MUSCARINIC SIGNLING: REGULATION OF VENTRICULAR FUNCTION

毒蕈碱信号传导：心室功能的调节

• 批准号: 7184907
• 负责人: Ulrike Mende
• 金额: $ 31.35万
• 依托单位: RHODE ISLAND HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7184907
• 关键词: Adenoviridae; G protein; SDS polyacrylamide gel electrophoresis; biological signal transduction; calcium channel; calcium flux; echocardiography; genetically modified animals; green fluorescent proteins; heart contraction; heart ventricle; laboratory mouse; laboratory rat; muscarinic receptor; phosphorylation; polymerase chain reaction; protein structure function; receptor coupling; receptor expression; transfection /expression vector; voltage /patch clamp; western blottings

DESCRIPTION (provided by applicant): The mechanical performance of the heart is determined by its intrinsic contractile properties and is subject to counterbalancing regulation by the autonomic nervous system. While a-adrenergic stimulation increases pump function, cholinergic stimulation decreases it by reducing the conductance of the L-type Ca2+ channel (ICa-L) previously elevated by cAMP ("accentuated antagonism"). Two different G proteins, Go and Gi-2, have been implicated to be absolutely required for this effect, but their exact role and interplay as well as the signaling mechanisms involved are still poorly defined. We have preliminary data suggesting that Go protein may also regulate Ca2+ cycling and force generation by altering excitation contraction (E-C) coupling and the responsiveness of the myofilaments to Ca2+. The overall goal of this investigation is to define the signaling mechanisms that link Go and/or Gi2 protein activation to the muscarinic regulation of ventricular Ca2+ fluxes and contractile function and to test the hypothesis that selective interference with this pathway can be utilized to enhance contractile function in vivo. The Specific Aims are: (1) to test the hypothesis that expression of activated Gao regulates Ca2+ cycling and cell shortening in the ventricular myocardium by increasing (rather than decreasing) E-C coupling gain and myofilament responsiveness to Ca2+ in concert to its blunting effect on ICa-L, (2) to test whether cell-permeable peptide import can be adapted for introduction of dominant negative inhibitory peptides into adult ventricular cardiocytes as an alternative and possible improvement to adenoviral gene transfer, (3) to test the hypotheses that Go and Gi2 proteins act in concert as mediators of M2-receptor effects on ICa-L, Ca2+ cycling and contractility and that both Galpha and Gbetagamma contribute to this effect (4) to test the hypothesis that interference with Go and/or Gi-mediated signal transduction in the ventricular myocardium can be utilized to enhance ventricular contractile function. Muscarinic "accentuated antagonism" is of physiological importance both under normal and pathophysiological conditions. A better understanding of the processes involved in muscarinic receptor-mediated opposition of beta-adrenergic stimulation and blunting of contractile function may form the basis for therapeutic interventions aimed at the long-term autonomic input to the heart through a so far underexplored mechanism.

描述（由申请人提供）：心脏的机械性能取决于其内在的收缩特性，并受到自主神经系统的平衡调节。尽管A-肾上腺素能刺激增加了泵的功能，但胆碱能刺激通过降低了先前由CAMP升高的L型Ca2+通道（ICA-L）的电导来降低它（“重音拮抗”）。两种不同的G蛋白GO和GI-2被认为是这种效果绝对需要的，但是它们的确切作用和相互作用以及所涉及的信号机制仍然很差。我们有初步数据表明，GO蛋白还可以通过改变激发收缩（E-C）耦合以及肌丝对Ca2+的响应性来调节Ca2+循环和力产生。这项研究的总体目标是定义将GO和/或GI2蛋白激活与心室CA2+通量和收缩功能的毒蕈碱调节联系起来的信号传导机制，并测试可以将选择性干扰与该途径进行选择性的假设，以增强体内的收缩功能。 The Specific Aims are: (1) to test the hypothesis that expression of activated Gao regulates Ca2+ cycling and cell shortening in the ventricular myocardium by increasing (rather than decreasing) E-C coupling gain and myofilament responsiveness to Ca2+ in concert to its blunting effect on ICa-L, (2) to test whether cell-permeable peptide import can be adapted for introduction of dominant negative inhibitory peptides into成年的心室心脏细胞是腺病毒基因转移的一种替代性和可能的​​改善，（3）测试GO和GI2蛋白的假设，作为M2受体对ICA-L，Ca2+ CA2+循环和收缩性的介体的介体作用，并导致Galpha和Gbetagamma对效应的影响（4心室心肌的转导可用于增强心室收缩功能。在正常和病理生理条件下，毒蕈碱的“突出拮抗”在生理重要性上都是生理重要的。更好地理解毒蕈碱受体介导的β-肾上腺素能刺激和收缩功能钝化的反对的过程可能构成旨在通过到目前为止未经充实的机制对心脏进行长期自主性输入的治疗干预措施的基础。

项目成果

Regulator of G protein signaling 2 is a functionally important negative regulator of angiotensin II-induced cardiac fibroblast responses.

• DOI: 10.1152/ajpheart.00026.2011
• 发表时间: 2011-07
• 期刊: American journal of physiology. Heart and circulatory physiology
• 作者: Peng Zhang;Jialin Su;M. King;A. Maldonado;Cindy Park;U. Mende

Enhanced calcium cycling and contractile function in transgenic hearts expressing constitutively active G alpha o* protein.

• DOI: 10.1152/ajpheart.00584.2007
• 发表时间: 2008-03
• 期刊: American journal of physiology. Heart and circulatory physiology
• 作者: Ming Zhu;A. Gach;Gongxin Liu;Xiaomei Xu;C. Lim;Julie X. Zhang;L. Mao;Kurt J. Chuprun;W. Koch;R. Liao;G. Koren;B. Blaxall;U. Mende