Na Wang1, Gai Wang, JingXia Hao, JunJi Ma, Yan Wang, XiaoYu Jiang, HuiQing Jiang. 1. Department of Gastroenterology, Hebei Key Laboratory of Gastroenterology, Hebei Institute of Gastroenterology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, China.
Abstract
BACKGROUND: Disruption of epithelial tight junctions (TJ) followed by loss of barrier function is of crucial importance in the pathogenesis of a variety of gastrointestinal disorders. Heme oxygenase-1 (HO-1), which can be induced by curcumin (Cur), provides protection against various forms of oxidative stress. AIMS: The protective effect of Cur on oxidative stress-induced intestinal barrier disruption in human intestinal epithelial cells was elucidated in this study. METHODS: H(2)O(2)-induced Caco-2 enterocytic monolayers were incubated in the presence or absence of Cur and/or zinc protoporphyrin (ZnPP). The trans-epithelial electrical resistance (TEER) and the flux of sodium fluorescein in the filter-grown Caco-2 cell monolayers were measured. The expression and localization of the TJ protein occludin and zonula occluden-1 (ZO-1) were evaluated by western blot and immunofluorescence microscopy. The mRNA and protein levels of HO-1 were analyzed by real-time PCR and western blot. RESULTS: Cur attenuated H(2)O(2)-induced disruption of paracellular permeability (TEER 52.02 ± 10.15% vs 22.71 ± 3.11%; sodium fluorescein flux 12.41 ± 2.19% vs 32.00 ± 4.97%, P < 0.05) and induced HO-1 mRNA (6.64 ± 0.48 vs 3.22 ± 0.28, P < 0.05) and protein (291.00 ± 9.17% vs 99.00 ± 10.00%, P < 0.05) expression in Caco-2 cells. After administration of H(2)O(2), occludin and ZO-1 proteins were restored by Cur (occludin 175.67 ± 29.50% vs 53.67 ± 24.19%, P < 0.05; ZO-1 139.67 ± 33.71% vs 36.00 ± 15.88%, P < 0.05) and this effect was blocked by HO-1 inhibitor, ZnPP (occludin 54.67 ± 10.02% vs 168.33 ± 36.47%, P < 0.05; ZO-1 50.00 ± 15.13% vs 117.67 ± 38.81%, P < 0.05). CONCLUSION: Cur protects human intestinal epithelial cells against H(2)O(2)-induced disruption of TJ and barrier dysfunction via the HO-1 pathway.
BACKGROUND: Disruption of epithelial tight junctions (TJ) followed by loss of barrier function is of crucial importance in the pathogenesis of a variety of gastrointestinal disorders. Heme oxygenase-1 (HO-1), which can be induced by curcumin (Cur), provides protection against various forms of oxidative stress. AIMS: The protective effect of Cur on oxidative stress-induced intestinal barrier disruption in human intestinal epithelial cells was elucidated in this study. METHODS:H(2)O(2)-induced Caco-2 enterocytic monolayers were incubated in the presence or absence of Cur and/or zinc protoporphyrin (ZnPP). The trans-epithelial electrical resistance (TEER) and the flux of sodium fluorescein in the filter-grown Caco-2 cell monolayers were measured. The expression and localization of the TJ protein occludin and zonula occluden-1 (ZO-1) were evaluated by western blot and immunofluorescence microscopy. The mRNA and protein levels of HO-1 were analyzed by real-time PCR and western blot. RESULTS: Cur attenuated H(2)O(2)-induced disruption of paracellular permeability (TEER 52.02 ± 10.15% vs 22.71 ± 3.11%; sodium fluorescein flux 12.41 ± 2.19% vs 32.00 ± 4.97%, P < 0.05) and induced HO-1 mRNA (6.64 ± 0.48 vs 3.22 ± 0.28, P < 0.05) and protein (291.00 ± 9.17% vs 99.00 ± 10.00%, P < 0.05) expression in Caco-2 cells. After administration of H(2)O(2), occludin and ZO-1 proteins were restored by Cur (occludin 175.67 ± 29.50% vs 53.67 ± 24.19%, P < 0.05; ZO-1 139.67 ± 33.71% vs 36.00 ± 15.88%, P < 0.05) and this effect was blocked by HO-1 inhibitor, ZnPP (occludin 54.67 ± 10.02% vs 168.33 ± 36.47%, P < 0.05; ZO-1 50.00 ± 15.13% vs 117.67 ± 38.81%, P < 0.05). CONCLUSION: Cur protects human intestinal epithelial cells against H(2)O(2)-induced disruption of TJ and barrier dysfunction via the HO-1 pathway.
Authors: Stephen M Vindigni; Timothy L Zisman; David L Suskind; Christopher J Damman Journal: Therap Adv Gastroenterol Date: 2016-04-19 Impact factor: 4.409