PROPERTIES OF THE INTIMAL SMOOTH MUSCLE CELL

这是对人类动脉粥样硬化组织的研究。 我们已经表明，这种病变的细胞特征是内膜中平滑肌细胞的克隆性扩增。 本研究将通过分子生物学研究来解决这种克隆扩增的机制，通过在病变形成的时间过程中表征x-连锁异等位基因标记来寻找克隆性的时间过程。同样，我们将使用差异克隆方法来寻找区分这些内膜细胞的标记物，我们将使用来自人类病变的培养细胞来探索凋亡选择的可能机制。这项建议的总体目标是探索区分斑块平滑肌细胞和正常中膜平滑肌的特性。 这一目标源于三个简单的事实：（1）内膜由内膜平滑肌细胞的性质定义;（2）动脉粥样硬化是动脉内膜的局灶性疾病;（3）动脉粥样硬化病变的细胞包括克隆。具体目标是：（1）确定单克隆性的时间进程;（2）确定体外是否发生克隆扩增;（3）确定标记斑块平滑肌细胞的内膜独特基因;（4）检查细胞死亡在动脉粥样硬化进展部位的内膜扩张和中膜损失中的相对作用;和（5）寻找可赋予斑块平滑肌细胞增殖或抗凋亡优势的突变或遗传不稳定性。

This is a study of human atherosclerotic tissue. We have shown that the cells characterizing such lesion result from a clonal expansion of smooth muscle cells existing in the intima. This study will address the mechanism of this clonal expansion by molecular biologic studies looking for the time course of clonality by characterizing on x-linked heteroallellic marker over the time course of lesion formation. Similarly we will use differential cloning methods to look for markers that distinguish these intimal cells and we will use cultured cells from human lesions to explore possible mechanisms of apoptotic selection. The overall objective of this proposal is to explore the properties that distinguish plaque smooth muscle cells from normal medial smooth muscle. This objective grows out of three simple facts: (1) the intima is defined by the properties of the intimal smooth muscle cell; (2) atherosclerosis is a focal disease of the arterial intima, and (3) the cells of the atherosclerotic lesion comprise a clone. The Specific Aims are: (1) to determine the time course of monoclonality; (2) to determine whether clonal expansion occurs in vitro; (3) to define intimal-unique genes that mark the plaque smooth muscle cell; (4) to examine the relative role of cell death in expansion of the intima and loss of the media at sites of atherosclerotic progression; and (5) to look for mutations or genetic instability that could confer a proliferative or anti-apoptotic advantage on plaque smooth muscle cells.