1. Intestine-specific removal of DAF-2 nearly doubles lifespan in Caenorhabditis elegans with little fitness cost
- Author
-
Yan-Ping Zhang, Wen-Hong Zhang, Pan Zhang, Qi Li, Yue Sun, Jia-Wen Wang, Shaobing O. Zhang, Tao Cai, Cheng Zhan, and Meng-Qiu Dong
- Subjects
Multidisciplinary ,Longevity ,General Physics and Astronomy ,Forkhead Transcription Factors ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology ,Receptor, Insulin ,Receptor, IGF Type 1 ,Intestines ,Mutation ,Animals ,Insulin ,RNA ,Insulin-Like Growth Factor I ,Caenorhabditis elegans ,Caenorhabditis elegans Proteins - Abstract
Twenty-nine years following the breakthrough discovery that a single-gene mutation of daf-2 doubles Caenorhabditis elegans lifespan, it remains unclear where this insulin/IGF-1 receptor gene is expressed and where it acts to regulate ageing. Using knock-in fluorescent reporters, we determined that daf-2 and its downstream transcription factor daf-16 are expressed ubiquitously. Using tissue-specific targeted protein degradation, we determined that intracellular DAF-2-to-DAF-16 signaling in the intestine plays a major role in lifespan regulation, while that in the hypodermis, neurons, and germline plays a minor role. Notably, intestine-specific loss of DAF-2 activates DAF-16 in and outside the intestine, causes almost no adverse effects on development and reproduction, and extends lifespan by 94% in a way that partly requires non-intestinal DAF-16. Consistent with intestine supplying nutrients to the entire body, evidence from this and other studies suggests that altered metabolism, particularly down-regulation of protein and RNA synthesis, mediates longevity by reduction of insulin/IGF-1 signaling.
- Published
- 2021