scholarly journals Exploring the Role of ATP-Citrate Lyase in the Immune System

2021 ◽  
Vol 12 ◽  
Author(s):  
Monica Dominguez ◽  
Bernhard Brüne ◽  
Dmitry Namgaladze
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Histone Acetylation ◽  
Epigenetic Regulation ◽  
De Novo ◽  
Regulation Of Gene Expression ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Citrate Lyase

Studies over the past decade have revealed that metabolism profoundly influences immune responses. In particular, metabolism causes epigenetic regulation of gene expression, as a growing number of metabolic intermediates are substrates for histone post-translational modifications altering chromatin structure. One of these substrates is acetyl-coenzyme A (CoA), which donates an acetyl group for histone acetylation. Cytosolic acetyl-CoA is also a critical substrate for de novo synthesis of fatty acids and sterols necessary for rapid cellular growth. One of the main enzymes catalyzing cytosolic acetyl-CoA formation is ATP-citrate lyase (ACLY). In addition to its classical function in the provision of acetyl-CoA for de novo lipogenesis, ACLY contributes to epigenetic regulation through histone acetylation, which is increasingly appreciated. In this review we explore the current knowledge of ACLY and acetyl-CoA in mediating innate and adaptive immune responses. We focus on the role of ACLY in supporting de novo lipogenesis in immune cells as well as on its impact on epigenetic alterations. Moreover, we summarize alternative sources of acetyl-CoA and their contribution to metabolic and epigenetic regulation in cells of the immune system.

Abstract 15978: Acetyl-coa Catalysis by Atp-citrate Lyase is Essential for Myofibroblast Differentiation and Persistence

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Michael P Lazaropoulos ◽  
Andrew A Gibb ◽  
Anh Huynh ◽  
Kathryn Wellen ◽  
John W Elrod
Keyword(s):  
Histone Acetylation ◽  
Transcriptional Activation ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Metabolic Reprogramming ◽  
Myofibroblast Differentiation ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Matrix Deposition ◽  
Citrate Lyase

A feature of heart failure (HF) is excessive extracellular matrix deposition and cardiac remodeling by a differentiated fibroblast population known as myofibroblasts. Identifying mechanisms of myofibroblast differentiation in cardiac fibrosis could yield novel therapeutic targets to delay or reverse HF. Recent evidence suggests that myofibroblast differentiation requires metabolic reprogramming for transcriptional activation of the myofibroblast gene program by chromatin-dependent mechanisms. We previously reported that inhibition of histone demethylation blocks myofibroblast formation, however, whether histone acetylation (e.g., H3K27ac, a prominent mark associated with gene transcription) is involved in fibroblast reprogramming remains unclear. ATP-citrate lyase (ACLY) synthesizes acetyl-CoA and therein supplies acetyl-CoA to the nucleus, where it is used as a substrate by histone acetyltransferases (HATs). To define the role of acetyl-CoA metabolism in myofibroblast differentiation, we stimulated differentiation in mouse embryonic fibroblasts (MEFs) and adult mouse cardiac fibroblasts (ACFs) with the pro-fibrotic agonist transforming growth factor β (TGFβ) and treated cells with a pharmacological inhibitor of ACLY. ACLY inhibition decreased myofibroblast gene expression in ACF and MEFs in TGFβ-stimulated myofibroblast differentiation, in addition to decreasing the population of αSMA positive MEFs. Genetic deletion of ACLY in MEFs recapitulated the results observed with pharmacological inhibition. Encouragingly, the ACLY inhibitor was sufficient to revert fully differentiated myofibroblasts under continuous TGFβ stimulation to a quiescent, non-fibrotic phenotype. Altogether, our data indicate that ACLY activity is necessary for myofibroblast differentiation and persistence. We hypothesize that ACLY-dependent acetyl-CoA synthesis is necessary for histone acetylation and transcriptional activation of the myofibroblast gene program. Currently, we are examining mechanisms of ACLY-dependent chromatin remodeling in fibroblasts and the in vivo relevance of this mechanism in mutant mice. In summary, ACLY is a potential target to reverse cardiac fibrosis and lessen HF.

scholarly journals ATP-citrate lyase is essential for high glucose-induced histone hyperacetylation and fibrogenic gene upregulation in mesangial cells

2017 ◽  
Vol 313 (2) ◽  
pp. F423-F429 ◽  
Author(s):  
Dilip K. Deb ◽  
Yinyin Chen ◽  
Jian Sun ◽  
Youli Wang ◽  
Yan Chun Li
Keyword(s):  
Histone Acetylation ◽  
High Glucose ◽  
Mesangial Cells ◽  
Nuclear Accumulation ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Ecm Proteins ◽  
Histone Hyperacetylation ◽  
Citrate Lyase ◽  
Tgf Β1

The goal of this study was to address the role of ATP-citrate lyase (ACL), an enzyme that converts citrate to acetyl-CoA, in high glucose (HG)-induced histone acetylation and profibrotic gene expression. Our recent ChIP-Seq studies have demonstrated that HG induces genome-wide histone hyperacetylation in mesangial cells (MCs). Here, we showed that exposure of MCs to HG markedly increased histone acetylation at the H3K9/14 and H3K18 marks and induced the expression of potent profibrotic factors TGF-β1, TGF-β3, and connective tissue growth factor (CTGF). The induction of these profibrotic factors was further enhanced by histone deacetylase inhibitor but suppressed by histone acetyl-transferase inhibitor, confirming the importance of histone acetylation in this regulation. Interestingly, HG not only upregulated ACL expression but also promoted ACL nuclear translocation, evidenced by increased ACL concentration and activity in the nuclear extracts. Consistent with this observation, transfection of MCs with a plasmid-carrying green fluorescent protein (GFP)-ACL fusion protein led to GFP nuclear accumulation when cultured in HG condition. Silencing ACL with siRNAs alleviated HG-induced histone hyperacetylation, as well as upregulation of TGF-β1, TGF-β3, CTGF, and extracellular matrix (ECM) proteins fibronectin and collagen type IV, whereas ACL overexpression further enhanced HG induction of histone acetylation, as well as these profibrotic factors and ECM proteins. Collectively, these observations demonstrate that HG promotes ACL expression and translocation into the nucleus, where ACL converts citrate to acetyl-CoA to provide the substrate for histone acetylation, leading to upregulation of fibrogenic genes. Therefore, ACL plays a critical role in epigenetic regulation of diabetic renal fibrosis.

scholarly journals The Drosophila Citrate Lyase Is Required for Cell Division during Spermatogenesis

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 206
Author(s):  
Maria Laura Di Giorgio ◽  
Patrizia Morciano ◽  
Elisabetta Bucciarelli ◽  
Antonella Porrazzo ◽  
Francesca Cipressa ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cell Division ◽  
Histone Acetylation ◽  
Male Meiosis ◽  
Metabolic Enzyme ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Alternative Pathways ◽  
Citrate Lyase ◽  
First Time

The Drosophila melanogaster DmATPCL gene encodes for the human ATP Citrate Lyase (ACL) ortholog, a metabolic enzyme that from citrate generates glucose-derived Acetyl-CoA, which fuels central biochemical reactions such as the synthesis of fatty acids, cholesterol and acetylcholine, and the acetylation of proteins and histones. We had previously reported that, although loss of Drosophila ATPCL reduced levels of Acetyl-CoA, unlike its human counterpart, it does not affect global histone acetylation and gene expression, suggesting that its role in histone acetylation is either partially redundant in Drosophila or compensated by alternative pathways. Here, we describe that depletion of DmATPCL affects spindle organization, cytokinesis, and fusome assembly during male meiosis, revealing an unanticipated role for DmATPCL during spermatogenesis. We also show that DmATPCL mutant meiotic phenotype is in part caused by a reduction of fatty acids, but not of triglycerides or cholesterol, indicating that DmATPCL-derived Acetyl-CoA is predominantly devoted to the biosynthesis of fatty acids during spermatogenesis. Collectively, our results unveil for the first time an involvement for DmATPCL in the regulation of meiotic cell division, which is likely conserved in human cells.

scholarly journals Impact of a High-fat Diet on Tissue Acyl-CoA and Histone Acetylation Levels

2017 ◽  
Vol 292 (8) ◽  
pp. 3312-3322 ◽  
Author(s):  
Alessandro Carrer ◽  
Joshua L. D. Parris ◽  
Sophie Trefely ◽  
Ryan A. Henry ◽  
David C. Montgomery ◽  
...  
Keyword(s):  
Histone Acetylation ◽  
High Fat Diet ◽  
Cell Types ◽  
High Fat ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Citrate Lyase ◽  
Liver And Pancreas ◽  
The Impact

Cellular metabolism dynamically regulates the epigenome via availability of the metabolite substrates of chromatin-modifying enzymes. The impact of diet on the metabolism-epigenome axis is poorly understood but could alter gene expression and influence metabolic health. ATP citrate-lyase produces acetyl-CoA in the nucleus and cytosol and regulates histone acetylation levels in many cell types. Consumption of a high-fat diet (HFD) results in suppression of ATP citrate-lyase levels in tissues such as adipose and liver, but the impact of diet on acetyl-CoA and histone acetylation in these tissues remains unknown. Here we examined the effects of HFD on levels of acyl-CoAs and histone acetylation in mouse white adipose tissue (WAT), liver, and pancreas. We report that mice consuming a HFD have reduced levels of acetyl-CoA and/or acetyl-CoA:CoA ratio in these tissues. In WAT and the pancreas, HFD also impacted the levels of histone acetylation; in particular, histone H3 lysine 23 acetylation was lower in HFD-fed mice. Genetic deletion of Acly in cultured adipocytes also suppressed acetyl-CoA and histone acetylation levels. In the liver, no significant effects on histone acetylation were observed with a HFD despite lower acetyl-CoA levels. Intriguingly, acetylation of several histone lysines correlated with the acetyl-CoA: (iso)butyryl-CoA ratio in liver. Butyryl-CoA and isobutyryl-CoA interacted with the acetyltransferase P300/CBP-associated factor (PCAF) in liver lysates and inhibited its activity in vitro. This study thus provides evidence that diet can impact tissue acyl-CoA and histone acetylation levels and that acetyl-CoA abundance correlates with acetylation of specific histone lysines in WAT but not in the liver.

scholarly journals mTORC2-AKT signaling to ATP-citrate lyase drives brown adipogenesis and de novo lipogenesis

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
C. Martinez Calejman ◽  
S. Trefely ◽  
S. W. Entwisle ◽  
A. Luciano ◽  
S. M. Jung ◽  
...  
Keyword(s):  
De Novo ◽  
Ppar Gamma ◽  
Akt Signaling ◽  
De Novo Lipogenesis ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Brown Adipocytes ◽  
Glucose And Lipid Metabolism ◽  
Citrate Lyase ◽  
Acetyl Coa Synthesis

Abstract mTORC2 phosphorylates AKT in a hydrophobic motif site that is a biomarker of insulin sensitivity. In brown adipocytes, mTORC2 regulates glucose and lipid metabolism, however the mechanism has been unclear because downstream AKT signaling appears unaffected by mTORC2 loss. Here, by applying immunoblotting, targeted phosphoproteomics and metabolite profiling, we identify ATP-citrate lyase (ACLY) as a distinctly mTORC2-sensitive AKT substrate in brown preadipocytes. mTORC2 appears dispensable for most other AKT actions examined, indicating a previously unappreciated selectivity in mTORC2-AKT signaling. Rescue experiments suggest brown preadipocytes require the mTORC2/AKT/ACLY pathway to induce PPAR-gamma and establish the epigenetic landscape during differentiation. Evidence in mature brown adipocytes also suggests mTORC2 acts through ACLY to increase carbohydrate response element binding protein (ChREBP) activity, histone acetylation, and gluco-lipogenic gene expression. Substrate utilization studies additionally implicate mTORC2 in promoting acetyl-CoA synthesis from acetate through acetyl-CoA synthetase 2 (ACSS2). These data suggest that a principal mTORC2 action is controlling nuclear-cytoplasmic acetyl-CoA synthesis.

scholarly journals mTOR complex-2 stimulates acetyl-CoA and de novo lipogenesis through ATP citrate lyase in HER2/PIK3CA-hyperactive breast cancer

Oncotarget ◽  
2016 ◽  
Vol 7 (18) ◽  
pp. 25224-25240 ◽  
Author(s):  
Yaqing Chen ◽  
Jianchang Qian ◽  
Qun He ◽  
Hui Zhao ◽  
Lourdes Toral-Barza ◽  
...  
Keyword(s):  
Breast Cancer ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Citrate Lyase

Probing the link between citrate and malonyl-CoA in perfused rat hearts

2002 ◽  
Vol 283 (4) ◽  
pp. H1379-H1386 ◽  
Author(s):  
Myriame Poirier ◽  
Geneviève Vincent ◽  
Aneta E. Reszko ◽  
Bertrand Bouchard ◽  
Joanne K. Kelleher ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Acid Oxidation ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Rat Hearts ◽  
Citrate Lyase ◽  
Malonyl Coa ◽  
Perfused Rat Hearts ◽  
Citrate Release

Little is known about the sources of cytosolic acetyl-CoA used for the synthesis of malonyl-CoA, a key regulator of fatty acid oxidation in the heart. We tested the hypothesis that citrate provides acetyl-CoA for malonyl-CoA synthesis after its mitochondrial efflux and cleavage by cytosolic ATP-citrate lyase. We expanded on a previous study where we characterized citrate release from perfused rat hearts (Vincent G, Comte B, Poirier M, and Des Rosiers C. Citrate release by perfused rat hearts: a window on mitochondrial cataplerosis. Am J Physiol Endocrinol Metab 278: E846–E856, 2000). In the present study, we show that citrate release rates, ranging from 6 to 22 nmol/min, can support a net increase in malonyl-CoA concentrations induced by changes in substrate supply, at most 0.7 nmol/min. In experiments with [U-13C](lactate + pyruvate) and [1-13C]oleate, we show that the acetyl moiety of malonyl-CoA is derived from both pyruvate and long-chain fatty acids. This 13C-labeling of malonyl-CoA occurred without any changes in its concentration. Hydroxycitrate, an inhibitor of ATP-citrate lyase, prevents increases in malonyl-CoA concentrations and decreases its labeling from [U-13C](lactate + pyruvate). Our data support at least a partial role of citrate in the transfer from the mitochondria to cytosol of acetyl units for malonyl-CoA synthesis. In addition, they provide a dynamic picture of malonyl-CoA metabolism: even when the malonyl-CoA concentration remains constant, there appears to be a constant need to supply acetyl-CoA from various carbon sources, both carbohydrates and lipids, for malonyl-CoA synthesis.

scholarly journals Mammalian SIRT6 Represses Invasive Cancer Cell Phenotypes through ATP Citrate Lyase (ACLY)-Dependent Histone Acetylation

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1460
Author(s):  
Wei Zheng ◽  
Luisa Tasselli ◽  
Tie-mei Li ◽  
Katrin F. Chua
Keyword(s):  
Gene Expression ◽  
Histone Acetylation ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Invasive Cancer ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Citrate Lyase ◽  
Cell Phenotypes ◽  
Invasive Cancer Cell

The modulation of dynamic histone acetylation states is key for organizing chromatin structure and modulating gene expression and is regulated by histone acetyltransferase (HAT) and histone deacetylase (HDAC) enzymes. The mammalian SIRT6 protein, a member of the Class III HDAC Sirtuin family of NAD+-dependent enzymes, plays pivotal roles in aging, metabolism, and cancer biology. Through its site-specific histone deacetylation activity, SIRT6 promotes chromatin silencing and transcriptional regulation of aging-associated, metabolic, and tumor suppressive gene expression programs. ATP citrate lyase (ACLY) is a nucleo-cytoplasmic enzyme that produces acetyl coenzyme A (acetyl-CoA), which is the required acetyl donor for lysine acetylation by HATs. In addition to playing a central role in generating cytosolic acetyl-CoA for de novo lipogenesis, a growing body of work indicates that ACLY also functions in the nucleus where it contributes to the nutrient-sensitive regulation of nuclear acetyl-CoA availability for histone acetylation in cancer cells. In this study, we have identified a novel function of SIRT6 in controlling nuclear levels of ACLY and ACLY-dependent tumor suppressive gene regulation. The inactivation of SIRT6 in cancer cells leads to the accumulation of nuclear ACLY protein and increases nuclear acetyl-CoA pools, which in turn drive locus-specific histone acetylation and the expression of cancer cell adhesion and migration genes that promote tumor invasiveness. Our findings uncover a novel mechanism of SIRT6 in suppressing invasive cancer cell phenotypes and identify acetyl-CoA responsive cell migration and adhesion genes as downstream targets of SIRT6.

scholarly journals Changes in the activity of citrate lyase, malic enzyme and acetyl-CoA synthetase in rat liver after short-term and long-term feeding with ethanol

1973 ◽  
Vol 29 (2) ◽  
pp. 307-316 ◽  
Author(s):  
E. Fellenius ◽  
U. Nisbeth ◽  
L. Pilström ◽  
K.-H. Kiessling
Keyword(s):  
Malic Enzyme ◽  
Liquid Diet ◽  
Short Term ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Pronounced Increase ◽  
Ethanol Group ◽  
Citrate Lyase

1. The effect of short-term and long-term feeding (0–80 d) with a liquid diet containing ethanol on the activity of rat hepatic enzymes related to lipogenesis has been evaluated. Carbohydrates were isoenergetically substituted for ethanol in the control animals.2. The maximum concentration of triglycerides in the livers was reached after about 30 d, when it was almost three times as high as in the control animals. The activity of malic enzyme (EC 1·1·1·40) and ATP citrate lyase (EC 4·1·3·8) decreased significantly in the ethanol group, compared with the control rats, within 10 d and remained low during the rest of the experiment (80 d). After 20 d, the acetyl-CoA synthetase (EC 6·2·1·1) activity increased significantly in the livers of the ethanol-fed rats but fell subsequently to values similar to those in the livers of the control rats. Thus, despite a pronounced increase in the amount of triglyceride in the livers of rats on a liquid diet containing ethanol, there was a dramatic decrease in the activity of the enzymes (malic enzyme and citrate lyase) involved in lipogenesis.3. The almost unchanged activity of acetyl-CoA synthetase shows that the utilization of acetate, produced when ethanol is oxidized, is not stimulated by long-term feeding with ethanol. The involvement of citrate lyase in various postulated shuttles for the transport of reducing equivalents across the mitochondrial membrane and the role of malic enzyme in the microsomal ethanol-oxidizing system are discussed.

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