Hwang Chae Young, Han Ying-Hao, Lee Seung-Min, Cho Sang-Mi, Yu Dae-Yeul, Kwon Ki-Sun
Aging Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea.
GHBIO Inc., Daejeon, Korea.
Ann Geriatr Med Res. 2020 Dec;24(4):297-304. doi: 10.4235/agmr.20.0051. Epub 2020 Nov 24.
Sestrin2 (Sesn2) is involved in the maintenance of metabolic homeostasis and aging via modulation of the 5' AMP-activated protein kinase-mammalian target of rapamycin (AMPK-mTOR) pathway.
Wild-type and Sesn2 knockout (KO) mice of the 129/SvJ background were maintained in a pathogen-free authorized facility under a 12-hour dark/light cycle at 20°C-22°C and 50%-60% humidity. Mouse embryonic fibroblasts (MEFs) were prepared from 13.5-day-old embryos derived from Sesn2-KO mice mated with each other.
The MEFs from Sesn2-KO mice showed enlarged and flattened morphologies and senescence-associated β-galactosidase activity, accompanied by an elevated level of reactive oxygen species. These senescence phenotypes recovered following treatment with N-acetyl-cysteine. Notably, the mRNA levels of NADPH oxidase 4 (NOX4) and transforming growth factor (TGF)-β were markedly increased in Sesn2-KO MEFs. Treatment of Sesn2-KO MEFs with the NOX inhibitor diphenyleneiodonium and the TGF-β inhibitor SB431542 restored cell growth inhibited by Sesn2-KO.
Sesn2 attenuates cellular senescence via suppression of TGF-β- and NOX4-induced reactive oxygen species generation and subsequent inhibition of AMPK.
sestrin2（Sesn2）通过调节5'-AMP激活蛋白激酶-雷帕霉素哺乳动物靶标（AMPK-mTOR）途径参与维持代谢稳态和衰老过程。
将129/SvJ背景的野生型和Sesn2基因敲除（KO）小鼠饲养在无病原体的授权设施中，温度为20°C - 22°C，湿度为50% - 60%，光照周期为12小时黑暗/12小时光照。小鼠胚胎成纤维细胞（MEF）取自相互交配的Sesn2-KO小鼠的13.5天龄胚胎。
Sesn2-KO小鼠的MEF呈现出增大且扁平的形态以及衰老相关的β-半乳糖苷酶活性，同时活性氧水平升高。用N-乙酰半胱氨酸处理后，这些衰老表型得以恢复。值得注意的是，Sesn2-KO的MEF中NADPH氧化酶4（NOX4）和转化生长因子（TGF）-β的mRNA水平显著升高。用NOX抑制剂二苯基碘鎓和TGF-β抑制剂SB431542处理Sesn2-KO的MEF可恢复被Sesn2-KO抑制的细胞生长。
Sesn2通过抑制TGF-β和NOX4诱导的活性氧生成以及随后对AMPK的抑制来减轻细胞衰老。
