MicroRNA-630 alleviates inflammatory reactions in rats with diabetic kidney disease by targeting toll-like receptor 4

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.

Fecal microbiota transplantation alleviates experimental colitis through the Toll-like receptor 4 signaling pathway

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.

Betaine inhibits Toll-like receptor 4 expression in rats with ethanol-induced liver injury

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.

Effects of ω-3 fatty acids on toll-like receptor 4 and nuclear factor-κB p56 in lungs of rats with severe acute pancreatitis

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.

Association between polymorphisms in the Toll-like receptor 4,CD14,and CARD15/NOD2and inflammatory bowel disease in the Greek population

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.

Lactobacilli inhibit interleukin-8 production induced by Helicobacter pylori lipopolysaccharide-activated Toll-like receptor 4

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 HpyloriSS1-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 pyloriSS1-LPS up-regulated the expression of TLR4, stimulated the phosphorylation of TAKI, 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 py/oriSS1-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.

Association of Toll-like receptor 4 Signaling Pathway with Steroid-induced Femoral Head Osteonecrosis in Rats

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 Toil-like receptor 4 （TLR4） signaling pathway in steroid-induced femoral head osteonecrosis in rats. Male Sprague-Dawley rats were injected intramus- cularly with 20 mg/kg methylprednisolone （MP） for 8 weeks, twice per week. The animals were sacri- ficed 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-Id3 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 concentra- tion 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 con- trol 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 signifi- cantly 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.

Clinical significance of NOD2/CARD15 and Toll-like receptor 4 gene single nucleotide polymorphisms in inflammatory bowel disease

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 polymorphisms （SNPs） of NOD2/CARD15 （R702W, Gg08R and L1007finsC）, 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, Gg08R and L1007finsC） and TLR4 （D299G and T399I） SNPs were examined in 133 CD patients, in 45 UC patients, and in 103 healthy controls. A genotype-phenotype correlation was performed. RESULTS： NOD2/CARD15 R702W mutation was significantly more frequent in CD （9.8%） than in controls （2.4%, P = 0.001） and in UC （2.3%, P = 0.03）. No significant difference was found between UC patients and control group （P 〉 0.05）. In CD and UC patients, no significant association with G908R variant was found. L1007finsC 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 increased risk of CD.

Impact of Probiotics on Toll-like Receptor 4 Expression in an Experimental Model of Ulcerative Colitis

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 （Lactoba- cillus, Bifiidobacterium） on the expression of TLR4 and tumor necrosis factor-alpha （TNF-α in the co- lon 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 pro- tein expression levels of TLR4 and TNF-α were detected by using immunohistochemistry and Westem 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 com- pared 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 sig- nificant 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.

Production of interleukin-1β related to mammalian target of rapamycin/Toll-like receptor 4 signaling pathway during Aspergillus fumigatus infection of the mouse cornea

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.

A 5'-flanking region polymorphism in toll-like receptor 4 is associated with gastric cancer in a Chinese population

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 to

Role of Toll-like receptor 4 in inflammatory reactions of hippocampal neurons

Lipopolysaccharide stimulates Toll-like receptor 4 on immune cells to produce immune mediators. Toll-like receptor 4 is also expressed by non-immune cells, which can be stimulated by lipopolysaccharide. However, whether Toll-like receptor 4 is expressed by primary cultured hippocampal neurons and its specific role in lipopolysaccharide-induced neuroinflammation is currently undefined, in this study, Toll-like receptor 4 antibody blocking was used to analyze the Toll-like receptor 4 signaling pathway and changes in inflammation of lipopolysaccharide stimulated hippocampal neurons. Immunofluorescence showed that Toll-like receptor 4 protein was mainly located in the membrane of hippocampal neurons. Quantitative reverse transcription-PCR and western blot assay showed that after stimulation of lipopolysaccharide, the mRNA and protein levels of Toll-like receptor 4 and the mRNA levels of interleukin-ll3 and tumor necrosis factor-（] were significantly increased. In addition, there was increased phosphorylation and degradation of kappa B a inhibitor in the cytosol and increased nuclear factor-KB p65 expression in the nuclei. Pretreatment with Toll-like receptor 4 antibody could almost completely block this increase. These experimental findings indicate that lipopolysaccharide participates in neuroinflammation by stimulating Toll-like receptor 4/nuclear factor-KB pathway in hippocampal neurons, which may be both ＂passive victims＂ and ＂activators＂ of neuroinflammation.

Toll-like receptor 4 as a possible therapeutic target for delayed brain injuries after aneurysmal subarachnoid hemorrhage

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.

Impact of Toll-like Receptor 4 Deficiency on Cerebrocardiac Syndrome

In order to investigate the role of Toll-like receptor 4 （TLR4） in cerebrocardiac syndrome （CCS）, the partial cerebral ischemia/reperfusion （I/R） models in mice with different TLR4 genotypes were established in the present study. TLR4 wild-type （C3H/HeN） and mutant （C3H/HeJ） mice of 6-8 weeks of age were divided into 4 groups at random： C3H/HeN sham group （n=10）, C3H/HeJ sham group （n=10）, C3H/HeN model group （n=10） and C3H/HeJ model group （n=10）. Partial cerebral I/R was caused by the middle cerebral artery occlusion （MCAO） to duplicate CCS models in mice. After the operation, the electrocardiogram （ECG）, the level of tumor necrosis factor-alpha （TNF-c0 in myocardial tissue and the cardiac pathological changes were observed in each group. It was shown that the brain infarct volume in C3H/HeN model group was larger than that in C3H/HeJ model group （P〈0.01）. The ST segment change and T wave inversion occurred frequently in model groups. Moreover, the TNF-ct level in C3H/HeN model group was higher than that in C3H/HeJ model group （P〈0.01）. The myocar- dial injury was aggravated in C3H/HeN group as compared with C3H/HeJ group. It was concluded that TLR4 was implicated in the development of CCS.

Expression of Toll-like Receptor 4 in Neonatal Cord Blood Mononuclear Cells in Patients with Preeclampsia

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.

TGF-β1 treated murine dendritic cells are maturation resistant and down-regulate Toll-like receptor 4 expression

Objective: To explore the effects of transforming growth factor (51 (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 allogeneic stimulating 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-Ab 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.

Role of Toll-like receptor 4 and Janus kinase and signal transducer and activator of transcription signal transduction pathway in sepsis-induced brain damage

The Janus kinase and signal transducer and activator of transcription （JAK/STAT） signal transduction pathway is involved in sepsis-induced functional damage to the heart, liver, kidney, and other organs. However, the cellular and molecular mechanisms underlying sepsis-induced brain damage remain elusive. In the present study, we found severe loss of neurons in the hippocampal CA1 region in rats with sepsis-induced brain damage following intraperitoneal injection of endotoxin, The expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 was significantly increased in brain tissues following lipopolysaccharide exposure. AG490 （JAK2 antagonist） and rapamycin （STAT3 antagonist） significantly reduced neuronal loss and suppressed the increased expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 in the hippocampal CA1 region in sepsis-induced brain damaged rats. Overall, these data suggest that blockade of the JAK/STAT signal transduction pathway is neuroprotective in sepsis-induced brain damage via the inhibition of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 exoression.

Overexpression of Toll-like receptor 4 contributes to the internalization and elimination of Escherichia coli in sheep by enhancing caveolae-dependent endocytosis

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.

Effect of remifentanil on toll-like receptor 4, NF-κB and IL-6 in rabbit myocardial ischemia/reperfusion model

Objective： To investigate whether remifentanil induced cardioprotecting effect is associated with expression of toll-like receptor 4 （TLR4）, nuclear factor rB （NF-r.B） and serum interleukin -6 （IL-6）. Methods： Fifty rabbits were randomly divided into 5 groups （n=10） according to the treatment： sham operation group （group A）, ischemla-reperfusion group （group B）, low-dose remifentanil group （group C）, mediate-dose remifentanil group （group D）, and high-dose remlfentanil group （group E） Myocardial TLR4 mRNA levels, NF-r.B protein expression and serum levels of IL-6 were observed in 120 min after reperfusion. Results： The myocardial expressions of TLR4 mRNA, NF-rd3 protein and IL-6 level in sera of groups B, C, D and E were elevated compared with group A. However, remifentanil significantly reduced the levels of TLR4 mRNA, NF- r.B protein expression and serum IL-6 in groups C, D and E compared with group B. There were remarkable differences between the groups （P〈O.O1）. Conclusion： Intravenous remifentanil has protective effect against rabbit myocardial ischemia/reperfusion injury. This effect may be associated with TLR4, NF-r.B expressions on myocytes and serum level of IL-6 in a dose-dependent manner

Toll-like receptor 4 polymorphisms to determine acute pancreatitis susceptibility and severity: A meta-analysis

AIM: To investigate the correlation of toll-like receptor 4 (TLR4) gene Asp299Gly and Thr399Ile polymorphisms and acute pancreatitis (AP) risk and severity.