mDia1和Src在晚期糖基化终产物致血管通透性升高中的作用

AGE is found to play an important role in the development of diabetes, where level of AGE is correlated with the severity of microvascular dysfunction in diabetes complications. AGE and receptor for AGE (RAGE) signaling exert complex effects on cellular functions via complicated transduction pathways in endothelial cells (ECs). Our previous study has demonstrated that AGEs significantly altered endothelial F-actin cytoskeleton morphology and increased EC monolayer permeability. By utilizing EC monolayer and AGE induced diabetes mice model, we find that mDia1 and Src are involved in microvascular hyperpermeability induced by AGE. Based on the results, we assume that AGE binding to RAGE can promote oxidative stress through mDia1 activation, followed by Src phosphorylation. By promotion cell-cell junction disassembly and stress fiber formation, activated Src could lead to microvascular barrier dysfunction. We aim to explor the effect and signal mechanism of mDia1 and Src in microvascular endothelial barrier function, through a series of techniques including RAGE knockout mice model, primary endothelial cell culture, siRNA, endothelial monolayer permeability assay, and venual permeability assay, et al. The mechanism of microvascular hyperpermeability induced by AGE can provide therapy target for prevention and cure of microvascular dysfunction in diabetes.

糖尿病发病率越来愈高，晚期糖基化终产物引发的微血管病变在糖尿病并发症中起了重要的作用，探索其机制意义重大。我们前期工作已经证实AGE与RAGE结合后引起细胞骨架改变以及单层内皮细胞通透性增高，运用单层内皮细胞以及整体动物模型初步证实了mDia1和Src参与了晚期糖基化终产物介导的内皮细胞通透性的增高。据此提出AGE与RAGE结合后通过mDia1引发氧化应激，进而促使Src活化，后者则可通过破坏细胞间连接以及介导应力纤维生成来诱导内皮细胞通透性增高的假说。拟进一步利用RAGE敲基因小鼠,原代内皮细胞培养， siRNA，单层内皮细胞通透性及在体微血管通透性等多种手段，从分子，细胞，组织和整体模型层面对mDia1和Src在AGE致微血管屏障功能障碍中的作用机制，以及相应的作用靶点和信号通路进行深入研究，为进一步干预其作用靶点和信号通路，减轻和治疗糖尿病微血管病变提供研究基础。

糖尿病发病率越来愈高，晚期糖基化终产物引发的微血管病变在糖尿病并发症中起了重要的作用，探索其机制意义重大。我们前期工作已经证实AGE与RAGE结合后引起细胞骨架改变以及单层内皮细胞通透性增高，运用单层内皮细胞以及整体动物模型初步证实了mDia1和Src参与了晚期糖基化终产物介导的内皮细胞通透性的增高。据此提出AGE与RAGE结合后通过mDia1引发氧化应激，进而促使Src活化，后者则可通过破坏细胞间连接以及介导应力纤维生成来诱导内皮细胞通透性增高的假说。本研究利用RAGE敲基因小鼠,原代内皮细胞培养，siRNA，单层内皮细胞通透性及在体微血管通透性等多种手段，从分子，细胞，组织和整体模型层面对mDia1和Src在AGE致微血管屏障功能障碍中的作用机制，以及相应的作用靶点和信号通路进行深入研究。证明了AGEs通过其受体RAGE 结合，引发细胞内信号转导。RAGE胞内段与mDia1结合，可使后者活化，并引发Nox4向细胞膜移位，引发氧化应激。大量的活性氧生成则使Src磷酸化，进而导致VE-cadherin磷酸化并向细胞内移位，破坏了细胞间的连结。同时活化的Src又可通过moesin及FAK磷酸化，共同介导了内皮细胞通透性的增高。本研究深入探讨了AGEs在糖尿病所致微血管病变中的具体作用机制，为临床治疗糖尿病微血管病提供了理论依据。