OVGP1在血管重塑中的作用及其致高血压的功能机制研究

It is crucial to identify novel hypertension-associated genes. Our previous results from Genome-Wide Analysis of DNA Methylation indicated that OVGP1 may be associated with hypertension. OVGP1 promotes the expression of TGF-β1 and interacts with vascular remodeling genes such as FLOT1 and E-Cadherin, which may induce vascular remodeling and thus result in hypertension. Therefore, we speculate that OVGP1 may promote vascular remodeling and hypertension through regulation of TGF-β1 expression and/or interaction with FLOT1 and/or E-Cadherin. To investigate the role of OVGP1 on vascular remodeling and hypertension, the expression of vascular remodeling- and hypertension-associated genes together with related signaling pathways will be measured after OVGP1 overexpression or knockdown by using gene microarray, bioinformatics and molecular biology assays. The interaction among OVGP1, FLOT1 and E-Cadherin will be analyzed by using CoIP and immunofluorescence assays. Then, the effects of OVGP1 on proliferation, morphology, adhesion and migration of both HUVEC and HUASMC will be analyzed. At last, we will observe the effects of OVGP1 on vascular remodeling and blood pressure in vivo. The present study is started from epigenetic evidences and deeply investigates the mechanisms of OVGP1 on vascular remodeling and blood pressure regulation. Therefore, our study may provide novel evidences to epigenetic mechanisms on hypertension, and thus may explore novel therapeutic targets for hypertension.

鉴定高血压相关新基因十分重要，我们全基因组甲基化差异分析发现OVGP1可能与高血压相关，它能促进血管重塑相关基因TGF-β1表达，并与血管重构相关蛋白FLOT1和E-Cadherin相互作用。据此推测OVGP1可能通过调控TGF-β1或与FLOT1，E-Cadherin相互作用，促进血管重塑从而导致高血压。我们首先利用基因芯片、生物信息学及分子生物学方法分析OVGP1过表达或低表达后血管重塑、血压调节相关基因的表达改变及相关信号通路；利用CoIP，免疫荧光等技术验证分析OVGP1与FLOT1，E-Cadherin相互作用；然后分析OVGP1对血管内皮细胞和平滑肌细胞的增殖、形态、粘附和迁移的影响。最后在整体水平观察OVGP1对血管重塑及血压调节的作用。本研究从表观遗传学研究为切入点，深入探讨相关基因OVGP1的作用机制，有望为表观遗传参与高血压发病提供新证据，为高血压的防治提供新的靶点。

高血压是心血管疾病最重要的危险因素，高血压造成的靶器官损伤通常给患者本人乃至整个社会带来巨大负担。然而高血压是一种多基因病，其发病机制复杂，因此发现与高血压发病的相关新基因十分重要。我们前期研究发现OVGP1在极端高血压病人中甲基化程度降低，为探明OVGP1在高血压中的作用，本研究在高血压患者血浆中发现OVGP1的表达水平显著升高，在高血压小鼠模型中也观察到了类似的效果。通过转基因小鼠和敲除小鼠分别过表达和敲低OVGP1，采用遥测法及尾测法监测血压，发现过表达OVGP1后引起血压升高，敲低后抑制血压升高。通过股动脉损伤模型诱导内膜损伤后血管重塑，发现OVGP1在血管新生内膜中表达升高，过表达OVGP1促进内膜增厚，敲低后抑制血管损伤后内膜形成。在血管平滑肌细胞中采用PDGF-BB处理，发现OVGP1表达显著升高，同时-SMA表达降低。敲低OVGP1后抑制了PDGF-BB引起的表型转换。敲低OVGP1的表达可轻度激活ERK1/2。在给予PDGF-BB诱导的条件下，ERK1/2的磷酸化水平可显著升高，而敲低OVGP1表达后抑制ERK1/2的磷酸化水平。通过CCK8分析细胞的增殖活性，发现敲低OVGP1后抑制了PDGF-BB引起的细胞增殖，过表达OVGP1后促进了PDGF-BB引起的细胞增殖。由此可知，OVGP1很可能通过促进血管重塑而升高血压。通过本研究的开展，发现了新基因OVGP1对血压的影响及其分子机制，并为高血压的防治提供新线索。