201
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Gondim KC, Atella GC, Pontes EG, Majerowicz D. Lipid metabolism in insect disease vectors. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 101:108-123. [PMID: 30171905 DOI: 10.1016/j.ibmb.2018.08.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 08/17/2018] [Accepted: 08/26/2018] [Indexed: 06/08/2023]
Abstract
More than a third of the world population is at constant risk of contracting some insect-transmitted disease, such as Dengue fever, Zika virus disease, malaria, Chagas' disease, African trypanosomiasis, and others. Independent of the life cycle of the pathogen causing the disease, the insect vector hematophagous habit is a common and crucial trait for the transmission of all these diseases. This lifestyle is unique, as hematophagous insects feed on blood, a diet that is rich in protein but relatively poor in lipids and carbohydrates, in huge amounts and low frequency. Another unique feature of these insects is that blood meal triggers essential metabolic processes, as molting and oogenesis and, in this way, regulates the expression of various genes that are involved in these events. In this paper, we review current knowledge of the physiology and biochemistry of lipid metabolism in insect disease vectors, comparing with classical models whenever possible. We address lipid digestion and absorption, hemolymphatic transport, and lipid storage by the fat body and ovary. In this context, both de novo fatty acid and triacylglycerol synthesis are discussed, including the related fatty acid activation process and the intracellular lipid binding proteins. As lipids are stored in order to be mobilized later on, e.g. for flight activity or survivorship, lipolysis and β-oxidation are also considered. All these events need to be finely regulated, and the role of hormones in this control is summarized. Finally, we also review information about infection, when vector insect physiology is affected, and there is a crosstalk between its immune system and lipid metabolism. There is not abundant information about lipid metabolism in vector insects, and significant current gaps in the field are indicated, as well as questions to be answered in the future.
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Affiliation(s)
- Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Georgia C Atella
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Emerson G Pontes
- Departamento de Bioquímica, Instituto de Química, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil
| | - David Majerowicz
- Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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202
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Bakshi I, Brown SHJ, Brandon AE, Suryana E, Mitchell TW, Turner N, Cooney GJ. Increasing Acyl CoA thioesterase activity alters phospholipid profile without effect on insulin action in skeletal muscle of rats. Sci Rep 2018; 8:13967. [PMID: 30228369 PMCID: PMC6143561 DOI: 10.1038/s41598-018-32354-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 05/18/2018] [Indexed: 12/25/2022] Open
Abstract
Increased lipid metabolism in muscle is associated with insulin resistance and therefore, many strategies have been employed to alter fatty acid metabolism and study the impact on insulin action. Metabolism of fatty acid requires activation to fatty acyl CoA by Acyl CoA synthases (ACSL) and fatty acyl CoA can be hydrolysed by Acyl CoA thioesterases (Acot). Thioesterase activity is low in muscle, so we overexpressed Acot7 in muscle of chow and high-fat diet (HFD) rats and investigated effects on insulin action. Acot7 overexpression modified specific phosphatidylcholine and phosphatidylethanolamine species in tibialis muscle of chow rats to levels similar to those observed in control HFD muscle. The changes in phospholipid species did not alter glucose uptake in tibialis muscle under hyperinsulinaemic/euglycaemic clamped conditions. Acot7 overexpression in white extensor digitorum longus (EDL) muscle increased complete fatty acid oxidation ex-vivo but was not associated with any changes in glucose uptake in-vivo, however overexpression of Acot7 in red EDL reduced insulin-stimulated glucose uptake in-vivo which correlated with increased incomplete fatty acid oxidation ex-vivo. In summary, although overexpression of Acot7 in muscle altered some aspects of lipid profile and metabolism in muscle, this had no major effect on insulin-stimulated glucose uptake.
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Affiliation(s)
- Ishita Bakshi
- Diabetes and Metabolism Division, Garvan Institute, Sydney, Australia
| | - Simon H J Brown
- School of Biological Sciences, University of Wollongong, Wollongong, Australia
| | - Amanda E Brandon
- Diabetes and Metabolism Division, Garvan Institute, Sydney, Australia.,Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia
| | - Eurwin Suryana
- Diabetes and Metabolism Division, Garvan Institute, Sydney, Australia
| | - Todd W Mitchell
- School of Biological Sciences, University of Wollongong, Wollongong, Australia
| | - Nigel Turner
- Department of Pharmacology, School of Medical Sciences, UNSW Sydney, Sydney, Australia
| | - Gregory J Cooney
- Diabetes and Metabolism Division, Garvan Institute, Sydney, Australia. .,Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, Australia.
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203
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Signature molecules expressed differentially in a liver disease stage-specific manner by HIV-1 and HCV co-infection. PLoS One 2018; 13:e0202524. [PMID: 30138348 PMCID: PMC6107166 DOI: 10.1371/journal.pone.0202524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 08/03/2018] [Indexed: 12/20/2022] Open
Abstract
To elucidate HIV-1 co-infection-induced acceleration of HCV liver disease and identify stage-specific molecular signatures, we applied a new high-resolution molecular screen, the Affymetrix GeneChip Human Transcriptome Array (HTA2.0), to HCV-mono- and HIV/HCV-co-infected liver specimens from subjects with early and advanced disease. Out of 67,528 well-annotated genes, we have analyzed the functional and statistical significance of 75 and 28 genes expressed differentially between early and advanced stages of HCV mono- and HIV/HCV co-infected patient liver samples, respectively. We also evaluated the expression of 25 and 17 genes between early stages of mono- and co-infected liver tissues and between advanced stages of mono- and co-infected patient's samples, respectively. Based on our analysis of fold-change in gene expression as a function of disease stage (i.e., early vs. advanced), coupled with consideration of the known relevant functions of these genes, we focused on four candidate genes, ACSL4, GNMT, IFI27, and miR122, which are expressed stage-specifically in HCV mono- and HIV-1/HCV co-infective liver disease and are known to play a pivotal role in regulating HCV-mediated hepatocellular carcinoma (HCC). Our qRT-PCR analysis of the four genes in patient liver specimens supported the microarray data. Protein products of each gene were detected in the endoplasmic reticulum (ER) where HCV replication takes place, and the genes' expression significantly altered replicability of HCV in the subgenomic replicon harboring regulatory genes of the JFH1 strain of HCV in Huh7.5.1. With respect to three well-known transferrable HIV-1 viral elements-Env, Nef, and Tat-Nef uniquely augmented replicon expression, while Tat, but not the others, substantially modulated expression of the candidate genes in hepatocytic cells. Combinatorial expression of these cellular and viral genes in the replicon cells further altered replicon expression. Taken together, these results showed that HIV-1 viral proteins can exacerbate liver pathology in the co-infected patients by disparate molecular mechanisms-directly or indirectly dysregulating HCV replication, even if lack of association of HCV load and end-stage liver disease in hemophilic patients were reported, and modulating expression of hepatocellular genes critical for disease progression. These findings also provide major insights into development of stage-specific hepatocellular biomarkers for improved diagnosis and prognosis of HCV-mediated liver disease.
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204
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Asghar R, Chondronikola M, Dillon EL, Durham WJ, Porter C, Wu Z, Camacho-Hughes M, Andersen CR, Spratt H, Volpi E, Sheffield-Moore M, Sidossis L, Wolfe RR, Abate N, Tuvdendorj DR. Quantification of muscle triglyceride synthesis rate requires an adjustment for total triglyceride content. J Lipid Res 2018; 59:2018-2024. [PMID: 30131344 DOI: 10.1194/jlr.d082321] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 07/18/2018] [Indexed: 01/06/2023] Open
Abstract
Intramyocellular triglyceride (imTG) in skeletal muscle plays a significant role in metabolic health, and an infusion of [13C16]palmitate can be used to quantitate the in vivo fractional synthesis rate (FSR) and absolute synthesis rate (ASR) of imTGs. However, the extramyocellular TG (emTG) pool, unless precisely excised, contaminates the imTG pool, diluting the imTG-bound tracer enrichment and leading to underestimation of FSR. Because of the difficulty of excising the emTGs precisely, it would be advantageous to be able to calculate the imTG synthesis rate without dissecting the emTGs from each sample. Here, we tested the hypothesis that the ASR of total TGs (tTGs), a combination of imTGs and emTGs, calculated as "FSR × tTG pool," reasonably represents the imTG synthesis. Muscle lipid parameters were measured in nine healthy women at 90 and 170 min after the start of [13C16]palmitate infusion. While the measurements of tTG content, enrichment, and FSR did not correlate (P > 0.05), those of the tTG ASR were significantly correlated (r = 0.947, P < 0.05). These results demonstrate that when imTGs and emTGs are pooled, the resulting underestimation of imTG FSR is balanced by the overestimation of the imTG content. We conclude that imTG metabolism is reflected by the measurement of the tTG ASR.
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Affiliation(s)
- Rabia Asghar
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX
| | - Maria Chondronikola
- Departments of Surgery, University of Texas Medical Branch, Galveston, TX.,Metabolism Unit, Shriners Hospitals for Children, Galveston, TX
| | - Edgar L Dillon
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX
| | - William J Durham
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX
| | - Craig Porter
- Departments of Surgery, University of Texas Medical Branch, Galveston, TX.,Metabolism Unit, Shriners Hospitals for Children, Galveston, TX
| | | | - Maria Camacho-Hughes
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX
| | - Clark R Andersen
- Departments of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX
| | - Heidi Spratt
- Departments of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX
| | - Elena Volpi
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX
| | | | - Labros Sidossis
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX.,Metabolism Unit, Shriners Hospitals for Children, Galveston, TX
| | - Robert R Wolfe
- Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Nicola Abate
- Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX
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205
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Giardia lamblia : Identification of peroxisomal-like proteins. Exp Parasitol 2018; 191:36-43. [DOI: 10.1016/j.exppara.2018.06.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 06/04/2018] [Accepted: 06/14/2018] [Indexed: 11/18/2022]
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206
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Tang Y, Zhou J, Hooi SC, Jiang YM, Lu GD. Fatty acid activation in carcinogenesis and cancer development: Essential roles of long-chain acyl-CoA synthetases. Oncol Lett 2018; 16:1390-1396. [PMID: 30008815 DOI: 10.3892/ol.2018.8843] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 05/22/2018] [Indexed: 12/12/2022] Open
Abstract
The significance of fatty acid metabolism in cancer initiation and development is increasingly accepted by scientists and the public due to the high prevalence of overweight and obese individuals. Fatty acids have different turnovers in the body: Either breakdown into acetyl-CoA to aid ATP generation through catabolic metabolism or incorporation into triacylglycerol and phospholipid through anabolic metabolism. However, these two distinct pathways require a common initial step known as fatty acid activation. Long-chain acyl-CoA synthetases (ACSLs), which are responsible for activation of the most abundant long-chain fatty acids, are commonly deregulated in cancer. This deregulation is also associated with poor survival in patients with cancer. Fatty acids physiologically regulate ACSL expression, but cancer cells could hijack certain involved regulatory mechanisms to deregulate ACSLs. Among the five family isoforms, ACSL1 and ACSL4 are able to promote ungoverned cell growth, facilitate tumor invasion and evade programmed cell death, while ACSL3 may have relatively complex functions in different types of cancer. Notably, ACSL4 is also essential for the induction of ferroptosis (another form of programmed cell death) by facilitating arachidonic acid oxidation, which makes the enzyme a desirable cancer target. The present review thus evaluates the functions of deregulated ACSLs in cancer, the possible molecular mechanisms involved and the chemotherapeutic potentials to target ACSLs. A better understanding of the pathological effects of ACSLs in cancer and the involved molecular mechanisms will aid in delineating the exact role of fatty acid metabolism in cancer and designing precise cancer prevention and treatment strategies.
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Affiliation(s)
- Yue Tang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.,Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Jing Zhou
- Department of Physiology, School of Preclinical Medicine, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Shing Chuan Hooi
- Department of Physiology, Yong Loo Lim School of Medicine, National University of Singapore, Singapore 117543, Republic of Singapore
| | - Yue-Ming Jiang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Guo-Dong Lu
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.,Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.,Key Laboratory of High-Incidence-Tumor Prevention and Treatment, Guangxi Medical University, Ministry of Education of China, Nanning, Guangxi 530021, P.R. China
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207
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Yazdani A, Yazdani A, Bowman TA, Marotta F, Cooke JP, Samiei A. Arachidonic acid as a target for treating hypertriglyceridemia reproduced by a causal network analysis and an intervention study. Metabolomics 2018; 14:78. [PMID: 30830364 DOI: 10.1007/s11306-018-1368-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/05/2018] [Indexed: 02/07/2023]
Affiliation(s)
- Azam Yazdani
- University of Texas, Health Science Center, Houston, TX, 77030, USA.
- Climax Data Pattern, Houston, TX, USA.
| | - Akram Yazdani
- Climax Data Pattern, Houston, TX, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, 10029, USA
| | - Thomas A Bowman
- Jarrow Formulas, Inc., 1824 S. Robertson Blvd, Los Angeles, CA, 90035, USA
| | | | - John P Cooke
- Department of Cardiovascular Sciences, Houston Methodist, Houston, USA
| | - Ahmad Samiei
- Climax Data Pattern, Houston, TX, USA
- Hasso Plattner Institute, 14482, Potsdam, Germany
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208
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Kawashima Y, Eguchi Y, Yamazaki T, Karahashi M, Kawai H, Kudo N. Reduction in Secretion of Very Low Density Lipoprotein–Triacylglycerol by a Matrix Metalloproteinase Inhibitor in a Rat Model of Diet-Induced Hypertriglyceridemia. J Pharmacol Exp Ther 2018; 366:194-204. [DOI: 10.1124/jpet.117.246165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 05/03/2018] [Indexed: 01/11/2023] Open
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209
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Zhang J, Huang Y, Chen J, Zhu H, Whiteheart SW. Dynamic cycling of t-SNARE acylation regulates platelet exocytosis. J Biol Chem 2018; 293:3593-3606. [PMID: 29352103 PMCID: PMC5846156 DOI: 10.1074/jbc.ra117.000140] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/12/2018] [Indexed: 12/16/2022] Open
Abstract
Platelets regulate vascular integrity by secreting a host of molecules that promote hemostasis and its sequelae. Given the importance of platelet exocytosis, it is critical to understand how it is controlled. The t-SNAREs, SNAP-23 and syntaxin-11, lack classical transmembrane domains (TMDs), yet both are associated with platelet membranes and redistributed into cholesterol-dependent lipid rafts when platelets are activated. Using metabolic labeling and hydroxylamine (HA)/HCl treatment, we showed that both contain thioester-linked acyl groups. Mass spectrometry mapping further showed that syntaxin-11 was modified on cysteine 275, 279, 280, 282, 283, and 285, and SNAP-23 was modified on cysteine 79, 80, 83, 85, and 87. Interestingly, metabolic labeling studies showed incorporation of [3H]palmitate into the t-SNAREs increased although the protein levels were unchanged, suggesting that acylation turns over on the two t-SNAREs in resting platelets. Exogenously added fatty acids did compete with [3H]palmitate for t-SNARE labeling. To determine the effects of acylation, we measured aggregation, ADP/ATP release, as well as P-selectin exposure in platelets treated with the acyltransferase inhibitor cerulenin or the thioesterase inhibitor palmostatin B. We found that cerulenin pretreatment inhibited t-SNARE acylation and platelet function in a dose- and time-dependent manner whereas palmostatin B had no detectable effect. Interestingly, pretreatment with palmostatin B blocked the inhibitory effects of cerulenin, suggesting that maintaining the acylation state is important for platelet function. Thus, our work shows that t-SNARE acylation is actively cycling in platelets and suggests that the enzymes regulating protein acylation could be potential targets to control platelet exocytosis in vivo.
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Affiliation(s)
- Jinchao Zhang
- From the Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Yunjie Huang
- From the Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Jing Chen
- From the Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Haining Zhu
- From the Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Sidney W Whiteheart
- From the Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536
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210
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Poppelreuther M, Sander S, Minden F, Dietz MS, Exner T, Du C, Zhang I, Ehehalt F, Knüppel L, Domschke S, Badenhop A, Staudacher S, Ehehalt R, Stremmel W, Thiele C, Heilemann M, Füllekrug J. The metabolic capacity of lipid droplet localized acyl-CoA synthetase 3 is not sufficient to support local triglyceride synthesis independent of the endoplasmic reticulum in A431 cells. Biochim Biophys Acta Mol Cell Biol Lipids 2018. [PMID: 29526665 DOI: 10.1016/j.bbalip.2018.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
ACSL3 is the only long chain fatty acyl-CoA synthetase consistently found on growing and mature lipid droplets (LDs), suggesting that this specific localization has biological relevance. Current models for LD growth propose that triglycerides are synthesized by enzymes at the LD surface, with activated fatty acids provided by LD localized ACSL3, thus allowing growth independent of the ER. Here, we tested this hypothesis by quantifying ACSL3 on LDs from human A431 cells. RNAi of ACSL3 reduced the oleoyl-CoA synthetase activity by 83%, suggesting that ACSL3 is by far the dominant enzyme of A431 cells. Molar quantification revealed that there are 1.4 million ACSL3 molecules within a single cell. Metabolic labeling indicated that each ACSL3 molecule contributed a net gain of 3.1 oleoyl-CoA/s. 3D reconstruction of confocal images demonstrated that 530 individual lipid droplets were present in an average oleate fed A431 cell. A representative single lipid droplet with a diameter of 0.66 μm contained 680 ACSL3 molecules on the surface. Subcellular fractionation showed that at least 68% of ACSL3 remain at the ER even during extensive fatty acid supplementation. High resolution single molecule microscopy confirmed the abundance of cytoplasmic ACSL3 outside of LDs. Model calculations for triglyceride synthesis using only LD localized ACSL3 gave significant slower growth of LDs as observed experimentally. In conclusion, although ACSL3 is an abundant enzyme on A431 LDs, the metabolic capacity is not sufficient to account for LD growth solely by the local synthesis of triglycerides.
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Affiliation(s)
| | - Simone Sander
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Fadil Minden
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Marina S Dietz
- Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
| | - Tarik Exner
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Chen Du
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Ingrid Zhang
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Friedrich Ehehalt
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Laura Knüppel
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Susanne Domschke
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Anna Badenhop
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Sarah Staudacher
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Robert Ehehalt
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Wolfgang Stremmel
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Christoph Thiele
- Life and Medical Sciences Institute, University of Bonn, Germany
| | - Mike Heilemann
- Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
| | - Joachim Füllekrug
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany.
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211
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Knottnerus SJG, Bleeker JC, Wüst RCI, Ferdinandusse S, IJlst L, Wijburg FA, Wanders RJA, Visser G, Houtkooper RH. Disorders of mitochondrial long-chain fatty acid oxidation and the carnitine shuttle. Rev Endocr Metab Disord 2018; 19:93-106. [PMID: 29926323 PMCID: PMC6208583 DOI: 10.1007/s11154-018-9448-1] [Citation(s) in RCA: 178] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mitochondrial fatty acid oxidation is an essential pathway for energy production, especially during prolonged fasting and sub-maximal exercise. Long-chain fatty acids are the most abundant fatty acids in the human diet and in body stores, and more than 15 enzymes are involved in long-chain fatty acid oxidation. Pathogenic mutations in genes encoding these enzymes result in a long-chain fatty acid oxidation disorder in which the energy homeostasis is compromised and long-chain acylcarnitines accumulate. Symptoms arise or exacerbate during catabolic situations, such as fasting, illness and (endurance) exercise. The clinical spectrum is very heterogeneous, ranging from hypoketotic hypoglycemia, liver dysfunction, rhabdomyolysis, cardiomyopathy and early demise. With the introduction of several of the long-chain fatty acid oxidation disorders (lcFAOD) in newborn screening panels, also asymptomatic individuals with a lcFAOD are identified. However, despite early diagnosis and dietary therapy, a significant number of patients still develop symptoms emphasizing the need for individualized treatment strategies. This review aims to function as a comprehensive reference for clinical and laboratory findings for clinicians who are confronted with pediatric and adult patients with a possible diagnosis of a lcFAOD.
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Affiliation(s)
- Suzan J G Knottnerus
- Dutch Fatty Acid Oxidation Expertise Center, Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, 3584, EA, Utrecht, The Netherlands
- Dutch Fatty Acid Oxidation Expertise Center, Laboratory Genetic Metabolic Diseases, Departments of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Jeannette C Bleeker
- Dutch Fatty Acid Oxidation Expertise Center, Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, 3584, EA, Utrecht, The Netherlands
- Dutch Fatty Acid Oxidation Expertise Center, Laboratory Genetic Metabolic Diseases, Departments of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Rob C I Wüst
- Dutch Fatty Acid Oxidation Expertise Center, Laboratory Genetic Metabolic Diseases, Departments of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Sacha Ferdinandusse
- Dutch Fatty Acid Oxidation Expertise Center, Laboratory Genetic Metabolic Diseases, Departments of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Lodewijk IJlst
- Dutch Fatty Acid Oxidation Expertise Center, Laboratory Genetic Metabolic Diseases, Departments of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Frits A Wijburg
- Dutch Fatty Acid Oxidation Expertise Center, Laboratory Genetic Metabolic Diseases, Departments of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Ronald J A Wanders
- Dutch Fatty Acid Oxidation Expertise Center, Laboratory Genetic Metabolic Diseases, Departments of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Gepke Visser
- Dutch Fatty Acid Oxidation Expertise Center, Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, 3584, EA, Utrecht, The Netherlands.
- Dutch Fatty Acid Oxidation Expertise Center, Laboratory Genetic Metabolic Diseases, Departments of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands.
| | - Riekelt H Houtkooper
- Dutch Fatty Acid Oxidation Expertise Center, Laboratory Genetic Metabolic Diseases, Departments of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands.
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212
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Desai A, Alves-Bezerra M, Li Y, Ozdemir C, Bare CJ, Li Y, Hagen SJ, Cohen DE. Regulation of fatty acid trafficking in liver by thioesterase superfamily member 1. J Lipid Res 2018; 59:368-379. [PMID: 29208699 PMCID: PMC5794430 DOI: 10.1194/jlr.m081455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/04/2017] [Indexed: 12/13/2022] Open
Abstract
Thioesterase superfamily member 1 (Them1) is an acyl-CoA thioesterase that is highly expressed in brown adipose tissue, where it functions to suppress energy expenditure. Lower Them1 expression levels in the liver are upregulated in response to high-fat feeding. Them1-/- mice are resistant to diet-induced obesity, hepatic steatosis, and glucose intolerance, but the contribution of Them1 in liver is unclear. To examine its liver-specific functions, we created conditional transgenic mice, which, when bred to Them1-/- mice and activated, expressed Them1 exclusively in the liver. Mice with liver-specific Them1 expression exhibited no changes in energy expenditure. Rates of fatty acid oxidation were increased, whereas hepatic VLDL triglyceride secretion rates were decreased by hepatic Them1 expression. When fed a high-fat diet, Them1 expression in liver promoted excess steatosis in the setting of reduced rates of fatty acid oxidation and preserved glycerolipid synthesis. Liver-specific Them1 expression did not influence glucose tolerance or insulin sensitivity, but did promote hepatic gluconeogenesis in high-fat-fed animals. This was attributable to the generation of excess fatty acids, which activated PPARα and promoted expression of gluconeogenic genes. These findings reveal a regulatory role for Them1 in hepatocellular fatty acid trafficking.
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Affiliation(s)
- Anal Desai
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
| | - Michele Alves-Bezerra
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
| | - Yingxia Li
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
| | - Cafer Ozdemir
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118
| | - Curtis J Bare
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
| | - Yue Li
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215
| | - Susan J Hagen
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215
| | - David E Cohen
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021
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213
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Han Z, Wu H, Kim S, Yang X, Li Q, Huang H, Cai H, Bartlett MG, Dong A, Zeng H, Brown PJ, Yang XJ, Arrowsmith CH, Zhao Y, Zheng YG. Revealing the protein propionylation activity of the histone acetyltransferase MOF (males absent on the first). J Biol Chem 2018; 293:3410-3420. [PMID: 29321206 DOI: 10.1074/jbc.ra117.000529] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 12/20/2017] [Indexed: 11/06/2022] Open
Abstract
Short-chain acylation of lysine residues has recently emerged as a group of reversible posttranslational modifications in mammalian cells. The diversity of acylation further broadens the landscape and complexity of the proteome. Identification of regulatory enzymes and effector proteins for lysine acylation is critical to understand functions of these novel modifications at the molecular level. Here, we report that the MYST family of lysine acetyltransferases (KATs) possesses strong propionyltransferase activity both in vitro and in cellulo Particularly, the propionyltransferase activity of MOF, MOZ, and HBO1 is as strong as their acetyltransferase activity. Overexpression of MOF in human embryonic kidney 293T cells induced significantly increased propionylation in multiple histone and non-histone proteins, which shows that the function of MOF goes far beyond its canonical histone H4 lysine 16 acetylation. We also resolved the X-ray co-crystal structure of MOF bound with propionyl-coenzyme A, which provides a direct structural basis for the propionyltransferase activity of the MYST KATs. Our data together define a novel function for the MYST KATs as lysine propionyltransferases and suggest much broader physiological impacts for this family of enzymes.
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Affiliation(s)
- Zhen Han
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602
| | - Hong Wu
- the Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Sunjoo Kim
- the Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois 60637
| | - Xiangkun Yang
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602
| | - Qianjin Li
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602
| | - He Huang
- the Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois 60637
| | - Houjian Cai
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602
| | - Michael G Bartlett
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602
| | - Aiping Dong
- the Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Hong Zeng
- the Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Peter J Brown
- the Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Xiang-Jiao Yang
- the Goodman Cancer Research Center and Department of Medicine, McGill University, Montreal, Quebec H3A 1A3, Canada, and
| | - Cheryl H Arrowsmith
- the Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada.,the Princess Margaret Cancer Centre and Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | - Yingming Zhao
- the Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois 60637
| | - Y George Zheng
- From the Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602,
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214
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Shi HB, Zhang CH, Xu ZA, Lou GG, Liu JX, Luo J, Loor JJ. Peroxisome proliferator-activated receptor delta regulates lipid droplet formation and transport in goat mammary epithelial cells. J Dairy Sci 2018; 101:2641-2649. [PMID: 29331469 DOI: 10.3168/jds.2017-13543] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 11/27/2017] [Indexed: 12/15/2022]
Abstract
Even though recent evidence in goat mammary epithelial cells (GMEC) suggest a role of peroxisome proliferator-activated receptor delta (PPARD) in regulating lipid homeostasis, its role is not fully understood. Our hypothesis was that PPARD regulates lipid transport processes in GMEC and, thus, plays a crucial role in regulating fat formation. The PPARD was overexpressed using an adenovirus system (Ad-PPARD) with recombinant green fluorescent protein (Ad-GFP) as the control. Results revealed that overexpression of PPARD markedly upregulated the mRNA abundance of PPARD. Compared with the control (Ad-GFP+dimethyl sulfoxide), overexpression of PPARD alone had no effect on mRNA expression of CD36, SCD1, FABP4, ACSL1, and ADRP. The cultures overexpressing PPARD with the PPARD ligand GW0742 (GW) upregulated the expression of CD36, FABP3, FABP4, ACSL1, and ADRP. Overexpression of PPARD in GMEC plus GW increased the concentration of 16:1 and 18:1-trans and was associated with upregulation of SCD1. Compared with the control (Ad-GFP+dimethyl sulfoxide), the decrease of triacylglycerol concentration coupled with upregulation of genes related to lipid droplet secretion (e.g., ADRP and ACSL1) induced by PPARD overexpression suggests a role in lipid droplet (LD) secretion. Luciferase assay revealed that GW increased the ADRP promoter activity in a dose-dependent manner. Knockdown of PPARD impaired the increase of ADRP promoter activity induced by GW, whereas GW enhanced the activity of ADRP promoter in GMEC overexpressing PPARD. Data with the ADRP 5'-flanking truncated luciferase reporter suggest a core region (-1,444 to -990 bp) response element for the induction of GW. This core region contains a known PPARG response element (PPRE) at -1,003 to -990 bp. When the PPRE was mutated, the overexpression of PPARD had no effect on ADRP promoter activity. Collectively, these results reveal a novel role for PPARD in lipid homeostasis via promoting fatty acid transport and LD formation through a mechanism of direct binding to the promoter of key genes. Hence, PPARD activity may contribute to fatty acid transport and LD formation during lactation.
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Affiliation(s)
- H B Shi
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018, P. R. China; College of Animal Sciences, Zhejiang University, Hangzhou 310058, P. R. China
| | - C H Zhang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, P. R. China
| | - Z A Xu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018, P. R. China
| | - G G Lou
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018, P. R. China
| | - J X Liu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, P. R. China
| | - J Luo
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, P. R. China.
| | - J J Loor
- Mammalian NutriPhysioGenomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana 61801.
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215
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Thimgan MS, Kress N, Lisse J, Fiebelman C, Hilderbrand T. The acyl-CoA Synthetase, pudgy, Promotes Sleep and Is Required for the Homeostatic Response to Sleep Deprivation. Front Endocrinol (Lausanne) 2018; 9:464. [PMID: 30186232 PMCID: PMC6110854 DOI: 10.3389/fendo.2018.00464] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 07/27/2018] [Indexed: 12/12/2022] Open
Abstract
The regulation of sleep and the response to sleep deprivation rely on multiple biochemical pathways. A critical connection is the link between sleep and metabolism. Metabolic changes can disrupt sleep, and conversely decreased sleep can alter the metabolic environment. There is building evidence that lipid metabolism, in particular, is a critical part of mounting the homeostatic response to sleep deprivation. We have evaluated an acyl-CoA synthetase, pudgy (pdgy), for its role in sleep and response to sleep deprivation. When pdgy transcript levels are decreased through transposable element disruption of the gene, mutant flies showed lower total sleep times and increased sleep fragmentation at night compared to genetic controls. Consistent with disrupted sleep, mutant flies had a decreased lifespan compared to controls. pdgy disrupted fatty acid handling as pdgy mutants showed increased sensitivity to starvation and exhibited lower fat stores. Moreover, the response to sleep deprivation is reduced when compared to a control flies. When we decreased the transcript levels for pdgy using RNAi, the response to sleep deprivation was decreased compared to background controls. In addition, when the pdgy transcription is rescued throughout the fly, the response to sleep deprivation is restored. These data demonstrate that the regulation and function of acyl-CoA synthetase plays a critical role in regulating sleep and the response to sleep deprivation. Endocrine and metabolic signals that alter transcript levels of pdgy impact sleep regulation or interfere with the homeostatic response to sleep deprivation.
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Affiliation(s)
- Matthew S. Thimgan
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO, United States
- *Correspondence: Matthew S. Thimgan
| | - Natalie Kress
- Department of Neuroscience, Washington University School of Medicine in St. Louis, St. Louis, MO, United States
| | - Josh Lisse
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO, United States
| | - Courtney Fiebelman
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO, United States
| | - Thomas Hilderbrand
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO, United States
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216
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Abstract
Triglyceride molecules represent the major form of storage and transport of fatty acids within cells and in the plasma. The liver is the central organ for fatty acid metabolism. Fatty acids accrue in liver by hepatocellular uptake from the plasma and by de novo biosynthesis. Fatty acids are eliminated by oxidation within the cell or by secretion into the plasma within triglyceride-rich very low-density lipoproteins. Notwithstanding high fluxes through these pathways, under normal circumstances the liver stores only small amounts of fatty acids as triglycerides. In the setting of overnutrition and obesity, hepatic fatty acid metabolism is altered, commonly leading to the accumulation of triglycerides within hepatocytes, and to a clinical condition known as nonalcoholic fatty liver disease (NAFLD). In this review, we describe the current understanding of fatty acid and triglyceride metabolism in the liver and its regulation in health and disease, identifying potential directions for future research. Advances in understanding the molecular mechanisms underlying the hepatic fat accumulation are critical to the development of targeted therapies for NAFLD. © 2018 American Physiological Society. Compr Physiol 8:1-22, 2018.
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Affiliation(s)
- Michele Alves-Bezerra
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, USA
| | - David E Cohen
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, USA
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217
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Han van der Kolk JH, Gross JJ, Gerber V, Bruckmaier RM. Disturbed bovine mitochondrial lipid metabolism: a review. Vet Q 2017; 37:262-273. [PMID: 28712316 DOI: 10.1080/01652176.2017.1354561] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In mammals, excess energy is stored primarily as triglycerides, which are mobilized when energy demands arise and cannot be covered by feed intake. This review mainly focuses on the role of long chain fatty acids in disturbed energy metabolism of the bovine species. Long chain fatty acids regulate energy metabolism as ligands of peroxisome proliferator-activated receptors. Carnitine acts as a carrier of fatty acyl groups as long-chain acyl-CoA derivatives do not penetrate the mitochondrial inner membrane. There are two different types of disorders in lipid metabolism which can occur in cattle, namely the hypoglycaemic-hypoinsulinaemic and the hyperglycaemic-hyperinsulinaemic type with the latter not always associated with ketosis. There is general agreement that fatty acid β-oxidation capability is limited in the liver of (ketotic) cows. In accord, supplemental L-carnitine decreased liver lipid accumulation in periparturient Holstein cows. Of note, around parturition concurrent oxidation of fatty acids in skeletal muscle is highly activated. Also peroxisomal β-oxidation in liver of dairy cows may be part of the hepatic adaptations to a negative energy balance (NEB) to break down fatty acids. An elevated blood concentration of nonesterified fatty acids is one of the indicators of NEB in cattle among others like increased β-hydroxy butyrate concentration, and decreased concentrations of glucose, insulin, and insulin-like growth factor-I. Assuming that liver carnitine concentrations might limit hepatic fatty acid oxidation capacity in dairy cows, further study of the role of acyl-CoA dehydrogenases and/or riboflavin in bovine ketosis is warranted.
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Affiliation(s)
- J H Han van der Kolk
- a Division of Clinical Veterinary Medicine, Swiss Institute for Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty , University of Bern and Agroscope , Bern , Switzerland
| | - J J Gross
- b Veterinary Physiology, Vetsuisse Faculty , University of Bern , Bern , Switzerland
| | - V Gerber
- a Division of Clinical Veterinary Medicine, Swiss Institute for Equine Medicine (ISME), Department of Clinical Veterinary Medicine, Vetsuisse Faculty , University of Bern and Agroscope , Bern , Switzerland
| | - R M Bruckmaier
- b Veterinary Physiology, Vetsuisse Faculty , University of Bern , Bern , Switzerland
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218
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Ersoy BA, Maner-Smith KM, Li Y, Alpertunga I, Cohen DE. Thioesterase-mediated control of cellular calcium homeostasis enables hepatic ER stress. J Clin Invest 2017; 128:141-156. [PMID: 29202465 DOI: 10.1172/jci93123] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 10/12/2017] [Indexed: 12/11/2022] Open
Abstract
The incorporation of excess saturated free fatty acids (SFAs) into membrane phospholipids within the ER promotes ER stress, insulin resistance, and hepatic gluconeogenesis. Thioesterase superfamily member 2 (Them2) is a mitochondria-associated long-chain fatty acyl-CoA thioesterase that is activated upon binding phosphatidylcholine transfer protein (PC-TP). Under fasting conditions, the Them2/PC-TP complex directs saturated fatty acyl-CoA toward β-oxidation. Here, we showed that during either chronic overnutrition or acute induction of ER stress, Them2 and PC-TP play critical roles in trafficking SFAs into the glycerolipid biosynthetic pathway to form saturated phospholipids, which ultimately reduce ER membrane fluidity. The Them2/PC-TP complex activated ER stress pathways by enhancing translocon-mediated efflux of ER calcium. The increased cytosolic calcium, in turn, led to the phosphorylation of calcium/calmodulin-dependent protein kinase II, which promoted both hepatic insulin resistance and gluconeogenesis. These findings delineate a mechanistic link between obesity and insulin resistance and establish the Them2/PC-TP complex as an attractive target for the management of hepatic steatosis and insulin resistance.
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219
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Kim S, Alsaidan OA, Goodwin O, Li Q, Sulejmani E, Han Z, Bai A, Albers T, Beharry Z, Zheng YG, Norris JS, Szulc ZM, Bielawska A, Lebedyeva I, Pegan SD, Cai H. Blocking Myristoylation of Src Inhibits Its Kinase Activity and Suppresses Prostate Cancer Progression. Cancer Res 2017; 77:6950-6962. [PMID: 29038344 DOI: 10.1158/0008-5472.can-17-0981] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 08/24/2017] [Accepted: 10/09/2017] [Indexed: 11/16/2022]
Abstract
Protein N-myristoylation enables localization to membranes and helps maintain protein conformation and function. N-myristoyltransferases (NMT) catalyze co- or posttranslational myristoylation of Src family kinases and other oncogenic proteins, thereby regulating their function. In this study, we provide genetic and pharmacologic evidence that inhibiting the N-myristoyltransferase NMT1 suppresses cell-cycle progression, proliferation, and malignant growth of prostate cancer cells. Loss of myristoylation abolished the tumorigenic potential of Src and its synergy with androgen receptor in mediating tumor invasion. We identified the myristoyl-CoA analogue B13 as a small-molecule inhibitor of NMT1 enzymatic activity. B13 exposure blocked Src myristoylation and Src localization to the cytoplasmic membrane, attenuating Src-mediated oncogenic signaling. B13 exerted its anti-invasive and antitumor effects against prostate cancer cells, with minimal toxic side-effects in vivo Structural optimization based on structure-activity relationships enabled the chemical synthesis of LCL204, with enhanced inhibitory potency against NMT1. Collectively, our results offer a preclinical proof of concept for the use of protein myristoylation inhibitors as a strategy to block prostate cancer progression. Cancer Res; 77(24); 6950-62. ©2017 AACR.
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Affiliation(s)
- Sungjin Kim
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia Athens, Athens, Georgia
| | - Omar Awad Alsaidan
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia Athens, Athens, Georgia
| | - Octavia Goodwin
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia Athens, Athens, Georgia
| | - Qianjin Li
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia Athens, Athens, Georgia
| | - Essilvo Sulejmani
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia Athens, Athens, Georgia
| | - Zhen Han
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia Athens, Athens, Georgia
| | - Aiping Bai
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina
| | - Thomas Albers
- Department of Chemistry and Physics, Augusta University, Augusta, Georgia
| | - Zanna Beharry
- Department of Chemistry and Physics, Florida Gulf Coast University, Fort Myers, Florida
| | - Y George Zheng
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia Athens, Athens, Georgia
| | - James S Norris
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina
| | - Zdzislaw M Szulc
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina
| | - Alicja Bielawska
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina
| | - Iryna Lebedyeva
- Department of Chemistry and Physics, Augusta University, Augusta, Georgia
| | - Scott D Pegan
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia Athens, Athens, Georgia
| | - Houjian Cai
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia Athens, Athens, Georgia.
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220
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Kim S, Yang X, Li Q, Wu M, Costyn L, Beharry Z, Bartlett MG, Cai H. Myristoylation of Src kinase mediates Src-induced and high-fat diet-accelerated prostate tumor progression in mice. J Biol Chem 2017; 292:18422-18433. [PMID: 28939770 DOI: 10.1074/jbc.m117.798827] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 09/21/2017] [Indexed: 12/11/2022] Open
Abstract
Exogenous fatty acids provide substrates for energy production and biogenesis of the cytoplasmic membrane, but they also enhance cellular signaling during cancer cell proliferation. However, it remains controversial whether dietary fatty acids are correlated with tumor progression. In this study, we demonstrate that increased Src kinase activity is associated with high-fat diet-accelerated progression of prostate tumors and that Src kinases mediate this pathological process. Moreover, in the in vivo prostate regeneration assay, host SCID mice carrying Src(Y529F)-transduced regeneration tissues were fed a low-fat diet or a high-fat diet and treated with vehicle or dasatinib. The high-fat diet not only accelerated Src-induced prostate tumorigenesis in mice but also compromised the inhibitory effect of the anticancer drug dasatinib on Src kinase oncogenic potential in vivo We further show that myristoylation of Src kinase is essential to facilitate Src-induced and high-fat diet-accelerated tumor progression. Mechanistically, metabolism of exogenous myristic acid increased the biosynthesis of myristoyl CoA and myristoylated Src and promoted Src kinase-mediated oncogenic signaling in human cells. Of the fatty acids tested, only exogenous myristic acid contributed to increased intracellular myristoyl CoA levels. Our results suggest that targeting Src kinase myristoylation, which is required for Src kinase association at the cellular membrane, blocks dietary fat-accelerated tumorigenesis in vivo Our findings uncover the molecular basis of how the metabolism of myristic acid stimulates high-fat diet-mediated prostate tumor progression.
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Affiliation(s)
- Sungjin Kim
- From the Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602 and
| | - Xiangkun Yang
- From the Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602 and
| | - Qianjin Li
- From the Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602 and
| | - Meng Wu
- From the Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602 and
| | - Leah Costyn
- From the Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602 and
| | - Zanna Beharry
- the Department of Chemistry and Physics, Florida Gulf Coast University, Fort Myers, Florida 33965
| | - Michael G Bartlett
- From the Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602 and
| | - Houjian Cai
- From the Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602 and
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221
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Barbosa AD, Siniossoglou S. Function of lipid droplet-organelle interactions in lipid homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1459-1468. [DOI: 10.1016/j.bbamcr.2017.04.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 03/31/2017] [Accepted: 04/02/2017] [Indexed: 12/20/2022]
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222
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CDCP1 drives triple-negative breast cancer metastasis through reduction of lipid-droplet abundance and stimulation of fatty acid oxidation. Proc Natl Acad Sci U S A 2017; 114:E6556-E6565. [PMID: 28739932 DOI: 10.1073/pnas.1703791114] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Triple-negative breast cancer (TNBC) is notoriously aggressive with high metastatic potential, which has recently been linked to high rates of fatty acid oxidation (FAO). Here we report the mechanism of lipid metabolism dysregulation in TNBC through the prometastatic protein, CUB-domain containing protein 1 (CDCP1). We show that a "low-lipid" phenotype is characteristic of breast cancer cells compared with normal breast epithelial cells and negatively correlates with invasiveness in 3D culture. Using coherent anti-Stokes Raman scattering and two-photon excited fluorescence microscopy, we show that CDCP1 depletes lipids from cytoplasmic lipid droplets (LDs) through reduced acyl-CoA production and increased lipid utilization in the mitochondria through FAO, fueling oxidative phosphorylation. These findings are supported by CDCP1's interaction with and inhibition of acyl CoA-synthetase ligase (ACSL) activity. Importantly, CDCP1 knockdown increases LD abundance and reduces TNBC 2D migration in vitro, which can be partially rescued by the ACSL inhibitor, Triacsin C. Furthermore, CDCP1 knockdown reduced 3D invasion, which can be rescued by ACSL3 co-knockdown. In vivo, inhibiting CDCP1 activity with an engineered blocking fragment (extracellular portion of cleaved CDCP1) lead to increased LD abundance in primary tumors, decreased metastasis, and increased ACSL activity in two animal models of TNBC. Finally, TNBC lung metastases have lower LD abundance than their corresponding primary tumors, indicating that LD abundance in primary tumor might serve as a prognostic marker for metastatic potential. Our studies have important implications for the development of TNBC therapeutics to specifically block CDCP1-driven FAO and oxidative phosphorylation, which contribute to TNBC migration and metastasis.
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223
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Stremmel W, Staffer S, Wannhoff A, Pathil A. The overall fatty acid absorption controlled by basolateral chylomicron excretion under regulation of p-JNK1. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:917-928. [PMID: 28602806 DOI: 10.1016/j.bbalip.2017.05.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 05/05/2017] [Accepted: 05/17/2017] [Indexed: 11/26/2022]
Abstract
Suppression of fatty acid absorption is one goal to fight obesity. However, the responsible molecular mechanism is poorly understood. Aim of the present study was the search for the key regulator of the overall fatty acid absorption mechanism and its pharmaceutical modulation. As experimental tool we employed the polarized human intestinal tumor derived cell line CaCo2. Here we showed that influx of fatty acids is mediated by an apical heterotetrameric plasma membrane protein complex of which the calcium-independent membrane phospholipase A2 (iPLA2ß) is one constituent. The newly synthesized bile acid-phospholipid conjugate ursodeoxycholate-lysophosphatidylethanolamide (UDCA-LPE) blocked iPLA2ß, which structurally disrupted the fatty acid-uptake complex. Furthermore, the inhibition of iPLA2ß lead to reduction of cytosolic lysophosphatidylcholine (LPC) production which suppressed p-JNK1, as a central regulator of metabolism. In a concerted action low p-JNK1 levels prohibited synthesis of the members of the fatty acid uptake complex as well as of apolipoprotein B and the connected members of the basolateral vesicular chylomicron excretion machinery, thereby inhibiting cellular lipid excretion. The basolateral chylomicron release was shown to determine the overall fatty acid-absorption capacity as rate limiting step, whereas apical uptake replenishes the cellular stores, enabling continuous transcellular movement of fatty acids. In conclusion, the UDCA-LPE mediated inhibition of p-JNK1 represents a powerful tool to control intestinal absorption of fatty acids and, thus may be employed as a drug to treat obesity.
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Affiliation(s)
- Wolfgang Stremmel
- Department of Internal Medicine, University Hospital of Heidelberg, INF 410, 69120 Heidelberg, Germany.
| | - Simone Staffer
- Department of Internal Medicine, University Hospital of Heidelberg, INF 410, 69120 Heidelberg, Germany
| | - Andreas Wannhoff
- Department of Internal Medicine, University Hospital of Heidelberg, INF 410, 69120 Heidelberg, Germany
| | - Anita Pathil
- Department of Internal Medicine, University Hospital of Heidelberg, INF 410, 69120 Heidelberg, Germany
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224
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Belkaid A, Ouellette RJ, Surette ME. 17β-estradiol-induced ACSL4 protein expression promotes an invasive phenotype in estrogen receptor positive mammary carcinoma cells. Carcinogenesis 2017; 38:402-410. [PMID: 28334272 DOI: 10.1093/carcin/bgx020] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 02/20/2017] [Indexed: 12/16/2022] Open
Abstract
Long chain acyl-CoA synthase-4 (ACSL4) expression has been associated with an aggressive phenotype in breast carcinoma cells, whereas its role in ERα-positive breast cancer has not been studied. ACSL4 prefers 20-carbon polyunsaturated fatty acid (PUFA) substrates, and along with other ACSLs has been associated with cellular uptake of exogenous fatty acids. 17β-estradiol induces proliferation and invasive capacities in ERα+ve breast carcinoma that is associated with modifications of cellular lipid metabolism. In this study, treatment of steroid-starved ERα-positive MCF-7 and T47D mammary carcinoma cells with 17β-estradiol resulted in increased cellular uptake of the PUFA arachidonic acid (AA) and eicosapentaenoic acid (EPA), important building blocks for cellular membranes, and increased ACSL4 protein levels. There was no change in the expression of the ACSL1, ACSL3 and ACSL6 protein isotypes. Increased ACSL4 protein expression was not accompanied by changes in ACSL4 mRNA expression, but was associated with a significant increase in the protein half-life compared to untreated cells. ERα silencing reversed the impact of 17β-estradiol on ACSL4 protein levels and half-life. Silencing of ACSL4 eliminated the 17β-estradiol-induced increase in AA and EPA uptake, as well as the 17β-estradiol-induced cell migration, proliferation and invasion capacities. ASCL4 silencing also prevented the 17β-estradiol induced increases in p-Akt and p-GSK3β, and decrease in E-cadherin expression, important events in epithelial to mesenchymal transition. Taken together, these results demonstrate that ACSL4 is a target of 17β-estradiol-stimulated ERα and is required for the cellular uptake of exogenous PUFA and the manifestation of a more malignant phenotype in ERα+ve breast carcinoma cells.
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Affiliation(s)
- Anissa Belkaid
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada and.,Atlantic Cancer Research Institute, Moncton, NB E1C 8X3, Canada
| | | | - Marc E Surette
- Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB E1A 3E9, Canada and
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225
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Micheletto MC, Mendes LFS, Basso LGM, Fonseca-Maldonado RG, Costa-Filho AJ. Lipid membranes and acyl-CoA esters promote opposing effects on acyl-CoA binding protein structure and stability. Int J Biol Macromol 2017; 102:284-296. [PMID: 28390829 DOI: 10.1016/j.ijbiomac.2017.03.197] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 12/21/2022]
Abstract
Acyl-CoA Binding Proteins (ACBP) form a housekeeping family of proteins that is responsible for the buffering of long chain acyl-coenzyme A esters (LCFA-CoA) inside the cell. Even though numerous studies have focused on the characterization of different members of the ACBP family, the knowledge about the impact of both LCFA-CoA and phospholipids on ACBP structure and stability remains scarce. Besides, there are still controversies regarding the possible interaction of ACBP with biological membranes, even though this might be essential for the cargo capture and delivery. In this study, we observed that LCFA-CoA and phospholipids play opposite roles on protein stability and that the interaction with the membrane is dictated by electrostatic interaction. Furthermore, the results support the hypothesis that the LCFA-CoA delivery is driven by the increase of the negative charge on the membrane surface. The combined influence played by the different molecules on ACBP structure is discussed on the light of cargo capture/delivery giving new insights about this important process.
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Affiliation(s)
- Mariana C Micheletto
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Luís F S Mendes
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Luis G M Basso
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Raquel G Fonseca-Maldonado
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil; Instituto Federal de Educação, Ciência e Tecnologia de São Paulo/IFSP Campus Jacareí-Dept Gestão, Brazil
| | - Antonio J Costa-Filho
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
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226
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Ferreira NS, Engelsby H, Neess D, Kelly SL, Volpert G, Merrill AH, Futerman AH, Færgeman NJ. Regulation of very-long acyl chain ceramide synthesis by acyl-CoA-binding protein. J Biol Chem 2017; 292:7588-7597. [PMID: 28320857 DOI: 10.1074/jbc.m117.785345] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Indexed: 11/06/2022] Open
Abstract
Ceramide and more complex sphingolipids constitute a diverse group of lipids that serve important roles as structural entities of biological membranes and as regulators of cellular growth, differentiation, and development. Thus, ceramides are vital players in numerous diseases including metabolic and cardiovascular diseases, as well as neurological disorders. Here we show that acyl-coenzyme A-binding protein (ACBP) potently facilitates very-long acyl chain ceramide synthesis. ACBP increases the activity of ceramide synthase 2 (CerS2) by more than 2-fold and CerS3 activity by 7-fold. ACBP binds very-long-chain acyl-CoA esters, which is required for its ability to stimulate CerS activity. We also show that high-speed liver cytosol from wild-type mice activates CerS3 activity, whereas cytosol from ACBP knock-out mice does not. Consistently, CerS2 and CerS3 activities are significantly reduced in the testes of ACBP-/- mice, concomitant with a significant reduction in long- and very-long-chain ceramide levels. Importantly, we show that ACBP interacts with CerS2 and CerS3. Our data uncover a novel mode of regulation of very-long acyl chain ceramide synthesis by ACBP, which we anticipate is of crucial importance in understanding the regulation of ceramide metabolism in pathogenesis.
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Affiliation(s)
- Natalia Santos Ferreira
- From the Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Hanne Engelsby
- the Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark, and
| | - Ditte Neess
- the Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark, and
| | - Samuel L Kelly
- the School of Biology and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332-0230
| | - Giora Volpert
- From the Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alfred H Merrill
- the School of Biology and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332-0230
| | - Anthony H Futerman
- From the Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Nils J Færgeman
- the Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark, and
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227
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Senkal CE, Salama MF, Snider AJ, Allopenna JJ, Rana NA, Koller A, Hannun YA, Obeid LM. Ceramide Is Metabolized to Acylceramide and Stored in Lipid Droplets. Cell Metab 2017; 25:686-697. [PMID: 28273483 PMCID: PMC5472424 DOI: 10.1016/j.cmet.2017.02.010] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 11/22/2016] [Accepted: 02/16/2017] [Indexed: 12/26/2022]
Abstract
In an approach aimed at defining interacting partners of ceramide synthases (CerSs), we found that fatty acyl-CoA synthase ACSL5 interacts with all CerSs. We demonstrate that ACSL5-generated FA-CoA was utilized with de novo ceramide for the generation of acylceramides, poorly studied ceramide metabolites. Functionally, inhibition of ceramide channeling to acylceramide enhanced accumulation of de novo ceramide and resulted in augmentation of ceramide-mediated apoptosis. Mechanistically, we show that acylceramide generation is catalyzed by diacylglycerol acyltransferase 2 (DGAT2) on lipid droplets. In summary, this study identifies a metabolic pathway of acylceramide generation and its sequestration in LDs in cells and in livers of mice on a high-fat diet. The study also implicates this pathway in ceramide-mediated apoptosis, and has implications in co-regulation of triglyceride and sphingolipid metabolisms.
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Affiliation(s)
- Can E Senkal
- Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY 11794, USA
| | - Mohamed F Salama
- Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; Department of Biochemistry, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Dakahlia Governorate 35516, Egypt
| | - Ashley J Snider
- Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY 11794, USA; Northport Veterans Affairs Medical Center, Northport, NY 11768, USA
| | - Janet J Allopenna
- Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Nadia A Rana
- Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Antonius Koller
- Proteomics Center, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yusuf A Hannun
- Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY 11794, USA
| | - Lina M Obeid
- Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY 11794, USA; Northport Veterans Affairs Medical Center, Northport, NY 11768, USA.
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228
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Klett EL, Chen S, Yechoor A, Lih FB, Coleman RA. Long-chain acyl-CoA synthetase isoforms differ in preferences for eicosanoid species and long-chain fatty acids. J Lipid Res 2017; 58:884-894. [PMID: 28209804 DOI: 10.1194/jlr.m072512] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 02/16/2017] [Indexed: 01/24/2023] Open
Abstract
Because the signaling eicosanoids, epoxyeicosatrienoic acids (EETs) and HETEs, are esterified to membrane phospholipids, we asked which long-chain acyl-CoA synthetase (ACSL) isoforms would activate these molecules and whether the apparent FA substrate preferences of each ACSL isoform might differ depending on whether it was assayed in mammalian cell membranes or as a purified bacterial recombinant protein. We found that all five ACSL isoforms were able to use EETs and HETEs as substrates and showed by LC-MS/MS that ACSLs produce EET-CoAs. We found differences in substrate preference between ACS assays performed in COS7 cell membranes and recombinant purified proteins. Similarly, preferences and Michaelis-Menten kinetics for long-chain FAs were distinctive. Substrate preferences identified for the purified ACSLs did not correspond to those observed in ACSL-deficient mouse models. Taken together, these data support the concept that each ACSL isoform exhibits a distinct substrate preference, but apparent substrate specificities depend upon multiple factors including membrane character, coactivators, inhibitors, protein interactions, and posttranslational modification.
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Affiliation(s)
- Eric L Klett
- Department of Medicine, Division of Endocrinology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 .,Department of Nutrition, University of North Carolina School of Public Health, Chapel Hill, NC 27599
| | - Shufen Chen
- Department of Medicine, Division of Endocrinology, University of North Carolina School of Medicine, Chapel Hill, NC 27599.,Department of Nutrition, University of North Carolina School of Public Health, Chapel Hill, NC 27599
| | - Alekhya Yechoor
- Department of Nutrition, University of North Carolina School of Public Health, Chapel Hill, NC 27599
| | - Fred B Lih
- Division of Intramural Research, Epigenetics and Stem Cell Biology Laboratory (ESCBL), National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709
| | - Rosalind A Coleman
- Department of Nutrition, University of North Carolina School of Public Health, Chapel Hill, NC 27599
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229
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Yang X, Ma Y, Li N, Cai H, Bartlett MG. Development of a Method for the Determination of Acyl-CoA Compounds by Liquid Chromatography Mass Spectrometry to Probe the Metabolism of Fatty Acids. Anal Chem 2017; 89:813-821. [PMID: 27990799 PMCID: PMC5679003 DOI: 10.1021/acs.analchem.6b03623] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Acyl-Coenzyme As (acyl-CoAs) are a group of activated fatty acid molecules participating in multiple cellular processes including lipid synthesis, oxidative metabolism of fatty acids to produce ATP, transcriptional regulation, and protein post-translational modification. Quantification of cellular acyl-CoAs is challenging due to their instability in aqueous solutions and lack of blank matrices. Here we demonstrate an LC-MS/MS analytical method which allows for absolute quantitation with broad coverage of cellular acyl-CoAs. This assay was applied to profile endogenous acyl-CoAs under the challenge of a variety of dietary fatty acids in prostate and hepatic cells. Additionally, this approach allowed for detection of multiple fatty acid metabolic processes including the biogenesis of acyl-CoAs, and their elongation, degradation, and desaturation. Hierarchical clustering in the remodeling of acyl-CoA profiles revealed a fatty-acid-specific pattern across all tested cell lines, which provides a valuable reference for making predictions in other cell models. Individual acyl-CoAs were identified which were altered differentially by exogenous fatty acids in divergent tumorigenicity states of cells. These findings demonstrate the power of acyl-CoA profiling toward understanding the mechanisms for the progression of tumors or other diseases in response to fatty acids.
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Affiliation(s)
- Xiangkun Yang
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 250 W. Green Street, Athens, Georgia, 30602, United States
| | - Yongjie Ma
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 250 W. Green Street, Athens, Georgia, 30602, United States
| | - Ning Li
- Department of Analytical Chemistry, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, 110016, China
| | - Houjian Cai
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 250 W. Green Street, Athens, Georgia, 30602, United States
| | - Michael G. Bartlett
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 250 W. Green Street, Athens, Georgia, 30602, United States
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230
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Argus JP, Yu AK, Wang ES, Williams KJ, Bensinger SJ. An optimized method for measuring fatty acids and cholesterol in stable isotope-labeled cells. J Lipid Res 2016; 58:460-468. [PMID: 27974366 DOI: 10.1194/jlr.d069336] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 12/12/2016] [Indexed: 11/20/2022] Open
Abstract
Stable isotope labeling has become an important methodology for determining lipid metabolic parameters of normal and neoplastic cells. Conventional methods for fatty acid and cholesterol analysis have one or more issues that limit their utility for in vitro stable isotope-labeling studies. To address this, we developed a method optimized for measuring both fatty acids and cholesterol from small numbers of stable isotope-labeled cultured cells. We demonstrate quantitative derivatization and extraction of fatty acids from a wide range of lipid classes using this approach. Importantly, cholesterol is also recovered, albeit at a modestly lower yield, affording the opportunity to quantitate both cholesterol and fatty acids from the same sample. Although we find that background contamination can interfere with quantitation of certain fatty acids in low amounts of starting material, our data indicate that this optimized method can be used to accurately measure mass isotopomer distributions for cholesterol and many fatty acids isolated from small numbers of cultured cells. Application of this method will facilitate acquisition of lipid parameters required for quantifying flux and provide a better understanding of how lipid metabolism influences cellular function.
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Affiliation(s)
- Joseph P Argus
- Departments of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Amy K Yu
- Departments of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Eric S Wang
- Departments of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Kevin J Williams
- Departments of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Steven J Bensinger
- Departments of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095 .,Departments of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
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231
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Singh AB, Liu J. Identification of Hepatic Lysophosphatidylcholine Acyltransferase 3 as a Novel Target Gene Regulated by Peroxisome Proliferator-activated Receptor δ. J Biol Chem 2016; 292:884-897. [PMID: 27913621 DOI: 10.1074/jbc.m116.743575] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 11/29/2016] [Indexed: 12/31/2022] Open
Abstract
Peroxisome proliferator-activated receptor δ (PPARδ) regulates many genes involved in lipid metabolism. Hepatic lysophosphatidylcholine acyltransferase 3 (LPCAT3) has critical functions in triglycerides transport and endoplasmic reticulum stress response due to its unique ability to catalyze the incorporation of polyunsaturated fatty acids into phospholipids. Previous studies identified liver X receptor as the transcription factor controlling LPCAT3 expression in mouse liver tissue. Here we show that the hepatic LPCAT3 gene is transcriptionally regulated by PPARδ. Adenovirus-mediated knockdown of PPARδ in cultured hepatic cells and liver tissue reduced LPCAT3 mRNA levels, and exogenous overexpression of PPARδ increased LPCAT3 mRNA expression. Activation of PPARδ in HepG2, Huh7, and Hepa 1-6 cells with its specific agonists increased LPCAT3 mRNA levels in all three hepatic cell lines. Through conducting sequence analysis, LPCAT3 promoter assays, and direct DNA binding assays, we have mapped the functional PPAR-responsive element to a proximal region from -135 to -123 of the LPCAT3 promoter that plays an essential role in mediating PPARδ-induced transactivation of the LPCAT3 gene. Finally, we have provided in vivo evidence showing that activation of PPARδ by agonist L165041 in mice increased hepatic LPCAT3 mRNA abundance and LPCAT enzymatic activity, which is associated with increased incorporations of arachidonate into liver phosphatidylcholine and phosphatidylethanolamine. Furthermore, transient liver-specific knockdown of LPCAT3 in mice affected PPARδ-mediated activation of several hepatic genes involving in FA metabolism. Altogether, our new findings identify LPCAT3 as a direct PPARδ target gene and suggest a novel function of PPARδ in regulation of phospholipid metabolism through LPCAT3.
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Affiliation(s)
- Amar Bahadur Singh
- From the Department of Veterans Affairs Palo Alto Health Care System, Palo Alto, California 94304
| | - Jingwen Liu
- From the Department of Veterans Affairs Palo Alto Health Care System, Palo Alto, California 94304
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232
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Liver-specific ATP-citrate lyase inhibition by bempedoic acid decreases LDL-C and attenuates atherosclerosis. Nat Commun 2016; 7:13457. [PMID: 27892461 PMCID: PMC5133702 DOI: 10.1038/ncomms13457] [Citation(s) in RCA: 271] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 10/06/2016] [Indexed: 12/25/2022] Open
Abstract
Despite widespread use of statins to reduce low-density lipoprotein cholesterol (LDL-C) and associated atherosclerotic cardiovascular risk, many patients do not achieve sufficient LDL-C lowering due to muscle-related side effects, indicating novel treatment strategies are required. Bempedoic acid (ETC-1002) is a small molecule intended to lower LDL-C in hypercholesterolemic patients, and has been previously shown to modulate both ATP-citrate lyase (ACL) and AMP-activated protein kinase (AMPK) activity in rodents. However, its mechanism for LDL-C lowering, efficacy in models of atherosclerosis and relevance in humans are unknown. Here we show that ETC-1002 is a prodrug that requires activation by very long-chain acyl-CoA synthetase-1 (ACSVL1) to modulate both targets, and that inhibition of ACL leads to LDL receptor upregulation, decreased LDL-C and attenuation of atherosclerosis, independently of AMPK. Furthermore, we demonstrate that the absence of ACSVL1 in skeletal muscle provides a mechanistic basis for ETC-1002 to potentially avoid the myotoxicity associated with statin therapy.
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233
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Camell C, Goldberg E, Dixit VD. Regulation of Nlrp3 inflammasome by dietary metabolites. Semin Immunol 2016; 27:334-42. [PMID: 26776831 DOI: 10.1016/j.smim.2015.10.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Revised: 10/14/2015] [Accepted: 10/19/2015] [Indexed: 12/21/2022]
Abstract
The bidirectional communication between innate immune cells and energy metabolism is now widely appreciated to regulate homeostasis as well as chronic diseases that emerge from dysregulated inflammation. Macronutrients-derived from diet or endogenous pathways that generate and divert metabolites into energetic or biosynthetic pathways – regulate the initiation, duration and cessation of the inflammatory response. The NLRP3 inflammasome is an important innate sensor of structurally diverse metabolic damage-associated molecular patterns (DAMPs) that has been implicated in a wide range of inflammatory disorders associated with caloric excess, adiposity and aging. Understanding the regulators of immune-metabolic interactions and their contribution towards chronic disease mechanisms, therefore, has the potential to reduce disease pathology, improve quality of life in elderly and promote the extension of healthspan. Just as specialized subsets of immune cells dampen inflammation through the production of negative regulatory cytokines; specific immunoregulatory metabolites can deactivate inflammasome-mediated immune activation. Here, we highlight the role of energy substrates, alternative fuels and metabolic DAMPs in the regulation of the NLRP3 inflammasome and discuss potential dietary interventions that may impact sterile inflammatory disease.
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234
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Zlobine I, Gopal K, Ussher JR. Lipotoxicity in obesity and diabetes-related cardiac dysfunction. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1555-68. [DOI: 10.1016/j.bbalip.2016.02.011] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 02/15/2016] [Indexed: 12/11/2022]
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235
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Heimann E, Nyman M, Pålbrink AK, Lindkvist-Petersson K, Degerman E. Branched short-chain fatty acids modulate glucose and lipid metabolism in primary adipocytes. Adipocyte 2016; 5:359-368. [PMID: 27994949 PMCID: PMC5160390 DOI: 10.1080/21623945.2016.1252011] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/14/2016] [Accepted: 10/18/2016] [Indexed: 02/08/2023] Open
Abstract
Short-chain fatty acids (SCFAs), e.g. acetic acid, propionic acid and butyric acid, generated through colonic fermentation of dietary fibers, have been shown to reach the systemic circulation at micromolar concentrations. Moreover, SCFAs have been conferred anti-obesity properties in both animal models and human subjects. Branched SCFAs (BSCFAs), e.g., isobutyric and isovaleric acid, are generated by fermentation of branched amino acids, generated from undigested protein reaching colon. However, BSCFAs have been sparsely investigated when referring to effects on energy metabolism. Here we primarily investigate the effects of isobutyric acid and isovaleric acid on glucose and lipid metabolism in primary rat and human adipocytes. BSCFAs inhibited both cAMP-mediated lipolysis and insulin-stimulated de novo lipogenesis at 10 mM, whereas isobutyric acid potentiated insulin-stimulated glucose uptake by all concentrations (1, 3 and 10 mM) in rat adipocytes. For human adipocytes, only SCFAs inhibited lipolysis at 10 mM. In both in vitro models, BSCFAs and SCFAs reduced phosphorylation of hormone sensitive lipase, a rate limiting enzyme in lipolysis. In addition, BSCFAs and SCFAs, in contrast to insulin, inhibited lipolysis in the presence of wortmannin, a phosphatidylinositide 3-kinase inhibitor and OPC3911, a phosphodiesterase 3 inhibitor in rat adipocytes. Furthermore, BSCFAs and SCFAs reduced insulin-mediated phosphorylation of protein kinase B. To conclude, BSCFAs have effects on adipocyte lipid and glucose metabolism that can contribute to improved insulin sensitivity in individuals with disturbed metabolism.
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236
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Lipid metabolism in Rhodnius prolixus: Lessons from the genome. Gene 2016; 596:27-44. [PMID: 27697616 DOI: 10.1016/j.gene.2016.09.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 09/22/2016] [Accepted: 09/28/2016] [Indexed: 01/01/2023]
Abstract
The kissing bug Rhodnius prolixus is both an important vector of Chagas' disease and an interesting model for investigation into the field of physiology, including lipid metabolism. The publication of this insect genome will bring a huge amount of new molecular biology data to be used in future experiments. Although this work represents a promising scenario, a preliminary analysis of the sequence data is necessary to identify and annotate the genes involved in lipid metabolism. Here, we used bioinformatics tools and gene expression analysis to explore genes from different genes families and pathways, including genes for fat breakdown, as lipases and phospholipases, and enzymes from β-oxidation, fatty acid metabolism, and acyl-CoA and glycerolipid synthesis. The R. prolixus genome encodes 31 putative lipase genes, including 21 neutral lipases and 5 acid lipases. The expression profiles of some of these genes were analyzed. We were able to identify nine phospholipase A2 genes. A variety of gene families that participate in fatty acid synthesis and modification were studied, including fatty acid synthase, elongase, desaturase and reductase. Concerning the synthesis of glycerolipids, we found a second isoform of glycerol-3-phosphate acyltransferase that was ubiquitously expressed throughout the organs. Finally, all genes involved in fatty acid β-oxidation were identified, but not a long-chain acyl-CoA dehydrogenase. These results provide fundamental data to be used in future research on insect lipid metabolism and its possible relevance to Chagas' disease transmission.
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237
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Shimura M, Shindou H, Szyrwiel L, Tokuoka SM, Hamano F, Matsuyama S, Okamoto M, Matsunaga A, Kita Y, Ishizaka Y, Yamauchi K, Kohmura Y, Lobinski R, Shimizu I, Shimizu T. Imaging of intracellular fatty acids by scanning X-ray fluorescence microscopy. FASEB J 2016; 30:4149-4158. [PMID: 27601443 PMCID: PMC5102126 DOI: 10.1096/fj.201600569r] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 08/22/2016] [Indexed: 12/15/2022]
Abstract
Fatty acids are taken up by cells and incorporated into complex lipids such as neutral lipids and glycerophospholipids. Glycerophospholipids are major constituents of cellular membranes. More than 1000 molecular species of glycerophospholipids differ in their polar head groups and fatty acid compositions. They are related to cellular functions and diseases and have been well analyzed by mass spectrometry. However, intracellular imaging of fatty acids and glycerophospholipids has not been successful due to insufficient resolution using conventional methods. Here, we developed a method for labeling fatty acids with bromine (Br) and applied scanning X-ray fluorescence microscopy (SXFM) to obtain intracellular Br mapping data with submicrometer resolution. Mass spectrometry showed that cells took up Br-labeled fatty acids and metabolized them mainly into glycerophospholipids in CHO cells. Most Br signals observed by SXFM were in the perinuclear region. Higher resolution revealed a spot-like distribution of Br in the cytoplasm. The current method enabled successful visualization of intracellular Br-labeled fatty acids. Single-element labeling combined with SXFM technology facilitates the intracellular imaging of fatty acids, which provides a new tool to determine dynamic changes in fatty acids and their derivatives at the single-cell level.—Shimura, M., Shindou, H., Szyrwiel, L., Tokuoka, S. M., Hamano, F., Matsuyama, S., Okamoto, M., Matsunaga, A., Kita, Y., Ishizaka, Y., Yamauchi, K., Kohmura, Y., Lobinski, R., Shimizu, I., Shimizu, T. Imaging of intracellular fatty acids by scanning X-ray fluorescence microscopy.
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Affiliation(s)
- Mari Shimura
- Department of Intractable Diseases National Center for Global Health and Medicine, Tokyo, Japan; .,Riken SPring-8 Center, Hyogo, Japan
| | - Hideo Shindou
- Lipid Signaling, Research Institute, National Center for Global Health and Medicine, Tokyo Japan; .,Agency for Medical Research and Development-Core Research for Evolutionary Science and Technology (AMED-CREST), Tokyo, Japan
| | - Lukasz Szyrwiel
- Riken SPring-8 Center, Hyogo, Japan.,Centre National de la Recherche Scientifique/University of Pau and Pays de l'Adour (CNRS/UPPA), Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement (LCABIE), Unité Mixte de Recherche 5254, Pau, France.,Department of Chemistry of Drugs, Wroclaw Medical University, Wroclaw, Poland
| | - Suzumi M Tokuoka
- Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Fumie Hamano
- Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Life Sciences Core Facility, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Satoshi Matsuyama
- Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, Osaka, Japan; and
| | - Mayumi Okamoto
- Research Institute for Science and Engineering, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Akihiro Matsunaga
- Department of Intractable Diseases National Center for Global Health and Medicine, Tokyo, Japan
| | - Yoshihiro Kita
- Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Life Sciences Core Facility, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yukihito Ishizaka
- Department of Intractable Diseases National Center for Global Health and Medicine, Tokyo, Japan
| | - Kazuto Yamauchi
- Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, Osaka, Japan; and
| | | | - Ryszard Lobinski
- Centre National de la Recherche Scientifique/University of Pau and Pays de l'Adour (CNRS/UPPA), Laboratoire de Chimie Analytique, Bio-Inorganique et Environnement (LCABIE), Unité Mixte de Recherche 5254, Pau, France
| | - Isao Shimizu
- Research Institute for Science and Engineering, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Takao Shimizu
- Lipid Signaling, Research Institute, National Center for Global Health and Medicine, Tokyo Japan.,Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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238
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SCAP/SREBP pathway is required for the full steroidogenic response to cyclic AMP. Proc Natl Acad Sci U S A 2016; 113:E5685-93. [PMID: 27601673 DOI: 10.1073/pnas.1611424113] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Luteinizing hormone (LH) stimulates steroidogenesis largely through a surge in cyclic AMP (cAMP). Steroidogenic rates are also critically dependent on the availability of cholesterol at mitochondrial sites of synthesis. This cholesterol is provided by cellular uptake of lipoproteins, mobilization of intracellular lipid, and de novo synthesis. Whether and how these pathways are coordinated by cAMP are poorly understood. Recent phosphoproteomic analyses of cAMP-dependent phosphorylation sites in MA10 Leydig cells suggested that cAMP regulates multiple steps in these processes, including activation of the SCAP/SREBP pathway. SCAP [sterol-regulatory element-binding protein (SREBP) cleavage-activating protein] acts as a cholesterol sensor responsible for regulating intracellular cholesterol balance. Its role in cAMP-mediated control of steroidogenesis has not been explored. We used two CRISPR (clustered regularly interspaced short palindromic repeat)-Cas9 (CRISPR associated protein 9) knockout approaches to test the role of SCAP in steroidogenesis. Our results demonstrate that SCAP is required for progesterone production induced by concurrent inhibition of the cAMP phosphodiesterases PDE4 and PDE8. These inhibitors increased SCAP phosphorylation, SREBP2 activation, and subsequent expression of cholesterol biosynthetic genes, whereas SCAP deficiency largely prevented these effects. Reexpression of SCAP in SCAP-deficient cells restored SREBP2 protein expression and partially restored steroidogenic responses, confirming the requirement of SCAP-SREBP2 in steroidogenesis. Inhibitors of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase and isoprenylation attenuated, whereas exogenously provided cholesterol augmented, PDE inhibitor-induced steroidogenesis, suggesting that the cholesterol substrate needed for steroidogenesis is provided by both de novo synthesis and isoprenylation-dependent mechanisms. Overall, these results demonstrate a novel role for LH/cAMP in SCAP/SREBP activation and subsequent regulation of steroidogenesis.
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239
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Füllekrug J, Poppelreuther M. Measurement of Long-Chain Fatty Acyl-CoA Synthetase Activity. Methods Mol Biol 2016; 1376:43-53. [PMID: 26552674 DOI: 10.1007/978-1-4939-3170-5_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Long-chain fatty acyl-CoA synthetases (ACS) are a family of essential enzymes of lipid metabolism, activating fatty acids by thioesterification with coenzyme A. Fatty acyl-CoA molecules are then readily utilized for the biosynthesis of storage and membrane lipids, or for the generation of energy by ß-oxidation. Acyl-CoAs also function as transcriptional activators, allosteric inhibitors, or precursors for inflammatory mediators. Recent work suggests that ACS enzymes may drive cellular fatty acid uptake by metabolic trapping, and may also regulate the channeling of fatty acids towards specific metabolic pathways. The implication of ACS enzymes in widespread lipid associated diseases like type 2 diabetes has rekindled interest in this protein family. Here, we describe in detail how to measure long-chain fatty acyl-CoA synthetase activity by a straightforward radiometric assay. Cell lysates are incubated with ATP, coenzyme A, Mg(2+), and radiolabeled fatty acid bound to BSA. Differential phase partitioning of fatty acids and acyl-CoAs is exploited to quantify the amount of generated acyl-CoA by scintillation counting. The high sensitivity of this assay also allows the analysis of small samples like patient biopsies.
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Affiliation(s)
- Joachim Füllekrug
- Molecular Cell Biology Laboratory Internal Medicine IV, Heidelberg University Hospital, Otto-Meyerhof-Zentrum, University of Heidelberg, Im Neuenheimer Feld 350, 69120, Heidelberg, Germany.
| | - Margarete Poppelreuther
- Molecular Cell Biology Laboratory Internal Medicine IV, Heidelberg University Hospital, Otto-Meyerhof-Zentrum, University of Heidelberg, Im Neuenheimer Feld 350, 69120, Heidelberg, Germany
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240
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Identification of ACSL4 as a biomarker and contributor of ferroptosis. Biochem Biophys Res Commun 2016; 478:1338-43. [PMID: 27565726 DOI: 10.1016/j.bbrc.2016.08.124] [Citation(s) in RCA: 606] [Impact Index Per Article: 75.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 08/22/2016] [Indexed: 02/07/2023]
Abstract
Ferroptosis, a recently identified form of non-apoptotic cell death, is involved in several physiological and pathological processes. Although lipid peroxidation plays a central role in triggering ferroptosis, the essential regulator of lipid metabolism in ferroptosis remains poorly defined. Here, we show that acyl-CoA synthetase long-chain family member 4 (ACSL4) is required for ferroptotic cancer cell death. Compared with ferroptosis-sensitive cells (e.g., HepG2 and HL60), the expression of ACSL4 was remarkably downregulated in ferroptosis-resistant cells (e.g., LNCaP and K562). In contrast, the expression of other ACSLs, including ACSL1, ACSL3, ACSL5, and ACSL6, did not correlate with ferroptosis sensitivity. Moreover, knockdown of ACSL4 by specific shRNA inhibited erastin-induced ferroptosis in HepG2 and HL60 cells, whereas overexpression of ACSL4 by gene transfection restored sensitivity of LNCaP and K562 cells to erastin. Mechanically, ACSL4-mediated production of 5-hydroxyeicosatetraenoic acid (5-HETE) contributed to ferroptosis. Pharmacological inhibition of 5-HETE production by zileuton limited ACSL4 overexpression-induced ferroptosis. Collectively, these results indicate that ACSL4 is not only a sensitive monitor of ferroptosis, but also an important contributor of ferroptosis.
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241
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C13orf31 (FAMIN) is a central regulator of immunometabolic function. Nat Immunol 2016; 17:1046-56. [PMID: 27478939 DOI: 10.1038/ni.3532] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 07/01/2016] [Indexed: 12/15/2022]
Abstract
Single-nucleotide variations in C13orf31 (LACC1) that encode p.C284R and p.I254V in a protein of unknown function (called 'FAMIN' here) are associated with increased risk for systemic juvenile idiopathic arthritis, leprosy and Crohn's disease. Here we set out to identify the biological mechanism affected by these coding variations. FAMIN formed a complex with fatty acid synthase (FASN) on peroxisomes and promoted flux through de novo lipogenesis to concomitantly drive high levels of fatty-acid oxidation (FAO) and glycolysis and, consequently, ATP regeneration. FAMIN-dependent FAO controlled inflammasome activation, mitochondrial and NADPH-oxidase-dependent production of reactive oxygen species (ROS), and the bactericidal activity of macrophages. As p.I254V and p.C284R resulted in diminished function and loss of function, respectively, FAMIN determined resilience to endotoxin shock. Thus, we have identified a central regulator of the metabolic function and bioenergetic state of macrophages that is under evolutionary selection and determines the risk of inflammatory and infectious disease.
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242
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Padanad MS, Konstantinidou G, Venkateswaran N, Melegari M, Rindhe S, Mitsche M, Yang C, Batten K, Huffman KE, Liu J, Tang X, Rodriguez-Canales J, Kalhor N, Shay JW, Minna JD, McDonald J, Wistuba II, DeBerardinis RJ, Scaglioni PP. Fatty Acid Oxidation Mediated by Acyl-CoA Synthetase Long Chain 3 Is Required for Mutant KRAS Lung Tumorigenesis. Cell Rep 2016; 16:1614-1628. [PMID: 27477280 DOI: 10.1016/j.celrep.2016.07.009] [Citation(s) in RCA: 191] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 05/24/2016] [Accepted: 07/01/2016] [Indexed: 12/28/2022] Open
Abstract
KRAS is one of the most commonly mutated oncogenes in human cancer. Mutant KRAS aberrantly regulates metabolic networks. However, the contribution of cellular metabolism to mutant KRAS tumorigenesis is not completely understood. We report that mutant KRAS regulates intracellular fatty acid metabolism through Acyl-coenzyme A (CoA) synthetase long-chain family member 3 (ACSL3), which converts fatty acids into fatty Acyl-CoA esters, the substrates for lipid synthesis and β-oxidation. ACSL3 suppression is associated with depletion of cellular ATP and causes the death of lung cancer cells. Furthermore, mutant KRAS promotes the cellular uptake, retention, accumulation, and β-oxidation of fatty acids in lung cancer cells in an ACSL3-dependent manner. Finally, ACSL3 is essential for mutant KRAS lung cancer tumorigenesis in vivo and is highly expressed in human lung cancer. Our data demonstrate that mutant KRAS reprograms lipid homeostasis, establishing a metabolic requirement that could be exploited for therapeutic gain.
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Affiliation(s)
- Mahesh S Padanad
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Georgia Konstantinidou
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Niranjan Venkateswaran
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Margherita Melegari
- Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Smita Rindhe
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Matthew Mitsche
- McDermott Center for Human Growth and Development, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Molecular Genetics, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chendong Yang
- Children's Medical Center Research Institute, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kimberly Batten
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kenneth E Huffman
- Hamon Center for Therapeutic Oncology Research, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jingwen Liu
- Department of Veterans Affairs, Palo Alto Health Care System, Palo Alto, CA 94304, USA
| | - Ximing Tang
- Department of Translational Molecular Pathology, MD Anderson Cancer Center, The University of Texas, Houston, TX 7030, USA
| | - Jaime Rodriguez-Canales
- Department of Translational Molecular Pathology, MD Anderson Cancer Center, The University of Texas, Houston, TX 7030, USA
| | - Neda Kalhor
- Department of Translational Molecular Pathology, MD Anderson Cancer Center, The University of Texas, Houston, TX 7030, USA
| | - Jerry W Shay
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - John D Minna
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Hamon Center for Therapeutic Oncology Research, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jeffrey McDonald
- Department of Molecular Genetics, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ignacio I Wistuba
- Department of Pathology, MD Anderson Cancer Center, The University of Texas, Houston, TX 7030, USA; Departments of Translational Molecular Pathology and Thoracic/Head and Neck Medical Oncology, MD Anderson Cancer Center, The University of Texas, Houston, TX 7030, USA
| | - Ralph J DeBerardinis
- McDermott Center for Human Growth and Development, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Children's Medical Center Research Institute, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Pier Paolo Scaglioni
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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243
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Abstract
The remarkable plasticity and plethora of biological functions performed by macrophages have enticed scientists to study these cells in relation to atherosclerosis for >50 years, and major discoveries continue to be made today. It is now understood that macrophages play important roles in all stages of atherosclerosis, from initiation of lesions and lesion expansion, to necrosis leading to rupture and the clinical manifestations of atherosclerosis, to resolution and regression of atherosclerotic lesions. Lesional macrophages are derived primarily from blood monocytes, although recent research has shown that lesional macrophage-like cells can also be derived from smooth muscle cells. Lesional macrophages take on different phenotypes depending on their environment and which intracellular signaling pathways are activated. Rather than a few distinct populations of macrophages, the phenotype of the lesional macrophage is more complex and likely changes during the different phases of atherosclerosis and with the extent of lipid and cholesterol loading, activation by a plethora of receptors, and metabolic state of the cells. These different phenotypes allow the macrophage to engulf lipids, dead cells, and other substances perceived as danger signals; efflux cholesterol to high-density lipoprotein; proliferate and migrate; undergo apoptosis and death; and secrete a large number of inflammatory and proresolving molecules. This review article, part of the Compendium on Atherosclerosis, discusses recent advances in our understanding of lesional macrophage phenotype and function in different stages of atherosclerosis. With the increasing understanding of the roles of lesional macrophages, new research areas and treatment strategies are beginning to emerge.
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Affiliation(s)
- Ira Tabas
- From the Departments of Medicine (I.T.), Anatomy and Cell Biology (I.T.), and Physiology and Cellular Biophysics (I.T.), Columbia University, New York; and the Department of Medicine, Division of Metabolism, Endocrinology, and Nutrition (K.E.B.) and Department of Pathology (K.E.B.), UW Diabetes Institute, University of Washington School of Medicine, Seattle
| | - Karin E Bornfeldt
- From the Departments of Medicine (I.T.), Anatomy and Cell Biology (I.T.), and Physiology and Cellular Biophysics (I.T.), Columbia University, New York; and the Department of Medicine, Division of Metabolism, Endocrinology, and Nutrition (K.E.B.) and Department of Pathology (K.E.B.), UW Diabetes Institute, University of Washington School of Medicine, Seattle.
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244
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Andersen MK, Jørsboe E, Sandholt CH, Grarup N, Jørgensen ME, Færgeman NJ, Bjerregaard P, Pedersen O, Moltke I, Hansen T, Albrechtsen A. Identification of Novel Genetic Determinants of Erythrocyte Membrane Fatty Acid Composition among Greenlanders. PLoS Genet 2016; 12:e1006119. [PMID: 27341449 PMCID: PMC4920407 DOI: 10.1371/journal.pgen.1006119] [Citation(s) in RCA: 20] [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: 01/19/2016] [Accepted: 05/20/2016] [Indexed: 11/25/2022] Open
Abstract
Fatty acids (FAs) are involved in cellular processes important for normal body function, and perturbation of FA balance has been linked to metabolic disturbances, including type 2 diabetes. An individual’s level of FAs is affected by diet, lifestyle, and genetic variation. We aimed to improve the understanding of the mechanisms and pathways involved in regulation of FA tissue levels, by identifying genetic loci associated with inter-individual differences in erythrocyte membrane FA levels. We assessed the levels of 22 FAs in the phospholipid fraction of erythrocyte membranes from 2,626 Greenlanders in relation to single nucleotide polymorphisms genotyped on the MetaboChip or imputed. We identified six independent association signals. Novel loci were identified on chromosomes 5 and 11 showing strongest association with oleic acid (rs76430747 in ACSL6, beta (SE): -0.386% (0.034), p = 1.8x10-28) and docosahexaenoic acid (rs6035106 in DTD1, 0.137% (0.025), p = 6.4x10-8), respectively. For a missense variant (rs80356779) in CPT1A, we identified a number of novel FA associations, the strongest with 11-eicosenoic acid (0.473% (0.035), p = 2.6x10-38), and for variants in FADS2 (rs174570), LPCAT3 (rs2110073), and CERS4 (rs11881630) we replicated known FA associations. Moreover, we observed metabolic implications of the ACSL6 (rs76430747) and CPT1A (rs80356779) variants, which both were associated with altered HbA1c (0.051% (0.013), p = 5.6x10-6 and -0.034% (0.016), p = 3.1x10-4, respectively). The latter variant was also associated with reduced insulin resistance (HOMA-IR, -0.193 (0.050), p = 3.8x10-6), as well as measures of smaller body size, including weight (-2.676 kg (0.523), p = 2.4x10-7), lean mass (-1.200 kg (0.271), p = 1.7x10-6), height (-0.966 cm (0.230), p = 2.0x10-5), and BMI (-0.638 kg/m2 (0.181), p = 2.8x10-4). In conclusion, we have identified novel genetic determinants of FA composition in phospholipids in erythrocyte membranes, and have shown examples of links between genetic variants associated with altered FA membrane levels and changes in metabolic traits. Disruption of fatty-acid balance has in several previous studies been linked to human health conditions, including the metabolic syndrome, type 2 diabetes, and insulin resistance. Composition of fatty acids in lipid membranes is influenced, not only by diet and lifestyle, but also by genetic variation. By identifying genes linked to changes in the level of specific fatty acids, it may be possible to identify biological mechanisms and pathways central to regulation of fatty-acid composition in lipid membranes. We therefore aimed at finding such genes by studying Greenlanders. We identified six genomic regions harboring variants, which were associated with the level of at least one of 22 assessed erythrocyte membrane fatty acids, including two novel regions not previously linked to fatty acid levels. Moreover, we showed that two of the identified variants were associated with altered levels of glycosylated hemoglobin, and one of these variants was associated with reduced insulin resistance and decreased measures of body size. These results contribute to our understanding of fatty acid metabolism, and support a link between fatty acid balance and metabolic health.
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Affiliation(s)
- Mette Korre Andersen
- Section for Metabolic Genetics, The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emil Jørsboe
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Camilla Helene Sandholt
- Section for Metabolic Genetics, The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Niels Grarup
- Section for Metabolic Genetics, The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Nils Joakim Færgeman
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Peter Bjerregaard
- National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark
- Greenland Centre for Health Research, University of Greenland, Nuuk, Greenland
| | - Oluf Pedersen
- Section for Metabolic Genetics, The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ida Moltke
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (IM); (TH); (AA)
| | - Torben Hansen
- Section for Metabolic Genetics, The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
- * E-mail: (IM); (TH); (AA)
| | - Anders Albrechtsen
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (IM); (TH); (AA)
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Ertunc ME, Hotamisligil GS. Lipid signaling and lipotoxicity in metaflammation: indications for metabolic disease pathogenesis and treatment. J Lipid Res 2016; 57:2099-2114. [PMID: 27330055 DOI: 10.1194/jlr.r066514] [Citation(s) in RCA: 303] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/20/2016] [Indexed: 12/19/2022] Open
Abstract
Lipids encompass a wide variety of molecules such as fatty acids, sterols, phospholipids, and triglycerides. These molecules represent a highly efficient energy resource and can act as structural elements of membranes or as signaling molecules that regulate metabolic homeostasis through many mechanisms. Cells possess an integrated set of response systems to adapt to stresses such as those imposed by nutrient fluctuations during feeding-fasting cycles. While lipids are pivotal for these homeostatic processes, they can also contribute to detrimental metabolic outcomes. When metabolic stress becomes chronic and adaptive mechanisms are overwhelmed, as occurs during prolonged nutrient excess or obesity, lipid influx can exceed the adipose tissue storage capacity and result in accumulation of harmful lipid species at ectopic sites such as liver and muscle. As lipid metabolism and immune responses are highly integrated, accumulation of harmful lipids or generation of signaling intermediates can interfere with immune regulation in multiple tissues, causing a vicious cycle of immune-metabolic dysregulation. In this review, we summarize the role of lipotoxicity in metaflammation at the molecular and tissue level, describe the significance of anti-inflammatory lipids in metabolic homeostasis, and discuss the potential of therapeutic approaches targeting pathways at the intersection of lipid metabolism and immune function.
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Affiliation(s)
- Meric Erikci Ertunc
- Department of Genetics and Complex Diseases and Sabri Ülker Center, Harvard T. H. Chan School of Public Health, Broad Institute of Harvard and Massachusetts Institute of Technology, Boston, MA 02115
| | - Gökhan S Hotamisligil
- Department of Genetics and Complex Diseases and Sabri Ülker Center, Harvard T. H. Chan School of Public Health, Broad Institute of Harvard and Massachusetts Institute of Technology, Boston, MA 02115
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246
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Kihara A. Synthesis and degradation pathways, functions, and pathology of ceramides and epidermal acylceramides. Prog Lipid Res 2016; 63:50-69. [PMID: 27107674 DOI: 10.1016/j.plipres.2016.04.001] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/08/2016] [Accepted: 04/20/2016] [Indexed: 10/21/2022]
Abstract
Ceramide (Cer) is a structural backbone of sphingolipids and is composed of a long-chain base and a fatty acid. Existence of a variety of Cer species, which differ in chain-length, hydroxylation status, and/or double bond number of either of their hydrophobic chains, has been reported. Ceramide is produced by Cer synthases. Mammals have six Cer synthases (CERS1-6), each of which exhibits characteristic substrate specificity toward acyl-CoAs with different chain-lengths. Knockout mice for each Cer synthase show corresponding, isozyme-specific phenotypes, revealing the functional differences of Cers with different chain-lengths. Cer diversity is especially prominent in epidermis. Changes in Cer levels, composition, and chain-lengths are associated with atopic dermatitis. Acylceramide (acyl-Cer) specifically exists in epidermis and plays an essential role in skin permeability barrier formation. Accordingly, defects in acyl-Cer synthesis cause the cutaneous disorder ichthyosis with accompanying severe skin barrier defects. Although the molecular mechanism by which acyl-Cer is generated was long unclear, most genes involved in its synthesis have been identified recently. In Cer degradation pathways, the long-chain base moiety of Cer is converted to acyl-CoA, which is then incorporated mainly into glycerophospholipids. This pathway generates the lipid mediator sphingosine 1-phosphate. This review will focus on recent advances in our understanding of the synthesis and degradation pathways, physiological functions, and pathology of Cers/acyl-Cers.
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Affiliation(s)
- Akio Kihara
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12-jo, Nishi 6-choume, Kita-ku, Sapporo 060-0812, Japan.
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247
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D'Aquila T, Hung YH, Carreiro A, Buhman KK. Recent discoveries on absorption of dietary fat: Presence, synthesis, and metabolism of cytoplasmic lipid droplets within enterocytes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:730-47. [PMID: 27108063 DOI: 10.1016/j.bbalip.2016.04.012] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 03/16/2016] [Accepted: 04/16/2016] [Indexed: 02/07/2023]
Abstract
Dietary fat provides essential nutrients, contributes to energy balance, and regulates blood lipid concentrations. These functions are important to health, but can also become dysregulated and contribute to diseases such as obesity, diabetes, cardiovascular disease, and cancer. Within enterocytes, the digestive products of dietary fat are re-synthesized into triacylglycerol, which is either secreted on chylomicrons or stored within cytoplasmic lipid droplets (CLDs). CLDs were originally thought to be inert stores of neutral lipids, but are now recognized as dynamic organelles that function in multiple cellular processes in addition to lipid metabolism. This review will highlight recent discoveries related to dietary fat absorption with an emphasis on the presence, synthesis, and metabolism of CLDs within this process.
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Affiliation(s)
- Theresa D'Aquila
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Yu-Han Hung
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Alicia Carreiro
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA.
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248
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Alves-Bezerra M, Klett EL, De Paula IF, Ramos IB, Coleman RA, Gondim KC. Long-chain acyl-CoA synthetase 2 knockdown leads to decreased fatty acid oxidation in fat body and reduced reproductive capacity in the insect Rhodnius prolixus. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:650-62. [PMID: 27091636 DOI: 10.1016/j.bbalip.2016.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/16/2016] [Accepted: 04/13/2016] [Indexed: 10/21/2022]
Abstract
Long-chain acyl-CoA esters are important intermediates in lipid metabolism and are synthesized from fatty acids by long-chain acyl-CoA synthetases (ACSL). The hematophagous insect Rhodnius prolixus, a vector of Chagas' disease, produces glycerolipids in the midgut after a blood meal, which are stored as triacylglycerol in the fat body and eggs. We identified twenty acyl-CoA synthetase genes in R. prolixus, two encoding ACSL isoforms (RhoprAcsl1 and RhoprAcsl2). RhoprAcsl1 transcripts increased in posterior midgut on the second day after feeding, and RhoprAcsl2 was highly transcribed on the tenth day. Both enzymes were expressed in Escherichia coli. Recombinant RhoprACSL1 and RhoprACSL2 had broad pH optima (7.5-9.5 and 6.5-9.5, respectively), were inhibited by triacsin C, and were rosiglitazone-insensitive. Both showed similar apparent Km for palmitic and oleic acid (2-6 μM), but different Km for arachidonic acid (0.5 and 6 μM for RhoprACSL1-Flag and RhoprACSL2-Flag, respectively). The knockdown of RhoprAcsl1 did not result in noticeable phenotypes. However, RhoprACSL2 deficient insects exhibited a 2.5-fold increase in triacylglycerol content in the fat body, and 90% decrease in fatty acid β-oxidation. RhoprAcsl2 knockdown also resulted in 20% increase in lifespan, delayed digestion, 30% reduced oviposition, and 50% reduction in egg hatching. Laid eggs and hatched nymphs showed remarkable alterations in morphology. In summary, R. prolixus ACSL isoforms have distinct roles on lipid metabolism. Although RhoprACSL1 functions remain unclear, we propose that RhoprACSL2 is the main contributor for the formation of the intracellular acyl-CoA pool channeled for β-oxidation in the fat body, and is also required for normal reproduction.
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Affiliation(s)
- Michele Alves-Bezerra
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Eric L Klett
- Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Iron F De Paula
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Isabela B Ramos
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Rosalind A Coleman
- Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Katia C Gondim
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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249
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Worth AJ, Marchione DM, Parry RC, Wang Q, Gillespie KP, Saillant NN, Sims C, Mesaros C, Snyder NW, Blair IA. LC-MS Analysis of Human Platelets as a Platform for Studying Mitochondrial Metabolism. J Vis Exp 2016:e53941. [PMID: 27077278 DOI: 10.3791/53941] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Perturbed mitochondrial metabolism has received renewed interest as playing a causative role in a range of diseases. Probing alterations to metabolic pathways requires a model in which external factors can be well controlled, allowing for reproducible and meaningful results. Many studies employ transformed cellular models for these purposes; however, metabolic reprogramming that occurs in many cancer cell lines may introduce confounding variables. For this reason primary cells are desirable, though attaining adequate biomass for metabolic studies can be challenging. Here we show that human platelets can be utilized as a platform to carry out metabolic studies in combination with liquid chromatography-tandem mass spectrometry analysis. This approach is amenable to relative quantification and isotopic labeling to probe the activity of specific metabolic pathways. Availability of platelets from individual donors or from blood banks makes this model system applicable to clinical studies and feasible to scale up. Here we utilize isolated platelets to confirm previously identified compensatory metabolic shifts in response to the complex I inhibitor rotenone. More specifically, a decrease in glycolysis is accompanied by an increase in fatty acid oxidation to maintain acetyl-CoA levels. Our results show that platelets can be used as an easily accessible and medically relevant model to probe the effects of xenobiotics on cellular metabolism.
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Affiliation(s)
- Andrew J Worth
- Center for Cancer Pharmacology, University of Pennsylvania; Center for Excellence in Environmental Toxicology, University of Pennsylvania
| | - Dylan M Marchione
- Center for Excellence in Environmental Toxicology, University of Pennsylvania; Penn SRP and Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania
| | - Robert C Parry
- Center for Cancer Pharmacology, University of Pennsylvania; Center for Excellence in Environmental Toxicology, University of Pennsylvania
| | - Qingqing Wang
- Center for Excellence in Environmental Toxicology, University of Pennsylvania; Penn SRP and Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania
| | - Kevin P Gillespie
- Center for Excellence in Environmental Toxicology, University of Pennsylvania; Penn SRP and Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania
| | - Noelle N Saillant
- Division of Traumatology, Department of Surgery, Critical Care and Acute Care Surgery, University of Pennsylvania
| | - Carrie Sims
- Division of Traumatology, Department of Surgery, Critical Care and Acute Care Surgery, University of Pennsylvania
| | - Clementina Mesaros
- Center for Cancer Pharmacology, University of Pennsylvania; Center for Excellence in Environmental Toxicology, University of Pennsylvania
| | | | - Ian A Blair
- Center for Cancer Pharmacology, University of Pennsylvania; Center for Excellence in Environmental Toxicology, University of Pennsylvania;
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250
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Recuero-Checa MA, Sharma M, Lau C, Watkins PA, Gaydos CA, Dean D. Chlamydia trachomatis growth and development requires the activity of host Long-chain Acyl-CoA Synthetases (ACSLs). Sci Rep 2016; 6:23148. [PMID: 26988341 PMCID: PMC4796813 DOI: 10.1038/srep23148] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/25/2016] [Indexed: 11/17/2022] Open
Abstract
The obligate-intracellular pathogen Chlamydia trachomatis (Ct) has undergone considerable genome reduction with consequent dependence on host biosynthetic pathways, metabolites and enzymes. Long-chain acyl-CoA synthetases (ACSLs) are key host-cell enzymes that convert fatty acids (FA) into acyl-CoA for use in metabolic pathways. Here, we show that the complete host ACSL family [ACSL1 and ACSL3-6] translocates into the Ct membrane-bound vacuole, termed inclusion, and remains associated with membranes of metabolically active forms of Ct throughout development. We discovered that three different pharmacologic inhibitors of ACSL activity independently impede Ct growth in a dose-dependent fashion. Using an FA competition assay, host ACSLs were found to activate Ct branched-chain FAs, suggesting that one function of the ACSLs is to activate Ct FAs and host FAs (recruited from the cytoplasm) within the inclusion. Because the ACSL inhibitors can deplete lipid droplets (LD), we used a cell line where LD synthesis was switched off to evaluate whether LD deficiency affects Ct growth. In these cells, we found no effect on growth or on translocation of ACSLs into the inclusion. Our findings support an essential role for ACSL activation of host-cell and bacterial FAs within the inclusion to promote Ct growth and development, independent of LDs.
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Affiliation(s)
- Maria A. Recuero-Checa
- Center for Immunobiology and Vaccine Development, UCSF Benioff Children’s Hospital Oakland Research Institute, Oakland, CA, 94609, USA
- Department of Infectious Disease, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Manu Sharma
- Center for Immunobiology and Vaccine Development, UCSF Benioff Children’s Hospital Oakland Research Institute, Oakland, CA, 94609, USA
| | - Constance Lau
- Center for Immunobiology and Vaccine Development, UCSF Benioff Children’s Hospital Oakland Research Institute, Oakland, CA, 94609, USA
| | - Paul A. Watkins
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Charlotte A. Gaydos
- Department of Infectious Disease, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Deborah Dean
- Center for Immunobiology and Vaccine Development, UCSF Benioff Children’s Hospital Oakland Research Institute, Oakland, CA, 94609, USA
- Department of Bioengineering, University of California at Berkeley and San Francisco, CA, USA
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