BACKGROUND Diabetic kidney disease(DKD)is a major complication of diabetes mellitus.Renal tubular epithelial cell(TEC)damage,which is strongly associated with the inflammatory response and mesenchymal trans-differenti...BACKGROUND Diabetic kidney disease(DKD)is a major complication of diabetes mellitus.Renal tubular epithelial cell(TEC)damage,which is strongly associated with the inflammatory response and mesenchymal trans-differentiation,plays a significant role in DKD;However,the precise molecular mechanism is unknown.The recently identified microRNA-630(miR-630)has been hypothesized to be closely associated with cell migration,apoptosis,and autophagy.However,the association between miR-630 and DKD and the underlying mechanism remain unknown.AIM To investigate how miR-630 affects TEC injury and the inflammatory response in DKD rats.METHODS Streptozotocin was administered to six-week-old male rats to create a hypergly cemic diabetic model.In the second week of modeling,the rats were divided into control,DKD,negative control of lentivirus,and miR-630 overexpression groups.After 8 wk,urine and blood samples were collected for the kidney injury assays,and renal tissues were removed for further molecular assays.The target gene for miR-630 was predicted using bioinformatics,and the association between miR-630 and toll-like receptor 4(TLR4)was confirmed using in vitro investigations and double luciferase reporter gene assays.Overexpression of miR-630 in DKD rats led to changes in body weight,renal weight index,basic blood parameters and histopathological changes.RESULTS The expression level of miR-630 was reduced in the kidney tissue of rats with DKD(P<0.05).The miR-630 and TLR4 expressions in rat renal TECs(NRK-52E)were measured using quantitative reverse transcription polymerase chain reaction.The mRNA expression level of miR-630 was significantly lower in the high-glucose(HG)and HG+mimic negative control(NC)groups than in the normal glucose(NG)group(P<0.05).In contrast,the mRNA expression level of TLR4 was significantly higher in these groups(P<0.05).However,miR-630 mRNA expression increased and TLR4 mRNA expression significantly decreased in the HG+miR-630 mimic group than in the HG+mimic NC group(P<0.05).Furthermore,the levels of tumor necrosis factor-alpha(TNF-α),interleukin-1β(IL-1β),and IL-6 were significantly higher in the HG and HG+mimic NC groups than in NG group(P<0.05).However,the levels of these cytokines were significantly lower in the HG+miR-630 mimic group than in the HG+mimic NC group(P<0.05).Notably,changes in protein expression were observed.The HG and HG+mimic NC groups showed a significant decrease in E-cadherin protein expression,whereas TLR4,α-smooth muscle actin(SMA),and collagen IV protein expression increased(P<0.05).Conversely,the HG+miR-630 mimic group exhibited a significant increase in E-cadherin protein expression and a notable decrease in TLR4,α-SMA,and collagen IV protein expression than in the HG+mimic NC group(P<0.05).The miR-630 targets TLR4 gene expression.In vivo experiments demonstrated that DKD rats treated with miR-630 agomir exhibited significantly higher miR-630 mRNA expression than DKD rats injected with agomir NC.Additionally,rats treated with miR-630 agomir showed significant reductions in urinary albumin,blood glucose,TLR4,and proinflammatory markers(TNF-α,IL-1β,and IL-6)expression levels(P<0.05).Moreover,these rats exhibited fewer kidney lesions and reduced infiltration of inflammatory cells.CONCLUSION MiR-630 may inhibit the inflammatory reaction of DKD by targeting TLR4,and has a protective effect on DKD.展开更多
BACKGROUND Fecal microbiota transplantation(FMT)has shown promising therapeutic effects on mice with experimental colitis and patients with ulcerative colitis(UC).FMT modulates the Toll-like receptor 4(TLR4)signaling ...BACKGROUND Fecal microbiota transplantation(FMT)has shown promising therapeutic effects on mice with experimental colitis and patients with ulcerative colitis(UC).FMT modulates the Toll-like receptor 4(TLR4)signaling pathway to treat some other diseases.However,it remains unknown whether this modulation is also involved in the treatment of UC.AIM To clarify the necessity of TLR4 signaling pathway in FMT on dextran sodium sulphate(DSS)-induced mice and explain the mechanism of FMT on UC,through association analysis of gut microbiota with colon transcriptome in mice.METHODS A mouse colitis model was constructed with wild-type(WT)and TLR4-knockout(KO)mice.Fecal microbiota was transplanted by gavage.Colon inflammation severity was measured by disease activity index(DAI)scoring and hematoxylin and eosin staining.Gut microbiota structure was analyzed through 16S ribosomal RNA sequencing.Gene expression in the mouse colon was obtained by transcriptome sequencing.RESULTS The KO(DSS+Water)and KO(DSS+FMT)groups displayed indistinguishable body weight loss,colon length,DAI score,and histology score,which showed that FMT could not inhibit the disease in KO mice.In mice treated with FMT,the relative abundance of Akkermansia decreased,and Lactobacillus became dominant.In particular,compared with those in WT mice,the scores of DAI and colon histology were clearly decreased in the KO-DSS group.Microbiota structure showed a significant difference between KO and WT mice.Akkermansia were the dominant genus in healthy KO mice.The ineffectiveness of FMT in KO mice was related to the decreased abundance of Akkermansia.Gene Ontology enrichment analysis showed that differentially expressed genes between each group were mainly involved in cytoplasmic translation and cellular response to DNA damage stimulus.The top nine genes correlating with Akkermansia included Aqp4,Clca4a,Dpm3,Fau,Mcrip1,Meis3,Nupr1 L,Pank3,and Rps13(|R|>0.9,P<0.01).CONCLUSION FMT may ameliorate DSS-induced colitis by regulating the TLR4 signaling pathway.TLR4 modulates the composition of gut microbiota and the expression of related genes to ameliorate colitis and maintain the stability of the intestinal environment.Akkermansia bear great therapeutic potential for colitis.展开更多
Neuroinflammation is a well-recognized consequence of subarachnoid hemorrhage(SAH), and Toll-like receptor(TLR) 4 may be an important therapeutic target for post-SAH neuroinflammation. Of the TLR family members, TLR4 ...Neuroinflammation is a well-recognized consequence of subarachnoid hemorrhage(SAH), and Toll-like receptor(TLR) 4 may be an important therapeutic target for post-SAH neuroinflammation. Of the TLR family members, TLR4 is expressed in various cell types in the central nervous system, and is unique in that it can signal through both the myeloid differentiation primary-response protein 88-dependent and the toll receptor associated activator of interferon-dependent cascades to coordinate the maximal inflammatory response. TLR4 can be activated by many endogenous ligands having damage-associated molecular patterns including heme and fibrinogen at the rupture of an intracranial aneurysm, and the resultant inflammatory reaction and thereby tissue damages may furthermore activate TLR4. It is widely accepted that the excreted products of TLR4 signaling alter neuronal functions. Previous studies have focused on the pathway through nuclear factor(NF)-κΒ signaling among TLR4 signaling pathways as to the development of early brain injury(EBI) such as neuronal apoptosis and blood-brain barrier disruption, and cerebral vasospasm. However, many findings suggest that both pathways via NF-κΒ and mitogen-activated protein kinases may be involved in EBI and cerebral vasospasm development. To overcome EBI and cerebral vasospasm is important to improve outcomes after SAH, because both EBI and vasopasm are responsible for delayed brain injuries or delayed cerebral ischemia, the most important preventable cause of poor outcomes after SAH. Increasing evidence has shown that TLR4 signaling plays an important role in SAH-induced brain injuries. Better understanding of the roles of TLR4 signaling in SAH will facilitate development of new treatments.展开更多
AIM:To test whether ethanol feeding could induce Toll-like receptor 4(TLR4)responses,assess the hepatoprotective effect of betaine and its inhibitive effect on TLR4 in animal models of alcoholic liver injury.METHODS:F...AIM:To test whether ethanol feeding could induce Toll-like receptor 4(TLR4)responses,assess the hepatoprotective effect of betaine and its inhibitive effect on TLR4 in animal models of alcoholic liver injury.METHODS:Forty-eight female Sprague-Dawley rats were randomly divided into four groups as control,model,low and high dose betaine groups.Except control group,all rats were fed with high fat-containing diet plus ethanol and fish oil gavages for 8 wk.Betaine was administered intragastrically after exposure of ethanol for 4 wk.The changes of liver histology were examined.The expression of TLR4 mRNA and protein was detected by RT-PCR and Western blotting,respectively.The serum aminotransferase activity alanine transarninase(ALT),aspartate aminotransferase(AST),serum endotoxin,and liver inflammatory factors tumor necrosis factor-α(TNF-α),interferon-γ(IFN-γ),interleukin-18(IL-18)were also assayed.RESULTS:Compared with control group,rats of model group developed marked liver injury,accompanied by an increase of ALT(159.41±7.74 U/L vs 59.47± 2.34 U/L,P<0.0001),AST(248.25±1.40 U/L vs 116.89±3.48 U/L,P<0.0001),endotoxin(135.37± 30.17 ng/L vs 44.15±7.54 ng/L,P<0.0001),TNF-α(20.81±8.58 pg/mL vs 9.34±2.57 pg/mL,P=0.0003),IFN-γ(30.18±7.60 pg/mL vs 16.86±9.49 pg/mL,P= 0.0039)and IL-18(40.99±8.25 pg/mL vs 19.73±9.31 pg/mL,P=0.0001).At the same time,the expression of TLR4 mRNA and protein was markedly induced in the liver after chronic ethanol consumption(1.45±0.07 vs 0.44±0.04,P<0.0001;1.83±0.13 vs 0.56±0.08,P<0.0001).Compared with model group,betaine feeding resulted in significant decreases of ALT(64.93 ±6.06 U/L vs 159.41±7.74 U/L,P<0.0001),AST(188.73±1.11 U/L vs 248.25±1.40 U/L,P<0.0001),endotoxin(61.80±12.56 ng/L vs 135.37±30.17 ng/L,P<0.0001),TNF-α(9.79±1.32 pg/mL vs 20.81± 8.58 pg/mL,P=0.0003),IFN-γ(18.02±5.96 pg/mL vs 30.18±7.60 pg/mL,P=0.0008)and IL-18(18.23±7.01 pg/mL vs 40.99±8.25 pg/mL,P<0.0001).Betaine also improved liver steatosis.The expression levels of TLR4 mRNA or protein in liver tissues were significantly lowered(0.62±0.04 vs 1.45±0.07,P<0.0001;and 0.65±0.06 vs 1.83±0.13,P<0.0001).There was a statistical difference of TLR4 mRNA and protein expression between high-and low-dose betaine groups(0.62±0.04 vs 0.73±0.05,P<0.0001,and 0.65±0.06 vs 0.81±0.09,P<0.0001).CONCLUSION:Betaine can prevent the alcoholinduced liver injury effectively and improve the liver function.The expression of TLR4 increases significantly in ethanol-fed rats and betaine administration can inhibit TLR4 expression.展开更多
AIM: Crohn's disease(CD)and ulcerative colitis(UC)are multifactorial diseases with a significant genetic background.Apart from CARD15/NOD2 gene, evidence is accumulating that molecules related to the innate immune...AIM: Crohn's disease(CD)and ulcerative colitis(UC)are multifactorial diseases with a significant genetic background.Apart from CARD15/NOD2 gene, evidence is accumulating that molecules related to the innate immune response such as CD14 or Toll-like receptor 4 (TLR4), are involved in their pathogenesis. In further exploring the genetic background of these diseases, we investigated the variations in the CARD15/NOD2 gene (Arg702Trp,Gly908Arg and Leu1007fsinsC), and polymorphisms in the TLR4 gene (Asp299Gly and Thr399Ile) as well as in the promoter of the CD14 gene (T/C at position -159) in Greek patients with CD and UC.METHODS: DNA was obtained from 120 patients with CD,85 with UC and 100 healthy individuals. Genotyping was performed by allele specific PCR or by PCR-RFLP analysis.RESULTS: The 299Gly allele frequency of the TLR4 gene and the T allele and TT genotype frequendes of the CD14 promoter were significantly higher in CD patients only compared to healthy individuals (P = 0.026＜0.05; P = 0.0048＜0.01 and P= 0.047＜0.05 respectively). Concerning the NOD2/CARD15mutations the overall presence in CD patients was significantly higher than that in UC patients or in controls.Additionally, 51.67% of the CD patients were carriers of a TLR4 and/or CD14 polymorphic allele and at least one variant of the NOD2/CARD15, compared to 27% of the UC patients. It should be pointed out that both frequencies significantly increased as compared with the 10% frequency of multiple carriers found in healthy controls. A possible interaction of the NOD2/CARD15 with TLR4 and especially CD14, increased the risk of developing inflammatory bowel disease (IBD).CONCLUSION: Our results indicate that co-existence of a mutation in either the TLR4 or CD14 gene, and in NOD2/CARD15is associated with an increased susceptibility to developing CD compared to UC, and to developing either CD or UC compared to healthy individuals.展开更多
AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 5...AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.展开更多
AIM:To elucidate the effect of rapamycin on regulating the production of interleukin(IL)-1β in Aspergillus fumigatus(A.fumigatus)-induced keratitis and to verify whether the expression of IL-1β in A.fumigatus kerati...AIM:To elucidate the effect of rapamycin on regulating the production of interleukin(IL)-1β in Aspergillus fumigatus(A.fumigatus)-induced keratitis and to verify whether the expression of IL-1β in A.fumigatus keratitis is associated with the mammalian target of rapamycin(mT OR)/Toll-like receptor 4(TLR4) signaling pathway.METHODS:Fungal keratitis mouse models of susceptible C57 BL/6 mice were established using A.fumigatus.The mice were subsequently treated with rapamycin.The protein levels of p-mT OR,TLR4,and IL-1β in normal and infected corneal tissue were measured by Western blot.The TLR4 and IL-1β m RNA levels were determined by real-time polymerase chain reaction(PCR).RESULTS:In C57 BL/6 mice,rapamycin treatment decreased the clinical scores and production of the pro-inflammatory cytokine,IL-1β.The expression of TLR4,stimulated by A.fumigatus,was reduced as well when the mT OR signaling pathway was suppressed by rapamycin.CONCLUSION:Rapamycin is beneficial for the outcome of fungal keratitis and has an inhibitory effect expression of the inflammatory cytokine IL-1β.The inhibitory effect on IL-1β expression can be associated with the mT OR/TLR4 signaling pathway in A.fumigatus infection in mice.展开更多
Background:Gram-negative bacterial infections have a major economic impact on both the livestock industry and public health.Toll-like receptor 4(TLR4)plays a crucial role in host defence against Gram-negative bacteria...Background:Gram-negative bacterial infections have a major economic impact on both the livestock industry and public health.Toll-like receptor 4(TLR4)plays a crucial role in host defence against Gram-negative bacteria.Exploring the defence mechanism regulated by TLR4 may provide new targets for treatment of inflammation and control of bacterial infections.In a previous study,we generated transgenic sheep overexpressing TLR4 by microinjection to improve disease resistance.The defence mechanism through which TLR4 overexpression protected these sheep against pathogens is still not fully understood.Results:In the present study,we used Escherichia coli to infect monocytes isolated from peripheral blood of the animal model.The overexpression of TLR4 strongly enhanced the percentage of endocytosis and capacity of elimination in monocytes during the early stages of infection.This phenomenon was mainly due to overexpression of TLR4 promoting caveolae-mediated endocytosis.Pretreatment of the transgenic sheep monocytes with inhibitors of TLR4,Src signalling,or the caveolae-mediated endocytosis pathway reduced the internalization of bacteria,weakened the ability of the monocytes to eliminate the bacteria,and increased the pH of the endosomes.Conclusion:Together,our results reveal the effects of TLR4 on the control of E.coli infection in the innate immunity of sheep and provide crucial evidence of the caveolae-mediated endocytosis pathway required for host resistance to invading bacteria in a large animal model,providing theoretical support for breeding disease resistance in the future.Furthermore,Src and caveolin 1(CAV1)could be potentially valuable targets for the control of infectious diseases.展开更多
Objective:To observe the presence of toll-like receptor 4(TLR4)gene polymorphism in the venous blood in patients with sepsis,meanwhile,to observe the expression and the diagnostic value of TLR4 mRNA,interferon-(IFN-),...Objective:To observe the presence of toll-like receptor 4(TLR4)gene polymorphism in the venous blood in patients with sepsis,meanwhile,to observe the expression and the diagnostic value of TLR4 mRNA,interferon-(IFN-),interleukin-23(IL-23),procalcitonin(PCT)and C-reactive protein(CRP)in patients with different degrees of sepsis.Methods:The peripheral blood samples from the subjects were collected to extract genomic DNA,gene sequencing and enzyme digestion method were applied to the detection of TLR4 Asp299Gly loci polymorphism.The expression of TLR4 mRNA in the peripheral blood was detected by reverse transcriptase polymerase chain reaction(RT-PCR).The expression levels of IFN-,IL-23,PCT and CRP were measured by enzyme linked immunosorbent assay(ELISA).Results:(1)The gene polymorphism was not present in TLR4 Asp299Gly loci;(2)The expression of TLR4 mRNA in the peripheral blood in patients with sepsis:on d1,there were statistically significant differences between the normal group and the group(APACHE II≤20),between the normal group and the group(APACHE II>20),between the group(APACHE II≤20)and the group(AAPACHE II>20)(t=5.741,14.780 and 10.500,all p<.01).APACHE II stands for Acute Physiology and Chronic Health Evaluation II.On d7,there were statistically significant differences between the normal group and the group(APACHE II≤20),between the normal group and the group(APACHE II>20),between the group(APACHE II≤20)and the group(APACHE II>20)(t=4.186,13.830 and 9.645,all p<.01);(3)The expression levels of IFN-,IL-23,PCT and CRP were obviously upregulated(all p<.01),and TLR4 was positively correlated with IFN-and IL-23(all p<.01);(4)The best cutoff value of TLR4 mRNA at baseline was 891.6μg/L,with a sensitivity of 100%and a diagnostic specificity of 57%.The best cutoff value of IFN-at baseline was 84.5μg/L,with a sensitivity of 100%and a diagnostic specificity of 57%.The best cutoff value of IL-23 at baseline was 861μg/L,with a sensitivity of 100%and a diagnostic specificity of 97%.Conclusions:(1)The Asp299Gly polymorphism is not present in TLR4 gene;(2)The expression levels of TLR4 mRNA,IFN-and IL-23 are relatively high in patients with sepsis,and will be higher with the increased severity of sepsis;(3)TLR4 mRNA,IFN-and IL-23 can be used as molecular biomarkers for the early diagnosis of sepsis.展开更多
Osteonecrosis of the femoral head is frequently observed in patients treated with excessive corticosteroids. However, the pathogenesis of corticosteroid-induced osteonecrosis remains unclear. The purpose of this study...Osteonecrosis of the femoral head is frequently observed in patients treated with excessive corticosteroids. However, the pathogenesis of corticosteroid-induced osteonecrosis remains unclear. The purpose of this study was to investigate the role of Toll-like receptor 4(TLR4) signaling pathway in steroid-induced femoral head osteonecrosis in rats. Male Sprague-Dawley rats were injected intramuscularly with 20 mg/kg methylprednisolone(MP) for 8 weeks, twice per week. The animals were sacrificed at 2, 4 and 8 weeks after the last MP injection, respectively, and then allocated to the 2-, 4- and 8-week model groups(n=24 each). Rats in the control group(n=12) were not given any treatment. Histopathological analysis was performed and the concentration of tartrate-resistant acid phosphatase(TRAP) in plasma was determined. The activation of osteoclasts in the femoral head was assessed by TRAP staining. The expression of TLR4, MyD88, TRAF6 and NF-κB p65 that are involved in TLR4 signaling, and MCP-1 production were detected by using real-time PCR(RT-PCR) and Western blotting. The results showed that the osteonecrosis in the femoral head was clearly observed and the concentration of TRAP in the plasma was increased in the model rats. The femoral head tissues in MP-treated rats were positive for TRAP and the intensity of TRAP staining was greater in MP-treated rats than in control rats. As compared with the control group, the mRNA expression of TLR4 signaling-related factors was enhanced significantly at 4 and 8 weeks, and the protein levels of these factors increased significantly with time. It was concluded that MP could induce the femoral head osteonecrosis in rats, which was associated with osteoclast activation via the TLR4 signaling pathway. These findings suggest that TLR4 signaling pathway plays a pivotal role in the pathogenesis of steroid-induced osteonecrosis.展开更多
AIM: To investigate the effect of Lactobacillus bulgaricus (LBG) on the Toll-like receptor 4 (TLR4) pathway and interleukin-8 (IL-8) production in SGC-7901 cells treated with Helicobacter pyloriSydney strain 1 lipopol...AIM: To investigate the effect of Lactobacillus bulgaricus (LBG) on the Toll-like receptor 4 (TLR4) pathway and interleukin-8 (IL-8) production in SGC-7901 cells treated with Helicobacter pyloriSydney strain 1 lipopolysaccharide (HpyloriSS1-LPS). METHODS: SGC-7901 cells were treated with Hpylori SS1-LPS in the presence or absence of pretreatment for 1 h with viable LBG or supernatant recovered from LBG culture MRS broth (LBG-S). Cellular lysates were prepared for Western blot with anti-TLR4, anti-transforming growth factor β-activated kinase 1 (TAK1), anti-phospho-TAK1, anti-nuclear factor κB (NF-κB), anti-p38 mitogen-activated protein kinase (p38MAPK), and anti-phospho-p38MAPK antibodies. The amount of IL-8 in cell culture medium was measured by ELISA. RESULTS: H pylori SS1-LPS up-regulated the expression of TLR4, stimulated the phosphorylation of TAK1, subsequently enhanced the activation of NF- κB and the phosphorylation of p38MAPK in a time- dependent manner, leading to augmentation of IL-8 production in SGC-7901 cells. Viable LBG or LBG-S pretreatment attenuated the expression of TLR4, inhibited the phosphorylation of TAK1 and p38MAPK, prevented the activation of NF-κB, and consequently blocked IL-8 production.CONCLUSION: H pylori SS1-LPS induces IL-8 production through activating TLR4 signaling in SGC-7901 cells and viable LBG or LBG-S prevents H pyloriSS1-LPS-mediated IL-8 production via inhibition of the TLR4 pathway.展开更多
This study investigated the effects of propofol on the mRNA expression of Toll-like receptor-4 (TLR4) in BV-2 cells during mimic ischemia-reperfusion (I/R) injury in vitro. BV-2 cells, a mouse microglia line, were cul...This study investigated the effects of propofol on the mRNA expression of Toll-like receptor-4 (TLR4) in BV-2 cells during mimic ischemia-reperfusion (I/R) injury in vitro. BV-2 cells, a mouse microglia line, were cultured and divided into 4 groups at random: control group (group C), ischemia/reperfusion group (group I/R), low-dose propofol (25 μmol/L) intervention group (group PF25) and high-dose propofol (100 μmol/L) intervention group (group PF100). The mRNA expression of TLR4 and NF-κB was measured by means of RT-PCR. TNF-α levels in the supernatants of BV-2 cells were detected by ELISA. The results showed that the mRNA expression of TLR4 and NF-κB was significantly higher in groups I/R, PF25 and PF100 than in group C (P<0.01). And the TNF-α level in the supernatants was elevated in groups I/R, PF25 and PF100 as compared with that in group C (P<0.01). After pre-treatment with propofol, the mRNA expressions of TLR4 and NF-κB and the TNF-α level were significantly decreased in groups PF25 and PF100 in comparison to those in group I/R (P<0.01). And the decrease in those indicators was more significant in group PF100 than in group PF25 (P<0.01). It was concluded that propofol exerted brain-protecting effects during I/R injury by suppressing the mRNA expressions of TLR4 and NF-κB and deceasing the TNF-α level.展开更多
The phosphatidylinositol 3 kinase(PI3K)/protein kinase B(AKT)signaling pathway is considered important for cell survival and has been shown to mediate various anti-apoptotic biological effects.This study explored the ...The phosphatidylinositol 3 kinase(PI3K)/protein kinase B(AKT)signaling pathway is considered important for cell survival and has been shown to mediate various anti-apoptotic biological effects.This study explored the role of the Toll-like receptor 4(TLR4)-mediated PI3K/AKT-glycogen synthase kinase 3β(GSK-3β)signaling pathways in lipopolysaccharide-induced apoptosis in a primary culture of hippocampal neurons.Results demonstrated that the apoptotic ratio of hippocampal neurons stimulated by lipopolysaccharide was significantly higher compared with the control group.Both the expression of P-AKTSer473and P-GSK-3βSer9in hippocampal neurons stimulated by lipopolysaccharide decreased compared with the control,while the level of active Caspase-3 and the ratio of Bax/Bcl-2 were significantly increased.The level of active Caspase-3 and the ratio of Bax/Bcl-2 in hippocampal neurons treated with TLR4 antibody or the GSK-3βinhibitor,LiCl,decreased before intervention with lipopolysaccharide,but increased after treatment with the AKT inhibitor,LY294002.These findings suggest that the TLR4-PI3K/AKT-GSK3βsignaling pathway may be involved in lipopolysaccharide-induced apoptosis of hippocampal neurons.展开更多
Objective:Inflammation induced by H.pylori colonization in the stomach is related to the development of gastric cancer and the genetic variations of the genes involved in the immune responses modify the host response ...Objective:Inflammation induced by H.pylori colonization in the stomach is related to the development of gastric cancer and the genetic variations of the genes involved in the immune responses modify the host response to the infection. The aim of this study was to evaluate whether polymorphisms in the toll-like receptor 4 (TLR4) gene, a key regulator of both innate and adaptive immunity, were related to the susceptibility togastric cancer in a Chinese population. Methods: Two variations in the 5'-flanking region of TLR4 (rs1927914 T>C and rs10759932 T>C) were genotyped by using the PCR-restriction fragment length polymorphism (RFLP) assay in a case-control study of 1,053 incident gastric cancer cases and 1,100 cancer-free controls in a Chinese population. Results: Individuals carrying the C allele of rs10759932 had a significantly reduced risk of gastric cancer (adjusted OR=0.81; 95%CI=0.67-0.96), compared with the wild-type homozygote (TT), and the protective effect was not significantly different among subgroups stratified by age, sex, smoking, drinking and H.pylori infection status (P for heterogeneity >0.05). No significant association was observed between rs1927914 and gastric cancer risk in this study population. Conclusion: The T to C allele substitution of rs10759932 may play a protective role in gastric carcinogenesis in a Chinese population. Large studies with different ethnic populations are warranted to confirm these findings.展开更多
AIM: To evaluate the role of genetic factors in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC), we investigated the single nucleotide poly- morphisms (SNPs) of NOD2/CARD15 (R702W, G908R and L...AIM: To evaluate the role of genetic factors in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC), we investigated the single nucleotide poly- morphisms (SNPs) of NOD2/CARD15 (R702W, G908R and L1007fi nsC), and Toll-like receptor 4 (TLR4) genes (D299G and T399I) in a selected inflammatory bowel disease (IBD) population coming from Southern Italy. METHODS: Allele and genotype frequencies of NOD2/ CARD15 (R702W, G908R and L1007finsC) and TLR4 (D299G and T399I) SNPs were examined in 133 CD pa-tients, in 45 UC patients, and in 103 healthy controls. A genotype-phenotype correlation was performed. RESULTS: NOD2/CARD15 R702W mutation was sig-nificantly more frequent in CD (9.8%) than in controls (2.4%, P = 0.001) and in UC (2.3%, P = 0.03). No sig-nificant difference was found between UC patients and control group (P > 0.05). In CD and UC patients, no signifi cant association with G908R variant was found. L1007f insC SNP showed an association with CD (9.8%) compared with controls (2.9%, P = 0.002) and UC patients (2.3%, P = 0.01). Moreover, in CD patients, G908R and L1007finsC mutations were significantly associated with different phenotypes compared to CD wild-type patients. No association of IBD with the TLR4 SNPs was found in either cohort (allele frequencies: D299G-controls 3.9%, CD 3.7%, UC 3.4%, P > 0.05; T399I-controls 2.9%, CD 3.0%, UC 3.4%, P > 0.05). CONCLUSION: These findings confirm that, in our IBD patients selected from Southern Italy, the NOD2/ CARD15, but not TLR4 SNPs, are associated with in-creased risk of CD.展开更多
Toll-like receptors(TLRs) are key components of the innate immune system which trigger antimicrobial host defense responses. This study aimed to investigate the impact of probiotics(Lactobacillus, Bifiidobacterium) on...Toll-like receptors(TLRs) are key components of the innate immune system which trigger antimicrobial host defense responses. This study aimed to investigate the impact of probiotics(Lactobacillus, Bifiidobacterium) on the expression of TLR4 and tumor necrosis factor-alpha(TNF-α) in the colon mucosa of rat experimental ulcerative colitis model induced by trinitrobenzene sulfonic acid(TNBS)/ethanol and immune complexes. The gross and histological changes of the colonic mucosa were observed and assessed by the means-standard deviation and independent samples t-test. The protein expression levels of TLR4 and TNF-α were detected by using immunohistochemistry and Western blotting, respectively. It was revealed that there was visible infiltration of inflammatory cells, formation of crypt abscess, and the reduction of goblet cells in the colon tissue of experimental models. As compared with the control group, the levels of TLR4 and TNF-α protein were significantly increased in the model group(P<0.01 for both). No significant difference was found in the expression of TLR4 and TNF-α between the two-week probiotics treatment group and the model group(P>0.05), whereas significant reductions were shown in rats which were treated with probiotics for four weeks as compared with the model group(P<0.01). There was no significant difference between two probiotics-treated groups. Our results implied that probiotics were likely to play a key role in protecting ulcerative colitis by reducing the inflammatory factor TNF-α expression through inhibiting the TLR4 expression in the colon tissue of experimental models.展开更多
This study investigated the expression and immune effect of TLR4 in human trophoblast cells. The expression level of TLR4 mRNA in normal and LPS-stimulated human term trophoblast cells (1 mg/L LPS, 12 h) was detected ...This study investigated the expression and immune effect of TLR4 in human trophoblast cells. The expression level of TLR4 mRNA in normal and LPS-stimulated human term trophoblast cells (1 mg/L LPS, 12 h) was detected by RT-PCR. In LPS-stimulated human term trophoblast cells of TLR4-blocked group and non-TLR4-blocked group, and normal term trophoblast cells of blank control group, apoptosis rate was measured by flow cytometry (FCM), and the level of TNF-α deter-mined by using enzyme linked immunosorbent assay (ELISA) respectively. RT-PCR results showed that the expression level of TLR4 mRNA in LPS-stimulated human trophoblast cells was signifi-cantly higher than that in normal cells (P<0.01). FCM revealed that there was significant difference in apoptosis rate of LPS-stimulated human term trophoblast cells between TLR4-blocked group and non-TLR4-blocked group (P<0.05), or between TLR4 antibody-blocked group and blank control group. ELISA indicated that the level of TNF-α in LPS-stimulated human trophoblast cells also had statistical differences between TLR4 antibody-blocked group and non-TLR4 antibody-blocked group (P<0.05). Our results suggest that TLR4 plays an important role in the immunological mechanism of apoptosis and secretion of TNF-α of human term trophoblast cells stimulated by LPS.展开更多
AIM To assess the relationship between the presence of toll-like receptor 4(TLR4) polymorphisms and bacterial infections in cirrhotic patients with ascites. METHODS We prospectively included consecutive patients with ...AIM To assess the relationship between the presence of toll-like receptor 4(TLR4) polymorphisms and bacterial infections in cirrhotic patients with ascites. METHODS We prospectively included consecutive patients with cirrhosis and ascites hospitalized during a 6-year period. Patients with human immunodeficiency virus(HIV) infection or any other immunodeficiency, patients with advanced hepatocellular carcinoma(beyond Milan's criteria) or any other condition determining poor short-term prognosis, and patients with a permanent urinary catheter were excluded. The presence of D299 G and/or T399 I TLR4 polymorphisms was determined by sequencing and related to the incidence and probability of bacterial infections, other complications of cirrhosis, hepatocellular carcinoma, and mortality during follow-up. A multivariate analysis to identify predictive variables of mortality in the whole series was performed. RESULTS We included 258 patients: 28(10.8%) were carriers of D299G and/or T399I TLR4 polymorphisms(polymorphism group) and 230 patients were not(wildtype group). The probability of developing any bacterial infection at one-year follow-up was 78% in the polymorphism group and 69% in the wild-type group(P = 0.54). The one-year probability of presenting infections caused by gram-negative bacilli(51% vs 44%, P = 0.68), infections caused by gram-positive cocci(49% vs 40%, P = 0.53), and spontaneous bacterial peritonitis(29% vs 34%, respectively, P = 0.99) did not differ between the two groups. The oneyear probability of transplant-free survival was 55% in the polymorphism group and 66% in the wild-type group(P = 0.15). Multivariate analysis confirmed that age, Child-Pugh score, active alcohol intake, previous hepatic encephalopathy, hepatocellular carcinoma and serum creatinine were associated with a higher risk of death during follow-up. CONCLUSION Genetic polymorphisms D299 G and/or T399 I of TLR4 do not seem to play a relevant role in the predisposition of cirrhotic patients with ascites to bacterial infections.展开更多
Objective: To explore the effects of transforming growth factor β1(TGF-β1) on dendritic cells (DC). Methods: Murine bone marrow cells were cultured with GM-CSF and TGF-β1 to develop TGF-β1-treated DC (TGFβ-DC). T...Objective: To explore the effects of transforming growth factor β1(TGF-β1) on dendritic cells (DC). Methods: Murine bone marrow cells were cultured with GM-CSF and TGF-β1 to develop TGF-β1-treated DC (TGFβ-DC). Then they were stimulated by lipopolysaccharide (LPS). Their phenotypes were assessed by flow cytometry (FCM). The allogeneicstimulating capacity of DC was measured by mixed lymphocyte reaction (MLR) using BrdU ELISA method and IL-12p70 protein was detected by ELISA. The expression of Toll-like receptor 4 (TLR4) was analyzed by semi quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and FCM. Results: Compared to immature DC (imDC) cultured by GM-CSF alone, the TGFβ-DC express lower CD80, CD86, I-A^b and CD40. The TGFβ-DC were resistant to maturation with LPS. Maturation resistance was evident from a failure to up-regulate co-stimulatory molecules (CMs), to stimulate larger T cells proliferation and to enhance secretion of IL-12p70. We also found that TGF-β1 could down-regulate TLR4 expression on TGFβ-DC. Conclusion: TGFβ-DC are resistant to maturation stimulus (LPS) and might have some correlation with the down-modulation of TLR4 expression.展开更多
The expression of Toll-like receptor 4 (TLR4) in neonatal cord blood mononuclear cells (MNCs) and serum TNF-α were investigated in order to explore the roles of TLR4 in the pathogenesis of preeclampsia.The study enro...The expression of Toll-like receptor 4 (TLR4) in neonatal cord blood mononuclear cells (MNCs) and serum TNF-α were investigated in order to explore the roles of TLR4 in the pathogenesis of preeclampsia.The study enrolled 27 patients suffering from preeclampsia (experimental group) and 21 normal pregnancy patients (control group).After MNCs were separated, the expression of TLR4 mRNA and protein was detected by using real-time quantitative PCR and Western blotting respectively, and the expression of TNF-α by using ELISA.The results showed the TLR4 mRNA level in cord blood MNCs (2-CT:0.07±0.17), TLR4 protein expression level (absorbance ratio:0.81%±0.15%) and TNF-α level (9.5±1.73 pg/mL) were all increased in experimental group as compared with control group with the differences being statistically significant (P<0.05).There was a positive correlation between the expression of TLR4 mRNA and TNF-α in both experimental group and control group (r=0.54 and 0.53, respectively, P<0.05).It was concluded that TLR4 expression in the experimental group of cord blood MNCs was increased and there was a positive correlation between the expression of TLR4 mRNA and TNF-α in both groups.TLR4-mediated release of inflammatory cytokines may be one of the important reasons leading to preeclampsia.展开更多
基金Supported by the Huadong Medicine Joint Funds of the Zhejiang Provincial Natural Science Foundation of China,No.LHDMZ22H050001the Construction of Key Projects by Zhejiang Provincial Ministry,No.WKJ-ZJ-2302+3 种基金the Zhejiang Province Chinese Medicine Modernization Program,No.2020ZX001the Key Project of Scientific Research Foundation of Chinese Medicine,No.2022ZZ002the“Pioneer”and“LeadingGoose”R&D Program of Zhejiang,No.2022C03118 and 2023C03075the Key Project of Basic Scientific Research Operating Funds of Hangzhou Medical College,No.KYZD202002.
文摘BACKGROUND Diabetic kidney disease(DKD)is a major complication of diabetes mellitus.Renal tubular epithelial cell(TEC)damage,which is strongly associated with the inflammatory response and mesenchymal trans-differentiation,plays a significant role in DKD;However,the precise molecular mechanism is unknown.The recently identified microRNA-630(miR-630)has been hypothesized to be closely associated with cell migration,apoptosis,and autophagy.However,the association between miR-630 and DKD and the underlying mechanism remain unknown.AIM To investigate how miR-630 affects TEC injury and the inflammatory response in DKD rats.METHODS Streptozotocin was administered to six-week-old male rats to create a hypergly cemic diabetic model.In the second week of modeling,the rats were divided into control,DKD,negative control of lentivirus,and miR-630 overexpression groups.After 8 wk,urine and blood samples were collected for the kidney injury assays,and renal tissues were removed for further molecular assays.The target gene for miR-630 was predicted using bioinformatics,and the association between miR-630 and toll-like receptor 4(TLR4)was confirmed using in vitro investigations and double luciferase reporter gene assays.Overexpression of miR-630 in DKD rats led to changes in body weight,renal weight index,basic blood parameters and histopathological changes.RESULTS The expression level of miR-630 was reduced in the kidney tissue of rats with DKD(P<0.05).The miR-630 and TLR4 expressions in rat renal TECs(NRK-52E)were measured using quantitative reverse transcription polymerase chain reaction.The mRNA expression level of miR-630 was significantly lower in the high-glucose(HG)and HG+mimic negative control(NC)groups than in the normal glucose(NG)group(P<0.05).In contrast,the mRNA expression level of TLR4 was significantly higher in these groups(P<0.05).However,miR-630 mRNA expression increased and TLR4 mRNA expression significantly decreased in the HG+miR-630 mimic group than in the HG+mimic NC group(P<0.05).Furthermore,the levels of tumor necrosis factor-alpha(TNF-α),interleukin-1β(IL-1β),and IL-6 were significantly higher in the HG and HG+mimic NC groups than in NG group(P<0.05).However,the levels of these cytokines were significantly lower in the HG+miR-630 mimic group than in the HG+mimic NC group(P<0.05).Notably,changes in protein expression were observed.The HG and HG+mimic NC groups showed a significant decrease in E-cadherin protein expression,whereas TLR4,α-smooth muscle actin(SMA),and collagen IV protein expression increased(P<0.05).Conversely,the HG+miR-630 mimic group exhibited a significant increase in E-cadherin protein expression and a notable decrease in TLR4,α-SMA,and collagen IV protein expression than in the HG+mimic NC group(P<0.05).The miR-630 targets TLR4 gene expression.In vivo experiments demonstrated that DKD rats treated with miR-630 agomir exhibited significantly higher miR-630 mRNA expression than DKD rats injected with agomir NC.Additionally,rats treated with miR-630 agomir showed significant reductions in urinary albumin,blood glucose,TLR4,and proinflammatory markers(TNF-α,IL-1β,and IL-6)expression levels(P<0.05).Moreover,these rats exhibited fewer kidney lesions and reduced infiltration of inflammatory cells.CONCLUSION MiR-630 may inhibit the inflammatory reaction of DKD by targeting TLR4,and has a protective effect on DKD.
基金the Scientific Research Project of Jiangsu Provincial Health Commission,No.H2018082Huai’an Natural Science Research Project Project,No.HAB201926Scientific Research Project of Translational Medicine Innovation Team of Huai’an First People’s Hospital,No.YZHT201905.
文摘BACKGROUND Fecal microbiota transplantation(FMT)has shown promising therapeutic effects on mice with experimental colitis and patients with ulcerative colitis(UC).FMT modulates the Toll-like receptor 4(TLR4)signaling pathway to treat some other diseases.However,it remains unknown whether this modulation is also involved in the treatment of UC.AIM To clarify the necessity of TLR4 signaling pathway in FMT on dextran sodium sulphate(DSS)-induced mice and explain the mechanism of FMT on UC,through association analysis of gut microbiota with colon transcriptome in mice.METHODS A mouse colitis model was constructed with wild-type(WT)and TLR4-knockout(KO)mice.Fecal microbiota was transplanted by gavage.Colon inflammation severity was measured by disease activity index(DAI)scoring and hematoxylin and eosin staining.Gut microbiota structure was analyzed through 16S ribosomal RNA sequencing.Gene expression in the mouse colon was obtained by transcriptome sequencing.RESULTS The KO(DSS+Water)and KO(DSS+FMT)groups displayed indistinguishable body weight loss,colon length,DAI score,and histology score,which showed that FMT could not inhibit the disease in KO mice.In mice treated with FMT,the relative abundance of Akkermansia decreased,and Lactobacillus became dominant.In particular,compared with those in WT mice,the scores of DAI and colon histology were clearly decreased in the KO-DSS group.Microbiota structure showed a significant difference between KO and WT mice.Akkermansia were the dominant genus in healthy KO mice.The ineffectiveness of FMT in KO mice was related to the decreased abundance of Akkermansia.Gene Ontology enrichment analysis showed that differentially expressed genes between each group were mainly involved in cytoplasmic translation and cellular response to DNA damage stimulus.The top nine genes correlating with Akkermansia included Aqp4,Clca4a,Dpm3,Fau,Mcrip1,Meis3,Nupr1 L,Pank3,and Rps13(|R|>0.9,P<0.01).CONCLUSION FMT may ameliorate DSS-induced colitis by regulating the TLR4 signaling pathway.TLR4 modulates the composition of gut microbiota and the expression of related genes to ameliorate colitis and maintain the stability of the intestinal environment.Akkermansia bear great therapeutic potential for colitis.
基金supported by a Grant-in-Aid for Scientific Research from Mie Medical Research Foundation to Dr.Suzuki
文摘Neuroinflammation is a well-recognized consequence of subarachnoid hemorrhage(SAH), and Toll-like receptor(TLR) 4 may be an important therapeutic target for post-SAH neuroinflammation. Of the TLR family members, TLR4 is expressed in various cell types in the central nervous system, and is unique in that it can signal through both the myeloid differentiation primary-response protein 88-dependent and the toll receptor associated activator of interferon-dependent cascades to coordinate the maximal inflammatory response. TLR4 can be activated by many endogenous ligands having damage-associated molecular patterns including heme and fibrinogen at the rupture of an intracranial aneurysm, and the resultant inflammatory reaction and thereby tissue damages may furthermore activate TLR4. It is widely accepted that the excreted products of TLR4 signaling alter neuronal functions. Previous studies have focused on the pathway through nuclear factor(NF)-κΒ signaling among TLR4 signaling pathways as to the development of early brain injury(EBI) such as neuronal apoptosis and blood-brain barrier disruption, and cerebral vasospasm. However, many findings suggest that both pathways via NF-κΒ and mitogen-activated protein kinases may be involved in EBI and cerebral vasospasm development. To overcome EBI and cerebral vasospasm is important to improve outcomes after SAH, because both EBI and vasopasm are responsible for delayed brain injuries or delayed cerebral ischemia, the most important preventable cause of poor outcomes after SAH. Increasing evidence has shown that TLR4 signaling plays an important role in SAH-induced brain injuries. Better understanding of the roles of TLR4 signaling in SAH will facilitate development of new treatments.
文摘AIM:To test whether ethanol feeding could induce Toll-like receptor 4(TLR4)responses,assess the hepatoprotective effect of betaine and its inhibitive effect on TLR4 in animal models of alcoholic liver injury.METHODS:Forty-eight female Sprague-Dawley rats were randomly divided into four groups as control,model,low and high dose betaine groups.Except control group,all rats were fed with high fat-containing diet plus ethanol and fish oil gavages for 8 wk.Betaine was administered intragastrically after exposure of ethanol for 4 wk.The changes of liver histology were examined.The expression of TLR4 mRNA and protein was detected by RT-PCR and Western blotting,respectively.The serum aminotransferase activity alanine transarninase(ALT),aspartate aminotransferase(AST),serum endotoxin,and liver inflammatory factors tumor necrosis factor-α(TNF-α),interferon-γ(IFN-γ),interleukin-18(IL-18)were also assayed.RESULTS:Compared with control group,rats of model group developed marked liver injury,accompanied by an increase of ALT(159.41±7.74 U/L vs 59.47± 2.34 U/L,P<0.0001),AST(248.25±1.40 U/L vs 116.89±3.48 U/L,P<0.0001),endotoxin(135.37± 30.17 ng/L vs 44.15±7.54 ng/L,P<0.0001),TNF-α(20.81±8.58 pg/mL vs 9.34±2.57 pg/mL,P=0.0003),IFN-γ(30.18±7.60 pg/mL vs 16.86±9.49 pg/mL,P= 0.0039)and IL-18(40.99±8.25 pg/mL vs 19.73±9.31 pg/mL,P=0.0001).At the same time,the expression of TLR4 mRNA and protein was markedly induced in the liver after chronic ethanol consumption(1.45±0.07 vs 0.44±0.04,P<0.0001;1.83±0.13 vs 0.56±0.08,P<0.0001).Compared with model group,betaine feeding resulted in significant decreases of ALT(64.93 ±6.06 U/L vs 159.41±7.74 U/L,P<0.0001),AST(188.73±1.11 U/L vs 248.25±1.40 U/L,P<0.0001),endotoxin(61.80±12.56 ng/L vs 135.37±30.17 ng/L,P<0.0001),TNF-α(9.79±1.32 pg/mL vs 20.81± 8.58 pg/mL,P=0.0003),IFN-γ(18.02±5.96 pg/mL vs 30.18±7.60 pg/mL,P=0.0008)and IL-18(18.23±7.01 pg/mL vs 40.99±8.25 pg/mL,P<0.0001).Betaine also improved liver steatosis.The expression levels of TLR4 mRNA or protein in liver tissues were significantly lowered(0.62±0.04 vs 1.45±0.07,P<0.0001;and 0.65±0.06 vs 1.83±0.13,P<0.0001).There was a statistical difference of TLR4 mRNA and protein expression between high-and low-dose betaine groups(0.62±0.04 vs 0.73±0.05,P<0.0001,and 0.65±0.06 vs 0.81±0.09,P<0.0001).CONCLUSION:Betaine can prevent the alcoholinduced liver injury effectively and improve the liver function.The expression of TLR4 increases significantly in ethanol-fed rats and betaine administration can inhibit TLR4 expression.
基金Supported by the EU Project "Sacrohn" N. QLK2-CT-2000-00928.
文摘AIM: Crohn's disease(CD)and ulcerative colitis(UC)are multifactorial diseases with a significant genetic background.Apart from CARD15/NOD2 gene, evidence is accumulating that molecules related to the innate immune response such as CD14 or Toll-like receptor 4 (TLR4), are involved in their pathogenesis. In further exploring the genetic background of these diseases, we investigated the variations in the CARD15/NOD2 gene (Arg702Trp,Gly908Arg and Leu1007fsinsC), and polymorphisms in the TLR4 gene (Asp299Gly and Thr399Ile) as well as in the promoter of the CD14 gene (T/C at position -159) in Greek patients with CD and UC.METHODS: DNA was obtained from 120 patients with CD,85 with UC and 100 healthy individuals. Genotyping was performed by allele specific PCR or by PCR-RFLP analysis.RESULTS: The 299Gly allele frequency of the TLR4 gene and the T allele and TT genotype frequendes of the CD14 promoter were significantly higher in CD patients only compared to healthy individuals (P = 0.026＜0.05; P = 0.0048＜0.01 and P= 0.047＜0.05 respectively). Concerning the NOD2/CARD15mutations the overall presence in CD patients was significantly higher than that in UC patients or in controls.Additionally, 51.67% of the CD patients were carriers of a TLR4 and/or CD14 polymorphic allele and at least one variant of the NOD2/CARD15, compared to 27% of the UC patients. It should be pointed out that both frequencies significantly increased as compared with the 10% frequency of multiple carriers found in healthy controls. A possible interaction of the NOD2/CARD15 with TLR4 and especially CD14, increased the risk of developing inflammatory bowel disease (IBD).CONCLUSION: Our results indicate that co-existence of a mutation in either the TLR4 or CD14 gene, and in NOD2/CARD15is associated with an increased susceptibility to developing CD compared to UC, and to developing either CD or UC compared to healthy individuals.
基金Supported by Jinling Hospital Research Fund,No.2013064
文摘AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.
基金Supported by the National Natural Science Foundation of China(No.81470609No.81500695)
文摘AIM:To elucidate the effect of rapamycin on regulating the production of interleukin(IL)-1β in Aspergillus fumigatus(A.fumigatus)-induced keratitis and to verify whether the expression of IL-1β in A.fumigatus keratitis is associated with the mammalian target of rapamycin(mT OR)/Toll-like receptor 4(TLR4) signaling pathway.METHODS:Fungal keratitis mouse models of susceptible C57 BL/6 mice were established using A.fumigatus.The mice were subsequently treated with rapamycin.The protein levels of p-mT OR,TLR4,and IL-1β in normal and infected corneal tissue were measured by Western blot.The TLR4 and IL-1β m RNA levels were determined by real-time polymerase chain reaction(PCR).RESULTS:In C57 BL/6 mice,rapamycin treatment decreased the clinical scores and production of the pro-inflammatory cytokine,IL-1β.The expression of TLR4,stimulated by A.fumigatus,was reduced as well when the mT OR signaling pathway was suppressed by rapamycin.CONCLUSION:Rapamycin is beneficial for the outcome of fungal keratitis and has an inhibitory effect expression of the inflammatory cytokine IL-1β.The inhibitory effect on IL-1β expression can be associated with the mT OR/TLR4 signaling pathway in A.fumigatus infection in mice.
基金supported by National Science and Technology Major Project of China(2016ZX08008-003).
文摘Background:Gram-negative bacterial infections have a major economic impact on both the livestock industry and public health.Toll-like receptor 4(TLR4)plays a crucial role in host defence against Gram-negative bacteria.Exploring the defence mechanism regulated by TLR4 may provide new targets for treatment of inflammation and control of bacterial infections.In a previous study,we generated transgenic sheep overexpressing TLR4 by microinjection to improve disease resistance.The defence mechanism through which TLR4 overexpression protected these sheep against pathogens is still not fully understood.Results:In the present study,we used Escherichia coli to infect monocytes isolated from peripheral blood of the animal model.The overexpression of TLR4 strongly enhanced the percentage of endocytosis and capacity of elimination in monocytes during the early stages of infection.This phenomenon was mainly due to overexpression of TLR4 promoting caveolae-mediated endocytosis.Pretreatment of the transgenic sheep monocytes with inhibitors of TLR4,Src signalling,or the caveolae-mediated endocytosis pathway reduced the internalization of bacteria,weakened the ability of the monocytes to eliminate the bacteria,and increased the pH of the endosomes.Conclusion:Together,our results reveal the effects of TLR4 on the control of E.coli infection in the innate immunity of sheep and provide crucial evidence of the caveolae-mediated endocytosis pathway required for host resistance to invading bacteria in a large animal model,providing theoretical support for breeding disease resistance in the future.Furthermore,Src and caveolin 1(CAV1)could be potentially valuable targets for the control of infectious diseases.
文摘Objective:To observe the presence of toll-like receptor 4(TLR4)gene polymorphism in the venous blood in patients with sepsis,meanwhile,to observe the expression and the diagnostic value of TLR4 mRNA,interferon-(IFN-),interleukin-23(IL-23),procalcitonin(PCT)and C-reactive protein(CRP)in patients with different degrees of sepsis.Methods:The peripheral blood samples from the subjects were collected to extract genomic DNA,gene sequencing and enzyme digestion method were applied to the detection of TLR4 Asp299Gly loci polymorphism.The expression of TLR4 mRNA in the peripheral blood was detected by reverse transcriptase polymerase chain reaction(RT-PCR).The expression levels of IFN-,IL-23,PCT and CRP were measured by enzyme linked immunosorbent assay(ELISA).Results:(1)The gene polymorphism was not present in TLR4 Asp299Gly loci;(2)The expression of TLR4 mRNA in the peripheral blood in patients with sepsis:on d1,there were statistically significant differences between the normal group and the group(APACHE II≤20),between the normal group and the group(APACHE II>20),between the group(APACHE II≤20)and the group(AAPACHE II>20)(t=5.741,14.780 and 10.500,all p<.01).APACHE II stands for Acute Physiology and Chronic Health Evaluation II.On d7,there were statistically significant differences between the normal group and the group(APACHE II≤20),between the normal group and the group(APACHE II>20),between the group(APACHE II≤20)and the group(APACHE II>20)(t=4.186,13.830 and 9.645,all p<.01);(3)The expression levels of IFN-,IL-23,PCT and CRP were obviously upregulated(all p<.01),and TLR4 was positively correlated with IFN-and IL-23(all p<.01);(4)The best cutoff value of TLR4 mRNA at baseline was 891.6μg/L,with a sensitivity of 100%and a diagnostic specificity of 57%.The best cutoff value of IFN-at baseline was 84.5μg/L,with a sensitivity of 100%and a diagnostic specificity of 57%.The best cutoff value of IL-23 at baseline was 861μg/L,with a sensitivity of 100%and a diagnostic specificity of 97%.Conclusions:(1)The Asp299Gly polymorphism is not present in TLR4 gene;(2)The expression levels of TLR4 mRNA,IFN-and IL-23 are relatively high in patients with sepsis,and will be higher with the increased severity of sepsis;(3)TLR4 mRNA,IFN-and IL-23 can be used as molecular biomarkers for the early diagnosis of sepsis.
基金supported by the National Natural Science Foundation of China(No.81101363)
文摘Osteonecrosis of the femoral head is frequently observed in patients treated with excessive corticosteroids. However, the pathogenesis of corticosteroid-induced osteonecrosis remains unclear. The purpose of this study was to investigate the role of Toll-like receptor 4(TLR4) signaling pathway in steroid-induced femoral head osteonecrosis in rats. Male Sprague-Dawley rats were injected intramuscularly with 20 mg/kg methylprednisolone(MP) for 8 weeks, twice per week. The animals were sacrificed at 2, 4 and 8 weeks after the last MP injection, respectively, and then allocated to the 2-, 4- and 8-week model groups(n=24 each). Rats in the control group(n=12) were not given any treatment. Histopathological analysis was performed and the concentration of tartrate-resistant acid phosphatase(TRAP) in plasma was determined. The activation of osteoclasts in the femoral head was assessed by TRAP staining. The expression of TLR4, MyD88, TRAF6 and NF-κB p65 that are involved in TLR4 signaling, and MCP-1 production were detected by using real-time PCR(RT-PCR) and Western blotting. The results showed that the osteonecrosis in the femoral head was clearly observed and the concentration of TRAP in the plasma was increased in the model rats. The femoral head tissues in MP-treated rats were positive for TRAP and the intensity of TRAP staining was greater in MP-treated rats than in control rats. As compared with the control group, the mRNA expression of TLR4 signaling-related factors was enhanced significantly at 4 and 8 weeks, and the protein levels of these factors increased significantly with time. It was concluded that MP could induce the femoral head osteonecrosis in rats, which was associated with osteoclast activation via the TLR4 signaling pathway. These findings suggest that TLR4 signaling pathway plays a pivotal role in the pathogenesis of steroid-induced osteonecrosis.
基金Basic Research Project of Science and Technology Offi ce of Sichuan Province, No. 04JY029-090-1
文摘AIM: To investigate the effect of Lactobacillus bulgaricus (LBG) on the Toll-like receptor 4 (TLR4) pathway and interleukin-8 (IL-8) production in SGC-7901 cells treated with Helicobacter pyloriSydney strain 1 lipopolysaccharide (HpyloriSS1-LPS). METHODS: SGC-7901 cells were treated with Hpylori SS1-LPS in the presence or absence of pretreatment for 1 h with viable LBG or supernatant recovered from LBG culture MRS broth (LBG-S). Cellular lysates were prepared for Western blot with anti-TLR4, anti-transforming growth factor β-activated kinase 1 (TAK1), anti-phospho-TAK1, anti-nuclear factor κB (NF-κB), anti-p38 mitogen-activated protein kinase (p38MAPK), and anti-phospho-p38MAPK antibodies. The amount of IL-8 in cell culture medium was measured by ELISA. RESULTS: H pylori SS1-LPS up-regulated the expression of TLR4, stimulated the phosphorylation of TAK1, subsequently enhanced the activation of NF- κB and the phosphorylation of p38MAPK in a time- dependent manner, leading to augmentation of IL-8 production in SGC-7901 cells. Viable LBG or LBG-S pretreatment attenuated the expression of TLR4, inhibited the phosphorylation of TAK1 and p38MAPK, prevented the activation of NF-κB, and consequently blocked IL-8 production.CONCLUSION: H pylori SS1-LPS induces IL-8 production through activating TLR4 signaling in SGC-7901 cells and viable LBG or LBG-S prevents H pyloriSS1-LPS-mediated IL-8 production via inhibition of the TLR4 pathway.
文摘This study investigated the effects of propofol on the mRNA expression of Toll-like receptor-4 (TLR4) in BV-2 cells during mimic ischemia-reperfusion (I/R) injury in vitro. BV-2 cells, a mouse microglia line, were cultured and divided into 4 groups at random: control group (group C), ischemia/reperfusion group (group I/R), low-dose propofol (25 μmol/L) intervention group (group PF25) and high-dose propofol (100 μmol/L) intervention group (group PF100). The mRNA expression of TLR4 and NF-κB was measured by means of RT-PCR. TNF-α levels in the supernatants of BV-2 cells were detected by ELISA. The results showed that the mRNA expression of TLR4 and NF-κB was significantly higher in groups I/R, PF25 and PF100 than in group C (P<0.01). And the TNF-α level in the supernatants was elevated in groups I/R, PF25 and PF100 as compared with that in group C (P<0.01). After pre-treatment with propofol, the mRNA expressions of TLR4 and NF-κB and the TNF-α level were significantly decreased in groups PF25 and PF100 in comparison to those in group I/R (P<0.01). And the decrease in those indicators was more significant in group PF100 than in group PF25 (P<0.01). It was concluded that propofol exerted brain-protecting effects during I/R injury by suppressing the mRNA expressions of TLR4 and NF-κB and deceasing the TNF-α level.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions and Graduate Scientific and Technological Innovation Projects of Nantong University,No.YKC12020Applied Research and Technology Plan of Nantong City,No.BK2013007
文摘The phosphatidylinositol 3 kinase(PI3K)/protein kinase B(AKT)signaling pathway is considered important for cell survival and has been shown to mediate various anti-apoptotic biological effects.This study explored the role of the Toll-like receptor 4(TLR4)-mediated PI3K/AKT-glycogen synthase kinase 3β(GSK-3β)signaling pathways in lipopolysaccharide-induced apoptosis in a primary culture of hippocampal neurons.Results demonstrated that the apoptotic ratio of hippocampal neurons stimulated by lipopolysaccharide was significantly higher compared with the control group.Both the expression of P-AKTSer473and P-GSK-3βSer9in hippocampal neurons stimulated by lipopolysaccharide decreased compared with the control,while the level of active Caspase-3 and the ratio of Bax/Bcl-2 were significantly increased.The level of active Caspase-3 and the ratio of Bax/Bcl-2 in hippocampal neurons treated with TLR4 antibody or the GSK-3βinhibitor,LiCl,decreased before intervention with lipopolysaccharide,but increased after treatment with the AKT inhibitor,LY294002.These findings suggest that the TLR4-PI3K/AKT-GSK3βsignaling pathway may be involved in lipopolysaccharide-induced apoptosis of hippocampal neurons.
基金supported in part by National Natural Science Foundation of China (30700684 and 30671814)Jiangsu Natural Science Foundation (BK2008221)the Key Project of Nanjing Medical University (09NJMUZ12)
文摘Objective:Inflammation induced by H.pylori colonization in the stomach is related to the development of gastric cancer and the genetic variations of the genes involved in the immune responses modify the host response to the infection. The aim of this study was to evaluate whether polymorphisms in the toll-like receptor 4 (TLR4) gene, a key regulator of both innate and adaptive immunity, were related to the susceptibility togastric cancer in a Chinese population. Methods: Two variations in the 5'-flanking region of TLR4 (rs1927914 T>C and rs10759932 T>C) were genotyped by using the PCR-restriction fragment length polymorphism (RFLP) assay in a case-control study of 1,053 incident gastric cancer cases and 1,100 cancer-free controls in a Chinese population. Results: Individuals carrying the C allele of rs10759932 had a significantly reduced risk of gastric cancer (adjusted OR=0.81; 95%CI=0.67-0.96), compared with the wild-type homozygote (TT), and the protective effect was not significantly different among subgroups stratified by age, sex, smoking, drinking and H.pylori infection status (P for heterogeneity >0.05). No significant association was observed between rs1927914 and gastric cancer risk in this study population. Conclusion: The T to C allele substitution of rs10759932 may play a protective role in gastric carcinogenesis in a Chinese population. Large studies with different ethnic populations are warranted to confirm these findings.
文摘AIM: To evaluate the role of genetic factors in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC), we investigated the single nucleotide poly- morphisms (SNPs) of NOD2/CARD15 (R702W, G908R and L1007fi nsC), and Toll-like receptor 4 (TLR4) genes (D299G and T399I) in a selected inflammatory bowel disease (IBD) population coming from Southern Italy. METHODS: Allele and genotype frequencies of NOD2/ CARD15 (R702W, G908R and L1007finsC) and TLR4 (D299G and T399I) SNPs were examined in 133 CD pa-tients, in 45 UC patients, and in 103 healthy controls. A genotype-phenotype correlation was performed. RESULTS: NOD2/CARD15 R702W mutation was sig-nificantly more frequent in CD (9.8%) than in controls (2.4%, P = 0.001) and in UC (2.3%, P = 0.03). No sig-nificant difference was found between UC patients and control group (P > 0.05). In CD and UC patients, no signifi cant association with G908R variant was found. L1007f insC SNP showed an association with CD (9.8%) compared with controls (2.9%, P = 0.002) and UC patients (2.3%, P = 0.01). Moreover, in CD patients, G908R and L1007finsC mutations were significantly associated with different phenotypes compared to CD wild-type patients. No association of IBD with the TLR4 SNPs was found in either cohort (allele frequencies: D299G-controls 3.9%, CD 3.7%, UC 3.4%, P > 0.05; T399I-controls 2.9%, CD 3.0%, UC 3.4%, P > 0.05). CONCLUSION: These findings confirm that, in our IBD patients selected from Southern Italy, the NOD2/ CARD15, but not TLR4 SNPs, are associated with in-creased risk of CD.
基金supported the grants from the Natural Science Foundation of Hubei province(No.2012FFB02325)the National Natural Science Foundation of China(No.81000159)
文摘Toll-like receptors(TLRs) are key components of the innate immune system which trigger antimicrobial host defense responses. This study aimed to investigate the impact of probiotics(Lactobacillus, Bifiidobacterium) on the expression of TLR4 and tumor necrosis factor-alpha(TNF-α) in the colon mucosa of rat experimental ulcerative colitis model induced by trinitrobenzene sulfonic acid(TNBS)/ethanol and immune complexes. The gross and histological changes of the colonic mucosa were observed and assessed by the means-standard deviation and independent samples t-test. The protein expression levels of TLR4 and TNF-α were detected by using immunohistochemistry and Western blotting, respectively. It was revealed that there was visible infiltration of inflammatory cells, formation of crypt abscess, and the reduction of goblet cells in the colon tissue of experimental models. As compared with the control group, the levels of TLR4 and TNF-α protein were significantly increased in the model group(P<0.01 for both). No significant difference was found in the expression of TLR4 and TNF-α between the two-week probiotics treatment group and the model group(P>0.05), whereas significant reductions were shown in rats which were treated with probiotics for four weeks as compared with the model group(P<0.01). There was no significant difference between two probiotics-treated groups. Our results implied that probiotics were likely to play a key role in protecting ulcerative colitis by reducing the inflammatory factor TNF-α expression through inhibiting the TLR4 expression in the colon tissue of experimental models.
文摘This study investigated the expression and immune effect of TLR4 in human trophoblast cells. The expression level of TLR4 mRNA in normal and LPS-stimulated human term trophoblast cells (1 mg/L LPS, 12 h) was detected by RT-PCR. In LPS-stimulated human term trophoblast cells of TLR4-blocked group and non-TLR4-blocked group, and normal term trophoblast cells of blank control group, apoptosis rate was measured by flow cytometry (FCM), and the level of TNF-α deter-mined by using enzyme linked immunosorbent assay (ELISA) respectively. RT-PCR results showed that the expression level of TLR4 mRNA in LPS-stimulated human trophoblast cells was signifi-cantly higher than that in normal cells (P<0.01). FCM revealed that there was significant difference in apoptosis rate of LPS-stimulated human term trophoblast cells between TLR4-blocked group and non-TLR4-blocked group (P<0.05), or between TLR4 antibody-blocked group and blank control group. ELISA indicated that the level of TNF-α in LPS-stimulated human trophoblast cells also had statistical differences between TLR4 antibody-blocked group and non-TLR4 antibody-blocked group (P<0.05). Our results suggest that TLR4 plays an important role in the immunological mechanism of apoptosis and secretion of TNF-α of human term trophoblast cells stimulated by LPS.
基金Supported by(partially)from the Instituto de Salud CarlosⅢ,Madrid,Spain,No.PI0900357cofinanced by Fondos FEDER(Fondo Europeo de Desarrollo Regional)+3 种基金“Una manera de hacer Europa”,European Union,and CERCA Programme,Generalitat de CatalunyaSilvia Vidal was supported by Fondo de Investigaciones Sanitarias(FIS)a participant in the Program for Stabilization of Investigators of the Direcciód’Estrategia i Coordinaciódel Departament de Salut,Generalitat de CatalunyaEdilmar Alvarado-Tapias is a recipient of a“Río Hortega”fellowship grant from the Instituto de Salud CarlosⅢ,No.CM16/00133
文摘AIM To assess the relationship between the presence of toll-like receptor 4(TLR4) polymorphisms and bacterial infections in cirrhotic patients with ascites. METHODS We prospectively included consecutive patients with cirrhosis and ascites hospitalized during a 6-year period. Patients with human immunodeficiency virus(HIV) infection or any other immunodeficiency, patients with advanced hepatocellular carcinoma(beyond Milan's criteria) or any other condition determining poor short-term prognosis, and patients with a permanent urinary catheter were excluded. The presence of D299 G and/or T399 I TLR4 polymorphisms was determined by sequencing and related to the incidence and probability of bacterial infections, other complications of cirrhosis, hepatocellular carcinoma, and mortality during follow-up. A multivariate analysis to identify predictive variables of mortality in the whole series was performed. RESULTS We included 258 patients: 28(10.8%) were carriers of D299G and/or T399I TLR4 polymorphisms(polymorphism group) and 230 patients were not(wildtype group). The probability of developing any bacterial infection at one-year follow-up was 78% in the polymorphism group and 69% in the wild-type group(P = 0.54). The one-year probability of presenting infections caused by gram-negative bacilli(51% vs 44%, P = 0.68), infections caused by gram-positive cocci(49% vs 40%, P = 0.53), and spontaneous bacterial peritonitis(29% vs 34%, respectively, P = 0.99) did not differ between the two groups. The oneyear probability of transplant-free survival was 55% in the polymorphism group and 66% in the wild-type group(P = 0.15). Multivariate analysis confirmed that age, Child-Pugh score, active alcohol intake, previous hepatic encephalopathy, hepatocellular carcinoma and serum creatinine were associated with a higher risk of death during follow-up. CONCLUSION Genetic polymorphisms D299 G and/or T399 I of TLR4 do not seem to play a relevant role in the predisposition of cirrhotic patients with ascites to bacterial infections.
基金Project supported by the National Natural Science Foundation of China (No. 30270571)Doctor Degree Point Foundation of Ministry of Education, China (No. 20020335080)
文摘Objective: To explore the effects of transforming growth factor β1(TGF-β1) on dendritic cells (DC). Methods: Murine bone marrow cells were cultured with GM-CSF and TGF-β1 to develop TGF-β1-treated DC (TGFβ-DC). Then they were stimulated by lipopolysaccharide (LPS). Their phenotypes were assessed by flow cytometry (FCM). The allogeneicstimulating capacity of DC was measured by mixed lymphocyte reaction (MLR) using BrdU ELISA method and IL-12p70 protein was detected by ELISA. The expression of Toll-like receptor 4 (TLR4) was analyzed by semi quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and FCM. Results: Compared to immature DC (imDC) cultured by GM-CSF alone, the TGFβ-DC express lower CD80, CD86, I-A^b and CD40. The TGFβ-DC were resistant to maturation with LPS. Maturation resistance was evident from a failure to up-regulate co-stimulatory molecules (CMs), to stimulate larger T cells proliferation and to enhance secretion of IL-12p70. We also found that TGF-β1 could down-regulate TLR4 expression on TGFβ-DC. Conclusion: TGFβ-DC are resistant to maturation stimulus (LPS) and might have some correlation with the down-modulation of TLR4 expression.
文摘The expression of Toll-like receptor 4 (TLR4) in neonatal cord blood mononuclear cells (MNCs) and serum TNF-α were investigated in order to explore the roles of TLR4 in the pathogenesis of preeclampsia.The study enrolled 27 patients suffering from preeclampsia (experimental group) and 21 normal pregnancy patients (control group).After MNCs were separated, the expression of TLR4 mRNA and protein was detected by using real-time quantitative PCR and Western blotting respectively, and the expression of TNF-α by using ELISA.The results showed the TLR4 mRNA level in cord blood MNCs (2-CT:0.07±0.17), TLR4 protein expression level (absorbance ratio:0.81%±0.15%) and TNF-α level (9.5±1.73 pg/mL) were all increased in experimental group as compared with control group with the differences being statistically significant (P<0.05).There was a positive correlation between the expression of TLR4 mRNA and TNF-α in both experimental group and control group (r=0.54 and 0.53, respectively, P<0.05).It was concluded that TLR4 expression in the experimental group of cord blood MNCs was increased and there was a positive correlation between the expression of TLR4 mRNA and TNF-α in both groups.TLR4-mediated release of inflammatory cytokines may be one of the important reasons leading to preeclampsia.
