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Gunasekar SK, Heebink J, Carpenter DH, Kumar A, Xie L, Zhang H, Schilling JD, Sah R. Adipose-targeted SWELL1 deletion exacerbates obesity- and age-related nonalcoholic fatty liver disease. JCI Insight 2023; 8:e154940. [PMID: 36749637 PMCID: PMC10077479 DOI: 10.1172/jci.insight.154940] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 01/27/2023] [Indexed: 02/08/2023] Open
Abstract
Healthy expansion of adipose tissue is critical for the maintenance of metabolic health, providing an optimized reservoir for energy storage in the form of triacylglycerol-rich lipoproteins. Dysfunctional adipocytes that are unable to efficiently store lipid can result in lipodystrophy and contribute to nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome. Leucine-rich repeat containing protein 8a/SWELL1 functionally encodes the volume-regulated anion channel complex in adipocytes, is induced in early obesity, and is required for normal adipocyte expansion during high-fat feeding. Adipose-specific SWELL1 ablation (Adipo KO) leads to insulin resistance and hyperglycemia during caloric excess, both of which are associated with NAFLD. Here, we show that Adipo-KO mice exhibited impaired adipose depot expansion and excess lipolysis when raised on a variety of high-fat diets, resulting in increased diacylglycerides and hepatic steatosis, thereby driving liver injury. Liver lipidomic analysis revealed increases in oleic acid-containing hepatic triacylglycerides and injurious hepatic diacylglyceride species, with reductions in hepatocyte-protective phospholipids and antiinflammatory free fatty acids. Aged Adipo-KO mice developed hepatic steatosis on a regular chow diet, and Adipo-KO male mice developed spontaneous, aggressive hepatocellular carcinomas (HCCs). These data highlight the importance of adipocyte SWELL1 for healthy adipocyte expansion to protect against NAFLD and HCC in the setting of overnutrition and with aging.
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Affiliation(s)
- Susheel K. Gunasekar
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
| | - John Heebink
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Danielle H. Carpenter
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Ashutosh Kumar
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Litao Xie
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Haixia Zhang
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Joel D. Schilling
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Rajan Sah
- Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri, USA
- John Cochran VA Medical Center, St. Louis, Missouri, USA
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2
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Naftaly A, Kislev N, Izgilov R, Adler R, Silber M, Shalgi R, Benayahu D. Nutrition Alters the Stiffness of Adipose Tissue and Cell Signaling. Int J Mol Sci 2022; 23:ijms232315237. [PMID: 36499567 PMCID: PMC9736042 DOI: 10.3390/ijms232315237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/17/2022] [Accepted: 11/26/2022] [Indexed: 12/12/2022] Open
Abstract
Adipose tissue is a complex organ composed of various cell types and an extracellular matrix (ECM). The visceral adipose tissue (VAT) is dynamically altered in response to nutritional regimens that lead to local cues affecting the cells and ECM. The adipocytes are in conjunction with the surrounding ECM that maintains the tissue's niche, provides a scaffold for cells and modulates their signaling. In this study, we provide a better understanding of the crosstalk between nutritional regimens and the ECM's stiffness. Histological analyses showed that the adipocytes in mice fed a high-fat diet (HFD) were increased in size, while the ECM was also altered with changes in mass and composition. HFD-fed mice exhibited a decrease in elastin and an increase in collagenous proteins. Rheometer measurements revealed a stiffer ECM in whole tissue (nECM) and decellularized (deECM) in HFD-fed animals. These alterations in the ECM regulate cellular activity and influence their metabolic function. HFD-fed mice expressed high levels of the receptor for advanced-glycation-end-products (RAGE), indicating that AGEs might play a role in these processes. The cells also exhibited an increase in phosphoserine332 of IRS-1, a decrease in the GLUT4 transporter levels at the cells' membrane, and a consequent reduction in insulin sensitivity. These results show how alterations in the stiffness of ECM proteins can affect the mechanical cues transferred to adipocytes and, thereby, influence the adipocytes' functionality, leading to metabolic disorders.
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3
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Lecoutre S, Lambert M, Drygalski K, Dugail I, Maqdasy S, Hautefeuille M, Clément K. Importance of the Microenvironment and Mechanosensing in Adipose Tissue Biology. Cells 2022; 11:cells11152310. [PMID: 35954152 PMCID: PMC9367348 DOI: 10.3390/cells11152310] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/19/2022] [Accepted: 07/23/2022] [Indexed: 11/16/2022] Open
Abstract
The expansion of adipose tissue is an adaptive mechanism that increases nutrient buffering capacity in response to an overall positive energy balance. Over the course of expansion, the adipose microenvironment undergoes continual remodeling to maintain its structural and functional integrity. However, in the long run, adipose tissue remodeling, typically characterized by adipocyte hypertrophy, immune cells infiltration, fibrosis and changes in vascular architecture, generates mechanical stress on adipose cells. This mechanical stimulus is then transduced into a biochemical signal that alters adipose function through mechanotransduction. In this review, we describe the physical changes occurring during adipose tissue remodeling, and how they regulate adipose cell physiology and promote obesity-associated dysfunction in adipose tissue.
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Affiliation(s)
- Simon Lecoutre
- Nutrition and Obesities: Systemic Approaches Research Group (Nutri-Omics), Sorbonne Université, INSERM, F-75013 Paris, France; (S.L.); (K.D.); (I.D.)
| | - Mélanie Lambert
- Labex Inflamex, Université Sorbonne Paris Nord, INSERM, F-93000 Bobigny, France;
| | - Krzysztof Drygalski
- Nutrition and Obesities: Systemic Approaches Research Group (Nutri-Omics), Sorbonne Université, INSERM, F-75013 Paris, France; (S.L.); (K.D.); (I.D.)
| | - Isabelle Dugail
- Nutrition and Obesities: Systemic Approaches Research Group (Nutri-Omics), Sorbonne Université, INSERM, F-75013 Paris, France; (S.L.); (K.D.); (I.D.)
| | - Salwan Maqdasy
- Department of Medicine (H7), Karolinska Institutet Hospital, C2-94, 14186 Stockholm, Sweden;
| | - Mathieu Hautefeuille
- Laboratoire de Biologie du Développement (UMR 7622), IBPS, Sorbonne Université, F-75005 Paris, France;
| | - Karine Clément
- Nutrition and Obesities: Systemic Approaches Research Group (Nutri-Omics), Sorbonne Université, INSERM, F-75013 Paris, France; (S.L.); (K.D.); (I.D.)
- Assistance Publique Hôpitaux de Paris, Nutrition Department, CRNH Ile-de-France, Pitié-Salpêtrière Hospital, F-75013 Paris, France
- Correspondence: or
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4
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Liu X, Liu L, Zhao J, Wang H, Li Y. Mechanotransduction regulates inflammation responses of epicardial adipocytes in cardiovascular diseases. Front Endocrinol (Lausanne) 2022; 13:1080383. [PMID: 36589802 PMCID: PMC9800500 DOI: 10.3389/fendo.2022.1080383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
Adipose tissue is a crucial regulator in maintaining cardiovascular homeostasis by secreting various bioactive products to mediate the physiological function of the cardiovascular system. Accumulating evidence shows that adipose tissue disorders contribute to several kinds of cardiovascular disease (CVD). Furthermore, the adipose tissue would present various biological effects depending on its tissue localization and metabolic statuses, deciding the individual cardiometabolic risk. Crosstalk between adipose and myocardial tissue is involved in the pathophysiological process of arrhythmogenic right ventricular cardiomyopathy (ARVC), cardiac fibrosis, heart failure, and myocardial infarction/atherosclerosis. The abnormal distribution of adipose tissue in the heart might yield direct and/or indirect effects on cardiac function. Moreover, mechanical transduction is critical for adipocytes in differentiation, proliferation, functional maturity, and homeostasis maintenance. Therefore, understanding the features of mechanotransduction pathways in the cellular ontogeny of adipose tissue is vital for underlining the development of adipocytes involved in cardiovascular disorders, which would preliminarily contribute positive implications on a novel therapeutic invention for cardiovascular diseases. In this review, we aim to clarify the role of mechanical stress in cardiac adipocyte homeostasis and its interplay with maintaining cardiac function.
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Affiliation(s)
- Xiaoliang Liu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Lei Liu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Junfei Zhao
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
- *Correspondence: Yifei Li, ; Junfei Zhao, ; Hua Wang,
| | - Hua Wang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
- *Correspondence: Yifei Li, ; Junfei Zhao, ; Hua Wang,
| | - Yifei Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
- *Correspondence: Yifei Li, ; Junfei Zhao, ; Hua Wang,
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5
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Sun Z, Gepner BD, Cottler PS, Lee SH, Kerrigan JR. In Vitro Mechanical Characterization and Modeling of Subcutaneous Adipose Tissue: A Comprehensive Review. J Biomech Eng 2021; 143:070803. [PMID: 33625495 DOI: 10.1115/1.4050286] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Indexed: 11/08/2022]
Abstract
Mechanical models of adipose tissue are important for various medical applications including cosmetics, injuries, implantable drug delivery systems, plastic surgeries, biomechanical applications such as computational human body models for surgery simulation, and blunt impact trauma prediction. This article presents a comprehensive review of in vivo experimental approaches that aimed to characterize the mechanical properties of adipose tissue, and the resulting constitutive models and model parameters identified. In particular, this study examines the material behavior of adipose tissue, including its nonlinear stress-strain relationship, viscoelasticity, strain hardening and softening, rate-sensitivity, anisotropy, preconditioning, failure behavior, and temperature dependency.
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Affiliation(s)
- Zhaonan Sun
- Center for Applied Biomechanics, University of Virginia, Charlottesville, VA 22911
| | - Bronislaw D Gepner
- Center for Applied Biomechanics, University of Virginia, Charlottesville, VA 22911
| | - Patrick S Cottler
- Department of Plastic Surgery, University of Virginia, Charlottesville, VA 22903
| | - Sang-Hyun Lee
- Center for Applied Biomechanics, University of Virginia, Charlottesville, VA 22911
| | - Jason R Kerrigan
- Center for Applied Biomechanics, University of Virginia, Charlottesville, VA 22911
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6
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Mor-Yossef Moldovan L, Kislev N, Lustig M, Pomeraniec L, Benayahu D. Biomechanical stimulation effects on the metabolism of adipocyte. J Cell Physiol 2020; 235:8702-8713. [PMID: 32330316 DOI: 10.1002/jcp.29714] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/18/2020] [Accepted: 04/05/2020] [Indexed: 12/30/2022]
Abstract
Adipose tissue plays a leading role in obesity, which, in turn, can lead to Type 2 diabetes. Adipocytes (AD) respond to the biomechanical stimulation experienced in fat tissue under static stretch during prolonged sitting or lying. To investigate the effect of such chronic stimulation on adipocyte cell metabolism, we used an in vitro system to mimic the static stretch conditions. Under in vitro culture stretching, cells were analyzed at the single-cell level and we measured an increase in the projected area of the AD and higher content of lipid droplets. A decrease in the projected area of these cells' nucleus is associated with peroxisome proliferator-activated receptor-gamma expression and heterochromatin. This is the first study to reveal proteins that were altered under static stretch following a mass spectrometry analysis and main pathways that affect cell fate and metabolism. Bioinformatics analysis of the proteins indicated an increase in mitochondrial activity and associated pathways under static stretch stimulation. Quantification of the mitochondrial activity by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay and the ATPase related proteins specifically measured ATP5B indicated an increase in adipogenesis which points to a higher rate of cell metabolism under static stretch. In summary, our results elaborate on the metabolism of AD exposed to biomechanical stimulation, that is, associated with altered cellular protein profile and thereby influenced cell fate. The static stretch stimulation accelerated adipocyte differentiation through increased mitochondrial activity. Hence, in this study, we introduce a new perspective in understanding the molecular regulation of mechano-transduction in adipogenesis.
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Affiliation(s)
- Lisa Mor-Yossef Moldovan
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Nadav Kislev
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Maayan Lustig
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Leslie Pomeraniec
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Dafna Benayahu
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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7
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Suchý T, Zieschang C, Popkova Y, Kaczmarek I, Weiner J, Liebing AD, Çakir MV, Landgraf K, Gericke M, Pospisilik JA, Körner A, Heiker JT, Dannenberger D, Schiller J, Schöneberg T, Liebscher I, Thor D. The repertoire of Adhesion G protein-coupled receptors in adipocytes and their functional relevance. Int J Obes (Lond) 2020; 44:2124-2136. [PMID: 32203115 PMCID: PMC7508673 DOI: 10.1038/s41366-020-0570-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/25/2020] [Accepted: 03/04/2020] [Indexed: 01/30/2023]
Abstract
BACKGROUND G protein-coupled receptors (GPCR) are well-characterized regulators of a plethora of physiological functions among them the modulation of adipogenesis and adipocyte function. The class of Adhesion GPCR (aGPCR) and their role in adipose tissue, however, is poorly studied. With respect to the demand for novel targets in obesity treatment, we present a comprehensive study on the expression and function of this enigmatic GPCR class during adipogenesis and in mature adipocytes. METHODS The expression of all aGPCR representatives was determined by reanalyzing RNA-Seq data and by performing qPCR in different mouse and human adipose tissues under low- and high-fat conditions. The impact of aGPCR expression on adipocyte differentiation and lipid accumulation was studied by siRNA-mediated knockdown of all expressed members of this receptor class. The biological characteristics and function of mature adipocytes lacking selected aGPCR were analyzed by mass spectrometry and biochemical methods (lipolysis, glucose uptake, adiponectin secretion). RESULTS More than ten aGPCR are significantly expressed in visceral and subcutaneous adipose tissues and several aGPCR are differentially regulated under high-caloric conditions in human and mouse. Receptor knockdown of six receptors resulted in an impaired adipogenesis indicating their expression is essential for proper adipogenesis. The altered lipid composition was studied in more detail for two representatives, ADGRG2/GPR64 and ADGRG6/GPR126. While GPR126 is mainly involved in adipocyte differentiation, GPR64 has an additional role in mature adipocytes by regulating metabolic processes. CONCLUSIONS Adhesion GPCR are significantly involved in qualitative and quantitative adipocyte lipid accumulation and can control lipolysis. Factors driving adipocyte formation and function are governed by signaling pathways induced by aGPCR yielding these receptors potential targets for treating obesity.
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Affiliation(s)
- Tomáš Suchý
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Christian Zieschang
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Yulia Popkova
- Institute for Medical Physics and Biophysics, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Isabell Kaczmarek
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Juliane Weiner
- Department of Endocrinology, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Aenne-Dorothea Liebing
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Mehmet Volkan Çakir
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Kathrin Landgraf
- Center for Pediatric Research Leipzig, Hospital for Children & Adolescents, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Martin Gericke
- Institute for Anatomy and Cell biology, Medical Faculty, Halle University, Halle (Saale), Germany
| | | | - Antje Körner
- Center for Pediatric Research Leipzig, Hospital for Children & Adolescents, Medical Faculty, Leipzig University, Leipzig, Germany
| | - John T Heiker
- IFB Adiposity Diseases, Leipzig University, Leipzig, Germany.,Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
| | - Dirk Dannenberger
- Leibniz Institute for Farm Animal Biology, Institute of Muscle Biology and Growth, Dummerstorf, Germany
| | - Jürgen Schiller
- Institute for Medical Physics and Biophysics, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Ines Liebscher
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany.
| | - Doreen Thor
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany.
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Brown Adipocyte and Splenocyte Co-Culture Maintains Regulatory T Cell Subset in Intermittent Hypobaric Conditions. Tissue Eng Regen Med 2019; 16:539-548. [PMID: 31624708 PMCID: PMC6778593 DOI: 10.1007/s13770-019-00205-y] [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: 02/25/2019] [Revised: 06/15/2019] [Accepted: 07/16/2019] [Indexed: 11/02/2022] Open
Abstract
Background Brown adipocytes have thermogenic characteristics in neonates and elicit anti-inflammatory responses. We postulated that thermogenic brown adipocytes produce distinctive intercellular effects in a hypobaric state. The purpose of this study is to analyze the correlation between brown adipocyte and regulatory T cell (Treg) expression under intermittent hypobaric conditions. Methods Brown and white adipocytes were harvested from the interscapular and flank areas of C57BL6 mice, respectively. Adipocytes were cultured with syngeneic splenocytes after isolation and differentiation. Intermittent hypobaric conditions were generated using cyclic negative pressure application for 48 h in both groups of adipocytes. Expression levels of Tregs (CD4 + CD25 + Foxp3 + T cells), cytokines [tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10), and the programmed death-ligand 1 (PD-L1)] co-inhibitory ligand were examined. Results Splenocytes, cultured with brown and white adipocytes, exhibited comparable Treg expression in a normobaric state. Under hypobaric conditions, brown adipocytes maintained a subset of Tregs. However, a decrease in Tregs was found in the white adipocyte group. TNF-α levels increased in both groups under hypobaric conditions. In the brown adipocyte group, anti-inflammatory IL-10 expression increased significantly; meanwhile, IL-10 expression decreased in the white adipocyte group. PD-L1 levels increased more significantly in brown adipocytes than in white adipocytes under hypobaric conditions. Conclusion Both brown and white adipocytes support Treg expression when they are cultured with splenocytes. Of note, brown adipocytes maintained Treg expression in intermittent hypobaric conditions. Anti-inflammatory cytokines and co-inhibitory ligands mediate the immunomodulatory effects of brown adipocytes under altered atmospheric conditions. Brown adipocytes showed the feasibility as a source of adjustment in physical stresses.
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Lustig M, Zadka Y, Levitsky I, Gefen A, Benayahu D. Adipocytes Migration is Altered Through Differentiation. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2019; 25:1195-1200. [PMID: 31358078 DOI: 10.1017/s1431927619014727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Adipogenesis is a developmental process in which an elongated preadipocyte differentiates to a round adipocyte along with the accumulation of lipid droplets. In the present study, we focus on the study of cell motility at the single-cell level, toward expanding our knowledge regarding the cytoskeleton alteration during differentiation; since-cell motility is mediated by cytoskeletal components. We used the holographic-microscopy live imaging technique to evaluate, for the first time in the literature, differences between the motility of nondifferentiated preadipocytes and differentiated mature adipocytes in living cell cultures over time. We revealed that mean motility speed of preadipocytes was significantly higher (fourfold) than that of adipocytes, and that the movement of preadipocytes is less consistent and more extensive. Furthermore, we found that preadipocytes tend to migrate to farther distances, while mature adipocytes remain relatively close to their original location. The results presented here are in agreement with the fact that the cytoskeleton of adipocytes is altered during differentiation and similarly, points to the fact that the cell-sensing mechanisms are changing during differentiation. Our research paves the way to gain better insights of the differentiation process and its implications on larger scale systems in the context of obesity.
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Affiliation(s)
- Maayan Lustig
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Yuliya Zadka
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Irena Levitsky
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Amit Gefen
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Dafna Benayahu
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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10
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Lustig M, Feng Q, Payan Y, Gefen A, Benayahu D. Noninvasive Continuous Monitoring of Adipocyte Differentiation: From Macro to Micro Scales. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2019; 25:119-128. [PMID: 30712528 DOI: 10.1017/s1431927618015520] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
3T3-L1 cells serve as model systems for studying adipogenesis and research of adipose tissue-related diseases, e.g. obesity and diabetes. Here, we present two novel and complementary nondestructive methods for adipogenesis analysis of living cells which facilitate continuous monitoring of the same culture over extended periods of time, and are applied in parallel at the macro- and micro-scales. At the macro-scale, we developed visual differences mapping (VDM), a novel method which allows to determine level of adipogenesis (LOA)-a numerical index which quantitatively describes the extent of differentiation in the whole culture, and percentage area populated by adipocytes (PAPBA) across a whole culture, based on the apparent morphological differences between preadipocytes and adipocytes. At the micro-scale, we developed an improved version of our previously published image-processing algorithm, which now provides data regarding single-cell morphology and lipid contents. Both methods were applied here synergistically for measuring differentiation levels in cultures over multiple weeks. VDM revealed that the mean LOA value reached 1.11 ± 0.06 and the mean PAPBA value reached >60%. Micro-scale analysis revealed that during differentiation, the cells transformed from a fibroblast-like shape to a circular shape with a build-up of lipid droplets. We predict a vast potential for implementation of these methods in adipose-related pharmacological research, such as in metabolic-syndrome studies.
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Affiliation(s)
- Maayan Lustig
- Department of Biomedical Engineering, Faculty of Engineering,Tel Aviv University,Tel Aviv 6997801,Israel
| | - Qingling Feng
- Key Laboratory of Advanced Materials of Ministry of Education of China,School of Materials Science and Engineering, Tsinghua University,Beijing 100084,China
| | - Yohan Payan
- CNRS, Grenoble INP, TIMC-IMAG, University of Grenoble Alpes,Grenoble F-38000,France
| | - Amit Gefen
- Department of Biomedical Engineering, Faculty of Engineering,Tel Aviv University,Tel Aviv 6997801,Israel
| | - Dafna Benayahu
- Department of Cell and Developmental Biology,Sackler School of Medicine, Tel Aviv University,Tel Aviv 6997801,Israel
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11
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Archer E, Pavela G, McDonald S, Lavie CJ, Hill JO. Cell-Specific "Competition for Calories" Drives Asymmetric Nutrient-Energy Partitioning, Obesity, and Metabolic Diseases in Human and Non-human Animals. Front Physiol 2018; 9:1053. [PMID: 30147656 PMCID: PMC6097573 DOI: 10.3389/fphys.2018.01053] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 07/16/2018] [Indexed: 12/20/2022] Open
Abstract
The mammalian body is a complex physiologic “ecosystem” in which cells compete for calories (i.e., nutrient-energy). Axiomatically, cell-types with competitive advantages acquire a greater number of consumed calories, and when possible, increase in size and/or number. Thus, it is logical and parsimonious to posit that obesity is the competitive advantages of fat-cells (adipocytes) driving a disproportionate acquisition and storage of nutrient-energy. Accordingly, we introduce two conceptual frameworks. Asymmetric Nutrient-Energy Partitioning describes the context-dependent, cell-specific competition for calories that determines the partitioning of nutrient-energy to oxidation, anabolism, and/or storage; and Effective Caloric Intake which describes the number of calories available to constrain energy-intake via the inhibition of the sensorimotor appetitive cells in the liver and brain that govern ingestive behaviors. Inherent in these frameworks is the independence and dissociation of the energetic demands of metabolism and the neuro-muscular pathways that initiate ingestive behaviors and energy intake. As we demonstrate, if the sensorimotor cells suffer relative caloric deprivation via asymmetric competition from other cell-types (e.g., skeletal muscle- or fat-cells), energy-intake is increased to compensate for both real and merely apparent deficits in energy-homeostasis (i.e., true and false signals, respectively). Thus, we posit that the chronic positive energy balance (i.e., over-nutrition) that leads to obesity and metabolic diseases is engendered by apparent deficits (i.e., false signals) driven by the asymmetric inter-cellular competition for calories and concomitant differential partitioning of nutrient-energy to storage. These frameworks, in concert with our previous theoretic work, the Maternal Resources Hypothesis, provide a parsimonious and rigorous explanation for the rapid rise in the global prevalence of increased body and fat mass, and associated metabolic dysfunctions in humans and other mammals inclusive of companion, domesticated, laboratory, and feral animals.
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Affiliation(s)
| | - Gregory Pavela
- The University of Alabama at Birmingham, Birmingham, AL, United States
| | | | - Carl J Lavie
- School of Medicine, John Ochsner Heart and Vascular Institute, The University of Queensland, New Orleans, LA, United States
| | - James O Hill
- Center for Human Nutrition, University of Colorado Health Sciences Center, Denver, CO, United States
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Bidan CM, Fratzl M, Coullomb A, Moreau P, Lombard AH, Wang I, Balland M, Boudou T, Dempsey NM, Devillers T, Dupont A. Magneto-active substrates for local mechanical stimulation of living cells. Sci Rep 2018; 8:1464. [PMID: 29362476 PMCID: PMC5780514 DOI: 10.1038/s41598-018-19804-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 12/27/2017] [Indexed: 12/13/2022] Open
Abstract
Cells are able to sense and react to their physical environment by translating a mechanical cue into an intracellular biochemical signal that triggers biological and mechanical responses. This process, called mechanotransduction, controls essential cellular functions such as proliferation and migration. The cellular response to an external mechanical stimulation has been investigated with various static and dynamic systems, so far limited to global deformations or to local stimulation through discrete substrates. To apply local and dynamic mechanical constraints at the single cell scale through a continuous surface, we have developed and modelled magneto-active substrates made of magnetic micro-pillars embedded in an elastomer. Constrained and unconstrained substrates are analysed to map surface stress resulting from the magnetic actuation of the micro-pillars and the adherent cells. These substrates have a rigidity in the range of cell matrices, and the magnetic micro-pillars generate local forces in the range of cellular forces, both in traction and compression. As an application, we followed the protrusive activity of cells subjected to dynamic stimulations. Our magneto-active substrates thus represent a new tool to study mechanotransduction in single cells, and complement existing techniques by exerting a local and dynamic stimulation, traction and compression, through a continuous soft substrate.
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Affiliation(s)
- Cécile M Bidan
- University Grenoble Alpes, CNRS, LIPhy, 38000, Grenoble, France
| | - Mario Fratzl
- University Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000, Grenoble, France
- University Grenoble Alpes, CNRS, Grenoble INP, G2Elab, 38000, Grenoble, France
| | - Alexis Coullomb
- University Grenoble Alpes, CNRS, LIPhy, 38000, Grenoble, France
| | - Philippe Moreau
- University Grenoble Alpes, CNRS, LIPhy, 38000, Grenoble, France
| | - Alain H Lombard
- University Grenoble Alpes, CNRS, LIPhy, 38000, Grenoble, France
| | - Irène Wang
- University Grenoble Alpes, CNRS, LIPhy, 38000, Grenoble, France
| | - Martial Balland
- University Grenoble Alpes, CNRS, LIPhy, 38000, Grenoble, France
| | - Thomas Boudou
- University Grenoble Alpes, CNRS, LIPhy, 38000, Grenoble, France
| | - Nora M Dempsey
- University Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000, Grenoble, France
| | - Thibaut Devillers
- University Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000, Grenoble, France.
| | - Aurélie Dupont
- University Grenoble Alpes, CNRS, LIPhy, 38000, Grenoble, France.
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Lustig M, Gefen A, Benayahu D. Adipogenesis and lipid production in adipocytes subjected to sustained tensile deformations and elevated glucose concentration: a living cell-scale model system of diabesity. Biomech Model Mechanobiol 2018; 17:903-913. [PMID: 29335836 DOI: 10.1007/s10237-017-1000-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 12/29/2017] [Indexed: 12/15/2022]
Abstract
Adipocyte fate commitment is characterized by morphological changes of fibroblastic pre-adipocyte cells, and specifically by accumulation of lipid droplets (LDs) as part of the adipogenesis metabolism. Formation of LDs indicates the production of triglycerides from glucose through an insulin-regulated glucose internalization process. In obesity, adipocytes typically become insulin resistant, and glucose transport into the cells is impaired, resulting in type 2 diabetes. In the present study, we monitored the adipogenesis in 3T3-L1 cultured cells exposed to high (450 mg/dL hyperglycemia) and low (100 mg/dL physiological) glucose concentrations, in a novel cell culture model system of diabesity. In addition to glucose conditions, cells were concurrently exposed to different substrate tensile strains (12% and control) based on our prior work which revealed that adipogenesis is accelerated in cultures subjected to static, chronic substrate tensile deformations. Phase-contrast images were taken throughout the adipogenesis process (3 weeks) and were analyzed by an image processing algorithm which quantitatively monitors cell differentiation and lipid accumulation (number of LDs per cell and their radius as well as cell size and shape). The results indicated that high glucose concentrations and substrate tensile strains delivered to adipocytes accelerated lipid production by 1.7- and 1.4-fold, respectively. In addition, significant changes in average cell projected area and in other morphological attributes were observed during the differentiation process. The importance of this study is in characterizing the adipogenesis parameters as potential read-outs that can predict the occurrence of insulin resistance in the development of diabesity.
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Affiliation(s)
- Maayan Lustig
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Amit Gefen
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Dafna Benayahu
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, 69978, Tel Aviv, Israel.
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Unser AM, Tian Y, Xie Y. Opportunities and challenges in three-dimensional brown adipogenesis of stem cells. Biotechnol Adv 2015; 33:962-79. [PMID: 26231586 DOI: 10.1016/j.biotechadv.2015.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 07/07/2015] [Accepted: 07/23/2015] [Indexed: 12/21/2022]
Abstract
The formation of brown adipose tissue (BAT) via brown adipogenesis has become a notable process due to its ability to expend energy as heat with implications in the treatment of metabolic disorders and obesity. With the advent of complexity within white adipose tissue (WAT) along with inducible brown adipocytes (also known as brite and beige), there has been a surge in deciphering adipocyte biology as well as in vivo adipogenic microenvironments. A therapeutic outcome would benefit from understanding early events in brown adipogenesis, which can be accomplished by studying cellular differentiation. Pluripotent stem cells are an efficient model for differentiation and have been directed towards both white adipogenic and brown adipogenic lineages. The stem cell microenvironment greatly contributes to terminal cell fate and as such, has been mimicked extensively by various polymers including those that can form 3D hydrogel constructs capable of biochemical and/or mechanical modifications and modulations. Using bioengineering approaches towards the creation of 3D cell culture arrangements is more beneficial than traditional 2D culture in that it better recapitulates the native tissue biochemically and biomechanically. In addition, such an approach could potentially protect the tissue formed from necrosis and allow for more efficient implantation. In this review, we highlight the promise of brown adipocytes with a focus on brown adipogenic differentiation of stem cells using bioengineering approaches, along with potential challenges and opportunities that arise when considering the energy expenditure of BAT for prospective therapeutics.
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Affiliation(s)
- Andrea M Unser
- Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, 257 Fuller Road Albany, NY 12203, USA
| | - Yangzi Tian
- Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, 257 Fuller Road Albany, NY 12203, USA
| | - Yubing Xie
- Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, 257 Fuller Road Albany, NY 12203, USA.
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Abstract
Autologous fat grafting has been widely used in reconstructive and cosmetic surgery. Harvesting techniques play a key role in graft viability and outcomes. The authors investigated the effect of harvest pressure on adipocyte survival and viability of the surviving cells. Abdominal lipoaspiration was performed at high pressure (-760 mmHg) and low pressure (-250 mmHg) on three patients. Adipocyte survival and cell viability were measured. Adipocyte count immediately after harvest was 47 percent higher when aspirated at low pressure compared with high pressure. In addition, the cell viability was significantly higher at day 7 with low-pressure aspiration. The authors also describe a simple technique for aspirating at low pressures to obtain a controlled, consistent, reproducible, and good quality graft.
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Shoham N, Sasson AL, Lin FH, Benayahu D, Haj-Ali R, Gefen A. The mechanics of hyaluronic acid/adipic acid dihydrazide hydrogel: towards developing a vessel for delivery of preadipocytes to native tissues. J Mech Behav Biomed Mater 2013; 28:320-31. [PMID: 24021174 DOI: 10.1016/j.jmbbm.2013.08.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 07/28/2013] [Accepted: 08/05/2013] [Indexed: 11/28/2022]
Abstract
Promising treatment approaches in repairing tissue defects include implementation of regenerative medicine strategies, particularly delivery of preadipocytes to sites where adipose tissue damage needs to be repaired or where fat needs to be generated. In this study, we suggest that the injectable hyaluronic acid/adipic acid dihydrazide (HA/ADH) hydrogel may be an adipose-tissue-like material in terms of biological compatibility as well as mechanical behavior. First, we show that the hydrogel enables and supports growth, proliferation and differentiation of 3T3-L1 preadipocytes. Second, given that adipose tissue is a weight-bearing biological structure, we investigate the large deformation mechanical behavior of the hydrogel with and without embedded preadipocytes, by performing confined and unconfined compression tests and then calibrating a strain energy density (SED) function to the results. Four test groups were examined: (1) Hydrogel specimens right after the preparation without cells, (2) and (3) 3-days-cultured hydrogel specimens with and without cells, respectively, and (4) 6-days-cultured hydrogel specimens with cells. A one-term Ogden SED was found to adequately describe the hyperelastic behavior of the hydrogel specimens in all experimental groups. Importantly, we found that the mechanical properties of the hydrogel, when subjected to compression, are in good agreement with those of native adipose tissue, with the better fit occurring 3-6 days after preparation of the hydrogel. Third, computational finite element studies of the mechanical (stress-strain) behavior of the HA/ADH hydrogel when containing mature adipocytes indicated that the stiffnesses of the constructs were mildly affected by the presence of the adipocytes. Hence, we conclude that injectable HA/ADH hydrogel may serve as a vessel for protecting preadipocytes during, and at a short-term after delivery to native tissues, e.g. in research towards regenerative medicine in tissue reconstructions.
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Affiliation(s)
- Naama Shoham
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel
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