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Pelaprat, N., C. Brondino, G. Rigal und B. Boutevin. „Synthèse d'alkylphosphonates à longues chaines hydrocarbonées, modifications chimiques et applications—II. Addition de HP(O)(OEt)2 sur les alcènes et phosphonation directe d'halogénures d'alkyles“. European Polymer Journal 32, Nr. 6 (Juni 1996): 761–66. http://dx.doi.org/10.1016/0014-3057(95)00189-1.
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Zhu, Hongming, Aijun Sun, Yunzeng Zou und Junbo Ge. „Inducible Metabolic Adaptation Promotes Mesenchymal Stem Cell Therapy for Ischemia“. Arteriosclerosis, Thrombosis, and Vascular Biology 34, Nr. 4 (April 2014): 870–76. http://dx.doi.org/10.1161/atvbaha.114.303194.
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Objective— Ischemic tissue is an environment with limited oxygen and nutrition availability. The poor retention of mesenchymal stem cells (MSC) in ischemic tissues greatly limits their therapeutic potential. The aim of this study was to determine whether and how inducible metabolic adaptation enhances MSC survival and therapy under ischemia. Approach and Results— MSC were subjected to glycogen synthase 1–specific small interfering RNA or vehicle treatment, and then sublethal hypoxic preconditioning (HP) was applied to induce glycogenesis. The treated cells were subjected to ischemic challenge. The results exhibited that HP of MSC induced glycogen storage and stimulated glycogen catabolism and cellular ATP production, thereby preserving cell viability in long-term ischemia. In vivo study using the mouse limb ischemia model transplanted with HP or control MSC into the ischemic thigh muscles revealed a significant increased retention of MSC with glycogen storage associated with improved limb salvage, perfusion recovery and angiogenesis in the ischemic muscles. In contrast, glycogen synthesis inhibition significantly abolished these improvements. Further molecular analysis indicated that phosphoinositide 3-kinase/AKT, hypoxia-inducible factor-1, and glycogen synthase kinase-3β regulated expression of glycogenesis genes, including glucose transporter 1, hexokinase, phosphoglucomutase 1, glycogen synthase 1, and glycogen phosphorylase, thereby regulating glycogen metabolism of stem cell during HP. Conclusions— HP-induced glycogen storage improves MSC survival and therapy in ischemic tissues. Thus, inducible metabolic adaptation in stem cells may be considered as a novel strategy for potentiating stem cell therapy for ischemia.
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Wang, Li, Yuan Zhou, Jun Peng, Zhe Zhang, De-Jian Jiang und Yuan-Jian Li. „Role of endogenous nitric oxide synthase inhibitor in gastric mucosal injury“. Canadian Journal of Physiology and Pharmacology 86, Nr. 3 (März 2008): 97–104. http://dx.doi.org/10.1139/y08-003.
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To explore the role of the endogenous nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) in gastric mucosal injury, 3 models of gastric mucosal injury induced by ethanol, indomethacin, or cold stress were used in rats. The cultured human gastric mucosal epithelial cell line GES-1 infected by Helicobacter pylori (Hp) was selected to mimic human gastric mucosal injury. Gastric mucosal ulcer index (UI), levels of ADMA and NO, and activity of dimethylarginine dimethylaminohydrolase (DDAH) were determined in the mucosal injury models; in Hp-infected or ADMA-treated GES-1 cells, levels of ADMA, NO, and TNF-α and activity of DDAH were measured. The results showed that UI and levels of ADMA were markedly increased and accompanied by significantly decreased DDAH activity in the mucosal injury models. Incubation of GES-1 cells with Hp increased levels of TNF-α and ADMA and decreased activity of DDAH. Administration of ADMA also increased levels of TNF-α. The results suggest that ADMA plays an important role in facilitating gastric mucosal injury, an effect which is associated with inhibiting NO synthesis and inducing inflammatory reaction.
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Hoque, Sanzana, Yuki Kondo, Nodoka Sakata, Yusei Yamada, Madoka Fukaura, Taishi Higashi, Keiichi Motoyama et al. „Differential Effects of 2-Hydroxypropyl-Cyclodextrins on Lipid Accumulation in Npc1-Null Cells“. International Journal of Molecular Sciences 21, Nr. 3 (30.01.2020): 898. http://dx.doi.org/10.3390/ijms21030898.
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Niemann–Pick disease type C (NPC) is an autosomal recessive disorder characterized by abnormal accumulation of free cholesterol and sphingolipids in lysosomes. The iminosugar miglustat, which inhibits hexosylceramide synthesis, is used for NPC treatment, and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), a cyclic oligosaccharide derivative, is being developed to treat NPC. Moreover, therapeutic potential of 2-hydroxypropyl-γ-cyclodextrin (HP-γ-CD) was shown in NPC models, although its mechanism of action remains unclear. Here, we investigated the effects of HP-β-CD, HP-γ-CD, and their homolog 2-hydroxypropyl-α-cyclodextrin (HP-α-CD) on lipid accumulation in Npc1-null Chinese hamster ovary (CHO) cells compared with those of miglustat. HP-β-CD and HP-γ-CD, unlike HP-α-CD, reduced intracellular free cholesterol levels and normalized the lysosome changes in Npc1-null cells but not in wild-type CHO cells. In contrast, miglustat did not normalize intracellular free cholesterol accumulation or lysosome changes in Npc1-null cells. However, miglustat decreased the levels of hexosylceramide and tended to increase those of sphingomyelins in line with its action as a glucosylceramide synthase inhibitor in both Npc1-null and wild-type CHO cells. Interestingly, HP-β-CD and HP-γ-CD, unlike HP-α-CD, reduced sphingomyelins in Npc1-null, but not wild-type, cells. In conclusion, HP-β-CD and HP-γ-CD reduce the accumulation of sphingolipids, mainly sphingomyelins, and free cholesterol as well as lysosome changes in Npc1-null, but not in wild-type, CHO cells.
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Doherty, Neil C., Feifei Shen, Nigel M. Halliday, David A. Barrett, Kim R. Hardie, Klaus Winzer und John C. Atherton. „In Helicobacter pylori, LuxS Is a Key Enzyme in Cysteine Provision through a Reverse Transsulfuration Pathway“. Journal of Bacteriology 192, Nr. 5 (08.01.2010): 1184–92. http://dx.doi.org/10.1128/jb.01372-09.
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ABSTRACT In many bacteria, LuxS functions as a quorum-sensing molecule synthase. However, it also has a second, more central metabolic function in the activated methyl cycle (AMC), which generates the S-adenosylmethionine required by methyltransferases and recycles the product via methionine. Helicobacter pylori lacks an enzyme catalyzing homocysteine-to-methionine conversion, rendering the AMC incomplete and thus making any metabolic role of H. pylori LuxS (LuxSHp) unclear. Interestingly, luxS Hp is located next to genes annotated as cysK Hp and metB Hp, involved in other bacteria in cysteine and methionine metabolism. We showed that isogenic strains carrying mutations in luxS Hp, cysK Hp, and metB Hp could not grow without added cysteine (whereas the wild type could), suggesting roles in cysteine synthesis. Growth of the ΔluxS Hp mutant was restored by homocysteine or cystathionine and growth of the ΔcysK Hp mutant by cystathionine only. The ΔmetB Hp mutant had an absolute requirement for cysteine. Metabolite analyses showed that S-ribosylhomocysteine accumulated in the ΔluxS Hp mutant, homocysteine in the ΔcysK Hp mutant, and cystathionine in the ΔmetB Hp mutant. This suggests that S-ribosylhomocysteine is converted by LuxSHp to homocysteine (as in the classic AMC) and thence by CysKHp to cystathionine and by MetBHp to cysteine. In silico analysis suggested that cysK-metB-luxS were acquired by H. pylori from a Gram-positive source. We conclude that cysK-metB-luxS encode the capacity to generate cysteine from products of the incomplete AMC of H. pylori in a process of reverse transsulfuration. We recommend that the misnamed genes cysK Hp and metB Hp be renamed mccA (methionine-to-cysteine-conversion gene A) and mccB, respectively.
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Shih, Jui-Hu, Yow-Fu Tsai, I.-Hsun Li, Ming-Hua Chen und Yuahn-Sieh Huang. „Hp-s1 Ganglioside Suppresses Proinflammatory Responses by Inhibiting MyD88-Dependent NF-κB and JNK/p38 MAPK Pathways in Lipopolysaccharide-Stimulated Microglial Cells“. Marine Drugs 18, Nr. 10 (29.09.2020): 496. http://dx.doi.org/10.3390/md18100496.
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Hp-s1 ganglioside is isolated from the sperm of sea urchin (Hemicentrotus pulcherrimus). In addition to neuritogenic activity, the biological function of Hp-s1 in neuroinflammation is unknown. In this study, we investigated the anti-neuroinflammatory effect of Hp-s1 on lipopolysaccharide (LPS)-stimulated microglial cells. MG6 microglial cells were stimulated with LPS in the presence or absence of different Hp-s1 concentrations. The anti-inflammatory effect and underlying mechanism of Hp-s1 in LPS-activated microglia cells were assessed through a Cell Counting kit-8 assay, Western blot analysis, and immunofluorescence. We found that Hp-s1 suppressed not only the expression of inducible nitric oxide synthase and cyclooxygenase-2 but also the expression of proinflammatory cytokines, such as TNF-α, IL-1β, and IL-6. Hp-s1 inhibited the LPS-induced NF-κB signaling pathway by attenuating the phosphorylation and translocation of NF-κB p65 and by disrupting the degradation and phosphorylation of inhibitor κB-α (IκBα). Moreover, Hp-s1 inhibited the LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK). Hp-s1 also reduced the expression of myeloid differentiation factor 88 (MyD88) and TNF receptor-associated factors 6 (TRAF6), which are prerequisites for NF-κB and MAPKs activation. These findings indicated that Hp-s1 alleviated LPS-induced proinflammatory responses in microglial cells by downregulating MyD88-mediated NF-κB and JNK/p38 MAPK signaling pathways, suggesting further evaluation as a new anti-neuroinflammatory drug.
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Liu, Jie, Irene Ginis, Maria Spatz und John M. Hallenbeck. „Hypoxic preconditioning protects cultured neurons against hypoxic stress via TNF-α and ceramide“. American Journal of Physiology-Cell Physiology 278, Nr. 1 (01.01.2000): C144—C153. http://dx.doi.org/10.1152/ajpcell.2000.278.1.c144.
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Brief “preconditioning” ischemia induces ischemic tolerance (IT) and protects the animal brain from subsequent otherwise lethal ischemia. Identification of the signaling steps most proximal to the development of the IT will allow induction of the resistance to ischemia shortly after the onset of stroke. Animal studies demonstrate a key role of tumor necrosis factor-α (TNF-α) in induction of IT. The sphingolipid ceramide is known as a second messenger in many of the multiple effects of TNF-α. We hypothesized that ceramide could mediate IT. We demonstrate that preconditioning of rat cortical neurons with mild hypoxia protects them from hypoxia and O2-glucose deprivation injury 24 h later (50% protection). TNF-α pretreatment could be substituted for hypoxic preconditioning (HP). HP was attenuated by TNF-α-neutralizing antibody. HP and TNF-α pretreatment cause a two- to threefold increase of intracellular ceramide levels, which coincides with the state of tolerance. Fumonisin B1, an inhibitor of ceramide synthase, attenuated ceramide upregulation and HP. C-2 ceramide added to the cultures right before the hypoxic insult mimicked the effect of HP. Ceramide did not induce apoptosis. These results suggest that HP is mediated via ceramide synthesis triggered by TNF-α.
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Niepolski, Leszek, und Kamila Malinowska-Loba. „Association of Circulating Endothelial Nitric Oxide Synthase Levels with Phosphataemia in Patients on Haemodialysis“. Biomedicines 12, Nr. 3 (19.03.2024): 687. http://dx.doi.org/10.3390/biomedicines12030687.
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The amount of evidence indicates that hyperphosphataemia (HP) can induce endothelial damage and significantly impair endothelial nitric oxide synthase (eNOS) expression. There are no clinical studies that have assessed HP and its correlation with circulating eNOS concentration in patients with end-stage renal disease (ESRD). Our preliminary study aimed to evaluate the relationship between plasma inorganic phosphorus (P) levels and circulating plasma eNOS concentration in patients on haemodialysis (HD). A total of 50 patients on HD were enrolled to the study. They were divided into groups according to the tertiles of P. The examined HD group was also analysed and compared with controls as a whole group; then, the group was divided into patients with and without dyslipidaemia (D) as well as into those with and without type 2 diabetes mellitus (type 2 DM). A total of 26 age-matched healthy volunteers were included in the study as the control group. The plasma levels of eNOS in HD patients are reduced in comparison to those in healthy subjects. There was no difference in plasma eNOS concentrations between HD patients with type 2 DM and those without DM as well as between those with D and without D. In the entire group of HD patients, there were positive correlations between circulating levels of eNOS and plasma P concentrations. In HD patients with D, higher systolic and diastolic blood pressure were accompanied by decreased plasma eNOS concentrations. In conclusion, HP and high blood pressure appear to decrease the circulating eNOS levels. These findings demonstrate an additional negative impact of HP on eNOS activity.
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Huang, Ho-Shiang, Ming-Chieh Ma und Jun Chen. „Chronic l-arginine administration increases oxidative and nitrosative stress in rat hyperoxaluric kidneys and excessive crystal deposition“. American Journal of Physiology-Renal Physiology 295, Nr. 2 (August 2008): F388—F396. http://dx.doi.org/10.1152/ajprenal.00405.2007.
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Hyperoxaluric kidneys show an impaired diuretic response to acute infusion of l-arginine. In this study, we examined the chronic effect of l-arginine supplementation on CaOx crystal formation in hyperoxaluric rat kidneys. Eight groups were tested: control (received drinking water), L group (received l-arginine, 0.6%), LN group [received NG-nitro-l-arginine methyl ester (l-NAME, 10 mg/kg)], L + LN group (received l-arginine + l-NAME), HP group [received hydroxyl-l-proline (HP, 5%) mixed with chow to induce hyperoxaluria], L + HP group (received HP + l-arginine), HP + LN group, and L + HP + LN group. The duration was 42 days, and each group had eight animals. Urinary biochemistry and renal CaOx amounts were measured, as well as renal expressions of nitric oxide synthase (NOS) isoforms and NAD(P)H oxidase. The distribution of inducible NOS (iNOS), NAD(P)H oxidase, ED1-positive cells, and nitrotyrosine was examined by immunohistochemical and immunofluorescence studies, whereas superoxide production from the kidneys was examined by fluorescence spectrometric assay. Compared with the HP group, the L + HP group had excessive CaOx crystal accumulation and enhanced endothelial NOS (eNOS), iNOS, and NAD(P)H oxidase protein expression in the kidney. Urinary excretion of nitrotyrosine was markedly increased. Increased superoxide formation in the L + HP kidney was derived from NAD(P)H oxidase and uncoupled eNOS, and increased nitrotyrosine formation might derive from iNOS and ED1-positive cells that gathered around the CaOx crystals. l-NAME cotreatment (L + HP + LN group) reduced renal oxidative nitrosative stress and tubular damage, which were induced by L + HP. The results showed that chronic l-arginine treatment to the hyperoxaluric kidney with massive CaOx crystal deposition may have a toxic effect by enhancing intrarenal oxidative and nitrosative stress.
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Duin, Stam, Uitterdijk, Bartelds, Danser, Reiss, Duncker und Merkus. „Intervening with the Nitric Oxide Pathway to Alleviate Pulmonary Hypertension in Pulmonary Vein Stenosis“. Journal of Clinical Medicine 8, Nr. 8 (12.08.2019): 1204. http://dx.doi.org/10.3390/jcm8081204.
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Pulmonary hypertension (PH) as a result of pulmonary vein stenosis (PVS) is extremely difficult to treat. The ideal therapy should not target the high-pressure/low-flow (HP/LF) vasculature that drains into stenotic veins, but only the high-pressure/high-flow (HP/HF) vasculature draining into unaffected pulmonary veins, reducing vascular resistance and pressure without risk of pulmonary oedema. We aimed to assess the activity of the nitric oxide (NO) pathway in PVS during the development of PH, and investigate whether interventions in the NO pathway differentially affect vasodilation in the HP/HF vs. HP/LF territories. Swine underwent pulmonary vein banding (PVB; n = 7) or sham surgery (n = 6) and were chronically instrumented to assess progression of PH. Pulmonary sensitivity to exogenous NO (sodium nitroprusside, SNP) and the contribution of endogenous NO were assessed bi-weekly. The pulmonary vasodilator response to phosphodiesterase-5 (PDE5) inhibition was assessed 12 weeks after PVB or sham surgery. After sacrifice, 12 weeks post-surgery, interventions in the NO pathway on pulmonary small arteries isolated from HP/LF and HP/HF territories were further investigated. There were no differences in the in vivo pulmonary vasodilator response to SNP and the pulmonary vasoconstrictor response to endothelial nitric oxide synthase (eNOS) inhibition up to 8 weeks after PVB as compared to the sham group. However, at 10 and 12 weeks post-PVB, the in vivo pulmonary vasodilation in response to SNP was larger in the PVB group. Similarly, the vasoconstriction to eNOS inhibition was larger in the PVB group, particularly during exercise, while pulmonary vasodilation in response to PDE5 inhibition was larger in the PVB group both at rest and during exercise. In isolated pulmonary small arteries, sensitivity to NO donor SNP was similar in PVB vs. sham groups irrespective of HP/LF and HP/HF, while sensitivity to the PDE5 inhibitor sildenafil was lower in PVB HP/HF and sensitivity to bradykinin was lower in PVB HP/LF. In conclusion, both NO availability and sensitivity were increased in the PVB group. The increased nitric oxide sensitivity was not the result of a decreased PDE5 activity, as PDE5 activity was even increased. Some vasodilators differentially effect HP/HF vs. HP/LF vasculature.
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SARIYILDIZ, Aylin, Halil Mahir KAPLAN, Ergin ŞİNGİRİK und Erkan KOZANOGLU. „Hypericum perforatum ekstresinin siyatik sinir hasarı ile indüklenen periferik nöropati üzerindeki düzenleyici etkisi: fareler üzerinde deneysel bir çalışma“. Cukurova Medical Journal 48, Nr. 2 (30.06.2023): 513–21. http://dx.doi.org/10.17826/cumj.1259761.
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Purpose: The effect of Hypericum perforatum (HP), which is a medicinal plant, on sciatic nerve injury-induced peripheral neuropathy has been less studied so far. The current experimental study aimed to investigate the neuroprotective and antinociceptive effects of Hypericum perforatum (HP) extract on sciatic nerve injury-induced peripheral neuropathy in mice.
Materials and Methods: In the present study, 18 Balb/C albino mice were allocated equally into three groups. The first group was determined as controls, and no procedure was performed on these mice. Neuropathy was generated by the partial sciatic nerve ligation method on mice allocated to the second and third groups. Mice in the third group received HP extract at a dose of 70 mg/kg per day for fourteen days. Nociception (cold allodynia) was evaluated using the cold plate test at the end of the experimental period. Tumor necrosis factor –αlpha (TNF-α) and interleukin-6 (IL-6) in plasma; inducible nitric oxide synthase (iNOS), phospholipase A2, cyclooxygenase-2 (COX-2), nuclear factor-kappa B (NF-κB), caspase-3, Bcl-2, and Bax levels in sciatic nerve were measured by enzyme-linked immunosorbent assay test.
Results: Cold plate latencies (sec) of the neuropathy + HP, neuropathy, and control groups were 8.33 ± 0.67, 5.17 ± 0.60, and 13 ± 0.73, respectively. Plasma TNF-α, IL-6 levels, and sciatic nerve iNOS, COX-2, NF-κB, caspase-3, and Bax levels were significantly decreased after HP supplementation. Bcl-2 levels of the neuropathy + HP, neuropathy, and control groups were 9.92 ± 0.71, 5.37 ± 0.53, and 13.65 ± 0.68, respectively.
Conclusion: HP has improved oxidative, inflammatory, and apoptotic responses, as well as cytokine levels in plasma and sciatic nerves of mice. It has been concluded that HP provided neuroprotective, anti-inflammatory, and antinociceptive effects in experimental mice with sciatic nerve injury models, which is suggested to guide future studies on neuropathic pain management.
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Choi, Sung-Won, Dong-Hoon Bai, Ju-Hyun Yu und Chul Soo Shin. „Characteristics of the squalene synthase inhibitors produced by a Streptomyces species isolated from soils“. Canadian Journal of Microbiology 49, Nr. 11 (01.11.2003): 663–68. http://dx.doi.org/10.1139/w03-084.
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Microorganisms producing squalene synthase inhibitors were screened from soils. A high producer was selected and identified as a Streptomyces species. Two active inhibitors were obtained from culture broths via a series of purification processes involving solvent extraction, WK-10 cation-exchange column chromatography, HP-20 adsorption column chromatography, silica-gel column chromatography, preparative HPLC, and crystallization. The inhibitors were confirmed as macrolactins A and F with molecular weights of 402 by UV-absorption spectrometry, fast atom bombardment mass spectometry, and 13C- and 1H-NMR analyses. Kinetic results for macrolactins A and F showed that they appear to be noncompetitive inhibitors of rat liver squalene synthase with IC50 values of 1.66 and 1.53 µmol/L, respectively. Since mammalian squalene synthase was used, these inhibitors have significant potential as therapeutic agents for hyperlipemia and suppression of cholesterol biosynthesis.Key words: squalene synthase inhibitor, Streptomyces species, macrolactins A and F.
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Thomas, D. P., R. J. McCormick, S. D. Zimmerman, R. K. Vadlamudi und L. E. Gosselin. „Aging- and training-induced alterations in collagen characteristics of rat left ventricle and papillary muscle“. American Journal of Physiology-Heart and Circulatory Physiology 263, Nr. 3 (01.09.1992): H778—H783. http://dx.doi.org/10.1152/ajpheart.1992.263.3.h778.
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We evaluated the single and interactive effects of aging and exercise training on selected parameters of myocardial interstitium in both the left ventricle (LV) and LV papillary muscle of female Fischer 344 specific pathogen-free rats. Ten weeks of treadmill running resulted in significant LV hypertrophy as well as elevated plantaris muscle citrate synthase activity in both young adult (5-mo-old) and senescent (23-mo-old) trained animals (YT, young trained; OT, old trained) compared with age-matched sedentary controls (YC, young control; OC, old control). Proline and hydroxyproline pools were significantly higher (both P less than 0.05) in 23-mo-old vs. 5-mo-old papillary muscles. Degree of maturation (nonreducible cross-linking) of LV collagen was evaluated by measurement of hydroxylysylpyridinoline concentration ([HP]). In a comparison of YC with OC rats, ventricular [HP] increased approximately fivefold from 0.059 +/- 0.007 to 0.285 +/- 0.018 (SE) mol HP/mol collagen (P less than 0.001). Whereas training had no effect on ventricular [HP] in young adult rats, it significantly reduced LV collagen cross-linking in OT rats (0.131 +/- 0.027) so that HP values in this group were less than one-half of those observed in OC rats. Because both collagen concentration and degree of cross-linking are thought to affect muscle stiffness characteristics, we conclude that the observed changes should be considered in any explanation for aging- and training-induced alterations in LV and papillary muscle contractile indexes.
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Vieira, F., J. Kang, L. Ferreira und S. Mizuno. „Hydrostatic pressure mimicking diurnal spinal movements maintains anabolic turnover in bovine nucleus pulposus cells in vitro“. European Cells and Materials 42 (07.10.2021): 246–63. http://dx.doi.org/10.22203/ecm.v042a18.
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Treatment strategies for progressive intervertebral-disc degeneration often alleviate pain and other symptoms. With the goal of developing strategies to promote the regeneration of the nucleus pulposus (NP), the present study tried to identify the biological effects of hydrostatic (HP) and osmotic pressures on NP cells. The study hypothesis was that a repetitive regimen of cyclic HP followed by constant HP in high-osmolality medium would increase anabolic molecules in NP cells. Bovine NP cells/clusters were enclosed within semi-permeable membrane pouches and incubated under a regimen of cyclic HP for 2 d followed by constant HP for 1 d, repeated 6 times over 18 d. NP cells showed a significantly increased expression of anabolic genes over time: aggrecan, chondroitin sulfate N-acetylgalactosaminyltransferase 1, hyaluronan synthase 2, collagen type 2 (p < 0.05). In addition, the expression of catabolic or degenerative genes (matrix metalloproteinase 13, collagen type 1) and cellular characteristic genes (proliferating cell nucleic antigen, E-cadherin) was suppressed. The amount of sulfated glycosaminoglycan increased significantly at day 18 compared to day 3 (p < 0.01). Immunostaining revealed deposition of extracellular-matrix molecules and localization of other specific molecules corresponding to their genetic expression. An improved understanding of how cells respond to physicochemical stresses will help to better treat the degenerating disc using either cell- or gene-based therapies as well as other potential matrix-enhancing therapies. Efforts to apply these tissue-engineering and regenerative-medicine strategies will need to consider these important physicochemical stresses that may have a major impact on the survivability of such treatments.
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Abuduli, Maerjianghan, Hirokazu Ohminami, Tamaki Otani, Hitoshi Kubo, Haruka Ueda, Yoshichika Kawai, Masashi Masuda et al. „Effects of dietary phosphate on glucose and lipid metabolism“. American Journal of Physiology-Endocrinology and Metabolism 310, Nr. 7 (01.04.2016): E526—E538. http://dx.doi.org/10.1152/ajpendo.00234.2015.
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Recent epidemiological and animal studies have suggested that excess intake of phosphate (Pi) is a risk factor for the progression of chronic kidney disease and its cardiovascular complications. However, little is known about the impact of dietary high Pi intake on the development of metabolic disorders such as obesity and type 2 diabetes. In this study, we investigated the effects of dietary Pi on glucose and lipid metabolism in healthy rats. Male 8-wk-old Sprague-Dawley rats were divided into three groups and given experimental diets containing varying amounts of Pi, i.e., 0.2 [low Pi (LP)], 0.6 [control Pi (CP)], and 1.2% [high Pi (HP)]. After 4 wk, the HP group showed lower visceral fat accumulation compared with other groups, accompanied by a low respiratory exchange ratio (V̇co2/V̇o2) without alteration of locomotive activity. The HP group had lower levels of plasma insulin and nonesterified fatty acids. In addition, the HP group also showed suppressed expression of hepatic lipogenic genes, including sterol regulatory element-binding protein-1c, fatty acid synthase, and acetyl-CoA carboxylase, whereas there was no difference in hepatic fat oxidation among the groups. On the other hand, uncoupling protein (UCP) 1 and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) expression were significantly increased in the brown adipose tissue (BAT) of the HP group. Our data demonstrated that a high-Pi diet can negatively regulate lipid synthesis in the liver and increase mRNA expression related to lipid oxidation and UCP1 in BAT, thereby preventing visceral fat accumulation. Thus, dietary Pi is a novel metabolic regulator.
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Daniel, Andrea R., Chang-Lung Lee, Patrick Oh, Lixia Luo, Yan Ma und David G. Kirsch. „Inhibiting Glycogen Synthase Kinase-3 Mitigates the Hematopoietic Acute Radiation Syndrome in a Sex- and Strain-dependent Manner in Mice“. Health Physics 119, Nr. 3 (17.03.2020): 315–21. http://dx.doi.org/10.1097/hp.0000000000001243.
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Gallardo, M., I. Sanchez-Calle, PMD Rueda und AJ Matilla. „Alleviation of Thermoinhibition in Chickpea Seeds by Putrescine Involves the Ethylene Pathway“. Functional Plant Biology 23, Nr. 4 (1996): 479. http://dx.doi.org/10.1071/pp9960479.
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Germination of chickpea (Cicer arietinum L.) was inhibited by supraoptimal temperatures of 30 or 35�C, but the inhibition was alleviated by a relatively low concentration (1 mM) of putrescine (Put). This allevation may be due to (a) stimulation of the 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase activities; (b) increased levels of ACC and decreased levels of 1-(malonylamino)cyclopropane-1-carboxylic acid (MACC); or (c) strongly increased ethylene production. Put at 10 mM did not alleviate thermoinhibition, although, as with Put at 1 mM, it did inhibit adenosyl-methionine (AdoMet) decarboxylase. Alleviation conditions resulted in: (a) an induced accumulation of free Put (S) and Put conjugated to substances of low (HS) and high (HP) molecular weight; (b) a decrease in spermidine (Spd) and spermine (Spm) (S and HP); and (c) no alteration in the levels of Spd and Spm (HS) with respect to the absence of Put (1 mM) at 30�C. In the presence of Put (10 mM), increased accumulation of Put (S, HS and HP) was detected, but with a sharp decrease of Spd and Spm (S and HS).
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Skouloubris, Stéphane, Kamel Djaout, Isabelle Lamarre, Jean-Christophe Lambry, Karine Anger, Julien Briffotaux, Ursula Liebl, Hilde de Reuse und Hannu Myllykallio. „Targeting of Helicobacter pylori thymidylate synthase ThyX by non-mitotoxic hydroxy-naphthoquinones“. Open Biology 5, Nr. 6 (Juni 2015): 150015. http://dx.doi.org/10.1098/rsob.150015.
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ThyX is an essential thymidylate synthase that is mechanistically and structurally unrelated to the functionally analogous human enzyme, thus providing means for selective inhibition of bacterial growth. To identify novel compounds with anti-bacterial activity against the human pathogenic bacterium Helicobacter pylori , based on our earlier biochemical and structural analyses, we designed a series of eighteen 2-hydroxy-1,4-naphthoquinones (2-OH-1,4-NQs) that target Hp ThyX. Our lead-like molecules markedly inhibited the NADPH oxidation and 2′-deoxythymidine-5′-monophosphate-forming activities of Hp ThyX enzyme in vitro , with inhibitory constants in the low nanomolar range. The identification of non-cytotoxic and non-mitotoxic 2-OH-1,4-NQ inhibitors permitted testing their in vivo efficacy in a mouse model for H. pylori infections. Despite the widely assumed toxicity of naphthoquinones (NQs), we identified tight-binding ThyX inhibitors that were tolerated in mice and can be associated with a modest effect in reducing the number of colonizing bacteria. Our results thus provide proof-of-concept that targeting ThyX enzymes is a highly feasible strategy for the development of therapies against H. pylori and a high number of other ThyX-dependent pathogenic bacteria. We also demonstrate that chemical reactivity of NQs does not prevent their exploitation as anti-microbial compounds, particularly when mitotoxicity screening is used to prioritize these compounds for further experimentation.
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Jacobson, Azita, Changdong Yan, Qun Gao, Tibisay Rincon-Skinner, Aracelie Rivera, John Edwards, An Huang, Gabor Kaley und Dong Sun. „Aging enhances pressure-induced arterial superoxide formation“. American Journal of Physiology-Heart and Circulatory Physiology 293, Nr. 3 (September 2007): H1344—H1350. http://dx.doi.org/10.1152/ajpheart.00413.2007.
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The purpose of this study was to investigate the mechanisms that regulate superoxide (O2•−) production as a function of an acute elevation of intravascular pressure and age. Mesenteric arteries isolated from young (6 mo) and aged (24 mo) male Fischer 344 rats were used. O2•− production in vessels in response to 80 (normal pressure, NP) and 180 (high pressure, HP) mmHg was determined by the superoxide dismutase-inhibitable nitroblue tetrazolium (NBT) reduction assay. In vessels exposed to NP, O2•− production was significantly higher in aged than in young vessels (32.7 ± 7.0 vs. 15.4 ± 2.4 nmol·mg−1·30 min−1). HP enhanced O2•− production in vessels of both groups, but the enhancement was significantly greater in aged than in young vessels (63.4 ± 6.7 vs. 32.7 ± 4.3 nmol·mg−1·30 min−1). Apocynin (100 μmol/l) attenuated HP-induced increases in O2•− production in both groups, whereas allopurinol (100 μmol/l) and Nω-nitro-l-arginine methyl ester (100 μmol/l) inhibited the response only in aged vessels. Confocal microscopy showed increases in O2•− in response to HP in endothelial and smooth muscle layers of both groups, with much greater fluorescent staining in aged than in young rats and in the endothelium than in smooth muscle cells. No significant changes in NAD(P)H oxidase gene and protein expressions were observed in vessels of the two groups. Upregulation of protein expression of xanthine oxidase was detected in aged vessels. We conclude that NAD(P)H oxidase contributes importantly to HP-induced enhanced O2•− production in vessels of both young and aged rats, whereas xanthine oxidase and nitric oxide synthase-dependent O2•− production also contribute to the enhancement in mesenteric arteries of aged rats.
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Bueno-Pereira, Thaina Omia, Priscila Rezeck Nunes, Mariana Bertozzi Matheus, Ananda Lini Vieira da Rocha und Valeria Cristina Sandrim. „Nebivolol Increases Nitric Oxide Synthase via β3 Adrenergic Receptor in Endothelial Cells Following Exposure to Plasma from Preeclamptic Patients“. Cells 11, Nr. 5 (04.03.2022): 883. http://dx.doi.org/10.3390/cells11050883.
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Background: Low bioavailability of nitric oxide (NO) is related to the pathophysiology of preeclampsia (PE). In the present study, we investigated the effect of nebivolol (NEB), a β3-receptor agonist with vasodilator properties, on the NO synthesis in endothelial cells incubated with plasma from preeclamptic patients. Methods and results: Human umbilical vein endothelial cells (HUVECs) were incubated with plasma from healthy pregnant (HP) and PE women; NO quantification was assessed by a fluorescence compound. We found that endothelial cells incubated with plasma from women with PE show lower NO levels compared with the HP group (p < 0.0001). However, NEB treatment increases NO levels, partially, mediated by β3 adrenergic receptors (p < 0.0001) and through eNOS activation (p < 0.0001). Conclusions: Our results suggest that NEB acts in NO synthesis through eNOS activation and β3 adrenergic receptors in the endothelium. However, further studies will be needed to understand this molecule.
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Lamarque, D., J. Tankovic, C. Dutreuil, JC Delchier und BJR Whittle. „Induction of nitric oxide synthase by an extract of Helicobacter pylori (Hp) in rat duodenum“. Gastroenterology 108, Nr. 4 (April 1995): A143. http://dx.doi.org/10.1016/0016-5085(95)23234-6.
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Xudong, Gu, Zhang Fengju, Wang Teng, Xie Xiaowei, Jia Xiaohui und Xu Xing. „Effects of nitrogen and phosphorus addition on growth and leaf nitrogen metabolism of alfalfa in alkaline soil in Yinchuan Plain of Hetao Basin“. PeerJ 10 (13.04.2022): e13261. http://dx.doi.org/10.7717/peerj.13261.
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Alkaline soil is widely distributed in China. Its rational utilization is an effective measure to solve land shortage and improve the environment. Alfalfa is characterized by strong salt and alkali tolerance and high yield and protein content. Nitrogen (N) and phosphorus (P) are the main nutrients for plant growth, and N metabolism is one of the primary forms of plant metabolism, which plays a vital role in quality and yield formation. The exploration of the effect of N and P on N metabolism and alfalfa growth will provide a theoretical basis for scientific fertilization for alfalfa in the alkaline soil of the Yinchuan Plain of the Hetao Basin. Therefore, a 2-year experiment of N and P addition was conducted. Six treatments were set up with a randomized block design, including without N (WN), medium N (MN), high N (HN), without P (WP), medium P (MP), and high P (HP). It was found that the MN and MP treatments increased plant height, stem diameter, stem/leaf, dry/fresh, and dry matter of alfalfa. The HN and HP treatments inhibited alfalfa biomass formation. The MN and MP treatments increased key products and enzymes of leaf N metabolism of alfalfa and promoted activities of leaf nitrate reductase (NR), glutamine synthase (GS), glutamate synthase (GOGAT), glutamic-oxalacetic transaminase (GOT), and glutamic-pyruvate transaminase (GPT), and inhibited activities of leaf protease of alfalfa. The MN and MP treatments increased contents of leaf N, P, ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), total chlorophyll, and protein and reduced leaf chlorophyll a/b and amino acid, results after HN and HP treatments were opposite. The correlation among leaf P, N, NO3−-N, amino acid, and protein reached significant levels (P < 0.01). It is suggested that MN and MP treatments can improve the yield and quality of alfalfa by increasing key products and enzymes of N metabolism and can be adopted to promote alfalfa production in the alkaline soil of the Yinchuan Plain of the Hetao Basin.
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Brenndörfer, Maria, Hans Albert Brune, Tony Debaerdemaeker und Reinhard Hemmer. „Synthesen, Kristall- und Molekülstruktur ionischer Nickel-Komplexe mit Phosphanen im kationischen und anionischen Komplex-Teil / Syntheses, Crystal and Molecular Structure of Ionic Nickel Complexes with Phosphanes in the Cationic and Anionic Part“. Zeitschrift für Naturforschung B 40, Nr. 3 (01.03.1985): 357–62. http://dx.doi.org/10.1515/znb-1985-0308.
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The syntheses of five new nickel-II-complexes of the type [HPR′3][R3PNiCl3] (R,R′ = C6H5, n-C4H9, C6H11 , C5H9 and R = C6H5, R′ = C6H11) are described.The structure of the compound [HP(C6H11)3][(C6H5)3PNiCl3] was determined by X-ray analysis. The crystals are monoclinic; space group P21/n with the lattice parameters a = 18.180(5), b = 18.842(4), c = 11.173(3) Å and β = 107.12(6)°; Z = 4.
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Adamia, Sophia, Amanda Reichert, Anirban Ghosh, Jennifer Hodges, Patrick Pilarski, Steven Treon, Michael J. Mant, Tony Reiman, Andrew R. Belch und Linda M. Pilarski. „Germline and Somatic Mutations in the Hyaluronan Synthase–1 (HAS1) Gene May Contribute to Oncogenesis in Multiple Myeloma (MM) and Waldenstrom’s Macroglobulinemia (WM).“ Blood 110, Nr. 11 (16.11.2007): 2488. http://dx.doi.org/10.1182/blood.v110.11.2488.2488.
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Abstract In MM and WM, we identified aberrant HAS1 splice variants that were absent from normal donors (HD) and B-CLL. Here we sequenced multiple subclones from multiple cell subsets to show that aberrant HAS1 splicing results from cryptic splice sites activation. Aberrant splicing defects are the consequences of genetic variations (GVs) detected in the sequence of classical splicing elements as well as within exons and introns. To investigate HAS1 splicing in MM and WM patients, we sequenced the HAS1 gene segments involved in abnormal splicing events. HAS1 from buccal epithelial cells (BEC) represented the host genotype, and hematopoietic progenitors (HP), T, B and plasma cells (PC) as the normal and malignant components of the hematopoietic lineage in MM/WM. 197 GV were found in 16 MM or WM patients, but none in 9B-CLL, MGUS or HD. We found 60 germline (defined as present in BEC and hematopoietic cells) and 137 somatic GV (defined as GV found in HP, T, B and/or PC, but absent from BEC). These somatic GV include 97 tumor-specific GV found in MM and/or WM B and PC and 40 hematopoietic origin GV identified in HP, T, B and PC, but not in BEC. Some GV were recurrent, detected in more than one patient. Recurrent GV (24 in MM and 22 in WM) included both germline and somatic GVs, 6 tumor-specific, 6 hematopoietic and 14 germline origin GV, as well as 20 NCBI-SNPs. The distribution of GV indicated that some of the recurrent germline and somatic GV are restricted to MM, some are restricted to WM and some are shared by both MM and WM. None were found in B-CLL, MGUS or HD. The patterns of germline GV observed in MM and WM suggests that MM and WM patients, but not B-CLL, inherit recurrent germline GV that are necessary but not sufficient for progression to malignancy. Acquisition of recurrent, somatic HAS1 GV in HP further increases the risk of developing MM or WM. Transformation may become inevitable when tumor-specific recurrent GV are acquired. Interestingly, we detected increased homozygosity for the mutated allele of some germline GV in all cell types (PC, B, T, HPs and BECs) from MM and/or WM patients. These GV were detected in 75-90% of subclones analyzed. Mutational analysis of minigene constructs demonstrated a distribution of GV as clusters in the vicinity of HAS1splicing elements, allowing us to classify them as “splicing mutations”. This is supported by an in vitro splicing assay, which confirmed that a combination of germline and somatic GVs leads to aberrant HAS1 splicing (see abstract by Kriangkum et al., ASH 2007). Our study demonstrates that the impact of inherited and acquired GV on HAS1 gene splicing is manifested only in the context of accompanying tumor-specific HAS1 GV, that in combination give rise to the clinically significant aberrant splicing of HAS1. It also indicates that MM and WM are closely related at the genomic level, with the same recurrent somatic mutations independently arising in both diseases. Accumulation of somatically acquired HAS1 mutations in HP, in the context of inherited predispositions to MM and WM may represent a very early stage of pre-malignant development. Similar to leukemias, initiation events that contribute to MM and WM pathogenesis may arise from mutations which first accumulate during the non-malignant or pre-malignant stages of hematopoietic differentiation in progenitor cells.
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Kaihara, Julyane N. S., Caroline K. Minami, Maria T. S. Peraçoli, Mariana Romão-Veiga, Vanessa R. Ribeiro-Vasques, José C. Peraçoli, Ana C. T. Palei et al. „Plasma eNOS Concentration in Healthy Pregnancy and in Hypertensive Disorders of Pregnancy: Evidence of Reduced Concentrations in Pre-Eclampsia from Two Independent Studies“. Diseases 11, Nr. 4 (01.11.2023): 155. http://dx.doi.org/10.3390/diseases11040155.
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Hypertensive disorders of pregnancy (HDP), comprising gestational hypertension (GH) and pre-eclampsia (PE), are leading causes of maternal and perinatal morbidity and mortality. Both GH and PE are characterized by new-onset hypertension, but PE additionally includes proteinuria and/or end-organ damage. Impaired nitric oxide (NO) bioavailability may lead to endothelial dysfunction in GH and PE, and the primary source of vascular NO is endothelial NO synthase (eNOS). However, no previous study has investigated plasma eNOS concentrations in patients with GH and PE. In this study, we compared plasma eNOS concentrations in healthy pregnancies and HDP in two independent cohorts. The primary study included 417 subjects, with 43 non-pregnant (NP) and 156 healthy pregnant (HP) women and 122 patients with GH and 96 with PE. The replication study included 85 pregnant women (41 healthy and 44 pre-eclamptic). Plasma concentrations of eNOS were measured using a commercial ELISA kit provided by R&D Systems, and plasma nitrite concentrations were assessed using two ozone-based chemiluminescence assays. Correlations between plasma eNOS concentrations and plasma nitrite concentrations, as well as clinical and biochemical parameters, were evaluated by either Spearman’s or Pearson’s tests. In the primary study, NP women and HDP had significantly lower plasma eNOS concentrations compared to HP; concentrations were even lower in PE compared to GH. Plasma eNOS concentrations were reduced but not significant in early-onset PE, PE with severe features, preterm birth, and intrauterine growth restriction. No correlation was observed between plasma eNOS and nitrite levels. In HDP, there was a significant positive correlation between levels of eNOS and hemoglobin (r = 0.1496, p = 0.0336) as well as newborn weight (r = 0.1487, p = 0.0316). Conversely, a negative correlation between eNOS levels and proteinuria was observed (r = −0.2167, p = 0.0179). The replication study confirmed significantly reduced plasma concentrations of eNOS in PE compared to HP. Our findings provide evidence of reduced plasma eNOS concentrations in HDP; they were particularly lower in PE compared to GH and HP in two independent studies.
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Minami, N., Y. Imai, J. Hashimoto und K. Abe. „The role of nitric oxide in the baroreceptor-cardiac reflex in conscious Wistar rats“. American Journal of Physiology-Heart and Circulatory Physiology 269, Nr. 3 (01.09.1995): H851—H855. http://dx.doi.org/10.1152/ajpheart.1995.269.3.h851.
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The role of nitric oxide (NO) in baroreceptor-cardiac reflex function was examined using a NO synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME), in conscious Wistar rats. Mean arterial pressure (MAP) and heart period (HP) relationships were obtained by intravenous injection of graded doses of phenylephrine and sodium nitroprusside (SNP). The baroreflex function was compared before and after L-NAME (10 mg/kg iv), L-NAME (10 mg/kg iv) followed by exogenous NO supplied as SNP (10-20 micrograms.kg-1.min-1 iv), or SNP alone (20 micrograms.kg-1.min-1 iv). To find the effect of changing basal MAP on baroreflex function, the baroreflex function was also examined before and after phenylephrine (8 micrograms.kg-1.min-1 iv) or L-NAME followed by concomitant infusion of SNP and phenylephrine. L-NAME increased basal MAP as well as HP from 104 +/- 1 to 141 +/- 2 mmHg and from 168 +/- 3 to 237 +/- 7 ms, respectively. L-NAME shifted the sigmoid curve in the direction of higher MAP with a significant increase in the gain (gain: control 2.14 +/- 0.15 ms/mmHg, L-NAME 3.70 +/- 0.26 ms/mmHg, P < 0.001). L-NAME together with SNP infusion did not significantly affect the gain, basal MAP, or HP. Infusion of SNP alone shifted the sigmoid curve in the direction of lower MAP but had no significant effect on the gain. An infusion of phenylephrine or L-NAME with concomitant infusion of SNP and phenylephrine increased basal MAP similarly as L-NAME alone did but had no significant effect on the gain.(ABSTRACT TRUNCATED AT 250 WORDS)
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Ohnishi, Shiho, Ning Ma, Raynoo Thanan, Somchai Pinlaor, Olfat Hammam, Mariko Murata und Shosuke Kawanishi. „DNA Damage in Inflammation-Related Carcinogenesis and Cancer Stem Cells“. Oxidative Medicine and Cellular Longevity 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/387014.
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Infection and chronic inflammation have been recognized as important factors for carcinogenesis. Under inflammatory conditions, reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from inflammatory and epithelial cells and result in oxidative and nitrative DNA damage, such as 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) and 8-nitroguanine. The DNA damage can cause mutations and has been implicated in the initiation and/or promotion of inflammation-mediated carcinogenesis. It has been estimated that various infectious agents are carcinogenic to humans (IARC group 1), including parasites (Schistosoma haematobium(SH) andOpisthorchis viverrini(OV)), viruses (hepatitis C virus (HCV), human papillomavirus (HPV), and Epstein-Barr virus (EBV)), and bacteriumHelicobacter pylori(HP). SH, OV, HCV, HPV, EBV, and HP are important risk factors for bladder cancer, cholangiocarcinoma, hepatocellular carcinoma, cervical cancer, nasopharyngeal carcinoma, and gastric cancer, respectively. We demonstrated that 8-nitroguanine was strongly formed via inducible nitric oxide synthase (iNOS) expression at these cancer sites of patients. Moreover, 8-nitroguanine was formed in Oct3/4-positive stem cells in SH-associated bladder cancer tissues and in Oct3/4- and CD133-positive stem cells in OV-associated cholangiocarcinoma tissues. Therefore, it is considered that oxidative and nitrative DNA damage in stem cells may play a key role in inflammation-related carcinogenesis.
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Simon, Diána, Szabina Erdő-Bonyár, Katalin Böröcz, Noémi Balázs, Ahmed Badawy, Anna Bajnok, Jasper Nörenberg et al. „Altered Levels of Natural Autoantibodies against Heat Shock Proteins in Pregnant Women with Hashimoto’s Thyroiditis“. International Journal of Molecular Sciences 25, Nr. 3 (24.01.2024): 1423. http://dx.doi.org/10.3390/ijms25031423.
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The function of natural autoantibodies (nAAbs) in maintaining immunological tolerance has been comprehensively explained; however, their function in pregnant patients dealing with autoimmune diseases has not been thoroughly investigated. As Hashimoto’s thyroiditis (HT) is the predominant organ-specific autoimmune condition of women of childbearing age, this study’s objective was to evaluate IgM and IgG nAAbs targeting mitochondrial citrate synthase (CS) and heat shock proteins (Hsp60 and Hsp70) in women diagnosed with HT who were pregnant (HTP). Serum samples collected from HTP and healthy pregnant (HP) women in the first and third trimesters were tested using in-house-developed enzyme-linked immunosorbent assays (ELISAs). Our findings indicate the stability of nAAbs against CS and Hsps throughout the pregnancies of both healthy women and those with HT. However, during both trimesters, HTP patients displayed elevated levels of IgM isotype nAAbs against Hsp60 and Hsp70 compared to HP women, suggesting a regulatory role of IgM nAAbs during the pregnancies of patients with HT. Nonetheless, levels of IgG isotype nAAbs against Hsps were lower solely in the third trimester among HTP patients, resulting in a higher IgM/IgG ratio, which indicates their importance in alterations of the nAAb network during pregnancy in patients with HT.
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Lindenberg, Frank, Evamarie Hey-Hawkins und Gerhard Baum. „Aminolyse von Cp2ZrCl{P(SiMe3)2} - Synthese und Molekülstruktur von Cp2ZrCl(NHPh) / Aminolysis of Cp2ZrCl{P(SiMe3)2} - Synthesis and Molecular Structure of Cp2ZrCl(NHPh)“. Zeitschrift für Naturforschung B 50, Nr. 9 (01.09.1995): 1359–61. http://dx.doi.org/10.1515/znb-1995-0911.
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AbstractThe reaction of Cp2ZrCl{P(SiMe3)2} with aniline yields the terminal zirconocene phenylamido complex Cp2ZrCl(NHPh) (1) and HP(SiMe3)2. 1 was characterized spectroscopically (n.m.r., i.r.) and by X-ray structure determination (monoclinic space group P2 {ln, a - 6.589(2), b = 19.978(3), c = 13.512(2) Å , β = 101.09(2)° (at 200 K)). The NHPh group is planar with Zr -N 2116(10) Å.
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Zhang, Jingying, Changhai Sui, Yanli Wang, Shuying Liu, Huimin Liu, Zhengren Zhang und Hongzhang Liu. „Transcriptome-Wide Analysis Reveals Key DEGs in Flower Color Regulation of Hosta plantaginea (Lam.) Aschers“. Genes 11, Nr. 1 (26.12.2019): 31. http://dx.doi.org/10.3390/genes11010031.
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Background: Hosta plantaginea (Lam.) Aschers (HPA), a species in the family Liliaceae, is an important landscaping plant and herbaceous ornamental flower. However, because the flower has only two colors, white and purple, color matching applications are extremely limited. To date, the mechanism underlying flower color regulation remains unclear. Methods: In this study, the transcriptomes of three cultivars—H. plantaginea (HP, white flower), H. Cathayana (HC, purple flower), and H. plantaginea ‘Summer Fragrance’ (HS, purple flower)—at three flowering stages (bud stage, initial stage, and late flowering stage) were sequenced with the Illumina HiSeq 2000 (San Diego, CA, USA). The RNA-Seq results were validated by qRT-PCR of eight differentially expressed genes (DEGs). Then, we further analyzed the relationship between anthocyanidin synthase (ANS), chalcone synthase (CHS), and P450 and the flower color regulation by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Eukaryotic Orthologous Groups (KOG) network and pathway enrichment analyses. The overexpression of CHS and ANS in transgenic tobacco petals was verified using qRT-PCR, and the petal colors associated with the overexpression lines were confirmed using absorbance values. Results: Over 434,349 transcripts were isolated, and 302,832 unigenes were identified. Additionally, through transcriptome comparisons, 2098, 722, and 606 DEGs between the different stages were found for HP, HC, and HS, respectively. Furthermore, GO and KEGG pathway analyses showed that 84 color-related DEGs were enriched in 22 pathways. In particular, the flavonoid biosynthetic pathway, regulated by CHS, ANS, and the cytochrome P450-type monooxygenase gene, was upregulated in both purple flower varieties in the late flowering stage. In contrast, this gene was hardly expressed in the white flower variety, which was verified in the CHS and ANS overexpression transgenic tobacco petals. Conclusions: The results suggest that CHS, ANS, and the cytochrome P450s-regulated flavonoid biosynthetic pathway might play key roles in the regulation of flower color in HPA. These insights into the mechanism of flower color regulation could be used to guide artificial breeding of polychrome varieties of ornamental flowers.
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Deng, Guoliang, Zhiqing Jiang, Hui Lu, Naiyan Lu, Rongxiang Zhu, Chengkai Zhu, Peng Zhou und Xue Tang. „A Study on the Amelioration of Circadian Rhythm Disorders in Fat Mice Using High-Protein Diets“. Nutrients 15, Nr. 15 (04.08.2023): 3459. http://dx.doi.org/10.3390/nu15153459.
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This innovative study investigates the effects of high-protein diets (milk protein) on the circadian rhythm of hepatic lipid metabolism. We aimed to understand how high-protein interventions regulate biological clock genes, maintain lipid metabolism balance, and affect the circadian rhythm of antioxidant levels in vivo. We divided 120 SPF-class C57BL/6J mice into the control, high-fat/low-protein (HF-LP), and high-fat/high-protein (HF-HP) groups. Mice were sacrificed during active (2 a.m. and 8 a.m.) and rest periods (2 p.m. and 8 p.m.). In the HF-LP group, hepatic lipid anabolic enzymes were consistently expressed at high levels, while key lipolytic enzymes slowly increased after feeding with no significant diurnal differences. This led to an abnormal elevation in blood lipid levels, a slow increase in and low levels of superoxide dismutase, and a rapid increase in malondialdehyde levels, deviating from the diurnal trend observed in the control group. However, high-protein interventions in the HF-HP group restored lipid synthase activity and the expression of key catabolic enzymes, exhibiting a precise circadian rhythm. It also improved the lipid-metabolism rhythm, which was disrupted by the high-fat diet. Overall, high-protein interventions restored the expression of key enzymes involved in lipid metabolism, improving the lipid-metabolism rhythm, which was disrupted by the high-fat diet.
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Nocheva, Hristina, Nikolay S. Krastev, Dimo S. Krastev und Milka Mileva. „The Endogenous Cannabinoid and the Nitricoxidergic Systems in the Modulation of Stress Responses“. International Journal of Molecular Sciences 24, Nr. 3 (02.02.2023): 2886. http://dx.doi.org/10.3390/ijms24032886.
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The effects on stress-induced analgesia (SIA) from endogenous cannabinoid system (ECS) and nitric oxide (NO) interaction after 1 h of restraint stress were evaluated in male Wistar rats. The animals were subjected to 1 h of restraint and then injected with different combinations of cannabinoid receptor type 1 agonist anandamide (AEA) or antagonist AM251 along with an NO donor, NO precursor, or inhibitor of NO synthase. Nociception was evaluated using paw pressure (PP) or hot plate (HP) tests. AEA was administered immediately after the end of restraint-SIA (r-SIA). Administration of NO precursor reversed the pronociceptive effect of the CB1 agonist on r-SIA. Both the CB1 antagonist and the NOS inhibitor neutralized the pro-analgesic effect of L-arginine (L-arg). Administration of an NO donor, instead, increased r-SIA. Our experiments confirmed that the endogenous cannabinoid and the NO-ergic systems interact in the modulation of r-SIA. This interaction probably implies NO as a second messenger of the ECS.
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Masnoddin, Makdi, Clemente Michael Wong Vui Ling und Nur Athirah Yusof. „Functional Analysis of Conserved Hypothetical Proteins from the Antarctic Bacterium, Pedobacter cryoconitis Strain BG5 Reveals Protein Cold Adaptation and Thermal Tolerance Strategies“. Microorganisms 10, Nr. 8 (16.08.2022): 1654. http://dx.doi.org/10.3390/microorganisms10081654.
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Pedobacter cryoconitis BG5 is an obligate psychrophilic bacterium that was first isolated on King George Island, Antarctica. Over the last 50 years, the West Antarctic, including King George Island, has been one of the most rapidly warming places on Earth, hence making it an excellent area to measure the resilience of living species in warmed areas exposed to the constantly changing environment due to climate change. This bacterium encodes a genome of approximately 5694 protein-coding genes. However, 35% of the gene models for this species are found to be hypothetical proteins (HP). In this study, three conserved HP genes of P. cryoconitis, designated pcbg5hp1, pcbg5hp2 and pcbg5hp12, were cloned and the proteins were expressed, purified and their functions and structures were evaluated. Real-time quantitative PCR analysis revealed that these genes were expressed constitutively, suggesting a potentially important role where the expression of these genes under an almost constant demand might have some regulatory functions in thermal stress tolerance. Functional analysis showed that these proteins maintained their activities at low and moderate temperatures. Meanwhile, a low citrate synthase aggregation at 43 °C in the presence of PCBG5HP1 suggested the characteristics of chaperone activity. Furthermore, our comparative structural analysis demonstrated that the HPs exhibited cold-adapted traits, most notably increased flexibility in their 3D structures compared to their counterparts. Concurrently, the presence of a disulphide bridge and aromatic clusters was attributed to PCBG5HP1’s unusual protein stability and chaperone activity. Thus, this suggested that the HPs examined in this study acquired strategies to maintain a balance between molecular stability and structural flexibility. Conclusively, this study has established the structure–function relationships of the HPs produced by P. cryoconitis and provided crucial experimental evidence indicating their importance in thermal stress response.
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Jeazet Dongho Epse Mackon, Guibeline Charlie, Enerand Mackon, Yafei Ma, Yitong Zhao, Yuhang Yao, Xianggui Dai und Piqing Liu. „Development of the PARMS Markers of the Waxy Gene and Utilization in Discriminating Wild Accessions, and Cultivated Rice (Oryza sativa L.) with Different Eating and Cooking Quality“. Agronomy 12, Nr. 6 (28.05.2022): 1294. http://dx.doi.org/10.3390/agronomy12061294.
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Amylose content (AC) is the major indicator of rice eating and cooking quality (ECQ). Its synthesis in rice endosperm is mainly regulated by the protein, granule-bound starch synthase 1, which is encoded by the waxy gene (Os06g0133000, LOC_Os06g04200). The diversity of AC is largely attributable to the allelic variation at the Wx locus and the development of effective and accurate functional molecular markers to target rice variant alleles is crucial in the breeding strategy. In the present study, we developed six pairs of penta-primer amplification refractory mutation system (PARMS) markers to distinguish between Wxlv, Wxa, Wxin, Wxb, Wxmp, and Wxop,hp. These markers were successfully used to screen the genotype of large assets of genetic resources including 98 wild accessions, 55 cultivars, and 22 parental lines. Our results showed that Wxb in a low AC type was predominant in Guangxi cultivated rice as a result of cultural preference, while Wxlv in the wild accessions. Moreover, our findings surprisingly revealed the presence of Wxb in wild accession, which is a new outcome that may contribute to understanding the origin, selection and domestication processes of rice. These functional markers could be effectively used in marker-assisted breeding to improve selection efficiency of cultivars with desired AC in the early generation.
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Grobe, Joseph, Duc Le Van, Bettina Lüth und Marianne Hegemann. „Reaktive EC(p-p)π-Systeme, XXVI. Einfache Synthese für Methylenphosphane (Phosphaalkene) des Typs HPC(F)NR2 und das Phosphaalkin PC-N(iPr)2“. Chemische Berichte 123, Nr. 12 (Dezember 1990): 2317–20. http://dx.doi.org/10.1002/cber.19901231213.
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Cho, Sujin, Hookang Im, Ki-Young Lee, Jie Chen, Hae Ju Kang, Hye-Jin Yoon, Kyung Hoon Min, Kang Ro Lee, Hyun-Ju Park und Bong-Jin Lee. „Identification of novel scaffolds for potential anti- Helicobacter pylori agents based on the crystal structure of H. pylori 3-deoxy- d -manno-octulosonate 8-phosphate synthase ( Hp KDO8PS)“. European Journal of Medicinal Chemistry 108 (Januar 2016): 188–202. http://dx.doi.org/10.1016/j.ejmech.2015.11.036.
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Goncharova, Valentina, Shinji Iizuka, Yu Yamaguchi und Sophia Khaldoyanidi. „Hyaluronan Associated with the Bone Marrow Hematopoietic Microenvironment Is Required for the Recruitment and Retention of Hematopoietic Stem and Progenitor Cells In the Bone Marrow.“ Blood 116, Nr. 21 (19.11.2010): 2593. http://dx.doi.org/10.1182/blood.v116.21.2593.2593.
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Abstract Abstract 2593 The bone marrow microenvironment regulates a variety of hematopoietic stem cell (HSC) functions, including their recruitment into the marrow following transplantation. However, an insufficient understanding of the biology of the hematopoietic microenvironment reflects gaps in our knowledge of fundamental stem cell biology and remains an obstacle to an optimal therapeutic approach. While the involvement of hyaluronan (HA), one of the major components of the bone marrow ECM, in normal cell and tumor biology is generally appreciated, little is known of how HA contributes to the regulation of the hematopoietic microenvironment. In this study we investigated whether HA contributes to the recruitment of circulating HSCs into marrow. Stimulation of bone marrow cells with HA induced production of chemokines including SDF-1, MIP-1a, MIP-1b, IL-8, eotaxin, CXCL16, RANTES, LIX and MCP-1. HA-induced conditioned media containing these chemokines enhanced SDF-1-mediated HSC transmigration in vitro, whereas HA alone had no effect, suggesting that endogenous HA participates in the recruitment of HSC indirectly, via regulation of the production of chemokines. We next tested the relevance of this finding in vivo. Since HA synthase 2 knockout mice are embryonically lethal, we developed an alternative in vivo model that allows deprivation of HA. Mice were lethally irradiated to eliminate HSCs and to degrade endogenous HA, and injected with 4-MU, an HA synthase inhibitor, to prevent de novo synthesis of HA. Pre-treated mice were transplanted with HSCs, and after 24 hours the bone marrow was assayed by competitive reconstitution. This assay demonstrated that the number of HSCs which migrated into the marrow of mice pretreated with 4MU was significantly lower as compared to control. To further understand the role of endogenous HA in bone marrow microenvironment we used compound mutant mice in which Has1 and Has3, two genes encoding hyaluronan synthase, were knocked out (Has1-/-;Has3-/-). The number of hematopoietic progenitors (HPs) circulating in peripheral blood was significantly increased in the double knockout (dKO) mice as compared to the wild type (WT) mice. This increase in the number of circulating HP was further enhanced in triple Has knockout mice (Prx1-Cre;Has2flox/flox;Has1-/-;Has3-/-). This correlated with the higher number of hematopoietic progenitors in spleens of Has1-/-;Has3-/- double KO mice and Prx1-Cre;Has2flox/flox;Has1-/-;Has3-/- triple KO mice as compared to the WT mice. In summary, our data indicate that low levels of HA correlate with re-distribution of HSCs and HPs from bone marrow into peripheral blood and spleen. This suggests that HA associated with the hematopoietic microenvironment is important for recruitment and retention of HSCs and HPs, confirming that HA plays a critical regulatory role in the hematopoietic microenvironment. Disclosures: No relevant conflicts of interest to declare.
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Arnold, Adson Hagen, und Kathrin Castiglione. „Comparative Evaluation of the Asymmetric Synthesis of (S)-Norlaudanosoline in a Two-Step Biocatalytic Reaction with Whole Escherichia coli Cells in Batch and Continuous Flow Catalysis“. Catalysts 13, Nr. 10 (05.10.2023): 1347. http://dx.doi.org/10.3390/catal13101347.
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Opioids are important analgesics, and their pharmaceutical application is increasing worldwide. Many opioids are based on benzylisoquinoline alkaloids (BIA) and are still industrially produced from Papaver somniferum (opium poppy). (S)-norlaudanosoline ((S)-NLS) is a complex BIA and an advanced intermediate for diverse pharmaceuticals. The efficient synthesis of this scaffold could pave the way for a plant-independent synthesis platform. Although a promising biocatalytic route to (S)-NLS using norcoclaurine synthase (NCS) and ω-transaminase (TAm) has already been explored, the cost-effectiveness of this process still needs much improvement. Therefore, we investigated whether the synthesis could also be performed using whole cells to avoid the use of (partially) purified enzymes. With an optimized mixing ratio of TAm- and NCS-containing cells in batch biotransformations, 50 mM substrate was converted within 3 h with more than 90% yield and a high enantiomeric excess of the product (95%). To further increase the space–time yield, the cells were immobilized to enable their retainment in fixed-bed reactors. A comparison of glass beads, Diaion HP-2MG and alginate revealed that the addition of Diaion during bacterial growth led to the most active immobilisates. To facilitate sustained production of (S)-NLS, a fixed-bed setup was constructed based on lithographically printed columns from biocompatible PRO-BLK 10 plastic. The continuous production at two scales (5 mL and 50 mL columns) revealed insufficient system stability originating from biocatalyst leaching and inactivation. Thus, while the use of whole cells in batch biotransformations represents an immediate process improvement, the transfer to flow catalysis needs further optimization.
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Wolfsberger, Werner, Wolfgang Burkart, Sonja Bauer, Andreas Hampp, Justin Wolf und Helmut Werner. „Die Darstellung sterisch anspruchsvoller Phosphinoester und ihre Verwendung zur Synthese von Rhodium(I)-und Rhodium(III)-Komplexen [1] / The Preparation of Sterically Demanding Phosphinoesters and their Use for the Synthesis of Rhodium(I) and Rhodium (III) Complexes“. Zeitschrift für Naturforschung B 49, Nr. 12 (01.12.1994): 1659–73. http://dx.doi.org/10.1515/znb-1994-1209.
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Two routes for the preparation of sterically demanding phosphinoesters RR′P(CH2)nCO2Me (n=1,2 or 3) and RR′P(CH2)nCO2Et (n=1 or 2) have been developed: (1) reaction of trimethyl-silyl phosphines RR′PSiMe3 (R=R′=/Pr. rBu) with ω-chloroalkylesters, and (2) hydrophos- phination of secondary phosphines HP(R)Ph (R = Me, Et. Pr. iPr, iBu) with unsaturated carboxylic esters. From iPr2PCH2CO2Me (3) and iPr2PCH2CO2Et (4), a variety of rhodium(I) and rhodium(III) complexes, mainly with alkyne and vinylidene ligands, have been prepared. Compound [RhCl(C8H14)2]2 (19) reacts with four equiv. of 3 to give [RhCl(iPr2PCH2CO2Me)2] (20) which on further treatment with CO affords the carbonyl complex trans-[RhCl(CO)(iPr′>PCH2CO2Me)2] (21). The related ethylene derivative trans-[RhCl(C2H4)(iPr2PCH2CO2Me)2] (23) is obtained from [RhCl(C2H4)2]2 (22) and 3. Compound 20 reacts with H2 and HCl by oxidative addition to yield [RhHXCl(iPr2PCH2CO2Me)2] (24, 25) and with RC≡CR′ to give the alkyne complexes trans-[RhCl(RC≡CR′)(iPr2PCH2CO2Me)2] (26-28). The analogous compounds trans- RhCl(HC≡CR)(iPr2PCH2CO2Me)2] (29, 30), equally prepared from 20 and HC≡CR, both rearrange thermally and photochemically to produce the vinylidene isomers trans-[RhCl(=C=CHR)(iPr2PCH2CO2Me)2] (31, 32). In contrast, propyne reacts with 20 to give the allene complex trans-[RhCl(CH2=C=CH2)(iPr2PCH2CO2Me)2] (33). The synthesis of [RhCl(iPr2PCH2CO2Et)2] (34) and the corresponding alkyne and vinylidene adducts 35 and 36, obtained with HC≡CCO2Me as the substrate, is also described.
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Wang, Si-Yi, Yan Liu, Xiao-Mao Li, Adnan Mohammed Algradi, Hai Jiang, Yan-Ping Sun, Wei Guan, Juan Pan, Hai-Xue Kuang und Bing-You Yang. „Discovery of Active Ingredients Targeted TREM2 by SPR Biosensor-UPLC/MS Recognition System, and Investigating the Mechanism of Anti-Neuroinflammatory Activity on the Lignin-Amides from Datura metel Seeds“. Molecules 26, Nr. 19 (30.09.2021): 5946. http://dx.doi.org/10.3390/molecules26195946.
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As a new target protein for Alzheimer’s disease (AD), the triggering receptor expressed on myeloid Cells 2 (TREM2) was expressed on the surface of microglia, which was shown to regulate neuroinflammation, be associated with a variety of neuropathologic, and regarded as a potential indicator for monitoring AD. In this study, a novel recognition system based on surface plasmon resonance (SPR) for the TREM2 target spot was established coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-MS), in order to screen the active ingredients targeting TREM2 from Datura metel seeds. The results showed that four lignan-amides were discovered as candidate compounds by SPR biosensor-UPLC/MS recognition analysis. According to the guidance of the active ingredients discovered by the system, the lignin-amides from Datura metel seeds (LDS) were preliminarily identified as containing 27 lignan-amides, which were enriched compositions by the HP-20 of Datura metel seeds. Meanwhile, the anti-inflammatory activity of LDS was evaluated in BV2 microglia induced by LPS. Our experimental results demonstrated that LDS could reduce NO release in LPS-treated BV2 microglia cells and significantly reduce the expression of the proteins of inducible Nitric Oxide Synthase (iNOS), cyclooxygenase 2 (COX-2), microtubule-associated protein tau (Tau), and ionized calcium-binding adapter molecule 1 (IBA-1). Accordingly, LDS might increase the expression of TREM2/DNAX-activating protein of 12 kDa (DAP12) and suppress the Toll-like receptor SX4 (TLR4) pathway and Recombinant NLR Family, Pyrin Domain Containing Protein 3 (NLRP3)/cysteinyl aspartate specific proteinase-1 (Caspase-1) inflammasome expression by LDS in LPS-induced BV2 microglial cells. Then, the inhibitory release of inflammatory factors Interleukin 1 beta (IL-1β), Interleukin 6 (IL-6), and Tumor necrosis factor-alpha (TNFα) inflammatory cytokines were detected to inhibit neuroinflammatory responses. The present results propose that LDS has potential as an anti-neuroinflammatory agent against microglia-mediated neuroinflammatory disorders.
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Chang, Zhishuai, Wei Dai, Yufeng Mao, Zhenzhen Cui, Zhidan Zhang, Zhiwen Wang, Hongwu Ma und Tao Chen. „Enhanced 3-Hydroxypropionic Acid Production From Acetate via the Malonyl-CoA Pathway in Corynebacterium glutamicum“. Frontiers in Bioengineering and Biotechnology 9 (13.01.2022). http://dx.doi.org/10.3389/fbioe.2021.808258.
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Acetate is an economical and environmental-friendly alternative carbon source. Herein, the potential of harnessing Corynebacterium glutamicum as a host to produce 3-hydroxypropionic acid (3-HP) from acetate was explored. First, the expression level of malonyl-CoA reductase from Chloroflexus aurantiacus was optimized through several strategies, strain Cgz2/sod-N-C* showed an MCR enzyme activity of 63 nmol/mg/min and a 3-HP titer of 0.66 g/L in flasks. Next, the expression of citrate synthase in Cgz2/sod-N-C* was weakened to reduce the acetyl-CoA consumption in the TCA cycle, and the resulting strain Cgz12/sod-N-C* produced 2.39 g/L 3-HP from 9.32 g/L acetate. However, the subsequent deregulation of the expression of acetyl-CoA carboxylase genes in Cgz12/sod-N-C* resulted in an increased accumulation of intracellular fatty acids, instead of 3-HP. Accordingly, cerulenin was used to inhibit fatty acid synthesis in Cgz14/sod-N-C*, and its 3-HP titer was further increased to 4.26 g/L, with a yield of 0.50 g 3-HP/g-acetate. Finally, the engineered strain accumulated 17.1 g/L 3-HP in a bioreactor without cerulenin addition, representing the highest titer achieved using acetate as substrate. The results demonstrated that Corynebacterium glutamicum is a promising host for 3-HP production from acetate.
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Mohammed, Nourhan, Sahar A. Ahmed, Nagah I. Hegazy und Kamal Kashishy. „Ameliorative effects of hesperidin and N-acetylcysteine against formaldehyde-induced-hemato- and genotoxicity“. Toxicology Research, 24.08.2021. http://dx.doi.org/10.1093/toxres/tfab083.
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Abstract This study investigated the hemato- and genotoxic effects of formaldehyde (FA) and the possible mitigating role of hesperidin (HP) and N-acetylcysteine (NAC), each alone and in combination. Sixty-four adult male albino rats were divided into eight equal groups; the study was conducted for 8 weeks; Group I (negative control: received no medication), Group II (positive control: received distilled water), Group III (received HP 50 mg/kg/day), Group IV (received NAC 50 mg/kg/day), Group V (received FA 10 mg/kg/day), Group VI (FA + HP), Group VII (FA + NAC), and Group VIII (FA + HP + NAC). Groups VI, VII, VIII received the same previously mentioned doses and for the same duration. All treatments were given by intraperitoneal administration. At the end of the study, complete blood count, oxidative stress, histopathological changes, immunohistochemical staining of inducible nitric oxide synthase, and proliferating cell nuclear antigen and genotoxicity by comet assay in the bone marrow of treated rats were assessed. FA administration caused significant hematotoxicity represented by elevated white blood cell numbers and serum malondialdehyde levels and reduced red blood cell numbers, platelets, and serum superoxide dismutase values. Histologically, it induced an increase in fat cell numbers in bone marrow tissue with a widening of marrow spaces and decreased cellularity of hematopoietic cells, megakaryocytes, and granulocytes. FA exposure significantly decreased immunoreactivity for proliferating cell nuclear antigen, whereas the immunoreactivity for inducible nitric oxide synthase was increased. Genotoxicity, as measured by comet assay, revealed a significant increase in comet% and tail length in FA-treated group when compared with other groups. The cotreatment with HP and NAC revealed their ability to protect against hematological changes, oxidative damage, histopathological, and immunohistochemical changes, and genotoxicity induced by FA.
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Liang, Yan-Fei, Le-Tian Yan, Qiao Yue, Ji-Kui Zhao, Cai-Yun Luo, Feng Gao, Heng Li und Wen-Yun Gao. „Preparation of a whole cell catalyst overexpressing acetohydroxyacid synthase of Thermotoga maritima and its application in the syntheses of α-hydroxyketones“. Scientific Reports 10, Nr. 1 (21.09.2020). http://dx.doi.org/10.1038/s41598-020-72416-6.
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Abstract The large catalytic subunit of acetohydroxyacid synthase (AHAS, EC 2.2.1.6) of Thermotoga maritima (TmcAHAS) was prepared in this study. It possesses high specific activity and excellent stability. The protein and a whole cell catalyst overexpressing the protein were applied to the preparation of α-hydroxyketones including acetoin (AC), 3-hydroxy-2-pentanone (HP), and (R)-phenylacetylcarbinol (R-PAC). The results show that AC and HP could be produced in high yields (84% and 62%, respectively), while R-PAC could be synthesized in a high yield (about 78%) with an R/S ratio of 9:1. Therefore, TmcAHAS and the whole cell catalyst overexpressing the protein could be practically useful bio-catalysts in the preparation of α-hydroxyketones including AC, HP, and R-PAC. To the best of our knowledge, this is the first time that bacterial AHAS was used as a catalyst to prepare HP with a good yield, and also the first time that TmcAHAS was employed to synthesize AC and R-PAC.
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Xu, Shijie, Weibo Qiao, Zuanwen Wang, Xiaoying Fu, Zihe Liu und Shuobo Shi. „Exploiting a heterologous construction of the 3-hydroxypropionic acid carbon fixation pathway with mesaconate as an indicator in Saccharomyces cerevisiae“. Bioresources and Bioprocessing 10, Nr. 1 (24.05.2023). http://dx.doi.org/10.1186/s40643-023-00652-5.
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AbstractThe 3-Hydroxypropionic acid (3-HP) pathway is one of the six known natural carbon fixation pathways, in which the carbon species used is bicarbonate. It has been considered to be the most suitable pathway for aerobic CO2 fixation among the six natural carbon fixation pathways. Mesaconate is a high value-added derivative in the 3-HP pathway and can be used as a co-monomer to produce fire-retardant materials and hydrogels. In this study, we use mesaconate as a reporting compound to evaluate the construction and optimization of the sub-part of the 3-HP pathway in Saccharomyces cerevisiae. Combined with fine-tuning of the malonyl-CoA reductase (MCR-C and MCR-N) expression level and optimization of 3-Hydroxypropionyl-CoA synthase, the 3-HP sub-pathway was optimized using glucose or ethanol as the substrate, with the productions of mesaconate reaching 90.78 and 61.2 mg/L, respectively. Graphical Abstract
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Liu, Wei, Shan Yuan, Miaomiao Jin und Mo Xian. „Biocatalytic synthesis of 2-fluoro-3-hydroxypropionic acid“. Frontiers in Bioengineering and Biotechnology 10 (17.08.2022). http://dx.doi.org/10.3389/fbioe.2022.969012.
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Fluorine has become an important element for the design of synthetic molecules for use in medicine, agriculture, and materials. The introduction of fluorine atoms into organic compound molecules can often give these compounds new functions and make them have better performance. Despite the many advantages provided by fluorine for tuning key molecular properties, it is rarely found in natural metabolism. We seek to expand the molecular space available for discovery through the development of new biosynthetic strategies that cross synthetic with natural compounds. Towards this goal, 2-fluoro-3-hydroxypropionic acid (2-F-3-HP) was first synthesized using E. coli coexpressing methylmalonyl CoA synthase (MatBrp), methylmalonyl CoA reductase (MCR) and malonate transmembrane protein (MadLM). The concentration of 2-F-3-HP reached 50.0 mg/L by whole-cell transformation after 24 h. 2-F-3-HP can be used as the substrate to synthesize other fluorides, such as poly (2-fluoro-3-hydroxypropionic acid) (FP3HP). Being entirely biocatalytic, our procedure provides considerable advantages in terms of environmental and safety impacts over reported chemical methods.
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Gao, H. Y., J. S. Niu, W. Q. Liu, D. L. Zhang und S. P. Li. „Effect of wheat powdery mildew on grain nitrogen metabolism“. Journal of Agricultural Science, 21.04.2021, 1–11. http://dx.doi.org/10.1017/s0021859621000307.
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Abstract Glutamine synthetase (GS) and glutamate synthase (GOGAT) play a central role in plant nitrogen (N) metabolism. In order to study the effect of powdery mildew (Blumeria graminis f. sp. tritici, Bgt) on N metabolism, field experiments were carried out to evaluate GS and GOGAT activity, GS expression and grain protein content (GPC) in susceptible (Xi'nong 979) and resistant (Zhengmai 103) wheat cultivars under three treatments. The three treatments were no inoculation (CK), inoculated once with Bgt (MP) and inoculated nine times with Bgt (HP). For Xi'nong 979, the activities of GS and GOGAT in grains as well as GS activity in flag leaves increased at 10–15 days after anthesis (DAA), and decreased significantly at 15 or 20–30 DAA in HP and MP. However, GS activity in grains decreased from 20 DAA, which was later than that of flag leaves (15 DAA). At the same time, GS expression in grains was up-regulated at early stage, with GS1 at 10 DAA and GS2 at 15 DAA, followed by a continuous down-regulation. This result indicated that GS and GOGAT activity as well as GS expression were inhibited by powdery mildew, indicating that N metabolism in grains was inhibited at 20–30 DAA. The current study also found out that the yield of the susceptible cultivar decreased significantly, while its GPC increased obviously in HP. It was shown that the increase of GPC was not due to the enhancement of N metabolism, but due to the passive increase caused by yield reduction.
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Ma, Nana, Yusheng Liang, Fabiana F. Cardoso, Claudia Parys, Felipe C. Cardoso, Xiangzhen Shen und Juan J. Loor. „Insulin signaling and antioxidant proteins in adipose tissue explants from dairy cows challenged with hydrogen peroxide are altered by supplementation of arginine or arginine plus methionine“. Journal of Animal Science 100, Nr. 3 (06.02.2022). http://dx.doi.org/10.1093/jas/skac036.
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Abstract Arginine (Arg) and methionine (Met) can elicit anti-inflammatory and antioxidant effects in animals. Unlike Met, however, it is unknown if the supply of Arg can impact key aspects of adipose tissue (AT) function in dairy cows. Since Met and Arg metabolism are linked through the synthesis of polyamines, it is also possible that they have a complementary effect on aspects of AT function during a stress challenge. In this experiment, subcutaneous AT was harvested from four lactating multiparous Holstein cows (~27.0 kg milk per day, body condition score 3.38 ± 0.23) and used for incubations (4 h) with the following: control medium with an “ideal” profile of essential amino acids (IPAA; CTR; Lys:Met 2.9:1), IPAA plus 100 μM H2O2 (HP), H2O2 plus greater Arg supply (HPARG; Lys:Arg 1:1), or H2O2 plus greater Arg and methionine (Met) supply (HPARGMET; Lys:Met 2.5:1 and Lys:Arg 1:1). Western blotting was used to measure abundance of 18 protein targets associated with insulin and AA signaling, nutrient transport, inflammation, and antioxidant response. Reverse transcription polymerase chain reaction (RT-PCR) was used to assess effects on genes associated with Arg metabolism. Among the protein targets measured, although abundance of phosphorylated (p) AKT serine/threonine kinase (P = 0.05) and p-mechanistic target of rapamycin (P = 0.04) were lowest in HP explants, this effect was attenuated in HPARG and especially HPARGMET compared with CTR. Compared with HP, incubation with HPARG led to upregulation of the AA transporter solute carrier family 1 member 3 (L-glutamate transporter; P = 0.03), the reactive oxygen species detoxification-related enzyme glutathione S-transferase mu 1 (GSTM1; P = 0.03), and fatty acid synthase (P = 0.05). Those effects were accompanied by greater abundance of solute carrier family 2 member 4 (insulin-induced glucose transporter) in explants incubated with HPARG and also HPARGMET (P = 0.04). In addition, compared with other treatments, the peak response in abundance of the intracellular energy sensor 5ʹ-prime-AMP-activated protein kinase was detected with HPARGMET (P = 0.003). There was no effect of Arg or Arg plus Met on the mRNA abundance of genes associated with Arg metabolism (ARG1, NOS2, AMD1, SMS, and SRM). Overall, supplementation of Arg alone or with Met partially alleviated the negative effects induced by H2O2. More systematic studies need to be conducted to explore the function of Arg supply with or without Met on AT function.
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Li, Yong, Xiaoguang Wu, Yukang Mao, Chi Liu, Yiting Wu, Junzhe Tang, Kun Zhao und Peng Li. „Nitric Oxide Alleviated High Salt–Induced Cardiomyocyte Apoptosis and Autophagy Independent of Blood Pressure in Rats“. Frontiers in Cell and Developmental Biology 9 (29.04.2021). http://dx.doi.org/10.3389/fcell.2021.646575.
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The present study aimed to explore whether high-salt diet (HSD) could cause cardiac damage independent of blood pressure, and whether nitric oxide (NO) could alleviate high-salt–induced cardiomyocyte apoptosis and autophagy in rats. The rats received 8% HSD in vivo. H9C2 cells or primary neonatal rat cardiomyocytes (NRCM) were treated with sodium chloride (NaCl) in vitro. The levels of cleaved-caspase 3/caspase 3, cleaved-caspase 8/caspase 8, Bax/Bcl2, LC3 II/LC3 I, Beclin-1 and autophagy related 7 (ATG7) were increased in the heart of HSD rats with hypertension (HTN), and in hypertension-prone (HP) and hypertension-resistant (HR) rats. Middle and high doses (50 and 100 mM) of NaCl increased the level of cleaved-caspase 3/caspase 3, cleaved-caspase 8/caspase 8, Bax/Bcl2, LC3 II/LC3 I, Beclin-1, and ATG7 in H9C2 cells and NRCM. The endothelial NO synthase (eNOS) level was increased, but p-eNOS level was reduced in the heart of HSD rats and H9C2 cells treated with 100 mM NaCl. The level of NO was reduced in the serum and heart of HSD rats. NO donor sodium nitroprusside (SNP) reversed the increases of cleaved-caspase 3/caspase 3, cleaved-caspase 8/caspase 8, Bax/Bcl2 induced by NaCl (100 mM) in H9C2 cells and NRCM. SNP treatment attenuated the increases of cleaved-caspase 3/caspase 3, Bax/Bcl2, LC3 II/LC3 I, Beclin-1, and ATG7 in the heart, but had no effect on the blood pressure of HSD rats with HR. These results demonstrated that HSD enhanced cardiac damage independently of blood pressure. Exogenous NO supplementarity could alleviate the high salt–induced apoptosis and autophagy in cardiomyocytes.
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Silva, Grazielle F., Jaqueline S. Da Silva, Marina Silva, Tadeu Montagnoli, Allan K. Alencar, Bruna Rocha, Rosana Freitas, Carlos Fraga und Gisele Zapata-Sudo. „Abstract P2024: Novel Inhibitor Of P38 Mitogen-activated Protein Kinase Reverses Hypoxia-induced Pulmonary Hypertension In Rats“. Circulation Research 131, Suppl_1 (05.08.2022). http://dx.doi.org/10.1161/res.131.suppl_1.p2024.
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Pulmonary arterial hypertension (PAH) is a disease characterized by pulmonary vascular changes with subsequent right ventricular (RV) failure. This work investigated the hypothesis that a new p38-alpha mitogen-activated protein kinase (p38-alpha MAPK) inhibitor, named LASSBio-1824, could interfere on PH model in rats. Methods: HP was induced in male Wistar rats through the exposure to hypoxia (10% O2) during 3 weeks, in combination to i.p. injection of an antagonist of vascular endothelial growth factor receptor (SU5416; 20 mg/kg/weekly). Control rats were kept in normoxia. After 3 weeks, echocardiography images confirmed PH using the pulmonary artery (PA) outflow waveform. After disease onset, animals were randomly divided into three groups: control + vehicle (DMSO), PH + vehicle and PH + LASSBio-1824 (50 mg/kg/day), in which vehicle and LASSBio-1824 were orally administered (gavage) during two weeks. All experiments were in accordance with the Animal Care and Use Committee at Federal University of Rio de Janeiro (039/19). Results: Pulmonary acceleration time (PAT; ms) was reduced from 40.0 ± 2.1 (control) to 24.2 ± 1.8 in PH + vehicle group (p < 0.05) and restored to 36.8 ± 2.9 after treatment with LASSBio-1824 (p < 0.05). RV afterload was detected in PH group because of the increase of systolic pressure (mmHg) from 23.2 ± 1.5 (control) to 46.7 ± 2.8 (p < 0.05) which was reduced to 19.4 ± 2.7 with LASSBio1824 treatment. Medial wall thickness (%) of distal pulmonary arteries (PA, < 50 μm) was evaluated by using immunohistochemistry for alpha smooth muscle actin (alpha-SMA) which was increased from 64.0 ± 4.9 (control) to 80.8 ± 2.7 in PH group (p < 0.05), but it was significantly reduced to 55.0 ± 1.3 after treatment with the inhibitor (p < 0.05). Acetylcholine (ACh)-induced maximal relaxation (%) of PA from normal and PH rats, was reduced from 67.5 ± 1.6 to 51.9 ± 4.9 (p < 0.05). Therefore, the treatment with the p38 inhibitor normalized vascular reactivity to 73.0 ± 3.3 %. The immunohistochemistry for c-fos protein, a product of the p38 pathway related to cell proliferation, showed an increase of stained myocyte nuclei (%) in PH animals of 36.5 ± 1.5 when compared to normal group of 20.2 ± 4.2. The inhibitor significantly reduced ratio to 24.0 ± 2.3% (p < 0.05). PH increased the inflammatory condition because the expression of inducible nitric oxide synthase altered from 10.4 ± 1.9% (control) to 31.9 ± 2.2% and it was recovered by the inhibitor to 15.5 ± 2.2% (p < 0.05). In conclusion, the new p38-alpha MAPK inhibitor represents an important approach for the future treatment of PH, since it improves the underlying remodeling and inflammation processes.
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Jover, E., L. Matilla, M. Garaikoetxea, A. Fernandez-Celis, R. Sabada, A. Gainza, F. Jaisser und N. Lopez-Andres. „Regulation of neutrophil gelatinase-associated lipocalin in aortic valve stenosis“. European Heart Journal 42, Supplement_1 (01.10.2021). http://dx.doi.org/10.1093/eurheartj/ehab724.1557.
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Abstract Background Aortic valve (AV) stenosis is the commonest form of adult valvular heart disease (VHD) and affects 4.5% of the general population aged over 60 years. Owing to multifactorial and complex molecular events, the valve interstitial cell (VIC) undergoes myofibroblast and osteoblast differentiation. Neutrophil gelatinase-associated lipocalin (NGAL) is a pleiotropic glycoprotein belonging to the lipocalin family and it is expressed in a wide range of tissues and cell types. It is deregulated in several diseases with both detrimental and beneficial effects. NGAL mainly signals towards 24p3R. Purpose We aimed to confirm the expression of NGAL in human AV stenosis and its association with inflammation, oxidative stress, fibrosis/remodeling and calcification, and its regulation in calcifying VICs. Methods Surgical AV leftovers were harvested from patients undergoing elective surgical valve replacement with no kidney disease. Serum samples were collected within the 24h before the surgery. AV were histologically assessed by hematoxylin-eosin, Movat, Alizarin Red and Alcian blue/Sirius Red staining and immunohistochemistry. Western blotting, ELISA and zymography were used in molecular biology studies. VICs were challenged for 2, 4 and 8 days with hyperphosphate (2.6mM, HP) media ± rhNGAL for in vitro validation studies. Results NGAL was quantified in AVs and serum samples from 126 donors (57.4% men). Circulating NGAL was associated with circulating inflammation (Tumor Necrosis Factor-α, Interleukin (IL)-6 and ICAM-1) and oxidative stress (Myeloperoxidase (MPO) and 8OHdG) markers. Likewise, tissue NGAL was correlated with inflammation (IL-6, RANTES and Galectin-3), oxidative stress (MPO, Endothelial Nitric Oxide Synthase, Malondialdehyde (MDA) and Carboxy Methyl Lysine (CML)) and fibrosis (Collagen type I). Osteoblast markers, metalloproteinase (MMP)-9 expression or its activity were not associated with NGAL. NGAL was greater expressed in men than women (217.70±23.41 vs. 119.5±11.31, p=0.0098). In vitro, intracellular NGAL and 24p3R were strongly down-regulated in calcifying men-derived VICs (n=6) whereas secretion of NGAL was enhanced from day 4 (0.55±0.15, p=0.0283; 0.32±0.09 p<0.0001; 8.00±2.32, p=0.0053 fold changes, respectively). This may reflect reduced 24p3R-dependent signalling in osteoblast-like VICs. Such effects were overall negated in women-derived VICs (n=3). RhNGAL endowed calcifying VICs with increased necrosis (52KDa-cPARP1), apoptosis (cCaspase 3) and oxidative stress (CML, MDA, nitrotyrosine and pNF-kB) at day 8. Conclusions NGAL is associated with inflammation, oxidative stress and fibrosis in AV stenosis, and promotes pro-apoptotic and necrotic phenotypes in vitro. Our results suggest that NGAL signaling may drive sex-dependent differences clinically relevant to the VHD pathogenesis. The challenge is now to understand how NGAL signals in men/women-derived VICs. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III