Expression Of Connective Tissue Growth Facor And Fibronectin In Epiretinal Membranes

Objective To investigate the components of PVR and PDR epiretinalmembranes(ERMs) and the expression of connective tissue growth facor(CTGF) andfibronectin(FN) in them, and to explore the relationship between CTGF and FN.Methods 45 epiretinal membranes were obtained through vitrectomy. They weredivided into PVR and PDR groups. And meanwhile in these 45 specimens, ERMswhich lasted for less than 6 months and more than 6 months were also discussed.Immunohistochemistry was used to detect the expression of CTGF and FN in ERMs.And x~2 test was used to detect whether there was a significance in CTGF and FNexpression respectively between PVR and PDR epiretinal membranes and betweenmembranes which lasted for less than 6 months and more than 6 months. Thecorrelation between the expression of CTGF and FN in all specimens was analyzedbySpearman.Results The membranes contained RPE cells; fibroblast-like cells,macrophage-like cells; garanulocytes and lynphocytes. CTGF was highly expressedin the epiretinal membranes, and most of the CTGF-positive cells were epithelioidcells and mesenchymal cells. No statistical significance was found in CTGFexpression between PVR and PDR groups and between epiretinal membranes whichlasted for less than 6 months and more than 6 months. FN was extensively expressedin the membranes. There was no statistical significance in FN expression betweenPVR and PDR groups. But its expressive level was lower in specimens which lastedfor more than 6 months. Statistical analysis showed a correlation between theexpression of CTGF and FN in all specimens. Conclusion Although PVR and PDR have different causes, the ERMs formed inthese two situations undergo the same pathological process including inflammationphase, proliferation phase, and cicatrix phase. ERM is a result of excessive repair, aprocess of inflammation and immunoreaction induced by intraocular injury anddegeneration. CTGF and FN are highly expressed in ERMs of PVR and PDR. Thesetwo factors can promote cell migration and differentiation, increase the bioactivity ofcells, and lead to cell proliferation. The correlation between CTGF and FN expressionsuggests that CTGF can stimulate RPE cells to synthesis of FN, which plays a criticalrole in the formation of ERMs. Therefore, to inhibit the expression of CTGF mayblock the synthesis of ECM components and thus prevent or postpone the formationof ERMs.