PCSK9 inhibition protects against myocardial ischemia-reperfusion injury via suppressing autophagy
PCSK9 inhibition protects against myocardial ischemia-reperfusion injury via suppressing autophagy
复制标题
DOI：
10.1016/j.mvr.2022.104371
复制
发表时间：
2022-04-22
影响因子：
3.1
通讯作者：
Li, Wei
中科院分区：
文献类型：
--
作者：
Huang, Guangwei;Lu, Xiyang;Li, Wei
目的：自噬在心肌缺血再灌注（I/R）损伤中起重要作用。然而，关于其保护和有害作用仍有相当大的争论。本研究旨在探讨前蛋白转化酶枯草杆菌蛋白酶9（PCSK 9）及其抑制剂在心肌缺血再灌注损伤自噬（MRI）中的作用。冠状动脉阻断30分钟产生心肌IR，再灌注所需时间随时间梯度线性增加，从2小时到2天。在确定最佳再灌注期后，形成三个组：假手术组、I/R组和I/R + P组（在手术前1周半小时皮下施用稀释于2 ml无菌注射水中的PCSK 9抑制剂（依洛莫司汀）10 mg/kg。采用心电图、心功能、氯化三苯基四氮唑（TTC）/伊文思蓝（EB）染色法测定各组大鼠心肌梗死面积。HE染色观察各组心肌细胞形态学改变。同时采用免疫印迹、免疫组化和Masson三色染色法检测心肌纤维化、PCSK 9和自噬蛋白的表达。结果表明，PCSK 9表达水平在MRI中显著增加，如自噬调节蛋白轻链3（LC 3）和Beclin-1水平增加所示，其激活心肌细胞中的自噬，加重心肌损伤，并增加了心肌梗塞的面积。同时，PCSK 9通过Bcl-2/腺病毒E1 B 19-kDa相互作用蛋白（BNIP 3）途径调节线粒体自噬，该途径控制心肌梗死MRI。结论：PCSK 9在心肌缺血再灌注损伤心脏中表达上调，并通过BNIP 3途径调节线粒体自噬，进而参与心肌梗死后再灌注损伤。PCSK 9抑制通过抑制自噬来保护心肌缺血-再灌注损伤。
Objectives: Autophagy is critical for myocardial ischemia-reperfusion (I/R) injury. However, there is still considerable debate over its protective and deleterious effects. The purpose of this study was to determine the involvement of the proprotein convertase subtilisin/Kexin type 9 (PCSK9) and its inhibitor in myocardial ischemia-reperfusion injury autophagy (MRI).Methods: Nine groups of eighty rats were used: sham, I/R2 h, I/R4 h, I/R6 h, I/R8 h, I/R1 d, and I/R2 d. A 30-min coronary artery blockage was used to produce myocardial IR. The time required for reperfusion rose linearly with the time gradient, from 2 h to 2 days. Following the determination of the best reperfusion period, three groups were formed: sham, I/R, and I/R + P (PCSK9 inhibitor (evolocumab) 10 mg/kg diluted in 2 ml sterile injection water was administered subcutaneously 1 week and half an hour before to surgery. Each group's infarction area was determined by electrocardiography (ECG), cardiac function, and 2,3,5-triphenyltetrazolium chloride (TTC) /Evan Blue (EB) staining. To detect morphological alterations in myocardial cells in each group, hematoxylin and eosin (HE) staining was used. Meanwhile, western blotting, immunohistochemistry, and Masson trichrome staining were utilized to quantify myocardial fibrosis and PCSK9 and autophagy protein expression.Results: The results indicated that PCSK9 expression levels increased significantly in MRI, as indicated by increased levels of the autophagy regulatory protein light chain 3 (LC3) and Beclin-1, which activated autophagy in cardiomyocytes, exacerbated myocardial injury, and increased the size of myocardial infarcts. Meanwhile, PCSK9 regulates mitophagy via the Bcl-2/adenovirus E1B 19-kDa interacting protein (BNIP3) pathway, which controls myocardial infarction MRI throughout. Additionally, the PCSK9 inhibitor significantly decreased autophagy, enhanced cardiac function, and reduced the extent of reperfusion injury, consequently reducing myocardial infarct size expansion.Conclusion: PCSK9 is upregulated in the myocardial ischemia-reperfusion injury hearts and regulates mitophagy via the BNIP3 pathway, which in turn contributes to reperfusion injury after myocardial infarction. PCSK9 inhibition protects against myocardial ischemia-reperfusion injury via suppressing autophagy.