姜黄素通过抑制JNK介导的炎症缓解慢性束缚应激诱导的大鼠心脏功能障碍

Curcumin alleviates chronic restraint stress-induced cardiac dysfunction in rats by inhibiting JNK-mediated inflammation

目的:探讨姜黄素对慢性束缚应激抑郁模型大鼠心功能障碍的影响。方法:将32只重(200±20)g的6周龄雄性Wister大鼠分为对照组、模型组、低剂量姜黄素组和高剂量姜黄素组,每组8只。模型组和给药组大鼠每天随机时段给予慢性束缚应激5 h,对照组大鼠正常条件饲养;在每天的应激结束后,低、高剂量姜黄素组大鼠分别给予100和200 mg/kg的姜黄素灌胃,对照组和模型组大鼠则给予等体积的生理盐水。上述实验操作均连续28 d。实验期间每周称量一次体重;在第14和28天进行蔗糖偏好实验和测量血清皮质酮含量来评价大鼠的抑郁状况;HE和Masson染色法观察心肌组织学变化;超声心动图检查各组大鼠心脏功能;RT-qPCR检测炎症因子和纤维化因子的mRNA表达;Western blot检测相关蛋白的表达。结果:与对照组相比,模型组大鼠体重增长显著减缓(P<0.05),蔗糖偏好率显著降低(P<0.01),血浆皮质酮水平显著升高(P<0.01);HE染色结果显示,与对照组相比,模型组大鼠心肌细胞肥大;Masson染色发现,模型组大鼠心脏纤维化显著高于对照组(P<0.01);免疫组化结果也表明,I型胶原阳性表达显著增加(P<0.01);RT-qPCR结果显示,与对照组相比,模型组大鼠心肌组织中炎症因子(肿瘤坏死因子α、白细胞介素6和白细胞介素1β)和纤维化因子(α-平滑肌肌动蛋白、I型胶原和III型胶原)表达水平均显著升高(P<0.05或P<0.01);Western blot结果显示,与对照组相比,模型组大鼠心肌组织中c-Jun氨基末端激酶(JNK)蛋白的磷酸化水平显著升高(P<0.01)。与模型组相比,低、高剂量姜黄素均可逆转上述指标。结论:姜黄素能抑制慢性束缚应激大鼠的心脏炎症和纤维化,其机制可能是通过抑制JNK信号通路实现的。

AIM:To investigate the effects of curcumin on cardiac dysfunction induced by chronic restraint stress in a depression rat model.METHODS:Thirty-two Wistar rats weighing(200±20)g were randomly divided into control,model,low-dose curcumin,and high-dose curcumin groups(n=8 per group).The rats in model and curcumin groups were subjected to chronic restraint stress for 5 h daily at random time,while those in control group were maintained under normal conditions.Following daily stress exposure,the rats in low-and high-dose curcumin groups received 100 and 200 mg/kg curcumin daily,respectively,and those in control and model groups received the same volume of normal saline daily.The above treatments lasted for 28 d.Body weight of the rats was measured weekly.Sucrose preference test was performed on days 14 and 28 of the experiment.Serum corticosterone content was determined to evaluate depression.Histological changes of cardiac tissues were observed using HE and Masson staining.Echocardiography was conducted to examine heart function.The related mRNA and protein levels were detected using RT-qPCR and Western blot,respectively.RESULTS:Compared with control group,the rats in model group exhibited significantly slower weight gain(P<0.05),impaired sucrose preference(P<0.01),and increased corticosterone levels(P<0.01).HE staining revealed myocardial hypertrophy in model group but not in control group.Masson staining indicated significantly higher cardiac fibrosis in model group than control group(P<0.01).Immunohistochemical staining demonstrated a significant increase in positive collagen type I expression(P<0.01).RT-qPCR results showed significantly elevated mRNA levels of inflammatory cytokines(tumor necrosis factor-α,interleukin-6,and interleukin-1β)and fibrosis factors(α-smooth muscle actin,collagen type I,and collagen type III)in model group compared with control group(P<0.05 or P<0.01).Western blot revealed a significant increase in c-Jun N-terminal kinase(JNK)phosphorylation level in model group(P<0.01).Treatment with low-and high-dose curcumin reversed the above indicators.CONCLUSION:Curcumin treatment attenuated cardiac inflammation and fibrosis in rats subjected to chronic restraint stress,possibly by inhibiting JNK signaling pathway.