Objective：To explore the significance of colonic epithelial cell apoptosis and tumor necrosis factorα（TNF-α）changing in pathogenesis of melanosis coli（MC）in guinea pig and the molecular mechanism of rhubarb（Rh...Objective：To explore the significance of colonic epithelial cell apoptosis and tumor necrosis factorα（TNF-α）changing in pathogenesis of melanosis coli（MC）in guinea pig and the molecular mechanism of rhubarb（Rhu）in inducing the disease,by means of using different dosages of Rhu to induce the disease. Methods：One hundred and forty-four male guinea pigs,clean grade,were randomized according to their body weight into 5 groups,the untreated normal group and the 4 Rhu groups treated,respectively,with different doses of Rhu,3 g/kg·d for low dose（Rhu-I）group,6 g/kg·d for moderate dose（Rhu-m）group,12 g/kg·d for high dose（Rhu-h）group and 24 g/kg·d for super-high dose（Rhu-s）group via gastric infusion.All animals were sacrificed 60 days later,their viscera were taken for observing the pathologic and morphologic changes with HE, melanin and melatonin staining,and the apoptosis of colonic epithelial cells was detected with TUNEL stain and transmission electric microscopy.In addition,the levels of TNF-αin serum and colonic tissue were measured using ELISA and RT-PCR.Results：The pathological changes of MC could be found by naked eye in all Rhu groups,especially apparent at caecum and proximal end of colon,but did not found in gallbladder,jejunum and ileum.In normal guinea pigs,the colonic membrane was pink in color with no apparent pigment deposition. Membranous color deepened in the Rhu groups depending on the dosage of Rhu used.MC scoring showed the highest scores revealed in the Rhu-s group（6.00±0.00）,which was significantly different to those in the Rhu-I （3.86±0.69）,Rhu-m（4.43±0.79）and Rhu-h groups（4.88±0.35,all P0.05）.Levels of cell apoptosis in colon and TNF-αin serum in all Rhu groups were higher than those in the normal group（P0.01）,but showed no significant difference among the Rhu groups（P0.05）.Moreover,a positive correlation was found in the degree of induced MC with apoptosis rate and TNF-αlevel.Conclusions：Rhu（anthraquinone purgatives）had 展开更多
OBJECTIVE Although it is generally believed that nicotine accounts for the beneficial effect of smoking on ulcerative colitis,the underlying mechanisms remain not well-understood.Our previous finding that nicotine inh...OBJECTIVE Although it is generally believed that nicotine accounts for the beneficial effect of smoking on ulcerative colitis,the underlying mechanisms remain not well-understood.Our previous finding that nicotine inhibits inflammatory responses through inducing miRNA-124 prompted us to ask whether the miRNA is involved in the protective action of nicotine on UC.METHODS Mi R-124 expression in colon tissues and cells was determined by q-PCR and in situ hybridization.The effect of miR-124 on protective role of nicotine in ulcerative colitis was evaluated in DSS-treated mice and IL-6-treated Caco-2 colon epithelial cells.Expression of p-STAT3/STAT3 was detected by immunohistochemistry and Western blot analysis.RESULTS miR-124 expression is upregulated in colon tissues from patients and DSS-induced colitis.Nicotine treatment further elevated miR-124 level in colon tissues of the mice,in infiltrated lymphocytes and epithelial cells,and augmented miR-124 expression in lymphocytes isolated from human ulcerative colon tissues.Administration of nicotine also reduced weight loss,improved DAI and decreased HE score in DSS-induced colitis.Moreover,knockdown of miR-124 in vivo significantly diminished the beneficial effect of nicotine,and in vitro on IL-6-treated Caco-2 colon epithelial cells.Further analysis indicated that nicotine inhibited STAT3 activation in vivo and in IL-6-treated Caco-2 colon epithelial cells and Jurkat human T lymphocytes,in whichmiR-124 knockdown led to increased activation of STAT3.CONCLUSION These data indicated that nicotine exerts its protective action in UC through inducing miR-124 and its effect on STAT3,suggesting that the miR-124/STAT3 system is a potential target for the therapeutic intervention of UC.展开更多
基金Supported by Zhejiang Provincial Funds of Natural Sciences (No.X206959)the Key Project Item of Hangzhou Municipal Administration of Science and Technology(No.2006533Q15)
文摘Objective：To explore the significance of colonic epithelial cell apoptosis and tumor necrosis factorα（TNF-α）changing in pathogenesis of melanosis coli（MC）in guinea pig and the molecular mechanism of rhubarb（Rhu）in inducing the disease,by means of using different dosages of Rhu to induce the disease. Methods：One hundred and forty-four male guinea pigs,clean grade,were randomized according to their body weight into 5 groups,the untreated normal group and the 4 Rhu groups treated,respectively,with different doses of Rhu,3 g/kg·d for low dose（Rhu-I）group,6 g/kg·d for moderate dose（Rhu-m）group,12 g/kg·d for high dose（Rhu-h）group and 24 g/kg·d for super-high dose（Rhu-s）group via gastric infusion.All animals were sacrificed 60 days later,their viscera were taken for observing the pathologic and morphologic changes with HE, melanin and melatonin staining,and the apoptosis of colonic epithelial cells was detected with TUNEL stain and transmission electric microscopy.In addition,the levels of TNF-αin serum and colonic tissue were measured using ELISA and RT-PCR.Results：The pathological changes of MC could be found by naked eye in all Rhu groups,especially apparent at caecum and proximal end of colon,but did not found in gallbladder,jejunum and ileum.In normal guinea pigs,the colonic membrane was pink in color with no apparent pigment deposition. Membranous color deepened in the Rhu groups depending on the dosage of Rhu used.MC scoring showed the highest scores revealed in the Rhu-s group（6.00±0.00）,which was significantly different to those in the Rhu-I （3.86±0.69）,Rhu-m（4.43±0.79）and Rhu-h groups（4.88±0.35,all P0.05）.Levels of cell apoptosis in colon and TNF-αin serum in all Rhu groups were higher than those in the normal group（P0.01）,but showed no significant difference among the Rhu groups（P0.05）.Moreover,a positive correlation was found in the degree of induced MC with apoptosis rate and TNF-αlevel.Conclusions：Rhu（anthraquinone purgatives）had
基金supported by National Natural Science Foundation of China(81273606,81473259 to XL,81603116 to YS)National Science and Technology Major Project(2014ZX09J14103-08C to XL)
文摘OBJECTIVE Although it is generally believed that nicotine accounts for the beneficial effect of smoking on ulcerative colitis,the underlying mechanisms remain not well-understood.Our previous finding that nicotine inhibits inflammatory responses through inducing miRNA-124 prompted us to ask whether the miRNA is involved in the protective action of nicotine on UC.METHODS Mi R-124 expression in colon tissues and cells was determined by q-PCR and in situ hybridization.The effect of miR-124 on protective role of nicotine in ulcerative colitis was evaluated in DSS-treated mice and IL-6-treated Caco-2 colon epithelial cells.Expression of p-STAT3/STAT3 was detected by immunohistochemistry and Western blot analysis.RESULTS miR-124 expression is upregulated in colon tissues from patients and DSS-induced colitis.Nicotine treatment further elevated miR-124 level in colon tissues of the mice,in infiltrated lymphocytes and epithelial cells,and augmented miR-124 expression in lymphocytes isolated from human ulcerative colon tissues.Administration of nicotine also reduced weight loss,improved DAI and decreased HE score in DSS-induced colitis.Moreover,knockdown of miR-124 in vivo significantly diminished the beneficial effect of nicotine,and in vitro on IL-6-treated Caco-2 colon epithelial cells.Further analysis indicated that nicotine inhibited STAT3 activation in vivo and in IL-6-treated Caco-2 colon epithelial cells and Jurkat human T lymphocytes,in whichmiR-124 knockdown led to increased activation of STAT3.CONCLUSION These data indicated that nicotine exerts its protective action in UC through inducing miR-124 and its effect on STAT3,suggesting that the miR-124/STAT3 system is a potential target for the therapeutic intervention of UC.
