Alarmin 分子HMGB1在糖尿病视网膜病变中的信号转导机制研究

Diabetic retinopathy (DR) is the leading cause of blindness in the working age people worldwide, mainly because of the lack of effective treatment due to unknown pathogenesis of DR. It has been confirmed that para-inflammation plays an important role in DR pathogenesis, meanwhile the alarmin molecule HMGB1 (high mobility group box-1 protein) is involved in para-inflammation. Our latest studies have revealed that HMGB1 was elevated significantly in aqueous humor and peripheral blood of patients with DR and in diabetic rat retinas，when compared to their respective normal counterparts. Nevertheless, the specific role and mechanism of HMGB1 in DR are unclear. Therefore, this project is designed firstly to determine the expression and discrepancy of HMGB1 and inflammation-related factors in aqueous humor and peripheral blood between DR patients and normal controls，by performing ELISA and qRT-PCR methods. Secondly to evaluate the effect of HMGB1 on the development and progression of DR in SD rats with the use of siRNA interference and electroretinogram techniques. Thirdly to investigate the signal transduction mechanism of HMGB1 involved in DR by corresponding experiments with neutralizing antibodies and viral transfection approaches in human retinal cells. This project is aimed to clarify the relationship between HMGB1, inflammation-related factors and the severity of DR, and to unveil the specific role and exact mechanism of HMGB1 participating in DR, consequently to achieve a novel breakthrough for studies on DR pathogenesis, prevention and treatment.

糖尿病视网膜病变（DR）是全世界成人盲目的主要原因，因发病机制不明而缺乏有效的治疗手段。已知慢性低度炎症在DR发病机制中起重要作用， Alarmin分子HMGB1（高迁移率族蛋白B1）与慢性低度炎症有关。最近我们研究发现HMGB1在DR患者房水及糖尿病大鼠视网膜中较正常对照组显著增加，但HMGB1在DR中的具体作用及其机制尚不清楚。为此，本研究拟采用：（1）ELISA、qRT-PCR等方法在房水及外周血中探讨DR患者与正常人HMGB1及炎症相关因子的表达及其差异（2）siRNA干扰、视网膜电生理等技术在SD大鼠中探讨HMGB1对DR发生发展的影响（3）中和抗体、病毒转染等方法在人视网膜细胞中探讨HMGB1参与DR的信号转导机制，试图阐明HMGB1及其信号通路产生的炎症相关因子与DR严重程度的相关性，确定出HMGB1在DR中的具体作用及其确切机制，为DR的发病机理及防治研究找到新的突破。

糖尿病视网膜病变（DR）是全世界成人低视力和致盲的主要原因，因发病机制不明而缺乏有效的治疗手段。最近我们研究发现Alarmin分子HMGB1（高迁移率族蛋白B1）与DR慢性低度炎症有关，但HMGB1作用的信号转导机制尚不清楚。本研究探讨了HMGB1与DR的相关性及其参与DR信号转导的分子机制。主要研究发现：高糖可以刺激ARPE-19细胞上HMGB1及其相关受体表达的增加，使用anti-HMGB1抗体处理能显著抑制ARPE-19细胞内NF-kB p65、TNF-α及VEGF的表达有上调作用；在DR大鼠模型中，HMGB1在视网膜中的表达明显增加，并且能通过结合RAGE、TLR2及TLR4受体激活NF-kB p65及其下游相关炎症信号组分；在OIR大鼠模型中，刺激TLR3能激活NF-kB p65及其炎症因子IL-6、TNF-α的表达，而局部抑制TLR3的表达能下调相关炎症信号通路。根据最新研究进展，我们研究了阻断IL-23-Th17-IL-17A信号通路对DR大鼠模型的视网膜病变的影响,发现在DR大鼠外周血和视网膜中的IL-17A表达水平均增加，局部阻断IL-23能减少视网膜上IL-17A的表达，并改善DR大鼠的血-视网膜屏障。DR最新研究进展表明，炎症小体作为固有免疫的重要组成部分，参与了Toll样受体信号通路，其相互作用共同促进疾病的发展，我们评价了DR大鼠模型中视网膜NLRP3及其相关信号通路组分的表达情况及ResolvinD1对炎症小体通路影响发现ResolvinD1可以抑制炎症小体通路相关蛋白表达，可能对DR起保护作用。我们还检测了IL-27及IL-35在DR患者玻璃体液和血清中的表达水平。发现PDR患者血清中IL-27及IL-35表达水平较对照组患者降低，且PDR患者的玻璃体液中IL-35表达水平也低于对照组患者。这些研究结果为DR的防治提供了新的前景。