维生素A调控DDR1介导的细胞自噬对孤独症大鼠神经行为学的影响

Effects of DDR1 mediated autophagy regulated by vitamin A on neurobehavior in rats with autism spectrum disorder

目的探究维生素A(vitamin A,VA)对丙戊酸钠(sodium valproate acid,VPA)诱导的孤独症大鼠神经行为学的影响及作用机制。方法将孕12.5 d大鼠分为对照组(Control)、模型组(Model)、VA组、DDR1抑制剂组(DDR1 inhibitor)、VA+DDR1过表达组(VA+OVE-DDR1),每组各10只。腹腔注射VPA(600 mg·kg^(-1))构建孤独症幼鼠模型。各组大鼠于出生后D28,自梳理实验检测大鼠重复刻板行为;三箱实验检测大鼠社交行为;Morris水迷宫检测大鼠学习记忆能力;HE染色和免疫组化染色检测海马神经元形态和表型;电镜观察自噬小体数量;Western blot检测DDR1及自噬标志性蛋白LC3和p62表达。结果与Control组相比,Model组大鼠社交及学习记忆能力减弱,重复刻板行为增加,海马CA1区神经元损伤加重,NeuN阳性细胞数量明显减少,DDR1、p62表达升高,LC3表达降低,自噬小体数量减少(P<0.01)。与Model组相比,VA组和DDR1 inhibitor组大鼠社交及学习记忆能力增强,重复刻板行为减轻,海马CA1区神经元损伤减轻,NeuN阳性细胞数量增加,DDR1、p62表达降低,LC3表达增加,自噬小体数量增加(P<0.01)。与VA组相比,OVE-DDR1能够逆转VA对孤独症大鼠的作用。结论VA能够改善孤独症大鼠神经行为,机制与抑制DDR1表达,增强细胞自噬相关。

Aim To investigate the effect of vitamin A(VA)on neurobehavioral changes in rats with autism induced by sodium valproate(VPA)and its mechanism.Methods Rats at 12.5 days of gestation were divided into control group,model group,VA group,DDR1 inhibitor group,and VA+OVE-DDR1 overexpression group,with 10 rats in each group.A young mouse model of autism was established by the intraperitoneal injection of VPA(600 mg·kg-1).On D28 after birth,rats in each group were tested for repetitive stereotypical behaviors through self grooming experiments.Three box experiment was used to detect the social behavior of rats.Morris water maze was used to test the learning and memory abilities of rats.HE staining and immunohistochemical staining were used to detect the morphology and phenotype of hippocampal neurons.The number of autophagic bodies was observed by electron microscopy.Western blot was used to detect the expression of DDR1 and autophagy marker proteins LC3 and p62.Results Compared with the control group,the social and learning and memory abilities of the model group decreased,repetitive stereotyping behaviors increased,neuronal damage in the hippocampal CA1 region was aggravated,the number of NeuN positive cells was significantly reduced,the expression of DDR1 and p62 increased,the expression of LC3 decreased,and the number of autophagic bodies decreased(P<0.01).Compared with the model group,the VA group and the DDR1 inhibitor group increased their social and learning and memory abilities,reduced repetitive stereotyping,reduced neuronal damage in the hippocampal CA1 region,increased the number of NeuN positive cells,decreased the expression of DDR1 and p62,increased the expression of LC3,and increased the number of autophagic bodies(P<0.01).Compared with VA group,OVE-DDR1 could reverse the effect of VA on autism rats.Conclusions VA can improve the neural behaviors in autism rats,and the mechanism is related to inhibiting the expression of DDR1 and enhancing autophagy.