ALPHA 1 ADRENERGIC RESPONSES IN SMOOTH MUSCLE

该提案的目标是加深对α 1肾上腺素能受体激活的后果的理解，重点是血管平滑肌细胞中的信号转导机制。 初步数据表明，与肽生长因子相比，α 1受体对血管细胞生长的贡献被低估了。 该提议有助于继续探索生物学上有趣的α 1受体机制，这些机制也可能对高血压的动脉粥样硬化和血管生长具有临床意义。 本课题的主要目的有两个：1、血管平滑肌和转染细胞α 1受体的信号转导机制。α 1受体激活多种信号传导途径，包括MAP激酶、PI 3-激酶和p70 S6激酶。 这些途径对于蛋白质和DNA合成中受体激活的增加具有重要意义。 本研究的主要目的是深入了解α 1受体激活这些信号通路的机制，并将其与血管紧张素II和其他生长因子（如血小板衍生生长因子）的作用进行对比。1A.研究Ca ~（2+）在α 1受体介导的MAP激酶和p70 S6激酶激活以及酪氨酸蛋白磷酸化，特别是磷脂酶C γ磷酸化中的重要作用机制。1B.确定α 1受体在PI-3激酶亚型和p70 S6激酶激活中的作用。1C.α 1和血管紧张素II受体刺激血管平滑肌细胞中的PI 3-激酶活性，但不刺激通常在PI 3-激酶下游被激活的PKB。 PKB不能激活的机制是什么？2.初步结果表明，α 1受体增加了一系列基因的表达，包括神经生长因子和各种酪氨酸激酶和转录因子。 我们建议使用微阵列基因芯片技术的特点，在血管平滑肌中的α 1受体和特定的α 1受体亚型转染HEK-293细胞诱导的基因表达的模式。然后，我们将详细描述alpha 1受体对特定生物学目的基因表达的影响，包括mRNA和蛋白质水平，以及研究这些蛋白质表达变化的可能生物学意义。

The goals of this proposal relate to deepening understanding of the consequences of activation of alpha1 adrenergic receptors, with emphasis on signal transduction mechanisms in vascular smooth muscle cells. Preliminary data indicate that the contribution of alpha1 receptors to vascular cell growth has been underestimated in comparison to peptide growth factors. The proposal serves to continue exploration of biologically interesting alpha1 receptor mechanisms that could also have clinical significance for atherosclerosis and vascular growth in hypertension. The proposal has two major aims: 1 Signal transduction mechanisms of al receptors in vascular smooth muscle and transfected NIH3T3 cells. al receptors activate a variety of signaling pathways including MAP kinases, PI 3-kinase, and p70S6 kinase. These pathways have importance for receptor-activated increases in protein and DNA synthesis. The primary purpose of this aim is to develop deeper insight into the mechanisms used by alpha1 receptors to activate these signaling pathways and to contrast them with the actions of angiotensin II and other growth factors such as platelet derived growth factor. 1A. Investigate the mechanism for the essential role of Ca2+ in alpha1 receptor- mediated activation of MAP kinase and p70S6 kinase and tyrosine protein phosphorylation, especially of phospholipase Cgamma. 1B. Determine the role of alpha1 receptors in the activation of PI-3 kinase isoforms and p70S6 kinase. 1C. alpha1 and angiotensin II receptors stimulate PI 3-kinase activity in vascular smooth muscle cells yet do not stimulate PKB which is generally activated down-stream of PI 3-kinase. What is the mechanism responsible for this inability to activate PKB? 2. Regulation of gene expression by alpha1 receptors toys Preliminary results suggest that alpha1 receptors increase expression of a range of genes, including nerve growth factor and various tyrosine kinases and transcription factors. We propose to characterize using microarray gene chip technology the pattern of gene expression induced by alpha1 receptors in vascular smooth muscle and by specific alpha1 receptor subtypes in transfected HEK-293 cells. We will then characterize in detail the effects of alpha1 receptors on expression of identified genes of particular biological interest, both at the mRNA and protein level, as well as investigating possible biological implications of the change in expression of these proteins.