MYOSIN LIGHT CHAIN KINASE IN SMOOTH MUSCLE PROLIFERATION

描述(改编自申请者摘要)：心血管疾病 这是导致发病率和死亡率的主要原因。Mamy的主要并发症 心血管疾病的治疗形式是由以下原因引起的再狭窄 内膜增生症。当血管内膜增生时，血管内 血管损伤的愈合过程失控。除法和 内弹力层内膜平滑肌细胞的迁移 是血管内膜增生的重要特征。虽然分子 调节平滑肌增殖和迁移的机制是 尚不完全了解的是，平滑肌细胞从 收缩、静止状态变为增殖、迁移、合成状态 似乎很重要。这种转换是一个复杂的过程， 由促增殖激活和/或失活所致 抗增殖信号通路。血管内皮细胞的研究进展 其他细胞已经显示了小G蛋白和激活的MAP 蛋白水解酶家族在调节细胞增殖和 迁移。小G蛋白/MAP激酶信号涉及细胞内 肌动蛋白、细胞骨架和肌球蛋白II与这些变化有关。这个 肌球蛋白光对肌动蛋白-肌球蛋白II相互作用的调节 链激酶型。肌球蛋白轻链激酶也被认为调节 有丝分裂的时间。研究人员最近发现，肌球蛋白光 链激酶被磷酸化，并受位点特异性的差异调节 MAP激酶家族中两个不同成员的磷酸化 蛋白质。位点特异性肌球蛋白轻链激酶活性的研究 胞外受体激酶或p21激活的激酶的磷酸化是 这是调节平滑肌细胞增殖的关键事件之一。这个 具体目标是a)表征平滑肌的增殖 培养血管时细胞和新生内膜的形成，b) 建立MAP激酶激活/失活的时间序列， 肌球蛋白轻链激酶磷酸化和活性的变化 平滑肌增殖和c)通过表达 肌球蛋白轻链激酶或结构性活性p21的催化结构域 激活的激酶对平滑肌增殖的影响。这些实验将是 在培养的血管上进行，当培养的血管在 在特定条件下培养，并在分离的平滑肌细胞上培养。 因此，这些实验将检验一个新的假设，它们将被执行 一种潜在的重要的内膜增生模型，他们将 增加我们对调节Smoth的分子机制的理解 肌肉增殖。这反过来可能导致改善治疗 内膜增生症。

DESCRIPTION (Adapted from Applicant's Abstract): Cardiovascular disease is a major cause of morbidity and mortality. A major complication in mamy forms of therapy for cardiovascular disorders is restenosis resulting from intimal hyperplasia. Intimal hyperplasia occurs when the intravascular healing process to vascular injury goes out of control. Division and migration of medial smooth muscle cells across the internal elastic lamina are important features of intimal hyperplasia. Although the molecular mechanisms regulating smooth muscle proliferation and migration are incompletely understood, the conversion of smooth muscle cells from a contractile, quiescent state to a proliferative, migratory, synthetic state appears to be important. This conversion is a complex process that appears to result from the activation of pro-proliferative and/or the inactivation of anti-proliferative signalling pathways. Studies on smooth muscle and other cells have shown that small G proteins and the activation of the MAP kinase family of enzymes play central roles in regulating proliferation and migration. Small G protein/MAP kinase signalling involves changes in the actin cytoskeleton and myosin II has been implicated in these changes. The actin-myosin II interaction in smooth muscle is regulated by myosin light chain kinase. Myosin light chain kinase is also thought to regulate the timing of mitosis. The investigators have recently found that myosin light chain kinase is phosphorylated and differentially regulated by site specific phosphorylation by two different members of the MAP kinase family of proteins. Myosin light chain kinase activity by site-specific phosphorylation by extracellular receptor kinase or p21 activated kinase is one of the key events regulating smooth muscle cells proliferation. The specific aims are to a) characterize the proliferation of smooth muscle cells and the formation of a neo-intima when blood vessels are cultured, b) establish the temporal sequences of MAP kinase activation/inactivation, changes in the phosphorylation and activity of myosin light chain kinase and smooth muscle proliferation and c) test the hypothesis by expressing the catalytic domain of myosin light chain kinase or constitutively-active p21 activated kinase on smooth muscle proliferation. These experiments will be performed on cultured blood vessels, which develop a neo-intima when cultured under defined conditions, and on isolated smooth muscle cells. Thus, these experiments will test a novel hypothesis, they will be performed on a potentially important model of intimal proliferation and they will increase our understanding of the molecular mechanisms that regulate smooth muscle proliferation. This, in turn could result in improved therapy for intimal hyperplasia.