氧化应激诱导血管发生微环境中Fibronectin组装异常的机制研究

Vasculogenesis plays an important role in development as well as cardiovascular disease, and one of the major causes of disruption of vasculogenesis is oxidative stress. Exracellular matrix (ECM) along with vascular endothelial cells (VEC) and secreted cytokines/chemokines are the key components in the construction of vasculogenesis microenvironment. However, it is still elusive how oxidative stress induced the abnormity of ECM assembly during vasculogenesis. As epidemiological studies indicate that cigarette smoking is a strong inducer for the abnormalties of vasculogenesis, we utilized the zebrafish model and examined the effect of the cigarette smoke extracts (CSE) on the vascular endothelial cells in our preliminary experiment. We found that CSE could induce increasing deposition and aberrant assembly of Fibronection (FN) in VEC during embryonic stage. Interestingly，we observed the expression of NRF2, one of the key determinators involving of oxidative stress, was significantly increased. Moreover, the expression of the pivotal genes which regulated FN assembly, such as STAT3 and EFE, were changed as well. Based on these observations, we propose to investigate whether oxidative stress induced by CSE could disturb the ECM of vasculogenesis microenvironment by employing zebrafish and human umbilical vein endothelial cells. We will elucidate the molecular mechanism of how the regulation of NRF2 on STAT3 mediated the process that oxidative stress affects the ECM assembly. The studies of the regulatory mechanism and related pathways could help us better understand the vasculogenesis microenvironment and the pathogenesis of cardiovascular disease induced by cigarette, and provide a potential avenue for treatment.

血管发生在机体发育及心血管疾病等过程中有重要作用，氧化应激是血管发生异常的关键因素之一。血管内皮细胞、胞外基质和细胞因子等共同组成了血管发生的微环境，但是氧化应激对于微环境中胞外基质的影响及具体作用机制仍不清楚。流行病学证据表明吸烟能够引起血管发生异常，最近我们发现烟气干扰斑马鱼血管内皮细胞胞外基质Fibronectin组装，并能诱导氧化应激相关转录因子NRF2和下游STAT3表达改变，而且我们之前的文章已证明STAT3与胞外基质组装密切相关。因此，在本项目中我们使用斑马鱼和人血管内皮细胞为研究对象，以烟气诱导内皮细胞氧化应激从而干扰胞外基质Fibronectin组装的作用机制为核心，重点研究氧化应激如何影响胞外基质组装，特别是NRF2调节STAT3信号通路在其中的作用，进一步揭示吸烟扰乱血管发生微环境的分子机制，更全面的理解血管发生过程，为相关疾病的治疗提供重要的理论依据。

血管发生在机体发育及心血管疾病等过程中有重要作用，氧化应激是血管发生异常的关键因素之一。NRF2作为非常重要的抗氧化因子，可通过调控下游多种抗氧化基因的表达维持正常的氧化还原稳态，保护心血管系统免受氧化应激的影响。然而，近些年的研究也报道NRF2的激活会引起心血管系统的异常，但是相关机制还有待研究。这些结果提示我们深入理解NRF2在血管发生过程中所扮演的角色具有重要的意义。以往的研究显示卷烟烟气能够诱导氧化应激引起心血管疾病。在本项目中，我们使用烟气提取物处理人血管内皮细胞和斑马鱼胚胎，结果显示烟气所诱导的氧化应激反应能够引起血管发生异常。进一步研究发现，氧化应激激活NRF2可在转录水平促进STAT3的表达，而STAT3是FN组装过程中重要的调控基因，其过表达导致了血管内皮细胞周围FN的异常组装。使用NRF2或STAT3的抑制剂能够恢复烟气提取物诱导的FN异常组装，从而恢复血管的正常形成。综上所述，我们的研究揭示了NRF2在血管形成过程中的新的作用，在发挥抗氧化功能的同时，也能够干扰血管内皮细胞周围胞外基质的组装从而影响血管发生。这些发现将加深研究者们对于NRF2功能和血管发生过程的理解，同时也有助于以NRF2为靶点的治疗策略的开发与优化。

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