Study On The Effect And Mechanism Of CREG Inhibitting The Light Injury Photoreceptor Apoptosis In Rat Retina

Objective:To study the influence of CREG protein on inhibiting light injury in retina photoreceptor cells of rats,to evaluate its anti-apoptosis ability and to explore the anti-apoptosis mechanism of CREG in light injured photoreceptor cells.Methods: 1.Making models: 30 healthy wistar rats of either gender were selected and divided into 3 groups randomly: the control group,one-week illumination group and two-week illumination group,with 10 rats in each group.HE staining was carried out on the frozen sections of rat eyes from three groups.2.The established model was one-week illumination group and the retinal protein of rats from one-week illumination group and the control group was extracted.Western blotting was carried out to detect the expression of key protein ERK,P38,JNK and MAPK signaling pathway and their phosphorylation expression amount.3.Thirty wistar rats were randomly divided into 3 groups,which were D1 group(1day after injecting),D3 group(3days)and D7 group(7 days),with 10 rats in each group.Light injury models were prepared.After preparation,4?l CREG protein and 4?l PBS were injected into vitreous chambers of light and right eyes of rats.Rat eyes were obtained at 1d,3d and 7d after injection for making frozen sections and conducting HE staining.Retinal protein of rats was extracted and Western blotting was used to detect the expression amount of apoptosis factor casepase3,8,9 in the retinal protein of rats.4.Western blotting was used to detect the expression of key protein P38,JNK,AKT in MAPK apoptosis pathway and PI3K/AKT pathway and their phosphorylation expression.Vitreous chamber injection was carried out on CREG protein eyes of rats from D3 group with P38 inhibitor SB203580,JNK inhibitor SP600125 and AKT inhibitor LY2940002,with the dose of 4?l;PBS of the same dose was injected in rats from the control group.The expression condition of Caspase3 of two groups was detected using western blotting.Results: 1.The retinal outer nuclear layer cell of one-week illumination group was thinner than that of the control group while the retinal outer nuclear layer cell of two-week illumination group disappeared.2.The expression amount of p-P38,p-JNK in the retinal protein of rats from one-week illumination group was evidently higher than that of the control group(P < 0.001)and the expression amount of P38,JNK,ERK,p-ERK had no evident change compared with the control group.3.The retinal outer nuclear layer cellapoptosis of CREG protein D3 group was less than that of the control group while there was no evident change in D1 group and D7 group.4.p-JNK,p-P38 of rats from CREG protein D3 group were evidently less than that of the control group(P < 0.001),p-AKT expression amount increased evidently(P < 0.001).There was no evident change in D1 group and D7 group compared with the control group.5.The expression amount of Caspase3 in P38,JNK and AKT inhibitor injection group increased evidently compared with the control group(P < 0.001).Conclusions: 1.The apoptosis of light-induced retinopathy photoreceptor cells can be medicated by key protein P38,p-P38 and JNK,p-JNK in MAPK signaling pathway.2.After injecting vitreous chamber of rats with CREG protein,the 3-day group can inhibit the apoptosis of photoreceptor cells.3.CREG can adjust the expression of key proteins p-JNK,p-P38,p-AKT protein in MAPK and PI3K/AKT signaling pathway to inhibit the apoptosis of light injured cells.