Jin Jiaqi, Xu Fan, Zhang Yuxin, Guan Jing, Fu Jihua
Department of Physiology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
Department of Physiology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
Mol Immunol. 2023 Mar;155:27-43. doi: 10.1016/j.molimm.2023.01.004. Epub 2023 Jan 20.
Previously, we revealed a crucial role of 5-HT degradation system (5DS), consisting of 5-HT2A receptor (5-HT2AR), 5-HT synthases and monoamine oxidase A (MAO-A), in ischemia-reperfusion (IR)-caused organ injury. Whereas, platelet activating factor receptor (PAFR) also mediates myocardial ischemia-reperfusion injury (MIRI). Here, we try to clarify the relationship between 5DS and PAFR in mediating MIRI.
H9c2 cell injury and rat MIRI were caused by hypoxia/reoxygenation (H/R) or PAF, and by ligating the left anterior descending coronary artery then untying, respectively. 5-HTR and PAFR antagonists [sarpogrelate hydrochloride (SH) and BN52021], MAO-A, AKT, mTOR and 5-HT synthase inhibitors (clorgyline, perifosine, rapamycin and carbidopa), and gene-silencing PKCε were used in experiments RESULTS: The mitochondrial ROS production, respiratory chain damage, inflammation, apoptosis and myocardial infarction were significantly prevented by BN52021, SH and clorgyline in H/R and PAF-treated cells and in IR myocardium. BN52021 also significantly suppressed the upregulation of PAFR, 5-HTR, 5-HT synthases and MAO-A expression (mRNA and protein), and Gα and PKCε (in plasmalemma) expression induced by H/R, PAF or IR; the effects of SH were similar to that of BN52021 except for no affecting the expression of PAFR and 5-HTR. Gene-silencing PKCε suppressed H/R and PAF-induced upregulation of 5-HT synthases and MAO-A expression in cells; perifosine and rapamycin had not such effects; however, clorgyline suppressed H/R and PAF-induced phosphorylation of AKT and mTOR.
MIRI is probably due to PAFR-mediated 5-HTR activation, which further activates PKCε-mediated 5-HT synthesis and degradation, leading to mitochondrial ROS production.
此前，我们揭示了由5-羟色胺2A受体（5-HT2AR）、5-羟色胺合酶和单胺氧化酶A（MAO-A）组成的5-羟色胺降解系统（5DS）在缺血再灌注（IR）所致器官损伤中起关键作用。然而，血小板活化因子受体（PAFR）也介导心肌缺血再灌注损伤（MIRI）。在此，我们试图阐明5DS与PAFR在介导MIRI中的关系。
H9c2细胞损伤和大鼠MIRI分别通过缺氧/复氧（H/R）或血小板活化因子（PAF）诱导，以及通过结扎左冠状动脉前降支然后松开诱导。实验中使用了5-羟色胺受体（5-HTR）和PAFR拮抗剂[盐酸沙格雷酯（SH）和BN52021]、MAO-A、AKT、mTOR和5-羟色胺合酶抑制剂（氯吉兰、哌立福辛、雷帕霉素和卡比多巴），以及基因沉默的蛋白激酶Cε（PKCε）。
在H/R和PAF处理的细胞以及IR心肌中，BN52021、SH和氯吉兰显著抑制了线粒体活性氧产生、呼吸链损伤、炎症、细胞凋亡和心肌梗死。BN52021还显著抑制了H/R、PAF或IR诱导的PAFR、5-HTR、5-羟色胺合酶和MAO-A表达（mRNA和蛋白）上调，以及Gα和PKCε（在质膜中）表达上调；SH的作用与BN52021相似，但不影响PAFR和5-HTR的表达。基因沉默PKCε抑制了H/R和PAF诱导的细胞中5-羟色胺合酶和MAO-A表达上调；哌立福辛和雷帕霉素没有这种作用；然而，氯吉兰抑制了H/R和PAF诱导的AKT和mTOR磷酸化。
MIRI可能是由于PAFR介导的5-HTR激活，进而激活PKCε介导的5-羟色胺合成与降解，导致线粒体活性氧产生。
