Heterogeneity of hypoxic Ca2+ release in pulmonary and *

肺和 * 中缺氧 Ca2 释放的异质性

基本信息

批准号：
7104320
负责人：
YONG-XIAO WANG
金额：
$ 38.57万
依托单位：
ALBANY MEDICAL COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-09-19 至 2009-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7104320
关键词：
artery calcium channel calcium flux confocal scanning microscopy gene expression gene targeting genetically modified animals hypoxia laboratory mouse membrane activity muscle cells protein structure function pulmonary artery receptor coupling vascular smooth muscle vasoconstriction voltage /patch clamp

项目摘要

DESCRIPTION (provided by applicant): Hypoxia induces [Ca2+]I increase and associated vasoconstriction in pulmonary artery smooth muscle cells (PASMCs), but not in systemic artery myocytes. Futhermore, hypoxic Ca2+ and contractile responses are much greater in resistance than conduit PASMCs. However, very little is known about the cellular and molecular mechanisms underlying these functional differences. We and other investigators have consistently demonstrated that ryanodine receptor (RyR) Ca2+ release is critical for hypoxic [Ca2+]I increase and associated vasoconstriction in PASMCs. Our preliminary studies, together with previous findings, suggest that specific RyR subtypes (RyR1, RyR2 and RyR3) are differentially expressed in the vasculature. This heterogeneous nature of expression may contribute to observed differences in excitation-contraction coupling and hypoxic Ca2+ and contractile responses in various blood vessels. In addition, specific interactions of endogenous regulatory molecules FKBP12.6 (RyR inhibitor) and cADPR (RyR activator with distinct RyR subtypes may also play an important role in the heterogeneity of physiological and hypoxic Ca2+ release and vasoconstriction. To address these hypotheses, this proposal seeks to examine the following three questions (Specific Aims): Are RyR subtypes heterogeneously expressed in resistance and conduit pulmonary and mesenteric artery SMCs? 2) Is RyR Ca2+ release heterogeneous in resistance and conduit pulmonary and mesenteric artery SMCs? 3) Do the heterogeneities of RyR subtypes expression and RyR coupling to FKBP12.6 and cADPR explain differences in hypoxic Ca2+ release between resistance and conduit pulmonary and mesenteric artery SMCs? These aims will be pursued by using the state-of-the-art biophysical (confocal microscopy, patch clamp, etc), molecular and genetic approaches (gene knockout and over-expression). Thus, the findings from this proposal will extend our understanding of the cellular and molecular mechanisms that contribute to the differences and heterogeneity of physiological and hypoxic Ca2+ and contractile responses, and may identify novel therapeutic targets for pulmonary hypertension. The proposed studies are also of fundamental physiological significance with respect to the regulation of Ca2+ release in other cell types.

描述（由申请人提供）：缺氧会导致肺动脉平滑肌细胞 (PASMC) 中的 [Ca2+]I 增加以及相关的血管收缩，但不会导致全身动脉肌细胞中的血管收缩。此外，缺氧 Ca2+ 和收缩反应的阻力比导管 PASMC 大得多。然而，人们对这些功能差异背后的细胞和分子机制知之甚少。我们和其他研究人员一致证明，兰尼碱受体 (RyR) Ca2+ 释放对于 PASMC 中缺氧 [Ca2+]I 增加和相关血管收缩至关重要。我们的初步研究以及之前的发现表明，特定的 RyR 亚型（RyR1、RyR2 和 RyR3）在脉管系统中存在差异表达。这种表达的异质性可能导致观察到不同血管中兴奋-收缩耦合和缺氧 Ca2+ 和收缩反应的差异。此外，内源性调节分子 FKBP12.6（RyR 抑制剂）和 cADPR（具有不同 RyR 亚型的 RyR 激活剂）的特异性相互作用也可能在生理和缺氧 Ca2+ 释放和血管收缩的异质性中发挥重要作用。为了解决这些假设，本提案提出旨在研究以下三个问题（具体目标）： RyR 亚型在肺和肠系膜阻力和导管中的表达是否异质动脉 SMC 吗？ 2) RyR Ca2+ 释放在阻力和导管肺动脉和肠系膜动脉 SMC 中是否异质？ 3) RyR 亚型表达的异质性以及 RyR 与 FKBP12.6 和 cADPR 的耦合是否可以解释阻力和导管肺动脉和肠系膜动脉 SMC 之间缺氧 Ca2+ 释放的差异？这些目标将通过使用最先进的生物物理（共焦显微镜、膜片钳等）、分子和遗传学方法（基因敲除和过度表达）来实现。因此，该提案的研究结果将扩展我们对导致生理和缺氧 Ca2+ 以及收缩反应的差异和异质性的细胞和分子机制的理解，并可能确定肺动脉高压的新治疗靶点。所提出的研究对于其他细胞类型中 Ca2+ 释放的调节也具有基本的生理意义。