SIGNAL TRANSDUCTION IN VASCULAR SMOOTH MUSCLE

腺苷受体(AR)在维持和调节中起着重要作用 心血管功能。腺苷的生理作用范围从 变时性和变电性对血管调节的控制及其调节 平滑肌细胞的生长和迁移。充血性心力衰竭 与腺苷和Small的血管调节反应降低有关 血管痉挛。在这个项目中，研究人员将描述AR的特征 血管平滑肌细胞(VSMC)介导的跨膜信号 包括描述哪些AR存在、哪些效应器系统 AR如何调节生长和分化，如何在信号传递中使用 腺苷水平升高调节这些受体系统，以及这些 可以通过创建具有特定属性的突变AR来修改函数 强调AZAR。还将寻找证据来确定新的 发现VSMC中存在A2B和A3AR，因为生理数据是 与他们的存在相吻合。研究将在小学进行。 转化的VSMC系VSMCs在CHO和COS7细胞中的培养 野生型或突变型受体的。这一过程 关于脱敏的作用，我们将详细探讨 受体的磷酸化，细胞周期AR和 AR上潜在调控位点的突变如何改变模式 脱敏。有强有力的证据表明A1AR可以调节 血管平滑肌细胞中的多种效应系统，包括腺苷环化酶、磷脂酶 C和鸟苷环化酶。A2AR受体似乎只刺激 腺苷环化酶。有证据表明，A2AR的激活抑制和 A1AR刺激VSMC生长和DNA合成。这些路径将是 详细研究了有选择地区分 导致肌肉张力的调节，如抑制腺苷环化酶 对生长和DNA合成的调节，这很可能是由 将进行磷脂酶C。试图调节中小企业的增长 通过转染(感染)突变的受体，如结构性的 主动AR或显性负AR将使用高效率进行 腺病毒载体。总体目标将是理解AR中介 血管平滑肌细胞中的跨膜信号转导及其调控机制 有可能通过重组DNA技术操纵这些途径 潜在的治疗益处。

Adenosine receptors (AR) play a major role in maintaining and regulating cardiovascular function. The physiological effects of adenosine range from control of chronotropy and ionotropy to vasoregulation and the modulation of growth and migration of smooth muscle cells. Congestive heart failure is associated with decreased vasoregulatory response to adenosine and small vessel vasospasm. In this project, the investigators will characterize AR mediated transmembrane signalling in vascular smooth muscle cells (VSMC) including a delineation of which AR are present, which effector systems are utilized in signalling, how AR regulate growth and differentiation, how elevated levels of adenosine regulate these receptor systems and how these functions can be modified through creation of mutant ARs with particular emphasis on AZARs. Evidence will also be sought to determine if the newly found A2b and A3AR are present in VSMC since physiological data are consistent with their presence. Studies will be carried out in primary cultures of VSMCs, a transformed VSMC line and in CHO and COS7 cells transfected with wild type or mutant receptors. The process of desensitization will be probed in detail concerning the role of phosphorylation of the receptor, mechanisms by which the cell cycles AR and how mutation of potential regulatory sites on the AR changes the patterns of desensitization. Strong evidence exists that the A1AR can regulate multiple effector systems in VSMCs including adenylylcyclase, phospholipase C and guanylate cyclase. A2AR receptors appear to only stimulate adenylylcyclase. Evidence suggests that activation of A2ARs inhibit and A1ARs stimulate growth and DNA synthesis in VSMC. These pathways will be studied in detail and approaches to selectively differentiate pathways that lead to regulation of muscle tone such as inhibition of adenylylcyclase versus regulation of growth and DNA synthesis which may well be mediated by phospholipase C will be undertaken. Attempts to modulate growth of SMCs through transfection (infection) of mutant receptors such as constitutively active AR or dominant negative AR will be undertaken using high efficiency adenovirus vectors. The overall goal will be to understand AR mediated transmembrane signalling in VSMCs, how it is regulated and how it is possible to manipulate these pathways via recombinant DNA techniques for potential therapeutic benefit.