1
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Smith ME, Bazinet RP. Unraveling brain palmitic acid: Origin, levels and metabolic fate. Prog Lipid Res 2024:101300. [PMID: 39222711 DOI: 10.1016/j.plipres.2024.101300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 08/26/2024] [Accepted: 08/28/2024] [Indexed: 09/04/2024]
Abstract
In the human brain, palmitic acid (16:0; PAM) comprises nearly half of total brain saturates and has been identified as the third most abundant fatty acid overall. Brain PAM supports the structure of membrane phospholipids, provides energy, and regulates protein stability. Sources underlying the origin of brain PAM are both diet and endogenous synthesis via de novo lipogenesis (DNL), primarily from glucose. However, studies investigating the origin of brain PAM are limited to tracer studies utilizing labelled (14C/11C/3H/2H) PAM, and results vary based on the model and tracer used. Nevertheless, there is evidence PAM is synthesized locally in the brain, in addition to obtained directly from the diet. Herein, we provide an overview of brain PAM origin, entry to the brain, metabolic fate, and factors influencing brain PAM kinetics and levels, the latter in the context of age, as well as neurological diseases and psychiatric disorders. Additionally, we briefly summarize the role of PAM in signaling at the level of the brain. We add to the literature a rudimentary summary on brain PAM metabolism.
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Affiliation(s)
- Mackenzie E Smith
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Richard P Bazinet
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.
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2
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Kawade N, Yamanaka K. Novel insights into brain lipid metabolism in Alzheimer's disease: Oligodendrocytes and white matter abnormalities. FEBS Open Bio 2024; 14:194-216. [PMID: 37330425 PMCID: PMC10839347 DOI: 10.1002/2211-5463.13661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/07/2023] [Accepted: 06/14/2023] [Indexed: 06/19/2023] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia. A genome-wide association study has shown that several AD risk genes are involved in lipid metabolism. Additionally, epidemiological studies have indicated that the levels of several lipid species are altered in the AD brain. Therefore, lipid metabolism is likely changed in the AD brain, and these alterations might be associated with an exacerbation of AD pathology. Oligodendrocytes are glial cells that produce the myelin sheath, which is a lipid-rich insulator. Dysfunctions of the myelin sheath have been linked to white matter abnormalities observed in the AD brain. Here, we review the lipid composition and metabolism in the brain and myelin and the association between lipidic alterations and AD pathology. We also present the abnormalities in oligodendrocyte lineage cells and white matter observed in AD. Additionally, we discuss metabolic disorders, including obesity, as AD risk factors and the effects of obesity and dietary intake of lipids on the brain.
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Affiliation(s)
- Noe Kawade
- Department of Neuroscience and Pathobiology, Research Institute of Environmental MedicineNagoya UniversityJapan
- Department of Neuroscience and Pathobiology, Nagoya University Graduate School of MedicineNagoya UniversityJapan
| | - Koji Yamanaka
- Department of Neuroscience and Pathobiology, Research Institute of Environmental MedicineNagoya UniversityJapan
- Department of Neuroscience and Pathobiology, Nagoya University Graduate School of MedicineNagoya UniversityJapan
- Institute for Glyco‐core Research (iGCORE)Nagoya UniversityJapan
- Center for One Medicine Innovative Translational Research (COMIT)Nagoya UniversityJapan
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3
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Castor K, Dawlaty J, Arakaki X, Gross N, Woldeamanuel YW, Harrington MG, Cowan RP, Fonteh AN. Plasma Lipolysis and Changes in Plasma and Cerebrospinal Fluid Signaling Lipids Reveal Abnormal Lipid Metabolism in Chronic Migraine. Front Mol Neurosci 2021; 14:691733. [PMID: 34531722 PMCID: PMC8438335 DOI: 10.3389/fnmol.2021.691733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
Background Lipids are a primary storage form of energy and the source of inflammatory and pain signaling molecules, yet knowledge of their importance in chronic migraine (CM) pathology is incomplete. We aim to determine if plasma and cerebrospinal fluid (CSF) lipid metabolism are associated with CM pathology. Methods We obtained plasma and CSF from healthy controls (CT, n = 10) or CM subjects (n = 15) diagnosed using the International Headache Society criteria. We measured unesterified fatty acid (UFA) and esterified fatty acids (EFAs) using gas chromatography-mass spectrometry. Glycerophospholipids (GP) and sphingolipid (SP) levels were determined using LC-MS/MS, and phospholipase A2 (PLA2) activity was determined using fluorescent substrates. Results Unesterified fatty acid levels were significantly higher in CM plasma but not in CSF. Unesterified levels of five saturated fatty acids (SAFAs), eight monounsaturated fatty acids (MUFAs), five ω-3 polyunsaturated fatty acids (PUFAs), and five ω-6 PUFAs are higher in CM plasma. Esterified levels of three SAFAs, eight MUFAs, five ω-3 PUFAs, and three ω-6 PUFAs, are higher in CM plasma. The ratios C20:4n-6/homo-γ-C20:3n-6 representative of delta-5-desaturases (D5D) and the elongase ratio are lower in esterified and unesterified CM plasma, respectively. In the CSF, the esterified D5D index is lower in CM. While PLA2 activity was similar, the plasma UFA to EFA ratio is higher in CM. Of all plasma GP/SPs detected, only ceramide levels are lower (p = 0.0003) in CM (0.26 ± 0.07%) compared to CT (0.48 ± 0.06%). The GP/SP proportion of platelet-activating factor (PAF) is significantly lower in CM CSF. Conclusions Plasma and CSF lipid changes are consistent with abnormal lipid metabolism in CM. Since plasma UFAs correspond to diet or adipose tissue levels, higher plasma fatty acids and UFA/EFA ratios suggest enhanced adipose lipolysis in CM. Differences in plasma and CSF desaturases and elongases suggest altered lipid metabolism in CM. A lower plasma ceramide level suggests reduced de novo synthesis or reduced sphingomyelin hydrolysis. Changes in CSF PAF suggest differences in brain lipid signaling pathways in CM. Together, this pilot study shows lipid metabolic abnormality in CM corresponding to altered energy homeostasis. We propose that controlling plasma lipolysis, desaturases, elongases, and lipid signaling pathways may relieve CM symptoms.
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Affiliation(s)
- Katherine Castor
- Department of Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States
| | - Jessica Dawlaty
- Department of Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States
| | - Xianghong Arakaki
- Department of Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States.,Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Noah Gross
- Department of Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States
| | | | - Michael G Harrington
- Department of Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States.,Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.,Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, United States
| | - Robert P Cowan
- Pain Center, Department of Neurology, Stanford University, Stanford, CA, United States
| | - Alfred N Fonteh
- Department of Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States.,Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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4
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Poitelon Y, Kopec AM, Belin S. Myelin Fat Facts: An Overview of Lipids and Fatty Acid Metabolism. Cells 2020; 9:cells9040812. [PMID: 32230947 PMCID: PMC7226731 DOI: 10.3390/cells9040812] [Citation(s) in RCA: 148] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 12/11/2022] Open
Abstract
Myelin is critical for the proper function of the nervous system and one of the most complex cell–cell interactions of the body. Myelination allows for the rapid conduction of action potentials along axonal fibers and provides physical and trophic support to neurons. Myelin contains a high content of lipids, and the formation of the myelin sheath requires high levels of fatty acid and lipid synthesis, together with uptake of extracellular fatty acids. Recent studies have further advanced our understanding of the metabolism and functions of myelin fatty acids and lipids. In this review, we present an overview of the basic biology of myelin lipids and recent insights on the regulation of fatty acid metabolism and functions in myelinating cells. In addition, this review may serve to provide a foundation for future research characterizing the role of fatty acids and lipids in myelin biology and metabolic disorders affecting the central and peripheral nervous system.
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5
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Siems SB, Jahn O, Eichel MA, Kannaiyan N, Wu LMN, Sherman DL, Kusch K, Hesse D, Jung RB, Fledrich R, Sereda MW, Rossner MJ, Brophy PJ, Werner HB. Proteome profile of peripheral myelin in healthy mice and in a neuropathy model. eLife 2020; 9:e51406. [PMID: 32130108 PMCID: PMC7056269 DOI: 10.7554/elife.51406] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/19/2020] [Indexed: 02/07/2023] Open
Abstract
Proteome and transcriptome analyses aim at comprehending the molecular profiles of the brain, its cell-types and subcellular compartments including myelin. Despite the relevance of the peripheral nervous system for normal sensory and motor capabilities, analogous approaches to peripheral nerves and peripheral myelin have fallen behind evolving technical standards. Here we assess the peripheral myelin proteome by gel-free, label-free mass-spectrometry for deep quantitative coverage. Integration with RNA-Sequencing-based developmental mRNA-abundance profiles and neuropathy disease genes illustrates the utility of this resource. Notably, the periaxin-deficient mouse model of the neuropathy Charcot-Marie-Tooth 4F displays a highly pathological myelin proteome profile, exemplified by the discovery of reduced levels of the monocarboxylate transporter MCT1/SLC16A1 as a novel facet of the neuropathology. This work provides the most comprehensive proteome resource thus far to approach development, function and pathology of peripheral myelin, and a straightforward, accurate and sensitive workflow to address myelin diversity in health and disease.
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Affiliation(s)
- Sophie B Siems
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Maria A Eichel
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Nirmal Kannaiyan
- Department of Psychiatry and Psychotherapy, University Hospital, LMU MunichMunichGermany
| | - Lai Man N Wu
- Centre for Discovery Brain Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Diane L Sherman
- Centre for Discovery Brain Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Dörte Hesse
- Proteomics Group, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Robert Fledrich
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
- Institute of Anatomy, University of LeipzigLeipzigGermany
| | - Michael W Sereda
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
- Department of Clinical Neurophysiology, University Medical CenterGöttingenGermany
| | - Moritz J Rossner
- Department of Psychiatry and Psychotherapy, University Hospital, LMU MunichMunichGermany
| | - Peter J Brophy
- Centre for Discovery Brain Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
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6
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Sessions-Bresnahan DR, Heuberger AL, Carnevale EM. Obesity in mares promotes uterine inflammation and alters embryo lipid fingerprints and homeostasis. Biol Reprod 2019; 99:761-772. [PMID: 29741587 DOI: 10.1093/biolre/ioy107] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 05/04/2018] [Indexed: 02/06/2023] Open
Abstract
Maternal body composition can be an important determinant for development of obesity and metabolic syndrome in adult offspring. Obesity-related outcomes in offspring may include epigenetic alterations; however, mechanisms of fetal programming remain to be fully elucidated. This study was conducted to determine the impact of maternal obesity in the absence of a high fat diet on equine endometrium and preimplantation embryos. Embryos were collected from normal and obese mares at 8 and 16 days and a uterine biopsy at 16 days (0 day = ovulation). With the exception of 8 day embryos, each sample was divided into two pieces. One piece was analyzed for gene expression markers related to carbohydrate metabolism, lipid homeostasis, inflammation, endoplasmic reticulum stress, oxidative stress, mitochondrial stress, and components of the insulin-like growth factor (IGF) system. The second piece was analyzed for lipid content using matrix-assisted laser desorption/ionization mass spectrometry. Obese mares had elevated concentrations of insulin, leptin, and total cholesterol, and they tended to have increased triglycerides and decreased insulin sensitivity. Embryos from obese mares had altered transcript abundance in genes for inflammation and lipid homeostasis, as well as endoplasmic reticulum, oxidative and mitochondrial stress and altered lipid fingerprints. Endometrium from obese mares had increased expression of inflammatory cytokines, lipid homeostasis regulation, mitochondrial stress, and the IGF2 system. This study demonstrates that increased adiposity in mares alters the uterine environment, transcript abundance of genes for cellular functions, and lipid profiles of embryos. These alterations could affect prenatal programming, with potential long-term effects in offspring.
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Affiliation(s)
- Dawn R Sessions-Bresnahan
- Department of Animal Science, Mount Berry, Georgia, USA.,Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Adam L Heuberger
- Horticulture and Landscape Architecture, Colorado State University, Fort Collins, Colorado, USA.,Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, Colorado, USA
| | - Elaine M Carnevale
- Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
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7
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Xie YJ, Zhou L, Wang Y, Jiang NW, Cao S, Shao CY, Wang XT, Li XY, Shen Y, Zhou L. Leucine-Rich Glioma Inactivated 1 Promotes Oligodendrocyte Differentiation and Myelination via TSC-mTOR Signaling. Front Mol Neurosci 2018; 11:231. [PMID: 30034322 PMCID: PMC6043672 DOI: 10.3389/fnmol.2018.00231] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 06/12/2018] [Indexed: 12/26/2022] Open
Abstract
Leucine-rich glioma inactivated 1 (Lgi1), a putative tumor suppressor, is tightly associated with autosomal dominant lateral temporal lobe epilepsy (ADLTE). It has been shown that Lgi1 regulates the myelination of Schwann cells in the peripheral nervous system (PNS). However, the function and underlying mechanisms for Lgi1 regulation of oligodendrocyte differentiation and myelination in the central nervous system (CNS) remain elusive. In addition, whether Lgi1 is required for myelin maintenance is unknown. Here, we show that Lgi1 is necessary and sufficient for the differentiation of oligodendrocyte precursor cells and is also required for the maintenance of myelinated fibers. The hypomyelination in Lgi1-/- mice attributes to the inhibition of the biosynthesis of lipids and proteins in oligodendrocytes (OLs). Moreover, we found that Lgi1 deficiency leads to a decrease in expression of tuberous sclerosis complex 1 (TSC1) and activates mammalian target of rapamycin signaling. Together, the present work establishes that Lgi1 is a regulator of oligodendrocyte development and myelination in CNS.
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Affiliation(s)
- Ya-Jun Xie
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Lin Zhou
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Yin Wang
- Laboratory of Craniocerebral Diseases of Ningxia Hui Autonomous Region, Ningxia Medical UniversityYinchuan, China
| | - Nan-Wei Jiang
- Ningbo Key Laboratory of Behavioral Neuroscience, Department of Physiology and Pharmacology, Ningbo University School of MedicineNingbo, China
| | - Shenglong Cao
- Department of Neurosurgery, Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou, China
| | - Chong-Yu Shao
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Xin-Tai Wang
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Xiang-Yao Li
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Ying Shen
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
| | - Liang Zhou
- Key Laboratory of Medical Neurobiology of Ministry of Health, Department of Neurobiology, Zhejiang University School of MedicineHangzhou, China
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8
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Montani L, Pereira JA, Norrmén C, Pohl HBF, Tinelli E, Trötzmüller M, Figlia G, Dimas P, von Niederhäusern B, Schwager R, Jessberger S, Semenkovich CF, Köfeler HC, Suter U. De novo fatty acid synthesis by Schwann cells is essential for peripheral nervous system myelination. J Cell Biol 2018; 217:1353-1368. [PMID: 29434029 PMCID: PMC5881495 DOI: 10.1083/jcb.201706010] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 12/20/2017] [Accepted: 01/22/2018] [Indexed: 01/26/2023] Open
Abstract
Montani et al. reveal that de novo fatty acid synthesis by Schwann cells, mediated by fatty acid synthase, contributes fundamentally to driving myelination in the peripheral nervous system. They identify lipogenic activation of the PPARγ transcriptional network as a putatively involved functional mechanism. Myelination calls for a remarkable surge in cell metabolism to facilitate lipid and membrane production. Endogenous fatty acid (FA) synthesis represents a potentially critical process in myelinating glia. Using genetically modified mice, we show that Schwann cell (SC) intrinsic activity of the enzyme essential for de novo FA synthesis, fatty acid synthase (FASN), is crucial for precise lipid composition of peripheral nerves and fundamental for the correct onset of myelination and proper myelin growth. Upon FASN depletion in SCs, epineurial adipocytes undergo lipolysis, suggestive of a compensatory role. Mechanistically, we found that a lack of FASN in SCs leads to an impairment of the peroxisome proliferator-activated receptor (PPAR) γ–regulated transcriptional program. In agreement, defects in myelination of FASN-deficient SCs could be ameliorated by treatment with the PPARγ agonist rosiglitazone ex vivo and in vivo. Our results reveal that FASN-driven de novo FA synthesis in SCs is mandatory for myelination and identify lipogenic activation of the PPARγ transcriptional network as a putative downstream functional mediator.
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Affiliation(s)
- Laura Montani
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
| | - Jorge A Pereira
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
| | - Camilla Norrmén
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
| | - Hartmut B F Pohl
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
| | - Elisa Tinelli
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
| | - Martin Trötzmüller
- Lipidomics Center for Medical Research, Medical University, Graz, Austria
| | - Gianluca Figlia
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
| | - Penelope Dimas
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
| | - Belinda von Niederhäusern
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
| | - Rachel Schwager
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
| | | | - Clay F Semenkovich
- Division of Endocrinology, Metabolism and Lipid Research, Washington University Medical School, St. Louis, MO
| | - Harald C Köfeler
- Lipidomics Center for Medical Research, Medical University, Graz, Austria
| | - Ueli Suter
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, Switzerland
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9
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Quantitative and integrative proteome analysis of peripheral nerve myelin identifies novel myelin proteins and candidate neuropathy loci. J Neurosci 2012; 31:16369-86. [PMID: 22072688 DOI: 10.1523/jneurosci.4016-11.2011] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Peripheral nerve myelin facilitates rapid impulse conduction and normal motor and sensory functions. Many aspects of myelin biogenesis, glia-axonal interactions, and nerve homeostasis are poorly understood at the molecular level. We therefore hypothesized that only a fraction of all relevant myelin proteins has been identified so far. Combining gel-based and gel-free proteomic approaches, we identified 545 proteins in purified mouse sciatic nerve myelin, including 36 previously known myelin constituents. By mass spectrometric quantification, the predominant P0, periaxin, and myelin basic protein constitute 21, 16, and 8% of the total myelin protein, respectively, suggesting that their relative abundance was previously misestimated due to technical limitations regarding protein separation and visualization. Focusing on tetraspan-transmembrane proteins, we validated novel myelin constituents using immuno-based methods. Bioinformatic comparison with mRNA-abundance profiles allowed the categorization in functional groups coregulated during myelin biogenesis and maturation. By differential myelin proteome analysis, we found that the abundance of septin 9, the protein affected in hereditary neuralgic amyotrophy, is strongly increased in a novel mouse model of demyelinating neuropathy caused by the loss of prion protein. Finally, the systematic comparison of our compendium with the positions of human disease loci allowed us to identify several candidate genes for hereditary demyelinating neuropathies. These results illustrate how the integration of unbiased proteome, transcriptome, and genome data can contribute to a molecular dissection of the biogenesis, cell biology, metabolism, and pathology of myelin.
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10
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Saito M, Chakraborty G, Mao RF, Vadasz C, Saito M. Developmental profiles of lipogenic enzymes and their regulators in the neonatal mouse brain. Neurochem Res 2009; 34:1945-54. [PMID: 19418221 DOI: 10.1007/s11064-009-9975-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2009] [Accepted: 04/15/2009] [Indexed: 12/01/2022]
Abstract
It has been shown that lipogenic enzymes, such as fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC), are highly expressed in the rodent brain during the early neonatal period and decline thereafter. However, cellular localization of these enzymes is unknown. Presently, we examined developmental changes in the levels and cellular localization of FAS and ACC, and their putative regulators, sterol-regulatory element-binding protein (SREBP)-1 and AMP-activated protein kinase (AMPK) in the mouse brain. Levels of these proteins including phosphorylated forms of ACC and AMPK decreased between postnatal day 4 (P4) and P19. Immunohistochemical studies indicated that FAS, ACC, AMPK, and SREBP-1 were expressed in neurons at P7, while FAS was found mostly in cells of oligodendrocyte lineage at P19. These studies suggest that neurons in the early neonatal brain are involved in do novo fatty acid synthesis.
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Affiliation(s)
- Mariko Saito
- Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
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11
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12
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Marseille-Tremblay C, Ethier-Chiasson M, Forest JC, Giguère Y, Masse A, Mounier C, Lafond J. Impact of maternal circulating cholesterol and gestational diabetes mellitus on lipid metabolism in human term placenta. Mol Reprod Dev 2008; 75:1054-62. [DOI: 10.1002/mrd.20842] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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13
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Liang G, Cline GW, Macica CM. IGF-1 stimulates de novo fatty acid biosynthesis by Schwann cells during myelination. Glia 2007; 55:632-41. [PMID: 17299765 DOI: 10.1002/glia.20496] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Schwann cell (SC) differentiation to the myelinating phenotype is characterized by the elaboration of a lipid-rich membrane and the expression of myelin-specific proteins. Insulin-like growth factor-1 (IGF-1) has been identified as a growth factor that stimulates the early events of myelination in SCs that signals via the PI3K/Akt pathway. Given the role of IGF-1 in promoting myelination, we performed studies to determine if the fatty acid biosynthetic pathway was a target of IGF-1 signaling in the formation of myelin membrane in dorsal root ganglion neuron/Schwann cell (DRG/SC) cocultures. We report that the fatty acid profile of lipid extracts of cocultures treated with IGF-1 match that reported for native myelin membrane by electrospray mass spectroscopy analysis. We also demonstrate de novo fatty acid biosynthesis in response to IGF-1 treatment in DRG/SC cocultures metabolically labeled with (13)C-acetate as a carbon source for fatty acid synthesis. Consistent with this finding, Western blot analysis of lysates from both cocultures and purified SCs reveal that IGF-1 stimulates two key fatty acid synthesizing enzymes. Additionally, we show that stimulation of fatty acid synthesizing enzymes is mediated by the PI3K/Akt signaling pathway. We also show that the fatty acid synthesizing enzymes and associated signaling pathways are elevated during the period of myelin membrane formation in sciatic nerve. Collectively, these findings demonstrate that IGF-1 plays an important regulatory function during myelin membrane formation.
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Affiliation(s)
- Guoying Liang
- Division of Endocrinology, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8020, USA
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14
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Zhao W, Kridel S, Thorburn A, Kooshki M, Little J, Hebbar S, Robbins M. Fatty acid synthase: a novel target for antiglioma therapy. Br J Cancer 2006; 95:869-78. [PMID: 16969344 PMCID: PMC2360524 DOI: 10.1038/sj.bjc.6603350] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
High levels of fatty acid synthase (FAS) expression have been observed in several cancers, including breast, prostate, colon and lung carcinoma, compared with their respective normal tissue. We present data that show high levels of FAS protein in human and rat glioma cell lines and human glioma tissue samples, as compared to normal rat astrocytes and normal human brain. Incubating glioma cells with the FAS inhibitor cerulenin decreased endogenous fatty acid synthesis by approximately 50%. Cell cycle analysis demonstrated a time- and dose-dependent increase in S-phase cell arrest following cerulenin treatment for 24 h. Further, treatment with cerulenin resulted in time- and dose-dependent decreases in glioma cell viability, as well as reduced clonogenic survival. Increased apoptotic cell death and PARP cleavage were observed in U251 and SNB-19 cells treated with cerulenin, which was independent of the death receptor pathway. Overexpressing Bcl-2 inhibited cerulenin-mediated cell death. In contrast, primary rat astrocytes appeared unaffected. Finally, RNAi-mediated knockdown of FAS leading to reduced FAS enzymatic activity was associated with decreased glioma cell viability. These findings suggest that FAS might be a novel target for antiglioma therapy.
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Affiliation(s)
- W Zhao
- Department of Radiation Oncology, Brain Tumor Center of Excellence, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
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Landree LE, Hanlon AL, Strong DW, Rumbaugh G, Miller IM, Thupari JN, Connolly EC, Huganir RL, Richardson C, Witters LA, Kuhajda FP, Ronnett GV. C75, a fatty acid synthase inhibitor, modulates AMP-activated protein kinase to alter neuronal energy metabolism. J Biol Chem 2003; 279:3817-27. [PMID: 14615481 DOI: 10.1074/jbc.m310991200] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
C75, a synthetic inhibitor of fatty acid synthase (FAS), is hypothesized to alter the metabolism of neurons in the hypothalamus that regulate feeding behavior to contribute to the decreased food intake and profound weight loss seen with C75 treatment. In the present study, we characterize the suitability of primary cultures of cortical neurons for studies designed to investigate the consequences of C75 treatment and the alteration of fatty acid metabolism in neurons. We demonstrate that in primary cortical neurons, C75 inhibits FAS activity and stimulates carnitine palmitoyltransferase-1 (CPT-1), consistent with its effects in peripheral tissues. C75 alters neuronal ATP levels and AMP-activated protein kinase (AMPK) activity. Neuronal ATP levels are affected in a biphasic manner with C75 treatment, decreasing initially, followed by a prolonged increase above control levels. Cerulenin, a FAS inhibitor, causes a similar biphasic change in ATP levels, although levels do not exceed control. C75 and cerulenin modulate AMPK phosphorylation and activity. TOFA, an inhibitor of acetyl-CoA carboxylase, increases ATP levels, but does not affect AMPK activity. Several downstream pathways are affected by C75 treatment, including glucose metabolism and acetyl-CoA carboxylase (ACC) phosphorylation. These data demonstrate that C75 modulates the levels of energy intermediates, thus, affecting the energy sensor AMPK. Similar effects in hypothalamic neurons could form the basis for the effects of C75 on feeding behavior.
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Affiliation(s)
- Leslie E Landree
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Salles J, Sargueil F, Knoll-Gellida A, Witters LA, Cassagne C, Garbay B. Acetyl-CoA carboxylase and SREBP expression during peripheral nervous system myelination. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1631:229-38. [PMID: 12668174 DOI: 10.1016/s1388-1981(03)00041-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The expression of acetyl-CoA carboxylase (ACC) in mouse peripheral nervous system (PNS) was investigated. Both ACC 265 and ACC 280 isoforms were expressed in the sciatic nerve, although ACC 265 was predominant. ACC 265 transcripts originating from promoters P1 and P2 could be detected in the developing nerve, as well as the two splice products, which are characterized by the presence or the absence of a 24-base sequence before the codon serine-1200. The mRNA levels for ACC 265 parallel those of other lipogenic genes whose expression is linked to the myelination process. In addition, ACC 265 mRNA and protein levels in the nerves of the trembler mutant, which is a mouse model of PNS dysmyelination, represented around 30% of the normal values. The expression of the sterol regulatory element-binding proteins (SREBPs) was also studied. SREBP 1 mRNAs were expressed at a constant level during nerve development, and their quantities were normal in trembler. On the contrary, SREBP 2 mRNA quantities varied during the myelination period similarly to the lipogenic gene mRNAs, and the levels measured in trembler represented only 10% of the normal values. Taken together, these results suggest that the coordinate expression of several lipogenic genes, which occurs during PNS myelination, could possibly be regulated by SREBP 2.
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Affiliation(s)
- Jérôme Salles
- Laboratoire de Biogenèse Membranaire, UMR-CNRS 5544, Université Victor Segalen Bordeaux 2, Bordeaux, France
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