Elucidation of the Molecular Mechanism of Atherosclerosis Induced by Unsaturted Lysophosphatidic Acid and Establishment of the Anti-athrosclerotic Therapy

动脉粥样硬化的分子机制仍有待阐明。本研究的目的是阐明不饱和lpa在动脉粥样硬化中的病理意义，并为动脉粥样硬化的治疗提供新的策略。进行了以下实验：1、新型不饱和lpa特异性受体的克隆：后续实验已进入最后阶段；(1)利用不饱和lpa刺激ERK和p38MAPK的活化作为功能标记进行表达克隆；(2)利用放射性标记的不饱和lpa作为配体进行受体结合实验。2、动脉粥样硬化因子的鉴定：利用维持分化表型的血管平滑肌细胞（VSMCs）的原代培养系统，我们证明了由动脉粥样硬化因子引发的血管平滑肌细胞释放表调节蛋白，并作为动脉粥样硬化进展的主要自分泌/旁分泌因子（Circulation. 2003 18;108:2524-9）。不饱和lpa对动脉粥样硬化的体内影响。我们证明，用18:1而不是18:0 LPA治疗大鼠颈总动脉（CCAs）可有效诱导新内膜形成，并且CCAs中ERK和p38MAPK通路的协同激活对于18:1 LPA诱导的体内血管重构至关重要（《循环》，2003:1746-52）。3、阐明参与动脉粥样硬化发病机制的细胞内信号转导：我们证明了IGF-I激活了分化的VSMCs中的蛋白酪氨酸磷酸酶SHP-2，激活的SHP-2随后去磷酸化胰岛素受体底物-1(IRS-1)，导致ERK和p38MAPK通路的激活被阻断，这两个通路在VSMCs的去分化中起关键作用。结果表明，IRS-1/SHP-2相互作用是VSMCs表型调控的开关（J.Biol.Chem.）。2004 279:40807 - 40818)。4、动脉粥样硬化小鼠的产生：我们产生了过表达脂质合成相关酶的转基因小鼠，预计脂质代谢会出现紊乱。少

The molecular mechanism of atherosclerosis still remains to be elucidated. The purposes of this study are to clarify the pathological significance of unsaturated-LPA in atherosclerosis and to develop the novel therapeutic strategy for atherosclerosis. Following experiments were performed. 1,Cloning of the novel unsaturated-LPA specific receptor : We are in the final step in the following experiments ; (1)Expression cloning using unsaturated-LPA stimulated activation of the ERK and p38MAPK as a functional marker, (2)The receptor binding experiment using radiolabeled unsaturated-LPA as a ligand. 2,Identification of the atherogenic factors : Using primary culture system of vascular smooth muscle cells(VSMCs) maintaining a differentiated phenotype, we demonstrated that epiregulin was released from VSMCs primed by atherogenic factors and acts as a major autocrine/paracrine factor for the progression of atherosclerosis (Circulation. 2003 18;108:2524-9.). 3,In vivo effect of unsaturated-LPA o … More n the atherogenesis. We demonstrated that treatment of rat common carotid arteries(CCAs) with 18:1 but not 18:0 LPA potently induced neointimal formation and that the coordinated activation of the ERK and p38MAPK pathways in the CCAs was critical for the 18:1 LPA-induced vascular remodeling in vivo (Circulation.2003 108:1746-52.). 3,Elucidation of the intracellular signal transduction involved in the pathogenesis of atherosclerosis : We demonstrated that IGF-I activated a protein-tyrosine phosphatase, SHP-2 in differentiated VSMCs and that the activated SHP-2 then dephosphorylated insulin receptor substrate-1(IRS-1), resulting in blockade of the activation of the ERK and p38MAPK pathways which are critically involved in de-differentiation of VSMCs. The results indicate that the IRS-1/SHP-2 interaction acts as a switch controlling phenotypic modulation of VSMCs (J.Biol.Chem.2004 279:40807-40818.). 4,Generation of atherosclerotic mouse : We have generated the transgenic mouse over-expressing the enzyme involved in the lipid synthesis, which is expected to have a disorder in the lipid metabolism. Less