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Uehara K, Lee WD, Stefkovich M, Biswas D, Santoleri D, Garcia Whitlock A, Quinn W, Coopersmith T, Creasy KT, Rader DJ, Sakamoto K, Rabinowitz JD, Titchenell PM. mTORC1 controls murine postprandial hepatic glycogen synthesis via Ppp1r3b. J Clin Invest 2024; 134:e173782. [PMID: 38290087 PMCID: PMC10977990 DOI: 10.1172/jci173782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 01/26/2024] [Indexed: 02/01/2024] Open
Abstract
In response to a meal, insulin drives hepatic glycogen synthesis to help regulate systemic glucose homeostasis. The mechanistic target of rapamycin complex 1 (mTORC1) is a well-established insulin target and contributes to the postprandial control of liver lipid metabolism, autophagy, and protein synthesis. However, its role in hepatic glucose metabolism is less understood. Here, we used metabolomics, isotope tracing, and mouse genetics to define a role for liver mTORC1 signaling in the control of postprandial glycolytic intermediates and glycogen deposition. We show that mTORC1 is required for glycogen synthase activity and glycogenesis. Mechanistically, hepatic mTORC1 activity promotes the feeding-dependent induction of Ppp1r3b, a gene encoding a phosphatase important for glycogen synthase activity whose polymorphisms are linked to human diabetes. Reexpression of Ppp1r3b in livers lacking mTORC1 signaling enhances glycogen synthase activity and restores postprandial glycogen content. mTORC1-dependent transcriptional control of Ppp1r3b is facilitated by FOXO1, a well characterized transcriptional regulator involved in the hepatic response to nutrient intake. Collectively, we identify a role for mTORC1 signaling in the transcriptional regulation of Ppp1r3b and the subsequent induction of postprandial hepatic glycogen synthesis.
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Affiliation(s)
- Kahealani Uehara
- Institute for Diabetes, Obesity, and Metabolism
- Biochemistry and Molecular Biophysics Graduate Group, and
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Won Dong Lee
- Lewis Sigler Institute for Integrative Genomics
- Department of Chemistry, and
- Ludwig Institute for Cancer Research, Princeton Branch, Princeton, New Jersey, USA
| | | | - Dipsikha Biswas
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Dominic Santoleri
- Institute for Diabetes, Obesity, and Metabolism
- Biochemistry and Molecular Biophysics Graduate Group, and
| | | | | | | | - Kate Townsend Creasy
- Institute for Diabetes, Obesity, and Metabolism
- Department of Medicine, Division of Translational Medicine and Human Genetics, and
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniel J. Rader
- Institute for Diabetes, Obesity, and Metabolism
- Department of Medicine, Division of Translational Medicine and Human Genetics, and
| | - Kei Sakamoto
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Joshua D. Rabinowitz
- Lewis Sigler Institute for Integrative Genomics
- Department of Chemistry, and
- Ludwig Institute for Cancer Research, Princeton Branch, Princeton, New Jersey, USA
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Paul M. Titchenell
- Institute for Diabetes, Obesity, and Metabolism
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Sukkasam N, Incharoensakdi A, Monshupanee T. Disruption of Hydrogen Gas Synthesis Enhances the Cellular Levels of NAD(P)H, Glycogen, Poly(3-hydroxybutyrate) and Photosynthetic Pigments Under Specific Nutrient Condition(s) in Cyanobacterium Synechocystis sp. PCC 6803. Plant Cell Physiol 2022; 63:135-147. [PMID: 34698867 DOI: 10.1093/pcp/pcab156] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/15/2021] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
In photoautotrophic Synechocystis sp. PCC 6803, NADPH is generated from photosynthesis and utilized in various metabolism, including the biosynthesis of glyceraldehyde 3-phosphate (the upstream substrate for carbon metabolism), poly(3-hydroxybutyrate) (PHB), photosynthetic pigments, and hydrogen gas (H2). Redirecting NADPH flow from one biosynthesis pathway to another has yet to be studied. Synechocystis's H2 synthesis, one of the pathways consuming NAD(P)H, was disrupted by the inactivation of hoxY and hoxH genes encoding the two catalytic subunits of hydrogenase. Such inactivation with a complete disruption of H2 synthesis led to 1.4-, 1.9-, and 2.1-fold increased cellular NAD(P)H levels when cells were cultured in normal medium (BG11), the medium without nitrate (-N), and the medium without phosphate (-P), respectively. After 49-52 d of cultivation in BG11 (when the nitrogen source in the media was depleted), the cells with disrupted H2 synthesis had 1.3-fold increased glycogen level compared to wild type of 83-85% (w/w dry weight), the highest level reported for cyanobacterial glycogen. The increased glycogen content observed by transmission electron microscopy was correlated with the increased levels of glucose 6-phosphate and glucose 1-phosphate, the two substrates in glycogen synthesis. Disrupted H2 synthesis also enhanced PHB accumulation up to 1.4-fold under -P and 1.6-fold under -N and increased levels of photosynthetic pigments (chlorophyll a, phycocyanin, and allophycocyanin) by 1.3- to 1.5-fold under BG11. Thus, disrupted H2 synthesis increased levels of NAD(P)H, which may be utilized for the biosynthesis of glycogen, PHB, and pigments. This strategy might be applicable for enhancing other biosynthetic pathways that utilize NAD(P)H.
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Affiliation(s)
- Nannaphat Sukkasam
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Aran Incharoensakdi
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Academy of Science, Royal Society of Thailand, Bangkok 10300, Thailand
| | - Tanakarn Monshupanee
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
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Liu X, Liu L, Wang J, Cui H, Chu H, Bi H, Zhao G, Wen J. Genome-Wide Association Study of Muscle Glycogen in Jingxing Yellow Chicken. Genes (Basel) 2020; 11:genes11050497. [PMID: 32366026 PMCID: PMC7290304 DOI: 10.3390/genes11050497] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/14/2020] [Accepted: 04/14/2020] [Indexed: 01/13/2023] Open
Abstract
Glucose metabolism plays an important role in many normal and pathological physiological processes in the body. The breakdown and synthesis of muscle glycogen provides ATP for muscle activities. A genome-wide association study for muscle glycogen was performed in 473 Jingxing yellow chickens to identify significant single nucleotide polymorphisms (SNPs) and insertions and deletions (INDELs) involved in muscle glycogen metabolism. A total of nine SNPs (p < 1/699341) and three INDELs (p < 1/755733) reached a significant level of potential association. The following results were obtained through a series of analyses, including additive effects and gene function annotation. Two significant SNPs were found in introns 12 and 13 of copine 4 (CPNE4) on chromosome 2. The wild-type and mutant individuals had significant differences in glycogen metabolism at two loci (p < 0.01 for both). Individuals carrying two mutations had increased muscle glycogen content. According to the gene annotation of chromosome 11, there is a significant INDEL in intron 6 of naked cuticle homolog 1 (NKD1). After the INDEL mutation, the glycogen content increased significantly. There was a significant difference between wild-type and mutant individuals (p < 0.01). These mutations likely affecting two genes (CPNE4 and NKD1) may affect glycogen storage in a pleiotropic manner. Gene annotation indicates that CPNE4 and NKD1 may affect the process of glucose metabolism. Our findings contribute to understanding the genetic regulation of muscle glycogen metabolism and provide theoretical support.
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Affiliation(s)
- Xiaojing Liu
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.L.); (L.L.); (J.W.); (H.C.); (G.Z.)
| | - Lu Liu
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.L.); (L.L.); (J.W.); (H.C.); (G.Z.)
| | - Jie Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.L.); (L.L.); (J.W.); (H.C.); (G.Z.)
| | - Huanxian Cui
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.L.); (L.L.); (J.W.); (H.C.); (G.Z.)
| | - Huanhuan Chu
- Yantai Dadi Animal Husbrandry Co., Ltd., Yantai 1265100, China; (H.C.); (H.B)
| | - Huijuan Bi
- Yantai Dadi Animal Husbrandry Co., Ltd., Yantai 1265100, China; (H.C.); (H.B)
| | - Guiping Zhao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.L.); (L.L.); (J.W.); (H.C.); (G.Z.)
| | - Jie Wen
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (X.L.); (L.L.); (J.W.); (H.C.); (G.Z.)
- Correspondence:
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Ishikawa Y, Miyagi A, Ishikawa T, Nagano M, Yamaguchi M, Hihara Y, Kaneko Y, Kawai-Yamada M. One of the NAD kinases, sll1415, is required for the glucose metabolism of Synechocystis sp. PCC 6803. Plant J 2019; 98:654-666. [PMID: 30693583 DOI: 10.1111/tpj.14262] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 01/09/2019] [Accepted: 01/18/2019] [Indexed: 05/04/2023]
Abstract
Pyridine nucleotides (NAD(P)(H)) are electron carriers that are the driving forces in various metabolic pathways. Phosphorylation of NAD(H) to NADP(H) is performed by the enzyme NAD kinase (NADK). Synechocystis sp. PCC 6803 harbors two genes (sll1415 and slr0400) that encode proteins with NADK homology. When genetic mutants for sll1415 and slr0400 (Δ1415 and Δ0400, respectively) were cultured under photoheterotrophic growth conditions only the Δ1415 cells showed a growth defect. In wild-type cells, the sll1415 transcript accumulated after the cells were transferred to photoheterotrophic conditions. Furthermore, NAD(P)(H) measurements demonstrated that a dynamic metabolic conversion was implemented during the adaptation from photoautotrophic to photoheterotrophic conditions. Electron microscopy observation and biochemistry quantification demonstrated the accumulation of glycogen in the Δ1415 cells under photoheterotrophic conditions at 96 h. Quantitative real-time reverse transcription PCR (qRT-PCR) demonstrated the accumulation of mRNAs that encoded glycogen biosynthesis-related enzymes in photoheterotrophic Δ1415 cells. At 96 h, enzyme activity measurement in the photoheterotrophic Δ1415 cells demonstrated that the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were decreased, but the activities of glucose dehydrogenase were increased. Furthermore, metabolomics analysis demonstrated that the Δ1415 cells showed increased glucose-6-phosphate and 6-phosphogluconate content at 96 h. Therefore, sll1415 has a significant function in the oxidative pentose phosphate (OPP) pathway for catabolism of glucose under photoheterotrophic conditions. Additionally, it is presumed that the slr0400 had a different role in glucose catabolism during growth. These results suggest that the two Synechocystis sp. PCC 6803 NADKs (Sll1415 and Slr0400) have distinct functions in photoheterotrophic cyanobacterial metabolism.
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Affiliation(s)
- Yuuma Ishikawa
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan
| | - Atsuko Miyagi
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan
| | - Toshiki Ishikawa
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan
| | - Minoru Nagano
- Graduate School of Science, Ritsumeikan University, Kusatsu, Japan
| | - Masatoshi Yamaguchi
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan
| | - Yukako Hihara
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan
| | - Yasuko Kaneko
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan
| | - Maki Kawai-Yamada
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-ku, Saitama-city, Saitama, 338-8570, Japan
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Amiñoso C, Gordillo-Marañón M, Hernández J, Solera J. Reevaluating the pathogenicity of the mutation c.1194 +5 G>A in GAA gene by functional analysis of RNA in a 61-year-old woman diagnosed with Pompe disease by muscle biopsy. Neuromuscul Disord 2019; 29:187-191. [PMID: 30770309 DOI: 10.1016/j.nmd.2018.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/05/2018] [Accepted: 12/09/2018] [Indexed: 11/18/2022]
Abstract
Glycogen storage disease type II, or Pompe disease, is an autosomal recessive disorder caused by deficiency of lysosomal acid alpha-glucosidase (GAA). We performed genetic analysis to confirm the diagnosis of Pompe disease in a 61-year-old patient with progressive weakness in extremities, severe Sleep Apnea-Hypopnea Syndrome, a significant reduction of alpha-glucosidase in liquid sample of peripheral blood and muscular biopsy diagnosis. GAA gene sequencing showed the patient is homozygous for the splice-site mutation c.1194+5G>A, considered as nonpathogenic in Pompe Center mutation database. Further molecular RNA characterization of GAA transcripts allowed us to identify abnormal processing of pre-mRNA, leading to aberrant transcripts and a significant reduction of GAA mRNA levels. Our results indicate that c.1194+5G>A is a pathogenic splice-site mutation and should be considered as such for diagnostic purposes. This study emphasizes the potential role of functional studies to determine the consequences of mutations with no evident pathogenicity.
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Affiliation(s)
- Cinthia Amiñoso
- Unidad de Oncogenética Molecular, Instituto de Genética Médica y Molecular (INGEMM), Edificio Quirúrgico Planta-2, Hospital Universitario La Paz, 28046 Madrid, Spain
| | - María Gordillo-Marañón
- Unidad de Oncogenética Molecular, Instituto de Genética Médica y Molecular (INGEMM), Edificio Quirúrgico Planta-2, Hospital Universitario La Paz, 28046 Madrid, Spain; Institute of Cardiovascular Science, Faculty of Population Health, University College London, London WC1E 6BT, UK
| | - Jaime Hernández
- Neurology Department, University General Hospital of Guadalajara, Spain
| | - Jesús Solera
- Unidad de Oncogenética Molecular, Instituto de Genética Médica y Molecular (INGEMM), Edificio Quirúrgico Planta-2, Hospital Universitario La Paz, 28046 Madrid, Spain; Department of Biochemistry, Faculty of Medicine, Autonoma University of Madrid, 28046 Madrid, Spain.
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6
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Parchem JG, Kanasaki K, Kanasaki M, Sugimoto H, Xie L, Hamano Y, Lee SB, Gattone VH, Parry S, Strauss JF, Garovic VD, McElrath TF, Lu KH, Sibai BM, LeBleu VS, Carmeliet P, Kalluri R. Loss of placental growth factor ameliorates maternal hypertension and preeclampsia in mice. J Clin Invest 2018; 128:5008-5017. [PMID: 30179860 PMCID: PMC6205389 DOI: 10.1172/jci99026] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 08/28/2018] [Indexed: 12/28/2022] Open
Abstract
Preeclampsia remains a clinical challenge due to its poorly understood pathogenesis. A prevailing notion is that increased placental production of soluble fms-like tyrosine kinase-1 (sFlt-1) causes the maternal syndrome by inhibiting proangiogenic placental growth factor (PlGF) and VEGF. However, the significance of PlGF suppression in preeclampsia is uncertain. To test whether preeclampsia results from the imbalance of angiogenic factors reflected by an abnormal sFlt-1/PlGF ratio, we studied PlGF KO (Pgf-/-) mice and noted that the mice did not develop signs or sequelae of preeclampsia despite a marked elevation in circulating sFLT-1. Notably, PlGF KO mice had morphologically distinct placentas, showing an accumulation of junctional zone glycogen. We next considered the role of placental PlGF in an established model of preeclampsia (pregnant catechol-O-methyltransferase-deficient [COMT-deficient] mice) by generating mice with deletions in both the Pgf and Comt genes. Deletion of placental PlGF in the context of COMT loss resulted in a reduction in maternal blood pressure and increased placental glycogen, indicating that loss of PlGF might be protective against the development of preeclampsia. These results identify a role for PlGF in placental development and support a complex model for the pathogenesis of preeclampsia beyond an angiogenic factor imbalance.
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Affiliation(s)
- Jacqueline G Parchem
- Department of Cancer Biology, Metastasis Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Department of Obstetrics, Gynecology and Reproductive Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas, USA
| | - Keizo Kanasaki
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Megumi Kanasaki
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Hikaru Sugimoto
- Department of Cancer Biology, Metastasis Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Liang Xie
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Yuki Hamano
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Soo Bong Lee
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Vincent H Gattone
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Samuel Parry
- Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jerome F Strauss
- Department of Obstetrics and Gynecology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Vesna D Garovic
- Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Thomas F McElrath
- Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Karen H Lu
- Department of Gynecologic Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Baha M Sibai
- Department of Obstetrics, Gynecology and Reproductive Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Valerie S LeBleu
- Department of Cancer Biology, Metastasis Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, Katholieke Universiteit (KU) Leuven, Leuven, Belgium
- Laboratory of Angiogenesis and Vascular Metabolism, Vesalius Research Center, Center for Cancer Biology (CCB), Vlaams Instituut voor Biotechnologie (VIB), Leuven, Belgium
| | - Raghu Kalluri
- Department of Cancer Biology, Metastasis Research Center, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
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Cairns R, Fischer AW, Blanco-Munoz P, Alvarez-Guaita A, Meneses-Salas E, Egert A, Buechler C, Hoy AJ, Heeren J, Enrich C, Rentero C, Grewal T. Altered hepatic glucose homeostasis in AnxA6-KO mice fed a high-fat diet. PLoS One 2018; 13:e0201310. [PMID: 30110341 PMCID: PMC6093612 DOI: 10.1371/journal.pone.0201310] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 07/12/2018] [Indexed: 12/12/2022] Open
Abstract
Annexin A6 (AnxA6) controls cholesterol and membrane transport in endo- and exocytosis, and modulates triglyceride accumulation and storage. In addition, AnxA6 acts as a scaffolding protein for negative regulators of growth factor receptors and their effector pathways in many different cell types. Here we investigated the role of AnxA6 in the regulation of whole body lipid metabolism and insulin-regulated glucose homeostasis. Therefore, wildtype (WT) and AnxA6-knockout (KO) mice were fed a high-fat diet (HFD) for 17 weeks. During the course of HFD feeding, AnxA6-KO mice gained less weight compared to controls, which correlated with reduced adiposity. Systemic triglyceride and cholesterol levels of HFD-fed control and AnxA6-KO mice were comparable, with slightly elevated high density lipoprotein (HDL) and reduced triglyceride-rich lipoprotein (TRL) levels in AnxA6-KO mice. AnxA6-KO mice displayed a trend towards improved insulin sensitivity in oral glucose and insulin tolerance tests (OGTT, ITT), which correlated with increased insulin-inducible phosphorylation of protein kinase B (Akt) and ribosomal protein S6 kinase (S6) in liver extracts. However, HFD-fed AnxA6-KO mice failed to downregulate hepatic gluconeogenesis, despite similar insulin levels and insulin signaling activity, as well as expression profiles of insulin-sensitive transcription factors to controls. In addition, increased glycogen storage in livers of HFD- and chow-fed AnxA6-KO animals was observed. Together with an inability to reduce glucose production upon insulin exposure in AnxA6-depleted HuH7 hepatocytes, this implicates AnxA6 contributing to the fine-tuning of hepatic glucose metabolism with potential consequences for the systemic control of glucose in health and disease.
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Affiliation(s)
- Rose Cairns
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Alexander W. Fischer
- Department of Biochemistry and Molecular Biology II: Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Patricia Blanco-Munoz
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Anna Alvarez-Guaita
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Elsa Meneses-Salas
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Antonia Egert
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Christa Buechler
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Andrew J. Hoy
- Discipline of Physiology, School of Medical Science, Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
| | - Joerg Heeren
- Department of Biochemistry and Molecular Biology II: Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
- * E-mail: (TG); (CR)
| | - Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- * E-mail: (TG); (CR)
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Shulman RG, Rothman DL. The Glycogen Shunt Maintains Glycolytic Homeostasis and the Warburg Effect in Cancer. Trends Cancer 2017; 3:761-767. [PMID: 29120752 DOI: 10.1016/j.trecan.2017.09.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 09/21/2017] [Accepted: 09/22/2017] [Indexed: 10/18/2022]
Abstract
Despite many decades of study there is a lack of a quantitative explanation for the Warburg effect in cancer. We propose that the glycogen shunt, a pathway recently shown to be critical for cancer cell survival, may explain the excess lactate generation under aerobic conditions characteristic of the Warburg effect. The proposal is based on research on yeast and mammalian muscle and brain that demonstrates that the glycogen shunt functions to maintain homeostasis of glycolytic intermediates and ATP during large shifts in glucose supply or demand. Loss of the glycogen shunt leads to cell death under substrate stress. Similarities between the glycogen shunt in yeast and cancer cells lead us here to propose a parallel explanation of the lactate produced by cancer cells in the Warburg effect. The model also explains the need for the active tetramer and inactive dimer forms of pyruvate kinase (PKM2) in cancer cells, similar to the two forms of Pyk2p in yeast, as critical for regulating the glycogen shunt flux. The novel role proposed for the glycogen shunt implicates the high activities of glycogen synthase and fructose bisphosphatase in tumors as potential targets for therapy.
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Affiliation(s)
- Robert G Shulman
- Departments of Radiology and Biomedical Engineering, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Douglas L Rothman
- Departments of Radiology and Biomedical Engineering, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, CT 06520, USA.
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9
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Qin Y, Zhao L, Wang X, Tong D, Hoover C, Wu F, Liu Y, Wang L, Liu L, Ni L, Song T, Huang C. MeCP2 regulated glycogenes contribute to proliferation and apoptosis of gastric cancer cells. Glycobiology 2017; 27:306-317. [PMID: 28100567 DOI: 10.1093/glycob/cwx006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 01/16/2017] [Indexed: 11/14/2022] Open
Abstract
Aberrant glycogene and glycan expression is intimately associated with carcinogenesis, invasion, and metastasis of gastric cancer (GC); however the regulatory mechanisms for glycogenes in GC cells remain unclear. Methyl-CpG-binding protein 2 (MeCP2) regulates genes by binding to methylated promoters, and in our previous work we found that it is overexpressed in GC cell lines and tissues, functioning as an oncogene. In this study we detected the expression of 212 glycogenes in MeCP2 silenced GC cells versus control using the Agilent Whole Human Genome Microarray and mining the data through bioinformatic analysis. A total of 10 glycogenes exhibited increased expression (FC ≥ 2, P < 0.05), while 16 showed decreased expression (FC ≤ 2, P < 0.05) in the MeCP2 silenced cells, which corresponded to down-regulation of Lewis antigens (UEA-I), T/Tn antigens (PNA), and mature N-glycans (PHA-E and PHA-E+L) and up-regulation of lactosylceramide, a precursor oligosaccharide of N-glycans. Examination of the TCGA Gastric Cancer databases demonstrated that nine glycogenes (24.6%) were oppositely regulated by MeCP2 in MeCP2 knockdown BGC-823 cells relative to their expression level in GC tissues, and might be downstream genes of MeCP2. Individual gene analysis suggested that neutral alpha-glucosidase AB (GANAB) knockdown can rescue the effects of MeCP2 overexpression on GC cells. MeCP2 promotes GANAB by binding to the second methylated CpG island (206 bp, -12916 to -13122) of the GANAB promoter. In conclusion, glycogenes can be either up- or down-regulated by MeCP2 directly or indirectly to alter the glycopatterning and affect the proliferation and apoptosis of GC cells.
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Affiliation(s)
- Yannan Qin
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an, PR China
| | - Lingyu Zhao
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an, PR China
| | - Xiaofei Wang
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an, PR China
| | - Dongdong Tong
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an, PR China
| | - Christopher Hoover
- Department of Biochemistry and Molecular Biology, University of OklahomaHealth Science Center, Oklahoma City, OK, USA
| | - Fei Wu
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an, PR China
| | - Yingxun Liu
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an, PR China
| | - Lumin Wang
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an, PR China
| | - Liying Liu
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an, PR China
| | - Lei Ni
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
| | - Tusheng Song
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
| | - Chen Huang
- Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, PR China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an, PR China
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10
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Hedberg-Oldfors C, Glamuzina E, Ruygrok P, Anderson LJ, Elliott P, Watkinson O, Occleshaw C, Abernathy M, Turner C, Kingston N, Murphy E, Oldfors A. Cardiomyopathy as presenting sign of glycogenin-1 deficiency-report of three cases and review of the literature. J Inherit Metab Dis 2017; 40:139-149. [PMID: 27718144 PMCID: PMC5203857 DOI: 10.1007/s10545-016-9978-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 09/01/2016] [Accepted: 09/12/2016] [Indexed: 01/19/2023]
Abstract
We describe a new type of cardiomyopathy caused by a mutation in the glycogenin-1 gene (GYG1). Three unrelated male patients aged 34 to 52 years with cardiomyopathy and abnormal glycogen storage on endomyocardial biopsy were homozygous for the missense mutation p.Asp102His in GYG1. The mutated glycogenin-1 protein was expressed in cardiac tissue but had lost its ability to autoglucosylate as demonstrated by an in vitro assay and western blot analysis. It was therefore unable to form the primer for normal glycogen synthesis. Two of the patients showed similar patterns of heart dilatation, reduced ejection fraction and extensive late gadolinium enhancement on cardiac magnetic resonance imaging. These two patients were severely affected, necessitating cardiac transplantation. The cardiomyocyte storage material was characterized by large inclusions of periodic acid and Schiff positive material that was partly resistant to alpha-amylase treatment consistent with polyglucosan. The storage material had, unlike normal glycogen, a partly fibrillar structure by electron microscopy. None of the patients showed signs or symptoms of muscle weakness but a skeletal muscle biopsy in one case revealed muscle fibres with abnormal glycogen storage. Glycogenin-1 deficiency is known as a rare cause of skeletal muscle glycogen storage disease, usually without cardiomyopathy. We demonstrate that it may also be the cause of severe cardiomyopathy and cardiac failure without skeletal muscle weakness. GYG1 should be included in cardiomyopathy gene panels.
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Affiliation(s)
| | - Emma Glamuzina
- National Metabolic Service, Starship Children’s Hospital, Auckland, New Zealand
| | - Peter Ruygrok
- Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand
| | | | | | | | - Chris Occleshaw
- Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand
| | | | - Clinton Turner
- Anatomical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Nicola Kingston
- Anatomical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Elaine Murphy
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Anders Oldfors
- Department of Pathology and Genetics, University of Gothenburg, Gothenburg, Sweden
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11
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Petersen MC, Madiraju AK, Gassaway BM, Marcel M, Nasiri AR, Butrico G, Marcucci MJ, Zhang D, Abulizi A, Zhang XM, Philbrick W, Hubbard SR, Jurczak MJ, Samuel VT, Rinehart J, Shulman GI. Insulin receptor Thr1160 phosphorylation mediates lipid-induced hepatic insulin resistance. J Clin Invest 2016; 126:4361-4371. [PMID: 27760050 DOI: 10.1172/jci86013] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 09/08/2016] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a risk factor for type 2 diabetes (T2D), but whether NAFLD plays a causal role in the pathogenesis of T2D is uncertain. One proposed mechanism linking NAFLD to hepatic insulin resistance involves diacylglycerol-mediated (DAG-mediated) activation of protein kinase C-ε (PKCε) and the consequent inhibition of insulin receptor (INSR) kinase activity. However, the molecular mechanism underlying PKCε inhibition of INSR kinase activity is unknown. Here, we used mass spectrometry to identify the phosphorylation site Thr1160 as a PKCε substrate in the functionally critical INSR kinase activation loop. We hypothesized that Thr1160 phosphorylation impairs INSR kinase activity by destabilizing the active configuration of the INSR kinase, and our results confirmed this prediction by demonstrating severely impaired INSR kinase activity in phosphomimetic T1160E mutants. Conversely, the INSR T1160A mutant was not inhibited by PKCε in vitro. Furthermore, mice with a threonine-to-alanine mutation at the homologous residue Thr1150 (InsrT1150A mice) were protected from high fat diet-induced hepatic insulin resistance. InsrT1150A mice also displayed increased insulin signaling, suppression of hepatic glucose production, and increased hepatic glycogen synthesis compared with WT controls during hyperinsulinemic clamp studies. These data reveal a critical pathophysiological role for INSR Thr1160 phosphorylation and provide further mechanistic links between PKCε and INSR in mediating NAFLD-induced hepatic insulin resistance.
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12
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Murovets VO, Sozontov EA, Andreeva JV, Khropycheva RP, Zolotarev VA. [EFFECT OF T1R3 RECEPTOR PROTEIN DELETION ON GLUCONEOGENESIS AND LIPID METABOLISM IN MICE]. Ross Fiziol Zh Im I M Sechenova 2016; 102:668-679. [PMID: 30192493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Receptors of the T1R family are molecular sensors for sweet taste stimuli. They are expressed not only in the oral cavity, but in most of endocrine cells controlling homeostasis of glucose as well as in adipocytes. Earlier, we have demonstrated that deletion of the Taslr3 gene, which encodes the T1R3 protein, reduces glucose tolerance, elevates insulin resistance and cause a decrease of blood glucose level after food deprivation. The goal of the study was to elucidate an involvement of T1R3 in control of endogenous glucose synthesis and lipid metabolism. Experiments were performed with an inbred mouse strain C57BL/6ByJ and the Taslr3-gene knockout strain C57BL/6J-Tas1r3tm1Rfm maintained at the normocaloric diet. It was shown in vivo that the presence of intact T1R3 stimulates gluconeogenesis and lipid utilization during starvation and likely promotes glycogen synthesis. Additionally, T1R3 potentiates utilization of triglycerides and glycerol (in fed state) and restricts secretion of glucagon during fasting but does not affect insulin output. Thus, T1R3-mediated visceral reception of metabolites is involved in control of carbohydrate and lipid metabolism.
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13
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Boehm A, Arnoldini M, Bergmiller T, Röösli T, Bigosch C, Ackermann M. Genetic Manipulation of Glycogen Allocation Affects Replicative Lifespan in E. coli. PLoS Genet 2016; 12:e1005974. [PMID: 27093302 PMCID: PMC4836754 DOI: 10.1371/journal.pgen.1005974] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/13/2016] [Indexed: 11/18/2022] Open
Abstract
In bacteria, replicative aging manifests as a difference in growth or survival between the two cells emerging from division. One cell can be regarded as an aging mother with a decreased potential for future survival and division, the other as a rejuvenated daughter. Here, we aimed at investigating some of the processes involved in aging in the bacterium Escherichia coli, where the two types of cells can be distinguished by the age of their cell poles. We found that certain changes in the regulation of the carbohydrate metabolism can affect aging. A mutation in the carbon storage regulator gene, csrA, leads to a dramatically shorter replicative lifespan; csrA mutants stop dividing once their pole exceeds an age of about five divisions. These old-pole cells accumulate glycogen at their old cell poles; after their last division, they do not contain a chromosome, presumably because of spatial exclusion by the glycogen aggregates. The new-pole daughters produced by these aging mothers are born young; they only express the deleterious phenotype once their pole is old. These results demonstrate how manipulations of nutrient allocation can lead to the exclusion of the chromosome and limit replicative lifespan in E. coli, and illustrate how mutations can have phenotypic effects that are specific for cells with old poles. This raises the question how bacteria can avoid the accumulation of such mutations in their genomes over evolutionary times, and how they can achieve the long replicative lifespans that have recently been reported. Bacteria were often considered to be potentially immortal and free of aging. This expectation was based on the idea that the two cells emerging from bacterial division are identical and thus also equally old. However, a number of recent studies followed individual bacterial cells over consecutive divisions and reported that individuals with old cell poles show reduced survival and growth. This indicates that at least some types of bacteria age. We were interested in how mutations can affect the aging process and replicative lifespan of bacteria. In eukaryotes the aging process is thought to be modulated by mutations with age-specific effects. For example, there are mutations that have no measureable phenotypic effect early in life but are deleterious later in life. Such mutations play a key role in the evolution of eukaryotic aging and are thought to be responsible for lifespan differences between species. Here, we report that mutations can also have age-specific effects in bacteria. We describe a mutation in E. coli with a deleterious effect on growth and division that only manifests in cells whose cell pole is about four to five divisions old. These results illustrate how mutations can act in an age-specific manner in bacteria, and raise questions about how bacterial lifespan is modulated by such mutations.
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Affiliation(s)
- Alex Boehm
- Biozentrum, University of Basel, Switzerland
- Philipps-Universität Marburg, LOEWE-Zentrum für Synthetische Mikrobiologie, Marburg, Germany
| | - Markus Arnoldini
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Switzerland
- Department of Environmental Microbiology, Eawag, Dübendorf, Switzerland
- Department of Physics, University of California, San Diego, La Jolla, United States of America
| | - Tobias Bergmiller
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Switzerland
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Thomas Röösli
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Switzerland
- Department of Environmental Microbiology, Eawag, Dübendorf, Switzerland
| | - Colette Bigosch
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Switzerland
- Department of Environmental Microbiology, Eawag, Dübendorf, Switzerland
| | - Martin Ackermann
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Switzerland
- Department of Environmental Microbiology, Eawag, Dübendorf, Switzerland
- * E-mail:
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14
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Possik E, Ajisebutu A, Manteghi S, Gingras MC, Vijayaraghavan T, Flamand M, Coull B, Schmeisser K, Duchaine T, van Steensel M, Hall DH, Pause A. FLCN and AMPK Confer Resistance to Hyperosmotic Stress via Remodeling of Glycogen Stores. PLoS Genet 2015; 11:e1005520. [PMID: 26439621 PMCID: PMC4595296 DOI: 10.1371/journal.pgen.1005520] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/21/2015] [Indexed: 01/06/2023] Open
Abstract
Mechanisms of adaptation to environmental changes in osmolarity are fundamental for cellular and organismal survival. Here we identify a novel osmotic stress resistance pathway in Caenorhabditis elegans (C. elegans), which is dependent on the metabolic master regulator 5'-AMP-activated protein kinase (AMPK) and its negative regulator Folliculin (FLCN). FLCN-1 is the nematode ortholog of the tumor suppressor FLCN, responsible for the Birt-Hogg-Dubé (BHD) tumor syndrome. We show that flcn-1 mutants exhibit increased resistance to hyperosmotic stress via constitutive AMPK-dependent accumulation of glycogen reserves. Upon hyperosmotic stress exposure, glycogen stores are rapidly degraded, leading to a significant accumulation of the organic osmolyte glycerol through transcriptional upregulation of glycerol-3-phosphate dehydrogenase enzymes (gpdh-1 and gpdh-2). Importantly, the hyperosmotic stress resistance in flcn-1 mutant and wild-type animals is strongly suppressed by loss of AMPK, glycogen synthase, glycogen phosphorylase, or simultaneous loss of gpdh-1 and gpdh-2 enzymes. Our studies show for the first time that animals normally exhibit AMPK-dependent glycogen stores, which can be utilized for rapid adaptation to either energy stress or hyperosmotic stress. Importantly, we show that glycogen accumulates in kidneys from mice lacking FLCN and in renal tumors from a BHD patient. Our findings suggest a dual role for glycogen, acting as a reservoir for energy supply and osmolyte production, and both processes might be supporting tumorigenesis.
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Affiliation(s)
- Elite Possik
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Andrew Ajisebutu
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Sanaz Manteghi
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Marie-Claude Gingras
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Tarika Vijayaraghavan
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Mathieu Flamand
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
| | - Barry Coull
- College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kathrin Schmeisser
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Thomas Duchaine
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Maurice van Steensel
- College of Life Sciences, University of Dundee, Dundee, United Kingdom
- Institute of Medical Biology, Singapore, Singapore
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Arnim Pause
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
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15
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Gsell M, Fankl A, Klug L, Mascher G, Schmidt C, Hrastnik C, Zellnig G, Daum G. A Yeast Mutant Deleted of GPH1 Bears Defects in Lipid Metabolism. PLoS One 2015; 10:e0136957. [PMID: 26327557 PMCID: PMC4556709 DOI: 10.1371/journal.pone.0136957] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 08/10/2015] [Indexed: 11/18/2022] Open
Abstract
In a previous study we demonstrated up-regulation of the yeast GPH1 gene under conditions of phosphatidylethanolamine (PE) depletion caused by deletion of the mitochondrial (M) phosphatidylserine decarboxylase 1 (PSD1) (Gsell et al., 2013, PLoS One. 8(10):e77380. doi: 10.1371/journal.pone.0077380). Gph1p has originally been identified as a glycogen phosphorylase catalyzing degradation of glycogen to glucose in the stationary growth phase of the yeast. Here we show that deletion of this gene also causes decreased levels of phosphatidylcholine (PC), triacylglycerols and steryl esters. Depletion of the two non-polar lipids in a Δgph1 strain leads to lack of lipid droplets, and decrease of the PC level results in instability of the plasma membrane. In vivo labeling experiments revealed that formation of PC via both pathways of biosynthesis, the cytidine diphosphate (CDP)-choline and the methylation route, is negatively affected by a Δgph1 mutation, although expression of genes involved is not down regulated. Altogether, Gph1p besides its function as a glycogen mobilizing enzyme appears to play a regulatory role in yeast lipid metabolism.
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Affiliation(s)
- Martina Gsell
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Ariane Fankl
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Lisa Klug
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Gerald Mascher
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Claudia Schmidt
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Claudia Hrastnik
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
| | - Günther Zellnig
- Institute of Plant Sciences, Karl Franzens University Graz, NaWi Graz, Austria
| | - Günther Daum
- Institute of Biochemistry, Graz University of Technology, NaWi Graz, Petersgasse 12/2, 8010, Graz, Austria
- * E-mail:
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16
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Abstract
Glycogen is the storage form of glucose in animal cells. Its degradation can rapidly provide fuel for energy production (particularly important in muscle), or replenish blood glucose during fasting by the liver. Genetic defects of glycogen metabolism give rise to glycogen storage diseases (GSDs), manifesting histologically in abnormal quantity or quality of glycogen in the cells. GSDs can be caused by defects of proteins participating in the synthesis or degradation of glycogen itself, in the glycolytic degradation of glucose phosphates in muscle and erythrocytes, in the release of glucose from liver and kidney into the bloodstream, in the clearance of glycogen from lysosomes (all, "primary GSDs"), or in the control of these pathways ("secondary GSDs"). Most genes responsible for classical, primary GSDs have probably been identified, and future progress in understanding the biochemical and genetic defects underlying unsolved disorders presenting with glycogen storage abnormalities will perhaps be predominantly in the field of secondary GSDs.
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Affiliation(s)
- Manfred W Kilimann
- Department of Otolaryngology, Göttingen University Medical School, Goettingen, Germany,
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17
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Cupertino FB, Virgilio S, Freitas FZ, Candido TDS, Bertolini MC. Regulation of glycogen metabolism by the CRE-1, RCO-1 and RCM-1 proteins in Neurospora crassa. The role of CRE-1 as the central transcriptional regulator. Fungal Genet Biol 2015; 77:82-94. [PMID: 25889113 DOI: 10.1016/j.fgb.2015.03.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/30/2015] [Accepted: 03/31/2015] [Indexed: 11/17/2022]
Abstract
The transcription factor CreA/Mig1/CRE-1 is a repressor protein that regulates the use of alternative carbon sources via a mechanism known as Carbon Catabolite Repression (CCR). In Saccharomyces cerevisiae, Mig1 recruits the complex Ssn6-Tup1, the Neurospora crassa RCM-1 and RCO-1 orthologous proteins, respectively, to bind to promoters of glucose-repressible genes. We have been studying the regulation of glycogen metabolism in N. crassa and the identification of the RCO-1 corepressor as a regulator led us to investigate the regulatory role of CRE-1 in this process. Glycogen content is misregulated in the rco-1(KO), rcm-1(RIP) and cre-1(KO) strains, and the glycogen synthase phosphorylation is decreased in all strains, showing that CRE-1, RCO-1 and RCM-1 proteins are involved in glycogen accumulation and in the regulation of GSN activity by phosphorylation. We also confirmed the regulatory role of CRE-1 in CCR and its nuclear localization under repressing condition in N. crassa. The expression of all glycogenic genes is misregulated in the cre-1(KO) strain, suggesting that CRE-1 also controls glycogen metabolism by regulating gene expression. The existence of a high number of the Aspergillus nidulans CreA motif (5'-SYGGRG-3') in the glycogenic gene promoters led us to analyze the binding of CRE-1 to some DNA motifs both in vitro by DNA gel shift and in vivo by ChIP-qPCR analysis. CRE-1 bound in vivo to all motifs analyzed demonstrating that it down-regulates glycogen metabolism by controlling gene expression and GSN phosphorylation.
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Affiliation(s)
- Fernanda Barbosa Cupertino
- Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, UNESP, 14800-060 Araraquara, SP, Brazil
| | - Stela Virgilio
- Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, UNESP, 14800-060 Araraquara, SP, Brazil
| | - Fernanda Zanolli Freitas
- Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, UNESP, 14800-060 Araraquara, SP, Brazil
| | - Thiago de Souza Candido
- Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, UNESP, 14800-060 Araraquara, SP, Brazil
| | - Maria Célia Bertolini
- Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, UNESP, 14800-060 Araraquara, SP, Brazil.
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18
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Corral-Ramos C, Roncero MIG. Glycogen catabolism, but not its biosynthesis, affects virulence of Fusarium oxysporum on the plant host. Fungal Genet Biol 2015; 77:40-9. [PMID: 25865793 DOI: 10.1016/j.fgb.2015.03.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 03/18/2015] [Accepted: 03/19/2015] [Indexed: 11/18/2022]
Abstract
The role of glycogen metabolism was investigated in the fungal pathogen Fusarium oxysporum. Targeted inactivation was performed of genes responsible for glycogen biosynthesis: gnn1 encoding glycogenin, gls1 encoding glycogen synthase, and gbe1 encoding glycogen branching enzyme. Moreover genes involved in glycogen catabolism were deleted: gph1 encoding glycogen phosphorylase and gdb1 encoding glycogen de-branching enzyme. Glycogen reserves increased steadily during growth of the wild type strain in axenic cultures, to reach up to 1500μg glucose equivalents mg(-1) protein after 14 days. Glycogen accumulation was abolished in mutants lacking biosynthesis genes, whereas it increased by 20-40% or 80%, respectively, in the single and double mutants affected in catabolic genes. Transcript levels of glycogen metabolism genes during tomato plant infection peaked at four days post inoculation, similar to the results observed during axenic culture. Significant differences were observed between gdb mutants and the wild type strain for vegetative hyphal fusion ability. The single mutants defective in glycogen metabolism showed similar levels of virulence in the invertebrate animal model Galleria mellonella. Interestingly, the deletion of gdb1 reduced virulence on the plant host up to 40% compared to the wild type in single and in double mutant backgrounds, whereas the other mutants showed the virulence at the wild-type level.
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Affiliation(s)
- Cristina Corral-Ramos
- Departamento de Genetica, Universidad de Córdoba and Campus de Excelencia Agroalimentario (ceiA3), E-14071 Cordoba, Spain
| | - M Isabel G Roncero
- Departamento de Genetica, Universidad de Córdoba and Campus de Excelencia Agroalimentario (ceiA3), E-14071 Cordoba, Spain.
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Almagro G, Viale AM, Montero M, Rahimpour M, Muñoz FJ, Baroja-Fernández E, Bahaji A, Zúñiga M, González-Candelas F, Pozueta-Romero J. Comparative genomic and phylogenetic analyses of Gammaproteobacterial glg genes traced the origin of the Escherichia coli glycogen glgBXCAP operon to the last common ancestor of the sister orders Enterobacteriales and Pasteurellales. PLoS One 2015; 10:e0115516. [PMID: 25607991 PMCID: PMC4301808 DOI: 10.1371/journal.pone.0115516] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 11/25/2014] [Indexed: 12/22/2022] Open
Abstract
Production of branched α-glucan, glycogen-like polymers is widely spread in the Bacteria domain. The glycogen pathway of synthesis and degradation has been fairly well characterized in the model enterobacterial species Escherichia coli (order Enterobacteriales, class Gammaproteobacteria), in which the cognate genes (branching enzyme glgB, debranching enzyme glgX, ADP-glucose pyrophosphorylase glgC, glycogen synthase glgA, and glycogen phosphorylase glgP) are clustered in a glgBXCAP operon arrangement. However, the evolutionary origin of this particular arrangement and of its constituent genes is unknown. Here, by using 265 complete gammaproteobacterial genomes we have carried out a comparative analysis of the presence, copy number and arrangement of glg genes in all lineages of the Gammaproteobacteria. These analyses revealed large variations in glg gene presence, copy number and arrangements among different gammaproteobacterial lineages. However, the glgBXCAP arrangement was remarkably conserved in all glg-possessing species of the orders Enterobacteriales and Pasteurellales (the E/P group). Subsequent phylogenetic analyses of glg genes present in the Gammaproteobacteria and in other main bacterial groups indicated that glg genes have undergone a complex evolutionary history in which horizontal gene transfer may have played an important role. These analyses also revealed that the E/P glgBXCAP genes (a) share a common evolutionary origin, (b) were vertically transmitted within the E/P group, and (c) are closely related to glg genes of some phylogenetically distant betaproteobacterial species. The overall data allowed tracing the origin of the E. coli glgBXCAP operon to the last common ancestor of the E/P group, and also to uncover a likely glgBXCAP transfer event from the E/P group to particular lineages of the Betaproteobacteria.
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Affiliation(s)
- Goizeder Almagro
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Alejandro M. Viale
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, 2000 Rosario, Argentina
| | - Manuel Montero
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Mehdi Rahimpour
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Francisco José Muñoz
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Edurne Baroja-Fernández
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Abdellatif Bahaji
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
| | - Manuel Zúñiga
- Dpt. Biotecnología de Alimentos, Instituto de Agroquímica y Tecnología de Alimentos, CSIC, Calle Agustín Escardino, 7, 46980 Paterna, Valencia, Spain
| | - Fernando González-Candelas
- Unidad Mixta Genómica y Salud, FISABIO-Salud Pública/Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universidad de Valencia, Calle Catedrático José Beltrán Martínez, 246980 Paterna, Valencia, Spain
| | - Javier Pozueta-Romero
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra), Iruñako etorbidea 123, 31192 Mutiloabeti, Nafarroa, Spain
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Ma J, Yang J, Zhou L, Ren J, Liu X, Zhang H, Yang B, Zhang Z, Ma H, Xie X, Xing Y, Guo Y, Huang L. A splice mutation in the PHKG1 gene causes high glycogen content and low meat quality in pig skeletal muscle. PLoS Genet 2014; 10:e1004710. [PMID: 25340394 PMCID: PMC4207639 DOI: 10.1371/journal.pgen.1004710] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 08/26/2014] [Indexed: 11/19/2022] Open
Abstract
Glycolytic potential (GP) in skeletal muscle is economically important in the pig industry because of its effect on pork processing yield. We have previously mapped a major quantitative trait loci (QTL) for GP on chromosome 3 in a White Duroc × Erhualian F2 intercross. We herein performed a systems genetic analysis to identify the causal variant underlying the phenotype QTL (pQTL). We first conducted genome-wide association analyses in the F2 intercross and an F19 Sutai pig population. The QTL was then refined to an 180-kb interval based on the 2-LOD drop method. We then performed expression QTL (eQTL) mapping using muscle transcriptome data from 497 F2 animals. Within the QTL interval, only one gene (PHKG1) has a cis-eQTL that was colocolizated with pQTL peaked at the same SNP. The PHKG1 gene encodes a catalytic subunit of the phosphorylase kinase (PhK), which functions in the cascade activation of glycogen breakdown. Deep sequencing of PHKG1 revealed a point mutation (C>A) in a splice acceptor site of intron 9, resulting in a 32-bp deletion in the open reading frame and generating a premature stop codon. The aberrant transcript induces nonsense-mediated decay, leading to lower protein level and weaker enzymatic activity in affected animals. The mutation causes an increase of 43% in GP and a decrease of>20% in water-holding capacity of pork. These effects were consistent across the F2 and Sutai populations, as well as Duroc × (Landrace × Yorkshire) hybrid pigs. The unfavorable allele exists predominantly in Duroc-derived pigs. The findings provide new insights into understanding risk factors affecting glucose metabolism, and would greatly contribute to the genetic improvement of meat quality in Duroc related pigs. Glycogen storage diseases (GSD) are a group of inherited disorders characterized by storage of excess glycogen, which are mainly caused by the abnormality of a particular enzyme essential for releasing glucose from glycogen. GSD-like conditions have been described in a wide variety of species. Pigs are a valuable model for the study of human GSD. Moreover, pigs affected by GSD usually produce inferior pork with a lower ultimate pH (so-called “acid meat”) and less processing yield due to post-mortem degradation of the excess glycogen. So far, only one causal variant, PRKAG3 R225Q, has been identified for GSD in pigs. Here we reported a loss-of-function mutation in the PHKG1 gene that causes the deficiency of the glycogen breakdown, consequently leading to GSD and acid meat in Duroc-sired pigs. Eliminating the undesirable mutation from the breeding stock by a diagnostic DNA test will greatly reduce the incidence of GSD and significantly improve pork quality and productivity in the pig.
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Affiliation(s)
- Junwu Ma
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
- * E-mail: (JM); (LH)
| | - Jie Yang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Lisheng Zhou
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Jun Ren
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Xianxian Liu
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Hui Zhang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Bin Yang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Zhiyan Zhang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Huanban Ma
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Xianhua Xie
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Yuyun Xing
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Yuanmei Guo
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
| | - Lusheng Huang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, P.R. China
- * E-mail: (JM); (LH)
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Pfeiffer-Guglielmi B, Dombert B, Jablonka S, Hausherr V, van Thriel C, Schöbel N, Jansen RP. Axonal and dendritic localization of mRNAs for glycogen-metabolizing enzymes in cultured rodent neurons. BMC Neurosci 2014; 15:70. [PMID: 24898526 PMCID: PMC4079165 DOI: 10.1186/1471-2202-15-70] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 05/30/2014] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Localization of mRNAs encoding cytoskeletal or signaling proteins to neuronal processes is known to contribute to axon growth, synaptic differentiation and plasticity. In addition, a still increasing spectrum of mRNAs has been demonstrated to be localized under different conditions and developing stages thus reflecting a highly regulated mechanism and a role of mRNA localization in a broad range of cellular processes. RESULTS Applying fluorescence in-situ-hybridization with specific riboprobes on cultured neurons and nervous tissue sections, we investigated whether the mRNAs for two metabolic enzymes, namely glycogen synthase (GS) and glycogen phosphorylase (GP), the key enzymes of glycogen metabolism, may also be targeted to neuronal processes. If it were so, this might contribute to clarify the so far enigmatic role of neuronal glycogen. We found that the mRNAs for both enzymes are localized to axonal and dendritic processes in cultured lumbar spinal motoneurons, but not in cultured trigeminal neurons. In cultured cortical neurons which do not store glycogen but nevertheless express glycogen synthase, the GS mRNA is also subject to axonal and dendritic localization. In spinal motoneurons and trigeminal neurons in situ, however, the mRNAs could only be demonstrated in the neuronal somata but not in the nerves. CONCLUSIONS We could demonstrate that the mRNAs for major enzymes of neural energy metabolism can be localized to neuronal processes. The heterogeneous pattern of mRNA localization in different culture types and developmental stages stresses that mRNA localization is a versatile mechanism for the fine-tuning of cellular events. Our findings suggest that mRNA localization for enzymes of glycogen metabolism could allow adaptation to spatial and temporal energy demands in neuronal events like growth, repair and synaptic transmission.
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Affiliation(s)
- Brigitte Pfeiffer-Guglielmi
- Interfaculty Institute for Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, D-72076 Tübingen, Germany
| | - Benjamin Dombert
- Institute for Clinical Neurobiology, University of Würzburg, Würzburg, Germany
| | - Sibylle Jablonka
- Institute for Clinical Neurobiology, University of Würzburg, Würzburg, Germany
| | - Vanessa Hausherr
- Leibniz Research Center for Working Environment and Human Factors, Dortmund, Germany
| | - Christoph van Thriel
- Leibniz Research Center for Working Environment and Human Factors, Dortmund, Germany
| | - Nicole Schöbel
- Department of Cell Physiology, University of Bochum, Bochum, Germany
| | - Ralf-Peter Jansen
- Interfaculty Institute for Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, D-72076 Tübingen, Germany
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Saez I, Duran J, Sinadinos C, Beltran A, Yanes O, Tevy MF, Martínez-Pons C, Milán M, Guinovart JJ. Neurons have an active glycogen metabolism that contributes to tolerance to hypoxia. J Cereb Blood Flow Metab 2014; 34:945-55. [PMID: 24569689 PMCID: PMC4050236 DOI: 10.1038/jcbfm.2014.33] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 01/28/2014] [Accepted: 01/29/2014] [Indexed: 01/08/2023]
Abstract
Glycogen is present in the brain, where it has been found mainly in glial cells but not in neurons. Therefore, all physiologic roles of brain glycogen have been attributed exclusively to astrocytic glycogen. Working with primary cultured neurons, as well as with genetically modified mice and flies, here we report that-against general belief-neurons contain a low but measurable amount of glycogen. Moreover, we also show that these cells express the brain isoform of glycogen phosphorylase, allowing glycogen to be fully metabolized. Most importantly, we show an active neuronal glycogen metabolism that protects cultured neurons from hypoxia-induced death and flies from hypoxia-induced stupor. Our findings change the current view of the role of glycogen in the brain and reveal that endogenous neuronal glycogen metabolism participates in the neuronal tolerance to hypoxic stress.
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Affiliation(s)
- Isabel Saez
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
- Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain
| | - Jordi Duran
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | | | - Antoni Beltran
- Metabolomics Platform, CIBERDEM, Reus, Spain
- Center for Omic Sciences (COS), Universitat Rovira i Virgili, Reus, Spain
- Institut d'Investigació Biomédica Pere Virgili (IISPV), Reus, Spain
| | - Oscar Yanes
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
- Metabolomics Platform, CIBERDEM, Reus, Spain
- Center for Omic Sciences (COS), Universitat Rovira i Virgili, Reus, Spain
- Institut d'Investigació Biomédica Pere Virgili (IISPV), Reus, Spain
| | - María F Tevy
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
| | | | - Marco Milán
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Joan J Guinovart
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
- Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
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Liu D, Yang C. The nitrogen-regulated response regulator NrrA controls cyanophycin synthesis and glycogen catabolism in the cyanobacterium Synechocystis sp. PCC 6803. J Biol Chem 2014; 289:2055-71. [PMID: 24337581 PMCID: PMC3900954 DOI: 10.1074/jbc.m113.515270] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 12/05/2013] [Indexed: 11/06/2022] Open
Abstract
The cellular metabolism in cyanobacteria is extensively regulated in response to changes of environmental nitrogen availability. Multiple regulators are involved in this process, including a nitrogen-regulated response regulator NrrA. However, the regulatory role of NrrA in most cyanobacteria remains to be elucidated. In this study, we combined a comparative genomic reconstruction of NrrA regulons in 15 diverse cyanobacterial species with detailed experimental characterization of NrrA-mediated regulation in Synechocystis sp. PCC 6803. The reconstructed NrrA regulons in most species included the genes involved in glycogen catabolism, central carbon metabolism, amino acid biosynthesis, and protein degradation. A predicted NrrA-binding motif consisting of two direct repeats of TG(T/A)CA separated by an 8-bp A/T-rich spacer was verified by in vitro binding assays with purified NrrA protein. The predicted target genes of NrrA in Synechocystis sp. PCC 6803 were experimentally validated by comparing the transcript levels and enzyme activities between the wild-type and nrrA-inactivated mutant strains. The effect of NrrA deficiency on intracellular contents of arginine, cyanophycin, and glycogen was studied. Severe impairments in arginine synthesis and cyanophycin accumulation were observed in the nrrA-inactivated mutant. The nrrA inactivation also resulted in a significantly decreased rate of glycogen degradation. Our results indicate that by directly up-regulating expression of the genes involved in arginine synthesis, glycogen degradation, and glycolysis, NrrA controls cyanophycin accumulation and glycogen catabolism in Synechocystis sp. PCC 6803. It is suggested that NrrA plays a role in coordinating the synthesis and degradation of nitrogen and carbon reserves in cyanobacteria.
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Affiliation(s)
- Deng Liu
- From the Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chen Yang
- From the Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
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Badaruddin M, Holcombe LJ, Wilson RA, Wang ZY, Kershaw MJ, Talbot NJ. Glycogen metabolic genes are involved in trehalose-6-phosphate synthase-mediated regulation of pathogenicity by the rice blast fungus Magnaporthe oryzae. PLoS Pathog 2013; 9:e1003604. [PMID: 24098112 PMCID: PMC3789717 DOI: 10.1371/journal.ppat.1003604] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 07/24/2013] [Indexed: 01/05/2023] Open
Abstract
The filamentous fungus Magnaporthe oryzae is the causal agent of rice blast disease. Here we show that glycogen metabolic genes play an important role in plant infection by M. oryzae. Targeted deletion of AGL1 and GPH1, which encode amyloglucosidase and glycogen phosphorylase, respectively, prevented mobilisation of glycogen stores during appressorium development and caused a significant reduction in the ability of M. oryzae to cause rice blast disease. By contrast, targeted mutation of GSN1, which encodes glycogen synthase, significantly reduced the synthesis of intracellular glycogen, but had no effect on fungal pathogenicity. We found that loss of AGL1 and GPH1 led to a reduction in expression of TPS1 and TPS3, which encode components of the trehalose-6-phosphate synthase complex, that acts as a genetic switch in M. oryzae. Tps1 responds to glucose-6-phosphate levels and the balance of NADP/NADPH to regulate virulence-associated gene expression, in association with Nmr transcriptional inhibitors. We show that deletion of the NMR3 transcriptional inhibitor gene partially restores virulence to a Δagl1Δgph1 mutant, suggesting that glycogen metabolic genes are necessary for operation of the NADPH-dependent genetic switch in M. oryzae.
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Affiliation(s)
- Muhammad Badaruddin
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, Devon, United Kingdom
| | - Lucy J. Holcombe
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, Devon, United Kingdom
| | - Richard A. Wilson
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, Devon, United Kingdom
| | - Zheng-Yi Wang
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, Devon, United Kingdom
| | - Michael J. Kershaw
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, Devon, United Kingdom
| | - Nicholas J. Talbot
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, Devon, United Kingdom
- * E-mail:
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Iverson SV, Eriksson S, Xu J, Prigge JR, Talago EA, Meade TA, Meade ES, Capecchi MR, Arnér ES, Schmidt EE. A Txnrd1-dependent metabolic switch alters hepatic lipogenesis, glycogen storage, and detoxification. Free Radic Biol Med 2013; 63:369-80. [PMID: 23743293 PMCID: PMC3827783 DOI: 10.1016/j.freeradbiomed.2013.05.028] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 05/20/2013] [Indexed: 12/19/2022]
Abstract
Besides helping to maintain a reducing intracellular environment, the thioredoxin (Trx) system impacts bioenergetics and drug metabolism. We show that hepatocyte-specific disruption of Txnrd1, encoding Trx reductase-1 (TrxR1), causes a metabolic switch in which lipogenic genes are repressed and periportal hepatocytes become engorged with glycogen. These livers also overexpress machinery for biosynthesis of glutathione and conversion of glycogen into UDP-glucuronate; they stockpile glutathione-S-transferases and UDP-glucuronyl-transferases; and they overexpress xenobiotic exporters. This realigned metabolic profile suggested that the mutant hepatocytes might be preconditioned to more effectively detoxify certain xenobiotic challenges. Hepatocytes convert the pro-toxin acetaminophen (APAP, paracetamol) into cytotoxic N-acetyl-p-benzoquinone imine (NAPQI). APAP defenses include glucuronidation of APAP or glutathionylation of NAPQI, allowing removal by xenobiotic exporters. We found that NAPQI directly inactivates TrxR1, yet Txnrd1-null livers were resistant to APAP-induced hepatotoxicity. Txnrd1-null livers did not have more effective gene expression responses to APAP challenge; however, their constitutive metabolic state supported more robust GSH biosynthesis, glutathionylation, and glucuronidation systems. Following APAP challenge, this effectively sustained the GSH system and attenuated damage.
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Affiliation(s)
- Sonya V. Iverson
- Department of Immunology and Infectious Disease, Montana State University, Bozeman, MT, USA
| | - Sofi Eriksson
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Jianqiang Xu
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Justin R. Prigge
- Department of Immunology and Infectious Disease, Montana State University, Bozeman, MT, USA
| | - Emily A. Talago
- Department of Immunology and Infectious Disease, Montana State University, Bozeman, MT, USA
| | - Tesia A. Meade
- Department of Immunology and Infectious Disease, Montana State University, Bozeman, MT, USA
| | - Erin S. Meade
- Department of Immunology and Infectious Disease, Montana State University, Bozeman, MT, USA
| | | | - Elias S.J. Arnér
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Edward E. Schmidt
- Department of Immunology and Infectious Disease, Montana State University, Bozeman, MT, USA
- CRB, Washington State University, Pullman, WA, USA
- Correspondence: EE Schmidt, PO Box 173610, Bozeman, MT 59718, ph. (406) 994-6375,
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de Abreu LA, Calixto C, Waltero CF, Della Noce BP, Githaka NW, Seixas A, Parizi LF, Konnai S, Vaz IDSJ, Ohashi K, Logullo C. The conserved role of the AKT/GSK3 axis in cell survival and glycogen metabolism in Rhipicephalus (Boophilus) microplus embryo tick cell line BME26. Biochim Biophys Acta Gen Subj 2013; 1830:2574-82. [PMID: 23274741 DOI: 10.1016/j.bbagen.2012.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 11/23/2012] [Accepted: 12/15/2012] [Indexed: 02/07/2023]
Abstract
BACKGROUND Tick embryogenesis is a metabolically intensive process developed under tightly controlled conditions and whose components are poorly understood. METHODS In order to characterize the role of AKT (protein kinase B) in glycogen metabolism and cell viability, glycogen determination, identification and cloning of an AKT from Rhipicephalus microplus were carried out, in parallel with experiments using RNA interference (RNAi) and chemical inhibition. RESULTS A decrease in glycogen content was observed when AKT was chemically inhibited by 10-DEBC treatment, while GSK3 inhibition by alsterpaullone had an opposing effect. RmAKT ORF is 1584-bp long and encodes a polypeptide chain of 60.1 kDa. Phylogenetic and sequence analyses showed significant differences between vertebrate and tick AKTs. Either AKT or GSK3 knocked down cells showed a 70% reduction in target transcript levels, but decrease in AKT also reduced glycogen content, cell viability and altered cell membrane permeability. However, the GSK3 reduction promoted an increase in glycogen content. Additionally, either GSK3 inhibition or gene silencing had a protective effect on BME26 viability after exposure to ultraviolet radiation. R. microplus AKT and GSK3 were widely expressed during embryo development. Taken together, our data support an antagonistic role for AKT and GSK3, and strongly suggest that such a signaling axis is conserved in tick embryos, with AKT located upstream of GSK3. GENERAL SIGNIFICANCE The AKT/GSK3 axis is conserved in tick in a way that integrates glycogen metabolism and cell survival, and exhibits phylogenic differences that could be important for the development of novel control methods.
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Affiliation(s)
- Leonardo Araujo de Abreu
- LQFPP, CBB and Unidade de Experimentação Animal, RJ, UENF, Avenida Alberto Lamego, 2000, Horto, CEP 28013-602, Campos dos Goytacazes, RJ, Brazil
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Jung UJ, Park YB, Kim SR, Choi MS. Supplementation of persimmon leaf ameliorates hyperglycemia, dyslipidemia and hepatic fat accumulation in type 2 diabetic mice. PLoS One 2012; 7:e49030. [PMID: 23145054 PMCID: PMC3493507 DOI: 10.1371/journal.pone.0049030] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 10/03/2012] [Indexed: 01/31/2023] Open
Abstract
Persimmon Leaf (PL), commonly consumed as herbal tea and traditional medicines, contains a variety of compounds that exert antioxidant, α-amylase and α-glucosidase inhibitory activity. However, little is known about the in vivo effects and underlying mechanisms of PL on hyperglycemia, hyperlipidemia and hepatic steatosis in type 2 diabetes. Powered PL (5%, w/w) was supplemented with a normal diet to C57BL/KsJ-db/db mice for 5 weeks. PL decreased blood glucose, HOMA-IR, plasma triglyceride and total cholesterol levels, as well as liver weight, hepatic lipid droplets, triglycerides and cholesterol contents, while increasing plasma HDL-cholesterol and adiponectin levels. The anti-hyperglycemic effect was linked to decreased activity of gluconeogenic enzymes as well as increased glycogen content, glucokinase activity and its mRNA level in the liver. PL also led to a decrease in lipogenic transcriptional factor PPARγ as well as gene expression and activity of enzymes involved in lipogenesis, with a simultaneous increase in fecal lipids, which are seemingly attributable to the improved hyperlipidemia and hepatic steatosis and decreased hepatic fatty acid oxidation. Furthermore, PL ameliorated plasma and hepatic oxidative stress. Supplementation with PL may be an effective dietary strategy to improve type 2 diabetes accompanied by dyslipidemia and hepatic steatosis by partly modulating the activity or gene expression of enzymes related to antioxidant, glucose and lipid homeostasis.
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Affiliation(s)
- Un Ju Jung
- Department of Food Science and Nutrition, Kyungpook National University, Daegu, Republic of Korea
| | - Yong Bok Park
- School of Life Sciences and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
| | - Sang Ryong Kim
- School of Life Sciences and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
- Brain Science and Engineering Institute, Kyungpook National University, Daegu, Republic of Korea
| | - Myung-Sook Choi
- Department of Food Science and Nutrition, Kyungpook National University, Daegu, Republic of Korea
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Abstract
BACKGROUND Genomic imprinting refers to parent-of-origin dependent gene expression caused by differential DNA methylation of the paternally and maternally derived alleles. Imprinting is increasingly recognized as an important source of variation in complex traits, however, its role in explaining variation in muscle and physiological traits, especially those of commercial value, is largely unknown compared with genetic effects. RESULTS We investigated both genetic and genomic imprinting effects on key muscle traits in mice from the Berlin Muscle Mouse population, a key model system to study muscle traits. Using a genome scan, we first identified loci with either imprinting or genetic effects on phenotypic variation. Next, we established the proportion of phenotypic variation explained by additive, dominance and imprinted QTL and characterized the patterns of effects. In total, we identified nine QTL, two of which show large imprinting effects on glycogen content and potential, and body weight. Surprisingly, all imprinting patterns were of the bipolar type, in which the two heterozygotes are different from each other but the homozygotes are not. Most QTL had pleiotropic effects and explained up to 40% of phenotypic variance, with individual imprinted loci accounting for 4-5% of variation alone. CONCLUSION Surprisingly, variation in glycogen content and potential was only modulated by imprinting effects. Further, in contrast to general assumptions, our results show that genomic imprinting can impact physiological traits measured at adult stages and that the expression does not have to follow the patterns of paternal or maternal expression commonly ascribed to imprinting effects.
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Affiliation(s)
- Stefan Kärst
- Department for Crop and Animal Sciences, Humboldt-University Berlin, Berlin, Germany
| | - Ali R Vahdati
- Computational and Evolutionary Biology, Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK
| | - Gudrun A Brockmann
- Department for Crop and Animal Sciences, Humboldt-University Berlin, Berlin, Germany
| | - Reinmar Hager
- Department for Crop and Animal Sciences, Humboldt-University Berlin, Berlin, Germany
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Abstract
Danon disease is a rare X-linked dominant lysosomal disease due to the primary deficiency of lysosome-associated membrane protein 2 (LAMP2) gene. Cardiomyopathy, skeletal myopathy and mental retardation are the typical triad of Danon disease. More than 60 LAMP2 mutations have been reported. The molecular mechanism is defects in LAMP2 protein (due to LAMP2 mutation) which causes insidious glycogen accumulation in cardiac muscle cells and resulting in cardiac hypertrophy and electrophysiological abnormalities. However, there are significant differences between the male and female Danon disease patients with regard to clinical features and cardiac manifestations. The clinical symptoms are variable, from asymptomatic to sudden cardiac death. Wolff-Parkinson-White syndrome is more common in male than female patients. Hypertrophic cardiomyopathy is predominant in male patients, whereas the similar prevalence of hypertrophic and dilated cardiomyopathy in female patients. Male patients are diagnosed usually at teenage, whereas the diagnosis and events occurred approximately 15 years later in female than male patients. Heart transplantation is the reliable treatment once the occurrence of heart failure and should be considered as early as possible due to its rapid progression.
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Affiliation(s)
- Zhongwei Cheng
- Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
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30
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Qin QL, Li Y, Zhang YJ, Zhou ZM, Zhang WX, Chen XL, Zhang XY, Zhou BC, Wang L, Zhang YZ. Comparative genomics reveals a deep-sea sediment-adapted life style of Pseudoalteromonas sp. SM9913. ISME J 2011; 5:274-84. [PMID: 20703316 PMCID: PMC3105692 DOI: 10.1038/ismej.2010.103] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 05/21/2010] [Accepted: 06/13/2010] [Indexed: 11/09/2022]
Abstract
Deep-sea sediment is one of the most important microbial-driven ecosystems, yet it is not well characterized. Genome sequence analyses of deep-sea sedimentary bacteria would shed light on the understanding of this ecosystem. In this study, the complete genome of deep-sea sedimentary bacterium Pseudoalteromonas sp. SM9913 (SM9913) is described and compared with that of the closely related Antarctic surface sea-water ecotype Pseudoalteromonas haloplanktis TAC125 (TAC125). SM9913 has fewer dioxygenase genes than TAC125, indicating a possible sensitivity to reactive oxygen species. Accordingly, experimental results showed that SM9913 was less tolerant of H(2)O(2) than TAC125. SM9913 has gene clusters related to both polar and lateral flagella biosynthesis. Lateral flagella, which are usually present in deep-sea bacteria and absent in the related surface bacteria, are important for the survival of SM9913 in deep-sea environments. With these two flagellar systems, SM9913 can swim in sea water and swarm on the sediment particle surface, favoring the acquisition of nutrients from particulate organic matter and reflecting the particle-associated alternative lifestyle of SM9913 in the deep sea. A total of 12 genomic islands were identified in the genome of SM9913 that may confer specific features unique to SM9913 and absent from TAC125, such as drug and heavy metal resistance. Many signal transduction genes and a glycogen production operon were also present in the SM9913 genome, which may help SM9913 respond to food pulses and store carbon and energy in a deep-sea environment.
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Affiliation(s)
- Qi-Long Qin
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, People's Republic of China
| | - Yang Li
- State Key Lab of Microbial Technology, TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Yan-Jiao Zhang
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, People's Republic of China
| | - Zhe-Min Zhou
- State Key Lab of Microbial Technology, TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Wei-Xin Zhang
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, People's Republic of China
| | - Xiu-Lan Chen
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, People's Republic of China
| | - Xi-Ying Zhang
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, People's Republic of China
| | - Bai-Cheng Zhou
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, People's Republic of China
| | - Lei Wang
- State Key Lab of Microbial Technology, TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Yu-Zhong Zhang
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, People's Republic of China
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31
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Jiang S, Heller B, Tagliabracci VS, Zhai L, Irimia JM, DePaoli-Roach AA, Wells CD, Skurat AV, Roach PJ. Starch binding domain-containing protein 1/genethonin 1 is a novel participant in glycogen metabolism. J Biol Chem 2010; 285:34960-71. [PMID: 20810658 PMCID: PMC2966110 DOI: 10.1074/jbc.m110.150839] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 08/30/2010] [Indexed: 11/06/2022] Open
Abstract
Stbd1 is a protein of previously unknown function that is most prevalent in liver and muscle, the major sites for storage of the energy reserve glycogen. The protein is predicted to contain a hydrophobic N terminus and a C-terminal CBM20 glycan binding domain. Here, we show that Stbd1 binds to glycogen in vitro and that endogenous Stbd1 locates to perinuclear compartments in cultured mouse FL83B or Rat1 cells. When overexpressed in COSM9 cells, Stbd1 concentrated at enlarged perinuclear structures, co-localized with glycogen, the late endosomal/lysosomal marker LAMP1 and the autophagy protein GABARAPL1. Mutant Stbd1 lacking the N-terminal hydrophobic segment had a diffuse distribution throughout the cell. Point mutations in the CBM20 domain did not change the perinuclear localization of Stbd1, but glycogen was no longer concentrated in this compartment. Stable overexpression of glycogen synthase in Rat1WT4 cells resulted in accumulation of glycogen as massive perinuclear deposits, where a large fraction of the detectable Stbd1 co-localized. Starvation of Rat1WT4 cells for glucose resulted in dissipation of the massive glycogen stores into numerous and much smaller glycogen deposits that retained Stbd1. In vitro, in cells, and in animal models, Stbd1 consistently tracked with glycogen. We conclude that Stbd1 is involved in glycogen metabolism by binding to glycogen and anchoring it to membranes, thereby affecting its cellular localization and its intracellular trafficking to lysosomes.
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Affiliation(s)
- Sixin Jiang
- From the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Brigitte Heller
- From the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Vincent S. Tagliabracci
- From the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Lanmin Zhai
- From the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Jose M. Irimia
- From the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Anna A. DePaoli-Roach
- From the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Clark D. Wells
- From the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Alexander V. Skurat
- From the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Peter J. Roach
- From the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202
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32
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Fritsche L, Hoene M, Lehmann R, Ellingsgaard H, Hennige AM, Pohl AK, Häring HU, Schleicher ED, Weigert C. IL-6 deficiency in mice neither impairs induction of metabolic genes in the liver nor affects blood glucose levels during fasting and moderately intense exercise. Diabetologia 2010; 53:1732-42. [PMID: 20411234 DOI: 10.1007/s00125-010-1754-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 03/02/2010] [Indexed: 02/07/2023]
Abstract
AIMS/HYPOTHESIS Fasting and exercise are strong physiological stimuli for hepatic glucose production. IL-6 has been implicated in the regulation of gluconeogenic genes, but the results are contradictory and the relevance of IL-6 for fasting- and exercise-induced hepatic glucose production is not clear. METHODS Investigations were performed in rat hepatoma cells, and on C57Bl6 and Il6(-/-) mice under the following conditions: IL-6 stimulation/injection, non-exhaustive exercise (60 min run on a treadmill) and fasting for 16 h. Metabolite analysis, quantitative real-time PCR and immunoblotting were performed. RESULTS IL-6 stimulation of rat hepatoma cells led to higher glucose production. Injection of IL-6 in mice slightly increased hepatic Pepck (also known as Pck1) expression. Fasting of Il6(-/-) mice for 16 h did not alter glucose production compared with wild-type mice, since plasma glucose concentrations were similar and upregulation of phosphoenolpyruvate carboxykinase (PEPCK) and Pgc-1alpha (also known as Ppargc1a) expression was comparable. In the non-fasting state, Il6(-/-) mice showed a mild metabolic alteration including higher plasma glucose and insulin levels, lower NEFA concentrations and slightly increased hepatic PEPCK content. Moderately intense exercise resulted in elevated IL-6 plasma levels in wild-type mice. Despite that, plasma glucose, insulin, NEFA levels and hepatic glycogen content were not different in Il6(-/-) mice immediately after running, while expression of hepatic G6pc, Pgc-1alpha, Irs2 and Igfbp1 mRNA was similarly increased. CONCLUSIONS/INTERPRETATION These data suggest that in mice IL-6 is not essential for physiologically increased glucose production during fasting or non-exhaustive exercise.
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Affiliation(s)
- L Fritsche
- Department of Internal Medicine, Division of Pathobiochemistry and Clinical Chemistry, University of Tuebingen, Otfried-Mueller-Strasse 10, 72076 Tuebingen, Germany
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Irimia JM, Meyer CM, Peper CL, Zhai L, Bock CB, Previs SF, McGuinness OP, DePaoli-Roach A, Roach PJ. Impaired glucose tolerance and predisposition to the fasted state in liver glycogen synthase knock-out mice. J Biol Chem 2010; 285:12851-61. [PMID: 20178984 PMCID: PMC2857087 DOI: 10.1074/jbc.m110.106534] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 02/18/2010] [Indexed: 12/17/2022] Open
Abstract
Conversion to glycogen is a major fate of ingested glucose in the body. A rate-limiting enzyme in the synthesis of glycogen is glycogen synthase encoded by two genes, GYS1, expressed in muscle and other tissues, and GYS2, primarily expressed in liver (liver glycogen synthase). Defects in GYS2 cause the inherited monogenic disease glycogen storage disease 0. We have generated mice with a liver-specific disruption of the Gys2 gene (liver glycogen synthase knock-out (LGSKO) mice), using Lox-P/Cre technology. Conditional mice carrying floxed Gys2 were crossed with mice expressing Cre recombinase under the albumin promoter. The resulting LGSKO mice are viable, develop liver glycogen synthase deficiency, and have a 95% reduction in fed liver glycogen content. They have mild hypoglycemia but dispose glucose less well in a glucose tolerance test. Fed, LGSKO mice also have a reduced capacity for exhaustive exercise compared with mice carrying floxed alleles, but the difference disappears after an overnight fast. Upon fasting, LGSKO mice reach within 4 h decreased blood glucose levels attained by control floxed mice only after 24 h of food deprivation. The LGSKO mice maintain this low blood glucose for at least 24 h. Basal gluconeogenesis is increased in LGSKO mice, and insulin suppression of endogenous glucose production is impaired as assessed by euglycemic-hyperinsulinemic clamp. This observation correlates with an increase in the liver gluconeogenic enzyme phosphoenolpyruvate carboxykinase expression and activity. This mouse model mimics the pathophysiology of glycogen storage disease 0 patients and highlights the importance of liver glycogen stores in whole body glucose homeostasis.
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Affiliation(s)
- Jose M. Irimia
- From the
Department of Biochemistry and Molecular Biology, Center for Diabetes Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Catalina M. Meyer
- From the
Department of Biochemistry and Molecular Biology, Center for Diabetes Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Caron L. Peper
- From the
Department of Biochemistry and Molecular Biology, Center for Diabetes Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Lanmin Zhai
- From the
Department of Biochemistry and Molecular Biology, Center for Diabetes Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Cheryl B. Bock
- the
Duke University Medical Center, Durham, North Carolina 27710
| | - Stephen F. Previs
- the
Department of Nutrition, Case Western Reserve University, Cleveland, Ohio 44106, and
| | - Owen P. McGuinness
- the
Metabolic Patho-Physiology Core of the Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Anna DePaoli-Roach
- From the
Department of Biochemistry and Molecular Biology, Center for Diabetes Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Peter J. Roach
- From the
Department of Biochemistry and Molecular Biology, Center for Diabetes Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
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Zong H, Bastie CC, Xu J, Fassler R, Campbell KP, Kurland IJ, Pessin JE. Insulin resistance in striated muscle-specific integrin receptor beta1-deficient mice. J Biol Chem 2009; 284:4679-88. [PMID: 19064993 PMCID: PMC2640962 DOI: 10.1074/jbc.m807408200] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 12/01/2008] [Indexed: 01/19/2023] Open
Abstract
Integrin receptor plays key roles in mediating both inside-out and outside-in signaling between cells and the extracellular matrix. We have observed that the tissue-specific loss of the integrin beta1 subunit in striated muscle results in a near complete loss of integrin beta1 subunit protein expression concomitant with a loss of talin and to a lesser extent, a reduction in F-actin content. Muscle-specific integrin beta1-deficient mice had no significant difference in food intake, weight gain, fasting glucose, and insulin levels with their littermate controls. However, dynamic analysis of glucose homeostasis using euglycemichyperinsulinemic clamps demonstrated a 44 and 48% reduction of insulin-stimulated glucose infusion rate and glucose clearance, respectively. The whole body insulin resistance resulted from a specific inhibition of skeletal muscle glucose uptake and glycogen synthesis without any significant effect on the insulin suppression of hepatic glucose output or insulin-stimulated glucose uptake in adipose tissue. The reduction in skeletal muscle insulin responsiveness occurred without any change in GLUT4 protein expression levels but was associated with an impairment of the insulin-stimulated protein kinase B/Akt serine 473 phosphorylation but not threonine 308. The inhibition of insulin-stimulated serine 473 phosphorylation occurred concomitantly with a decrease in integrin-linked kinase expression but with no change in the mTOR.Rictor.LST8 complex (mTORC2). These data demonstrate an in vivo crucial role of integrin beta1 signaling events in mediating cross-talk to that of insulin action.
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Affiliation(s)
- Haihong Zong
- Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Gomes FR, Rezende EL, Malisch JL, Lee SK, Rivas DA, Kelly SA, Lytle C, Yaspelkis BB, Garland T. Glycogen storage and muscle glucose transporters (GLUT-4) of mice selectively bred for high voluntary wheel running. J Exp Biol 2009; 212:238-48. [PMID: 19112143 PMCID: PMC2721000 DOI: 10.1242/jeb.025296] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2008] [Indexed: 01/09/2023]
Abstract
To examine the evolution of endurance-exercise behaviour, we have selectively bred four replicate lines of laboratory mice (Mus domesticus) for high voluntary wheel running (;high runner' or HR lines), while also maintaining four non-selected control (C) lines. By generation 16, HR mice ran approximately 2.7-fold more than C mice, mainly by running faster (especially in females), a differential maintained through subsequent generations, suggesting an evolutionary limit of unknown origin. We hypothesized that HR mice would have higher glycogen levels before nightly running, show greater depletion of those depots during their more intense wheel running, and have increased glycogen synthase activity and GLUT-4 protein in skeletal muscle. We sampled females from generation 35 at three times (photophase 07:00 h-19:00 h) during days 5-6 of wheel access, as in the routine selection protocol: Group 1, day 5, 16:00 h-17:30 h, wheels blocked from 13:00 h; Group 2, day 6, 02:00 h-03:30 h (immediately after peak running); and Group 3, day 6, 07:00 h-08:30 h. An additional Group 4, sampled 16:00 h-17:30 h, never had wheels. HR individuals with the mini-muscle phenotype (50% reduced hindlimb muscle mass) were distinguished for statistical analyses comparing C, HR normal, and HR mini. HR mini ran more than HR normal, and at higher speeds, which might explain why they have been favored by the selective-breeding protocol. Plasma glucose was higher in Group 1 than in Group 4, indicating a training effect (phenotypic plasticity). Without wheels, no differences in gastrocnemius GLUT-4 were observed. After 5 days with wheels, all mice showed elevated GLUT-4, but HR normal and mini were 2.5-fold higher than C. At all times and irrespective of wheel access, HR mini showed approximately three-fold higher [glycogen] in gastrocnemius and altered glycogen synthase activity. HR mini also showed elevated glycogen in soleus when sampled during peak running. All mice showed some glycogen depletion during nightly wheel running, in muscles and/or liver, but the magnitude of this depletion was not large and hence does not seem to be limiting to the evolution of even-higher wheel running.
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Affiliation(s)
- Fernando R Gomes
- Department of Biology, University of California, Riverside, CA 92521, USA
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Qiu JJ, Wei M, Zhang WM, Shi HP. [Clinical and molecular genetic study on two patients of the juvenile form of Pompe disease in China]. Zhonghua Er Ke Za Zhi 2007; 45:760-764. [PMID: 18211760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
OBJECTIVE Glycogen-storage disease type II (GSD II, Pompe's disease) is an autosomal recessive disorder caused by a functional deficiency of acid alpha-glucosidase (GAA) that leads to glycogen accumulation within lysosomes in most tissues. The GAA gene is located to human chromosome 17q25 and contains 20 exons, 19 of which are coding. Clinically, patients with the severe infantile form of GSD II have muscle weakness and cardiomyopathy eventually leading to death before the age of two years. Patients with the juvenile or the adult form of GSD II present with myopathy with a slow progression over several years or decades. A broad genetic heterogeneity has been described in GSD II in Europe, South Africa, USA, Japan and Korea, however, the investigation has not been performed in the patients from the mainland of China. In this study, clinical analysis and mutation detection were done on Chinese patients. METHODS Two unrelated juvenile patients with late onset GSD II (one boy, 3 years old and one girl, 9 years old) were included in the study with the informed consents. The diagnosis was confirmed by alpha-glucosidase determination in cultured fibroblasts. In addition, their clinical presentation, laboratory findings, electrophysiologic studies and muscle biopsy findings were analyzed in detail. Genomic DNA samples were extracted from fibroblasts of the probands, from peripheral blood of their parents and 50 unrelated, normal individuals. All the coding 19 exons and exon-intron boundaries of GAA were detected in the proband by polymerase chain reaction (PCR) and direct sequencing. RESULTS One patient presented decrease of muscle strength, limb-girdle hypotonia, the other patient presented reduced muscle volumes and respiratory problems. Both had increased CPK value, myopathic pattern on EMG; vacuoles on muscle biopsy, and deficiency of 1, 4-alpha-glucosidase activity. After 1 year follow up, the girl died after pneumonia at 10 years of age. One patient was found to be compound heretozygote for the novel mutation Arg702His, and the previously reported mutation Pro266Ser, which was reported in Korean population, with the late-onset phenotype. Two novel missense mutations Thr711Arg, Val723Met were found on the other patients. CONCLUSIONS Three mutations identified in the patient were new missense mutations causing late onset GSD II, which had not been reported elsewhere before.
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Affiliation(s)
- Jia-Jing Qiu
- Department of Pediatrics, PUMC Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
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Wilson RJ, Gusba JE, Robinson DL, Graham TE. Glycogenin protein and mRNA expression in response to changing glycogen concentration in exercise and recovery. Am J Physiol Endocrinol Metab 2007; 292:E1815-22. [PMID: 17311895 DOI: 10.1152/ajpendo.00598.2006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Glycogenin (GN-1) is essential for the formation of a glycogen granule; however, rarely has it been studied when glycogen concentration changes in exercise and recovery. It is unclear whether GN-1 is degraded or is liberated and exists as apoprotein (apo)-GN-1 (unglycosylated). To examine this, we measured GN-1 protein and mRNA level at rest, at exhaustion (EXH), and during 5 h of recovery in which the rate of glycogen restoration was influenced by carbohydrate (CHO) provision. Ten males cycled (65% VO2 max) to volitional EXH (117.8 +/- 4.2 min) on two separate occasions. Subjects were administered carbohydrate (CHO; 1 g.kg(-1).h(-1) Gatorlode) or water [placebo (PL)] during 5 h of recovery. Muscle biopsies were taken at rest, at EXH, and following 30, 60, 120, and 300 min of recovery. At EXH, total glycogen concentration was reduced (P < 0.05). However, GN-1 protein and mRNA content did not change. By 5 h of recovery, glycogen was resynthesized to approximately 60% of rest in the CHO trial and remained unchanged in the PL trial. GN-1 protein and mRNA level did not increase during recovery in either trial. We observed modest amounts of apo-GN-1 at EXH, suggesting complete degradation of some granules. These data suggest that GN-1 is conserved, possibly as very small, or nascent, granules when glycogen concentration is low. This would provide the ability to rapidly restore glycogen during early recovery.
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Affiliation(s)
- Rhonda J Wilson
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1.
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Abstract
G-protein-coupled receptor (GPCR) kinases (GRKs) are serine/threonine kinases that desensitize agonist-occupied classical GPCRs. Although the insulin receptor (IR) is a tyrosine kinase receptor, the IR also couples to G-proteins and utilizes G-protein signaling components. The present study was designed to test the hypothesis that GRK2 negatively regulates IR signaling. FL83B cells, derived from mouse liver, were treated with insulin and membrane translocation of GRK2 was determined using immunofluoresecence and Western blotting. Insulin caused an increase in the translocation of GRK-2 from cytosol to the plasma membrane. To determine the role of GRK2 in IR signaling, GRK2 was selectively down-regulated ( approximately by 90%) in FL83B cells using a small interfering RNA technique. Basal as well as insulin-induced glycogen synthesis (measured by d-[U-(14)C]glucose incorporation) was increased in GRK2-deficient cells compared with control cells. Similarly, GRK2 deficiency increased the basal and insulin-stimulated phosphorylation of Ser(21) in glycogen synthase kinase-3alpha. Insulin-induced tyrosine phosphorylation of the IR was similar in control and GRK2-deficient cells. Basal and insulin-stimulated phosphorylation of Tyr(612) in insulin receptor subunit 1 was significantly increased while phosphorylation of Ser(307) was decreased in GRK2-deficient FL83B cells compared with control cells. Chronic insulin treatment (24 h) in control cells caused an increase in GRK2 (56%) and a decrease in IR (50%) expression associated with the absence of an increase in glycogen synthesis, suggesting impairment of IR function. However, chronic insulin treatment (24 h) did not decrease IR expression or impair IR effects on glycogen synthesis in GRK2-deficient cells. We conclude that (i) GRK2 negatively regulates basal and insulin-stimulated glycogen synthesis via a post-IR signaling mechanism, and (ii) GRK2 may contribute to reduced IR expression and function during chronic insulin exposure.
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Affiliation(s)
- Gulnar Shahid
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, 4800 Calhoun, Houston, TX 77204, USA
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Suzuki E, Umeda K, Nihei S, Moriya K, Ohkawa H, Fujiwara S, Tsuzuki M, Nakamura Y. Role of the GlgX protein in glycogen metabolism of the cyanobacterium, Synechococcus elongatus PCC 7942. Biochim Biophys Acta Gen Subj 2007; 1770:763-73. [PMID: 17321685 DOI: 10.1016/j.bbagen.2007.01.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2006] [Revised: 12/11/2006] [Accepted: 01/09/2007] [Indexed: 10/23/2022]
Abstract
The putative glgX gene encoding isoamylase-type debranching enzyme was isolated from the cyanobacterium, Synechococcus elongatus PCC 7942. The deduced amino acid sequence indicated that the residues essential to the catalytic activity and substrate binding in bacterial and plant isoamylases and GlgX proteins were all conserved in the GlgX protein of S. elongatus PCC 7942. The role of GlgX in the cyanobacterium was examined by insertional inactivation of the gene. Disruption of the glgX gene resulted in the enhanced fluctuation of glycogen content in the cells during light-dark cycles of the culture, although the effect was marginal. The glycogen of the glgX mutant was enriched with very short chains with degree of polymerization 2 to 4. When the mutant was transformed with putative glgX genes of Synechocystis sp. PCC 6803, the short chains were decreased as compared to the parental mutant strain. The result indicated that GlgX protein contributes to form the branching pattern of polysaccharide in S. elongatus PCC 7942.
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Affiliation(s)
- Eiji Suzuki
- Department of Biological Production, Faculty of Bioresource Sciences, Akita Prefectural University, Akita, 010-0195, Japan.
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Wang W, Parker GE, Skurat AV, Raben N, DePaoli-Roach AA, Roach PJ. Relationship between glycogen accumulation and the laforin dual specificity phosphatase. Biochem Biophys Res Commun 2006; 350:588-92. [PMID: 17022935 PMCID: PMC1850102 DOI: 10.1016/j.bbrc.2006.09.091] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Accepted: 09/19/2006] [Indexed: 11/23/2022]
Abstract
Laforin, encoded by the EPM2A gene, is a dual specificity protein phosphatase that has a functional glycogen-binding domain. Mutations in the EPM2A gene account for around half of the cases of Lafora disease, an autosomal recessive neurodegenerative disorder, characterized by progressive myoclonus epilepsy. The hallmark of the disease is the presence of Lafora bodies, which contain polyglucosan, a poorly branched form of glycogen, in neurons and other tissues. We examined the level of laforin protein in several mouse models in which muscle glycogen accumulation has been altered genetically. Mice with elevated muscle glycogen have increased laforin as judged by Western analysis. Mice completely lacking muscle glycogen or with 10% normal muscle glycogen had reduced laforin. Mice defective in the GAA gene encoding lysosomal alpha-glucosidase (acid maltase) overaccumulate glycogen in the lysosome but did not have elevated laforin. We propose, therefore, that laforin senses cytosolic glycogen accumulation which in turn determines the level of laforin protein.
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Affiliation(s)
| | - Gretchen E. Parker
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202–5122 and Indiana University Center for Diabetes Research
| | - Alexander V. Skurat
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202–5122 and Indiana University Center for Diabetes Research
| | - Nina Raben
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda
| | - Anna A. DePaoli-Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202–5122 and Indiana University Center for Diabetes Research
| | - Peter J. Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202–5122 and Indiana University Center for Diabetes Research
- ¶Correspondence to: Peter J. Roach, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5122, Phone 317 274-1582, FAX 317 274-4686, E-mail
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41
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Cheng A, Zhang M, Crosson SM, Bao ZQ, Saltiel AR. Regulation of the mouse protein targeting to glycogen (PTG) promoter by the FoxA2 forkhead protein and by 3',5'-cyclic adenosine 5'-monophosphate in H4IIE hepatoma cells. Endocrinology 2006; 147:3606-12. [PMID: 16627590 DOI: 10.1210/en.2005-1513] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The scaffolding protein, protein targeting to glycogen (PTG), orchestrates the signaling of several metabolic enzymes involved in glycogen synthesis. However, little is known concerning the regulation of PTG itself. In this study, we have cloned and characterized the mouse promoter of PTG. We identified multiple FoxA2 binding sites within this region. FoxA2 is a member of the forkhead family of transcription factors that has recently been implicated in the cAMP-dependent regulation of several genes involved in liver metabolism. Using luciferase reporter constructs, we demonstrate that FoxA2 transactivates the PTG promoter in H4IIE hepatoma cells. Nuclear extracts prepared from mouse liver and H4IIE cells were able to bind a FoxA2-specific probe derived within the PTG promoter region. Chromatin immunoprecipitation experiments further demonstrate that FoxA2 binds to the PTG promoter in vivo. Finally, we show that treatment with cAMP analogs activates the PTG promoter and significantly increases PTG levels in H4IIE cells. Our results provide a framework to investigate how additional transcription factors may regulate PTG expression in other cell types.
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Affiliation(s)
- Alan Cheng
- Department of Internal Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, 48109, USA
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42
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Jeong JW, Kwak I, Lee KY, White LD, Wang XP, Brunicardi FC, O'Malley BW, DeMayo FJ. The Genomic Analysis of the Impact of Steroid Receptor Coactivators Ablation on Hepatic Metabolism. Mol Endocrinol 2006; 20:1138-52. [PMID: 16423883 DOI: 10.1210/me.2005-0407] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Members of the steroid receptor coactivator (SRC) family, which include SRC-1 (NcoA-1/p160), SRC-2(TIF2/GRIP1/NcoA-2) and SRC-3(pCIP/RAC3/ACTR/pCIP/ AIB1/TRAM1), are critical mediators of steroid receptor action. Gene ablation studies previously identified SRC-1 and SRC-2 as being involved in the control of energy homeostasis. A more precise identification of the molecular pathways regulated by these coactivators is crucial for understanding the role of steroid receptor coactivators in the control of energy homeostasis and obesity. A genomic approach using microarray analysis was employed to identify the subsets of genes that are altered in the livers of SRC-1-/-, SRC-2-/-, and SRC-3-/- mice. Microarray analysis demonstrates that gene expression changes are specific and nonoverlapping for each SRC member in the liver. The overall pattern of altered gene expressions in the SRC-1-/- mice was up-regulation, whereas SRC-2-/- mice showed an overall down-regulation. Several key regulatory enzymes of energy metabolism were significantly altered in the liver of SRC-2-/- mice, which are consistent with the prior observation that SRC-2-/- mice have increased energy expenditure. This study demonstrates that the molecular targets of SRC-2 regulation in the murine liver stimulate fatty acid degradation and glycolytic pathway, whereas fatty acid, cholesterol, and steroid biosynthetic pathways are down-regulated.
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Affiliation(s)
- Jae-Wook Jeong
- Department of Molecular and Cellular Biology, Microarray Core Facility, Baylor College of Medicine, Houston, Texas 77030, USA
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43
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Polekhina G, Gupta A, van Denderen BJW, Feil SC, Kemp BE, Stapleton D, Parker MW. Structural Basis for Glycogen Recognition by AMP-Activated Protein Kinase. Structure 2005; 13:1453-62. [PMID: 16216577 DOI: 10.1016/j.str.2005.07.008] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2005] [Revised: 07/07/2005] [Accepted: 07/09/2005] [Indexed: 10/25/2022]
Abstract
AMP-activated protein kinase (AMPK) coordinates cellular metabolism in response to energy demand as well as to a variety of stimuli. The AMPK beta subunit acts as a scaffold for the alpha catalytic and gamma regulatory subunits and targets the AMPK heterotrimer to glycogen. We have determined the structure of the AMPK beta glycogen binding domain in complex with beta-cyclodextrin. The structure reveals a carbohydrate binding pocket that consolidates all known aspects of carbohydrate binding observed in starch binding domains into one site, with extensive contact between several residues and five glucose units. beta-cyclodextrin is held in a pincer-like grasp with two tryptophan residues cradling two beta-cyclodextrin glucose units and a leucine residue piercing the beta-cyclodextrin ring. Mutation of key beta-cyclodextrin binding residues either partially or completely prevents the glycogen binding domain from binding glycogen. Modeling suggests that this binding pocket enables AMPK to interact with glycogen anywhere across the carbohydrate's helical surface.
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Affiliation(s)
- Galina Polekhina
- St. Vincent's Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065, Australia
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44
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Shearer J, Graham TE, Battram DS, Robinson DL, Richter EA, Wilson RJ, Bakovic M. Glycogenin activity and mRNA expression in response to volitional exhaustion in human skeletal muscle. J Appl Physiol (1985) 2005; 99:957-62. [PMID: 15860684 DOI: 10.1152/japplphysiol.00275.2005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glycogenolysis results in the selective catabolism of individual glycogen granules by glycogen phosphorylase. However, once the carbohydrate portion of the granule is metabolized, the fate of glycogenin, the protein primer of granule formation, is not known. To examine this, male subjects ( n = 6) exercised to volitional exhaustion (Exh) on a cycle ergometer at 75% maximal O2uptake. Muscle biopsies were obtained at rest, 30 min, and Exh (99 ± 10 min). At rest, total glycogen concentration was 497 ± 41 and declined to 378 ± 51 mmol glucosyl units/kg dry wt following 30 min of exercise ( P < 0.05). There were no significant changes in proglycogen, macroglycogen, glycogenin activity, or mRNA in this period ( P ≥ 0.05). Exh resulted in decreases in total glycogen, proglycogen, and macroglycogen as well as glycogenin activity ( P < 0.05). These decrements were associated with a 1.9 ± 0.4-fold increase in glycogenin mRNA over resting values ( P < 0.05). Glycogenolysis in the initial exercise period (0–30 min) was not adequate to induce changes in glycogenin; however, later in exercise when concentration and granule number decreased further, decrements in glycogenin activity and increases in glycogenin mRNA were demonstrated. Results show that glycogenin becomes inactivated with glycogen catabolism and that this event coincides with an increase in glycogenin gene expression as exercise and glycogenolysis progress.
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Affiliation(s)
- Jane Shearer
- Department of Human Biology and Nutritional Sciences, University of Guelph, Ontario, Canada.
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45
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Kania G, Blyszczuk P, Jochheim A, Ott M, Wobus AM. Generation of glycogen- and albumin-producing hepatocyte-like cells from embryonic stem cells. Biol Chem 2005; 385:943-53. [PMID: 15551869 DOI: 10.1515/bc.2004.123] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We present a novel two-step protocol for the differentiation of embryonic stem (ES) cells into the hepatic lineage. Differentiated hepatocyte-like cells express genes and proteins characteristic for endodermal and hepatic cells and acquire a functional hepatic phenotype as demonstrated by albumin secretion and glycogen storage. During differentiation, alpha-fetoprotein, albumin, transthyretin, alpha-1-antitrypsin, cytochrome P450 subunits 2b9 and 2b13 and tyrosine aminotransferase transcripts are upregulated. Quantitative RT-PCR data revealed a fetal hepatic phenotype corresponding to day 13-14 of liver development. Terminally differentiated hepatocyte-like cells show a bi-nucleated, cuboidal morphology labeled by albumin, alpha-1-antitrypsin, liver amylase, dipeptidyl peptidase IV, c-met and cytokeratin 18. ES-derived intermediate cell types transiently and partially co-express nestin with albumin and alpha-fetoprotein, respectively, but not cytokeratin 19. This finding suggests an ES-derived potential hepatic progenitor cell type, which is partially nestin-, albumin- and alpha-fetoprotein-positive, but cytokeratin 19-negative.
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Affiliation(s)
- Gabriela Kania
- In vitro Differentiation Group, IPK Gatersleben, D-06466 Gatersleben, Germany
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46
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de Paula RM, Wilson WA, Terenzi HF, Roach PJ, Bertolini MC. GNN is a self-glucosylating protein involved in the initiation step of glycogen biosynthesis in Neurospora crassa. Arch Biochem Biophys 2005; 435:112-24. [PMID: 15680913 DOI: 10.1016/j.abb.2004.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Revised: 12/02/2004] [Indexed: 10/26/2022]
Abstract
The initiation of glycogen synthesis requires the protein glycogenin, which incorporates glucose residues through a self-glucosylation reaction, and then acts as substrate for chain elongation by glycogen synthase and branching enzyme. Numerous sequences of glycogenin-like proteins are available in the databases but the enzymes from mammalian skeletal muscle and from Saccharomyces cerevisiae are the best characterized. We report the isolation of a cDNA from the fungus Neurospora crassa, which encodes a protein, GNN, which has properties characteristic of glycogenin. The protein is one of the largest glycogenins but shares several conserved domains common to other family members. Recombinant GNN produced in Escherichia coli was able to incorporate glucose in a self-glucosylation reaction, to trans-glucosylate exogenous substrates, and to act as substrate for chain elongation by glycogen synthase. Recombinant protein was sensitive to C-terminal proteolysis, leading to stable species of around 31kDa, which maintained all functional properties. The role of GNN as an initiator of glycogen metabolism was confirmed by its ability to complement the glycogen deficiency of a S. cerevisiae strain (glg1 glg2) lacking glycogenin and unable to accumulate glycogen. Disruption of the gnn gene of N. crassa by repeat induced point mutation (RIP) resulted in a strain that was unable to synthesize glycogen, even though the glycogen synthase activity was unchanged. Northern blot analysis showed that the gnn gene was induced during vegetative growth and was repressed upon carbon starvation.
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Affiliation(s)
- Renato Magalhães de Paula
- Instituto de Química, UNESP, Departamento de Bioquímica e Tecnologia Química, 14800-900 Araraquara, SP, Brazil
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47
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Horváth J, Ketelsen UP, Geibel-Zehender A, Boehm N, Olbrich H, Korinthenberg R, Omran H. Identification of a novel LAMP2 mutation responsible for X-chromosomal dominant Danon disease. Neuropediatrics 2003; 34:270-3. [PMID: 14598234 DOI: 10.1055/s-2003-43262] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Danon disease (DD) is a rare lysosomal glycogen storage disease with normal acid maltase activity, which is characterised clinically by cardiomyopathy and myopathy, and a variable degree of mental retardation. The causative gene, LAMP2, has been mapped to chromosome Xq24-q25. LAMP2 encodes a lysosome-associated membrane glycoprotein. We identified a novel LAMP2 mutation of the exon 8 splice acceptor site (IVS7-1G --> A) in an affected male and female, which predicts abnormal splicing. Both affected individuals presented solely with hypertrophic cardiomyopathy. Muscle weakness and mental impairment were absent. Diagnosis of Danon disease was established by muscle biopsy, when the male index patient developed transient severe muscle weakness following heart transplantation. Typical biopsy findings were also found in a heart muscle specimen. Demonstration of the LAMP2 mutation in affected male and female siblings is compatible with X-linked dominant inheritance. Danon disease should be actively looked for in cardiomyopathy patients.
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Affiliation(s)
- J Horváth
- Department of Pediatric Neurology and Muscle Disease, University Children's Hospital Freiburg, Mathildenstrasse 1, 79106 Freiburg, Germany
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48
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Bernard-Hélary K, Ardourel M, Magistretti P, Hévor T, Cloix JF. Stable transfection of cDNAs targeting specific steps of glycogen metabolism supports the existence of active gluconeogenesis in mouse cultured astrocytes. Glia 2002; 37:379-82. [PMID: 11870877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
In order to assess the participation of astrocytic gluconeogenesis in the synthesis of glycogen, mouse astrocytes were stably transfected with antisense cDNA of fructose-1,6-bisphosphatase (FBPase) and with sense and antisense cDNAs of glycogen synthase (GS). The antisenses of FBPase and GS have similar significant effect in decreasing astrocyte glycogen content by 60%, while sense GS significantly increased glycogen content by 100%. The FBPase activity was decreased by all three cDNAs used, while glycogen phosphorylase was not altered. The activity of GS was decreased by the antisense GS and increased by the sense GS. These data demonstrate that the gluconeogenesis in astrocytes is involved in the glycogenesis modulation.
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Affiliation(s)
- Katy Bernard-Hélary
- Métabolisme Cérébral et Neuropathologies, UPRES EA 2633, Université d'Orléans, Orléans, France
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49
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Aguilera I, García-Lozano JR, Muñoz A, Arenas J, Campos Y, Chinchón I, Roldán AN, Bautista J. Mitochondrial DNA point mutation in the COI gene in a patient with McArdle's disease. J Neurol Sci 2001; 192:81-4. [PMID: 11701156 DOI: 10.1016/s0022-510x(01)00634-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We studied a 57-year-old female patient with clinical and biochemical evidences of McArdle's disease. Her muscle biopsy also revealed signs of mitochondrial proliferation, scattered RRF, and a deficit in complex I of the respiratory chain. Molecular genetic analysis showed that the patient was heterozygous for the most common mutation at codon 49 in the myophosphorylase gene. Mitochondrial DNA analysis of muscle tissue revealed an additional G-to-A transition at nucleotide position 7444 in the cytochrome c oxidase subunit I (COI) gene.
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MESH Headings
- Codon/genetics
- DNA Mutational Analysis
- DNA, Mitochondrial/genetics
- Electron Transport Complex I
- Electron Transport Complex IV/genetics
- Energy Metabolism/genetics
- Exons/genetics
- Female
- Glycogen/genetics
- Glycogen/metabolism
- Glycogen Phosphorylase, Muscle Form/deficiency
- Glycogen Phosphorylase, Muscle Form/genetics
- Glycogen Storage Disease Type V/genetics
- Glycogen Storage Disease Type V/metabolism
- Glycogen Storage Disease Type V/physiopathology
- Humans
- Middle Aged
- Mitochondria, Muscle/genetics
- Mitochondria, Muscle/metabolism
- Mitochondria, Muscle/pathology
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/pathology
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- NADH, NADPH Oxidoreductases/deficiency
- NADH, NADPH Oxidoreductases/genetics
- Point Mutation/genetics
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Affiliation(s)
- I Aguilera
- Servicios de Inmunología, Hospital Universitario Virgen del Rocío, Avda Manuel Siurot s/n, 41013 Seville, Spain.
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50
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Coulary B, Aigle M, Schaeffer J. Evidence for glycogen structures associated with plasma membrane invaginations as visualized by freeze-substitution and the Thiery reaction in Saccharomyces cerevisiae. QJM 2001; 50:133-7. [PMID: 11347714 DOI: 10.1093/jmicro/50.2.133] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
We have used a combination of freeze-substitution electron microscopy and specific reaction for polysaccharides to re-evaluate glycogen structures in Saccharomyces cerevisiae. We also used mutant cells devoid of glycogen to confirm the glycogenic nature of the structures described. Previously described cytoplasmic aggregates were confirmed as glycogen granules. Moreover, an original structure was discovered. This is a ring of glycogen surrounding a finger- or pleat-like plasma membrane invagination. This structure could be physiologically significant in terms of channelling glucose to or from glycogen reserves.
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