RNA腺苷脱氨酶对社会隔离小鼠攻击行为的缓解作用及5-羟色胺-2C受体机制

The role of adenosine deaminase acting on RNA in the remission of aggression behavior in socially isolated mice and the mechanism of 5-serotonin-2C receptor

目的探讨RNA腺苷脱氨酶1(adenosine deaminase acting on RNA 1,ADAR1)作用于5-羟色胺-2C受体对社会隔离小鼠攻击行为的缓解作用。方法60只21日龄的健康雄性BALB/c小鼠按照随机数字表法分为6组:社会隔离组、群居对照组、ADAR1诱导剂隔离组、ADAR1抑制剂隔离组、ADAR1诱导剂群居组和ADAR1抑制剂群居组,采用单笼饲养4周方法建立社会隔离模型,采用群居饲养方法作为对照组。ADAR1诱导剂隔离组和ADAR1抑制剂隔离组分别给予ADAR1诱导剂(5.0×10^4U/kg)和抑制剂(10 mg/kg)进行腹腔注射。采用入侵者实验评价小鼠的攻击性行为,免疫组化和蛋白免疫印迹实验检测小鼠脑内ADAR1和5-羟色胺-2C受体的表达变化。结果社会隔离组小鼠的攻击潜伏期明显低于群居对照组[(43.15±6.99)s,(542.40±30.50)s;t=15.906,P<0.01],ADAR1诱导剂隔离组小鼠的攻击潜伏期[(256.70±29.49)s]明显高于社会隔离组(t=7.046,P<0.01),ADAR1抑制剂隔离组小鼠的攻击潜伏期[(15.25±2.18)s]明显低于社会隔离组(t=3.809,P<0.01)。社会隔离组小鼠杏仁核各区ADAR1免疫反应阳性表达细胞的光密度值显著低于群居对照组相应脑区[BLA区:(0.038±0.002),(0.074±0.004);LaDL区:(0.033±0.002),(0.060±0.002);LaVM区:(0.045±0.003),(0.073±0.004);LaVL区:(0.044±0.003),(0.070±0.003);t=8.428,9.037,6.462,5.698,均P<0.01];ADAR1诱导剂隔离组小鼠的杏仁核区ADAR1免疫反应阳性表达细胞的光密度值[BLA区:(0.060±0.003),LaDL区:(0.042±0.002),LaVM区:(0.056±0.004),LaVL区:(0.054±0.003)]明显高于社会隔离小鼠对应脑区,分别为(t=6.055,2.876,2.312,2.492;均P<0.05]。社会隔离组小鼠杏仁核区ADAR1蛋白和5-羟色胺-2C受体蛋白的表达均明显低于群居对照组(t=11.37,12.65;均P<0.01)。ADAR1诱导剂隔离小鼠杏仁核区ADAR1蛋白和5-羟色胺-2C受体蛋白表达均明显高于社会隔离组(t=3.02,4.401;均P<0.05)。结论ADAR1诱导剂可通过增强社会隔离BALB/c小鼠杏仁核5-羟色胺-2C受体的蛋白表达缓解社会隔离BALB/c小鼠的攻击性行为。

Objective To investigate the effect of adenosine deaminase acting on RNA 1(ADAR1)on 5-serotonin-2c receptor in alleviating aggression in socially isolated mice.Methods Sixty healthy male BALB/c mice aged 21 days were randomly divided into six groups:social isolation group,social control group,ADAR1 inducer social isolation group,ADAR1 inhibitor social isolation group,ADAR1 inducer social control group and ADAR1 inhibitor control group.The mice fed in single cage for 4 weeks were used as social isolation model while the mice fed in group were used as control group.ADAR1 inducer(5.0×10^4 U/kg)and inhibitor(10 mg/kg)were given intraperitoneally to mice in the ADAR1 inducer social isolation group and the ADAR1 inhibitor social isolation group respectively.The aggressive behavior of mice was evaluated by resident-intruder test.The expression of ADAR1 and 5-serotonin-2c receptors in the brain of mice was detected by immunohistochemistry and Western blot.Results The attack latency of social isolation group was significantly lower than that of social control group((43.15±6.99)s,(542.40±30.50)s;t=15.906,P<0.01),and the latency of attack((256.70±29.49)s)in the ADAR1 inducer social isolation group was significantly higher than that in the social isolation group(t=7.046,P<0.01).The latency of attack((15.25±2.18)s)in the ADAR1 inhibitor social isolation group was significantly lower than that in the social isolation group(t=3.809,P<0.01).The optical density of ADAR1 immunoreactive cells in the amygdala of the social isolation group mice was significantly lower than that in the corresponding brain area of the social control group(BLA:(0.038±0.002),(0.074±0.004);LaDL:(0.033±0.002),(0.060±0.002);LaVM:(0.045±0.003),(0.073±0.004);Lavl area:(0.044±0.003),(0.070±0.003);t=8.428,9.037,6.462,5.698,all P<0.01).The optical density of ADAR1 immunoreactive positive cells in the amygdala(BLA:(0.060±0.003),LaDL:(0.042±0.002),LaVM:(0.056±0.004),Lavl:(0.054±0.003)in the ADAR1 inducer social isolation group was significantly higher than those in the corresponding brain area of the social isolation group mice(t=6.055,2.876,2.312,2.492;all P<0.05).The expression of ADAR1 protein and 5-serotonin-2c receptor protein in amygdala of social isolation group were significantly lower than those of social isolation group(t=11.37,12.65;P<0.01).The expression of ADAR1 protein and 5-serotonin-2c receptor protein in the amygdala of the ADAR1 inducer social isolation group were significantly higher than those of the social isolation group(t=3.02,4.401;P<0.05).Conclusion ADAR1 inducer alleviates the aggressive behavior of social isolated BALB/c mice by enhancing the protein expression of 5-serotonin-2c receptor in the amygdala of social isolated BALB/c mice.