Expression of nuclear factor-?B and metalloproteinase-9 in the small intestine after traumatic brain injury / 医学研究生学报

ABSTRACT

Objective:The aim of the current study was to investigate the expression of nuclear factor-?B(NF-?B) and metalloproteinase-9(MMP-9) in the small intestine and to explore the potential role of NF-?B and MMP-9 in the damage of gut mucosal barrier after traumatic brain injury.Methods:The trauma was produced by a free-falling weight on the exposed dura of right parietal lobe.The rats were randomly divided into control group and traumatic brain injury groups at hours 3,12,24 and 72,and on day 7.NF-?B binding activity in the small intestine was studied by electrophoretic mobility shift assay(EMSA),and the expression of MMP-9 was studied by immunohistochemistry.Results:The results showed that NF-?B binding activity and MMP-9 expression in the small intestine was progressively increased,reached the maximum at 72 h and kept at high level up to 7 d after TBI.Concomitant upregulation of NF-?B~()and MMP-9 was observed.MMP-9 positively immunostained cells were mainly located at villous interstitium,lamina propria,crypt and submucosal layer,including endothelial cells,lymphocytes and neutrophils.Conclusion:It was concluded that cortical contusion trauma could induce a concomitant and persistent upregulation of NF-?B binding activity and MMP-9 expression in the small intestine which might play a central role in the~()damage of gut mucosal barrier.