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Ferrero R, Rainer PY, Rumpler M, Russeil J, Zachara M, Pezoldt J, van Mierlo G, Gardeux V, Saelens W, Alpern D, Favre L, Vionnet N, Mantziari S, Zingg T, Pitteloud N, Suter M, Matter M, Schlaudraff KU, Canto C, Deplancke B. A human omentum-specific mesothelial-like stromal population inhibits adipogenesis through IGFBP2 secretion. Cell Metab 2024; 36:1566-1585.e9. [PMID: 38729152 DOI: 10.1016/j.cmet.2024.04.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 12/22/2023] [Accepted: 04/19/2024] [Indexed: 05/12/2024]
Abstract
Adipose tissue plasticity is orchestrated by molecularly and functionally diverse cells within the stromal vascular fraction (SVF). Although several mouse and human adipose SVF cellular subpopulations have by now been identified, we still lack an understanding of the cellular and functional variability of adipose stem and progenitor cell (ASPC) populations across human fat depots. To address this, we performed single-cell and bulk RNA sequencing (RNA-seq) analyses of >30 SVF/Lin- samples across four human adipose depots, revealing two ubiquitous human ASPC (hASPC) subpopulations with distinct proliferative and adipogenic properties but also depot- and BMI-dependent proportions. Furthermore, we identified an omental-specific, high IGFBP2-expressing stromal population that transitions between mesothelial and mesenchymal cell states and inhibits hASPC adipogenesis through IGFBP2 secretion. Our analyses highlight the molecular and cellular uniqueness of different adipose niches, while our discovery of an anti-adipogenic IGFBP2+ omental-specific population provides a new rationale for the biomedically relevant, limited adipogenic capacity of omental hASPCs.
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Affiliation(s)
- Radiana Ferrero
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Pernille Yde Rainer
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Marie Rumpler
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Julie Russeil
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Magda Zachara
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Joern Pezoldt
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Guido van Mierlo
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Vincent Gardeux
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Wouter Saelens
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Daniel Alpern
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Lucie Favre
- Department of Endocrinology, Diabetology and Metabolism, University Hospital of Lausanne (CHUV), 1011 Lausanne, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne 1005, Switzerland
| | - Nathalie Vionnet
- Department of Endocrinology, Diabetology and Metabolism, University Hospital of Lausanne (CHUV), 1011 Lausanne, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne 1005, Switzerland
| | - Styliani Mantziari
- Department of Visceral Surgery, University Hospital of Lausanne (CHUV), Lausanne 1011, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne 1005, Switzerland
| | - Tobias Zingg
- Department of Visceral Surgery, University Hospital of Lausanne (CHUV), Lausanne 1011, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne 1005, Switzerland
| | - Nelly Pitteloud
- Department of Endocrinology, Diabetology and Metabolism, University Hospital of Lausanne (CHUV), 1011 Lausanne, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne 1005, Switzerland
| | - Michel Suter
- Department of Visceral Surgery, University Hospital of Lausanne (CHUV), Lausanne 1011, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne 1005, Switzerland
| | - Maurice Matter
- Department of Visceral Surgery, University Hospital of Lausanne (CHUV), Lausanne 1011, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne 1005, Switzerland
| | | | - Carles Canto
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Bart Deplancke
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland.
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2
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Priscilla L, Yoo C, Jang S, Park S, Lim G, Kim T, Lee DY. Immunotherapy targeting the obese white adipose tissue microenvironment: Focus on non-communicable diseases. Bioact Mater 2024; 35:461-476. [PMID: 38404641 PMCID: PMC10884763 DOI: 10.1016/j.bioactmat.2024.01.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/14/2024] [Accepted: 01/30/2024] [Indexed: 02/27/2024] Open
Abstract
Obesity triggers inflammatory responses in the microenvironment of white adipose tissue, resulting in chronic systemic inflammation and the subsequent development of non-communicable diseases, including type 2 diabetes, coronary heart disease, and breast cancer. Current therapy approaches for obesity-induced non-communicable diseases persist in prioritizing symptom remission while frequently overlooking the criticality of targeting and alleviating inflammation at its source. Accordingly, this review highlights the importance of the microenvironment of obese white adipose tissue and the promising potential of employing immunotherapy to target it as an effective therapeutic approach for non-communicable diseases induced by obesity. Additionally, this review discusses the challenges and offers perspective about the immunotherapy targeting the microenvironment of obese white adipose tissue.
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Affiliation(s)
- Lia Priscilla
- Department of Bioengineering, College of Engineering, and BK FOUR Biopharmaceutical Innovation Leader for Education and Research Group, Hanyang University, Seoul, 04763, Republic of Korea
| | - Chaerim Yoo
- Department of Bioengineering, College of Engineering, and BK FOUR Biopharmaceutical Innovation Leader for Education and Research Group, Hanyang University, Seoul, 04763, Republic of Korea
| | - Seonmi Jang
- Department of Bioengineering, College of Engineering, and BK FOUR Biopharmaceutical Innovation Leader for Education and Research Group, Hanyang University, Seoul, 04763, Republic of Korea
| | - Sewon Park
- Department of Bioengineering, College of Engineering, and BK FOUR Biopharmaceutical Innovation Leader for Education and Research Group, Hanyang University, Seoul, 04763, Republic of Korea
| | - Gayoung Lim
- Department of Bioengineering, College of Engineering, and BK FOUR Biopharmaceutical Innovation Leader for Education and Research Group, Hanyang University, Seoul, 04763, Republic of Korea
| | - Taekyun Kim
- Department of Bioengineering, College of Engineering, and BK FOUR Biopharmaceutical Innovation Leader for Education and Research Group, Hanyang University, Seoul, 04763, Republic of Korea
| | - Dong Yun Lee
- Department of Bioengineering, College of Engineering, and BK FOUR Biopharmaceutical Innovation Leader for Education and Research Group, Hanyang University, Seoul, 04763, Republic of Korea
- Institute of Nano Science and Technology (INST) & Institute for Bioengineering and Biopharmaceutical Research (IBBR), Hanyang University, Seoul, 04763, Republic of Korea
- Elixir Pharmatech Inc., Seoul, 07463, Republic of Korea
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3
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Hagberg CE, Spalding KL. White adipocyte dysfunction and obesity-associated pathologies in humans. Nat Rev Mol Cell Biol 2024; 25:270-289. [PMID: 38086922 DOI: 10.1038/s41580-023-00680-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2023] [Indexed: 02/10/2024]
Abstract
The prevalence of obesity and associated chronic diseases continues to increase worldwide, negatively impacting on societies and economies. Whereas the association between excess body weight and increased risk for developing a multitude of diseases is well established, the initiating mechanisms by which weight gain impairs our metabolic health remain surprisingly contested. In order to better address the myriad of disease states associated with obesity, it is essential to understand adipose tissue dysfunction and develop strategies for reinforcing adipocyte health. In this Review we outline the diverse physiological functions and pathological roles of human white adipocytes, examining our current knowledge of why white adipocytes are vital for systemic metabolic control, yet poorly adapted to our current obesogenic environment.
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Affiliation(s)
- Carolina E Hagberg
- Division of Cardiovascular Medicine, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Kirsty L Spalding
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
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4
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Tremblay EJ, Tchernof A, Pelletier M, Joanisse DR, Mauriège P. Plasma adiponectin/leptin ratio associates with subcutaneous abdominal and omental adipose tissue characteristics in women. BMC Endocr Disord 2024; 24:39. [PMID: 38481206 PMCID: PMC10938796 DOI: 10.1186/s12902-024-01567-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 03/05/2024] [Indexed: 03/17/2024] Open
Abstract
BACKGROUND A better understanding of adipose tissue (AT) dysfunction, which includes morphological and functional changes such as adipocyte hypertrophy as well as impaired adipogenesis, lipid storage/mobilization, endocrine and inflammatory responses, is needed in the context of obesity. One dimension of AT dysfunction, secretory adiposopathy, often assessed as a low plasma adiponectin (A)/leptin (L) ratio, is commonly observed in obesity. The aim of this study was to examine markers of AT development and metabolism in 67 women of varying age and adiposity (age: 40-62 years; body mass index, BMI: 17-41 kg/m2) according to levels of adiponectinemia, leptinemia or the plasma A/L ratio. METHODS Body composition, regional AT distribution and circulating adipokines were determined. Lipolysis was measured from glycerol release in subcutaneous abdominal (SCABD) and omental (OME) adipocytes under basal, isoproterenol-, forskolin (FSK)- and dibutyryl-cyclic AMP (DcAMP)-stimulated conditions. Adipogenesis (C/EBP-α/β/δ, PPAR-γ2 and SREBP-1c) and lipid metabolism (β2-ARs, HSL, FABP4, LPL and GLUT4) gene expression (RT-qPCR) was assessed in both fat depots. Participants in the upper versus lower tertile of adiponectin, leptin or the A/L ratio were compared. RESULTS Basal lipolysis was similar between groups. Women with a low plasma A/L ratio were characterized by higher adiposity and larger SCABD and OME adipocytes (p<0.01) compared to those with a high ratio. In OME adipocytes, women in the low adiponectinemia tertile showed higher isoproterenol-stimulated lipolysis (0.01 CONCLUSIONS Secretory adiposopathy assessed as the plasma A/L ratio, more so than adiponectin or leptin levels alone, discriminates low and elevated lipolysis in OME and SCABD adipocytes despite similar AT expression of selected genes involved in lipid metabolism.
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Affiliation(s)
- Eve-Julie Tremblay
- École de Nutrition, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec City, Canada
- Centre de recherche de l'Institut Universitaire de Cardiologie et Pneumologie de Québec (CRIUCPQ), Université Laval, Québec City, Canada
| | - André Tchernof
- École de Nutrition, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec City, Canada
- Centre de recherche de l'Institut Universitaire de Cardiologie et Pneumologie de Québec (CRIUCPQ), Université Laval, Québec City, Canada
| | - Mélissa Pelletier
- Centre de recherche de l'Institut Universitaire de Cardiologie et Pneumologie de Québec (CRIUCPQ), Université Laval, Québec City, Canada
| | - Denis R Joanisse
- Centre de recherche de l'Institut Universitaire de Cardiologie et Pneumologie de Québec (CRIUCPQ), Université Laval, Québec City, Canada
- Département de kinésiologie, Faculté de médecine, Université Laval, Québec City, Canada
| | - Pascale Mauriège
- Centre de recherche de l'Institut Universitaire de Cardiologie et Pneumologie de Québec (CRIUCPQ), Université Laval, Québec City, Canada.
- Département de kinésiologie, Faculté de médecine, Université Laval, Québec City, Canada.
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5
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Engin A. Adipose Tissue Hypoxia in Obesity: Clinical Reappraisal of Hypoxia Hypothesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1460:329-356. [PMID: 39287857 DOI: 10.1007/978-3-031-63657-8_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2024]
Abstract
Obese subjects exhibit lower adipose tissue oxygen consumption in accordance with the lower adipose tissue blood flow. Thereby, compared to lean subjects, obese individuals have almost half lower capillary density and more than half lower vascular endothelial growth factor (VEGF). The VEGF expression together with hypoxia-inducible transcription factor-1 alpha (HIF-1α) activity also requires phosphatidylinositol 3-kinase (PI3K) and mammalian target of rapamycin (mTOR)-mediated signaling. Especially HIF-1α is an important signaling molecule for hypoxia to induce the inflammatory responses. Hypoxia contributes to several biological functions, such as angiogenesis, cell proliferation, apoptosis, inflammation, and insulin resistance (IR). Pathogenesis of obesity-related comorbidities is attributed to intermittent hypoxia (IH), which is mostly observed in visceral obesity. Proinflammatory phenotype of the adipose tissue is a crucial link between IH and the development of IR. Inhibition of adaptive unfolded protein response (UPR) in hypoxia increases β cell death. Moreover, deletion of HIF-1α worsens β cell function. Oxidative stress, as well as the release of proinflammatory cytokines/adipokines in obesity, is proportional to the severity of IH. Reactive oxygen species (ROS) generation at mitochondria is responsible for propagation of the hypoxic signal; however, mitochondrial ROS production is required for hypoxic HIF-1α protein stabilization. Alterations in oxygen availability of adipose tissue directly affect the macrophage polarization and are responsible for the dysregulated adipocytokines production in obesity. Hypoxia both inhibits adipocyte differentiation from preadipocytes and macrophage migration from the hypoxic adipose tissue. Upon reaching a hypertrophic threshold beyond the adipocyte fat loading capacity, excess extracellular matrix (ECM) components are deposited, causing fibrosis. HIF-1α initiates the whole pathological process of fibrosis and inflammation in the obese adipose tissue. In addition to stressed adipocytes, hypoxia contributes to immune cell migration and activation which further aggravates adipose tissue fibrosis. Therefore, targeting HIF-1α might be an efficient way to suppress hypoxia-induced pathological changes in the ECM. The fibrosis score of adipose tissue correlates negatively with the body mass index and metabolic parameters. Inducers of browning/beiging adipocytes and adipokines, as well as modulations of matrix remodeling enzyme inhibitors, and associated gene regulators, are potential pharmacological targets for treating obesity.
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Affiliation(s)
- Atilla Engin
- Faculty of Medicine, Department of General Surgery, Gazi University, Besevler, Ankara, Turkey.
- Mustafa Kemal Mah. 2137. Sok. 8/14, 06520, Cankaya, Ankara, Turkey.
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6
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Das D, Lawrence WR, Diaz-Starokozheva L, Salazar-Puerta A, Ott N, Goebel ER, Damughtala A, Vidal P, Gallentine S, Moore JT, Kayuha D, Mendonca NC, Albert JB, Houser R, Johnson J, Powell H, Higuita-Castro N, Stanford KI, Gallego-Perez D. Injectable pulverized electrospun poly(lactic-co-glycolic acid) fibers improve human adipose tissue engraftment and volume retention. J Biomed Mater Res A 2023; 111:1722-1733. [PMID: 37326365 PMCID: PMC10527741 DOI: 10.1002/jbm.a.37581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/08/2023] [Accepted: 05/31/2023] [Indexed: 06/17/2023]
Abstract
Autologous adipose tissue is commonly used for tissue engraftment for the purposes of soft tissue reconstruction due to its relative abundance in the human body and ease of acquisition using liposuction methods. This has led to the adoption of autologous adipose engraftment procedures that allow for the injection of adipose tissues to be used as a "filler" for correcting cosmetic defects and deformities in soft tissues. However, the clinical use of such methods has several limitations, including high resorption rates and poor cell survivability, which lead to low graft volume retention and inconsistent outcomes. Here, we describe a novel application of milled electrospun poly(lactic-co-glycolic acid) (PLGA) fibers, which can be co-injected with adipose tissue to improve engraftment outcomes. These PLGA fibers had no significant negative impact on the viability of adipocytes in vitro and did not elicit long-term proinflammatory responses in vivo. Furthermore, co-delivery of human adipose tissue with pulverized electrospun PLGA fibers led to significant improvements in reperfusion, vascularity, and retention of graft volume compared to injections of adipose tissue alone. Taken together, the use of milled electrospun fibers to enhance autologous adipose engraftment techniques represents a novel approach for improving upon the shortcomings of such methods.
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Affiliation(s)
- Devleena Das
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - William R. Lawrence
- Biomedical Sciences Graduate Program, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Ludmila Diaz-Starokozheva
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Department of Surgery, The Ohio State University, Columbus, OH, USA
| | - Ana Salazar-Puerta
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Neil Ott
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Erin R. Goebel
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Abhishek Damughtala
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Pablo Vidal
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Summer Gallentine
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Jordan T. Moore
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | | | - Natalia C. Mendonca
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Jared B. Albert
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Robert Houser
- Cosmetic & Plastic Surgery of Columbus, Columbus, OH, USA
| | | | - Heather Powell
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Shriners Hospitals-Ohio, Dayton, OH, USA
| | | | - Kristin I. Stanford
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Daniel Gallego-Perez
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Department of Surgery, The Ohio State University, Columbus, OH, USA
- Biomedical Sciences Graduate Program, The Ohio State University College of Medicine, Columbus, OH, USA
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7
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Markussen LK, Mandrup S. Adipocyte gene expression in obesity - insights gained and challenges ahead. Curr Opin Genet Dev 2023; 81:102060. [PMID: 37331148 DOI: 10.1016/j.gde.2023.102060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 06/20/2023]
Abstract
White adipocytes possess extraordinary plasticity with an unparalleled capacity to expand in size with nutritional overload. Several lines of evidence indicate that limitations to this plasticity, as found in both lipodystrophy and obesity, drive several of the comorbidities of these disease, thereby underscoring the need to understand the mechanisms of healthy and unhealthy adipose expansion. Recent single-cell technologies and studies of isolated adipocytes have allowed researchers to gain insight into the molecular mechanisms of adipocyte plasticity. Here, we review current insight into the effect of nutritional overload on white adipocyte gene expression and function. We review the role of adipocyte size and heterogeneity and discuss the challenges and future directions.
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Affiliation(s)
- Lasse K Markussen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark; Center for Adipocyte Signaling (ADIPOSIGN), Odense, Denmark; Center for Functional Genomics and Tissue Plasticity (ATLAS), Odense, Denmark. https://twitter.com/@ATLAS_SDU
| | - Susanne Mandrup
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark; Center for Adipocyte Signaling (ADIPOSIGN), Odense, Denmark; Center for Functional Genomics and Tissue Plasticity (ATLAS), Odense, Denmark.
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8
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Li Q, Spalding KL. The regulation of adipocyte growth in white adipose tissue. Front Cell Dev Biol 2022; 10:1003219. [PMID: 36483678 PMCID: PMC9723158 DOI: 10.3389/fcell.2022.1003219] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/03/2022] [Indexed: 10/25/2023] Open
Abstract
Adipocytes can increase in volume up to a thousand-fold, storing excess calories as triacylglycerol in large lipid droplets. The dramatic morphological changes required of adipocytes demands extensive cytoskeletal remodeling, including lipid droplet and plasma membrane expansion. Cell growth-related signalling pathways are activated, stimulating the production of sufficient amino acids, functional lipids and nucleotides to meet the increasing cellular needs of lipid storage, metabolic activity and adipokine secretion. Continued expansion gives rise to enlarged (hypertrophic) adipocytes. This can result in a failure to maintain growth-related homeostasis and an inability to cope with excess nutrition or respond to stimuli efficiently, ultimately leading to metabolic dysfunction. We summarize recent studies which investigate the functional and cellular structure remodeling of hypertrophic adipocytes. How adipocytes adapt to an enlarged cell size and how this relates to cellular dysfunction are discussed. Understanding the healthy and pathological processes involved in adipocyte hypertrophy may shed light on new strategies for promoting healthy adipose tissue expansion.
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Affiliation(s)
- Qian Li
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Kirsty L. Spalding
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
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9
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Davies DM, van den Handel K, Bharadwaj S, Lengefeld J. Cellular enlargement - A new hallmark of aging? Front Cell Dev Biol 2022; 10:1036602. [PMID: 36438561 PMCID: PMC9688412 DOI: 10.3389/fcell.2022.1036602] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 10/17/2022] [Indexed: 12/03/2023] Open
Abstract
Years of important research has revealed that cells heavily invest in regulating their size. Nevertheless, it has remained unclear why accurate size control is so important. Our recent study using hematopoietic stem cells (HSCs) in vivo indicates that cellular enlargement is causally associated with aging. Here, we present an overview of these findings and their implications. Furthermore, we performed a broad literature analysis to evaluate the potential of cellular enlargement as a new aging hallmark and to examine its connection to previously described aging hallmarks. Finally, we highlight interesting work presenting a correlation between cell size and age-related diseases. Taken together, we found mounting evidence linking cellular enlargement to aging and age-related diseases. Therefore, we encourage researchers from seemingly unrelated areas to take a fresh look at their data from the perspective of cell size.
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Affiliation(s)
- Daniel M. Davies
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Kim van den Handel
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Soham Bharadwaj
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Jette Lengefeld
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
- Center for Hematology and Regenerative Medicine, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
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10
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Important Hormones Regulating Lipid Metabolism. Molecules 2022; 27:molecules27207052. [PMID: 36296646 PMCID: PMC9607181 DOI: 10.3390/molecules27207052] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 11/17/2022] Open
Abstract
There is a wide variety of kinds of lipids, and complex structures which determine the diversity and complexity of their functions. With the basic characteristic of water insolubility, lipid molecules are independent of the genetic information composed by genes to proteins, which determine the particularity of lipids in the human body, with water as the basic environment and genes to proteins as the genetic system. In this review, we have summarized the current landscape on hormone regulation of lipid metabolism. After the well-studied PI3K-AKT pathway, insulin affects fat synthesis by controlling the activity and production of various transcription factors. New mechanisms of thyroid hormone regulation are discussed, receptor α and β may mediate different procedures, the effect of thyroid hormone on mitochondria provides a new insight for hormones regulating lipid metabolism. Physiological concentration of adrenaline induces the expression of extrapituitary prolactin in adipose tissue macrophages, which promotes fat weight loss. Manipulation of hormonal action has the potential to offer a new therapeutic horizon for the global burden of obesity and its associated complications such as morbidity and mortality.
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11
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Börgeson E, Boucher J, Hagberg CE. Of mice and men: Pinpointing species differences in adipose tissue biology. Front Cell Dev Biol 2022; 10:1003118. [PMID: 36187476 PMCID: PMC9521710 DOI: 10.3389/fcell.2022.1003118] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
The prevalence of obesity and metabolic diseases continues to rise, which has led to an increased interest in studying adipose tissue to elucidate underlying disease mechanisms. The use of genetic mouse models has been critical for understanding the role of specific genes for adipose tissue function and the tissue’s impact on other organs. However, mouse adipose tissue displays key differences to human fat, which has led, in some cases, to the emergence of some confounding concepts in the adipose field. Such differences include the depot-specific characteristics of visceral and subcutaneous fat, and divergences in thermogenic fat phenotype between the species. Adipose tissue characteristics may therefore not always be directly compared between species, which is important to consider when setting up new studies or interpreting results. This mini review outlines our current knowledge about the cell biological differences between human and mouse adipocytes and fat depots, highlighting some examples where inadequate knowledge of species-specific differences can lead to confounding results, and presenting plausible anatomic explanations that may underlie the differences. The article thus provides critical insights and guidance for researchers working primarily with only human or mouse fat tissue, and may contribute to new ideas or concepts in the important and evolving field of adipose biology.
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Affiliation(s)
- Emma Börgeson
- Department of Molecular and Clinical Medicine, Wallenberg Laboratory, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
- Region Vaestra Goetaland, Department of Clinical Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Jeremie Boucher
- The Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Metabolic Disease, Evotec International GmbH, Göttingen, Germany
| | - Carolina E. Hagberg
- Division of Cardiovascular Medicine, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- *Correspondence: Carolina E. Hagberg,
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12
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Fryklund C, Morén B, Neuhaus M, Periwal V, Stenkula KG. Rosiglitazone treatment enhances intracellular actin dynamics and glucose transport in hypertrophic adipocytes. Life Sci 2022; 299:120537. [PMID: 35398016 DOI: 10.1016/j.lfs.2022.120537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 03/28/2022] [Accepted: 04/02/2022] [Indexed: 10/18/2022]
Abstract
AIMS To accommodate surplus energy, adipose tissue expands by increasing both adipose cell size (hypertrophy) and cell number (hyperplasia). Enlarged, hypertrophic adipocytes are known to have reduced insulin response and impaired glucose transport, which negatively influence whole-body glucose homeostasis. Rosiglitazone is a peroxisome proliferator-activated receptor gamma (PPARγ) agonist, known to stimulate hyperplasia and to efficiently improve insulin sensitivity. Still, a limited amount of research has investigated the effects of rosiglitazone in mature, hypertrophic adipocytes. Therefore, the objective of this study was to examine rosiglitazone's effect on insulin-stimulated glucose uptake in hypertrophic adipocytes. MAIN METHODS C57BL/6J male mice were subjected to 2 weeks of high-fat diet (HFD) followed by 1 week of HFD combined with daily administration of rosiglitazone (10 mg/kg). Adipose cell-size distribution and gene expression were analysed in intact adipose tissue, and glucose uptake, insulin response, and protein expression were examined using primary adipocytes isolated from epididymal and inguinal adipose tissue. KEY FINDINGS HFD-feeding induced an accumulation of hypertrophic adipocytes, which was not affected by rosiglitazone-treatment. Still, rosiglitazone efficiently improved insulin-stimulated glucose transport without restoring insulin signaling or GLUT4 expression in similar-sized adipocytes. This improvement occurred concurrently with extracellular matrix remodelling and restored intracellular levels of targets involved in actin turnover. SIGNIFICANCE These results demonstrate that rosiglitazone improves glucose transport in hypertrophic adipocytes, and highlights the importance of the cytoskeleton and extracellular matrix as potential therapeutic targets.
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Affiliation(s)
- Claes Fryklund
- Department of Experimental Medical Science, Lund University, Sweden.
| | - Björn Morén
- Department of Experimental Medical Science, Lund University, Sweden
| | | | - Vipul Periwal
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, USA
| | - Karin G Stenkula
- Department of Experimental Medical Science, Lund University, Sweden
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13
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Pincu Y, Yoel U, Haim Y, Makarenkov N, Maixner N, Shaco-Levy R, Bashan N, Dicker D, Rudich A. Assessing Obesity-Related Adipose Tissue Disease (OrAD) to Improve Precision Medicine for Patients Living With Obesity. Front Endocrinol (Lausanne) 2022; 13:860799. [PMID: 35574032 PMCID: PMC9098964 DOI: 10.3389/fendo.2022.860799] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 03/15/2022] [Indexed: 12/21/2022] Open
Abstract
Obesity is a heterogenous condition that affects the life and health of patients to different degrees and in different ways. Yet, most approaches to treat obesity are not currently prescribed, at least in a systematic manner, based on individual obesity sub-phenotypes or specifically-predicted health risks. Adipose tissue is one of the most evidently affected tissues in obesity. The degree of adipose tissue changes - "adiposopathy", or as we propose to relate to herein as Obesity-related Adipose tissue Disease (OrAD), correspond, at least cross-sectionally, to the extent of obesity-related complications inflicted on an individual patient. This potentially provides an opportunity to better personalize anti-obesity management by utilizing the information that can be retrieved by assessing OrAD. This review article will summarize current knowledge on histopathological OrAD features which, beyond cross-sectional analyses, had been shown to predict future obesity-related endpoints and/or the response to specific anti-obesity interventions. In particular, the review explores adipocyte cell size, adipose tissue inflammation, and fibrosis. Rather than highly-specialized methods, we emphasize standard pathology laboratory approaches to assess OrAD, which are readily-available in most clinical settings. We then discuss how OrAD assessment can be streamlined in the obesity/weight-management clinic. We propose that current studies provide sufficient evidence to inspire concerted efforts to better explore the possibility of predicting obesity related clinical endpoints and response to interventions by histological OrAD assessment, in the quest to improve precision medicine in obesity.
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Affiliation(s)
- Yair Pincu
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
- Department of Health and Exercise Science, University of Oklahoma, Norman, OK, United States
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Uri Yoel
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
- The Endocrinology Service, Soroka University Medical Center, Beer-Sheva, Israel
| | - Yulia Haim
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
- The National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Nataly Makarenkov
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Nitzan Maixner
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Ruthy Shaco-Levy
- Institute of Pathology, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Nava Bashan
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Dror Dicker
- Department of Internal Medicine D, Hasharon Hospital, Rabin Medical Center, Petah Tikva, Israel
- Sackler School of Medicine, Tel Aviv University, Tel-Aviv, Israel
- *Correspondence: Assaf Rudich, ; Dror Dicker,
| | - Assaf Rudich
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel
- The National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- *Correspondence: Assaf Rudich, ; Dror Dicker,
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14
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Ghadiri MM, Hosseini SA, Sadatsakkak SA, Rajabpour A. Inertial microfluidics: Determining the effect of geometric key parameters on capture efficiency along with a feasibility evaluation for bone marrow cells sorting. Biomed Microdevices 2021; 23:41. [PMID: 34379212 DOI: 10.1007/s10544-021-00577-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2021] [Indexed: 11/29/2022]
Abstract
Despite great developments in inertial microfluidics, there is still a lack of knowledge to precisely define the particles' behavior in the microchannels. In the present study, as a prerequisite to experimental studies, numerical simulations have been used to study the capture efficiency of target particles in the contraction-expansion microchannel, aiming to provide an estimation of the conditions at which the channel performs best. Fluid analysis based on Navier-Stokes equations is conducted using the finite element method to determine the streamlines and vortices. The highest capture efficiency for 10, 15, and 19-micron particles occurs when the center of the vortex is approximately in the middle of the wide section (at the flow rate of 0.35 ml/min). In addition to investigating the effect of particle diameter and input flow rate, the effect of channel geometry parameters (channel height and initial length of the channel) on particle trapping has also been studied. Also, to consider great interest in separating different-sized bioparticles from a sample, a three-stage platform has been designed to separate four types of bone marrow cells and evaluate the possibility of using contraction-expansion channels in this application.
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Affiliation(s)
- Mohammad Mahdi Ghadiri
- Department of Mechanical Engineering, Imam Khomeini International University, Qazvin, Iran
| | - Seied Ali Hosseini
- Department of Electrical Engineering, Imam Khomeini International University, Qazvin, Iran.
| | | | - Ali Rajabpour
- Department of Mechanical Engineering, Imam Khomeini International University, Qazvin, Iran
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15
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Bosy-Westphal A, Müller MJ. Diagnosis of obesity based on body composition-associated health risks-Time for a change in paradigm. Obes Rev 2021; 22 Suppl 2:e13190. [PMID: 33480098 DOI: 10.1111/obr.13190] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/14/2022]
Abstract
Traditional diagnosis and understanding of the pathophysiology of obesity are based on excessive fat storage due to a chronically positive energy balance characterized by body mass index (BMI). Quantitative and qualitative analysis of lean and adipose tissue compartments by body composition analysis reveals that characterization of obesity as "overfat" does not facilitate a comprehensive understanding of obesity-associated health risk. Instead of being related to fat mass, body composition characteristics underlying BMI-associated prognosis may depend (i) on accelerated growth by a gain in lean mass or fat-free mass (FFM) in children with early BMI rebound or adolescents with early puberty; (ii) on a low muscle mass in aging, associated chronic disease, or severe illness; and (iii) on impaired adipose tissue expandability with respect to cardiometabolic risk. It is therefore time to call the adipocentric paradigm of obesity into question and to avoid the use of BMI and body fat percentage. By contrast, obesity should be seen in face of a limited FFM/muscle mass together with a limited capacity of fat storage.
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Affiliation(s)
- Anja Bosy-Westphal
- Institut für Humanernährung und Lebensmittelkunde, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Manfred J Müller
- Institut für Humanernährung und Lebensmittelkunde, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
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16
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Lesser Investigated Natural Ingredients for the Management of Obesity. Nutrients 2021; 13:nu13020510. [PMID: 33557185 PMCID: PMC7913945 DOI: 10.3390/nu13020510] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/30/2021] [Accepted: 01/31/2021] [Indexed: 12/13/2022] Open
Abstract
Obesity, an epidemiological disorder, is related to various complications in both the developed and developing world. It epitomizes a crucial risk factor for health, decreasing productivity and life expectancy while increasing health care costs worldwide. Conventional therapies with synthetic drugs or bariatric surgery, associated with numerous side effects, recurrence, and surgical complexity, have been restricted in their use. Lifestyle changes and dietary restrictions are the proven methods for successful weight loss, although maintaining a strict lifestyle is a challenge. Multiple natural products have been explored for weight management with varied efficacy. The current review explores less explored natural herbs, their active constituents, and their mechanisms of action against obesity.
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17
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Lipolytic and Lipophagic Effects of Pinellia ternata Pharmacopuncture on Localized Adiposity. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021; 2021:7347639. [PMID: 33505503 PMCID: PMC7806390 DOI: 10.1155/2021/7347639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 12/08/2020] [Accepted: 12/22/2020] [Indexed: 11/17/2022]
Abstract
Localized adiposity is not only a common aesthetic issue but also a health risk factor. Pharmacopuncture can be a therapeutic option for the imbalance of regional fat distribution. The tuber of Pinellia ternata has been prescribed as antitussive and expectorant as a traditional Korean medicine. This study investigated the effects of pharmacopuncture with P. ternata water extract (PT) on localized adiposity. Male C57BL/6J mice were fed on a high-fat diet (HFD) for 6 weeks. 100 μL of 10 mg/mL of PT was injected into the left-side inguinal fat pad, while saline was injected into the right-side inguinal fat pad as self-control. Treatments were performed 3 times per week for 4 weeks. The inguinal fat weight was analyzed by dual-energy X-ray absorptiometry. PT pharmacopuncture significantly decreased the weight of the inguinal fat pad. The adipocyte size was reduced with increases of lipolytic enzymes and lipophagy-related factors by PT pharmacopuncture. There was marked inhibition of lipid accumulation content in 3T3-L1 adipocytes by PT treatment. The expressions of adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), autophagy-related gene (ATG) 5, ATG7, and LC3 were markedly increased by PT treatments in vivo and in vitro. This study suggests that pharmacopuncture of Pinellia ternata has ameliorative effects on adiposity by lipid catabolic effects via activating both lipolysis and lipophagy in a localized region.
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18
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Liu F, He J, Wang H, Zhu D, Bi Y. Adipose Morphology: a Critical Factor in Regulation of Human Metabolic Diseases and Adipose Tissue Dysfunction. Obes Surg 2020; 30:5086-5100. [PMID: 33021706 PMCID: PMC7719100 DOI: 10.1007/s11695-020-04983-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 09/12/2020] [Accepted: 09/15/2020] [Indexed: 12/30/2022]
Abstract
Emerging evidence highlights that dysfunction of adipose tissue contributes to impaired insulin sensitivity and systemic metabolic deterioration in obese state. Of note, adipocyte hypertrophy serves as a critical event which associates closely with adipose dysfunction. An increase in cell size exacerbates hypoxia and inflammation as well as excessive collagen deposition, finally leading to metabolic dysregulation. Specific mechanisms of adipocyte hypertrophy include dysregulated differentiation and maturation of preadipocytes, enlargement of lipid droplets, and abnormal adipocyte osmolarity sensors. Also, weight loss therapies exert profound influence on adipocyte size. Here, we summarize the critical role of adipocyte hypertrophy in the development of metabolic disturbances. Future studies are required to establish a standard criterion of size measurement to better clarify the impact of adipocyte hypertrophy on changes in metabolic homeostasis.
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Affiliation(s)
- Fangcen Liu
- Department of Endocrinology, Nanjing Drum Tower Hospital Clinical College, Nanjing Medical University, Nanjing, China
| | - Jielei He
- Department of Endocrinology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Hongdong Wang
- Department of Endocrinology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Dalong Zhu
- Department of Endocrinology, Nanjing Drum Tower Hospital Clinical College, Nanjing Medical University, Nanjing, China
- Department of Endocrinology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Yan Bi
- Department of Endocrinology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China.
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19
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Leal-Gutiérrez JD, Elzo MA, Carr C, Mateescu RG. RNA-seq analysis identifies cytoskeletal structural genes and pathways for meat quality in beef. PLoS One 2020; 15:e0240895. [PMID: 33175867 PMCID: PMC7657496 DOI: 10.1371/journal.pone.0240895] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 10/05/2020] [Indexed: 01/03/2023] Open
Abstract
RNA sequencing (RNA-seq) has allowed for transcriptional profiling of biological systems through the identification of differentially expressed (DE) genes and pathways. A total of 80 steers with extreme phenotypes were selected from the University of Florida multibreed Angus-Brahman herd. The average slaughter age was 12.91±8.69 months. Tenderness, juiciness and connective tissue assessed by sensory panel, along with marbling, Warner-Bratzler Shear Force (WBSF) and cooking loss, were measured in longissimus dorsi muscle. Total RNA was extracted from muscle and one RNA-seq library per sample was constructed, multiplexed, and sequenced based on protocols by Illumina HiSeq-3000 platform to generate 2×101 bp paired-end reads. The overall read mapping rate using the Btau_4.6.1 reference genome was 63%. A total of 8,799 genes were analyzed using two different methodologies, an expression association and a DE analysis. A gene and exon expression association analysis was carried out using a meat quality index on all 80 samples as a continuous response variable. The expression of 208 genes and 3,280 exons from 1,565 genes was associated with the meat quality index (p-value ≤ 0.05). A gene and isoform DE evaluation was performed analyzing two groups with extreme WBSF, tenderness and marbling. A total of 676 (adjusted p-value≤0.05), 70 (adjusted p-value≤0.1) and 198 (adjusted p-value≤0.1) genes were DE for WBSF, tenderness and marbling, respectively. A total of 106 isoforms from 98 genes for WBSF, 13 isoforms from 13 genes for tenderness and 43 isoforms from 42 genes for marbling (FDR≤0.1) were DE. Cytoskeletal and transmembrane anchoring genes and pathways were identified in the expression association, DE and the gene enrichment analyses; these proteins can have a direct effect on meat quality. Cytoskeletal proteins and transmembrane anchoring molecules can influence meat quality by allowing cytoskeletal interaction with myocyte and organelle membranes, contributing to cytoskeletal structure and architecture maintenance postmortem.
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Affiliation(s)
- Joel D. Leal-Gutiérrez
- Department of Animal Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Mauricio A. Elzo
- Department of Animal Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Chad Carr
- Department of Animal Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Raluca G. Mateescu
- Department of Animal Sciences, University of Florida, Gainesville, Florida, United States of America
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20
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Aprile M, Cataldi S, Perfetto C, Ambrosio MR, Italiani P, Tatè R, Blüher M, Ciccodicola A, Costa V. In-Vitro-Generated Hypertrophic-Like Adipocytes Displaying PPARG Isoforms Unbalance Recapitulate Adipocyte Dysfunctions In Vivo. Cells 2020; 9:cells9051284. [PMID: 32455814 PMCID: PMC7290899 DOI: 10.3390/cells9051284] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 12/30/2022] Open
Abstract
Reduced neo-adipogenesis and dysfunctional lipid-overloaded adipocytes are hallmarks of hypertrophic obesity linked to insulin resistance. Identifying molecular features of hypertrophic adipocytes requires appropriate in vitro models. We describe the generation of a model of human hypertrophic-like adipocytes directly comparable to normal adipose cells and the pathologic evolution toward hypertrophic state. We generate in vitro hypertrophic cells from mature adipocytes, differentiated from human mesenchymal stem cells. Combining optical, confocal, and transmission electron microscopy with mRNA/protein quantification, we characterize this cellular model, confirming specific alterations also in subcutaneous adipose tissue. Specifically, we report the generation and morphological/molecular characterization of human normal and hypertrophic-like adipocytes. The latter displays altered morphology and unbalance between canonical and dominant negative (PPARGΔ5) transcripts of PPARG, paralleled by reduced expression of PPARγ targets, including GLUT4. Furthermore, the unbalance of PPARγ isoforms associates with GLUT4 down-regulation in subcutaneous adipose tissue of individuals with overweight/obesity or impaired glucose tolerance/type 2 diabetes, but not with normal weight or glucose tolerance. In conclusion, the hypertrophic-like cells described herein are an innovative tool for studying molecular dysfunctions in hypertrophic obesity and the unbalance between PPARγ isoforms associates with down-regulation of GLUT4 and other PPARγ targets, representing a new hallmark of hypertrophic adipocytes.
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Affiliation(s)
- Marianna Aprile
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso,” CNR, Via P. Castellino 111, 80131 Naples, Italy; (S.C.); (C.P.); (R.T.); (A.C.)
- Correspondence: (M.A.); (V.C.)
| | - Simona Cataldi
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso,” CNR, Via P. Castellino 111, 80131 Naples, Italy; (S.C.); (C.P.); (R.T.); (A.C.)
| | - Caterina Perfetto
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso,” CNR, Via P. Castellino 111, 80131 Naples, Italy; (S.C.); (C.P.); (R.T.); (A.C.)
| | - Maria Rosaria Ambrosio
- Department of Translational Medicine, University of Naples “Federico II” & URT “Genomic of Diabetes,” Institute of Experimental Endocrinology and Oncology “G. Salvatore,” CNR, Via Pansini 5, 80131 Naples, Italy;
| | - Paola Italiani
- Institute of Biochemistry and Cell Biology CNR, Via P. Castellino 111, 80131 Naples, Italy;
| | - Rosarita Tatè
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso,” CNR, Via P. Castellino 111, 80131 Naples, Italy; (S.C.); (C.P.); (R.T.); (A.C.)
| | - Matthias Blüher
- Department of Medicine, University of Leipzig, 4289 Leipzig, Germany;
| | - Alfredo Ciccodicola
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso,” CNR, Via P. Castellino 111, 80131 Naples, Italy; (S.C.); (C.P.); (R.T.); (A.C.)
- Department of Science and Technology, University of Naples “Parthenope,” 80131 Naples, Italy
| | - Valerio Costa
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso,” CNR, Via P. Castellino 111, 80131 Naples, Italy; (S.C.); (C.P.); (R.T.); (A.C.)
- Correspondence: (M.A.); (V.C.)
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21
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He ML, Stanford K, Dugan MER, Marquess L, McAllister TA. Association of leptin genotype with growth performance, adipocyte cellularity, meat quality, and fatty acid profile in beef steers fed flaxseed or high-oleate sunflower seed diets with or without triticale dried distiller's grains. J Anim Sci 2020; 98:skaa104. [PMID: 32277699 PMCID: PMC7185023 DOI: 10.1093/jas/skaa104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 04/09/2020] [Indexed: 12/30/2022] Open
Abstract
Leptin genotypes can be identified as homozygous normal (CC), homozygous mutant (TT), and heterozygous (CT) based on a single-nucleotide polymorphism in exon 2 of the leptin gene, which has been associated with feed intake and fat deposition in cattle. The experiment was designed as 2 × 2 × 2 factorial with three main factors: (1) genotype (CT or TT) and diets fed 2) with or without triticale dried distiller's grains with solubles (DDG), and 3) with either flaxseed (FS) or high-oleate sunflower seed (SS). Evaluations included growth performance, subcutaneous fat deposition, adipocyte cellularity, meat quality, and fatty acid (FA) profile of various depots. Beef steers (n = 40, 459 ± 31 kg) of either CT or TT genotypes were housed in individual pens with ad libitum access to one of the four diets: 75% steam-rolled barley + 10% barley silage with 10% FS or SS (non-DDG diets, NDG) and 46.5% barley + 10% barley silage + 30% DDG, with 8.5% FS or SS, all on a dry matter basis. Growth performance, ultrasound subcutaneous fat thickness, rib eye area (REA), and plasma FA were measured prior to and during the finishing period. At slaughter, samples of subcutaneous fat, perirenal fat, and Longissimus thoracis (LT) muscle were collected for FA analysis and carcass and meat quality were measured. Compared with CT cattle, TT tended to have less (P = 0.06) C18:2-c9,t11 (rumenic acid) in plasma and subcutaneous fat and a greater proportion (P < 0.05) of C18:0 in subcutaneous, perirenal, and LT fat. Cattle with TT genotype also tended (P < 0.1) to have more total saturated and less unsaturated (USFA) and monounsaturated fats (MUFA) and had less (P = 0.04) linoleic acid in LT. Ultrasound fat thickness, REA, and average diameter of adipocytes in subcutaneous fat at 12 wk were not affected (P > 0.39) by genotype. Generally, carcass and meat quality were similar (P > 0.1) among diets, although adding FS tended to increase (P = 0.06) total USFA of subcutaneous fat including omega-3 FA (P < 0.001). For the high-fat diets evaluated, CT cattle would have more potential to produce beef with enhanced health benefits than would TT cattle.
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Affiliation(s)
- Maolong L He
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Canada
| | - Kim Stanford
- Agriculture Centre, Alberta Agriculture and Forestry, Lethbridge, Canada
| | - Michael E R Dugan
- Lacombe Research and Development Centre, Agriculture and Agri-Food Canada, Lacombe, Canada
| | | | - Tim A McAllister
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Canada
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22
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Short-Term Responses to Fatty Acids on Lipid Metabolism and Adipogenesis in Rainbow Trout ( Oncorhynchus mykiss). Int J Mol Sci 2020; 21:ijms21051623. [PMID: 32120851 PMCID: PMC7084833 DOI: 10.3390/ijms21051623] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/14/2020] [Accepted: 02/21/2020] [Indexed: 01/06/2023] Open
Abstract
Fish are rich in n-3 long-chain polyunsaturated fatty acids (LC-PUFA) such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Due to the increasing use of vegetable oils (VO), their proportion in diets has lowered, affecting lipid metabolism and fillet composition. Rainbow trout cultured preadipocytes were treated with representative FA found in fish oils (EPA and DHA) or VO (linoleic, LA and alpha-linolenic, ALA acids), while EPA and LA were also orally administered, to evaluate their effects on adipogenesis and lipid metabolism. In vitro, all FA increased lipid internalization, with ALA producing the highest effect, together with upregulating the FA transporter fatp1. In vivo, EPA or LA increased peroxisome proliferator-activated receptors ppara and pparb transcripts abundance in adipose tissue, suggesting elevated β-oxidation, contrary to the results obtained in liver. Furthermore, the increased expression of FA synthase (fas) and the FA translocase/cluster of differentiation (cd36) in adipose tissue indicated an enhanced uptake of lipids and lipogenesis de novo, whereas stable or low hepatic expression of genes involved in lipid transport and turnover was found. Thus, fish showed a similar tissue metabolic response to the short-term availability of EPA or LA in vivo, while in vitro VO-derived FA demonstrated greater potential inducing fat accumulation.
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23
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Gunasekar SK, Xie L, Sah R. SWELL signalling in adipocytes: can fat 'feel' fat? Adipocyte 2019; 8:223-228. [PMID: 31112068 PMCID: PMC6768237 DOI: 10.1080/21623945.2019.1612223] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/18/2019] [Accepted: 04/19/2019] [Indexed: 01/04/2023] Open
Abstract
Obesity is becoming a global epidemic, predisposing to Type 2 diabetes, cardiovascular disease, fatty liver disease, pulmonary disease, osteoarthritis and cancer. Therefore, understanding the biology of adipocyte expansion in response to overnutrition is critical to devising strategies to treat obesity, and the associated burden of morbidity and mortality. Through exploratory patch-clamp experiments in freshly isolated primary murine and human adipocytes, we recently determined that SWELL1/LRRC8a, a leucine-rich repeat containing transmembrane protein, functionally encoded an ion channel signalling complex (the volume-regulated anion channel, or VRAC) on the adipocyte plasma membrane. The SWELL1-/LRRC8 channel complex activates in response to increases in adipocyte volume and in the context of obesity. SWELL1 is also required for insulin-PI3K-AKT2 signalling to regulate adipocyte growth and systemic glycaemia. This commentary delves further into our working models for the molecular mechanisms of adipocyte SWELL1-mediated VRAC activation, proposed signal transduction mechanisms, and putative impact on adipocyte hypertrophy during caloric excess.
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Affiliation(s)
- Susheel K. Gunasekar
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, MO, USA
| | - Litao Xie
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, MO, USA
| | - Rajan Sah
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, MO, USA
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24
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Ma J, Xia M D J, Gao J, Lu F, Liao Y. Mechanical Signals Induce Dedifferentiation of Mature Adipocytes and Increase the Retention Rate of Fat Grafts. Plast Reconstr Surg 2019; 144:1323-1333. [PMID: 31764645 DOI: 10.1097/prs.0000000000006272] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Mature adipocytes dedifferentiate in vivo on application of a soft-tissue expander. Dedifferentiated adipocytes can proliferate and redifferentiate. This study used tissue expanders to pretreat adipose flaps, to increase the retention rate after fat graft. METHODS A soft-tissue expander and silicone sheet were implanted beneath the left and right inguinal fat pads of rats, respectively. After 7 days of expansion, the adipose tissue derived from the pads was transplanted beneath dorsal skin. Samples were harvested at various time points, and histologic, immunohistochemical, and gene expression analyses were conducted. Mature adipocytes were cultured in vitro under a pressure of 520 Pa. Changes in cell morphology, the cytoskeleton, and expression of mechanical signal-related proteins were investigated. RESULTS Pressure in adipose flaps increased to 25 kPa on expansion. Mature adipocytes dedifferentiated following expansion. At 1 week after transplantation, the expression of vascular endothelial growth factor (p < 0.05) was higher in the expanded group. The retention rate at 12 weeks after transplantation was higher in the expanded group (56 ± 3 percent) than in the control group (32 ± 3 percent) (p < 0.05), and the surviving/regenerating zones (p < 0.01) were wider. The lipid content of mature adipocytes gradually decreased on culture under increased pressure, and these cells regained a proliferative capacity. This was accompanied by increased expression of mechanical signal--related proteins (p < 0.05). CONCLUSIONS Mechanical signals may induce dedifferentiation of mature adipocytes. Dedifferentiated adipocytes increase the retention rate of fat grafts by acting as seed cells.
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Affiliation(s)
- Jingjing Ma
- From the Department of Plastic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University; and the Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University
| | - Jing Xia M D
- From the Department of Plastic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University; and the Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University
| | - Jianhua Gao
- From the Department of Plastic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University; and the Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University
| | - Feng Lu
- From the Department of Plastic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University; and the Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University
| | - Yunjun Liao
- From the Department of Plastic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University; and the Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University
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25
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Expression analysis of CEBPA and its antisense RNA revealed their dysregulation in peripheral blood of coronary artery disease patients. GENE REPORTS 2019. [DOI: 10.1016/j.genrep.2019.100466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Malekpour-Dehkordi Z, Teimourian S, Nourbakhsh M, Naghiaee Y, Sharifi R, Mohiti-Ardakani J. Metformin reduces fibrosis factors in insulin resistant and hypertrophied adipocyte via integrin/ERK, collagen VI, apoptosis, and necrosis reduction. Life Sci 2019; 233:116682. [DOI: 10.1016/j.lfs.2019.116682] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/21/2019] [Accepted: 07/22/2019] [Indexed: 12/12/2022]
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27
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Fang Z, Pyne S, Pyne NJ. WITHDRAWN: Ceramide and Sphingosine 1-Phosphate in adipose dysfunction. Prog Lipid Res 2019:100991. [PMID: 31442525 DOI: 10.1016/j.plipres.2019.100991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/21/2019] [Accepted: 04/01/2019] [Indexed: 11/18/2022]
Affiliation(s)
- Zijian Fang
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161, Cathedral St, Glasgow, G4 0RE, Scotland, UK
| | - Susan Pyne
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161, Cathedral St, Glasgow, G4 0RE, Scotland, UK
| | - Nigel J Pyne
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161, Cathedral St, Glasgow, G4 0RE, Scotland, UK
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28
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Chin YX, Mi Y, Cao WX, Lim PE, Xue CH, Tang QJ. A Pilot Study on Anti-Obesity Mechanisms of Kappaphycus Alvarezii: The Role of Native κ-Carrageenan and the Leftover Sans-Carrageenan Fraction. Nutrients 2019; 11:E1133. [PMID: 31117266 PMCID: PMC6566674 DOI: 10.3390/nu11051133] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 05/10/2019] [Accepted: 05/17/2019] [Indexed: 12/15/2022] Open
Abstract
Kappaphycus is a commercially important edible red alga widely cultivated for carrageenan production. Here, we aimed to investigate the anti-obesity mechanism of Kappaphycus alvarezii by comparing the effects of whole seaweed (T), extracted native κ-carrageenan (CGN), and the leftover fraction sans-carrageenan (SCGN) supplementations (5%, w/w) on diet-induced obese C57BL/6J mice. A high-fat diet induced both a raised body fat percentage and serum cholesterol level, increased adipocytes size, abnormal levels of adipocytokines, and promoted gut dysbiosis. Our results showed that, overall, both CGN and SCGN were more effective in reversing obesity and related metabolic syndromes to normal levels than T. Furthermore, these findings suggested that CGN- and SCGN-modulated gut dysbiosis induced by a high-fat diet, which may play an influencing role in adiponectin dysregulation. Our data also showed some evidence that CGN and SCGN have distinct effects on selected genes involved in lipid metabolism. In conclusion, both κ-carrageenan and SCGN have novel anti-obesity potential with possible different mechanisms of action.
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Affiliation(s)
- Yao Xian Chin
- Human Health Research Laboratory, College of Food Science and Engineering, University of China, Qingdao 266003, Shandong, China.
| | - Ye Mi
- Human Health Research Laboratory, College of Food Science and Engineering, University of China, Qingdao 266003, Shandong, China.
| | - Wan Xiu Cao
- Human Health Research Laboratory, College of Food Science and Engineering, University of China, Qingdao 266003, Shandong, China.
| | - Phaik Eem Lim
- Institute of Ocean and Earth Sciences, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Chang Hu Xue
- Human Health Research Laboratory, College of Food Science and Engineering, University of China, Qingdao 266003, Shandong, China.
| | - Qing Juan Tang
- Human Health Research Laboratory, College of Food Science and Engineering, University of China, Qingdao 266003, Shandong, China.
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29
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Ceramide and sphingosine 1-phosphate in adipose dysfunction. Prog Lipid Res 2019; 74:145-159. [PMID: 30951736 DOI: 10.1016/j.plipres.2019.04.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/21/2019] [Accepted: 04/01/2019] [Indexed: 12/17/2022]
Abstract
The increased adipose tissue mass of obese individuals enhances the risk of metabolic syndrome, type 2 diabetes and cardiovascular diseases. During pathological expansion of adipose tissue, multiple molecular controls of lipid storage, adipocyte turn-over and endocrine secretion are perturbed and abnormal lipid metabolism results in a distinct lipid profile. There is a role for ceramides and sphingosine 1-phosphate (S1P) in inducing adipose dysfunction. For instance, the alteration of ceramide biosynthesis, through the de-regulation of key enzymes, results in aberrant formation of ceramides (e.g. C16:0 and C18:0) which block insulin signaling and promote adipose inflammation. Furthermore, S1P can induce defective adipose tissue phenotypes by promoting chronic inflammation and inhibiting adipogenesis. These abnormal changes are discussed in the context of possible therapeutic approaches to re-establish normal adipose function and to, thereby, increase insulin sensitivity in type 2 diabetes. Such novel approaches include blockade of ceramide biosynthesis using inhibitors of sphingomyelinase or dihydroceramide desaturase and by antagonism of S1P receptors, such as S1P2.
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30
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Liu Y, Kongsuphol P, Chiam SY, Zhang QX, Gourikutty SBN, Saha S, Biswas SK, Ramadan Q. Adipose-on-a-chip: a dynamic microphysiological in vitro model of the human adipose for immune-metabolic analysis in type II diabetes. LAB ON A CHIP 2019; 19:241-253. [PMID: 30566152 DOI: 10.1039/c8lc00481a] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Infiltration of immune cells into adipose tissue is associated with chronic low-grade inflammation in obese individuals. To better understand the crosstalk between immune cells and adipocytes, in vivo-like in vitro models are required. Conventionally transwell culture plates are used for studying the adipocyte-immune cell interaction; however, the static culture nature of this approach falls short of closely recapitulating the physiological environment. Here we present a compartmentalized microfluidic co-culture system which provides a constant-rate of nutrient supply as well as waste removal, resembling the microvascular networks of the in vivo environment. Human adipocytes and U937 cells were co-cultured in close proximity in an enclosed system. The porous barrier between the adjacent compartments comprises an array of microchannels, which enables paracrine interaction between cells in adjacent compartments and improved perfusion-based long term cell feeding. Human pre-adipocytes were fully differentiated into adipocytes on the chip and remained viable for several weeks. Upon co-culturing with immune cells, adipocytes showed a tendency to develop insulin resistance. The immune-metabolic correlation has been studied by monitoring adiponectin and IL-6 expression, as well as glucose uptake upon treatment with insulin. Our microfluidic system can be potentially used to develop physiologically relevant adipose tissue models to study obesity-associated diseases such as insulin resistance and type 2 diabetes and therefore, facilitate drug development to treat these diseases.
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Affiliation(s)
- Yunxiao Liu
- Institute of Microelectronic, A* STAR (Agency for Science, Technology and Research), 2, Fusionopolis Way, #08-02, Innovis Tower, 138635 Singapore.
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31
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Leal-Gutiérrez JD, Rezende FM, Elzo MA, Johnson D, Peñagaricano F, Mateescu RG. Structural Equation Modeling and Whole-Genome Scans Uncover Chromosome Regions and Enriched Pathways for Carcass and Meat Quality in Beef. Front Genet 2018; 9:532. [PMID: 30555508 PMCID: PMC6282042 DOI: 10.3389/fgene.2018.00532] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 10/22/2018] [Indexed: 12/11/2022] Open
Abstract
Structural equation models involving latent variables are useful tools for formulating hypothesized models defined by theoretical variables and causal links between these variables. The objectives of this study were: (1) to identify latent variables underlying carcass and meat quality traits and (2) to perform whole-genome scans for these latent variables in order to identify genomic regions and individual genes with both direct and indirect effects. A total of 726 steers from an Angus-Brahman multibreed population with records for 22 phenotypes were used. A total of 480 animals were genotyped with the GGP Bovine F-250. The single-step genomic best linear unbiased prediction method was used to estimate the amount of genetic variance explained for each latent variable by chromosome regions of 20 adjacent SNP-windows across the genome. Three types of genetic effects were considered: (1) direct effects on a single latent phenotype; (2) direct effects on two latent phenotypes simultaneously; and (3) indirect effects. The final structural model included carcass quality as an independent latent variable and meat quality as a dependent latent variable. Carcass quality was defined by quality grade, fat over the ribeye and marbling, while the meat quality was described by juiciness, tenderness and connective tissue, all of them measured through a taste panel. From 571 associated genomic regions (643 genes), each one explaining at least 0.05% of the additive variance, 159 regions (179 genes) were associated with carcass quality, 106 regions (114 genes) were associated with both carcass and meat quality, 242 regions (266 genes) were associated with meat quality, and 64 regions (84 genes) were associated with carcass quality, having an indirect effect on meat quality. Three biological mechanisms emerged from these findings: postmortem proteolysis of structural proteins and cellular compartmentalization, cellular proliferation and differentiation of adipocytes, and fat deposition.
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Affiliation(s)
| | - Fernanda M. Rezende
- Department of Animal Sciences, University of Florida, Gainesville, FL, United States
- Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Mauricio A. Elzo
- Department of Animal Sciences, University of Florida, Gainesville, FL, United States
| | - Dwain Johnson
- Department of Animal Sciences, University of Florida, Gainesville, FL, United States
| | - Francisco Peñagaricano
- Department of Animal Sciences, University of Florida, Gainesville, FL, United States
- University of Florida Genetics Institute, University of Florida, Gainesville, FL, United States
| | - Raluca G. Mateescu
- Department of Animal Sciences, University of Florida, Gainesville, FL, United States
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32
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Abstract
At the simplest level, obesity is the manifestation of an imbalance between caloric intake and expenditure; however, the pathophysiological mechanisms that govern the development of obesity and associated complications are enormously complex. Fibrosis within the adipose tissue compartment is one such factor that may influence the development of obesity and/or obesity-related comorbidities. Furthermore, the functional consequences of adipose tissue fibrosis are a matter of considerable debate, with evidence that fibrosis serves both adaptive and maladaptive roles. Tissue fibrosis itself is incompletely understood, and multiple cellular and molecular pathways are involved in the development, maintenance, and resolution of the fibrotic state. Within the context of obesity, fibrosis influences molecular and cellular events that relate to adipocytes, inflammatory cells, inflammatory mediators, and supporting adipose stromal tissue. In this Review, we explore what is known about the interplay between the development of adipose tissue fibrosis and obesity, with a view toward future investigative and therapeutic avenues.
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Affiliation(s)
| | - Michael J Podolsky
- Cardiovascular Research Institute.,Lung Biology Center, and.,Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Kamran Atabai
- Cardiovascular Research Institute.,Lung Biology Center, and.,Department of Medicine, University of California, San Francisco, San Francisco, California, USA
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33
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Graja A, Garcia-Carrizo F, Jank AM, Gohlke S, Ambrosi TH, Jonas W, Ussar S, Kern M, Schürmann A, Aleksandrova K, Blüher M, Schulz TJ. Loss of periostin occurs in aging adipose tissue of mice and its genetic ablation impairs adipose tissue lipid metabolism. Aging Cell 2018; 17:e12810. [PMID: 30088333 PMCID: PMC6156450 DOI: 10.1111/acel.12810] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 06/01/2018] [Accepted: 06/10/2018] [Indexed: 12/22/2022] Open
Abstract
Remodeling of the extracellular matrix is a key component of the metabolic adaptations of adipose tissue in response to dietary and physiological challenges. Disruption of its integrity is a well-known aspect of adipose tissue dysfunction, for instance, during aging and obesity. Adipocyte regeneration from a tissue-resident pool of mesenchymal stem cells is part of normal tissue homeostasis. Among the pathophysiological consequences of adipogenic stem cell aging, characteristic changes in the secretory phenotype, which includes matrix-modifying proteins, have been described. Here, we show that the expression of the matricellular protein periostin, a component of the extracellular matrix produced and secreted by adipose tissue-resident interstitial cells, is markedly decreased in aged brown and white adipose tissue depots. Using a mouse model, we demonstrate that the adaptation of adipose tissue to adrenergic stimulation and high-fat diet feeding is impaired in animals with systemic ablation of the gene encoding for periostin. Our data suggest that loss of periostin attenuates lipid metabolism in adipose tissue, thus recapitulating one aspect of age-related metabolic dysfunction. In human white adipose tissue, periostin expression showed an unexpected positive correlation with age of study participants. This correlation, however, was no longer evident after adjusting for BMI or plasma lipid and liver function biomarkers. These findings taken together suggest that age-related alterations of the adipose tissue extracellular matrix may contribute to the development of metabolic disease by negatively affecting nutrient homeostasis.
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Affiliation(s)
- Antonia Graja
- Department of Adipocyte Development and Nutrition; German Institute of Human Nutrition; Potsdam-Rehbrücke Germany
- University of Potsdam, Institute of Nutritional Science; Potsdam-Rehbrücke Germany
| | - Francisco Garcia-Carrizo
- Department of Adipocyte Development and Nutrition; German Institute of Human Nutrition; Potsdam-Rehbrücke Germany
| | - Anne-Marie Jank
- Department of Adipocyte Development and Nutrition; German Institute of Human Nutrition; Potsdam-Rehbrücke Germany
| | - Sabrina Gohlke
- Department of Adipocyte Development and Nutrition; German Institute of Human Nutrition; Potsdam-Rehbrücke Germany
| | - Thomas H. Ambrosi
- Department of Adipocyte Development and Nutrition; German Institute of Human Nutrition; Potsdam-Rehbrücke Germany
| | - Wenke Jonas
- Department of Experimental Diabetology; German Institute of Human Nutrition; Potsdam-Rehbrücke Germany
- German Center for Diabetes Research (DZD); Munich-Neuherberg Germany
| | - Siegfried Ussar
- German Center for Diabetes Research (DZD); Munich-Neuherberg Germany
- JRG Adipocytes and Metabolism; Institute for Diabetes and Obesity; Helmholtz Center Munich; Garching Germany
| | - Matthias Kern
- Department of Medicine; University of Leipzig; Leipzig Germany
| | - Annette Schürmann
- University of Potsdam, Institute of Nutritional Science; Potsdam-Rehbrücke Germany
- Department of Experimental Diabetology; German Institute of Human Nutrition; Potsdam-Rehbrücke Germany
- German Center for Diabetes Research (DZD); Munich-Neuherberg Germany
| | - Krasimira Aleksandrova
- University of Potsdam, Institute of Nutritional Science; Potsdam-Rehbrücke Germany
- Nutrition, Immunity and Metabolism Senior Scientist Group; German Institute of Human Nutrition; Potsdam-Rehbrücke Germany
| | - Matthias Blüher
- Department of Medicine; University of Leipzig; Leipzig Germany
| | - Tim J. Schulz
- Department of Adipocyte Development and Nutrition; German Institute of Human Nutrition; Potsdam-Rehbrücke Germany
- University of Potsdam, Institute of Nutritional Science; Potsdam-Rehbrücke Germany
- German Center for Diabetes Research (DZD); Munich-Neuherberg Germany
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34
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Stenkula KG, Erlanson-Albertsson C. Adipose cell size: importance in health and disease. Am J Physiol Regul Integr Comp Physiol 2018; 315:R284-R295. [DOI: 10.1152/ajpregu.00257.2017] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Adipose tissue is necessary to harbor energy. To handle excess energy, adipose tissue expands by increasing adipocyte size (hypertrophy) and number (hyperplasia). Here, we have summarized the different experimental techniques used to study adipocyte cell size and describe adipocyte size in relation to insulin resistance, type 2 diabetes, and diet interventions. Hypertrophic adipocytes have an impaired cellular function, and inherent mechanisms restrict their expansion to protect against cell breakage and subsequent inflammation. Reduction of large fat cells by diet restriction, physical activity, or bariatric surgery therefore is necessary to improve cellular function and health. Small fat cells may also be dysfunctional and unable to expand. The distribution and function of the entire cell size range of fat cells, from small to very large fat cells, are an important but understudied aspect of adipose tissue biology. To prevent dysmetabolism, therapeutic strategies to expand small fat cells, recruit new fat cells, and reduce large fat cells are needed.
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Affiliation(s)
- Karin G. Stenkula
- Glucose Transport and Protein Trafficking, Biomedical Center, Lund University, Lund, Sweden
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35
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Antonopoulos AS, Sanna F, Sabharwal N, Thomas S, Oikonomou EK, Herdman L, Margaritis M, Shirodaria C, Kampoli AM, Akoumianakis I, Petrou M, Sayeed R, Krasopoulos G, Psarros C, Ciccone P, Brophy CM, Digby J, Kelion A, Uberoi R, Anthony S, Alexopoulos N, Tousoulis D, Achenbach S, Neubauer S, Channon KM, Antoniades C. Detecting human coronary inflammation by imaging perivascular fat. Sci Transl Med 2018; 9:9/398/eaal2658. [PMID: 28701474 DOI: 10.1126/scitranslmed.aal2658] [Citation(s) in RCA: 561] [Impact Index Per Article: 93.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/30/2017] [Accepted: 05/30/2017] [Indexed: 12/11/2022]
Abstract
Early detection of vascular inflammation would allow deployment of targeted strategies for the prevention or treatment of multiple disease states. Because vascular inflammation is not detectable with commonly used imaging modalities, we hypothesized that phenotypic changes in perivascular adipose tissue (PVAT) induced by vascular inflammation could be quantified using a new computerized tomography (CT) angiography methodology. We show that inflamed human vessels release cytokines that prevent lipid accumulation in PVAT-derived preadipocytes in vitro, ex vivo, and in vivo. We developed a three-dimensional PVAT analysis method and studied CT images of human adipose tissue explants from 453 patients undergoing cardiac surgery, relating the ex vivo images with in vivo CT scan information on the biology of the explants. We developed an imaging metric, the CT fat attenuation index (FAI), that describes adipocyte lipid content and size. The FAI has excellent sensitivity and specificity for detecting tissue inflammation as assessed by tissue uptake of 18F-fluorodeoxyglucose in positron emission tomography. In a validation cohort of 273 subjects, the FAI gradient around human coronary arteries identified early subclinical coronary artery disease in vivo, as well as detected dynamic changes of PVAT in response to variations of vascular inflammation, and inflamed, vulnerable atherosclerotic plaques during acute coronary syndromes. Our study revealed that human vessels exert paracrine effects on the surrounding PVAT, affecting local intracellular lipid accumulation in preadipocytes, which can be monitored using a CT imaging approach. This methodology can be implemented in clinical practice to noninvasively detect plaque instability in the human coronary vasculature.
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Affiliation(s)
- Alexios S Antonopoulos
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Fabio Sanna
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Nikant Sabharwal
- Cardiothoracic Directorate, Oxford University Hospitals National Health System (NHS) Foundation Trust, Oxford, UK
| | - Sheena Thomas
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Evangelos K Oikonomou
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Laura Herdman
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Marios Margaritis
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,Oxford Centre of Research Excellence, British Heart Foundation, Oxford, UK
| | - Cheerag Shirodaria
- Cardiothoracic Directorate, Oxford University Hospitals National Health System (NHS) Foundation Trust, Oxford, UK
| | - Anna-Maria Kampoli
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Ioannis Akoumianakis
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Mario Petrou
- Department of Cardiothoracic Surgery, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Rana Sayeed
- Department of Cardiothoracic Surgery, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - George Krasopoulos
- Department of Cardiothoracic Surgery, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Constantinos Psarros
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Patricia Ciccone
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Carl M Brophy
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Janet Digby
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Andrew Kelion
- Cardiothoracic Directorate, Oxford University Hospitals National Health System (NHS) Foundation Trust, Oxford, UK
| | - Raman Uberoi
- Department of Radiology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Suzan Anthony
- Department of Radiology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | | | - Dimitris Tousoulis
- 1st Department of Cardiology, Athens University Medical School, Athens, Greece
| | - Stephan Achenbach
- Medizinische Klinik 2, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Stefan Neubauer
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,Oxford Centre of Research Excellence, British Heart Foundation, Oxford, UK.,Oxford Biomedical Research Centre, National Institute of Health Research, Oxford, UK
| | - Keith M Channon
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,Oxford Centre of Research Excellence, British Heart Foundation, Oxford, UK.,Oxford Biomedical Research Centre, National Institute of Health Research, Oxford, UK
| | - Charalambos Antoniades
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK. .,Oxford Centre of Research Excellence, British Heart Foundation, Oxford, UK.,Oxford Biomedical Research Centre, National Institute of Health Research, Oxford, UK
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36
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El Hachmane MF, Olofsson CS. A mechanically activated TRPC1-like current in white adipocytes. Biochem Biophys Res Commun 2018. [PMID: 29524421 DOI: 10.1016/j.bbrc.2018.03.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ca2+ impacts a large array of cellular processes in every known cell type. In the white adipocyte, Ca2+ is involved in regulation of metabolic processes such as lipolysis, glucose uptake and hormone secretion. Although the importance of Ca2+ in control of white adipocyte function is clear, knowledge is still lacking regarding the control of dynamic Ca2+ alterations within adipocytes and mechanisms inducing intracellular Ca2+ changes remain elusive. Own work has recently demonstrated the existence of store-operated Ca2+ entry (SOCE) in lipid filled adipocytes. We defined stromal interaction molecule 1 (STIM1) and the calcium release-activated calcium channel protein 1 (ORAI1) as the key players involved in this process and we showed that the transient receptor potential (TRP) channel TRPC1 contributed to SOCE. Here we have aimed to further characterised SOCE in the white adipocyte by use of single cell whole-cell patch clamp recordings. The electrophysiological measurements show the existence of a seemingly constitutively active current that is inhibited by known store-operated Ca2+ channel (SOCC) blockers. We demonstrate that the mechanical force applied to the plasma membrane upon patching leads to an elevation of the cytoplasmic Ca2+ concentration and that this elevation can be reversed by SOCC antagonists. We conclude that a mechanically activated current with properties similar to TRPC1 is present in white adipocytes. Activation of TRPC1 by membrane tension/stretch may be specifically important for the function of this cell type, since adipocytes can rapidly increase or decrease in size.
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Affiliation(s)
- Mickaël F El Hachmane
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Charlotta S Olofsson
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden.
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37
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Xie L, Zhang Y, Gunasekar SK, Mishra A, Cao L, Sah R. Induction of adipose and hepatic SWELL1 expression is required for maintaining systemic insulin-sensitivity in obesity. Channels (Austin) 2017; 11:673-677. [PMID: 28873008 DOI: 10.1080/19336950.2017.1373225] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Obesity is associated with a loss of insulin-sensitivity and systemic dysglycemia, resulting in Type 2 diabetes, however the molecular mechanisms underlying this association are unclear. Through adipocyte patch-clamp studies, we recently showed that SWELL1 is required for the Volume-Regulated Anion Current (VRAC) in adipocytes and that SWELL1-mediated VRAC is activated by both mechanical and pathophysiological adipocyte expansion. We also demonstrated that adipocyte SWELL1 is required for maintaining insulin signaling and glucose homeostasis, particularly in the setting of obesity. Here we show that SWELL1 protein expression is induced in subcutaneous fat, visceral fat and liver in the setting of obesity. Long- term AAV/rec2-shRNA mediated SWELL1 knock-down in both fat and liver are associated with increased weight gain, increased adiposity and exacerbated insulin resistance in mice raised on a high-fat diet. These data further support the notion that SWELL1 induction occurs in insulin- sensitive tissues (liver and adipose) in the setting of over-nutrition and contributes to improved systemic glycemia by supporting enhanced insulin-sensitivity.
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Affiliation(s)
- Litao Xie
- a Department of Internal Medicine , Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine , Iowa City , IA , USA
| | - Yanhui Zhang
- a Department of Internal Medicine , Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine , Iowa City , IA , USA
| | - Susheel K Gunasekar
- a Department of Internal Medicine , Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine , Iowa City , IA , USA
| | - Anil Mishra
- a Department of Internal Medicine , Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine , Iowa City , IA , USA
| | - Lei Cao
- b Department of Cancer Biology and Genetics , The Ohio State University , Columbus , OH , USA
| | - Rajan Sah
- a Department of Internal Medicine , Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine , Iowa City , IA , USA.,c Fraternal Order of the Eagles Diabetes Research Center , Iowa City , IA , USA.,d Abboud Cardiovascular Research Center , University of Iowa , Carver College of Medicine , Iowa City , IA , USA
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Minchin JEN, Rawls JF. Elucidating the role of plexin D1 in body fat distribution and susceptibility to metabolic disease using a zebrafish model system. Adipocyte 2017; 6:277-283. [PMID: 28792859 DOI: 10.1080/21623945.2017.1356504] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Non-communicable diseases (NCDs) such as cardiovascular disease, diabetes and cancer were responsible for 68% of all deaths worldwide in 2012. The regional distribution of lipid deposited within adipose tissue (AT) - so called body fat distribution (BFD) - is a strong risk factor for NCDs. BFD is highly heritable; however, the genetic basis of BFD is almost entirely unknown. Genome-wide association studies have identified several loci associated with BFD, including at Plexin D1 (PLXND1) - a gene known to modulate angiogenesis. We recently demonstrated that zebrafish homozygous for a null mutation in plxnd1 had a reduced capacity to store lipid in visceral AT (VAT) leading to altered BFD. Moreover, we found that type V collagens were upregulated in plxnd1 mutants, and mediated the inhibitory effect of Plxnd1 on VAT growth. These results strengthen evidence that Plxnd1 influences BFD in human populations, and validate zebrafish as a model to study BFD. However, many pertinent questions remain unanswered. Here we outline potential Plxnd1 mechanisms of action in AT, and describe the genetic architecture at human PLXND1 that is associated with BFD and NCD susceptibility.
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Affiliation(s)
- James E. N. Minchin
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - John F. Rawls
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
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A novel micro-to-macro structural approach for mechanical characterization of adipose tissue extracellular matrix. J Mech Behav Biomed Mater 2017; 77:140-147. [PMID: 28910711 DOI: 10.1016/j.jmbbm.2017.09.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 08/26/2017] [Accepted: 09/03/2017] [Indexed: 01/23/2023]
Abstract
Mechanical characterization of adipose tissue micro-components is important for various biomedical applications such as tissue engineering and predicting adipose tissue response to forces involved in relevant medical intervention procedures (e.g. breast needle biopsy). For this characterization, we introduce a novel structural method for micromechanical modeling of the adipose tissue. The micromechanical model was developed using fluid-structure interaction (FSI) formulation. We utilized this model within an inverse problem framework to estimate the hyperelastic parameters of adipose tissue extracellular matrix (ECM). Using this framework, the ECM hyperelastic parameters were changed in the FSI model systematically using an optimization algorithm such that the mechanical response obtained from the FSI model matches the corresponding experimental response reported in previous studies. To account for adipocyte size variation, the hyperelastic parameters were determined for different adipocyte sizes in the FSI model. Results obtained in this investigation indicate that at various strains under quasi-static conditions, the stiffness of adipose tissue ECM is ~ (2-3) times higher than that of the adipose tissue. The results also indicate a very good fit between the FSI model responses and their experimental counterparts. This indicates the reliability of the proposed FSI model in capturing major elements of the adipose tissue micromechanics. As such, it is potentially useful in applications such as tissue engineering, estimating tissue deformation pertaining to medical intervention and cataloging the mechanical properties of adipose tissue under health and pathological conditions. It can also be utilized as a forward model for developing inversion algorithms designed to determine pathological adipose microstructural alterations.
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Vink RG, Roumans NJ, van der Kolk BW, Fazelzadeh P, Boekschoten MV, Mariman EC, van Baak MA. Adipose Tissue Meal-Derived Fatty Acid Uptake Before and After Diet-Induced Weight Loss in Adults with Overweight and Obesity. Obesity (Silver Spring) 2017. [PMID: 28639346 DOI: 10.1002/oby.21903] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
OBJECTIVE This study investigated whether diet-induced weight loss alters indices of in vivo postprandial fat uptake in adipose tissue (AT) and whether these changes are associated with weight regain in adults with overweight and obesity. METHODS In this randomized controlled trial, 16 (6 male) individuals (BMI: 28-35 kg/m2 ) were randomized to either a low-calorie diet (1,250 kcal/d) for 12 weeks or a very-low-calorie diet (500 kcal/d) for 5 weeks (weight loss [WL] period) followed by a 4-week weight-stable (WS) period (together, the dietary intervention [DI] period) and a 9-month follow-up period. Arteriovenous difference measurements combined with stable isotope labeling ([U-13 C] palmitate) of a mixed meal were used to determine postprandial fatty acid uptake in AT. RESULTS Body weight was significantly reduced during the WL period (-8.2 ± 0.6 kg, P < 0.001), remained stable during the WS period (0.4 ± 0.3 kg, P = 0.150), and increased during follow-up (3.5 ± 0.8 kg, P = 0.001). Meal-derived in vivo fatty acid uptake dynamics across AT and expression of genes important for fatty acid uptake, storage, and release were not significantly changed during the DI period. CONCLUSIONS Subcutaneous AT does not appear prone to enhanced meal-derived fatty acid uptake after weight loss, nor were fatty acid uptake dynamics detected as related to weight regain.
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Affiliation(s)
- Roel G Vink
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Nadia J Roumans
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Birgitta W van der Kolk
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Parastoo Fazelzadeh
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Mark V Boekschoten
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Edwin C Mariman
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Marleen A van Baak
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
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Fat-enriched rather than high-fructose diets promote whitening of adipose tissue in a sex-dependent manner. J Nutr Biochem 2017; 49:22-29. [PMID: 28863366 DOI: 10.1016/j.jnutbio.2017.07.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 06/25/2017] [Accepted: 07/19/2017] [Indexed: 12/12/2022]
Abstract
Adipose tissue is a critical regulator of energy metabolism and an effector organ of excessive caloric intake. We studied the effects of high-fructose (HFruD), high-fat (HFD) and mixed high-sucrose and high-fat diet (HFHSD) on adipocyte morphology and biology and consecutive metabolic effects in male and female C57BL/6 mice. Forty male and 40 female mice were randomly assigned to one of four dietary groups and fed for 10 weeks ad libitum. After 10 weeks of feeding, mice were analyzed in regard to glucose metabolism, insulin sensitivity and alteration in adipocyte morphology and function. Weight gain and diminished insulin sensitivity in HFD- and HFHSD-fed mice were accompanied by increased adipocyte size and a shift in size distribution towards larger adipocytes in all mice. The latter effect was also found but less pronounced in HFruD-fed mice, while insulin sensitivity and body weight remained unaffected. In male mice, expansion of white adipocytes along with decreased uncoupling protein 1 (UCP-1) expression and alterations of mitochondrial biogenesis was found after HFD and HFHSD feeding, while in female mice, UCP-1 expression was also reduced in the HFruD dietary group. Diet-induced cellular alterations were less pronounced in female mice. Our data demonstrate that high-fat rather than high fructose consumption drives metabolically disadvantageous alterations of adipocyte differentiation involving whitening and insulin resistance in a sex-dependent manner with most deleterious effects seen upon administration of combined sucrose and fat-enriched diet in male mice.
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Zhang Y, Xie L, Gunasekar SK, Tong D, Mishra A, Gibson WJ, Wang C, Fidler T, Marthaler B, Klingelhutz A, Abel ED, Samuel I, Smith JK, Cao L, Sah R. SWELL1 is a regulator of adipocyte size, insulin signalling and glucose homeostasis. Nat Cell Biol 2017; 19:504-517. [PMID: 28436964 PMCID: PMC5415409 DOI: 10.1038/ncb3514] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 03/16/2017] [Indexed: 12/15/2022]
Abstract
Adipocytes undergo considerable volumetric expansion in the setting of obesity. It has been proposed that such marked increases in adipocyte size may be sensed via adipocyte-autonomous mechanisms to mediate size-dependent intracellular signalling. Here, we show that SWELL1 (LRRC8a), a member of the Leucine-Rich Repeat Containing protein family, is an essential component of a volume-sensitive ion channel (VRAC) in adipocytes. We find that SWELL1-mediated VRAC is augmented in hypertrophic murine and human adipocytes in the setting of obesity. SWELL1 regulates adipocyte insulin-PI3K-AKT2-GLUT4 signalling, glucose uptake and lipid content via SWELL1 C-terminal leucine-rich repeat domain interactions with GRB2/Cav1. Silencing GRB2 in SWELL1 KO adipocytes rescues insulin-pAKT2 signalling. In vivo, shRNA-mediated SWELL1 knockdown and adipose-targeted SWELL1 knockout reduce adiposity and adipocyte size in obese mice while impairing systemic glycaemia and insulin sensitivity. These studies identify SWELL1 as a cell-autonomous sensor of adipocyte size that regulates adipocyte growth, insulin sensitivity and glucose tolerance.
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Affiliation(s)
- Yanhui Zhang
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
| | - Litao Xie
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
| | - Susheel K. Gunasekar
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
| | - Dan Tong
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
| | - Anil Mishra
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
| | | | - Chuansong Wang
- Department of Cancer Biology and Genetics, The Ohio State University, Columbus, Ohio
| | - Trevor Fidler
- Fraternal Order of the Eagles Diabetes Research Center, Iowa City, IA, 52242
| | - Brodie Marthaler
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
| | - Aloysius Klingelhutz
- Department of Microbiology, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
| | - E. Dale Abel
- Fraternal Order of the Eagles Diabetes Research Center, Iowa City, IA, 52242
| | - Isaac Samuel
- Department of Surgery, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
| | - Jessica K. Smith
- Department of Surgery, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
| | - Lei Cao
- Department of Cancer Biology and Genetics, The Ohio State University, Columbus, Ohio
| | - Rajan Sah
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA, 52242
- Fraternal Order of the Eagles Diabetes Research Center, Iowa City, IA, 52242
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Temporal Changes in Gene Expression Profile during Mature Adipocyte Dedifferentiation. Int J Genomics 2017; 2017:5149362. [PMID: 28409151 PMCID: PMC5376413 DOI: 10.1155/2017/5149362] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 01/29/2017] [Indexed: 01/25/2023] Open
Abstract
Objective. To characterize changes in gene expression profile during human mature adipocyte dedifferentiation in ceiling culture. Methods. Subcutaneous (SC) and omental (OM) adipose tissue samples were obtained from 4 participants paired for age and BMI. Isolated adipocytes were dedifferentiated in ceiling culture. Gene expression analysis at days 0, 4, 7, and 12 of the cultures was performed using Affymetrix Human Gene 2.0 STvi arrays. Hierarchical clustering according to similarity of expression changes was used to identify overrepresented functions. Results. Four clusters gathered genes with similar expression between day 4 to day 7 but decreasing expression from day 7 to day 12. Most of these genes coded for proteins involved in adipocyte functions (LIPE, PLIN1, DGAT2, PNPLA2, ADIPOQ, CEBPA, LPL, FABP4, SCD, INSR, and LEP). Expression of several genes coding for proteins implicated in cellular proliferation and growth or cell cycle increased significantly from day 7 to day 12 (WNT5A, KITLG, and FGF5). Genes coding for extracellular matrix proteins were differentially expressed between days 0, 4, 7, and 12 (COL1A1, COL1A2, and COL6A3, MMP1, and TGFB1). Conclusion. Dedifferentiation is associated with downregulation of transcripts encoding proteins involved in mature adipocyte functions and upregulation of genes involved in matrix remodeling, cellular development, and cell cycle.
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Mitochondrial Function and Cell Size: An Allometric Relationship. Trends Cell Biol 2017; 27:393-402. [PMID: 28284466 DOI: 10.1016/j.tcb.2017.02.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/08/2017] [Accepted: 02/15/2017] [Indexed: 01/09/2023]
Abstract
Allometric scaling of metabolic rate results in lower total mitochondrial oxygen consumption with increasing organismal size. This is considered a universal law in biology. Here, we discuss how allometric laws impose size-dependent limits to mitochondrial activity at the cellular level. This cell-size-dependent mitochondrial metabolic activity results in nonlinear scaling of metabolism in proliferating cells, which can explain size homeostasis. The allometry in mitochondrial activity can be controlled through mitochondrial fusion and fission machinery, suggesting that mitochondrial connectivity can bypass transport limitations, the presumed biophysical basis for allometry. As physical size affects cellular functionality, cell-size-dependent metabolism becomes directly relevant for development, metabolic diseases, and aging.
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Lee NE, Kim SJ, Yang SJ, Joo SY, Park H, Lee KW, Yang HM, Park JB. Comparative characterization of mesenchymal stromal cells from multiple abdominal adipose tissues and enrichment of angiogenic ability via CD146 molecule. Cytotherapy 2017; 19:170-180. [DOI: 10.1016/j.jcyt.2016.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 10/20/2016] [Accepted: 11/03/2016] [Indexed: 12/20/2022]
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d-Psicose, a sugar substitute, suppresses body fat deposition by altering networks of inflammatory response and lipid metabolism in C57BL/6J-ob/ob mice. J Funct Foods 2017. [DOI: 10.1016/j.jff.2016.11.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Adipose Tissue Hypoxia in Obesity and Its Impact on Preadipocytes and Macrophages: Hypoxia Hypothesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 960:305-326. [PMID: 28585205 DOI: 10.1007/978-3-319-48382-5_13] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Obese subjects exhibit lower adipose tissue oxygen consumption in accordance with the lower adipose tissue blood flow. Thus, compared with lean subjects, obese subjects have 44% lower capillary density and 58% lower vascular endothelial growth factor (VEGF). The VEGF expression together with hypoxia-inducible transcription factor-1 (HIF-1) activity also requires phosphatidylinositol 3-kinase (PI3K)- and target of rapamycin (TOR)-mediated signaling. HIF-1alpha is an important signaling molecule for hypoxia to induce the inflammatory responses. Hypoxia affects a number of biological functions, such as angiogenesis, cell proliferation, apoptosis, inflammation and insulin resistance. Additionally, reactive oxygen radical (ROS) generation at mitochondria is responsible for propagation of the hypoxic signal. Actually mitochondrial ROS (mtROS) production, but not oxygen consumption is required for hypoxic HIF-1alpha protein stabilization. Adipocyte mitochondrial oxidative capacity is reduced in obese compared with non-obese adults. In this respect, mitochondrial dysfunction of adipocyte is associated with the overall adiposity. Furthermore, hypoxia also inhibits macrophage migration from the hypoxic adipose tissue. Alterations in oxygen availability of adipose tissue directly affect the macrophage polarization and are responsible from dysregulated adipocytokines production in obesity. Hypoxia also inhibits adipocyte differentiation from preadipocytes. In addition to stressed adipocytes, hypoxia contributes to immune cell immigration and activation which further aggravates adipose tissue fibrosis. Fibrosis is initiated in response to adipocyte hypertrophy in obesity.
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Kaburagi T, Kizuka Y, Kitazume S, Taniguchi N. The Inhibitory Role of α2,6-Sialylation in Adipogenesis. J Biol Chem 2016; 292:2278-2286. [PMID: 28031460 DOI: 10.1074/jbc.m116.747667] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 12/17/2016] [Indexed: 12/19/2022] Open
Abstract
Adipose tissue plays critical roles in obesity and related diseases such as diabetes and cardiovascular diseases. Previous reports suggest that glycans, the most common posttranslational modifications, are involved in obesity-related diseases, but what type of glycan regulates adipogenesis during obesity remains unclear. In this study, we first quantified the mRNA levels of 167 genes (encoding 144 glycosyltransferases and 23 related enzymes) in visceral adipose tissues (VATs) from control mice and high-fat diet (HFD)-induced obese mice. We found that a gene encoding β-galactoside α2,6-sialyltransferase-1 (St6gal1), a key enzyme responsible for the biosynthesis of α2,6-linked sialic acid in N-linked glycans, was most down-regulated in VATs from obese mice. We confirmed the reduction in α2,6-sialic acid in VATs from obese mice and differentiated adipocyte model 3T3-L1 cells. Using proteomic analysis, integrin-β1 was identified as one of the target α2,6-sialylated proteins in adipose tissues, and phosphorylation of its downstream molecule focal adhesion kinase was found to be decreased after HFD feeding. St6gal1 overexpression in differentiating 3T3-L1 cells inhibited adipogenesis with increased phosphorylation of focal adhesion kinase. Furthermore, St6gal1 knockout mice exhibited increased bodyweight and VAT weight after HFD feeding. The down-regulation of St6gal1 during adipogenesis was canceled by treatment with a DNA methyltransferase inhibitor, suggesting an involvement of epigenetic DNA methylation in St6gal1 silencing. Our findings suggest that ST6GAL1 has an inhibitory role in adipogenesis through integrin-β1 activation, providing new insights into the roles and regulation mechanisms of glycans in adipocytes during obesity.
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Affiliation(s)
- Tomoko Kaburagi
- From the Department of Health Science, Faculty of Sports and Health Sciences, Daito Bunka University, Higashi-Matsuyama, Saitama 355-8681, Japan and .,the Disease Glycomics Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, Global Research Cluster, RIKEN, Wako, Saitama 351-0198, Japan
| | - Yasuhiko Kizuka
- the Disease Glycomics Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, Global Research Cluster, RIKEN, Wako, Saitama 351-0198, Japan
| | - Shinobu Kitazume
- the Disease Glycomics Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, Global Research Cluster, RIKEN, Wako, Saitama 351-0198, Japan
| | - Naoyuki Taniguchi
- the Disease Glycomics Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center for Systems Chemical Biology, Global Research Cluster, RIKEN, Wako, Saitama 351-0198, Japan
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Abstract
PURPOSE OF REVIEW Purpose of review: It is becoming increasingly clear that some obese individuals do not develop dyslipidemia and instead remain healthy, while some normal weight individuals become dyslipidemic and unhealthy. RECENT FINDINGS The present review examines the similarities and differences between healthy and unhealthy individuals with and without obesity and discusses putative underlying mechanisms of dyslipidemia. The presence of dyslipidemia and compromised metabolic health in both lean and obese individuals suggests that the obese phenotype per se does not represent a main independent risk factor for the development of dyslipidemia and that dyslipidemia, rather than obesity, may be the driver of metabolic diseases. Notably, adipose tissue dysfunction and ectopic lipid deposition, in particular in the liver, seems a common trait of unhealthy individuals.
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Affiliation(s)
- David H Ipsen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870, Frederiksberg C, Denmark
| | - Pernille Tveden-Nyborg
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870, Frederiksberg C, Denmark
| | - Jens Lykkesfeldt
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870, Frederiksberg C, Denmark.
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Lee SA, Yuen JJ, Jiang H, Kahn BB, Blaner WS. Adipocyte-specific overexpression of retinol-binding protein 4 causes hepatic steatosis in mice. Hepatology 2016; 64:1534-1546. [PMID: 27227735 PMCID: PMC5074895 DOI: 10.1002/hep.28659] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 05/16/2016] [Indexed: 12/27/2022]
Abstract
UNLABELLED There is considerable evidence that both retinoids and retinol-binding protein 4 (RBP4) contribute to the development of liver disease. To understand the basis for this, we generated and studied transgenic mice that express human RBP4 (hRBP4) specifically in adipocytes. When fed a chow diet, these mice show an elevation in adipose total RBP4 (mouse RBP4 + hRBP4) protein levels. However, no significant differences in plasma RBP4 or retinol levels or in hepatic or adipose retinoid (retinol, retinyl ester, and all-trans-retinoic acid) levels were observed. Strikingly, male adipocyte-specific hRBP4 mice fed a standard chow diet display significantly elevated hepatic triglyceride levels at 3-4 months of age compared to matched littermate controls. When mice were fed a high-fat diet, this hepatic phenotype, as well as other metabolic phenotypes (obesity and glucose intolerance), worsened. Because adipocyte-specific hRBP4 mice have increased tumor necrosis factor-α and leptin expression and crown-like structures in adipose tissue, our data are consistent with the notion that adipose tissue is experiencing RBP4-induced inflammation that stimulates increased lipolysis within adipocytes. Our data further establish that elevated hepatic triglyceride levels result from increased hepatic uptake of adipose-derived circulating free fatty acids. We obtained no evidence that elevated hepatic triglyceride levels arise from increased hepatic de novo lipogenesis, decreased hepatic free fatty acid oxidation, or decreased very-low-density lipoprotein secretion. CONCLUSION Our investigations establish that RBP4 expressed in adipocytes induces hepatic steatosis arising from primary effects occurring in adipose tissue. (Hepatology 2016;64:1534-1546).
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Affiliation(s)
- Seung-Ah Lee
- Department of Medicine, College of Physicians and Surgeons, Columbia University, 650 W. 168th Street, New York, NY 10032
| | - Jason J. Yuen
- Department of Medicine, College of Physicians and Surgeons, Columbia University, 650 W. 168th Street, New York, NY 10032
| | - Hongfeng Jiang
- Department of Medicine, College of Physicians and Surgeons, Columbia University, 650 W. 168th Street, New York, NY 10032
| | - Barbara B. Kahn
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215
| | - William S. Blaner
- Department of Medicine, College of Physicians and Surgeons, Columbia University, 650 W. 168th Street, New York, NY 10032
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