ROLE OF M-CSF IN THE PATHOGENESIS OF ATHEROSCLEROSIS

巨噬细胞集落刺激因子（M-CSF） 有助于动脉粥样硬化病变的发展。我们发现 在动脉粥样硬化倾向载脂蛋白E或 低密度脂蛋白受体（LDLR）缺陷小鼠导致 显著降低动脉粥样硬化，尽管增加高胆固醇血症。 我们最近的研究提供了令人信服的证据，支持直接的局部 M-CSF在血管壁内的作用。这些进步，加上 M-CSF介导的尿激酶纤溶酶原诱导的表征 激活剂（uPA）和基质金属蛋白酶（MMPs）级联反应促使更多 关于负责全范围的分子机制的精确问题 M-CSF在病变血管壁中的作用。在这一建议中，我们寻求扩大 我们的研究努力，以了解M-CSF在发展中的作用， 通过测试以下三个假设来破坏动脉病变：1） M-CSF对内膜MO和SMC的多效性作用主要通过 Ras介导的细胞信号传导下游的核因子的激活 途径。一种这样的因子是转录因子Ets-2，其促进细胞增殖， 增殖和存活，2）增加的M-CSF活性在动脉粥样硬化 损伤通过上调细胞因子的表达，促进MO介导的基质重塑。 uPA和MT3-MMP基因的表达。M-CSF的这种作用可能在 斑块破坏，和3）M-CSF上调MO特异性转录 uPA和MT3-MMP基因通过激活一组共同的反式作用因子（如 作为转录因子的Ets家族）与AP-1形成三元复合物 并结合存在于5'调控区的顺式作用DNA元件， 这些基因。具体目的是：1）研究M-CSF对人肝癌细胞的作用， 使用缺乏M-CSF的小鼠体内动脉病变相关细胞的生长 和/或apoE，并使用来自 M-CSF缺陷小鼠，以确定M-CSF 介导的MO和SMC的增殖和存活，2）以确定 M-CSF对MO中uPA和MT3-MMP表达的影响， M-CSF调节的uPA和MT3-MMP的产生与 动脉粥样硬化病变的特征，以及3）确定顺式作用 uPA和MT3-MMP启动子中介导以下诱导效应的元件： M-CSF对这些基因表达的影响，并检查信号事件 将M-CSF与uPA和MT3-MMP的核调节剂连接。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 在动脉粥样硬化和血管增生的发展和破坏中， 这些信息可能有助于设计新的治疗方法， 血管疾病的干预措施。

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.