Muraoka Sanae, Nitta Yuuki, Yamada Taiki, Sakuma Yuusuke, Ichimura Aoi, Sakurai Koichi
Department of Life Science, Hokkaido Pharmaceutical University School of Pharmacy.
Yakugaku Zasshi. 2017;137(9):1137-1145. doi: 10.1248/yakushi.17-00018.
Cells have developed ingenious defense mechanisms in response to oxidative stress. Here, we evaluated changes in anti-oxidative capacity during differentiation of 3T3-L1 preadipocytes into adipocytes. When 3T3-L1 preadipocytes were treated with HO (0.10-2.0 mM) for 21 h, cell viability decreased in response to HO concentration, with an LD of approximately 0.35 mM HO. In the cells undergoing differentiation at 2 and 6 d, LD increased to 1.0 and >2.0 mM HO, respectively. These results indicate that resistance to oxidative stress dramatically increased with progression of differentiation of preadipocytes into adipocytes. Catalase activity and GSH content increased in the differentiated cells at 6 d, whereas superoxide dismutase and glutathione peroxidase activities were slightly lower in adipocytes than in preadipocytes. Moreover, knockdown of catalase or depletion of intracellular GSH enhanced the sensitivity to HO. When GSH was added to the cells depleted of intracellular GSH, the antioxidant capacity recovered. Autophagy was increased in differentiated adipocytes but was not affected by HO treatment. Therefore, these results suggest that the increase in intracellular catalase activity and GSH content played a role in the increased anti-oxidative capacity of differentiated 3T3-L1 adipocytes.
细胞已经发展出巧妙的防御机制来应对氧化应激。在此，我们评估了3T3-L1前脂肪细胞分化为脂肪细胞过程中抗氧化能力的变化。当用HO（0.10 - 2.0 mM）处理3T3-L1前脂肪细胞21小时时，细胞活力随HO浓度降低，HO的半数致死剂量约为0.35 mM。在分化2天和6天的细胞中，半数致死剂量分别增加到1.0 mM和>2.0 mM HO。这些结果表明，随着前脂肪细胞向脂肪细胞分化的进行，对氧化应激的抗性显著增加。过氧化氢酶活性和谷胱甘肽含量在分化6天的细胞中增加，而超氧化物歧化酶和谷胱甘肽过氧化物酶活性在脂肪细胞中略低于前脂肪细胞。此外，过氧化氢酶的敲低或细胞内谷胱甘肽的耗尽增强了对HO的敏感性。当向细胞内谷胱甘肽耗尽的细胞中添加谷胱甘肽时，抗氧化能力得以恢复。自噬在分化的脂肪细胞中增加，但不受HO处理的影响。因此，这些结果表明细胞内过氧化氢酶活性和谷胱甘肽含量的增加在分化的3T3-L1脂肪细胞抗氧化能力增强中发挥了作用。
