腺苷受体及其介导的 cAMP-PKA 信号通路在对乙酰氨基酚致药物性肝损伤中的作用

目的：探讨腺苷受体及其介导的环磷酸腺苷-蛋白激酶 A (cAMP-PKA)信号通路在对乙酰氨基酚致药物性肝损伤中的作用。方法将20只雄性昆明种小鼠随机分为空白对照组和模型组。模型组给予对乙酰氨基酚500 mg/ kg,空白对照组给予等量的生理盐水,两组均为单次灌胃给药。24 h 后处死小鼠,检测谷丙转氨酶( ALT)、谷草转氨酶(AST)、碱性磷酸酶(ALP)、总胆汁酸(TBA),HE 染色观察肝脏病理变化；原位肝灌注法分离小鼠肝细胞；Real-Time qPCR 法、 Western blot 法分别检测肝细胞腺苷 A1受体(A1R)、A2A 受体( A2AR)、A2B 受体( A2BR)和 A3受体(A3R)水平；ELISA 法检测各组细胞 cAMP 含量；Western blot 法检测各组细胞 PKA、磷酸化-环磷酸腺苷反应元件结合蛋白(p-CREB)的表达水平。结果与空白对照组比较,模型组 AST、ALT、ALP、TBA 表达明显增加(P <0．01)且肝组织损伤明显；与空白对照组比较,模型组腺苷 A1R、A2AR的表达明显升高(P <0．01),cAMP 含量、PKA、p-CREB 蛋白的表达水平也相应增加(P <0．05)。结论对乙酰氨基酚致药物性肝脏损伤可能与 cAMP-PKA 信号通路有关。

Effect of adenosine receptors and cAMP-PKA signaling pathway mediated by adenosine receptors in the model of paracetamol-induced hepatotoxicity

Objective To explore the effect of adenosine receptors and cyclic adenosine monophosphate-protein ki-nase A (cAMP-PKA) signaling pathway mediated by adenosine receptors in the model of paracetamol-induced hep-atotoxicity. Methods Thirty male Kunming mice were randomly divided into normal control group and model group. Model group was treated with paracetamol 500 mg / kg and control group was treated with the same of con-centration normal saline by intragastric administration, respectively. The mice were killed after 24 hours. Serum AST, ALT, ALP, TBA were measured. The histological analysis was performed by HE staining. Hepatocytes were extracted and purified from mice in the liver, followed by the method of in situ perfusion. The expression levels of adenosine A1 receptor (A1R), adenosine A2A receptor (A2AR), adenosine A2B receptor (A2BR) and adeno-sine A3 receptor (A3R) were detected using qRT-PCR and Western blot. The expression levels of cAMP, PKA and phosphorylation-cAMP response element bonding protein (p-CREB) were detected using ELISA and Western blot, respectively. Results The expression levels of AST, ALT, ALP, TBA in model group were much higher than the normal control group (P < 0. 01). The mRNA and protein levels of A1R and A2AR expressed in the mod-el group were obviously higher than the normal control group (P < 0. 01), and the cAMP level in the model group was more than in the normal control group (P < 0. 01). The protein levels of PKA and p-CREB expressed in the model group were higher than the normal control group. Conclusion Paracetamol-induced hepatotoxicity may be involved with the cAMP-PKA signaling pathway.