BACKGROUND: Obesity is a major health burden. Preadipocytes proliferate and differentiate in mature adipocytes in the adipogenic process, which could be a potential therapeutic approach for obesity. Deficiency of SIRT6, a stress-responsive protein deacetylase and mono-ADP ribosyltransferase enzyme, blocks adipogenesis. Mutants of SIRT6 (N308K/A313S) were recently linked to the in the long lifespan Ashkenazi Jews. In this study, we aimed to clarify how these new centenarian-associated SIRT6 genetic variants affect adipogenesis at the transcriptional and epigenetic level. METHODS: We analyzed the role of SIRT6 wild-type (WT) or SIRT6 centenarian-associated mutant (N308K/A313S) overexpression in adipogenesis, by creating stably transduced preadipocyte cell lines using lentivirus on the 3T3-L1 model. Histone post-translational modifications (PTM: acetylation, methylation) and transcriptomic changes were analyzed by mass spectrometry (LC-MS/MS) and RNA-Seq, respectively, in 3T3-L1 adipocytes. In addition, the adipogenic process and related signaling pathways were investigated by bioinformatics and biochemical approaches. RESULTS: Overexpression of centenarian-associated SIRT6 mutant increased adipogenic differentiation to a similar extent compared to the WT form. However, it triggered distinct histone PTM profiles in mature adipocytes, with significantly higher acetylation levels, and activated divergent transcriptional programs, including those dependent on signaling related to the sympathetic innervation and to PI3K pathway. 3T3-L1 mature adipocytes overexpressing SIRT6 N308K/A313S displayed increased insulin sensitivity in a neuropeptide Y (NPY)-dependent manner. CONCLUSIONS: SIRT6 N308K/A313S overexpression in mature adipocytes ameliorated glucose sensitivity and impacted sympathetic innervation signaling. These findings highlight the importance of targeting SIRT6 enzymatic activities to regulate the co-morbidities associated with obesity.
- MeSH
- Adipogenesis * genetics MeSH
- 3T3-L1 Cells * MeSH
- Epigenesis, Genetic * genetics MeSH
- Histones metabolism genetics MeSH
- Humans MeSH
- Mutation MeSH
- Mice MeSH
- Obesity genetics metabolism MeSH
- Protein Processing, Post-Translational genetics MeSH
- Sirtuins * genetics metabolism MeSH
- Adipocytes * metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Studies over the past 30 years have revealed that adipose tissue is the major endocrine and paracrine organ of the human body. Arguably, adiopobiology has taken its reasonable place in studying obesity and related cardiometabolic diseases (CMDs), including Alzheimer's disease (AD), which is viewed herein as a neurometabolic disorder. The pathogenesis and therapy of these diseases are multiplex at basic, clinical and translational levels. Our present goal is to describe new developments in cardiometabolic and neurometabolic adipobiology. Accordingly, we focus on adipose- and/or skeletal muscle-derived signaling proteins (adipsin, adiponectin, nerve growth factor, brain-derived neuroptrophic factor, neurotrophin-3, irisin, sirtuins, Klotho, neprilysin, follistatin-like protein-1, meteorin-like (metrnl), as well as growth differentiation factor 11) as examples of metabotrophic factors (MTFs) implicated in the pathogenesis and therapy of obesity and related CMDs. We argue that these pathologies are MTF-deficient diseases. In 1993 the "vascular hypothesis of AD" was published and in the present review we propose the "vasculometabolic hypothesis of AD." We discuss how MTFs could bridge CMDs and neurodegenerative diseases, such as AD. Greater insights on how to manage the MTF network would provide benefits to the quality of human life.
- MeSH
- Adipokines metabolism MeSH
- Molecular Targeted Therapy methods MeSH
- Humans MeSH
- Metabolic Syndrome drug therapy metabolism MeSH
- Neurodegenerative Diseases drug therapy metabolism MeSH
- Neuropeptides metabolism MeSH
- Nerve Growth Factors metabolism MeSH
- Signal Transduction MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH