ALPHA 1 ADRENERGIC RESPONSES IN SMOOTH MUSCLE

本研究的目的是加深对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，这也可能对高血压动脉粥样硬化和血管生长具有临床意义。本研究主要有两个目的：1血管平滑肌和转染NIH3T3细胞中al受体的信号转导机制。al受体激活多种信号通路，包括MAP激酶、PI 3激酶和p70S6激酶。这些途径对于受体激活蛋白和DNA合成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。1一个。研究Ca2+在α 1受体介导的MAP激酶和p70S6激酶活化和酪氨酸蛋白磷酸化，特别是磷脂酶Cgamma中的重要作用机制。确定α 1受体在PI-3激酶亚型和p70S6激酶激活中的作用。1 c。α 1和血管紧张素II受体刺激血管平滑肌细胞的PI 3-激酶活性，但不刺激PKB，而PKB通常在PI 3-激酶下游被激活。导致PKB无法激活的机制是什么？2. α 1受体对基因表达的调控初步结果表明，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。我们提出利用微阵列基因芯片技术表征血管平滑肌α 1受体和特定α 1受体亚型诱导的HEK-293细胞的基因表达模式。然后，我们将详细描述α 1受体在mRNA和蛋白质水平上对已鉴定的具有特定生物学意义的基因表达的影响，并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.