Original Article
Copyright ©2010 Baishideng. All rights reserved
World J Gastroenterol. May 14, 2010; 16(18): 2252-2259
Published online May 14, 2010. doi: 10.3748/wjg.v16.i18.2252
Expression of interleukin 6 in brain and colon of rats with TNBS-induced colitis
Kai Wang, Chuan-Ping Yuan, Wei Wang, Zhan-Qing Yang, Wei Cui, Lian-Zhi Mu, Zhan-Peng Yue, Xiu-Ling Yin, Zhong-Ming Hu, Ju-Xiong Liu
Kai Wang, Chuan-Ping Yuan, Wei Wang, Zhan-Qing Yang, Wei Cui, Lian-Zhi Mu, Zhan-Peng Yue, Ju-Xiong Liu, Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Science and Veterinary Medicine, Jilin University, Changchun 130062, Jilin Province, China
Xiu-Ling Yin, Department of Veterinary Medicine, University of Hebei Northern, Zhangjiakou 075029, Hebei Province, China
Kai Wang, Zhong-Ming Hu, The Academy of Military Medical Sciences, Beijing 100071, China
Author contributions: Wang K and Yuan CP performed the majority of experiments; Wang W, Yang ZQ and Yue ZP provided vital reagents and analytical tools and were also involved in editing the manuscript; Cui W, Yin XL, Mu LZ and Yuan CP co-ordinated and established the model of IBD; Wang K, Yuan CP and Wang W collected all the materials and completed the analyses of IL-6 through real-time RT-PCR and immunohistochemistry; Wang W, Hu ZM and Liu JX designed the study and wrote the manuscript.
Supported by The grant from the National Natural Science Foundation of China, No. 30871840; No. 30901057
Correspondence to: Dr. Ju-Xiong Liu, Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Science and Veterinary Medicine, Jilin University, 5333 Xi’an Avenue, Changchun 130062, Jilin Province, China. juxiongliu@sina.com
Telephone: +86-431-87836163 Fax: +86-431-87836163
Received: November 24, 2009
Revised: January 11, 2010
Accepted: January 18, 2010
Published online: May 14, 2010
Abstract

AIM: To characterise expression of interleukin 6 (IL-6), a potent proinflammatory cytokine, in the occurrence and development of inflammatory bowel disease (IBD) and investigate its effect on neuroimmunomodulation and immune homeostasis regulation.

METHODS: In this study, rats with colitis induced by trinitrobenzene sulfonic acid (TNBS) were sacrificed on days 3, 7, 14, 21 and 28 after induction. In the controls, the TNBS was just replaced by equivalent amount of phosphate buffered solution (PBS, 0.01 mol/L). IL-6 mRNA expression in brain and colon tissues in each phase was evaluated by real-time reverse transcription-polymerase chain reaction, and cellular localisation and protein level of IL-6 was determined by immunohistochemistry.

RESULTS: At day 7, mRNA expression of IL-6 was significantly higher in the colon and brain of IBD rats than that of the controls. The protein level was also significantly higher in colon, hypothalamus and cerebral cortex of IBD rats compared with the controls. So there are similar temporal trends in IL-6 mRNA expression and protein levels in all positions with a persistent increase to a peak at day 7, followed by a decline and gradual return to normal levels.

CONCLUSION: These results revealed that changes in IL-6 expression in brain and colon tissues occur in different phases of IBD. Therefore, we propose that the nerve centre regulates and controls the occurrence and development of IBD via IL-6.

Keywords: Inflammatory bowel disease, Interleukin 6, Neuroimmunomodulation, Real-time transcription-polymerase chain reaction, Immunohistochemistry