Research Report
Copyright ©2014 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 21, 2014; 20(47): 17924-17931
Published online Dec 21, 2014. doi: 10.3748/wjg.v20.i47.17924
Proinflammatory effects and molecular mechanisms of interleukin-17 in intestinal epithelial cell line HT-29
Yi-Lin Wang, Meng Fang, Xiao-Ming Wang, Wei-Yan Liu, Yun-Jiang Zheng, Xu-Bo Wu, Ran Tao
Yi-Lin Wang, Ran Tao, Center for Organ Transplantation and Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
Meng Fang, Department of Anesthesia, The 88th Hospital of PLA, Tai’an 271000, Shandong Province, China
Xiao-Ming Wang, Department of Hepatobiliary Surgery, Yijishan Hospital, Wannan Medical College, Wuhu 241000, Anhui Province, China
Yi-Lin Wang, Wei-Yan Liu, Xu-Bo Wu, Department of General Surgery, Minhang Hospital, Fudan University, 201199, Shanghai, China
Yun-Jiang Zheng, Department of Emergency, Xin Hua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
Author contributions: Wang YL, Fang M and Wang XM contributed equally to this paper as co-first authors, and they designed the study and wrote the manuscript; Liu WY and Zheng YJ performed the majority of the experiments; Wu XB and Tao R provided vital analytical tools and were also involved in editing the manuscript.
Supported by Minhang District Natural Science Foundation (to Wang YL) and the Science and Technology Commission in Shanghai, No. 10411968500; and National Natural Science Foundation of China, No. 81001324
Correspondence to: Ran Tao, MD, FACS, Professor, Center for Organ Transplantation and Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 7W Surgical Building, No. 197, 2nd Ruijin Road, Shanghai 200025, China. taohdac9@yahoo.com
Telephone: 86-21-34187470
Received: May 24, 2014
Revised: August 24, 2014
Accepted: October 21, 2014
Published online: December 21, 2014
Abstract

AIM: 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.

CONCLUSION: 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.

Keywords: IL-17, HT-29, TNF-α, Inflammatory bowel disease

Core tip: Our study revealed that interleukin (IL)-17 significantly promoted the gene expression levels of tumor necrosis factor (TNF)-α-induced neutrophil chemokines and Th17 cell chemokines. It is obvious that IL-17 and TNF-α have synergistic effects on p38.