Control of transcriptional programs of aging by NF-kappaB

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Abstract/Contents

Abstract
Aging is a degenerative process accompanied by tissue deterioration, decline in function and increased susceptibility to disease. It is now understood to be a genetically and environmentally regulated process, rather than simply the result of wear and tear. We developed a systematic approach to identify combinatorial cis-regulatory motifs that drive age-dependent gene expression across different tissues and organisms, and identified the transcription factor NF-[kappa]B as a candidate regulator of aging. Using multiple independent models, we show a role for NF-[kappa]B in regulating transcriptional programs of aging. First, we found that aged mice subjected to NF-[kappa]B blockade for two weeks exhibit reversion of the tissue characteristics and global gene expression programs to those of young mice. Next, we detected deregulated transcriptional activity of NF-[kappa]B in Sirt6-deficient mice, which exhibit premature aging-like symptoms. We show that Sirt6 interacts with the NF-[kappa]B RelA subunit and deacetylates histone H3 lysine 9 (H3K9) at NF-[kappa]B target gene promoters. Computational genomics analyses revealed increased activity of NF-[kappa]B-driven gene expression programs in multiple Sirt6-deficient tissues in vivo. Moreover, haploinsufficiency of RelA rescues the early lethality and degenerative syndrome of Sirt6-deficient mice, suggesting that hyperactive NF-[kappa]B-dependent transcription in the absence of Sirt6 promotes premature aging-like syndromes. Finally, we performed a genome-scale survey of RelA and Sirt6 location on chromatin in mouse embryonic fibroblasts (MEFs) via chromatin immunoprecipiation (ChIP)-on-chip to understand to what extent Sirt6 and RelA act coordinately to regulate gene expression. These results indicate that RelA and Sirt6 co-occupy the promoters of a large population of genes at sites less than 500kb apart and/or require RelA to enable binding of Sirt6. Expression analysis of these shared targets reveals direct regulation of 301 promoters, including genes such as Shc1 (encoding p66), Cdkn2a (encoding p16), Wnt2 and Jmjd3, which have been separately implicated in the aging process. We propose that hyperactive NF-[kappa]B signaling contributes to premature and normal aging.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2010
Issuance monographic
Language English

Creators/Contributors

Associated with Kawahara, Tiara Lynn Aiko
Associated with Stanford University, Department of Cancer Biology.
Primary advisor Chang, Howard Y. (Howard Yuan-Hao), 1972-
Thesis advisor Chang, Howard Y. (Howard Yuan-Hao), 1972-
Thesis advisor Chua, Katrin Faye
Thesis advisor Khavari, Paul A
Thesis advisor Sweet-Cordero, Eric
Advisor Chua, Katrin Faye
Advisor Khavari, Paul A
Advisor Sweet-Cordero, Eric

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Tiara Lynn Aiko Kawahara.
Note Submitted to the Department of Cancer Biology.
Thesis Ph.D. Stanford University 2010
Location electronic resource

Access conditions

Copyright
© 2010 by Tiara Lynn Aiko Kawahara
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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