Properties of Clca Channels in Vascular Myocytes

血管肌细胞 Clca 通道的特性

基本信息

批准号：
7435283
负责人：
Normand Leblanc
金额：
$ 30.93万
依托单位：
UNIVERSITY OF NEVADA RENO
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-07-01 至 2010-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7435283
关键词：
Anions Appendix Architecture Arteries Behavior Biochemical Biochemistry Blood Vessels Calcineurin Calmodulin Candidate Disease Gene Cell Line Cell Membrane Permeability Cell Volumes Cell membrane Chloride Ion Class Computer Simulation Condition Coronary Cytoplasm Data Dependence Development Disease Equilibrium Etiology Follow-Up Studies Future Gene Family Goals Grant Health Human Image Imaging technology Journals Kinetics Knowledge Lung Maintenance Mammalian Cell Measures Mechanics Membrane Membrane Potentials Messenger RNA Modeling Molecular Molecular Biology Techniques Muscle Cells Nature Oryctolagus cuniculus Permeability Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Physiological Play Property Protein Dephosphorylation Protein Isoforms Protein Phosphatase 2A Regulatory Subunit PR53 Protein Serine/Threonine Phosphatase Pulmonary Circulation Pulmonary Hypertension Pulmonary artery structure Pump Recommendation Regulation Relative (related person)Reporting Research Research Personnel Resistance Rest Role Side Smooth Muscle Smooth Muscle Myocytes Specificity Swelling System Testing Thinking Transcript Vascular Smooth Muscle Vasoconstrictor Agents Veins calcineurin phosphatase calmodulin-dependent protein kinase II cell type member novel patch clamp programs research study size symporter vascular bed voltage

项目摘要

DESCRIPTION (provided by applicant): The long term objective of the applicant's research program is to unravel the ionic mechanisms that are involved in the control of electrical and mechanical activities of the smooth muscle cells of large conduit and resistance-sized vessels in health and disease. In smooth muscle cells, chloride ions (Cl-) are not passively distributed across the cell membrane. It is thought that this anion is actively accumulated in the cytoplasm by various anion transporters. Such a high internal level of Cl- (~ 40 mM) results in a predicted equilibrium for Cl- (ECl) that is more positive (-25 mV) than the resting membrane potential (RMP) of vascular smooth muscle cells (~ -40 to -60 mV). Because of this deviation between ECl and RMP, any increase in permeability to Cl- would result in passive Cl" efflux, membrane depolarization and increased vascular tone. In spite of our knowledge about high resting membrane permeability to Cl- in smooth muscle cells, the nature of this basal anion conductance still remains undefined. This proposal is focused on elucidating the mechanisms involved in the regulation by phosphorylation mechanisms involving calmodulin-dependent kinase II (CaMKII) and serine/threonine phosphatases (Calcineurin and PP2A) of a Cl- channel activated by intracellular Ca2+ (ClCa ) in pulmonary arterial smooth muscle cells, and how this might impact on the electrical and vasoactive properties of the pulmonary circulation. 4 Specific Aims are proposed in this grant: (1) determine the effect of general phosphorylation status on the biophysical properties of Clca channels in rabbit pulmonary artery smooth muscle cells; (2) determine the relative role of CaMKII and serine/threonine phosphatases in the regulation of ClCa channels in rabbit pulmonary artery smooth muscle cells; (3) determine the physiological impact of phosphatase regulation of ClCa channels on membrane potential, Ca2+ transients and tone in pulmonary arterial smooth muscle cells and intact pulmonary arteries; and (4) clone and express 3 candidate genes encoding Ca2+-activated Cl- channels in rabbit pulmonary artery and evaluate their physiological relevance to the native channels. A strong team of collaborating investigators will use a wide array of electrophysiological, biochemical and molecular biology techniques, as well as confocal imaging technology and computer simulations to accomplish the above goals. The etiology of pulmonary hypertension (PH) in humans is still poorly understood although it is becoming increasingly clear that defective ionic mechanisms may play a role in this disease. Because of their potential importance as an excitatory mechanism in pulmonary arteries, impaired regulation and/or expression of Clca channels could potentially participate in PH. The proposed studies will not only advance our knowledge about their basic properties, but should also pave the way for the development of future therapies to treat PH.

描述（由申请人提供）：申请人研究计划的长期目标是揭示与健康和疾病中大型导管和阻力尺寸血管平滑肌细胞的电气和机械活性有关的离子机制。在平滑肌细胞中，氯离子（Cl-）并非被动地分布在细胞膜上。人们认为，该阴离子由各种阴离子转运蛋白积极积累。如此高的内部Cl-（〜40 mm）水平导致Cl-（ECL）的预测平衡比血管平滑肌细胞的静息膜电位（RMP）更正（-25 mV）（〜-40至-60 mV）。由于ECL和RMP之间的这种偏差，对Cl-的渗透性的任何增加都会导致Cl'Cl“外排”，膜去极化和血管张力的增加。尽管我们对高静止膜通透性的了解，但在平滑肌细胞中对Cl- cl- cl-在平滑肌细胞中的了解仍然不确定，但这种机制仍然涉及这种机制。该机构仍然涉及该机制的范围。涉及钙调蛋白依赖性激酶II（CAMKII）和丝氨酸/苏氨酸磷酸酶（钙调蛋白和PP2A）在肺动脉平滑肌细胞中被细胞内Ca2+（CLCA）激活的CL通道，以及这可能会影响电气和血管的孔子循环效果。兔肺动脉平滑肌细胞中CLCA通道的生物物理性质的磷酸化状态（2）确定CaMKII和丝氨酸/苏氨酸磷酸酶在CLCA通道中的相对作用动脉平滑肌肉细胞和完整的肺动脉；完成上述目标。开发未来治疗pH的方法。