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

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.

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

Circulation ◽

10.1161/circ.142.suppl_3.15978 ◽

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.

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The Drosophila Citrate Lyase Is Required for Cell Division during Spermatogenesis

Cells ◽

10.3390/cells9010206 ◽

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.

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

Journal of Biological Chemistry ◽

10.1074/jbc.m116.750620 ◽

2017 ◽

Vol 292 (8) ◽

pp. 3312-3322 ◽

Cited By ~ 64

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.

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

Genes ◽

10.3390/genes12091460 ◽

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.

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

Frontiers in Immunology ◽

10.3389/fimmu.2021.632526 ◽

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.

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Acetyl-CoA is produced by the citrate synthase homology module of ATP-citrate lyase

Nature Structural & Molecular Biology ◽

10.1038/s41594-021-00624-3 ◽

2021 ◽

Author(s):

Kenneth Verstraete ◽

Koen H. G. Verschueren ◽

Ann Dansercoer ◽

Savvas N. Savvides

Keyword(s):

Citrate Synthase ◽

Atp Citrate Lyase ◽

Acetyl Coa ◽

Citrate Lyase ◽

Homology Module

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Effects of Qijin granules on high glucose-induced proliferation, apoptosis and expression of nuclear factor- κB and MCP-1 in rat glomerular mesangial cells

Tropical Journal of Pharmaceutical Research ◽

10.4314/tjpr.v20i9.6 ◽

2021 ◽

Vol 20 (9) ◽

pp. 1819-1826

Author(s):

Yuanfeng Yang ◽

Gaocai Xiong ◽

Renhui Yang ◽

Yuchuan Li ◽

Yuling Luo ◽

...

Keyword(s):

Cell Cycle ◽

High Glucose ◽

Mesangial Cells ◽

Control Group ◽

Glomerular Mesangial Cells ◽

Smad Signaling ◽

Apoptosis Rate ◽

Proliferation And Apoptosis ◽

Protein Expressions ◽

Tgf Β1

Purpose: To investigate the effects of Qijin granules on high glucose-induced proliferation and apoptosis in rat glomerular mesangial cells (MC).Methods: MC cells from rats were passaged and cultured, and randomly divided into control group (CNG), high glucose group (HGG), Western medicine group (WMG, high glucose + Benazepril + Gliquidone), and Qijin granules 1/2/3 group (high glucose + different doses of Qijin granules). Mesangial cells proliferation was measured using MTT assay. The NF-κB, MCP-1 and inflammatory factors in supernatant were determined by ELISA. Apoptosis rate and cell cycle were assessed by flow cytometry. The apoptosis-related TGF-β1/Smad signaling pathway-related protein expressions were measured by Western blot.Results: The A-value and early apoptosis rate, apoptosis rate and S-phase percentage, and protein expressions of NF-κB, MCP-1, IL-6, IL-2, TNF-ɑ, Bax, Cyt-C, caspase-3, TGF-β1, and p-Smad3 of MC cells in the HGG at 12 h, 24 h and 48 h were higher than those in the CNG. The above indices were lower in the WMG, and Qijin granules 1/2/3 groups than in the HGG. The Bcl-2, Smad7 protein expression level and the percentage of G1 and G2/M phase were lower in the HGG than in the CNG, and the above indeices were higher in the WMG and Qijin granules 1/2/3 group than in HGG.Conclusion: Qijin granules can dose-dependently inhibit high glucose-induced proliferation and apoptosis in rat MC cells, block the cell cycle and reduce inflammatory responses. This may be related to the regulation of NF-κB, MCP-1 and TGF-β1/Smad signaling pathways. These findings provide theoretical and experimental basis for the clinical treatment of early diabetic nephropathy.

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The Inhibitory Effect of siRNAs on The High Glucose-Induced Overexpression of TGF-β1 in Mesangial Cells

Journal of Korean Medical Science ◽

10.3346/jkms.2006.21.3.430 ◽

2006 ◽

Vol 21 (3) ◽

pp. 430 ◽

Cited By ~ 5

Author(s):

Hey-Jeong Noh ◽

Hyun-Chul Kim ◽

Sang-Sook Lee ◽

Yu-Na Kang ◽

Young-Mi Chae ◽

...

Keyword(s):

High Glucose ◽

Mesangial Cells ◽

Inhibitory Effect ◽

Tgf Β1

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TGF-β1 modifies histone acetylation and acetyl-coenzyme A metabolism in renal myofibroblasts

AJP Renal Physiology ◽

10.1152/ajprenal.00513.2018 ◽

2019 ◽

Vol 316 (3) ◽

pp. F517-F529 ◽

Cited By ~ 6

Author(s):

Edward R. Smith ◽

Belinda Wigg ◽

Stephen G. Holt ◽

Timothy D. Hewitson

Keyword(s):

Histone Acetylation ◽

Transforming Growth Factor ◽

Aerobic Glycolysis ◽

Transforming Growth Factor Β1 ◽

Metabolic Reprogramming ◽

Acetyl Coa ◽

Hdac Activity ◽

Protein Levels ◽

H3 Acetylation ◽

Tgf Β1

Histone acetylation is an important modulator of gene expression in fibrosis. This study examined the effect of the pre-eminent fibrogenic cytokine transforming growth factor-β1 (TGF-β1) on histone 3 (H3) acetylation and its regulatory kinetics in renal myofibroblasts. Fibroblasts propagated from rat kidneys after ureteric obstruction were treated with recombinant TGF-β1 or vehicle for 48 h. TGF-β1-induced myofibroblast activation was accompanied by a net decrease in total H3 acetylation, although changes in individual marks were variable. This was paralleled by a generalized reduction in histone acetyltransferases (HAT) and divergent changes in histone deacetylase (HDAC) enzymes at both transcript and protein levels. Globally, this was manifest in a reduction in total HAT activity and increase in HDAC activity. TGF-β1 induced a shift in cellular metabolism from oxidative respiration to aerobic glycolysis, resulting in reduced acetyl-CoA. The reduction in total H3 acetylation could be rescued by providing exogenous citrate or alternative sources of acetyl-CoA without ameliorating changes in HAT/HDAC activity. In conclusion, TGF-β1 produces a metabolic reprogramming in renal fibroblasts, with less H3 acetylation through reduced acetylation, increased deacetylation, and changes in carbon availability. Our results suggest that acetyl-CoA availability predominates over HAT and HDAC activity as a key determinant of H3 acetylation in response to TGF-β1.

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