雌激素受体β在内皮祖细胞抗氧化应激损伤中的作用机制研究

Oxidative stress can inhibit the biological function of EPCs and affect angiogenesis, which is an important factor of chronic wound healing, while the detailed mechanism is still unknown. Our previous studies have shown that Overexpression of ERβ can induce SOD2 expression in vascular endothelial cells. It has been found that resveratrol can increase the expression of SOD2 by activating ERβ, and increase the expression of SOD2 by activating Nrf2. PI3K/Akt is an important signaling pathway for Nrf2 regulation, closely related to ERβ. Therefore, we hypothesized that ERβ increases the expression of SOD2 by PI3K/Akt/Nrf2 pathway is the key molecular mechanism for EPCs' anti-oxidative stress. This study intends to activate or inhibit ERβ, and interfere the expression of Nrf2 or overexpression of phosphorylation site mutation Nrf2. Then we detect the expression of SOD2 in EPCs, and clarify that ERβ can regulate the expression of SOD2 protein by activating Nrf2. We proposed to construct a PI3K constitutive activation lentiviral vector, and activate or inhibit the PI3K/Akt pathway. Then we observed the effect of ERβ on the activation of Nrf2 and the expression of SOD2. In order to prove that PI3K/Akt is an important signal pathway in the regulation. The effect of gene transfection on EPCs in chronic wound healing was verified by animal experiments, which provided new ideas for the treatment of chronic wound.

氧化应激使EPCs血管新生功能受抑是慢性创面愈合障碍的重要因素，其调节机制还不清楚。我们研究发现高表达ERβ可增加内皮细胞SOD2表达。不同研究发现白藜芦醇分别通过激活ERβ或Nrf2使SOD2表达增高，PI3K/Akt是Nrf2调控的重要信号通路，而且与ERβ密切相关。据此我们提出假设：ERβ通过PI3K/Akt/Nrf2途径使SOD2表达增高是EPCs抗氧化应激的关键分子机制。本研究拟激活或抑制ERβ后，干扰Nrf2表达或者高表达磷酸化位点突变Nrf2，检测EPCs中SOD2表达水平，明确ERβ通过激活Nrf2调节SOD2蛋白表达。构建构成型活化的PI3K激酶重组慢病毒载体，激活或者抑制PI3K/Akt通路后，观察ERβ对Nrf2活化和SOD2表达的影响，明确PI3K/Akt是其调控的重要信号通路。通过动物实验验证基因转染EPCs在慢性创面愈合中的作用，为慢性创面治疗提供新思路。

氧化应激使血管新生功能受抑是慢性创面愈合障碍的重要因素，其调节机制还不清楚。本研究通过建立高糖氧化应激细胞模型和糖尿病大鼠慢性创面模式，研究糖尿病慢性创面难愈的分子机制。研究发现高糖可以使ERβ和SOD2表达水平显著受抑，Nrf2活性显著下降，引起细胞氧化应激，进而导致细胞HIF1α/VEGF信号通路受抑制，这可能是糖尿病慢性创面难愈的重要原因。而ERβ/Nrf2/SOD2通路是调控细胞氧化应激的重要通路，其在糖尿病慢性创面愈合中发挥重要作用，ERβ/Nrf2/SOD2通路受抑是糖尿病创面难愈的重要调控机制。本研究通过阐明血管内皮细胞抗氧化损伤调控机制新的分子理论基础，为临床上减轻氧化应激损害、促进慢性创面愈合提供新的靶点和实验依据。