Xue-mei Wang1, Yu-lan Liu. 1. Department of Gastroenterology, Peking University People's Hospital, Beijing 100044, China.
Abstract
OBJECTIVE: To study the expressions of TLR4, CD14, MD-2 and NF-κB in colonic mucosa in patients with diarrhea-irritable bowel syndrome (IBS-D), and compared with normal subjects. The purpose of this study is to explore the role of TLR4 and TLR4 signal transduction pathway in the pathogenesis of IBS-D. METHODS: The expressions of TLR4, CD14, MD-2 and NF-κB in colon mucosa were examined by immunohistochemistry (IHC) in 30 IBS-D patients and 12 healthy volunteers separately. The average absorbance (A value) of TLR4 was analyzed. The positive expression rates of CD14, MD-2 and NF-κB of colonic mucosa were studied. RESULTS: Compared with healthy controls, significant upregulation of TLR4 expression relative to controls was found in colon mucosa of IBS-D.A value of TLR4 in IBS-D was significantly higher (0.3971±0.0996 vs 0.3044±0.0481). The positive rate and intensity of NF-κB in IBS-D were significantly higher than those in healthy. The number of positive cells of MD-2 showed significant increase in lamina propria of IBS-D against controls. The percent of CD14 positive was upregulated in lamina propria in IBS-D. The expressions of MD-2 and CD14 in intestine epithelial cell were low or negative. CONCLUSIONS: There is the activation of the signal transduction pathway of TLR4/NF-κB in the colonic mucosa of patients with IBS-D. Up-regulated expression of TLR4 in IBS patients suppose that it might contribute to occurrence of IBS-D.
OBJECTIVE: To study the expressions of TLR4, CD14, MD-2 and NF-κB in colonic mucosa in patients with diarrhea-irritable bowel syndrome (IBS-D), and compared with normal subjects. The purpose of this study is to explore the role of TLR4 and TLR4 signal transduction pathway in the pathogenesis of IBS-D. METHODS: The expressions of TLR4, CD14, MD-2 and NF-κB in colon mucosa were examined by immunohistochemistry (IHC) in 30 IBS-D patients and 12 healthy volunteers separately. The average absorbance (A value) of TLR4 was analyzed. The positive expression rates of CD14, MD-2 and NF-κB of colonic mucosa were studied. RESULTS: Compared with healthy controls, significant upregulation of TLR4 expression relative to controls was found in colon mucosa of IBS-D.A value of TLR4 in IBS-D was significantly higher (0.3971±0.0996 vs 0.3044±0.0481). The positive rate and intensity of NF-κB in IBS-D were significantly higher than those in healthy. The number of positive cells of MD-2 showed significant increase in lamina propria of IBS-D against controls. The percent of CD14 positive was upregulated in lamina propria in IBS-D. The expressions of MD-2 and CD14 in intestine epithelial cell were low or negative. CONCLUSIONS: There is the activation of the signal transduction pathway of TLR4/NF-κB in the colonic mucosa of patients with IBS-D. Up-regulated expression of TLR4 in IBS patients suppose that it might contribute to occurrence of IBS-D.