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
Several groups are investigating the mechanisms of action of therapeutic immunoglobulins (IVIg) in order to improve their use. In vitro models such as CD40-CD154 interaction are necessary to study the physiological re...Several groups are investigating the mechanisms of action of therapeutic immunoglobulins (IVIg) in order to improve their use. In vitro models such as CD40-CD154 interaction are necessary to study the physiological response of human B lymphocytes to IVIg. Human B lymphocytes treated with IVIg triggers a rapid phospho-rylation (<1 h) of extracellular-regulated kinases 1 and 2 (ERK1/2), which subsequently results in increased differentiation and decreased pro-liferation. However, the modulation of human lymphocyte physiology by IVIg is a gradual and cumulative process and requires long-term experimentation. Differentiation of human B lymphocytes into Ig-secreting cells can be evaluated both at the transcription and translation levels. The secretion of immunoglobulins can be assessed using ELISA or ELISPOTS whereas expression of immunoglobulin genes can be measured using semi-quantitative or quantitative PCR methods. We hereby report a comparison of these methods to explain how contradictory observations towards IVIg effects could result from their use. Our results indicate that ELISA and ELISPOTS will provide consistent observations by opposition to real-time PCR quantification. Besides, the reliability of each of these me-thods remained dependent on the stimulation period as well as the preparation of cellular extracts or cell samples following IVIg-treatment.展开更多
应用人外周血淋巴细胞和小鼠淋巴细胞彗星试验,对长治市5个样点的地下水有机浓集物进行了遗传毒性研究。结果表明,各水样中有机浓集物在3个染毒剂量50,200,800 m L·管-1条件下均可对人外周血淋巴细胞和小鼠淋巴细胞DNA产生不同程...应用人外周血淋巴细胞和小鼠淋巴细胞彗星试验,对长治市5个样点的地下水有机浓集物进行了遗传毒性研究。结果表明,各水样中有机浓集物在3个染毒剂量50,200,800 m L·管-1条件下均可对人外周血淋巴细胞和小鼠淋巴细胞DNA产生不同程度的遗传损伤,并且随着浓度的升高,DNA损伤程度明显增加,各实验组与溶剂对照组相比有P<0.05或P<0.01显著差异。研究表明,上述2种淋巴细胞彗星试验可有效地检测地下水体有机污染物的遗传毒性。展开更多
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.
文摘Several groups are investigating the mechanisms of action of therapeutic immunoglobulins (IVIg) in order to improve their use. In vitro models such as CD40-CD154 interaction are necessary to study the physiological response of human B lymphocytes to IVIg. Human B lymphocytes treated with IVIg triggers a rapid phospho-rylation (<1 h) of extracellular-regulated kinases 1 and 2 (ERK1/2), which subsequently results in increased differentiation and decreased pro-liferation. However, the modulation of human lymphocyte physiology by IVIg is a gradual and cumulative process and requires long-term experimentation. Differentiation of human B lymphocytes into Ig-secreting cells can be evaluated both at the transcription and translation levels. The secretion of immunoglobulins can be assessed using ELISA or ELISPOTS whereas expression of immunoglobulin genes can be measured using semi-quantitative or quantitative PCR methods. We hereby report a comparison of these methods to explain how contradictory observations towards IVIg effects could result from their use. Our results indicate that ELISA and ELISPOTS will provide consistent observations by opposition to real-time PCR quantification. Besides, the reliability of each of these me-thods remained dependent on the stimulation period as well as the preparation of cellular extracts or cell samples following IVIg-treatment.
文摘应用人外周血淋巴细胞和小鼠淋巴细胞彗星试验,对长治市5个样点的地下水有机浓集物进行了遗传毒性研究。结果表明,各水样中有机浓集物在3个染毒剂量50,200,800 m L·管-1条件下均可对人外周血淋巴细胞和小鼠淋巴细胞DNA产生不同程度的遗传损伤,并且随着浓度的升高,DNA损伤程度明显增加,各实验组与溶剂对照组相比有P<0.05或P<0.01显著差异。研究表明,上述2种淋巴细胞彗星试验可有效地检测地下水体有机污染物的遗传毒性。
