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Shin J, Toyoda S, Okuno Y, Hayashi R, Nishitani S, Onodera T, Sakamoto H, Ito S, Kobayashi S, Nagao H, Kita S, Otsuki M, Fukuhara A, Nagata K, Shimomura I. HSP47 levels determine the degree of body adiposity. Nat Commun 2023; 14:7319. [PMID: 37951979 PMCID: PMC10640548 DOI: 10.1038/s41467-023-43080-x] [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: 03/09/2023] [Accepted: 10/31/2023] [Indexed: 11/14/2023] Open
Abstract
Adiposity varies among individuals with the influence of diverse physiological, pathological, environmental, hormonal, and genetic factors, but a unified molecular basis remains elusive. Here, we identify HSP47, a collagen-specific chaperone, as a key determinant of body adiposity. HSP47 expression is abundant in adipose tissue; increased with feeding, overeating, and obesity; decreased with fasting, exercise, calorie restriction, bariatric surgery, and cachexia; and correlated with fat mass, BMI, waist, and hip circumferences. Insulin and glucocorticoids, respectively, up- and down-regulate HSP47 expression. In humans, the increase of HSP47 gene expression by its intron or synonymous variants is associated with higher body adiposity traits. In mice, the adipose-specific knockout or pharmacological inhibition of HSP47 leads to lower body adiposity compared to the control. Mechanistically, HSP47 promotes collagen dynamics in the folding, secretion, and interaction with integrin, which activates FAK signaling and preserves PPARγ protein from proteasomal degradation, partly related to MDM2. The study highlights the significance of HSP47 in determining the amount of body fat individually and under various circumstances.
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Affiliation(s)
- Jihoon Shin
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
- Department of Diabetes Care Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
| | - Shinichiro Toyoda
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Yosuke Okuno
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Reiko Hayashi
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Shigeki Nishitani
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Toshiharu Onodera
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, USA
| | - Haruyo Sakamoto
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Shinya Ito
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
| | - Sachiko Kobayashi
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Hirofumi Nagao
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Shunbun Kita
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
- Department of Adipose Management, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Michio Otsuki
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
- Department of Endocrinology, Graduate School of Medical Science, Tokyo Women's Medical University, Tokyo, Japan
| | - Atsunori Fukuhara
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
- Department of Adipose Management, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Kazuhiro Nagata
- Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, Japan
- JT Biohistory Research Hall, Osaka, Japan
| | - Iichiro Shimomura
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
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2
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Bäckdahl J, Franzén L, Massier L, Li Q, Jalkanen J, Gao H, Andersson A, Bhalla N, Thorell A, Rydén M, Ståhl PL, Mejhert N. Spatial mapping reveals human adipocyte subpopulations with distinct sensitivities to insulin. Cell Metab 2021; 33:1869-1882.e6. [PMID: 34380013 DOI: 10.1016/j.cmet.2021.07.018] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/21/2021] [Accepted: 07/26/2021] [Indexed: 12/21/2022]
Abstract
The contribution of cellular heterogeneity and architecture to white adipose tissue (WAT) function is poorly understood. Herein, we combined spatially resolved transcriptional profiling with single-cell RNA sequencing and image analyses to map human WAT composition and structure. This identified 18 cell classes with unique propensities to form spatially organized homo- and heterotypic clusters. Of these, three constituted mature adipocytes that were similar in size, but distinct in their spatial arrangements and transcriptional profiles. Based on marker genes, we termed these AdipoLEP, AdipoPLIN, and AdipoSAA. We confirmed, in independent datasets, that their respective gene profiles associated differently with both adipocyte and whole-body insulin sensitivity. Corroborating our observations, insulin stimulation in vivo by hyperinsulinemic-euglycemic clamp showed that only AdipoPLIN displayed a transcriptional response to insulin. Altogether, by mining this multimodal resource we identify that human WAT is composed of three classes of mature adipocytes, only one of which is insulin responsive.
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Affiliation(s)
- Jesper Bäckdahl
- Department of Medicine (H7), Karolinska Institutet, C2-94, Karolinska University Hospital, 141 86 Stockholm, Sweden
| | - Lovisa Franzén
- Science for Life Laboratory, Department of Gene Technology, KTH Royal Institute of Technology, SE-17165 Solna, Sweden
| | - Lucas Massier
- Department of Medicine (H7), Karolinska Institutet, C2-94, Karolinska University Hospital, 141 86 Stockholm, Sweden
| | - Qian Li
- Department of Medicine (H7), Karolinska Institutet, C2-94, Karolinska University Hospital, 141 86 Stockholm, Sweden
| | - Jutta Jalkanen
- Department of Medicine (H7), Karolinska Institutet, C2-94, Karolinska University Hospital, 141 86 Stockholm, Sweden
| | - Hui Gao
- Department of Biosciences and Nutrition (H2), Karolinska Institutet, 141 86 Stockholm, Sweden
| | - Alma Andersson
- Science for Life Laboratory, Department of Gene Technology, KTH Royal Institute of Technology, SE-17165 Solna, Sweden
| | - Nayanika Bhalla
- Science for Life Laboratory, Department of Gene Technology, KTH Royal Institute of Technology, SE-17165 Solna, Sweden
| | - Anders Thorell
- Department of Clinical Sciences, Danderyd Hospital and Department of Surgery, Ersta Hospital, Karolinska Institutet, 116 91 Stockholm, Sweden
| | - Mikael Rydén
- Department of Medicine (H7), Karolinska Institutet, C2-94, Karolinska University Hospital, 141 86 Stockholm, Sweden.
| | - Patrik L Ståhl
- Science for Life Laboratory, Department of Gene Technology, KTH Royal Institute of Technology, SE-17165 Solna, Sweden.
| | - Niklas Mejhert
- Department of Medicine (H7), Karolinska Institutet, C2-94, Karolinska University Hospital, 141 86 Stockholm, Sweden.
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Zhang AM, Wellberg EA, Kopp JL, Johnson JD. Hyperinsulinemia in Obesity, Inflammation, and Cancer. Diabetes Metab J 2021; 45:285-311. [PMID: 33775061 PMCID: PMC8164941 DOI: 10.4093/dmj.2020.0250] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/23/2020] [Indexed: 12/13/2022] Open
Abstract
The relative insufficiency of insulin secretion and/or insulin action causes diabetes. However, obesity and type 2 diabetes mellitus can be associated with an absolute increase in circulating insulin, a state known as hyperinsulinemia. Studies are beginning to elucidate the cause-effect relationships between hyperinsulinemia and numerous consequences of metabolic dysfunctions. Here, we review recent evidence demonstrating that hyperinsulinemia may play a role in inflammation, aging and development of cancers. In this review, we will focus on the consequences and mechanisms of excess insulin production and action, placing recent findings that have challenged dogma in the context of the existing body of literature. Where relevant, we elaborate on the role of specific signal transduction components in the actions of insulin and consequences of chronic hyperinsulinemia. By discussing the involvement of hyperinsulinemia in various metabolic and other chronic diseases, we may identify more effective therapeutics or lifestyle interventions for preventing or treating obesity, diabetes and cancer. We also seek to identify pertinent questions that are ripe for future investigation.
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Affiliation(s)
- Anni M.Y. Zhang
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Elizabeth A. Wellberg
- Department of Pathology, University of Oklahoma Health Sciences Center, Stephenson Cancer Center, Harold Hamm Diabetes Center, Oklahoma City, OK, USA
| | - Janel L. Kopp
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - James D. Johnson
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
- Corresponding author: James D. Johnson https://orcid.org/0000-0002-7523-9433 Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, 2329 W Mall Vancouver, BC V6T 1Z4, Vancouver, BC, Canada E-mail:
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4
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Gordon-Larsen P, French JE, Moustaid-Moussa N, Voruganti VS, Mayer-Davis EJ, Bizon CA, Cheng Z, Stewart DA, Easterbrook JW, Shaikh SR. Synergizing Mouse and Human Studies to Understand the Heterogeneity of Obesity. Adv Nutr 2021; 12:2023-2034. [PMID: 33885739 PMCID: PMC8483969 DOI: 10.1093/advances/nmab040] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/17/2021] [Accepted: 03/13/2021] [Indexed: 12/12/2022] Open
Abstract
Obesity is routinely considered as a single disease state, which drives a "one-size-fits-all" approach to treatment. We recently convened the first annual University of North Carolina Interdisciplinary Nutrition Sciences Symposium to discuss the heterogeneity of obesity and the need for translational science to advance understanding of this heterogeneity. The symposium aimed to advance scientific rigor in translational studies from animal to human models with the goal of identifying underlying mechanisms and treatments. In this review, we discuss fundamental gaps in knowledge of the heterogeneity of obesity ranging from cellular to population perspectives. We also advocate approaches to overcoming limitations in the field. Examples include the use of contemporary mouse genetic reference population models such as the Collaborative Cross and Diversity Outbred mice that effectively model human genetic diversity and the use of translational models that integrate -omics and computational approaches from pre-clinical to clinical models of obesity. Finally, we suggest best scientific practices to ensure strong rigor that will allow investigators to delineate the sources of heterogeneity in the population with obesity. Collectively, we propose that it is critical to think of obesity as a heterogeneous disease with complex mechanisms and etiologies, requiring unique prevention and treatment strategies tailored to the individual.
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Affiliation(s)
| | - John E French
- Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA,Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, NC, USA
| | - Naima Moustaid-Moussa
- Obesity Research Institute and Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA
| | - Venkata S Voruganti
- Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA,Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, NC, USA
| | - Elizabeth J Mayer-Davis
- Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Christopher A Bizon
- Renaissance Computing Institute, University of North Carolina at Chapel Hill, NC, USA
| | - Zhiyong Cheng
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, USA
| | - Delisha A Stewart
- Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA,Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, NC, USA
| | - John W Easterbrook
- Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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5
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Walendzik K, Bukowska J, Kopcewicz M, Machcinska S, Gimble JM, Gawronska-Kozak B. Age, Diet and Epidermal Signaling Modulate Dermal Fibroblasts' Adipogenic Potential. Int J Mol Sci 2020; 21:ijms21238955. [PMID: 33255750 PMCID: PMC7728337 DOI: 10.3390/ijms21238955] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/16/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
The recognition of a distinct fat depot, the dermal white adipose tissue (dWAT), points out the complexity of the interaction among skin resident cells: keratinocytes, dermal fibroblasts (DFs) and adipocytes in response to physiological (diet, age) and pathological (injury) stimulations. dWAT has been recognized as a significant contributor to thermoregulation, hair cycle, immune response, wound healing and scarring. In this study, we examined age- and diet-related changes in dWAT modulation and DFs' adipogenic potential. The data showed that diet modulates dWAT expansion predominantly by hypertrophy, whereas age affects the pool of adipocyte progenitor cells in the skin indicating its role in dWAT hyperplasia. Analysis of DFs' migratory abilities in the model of skin explants isolated from the skin of young, old, low (LFD)- or high (HFD)-fat diet C56BL/6 mice revealed that HFD, regardless of animal age has the most profound stimulatory impact of DF migration. We determined that the adipogenic potential of DFs is comparable to stromal vascular fraction (SVF) of inguinal fat depot and ear mesenchymal stem cells (EMSC). We also showed the stimulatory role of epidermally expressed transcription factor Foxn1 on adipogenic signaling: bone morphogenetic protein 2 (Bmp2) and insulin-like growth factor 2 (Igf2) in keratinocytes.
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Affiliation(s)
- Katarzyna Walendzik
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
| | - Joanna Bukowska
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
| | - Marta Kopcewicz
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
| | - Sylwia Machcinska
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
| | - Jeffrey M. Gimble
- LaCell LLC, New Orleans, LA 70112, USA;
- Obatala Sciences Inc., 2000 Lakeshore Drive, #4020, New Orleans, LA 70148, USA
- Departments of Medicine, Structural and Cellular Biology, and Surgery and Center for Stem Cell Research and Regenerative Medicine, Tulane University School of Medicine, New Orleans, LA 70118, USA
| | - Barbara Gawronska-Kozak
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland; (K.W.); (J.B.); (M.K.); (S.M.)
- Correspondence: ; Tel.: +48-89-5234634; Fax: +48-89-5240124
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6
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Paszkiewicz RL, Bergman RN, Santos RS, Frank AP, Woolcott OO, Iyer MS, Stefanovski D, Clegg DJ, Kabir M. A Peripheral CB1R Antagonist Increases Lipolysis, Oxygen Consumption Rate, and Markers of Beiging in 3T3-L1 Adipocytes Similar to RIM, Suggesting that Central Effects Can Be Avoided. Int J Mol Sci 2020; 21:E6639. [PMID: 32927872 PMCID: PMC7554772 DOI: 10.3390/ijms21186639] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 09/03/2020] [Accepted: 09/08/2020] [Indexed: 02/07/2023] Open
Abstract
With the increased prevalence of obesity and related co-morbidities, such as type 2 diabetes (T2D), worldwide, improvements in pharmacological treatments are necessary. The brain- and peripheral-cannabinoid receptor 1 (CB1R) antagonist rimonabant (RIM) has been shown to induce weight loss and improve glucose homeostasis. We have previously demonstrated that RIM promotes adipose tissue beiging and decreased adipocyte cell size, even during maintenance on a high-fat diet. Given the adverse side-effects of brain-penetrance with RIM, in this study we aimed to determine the site of action for a non-brain-penetrating CB1R antagonist AM6545. By using in vitro assays, we demonstrated the direct effects of this non-brain-penetrating CB1R antagonist on cultured adipocytes. Specifically, we showed, for the first time, that AM6545 significantly increases markers of adipose tissue beiging, mitochondrial biogenesis, and lipolysis in 3T3-L1 adipocytes. In addition, the oxygen consumption rate (OCR), consisting of baseline respiratory rate, proton leak, maximal respiratory capacity, and ATP synthase activity, was greater for cells exposed to AM6545, demonstrating greater mitochondrial uncoupling. Using a lipolysis inhibitor during real-time OCR measurements, we determined that the impact of CB1R antagonism on adipocytes is driven by increased lipolysis. Thus, our data suggest the direct role of CB1R antagonism on adipocytes does not require brain penetrance, supporting the importance of focus on peripheral CB1R antagonism pharmacology for reducing the incidence of obesity and T2D.
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Affiliation(s)
- Rebecca L. Paszkiewicz
- Sports Spectacular Diabetes and Obesity Wellness and Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.L.P.); (R.N.B.); (R.S.S.); (A.P.F.); (O.O.W.); (M.S.I.)
| | - Richard N. Bergman
- Sports Spectacular Diabetes and Obesity Wellness and Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.L.P.); (R.N.B.); (R.S.S.); (A.P.F.); (O.O.W.); (M.S.I.)
| | - Roberta S. Santos
- Sports Spectacular Diabetes and Obesity Wellness and Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.L.P.); (R.N.B.); (R.S.S.); (A.P.F.); (O.O.W.); (M.S.I.)
| | - Aaron P. Frank
- Sports Spectacular Diabetes and Obesity Wellness and Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.L.P.); (R.N.B.); (R.S.S.); (A.P.F.); (O.O.W.); (M.S.I.)
| | - Orison O. Woolcott
- Sports Spectacular Diabetes and Obesity Wellness and Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.L.P.); (R.N.B.); (R.S.S.); (A.P.F.); (O.O.W.); (M.S.I.)
| | - Malini S. Iyer
- Sports Spectacular Diabetes and Obesity Wellness and Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.L.P.); (R.N.B.); (R.S.S.); (A.P.F.); (O.O.W.); (M.S.I.)
| | - Darko Stefanovski
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA;
| | - Deborah J. Clegg
- The College of Nursing and Health Professions, Drexel University, Philadelphia, PA 19104, USA;
| | - Morvarid Kabir
- Sports Spectacular Diabetes and Obesity Wellness and Research Center, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.L.P.); (R.N.B.); (R.S.S.); (A.P.F.); (O.O.W.); (M.S.I.)
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7
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Grewal T, Enrich C, Rentero C, Buechler C. Annexins in Adipose Tissue: Novel Players in Obesity. Int J Mol Sci 2019; 20:ijms20143449. [PMID: 31337068 PMCID: PMC6678658 DOI: 10.3390/ijms20143449] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 12/12/2022] Open
Abstract
Obesity and the associated comorbidities are a growing health threat worldwide. Adipose tissue dysfunction, impaired adipokine activity, and inflammation are central to metabolic diseases related to obesity. In particular, the excess storage of lipids in adipose tissues disturbs cellular homeostasis. Amongst others, organelle function and cell signaling, often related to the altered composition of specialized membrane microdomains (lipid rafts), are affected. Within this context, the conserved family of annexins are well known to associate with membranes in a calcium (Ca2+)- and phospholipid-dependent manner in order to regulate membrane-related events, such as trafficking in endo- and exocytosis and membrane microdomain organization. These multiple activities of annexins are facilitated through their diverse interactions with a plethora of lipids and proteins, often in different cellular locations and with consequences for the activity of receptors, transporters, metabolic enzymes, and signaling complexes. While increasing evidence points at the function of annexins in lipid homeostasis and cell metabolism in various cells and organs, their role in adipose tissue, obesity and related metabolic diseases is still not well understood. Annexin A1 (AnxA1) is a potent pro-resolving mediator affecting the regulation of body weight and metabolic health. Relevant for glucose metabolism and fatty acid uptake in adipose tissue, several studies suggest AnxA2 to contribute to coordinate glucose transporter type 4 (GLUT4) translocation and to associate with the fatty acid transporter CD36. On the other hand, AnxA6 has been linked to the control of adipocyte lipolysis and adiponectin release. In addition, several other annexins are expressed in fat tissues, yet their roles in adipocytes are less well examined. The current review article summarizes studies on the expression of annexins in adipocytes and in obesity. Research efforts investigating the potential role of annexins in fat tissue relevant to health and metabolic disease are discussed.
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Affiliation(s)
- Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia
| | - Carlos Enrich
- Department of Biomedicine, Unit of Cell Biology, Faculty of Medicine and Health Sciences, University of Barcelona, 08036 Barcelona, Spain
- Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Carles Rentero
- Department of Biomedicine, Unit of Cell Biology, Faculty of Medicine and Health Sciences, University of Barcelona, 08036 Barcelona, Spain
- Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Christa Buechler
- Department of Internal Medicine I, Regensburg University Hospital, 93053 Regensburg, Germany.
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8
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Yang H, Ralle M, Wolfgang MJ, Dhawan N, Burkhead JL, Rodriguez S, Kaplan JH, Wong GW, Haughey N, Lutsenko S. Copper-dependent amino oxidase 3 governs selection of metabolic fuels in adipocytes. PLoS Biol 2018; 16:e2006519. [PMID: 30199530 PMCID: PMC6130853 DOI: 10.1371/journal.pbio.2006519] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/14/2018] [Indexed: 12/23/2022] Open
Abstract
Copper (Cu) has emerged as an important modifier of body lipid metabolism. However, how Cu contributes to the physiology of fat cells remains largely unknown. We found that adipocytes require Cu to establish a balance between main metabolic fuels. Differentiating adipocytes increase their Cu uptake along with the ATP7A-dependent transport of Cu into the secretory pathway to activate a highly up-regulated amino-oxidase copper-containing 3 (AOC3)/semicarbazide-sensitive amine oxidase (SSAO); in vivo, the activity of SSAO depends on the organism's Cu status. Activated SSAO oppositely regulates uptake of glucose and long-chain fatty acids and remodels the cellular proteome to coordinate changes in fuel availability and related downstream processes, such as glycolysis, de novo lipogenesis, and sphingomyelin/ceramide synthesis. The loss of SSAO-dependent regulation due to Cu deficiency, limited Cu transport to the secretory pathway, or SSAO inactivation shifts metabolism towards lipid-dependent pathways and results in adipocyte hypertrophy and fat accumulation. The results establish a role for Cu homeostasis in adipocyte metabolism and identify SSAO as a regulator of energy utilization processes in adipocytes.
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Affiliation(s)
- Haojun Yang
- Department of Physiology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Martina Ralle
- Department of Genetics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Michael J. Wolfgang
- Center for Metabolism and Obesity Research, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Neha Dhawan
- Department of Physiology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jason L. Burkhead
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, Alaska, United States of America
| | - Susana Rodriguez
- Department of Physiology, Johns Hopkins University, Baltimore, Maryland, United States of America
- Center for Metabolism and Obesity Research, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jack H. Kaplan
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - G. William Wong
- Department of Physiology, Johns Hopkins University, Baltimore, Maryland, United States of America
- Center for Metabolism and Obesity Research, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Norman Haughey
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Svetlana Lutsenko
- Department of Physiology, Johns Hopkins University, Baltimore, Maryland, United States of America
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9
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Pedro MN, Rocha GZ, Guadagnini D, Santos A, Magro DO, Assalin HB, Oliveira AG, Pedro RDJ, Saad MJA. Insulin Resistance in HIV-Patients: Causes and Consequences. Front Endocrinol (Lausanne) 2018; 9:514. [PMID: 30233499 PMCID: PMC6133958 DOI: 10.3389/fendo.2018.00514] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 08/16/2018] [Indexed: 12/14/2022] Open
Abstract
Here we review how immune activation and insulin resistance contribute to the metabolic alterations observed in HIV-infected patients, and how these alterations increase the risk of developing CVD. The introduction and evolution of antiretroviral drugs over the past 25 years has completely changed the clinical prognosis of HIV-infected patients. The deaths of these individuals are now related to atherosclerotic CVDs, rather than from the viral infection itself. However, HIV infection, cART, and intestinal microbiota are associated with immune activation and insulin resistance, which can lead to the development of a variety of diseases and disorders, especially with regards to CVDs. The increase in LPS and proinflammatory cytokines circulating levels and intracellular mechanisms activate serine kinases, resulting in insulin receptor substrate-1 (IRS-1) serine phosphorylation and consequently a down regulation in insulin signaling. While lifestyle modifications and pharmaceutical interventions can be employed to treat these altered metabolic functions, the mechanisms involved in the development of these chronic complications remain largely unresolved. The elucidation and understanding of these mechanisms will give rise to new classes of drugs that will further improve the quality of life of HIV-infected patients, over the age of 50.
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Affiliation(s)
- Marcelo N. Pedro
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
| | - Guilherme Z. Rocha
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
| | - Dioze Guadagnini
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
| | - Andrey Santos
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
| | - Daniela O. Magro
- Department of Surgery, Faculty of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
| | - Heloisa B. Assalin
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
| | - Alexandre G. Oliveira
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
- Biosciences Institute, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Rogerio de Jesus Pedro
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
| | - Mario J. A. Saad
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas-UNICAMP, Campinas, Brazil
- *Correspondence: Mario J. A. Saad
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10
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Al-Qahtani SM, Bryzgalova G, Valladolid-Acebes I, Korach-André M, Dahlman-Wright K, Efendić S, Berggren PO, Portwood N. 17β-Estradiol suppresses visceral adipogenesis and activates brown adipose tissue-specific gene expression. Horm Mol Biol Clin Investig 2017; 29:13-26. [PMID: 27831918 DOI: 10.1515/hmbci-2016-0031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 09/30/2016] [Indexed: 11/15/2022]
Abstract
Both functional ovaries and estrogen replacement therapy (ERT) reduce the risk of type 2 diabetes (T2D). Understanding the mechanisms underlying the antidiabetic effects of 17β-estradiol (E2) may permit the development of a molecular targeting strategy for the treatment of metabolic disease. This study examines how the promotion of insulin sensitivity and weight loss by E2 treatment in high-fat-diet (HFD)-fed mice involve several anti-adipogenic processes in the visceral adipose tissue. Magnetic resonance imaging (MRI) revealed specific reductions in visceral adipose tissue volume in HFD+E2 mice, compared with HFD mice. This loss of adiposity was associated with diminished visceral adipocyte size and reductions in expression of lipogenic genes, adipokines and of the nuclear receptor nr2c2/tr4. Meanwhile, expression levels of adipose triglyceride lipase/pnpla2 and leptin receptor were increased. As mRNA levels of stat3, a transcription factor involved in brown adipose tissue differentiation, were also increased in visceral adipose, the expression of other brown adipose-specific markers was assessed. Both expression and immunohistochemical staining of ucp-1 were increased, and mRNA levels of dio-2, and of adrβ3, a regulator of ucp-1 expression during the thermogenic response, were increased. Furthermore, expression of cpt-1b, a brown adipose-specific gene involved in fatty acid utilization, was also increased. Methylation studies demonstrated that the methylation status of both dio-2 and adrβ3 was significantly reduced. These results show that improved glycemic control and weight loss due to E2 involve anti-adipogenic mechanisms which include suppressed lipogenesis and augmented fatty acid utilization, and in addition, the activation of brown adipose tissue-specific gene expression in association with E2-dependent epigenetic modifications in these genes.
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11
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Vetterli L, Carobbio S, Frigerio F, Karaca M, Maechler P. The Amplifying Pathway of the β-Cell Contributes to Diet-induced Obesity. J Biol Chem 2016; 291:13063-75. [PMID: 27137930 DOI: 10.1074/jbc.m115.707448] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Indexed: 12/24/2022] Open
Abstract
Efficient energy storage in adipose tissues requires optimal function of the insulin-producing β-cell, whereas its dysfunction promotes diabetes. The associated paradox related to β-cell efficiency is that excessive accumulation of fat in adipose tissue predisposes for type 2 diabetes. Insulin exocytosis is regulated by intracellular metabolic signal transduction, with glutamate dehydrogenase playing a key role in the amplification of the secretory response. Here, we used mice with β-cell-selective glutamate dehydrogenase deletion (βGlud1(-/-)), lacking an amplifying pathway of insulin secretion. As opposed to control mice, βGlud1(-/-) animals fed a high calorie diet maintained glucose tolerance and did not develop diet-induced obesity. Islets of βGlud1(-/-) mice did not increase their secretory response upon high calorie feeding, as did islets of control mice. Inhibited adipose tissue expansion observed in knock-out mice correlated with lower expression of genes responsible for adipogenesis. Rather than being efficiently stored, lipids were consumed at a higher rate in βGlud1(-/-) mice compared with controls, in particular during food intake periods. These results show that reduced β-cell function prior to high calorie feeding prevented diet-induced obesity.
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Affiliation(s)
- Laurène Vetterli
- From the Department of Cell Physiology and Metabolism and Faculty Diabetes Center, Geneva University Medical Centre, 1211 Geneva 4, Switzerland
| | - Stefania Carobbio
- From the Department of Cell Physiology and Metabolism and Faculty Diabetes Center, Geneva University Medical Centre, 1211 Geneva 4, Switzerland
| | - Francesca Frigerio
- From the Department of Cell Physiology and Metabolism and Faculty Diabetes Center, Geneva University Medical Centre, 1211 Geneva 4, Switzerland
| | - Melis Karaca
- From the Department of Cell Physiology and Metabolism and Faculty Diabetes Center, Geneva University Medical Centre, 1211 Geneva 4, Switzerland
| | - Pierre Maechler
- From the Department of Cell Physiology and Metabolism and Faculty Diabetes Center, Geneva University Medical Centre, 1211 Geneva 4, Switzerland
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12
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Lee JJ, Pedley A, Hoffmann U, Massaro JM, Keaney JF, Vasan RS, Fox CS. Cross-Sectional Associations of Computed Tomography (CT)-Derived Adipose Tissue Density and Adipokines: The Framingham Heart Study. J Am Heart Assoc 2016; 5:e002545. [PMID: 26927600 PMCID: PMC4943240 DOI: 10.1161/jaha.115.002545] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background Excess accumulation of abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) is associated with adverse levels of adipokines and cardiovascular disease risk. Whether fat quality is associated with adipokines has not been firmly established. This study examined the association between abdominal SAT and VAT density, an indirect measure of fat quality, with a panel of metabolic regulatory biomarkers secreted by adipose tissue or the liver independently of absolute fat volumes. Methods and Results We evaluated 1829 Framingham Heart Study participants (44.9% women). Abdominal SAT and VAT density was estimated indirectly by adipose tissue attenuation using computed tomography. Adipokines included adiponectin, leptin receptor, leptin, fatty acid‐binding protein 4 (FABP‐4), retinol‐binding protein 4 (RBP‐4), and fetuin‐A. Fat density was associated with all the biomarkers evaluated, except fetuin‐A. Lower fat density (ie, more‐negative fat attenuation) was associated with lower adiponectin and leptin receptor, but higher leptin and FABP‐4 levels (all P<0.0001). SAT density was inversely associated with RPB‐4 in both sexes, whereas the association between VAT density and RPB‐4 was only observed in men (P<0.0001). In women, after additional adjustment for respective fat volume, SAT density retained the significant associations with adiponectin, leptin, FABP‐4, and RBP‐4; and VAT density with adiponectin only (all P<0.0001). In men, significant associations were maintained upon additional adjustment for respective fat volume (P<0.005). Conclusions Lower abdominal fat density was associated with a profile of biomarkers suggestive of greater cardiometabolic risk. These observations support that fat density may be a valid biomarker of cardiometabolic risk.
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Affiliation(s)
- Jane J Lee
- National Heart, Lung, and Blood Institute's Division of Intramural Research, The Framingham Heart Study, and the Population Studies Branch, Framingham, MA
| | - Alison Pedley
- National Heart, Lung, and Blood Institute's Division of Intramural Research, The Framingham Heart Study, and the Population Studies Branch, Framingham, MA
| | - Udo Hoffmann
- Department of Radiology, Massachusetts General Hospital, Boston, MA
| | | | - John F Keaney
- Division of Cardiovascular Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Ramachandran S Vasan
- National Heart, Lung, and Blood Institute's Division of Intramural Research, The Framingham Heart Study, and the Population Studies Branch, Framingham, MA Evans Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA Sections of Cardiology and Preventive Medicine, Boston University School of Medicine, Boston, MA Department of Epidemiology, Boston University School of Public Health, Boston, MA
| | - Caroline S Fox
- National Heart, Lung, and Blood Institute's Division of Intramural Research, The Framingham Heart Study, and the Population Studies Branch, Framingham, MA Division of Endocrinology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
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13
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Abstract
Obesity has emerged as one of the major global epidemics of the 21st century and is now reaching alarming proportions. Obese subjects have an increased morbidity and mortality, decreased quality of life and a major risk of developing pathologies such as diabetes mellitus, insulin resistance and cardiovascular disease. Obesity is a complex disease characterised by an increase in body fat mass resulting from an imbalance between energy intake and expenditure. Signal integration between adipose tissue, other peripheral organs and the CNS seems to regulate energy homeostasis. Proteomics may be useful in unravelling the pathogenesis of obesity, since a combination of genetic predisposition and environmental factors account for its development. Most of the proteomic studies performed to date have focused on protein profiling of adipose tissue in different models of experimental obesity and the study of the adipocyte differentiation process. Another issue that has recently attracted attention is the characterisation of the adipocyte secretome, which may be important in signalling to other organs and in regulating energy balance. Target identification of potential therapies has also been investigated by proteomics. This review focuses on the contributions of proteomics to understanding the molecular mechanisms of obesity and their potential therapies.
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Affiliation(s)
| | - Ramon Gomis
- Diabetes and Obesity Laboratory-Endocrinology and Nutrition Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)-Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
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14
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Chang GR, Chiu YS, Wu YY, Lin YC, Hou PH, Mao FC. Rapamycin impairs HPD-induced beneficial effects on glucose homeostasis. Br J Pharmacol 2015; 172:3793-804. [PMID: 25884889 PMCID: PMC4523336 DOI: 10.1111/bph.13168] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 03/08/2015] [Accepted: 04/07/2015] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE Rapamycin, which is used clinically to treat graft rejection, has also been proposed to have an effect on metabolic syndrome; however, very little information is available on its effects in lean animals/humans. The purpose of this study was to characterize further the effects of the continuous use of rapamycin on glucose homeostasis in lean C57BL6/J mice. EXPERIMENTAL APPROACH Mice were fed a high-protein diet (HPD) for 12 weeks to develop a lean model and then were treated daily with rapamycin for 5 weeks while remaining on a HPD. Metabolic parameters, endocrine profiles, glucose tolerance tests, insulin sensitivity index, the expression of the glucose transporter GLUT4 and chromium distribution were measured in vivo. KEY RESULTS Lower body weight gain as well as a decreased caloric intake, fat pads, fatty liver scores, adipocyte size and glucose tolerance test values were observed in HPD-fed mice compared with mice fed a high-fat or standard diet. Despite these beneficial effects, rapamycin-treated lean mice showed greater glucose intolerance, reduced insulin sensitivity, lower muscle GLUT4 expression and changes in chromium levels in tissues even with high insulin levels. CONCLUSION AND IMPLICATIONS Our findings demonstrate that continuous rapamycin administration may lead to the development of diabetes syndrome, as it was found to induce hyperglycaemia and glucose intolerance in a lean animal model.
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Affiliation(s)
- Geng-Ruei Chang
- Department of Veterinary Medicine, National Chung Hsing UniversityTaichung, Taiwan
- Division of Residual Control, Agricultural Chemicals and Toxic Substance Research Institute, Council of AgricultureTaichung, Taiwan
| | - Yi-Shin Chiu
- Department of Veterinary Medicine, National Chung Hsing UniversityTaichung, Taiwan
| | - Ying-Ying Wu
- Department of Veterinary Medicine, National Chung Hsing UniversityTaichung, Taiwan
| | - Yu-Chi Lin
- Department of Veterinary Medicine, National Chung Hsing UniversityTaichung, Taiwan
| | - Po-Hsun Hou
- Department of Veterinary Medicine, National Chung Hsing UniversityTaichung, Taiwan
- Department of Psychiatry, Taichung Veterans General HospitalTaichung, Taiwan
| | - Frank Chiahung Mao
- Department of Veterinary Medicine, National Chung Hsing UniversityTaichung, Taiwan
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15
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Palominos MM, Dünner NH, Wabitsch M, Rojas CV. Angiotensin II directly impairs adipogenic differentiation of human preadipose cells. Mol Cell Biochem 2015; 408:115-22. [PMID: 26112903 DOI: 10.1007/s11010-015-2487-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 06/18/2015] [Indexed: 01/20/2023]
Abstract
Angiotensin II reduces adipogenic differentiation of preadipose cells present in the stroma-vascular fraction of human adipose tissue, which also includes several cell types. Because of the ability of non-adipose lineage cells in the stroma-vascular fraction to respond to angiotensin II, it is not possible to unequivocally ascribe the anti-adipogenic response to a direct effect of this hormone on preadipose cells. Therefore, we used the human Simpson-Golabi-Behmel syndrome (SGBS) preadipocyte cell strain to investigate the consequences of angiotensin II treatment on adipogenic differentiation under serum-free conditions, by assessing expression of typical adipocyte markers perilipin and fatty acid-binding protein 4 (FABP4), at the transcript and protein level. Reverse transcription-polymerase chain reaction showed that perilipin and FABP4 transcripts were, respectively, reduced to 0.33 ± 0.07 (P < 0.05) and 0.41 ± 0.19-fold (P < 0.05) in SGBS cells induced to adipogenic differentiation in the presence of angiotensin II. Western Blot analysis corroborated reduction of the corresponding proteins to 0.23 ± 0.21 (P < 0.01) and 0.46 ± 0.30-fold (P < 0.01) the respective controls without angiotensin II. Angiotensin II also impaired morphological changes associated with early adipogenesis. Hence, we demonstrated that angiotensin II is able to directly reduce adipogenic differentiation of SGBS preadipose cells.
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Affiliation(s)
- Marisol M Palominos
- Faculty of Medicine, Institute of Biomedical Sciences, Universidad de Chile, Clasificador 7 Correo 7, Santiago, Chile
| | - Natalia H Dünner
- Faculty of Medicine, Institute of Biomedical Sciences, Universidad de Chile, Clasificador 7 Correo 7, Santiago, Chile
| | - Martin Wabitsch
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, University Medical Center Ulm, Ulm, Germany
| | - Cecilia V Rojas
- Faculty of Medicine, Institute of Biomedical Sciences, Universidad de Chile, Clasificador 7 Correo 7, Santiago, Chile. .,Institute of Nutrition and Food Technology, Universidad de Chile, Casilla, 138-11, Santiago, Chile.
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16
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Mesnier A, Champion S, Louis L, Sauzet C, May P, Portugal H, Benbrahim K, Abraldes J, Alessi MC, Amiot-Carlin MJ, Peiretti F, Piccerelle P, Nalbone G, Villard PH. The Transcriptional Effects of PCB118 and PCB153 on the Liver, Adipose Tissue, Muscle and Colon of Mice: Highlighting of Glut4 and Lipin1 as Main Target Genes for PCB Induced Metabolic Disorders. PLoS One 2015; 10:e0128847. [PMID: 26086818 PMCID: PMC4473719 DOI: 10.1371/journal.pone.0128847] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/30/2015] [Indexed: 12/21/2022] Open
Abstract
Epidemiological studies have associated environmental exposure to polychlorinated biphenyls (PCBs) with an increased risk of type 2 diabetes; however, little is known about the underlying mechanisms involved in the metabolic side-effects of PCB. Our study evaluated the transcriptional effects of a subchronic exposure (gavage at Day 0 and Day 15 with 10 or 100 μmol/Kg bw) to PCB118 (dioxin-like PCB), PCB153 (non-dioxin-like PCB), or an equimolar mixture of PCB118 and PCB153 on various tissues (liver, visceral adipose tissue, muscle, and colon) in mice. Our results showed that a short-term exposure to PCB118 and/or PCB153 enhanced circulating triglyceride levels but did not affect glycemia. Among the studied tissues, we did not observe any modification of the expression of inflammation-related genes, such as cytokines or chemokines. The main transcriptional effects were observed in visceral adipose and liver tissues. We found a downregulation of lipin1 and glut4 expression in these two target organs. In adipose tissue, we also showed a downregulation of Agpat2, Slc25a1, and Fasn. All of these genes are involved in lipid metabolism and insulin resistance. In muscles, we observed an induction of CnR1 and Foxo3 expression, which may be partly involved in PCB metabolic effects. In summary, our results suggest that lipin1 and glut4, notably in adipose tissue, are the main targeted genes in PCB-induced metabolic disorders, however, further studies are required to fully elucidate the mechanisms involved.
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Affiliation(s)
- Aurélia Mesnier
- IMBE (Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale), UMR CNRS 7263, IRD 237 Aix-Marseille Université Avignon Université, Campus Timone, Faculté de Pharmacie, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Serge Champion
- IMBE (Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale), UMR CNRS 7263, IRD 237 Aix-Marseille Université Avignon Université, Campus Timone, Faculté de Pharmacie, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Laurence Louis
- UMR S 910 Génétique Médicale et Génomique Fonctionnelle, Campus Timone, Faculté de Médecine, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Christophe Sauzet
- IMBE (Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale), UMR CNRS 7263, IRD 237 Aix-Marseille Université Avignon Université, Campus Timone, Faculté de Pharmacie, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Phealay May
- IMBE (Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale), UMR CNRS 7263, IRD 237 Aix-Marseille Université Avignon Université, Campus Timone, Faculté de Pharmacie, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Henri Portugal
- UMR INSERM 1062, INRA 1260, Nutrition, Obésité et Risque Thrombotique (NORT), Aix-Marseille Université Campus Timone, Faculté de Médecine, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Karim Benbrahim
- IMBE (Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale), UMR CNRS 7263, IRD 237 Aix-Marseille Université Avignon Université, Campus Timone, Faculté de Pharmacie, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Joelle Abraldes
- IMBE (Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale), UMR CNRS 7263, IRD 237 Aix-Marseille Université Avignon Université, Campus Timone, Faculté de Pharmacie, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Marie-Christine Alessi
- UMR INSERM 1062, INRA 1260, Nutrition, Obésité et Risque Thrombotique (NORT), Aix-Marseille Université Campus Timone, Faculté de Médecine, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Marie-Josephe Amiot-Carlin
- UMR INSERM 1062, INRA 1260, Nutrition, Obésité et Risque Thrombotique (NORT), Aix-Marseille Université Campus Timone, Faculté de Médecine, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Franck Peiretti
- UMR INSERM 1062, INRA 1260, Nutrition, Obésité et Risque Thrombotique (NORT), Aix-Marseille Université Campus Timone, Faculté de Médecine, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Philippe Piccerelle
- IMBE (Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale), UMR CNRS 7263, IRD 237 Aix-Marseille Université Avignon Université, Campus Timone, Faculté de Pharmacie, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Gilles Nalbone
- UMR INSERM 1062, INRA 1260, Nutrition, Obésité et Risque Thrombotique (NORT), Aix-Marseille Université Campus Timone, Faculté de Médecine, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
| | - Pierre-Henri Villard
- IMBE (Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale), UMR CNRS 7263, IRD 237 Aix-Marseille Université Avignon Université, Campus Timone, Faculté de Pharmacie, 27 Boulevard Jean Moulin, F-13385, Marseille cedex 05, France
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17
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Lipid-overloaded enlarged adipocytes provoke insulin resistance independent of inflammation. Mol Cell Biol 2015; 35:1686-99. [PMID: 25733684 DOI: 10.1128/mcb.01321-14] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 02/24/2015] [Indexed: 02/06/2023] Open
Abstract
In obesity, adipocyte hypertrophy and proinflammatory responses are closely associated with the development of insulin resistance in adipose tissue. However, it is largely unknown whether adipocyte hypertrophy per se might be sufficient to provoke insulin resistance in obese adipose tissue. Here, we demonstrate that lipid-overloaded hypertrophic adipocytes are insulin resistant independent of adipocyte inflammation. Treatment with saturated or monounsaturated fatty acids resulted in adipocyte hypertrophy, but proinflammatory responses were observed only in adipocytes treated with saturated fatty acids. Regardless of adipocyte inflammation, hypertrophic adipocytes with large and unilocular lipid droplets exhibited impaired insulin-dependent glucose uptake, associated with defects in GLUT4 trafficking to the plasma membrane. Moreover, Toll-like receptor 4 mutant mice (C3H/HeJ) with high-fat-diet-induced obesity were not protected against insulin resistance, although they were resistant to adipose tissue inflammation. Together, our in vitro and in vivo data suggest that adipocyte hypertrophy alone may be crucial in causing insulin resistance in obesity.
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18
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Abstract
Obesity is frequently associated with chronic inflammation, metabolic and vascular alterations which predispose to the development of the Metabolic Syndrome (MetS). However, the individual obesity-related risk for the MetS is not determined by increased fat mass alone. Heterogeneity of body composition, fat distribution and adipose tissue (AT) function may underly the variable risk to develop metabolic and cardiovascular diseases associated with increased body fat mass. Importantly, an inability to increase AT mass by adipocyte hyperplasia may lead to adipocyte hypertrophy and could induce dysfunction of adipose tissue characterized by decreased insulin sensitivity, hypoxia, increased parameters of intracellular stress, increased autophagy and apoptosis and tissue inflammation. As a result, adipocytes and other AT cells release signals (e.g. adipokines, cells, metabolites) resulting in a proinflammatory, diabetogenic and atherogenic serum profile. These adverse signals may contribute to further AT inflammation and secondary organ damage in target tissues such as liver, brain, endothelium, vasculature, endocrine organs and skeletal muscle. Recently, a specific adipocyte volume threshold has been shown to predict the risk for obesity-associated type 2 diabetes. Most likely, impaired adipocyte function is caused by genetic, behavioural and environmental factors which are not entirely understood. Elucidating the mechanisms of adipocyte dysfunction may lead to the identification of novel treatment targets for obesity and the MetS.
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Affiliation(s)
- Nora Klöting
- Department of Medicine, University of Leipzig, Liebigstr. 20, 04103, Leipzig, Germany
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19
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Mansouri M, Nikooie R, Keshtkar A, Larijani B, Omidfar K. Effect of endurance training on retinol-binding protein 4 gene expression and its protein level in adipose tissue and the liver in diabetic rats induced by a high-fat diet and streptozotocin. J Diabetes Investig 2014; 5:484-91. [PMID: 25411614 PMCID: PMC4188104 DOI: 10.1111/jdi.12186] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Revised: 10/21/2013] [Accepted: 10/22/2013] [Indexed: 01/17/2023] Open
Abstract
AIMS/INTRODUCTION The present study was designed to investigate from which tissues the decrease in retinol-binding protein 4 (RBP4) expression could contribute to the improvement of serum RBP4 and insulin resistance (IR) after endurance training. MATERIALS AND METHODS Male 7-week-old Wistar rats were randomly assigned into four groups including control (C), trained (T), diabetic control (DC) and trained diabetic (TD). At 8 weeks-of-age, diabetes was induced by a high-fat diet and intraperitoneal injection of low-dose streptozotocin (STZ; 35 mg/kg). Rats in the T and TD groups carried out a 7-week exercise program on a motorized treadmill (15-20 m/min for 20 min/day for 5 weeks), whereas the C and DC remained sedentary in their cages. Tissues gene expression and protein levels of RBP4 were assessed by using real-time polymerase chain reaction and western blot, respectively, while serum RBP4 was measured using an enzyme-linked immunosorbent assay kit. RESULTS Exercise significantly improved IR and reduced serum concentration of RBP4 in the TD group. This reduction of serum RBP4 was accompanied by decreased RBP4 protein expression in visceral fat tissue. In contrast, exercise had no significant effect on RBP4 expression in liver and subcutaneous fat tissue in the TD group. Exercise also significantly decreased RBP4 gene expression in visceral fat tissue and muscle, whereas the effect of exercise on liver RBP4 messenger ribonucleic acid expression was not significant. CONCLUSIONS The present study showed that the mechanism for RBP4 reducing the effect of endurance training could involve decreased RBP4 messenger ribonucleic acid expression and its protein level in adipose tissue in STZ-induced diabetic rats.
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Affiliation(s)
- Masoume Mansouri
- Obesity and Eating Habits Research CenterEndocrinology and Metabolism Molecular‐Cellular Sciences InstituteTehranIran
- Endocrinology and Metabolism Research CenterEndocrinology and Metabolism Research InstituteTehran University of Medical SciencesTehranIran
| | - Rohollah Nikooie
- Department of Exercise PhysiologyFaculty of Physical Education and Sport ScienceShahid Bahonar UniversityKermanIran
| | - Abasali Keshtkar
- Osteoprosis Research CenterEndocrinology and Metabolism Research InstituteTehran University of Medical SciencesTehranIran
| | - Bagher Larijani
- Endocrinology and Metabolism Research CenterEndocrinology and Metabolism Research InstituteTehran University of Medical SciencesTehranIran
| | - Kobra Omidfar
- Biosensor Research CenterEndocrinology and Metabolism Molecular‐Cellular Sciences InstituteTehranIran
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20
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Lafontan M. Adipose tissue and adipocyte dysregulation. DIABETES & METABOLISM 2014; 40:16-28. [DOI: 10.1016/j.diabet.2013.08.002] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 08/25/2013] [Indexed: 12/19/2022]
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21
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Nagel SA, Keuper M, Zagotta I, Enlund E, Ruperez AI, Debatin KM, Wabitsch M, Fischer-Posovszky P. Up-regulation of Bcl-2 during adipogenesis mediates apoptosis resistance in human adipocytes. Mol Cell Endocrinol 2014; 382:368-376. [PMID: 24397922 DOI: 10.1016/j.mce.2013.10.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 10/16/2013] [Accepted: 10/21/2013] [Indexed: 01/05/2023]
Abstract
Targeting apoptotic pathways in adipocytes has been suggested as a pharmacological approach to treat obesity. However, adipocyte apoptosis was identified as a cause for macrophage infiltration into adipose tissue. Previous studies suggest that mature adipocytes are less sensitive to apoptotic stimuli as compared to preadipocytes. Here, we aimed to identify proteins mediating apoptosis resistance in adipocytes. Our data revealed that the anti-apoptotic protein Bcl-2 (B-cell lymphoma 2) is up-regulated during adipogenic differentiation. Bcl-2 overexpression in preadipocytes lowers their apoptosis sensitivity to the level of mature adipocytes. Vice versa Bcl-2 knockdown in adipocytes sensitizes these cells to CD95-induced apoptosis. Taken together, our findings suggest a shift in the balance of pro-apoptotic and anti-apoptotic molecules during adipogenesis resulting in a higher apoptosis resistance. This study sheds new light on the apoptotic process in human fat cells and may constitute a new possible target for the specific regulation of adipose tissue mass.
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Affiliation(s)
- Stella A Nagel
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Michaela Keuper
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Ivana Zagotta
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Eveliina Enlund
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Azahara Iris Ruperez
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Klaus-Michael Debatin
- Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany
| | - Martin Wabitsch
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany.
| | - Pamela Fischer-Posovszky
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, 89075 Ulm, Germany.
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Sajan MP, Jurzak MJ, Samuels VT, Shulman GI, Braun U, Leitges M, Farese RV. Impairment of insulin-stimulated glucose transport and ERK activation by adipocyte-specific knockout of PKC-λ produces a phenotype characterized by diminished adiposity and enhanced insulin suppression of hepatic gluconeogenesis. Adipocyte 2014; 3:19-29. [PMID: 24575365 PMCID: PMC3917928 DOI: 10.4161/adip.26305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 08/16/2013] [Accepted: 08/28/2013] [Indexed: 12/16/2022] Open
Abstract
Tissue-specific knockout (KO) of atypical protein kinase C-λ (PKC-λ) impairs insulin-stimulated glucose transport in muscle (M) and lipid synthesis in liver (L), thereby producing insulin resistance in MλKO mice and insulin-hypersensitivity in LλKO mice. Here, we generated mice with KO of PKC-λ in adipocytes, i.e., AλKO mice. In isolated adipocytes of AλKO mice, insulin-stimulated aPKC activity and glucose transport were diminished, as were ERK levels and activity. Insulin-stimulated glucose transport and insulin activation of ERK in adipocytes of wild-type mice were similarly inhibited by acute inhibition of PKC-λ with a highly-specific chemical inhibitor. With impairments in glucose transport and ERK activation, AλKO mice had diminished adiposity and serum leptin levels. In addition, AλKO mice had normal glucose tolerance and insulin hypersensitivity owing to enhanced suppression of hepatic glucose output, which apparently reflected increases in Akt activity and FoxO1 phosphorylation, and subsequent decreases in expression of gluconeogenic phosphoenolpyruvate carboxykinase. We conclude that: PKC-λ is required for insulin-stimulated glucose transport and ERK signaling in mouse adipocytes; and diminution of these processes is attended by leanness and therefore hypoleptinemia. How these and perhaps other PKC-λ-dependent processes communicate to liver and improve insulin suppression of hepatic gluconeogenesis remains unclear.
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Moest H, Frei AP, Bhattacharya I, Geiger M, Wollscheid B, Wolfrum C. Malfunctioning of adipocytes in obesity is linked to quantitative surfaceome changes. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1208-16. [PMID: 24046861 DOI: 10.1016/j.bbalip.2013.04.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Increased triglyceride accumulation in adipocytes caused by a misbalance between energy intake and energy consumption, results in increased adipocyte size, excess adipose tissue, increased body weight and ultimately, obesity. It is well established that enlarged adipocytes exhibit malfunctions that contribute to whole body insulin resistance, a key factor for the development of type 2 diabetes. However, the underlying molecular cause for dysfunctional adipocyte behavior and signaling is poorly understood. Since the adipocyte cell surface proteome, or surfaceome, represents the cellular signaling gateway to the microenvironment, we studied the contribution of this subproteome to adipocyte malfunctions in obesity. By using the chemoproteomic Cell Surface Capture (CSC) technology, we established surfaceome maps of primary adipocytes derived from different mouse models for metabolic disorders. Relative quantitative comparison between these surfaceome maps revealed a set of cell surface glycoproteins with modulated location-specific abundance levels. RNAi mediated targeting of a subset of the detected obesity modulated cell surface glycoproteins in an in vitro model system provided functional evidence for their role in adiponectin secretion and the lipolytic activity of adipocytes. Thus, we conclude that the identified cell surface glycoproteins which exhibit obesity induced abundance changes and impact adipocyte function at the same time contribute to adipocyte malfunction in obesity. The regulation of their concerted activities could improve adipocyte function in obesity.
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Affiliation(s)
- Hansjoerg Moest
- Institute of Molecular Systems Biology, ETH Zurich, Switzerland
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24
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Meyer LK, Ciaraldi TP, Henry RR, Wittgrove AC, Phillips SA. Adipose tissue depot and cell size dependency of adiponectin synthesis and secretion in human obesity. Adipocyte 2013; 2:217-26. [PMID: 24052897 PMCID: PMC3774697 DOI: 10.4161/adip.24953] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/06/2013] [Accepted: 05/06/2013] [Indexed: 01/08/2023] Open
Abstract
Adiponectin is an insulin sensitizing fat cell (FC) hormone whose levels are related to adipose tissue (AT) mass and depot distribution. We hypothesized that the nature of AT expansion (hypertrophy vs. hyperplasia) contributes to obesity-related reductions in serum adiponectin and that this effect is influenced by the regional distribution of AT to subcutaneous (S) and visceral (V) depots. Thirteen obese subjects provided paired AT biopsies. Serum total and high molecular weight (HMW) adiponectin levels were determined by ELISA. Secretion was quantified following 24-h explant culture. FC size, number, % large, and % small FC were determined by microscopic analysis. Secretion of total adiponectin was highest by SAT (P = 0.008) and correlated more strongly with serum adiponectin (total: P = 0.015, r = 0.77; HMW: P = 0.005, r = 0.83) than did secretion by VAT (P = 0.05, r = 0.66 for both). FC size was greatest in SAT and correlated negatively with both serum (total: P = 0.01, r = −0.74; HMW: P = 0.03, r = −0.69) and secreted (total: P = 0.05, r = −0.72; HMW: P = 0.02, r = −0.87) adiponectin. The % small FC in SAT correlated positively with both serum (total: P = 0.006, r = 0.87; HMW: P = 0.009, r = 0.79) and secreted (total: P = 0.03, r = 0.75; HMW: P = 0.01, r = 0.92) adiponectin. VAT FC size correlated negatively with serum HMW adiponectin (P = 0.01, r = −0.76) but not with any measure of secretion. VAT had the greatest % small FC, which related positively to serum HMW (P = 0.004, r = 0.81) and to secreted total adiponectin (P = 0.02, r = 0.78). These studies indicate that differences in fat cell size and depot distribution of AT expansion are important influences on adiponectin in obesity.
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25
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Lim D, Gondro C, Park HS, Cho YM, Chai HH, Seong HH, Yang BS, Hong SK, Chang WK, Lee SH. Identification of recently selected mutations driven by artificial selection in hanwoo (korean cattle). ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2013; 26:603-8. [PMID: 25049829 PMCID: PMC4093327 DOI: 10.5713/ajas.2012.12456] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 12/01/2012] [Accepted: 10/24/2012] [Indexed: 01/31/2023]
Abstract
Hanwoo have been subjected over the last seventy years to intensive artificial selection with the aim of improving meat production traits such as marbling and carcass weight. In this study, we performed a signature of selection analysis to identify recent positive selected regions driven by a long-term artificial selection process called a breeding program using whole genome SNP data. In order to investigate homozygous regions across the genome, we estimated iES (integrated Extended Haplotype Homozygosity SNP) for the each SNPs. As a result, we identified two highly homozygous regions that seem to be strong and/or recent positive selection. Five genes (DPH5, OLFM3, S1PR1, LRRN1 and CRBN) were included in this region. To go further in the interpretation of the observed signatures of selection, we subsequently concentrated on the annotation of differentiated genes defined according to the iES value of SNPs localized close or within them. We also described the detection of the adaptive evolution at the molecular level for the genes of interest. As a result, this analysis also led to the identification of OLFM3 as having a strong signal of selection in bovine lineage. The results of this study indicate that artificial selection which might have targeted most of these genes was mainly oriented towards improvement of meat production.
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Affiliation(s)
- Dajeong Lim
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Suwon 441-706, Korea
| | - Cedric Gondro
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - Hye Sun Park
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Suwon 441-706, Korea
| | - Yong Min Cho
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Suwon 441-706, Korea
| | - Han Ha Chai
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Suwon 441-706, Korea
| | - Hwan Hoo Seong
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Suwon 441-706, Korea
| | - Bo Suk Yang
- Hanwoo Experiment Station, National Institute of Animal Science, RDA, PyeongChang 232-950, Korea
| | - Seong Koo Hong
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Suwon 441-706, Korea
| | - Won Kyung Chang
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Suwon 441-706, Korea
| | - Seung Hwan Lee
- Hanwoo Experiment Station, National Institute of Animal Science, RDA, PyeongChang 232-950, Korea
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26
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Renes J, Mariman E. Application of proteomics technology in adipocyte biology. MOLECULAR BIOSYSTEMS 2013; 9:1076-91. [PMID: 23629546 DOI: 10.1039/c3mb25596d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Obesity and its associated complications have reached epidemic proportions in Western-type societies. Concomitantly, the obesity incidence in developing countries is increasing. One hallmark of obesity is the differentiation of pre-adipocytes into mature triglyceride-loaded adipocytes present in subcutaneous and visceral adipose tissue depots. This may ultimately lead to dysfunctional adipose tissue together with detrimental changes in the profiles of (pre-)adipocyte-secreted proteins, known as adipokines. Obesity-induced alterations in adipokine profiles contribute to the development of obesity-associated disorders. Consequently, the interest in the molecular events responsible for adipose tissue modifications during weight gain and weight loss as well as in the aetiology of obesity-associated disorders is growing. Molecular mechanisms involved in pre-adipocyte differentiation and alterations in adipokine profiles have been examined at the gene and protein level by high-throughput technologies. Independent proteomics studies have contributed significantly to further insight into adipocyte biology, particularly with respect to adipokine profiling. In this review novel findings obtained with adipo-proteomics studies are highlighted and the relevance of proteomics technologies to further understand molecular aspects of adipocyte biology is discussed.
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Affiliation(s)
- Johan Renes
- Department of Human Biology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
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27
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Abstract
Obesity significantly increases the risk of developing type 2 diabetes, hypertension, coronary heart disease, stroke, fatty liver disease, dementia, obstructive sleep apnea and several types of cancer. Adipocyte and adipose tissue dysfunction represent primary defects in obesity and may link obesity to metabolic and cardiovascular diseases. Adipose tissue (AT) dysfunction manifests by a proinflammatory adipokine secretion pattern that mediate auto/paracrine and endocrine communication and by inflammatory cell infiltration, particularly in intra-abdominal fat. Impaired AT function is caused by the interaction of genetic, behavioral and environmental factors which lead to adipocyte hypertrophy, ectopic fat accumulation, hypoxia, AT stresses, impaired AT mitochondrial function and inflammatory processes within adipose tissue. Recently, increased autophagy has been linked to obesity and AT dysfunction and may represent a mechanism to compensate for AT stresses. A better understanding of mechanisms causing or maintaining AT dysfunction may provide new therapeutic strategies in the treatment of obesity-induced metabolic diseases.
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Affiliation(s)
- Matthias Blüher
- Department of Medicine, University of Leipzig, Liebigstr. 20, 04103 Leipzig, Germany.
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28
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Ye J, Gimble JM. Regulation of stem cell differentiation in adipose tissue by chronic inflammation. Clin Exp Pharmacol Physiol 2012; 38:872-8. [PMID: 21883381 DOI: 10.1111/j.1440-1681.2011.05596.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
1. Recent studies suggest that a local hypoxic response leads to chronic inflammation in the adipose tissue of obese individuals. The adipose tissue hypoxia may reflect a compensatory failure in the local vasculature system in response to obesity. 2. Studies suggest that inflammation stimulates angiogenesis and inhibits adipocyte activities in a feedback manner within the obese adipose tissue. Adipose-derived stem cells (ASC) are able to differentiate into multiple lineages of progenitor cells for adipocytes, endothelial cells, fibroblasts and pericytes. Differentiation of ASC into those progenitors is regulated by the adipose tissue microenvironment. 3. As a major factor in the microenvironment, inflammation may favour ASC differentiation into endothelial cells through the induction of angiogenic factors. At the same time, inflammation inhibits ASC differentiation into adipocytes by suppressing peroxisome proliferator-activated receptor γ activity and the insulin signalling pathway. In this context, inflammation may serve as a signal mediating the competition between adipocytes and endothelial cells for the limited source of ASC. 4. It is a new concept that inflammation mediates signals in the competition between adipocytes and endothelial cells for the limited ASC in obesity. There is a lot of evidence that inflammation promotes endothelial cell differentiation. However, this activity of inflammation remains to be established in adipose tissue. The present article reviews the literature in support of this conclusion.
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Affiliation(s)
- Jianping Ye
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA.
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29
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Berti DA, Russo LC, Castro LM, Cruz L, Gozzo FC, Heimann JC, Lima FB, Oliveira AC, Andreotti S, Prada PO, Heimann AS, Ferro ES. Identification of intracellular peptides in rat adipose tissue: Insights into insulin resistance. Proteomics 2012; 12:2668-81. [DOI: 10.1002/pmic.201200051] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 05/08/2012] [Accepted: 05/10/2012] [Indexed: 01/07/2023]
Affiliation(s)
- Denise A. Berti
- Department of Cell Biology and Development; University of São Paulo; São Paulo Brazil
| | - Lilian C. Russo
- Department of Cell Biology and Development; University of São Paulo; São Paulo Brazil
| | - Leandro M. Castro
- Department of Cell Biology and Development; University of São Paulo; São Paulo Brazil
| | - Lilian Cruz
- Department of Cell Biology and Development; University of São Paulo; São Paulo Brazil
| | - Fábio C. Gozzo
- Chemistry Institute; Campinas State University; Campinas São Paulo Brazil
| | - Joel C. Heimann
- Department of Internal Medicine; School of Medicine; University of São Paulo; São Paulo Brazil
| | - Fabio B. Lima
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo Brazil
| | - Ariclécio C. Oliveira
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo Brazil
| | - Sandra Andreotti
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo Brazil
| | - Patrícia O. Prada
- Chemistry Institute; Campinas State University; Campinas São Paulo Brazil
| | | | - Emer S. Ferro
- Department of Cell Biology and Development; University of São Paulo; São Paulo Brazil
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30
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Abstract
The adipocyte enlargement is associated with an increase in the cytoplasmic lipid content, but how the plasma membrane area follows this increase is poorly understood. We monitored single-cell membrane surface area fluctuations, which mirror the dynamics of exocytosis and endocytosis. We employed the patch-clamp technique to measure membrane capacitance (C(m)), a parameter linearly related to the plasma membrane area. Specifically, we studied whether insulin affects membrane area dynamics in adipocytes. A five-minute cell exposure to insulin increased resting C(m) by 12 ± 4%; in controls the change in C(m) was not different from zero. We measured cell diameter of isolated rat adipocytes microscopically. Twenty-four hour exposure of cells to insulin resulted in a significant increase in cell diameter by 5.1 ± 0.6%. We conclude that insulin induces membrane area increase, which may in chronic hyperinsulinemia promote the enlargement of plasma membrane area, acting in concert with other insulin-mediated metabolic effects on adipocytes.
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Affiliation(s)
- H H Chowdhury
- Laboratory of Neuroendocrinology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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31
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Wree A, Mayer A, Westphal S, Beilfuss A, Canbay A, Schick RR, Gerken G, Vaupel P. Adipokine expression in brown and white adipocytes in response to hypoxia. J Endocrinol Invest 2012; 35:522-7. [PMID: 21952510 DOI: 10.3275/7964] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Adipose tissue has emerged as an important endocrine regulator by secreting hormones referred to as adipokines. Recent studies showed that adipose tissue considerably responds to hypoxia. Although the impact of white adipose tissue on regulative processes is established, the importance of brown adipose tissue in adults has emerged just recently. METHODS Brown (BA) and white adipocytes (WA) were cultured either in the presence of chemical hypoxia-mimetics or under hypoxic atmosphere of 1% oxygen. Expression of hypoxia-inducible factor 1α (HIF- 1α) was assessed by western blot. The expression levels of several known HIF-1α-regulated proteins [vascular endothelial growth factor (VEGF), leptin, adiponectin, and angiotensinogen (AGT)] were quantified. RESULTS Both chemical hypoxia-mimetics and physical hypoxia led to increased nuclear HIF-1α expression and to decreased cytoplasmatic adiponectin in both cell types. In contrast, VEGF and AGT expression did not change upon hypoxic stimulation. Leptin was exclusively detectable in WA, while uncoupling-protein 1 (UCP-1) was expressed in BA only. CONCLUSIONS WA and BA are sensitive to hypoxia, in which HIF-1α expression is induced. Protein expression of adiponectin is hypoxia-dependent, whereas AGT, VEGF, leptin, and UCP-1 expression do not change secondary to hypoxia.
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Affiliation(s)
- A Wree
- Department of Gastroenterology and Hepatology, University of Essen, University Hospital Essen, Hufelandstrasse 55, 45122 Essen, Germany.
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32
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Peinado JR, Pardo M, de la Rosa O, Malagón MM. Proteomic characterization of adipose tissue constituents, a necessary step for understanding adipose tissue complexity. Proteomics 2012; 12:607-20. [PMID: 22246603 DOI: 10.1002/pmic.201100355] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 08/17/2011] [Accepted: 08/30/2011] [Indexed: 01/03/2023]
Abstract
The original concept of adipose tissue as an inert storage depot for the excess of energy has evolved over the last years and it is now considered as one of the most important organs regulating body homeostasis. This conceptual change has been supported by the demonstration that adipose tissue serves as a major endocrine organ, producing a wide variety of bioactive molecules, collectively termed adipokines, with endocrine, paracrine and autocrine activities. Adipose tissue is indeed a complex organ wherein mature adipocytes coexist with the various cell types comprising the stromal-vascular fraction (SVF), including preadipocytes, adipose-derived stem cells, perivascular cells, and blood cells. It is known that not only mature adipocytes but also the components of SVF produce adipokines. Furthermore, adipokine production, proliferative and metabolic activities and response to regulatory signals (i.e. insulin, catecholamines) differ between the different fat depots, which have been proposed to underlie their distinct association to specific diseases. Herein, we discuss the recent proteomic studies on adipose tissue focused on the analysis of the separate cellular components and their secretory products, with the aim of identifying the basic features and the contribution of each component to different adipose tissue-associated pathologies.
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Affiliation(s)
- Juan R Peinado
- Faculty of Medicine, Departament of Medical Sciences, Ciudad Real, Spain.
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33
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Sarr O, Louveau I, Le Huërou-Luron I, Gondret F. Adipose tissue proteomes of intrauterine growth-restricted piglets artificially reared on a high-protein neonatal formula. J Nutr Biochem 2012; 23:1417-24. [PMID: 22221677 DOI: 10.1016/j.jnutbio.2011.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 09/06/2011] [Accepted: 09/08/2011] [Indexed: 02/03/2023]
Abstract
The eventuality that adipose tissues adapt to neonatal nutrition in a way that may program later adiposity or obesity in adulthood is receiving increasing attention in neonatology. This study assessed the immediate effects of a high-protein neonatal formula on proteome profiles of adipose tissues in newborn piglets with intrauterine growth restriction. Piglets (10th percentile) were fed milk replacers formulated to provide an adequate (AP) or a high (HP) protein supply from day 2 to the day prior weaning (day 28, n=5 per group). Adipocytes with small diameters were present in greater proportions in subcutaneous and perirenal adipose tissues from HP piglets compared with AP ones at this age. Two-dimensional gel electrophoresis analysis of adipose tissue depots revealed a total of 32 protein spots being up- or down-regulated (P<.10) for HP piglets compared with AP piglets; 18 of them were unambiguously identified by mass spectrometry. These proteins were notably related to signal transduction (annexin 2), redox status (peroxiredoxin 6, glutathione S-transferase omega 1, cyclophilin-A), carbohydrate metabolism (ribose-5-phosphate dehydrogenase, lactate dehydrogenase), amino acid metabolism (glutamate dehydrogenase 1) and cell cytoskeleton dynamics (dynactin and cofilin-1). Proteomic changes occurred mainly in dorsal subcutaneous adipose tissue, with the notable exception of annexin 1 involved in lipid metabolic process having a lower abundance in HP piglets for perirenal adipose tissue only. Together, modulation in those proteins could represent a novel starting point for elucidating catch-up fat growth observed in later life in growing animals having been fed HP formula.
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Affiliation(s)
- Ousseynou Sarr
- INRA, UMR1079 Systèmes d'Elevage Nutrition Animale et Humaine, F-35590 Saint-Gilles, France
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34
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Hyperinsulinemia leads to uncoupled insulin regulation of the GLUT4 glucose transporter and the FoxO1 transcription factor. Proc Natl Acad Sci U S A 2011; 108:10162-7. [PMID: 21646544 DOI: 10.1073/pnas.1019268108] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Insulin resistance is a component of the metabolic syndrome and Type 2 diabetes. It has been recently shown that in liver insulin resistance is not complete. This so-called selective insulin resistance is characterized by defective insulin inhibition of hepatic glucose output while insulin-induced lipogenesis is maintained. How this occurs and whether uncoupled insulin action develops in other tissues is unknown. Here we show in a model of chronic hyperinsulinemia that adipocytes develop selective insulin resistance in which translocation of the GLUT4 glucose transporter to the cell surface is blunted yet nuclear exclusion of the FoxO1 transcription factor is preserved, rendering uncoupled insulin-controlled carbohydrate and lipid metabolisms. We found that in adipocytes FoxO1 nuclear exclusion has a lower half-maximal insulin dose than GLUT4 translocation, and it is because of this inherent greater sensitivity that control of FoxO1 by physiological insulin concentrations is maintained in adipocytes with compromised insulin signaling. Pharmacological and genetic interventions revealed that insulin regulates GLUT4 and FoxO1 through the PI3-kinase isoform p110α, although FoxO1 showed higher sensitivity to p110α activity than GLUT4. Transient down-regulation and overexpression of Akt isoforms in adipocytes demonstrated that insulin-activated PI3-kinase signals to GLUT4 primarily through Akt2 kinase, whereas Akt1 and Akt2 signal to FoxO1. We propose that the lower threshold of insulin activity for FoxO1's nuclear exclusion is in part due to its regulation by both Akt isoforms. Identification of uncoupled insulin action in adipocytes suggests this condition might be a general phenomenon of insulin target tissues contributing to insulin resistance's pathophysiology.
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35
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Abstract
In obesity, the vascular complication is a result of insulin resistance, such as decreased capillary recruitment in skeletal muscle from endothelial insulin resistance. Recent progress in the study of obesity-associated inflammation suggests that vasculature dysfunction occurs in adipose tissue before insulin resistance. In obesity, capillary density and function fail to meet the demand of adipose tissue growth. The failure leads to microcirculation dysfunction from an impaired blood perfusion, which results in a local hypoxia response in adipose tissue. The hypoxia response in adipocytes and macrophages is a new cellular basis for the chronic inflammation. The obesity-associated inflammation has both positive and negative effects in the body. At the early stage, it amplifies the hypoxia signal to stimulate vasculature remodeling locally, and promotes systemic energy expenditure against obesity. At the late stage, it causes adipose tissue dysfunction for insulin resistance. These points suggest that in obesity, adipose tissue vascularization controls chronic inflammation and influences systemic insulin sensitivity.
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Affiliation(s)
- Jianping Ye
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA.
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36
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Deng Y, Scherer PE. Adipokines as novel biomarkers and regulators of the metabolic syndrome. Ann N Y Acad Sci 2011. [PMID: 21276002 DOI: 10.1111/j.1749-6632.2010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Over the past two decades our view of adipose tissue has undergone a dramatic change from an inert energy storage tissue to an active endocrine organ. Adipose tissue communicates with other central and peripheral organs by synthesis and secretion of a host of molecules that we generally refer to as adipokines. The levels of some adipokines correlate with specific metabolic states and have the potential to impact directly upon the metabolic homeostasis of the system. A dysregulation of adipokines has been implicated in obesity, type 2 diabetes, hypertension, cardiovascular disease, and an ever-growing larger list of pathological changes in a number of organs. Here, we review the recent progress regarding the synthesis, secretion, and physiological function of adipokines with perspectives on future directions and potential therapeutic goals.
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Affiliation(s)
- Yingfeng Deng
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, USA
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37
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Deng Y, Scherer PE. Adipokines as novel biomarkers and regulators of the metabolic syndrome. Ann N Y Acad Sci 2011; 1212:E1-E19. [PMID: 21276002 DOI: 10.1111/j.1749-6632.2010.05875.x] [Citation(s) in RCA: 360] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Over the past two decades our view of adipose tissue has undergone a dramatic change from an inert energy storage tissue to an active endocrine organ. Adipose tissue communicates with other central and peripheral organs by synthesis and secretion of a host of molecules that we generally refer to as adipokines. The levels of some adipokines correlate with specific metabolic states and have the potential to impact directly upon the metabolic homeostasis of the system. A dysregulation of adipokines has been implicated in obesity, type 2 diabetes, hypertension, cardiovascular disease, and an ever-growing larger list of pathological changes in a number of organs. Here, we review the recent progress regarding the synthesis, secretion, and physiological function of adipokines with perspectives on future directions and potential therapeutic goals.
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Affiliation(s)
- Yingfeng Deng
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, USA
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38
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Cruz-Garcia L, Sánchez-Gurmaches J, Bouraoui L, Saera-Vila A, Pérez-Sánchez J, Gutiérrez J, Navarro I. Changes in adipocyte cell size, gene expression of lipid metabolism markers, and lipolytic responses induced by dietary fish oil replacement in gilthead sea bream (Sparus aurata L.). Comp Biochem Physiol A Mol Integr Physiol 2010; 158:391-9. [PMID: 21130894 DOI: 10.1016/j.cbpa.2010.11.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2010] [Revised: 11/23/2010] [Accepted: 11/23/2010] [Indexed: 01/28/2023]
Abstract
The effects of fish oil (FO) substitution by 66% vegetable oils in a diet with already 75% vegetable protein (66VO) on adipose tissue lipid metabolism of gilthead sea bream were analysed after a 14-month feeding trial. In the last 3 months of the experiment, a FO diet was administrated to a 66VO group (group 66VO/FO) as a finishing diet. Hormone-sensitive lipase (HSL) activity was measured in adipose tissue and adipocyte size, and HSL, lipoprotein lipase and liver X receptor gene expression in isolated adipocytes, on which lipolysis and glucose uptake experiments were also performed. Lipolysis was measured after incubation with tumour necrosis factor-α (TNFα), linoleic acid, and two conjugated linoleic acid isomers. Glucose uptake was analysed after TNFα or insulin administration. Our results show that FO replacement increased lipolytic activity and adipocyte cell size. The higher proportion of large cells observed in the 66VO group could be involved in their observed lower response to fatty acid treatments and lower insulin sensitivity. The 66VO/FO group showed a moderate return to the FO conditions. Therefore, FO replacement can affect the morphology and metabolism of gilthead sea bream adipocytes which could potentially affect other organs such as the liver.
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Affiliation(s)
- Lourdes Cruz-Garcia
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain.
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Varlamov O, Somwar R, Cornea A, Kievit P, Grove KL, Roberts CT. Single-cell analysis of insulin-regulated fatty acid uptake in adipocytes. Am J Physiol Endocrinol Metab 2010; 299:E486-96. [PMID: 20570821 PMCID: PMC2944284 DOI: 10.1152/ajpendo.00330.2010] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Increased body fat correlates with the enlargement of average fat cell size and reduced adipose tissue insulin sensitivity. It is currently unclear whether adipocytes, as they accumulate more triglycerides and grow in size, gradually become less insulin sensitive or whether obesity-related factors independently cause both the enlargement of adipocyte size and reduced adipose tissue insulin sensitivity. In the first instance, large and small adipocytes in the same tissue would exhibit differences in insulin sensitivity, whereas, in the second instance, adipocyte size per se would not necessarily correlate with insulin response. To analyze the effect of adipocyte size on insulin sensitivity, we employed a new single-cell imaging assay that resolves fatty acid uptake and insulin response in single adipocytes in subcutaneous adipose tissue explants. Here, we report that subcutaneous adipocytes are heterogeneous in size and intrinsic insulin sensitivity. Whereas smaller adipocytes respond to insulin by increasing lipid uptake, adipocytes with cell diameters larger than 80-100 microm are insulin resistant. We propose that, when cell size approaches a critical boundary, adipocytes lose insulin-dependent fatty acid transport. This negative feedback mechanism may protect adipocytes from lipid overload and restrict further expansion of adipose tissue, which leads to obesity and metabolic complications.
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Affiliation(s)
- Oleg Varlamov
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, 97006, USA
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Lee KT, Byun MJ, Lim D, Kang KS, Kim NS, Oh JH, Chung CS, Park HS, Shin Y, Kim TH. Full-length enriched cDNA library construction from tissues related to energy metabolism in pigs. Mol Cells 2009; 28:529-36. [PMID: 19937143 DOI: 10.1007/s10059-009-0147-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 09/02/2009] [Accepted: 09/17/2009] [Indexed: 02/03/2023] Open
Abstract
Genome sequencing of the pig is being accelerated because of its importance as an evolutionary and biomedical model animal as well as a major livestock animal. However, information on expressed porcine genes is insufficient to allow annotation and use of the genomic information. A series of expressed sequence tags of 5' ends of five full-length enriched cDNA libraries (SUSFLECKs) were functionally characterized. SUSFLECKs were constructed from porcine abdominal fat, induced fat cells, loin muscle, liver, and pituitary gland, and were composed of non-normalized and normalized libraries. A total of 55,658 ESTs that were sequenced once from the 5' ends of clones were produced and assembled into 17,684 unique sequences with 7,736 contigs and 9,948 singletons. In Gene Ontology analysis, two significant biological process leaf nodes were found: gluconeogenesis and translation elongation. In functional domain analysis based on the Pfam database, the beta transducin repeat domain of WD40 protein was the most frequently occurring domain. Twelve genes, including SLC25A6, EEF1G, EEF1A1, COX1, ACTA1, SLA, and ANXA2, were significantly more abundant in fat tissues than in loin muscle, liver, and pituitary gland in the SUSFLECKs. These characteristics of SUSFLECKs determined by EST analysis can provide important insight to discover the functional pathways in gene networks and to expand our understanding of energy metabolism in the pig.
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Affiliation(s)
- Kyung-Tai Lee
- Division of Animal Genomics and Bioinformatics, National Institute of Animal Science, Rural Development Administration, Suwon 441-707, Korea
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Pasarica M, Tchoukalova YD, Heilbronn LK, Fang X, Albu JB, Kelley DE, Smith SR, Ravussin E. Differential effect of weight loss on adipocyte size subfractions in patients with type 2 diabetes. Obesity (Silver Spring) 2009; 17:1976-8. [PMID: 19629054 PMCID: PMC3985333 DOI: 10.1038/oby.2009.219] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The size of adipocytes influences their function suggesting a differential responsiveness to intervention. We hypothesized that weight loss in patients with type 2 diabetes mellitus (T2DM) predominantly decreases the size of large and very-large adipocyte subfractions in parallel with beneficial changes in serum adipokines and improved insulin sensitivity. A total of 44 volunteers from the Look Action for Health in Diabetes trial, who lost weight after 1-year of intense lifestyle intervention, were included. Insulin sensitivity (hyperinsulinemic-euglycemic clamp), size of subcutaneous abdominal adipocytes (osmium fixation), and selected serum adipokines were measured. A 13% weight loss was accompanied by 46% improvement in insulin sensitivity (increased glucose disposal rate from 5.9+/-2.2 to 8.6+/-2.7 mg/min/kg fat-free mass, P<0.05) in parallel with a 36% increase in plasma adiponectin concentration (6.1+/-3.1 to 8.3+/-3.9 microg/ml, P<0.05], but no changes in the proinflammatory cytokines interleukin-6 and tumor necrosis factor-alpha. Change in adiponectin correlated with changes in glucose disposal rate (r=0.34, P<0.05). Mean adipocyte size decreased (0.84+/-0.25 to 0.64+/-0.23 microl, P<0.05), mainly due to changes in the large adipocyte subfraction (size 0.75-0.44 microl, relative number 19-26%; P<0.05). Our data suggest that change in the large adipocyte subfraction may contribute to the improvement in insulin sensitivity via an increase in serum adiponectin. Such a relationship, which does not imply cause and effect, could not be obtained by measuring only mean adipocyte size. These data provide support for the measures of adipocyte size distribution in concert with in vitro adipokine secretion and lipolysis in future studies.
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Affiliation(s)
- Magdalena Pasarica
- Human Physiology, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
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42
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Chang GR, Wu YY, Chiu YS, Chen WY, Liao JW, Hsu HM, Chao TH, Hung SW, Mao FC. Long-term Administration of Rapamycin Reduces Adiposity, but Impairs Glucose Tolerance in High-Fat Diet-fed KK/HlJ Mice. Basic Clin Pharmacol Toxicol 2009; 105:188-98. [DOI: 10.1111/j.1742-7843.2009.00427.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Mishra A, Cheng CH, Lee WC, Tsai LL. Proteomic changes in the hypothalamus and retroperitoneal fat from male F344 rats subjected to repeated light-dark shifts. Proteomics 2009; 9:4017-28. [DOI: 10.1002/pmic.200800813] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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44
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Blüher M, Bashan N, Shai I, Harman-Boehm I, Tarnovscki T, Avinaoch E, Stumvoll M, Dietrich A, Klöting N, Rudich A. Activated Ask1-MKK4-p38MAPK/JNK stress signaling pathway in human omental fat tissue may link macrophage infiltration to whole-body Insulin sensitivity. J Clin Endocrinol Metab 2009; 94:2507-15. [PMID: 19351724 DOI: 10.1210/jc.2009-0002] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Adipose tissue in obesity is thought to be exposed to various stresses, predominantly in intraabdominal depots. We recently reported that p38MAPK and Jun N-terminal kinase (JNK), but not ERK and inhibitory-kappaB kinase beta, are more highly expressed and activated in human omental (OM) adipose tissue in obesity. OBJECTIVE The aim was to investigate upstream components of the pathways that culminate in activation of p38MAPK and JNK. SETTING AND PATIENTS Phosphorylation and expression of kinases were studied in paired samples of OM and sc adipose tissue from lean and obese subjects of two different cohorts (n = 36 and n = 196) by Western and real-time PCR analyses. The association with fat distribution, macrophage infiltration, insulin sensitivity, and glucose metabolism was assessed by correlation analyses. RESULTS The amount of phosphorylated forms of the kinases provided evidence for an activated stress-sensing pathway consisting of the MAP3K Ask1 (but not MLK3 or Tak1), and the MAP2Ks MKK4, 3/6, (but not MKK7), specifically in OM. OM Ask1-mRNA was more highly expressed in predominantly intraabdominally obese persons and most strongly correlated with estimated visceral fat. Diabetes was associated with higher OM Ask1-mRNA only in the lean group. In OM, macrophage infiltration strongly correlated with Ask1-mRNA, but the obesity-associated increase in Ask1-mRNA could largely be attributed to the adipocyte cell fraction. Finally, multivariate regression analyses revealed OM-Ask1 as an independent predictor of whole-body glucose uptake in euglycemic-hyperinsulinemic clamps. CONCLUSIONS An Ask1-MKK4-p38MAPK/JNK pathway reflects adipocyte stress associated with adipose tissue inflammation, linking visceral adiposity to whole-body insulin resistance in obesity.
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Affiliation(s)
- Matthias Blüher
- Department of Medicine, University of Leipzig, 04107 Leipzig, Germany
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Chang GR, Chiu YS, Wu YY, Chen WY, Liao JW, Chao TH, Mao FC. Rapamycin protects against high fat diet-induced obesity in C57BL/6J mice. J Pharmacol Sci 2009; 109:496-503. [PMID: 19372632 DOI: 10.1254/jphs.08215fp] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Rapamycin (RAPA), an immunosuprpressive drug used extensively to prevent graft rejection in transplant patients, has been reported to inhibit adipogenesis in vitro. In this study, we investigated the anti-obesity effects of RAPA in C57BL/6J mice on a high-fat diet (HFD). Mice treated with RAPA (2 mg/kg per week for 16 weeks) had reduced body weight and epididymal fat pads/body weight, reduced daily food efficiency, and lower serum leptin and insulin levels compared with the HFD control mice. However, RAPA-treated mice were hyperphagic, demonstrating an increase in food intake. Dissection of RAPA-treated mice revealed a marked reduction in fatty liver scores, average fat cell size, and percentage of large adipocytes of retroperitoneal and epididymal white adipose tissue (RWAT and EWAT), compared to the HFD control mice. These results suggest that RAPA prevented the effect of the high-fat diet on the rate of accretion in body weight via reducing lipid accumulation, despite greater food intake. It is likely that RAPA may serve as a potential strategy for body weight control and/or anti-obesity therapy.
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Affiliation(s)
- Geng-Ruei Chang
- Department of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
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46
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Abstract
Recent studies consistently support a hypoxia response in the adipose tissue in obese animals. The observations have led to the formation of an exciting concept, adipose tissue hypoxia (ATH), in the understanding of major disorders associated with obesity. ATH may provide cellular mechanisms for chronic inflammation, macrophage infiltration, adiponectin reduction, leptin elevation, adipocyte death, endoplasmic reticulum stress and mitochondrial dysfunction in white adipose tissue in obesity. The concept suggests that inhibition of adipogenesis and triglyceride synthesis by hypoxia may be a new mechanism for elevated free fatty acids in the circulation in obesity. ATH may represent a unified cellular mechanism for a variety of metabolic disorders and insulin resistance in patients with metabolic syndrome. It suggests a new mechanism of pathogenesis of insulin resistance and inflammation in obstructive sleep apnea. In addition, it may help us to understand the beneficial effects of caloric restriction, physical exercise and angiotensin II inhibitors in the improvement of insulin sensitivity. In this review article, literatures are reviewed to summarize the evidence and possible cellular mechanisms of ATH. The directions and road blocks in the future studies are analyzed.
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Linke A, Sonnabend M, Fasshauer M, Höllriegel R, Schuler G, Niebauer J, Stumvoll M, Blüher M. Effects of extended-release niacin on lipid profile and adipocyte biology in patients with impaired glucose tolerance. Atherosclerosis 2008; 205:207-13. [PMID: 19131065 DOI: 10.1016/j.atherosclerosis.2008.11.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 11/05/2008] [Accepted: 11/26/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Low high-density lipoprotein cholesterol (HDL-C) serum concentrations are independent risk factors for the development of coronary artery disease. In patients with the metabolic syndrome, low HDL-C can contribute to premature atherosclerosis. Extended-release (ER) niacin increases HDL-C and was shown to slow the progression of atherosclerosis. Adipose tissue is an important site of niacin action. Here we sought to determine potential pleiotropic effects of ER niacin on adipose tissue biology in patients with impaired glucose tolerance (IGT). METHODS AND RESULTS Thirty patients with IGT (mean age=45.2+/-3.9 years), low HDL-C serum concentrations (HDL-C <1.0 mmol/l), but no additional comorbidities were treated once-daily with ER niacin (1000 mg) in a randomized open-label controlled (n=30) study for 6 months. During the first 4 weeks, daily dose was increased from 375 to 1000 mg in weekly intervals. At baseline and after 6 months, subcutaneous adipose tissue biopsies were taken, body fat mass, insulin sensitivity (euglycemic-hyperinsulinemic clamp), and adipokine serum concentrations were measured. After 6 months of ER niacin treatment, HDL-C increased significantly by 24% and adiponectin by 35%. In addition, ER niacin significantly reduced circulating lipoprotein (a) by 38% (p<0.001) and fasting triglycerides by 12% (p<0.05). Whole-body insulin sensitivity increased in the ER niacin treatment group, although this trend was not statistically significant (p=0.085). Six months ER niacin led to a significant reduction in mean adipocyte size associated with increased insulin sensitivity in isolated adipocytes and gene expression changes including increased adiponectin, C/EBPalpha, C/EBPdelta, PPARgamma and decreased carnitine palmitoyl transferase 2, hormone sensitive lipase, nicotinic acid receptor (GPR109B) and fatty-acid synthase mRNA expression. CONCLUSION Treatment with ER niacin significantly improves atherogenic lipid profile in patients with IGT. These beneficial effects could at least in part be due to pleiotropic niacin effects in adipose tissue, characterized by decreased mean adipocyte size, increased insulin sensitivity and altered mRNA expression profile.
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Affiliation(s)
- Axel Linke
- Department of Cardiology, Heart Center, University of Leipzig, Leipzig, Germany
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Labrecque B, Mathieu O, Bordignon V, Murphy BD, Palin MF. Identification of differentially expressed genes in a porcine in vivo model of adipogenesis using suppression subtractive hybridization. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2008; 4:32-44. [PMID: 20403744 DOI: 10.1016/j.cbd.2008.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2008] [Revised: 10/14/2008] [Accepted: 10/15/2008] [Indexed: 12/13/2022]
Abstract
Although they provide valuable information, in vitro models of adipocyte development often require high doses of hormones and growth factors, which may influence gene expression and adipocyte differentiation patterns. To overcome these problems, a novel in vivo model of adipose tissue development was used to characterize genes involved in adipogenesis. The suppression subtractive hybridization technique was used to identify genes showing differential expression between the adipose tissue of a day 90 gestating sow, which is enriched in adipocytes, and day 90 fetal adipose tissue, which is enriched in preadipocytes. A total of 149 expressed sequence tags corresponding to identified genes and tentative consensus sequences emerged. Thirty-seven clones matched expressed sequence tags or genomic DNA sequences and six novel sequences were also identified. Adipogenesis-related genes were identified, many of which have never been reported to be expressed in mammalian adipose tissue, and may play a role in regulation of adipose tissue differentiation. Validation of differentially expressed genes was confirmed for perilipin, monocyte to macrophage differentiation-associated, myocilin, paraoxonase 3, stearoyl-CoA desaturase, angiotensinogen and adiponectin genes using real-time RT-PCR.
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Affiliation(s)
- Benoît Labrecque
- Centre de Recherche en Reproduction Animale, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec J2S7C6, Canada
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Gondret F, Guitton N, Guillerm-Regost C, Louveau I. Regional differences in porcine adipocytes isolated from skeletal muscle and adipose tissues as identified by a proteomic approach. J Anim Sci 2008; 86:2115-25. [DOI: 10.2527/jas.2007-0750] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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50
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Yue L, Christman JW, Mazzone T. Tumor necrosis factor-alpha-mediated suppression of adipocyte apolipoprotein E gene transcription: primary role for the nuclear factor (NF)-kappaB pathway and NFkappaB p50. Endocrinology 2008; 149:4051-8. [PMID: 18467438 PMCID: PMC2488247 DOI: 10.1210/en.2008-0340] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The adipose tissue inflammation accompanying obesity has important consequences for adipocyte lipid metabolism, and increased adipose tissue TNFalpha plays an important role for mediating the effect of inflammation on adipocyte function. Recent studies have shown that apolipoprotein E (apoE) is highly expressed in adipose tissue where it plays an important role in modulating adipocyte triglyceride metabolism, triglyceride mass, and adipocyte size. We have previously reported that TNFalpha reduces adipocyte apoE, and the current studies were undertaken to evaluate the molecular mechanism for this regulation. TNFalpha repression of adipocyte apoE gene expression required an intact nuclear factor (NF)-kappaB binding site at -43 in the apoE promoter. Site-directed mutagenesis at this site completely eliminated TNFalpha regulation of an apoE gene reporter. TNFalpha treatment activated binding of NFkappaB p50, isolated from adipocyte nuclei, to the apoE promoter. Two structurally distinct inhibitors of NFkappaB complex activation or translocation abrogated the TNFalpha effect on the apoE gene. Using chromatin immunoprecipitation assays, we demonstrated that treatment of adipocytes with TNFalpha led to increased binding of NFkappaB p50, and decreased binding of p65 and Sp1, to this region of the apoE promoter in living cells. The key role played by increased p50 binding was confirmed by p50 knockdown experiments. Reduction of p50 expression using small interference RNA completely eliminated TNFalpha-mediated reduction of endogenous adipocyte apoE gene expression. These results establish the molecular link between adipose tissue inflammation and apoE gene expression in adipocytes. The suppression of adipocyte apoE by the proinflammatory adipose tissue milieu associated with obesity will have important downstream effects on adipocyte triglyceride turnover and content.
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Affiliation(s)
- Lili Yue
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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