Protective effect of modified Huangqi Chifeng decoction(加味黄芪赤风汤)on immunoglobulin A nephropathy through toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-kappa B signaling pathway

OBJECTIVE:To examine the nephroprotective mechanism of modified Huangqi Chifeng decoction(加味黄芪赤风汤,MHCD)in immunoglobulin A nephropathy(IgAN)rats.METHODS:To establish the IgAN rat model,the bovine serum albumin,lipopolysaccharide,and carbon tetrachloride 4 method was employed.The rats were then randomly assigned to the control,model,telmisartan,and high-,medium-,and low-dose MHCD groups,and were administered the respective treatments via intragastric administration for 8 weeks.The levels of 24-h urinary protein,serum creatinine(CRE),and blood urea nitrogen(BUN)were measured in each group.Pathological alterations were detected.IgA deposition was visualized through the use of immunofluorescence staining.The ultrastructure of the kidney was observed using a transmission electron microscope.The expression levels of interleukin-6(IL-6),monocyte chemoattractant protein-1(MCP-1),and transforming growth factor-β1(TGF-β1)were examined by immunohistochemistry and quantitative polymerase chain reaction.Levels of toll-like receptor 4(TLR4),myeloid differentiation factor 88(MyD88),and nuclear factor-kappa B(NF-κB)P65,were examined by immunohistochemistry,Western blotting,and quantitative polymerase chain reaction.RESULTS:The 24-h urine protein level in each group increased significantly at week 6,and worsen from then on.But this process can be reversed by treatments of telmisartan,and high-,medium-,and low-dose of MHCD,and these treatments did not affect renal function.Telmisartan,and high-,and medium-dose of MHCD reduced IgA deposition.Renal histopathology demonstrated the protective effect of high-,medium-,and low-dose of MHCD against kidney injury.The expression levels of MCP-1,IL-6,and TGF-β1 in kidney tissues were downregulated by low,medium and high doses of MHCD treatment.Additionally,treatment of low,medium and high doses of MHCD decreased the protein and mRNA levels of TLR4,MyD88,and NF-κB.CONCLUSIONS:MHCD exerted nephroprotective effects on IgAN rats,and MHCD regulated the expressions of key targets in TLR4/MyD88/NF-κB signaling pathway,thereby alleviating renal inflammation by inhibiting MCP-1,IL-6 expressions,and ameliorating renal fibrosis by inhibiting TGF-β1 expression.

Electroacupuncture Attenuates Immune-Inflammatory Response in Hippocampus of Rats with Vascular Dementia by Inhibiting TLR4/MyD88 Signaling Pathway

Objective:To investigate whether electroacupuncture(EA)alleviates cognitive impairment by suppressing the toll-like receptor 4(TLR4)/myeloid differentiation factor 88(MyD88)signaling pathway,which triggers immune-inflammatory responses in the hippocampus of rats with vascular dementia(VaD).Methods:The experiments were conducted in 3 parts and in total the Sprague-Dawley rats were randomly divided into 8 groups by a random number table,including sham,four-vessel occlusion(4-VO),4-VO+EA,4-VO+non-EA,sham+EA,4-VO+lipopolysaccharide(LPS),4-VO+LPS+EA,and 4-VO+TAK-242 groups.The VaD model was established by the 4-VO method.Seven days later,rats were treated with EA at 5 acupoints of Baihui(DV 20),Danzhong(RN 17),Geshu(BL 17),Qihai(RN 6)and Sanyinjiao(SP 6),once per day for 3 consecutive weeks.Lymphocyte subsets,lymphocyte transformation rates,and inflammatory cytokines interleukin-6(IL-6)and tumor necrosis factorα(TNF-α)were measured to assess immune function and inflammation in VaD rats.Transmission electron microscopy was used to observe the ultrastructure of nerve cells in the hippocampus.The levels of TLR4,MyD88,IL-6,and TNF-αwere detected after EA treatment.TLR4/MyD88 signaling and cognitive function were also assessed after intracerebroventricular injection of TLR4 antagonist TAK-242 or TLR4 agonist LPS with or without EA.Results:Compared with the 4-VO group,EA notably improved immune function of rats in the 4-VO+EA group,inhibited the protein and mRNA expressions of TLR4 and MyD88 in the hippocampus of rats,reduced the expressions of serum IL-6 and TNF-α(all P<0.05 or P<0.01),and led to neuronal repair in the hippocampus.There were no significant differences between the 4-VO+LPS+EA and 4-VO+EA groups,nor between the 4-VO+TAK-242 and 4-VO+EA groups(P>0.05).Conclusions:EA attenuated cognitive impairment associated with immune inflammation by inhibition of the TLR4/MyD88 signaling pathway.Thus,EA may be a promising alternative therapy for the treatment of VaD.

Therapeutic Effect of Crocin on Diabetic Retinopathy in Rats Based on TLR4/My D88/NF-κB Pathway

Objective:To study the therapeutic effect of crocin on diabetic retinopathy(DR)in rats based on toll-like receptor 4(TLR4)/myeloid differentiation factor 88(My D88)/nuclear factor-κB(NF-κB)pathway.Methods:Thirty SPF SD rats were used in the experiment,which were randomly divided into DR group,control group and crocin group,with 10 rats in each group.The DR rat model was established by feeding the rats in both the DR group and crocin group with a high glucose and high fat diet,along with intraperitoneal injection(IP)of streptozotocin.Crocin IP was administered to the rats in the crocin group,whereas the rats in the DR group and control group received an equivalent dosage of saline IP for 12 weeks.A comparison was made among the three groups regarding retinal thickness,vascular permeability,expression of TLR4/My D88/NF-κB pathway protein,levels of inflammatory factors,and levels of Bcl-2,Bax,and Bcl-2/Bax.Results:The DR group and crocins group exhibited a lower retinal thickness compared to the control group,while the crocins group displayed a higher thickness than the DR group.The DR group and crocins group had higher retinal vascular permeability than the control group,and the crocins group had lower retinal vascular permeability than the DR group(P<0.05).TLR4,My D88,and P-NF-κB relative expressions were higher in the DR and crocin groups than in the control group,whereas TLR4,My D88,and P-NF-κB relative expressions were lower in the crocin group than in the DR group(P<0.05).The DR group and crocin group exhibited elevated levels of inflammatory cytokines compared to the control group,while the crocin group displayed decreased levels in comparison to the DR group(P<0.05).The DR group and crocin group exhibited lower levels of Bcl-2 and Bcl-2/Bax compared to the control group,whereas the control group displayed higher levels of Bax.The crocin group exhibited elevated levels of Bcl-2 and Bcl-2/Bax compared to the DR group,whereas the DR group displayed diminished levels of Bax(P<0.05).Conclusion:Crocin has the potential to enhance the retinal thickness and vascular permeability of DR rats,and the inhibition of the TLR4/My D88/NF-κB pathway by crocin could play a crucial role in impeding the advancement of DR.

四神丸挥发油对慢性溃疡性结肠炎小鼠TLR/MyD88信号通路的调控作用

目的:从Toll样受体(TLR)/髓样分化因子88(MyD88)信号通路,探讨四神丸挥发油有效治疗慢性溃疡性结肠炎的可能机制。方法:将BALB/c小鼠随机分成正常组,模型组,四神丸挥发油组,二神丸挥发油组,五味子散挥发油组和美沙拉嗪组,采用葡聚糖硫酸钠(DSS)建立慢性溃疡性结肠炎小鼠模型,灌胃给药7 d后,通过体质量、结肠质量、结肠质量指数、结肠长度、结肠镜下损伤评分评价其疗效;用酶联免疫吸附测定法(ELISA)检测结肠组织上清液中白细胞介素-4(IL-4),白细胞介素-10(IL-10),白细胞介素-17A(IL-17A),白细胞介素-21(IL-21)和γ干扰素(IFN-γ)水平,同时用蛋白免疫印迹法(Western blot)法检测各组小鼠结肠黏膜中TLR/MyD88信号通路相关蛋白,包括TLR2,MyD88,Ras相关的C3肉毒素底物1(Rac1),白细胞介素-1受体相关激酶4(IRAK4),白细胞介素-1受体相关激酶1(IRAK1),肿瘤坏死因子受体相关因子6(TRAF6),转化生长因子-β活化激酶1结合蛋白1(TAB1),转化生长因子-β活化激酶1结合蛋白2(TAB2),丝裂原活化蛋白激酶激酶6(MKK6),p38丝裂原活化蛋白激酶(p38 MAPK)和环磷腺苷效应元件结合蛋白(CREB)的表达水平。结果:与正常组比较,模型组结肠长度显著降低,结肠质量、结肠质量指数和结肠镜下病理损伤评分均显著升高,IL-10水平显著降低,IL-4,IL-21和IFN-γ水平明显升高(P<0.05,P<0.01),TLR2,MyD88,Rac1,IRAK4,IRAK1,TRAF6,TAB1,TAB2,MKK6,p38 MAPK和CREB蛋白表达量均显著升高(P<0.01);与模型组比较,经四神丸挥发油干预后,小鼠结肠长度显著增加,结肠质量、结肠质量指数和结肠镜下病理损伤评分均显著降低,且小鼠结肠组织中IL-10水平明显升高,而IL-4,IL-17A,IL-21和IFN-γ水平明显降低(P<0.05,P<0.01),同时小鼠结肠组中TLR2,MyD88,Rac1,IRAK4,IRAK1,TRAF6,TAB1,TAB2,MKK6,p38 MAPK和CREB蛋白表达量均明显下调(P<0.05,P<0.01)。结论:四神丸挥发油能有效改善慢性溃疡性结肠炎的炎性损伤,可能是通过抑制TLR/MyD88信号通路实现的。

基于TLR2/MyD88/NF-κB和NALP3信号通路探讨藏族药短穗兔耳草提取物抗慢性酒精性肝损伤大鼠的作用机制

目的:通过酒精灌胃8周建立大鼠慢性酒精性肝损伤模型,研究藏族药短穗兔耳草提取物对Toll样受体(TLR2/髓样分化因子88(MyD88)/核转录因子-κB(NF-κB)和NOD样受体蛋白3(NALP3)信号通路的影响,探讨其提取物抗慢性酒精性肝损伤的作用机制。方法:60只SD雄性大鼠随机分成正常组、模型组、联苯双酯组(0.1 g·kg^-1)及短穗兔耳草低、中、高剂量组(0.5,1,2 g·kg^-1),每日上午各给药组按10 m L·kg^-1给予相应的药物,下午梯度乙醇灌胃法给予56度白酒灌胃,连续8周后,取血,测定各组大鼠血清中天门冬氨酸氨基转移酶(AST),丙氨酸氨基转移酶(ALT),甘油三酯(TC),总胆固醇(TG)及肝脏谷胱甘肽(GSH)水平;酶联免疫吸附测定(ELISA)检测大鼠血清中白细胞介素-1β(IL-1β)水平;蛋白免疫印迹法(Western blot)检测肝脏中TLR2,MyD88,NF-κB和NALP3蛋白的表达;苏木素-伊红(HE)染色观察肝脏病理学形态改变。结果:与正常组比较,模型组血清中AST,ALT,TC,TG,IL-1β水平均明显升高(P<0.05,P<0.01);与模型组比较,藏族药短穗兔耳草各剂量组能降低血清AST,ALT,TC,TG,IL-1β水平,其中高剂量组的效果尤为显著(P<0.05,P<0.01)。与正常组比较,模型组肝匀浆中GSH水平下降;模型组肝组织中TLR2,MyD88,NF-κB和NALP3蛋白水平明显升高(P<0.05,P<0.01);与模型组比较,藏族药短穗兔耳草各剂量组能降低肝脏中GSH水平以及TLR2,MyD88,NF-κB和NALP3的蛋白表达(P<0.05,P<0.01);肝脏病理切片表明,藏族药短穗兔耳草能改善大鼠肝组织病理变化。结论:藏族药短穗兔耳草对酒精诱导的慢性酒精性肝损伤大鼠具有一定的保护作用,其机制可能与TLR/MyD88/NF-κB和NALP3信号通路有关。

Toll样受体4介导的MyD88信号通路在脑缺血损伤中的作用

脑缺血损伤发生机制十分复杂,目前有多种相关学说,大量研究表明炎症反应是脑缺血损伤主要机制之一,然而炎性瀑布反应触发后更加剧了脑损伤的发展,其中炎性受体发挥了重要作用。研究表明Toll样受体4(TLR4)在脑缺血的发生、发展和继发性脑损伤中起重要作用,髓样分化因子88(MyD88)是TLR4信号转导通路中关键的衔接蛋白,能够启动下游炎性因子的转导。对TLR4介导的MyD88信号通路在脑缺血损伤中的作用进展做一综述。