海马ICAM5对小鼠饮酒行为的影响及机制研究

Effect and mechanism of ICAM5 on alcohol dependence behavior of mice

目的 分析小鼠海马组织中ICAM5对小鼠饮酒偏好、运动能力等行为的影响,并分析其可能的作用机制。方法 选取8周龄C57BL/6J雄性小鼠,随机将小鼠分为饮水组和饮酒组,建立双瓶饮酒模型。检测ICAM5在小鼠内侧前额叶皮层、海马及杏仁核脑区的表达改变。构建ICAM5过表达腺相关病毒,通过脑立体定位方法注射至海马脑区。通过免疫荧光技术和Western blot检测海马组织ICAM5的蛋白表达水平。通过旷场实验、条件位置偏爱实验和翻正反射实验,观察小鼠对酒精的偏好性以及ICAM5对小鼠行为的影响。通过Western blot检测分析树突棘F-actin/G-actin比值,高尔基染色方法检测树突棘形态。结果 在双瓶饮酒模型中,与饮水组相比,饮酒组小鼠海马脑区ICAM5的表达显著下降(P<0.001)。结果显示,通过荧光显微镜观察到ICAM5在小鼠海马脑区特异性表达。在旷场实验中,AAV-ICAM5组小鼠较对照组小鼠在旷场中心位置停留时间(P<0.01)和运动距离明显增加(P<0.001)。在CPP实验中,测试期AAV-ICAM5小鼠在伴药箱的停留时间较对照组小鼠明显降低(P<0.001)。在LORR实验中,过表达ICAM5可以明显降低小鼠镇静潜伏期(P<0.01),但同时显著缩短镇静作用的持续时间(P<0.001)。与AAV-mCherry+Water组相比,饮酒后小鼠海马F-actin/G-actin比值显著升高(P<0.01),而ICAM5过表达后这一比值显著降低(P<0.001)。与AAV-mCherry+Water组相比,饮酒后小鼠海马CA1区树突棘密度增加(P<0.001),但是AAV-ICAM5+Alcohol组树突棘密度显著降低(P<0.01)。结论 海马ICAM5可能通过调节细胞骨架蛋白的表达,形成树突棘结构可塑性改变,最终引起小鼠饮酒和运动行为的改变。

ObjectiveWe investigated the effects of ICAM5 in the hippocampus on the alcohol drinking preference of mice,and the potential mechanisms.Methods An alcohol two-bottle choice model was developed in 8-week-old male C57BL/6J mice,which were randomly divided to two groups:water group and alcohol group.The protein expression of ICAM5 in the hippocampus,amygdala,and medial prefrontal cortex was detected.An ICAM5-overexpressing adeno-associated virus was constructed and injected into the hippocampus by stereotaxic method.The expression level of ICAM5 protein in the hippocampus was detected by immunofluorescence and Western blot.We then detected the alcohol preference and locomotor activity of mice with a conditioned place preference(CPP)experiment,open field test,and loss-of-righting reflex test.Western blot analysis was used to identify the neuron F-actin/G-actin ratio.Using Golgi staining,the morphology of dendritic spines was identified.Results The expression of ICAM5 in the hippocampus of alcohol two-bottle choice model mice in the alcohol group was considerably lower than that of the water group(P<0.001).The specific expression of ICAM5 in the hippocampus of mice was observed by fluorescence microscopy.In the open field experiment,the staying time and moving distance of the AAV-ICAM5 group were significantly increased compared with those of the control group(P<0.01).In the CPP experiment,the residence time of AAV-ICAM5 mice in the alcohol-paired compartment was significantly lower than that of control mice(P<0.001).In the loss-of-righting reflex experiment,overexpression of ICAM5 significantly reduced sedation latency(P<0.01),but significantly shortened the duration of sedation(P<0.001).Compared with AAV-mCherry+Water group,the ratio of F-actin/G-actin in the hippocampus was significantly increased after drinking(P<0.01),but after ICAM5 overexpression,their F-actin/G-actin ratio was significantly decreased(P<0.001).Compared with AAV-mCherry+Water group,the density of dendritic spines in the hippocampal CA1 region was increased(P<0.001),but the density of dendritic spines in the AAV-ICAM5+Alcohol group was significantly decreased(P<0.01).Conclusions ICAM5 modulated the expression of cytoskeleton proteins to change the structural plasticity of dendritic spines,which contributed to alcohol-drinking and locomotor behavioral changes in mice.