双重特异性磷酸酶15基因对吗啡敏化的调控作用

Dual-specificity phosphatase 15(DUSP15)in the nucleus accumbens is a novel negative regulator of morphine sensitization

目的研究小鼠伏隔核(nucleus accumbens,NAc)中双重特异性磷酸酶15(dual-specificity phosphatase 15,DUSP15)在吗啡敏化中的作用。方法观察吗啡对小鼠自主活动及急性吗啡诱导小鼠活动的增强效应。采用Western blotting检测小鼠NAc中细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK)、p-ERK和DUSP15的表达。利用脑立体定位微量注射技术向小鼠NAc注射DUSP15过表达病毒(AAV-DUSP15),免疫荧光染色明确病毒表达。Western blotting检测AAV-DUSP15对DUSP15、ERK与p-ERK表达的影响;旷场实验评估小鼠自主活动情况。结果小鼠腹腔连续注射10 mg/kg吗啡7 d(连续注射1针/d),停药1周可诱导小鼠敏化行为。与盐水对照组相比,吗啡组小鼠ERK活化水平增高(p-ERK/ERK),DUSP15表达水平降低。与盐水对照组相比,向吗啡小鼠NAc注射AAV-DUSP15,DUSP15表达水平显著增高,ERK活化水平显著降低;小鼠活动距离及总活动距离显著降低。结论小鼠NAc中DUSP15通过负性调控ERK活化水平在吗啡敏化中起到关键调控作用,DUSP15激动剂对毒品成瘾具有潜在的治疗作用。

Objective To study the role of dual-specificity phosphatase 15(DUSP15)in mouse nucleus accumbens(NAc)in morphine sensitization.Methods The distance was recorded by open field test(OFT),and morphine sensitization behavior was observed by acute morphine administration.The protein expressions of extracellular regulated protein kinases(ERK),p-ERK and DUSP15 were tested using Western blotting.DUSP15-overexpressed virus(AAVDUSP15)was injected into mouse NAc by brain stereotactic injection.Immunofluorescence staining confirmed viral expression.Western blotting was used to detect the effect of AAV-DUSP15 on the expressions of DUSP15,ERK and PERK.OFT was used to observe morphine sensitization behavior.Results The sensitization behavior was induced by intraperitoneal injection of 10 mg/kg morphine(continuous injection of 1 dose/day,for 7 doses)and withdrawal of morphine for 1 week.Compared with the saline control group,p-ERK was found to be increased and DUSP15 was found to be decreased.Intra-NAc infusions of AAV-DUSP15(overexpression)not only inhibited the expression of p-ERK but also prevented morphine sensitization behavior.Conclusion DUSP15 negatively regulates ERK activation level in mouse NAc.DUSP15 agonist has a potential therapeutic effect on drug addiction.