A Functional Relationship between Specific NOS Isozymes and Beta-adrenergic Recep

特定NOS同工酶与β-肾上腺素能受体之间的功能关系

• 批准号: 7878659
• 负责人: Christopher Traynham
• 金额: $ 3.34万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7878659
• 关键词: Adrenergic Agents; Adrenergic Receptor; Agonist; Cardiac; Development; Functional disorder; Heart; Individual; Isoenzymes; Isoproterenol; Knock-out; Knockout Mice; Location; Measurement; Measures; Muscle Cells; NOS1 gene; NOS3 gene; Nitric Oxide; Nitric Oxide Synthase; Phosphorylation; Protein Isoforms; Proteins; Receptor Activation; Receptor Signaling; Regulation; Signal Pathway; Signal Transduction; Stimulus; Troponin I; Western Blotting; adrenergic; novel therapeutics; phospholamban; receptor; research study; response

DESCRIPTION (provided by applicant): An essential regulator of cardiac contractility is ¿-adrenergic receptor (¿AR) signaling. (¿1 and ¿2 receptors are the primary subtypes expressed in the heart. ¿1 receptors produce positive inotropic and lusitropic effects through modulation of the L-type Ca2+ channel, phospholamban (PLB) and troponin I (Tnl). ¿2 receptors are unique in that they only function as positive inotropes; these receptors promote contractility through regulation of the L-type Ca2+ channel. ¿AR signaling itself can be regulated by nitric oxide (NO) produced via NO synthase (NOS). Within the myocyte, two NOS isoforms are constitutively expressed: NOS1 and NOS3. NOS1 signaling has been shown to augment the functional response to non-specific ¿AR stimulation while NOS3 signaling reduces it. However, it remains to be determined what effect specific NOS isoforms have in the regulation of individual ¿AR receptors. Interestingly, NOS1 and ¿1 receptors have been shown to regulate contractility via similar protein targets (i.e.PLB), while NOS3 and ¿2 receptors regulate contractility through the L-type Ca2+ channel. Recently, NOS3 and ¿2 receptors have been shown to compartmentalize to similar locations within the myocyte. Therefore, we hypothesize NOS1 will increase the functional response due to ¿1 receptor activation with no modulation of ¿2 receptor signaling (Aim1). In addition, we hypothesize NOS3 will decrease the functional response due to ¿2 receptor activation with no modulation of ¿1 receptor signaling (Aim2). Functional experiments (i.e. measurement of Ca2+ transient, shortening amplitude, and L-type Ca2+channel current) and western blotting (PLB-phosphorylation) to investigate this proposed functional interaction will be conducted in isolated myocytes from wild type (WT, control), NOS1 knockout (KO) and NOS3 KO mice exposed to various ¿AR stimuli. Our study holds health-relatedness due to the fact that when ¿AR signaling is altered, this signaling pathway promotes contractile dysfunction and cardiac remodeling. Thus, it is crucial to determine how ¿AR signaling is regulated. With a deeper understanding of this phenomena, our study will make possible the development of new therapeutic treatments.

描述（由申请人提供）：心肌收缩力的一种重要调节因子是<$-肾上腺素能受体（<$AR）信号传导。（1和2受体是心脏中表达的主要亚型。1受体通过调节L-型Ca 2+通道、受磷蛋白（PLB）和肌钙蛋白I（TnI）产生正性肌力作用和负性肌力作用。 <$2受体的独特之处在于它们仅起正性肌力药的作用;这些受体通过调节L型Ca 2+通道促进收缩性。AR信号本身可以通过NO合成酶（NOS）产生的一氧化氮（NO）来调节。在肌细胞内，两种NOS亚型组成型表达：NOS 1和NOS 3。NOS 1信号转导增强了对非特异性AR刺激的功能反应，而NOS 3信号转导降低了这种反应。然而，特异性NOS亚型在调节个体AR受体中的作用仍有待确定。有趣的是，NOS 1和1受体已被证明通过类似的蛋白质靶点（即PLB）调节收缩性，而NOS 3和NOS 2受体通过L型Ca 2+通道调节收缩性。最近，NOS 3和NOS 2受体已被证明在肌细胞内区室化到相似的位置。因此，我们假设NOS 1将增加由于<$1受体激活而不调节<$2受体信号传导（Aim 1）的功能反应。此外，我们假设NOS 3将降低由于<$2受体激活而不调节<$1受体信号传导（Aim 2）的功能反应。将在来自暴露于各种AR刺激的野生型（WT，对照）、NOS 1敲除（KO）和NOS 3 KO小鼠的分离的肌细胞中进行功能性实验（即，Ca 2+瞬变、缩短幅度和L型Ca 2+通道电流的测量）和蛋白质印迹（PLB-磷酸化）以研究该提出的功能性相互作用。我们的研究认为与健康相关，因为当AR信号被改变时，这种信号通路会促进收缩功能障碍和心脏重塑。因此，确定AR信号是如何调节的至关重要。随着对这一现象的深入了解，我们的研究将使开发新的治疗方法成为可能。