基于TLR4/MyD88/NF-κB信号通路探讨大蒜素对大鼠冠状动脉微栓塞的影响及作用机制

Effect and mechanism of diallyl trisulfide on coronary microembolization in rats based on TLR4/MyD88/NF-κB signaling pathway

目的基于TLR4/MyD88/NF-κB信号通路探讨大蒜素对大鼠冠状动脉微栓塞(CME)的影响及作用机制。方法将60只SD大鼠随机分为空白对照组、模型组、阳性对照组、大蒜素低、中、高剂量组,每组10只,其中空白对照组和模型组给予等体积生理盐水灌胃,阳性对照组给予瑞舒伐他汀3.0mg/(kg·d)灌胃,大蒜素低、中、高剂量组分别给予大蒜素10、20、40mg/(kg·d)灌胃,预处理14天后,模型组、阳性对照组及大蒜素低、中、高剂量组采用左心室注射42μm微栓塞球造模,空白对照组采用左心室注射等体积生理盐水。检测大鼠心功能变化;HBFP染色法检测心肌微梗死面积;TUNEL法检测心肌细胞凋亡情况;ELISA法检测白细胞介素1β(IL-1β)和肿瘤坏死因子α(TNF-α)含量;电化学法检测肌钙蛋白I(cTnI)和肌酸激酶同工酶(CK-MB)水平;RT-PCR法检测大鼠心肌组织中Toll样受体4(TLR4)、髓样分化因子88(MyD88)和核因子κBp65(NF-κBp65)mRNA水平;Western blot法检测大鼠心肌组织中TLR4、MyD88和NF-κBp65蛋白表达。结果大蒜素可显著改善CME大鼠心功能,明显降低心肌微梗死面积和心肌细胞凋亡率,有效抑制炎症因子IL-1β、TNF-α和心肌损伤指标cTnI、CK-MB表达,明显下调TLR4、MyD88和NF-κBp65 mRNA和蛋白相对表达量。结论大蒜素可抑制CME大鼠心脏功能障碍和心肌损伤,其作用机制可能与TLR4/MyD88/NF-κB信号通路密切相关。

Aim To discuss the effect and mechanism of diallyl trisulfide on coronary microembolization ( CME) in rats based on the TLR4 /MyD88 /NF-κB signaling pathway. Methods Sixty SD rats were randomly divided into blank control group,model group,positive control group,low,medium and high dose groups of diallyl trisulfide,10 rats in each group. The blank control group and model group were given the same volume of normal saline,the positive control group was given rosuvastatin ( 3.0 mg /( kg·d) ) ,and the diallyl trisulfide low,medium and high dose groups were given diallyl trisulfide ( 10,20,40 mg /( kg·d) ) . After 14 days of pretreatment,CME models were established in the model group,the positive control group,the diallyl trisulfide low,middle and high dose groups by injecting 42 μm microembolic balls into the left ventricle,and the blank control group was injected the same volume of normal saline into the left ventricle. The changes of cardiac function were detected,the area of myocardial microinfarction was detected by HBFP staining,the apoptosis of myocardial cells was detected by TUNEL,the content of interleukin-1β ( IL-1β) and tumor necrosis factor-α ( TNF-α) were detected by ELISA,electrochemical method was used to detect troponin I ( cTnI) and creatine kinase isoenzyme ( CK-MB) ,the mRNA expressions of Toll-like receptor 4 ( TLR4) ,myeloid differentiation factor 88 ( MyD88) and nuclear factor κB p65 ( NF-κB p65) were detected by RT-PCR,Western blot was used to detect the protein expression of TLR4,MyD88 and NF-κB p65 in rat myocardium. Results Diallyl trisulfide can significantly improve the cardiac function of CME rats,significantly reduce the area of myocardial microinfarction and the apoptotic rate of myocardial cells,effectively inhibit the expression of inflammatory factors IL-1β,TNF-α and myocardial injury indicators cTnI,CK-MB,and significantly reduce the relative expression of TLR4,MyD88 and NF-κB p65 mRNA and protein. Conclusion Diallyl trisulfide can inhibit cardiac dysfunction and myocardial injury in CME rats,and its mechanism may be closely related to TLR4 /MyD88 /NF-κB signaling pathway.