内源性大麻素系统对丙戊酸诱导的模型鼠孤独症样行为的影响研究

目的 探讨花生四烯酸甘油酯(2-AG)水平改变对VPA鼠孤独症样行为的影响,为进一步明确孤独症谱系障碍(ASD)病因及发病机制提供依据。方法 以VPA诱导ASD模型鼠为研究对象,将实验鼠分为CON组、VPA组、JZL184急性干预组:VPA+40 mg/kg JZL184组(VPA+40AJ)、JZL184慢性干预组:VPA+1 mg/kg JZL184组(VPA+1RJ)、VPA+3 mg/kg JZL184组(VPA+3RJ)和VPA+10 mg/kg JZL184组(VPA+10RJ)。检测各组大鼠的孤独症样行为,采用液相色谱-质谱联用技术检测大鼠海马组织中内源性大麻素(eCBs)水平,采用Western blot检测eCB系统相关受体及代谢酶表达水平。结果 VPA组2-AG、AEA水平显著低于CON组(P<0.05),JZL184 干预后,VPA+3RJ 组和 VPA+10RJ 组 2-AG 水平显著升高(P<0.05)。与CON组相比,VPA组埋珠数量、自梳时间及自发活动明显增多,同时社交能力指数和社交偏好指数降低(P<0.05);JZL184干预后,VPA+40AJ组的埋珠个数、自梳时间、自发活动均减少,社交能力指数和社交偏好指数明显增加;VPA+1RJ组的自梳时间减少;VPA+3RJ组的埋珠个数、自梳时间、自发活动均减少,社交偏好指数明显提高;VPA+10RJ组埋珠个数和自梳时间减少,社交偏好指数明显增加(P<0.05)。VPA组海马组织中CB1R、DAGL、MAGLFAAH蛋白表达显著高于CON组(P<0.05)。JZL184干预后,VPA+3RJ组 DAGL和MAGL的蛋白表达显著下调,VPA+10RJ组MAGL也显著下调(P<0.05)。结论 低eCBs信号与VPA鼠孤独症样行为有关,升高2-AG水平可以改善ASD模型鼠的重复刻板行为、活动过度和社交功能损伤。

Effects of endocannabinoid system on autistic behavior in valproic acid-induced rats

Objective To investigate the effect of altered 2-arachidonoylglycerol(2-AG) levels on autistic behaviors in VPA-induced rats(ASD model), so as to provide evidence for identifying the etiology of ASD. Methods The rats were divided into CON group, VPA group(ASD), acute JZL184 injection group VPA+40 mg/kg JZL184 group(VPA+40AJ)], chronic JZL184 injection group including VPA+1 mg/kg JZL184 group(VPA+1RJ), VPA+3 mg/kg JZL184 group(VPA+3RJ) and VPA+10 mg/kg JZL184 group(VPA+10RJ) ]. The ASD-like behavior of rats in each group was assessed. The levels of endocannabinoids(eCBs) in the hippocampus of rats were detected by liquid chromatography-mass spectrometry. Western blot was used to test the expression levels of related receptors and metabolic enzymes in eCB system. Results The levels of 2-AG and AEA in VPA group were significantly lower than those in CON group(P<0.05). After JZL184 intervention, the levels of 2-AG in VPA+3RJ group and VPA+10RJ group significantly increased(P<0.05). Compared with the CON group, the number of buried marbles, self-grooming time and spontaneous activities increased significantly in VPA group, and the sociability index and the social preference index decreased(P<0.05). After JZL184 intervention, the number of buried marbles, self-grooming time and spontaneous activities decreased, and the sociability index and the social preference index in VPA+40AJ group increased significantly, the self-grooming time of the rats in VPA+1RJ group decreased. After JZL184 intervention, the number of buried marbles, self-grooming time and spontaneous activities decreased, and the social preference index of the rats in VPA+3RJ group increased significantly. The number of buried marbles and self-grooming time decreased, and the social preference index of the rats in VPA+10RJ group increased significantly(P<0.05).The protein expressions of CB1R, DAGL, MAGL and FAAH in VPA group were significantly higher than those in CON group(P<0.05).After JZL184 intervention, the protein expressions of DAGL and MAGL of the rats in VPA+3RJ group were significantly down-regulated, and MAGL in VPA+10RJ group were also significantly down-regulated(P<0.05). Conclusions Low eCBs signal is associated with autistic behaviors in VPA-induced rats, and boosting 2-AG levels can improve repetitive and stereotypical behaviors, hyperactivity and social functions in ASD rats.