Specific role of lymphatic marker podoplanin in retinal pigment epithelial cells

Podoplanin is a small transmembraneglycoprotein widely known to be a marker forlymphatic endothelial cells. In this study, weidentify a novel localization of podoplanin inthe retinal pigment epithelium (RPE), acellular monolayer critically involved in thevisual process. Using a small interfering RNA(siRNA)-mediated gene silencing approach,we have also demonstrated, for the first time,that podoplanin depletion in human RPEcells leads to a marked reduction of cellaggregates and tight junctions. Additionally,the podoplanin-depleted cells also exhibit asignificantly lower rate of proliferation. Thesedata together indicate that podoplanin plays acrucial role in RPE cell functions. Furtherinvestigation on this factor may reveal novelmechanisms and therapeutic strategies forRPE-related eye diseases, such as proliferativeretinopathy and age-related maculardegeneration.