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Lim EW, Metallo CM. Tracing the Diverse Paths of One-Carbon Metabolism in Cancer and Beyond. Cold Spring Harb Perspect Med 2024:a041533. [PMID: 38503499 DOI: 10.1101/cshperspect.a041533] [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: 03/21/2024]
Abstract
One-carbon (1C) metabolism is a network of biochemical reactions distributed across organelles that delivers folate-activated 1C units to support macromolecule synthesis, methylation, and reductive homeostasis. Fluxes through these pathways are up-regulated in highly proliferative cancer cells, and anti-folates, which target enzymes within the 1C pathway, have long been used in the treatment of cancer. In this work, we review fundamental aspects of 1C metabolism and place it in context with other biosynthetic and redox pathways, such that 1C metabolism acts to bridge pathways across compartments. We further discuss the importance of stable-isotope-tracing techniques combined with mass spectrometry analysis to study 1C metabolism and conclude by highlighting therapeutic approaches that could exploit cancer cells' dependency on 1C metabolism.
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Affiliation(s)
- Esther W Lim
- Department of Molecular and Cell Biology, Salk Institute for Biological Studies, La Jolla, California 92037, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, USA
| | - Christian M Metallo
- Department of Molecular and Cell Biology, Salk Institute for Biological Studies, La Jolla, California 92037, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, USA
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2
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Perea-Gil I, Seeger T, Bruyneel AAN, Termglinchan V, Monte E, Lim EW, Vadgama N, Furihata T, Gavidia AA, Arthur Ataam J, Bharucha N, Martinez-Amador N, Ameen M, Nair P, Serrano R, Kaur B, Feyen DAM, Diecke S, Snyder MP, Metallo CM, Mercola M, Karakikes I. Serine biosynthesis as a novel therapeutic target for dilated cardiomyopathy. Eur Heart J 2022; 43:3477-3489. [PMID: 35728000 PMCID: PMC9794189 DOI: 10.1093/eurheartj/ehac305] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 04/14/2022] [Accepted: 05/24/2022] [Indexed: 12/30/2022] Open
Abstract
AIMS Genetic dilated cardiomyopathy (DCM) is a leading cause of heart failure. Despite significant progress in understanding the genetic aetiologies of DCM, the molecular mechanisms underlying the pathogenesis of familial DCM remain unknown, translating to a lack of disease-specific therapies. The discovery of novel targets for the treatment of DCM was sought using phenotypic sceening assays in induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) that recapitulate the disease phenotypes in vitro. METHODS AND RESULTS Using patient-specific iPSCs carrying a pathogenic TNNT2 gene mutation (p.R183W) and CRISPR-based genome editing, a faithful DCM model in vitro was developed. An unbiased phenotypic screening in TNNT2 mutant iPSC-derived cardiomyocytes (iPSC-CMs) with small molecule kinase inhibitors (SMKIs) was performed to identify novel therapeutic targets. Two SMKIs, Gö 6976 and SB 203580, were discovered whose combinatorial treatment rescued contractile dysfunction in DCM iPSC-CMs carrying gene mutations of various ontologies (TNNT2, TTN, LMNA, PLN, TPM1, LAMA2). The combinatorial SMKI treatment upregulated the expression of genes that encode serine, glycine, and one-carbon metabolism enzymes and significantly increased the intracellular levels of glucose-derived serine and glycine in DCM iPSC-CMs. Furthermore, the treatment rescued the mitochondrial respiration defects and increased the levels of the tricarboxylic acid cycle metabolites and ATP in DCM iPSC-CMs. Finally, the rescue of the DCM phenotypes was mediated by the activating transcription factor 4 (ATF4) and its downstream effector genes, phosphoglycerate dehydrogenase (PHGDH), which encodes a critical enzyme of the serine biosynthesis pathway, and Tribbles 3 (TRIB3), a pseudokinase with pleiotropic cellular functions. CONCLUSIONS A phenotypic screening platform using DCM iPSC-CMs was established for therapeutic target discovery. A combination of SMKIs ameliorated contractile and metabolic dysfunction in DCM iPSC-CMs mediated via the ATF4-dependent serine biosynthesis pathway. Together, these findings suggest that modulation of serine biosynthesis signalling may represent a novel genotype-agnostic therapeutic strategy for genetic DCM.
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Affiliation(s)
- Isaac Perea-Gil
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Timon Seeger
- Department of Medicine III, University Hospital Heidelberg, Heidelberg, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Arne A N Bruyneel
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Vittavat Termglinchan
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Emma Monte
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Esther W Lim
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Nirmal Vadgama
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
| | - Takaaki Furihata
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Alexandra A Gavidia
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
| | - Jennifer Arthur Ataam
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Nike Bharucha
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Noel Martinez-Amador
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
| | - Mohamed Ameen
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Pooja Nair
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
| | - Ricardo Serrano
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Balpreet Kaur
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
| | - Dries A M Feyen
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Sebastian Diecke
- Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
| | - Michael P Snyder
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Christian M Metallo
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Mark Mercola
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Ioannis Karakikes
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
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3
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Lim EW, Handzlik MK, Trefts E, Gengatharan JM, Pondevida CM, Shaw RJ, Metallo CM. Progressive alterations in amino acid and lipid metabolism correlate with peripheral neuropathy in PolgD257A mice. Sci Adv 2021; 7:eabj4077. [PMID: 34652935 PMCID: PMC8519573 DOI: 10.1126/sciadv.abj4077] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/24/2021] [Indexed: 05/03/2023]
Abstract
Mitochondria are central to metabolic homeostasis, and progressive mitochondrial defects have diverse metabolic consequences that could drive distinct pathophysiological states. Here, we comprehensively characterized metabolic alterations in PolgD257A mice. Plasma alanine increased markedly with time, with other organic acids accumulating to a lesser extent. These changes were reflective of increased Cori and Cahill cycling in PolgD257A mice and subsequent hypoglycemia, which did not occur during normal mouse aging. Tracing with [15N]ammonium further supported this shift in amino acid metabolism with mild impairment of the urea cycle. We also measured alterations in the lipidome, observing a reduction in canonical lipids and accumulation of 1-deoxysphingolipids, which are synthesized from alanine via promiscuous serine palmitoyltransferase activity and correlate with peripheral neuropathy. Consistent with this metabolic link, PolgD257A mice exhibited thermal hypoalgesia. These results highlight the longitudinal changes that occur in intermediary metabolism upon mitochondrial impairment and identify a contributing mechanism to mitochondria-associated neuropathy.
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Affiliation(s)
- Esther W. Lim
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Michal K. Handzlik
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Elijah Trefts
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Jivani M. Gengatharan
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Carlos M. Pondevida
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Reuben J. Shaw
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Christian M. Metallo
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
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4
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Eade K, Gantner ML, Hostyk JA, Nagasaki T, Giles S, Fallon R, Harkins-Perry S, Baldini M, Lim EW, Scheppke L, Dorrell MI, Cai C, Baugh EH, Wolock CJ, Wallace M, Berlow RB, Goldstein DB, Metallo CM, Friedlander M, Allikmets R. Serine biosynthesis defect due to haploinsufficiency of PHGDH causes retinal disease. Nat Metab 2021; 3:366-377. [PMID: 33758422 PMCID: PMC8084205 DOI: 10.1038/s42255-021-00361-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 02/10/2021] [Indexed: 02/08/2023]
Abstract
Macular telangiectasia type 2 (MacTel) is a progressive, late-onset retinal degenerative disease linked to decreased serum levels of serine that elevate circulating levels of a toxic ceramide species, deoxysphingolipids (deoxySLs); however, causal genetic variants that reduce serine levels in patients have not been identified. Here we identify rare, functional variants in the gene encoding the rate-limiting serine biosynthetic enzyme, phosphoglycerate dehydrogenase (PHGDH), as the single locus accounting for a significant fraction of MacTel. Under a dominant collapsing analysis model of a genome-wide enrichment analysis of rare variants predicted to impact protein function in 793 MacTel cases and 17,610 matched controls, the PHGDH gene achieves genome-wide significance (P = 1.2 × 10-13) with variants explaining ~3.2% of affected individuals. We further show that the resulting functional defects in PHGDH cause decreased serine biosynthesis and accumulation of deoxySLs in retinal pigmented epithelial cells. PHGDH is a significant locus for MacTel that explains the typical disease phenotype and suggests a number of potential treatment options.
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Affiliation(s)
- Kevin Eade
- Lowy Medical Research Institute, La Jolla, CA, USA
| | | | - Joseph A Hostyk
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | | | - Sarah Giles
- Lowy Medical Research Institute, La Jolla, CA, USA
| | - Regis Fallon
- Lowy Medical Research Institute, La Jolla, CA, USA
| | - Sarah Harkins-Perry
- Lowy Medical Research Institute, La Jolla, CA, USA
- The Scripps Research Institute, La Jolla, CA, USA
| | - Michelle Baldini
- Department of Bioengineering, University of California, San Diego, CA, USA
| | - Esther W Lim
- Department of Bioengineering, University of California, San Diego, CA, USA
| | - Lea Scheppke
- Lowy Medical Research Institute, La Jolla, CA, USA
| | | | - Carolyn Cai
- Department of Ophthalmology, Columbia University, New York, NY, USA
| | - Evan H Baugh
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | - Charles J Wolock
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | - Martina Wallace
- Department of Bioengineering, University of California, San Diego, CA, USA
| | | | - David B Goldstein
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | | | - Martin Friedlander
- Lowy Medical Research Institute, La Jolla, CA, USA
- The Scripps Research Institute, La Jolla, CA, USA
- Scripps Clinic Medical Group, La Jolla, CA, USA
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, NY, USA.
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.
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5
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Gheller BJ, Blum JE, Lim EW, Handzlik MK, Hannah Fong EH, Ko AC, Khanna S, Gheller ME, Bender EL, Alexander MS, Stover PJ, Field MS, Cosgrove BD, Metallo CM, Thalacker-Mercer AE. Extracellular serine and glycine are required for mouse and human skeletal muscle stem and progenitor cell function. Mol Metab 2021; 43:101106. [PMID: 33122122 PMCID: PMC7691553 DOI: 10.1016/j.molmet.2020.101106] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/08/2020] [Accepted: 10/21/2020] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE Skeletal muscle regeneration relies on muscle-specific adult stem cells (MuSCs), MuSC progeny, muscle progenitor cells (MPCs), and a coordinated myogenic program that is influenced by the extracellular environment. Following injury, MPCs undergo a transient and rapid period of population expansion, which is necessary to repair damaged myofibers and restore muscle homeostasis. Certain pathologies (e.g., metabolic diseases and muscle dystrophies) and advanced age are associated with dysregulated muscle regeneration. The availability of serine and glycine, two nutritionally non-essential amino acids, is altered in humans with these pathologies, and these amino acids have been shown to influence the proliferative state of non-muscle cells. Our objective was to determine the role of serine/glycine in MuSC/MPC function. METHODS Primary human MPCs (hMPCs) were used for in vitro experiments, and young (4-6 mo) and old (>20 mo) mice were used for in vivo experiments. Serine/glycine availability was manipulated using specially formulated media in vitro or dietary restriction in vivo followed by downstream metabolic and cell proliferation analyses. RESULTS We identified that serine/glycine are essential for hMPC proliferation. Dietary restriction of serine/glycine in a mouse model of skeletal muscle regeneration lowered the abundance of MuSCs 3 days post-injury. Stable isotope-tracing studies showed that hMPCs rely on extracellular serine/glycine for population expansion because they exhibit a limited capacity for de novo serine/glycine biosynthesis. Restriction of serine/glycine to hMPCs resulted in cell cycle arrest in G0/G1. Extracellular serine/glycine was necessary to support glutathione and global protein synthesis in hMPCs. Using an aged mouse model, we found that reduced serine/glycine availability augmented intermyocellular adipocytes 28 days post-injury. CONCLUSIONS These studies demonstrated that despite an absolute serine/glycine requirement for MuSC/MPC proliferation, de novo synthesis was inadequate to support these demands, making extracellular serine and glycine conditionally essential for efficient skeletal muscle regeneration.
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Affiliation(s)
- Brandon J Gheller
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA
| | - Jamie E Blum
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA
| | - Esther W Lim
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Michal K Handzlik
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | | | - Anthony C Ko
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA
| | - Shray Khanna
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA
| | - Molly E Gheller
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA
| | - Erica L Bender
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA
| | - Matthew S Alexander
- Department of Pediatrics, Division of Neurology at the University of Alabama at Birmingham and Children's of Alabama, Birmingham, AL, USA; UAB Center for Exercise Medicine, Birmingham, AL, USA; Civitan International Research Center at the University of Alabama at Birmingham, Birmingham, AL, USA; Department of Genetics at the University of Alabama at Birmingham, Birmingham, AL, USA
| | - Patrick J Stover
- College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, USA
| | - Martha S Field
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA
| | - Benjamin D Cosgrove
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Christian M Metallo
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Anna E Thalacker-Mercer
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA; UAB Center for Exercise Medicine, Birmingham, AL, USA; Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, USA.
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6
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Abstract
Oxidation-reduction (redox) reactions are ubiquitous in biology and typically occur in specific subcellular compartments. In cells, the electron transfer between molecules and organelles is commonly facilitated by pyridine nucleotides such as nicotinamide adenine dinucleotide phosphate (NADPH) and nicotinamide adenine dinucleotide (NADH). While often taken for granted, these metabolic reactions are critically important for maintaining redox homeostasis and biochemical potentials across membranes. While 13C tracing and metabolic flux analysis (MFA) have emerged as powerful tools to study intracellular metabolism, this approach is limited when applied to pathways catalyzed in multiple cellular compartments. To address this issue, we and others have applied 2H (deuterium) tracers to observe transfer of labeled hydride anions, which accompanies electron transfer. Furthermore, we have developed a reporter system for indirectly quantifying NADPH enrichment in specific subcellular compartments. Here, we provide a detailed description of 2H tracing applications and the interrogation of mitochondrial versus cytosolic NAD(P)H metabolism in cultured mammalian cells. Specifically, we describe the generation of reporter cell lines that express epitope-tagged R132H-IDH1 or R172K-IDH2 and produce (D)2-hydroxyglutarate in a doxycycline-dependent manner. These tools and methods allow for quantitation of reducing equivalent turnover rates, the directionality of pathways present in multiple compartments, and the estimation of pathway contributions to NADPH pools.
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Affiliation(s)
- Esther W Lim
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Seth J Parker
- Department of Radiation Oncology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, USA
| | - Christian M Metallo
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA.
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA.
- Diabetes and Endocrinology Research Center, University of California San Diego, La Jolla, CA, USA.
- Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA, USA.
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7
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Rudd AK, Mittal N, Lim EW, Metallo CM, Devaraj NK. A Small Molecule Fluorogenic Probe for the Detection of Sphingosine in Living Cells. J Am Chem Soc 2020; 142:17887-17891. [DOI: 10.1021/jacs.0c06652] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Andrew K. Rudd
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Neel Mittal
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Esther W. Lim
- Department of Bioengineering, University of California San Diego, La Jolla, California 92093, United States
| | - Christian M. Metallo
- Department of Bioengineering, University of California San Diego, La Jolla, California 92093, United States
| | - Neal K. Devaraj
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
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Muthusamy T, Cordes T, Handzlik MK, You L, Lim EW, Gengatharan J, Pinto AFM, Badur MG, Kolar MJ, Wallace M, Saghatelian A, Metallo CM. Serine restriction alters sphingolipid diversity to constrain tumour growth. Nature 2020; 586:790-795. [PMID: 32788725 PMCID: PMC7606299 DOI: 10.1038/s41586-020-2609-x] [Citation(s) in RCA: 141] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 05/11/2020] [Indexed: 11/22/2022]
Abstract
Serine, glycine, and other non-essential amino acids are critical for tumor progression, and strategies to limit their availability are emerging as potential cancer therapies1–3. However, the molecular mechanisms driving this response remain unclear, and the impact on lipid metabolism is relatively unexplored. Serine palmitoyltransferase (SPT) catalyzes the de novo biosynthesis of sphingolipids but also produces non-canonical 1-deoxysphingolipids (doxSLs) when using alanine as a substrate4,5. DoxSLs accumulate in the context of SPTLC1 or SPTLC2 mutations6,7 or low serine availability8,9 to drive neuropathy, and deoxysphinganine (doxSA) has been investigated as an anti-cancer agent10. Here we exploit amino acid metabolism and SPT promiscuity to modulate the endogenous synthesis of toxic doxSLs and slow tumor progression. Anchorage-independent growth reprograms a metabolic network involving serine, alanine, and pyruvate resulting in increased susceptibility to endogenous doxSL synthesis. Targeting the mitochondrial pyruvate carrier (MPC) promotes alanine oxidation to mitigate doxSL synthesis and improves spheroid growth, while direct inhibition of doxSL synthesis drives similar phenotypes. Restriction of dietary serine/glycine potently induces accumulation of doxSLs in xenografts while decreasing tumor growth. Pharmacological modulation of SPT rescues xenograft growth on serine/glycine-restricted diets, while reduction of circulating serine by inhibition of phosphoglycerate dehydrogenase (PHGDH) leads to doxSL accumulation and mitigates tumor growth. SPT promiscuity therefore links serine and mitochondrial alanine metabolism to membrane lipid diversity, which sensitizes tumors to metabolic stress.
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Affiliation(s)
| | - Thekla Cordes
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Michal K Handzlik
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Le You
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Esther W Lim
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Jivani Gengatharan
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Antonio F M Pinto
- Mass Spectrometry Core, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Mehmet G Badur
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Matthew J Kolar
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Martina Wallace
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Christian M Metallo
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA. .,Moores Cancer Center, University of California, San Diego, La Jolla, CA, USA.
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9
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Velez DO, Ranamukhaarachchi SK, Kumar A, Modi RN, Lim EW, Engler AJ, Metallo CM, Fraley SI. 3D collagen architecture regulates cell adhesion through degradability, thereby controlling metabolic and oxidative stress. Integr Biol (Camb) 2020; 11:221-234. [PMID: 31251330 DOI: 10.1093/intbio/zyz019] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 03/08/2019] [Accepted: 05/23/2019] [Indexed: 11/14/2022]
Abstract
The collagen-rich tumor microenvironment plays a critical role in directing the migration behavior of cancer cells. 3D collagen architectures with small pores have been shown to confine cells and induce aggressive collective migration, irrespective of matrix stiffness and density. However, it remains unclear how cells sense collagen architecture and transduce this information to initiate collective migration. Here, we tune collagen architecture and analyze its effect on four core cell-ECM interactions: cytoskeletal polymerization, adhesion, contractility, and matrix degradation. From this comprehensive analysis, we deduce that matrix architecture initially modulates cancer cell adhesion strength, and that this results from architecture-induced changes to matrix degradability. That is, architectures with smaller pores are less degradable, and degradability is required for cancer cell adhesion to 3D fibrilar collagen. The biochemical consequences of this 3D low-attachment state are similar to those induced by suspension culture, including metabolic and oxidative stress. One distinction from suspension culture is the induction of collagen catabolism that occurs in 3D low-attachment conditions. Cells also upregulate Snail1 and Notch signaling in response to 3D low-attachment, which suggests a mechanism for the emergence of collective behaviors.
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Affiliation(s)
- Daniel O Velez
- Bioengineering Department, University of California San Diego, CA, USA
| | | | - Aditya Kumar
- Bioengineering Department, University of California San Diego, CA, USA
| | - Rishi N Modi
- Bioengineering Department, University of California San Diego, CA, USA
| | - Esther W Lim
- Bioengineering Department, University of California San Diego, CA, USA
| | - Adam J Engler
- Bioengineering Department, University of California San Diego, CA, USA
| | | | - Stephanie I Fraley
- Bioengineering Department, University of California San Diego, CA, USA.,Moore's Cancer Center, University of California San Diego La Jolla, CA, USA
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Ho H, Yuen JSP, Mohan P, Lim EW, Cheng CWS. Robotic transperineal prostate biopsy: pilot clinical study. Urology 2011; 78:1203-8. [PMID: 21940041 DOI: 10.1016/j.urology.2011.07.1389] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 06/08/2011] [Accepted: 07/09/2011] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To develope a robot (BioXbot) that performs mapping transperineal prostate biopsy (PB) with two perineal skin punctures under ultrasound guidance. Our pilot study's clinical endpoints were complications and its technical endpoints were the duration for each phase. METHODS This institution review board-approved prospective clinical trial included patients with indications for PB. Two urologists performed these PBs. In the lithotomy position and under general anesthesia, the transrectal biplane ultrasound probe acquired transverse images of the prostate gland. The urologist defined its boundaries and planned the biopsy. It guided the PB in 3 axes, passing through a single perineal skin puncture for each prostate side. After each biopsy, it automatically moved to the next position. The steps were repeated on the contralateral side. RESULTS Our 20 patients had a mean prostate-specific antigen of 8.4 ± 4.9 ng/mL. Two patients had 2 previous biopsies, whereas the rest had one. The mean number of biopsies taken was 28.5 ± 6.2 in a mean total procedure time of 32.5 ± 3.2 minutes. We detected 3 patients with prostate cancer with Gleason score 3 + 3. Two patients required brief bladder catheterization after their biopsy. Their prostate volumes were >50 mL and the number of biopsies taken was >30 cores. There was no mechanical failure, sepsis, bleeding per-rectal, or perineal hematoma. CONCLUSION This pilot study demonstrated BioXbot's safety and feasibility as a biopsy platform. It can potentially be used for image-guided PB and focal therapy.
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Affiliation(s)
- H Ho
- Department of Urology, Singapore General Hospital, Singapore.
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Inglis TJ, Lim EW, Lee GS, Cheong KF, Ng KS. Endogenous source of bacteria in tracheal tube and proximal ventilator breathing system in intensive care patients. Br J Anaesth 1998; 80:41-5. [PMID: 9505776 DOI: 10.1093/bja/80.1.41] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although bacteria from both the ventilator breathing system and the gastrointestinal tract have been implicated in the pathogenesis of ventilator-associated pneumonia, an endogenous source of bacteria in the proximal respiratory breathing system has yet to be demonstrated conclusively. We investigated a potential route of bacterial colonization from the stomach contents to the efferent limb of the ventilator breathing system by bacterial culture of daily specimens from six sites in 20 surgical intensive care patients. Gram-negative bacilli were isolated in a progressively increasing proportion of samples at successive sampling points, consistent with an endogenous-to-external route of spread (patients, chi-square = 14.12, P < 0.02; samples, chi-square = 106.15, P < 0.001). Identical strains of gram-negative bacilli, confirmed by REPS typing, were found at two or more sites in seven patients. In all seven, gram-negative bacilli were first isolated from a site in the patient. In none of the 20 patients was there evidence of a sequence of colonization from the ventilator tubing or Y-piece connector towards the patient. Probable colonization sequences plotted from the time of first isolation supported the proposed sequence in six patients, and in five began with the stomach contents. Isolation sequences contrary to the proposed direction of colonization involved four bacterial species and two patients, and did not extend beyond two sample sites. These findings imply that the retrograde route of bacterial colonization of the ventilated lung extends into the proximal respiratory breathing system and may help to identify additional targets for preventive intervention.
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Affiliation(s)
- T J Inglis
- Division of Microbiology and Infectious Diseases, Western Australian Centre for Pathology and Medical Research, Nedlands, Australia
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Mendis L, Kumarasinghe G, Chow C, Liew HY, Ramachandran NP, Jayawardene K, Thong KT, Howe JL, Lim EW, Zaman V. Bacteria, viruses, yeasts and protozoans associated with diarrheal disease in Singapore. Pathology 1995; 27:48-52. [PMID: 7603751 PMCID: PMC7131593 DOI: 10.1080/00313029500169452] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Labile toxin producing enterotoxic E. coli (ETEC) were the commonest pathogen isolated from diarrheal stools of hospitalized children (21%) and adults (26%) in Singapore. Salmonellas ranked a close second in children (19%). Other bacterial pathogens were isolated from less than 5% of subjects. Blastocystis hominis was detected in 4.3% of diarrheal stools when a simple sedimentation technique was used. Cryptosporidium was not detected at all. An analysis of yeast counts in smears of diarrheal and non-diarrheal stools suggested they were etiologically associated with at least 6% of diarrhea in children and 19% in adults. Testing for rotaviruses by Latex agglutination and for adenovirus by electronmicroscopy showed an association with 6 per cent and 3 per cent diarrhea respectively. The study highlighted a need for: case control studies on ETEC and B. hominis; studies on the epidemiology of diarrhea by yeasts; establishing the true incidence of adenovirus diarrhea; studies on the prevalence and seasonality of rotavirus infection in Singapore.
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Affiliation(s)
- L Mendis
- Faculty of Medicine, University of Colombo, Sri Lanka
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Lim EW, Meers PD. The specificity of a rapid method of assay for the presence of Legionella species in water. Ann Acad Med Singap 1989; 18:348-51. [PMID: 2679337] [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] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A rapid method of assay, using a monoclonal antibody linked to alkaline phosphatase, was used for the detection of the Pontiac subgroup of Legionella pneumophila serogroup 1. It was tested for its specificity against 53 strains of Legionella recently isolated from the environment in Singapore and Malaysia. The specificity and sensitivity of this method of assay was confirmed, though there is some concern that the specificity was too narrow, and there are reservations about the criteria suggested for interpreting the results.
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Affiliation(s)
- E W Lim
- Microbiology Department, National University of Singapore
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Meers PD, Goh KT, Lim EW. Legionella species, serogroups and subgroups found in the environment in Singapore. Ann Acad Med Singap 1989; 18:375-8. [PMID: 2802506] [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] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Over a period of seven months, 87 samples of water collected from 48 air-conditioning cooling-towers on 15 sites in Singapore yielded 19 strains of Legionella. Legionellas were found in 7 of the 15 sites. The strains isolated fell into 7 species, serogroups or subgroups of the genus Legionella. Only 11% of them belonged to the more pathogenic Pontiac subgroup of Legionella pneumophila serogroup 1.
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Affiliation(s)
- P D Meers
- Microbiology Department, National University of Singapore
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Tan RJ, Lim EW, Ishak B. Intestinal bacterial flora of the household lizard, Gecko gecko. Res Vet Sci 1978; 24:262-3. [PMID: 653125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A total of 114 isolates was recovered from the intestines of 43 househould lizards, Gecko gecko. Among the important ones were Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aeruginosa, Proteus mirabilis and Edwardsiella tarda.
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Abstract
Mycoplasmas were isolated from various sites and organs of a series of 319 clinically healthy cats. They include M. felis, M. gateae, M. Arginini, A. laidlawii, feline ureaplasmas, M. pulmonis, M. arthritidis, and M. gallisepticum. In addition, there were 10 strains of mycoplasmas which could not be identified with the specific antiserums by growth inhibition tests. Antibody against M. felis was demonstrated by haemagglutination-inhibition and complement-fixation tests in cats which were over 6 months of age. However, no such antibody against M. felis was detected in animals which were less than 6 months old. No antibody against A. laidlawii, M. gateae, M. arginini and feline ureaplasmas was demonstrated by the same serological methods. The significance of these mycoplasmas in cats is described.
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Stan RJ, Lim EW, Sakazaki R. Unusual cause of urinary tract infection by Pseudomonas stutzeri in Singapore. Jpn J Exp Med 1977; 47:311-3. [PMID: 926404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Tan RJ, Lim EW, Ishak B. Significance and pathogenic role of Mycoplasma arginini in cat diseases. Can J Comp Med 1977; 41:349-54. [PMID: 907911 PMCID: PMC1277602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Eighty-one strans of Mycoplasma arginini were isolated from swabs and tissues cultured from a series of 555 cats. The majority of these strains (84%) were recovered from the oropharyngeal regions. M. arginini was experimentally inoculated into young kittens. No clinical disease was produced. However, there was rapid colonization in the inoculated sites.
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Abstract
During the period 1971-4, Torulopsis glabrata formed 42% of yeasts isolated from 5677 clinical specimens from patients with cancers, diabetes mellitus, chronic renal failure, pregnacy or major surgical operations complicated by mycotic infections. The significance of T. glabrata in these patients is discussed.
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Abstract
Urinary tract infections result mostly from ascending infection by micro-organisms introduced by way of the urethra. Bacteria are the usual causative agents. Occasionally, yeasts notably Candida albicans, are involved. Females are more prone to acute infections than males because of shorter urethra and the higher risks of contamination in the females.
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