目的 探讨小檗碱对心肌缺血再灌注损伤大鼠线粒体自噬及PTEN诱导激酶1（PTEN induced putative kinase 1，PINK1）/帕金森病蛋白（Parkin）通路的影响。方法 建立心肌缺血再灌注损伤大鼠模型，随机分组为模型组、小檗碱低、高剂量（75、150 mg/kg）组，自噬抑制剂三甲基腺嘌呤（3-MA，100 mmol/L）组、小檗碱+3-MA（150 mg/kg+100 mmol/L）组，每组12只，另取12只正常大鼠设为假手术组。分组处理后，超声检测大鼠左室功能，记录左室收缩末期内径（LVESD）、左室舒张末期内径（LVEDD）、左心射血分数（LVEF）、左室短轴缩短率（FS）；三苯基氯化四氮唑（TTC）染色检测各组大鼠心肌梗死面积，酶联免疫吸附实验（ELISA）检测各组大鼠血清中磷酸肌酸激酶同工酶（CK-MB）、肌钙蛋白I（cTnI）水平；HE染色观察大鼠心肌组织病理变化；透射电镜观察心肌细胞超微结构及线粒体自噬并分析线粒体损伤评分；蛋白免疫印迹法检测各组大鼠心肌组织PINK1、Parkin蛋白及微管轻链蛋白3B（LC3B）、线粒体自噬受体p62（p62）、泛素特异性蛋白酶30（USP30）蛋白表达。结果 与假手术组比较，模型组大鼠心肌组织病理损伤严重，线粒体肿胀及空泡化损伤较多，线粒体损伤评分、心肌梗死面积、LVEDD、LVESD、CK-MB、cTnI水平及PINK1、Parkin、LC3B、p62蛋白表达升高（P<0.05），LVEF及FS、USP30蛋白表达降低（P<0.05）。与模型组比较，3-MA组大鼠心肌组织及线粒体病理损伤加重，LVEF、FS、PINK1、Parkin、LC3B、p62蛋白表达降低（P<0.05），线粒体损伤评分、心肌梗死面积、LVEDD、LVESD、CK-MB、cTnI水平、USP30蛋白表达升高（P<0.05）；小檗碱低、高剂量大鼠心肌组织及线粒体病理损伤减轻，LVEF、FS、PINK1、Parkin、LC3B、p62、USP30蛋白表达升高（P<0.05），线粒体损伤评分、心肌梗死面积、LVEDD、LVESD、CK-MB、cTnI水平降低（P<0.05）。小檗碱+3-MA组大鼠上述各项指标均与小檗碱高剂量组变化趋势相反，且有统计学差异（P<0.05）。结论 小檗碱可能通过激活PINK1/Parkin/P62/LC3B通路促进线粒体自噬，升高USP30表达，减少异常自噬，缓解心肌缺血再灌注损伤。

Objective To investigate the effects of berberine on mitochondrial autophagy and phosphatase and tensin homology deleted on chromosome ten (PTEN)-induced putative kinase 1 (PINK1)/Parkin pathway in rats with myocardial ischemia-reperfusion (MIR). Methods MIR rat model was established and randomly divided into model group, low-dose berberine group (75 mg/kg), high-dose berberine group (150 mg/kg), autophagy inhibitor trimethyladenine (3-MA, 100 mmol/L), berberine + autophagy inhibitor group (150 mg/kg + 100 mmol/L), with 12 rats in each group, and another 12 rats were set as Sham operation group. After grouping and treatment, left ventricular function was detected by echocardiography, left ventricular end systolic diameter (LVESD), left ventricular end diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF) and left ventricular short axis shortening (FS) were recorded. The infarct size was detected by 2,3,5-triphenyltetrazolium chloride (TTC) staining, and the levels of creatine kinase isoenzyme (CK-MB) and troponin I (cTnI) in serum were detected by enzyme-linked immunosorbent assay (ELISA). HE staining was used to observe the pathological changes of myocardium. The ultrastructure and mitochondrial autophagy of cardiomyocytes were observed by transmission electron microscopy (TEM), and mitochondrial damage score was analyzed. The protein expressions of PINK1, Parkin, microtubule associated protein 1 light chain 3B (LC3B), mitochondrial autophagy receptor p62 and ubiquitin specific protease 30 (USP30) were detected by Western blotting. Results Compared with those in the Sham operation group, the pathological damage of myocardial tissue in the model group was serious, and the swelling and vacuolation of mitochondria were more serious, the mitochondrial injury score, myocardial infarction area, LVEDD, LVESD, levels of CK-MB and cTnI, the protein expression levels of PINK1, Parkin, LC3B and p62 were higher (P<0.05), but LVEF, the protein expression levels of FS and USP30 were lower (P<0.05). Compared with those in the model group, the pathological damage of myocardial tissue and mitochondria in 3-MA group was aggravated, LVEF, FS, the protein expression levels of PINK1, Parkin, LC3B and p62 were lower (P<0.05), the mitochondrial injury score, myocardial infarction area, LVEDD, LVESD, levels of CK-MB and cTnI and the protein expression level of USP30 were higher (P<0.05). The pathological damage of myocardial tissue and mitochondria in rats in low and high dose berberine groups was alleviated, LVEF, FS, the protein expression levels of PINK1, Parkin, LC3B, p62 and USP30 were higher (P<0.05), the mitochondrial damage score, myocardial infarction area, LVEDD, LVESD, levels of CK-MB and cTnI were lower (P < 0.05). The changes of the above indexes in berberine + 3-MA group were contrary to those in high-dose berberine group, and the difference was statistically significant (P<0.05). Conclusion Berberine may promote mitochondrial autophagy by activating PINK1/Parkin/p62/LC3B pathway, increase USP30 expression, reduce abnormal autophagy and alleviate MIR injury.

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国家自然科学基金资助项目（81603114）