UMMS Affiliation

Program in Gene Function and Expression; RNA Therapeutics Institute; Program in Systems Biology; Program in Molecular Medicine

Date

4-23-2014

Document Type

Article

Disciplines

Biochemistry | Cellular and Molecular Physiology | Genetics and Genomics | Molecular Biology | Molecular genetics

Abstract

BACKGROUND: Insulin/IGF-1 signaling plays a central role in longevity across phylogeny. In C. elegans, the forkhead box O (FOXO) transcription factor, DAF-16, is the primary target of insulin/IGF-1 signaling, and multiple isoforms of DAF-16 (a, b, and d/f) modulate lifespan, metabolism, dauer formation, and stress resistance. Thus far, across phylogeny modulation of mammalian FOXOs and DAF-16 have focused on post-translational regulation with little focus on transcriptional regulation. In C. elegans, we have previously shown that DAF-16d/f cooperates with DAF-16a to promote longevity. In this study, we generated transgenic strains expressing near-endogenous levels of either daf-16a or daf-16d/f, and examined temporal expression of the isoforms to further define how these isoforms contribute to lifespan regulation. RESULTS: Here, we show that DAF-16a is sensitive both to changes in gene dosage and to alterations in the level of insulin/IGF-1 signaling. Interestingly, we find that as worms age, the intestinal expression of daf-16d/f but not daf-16a is dramatically upregulated at the level of transcription. Preventing this transcriptional upregulation shortens lifespan, indicating that transcriptional regulation of daf-16d/f promotes longevity. In an RNAi screen of transcriptional regulators, we identify elt-2 (GATA transcription factor) and swsn-1 (core subunit of SWI/SNF complex) as key modulators of daf-16d/f gene expression. ELT-2 and another GATA factor, ELT-4, promote longevity via both DAF-16a and DAF-16d/f while the components of SWI/SNF complex promote longevity specifically via DAF-16d/f. CONCLUSIONS: Our findings indicate that transcriptional control of C. elegans FOXO/daf-16 is an essential regulatory event. Considering the conservation of FOXO across species, our findings identify a new layer of FOXO regulation as a potential determinant of mammalian longevity and age-related diseases such as cancer and diabetes.

Rights and Permissions

Citation: Bansal A, Kwon ES, Conte D Jr, Liu H, Gilchrist MJ, MacNeil LT, Tissenbaum HA. Transcriptional regulation of Caenorhabditis elegans FOXO/DAF-16 modulates lifespan. Longev Healthspan. 2014 Apr 23;3:5. doi: 10.1186/2046-2395-3-5. Link to article on publisher's site

Comments

Copyright 2014 Bansal et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

First author Ankita Bansal is a doctoral student in the Interdisciplinary Graduate Program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.

Related Resources

Link to Article in PubMed

Keywords

Aging, C. elegans, DAF-16/FOXO, Isoforms, Longevity, Transcription