ELA/APJ通過上調(diào)miR-133a抑制心肌細(xì)胞在缺血缺氧條件下凋亡的機(jī)制研究

陳旭翔　侯婧瑛　龍會(huì)寶　吳浩　伍權(quán)華　楊歡　符佳穎　王彤

[摘要] 目的 觀察血管緊張素受體AT1相關(guān)的受體蛋白（APJ）的內(nèi)源性配體ELABELA（ELA）對(duì)心肌細(xì)胞在缺血缺氧條件下凋亡的影響，并探討miR-133a在其中的調(diào)控機(jī)制。 方法 將體外培養(yǎng)的心肌細(xì)胞分為Control組、ELA治療組、ELA+siAPJ組、ELA+siAPJ NC組、ELA+miR-133a inhibitor組、ELA+ miR-133a inhibitor NC組，在缺血缺氧條件（無血清，1%體積分?jǐn)?shù)O2）下培養(yǎng)24 h。免疫熒光鑒定心肌細(xì)胞標(biāo)志物心肌α肌動(dòng)蛋白（α-SA）和心肌肌鈣蛋白T（cTnT）表達(dá)情況。流式細(xì)胞儀檢測(cè)各組細(xì)胞凋亡情況。Western blot、qRT-PCR檢測(cè)各組細(xì)胞APJ、miR-133a的表達(dá)情況。 結(jié)果 ①與Control組比較，ELA治療組細(xì)胞早期凋亡率與晚期凋亡率顯著減少（P < 0.01）;②與對(duì)應(yīng)的NC組細(xì)胞比較，ELA+siAPJ組、ELA+miR-133a inhibitor組細(xì)胞早期凋亡率與晚期凋亡率明顯增加（P < 0.01）;③與Control組比較，ELA治療組細(xì)胞APJ的蛋白與mRNA表達(dá)量、miR-133a的mRNA表達(dá)量均明顯升高（P < 0.01）;④采用siRNAs阻斷APJ的表達(dá)后，與ELA+siAPJ NC組比較，ELA+siAPJ組細(xì)胞APJ的蛋白與mRNA表達(dá)量、miR-133a的mRNA表達(dá)量均顯著減少（P < 0.01）。采用siRNAs阻斷miR-133a的表達(dá)后，ELA+miR-133a inhibitor組細(xì)胞APJ的蛋白與mRNA表達(dá)量與ELA+miR-133a inhibitor NC組比較，差異無統(tǒng)計(jì)學(xué)意義（P > 0.05），miR-133a的mRNA表達(dá)量顯著減少（P < 0.01）。 結(jié)論 ELA能夠抑制心肌細(xì)胞在缺血缺氧環(huán)境下的凋亡，此效應(yīng)可能與其激活A(yù)PJ之后上調(diào)miR-133a有關(guān)。

[關(guān)鍵詞] ELABELA;血管緊張素受體AT1相關(guān)的受體蛋白;缺血缺氧;心肌細(xì)胞;細(xì)胞凋亡

[中圖分類號(hào)] R331.31 ? ? ? ? ?[文獻(xiàn)標(biāo)識(shí)碼] A ? ? ? ? ?[文章編號(hào)] 1673-7210（2019）05（c）-0012-06

[Abstract] Objective To investigate the effect of ELABELA （ELA）， which is a ligand of angiotensin receptor AT1 associated endogenous protein （APJ）， on cardiomyocytes apoptosis under ischemia-hypoxia condition and to explore the regulatory mechanism of miR-133a. Methods The cardiomyocytes were cultured for 24 h under ischemia-hypoxia conditions （without serum， 1% O2） and divided into control group， ELA treatment group， ELA+siAPJ group， ELA+siAPJ NC group， ELA+miR-133a inhibitor group and ELA+miR-133a inhibitor NC group. The expression of myocardial α-actin （α-SA） and cardiac troponin T （cTnT） were observed by immunofluorescence. Flow cytometry was used to detect apoptosis. Western blot and qRT-PCR were used to detect the expression of APJ and miR-133a. Results ①Compared with the control group， the rate of early and late apoptosis in ELA treatment group was significantly decreased （P < 0.01）; ②compared with corresponding NC group， the early and late apoptosis rate of ELA+siAPJ group and ELA+miR-133a inhibitor group were significantly increased （P < 0.01）; ③the expression of APJ and miR-133a in ELA treatment group was significantly higher than that in control group after 24 h culture （P < 0.01）; ④after blocking the expression of APJ and miR-133a by siRNA， compared with that in the corresponding NC group， the protein and mRNA expression level of APJ and mRNA expression level of miR-133a were significantly decreased in ELA+siAPJ group （P < 0.01）. The protein and mRNA expression level of APJ did not change significantly in ELA+miR-133a inhibitor group （P > 0.05）， but the mRNA expression level of miR-133a was significantly decreased （P < 0.01）. Conclusion ELA could inhibit the apoptosis of cardiomyocytes in ischemic and hypoxic environment. This effect might be related to up-regulation of miR-133a after activation of APJ.