Effect Of The Electric Field On The Epithelial Mesenchymal Transition In Human Lens Epithelial Cells

PurposeThe posterior capsule opacification(PCO)is the most common postoperative complication after cataract surgery.PCO is mainly caused by migration,proliferation and epithelial mesenchymal transition(EMT)of remnant lens epithelial cells(LECs)after cataract surgery.The cataract surgery removes a large part of the anterior lens capsule and the lens nucleus,which changes the inward electrical currents at the anterior lens surface and significantly disrupts the normal electric current pattern.This abnormal electrical signal may trigger the LECs migration and proliferation,and the formation of PCO eventually.The purpose of this study was to establish the electric field(EF)-exposure model in HLE-B3 cells,and to investigate the effects of EF on the viability,proliferation and EMT of HLE-B3 cells,and the role of integrinβ1-focal adhesion kinase(FAK)signaling pathway in this process.MethodsCultured HLE-B3 cells were exposed to an EF at 100mV/mm for 6h,12 h and 24 h,respectively.Experiments were performed in the presence and absence of anti-integrinβ1 antibody and anti-FAK antibody.Cell morphology was observed under an inverted microscope.The expression of E-cadherin,Vimentin and integrinβ1 were examined by immunofluorescence.The mRNA levels of E-cadherin,Vimentin and integrinβ1 expression were evaluated with quantitative real-time polymerase chain reaction(qRT-PCR).The protein levels of E-cadherin,Vimentin,integrinβ1,FAK and phosphorylated-FAK(pFAK)were examined by Western blot.ResultsHLE-B3 cells were enlongated and changed into fibroblast-like cells after exposing to EF for 24 h.The expression of E-cadherin was decreased and that of Vimentin was increased in HLE-B3 cells as shown by immunofluorescence,mRNA and Western blot.Meanwhile,the mRNA expression of integrinβ1 was increased,and the protein expression of integrinβ1 and pFAK were increased as well.Blocking of integrinβ1 suppressed the morphologic change of HLE-B3 cells and reduced the activation of FAK in EF.On the other hand,blocking of pFAK did not show any effects on the changes of morphology of HLE-B3 cells or the expression of integrinβ1 protein induced by EF.Conclusions1)EF of 100mV/mm induced an epithelial-mesenchymal transition of HLE-B3 cells on morphology.With the exposure of EF,the proliferation of HLE-B3 cells was inhibited with a significant decrease of cell density,cell growth rate and mitosis index.EF also inhibited the cell cycle of the cells from phase G1 into phase S.2)EF induced EMT in HLE-B3 cells,with the upregulation of integrinβ1 and activation of FAK.3)The effect of EF on EMT of HLE-B3 cells may partially act through the activation of integrinβ1-FAK signaling.