急性冠脉综合征病程中MDSCs的动员及作用研究

Mobilization and pathological effect of MDSCs in acute coronary syndrome

目的:研究急性冠脉综合征(ACS)时体内髓系抑制细胞(MDSCs)CD11b+Gr-1+的动态变化过程以及MDSCs参与ACS过程的可能机制。方法:55例患者根据临床症状及冠脉造影情况分为ACS组(n=42)和对照组(n=13),流式细胞术分析外周血中MDSCs比例(MDSCs%)。24只BLAB/C小白鼠随机分为普通饮食组(n=12)和高脂饮食组(n=12),分别喂养8周,流式细胞术分析外周血中MDSCs%,全自动生化分析仪测定血清中总胆固醇、低密度脂蛋白水平,HE染色及免疫荧光分析动脉斑块的性质、特点。30只雄性BLAB/C小白鼠随机分为对照组(n=10)和急性心肌梗死(AMI)模型组(n=20),流式细胞术分析骨髓、脾脏、外周血中MDSCs%;分离培养小鼠骨髓单个核细胞,以粒细胞-巨噬细胞集落刺激因子(GM-CSF)诱导分化48 h,加入100 mg.L-1氧化修饰低密度脂蛋白(ox-LDL)孵育48 h,以油红O染色鉴定泡沫细胞。结果:与对照组相比ACS患者外周血中MDSCs%显著升高(P<0.001),ACS患者经冠脉介入治疗(PCI)后外周血中MDSCs%进行性降低;经高脂饮食喂养8周后小鼠外周血中MDSCs%显著升高(P<0.001),且以CD11b+Ly6G+粒系亚型为主,CD11b+Ly6C+单核系亚型可吞噬脂质形成单核样泡沫细胞参与不稳定斑块的形成;小鼠AMI超急性期至急性期MDSCs在体内呈现动态动员变化,与肌钙蛋白呈现较好相关性(P<0.001)。结论:CD11b+Ly6C+MDSCs可逐步分化成为泡沫样细胞,参与动脉不稳定斑块的进展,形成ACS的积累阶段;CD11b+Ly6G+MDSCs可分化为中性粒样细胞,参与形成ACS的急性病程进展;MDSCs持续参与ACS的发病过程,MDSCs%测定可为AMI发生发展的诊断提供参考。

Objective： To study the dynamic process of CD11 b ＋ Gr-1 ＋ myeloid derived suppressor cells （MDSCs） in ACS and analyze the possible mechanisms of MDSCs involved in ACS. Methods： 55 patients were divided into ACS（n =42） and control group （n = 13 ） according to clinical symptoms and coronary angiography; 24 BLAB/C mice randomly divided into normal diet group（ n = 12） and high fat diet group（ n = 12） for 8 weeks; 30 male BLAB/C mice were randomly divided into control group （n = 10 ） and acute myocardial infarction（AMI） group（ n = 20 ）; percentage of MDSCs （MDSCs%） in bone marrow, spleen, peripheral blood were analyzed by flow cytometry; automatic biochemical analyzer were used to detect TC, LDL levels in serum; HE staining and immunofluorescence were used to identify the nature of arterial plaque and characteristics; MDSCs were cultured and GM-CSF were added to induce the differentiation of the cells for 48 hours followed by adding oxidized low density lipoprotein（ ox-LDL 100 mg＇L-1） for another 48 hours and foam cell were stained by oil red O. Results： Compared with the control group MDSCs in ACS patients was significantly higher（ P 〈 0. 001 ） and MDSCs% in peripheral blood decreased greatly after PCI; 8 weeks of high-fat diet feeding significantly elevated CDllb ＋ Ly6G~ MDSCs% in peripheral blood （P 〈 0. 001 ） , CDllb~ Ly6C＋ MDSCs phagocytized lipids and developed into monocyte-like foam cells involved in the formation of unstable plaques; mobilization of MDSC% in AMI mice showed dynamic changes from hyperacute to acute phase as well as good correlation with troponin I （ P 〈 0. 001 ）. Conclusion： CDllb Ly6C ＋ MDSCs can gradually differentiate into foam-like cells involved in the progress of arterial instability plaque at the accumulating phase of ACS; CDllb＋ Ly6G＋ MDSCs can differentiate into neutrophil-like cells involved in the progression of acute phase of ACS; MDSCs are involved in all pathogenesis process of ACS and can provide a reference for the diagnosis of AMI.