HMGB2抑制糖尿病缺血后血管新生及机制研究

Angiogenic dysfunction occurs in diabetic patients with chronic total occlusion of coronary arteries, and the mechanisms behind remain not fully clarified. We collected tissue fluid across the occlusion sites of coronary arteries in diabetic patients with good or poor collateralization during PCI performance, followed by LC-MS/MS analysis. The results showed that HMGB2 level was significantly increased in tissue fluid and in serum from diabetic patients with poor collateralization than that from good collateralization. Injection of HMGB2 protein impaired angiogenesis in ischemic gastrocnemius of STZ-induced diabetic mice after femoral arterial ligation. Consistently, HMGB2 adversely affected tube formation in endothelial cells under hyperglycemic status. The mRNA array of HMGB2-treated hypoxic endothelial cells suggested that HMGB2 aggravated oxidative stress, and then inhibited Wnt/β-catenin pathway activity through upregulation of multiple adverse elements including -catenin, pigment epithelium-derived factor (PEDF), kallistatin, and Forkhead box O1 (FOXO1). Such impact caused angiogenic dysfunction in diabetic ischemic tissue, with aggravation of inflammation and apoptosis. However, HMGB2-induced effects were significantly attenuated by administration of ROS inhibitor apocynin. Combining with data of previous studies and our findings, we speculate that HMGB2-induced depression of Wnt/β-catenin pathway is a novel mechanism regarding lower extremity ischemia in diabetes. In our future study, we will test this hypothesis by establishing lower extremity ischemia models in mice of HMGB2-KO、HMGB2-Tg and controls, with using siRNA, apocynin or pathway inhibitors.

糖尿病时冠脉慢性闭塞后侧支形成不良，机制不明。我们收集糖尿病侧支形成好和差患者冠脉阻塞远端组织液，行质谱分析。发现并证实，侧支差者组织液和血清中HMGB2水平显著高于侧支好者。HMGB2局部注射抑制糖尿病小鼠下肢缺血后血管再生，也抑制高糖培养下内皮细胞成管效应。mRNA芯片检测发现并证实，糖尿病缺氧时HMGB2加剧氧化应激，经上调-catenin、PEDF、kallistatin等多途径抑制Wnt/-catenin通路，造成腓肠肌缺血后血管新生不良，加重炎症和凋亡；而ROS抑制剂逆转HMGB2致病效应。结合文献提示HMGB2作用方式为糖尿病缺血组织血管再生不良、预后差的新机制。后续研究将以HMGB2-KO、HMGB2-Tg小鼠，制作糖尿病下肢缺血模型，运用腺病毒、siRNA、ROS抑制剂等，阐明HMGB2经多途径下调Wnt/-catenin通路，抑制缺血组织血管再生和使预后不良机制。

糖尿病时冠脉慢性闭塞后侧支形成不良，机制不明。我们收集糖尿病侧支形成好和差患者的血清，行质谱分析。发现并证实，侧支差者血清中HMGB2水平显著高于侧支好者。HMGB2注射抑制小鼠下肢缺血后血管再生，也抑制高糖培养下内皮细胞成管效应。HMGB家族与细胞焦亡密切相关，我们发现并证实，HMGB2可以激活糖尿病小鼠体内或高糖培养下内皮细胞的细胞焦亡，造成腓肠肌缺血后血管新生不良。而使用HMGB2中和抗体可以逆转HMGB2对血管新生的负性作用，为临床治疗缺血性疾病提供潜在的治疗靶点。