1
|
Bhattacharya S, Tu BP. Histone acylation at a glance. J Cell Sci 2024; 137:jcs261250. [PMID: 38842578 PMCID: PMC11213524 DOI: 10.1242/jcs.261250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024] Open
Abstract
An important mechanism of gene expression regulation is the epigenetic modification of histones. The cofactors and substrates for these modifications are often intermediary metabolites, and it is becoming increasingly clear that the metabolic and nutritional state of cells can influence these marks. These connections between the balance of metabolites, histone modifications and downstream transcriptional changes comprise a metabolic signaling program that can enable cells to adapt to changes in nutrient availability. Beyond acetylation, there is evidence now that histones can be modified by other acyl groups. In this Cell Science at a Glance article and the accompanying poster, we focus on these histone acylation modifications and provide an overview of the players that govern these acylations and their connections with metabolism.
Collapse
Affiliation(s)
- Saikat Bhattacharya
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390-9038, USA
| | - Benjamin P. Tu
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390-9038, USA
| |
Collapse
|
2
|
Giuliani G, Longo VD. Ketone bodies in cell physiology and cancer. Am J Physiol Cell Physiol 2024; 326:C948-C963. [PMID: 38189128 DOI: 10.1152/ajpcell.00441.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 01/09/2024]
Abstract
Ketogenic diets (KDs), fasting, or prolonged physical activity elevate serum ketone bodies (KBs) levels, providing an alternative fuel source for the brain and other organs. However, KBs play pleiotropic roles that go beyond their role in energy production. KBs can act as signaling metabolites, influence gene expression, proteins' posttranslational modifications (PTMs), inflammation, and oxidative stress. Here, we explore the impact of KBs on mammalian cell physiology, including aging and tissue regeneration. We also concentrate on KBs and cancer, given the extensive evidence that dietary approaches inducing ketosis, including fasting-mimicking diets (FMDs) and KDs, can prevent cancer and affect tumor progression.
Collapse
Affiliation(s)
- Giacomo Giuliani
- Longevity Institute and Davis School of Gerontology, University of Southern California, Los Angeles, California, United States
| | - Valter D Longo
- Longevity Institute and Davis School of Gerontology, University of Southern California, Los Angeles, California, United States
- IFOM, FIRC Institute of Molecular Oncology, Milan, Italy
| |
Collapse
|
3
|
Gonzatti MB, Goldberg EL. Ketone bodies as chemical signals for the immune system. Am J Physiol Cell Physiol 2024; 326:C707-C711. [PMID: 38189135 PMCID: PMC11193451 DOI: 10.1152/ajpcell.00478.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 01/09/2024]
Abstract
Ketone bodies are short-chain fatty acids produced by the liver during periods of limited glucose availability, such as during fasting or low carbohydrate feeding. Recent studies have highlighted important nonmetabolic functions of the most abundant ketone body, β-hydroxybutyrate (BHB). Notably, many of these functions, including limiting specific sources of inflammation, histone deacetylase inhibition, NFκB inhibition, and GPCR stimulation, are particularly important to consider in immune cells. Likewise, dietary manipulations like caloric restriction or ketogenic diet feeding have been associated with lowered inflammation, improved health outcomes, and improved host defense against infection. However, the underlying mechanisms of the broad benefits of ketosis remain incompletely understood. In this Perspective, we contextualize the current state of the field of nonmetabolic functions of ketone bodies specifically in the immune system and speculate on the molecular explanations and broader physiological significance.
Collapse
Affiliation(s)
- Michelangelo B Gonzatti
- Department of Physiology, University of California, San Francisco, California, United States
| | - Emily L Goldberg
- Department of Physiology, University of California, San Francisco, California, United States
| |
Collapse
|
4
|
Nomura M, Murad NF, Madhavan SS, Eap B, Garcia TY, Aguirre CG, Verdin E, Ellerby L, Furman D, Newman JC. A ketogenic diet reduces age-induced chronic neuroinflammation in mice Running title: ketogenic diet and brain inflammaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.01.569598. [PMID: 38106160 PMCID: PMC10723274 DOI: 10.1101/2023.12.01.569598] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Beta-hydroxybutyrate (BHB) is a ketone body synthesized during fasting or strenuous exercise. Our previous study demonstrated that a cyclic ketogenic diet (KD), which induces BHB levels similar to fasting every other week, reduces midlife mortality and improves memory in aging mice. BHB actively regulates gene expression and inflammatory activation through non-energetic signaling pathways. Neither of these activities has been well-characterized in the brain and they may represent mechanisms by which BHB affects brain function during aging. First, we analyzed hepatic gene expression in an aging KD-treated mouse cohort using bulk RNA-seq. In addition to the downregulation of TOR pathway activity, cyclic KD reduces inflammatory gene expression in the liver. We observed via flow cytometry that KD also modulates age-related systemic T cell functions. Next, we investigated whether BHB affects brain cells transcriptionally in vitro. Gene expression analysis in primary human brain cells (microglia, astrocytes, neurons) using RNA-seq shows that BHB causes a mild level of inflammation in all three cell types. However, BHB inhibits the more pronounced LPS-induced inflammatory gene activation in microglia. Furthermore, we confirmed that BHB similarly reduces LPS-induced inflammation in primary mouse microglia and bone marrow-derived macrophages (BMDMs). BHB is recognized as an inhibitor of histone deacetylase (HDAC), an inhibitor of NLRP3 inflammasome, and an agonist of the GPCR Hcar2. Nevertheless, in microglia, BHB's anti-inflammatory effects are independent of these known mechanisms. Finally, we examined the brain gene expression of 12-month-old male mice fed with one-week and one-year cyclic KD. While a one-week KD increases inflammatory signaling, a one-year cyclic KD reduces neuroinflammation induced by aging. In summary, our findings demonstrate that BHB mitigates the microglial response to inflammatory stimuli, like LPS, possibly leading to decreased chronic inflammation in the brain after long-term KD treatment in aging mice.
Collapse
Affiliation(s)
| | | | - Sidharth S Madhavan
- Buck Institute for Research on Aging, Novato, CA, USA
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Brenda Eap
- Buck Institute for Research on Aging, Novato, CA, USA
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | | | - Carlos Galicia Aguirre
- Buck Institute for Research on Aging, Novato, CA, USA
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Eric Verdin
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Lisa Ellerby
- Buck Institute for Research on Aging, Novato, CA, USA
| | - David Furman
- Buck Institute for Research on Aging, Novato, CA, USA
| | - John C Newman
- Buck Institute for Research on Aging, Novato, CA, USA
- Division of Geriatrics, University of California, San Francisco, San Francisco, CA, USA
| |
Collapse
|
5
|
Nelson AB, Queathem ED, Puchalska P, Crawford PA. Metabolic Messengers: ketone bodies. Nat Metab 2023; 5:2062-2074. [PMID: 38092961 DOI: 10.1038/s42255-023-00935-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 10/20/2023] [Indexed: 12/21/2023]
Abstract
Prospective molecular targets and therapeutic applications for ketone body metabolism have increased exponentially in the past decade. Initially considered to be restricted in scope as liver-derived alternative fuel sources during periods of carbohydrate restriction or as toxic mediators during diabetic ketotic states, ketogenesis and ketone bodies modulate cellular homeostasis in multiple physiological states through a diversity of mechanisms. Selective signalling functions also complement the metabolic fates of the ketone bodies acetoacetate and D-β-hydroxybutyrate. Here we discuss recent discoveries revealing the pleiotropic roles of ketone bodies, their endogenous sourcing, signalling mechanisms and impact on target organs, and considerations for when they are either stimulated for endogenous production by diets or pharmacological agents or administered as exogenous wellness-promoting agents.
Collapse
Affiliation(s)
- Alisa B Nelson
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Eric D Queathem
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Patrycja Puchalska
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, USA.
| | - Peter A Crawford
- Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, USA.
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
| |
Collapse
|