糖化载脂蛋白A-I调控巨噬细胞极化抑制侧枝循环建立的效应和机制研究

Collaterals dysfunction occurs in diabetic patients with chronic total occlusion of coronary arteries, and the mechanisms behind remain not fully clarified. We ultracentrifuged HDL from the diabetic CTO patients with good or poor collateralization, followed by LC-MS/MS analysis. The results showed that glycation level of apolipoprotein A-I (apoA-I) was significantly increased in HDL from diabetic patients with poor collateralization than that from good collateralization. Injection of glycated apoA-I (g-apoA-I) protein impaired arteriogenesis and muscle regeneration, increased necrosis and fibrosis in ischemic adductor and calf of C57BL mice after femoral arterial ligation. Consistently, the more abundant Ly-6Chi monocytes also found accumulated in ischemic tissue of mice injected with g-apoA-I than those injected with apoA-I or saline, but the M2 macrophages was decreased in g-apoA-I injected mice. The mRNA array of g-apoA-I-treated primary monocyte/macrophage suggested that g-apoA-I aggravated inflammatory, up-regulated the tyrosine protein phosphatase (SHP2) expression, and activated Notch pathway. Such impact might cause arteriogenesis dysfunction in diabetic ischemic tissue, with conversion of macrophage to pro-inflammatory M1, but not anti-inflammatory M2. Combining with data of previous studies and our findings, we speculate that Glycated apoA-I inhibited arteriogenesis through SHP2 dependent pro-inflammatory macrophage polarization is a novel mechanism regarding poor collaterals remodeling in diabetes. In our future study, we will test this hypothesis by establishing femoral arterial ischemia models in mice of RAGE-/- and SHP2ΔM and culturing primary monocyte from those genetic engineering mice, with using inhibitor of Notch or monocyte replenishment experiments.

糖尿病时冠脉慢性闭塞（CTO）后侧支形成障碍，是其预后不良的重要原因。通过对糖尿病CTO侧枝形成良好和不良患者HDL行质谱分析, 发现侧支不良患者其载脂蛋白A1的糖化显著高于侧支良好病人。外源性给予糖化apoA-I能明显抑制下肢缺血小鼠血供恢复，抑制骨骼肌细胞新生，促进坏死和纤维化，诱导炎症细胞浸润，减少M2型巨噬细胞生成。mRNA芯片分析显示酪氨酸蛋白酶SHP2可能参与了糖化apoA-I对侧枝形成的抑制效应。后续研究将以构建给予糖化apoA-I刺激的糖基化终末产物受体（RAGE-/-）和单核/巨噬特异性敲除SHP2小鼠（SHP2ΔM）下肢缺血模型，构建糖化apoA-I处理的原代RAGE-/-和SHP2ΔM髓系单核/巨噬细胞，利用Notch通路抑制剂、单核/巨噬细胞回补实验等方法，阐明糖化apoA-I通过RAGE-SHP2-Notch通路调控巨噬细胞极化，进而抑制缺血后侧枝形成的机制。

糖尿病时冠脉慢性闭塞（CTO）后侧支形成障碍，是其预后不良的重要原因。通过对糖尿病CTO侧枝形成良好和不良患者HDL行质谱分析, 发现侧支不良患者其载脂蛋白A1的糖化显著高于侧支良好病人。外源性给予糖化apoA-I能明显抑制下肢缺血小鼠血供恢复，抑制骨骼肌细胞新生，促进坏死和纤维化，诱导炎症细胞浸润，减少M2型巨噬细胞生成。mRNA芯片分析显示酪氨酸蛋白酶SHP2可能参与了糖化apoA-I对侧枝形成的抑制效应。后续研究将以构建给予糖化apoA-I刺激的糖基化终末产物受体（RAGE-/-）和单核/巨噬特异性敲除SHP2小鼠（SHP2ΔM）下肢缺血模型，构建糖化apoA-I处理的原代RAGE-/-和SHP2ΔM髓系单核/巨噬细胞，利用Notch通路抑制剂、单核/巨噬细胞回补实验等方法，阐明糖化apoA-I通过RAGE-SHP2-Notch通路调控巨噬细胞极化，进而抑制缺血后侧支形成的机制。