Molecular mechanisms of enhanced vascular smooth muscle cell growth in diabetes

导致T2 DM再狭窄增加的分子机制尚不清楚。血管通畅 肌细胞(VSMC)增殖在血管损伤后再狭窄中起关键作用，而葡萄糖、胰岛素、 氧化应激可促进VSMC生长。此外，在T2 DM的动物模型中， 损伤后VSMC的增殖反应。与白细胞12/15脂氧合酶(12LO)有关 作为促进动物损伤后VSMC增殖和新生内膜形成的关键介质 2型糖尿病模型的建立。我们的初步数据清楚地表明，12LO调节VSMC的生长，一 糖尿病患者对损伤反应加快的潜在机制。我们进一步证明了12LO诱导的 VSMC的增殖是由螺旋-环-螺旋转录因子ID3(VSMC的关键调节因子 胰岛素和葡萄糖介导的基因转录)。我们已经在多种型号的胰岛素中进行了演示 耐药和2型DM时，ID3的表达明显增加。机械学研究表明 Id3促进G1-S转变，促进VSMC生长和Id3的磷酸化 丝氨酸5调节这一事件。在这一更新应用中，我们建议扩展我们的体外机制 研究结果和以前的体内表达研究表明，12LO/LD3通路是一个关键的调节因子 研究2型糖尿病动物模型体内血管对损伤的反应。此外，我们建议 确定介导12LO诱导的ID3表达增加的顺式和反式作用元件 并在体内证实其在T2 DM损伤反应中的作用。 假说：2型糖尿病通过调节ID3的表达和表达调节血管损伤的反应 活动和VSMC增长。这种作用是由12LO诱导的核因子表达介导的，导致 增强ID3的表达和/或ID3的丝氨酸5磷酸化。将我们令人兴奋的发现从 VSMC培养在2型糖尿病血管损伤动物模型中的体内研究 中心假设，我们提出了以下目标。目标1：确定ID3在 在饮食诱导的2型糖尿病小鼠模型中，对损伤的反应加速了新生内膜的形成。 目的2：在体内评价12LO/LD3通路促进VSMC生长和病变形成的作用。 目标3c。扩大体外研究结果以证实ID3启动子中的12LO反应元件 培养中的ID3转录所需要的也调节体内的ID3转录，以响应T2 DM的损伤。

The molecular mechanisms that lead to increased restenosis in T2DM are unknown. Vascular smooth muscle cell (VSMC) proliferation plays a key role in restenosis following vascular injury, and glucose, insulin, and oxidative stress increase VSMC growth. Moreover, in animal models of T2DM, there is increased VSMC proliferation in response to injury. Leukocyte type 12/15 lipoxygenase (12LO) has been implicated as a key mediator of enhanced VSMC proliferation and neointimal formation in response to injury in animal models of T2DM. Our preliminary data clearly demonstrates that 12LO regulates VSMC growth, one potential mechanism for the accelerated response to injury in diabetes. We further demonstrate that 12LO-induced proliferation of VSMC is mediated by the helix-loop-helix transcription factor Id3 (a key regulator of insulin and glucose mediated gene transcription). We have demonstrated in multiple models of insulin resistance and type 2 DM, that Id3 expression is significantly increased. Mechanistic studies demonstrate that Id3 promotes G1-S transition leading to increased VSMC growth and that phosphorylation of Id3 on serine 5 regulates this event. In this renewal application, we propose to extend our in vitro mechanistic findings and previous in vivo expression studies to demonstrate that the 12LO/ld3 pathway is a key mediator of the vascular response to injury in vivo in animals models of type 2 DM. Furthermore, we propose to identify the cis and trans-acting elements that mediate 12LO-induced increases in Id3 expression and VSMC growth and confirm their role in vivo in the response to injury in T2DM . Hypotheses: Type 2 DM modulates the response to vascular injury via regulation of Id3 expression and activity and VSMC growth. This effect is mediated by 12LO-induced nuclear factor expression leading to enhanced Id3 expression and/or serine 5 phosphorylation of Id3. To extend our exciting findings from VSMC culture studies in vivo in an animals model of vascular response to injury in T2DM and to address this central hypothesis, we propose the following aims. Aim 1: Establish the essential role of Id3 in the accelerated neointimal formation in response to injury in diet-induced mouse models of type 2 DM. Aim 2: Evaluate in vivo the 12LO/ld3 pathway leading to accelerated VSMC growth and lesion formation. Aim 3c. Extend in vitro findings in vivo to confirm that the 12LO-response elements in the Id3 promoter required for Id3 transcription in culture also regulate Id3 transcription in vivo in response to injury in T2DM.