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Kim K, Varghese M, Sun H, Abrishami S, Bowers E, Bridges D, Meijer JL, Singer K, Gregg B. The Influence of Maternal High Fat Diet During Lactation on Offspring Hematopoietic Priming. Endocrinology 2023; 165:bqad182. [PMID: 38048597 PMCID: PMC11032250 DOI: 10.1210/endocr/bqad182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/06/2023]
Abstract
Obesity and metabolic diseases are rising among women of reproductive age, increasing offspring metabolic risk. Maternal nutritional interventions during lactation present an opportunity to modify offspring outcomes. We previously demonstrated in mice that adult male offspring have metabolic impairments and increased adipose tissue macrophages (ATM) when dams are fed high fat diet (HFD) during the postnatal lactation window (HFD PN). We sought to understand the effect of HFD during lactation on early-life inflammation. HFD PN offspring were evaluated at postnatal day 16 to 19 for tissue weight and gene expression. Profiling of adipose tissue and bone marrow immune cells was conducted through lipidomics, in vitro myeloid colony forming unit assays, and flow cytometry. HFD PN mice had more visceral gonadal white adipose tissue (GWAT) and subcutaneous fat. Adipose tissue RNA sequencing demonstrated enrichment of inflammation, chemotaxis, and fatty acid metabolism and concordant changes in GWAT lipidomics. Bone marrow (BM) of both HFD PN male and female offspring had increased monocytes (CD45+Ly6G-CD11b+CD115+) and B cells (CD45+Ly6G-CD11b-CD19+). Similarly, serum from HFD PN offspring enhanced in vitro BM myeloid colonies in a toll-like receptor 4-dependent manner. We identified that male HFD PN offspring had increased GWAT pro-inflammatory CD11c+ ATMs (CD45+CD64+). Maternal exposure to HFD alters milk lipids enhancing adiposity and myeloid inflammation even in early life. Future studies are needed to understand the mechanisms driving this pro-inflammatory state of both BM and ATMs, the causes of the sexually dimorphic phenotypes, and the feasibility of intervening in this window to improve metabolic health.
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Affiliation(s)
- Katherine Kim
- Department of Pediatrics, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mita Varghese
- Department of Pediatrics, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Haijing Sun
- Department of Pediatrics, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Simin Abrishami
- Department of Pediatrics, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Emily Bowers
- Department of Pediatrics, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Dave Bridges
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA
| | - Jennifer L Meijer
- Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA
- Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Kanakadurga Singer
- Department of Pediatrics, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Brigid Gregg
- Department of Pediatrics, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA
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2
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Rodríguez‐Barrueco R, Latorre J, Devis‐Jáuregui L, Lluch A, Bonifaci N, Llobet FJ, Olivan M, Coll‐Iglesias L, Gassner K, Davis ML, Moreno‐Navarrete JM, Castells‐Nobau A, Plata‐Peña L, Dalmau‐Pastor M, Höring M, Liebisch G, Olkkonen VM, Arnoriaga‐Rodríguez M, Ricart W, Fernández‐Real JM, Silva JM, Ortega FJ, Llobet‐Navas D. A microRNA Cluster Controls Fat Cell Differentiation and Adipose Tissue Expansion By Regulating SNCG. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104759. [PMID: 34898027 PMCID: PMC8811811 DOI: 10.1002/advs.202104759] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Indexed: 05/08/2023]
Abstract
The H19X-encoded miR-424(322)/503 cluster regulates multiple cellular functions. Here, it is reported for the first time that it is also a critical linchpin of fat mass expansion. Deletion of this miRNA cluster in mice results in obesity, while increasing the pool of early adipocyte progenitors and hypertrophied adipocytes. Complementary loss and gain of function experiments and RNA sequencing demonstrate that miR-424(322)/503 regulates a conserved genetic program involved in the differentiation and commitment of white adipocytes. Mechanistically, it is demonstrated that miR-424(322)/503 targets γ-Synuclein (SNCG), a factor that mediates this program rearrangement by controlling metabolic functions in fat cells, allowing adipocyte differentiation and adipose tissue enlargement. Accordingly, diminished miR-424(322) in mice and obese humans co-segregate with increased SNCG in fat and peripheral blood as mutually exclusive features of obesity, being normalized upon weight loss. The data unveil a previously unknown regulatory mechanism of fat mass expansion tightly controlled by the miR-424(322)/503 through SNCG.
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Affiliation(s)
- Ruth Rodríguez‐Barrueco
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
- Anatomy UnitDepartment of Pathology and Experimental TherapySchool of MedicineUniversity of Barcelona (UB)L'Hospitalet de Llobregat08907Spain
| | - Jessica Latorre
- Department of DiabetesEndocrinology, and Nutrition (UDEN)Institut d'Investigació Biomèdica de Girona (IDIBGI)Salt17190Spain
- Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y la Nutrición (CIBEROBN)Instituto de Salud Carlos III (ISCIII)Madrid28029Spain
| | - Laura Devis‐Jáuregui
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
| | - Aina Lluch
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
- Department of DiabetesEndocrinology, and Nutrition (UDEN)Institut d'Investigació Biomèdica de Girona (IDIBGI)Salt17190Spain
| | - Nuria Bonifaci
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC)Instituto de Salud Carlos III, (ISCIII)Madrid28029Spain
| | - Francisco J. Llobet
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
| | - Mireia Olivan
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
- Anatomy UnitDepartment of Pathology and Experimental TherapySchool of MedicineUniversity of Barcelona (UB)L'Hospitalet de Llobregat08907Spain
| | - Laura Coll‐Iglesias
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
| | - Katja Gassner
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC)Instituto de Salud Carlos III, (ISCIII)Madrid28029Spain
| | - Meredith L. Davis
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
- Department of PathologyDuke University School of MedicineDurhamNC27710USA
| | - José M. Moreno‐Navarrete
- Department of DiabetesEndocrinology, and Nutrition (UDEN)Institut d'Investigació Biomèdica de Girona (IDIBGI)Salt17190Spain
- Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y la Nutrición (CIBEROBN)Instituto de Salud Carlos III (ISCIII)Madrid28029Spain
| | - Anna Castells‐Nobau
- Department of DiabetesEndocrinology, and Nutrition (UDEN)Institut d'Investigació Biomèdica de Girona (IDIBGI)Salt17190Spain
| | - Laura Plata‐Peña
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
| | - Miki Dalmau‐Pastor
- Anatomy UnitDepartment of Pathology and Experimental TherapySchool of MedicineUniversity of Barcelona (UB)L'Hospitalet de Llobregat08907Spain
- MIFAS by GRECMIP (Minimally Invasive Foot and Ankle Society)Merignac33700France
| | - Marcus Höring
- Institute of Clinical Chemistry and Laboratory MedicineRegensburg University HospitalRegensburg93053Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory MedicineRegensburg University HospitalRegensburg93053Germany
| | - Vesa M. Olkkonen
- Minerva Foundation Institute for Medical Research (Biomedicum 2U)and Department of AnatomyFaculty of MedicineUniversity of HelsinkiHelsinki00290Finland
| | - Maria Arnoriaga‐Rodríguez
- Department of DiabetesEndocrinology, and Nutrition (UDEN)Institut d'Investigació Biomèdica de Girona (IDIBGI)Salt17190Spain
- Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y la Nutrición (CIBEROBN)Instituto de Salud Carlos III (ISCIII)Madrid28029Spain
| | - Wifredo Ricart
- Department of DiabetesEndocrinology, and Nutrition (UDEN)Institut d'Investigació Biomèdica de Girona (IDIBGI)Salt17190Spain
- Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y la Nutrición (CIBEROBN)Instituto de Salud Carlos III (ISCIII)Madrid28029Spain
| | - José M. Fernández‐Real
- Department of DiabetesEndocrinology, and Nutrition (UDEN)Institut d'Investigació Biomèdica de Girona (IDIBGI)Salt17190Spain
- Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y la Nutrición (CIBEROBN)Instituto de Salud Carlos III (ISCIII)Madrid28029Spain
| | - José M. Silva
- Department of PathologyIcahn School of Medicine at Mount SinaiNew YorkNY10029USA
| | - Francisco J. Ortega
- Department of DiabetesEndocrinology, and Nutrition (UDEN)Institut d'Investigació Biomèdica de Girona (IDIBGI)Salt17190Spain
- Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y la Nutrición (CIBEROBN)Instituto de Salud Carlos III (ISCIII)Madrid28029Spain
| | - David Llobet‐Navas
- Molecular Mechanisms and Experimental Therapy in Oncology‐Oncobell ProgramBellvitge Biomedical Research Institute (IDIBELL)L'Hospitalet de Llobregat08908Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC)Instituto de Salud Carlos III, (ISCIII)Madrid28029Spain
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3
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Guschina IA, Ninkina N, Roman A, Pokrovskiy MV, Buchman VL. Triple-Knockout, Synuclein-Free Mice Display Compromised Lipid Pattern. Molecules 2021; 26:molecules26113078. [PMID: 34064018 PMCID: PMC8196748 DOI: 10.3390/molecules26113078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/05/2021] [Accepted: 05/11/2021] [Indexed: 11/29/2022] Open
Abstract
Recent studies have implicated synucleins in several reactions during the biosynthesis of lipids and fatty acids in addition to their recognised role in membrane lipid binding and synaptic functions. These are among aspects of decreased synuclein functions that are still poorly acknowledged especially in regard to pathogenesis in Parkinson’s disease. Here, we aimed to add to existing knowledge of synuclein deficiency (i.e., the lack of all three family members), with respect to changes in fatty acids and lipids in plasma, liver, and two brain regions in triple synuclein-knockout (TKO) mice. We describe changes of long-chain polyunsaturated fatty acids (LCPUFA) and palmitic acid in liver and plasma, reduced triacylglycerol (TAG) accumulation in liver and non-esterified fatty acids in plasma of synuclein free mice. In midbrain, we observed counterbalanced changes in the relative concentrations of phosphatidylcholine (PC) and cerebrosides (CER). We also recorded a notable reduction in ethanolamine plasmalogens in the midbrain of synuclein free mice, which is an important finding since the abnormal ether lipid metabolism usually associated with neurological disorders. In summary, our data demonstrates that synuclein deficiency results in alterations of the PUFA synthesis, storage lipid accumulation in the liver, and the reduction of plasmalogens and CER, those polar lipids which are principal compounds of lipid rafts in many tissues. An ablation of all three synuclein family members causes more profound changes in lipid metabolism than changes previously shown to be associated with γ-synuclein deficiency alone. Possible mechanisms by which synuclein deficiency may govern the reported modifications of lipid metabolism in TKO mice are proposed and discussed.
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Affiliation(s)
- Irina A. Guschina
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK; (N.N.); (A.R.); (V.L.B.)
- Correspondence:
| | - Natalia Ninkina
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK; (N.N.); (A.R.); (V.L.B.)
- Institute of Physiologically Active Compounds Russian Academy of Sciences (IPAC RAS), 1 Severniy Proezd, Chernogolovka 142432, Moscow Region, Russia
| | - Andrei Roman
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK; (N.N.); (A.R.); (V.L.B.)
- Institute of Physiologically Active Compounds Russian Academy of Sciences (IPAC RAS), 1 Severniy Proezd, Chernogolovka 142432, Moscow Region, Russia
| | - Mikhail V. Pokrovskiy
- Research Institute of Living Systems Pharmacology, Belgorod State National Research University, 85 Pobedy Street, Belgorod 308015, Belgorod Oblast, Russia;
| | - Vladimir L. Buchman
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK; (N.N.); (A.R.); (V.L.B.)
- Institute of Physiologically Active Compounds Russian Academy of Sciences (IPAC RAS), 1 Severniy Proezd, Chernogolovka 142432, Moscow Region, Russia
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4
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Runwal G, Edwards RH. The Membrane Interactions of Synuclein: Physiology and Pathology. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2021; 16:465-485. [PMID: 33497259 DOI: 10.1146/annurev-pathol-031920-092547] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Specific proteins accumulate in neurodegenerative disease, and human genetics has indicated a causative role for many. In most cases, however, the mechanisms remain poorly understood. Degeneration is thought to involve a gain of abnormal function, although we do not know the normal function of many proteins implicated. The protein α-synuclein accumulates in the Lewy pathology of Parkinson's disease and related disorders, and mutations in α-synuclein cause degeneration, but we have not known its normal function or how it triggers disease. α-Synuclein localizes to presynaptic boutons and interacts with membranes in vitro. Overexpression slows synaptic vesicle exocytosis, and recent data suggest a normal role for the endogenous synucleins in dilation of the exocytic fusion pore. Disrupted membranes also appear surprisingly prominent in Lewy pathology. Synuclein thus interacts with membranes under both physiological and pathological conditions, suggesting that the normal function of synuclein may illuminate its role in degeneration.
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Affiliation(s)
- Gautam Runwal
- Departments of Neurology and Physiology, Graduate Programs in Cell Biology, Biomedical Sciences and Neuroscience, School of Medicine, University of California, San Francisco, California 94143, USA;
| | - Robert H Edwards
- Departments of Neurology and Physiology, Graduate Programs in Cell Biology, Biomedical Sciences and Neuroscience, School of Medicine, University of California, San Francisco, California 94143, USA;
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5
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Chaprov K, Rezvykh A, Funikov S, Ivanova TA, Lysikova EA, Deykin AV, Kukharsky MS, Yu Aksinenko A, Bachurin SO, Ninkina N, Buchman VL. A bioisostere of Dimebon/Latrepirdine delays the onset and slows the progression of pathology in FUS transgenic mice. CNS Neurosci Ther 2021; 27:765-775. [PMID: 33754495 PMCID: PMC8193697 DOI: 10.1111/cns.13637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 03/04/2021] [Accepted: 03/07/2021] [Indexed: 12/13/2022] Open
Abstract
Aims To assess effects of DF402, a bioisostere of Dimebon/Latrepirdine, on the disease progression in the transgenic model of amyotrophic lateral sclerosis (ALS) caused by expression of pathogenic truncated form of human FUS protein. Methods Mice received DF402 from the age of 42 days and the onset of clinical signs, the disease duration and animal lifespan were monitored for experimental and control animals, and multiple parameters of their gait were assessed throughout the pre‐symptomatic stage using CatWalk system followed by a bioinformatic analysis. RNA‐seq was used to compare the spinal cord transcriptomes of wild‐type, untreated, and DF402‐treated FUS transgenic mice. Results DF402 delays the onset and slows the progression of pathology. We developed a CatWalk analysis protocol that allows detection of gait changes in FUS transgenic mice and the effect of DF402 on their gait already at early pre‐symptomatic stage. At this stage, a limited number of genes significantly change expression in transgenic mice and for 60% of these genes, DF402 treatment causes the reversion of the expression pattern. Conclusion DF402 slows down the disease progression in the mouse model of ALS, which is consistent with previously reported neuroprotective properties of Dimebon and its other bioisosteres. These results suggest that these structures can be considered as lead compounds for further optimization to obtain novel medicines that might be used as components of complex ALS therapy.
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Affiliation(s)
- Kirill Chaprov
- Institute of Physiologically Active Compounds, Russian Academy of Science, Chernogolovka, Russia
| | - Alexander Rezvykh
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Sergei Funikov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Tamara A Ivanova
- Institute of Physiologically Active Compounds, Russian Academy of Science, Chernogolovka, Russia
| | - Ekaterina A Lysikova
- Institute of Physiologically Active Compounds, Russian Academy of Science, Chernogolovka, Russia
| | - Alexei V Deykin
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,Laboratory of Genome Editing for Veterinary and Biomedicine, Belgorod State National Research University, Belgorod region, Russia
| | - Michail S Kukharsky
- Institute of Physiologically Active Compounds, Russian Academy of Science, Chernogolovka, Russia.,Pirogov Russian National Research Medical University, Moscow, Russia.,School of Biosciences, Cardiff University, Cardiff, UK
| | - Alexey Yu Aksinenko
- Institute of Physiologically Active Compounds, Russian Academy of Science, Chernogolovka, Russia
| | - Sergey O Bachurin
- Institute of Physiologically Active Compounds, Russian Academy of Science, Chernogolovka, Russia
| | - Natalia Ninkina
- Institute of Physiologically Active Compounds, Russian Academy of Science, Chernogolovka, Russia.,School of Biosciences, Cardiff University, Cardiff, UK
| | - Vladimir L Buchman
- Institute of Physiologically Active Compounds, Russian Academy of Science, Chernogolovka, Russia.,School of Biosciences, Cardiff University, Cardiff, UK
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6
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Lugol Increases Lipolysis through Upregulation of PPAR-Gamma and Downregulation of C/EBP-Alpha in Mature 3T3-L1 Adipocytes. J Nutr Metab 2020; 2020:2302795. [PMID: 33014457 PMCID: PMC7519197 DOI: 10.1155/2020/2302795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 08/03/2020] [Accepted: 09/04/2020] [Indexed: 11/20/2022] Open
Abstract
Overweight and obesity are defined as excessive and abnormal fat accumulation that is harmful to health. This study analyzes the effect of different concentrations of the lugol solution (molecular iodine dissolved in potassium iodide) on lipolysis in cultured 3T3-L1-differentiated adipocytes. The mature adipocytes were treated with doses from 1 to 100 µm of lugol for 0.5, 6, and 24 h. The results showed that mature adipocytes exposed to lugol decrease their viability and increase caspase-3 activity with a lethal dose (LD50) of 473 µm. In mature adipocytes, lugol decreased the total intracellular lipid content, being significant at doses of 10 and 100 µm after 6 and 24 h of treatment (P < 0.01), and the accumulation of intracellular triglycerides decreased after 24 h of exposure to lugol (P < 0.05). Lugol treatment significantly increases the release of glycerol to the culture medium (P < 0.05). The levels of adipocyte-specific transcription factors C/EBP-α were downregulated and PPAR-γ upregulated after 30 min with lugol. These results indicate a lipolytic effect of lugol dependent on PPAR-γ and C/EBP-α expression in mature 3T3-L1 adipocytes.
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7
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Low Level of Expression of C-Terminally Truncated Human FUS Causes Extensive Changes in the Spinal Cord Transcriptome of Asymptomatic Transgenic Mice. Neurochem Res 2020; 45:1168-1179. [PMID: 32157564 DOI: 10.1007/s11064-020-02999-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 12/13/2022]
Abstract
A number of mutations in a gene encoding RNA-binding protein FUS have been linked to the development of a familial form of amyotrophic lateral sclerosis known as FUS-ALS. C-terminal truncations of FUS by either nonsense or frameshift mutations lead to the development of FUS-ALS with a particularly early onset and fast progression. However, even in patients bearing these highly pathogenic mutations the function of motor neurons is not noticeably compromised for at least a couple of decades, suggesting that until cytoplasmic levels of FUS lacking its C-terminal nuclear localisation signal reaches a critical threshold, motor neurons are able to tolerate its permanent production. In order to identify how the nervous system responds to low levels of pathogenic variants of FUS we produced and characterised a mouse line, L-FUS[1-359], with a low neuronal expression level of a highly aggregation-prone and pathogenic form of C-terminally truncated FUS. In contrast to mice that express substantially higher level of the same FUS variant and develop severe early onset motor neuron pathology, L-FUS[1-359] mice do not develop any clinical or histopathological signs of motor neuron deficiency even at old age. Nevertheless, we detected substantial changes in the spinal cord transcriptome of these mice compared to their wild type littermates. We suggest that at least some of these changes reflect activation of cellular mechanisms compensating for the potentially damaging effect of pathogenic FUS production. Further studies of these mechanism might reveal effective targets for therapy of FUS-ALS and possibly, other forms of ALS.
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8
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Alza NP, Iglesias González PA, Conde MA, Uranga RM, Salvador GA. Lipids at the Crossroad of α-Synuclein Function and Dysfunction: Biological and Pathological Implications. Front Cell Neurosci 2019; 13:175. [PMID: 31118888 PMCID: PMC6504812 DOI: 10.3389/fncel.2019.00175] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/11/2019] [Indexed: 12/15/2022] Open
Abstract
Since its discovery, the study of the biological role of α-synuclein and its pathological implications has been the subject of increasing interest. The propensity to adopt different conformational states governing its aggregation and fibrillation makes this small 14-kDa cytosolic protein one of the main etiologic factors associated with degenerative disorders known as synucleinopathies. The structure, function, and toxicity of α-synuclein and the possibility of different therapeutic approaches to target the protein have been extensively investigated and reviewed. One intriguing characteristic of α-synuclein is the different ways in which it interacts with lipids. Though in-depth studies have been carried out in this field, the information they have produced is puzzling and the precise role of lipids in α-synuclein biology and pathology and vice versa is still largely unknown. Here we provide an overview and discussion of the main findings relating to α-synuclein/lipid interaction and its involvement in the modulation of lipid metabolism and signaling.
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Affiliation(s)
- Natalia P Alza
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional del Sur, Bahía Blanca, Argentina.,Departamento de Química, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Pablo A Iglesias González
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Melisa A Conde
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional del Sur, Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Romina M Uranga
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional del Sur, Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Gabriela A Salvador
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional del Sur, Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
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9
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Čopič A, Antoine-Bally S, Giménez-Andrés M, La Torre Garay C, Antonny B, Manni MM, Pagnotta S, Guihot J, Jackson CL. A giant amphipathic helix from a perilipin that is adapted for coating lipid droplets. Nat Commun 2018; 9:1332. [PMID: 29626194 PMCID: PMC5889406 DOI: 10.1038/s41467-018-03717-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 03/05/2018] [Indexed: 11/21/2022] Open
Abstract
How proteins are targeted to lipid droplets (LDs) and distinguish the LD surface from the surfaces of other organelles is poorly understood, but many contain predicted amphipathic helices (AHs) that are involved in targeting. We have focused on human perilipin 4 (Plin4), which contains an AH that is exceptional in terms of length and repetitiveness. Using model cellular systems, we show that AH length, hydrophobicity, and charge are important for AH targeting to LDs and that these properties can compensate for one another, albeit at a loss of targeting specificity. Using synthetic lipids, we show that purified Plin4 AH binds poorly to lipid bilayers but strongly interacts with pure triglycerides, acting as a coat and forming small oil droplets. Because Plin4 overexpression alleviates LD instability under conditions where their coverage by phospholipids is limiting, we propose that the Plin4 AH replaces the LD lipid monolayer, for example during LD growth. Lipid droplets are cellular organelles important for cellular homeostasis and their disruption has been implicated in many diseases. Here the authors use a large amphipathic helix from perilipin 4 to uncover parameters important for specific lipid droplet targeting and stabilization of the oil core.
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Affiliation(s)
- Alenka Čopič
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France.
| | - Sandra Antoine-Bally
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France
| | - Manuel Giménez-Andrés
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France.,Université Paris-Sud, Université Paris-Saclay, 91405, Orsay, France
| | - César La Torre Garay
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France
| | - Bruno Antonny
- Université Côte d'Azur, CNRS, IPMC, 06560, Valbonne, France
| | - Marco M Manni
- Université Côte d'Azur, CNRS, IPMC, 06560, Valbonne, France
| | | | - Jeanne Guihot
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France
| | - Catherine L Jackson
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75013, Paris, France
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Loss of α-Synuclein Does Not Affect Mitochondrial Bioenergetics in Rodent Neurons. eNeuro 2017; 4:eN-NRS-0216-16. [PMID: 28462393 PMCID: PMC5409983 DOI: 10.1523/eneuro.0216-16.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 04/02/2017] [Accepted: 04/06/2017] [Indexed: 12/28/2022] Open
Abstract
Increased α-synuclein (αsyn) and mitochondrial dysfunction play central roles in the pathogenesis of Parkinson’s disease (PD), and lowering αsyn is under intensive investigation as a therapeutic strategy for PD. Increased αsyn levels disrupt mitochondria and impair respiration, while reduced αsyn protects against mitochondrial toxins, suggesting that interactions between αsyn and mitochondria influences the pathologic and physiologic functions of αsyn. However, we do not know if αsyn affects normal mitochondrial function or if lowering αsyn levels impacts bioenergetic function, especially at the nerve terminal where αsyn is enriched. To determine if αsyn is required for normal mitochondrial function in neurons, we comprehensively evaluated how lowering αsyn affects mitochondrial function. We found that αsyn knockout (KO) does not affect the respiration of cultured hippocampal neurons or cortical and dopaminergic synaptosomes, and that neither loss of αsyn nor all three (α, β and γ) syn isoforms decreased mitochondria-derived ATP levels at the synapse. Similarly, neither αsyn KO nor knockdown altered the capacity of synaptic mitochondria to meet the energy requirements of synaptic vesicle cycling or influenced the localization of mitochondria to dopamine (DA) synapses in vivo. Finally, αsyn KO did not affect overall energy metabolism in mice assessed with a Comprehensive Lab Animal Monitoring System. These studies suggest either that αsyn has little or no significant physiological effect on mitochondrial bioenergetic function, or that any such functions are fully compensated for when lost. These results implicate that αsyn levels can be reduced in neurons without impairing (or improving) mitochondrial bioenergetics or distribution.
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European Obesity Summit (EOS) - Joint Congress of EASOand IFSO-EC, Gothenburg, Sweden, June 1 - 4, 2016: Abstracts. Obes Facts 2016; 9 Suppl 1:1-376. [PMID: 27238363 PMCID: PMC5672850 DOI: 10.1159/000446744] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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12
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Shen WJ, Azhar S, Kraemer FB. Lipid droplets and steroidogenic cells. Exp Cell Res 2015; 340:209-14. [PMID: 26639173 DOI: 10.1016/j.yexcr.2015.11.024] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 02/05/2023]
Abstract
Lipid droplets (LDs) in steroidogenic tissues have a cholesteryl ester (CE) core surrounded by a phospholipid monolayer that is coated with associated proteins. Compared with other tissues, they tend to be smaller in size and more numerous in numbers. These LDs are enriched with PLIN1c, PLIN2 and PLIN3. Both CIDE A and B are found in mouse ovary. Free cholesterol (FC) released upon hormone stimulation from LDs is the preferred source of cholesterol substrate for steroidogenesis, and HSL is the major neutral cholesterol esterase mediating the conversion of CEs to FC. Through the interaction of HSL with vimentin and StAR, FC is translocated to mitochondria for steroid hormone production. Proteomic analyses of LDs isolated from loaded primary ovarian granulosa cells, mouse MLTC-1 Leydig tumor cells and mouse testes revealed LD associated proteins that are actively involved in modulating lipid homeostasis along with a number of steroidogenic enzymes. Microscopy analysis confirmed the localization of many of these proteins to LDs. These studies broaden the role of LDs to include being a platform for functional steroidogenic enzyme activity or as a port for transferring steroidogenic enzymes and/or steroid intermediates, in addition to being a storage depot for CEs.
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Affiliation(s)
- Wen-Jun Shen
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States
| | - Salman Azhar
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States
| | - Fredric B Kraemer
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States.
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Mansuy-Aubert V, Gautron L, Lee S, Bookout AL, Kusminski C, Sun K, Zhang Y, Scherer PE, Mangelsdorf DJ, Elmquist JK. Loss of the liver X receptor LXRα/β in peripheral sensory neurons modifies energy expenditure. eLife 2015; 4. [PMID: 26076474 PMCID: PMC4467361 DOI: 10.7554/elife.06667] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 05/14/2015] [Indexed: 11/13/2022] Open
Abstract
Peripheral neural sensory mechanisms play a crucial role in metabolic regulation but less is known about the mechanisms underlying vagal sensing itself. Recently, we identified an enrichment of liver X receptor alpha and beta (LXRα/β) in the nodose ganglia of the vagus nerve. In this study, we show mice lacking LXRα/β in peripheral sensory neurons have increased energy expenditure and weight loss when fed a Western diet (WD). Our findings suggest that the ability to metabolize and sense cholesterol and/or fatty acids in peripheral neurons is an important requirement for physiological adaptations to WDs. DOI:http://dx.doi.org/10.7554/eLife.06667.001 The vagus nerves run from the brainstem to the heart and the digestive system and help to control several processes including digestion and heart rate. Because of their role in regulating food intake, these nerves are attractive targets for scientists hoping to develop treatments for obesity. There are two types of fat tissue found in mammals: white fat, which is used as an energy store and makes up most of the extra fat seen in obese individuals; and brown fat, which can generate body heat. The vagus nerves monitor fat and cholesterol levels in the body via receptor proteins that respond to messages sent from the fat tissues and the liver. Previous research unexpectedly found that mice genetically engineered to lack these receptor proteins—called LXRα and LXRβ—do not become obese even when fed a high-fat, high-cholesterol diet that would make normal mice gain excessive weight. Mansuy-Aubert et al. have now investigated in more detail why mice without these receptor proteins are resistant to obesity. When fed a high-fat, high-cholesterol diet, mice that lacked the LXRα and LXRβ receptors in sensory neurons had higher cholesterol levels in their nerve cells than normal mice on the same diet. Mice lacking these receptors also burned more energy and gained less weight than normal mice. Next, Mansuy-Aubert et al. examined fat tissue from both types of mice. This revealed that the heat-generating brown fat was more active in mice lacking the LXRα and LXRβ receptors. Some of the white fat in these mice had also become more like brown fat, allowing the mice to burn more energy and so gain less weight. In many Western countries, many people also eat a diet that is high in fat and cholesterol. This raises the possibility that drugs that block the LXRα and LXRβ receptors in sensory neurons in humans could help to treat or prevent obesity, although further work will be needed to investigate this. DOI:http://dx.doi.org/10.7554/eLife.06667.002
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Affiliation(s)
- Virginie Mansuy-Aubert
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Laurent Gautron
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Syann Lee
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Angie L Bookout
- Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Christine Kusminski
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Kai Sun
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Yuan Zhang
- Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - David J Mangelsdorf
- Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Joel K Elmquist
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, United States
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Evaluation of the synuclein-γ (SNCG) gene as a PPARγ target in murine adipocytes, dorsal root ganglia somatosensory neurons, and human adipose tissue. PLoS One 2015; 10:e0115830. [PMID: 25756178 PMCID: PMC4355072 DOI: 10.1371/journal.pone.0115830] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 12/02/2014] [Indexed: 11/19/2022] Open
Abstract
Recent evidence in adipocytes points to a role for synuclein-γ in metabolism and lipid droplet dynamics, but interestingly this factor is also robustly expressed in peripheral neurons. Specific regulation of the synuclein-γ gene (Sncg) by PPARγ requires further evaluation, especially in peripheral neurons, prompting us to test if Sncg is a bona fide PPARγ target in murine adipocytes and peripheral somatosensory neurons derived from the dorsal root ganglia (DRG). Sncg mRNA was decreased in 3T3-L1 adipocytes (~68%) by rosiglitazone, and this effect was diminished by the PPARγ antagonist T0070907. Chromatin immunoprecipitation experiments confirmed PPARγ protein binding at two promoter sequences of Sncg during 3T3-L1 adipogenesis. Rosiglitazone did not affect Sncg mRNA expression in murine cultured DRG neurons. In subcutaneous human WAT samples from two cohorts treated with pioglitazone (>11 wks), SNCG mRNA expression was reduced, albeit highly variable and most evident in type 2 diabetes. Leptin (Lep) expression, thought to be coordinately-regulated with Sncg based on correlations in human adipose tissue, was also reduced in 3T3-L1 adipocytes by rosiglitazone. However, Lep was unaffected by PPARγ antagonist, and the LXR agonist T0901317 significantly reduced Lep expression (~64%) while not impacting Sncg. The results support the concept that synuclein-γ shares some, but not all, gene regulators with leptin and is a PPARγ target in adipocytes but not DRG neurons. Regulation of synuclein-γ by cues such as PPARγ agonism in adipocytes is logical based on recent evidence for an important role for synuclein-γ in the maintenance and dynamics of adipocyte lipid droplets.
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15
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Dunn TN, Adams SH. Relations between metabolic homeostasis, diet, and peripheral afferent neuron biology. Adv Nutr 2014; 5:386-93. [PMID: 25022988 PMCID: PMC4085187 DOI: 10.3945/an.113.005439] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
It is well established that food intake behavior and energy balance are regulated by crosstalk between peripheral organ systems and the central nervous system (CNS), for instance, through the actions of peripherally derived leptin on hindbrain and hypothalamic loci. Diet- or obesity-associated disturbances in metabolic and hormonal signals to the CNS can perturb metabolic homeostasis bodywide. Although interrelations between metabolic status and diet with CNS biology are well characterized, afferent networks (those sending information to the CNS from the periphery) have received far less attention. It is increasingly appreciated that afferent neurons in adipose tissue, the intestines, liver, and other tissues are important controllers of energy balance and feeding behavior. Disruption in their signaling may have consequences for cardiovascular, pancreatic, adipose, and immune function. This review discusses the diverse ways that afferent neurons participate in metabolic homeostasis and highlights how changes in their function associate with dysmetabolic states, such as obesity and insulin resistance.
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Affiliation(s)
- Tamara N. Dunn
- Graduate Group in Nutritional Biology and Department of Nutrition, University of California, Davis, CA; and
| | - Sean H. Adams
- Graduate Group in Nutritional Biology and Department of Nutrition, University of California, Davis, CA; and,Obesity and Metabolism Research Unit, USDA–Agricultural Research Service Western Human Nutrition Research Center, Davis, CA,To whom correspondence should be addressed. E-mail:
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Lytkina OA, Tarasova TV, Khritankova IV, Anokhin PK, Kukharsky MS, Ustyugov AA, Bachurin SO. Gamma-synuclein binds synaptic vesicles but does not interact with SNARE-complex proteins. DOKL BIOCHEM BIOPHYS 2014; 456:108-10. [PMID: 24993968 DOI: 10.1134/s1607672914030089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Indexed: 11/23/2022]
Affiliation(s)
- O A Lytkina
- Institute of Physiologically Active Substances, Russian Academy of Sciences, Chernogolovka, Moscow region, Russia,
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Murri M, Insenser M, Luque M, Tinahones FJ, Escobar-Morreale HF. Proteomic analysis of adipose tissue: informing diabetes research. Expert Rev Proteomics 2014; 11:491-502. [PMID: 24684164 DOI: 10.1586/14789450.2014.903158] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Diabetes, one of the most common endocrine diseases worldwide, results from complex pathophysiological mechanisms that are not fully understood. Adipose tissue is considered a major endocrine organ and plays a central role in the development of diabetes. The identification of the adipose tissue-derived factors that contribute to the onset and progression of diabetes will hopefully lead to the development of preventive and therapeutic interventions. Proteomic techniques may be useful tools for this purpose. In the present review, we have summarized the studies conducting adipose tissue proteomics in subjects with diabetes and insulin resistance, and discussed the proteins identified in these studies as candidates to exert important roles in these disorders.
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Affiliation(s)
- Mora Murri
- Department of Endocrinology and Nutrition, Diabetes, Obesity and Human Reproduction Research Group, Hospital Universitario Ramón y Cajal and Universidad de Alcalá and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) and Centro de Investigación Biomédica en Red Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), E-28034 Madrid, Spain
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Abstract
Human genetics has indicated a causal role for the protein α-synuclein in the pathogenesis of familial Parkinson's disease (PD), and the aggregation of synuclein in essentially all patients with PD suggests a central role for this protein in the sporadic disorder. Indeed, the accumulation of misfolded α-synuclein now defines multiple forms of neural degeneration. Like many of the proteins that accumulate in other neurodegenerative disorders, however, the normal function of synuclein remains poorly understood. In this article, we review the role of synuclein at the nerve terminal and in membrane remodeling. We also consider the prion-like propagation of misfolded synuclein as a mechanism for the spread of degeneration through the neuraxis.
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19
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Abstract
PURPOSE OF REVIEW With the realization that lipid droplets are not merely inert fat storage organelles, but highly dynamic and actively involved in cellular lipid homeostasis, there has been an increased interest in lipid droplet biology. Recent studies have begun to unravel the roles that lipid dropletss play in cellular physiology and provide insights into the mechanisms by which lipid droplets contribute to cellular homeostasis. This review provides a summary of these recent publications on lipid droplet metabolism. RECENT FINDINGS Perilipins have different preferences for associating with triacylglycerol (TAG) or cholesteryl esters, different tissue distributions, and each contributes to lipid metabolism in its unique way. Cell death-inducing DFF45-like effector proteins are not only involved in lipid droplet expansion, but also in the cellular response to stress and lipid secretion. Lipid droplets undergo an active cycle of lipolysis and re-esterification to form microlipid droplets. TAG synthesis for lipid droplet formation and expansion occurs in the endoplasmic reticulum and on lipid droplets, and TAG transfers between lipid droplets during lipid droplet fusion. Lipid droplets interact with the endoplasmic reticulum and mitochondria to facilitate lipid transfer, lipid droplet expansion, and metabolism. SUMMARY Lipid droplets are dynamically active, responding to changes in cellular physiology, as well as interacting with cytosolic proteins and other organelles to control lipid homeostasis.
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Affiliation(s)
- Victor K Khor
- aVeterans Affairs Palo Alto Healthcare System, Palo Alto bDivision of Endocrinology, Stanford University, Stanford, California, USA
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Millership S, Ninkina N, Rochford JJ, Buchman VL. γ-synuclein is a novel player in the control of body lipid metabolism. Adipocyte 2013; 2:276-80. [PMID: 24052906 PMCID: PMC3774706 DOI: 10.4161/adip.25162] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/21/2013] [Accepted: 05/23/2013] [Indexed: 12/11/2022] Open
Abstract
Synucleins are a family of homologous, predominantly neuronal proteins known for their involvement in synaptic transmission and neurodegeneration. γ-synuclein is predominantly localized in axons and presynaptic terminals of selected populations of peripheral and central neurons but is also highly expressed in human white adipose tissue (WAT) and increased in obesity. We have recently shown that γ-synuclein is nutritionally regulated in murine adipocytes while its loss protects mice from high fat diet (HFD)-induced obesity and associated metabolic complications. This protection was coupled with increased adipocyte lipolysis, lipid oxidation, and energy expenditure in HFD-fed γ-synuclein-null mutant compared with wild-type mice. Cellular studies suggest that relocalization of ATGL to the lipid droplet in γ-synuclein-deficient adipocytes may contribute to increased lipolysis in these cells. Loss of γ-synuclein in adipocytes also attenuates the assembly of SNARE complexes, an important component of lipid droplet fusion machinery, possibly due to reduced chaperoning of SNAP-23 to the assembling SNARE complex by γ-synuclein. Together our data suggests that not only is γ-synuclein a novel regulator of lipid handling in adipocytes but also that the deficiency of this protein has a significant effect on whole body energy expenditure.
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Senthivinayagam S, McIntosh AL, Moon KC, Atshaves BP. Plin2 inhibits cellular glucose uptake through interactions with SNAP23, a SNARE complex protein. PLoS One 2013; 8:e73696. [PMID: 24040030 PMCID: PMC3765312 DOI: 10.1371/journal.pone.0073696] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 07/25/2013] [Indexed: 11/19/2022] Open
Abstract
Although a link between excess lipid storage and aberrant glucose metabolism has been recognized for many years, little is known what role lipid storage droplets and associated proteins such as Plin2 play in managing cellular glucose levels. To address this issue, the influence of Plin2 on glucose uptake was examined using 2-NBD-Glucose and [(3)H]-2-deoxyglucose to show that insulin-mediated glucose uptake was decreased 1.7- and 1.8-fold, respectively in L cell fibroblasts overexpressing Plin2. Conversely, suppression of Plin2 levels by RNAi-mediated knockdown increased 2-NBD-Glucose uptake several fold in transfected L cells and differentiated 3T3-L1 cells. The effect of Plin2 expression on proteins involved in glucose uptake and transport was also examined. Expression of the SNARE protein SNAP23 was increased 1.6-fold while levels of syntaxin-5 were decreased 1.7-fold in Plin2 overexpression cells with no significant changes observed in lipid droplet associated proteins Plin1 or FSP27 or with the insulin receptor, GLUT1, or VAMP4. FRET experiments revealed a close proximity of Plin2 to SNAP23 on lipid droplets to within an intramolecular distance of 51 Å. The extent of targeting of SNAP23 to lipid droplets was determined by co-localization and co-immunoprecipitation experiments to show increased partitioning of SNAP23 to lipid droplets when Plin2 was overexpressed. Taken together, these results suggest that Plin2 inhibits glucose uptake by interacting with, and regulating cellular targeting of SNAP23 to lipid droplets. In summary, the current study for the first time provides direct evidence for the role of Plin2 in mediating cellular glucose uptake.
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Affiliation(s)
- Subramanian Senthivinayagam
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, United States of America
| | - Avery L. McIntosh
- Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas, United States of America
| | - Kenneth C. Moon
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, United States of America
| | - Barbara P. Atshaves
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail:
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Kokhan VS, Van'kin GI, Bachurin SO, Shamakina IY. Differential involvement of the gamma-synuclein in cognitive abilities on the model of knockout mice. BMC Neurosci 2013; 14:53. [PMID: 23672583 PMCID: PMC3659041 DOI: 10.1186/1471-2202-14-53] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/07/2013] [Indexed: 11/10/2022] Open
Abstract
Background Gamma-synuclein is a member of the synuclein family of cytoplasmic, predominantly neuron-specific proteins. Despite numerous evidences for the importance of gamma-synuclein in the control of monoamine homeostasis, cytoskeleton reorganization and chaperone activity, its role in the regulation of cognitive behavior still remain unknown. Our previous study revealed that gamma-synuclein knockout mice are characterized by high habituation scores. Since a number of processes including spatial memory of the environment may affect habituation, in the present study we have carried out behavioral evaluation of spatial and working memory in gamma-synuclein knockout mice. Results Inactivation of gamma-synuclein gene led to the improvement of working memory in mice as revealed by passive and active avoidance tests. At the same time behavioral tests, designed to assess spatial learning and memory (Morris water maze and Object location tests), showed no differences between gamma-synuclein knockouts and wild type mice. Conclusions These findings indicate that young mice with targeted inactivation of gamma-synuclein gene have improved working memory, but not spatial learning and memory. Our results suggest that gamma-synuclein is directly involved in the regulation of cognitive functions.
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Affiliation(s)
- Viktor S Kokhan
- Institute of Physiologically Active Compounds RAS, Chernogolovka, Russia.
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Ninkina N, Peters OM, Connor-Robson N, Lytkina O, Sharfeddin E, Buchman VL. Contrasting effects of α-synuclein and γ-synuclein on the phenotype of cysteine string protein α (CSPα) null mutant mice suggest distinct function of these proteins in neuronal synapses. J Biol Chem 2012; 287:44471-7. [PMID: 23129765 PMCID: PMC3531760 DOI: 10.1074/jbc.m112.422402] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In neuronal synapses, neurotransmitter-loaded vesicles fuse with presynaptic plasma membrane in a complex sequence of tightly regulated events. The assembly of specialized SNARE complexes plays a pivotal role in this process. The function of the chaperone cysteine string protein α (CSPα) is important for synaptic SNARE complex formation, and mice lacking this protein develop severe synaptic dysfunction and neurodegeneration that lead to their death within 3 months after birth. Another presynaptic protein, α-synuclein, also potentiates SNARE complex formation, and its overexpression rescues the phenotype of CSPα null mutant mice, although these two proteins use different mechanisms to achieve this effect. α-Synuclein is a member of a family of three related proteins whose structural similarity suggests functional redundancy. Here, we assessed whether γ-synuclein shares the ability of α-synuclein to bind synaptic vesicles and ameliorate neurodegeneration caused by CSPα deficiency in vivo. Although the N-terminal lipid-binding domains of the two synucleins showed similar affinity for purified synaptic vesicles, the C-terminal domain of γ-synuclein was not able to interact with synaptobrevin-2/VAMP2. Consequently, overexpression of γ-synuclein did not have any noticeable effect on the phenotype of CSPα null mutant mice. Our data suggest that the functions of α- and γ-synucleins in presynaptic terminals are not fully redundant.
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Affiliation(s)
- Natalia Ninkina
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
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