Interleukin-8 (IL-8), which is a member of C-X-C chemokine subfamily, is an important activator and chemoattractant for neutrophils and has been implicated in a variety of inflammatory diseases. Numerous reports show that various cells express IL-8 mRNA and produce IL-8 protein rapidly, including monocytes, T lymphocytes, neutrophils, fibroblasts, endothelial cells and epithelial cells. The human IL-8 gene has a length of 5191 bp and contains four exons separated by three introns. It maps to human chromosome 4q12-q21. The mRNA consists of a 101 bases 5' untranslated region, an open reading frame of 297 bases, and a long 3' untranslated region of 1.2 kb. The 5' flanking region of the IL-8 gene contains potential binding sites for several nuclear factors including activated protein-1 (AP-1), activated protein-2 (AP-2), nuclear factor-gene binding (NF-kappa B), nuclear factor-interleukin-6 (NF-IL-6, also calls CAAT/enhancer-binding proteins, C/EBP), IFN regulatory factor-1 (IRF-1), hepatocyte nuclear factor-1 (HNF-1), and so on. IL-8 gene expression is regulated initially at the level of gene transcription. The rapid induction of IL-8 gene expression is likely mediated by latent transcription factors that bind the IL-8 promoter. AP-1 and NF-IL-6 physically interact with NF-kappa B, and functional cooperativity among these factors appears to be critical for optimal IL-8 promoter activity in different cell types. The IL-8 receptor (IL-8R) is a dimeric glycoprotein consisting of a 59 KDa and a 67 KDa subunit. It has been given the name CDw128. It is expressed in many different cell types including those not responding to IL-8. The receptor density is approximately 20,000/cell in neutrophils, 1,040/cell in monocytes, and 300/cell in T-lymphocytes. The IL-8R is a member of the family of G-protein-coupled receptors. There are at least two different IL-8 receptor types (CXCR1 and CXCR2). The activities of IL-8 are not species-specific. IL-8 affects the adhesion of neutrophils to the endothelium and induces the transendothelial migration of neutrophils. IL-8 also exhibits in vitro chemotactic activities against of T-lymphocytes and basophils. IL-8 gene expression can be regulated by fluid shear stress, which may play an important role in the genesis and development of both inflammation and arterosclerosis.
Gene Expression Regulation ; Interleukin-8 ; chemistry ; genetics ; physiology ; Receptors, Interleukin

Objective To investigate the relationship between interleukin-1β (IL-1β) and miR-185-5p in the process of joint injury in acute gouty arthritis (AGA). Methods The serum miR-185-5p levels of 89 AGA patients and 91 healthy volunteers were detected by real-time quantitative PCR. The correlation between miR-185-5p expression level and VAS score or IL-1β expression level was evaluated by Pearson correlation coefficient method. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of miR-185-5p in AGA. THP-1 cells were induced by sodium urate (MSU) to construct an in vitro acute gouty inflammatory cell model. After the expression level of miR-185-5p in THP-1 cells was upregulated or downregulated by transfection of miR-185-5p mimics or inhibitors in vitro, inflammatory cytokines of THP-1 cells, such as IL-1β, IL-8 and tumor necrosis factor α (TNF-α), were detected by ELISA. The luciferase reporter gene assay was used to determine the interaction between miR-185-5p and the 3'-UTR of IL-1β. Results Compared with the healthy control group, the expression level of serum miR-185-5p in AGA patients was significantly reduced. The level of serum miR-185-5p was negatively correlated with VAS score and IL-1β expression level. The area under the curve (AUC) was 0.905, the sensitivity was 80.17% and the specificity was 83.52%. Down-regulation of miR-185-5p significantly promoted the expression of IL-1β, IL-8 and tumor necrosis factor (TNF-α), while overexpression of miR-185-5p showed the opposite results. Luciferase reporter gene assay showed that IL-1β was the target gene of miR-185-5p, and miR-185-5p negatively regulated the expression of IL-1β. Conclusion miR-185-5p alleviates the inflammatory response in AGA by inhibiting IL-1β.
Humans ; 3' Untranslated Regions ; Arthritis, Gouty/genetics* ; Interleukin-1beta/genetics* ; Interleukin-8 ; Luciferases ; MicroRNAs/genetics* ; Tumor Necrosis Factor-alpha

OBJECTIVETo evaluate the relationship between IL8-251 gene polymorphisms and gastric cancer.

METHODSLiteratures were reviewed and selected based on the criteria for inclusion. The Meta-analysis software, REVMAN 4.2, was applied to check the heterogeneity across the studies and calculating the pooled OR.

RESULTSTotal of 2114 cases and 2505 controls from 8 studies for IL8-251 were included. The chi(2) value was 21.48 (P = 0.003), and the pooled OR of (AA + AT) vs. TT was 1.12 (95% CI 0.90 - 1.40). Large heterogeneity was found among the studies. After the sensitivity analysis, the pooled OR of (AA + AT) vs. TT 1.21 (95% CI 1.06 - 1.39).

CONCLUSIONIL8-251-A allele might be associated with higher risk of developing gastric cancer.

Alleles ; Genetic Predisposition to Disease ; Genotype ; Humans ; Interleukin-8 ; genetics ; Polymorphism, Genetic ; Stomach Neoplasms ; genetics

Interleukin 8 (IL8) is an important chemokine that elicits host immune response against tuberculosis (TB). However, whether there is an association between IL8 gene polymorphism and TB susceptibility in the Chinese population is unknown. IL8 gene was amplified and sequenced to search for nucleotide polymorphisms among the Chinese population. Four single nucleotide polymorphisms (SNPs) were identified, selected, and analyzed in a cohort of 438 patients with TB and 536 healthy controls. Allelic, genotypic, and haplotypic analysis demonstrated that the distribution of the four IL8 SNPs between patients with TB and healthy controls was not significantly different (P>0.05). The four IL8 SNPs detected in this study were not associated with TB susceptibility in the Chinese population. Secretion of IL8 by peripheral blood cells was greatly stimulated upon exposure to Mycobacterium tuberculosis whole cell extract, but such enhanced secretion was not associated with the IL8 rs4073 alleles.
Asian Continental Ancestry Group ; genetics ; China ; Genetic Predisposition to Disease ; Humans ; Interleukin-8 ; genetics ; Polymorphism, Single Nucleotide ; Tuberculosis ; genetics

Objective To explore the aptamer specific binding blood group antigen-binding adhesin (BabA) of Helicobacter pylori (H.pylori) for blocking of H.pylori adhering host cell. Methods H.pylori strain was cultured and its genome was extracted as templates to amplify the BabA gene by PCR with designed primers. The BabA gene obtained was cloned and constructed into prokaryotic expression plasmid, which was induced by isopropyl beta-D-galactoside (IPTG) and purified as target. The single stranded DNA (ssDNA) aptamers that specifically bind to BabA were screened by SELEX. Enzyme-linked oligonucleotide assay (ELONA) was used to detect and evaluate the characteristics of candidate aptamers. The blocking effect of ssDNA aptamers on H.pylori adhesion was subsequently verified by flow cytometry and colony counting at the cell level in vitro and in mouse model of infection, respectively. Meanwhile, the levels of cytokines, interleukin 6 (IL-6), IL-8, tumor necrosis factor α (TNF-α), IL-10 and IL-4 in the homogenate of mouse gastric mucosa cells were detected by ELISA. Results The genome of H.pylori ATCC 43504 strains was extracted and the recombinant plasmid pET32a-BabA was constructed. After induction and purification, the relative molecular mass (M_r) of the recombinant BabA protein was about 39 000. The amino acid sequence of recombinent protein was consistent with BabA protein by peptide mass fingerprint (PMF). Five candidate aptamers were selected to bind to the above recombinent BabA protein by SELEX. The aptamers A10, A30 and A42 identified the same site, while A3, A16 and the above three aptamers identified different sites respectively. The aptamer significantly blocked the adhesion of H.pylori in vitro. Animal model experiments showed that the aptamers can block the colonization of H.pylori in gastric mucosa by intragastric injection and reduce the inflammatory response. The levels of IL-4, IL-6, IL-8 and TNF-α in gastric mucosal homogenates in the model group with aptamer treatment were lower than that of model group without treatment. Conclusion Aptamers can reduce the colonization of H.pylori in gastric mucosa via binding BabA to block the adhesion between H.pylori and gastric mucosal epithelial cells.
Animals ; Mice ; Helicobacter pylori/genetics* ; Interleukin-4 ; Interleukin-6 ; Interleukin-8 ; Tumor Necrosis Factor-alpha ; Stomach ; Oligonucleotides ; Adhesins, Bacterial/genetics* ; Blood Group Antigens

Interleukin-8 is CXC chemokine that is initially discovered using chemotaxis and the activation of neutrophils and induces the migration and proliferation of smooth muscle cells. Interleukin-8 is a potent angiogenic factor that may play a role in atherosclerosis. To establish the temporal correlation between IL-8 expression and plaque development, we examined the expression during atherosclerosis of hyperlipemia rabbits using immunohistochemistry, ELISA, in situ hybridization. By location of immunohistochemistry, the expression of IL-8 protein increased obviously in intima of hyperlipemia rabbits at 8 and 12 week. Quantitative analysis of the expression of IL-8 Immunohistochemistry indicated that positive area of AS model was 4.48 times and 8.76 times that of control group at 8 and 12 week. The valuation of IOD of AS model was 4.16 times and 4.36 times that of control group at 8 and 12 week. By specific ELISA, the ratio of the IL-8 protein to total protein of AS model was 1.84 times and 2.06 times that of control group at 8 and 12 week. By location of in situ hybridization, positive location was strong in intima of hyperlipemia rabbits at 8 week. We observed the dynamic alteration of interleukin-8 protein and gene expression in atherosclerotic lesions of hyperlipemia rabbits with establishing model. Interleukin-8 protein and gene expression was up-regulation in the development of fatty streaks in hyperlipemia rabbit.
Animals ; Aorta ; metabolism ; Atherosclerosis ; etiology ; metabolism ; Hyperlipidemias ; complications ; Interleukin-8 ; biosynthesis ; genetics ; Male ; RNA, Messenger ; biosynthesis ; genetics ; Rabbits

Interleukin-8 (IL-8) is an important activator and chemoattratant of neutrophils and has been implicated in airway inflammatory diseases. To explore the new gene therapeutic strategies for airway inflammation, plasmid expressing dominant negative myeloid differentiation protein (MyD88 DN) was constructed and transfected into human airway epithelial cell lines A549 and SPC-A-I. The cells were challenged with M. tuberculosis, P. aeruginosa or K. pneumoniae and the release of IL-8 was measured using ELISA. The results showed that the supernatants of M. tuberculosis and R. aeruginosa enhanced IL-8 release from the epithelial cells; and transfection of MyD88 DN diminished this effect. MyD88 DN also reduced IL-8 release from cells induced by live bacteria of P. aeruginosa or K. pneumoniae. These data suggest that MyD88 could be used as a target gene in the gene therapy of airway inflammation.
Cells, Cultured ; Epithelial Cells ; microbiology ; secretion ; Humans ; Interleukin-8 ; secretion ; Mycobacterium tuberculosis ; Myeloid Differentiation Factor 88 ; genetics ; Pseudomonas aeruginosa ; Transfection

OBJECTIVE: To investigate the effect of silencing CD46 and desmoglein 2 (DSG2) in host A549 cells on the entry of human adenovirus type 3 (HAdV-3) and type 7 (HAdV-7) and host cell secretion of inflammatory cytokines. METHODS: RNA interference technique was use to silence the expression of CD46 or DSG2 in human epithelial alveolar A549 cells as the host cells of HAdV-3 or HAdV-7. The binding of the viruses with CD46 and DSG2 were observed with immunofluorescence staining at 0.5 and 1 h after viral infection. The viral load in the host cells was determined with qRT-PCR, and IL-8 secretion level was measured using ELISA. RESULTS: In infected A549 cells, immunofluorescent staining revealed colocalization of HAdV-3 and HAdV-37 with their receptors CD46 and DSG2 at 0.5 h and 2 h after infection, and the copy number of the viruses increased progressively after the infection in a time-dependent manner. In A549 cells with CD46 silencing, the virus titers were significantly lower at 2, 6, 12 and 24 h postinfection in comparison with the cells without gene silencing; the virus titers were also significantly decreased in the cells with DSG2 silencing. The secretion level of IL-8 increased significantly in A549 cells without siRNA transfection following infection with HAdV-3 and HAdV-7 (P < 0.0001), but decreased significantly in cells with CD46 and DSG2 silencing (P < 0.0001). CONCLUSION HAdV-3 and HAdV-7 enter host cells by binding to their receptors CD46 and DSG2, and virus titer and cytokines release increase with infection time. Silencing CD46 and DSG2 can inhibit virus entry and cytokine IL-8 production in host cells.
A549 Cells ; Adenoviruses, Human/metabolism* ; Desmoglein 2/metabolism* ; Humans ; Interleukin-8 ; Membrane Cofactor Protein/genetics* ; RNA, Small Interfering

BACKGROUND/AIMS: Saccharomyces boulardii (S. boulardii) has been reported to be beneficial in the treatment of inflammatory bowel disease, however, little is known about its mechanism of action. Peroxisome proliferator- activated receptor-gamma (PPAR-gamma) is recently found to regulate inflammation in intestinal epithelial cells. We hypothesized that the anti-inflammatory effects of S. boulardii are mediated, in part, through PPAR-gamma. To test this hypothesis, we examined the ability of S. boulardii to modulate the expression of PPAR-gamma in human colon cells. METHODS: Effects of S. boulardii on survival and proliferation of HT-29 human colon cells were assessed by MTT and [3H]thymidine incorporation assays. PPAR-gamma expression was assessed by Western blot and RT-PCR. Induction of interleukin-8 (IL-8) expression by tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), or lipopolysaccharide (LPS) was assessed by RT-PCR. RESULTS: S. boulardii did not affect viability and proliferation of HT-29 cells. S. boulardii up-regulated PPAR-gamma expression at both mRNA and protein levels. Pretreatment of HT-29 cells with S. boulardii blocked PPAR-gamma down-regulation by TNF-alpha, IL-1beta, or LPS, whereas it ameliorated IL-8 response to these proinflammatory factors. CONCLUSIONS: S. boulardii stimulates PPAR-gamma expression and reduces response of human colon cells to proinflammatory cytokines.
Cell Proliferation ; Colon/*metabolism ; *Gene Expression ; HT29 Cells ; Humans ; Interleukin-1/metabolism ; Interleukin-8/metabolism ; Lipopolysaccharides/pharmacology ; PPAR gamma/genetics/*metabolism ; Saccharomyces/*physiology

OBJECTIVETo investigate the expression of myeloid differentiation protein-2 (MD-2) in the human endothelial cells and its role in lipopolysaccharide (LPS)-induced NF-kappaB activation in endothelial cells.

METHODSIn vitro cultured human umbilical vein endothelial cells (HUVEC) were employed in the study. The expression of MD-2 mRNA and protein, and the effect of LPS on the expression of its mRNA and protein were assessed with RT-PCR and Western blotting. The role of MD-2 in LPS-induced NF-kappaB activation and IL-8 production were investigated with gene transfection of mutant MD-2 cDNA (0.5, 1.0, 2.0 microg), pEF-BOS vacant vector (2.0 microg) and MD-2 plasmid (2.0 microg) into HUVEC, respectively.

RESULTSThere was MD-2 mRNA and protein expression in HUVECs before LPS stimulation, and it could be obviously upregulated by LPS in time and dose-dependent manner (MD-2 protein absorbency was 25 196 +/- 1 723 without LPS stimulation, which was obviously lower than that stimulated with 0.01 mg/L LPS (58 817 +/- 3 241, P < 0.01) for 6 hours. Transfection of mutant MD-2 cDNA could remarkably inhibit LPS-induced NF-kappaB activation and IL-8 production in endothelial cells.

CONCLUSIONMD-2 might play an important role in the LPS-induced NF-kappaB activation in HUVECs.

Cell Differentiation ; Cells, Cultured ; Endothelial Cells ; metabolism ; Humans ; Interleukin-6 ; genetics ; Interleukin-8 ; metabolism ; Lipopolysaccharides ; pharmacology ; NF-kappa B ; metabolism ; Umbilical Veins ; cytology