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The RNA-binding protein LIN-28 was first found to control developmental timing in Caenorhabditis elegans. Later, it was found to play important roles in pluripotency, metabolism, and cancer in mammals. Here we report that a low dosage of lin-28 enhanced stress tolerance and longevity, and reduced germline stem/progenitor cell number in C. elegans. The germline LIN-28-regulated microRNA let-7 was required for these effects by targeting akt-1/2 and decreasing their protein levels. AKT-1/2 and the downstream DAF-16 transcription factor were both required for the lifespan and germline stem cell effects of lin-28. The pathway also mediated dietary restriction induced lifespan extension and reduction in germline stem cell number. Thus, the LIN-28/let-7/AKT/DAF-16 axis we delineated here is a program that plays an important role in balancing reproduction and somatic maintenance and their response to the environmental energy level-a central dogma of the 'evolutionary optimization' of resource allocation that modulates aging., (© 2016 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.)

The RNA-binding protein LIN-28 was first found to control developmental timing in Caenorhabditis elegans. Later, it was found to play important roles in pluripotency, metabolism, and cancer in mammals. Here we report that a low dosage of lin-28 enhanced stress tolerance and longevity, and reduced germline stem/progenitor cell number in C. elegans. The germline LIN-28 -regulated microRNA let-7 was required for these effects by targeting akt-1/2 and decreasing their protein levels. AKT-1/2 and the downstream DAF-16 transcription factor were both required for the lifespan and germline stem cell effects of lin-28. The pathway also mediated dietary restriction induced lifespan extension and reduction in germline stem cell number. Thus, the LIN-28/let-7/AKT/DAF-16 axis we delineated here is a program that plays an important role in balancing reproduction and somatic maintenance and their response to the environmental energy level-a central dogma of the 'evolutionary optimization' of resource allocation that modulates aging. [ABSTRACT FROM AUTHOR]

Aging is characterized by the loss of homeostasis and the general decline of physiological functions, accompanied by various degenerative diseases and increased rates of mortality. Aging targeting small molecule screens have been performed many times, however, few have focused on endogenous metabolic intermediates—metabolites. Here, using C. elegans lifespan assays, we conducted a worm metabolite screen and identified an eukaryotes conserved metabolite, myo-inositol (MI), to extend lifespan, increase mobility and reduce fat content. Genetic analysis of enzymes in MI metabolic pathway suggest that MI alleviates aging through its derivative PI(4,5)P2. MI and PI(4,5)P2 are precursors of PI(3,4,5)P3, which is negatively related to longevity. The longevity effect of MI is dependent on the tumor suppressor gene, daf-18 (homologous to mouse Pten), independent of its classical pathway downstream genes, akt or daf-16. Furthermore, we found MI effects on aging and lifespan act through mitophagy regulator PTEN induced kinase-1 (pink-1) and mitophagy. MI's anti-aging effect is also conserved in mouse, indicating a conserved mechanism in mammals. Phosphatidylinositol 3-kinase catalyzes the reaction from PI(4,5)P2 to PI(3,4,5)P3 and is encoded by the age-1 gene known to regulate lifespan. Here the researchers found that the metabolite myo-inositol, which can be converted to PI(3,4,5)P3 extends worm lifespan and alleviates worm as well as mouse health decline during aging. [ABSTRACT FROM AUTHOR]