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Akinyele O, Munir A, Johnson MA, Perez MS, Gao Y, Foley JR, Nwafor A, Wu Y, Murray-Stewart T, Casero RA, Bayir H, Kemaladewi DU. Impaired polyamine metabolism causes behavioral and neuroanatomical defects in a mouse model of Snyder-Robinson syndrome. Dis Model Mech 2024; 17:dmm050639. [PMID: 38463005 DOI: 10.1242/dmm.050639] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/28/2024] [Indexed: 03/12/2024] Open
Abstract
Snyder-Robinson syndrome (SRS) is a rare X-linked recessive disorder caused by a mutation in the SMS gene, which encodes spermine synthase, and aberrant polyamine metabolism. SRS is characterized by intellectual disability, thin habitus, seizure, low muscle tone/hypotonia and osteoporosis. Progress towards understanding and treating SRS requires a model that recapitulates human gene variants and disease presentations. Here, we evaluated molecular and neurological presentations in the G56S mouse model, which carries a missense mutation in the Sms gene. The lack of SMS protein in the G56S mice resulted in increased spermidine/spermine ratio, failure to thrive, short stature and reduced bone density. They showed impaired learning capacity, increased anxiety, reduced mobility and heightened fear responses, accompanied by reduced total and regional brain volumes. Furthermore, impaired mitochondrial oxidative phosphorylation was evident in G56S cerebral cortex, G56S fibroblasts and Sms-null hippocampal cells, indicating that SMS may serve as a future therapeutic target. Collectively, our study establishes the suitability of the G56S mice as a preclinical model for SRS and provides a set of molecular and functional outcome measures that can be used to evaluate therapeutic interventions for SRS.
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Affiliation(s)
- Oluwaseun Akinyele
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Anushe Munir
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
- Department of Human Genetics, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Marie A Johnson
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Megan S Perez
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
- Department of Human Genetics, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Yuan Gao
- Children's Neuroscience Institute, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Jackson R Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
| | - Ashley Nwafor
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
| | - Yijen Wu
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Tracy Murray-Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
| | - Robert A Casero
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
| | - Hülya Bayir
- Children's Neuroscience Institute, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Dwi U Kemaladewi
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
- Department of Human Genetics, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Children's Neuroscience Institute, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
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2
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Tao X, Liu J, Diaz-Perez Z, Foley JR, Nwafor A, Stewart TM, Casero RA, Zhai RG. Reduction of spermine synthase enhances autophagy to suppress Tau accumulation. Cell Death Dis 2024; 15:333. [PMID: 38740758 DOI: 10.1038/s41419-024-06720-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 04/29/2024] [Accepted: 05/03/2024] [Indexed: 05/16/2024]
Abstract
Precise polyamine metabolism regulation is vital for cells and organisms. Mutations in spermine synthase (SMS) cause Snyder-Robinson intellectual disability syndrome (SRS), characterized by significant spermidine accumulation and autophagy blockage in the nervous system. Emerging evidence connects polyamine metabolism with other autophagy-related diseases, such as Tauopathy, however, the functional intersection between polyamine metabolism and autophagy in the context of these diseases remains unclear. Here, we altered SMS expression level to investigate the regulation of autophagy by modulated polyamine metabolism in Tauopathy in Drosophila and human cellular models. Interestingly, while complete loss of Drosophila spermine synthase (dSms) impairs lysosomal function and blocks autophagic flux recapitulating SRS disease phenotype, partial loss of dSms enhanced autophagic flux, reduced Tau protein accumulation, and led to extended lifespan and improved climbing performance in Tauopathy flies. Measurement of polyamine levels detected a mild elevation of spermidine in flies with partial loss of dSms. Similarly, in human neuronal or glial cells, partial loss of SMS by siRNA-mediated knockdown upregulated autophagic flux and reduced Tau protein accumulation. Importantly, proteomics analysis of postmortem brain tissue from Alzheimer's disease (AD) patients showed a significant albeit modest elevation of SMS level. Taken together, our study uncovers a functional correlation between polyamine metabolism and autophagy in AD: SMS reduction upregulates autophagy, suppresses Tau accumulation, and ameliorates neurodegeneration and cell death. These findings provide a new potential therapeutic target for AD.
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Affiliation(s)
- Xianzun Tao
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jiaqi Liu
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Zoraida Diaz-Perez
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jackson R Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Ashley Nwafor
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Robert A Casero
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - R Grace Zhai
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA.
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3
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Stewart TM, Foley JR, Holbert CE, Khomutov M, Rastkari N, Tao X, Khomutov AR, Zhai RG, Casero RA. Difluoromethylornithine rebalances aberrant polyamine ratios in Snyder-Robinson syndrome. EMBO Mol Med 2023; 15:e17833. [PMID: 37702369 PMCID: PMC10630878 DOI: 10.15252/emmm.202317833] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 08/18/2023] [Accepted: 08/30/2023] [Indexed: 09/14/2023] Open
Abstract
Snyder-Robinson syndrome (SRS) results from mutations in spermine synthase (SMS), which converts the polyamine spermidine into spermine. Affecting primarily males, common manifestations of SRS include intellectual disability, osteoporosis, hypotonia, and seizures. Symptom management is the only treatment. Reduced SMS activity causes spermidine accumulation while spermine levels are reduced. The resulting exaggerated spermidine:spermine ratio is a biochemical hallmark of SRS that tends to correlate with symptom severity. Our studies aim to pharmacologically manipulate polyamine metabolism to correct this imbalance as a therapeutic strategy for SRS. Here we report the repurposing of 2-difluoromethylornithine (DFMO), an FDA-approved inhibitor of polyamine biosynthesis, in rebalancing spermidine:spermine ratios in SRS patient cells. Mechanistic in vitro studies demonstrate that, while reducing spermidine biosynthesis, DFMO also stimulates the conversion of spermidine into spermine in hypomorphic SMS cells and induces uptake of exogenous spermine, altogether reducing the aberrant ratios. In a Drosophila SRS model characterized by reduced lifespan, DFMO improves longevity. As nearly all SRS patient mutations are hypomorphic, these studies form a strong foundation for translational studies with significant therapeutic potential.
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Affiliation(s)
- Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer CenterJohns Hopkins School of MedicineBaltimoreMDUSA
| | - Jackson R Foley
- Sidney Kimmel Comprehensive Cancer CenterJohns Hopkins School of MedicineBaltimoreMDUSA
| | - Cassandra E Holbert
- Sidney Kimmel Comprehensive Cancer CenterJohns Hopkins School of MedicineBaltimoreMDUSA
| | - Maxim Khomutov
- Engelhardt Institute of Molecular BiologyRussian Academy of SciencesMoscowRussia
| | - Noushin Rastkari
- Sidney Kimmel Comprehensive Cancer CenterJohns Hopkins School of MedicineBaltimoreMDUSA
| | - Xianzun Tao
- Department of Molecular and Cellular PharmacologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Alex R Khomutov
- Engelhardt Institute of Molecular BiologyRussian Academy of SciencesMoscowRussia
| | - R Grace Zhai
- Department of Molecular and Cellular PharmacologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Robert A Casero
- Sidney Kimmel Comprehensive Cancer CenterJohns Hopkins School of MedicineBaltimoreMDUSA
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4
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Padgett LR, Shinkle MR, Rosario S, Stewart TM, Foley JR, Casero RA, Park MH, Chung WK, Mastracci TL. Deoxyhypusine synthase mutations alter the post-translational modification of eukaryotic initiation factor 5A resulting in impaired human and mouse neural homeostasis. HGG Adv 2023; 4:100206. [PMID: 37333770 PMCID: PMC10275725 DOI: 10.1016/j.xhgg.2023.100206] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 05/11/2023] [Accepted: 05/15/2023] [Indexed: 06/20/2023] Open
Abstract
DHPS deficiency is a rare genetic disease caused by biallelic hypomorphic variants in the Deoxyhypusine synthase (DHPS) gene. The DHPS enzyme functions in mRNA translation by catalyzing the post-translational modification, and therefore activation, of eukaryotic initiation factor 5A (eIF5A). The observed clinical outcomes associated with human mutations in DHPS include developmental delay, intellectual disability, and seizures. Therefore, to increase our understanding of this rare disease, it is critical to determine the mechanisms by which mutations in DHPS alter neurodevelopment. In this study, we have generated patient-derived lymphoblast cell lines and demonstrated that human DHPS variants alter DHPS protein abundance and impair enzyme function. Moreover, we observe a shift in the abundance of the post-translationally modified forms of eIF5A; specifically, an increase in the nuclear localized acetylated form (eIF5AAcK47) and concomitant decrease in the cytoplasmic localized hypusinated form (eIF5AHYP). Generation and characterization of a mouse model with a genetic deletion of Dhps in the brain at birth shows that loss of hypusine biosynthesis impacts neuronal function due to impaired eIF5AHYP-dependent mRNA translation; this translation defect results in altered expression of proteins required for proper neuronal development and function. This study reveals new insight into the biological consequences and molecular impact of human DHPS deficiency and provides valuable information toward the goal of developing treatment strategies for this rare disease.
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Affiliation(s)
- Leah R. Padgett
- Indiana Biosciences Research Institute, Indianapolis, IN 46202, USA
| | - Mollie R. Shinkle
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Spencer Rosario
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14203, USA
| | - Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Jackson R. Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Robert A. Casero
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Myung Hee Park
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA
| | - Wendy K. Chung
- Departments of Pediatrics and Medicine, Columbia University, New York, NY 10032, USA
| | - Teresa L. Mastracci
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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5
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Stewart TRM, Foley JR, Holbert CE, Khomutov MA, Rastkari N, Tao X, Khomutov AR, Zhai RG, Casero RA. Difluoromethylornithine rebalances aberrant polyamine ratios in Snyder-Robinson syndrome: mechanism of action and therapeutic potential. bioRxiv 2023:2023.03.30.534977. [PMID: 37034775 PMCID: PMC10081208 DOI: 10.1101/2023.03.30.534977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Snyder-Robinson Syndrome (SRS) is caused by mutations in the spermine synthase (SMS) gene, the enzyme product of which converts the polyamine spermidine into spermine. Affecting primarily males, common manifestations of SRS include intellectual disability, osteoporosis, hypotonic musculature, and seizures, along with other more variable symptoms. Currently, medical management focuses on treating these symptoms without addressing the underlying molecular cause of the disease. Reduced SMS catalytic activity in cells of SRS patients causes the accumulation of spermidine, while spermine levels are reduced. The resulting exaggeration in spermidine-to-spermine ratio is a biochemical hallmark of SRS that tends to correlate with symptom severity in the patient. Our studies aim to pharmacologically manipulate polyamine metabolism to correct this polyamine imbalance and investigate the potential of this approach as a therapeutic strategy for affected individuals. Here we report the use of difluoromethylornithine (DFMO; eflornithine), an FDA-approved inhibitor of polyamine biosynthesis, in re-establishing normal spermidine-to-spermine ratios in SRS patient cells. Through mechanistic studies, we demonstrate that, while reducing spermidine biosynthesis, DFMO also stimulates the conversion of existing spermidine into spermine in cell lines with hypomorphic variants of SMS. Further, DFMO treatment induces a compensatory uptake of exogenous polyamines, including spermine and spermine mimetics, cooperatively reducing spermidine and increasing spermine levels. In a Drosophila SRS model characterized by reduced lifespan, adding DFMO to the feed extended lifespan. As nearly all known SRS patient mutations are hypomorphic, these studies form a foundation for future translational studies with significant therapeutic potential.
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Holbert CE, Foley JR, Stewart TM, Walker MJ, Bruckheimer E, Simpson JK, Casero RA. Abstract 4944: Evaluating the efficacy of spermine analogue ivospemin (SBP-101) in combination with chemotherapy in ovarian cancer. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-4944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
Polyamines are small cationic alkylamines that play critical roles in essential cellular processes governing growth and proliferation. As such, cancers are fully reliant on increased polyamine pools maintained through dysregulation of polyamine metabolism. Pharmaceutical modulation of polyamine metabolism is a promising avenue in cancer therapeutics and has been attempted with enzyme inhibitors, including DFMO (difluoromethylornithine), and polyamine analogues. Ivospemin is a spermine analogue that has shown efficacy in slowing pancreatic and ovarian tumor progression both in vitro and in vivo and demonstrated encouraging results in pancreatic cancer clinical trials. We have shown that ivospemin decreases polyamine content through depression of the activity of the polyamine biosynthetic enzyme ornithine decarboxylase (ODC) in a variety of cancer cell lines. Treatment of the VDID8+ murine ovarian cancer model with ivospemin resulted in a marked increase in survival. Here we examine the potential of combining ivospemin and chemotherapeutic agents that are used to treat cisplatin-resistant ovarian cancer. Treatment with gemcitabine, topotecan, and doxorubicin increased the in vitro toxicity of ivospemin, while paclitaxel and docetaxel did not have any added benefit over ivospemin alone. Using the VDID8+ model, we further evaluated the efficacy of ivospemin in combination with gemcitabine, topotecan, and doxorubicin in vivo. Ascites fluid was used as a marker of tumor burden and evaluated for polyamine content. Addition of ivospemin improved the survival of mice treated with any of the three chemotherapeutics. The ivospemin and doxorubicin combination mice had the greatest median survival time; this combination is being further evaluated in mechanistic studies and additional murine studies. Ovarian cancers have extremely immunosuppressive tumor microenvironments (TME) and metabolic reprogramming of the TME to reduce immunosuppressive phenotypes is a promising approach for treatment. Sustained elevation of polyamine levels supports an immunosuppressive TME, and evidence suggests that pharmacologic depletion of polyamines may reduce immunosuppressive phenotypes. DFMO treatment in the immunosuppressive VDID8+ model influences the immune cells of the TME, and we therefore are investigating the combination of ivospemin and DFMO in ovarian cancer. In addition to the cooperativity of ivospemin and chemotherapeutic agents, we have observed a cooperative antiproliferative response in ovarian cancer cells following DFMO and ivospemin cotreatment. Together, these studies suggest the potential of polyamine modulation by ivospemin and DFMO in combination with standard of care chemotherapy. Future studies will determine influences on the immune microenvironment and will evaluate cooperativity between ivospemin, DFMO, and chemotherapy.
Citation Format: Cassandra E. Holbert, Jackson R. Foley, Tracy Murray Stewart, Michael J. Walker, Elizabeth Bruckheimer, Jennifer K. Simpson, Robert A. Casero. Evaluating the efficacy of spermine analogue ivospemin (SBP-101) in combination with chemotherapy in ovarian cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4944.
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Tao X, Liu J, Diaz-Perez Z, Foley JR, Stewart TM, Casero RA, Zhai RG. Reduction of Spermine Synthase Suppresses Tau Accumulation Through Autophagy Modulation in Tauopathy. bioRxiv 2023:2023.03.17.533015. [PMID: 36993333 PMCID: PMC10055309 DOI: 10.1101/2023.03.17.533015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Tauopathy, including Alzheimer Disease (AD), is characterized by Tau protein accumulation and autophagy dysregulation. Emerging evidence connects polyamine metabolism with the autophagy pathway, however the role of polyamines in Tauopathy remains unclear. In the present study we investigated the role of spermine synthase (SMS) in autophagy regulation and tau protein processing in Drosophila and human cellular models of Tauopathy. Our previous study showed that Drosophila spermine synthase (dSms) deficiency impairs lysosomal function and blocks autophagy flux. Interestingly, partial loss-of-function of SMS in heterozygous dSms flies extends lifespan and improves the climbing performance of flies with human Tau (hTau) overexpression. Mechanistic analysis showed that heterozygous loss-of-function mutation of dSms reduces hTau protein accumulation through enhancing autophagic flux. Measurement of polyamine levels detected a mild elevation of spermidine in flies with heterozygous loss of dSms. SMS knock-down in human neuronal or glial cells also upregulates autophagic flux and reduces Tau protein accumulation. Proteomics analysis of postmortem brain tissue from AD patients showed a significant albeit modest elevation of SMS protein level in AD-relevant brain regions compared to that of control brains consistently across several datasets. Taken together, our study uncovers a correlation between SMS protein level and AD pathogenesis and reveals that SMS reduction upregulates autophagy, promotes Tau clearance, and reduces Tau protein accumulation. These findings provide a new potential therapeutic target of Tauopathy.
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Affiliation(s)
- Xianzun Tao
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Jiaqi Liu
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Zoraida Diaz-Perez
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Jackson R Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - Robert A Casero
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - R Grace Zhai
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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Colonna MB, Moss T, Mokashi S, Srikanth S, Jones JR, Foley JR, Skinner C, Lichty A, Kocur A, Wood T, Stewart TM, Casero Jr. RA, Flanagan-Steet H, Edison AS, Lyons MJ, Steet R. Functional assessment of homozygous ALDH18A1 variants reveals alterations in amino acid and antioxidant metabolism. Hum Mol Genet 2023; 32:732-744. [PMID: 36067040 PMCID: PMC9941824 DOI: 10.1093/hmg/ddac226] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/08/2022] [Accepted: 09/01/2022] [Indexed: 11/13/2022] Open
Abstract
Mono- and bi-allelic variants in ALDH18A1 cause a spectrum of human disorders associated with cutaneous and neurological findings that overlap with both cutis laxa and spastic paraplegia. ALDH18A1 encodes the bifunctional enzyme pyrroline-5-carboxylate synthetase (P5CS) that plays a role in the de novo biosynthesis of proline and ornithine. Here we characterize a previously unreported homozygous ALDH18A1 variant (p.Thr331Pro) in four affected probands from two unrelated families, and demonstrate broad-based alterations in amino acid and antioxidant metabolism. These four patients exhibit variable developmental delay, neurological deficits and loose skin. Functional characterization of the p.Thr331Pro variant demonstrated a lack of any impact on the steady-state level of the P5CS monomer or mitochondrial localization of the enzyme, but reduced incorporation of the monomer into P5CS oligomers. Using an unlabeled NMR-based metabolomics approach in patient fibroblasts and ALDH18A1-null human embryonic kidney cells expressing the variant P5CS, we identified reduced abundance of glutamate and several metabolites derived from glutamate, including proline and glutathione. Biosynthesis of the polyamine putrescine, derived from ornithine, was also decreased in patient fibroblasts, highlighting the functional consequence on another metabolic pathway involved in antioxidant responses in the cell. RNA sequencing of patient fibroblasts revealed transcript abundance changes in several metabolic and extracellular matrix-related genes, adding further insight into pathogenic processes associated with impaired P5CS function. Together these findings shed new light on amino acid and antioxidant pathways associated with ALDH18A1-related disorders, and underscore the value of metabolomic and transcriptomic profiling to discover new pathways that impact disease pathogenesis.
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Affiliation(s)
- Maxwell B Colonna
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Tonya Moss
- Greenwood Genetic Center, Greenwood, SC 29646, USA
| | | | | | | | - Jackson R Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine; Baltimore, MD 21287, USA
| | | | - Angie Lichty
- Greenwood Genetic Center, Greenwood, SC 29646, USA
| | | | - Tim Wood
- Department of Pathology and Laboratory Medicine, Children’s Hospital Colorado, Aurora, CO 80045, USA
| | - Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine; Baltimore, MD 21287, USA
| | - Robert A Casero Jr.
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine; Baltimore, MD 21287, USA
| | | | - Arthur S Edison
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
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Akinyele O, Munir A, Johnson MA, Perez MS, Gao Y, Foley JR, Wu Y, Murray-Stewart T, Casero RA, Bayir H, Kemaladewi DU. Impaired polyamine metabolism causes behavioral and neuroanatomical defects in a novel mouse model of Snyder-Robinson Syndrome. bioRxiv 2023:2023.01.15.524155. [PMID: 36711956 PMCID: PMC9882240 DOI: 10.1101/2023.01.15.524155] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Polyamines (putrescine, spermidine, and spermine) are essential molecules for normal cellular functions and are subject to strict metabolic regulation. Mutations in the gene encoding spermine synthase (SMS) lead to accumulation of spermidine in an X-linked recessive disorder known as Snyder-Robinson syndrome (SRS). Presently, no treatments exist for this rare disease that manifests with a spectrum of symptoms including intellectual disability, developmental delay, thin habitus, and low muscle tone. The development of therapeutic interventions for SRS will require a suitable disease-specific animal model that recapitulates many of the abnormalities observed in patients. Here, we characterize the molecular, behavioral, and neuroanatomical features of a mouse model with a missense mutation in Sms gene that results in a glycine-to-serine substitution at position 56 (G56S) of the SMS protein. Mice harboring this mutation exhibit a complete loss of SMS protein and elevated spermidine/spermine ratio in skeletal muscles and the brain. In addition, the G56S mice demonstrate increased anxiety, impaired learning, and decreased explorative behavior in fear conditioning, Morris water maze, and open field tests, respectively. Furthermore, these mice failed to gain weight over time and exhibit abnormalities in brain structure and bone density. Transcriptomic analysis of the cerebral cortex revealed downregulation of genes associated with mitochondrial oxidative phosphorylation and ribosomal protein synthesis. Our findings also revealed impaired mitochondrial bioenergetics in fibroblasts isolated from the G56S mice, indicating a correlation between these processes in the affected mice. Collectively, our findings establish the first in-depth characterization of an SRS preclinical mouse model that identifies cellular processes that could be targeted for future therapeutic development.
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Affiliation(s)
- Oluwaseun Akinyele
- Div. of Genetic and Genomic Medicine, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Anushe Munir
- Div. of Genetic and Genomic Medicine, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, USA
- Dept. of Human Genetics, School of Public Health, University of Pittsburgh, Pittsburgh, USA
| | - Marie A. Johnson
- Div. of Genetic and Genomic Medicine, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Megan S. Perez
- Div. of Genetic and Genomic Medicine, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, USA
- Dept. of Human Genetics, School of Public Health, University of Pittsburgh, Pittsburgh, USA
| | - Yuan Gao
- Children’s Neuroscience Institute, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Jackson R. Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Yijen Wu
- Dept. of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Tracy Murray-Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Robert A. Casero
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Hulya Bayir
- Children’s Neuroscience Institute, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Dwi U. Kemaladewi
- Div. of Genetic and Genomic Medicine, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, USA
- Dept. of Human Genetics, School of Public Health, University of Pittsburgh, Pittsburgh, USA
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10
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Steimbach RR, Herbst-Gervasoni CJ, Lechner S, Murray Stewart T, Klinke G, Ridinger J, Géraldy MNE, Tihanyi G, Foley JR, Uhrig U, Kuster B, Poschet G, Casero RA, Médard G, Oehme I, Christianson DW, Gunkel N, Miller AK. Aza-SAHA Derivatives Are Selective Histone Deacetylase 10 Chemical Probes That Inhibit Polyamine Deacetylation and Phenocopy HDAC10 Knockout. J Am Chem Soc 2022; 144:18861-18875. [PMID: 36200994 PMCID: PMC9588710 DOI: 10.1021/jacs.2c05030] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the first well-characterized selective chemical probe for histone deacetylase 10 (HDAC10) with unprecedented selectivity over other HDAC isozymes. HDAC10 deacetylates polyamines and has a distinct substrate specificity, making it unique among the 11 zinc-dependent HDAC hydrolases. Taking inspiration from HDAC10 polyamine substrates, we systematically inserted an amino group ("aza-scan") into the hexyl linker moiety of the approved drug Vorinostat (SAHA). This one-atom replacement (C→N) transformed SAHA from an unselective pan-HDAC inhibitor into a specific HDAC10 inhibitor. Optimization of the aza-SAHA structure yielded the HDAC10 chemical probe DKFZ-748, with potency and selectivity demonstrated by cellular and biochemical target engagement, as well as thermal shift assays. Cocrystal structures of our aza-SAHA derivatives with HDAC10 provide a structural rationale for potency, and chemoproteomic profiling confirmed exquisite cellular HDAC10-selectivity of DKFZ-748 across the target landscape of HDAC drugs. Treatment of cells with DKFZ-748, followed by quantification of selected polyamines, validated for the first time the suspected cellular function of HDAC10 as a polyamine deacetylase. Finally, in a polyamine-limiting in vitro tumor model, DKFZ-748 showed dose-dependent growth inhibition of HeLa cells. We expect DKFZ-748 and related probes to enable further studies on the enigmatic biology of HDAC10 and acetylated polyamines in both physiological and pathological settings.
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Affiliation(s)
- Raphael R. Steimbach
- Cancer Drug Development, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Biosciences Faculty, Heidelberg University, 69120, Heidelberg, Germany
| | - Corey J. Herbst-Gervasoni
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, 19104-6323, USA
| | - Severin Lechner
- Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354, Freising, Germany
| | - Tracy Murray Stewart
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21231, USA
| | - Glynis Klinke
- Center for Organismal Studies (COS), Heidelberg University, 69120, Heidelberg, Germany
| | - Johannes Ridinger
- Clinical Cooperation Unit Pediatric Oncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Hopp Children’s Cancer Center Heidelberg (KiTZ), 69120, Heidelberg, Germany
| | - Magalie N. E. Géraldy
- Cancer Drug Development, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Gergely Tihanyi
- Cancer Drug Development, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Jackson R. Foley
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21231, USA
| | - Ulrike Uhrig
- Chemical Biology Core Facility, European Molecular Biology Laboratory (EMBL), 69117, Heidelberg, Germany
| | - Bernhard Kuster
- Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354, Freising, Germany
| | - Gernot Poschet
- Center for Organismal Studies (COS), Heidelberg University, 69120, Heidelberg, Germany
| | - Robert A. Casero
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21231, USA
| | - Guillaume Médard
- Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354, Freising, Germany
| | - Ina Oehme
- Clinical Cooperation Unit Pediatric Oncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Hopp Children’s Cancer Center Heidelberg (KiTZ), 69120, Heidelberg, Germany
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - David W. Christianson
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, 19104-6323, USA
| | - Nikolas Gunkel
- Cancer Drug Development, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- German Cancer Consortium (DKTK), 69120, Heidelberg, Germany
| | - Aubry K. Miller
- Cancer Drug Development, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- German Cancer Consortium (DKTK), 69120, Heidelberg, Germany
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11
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Stewart TM, Foley JR, Holbert CE, Klinke G, Poschet G, Steimbach RR, Miller AK, Casero RA. Histone deacetylase 10 liberates spermidine to support polyamine homeostasis and tumor cell growth. J Biol Chem 2022; 298:102407. [PMID: 35988653 PMCID: PMC9486564 DOI: 10.1016/j.jbc.2022.102407] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/16/2022] [Accepted: 08/17/2022] [Indexed: 11/18/2022] Open
Abstract
Cytosolic histone deacetylase-10 (HDAC10) specifically deacetylates the modified polyamine N8-acetylspermidine (N8-AcSpd). Although intracellular concentrations of N8-AcSpd are low, extracellular sources can be abundant, particularly in the colonic lumen. Extracellular polyamines, including those from the diet and microbiota, can support tumor growth both locally and at distant sites. However, the contribution of N8-AcSpd in this context is unknown. We hypothesized that HDAC10, by converting N8- AcSpd to spermidine, may provide a source of this growth-supporting polyamine in circumstances of reduced polyamine biosynthesis, such as in polyamine-targeting anticancer therapies. Inhibitors of polyamine biosynthesis, including α-difluoromethylornithine (DFMO), inhibit tumor growth, but compensatory uptake of extracellular polyamines has limited their clinical success. Combining DFMO with inhibitors of polyamine uptake have improved the antitumor response. However, acetylated polyamines may use different transport machinery than the parent molecules. Here, we use CRISPR/Cas9-mediated HDAC10-knockout cell lines and HDAC10-specific inhibitors to investigate the contribution of HDAC10 in maintaining tumor cell proliferation. We demonstrate inhibition of cell growth by DFMO-associated polyamine depletion is successfully rescued by exogenous N8-AcSpd (at physiological concentrations), which is converted to spermidine and spermine, only in cell lines with HDAC10 activity. Furthermore, we show loss of HDAC10 prevents both restoration of polyamine levels and growth rescue, implicating HDAC10 in supporting polyamine-associated tumor growth. These data suggest the utility of HDAC10-specific inhibitors as an antitumor strategy that may have value in improving the response to polyamine-blocking therapies. Additionally, the cell-based assay developed in this study provides an inexpensive, high-throughput method of screening potentially selective HDAC10 inhibitors.
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Affiliation(s)
- Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
| | - Jackson R Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Cassandra E Holbert
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Glynis Klinke
- Metabolomics Core Technology Platform, Center for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Gernot Poschet
- Metabolomics Core Technology Platform, Center for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Raphael R Steimbach
- Biosciences Faculty, Heidelberg University, Heidelberg, Germany; Cancer Drug Development, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Aubry K Miller
- Cancer Drug Development, German Cancer Research Center (DKFZ), Heidelberg, Germany; German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Robert A Casero
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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12
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Tao X, Zhu Y, Diaz-Perez Z, Yu SH, Foley JR, Stewart TM, Casero RA, Steet R, Zhai RG. Phenylbutyrate modulates polyamine acetylase and ameliorates Snyder-Robinson syndrome in a Drosophila model and patient cells. JCI Insight 2022; 7:e158457. [PMID: 35801587 PMCID: PMC9310527 DOI: 10.1172/jci.insight.158457] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/20/2022] [Indexed: 11/26/2022] Open
Abstract
Polyamine dysregulation plays key roles in a broad range of human diseases from cancer to neurodegeneration. Snyder-Robinson syndrome (SRS) is the first known genetic disorder of the polyamine pathway, caused by X-linked recessive loss-of-function mutations in spermine synthase. In the Drosophila SRS model, altered spermidine/spermine balance has been associated with increased generation of ROS and aldehydes, consistent with elevated spermidine catabolism. These toxic byproducts cause mitochondrial and lysosomal dysfunction, which are also observed in cells from SRS patients. No efficient therapy is available. We explored the biochemical mechanism and discovered acetyl-CoA reduction and altered protein acetylation as potentially novel pathomechanisms of SRS. We repurposed the FDA-approved drug phenylbutyrate (PBA) to treat SRS using an in vivo Drosophila model and patient fibroblast cell models. PBA treatment significantly restored the function of mitochondria and autolysosomes and extended life span in vivo in the Drosophila SRS model. Treating fibroblasts of patients with SRS with PBA ameliorated autolysosome dysfunction. We further explored the mechanism of drug action and found that PBA downregulates the first and rate-limiting spermidine catabolic enzyme spermidine/spermine N1-acetyltransferase 1 (SAT1), reduces the production of toxic metabolites, and inhibits the reduction of the substrate acetyl-CoA. Taken together, we revealed PBA as a potential modulator of SAT1 and acetyl-CoA levels and propose PBA as a therapy for SRS and potentially other polyamine dysregulation-related diseases.
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Affiliation(s)
- Xianzun Tao
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Yi Zhu
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Zoraida Diaz-Perez
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Seok-Ho Yu
- JC Self Research Institute, Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - Jackson R. Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Robert A. Casero
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Richard Steet
- JC Self Research Institute, Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - R. Grace Zhai
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, USA
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13
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Holbert CE, Foley JR, Murray Stewart T, Casero RA. Expanded Potential of the Polyamine Analogue SBP-101 (Diethyl Dihydroxyhomospermine) as a Modulator of Polyamine Metabolism and Cancer Therapeutic. Int J Mol Sci 2022; 23:ijms23126798. [PMID: 35743239 PMCID: PMC9224330 DOI: 10.3390/ijms23126798] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 01/07/2023] Open
Abstract
Naturally occurring polyamines are absolutely required for cellular growth and proliferation. Many neoplastic cells are reliant on elevated polyamine levels and maintain these levels through dysregulated polyamine metabolism. The modulation of polyamine metabolism is thus a promising avenue for cancer therapeutics and has been attempted with numerous molecules, including enzyme inhibitors and polyamine analogues. SBP-101 (diethyl dihydroxyhomospermine) is a spermine analogue that has shown efficacy in slowing pancreatic tumor progression both in vitro and in vivo; however, the mechanisms underlying these effects remain unclear. We determined the effects of the SBP-101 treatment on a variety of cancer cell types in vitro, including lung, pancreatic, and ovarian. We evaluated the activity of enzymes involved in polyamine metabolism and the effect on intracellular polyamine pools following the SBP-101 treatment. The SBP-101 treatment produced a modest but variable increase in polyamine catabolism; however, a robust downregulation of the activity of the biosynthetic enzyme, ornithine decarboxylase (ODC), was seen across all of the cell types studied and indicates that SBP-101 likely exerts its effect predominately through the downregulation of ODC, with a minor upregulation of catabolism. Our in vitro work indicated that SBP-101 was most toxic in the tested ovarian cell lines. Therefore, we evaluated the efficacy of SBP-101 as a monotherapy in the immunosuppressive VDID8+ murine ovarian model. Mice treated with SBP-101 demonstrated a delay in tumor progression, a decrease in the overall tumor burden, and a marked increase in median survival.
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14
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Stewart TM, Steimbach RR, Foley JR, Miller AK, Casero RA. Abstract 5812: Histone deacetylase 10 supports tumor growth under polyamine-limiting conditions. Cancer Res 2022. [DOI: 10.1158/1538-7445.am2022-5812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Cytosolic histone deacetylase 10 (HDAC10) is specifically deacetylates the modified polyamine N8-acetylspermidine (N8-AcSpd). Although intracellular concentrations of N8-AcSpd are low, extracellular sources can be abundant, particularly in the colonic lumen. Extracellular polyamines, including those from the diet and microbiota, can support tumor growth both locally and at distant sites. However, the contribution of N8-AcSpd is unknown. We hypothesized that HDAC10, by converting N8-AcSpd to spermidine, may provide a source of this growth-supporting polyamine in circumstances of reduced polyamine biosynthesis, such as in polyamine-targeting, anticancer therapies. Inhibitors of polyamine biosynthesis, such as difluoromethylornithine (DFMO), inhibit tumor growth but with compensatory uptake of extracellular polyamines that have limited their clinical success. Combining DFMO with inhibitors of polyamine uptake have improved the antitumor response. However, acetylated polyamines may use different transport machinery than the parent molecules. The current study uses CRISPR/Cas9-mediated HDAC10-knockout cell lines and recently developed, selective HDAC10 inhibitors to investigate the contribution of HDAC10 in maintaining tumor cell proliferation. Inhibition of cell growth by DFMO-associated polyamine depletion is successfully rescued by the provision of physiological concentrations of exogenous N8-AcSpd, which is converted to spermidine and spermine, only in cell lines with HDAC10 activity. Loss of HDAC10 prevents both restoration of polyamine levels and growth rescue, implicating HDAC10 in supporting polyamine-associated tumor growth. These data suggest the utility of HDAC10-specific inhibitors as an antitumor strategy that may have particular value in improving the response to polyamine-blocking therapies.
Citation Format: Tracy Murray Stewart, Raphael R. Steimbach, Jackson R. Foley, Aubry K. Miller, Robert A. Casero. Histone deacetylase 10 supports tumor growth under polyamine-limiting conditions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5812.
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15
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Holbert CE, Dunworth M, Foley JR, Dunston TT, Stewart TM, Casero RA. Autophagy induction by exogenous polyamines is an artifact of bovine serum amine oxidase activity in culture serum. J Biol Chem 2020; 295:9061-9068. [PMID: 32430398 PMCID: PMC7335804 DOI: 10.1074/jbc.ra120.013867] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [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: 04/13/2020] [Revised: 05/18/2020] [Indexed: 11/06/2022] Open
Abstract
Polyamines are small polycationic alkylamines involved in many fundamental cellular processes, including proliferation, nucleic acid synthesis, apoptosis, and protection from oxidative damage. It has been proposed that in addition to these functions, elevated levels of polyamines promote longevity in various biological systems, including yeast, Drosophila, and murine models. A series of in vitro mechanistic studies by multiple investigators has led to the conclusion that addition of exogenous spermidine promotes longevity through autophagy induction; however, these experiments were confounded by the use of mammalian cell culture systems supplemented with fetal bovine serum. Using cell viability assays, LC3B immunoblots, and live-cell fluorescence microscopy, we report here that in the presence of ruminant serum, exogenously added polyamines are quickly oxidized by the copper-containing bovine serum amine oxidase. This polyamine oxidation resulted in the production of harmful byproducts including hydrogen peroxide, ammonia, and reactive aldehydes. Our data demonstrate that it is critically important to prevent confounding bovine serum amine oxidase-induced cytotoxicity in mechanistic studies of the roles of polyamines in autophagy.
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Affiliation(s)
- Cassandra E Holbert
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Matthew Dunworth
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Jackson R Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Tiffany T Dunston
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Robert A Casero
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
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16
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Geck RC, Foley JR, Murray Stewart T, Asara JM, Casero RA, Toker A. Inhibition of the polyamine synthesis enzyme ornithine decarboxylase sensitizes triple-negative breast cancer cells to cytotoxic chemotherapy. J Biol Chem 2020; 295:6263-6277. [PMID: 32139506 PMCID: PMC7212655 DOI: 10.1074/jbc.ra119.012376] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [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: 12/18/2019] [Revised: 02/28/2020] [Indexed: 12/19/2022] Open
Abstract
Treatment of patients with triple-negative breast cancer (TNBC) is limited by a lack of effective molecular therapies targeting this disease. Recent studies have identified metabolic alterations in cancer cells that can be targeted to improve responses to standard-of-care chemotherapy regimens. Using MDA-MB-468 and SUM-159PT TNBC cells, along with LC-MS/MS and HPLC metabolomics profiling, we found here that exposure of TNBC cells to the cytotoxic chemotherapy drugs cisplatin and doxorubicin alter arginine and polyamine metabolites. This alteration was because of a reduction in the levels and activity of a rate-limiting polyamine biosynthetic enzyme, ornithine decarboxylase (ODC). Using gene silencing and inhibitor treatments, we determined that the reduction in ODC was mediated by its negative regulator antizyme, targeting ODC to the proteasome for degradation. Treatment with the ODC inhibitor difluoromethylornithine (DFMO) sensitized TNBC cells to chemotherapy, but this was not observed in receptor-positive breast cancer cells. Moreover, TNBC cell lines had greater sensitivity to single-agent DFMO, and ODC levels were elevated in TNBC patient samples. The alterations in polyamine metabolism in response to chemotherapy, as well as DFMO-induced preferential sensitization of TNBC cells to chemotherapy, reported here suggest that ODC may be a targetable metabolic vulnerability in TNBC.
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Affiliation(s)
- Renee C Geck
- Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215
- Harvard Medical School, Boston, Massachusetts 02115
| | - Jackson R Foley
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - John M Asara
- Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215
| | - Robert A Casero
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - Alex Toker
- Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215
- Harvard Medical School, Boston, Massachusetts 02115
- Ludwig Center at Harvard, Boston, Massachusetts 02115
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17
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Murray Stewart T, Khomutov M, Foley JR, Guo X, Holbert CE, Dunston TT, Schwartz CE, Gabrielson K, Khomutov A, Casero RA. ( R, R)-1,12-Dimethylspermine can mitigate abnormal spermidine accumulation in Snyder-Robinson syndrome. J Biol Chem 2020; 295:3247-3256. [PMID: 31996374 DOI: 10.1074/jbc.ra119.011572] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 01/21/2020] [Indexed: 11/06/2022] Open
Abstract
Snyder-Robinson syndrome (SRS) is an X-linked intellectual disability syndrome caused by a loss-of-function mutation in the spermine synthase (SMS) gene. Primarily affecting males, the main manifestations of SRS include osteoporosis, hypotonic stature, seizures, cognitive impairment, and developmental delay. Because there is no cure for SRS, treatment plans focus on alleviating symptoms rather than targeting the underlying causes. Biochemically, the cells of individuals with SRS accumulate excess spermidine, whereas spermine levels are reduced. We recently demonstrated that SRS patient-derived lymphoblastoid cells are capable of transporting exogenous spermine and its analogs into the cell and, in response, decreasing excess spermidine pools to normal levels. However, dietary supplementation of spermine does not appear to benefit SRS patients or mouse models. Here, we investigated the potential use of a metabolically stable spermine mimetic, (R,R)-1,12-dimethylspermine (Me2SPM), to reduce the intracellular spermidine pools of SRS patient-derived cells. Me2SPM can functionally substitute for the native polyamines in supporting cell growth while stimulating polyamine homeostatic control mechanisms. We found that both lymphoblasts and fibroblasts from SRS patients can accumulate Me2SPM, resulting in significantly decreased spermidine levels with no adverse effects on growth. Me2SPM administration to mice revealed that Me2SPM significantly decreases spermidine levels in multiple tissues. Importantly, Me2SPM was detectable in brain tissue, the organ most affected in SRS, and was associated with changes in polyamine metabolic enzymes. These findings indicate that the (R,R)-diastereomer of 1,12-Me2SPM represents a promising lead compound in developing a treatment aimed at targeting the molecular mechanisms underlying SRS pathology.
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Affiliation(s)
- Tracy Murray Stewart
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | - Maxim Khomutov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Jackson R Foley
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | - Xin Guo
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Cassandra E Holbert
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | - Tiffany T Dunston
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | | | - Kathleen Gabrielson
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Alexey Khomutov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Robert A Casero
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, Maryland 21287.
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18
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Chew PG, Dobson LE, Garg P, Richards FJL, Foley JR, Fent GJ, Brown LAE, Saunderson CED, Das A, Kidambi A, Levelt E, Swoboda PP, Dall'armellina E, Plein S, Greenwood JP. P589Assessment of cardiac reverse remodelling following mitral valve repair and mitral valve replacement in degenerative mitral regurgitation: a cardiovascular magnetic resonance study. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz747.0198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Mitral valve (MV) repair is currently recommended over replacement (1). The guidelines suggesting this are however based on historic evidence which compared outdated techniques of MV replacement. Recent data cast doubts on its validity in the current era of chordal-preservation techniques in MV replacement.
Purpose
Using cardiovascular magnetic resonance (CMR) imaging, this study aimed to assess the impact of MV repair and MV replacement on cardiac left ventricular (LV) reverse remodelling.
Methods
65 patients with moderate-severe and severe mitral regurgitation (MR) were prospectively recruited. Of these, 37 patients (59% men, 65±15 years) to date with paired CMR scans at baseline and at 6 months were evaluated. Patients either underwent MV repair (n=9), MV replacement (n=10) or watchful waiting (n=18). The CMR protocol included cines for left ventricle (LV), left atria (LA), and aortic flow assessment. The LA and LV parameters, and MR fraction were analysed.
Results
At 6 months, both the MV repair and replacement groups exhibited a reduction in LV end-diastolic volume (LVEDV) and LA volumes when compared to the control group. The indexed LVEDV decreased significantly from 129±33ml/m2 to 99±37ml/m2, p<0.001 in the repair group, from 118±24ml/m2 to 90±26ml/m2, p<0.001 in the replacement group and remained unchanged in the control group 115±25ml/m2 to 113±25ml/m2, p=0.53. The absolute reduction in indexed LVEDV was not significantly different between the repair and replacement groups (−30±15ml/m2 vs −29±19ml/m2, repair vs replacement, p=1.00). Similarly, both surgical groups also sustained an equal degree of LA size reduction (−42±26ml/m2 vs −36±23ml/m2, repair vs replacement; p=1.00). There was a decline in the global postoperative LV ejection fraction (Table 1). The degree of reduction in LV ejection fraction however did not differ between the repair and replacement group (−9±6% vs −6±8%, repair vs replacement; p=1.00). Those undergoing surgery experienced a significant reduction in their MR severity, although those with replacement had a more effective reduction in MR severity (MR fraction for repair: 47±9% to 15±10%, p<0.001 vs replacement: 41±13% to 5±4%, p<0.001).
Conclusion
MV surgery leads to atrial and left ventricular reverse remodelling, and a decline in global LV ejection fraction. In this small series, MV replacement with chordal preservation showed similar cardiac reverse remodelling benefits to MV repair. Although residual MR is often seen following repair, this did not lead to less favourable cardiac reverse remodelling.
Acknowledgement/Funding
Leeds NIHR infrastructure
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Affiliation(s)
- P G Chew
- University of Leeds, Leeds, United Kingdom
| | - L E Dobson
- University of Leeds, Leeds, United Kingdom
| | - P Garg
- University of Leeds, Leeds, United Kingdom
| | | | - J R Foley
- University of Leeds, Leeds, United Kingdom
| | - G J Fent
- University of Leeds, Leeds, United Kingdom
| | | | | | - A Das
- University of Leeds, Leeds, United Kingdom
| | - A Kidambi
- University of Leeds, Leeds, United Kingdom
| | - E Levelt
- University of Leeds, Leeds, United Kingdom
| | | | | | - S Plein
- University of Leeds, Leeds, United Kingdom
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19
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Travers M, Brown SM, Dunworth M, Holbert CE, Wiehagen KR, Bachman KE, Foley JR, Stone ML, Baylin SB, Casero RA, Zahnow CA. DFMO and 5-Azacytidine Increase M1 Macrophages in the Tumor Microenvironment of Murine Ovarian Cancer. Cancer Res 2019; 79:3445-3454. [PMID: 31088836 DOI: 10.1158/0008-5472.can-18-4018] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/25/2019] [Accepted: 05/07/2019] [Indexed: 12/12/2022]
Abstract
Although ovarian cancer has a low incidence rate, it remains the most deadly gynecologic malignancy. Previous work has demonstrated that the DNMTi 5-Azacytidine (5AZA-C) activates type I interferon signaling to increase IFNγ+ T cells and natural killer (NK) cells and reduce the percentage of macrophages in the tumor microenvironment. To improve the efficacy of epigenetic therapy, we hypothesized that the addition of α-difluoromethylornithine (DFMO), an ornithine decarboxylase inhibitor, may further decrease immunosuppressive cell populations improving outcome. We tested this hypothesis in an immunocompetent mouse model for ovarian cancer and found that in vivo, 5AZA-C and DFMO, either alone or in combination, significantly increased survival, decreased tumor burden, and caused recruitment of activated (IFNγ+) CD4+ T cells, CD8+ T cells, and NK cells. The combination therapy had a striking increase in survival when compared with single-agent treatment, despite a smaller difference in recruited lymphocytes. Instead, combination therapy led to a significant decrease in immunosuppressive cells such as M2 polarized macrophages and an increase in tumor-killing M1 macrophages. In this model, depletion of macrophages with a CSF1R-blocking antibody reduced the efficacy of 5AZA-C + DFMO treatment and resulted in fewer M1 macrophages in the tumor microenvironment. These observations suggest our novel combination therapy modifies macrophage polarization in the tumor microenvironment, recruiting M1 macrophages and prolonging survival. SIGNIFICANCE: Combined epigenetic and polyamine-reducing therapy stimulates M1 macrophage polarization in the tumor microenvironment of an ovarian cancer mouse model, resulting in decreased tumor burden and prolonged survival.
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Affiliation(s)
- Meghan Travers
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | - Stephen M Brown
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | - Matthew Dunworth
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | - Cassandra E Holbert
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | | | | | - Jackson R Foley
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | - Meredith L Stone
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.,Division of Hematology-Oncology, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Stephen B Baylin
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | - Robert A Casero
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.
| | - Cynthia A Zahnow
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.
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20
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Swoboda PP, Garg P, Foley JR, Fent GJ, Brown LA, Chew PG, Saunderson CE, Dall'armellina E, Greenwood JP, Plein S. P5646Cardiac effects of complete enforced detraining assessed by cardiovascular magnetic resonance. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p5646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- P P Swoboda
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
| | - P Garg
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
| | - J R Foley
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
| | - G J Fent
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
| | - L A Brown
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
| | - P G Chew
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
| | - C E Saunderson
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
| | - E Dall'armellina
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
| | - J P Greenwood
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
| | - S Plein
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom
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