Jin Yong Chun, Lee Young Soo, Kim Young Min, Seo Han Geuk, Lee Jae Heun, Kim Hye Jung, Yun-Choi Hye Sook, Chang Ki Churl
Department of Pharmacology, Institute of Health Sciences, School of Medicine Gyeongsang National University, Jinju 660-751, Korea.
J Pharmacol Exp Ther. 2009 Aug;330(2):440-8. doi: 10.1124/jpet.108.150342. Epub 2009 May 20.
We examined our hypothesis that (S)-1-(alpha-naphthylmethyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (CKD712) inhibits apoptosis in myocardial ischemia and reperfusion (I/R) injury in vivo via activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway and by reducing inflammation during I/R. To do this, we induced a 30-min period of ischemia by occlusion of the left anterior descending coronary artery of the rat followed by a 2-h (for phosphorylation of Akt), 6-h (for biochemical analysis), or 24-h (for functional analysis) period of reperfusion to determine the effect of CKD712 treatment. Pretreatment with CKD712 significantly improved myocardial function as evidenced by an increase in the +/-dP/dt and a decrease in the infarct size, which were antagonized by a PI3K inhibitor, wortmannin (WT). Interestingly, CKD712 increased the phosphorylation of Akt and cAMP-response element-binding protein and increased the expression of the Bcl-2 gene, but it reduced the expression of the Bax gene. CKD712 decreased not only the expression but also the activity of the caspase-3 protein in the myocardium after reperfusion. Thus, all of the antiapoptotic effects of CKD712 were significantly inhibited by WT. Furthermore, the antiapoptotic effects of CKD712 and its inhibition by WT in myocardium after reperfusion were confirmed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining. Finally, CKD712 was found to reduce the serum levels of the high-mobility group box 1 protein, tumor necrosis factor-alpha, and the cardiac troponin I protein in addition to tissue levels of malondialdehyde and myeloperoxidase activity in I/R hearts. Taken together, both the activation of PI3K/Akt and its anti-inflammatory action prevent apoptosis in myocardial I/R injury by CKD712.
（S）-1-（α-萘甲基）-6,7-二羟基-1,2,3,4-四氢异喹啉（CKD712）在体内通过激活磷脂酰肌醇3-激酶（PI3K）/Akt信号通路以及减轻心肌缺血再灌注（I/R）损伤期间的炎症反应来抑制细胞凋亡。为此，我们通过结扎大鼠左前降支冠状动脉诱导30分钟的缺血，随后分别进行2小时（用于检测Akt磷酸化）、6小时（用于生化分析）或24小时（用于功能分析）的再灌注，以确定CKD712治疗的效果。CKD712预处理显著改善了心肌功能，表现为±dP/dt增加和梗死面积减小，而PI3K抑制剂渥曼青霉素（WT）可拮抗这些作用。有趣的是，CKD712增加了Akt和环磷酸腺苷反应元件结合蛋白的磷酸化，并增加了Bcl-2基因的表达，但降低了Bax基因的表达。CKD712不仅降低了再灌注后心肌中半胱天冬酶-3蛋白的表达，还降低了其活性。因此，WT可显著抑制CKD712的所有抗凋亡作用。此外，末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记染色证实了CKD712在再灌注后心肌中的抗凋亡作用及其被WT抑制的情况。最后，发现CKD712除了降低I/R心脏中丙二醛的组织水平和髓过氧化物酶活性外，还降低了血清中高迁移率族蛋白B1、肿瘤坏死因子-α和心肌肌钙蛋白I的水平。综上所述，PI3K/Akt的激活及其抗炎作用可防止CKD712诱导的心肌I/R损伤中的细胞凋亡。
