The role and function of matrix metalloproteinase-8 in rhegmatogenous retinal detachment

Rhegmatogenous retinal detachment (RRD) is one blinding disease, and has pathological features correlated with migration of retinal pigment epithelium (RPE) cells to viscous body. Matrix metalloproteinase-8 (MMP-8) participates in eye diseases including xerophthalmia and retinal disease. Its role in RRD, however, has not been illustrated with the functional mechanism. RPE cells from RRD model mice and normal mice were separated and cultured. MMP-8 expression plasmid was transfected into RPE cell in model group. Real time PCR and Western blot were employed to test expression level of MMP-8, whilst MTT method was used to test proliferation activity of RPE cells. Caspase 3 activity was quantified by test kit. Transwell migration assay was adopted to measure invasion ability of RPE cells. ELISA method was used to test expression level of inflammatory factors interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). MMP-8 expression level was significantly decreased in RPE cells of RRD group, which also had enhanced cell proliferation and migration, accompanied with higher IL-1β and TNF-α levels (P<0.05 compared to control group). After MMP-8 transfection and over-expression, RPE cell proliferation and migration were inhibited, along with higher Caspase 3 activity, plus lower IL-1β and TNF-α expression (P<0.05 compared to model group). RRD caused decreased expression of MMP-8 in RPE cells. MMP-8 can facilitate RPE cells proliferation and migration via modulating cell apoptotic activity and secretion of inflammatory factor, thus participating in RRD pathogenesis and progression.