Objective: To observe the influence of acupuncture on the expression of pivotal molecules of Nod-like receptor protein 3(NLRP3) inflammasome signal pathway in the prefrontal cortex of rats with depression, so as to explore the underlying mechanism of acupuncture on treatment of depression.
Methods: SD rats were randomly divided into 4 groups (8 rats/group)，namely control, model, acupuncture and fluoxetine groups. The depression model was established by using chronic unpredictable mild stress for 6 weeks. During modeling, acupuncture (10 min)was applied to "Baihui"(GV20) and "Yintang"(EX-HN3) for rats of the acupuncture group once a day, with 1 day interval after consecutive 6 day-period for 36 days. Fluoxetine was given (10 mg/kg，1 mg/mL) by gavage to rats of the fluoxetine group every day during modeling for 42 days. The novelty-suppressed feeding test was used to observe feeding behavior of rats. The expressions of NLRP3 and apoptosis associated speck like protein containing a CARD (ASC), Caspase-1, and contents of IL-1β in the prefrontal cortex were detected by Western blot, immunohistoche-mistry and ELISA, separately.
Results: Compared with the control group, the latency of the novelty-suppressed feeding, and the expressions of NLRP3, ASC, Caspase-1 and IL-1β content in the prefrontal cortex of the model group were significantly increased (P<0.01). Following the interventions, the latency of the noveltysuppressed feeding，and the expressions of NLRP3, ASC, Caspase-1 and IL-1β content in the prefrontal cortex in the acupuncture and fluoxetine groups were significantly decreased (P<0.05，P<0.01). There was no significant differences in the above indicators between the acupuncture group and the fluoxetine group (P>0.05).
Conclusion: Acupuncture could inhibit the expression of NLRP3 inflammasome signal pathway in the pre-frontal cortex, and reduce the inflammation in the brain, which may mediate the anti-depressant effect of acupuncture.
目的：观察针刺对抑郁大鼠前额叶皮层NOD样受体蛋白3(NLRP3)炎性小体信号通路上关键分子NLRP3、凋亡相关斑点样蛋白(ASC)、半胱氨酸天冬氨酸蛋白酶-1(Caspase-1)、白细胞介素-1β(IL-1β)表达的影响，探讨针刺抗抑郁的可能机制。方法：将SD大鼠随机分为空白组、模型组、针刺组、氟西汀组，每组8只。采用慢性不可预知温和刺激法制备大鼠抑郁模型。造模期间，针刺组大鼠针刺“百会”“印堂”10 min，1次/d，每针刺6 d休息1 d，共针刺36次；氟西汀组给予氟西汀灌胃(10 mg/kg，浓度为1 mg/mL)，1次/d，共42次。采用新奇抑制实验观察大鼠摄食行为；采用Western blot法检测前额叶皮层NLRP3和ASC表达；免疫组织化学法检测前额叶皮层Caspase-1表达；酶联免疫吸附法检测前额叶皮层IL-1β的含量。结果：与空白组比较，模型组大鼠新奇抑制摄食实验摄食潜伏期显著延长(P<0.01)；与模型组比较，针刺组和氟西汀组大鼠新奇抑制摄食实验摄食潜伏期显著缩短(P<0.05)。与空白组比较，模型组前额叶皮层NLRP3、ASC、Caspase-1的表达和IL-1β含量显著增加(P<0.01)；与模型组比较，针刺组和氟西汀组前额叶皮层NLRP3、ASC、Caspase-1的表达和IL-1β含量显著降低(P<0.01)。针刺组和氟西汀组上述指标的差异无统计学意义(P>0.05)。结论：针刺可缓解大鼠抑郁样行为，其机制可能与抑制前额叶皮层NLRP3炎性小体信号通路相关分子的表达、减轻脑内炎性反应有关。.
Keywords: Acupuncture; Depression; Inflammasome; Nod-like receptor protein 3(NLRP3).