Research Of The Effect Of Hyperglycemic On Retinal Ganglion Cells And Signaling Pathway In RPE And HREC

Part?The protective role of VEGF-B in ganglion cell apoptosis in STZ induced diabetic retinopathyAim:To investigate the neuroprotective role of VEGF-B in diabetic retinopathy. Methods:Diabetes were induced by a single intraperitoneal injection of STZ dissolved in 0.1 mol/L citrate buffered saline (pH 4.5) at a dosage of 50 mg/kg bodyweight. The rats were divided into 3 groups:1) Normal rats,2) Control group:Intravitreal injection of diabetic rats with BSA,500 ng per eye every five days, totally for 3 times.3) Experimental group:Intravitreal injection of diabetic rats with VEGF-B,500 ng per eye every five days, totally for 3 times.5 days after the last injection, the rats were killed, the eyes were enucleated embedded in OCT compound, frozen sections were cut. The sections were then stained with TUNEL and DAPI, Confocol microscope was used to photograph.Conclusions:Intravitreal injection of VEGF-B (500 ng/eye) every five days inhibited apoptosis, compared to BSA-treated group. The number of apoptosis cells in GCL was decreased nearly 50% after VEGF-B injection compared to BSA-treated.Part IIThe expression level of VEGF-B and its receptors and signaling pathway moleclues in RPE, HREC under high glucoseAim:To investigate the expression level of VEGF-B and its receptors under high glucose. Then further to explore the intracellular signaling pathway that activated by up-regulation of VEGF-B and its receptors.Methods:Cells were cultured in the medium contained either 5 mM [physiological, low D-glucose (LG)] or 40 mM [high glucose, high D-glucose (HG)]. Cells were divided into 2 groups:1) Control group:the cells were exposed to LG for 6 hours,24 hours, and 48 hours,2) Experimental group:the cells were exposed to LG for 6 hours,24 hours, and 48 hours. After culturing, harvest the medium and cell lysate. Western Blot analysis was used to detect the expression level of VEGF-B in both the medium and cell lysates, also its receptors and Src, Erk, Akt.Conclusions:1) High glucose can induce the expression of VEGF-B in both medium and cell lysates, also its receptors VEGFR1 and NP-1.2) High glucose can induce the expression of Akt, Erk in cell lysates.3) High glucose has no effect on the expression of Src in cell lysates. VEGF-B plays its nueroprotective role through signaling pathway moleclues, Akt and Erk, after binding with its receptors.