吡咯烷二硫代氨基甲酸酯对TGF-β2诱导人晶状体上皮细胞EMT的抑制作用

Inhibition of pyrrolidine dithiocarbamate on transforming growth factor-beta 2 induced epithelial-mesenchymal transition in human lens epithelial cells

目的:探究吡咯脘二硫代氨基甲酸酯(PDTC)对转化生长因子-beta2(TGF-β2)诱导人晶状体上皮细胞(LECs)上皮-间充质转化(EMT)的逆转机制。方法:TGF-β2诱导人晶状体上皮细胞EMT,并给予不同浓度PDTC处理TGF-β2诱导的LECs。CCK-8、划痕试验检测细胞增殖与迁移,Western Blot检测EMT标志物E-cadherin、α-SMA和NF-κB信号传导通路相关蛋白表达,以及凋亡相关蛋白BAX、BCL-2、Caspase-3、细胞周期蛋白D_1的表达。结果:TGF-β2处理组细胞增殖和迁移活力明显高于未添加TGF-β2的实验组;E-cadherin表达下调,α-SMA表达上调。在TGF-β2的作用下NF-κB p65和磷酸化的NF-κB p65表达增加(P<0.05)且在TGF-β210 ng/mL刺激浓度时LECs表现出较强的增殖活力和迁移能力。PDTC逆转EMT和诱导细胞凋亡的机制研究表明,PDTC干预处理后细胞活力和迁移能力都显著降低,PDTC抑制IκB的磷酸化进而抑制NF-κB核移位,NF-κB信号通路中NF-κBp65/p-NF-κB p65、Iκκ-α/p-Iκκ-α表达下调(P<0.05),诱导促凋亡蛋白BAX/Caspase-3表达上调、抑凋亡蛋白BCL-2、细胞周期蛋白Cyclin D_1表达下调,NF-κB/IκB mRNA表达下调,凋亡相关mRNA BAX表达上调BCL-2表达下调。结论:PDTC可显著逆转由TGF-β2诱导的LECs细胞EMT过程,可能与抑制NF-κB信号通路活化使NF-κB p65/IκB/Iκκ-α表达降低以及激活凋亡相关蛋白表达有关,PDTC可通过抑制NF-κB信号通路达到逆转EMT的进程并使异常增殖的细胞发生凋亡,这将为后发性白内障的治疗提供新的潜在的治疗药物。

AIM:To investigate the mechanism of pyrrolidine dithiocarbamate(PDTC)on transforming growth factor-beta 2(TGF-β2)-induced epithelial-mesenchymal transition(EMT)in human lens epithelial cells(LECs).METHODS:LECs were treated with various doses of PDTC chemicals following TGF-β2 caused EMT on these cells.Cell proliferation and lateral migration were discovered using the CCK-8 and cell scratch test.The markers of EMT,including E-cadherin,α-SMA and nuclear factor-κB(NF-κB)signaling pathway-related expression,were tested by Western Blot as well as the changes in the expression of the apoptosis-related proteins BAX,BCL-2,Caspase-3,and Cyclin D_(1).RESULTS:The proliferation and migration viability of cells in the TGF-β2 treated group was increased compared to the group without TGF-β2,and the expression ofα-SMA increased whereas the E-cadherin expression decreased.With the effect of TGF-β2,NF-κB p65 and phosphorylated NF-κB p65 expression increased,the concentration of TGF-β2 that had the greatest capacity for proliferation and migration was 10 ng/mL(P<0.05).Mechanism study of PDTC-induced EMT reversal and apoptosis showed that cell viability and migratory capability were both significantly reduced after PDTC intervention;PDTC prevents IκB phosphorylation,thus inhibiting NF-κB nuclear translocation.Protein associated to the NF-κB signaling pathway,and protein expression of NF-κB/IκBα/p-IκBα/Iκκ-α/p-Iκκ-αwas decreased(P<0.05),PDTC increased the expression of the pro-apoptotic protein BAX/Caspase-3,expression of the inhibitor of apoptosis protein BCL-2 and the cell cycle protein Cyclin D_(1) was reduced.The expression of NF-κB/IκB mRNA was reduced,expression of the apoptosis-related mRNA BAX increased,while BCL-2 reduced.CONCLUSION:The EMT in LECs cells induced by TGF-β2 can be significantly reversed by PDTC,which may be related to the decreased expression of NF-κB p65/IκB/Iκκ-αand activation of apoptosis-related protein.PDTC can reverse EMT by inhibiting NF-κB signaling pathway and induce apoptosis of abnormally proliferated cells,which will provide new potential therapeutic agents for posterior capsular opacification(PCO)treatment.