AIM:ToexplorethemolecularmechanismsinlensdevelopmentandthepathogenesisofPetersanomalyinSmad4defectivemice.METHODS:Le-CretransgenicmouselinewasemployedtoinactivateSmad4inthesurfaceectodermselectively.PathologicaltechniqueswereusedtorevealthemorphologicalchangesoftheanteriorsegmentinSmad4defectiveeye.ImmunohistochemicalstainingwasemployedtoobservetheexpressionofE-cadherin,Ncadherinanda-SMAinanteriorsegmentofSmad4defectivemiceandcontrolmiceatembryonic(E)day16.5.Real-timequantitativepolymerasechainreaction(qPCR)wasperformedtodetecttheexpressionofSnail,Zeb1,Zeb2andTwist2inlensofSmad4defectivemiceandcontrolmiceatE16.5.RESULTS:ConditionaldeletionofSmad4oneyesurfaceectodermresultedincorneaidysplasia,iridocornealangleclosure,corneolenticularadhesionsandcataractresemblingPetersanomaly.LossofSmad4functioninhibitedE-cadherinexpressioninthelensepitheliumcellsandcorneaiepitheliumcellsinSmad4defectiveeye.ExpressionofN-cadherinwasupregulatedincorneaiepitheliumandcorneaistroma.BothE-cadherinandN-cadherinweredown-regulatedatthefuturetrabecularmeshworkregioninmutanteye.TheqPCRresultsshowedthattheexpressionofTwist2wasincreasedsignificantlyinthemutantlens(P<0.01).CONCLUSION:Smad4isessentialtoeyedevelopmentandlikelyacandidatepathogenicgenetoPetersanomalybyregulatingepithelial-mesenchymaltransition.Twist2canberegulatedbySmad4andplaysanessentialroleinlensdevelopment.
