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Yang H, Gu W, Ni J, Ma Y, Li S, Neumann D, Ding X, Zhu L. Carnitine palmitoyl-transferase 1A is potentially involved in bovine herpesvirus 1 productive infection. Vet Microbiol 2024; 288:109932. [PMID: 38043447 PMCID: PMC10919102 DOI: 10.1016/j.vetmic.2023.109932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/21/2023] [Accepted: 11/26/2023] [Indexed: 12/05/2023]
Abstract
Bovine herpesvirus 1(BoHV-1) is an important bovine pathogen that causes great economic loss to cattle farms worldwide. The virus-productive infection in bovine kidney (MDBK) cells results in ATP depletion. The mechanisms are not well understood. Mitochondrial fatty acid β-oxidation (FAO) is an important energy source in many tissues with high energy demand. Since carnitine palmitoyl-transferase 1 A (CPT1A) is the rate-limiting enzyme of FAO, we investigated the interactions between virus-productive infection and CPT1A signaling. Here, we found that virus-productive infection at the later stage significantly decreased CPT1A protein levels in all the detected cells, including MDBK, A549, and Neuro-2A cells, differentially altered the accumulation of CPT1A proteins in the nucleus and cytosol, and re-localized the protein in the nucleus. Etomoxir (ETO), an irreversible inhibitor of CPT1A, inhibited viral replication and partially interfered with the ability of BoHV-1 to alter CPT1A accumulation in the nucleus but not in the cytosol. Furthermore, ETO consistently reduced RNA levels of two viral regulatory proteins (bICP0 and bICP22) and protein expression of virion-associated proteins during productive infection, further supporting the important roles of CPT1A signaling in BoHV-1 productive infection. These data, for the first time, suggest that CPT1A is potentially involved in BoHV-1 productive infection.
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Affiliation(s)
- Hao Yang
- College of Life Sciences, Hebei University, Baoding 071002, China
| | - Wenyuan Gu
- Center for Animal Diseases Control and Prevention of Hebei Province, Shijiazhuang 050035, China
| | - Junqing Ni
- Hebei Province Animal Husbandry and Improved Breeds Work Station, Shijiazhuang 050061, China
| | - Yabin Ma
- Hebei Province Animal Husbandry and Improved Breeds Work Station, Shijiazhuang 050061, China
| | - Shitao Li
- Department of Microbiology and Immunology, Tulane University, New Orleans, LA 70118, USA
| | - Donna Neumann
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 537006, USA
| | - Xiuyan Ding
- College of Life Sciences, Hebei University, Baoding 071002, China
| | - Liqian Zhu
- College of Life Sciences, Hebei University, Baoding 071002, China
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Bucheli OTM, Eyer K. Insights into the relationship between persistent antibody secretion and metabolic programming - A question for single-cell analysis. Immunol Lett 2023; 260:35-43. [PMID: 37315849 DOI: 10.1016/j.imlet.2023.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 04/28/2023] [Accepted: 06/10/2023] [Indexed: 06/16/2023]
Abstract
Vaccination aims to generate a protective and persisting antibody response. Indeed, humoral vaccine-mediated protection depends on the quality and quantity of the produced antigen-specific antibodies for its initial magnitude and the persistence of the plasma cells for its duration. Therefore, understanding the mechanisms behind the generation, selection and maintenance of long-lived plasma cells secreting protective antibodies is of fundamental importance for understanding long-term immunity, vaccine responses, therapeutical approaches for autoimmune disease and multiple myeloma. Recent studies have observed correlations between the generation, function and lifespan of plasma cells and their metabolism, with metabolism being both a main driver and primary consequence of changes in cellular behavior. This review introduces how metabolic programs influence and drive immune cell functions in general and plasma cell differentiation and longevity more specifically, summarizing the current knowledge on metabolic pathways and their influences on cellular fate. In addition, available technologies to profile metabolism and their limitations are discussed, leading to the unique and open technological challenges for further advancement of this research field.
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Affiliation(s)
- Olivia T M Bucheli
- Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, D-CHAB, ETH Zürich, 8093 Zürich, Switzerland
| | - Klaus Eyer
- Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, D-CHAB, ETH Zürich, 8093 Zürich, Switzerland.
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3
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Huang M, Coral D, Ardalani H, Spegel P, Saadat A, Claussnitzer M, Mulder H, Franks PW, Kalamajski S. Identification of a weight loss-associated causal eQTL in MTIF3 and the effects of MTIF3 deficiency on human adipocyte function. eLife 2023; 12:84168. [PMID: 36876906 PMCID: PMC10023155 DOI: 10.7554/elife.84168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/05/2023] [Indexed: 03/07/2023] Open
Abstract
Genetic variation at the MTIF3 (Mitochondrial Translational Initiation Factor 3) locus has been robustly associated with obesity in humans, but the functional basis behind this association is not known. Here, we applied luciferase reporter assay to map potential functional variants in the haplotype block tagged by rs1885988 and used CRISPR-Cas9 to edit the potential functional variants to confirm the regulatory effects on MTIF3 expression. We further conducted functional studies on MTIF3-deficient differentiated human white adipocyte cell line (hWAs-iCas9), generated through inducible expression of CRISPR-Cas9 combined with delivery of synthetic MTIF3-targeting guide RNA. We demonstrate that rs67785913-centered DNA fragment (in LD with rs1885988, r2 > 0.8) enhances transcription in a luciferase reporter assay, and CRISPR-Cas9-edited rs67785913 CTCT cells show significantly higher MTIF3 expression than rs67785913 CT cells. Perturbed MTIF3 expression led to reduced mitochondrial respiration and endogenous fatty acid oxidation, as well as altered expression of mitochondrial DNA-encoded genes and proteins, and disturbed mitochondrial OXPHOS complex assembly. Furthermore, after glucose restriction, the MTIF3 knockout cells retained more triglycerides than control cells. This study demonstrates an adipocyte function-specific role of MTIF3, which originates in the maintenance of mitochondrial function, providing potential explanations for why MTIF3 genetic variation at rs67785913 is associated with body corpulence and response to weight loss interventions.
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Affiliation(s)
- Mi Huang
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Clinical Research Centre, Lund UniversityMalmöSweden
| | - Daniel Coral
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Clinical Research Centre, Lund UniversityMalmöSweden
| | - Hamidreza Ardalani
- Department of Chemistry, Centre for Analysis and Synthesis, Lund UniversityLundSweden
| | - Peter Spegel
- Department of Chemistry, Centre for Analysis and Synthesis, Lund UniversityLundSweden
| | - Alham Saadat
- Metabolism Program, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Melina Claussnitzer
- Metabolism Program, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Hindrik Mulder
- Unit of Molecular Metabolism, Department of Clinical Sciences, Clinical Research Centre, Lund UniversityMalmöSweden
| | - Paul W Franks
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Clinical Research Centre, Lund UniversityMalmöSweden
- Department of Nutrition, Harvard T.H. Chan School of Public HealthBostonUnited States
| | - Sebastian Kalamajski
- Genetic and Molecular Epidemiology Unit, Department of Clinical Sciences, Clinical Research Centre, Lund UniversityMalmöSweden
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4
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Identification of Monocyte-Associated Genes Related to the Instability of Atherosclerosis Plaque. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:3972272. [PMID: 36187340 PMCID: PMC9519342 DOI: 10.1155/2022/3972272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/05/2022] [Accepted: 08/12/2022] [Indexed: 11/17/2022]
Abstract
Background. Atherosclerotic plaque instability is a common cause of stroke and ischemic infarction, and identification of monocyte-associated genes has become a prominent feature in cardiovascular research as a contributing/predictive marker. Methods. Whole genome sequencing data were downloaded from GSE159677, GSE41571, GSE120521, and GSE118481. Single-cell sequencing data analysis was conducted to cluster molecular subtypes of atherosclerotic plaques and identify specific genes. Differentially expressed genes (DEGs) between normal subjects and patients with unstable atheromatous plaques were screened. Weighted gene coexpression network analysis (WGCNA) was performed to find key module genes. In addition, GO and KEGG enrichment analyses explored potential biological signaling pathways to generate protein interaction (PPI) networks. GSEA and GSVA demonstrated activations in plaque instability subtypes. Results. 239 monocyte-associated genes were identified based on bulk and single-cell RNA-sequencing, followed by the recognition of 1221 atherosclerotic plaque-associated DEGs from the pooled matrix. GO and KEGG analyses suggested that DEGs might be related to inflammation response and the PI3K-Akt signaling pathway. Eight no-grey modules were obtained through WGCNA analysis, and the turquoise module has the highest correlation with unstable plaque (
), which contained 1323 module genes. After fetching the intersecting genes, CXCL3, FPR1, GK, and LST1 were obtained that were significantly associated with plaque instability, which had an intense specific interaction. Monocyte-associated genes associated with atherosclerotic plaque instability have certain diagnostic significance and are generally overexpressed in this patient population. In addition, 11 overlapping coexpressed genes (CEG) might also activated multiple pathways regulating inflammatory responses, platelet activation, and hypoxia-inducible factors. GSVA showed that the corresponding pathways were significantly activated in high expression samples. Conclusions. Overexpression of CXCL3, GK, FPR1, and LST1 was advanced recognition and intervention factors for unstable plaques, which might become targets for atherosclerosis rupture prevention. We also analyzed the potential mechanisms of CEG from inflammatory and oxidative stress pathways.
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Disturbance of Fatty Acid Metabolism Promoted Vascular Endothelial Cell Senescence via Acetyl-CoA-Induced Protein Acetylation Modification. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:1198607. [PMID: 35993026 PMCID: PMC9385365 DOI: 10.1155/2022/1198607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 06/27/2022] [Accepted: 07/01/2022] [Indexed: 11/18/2022]
Abstract
Endothelial cell senescence is the main risk factor contributing to vascular dysfunction and the progression of aging-related cardiovascular diseases. However, the relationship between endothelial cell metabolism and endothelial senescence remains unclear. The present study provides novel insight into fatty acid metabolism in the regulation of endothelial senescence. In the replicative senescence model and H2O2-induced premature senescence model of primary cultured human umbilical vein endothelial cells (HUVECs), fatty acid oxidation (FAO) was suppressed and fatty acid profile was disturbed, accompanied by downregulation of proteins associated with fatty acid uptake and mitochondrial entry, in particular the FAO rate-limiting enzyme carnitine palmitoyl transferase 1A (CPT1A). Impairment of fatty acid metabolism by silencing CPT1A or CPT1A inhibitor etomoxir facilitated the development of endothelial senescence, as implied by the increase of p53, p21, and senescence-associated β-galactosidase, as well as the decrease of EdU-positive proliferating cells. In the contrary, rescue of FAO by overexpression of CPT1A or supplement of short chain fatty acids (SCFAs) acetate and propionate ameliorated endothelial senescence. In vivo, treatment of acetate for 4 weeks lowered the blood pressure and alleviated the senescence-related phenotypes in aortas of Ang II-infused mice. Mechanistically, fatty acid metabolism regulates endothelial senescence via acetyl-coenzyme A (acetyl-CoA), as implied by the observations that suppression of acetyl-CoA production using the inhibitor of ATP citrate lyase NDI-091143 accelerated senescence of HUVECs and that supplementation of acetyl-CoA prevented H2O2-induced endothelial senescence. Deficiency of acetyl-CoA resulted in alteration of acetylated protein profiles which are associated with cell metabolism and cell cycle. These findings thus suggest that improvement of fatty acid metabolism might ameliorate endothelial senescence-associated cardiovascular diseases.
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Sakamuri SSVP, Sure VN, Kolli L, Liu N, Evans WR, Sperling JA, Busija DW, Wang X, Lindsey SH, Murfee WL, Mostany R, Katakam PVG. Glycolytic and Oxidative Phosphorylation Defects Precede the Development of Senescence in Primary Human Brain Microvascular Endothelial Cells. GeroScience 2022; 44:1975-1994. [PMID: 35378718 PMCID: PMC9616994 DOI: 10.1007/s11357-022-00550-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 03/19/2022] [Indexed: 11/24/2022] Open
Abstract
Alterations of mitochondrial and glycolytic energy pathways related to aging could contribute to cerebrovascular dysfunction. We studied the impact of aging on energetics of primary human brain microvascular endothelial cells (HBMECs) by comparing the young (passages 7-9), pre-senescent (passages 13-15), and senescent (passages 20-21) cells. Pre-senescent HBMECs displayed decreased telomere length and undetectable telomerase activity although markers of senescence were unaffected. Bioenergetics in HBMECs were determined by measuring the oxygen consumption (OCR) and extracellular acidification (ECAR) rates. Cellular ATP production in young HBMECs was predominantly dependent on glycolysis with glutamine as the preferred fuel for mitochondrial oxidative phosphorylation (OXPHOS). In contrast, pre-senescent HBMECs displayed equal contribution to ATP production rate from glycolysis and OXPHOS with equal utilization of glutamine, glucose, and fatty acids as mitofuels. Compared to young, pre-senescent HBMECs showed a lower overall ATP production rate that was characterized by diminished contribution from glycolysis. Impairments of glycolysis displayed by pre-senescent cells included reduced basal glycolysis, compensatory glycolysis, and non-glycolytic acidification. Furthermore, impairments of mitochondrial respiration in pre-senescent cells involved the reduction of maximal respiration and spare respiratory capacity but intact basal and ATP production-related OCR. Proton leak and non-mitochondrial respiration, however, were unchanged in the pre-senescent HBMECs. HBMECS at passages 20-21 displayed expression of senescence markers and continued similar defects in glycolysis and worsened OXPHOS. Thus, for the first time, we characterized the bioenergetics of pre-senescent HBMECs comprehensively to identify the alterations of the energy pathways that could contribute to aging.
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Affiliation(s)
- Siva S V P Sakamuri
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA.
| | - Venkata N Sure
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
| | - Lahari Kolli
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
| | - Ning Liu
- Neuroscience Program, Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA
- Clinical Neuroscience Research Center, 131 S. Robertson, Suite 1300, New Orleans, LA, 70112, USA
| | - Wesley R Evans
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
- Neuroscience Program, Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA
| | - Jared A Sperling
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
| | - David W Busija
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
- Neuroscience Program, Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA
| | - Xiaoying Wang
- Neuroscience Program, Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA
- Clinical Neuroscience Research Center, 131 S. Robertson, Suite 1300, New Orleans, LA, 70112, USA
| | - Sarah H Lindsey
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
- Neuroscience Program, Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA
| | - Walter L Murfee
- J. Clayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Ricardo Mostany
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
- Neuroscience Program, Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA
| | - Prasad V G Katakam
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA
- Neuroscience Program, Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA
- Clinical Neuroscience Research Center, 131 S. Robertson, Suite 1300, New Orleans, LA, 70112, USA
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7
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Di Modica M, Arlotta V, Sfondrini L, Tagliabue E, Triulzi T. The Link Between the Microbiota and HER2+ Breast Cancer: The New Challenge of Precision Medicine. Front Oncol 2022; 12:947188. [PMID: 35912227 PMCID: PMC9326166 DOI: 10.3389/fonc.2022.947188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 06/22/2022] [Indexed: 12/12/2022] Open
Abstract
The microbiota is emerging as a key player in cancer due to its involvement in several host physiological functions, including digestion, development of the immune system, and modulation of endocrine function. Moreover, its participation in the efficacy of anticancer treatments has been well described. For instance, the involvement of the breast microbiota in breast cancer (BC) development and progression has gained ground in the past several years. In this review, we report and discuss new findings on the impact of the gut and breast microbiota on BC, focusing on the HER2+ BC subtype, and the possibility of defining microbial signatures that are associated with disease aggressiveness, treatment response, and therapy toxicity. We also discuss novel insights into the mechanisms through which microorganism-host interactions occur and the possibility of microbiota editing in the prevention and treatment optimization of BC.
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Affiliation(s)
- Martina Di Modica
- Molecular Targeting Unit, Department of Research, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Nazionale dei Tumori, Milan, Italy
| | - Valeria Arlotta
- Molecular Targeting Unit, Department of Research, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Nazionale dei Tumori, Milan, Italy
| | - Lucia Sfondrini
- Molecular Targeting Unit, Department of Research, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Nazionale dei Tumori, Milan, Italy
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milan, Italy
| | - Elda Tagliabue
- Molecular Targeting Unit, Department of Research, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Nazionale dei Tumori, Milan, Italy
- *Correspondence: Elda Tagliabue,
| | - Tiziana Triulzi
- Molecular Targeting Unit, Department of Research, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Nazionale dei Tumori, Milan, Italy
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Kajiwara K, Osaki H, Greßies S, Kuwata K, Kim JH, Gensch T, Sato Y, Glorius F, Yamaguchi S, Taki M. A negative-solvatochromic fluorescent probe for visualizing intracellular distributions of fatty acid metabolites. Nat Commun 2022; 13:2533. [PMID: 35534485 PMCID: PMC9085894 DOI: 10.1038/s41467-022-30153-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 04/19/2022] [Indexed: 01/25/2023] Open
Abstract
Metabolic distribution of fatty acid to organelles is an essential biological process for energy homeostasis as well as for the maintenance of membrane integrity, and the metabolic pathways are strictly regulated in response to environmental stimuli. Herein, we report a fluorescent fatty acid probe, which bears an azapyrene dye that changes its absorption and emission features depending on the microenvironment polarity of the organelle into which it is transported. Owing to the environmental sensitivity of this dye, the distribution of the metabolically incorporated probe in non-polar lipid droplets, medium-polarity membranes, and the polar aqueous regions, can be visualized in different colors. Based on density scatter plots of the fluorophore, we demonstrate that the degradation of triacylglycerols in lipid droplets occurs predominantly via lipolysis rather than lipophagy in nutrition-starved hepatocytes. This tool can thus be expected to significantly advance our understanding of the lipid metabolism in living organisms. Metabolic distribution of fatty acids to organelles is an essential biological process for energy homeostasis. Here the authors report a fluorescent probe that allows multicolour visualisation of the intracellular distribution of exogenous fatty acids, metabolically incorporated as lipid components.
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9
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Huang Z, Luo R, Yang L, Chen H, Zhang X, Han J, Wang H, Zhou Z, Wang Z, Shao L. CPT1A-Mediated Fatty Acid Oxidation Promotes Precursor Osteoclast Fusion in Rheumatoid Arthritis. Front Immunol 2022; 13:838664. [PMID: 35273614 PMCID: PMC8902079 DOI: 10.3389/fimmu.2022.838664] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 02/01/2022] [Indexed: 12/29/2022] Open
Abstract
The overproduction of osteoclasts, leading to bone destruction in patients with rheumatoid arthritis (RA), is well established. However, little is known about the metabolic dysfunction of osteoclast precursors (OCPs) in RA. Herein, we show that increasing fatty acid oxidation (FAO) induces OCP fusion. Carnitine palmitoyltransferase IA (CPT1A), which is important for carnitine transportation and is involved in FAO in the mitochondria, is upregulated in RA patients. This metabolic change further increases the expression of clathrin heavy chain (CLTC) and clathrin light chain A (CLTA) by enhancing the binding of the transcription factor CCAAT/enhancer binding protein β (C/EBPβ) to the promoters of CLTA and CLTC. This drives clathrin-dependent endocytosis pathway, which attenuates fusion receptors in the cellular membrane and contributes to increased podosome structure formation. This study reveals a new mechanism through which FAO metabolism participates in joint destruction in RA and provides a novel therapeutic direction for the development of drugs against bone destruction in patients with RA.
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Affiliation(s)
- Zhaoyang Huang
- The Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Rong Luo
- The Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Liu Yang
- Department of Rheumatology, The Third Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Haiqi Chen
- The Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Xinyao Zhang
- Department of Urology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jiawen Han
- The Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Hongxia Wang
- Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhongyang Zhou
- The Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Zhao Wang
- Department of Orthopaedics, The Third Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Lan Shao
- The Center for Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
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10
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Lee H, Kwon Y, Jin H, Liu H, Kang W, Chun Y, Bae J, Choi H. Anticancer activity and metabolic profile alterations by ortho‐topolin riboside in in vitro and in vivo models of non‐small cell lung cancer. FASEB J 2022; 36:e22127. [DOI: 10.1096/fj.202101333r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/09/2021] [Accepted: 12/16/2021] [Indexed: 12/24/2022]
Affiliation(s)
- Hwanhui Lee
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Yeo‐Jung Kwon
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Hanyong Jin
- Key Laboratory of Natural Medicines of the Changbai Mountain Ministry of Education College of Pharmacy Yanbian University Yanji China
| | - Heifeng Liu
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Wonku Kang
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Young‐Jin Chun
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Jeehyeon Bae
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
| | - Hyung‐Kyoon Choi
- College of Pharmacy Chung‐Ang University Seoul Republic of Korea
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Hepatic synthesis of triacylglycerols containing medium-chain fatty acids is dominated by diacylglycerol acyltransferase 1 and efficiently inhibited by etomoxir. Mol Metab 2020; 45:101150. [PMID: 33359403 PMCID: PMC7843514 DOI: 10.1016/j.molmet.2020.101150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/07/2020] [Accepted: 12/16/2020] [Indexed: 11/30/2022] Open
Abstract
Objective Medium-chain fatty acids (MCFAs) play an increasing role in human nutrition. In the liver, one fraction is used for synthesis of MCFA-containing triacylglycerol (MCFA-TG), and the rest is used for oxidative energy production or ketogenesis. We investigated which enzymes catalyse the synthesis of MCFA-TG and how inhibition of MCFA-TG synthesis or fatty acid (FA) oxidation influences the metabolic fate of the MCFAs. Methods FA metabolism was followed by time-resolved tracing of alkyne-labelled FAs in freshly isolated mouse hepatocytes. Quantitative data were obtained by mass spectrometry of several hundred labelled lipid species. Wild-type hepatocytes and cells from diacylglycerol acyltransferase (DGAT)1−/− mice were treated with inhibitors against DGAT1, DGAT2, or FA β-oxidation. Results Inhibition or deletion of DGAT1 resulted in a reduction of MCFA-TG synthesis by 70%, while long-chain (LC)FA-TG synthesis was reduced by 20%. In contrast, DGAT2 inhibition increased MCFA-TG formation by 50%, while LCFA-TG synthesis was reduced by 5–25%. Inhibition of β-oxidation by the specific inhibitor teglicar strongly increased MCFA-TG synthesis. In contrast, the widely used β-oxidation inhibitor etomoxir blocked MCFA-TG synthesis, phenocopying DGAT1 inhibition. Conclusions DGAT1 is the major enzyme for hepatic MCFA-TG synthesis. Its loss can only partially be compensated by DGAT2. Specific inhibition of β-oxidation leads to a compensatory increase in MCFA-TG synthesis, whereas etomoxir blocks both β-oxidation and MCFA-TG synthesis, indicating a strong off-target effect on DGAT1.
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12
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Ghoneum A, Abdulfattah AY, Warren BO, Shu J, Said N. Redox Homeostasis and Metabolism in Cancer: A Complex Mechanism and Potential Targeted Therapeutics. Int J Mol Sci 2020; 21:E3100. [PMID: 32354000 PMCID: PMC7247161 DOI: 10.3390/ijms21093100] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/22/2020] [Accepted: 04/26/2020] [Indexed: 12/13/2022] Open
Abstract
Reactive Oxygen Species or "ROS" encompass several molecules derived from oxygen that can oxidize other molecules and subsequently transition rapidly between species. The key roles of ROS in biological processes are cell signaling, biosynthetic processes, and host defense. In cancer cells, increased ROS production and oxidative stress are instigated by carcinogens, oncogenic mutations, and importantly, metabolic reprograming of the rapidly proliferating cancer cells. Increased ROS production activates myriad downstream survival pathways that further cancer progression and metastasis. In this review, we highlight the relation between ROS, the metabolic programing of cancer, and stromal and immune cells with emphasis on and the transcription machinery involved in redox homeostasis, metabolic programing and malignant phenotype. We also shed light on the therapeutic targeting of metabolic pathways generating ROS as we investigate: Orlistat, Biguandes, AICAR, 2 Deoxyglucose, CPI-613, and Etomoxir.
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Affiliation(s)
- Alia Ghoneum
- Departments of Cancer Biology, Wake Forest University School of Medicine, Winston Salem, NC 27157, USA
| | - Ammar Yasser Abdulfattah
- Departments of Cancer Biology, Wake Forest University School of Medicine, Winston Salem, NC 27157, USA
| | - Bailey Olivia Warren
- Departments of Cancer Biology, Wake Forest University School of Medicine, Winston Salem, NC 27157, USA
| | - Junjun Shu
- Departments of Cancer Biology, Wake Forest University School of Medicine, Winston Salem, NC 27157, USA
- The Third Affiliated Hospital of Nanchang University, Nanchang 330006, China
| | - Neveen Said
- Departments of Cancer Biology, Wake Forest University School of Medicine, Winston Salem, NC 27157, USA
- Departments of Urology, Wake Forest University School of Medicine, Winston Salem, NC 27157, USA
- Comprehensive Cancer Center, Winston Salem, NC 27157, USA
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13
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D'Souza L, Bhattacharya D. Plasma cells: You are what you eat. Immunol Rev 2019; 288:161-177. [PMID: 30874356 DOI: 10.1111/imr.12732] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/03/2018] [Indexed: 12/26/2022]
Abstract
Plasma cells are terminally differentiated B lymphocytes that constitutively secrete antibodies. These antibodies can provide protection against pathogens, and their quantity and quality are the best clinical correlates of vaccine efficacy. As such, plasma cell lifespan is the primary determinant of the duration of humoral immunity. Yet dysregulation of plasma cell function can cause autoimmunity or multiple myeloma. The longevity of plasma cells is primarily dictated by nutrient uptake and non-transcriptionally regulated metabolic pathways. We have previously shown a positive effect of glucose uptake and catabolism on plasma cell longevity and function. In this review, we discuss these findings with an emphasis on nutrient uptake and its effects on respiratory capacity, lifespan, endoplasmic reticulum stress, and antibody secretion in plasma cells. We further discuss how some of these pathways may be dysregulated in multiple myeloma, potentially providing new therapeutic targets. Finally, we speculate on the connection between plasma cell intrinsic metabolism and systemic changes in nutrient availability and metabolic diseases.
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Affiliation(s)
- Lucas D'Souza
- Department of Immunobiology, University of Arizona College of Medicine, Tucson, Arizona
| | - Deepta Bhattacharya
- Department of Immunobiology, University of Arizona College of Medicine, Tucson, Arizona
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14
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Polyzos AA, Lee DY, Datta R, Hauser M, Budworth H, Holt A, Mihalik S, Goldschmidt P, Frankel K, Trego K, Bennett MJ, Vockley J, Xu K, Gratton E, McMurray CT. Metabolic Reprogramming in Astrocytes Distinguishes Region-Specific Neuronal Susceptibility in Huntington Mice. Cell Metab 2019; 29:1258-1273.e11. [PMID: 30930170 PMCID: PMC6583797 DOI: 10.1016/j.cmet.2019.03.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 10/25/2018] [Accepted: 03/05/2019] [Indexed: 12/23/2022]
Abstract
The basis for region-specific neuronal toxicity in Huntington disease is unknown. Here, we show that region-specific neuronal vulnerability is a substrate-driven response in astrocytes. Glucose is low in HdhQ(150/150) animals, and astrocytes in each brain region adapt by metabolically reprogramming their mitochondria to use endogenous, non-glycolytic metabolites as an alternative fuel. Each region is characterized by distinct metabolic pools, and astrocytes adapt accordingly. The vulnerable striatum is enriched in fatty acids, and mitochondria reprogram by oxidizing them as an energy source but at the cost of escalating reactive oxygen species (ROS)-induced damage. The cerebellum is replete with amino acids, which are precursors for glucose regeneration through the pentose phosphate shunt or gluconeogenesis pathways. ROS is not elevated, and this region sustains little damage. While mhtt expression imposes disease stress throughout the brain, sensitivity or resistance arises from an adaptive stress response, which is inherently region specific. Metabolic reprogramming may have relevance to other diseases.
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Affiliation(s)
- Aris A Polyzos
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Do Yup Lee
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Rupsa Datta
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
| | - Meghan Hauser
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Helen Budworth
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Amy Holt
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Stephanie Mihalik
- Department of Pediatrics at Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Pike Goldschmidt
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Ken Frankel
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kelly Trego
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Michael J Bennett
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jerry Vockley
- Department of Pediatrics at Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Ke Xu
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
| | - Cynthia T McMurray
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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15
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Schistosoma mansoni does not and cannot oxidise fatty acids, but these are used for biosynthetic purposes instead. Int J Parasitol 2019; 49:647-656. [PMID: 31170410 DOI: 10.1016/j.ijpara.2019.03.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 03/15/2019] [Accepted: 03/24/2019] [Indexed: 12/14/2022]
Abstract
Adult schistosomes, parasitic flatworms that cause the tropical disease schistosomiasis, have always been considered to be homolactic fermenters and, in their energy metabolism, strictly dependent on carbohydrates. However, more recent studies suggested that fatty acid β-oxidation is essential for egg production by adult female Schistosoma mansoni. To address this conundrum, we performed a comprehensive study on the lipid metabolism of S. mansoni. Incubations with [14C]-labelled fatty acids demonstrated that adults, eggs and miracidia of S. mansoni did not oxidise fatty acids, as no 14CO2 production could be detected. We then re-examined the S. mansoni genome using the genes known to be involved in fatty acid oxidation in six eukaryotic model reference species. This showed that the earlier automatically annotated genes for fatty acid oxidation were in fact incorrectly annotated. In a further analysis we could not detect any genes encoding β-oxidation enzymes, which demonstrates that S. mansoni cannot use this pathway in any of its lifecycle stages. The same was true for Schistosoma japonicum and all other schistosome species that have been sequenced. Absence of β-oxidation, however, does not imply that fatty acids from the host are not metabolised by schistosomes. Adult schistosomes can use and modify fatty acids from their host for biosynthetic purposes and incorporate those in phospholipids and neutral lipids. Female worms deposit large amounts of these lipids in the eggs they produce, which explains why interference with the lipid metabolism in females will disturb egg formation, even though fatty acid β-oxidation does not occur in schistosomes. Our analyses of S. mansoni further revealed that during the development and maturation of the miracidium inside the egg, changes in lipid composition occur which indicate that fatty acids deposited in the egg by the female worm are used for phospholipid biosynthesis required for membrane formation in the developing miracidium.
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16
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Bettonville M, d'Aria S, Weatherly K, Porporato PE, Zhang J, Bousbata S, Sonveaux P, Braun MY. Long-term antigen exposure irreversibly modifies metabolic requirements for T cell function. eLife 2018; 7:30938. [PMID: 29911570 PMCID: PMC6025959 DOI: 10.7554/elife.30938] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 06/14/2018] [Indexed: 12/11/2022] Open
Abstract
Energy metabolism is essential for T cell function. However, how persistent antigenic stimulation affects T cell metabolism is unknown. Here, we report that long-term in vivo antigenic exposure induced a specific deficit in numerous metabolic enzymes. Accordingly, T cells exhibited low basal glycolytic flux and limited respiratory capacity. Strikingly, blockade of inhibitory receptor PD-1 stimulated the production of IFNγ in chronic T cells, but failed to shift their metabolism towards aerobic glycolysis, as observed in effector T cells. Instead, chronic T cells appeared to rely on oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO) to produce ATP for IFNγ synthesis. Check-point blockade, however, increased mitochondrial production of superoxide and reduced viability and effector function. Thus, in the absence of a glycolytic switch, PD-1-mediated inhibition appears essential for limiting oxidative metabolism linked to effector function in chronic T cells, thereby promoting survival and functional fitness.
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Affiliation(s)
- Marie Bettonville
- Institute for Medical Immunology, Université Libre de Bruxelles, Gosselies, Belgium
| | - Stefania d'Aria
- Institute for Medical Immunology, Université Libre de Bruxelles, Gosselies, Belgium
| | - Kathleen Weatherly
- Institute for Medical Immunology, Université Libre de Bruxelles, Gosselies, Belgium
| | - Paolo E Porporato
- Pole of Pharmacology & Therapeutics, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Jinyu Zhang
- Institute for Medical Immunology, Université Libre de Bruxelles, Gosselies, Belgium
| | - Sabrina Bousbata
- Laboratory of Molecular Parasitology, Proteomic Platform, Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, Gosselies, Belgium
| | - Pierre Sonveaux
- Pole of Pharmacology & Therapeutics, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Michel Y Braun
- Institute for Medical Immunology, Université Libre de Bruxelles, Gosselies, Belgium
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17
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Kumar V. T cells and their immunometabolism: A novel way to understanding sepsis immunopathogenesis and future therapeutics. Eur J Cell Biol 2018; 97:379-392. [PMID: 29773345 DOI: 10.1016/j.ejcb.2018.05.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/03/2018] [Accepted: 05/03/2018] [Indexed: 02/08/2023] Open
Abstract
Sepsis has always been considered as a big challenge for pharmaceutical companies in terms of discovering and designing new therapeutics. The pathogenesis of sepsis involves aberrant activation of innate immune cells (i.e. macrophages, neutrophils etc.) at early stages. However, a stage of immunosuppression is also observed during sepsis even in the patients who have recovered from it. This stage of immunosuppression is observed due to the loss of conventional (i.e. CD4+, CD8+) T cells, Th17 cells and an upregulation of regulatory T cells (Tregs). This process also impacts metabolic processes controlling immune cell metabolism called immunometabolism. The present review is focused on the T cell-mediated immune response, their immunometabolism and targeting T cell immunometabolism during sepsis as future therapeutic approach. The first part of the manuscripts describes an impact of sepsis on conventional T cells, Th17 cells and Tregs along with their impact on sepsis. The subsequent section further describes the immunometabolism of these cells (CD4+, CD8+, Th17, and Tregs) under normal conditions and during sepsis-induced immunosuppression. The article ends with the therapeutic targeting of T cell immunometabolism (both conventional T cells and Tregs) during sepsis as a future immunomodulatory approach for its management.
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Affiliation(s)
- V Kumar
- Children's Health Queensland Clinical Unit, School of Clinical Medicine, Mater Research, Faculty of Medicine, University of Queensland, St. Lucia, Brisbane, Queensland 4078, Australia; School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, Brisbane, Queensland 4078, Australia.
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18
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O'Connor RS, Guo L, Ghassemi S, Snyder NW, Worth AJ, Weng L, Kam Y, Philipson B, Trefely S, Nunez-Cruz S, Blair IA, June CH, Milone MC. The CPT1a inhibitor, etomoxir induces severe oxidative stress at commonly used concentrations. Sci Rep 2018; 8:6289. [PMID: 29674640 PMCID: PMC5908836 DOI: 10.1038/s41598-018-24676-6] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 04/03/2018] [Indexed: 11/09/2022] Open
Abstract
Etomoxir (ETO) is a widely used small-molecule inhibitor of fatty acid oxidation (FAO) through its irreversible inhibitory effects on the carnitine palmitoyl-transferase 1a (CPT1a). We used this compound to evaluate the role of fatty acid oxidation in rapidly proliferating T cells following costimulation through the CD28 receptor. We show that ETO has a moderate effect on T cell proliferation with no observable effect on memory differentiation, but a marked effect on oxidative metabolism. We show that this oxidative metabolism is primarily dependent upon glutamine rather than FAO. Using an shRNA approach to reduce CPT1a in T cells, we further demonstrate that the inhibition of oxidative metabolism in T cells by ETO is independent of its effects on FAO at concentrations exceeding 5 μM. Concentrations of ETO above 5 μM induce acute production of ROS with associated evidence of severe oxidative stress in proliferating T cells. In aggregate, these data indicate that ETO lacks specificity for CTP1a above 5 μM, and caution should be used when employing this compound for studies in cells due to its non-specific effects on oxidative metabolism and cellular redox.
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Affiliation(s)
- Roddy S O'Connor
- Center for Cellular Immunotherapies, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Lili Guo
- Penn SRP center, Center of Excellence in Environmental Toxicology, and Department of Systems Pharmacology and Translational Therapeutics at the University of Pennsylvania, Philadelphia, PA, USA
| | - Saba Ghassemi
- Center for Cellular Immunotherapies, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | | | - Andrew J Worth
- Penn SRP center, Center of Excellence in Environmental Toxicology, and Department of Systems Pharmacology and Translational Therapeutics at the University of Pennsylvania, Philadelphia, PA, USA
| | - Liwei Weng
- Penn SRP center, Center of Excellence in Environmental Toxicology, and Department of Systems Pharmacology and Translational Therapeutics at the University of Pennsylvania, Philadelphia, PA, USA
| | | | | | - Sophie Trefely
- A.J. Drexel Autism Institute, Drexel University, Philadelphia, PA, USA
| | - Selene Nunez-Cruz
- Center for Cellular Immunotherapies, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Ian A Blair
- Penn SRP center, Center of Excellence in Environmental Toxicology, and Department of Systems Pharmacology and Translational Therapeutics at the University of Pennsylvania, Philadelphia, PA, USA
| | - Carl H June
- Center for Cellular Immunotherapies, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Michael C Milone
- Center for Cellular Immunotherapies, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
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19
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Binger KJ, Côrte-Real BF, Kleinewietfeld M. Immunometabolic Regulation of Interleukin-17-Producing T Helper Cells: Uncoupling New Targets for Autoimmunity. Front Immunol 2017; 8:311. [PMID: 28377767 PMCID: PMC5359241 DOI: 10.3389/fimmu.2017.00311] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/06/2017] [Indexed: 01/04/2023] Open
Abstract
Interleukin-17-producing T helper (Th17) cells are critical for the host defense of bacterial and fungal pathogens and also play a major role in driving pathogenic autoimmune responses. Recent studies have indicated that the generation of Th17 cells from naïve CD4+ T cells is coupled with massive cellular metabolic adaptations, necessary to cope with different energy and metabolite requirements associated with switching from a resting to proliferative state. Furthermore, Th17 cells have to secure these metabolic adaptations when facing nutrient-limiting environments, such as at the sites of inflammation. Accumulating data indicates that this metabolic reprogramming is significantly linked to the differentiation of T helper cells and, particularly, that the metabolic changes of Th17 cells and anti-inflammatory Forkhead box P3+ regulatory T cells are tightly and reciprocally regulated. Thus, a better understanding of these processes could offer potential new targets for therapeutic interventions for autoimmune diseases. In this mini-review, we will highlight some of the recent advances and discoveries in the field, with a particular focus on metabolic demands of Th17 cells and their implications for autoimmunity.
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Affiliation(s)
- Katrina J Binger
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne , Parkville, VIC , Australia
| | - Beatriz F Côrte-Real
- VIB Laboratory of Translational Immunomodulation, Hasselt University, BIOMED , Diepenbeek , Belgium
| | - Markus Kleinewietfeld
- VIB Laboratory of Translational Immunomodulation, Hasselt University, BIOMED , Diepenbeek , Belgium
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20
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Chen Y, Carlessi R, Walz N, Cruzat VF, Keane K, John AN, Jiang FX, Carnagarin R, Dass CR, Newsholme P. Pigment epithelium-derived factor (PEDF) regulates metabolism and insulin secretion from a clonal rat pancreatic beta cell line BRIN-BD11 and mouse islets. Mol Cell Endocrinol 2016; 426:50-60. [PMID: 26868448 DOI: 10.1016/j.mce.2016.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 01/23/2016] [Accepted: 02/05/2016] [Indexed: 02/05/2023]
Abstract
Pigment epithelium-derived factor (PEDF) is a multifunctional glycoprotein, associated with lipid catabolism and insulin resistance. In the present study, PEDF increased chronic and acute insulin secretion in a clonal rat β-cell line BRIN-BD11, without alteration of glucose consumption. PEDF also stimulated insulin secretion from primary mouse islets. Seahorse flux analysis demonstrated that PEDF did not change mitochondrial respiration and glycolytic function. The cytosolic presence of the putative PEDF receptor - adipose triglyceride lipase (ATGL) - was identified, and ATGL associated stimulation of glycerol release was robustly enhanced by PEDF, while intracellular ATP levels increased. Addition of palmitate or ex vivo stimulation with inflammatory mediators induced β-cell dysfunction, effects not altered by the addition of PEDF. In conclusion, PEDF increased insulin secretion in BRIN-BD11 and islet cells, but had no impact on glucose metabolism. Thus elevated lipolysis and enhanced fatty acid availability may impact insulin secretion following PEDF receptor (ATGL) stimulation.
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Affiliation(s)
- Younan Chen
- School of Biomedical Sciences, CHIRI Biosciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia; Key Laboratory of Transplant Engineering and Immunology, NHFPC; Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, PR China.
| | - Rodrigo Carlessi
- School of Biomedical Sciences, CHIRI Biosciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Nikita Walz
- School of Biomedical Sciences, CHIRI Biosciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Vinicius Fernandes Cruzat
- School of Biomedical Sciences, CHIRI Biosciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Kevin Keane
- School of Biomedical Sciences, CHIRI Biosciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Abraham N John
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Fang-Xu Jiang
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Revathy Carnagarin
- School of Pharmacy, CHIRI Biosciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Crispin R Dass
- School of Pharmacy, CHIRI Biosciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia
| | - Philip Newsholme
- School of Biomedical Sciences, CHIRI Biosciences, Curtin University, GPO Box U1987, Perth, Western Australia, Australia.
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21
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Targeting prostate cancer cell metabolism: impact of hexokinase and CPT-1 enzymes. Tumour Biol 2014; 36:2893-905. [PMID: 25501281 DOI: 10.1007/s13277-014-2919-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 11/28/2014] [Indexed: 10/24/2022] Open
Abstract
Glycolysis has been shown to be required for the cell growth and proliferation in several cancer cells. However, prostate cancer cells were accused of using more fatty acid than glucose to meet their bioenergetic demands. The present study was designed to evaluate the involvement of hexokinase and CPT-1 in the cell growth and proliferation of human prostate cancer cell lines, PC3, and LNCaP-FGC-10. Hexokinase and CPT-1 activities were examined in the presence of different concentrations of their inhibitors, lonidamine and etomoxir, to find the concentration of maximum inhibition ([I max]). To assess cell viability and proliferation, dimethylthiazol (MTT) assay was carried out using [I max] for 24, 48, and 72 h on PC3 and LNCaP cells. Apoptosis was determined using annexin-V, caspase-3 activity assay, Hoechst 33258 staining, and evaluation of mitochondrial membrane potential (MMP). Moreover, ATP levels were measured following lonidamine and etomoxir exposure. In addition, to define the impact of exogenous fatty acid on the cell growth and proliferation, CPT-1 activity was evaluated in the presence of palmitate (50 μM). Hexokinase and CPT-1 activities were significantly inhibited by lonidamine [600 μM] and etomoxir [100 μM] in both cell lines. Treatment of the cells with lonidamine [600 μM] resulted in a significant ATP reduction, cell viability and apoptosis, caspase-3 activity elevation, MMP reduction, and appearance of apoptosis-related morphological changes in the cells. In contrast, etomoxir [100 μM] just decreased ATP levels in both cell lines without significant cell death and apoptosis. Compared with glucose (2 g/L), palmitate intensified CPT-1 activity in both cell lines, especially in LNCaP cells. In addition, activity of CPT-1 was higher in LNCaP than PC3 cells. Our results suggest that prostate cancer cells may metabolize glucose as a source of bioenergetic pathways. ATP could also be produced by long-chain fatty acid oxidation. In addition, these data might suggest that LNCaP is more compatible with palmitate.
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22
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Tyurina YY, Winnica DE, Kapralova VI, Kapralov AA, Tyurin VA, Kagan VE. LC/MS characterization of rotenone induced cardiolipin oxidation in human lymphocytes: implications for mitochondrial dysfunction associated with Parkinson's disease. Mol Nutr Food Res 2013; 57:1410-22. [PMID: 23650208 PMCID: PMC3810210 DOI: 10.1002/mnfr.201200801] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 02/26/2013] [Accepted: 02/27/2013] [Indexed: 02/06/2023]
Abstract
SCOPE Rotenone is a toxicant believed to contribute to the development of Parkinson's disease. METHODS AND RESULTS Using human peripheral blood lymphocytes we demonstrated that exposure to rotenone resulted in disruption of electron transport accompanied by the production of reactive oxygen species, development of apoptosis and elevation of peroxidase activity of mitochondria. Employing LC/MS-based lipidomics/oxidative lipidomics we characterized molecular species of cardiolipin (CL) and its oxidation/hydrolysis products formed early in apoptosis and associated with the rotenone-induced mitochondrial dysfunction. CONCLUSION The major oxidized CL species - tetra-linoleoyl-CL - underwent oxidation to yield epoxy-C18:2 and dihydroxy-C18:2 derivatives predominantly localized in sn-1 and sn-2 positions, respectively. In addition, accumulation of mono-lyso-CL species and oxygenated free C18:2 were detected in rotenone-treated lymphocytes. These oxidation/hydrolysis products may be useful for the development of new biomarkers of mitochondrial dysfunction.
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Affiliation(s)
- Yulia Y. Tyurina
- Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, Graduate School of Public Health; University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Daniel E. Winnica
- Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, Graduate School of Public Health; University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Valentina I. Kapralova
- Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, Graduate School of Public Health; University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Alexandr A. Kapralov
- Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, Graduate School of Public Health; University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Vladimir A. Tyurin
- Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, Graduate School of Public Health; University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Valerian E. Kagan
- Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, Graduate School of Public Health; University of Pittsburgh, Pittsburgh, PA 15219, USA
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23
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Singh V, Jamwal S, Jain R, Verma P, Gokhale R, Rao KVS. Mycobacterium tuberculosis-driven targeted recalibration of macrophage lipid homeostasis promotes the foamy phenotype. Cell Host Microbe 2012; 12:669-81. [PMID: 23159056 DOI: 10.1016/j.chom.2012.09.012] [Citation(s) in RCA: 203] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 06/27/2012] [Accepted: 09/17/2012] [Indexed: 11/28/2022]
Abstract
Upon infection, Mycobacterium tuberculosis (Mtb) metabolically alters the macrophage to create a niche that is ideally suited to its persistent lifestyle. Infected macrophages acquire a "foamy" phenotype characterized by the accumulation of lipid bodies (LBs), which serve as both a source of nutrients and a secure niche for the bacterium. While the functional significance of the foamy phenotype is appreciated, the biochemical pathways mediating this process are understudied. We found that Mtb induces the foamy phenotype via targeted manipulation of host cellular metabolism to divert the glycolytic pathway toward ketone body synthesis. This dysregulation enabled feedback activation of the anti-lipolytic G protein-coupled receptor GPR109A, leading to perturbations in lipid homeostasis and consequent accumulation of LBs in the macrophage. ESAT-6, a secreted Mtb virulence factor, mediates the enforcement of this feedback loop. Finally, we demonstrate that pharmacological targeting of pathways mediating this host-pathogen metabolic crosstalk provides a potential strategy for developing tuberculosis chemotherapy.
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Affiliation(s)
- Varshneya Singh
- Immunology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
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24
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Sánchez-Gurmaches J, Cruz-Garcia L, Gutiérrez J, Navarro I. Endocrine control of oleic acid and glucose metabolism in rainbow trout (Oncorhynchus mykiss) muscle cells in culture. Am J Physiol Regul Integr Comp Physiol 2010; 299:R562-72. [PMID: 20484701 DOI: 10.1152/ajpregu.00696.2009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of insulin and IGF-I on fatty acid (FA) and glucose metabolism were examined using oleic acid or glucose as tracers in differentiated rainbow trout (Oncorhynchus mykiss) myotubes. Insulin and IGF-I significantly reduced the production of CO(2) from oleic acid with respect to the control values. IGF-I also significantly reduced the production of acid-soluble products (ASP) and the concentration of FA in the medium, while cellular triacylglycerols (TAG) tended to increase. Only insulin produced a significant accumulation of glycogen inside the cells in glucose distribution experiments. Incubation with catecholamines did not affect oleic acid metabolism. Cells treated with rapamycin [a target of rapamycin (TOR) inhibitor] significantly increased the oxidation of oleic acid to CO(2) and ASP, while the accumulation of TAG diminished. Rosiglitazone (a peroxisome proliferator-activated receptor gamma agonist) and etomoxir (a CPT-1 inhibitor) produced a severe and significant reduction in the production of CO(2) and ASP. Rosiglitazone and etomoxir also produced a significant accumulation of FA outside and inside the cells, respectively. No significant effects of these drugs on glucose distribution were observed. These data indicate that insulin and IGF-I act as anabolic hormones in trout myotubes in both oleic acid and glucose metabolism, although glucose oxidation appears to be less sensitive than FA oxidation to insulin and IGF-I. The use of rapamycin, etomoxir, and rosiglitazone may help us to understand the mechanisms of regulation of lipid metabolism in fish.
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Mechanism of the elevation in cardiolipin during HeLa cell entry into the S-phase of the human cell cycle. Biochem J 2008; 417:573-82. [DOI: 10.1042/bj20080650] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
CL (cardiolipin) is a key phospholipid involved in ATP generation. Since progression through the cell cycle requires ATP we examined regulation of CL synthesis during S-phase in human cells and investigated whether CL or CL synthesis was required to support nucleotide synthesis in S-phase. HeLa cells were made quiescent by serum depletion for 24 h. Serum addition resulted in substantial stimulation of [methyl-3H]thymidine incorporation into cells compared with serum-starved cells by 8 h, confirming entry into the S-phase. CL mass was unaltered at 8 h, but increased 2-fold by 16 h post-serum addition compared with serum-starved cells. The reason for the increase in CL mass upon entry into S-phase was an increase in activity and expression of CL de novo biosynthetic and remodelling enzymes and this paralleled the increase in mitochondrial mass. CL de novo biosynthesis from D-[U-14C]glucose was elevated, and from [1,3-3H]glycerol reduced, upon serum addition to quiescent cells compared with controls and this was a result of differences in the selection of precursor pools at the level of uptake. Triascin C treatment inhibited CL synthesis from [1-14C]oleate but did not affect [methyl-3H]thymidine incorporation into HeLa cells upon serum addition to serum-starved cells. Barth Syndrome lymphoblasts, which exhibit reduced CL, showed similar [methyl-3H]thymidine incorporation into cells upon serum addition to serum-starved cells compared with cells from normal aged-matched controls. The results indicate that CL de novo biosynthesis is up-regulated via elevated activity and expression of CL biosynthetic genes and this accounted for the doubling of CL seen during S-phase; however, normal de novo CL biosynthesis or CL itself is not essential to support nucleotide synthesis during entry into S-phase of the human cell cycle.
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Sethi V, Rubinstein I, Dudeja P, Weinberg G, Onyuksel H. Biphasic behavior of bupivacaine and cardiolipin-containing biomimetic membrane interaction. J Drug Deliv Sci Technol 2008. [DOI: 10.1016/s1773-2247(08)50009-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Bays HE, Cohen DE. Rationale and design of a prospective clinical trial program to evaluate the glucose-lowering effects of colesevelam HCl in patients with type 2 diabetes mellitus. Curr Med Res Opin 2007; 23:1673-84. [PMID: 17588297 DOI: 10.1185/030079907x210525] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Dyslipidemia and type 2 diabetes mellitus (T2DM) increase atherosclerotic coronary heart disease (CHD) risk. In patients with T2DM, improving lipid parameters reduces CHD risk, while optimizing glucose levels reduces microvascular complications and, possibly, macrovascular disease such as CHD. Unfortunately, many patients with T2DM do not achieve either lipid or glucose treatment targets. OBJECTIVE Colesevelam HCl is a specifically engineered bile-acid sequestrant (BAS) indicated to reduce elevated low-density lipoprotein cholesterol concentrations. Earlier studies have demonstrated that BAS not only reduce cholesterol levels, but also lower glucose levels in patients with T2DM. These findings have prompted a robust, prospective phase 3 clinical trial program to further evaluate the safety and tolerability of colesevelam HCl when added to T2DM patients previously treated with metformin, insulin or a sulfonylurea. A limitation of these clinical trials is that none of them assessed colesevelam HCl monotherapy, nor directly compared the glucose-lowering effects of colesevelam HCl to established oral antidiabetes drugs. Nonetheless, this clinical trial program will better determine whether a single agent added to existing diabetes therapy can improve both lipid and glucose parameters in T2DM, which may allow more patients to achieve lipid and glucose treatment targets. CONCLUSIONS This phase 3 clinical trial program will evaluate colesevelam's glucose-lowering effects in patients with T2DM. In addition, based upon a review of the relevant medical literature through an online electronic PubMed search (without restriction to date other than otherwise occurs through PubMed), potential mechanisms as to how BAS may lower glucose levels are discussed.
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Affiliation(s)
- Harold E Bays
- Louisville Metabolic and Atherosclerosis Research Center Inc., Louisville, KY 40213,USA.
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28
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Martinez Agosto JA, McCabe ER. Conserved family of glycerol kinase loci in Drosophila melanogaster. Mol Genet Metab 2006; 88:334-45. [PMID: 16545593 PMCID: PMC2807631 DOI: 10.1016/j.ymgme.2006.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2006] [Accepted: 01/10/2006] [Indexed: 10/24/2022]
Abstract
Glycerol kinase (GK) is an enzyme that catalyzes the formation of glycerol 3-phosphate from ATP and glycerol, the rate-limiting step in glycerol utilization. We analyzed the genome of the model organism Drosophila melanogaster and identified five GK orthologs, including two loci with sequence homology to the mammalian Xp21 GK protein. Using a combination of sequence analysis and evolutionary comparisons of orthologs between species, we characterized functional domains in the protein required for GK activity. Our findings include additional conserved domains that suggest novel nuclear and mitochondrial functions for glycerol kinase in apoptosis and transcriptional regulation. Investigation of GK function in Drosophila will inform us about the role of this enzyme in development and will provide us with a tool to examine genetic modifiers of human metabolic disorders.
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Affiliation(s)
- Julian A. Martinez Agosto
- Department of Pediatrics, David Geffen School of Medicine at UCLA; and Mattel Children’s Hospital at UCLA, USA
| | - Edward R.B. McCabe
- Department of Pediatrics, David Geffen School of Medicine at UCLA; and Mattel Children’s Hospital at UCLA, USA
- Department of Human Genetics, David Geffen School of Medicine at UCLA; UCLA Molecular Biology Institute; and UCLA Biomedical Engineering Interdepartmental Training Program, USA
- Corresponding author. Fax: +1 310 267 2045. (E.R.B. McCabe)
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29
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Lu YJ, Zhang YM, Rock CO. Product diversity and regulation of type II fatty acid synthases. Biochem Cell Biol 2004; 82:145-55. [PMID: 15052334 DOI: 10.1139/o03-076] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Fatty acid biosynthesis is catalyzed in most bacteria by a group of highly conserved proteins known as the type II fatty acid synthase (FAS II) system. FAS II has been extensively studied in the Escherichia coli model system, and the recent explosion of bioinformatic information has accelerated the investigation of the pathway in other organisms, mostly important human pathogens. All FAS II systems possess a basic set of enzymes for the initiation and elongation of acyl chains. This review focuses on the variations on this basic theme that give rise to the diversity of products produced by the pathway. These include multiple mechanisms to generate unsaturated fatty acids and the accessory components required for branched-chain fatty acid synthesis in Gram-positive bacteria. Most of the known mechanisms that regulate product distribution of the pathway arise from the fundamental biochemical properties of the expressed enzymes. However, newly identified transcriptional factors in bacterial fatty acid biosynthetic pathways are a fertile field for new investigation into the genetic control of the FAS II system. Much more work is needed to define the role of these factors and the mechanisms that regulate their DNA binding capability, but there appear to be fundamental differences in how the expression of the pathway genes is controlled in Gram-negative and in Gram-positive bacteria.Key words: fatty acid synthase, bacteria.
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Affiliation(s)
- Ying-Jie Lu
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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Abstract
Phospholipids are important structural and functional components of all biological membranes and define the compartmentation of organelles. Mitochondrial phospholipids comprise a significant proportion of the entire phospholipid content of most eukaroytic cells. In the heart, a tissue rich in mitochondria, the mitochondrial phospholipids provide for diverse roles in the regulation of various mitochondrial processes including apoptosis, electron transport, and mitochondrial lipid and protein import. It is well documented that alteration in the content and fatty acid composition of phospholipids within the heart is linked to alterations in myocardial electrical activity. In addition, reduction in the specific mitochondrial phospholipid cardiolipin is an underlying biochemical cause of Barth Syndrome, a rare and often fatal X-linked genetic disease that is associated with cardiomyopathy. Thus, maintenance of both the content and molecular composition of phospholipids synthesized within the mitochondria is essential for normal cardiac function. This review will focus on the function and regulation of the biosynthesis and resynthesis of mitochondrial phospholipids in the mammalian heart.Key words: phospholipid, metabolism, heart, cardiolipin, mitochondria.
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Affiliation(s)
- Grant M Hatch
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Canada.
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31
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Jiang YJ, Lu B, Xu FY, Gartshore J, Taylor WA, Halayko AJ, Gonzalez FJ, Takasaki J, Choy PC, Hatch GM. Stimulation of cardiac cardiolipin biosynthesis by PPARα activation. J Lipid Res 2004; 45:244-52. [PMID: 14594999 DOI: 10.1194/jlr.m300314-jlr200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The role of peroxisome proliferator-activated receptor alpha (PPARalpha)-stimulated phospholipase A2 (PLA2) in cardiac mitochondrial cardiolipin (CL) biosynthesis was examined in both in vivo and in vitro models. Treatment of rat heart H9c2 cells with clofibrate increased the expression and activity of 14 kDa PLA2 but did not affect the pool size of CL. Clofibrate treatment stimulated de novo CL biosynthesis via an increase in phosphatidylglycerolphosphate (PGP) synthase activity, accounting for the unaltered CL content. Cardiac PLA2, PGP synthase, and CDP-1,2-diacyl-sn-glycerol synthase (CDS-2) activities and CDS-2 mRNA levels were elevated in mice fed clofibrate for 14 days compared with controls. In PPARalpha-null mice, clofibrate feeding did not alter cardiac PLA2, PGP synthase activities, or CDS-2 activity and mRNA level, confirming that these enzymes are regulated by PPARalpha activation. In contrast to mouse heart, clofibrate treatment did not affect the activity or mRNA levels of CDS-2 in H9c2 cells, indicating that CDS-2 is regulated differently in rat heart H9c2 cells in vitro and in mouse heart in vivo. These results clearly indicate that cardiac CL de novo biosynthesis is stimulated by PPARalpha activation in responsive rodent models and that CDS-2 is an example of an enzyme that exhibits alternative regulation in vivo and in cultured cell lines. This study is the first to demonstrate that CL de novo biosynthesis is regulated by PPARalpha activation.
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Affiliation(s)
- Yan J Jiang
- Center for Research and Treatment of Atherosclerosis and Department of Biochemistry and Medical Genetics, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
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Washington L, Cook GA, Mansbach CM. Inhibition of carnitine palmitoyltransferase in the rat small intestine reduces export of triacylglycerol into the lymph. J Lipid Res 2003; 44:1395-403. [PMID: 12700347 DOI: 10.1194/jlr.m300123-jlr200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Following digestion of dietary triacylglycerol (TAG), intestinal epithelial cells absorb fatty acids and monoacylglycerols that are resynthesized into TAG by enzymes located on the endoplasmic reticulum (ER). A study in rat liver (Abo-Hashema, K. A., M. H. Cake, G. W. Power, and D. J. Clarke. 1999. Evidence for TAG synthesis in the lumen of microsomes via a lipolysis-esterification pathway involving carnitine acyltransferases. J. Biol. Chem. 274: 35577-35582) showed that there is a carnitine-dependent ER lumenal synthesis of TAG. We wanted to test the hypothesis that a similar pathway was present in rat intestine by utilizing etomoxir, a specific inhibitor of carnitine palmitoyltransferase (CPT). Intraduodenal infusion of etomoxir inhibited CPT activity in the ER by 69%. Etomoxir did not affect either the uptake of intraduodenally infused [3H]glyceryltrioleate by the intestinal mucosa or the production of mucosal [3H]TAG, excluding the possibility that etomoxir interfered with TAG absorption or synthesis. Etomoxir did not inhibit protein synthesis, glucose, cholesterol or palmitate absorption or metabolism, or ATP concentrations. Etomoxir substantially (74%) diminished lymph TAG output from intralumenally infused glyceryltrioleate. In conclusion, these data strongly support the hypothesis that an ER CPT system exists and is necessary for processing dietary TAG into chylomicrons. The significant reduction in lymphatic output of chylomicron TAG on etomoxir treatment suggests that the major source of chylomicron TAG is a diacylglyceroltransferase on the lumenal surface of the ER.
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Affiliation(s)
- LaTonya Washington
- Department of Pharmacology, Department of Medicine, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38104, USA
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