Abstract
Purpose: :
Proliferative vitreoretinopathy (PVR) is a well known complication of ocular trauma and rhegmatogenous retinal detachment leading to progressive deterioration of vision and potential blindness. Although several cell types and cytokines have been detected in PVR membranes their definite pathogenic mechanisms are still unknown. Members of the CCN family of matricellular proteins are multifunctional growth factors representing a novel class of extracellular matrix-associated signalling molecules. Several studies demonstrated that members of the CCN family are involved in the control of cell adhesion, chemotaxis, cell migration and cell proliferation. In particular, it was demonstrated that CTGF, CYR61 and NOV possess fibrotic and angiogenic activity being involved in wound healing and several fibrotic diseases. The aim of the present study was to investigate whether CCN proteins are expressed and increased in epiretinal membranes to shed more light on the pathogenesis of PVR
Methods: :
16 epiretinal membranes were surgically removed from eyes with PVR undergoing pars plana vitrectomy and membrane peeling. All PVR cases were grade C2 or worse. Immunohistochemistry was performed using the streptavidin-biotin-peroxidase method and highly specific antibodies against CTGF, CYR61 and NOV.
Results: :
Strong expression of CTGF and CYR61 was found on pigment epithelial cells (PEC), fibroblasts and macrophages in all epiretinal membranes while immunostaining of NOV was weaker, detected particularly on PEC and on fibroblasts. In addition, CTGF expression was also detected in the extracellular matrix of several membranes .
Conclusions: :
The results of the present study demonstrate that CCN proteins are expressed in PVR membranes. The strong expression of CTGF and CYR61 on fibroblasts, and pigment epithelial cells in all membranes strongly suggest that both molecules may be involved in the pathogenesis of PVR particularly in tissue remodeling, scar formation and fibrosis.
Keywords: proliferative vitreoretinopathy • immunohistochemistry • cytokines/chemokines