Li Yun-Peng, Chen Zhen, Cai Yu-Hua
Department of Cardiovasology, Affiliated Dongfeng Hospital, Hubei University of Medicine, Shiyan, Hubei 442008, P.R. China.
Department of Emergency and Evidence-Based Medicine, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China.
Exp Ther Med. 2021 Apr;21(4):374. doi: 10.3892/etm.2021.9805. Epub 2021 Feb 19.
Piperine (PIP) exerts numerous pharmacological effects and its involvement in endoplasmic reticulum (ER) stress (ERS)-led apoptosis has garnered attention. The present study focused on whether PIP played protective effects on hypoxia/reoxygenation (H/R)-induced cardiomyocytes by repressing ERS-led apoptosis. The potential molecular mechanisms in association with the PI3K/AKT signaling pathway were investigated. Primary neonatal rat cardiomyocytes (NRCMs) were isolated and randomized into four groups: Control + vehicle group, control + PIP group, H/R + vehicle group and H/R + PIP group. The H/R injury model was constructed by 4 h of hypoxia induction followed by 6 h of reoxygenation. A total of 10 µM PI3K/AKT inhibitor LY294002 was supplemented to the cells during the experiments. Cell viability and myocardial enzymes were detected to evaluate myocardial damage. A flow cytometry assay was performed to assess apoptotic response. Western blot analysis was performed to detect the expression of related proteins including PI3K, AKT, CHOP, GRP78 and cleaved caspase-12. The results showed that H/R markedly promoted myocardial damage as shown by the increased release of lactate dehydrogenase and creatine kinase levels, but a reduction in cell viability. In addition, ERS-induced apoptosis was markedly promoted by H/R in NRCMs, as shown by the increased apoptotic rates and expression of C/EBP-homologous protein, endoplasmic reticulum chaperone BiP and caspase-12. PIP administration reversed cell injury and ERS-induced apoptosis in H/R. Mechanistic studies concluded that the apoptosis-inhibitory contributions and cardio-favorable effects of PIP were caused partly by the activation of the PI3K/AKT signaling pathway, which was verified by LY294002 administration. To conclude, PIP can reduce ERS-induced apoptosis by activating the PI3K/AKT signaling pathway during the process of H/R injury, which could be a potential therapeutic target for the treatment of myocardial ischemia/reperfusion injury.
胡椒碱（PIP）具有多种药理作用，其在内质网（ER）应激（ERS）诱导的细胞凋亡中的作用已引起关注。本研究聚焦于PIP是否通过抑制ERS诱导的细胞凋亡对缺氧/复氧（H/R）诱导的心肌细胞发挥保护作用。研究了与PI3K/AKT信号通路相关的潜在分子机制。分离原代新生大鼠心肌细胞（NRCMs）并随机分为四组：对照组+溶剂组、对照组+PIP组、H/R+溶剂组和H/R+PIP组。通过4小时缺氧诱导和6小时复氧构建H/R损伤模型。实验期间向细胞中添加10μM的PI3K/AKT抑制剂LY294002。检测细胞活力和心肌酶以评估心肌损伤。进行流式细胞术检测以评估凋亡反应。进行蛋白质印迹分析以检测包括PI3K、AKT、CHOP、GRP78和裂解的caspase-12在内的相关蛋白的表达。结果表明，H/R显著促进心肌损伤，表现为乳酸脱氢酶和肌酸激酶水平释放增加，但细胞活力降低。此外，H/R显著促进NRCMs中ERS诱导的细胞凋亡，表现为凋亡率增加以及C/EBP同源蛋白、内质网伴侣BiP和caspase-12的表达增加。给予PIP可逆转H/R中的细胞损伤和ERS诱导的细胞凋亡。机制研究得出结论，PIP的抗凋亡作用和对心脏的有益作用部分是由PI3K/AKT信号通路的激活引起的，这通过给予LY294002得到验证。总之，PIP可在H/R损伤过程中通过激活PI3K/AKT信号通路减少ERS诱导的细胞凋亡，这可能是治疗心肌缺血/再灌注损伤的潜在治疗靶点。
