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The Global ETD Search service is a free service for researchers
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Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 1 to 5 of 5 (0.057 seconds)| 1 |
Integrin Mediated Mechanotransduction in Renal Vascular Smooth Muscle CellsBalasubramanian, Lavanya 30 October 2007 (has links)
Integrins are transmembrane heterodimeric proteins that link extracellular matrix (ECM) to cytoskeleton and have been shown to function as mechanotransducers in non-muscle cells. Synthetic integrin-binding peptide triggers Ca2+ mobilization and contraction in vascular smooth muscle cells (VSMCs) from rat afferent arteriole, indicating that interactions between ECM and integrins modulate vascular tone. RGD, an integrin binding peptide, triggered contraction in cultured VSMCs as observed by Electric Cell-Substrate Impedance Sensing technique. To examine whether integrins transduce extracellular mechanical stress into intracellular Ca2+ signaling events in VSMCs, unidirectional mechanical force was applied to freshly isolated renal VSMCs through paramagnetic beads coated with fibronectin (FN, natural ligand of α5β1 integrin in VSMCs). Pulling of fibronectin-coated beads with electromagnet triggered Ca2+ sparks, followed by global Ca2+ mobilization. Paramagnetic beads coated with low-density lipoprotein (LDL), whose receptors are not linked to cytoskeleton, were minimally effective in triggering Ca2+ sparks and global Ca2+ mobilization. Pre-incubation with ryanodine, cytochalasin-D, or colchicine substantially reduced the occurrence of Ca2+ sparks triggered by fibronectin-coated beads. Binding of VSMCs with antibodies specific to the extracellular domains of alpha5 and beta1 integrins triggered Ca2+ sparks simulating the effects of fibronectin-coated beads. Anti-β2- integrin antibody served as the negative control. Traction force microscopy studies showed that only the force transduced via integrins could potentially trigger cytoskeletal remodeling in cultured VSMCs. Atomic force microscopy revealed a significant increase in surface roughness in VSMCs when treated with RGD peptide though there was no difference in the maximum deflection of the force curves. Pre-incubation of microperfused afferent arterioles with ryanodine or integrin specific binding peptide inhibited pressure-induced myogenic constriction. In conclusion, integrins transduce mechanical force into intracellular Ca2+ signaling events in renal VSMCs. Integrin-mediated mechanotransduction is probably involved in myogenic response of afferent arterioles. Thus, integrins can potentially act as sensors for myogenic response phenomenon and affect the autoregulatory mechanism in the vasculature.
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Calcium sparks enhance the tissue fluidity within epithelial layers and promote apical extrusion of transformed cells / カルシウムスパークは上皮層での組織流動性を亢進し、変異細胞の管腔側への逸脱を促進するKuromiya, Keisuke 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(医科学) / 甲第24533号 / 医科博第147号 / 新制||医科||10(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 篠原 隆司, 教授 松田 道行, 教授 伊藤 貴浩 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
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Role of Oxidative Stress in Mediating Elevated Atrial Fibrillation by Tumor Necrosis Factor-alphaMirkhani, S. Moniba 21 March 2012 (has links)
Atrial fibrillation (AF), the most common arrhythmia encountered in clinical practice, is a major source of morbidity and mortality, and is highly associated with inflammation and oxidative stress. In the present study, we show that acute exposure of mice atrial tissue to tumor necrosis factor-α (TNF-α) increases susceptibility to AF. We further show that acute exposure to TNF-α led to increased spontaneous sarcoplasmic reticulum (SR) calcium release and generated triggered activities in isolated mice atrial myocytes. This increase in spontaneous SR calcium activity was found to be due to elevated reactive oxygen species production from mitochondria and NADPH oxidase sources triggered by TNF-α. Hence we concluded that acute exposure to TNF-α leads to elevated oxidative stress that increases spontaneous SR Ca2+ release and triggered activity through which it can lead to AF induction and maintenance
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Role of Oxidative Stress in Mediating Elevated Atrial Fibrillation by Tumor Necrosis Factor-alphaMirkhani, S. Moniba 21 March 2012 (has links)
Atrial fibrillation (AF), the most common arrhythmia encountered in clinical practice, is a major source of morbidity and mortality, and is highly associated with inflammation and oxidative stress. In the present study, we show that acute exposure of mice atrial tissue to tumor necrosis factor-α (TNF-α) increases susceptibility to AF. We further show that acute exposure to TNF-α led to increased spontaneous sarcoplasmic reticulum (SR) calcium release and generated triggered activities in isolated mice atrial myocytes. This increase in spontaneous SR calcium activity was found to be due to elevated reactive oxygen species production from mitochondria and NADPH oxidase sources triggered by TNF-α. Hence we concluded that acute exposure to TNF-α leads to elevated oxidative stress that increases spontaneous SR Ca2+ release and triggered activity through which it can lead to AF induction and maintenance
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Über die differentielle Regulation von Ionenkanälen in spezifischen Nanodomänen atrialer und ventrikulärer Kardiomyozyten / Differential Regulation of Ion Channels in Specific Nanodomains of Atrial and Ventricular CardiomyocytesBrandenburg, Sören 29 June 2017 (has links)
No description available.
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