title: Proinflammatory effects and molecular mechanisms of interleukin-17 in intestinal epithelial cell line HT-29.
abstract: OBJECTIVE
  To evaluate the proinflammatory effects and molecular mechanisms of interleukin (IL)-17 in intestinal epithelial cell line HT-29.
  
  
  METHODS
  HT-29 cells were cultured with IL-17, tumor necrosis factor (TNF)-α, or the combination of both IL-17 and TNF-α. Real-time PCR and Western blot were used to measure the gene expression levels of neutrophil chemokines CXCL1, CXCL2, CXCL5, CXCL6, IL-8 and TH-17 cell chemokine CCL20, the phosphorylation levels of p38 and TNF-α, and the expression level of IL-8, after using the p38 inhibitor in HT-29 cells. The stable Act1 knockdown HT-29 cell line was established to further test the phosphorylation changes of p38, after using IL-17 and TNF-α.
  
  
  RESULTS
  After HT-29 cells were cultured with IL-17 and TNF-α, the expression levels of neutrophil chemokines (CXCL1, CXCL2, CXCL5, CXCL6, IL-8) and Th17 chemokine (CCL20) significantly improved (24.96 ± 2.53, 28.47 ± 2.87, 38.08 ± 2.72, 33.47 ± 2.41, 31.7 ± 2.38, 44.37 ± 2.73, respectively), and the differences were all statistically significant (P < 0.01). Western blot results showed that IL-17 obviously enhanced the phosphorylation level of p38, which was induced by TNF-α. Compared with the control group, the expression level of IL-8 significantly declined (9.47 ± 1.36 vs 3.06 ± 0.67, P < 0.01) when TH-29 cells were cultured with IL-17 and TNF-α. p38 inhibition assay showed that the p38 pathway played an essential role in the inflammatory response induced by IL-17. p38 phosphorylation levels could not be changed after using IL-17 and TNF-α in the stable Act1 knockdown HT-29 cell line.
  
  
  CONCLUSIONS
  IL-17 significantly promoted the gene expression levels of TNF-α-induced neutrophil chemokines and Th17 cell chemokine. It is obvious that IL-17 and TNF-α have synergistic effects on p38.
authors.affiliation: Yi-Lin Wang, Ran Tao, Center for Organ Transplantation and Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Yi-Lin
authors.initials: YL
authors.lastname: Wang
authors.affiliation: Yi-Lin Wang, Ran Tao, Center for Organ Transplantation and Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Fang
authors.affiliation: Yi-Lin Wang, Ran Tao, Center for Organ Transplantation and Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Wang
authors.affiliation: Yi-Lin Wang, Ran Tao, Center for Organ Transplantation and Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Wei-Yan
authors.initials: WY
authors.lastname: Liu
authors.affiliation: Yi-Lin Wang, Ran Tao, Center for Organ Transplantation and Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Yun-Jiang
authors.initials: YJ
authors.lastname: Zheng
authors.affiliation: Yi-Lin Wang, Ran Tao, Center for Organ Transplantation and Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Xu-Bo
authors.initials: XB
authors.lastname: Wu
authors.affiliation: Yi-Lin Wang, Ran Tao, Center for Organ Transplantation and Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Tao
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D004847:Epithelial Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D005786:Gene Expression Regulation; D019073:HT29 Cells; D006801:Humans; D018836:Inflammation Mediators / Q000494:pharmacology*; D015212:Inflammatory Bowel Diseases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D020381:Interleukin-17 / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014162:Transfection; D047988:Tumor Necrosis Factor Receptor-Associated Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D018836:Inflammation Mediators; D020381:Interleukin-17; D047428:Protein Kinase Inhibitors; C414202:TRAF3IP2 protein, human; D047988:Tumor Necrosis Factor Receptor-Associated Peptides and Proteins; D014409:Tumor Necrosis Factor-alpha; D048051:p38 Mitogen-Activated Protein Kinases
keywords: HT-29; IL-17; Inflammatory bowel disease; TNF-α