Aging impairments in angiotensin type 1 receptor actions

 描述(由申请人提供)：这项R21提案的总体目标是研究PEP7编码的短开放阅读框架在血管平滑肌细胞AT1aR作用的年龄相关变化中的作用。我们将验证与年龄相关的AT1aR密度失调导致血管平滑肌细胞衰老的假设，这部分是通过AT1aR剪接变量的失调，导致AT1aR内化和信号的失调。为了验证这一假设，在目标1中，我们将测定衰老对青年(4月龄)和老年(32月龄)Fischer大鼠血管平滑肌细胞AT1aR转录表达(E1，2，3和E1，3)、AT1R结合、受体内化率、AT1R信号通路和细胞增殖的影响。我们还将利用RNA干扰技术选择性地抑制这些年轻和老年大鼠血管平滑肌细胞中E1，2，3-AT1aR转录本的表达，并确定其对AT1R结合、内化、信号转导和细胞增殖的影响。在目标2中，我们将比较这些相同的参数在血管重塑障碍中的作用，以探讨PEP7在正常和异常衰老中的作用。

 DESCRIPTION (provided by applicant): The overall goal of this R21 proposal is to investigate the role of the PEP7 encoded short open reading frame in age-associated changes in AT1aR action in vascular smooth muscle cells. We will test the hypothesis that age-associated dysregulation of AT1aR densities contributes to vascular smooth muscle cell senescence in part through dysregulation of AT1aR splice variants, which leads to dysregulation of AT1aR internalization and signaling. To test this hypothesis, in Aim 1, we will determine the effect of aging on AT1aR transcript expression (E1,2,3 and E1,3), AT1R binding, rate of receptor internalization, AT1R signaling pathways and cell proliferation in vascular smooth muscle cells isolated from young (4 month old) and old (32 month old) Fischer rats. We will also use RNA interference to selectively inhibit expression of the E1,2,3-AT1aR transcript in vascular smooth muscle cells isolated from these young and old rats and determine the effect on AT1R binding, internalization, signaling and cell proliferation. In Aim 2, we will compare these same parameters in a disorder of vascular remodeling to investigate the role of PEP7 in normal and abnormal aging.