JMJD3对STAT3的调控在阿霉素心肌病中的作用研究

Effects of JMJD3 on DOX-induced cardiotoxicity through regulating STAT3

目的探究组蛋白去甲基化酶(histone demethylase Jumonji D3,JMJD3)与信号转导与转录激活因子3(signal transducer and activator of transcription 3,STAT3)在阿霉素(doxorubicin,DOX)诱导的心肌病中的作用及机制。方法DOX刺激H9C2心肌细胞12 h,在细胞水平建立DOX心肌病模型;SD大鼠腹腔注射DOX,在动物水平建立DOX心肌病模型;左心室壁多点注射腺病毒法在整体动物水平过表达JMJD3;腺病毒感染法在细胞水平过表达JMJD3和STAT3;干扰序列转染法敲低JMJD3;TMRE染色检测线粒体膜电位变化。结果在细胞和整体动物水平建立DOX心肌病模型;在细胞及动物水平均观察到DOX引起JMJD3的表达水平上调;在细胞水平单独过表达JMJD3导致心肌细胞凋亡;过表达JMJD3加剧DOX引起的心肌细胞凋亡;敲低JMJD3缓解DOX引起的细胞损伤;过表达STAT3缓解DOX以及JMJD3引起的细胞凋亡;单独过表达JMJD3或DOX处理均可以降低STAT3的总蛋白及其磷酸化水平。结论DOX可能通过诱导JMJD3表达上调,进而抑制STAT3的表达,从而引起心肌细胞凋亡。

Aim To investigate the regulatory relationship and mechanism of JMJD3 and STAT3 in DOX-induced cardiotoxicity.Methods To establish the model of cardiotoxicity in vitro and in vivo,H9C2 cells weretreated with DOX(1μmol·L^-1)for 12 hours;Sprague-Dawley rats were subcutaneously injected with a cumulative dose of 15 mg·kg^-1 DOX.The adenovirus encoding JMJD3(Ad-JMJD3)was transduced into the rat left ventricle via intramyocardial injection.The recombinant adenovirus(Ad-JMJD3 or Ad-STAT3)infection were used to overexpress JMJD3 or STAT3 in cardiomyocytes.Knockdown JMJD3 was achieved by transfecting with siRNA of JMJD3 in H9C2 cells.The method of TMRE was used to detect the mitochondrial membrane depolarization.Results The model of cardiotoxicity was successfully built both in vivo and in vitro by DOX.The mRNA and protein level of JMJD3 in DOX-induced cardiotoxicity both in vivo and in vitro were significantly raised compared with those of control or NC group.Ad-JMJD3 significantly aggravated the damage effect of H9C2 cells induced by DOX.JMJD3 knockdown could significantly relieve DOX-induced apoptosis.Ad-STAT3 could obviously attenuate DOX-or Ad-JMJD3-induced apoptosis-related protein expression.Both DOX and Ad-JMJD3 could inhibit the protein expression and phosphorylation level of STAT3.Conclusions DOX caused the up-regulation of protein expression of JMJD3,inhibited STAT3 and p-STAT3 protein expression,thus,aggravating cardiotoxicity.