Ogata Miyuki, Van Hung Tran, Tari Hiroyuki, Arakawa Teruaki, Suzuki Takuya
Department of Biofunctional Science and Technology, Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, 739-8528, Japan.
Bizen Chemical Co. Ltd. 363 Tokutomi, Akaiwa City, Okayama, Japan.
Nutr Res. 2017 Mar;39:25-33. doi: 10.1016/j.nutres.2017.02.002. Epub 2017 Feb 7.
Heat shock proteins (HSPs) protect intestinal epithelial cell function, integrity and viability against many forms of stress. We hypothesized that dietary fibers (DFs) in the diet may increase HSP expression, since DFs are known to exhibit beneficial effects on intestinal health. The present study investigated the regulation of intestinal HSP expression by DFs, particularly psyllium fiber. Feeding psyllium fiber for 5 d increased HSP25 expression, but not HSP32 and HSP70 expression in the jejunum, ileum, and colon of mice at both the protein and mRNA levels. The increases in HSP25 expression did not correlate with cecal organic acid production by microbial fermentation. The water-insoluble fraction of psyllium fiber largely contributed to the induction of HSP25 expression, but feeding with other water-insoluble DFs from beet, wheat, and oats failed to induce intestinal HSP25 expression. Although the water-holding capacity of psyllium fiber was much higher than those of the other water-insoluble DFs examined, the increase in HSP25 expression induced by feeding polycarbophil, which possesses a high water-holding capacity similar to that of psyllium fiber, was much lower than that induced by psyllium fiber. Finally, induction of malondialdehyde production by hydrogen peroxide, an oxidant, in the colon of mice fed psyllium fiber was lower than that in mice fed with the control diets. Taken together, feeding psyllium fiber, especially the water-insoluble fraction, increases intestinal HSP25 expression and suppresses oxidant-induced malondialdehyde production.
热休克蛋白（HSPs）可保护肠上皮细胞功能、完整性及活力免受多种应激形式的影响。我们推测饮食中的膳食纤维（DFs）可能会增加热休克蛋白的表达，因为已知膳食纤维对肠道健康具有有益作用。本研究调查了膳食纤维，特别是车前子纤维对肠道热休克蛋白表达的调节作用。给小鼠喂食车前子纤维5天，可使空肠、回肠和结肠中热休克蛋白25（HSP25）的表达在蛋白质和mRNA水平均增加，但热休克蛋白32（HSP32）和热休克蛋白70（HSP70）的表达未增加。HSP25表达的增加与微生物发酵产生的盲肠有机酸无关。车前子纤维的水不溶性部分在很大程度上促成了HSP25表达的诱导，但喂食甜菜、小麦和燕麦中的其他水不溶性膳食纤维未能诱导肠道HSP25表达。尽管车前子纤维的持水能力远高于所检测的其他水不溶性膳食纤维，但喂食聚卡波非（其持水能力与车前子纤维相似）所诱导的HSP25表达增加远低于车前子纤维所诱导的增加。最后，在喂食车前子纤维的小鼠结肠中，氧化剂过氧化氢诱导的丙二醛生成低于喂食对照饮食的小鼠。综上所述，喂食车前子纤维，尤其是水不溶性部分，可增加肠道HSP25表达并抑制氧化剂诱导的丙二醛生成。
