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World J Hepatol. Jun 27, 2010; 2(6): 233-238
Published online Jun 27, 2010. doi: 10.4254/wjh.v2.i6.233
Significance of MD-2 and MD-2B expression in rat liver during acute cholangitis
Hui-Lai Miao, Zhi-Dong Qiu, Fu-Long Hao, Yong-Hui Bi, Ming-Yi Li, Ming Chen, Nian-Ping Chen, Fei Zhou
Hui-Lai Miao, Zhi-Dong Qiu, Ming-Yi Li, Ming Chen, Nian-Ping Chen, Department of Hepatobiliary Surgery, the Affiliated Hospital of Guangdong Medical College, Zhanjing 524001, Guangdong Province, China
Fu-Long Hao, Yong-Hui Bi, Fei Zhou, Department of Hepatobiliary Surgery, Research Institute of Guangdong Medical College, Zhanjiang 524001, Guangdong Province, China
Author contributions: Miao HL was responsible for making the plan and design of work, interpreting and discussing the results, writing and revising the manuscript and financial support; Qiu ZD helped in the performance of laboratory investigations, collection of data, writing and revising the manuscript; Hao FL and Bi YH interpreted and discussed the results of fluorescence quantitative PCR, closely supervised the different sets of fluorescence quantitative PCR, wrote and revised the text; Li MY provided scientific supervision of the work; Chen M helped in the interpretation and discussion of the results and performance of laboratory investigations; Chen NP gave scientific interpretation of the results of liver biopsies; and Zhou F established the animal model, analyzed and processed data.
Supported by the Medical Technology Research Foundation of Guangdong Province, No. A2008475
Correspondence to: Hui-Lai Miao, MD, Professor of Surgery, Department of Hepatobiliary Surgery, the Affiliated Hospital of Guangdong Medical College, No. 57 Renmin Road, Xiashan 524001, Guangdong Province, China. miaohuilai@tom.com
Telephone: +86-759-2387417 Fax: +86-759-2231754
Received: March 19, 2010
Revised: June 11, 2010
Accepted: June 18, 2010
Published online: June 27, 2010
Abstract

AIM: To investigate the expression of myeloid differentiation protein-2 (MD-2), MD-2B (a splicing isoform of MD-2 that can block Toll-like receptor 4 (TLR4)/MD-2 LPS-mediated signal transduction) and TLR4 in the liver of acute cholangitis rats.

METHODS: Male Sprague-Dawley rats (SPF level) were randomly divided into four groups: (A) sham-operated group; (B) simple common bile duct ligation group; (C) acute cholangitis group; and (D) acute cholangitis anti-TLR4 intervention group (n = 25 per group). Rat liver tissue samples were used to detect TLR4, MD-2 and MD-2B mRNA expression by fluorescence quantitative PCR in parallel with pathological changes.

RESULTS: In acute cholangitis, liver TLR4 and MD-2 mRNA expression levels at 6, 12, 24, 48 and 72 h were gradually up-regulated but MD-2B mRNA expression gradually down-regulated (P < 0.05). After TLR4 antibody treatment, TLR4 and MD-2 mRNA expression were lower compared with the acute cholangitis group (P < 0.05). However, MD-2B mRNA expression was higher than in the acute cholangitis group (P < 0.05). MD-2 and TLR4 mRNA expressions were positively correlated (r = 0.94981, P < 0.05) and MD-2B mRNA expression was negatively correlated with MD-2 and TLR4 mRNA (r = -0.89031, -0.88997, P < 0.05).

CONCLUSION: In acute cholangitis, MD-2 plays an important role in the process of TLR4- mediated inflammatory response to liver injury while MD-2B plays a negative regulatory role.

Keywords: Acute cholangitis; Toll-like receptor 4; Myeloid differentiation protein-2; Myeloid differentiation protein-2 splicing isoform