Objective. Polyethylene glycol (PEG), an osmotic laxative, is a potent inhibitor of colon cancer in rats. In a search for the underling mechanisms, the hypothesis that fecal bulking and moisture decrease colon carcino...Objective. Polyethylene glycol (PEG), an osmotic laxative, is a potent inhibitor of colon cancer in rats. In a search for the underling mechanisms, the hypothesis that fecal bulking and moisture decrease colon carcinogenesis was tested. We also investigated the PEG effects on crypt cells in vivo . Material and methods. Fischer 344 rats ( n =272) were injected with the colon carcinogen, azoxy-methane. They were then randomized to a standard AIN76 diet containing one of 19 laxative agents (5%w/w in most cases): PEG 8000 and other PEG-like compounds, carboxymethylcellulose, polyvinylpyrrolidone, sodium polyacrylate, calcium polycarbophil, karaya gum, psyllium, mannitol, sorbitol, lactulose, propylene glycol, magnesium hydroxide, sodium phosphate, bisacodyl, docusate, and paraffin oil. Aberrant crypt foci (ACF) and fecal values were measured blindly after a 30-day treatment regimen. Proliferation, apoptosis, and the removal of cells from crypts were studied in control and PEG-fed rats using various methods, including TUNEL and fluorescein dextran labeling. Results. PEG 8000 reduced the number of ACF 9-fold in rats ( >40-fold) a fecal marker of epitheliolysis in the gut ( p < 0.001). PEG normalized the percentage of fluorescein dextran labeled cells on the top of ACF ( p < 0.001). Conclusions. Among laxatives, only PEG afforded potent chemoprevention. PEG protection was not due to increased fecal bulking, but in all likelihood to the elimination of cells from precancerous lesions.展开更多
目的:探讨参苓白术散抗脂多糖(lipopolysaccharide,LPS)诱导肠上皮隐窝细胞(intestinal crypt cel ls,IEC-6)通透性变化的机制研究。方法:将IEC-6细胞分为空白组、LPS模型组、LPS+参苓白术散含药血清低、中、高剂量组、10%FBS。对以下...目的:探讨参苓白术散抗脂多糖(lipopolysaccharide,LPS)诱导肠上皮隐窝细胞(intestinal crypt cel ls,IEC-6)通透性变化的机制研究。方法:将IEC-6细胞分为空白组、LPS模型组、LPS+参苓白术散含药血清低、中、高剂量组、10%FBS。对以下指标进行检测:IEC-6细胞凋亡、细胞内钙离子浓度、IEC-6电阻值变化、检测各组中磷酸化Rho激酶(ROCKⅡ)、肌球蛋白轻链激酶(MLCK)以及凋亡因子Caspase-3表达。结果:LPS显著引起IEC-6细胞凋亡而参岺白术散的含药血清明显抑制细胞凋亡。与空白组比较,模型组IEC-6细胞跨膜电阻的TEER值显著下降(P<0.01);与LPS模型组比较,参苓白术散含药血清低、中、高剂量组IEC-6细胞跨膜电阻的TEER值显著升高,实验结果具有统计学意义(P<0.01)。LPS模型组的钙离子浓度明显高于空白组(P<0.01);不同浓度的参苓白术散含药血清组的钙离子浓度明显低于LPS模型组(P<0.01)。与空白组比较,模型组中磷酸化ROCKⅡ、MLCK蛋白表达明显升高(P<0.05);与模型组比较,不同剂量参苓白术散含药血清组中磷酸化ROCKⅡ、MLCK蛋白表达明显降低(P<0.05)。结论:参苓白术散含药血清对LPS诱导的IEC-6细胞损伤具有明显地抑制作用,与抑制细胞凋亡及IEC-6细胞通透性的改善有关。展开更多
目的研究骆驼刺提取物(Alhagi pseudalhagi(M.B.)Desv.Extract,APE)对脂多糖诱导的大鼠小肠隐窝上皮细胞(Intestinal epithelial cell,IEC-6)损伤模型NLRP3炎症小体及相关细胞因子的影响。方法培养IEC-6细胞,将其分为空白组、模型组、AP...目的研究骆驼刺提取物(Alhagi pseudalhagi(M.B.)Desv.Extract,APE)对脂多糖诱导的大鼠小肠隐窝上皮细胞(Intestinal epithelial cell,IEC-6)损伤模型NLRP3炎症小体及相关细胞因子的影响。方法培养IEC-6细胞,将其分为空白组、模型组、APE低、中、高浓度组,用1.0μg/mL的脂多糖(Lipopolysaccharide,LPS)诱导建立细胞炎症损伤模型,APE(低、中、高浓度:15、25、35μg/mL)干预后采用CCK-8法检测细胞的存活率,通过ELISA试剂盒检测炎症因子IL-1β、IL-18、TNF-α的分泌水平。蛋白质印迹法(WB)检测核苷酸结合寡聚化结构域样受体蛋白3(Nucleotide-binding oligomerization domain-like receptor protein 3,NLRP3)炎症小体信号通路5个关键蛋白:NLRP3、半胱氨酸天冬氨酸蛋白酶1(Cystein-asparate protease-1,Caspase-l)、凋亡相关斑点样蛋白(Apoptosis-associated speck-like protein containing a CARD,ASC)及抗凋亡蛋白Bcl-2(Anti-apoptosis Protein Bcl-2)和Bcl-xl(Anti-apoptosis Protein Bcl-xl)表达。结果与空白组比较,模型组IEC-6细胞的存活率降低,NLRP3、Caspase-1、ASC蛋白表达水平升高,抗凋亡蛋白Bcl-2、Bcl-xl的表达水平降低,促炎因子IL-1β、IL-18和TNF-α的分泌水平升高,差异有统计学意义(P<0.05)。与模型组比较,APE低、中、高浓度组细胞存活率升高,35μg/mL APE组IEC-6细胞的NLRP3、Caspase-1、ASC蛋白相对表达水平降低,抗凋亡蛋白Bcl-2、Bcl-xl的表达水平升高,差异有统计学意义(P<0.05)。中、高浓度的APE能够抑制炎症因子分泌,25μg/mL APE对IL-1β、IL-18、TNF-α炎症因子分泌水平抑制率分别为31.60%、31.19%和31.09%(P<0.05)。结论骆驼刺提取物通过提高抗凋亡蛋白Bcl-2、Bcl-xl的表达水平,下调NLRP3炎症小体组成成分以及促炎因子IL-1β、IL-18和TNF-α分泌,从而抑制NLRP3炎症小体组装和激活,实现缓解LPS对IEC-6细胞的损伤。展开更多
文摘Objective. Polyethylene glycol (PEG), an osmotic laxative, is a potent inhibitor of colon cancer in rats. In a search for the underling mechanisms, the hypothesis that fecal bulking and moisture decrease colon carcinogenesis was tested. We also investigated the PEG effects on crypt cells in vivo . Material and methods. Fischer 344 rats ( n =272) were injected with the colon carcinogen, azoxy-methane. They were then randomized to a standard AIN76 diet containing one of 19 laxative agents (5%w/w in most cases): PEG 8000 and other PEG-like compounds, carboxymethylcellulose, polyvinylpyrrolidone, sodium polyacrylate, calcium polycarbophil, karaya gum, psyllium, mannitol, sorbitol, lactulose, propylene glycol, magnesium hydroxide, sodium phosphate, bisacodyl, docusate, and paraffin oil. Aberrant crypt foci (ACF) and fecal values were measured blindly after a 30-day treatment regimen. Proliferation, apoptosis, and the removal of cells from crypts were studied in control and PEG-fed rats using various methods, including TUNEL and fluorescein dextran labeling. Results. PEG 8000 reduced the number of ACF 9-fold in rats ( >40-fold) a fecal marker of epitheliolysis in the gut ( p < 0.001). PEG normalized the percentage of fluorescein dextran labeled cells on the top of ACF ( p < 0.001). Conclusions. Among laxatives, only PEG afforded potent chemoprevention. PEG protection was not due to increased fecal bulking, but in all likelihood to the elimination of cells from precancerous lesions.
文摘目的:探讨参苓白术散抗脂多糖(lipopolysaccharide,LPS)诱导肠上皮隐窝细胞(intestinal crypt cel ls,IEC-6)通透性变化的机制研究。方法:将IEC-6细胞分为空白组、LPS模型组、LPS+参苓白术散含药血清低、中、高剂量组、10%FBS。对以下指标进行检测:IEC-6细胞凋亡、细胞内钙离子浓度、IEC-6电阻值变化、检测各组中磷酸化Rho激酶(ROCKⅡ)、肌球蛋白轻链激酶(MLCK)以及凋亡因子Caspase-3表达。结果:LPS显著引起IEC-6细胞凋亡而参岺白术散的含药血清明显抑制细胞凋亡。与空白组比较,模型组IEC-6细胞跨膜电阻的TEER值显著下降(P<0.01);与LPS模型组比较,参苓白术散含药血清低、中、高剂量组IEC-6细胞跨膜电阻的TEER值显著升高,实验结果具有统计学意义(P<0.01)。LPS模型组的钙离子浓度明显高于空白组(P<0.01);不同浓度的参苓白术散含药血清组的钙离子浓度明显低于LPS模型组(P<0.01)。与空白组比较,模型组中磷酸化ROCKⅡ、MLCK蛋白表达明显升高(P<0.05);与模型组比较,不同剂量参苓白术散含药血清组中磷酸化ROCKⅡ、MLCK蛋白表达明显降低(P<0.05)。结论:参苓白术散含药血清对LPS诱导的IEC-6细胞损伤具有明显地抑制作用,与抑制细胞凋亡及IEC-6细胞通透性的改善有关。
文摘目的研究骆驼刺提取物(Alhagi pseudalhagi(M.B.)Desv.Extract,APE)对脂多糖诱导的大鼠小肠隐窝上皮细胞(Intestinal epithelial cell,IEC-6)损伤模型NLRP3炎症小体及相关细胞因子的影响。方法培养IEC-6细胞,将其分为空白组、模型组、APE低、中、高浓度组,用1.0μg/mL的脂多糖(Lipopolysaccharide,LPS)诱导建立细胞炎症损伤模型,APE(低、中、高浓度:15、25、35μg/mL)干预后采用CCK-8法检测细胞的存活率,通过ELISA试剂盒检测炎症因子IL-1β、IL-18、TNF-α的分泌水平。蛋白质印迹法(WB)检测核苷酸结合寡聚化结构域样受体蛋白3(Nucleotide-binding oligomerization domain-like receptor protein 3,NLRP3)炎症小体信号通路5个关键蛋白:NLRP3、半胱氨酸天冬氨酸蛋白酶1(Cystein-asparate protease-1,Caspase-l)、凋亡相关斑点样蛋白(Apoptosis-associated speck-like protein containing a CARD,ASC)及抗凋亡蛋白Bcl-2(Anti-apoptosis Protein Bcl-2)和Bcl-xl(Anti-apoptosis Protein Bcl-xl)表达。结果与空白组比较,模型组IEC-6细胞的存活率降低,NLRP3、Caspase-1、ASC蛋白表达水平升高,抗凋亡蛋白Bcl-2、Bcl-xl的表达水平降低,促炎因子IL-1β、IL-18和TNF-α的分泌水平升高,差异有统计学意义(P<0.05)。与模型组比较,APE低、中、高浓度组细胞存活率升高,35μg/mL APE组IEC-6细胞的NLRP3、Caspase-1、ASC蛋白相对表达水平降低,抗凋亡蛋白Bcl-2、Bcl-xl的表达水平升高,差异有统计学意义(P<0.05)。中、高浓度的APE能够抑制炎症因子分泌,25μg/mL APE对IL-1β、IL-18、TNF-α炎症因子分泌水平抑制率分别为31.60%、31.19%和31.09%(P<0.05)。结论骆驼刺提取物通过提高抗凋亡蛋白Bcl-2、Bcl-xl的表达水平,下调NLRP3炎症小体组成成分以及促炎因子IL-1β、IL-18和TNF-α分泌,从而抑制NLRP3炎症小体组装和激活,实现缓解LPS对IEC-6细胞的损伤。
