Protective Effect Of RbFGF On Retinal Ganglion Cells Via Notch1 Signaling Pathway In Diabetic Rats

ObjectiveTo investigate the protective effect of recombinant basic fibroblast growth factor（rbFGF）on retinal ganglion cell（RGC）in diabetic rats via Notch1signaling pathway.MethodsTotally 40 male SD rats were randomly divided into control group,diabetic group,rbFGF group,rbFGF+DAPT group（DAPT is a specific antagonist of Notch1 pathway）,10 rats in each group.The diabetic rats in the latter three groups were induced by single intraperitoneal（IP）injection of streptozotocin（STZ）(55 mg·kg^-1).After successful induction of the model,rbFGF group was given intravitreal injection of rbFGF 10μl（200U）,while rbFGF+DAPT group was given DAPT(10μmol·L^-1)on the basis of rbFGF.After12 weeks of injection,the density of RGC was detected by HE staining,the protein expression of growth associated protein-43（GAP-43）and Notch1 was detected by immunohistochemical staining,and relative protein expression of GAP-43,Notch1 and Caspase-3 was detected by Western blot.ResultsCompared with the density of RGC（433.49±6.02）(cells·mm^-2)and the protein expression of GAP-43（8.96±0.26）%,Notch1（45.04±0.46）%,Caspase-3（27.91±0.63）%in control group,the density of RGC（328.35±6.43）(cells·mm^-2)and the protein expression of Notch1（31.66±0.40）%were decreased significantly,the protein expression of GAP-43（13.66±0.52）%,Caspase-3（48.91±0.64）%in diabetic group were increased significantly（all P<0.05）.Compared with diabetes group,the density of RGC（425.30±7.98）(cells·mm^-2)and the protein expression of GAP-43（33.05±0.37）%、Notch1（41.76±0.62）%were increased significantly,the protein expression of Caspase-3（28.86±0.71）%in rbFGF group was decreased significantly（all P<0.05）;but the density of RGC（324.91±8.22）(cells·mm^-2),theproteinexpressionof GAP-43（14.27±0.64）%,Notch1（30.40±0.82）%and Caspase-3（47.63±0.68）%in rbFGF+DAPT group were no significant change（all P﹥0.05）.ConclusionRbFGF can up-regulate the protein expression of GAP-43 and down-regulate the protein expression of Caspase-3 in the retina of diabetes rats and thus improving the survival of RGC.The mechanism may be related to activation of Notch1 signaling pathway.