Basic Research
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 28, 2005; 11(8): 1149-1154
Published online Feb 28, 2005. doi: 10.3748/wjg.v11.i8.1149
Up-regulation of intestinal nuclear factor kappa B and intercellular adhesion molecule-1 following traumatic brain injury in rats
Chun-Hua Hang, Ji-Xin Shi, Jie-Shou Li, Wei-Qin Li, Hong-Xia Yin
Chun-Hua Hang, Ji-Xin Shi, Hong-Xia Yin, Department of Neurosurgery, Jinling Hospital, Clinical School of Medicine, Nanjing University, Nanjing 210002, Jiangsu Province, China
Jie-Shou Li, Wei-Qin Li, Research Institute of General Surgery, Jinling Hospital, Clinical School of Medicine, Nanjing University, Nanjing 210002, Jiangsu Province, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Chun-Hua Hang, Department of Neurosurgery, Jinling Hospital, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province, China.
Telephone: +86-25-80860010 Fax: +86-25-84810987
Received: June 29, 2004
Revised: July 1, 2004
Accepted: July 15, 2004
Published online: February 28, 2005

AIM: Nuclear factor kappa B (NF-κB) regulates a large number of genes involved in the inflammatory response to critical illnesses, but it is not known if and how NF-κB is activated and intercellular adhesion molecule-1 (ICAM-1) expressed in the gut following traumatic brain injury (TBI). The aim of current study was to investigate the temporal pattern of intestinal NF-κB activation and ICAM-1 expression following TBI.

METHODS: Male Wistar rats were randomly divided into six groups (6 rats in each group) including controls with sham operation and TBI groups at hours 3, 12, 24, and 72, and on d 7. Parietal brain contusion was adopted using weight-dropping method. All rats were decapitated at corresponding time point and mid-jejunum samples were taken. NF-κB binding activity in jejunal tissue was measured using EMSA. Immunohistochemistry was used for detection of ICAM-1 expression in jejunal samples.

RESULTS: There was a very low NF-κB binding activity and little ICAM-1 expression in the gut of control rats after sham surgery. NF-κB binding activity in jejunum significantly increased by 160% at 3 h following TBI (P<0.05 vs control), peaked at 72 h (500% increase) and remained elevated on d 7 post-injury by 390% increase. Compared to controls, ICAM-1 was significantly up-regulated on the endothelia of microvessels in villous interstitium and lamina propria by 24 h following TBI and maximally expressed at 72 h post-injury (P<0.001). The endothelial ICAM-1 immunoreactivity in jejunal mucosa still remained strong on d 7 post-injury. The peak of NF-κB activation and endothelial ICAM-1 expression coincided in time with the period during which secondary mucosal injury of the gut was also at their culmination following TBI.

CONCLUSION: TBI could induce an immediate and persistent up-regulation of NF-κB activity and subsequent up-regulation of ICAM-1 expression in the intestine. Inflammatory response mediated by increased NF-κB activation and ICAM-1 expression may play an important role in the pathogenesis of acute gut mucosal injury following TBI.

Keywords: Traumatic brain injury, Intestine, Nuclear factor kappa B, Intercellular adhesion molecule-1, Inflammatory response