Objective To investigate the effect of cannabinoid receptor-2 (CB2) agonist AM1241 on nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and interleukin-1β (IL-1β) in liver tissue of mice with acute liver injury induced by concanavalin A (Con-A).
Methods Forty 8-week-old C57BL/6J male mice were randomly divided into a control, a model, and two CB2 receptor agonist (AM1241) groups injected with AM1241 intraperitoneally at doses of 3 and 12 mg/kg one hour before the establishment of acute liver injury model with caudal vein injection of 20 mg/kg Con A in all the mice except for the control mice only with intraperitoneal injection of solvent. Eight hours after the injection of Con A, following indicators were detected for all the mice: serum alanine aminotransferase (ALT); inflammatory body 3 related nucleotide oligomerization domain-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and caspase-1 in liver tissues with Western blot; and expression level of interleukin-1 beta (IL-1β) in liver homogenate with enzyme-linked immunosorbent assay (ELISA).
Results Compared to those in the control mice, significantly increased serum ALT (6 132.5 ± 1 300.8 vs. 28.5 ± 7.4 U/L, P < 0.05), NLRP3, ASC, and caspase-1 in liver tissues ( P < 0.05 for all) were detected in the model mice. In the mice administered with AMl241, significantly decreased serum ALT (2 696.5 ± 956.3 and 534.6 ± 128.6 U/L, both P < 0.05), NLRP3, ASC and caspase-1 protein in liver tissues (all P < 0.05) were detected in comparison with those in the model mice. Significantly decreased IL-1β in liver homogenate was also detected in the mice with AMl241 treatment compared to that in the control mice ( P < 0.05).
Conclusion CB2 receptor agonist AMl241 may have protective effects on Con A-induced acute liver injury in mice and the effects may be related to inhibitions of NLRP3, ASC, caspase-1, and IL-1β expression in liver tissue of mice.
【摘 要】 目的 探讨大麻素 CB2 受体激动剂 AM1241 对刀豆蛋白 A（Con A）所致急性小鼠肝损伤影响及机制。 方法 随机将 40 只 8 周龄 C57BL/6J 雄性小鼠分为对照组、模型组、激动剂（AM1241）3、12 mg/kg 组（于造模前 1 h 分别腹腔注射 AM1241 3、12 mg/kg），除对照组外，其余组小鼠尾静脉注射 Con A 20 mg/kg 复制小鼠急性肝损伤模型，对照组采用相同溶剂和方法。造模 8 h 后留取血清检测丙氨酸转氨酶（ALT），Western blot 法分别检测炎性体 3 相关核苷酸结合寡聚化结构域样受体（NLRs）、凋亡相关斑点样蛋白（ASC）、半胱氨酸天冬氨酸蛋白酶 – 1（caspase-1）蛋白的表达量，利用试剂盒检测肝组织匀浆中白细胞介素 1β（IL-1β）水平。 结果 与对照组[（28.5 ± 7.4）U/L]比较，模型组小鼠血清 ALT 水平[（6 132.5 ± 1 300.8）U/L]明显升高（ P < 0.05），肝组织中 NLRP3、ASC、caspase-1 蛋白表达均明显增强（ P < 0.05）；与模型组比较，AMl241 3、12 mg/kg 组小鼠血清 ALT 水平[分别为（2 696.5 ± 956.3）、（534.6 ± 128.6）U/L] 明显降低（ P < 0.05），肝组织中 NLRP3、ASC、caspase-1 蛋白表达均有所降低（ P < 0.05）；与对照组比较，AMl241 组小鼠肝组织中 IL-1β 含量也明显降低（ P < 0.05）。 结论 CB2 受体激动剂 AMl241 对 Con A 所致急性小鼠肝损伤有一定的拮抗作用，其机制可能与 AM1241 抑制小鼠肝组织中 NLRP3、ASC、caspase-1 蛋白表达，减少肝组织中炎性因子 IL-1β 含量有关。