CD20^+细胞的含量和HMGB1与心肌缺血的相关性

Correlation between Proportion of CD20^+ Cells or HMGB1 and Myocardial Ischemia

目的探讨脾脏组织CD20^+细胞的含量和心肌高迁移率族蛋白B1(high mobility group protein B1,HMGB1)与小鼠心肌缺血的相关性。方法 50只成年雄性C57BL/6小鼠,随机分为正常组(NC组)、正常+抗HMGB1抗体组(NC+抗HMGB1抗体组)、心肌缺血组(MI组)、心肌缺血+IgG抗体组(MI+IgG抗体组)、心肌缺血+抗HMGB1抗体组(MI+抗HMGB1抗体组),每组各10只。采用腹腔注射高剂量异丙肾上腺素(isoproterenol,ISO)法,建立小鼠急性心肌缺血模型。于第7天腹腔注射ISO 12h后,分别予以IgG抗体、抗HMGB1抗体腹腔注射。心脏超声检测小鼠心功能;苏木精-伊红染色、天狼星红染色观察心肌组织病理学变化;免疫组化测定心肌HMGB1表达;原位末端标记法检测心肌细胞凋亡指数;流式细胞术检测各组小鼠脾脏组织中CD20^+细胞含量。结果与NC组相比,MI组心肌组织明显损伤、纤维化加重,凋亡指数升高,射血分数和左室短轴缩短率降低,脾脏组织中CD20^+细胞含量升高(均P<0.05);与MI组相比,MI+IgG抗体组心肌组织损伤减轻不明显、纤维化无减少,凋亡指数、射血分数和左室短轴缩短率、脾脏组织中CD20^+细胞含量等均无明显变化(均P>0.05);与MI组相比,MI+抗HMGB1抗体组心肌组织损伤减轻、纤维化减少,射血分数和左室短轴缩短率升高,凋亡指数、脾脏组织中CD20^+细胞含量均降低(均P<0.05)。结论 CD20^+细胞含量的变化在心肌缺血的发展中起着重要作用,抗HMGB1抗体对心肌缺血具有保护作用,其保护机制可能与抗HMGB1抗体抑制了CD20^+细胞活化,减轻心肌缺血过程中的免疫反应有关。

Objective To investigate the correlation between the proportion of CD20+cells or high mobility group protein B1(HMGB1)and myocardial ischemia in mice.Methods Fifty adult male C57BL/6 mice were randomly divided into normal group(group NC),anti-HMGB1 antibody group(group anti-HMGB1 antibody),myocardial ischemia group(group MI),myocardial ischemia with IgG antibody group(group MI+IgG),myocardial ischemia with anti-HMGB1 antibody group(group MI+anti-HMGB1 antibody)with ten mice in each group.The model of acute myocardial ischemia was established by intraperitoneal injection of high-dose isoproterenol(ISO).Twelve hours after intraperitoneal injection of ISO on the 7th day,IgG and anti-HMGB1 antibodies were injected intraperitoneally.The hematoxylin-eosin staining and Sirius red staining were used to observe the pathological changes of myocardial tissue.The expression of HMGB1 was detected by immunohistochemistry.The cardiomyocyte apoptic index was detected by TUNEL assay and the proportion of CD20+cells in the spleen of each group by flow cytometry.Results The myocardial tissues experienced obvious injuries,the fibrosis,the apoptosis index and the proportion of CD20+cells were significantly increased,and the ejection fraction and left ventricular fractional shortening were markedly decreased in the MI group as compared with the NC group(all P<0.05).These indices in MI+IgG antibody group were not significantly different from MI group(all P>0.05).However,the MI+anti-HMGB1 antibody group had less myocardial injuries,less fibrosis,higher ejection fraction,left ventricular fractional shortening and lower apoptosis index,and lower CD20+cells proportion in spleen than MI group did(all P<0.05).Conclusion Changes in the proportion of CD20+cells play an important role in the process of myocardial ischemia.The anti-HMGB1 antibody has a protective effect on myocardial ischemia,which involves the inhibition of the activation of CD20+cells and of immune response during myocardial ischemia.