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González-Hódar L, McDonald JG, Vale G, Thompson BM, Figueroa AM, Tapia PJ, Robledo F, Agarwal AK, Garg A, Horton JD, Cortés V. Decreased caveolae in AGPAT2 lacking adipocytes is independent of changes in cholesterol or sphingolipid levels: A whole cell and plasma membrane lipidomic analysis of adipogenesis. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166167. [PMID: 33989739 DOI: 10.1016/j.bbadis.2021.166167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/19/2021] [Accepted: 05/04/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND Adipocytes from lipodystrophic Agpat2-/- mice have impaired adipogenesis and fewer caveolae. Herein, we examined whether these defects are associated with changes in lipid composition or abnormal levels of caveolae-associated proteins. Lipidome changes were quantified in differentiated Agpat2-/- adipocytes to identify lipids with potential adipogenic roles. METHODS Agpat2-/- and wild type brown preadipocytes were differentiated in vitro. Plasma membrane was purified by ultracentrifugation. Number of caveolae and caveolae-associated proteins, as well as sterol, sphingolipid, and phospholipid lipidome were determined across differentiation. RESULTS Differentiated Agpat2-/- adipocytes had decreased caveolae number but conserved insulin signaling. Caveolin-1 and cavin-1 levels were equivalent between Agpat2-/- and wild type adipocytes. No differences in PM cholesterol and sphingolipids abundance were detected between genotypes. Levels of phosphatidylserine at day 10 of differentiation were increased in Agpat2-/- adipocytes. Wild type adipocytes had increased whole cell triglyceride, diacylglycerol, phosphatidylglycerol, phosphatidic acid, lysophosphatidylcholine, lysophosphatidylethanolamine, and trihexosyl ceramide, and decreased 24,25-dihydrolanosterol and sitosterol, as a result of adipogenic differentiation. By contrast, adipogenesis did not modify whole cell neutral lipids but increased lysophosphatidylcholine, sphingomyelin, and trihexosyl ceramide levels in Agpat2-/- adipocytes. Unexpectedly, adipogenesis decreased PM levels of main phospholipids in both genotypes. CONCLUSION In Agpat2-/- adipocytes, decreased caveolae is not associated with changes in PM cholesterol nor sphingolipid levels; however, increased PM phosphatidylserine content may be implicated. Abnormal lipid composition is associated with the adipogenic abnormalities of Agpat2 -/- adipocytes but does not prevent insulin signaling.
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Affiliation(s)
- Lila González-Hódar
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile
| | - Jeffrey G McDonald
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, United States
| | - Goncalo Vale
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Bonne M Thompson
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Ana-María Figueroa
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile
| | - Pablo J Tapia
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile
| | - Fermín Robledo
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile
| | - Anil K Agarwal
- Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, TX 75390, United States
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, TX 75390, United States
| | - Jay D Horton
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, United States; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, United States.
| | - Víctor Cortés
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, 8331150, Chile.
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Contreras PS, Tapia PJ, González-Hódar L, Peluso I, Soldati C, Napolitano G, Matarese M, Heras ML, Valls C, Martinez A, Balboa E, Castro J, Leal N, Platt FM, Sobota A, Winter D, Klein AD, Medina DL, Ballabio A, Alvarez AR, Zanlungo S. c-Abl Inhibition Activates TFEB and Promotes Cellular Clearance in a Lysosomal Disorder. iScience 2020; 23:101691. [PMID: 33163944 PMCID: PMC7607485 DOI: 10.1016/j.isci.2020.101691] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/11/2020] [Accepted: 10/13/2020] [Indexed: 12/12/2022] Open
Abstract
The transcription factor EB (TFEB) has emerged as a master regulator of lysosomal biogenesis, exocytosis, and autophagy, promoting the clearance of substrates stored in cells. c-Abl is a tyrosine kinase that participates in cellular signaling in physiological and pathophysiological conditions. In this study, we explored the connection between c-Abl and TFEB. Here, we show that under pharmacological and genetic c-Abl inhibition, TFEB translocates into the nucleus promoting the expression of its target genes independently of its well-known regulator, mammalian target of rapamycin complex 1. Active c-Abl induces TFEB phosphorylation on tyrosine and the inhibition of this kinase promotes lysosomal biogenesis, autophagy, and exocytosis. c-Abl inhibition in Niemann-Pick type C (NPC) models, a neurodegenerative disease characterized by cholesterol accumulation in lysosomes, promotes a cholesterol-lowering effect in a TFEB-dependent manner. Thus, c-Abl is a TFEB regulator that mediates its tyrosine phosphorylation, and the inhibition of c-Abl activates TFEB promoting cholesterol clearance in NPC models. c-Abl is a TFEB regulator that mediates its tyr phosphorylation c-Abl inhibition promotes TFEB activity independently of mTORC1 c-Abl inhibition reduces cholesterol accumulation in NPC1 models
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Affiliation(s)
- Pablo S Contreras
- Department of Cell & Molecular Biology, Biological Sciences Faculty, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile.,CARE UC Pontificia Universidad Católica de Chile, Santiago, Chile.,Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile
| | - Pablo J Tapia
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile
| | - Lila González-Hódar
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile
| | - Ivana Peluso
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Chiara Soldati
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Gennaro Napolitano
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Maria Matarese
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Macarena Las Heras
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile
| | - Cristian Valls
- Department of Cell & Molecular Biology, Biological Sciences Faculty, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile.,CARE UC Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexis Martinez
- Department of Cell & Molecular Biology, Biological Sciences Faculty, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile.,CARE UC Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Elisa Balboa
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile
| | - Juan Castro
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile
| | - Nancy Leal
- Department of Cell & Molecular Biology, Biological Sciences Faculty, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile.,CARE UC Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Andrzej Sobota
- Department of Cell Biology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Dominic Winter
- Institute for Biochemistry and Molecular Biology, Rheinische-Friedrich-Wilhelms-University, Bonn, Germany
| | - Andrés D Klein
- Centro de Genética y Genómica, Universidad Del Desarrollo Clínica Alemana de Santiago, Chile
| | - Diego L Medina
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy.,Medical Genetics, Department of Pediatrics, Federico II University, Via Pansini 5, 80131 Naples, Italy.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Alejandra R Alvarez
- Department of Cell & Molecular Biology, Biological Sciences Faculty, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile.,CARE UC Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Silvana Zanlungo
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile
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Tapia PJ, Figueroa AM, Eisner V, González-Hódar L, Robledo F, Agarwal AK, Garg A, Cortés V. Absence of AGPAT2 impairs brown adipogenesis, increases IFN stimulated gene expression and alters mitochondrial morphology. Metabolism 2020; 111:154341. [PMID: 32810486 DOI: 10.1016/j.metabol.2020.154341] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/29/2020] [Accepted: 08/10/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Biallelic loss of function variants in AGPAT2, encoding 1-acylglycerol-3-phosphate O-acyltransferase 2, cause congenital generalized lipodystrophy type 1, a disease characterized by near total loss of white adipose tissue and metabolic complications. Agpat2 deficient (Agpat2-/-) mice completely lacks both white and interscapular brown adipose tissue (iBAT). The objective of the present study was to characterize the effects of AGPAT2 deficiency in brown adipocyte differentiation. METHODS Preadipocytes obtained from newborn (P0.5) Agpat2-/- and wild type mice iBAT were differentiated into brown adipocytes, compared by RNA microarray, RT-qPCR, High-Content Screening (HCS), western blotting and electron microscopy. RESULTS 1) Differentiated Agpat2-/- brown adipocytes have fewer lipid-laden cells and lower abundance of Pparγ, Pparα, C/ebpα and Pgc1α, both at the mRNA and protein levels, compared those to wild type cells. Prmd16 levels were equivalent in both, Agpat2-/- and wild type, while Ucp1 was only induced in wild type cells, 2) These differences were not due to lower abundance of preadipocytes, 3) Differentiated Agpat2-/- brown adipocytes are enriched in the mRNA abundance of genes participating in interferon (IFN) type I response, whereas genes involved in mitochondrial homeostasis were decreased, 4) Mitochondria in differentiated Agpat2-/- brown adipocytes had altered morphology and lower mass and contacting sites with lipid droplets concomitant with lower levels of Mitofusin 2 and Perlipin 5. CONCLUSION AGPAT2 is necessary for normal brown adipose differentiation. Its absence results in a lower proportion of lipid-laden cells, increased expression of interferon-stimulated genes (ISGs) and alterations in mitochondrial morphology, mass and fewer mitochondria to lipid droplets contacting sites in differentiated brown adipocytes.
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Affiliation(s)
- Pablo J Tapia
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
| | - Ana-María Figueroa
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
| | - Verónica Eisner
- Department of Cellular and Molecular Biology, School of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile.
| | - Lila González-Hódar
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
| | - Fermín Robledo
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
| | - Anil K Agarwal
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States of America.
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States of America.
| | - Víctor Cortés
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile.
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Acuña M, González-Hódar L, Amigo L, Castro J, Morales MG, Cancino GI, Groen AK, Young J, Miquel JF, Zanlungo S. Transgenic overexpression of Niemann-Pick C2 protein promotes cholesterol gallstone formation in mice. J Hepatol 2016; 64:361-369. [PMID: 26453970 DOI: 10.1016/j.jhep.2015.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 09/29/2015] [Accepted: 10/01/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Niemann-Pick C2 (NPC2) is a lysosomal protein involved in the egress of low-density lipoprotein-derived cholesterol from lysosomes to other intracellular compartments. NPC2 has been detected in several tissues and is also secreted from the liver into bile. We have previously shown that NPC2-deficient mice fed a lithogenic diet showed reduced biliary cholesterol secretion as well as cholesterol crystal and gallstone formation. This study aimed to investigate the consequences of NPC2 hepatic overexpression on liver cholesterol metabolism, biliary lipid secretion, gallstone formation and the effect of NPC2 on cholesterol crystallization in model bile. METHODS We generated NPC2 transgenic mice (Npc2.Tg) and fed them either chow or lithogenic diets. We studied liver cholesterol metabolism, biliary lipid secretion, bile acid composition and gallstone formation. We performed cholesterol crystallization studies in model bile using a recombinant NPC2 protein. RESULTS No differences were observed in biliary cholesterol content or secretion between wild-type and Npc2.Tg mice fed the chow or lithogenic diets. Interestingly, Npc2.Tg mice showed an increased susceptibility to the lithogenic diet, developing more cholesterol gallstones at early times, but did not show differences in the bile acid hydrophobicity and gallbladder cholesterol saturation indices compared to wild-type mice. Finally, recombinant NPC2 decreased nucleation time in model bile. CONCLUSIONS These results suggest that NPC2 promotes cholesterol gallstone formation by decreasing the cholesterol nucleation time, indicating a pro-nucleating function of NPC2 in bile.
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Affiliation(s)
- Mariana Acuña
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile; FONDAP "Center for Genome Regulation" (CGR), Santiago, Chile
| | - Lila González-Hódar
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ludwig Amigo
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Castro
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - M Gabriela Morales
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Gonzalo I Cancino
- Neuroscience and Mental Health Program, The Hospital for Sick Children, Toronto, Canada
| | - Albert K Groen
- Departments of Pediatrics/Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Juan Young
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - Juan Francisco Miquel
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile; FONDAP "Center for Genome Regulation" (CGR), Santiago, Chile
| | - Silvana Zanlungo
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile; FONDAP "Center for Genome Regulation" (CGR), Santiago, Chile.
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