1
|
Hagberg CE, Spalding KL. White adipocyte dysfunction and obesity-associated pathologies in humans. Nat Rev Mol Cell Biol 2024; 25:270-289. [PMID: 38086922 DOI: 10.1038/s41580-023-00680-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2023] [Indexed: 02/10/2024]
Abstract
The prevalence of obesity and associated chronic diseases continues to increase worldwide, negatively impacting on societies and economies. Whereas the association between excess body weight and increased risk for developing a multitude of diseases is well established, the initiating mechanisms by which weight gain impairs our metabolic health remain surprisingly contested. In order to better address the myriad of disease states associated with obesity, it is essential to understand adipose tissue dysfunction and develop strategies for reinforcing adipocyte health. In this Review we outline the diverse physiological functions and pathological roles of human white adipocytes, examining our current knowledge of why white adipocytes are vital for systemic metabolic control, yet poorly adapted to our current obesogenic environment.
Collapse
Affiliation(s)
- Carolina E Hagberg
- Division of Cardiovascular Medicine, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Kirsty L Spalding
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
2
|
Shi L, Yang J, Tao Z, Zheng L, Bui T, Alonso R, Yue F, Cheng Z. Loss of FoxO1 activates an alternate mechanism of mitochondrial quality control for healthy adipose browning. Clin Sci (Lond) 2024; 138:371-385. [PMID: 38469619 PMCID: PMC10932742 DOI: 10.1042/cs20230973] [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: 08/25/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/13/2024]
Abstract
Browning of white adipose tissue is hallmarked by increased mitochondrial density and metabolic improvements. However, it remains largely unknown how mitochondrial turnover and quality control are regulated during adipose browning. In the present study, we found that mice lacking adipocyte FoxO1, a transcription factor that regulates autophagy, adopted an alternate mechanism of mitophagy to maintain mitochondrial turnover and quality control during adipose browning. Post-developmental deletion of adipocyte FoxO1 (adO1KO) suppressed Bnip3 but activated Fundc1/Drp1/OPA1 cascade, concurrent with up-regulation of Atg7 and CTSL. In addition, mitochondrial biogenesis was stimulated via the Pgc1α/Tfam pathway in adO1KO mice. These changes were associated with enhanced mitochondrial homeostasis and metabolic health (e.g., improved glucose tolerance and insulin sensitivity). By contrast, silencing Fundc1 or Pgc1α reversed the changes induced by silencing FoxO1, which impaired mitochondrial quality control and function. Ablation of Atg7 suppressed mitochondrial turnover and function, causing metabolic disorder (e.g., impaired glucose tolerance and insulin sensitivity), regardless of elevated markers of adipose browning. Consistently, suppression of autophagy via CTSL by high-fat diet was associated with a reversal of adO1KO-induced benefits. Our data reveal a unique role of FoxO1 in coordinating mitophagy receptors (Bnip3 and Fundc1) for a fine-tuned mitochondrial turnover and quality control, underscoring autophagic clearance of mitochondria as a prerequisite for healthy browning of adipose tissue.
Collapse
Affiliation(s)
- Limin Shi
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611, U.S.A
- Interdisciplinary Nutritional Sciences Doctoral Program, Center for Nutritional Sciences, University of Florida, Gainesville, FL 32611, U.S.A
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32610, U.S.A
| | - Jinying Yang
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611, U.S.A
- Interdisciplinary Nutritional Sciences Doctoral Program, Center for Nutritional Sciences, University of Florida, Gainesville, FL 32611, U.S.A
| | - Zhipeng Tao
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, U.S.A
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, U.S.A
| | - Louise Zheng
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Tyler F. Bui
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611, U.S.A
| | - Ramon L. Alonso
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611, U.S.A
| | - Feng Yue
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, U.S.A
| | - Zhiyong Cheng
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611, U.S.A
- Interdisciplinary Nutritional Sciences Doctoral Program, Center for Nutritional Sciences, University of Florida, Gainesville, FL 32611, U.S.A
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32610, U.S.A
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA 24061, U.S.A
| |
Collapse
|
3
|
Guerrier L, Malpuech-Brugère C, Richard R, Touron J. Mitochondrial Function in Healthy Human White Adipose Tissue: A Narrative Review. Nutrients 2023; 15:4430. [PMID: 37892505 PMCID: PMC10609723 DOI: 10.3390/nu15204430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/10/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
As ¾ of the global population either have excess or insufficient fat, it has become increasingly critical to understand the functions and dysfunctions of adipose tissue (AT). AT serves as a key organ in energy metabolism, and recently, attention has been focused on white AT, particularly its mitochondria, as the literature evidence links their functions to adiposity. This narrative review provides an overview of mitochondrial functionality in human white AT. Firstly, it is noteworthy that the two primary AT depots, subcutaneous AT (scAT) and visceral AT (vAT), exhibit differences in mitochondrial density and activity. Notably, vAT tends to have a higher mitochondrial activity compared to scAT. Subsequently, studies have unveiled a negative correlation between mitochondrial activity and body mass index (BMI), indicating that obesity is associated with a lower mitochondrial function. While the impact of exercise on AT mitochondria remains uncertain, dietary interventions have demonstrated varying effects on AT mitochondria. This variability holds promise for the modulation of AT mitochondrial activity. In summary, AT mitochondria exert a significant influence on health outcomes and can be influenced by factors such as obesity and dietary interventions. Understanding the mechanisms underlying these responses can offer potential insights into managing conditions related to AT and overall health.
Collapse
Affiliation(s)
- Lisa Guerrier
- Unité de Nutrition Humaine, Université Clermont Auvergne, INRAe, 63000 Clermont-Ferrand, France; (C.M.-B.); (R.R.); (J.T.)
| | - Corinne Malpuech-Brugère
- Unité de Nutrition Humaine, Université Clermont Auvergne, INRAe, 63000 Clermont-Ferrand, France; (C.M.-B.); (R.R.); (J.T.)
- CRNH Auvergne, 63000 Clermont-Ferrand, France
| | - Ruddy Richard
- Unité de Nutrition Humaine, Université Clermont Auvergne, INRAe, 63000 Clermont-Ferrand, France; (C.M.-B.); (R.R.); (J.T.)
- CRNH Auvergne, 63000 Clermont-Ferrand, France
- CHU Clermont-Ferrand, 63000 Clermont-Ferrand, France
| | - Julianne Touron
- Unité de Nutrition Humaine, Université Clermont Auvergne, INRAe, 63000 Clermont-Ferrand, France; (C.M.-B.); (R.R.); (J.T.)
- CRNH Auvergne, 63000 Clermont-Ferrand, France
| |
Collapse
|
4
|
Shi L, Tao Z, Zheng L, Yang J, Hu X, Scott K, de Kloet A, Krause E, Collins JF, Cheng Z. FoxO1 regulates adipose transdifferentiation and iron influx by mediating Tgfβ1 signaling pathway. Redox Biol 2023; 63:102727. [PMID: 37156218 DOI: 10.1016/j.redox.2023.102727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 04/24/2023] [Accepted: 04/30/2023] [Indexed: 05/10/2023] Open
Abstract
Adipose plasticity is critical for metabolic homeostasis. Adipocyte transdifferentiation plays an important role in adipose plasticity, but the molecular mechanism of transdifferentiation remains incompletely understood. Here we show that the transcription factor FoxO1 regulates adipose transdifferentiation by mediating Tgfβ1 signaling pathway. Tgfβ1 treatment induced whitening phenotype in beige adipocytes, reducing UCP1 and mitochondrial capacity and enlarging lipid droplets. Deletion of adipose FoxO1 (adO1KO) dampened Tgfβ1 signaling by downregulating Tgfbr2 and Smad3 and induced browning of adipose tissue in mice, increasing UCP1 and mitochondrial content and activating metabolic pathways. Silencing FoxO1 also abolished the whitening effect of Tgfβ1 on beige adipocytes. The adO1KO mice exhibited a significantly higher energy expenditure, lower fat mass, and smaller adipocytes than the control mice. The browning phenotype in adO1KO mice was associated with an increased iron content in adipose tissue, concurrent with upregulation of proteins that facilitate iron uptake (DMT1 and TfR1) and iron import into mitochondria (Mfrn1). Analysis of hepatic and serum iron along with hepatic iron-regulatory proteins (ferritin and ferroportin) in the adO1KO mice revealed an adipose tissue-liver crosstalk that meets the increased iron requirement for adipose browning. The FoxO1-Tgfβ1 signaling cascade also underlay adipose browning induced by β3-AR agonist CL316243. Our study provides the first evidence of a FoxO1-Tgfβ1 axis in the regulation of adipose browning-whitening transdifferentiation and iron influx, which sheds light on the compromised adipose plasticity in conditions of dysregulated FoxO1 and Tgfβ1 signaling.
Collapse
Affiliation(s)
- Limin Shi
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, 32611, USA; Interdisciplinary Nutritional Sciences Doctoral Program, Center for Nutritional Sciences, University of Florida, Gainesville, FL, 32611, USA; Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, 32610, USA
| | - Zhipeng Tao
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA, 24061, USA; Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Louise Zheng
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Jinying Yang
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, 32611, USA; Interdisciplinary Nutritional Sciences Doctoral Program, Center for Nutritional Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Xinran Hu
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, 32611, USA
| | - Karen Scott
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, 32610, USA; Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL32610, USA
| | - Annette de Kloet
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, 32610, USA; Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, 32610, USA
| | - Eric Krause
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, 32610, USA; Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL32610, USA
| | - James F Collins
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, 32611, USA; Interdisciplinary Nutritional Sciences Doctoral Program, Center for Nutritional Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Zhiyong Cheng
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, 32611, USA; Interdisciplinary Nutritional Sciences Doctoral Program, Center for Nutritional Sciences, University of Florida, Gainesville, FL, 32611, USA; Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL, 32610, USA; Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA, 24061, USA.
| |
Collapse
|
5
|
Nicholls DG, Brand MD. A critical assessment of the role of creatine in brown adipose tissue thermogenesis. Nat Metab 2023; 5:21-28. [PMID: 36624158 DOI: 10.1038/s42255-022-00718-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/30/2022] [Indexed: 01/11/2023]
Abstract
Brown adipose tissue is specialized for non-shivering thermogenesis, combining lipolysis with an extremely active mitochondrial electron transport chain and a unique regulated uncoupling protein, UCP1, allowing unrestricted respiration. Current excitement focuses on the presence of brown adipose tissue in humans and the possibility that it may contribute to diet-induced thermogenesis, countering obesity and obesity-related disease as well as protecting cardio-metabolic health. In common with other tissues displaying a high, variable respiration, the tissue possesses a creatine pool and mitochondrial and cytosolic creatine kinase isoforms. Genetic and pharmacological manipulation of these components have pleiotropic effects that appear to influence diet- and cold-induced metabolism in vivo and modeled in vitro. These findings have been used to advance the concept of a UCP1-independent diet-induced thermogenic mechanism based on a dissipative hydrolysis of phosphocreatine in beige and brown adipose tissue. Here we review the in vivo and in vitro experimental basis for this hypothesis, and explore alternative explanations. We conclude that there is currently no convincing evidence for a significant futile creatine cycle in these tissues.
Collapse
|
6
|
Börgeson E, Boucher J, Hagberg CE. Of mice and men: Pinpointing species differences in adipose tissue biology. Front Cell Dev Biol 2022; 10:1003118. [PMID: 36187476 PMCID: PMC9521710 DOI: 10.3389/fcell.2022.1003118] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
The prevalence of obesity and metabolic diseases continues to rise, which has led to an increased interest in studying adipose tissue to elucidate underlying disease mechanisms. The use of genetic mouse models has been critical for understanding the role of specific genes for adipose tissue function and the tissue’s impact on other organs. However, mouse adipose tissue displays key differences to human fat, which has led, in some cases, to the emergence of some confounding concepts in the adipose field. Such differences include the depot-specific characteristics of visceral and subcutaneous fat, and divergences in thermogenic fat phenotype between the species. Adipose tissue characteristics may therefore not always be directly compared between species, which is important to consider when setting up new studies or interpreting results. This mini review outlines our current knowledge about the cell biological differences between human and mouse adipocytes and fat depots, highlighting some examples where inadequate knowledge of species-specific differences can lead to confounding results, and presenting plausible anatomic explanations that may underlie the differences. The article thus provides critical insights and guidance for researchers working primarily with only human or mouse fat tissue, and may contribute to new ideas or concepts in the important and evolving field of adipose biology.
Collapse
Affiliation(s)
- Emma Börgeson
- Department of Molecular and Clinical Medicine, Wallenberg Laboratory, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
- Region Vaestra Goetaland, Department of Clinical Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Jeremie Boucher
- The Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Metabolic Disease, Evotec International GmbH, Göttingen, Germany
| | - Carolina E. Hagberg
- Division of Cardiovascular Medicine, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- *Correspondence: Carolina E. Hagberg,
| |
Collapse
|
7
|
Zhu Q, An YA, Scherer PE. Mitochondrial regulation and white adipose tissue homeostasis. Trends Cell Biol 2021; 32:351-364. [PMID: 34810062 DOI: 10.1016/j.tcb.2021.10.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/26/2021] [Accepted: 10/28/2021] [Indexed: 12/12/2022]
Abstract
The important role of mitochondria in the regulation of white adipose tissue (WAT) remodeling and energy balance is increasingly appreciated. The remarkable heterogeneity of the adipose tissue stroma provides a cellular basis to enable adipose tissue plasticity in response to various metabolic stimuli. Regulating mitochondrial function at the cellular level in adipocytes, in adipose progenitor cells (APCs), and in adipose tissue macrophages (ATMs) has a profound impact on adipose homeostasis. Moreover, mitochondria facilitate the cell-to-cell communication within WAT, as well as the crosstalk with other organs, such as the liver, the heart, and the pancreas. A better understanding of mitochondrial regulation in the diverse adipose tissue cell types allows us to develop more specific and efficient approaches to improve adipose function and achieve improvements in overall metabolic health.
Collapse
Affiliation(s)
- Qingzhang Zhu
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yu A An
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
8
|
Bjørklund G, Tippairote T, Dadar M, Lizcano F, Aaseth J, Borisova O. The Roles of Dietary, Nutritional and Lifestyle Interventions in Adipose Tissue Adaptation and Obesity. Curr Med Chem 2021; 28:1683-1702. [PMID: 32368968 DOI: 10.2174/0929867327666200505090449] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 03/03/2020] [Accepted: 03/28/2020] [Indexed: 11/22/2022]
Abstract
The obesity and the associated non-communicable diseases (NCDs) are globally increasing in their prevalence. While the modern-day lifestyle required less ventilation of metabolic energy through muscular activities, this lifestyle transition also provided the unlimited accession to foods around the clock, which prolong the daily eating period of foods that contained high calorie and high glycemic load. These situations promote the high continuous flux of carbon substrate availability in mitochondria and induce the indecisive bioenergetic switches. The disrupted bioenergetic milieu increases the uncoupling respiration due to the excess flow of the substrate-derived reducing equivalents and reduces ubiquinones into the respiratory chain. The diversion of the uncoupling proton gradient through adipocyte thermogenesis will then alleviate the damaging effects of free radicals to mitochondria and other organelles. The adaptive induction of white adipose tissues (WAT) to beige adipose tissues (beAT) has shown beneficial effects on glucose oxidation, ROS protection and mitochondrial function preservation through the uncoupling protein 1 (UCP1)-independent thermogenesis of beAT. However, the maladaptive stage can eventually initiate with the persistent unhealthy lifestyles. Under this metabolic gridlock, the low oxygen and pro-inflammatory environments promote the adipose breakdown with sequential metabolic dysregulation, including insulin resistance, systemic inflammation and clinical NCDs progression. It is unlikely that a single intervention can reverse all these complex interactions. A comprehensive protocol that includes dietary, nutritional and all modifiable lifestyle interventions, can be the preferable choice to decelerate, stop, or reverse the NCDs pathophysiologic processes.
Collapse
Affiliation(s)
- Geir Bjørklund
- Council for Nutritional and Environmental Medicine (CONEM), Mo i Rana, Norway
| | - Torsak Tippairote
- Doctor of Philosophy Program in Nutrition, Faculty of Medicine Ramathibodi Hospital and Institute of Nutrition, Mahidol University, Bangkok, Thailand
| | - Maryam Dadar
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | | | - Jan Aaseth
- Research Department, Innlandet Hospital Trust, Brumunddal, Norway
| | - Olga Borisova
- Odesa I. I. Mechnikov National University, Odessa, Ukraine
| |
Collapse
|
9
|
Adipocyte-Mineralocorticoid Receptor Alters Mitochondrial Quality Control Leading to Mitochondrial Dysfunction and Senescence of Visceral Adipose Tissue. Int J Mol Sci 2021; 22:ijms22062881. [PMID: 33809055 PMCID: PMC8001019 DOI: 10.3390/ijms22062881] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 03/03/2021] [Accepted: 03/08/2021] [Indexed: 12/22/2022] Open
Abstract
Mineralocorticoid receptor (MR) expression is increased in the adipose tissue (AT) of obese patients and animals. We previously demonstrated that adipocyte-MR overexpression in mice (Adipo-MROE mice) is associated with metabolic alterations. Moreover, we showed that MR regulates mitochondrial dysfunction and cellular senescence in the visceral AT of obese db/db mice. Our hypothesis is that adipocyte-MR overactivation triggers mitochondrial dysfunction and cellular senescence, through increased mitochondrial oxidative stress (OS). Using the Adipo-MROE mice with conditional adipocyte-MR expression, we evaluated the specific effects of adipocyte-MR on global and mitochondrial OS, as well as on OS-induced damage. Mitochondrial function was assessed by high throughput respirometry. Molecular mechanisms were probed in AT focusing on mitochondrial quality control and senescence markers. Adipo-MROE mice exhibited increased mitochondrial OS and altered mitochondrial respiration, associated with reduced biogenesis and increased fission. This was associated with OS-induced DNA-damage and AT premature senescence. In conclusion, targeted adipocyte-MR overexpression leads to an imbalance in mitochondrial dynamics and regeneration, to mitochondrial dysfunction and to ageing in visceral AT. These data bring new insights into the MR-dependent AT dysfunction in obesity.
Collapse
|
10
|
Romeiro NC, Ferreira CM, Oliveira MF. Assessment of mitochondrial physiology of murine white adipose tissue by mechanical permeabilization and lipid depletion. Anal Biochem 2020; 611:113935. [PMID: 32898480 DOI: 10.1016/j.ab.2020.113935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 08/25/2020] [Accepted: 08/31/2020] [Indexed: 11/20/2022]
Abstract
White adipose tissue (WAT) represents a major site of triacylglycerol energy storage and is directly associated with metabolic disorders. Mitochondria regulate cellular energy expenditure and are active in WAT. Although isolated mitochondria have been classically used to assess their functions, several artifacts can be introduced by this approach. Furthermore, important limitations exist in the available methods to determine mitochondrial physiology in permeabilized WAT. Here, we established and validated a method for functional evaluation of mice mesenteric WAT (mWAT) mitochondria by using MEchanical Permeabilization and LIpid DEpletion (MEPLIDE) coupled to high-resolution respirometry. We observed that mild stirring of mWAT for 20 min at room temperature with 4% fatty acid-free albumin (FAF-BSA) followed by 50 min without FAF-BSA selectively permeabilized white adipocytes plasma membrane. In these conditions, mWAT mitochondria were intact, exhibiting succinate-induced respiratory rates that were sensitive to classical oxidative phosphorylation modulators. Finally, the respiratory capacity of mWAT in female mice was significantly higher than in males, an observation that agrees with reported data. Therefore, the functional assessment of mWAT mitochondria through MEPLIDE coupled to high resolution respirometry proposed here will contribute to a better understanding of WAT biology in several pathophysiological contexts.
Collapse
Affiliation(s)
- Natália C Romeiro
- Laboratório de Bioquímica de Resposta Ao Estresse, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal Do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, Brazil
| | - Caroline M Ferreira
- Laboratório de Bioquímica de Resposta Ao Estresse, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal Do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, Brazil
| | - Marcus F Oliveira
- Laboratório de Bioquímica de Resposta Ao Estresse, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal Do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, Brazil.
| |
Collapse
|
11
|
Yamada T, Kamiya M, Higuchi M. Breed differences in macrophage infiltration and senescence state in adipose tissues of Wagyu and Holsteins. Anim Sci J 2020; 91:e13443. [PMID: 32779259 DOI: 10.1111/asj.13443] [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: 04/03/2020] [Revised: 06/07/2020] [Accepted: 07/15/2020] [Indexed: 11/30/2022]
Abstract
Obesity stimulates the macrophage infiltration and senescence state in adipose tissues of humans and rodents. The adipogenesis capacity of Japanese Black cattle (Wagyu) is higher than that of Holsteins. We hypothesized that breed differences between Wagyu and Holsteins may affect the level of macrophage infiltration and senescence state in adipose tissues. The macrophage infiltration, senescence marker gene expression and activity of senescence-associated β-galactosidase (SA-βgal) in visceral and intramuscular adipose tissue of Wagyu were higher than those of Holsteins. In contrast, there were no differences in macrophage infiltration, senescence marker gene expression and activity of SA-βgal in subcutaneous adipose tissue between the breeds. Expression of p53 gene, the master regulator of macrophage infiltration and senescence state, in visceral and intramuscular adipose tissue of Wagyu was higher than that of Holsteins. In contrast, there was no difference in the expression of p53 gene in subcutaneous adipose tissue between the breeds. These results suggest that breed differences in macrophage infiltration and senescence state in adipose tissues of Wagyu and Holsteins are affected by p53 expression.
Collapse
Affiliation(s)
- Tomoya Yamada
- Division of Livestock Feeding and Management, National Agriculture and Food Research Organization, Nasushiobara-shi, Japan
| | - Mituru Kamiya
- Division of Livestock Feeding and Management, National Agriculture and Food Research Organization, Nasushiobara-shi, Japan
| | - Mikito Higuchi
- Division of Livestock Feeding and Management, National Agriculture and Food Research Organization, Nasushiobara-shi, Japan
| |
Collapse
|
12
|
Du Y, Chen Y, Fu X, Gu J, Sun Y, Zhang Z, Xu J, Qin L. Effects of piperine on lipid metabolism in high-fat diet induced obese mice. J Funct Foods 2020. [DOI: 10.1016/j.jff.2020.104011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
13
|
Dawid C, Weber D, Musiol E, Janas V, Baur S, Lang R, Fromme T. Comparative assessment of purified saponins as permeabilization agents during respirometry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148251. [PMID: 32598881 DOI: 10.1016/j.bbabio.2020.148251] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/26/2020] [Accepted: 06/12/2020] [Indexed: 01/15/2023]
Abstract
Saponins are a diverse group of secondary plant metabolites, some of which display hemolytic toxicity due to plasma membrane permeabilization. This feature is employed in biological applications for transferring hydrophilic molecules through cell membranes. Widely used commercial saponins include digitonin and saponins from soap tree bark, both of which constitute complex mixtures of little definition. We assessed the permeabilization power of pure saponins towards cellular membranes in an effort to detect novel properties and to improve existing applications. In a respirometric assay, we characterized half-maximal permeabilization of the plasma membrane for different metabolites, of the mitochondrial outer membrane for cytochrome C and the full solubilization of mitochondrial inner membrane protein complexes. Beyond the complete list as repository for the field, we highlight several findings with direct applicability. First, we identified and validated α-chaconine as alternative permeabilization agent in respirometric assays of cultured cells and isolated synaptosomes, superior to digitonin in its tolerability for mitochondria. Second, we identified glycyrrhizic acid to form exceptionally small pores impermeable for adenosine diphosphate. Third, in a concentration dependent manner, tomatine proved to be able to selectively permeabilize the mitochondrial outer, but not inner membrane, allowing for novel states in which to determine cytochrome C oxidase activity. In summary, we provide a list of the permeabilization properties of 18 pure saponins. The identification of two saponins, namely tomatine and chaconine, with direct usability in improved or novel cell biological applications within this small subgroup demonstrates the tremendous potential for further functional screening of pure saponins.
Collapse
Affiliation(s)
- Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Freising, Germany
| | - Daniela Weber
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Eva Musiol
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Vanessa Janas
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Sebastian Baur
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Freising, Germany
| | - Roman Lang
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Freising, Germany
| | - Tobias Fromme
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany; EKFZ - Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany.
| |
Collapse
|
14
|
Jin H, Lee K, Chei S, Oh HJ, Lee KP, Lee BY. Ecklonia stolonifera Extract Suppresses Lipid Accumulation by Promoting Lipolysis and Adipose Browning in High-Fat Diet-Induced Obese Male Mice. Cells 2020; 9:E871. [PMID: 32252474 PMCID: PMC7226821 DOI: 10.3390/cells9040871] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/21/2020] [Accepted: 02/21/2020] [Indexed: 12/18/2022] Open
Abstract
Obesity develops due to an energy imbalance and manifests as the storage of excess triglyceride (TG) in white adipose tissue (WAT). Recent studies have determined that edible natural materials can reduce lipid accumulation and promote browning in WAT. We aimed to determine whether Ecklonia stolonifera extract (ESE) would increase the energy expenditure in high-fat diet (HFD)-induced obese mice and 3T3-L1 cells by upregulating lipolysis and browning. ESE is an edible brown marine alga that belongs to the family Laminariaceae and contains dieckol, a phlorotannin. We report that ESE inhibits body mass gain by regulating the expression of proteins involved in adipogenesis and lipogenesis. In addition, ESE activates protein kinase A (PKA) and increases the expression of lipolytic enzymes including adipose triglyceride lipase (ATGL), phosphorylated hormone-sensitive lipase (p-HSL), and monoacylglycerol lipase (MGL) and also thermogenic genes, such as carnitine palmitoyltransferase 1 (CPT1), PR domain-containing 16 (PRDM16), and uncoupling protein 1 (UCP1). These findings indicate that ESE may represent a promising natural means of preventing obesity and obesity-related metabolic diseases.
Collapse
Affiliation(s)
- Heegu Jin
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Gyeonggi 13488, Korea; (H.J.); (K.L.); (S.C.); (H.-J.O.)
| | - Kippeum Lee
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Gyeonggi 13488, Korea; (H.J.); (K.L.); (S.C.); (H.-J.O.)
| | - Sungwoo Chei
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Gyeonggi 13488, Korea; (H.J.); (K.L.); (S.C.); (H.-J.O.)
| | - Hyun-Ji Oh
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Gyeonggi 13488, Korea; (H.J.); (K.L.); (S.C.); (H.-J.O.)
| | | | - Boo-Yong Lee
- Department of Food Science and Biotechnology, College of Life Science, CHA University, Seongnam, Gyeonggi 13488, Korea; (H.J.); (K.L.); (S.C.); (H.-J.O.)
| |
Collapse
|
15
|
Dos Santos MR, da Fonseca GWP, Sherveninas LP, de Souza FR, Battaglia Filho AC, Novaes CE, Pereira RMR, Negrão CE, Barretto ACP, Alves MJDNN. Android to gynoid fat ratio and its association with functional capacity in male patients with heart failure. ESC Heart Fail 2020; 7:1101-1108. [PMID: 32220062 PMCID: PMC7261564 DOI: 10.1002/ehf2.12657] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/27/2020] [Accepted: 02/06/2020] [Indexed: 12/16/2022] Open
Abstract
AIMS We studied the association between android (A) to gynoid (G) fat ratio and functional capacity (peak VO2 ) in male patients with heart failure with reduced ejection fraction (HFrEF). METHODS AND RESULTS We enrolled 118 male patients with HFrEF with left ventricular ejection fraction (LVEF) <40%. Body composition (by using dual x-ray absorptiometry) and peak VO2 (by cardiopulmonary exercise testing) were measured. Sarcopenic obesity was defined according to the Foundation for the National Institutes of Health criteria (FNIH). Blood sample for metabolic and hormonal parameters were measured. Fifteen patients (12.7%) showed sarcopenic obesity (body mass index > 25 kg/m2 with FNIH index < 0.789). The median A/G ratio was 0.55. A/G ratio > 0.55 was detected in 60 patients. Relative peak VO2 was lower in patients with A/G ratio > 0.55 than in patients with A/G ratio <0.55 (18.7 ± 5.3 vs. 22.5 ± 6.1 mL/kg/min, P < 0.001). Logistic regression analysis showed A/G ratio >0.55 to be independently associated with reduced peak VO2 adjusted for age, body mass index, LVEF, presence of sarcopenia, anabolic hormones, and haemoglobin (odds ratio 3.895, 95% confidence interval 1.030-14.730, P = 0.045). CONCLUSIONS Body fat distribution, particularly android and gynoid fat composition, together with other cofactors, might have an important adverse role on functional capacity in male patients with HFrEF. Future studies are needed to address possible mechanisms involved in this relationship.
Collapse
Affiliation(s)
- Marcelo Rodrigues Dos Santos
- Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | | | - Letícia Pironato Sherveninas
- Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Francis Ribeiro de Souza
- Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Antônio Carlos Battaglia Filho
- Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Caio Eduardo Novaes
- Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Rosa Maria Rodrigues Pereira
- Laboratório de Reumatologia e Metabolismo Ósseo da Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Carlos Eduardo Negrão
- Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.,School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | - Antônio Carlos Pereira Barretto
- Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | | |
Collapse
|
16
|
Schöttl T, Pachl F, Giesbertz P, Daniel H, Kuster B, Fromme T, Klingenspor M. Proteomic and Metabolite Profiling Reveals Profound Structural and Metabolic Reorganization of Adipocyte Mitochondria in Obesity. Obesity (Silver Spring) 2020; 28:590-600. [PMID: 32034895 DOI: 10.1002/oby.22737] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 11/26/2019] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Previous studies have revealed decreased mitochondrial respiration in adipocytes of obese mice. This study aimed to identify the molecular underpinnings of altered mitochondrial metabolism in adipocytes. METHODS Untargeted proteomics of mitochondria isolated from adipocytes and metabolite profiling of adipose tissues were conducted in diet-induced obese (DIO) and lean mice. Subcutaneous and intra-abdominal adipose tissues were studied to depict depot-specific alterations. RESULTS In subcutaneous adipocytes of DIO mice, changes in proteins related to mitochondrial structure and function were observed. Mitochondrial proteins of the inner and outer membrane were strongly reduced, whereas proteins of key matrix metabolic pathways were increased in the obese versus lean state, as further substantiated by metabolite profiling. A pronounced decrease in the oxidative phosphorylation (OXPHOS) enzymatic equipment and cristae density of the inner membrane was identified. In intra-abdominal adipocytes, similar systematic downregulation of the OXPHOS machinery in obesity occurred, but there was no regulation of outer membrane or matrix proteins. CONCLUSIONS Protein components of the OXPHOS machinery are systematically downregulated in adipose tissues of DIO mice compared with lean mice. Loss of the mitochondrial OXPHOS capacity in adipocytes may aggravate the development of metabolic disease.
Collapse
Affiliation(s)
- Theresa Schöttl
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
- EKFZ-Else Kröner Fresenius Zentrum for Nutritional Medicine, Technical Universtiy of Munich, Freising, Germany
- ZIEL-Institute for Food & Health, Technical University of Munich, Freising, Germany
| | - Fiona Pachl
- ZIEL-Institute for Food & Health, Technical University of Munich, Freising, Germany
- Chair of Proteomics and Bioanalytics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Pieter Giesbertz
- Chair of Nutritional Physiology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Hannelore Daniel
- Chair of Nutritional Physiology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Bernhard Kuster
- ZIEL-Institute for Food & Health, Technical University of Munich, Freising, Germany
- Chair of Proteomics and Bioanalytics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Tobias Fromme
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
- EKFZ-Else Kröner Fresenius Zentrum for Nutritional Medicine, Technical Universtiy of Munich, Freising, Germany
- ZIEL-Institute for Food & Health, Technical University of Munich, Freising, Germany
| | - Martin Klingenspor
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
- EKFZ-Else Kröner Fresenius Zentrum for Nutritional Medicine, Technical Universtiy of Munich, Freising, Germany
- ZIEL-Institute for Food & Health, Technical University of Munich, Freising, Germany
| |
Collapse
|
17
|
Heinonen S, Jokinen R, Rissanen A, Pietiläinen KH. White adipose tissue mitochondrial metabolism in health and in obesity. Obes Rev 2020; 21:e12958. [PMID: 31777187 DOI: 10.1111/obr.12958] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 08/27/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022]
Abstract
White adipose tissue is one of the largest organs of the body. It plays a key role in whole-body energy status and metabolism; it not only stores excess energy but also secretes various hormones and metabolites to regulate body energy balance. Healthy adipose tissue capable of expanding is needed for metabolic well-being and to prevent accumulation of triglycerides to other organs. Mitochondria govern several important functions in the adipose tissue. We review the derangements of mitochondrial function in white adipose tissue in the obese state. Downregulation of mitochondrial function or biogenesis in the white adipose tissue is a central driver for obesity-associated metabolic diseases. Mitochondrial functions compromised in obesity include oxidative functions and renewal and enlargement of the adipose tissue through recruitment and differentiation of adipocyte progenitor cells. These changes adversely affect whole-body metabolic health. Dysfunction of the white adipose tissue mitochondria in obesity has long-term consequences for the metabolism of adipose tissue and the whole body. Understanding the pathways behind mitochondrial dysfunction may help reveal targets for pharmacological or nutritional interventions that enhance mitochondrial biogenesis or function in adipose tissue.
Collapse
Affiliation(s)
- Sini Heinonen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Riikka Jokinen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Aila Rissanen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Department of Psychiatry, Helsinki University Hospital, Helsinki, Finland
| | - Kirsi H Pietiläinen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Endocrinology, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| |
Collapse
|
18
|
Dietary Silk Peptide Prevents High-Fat Diet-Induced Obesity and Promotes Adipose Browning by Activating AMP-Activated Protein Kinase in Mice. Nutrients 2020; 12:nu12010201. [PMID: 31941008 PMCID: PMC7019986 DOI: 10.3390/nu12010201] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/04/2020] [Accepted: 01/09/2020] [Indexed: 02/08/2023] Open
Abstract
Obesity is associated with metabolic syndrome and other chronic diseases, and is caused when the energy intake is greater than the energy expenditure. We aimed to determine the mechanism whereby acid-hydrolyzed silk peptide (SP) prevents high-fat diet-induced obesity, and whether it induces browning and fatty acid oxidation (FAO) in white adipose tissue (WAT), using in vivo and ex vivo approaches. We determined the effects of dietary SP in high-fat diet-fed obese mice. The expression of adipose tissue-specific genes was quantified by western blotting, qRT-PCR, and immunofluorescence analysis. We also investigated whether SP directly induces browning in primarily subcutaneous WAT-derived adipocytes. Our findings demonstrate that SP has a browning effect in WAT by upregulating AMP-activated Protein Kinase (AMPK) phosphorylation and uncoupling protein 1 (UCP1) expression. SP also suppresses adipogenesis and promotes FAO, implying that it may have potential as an anti-obesity drug.
Collapse
|
19
|
Kodde A, Engels E, Oosting A, van Limpt K, van der Beek EM, Keijer J. Maturation of White Adipose Tissue Function in C57BL/6j Mice From Weaning to Young Adulthood. Front Physiol 2019; 10:836. [PMID: 31354508 PMCID: PMC6629938 DOI: 10.3389/fphys.2019.00836] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/17/2019] [Indexed: 01/13/2023] Open
Abstract
White adipose tissue (WAT) distribution and WAT mitochondrial function contribute to total body metabolic health throughout life. Nutritional interventions starting in the postweaning period may impact later life WAT health and function. We therefore assessed changes in mitochondrial density and function markers in WAT depots of young mice. Inguinal (ING), epididymal (EPI) and retroperitoneal (RP) WAT of 21, 42 and 98 days old C57BL/6j mice was collected. Mitochondrial density [citrate synthase (CS), mtDNA] and function [subunits of oxidative phosphorylation complexes (OXPHOS)] markers were analyzed, together with gene expression of browning markers (Ucp1, Cidea). mRNA of ING WAT of 21 and 98 old mice was sequenced to further investigate functional changes of the mitochondria and alterations in cell populations. CS levels decreased significantly over time in all depots. ING showed most pronounced changes, including significantly decreased levels of OXPHOS complex I, II, and III subunits and gene expression of Ucp1 (PN21-42 and PN42-98) and Cidea (PN42-98). White adipocyte markers were higher at PN98 in ING WAT. Analyses of RNA sequence data showed that the mitochondrial functional profile changed over time from “growth-supporting” mitochondria focused on ATP production (and dissipation), to more steady-state mitochondria with more diverse functions and higher biosynthesis. Mitochondrial density and energy metabolism markers declined in all three depots over time after weaning. This was most pronounced in ING WAT and associated with reduced browning markers, increased whitening and an altered metabolism. In particular the PN21-42 period may provide a time window to study mitochondrial adaptation and effects of nutritional exposures relevant for later life metabolic health.
Collapse
Affiliation(s)
| | | | | | | | - Eline M van der Beek
- Danone Nutricia Research, Utrecht, Netherlands.,Department of Pediatrics, University Medical Center Groningen - University of Groningen, Groningen, Netherlands
| | - Jaap Keijer
- Human and Animal Physiology, Wageningen University, Wageningen, Netherlands
| |
Collapse
|
20
|
Keuper M. On the role of macrophages in the control of adipocyte energy metabolism. Endocr Connect 2019; 8:R105-R121. [PMID: 31085768 PMCID: PMC6590200 DOI: 10.1530/ec-19-0016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 05/14/2019] [Indexed: 12/11/2022]
Abstract
The crosstalk between macrophages (MΦ) and adipocytes within white adipose tissue (WAT) influences obesity-associated insulin resistance and other associated metabolic disorders, such as atherosclerosis, hypertension and type 2 diabetes. MΦ infiltration is increased in WAT during obesity, which is linked to decreased mitochondrial content and activity. The mechanistic interplay between MΦ and mitochondrial function of adipocytes is under intense investigation, as MΦ and inflammatory pathways exhibit a pivotal role in the reprogramming of WAT metabolism in physiological responses during cold, fasting and exercise. Thus, the underlying immunometabolic pathways may offer therapeutic targets to correct obesity and metabolic disease. Here, I review the current knowledge on the quantity and the quality of human adipose tissue macrophages (ATMΦ) and their impact on the bioenergetics of human adipocytes. The effects of ATMΦ and their secreted factors on mitochondrial function of white adipocytes are discussed, including recent research on MΦ as part of an immune signaling cascade involved in the 'browning' of WAT, which is defined as the conversion from white, energy-storing adipocytes into brown, energy-dissipating adipocytes.
Collapse
Affiliation(s)
- Michaela Keuper
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| |
Collapse
|
21
|
Wessels B, Honecker J, Schöttl T, Stecher L, Klingenspor M, Hauner H, Skurk T. Adipose Mitochondrial Respiratory Capacity in Obesity is Impaired Independently of Glycemic Status of Tissue Donors. Obesity (Silver Spring) 2019; 27:756-766. [PMID: 30912621 DOI: 10.1002/oby.22435] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 01/12/2019] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The study aimed to investigate how obesity and glycemic state affect mitochondrial respiration and ATP-generating pathways in mature human adipocytes. METHODS Subcutaneous (sc) and visceral (vc) adipocytes were isolated from patients undergoing abdominal surgery. Respiratory chain function was analyzed by high-resolution respirometry. Adipocyte ATP levels and lactate release were measured separately in the presence of either glycolysis (2-deoxy-D-glucose) or ATP synthase (oligomycin) inhibitors. RESULTS A significant negative correlation between oxidative phosphorylation capacity and the BMI of tissue donors found in sc adipocytes (P < 0.05). Furthermore, respirometry revealed an inverse relationship between BMI and the electron transfer system capacity of sc (P < 0.05) but not vc adipocytes. In both depots, the respiratory capacity was not affected by the glycemic state. A positive correlation between BMI and adipocyte lactate release was measured independently of the tissue origin (sc: P = 0.01; vc: P < 0.05). Direct ATP measurements indicated that energy demands of adipocytes were predominantly fulfilled by glycolytic activity. CONCLUSIONS The study's data suggest that obesity is the primary driver of impaired adipocyte mitochondrial respiration because the glycemic state did not further deteriorate this situation. The adipocytes' energy needs are covered primarily by the glycolytic pathway.
Collapse
Affiliation(s)
- Britta Wessels
- Department of Nutritional Medicine, Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising-Weihenstephan, Germany
| | - Julius Honecker
- Department of Nutritional Medicine, Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising-Weihenstephan, Germany
| | - Theresa Schöttl
- Department of Molecular Nutritional Medicine, Technical University of Munich, Freising-Weihenstephan, Germany
| | - Lynne Stecher
- Institute for Nutritional Medicine, Rechts der Isar Hospital, Technical University of Munich, Munich, Germany
| | - Martin Klingenspor
- Department of Molecular Nutritional Medicine, Technical University of Munich, Freising-Weihenstephan, Germany
| | - Hans Hauner
- Department of Nutritional Medicine, Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising-Weihenstephan, Germany
- Institute for Nutritional Medicine, Rechts der Isar Hospital, Technical University of Munich, Munich, Germany
| | - Thomas Skurk
- Department of Nutritional Medicine, Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising-Weihenstephan, Germany
- Institute for Food and Health, Core Facility Human Studies, Technical University of Munich, Freising-Weihenstephan, Germany
| |
Collapse
|
22
|
Kappler L, Kollipara L, Lehmann R, Sickmann A. Investigating the Role of Mitochondria in Type 2 Diabetes - Lessons from Lipidomics and Proteomics Studies of Skeletal Muscle and Liver. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1158:143-182. [PMID: 31452140 DOI: 10.1007/978-981-13-8367-0_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mitochondrial dysfunction is discussed as a key player in the pathogenesis of type 2 diabetes mellitus (T2Dm), a highly prevalent disease rapidly developing as one of the greatest global health challenges of this century. Data however about the involvement of mitochondria, central hubs in bioenergetic processes, in the disease development are still controversial. Lipid and protein homeostasis are under intense discussion to be crucial for proper mitochondrial function. Consequently proteomics and lipidomics analyses might help to understand how molecular changes in mitochondria translate to alterations in energy transduction as observed in the healthy and metabolic diseases such as T2Dm and other related disorders. Mitochondrial lipids integrated in a tool covering proteomic and functional analyses were up to now rarely investigated, although mitochondrial lipids might provide a possible lynchpin in the understanding of type 2 diabetes development and thereby prevention. In this chapter state-of-the-art analytical strategies, pre-analytical aspects, potential pitfalls as well as current proteomics and lipidomics-based knowledge about the pathophysiological role of mitochondria in the pathogenesis of type 2 diabetes will be discussed.
Collapse
Affiliation(s)
- Lisa Kappler
- Institute for Clinical Chemistry and Pathobiochemistry, Department for Diagnostic Laboratory Medicine, University Hospital Tuebingen, Tuebingen, Germany
| | - Laxmikanth Kollipara
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Rainer Lehmann
- Institute for Clinical Chemistry and Pathobiochemistry, Department for Diagnostic Laboratory Medicine, University Hospital Tuebingen, Tuebingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Centre Munich at the University of Tuebingen, Tuebingen, Germany.,German Center for Diabetes Research (DZD e.V.), Tuebingen, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany. .,Medical Proteome Centre, Ruhr Universität Bochum, Bochum, Germany. .,Department of Chemistry, College of Physical Sciences, University of Aberdeen, Aberdeen, UK.
| |
Collapse
|
23
|
Ost M, Doerrier C, Gama-Perez P, Moreno-Gomez S. Analysis of mitochondrial respiratory function in tissue biopsies and blood cells. Curr Opin Clin Nutr Metab Care 2018; 21:336-342. [PMID: 29939971 DOI: 10.1097/mco.0000000000000486] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW The review provides an overview on latest methodological strategies to assess mitochondrial respiratory function in tissue biopsies or blood cells. In addition, it summarizes the recent literature related to this topic. RECENT FINDINGS Today, the study of mitochondrial function in key metabolic active tissues has been become more relevant, with increasing focus in clinical applications. In addition, assessment of mitochondrial function in blood cells by respirometry might be a sensitive biomarker of disease progression. High-Resolution Respirometry provides a modern tool to study mitochondrial respiratory physiology which allows direct measurement of cellular metabolic function during health and disease. Moreover, standard operating procedures are required regarding instrumental settings, sample collection and preparation, protocol design and respirometric data analysis of mitochondrial respiratory function in tissue biopsies (such as skeletal muscle, liver and adipose tissue), as well as isolated blood cells. SUMMARY Mitochondrial function is a key factor in many metabolic diseases. Although various analytical approaches are available, certain well-established protocols for isolated mitochondria are limited for the analysis of mitochondrial function in tissue biopsies or blood cells. Thus, cautious considerations in selecting appropriate protocols and analytical endpoints are crucial for the interpretation of the gained data and to draw robust conclusions.
Collapse
Affiliation(s)
- Mario Ost
- Department of Physiology of Energy Metabolism, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
| | | | - Pau Gama-Perez
- Department of Physiological Sciences, University of Barcelona, Barcelona, Spain
| | - Sonia Moreno-Gomez
- Department of Physiological Sciences, University of Barcelona, Barcelona, Spain
| |
Collapse
|
24
|
Yamada T, Kamiya M, Higuchi M, Nakanishi N. Fat depot-specific differences of macrophage infiltration and cellular senescence in obese bovine adipose tissues. J Vet Med Sci 2018; 80:1495-1503. [PMID: 30111687 PMCID: PMC6207504 DOI: 10.1292/jvms.18-0324] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Obesity is associated with the chronic inflammation and senescence of adipose tissues.
Macrophage is a key mediator of chronic inflammation that infiltrates obese adipose tissue
and stimulates metabolic disorders. However, the fat depot-specific differences of
macrophage infiltration and senescence, especially the influence on intramuscular adipose
tissue, have remained unclear. We investigated the fat depot-specific differences of
macrophage infiltration and senescence in obese bovine adipose tissue from three different
anatomical sites (subcutaneous, intramuscular and visceral). Macrophage infiltrations and
crown-like structures were observed in visceral adipose tissue, although there were few
macrophages in subcutaneous and intramuscular adipose tissues. The positive reaction of
senescence marker SA-βgal activity was observed in visceral adipose tissue. In contrast,
the activity of SA-βgal in subcutaneous and intramuscular adipose tissues were low. The
expression of p53 gene, the master regulator of cellular senescence, in visceral adipose
tissue was higher than that of subcutaneous and intramuscular adipose tissue. At the
cellular level, p53 gene expression was negatively correlated with the size of
subcutaneous adipocytes. In contrast, p53 gene expressions were positively correlated with
the size of intramuscular and visceral adipocytes. These results indicate that anatomical
sites of obese adipose tissue affect macrophage infiltration and the senescent state in a
fat depot-specific manner.
Collapse
Affiliation(s)
- Tomoya Yamada
- Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Nasushiobara-shi, Tochigi 329-2793, Japan
| | - Mituru Kamiya
- Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Nasushiobara-shi, Tochigi 329-2793, Japan
| | - Mikito Higuchi
- Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Nasushiobara-shi, Tochigi 329-2793, Japan
| | - Naoto Nakanishi
- Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Nasushiobara-shi, Tochigi 329-2793, Japan
| |
Collapse
|
25
|
Birnbacher L, Maurer S, Scheidt K, Herzen J, Pfeiffer F, Fromme T. Electron Density of Adipose Tissues Determined by Phase-Contrast Computed Tomography Provides a Measure for Mitochondrial Density and Fat Content. Front Physiol 2018; 9:707. [PMID: 29962958 PMCID: PMC6013718 DOI: 10.3389/fphys.2018.00707] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/22/2018] [Indexed: 11/13/2022] Open
Abstract
Phase-contrast computed tomography (PCCT) is an X-ray-based imaging method measuring differences in the refractive index during tissue passage. While conventional X-ray techniques rely on the absorption of radiation due to differing tissue-specific attenuation coefficients, PCCT enables the determination of the electron density (ED). By the analysis of respective phantoms and ex vivo specimens, we identified the components responsible for different electron densities in murine adipose tissue depots to be cellular fat and mitochondrial content, two parameters typically different between white adipose tissue (WAT) and brown adipose tissue (BAT). Brown adipocytes provide mammals with a means of non-shivering thermogenesis to defend normothermia in a cold environment. Brown adipocytes are found in dedicated BAT depots and interspersed within white fat depots, a cell type referred to as brite (brown in white) adipocyte. Localization and quantification of brown and brite adipocytes in situ allows an estimate of depot thermogenic capacity and potential contribution to maximal metabolic rate in the cold. We utilized PCCT to infer the composition of white, brite, and brown adipose tissue from ED of individual depots. As proof of principle, we imaged mice 10, 20, and 30 days of age. During this period, several WAT depots are known to undergo transient browning. Based on ED, classical WAT and BAT could be clearly distinguished. Retroperitoneal and inguinal WAT depots increased transiently in ED during the known remodeling from white to brite/brown and back to white. We systematically analyzed 18 anatomically defined adipose tissue locations and identified changes in fat content and mitochondrial density that imply an orchestrated pattern of simultaneous browning and whitening on the organismic level. Taken together, PCCT provides a three-dimensional imaging technique to visualize ED of tissues in situ. Within the adipose organ, ED provides a measure of mitochondrial density and fat content. Depending on experimental setting, these constitute surrogate markers of cellular distribution of white, brite, and brown adipocytes and thereby an estimate of thermogenic capacity.
Collapse
Affiliation(s)
- Lorenz Birnbacher
- Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
| | - Stefanie Maurer
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Munich, Germany.,Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany
| | - Katharina Scheidt
- Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
| | - Julia Herzen
- Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
| | - Franz Pfeiffer
- Biomedical Physics, Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany.,Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Institute for Advanced Study, Technical University of Munich, Munich, Germany
| | - Tobias Fromme
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Munich, Germany.,Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany
| |
Collapse
|
26
|
Boutens L, Hooiveld GJ, Dhingra S, Cramer RA, Netea MG, Stienstra R. Unique metabolic activation of adipose tissue macrophages in obesity promotes inflammatory responses. Diabetologia 2018; 61:942-953. [PMID: 29333574 PMCID: PMC6448980 DOI: 10.1007/s00125-017-4526-6] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 11/13/2017] [Indexed: 12/23/2022]
Abstract
AIMS/HYPOTHESIS Recent studies have identified intracellular metabolism as a fundamental determinant of macrophage function. In obesity, proinflammatory macrophages accumulate in adipose tissue and trigger chronic low-grade inflammation, that promotes the development of systemic insulin resistance, yet changes in their intracellular energy metabolism are currently unknown. We therefore set out to study metabolic signatures of adipose tissue macrophages (ATMs) in lean and obese conditions. METHODS F4/80-positive ATMs were isolated from obese vs lean mice. High-fat feeding of wild-type mice and myeloid-specific Hif1α-/- mice was used to examine the role of hypoxia-inducible factor-1α (HIF-1α) in ATMs part of obese adipose tissue. In vitro, bone marrow-derived macrophages were co-cultured with adipose tissue explants to examine adipose tissue-induced changes in macrophage phenotypes. Transcriptome analysis, real-time flux measurements, ELISA and several other approaches were used to determine the metabolic signatures and inflammatory status of macrophages. In addition, various metabolic routes were inhibited to determine their relevance for cytokine production. RESULTS Transcriptome analysis and extracellular flux measurements of mouse ATMs revealed unique metabolic rewiring in obesity characterised by both increased glycolysis and oxidative phosphorylation. Similar metabolic activation of CD14+ cells in obese individuals was associated with diabetes outcome. These changes were not observed in peritoneal macrophages from obese vs lean mice and did not resemble metabolic rewiring in M1-primed macrophages. Instead, metabolic activation of macrophages was dose-dependently induced by a set of adipose tissue-derived factors that could not be reduced to leptin or lactate. Using metabolic inhibitors, we identified various metabolic routes, including fatty acid oxidation, glycolysis and glutaminolysis, that contributed to cytokine release by ATMs in lean adipose tissue. Glycolysis appeared to be the main contributor to the proinflammatory trait of macrophages in obese adipose tissue. HIF-1α, a key regulator of glycolysis, nonetheless appeared to play no critical role in proinflammatory activation of ATMs during early stages of obesity. CONCLUSIONS/INTERPRETATION Our results reveal unique metabolic activation of ATMs in obesity that promotes inflammatory cytokine release. Further understanding of metabolic programming in ATMs will most likely lead to novel therapeutic targets to curtail inflammatory responses in obesity. DATA AVAILABILITY Microarray data of ATMs isolated from obese or lean mice have been submitted to the Gene Expression Omnibus (accession no. GSE84000).
Collapse
Affiliation(s)
- Lily Boutens
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands
- Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, the Netherlands
| | - Guido J Hooiveld
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands
| | - Sourabh Dhingra
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Robert A Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Mihai G Netea
- Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, the Netherlands
| | - Rinke Stienstra
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands.
- Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, the Netherlands.
| |
Collapse
|
27
|
Schoettl T, Fischer IP, Ussar S. Heterogeneity of adipose tissue in development and metabolic function. ACTA ACUST UNITED AC 2018. [PMID: 29514879 DOI: 10.1242/jeb.162958] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Adipose tissue is a central metabolic organ. Unlike other organs, adipose tissue is compartmentalized into individual depots and distributed throughout the body. These different adipose depots show major functional differences and risk associations for developing metabolic syndrome. Recent advances in lineage tracing demonstrate that individual adipose depots are composed of adipocytes that are derived from distinct precursor populations, giving rise to different populations of energy-storing white adipocytes. Moreover, distinct lineages of energy-dissipating brown and beige adipocytes exist in discrete depots or within white adipose tissue depots. In this Review, we discuss developmental and functional heterogeneity, as well as sexual dimorphism, between and within individual adipose tissue depots. We highlight current data relating to the differences between subcutaneous and visceral white adipose tissue in the development of metabolic dysfunction, with special emphasis on adipose tissue expansion and remodeling of the extracellular matrix. Moreover, we provide a detailed overview of adipose tissue development as well as the consensus and controversies relating to adult adipocyte precursor populations.
Collapse
Affiliation(s)
- Theresa Schoettl
- JRG Adipocytes and Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Center Munich, 85748 Garching, Germany.,German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Ingrid P Fischer
- JRG Adipocytes and Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Center Munich, 85748 Garching, Germany.,German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.,Division of Metabolic Diseases, Department of Medicine, Technische Universität München, 80333 Munich, Germany
| | - Siegfried Ussar
- JRG Adipocytes and Metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Center Munich, 85748 Garching, Germany .,German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| |
Collapse
|
28
|
Sepa-Kishi DM, Ceddia RB. White and beige adipocytes: are they metabolically distinct? Horm Mol Biol Clin Investig 2018; 33:/j/hmbci.ahead-of-print/hmbci-2018-0003/hmbci-2018-0003.xml. [PMID: 29466235 DOI: 10.1515/hmbci-2018-0003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 01/22/2018] [Indexed: 12/17/2022]
Abstract
The white adipose tissue (WAT) exhibits great plasticity and can undergo "browning" and acquire features of the brown adipose tissue (BAT), which takes place following cold exposure, chronic endurance exercise or β3-adrenergic stimulation. WAT that underwent browning is characterized by the presence of "beige" adipocytes, which are morphologically similar to brown adipocytes, express uncoupling protein 1 (UCP1) and are considered thermogenically competent. Thus, inducing a BAT-like phenotype in the WAT could promote energy dissipation within this depot, reducing the availability of substrate that would otherwise be stored in the WAT. Importantly, BAT in humans only represents a small proportion of total body mass, which limits the thermogenic capacity of this tissue. Therefore, browning of the WAT could significantly expand the energy-dissipating capacity of the organism and be of therapeutic value in the treatment of metabolic diseases. However, the question remains as to whether WAT indeed changes its metabolic profile from an essentially fat storage/release compartment to an energy dissipating compartment that functions much like BAT. Here, we discuss the differences with respect to thermogenic capacity and metabolic characteristics between white and beige adipocytes to determine whether the latter cells indeed significantly enhance their capacity to dissipate energy through UCP1-mediated mitochondrial uncoupling or by the activation of alternative UCP1-independent futile cycles.
Collapse
Affiliation(s)
- Diane M Sepa-Kishi
- Muscle Health Research Center, School of Kinesiology and Health Science, York University, Toronto, Canada
| | - Rolando B Ceddia
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, 4700 Keele St., North York, Ontario, M3J 13P, Canada, Phone: 416-736-2100 (Ext. 77204), Fax: 416-736-5774
| |
Collapse
|
29
|
Purity matters: A workflow for the valid high-resolution lipid profiling of mitochondria from cell culture samples. Sci Rep 2016; 6:21107. [PMID: 26892142 PMCID: PMC4759577 DOI: 10.1038/srep21107] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 01/15/2016] [Indexed: 11/09/2022] Open
Abstract
Subcellular lipidomics is a novel field of research that requires the careful combination of several pre-analytical and analytical steps. To define a reliable strategy for mitochondrial lipid profiling, we performed a systematic comparison of different mitochondria isolation procedures by western blot analyses and comprehensive high-resolution lipidomics. Using liver-derived HepG2 cells, we compared three common mitochondria isolation methods, differential centrifugation (DC), ultracentrifugation (UC) and a magnetic bead-assisted method (MACS). In total, 397 lipid species, including 32 cardiolipins, could be quantified in only 100 μg (by protein) of purified mitochondria. Mitochondria isolated by UC showed the highest enrichment in the mitochondria-specific cardiolipins as well as their precursors, phosphatidylglycerols. Mitochondrial fractions obtained by the commonly used DC and the more recent MACS method contained substantial contaminations by other organelles. Employing these isolation methods when performing lipidomics analyses from cell culture mitochondria may lead to inaccurate results. To conclude, we present a protocol how to obtain reliable mitochondria-specific lipid profiles from cell culture samples and show that quality controls are indispensable when performing mitochondria lipidomics.
Collapse
|
30
|
Schöttl T, Kappler L, Fromme T, Klingenspor M. Limited OXPHOS capacity in white adipocytes is a hallmark of obesity in laboratory mice irrespective of the glucose tolerance status. Mol Metab 2015; 4:631-42. [PMID: 26413469 PMCID: PMC4563017 DOI: 10.1016/j.molmet.2015.07.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 07/03/2015] [Accepted: 07/07/2015] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE Several human and rodent obesity studies speculate on a causal link between altered white adipocyte mitochondria in the obese state and changes in glucose homeostasis. We here aimed to dissect whether alterations in white adipocyte mitochondrial respiratory function are a specific phenomenon of obesity or impaired glucose tolerance or both. METHODS Mature white adipocytes were purified from posterior subcutaneous and intraabdominal epididymal fat of four murine obesity models characterized by either impaired or normal oral glucose tolerance. Bioenergetic profiles, including basal, leak, and maximal respiration, were generated using high-resolution respirometry. Cell respiratory control ratios were calculated to evaluate mitochondrial respiratory function. RESULTS Maximal respiration capacity and cell respiratory control ratios were diminished in white adipocytes of each of the four murine obesity models, both in the absence and the presence of impaired glucose tolerance. Limitation was more pronounced in adipocytes of intraabdominal versus subcutaneous fat. CONCLUSION Reduced mitochondrial respiratory capacity in white adipocytes is a hallmark of murine obesity irrespective of the glucose tolerance status. Impaired respiratory capacity in white adipocytes solely is not sufficient for the development of systemic glucose intolerance.
Collapse
Affiliation(s)
| | | | | | - Martin Klingenspor
- Molecular Nutritional Medicine, Technische Universität München, Else Kröner Fresenius Center for Nutritional Medicine, Freising, Germany
| |
Collapse
|