摘要 目的 观察微小RNA-21(miR-21)与伴有Kazal基序富含半胱氨酸的逆转诱导蛋白(RECK)、Smad7在心脏性猝死（SCD）心肌组织中的表达水平，并探讨其意义。方法 选择因SCD的20例心脏标本作为SCD组；选取20例死因为非心脏疾患的心脏标本作为对照组。应用免疫组织化学染色方法分别检测两组心肌组织中RECK和Smad7表达，采用荧光定量PCR方法检测两组心肌组织中miR-21、RECK和Smad7的表达。 结果 免疫组化染色结果显示，两组心肌组织中RECK、Smad7的表达比较，差异均有统计学意义（Z=－4.008、－2.939，P＜0.05）；两组心肌组织中RECK与Smad7的表达水平呈正相关（r=0.706，P＜0.05）。荧光定量PCR方法检测结果显示，SCD组心肌组织中miR-21与RECK、Smad7相对表达量均呈负相关（r=－0.608、－0.681,P＜0.05)。 结论 SCD心肌组织中miR-21高表达，RECK、Smad7低表达， miR-21与RECK、Smad7联合应用有望作为诊断SCD较为客观的指标。 Abstract：Objective To investigate the expression and significance of microRNA-21 (miR-21), RECK, and Smad7 in myocardial tissue in sudden cardiac death (SCD). Methods A total of 20 heart specimens from patients with SCD as SCD group, and 20 cardiac specimens from patients without heart disease were selected as control group. Immunohistochemical staining was used to measure the protein expression of RECK and Smad7 in myocardial tissue, and quantitative real-time PCR was used to measure the mRNA expression of miR-21, RECK, and Smad7 in myocardial tissue. Results Immunohistochemical staining showed that there was a significant difference in the expression of RECK and Smad7 in myocardial tissue between the two groups (Z=-4.008,-2.939,P<0.05), and there was a positive correlation between RECK and Smad7 in myocardial tissue (r=0.706,P<0.05). Quantitative real-time PCR showed that in the SCD group, the relative expression of miR-21 was negatively correlated with that of RECK and Smad7 (r=-0.608,-0.681,P<0.05). Conclusion There is high expression of miR-21 and low expression of RECK and Smad7 in myocardial tissue in SCD, and combined measurement of miR-21, RECK, and Smad7 can be used as an objective indicator for the diagnosis of SCD
