AIM:ToinvestigatetheroleofRho-associatedproteinkinase(ROCK)inhibitor,Y27632,inmediatingtheproductionofextracellularmatrix(ECM)componentsincludingfibronectin,matrixmetallo-proteinase-2(MMP-2)andtypeIcollagenasinducedbyconnectivetissuegrowthfactor(CTGF)ortransforminggrowthfactor-β(TGF-β)inahumanretinalpigmentepithelialcellline,ARPE-19.METHODS:TheeffectofY27632ontheCTGForTGF-βinducedphenotypeinARPE-19cellswasmeasuredwithimmunocytochemistryasthechangeinF-actin.ARPE-19cellsweretreatedwithCTGF(1,10,100ng/mL)andTGF-β(10ng/mL)inserumfreemedia,andanalyzedforfibronectin,laminin,andMMP-2andtypeIcollagenbyRT-qPCRandimmunocytochemistry.CellswerealsopretreatedwithanROCKinhibitor,Y27632,toanalyzethesignalingcontributingtoECMproduction.·RESULTS:TreatmentofARPE-19cellsinculturewithTGF-βorCTGFinducedanECMchangefromacobblestonemorphologytoamoreelongatedswirlpatternindicatingamesenchymalphenotype.RT-qPCRanalysisanddifferentgeneexpressionanalysisdemonstratedanupregulationinexpressionofgenesassociatedwithcytoskeletalstructureandmotility.CTGForTGF-βsignificantlyincreasedexpressionoffibronectinmRNA(P=0.006,P=0.003respectively),lamininmRNA(P=0.006,P=0.005),MMP-2mRNA(P=0.006,P=0.001),COL1A1mRNA(P=0.001,P=0.001),COL1A2mRNA(P=0.001,P=0.001).PreincubationofARPE-19withY27632(10mmol/L)significantlypreventedCTGForTGF-βinducedfibronectin(P=0.005,P=0.003respectively),MMP-2(P=0.003,P=0.002),COL1A1(P=0.006,P=0.003),andCOL1A2(P=0.006,P=0.004)geneexpression,butnotlaminin(P=0.375,P=0.516).CONCLUSION:OurstudydemonstratedthatbothTGF-βandCTGFupregulatetheexpressionofECMcomponentsincludingfibronectin,laminin,MMP-2andtypeIcollagenbyactivatingtheRhoA/ROCKsignalingpathway.Duringthisprocess,ARPE-19cellswereshowntochangefromanepithelialtoamesenchymalphenotypeinvi
