The Effect Of Adiponectin On Human Retinal Pigment Epithelial Cells Under High Glucose

Background: Diabetic retinopathy (diabetic retinopathy,DR) is one of the most common and most serious microvascular complications of diabetes mellitus (DM) and has become the leading cause of blindness in the most developed countries. Retinal pigment epithelial (RPE) cells located between the retina feeling and choroid layer which constitutes the retina outside the barrier. Pathological studies showed that RPE cells involved in pathological changes of the late DR and aroused pathological intraocular neovascularization. Adiponectin are a recently discovered adipocyte-secreted by the specific protein. Clinical and basic studies have shown that adiponectin is closed to the happen and development of DR. In this study, the adoption of adiponectin on the RPE cell secretion of VEGF and PEDF effects of DR is to investigate the occurrence and development of its role, and may provide a new way for the treatment of DR. Objective: To investigate the effects of adiponectin on proliferation and the expression of vascuar endothelial growth factor(VEGF) and pigment epithelium derived factor(PEDF) of human retinal pigment epithelial (hRPE)cells cultured with high glucose in vitro.Methods: The hRPE cells were divided into four groups : normal glucose group (5.5 mmol/L glucose) , mannitol group ,high glucose group (33 mmol/L glucose) , high glucose plus adiponectin group (33 mmol/L glucose+ 2.5ug/ml adiponectin). 48h later, the cell proliferation was observed by MTTassay .Then the hRPE cells were divided into three groups:normal glucose group (5.5 mmol/L glucose,NG) , high glucose group (33 mmol/L glucose, HG) , high glucose plus adiponectin group(33 mmol/L glucose plus adiponectin: 2.5, 5, 10, 20μg/ml). 48 hours later, the level of VEGF and PEDF was measured by enzyme-linked immunosorbent assay (ELISA).Results:There was no significant difference in cell viability between Mannitol group and the control group(P> 0.05). High glucose group inhibits hRPE cell activity, high glucose group cell viability was significantly lower than the control group (P <0.01); Adiponectin intervention later, the cell viability of adiponectin group compare with high glucose group and the control group significantly increased, the difference had statistical significance ( P <0.01). Compared with normal glucose group ,the VEGF level significantly increased and PEDF significantly decreased in high glucose group. 2.5μg/ml diponectin has little effect on levels of VEGF and PEDF. Compared with high glucose group , the VEGF level significantly decreased and PEDF significantly increased in high glucose plus adiponectin group (5～20μg/ml),the difference has statistical significance (P <0.01).Conclusion: High glucose significantly decreased the cell viability of hRPE cell, damage hRPE cell function, and can lead to increase VEGF secretion of hRPE cells and decrease PEDF then take part in DR; adiponectin can promote hRPE proliferation, reducing cell damage; physiological concentration (5 ~ 20μg/ml) adiponectin correct high glucose-induced levels of VEGF and PEDF Change and can reduce the secretion of VEGF and increased PEDF secretion. Adiponectin may play a protective role in hRPE cell injury, which could rectified cell dysfunction of hRPE caused by high glucose, by regulating the balance between VEGF and PEDF to inhibit diabetic retinopathy (DR) pathological neovascularization formation, in order to clinical application of adiponectin treatment of DR to provide a theoretical basis.