 1.5 fold change and p-value < 0.001 were defined as the threshold. Functional enrichment, gene network and pathway analysis, were performed on selected sets of genes after differential expression analyses using two bioinformatics tools: DAVID Bioinformatics Resources 6.8 and WebGestalt 2019. Results: We identified 293 DEGs when analyzing pMSC samples vs. hMSC in coculture condition and 853 DEGs of pMSC vs. hMSC analyze in mono culture condition and only 15 DEGs common in both group. According to the result of functional enrichment analysis of pMSC vs. hMSC in coculture condition, 29 gene ontology (GO) term biological process including (top five) apoptotic process, axon guidance, regulation of JNK cascade, cell-cell adhesion and protein phosphorylation and 4 KEGG pathways of DEGs including axon guidance, FoxO signalling pathway, Wnt signalling pathway and signalling pathways regulating pluripotency of stem cells were determined. Comparing pMSC vs. hMSC in mono culture condition, 292 GO term biological process including extracellular matrix organization, skeletal system development, angiogenesis and signal transduction and 43 KEGG pathways of DEGs including pathways in cancer, TGFß signalling pathway, ECM-receptor interaction, p53 signalling pathway and PI3-Akt signalling pathway were determined.Five genes with upregulated expression after coculture (COL18A1, EFNA5, MAP3K8, CASP1, IGF1R) and after mono culture (MMP1, CXCL1, IL1B, PCDH10, CXCL6) were identified. Conclusions: Deregulated genes especially after coculture condition in axon guidance and ephrin receptor-mediated signalling pathway of which the importance is not yet understood in cancer microenvironment including EPHB1, ephrinA5, ephrinB3, p21 activated kinase 2 (PAK2), and ROBO3 showed highly differential expression pattern between pMSCs and hMSCs. This is the first report indicating the importance of axon guidance genes as a result of interaction between MSCs and leukemic cells. The elucidation of deregulated mechanisms and pathways provides new molecular insights to the contribution of these cells to ALL pathophysiology and understanding cross talk between these cells may lead to found new therapeutic targets. Disclosures No relevant conflicts of interest to declare.
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Bröer, Stefan, i Angelika Bröer. "Amino acid homeostasis and signalling in mammalian cells and organisms". Biochemical Journal 474, nr 12 (25.05.2017): 1935–63. http://dx.doi.org/10.1042/bcj20160822.
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Cells have a constant turnover of proteins that recycle most amino acids over time. Net loss is mainly due to amino acid oxidation. Homeostasis is achieved through exchange of essential amino acids with non-essential amino acids and the transfer of amino groups from oxidised amino acids to amino acid biosynthesis. This homeostatic condition is maintained through an active mTORC1 complex. Under amino acid depletion, mTORC1 is inactivated. This increases the breakdown of cellular proteins through autophagy and reduces protein biosynthesis. The general control non-derepressable 2/ATF4 pathway may be activated in addition, resulting in transcription of genes involved in amino acid transport and biosynthesis of non-essential amino acids. Metabolism is autoregulated to minimise oxidation of amino acids. Systemic amino acid levels are also tightly regulated. Food intake briefly increases plasma amino acid levels, which stimulates insulin release and mTOR-dependent protein synthesis in muscle. Excess amino acids are oxidised, resulting in increased urea production. Short-term fasting does not result in depletion of plasma amino acids due to reduced protein synthesis and the onset of autophagy. Owing to the fact that half of all amino acids are essential, reduction in protein synthesis and amino acid oxidation are the only two measures to reduce amino acid demand. Long-term malnutrition causes depletion of plasma amino acids. The CNS appears to generate a protein-specific response upon amino acid depletion, resulting in avoidance of an inadequate diet. High protein levels, in contrast, contribute together with other nutrients to a reduction in food intake.
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Cachat, Julien, Christine Deffert, Stephanie Hugues i Karl-Heinz Krause. "Phagocyte NADPH oxidase and specific immunity". Clinical Science 128, nr 10 (20.02.2015): 635–48. http://dx.doi.org/10.1042/cs20140635.
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The phagocyte NADPH oxidase NOX2 produces reactive oxygen species (ROS) and is a well-known player in host defence. However, there is also increasing evidence for a regulatory role of NOX2 in adaptive immunity. Deficiency in phagocyte NADPH oxidase causes chronic granulomatous disease (CGD) in humans, a condition that can also be studied in CGD mice. Clinical observations in CGD patients suggest a higher susceptibility to autoimmune diseases, in particular lupus, idiopathic thrombocytopenic purpura and rheumatoid arthritis. In mice, a strong correlation exists between a polymorphism in a NOX2 subunit and the development of autoimmune arthritis. NOX2 deficiency in mice also favours lupus development. Both CGD patients and CGD mice exhibit increased levels of immunoglobulins, including autoantibodies. Despite these phenotypes suggesting a role for NOX2 in specific immunity, mechanistic explanations for the typical increase of CGD in autoimmune disease and antibody levels are still preliminary. NOX2-dependent ROS generation is well documented for dendritic cells and B-lymphocytes. It is unclear whether T-lymphocytes produce ROS themselves or whether they are exposed to ROS derived from dendritic cells during the process of antigen presentation. ROS are signalling molecules in virtually any cell type, including T- and B-lymphocytes. However, knowledge about the impact of ROS-dependent signalling on T- and B-lymphocyte phenotype and response is still limited. ROS might contribute to Th1/Th2/Th17 cell fate decisions during T-lymphocyte activation and might enhance immunoglobulin production by B-lymphocytes. In dendritic cells, NOX2-derived ROS might be important for antigen processing and cell activation.
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Dri, Maria, Francesca Gioia Klinger i Massimo De Felici. "The ovarian reserve as target of insulin/IGF and ROS in metabolic disorder-dependent ovarian dysfunctions". Reproduction and Fertility 2, nr 3 (16.09.2021): R103—R112. http://dx.doi.org/10.1530/raf-21-0038.
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It is known for a long time that metabolic disorders can cause ovarian dysfunctions and affect a woman’s fertility either by direct targeting follicular cells and/or the oocytes or by indirect interference with the pituitary-hypothalamic axis, resulting in dysfunctional oogenesis. Such disorders may also influence the efficiency of the embryo implantation and the quality of the embryo with permanent effects on the fertility and health of the offspring. Thanks to the expanding knowledge on the molecular mechanisms governing oogenesis and folliculogenesis in mammals, we are beginning to understand how such disorders can negatively affect this process and consequently fertility in women. In the present review, we point out and discuss how the disturbance of insulin/IGF-dependent signalling and increased reactive oxygen species (ROS) level in the ovary typically associated to metabolic disorders such as type II diabetes and obesity can dysregulate the dynamics of the ovarian reserve and/or impair the survival and competence of the oocytes. Lay summary In women, a progressive decline and depletion of the primary ovary reserve, which represents the reserve of immature eggs, are a challenging condition in the field of reproductive medicine. This decline, occurring physiological with age, is the main determinant of the age at the onset of menopause. Concomitant with the reduction in their number, the quality of the eggs also decreases with age. Metabolic disorders such as diabetes and obesity can cause ovarian dysfunctions and affect a woman’s fertility mainly by direct targeting the egg stockpile or by indirect interference with the production of reproductive hormones. Here, we report up-to-date data and discuss results about how disturbance of insulin-dependent signalling and increased oxidative stress in the ovary, usually associated to metabolic disorders, can dysregulate the dynamics of the primary ovary reserve and/or impair the survival and quality of the eggs.
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Basseri, Sana, i Richard C. Austin. "Endoplasmic Reticulum Stress and Lipid Metabolism: Mechanisms and Therapeutic Potential". Biochemistry Research International 2012 (2012): 1–13. http://dx.doi.org/10.1155/2012/841362.
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The endoplasmic reticulum (ER) plays a crucial role in protein folding, assembly, and secretion. Disruption of ER homeostasis may lead to accumulation of misfolded or unfolded proteins in the ER lumen, a condition referred to as ER stress. In response to ER stress, a signal transduction pathway known as the unfolded protein response (UPR) is activated. UPR activation allows the cell to cope with an increased protein-folding demand on the ER. Recent studies have shown that ER stress/UPR activation plays a critical role in lipid metabolism and homeostasis. ER-stress-dependent dysregulation of lipid metabolism may lead to dyslipidemia, insulin resistance, cardiovascular disease, type 2 diabetes, and obesity. In this paper, we examine recent findings illustrating the important role ER stress/UPR signalling pathways play in regulation of lipid metabolism, and how they may lead to dysregulation of lipid homeostasis.
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Neri, Paola, Pierfrancesco Tassone, Masood Shammas, Hiroshi Yasui, Ernestina Schipani, Ramesh B. Batchu, Simona Blotta i in. "Biological Pathways and In Vivo Anti-Tumor Activity Induced by Atiprimod in Multiple Myeloma (MM)." Blood 108, nr 11 (16.11.2006): 3455. http://dx.doi.org/10.1182/blood.v108.11.3455.3455.
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Abstract Atiprimod (N-N-diethl-8, 8-dipropyl-2-azaspiro [4.5] decane-2-propanamine) is a novel orally bio-available agent with anti-inflammatory properties. Although its in vitro anti-MM activity have been previously reported, here we have investigated molecular changes induced by Atiprimod as well as its in vivo activity in murine models of MM. Atiprimod inhibits in vitro growth and survival of IL-6 dependent as well as independent MM cell-lines in a time- and dose-dependent manner. Evaluation of changes in gene expression profile following treatment with Atiprimod identified down-regulation of genes involved in adhesion, cell-signalling, cell-cycle and BMP pathways and up-regulation of genes implicated in apoptosis and bone metabolism. The signalling pathway analysis identified the integrin, TGF-beta and FGF signaling as well as Wnt/b-catenin, IGF1 and cell cycle regulation networks as being most modulated by Atiprimod treatment. Next, we evaluated its in vivo activity in three different murine models of MM. A xenograft model bearing subcutaneous MM cells confirmed in vivo the anti-MM activity of Atiprimod and established its dose-response activity; a model based on engraftment of human fetal bone chip implanted in SCID mice (SCID-hu) with INA-6 cells, confirmed its ability to overcome the protective effects of the bone marrow milieu on MM cell growth, survival and drug resistance; and a SCID-hu model engrafted with primary patient MM cells confirmed its activity in the context of primary human disease recapitulating the clinical condition. Finally, we observed reduced number of osteoclasts, following Atiprimod treatment, compared to control bone samples confirming its beneficial effects on bone remodelling. Taken together, these data demonstrate the in vitro and in vivo anti-tumor activity of Atiprimod and delineate potential molecular targets triggered by this agent, providing a preclinical rational for its clinical evaluation in MM.
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Habibpourmehraban, Fatemeh, Yunqi Wu, Farhad Masoomi-Aladizgeh, Ardeshir Amirkhani, Brian J. Atwell i Paul A. Haynes. "Pre-Treatment of Rice Plants with ABA Makes Them More Tolerant to Multiple Abiotic Stress". International Journal of Molecular Sciences 24, nr 11 (1.06.2023): 9628. http://dx.doi.org/10.3390/ijms24119628.
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Multiple abiotic stress is known as a type of environmental unfavourable condition maximizing the yield and growth gap of crops compared with the optimal condition in both natural and cultivated environments. Rice is the world’s most important staple food, and its production is limited the most by environmental unfavourable conditions. In this study, we investigated the pre-treatment of abscisic acid (ABA) on the tolerance of the IAC1131 rice genotype to multiple abiotic stress after a 4-day exposure to combined drought, salt and extreme temperature treatments. A total of 3285 proteins were identified and quantified across the four treatment groups, consisting of control and stressed plants with and without pre-treatment with ABA, with 1633 of those proteins found to be differentially abundant between groups. Compared with the control condition, pre-treatment with the ABA hormone significantly mitigated the leaf damage against combined abiotic stress at the proteome level. Furthermore, the application of exogenous ABA did not affect the proteome profile of the control plants remarkably, while the results were different in stress-exposed plants by a greater number of proteins changed in abundance, especially those which were increased. Taken together, these results suggest that exogenous ABA has a potential priming effect for enhancing the rice seedlings’ tolerance against combined abiotic stress, mainly by affecting stress-responsive mechanisms dependent on ABA signalling pathways in plants.
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Caspers, Barbara A., E. Tobias Krause, Isabelle Hermanski, Christopher Wiesbrock, Friedrich-Wilhelm Kastrup i Sebastian Steinfartz. "Developmental costs of yellow colouration in fire salamanders and experiments to test the efficiency of yellow as a warning colouration". Amphibia-Reptilia 41, nr 3 (30.06.2020): 373–85. http://dx.doi.org/10.1163/15685381-bja10006.
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Abstract Warning colouration reduces predation risk by signalling or mimicking the unpleasantness of prey and therefore increases survival. We tested in two experiments the evolutionary costs and benefits of the yellow colour pattern in fire salamanders (Salamandra salamandra), which display a yellow/black colour pattern usually associated with toxic alkaloids. Our first experiment aimed to test whether the development of colouration is condition dependent and thus related to developmental costs, i.e. influenced by resource availability during the developmental process. Therefore, we reared fire salamander larvae under different nutritional conditions and compared the relative amount of yellow they developed after metamorphosis. Fire salamander larvae reared under limited food conditions had a lower proportion of yellow following metamorphosis than control larvae reared under superior food conditions. In a second experiment we tested whether the proportion of yellow has an impact on the risk of being attacked using artificial models. We tested, in salamander-free and salamander-occupied natural habitats, whether artificial clay models with different proportions of yellow and black receive different attack rates from potential predators (birds, mammals, insects). In clay models the proportion of yellow and the site had a significant effect on predation risk. Models with larger amounts of yellow had fewer bite marks from predators such as carabid beetles and birds, but only in sympatry with salamanders. In conclusion, the early expression of conspicuous colouration seems to be condition dependent and therefore potentially costly. Furthermore, the yellow colouration of fire salamanders act as a signal that potentially reduces their risk of being attacked by predators. Thus, the yellow colouration of fire salamanders seems to represent an adaptive trait that reduces the risk of predation, which can be expressed in higher quantity by individuals of a certain condition.
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Hou, Shiji, Thorsten Thiergart, Nathan Vannier, Fantin Mesny, Jörg Ziegler, Brigitte Pickel i Stéphane Hacquard. "A microbiota–root–shoot circuit favours Arabidopsis growth over defence under suboptimal light". Nature Plants 7, nr 8 (5.07.2021): 1078–92. http://dx.doi.org/10.1038/s41477-021-00956-4.
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AbstractBidirectional root–shoot signalling is probably key in orchestrating stress responses and ensuring plant survival. Here, we show that Arabidopsis thaliana responses to microbial root commensals and light are interconnected along a microbiota–root–shoot axis. Microbiota and light manipulation experiments in a gnotobiotic plant system reveal that low photosynthetically active radiation perceived by leaves induces long-distance modulation of root bacterial communities but not fungal or oomycete communities. Reciprocally, microbial commensals alleviate plant growth deficiency under low photosynthetically active radiation. This growth rescue was associated with reduced microbiota-induced aboveground defence responses and altered resistance to foliar pathogens compared with the control light condition. Inspection of a set of A. thaliana mutants reveals that this microbiota- and light-dependent growth–defence trade-off is directly explained by belowground bacterial community composition and requires the host transcriptional regulator MYC2. Our work indicates that aboveground stress responses in plants can be modulated by signals from microbial root commensals.
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Chen, Yi-Ju, Ching-Fang Chang, Jayaraman Angayarkanni i Wan-Teng Lin. "Alcalase Potato Protein Hydrolysate-PPH902 Enhances Myogenic Differentiation and Enhances Skeletal Muscle Protein Synthesis under High Glucose Condition in C2C12 Cells". Molecules 26, nr 21 (30.10.2021): 6577. http://dx.doi.org/10.3390/molecules26216577.
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Sarcopenia is an aging associated disorder involving skeletal muscle atrophy and a reduction in muscle strength, and there are no pharmaceutical interventions available thus far. Moreover, conditions such as hyperglycaemia are known to further intensify muscle degradation. Therefore, novel strategies to attenuate skeletal muscle loss are essential to enhance muscle function and thereby improve the quality of life in diabetic individuals. In this study, we have investigated the efficiency of a potato peptide hydrolysate PPH902 for its cytoprotective effects in skeletal muscle cells. PPH902 treatment in C2C12 cells showed the dose-dependent activation of the Akt/mTOR signalling pathway that is involved in skeletal myogenesis. According to Western blotting analysis, PPH902 induced the phosphorylation of Akt, mTOR proteins and induced the myogenic differentiation of C2C12 myoblasts in a differentiation medium. The phosphorylation myogenic transcription factor Foxo3A was also found to be increased in the cells treated with PPH902. In addition, treatment with PPH902 ameliorated the high glucose induced reduction in cell viability in a dose-dependent manner. Moreover, the number of myotubes in a differentiation medium reduced upon high glucose challenge, but treatment with PPH902 increased the number of differentiated myotubes. Further, the phosphorylations of AMPK and mitochondrial-related transcription factors such as PGC-1α were suppressed upon high glucose challenge but PPH902 treatment restored the protein levels. We demonstrate, for the first time, that a specific potato peptide has a therapeutic effect against sarcopenia. In addition, PPH902 improved the myogenic differentiation and their mitochondrial biogenesis and further improved myogenic protein and inhibited muscle protein degradation in C2C12 cells challenged under a high glucose condition.
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RIBAUX, Pascale G., i Patrick B. IYNEDJIAN. "Analysis of the role of protein kinase B (cAKT) in insulin-dependent induction of glucokinase and sterol regulatory element-binding protein 1 (SREBP1) mRNAs in hepatocytes". Biochemical Journal 376, nr 3 (15.12.2003): 697–705. http://dx.doi.org/10.1042/bj20031287.
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Previous work showed that acute stimulation of a conditionally active protein kinase B (PKB or cAKT) was sufficient to elicit insulin-like induction of GCK (glucokinase) and SREBP1 (sterol regulatory element-binding protein 1) in hepatocytes [Iynedjian, Roth, Fleischmann and Gjinovci (2000) Biochem. J. 351, 621–627; Fleischmann and Iynedjian (2000) Biochem. J. 349, 13–17]. The objective of the present study was to determine whether activation of PKB during insulin stimulation of hepatocytes was a necessary condition for the induction of the two genes. Activation of PKB by insulin was inhibited by pretreatment of the hepatocytes with C2 ceramide. This resulted in the inhibition of insulin-dependent increases in GCK and SREBP1 mRNAs. A triple mutant of PKB failed to interfere with insulin activation of PKB in hepatocytes even at high overexpression levels achieved after adenovirus transduction. A PKB–CaaX fusion protein, which can act as a dominant-negative inhibitor of PKB activation in other cells, was shown to be constitutively activated in hepatocytes and to trigger insulin-like induction of GCK and SREBP1. In addition, constitutive PKB–CaaX activity caused refractoriness of the hepatocytes to insulin signalling at an upstream step resulting in the inhibition of both extracellular-signal-regulated kinase 1/2 and endogenous PKB activation. The stimulation of gene expression by constitutively active PKB–CaaX and inhibition of the insulin effect by ceramide are compatible with a role for PKB in the insulin-dependent induction of GCK and SREBP1.
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Yang, Yajun, Yanjie Su, Dongtao Wang, Yahui Chen, Tie Wu, Gang Li, Xuegang Sun i Liao Cui. "Tanshinol Attenuates the Deleterious Effects of Oxidative Stress on Osteoblastic Differentiation via Wnt/FoxO3a Signaling". Oxidative Medicine and Cellular Longevity 2013 (2013): 1–18. http://dx.doi.org/10.1155/2013/351895.
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There is now increasing evidence which suggests a pivotal role for oxidative stress in the development and progression of osteoporosis. We confirm herein the protective effects of natural antioxidant Tanshinol against oxidative stress in osteoblastic differentiation and the underlying mechanism. Our results show that hydrogen peroxide (H2O2) leads to accumulation of reactive oxygen species (ROS), decrease in cell viability, cell cycle arrest and apoptosis in a caspase-3-dependent manner, and inhibition of osteoblastic differentiation. Tanshinol reverses these deleterious consequence triggered by oxidative stress. Moreover, under the condition of oxidative stress, Tanshinol suppresses the activation of FoxO3a transcription factor and expressions of its target genesGadd45aandcatalase (CAT)and simultaneously counteracts the inhibition of Wnt signalling and expressions of target genesAxin2,alkaline phosphatase (ALP), andOsteoprotegerin (OPG). The findings are further consolidated using FoxO3a siRNA interference and overexpression of Tcf4. The results illustrate that Tanshinol attenuates oxidative stress via down-regulation of FoxO3a signaling, and rescues the decrease of osteoblastic differentiation through upregulation of Wnt signal under oxidative stress. The present findings suggest that the beneficial effects of Tanshinol may be adopted as a novel therapeutic approach in recently recognized conditions of niche targeting osteoporosis.
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Whiting, Martin J., Jonathan K. Webb i J. Scott Keogh. "Flat lizard female mimics use sexual deception in visual but not chemical signals". Proceedings of the Royal Society B: Biological Sciences 276, nr 1662 (25.02.2009): 1585–91. http://dx.doi.org/10.1098/rspb.2008.1822.
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Understanding what constrains signalling and maintains signal honesty is a central theme in animal communication. Clear cases of dishonest signalling, and the conditions under which they are used, represent an important avenue for improved understanding of animal communication systems. Female mimicry, when certain males take on the appearance of females, is most commonly a male alternative reproductive tactic that is condition-dependent. A number of adaptive explanations for female mimicry have been proposed including avoiding the costs of aggression, gaining an advantage in combat, sneaking copulations with females on the territories of other males, gaining physiological benefits and minimizing the risk of predation. Previous studies of female mimicry have focused on a single mode of communication, although most animals communicate using multiple signals. Male Augrabies flat lizards adopt alternative reproductive tactics in which some males (she-males) mimic the visual appearance of females. We experimentally tested in a wild population whether she-males are able to mimic females using both visual and chemical signals. We tested chemical recognition in the field by removing scent and relabelling females and she-males with either male or female scent. At a distance, typical males (he-males) could not distinguish she-males from females using visual signals, but during close encounters, he-males correctly determined the gender of she-males using chemical signals. She-males are therefore able to deceive he-males using visual but not chemical signals. To effectively deceive he-males, she-males avoid close contact with he-males during which chemical cues would reveal their deceit. This strategy is probably adaptive, because he-males are aggressive and territorial; by mimicking females, she-males are able to move about freely and gain access to females on the territories of resident males.
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Modos, D., L. Gul, J. Lo, M. Madgwick, D. Cozzetto, G. Lord, T. Korcsmaros i N. Powell. "P011 New insights into the pathogenic potential and signalling network of NKG2D+ CD4+ T-cells in Crohn’s Disease". Journal of Crohn's and Colitis 16, Supplement_1 (1.01.2022): i141. http://dx.doi.org/10.1093/ecco-jcc/jjab232.140.
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Abstract Background A subset of mucosal CD4+ T-cells expressing the NK cell receptor NKG2D (encoded by the KLRK1 gene) are enriched in patients with Crohn’s Disease (CD). In pre-clinical models of colitis, NKG2D expression was confined to a subset of colonic CD4+ T-cells that hyper-expressed interferon gamma. However, the functional role of these cells in mediating intestinal inflammation is unknown. Little is known about the transcriptional regulation of this population or the key signalling networks that they engage. Methods Pre-clinical models of CD, adoptive transfer experiments and in vitro culture systems were used to investigate the phenotype and pathogenicity of NKG2D using Klrk1-/- and WT mice. Signalling networks and interactions between NKG2D, key transcription factors and relevant cytokines were investigated by probing published single-cell RNA seq data (Martin et al. Cell 2019). Pathway members of potential interactions were collected from the literature, and the OmniPath database and we applied a heat propagation model. Results NKG2D-expressing T-cells were potently pathogenic when adoptively transferred to Rag1- mice, mediating more severe disease than Klrk1-/- CD4+ T-cells. Notably, Klrk-/- T-cells were still able to induce colitis, indicating that NKG2D-independent pathogenic pathways also exist. Chromatin immunoprecipitation demonstrated that T-bet bound at the transcriptional start site of the Klrk1 locus in WT Th1 cells, but not Tbx21-/- Th1 T-cells. There were significantly fewer NKG2D expressing CD4+ T-cells from Tbx21-/- mice, and forced expression of T-bet in Tbx21-/-Ifng-/- double knockout CD4+ T-cells induced Klrk1 mRNA expression, consistent with T-bet being a transcriptional activator of the Klrk1 gene. The NKG2D model network reached FOS, NFKB and JUN transcription factors depending on the presence of the NKG2D. The model distinguished two comparable pathway activation - one with active PRKCA in T-cells including CD8+ T-cells and one with less active PRKCA mostly in macrophages. Comparing the inflamed and uninflamed conditions, highly activated T-cells, and a population of Th17+ TRM cells had an active KLRK pathway only in inflamed Crohn disease. Conclusion NKG2D expressing colonic CD4+ T-cells are potent cytokine producing cells and are more colitigenic than their NKG2D-negative counterparts. Network-based heat propagation showed that specific populations of colonic memory T cells are active only in the inflamed condition, meanwhile, the model identified two types of cells that had active KLRK1 pathway: one which was PRKCA dependent activity and one which had non-PRKCA dependent activity. We also identify T-bet as an important transcriptional regulator of NKG2D expression.
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Klag, Thomas, Nicolai Härtel, Thomas Schenk, Adam R. Craig, Andreas Hochhaus i Paul La Rosee. "Downregulation of the Common Cytokine Receptor Subunit Beta c by Omacetaxine in CML: A Potential Molecular Mechanism to Overcome Cytokine-Mediated Resistance against BCR-ABL-Inhibitors." Blood 114, nr 22 (20.11.2009): 3256. http://dx.doi.org/10.1182/blood.v114.22.3256.3256.
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Abstract Abstract 3256 Poster Board III-1 Introduction: Inhibition of BCR-ABL by imatinib is standard treatment for patients with chronic myeloid leukemia (CML). Despite favourable response rates, overcoming primary and secondary resistance against BCR-ABL inhibitors is of upmost clinical importance. A proposed mechanism of CML stem-cell survival is cytokine-dependent activation of anti-apoptotic and promitogenic signalling cascades despite continued treatment with tyrosine kinase inhibitors (TKI). Additionally, resistance inducing point mutations of the BCR-ABL kinase domain besides lowering the drug-target affinity of TKIs also seem to interfere with cytokine signalling by not yet fully understood mechanisms. Omacetaxine mepesuccinate (OM, formerly known as homoharringtonine) is showing promising results in phase II clinical trials even in patients with the highly resistant mutation T315I. Preliminary results suggest deselection of the aggressive T315I-clone by OM. We therefore went back to pre-clinical resistance models to study mechanisms of OM-dependent antileukemic activity. Methods: Two murine cell lines with induced expression of unmutated and T315I-mutant BCR-ABL (32Dp210, Baf3p210), and a human CML cell line with induced imatinib-resistance due to continuous drug exposure (KBM5s, KBM5r-T315I) were used in addition to primary CD34+ enriched stem cell cultures. Results: Dye exclusion proliferation assays confirmed BCR-ABL-dependent sensitization of cell lines to OM in the low nanomolar dose range. Expression of BCR-ABL-mutant T315I does not confer cross-resistance to OM in myeloid cell lines. However, it slightly reduces OM-sensitivity in lymphoid Baf3p210-T315I cells with a 2.5-fold increased IC50-value. OM induced suppression of cell viability is mediated by Caspase-3-dependent apoptosis as detected by flow cytometry. Addition of Interleukin-3 (IL3), shown to revert BCR-ABL-inhibitor dependent cytotoxicity in the murine 32Dp210 and Baf3p210 cell lines, does not affect OM-induced antiproliferative activity. In addition, cytotoxicity of OM against CD34-enriched CML stem cells grown in the presence of a high vs low physiological growth factor mix (GF) is unaffected by the respective GF-condition. Looking at potential mechanisms, we found marked OM-induced downregulation of the beta-subunit of the IL3-receptor (IL3-R) in both, cell lines, and primary stem cell cultures as detected by Western blot, irrespective of the mutational status, at the clinically relevant concentration of 40 nM OM. Due to the significantly reduced IL3-R-expression in BCR-ABL-T315I-expressing cells compared to unmutated BCR-ABL-expressing cells, OM-treatment leads to near complete eradication of the IL3-R in BCR-ABL-T315I positive cells. Combined treatment of Baf3p210 cells with Nilotinib and OM reveals that OM overrides cytokine mediated rescue of TKI treatment. Conclusions: The observed cytokine-independent in-vitro cytotoxicity of OM may be explained by OM-induced suppression of IL3-R-expression. Loss of IL3-R-expression in BCR-ABL-T315I expressing cells could be one mechanism governing the clinically observed deselection of the resistant clone in patients treated with OM. Cytokine receptor directed action of OM in CML needs to be explored as a potential strategy to overcome cytokine dependent resistance development against TKI-treatment, and to further explore OM-activity against disease maintaining stem cells. Disclosures: Craig: ChemGenex: Employment.
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Walsh, N., J. Dale, K. J. McGraw, M. A. Pointer i N. I. Mundy. "Candidate genes for carotenoid coloration in vertebrates and their expression profiles in the carotenoid-containing plumage and bill of a wild bird". Proceedings of the Royal Society B: Biological Sciences 279, nr 1726 (18.05.2011): 58–66. http://dx.doi.org/10.1098/rspb.2011.0765.
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Carotenoid-based coloration has attracted much attention in evolutionary biology owing to its role in honest, condition-dependent signalling. Knowledge of the genetic pathways that regulate carotenoid coloration is crucial for an understanding of any trade-offs involved. We identified genes with potential roles in carotenoid coloration in vertebrates via (i) carotenoid uptake ( SR-BI , CD36 ), (ii) binding and deposition ( StAR1 , MLN64 , StAR4 , StAR5 , APOD , PLIN , GSTA2 ), and (iii) breakdown ( BCO2 , BCMO1) . We examined the expression of these candidate loci in carotenoid-coloured tissues and several control tissues of the red-billed quelea ( Quelea quelea ), a species that exhibits a male breeding plumage colour polymorphism and sexually dimorphic variation in bill colour. All of the candidate genes except StAR1 were expressed in both the plumage and bill of queleas, indicating a potential role in carotenoid coloration in the quelea. However, no differences in the relative expression of any of the genes were found among the quelea carotenoid phenotypes, suggesting that other genes control the polymorphic and sexually dimorphic variation in carotenoid coloration observed in this species. Our identification of a number of potential carotenoid genes in different functional categories provides a critical starting point for future work on carotenoid colour regulation in vertebrate taxa.
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Błyszczuk, Przemysław, Christian Zuppinger, Ana Costa, Daria Nurzynska, Franca Di Meglio, Mara Stellato, Irina Agarkova, Godfrey Smith, Oliver Distler i Gabriela Kania. "Activated Cardiac Fibroblasts Control Contraction of Human Fibrotic Cardiac Microtissues by a β-Adrenoreceptor-Dependent Mechanism". Cells 9, nr 5 (20.05.2020): 1270. http://dx.doi.org/10.3390/cells9051270.
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Cardiac fibrosis represents a serious clinical problem. Development of novel treatment strategies is currently restricted by the lack of the relevant experimental models in a human genetic context. In this study, we fabricated self-aggregating, scaffold-free, 3D cardiac microtissues using human inducible pluripotent stem cell (iPSC)-derived cardiomyocytes and human cardiac fibroblasts. Fibrotic condition was obtained by treatment of cardiac microtissues with profibrotic cytokine transforming growth factor β1 (TGF-β1), preactivation of foetal cardiac fibroblasts with TGF-β1, or by the use of cardiac fibroblasts obtained from heart failure patients. In our model, TGF-β1 effectively induced profibrotic changes in cardiac fibroblasts and in cardiac microtissues. Fibrotic phenotype of cardiac microtissues was inhibited by treatment with TGF-β-receptor type 1 inhibitor SD208 in a dose-dependent manner. We observed that fibrotic cardiac microtissues substantially increased the spontaneous beating rate by shortening the relaxation phase and showed a lower contraction amplitude. Instead, no changes in action potential profile were detected. Furthermore, we demonstrated that contraction of human cardiac microtissues could be modulated by direct electrical stimulation or treatment with the β-adrenergic receptor agonist isoproterenol. However, in the absence of exogenous agonists, the β-adrenoreceptor blocker nadolol decreased beating rate of fibrotic cardiac microtissues by prolonging relaxation time. Thus, our data suggest that in fibrosis, activated cardiac fibroblasts could promote cardiac contraction rate by a direct stimulation of β-adrenoreceptor signalling. In conclusion, a model of fibrotic cardiac microtissues can be used as a high-throughput model for drug testing and to study cellular and molecular mechanisms of cardiac fibrosis.
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Gąssowska-Dobrowolska, Magdalena, Agnieszka Kolasa-Wołosiuk, Magdalena Cieślik, Agnieszka Dominiak, Kristina Friedland i Agata Adamczyk. "Alterations in Tau Protein Level and Phosphorylation State in the Brain of the Autistic-Like Rats Induced by Prenatal Exposure to Valproic Acid". International Journal of Molecular Sciences 22, nr 6 (22.03.2021): 3209. http://dx.doi.org/10.3390/ijms22063209.
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Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficient social interaction and communication besides repetitive, stereotyped behaviours. A characteristic feature of ASD is altered dendritic spine density and morphology associated with synaptic plasticity disturbances. Since microtubules (MTs) regulate dendritic spine morphology and play an important role in spine development and plasticity the aim of the present study was to investigate the alterations in the content of neuronal α/β-tubulin and Tau protein level as well as phosphorylation state in the valproic acid (VPA)-induced rat model of autism. Our results indicated that maternal exposure to VPA induces: (1) decrease the level of α/β-tubulin along with Tau accumulation in the hippocampus and cerebral cortex; (2) excessive Tau phosphorylation and activation of Tau-kinases: CDK5, ERK1/2, and p70S6K in the cerebral cortex; (3) up-regulation of mTOR kinase-dependent signalling in the hippocampus and cerebral cortex of adolescent rat offspring. Moreover, immunohistochemical staining showed histopathological changes in neurons (chromatolysis) in both analysed brain structures of rats prenatally exposed to VPA. The observed changes in Tau protein together with an excessive decrease in α/β-tubulin level may suggest destabilization and thus dysfunction of the MT cytoskeleton network, which in consequence may lead to the disturbance in synaptic plasticity and the development of autistic-like behaviours.
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Aziz, Nazihah Husna Abdul, Yingrou Tan, Joanna Brzostek, Lai Guan Ng i Nicholas R. J. Gascoigne. "Alteration in Three-Dimensional Microenvironment of Themis-deficient Murine Thymus Using Image Cytometry Approach". Journal of Immunology 204, nr 1_Supplement (1.05.2020): 62.10. http://dx.doi.org/10.4049/jimmunol.204.supp.62.10.
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Abstract Themis is a T-cell intrinsic protein involved in selection during thymocyte development in the thymus. Thus, Themis-deficient mice have gravely reduced numbers of T-cells. Despite extensive research on thymocyte signalling, the exact role of Themis remains a mystery. As the thymic 3-dimensional (3D) microenvironment is a critical element in supporting thymocyte development and vice versa, we were interested to investigate the effect of Themis deficiency on thymic components and processes. In this study, we paired 3D imaging with conventional flow cytometry to understand thymic development in normal and Themis-deficient condition. Current conventional 2-dimensional (2D) histology and 3D reconstruction from 2D sections are unsatisfactory for studying thymus morphology. We thus established a novel approach for whole thymus 3D imaging to visualize developing thymocytes and supporting stroma, such as epithelial cells, myeloid cells and vasculature. 3D imaging coupled with quantitative analysis of images using image cytometry allows for objective comparison of the thymic microenvironment between sample groups. Here, we show an altered medullary and vasculature organization in Themis−/− thymus, suggesting a suboptimal 3D niche supporting thymocyte development. Correspondingly, mature single-positive thymocytes which are dependent on the medullary environment are altered phenotypically. In addition, we detected higher levels of apoptosis in Themis−/− cortex and an increase in clonally deleted double-positive thymocytes. Our findings demonstrate how Themis-deficiency affects developing thymocytes and its supporting stromal components.
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Wasson, C., E. Clavane, R. Ross, G. Migneco, C. Antinozzi, J. Brown, L. Di Luigi, C. Mckimmie, F. Del Galdo i P. Meakin. "OP0113 THE BETA SECRETASE BACE1 DRIVES SYSTEMIC SCLEROSIS FIBROBLASTS ACTIVATION THROUGH Β-CATENIN AND NOTCH SIGNALLING". Annals of the Rheumatic Diseases 82, Suppl 1 (30.05.2023): 75.1–75. http://dx.doi.org/10.1136/annrheumdis-2023-eular.2236.
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BackgroundThe beta-amyloid precursor protein cleaving enzyme 1 (BACE1) is well known for its role in the development of Alzheimer’s disease via the generation of β-amyloid. Recent publications, including our own, have demonstrated a role for this enzyme in other chronic inflammatory diseases, including type 2 diabetes and cardiovascular disease. However, to date there has been no studies looking into the role of BACE1 in the autoimmune condition Systemic Sclerosis (SSc).ObjectivesThe aim of this study was to assess the expression profile of BACE1 in SSc patient samples and investigate the effects of BACE1 inhibitors and siRNA on SSc fibroblast activation.MethodsPatient fibroblasts were obtained from full thickness forearm skin biopsies from healthy and early diffuse SSc patients. BACE1 was inhibited with 2 specific small molecule inhibitors and siRNA specific to BACE1. Morphogen signalling was activated with recombinant TGF-β, Wnt-3a or the smoothened agonist SAG. A xenotransplant bleomycin mouse model using patient pDC was used to interrogatein vivoexpression of BACE1 in fibrosis.ResultsHere we show that BACE1 protein levels are elevated in SSc patient skin biopsies. In particular BACE1 was increased in the fibroblasts and endothelial cells of the SSc skin. BACE1 was elevated in isolated dermal fibroblasts grown in culture (2.3 fold increase, N=4). BACE1 protein levels were elevated in the bleomycin skin fibrosis model. Interestingly BACE1 mRNA levels were unaffected in cultured SSc fibroblasts, suggesting a post-translational modification led to the elevated protein levels.Inhibition of BACE1 with small molecule inhibitors (that have been proven safe in phase 1 clinical trials for Alzheimer’s) or siRNA blocked pro-fibrotic gene (alpha SMA, Collagen Type 1 and CTGF) expression in SSc fibroblasts. In addition overexpression of BACE1 in healthy fibroblasts resulted in myofibroblast activation (2-fold increase in alpha SMA protein expression). Interestingly overexpression of a BACE1 mutant construct which disrupts the secretase activity of the protein, was unable to induce fibroblast activation.Disruption of BACE1 (with both the inhibitors and siRNA) blocked morphogen mediated fibroblasts activation. The BACE1 inhibitors and siRNA blocked TGF-β, Wnt-3a and Hedgehog mediated alpha-SMA expression in healthy fibroblasts. Furthermore, we show that BACE1 regulation of dermal fibroblast activation was dependent on the β-catenin and Notch signalling pathways. BACE1 ability to regulate non-canonical Wnt receptors led to elevated β-catenin expression which in turn activated the Notch signalling pathway.ConclusionThis is the first evidence that BACE1 and in particular its secretase activity, plays a role in SSc and fibrosis in general. The ability of BACE1 to regulate SSc fibroblast activation reveals an exciting new therapeutic target in SSc. Several BACE1 inhibitors have been shown to be safe in phase 1 clinical trials for Alzheimer’s disease. Future work includes investigating the role of BACE1 in vascular/endothelial cell dysfunction in SSc.REFERENCES:NIL.Acknowledgements:NIL.Disclosure of InterestsNone Declared.
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LIVINGSTONE, Callum, i Mary COLLISON. "Sex steroids and insulin resistance". Clinical Science 102, nr 2 (3.01.2002): 151–66. http://dx.doi.org/10.1042/cs1020151.
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There is extensive experimental evidence that sex steroids and insulin interact in their actions on tissues. At physiological levels, testosterone and oestradiol are thought to be involved in maintaining normal insulin sensitivity. However, outside this ‘physiological window’ these steroids may promote insulin resistance. Considerable research has been carried out on polycystic ovarian syndrome, a common disorder associated with excessive androgen production and insulin resistance. Hyperinsulinaemia in patients with this condition is believed to stimulate ovarian androgen production, and there is also evidence that androgens act directly on peripheral tissues to promote insulin resistance. There is the potential for a vicious circle to develop with increasing androgen production and insulin resistance. The molecular basis of this insulin resistance has been reported to involve reduced insulin receptor autophosphorylation, reduced expression and translocation of insulin-responsive glucose transporters and defects of the insulin signalling pathway distal to the insulin receptor. These defects await full characterization. Insulin-sensitizing agents can reverse many of the effects of insulin resistance and may have a future place in the treatment of polycystic ovarian syndrome and other conditions associated with steroid-induced insulin resistance. Recognition and treatment of sex steroid-associated insulin resistance at an early stage in patients may reduce their risk of developing Type II (non-insulin-dependent) diabetes mellitus, hypertension and dyslipidaemia, and so may improve fertility and reduce cardiovascular risk. Here we review the interplay between sex steroids and insulin resistance, and consider the implications this has for clinical conditions.
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Bertolotto, Maria, Sébastien Lenglet, Nicolas Vuilleumier, Katia Galan, Sabrina Pagano, Vincent Braunersreuther, Graziano Pelli i in. "Receptor activator of NF-κB ligand (RANKL) increases the release of neutrophil products associated with coronary vulnerability". Thrombosis and Haemostasis 107, nr 01 (2012): 124–39. http://dx.doi.org/10.1160/th11-05-0324.
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SummaryThe “blood vulnerability”, resulting from the complex balance between serum molecules and inflammatory cell atherosclerotic activities, is a major determinant in the evaluation of the “global patient cardiovascular vulnerability”. In the present study, we focused on the role of the soluble receptor activator of nuclear factor kappa-B (NF-κB) ligand (RANKL, a potential marker of coronary calcification and vulnerability) in the release of neutrophilic proteases. Then, the association between these mediators and the degree of coronary calcification (assessed by coronary calcium score [CCS]) was investigated in 20 subjects (aged ≥65 years) asymptomatic for cardiovascular disease. Results showed that RANKL dose-dependently induced matrix metalloprotease (MMP)-8 and MMP-9 release from human primary neutrophils cultured in Teflon dishes (suspension condition, mimicking cells circulating in the blood stream). Conversely, when adherent to polystyrene, neutrophils became unresponsive to RANKL. RANKL did not influence the release of other neutrophilic products in suspension and adherence cultures as well as neutrophil migration. RANKL-induced release of MMPs was dependent on the activation of defined intracellular signalling pathways (PI3K/Akt and ERK1/2). In asymptomatic subjects, serum levels of RANKL, MMP-8 and MMP-9 positively correlated with CCS, reflecting a potential relationship between circulating RANKL and coronary calcification. In conclusion, RANKL increased the release of neutrophilic products potentially related to the “blood” vulnerability via defined intracellular pathways. Serum levels of RANKL might represent a potential biomarker of coronary calcification and related cardiovascular risk.
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Pepe, Sara, Márta Korbonits i Donato Iacovazzo. "Germline and mosaic mutations causing pituitary tumours: genetic and molecular aspects". Journal of Endocrinology 240, nr 2 (luty 2019): R21—R45. http://dx.doi.org/10.1530/joe-18-0446.
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While 95% of pituitary adenomas arise sporadically without a known inheritable predisposing mutation, in about 5% of the cases they can arise in a familial setting, either isolated (familial isolated pituitary adenoma or FIPA) or as part of a syndrome. FIPA is caused, in 15–30% of all kindreds, by inactivating mutations in the AIP gene, encoding a co-chaperone with a vast array of interacting partners and causing most commonly growth hormone excess. While the mechanisms linking AIP with pituitary tumorigenesis have not been fully understood, they are likely to involve several pathways, including the cAMP-dependent protein kinase A pathway via defective G inhibitory protein signalling or altered interaction with phosphodiesterases. The cAMP pathway is also affected by other conditions predisposing to pituitary tumours, including X-linked acrogigantism caused by duplications of the GPR101 gene, encoding an orphan G stimulatory protein-coupled receptor. Activating mosaic mutations in the GNAS gene, coding for the Gα stimulatory protein, cause McCune–Albright syndrome, while inactivating mutations in the regulatory type 1α subunit of protein kinase A represent the most frequent genetic cause of Carney complex, a syndromic condition with multi-organ manifestations also involving the pituitary gland. In this review, we discuss the genetic and molecular aspects of isolated and syndromic familial pituitary adenomas due to germline or mosaic mutations, including those secondary to AIP and GPR101 mutations, multiple endocrine neoplasia type 1 and 4, Carney complex, McCune–Albright syndrome, DICER1 syndrome and mutations in the SDHx genes underlying the association of familial paragangliomas and phaeochromocytomas with pituitary adenomas.
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Beberok, Artur, Zuzanna Rzepka, Jakub Rok, Klaudia Banach i Dorota Wrześniok. "UVA Radiation Enhances Lomefloxacin-Mediated Cytotoxic, Growth-Inhibitory and Pro-Apoptotic Effect in Human Melanoma Cells through Excessive Reactive Oxygen Species Generation". International Journal of Molecular Sciences 21, nr 23 (25.11.2020): 8937. http://dx.doi.org/10.3390/ijms21238937.
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Melanoma, the most dangerous type of cutaneous neoplasia, contributes to about 75% of all skin cancer-related deaths. Thus, searching for new melanoma treatment options is an important field of study. The current study was designed to assess whether the condition of mild and low-dose UVA radiation augments the lomefloxacin-mediated cytotoxic, growth-inhibitory and pro-apoptotic effect of the drug in melanoma cancer cells through excessive oxidative stress generation. C32 amelanotic and COLO829 melanotic (BRAF-mutant) melanoma cell lines were used as an experimental model system. The combined exposure of cells to both lomefloxacin and UVA irradiation caused higher alterations of redox signalling pathways, as shown by intracellular reactive oxygen species overproduction and endogenous glutathione depletion when compared to non-irradiated but lomefloxacin-treated melanoma cells. The obtained results also showed that lomefloxacin decreased both C32 and COLO829 cells’ viability in a concentration-dependent manner. This effect significantly intensified when melanoma cells were exposed to UVA irradiation and the drug. For melanoma cells exposed to lomefloxacin or lomefloxacin co-treatment with UVA irradiation, the concentrations of the drug that decreased the cells’ viability by 50% (EC50) were found to be 0.97, 0.17, 1.01, 0.18 mM, respectively. Moreover, we found that the redox imbalance, mitochondrial membrane potential breakdown, induction of DNA fragmentation, and changes in the melanoma cells’ cell cycle distribution (including G2/M, S as well as Sub-G1-phase blockade) were lomefloxacin in a dose-dependent manner and were significantly augmented by UVA radiation. This is the first experimental work that assesses the impact of excessive reactive oxygen species generation upon UVA radiation exposure on lomefloxacin-mediated cytotoxic, growth-inhibitory and pro-apoptotic effects towards human melanoma cells, indicating the possibility of the usage of this drug in the photochemotherapy of malignant melanoma as an innovative medical treatment option which could improve the effectiveness of therapy. The obtained results also revealed that the redox imbalance intensification mediated by the phototoxic potential of fluoroquinolones may be considered as a more efficient treatment model of malignant melanoma and may constitute the basis for the development of new compounds with a high ability to excessive oxidative stress generation upon UVA radiation in cancer cells.
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Müller, Markus P. "Law without law: from observer states to physics via algorithmic information theory". Quantum 4 (20.07.2020): 301. http://dx.doi.org/10.22331/q-2020-07-20-301.
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According to our current conception of physics, any valid physical theory is supposed to describe the objective evolution of a unique external world. However, this condition is challenged by quantum theory, which suggests that physical systems should not always be understood as having objective properties which are simply revealed by measurement. Furthermore, as argued below, several other conceptual puzzles in the foundations of physics and related fields point to limitations of our current perspective and motivate the exploration of an alternative: to start with the first-person (the observer) rather than the third-person perspective (the world).In this work, I propose a rigorous approach of this kind on the basis of algorithmic information theory. It is based on a single postulate: that universal induction determines the chances of what any observer sees next. That is, instead of a world or physical laws, it is the local state of the observer alone that determines those probabilities. Surprisingly, despite its solipsistic foundation, I show that the resulting theory recovers many features of our established physical worldview: it predicts that it appears to observers as if there was an external world that evolves according to simple, computable, probabilistic laws. In contrast to the standard view, objective reality is not assumed on this approach but rather provably emerges as an asymptotic statistical phenomenon. The resulting theory dissolves puzzles like cosmology's Boltzmann brain problem, makes concrete predictions for thought experiments like the computer simulation of agents, and suggests novel phenomena such as ``probabilistic zombies'' governed by observer-dependent probabilistic chances. It also suggests that some basic phenomena of quantum theory (Bell inequality violation and no-signalling) might be understood as consequences of this framework.
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Akarasereenont, Pravit, Kitirat Techatrisak, Sirikul Chotewuttakorn i Athiwat Thaworn. "The Induction of Cyclooxygenase-2 in IL-1β-Treated Endothelial Cells is Inhibited by Prostaglandin E2 through cAMP". Mediators of Inflammation 8, nr 6 (1999): 287–94. http://dx.doi.org/10.1080/09629359990298.
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Prostaglandins (PGS) have numerous cardiovascular and inflammatory effects. Cyclooxygenase (COX), which exists as COX-1 and COX-2 isoforms, is the first enzyme in the pathway in which arachidonic acid is converted to PGs. Prostaglandin E2 (PGE2) exerts a variety of biological activities for the maintenance of local homeostasis in the body. Elucidation of PGE2 involvement in the signalling molecules such as COX could lead to potential therapeutic interventions. Here, we have investigated the effects of PGE2 on the induction of COX-2 in human umbilical vein endothelial cells (HUVEC) treated with interleukin-1β (IL-1β 1 ng/ml). COX activity was measured by the production of 6-keto-PGF1α, PGE2, PGF2α and thromboxane B2 (TXB2) in the presence of exogenous arachidonic acids (10 μM for 10 min) using enzyme immunoassay (EIA). COX-1 and COX-2 protein was measured by immunoblotting using specific antibody. Untreated HUVEC contained only COX-1 protein while IL-1β treated HUVEC contained COX-1 and COX-2 protein. PGE2 (3 μM for 24 h) did not affect on COX activity and protein in untreated HUVEC. Interestingly, PGE2 (3 μM for 24 h) can inhibit COX-2 protein, but not COX-1 protein, expressed in HUVEC treated with IL1 β. This inhibition was reversed by coincubation with forskolin (100 μM). The increased COX activity in HUVEC treated with IL-1β was also inhibited by PGE2 (0.03, 0.3 and 3 μM for 24 h) in a dose-dependent manner. Similarly, forskolin (10, 50 or 100 μM) can also reverse the inhibition of PGE2 on increased COX activity in IL-1β treated HUVEC. The results suggested that (i) PGE2 can initiate negative feedback regulation in the induction of COX-2 elicited by IL-1β in endothelial cells, (ii) the inhibition of PGE2 on COX-2 protein and activity in IL-1β treated HUVEC is mediated by cAMP and (iii) the therapeutic use of PGE2 in the condition which COX-2 has been involved may have different roles.
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Hazlerigg, D. G., M. H. Hastings i P. J. Morgan. "The recovery of ovine pars tuberalis cells from melatonin-induced sensitization is a slow, protein synthesis-dependent phenomenon". Journal of Endocrinology 142, nr 1 (lipiec 1994): 127–38. http://dx.doi.org/10.1677/joe.0.1420127.
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Abstract The pars tuberalis (PT) of the anterior pituitary is characterized by the presence of a high concentration of melatonin receptors, and acute exposure of cells from this tissue to melatonin inhibits the accumulation of cyclic AMP (cAMP) stimulated by forskolin. Conversely, exposure of ovine PT (oPT) cells to melatonin for periods of up to 16 h causes a progressive increase in subsequent basal and forskolin-stimulated production of cAMP. These observations are consistent with the possibility that the PT is involved in the mediation of melatonin-dependent phenomena in mammals. If the chronic effects of exposure to melatonin are indeed functionally significant, then one would anticipate that those responses of oPT cells known to be dependent upon levels of cAMP would also show an enhanced response to stimulation following prolonged exposure to the hormone. In the present study, the activation of cAMP-dependent protein kinase and the synthesis of secretory protein by oPT cells were found to be sensitized by prolonged exposure to physiological concentrations of melatonin. In the case of the synthesis of secretory protein this effect of melatonin was confined to those proteins whose synthesis has been shown to be sensitive to melatonin in acute experiments. These observations support the hypothesis that melatonin-induced sensitization modulates the putative biosynthetic and secretory function of the PT. The present study also examined the mechanism of sensitization of oPT cells by melatonin. The development of sensitization was not affected by simultaneous exposure of oPT cells to forskolin (1 μm) during pretreatment with melatonin. This observation suggests that melatonin-induced sensitization occurs independently of the established acute effects of the hormone on cAMP levels in oPT cells. Since no effects of melatonin upon any other signalling cascade have been observed in these cells, the most plausible explanation for this finding is that sensitization is a direct consequence of prolonged activation of melatonin receptors. Such a mechanism might be linked to the partial down-regulation of melatonin receptors known to occur in oPT cells in response to prolonged exposure to the hormone. In order to test this hypothesis further, the process of recovery from the sensitizing effects of melatonin was examined. The recovery of oPT cells from the sensitizing effects of exposure to melatonin (100 pm, 16 h) took place gradually and, even after an interval of 16 h, cells that had previously been exposed to melatonin for 16 h remained sensitized to approximately 20% of the extent seen immediately following pretreatment with melatonin for 16 h. In contrast to the previously reported insensitivity of the development of sensitization to the protein synthesis inhibitor, cycloheximide, the recovery of oPT cells from melatonin-induced sensitization was completely blocked by cycloheximide (10 μg/ml). Taken together, these observations are consistent with the hypothesis that melatonin-induced sensitization of oPT cells is the result of a reduction in levels of certain as yet unidentified protein(s), involved in the tonic inhibition of adenylate cyclase activity, occurring in parallel with the down-regulation of melatonin receptors, and that, conversely, the resynthesis of these factor(s) is a prerequisite for the return of oPT cells to the desensitized condition. Journal of Endocrinology (1994) 142, 127–138
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Toschi, P., D. Iuso, D. A. Anzalone, M. Czernik, G. Ptak i P. Loi. "343 DIRECT EXPRESSION OF PLURIPOTENCY MARKERS IN CULTURED SOMATIC CELLS BY SMALL REPROGRAMMING MOLECULES". Reproduction, Fertility and Development 27, nr 1 (2015): 260. http://dx.doi.org/10.1071/rdv27n1ab343.
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The differentiate state of the cell may be reversed by a process called reprogramming. To date, a totipotent status is conferred to a somatic cell by nuclear transfer (SCNT) and a condition of pluripotency is conferred by induced expression of defined factors (iPSC). While the restoration of full totipotency by SCNT is rarely achieved, pluripotency by Yamanaka's factors (Oct4, c-myc, Sox-2, Klf4) is inducible, although with low efficiency, in a large set of cell in different animal models. However, the isolation of iPSC requires complex technical skills and time-consuming protocols. In our laboratory we have observed that the simple expansion of fibroblasts in culture switches on pluripotency markers such as Oct4 and Nanog (Anzalone et al. 2015 Reprod. Fertil. Dev. IETS Abstract 344). CHIR99021 is a small molecule, targeting the Wnt/β-catenin signalling pathway, which is used for stem cell culture (Li et al. 2009). CHIR99021 acts as selective inhibitor of both isoform of GSK3 α/β regulating cellular proliferation and differentiation. In this work we tested the hypothesis that the exposure to a small reprogramming molecule (CHIR99021) induces pluripotency marker expression in primary cultures of somatic cells. Sheep and mouse primary fibroblasts cultured in low oxygen and induced to enter GO (low serum, 0.5% FBS for 5 days, <3% cell proliferation in our conditions) were treated with different CHIR concentrations (from 2.5 to 5 µM) for different time periods (from 1 to 5 days) in order to test the proper concentration and to exclude any cytotoxic effects. Nuclear reprogramming was assessed in treated and control cells by analysing β-catenin and oct4, nanog, sox2, klf4, and c-myc expression by immuno-detection and PCR. We found that CHIR interferes with β-catenin pathway in both sheep and mouse fibroblast in a time- and dose-dependent manner; the best results were obtained using 3 µM of CHIR for 3 days. Western blot analysis confirmed that CHIR treatment leads to an increased cellular level of β-catenin; furthermore, pluripotency marker expression (protein and mRNA) was increased (P = 0.023 nonparametric Mann-Whitney test) in CHIR-treated cells compared to controls. These observations, confirmed in both the experimental models, indicate that treatment with a small molecule inhibitor interfering with glucose metabolism induces the expression of pluripotency marker in somatic cells.
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Kim, Il-Sup, Woong Choi, Jonghyeon Son, Jun Hyuck Lee, Hyoungseok Lee, Jungeun Lee, Seung Chul Shin i Han-Woo Kim. "Screening and Genetic Network Analysis of Genes Involved in Freezing and Thawing Resistance in DaMDHAR—Expressing Saccharomyces cerevisiae Using Gene Expression Profiling". Genes 12, nr 2 (3.02.2021): 219. http://dx.doi.org/10.3390/genes12020219.
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The cryoprotection of cell activity is a key determinant in frozen-dough technology. Although several factors that contribute to freezing tolerance have been reported, the mechanism underlying the manner in which yeast cells respond to freezing and thawing (FT) stress is not well established. Therefore, the present study demonstrated the relationship between DaMDHAR encoding monodehydroascorbate reductase from Antarctic hairgrass Deschampsia antarctica and stress tolerance to repeated FT cycles (FT2) in transgenic yeast Saccharomyces cerevisiae. DaMDHAR-expressing yeast (DM) cells identified by immunoblotting analysis showed high tolerance to FT stress conditions, thereby causing lower damage for yeast cells than wild-type (WT) cells with empty vector alone. To detect FT2 tolerance-associated genes, 3′-quant RNA sequencing was employed using mRNA isolated from DM and WT cells exposed to FT (FT2) conditions. Approximately 332 genes showed ≥2-fold changes in DM cells and were classified into various groups according to their gene expression. The expressions of the changed genes were further confirmed using western blot analysis and biochemical assay. The upregulated expression of 197 genes was associated with pentose phosphate pathway, NADP metabolic process, metal ion homeostasis, sulfate assimilation, β-alanine metabolism, glycerol synthesis, and integral component of mitochondrial and plasma membrane (PM) in DM cells under FT2 stress, whereas the expression of the remaining 135 genes was partially related to protein processing, selenocompound metabolism, cell cycle arrest, oxidative phosphorylation, and α-glucoside transport under the same condition. With regard to transcription factors in DM cells, MSN4 and CIN5 were activated, but MSN2 and MGA1 were not. Regarding antioxidant systems and protein kinases in DM cells under FT stress, CTT1, GTO, GEX1, and YOL024W were upregulated, whereas AIF1, COX2, and TRX3 were not. Gene activation represented by transcription factors and enzymatic antioxidants appears to be associated with FT2-stress tolerance in transgenic yeast cells. RCK1, MET14, and SIP18, but not YPK2, have been known to be involved in the protein kinase-mediated signalling pathway and glycogen synthesis. Moreover, SPI18 and HSP12 encoding hydrophilin in the PM were detected. Therefore, it was concluded that the genetic network via the change of gene expression levels of multiple genes contributing to the stabilization and functionality of the mitochondria and PM, not of a single gene, might be the crucial determinant for FT tolerance in DaMDAHR-expressing transgenic yeast. These findings provide a foundation for elucidating the DaMDHAR-dependent molecular mechanism of the complex functional resistance in the cellular response to FT stress.
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Gattazzo, Cristina, Veronica Martini, Federica Frezzato, Valentina Trimarco, Elisa Ave, Samuela Carraro, Andrea Visentin, Gianpietro Semenzato i Livio Trentin. "Cortactin Expression Is Tightly Connected to B-Cell Chronic Lymphocytic Leukemia Aggressiveness". Blood 120, nr 21 (16.11.2012): 4561. http://dx.doi.org/10.1182/blood.v120.21.4561.4561.
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Abstract Abstract 4561 Background. Cortactin is an ubiquitous actin-binding protein, encoded by EMS1 gene and localized in chromosome 11q13 region. This protein is expressed in nearly all mammalian tissues and mostly localizes to dynamic actin structures. As a consequence, cortactin is involved in regulating several actin-dependent processes, including lamellipodium protrusion, trafficking of the key invadopodia proteases and intracellular transducer downstream to kinase-mediated cell signalling upon phosphorylation by Src and Syk tyrosine kinase families. Cortactin is over-expressed in several tumors, such as esophageal squamous cell carcinoma, head and neck squamous cell carcinoma and gastric carcinoma, and so tied to tumor aggressiveness by the promotion of cell invasion and metastasis. We previously showed that cortactin is over-expressed also in neoplastic B cells of patients with B-Cell Chronic Lymphocytic Leukemia (B-CLL). In the present study we investigated the regulation of cortactin activity by the Src kinase Lyn in neoplastic B-CLL cells and the biological implications of cortactin overexpression in this leukemia. Methods. Twenty patients and ten normal controls were enrolled. Informed consent was obtained from all patients according to the Declaration of Helsinki. CD19+ lymphocytes were purified from peripheral blood by negative selection using the RosetteSep cells isolation kit (StemCell Technologies). Cortactin localization was performed by Confocal Microscope analysis at basal condition, in presence of the chemotactic stimulus CXCL12 and Src kinase inhibitor PP2. Lyn kinase and cortactin phosphorylation levels were evaluated by western blotting analysis. Migration assay was performed using 3 μm pore filters (Transwell Permeable Supports) in the presence of CXCL12, Src kinase inhibitor PP2 and after cortactin silencing. Results. We found that cortactin localization is regulated by Lyn kinase through its phosphorylation. In CLL cells, cortactin was over-phosphorylated and it did not co-localize with actin, as compared to normal cells. PP2-inhibition of Lyn decreased cortactin phosphorylation and triggered its co-localization with actin. Cortactin over-expression proved to be associated to the increased B-CLL spreading through Lyn activity. In fact, not only cortactin over-expression correlated with leukemic cell increased response to CXCL12 (r = 0.9), but also the inhibition of cortactin activity, through PP2 inhibitor or cortactin silencing, drastically reduced neoplastic cell migration after chemotactic triggering. Conclusions. These results suggest that cortactin is involved in aggressiveness and spreading of B-CLL cells and that Lyn-cortactin axis could represent an alternative target for the development of new therapeutic strategies. Disclosures: No relevant conflicts of interest to declare.
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Li, J., D. Abegg, L. Malinovska, M. Rudnik, O. Distler, P. Błyszczuk, P. Picotti i G. Kania. "AB0135 PROTEIN CONFORMATIONAL CHANGES AND FUNCTIONAL ALTERATIONS IN DERMAL FIBROBLASTS FROM PATIENTS WITH SYSTEMIC SCLEROSIS". Annals of the Rheumatic Diseases 81, Suppl 1 (23.05.2022): 1197.1–1197. http://dx.doi.org/10.1136/annrheumdis-2022-eular.2710.
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BackgroundDespite intensive studies and clinical trials, there is still no available precise diagnostic tool and treatment of the patients affected by systemic sclerosis (SSc). Proteopathies are diseases characterized by the production of aberrant conformers of certain proteins that lead to a disturbance of their cellular functions and disease. It is believed that the structure of a protein is principally responsible for its function. By identifying altered protein structures on a proteome-wide scale, there is a possibility to detect protein functional changes.ObjectivesTo screen for changes in the protein conformation and to correlate with cell function in SSc dermal fibroblasts compared to fibroblasts from healthy donors (HC) using a novel approach of limited proteolysis followed by functional assays.MethodsDiffuse cutaneous SSc and HC dermal fibroblasts were used for recently established Limited Proteolysis-coupled Mass-Spectrometry (Lip-MS)[1] to examine protein structural alterations in a proteome-wide scale. A change in conformation was defined as having a foldchange greater than 1 or smaller than -1 and a significant p-value of -log10 > 1.3 (≤0.05). Further, the responsive signalling targets in these cells, including the NF-κB-dependent pathway and energy metabolism, were evaluated. Fibroblasts were stimulated with inflammatory cytokines, highly relevant in SSc, including TNFα, IL-1β, TGF-β, IL-17A, and a combination of IL-17A and TGF-β. To examine the NF-κB activity, cells were transduced with a pseudo-typed HIV-1-based lentiviral vector. The measurements of luciferase signal were analysed. RT-qPCR was used to assess the expression of NF-κB-dependent genes for non-transduced cells. ATP measurements were analysed and presented as the amount of luminescent signal.ResultsLiP-MS analysis detected 53263 common peptides in SSc (n=6) and HC fibroblasts (n=6), of which 41 peptides showed conformational changes in SSc fibroblasts in comparison with HC fibroblasts. The 41 conformationally altered peptides showed significant enrichment in GO pathways for: biological processes (9), molecular function (7) and cellular components (21). SAE1, CTNND1, CDC37, and PPP1R13L were related to the NF-κB-dependent pathways, while ATP5A1, GSTM1, PCK2, ANPEP, GM2A, GNS, CAD, ACOT2 were connected with metabolic processes. There was a tendency of lower levels of mRNA RELA, NFKBIA, MMP1 and TNC expression levels in untreated and stimulated SSc fibroblasts (n=6) compared to HC fibroblasts (n=6). The assessment of the NF-κB activity in untreated SSc fibroblasts (n=9) showed a trend to lower fold change compared to HC fibroblasts (n=9) (0.63 vs 1, SE 0.19, p=0.07). A statistically significant difference between SSc (n=8) and HC (n=8) fibroblasts was found in TGF-β stimulated fibroblasts (0.64 vs 1, SE 0.16, p=0.046). SSc fibroblasts (n=9) showed a lower ATP level compared to HC fibroblasts (n=9) in untreated condition (0.82 vs 1, SE 0.09, p=0.07), after stimulation with IL-1β (0.85 vs 1, SE 0.08, p=0.07) and TGF-β (0.81 vs 1, SE 0.09, p=0.05). Of note, a statistically significant difference between SSc and HC fibroblasts was found in IL-17A stimulated cells (0.82 vs 1, SE 0.07, p=0.02).ConclusionLiP-MS approach allowed for the identification of conformational changes in SSc fibroblast mainly related to signal transduction and metabolic pathways. Confirmatory functional studies showed deregulated NF-κB activity and ATP levels in SSc fibroblasts. Therefore, LiP-MS approach may create a distinctive opportunity to discover new disease biomarkers and functionally transformed pathways. This method may advance therapeutical approaches, where only structurally altered proteins could be specifically targeted, without interfering with non-changed proteins.References[1]Schopper S, Kahraman A, Leuenberger P, Feng Y, Piazza I, Müller O, Boersema PJ, Picotti P. Measuring protein structural changes on a proteome-wide scale using limited proteolysis-coupled mass spectrometry. Nat Protoc. 2017 Nov;12(11):2391-2410.Disclosure of InterestsNone declared
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Wheeldon, Amie, Katarzyna Kwiatkowska, Paweł Szymański i Tomasz S. Osiejuk. "Male and female songs propagation in a duetting tropical bird species in its preferred and secondary habitat". PLOS ONE 17, nr 10 (3.10.2022): e0275434. http://dx.doi.org/10.1371/journal.pone.0275434.
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Acoustic signals produced by animals must transmit through the environment to reach potential receivers and change their behaviour. Both the environment (vegetation, air properties, other animals) and the form of the signal affect the propagation process. Here we investigated how the transmission of different song types of a duetting songbird species inhabiting an extreme environment within African montane forest, varies between males and females as well as different types of micro-habitats. We hypothesised that male and female songs would have different transmission properties, reflecting known differences in signal form and function. We analysed signal-to-noise ratio (SNR), excess attenuation (EA) and tail-to-signal ratio (TSR) of songs of male and female Yellow-breasted Boubous (Laniarius atroflavus) that were played and re-recorded in a range of sites representing the species-typical habitats. We found significant effects of distance, site (habitat) and sex reflected in all three measures of sound degradation. The clearest, primarily distance-dependent pattern was found for SNR of songs propagated in level forest site. EA was substantially higher in shrubs than in forest habitats, while TSR reflecting longer echoes appeared at longer distances in forest sites. Thus, Yellow-breasted Boubou songs are better propagated in forests than in disturbed sites covered with shrubs. We found that all male song types used for broadcast singing propagated farther than female songs, with significantly higher SNR at all distances. The different male song types which are known to have different functions, also demonstrated a differentiated pattern of propagation reflecting their functionality. All signals that were tested propagated the furthest in the ideal condition described as forest with a level terrain. Signals degraded much faster during transmission through shrubs regrowing after forest burning. On this site, the differences in the propagation of male and female songs, as well as the differences between male song types, were relatively least pronounced. Transmission in typical mountain forest among streams and with substantial terrain variation revealed that degradation pattern in such habitat could be perturbed in a non-linear way. Streams acting as a source of high noise level also negatively affected transmission and may strongly limit the perception of birds staying close to them. However, stream noise did not affect sex differences in song propagation as was found for the site located in shrubs. Male songs showed more efficient transmission through all habitats (least in the shrubs) than female song. These differences were the result of male songs having a whistle structure that is better adapted for long-range propagation than the atonal, wideband frequency female vocalisations. Results support the idea that signals of males of the Yellow-breasted Boubous evolved under the pressure of long-range communication both with rivals and females, while females of the species are much more focused on within-pair communication or signalling together with their partner. The consequence of deforestation resulting in pushing back territories to the forest remnants along streams may be a shortening of the song’s active range, in particular, in females.
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Martelli, M. P., V. Pettirossi, N. Manes, A. Liso, F. Mezzasoma, F. Cecchetti, M. F. De Marco i in. "Selective Silencing of the NPM1 Mutant Protein and Apoptosis Induction upon ATRA In Vitro Treatment of AML Cells Carrying NPM1 Mutations." Blood 110, nr 11 (16.11.2007): 868. http://dx.doi.org/10.1182/blood.v110.11.868.868.
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Abstract We previously identified a new AML category carrying NPM1 mutations which lead to aberrant cytoplasmic expression of the nucleolar protein NPM1, hence the term NPMc+ AML[Falini et al, NEJM 2005]. This leukemia accounts for about one-third of adult AML and shows distinctive biological and clinical features[Falini et al, Blood 2007]. Notably, AML carrying NPM1 mutations in the absence of FLT3-ITD are characterized by a favourable prognosis. However, still a proportion of NPMc+ AML cannot be cured by conventional treatments and new therapeutic strategies need to be explored. We previously identified OCI/AML3 as the only human AML cell line carrying cytoplasmic mutated NPM (type A) in the absence of FLT3-ITD[Quentmeier et al, Leukemia 2005]. Because of these features and the ability to engraft in NOD/SCID mice, the OCI-AML3 represents a remarkable tool for the study of NPMc+ AML. Previous findings that ATRA exerts growth inhibitory effects on the OCI/AML3 prompt us to investigate the molecular mechanisms underlying the response to ATRA, with focus on the NPM mutant protein. As cellular model for our studies, we also used primary leukemia cells originated from a patient with NPMc+ AML (mutation A) bearing FLT3-ITD (Mont1) that have been propagated in NOD/SCID mice for 5 years without loss of initial characteristics. Early cell cycle arrest and proapoptotic effects of pharmacological doses of ATRA were confirmed in both cellular models in vitro. Morphological signs of differentiation were not evident. Western blot analysis using specific antibodies showed marked downregulation of the leukemic NPM1 mutant protein upon ATRA treatment, preceding apoptosis activation. On the other hand, wild-type NPM1 protein levels remained unchanged, leading to a condition of NPM1 haploinsufficiency. Semi-quantitative RT-PCR for NPM mutant A showed no change in mRNA expression following treatment, suggesting a regulation of the NPM mutant protein expression at post-transcriptional level. Indeed, concomitant treatment with proteasome-inhibitors partly reverted this effect. Downregulation of NPM mutant protein preceded activation of caspase-8 and caspase-3, PARP-cleavage and Bax activation. No NF-kB activation was observed upon ATRA treatment. Activation of the p53-dependent pathway was a later event, as expected in conditions of NPM1 haploinsufficiency. Importantly, these results were confirmed in the primary NPMc+ AML cells from patient Mont1. Activation of caspase-8 suggests that the response to ATRA in NPMc+ AML cells may be mediated through the death receptor pathway. Although protein levels of TRAIL, TRAIL receptors and TNF-alpha receptors seem to be unaffected, it might be possible that the NPM1 mutant protein modulates the signalling through death cell receptors. Analysis of ATRA-induced transcriptome and proteome modifications in NPMc+ AML is ongoing and will be also presented, as well as further pre-clinical studies on patients’ primary AML cells and in NOD/SCID mice. In conclusion, our data suggest that NPM mutant protein might be involved in the in vitro response to ATRA in AML cells carrying NPM1 mutations. Figure Figure
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Romano, E., I. Rosa, B. S. Fioretto, D. Giuggioli, M. Manetti i M. Matucci-Cerinic. "AB0132 STIMULATION OF SOLUBLE GUANYLATE CYCLASE (sGC) FOSTERS ANGIOGENESIS AND BLUNTS ENDOTHELIAL-TO-MESENCHYMAL TRANSITION (EndoMT) OF SYSTEMIC SCLEROSIS (SSc) DERMAL MICROVASCULAR ENDOTHELIAL CELLS". Annals of the Rheumatic Diseases 81, Suppl 1 (23.05.2022): 1196.1–1196. http://dx.doi.org/10.1136/annrheumdis-2022-eular.2362.
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BackgroundIn SSc, early abnormalities in microvessel morphology and angiogenic impairment in parallel advance with the development of tissue fibrosis orchestrated by myofibroblasts. Increasing evidence suggests that the EndoMT process, in which endothelial cells transdifferentiate into profibrotic myofibroblasts, may take centre stage in SSc pathogenesis [1,2]. sGC is an enzyme regulating cell growth/proliferation and vascular tone/remodelling by catalysing the production of cyclic guanosine monophosphate. Previous studies reported that sGC stimulation inhibits TGFβ-induced fibroblast-to-myofibroblast differentiation and collagen synthesis by blocking non-canonical ERK-dependent TGFβ signalling, and that sCG stimulators (sGCS) may exert antifibrotic effects in experimental models of fibrotic disorders.ObjectivesTo investigate the possible modulatory effects of sGC stimulation on impaired angiogenesis and EndoMT of SSc dermal microvascular endothelial cells (SSc-MVECs).MethodsTo evaluate the effects of treatment with sGCS on endothelial cell viability/proliferation, 5 lines of SSc-MVECs and 5 lines of healthy dermal MVECs (H-MVECs) were challenged with sGCS (here MK-2947) and assayed with both annexin V/PI flow cytometry and WST-1. To analyse the modulation of angiogenesis by sGCS, SSc-MVECs were challenged with MK-2947 and subsequently tested for wound healing and capillary-like tube formation capabilities. To study the effects of MK-2947 on EndoMT, the same cells were assayed for the expression of endothelial and mesenchymal/myofibroblast markers by quantitative real-time PCR, western blotting and immunofluorescence, as well as for their contractile ability by collagen gel contraction assay. Phosphorylation of ERK1/2 was assessed by western blotting.ResultsTreatment with MK-2947 did not affect viability/proliferation of H-MVECs, while it significantly increased the proliferation of SSc-MVECs (p<0.001 vs. basal). Compared to basal condition, the MK-2947 challenge ameliorated both wound healing capability (p<0.001) and angiogenic performance (number of nodes: p<0.01; segments: p<0.001; meshes: p<0.01; and junctions: p<0.001) of SSc-MVECs. Upon stimulation of sGC, SSc-MVECs exhibited increased gene expression of proangiogenic matrix metalloproteinase (MMP)-9 (p<0.05) and decreased expression of both antiangiogenic MMP-12 (p<0.05) and pentraxin-3 (p<0.001) respect to basal SSc-MVECs. A significant increase in both gene and protein expression of the endothelial markers CD31 and VE-cadherin, and a parallel decrease in the expression of the mesenchymal/myofibroblast markers α-SMA, S100A4, and type I collagen were found in MK-2947-treated SSc-MVECs. MK-2947 also downregulated the EndoMT-driving transcription factor SNAIL1 in SSc-MVECs. Stimulation with MK-2947 was able to significantly counteract the intrinsic ability of myofibroblast-like SSc-MVECs to contract collagen gels (p<0.001) and effectively reduce phosphorylated-ERK1/2 protein levels (p<0.01) respect to basal cells.ConclusionStimulation of sGC effectively ameliorates the angiogenic performance and blunts the pathogenic myofibroblast-like profibrotic phenotype of SSc-MVECs.References[1]Manetti M, et al. Endothelial-to-mesenchymal transition contributes to endothelial dysfunction and dermal fibrosis in systemic sclerosis. Ann Rheum Dis. 2017;76:924–34.[2]Romano E, et al. New insights into profibrotic myofibroblast formation in systemic sclerosis: when the vascular wall becomes the enemy. Life (Basel). 2021;11:610.Disclosure of InterestsEloisa Romano: None declared, Irene Rosa: None declared, Bianca Saveria Fioretto: None declared, Dilia Giuggioli: None declared, Mirko Manetti Speakers bureau: has received consulting fees or honorarium from MSD, Marco Matucci-Cerinic Speakers bureau: has received consulting fees or honorarium from Actelion, Janssen, Inventiva, Bayer, Biogen, Boehringer, CSL Behring, Corbus, Galapagos, Mitsubishi, Samsung, Regeneron, Acceleron, MSD, Chemomab, Lilly, Pfizer, Roche, Grant/research support from: has received consulting fees or honorarium from Actelion, Janssen, Inventiva, Bayer, Biogen, Boehringer, CSL Behring, Corbus, Galapagos, Mitsubishi, Samsung, Regeneron, Acceleron, MSD, Chemomab, Lilly, Pfizer, Roche