Ghrelin基因敲除对小鼠黑质区多巴胺能神经元突触后电位的影响  

Effect of ghrelin gene knockout on the postsynaptic potential of dopaminergic neurons in the substantia nigra of mice

作　　者：刘静[1] 李焕焕[1] 焦倩[1] 陈曦[1] 姜宏[1] 杜希恂[1] LIU Jing;LI Huanhuan;JIAO Qian;CHEN Xi;JIANG Hong;DU Xixun(State Key(Cultivation)Disciplines of Physiology,Qingdao University,Qingdao 266071,China)

机构地区：[1]青岛大学国家生理学重点(培育)学科,山东青岛266071

出　　处：《精准医学杂志》2024年第3期199-202,208,共5页Journal of Precision Medicine

基　　金：国家自然科学基金面上项目(32371181)。

摘　　要：目的探讨胃饥饿素(ghrelin)基因敲除对小鼠黑质多巴胺能神经元突触后电位的影响。方法分别选取10周龄雄性ghrelin基因敲除小鼠(ghrelin^(-/-)组)及其同窝雄性野生型(WT)小鼠(WT组)的黑质组织,采用转录组学测序(RNA-seq)技术筛选差异表达基因(DEGs),通过KEGG通路富集分析DEGs可能参与的神经元突触活动相关信号通路,采用实时荧光定量PCR(RT-qPCR)方法对筛选出的DEGs进行验证,并应用蛋白免疫印迹(Western blotting)方法检测神经元突触活动相关基因的蛋白表达情况。结果与WT组相比,ghrelin^(-/-)组小鼠多巴胺能神经元突触传递信号通路上的23个基因水平发生了显著性变化,其中谷氨酸促离子型受体α-氨基-3-羟基-5-甲基-4-异唑丙酸型亚基3(GluA3)和糖原合酶激酶-3β(GSK-3β)分别调控神经元突触后膜上的α-氨基-3-羟基-5-甲基-4-异唑丙酸受体和N-甲基-D-天冬氨酸受体;在ghrelin^(-/-)组小鼠黑质组织中,GluA 3和GSK-3β基因表达出现明显的下调。RT-qPCR方法检测结果显示,与WT组相比,ghrelin^(-/-)组小鼠黑质组织当中GluA 3和GSK-3βmRNA水平明显下调(t=2.408、2.740,P<0.05)。Western blotting方法检测结果显示,与WT组相比,ghrelin^(-/-)组小鼠黑质组织中GluA3蛋白的表达水平明显上调(t=2.530,P<0.05),GSK-3β蛋白的表达明显下调(t=3.469,P<0.05)。结论Ghrelin基因敲除可能通过使小鼠黑质多巴胺能神经元突触后电位长时程增强,从而增强兴奋性突触传递活动,参与运动调控。Objective To study the effect of ghrelin gene knockout on the postsynaptic potential of dopaminergic neurons in the substantia nigra of mice.Methods Substantia nigra tissue was taken from 10-week-old ghrelin^(-/-)male mice(ghrelin^(-/-)group)and their male wild-type(WT)littermates(WT group).RNA-seq technique was used to screen differently expressed genes(DEGs).KEGG pathway enrichment analysis was performed for the neuronal synaptic activity-associated signaling pathways which DEGs might be involved in.Quantitative real-time PCR(RT-qPCR)was used for validation of the identified DEGs,and western blotting was used for protein expression of neuronal synaptic activity-related genes.Results Compared with the WT group,the ghrelin^(-/-)group had significant changes in the expression levels of 23 genes in the synaptic signaling pathway of dopaminergic neurons.Specifically,Ionotropic glutamate receptorsα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid type subunit 3(GluA3)and glycogen synthase kinase3-β(GSK-3β)regulatedα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor and N-methyl-D-aspartic acid receptor on the postsynaptic membrane of neurons,respectively.GluA3 and GSK-3βgenes were significantly downregulated in the substantia nigra tissue of mice in the ghrelin^(-/-)group.RT-qPCR results showed that compared to the WT group,the ghrelin^(-/-)group had significant downregulation of the mRNA expression levels of GluA3 and GSK-3βin the substantia nigra tissue of mice(t=2.408,2.740,P<0.05).Western blotting results showed that compared with the WT group,the ghrelin^(-/-)group had a significantly upregulated expression level of GluA3 protein(t=2.530,P<0.05)and a significantly downregulated expression level of GSK-3βprotein(t=3.469,P<0.05)in the substantia nigra tissue of mice.Conclusion Ghrelin gene knockout may enhance the excitatory synaptic transmission activity by enhancing the postsynaptic potential of substantia nigra dopaminergic neurons in mice for a long time,thus regulating movement.

关 键 词：胃促生长素 基因敲除技术 黑质 多巴胺能神经元 长时程增强 受体 离子型谷氨酸 

分 类 号：R338.1[医药卫生—人体生理学] R394[医药卫生—基础医学]