1
|
Wang G, Muñoz-Rojas AR, Spallanzani RG, Franklin RA, Benoist C, Mathis D. Adipose-tissue Treg cells restrain differentiation of stromal adipocyte precursors to promote insulin sensitivity and metabolic homeostasis. Immunity 2024; 57:1345-1359.e5. [PMID: 38692280 PMCID: PMC11188921 DOI: 10.1016/j.immuni.2024.04.002] [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: 05/23/2023] [Revised: 02/08/2024] [Accepted: 04/04/2024] [Indexed: 05/03/2024]
Abstract
Regulatory T (Treg) cells in epidydimal visceral adipose tissue (eVAT) of lean mice and humans regulate metabolic homeostasis. We found that constitutive or punctual depletion of eVAT-Treg cells reined in the differentiation of stromal adipocyte precursors. Co-culture of these precursors with conditional medium from eVAT-Treg cells limited their differentiation in vitro, suggesting a direct effect. Transcriptional comparison of adipocyte precursors, matured in the presence or absence of the eVAT-Treg-conditioned medium, identified the oncostatin-M (OSM) signaling pathway as a key distinction. Addition of OSM to in vitro cultures blocked the differentiation of adipocyte precursors, while co-addition of anti-OSM antibodies reversed the ability of the eVAT-Treg-conditioned medium to inhibit in vitro adipogenesis. Genetic depletion of OSM (specifically in Treg) cells or of the OSM receptor (specifically on stromal cells) strongly impaired insulin sensitivity and related metabolic indices. Thus, Treg-cell-mediated control of local progenitor cells maintains adipose tissue and metabolic homeostasis, a regulatory axis seemingly conserved in humans.
Collapse
Affiliation(s)
- Gang Wang
- Department of Immunology, Harvard Medical School, Boston, MA, USA
| | | | | | - Ruth A Franklin
- Department of Immunology, Harvard Medical School, Boston, MA, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
| | | | - Diane Mathis
- Department of Immunology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
2
|
Ige S, Alaoui K, Al-Dibouni A, Dallas ML, Cagampang FR, Sellayah D, Chantler PD, Boateng SY. Leptin-dependent differential remodeling of visceral and pericardial adipose tissue following chronic exercise and psychosocial stress. FASEB J 2024; 38:e23325. [PMID: 38117486 DOI: 10.1096/fj.202300269rrr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 11/06/2023] [Accepted: 11/08/2023] [Indexed: 12/21/2023]
Abstract
Obesity is driven by an imbalance between caloric intake and energy expenditure, causing excessive storage of triglycerides in adipose tissue at different sites around the body. Increased visceral adipose tissue (VAT) is associated with diabetes, while pericardial adipose tissue (PAT) is associated with cardiac pathology. Adipose tissue can expand either through cellular hypertrophy or hyperplasia, with the former correlating with decreased metabolic health in obesity. The aim of this study was to determine how VAT and PAT remodel in response to obesity, stress, and exercise. Here we have used the male obese Zucker rats, which carries two recessive fa alleles that result in the development of hyperphagia with reduced energy expenditure, resulting in morbid obesity and leptin resistance. At 9 weeks of age, a group of lean (Fa/Fa or Fa/fa) Zucker rats (LZR) and obese (fa/fa) Zucker rats (OZR) were treated with unpredictable chronic mild stress or exercise for 8 weeks. To determine the phenotype for PAT and VAT, tissue cellularity and gene expression were analyzed. Finally, leptin signaling was investigated further using cultured 3T3-derived adipocytes. Tissue cellularity was determined following hematoxylin and eosin (H&E) staining, while qPCR was used to examine gene expression. PAT adipocytes were significantly smaller than those from VAT and had a more beige-like appearance in both LZR and OZR. In the OZR group, VAT adipocyte cell size increased significantly compared with LZR, while PAT showed no difference. Exercise and stress resulted in a significant reduction in VAT cellularity in OZR, while PAT showed no change. This suggests that PAT cellularity does not remodel significantly compared with VAT. These data indicate that the extracellular matrix of PAT is able to remodel more readily than in VAT. In the LZR group, exercise increased insulin receptor substrate 1 (IRS1) in PAT but was decreased in the OZR group. In VAT, exercise decreased IRS1 in LZR, while increasing it in OZR. This suggests that in obesity, VAT is more responsive to exercise and subsequently becomes less insulin resistant compared with PAT. Stress increased PPAR-γ expression in the VAT but decreased it in the PAT in the OZR group. This suggests that in obesity, stress increases adipogenesis more significantly in the VAT compared with PAT. To understand the role of leptin signaling in adipose tissue remodeling mechanistically, JAK2 autophosphorylation was inhibited using 5 μM 1,2,3,4,5,6-hexabromocyclohexane (Hex) in cultured 3T3-derived adipocytes. Palmitate treatment was used to induce cellular hypertrophy. Hex blocked adipocyte hypertrophy in response to palmitate treatment but not the increase in lipid droplet size. These data suggest that leptin signaling is necessary for adipocyte cell remodeling, and its absence induces whitening. Taken together, our data suggest that leptin signaling is necessary for adipocyte remodeling in response to obesity, exercise, and psychosocial stress.
Collapse
Affiliation(s)
- Susan Ige
- Institute of Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Kaouthar Alaoui
- Institute of Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Alaa Al-Dibouni
- Institute of Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Mark L Dallas
- Institute of Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Felino R Cagampang
- Institute of Developmental Sciences, Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Dyan Sellayah
- Institute of Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| | - Paul D Chantler
- School of Medicine, West Virginia University, Morgantown, West Virginia, USA
| | - Samuel Y Boateng
- Institute of Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK
| |
Collapse
|
3
|
Fryklund C, Neuhaus M, Stenkula KG. Adipocyte traits limiting cellular insulin responsiveness and glucose transport. Am J Physiol Endocrinol Metab 2023; 325:E682-E687. [PMID: 37877798 PMCID: PMC10874650 DOI: 10.1152/ajpendo.00291.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/19/2023] [Accepted: 10/20/2023] [Indexed: 10/26/2023]
Abstract
Adipocyte dysfunction is a hallmark of systemic insulin resistance. Insulin-responsive glucose transporter 4 (GLUT4) is downregulated in the insulin resistant state, and cellular insulin responsiveness varies depending on fat depot origin and degree of adipose expansion. Here, we have resolved factors limiting cellular insulin responsiveness, by examining adipocyte function and traits related to glucose transport at the cellular level. Subcutaneous (inguinal) and visceral (epididymal) adipocytes were isolated from C57BL/6J mice fed either chow or high-fat diet. Cell size was determined using coulter counter method, glucose uptake and cytosolic volume were assessed using glucose tracer assays. Total and GLUT4 protein content expressions were determined by Western blot. We found that basal glucose uptake per cell was preserved independent of diet or fat depot origin. Insulin-stimulated glucose uptake per cell was sustained in visceral adipocytes but decreased with adipose expansion in subcutaneous adipocytes. In parallel, the cytosolic space and total protein increased proportionally to total cellular volumetric expansion in visceral, but not in subcutaneous, adipocytes, whereas GLUT4 content decreased exclusively in expanding subcutaneous adipocytes. Together, these data support the existence of distinct phenotypic adipocyte traits that could limit cellular insulin responsiveness. Potentially, these characteristics account for fat depot-specific differences related to glucose transport capacity.NEW & NOTEWORTHY This work illustrates that adipocyte characteristics related to fat depot origin rather than adipocyte size per se limit cellular insulin responsiveness and glucose uptake in male C57BL/6J mice. These findings contribute to the overall understanding of factors limiting adipocyte function and how adipose progression affects insulin response and glucose transport capacity differently in diverse fat depots. Future studies examining whether the proposed characteristics hold true in adipocytes derived from female mice or human origin are needed.
Collapse
Affiliation(s)
- Claes Fryklund
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Mathis Neuhaus
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Karin G Stenkula
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| |
Collapse
|
4
|
Neuhaus M, Fryklund C, Taylor H, Borreguero-Muñoz A, Kopietz F, Ardalani H, Rogova O, Stirrat L, Bremner SK, Spégel P, Bryant NJ, Gould GW, Stenkula KG. EHD2 regulates plasma membrane integrity and downstream insulin receptor signaling events. Mol Biol Cell 2023; 34:ar124. [PMID: 37703099 PMCID: PMC10846623 DOI: 10.1091/mbc.e23-03-0078] [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: 03/02/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/14/2023] Open
Abstract
Adipocyte dysfunction is a crucial driver of insulin resistance and type 2 diabetes. We identified EH domain-containing protein 2 (EHD2) as one of the most highly upregulated genes at the early stage of adipose-tissue expansion. EHD2 is a dynamin-related ATPase influencing several cellular processes, including membrane recycling, caveolae dynamics, and lipid metabolism. Here, we investigated the role of EHD2 in adipocyte insulin signaling and glucose transport. Using C57BL6/N EHD2 knockout mice under short-term high-fat diet conditions and 3T3-L1 adipocytes we demonstrate that EHD2 deficiency is associated with deterioration of insulin signal transduction and impaired insulin-stimulated GLUT4 translocation. Furthermore, we show that lack of EHD2 is linked with altered plasma membrane lipid and protein composition, reduced insulin receptor expression, and diminished insulin-dependent SNARE protein complex formation. In conclusion, these data highlight the importance of EHD2 for the integrity of the plasma membrane milieu, insulin receptor stability, and downstream insulin receptor signaling events, involved in glucose uptake and ultimately underscore its role in insulin resistance and obesity.
Collapse
Affiliation(s)
- Mathis Neuhaus
- Department of Experimental Medical Science, Lund University, 22184 Lund, Sweden
| | - Claes Fryklund
- Department of Experimental Medical Science, Lund University, 22184 Lund, Sweden
| | - Holly Taylor
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
| | | | - Franziska Kopietz
- Department of Experimental Medical Science, Lund University, 22184 Lund, Sweden
| | - Hamidreza Ardalani
- Department of Chemistry, Centre for Analysis and Synthesis, Lund University, 22241 Lund, Sweden
| | - Oksana Rogova
- Department of Chemistry, Centre for Analysis and Synthesis, Lund University, 22241 Lund, Sweden
| | - Laura Stirrat
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
| | - Shaun K. Bremner
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
| | - Peter Spégel
- Department of Chemistry, Centre for Analysis and Synthesis, Lund University, 22241 Lund, Sweden
| | - Nia J. Bryant
- Department of Biology and York Biomedical Research Institute, University of York, York YO10 5DD, UK
| | - Gwyn W. Gould
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
| | - Karin G. Stenkula
- Department of Experimental Medical Science, Lund University, 22184 Lund, Sweden
| |
Collapse
|
5
|
Saavedra-Peña RDM, Taylor N, Flannery C, Rodeheffer MS. Estradiol cycling drives female obesogenic adipocyte hyperplasia. Cell Rep 2023; 42:112390. [PMID: 37053070 PMCID: PMC10567995 DOI: 10.1016/j.celrep.2023.112390] [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: 07/26/2022] [Revised: 12/21/2022] [Accepted: 03/29/2023] [Indexed: 04/14/2023] Open
Abstract
White adipose tissue (WAT) distribution is sex dependent. Adipocyte hyperplasia contributes to WAT distribution in mice driven by cues in the tissue microenvironment, with females displaying hyperplasia in subcutaneous and visceral WAT, while males and ovariectomized females have visceral WAT (VWAT)-specific hyperplasia. However, the mechanism underlying sex-specific hyperplasia remains elusive. Here, transcriptome analysis in female mice shows that high-fat diet (HFD) induces estrogen signaling in adipocyte precursor cells (APCs). Analysis of APCs throughout the estrous cycle demonstrates increased proliferation only when proestrus (high estrogen) coincides with the onset of HFD feeding. We further show that estrogen receptor α (ERα) is required for this proliferation and that estradiol treatment at the onset of HFD feeding is sufficient to drive it. This estrous influence on APC proliferation leads to increased obesity driven by adipocyte hyperplasia. These data indicate that estrogen drives ERα-dependent obesogenic adipocyte hyperplasia in females, exacerbating obesity and contributing to the differential fat distribution between the sexes.
Collapse
Affiliation(s)
- Rocío Del M Saavedra-Peña
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA
| | - Natalia Taylor
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA
| | - Clare Flannery
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University, New Haven, CT 06520, USA; Section of Endocrinology and Metabolism, Yale University, New Haven, CT 06520, USA
| | - Matthew S Rodeheffer
- Department of Comparative Medicine, Yale University, New Haven, CT 06520, USA; Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06520, USA; Yale Center for Molecular and Systems Metabolism, Yale University, New Haven, CT 06520, USA; Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06520, USA.
| |
Collapse
|
6
|
Dickson E, Fryklund C, Soylu-Kucharz R, Sjögren M, Stenkula KG, Björkqvist M. Altered Adipocyte Cell Size Distribution Prior to Weight Loss in the R6/2 Model of Huntington's Disease. J Huntingtons Dis 2023; 12:253-266. [PMID: 37718850 DOI: 10.3233/jhd-230587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
BACKGROUND Metabolic alterations contribute to disease onset and prognosis of Huntington's disease (HD). Weight loss in the R6/2 mouse model of HD is a consistent feature, with onset in mid-to-late stage of disease. OBJECTIVE In the present study, we aimed to investigate molecular and functional changes in white adipose tissue (WAT) that occur at weight loss in R6/2 mice. We further elaborated on the effect of leptin-deficiency and early obesity in R6/2 mice. METHODS We performed analyses at 12 weeks of age; a time point that coincides with the start of weight loss in our R6/2 mouse colony. Gonadal (visceral) and inguinal (subcutaneous) WAT depot weights were monitored, as well as adipocyte size distribution. Response to isoprenaline-stimulated glycerol release and insulin-stimulated glucose uptake in adipocytes from gonadal WAT was assessed. RESULTS In R6/2 mice, WAT depot weights were comparable to wildtype (WT) mice, and the response to insulin and isoprenaline in gonadal adipocytes was unaltered. Leptin-deficient R6/2 mice exhibited distinct changes compared to leptin-deficient WT mice. At 12 weeks, female leptin-deficient R6/2 mice had reduced body weight accompanied by an increased proportion of smaller adipocytes, while in contrast; male mice displayed a shift towards larger adipocyte sizes without a significant body weight reduction at this timepoint. CONCLUSIONS We here show that there are early sex-specific changes in adipocyte cell size distribution in WAT of R6/2 mice and leptin-deficient R6/2 mice.
Collapse
Affiliation(s)
- Elna Dickson
- Brain Disease Biomarker Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Claes Fryklund
- Glucose Transport and Protein Trafficking, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Rana Soylu-Kucharz
- Brain Disease Biomarker Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Marie Sjögren
- Brain Disease Biomarker Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Karin G Stenkula
- Glucose Transport and Protein Trafficking, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Maria Björkqvist
- Brain Disease Biomarker Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
| |
Collapse
|
7
|
Simonsson C, Lövfors W, Bergqvist N, Nyman E, Gennemark P, Stenkula KG, Cedersund G. A multi-scale in silico mouse model for diet-induced insulin resistance. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
8
|
Casas B, Vilén L, Bauer S, Kanebratt KP, Wennberg Huldt C, Magnusson L, Marx U, Andersson TB, Gennemark P, Cedersund G. Integrated experimental-computational analysis of a HepaRG liver-islet microphysiological system for human-centric diabetes research. PLoS Comput Biol 2022; 18:e1010587. [PMID: 36260620 PMCID: PMC9621595 DOI: 10.1371/journal.pcbi.1010587] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 10/31/2022] [Accepted: 09/19/2022] [Indexed: 11/05/2022] Open
Abstract
Microphysiological systems (MPS) are powerful tools for emulating human physiology and replicating disease progression in vitro. MPS could be better predictors of human outcome than current animal models, but mechanistic interpretation and in vivo extrapolation of the experimental results remain significant challenges. Here, we address these challenges using an integrated experimental-computational approach. This approach allows for in silico representation and predictions of glucose metabolism in a previously reported MPS with two organ compartments (liver and pancreas) connected in a closed loop with circulating medium. We developed a computational model describing glucose metabolism over 15 days of culture in the MPS. The model was calibrated on an experiment-specific basis using data from seven experiments, where HepaRG single-liver or liver-islet cultures were exposed to both normal and hyperglycemic conditions resembling high blood glucose levels in diabetes. The calibrated models reproduced the fast (i.e. hourly) variations in glucose and insulin observed in the MPS experiments, as well as the long-term (i.e. over weeks) decline in both glucose tolerance and insulin secretion. We also investigated the behaviour of the system under hypoglycemia by simulating this condition in silico, and the model could correctly predict the glucose and insulin responses measured in new MPS experiments. Last, we used the computational model to translate the experimental results to humans, showing good agreement with published data of the glucose response to a meal in healthy subjects. The integrated experimental-computational framework opens new avenues for future investigations toward disease mechanisms and the development of new therapies for metabolic disorders. Microphysiological systems (MPS) are powerful tools to unravel biological knowledge underlying disease. MPS provide a physiologically relevant, human-based in vitro setting, which can potentially yield better translatability to humans than current animal models and traditional cell cultures. However, mechanistic interpretation and extrapolation of the experimental results to human outcome remain significant challenges. In this study, we confront these challenges using an integrated experimental-computational approach. We present a computational model describing glucose metabolism in a previously reported MPS integrating liver and pancreas. This MPS supports a homeostatic feedback loop between HepaRG/HHSteC spheroids and pancreatic islets, and allows for detailed investigations of mechanisms underlying type 2 diabetes in humans. We show that the computational model captures the complex dynamics of glucose-insulin regulation observed in the system, and can provide mechanistic insight into disease progression features, such as insulin resistance and β-cell dynamics. Furthermore, the computational model can explain key differences in temporal dynamics between MPS and human responses, and thus provides a tool for translating experimental insights into human outcome. The integrated experimental-computational framework opens new avenues for future investigations toward disease mechanisms and the development of new therapies for metabolic disorders.
Collapse
Affiliation(s)
- Belén Casas
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Liisa Vilén
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | | | - Kajsa P. Kanebratt
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Charlotte Wennberg Huldt
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Lisa Magnusson
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | | | - Tommy B. Andersson
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Peter Gennemark
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Gunnar Cedersund
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
- * E-mail:
| |
Collapse
|
9
|
Fryklund C, Neuhaus M, Morén B, Borreguero-Muñoz A, Lundmark R, Stenkula KG. Expansion of the Inguinal Adipose Tissue Depot Correlates With Systemic Insulin Resistance in C57BL/6J Mice. Front Cell Dev Biol 2022; 10:942374. [PMID: 36158197 PMCID: PMC9489915 DOI: 10.3389/fcell.2022.942374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
To accommodate surplus energy, the adipose tissue expands by increasing adipocyte size (hypertrophy) and number (hyperplasia). The presence of hypertrophic adipocytes is a key characteristic of adipose tissue dysfunction. High-fat diet (HFD) fed C57BL/6J mice are a commonly used model to study obesity and obesity-related complications. In the present study, we have characterized adipose plasticity, at both the cellular and tissue level, by examining the temporal development of systemic insulin resistance and adiposity in response to HFD-feeding for 4, 8, and 12 weeks (4w, 8w, and 12w). Within the same time frame, we examined systemic metabolic flexibility and adipose plasticity when switching from HFD- to chow-diet during the last 2 weeks of diet intervention (referred to as the reverse (REV) group: 4wREV (2w HFD+2w chow), 8wREV (6w HFD+2w chow), 12wREV (10w HFD+2w chow)). In response to HFD-feeding over time, the 12w group had impaired systemic insulin sensitivity compared to both the 4w and 8w groups, accompanied by an increase in hypertrophic inguinal adipocytes and liver triglycerides. After reversing from HFD- to chow-feeding, most parameters were completely restored to chow control levels for 4wREV and 8wREV groups. In contrast, the 12wREV group had a significantly increased number of hypertrophic adipocytes, liver triglycerides accumulation, and impaired systemic insulin sensitivity compared to chow-fed mice. Further, image analysis at the single-cell level revealed a cell-size dependent organization of actin filaments for all feeding conditions. Indeed, the impaired adipocyte size plasticity in the 12wREV group was accompanied by increased actin filamentation and reduced insulin-stimulated glucose uptake compared with chow-fed mice. In summary, these results demonstrate that the C57BL/6J HFD-feeding model has a large capacity to restore adipocyte cell size and systemic insulin sensitivity, and that a metabolic tipping point occurs between 8 and 12w of HFD-feeding where this plasticity deteriorates. We believe these findings provide substantial understanding of C57BL/6J mice as an obesity model, and that an increased pool of hypertrophic ING adipocytes could contribute to aggravated insulin resistance.
Collapse
Affiliation(s)
- Claes Fryklund
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- *Correspondence: Claes Fryklund,
| | - Mathis Neuhaus
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Björn Morén
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Integrative Medical Biology, Umeå University, Umeå, Sweden
| | | | | | - Karin G. Stenkula
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| |
Collapse
|
10
|
Kotowska D, Neuhaus M, Heyman-Lindén L, Morén B, Li S, Kryvokhyzha D, Berger K, Stenkula KG. Short-term lingonberry feeding is associated with decreased insulin levels and altered adipose tissue function in high-fat diet fed C57BL/6J mice. J Funct Foods 2022. [DOI: 10.1016/j.jff.2022.105125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
11
|
Lluch A, Veiga SR, Latorre J, Moreno-Navarrete JM, Bonifaci N, Nguyen VD, Zhou Y, Horing M, Liebisch G, Olkkonen VM, Llobet-Navas D, Thomas G, Rodriguez-Barrueco R, Fernández-Real JM, Kozma SC, Ortega FJ. A compound directed against S6K1 hampers fat mass expansion and mitigates diet-induced hepatosteatosis. JCI Insight 2022; 7:150461. [PMID: 35737463 PMCID: PMC9431684 DOI: 10.1172/jci.insight.150461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/15/2022] [Indexed: 11/24/2022] Open
Abstract
The ribosomal protein S6 kinase 1 (S6K1) is a relevant effector downstream of the mammalian target of rapamycin complex 1 (mTORC1), best known for its role in the control of lipid homeostasis. Consistent with this, mice lacking the S6k1 gene have a defect in their ability to induce the commitment of fat precursor cells to the adipogenic lineage, which contributes to a significant reduction of fat mass. Here, we assess the therapeutic blockage of S6K1 in diet-induced obese mice challenged with LY2584702 tosylate, a specific oral S6K1 inhibitor initially developed for the treatment of solid tumors. We show that diminished S6K1 activity hampers fat mass expansion and ameliorates dyslipidemia and hepatic steatosis, while modifying transcriptome-wide gene expression programs relevant for adipose and liver function. Accordingly, decreased mTORC1 signaling in fat (but increased in the liver) segregated with defective epithelial-mesenchymal transition and the impaired expression of Cd36 (coding for a fatty acid translocase) and Lgals1 (Galectin 1) in both tissues. All these factors combined align with reduced adipocyte size and improved lipidomic signatures in the liver, while hepatic steatosis and hypertriglyceridemia were improved in treatments lasting either 3 months or 6 weeks.
Collapse
Affiliation(s)
- Aina Lluch
- Department of Diabetes, Endocrinology, and Nutrition (UDEN), Girona Biomedical Research Institute (IDIBGI), Girona, Spain
| | - Sonia R Veiga
- Department of Aging & Metabolism, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain
| | - Jèssica Latorre
- Department of Diabetes, Endocrinology, and Nutrition (UDEN), Girona Biomedical Research Institute (IDIBGI), Girona, Spain
| | | | - Núria Bonifaci
- Breast Cancer and Systems Biology Unit, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain
| | - Van Dien Nguyen
- Division of Infection and Immunity, Cardiff University School of Medicine, Systems Immunity Research Institute, Cardiff University, Cardiff, United Kingdom
| | - You Zhou
- Systems Immunity Research Institute, Cardiff University, Cardiff, United Kingdom
| | - Marcus Horing
- Institute of Clinical Chemistry and Laboratory Medicine, Regensburg University Hospital, Regensburg, Germany
| | - Gerhard Liebisch
- Institute for Clinical Chemistry and Laboratory Medicine, Regensburg University Hospital, Regensburg, Germany
| | - Vesa M Olkkonen
- Biomedicum, Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - David Llobet-Navas
- Institute of Genetic Medicine, Newcastle University, Newastle, United Kingdom
| | - George Thomas
- Laboratory of Cancer Metabolism, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain
| | | | - José M Fernández-Real
- Department of Endocrinology, Girona Biomedical Research Institute (IDIBGI), Girona, Spain
| | - Sara C Kozma
- Laboratory of Cancer Metabolism, Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Spain
| | - Francisco J Ortega
- Department of Diabetes, Endocrinology, and Nutrition (UDEN), Girona Biomedical Research Institute (IDIBGI), Girona, Spain
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Yokota‐Nakagi N, Omoto S, Tazumi S, Kawakami M, Takamata A, Morimoto K. Estradiol replacement improves high-fat diet-induced insulin resistance in ovariectomized rats. Physiol Rep 2022; 10:e15193. [PMID: 35238495 PMCID: PMC8892597 DOI: 10.14814/phy2.15193] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/08/2022] [Accepted: 01/10/2022] [Indexed: 05/15/2023] Open
Abstract
The role of 17β-estradiol (E2) in high-fat diet (HFD)-induced alteration of the protein kinase B (Akt) signaling pathway in ovariectomized (OVX) rats is unclear. Therefore, we examined whether chronic estrogen replacement restores HFD-induced impairment in insulin sensitivity by its effects concomitant with alterations in the Akt isoform 2 (Akt2) and Akt substrate of 160 kDa (AS160) phosphorylation in muscles of OVX rats. Nine-week-old female Wistar rats underwent ovariectomy under anesthesia; after 4 weeks, subcutaneous implantation of either E2 or placebo (PL) pellets was performed, and HFD feeding was initiated. Intravenous glucose tolerance tests were performed to assess insulin sensitivity. Following insulin injection into rats' portal vein, the liver and gastrocnemius muscle were dissected for insulin signaling analysis. We observed that HFD increased energy intake and body weight in the PL group; however, it was temporarily decreased in the E2 group. Adipose tissue accumulation was larger in HFD-fed rats than in normal chow diet (NCD)-fed rats in the PL group; however, this difference was not observed in the E2 group. HFD reduced insulin sensitivity in the PL group only. In vivo insulin stimulation increased Akt2 phosphorylation in the muscles of NCD-fed rats in both groups. In contrast, HFD affected insulin-stimulated phosphorylation of Akt2 and AS160 in the muscles of rats in the PL group but not in the E2 group. Our data suggest that E2 replacement improves HFD-induced insulin resistance, and this effect is accompanied by the alterations in the Akt2 and AS160 phosphorylation in insulin-stimulated muscles of OVX rats.
Collapse
Affiliation(s)
- Naoko Yokota‐Nakagi
- Department of Environmental HealthFaculty of Human Life and EnvironmentNara Women’s UniversityNaraJapan
- Department of Health and NutritionFaculty of Health ScienceKyoto Koka Women’s UniversityKyotoJapan
| | - Sayo Omoto
- Department of Environmental HealthFaculty of Human Life and EnvironmentNara Women’s UniversityNaraJapan
| | - Shoko Tazumi
- Department of Environmental HealthFaculty of Human Life and EnvironmentNara Women’s UniversityNaraJapan
| | - Mizuho Kawakami
- Department of Environmental HealthFaculty of Human Life and EnvironmentNara Women’s UniversityNaraJapan
| | - Akira Takamata
- Department of Environmental HealthFaculty of Human Life and EnvironmentNara Women’s UniversityNaraJapan
| | - Keiko Morimoto
- Department of Environmental HealthFaculty of Human Life and EnvironmentNara Women’s UniversityNaraJapan
- Department of Health and NutritionFaculty of Health ScienceKyoto Koka Women’s UniversityKyotoJapan
| |
Collapse
|
14
|
Fryklund C, Morén B, Shah S, Grossi M, Degerman E, Matthaeus C, Stenkula KG. EH Domain-Containing 2 Deficiency Restricts Adipose Tissue Expansion and Impairs Lipolysis in Primary Inguinal Adipocytes. Front Physiol 2021; 12:740666. [PMID: 34630160 PMCID: PMC8497890 DOI: 10.3389/fphys.2021.740666] [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: 07/13/2021] [Accepted: 08/25/2021] [Indexed: 11/21/2022] Open
Abstract
Lipid uptake can be facilitated via caveolae, specific plasma membrane invaginations abundantly expressed in adipocytes. The dynamin-related protein EH domain-containing 2 (EHD2) stabilizes caveolae at the cell surface. Here, we have examined the importance of EHD2 for lipid handling using primary adipocytes isolated from EHD2 knockout (Ehd2−/−) C57BL6/N mice. Following high-fat diet (HFD) feeding, we found a clear impairment of epididymal, but not inguinal, adipose tissue expansion in Ehd2−/− compared with Ehd2+/+ (WT) mice. Cell size distribution analysis revealed that Ehd2−/− mice had a lower proportion of small adipocytes, and an accumulation of medium-sized adipocytes in both epididymal and inguinal adipose tissue. Further, PPARγ activity, FABP4 and caveolin-1 expression were decreased in adipocytes isolated from Ehd2−/− mice. Inguinal adipocytes isolated from Ehd2−/− mice displayed reduced lipolysis in response to beta adrenergic receptor agonist, which was associated with reduced phosphorylation of perilipin-1 and hormone sensitive lipase (HSL). This impairment could not be rescued using a cAMP analog, indicating that impaired lipolysis in Ehd2−/− primary adipocytes likely occurs at the level of, or downstream of, protein kinase A (PKA). Altogether, these findings pinpoint the importance of EHD2 for maintained intracellular lipid metabolism, and emphasize differences in mechanisms regulating lipid handling in various adipose-tissue depots.
Collapse
Affiliation(s)
- Claes Fryklund
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Björn Morén
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Shrenika Shah
- School of Biomedical, Nutritional and Sport Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Mario Grossi
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Eva Degerman
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Claudia Matthaeus
- National Heart, Lung and Blood Institute, NIH, Bethesda, MD, United States
| | - Karin G Stenkula
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| |
Collapse
|
15
|
Sakane S, Hikita H, Shirai K, Myojin Y, Sasaki Y, Kudo S, Fukumoto K, Mizutani N, Tahata Y, Makino Y, Yamada R, Kodama T, Sakamori R, Tatsumi T, Takehara T. White Adipose Tissue Autophagy and Adipose-Liver Crosstalk Exacerbate Nonalcoholic Fatty Liver Disease in Mice. Cell Mol Gastroenterol Hepatol 2021; 12:1683-1699. [PMID: 34303881 PMCID: PMC8551788 DOI: 10.1016/j.jcmgh.2021.07.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 07/06/2021] [Accepted: 07/08/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Although nonalcoholic fatty liver disease (NAFLD) is closely associated with obesity, the role of adipose tissue in NAFLD is not well-understood. Because autophagy has been reported to be involved in the degradation of lipid droplets, we investigated the role of adipose tissue autophagy in the liver pathogenesis of NAFLD. METHODS C57BL/6J mice and adipocyte-specific Atg7-knockout mice (Adipoq-Atg7 KO mice) were fed a high-fat diet (HFD). RESULTS HFD feeding for up to 4 months increased both inguinal and epididymal white adipose tissue (iWAT and eWAT, respectively; the former represents subcutaneous fat, and the latter represents visceral fat) in mice. After HFD feeding, autophagy flux in both types of white adipose tissue was increased, and the levels of Rubicon, a negative autophagy regulator, were decreased, suggesting autophagy promotion. Adipoq-Atg7 KO mice exhibited suppressed autophagy in both iWAT and eWAT. Adipocyte-specific Atg7 KO enhanced HFD-induced iWAT hypertrophy. On the other hand, eWAT levels in Adipoq-Atg7 KO mice were increased after 1 month of HFD feeding but decreased after 4 months of HFD feeding compared with those in wild-type controls. Cleaved caspase 3 and JNK pathway protein expression in eWAT was increased without cytokine elevation in Adipoq-Atg7 KO mice fed an HFD compared with wild-type mice fed an HFD. Adipocyte-specific Atg7 KO decreased serum free fatty acid levels and ameliorated HFD-induced steatosis, liver inflammation, and fibrosis. CONCLUSIONS Autophagy was enhanced in the white adipose tissues of mice fed an HFD. Autophagy inhibition in white adipose tissues ameliorated the liver pathology of NAFLD via adipose-liver crosstalk.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Tetsuo Takehara
- Correspondence Address correspondence to: Tetsuo Takehara, MD, PhD, 2-2 Yamadaoka, Suita, Osaka, 565-0871 Japan. fax: +81-6-6879-3629.
| |
Collapse
|
16
|
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.
Collapse
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.
| |
Collapse
|
17
|
Beneficial effect on serum cholesterol levels, but not glycaemic regulation, after replacing SFA with PUFA for 3 d: a randomised crossover trial. Br J Nutr 2020; 125:915-925. [PMID: 32873354 PMCID: PMC7944393 DOI: 10.1017/s0007114520003402] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Replacing intake of SFA with PUFA reduces serum cholesterol levels and CVD risk. The effect on glycaemic regulation is, however, less clear. The main objective of the present study was to investigate the short-term effect of replacing dietary SFA with PUFA on glycaemic regulation. Seventeen healthy, normal-weight participants completed a 25-d double-blind, randomised and controlled two-period crossover study. Participants were allocated to either interventions with PUFA products or SFA products (control) in a random order for three consecutive days, separated by a 1·5-week washout period between the intervention periods. Glucose, insulin and TAG were measured before and after an oral glucose tolerance test. In addition, fasting total cholesterol, NEFA and plasma total fatty acid profile were measured before and after the 3-d interventions. Fasting and postprandial glucose, insulin, and TAG levels and fasting levels of NEFA and plasma fatty acid profile did not differ between the groups. However, replacing dietary SFA with PUFA significantly reduced total cholesterol levels by 8 % after 3 d (P = 0·002). Replacing dietary SFA with PUFA for only 3 d has beneficial cardio-metabolic effects by reducing cholesterol levels in healthy individuals.
Collapse
|
18
|
Pålbrink AK, Kopietz F, Morén B, In 't Zandt R, Kalinec F, Stenkula K, Göransson O, Holm C, Magnusson M, Degerman E. Inner ear is a target for insulin signaling and insulin resistance: evidence from mice and auditory HEI-OC1 cells. BMJ Open Diabetes Res Care 2020; 8:8/1/e000820. [PMID: 32238362 PMCID: PMC7170413 DOI: 10.1136/bmjdrc-2019-000820] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 02/14/2020] [Accepted: 03/03/2020] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE The mechanisms underlying the association between diabetes and inner ear dysfunction are not known yet. The aim of the present study is to evaluate the impact of obesity/insulin resistance on inner ear fluid homeostasis in vivo, and to investigate whether the organ of Corti could be a target tissue for insulin signaling using auditory House Ear Institute-Organ of Corti 1 (HEI-OC1) cells as an in vitro model. METHODS High fat diet (HFD) fed C57BL/6J mice were used as a model to study the impact of insulin resistance on the inner ear. In one study, 12 C57BL/6J mice were fed either control diet or HFD and the size of the inner ear endolymphatic fluid compartment (EFC) was measured after 30 days using MRI and gadolinium contrast as a read-out. In another study, the size of the inner ear EFC was evaluated in eight C57BL/6J mice both before and after HFD feeding, with the same techniques. HEI-OC1 auditory cells were used as a model to investigate insulin signaling in organ of Corti cells. RESULTS HFD feeding induced an expansion of the EFC in C57BL/6J mice, a hallmark of inner ear dysfunction. Insulin also induced phosphorylation of protein kinase B (PKB/Akt) at Ser473, in a PI3-kinase-dependent manner. The phosphorylation of PKB was inhibited by isoproterenol and IBMX, a general phosphodiesterase (PDE) inhibitor. PDE1B, PDE4D and the insulin-sensitive PDE3B were found expressed and catalytically active in HEI-OC1 cells. Insulin decreased and AICAR, an activator of AMP-activated protein kinase, increased the phosphorylation at the inhibitory Ser79 of acetyl-CoA carboxylase, the rate-limiting enzyme in de novo lipogenesis. Furthermore, the activity of hormone-sensitive lipase, the rate-limiting enzyme in lipolysis, was detected in HEI-OC1 cells. CONCLUSIONS The organ of Corti could be a target tissue for insulin action, and inner ear insulin resistance might contribute to the association between diabetes and inner ear dysfunction.
Collapse
Affiliation(s)
- Ann-Ki Pålbrink
- Experimental Medical Science, Section for Diabetes, Metabolism and Endocrinology, Lund University Diabetes Centre, Lund University, Lund, Sweden
| | - Franziska Kopietz
- Experimental Medical Science, Section for Diabetes, Metabolism and Endocrinology, Lund University Diabetes Centre, Lund University, Lund, Sweden
| | - Björn Morén
- Experimental Medical Science, Section for Diabetes, Metabolism and Endocrinology, Lund University Diabetes Centre, Lund University, Lund, Sweden
| | - René In 't Zandt
- Lund University Bioimaging Center, Lund University, Lund, Sweden
| | - Federico Kalinec
- Department of Head and Neck Surgery, Laboratory of Auditory Cell Biology, David Geffen Schoolof Medicin, UCLA, Los Angeles, California, USA
| | - Karin Stenkula
- Experimental Medical Science, Section for Diabetes, Metabolism and Endocrinology, Lund University Diabetes Centre, Lund University, Lund, Sweden
| | - Olga Göransson
- Experimental Medical Science, Section for Diabetes, Metabolism and Endocrinology, Lund University Diabetes Centre, Lund University, Lund, Sweden
| | - Cecilia Holm
- Experimental Medical Science, Section for Diabetes, Metabolism and Endocrinology, Lund University Diabetes Centre, Lund University, Lund, Sweden
| | - Måns Magnusson
- Department of Clinical Science, Section for Otorhinolaryngology, Lund University & Skåne University Hospital, Lund, Sweden
| | - Eva Degerman
- Experimental Medical Science, Section for Diabetes, Metabolism and Endocrinology, Lund University Diabetes Centre, Lund University, Lund, Sweden
| |
Collapse
|
19
|
Fryklund C, Borg M, Svensson T, Schumacher S, Negoita F, Morén B, Stenkula KG. Impaired glucose transport in inguinal adipocytes after short-term high-sucrose feeding in mice. J Nutr Biochem 2020; 78:108338. [PMID: 32004930 DOI: 10.1016/j.jnutbio.2019.108338] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 11/14/2019] [Accepted: 12/20/2019] [Indexed: 02/07/2023]
Abstract
Diets enriched in sucrose severely impair metabolic regulation and are associated with obesity, insulin resistance and glucose intolerance. In the current study, we investigated the effect of 4 weeks high-sucrose diet (HSD) feeding in C57BL6/J mice, with specific focus on adipocyte function. Mice fed HSD had slightly increased adipose tissue mass but displayed similar hepatic triglycerides, glucose and insulin levels, and glucose clearance capacity as chow-fed mice. Interestingly, we found adipose depot-specific differences, where both the non- and insulin-stimulated glucose transports were markedly impaired in primary adipocytes isolated from the inguinal fat depot from HSD-fed mice. This was accompanied by decreased protein levels of both GLUT4 and AS160. A similar but much less pronounced trend was observed in the retroperitoneal depot. In contrast, both GLUT4 expression and insulin-stimulated glucose uptake were preserved in adipocytes isolated from epididymal adipose tissue with HSD. Further, we found a slight shift in cell size distribution towards larger cells with HSD and a significant decrease of ACC and PGC-1α expression in the inguinal adipose tissue depot. Moreover, fructose alone was sufficient to decrease GLUT4 expression in cultured, mature adipocytes. Altogether, we demonstrate that short-term HSD feeding has deleterious impact on insulin response and glucose transport in the inguinal adipose tissue depot, specifically. These changes occur before the onset of systemic glucose dysmetabolism and therefore could provide a mechanistic link to overall impaired energy metabolism reported after prolonged HSD feeding, alone or in combination with HFD.
Collapse
Affiliation(s)
- Claes Fryklund
- Lund University, Department of Experimental Medical Science, 221 84 Lund, Sweden
| | - Madelene Borg
- Lund University, Department of Experimental Medical Science, 221 84 Lund, Sweden
| | - Tobias Svensson
- Lund University, Department of Experimental Medical Science, 221 84 Lund, Sweden
| | - Sara Schumacher
- Lund University, Department of Experimental Medical Science, 221 84 Lund, Sweden
| | - Florentina Negoita
- Lund University, Department of Experimental Medical Science, 221 84 Lund, Sweden
| | - Björn Morén
- Lund University, Department of Experimental Medical Science, 221 84 Lund, Sweden
| | - Karin G Stenkula
- Lund University, Department of Experimental Medical Science, 221 84 Lund, Sweden.
| |
Collapse
|
20
|
Hansson B, Morén B, Fryklund C, Vliex L, Wasserstrom S, Albinsson S, Berger K, Stenkula KG. Adipose cell size changes are associated with a drastic actin remodeling. Sci Rep 2019; 9:12941. [PMID: 31506540 PMCID: PMC6736966 DOI: 10.1038/s41598-019-49418-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 08/23/2019] [Indexed: 12/21/2022] Open
Abstract
Adipose tissue plays a major role in regulating whole-body insulin sensitivity and energy metabolism. To accommodate surplus energy, the tissue rapidly expands by increasing adipose cell size (hypertrophy) and cell number (hyperplasia). Previous studies have shown that enlarged, hypertrophic adipocytes are less responsive to insulin, and that adipocyte size could serve as a predictor for the development of type 2 diabetes. In the present study, we demonstrate that changes in adipocyte size correlate with a drastic remodeling of the actin cytoskeleton. Expansion of primary adipocytes following 2 weeks of high-fat diet (HFD)-feeding in C57BL6/J mice was associated with a drastic increase in filamentous (F)-actin as assessed by fluorescence microscopy, increased Rho-kinase activity, and changed expression of actin-regulating proteins, favoring actin polymerization. At the same time, increased cell size was associated with impaired insulin response, while the interaction between the cytoskeletal scaffolding protein IQGAP1 and insulin receptor substrate (IRS)-1 remained intact. Reversed feeding from HFD to chow restored cell size, insulin response, expression of actin-regulatory proteins and decreased the amount of F-actin filaments. Together, we report a drastic cytoskeletal remodeling during adipocyte expansion, a process which could contribute to deteriorating adipocyte function.
Collapse
Affiliation(s)
- Björn Hansson
- Lund University, Department of Experimental Medical Science, Lund, Sweden
| | - Björn Morén
- Lund University, Department of Experimental Medical Science, Lund, Sweden
| | - Claes Fryklund
- Lund University, Department of Experimental Medical Science, Lund, Sweden
| | - Lars Vliex
- Lund University, Department of Experimental Medical Science, Lund, Sweden.,Maastricht University, Faculty of Health, Medicine and Life Sciences, Maastricht, The Netherlands
| | | | | | - Karin Berger
- Lund University, Department of Experimental Medical Science, Lund, Sweden
| | - Karin G Stenkula
- Lund University, Department of Experimental Medical Science, Lund, Sweden.
| |
Collapse
|
21
|
Morén B, Hansson B, Negoita F, Fryklund C, Lundmark R, Göransson O, Stenkula KG. EHD2 regulates adipocyte function and is enriched at cell surface-associated lipid droplets in primary human adipocytes. Mol Biol Cell 2019; 30:1147-1159. [PMID: 30811273 PMCID: PMC6724522 DOI: 10.1091/mbc.e18-10-0680] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Adipocytes play a central role in energy balance, and dysfunctional adipose tissue severely affects systemic energy homeostasis. The ATPase EH domain–containing 2 (EHD2) has previously been shown to regulate caveolae, plasma membrane-specific domains that are involved in lipid uptake and signal transduction. Here, we investigated the role of EHD2 in adipocyte function. We demonstrate that EHD2 protein expression is highly up-regulated at the onset of triglyceride accumulation during adipocyte differentiation. Small interfering RNA–mediated EHD2 silencing affected the differentiation process and impaired insulin sensitivity, lipid storage capacity, and lipolysis. Fluorescence imaging revealed localization of EHD2 to caveolae, close to cell surface–associated lipid droplets in primary human adipocytes. These lipid droplets stained positive for glycerol transporter aquaporin 7 and phosphorylated perilipin-1 following adrenergic stimulation. Further, EHD2 overexpression in human adipocytes increased the lipolytic signaling and suppressed the activity of transcription factor PPARγ. Overall, these data suggest that EHD2 plays a key role for adipocyte function.
Collapse
Affiliation(s)
- Björn Morén
- Department of Experimental Medical Science, Lund University, 223 84 Lund, Sweden
| | - Björn Hansson
- Department of Experimental Medical Science, Lund University, 223 84 Lund, Sweden
| | - Florentina Negoita
- Department of Experimental Medical Science, Lund University, 223 84 Lund, Sweden
| | - Claes Fryklund
- Department of Experimental Medical Science, Lund University, 223 84 Lund, Sweden
| | - Richard Lundmark
- Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Olga Göransson
- Department of Experimental Medical Science, Lund University, 223 84 Lund, Sweden
| | - Karin G Stenkula
- Department of Experimental Medical Science, Lund University, 223 84 Lund, Sweden
| |
Collapse
|