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Grilo LF, Zimmerman KD, Puppala S, Chan J, Huber HF, Li G, Jadhav AYL, Wang B, Li C, Clarke GD, Register TC, Oliveira PJ, Nathanielsz PW, Olivier M, Pereira SP, Cox LA. Cardiac Molecular Analysis Reveals Aging-Associated Metabolic Alterations Promoting Glycosaminoglycans Accumulation Via Hexosamine Biosynthetic Pathway. bioRxiv 2023:2023.11.17.567640. [PMID: 38014295 PMCID: PMC10680868 DOI: 10.1101/2023.11.17.567640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Age is a prominent risk factor for cardiometabolic disease, and often leads to heart structural and functional changes. However, precise molecular mechanisms underlying cardiac remodeling and dysfunction resulting from physiological aging per se remain elusive. Understanding these mechanisms requires biological models with optimal translation to humans. Previous research demonstrated that baboons undergo age-related reduction in ejection fraction and increased heart sphericity, mirroring changes observed in humans. The goal of this study was to identify early cardiac molecular alterations that precede functional adaptations, shedding light on the regulation of age-associated changes. We performed unbiased transcriptomics of left ventricle (LV) samples from female baboons aged 7.5-22.1 years (human equivalent ~30-88 years). Weighted-gene correlation network and pathway enrichment analyses were performed to identify potential age-associated mechanisms in LV, with histological validation. Myocardial modules of transcripts negatively associated with age were primarily enriched for cardiac metabolism, including oxidative phosphorylation, tricarboxylic acid cycle, glycolysis, and fatty-acid β-oxidation. Transcripts positively correlated with age suggest upregulation of glucose uptake, pentose phosphate pathway, and hexosamine biosynthetic pathway (HBP), indicating a metabolic shift towards glucose-dependent anabolic pathways. Upregulation of HBP commonly results in increased glycosaminoglycan precursor synthesis. Transcripts involved in glycosaminoglycan synthesis, modification, and intermediate metabolism were also upregulated in older animals, while glycosaminoglycan degradation transcripts were downregulated with age. These alterations would promote glycosaminoglycan accumulation, which was verified histologically. Upregulation of extracellular matrix (ECM)-induced signaling pathways temporally coincided with glycosaminoglycan accumulation. We found a subsequent upregulation of cardiac hypertrophy-related pathways and an increase in cardiomyocyte width. Overall, our findings revealed a transcriptional shift in metabolism from catabolic to anabolic pathways that leads to ECM glycosaminoglycan accumulation through HBP prior to upregulation of transcripts of cardiac hypertrophy-related pathways. This study illuminates cellular mechanisms that precede development of cardiac hypertrophy, providing novel potential targets to remediate age-related cardiac diseases.
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Affiliation(s)
- Luís F. Grilo
- CNC-UC, Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
- CIBB, Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Portugal
- University of Coimbra, Institute for Interdisciplinary Research, PDBEB - Doctoral Programme in Experimental Biology and Biomedicine
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Kip D. Zimmerman
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Sobha Puppala
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Jeannie Chan
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Hillary F. Huber
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Ge Li
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Avinash Y. L. Jadhav
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Benlian Wang
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Cun Li
- Texas Pregnancy & Life-Course Health Research Center, Department of Animal Science, University of Wyoming, Laramie, Wyoming, USA
| | - Geoffrey D. Clarke
- Department of Radiology, University of Texas Health Science Center, San Antonio, Texas
| | - Thomas C. Register
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
- Section on Comparative Medicine, Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Paulo J. Oliveira
- CNC-UC, Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
- CIBB, Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Portugal
| | - Peter W. Nathanielsz
- Texas Pregnancy & Life-Course Health Research Center, Department of Animal Science, University of Wyoming, Laramie, Wyoming, USA
| | - Michael Olivier
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Susana P. Pereira
- CNC-UC, Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
- CIBB, Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Portugal
- Laboratory of Metabolism and Exercise (LaMetEx), Research Centre in Physical Activity, Health and Leisure (CIAFEL), Laboratory for Integrative and Translational Research in Population Health (ITR), Faculty of Sports, University of Porto, Porto, Portugal
| | - Laura A. Cox
- Center for Precision Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
- Section on Comparative Medicine, Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC, USA
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Pollak NM, Jaeger D, Kolleritsch S, Zimmermann R, Zechner R, Lass A, Haemmerle G. The interplay of protein kinase A and perilipin 5 regulates cardiac lipolysis. J Biol Chem 2015; 290:1295-306. [PMID: 25418045 PMCID: PMC4340377 DOI: 10.1074/jbc.m114.604744] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 11/21/2014] [Indexed: 12/21/2022] Open
Abstract
Defective lipolysis in mice lacking adipose triglyceride lipase provokes severe cardiac steatosis and heart dysfunction, markedly shortening life span. Similarly, cardiac muscle (CM)-specific Plin5 overexpression (CM-Plin5) leads to severe triglyceride (TG) accumulation in cardiomyocytes via impairing TG breakdown. Interestingly, cardiac steatosis due to overexpression of Plin5 is compatible with normal heart function and life span indicating a more moderate impact of Plin5 overexpression on cardiac lipolysis and energy metabolism. We hypothesized that cardiac Plin5 overexpression does not constantly impair cardiac lipolysis. In line with this assumption, TG levels decreased in CM of fasted compared with nonfasted CM-Plin5 mice indicating that fasting may lead to a diminished barrier function of Plin5. Recent studies demonstrated that Plin5 is phosphorylated, and activation of adenylyl cyclase leads to phosphorylation of Plin5, suggesting that Plin5 is a substrate for PKA. Furthermore, any significance of Plin5 phosphorylation by PKA in the regulation of TG mobilization from lipid droplets (LDs) is unknown. Here, we show that the lipolytic barrier of Plin5-enriched LDs, either prepared from cardiac tissue of CM-Plin5 mice or Plin5-transfected cells, is abrogated by incubation with PKA. Notably, PKA-induced lipolysis of LDs enriched with Plin5 carrying a single mutation at serine 155 (PlinS155A) of the putative PKA phosphorylation site was substantially impaired revealing a critical role for PKA in Plin5-regulated lipolysis. The strong increase in protein levels of phosphorylated PKA in CM of Plin5 transgenic mice may partially restore fatty acid release from Plin5-enriched LDs, rendering these hearts compatible with normal heart function despite massive steatosis.
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Affiliation(s)
- Nina M Pollak
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Doris Jaeger
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | | | - Robert Zimmermann
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Rudolf Zechner
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Achim Lass
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Guenter Haemmerle
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
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Liu L, Trent CM, Fang X, Son NH, Jiang H, Blaner WS, Hu Y, Yin YX, Farese RV, Homma S, Turnbull AV, Eriksson JW, Hu SL, Ginsberg HN, Huang LS, Goldberg IJ. Cardiomyocyte-specific loss of diacylglycerol acyltransferase 1 (DGAT1) reproduces the abnormalities in lipids found in severe heart failure. J Biol Chem 2014; 289:29881-91. [PMID: 25157099 DOI: 10.1074/jbc.m114.601864] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Diacylglycerol acyltransferase 1 (DGAT1) catalyzes the final step in triglyceride synthesis, the conversion of diacylglycerol (DAG) to triglyceride. Dgat1(-/-) mice exhibit a number of beneficial metabolic effects including reduced obesity and improved insulin sensitivity and no known cardiac dysfunction. In contrast, failing human hearts have severely reduced DGAT1 expression associated with accumulation of DAGs and ceramides. To test whether DGAT1 loss alone affects heart function, we created cardiomyocyte-specific DGAT1 knock-out (hDgat1(-/-)) mice. hDgat1(-/-) mouse hearts had 95% increased DAG and 85% increased ceramides compared with floxed controls. 50% of these mice died by 9 months of age. The heart failure marker brain natriuretic peptide increased 5-fold in hDgat1(-/-) hearts, and fractional shortening (FS) was reduced. This was associated with increased expression of peroxisome proliferator-activated receptor α and cluster of differentiation 36. We crossed hDgat1(-/-) mice with previously described enterocyte-specific Dgat1 knock-out mice (hiDgat1(-/-)). This corrected the early mortality, improved FS, and reduced cardiac ceramide and DAG content. Treatment of hDgat1(-/-) mice with the glucagon-like peptide 1 receptor agonist exenatide also improved FS and reduced heart DAG and ceramide content. Increased fatty acid uptake into hDgat1(-/-) hearts was normalized by exenatide. Reduced activation of protein kinase Cα (PKCα), which is increased by DAG and ceramides, paralleled the reductions in these lipids. Our mouse studies show that loss of DGAT1 reproduces the lipid abnormalities seen in severe human heart failure.
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Affiliation(s)
- Li Liu
- From the Divisions of Preventive Medicine and Nutrition and Institute of Systems Biomedicine, Peking University Health Science Center, 100083 Beijing, China
| | - Chad M Trent
- From the Divisions of Preventive Medicine and Nutrition and
| | - Xiang Fang
- From the Divisions of Preventive Medicine and Nutrition and Department of Geriatrics, Affiliated Provincial Hospital, Anhui Medical University, 230001 Hefei, China
| | - Ni-Huiping Son
- From the Divisions of Preventive Medicine and Nutrition and
| | - HongFeng Jiang
- From the Divisions of Preventive Medicine and Nutrition and
| | | | - Yunying Hu
- From the Divisions of Preventive Medicine and Nutrition and
| | - Yu-Xin Yin
- Institute of Systems Biomedicine, Peking University Health Science Center, 100083 Beijing, China
| | - Robert V Farese
- Gladstone Institute of Cardiovascular Disease and Departments of Medicine and Biochemistry and Biophysics, University of California, San Francisco, California 94158
| | - Shunichi Homma
- Cardiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | | | - Jan W Eriksson
- Astra-Zeneca Company, 431 50 Mölndal, Sweden, Department of Medical Sciences, Uppsala University, 751 05 Uppsala, Sweden, and
| | - Shi-Lian Hu
- Department of Geriatrics, Affiliated Provincial Hospital, Anhui Medical University, 230001 Hefei, China
| | | | - Li-Shin Huang
- From the Divisions of Preventive Medicine and Nutrition and
| | - Ira J Goldberg
- From the Divisions of Preventive Medicine and Nutrition and Cardiology, Columbia University College of Physicians and Surgeons, New York, New York 10032, Division of Endocrinology, Diabetes, and Metabolism, New York University Langone School of Medicine, New York, New York 10016
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Reineke EL, Benham A, Soibam B, Stashi E, Taegtmeyer H, Entman ML, Schwartz RJ, O'Malley BW. Steroid receptor coactivator-2 is a dual regulator of cardiac transcription factor function. J Biol Chem 2014; 289:17721-31. [PMID: 24811170 DOI: 10.1074/jbc.m113.539908] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
We have previously demonstrated the potential role of steroid receptor coactivator-2 (SRC-2) as a co-regulator in the transcription of critical molecules modulating cardiac function and metabolism in normal and stressed hearts. The present study seeks to extend the previous information by demonstrating SRC-2 fulfills this role by serving as a critical coactivator for the transcription and activity of critical transcription factors known to control cardiac growth and metabolism as well as in their downstream signaling. This knowledge broadens our understanding of the mechanism by which SRC-2 acts in normal and stressed hearts and allows further investigation of the transcriptional modifications mediating different types and degrees of cardiac stress. Moreover, the genetic manipulation of SRC-2 in this study is specific for the heart and thereby eliminating potential indirect effects of SRC-2 deletion in other organs. We have shown that SRC-2 is critical to transcriptional control modulated by MEF2, GATA-4, and Tbx5, thereby enhancing gene expression associated with cardiac growth. Additionally, we describe SRC-2 as a novel regulator of PPARα expression, thus controlling critical steps in metabolic gene expression. We conclude that through regulation of cardiac transcription factor expression and activity, SRC-2 is a critical transcriptional regulator of genes important for cardiac growth, structure, and metabolism, three of the main pathways altered during the cardiac stress response.
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Affiliation(s)
- Erin L Reineke
- From the Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Ashley Benham
- the Stem Cell Engineering Department, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030
| | - Benjamin Soibam
- the Stem Cell Engineering Department, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030
| | - Erin Stashi
- From the Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Heinrich Taegtmeyer
- the Department of Internal Medicine, Division of Cardiology, The University of Texas Medical School at Houston, Houston, Texas 77030
| | - Mark L Entman
- the Department of Medicine, Division of Cardiovascular Sciences, Baylor College of Medicine, Houston, Texas 77030, and
| | - Robert J Schwartz
- the Stem Cell Engineering Department, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, the Department of Biology and Biochemistry, University of Houston, Houston, Texas 77004
| | - Bert W O'Malley
- From the Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030,
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Sun X, Momen A, Wu J, Noyan H, Li R, von Harsdorf R, Husain M. p27 protein protects metabolically stressed cardiomyocytes from apoptosis by promoting autophagy. J Biol Chem 2014; 289:16924-35. [PMID: 24794871 DOI: 10.1074/jbc.m113.542795] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
p27(Kip1) (p27), a key regulator of cell division, has been implicated in autophagy of cancer cells. However, its role in autophagy, the evolutionarily conserved catabolic process that enables cells to remove unwanted proteins and damaged organelles, had not been examined in the heart. Here we report that ectopic delivery of a p27 fusion protein (TAT-p27) was sufficient to induce autophagy in neonatal rat ventricular cardiomyocytes in vitro, under basal conditions and after glucose deprivation. Conversely, lentivirus-delivered shRNA against p27 successfully reduced p27 levels and suppressed basal and glucose-deprived levels of autophagy in cardiomyocytes in vitro. Glucose deprivation mimics myocardial ischemia and induces apoptosis in cardiomyocytes. During glucose deprivation, TAT-p27 inhibited apoptosis, whereas down-regulation of p27 decreased survival of cardiomyocytes. However, inhibition of autophagy by pharmacological (3-methyladenine, chloroquine, or bafilomycin A1) or genetic approaches (siRNA-mediated knockdown of Atg5) sensitized cardiomyocytes to glucose deprivation-induced apoptosis, even in the presence of TAT-p27. TAT-p27 was also able to provoke greater levels of autophagy in resting and fasting cardiomyocytes in vivo. Further, TAT-p27 enhanced autophagy and repressed cardiomyocytes apoptosis, improved cardiac function, and reduced infarct size following myocardial infarction. Again, these effects were lost when cardiac autophagy in vivo was blocked by chloroquine. Taken together, these data show that p27 positively regulates cardiac autophagy in vitro and in vivo, at rest and after metabolic stress, and that TAT-p27 inhibits apoptosis by promoting autophagy in glucose-deprived cardiomyocytes in vitro and in post-myocardial infarction hearts in vivo.
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Affiliation(s)
- Xuetao Sun
- From the Toronto General Research Institute
| | | | - Jun Wu
- From the Toronto General Research Institute
| | | | - Renke Li
- From the Toronto General Research Institute, Peter Munk Cardiac Centre, and
| | - Rüdiger von Harsdorf
- From the Toronto General Research Institute, Peter Munk Cardiac Centre, and McEwen Centre for Regenerative Medicine, University Health Network, Toronto, Ontario M5G 2C4, Canada, and the Department of Medicine and
| | - Mansoor Husain
- From the Toronto General Research Institute, Peter Munk Cardiac Centre, and McEwen Centre for Regenerative Medicine, University Health Network, Toronto, Ontario M5G 2C4, Canada, and the Department of Medicine and Heart and Stroke/Richard Lewar Centre of Excellence, University of Toronto, Toronto M5G 1L7, Canada
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Mailloux RJ, Xuan JY, McBride S, Maharsy W, Thorn S, Holterman CE, Kennedy CRJ, Rippstein P, deKemp R, da Silva J, Nemer M, Lou M, Harper ME. Glutaredoxin-2 is required to control oxidative phosphorylation in cardiac muscle by mediating deglutathionylation reactions. J Biol Chem 2014; 289:14812-28. [PMID: 24727547 DOI: 10.1074/jbc.m114.550574] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Glutaredoxin-2 (Grx2) modulates the activity of several mitochondrial proteins in cardiac tissue by catalyzing deglutathionylation reactions. However, it remains uncertain whether Grx2 is required to control mitochondrial ATP output in heart. Here, we report that Grx2 plays a vital role modulating mitochondrial energetics and heart physiology by mediating the deglutathionylation of mitochondrial proteins. Deletion of Grx2 (Grx2(-/-)) decreased ATP production by complex I-linked substrates to half that in wild type (WT) mitochondria. Decreased respiration was associated with increased complex I glutathionylation diminishing its activity. Tissue glucose uptake was concomitantly increased. Mitochondrial ATP output and complex I activity could be recovered by restoring the redox environment to that favoring the deglutathionylated states of proteins. Grx2(-/-) hearts also developed left ventricular hypertrophy and fibrosis, and mice became hypertensive. Mitochondrial energetics from Grx2 heterozygotes (Grx2(+/-)) were also dysfunctional, and hearts were hypertrophic. Intriguingly, Grx2(+/-) mice were far less hypertensive than Grx2(-/-) mice. Thus, Grx2 plays a vital role in modulating mitochondrial metabolism in cardiac muscle, and Grx2 deficiency leads to pathology. As mitochondrial ATP production was restored by the addition of reductants, these findings may be relevant to novel redox-related therapies in cardiac disease.
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Affiliation(s)
- Ryan J Mailloux
- From the Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Jian Ying Xuan
- From the Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Skye McBride
- From the Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Wael Maharsy
- From the Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Stephanie Thorn
- the University of Ottawa Heart Institute, Ottawa, Ontario K1Y 4W7, Canada
| | - Chet E Holterman
- the Kidney Research Centre, Ottawa Hospital Research Institute, Ottawa Hospital, Ottawa, Ontario K1H 8L6, Canada, and
| | - Christopher R J Kennedy
- the Kidney Research Centre, Ottawa Hospital Research Institute, Ottawa Hospital, Ottawa, Ontario K1H 8L6, Canada, and
| | - Peter Rippstein
- the University of Ottawa Heart Institute, Ottawa, Ontario K1Y 4W7, Canada
| | - Robert deKemp
- the University of Ottawa Heart Institute, Ottawa, Ontario K1Y 4W7, Canada
| | - Jean da Silva
- the University of Ottawa Heart Institute, Ottawa, Ontario K1Y 4W7, Canada
| | - Mona Nemer
- From the Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Marjorie Lou
- the Center of Redox Biology and School of Veterinary Medicine and Biomedical Sciences, University of Nebraska at Lincoln, Lincoln, Nebraska 68583-0903
| | - Mary-Ellen Harper
- From the Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada,
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Prosdocimo DA, Anand P, Liao X, Zhu H, Shelkay S, Artero-Calderon P, Zhang L, Kirsh J, Moore D, Rosca MG, Vazquez E, Kerner J, Akat KM, Williams Z, Zhao J, Fujioka H, Tuschl T, Bai X, Schulze PC, Hoppel CL, Jain MK, Haldar SM. Kruppel-like factor 15 is a critical regulator of cardiac lipid metabolism. J Biol Chem 2014; 289:5914-24. [PMID: 24407292 DOI: 10.1074/jbc.m113.531384] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The mammalian heart, the body's largest energy consumer, has evolved robust mechanisms to tightly couple fuel supply with energy demand across a wide range of physiologic and pathophysiologic states, yet, when compared with other organs, relatively little is known about the molecular machinery that directly governs metabolic plasticity in the heart. Although previous studies have defined Kruppel-like factor 15 (KLF15) as a transcriptional repressor of pathologic cardiac hypertrophy, a direct role for the KLF family in cardiac metabolism has not been previously established. We show in human heart samples that KLF15 is induced after birth and reduced in heart failure, a myocardial expression pattern that parallels reliance on lipid oxidation. Isolated working heart studies and unbiased transcriptomic profiling in Klf15-deficient hearts demonstrate that KLF15 is an essential regulator of lipid flux and metabolic homeostasis in the adult myocardium. An important mechanism by which KLF15 regulates its direct transcriptional targets is via interaction with p300 and recruitment of this critical co-activator to promoters. This study establishes KLF15 as a key regulator of myocardial lipid utilization and is the first to implicate the KLF transcription factor family in cardiac metabolism.
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Affiliation(s)
- Domenick A Prosdocimo
- From the Case Cardiovascular Research Institute and Harrington Heart and Vascular Institute
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Lai L, Wang M, Martin OJ, Leone TC, Vega RB, Han X, Kelly DP. A role for peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1) in the regulation of cardiac mitochondrial phospholipid biosynthesis. J Biol Chem 2013; 289:2250-9. [PMID: 24337569 DOI: 10.1074/jbc.m113.523654] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The energy demands of the adult mammalian heart are met largely by ATP generated via oxidation of fatty acids in a high capacity mitochondrial system. Peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1)-α and -β serve as inducible transcriptional coregulators of genes involved in mitochondrial biogenesis and metabolism. Whether PGC-1 plays a role in the regulation of mitochondrial structure is unknown. In this study, mice with combined deficiency of PGC-1α and PGC-1β (PGC-1αβ(-/-)) in adult heart were analyzed. PGC-1αβ(-/-) hearts exhibited a distinctive mitochondrial cristae-stacking abnormality suggestive of a phospholipid abnormality as has been described in humans with genetic defects in cardiolipin (CL) synthesis (Barth syndrome). A subset of molecular species, containing n-3 polyunsaturated species in the CL, phosphatidylcholine, and phosphatidylethanolamine profiles, was reduced in PGC-1αβ-deficient hearts. Gene expression profiling of PGC-1αβ(-/-) hearts revealed reduced expression of the gene encoding CDP-diacylglycerol synthase 1 (Cds1), an enzyme that catalyzes the proximal step in CL biosynthesis. Cds1 gene promoter-reporter cotransfection experiments and chromatin immunoprecipitation studies demonstrated that PGC-1α coregulates estrogen-related receptors to activate the transcription of the Cds1 gene. We conclude that the PGC-1/estrogen-related receptor axis coordinately regulates metabolic and membrane structural programs relevant to the maintenance of high capacity mitochondrial function in heart.
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Affiliation(s)
- Ling Lai
- From the Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, Florida 32827
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Baba SP, Hoetker JD, Merchant M, Klein JB, Cai J, Barski OA, Conklin DJ, Bhatnagar A. Role of aldose reductase in the metabolism and detoxification of carnosine-acrolein conjugates. J Biol Chem 2013; 288:28163-79. [PMID: 23928303 DOI: 10.1074/jbc.m113.504753] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Oxidation of unsaturated lipids generates reactive aldehydes that accumulate in tissues during inflammation, ischemia, or aging. These aldehydes form covalent adducts with histidine-containing dipeptides such as carnosine and anserine, which are present in high concentration in skeletal muscle, heart, and brain. The metabolic pathways involved in the detoxification and elimination of these conjugates are, however, poorly defined, and their significance in regulating oxidative stress is unclear. Here we report that conjugates of carnosine with aldehydes such as acrolein are produced during normal metabolism and excreted in the urine of mice and adult human non-smokers as carnosine-propanols. Our studies show that the reduction of carnosine-propanals is catalyzed by the enzyme aldose reductase (AR). Carnosine-propanals were converted to carnosine-propanols in the lysates of heart, skeletal muscle, and brain tissue from wild-type (WT) but not AR-null mice. In comparison with WT mice, the urinary excretion of carnosine-propanols was decreased in AR-null mice. Carnosine-propanals formed covalent adducts with nucleophilic amino acids leading to the generation of carnosinylated proteins. Deletion of AR increased the abundance of proteins bound to carnosine in skeletal muscle, brain, and heart of aged mice and promoted the accumulation of carnosinylated proteins in hearts subjected to global ischemia ex vivo. Perfusion with carnosine promoted post-ischemic functional recovery in WT but not in AR-null mouse hearts. Collectively, these findings reveal a previously unknown metabolic pathway for the removal of carnosine-propanal conjugates and suggest a new role of AR as a critical regulator of protein carnosinylation and carnosine-mediated tissue protection.
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