Academic literature on the topic 'Internalization inhibitors'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Internalization inhibitors.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Internalization inhibitors"
1
DiCello, Jesse J., Pradeep Rajasekhar, Emily M. Eriksson, Ayame Saito, Arisbel B. Gondin, Nicholas A. Veldhuis, Meritxell Canals, Simona E. Carbone, and Daniel P. Poole. "Clathrin and GRK2/3 inhibitors block δ-opioid receptor internalization in myenteric neurons and inhibit neuromuscular transmission in the mouse colon." American Journal of Physiology-Gastrointestinal and Liver Physiology 317, no. 2 (August 1, 2019): G79—G89. http://dx.doi.org/10.1152/ajpgi.00085.2019.
Full textAbstract:
Endocytosis is a major mechanism through which cellular signaling by G protein-coupled receptors (GPCRs) is terminated. However, recent studies demonstrate that GPCRs are internalized in an active state and continue to signal from within endosomes, resulting in effects on cellular function that are distinct to those arising at the cell surface. Endocytosis inhibitors are commonly used to define the importance of GPCR internalization for physiological and pathophysiological processes. Here, we provide the first detailed examination of the effects of these inhibitors on neurogenic contractions of gastrointestinal smooth muscle, a key preliminary step to evaluate the importance of GPCR endocytosis for gut function. Inhibitors of clathrin-mediated endocytosis (Pitstop2, PS2) or G protein-coupled receptor kinase-2/3-dependent phosphorylation (Takeda compound 101, Cmpd101), significantly reduced GPCR internalization. However, they also attenuated cholinergic contractions through different mechanisms. PS2 abolished contractile responses by colonic muscle to SNC80 and morphine, which strongly and weakly internalize δ-opioid and μ-opioid receptors, respectively. PS2 did not affect the increased myogenic contractile activity following removal of an inhibitory neural influence (tetrodotoxin) but suppressed electrically evoked neurogenic contractions. Ca2+ signaling by myenteric neurons in response to exogenous ATP was unaffected by PS2, suggesting inhibitory actions on neurotransmitter release rather than neurotransmission. In contrast, Cmpd101 attenuated contractions to the cholinergic agonist carbachol, indicating direct effects on smooth muscle. We conclude that, although PS2 and Cmpd101 are effective blockers of GPCR endocytosis in enteric neurons, these inhibitors are unsuitable for the study of neurally mediated gut function due to their inhibitory effects on neuromuscular transmission and smooth muscle contractility. NEW & NOTEWORTHY Internalization of activated G protein-coupled receptors is a major determinant of the type and duration of subsequent downstream signaling events. Inhibitors of endocytosis effectively block opioid receptor internalization in enteric neurons. The clathrin-dependent endocytosis inhibitor Pitstop2 blocks effects of opioids on neurogenic contractions of the colon in an internalization-independent manner. These inhibitors also significantly impact cholinergic neuromuscular transmission. We conclude that these tools are unsuitable for examination of the contribution of neuronal G protein-coupled receptor endocytosis to gastrointestinal motility.
2
Bigby, M., P. Wang, J. F. Fierro, and M. S. Sy. "Phorbol myristate acetate-induced down-modulation of CD4 is dependent on calmodulin and intracellular calcium." Journal of Immunology 144, no. 8 (April 15, 1990): 3111–16. http://dx.doi.org/10.4049/jimmunol.144.8.3111.
Full textAbstract:
Abstract PMA causes rapid down-modulation of CD4 molecules on murine immature thymocytes, human PBL, and CD4-positive human tumor cell lines, but not on murine peripheral lymphocytes. The mechanisms of phorbol ester-induced down modulation of CD4 molecules, however, have not been elucidated. To determine how PMA down-modulates CD4 expression by T lymphocytes, we studied the ability of inhibitors of protein kinase C, calmodulin, actin, and tubulin to block PMA-induced modulation of CD4 in several murine and human cell types. We also tested the ability of intracellular and extracellular calcium chelators to block CD4 internalization. There was marked variability in the degree of PMA-induced down-modulation of CD4 among various cell types. The effects of PMA on CD4 expression were greater for murine thymocytes, for human PBL, and for the human lymphoblastic leukemia cell line, MOLT-3, than for any of the other cell types studied. The protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine, blocked phosphorylation but not internalization of CD4 molecules induced by PMA. Therefore, phosphorylation of CD4 molecules by protein kinase C is not required for the internalization of the molecules. Internalization was blocked by both inhibitors of calmodulin, N-(6-aminohexyl)-5-chloro-1-naphthalene-sulfonamide, and trifluoperazine. PMA-induced internalization of CD4 was blocked by Quin-2 AM, which chelates intracellular calcium. EGTA, which chelates extracellular calcium, did not block internalization. Inhibitors of actin or tubulin did not block internalization. These results suggest that PMA-induced modulation of CD4 can occur in the absence of phosphorylation of the CD4 molecules and is calmodulin and intracellular calcium dependent.
3
van Kerkhof, P., and G. J. Strous. "The ubiquitin-proteasome pathway regulates lysosomal degradation of the growth hormone receptor and its ligand." Biochemical Society Transactions 29, no. 4 (August 1, 2001): 488–93. http://dx.doi.org/10.1042/bst0290488.
Full textAbstract:
The growth hormone (GH) receptor (GHR) is a mammalian plasma membrane protein whose internalization is mediated by the ubiquitin-proteasome pathway. GH internalization and degradation are inhibited when cells are treated with proteasome inhibitors. Here we show that a GHR truncated at residue 369 can enter the cells in the presence of a proteasome inhibitor, but that the subsequent lysosomal degradation of GH is blocked. Lysosomal inhibitors prolong the half-life of both receptor and ligand. Experiments with antibodies against different receptor tail sections show that degradation of the GHR cytosolic domain precedes degradation of the extracellular GH-binding domain. A possible role for the ubiquitin-proteasome pathway in the degradation of the receptor and ligand is discussed.
4
Luton, F., M. Buferne, J. Davoust, A. M. Schmitt-Verhulst, and C. Boyer. "Evidence for protein tyrosine kinase involvement in ligand-induced TCR/CD3 internalization and surface redistribution." Journal of Immunology 153, no. 1 (July 1, 1994): 63–72. http://dx.doi.org/10.4049/jimmunol.153.1.63.
Full textAbstract:
Abstract Triggering of the TCR/CD3 complex can lead to its internalization and modulation from the cell surface. In the present study, we address the question of the dependence of internalization on protein tyrosine kinase (PTK) activation. With use of an activating anti-clonotypic (anti-Ti) mAb on a CTL clone, we have shown that the PTK inhibitors genistein and tyrphostin 25 delayed anti-Ti-induced internalization, but did not affect fluid phase protein uptake or transferrin receptor cycling. Confocal microscopy with use of fluorescent anti-Ti mAb revealed that the inhibition of TCR internalization corresponded to the induction of large patches that were localized in cell membrane areas depleted of polymerized actin, the formation of which was dependent on the combined action of the anti-Ti mAb and the PTK inhibitors. In contrast to the effect of these PTK inhibitors, depletion of Src-like PTKs by T cell pretreatment with herbimycin A led to an increased rate of anti-Ti-induced internalization. Internalization induced by the monovalent Fab fraction of anti-Ti mAb was similarly affected by the PTK inhibitors, although the extent of induced internalization was less by approximately one-half. An analysis of substrates phosphorylated in kinase assays on TCR/CD3 immunoprecipitates of the CTL, which were activated by anti-Ti mAb in both the absence and presence of genistein, identified protein bands in which phosphorylation or association with CD3 was inhibited in the presence of genistein. Thus, a genistein-sensitive PTK activity seems to control ligand-induced TCR/CD3 complex redistribution and internalization.
5
Chen, Yang, Shan Wang, Xinan Lu, Haoran Zhang, Yan Fu, and Yongzhang Luo. "Cholesterol sequestration by nystatin enhances the uptake and activity of endostatin in endothelium via regulating distinct endocytic pathways." Blood 117, no. 23 (June 9, 2011): 6392–403. http://dx.doi.org/10.1182/blood-2010-12-322867.
Full textAbstract:
Abstract Specific internalization of endostatin into endothelial cells has been proved to be important for its biologic functions. However, the mechanism of endostatin internalization still remains elusive. In this study, we report for the first time that both caveolae/lipid rafts and clathrin-coated pits are involved in endostatin internalization. Inhibition of either the caveolae pathway or the clathrin pathway with the use of chemical inhibitors, small interfering RNAs, or dominant-negative mutants alters endostatin internalization in vitro. Intriguingly, cholesterol sequestration by nystatin, a polyene antifungal drug, significantly enhances endostatin uptake by endothelial cells through switching endostatin internalization predominantly to the clathrin-mediated pathway. Nystatin-enhanced internalization of endostatin also increases its inhibitory effects on endothelial cell tube formation and migration. More importantly, combined treatment with nystatin and endostatin selectively enhances endostatin uptake and biodistribution in tumor blood vessels and tumor tissues but not in normal tissues of tumor-bearing mice, ultimately resulting in elevated antiangiogenic and antitumor efficacies of endostatin in vivo. Taken together, our data show a novel mechanism of endostatin internalization and support the potential application of enhancing the uptake and therapeutic efficacy of endostatin via regulating distinct endocytic pathways with cholesterol-sequestering agents.
6
Lazari, Maria de Fatima M., Xuebo Liu, Kazuto Nakamura, Jeffrey L. Benovic, and Mario Ascoli. "Role of G Protein-Coupled Receptor Kinases on the Agonist-Induced Phosphorylation and Internalization of the Follitropin Receptor." Molecular Endocrinology 13, no. 6 (June 1, 1999): 866–78. http://dx.doi.org/10.1210/mend.13.6.0289.
Full textAbstract:
Abstract The experiments presented herein were designed to identify members of the G protein-coupled receptor kinase (GRK) family that participate in the agonist-induced phosphorylation and internalization of the rat FSH receptor (rFSHR). Western blots of human kidney 293 cells (the cell line used in transfection experiments) and MSC-1 cells (a cell line derived from Sertoli cells that displays many of the differentiated functions of their normal counterparts) reveal the presence of GRK2 and GRK6 in both cell lines as well as GRK4 in MSC-1 cells. Cotransfection of 293 cells with the rFSHR and GRK2, GRK4α, or GRK6 resulted in an increase in the agonist-induced phosphorylation of the rFSHR. Cotransfections of the rFSHR with GRKs or arrestin-3 enhanced the agonist-induced internalization of the rFHSR, and combinations of GRKs and arrestin-3 were more effective than the individual components. To characterize the involvement of endogenous GRKs on phosphorylation and internalization, we inhibited endogenous GRK2 by overexpression of a kinase-deficient mutant of GRK2 or Gαt, a scavenger of Gβγ. We also inhibited endogenous GRK6 by overexpression of a kinase-deficient mutant of GKR6. All three constructs were effective inhibitors of phosphorylation, but only the kinase-deficient mutant of GRK2 and Gαt inhibited internalization. The inhibition of internalization induced by these two constructs was less pronounced than that induced by a dominant-negative mutant of the nonvisual arrrestins, however. The finding that inhibitors of GRK2 and GRK6 impair phosphorylation, but only the inhibitors of GRK2 impair internalization, suggests that different GRKs have differential effects on receptor internalization.
7
Almeida, Raul A., John R. Dunlap, and Stephen P. Oliver. "Binding of Host Factors Influences Internalization and Intracellular Trafficking ofStreptococcus uberisin Bovine Mammary Epithelial Cells." Veterinary Medicine International 2010 (2010): 1–8. http://dx.doi.org/10.4061/2010/319192.
Full textAbstract:
We showed that internalization ofStreptococcus uberisinto bovine mammary epithelial cells occurred through receptor- (RME) and caveolae-mediated endocytosis (CME). We reported also that treatment ofS. uberiswith host proteins including lactoferrin (LF) enhanced its internalization into host cells. Since the underlying mechanism(s) involved in such enhancement was unknown we investigated if preincubation ofS. uberiswith host proteins drives internalization of this pathogen into host cells through CME. Thus, experiments involving coculture of collagen-, fibronectin-, and LF-pretreatedS. uberiswith bovine mammary epithelial cells treated with RME and CME inhibitors were conducted. Results showed that internalization of host proteins-pretreatedS. uberisinto mammary epithelial cells treated with RME inhibitors was higher than that of untreated controls. These results suggest that pretreatment with selected host proteins commitsS. uberisto CME, thus avoiding intracellular bactericidal mechanisms and allowing its persistence into bovine mammary epithelial cells.
8
Van Hamme, Evelien, Hannah L. Dewerchin, Els Cornelissen, Bruno Verhasselt, and Hans J. Nauwynck. "Clathrin- and caveolae-independent entry of feline infectious peritonitis virus in monocytes depends on dynamin." Journal of General Virology 89, no. 9 (September 1, 2008): 2147–56. http://dx.doi.org/10.1099/vir.0.2008/001602-0.
Full textAbstract:
Feline infectious peritonitis virus (FIPV), a coronavirus that causes a lethal chronic disease in cats, enters feline monocytes via endocytosis. In this study, the pathway of internalization is characterized by evaluating the effect of chemical inhibitors and/or expression of dominant-negative (DN) proteins on the percentage of internalized virions per cell and infection. Further, co-localization studies were performed to determine the involvement of certain cellular internalization proteins. FIPV is not internalized through a clathrin-mediated pathway, as chlorpromazine, amantadine and DN eps15 did not influence virus uptake and FIPV did not co-localize with clathrin. The caveolae-mediated pathway could be excluded based on the inability of genistein and DN caveolin-1 to inhibit virus uptake and lack of co-localization between FIPV and caveolin-1. Dynamin inhibitory peptide and DN dynamin effectively inhibited virus internalization. The inhibitor strongly reduced uptake to 20.3±1.1 % of uptake in untreated cells. In the presence of DN dynamin, uptake was 58.7±3.9 % relative to uptake in untransduced cells. Internalization of FIPV was slightly reduced to 85.0±1.4 and 87.4±6.1 % of internalization in control cells by the sterol-binding drugs nystatin and methyl-β-cyclodextrin, respectively. Rho GTPases were inhibited by Clostridium difficile toxin B, but no effect was observed. These results were confirmed with infection studies showing that infection was not influenced by chlorpromazine, amantadine and genistein, but was significantly reduced by dynamin inhibition and nystatin. In conclusion, these results indicate that FIPV enters monocytes through a clathrin- and caveolae-independent pathway that strongly depends on dynamin and is slightly sensitive to cholesterol depletion.
9
Goretzki, L., and B. M. Mueller. "Receptor-mediated endocytosis of urokinase-type plasminogen activator is regulated by cAMP-dependent protein kinase." Journal of Cell Science 110, no. 12 (June 15, 1997): 1395–402. http://dx.doi.org/10.1242/jcs.110.12.1395.
Full textAbstract:
Internalization of the urokinase-type plasminogen activator (uPA) requires two receptors, the uPA receptor (uPAR) and the low density lipoprotein receptor-related protein (LRP)/alpha2-macroglobulin (alpha2M) receptor. Here, we address whether protein kinases are involved in the internalization of uPA by human melanoma cells. Initially, we found that the internalization of uPA was significantly inhibited by the serine/threonine protein kinase inhibitors staurosporine, K-252a and H-89, but not by the tyrosine kinase inhibitors, genistein and lavendustin A. Internalization of uPA was also inhibited by a pseudosubstrate peptide for cAMP-dependent protein kinase (PKA), but not by a pseudosubstrate peptide for protein kinase C. We confirmed a requirement for PKA-activity and implicated a specific isoform by using an antisense oligonucleotide against the regulatory subunit RI alpha of PKA which suppresses PKA-I activity. Exposure of cells to this oligonucleotide led to a specific, dose-dependent decrease in RI alpha protein and to a significant inhibition in the rate of uPA internalization. We further demonstrate that treatment of melanoma cells with either H-89 or PKA RI alpha antisense oligonucleotides also resulted in a decreased internalization of two other ligands of LRP, activated alpha2M and lactoferrin, indicating that PKA activity is associated with LRP. Finally, we demonstrate that PKA activity is also required for the internalization of transferrin, but not for the internalization of the epidermal growth factor or adenovirus 2, suggesting that in melanoma cells, PKA activity is not generally required for clathrin-mediated endocytosis, but is rather associated with specific internalization receptors.
10
Huang, Dianshuai, Qingjie Fan, Zhiyi Liu, Shuqin Zhang, Wei Huang, Hongrui Li, Chongyang Liang, and Fei Sun. "An Epitope on EGFR Loading Catastrophic Internalization Serve as a Novel Oncotarget for Hepatocellular Carcinoma Therapy." Cancers 12, no. 2 (February 16, 2020): 456. http://dx.doi.org/10.3390/cancers12020456.
Full textAbstract:
The precise role of Epidermal Growth Factor Receptor (EGFR) in Hepatocellular carcinoma (HCC) cells is unknown and EGFR inhibitors have not achieved positive clinical results. The rapid and drastic internalization of EGFR has been proved to successfully treat EGFR inhibitor-resistant patients in recent clinical trials. Here, the anti-tumor efficacy of a protein (rLZ-8) from Ganoderma lucidum was evaluated, it was demonstrated that rLZ-8 could bind to EGFR specifically, drastically enter into Hepatoma cells, abrogate endosomal recycling and induce HCC cell death. Surprisingly, we screened a monoclonal antibody which possesses competitive binding site with rLZ-8, it also trigger catastrophic EGFR internalization. This result suggests that it is necessary to investigate the interface of EGFR and rLZ-8 complex. An internalization related epitope (S222/K269) was identified on the dimerization arm of EGFR extracellular domain (ECD). These results suggest vulnerability of HCC cells to catastrophic EGFR internalization that can be targeted by a novel epitope and point to the possible exploitation in the design of anti-EGFR therapeutic biologics for HCC therapy.
Dissertations / Theses on the topic "Internalization inhibitors"
1
Qian, Yanrong. "Internalization of Extracellular ATP in Cancer Cells and Development of New Generations of Anticancer Glucose Transport Inhibitors." Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1416411921.
Full text
2
Alvear-Perez, Rodrigo. "Voies de signalisation activées lors de la stimulation du récepteur de l'apéline, responsables de l'effet hypotenseur de l'apéline." Electronic Thesis or Diss., Sorbonne Paris Cité, 2019. http://www.theses.fr/2019USPCB021.
Full textAbstract:
L'apéline est un neuropeptide vasoactif qui joue un rôle crucial dans le maintien de l'équilibre hydrique et des fonctions cardiovasculaires. Des études réalisées au laboratoire sur les effets de l'apéline-17 (K17F) et du fragment d'apéline K16P, correspondant à K17F delétée de la phénylalanine (Phe) à son extrémité C-terminale, ont montré que la présence de cette Phe est nécessaire pour que l'apéline puisse d'une part, induire l'internalisation du récepteur de l'apéline, et d'autre part, provoquer une baisse de la pression artérielle. Par la suite, nous avons identifié dans les cellules CHO, exprimant de façon stable le récepteur murin de l'apéline que l'internalisation du récepteur de l'apéline induite par K17F avait pour conséquence d'induire l'activation d'une seconde voie de signalisation indépendante de la protéine Gi et dépendante de la beta-arrestine, correspondant à la voie des MAP kinases (Mitogen Activator Protein Kinase), qui pourrait être impliquée dans l'effet hypotenseur de l'apéline. Mes travaux ont ensuite consisté à caractériser dans un modèle physiologique, les artérioles afférentes juxtamédullaires de rein de rat (AAJM), si la voie de signalisation médiée par la beta-arrestine était impliquée dans l'effet vasodilatateur de K17F. Sachant que l'AngII induit une vasoconstriction en augmentant la mobilisation de calcium intracellulaire ([Ca2+]i), nous avons montré en mesurant les variations de diamètre artériolaire et de [Ca2+]i, que lorsque la voie Gi est bloquée par la toxine de pertussis (PTX), l'effet vasorelaxant induit par K17F n'est pas modifié. Ces données suggèrent que l'effet vasorelaxant de K17F sur les AAJM précontractées par l'AngII est protéine Gi-indépendant. En présence de PTX et de différents inhibiteurs d'internalisation, l'effet vasorelaxant induit par K17F sur les AAJM pré-contractées par l'AngII est aboli. De plus, en présence de PTX et de ces inhibiteurs, lorsque l'on applique K17F sur la phase plateau de la réponse calcique induite par l'AngII, aucune diminution significative de la mobilisation du [Ca2+]i est observée. Ceci est en accord avec notre hypothèse, à savoir que l'effet vasorelaxant de K17F est protéine Gi-indépendant et beta-arrestine-dépendant. L'ApélineR constitue une cible thérapeutique potentielle dans le traitement de l'insuffisance cardiaque et des rétentions hydriques. Sachant que la demi-vie de l'apéline dans la circulation sanguine est de l'ordre de la minute, un autre volet de mon travail de thèse a été de développer des analogues de K17F métaboliquement stables par deux stratégies différentes. Premièrement, nous avons substitué chacun des résidus de l'apéline par son énantiomère de la série D ou par un acide aminé synthétique. Deuxièmement, nous avons ajouté une chaîne fluoroalkyle à l'extrémité N-terminale de K17F. Ces deux stratégies nous ont permis d'obtenir plusieurs composés dont les plus actifs sont le P92 et le LIT01-196 qui conservent des propriétés pharmacologiques identiques à celles de K17F et qui présentent une demi-vie plasmatique largement supérieure à celle du peptide endogène. Ces deux analogues se sont révélés actifs in vivo avec une capacité à diminuer la pression artérielle et à réduire la sécrétion de vasopressine dans le sang conduisant à une augmentation de la diurèse aqueuseApeline is a vasoactive neuropeptide which plays a crucial role in maintaining water balance and cardiovascular functions. Laboratory studies on the effects of Aperlin-17 (K17F) and the K16P apelin fragment, corresponding to K17F deletion from phenylalanine (Phe) at its C-terminal part have shown the presence of this Phe is necessary for apelin to induce internalization of the Apelin receptor. Also cause a decrease in blood pressure. Subsequently, in the CHO cells expressing stably the murine receptor of the Apelin that the internalization of the Apelin receptor induced by K17F resulted in the activation of a second signaling pathway which is independent of the Gi protein, but dependent on beta-arrestin. This corresponds to the MAP kinase pathway (Mitogen Activator Protein Kinase), which could be involved in the hypotensive effect of the Apelin. My work consisted of characterizing a physiological model such as the rat kidney juxtamedullary afferent arterioles (JMAA), to study if the signaling pathway mediated by beta-arrestin was involved in the vasodilatory effect of K17F. Knowing that AngII induces vasoconstriction by increasing intracellular calcium mobilization ([Ca2+]i), we have showed by measuring variations in arteriolar diameter and [Ca2+]i, that when the Gi signaling pathway is blocked by pertussis toxin (PTX), the vasorelaxant effect induced by K17F is not modify. This data suggests that the vasorelaxing effect of K17F on AngII pre-contracted JMAAs is Gi-independent protein. In the presence of PTX and various internalization inhibitors the vasorelaxant effect induced by K17F on AngII-pre-contracted JMAAs is completely blocked. In addition, no significant decrease in [Ca2+]i mobilization is observed in the presence of PTX and these inhibitors, when K17F is applied to the plateau phase of the AngII-induced calcium response. This is in line with our hypothesis, that the vasorelaxing effect of K17F is Gi-independent protein and beta-arrestin-dependent. ApelineR is a potential therapeutic target for the treatment of heart failure and water retention. Knowing that the half-life of the aperitif in the bloodstream is approximatly one minute. Another aspect of my thesis was to develop metabolically stable K17F analogues by two different strategies. First, we have substituted each of the residues of the aperitif with its D-series enantiomer or a synthetic amino acid. Secondly, we added a fluoroalkyl chain to the N-terminal end of K17F. These two strategies have enabled us to obtain several compounds, the most active of which are P92 and LIT01-196. These retain pharmacological properties identical to those of K17F and have a plasma half-life significantly higher compared to the endogenous peptide. These two analogues have been shown to be active in vivo with the ability to reduce blood pressure and reduce vasopressin secretion in the blood leading to an increase in aqueous diuresis
3
Paradis, Justine. "Rôles non-canoniques des arrestines dans la signalisation et l’endocytose des récepteurs couplés aux protéines G." Thèse, 2017. http://hdl.handle.net/1866/20229.
Full textBook chapters on the topic "Internalization inhibitors"
1
Jiang, Fei, Naiguo Xing, Taiyong Lv, Zhanliang Sun, and Yan Zhao. "Effects of Eluting Volumes to Isolation Efficiencies in Manual Synthesis of Ga-68 Labelled FAPI-04." In Springer Proceedings in Physics, 270–75. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1023-6_25.
Full textAbstract:
AbstractAmong different FAPIs (fibroblast activation protein inhibitors) developed for PET imaging, 68Ga-FAPI-04 has demonstrated the most impressive properties with low nanomolar affinity to FAP, near-complete internalization of radioactivity bound to FAP, and rapid blood clearance. The application of 68Ga-FAPI-04 has been extended to 28 different kinds of clinical cancer detection. The manual synthesis of 68Ga-FAPI-04 is like other 68Ga-labeling peptides, such as PSMA-11 and DOTATATE. However, because the radiochemical conversion (RCC) is about 90%, it is required to conduct a purification and isolation process to meet the required standard for clinical application. The purpose of this work is to characterize the increase of isolation efficiency (IE) by increasing the volume of eluting liquid applied to C18 columns and sterile filters. We designed an experiment and measured the residual activity distribution on both C18 columns and sterile filters for different eluting volumes. We characterized the change of activity residuals and isolation efficiencies with different eluting volumes in the process of purification and isolation. As a result, it was found that there were more activity leftovers on sterile filters than on C18 columns. By increasing the eluting volume from 6 mL to 12 mL, we measured the average IE being improved from 62.4% to 87.4%, which is greatly beneficial to clinical applications. In addition, the fluctuation of IE which might come from the different radiolabeling operators or materials used in the experiment, was also obviously decreased from 11.3% to 4.5%. This method has been proven to be efficient in the production of 68Ga-FAPI-04.
Conference papers on the topic "Internalization inhibitors"
1
Barrott, Jared J., Aaron P. Smith, Takuya Osada, Nimmi Ramanujam, Michael R. Zalutsky, Kim Lyerly, and Timothy A. J. Haystead. "Abstract C86: Tethered Hsp90 inhibitors carrying optical or radioiodinated probes reveal selective internalization of ectopic Hsp90 in malignant breast tumor cells." In Abstracts: AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics--Oct 19-23, 2013; Boston, MA. American Association for Cancer Research, 2013. http://dx.doi.org/10.1158/1535-7163.targ-13-c86.
Full text
2
Yalcin, Huseyin, Hissa Al-Thani, and Samar Shurbaji. "Development and In Vivo Testing of Smart Nanoparticles for Enhanced Anti-Cancer Activity and Reduced Cardiotoxicity Associated with Tyrosine Kinase Inhibitors." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2021. http://dx.doi.org/10.29117/quarfe.2021.0088.
Full textAbstract:
Tyrosine kinase inhibitors (TKIs) are new generation of anti-cancer drugs with very high efficiency against cancer cells. However, TKIs are associated with severe cardiotoxicity limiting their clinical benefits. One TKI that has been developed recently but not explored much is Ponatinib. The use of nanoparticles as a better therapeutic agent to deliver anti-cancer drugs and reduce their cardiotoxicity has been recently considered. In this study, PLGA-PEG-PLGA nanoparticles were synthesized to deliver Ponatinib while reducing its cardiotoxicity for treatment of chronic myeloid leukemia. Shape, size, surface charge and drug uptake ability of these nanoparticles were assessed using transmission electron microscopy (TEM), ZetaSIZER NANO and high-performance liquid chromatography (HPLC). Cardiotoxicity of Ponatinib, unloaded and loaded PLGA-PEG-PLGA nanoparticles were studied on zebrafish model through measuring the survival rate and cardiac function parameters, to optimize efficient drug concentrations in an in vivo setting. These particles were tested on zebrafish cancer xenograft model in which, K562 cell line, was transplanted into zebrafish embryos. We showed that, at an optimal concentration (0.0025mg/ml), Ponatinib loaded PLGA-PEG-PLGA particles are non-toxic/non-cardio-toxic and are very efficient against cancer growth and metastasis. Zebrafish is a good animal model for investigating the cardiotoxicity associated with the anti-cancer drugs such as TKIs, to determine the optimum concentration of smart nanoparticles with the least side effects and to generate xenograft model of several cancer types. Also, PLGA-PEG-PLGA NPs could be good candidate for CML treatment, but their cellular internalization should be enhanced. This could be achieved by coating and labeling the surface of PLGA-PEG-PLGA NPs with specific ligands that are unique to CML cells.
3
Hutchinson, TE, S. Kuchibhotla, J. Zhang, ER Block, and JM Patel. "Peptide Mediated Caveolar PKC-α Phosphorylation Inhibits Its Internalization in Lung Endothelial Cells." In American Thoracic Society 2009 International Conference, May 15-20, 2009 • San Diego, California. American Thoracic Society, 2009. http://dx.doi.org/10.1164/ajrccm-conference.2009.179.1_meetingabstracts.a6123.
Full text
4
Allen, Fred D., Clara F. Asnes, Alan Wells, Elliot L. Elson, and Douglas A. Lauffenburger. "Alternative Pathways of Epidermal Growth Factor Receptor Mediated Contractile Force in NR6 Fibroblasts." In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0403.
Full textAbstract:
Abstract We investigated the contractile force response to epidermal growth factor (EGF) stimulation in 3T3-derived NR6 fibroblast cells in order to determine significant pathways of biochemical signaling that mediate the response. We examined the force generating specificity of the EGF receptor (EGFR) signaling mechanism by using mutant NR6 fibroblasts expressing variations of the EGFR construct. The wild-type (WT) cell presented the complete internalizing EGFR signaling construct while the c’973 cell presented an internalization-defective EGFR construct, and the M721 cell presented a kinase-defective EGFR construct making it signaling inert. Additionally we examined the roles of the phospholipasc C-γ (PLCγ) pathway by using the PLC inhibitor U73122 (1 μM) and the mitogen activated protein kinase (MAPK) pathway using the inhibitor PD98059 (10 μM) in the observed contractile force responses. We found that the WT cells showed a rapid but transient force increase within the first hour post-stimulation and the c’973 showed a more gradual increase in force which it sustained for several hours post-stimulation. Blocking the PLCγ activation in the WT cells reduced the peak force increase by 50% while blocking MAPK did not affect the force development in either WT or c’973 cells.
5
Hettmann, Thore, Matthias Schneider, Selam Ogbagabriel, Jiansong Xie, Gloria Juan, Susanne Hartmann, Robert Radinsky, and Daniel J. Freeman. "Abstract LB-306: U3-1287 (AMG 888), a fully human anti-HER3 mAb, inhibits HER3 activation and induces HER3 internalization and degradation." In Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC. American Association for Cancer Research, 2010. http://dx.doi.org/10.1158/1538-7445.am10-lb-306.
Full text
6
de Agostini, A., J. Marcum, and R. Rosenberg. "THE BINDING OF ANTITHROMBIN TO CAPILLARY ENDOTHELIAL CELLS GROWN IN VITRO." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643343.
Full textAbstract:
Cloned endothelial cells from rat epididymal fat pads synthesize anticoagulantly active heparan sulfate proteoglycans containing the disaccharide, GlcA→ AMN-3,6-O-SO3, which is a marker for the antithrombin-binding domain of heparin. To demonstrate that antithrombin (AT) binds to cell surface heparan sulfate, a binding assay employing 125I-AT and cell monolayers has been developed. Post-confluent endothelial cells (7 days) were incubated with radiolabeled AT for 1 h at 4° and washed with PBS. Bound radioactivity was quantitated after solubilizing whole cells. Under these conditions, ∼1% (2174±50 cpm/5x104 cells) of the 125I-AT bound to the endothelial cell monolayer, whereas none of the radiolabeled protein bound to CHO cells or bovine smooth muscle cells. Utilization of unlabeled AT (1 μM) in experiments conducted as described above resulted in a reduction (73%) of the binding of the labeled species to endothelial cells. To assess whether heparan sulfate was responsible for AT binding, cell monolayers were incubated for 1 h at 37° with purified Flavobacterium heparinase (0.2 units). Over 90% of 125I-AT binding to these cellular elements was suppressed with the bacterial enzyme. Internalization of radiolabeled AT by endothelial cells was examined by incubating the protease inhibitor and cells at 4° and 37 . An initial rapid binding was observed at both temperatures. At 4° AT binding plateaued within 15 min, whereas at 37° binding did not plateau until 60 min and was 30% greater than that observed at 4. These data suggest that surface-associated AT can be internalized by endothelial cells. In addition, AT binding was shown to increase with the length of endothelial cell postconfluence, indicating an accumulation of heparan sulfate by these cells during quiescence. In conclusion, our studies support the hypothesis that the vascular endothelium is coated with heparan sulfate-bound AT, which is responsible for the antithrombotic properties of these natural surfaces.
7
Wortinger, Mark A., Wei Zeng, Wei Jennifer Yang, Victoria Peek, Lei Yan, Jirong Lu, Chi-Kin Chow, et al. "Abstract 695: LA480, a c-Met antibody with neutralization and internalization properties, inhibits HGF-dependent and HGF-independent c-Met pathway activation and tumor growth." In Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC. American Association for Cancer Research, 2010. http://dx.doi.org/10.1158/1538-7445.am10-695.
Full text
8
Dupuy, E., P. S. Rohrlich, and G. Tobelem. "HEPARIN STIMULATES FIBROBLAST GROWTH INDUCED BY PDGF." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643750.
Full textAbstract:
Heparin binds to smooth muscle cells and endothelial cells. It inhibits the proliferation of the smooth muscle cells and modulates the growth of endothelial cells. Fibroblasts which represent an other cell type belonging to the vascular wall could also have their growth modified by heparin. We have at first, demonstrated that 125I unfractionated heparin bigds to cultured human skin fibroblasts with a Kd of 1.16 10 M.A low molecular weight heparin fraction (PK 10169) competed (50 %)with I unfractionated heparin, but at aless extent than cold unfractionated heparin(90%).As it has been reported with endothelial and smooth muscle cells, about 30% of the bound unfractionated heparin was internalized bythe fibroblasts. Heparin alone at the concentration ranges from 0 to 10-5M has no effect on fibroblast proliferation measured by the H thymidine uptake. When the cellproliferation was induced by pure PDGF, heparin potentiated markedly the fibroblast growth.The effgct started at 10-8 M heparinand reached a plateau from 10-6 M to 10-5 M. Similar stimulationwas observed when the growth was induced by FGF or EGF. Low molecular weight heparin enhanced the fibroblast proliferation induced by PDGF but at a less extent than unfractionated heparin, chondroltin sulfate has no effect. When added during the cell culture growth withhuman serum (5%), unfractionated heparin increased by 48 the cell proliferation as measured bycell counting at the 6th day of the culture. PDGF did not modify the heparin binding on fibroblast cultures either at 4°C or 37°C and did not alter the process of heparin internalization. JDGF binding to the cultured fibroblast (Kd 10.1 ± 3.4 10-10 M)was not modified by the presence of heparin when studied at 4°C.In conclusion : i) cultured human fibroblasts bind and internalize heparin, ii) heparinand heparin fraction stimulate the fibroblastgrowth induced by PDGF, iii) since the binding of PDGF is not modified by bound heparin, the mechanism of stimulation remains unknown.