脑钠肽在心脏性猝死与非心脏性猝死心肌组织中的表达

Expression of Brain Natriuretic Peptide in Myocardial Tissue of Sudden Cardiac Death and Non-sudden Cardiac Death

目的研究法医鉴定案例心肌组织中脑钠肽(brain natriuretic peptide,BNP)的表达规律,探讨BNP在心脏性猝死法医学鉴定中的应用价值。方法收集中国医科大学法医鉴定中心2008年12月至2014年5月受理的解剖案例资料96例,其中心脏性猝死组62例,非心脏性猝死组34例。分别提取左、右心室壁心肌组织,应用HE染色、免疫组织化学染色、Western印迹法、实时荧光定量逆转录聚合酶链反应(quantitative real-time reverse transcription-polymerase chain reaction,RT-q PCR)等技术检测心肌组织BNP蛋白和BNP m RNA的表达。结果免疫组织化学染色结果显示,心脏性猝死组BNP在心肌组织中呈弥漫阳性表达,非心脏性猝死组BNP染色呈点片状或弥漫阳性表达,但程度较浅。Western印迹法结果显示,心脏性猝死组左心室壁心肌组织中BNP蛋白表达较高。RT-q PCR结果显示,心室壁BNP m RNA与心脏质量、双肺质量、心包液氨基末端脑钠肽前体浓度具有正相关性。心脏性猝死组左心室壁BNP m RNA相对表达量较非心脏性猝死组高(P<0.05)。结论心肌组织BNP蛋白、BNP m RNA的表达与死因有关,结合病理学改变,对法医病理学鉴定案例中心脏性猝死的诊断及死亡机制的分析具有一定的实际意义。

Objective To study the expression pattern of brain natriuretic peptide（BNP） in myocardial tissue from forensic routine cases and to explore its application value in the forensic determination of sudden cardiac death（SCD）. Methods The data of 96 autopsy cases accepted by the center of Medicolegal Investigation of China Medical University between December 2008 to May 2014 were collected.There were 62 cases in SCD group cardiac and 34 cases in non-SCD group. The myocardial tissues were taken from left and right ventricular wall, respectively. The expressions of BNP protein and BNP m RNA in myocardial tissue were detected by HE staining, immunohistochemical staining, Western blotting and quantitative real-time reverse transcription-polymerase chain reaction（RT-q PCR）, etc. Results The immunohistochemical staining of myocardial tissue showed diffusely positive staining in SCD group,and patchily or diffusely positive staining in non-SCD group with lighter degree. The result of Western blotting showed that the expression of BNP protein elevated in left ventricular wall of SCD group. The result of RT-q PCR showed a positive correlation between the BNP m RNA expressions in bilateral ventricular walls and the heart weight, bilateral lung weight, and N-terminal prohormone of brain natriuretic peptide（NT-pro BNP） concentration. There were large differences between the BNP m RNA concentrations in SCD group and non-SCD group, and the former was statistically higher（P〈0.05）. Conclusion The expressions of BNP protein and BNP m RNA in myocardial tissue are related to the causes of death. Combined with pathological changes, the expressions of BNP protein and BNP m RNA in myocardial tissue have certainly practical significance for the determination of SCD and the analysis of the death mechanism in the cases related to forensic pathology.