Effects Of KBP On Axonal Regeneration And Protection Of Rats Retinal Ganglion Cells Following Optic Nerve Incomplete Injury

Aim:In the diabetic rat model,kallikrein-binding protein(KBP) was detected expression reduced in vitreous cavity and the retinal tissue.The previously research proposed KBP may prevent the progress of diabetic retinopathy,even has the same protective effect of retinal ganglion cells as its homologous protein pigment epithelium-derived factor(PEDF) by cultivated a variety of eye tissue cells in vitro.Based on these studies,we explored whether KBP exists to protect retinal ganglion cells(RGCs) or promote regeneration of axon in vivo.Methods:1.To crush optic nerve at 0.5-1.0mm away from the eyeball for an incomplete injury of the rat optic nerve:2.In the rat model of optic nerve injury,we inject 5μl kallikrein-binding protein (concentration 3mg/ml) into vitreous cavity as a experimental group and 5μl of PBS as a control group:3.Follow the experiment,the rats were killed in 7d.14d and 21d after injury.The eyeballs were token off.The frozen sections were made for HE staining to observe the structure of retinal,measure the thick of retina and count the number of survival RGCs.The rat optic nerves were collected to extraction protein for Western blot analyse to determining whether KBP has protective function to retinal ganglion cells and promote regeneration of axon.Results:1.After optic nerve incomplete injury,rats were injected 5μl KBP(3mg/ml) and PBS in experimental group and control group respectively.Postoperative,we found the structural of the retinal integrity and blood supply normal,and without inflammatory response.Marcus Gun's sign were obvioused in the experimental rats.Optic nerve injury rat model was successful.2.On HE staining,we observed the structural changes in the all levels of the retina.The double-blind RGCs counting and retinal thickness measurement showed the statistical significance differences between the groups.3.We measured the expression of the nerve regeneration marker protein GAP-43 by Western-blot.The statistical signify can were showed between the inter-group.Conclusion:1.KBP has effect of protective RGCs after optic nerve injury.2.KBP may promote regeneration of optic nerve axon after injury.The further experiment need to determining how it works.