Molecular Mechanism Of MTOR Signaling Pathway Mediated By TGF-β Induced Posterior Capsular Opacification

Objective: To investigate the role and mechanism of mTOR signaling pathway in TGF-β2 induced epithelial mesenchymal transition of lens epithelial cells and the effect of TGF-β2 on the endoplasmic reticulum stress and apoptosis of human lens epithelial cells,which will provide the theoretical basis for the prevention and treatment of posterior cataract.Methods: 1.Cell phenotypic changes were observed by microscopy.2.Western blot was used to further verify the epithelial mesenchymal transition model of HLEB3 induced by TGF-β2.3.MTT was applied to determine the effects of Rapamycin on cell proliferation in TGF-β2 induced epithelial mesenchymal transition cell model.4.Western blot was used to analyze the molecular relationship between mTOR signaling pathways and epithelial mesenchymal transition.5.Human lens epithelial cells were treated with different concentrations of transforming growth factor β2,and their subsequent effect on cell proliferation,endoplasmic reticulum stress and apoptosis associated markers were investigated.Results: 1.After incubation with TGF-β2 for 24 h,the morphology of HLEB-3 was changed from elliptical to stellate or spindle-shaped,and the connection between cells was decreased.2.Western blot showed that the expression of E-cadherin in HLEB-3 was significantly decreased after treatment with TGF-β2,while the expression level of interstitial cell marker protein α-SMA was apparently increased,and the difference was statistically significant.3.The result of MTT showed that rapamycin pretreatment can inhibit TGF-β2 induced epithelial cell proliferation.4.Western blot showed that Rapamycin can reverse the TGF-β2 induced increases of α-SMA and can promote the expression of epithelial protein marker E-cadherin.5.The corresponding OD values were(0.519 ± 0.017),(0.459 ± 0.015),(0.357 ± 0.022),(0.340 ± 0.028),and SR were 100%,81.46%,61.79%,58.57%,when the cells were treated with TGF-β2 at the concentration of 0,100,200,500ng/m L separately.The difference of OD value and SR values were statistically significant(P <0.05).Furthermore,the cells were treated with increasing TGF-β2 concentration,the expression of caspase-3 and GRP78 increase,while the expression rate of Hrd1 decline.These data were statistically significant(P <0.05).Conclusion: TGF-β2 promotes the proliferation and epithelial transformation of human lens epithelial cells by activating mTOR signaling pathway,indicating that TGF-β2 may regulate the occurrence and development of posterior capsular catheters through mTOR signaling pathway.