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Wedan RJ, Longenecker JZ, Nowinski SM. Mitochondrial fatty acid synthesis is an emergent central regulator of mammalian oxidative metabolism. Cell Metab 2024; 36:36-47. [PMID: 38128528 PMCID: PMC10843818 DOI: 10.1016/j.cmet.2023.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/27/2023] [Accepted: 11/30/2023] [Indexed: 12/23/2023]
Abstract
Contrary to their well-known functions in nutrient breakdown, mitochondria are also important biosynthetic hubs and express an evolutionarily conserved mitochondrial fatty acid synthesis (mtFAS) pathway. mtFAS builds lipoic acid and longer saturated fatty acids, but its exact products, their ultimate destination in cells, and the cellular significance of the pathway are all active research questions. Moreover, why mitochondria need mtFAS despite their well-defined ability to import fatty acids is still unclear. The identification of patients with inborn errors of metabolism in mtFAS genes has sparked fresh research interest in the pathway. New mammalian models have provided insights into how mtFAS coordinates many aspects of oxidative mitochondrial metabolism and raise questions about its role in diseases such as obesity, diabetes, and heart failure. In this review, we discuss the products of mtFAS, their function, and the consequences of mtFAS impairment across models and in metabolic disease.
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Affiliation(s)
- Riley J Wedan
- Department of Metabolism and Nutritional Programming, The Van Andel Institute, Grand Rapids, MI 49503, USA; College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA
| | - Jacob Z Longenecker
- Department of Metabolism and Nutritional Programming, The Van Andel Institute, Grand Rapids, MI 49503, USA
| | - Sara M Nowinski
- Department of Metabolism and Nutritional Programming, The Van Andel Institute, Grand Rapids, MI 49503, USA.
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2
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Suo Y, Chen A, La Clair JJ, Burkart MD. Substrate Sequestration and Chain Flipping in Human Mitochondrial Acyl Carrier Protein. Biochemistry 2023; 62:3548-3553. [PMID: 38039071 DOI: 10.1021/acs.biochem.3c00447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Outside of their involvement in energy production, mitochondria play a critical role for the cell through their access to a discrete pathway for fatty acid biosynthesis. Despite decades of study in bacterial fatty acid synthases (the putative evolutionary mitochondrial precursor), our understanding of human mitochondrial fatty acid biosynthesis remains incomplete. In particular, the role of the key carrier protein, human mitochondrial acyl carrier protein (mACP), which shuttles the substrate intermediates through the pathway, has not been well-studied in part due to challenges in protein expression and purification. Herein, we report a reliable method for recombinant Escherichia coli expression and purification of mACP. Fundamental characteristics, including substrate sequestration and chain-flipping activity, are demonstrated in mACP using solvatochromic response. This study provides an efficient approach toward understanding the fundamental protein-protein interactions of mACP and its partner proteins, ultimately leading to a molecular understanding of human mitochondrial diseases such as mitochondrial fatty acid oxidation deficiencies.
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Affiliation(s)
- Yixing Suo
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Aochiu Chen
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - James J La Clair
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Michael D Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
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3
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Dhembla C, Kumar A, Arya R, Kundu S, Sundd M. Mitochondrial Acyl Carrier Protein of Leishmania major Displays Features Distinct from the Canonical Type II ACP. Biochemistry 2023; 62:3347-3359. [PMID: 37967383 DOI: 10.1021/acs.biochem.3c00455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
Prokaryotes synthesize fatty acids using a type II synthesis pathway (FAS). In this process, the central player, i.e., the acyl carrier protein (ACP), sequesters the growing acyl chain in its internal hydrophobic cavity. As the acyl chain length increases, the cavity expands in size, which is reflected in the NMR chemical shift perturbations and crystal structures of the acyl-ACP intermediates. A few eukaryotic organelles, such as plastids and mitochondria, also harbor type II fatty acid synthesis machinery. Plastid FAS from spinach and Plasmodium falciparum has been characterized at the molecular level, but the mitochondrial pathway remains unexplored. Here, we report NMR studies of the mitochondrial acyl-acyl carrier protein intermediates of Leishmania major (acyl-LmACP). Our studies show that LmACP experiences remarkably small conformational changes upon acylation, with perturbations confined to helices II and III only. CastP determined that the cavity size of apo-LmACP (PDB entry 5ZWT) is less than that of Escherichia coli ACP (PDB 1T8K). Thus, the small chemical shift perturbations observed in the LmACP intermediates, coupled with CastP results, suggest an unusually small cavity when fully expanded. The faster rate of C8-LmACP chain hydrolysis compared to E. coli ACP (EcACP) also supports these convictions. Structure comparison of LmACP with other type II ACP disclosed unique differences in the helix I and loop I conformations, as well as several residues present there. Numerous hydrophobic residues in helix I and loop I (conserved in all mitochondrial ACPs) are substituted with hydrophilic residues in the bacterial/plastid type II ACP. For instance, Phe and leucine at positions 14 and 34 in LmACP are substituted with a hydrophilic residue and Ala in bacterial/plastid type II ACP. Mutation of Leu 34 to Ala (corresponding residue in EcACP) resulted in a complete loss of structure, underscoring its importance in maintaining the ACP fold. Thus, our NMR studies, combined with insights from the crystal structure, highlight several unique features of LmACP, distinct from the prokaryote and plastid type II ACP. Given the high sequence identity, the features might be conserved in all mitochondrial ACPs.
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Affiliation(s)
- Chetna Dhembla
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Ambrish Kumar
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
| | - Richa Arya
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Suman Kundu
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Monica Sundd
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
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4
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Álvarez-Córdoba M, Talaverón-Rey M, Povea-Cabello S, Cilleros-Holgado P, Gómez-Fernández D, Piñero-Pérez R, Reche-López D, Munuera-Cabeza M, Suárez-Carrillo A, Romero-González A, Romero-Domínguez JM, López-Cabrera A, Armengol JÁ, Sánchez-Alcázar JA. Patient-Derived Cellular Models for Polytarget Precision Medicine in Pantothenate Kinase-Associated Neurodegeneration. Pharmaceuticals (Basel) 2023; 16:1359. [PMID: 37895830 PMCID: PMC10609847 DOI: 10.3390/ph16101359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/21/2023] [Accepted: 09/21/2023] [Indexed: 10/29/2023] Open
Abstract
The term neurodegeneration with brain iron accumulation (NBIA) brings together a broad set of progressive and disabling neurological genetic disorders in which iron is deposited preferentially in certain areas of the brain. Among NBIA disorders, the most frequent subtype is pantothenate kinase-associated neurodegeneration (PKAN) caused by pathologic variants in the PANK2 gene codifying the enzyme pantothenate kinase 2 (PANK2). To date, there are no effective treatments to stop the progression of these diseases. This review discusses the utility of patient-derived cell models as a valuable tool for the identification of pharmacological or natural compounds for implementing polytarget precision medicine in PKAN. Recently, several studies have described that PKAN patient-derived fibroblasts present the main pathological features associated with the disease including intracellular iron overload. Interestingly, treatment of mutant cell cultures with various supplements such as pantothenate, pantethine, vitamin E, omega 3, α-lipoic acid L-carnitine or thiamine, improved all pathophysiological alterations in PKAN fibroblasts with residual expression of the PANK2 enzyme. The information provided by pharmacological screenings in patient-derived cellular models can help optimize therapeutic strategies in individual PKAN patients.
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Affiliation(s)
- Mónica Álvarez-Córdoba
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Marta Talaverón-Rey
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Suleva Povea-Cabello
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Paula Cilleros-Holgado
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - David Gómez-Fernández
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Rocío Piñero-Pérez
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Diana Reche-López
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Manuel Munuera-Cabeza
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Alejandra Suárez-Carrillo
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Ana Romero-González
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Jose Manuel Romero-Domínguez
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - Alejandra López-Cabrera
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
| | - José Ángel Armengol
- Department of Physiology, Anatomy and Cellular Biology, Pablo de Olavide University, 41013 Seville, Spain;
| | - José Antonio Sánchez-Alcázar
- Andalusian Centre for Developmental Biology (CABD-CSIC-Pablo de Olavide University), 41013 Seville, Spain; (M.Á.-C.); (M.T.-R.); (S.P.-C.); (P.C.-H.); (D.G.-F.); (R.P.-P.); (D.R.-L.); (M.M.-C.); (A.S.-C.); (A.R.-G.); (J.M.R.-D.); (A.L.-C.)
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5
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Khawaja A, Cipullo M, Krüger A, Rorbach J. Insights into mitoribosomal biogenesis from recent structural studies. Trends Biochem Sci 2023; 48:629-641. [PMID: 37169615 DOI: 10.1016/j.tibs.2023.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 05/13/2023]
Abstract
The mitochondrial ribosome (mitoribosome) is a multicomponent machine that has unique structural features. Biogenesis of the human mitoribosome includes correct maturation and folding of the mitochondria-encoded RNA components (12S and 16S mt-rRNAs, and mt-tRNAVal) and their assembly together with 82 nucleus-encoded mitoribosomal proteins. This complex process requires the coordinated action of multiple assembly factors. Recent advances in single-particle cryo-electron microscopy (cryo-EM) have provided detailed insights into the specific functions of several mitoribosome assembly factors and have defined their timing. In this review we summarize mitoribosomal small (mtSSU) and large subunit (mtLSU) biogenesis based on structural findings, and we discuss potential crosstalk between mtSSU and mtLSU assembly pathways as well as coordination between mitoribosome biogenesis and other processes involved in mitochondrial gene expression.
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Affiliation(s)
- Anas Khawaja
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65 Solna, Sweden; Max Planck Institute Biology of Ageing, Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Miriam Cipullo
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65 Solna, Sweden; Max Planck Institute Biology of Ageing, Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Annika Krüger
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65 Solna, Sweden; Max Planck Institute Biology of Ageing, Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Joanna Rorbach
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65 Solna, Sweden; Max Planck Institute Biology of Ageing, Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden.
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6
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Clifford MN, King LJ, Kerimi A, Pereira-Caro MG, Williamson G. Metabolism of phenolics in coffee and plant-based foods by canonical pathways: an assessment of the role of fatty acid β-oxidation to generate biologically-active and -inactive intermediates. Crit Rev Food Sci Nutr 2022; 64:3326-3383. [PMID: 36226718 DOI: 10.1080/10408398.2022.2131730] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
ω-Phenyl-alkenoic acids are abundant in coffee, fruits, and vegetables. Along with ω-phenyl-alkanoic acids, they are produced from numerous dietary (poly)phenols and aromatic amino acids in vivo. This review addresses how phenyl-ring substitution and flux modulates their gut microbiota and endogenous β-oxidation. 3',5'-Dihydroxy-derivatives (from alkyl-resorcinols, flavanols, proanthocyanidins), and 4'-hydroxy-phenolic acids (from tyrosine, p-coumaric acid, naringenin) are β-oxidation substrates yielding benzoic acids. In contrast, 3',4',5'-tri-substituted-derivatives, 3',4'-dihydroxy-derivatives and 3'-methoxy-4'-hydroxy-derivatives (from coffee, tea, cereals, many fruits and vegetables) are poor β-oxidation substrates with metabolism diverted via gut microbiota dehydroxylation, phenylvalerolactone formation and phase-2 conjugation, possibly a strategy to conserve limited pools of coenzyme A. 4'-Methoxy-derivatives (citrus fruits) or 3',4'-dimethoxy-derivatives (coffee) are susceptible to hepatic "reverse" hydrogenation suggesting incompatibility with enoyl-CoA-hydratase. Gut microbiota-produced 3'-hydroxy-4'-methoxy-derivatives (citrus fruits) and 3'-hydroxy-derivatives (numerous (poly)phenols) are excreted as the phenyl-hydracrylic acid β-oxidation intermediate suggesting incompatibility with hydroxy-acyl-CoA dehydrogenase, albeit with considerable inter-individual variation. Further investigation is required to explain inter-individual variation, factors determining the amino acid to which C6-C3 and C6-C1 metabolites are conjugated, the precise role(s) of l-carnitine, whether glycine might be limiting, and whether phenolic acid-modulation of β-oxidation explains how phenolic acids affect key metabolic conditions, such as fatty liver, carbohydrate metabolism and insulin resistance.
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Affiliation(s)
- Michael N Clifford
- School of Bioscience and Medicine, University of Surrey, Guildford, UK
- Department of Nutrition, Dietetics and Food, Monash University, Clayton, Australia
| | - Laurence J King
- School of Bioscience and Medicine, University of Surrey, Guildford, UK
| | - Asimina Kerimi
- Department of Nutrition, Dietetics and Food, Monash University, Clayton, Australia
| | - Maria Gema Pereira-Caro
- Department of Food Science and Health, Instituto Andaluz de Investigacion y Formacion Agraria Pesquera Alimentaria y de la Produccion Ecologica, Sevilla, Spain
| | - Gary Williamson
- Department of Nutrition, Dietetics and Food, Monash University, Clayton, Australia
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7
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Paiva P, Medina FE, Viegas M, Ferreira P, Neves RPP, Sousa JPM, Ramos MJ, Fernandes PA. Animal Fatty Acid Synthase: A Chemical Nanofactory. Chem Rev 2021; 121:9502-9553. [PMID: 34156235 DOI: 10.1021/acs.chemrev.1c00147] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fatty acids are crucial molecules for most living beings, very well spread and conserved across species. These molecules play a role in energy storage, cell membrane architecture, and cell signaling, the latter through their derivative metabolites. De novo synthesis of fatty acids is a complex chemical process that can be achieved either by a metabolic pathway built by a sequence of individual enzymes, such as in most bacteria, or by a single, large multi-enzyme, which incorporates all the chemical capabilities of the metabolic pathway, such as in animals and fungi, and in some bacteria. Here we focus on the multi-enzymes, specifically in the animal fatty acid synthase (FAS). We start by providing a historical overview of this vast field of research. We follow by describing the extraordinary architecture of animal FAS, a homodimeric multi-enzyme with seven different active sites per dimer, including a carrier protein that carries the intermediates from one active site to the next. We then delve into this multi-enzyme's detailed chemistry and critically discuss the current knowledge on the chemical mechanism of each of the steps necessary to synthesize a single fatty acid molecule with atomic detail. In line with this, we discuss the potential and achieved FAS applications in biotechnology, as biosynthetic machines, and compare them with their homologous polyketide synthases, which are also finding wide applications in the same field. Finally, we discuss some open questions on the architecture of FAS, such as their peculiar substrate-shuttling arm, and describe possible reasons for the emergence of large megasynthases during evolution, questions that have fascinated biochemists from long ago but are still far from answered and understood.
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Affiliation(s)
- Pedro Paiva
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Fabiola E Medina
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
| | - Matilde Viegas
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Pedro Ferreira
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Rui P P Neves
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - João P M Sousa
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Maria J Ramos
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Pedro A Fernandes
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
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8
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Li H, Yuan S, Minegishi Y, Suga A, Yoshitake K, Sheng X, Ye J, Smith S, Bunkoczi G, Yamamoto M, Iwata T. Novel mutations in malonyl-CoA-acyl carrier protein transacylase provoke autosomal recessive optic neuropathy. Hum Mol Genet 2021; 29:444-458. [PMID: 31915829 DOI: 10.1093/hmg/ddz311] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/28/2019] [Accepted: 12/16/2019] [Indexed: 12/15/2022] Open
Abstract
Inherited optic neuropathies are rare eye diseases of optic nerve dysfunction that present in various genetic forms. Previously, mutation in three genes encoding mitochondrial proteins has been implicated in autosomal recessive forms of optic atrophy that involve progressive degeneration of optic nerve and retinal ganglion cells (RGC). Using whole exome analysis, a novel double homozygous mutation p.L81R and pR212W in malonyl CoA-acyl carrier protein transacylase (MCAT), a mitochondrial protein involved in fatty acid biosynthesis, has now been identified as responsible for an autosomal recessive optic neuropathy from a Chinese consanguineous family. MCAT is expressed in RGC that are rich in mitochondria. The disease variants lead to structurally unstable MCAT protein with significantly reduced intracellular expression. RGC-specific knockdown of Mcat in mice, lead to an attenuated retinal neurofiber layer, that resembles the phenotype of optic neuropathy. These results indicated that MCAT plays an essential role in mitochondrial function and maintenance of RGC axons, while novel MCAT p.L81R and p.R212W mutations can lead to optic neuropathy.
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Affiliation(s)
- Huiping Li
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.,Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region, No. 936, Huang He East Road,Yinchuan, 750001, China
| | - Shiqin Yuan
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.,Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region, No. 936, Huang He East Road,Yinchuan, 750001, China
| | - Yuriko Minegishi
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
| | - Akiko Suga
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
| | - Kazutoshi Yoshitake
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
| | - Xunlun Sheng
- Ningxia Clinical Research Center of Blinding Eye Disease, Ningxia Eye Hospital, People Hospital of Ningxia Hui Autonomous Region, No. 936, Huang He East Road,Yinchuan, 750001, China
| | - Jianping Ye
- Pennington Biomedical Research Center, Louisiana State University Systems, 6400, Perkin Road, Baton Rouge, LA, 70808, USA
| | - Stuart Smith
- Children's Hospital Oakland Research Institute, 5700, Martin Luther King Jr. Way, Oakland, CA, 94609, USA
| | - Gabor Bunkoczi
- Astex Pharmaceuticals, 436, Cambridge Science Park, Cambridge, CB4 0QA, UK
| | - Megumi Yamamoto
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
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9
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Álvarez-Córdoba M, Talaverón-Rey M, Villalón-García I, Povea-Cabello S, Suárez-Rivero JM, Suárez-Carrillo A, Munuera-Cabeza M, Salas JJ, Sánchez-Alcázar JA. Down regulation of the expression of mitochondrial phosphopantetheinyl-proteins in pantothenate kinase-associated neurodegeneration: pathophysiological consequences and therapeutic perspectives. Orphanet J Rare Dis 2021; 16:201. [PMID: 33952316 PMCID: PMC8101147 DOI: 10.1186/s13023-021-01823-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 04/20/2021] [Indexed: 02/06/2023] Open
Abstract
Background Neurodegeneration with brain iron accumulation (NBIA) is a group of genetic neurological disorders frequently associated with iron accumulation in the basal nuclei of the brain characterized by progressive spasticity, dystonia, muscle rigidity, neuropsychiatric symptoms, and retinal degeneration or optic nerve atrophy. Pantothenate kinase-associated neurodegeneration (PKAN) is the most widespread NBIA disorder. It is caused by mutations in the gene of pantothenate kinase 2 (PANK2) which catalyzes the first reaction of coenzyme A (CoA) biosynthesis. Thus, altered PANK2 activity is expected to induce CoA deficiency as well as low levels of essential metabolic intermediates such as 4′-phosphopantetheine which is a necessary cofactor for critical proteins involved in cytosolic and mitochondrial pathways such as fatty acid biosynthesis, mitochondrial respiratory complex I assembly and lysine and tetrahydrofolate metabolism, among other metabolic processes. Methods In this manuscript, we examined the effect of PANK2 mutations on the expression levels of proteins with phosphopantetheine cofactors in fibroblast derived from PKAN patients. These proteins include cytosolic acyl carrier protein (ACP), which is integrated within the multifunctional polypeptide chain of the fatty acid synthase involved in cytosolic fatty acid biosynthesis type I (FASI); mitochondrial ACP (mtACP) associated with mitocondrial fatty acid biosynthesis type II (FASII); mitochondrial alpha-aminoadipic semialdehyde synthase (AASS); and 10-formyltetrahydrofolate dehydrogenases (cytosolic, ALD1L1, and mitochondrial, ALD1L2). Results In PKAN fibroblasts the expression levels of cytosolic FAS and ALD1L1 were not affected while the expression levels of mtACP, AASS and ALD1L2 were markedly reduced, suggesting that 4′-phosphopantetheinylation of mitochondrial but no cytosolic proteins were markedly affected in PKAN patients. Furthermore, the correction of PANK2 expression levels by treatment with pantothenate in selected mutations with residual enzyme content was able to correct the expression levels of mitochondrial phosphopantetheinyl-proteins and restore the affected pathways. The positive effects of pantothenate in particular mutations were also corroborated in induced neurons obtained by direct reprograming of mutant PANK2 fibroblasts. Conclusions Our results suggest that the expression levels of mitochondrial phosphopantetheinyl-proteins are severely reduced in PKAN cells and that in selected mutations pantothenate increases the expression levels of both PANK2 and mitochondrial phosphopantetheinyl-proteins associated with remarkable improvement of cell pathophysiology. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-021-01823-3.
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Affiliation(s)
- Mónica Álvarez-Córdoba
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain.,Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, 41013, Sevilla, Spain
| | - Marta Talaverón-Rey
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain.,Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, 41013, Sevilla, Spain
| | - Irene Villalón-García
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain.,Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, 41013, Sevilla, Spain
| | - Suleva Povea-Cabello
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain.,Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, 41013, Sevilla, Spain
| | - Juan M Suárez-Rivero
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain.,Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, 41013, Sevilla, Spain
| | - Alejandra Suárez-Carrillo
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain.,Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, 41013, Sevilla, Spain
| | - Manuel Munuera-Cabeza
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain.,Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, 41013, Sevilla, Spain
| | - Joaquín J Salas
- Departamento de Bioquímica Y Biología Molecular de Productos Vegetales, Instituto de La Grasa (CSIC), Sevilla, Spain
| | - José A Sánchez-Alcázar
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain. .,Centro de Investigación Biomédica en Red: Enfermedades Raras, Instituto de Salud Carlos III, 41013, Sevilla, Spain.
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10
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Palombo V, Alharthi A, Batistel F, Parys C, Guyader J, Trevisi E, D'Andrea M, Loor JJ. Unique adaptations in neonatal hepatic transcriptome, nutrient signaling, and one-carbon metabolism in response to feeding ethyl cellulose rumen-protected methionine during late-gestation in Holstein cows. BMC Genomics 2021; 22:280. [PMID: 33865335 PMCID: PMC8053294 DOI: 10.1186/s12864-021-07538-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/11/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Methionine (Met) supply during late-pregnancy enhances fetal development in utero and leads to greater rates of growth during the neonatal period. Due to its central role in coordinating nutrient and one-carbon metabolism along with immune responses of the newborn, the liver could be a key target of the programming effects induced by dietary methyl donors such as Met. To address this hypothesis, liver biopsies from 4-day old calves (n = 6/group) born to Holstein cows fed a control or the control plus ethyl-cellulose rumen-protected Met for the last 28 days prepartum were used for DNA methylation, transcriptome, metabolome, proteome, and one-carbon metabolism enzyme activities. RESULTS Although greater withers and hip height at birth in Met calves indicated better development in utero, there were no differences in plasma systemic physiological indicators. RNA-seq along with bioinformatics and transcription factor regulator analyses revealed broad alterations in 'Glucose metabolism', 'Lipid metabolism, 'Glutathione', and 'Immune System' metabolism due to enhanced maternal Met supply. Greater insulin sensitivity assessed via proteomics, and efficiency of transsulfuration pathway activity suggested beneficial effects on nutrient metabolism and metabolic-related stress. Maternal Met supply contributed to greater phosphatidylcholine synthesis in calf liver, with a role in very low density lipoprotein secretion as a mechanism to balance metabolic fates of fatty acids arising from the diet or adipose-depot lipolysis. Despite a lack of effect on hepatic amino acid (AA) transport, a reduction in metabolism of essential AA within the liver indicated an AA 'sparing effect' induced by maternal Met. CONCLUSIONS Despite greater global DNA methylation, maternal Met supply resulted in distinct alterations of hepatic transcriptome, proteome, and metabolome profiles after birth. Data underscored an effect on maintenance of calf hepatic Met homeostasis, glutathione, phosphatidylcholine and taurine synthesis along with greater efficiency of nutrient metabolism and immune responses. Transcription regulators such as FOXO1, PPARG, E2F1, and CREB1 appeared central in the coordination of effects induced by maternal Met. Overall, maternal Met supply induced better immunometabolic status of the newborn liver, conferring the calf a physiologic advantage during a period of metabolic stress and suboptimal immunocompetence.
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Affiliation(s)
- Valentino Palombo
- Dipartimento Agricoltura, Ambiente e Alimenti, Università degli Studi del Molise, via De Sanctis snc, 86100, Campobasso, Italy
- Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, 61801, USA
| | - Abdulrahman Alharthi
- Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, 61801, USA
- Department of Animal Production, College of Food and Agriculture Sciences, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Fernanda Batistel
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT, 84322, USA
| | - Claudia Parys
- Evonik Operations GmbH, Hanau-Wolfgang, 63457, Essen, Germany
| | - Jessie Guyader
- Evonik Operations GmbH, Hanau-Wolfgang, 63457, Essen, Germany
| | - Erminio Trevisi
- Department of Animal Sciences, Food and Nutrition (DIANA), Università Cattolica del Sacro Cuore, 29122, Piacenza, Italy
| | - Mariasilvia D'Andrea
- Dipartimento Agricoltura, Ambiente e Alimenti, Università degli Studi del Molise, via De Sanctis snc, 86100, Campobasso, Italy
| | - Juan J Loor
- Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, 61801, USA.
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11
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Gender dependent differences in lipid metabolism in individuals with type 2 diabetes mellitus. J Diabetes Metab Disord 2021; 19:967-977. [PMID: 33520816 DOI: 10.1007/s40200-020-00589-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 07/13/2020] [Indexed: 12/18/2022]
Abstract
Aim The present study investigates gender dependent effects of insulin resistance on lipid profile and adipocytokines in individuals with diabetes receiving oral antidiabetic drugs (OADs). The aim was also to reveal the changes in the expression of genes involved in lipid metabolism and inflammation. Methods Lipid profile, adipocytokine levels and homeostatic model assessment of insulin resistance (HOMA-IR) was assessed in 100 patients with diabetes (M = 43, F = 57) matched for age and gender with healthy individuals (M = 45, F = 55). The expression pattern of genes was analyzed by quantitative real time PCR. Results Males consuming metformin with other drugs exhibited a positive association between HOMA-IR and cholesterol, triglyceride and very low density lipoprotein (VLDL). Females consuming only metformin and metformin with other drugs, showed a positive association of HOMA-IR with cholesterol and a negative association with adiponectin. In males and females with diabetes, a comparable expression of peroxisome proliferator activated receptor γ (PPARγ) while higher expression of sterol regulatory element binding protein 1 (SREBP1) was observed. Expression of fatty acid synthase (FAS), long chain acyl CoA Synthetases (ACSL), malonyl-CoA-acyl carrier protein transacylase (MCAT) and nuclear factor kappa β (NFkβ) was higher in men with diabetes than healthy males. Expression of tumor necrosis factor α (TNF-α) was higher in males and females with diabetes than respective healthy genders. Conclusion Insulin resistance adversely affects lipid profile, adipocytokines in males with type 2 diabetes. Expression of genes involved in lipid metabolism and inflammation is found to be undesirably and differentially altered in both the genders.
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12
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Nowinski SM, Solmonson A, Rusin SF, Maschek JA, Bensard CL, Fogarty S, Jeong MY, Lettlova S, Berg JA, Morgan JT, Ouyang Y, Naylor BC, Paulo JA, Funai K, Cox JE, Gygi SP, Winge DR, DeBerardinis RJ, Rutter J. Mitochondrial fatty acid synthesis coordinates oxidative metabolism in mammalian mitochondria. eLife 2020; 9:58041. [PMID: 32804083 PMCID: PMC7470841 DOI: 10.7554/elife.58041] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 08/15/2020] [Indexed: 12/13/2022] Open
Abstract
Cells harbor two systems for fatty acid synthesis, one in the cytoplasm (catalyzed by fatty acid synthase, FASN) and one in the mitochondria (mtFAS). In contrast to FASN, mtFAS is poorly characterized, especially in higher eukaryotes, with the major product(s), metabolic roles, and cellular function(s) being essentially unknown. Here we show that hypomorphic mtFAS mutant mouse skeletal myoblast cell lines display a severe loss of electron transport chain (ETC) complexes and exhibit compensatory metabolic activities including reductive carboxylation. This effect on ETC complexes appears to be independent of protein lipoylation, the best characterized function of mtFAS, as mutants lacking lipoylation have an intact ETC. Finally, mtFAS impairment blocks the differentiation of skeletal myoblasts in vitro. Together, these data suggest that ETC activity in mammals is profoundly controlled by mtFAS function, thereby connecting anabolic fatty acid synthesis with the oxidation of carbon fuels.
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Affiliation(s)
| | - Ashley Solmonson
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Scott F Rusin
- Department of Cell Biology, Harvard University School of Medicine, Boston, United States
| | - J Alan Maschek
- Diabetes & Metabolism Research Center, Salt Lake City, United States.,Department of Nutrition and Integrative Physiology, Salt Lake City, United States.,Metabolomics, Proteomics and Mass Spectrometry Core Research Facilities University of Utah, Salt Lake City, United States
| | | | - Sarah Fogarty
- Department of Biochemistry, Salt Lake City, United States.,Howard Hughes Medical Institute, Salt Lake City, United States
| | - Mi-Young Jeong
- Department of Biochemistry, Salt Lake City, United States
| | | | - Jordan A Berg
- Department of Biochemistry, Salt Lake City, United States
| | - Jeffrey T Morgan
- Department of Biochemistry, Salt Lake City, United States.,Howard Hughes Medical Institute, Salt Lake City, United States
| | - Yeyun Ouyang
- Department of Biochemistry, Salt Lake City, United States
| | - Bradley C Naylor
- Metabolomics, Proteomics and Mass Spectrometry Core Research Facilities University of Utah, Salt Lake City, United States
| | - Joao A Paulo
- Department of Cell Biology, Harvard University School of Medicine, Boston, United States
| | - Katsuhiko Funai
- Diabetes & Metabolism Research Center, Salt Lake City, United States
| | - James E Cox
- Department of Biochemistry, Salt Lake City, United States.,Diabetes & Metabolism Research Center, Salt Lake City, United States.,Metabolomics, Proteomics and Mass Spectrometry Core Research Facilities University of Utah, Salt Lake City, United States
| | - Steven P Gygi
- Department of Cell Biology, Harvard University School of Medicine, Boston, United States
| | - Dennis R Winge
- Department of Biochemistry, Salt Lake City, United States.,Diabetes & Metabolism Research Center, Salt Lake City, United States.,Department of Internal Medicine, Salt Lake City, United States
| | - Ralph J DeBerardinis
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, Salt Lake City, United States
| | - Jared Rutter
- Department of Biochemistry, Salt Lake City, United States.,Diabetes & Metabolism Research Center, Salt Lake City, United States.,Howard Hughes Medical Institute, Salt Lake City, United States
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13
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Schwartz L, Peres S, Jolicoeur M, da Veiga Moreira J. Cancer and Alzheimer's disease: intracellular pH scales the metabolic disorders. Biogerontology 2020; 21:683-694. [PMID: 32617766 DOI: 10.1007/s10522-020-09888-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 06/23/2020] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) and cancer have much in common than previously recognized. These pathologies share common risk factors (inflammation and aging), with similar epidemiological and biochemical features such as impaired mitochondria. Metabolic reprogramming occurs during aging and inflammation. We assume that inflammation is directly responsible of the Warburg effect in cancer cells, with a decreased oxidative phosphorylation and a compensatory highthroughput glycolysis (HTG). Similarly, the Warburg effect in cancer is thought to support an alkaline intracellular pH (pHi), a key component of unrelenting cell growth. In the brain, inflammation results in increased secretion of lactate by astrocytes. The increased uptake of lactic acid by neurons results in the inverse Warburg effect, such as seen in AD. The neuronal activity is dampened by a fall of pHi. Pronounced cytosol acidification results in decreased mitochondrial energy yield as well as apoptotic cell death. The link between AD and cancer is reinforced by the fact that treatment aiming at restoring the mitochondrial activity have been experimentally shown to be effective in both diseases. Low carb diet, lipoic acid, and/or methylene blue could then appear promising in both sets of these clinically diverse diseases.
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Affiliation(s)
| | - Sabine Peres
- LRI, Université Paris-Sud, CNRS, Université Paris-Saclay, 91405, Orsay, France.,MaIAGE, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Mario Jolicoeur
- Research Laboratory in Applied Metabolic Engineering, Department of Chemical, Engineering, Ecole Polytechnique de Montréal, Montréal, QC, Canada
| | - Jorgelindo da Veiga Moreira
- Research Laboratory in Applied Metabolic Engineering, Department of Chemical, Engineering, Ecole Polytechnique de Montréal, Montréal, QC, Canada.
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14
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Uncarboxylated osteocalcin ameliorates hepatic glucose and lipid metabolism in KKAy mice via activating insulin signaling pathway. Acta Pharmacol Sin 2020; 41:383-393. [PMID: 31659239 PMCID: PMC7470804 DOI: 10.1038/s41401-019-0311-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 09/19/2019] [Indexed: 12/21/2022] Open
Abstract
Osteocalcin, expressed in osteoblasts of the bone marrow, undergoes post-translational carboxylation and deposits in mineralized bone matrix. A portion of osteocalcin remains uncarboxylated (uncarboxylated osteocalcin, GluOC) that is released into blood where it functions as a hormone to regulate insulin secretion and insulin sensitivity. As insulin resistance is closely associated with metabolic syndrome, this study is aimed to elucidate how GluOC regulates glucose and lipid metabolism in KKAy mice, an animal model displaying obese, hyperglycemia, hyperinsulinemia, insulin resistance, and hepatic steatosis. GluOC (3, 30 ng/g per day, ig) was orally administered to female KKAy mice for 4 weeks. Whole-body insulin sensitivity, glucose metabolism, hepatic steatosis, dyslipidemia were examined using routine laboratory assays. We found that GluOC administration significantly enhanced insulin sensitivity in KKAy mice by activating hepatic IRβ/PI3K/Akt pathway and elevated the whole-body insulin sensitivity with decreased FPI and HOMA-IR index. Furthermore, GluOC administration alleviated hyperglycemia through suppressing gluconeogenesis and promoting glycogen synthesis in KKAy mice and in cultured hepatocytes in vitro. Moreover, GluOC administration dose-dependently ameliorated dyslipidemia and attenuated hepatic steatosis in KKAy mice by inhibiting hepatic de novo lipogenesis and promoting fatty-acid β-oxidation. These results demonstrate that GluOC effectively enhances hepatic insulin sensitivity, improves hyperglycemia and ameliorates hepatic steatosis in KKAy mice, suggesting that GluOC could be a promising drug candidate for treating metabolic syndrome.
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15
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Abstract
Biology students today are taught that mitochondria are 'the powerhouse of the cell'. This gross over-simplification of their cellular role has arguably led to a paucity of knowledge concerning the many other tasks carried out by this multifunctional organelle. Mitochondrial fatty acid synthesis (mtFAS) is one such under-appreciated pathway that is crucial for mitochondrial function, although even mitochondrial experts are often surprised to learn of its existence. For many years, the only function of mtFAS was thought to be the production of lipoic acid, an important co-factor for several mitochondrial enzymes. However, recent advances have revealed a far wider role for mtFAS in mitochondrial physiology. The discovery of human patients with mutations in mtFAS enzymes has brought renewed interest in understanding the full significance of this novel mode of mitochondrial metabolic regulation. We now appreciate that mtFAS is a nutrient-sensitive pathway that provides an elegant mechanism whereby acetyl-CoA regulates its own consumption via coordination of lipoic acid synthesis and tricarboxylic acid (TCA) cycle activity, iron-sulfur (FeS) cluster biogenesis, assembly of oxidative phosphorylation complexes, and mitochondrial translation. In this minireview, we describe and build upon the important discoveries that led to our current understanding of this elegant mechanism of coordination of nutrient status and metabolism.
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16
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Sun W, Luo Y, Wang DH, Kothapalli KSD, Brenna JT. Branched chain fatty acid composition of yak milk and manure during full-lactation and half-lactation. Prostaglandins Leukot Essent Fatty Acids 2019; 150:16-20. [PMID: 31521006 DOI: 10.1016/j.plefa.2019.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/15/2019] [Accepted: 09/04/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Branched chain fatty acids (BCFA) are bioactive food compounds and are well known to be essential components of human, cow and caprine milk. In Qinghai-Tibet plateau, yaks are domesticated in large numbers and their milk in addition to meat are commercially important to millions of Tibetans and Chinese. OBJECTIVE We tested the hypotheses that concentrations of BCFA in yak milk and manure differ between lactation periods and evaluated gene expression levels of certain genes involved in the biosynthesis and elongation of fatty acids. DESIGN Fresh milk and manure were collected from each yak and their fatty acid compositions compared with emphasis on BCFA. PARTICIPANTS/SETTING Yak milk and manure samples from the full lactation (October, 2015) and half lactation periods (March, 2016) were collected and BCFA levels were analyzed in detail by GC-FID and structures verified by GC-EI-MS/MS. Gene expression studies were carried out by semi-quantitative real time PCR method. STATISTICAL ANALYSES PERFORMED The difference between full lactation and half lactation was tested using student's t-test. Linear regression model was modelled in Excel and its significance was tested by ANOVA. Statistical significance was determined by performing student's t-test for gene expression studies. RESULTS BCFA ranged from 3-6% of total fatty acids in yak milk samples. The half-lactation yak milk contained higher levels of BCFA (5.29 ± 0.53) than the full-lactation milk (4.00 ± 0.46). The total BCFA in yak manure was found to be 14.67 ± 1.21, high in anteiso-15:0 and anteiso-17:0. ELOVL1 enzyme involved in the elongation of saturated C18 to C26 acyl-CoA substrates and MCAT enzyme involved in the transfer of a malonyl group to the mitochondrial acyl carrier protein are significantly upregulated in full-lactation milk. CONCLUSIONS BCFA in yak manure especially anteiso BCFA are positively correlated with yak milk from the same animal, indicating that these BCFA come from dietary sources. Yak milk delivers 777 mg BCFA compared to 158 mg per cup of whole U.S. dairy milk. QTP herders known to consume up to 2 kg of yak yogurt take in an estimated 3,500-5,000 mg BCFA per day. We conclude that BCFA intake for yak milk consumers is among the highest known in the world, higher when drawn from half lactating yaks.
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Affiliation(s)
- Wancheng Sun
- Animal Science Department, College of Agriculture and Animal Husbandry, Qinghai University, Xining 810016, China; Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Yihao Luo
- Animal Science Department, College of Agriculture and Animal Husbandry, Qinghai University, Xining 810016, China
| | - Dong Hao Wang
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Kumar S D Kothapalli
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA; Dell Pediatric Research Institute and Deptartment of Pediatrics, Dell Medical School, The University of Texas at Austin, 1400 Barbara Jordan Blvd, Austin, TX 78723, USA
| | - J Thomas Brenna
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA; Dell Pediatric Research Institute and Deptartment of Pediatrics, Dell Medical School, The University of Texas at Austin, 1400 Barbara Jordan Blvd, Austin, TX 78723, USA.
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17
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Masud AJ, Kastaniotis AJ, Rahman MT, Autio KJ, Hiltunen JK. Mitochondrial acyl carrier protein (ACP) at the interface of metabolic state sensing and mitochondrial function. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:118540. [PMID: 31473256 DOI: 10.1016/j.bbamcr.2019.118540] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/23/2019] [Accepted: 08/27/2019] [Indexed: 12/20/2022]
Abstract
Acyl carrier protein (ACP) is a principal partner in the cytosolic and mitochondrial fatty acid synthesis (FAS) pathways. The active form holo-ACP serves as FAS platform, using its 4'-phosphopantetheine group to present covalently attached FAS intermediates to the enzymes responsible for the acyl chain elongation process. Mitochondrial unacylated holo-ACP is a component of mammalian mitoribosomes, and acylated ACP species participate as interaction partners in several ACP-LYRM (leucine-tyrosine-arginine motif)-protein heterodimers that act either as assembly factors or subunits of the electron transport chain and Fe-S cluster assembly complexes. Moreover, octanoyl-ACP provides the C8 backbone for endogenous lipoic acid synthesis. Accumulating evidence suggests that mtFAS-generated acyl-ACPs act as signaling molecules in an intramitochondrial metabolic state sensing circuit, coordinating mitochondrial acetyl-CoA levels with mitochondrial respiration, Fe-S cluster biogenesis and protein lipoylation.
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Affiliation(s)
- Ali J Masud
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | | | - M Tanvir Rahman
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Kaija J Autio
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - J Kalervo Hiltunen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.
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18
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Heil CS, Wehrheim SS, Paithankar KS, Grininger M. Fatty Acid Biosynthesis: Chain‐Length Regulation and Control. Chembiochem 2019; 20:2298-2321. [DOI: 10.1002/cbic.201800809] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/20/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Christina S. Heil
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
| | - S. Sophia Wehrheim
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
| | - Karthik S. Paithankar
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
| | - Martin Grininger
- Institute of Organic Chemistry and Chemical BiologyBuchmann Institute for Molecular Life ScienceGoethe University Frankfurt Max-von-Laue-Strasse 15 60438 Frankfurt am Main Germany
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19
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Jung SH, Kim RJ, Kim KJ, Lee DH, Suh MC. Plastidial and Mitochondrial Malonyl CoA-ACP Malonyltransferase is Essential for Cell Division and Its Overexpression Increases Storage Oil Content. PLANT & CELL PHYSIOLOGY 2019; 60:1239-1249. [PMID: 30796840 DOI: 10.1093/pcp/pcz032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 02/08/2019] [Indexed: 06/09/2023]
Abstract
Malonyl-acyl carrier protein (ACP) is a key building block for the synthesis of fatty acids, which are important components of cell membranes, storage oils and lipid-signaling molecules. Malonyl CoA-ACP malonyltransferase (MCAMT) catalyzes the production of malonyl-ACP and CoA from malonyl-CoA and ACP. Here, we report that MCAMT plays a critical role in cell division and has the potential to increase the storage oil content in Arabidopsis. The quantitative real-time PCR and MCAMT promoter:GUS analyses showed that MCAMT is predominantly expressed in shoot and root apical meristems, leaf hydathodes and developing embryos. The fluorescent signals of MCAMT:eYFP were observed in both chloroplasts and mitochondria of tobacco leaf protoplasts. In particular, the N-terminal region (amino acid residues 1-30) of MCAMT was required for mitochondrial targeting. The Arabidopsis mcamt-1 and -2 mutants exhibited an embryo-lethal phenotype because of the arrest of embryo development at the globular stage. The transgenic Arabidopsis expressing antisense MCAMT RNA showed growth retardation caused by the defects in cell division. The overexpression of MCAMT driven by the promoter of the senescence-associated 1 (SEN1) gene, which is predominantly expressed in developing seeds, increased the seed yield and storage oil content of Arabidopsis. Taken together, the plastidial and mitochondrial MCAMT is essential for Arabidopsis cell division and is a novel genetic resource useful for enhancing storage oil content in oilseed crops.
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Affiliation(s)
- Seh Hui Jung
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Ryeo Jin Kim
- Department of Life Science, Sogang University, Seoul, Republic of Korea
| | - Kook Jin Kim
- Genomine Inc. Venture Bldg 306, Pohang TechnoPark, 394 Jigok-ro, Nam-gu, Pohang, Republic of Korea
| | - Dong Hee Lee
- Genomine Inc. Venture Bldg 306, Pohang TechnoPark, 394 Jigok-ro, Nam-gu, Pohang, Republic of Korea
| | - Mi Chung Suh
- Department of Life Science, Sogang University, Seoul, Republic of Korea
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20
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Zhang Y, Ye J, Fan J. Regulation of malonyl-CoA-acyl carrier protein transacylase network in umbilical cord blood affected by intrauterine hyperglycemia. Oncotarget 2017; 8:75254-75263. [PMID: 29088862 PMCID: PMC5650417 DOI: 10.18632/oncotarget.20766] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 07/30/2017] [Indexed: 12/22/2022] Open
Abstract
Background Gestational diabetes mellitus (GDM) has been shown to be associated with high risk of diabetes in offspring. However, the mechanisms involved in the insulin resistance in offspring are still unclear. Mitochondrial dysfunction is related with insulin resistance. In mitochondria, malonyl-CoA-acyl carrier protein transacylase (MCAT) is the key enzyme of mitochondrial fatty acid synthesis and is estimated to contribute to insulin resistance. In this study, we aimed to examine the role of MCAT and its network in the umbilical cord blood in GDM-induced offspring insulin resistance. Methods We isolated lymphocytes from umbilical cord vein blood in 6 GDM patients and 6 controls and examined the differences of RNA by RNA sequencing. qRT-PCR and western blot were used to measure mRNA and protein changes. Bisulfite genomic sequencing PCR was applied to detect DNA methylation. Results We found more than 400 genes were differentially regulated in the lymphocytes of umbilical cord blood from GDM patients and these genes were mainly enriched in immune system and endocrine system, which relate to mitochondrial dysfunction and insulin resistance. MCAT closely related with PTPN1 (Protein Tyrosine Phosphatase, Non-Receptor Type1) and STAT5A (Signal Transducer And Activator of Transcription 5A), which were all increased in umbilical cord blood from GDM patients. Increase in MCAT may be due to decreased MCAT DNA methylation. Conclusion MCAT and its network with PTPN1, STAT5A are regulated in umbilical cord blood affected by maternal intrauterine hyperglycemia.
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Affiliation(s)
- Yong Zhang
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China.,Institute of Embryo-Fetal Original Adult Disease Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Jianping Ye
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA 70808, USA
| | - Jianxia Fan
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China
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21
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Shen LF, Chen YJ, Liu KM, Haddad ANS, Song IW, Roan HY, Chen LY, Yen JJY, Chen YJ, Wu JY, Chen YT. Role of S-Palmitoylation by ZDHHC13 in Mitochondrial function and Metabolism in Liver. Sci Rep 2017; 7:2182. [PMID: 28526873 PMCID: PMC5438363 DOI: 10.1038/s41598-017-02159-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 04/12/2017] [Indexed: 11/17/2022] Open
Abstract
Palmitoyltransferase (PAT) catalyses protein S-palmitoylation which adds 16-carbon palmitate to specific cysteines and contributes to various biological functions. We previously reported that in mice, deficiency of Zdhhc13, a member of the PAT family, causes severe phenotypes including amyloidosis, alopecia, and osteoporosis. Here, we show that Zdhhc13 deficiency results in abnormal liver function, lipid abnormalities, and hypermetabolism. To elucidate the molecular mechanisms underlying these disease phenotypes, we applied a site-specific quantitative approach integrating an alkylating resin-assisted capture and mass spectrometry-based label-free strategy for studying the liver S-palmitoylome. We identified 2,190 S-palmitoylated peptides corresponding to 883 S-palmitoylated proteins. After normalization using the membrane proteome with TMT10-plex labelling, 400 (31%) of S-palmitoylation sites on 254 proteins were down-regulated in Zdhhc13-deficient mice, representing potential ZDHHC13 substrates. Among these, lipid metabolism and mitochondrial dysfunction proteins were overrepresented. MCAT and CTNND1 were confirmed to be specific ZDHHC13 substrates. Furthermore, we found impaired mitochondrial function in hepatocytes of Zdhhc13-deficient mice and Zdhhc13-knockdown Hep1–6 cells. These results indicate that ZDHHC13 is an important regulator of mitochondrial activity. Collectively, our study allows for a systematic view of S-palmitoylation for identification of ZDHHC13 substrates and demonstrates the role of ZDHHC13 in mitochondrial function and metabolism in liver.
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Affiliation(s)
- Li-Fen Shen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yi-Ju Chen
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
| | - Kai-Ming Liu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Amir N Saleem Haddad
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - I-Wen Song
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hsiao-Yuh Roan
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Li-Ying Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Jeffrey J Y Yen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yu-Ju Chen
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
| | - Jer-Yuarn Wu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yuan-Tsong Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan. .,Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America.
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22
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Sun J, Ye X, Xie M, Ye J. Induction of triglyceride accumulation and mitochondrial maintenance in muscle cells by lactate. Sci Rep 2016; 6:33732. [PMID: 27645401 PMCID: PMC5028732 DOI: 10.1038/srep33732] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 09/01/2016] [Indexed: 11/02/2022] Open
Abstract
Muscle exercise induces intramuscular triglyceride (TG) accumulation and promotes mitochondrial maintenance in myotubes. However, the mechanism underlying exercise effects remains unknown. In this study, lactic acid was tested as a signaling molecule in C2C12 myotubes to understand the mechanism. Intracellular TG storage was induced in the cells by sodium lactate. The lactate activity was observed with an inhibition of the cAMP-PKA pathway as indicated by a reduction in the phosphorylation status of CREB (pCREB). Induction of pCREB signal by forskolin was blocked by pretreatment of cells with lactate. The impact of lactate on mitochondrial function was examined with a focus on the activities of two enzymes, MCAT (malonylCoA:ACP transferase) and PDH (pyruvate dehydrogenase). The enzyme activities were induced in the cells by lactate. Expression of the lactate receptor (GPR81) and lactate transporters (MCT1/4) were induced as well by lactate. The lactate activities were observed at concentrations between 4-64 mM, and were not dependent on the increase in intracellular pyruvate. Pyruvate treatment did not generate the same effects in the cells. Those results suggest that lactate may induce intramuscular TG storage and mitochondrial maintenance in myotubes through inhibition of the cAMP pathway by activation of GPR81 in a positive feedback manner.
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Affiliation(s)
- Jingquan Sun
- Sport Science College of Beijing Sport University, Beijing, China.,Antioxidant and Gene Regulation Laboratory, Pennington Biomedical Research Center, Louisiana State University, Louisiana, USA
| | - Xin Ye
- Antioxidant and Gene Regulation Laboratory, Pennington Biomedical Research Center, Louisiana State University, Louisiana, USA
| | - Minhao Xie
- China Institute of Sports Medicine, Beijing, China
| | - Jianping Ye
- Antioxidant and Gene Regulation Laboratory, Pennington Biomedical Research Center, Louisiana State University, Louisiana, USA
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23
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Kastaniotis AJ, Autio KJ, Kerätär JM, Monteuuis G, Mäkelä AM, Nair RR, Pietikäinen LP, Shvetsova A, Chen Z, Hiltunen JK. Mitochondrial fatty acid synthesis, fatty acids and mitochondrial physiology. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:39-48. [PMID: 27553474 DOI: 10.1016/j.bbalip.2016.08.011] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 07/20/2016] [Accepted: 08/17/2016] [Indexed: 02/07/2023]
Abstract
Mitochondria and fatty acids are tightly connected to a multiplicity of cellular processes that go far beyond mitochondrial fatty acid metabolism. In line with this view, there is hardly any common metabolic disorder that is not associated with disturbed mitochondrial lipid handling. Among other aspects of mitochondrial lipid metabolism, apparently all eukaryotes are capable of carrying out de novo fatty acid synthesis (FAS) in this cellular compartment in an acyl carrier protein (ACP)-dependent manner. The dual localization of FAS in eukaryotic cells raises the questions why eukaryotes have maintained the FAS in mitochondria in addition to the "classic" cytoplasmic FAS and what the products are that cannot be substituted by delivery of fatty acids of extramitochondrial origin. The current evidence indicates that mitochondrial FAS is essential for cellular respiration and mitochondrial biogenesis. Although both β-oxidation and FAS utilize thioester chemistry, CoA acts as acyl-group carrier in the breakdown pathway whereas ACP assumes this role in the synthetic direction. This arrangement metabolically separates these two pathways running towards opposite directions and prevents futile cycling. A role of this pathway in mitochondrial metabolic sensing has recently been proposed. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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Affiliation(s)
- Alexander J Kastaniotis
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland.
| | - Kaija J Autio
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Juha M Kerätär
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Geoffray Monteuuis
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Anne M Mäkelä
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Remya R Nair
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Laura P Pietikäinen
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Antonina Shvetsova
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Zhijun Chen
- State Key Laboratory of Supramolecular Structure and Materials and Institute of Theoretical Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China
| | - J Kalervo Hiltunen
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland; State Key Laboratory of Supramolecular Structure and Materials and Institute of Theoretical Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
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24
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Harijan RK, Mazet M, Kiema TR, Bouyssou G, Alexson SEH, Bergmann U, Moreau P, Michels PAM, Bringaud F, Wierenga RK. The SCP2-thiolase-like protein (SLP) of Trypanosoma brucei is an enzyme involved in lipid metabolism. Proteins 2016; 84:1075-96. [PMID: 27093562 DOI: 10.1002/prot.25054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 04/03/2016] [Accepted: 04/08/2016] [Indexed: 11/06/2022]
Abstract
Bioinformatics studies have shown that the genomes of trypanosomatid species each encode one SCP2-thiolase-like protein (SLP), which is characterized by having the YDCF thiolase sequence fingerprint of the Cβ2-Cα2 loop. SLPs are only encoded by the genomes of these parasitic protists and not by those of mammals, including human. Deletion of the Trypanosoma brucei SLP gene (TbSLP) increases the doubling time of procyclic T. brucei and causes a 5-fold reduction of de novo sterol biosynthesis from glucose- and acetate-derived acetyl-CoA. Fluorescence analyses of EGFP-tagged TbSLP expressed in the parasite located the TbSLP in the mitochondrion. The crystal structure of TbSLP (refined at 1.75 Å resolution) confirms that TbSLP has the canonical dimeric thiolase fold. In addition, the structures of the TbSLP-acetoacetyl-CoA (1.90 Å) and TbSLP-malonyl-CoA (2.30 Å) complexes reveal that the two oxyanion holes of the thiolase active site are preserved. TbSLP binds malonyl-CoA tightly (Kd 90 µM), acetoacetyl-CoA moderately (Kd 0.9 mM) and acetyl-CoA and CoA very weakly. TbSLP possesses low malonyl-CoA decarboxylase activity. Altogether, the data show that TbSLP is a mitochondrial enzyme involved in lipid metabolism. Proteins 2016; 84:1075-1096. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Rajesh K Harijan
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, FIN-90014, Finland.,Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, 10461, USA
| | - Muriel Mazet
- Centre De Résonance Magnétique Des Systèmes Biologiques (RMSB), UMR5536, Université De Bordeaux, CNRS, 146 Rue Léo Saignat, Bordeaux, 33076, France.,Laboratoire De Microbiologie Fondamentale Et Pathogénicité (MFP), UMR5234, Université De Bordeaux, CNRS, 146 Rue Léo Saignat, Bordeaux, 33076, France
| | - Tiila R Kiema
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, FIN-90014, Finland
| | - Guillaume Bouyssou
- Laboratoire De Biogenèse Membranaire, UMR-5200, Université De Bordeaux, CNRS, Bâtiment A3 - 1er Étage, INRA Bordeaux Aquitaine BP81, 71 Avenue Edouard Bourlaux, Villenave D'Ornon Cedex, 33883, France
| | - Stefan E H Alexson
- Karolinska Institutet, Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, Stockholm, SE 141 86, Sweden
| | - Ulrich Bergmann
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, FIN-90014, Finland
| | - Patrick Moreau
- Laboratoire De Biogenèse Membranaire, UMR-5200, Université De Bordeaux, CNRS, Bâtiment A3 - 1er Étage, INRA Bordeaux Aquitaine BP81, 71 Avenue Edouard Bourlaux, Villenave D'Ornon Cedex, 33883, France
| | - Paul A M Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, the King's Buildings, University of Edinburgh, Charlotte Auerbach Road, Edinburgh, EH9 3FL, United Kingdom
| | - Frédéric Bringaud
- Centre De Résonance Magnétique Des Systèmes Biologiques (RMSB), UMR5536, Université De Bordeaux, CNRS, 146 Rue Léo Saignat, Bordeaux, 33076, France.,Laboratoire De Microbiologie Fondamentale Et Pathogénicité (MFP), UMR5234, Université De Bordeaux, CNRS, 146 Rue Léo Saignat, Bordeaux, 33076, France
| | - Rik K Wierenga
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, FIN-90014, Finland
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25
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Ghadge A, Harsulkar A, Karandikar M, Pandit V, Kuvalekar A. Comparative anti-inflammatory and lipid-normalizing effects of metformin and omega-3 fatty acids through modulation of transcription factors in diabetic rats. GENES AND NUTRITION 2016; 11:10. [PMID: 27551311 PMCID: PMC4968436 DOI: 10.1186/s12263-016-0518-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 12/11/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Emerging evidence suggests beneficial effects of omega-3 fatty acids on diabetic complications. The present study compared the progressive effects of metformin and flax/fish oil on lipid metabolism, inflammatory markers, and liver and renal function test markers in streptozotocin-nicotinamide-induced diabetic rats. METHODS Streptozotocin-induced diabetic rats were randomized into control and four diabetic groups: streptozotocin (STZ), metformin (200 mg/kg body weight (b.w)/day (D)), flax and fish oil (500 mg/kg b.w/D). RESULTS Metformin and flax and fish oil exhibited increased expression of transcription factor peroxisome proliferator-activated receptor γ while the treatment downregulated sterol regulatory element-binding protein 1 and nuclear factor kβ as compared to those of the STZ group. Apart from modulation of transcription factor expression, the expression of fatty acid synthase, long chain acyl CoA synthase, and malonyl-CoA-acyl carrier protein transacylase was lowered by flax/fish oil treatment. Serum cholesterol, triglycerides, and VLDL were also significantly reduced in the treatment groups as compared to those in the STZ group. Although pathological abnormalities were seen in the liver and kidneys of rats on metformin, no significant changes in liver/renal function markers were observed at day 15 and day 30 of the treatment groups. Flax/fish oil had protective effects toward pathological abnormalities in the liver and kidney. Flax/fish oil improved lipid profile and alkaline phosphatase at day 30 as compared to that at day 15. CONCLUSIONS The present study demonstrates potential beneficial effects of metformin and flax/fish oil intervention in improving serum lipid profile by regulating the expression of transcription factors and genes involved in lipid metabolism in diabetic rats. In addition, these interventions also lowered the expression of atherogenic cytokines. The protective effects of flax/fish oil are worth investigating in human subjects on metformin monotherapy.
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Affiliation(s)
- Abhijit Ghadge
- Nutrigenomics and Functional Foods Laboratory, Interactive Research School for Health Affairs (IRSHA), Bharati Vidyapeeth Deemed University, Pune-Satara Road, Pune, Maharashtra 411043 India
| | - Abhay Harsulkar
- Nutrigenomics and Functional Foods Laboratory, Interactive Research School for Health Affairs (IRSHA), Bharati Vidyapeeth Deemed University, Pune-Satara Road, Pune, Maharashtra 411043 India
| | - Manjiri Karandikar
- Department of Pathology, Bharati Vidyapeeth Medical College, Bharati Vidyapeeth Deemed University, Pune-Satara Road, Pune, Maharashtra 411043 India
| | - Vijaya Pandit
- Department of Pharmacology, Bharati Vidyapeeth Medical College, Bharati Vidyapeeth Deemed University, Pune-Satara Road, Pune, Maharashtra 411043 India
| | - Aniket Kuvalekar
- Nutrigenomics and Functional Foods Laboratory, Interactive Research School for Health Affairs (IRSHA), Bharati Vidyapeeth Deemed University, Pune-Satara Road, Pune, Maharashtra 411043 India
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26
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Clay HB, Parl AK, Mitchell SL, Singh L, Bell LN, Murdock DG. Altering the Mitochondrial Fatty Acid Synthesis (mtFASII) Pathway Modulates Cellular Metabolic States and Bioactive Lipid Profiles as Revealed by Metabolomic Profiling. PLoS One 2016; 11:e0151171. [PMID: 26963735 PMCID: PMC4786287 DOI: 10.1371/journal.pone.0151171] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 02/24/2016] [Indexed: 01/10/2023] Open
Abstract
Despite the presence of a cytosolic fatty acid synthesis pathway, mitochondria have retained their own means of creating fatty acids via the mitochondrial fatty acid synthesis (mtFASII) pathway. The reason for its conservation has not yet been elucidated. Therefore, to better understand the role of mtFASII in the cell, we used thin layer chromatography to characterize the contribution of the mtFASII pathway to the fatty acid composition of selected mitochondrial lipids. Next, we performed metabolomic analysis on HeLa cells in which the mtFASII pathway was either hypofunctional (through knockdown of mitochondrial acyl carrier protein, ACP) or hyperfunctional (through overexpression of mitochondrial enoyl-CoA reductase, MECR). Our results indicate that the mtFASII pathway contributes little to the fatty acid composition of mitochondrial lipid species examined. Additionally, loss of mtFASII function results in changes in biochemical pathways suggesting alterations in glucose utilization and redox state. Interestingly, levels of bioactive lipids, including lysophospholipids and sphingolipids, directly correlate with mtFASII function, indicating that mtFASII may be involved in the regulation of bioactive lipid levels. Regulation of bioactive lipid levels by mtFASII implicates the pathway as a mediator of intracellular signaling.
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Affiliation(s)
- Hayley B. Clay
- Center for Human Genetics Research, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
- Neuroscience Graduate Program, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Angelika K. Parl
- Center for Human Genetics Research, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Sabrina L. Mitchell
- Center for Human Genetics Research, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Larry Singh
- Center for Mitochondrial and Epigenomic Medicine, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Lauren N. Bell
- Metabolon, Incorporated, Durham, North Carolina, United States of America
| | - Deborah G. Murdock
- Center for Human Genetics Research, Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail:
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27
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Beld J, Lee DJ, Burkart MD. Fatty acid biosynthesis revisited: structure elucidation and metabolic engineering. MOLECULAR BIOSYSTEMS 2015; 11:38-59. [PMID: 25360565 PMCID: PMC4276719 DOI: 10.1039/c4mb00443d] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Fatty acids are primary metabolites synthesized by complex, elegant, and essential biosynthetic machinery. Fatty acid synthases resemble an iterative assembly line, with an acyl carrier protein conveying the growing fatty acid to necessary enzymatic domains for modification. Each catalytic domain is a unique enzyme spanning a wide range of folds and structures. Although they harbor the same enzymatic activities, two different types of fatty acid synthase architectures are observed in nature. During recent years, strained petroleum supplies have driven interest in engineering organisms to either produce more fatty acids or specific high value products. Such efforts require a fundamental understanding of the enzymatic activities and regulation of fatty acid synthases. Despite more than one hundred years of research, we continue to learn new lessons about fatty acid synthases' many intricate structural and regulatory elements. In this review, we summarize each enzymatic domain and discuss efforts to engineer fatty acid synthases, providing some clues to important challenges and opportunities in the field.
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Affiliation(s)
- Joris Beld
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA.
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28
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Mayr JA, Feichtinger RG, Tort F, Ribes A, Sperl W. Lipoic acid biosynthesis defects. J Inherit Metab Dis 2014; 37:553-63. [PMID: 24777537 DOI: 10.1007/s10545-014-9705-8] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 03/11/2014] [Accepted: 03/12/2014] [Indexed: 01/10/2023]
Abstract
Lipoate is a covalently bound cofactor essential for five redox reactions in humans: in four 2-oxoacid dehydrogenases and the glycine cleavage system (GCS). Two enzymes are from the energy metabolism, α-ketoglutarate dehydrogenase and pyruvate dehydrogenase; and three are from the amino acid metabolism, branched-chain ketoacid dehydrogenase, 2-oxoadipate dehydrogenase, and the GCS. All these enzymes consist of multiple subunits and share a similar architecture. Lipoate synthesis in mitochondria involves mitochondrial fatty acid synthesis up to octanoyl-acyl-carrier protein; and three lipoate-specific steps, including octanoic acid transfer to glycine cleavage H protein by lipoyl(octanoyl) transferase 2 (putative) (LIPT2), lipoate synthesis by lipoic acid synthetase (LIAS), and lipoate transfer by lipoyltransferase 1 (LIPT1), which is necessary to lipoylate the E2 subunits of the 2-oxoacid dehydrogenases. The reduced form dihydrolipoate is reactivated by dihydrolipoyl dehydrogenase (DLD). Mutations in LIAS have been identified that result in a variant form of nonketotic hyperglycinemia with early-onset convulsions combined with a defect in mitochondrial energy metabolism with encephalopathy and cardiomyopathy. LIPT1 deficiency spares the GCS, and resulted in a combined 2-oxoacid dehydrogenase deficiency and early death in one patient and in a less severely affected individual with a Leigh-like phenotype. As LIAS is an iron-sulphur-cluster-dependent enzyme, a number of recently identified defects in mitochondrial iron-sulphur cluster synthesis, including NFU1, BOLA3, IBA57, GLRX5 presented with deficiency of LIAS and a LIAS-like phenotype. As in DLD deficiency, a broader clinical spectrum can be anticipated for lipoate synthesis defects depending on which of the affected enzymes is most rate limiting.
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Affiliation(s)
- Johannes A Mayr
- Department of Paediatrics, Paracelsus Medical University Salzburg, Salzburg, 5020, Austria,
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29
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Shin M, Bryant JD, Momb J, Appling DR. Mitochondrial MTHFD2L is a dual redox cofactor-specific methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase expressed in both adult and embryonic tissues. J Biol Chem 2014; 289:15507-17. [PMID: 24733394 DOI: 10.1074/jbc.m114.555573] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian mitochondria are able to produce formate from one-carbon donors such as serine, glycine, and sarcosine. This pathway relies on the mitochondrial pool of tetrahydrofolate (THF) and several folate-interconverting enzymes in the mitochondrial matrix. We recently identified MTHFD2L as the enzyme that catalyzes the oxidation of 5,10-methylenetetrahydrofolate (CH2-THF) in adult mammalian mitochondria. We show here that the MTHFD2L enzyme is bifunctional, possessing both CH2-THF dehydrogenase and 5,10-methenyl-THF cyclohydrolase activities. The dehydrogenase activity can use either NAD(+) or NADP(+) but requires both phosphate and Mg(2+) when using NAD(+). The NADP(+)-dependent dehydrogenase activity is inhibited by inorganic phosphate. MTHFD2L uses the mono- and polyglutamylated forms of CH2-THF with similar catalytic efficiencies. Expression of the MTHFD2L transcript is low in early mouse embryos but begins to increase at embryonic day 10.5 and remains elevated through birth. In adults, MTHFD2L is expressed in all tissues examined, with the highest levels observed in brain and lung.
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Affiliation(s)
- Minhye Shin
- From the Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Joshua D Bryant
- From the Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Jessica Momb
- From the Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Dean R Appling
- From the Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
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Kerner J, Minkler PE, Lesnefsky EJ, Hoppel CL. Fatty acid chain elongation in palmitate-perfused working rat heart: mitochondrial acetyl-CoA is the source of two-carbon units for chain elongation. J Biol Chem 2014; 289:10223-34. [PMID: 24558043 DOI: 10.1074/jbc.m113.524314] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rat hearts were perfused with [1,2,3,4-(13)C4]palmitic acid (M+4), and the isotopic patterns of myocardial acylcarnitines and acyl-CoAs were analyzed using ultra-HPLC-MS/MS. The 91.2% (13)C enrichment in palmitoylcarnitine shows that little endogenous (M+0) palmitate contributed to its formation. The presence of M+2 myristoylcarnitine (95.7%) and M+2 acetylcarnitine (19.4%) is evidence for β-oxidation of perfused M+4 palmitic acid. Identical enrichment data were obtained in the respective acyl-CoAs. The relative (13)C enrichment in M+4 (84.7%, 69.9%) and M+6 (16.2%, 17.8%) stearoyl- and arachidylcarnitine, respectively, clearly shows that the perfused palmitate is chain-elongated. The observed enrichment of (13)C in acetylcarnitine (19%), M+6 stearoylcarnitine (16.2%), and M+6 arachidylcarnitine (17.8%) suggests that the majority of two-carbon units for chain elongation are derived from β-oxidation of [1,2,3,4-(13)C4]palmitic acid. These data are explained by conversion of the M+2 acetyl-CoA to M+2 malonyl-CoA, which serves as the acceptor for M+4 palmitoyl-CoA in chain elongation. Indeed, the (13)C enrichment in mitochondrial acetyl-CoA (18.9%) and malonyl-CoA (19.9%) are identical. No (13)C enrichment was found in acylcarnitine species with carbon chain lengths between 4 and 12, arguing against the simple reversal of fatty acid β-oxidation. Furthermore, isolated, intact rat heart mitochondria 1) synthesize malonyl-CoA with simultaneous inhibition of carnitine palmitoyltransferase 1b and 2) catalyze the palmitoyl-CoA-dependent incorporation of (14)C from [2-(14)C]malonyl-CoA into lipid-soluble products. In conclusion, rat heart has the capability to chain-elongate fatty acids using mitochondria-derived two-carbon chain extenders. The data suggest that the chain elongation process is localized on the outer surface of the mitochondrial outer membrane.
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Wu X, Qin L, Fako V, Zhang JT. Molecular mechanisms of fatty acid synthase (FASN)-mediated resistance to anti-cancer treatments. Adv Biol Regul 2013; 54:214-21. [PMID: 24080588 DOI: 10.1016/j.jbior.2013.09.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 09/03/2013] [Indexed: 01/23/2023]
Abstract
Human FASN is the key enzyme required for de novo synthesis of fatty acids. Up-regulated FASN expression has been reported in various human cancers and was thought to contribute to poor prognosis and recurrence of these cancers. Studies using model cell lines have indicated the role of FASN in both intrinsic and acquired drug and radiation resistance. Recent studies suggest that FASN may play an important role in regulating gene expression such as pro-apoptotic proteins and cellular processes such as DNA repair pathways, which in turn contribute to resistance to drug and radiation-induced apoptosis. In this review, we will highlight our recent progress in understanding the mechanism of FASN-induced resistance.
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Affiliation(s)
- Xi Wu
- Department of Pharmacology and Toxicology and IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Li Qin
- Department of Pharmacology and Toxicology and IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Valerie Fako
- Department of Pharmacology and Toxicology and IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Jian-Ting Zhang
- Department of Pharmacology and Toxicology and IU Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Smith S, Witkowski A, Moghul A, Yoshinaga Y, Nefedov M, de Jong P, Feng D, Fong L, Tu Y, Hu Y, Young SG, Pham T, Cheung C, Katzman SM, Brand MD, Quinlan CL, Fens M, Kuypers F, Misquitta S, Griffey SM, Tran S, Gharib A, Knudsen J, Hannibal-Bach HK, Wang G, Larkin S, Thweatt J, Pasta S. Compromised mitochondrial fatty acid synthesis in transgenic mice results in defective protein lipoylation and energy disequilibrium. PLoS One 2012; 7:e47196. [PMID: 23077570 PMCID: PMC3471957 DOI: 10.1371/journal.pone.0047196] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 09/10/2012] [Indexed: 12/19/2022] Open
Abstract
A mouse model with compromised mitochondrial fatty acid synthesis has been engineered in order to assess the role of this pathway in mitochondrial function and overall health. Reduction in the expression of mitochondrial malonyl CoA-acyl carrier protein transacylase, a key enzyme in the pathway encoded by the nuclear Mcat gene, was achieved to varying extents in all examined tissues employing tamoxifen-inducible Cre-lox technology. Although affected mice consumed more food than control animals, they failed to gain weight, were less physically active, suffered from loss of white adipose tissue, reduced muscle strength, kyphosis, alopecia, hypothermia and shortened lifespan. The Mcat-deficient phenotype is attributed primarily to reduced synthesis, in several tissues, of the octanoyl precursors required for the posttranslational lipoylation of pyruvate and α-ketoglutarate dehydrogenase complexes, resulting in diminished capacity of the citric acid cycle and disruption of energy metabolism. The presence of an alternative lipoylation pathway that utilizes exogenous free lipoate appears restricted to liver and alone is insufficient for preservation of normal energy metabolism. Thus, de novo synthesis of precursors for the protein lipoylation pathway plays a vital role in maintenance of mitochondrial function and overall vigor.
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Affiliation(s)
- Stuart Smith
- Children's Hospital Oakland Research Institute, Oakland, California, USA.
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Witkowski A, Thweatt J, Smith S. Mammalian ACSF3 protein is a malonyl-CoA synthetase that supplies the chain extender units for mitochondrial fatty acid synthesis. J Biol Chem 2011; 286:33729-36. [PMID: 21846720 PMCID: PMC3190830 DOI: 10.1074/jbc.m111.291591] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Indexed: 11/06/2022] Open
Abstract
The objective of this study was to identify a source of intramitochondrial malonyl-CoA that could be used for de novo fatty acid synthesis in mammalian mitochondria. Because mammalian mitochondria lack an acetyl-CoA carboxylase capable of generating malonyl-CoA inside mitochondria, the possibility that malonate could act as a precursor was investigated. Although malonyl-CoA synthetases have not been identified previously in animals, interrogation of animal protein sequence databases identified candidates that exhibited sequence similarity to known prokaryotic forms. The human candidate protein ACSF3, which has a predicted N-terminal mitochondrial targeting sequence, was cloned, expressed, and characterized as a 65-kDa acyl-CoA synthetase with extremely high specificity for malonate and methylmalonate. An arginine residue implicated in malonate binding by prokaryotic malonyl-CoA synthetases was found to be positionally conserved in animal ACSF3 enzymes and essential for activity. Subcellular fractionation experiments with HEK293T cells confirmed that human ACSF3 is located exclusively in mitochondria, and RNA interference experiments verified that this enzyme is responsible for most, if not all, of the malonyl-CoA synthetase activity in the mitochondria of these cells. In conclusion, unlike fungi, which have an intramitochondrial acetyl-CoA carboxylase, animals require an alternative source of mitochondrial malonyl-CoA; the mitochondrial ACSF3 enzyme is capable of filling this role by utilizing free malonic acid as substrate.
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Affiliation(s)
- Andrzej Witkowski
- From the Children's Hospital Oakland Research Institute, Oakland, California 94609
| | - Jennifer Thweatt
- From the Children's Hospital Oakland Research Institute, Oakland, California 94609
| | - Stuart Smith
- From the Children's Hospital Oakland Research Institute, Oakland, California 94609
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Suozzi A, Malatesta M, Zancanaro C. Subcellular distribution of key enzymes of lipid metabolism during the euthermia-hibernation-arousal cycle. J Anat 2010; 214:956-62. [PMID: 19538638 DOI: 10.1111/j.1469-7580.2009.01086.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mammalian hibernation is a natural, fully reversible hypometabolic state characterized by a drastic reduction of body temperature and metabolic activity, which ensures survival to many species under adverse environmental conditions. During hibernation, many hibernators rely for energy supply almost exclusively on lipid reserves; the shift from carbohydrate to lipid metabolism implies profound rearrangement of the anabolic and catabolic pathways of energetic substrates. However, the structural counterpart of such adaptation is not known. In this study we investigated, by using immunoelectron microscopy, the fine intracellular distribution of two key enzymes involved in lipid metabolism, namely, the fatty acid synthase (FAS) and the long-chain fatty acyl-CoA synthetase (ACSL), in hepatocytes of euthermic, hibernating and arousing hazel dormice. Our results show that the two enzymes are differentially distributed in cellular compartments (cytoplasm, mitochondria and cell nuclei) of hepatocytes during euthermia. Quantitative redistribution of both enzymes among cellular compartments takes place during hibernation and arousal, in accordance with the physiological changes. Interestingly, this redistribution follows different seasonal patterns in cytoplasm, mitochondria and nuclei. In conclusion, our data represent the first quantitative morphological evidence of lipid enzyme distribution in a true hibernator throughout the year cycle, thus providing a structural framework to biochemical changes associated with the hypometabolism of hibernation.
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Affiliation(s)
- Anna Suozzi
- Dipartimento di Scienze Morfologico-Biomediche, University of Verona, Italy
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Hiltunen JK, Chen Z, Haapalainen AM, Wierenga RK, Kastaniotis AJ. Mitochondrial fatty acid synthesis – An adopted set of enzymes making a pathway of major importance for the cellular metabolism. Prog Lipid Res 2010; 49:27-45. [DOI: 10.1016/j.plipres.2009.08.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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37
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Gurvitz A. A C. elegans model for mitochondrial fatty acid synthase II: the longevity-associated gene W09H1.5/mecr-1 encodes a 2-trans-enoyl-thioester reductase. PLoS One 2009; 4:e7791. [PMID: 19924289 PMCID: PMC2774161 DOI: 10.1371/journal.pone.0007791] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 10/19/2009] [Indexed: 11/19/2022] Open
Abstract
Our recognition of the mitochondria as being important sites of fatty acid biosynthesis is continuously unfolding, especially in light of new data becoming available on compromised fatty acid synthase type 2 (FASII) in mammals. For example, perturbed regulation of murine 17β-HSD8 encoding a component of the mitochondrial FASII enzyme 3-oxoacyl-thioester reductase is implicated in polycystic kidney disease. In addition, over-expression in mice of the Mecr gene coding for 2-trans-enoyl-thioester reductase, also of mitochondrial FASII, leads to impaired heart function. However, mouse knockouts for mitochondrial FASII have hitherto not been reported and, hence, there is a need to develop alternate metazoan models such as nematodes or fruit flies. Here, the identification of Caenorhabditis elegans W09H1.5/MECR-1 as a 2-trans-enoyl-thioester reductase of mitochondrial FASII is reported. To identify MECR-1, Saccharomyces cerevisiae etr1Δ mutant cells were employed that are devoid of mitochondrial 2-trans-enoyl-thioester reductase Etr1p. These yeast mutants fail to synthesize sufficient levels of lipoic acid or form cytochrome complexes, and cannot respire or grow on non-fermentable carbon sources. A mutant yeast strain ectopically expressing nematode mecr-1 was shown to contain reductase activity and resemble the self-complemented mutant strain for these phenotype characteristics. Since MECR-1 was not intentionally targeted for compartmentalization using a yeast mitochondrial leader sequence, this inferred that the protein represented a physiologically functional mitochondrial 2-trans-enoyl-thioester reductase. In accordance with published findings, RNAi-mediated knockdown of mecr-1 in C. elegans resulted in life span extension, presumably due to mitochondrial dysfunction. Moreover, old mecr-1(RNAi) worms had better internal organ appearance and were more mobile than control worms, indicating a reduced physiological age. This is the first report on RNAi work dedicated specifically to curtailing mitochondrial FASII in metazoans. The availability of affected survivors will help to position C. elegans as an excellent model for future pursuits in the emerging field of mitochondrial FASII research.
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Affiliation(s)
- Aner Gurvitz
- Section of Physiology of Lipid Metabolism, Institute of Physiology, Center for Physiology, Pathophysiology and Immunology, Medical University of Vienna, Vienna, Austria.
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Bunkoczi G, Misquitta S, Wu X, Lee WH, Rojkova A, Kochan G, Kavanagh KL, Oppermann U, Smith S. Structural basis for different specificities of acyltransferases associated with the human cytosolic and mitochondrial fatty acid synthases. ACTA ACUST UNITED AC 2009; 16:667-75. [PMID: 19549604 DOI: 10.1016/j.chembiol.2009.04.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Revised: 03/26/2009] [Accepted: 04/14/2009] [Indexed: 12/28/2022]
Abstract
Animals employ two systems for the de novo biosynthesis of fatty acids: a megasynthase complex in the cytosol (type I) that produces mainly palmitate, and an ensemble of freestanding enzymes in the mitochondria (type II) that produces mainly octanoyl moieties. The acyltransferases responsible for initiation of fatty acid biosynthesis in the two compartments are distinguished by their different substrate specificities: the type I enzyme transfers both the acetyl primer and the malonyl chain extender, whereas the type II enzyme is responsible for translocation of only the malonyl substrate. Crystal structures for the type I and II enzymes, supported by in silico substrate docking studies and mutagenesis experiments that alter their respective specificities, reveal that, although the two enzymes adopt a similar overall fold, subtle differences at their catalytic centers account for their different specificities.
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Affiliation(s)
- Gabor Bunkoczi
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7LD, UK
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Chen Z, Kastaniotis AJ, Miinalainen IJ, Rajaram V, Wierenga RK, Hiltunen JK. 17beta-hydroxysteroid dehydrogenase type 8 and carbonyl reductase type 4 assemble as a ketoacyl reductase of human mitochondrial FAS. FASEB J 2009; 23:3682-91. [PMID: 19571038 DOI: 10.1096/fj.09-133587] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mitochondrial fatty acid synthesis (FAS) generates the octanoyl-group that is required for the synthesis of lipoic acid and is linked to mitochondrial RNA metabolism. All of the human enzymes involved in mitochondrial FAS have been characterized except for beta-ketoacyl thioester reductase (HsKAR), which catalyzes the second step in the pathway. We report here the unexpected finding that a heterotetramer composed of human 17beta-hydroxysteroid dehydrogenase type 8 (Hs17beta-HSD8) and human carbonyl reductase type 4 (HsCBR4) forms the long-sought HsKAR. Both proteins share sequence similarities to the yeast 3-oxoacyl-(acyl carrier protein) reductase (Oar1p) and the bacterial FabG, although HsKAR is NADH dependent, whereas FabG and Oar1p are NADPH dependent. Hs17beta-HSD8 and HsCBR4 show a strong genetic interaction in vivo in yeast, where, only if they are expressed together, they rescue the respiratory deficiency and restore the lipoic acid content of oar1Delta cells. Moreover, these two proteins display a stable physical interaction and form an active heterotetramer. Both Hs17beta-HSD8 and HsCBR4 are targeted to mitochondria in vivo in cultured HeLa cells. Notably, 17beta-HSD8 was previously classified as a steroid-metabolizing enzyme, but our data suggest that 17beta-HSD8 is primarily involved in mitochondrial FAS.
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Affiliation(s)
- Zhijun Chen
- Biocenter Oulu, and Department of Biochemistry, P. O. Box 3000, FI-90014 University of Oulu, Finland
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Zhao H, Martin BM, Bisoffi M, Dunaway-Mariano D. The Akt C-terminal modulator protein is an acyl-CoA thioesterase of the Hotdog-Fold family. Biochemistry 2009; 48:5507-9. [PMID: 19453107 PMCID: PMC2803014 DOI: 10.1021/bi900710w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Herein, we report on an in vitro kinetic activity analysis that demonstrates that the protein known as the Akt C-terminal modulator protein is a broad-range, high-activity acyl-CoA thioesterase. In vitro tests of possible activity regulation by product inhibition or by Akt1 binding gave negative results. Truncation mutants confined the thioesterase activity to the C-terminal domain, consistent with our threading model. The N-terminal domain of unknown fold and function was found to contribute to solubility.
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Affiliation(s)
- Hong Zhao
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque. New Mexico 87131
| | - Brian M. Martin
- Molecular Structure Unit, Laboratory of Neurotoxicology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892–1262
| | - Marco Bisoffi
- Molecular Structure Unit, Laboratory of Neurotoxicology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892–1262
| | - Debra Dunaway-Mariano
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque. New Mexico 87131
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Chen Z, Leskinen H, Liimatta E, Sormunen RT, Miinalainen IJ, Hassinen IE, Hiltunen JK. Myocardial overexpression of Mecr, a gene of mitochondrial FAS II leads to cardiac dysfunction in mouse. PLoS One 2009; 4:e5589. [PMID: 19440339 PMCID: PMC2680037 DOI: 10.1371/journal.pone.0005589] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 04/22/2009] [Indexed: 11/18/2022] Open
Abstract
It has been recently recognized that mammalian mitochondria contain most, if not all, of the components of fatty acid synthesis type II (FAS II). Among the components identified is 2-enoyl thioester reductase/mitochondrial enoyl-CoA reductase (Etr1/Mecr), which catalyzes the NADPH-dependent reduction of trans-2-enoyl thioesters, generating saturated acyl-groups. Although the FAS type II pathway is highly conserved, its physiological role in fatty acid synthesis, which apparently occurs simultaneously with breakdown of fatty acids in the same subcellular compartment in mammals, has remained an enigma. To study the in vivo function of the mitochondrial FAS in mammals, with special reference to Mecr, we generated mice overexpressing Mecr under control of the mouse metallothionein-1 promoter. These Mecr transgenic mice developed cardiac abnormalities as demonstrated by echocardiography in vivo, heart perfusion ex vivo, and electron microscopy in situ. Moreover, the Mecr transgenic mice showed decreased performance in endurance exercise testing. Our results showed a ventricular dilatation behind impaired heart function upon Mecr overexpression, concurrent with appearance of dysmorphic mitochondria. Furthermore, the data suggested that inappropriate expression of genes of FAS II can result in the development of hereditary cardiomyopathy.
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Affiliation(s)
- Zhijun Chen
- Biocenter Oulu and Department of Biochemistry, University of Oulu, Oulu, Finland
| | - Hanna Leskinen
- Biocenter Oulu and Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland
| | - Erkki Liimatta
- Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
| | - Raija T. Sormunen
- Biocenter Oulu and Department of Pathology, University of Oulu, Oulu, Finland
| | - Ilkka J. Miinalainen
- Biocenter Oulu and Department of Biochemistry, University of Oulu, Oulu, Finland
| | - Ilmo E. Hassinen
- Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
| | - J. Kalervo Hiltunen
- Biocenter Oulu and Department of Biochemistry, University of Oulu, Oulu, Finland
- * E-mail:
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Fiermonte G, Paradies E, Todisco S, Marobbio CMT, Palmieri F. A novel member of solute carrier family 25 (SLC25A42) is a transporter of coenzyme A and adenosine 3',5'-diphosphate in human mitochondria. J Biol Chem 2009; 284:18152-9. [PMID: 19429682 DOI: 10.1074/jbc.m109.014118] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial carriers are a family of proteins that transport metabolites, nucleotides, and cofactors across the inner mitochondrial membrane thereby connecting cytosolic and matrix functions. The essential cofactor coenzyme A (CoA) is synthesized outside the mitochondrial matrix and therefore must be transported into mitochondria where it is required for a number of fundamental processes. In this work we have functionally identified and characterized SLC25A42, a novel human member of the mitochondrial carrier family. The SLC25A42 gene (Haitina, T., Lindblom, J., Renström, T., and Fredriksson, R., 2006, Genomics 88, 779-790) was overexpressed in Escherichia coli, purified, and reconstituted into phospholipid vesicles. Its transport properties, kinetic parameters, and targeting to mitochondria demonstrate that SLC25A42 protein is a mitochondrial transporter for CoA and adenosine 3',5'-diphosphate. SLC25A42 catalyzed only a counter-exchange transport, exhibited a high transport affinity for CoA, dephospho-CoA, ADP, and adenosine 3',5'-diphosphate, was saturable and inhibited by bongkrekic acid and other inhibitors of mitochondrial carriers to various degrees. The main physiological role of SLC25A42 is to import CoA into mitochondria in exchange for intramitochondrial (deoxy)adenine nucleotides and adenosine 3',5'-diphosphate. This is the first time that a mitochondrial carrier for CoA and adenosine 3',5'-diphosphate has been characterized biochemically.
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Affiliation(s)
- Giuseppe Fiermonte
- Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari, Italy
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Cao J, Xu H, Zhao H, Gong W, Dunaway-Mariano D. The mechanisms of human hotdog-fold thioesterase 2 (hTHEM2) substrate recognition and catalysis illuminated by a structure and function based analysis. Biochemistry 2009; 48:1293-304. [PMID: 19170545 PMCID: PMC2929599 DOI: 10.1021/bi801879z] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The focus of this paper is the hotdog-fold thioesterase THEM2 from human (hTHEM2; Swiss-Prot entry Q9NPJ3 ). In an earlier communication (Cheng, Z., Song, F., Shan, X., Wei, Z., Wang, Y., Dunaway-Mariano, D., and Gong, W. (2006) Crystal structure of human thioesterase superfamily member 2, Biochem. Biophys. Res. Commun. 349, 172-177) we reported the apo crystal structure of hTHEM2. Herein, we report the results of an extensive hTHEM2 substrate screen, the structure determination of hTHEM2 complexed with the inert substrate analogue undecan-2-one-CoA (in which OC-CH(2)-S substitutes for OC-S) and the kinetic analysis of active site mutants. The work described in this paper represents the first reported structure-function based analysis of a human hotdog-fold thioesterase. The catalytic mechanism proposed involves the Asp65/Ser83 assisted attack of a water molecule at the Gly57/Asn50 polarized thioester CO and the Asn50 assisted departure of the thiolate leaving group. Thioesterase activity was observed with acyl-CoAs but not with the human acyl-ACP or with an acyl-Cys peptide. The medium-to-long-chain fatty acyl-CoAs displayed the smallest K(m) values. The substrate specificity profile was analyzed within the context of the liganded enzyme to define the structural determinants of substrate recognition. Based on the results of this structure-function analysis we hypothesize that the physiological role of hTHEM2 involves catalysis of the hydrolysis of cytosolic medium-to-long-chain acyl-CoA thioesters.
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Affiliation(s)
- Jian Cao
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131
| | - Hang Xu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China
| | - Hong Zhao
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131
| | - Weimin Gong
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China,Address correspondence to: For biochemical studies: Debra Dunaway-Mariano, Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, Tel: 505-277-3776, , Fax: +1 505-277-6202; For X-ray structure determination: Weimin Gong, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R., China, Tel: 8610-64888465, , Fax: +86 10 64888513
| | - Debra Dunaway-Mariano
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131,Address correspondence to: For biochemical studies: Debra Dunaway-Mariano, Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, Tel: 505-277-3776, , Fax: +1 505-277-6202; For X-ray structure determination: Weimin Gong, National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R., China, Tel: 8610-64888465, , Fax: +86 10 64888513
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Feng D, Witkowski A, Smith S. Down-regulation of mitochondrial acyl carrier protein in mammalian cells compromises protein lipoylation and respiratory complex I and results in cell death. J Biol Chem 2009; 284:11436-45. [PMID: 19221180 DOI: 10.1074/jbc.m806991200] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The objective of this study was to evaluate the physiological importance of the mitochondrial fatty acid synthesis pathway in mammalian cells using the RNA interference strategy. Transfection of HEK293T cells with small interfering RNAs targeting the acyl carrier protein (ACP) component reduced ACP mRNA and protein levels by >85% within 24 h. The earliest phenotypic changes observed were a marked decrease in the proportion of post-translationally lipoylated mitochondrial proteins recognized by anti-lipoate antibodies and a reduction in their catalytic activity, and a slowing of the cell growth rate. Later effects observed included a reduction in the specific activity of respiratory complex I, lowered mitochondrial membrane potential, the development of cytoplasmic membrane blebs containing high levels of reactive oxygen species and ultimately, cell death. Supplementation of the culture medium with lipoic acid offered some protection against oxidative damage but did not reverse the protein lipoylation defect. These observations are consistent with a dual role for ACP in mammalian mitochondrial function. First, as a key component of the mitochondrial fatty acid biosynthetic pathway, ACP plays an essential role in providing the octanoyl-ACP precursor required for the protein lipoylation pathway. Second, as one of the subunits of complex I, ACP is required for the efficient functioning of the electron transport chain and maintenance of normal mitochondrial membrane potential.
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Affiliation(s)
- Dejiang Feng
- Children's Hospital Oakland Research Institute, Oakland, California 94609, USA
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Castle JC, Hara Y, Raymond CK, Garrett-Engele P, Ohwaki K, Kan Z, Kusunoki J, Johnson JM. ACC2 is expressed at high levels in human white adipose and has an isoform with a novel N-terminus [corrected]. PLoS One 2009; 4:e4369. [PMID: 19190759 PMCID: PMC2629817 DOI: 10.1371/journal.pone.0004369] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Accepted: 12/12/2008] [Indexed: 11/18/2022] Open
Abstract
Acetyl-CoA carboxylases ACC1 and ACC2 catalyze the carboxylation of acetyl-CoA to malonyl-CoA, regulating fatty-acid synthesis and oxidation, and are potential targets for treatment of metabolic syndrome. Expression of ACC1 in rodent lipogenic tissues and ACC2 in rodent oxidative tissues, coupled with the predicted localization of ACC2 to the mitochondrial membrane, have suggested separate functional roles for ACC1 in lipogenesis and ACC2 in fatty acid oxidation. We find, however, that human adipose tissue, unlike rodent adipose, expresses more ACC2 mRNA relative to the oxidative tissues muscle and heart. Human adipose, along with human liver, expresses more ACC2 than ACC1. Using RT-PCR, real-time PCR, and immunoprecipitation we report a novel isoform of ACC2 (ACC2.v2) that is expressed at significant levels in human adipose. The protein generated by this isoform has enzymatic activity, is endogenously expressed in adipose, and lacks the N-terminal sequence. Both ACC2 isoforms are capable of de novo lipogenesis, suggesting that ACC2, in addition to ACC1, may play a role in lipogenesis. The results demonstrate a significant difference in ACC expression between human and rodents, which may introduce difficulties for the use of rodent models for development of ACC inhibitors.
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Affiliation(s)
- John C. Castle
- Rosetta Inpharmatics LLC, Seattle, Washington, United States of America
- * E-mail: (JCC); (JMJ)
| | - Yoshikazu Hara
- Metabolic Disorder Research, Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd., Tsukuba, Ibaraki, Japan
| | | | | | - Kenji Ohwaki
- Metabolic Disorder Research, Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd., Tsukuba, Ibaraki, Japan
| | - Zhengyan Kan
- Rosetta Inpharmatics LLC, Seattle, Washington, United States of America
| | - Jun Kusunoki
- Metabolic Disorder Research, Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd., Tsukuba, Ibaraki, Japan
| | - Jason M. Johnson
- Rosetta Inpharmatics LLC, Seattle, Washington, United States of America
- * E-mail: (JCC); (JMJ)
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Hiltunen JK, Schonauer MS, Autio KJ, Mittelmeier TM, Kastaniotis AJ, Dieckmann CL. Mitochondrial fatty acid synthesis type II: more than just fatty acids. J Biol Chem 2008; 284:9011-5. [PMID: 19028688 DOI: 10.1074/jbc.r800068200] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eukaryotes harbor a highly conserved mitochondrial pathway for fatty acid synthesis (FAS), which is completely independent of the eukaryotic cytosolic FAS apparatus. The activities of the mitochondrial FAS system are catalyzed by soluble enzymes, and the pathway thus resembles its prokaryotic counterparts. Except for octanoic acid, which is the direct precursor for lipoic acid synthesis, other end products and functions of the mitochondrial FAS pathway are still largely enigmatic. In addition to low cellular levels of lipoic acid, disruption of genes encoding mitochondrial FAS enzymes in yeast results in a respiratory-deficient phenotype and small rudimentary mitochondria. Recently, two distinct links between mitochondrial FAS and RNA processing have been discovered in vertebrates and yeast, respectively. In vertebrates, the mitochondrial 3-hydroxyacyl-acyl carrier protein dehydratase and the RPP14 subunit of RNase P are encoded by the same bicistronic transcript in an evolutionarily conserved arrangement that is unusual for eukaryotes. In yeast, defects in mitochondrial FAS result in inefficient RNase P cleavage in the organelle. The intersection of mitochondrial FAS and RNA metabolism in both systems provides a novel mechanism for the coordination of intermediary metabolism in eukaryotic cells.
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Affiliation(s)
- J Kalervo Hiltunen
- Department of Biochemistry and Biocenter Oulu, University of Oulu, FI-90014 Oulu, Finland.
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Van Meter KE, Stuart MK. A monoclonal antibody that inhibits translation in Sf21 cell lysates is specific for glyceraldehyde-3-phosphate dehydrogenase. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2008; 69:107-117. [PMID: 18850593 DOI: 10.1002/arch.20271] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Monoclonal antibody (Mab) 8B7 was shown in a previous study to inhibit protein translation in lysates of Sf21 cells. The antibody was thought to be specific for a 60-kDa form of elongation factor-1 alpha (EF-1alpha), primarily because the antigen immunoprecipitated by Mab 8B7 cross-reacted with Mab CBP-KK1, an antibody generated to EF-1alpha from Trypanosoma brucei. The purpose of the current study was to investigate further the antigenic specificity of Mab 8B7. The concentration of the 60-kDa antigen relative to total cellular protein proved insufficient for its definitive identification. However, subcellular fractionation of Sf21 cells yielded an additional protein of 37 kDa in the cytosolic and microsomal fractions that was reactive with Mab 8B7. The 37-kDa protein could be easily visualized by colloidal Coomassie Blue G-250 staining as a series of pI 6.9-8.4 spots on two-dimensional gels. Excision of an abundant immunoreactive spot enabled identification of the protein as glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) and protein database searching. Subsequent immunoblotting of purified rabbit skeletal muscle GAPDH with Mab 8B7 confirmed the antibody's specificity for GAPDH. Besides the pivotal role GAPDH plays in glycolysis, the enzyme has a number of noncanonical functions, including binding to mRNA and tRNA. The ability of Mab 8B7 to disrupt these lesser-known functions of GAPDH may account for the antibody's inhibitory effect on in vitro translation.
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Affiliation(s)
- Kipp E Van Meter
- Department of Microbiology/Immunology, Kirksville College of Osteopathic Medicine, A.T. Still University, 800 W. Jefferson Street, Kirksville, MO 63501, USA
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Function of heterologous Mycobacterium tuberculosis InhA, a type 2 fatty acid synthase enzyme involved in extending C20 fatty acids to C60-to-C90 mycolic acids, during de novo lipoic acid synthesis in Saccharomyces cerevisiae. Appl Environ Microbiol 2008; 74:5078-85. [PMID: 18552191 DOI: 10.1128/aem.00655-08] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We describe the physiological function of heterologously expressed Mycobacterium tuberculosis InhA during de novo lipoic acid synthesis in yeast (Saccharomyces cerevisiae) mitochondria. InhA, representing 2-trans-enoyl-acyl carrier protein reductase and the target for the front-line antituberculous drug isoniazid, is involved in the activity of dissociative type 2 fatty acid synthase (FASII) that extends associative type 1 fatty acid synthase (FASI)-derived C(20) fatty acids to form C(60)-to-C(90) mycolic acids. Mycolic acids are major constituents of the protective layer around the pathogen that contribute to virulence and resistance to certain antimicrobials. Unlike FASI, FASII is thought to be incapable of de novo biosynthesis of fatty acids. Here, the genes for InhA (Rv1484) and four similar proteins (Rv0927c, Rv3485c, Rv3530c, and Rv3559c) were expressed in S. cerevisiae etr1Delta cells lacking mitochondrial 2-trans-enoyl-thioester reductase activity. The phenotype of the yeast mutants includes the inability to produce sufficient levels of lipoic acid, form mitochondrial cytochromes, respire, or grow on nonfermentable carbon sources. Yeast etr1Delta cells expressing mitochondrial InhA were able to respire, grow on glycerol, and produce lipoic acid. Commensurate with a role in mitochondrial de novo fatty acid biosynthesis, InhA could accept in vivo much shorter acyl-thioesters (C(4) to C(8)) than was previously thought (>C(12)). Moreover, InhA functioned in the absence of AcpM or protein-protein interactions with its native FASII partners KasA, KasB, FabD, and FabH. None of the four proteins similar to InhA complemented the yeast mutant phenotype. We discuss the implications of our findings with reference to lipoic acid synthesis in M. tuberculosis and the potential use of yeast FASII mutants for investigating the physiological function of drug-targeted pathogen enzymes involved in fatty acid biosynthesis.
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Chen ZJ, Pudas R, Sharma S, Smart OS, Juffer AH, Hiltunen JK, Wierenga RK, Haapalainen AM. Structural enzymological studies of 2-enoyl thioester reductase of the human mitochondrial FAS II pathway: new insights into its substrate recognition properties. J Mol Biol 2008; 379:830-44. [PMID: 18479707 DOI: 10.1016/j.jmb.2008.04.041] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 04/15/2008] [Accepted: 04/16/2008] [Indexed: 11/19/2022]
Abstract
Structural and kinetic properties of the human 2-enoyl thioester reductase [mitochondrial enoyl-coenzyme A reductase (MECR)/ETR1] of the mitochondrial fatty acid synthesis (FAS) II pathway have been determined. The crystal structure of this dimeric enzyme (at 2.4 A resolution) suggests that the binding site for the recognition helix of the acyl carrier protein is in a groove between the two adjacent monomers. This groove is connected via the pantetheine binding cleft to the active site. The modeled mode of NADPH binding, using molecular dynamics calculations, suggests that Tyr94 and Trp311 are critical for catalysis, which is supported by enzyme kinetic data. A deep, water-filled pocket, shaped by hydrophobic and polar residues and extending away from the catalytic site, was recognized. This pocket can accommodate a fatty acyl tail of up to 16 carbons. Mutagenesis of the residues near the end of this pocket confirms the importance of this region for the binding of substrate molecules with long fatty acyl tails. Furthermore, the kinetic analysis of the wild-type MECR/ETR1 shows a bimodal distribution of catalytic efficiencies, in agreement with the notion that two major products are generated by the mitochondrial FAS II pathway.
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MESH Headings
- Acyl Carrier Protein/metabolism
- Amino Acid Sequence
- Binding Sites
- Catalytic Domain
- Crystallography, X-Ray
- Dimerization
- Fatty Acid Synthase, Type I/chemistry
- Fatty Acid Synthase, Type I/genetics
- Fatty Acid Synthase, Type I/metabolism
- Humans
- Kinetics
- Mitochondria/enzymology
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- NADH, NADPH Oxidoreductases/chemistry
- NADH, NADPH Oxidoreductases/genetics
- NADH, NADPH Oxidoreductases/metabolism
- NADP/metabolism
- Oxidoreductases Acting on CH-CH Group Donors
- Protein Conformation
- Protein Structure, Quaternary
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Sequence Homology, Amino Acid
- Substrate Specificity
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Affiliation(s)
- Zhi-Jun Chen
- Biocenter Oulu and Department of Biochemistry, University of Oulu, P.O. Box 3000, FI-90014, Oulu, Finland
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Suzuki T, Matsuzaki T, Hagiwara H, Aoki T, Takata K. Recent advances in fluorescent labeling techniques for fluorescence microscopy. Acta Histochem Cytochem 2007; 40:131-7. [PMID: 18224244 PMCID: PMC2156041 DOI: 10.1267/ahc.07023] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Accepted: 11/13/2007] [Indexed: 01/19/2023] Open
Abstract
Tremendous progress in recent computer-controlled systems for fluorescence and laser-confocal microscopy has provided us with powerful tools to visualize and analyze molecular events in the cells. Various fluorescent staining and labeling techniques have also been developed to be used with these powerful instruments. Fluorescent proteins such as green fluorescent protein (GFP) allow us to directly label particular proteins of interest in living cells. This technique has been extended over a large area of cell biology, and a variety of fluorescent protein-derived techniques have been developed to visualize the functions and conditions of the molecules within living cells. In this review, we summarize the techniques for fluorescent staining and labeling for recent fluorescence microscopy.
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Affiliation(s)
- Takeshi Suzuki
- Department of Anatomy and Cell Biology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371–8511, Japan
| | - Toshiyuki Matsuzaki
- Department of Anatomy and Cell Biology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371–8511, Japan
| | - Haruo Hagiwara
- Department of Anatomy and Cell Biology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371–8511, Japan
| | - Takeo Aoki
- Department of Anatomy and Cell Biology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371–8511, Japan
| | - Kuniaki Takata
- Department of Anatomy and Cell Biology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371–8511, Japan
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