Potential of short chain fatty acids to modulate the induction of DNA damage and changes in the intracellular calcium concentration by oxidative stress in isolated rat distal colon cells
Potential of short chain fatty acids to modulate the induction of DNA damage and changes in the intracellular calcium concentration by oxidative stress in isolated rat distal colon cells
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DOI：
10.1093/carcin/20.4.629
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发表时间：
1999-04-01
期刊：
影响因子：
4.7
通讯作者：
Rechkemmer, G
中科院分区：
文献类型：
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作者：
Abrahamse, SL;Pool-Zobel, BL;Rechkemmer, G
短链脂肪酸(SCFA)被认为是肠道中有益的发酵产物，在未转化的结肠细胞中发挥营养作用，在结肠肿瘤细胞中减缓增殖和促进分化。我们进一步研究了SCFA对大鼠远端结肠细胞早期癌变、遗传毒性和细胞毒性的影响。用台盼蓝拒染法检测细胞毒性，用荧光分光光度计和钙敏感荧光染料Fura-2检测过氧化氢引起的细胞内钙离子浓度([Ca~(2+)](I))的变化，用微凝胶电泳法(彗星试验)检测DNA氧化损伤。分别用100-500 mU/M和6.25 mM/mM的SCFA处理新鲜分离的结肠细胞，发现100-500 mU/M的SCFA可引起细胞内[Ca~(2+)]_(I)的快速升高，之后[Ca~(2+)]_(I)逐渐升高，SCFA的加入不影响[Ca~(2+)](I)，也不能降低H_2O_2诱导的细胞内[Ca~(2+)](I)的增加，丁酸盐和醋酸盐分别能降低100、200和500 mU/M的H_2O_2引起的DNA损伤。相比之下，异丁酸盐和丙酸盐无效。两种保护性SCFA对DNA损伤的减轻程度相似，分别以41：21：38或75：15：10的比例含有醋酸盐、丙酸和丁酸的生理混合物，预计在抗性淀粉和果胶发酵后出现在结肠中，没有显示出显著的抗遗传毒性作用。丁酸盐和乙酸酯与异丁酸酯和丙酸的主要区别在于前者作为能量来源被结肠细胞利用得最好。因此，我们在抗遗传毒性方面的结果，再加上对[Ca~(2+)](I)稳态的研究结果表明，能量系统上的分子效应使这些未转化的、新分离的结肠细胞对H_2O_2不太敏感。
Short chain fatty acids (SCFA) are considered to be beneficial fermentation products in the gut by exerting trophic effects in non-transformed colon cells and by slowing proliferation and enhancing differentiation in colonic tumour cells. We have studied the further effects of SCFA on cellular events of early carcinogenesis, genotoxicity and cytotoxicity in rat distal colon cells. Cytotoxicity was assessed by measuring trypan blue exclusion and by determining the H2O2-induced changes in intracellular calcium concentration ([Ca2+](i)) using a fluorospectrophotometer and the calcium-sensitive fluorescent dye Fura-2, The microgel electrophoresis technique (COMET assay) was used to assess oxidative DNA damage. Individual SCFA and physiological SCFA mixtures were investigated for their potential to prevent DNA and cell damage induced by H2O2, For this, freshly isolated colon cells were treated with H2O2 (100-500 mu M) and 6.25 mM SCFA, We have found 100-500 mu M H2O2 to cause a fast initial increase in [Ca2+](i), whereafter the levels gradually further increased, Addition of SCFA did not affect [Ca2+](i) nor did it reduce the H2O2-induced increase in [Ca2+](i), Butyrate and acetate were able to reduce the induction of DNA damage by 100, 200 and 500 mu M H2O2, respectively. In contrast, i-butyrate and propionate were ineffective. The degree of reduction of DNA damage for the two protective SCFA was similar, Physiological mixtures containing acetate, propionate and butyrate in ratios of 41:21:38 or 75:15:10 that are expected to arise in the colon after fermentation of resistant starches and pectin, respectively, did not show significant antigenotoxic effects. The major difference between butyrate and acetate, on one hand, and i-butyrate and propionate, on the other hand, is that the former compounds are utilized best as energy sources by the colon cells. Therefore, our results on antigenotoxicity coupled with the findings on [Ca2+](i) homeostasis indicate that molecular effects on the energy system render these non-transformed, freshly isolated colon cells to be less susceptible to H2O2.