基于TLR4/MYD88/NF-κB通路研究降脂通脉饮对高脂血症模型大鼠的影响

The Influence of Granules for Invigorating Circulation and Reducing Blood Lipid on Hyperlipidemia Model Rats Based on TLR4/MYD88/NF-κB Pathway

目的:基于Toll样受体4(Toll-like receptor 4,TLR4)/髓样分化因子88(myeloid differentiation factor 88,MYD88)/核转录因子-κB (nuclear transcription factor-κB,NF-κB)通路探讨降脂通脉饮对高脂血症模型大鼠的影响。方法:从15只SD大鼠中随机选取3只作为空白组,其余大鼠给予高脂饲料2周建立高脂血症模型。将造模成功的大鼠随机分为模型组、降脂通脉饮低剂量组(1.56 mg·kg^(-1))、降脂通脉饮中剂量组(3.125 mg·kg^(-1))、降脂通脉饮高剂量组(6.25 mg·kg^(-1)),每组各3只,给予相应剂量药物8周,每日1次,空白组和模型组给予生理盐水灌胃。全自动生化仪检测大鼠血清血脂水平,包括总胆固醇(total cholesterol,TC)、三酰甘油(triglyceride,TG)、低密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)、高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C);ELISA检测血清炎症因子含量,包括肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)、干扰素-γ(interferon-γ,IFN-γ);Western Blot和qPCR检测颈动脉组织TLR4、MYD88、NF-κB蛋白和基因表达水平。结果:与空白组比较,模型组大鼠血清TC、TG、LDL-C水平升高(P<0.01);与模型组比较,降脂通脉饮低剂量组、中剂量组、高剂量组大鼠血清TC、TG、LDL-C水平降低(P<0.05);各组大鼠血清HDL-C水平比较,差异无统计学意义(P>0.05)。与空白组比较,模型组大鼠血清MCP-1、TNF-α、IFN-γ含量升高(P<0.01);与模型组比较,降脂通脉饮中剂量、高剂量组大鼠血清MCP-1、TNF-α、IFN-γ含量降低(P<0.05),降脂通脉饮低剂量组大鼠血清TNF-α、IFN-γ含量降低(P<0.05)。与空白组比较,模型组大鼠颈动脉组织TLR4 mRNA、MYD88 mRNA、NF-κB mRNA表达水平升高(P<0.01);与模型组比较,降脂通脉饮低剂量、中剂量、高剂量组大鼠颈动脉组织TLR4 mRNA、MYD88 mRNA、NF-κB mRNA表达水平降低(P<0.05)。与空白组比较,模型组大鼠颈动脉组织TLR4、MYD88、NF-κB蛋白表达水平升高(P<0.01);与模型组比较,降脂通脉饮中剂量、高剂量组大鼠颈动脉组织TLR4、MYD88、NF-κB蛋白表达水平降低(P<0.05)。结论:降脂通脉饮可降低高脂血症大鼠血脂水平,其机制可能与抑制TLR4/MYD88/NF-κB通路,从而减轻炎症反应有关。

Objective:To study the influence of Granules for Invigorating Circulation and Reducing Blood Lipid(GICRBL) on hyperlipidemia model rats based on Toll-like receptor 4(TLR4)/myeloid differentiation factor 88(MYD88)/nuclear transcription factor-κB(NF-κB) pathway.Methods:A total of 3 from 15 SD rats were randomly selected as the blank group,and the other rats were given high-fat diet for 2 weeks to establish the hyperlipidemia model.The successfully established model rats were randomly divided into the model group,the low-dose GICRBL group(1.56 mg·kg~(-1)),the medium-dose GICRBL group(3.125 mg·kg~(-1)),and the high-dose GICRBL group(6.25 mg·kg~(-1)),with 3 rats in each group.The rats in the corresponding groups were given the corresponding doses of drugs for 8 weeks,once a day,while the blank group and the model group were given normal saline by gavage.The serum lipid levels of rats were detected by automatic biochemical instrument,including total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),and high-density lipoprotein cholesterol(HDL-C).The serum inflammatory factors were detected by ELISA,including tumor necrosis factor-α(TNF-α),monocyte chemoattractant protein-1(MCP-1),and interferon-γ(IFN-γ).The protein and gene expression levels of TLR4,MYD88,and NF-κB in carotid artery tissue were detected by Western Blot and qPCR.Results:Compared with the blank group,the serum TC,TG and LDL-C levels of the model group were increased(P<0.01).Compared with the model group,the serum TC,TG and LDL-C levels of the low-dose GICRBL group,the medium-dose GICRBL group,and the high-dose GICRBL group were decreased(P<0.05).There was no significant difference in the serum HDL-C level among the groups(P>0.05).Compared with the blank group,the serum MCP-1,TNF-α,and IFN-γ contents of rats in the model group were significantly increased(P<0.01).Compared with the model group,the contents of MCP-1,TNF-α and IFN-γ in the serum of rats in the medium-dose and high-dose GICRBL groups were decreased(P<0.05),and the contents of TNF-α and IFN-γ in the serum of rats in the low-dose GICRBL group were decreased(P<0.05).Compared with the blank group,the expression levels of TLR4 mRNA,MYD88 mRNA,and NF-κB mRNA in the carotid artery tissue of rats in the model group were significantly increased(P<0.01).Compared with the model group,the expression levels of TLR4 mRNA,MYD88 mRNA and NF-κB mRNA in the carotid artery tissue of rats in the low-dose,medium-dose and high-dose groups of Jiangzhitongmaiyin were decreased(P<0.05).Compared with the blank group,the protein expression levels of TLR4,MYD88 and NF-κB in the carotid artery tissue of rats in the model group were significantly increased(P<0.01).Compared with the model group,the protein expression levels of TLR4,MYD88 and NF-κB in the carotid artery tissue of rats in the medium-dose and high-dose groups of GICRBL were significantly decreased(P<0.05).Conclusion:GICRBL can reduce the blood lipid level in hyperlipidemic rats,and its mechanism may be related to inhibiting TLR4/MYD88/NF-κB pathway,thereby reducing inflammatory response.