基于EPOR-ERK信号通路探讨EPO干预早产儿脑白质损伤中血管新生的机制

Periventricular white matter damage（PWMD）is easy to cerebral palsy. Yet, no targeted therapy for PWMD is presently available. Recently, it has been reported that erythropoietin (EPO) has neuroprotection in adults. Our research also confirmed that EPO has protection effect to the PWMD model mouse. However， its mechanism is unclear. Our previously study revealed that EPO increased the angiogenesis， EPO receptor (EPOR) and phosphorylated ERK in experimental rat models of PWMD. But，the angiogenesis was affected after using the ERK inhibitors. Accordingly，we suggest that EPO binding of EPOR, which results in activation and phosphorylation ERK. It maybe mediates angiogenesis through this signal channels. We will analysis expression of key proteins EPOR and ERK after EPO intervention. And adopting overexpression/knock down strategies in vitro and inhibit strategies in vivo, we intend to explicit the changes of EPOR and ERK and each of them respectively control the upstream and downstream key role in signaling pathways of EPO to regulate angiogenesis. So far, there is no report of the mechanism of EPO regulate angiogenesis in premature PWMD. And it may provide new clues of neuroprotection for EPO, especially in EPO treatment of premature PWMD.

早产儿脑室周围白质损伤（PWMD）易致脑瘫，目前尚无有效防治方法。近年发现促红细胞生成素（EPO）在成人神经系统具有保护功能，我们研究发现：EPO对早产儿PWMD模型鼠脑也有很好保护作用，且EPO干预后增加了鼠受损脑组织区血管新生反应、EPO受体（EPOR）和磷酸化的ERK表达水平，运用ERK抑制剂则血管新生反应减少。据此，我们提出EPO与EPOR作用后激活下游ERK信号通路，可能通过这一信号途径调控血管新生。本研究拟：从体外到体内分析信号通路关键蛋白EPOR和ERK在EPO干预后的时空表达规律；以基因过表达/沉默技术、蛋白抑制技术等在内皮祖细胞、早产儿PWMD模型鼠中探讨EPOR和ERK在EPO调控血管新生中的上下游关键位置，论证EPO通过EPOR-ERK信号通路调控血管新生的分子机制。本研究将为阐明EPO在早产儿PWMD中的神经保护机制提供新线索，为临床防治早产儿PWMD提供理论依据。

早产儿脑室周围白质损伤（PWMD）易导致脑瘫，目前尚无有效防治方法。近年发现促红细胞生成素（EPO）具有神经系统保护功能。研究拟分析信号通路关键蛋白EPOR和ERK在EPO干预后的时空表达规律；并以蛋白抑制技术,在早产儿PWMD模型鼠中探讨EPOR和ERK在EPO调控血管新生中的上下游关键位置，探索EPO调控血管新生的分子机制。研究结果显示：EPOR在EPO干预后表达略有提高，但是ERK未见明显改变，同时磷酸化的EPOR和磷酸化的ERK表达则在EPO干预后不同时间点都有明显升高，提示EPO干预后改变了通路蛋白的磷酸化发挥脑保护作用；通过对EPOR阻断，结果显示磷酸化的EPOR和磷酸化的ERK表达均下降，同时血管形成相关蛋白CD34和VEGFR2表达也下调，提示EPO干预的上游靶点为EPOR；而对ERK的阻断，则发现磷酸化的ERK表达下降但磷酸化的EPOR无明显改变，血管形成相关蛋白CD34和VEGFR2表达也下调，提示EPO干预的下游靶点为ERK。该研究阐明了EPO在早产儿PWMD中的神经保护机制。本研究还拓展探索了早产儿PWMD模型中基因表达的改变。结果发现，脑损伤后有显著的环状RNA的改变，为进一步研究EPO等药物干预靶点提供了新的思路和策略。