ROLE OF M-CSF IN THE PATHOGENESIS OF ATHEROSCLEROSIS

巨噬细胞(MO)-集落刺激因子(M-CSF) 有助于动脉粥样硬化病变的发展。我们发现， 动脉粥样硬化易感载脂蛋白E和载脂蛋白E缺乏M-CSF 低密度脂蛋白受体(LDLR)缺陷小鼠导致 尽管高胆固醇血症加重，但动脉粥样硬化显著减轻。 我们最新的研究提供了令人信服的证据，支持直接的本地 巨噬细胞集落刺激因子在血管壁的作用。这些进步，加上 巨噬细胞集落刺激因子诱导尿激酶型纤溶酶原的特性 激活物(UPA)和基质金属蛋白酶(MMPs)级联促使更多 关于导致全系列疾病的分子机制的精细问题 M-CSF在病变血管壁上的作用。在这项提案中，我们寻求延长 我们的研究努力了解M-CSF在发育和发育过程中的作用 通过以下三个假设测试动脉病变的破裂：1) 巨噬细胞集落刺激因子对内膜MO和SMC的多向性作用主要通过 RAS介导的细胞信号转导下游核因子的激活 小路。其中一个这样的因子是转录因子Ets-2，它能促进细胞 增殖与生存，2)动脉粥样硬化M-CSF活性升高 病变通过上调血管内皮细胞膜上皮细胞数参与MO介导的基质重塑 尿激酶型纤溶酶原激活物和基质金属蛋白酶基因的表达。巨噬细胞集落刺激因子的这种作用可能在 斑块破裂；3)M-CSF上调MO特异性转录 通过激活一组共同的反式作用因子(如 作为转录因子家族)与AP-L形成三元复合体 并与存在于5‘调控区的顺式作用DNA元件结合 这些基因。其具体目的是：1)研究M-CSF对血管紧张素转换酶的影响 缺乏M-CSF的小鼠体内动脉病变相关细胞的生长 和/或apoE，并使用培养的细胞进行体外研究 巨噬细胞集落刺激因子缺陷小鼠：确定巨噬细胞集落刺激因子的机制(S) 介导的MO和SMC的增殖和存活，2)测定其作用 巨噬细胞集落刺激因子对体外培养的巨噬细胞uPA和MT3-MMPs表达的影响 巨噬细胞集落刺激因子调节uPA和MT3-MMP的产生与血管内皮细胞病变的关系 动脉粥样硬化病变的特征，以及3)识别顺式作用 尿激酶型纤溶酶原激活剂和MT3-基质金属蛋白酶启动子中的元件 M-CSF对这些基因表达的影响及信号转导事件的检测 将巨噬细胞集落刺激因子与uPA和MT3-MMP核调节分子连接。我们相信我们的 研究将提供有关M-CSF作用的新的重要信息 在动脉粥样硬化和增殖性血管的发展和破坏中 损害和这一信息可能被证明是有用的设计新的治疗方法 对血管疾病的干预。

Macrophage(MO)-colony stimulating factor (M-CSF) importantly contributes to the development of atherosclerotic lesions. We have found that the absence of M-CSF in atherosclerosis-prone apolipoprotein (apo) E or low-density lipoprotein receptor (LDLR)- deficient mice results in substantially reduced atherosclerosis despite augmented hypercholesterolemia. Our most recent studies provide compelling evidence in favor of a direct local effect of M-CSF within the vessel wall. These advances, together with the characterization of the M-CSF-mediated induction of urokinase plasminogen activator (uPA) and matrix metalloproteinases (MMPs) cascade have prompted more refined questions on the molecular mechanisms responsible for the full range of M-CSF actions in the diseased vessel wall. In this proposal, we seek to extend our research efforts to understand the role of M-CSF in the development and disruption of arterial lesions by testing following three hypotheses: 1) pleiotropic effects of M-CSF on intimal MO and SMC are modulated mainly through the activation of nuclear factors downstream to the Ras-mediated cell signaling pathways. One such factor is the transcription factor Ets-2 that promotes cell proliferation and survival, 2) increased M-CSF activity in atherosclerotic lesions contributes to the MO -mediated matrix remodeling by up regulating the expression of uPA and MT3-MMP genes. This effect of M-CSF may play a role in plaque disruption, and 3) M-CSF up regulates the MO-specific transcription of uPA and MT3-MMP genes by activating a common set of trans-acting factors (such as Ets family of transcription factors) that form ternary complexes with AP-l and bind to cis-acting DNA elements present in the 5' regulatory region of these genes. The specific aims are: 1) to investigate the effects of M-CSF on the growth of arterial lesion-associated cells in vivo using mice lacking M-CSF and/or apoE and to perform in vitro studies using cultured cells from M-CSF-deficient mice to determine the mechanism(s) underlying the M-CSF mediated proliferation and survival of MO and SMC, 2) to determine the effects of M-CSF on the expression of uPA and MT3-MMP in cultured MO and to examine the association of M-CSF regulated production of uPA and MT3-MMP to alterations in the character of atherosclerotic lesions, and 3) to identify the cis-acting elements in the uPA and MT3-MMP promoters that mediate the inductive effects of M-CSF on the expression of these genes and to examine the signaling events connecting M-CSF with the nuclear regulators of uPA and MT3-MMP. We believe our studies will provide new and important information regarding the role of M-CSF in the development and disruption of atherosclerotic and proliferative vascular lesions and this information may prove useful in design of novel therapeutic interventions for vascular diseases.