| Objegtive:To simulate the animal model of dry AMD by tail vein injection of 1%sodium iodide in PBS in BN rats as the research object,and to observe the status of cell autophage in the animal model of oxidative damage of RPE at various time points after the animal model.To observe whether Mingmu Dihuang,a Chinese medicine,has an intervening effect on the autophagy and apoptosis of RPE cells in animal model,and to evaluate its effect on experimental model,in which Mingmu Shuihuang was intervened to regulate autophagy through mTOR pathway,so as to provide inj ury protection.Methods:Ninety(90)BN rats were randomly divided into Chinese medicine group,model group,and blank group,with 30 rats each.After 1 week of adaptive feeding,the Chinese medicine group and model were given a tail intravenous injection of 1%sodium iodate(40 mg/kg).The Chinese medicine group began the oral administration on the first day after the start of the experiment,with Mingmu Dihuang Pill by gavage once a day,according to body weight,by gavage 12 g/kg,until the end of the experiment.The blank and model group were given normal saline by gavage once a day and given a dose of 12 g/kg by weight on the first day after the start of the experiment until the end of the experiment.The rats were euthanized by overdose of chloral hydrates at 1,7,and 14 days after modeling(10 per group at each time period),and the eyes were removed intact and retinal tissue specimens were dissected.The histological changes of the retina and photoreceptors were observed by HE staining;the protein expression of p-mTOR?LC3-II and Caspase-3 were detected in each group by Western-Blot.Results:Sodium iodate injection can successfully produce oxidatively injured rat retina model.The changes of retinal structure,pigment epithelial deposits and damage of the inner and outer nuclear layer cells were observed by HE staining,which proved that the dry AMD animal model of the rat omentum was successfully established.Compared with the normal blank group,the retinal pigment epithelial damage of the model group was thickened,the outer nuclear layer structure was damaged,the arrangement was disordered,and the inner and outer nuclear layers changed wavy with time.And compared with the model group,the retinal pigment epithelium and the inner and outer nuclear layer structure of the administration group gradually recovered.Compared with the 1-day blank group,the expression level of p-mTOR protein was down-regulated(P<0,05),the expression level of LC3-? protein was up-regulated(P<0.05),and the expression level of Caspase-3 protein was increased(P<0.05).The expression of p-mTOR protein was increased in the 7-day and 14-day model groups compared with the blank group(P<0.05),while the expression level of LC3-? protein was down-regulated(P<0.05),and the expression level of Caspase-3 protein was increased(P<0.05);Compared with the 1-day model group,the expression levels of p-mTOR,LC3-? and Caspase-3 in the traditional Chinese medicine group did not change significantly,and the difference was not statistically significant(P>0.05).Compared with the 7-day and 14-day model groups,the expression of p-mTOR protein in the Chinese medicine group decreased(P<0.05),and the expression of Caspase-3 protein decreased significantly(P<0.05).Conclusion:By observing the changes of retinal tissue structure,the lipid deposits in the pigment epithelial layer and the degree of damage of the inner and outer nuclear layer cells,it is indicated that the tail vein injection of sodium iodide can cause oxidative damage in the rat retinal pigment epithelium,and the dry AMD model was successfully modeled.Acute oxidative damage(1 day)decreased the activity stress of mTOR pathway,increased the stress of autophagy activity,and aggravated the apoptosis of cells,but the activity of mTOR pathway gradually increased during chronic oxidative injury(7 days,14 days).However,the autophagy activity of cells gradually decreased,and apoptosis was inhibited to some extent.This may be a regulatory mechanism for cells to maintain their homeostasis without drug intervention.In the early stage of acute injury of oxidative damage model,Mingmu Dihuang Pill has limited efficacy and has no obvious effect on autophagy and apoptosis of RPE cells.When taking Mingmu Dihuang Pills for a certain course of treatment(7 days,14 days),it can promote the autophagy of RPE cells,and can maintain the autophagy of cells at a relatively high level for a certain period of time,and have an inhibitory effect on apoptosis.At the same time,Mingmu Dihuang Pill can inhibit the activity of mTOR pathway,enhance the autophagy activity of RPE cells,reduce the oxidative damage of RPE cells,and maintain cell homeostasis. |
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