YY1 FUNCTIONS IN VASCULAR SMOOTH MUSCLE CELLS

YY1 在血管平滑肌细胞中的功能

• 批准号: 6498995
• 负责人: ANNY A USHEVA-SIMIDJIYSKA
• 金额: $ 29.42万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6498995
• 关键词: DNA replication; cell cycle; cell migration; cell proliferation; cytokine; gene expression; gene interaction; genetic mapping; genetic promoter element; genetic transcription; growth factor; human tissue; pathologic process; polymerase chain reaction; restenosis; southern blotting; transcription factor; tumor suppressor genes; vascular smooth muscle

The long term goals of this project are to elucidate the molecular mechanisms underlying the abnormal liferation and migration of vascular smooth muscle (VSM) cells that is induced by acute arterial injury and leads to restenosis. The striking morphological similarities between cells in restenosis injury and cancer cells suggest that many of the same mechanisms may be responsible for abnormal growth of both types of cells. We have recently obtained evidence that overexpression of the transcription factor Yin Yang 1(YY1) in G0/G1-arrested coronary artery smooth muscle cells (CASMC) activates DNA synthesis. In cells that overexpress both YY1 and Rb, however, level of DNA synthesis falls back to normal levels. We also found that in growth arrested CASMC a significant portion of YY1 is in a complex with Rb but not in S-phase cultures and that recombinant Rb physically, directly interacts with YY1, destabilizing YY1's interaction with DNA. Moreover we found that Rb inhibits YY1 dependent transcription in vitro. The preliminary data suggest that YY1 is an important downstream target of the Rb pathway in CASMC and that the interaction of Rb and YY1 is likely to be cell cycle specific in vivo. It suggests that, as part of a complex with Rb, YY1 may participate in checkpoint functions that regulate the transition from a contractile to a "proliferative" phenotype at the level of transcription. We hypothesize that overexpression of YY1 induced by inflammatory cytokines and growth factors and/or disruption of the interaction between Rb and YY1 may alter gene expression and perhaps even cause abnormal CASMC growth after arterial injury. The Specific Aims of this proposal are: 1.0. To characterize the Rb-YY1 interaction and the effect of the YY1-Rb interaction on YY1's transcription factor function in the context of cellular promoters. 2.0 to study the functional consequences of the deregulated expression of YY1 in human CASMC. At present, understanding of and potential strategies to prevent the abnormal growth and migration of VSM cells are directly extrapolated from knowledge obtained from other cell systems, particularly from cancer cells in which cell cycle checkpoints are abrogated and normal cell cycle progression is lost. Little if any experimental evidence is available elucidating the mechanisms by which VSM cells themselves escape from G0 arrest and begin active proliferation. Therefore, it is essential to define the molecular mechanisms of VSM cell proliferation before one can consider specific strategies to prevent restenosis.

该项目的长期目标是阐明由急性动脉损伤诱导的血管平滑肌（VSM）细胞异常寿命和迁移的分子机制，并导致恢复病。 再狭窄损伤和癌细胞中细胞之间的惊人形态相似性表明，许多相同的机制可能是两种细胞异常生长的原因。 我们最近获得了证据表明，转录因子阳阳1（yy1）的过表达在G0/G1捕获的冠状动脉平滑肌细胞（CASMC）中激活DNA合成。 然而，在过表达YY1和RB的细胞中，DNA合成水平恢复到正常水平。 我们还发现，在生长中，CASMC中的YY1的很大一部分与RB的复合物中，但在S期培养物中不存在，并且重组RB在物理上直接与YY1相互作用，使YY1与DNA的相互作用破坏了稳定。 此外，我们发现RB在体外抑制YY1依赖性转录。 初步数据表明，YY1是CASMC中RB途径的重要下游靶标，RB和YY1的相互作用可能是体内特异性细胞周期的相互作用。 它表明，作为与RB的复合物的一部分，YY1可以参与检查点功能，该功能调节转录水平上从收缩到“增殖”表型的过渡。 我们假设由炎症细胞因子和生长因子和/或RB和YY1之间的相互作用破坏YY1的过表达可能会改变基因表达，甚至可能导致动脉损伤后CASMC生长异常。 该提案的具体目的是：1.0。在细胞启动子的背景下，表征RB-YY1相互作用以及YY1-RB相互作用对YY1转录因子功能的影响。 2.0研究人类CASMC中YY1表达不受调节的表达的功能后果。目前，对预防VSM细胞异常生长和迁移的潜在策略的理解直接从其他细胞系统获得的知识中直接推断出来，尤其是从消除细胞周期检查点并丢失正常细胞周期进展的癌细胞中。 几乎没有任何实验证据可以阐明VSM细胞本身从G0停滞中逃脱并开始主动增殖的机制。 因此，在人们可以考虑预防再狭窄的特定策略之前，必须定义VSM细胞增殖的分子机制。