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Rullo-Tubau J, Martinez-Molledo M, Bartoccioni P, Puch-Giner I, Arias Á, Saen-Oon S, Stephan-Otto Attolini C, Artuch R, Díaz L, Guallar V, Errasti-Murugarren E, Palacín M, Llorca O. Structure and mechanisms of transport of human Asc1/CD98hc amino acid transporter. Nat Commun 2024; 15:2986. [PMID: 38582862 PMCID: PMC10998858 DOI: 10.1038/s41467-024-47385-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 03/29/2024] [Indexed: 04/08/2024] Open
Abstract
Recent cryoEM studies elucidated details of the structural basis for the substrate selectivity and translocation of heteromeric amino acid transporters. However, Asc1/CD98hc is the only neutral heteromeric amino acid transporter that can function through facilitated diffusion, and the only one that efficiently transports glycine and D-serine, and thus has a regulatory role in the central nervous system. Here we use cryoEM, ligand-binding simulations, mutagenesis, transport assays, and molecular dynamics to define human Asc1/CD98hc determinants for substrate specificity and gain insights into the mechanisms that govern substrate translocation by exchange and facilitated diffusion. The cryoEM structure of Asc1/CD98hc is determined at 3.4-3.8 Å resolution, revealing an inward-facing semi-occluded conformation. We find that Ser 246 and Tyr 333 are essential for Asc1/CD98hc substrate selectivity and for the exchange and facilitated diffusion modes of transport. Taken together, these results reveal the structural bases for ligand binding and transport features specific to human Asc1.
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Affiliation(s)
- Josep Rullo-Tubau
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, E-08028, Barcelona, Spain
| | - Maria Martinez-Molledo
- Structural Biology Programme, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro, 3, E-28029, Madrid, Spain
| | - Paola Bartoccioni
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, E-08028, Barcelona, Spain
- The Spanish Center of Rare Diseases (CIBERER U-731), Baldiri Reixac 10, E-08028, Barcelona, Spain
| | - Ignasi Puch-Giner
- Electronic and atomic protein modelling group, Barcelona Supercomputing Center, Plaça d'Eusebi Güell, 1-3, E-08034, Barcelona, Spain
| | - Ángela Arias
- Clinical Biochemistry Department, Sant Joan de Déu Research Institute, Pg. de Sant Joan de Déu, 2, E-08950, Esplugues de Llobregat, Spain
| | - Suwipa Saen-Oon
- Nostrum Biodiscovery, Av. de Josep Tarradellas, 8-10, E-08029, Barcelona, Spain
| | - Camille Stephan-Otto Attolini
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, E-08028, Barcelona, Spain
| | - Rafael Artuch
- The Spanish Center of Rare Diseases (CIBERER U-731), Baldiri Reixac 10, E-08028, Barcelona, Spain
- Clinical Biochemistry Department, Sant Joan de Déu Research Institute, Pg. de Sant Joan de Déu, 2, E-08950, Esplugues de Llobregat, Spain
| | - Lucía Díaz
- Nostrum Biodiscovery, Av. de Josep Tarradellas, 8-10, E-08029, Barcelona, Spain
| | - Víctor Guallar
- Electronic and atomic protein modelling group, Barcelona Supercomputing Center, Plaça d'Eusebi Güell, 1-3, E-08034, Barcelona, Spain
- Nostrum Biodiscovery, Av. de Josep Tarradellas, 8-10, E-08029, Barcelona, Spain
| | - Ekaitz Errasti-Murugarren
- The Spanish Center of Rare Diseases (CIBERER U-731), Baldiri Reixac 10, E-08028, Barcelona, Spain.
- Physiological Sciences Department, Genetics Area, School of Medicine and Health Sciences, University of Barcelona, Bellvitge Campus. Feixa Llarga s/n, E-08907, L'Hospitalet de Llobregat, Spain.
- Human Molecular Genetics Laboratory, Gene, Disease and Therapy Program, IDIBELL, Hospital Duran i Reynals, Avd. Gran Via de L'Hospitalet 199, E-08908, L'Hospitalet de Llobregat, Spain.
| | - Manuel Palacín
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, E-08028, Barcelona, Spain.
- The Spanish Center of Rare Diseases (CIBERER U-731), Baldiri Reixac 10, E-08028, Barcelona, Spain.
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Av. Diagonal, 643, E-08028, Barcelona, Spain.
| | - Oscar Llorca
- Structural Biology Programme, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro, 3, E-28029, Madrid, Spain.
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2
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Zhang CY, Peng XX, Wu Y, Peng MJ, Liu TH, Tan ZJ. Intestinal mucosal microbiota mediate amino acid metabolism involved in the gastrointestinal adaptability to cold and humid environmental stress in mice. Microb Cell Fact 2024; 23:33. [PMID: 38267983 PMCID: PMC10809741 DOI: 10.1186/s12934-024-02307-2] [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: 10/11/2023] [Accepted: 01/14/2024] [Indexed: 01/26/2024] Open
Abstract
Growing evidence has demonstrated that cold and humid environmental stress triggers gastrointestinal (GI) disorders. In this study, we explored the effects of intestinal microbiota homeostasis on the intestinal mucus barrier and GI disorders by cold and humid environmental stress. Moreover, the inner link between the intestinal mucosal microbiota and metabolites in mice with cold and humid environmental stress was interpreted by integrative analysis of PacBio HiFi sequencing microbial genomics and targeted metabolomics. In the current study, we found (1) after the cold and wet cold and humid environmental stress intervened in the intestinal microbiota disorder and homeostasis mice respectively, the bacterial culturing and fluorescein diacetate (FDA) microbial activity detection of intestinal microbiota including feces, intestinal contents, and intestinal mucosa suggested that the cold and humid environmental stress decreased the colony of culturable bacteria and microbial activity, in which intestinal microbiota disorder aggravated the injury of the intestinal mucus barrier and the GI symptoms related to cold and humid environmental stress; (2) the serum amino acid transferases such as glutamate pyruvic transa (GPT), and glutamic oxaloacetic transaminase (GOT) in cold and humid environmental stressed mice increased significantly, indicating that the intestinal microbiota adapted to cold and humid environmental stress by regulating the host's amino acid metabolism; (3) the integrative analysis of multi-omics illustrated a prediction model based on the microbiota Lactobacillus reuteri abundance and host amino acid level that can predict intestinal mucoprotein Muc2 with an adjusted R2 of 75.0%. In conclusion, the cold and humid environmental stress regulates the neurotransmitter amino acids metabolic function both in intestinal mucosal microbiota and host serum by adjusting the composition of the dominant bacterial population Lactobacillus reuteri, which contributes to the intestinal mucus barrier injury and GI disorders caused by cold and humid environmental stress.
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Affiliation(s)
- Chen-Yang Zhang
- College of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha, China
| | - Xin-Xin Peng
- Department of Pediatrics, The First Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, China
| | - Yi Wu
- College of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha, China
| | - Mai-Jiao Peng
- College of Pharmacy, Hunan University of Chinese Medicine, Changsha, China
| | - Tiao-Hao Liu
- Department of Gastroenterology, Affiliated Hospital of Jiangnan University, Wuxi, China.
| | - Zhou-Jin Tan
- College of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha, China.
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Allebrandt Neto EW, Rondon E Silva J, Santos SF, de França Lemes SA, Kawashita NH, Peron Pereira M. The futile creatine cycle and the synthesis of fatty acids in inguinal white adipose tissue from growing rats, submitted to a hypoprotein-hyperglycidic diet for 15 days. Lipids 2024; 59:3-12. [PMID: 38223990 DOI: 10.1002/lipd.12384] [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: 01/30/2023] [Revised: 11/30/2023] [Accepted: 01/02/2024] [Indexed: 01/16/2024]
Abstract
The low-protein, high-carbohydrate (LPHC) diet administered to growing rats soon after weaning, for 15 days, promoted an increase in energy expenditure by uncoupling protein 1 (UCP1) in interscapular brown adipose tissue, and also due to the occurrence of the browning process in the perirenal white adipose tissue (periWAT). However, we believe that inguinal white adipose tissue (ingWAT) may also contribute to energy expenditure through other mechanisms. Therefore, the aim of this work is to investigate the presence of the futile creatine cycle, and the origin of lipids in ingWAT, since that tissue showed an increase in the lipids content in rats submitted to the LPHC diet for 15 days. We observed increases in creatine kinase and alkaline phosphatase activity in ingWAT, of the LPHC animals. The mitochondrial Nicotinamide adenine dinucleotide reduced/nicotinamide adenine dinucleotide oxidized ratio is lower in ingWAT of LPHC animals. In the LPHC animals treated with β-guanidinopropionic acid, the extracellular uptake of creatine in ingWAT was lower, as was the rectal temperature. Regarding lipid metabolism, we observed that in ingWAT, lipolysis in vitro when stimulated with noradrenaline is lower, and there were no changes in baseline levels. In addition, increases in the activity of enzymes were also observed: malic, glucose-6-phosphate dehydrogenase, and ATP-citrate lyase, in addition to an increase in the PPARγ content. The results show the occurrence of the futile creatine cycle in ingWAT, and that the increase in the relative mass may be due to an increase in de novo fatty acid synthesis.
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Affiliation(s)
| | | | | | | | - Nair Honda Kawashita
- Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Mayara Peron Pereira
- Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil
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4
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Huang Z, Gu C, Zhang Z, Arianti R, Swaminathan A, Tran K, Battist A, Kristóf E, Ruan HB. Supraclavicular brown adipocytes originate from Tbx1+ myoprogenitors. PLoS Biol 2023; 21:e3002413. [PMID: 38048357 PMCID: PMC10721186 DOI: 10.1371/journal.pbio.3002413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 12/14/2023] [Accepted: 10/31/2023] [Indexed: 12/06/2023] Open
Abstract
Brown adipose tissue (BAT) dissipates energy as heat, contributing to temperature control, energy expenditure, and systemic homeostasis. In adult humans, BAT mainly exists in supraclavicular areas and its prevalence is associated with cardiometabolic health. However, the developmental origin of supraclavicular BAT remains unknown. Here, using genetic cell marking in mice, we demonstrate that supraclavicular brown adipocytes do not develop from the Pax3+/Myf5+ epaxial dermomyotome that gives rise to interscapular BAT (iBAT). Instead, the Tbx1+ lineage that specifies the pharyngeal mesoderm marks the majority of supraclavicular brown adipocytes. Tbx1Cre-mediated ablation of peroxisome proliferator-activated receptor gamma (PPARγ) or PR/SET Domain 16 (PRDM16), components of the transcriptional complex for brown fat determination, leads to supraclavicular BAT paucity or dysfunction, thus rendering mice more sensitive to cold exposure. Moreover, human deep neck BAT expresses higher levels of the TBX1 gene than subcutaneous neck white adipocytes. Taken together, our observations reveal location-specific developmental origins of BAT depots and call attention to Tbx1+ lineage cells when investigating human relevant supraclavicular BAT.
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Affiliation(s)
- Zan Huang
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Chenxin Gu
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Zengdi Zhang
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Rini Arianti
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Aneesh Swaminathan
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Kevin Tran
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Alex Battist
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Endre Kristóf
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Hai-Bin Ruan
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
- Center for Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
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Hammad SM, Lopes-Virella MF. Circulating Sphingolipids in Insulin Resistance, Diabetes and Associated Complications. Int J Mol Sci 2023; 24:14015. [PMID: 37762318 PMCID: PMC10531201 DOI: 10.3390/ijms241814015] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Sphingolipids play an important role in the development of diabetes, both type 1 and type 2 diabetes, as well as in the development of both micro- and macro-vascular complications. Several reviews have been published concerning the role of sphingolipids in diabetes but most of the emphasis has been on the possible mechanisms by which sphingolipids, mainly ceramides, contribute to the development of diabetes. Research on circulating levels of the different classes of sphingolipids in serum and in lipoproteins and their importance as biomarkers to predict not only the development of diabetes but also of its complications has only recently emerged and it is still in its infancy. This review summarizes the previously published literature concerning sphingolipid-mediated mechanisms involved in the development of diabetes and its complications, focusing on how circulating plasma sphingolipid levels and the relative content carried by the different lipoproteins may impact their role as possible biomarkers both in the development of diabetes and mainly in the development of diabetic complications. Further studies in this field may open new therapeutic avenues to prevent or arrest/reduce both the development of diabetes and progression of its complications.
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Affiliation(s)
- Samar M. Hammad
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Maria F. Lopes-Virella
- Division of Endocrinology, Diabetes and Medical Genetics, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
- Ralph H. Johnson VA Medical Center, Charleston, SC 29425, USA
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Vinnai BÁ, Arianti R, Győry F, Bacso Z, Fésüs L, Kristóf E. Extracellular thiamine concentration influences thermogenic competency of differentiating neck area-derived human adipocytes. Front Nutr 2023; 10:1207394. [PMID: 37781121 PMCID: PMC10534038 DOI: 10.3389/fnut.2023.1207394] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/14/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction Brown adipose tissue (BAT) dissipates energy in the form of heat majorly via the mitochondrial uncoupling protein 1 (UCP1). The activation of BAT, which is enriched in the neck area and contains brown and beige adipocytes in humans, was considered as a potential therapeutic target to treat obesity. Therefore, finding novel agents that can stimulate the differentiation and recruitment of brown or beige thermogenic adipocytes are important subjects for investigation. The current study investigated how the availability of extracellular thiamine (vitamin B1), an essential cofactor of mitochondrial enzyme complexes that catalyze key steps in the catabolism of nutrients, affects the expression of thermogenic marker genes and proteins and subsequent functional parameters during ex vivo adipocyte differentiation. Methods We differentiated primary human adipogenic progenitors that were cultivated from subcutaneous (SC) or deep neck (DN) adipose tissues in the presence of gradually increasing thiamine concentrations during their 14-day differentiation program. mRNA and protein expression of thermogenic genes were analyzed by RT-qPCR and western blot, respectively. Cellular respiration including stimulated maximal and proton-leak respiration was measured by Seahorse analysis. Results Higher thiamine levels resulted in increased expression of thiamine transporter 1 and 2 both at mRNA and protein levels in human neck area-derived adipocytes. Gradually increasing concentrations of thiamine led to increased basal, cAMP-stimulated, and proton-leak respiration along with elevated mitochondrial biogenesis of the differentiated adipocytes. The extracellular thiamine availability during adipogenesis determined the expression levels of UCP1, PGC1a, CKMT2, and other browning-related genes and proteins in primary SC and DN-derived adipocytes in a concentration-dependent manner. Providing abundant amounts of thiamine further increased the thermogenic competency of the adipocytes. Discussion Case studies in humans reported that thiamine deficiency was found in patients with type 2 diabetes and obesity. Our study raises the possibility of a novel strategy with long-term thiamine supplementation, which can enhance the thermogenic competency of differentiating neck area-derived adipocytes for preventing or combating obesity.
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Affiliation(s)
- Boglárka Ágnes Vinnai
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Rini Arianti
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Universitas Muhammadiyah Bangka Belitung, Pangkalanbaru, Indonesia
| | - Ferenc Győry
- Department of Surgery, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zsolt Bacso
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - László Fésüs
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Endre Kristóf
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Jersin RÅ, Sri Priyanka Tallapragada D, Skartveit L, Bjune MS, Muniandy M, Lee-Ødegård S, Heinonen S, Alvarez M, Birkeland KI, André Drevon C, Pajukanta P, McCann A, Pietiläinen KH, Claussnitzer M, Mellgren G, Dankel SN. Impaired Adipocyte SLC7A10 Promotes Lipid Storage in Association With Insulin Resistance and Altered BCAA Metabolism. J Clin Endocrinol Metab 2023; 108:2217-2229. [PMID: 36916878 PMCID: PMC10438883 DOI: 10.1210/clinem/dgad148] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 02/23/2023] [Accepted: 03/07/2023] [Indexed: 03/16/2023]
Abstract
CONTEXT The neutral amino acid transporter SLC7A10/ASC-1 is an adipocyte-expressed gene with reduced expression in insulin resistance and obesity. Inhibition of SLC7A10 in adipocytes was shown to increase lipid accumulation despite decreasing insulin-stimulated uptake of glucose, a key substrate for de novo lipogenesis. These data imply that alternative lipogenic substrates to glucose fuel continued lipid accumulation during insulin resistance in obesity. OBJECTIVE We examined whether increased lipid accumulation during insulin resistance in adipocytes may involve alter flux of lipogenic amino acids dependent on SLC7A10 expression and activity, and whether this is reflected by extracellular and circulating concentrations of marker metabolites. METHODS In adipocyte cultures with impaired SLC7A10, we performed RNA sequencing and relevant functional assays. By targeted metabolite analyses (GC-MS/MS), flux of all amino acids and selected metabolites were measured in human and mouse adipose cultures. Additionally, SLC7A10 mRNA levels in human subcutaneous adipose tissue (SAT) were correlated to candidate metabolites and adiposity phenotypes in 2 independent cohorts. RESULTS SLC7A10 impairment altered expression of genes related to metabolic processes, including branched-chain amino acid (BCAA) catabolism, lipogenesis, and glyceroneogenesis. In 3T3-L1 adipocytes, SLC7A10 inhibition increased fatty acid uptake and cellular content of glycerol and cholesterol. SLC7A10 impairment in SAT cultures altered uptake of aspartate and glutamate, and increased net uptake of BCAAs, while increasing the net release of the valine catabolite 3- hydroxyisobutyrate (3-HIB). In human cohorts, SLC7A10 mRNA correlated inversely with total fat mass, circulating triacylglycerols, BCAAs, and 3-HIB. CONCLUSION Reduced SLC7A10 activity strongly affects flux of BCAAs in adipocytes, which may fuel continued lipogenesis during insulin resistance, and be reflected in increased circulating levels of the valine-derived catabolite 3-HIB.
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Affiliation(s)
- Regine Å Jersin
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Divya Sri Priyanka Tallapragada
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Linn Skartveit
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Mona S Bjune
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Maheswary Muniandy
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, FIN-00014 Helsinki, Finland
| | - Sindre Lee-Ødegård
- Department of Transplantation Medicine, The University of Oslo, Institute of Clinical Medicine, and Oslo University Hospital, N-0372 Oslo, Norway
| | - Sini Heinonen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, FIN-00014 Helsinki, Finland
| | - Marcus Alvarez
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Kåre Inge Birkeland
- Department of Transplantation Medicine, The University of Oslo, Institute of Clinical Medicine, and Oslo University Hospital, N-0372 Oslo, Norway
| | - Christian André Drevon
- Department of Nutrition, The University of Oslo, Institute of Basic Medical Sciences, N-0372 Oslo, Norway
| | - Päivi Pajukanta
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Bioinformatics Interdepartmental Program, UCLA, Los Angeles, CA 90095, USA
- Institute for Precision Health, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Adrian McCann
- Bevital A/S, Laboratoriebygget, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Kirsi H Pietiläinen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, FIN-00014 Helsinki, Finland
- Obesity Center, Endocrinology, Abdominal Center, Helsinki University Hospital and University of Helsinki, FIN-00014 Helsinki, Finland
| | - Melina Claussnitzer
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Gunnar Mellgren
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Simon N Dankel
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, N-5021 Bergen, Norway
- Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, N-5021 Bergen, Norway
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Shaw A, Kristóf E, Cereijo R. Editorial: Novel regulatory mechanisms behind thermogenesis of brown and beige adipocytes. Front Endocrinol (Lausanne) 2023; 14:1268299. [PMID: 37664834 PMCID: PMC10471955 DOI: 10.3389/fendo.2023.1268299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 08/09/2023] [Indexed: 09/05/2023] Open
Affiliation(s)
- Abhirup Shaw
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, QC, Canada
| | - Endre Kristóf
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Rubén Cereijo
- Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina de la Universitat de Barcelona (IBUB), and Institut de Recerca de Sant Joan de Déu, Universitat de Barcelona, Barcelona, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición, Madrid, Spain
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9
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Vámos A, Arianti R, Vinnai BÁ, Alrifai R, Shaw A, Póliska S, Guba A, Csősz É, Csomós I, Mocsár G, Lányi C, Balajthy Z, Fésüs L, Kristóf E. Human abdominal subcutaneous-derived active beige adipocytes carrying FTO rs1421085 obesity-risk alleles exert lower thermogenic capacity. Front Cell Dev Biol 2023; 11:1155673. [PMID: 37416800 PMCID: PMC10321670 DOI: 10.3389/fcell.2023.1155673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/26/2023] [Indexed: 07/08/2023] Open
Abstract
Introduction: White adipocytes store lipids, have a large lipid droplet and few mitochondria. Brown and beige adipocytes, which produce heat, are characterized by high expression of uncoupling protein (UCP) 1, multilocular lipid droplets, and large amounts of mitochondria. The rs1421085 T-to-C single-nucleotide polymorphism (SNP) of the human FTO gene interrupts a conserved motif for ARID5B repressor, resulting in adipocyte type shift from beige to white. Methods: We obtained abdominal subcutaneous adipose tissue from donors carrying FTO rs1421085 TT (risk-free) or CC (obesity-risk) genotypes, isolated and differentiated their preadipocytes into beige adipocytes (driven by the PPARγ agonist rosiglitazone for 14 days), and activated them with dibutyryl-cAMP for 4 hours. Then, either the same culture conditions were applied for additional 14 days (active beige adipocytes) or it was replaced by a white differentiation medium (inactive beige adipocytes). White adipocytes were differentiated by their medium for 28 days. Results and Discussion: RNA-sequencing was performed to investigate the gene expression pattern of adipocytes carrying different FTO alleles and found that active beige adipocytes had higher brown adipocyte content and browning capacity compared to white or inactive beige ones when the cells were obtained from risk-free TT but not from obesity-risk CC genotype carriers. Active beige adipocytes carrying FTO CC had lower thermogenic gene (e.g., UCP1, PM20D1, CIDEA) expression and thermogenesis measured by proton leak respiration as compared to TT carriers. In addition, active beige adipocytes with CC alleles exerted lower expression of ASC-1 neutral amino acid transporter (encoded by SLC7A10) and less consumption of Ala, Ser, Cys, and Gly as compared to risk-free carriers. We did not observe any influence of the FTO rs1421085 SNP on white and inactive beige adipocytes highlighting its exclusive and critical effect when adipocytes were activated for thermogenesis.
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Affiliation(s)
- Attila Vámos
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Rini Arianti
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Universitas Muhammadiyah Bangka Belitung, Pangkalanbaru, Indonesia
| | - Boglárka Ágnes Vinnai
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Rahaf Alrifai
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Abhirup Shaw
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Szilárd Póliska
- Genomic Medicine and Bioinformatics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Andrea Guba
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
- Proteomics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Éva Csősz
- Proteomics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - István Csomós
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | | | - Zoltán Balajthy
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Fésüs
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Endre Kristóf
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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10
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Arianti R, Ágnes Vinnai B, Győry F, Guba A, Csősz É, Kristóf E, Fésüs L. Availability of abundant thiamine determines efficiency of thermogenic activation in human neck area derived adipocytes. J Nutr Biochem 2023:109385. [PMID: 37230255 DOI: 10.1016/j.jnutbio.2023.109385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/23/2022] [Accepted: 05/20/2023] [Indexed: 05/27/2023]
Abstract
Brown/beige adipocytes express uncoupling protein-1 (UCP1) that enables them to dissipate energy as heat. Systematic activation of this process can alleviate obesity. Human brown adipose tissues are interspersed in distinct anatomical regions including deep neck. We found that UCP1 enriched adipocytes differentiated from precursors of this depot highly expressed ThTr2 transporter of thiamine and consumed thiamine during thermogenic activation of these adipocytes by cAMP which mimics adrenergic stimulation. Inhibition of ThTr2 led to lower thiamine consumption with decreased proton leak respiration reflecting reduced uncoupling. In the absence of thiamine, cAMP-induced uncoupling was diminished but restored by thiamine addition reaching the highest levels at thiamine concentrations larger than present in human blood plasma. Thiamine is converted to thiamine pyrophosphate (TPP) in cells; the addition of TPP to permeabilized adipocytes increased uncoupling fueled by TPP-dependent pyruvate dehydrogenase. ThTr2 inhibition also hampered cAMP-dependent induction of UCP1, PGC1a, and other browning marker genes, and thermogenic induction of these genes was potentiated by thiamine in a concentration dependent manner. Our study reveals the importance of amply supplied thiamine during thermogenic activation in human adipocytes which provides TPP for TPP-dependent enzymes not fully saturated with this cofactor and by potentiating the induction of thermogenic genes.
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Affiliation(s)
- Rini Arianti
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4032, Debrecen, Hungary; Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, H-4032, Debrecen, Hungary
| | - Boglárka Ágnes Vinnai
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4032, Debrecen, Hungary; Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, H-4032, Debrecen, Hungary
| | - Ferenc Győry
- Department of Surgery, Faculty of Medicine, University of Debrecen, H-4032, Debrecen, Hungary
| | - Andrea Guba
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4032, Debrecen, Hungary; Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, H-4032, Debrecen, Hungary
| | - Éva Csősz
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4032, Debrecen, Hungary
| | - Endre Kristóf
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4032, Debrecen, Hungary.
| | - László Fésüs
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4032, Debrecen, Hungary.
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11
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Jersin RÅ, Jonassen LR, Dankel SN. The neutral amino acid transporter SLC7A10 in adipose tissue, obesity and insulin resistance. Front Cell Dev Biol 2022; 10:974338. [PMID: 36172277 PMCID: PMC9512047 DOI: 10.3389/fcell.2022.974338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 08/26/2022] [Indexed: 12/02/2022] Open
Abstract
Obesity, insulin resistance and type 2 diabetes represent major global health challenges, and a better mechanistic understanding of the altered metabolism in these conditions may give improved treatment strategies. SLC7A10, a member of the SLC7 subfamily of solute carriers, also named ASC-1 (alanine, serine, cysteine transporter-1), has recently been implicated as an important modulator of core processes in energy- and lipid metabolism, through its particularly high expression in adipocytes. In human cohorts, adipose SLC7A10 mRNA shows strong inverse correlations with insulin resistance, adipocyte size and components of the metabolic syndrome, strong heritability, and an association with type 2 diabetes risk alleles. SLC7A10 has been proposed as a marker of white as opposed to thermogenic beige and brown adipocytes, supported by increased formation of thermogenic beige adipocytes upon loss of Slc7a10 in mouse white preadipocytes. Overexpression of SLC7A10 in mature white adipocytes was found to lower the generation of reactive oxygen species (ROS) and stimulate mitochondrial respiratory capacity, while SLC7A10 inhibition had the opposite effect, indicating that SLC7A10 supports a beneficial increase in mitochondrial activity in white adipocytes. Consistent with these beneficial effects, inhibition of SLC7A10 was in mouse and human white adipocyte cultures found to increase lipid accumulation, likely explained by lowered serine uptake and glutathione production. Additionally, zebrafish with partial global Slc7a10b loss-of-function were found to have greater diet-induced body weight and larger visceral adipocytes compared to controls. However, challenging that SLC7A10 exerts metabolic benefits only in white adipocytes, suppression of SLC7A10 has been reported to decrease mitochondrial respiration and expression of thermogenic genes also in some beige and brown adipocyte cultures. Taken together, the data point to an important but complex role of SLC7A10 in metabolic regulation across different adipose tissue depots and adipocyte subtypes. Further research into SLC7A10 functions in specific adipocyte subtypes may lead to new precision therapeutics for mitigating the risk of insulin resistance and type 2 diabetes.
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Affiliation(s)
- Regine Åsen Jersin
- Hormone Laboratory, Haukeland University Hospital, Bergen, Norway
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Laura Roxana Jonassen
- Hormone Laboratory, Haukeland University Hospital, Bergen, Norway
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Simon Nitter Dankel
- Hormone Laboratory, Haukeland University Hospital, Bergen, Norway
- Mohn Nutrition Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway
- *Correspondence: Simon Nitter Dankel,
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12
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Onogi Y, Ussar S. Regulatory networks determining substrate utilization in brown adipocytes. Trends Endocrinol Metab 2022; 33:493-506. [PMID: 35491296 DOI: 10.1016/j.tem.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/25/2022] [Accepted: 04/05/2022] [Indexed: 11/16/2022]
Abstract
Brown adipose tissue (BAT) is often considered as a sink for nutrients to generate heat. However, when the complex hormonal and nervous inputs and intracellular signaling networks regulating substrate utilization are considered, BAT appears much more as a tightly controlled rheostat, regulating body temperature and balancing circulating nutrient levels. Here we provide an overview of key regulatory circuits, including the diurnal rhythm, determining glucose, fatty acid, and amino acid utilization and the interdependency of these nutrients in thermogenesis. Moreover, we discuss additional factors mediating sympathetic BAT activation beyond β-adrenergic signaling and the limitations of glucose-based BAT activity measurements to foster a better understanding and interpretation of BAT activity data.
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Affiliation(s)
- Yasuhiro Onogi
- RG Adipocytes & Metabolism, Institute for Diabetes & Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
| | - Siegfried Ussar
- RG Adipocytes & Metabolism, Institute for Diabetes & Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Department of Medicine, Technische Universität München, Munich, Germany.
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13
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Lénárt K, Bankó C, Ujlaki G, Póliska S, Kis G, Csősz É, Antal M, Bacso Z, Bai P, Fésüs L, Mádi A. Tissue Transglutaminase Knock-Out Preadipocytes and Beige Cells of Epididymal Fat Origin Possess Decreased Mitochondrial Functions Required for Thermogenesis. Int J Mol Sci 2022; 23:5175. [PMID: 35563567 PMCID: PMC9105016 DOI: 10.3390/ijms23095175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 11/24/2022] Open
Abstract
Beige adipocytes with thermogenic function are activated during cold exposure in white adipose tissue through the process of browning. These cells, similar to brown adipocytes, dissipate stored chemical energy in the form of heat with the help of uncoupling protein 1 (UCP1). Recently, we have shown that tissue transglutaminase (TG2) knock-out mice have decreased cold tolerance in parallel with lower utilization of their epididymal adipose tissue and reduced browning. To learn more about the thermogenic function of this fat depot, we isolated preadipocytes from the epididymal adipose tissue of wild-type and TG2 knock-out mice and differentiated them in the beige direction. Although differentiation of TG2 knock-out preadipocytes is phenotypically similar to the wild-type cells, the mitochondria of the knock-out beige cells have multiple impairments including an altered electron transport system generating lower electrochemical potential difference, reduced oxygen consumption, lower UCP1 protein content, and a higher portion of fragmented mitochondria. Most of these differences are present in preadipocytes as well, and the differentiation process cannot overcome the functional disadvantages completely. TG2 knock-out beige adipocytes produce more iodothyronine deiodinase 3 (DIO3) which may inactivate thyroid hormones required for the establishment of optimal mitochondrial function. The TG2 knock-out preadipocytes and beige cells are both hypometabolic as compared with the wild-type controls which may also be explained by the lower expression of solute carrier proteins SLC25A45, SLC25A47, and SLC25A42 which transport acylcarnitine, Co-A, and amino acids into the mitochondrial matrix. As a consequence, the mitochondria in TG2 knock-out beige adipocytes probably cannot reach the energy-producing threshold required for normal thermogenic functions, which may contribute to the decreased cold tolerance of TG2 knock-out mice.
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Affiliation(s)
- Kinga Lénárt
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary; (K.L.); (S.P.); (É.C.); (L.F.)
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary;
| | - Csaba Bankó
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary;
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary;
| | - Gyula Ujlaki
- NKFIH-DE Lendület Laboratory of Cellular Metabolism, Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary; (G.U.); (P.B.)
| | - Szilárd Póliska
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary; (K.L.); (S.P.); (É.C.); (L.F.)
| | - Gréta Kis
- Department of Anatomy, Histology Embryology, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary; (G.K.); (M.A.)
| | - Éva Csősz
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary; (K.L.); (S.P.); (É.C.); (L.F.)
| | - Miklós Antal
- Department of Anatomy, Histology Embryology, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary; (G.K.); (M.A.)
| | - Zsolt Bacso
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary;
| | - Péter Bai
- NKFIH-DE Lendület Laboratory of Cellular Metabolism, Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary; (G.U.); (P.B.)
- Research Center for Molecular Medicine, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary
| | - László Fésüs
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary; (K.L.); (S.P.); (É.C.); (L.F.)
| | - András Mádi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1., H-4032 Debrecen, Hungary; (K.L.); (S.P.); (É.C.); (L.F.)
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14
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Mitophagy Mediates the Beige to White Transition of Human Primary Subcutaneous Adipocytes Ex Vivo. Pharmaceuticals (Basel) 2022; 15:ph15030363. [PMID: 35337160 PMCID: PMC8948887 DOI: 10.3390/ph15030363] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 12/12/2022] Open
Abstract
Brown and beige adipocytes have multilocular lipid droplets, express uncoupling protein (UCP) 1, and promote energy expenditure. In rodents, when the stimulus of browning subsides, parkin-dependent mitophagy is activated and dormant beige adipocytes persist. In humans, however, the molecular events during the beige to white transition have not been studied in detail. In this study, human primary subcutaneous abdominal preadipocytes were differentiated to beige for 14 days, then either the beige culture conditions were applied for an additional 14 days or it was replaced by a white medium. Control white adipocytes were differentiated by their specific cocktail for 28 days. Peroxisome proliferator-activated receptor γ-driven beige differentiation resulted in increased mitochondrial biogenesis, UCP1 expression, fragmentation, and respiration as compared to white. Morphology, UCP1 content, mitochondrial fragmentation, and basal respiration of the adipocytes that underwent transition, along with the induction of mitophagy, were similar to control white adipocytes. However, white converted beige adipocytes had a stronger responsiveness to dibutyril-cAMP, which mimics adrenergic stimulus, than the control white ones. Gene expression patterns showed that the removal of mitochondria in transitioning adipocytes may involve both parkin-dependent and -independent pathways. Preventing the entry of beige adipocytes into white transition can be a feasible way to maintain elevated thermogenesis and energy expenditure.
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15
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Bröer S. Amino acid transporters as modulators of glucose homeostasis. Trends Endocrinol Metab 2022; 33:120-135. [PMID: 34924221 DOI: 10.1016/j.tem.2021.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 11/01/2021] [Accepted: 11/18/2021] [Indexed: 12/18/2022]
Abstract
Amino acids modulate glucose homeostasis. Cytosolic levels of amino acids are regulated by amino acid transporters, modulating insulin release, protein synthesis, cell proliferation, cell fate, and metabolism. In β-cells, amino acid transporters modulate incretin-stimulated insulin release. In the liver, amino acid transporters provide glutamine and alanine for gluconeogenesis. Intestinal amino acid transporters facilitate the intake of amino acids causing protein restriction when inactive. Adipocyte development is regulated by amino acid transporters through activation of mechanistic target of rapamycin (mTORC1) and amino acid-related metabolites. The accumulation and metabolism of branched-chain amino acids (BCAAs) in muscle depends on transporters. The integration between amino acid metabolism and transport is critical for the maintenance and function of tissues and cells involved in glucose homeostasis.
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Affiliation(s)
- Stefan Bröer
- Research School of Biology, Australian National University, Acton 2601, Australia.
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16
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BMP7 Increases UCP1-Dependent and Independent Thermogenesis with a Unique Gene Expression Program in Human Neck Area Derived Adipocytes. Pharmaceuticals (Basel) 2021; 14:ph14111078. [PMID: 34832860 PMCID: PMC8625022 DOI: 10.3390/ph14111078] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 12/26/2022] Open
Abstract
White adipocytes contribute to energy storage, accumulating lipid droplets, whereas brown and beige adipocytes mainly function in dissipating energy as heat primarily via the action of uncoupling protein 1 (UCP1). Bone morphogenic protein 7 (BMP7) was shown to drive brown adipocyte differentiation in murine interscapular adipose tissue. Here, we performed global RNA-sequencing and functional assays on adipocytes obtained from subcutaneous (SC) and deep-neck (DN) depots of human neck and differentiated with or without BMP7. We found that BMP7 did not influence differentiation but upregulated browning markers, including UCP1 mRNA and protein in SC and DN derived adipocytes. BMP7 also enhanced mitochondrial DNA content, levels of oxidative phosphorylation complex subunits, along with PGC1α and p-CREB upregulation, and fragmentation of mitochondria. Furthermore, both UCP1-dependent proton leak and UCP1-independent, creatine-driven substrate cycle coupled thermogenesis were augmented upon BMP7 addition. The gene expression analysis also shed light on the possible role of genes unrelated to thermogenesis thus far, including ACAN, CRYAB, and ID1, which were among the highest upregulated ones by BMP7 treatment in both types of adipocytes. Together, our study shows that BMP7 strongly upregulates thermogenesis in human neck area derived adipocytes, along with genes, which might have a supporting role in energy expenditure.
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