β_(2)肾上腺素受体在erastin诱导的前列腺细胞铁死亡和自噬中的作用及其机制

Effects and mechanism of β_(2) adrenergic receptor in ferroptosis and autophagy induced by erastin in prostate cancer

目的探讨β2肾上腺素受体(ADRB2)在铁死亡激活剂erastin(Era)诱导的前列腺癌细胞铁死亡、自噬中的作用及可能的分子机制。方法取慢病毒或对照感染的PC-3细胞,设置sh-NC组(正常培养)、sh-NC+Era组(10μmol/L Era处理24 h)、sh-ADRB2组(正常培养)与sh-ADRB2+Era组(10μmol/L Era处理24 h)。采用CCK-8法检测铁死亡激活剂Era和铁死亡抑制剂ferrostatin-1(Fer-1)处理后的细胞存活率,透射电镜观察细胞形态变化,丙二醛(MDA)检测试剂盒检测MDA含量,铁离子比色法检测铁离子含量。Western blotting检测胱氨酸谷氨酸转运体(XCT)、铁蛋白重链1(FTH1)、谷胱甘肽过氧化物酶(GPX4)、p62、LC3、c-Jun N-末端激酶(JNK)、c-Jun、p-c-Jun蛋白表达水平。注射ADRB2敲低的PC-3稳转株,构建裸鼠成瘤模型并用Era处理,分为sh-NC组、sh-NC+Era组、sh-ADRB2组与sh-ADRB2+Era组,每组4只。隔天记录瘤体体积及最终瘤体重量,并采用免疫组化检测ADRB2、JNK、c-Jun、p-c-Jun的表达情况。结果Era处理后PC-3细胞存活率下降(P<0.01),加用Fer-1处理后PC-3细胞存活率恢复(P<0.01)。透射电镜下可见,Era处理后PC-3细胞发生铁死亡和自噬形态学改变,MDA和铁离子含量增高(P<0.05或P<0.01);敲低ADRB2并用Era处理后PC-3细胞存活率进一步下降(P<0.05),MDA和铁离子含量进一步升高(P<0.01),FTH1、XCT、GPX4和LC3蛋白表达水平降低(P<0.05或P<0.01),p62蛋白和JNK通路相关基因JNK、c-Jun、p-c-Jun蛋白表达水平升高(P<0.01);JNK抑制剂处理后,FTH1、XCT和LC3表达水平升高,p62表达水平降低(P<0.01)。PC-3裸鼠模型中,sh-ADRB2+Era组瘤体体积明显小于sh-NC+Era组和sh-ADRB2组(P<0.05或P<0.01);免疫组化检测结果显示,与sh-NC组比较,sh-ADRB2组ADRB2蛋白表达水平降低(P<0.05),JNK、c-Jun和p-c-Jun蛋白表达水平升高(P<0.01);与sh-NC+Era组比较,sh-ADRB2+Era组ADRB2蛋白表达水平降低,JNK、c-Jun和p-c-Jun蛋白表达水平升高(P<0.05)。结论ADRB2可能通过JNK/c-Jun通路调控前列腺癌细胞中Era诱导的铁死亡和自噬。

Objective To investigate the effects and mechanism ofβ2 adrenergic receptors(ADRB2)in ferroptosis and autophagy induced by erastin(Era)in prostate cancer.Methods PC-3 cells were infected with lentivirus or control and set to sh-NC group(normal culture),sh-NC+Era group(10μmol/L Era treatment for 24 h),sh-ADRB2 group(normal culture),and sh-ADRB2+Era group(10μmol/L Era treatment for 24 h).The viability of the cells treated with Era and ferrostatin-1(Fer-1)was measured by CCK-8 assay.The cell morphology was analyzed by transmission electron microscopy.The malondialdehyde(MDA)content was measured by the Lipid Oxidation Detection Kit and the iron level by Iron Colorimetric Assay.Western blotting was used to detect the expressions of cystine-glutamate exchanger(XCT),ferritin heavy chain 1(FTH1),glutathione peroxidase 4(GPX4),p62,LC3,JNK,c-Jun,and p-c-Jun.PC-3 cells with ADRB2 knockdown were injected into nude mice to construct a xenograft model and then treated with Era.The animals were divided into sh-NC group,sh-NC+Era group,sh-ADRB2 group,and sh-ADRB2+Era group,with 4 mice in each group.The tumor volumes were recorded every other day and the final tumor weight was measured at study termination.The expressions of ADRB2,JNK,c-Jun,and p-c-Jun were detected by immunohistochemistry(IHC).Results The viability of PC-3 cells decreased after Era treatment(P<0.01)and recovered after Fer-1 treatment(P<0.01).Morphological changes of ferroptosis and autophagy were observed in Era-treated cells,and MDA and iron ion contents up-regulated(P<0.05 or P<0.01).Knockdown of ADRB2 and Era treatment further inhibited PC-3 cell viability(P<0.05),and MDA and iron ion contents up-regulated(P<0.01).The expressions of ferroptosis-related proteins FTH1,XCT,GPX4,and LC3 down-regulated(P<0.05 or P<0.05),p62 and JNK pathway�related proteins JNK,c-Jun,and p-c-Jun were up-regulated(P<0.01).After JNK inhibitor treatment,the expressions of FTH1,XCT,and LC3 increased,and p62 decreased(P<0.01).In the PC-3 xenograft model,tumor volume in sh-ADRB2+Era group was significantly smaller than those in sh-NC+Era group and sh-ADBR2 group(P<0.05 or P<0.01).IHC showed that compared with sh�NC group,ADRB2 protein expression level was down-regulated in sh-ADRB2 group(P<0.05),while JNK,c-Jun,and p-c-Jun protein expression levels were elevated(P<0.01).Compared with sh-NC+Era group,the ADRB2 protein expression level in sh-ADRB2+Era group was down-regulated,while JNK,c-Jun,and p-c-Jun protein expression levels were up-regulated(P<0.05).Conclusion ADRB2 regulated ferroptosis and autophagy induced by Era via JNK/c-Jun pathway in prostate cancer.