雌二醇抗TLRs介导的免疫炎性反应保护RNCs免受氧化应激损伤的机制研究

The decrease and loss of function of retinal nerve cells (RNCs) caused by the oxidative stress damage is a common way to eventually cause blindness. We found that the estradiol (E2) could protect the RNCs from the oxidative stress, and the expression of TLRs could also be suppressed, however, the specific mechanism is not clear. The new research suggests the activation of NF-κB and STAT3 signal pathways is associated with the suppressing of oxidative stress, in addition, the Dock3 has outstanding effect of protecting the nerve cells from damage. Therefore，we put forward the following hypothesis: “E2 can up-regulate the Dock3 and activate the NF-κB and STAT3 signal pathway thereby reducing the expression of the TLRs and their downstream pro-inflammatory cytokines, and then the immune inflammatory reaction was suppressed to protect the RNCs resistance to the oxidative stress.” In this project, we proposed to use the oxidative stress experimental model of rat retina, and mainly apply the following methods including RNA interference of TLRs and Dock3, the TLRs ligand stimulation and the activation detection of the NF-κB/STAT3 signal pathway to confirm our hypothesis. This study will provide the experimental data for revealing the effect and its mechanism of E2 neuroprotection from oxidative stress damage, and supply new ways and strategy for clinical prevention and treatment of the various degenerative diseases in central nervous system including the retina.

氧化应激损伤导致视网膜神经细胞（retinal nerve cells, RNCs）的减少和功能丧失是最终致盲的共同途径。我们发现，雌二醇（estradiol，E2）可抗氧化应激保护RNCs，并下调TLRs的表达，但具体机制不清。最新研究表明，NF-κB及STAT3信号的激活与细胞抗氧化应激相关，且Dock3在抑制神经损伤过程中作用突出。因此，我们提出以下假说：“E2可上调Dock3并激活NF-κB及STAT3信号,从而降低TLRs及其下游促炎因子的表达，抑制免疫炎性反应，抗氧化应激，保护RNCs。”我们拟通过RNCs氧化应激模型，应用Dock3及TLRs的RNA干扰，TLRs配体刺激，NF-κB及STAT3信号通路活化检测等方法来证实这一假说。本研究为E2神经保护作用及其机制的阐明提供实验数据，并为包括视网膜在内的多种中枢神经退行性疾病的临床预防及治疗提供新的途径和策略。

氧化应激损伤导致视网膜神经细胞的减少和功能丧失是导致相关视网膜疾病的重要因素。先前的实验研究中我们发现，雌二醇(17β-estradiol，E2)可抗氧化应激保护RNCs，并下调TLR2的表达，但具体机制不清。最新研究也表明，NF-κB及STAT3信号的激活与细胞抗氧化应激相关，且Dock3在抑制神经损伤过程中作用突出。通过本项实验研究我们发现，E2可降低TLR2及其下游促炎因子的表达，抑制免疫炎性反应并上调Dock3、NF-κB p65的表达及活化STAT3信号通路,从而保护视网膜神经细胞免受氧化应激所导致的凋亡损伤，增强视网膜细胞功能，抑制其形态学改变。本项研究中，我们通过建立体外H2O2及在体光照或高脂高糖诱导Ⅱ型糖尿病氧化应激损伤模型，应用TLR2的小分子RNA干扰，TLR2配体肽聚糖刺激，重要信号分子Dock3、NF-κB及STAT3信号通路活化检测等方法进一步研究E2抗氧化应激损伤的视网膜神经保护作用及其机制，最终为包括视网膜在内的多种中枢神经退行性疾病发病机制的阐明提供实验数据，为临床预防及治疗此类神经退行性疾病提供新的途径和策略。