Yajun Zhang1,2, Xiaohui Wang2, Shaoxin Wang2, Zhihui Yan2, Chao Li2, Yan Zheng2, Lihong Cui3,4. 1. The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510280, Guangdong Province, China. 2. Department of Gastroenterology, The Sixth Medical Center, PLA General Hospital, NO. 6 Fucheng Road, Haidian District, Beijing, 100048, China. 3. The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510280, Guangdong Province, China. luckycui861@sina.com. 4. Department of Gastroenterology, The Sixth Medical Center, PLA General Hospital, NO. 6 Fucheng Road, Haidian District, Beijing, 100048, China. luckycui861@sina.com.
Abstract
BACKGROUND: The specific and accurate pathogenesis of diarrhea-type irritable bowel syndrome is still unclear. AIMS: We explored the mechanism of heat shock protein 27 (HSP27) in diarrhea-type irritable bowel syndrome to identify the key targets for the disease. METHODS: The human colonic epithelial cell lines Caco-2 and NCM460 were pretreated with KRIBB3 (a phosphorylation inhibitor of HSP27) and then stimulated with lipopolysaccharide for different times. The apoptosis ratios of Caco-2 and NCM460 cells were examined with Annexin V/PI assays. Cell growth was determined using the cell counting kit-8 assay, and the expression levels of IL-1β and IL-6 in the cell supernatant were analyzed by ELISA. In addition, the expression levels of HSP27 and the nuclear factor-κB (NF-κB) signaling pathway were examined by Western blot assay. RESULTS: Stimulation with lipopolysaccharide promoted the expression of HSP27 in colonic epithelial cells. HSP27 was phosphorylated at serine 78 and 82 after exposure to LPS. Apoptosis, growth inhibition, and inflammatory factor expression of lipopolysaccharide-induced colonic epithelial cells were greatly exacerbated by KRIBB3 treatment. In addition, KRIBB3 inhibited the phosphorylation of IκB-α and the activation of NF-κB. Gene silencing by small interfering RNA indicated that phosphorylation of HSP27 may regulate the NF-κB pathway. CONCLUSIONS: HSP27 plays an important role in the inflammatory response of intestinal human colonic epithelial cells. HSP27 may protect intestinal epithelial cells against damage by regulating the NF-κB pathway.
BACKGROUND: The specific and accurate pathogenesis of diarrhea-type irritable bowel syndrome is still unclear. AIMS: We explored the mechanism of heat shock protein 27 (HSP27) in diarrhea-type irritable bowel syndrome to identify the key targets for the disease. METHODS: The human colonic epithelial cell lines Caco-2 and NCM460 were pretreated with KRIBB3 (a phosphorylation inhibitor of HSP27) and then stimulated with lipopolysaccharide for different times. The apoptosis ratios of Caco-2 and NCM460 cells were examined with Annexin V/PI assays. Cell growth was determined using the cell counting kit-8 assay, and the expression levels of IL-1β and IL-6 in the cell supernatant were analyzed by ELISA. In addition, the expression levels of HSP27 and the nuclear factor-κB (NF-κB) signaling pathway were examined by Western blot assay. RESULTS: Stimulation with lipopolysaccharide promoted the expression of HSP27 in colonic epithelial cells. HSP27 was phosphorylated at serine 78 and 82 after exposure to LPS. Apoptosis, growth inhibition, and inflammatory factor expression of lipopolysaccharide-induced colonic epithelial cells were greatly exacerbated by KRIBB3 treatment. In addition, KRIBB3 inhibited the phosphorylation of IκB-α and the activation of NF-κB. Gene silencing by small interfering RNA indicated that phosphorylation of HSP27 may regulate the NF-κB pathway. CONCLUSIONS:HSP27 plays an important role in the inflammatory response of intestinal human colonic epithelial cells. HSP27 may protect intestinal epithelial cells against damage by regulating the NF-κB pathway.
Authors: Jie Ruan; Zhilin Qi; Lei Shen; Yi Jiang; Yimiao Xu; Lei Lan; Lan Luo; Zhimin Yin Journal: Biochem Biophys Res Commun Date: 2014-11-21 Impact factor: 3.575