自噬作用在早产儿视网膜病变大鼠病情进展中的调控作用及相关机制研究

目的探讨自噬作用在早产儿视网膜病变大鼠病情进展中的调控作用及相关机制。方法20只SD大鼠随机选取10只孕鼠正常分娩,不做任何特殊处理,待其顺利分娩后选取20只足胎龄幼鼠进行下一步实验;另取10只孕鼠采用脂多糖(LPS)制备早产模型,诱导孕鼠早产,取20只早产幼鼠。将所得幼鼠平均分为正常分娩+空气组、正常分娩+视网膜病变组、早产+空气组、早产+视网膜病变组,每组各10只。对比分析各组大鼠视网膜无血管区和新生血管区面积大小、视网膜血管内皮生长因子(VEGF)和胰岛素样生长因子1(IGF-1)表达水平以及白细胞介素-1β(IL-1β)和白细胞介素-6(IL-6)含量;同时检测幼鼠视网膜组织中自噬小体数量、自噬相关蛋白和Akt、p-Akt、mTOR、p-mTOR蛋白表达水平。结果相较于正常分娩+空气组,正常分娩+视网膜病变组、早产+空气组、早产+视网膜病变组血管区和新生血管区面积、VEGF和IGF-1 mRNA表达水平、IL-1β和IL-6含量和P62、Akt、p-Akt、mTOR、p-mTOR蛋白表达水平均有所上调,自噬小体数量和自噬相关蛋白Beclin-1、LC3-Ⅱ和ATG5表达水平则有所下降,尤其是以早产+视网膜病变组最为显著(P<0.05)。结论早产儿视网膜病变大鼠病情进展与视网膜组织自噬活性降低有关,且作用机制可能通过Akt-mTOR信号通路调控自噬相关蛋白表达而实现。

Study on the regulation effect of autophagy on the progression of retinopathy of prematurity in rats and its related mechanism

Objective To investigate the regulation effect of autophagy on the progression of retinopathy of prematurity in rats and its related mechanism.Methods Twenty SD rats were randomly selected from 10 pregnant rats to give birth normally without any special treatment.After the smooth delivery,20 pups of full gestational age were selected for the next experiment;another 10 pregnant rats were taken with lipopolysaccharide(LPS)premature delivery model was prepared to induce premature delivery in pregnant mice,20 premature pups were selected.The young rats were divided into three groups:normal delivery+air group,normal delivery+retinopathy group,premature delivery+air group,and premature delivery+retinopathy group,each group 10 pregnant rats.The size of retinal no-vessel area and neovascularization area,the expression levels of retinal vascular endothelial growth factor(VEGF)and insulin-like growth factor 1(IGF-1)mRNA,and interleukin-1β(IL-1β)and interleukin-6(IL-6)were compared and analyzed in each group.At the same time,the number of autophagosomes,autophagy-related proteins and the expression levels of Akt,p-Akt,mTOR and p-mTOR in retinal tissue of young mice were detected.Results Compared with normal delivery+air group,blood vessels and angiogenesis area,the levels of VEGF,IGF-1 mRNA expression,and the content of IL-1β,IL-6,levels of P62,Akt,p-Akt,mTOR,p-mTOR protein expression raised,the number of autophagosomes and the levels of autophagy-related proteins Beclin-1,LC3-Ⅱand ATG5 expression decreased decreased in normal delivery+retinopathy group,premature delivery+air group,and premature delivery+retinopathy group,especially premature+retinopathy group in the most significant(P<0.05).Conclusion The progression of retinopathy of prematurity in rats is related to the decrease of autophagy activity in retinal tissue,and the mechanism may be realized through the regulation of autophagy-related protein expression by Akt-mTOR signaling pathway.