CX40和miR-155在冠状动脉粥样硬化性心脏病猝死者心肌中的表达及其法医学意义

Expression and significance of CX40 and miR-155 in the patients of sudden coronary death

目的鉴定在冠状动脉粥样硬化性心脏病猝死者心肌中心肌连接蛋白(connexin,CX)40、免疫及炎症相关的小分子RNA(micro155)的表达及探讨其法医病理学意义。方法在2014-2015年间法医尸体解剖工作中选出22例符合冠心病猝死的心脏标本(标本严格按照冠状动脉粥样硬化性心脏病的标准进行筛选)作为试验组,再选取10例非冠心病猝死者作为对照组;对筛选出两组中所有的蜡块进行连续切片,HE染色;利用免疫组织化学染色来检测CX40在心肌中的表达;蜡块心肌组织中提取micr RNA,利用RT-PCR法检测每组中mi R-155的表达情况;数据统计学处理采用SPSS18.0统计软件分析,P<0.05为差异有统计学意义。结果 HE染色观察分析:试验组切片镜下可见心肌纤维多处断裂,细胞间质充血水肿,且伴有脂肪变性和脂质沉积;有纤维斑块形成,内部有无定型的坏死崩解物质,镜下观察呈现针形空隙,底部和边缘有肉芽组织和纤维组织,并有泡沫细胞聚集和淋巴细胞浸润;对照组心肌细胞形态正常,各动脉管腔无狭窄;CX40免疫组织化学染色结果:非冠心病猝死组显示磷酸化心肌连接蛋白40大量分布于心肌闰盘处,排列整齐并有一定的规律性;冠心病猝死组显示心肌连接蛋白40在心肌梗死部位数量减少甚至完全消失,排列散乱,分布不均匀;RT-PCR结果表明mi R-155在冠心病猝死者中的表达显著上调,且在试验组和对照组中差异有统计学意义(P<0.01)。结论在冠心病猝死患者的心肌中CX40含量减少,mi R-155显著表达,为冠心病猝死法医学鉴定提供了理论依据。

Objective To identify the expression of CX40 and miR-155 in myocardium in patients with sudden coronary death （SCD） and To explore its meaning of forensic pathology. Methods 22 cases autopsy case specimens that were diagnosed Sud- den Coronary Death as experimental group, and 10 cases autopsy case specimens that were diagnosed non-Sudden Coronary Death as control group; Cut all the wax stones into slices and then haematoxylin-eosin staining; Immunohistoehemical technique were used to detect the expression of CX40; Use the Paraffin embedding tissue mirnas rapid extraction kit to extract miRNA- 155; The expression of miRNA-155 extracted from blocks in every group was investigated by RT-PCR; Using SPSS 18.0 statistical software analysis data statistics processing, P〈0.05 showed statistically significant. Results In the experimental group： the pathologic changes of myocardi- al tissue included edema and congestion in mesenchyma, and inflammatory cells infiltration, and large area of myocardial fibers broke; Fiber plaque formation and foam cell formation and aggregation in plaque; There are areas of necrosis and collapse internal; And at the bottom of the edge with granulation tissue and fibrous tissue; Normal myocardial cells in the control group,there are no nar- row in the arterial lumen; Immunohistochemieal technique： in the control group： the expression of connexin 40 was mainly observed in intercalated disc at the end of myocardium, with less expression on cell surfaeeand in cytoplasm; In the experimental group： the number of connexin 40 reduced or even completely disappeared in the part of myocardial infarction; CX40 unevenly distributed; The expression of miRNA-155 in the sudden coronary death group was higher compared to normal myocardial group （P〈0.01）. Conclu- sion The abnormal expression of CX40 and miR-155 in the sudden coronary death group provided a theoretical basis for forensic identification in the sudden death of coronary heart disease （CHD）.