Project description:SIRT6 has been implicated in anti-aging at the organismal level; however, its role in pancreatic beta cell aging is unclear. This study investigated the role of SIRT6 in pancreatic beta cell aging using conditional SIRT6 transgenic overexpression mice at 10 and 16 months of age. Our data show that SIRT6 has a strong protective function against aging-associated oxidative stress, DNA damage, and multiple forms of cell death.
Project description:The SIRT6 deacetylase has been implicated in DNA repair, telomere maintenance, glucose and lipid metabolism and, importantly, it has critical roles in the brain ranging from its development to neurodegeneration. Here, we combined transcriptomics and metabolomics approaches to characterize the functions of SIRT6 in mouse brains. Unexpectedly, our analysis reveals that SIRT6 is a central regulator of mitochondrial activity in the brain. SIRT6 deficiency in the brain leads to mitochondrial deficiency with a global downregulation of mitochondria-related genes and pronounced changes in metabolite content. We suggest that SIRT6 affects mitochondrial functions through its interaction with the transcription factor YY1 that, together, regulate mitochondrial gene expression. Moreover, SIRT6 target genes include SIRT3 and SIRT4, which are significantly downregulated in SIRT6-deficient brains. Our results demonstrate that the lack of SIRT6 leads to decreased mitochondrial gene expression and metabolomic changes of TCA cycle byproducts, including increased ROS production, reduced mitochondrial number, and impaired membrane potential that can be partially rescued by restoring SIRT3 and 4 levels. Importantly, the changes we observed in SIRT6 deficient brains are also occurring in aging human brains and particularly in patients with Alzheimer's, Parkinson's, Huntington's, and Amyotrophic lateral sclerosis disease. Overall, our results suggest that the reduced levels of SIRT6 in the aging brain and neurodegeneration initiate mitochondrial dysfunction by altering gene expression, ROS production and mitochondrial decay.
Project description:Aging is associated with detrimental changes in chromatin structure and gene expression, contributing to inflammation, metabolic decline and tissue dysfunction. SIRT6, a histone deacetylase, plays a key role in maintaining chromatin integrity and promoting longevity. Here, we show that aging leads to increased chromatin accessibility in the murine liver, accompanied by upregulation of inflammation and downregulation of metabolic pathways. Remarkably, SIRT6 overexpression reversed these changes, reducing inflammation and enhancing metabolic function. Notably, ETS family members were enriched in regions with increased accessibility during aging, while liver-enriched transcription factors (LETFs) were enriched in regions with reduced accessibility. ChIP-seq analyses of H3K9ac and H3K56ac binding showed that H3K9ac, but not H3K56ac, is associated with increased accessibility during aging, and that SIRT6 can reverse this effect. Furthermore, AAV-mediated SIRT6 overexpression in aged mice demonstrated that SIRT6 not only slows age-related chromatin changes but can also reverse them, rejuvenating chromatin accessibility to a youthful state.
Project description:Aging is associated with detrimental changes in chromatin structure and gene expression, contributing to inflammation, metabolic decline and tissue dysfunction. SIRT6, a histone deacetylase, plays a key role in maintaining chromatin integrity and promoting longevity. Here, we show that aging leads to increased chromatin accessibility in the murine liver, accompanied by upregulation of inflammation and downregulation of metabolic pathways. Remarkably, SIRT6 overexpression reversed these changes, reducing inflammation and enhancing metabolic function. Notably, ETS family members were enriched in regions with increased accessibility during aging, while liver-enriched transcription factors (LETFs) were enriched in regions with reduced accessibility. ChIP-seq analyses of H3K9ac and H3K56ac binding showed that H3K9ac, but not H3K56ac, is associated with increased accessibility during aging, and that SIRT6 can reverse this effect. Furthermore, AAV-mediated SIRT6 overexpression in aged mice demonstrated that SIRT6 not only slows age-related chromatin changes but can also reverse them, rejuvenating chromatin accessibility to a youthful state.
Project description:Aging is associated with detrimental changes in chromatin structure and gene expression, contributing to inflammation, metabolic decline and tissue dysfunction. SIRT6, a histone deacetylase, plays a key role in maintaining chromatin integrity and promoting longevity. Here, we show that aging leads to increased chromatin accessibility in the murine liver, accompanied by upregulation of inflammation and downregulation of metabolic pathways. Remarkably, SIRT6 overexpression reversed these changes, reducing inflammation and enhancing metabolic function. Notably, ETS family members were enriched in regions with increased accessibility during aging, while liver-enriched transcription factors (LETFs) were enriched in regions with reduced accessibility. ChIP-seq analyses of H3K9ac and H3K56ac binding showed that H3K9ac, but not H3K56ac, is associated with increased accessibility during aging, and that SIRT6 can reverse this effect. Furthermore, AAV-mediated SIRT6 overexpression in aged mice demonstrated that SIRT6 not only slows age-related chromatin changes but can also reverse them, rejuvenating chromatin accessibility to a youthful state.
Project description:Aging is associated with detrimental changes in chromatin structure and gene expression, contributing to inflammation, metabolic decline and tissue dysfunction. SIRT6, a histone deacetylase, plays a key role in maintaining chromatin integrity and promoting longevity. Here, we show that aging leads to increased chromatin accessibility in the murine liver, accompanied by upregulation of inflammation and downregulation of metabolic pathways. Remarkably, SIRT6 overexpression reversed these changes, reducing inflammation and enhancing metabolic function. Notably, ETS family members were enriched in regions with increased accessibility during aging, while liver-enriched transcription factors (LETFs) were enriched in regions with reduced accessibility. ChIP-seq analyses of H3K9ac and H3K56ac binding showed that H3K9ac, but not H3K56ac, is associated with increased accessibility during aging, and that SIRT6 can reverse this effect. Furthermore, AAV-mediated SIRT6 overexpression in aged mice demonstrated that SIRT6 not only slows age-related chromatin changes but can also reverse them, rejuvenating chromatin accessibility to a youthful state.
Project description:Aging is associated with detrimental changes in chromatin structure and gene expression, contributing to inflammation, metabolic decline and tissue dysfunction. SIRT6, a histone deacetylase, plays a key role in maintaining chromatin integrity and promoting longevity. Here, we show that aging leads to increased chromatin accessibility in the murine liver, accompanied by upregulation of inflammation and downregulation of metabolic pathways. Remarkably, SIRT6 overexpression reversed these changes, reducing inflammation and enhancing metabolic function. Notably, ETS family members were enriched in regions with increased accessibility during aging, while liver-enriched transcription factors (LETFs) were enriched in regions with reduced accessibility. ChIP-seq analyses of H3K9ac and H3K56ac binding showed that H3K9ac, but not H3K56ac, is associated with increased accessibility during aging, and that SIRT6 can reverse this effect. Furthermore, AAV-mediated SIRT6 overexpression in aged mice demonstrated that SIRT6 not only slows age-related chromatin changes but can also reverse them, rejuvenating chromatin accessibility to a youthful state.
Project description:Sirtuins (Sirt) are a family of enzymes that modify chromatin and other proteins to affect gene activity. Loss of Sirt6 leads to a progeria-like phenotype in mice, but the target of SIRT6 action has been elusive. Here we show that Sirt6 binds to thousands of gene promoters in a stress-inducible fashion, guided by the stress-responsive transcription factor NF-κB. Chromatin profiling by ChIP-chip analysis of Sirt6 and NF-KB component RelA combined with expression array data of wildtype, Sirt6 knockout and Sirt6 RelA double knockout cells demonstrates that RelA recruits Sirt6 to NF-KB targets in response to TNF-a induction and that many of these targets are important for senescence and aging. comparison of wild type, Sirt6-/- and Sirt6-/- RelA-/- MEF cells