Histone deacetylase 7 and its interacting proteins in endothelial cells

描述(申请人提供)：HDAC7是IIa类HDACs的成员，与包括肌细胞因子2(MEF2)在内的转录因子相关，以抑制靶基因的表达。我们发现HDAC7与PML(早幼粒细胞白血病蛋白)相互作用。最近在小鼠身上的研究表明，HDAC7和PML在内皮细胞(ECs)的正常发育中起着关键作用。HDAC7和PML之间的关系是复杂的。最重要的是，HDAC7与PML的结合导致HDAC7靶基因的去抑制，具有明显的生物学后果，例如在内皮细胞中HDAC7靶基因的表达改变。HDAC7和PML的相互作用也控制着PML的SUMO基化和PML NB的形成。所有这些影响将在机制水平上进行研究，重点是内皮细胞及其对炎性刺激的反应。其具体目的是：1)阐明TNF1诱导PML mRNA和蛋白水平积聚的机制。我们将使用化学抑制剂、siRNA和显性-负表达策略来描述控制TNF1诱导的PML mRNA积累、蛋白水平、PML总和作用以及PML NBS形成的机制。2)探讨HDAC7介导TNF1诱导的单核细胞趋化蛋白-1转录的机制。我们假设，TNF1诱导PML NBS隔离物HDAC7的形成，导致基质金属蛋白酶-10和单核细胞趋化蛋白-1的表达下调，这两个蛋白都是HDAC7的靶标。我们将使用染色质免疫沉淀(CHIP)、siRNA敲除和瞬时转染报告实验来测试我们的模型，以表征MCP-1启动子。我们还有兴趣确定在TNF1处理后，MCP-1启动子上的组蛋白修饰是否发生变化。我们将同时剖析PML和TNF1在内皮细胞中的作用。我们将通过体外和体内方法剖析PML在TNF1介导的血管黏附、迁移、增殖、凋亡和血管重塑中的作用。综上所述，我们提出的研究旨在剖析细胞因子介导的EC激活的机制和识别效应器。了解控制炎症、增殖、细胞凋亡和血管生成的途径可能对治疗血管疾病具有治疗意义。

DESCRIPTION (provided by applicant): HDAC7 is a member of the class IIa HDACs that associate with transcription factors including myocyte factor 2 (MEF2) to repress expression of target genes. We show that HDAC7 interacts with PML (promyelocytic leukemia protein). Recent studies in mice have demonstrated a critical role for HDAC7 and PML in the normal development of endothelial cells (ECs). The relationship between HDAC7 and PML is complex. Of primary importance is that the binding of HDAC7 to PML leads to derepression of HDAC7 target genes with clear biological consequences such as altered expression of HDAC7 target genes in the case of endothelial cells. The interaction of HDAC7 and PML also controls the level of PML sumoylation and PML NB formation. All of these effects will be investigated at the mechanistic level with a focus on endothelial cells and their responses to inflammatory stimuli. The specific aims are: 1) To elucidate the mechanisms underlying TNF1-induced accumulation of PML mRNA and protein levels. We will employ chemical inhibitors, siRNA, and dominant-negative expression strategies to delineate the mechanisms controlling TNF1-induced accumulation of PML mRNA, protein levels, PML sumoylation, and formation of PML NBs. 2) To investigate the mechanisms by which HDAC7 mediates TNF1-induced MCP-1 transcription. We hypothesize that TNF1-induced formation of PML NBs sequesters HDAC7, leading to derepression of MMP-10 and MCP-1, both of which are targets of HDAC7. We will test our model using chromatin immunoprecipitation (ChIP), knockdown by siRNA, and transient transfection reporter assays to characterize the MCP-1 promoter. We are also interested in determining whether changes in the histone modifications occur at the MCP-1 promoter upon TNF1 treatment. We will simultane3) To dissect the role of PML and TNF1 in ECs. We will dissect the roles of PML in TNF1-mediated adhesion, migration, proliferation, apoptosis, and remodeling of blood vessels using in vitro and in vivo approaches. In summary, our proposed study is aimed at dissecting the mechanisms and identifying the effectors in cytokine-mediated EC activation. Understanding the pathways that control inflammation, proliferation, apoptosis, and angiogenesis may have therapeutic implications for treating vascular diseases.