| Optic nerve is an integral part of the central nervous system.Because of its embryonic origin and cell composition,optic nerve regeneration after injury will become extremely difficult.Most patients with traumatic optic neuropathy,degenerative optic neuropathy,or ischemic optic nerve injury will suffer irreversible vision damage or even blindness.Therefore,studies that promote regeneration of optic nerve injury are important for improving patient vision and enhancing life confidence.The beginning of the optic nerve is the optic disc and it collects a large number of axons of retinal ganglion cells(retinal ganglioncells,RGCs).RGCs is the sole retinal visual output cells,so the study of optic nerve regeneration focused on how to retain more RGCs after optic nerve injury,how to prolong RGCs axons,how to restore visual contact and function.Optic nerve is an integral part of the central nervous system.Because of its embryonic origin and cell composition,optic nerve regeneration after injury will become extremely difficult.Most patients with traumatic optic neuropathy,degenerative optic neuropathy,or ischemic optic nerve injury will suffer irreversible vision damage or even blindness.Therefore,studies that promote regeneration of optic nerve injury are important for improving patient vision and enhancing life confidence.The beginning of the optic nerve is the optic disc and it collects a large number of axons of retinal ganglion cells(retinal ganglioncells,RGCs).RGCs is the sole retinal visual output cells,so the study of optic nerve regeneration focused on how to retain more RGCs after optic nerve injury,how to prolong RGCs axons,how to restore visual contact and function.ObjectivesTo explore the mechanism of promoting the regeneration of optic nerve with lens injury from the study of PKC and NF-kappa B after optic nerve injury,confirm the protection of PKC and NF-?B for retinal ganglion cells,and provide new effective targets and ideas in clinical treatment.MethodSixty healthy Wistar male rats were randomly divided into four groups: normal control group,6 rats(Group A),sham operation group,18 rats(Group B),optic nerve crush injury group,18 rats(Group C),optic nerve crush injury combined with lens injury group,18 rats(Group D).6 rats were executed after seven normal days and 6 rats every time point in Group B,Group C and Group D were executed at 7 days,14 days and 21 days after operation.2 rats were observed and counted after retrograde labeling with fluorescent gold;2 rats were tested the activity of PKC with(3H)PDBu;2 rats were used to detect the NF-?Bp65 expression.Results 1 Rat retinal ganglion cells labeled by fluorescent goldThe labeled RGCs were observed under inverted microscope,and the RGCs were golden,round or oval,clear boundary with certain morphological characteristics.The RGCs in Group A and B were stable at all time points.The distribution of RGCs gradually became sparse,the shape of RGCs became rounded,the coloration of the RGCs increased,and the swelling or disappearance of the axons increased with the injury time.The percent of RGCs in Group B was statistically significant compare with Group C and Group D at the same time point(P <0.05),the percent of RGCs in Group D at the same time point were higher than in Group C(P <0.05),there was no significant difference between Group A and Group B(P> 0.05).2 Comparison of PKC activation levels in each groupThe activity of PKC activation in group A and group B was stable.The activity of PKC was increased in Group C and Group D at section 7days,section 14 days and section 21 days after injury.The activity of PKC was significantly increased at 7 days after optic nerve injury,reached a high point at 14 days,remain a high level at 21 days.There was no significant difference in PKC activity between Group B and Group A at section 7 day,section 14 days and section 21 days after optic nerve injury(P> 0.05).The activity of PKC in Group C and Group D was significantly higher than that in Group B at the same time point(P <0.05).At the same time point,the activity of PKC in Group D was higher than that in Group C,and the difference was statistically significant(P <0.05).3 Comparison of expression of NF-?B p65 in each groupThe difference between Group A and Group B in the expression of NF-?Bp65 was not statistically significant(P> 0.05).The expression of NF-?B p65 protein in Group C and Group D was increased a high point after section 14 days of optic nerve injury and declined in succedent time.At the same time point,the expression of NF-?B p65 in Group C was higher than in Group D,and the difference was statistically significant(P <0.05).Conclusions1.With the prolongation of the damage time of optic nerve injury,RGCs count and labeling rate decreased,PKC activation and NF-?Bp65 began to decline in succedent time after reaching a highest point.2.Lens damage can increase the activity of PKC and decreace the expression of NF-?Bp65 after optic nerve injury.3.PKC and NF-?B may be involved in the mechanism of lens damage to protect ganglion cells after optic nerve injury. |
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