1.Association Between Toll-Like Receptors/CD14 Gene Polymorphisms and Inflammatory Bowel Disease in Korean Population.
Eun Jung KIM ; Woo Chul CHUNG ; Kang Moon LEE ; Chang Nyol PAIK ; Sung Hoon JUNG ; Bo In LEE ; Hiun Suk CHAE ; Kyu Yong CHOI
Journal of Korean Medical Science 2012;27(1):72-77
The innate immune response in patients who develop inflammatory bowel disease (IBD) may be abnormal. However, the exact role of Toll-like receptors (TLRs) / CD14 gene in the pathogenesis of IBD has not been fully elucidated. We aimed to investigate the association between polymorphisms of TLR1, 2, 4, 6, and CD14 gene and susceptibility to IBD in Korean population. A total 144 patients of IBD (99 patients with ulcerative colitis, 45 patients with Crohn's disease) and 178 healthy controls were enrolled. Using a PCR-RFLP, we evaluated mutations of TLR1 (Arg80Thr), TLR2 (Arg753Gln and Arg677Trp), TLR4 (Asp299Gly and Thr399Ile), TLR6 (Ser249Pro) genes and the -159 C/T promoter polymorphism of CD14 gene. No TLR polymorphisms were detected in Korean subjects. T allele and TT genotype frequencies of CD14 gene were significantly higher in IBD patients than in healthy controls. In subgroup analysis, T allelic frequency was higher in pancolitis phenotype of ulcerative colitis. In Korean population, the promoter polymorphism at -159 C/T of the CD14 gene is positively associated with IBD, both ulcerative colitis and Crohn's disease.
Adult
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Aged
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Alleles
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Antigens, CD14/*genetics
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Asian Continental Ancestry Group/*genetics
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Colitis, Ulcerative/genetics
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Crohn Disease/genetics
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Female
;
Gene Frequency
;
Genetic Predisposition to Disease
;
Genotype
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Humans
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Inflammatory Bowel Diseases/*genetics
;
Male
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Middle Aged
;
Phenotype
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Polymorphism, Single Nucleotide
;
Promoter Regions, Genetic
;
Republic of Korea
;
Toll-Like Receptor 1/genetics
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Toll-Like Receptor 2/genetics
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Toll-Like Receptor 4/genetics
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Toll-Like Receptor 6/genetics
;
Toll-Like Receptors/*genetics
2.Effect of CD-14 and toll like receptors on the expression of interleukin-6 induced by lipopolysaccharides of Porphyromonas endodontalis.
Ge JIA ; Li-Hong QIU ; Ren LI ; You LÜ ; Ya-Qiong YU ; Ming ZHONG
Chinese Journal of Stomatology 2011;46(9):531-536
OBJECTIVETo evaluate the effect of cluster of differentiation 14 (CD-14) and Toll like receptors (TLR) on the expression of interleukin-6 (IL-6) mRNA induced by Porphyromonas endodontalis (Pe) lipopolysaccharides (LPS).
METHODSMC3T3-E1 cells were treated with 10 mg/L Pe-LPS for different hours, and the cells uninvolved by anything as the blank group. The expression of IL-6 was detected by reverse transcription polymerse chain reaction (RT-PCR) and enzyme-liked immunosorbent assay (ELISA). The expression of CD-14, TLR-2 and TLR-4 mRNA was observed at different time point (0 - 24 h) by RT-PCR. The protein of CD-14, TLR-2 and TLR-4 was analyzed with a flow cytometer. MC3T3-E1 cells were pretreated with anti-CD-14, anti-TLR-2 and anti-TLR-4 antibody for 1 h, and then cells were stimulated with 10 mg/L Pe-LPS for 6 h. The expression of IL-6 mRNA was examined by RT-PCR. Statistical analysis was performed using one-way ANOVA Dunnett-t test with SPSS 11.0 software package.
RESULTSThe IL-6 mRNA and proteins increased significantly after treatment with Pe-LPS. When MC3T3-E1 cells treated by Pe-LPS for 6 h, the expression of proteins soared from (11.696 ± 0.672) ng/L to (36.534 ± 0.574) ng/L (P < 0.01); In the control group, the CD-14 and TLR-4 mRNA are ambly-expression, and the ratios of CD-14 and TLR-4 positive cells were (39.038 ± 3.131)% and (11.438 ± 0.385)% respectively in MC3T3-E1. After treatment by Pe-LPS, the expression of CD-14 and TLR-4 mRNA increased significantly, and the ratios of CD-14 and TLR-4 positive cells markedly increased to (62.407 ± 1.800)% and (21.367 ± 2.271)%. TLR-2 expression did not change apparently after Pe-LPS treatment. The expression of IL-6 mRNA was partly inhibited by anti-CD-14 or anti-TLR-4 antibody, but not by TLR-2.
CONCLUSIONSPe-LPS can induce the expression of IL-6 in osteoblast MC3T3-E1 through CD-14 and TLR-4, but not TLR-2.
3T3 Cells ; Animals ; Antibodies ; immunology ; Interleukin-6 ; genetics ; metabolism ; Lipopolysaccharide Receptors ; genetics ; metabolism ; Lipopolysaccharides ; isolation & purification ; pharmacology ; Mice ; Porphyromonas endodontalis ; RNA, Messenger ; metabolism ; Toll-Like Receptor 2 ; genetics ; metabolism ; Toll-Like Receptor 4 ; genetics ; metabolism
3.Intragingival injection of Porphyromonas gingivalis-derived lipopolysaccharide induces a transient increase in gingival tumour necrosis factor-α, but not interleukin-6, in anaesthetised rats.
Hiroko TAGUCHI ; Yuri AONO ; Takayuki KAWATO ; Masatake ASANO ; Noriyoshi SHIMIZU ; Tadashi SAIGUSA
International Journal of Oral Science 2015;7(3):155-160
This study used in vivo microdialysis to examine the effects of intragingival application of lipopolysaccharide (LPS) derived from Porphyromonas gingivalis (Pg-LPS) on gingival tumour necrosis factor (TNF)-α and interleukin (IL)-6 levels in rats. A microdialysis probe with an injection needle attached to the surface of the dialysis membrane was implanted into the gingiva of the upper incisor. For comparison, the effects of LPS derived from Escherichia coli (Ec-LPS) on IL-6 and TNF-α levels were also analysed. Pg-LPS (1 μg/1 μL) or Ec-LPS (1 or 6 μg/1 μL) was applied by microsyringe, with gingival dialysates collected every hour. Enzyme-linked immunosorbent assay (ELISA) revealed that gingival dialysates contained approximately 389 pg·mL⁻¹ of IL-6 basally; basal TNF-α levels were lower than the detection limit of the ELISA. Pg-LPS failed to alter IL-6 levels but markedly increased TNF-α levels, which remained elevated for 2 h after treatment. Neither IL-6 nor TNF-α were affected by Ec-LPS. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that the gingiva expresses Toll-like receptor (TLR) 2 and TLR4 mRNA. Immunohistochemical examination showed that TLR2 and TLR4 are expressed by gingival epithelial cells. The present study provides in vivo evidence that locally applied Pg-LPS, but not Ec-LPS, into the gingiva transiently increases gingival TNF-α without affecting IL-6. The present results suggest that TLR2 but not TLR4 expressed on gingival epithelial cells may mediate the Pg-LPS-induced increase in gingival TNF-α in rats.
Animals
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Gingiva
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drug effects
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metabolism
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Interleukin-6
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metabolism
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Lipopolysaccharides
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administration & dosage
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Male
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Porphyromonas gingivalis
;
metabolism
;
RNA, Messenger
;
genetics
;
Rats
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Rats, Sprague-Dawley
;
Toll-Like Receptor 2
;
genetics
;
metabolism
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Toll-Like Receptor 4
;
genetics
;
metabolism
;
Tumor Necrosis Factor-alpha
;
metabolism
4.Establishment and application of TLR2 receptor-based cell screening model.
Ke LI ; Fang HUA ; Xiao-Xi LÜ ; Jiao-Jiao YU ; Zhuo-Wei HU
Acta Pharmaceutica Sinica 2013;48(5):694-699
TLR2 activity plays an important role in the pathogenesis of autoimmune diseases, tumor carcinogenesis and cardio-cerebrovascular diseases. To establish a TLR2 receptor-based cell screening model, NF-kappaB promoter-driven luciferase reporter plasmids were transfected into human embryonic kidney cells (HEK293) stably expressing human TLR2 and co-receptors CD14, TLR1 and TLR6. Single clones were then isolated and characterized. Using this screening system, a human TLR2-binding peptide C8 was obtained from the Ph.D.-7 Phage Display Peptide Library through biopanning and rapid analysis of selective interactive ligands (BRASIL). The binding characteristic of C8 with human TLR2 was evaluated by ELISA, flow cytometry and immunofluorescence. The NF-kappaB luciferase activity assay showed that C8 could activate the TLR2/TLR1 signaling pathway and induce the production of cytokines TNF-alpha and IL-6. In conclusion, the TLR2 receptor-based cell screening system is successfully established and a new TLR2-binding peptide is identified by using this system.
Bacteriophages
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Drug Evaluation, Preclinical
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Genes, Reporter
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HEK293 Cells
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Humans
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Interleukin-6
;
metabolism
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Lipopolysaccharide Receptors
;
metabolism
;
Luciferases
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genetics
;
metabolism
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Peptide Library
;
Peptides
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metabolism
;
pharmacology
;
Promoter Regions, Genetic
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Protein Binding
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Signal Transduction
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drug effects
;
Toll-Like Receptor 1
;
metabolism
;
Toll-Like Receptor 2
;
metabolism
;
Toll-Like Receptor 6
;
metabolism
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Transfection
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Tumor Necrosis Factor-alpha
;
metabolism
5.Effect of antimicrobial agents on the toll-like receptors and inflammatory cytokines in liver tissue of the alcohol-induced liver disease in rats with Vibrio vulnificus sepsis.
Zhong-qiu LU ; Meng-fang LI ; Qiao-meng QIU ; Huang LIANG ; Tie-li ZHOU ; Guang-liang HONG ; Bin WU
Chinese Medical Journal 2009;122(16):1910-1916
BACKGROUNDSepticemia and inflammation-mediated septic shock caused by Vibrio vulnificus (VV) is strongly associated with chronic liver disease. This study examined the effects of antimicrobial therapy on expression of hepatic toll-like receptors and inflammatory cytokines in rats with alcohol-induced liver disease complicated by VV sepsis.
METHODSMale Sprague-Dawley rats were assigned to the following treatment groups: normal control (N), alcoholic liver disease control (A), antimicrobial-treated alcoholic liver disease control (AA), alcoholic liver disease with VV sepsis (AV), and antimicrobial-treated alcoholic liver disease with VV sepsis (AVA). Alcohol-induced liver disease was observed in all groups except N. Expression of mRNAs encoding hepatic toll-like receptors 2 and 4, myeloid differentiation protein-2, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6 and IL-10 was determined by RT-PCR.
RESULTSmRNAs encoding toll-like receptors 2 and 4 and myeloid differentiation protein-2 were significantly up-regulated in group AV as compared to control groups at 2 - 24 hours of sepsis; peak expression occurred at 12 hours. These mRNAs were also up-regulated in group AVA but to lesser degrees than in group AV at comparable time post-infection. mRNAs encoding TNF-alpha, IL-1beta and IL-6 were significantly elevated in group AV as a function of infection. In group AVA as compared to AV, expression of TNF-alpha and IL-1beta mRNAs was lower at 12 - 24 hours post-infection and expression of IL-6 mRNA was lower at 24 hours post-infection. Compared with control groups, IL-10 mRNA expression in group AV was markedly higher at 12 - 24 hours of sepsis. Expression of IL-10 mRNA was lower in group AVA as compared to AV at 24 hours of sepsis.
CONCLUSIONSAntimicrobial therapy reduces expression of toll-like receptors and cytokines in rats with alcohol-induced liver disease complicated by VV sepsis. Monitoring hepatic toll-like receptor and cytokine expression during antibiotic therapy may be valuable for determining the course of VV sepsis in subjects with liver disease.
Adaptor Proteins, Signal Transducing ; genetics ; Animals ; Anti-Infective Agents ; therapeutic use ; Cytokines ; genetics ; Interleukin-10 ; genetics ; Interleukin-1beta ; genetics ; Interleukin-6 ; genetics ; Liver ; drug effects ; metabolism ; Liver Diseases, Alcoholic ; drug therapy ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Sepsis ; drug therapy ; genetics ; microbiology ; Toll-Like Receptor 2 ; genetics ; Toll-Like Receptor 4 ; genetics ; Toll-Like Receptors ; genetics ; Tumor Necrosis Factor-alpha ; genetics ; Vibrio Infections ; drug therapy ; Vibrio vulnificus ; physiology
6.Experimental study on the antagonistic activity of cationic multi-peptide mastoparan-1 against lipopolysaccharide.
Yi-bin GUO ; Jiang ZHENG ; Gen-fa LV ; Guo WEI ; Liang-xi WANG ; Guang-xia XIAO
Chinese Journal of Burns 2005;21(3):189-192
OBJECTIVETo explore the mechanism of cationic multi-peptide mastoparan-1 (MP-1) on the protection of mice from lipopolysaccharide (LPS) challenge.
METHODSThirty Kunming mice were divided randomly into MP-1, injury, protection groups with 10 mice in each group. The mice in MP-1 group were injected with 3 mg/kg MP-1 by tail vein, while those in injury group were injected with 20 mg/kg LPS by tail vein, and those in protection group 3 mg/kg MP-1 within 20 seconds after 20 mg/kg LPS injection were injected. The effects of MP-1 on the protection of mice from LPS challenge were observed. In vitro, the affinity of MP-1 and PMB to LPS was compared by biosensor and FAST fit construct and expressed as Kd. And the neutralizing activity of MP-1 and PMB in dose of 5, 10, 20, 40 micromol/L on LPS (2 microg/L) was detected by dynamic turbidimetric limulus test with LPS neutralizing 0 micromol/L MP-1 and PMB as control. The mRNA expression levels of TLR4, TNF-alpha and IL-6 in murine peritoneal macrophages (PM phi) after exposure to LPS (100 ng/ml) were assayed by RT-PCR.
RESULTSMP-1 could significantly protect mice from LPS challenging with protection rate of 90%. In vitro, MP-1 had a high affinity (Kd value: 484.0 nmol/L) and neutralizing ability with LPS, but it was lower than that of PMB (Kd value: 18.9 nmol/L). The neutralizing effect of 20 and 40 micromol/L MP-1 was obviously stronger than that in 0 micromol/L (P < 0.01). MP could obviously inhibit the expression of TLR4, TNF-alpha and IL-6 mRNA in LPS-stimulated murine PM phi.
CONCLUSIONMP-1 can evidently protect mice from lethal LPS challenge, and the mechanism might be related to the activity of MP-1 which binding and neutralizing LPS, blocking the combination LPS with its receptors. So the murine macrophage activation induced by LPS was inhibited.
Animals ; Interleukin-6 ; genetics ; metabolism ; Lipopolysaccharides ; antagonists & inhibitors ; Macrophages, Peritoneal ; drug effects ; metabolism ; Mice ; Mice, Inbred Strains ; Peptides ; pharmacology ; RNA, Messenger ; genetics ; Toll-Like Receptor 4 ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; genetics ; metabolism ; Wasp Venoms ; pharmacology
7.miR-18a ameliorates inflammation and tissue injury in a mouse model of allergic rhinitis via blocking TLR4/NF-κB pathway.
Jun YANG ; Qingyun LI ; Lu WANG ; Hui XIE
Chinese Journal of Cellular and Molecular Immunology 2023;39(8):680-685
Objective To investigate the role of microRNA-18a (miR-18a) in the pathogenesis of allergic rhinitis in mice. Methods Twenty-two BALB/c mice were randomly divided into a blank group, a model group and a miR-18a group. Mice in the model group and the miR-18a group were injected intraperitoneally with obumin (OVA) suspension to prepare allergic rhinitis models, and mice in the miR-18a group were simultaneously given lentiviral vector plasmid for overexpression of miR-18a. Allergy symptoms were evaluated by the behavioral score and HE staining. The plasma levels of interleukin-1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α) were measured by ELISA. The distribution of CD45+ cells in nasal mucosa was measured by immunofluorescence histochemistry, and CD45+ cells in nasal lavage fluid were measured by flow cytometry. The mRNA expression levels of IL-1β, IL-6 and TNF-α in nasal mucosa tissues were measured by fluorescence quantitative PCR, and the protein expressions of Toll like receptor 4 (TLR4), nuclear factor κB p65 (NF-κB p65), inhibitor of NF-κB α (IκBα) and phosphorylated IκBα (p-IκBα) in nasal mucosa were measured by Western blot analysis. Results Compared with the blank group, the plasma levels of IL-1β, IL-6, and TNF-α in the model group increased significantly. The number of CD45+ cells in both nasal mucosa tissue and nasal irrigation fluid increased, and the mRNA levels of IL-1β, IL-6 and TNF-α and the protein expression levels of TLR4, NF-κB p65 and p-IκBα in nasal mucosa increased. Compared with the model group, the plasma levels of IL-1β, IL-6 and TNF-α in the miR-18a group decreased significantly. The number of CD45+ cells in both nasal mucosa tissue and nasal lavage fluid decreased, and the mRNA levels of IL-1β, IL-6 and TNF-α and the exprotein expression levels of TLR4, NF-κB p65 and p-IκBα in nasal mucosa decreased. Conclusion miR-18a can inhibit the occurrence and development of allergic rhinitis, and its molecular mechanism is related to the inhibition of TLR4/NF-κB pathway activation.
Animals
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Mice
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Disease Models, Animal
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Inflammation
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Interleukin-6/genetics*
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MicroRNAs/genetics*
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NF-kappa B/metabolism*
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NF-KappaB Inhibitor alpha
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Rhinitis, Allergic
;
RNA, Messenger
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Toll-Like Receptor 4/metabolism*
;
Tumor Necrosis Factor-alpha/genetics*
8.Role of Toll-like receptor 4 and human defensin 5 in primary endocervical epithelial cells.
Chinese Medical Journal 2010;123(13):1762-1767
BACKGROUNDEndocervical epithelial cells play early roles in the defense of upper female genital tract to pathogens. Toll-like receptors (TLRs) and human defensins (HD) have recently been identified as fundamental components of the innate immune responses to bacterial pathogens. We aimed to use in vitro model of human primary endocervical epithelial cells (HPECs) to investigate their roles in innate immune response of the endocervix.
METHODSTLR4 expression and distribution in HPECs and endocervix were investigated by immunofluorescence (IF). Cultured HPECs were divided into lipopolysaccharide (LPS) group which were treated by LPS for 0, 24 and 48 hours, and control group without treatment. At each time point, the levels of HD5, IL-6 and TNF-alpha in supernants were determined by ELISA. TLR4 and HD5 expressions of cells were detected by Western blotting simultaneously. HD5 expression pattern was also compared between the HeLa cell line and HPECs.
RESULTSEndocervix tissue surface and HPECs expressed TLR4. After incubated with LPS, HPECs expressed significantly higher levels of TLR4 than control group, especially after 24 hours (P < 0.01), however decreased after 48 hours with a similar level of TLR4 expression compared with control group. LPS could upregulate the secretion of HD5, IL-6 and TNF-alpha in a time-dependent manner (24 hours: P < 0.05; 48 hours: P < 0.01, compared with control group). Intracellular HD5 expression levels decreased over time. HD5 expression patterns in HPECs were different from HeLa cell line.
CONCLUSIONSTo respond to LPS stimulation, HPECs may function in the mucosal immune defense through TLR4 activation and HD5 secretion. HPEC is considered a significant model for immunological study.
Blotting, Western ; Cells, Cultured ; Cervix Uteri ; cytology ; Enzyme-Linked Immunospot Assay ; Epithelial Cells ; metabolism ; Female ; Fluorescent Antibody Technique ; HeLa Cells ; Humans ; Interleukin-6 ; metabolism ; Toll-Like Receptor 4 ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism ; alpha-Defensins ; genetics ; metabolism
9.Activity of Codonopsis canescens against rheumatoid arthritis based on TLRs/MAPKs/NF-κB signaling pathways and its mechanism.
Yu-Jie WANG ; Xiao-Yu ZHONG ; Xin-Hong WANG ; Yuan-Han ZHONG ; Lin LIU ; Fang-Yuan LIU ; Jin-Xiang ZENG ; Ji-Xiao ZHU ; Xiao-Lang DU ; Min LI ; Gang REN ; Guo-Yue ZHONG ; Xiao-Min WANG
China Journal of Chinese Materia Medica 2022;47(22):6164-6174
This paper aims to explore the activity of Codonopsis canescens extract against rheumatoid arthritis(RA) based on the Toll-like receptors(TLRs)/mitogen-activated protein kinases(MAPKs)/nuclear factor kappa B(NF-κB) signaling pathways and its mechanism. The ultra-performance liquid chromatography-quadrupole time-of-flight/mass spectrometry(UPLC-Q-TOF-MS) was used to identify the components of C. canescens extract. Forty-eight male SD rats were randomly divided into six groups, namely the normal group, the model group, the methotrexate(MTX) tablet group, and the low, medium, and high-dose C. canescens extract(ZDS-L, ZDS-M, and ZDS-H) groups, with 8 rats in each group. The model of collagen-induced arthritis in rats was induced by injection of bovine type Ⅱ collagen emulsion. MTX(2.5 mg·kg~(-1)), ZDS-L, ZDS-M, and ZDS-H(0.3 g·kg~(-1), 0.6 g·kg~(-1), and 1.2 g·kg~(-1)) were administrated by gavage. Rats in the normal group and the model group received distilled water. MTX was given once every three days for 28 days, and the rest medicines were given once daily for 28 days. Body weight, degree of foot swelling, arthritis index, immune organ index, synovial histopathological changes, and serum levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), and interleukin-6(IL-6) were observed. Protein expressions of TLR2, TLR4, NF-κB p65, p38 MAPK, and p-p38 MAPK in rats were determined by Western blot. Thirty-four main components were identified by UPLC-Q-TOF-MS, including 15 flavonoids, 7 phenylpropanoids, 4 terpenoids, 4 organic acids, 2 esters, and 2 polyalkynes. As compared with the normal group, the body weight of the model group was significantly decreased(P<0.01), and foot swelling(P<0.05, P<0.01), arthritis index(P<0.01), and the immune organ index(P<0.01) were significantly increased. The synovial histopathological injury was obviously observed in the model group. The serum levels of inflammatory factors TNF-α, IL-1β, and IL-6 were significantly increased(P<0.01), and the protein expression levels of TLR2, TLR4, NF-κB p65, p-p38 MAPK/p38 MAPK in the synovial tissue were significantly increased(P<0.01) in the model group. As compared with the model group, the body weights of the ZDS dose groups were increased(P<0.01), and the degree of foot swelling(P<0.01) and the arthritis index were decreased(P<0.05, P<0.01). The immune organ index was decreased(P<0.01) in the ZDS dose groups, and the synovial tissue hyperplasia and inflammatory cell infiltration were alleviated. The serum levels of TNF-α, IL-1β, and IL-6 were significantly decreased(P<0.05, P<0.01), and the protein expression levels of TLR2, TLR4, NF-κB p65, p-p38 MAPK/p38 MAPK were decreased(P<0.05, P<0.01) in the ZDS dose groups. C. canescens extract containing apigenin, tricin, chlorogenic acid, aesculin, ferulic acid, caffeic acid, and oleanolic acid has a good anti-RA effect, and the mechanism may be related to the inhibition of TLRs/MAPKs/NF-κB signaling pathways.
Animals
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Cattle
;
Male
;
Rats
;
Arthritis, Experimental/drug therapy*
;
Arthritis, Rheumatoid/drug therapy*
;
Body Weight
;
Codonopsis/chemistry*
;
Interleukin-6/blood*
;
NF-kappa B/genetics*
;
p38 Mitogen-Activated Protein Kinases/metabolism*
;
Plant Extracts/therapeutic use*
;
Rats, Sprague-Dawley
;
Signal Transduction
;
Toll-Like Receptor 2/metabolism*
;
Toll-Like Receptor 4/metabolism*
;
Tumor Necrosis Factor-alpha/pharmacology*
10.Effect of lipoxin A4 on the expression of Toll-like receptor 4 and TNF receptor-associated factor 6 in the liver of obese rats with sepsis.
Wei-Wei JIANG ; Li-Li GAO ; Ming WU ; Tong ZHAO ; Dong-Ling SHEN
Chinese Journal of Contemporary Pediatrics 2018;20(7):578-584
OBJECTIVETo study the protective effect of lipoxin A4 (LXA4) against sepsis induced by lipopolysaccharide (LPS) in rats with obesity and its effect on the expression of Toll-like receptor 4 (TLR4) and TNF receptor-associated factor 6 (TRAF6) in the liver.
METHODSA total of 60 male Sprague-Dawley rats aged three weeks were randomly divided into a normal group and an obesity group, with 30 rats in each group. A rat model of obesity was established by high-fat diet. Each of the two groups was further randomly divided into control group, sepsis group, and LXA4 group, and 8 rats were selected from each group. The rats in the control, sepsis, and LXA4 groups were treated with intraperitoneal injection of normal saline, LPS, and LXA4+LPS respectively. Twelve hours later, blood samples were collected from the heart and liver tissue samples were also collected. ELISA was used to measure the serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Western blot was used to measure the protein expression of TLR4 and TRAF6 in liver tissue. Quantitative real-time PCR was used to measure the mRNA expression of TLR4 and TRAF6.
RESULTSAfter being fed with high-fat diet for 6 weeks, the obesity group had significantly higher average weight and Lee's index than the normal group (P<0.05). Compared with the normal group, the obesity group had significant increases in the serum levels of IL-6 and TNF-α (P<0.05). In the normal group or the obesity group, the sepsis subgroup had significant increases in the serum levels of IL-6 and TNF-α compared with the control subgroup (P<0.05), while the LXA4 subgroup had significant reductions in the two indices compared with the sepsis subgroup (P<0.05). Compared with the normal group, the obesity group had significant increases in the protein and mRNA expression of TLR4 and TRAF6 (P<0.05). In the normal group or the obesity group, the sepsis subgroup had significant increases in the protein and mRNA expression of TLR4 and TRAF6 compared with the control subgroup (P<0.05). Compared with the sepsis subgroup, the LXA4 subgroup had significant reductions in the protein and mRNA expression of TLR4 and TRAF6 (P<0.05).
CONCLUSIONSLXA4 can reduce the serum levels of IL-6 and TNF-α and alleviate inflammatory response. LXA4 can inhibit the expression of TLR4 and TRAF6 in the liver of septic rats, possibly by inhibiting the TLR4 signaling pathway.
Animals ; Humans ; Interleukin-6 ; genetics ; metabolism ; Lipoxins ; administration & dosage ; Liver ; drug effects ; metabolism ; Male ; Obesity ; complications ; drug therapy ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Sepsis ; complications ; drug therapy ; genetics ; metabolism ; Signal Transduction ; drug effects ; TNF Receptor-Associated Factor 6 ; genetics ; metabolism ; Toll-Like Receptor 4 ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; genetics ; metabolism