The Effect Of Brain-derived Neurotrophic Factor On Diabetic Retinal Müller Cell

ObjectiveTo investigate the effect of Brain derived neurotrophic factor(BDNF)on retinal Müller cell in diabetic retinopathy.MethodsHealthy male SD rats,diabetic model was established by intraperitoneal one-time injection of streptozotocin(55mg/kg),preparation of BDNF injection with PBS balanced salt solution containing 0.1%BSA.The experiment was randomly divided into control group,diabetic group,BDNF group.Four weeks after the diabetes model was established,then BDNF group was injected BDNF injection.The control group and diabetic group were injected with equal dose of PBS balanced salt solution.After eight weeks and the success of the diabetes model,the determination of glutamate concentration in the retina and the content of MDA in the retina were detected by visible spectrophotometry and the use of glutamate content determination kit and lipid oxidation(MDA)detection kit.The expression of glial glutamate transporter(L-glutamate/L-aspartate transporter,GLAST),glutamine synthetase(Glutamine synthetase,GS)and synaptic vesicular membrane protein(synaptophysin,SYN)were detected by Immunofluorescence.The expression of GLAST?GS and caspase-3 protein were detected by immunoblotting.ResultsResults of retinal glutamate determination show that compared with the control group,glutamate concentration of rat retina increased significantly in diabetic group(P<0.01),there was no significant change between BDNF group and control group(P>0.05).Compared with the diabetic group,glutamate concentration in the retina was decreased significantly in BDNF group(P<0.01).Meanwhile,compared with the control group,the content of MDA increased significantly in diabetic group(P<0.01),there was no obvious difference between BDNF group and control group(P>0.05);Compared with the diabetic group,the content of MDA of retina was significantly decreased in BDNF group(P<0.01).The results of immunofluorescence detection show that compared with the control group,the expression of GLAST,GS and SYN protein decreased significantly in the diabetic group(P<0.01),compared with the control group,there was no statistically significant between BDNF group and control group(P>0.05);Compared with the diabetic group,the expression of GLAST,GS and SYN protein in group BDNF was significantly elevated(P<0.01).The results of Western blot detection combined with protein gray value analysis are show that compared with the control group,the expression of GLAST,GS and SYN protein decreased significantly in diabetic group,while the expression of caspase-3 increased significantly(P<0.01).,there was no obvious difference between BDNF group and control group(P>0.05);Compared with the diabetic group,the expression of GLAST,GS and SYN protein in BDNF group was significantly increased,the expression of caspase-3 decreased significantly(P<0.01).ConclusionIn the early stage of diabetes,BDNF can reduce the content of MDA and caspase-3 in retina,play an antioxidant role and improve the expression of GLAST and GS in retinal Müller cell,and decrease the glutamate concentration in reuna,meanwhile It can also improve the expression of SYN and protect retinal ganglion cells.However,it is not clear how BDNF can improve SYN expression,We still need further study and discussion.