1
|
Lu B, Guo S, Zhao J, Wang X, Zhou B. Adipose knockout of H-ferritin improves energy metabolism in mice. Mol Metab 2024; 80:101871. [PMID: 38184276 PMCID: PMC10803945 DOI: 10.1016/j.molmet.2024.101871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 12/12/2023] [Accepted: 01/02/2024] [Indexed: 01/08/2024] Open
Abstract
OBJECTIVE Ferritin, the principal iron storage protein, is essential to iron homeostasis. How iron homeostasis affects the adipose tissue is not well understood. We investigated the role of ferritin heavy chain in adipocytes in energy metabolism. METHODS We generated adipocyte-specific ferritin heavy chain (Fth, also known as Fth1) knockout mice, herein referred to as FthAKO. These mice were analyzed for iron homeostasis, oxidative stress, mitochondrial biogenesis and activity, adaptive thermogenesis, insulin sensitivity, and metabolic measurements. Mouse embryonic fibroblasts and primary mouse adipocytes were used for in vitro experiments. RESULTS In FthAKO mice, the adipose iron homeostasis was disrupted, accompanied by elevated expression of adipokines, dramatically induced heme oxygenase 1(Hmox1) expression, and a notable decrease in the mitochondrial ROS level. Cytosolic ROS elevation in the adipose tissue of FthAKO mice was very mild, and we only observed this in the brown adipose tissue (BAT) but not in the white adipose tissue (WAT). FthAKO mice presented an altered metabolic profile and showed increased insulin sensitivity, glucose tolerance, and improved adaptive thermogenesis. Interestingly, loss of ferritin resulted in enhanced mitochondrial respiration capacity and a preference for lipid metabolism. CONCLUSIONS These findings indicate that ferritin in adipocytes is indispensable to intracellular iron homeostasis and regulates systemic lipid and glucose metabolism.
Collapse
Affiliation(s)
- Binyu Lu
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Shanshan Guo
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jialin Zhao
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Xiaoting Wang
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Bing Zhou
- Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
| |
Collapse
|
2
|
Moreno-Navarrete JM, Fernández-Real JM. Iron: The silent culprit in your adipose tissue. Obes Rev 2024; 25:e13647. [PMID: 37789591 DOI: 10.1111/obr.13647] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/27/2023] [Accepted: 09/09/2023] [Indexed: 10/05/2023]
Abstract
Iron plays a vital role in essential biological processes and requires precise regulation within the body. Dysregulation of iron homeostasis, characterized by increased serum ferritin levels and excessive accumulation of iron in the liver, adipose tissue, and skeletal muscle, is associated with obesity and insulin resistance. Notably, iron excess in adipose tissue promotes adipose tissue dysfunction. As optimal adipose tissue function is crucial for maintaining a healthy phenotype in obesity, a comprehensive understanding of iron homeostasis in adipose tissue is imperative for designing new therapeutic approaches to improve and prevent adipose tissue dysfunction. Here, we conducted a review of relevant studies, focusing on and providing valuable insights into the intricate interplay between iron and adipose tissue. It sheds light on the impact of iron on adipogenesis and the physiology of both white and brown adipose tissue. Furthermore, we highlight the critical role of key modulators, such as cytosolic aconitase, mitochondria, and macrophages, in maintaining iron homeostasis within adipose tissue.
Collapse
Affiliation(s)
- José María Moreno-Navarrete
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Girona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - José Manuel Fernández-Real
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), Girona, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Department of Medical Sciences, University of Girona, Girona, Spain
| |
Collapse
|
3
|
Sabaratnam R, Hansen DR, Svenningsen P. White adipose tissue mitochondrial bioenergetics in metabolic diseases. Rev Endocr Metab Disord 2023; 24:1121-1133. [PMID: 37558853 DOI: 10.1007/s11154-023-09827-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/19/2023] [Indexed: 08/11/2023]
Abstract
White adipose tissue (WAT) is an important endocrine organ that regulates systemic energy metabolism. In metabolically unhealthy obesity, adipocytes become dysfunctional through hypertrophic mechanisms associated with a reduced endocrine function, reduced mitochondrial function, but increased inflammation, fibrosis, and extracellular remodelling. A pathologic WAT remodelling promotes systemic lipotoxicity characterized by fat accumulation in tissues such as muscle and liver, leading to systemic insulin resistance and type 2 diabetes. Several lines of evidence from human and animal studies suggest a link between unhealthy obesity and adipocyte mitochondrial dysfunction, and interventions that improve mitochondrial function may reduce the risk of obesity-associated diseases. This review discusses the importance of mitochondrial function and metabolism in human adipocyte biology and intercellular communication mechanisms within WAT. Moreover, a selected interventional approach for better adipocyte mitochondrial metabolism in humans is reviewed. A greater understanding of mitochondrial bioenergetics in WAT might provide novel therapeutic opportunities to prevent or restore dysfunctional adipose tissue in obesity-associated diseases.
Collapse
Affiliation(s)
- Rugivan Sabaratnam
- Department of Clinical Research, University of Southern Denmark, Odense C, DK-5000, Denmark.
- Steno Diabetes Center Odense, Odense University Hospital, Odense C, DK-5000, Denmark.
- Department of Molecular Medicine, Cardiovascular and Renal Research, University of Southern Denmark, J. B. Winsløws Vej 21,3, Odense C, DK-5000, Denmark.
| | - Didde Riisager Hansen
- Steno Diabetes Center Odense, Odense University Hospital, Odense C, DK-5000, Denmark
- Department of Molecular Medicine, Cardiovascular and Renal Research, University of Southern Denmark, J. B. Winsløws Vej 21,3, Odense C, DK-5000, Denmark
| | - Per Svenningsen
- Department of Molecular Medicine, Cardiovascular and Renal Research, University of Southern Denmark, J. B. Winsløws Vej 21,3, Odense C, DK-5000, Denmark.
| |
Collapse
|
4
|
Schleh MW, Caslin HL, Garcia JN, Mashayekhi M, Srivastava G, Bradley AB, Hasty AH. Metaflammation in obesity and its therapeutic targeting. Sci Transl Med 2023; 15:eadf9382. [PMID: 37992150 PMCID: PMC10847980 DOI: 10.1126/scitranslmed.adf9382] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 08/29/2023] [Indexed: 11/24/2023]
Abstract
Obesity-associated inflammation is a systemic process that affects all metabolic organs. Prominent among these is adipose tissue, where cells of the innate and adaptive immune system are markedly changed in obesity, implicating these cells in a range of processes linking immune memory to metabolic regulation. Furthermore, weight loss and weight cycling have unexpected effects on adipose tissue immune populations. Here, we review the current literature on the roles of various immune cells in lean and obese adipose tissue. Within this context, we discuss pharmacological and nonpharmacological approaches to obesity treatment and their impact on systemic inflammation.
Collapse
Affiliation(s)
- Michael W. Schleh
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Heather L. Caslin
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jamie N. Garcia
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Mona Mashayekhi
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Gitanjali Srivastava
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Weight Loss Center, Vanderbilt University Medical Center, Nashville, TN 37204 USA
| | - Anna B. Bradley
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Weight Loss Center, Vanderbilt University Medical Center, Nashville, TN 37204 USA
- VA Tennessee Valley Healthcare System, Nashville, TN 37212, USA
| | - Alyssa H. Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- VA Tennessee Valley Healthcare System, Nashville, TN 37212, USA
| |
Collapse
|
5
|
Oliveras-Cañellas N, Latorre J, Santos-González E, Lluch A, Ortega F, Mayneris-Perxachs J, Fernández-Real JM, Moreno-Navarrete JM. Inflammatory response to bacterial lipopolysaccharide drives iron accumulation in human adipocytes. Biomed Pharmacother 2023; 166:115428. [PMID: 37677967 DOI: 10.1016/j.biopha.2023.115428] [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: 06/30/2023] [Revised: 08/23/2023] [Accepted: 08/30/2023] [Indexed: 09/09/2023] Open
Abstract
The association among increased inflammation, disrupted iron homeostasis, and adipose tissue dysfunction in obesity has been widely recognized. However, the specific impact of inflammation on iron homeostasis during human adipogenesis and in adipocytes remains poorly understood. In this study, we investigated the effects of bacterial lipopolysaccharide (LPS) on iron homeostasis during human adipocyte differentiation, in fully differentiated adipocytes, and in human adipose tissue. We found that LPS-induced inflammation hindered adipogenesis and led to a gene expression profile indicative of intracellular iron accumulation. This was accompanied by increased expression of iron importers (TFRC and SLC11A2), markers of intracellular iron accumulation (FTH, CYBA, FTL, and LCN2), and decreased expression of iron exporter-related genes (SLC40A1), concomitant with elevated intracellular iron levels. Mechanistically, RNA-seq analysis and gene knockdown experiments revealed the significant involvement of iron importers SLC39A14, SLC39A8, and STEAP4 in LPS-induced intracellular iron accumulation in human adipocytes. Notably, markers of LPS signaling pathway-related inflammation were also associated with a gene expression pattern indicative of intracellular iron accumulation in human adipose tissue, corroborating the link between LPS-induced inflammation and iron accumulation at the tissue level. In conclusion, our findings demonstrate that induction of adipocyte inflammation disrupts iron homeostasis, resulting in adipocyte iron overload.
Collapse
Affiliation(s)
- Núria Oliveras-Cañellas
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Jessica Latorre
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Elena Santos-González
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Aina Lluch
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Francisco Ortega
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Jordi Mayneris-Perxachs
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - José-Manuel Fernández-Real
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain; Department of Medicine, Universitat de Girona, Girona, Spain.
| | - José María Moreno-Navarrete
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain.
| |
Collapse
|
6
|
Preda A, Carbone F, Tirandi A, Montecucco F, Liberale L. Obesity phenotypes and cardiovascular risk: From pathophysiology to clinical management. Rev Endocr Metab Disord 2023; 24:901-919. [PMID: 37358728 PMCID: PMC10492705 DOI: 10.1007/s11154-023-09813-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/31/2023] [Indexed: 06/27/2023]
Abstract
Obesity epidemic reached the dimensions of a real global health crisis with more than one billion people worldwide living with obesity. Multiple obesity-related mechanisms cause structural, functional, humoral, and hemodynamic alterations with cardiovascular (CV) deleterious effects. A correct assessment of the cardiovascular risk in people with obesity is critical for reducing mortality and preserving quality of life. The correct identification of the obesity status remains difficult as recent evidence suggest that different phenotypes of obesity exist, each one associated with different degrees of CV risk. Diagnosis of obesity cannot depend only on anthropometric parameters but should include a precise assessment of the metabolic status. Recently, the World Heart Federation and World Obesity Federation provided an action plan for management of obesity-related CV risk and mortality, stressing for the instauration of comprehensive structured programs encompassing multidisciplinary teams. In this review we aim at providing an updated summary regarding the different obesity phenotypes, their specific effects on CV risk and differences in clinical management.
Collapse
Affiliation(s)
| | - Federico Carbone
- IRCCS Ospedale Policlinico San Martino Genoa - Italian Cardiovascular Network, Genoa, Italy
- Department of Internal Medicine, University of Genoa, 6 viale Benedetto XV, 16132, Genoa, Italy
| | - Amedeo Tirandi
- IRCCS Ospedale Policlinico San Martino Genoa - Italian Cardiovascular Network, Genoa, Italy
- Department of Internal Medicine, University of Genoa, 6 viale Benedetto XV, 16132, Genoa, Italy
| | - Fabrizio Montecucco
- IRCCS Ospedale Policlinico San Martino Genoa - Italian Cardiovascular Network, Genoa, Italy.
- Department of Internal Medicine, University of Genoa, 6 viale Benedetto XV, 16132, Genoa, Italy.
| | - Luca Liberale
- IRCCS Ospedale Policlinico San Martino Genoa - Italian Cardiovascular Network, Genoa, Italy
- Department of Internal Medicine, University of Genoa, 6 viale Benedetto XV, 16132, Genoa, Italy
| |
Collapse
|
7
|
Sprenkle NT, Winn NC, Bunn KE, Zhao Y, Park DJ, Giese BG, Karijolich JJ, Ansel KM, Serezani CH, Hasty AH, Pua HH. The miR-23-27-24 clusters drive lipid-associated macrophage proliferation in obese adipose tissue. Cell Rep 2023; 42:112928. [PMID: 37542720 PMCID: PMC10712211 DOI: 10.1016/j.celrep.2023.112928] [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: 01/10/2023] [Revised: 06/19/2023] [Accepted: 07/17/2023] [Indexed: 08/07/2023] Open
Abstract
Identifying molecular circuits that control adipose tissue macrophage (ATM) function is necessary to understand how ATMs contribute to tissue homeostasis and obesity-induced insulin resistance. In this study, we find that mice with a myeloid-specific knockout of the miR-23-27-24 clusters of microRNAs (miRNAs) gain less weight on a high-fat diet but exhibit worsened glucose and insulin tolerance. Analysis of ATMs from these mice shows selectively reduced numbers and proliferation of a recently reported subset of lipid-associated CD9+Trem2+ ATMs (lipid-associated macrophages [LAMs]). Leveraging the role of miRNAs to control networks of genes, we use RNA sequencing (RNA-seq), functional screens, and biochemical assays to identify candidate target transcripts that regulate proliferation-associated signaling. We determine that miR-23 directly targets the mRNA of Eif4ebp2, a gene that restricts protein synthesis and proliferation in macrophages. Altogether, our study demonstrates that control of proliferation of a protective subset of LAMs by noncoding RNAs contributes to protection against diet-induced obesity metabolic dysfunction.
Collapse
Affiliation(s)
- Neil T Sprenkle
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Nathan C Winn
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Kaitlyn E Bunn
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yang Zhao
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Deborah J Park
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Brenna G Giese
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John J Karijolich
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Center for Immunobiology and Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Vanerbilt-Ingram Cancer Center, Nashville, TN, USA
| | - K Mark Ansel
- Department of Microbiology and Immunology and Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA, USA
| | - C Henrique Serezani
- Vanderbilt Center for Immunobiology and Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA; Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alyssa H Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA; Vanderbilt Center for Immunobiology and Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA; Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
| | - Heather H Pua
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Center for Immunobiology and Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA.
| |
Collapse
|
8
|
Hilton C, Sabaratnam R, Drakesmith H, Karpe F. Iron, glucose and fat metabolism and obesity: an intertwined relationship. Int J Obes (Lond) 2023; 47:554-563. [PMID: 37029208 PMCID: PMC10299911 DOI: 10.1038/s41366-023-01299-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 03/08/2023] [Accepted: 03/16/2023] [Indexed: 04/09/2023]
Abstract
A bidirectional relationship exists between adipose tissue metabolism and iron regulation. Total body fat, fat distribution and exercise influence iron status and components of the iron-regulatory pathway, including hepcidin and erythroferrone. Conversely, whole body and tissue iron stores associate with fat mass and distribution and glucose and lipid metabolism in adipose tissue, liver, and muscle. Manipulation of the iron-regulatory proteins erythroferrone and erythropoietin affects glucose and lipid metabolism. Several lines of evidence suggest that iron accumulation and metabolism may play a role in the development of metabolic diseases including obesity, type 2 diabetes, hyperlipidaemia and non-alcoholic fatty liver disease. In this review we summarise the current understanding of the relationship between iron homoeostasis and metabolic disease.
Collapse
Affiliation(s)
- Catriona Hilton
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK.
| | - Rugivan Sabaratnam
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
- Steno Diabetes Center Odense, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Hal Drakesmith
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| |
Collapse
|
9
|
Li X, Ren Y, Chang K, Wu W, Griffiths HR, Lu S, Gao D. Adipose tissue macrophages as potential targets for obesity and metabolic diseases. Front Immunol 2023; 14:1153915. [PMID: 37153549 PMCID: PMC10154623 DOI: 10.3389/fimmu.2023.1153915] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 04/04/2023] [Indexed: 05/09/2023] Open
Abstract
Macrophage infiltration into adipose tissue is a key pathological factor inducing adipose tissue dysfunction and contributing to obesity-induced inflammation and metabolic disorders. In this review, we aim to present the most recent research on macrophage heterogeneity in adipose tissue, with a focus on the molecular targets applied to macrophages as potential therapeutics for metabolic diseases. We begin by discussing the recruitment of macrophages and their roles in adipose tissue. While resident adipose tissue macrophages display an anti-inflammatory phenotype and promote the development of metabolically favorable beige adipose tissue, an increase in pro-inflammatory macrophages in adipose tissue has negative effects on adipose tissue function, including inhibition of adipogenesis, promotion of inflammation, insulin resistance, and fibrosis. Then, we presented the identities of the newly discovered adipose tissue macrophage subtypes (e.g. metabolically activated macrophages, CD9+ macrophages, lipid-associated macrophages, DARC+ macrophages, and MFehi macrophages), the majority of which are located in crown-like structures within adipose tissue during obesity. Finally, we discussed macrophage-targeting strategies to ameliorate obesity-related inflammation and metabolic abnormalities, with a focus on transcriptional factors such as PPARγ, KLF4, NFATc3, and HoxA5, which promote macrophage anti-inflammatory M2 polarization, as well as TLR4/NF-κB-mediated inflammatory pathways that activate pro-inflammatory M1 macrophages. In addition, a number of intracellular metabolic pathways closely associated with glucose metabolism, oxidative stress, nutrient sensing, and circadian clock regulation were examined. Understanding the complexities of macrophage plasticity and functionality may open up new avenues for the development of macrophage-based treatments for obesity and other metabolic diseases.
Collapse
Affiliation(s)
- Xirong Li
- Institute of Molecular and Translational Medicine, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Yakun Ren
- Institute of Molecular and Translational Medicine, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Kewei Chang
- Institute of Molecular and Translational Medicine, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, China
- Key Laboratory of Environment and Genes Related to Diseases (Xi’an Jiaotong University), Ministry of Education, Xi’an, China
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Center, Xi’an, China
| | - Wenlong Wu
- Institute of Molecular and Translational Medicine, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Helen R. Griffiths
- Swansea University Medical School, Swansea University, Swansea, United Kingdom
| | - Shemin Lu
- Institute of Molecular and Translational Medicine, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, China
- Key Laboratory of Environment and Genes Related to Diseases (Xi’an Jiaotong University), Ministry of Education, Xi’an, China
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, China
| | - Dan Gao
- Institute of Molecular and Translational Medicine, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, China
- Key Laboratory of Environment and Genes Related to Diseases (Xi’an Jiaotong University), Ministry of Education, Xi’an, China
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Center, Xi’an, China
| |
Collapse
|
10
|
Mayneris-Perxachs J, Moreno-Navarrete JM, Fernández-Real JM. The role of iron in host-microbiota crosstalk and its effects on systemic glucose metabolism. Nat Rev Endocrinol 2022; 18:683-698. [PMID: 35986176 DOI: 10.1038/s41574-022-00721-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/01/2022] [Indexed: 11/09/2022]
Abstract
Iron is critical for the appearance and maintenance of life on Earth. Almost all organisms compete or cooperate for iron acquisition, demonstrating the importance of this essential element for the biological and physiological processes that are key for the preservation of metabolic homeostasis. In humans and other mammals, the bidirectional interactions between the bacterial component of the gut microbiota and the host for iron acquisition shape both host and microbiota metabolism. Bacterial functions influence host iron absorption, whereas the intake of iron, iron deficiency and iron excess in the host affect bacterial biodiversity, taxonomy and function, resulting in changes in bacterial virulence. These consequences of the host-microbial crosstalk affect systemic levels of iron, its storage in different tissues and host glucose metabolism. At the interface between the host and the microbiota, alterations in the host innate immune system and in circulating soluble factors that regulate iron (that is, hepcidin, lipocalin 2 and lactoferrin) are associated with metabolic disease. In fact, patients with obesity-associated metabolic dysfunction and insulin resistance exhibit dysregulation in iron homeostasis and alterations in their gut microbiota profile. From an evolutionary point of view, the pursuit of two important nutrients - glucose and iron - has probably driven human evolution towards the most efficient pathways and genes for human survival and health.
Collapse
Affiliation(s)
- Jordi Mayneris-Perxachs
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IDIBGI), Girona, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain
| | - José María Moreno-Navarrete
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IDIBGI), Girona, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain
| | - José Manuel Fernández-Real
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IDIBGI), Girona, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain.
- Department of Medicine, Universitat de Girona, Girona, Spain.
| |
Collapse
|
11
|
Hasty AH. Iron at the intersection of macrophage-adipocyte interactions. Nat Metab 2022; 4:1434-1435. [PMID: 36329218 DOI: 10.1038/s42255-022-00663-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Alyssa H Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA.
- VA Tennessee Valley Healthcare System, Nashville, TN, USA.
| |
Collapse
|
12
|
Joffin N, Gliniak CM, Funcke JB, Paschoal VA, Crewe C, Chen S, Gordillo R, Kusminski CM, Oh DY, Geldenhuys WJ, Scherer PE. Adipose tissue macrophages exert systemic metabolic control by manipulating local iron concentrations. Nat Metab 2022; 4:1474-1494. [PMID: 36329217 DOI: 10.1038/s42255-022-00664-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 09/20/2022] [Indexed: 11/05/2022]
Abstract
Iron is essential to many fundamental biological processes, but its cellular compartmentalization and concentration must be tightly controlled. Although iron overload can contribute to obesity-associated metabolic deterioration, the subcellular localization and accumulation of iron in adipose tissue macrophages is largely unknown. Here, we show that macrophage mitochondrial iron levels control systemic metabolism in male mice by altering adipocyte iron concentrations. Using various transgenic mouse models to manipulate the macrophage mitochondrial matrix iron content in an inducible fashion, we demonstrate that lowering macrophage mitochondrial matrix iron increases numbers of M2-like macrophages in adipose tissue, lowers iron levels in adipocytes, attenuates inflammation and protects from high-fat-diet-induced metabolic deterioration. Conversely, elevating macrophage mitochondrial matrix iron increases M1-like macrophages and iron levels in adipocytes, exacerbates inflammation and worsens high-fat-diet-induced metabolic dysfunction. These phenotypes are robustly reproduced by transplantation of a small amount of fat from transgenic to wild-type mice. Taken together, we identify macrophage mitochondrial iron levels as a crucial determinant of systemic metabolic homeostasis in mice.
Collapse
Affiliation(s)
- Nolwenn Joffin
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Christy M Gliniak
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jan-Bernd Funcke
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vivian A Paschoal
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Clair Crewe
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Cell Biology, Washington University, St. Louis, MO, USA
| | - Shiuhwei Chen
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ruth Gordillo
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Christine M Kusminski
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Da Young Oh
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Werner J Geldenhuys
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
13
|
Ameka MK, Beavers WN, Shaver CM, Ware LB, Kerchberger VE, Schoenfelt KQ, Sun L, Koyama T, Skaar EP, Becker L, Hasty AH. An Iron Refractory Phenotype in Obese Adipose Tissue Macrophages Leads to Adipocyte Iron Overload. Int J Mol Sci 2022; 23:ijms23137417. [PMID: 35806422 PMCID: PMC9267114 DOI: 10.3390/ijms23137417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 02/04/2023] Open
Abstract
Adipocyte iron overload is a maladaptation associated with obesity and insulin resistance. The objective of the current study was to determine whether and how adipose tissue macrophages (ATMs) regulate adipocyte iron concentrations and whether this is impacted by obesity. Using bone marrow-derived macrophages (BMDMs) polarized to M0, M1, M2, or metabolically activated (MMe) phenotypes, we showed that MMe BMDMs and ATMs from obese mice have reduced expression of several iron-related proteins. Furthermore, the bioenergetic response to iron in obese ATMs was hampered. ATMs from iron-injected lean mice increased their glycolytic and respiratory capacities, thus maintaining metabolic flexibility, while ATMs from obese mice did not. Using an isotope-based system, we found that iron exchange between BMDMs and adipocytes was regulated by macrophage phenotype. At the end of the co-culture, MMe macrophages transferred and received more iron from adipocytes than M0, M1, and M2 macrophages. This culminated in a decrease in total iron in MMe macrophages and an increase in total iron in adipocytes compared with M2 macrophages. Taken together, in the MMe condition, the redistribution of iron is biased toward macrophage iron deficiency and simultaneous adipocyte iron overload. These data suggest that obesity changes the communication of iron between adipocytes and macrophages and that rectifying this iron communication channel may be a novel therapeutic target to alleviate insulin resistance.
Collapse
Affiliation(s)
- Magdalene K. Ameka
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN 37212, USA;
| | - William N. Beavers
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA;
| | - Ciara M. Shaver
- Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN 37212, USA; (C.M.S.); (L.B.W.); (V.E.K.)
| | - Lorraine B. Ware
- Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN 37212, USA; (C.M.S.); (L.B.W.); (V.E.K.)
- Department of Pathology, Microbiology, and Immunology, School of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212, USA;
| | - Vern Eric Kerchberger
- Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN 37212, USA; (C.M.S.); (L.B.W.); (V.E.K.)
- Department of Pathology, Microbiology, and Immunology, School of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212, USA;
| | - Kelly Q. Schoenfelt
- Department of Cancer Research, University of Chicago, Chicago, IL 60637, USA; (K.Q.S.); (L.B.)
| | - Lili Sun
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN 37212, USA; (L.S.); (T.K.)
| | - Tatsuki Koyama
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN 37212, USA; (L.S.); (T.K.)
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, School of Medicine, Vanderbilt University Medical Center, Nashville, TN 37212, USA;
| | - Lev Becker
- Department of Cancer Research, University of Chicago, Chicago, IL 60637, USA; (K.Q.S.); (L.B.)
| | - Alyssa H. Hasty
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN 37212, USA;
- VA Tennessee Valley Healthcare System, Nashville, TN 37212, USA
- Correspondence:
| |
Collapse
|
14
|
Ameka M, Hasty AH. Paying the Iron Price: Liver Iron Homeostasis and Metabolic Disease. Compr Physiol 2022; 12:3641-3663. [PMID: 35766833 PMCID: PMC10155403 DOI: 10.1002/cphy.c210039] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Iron is an essential metal element whose bioavailability is tightly regulated. Under normal conditions, systemic and cellular iron homeostases are synchronized for optimal function, based on the needs of each system. During metabolic dysfunction, this synchrony is lost, and markers of systemic iron homeostasis are no longer coupled to the iron status of key metabolic organs such as the liver and adipose tissue. The effects of dysmetabolic iron overload syndrome in the liver have been tied to hepatic insulin resistance, nonalcoholic fatty liver disease, and nonalcoholic steatohepatitis. While the existence of a relationship between iron dysregulation and metabolic dysfunction has long been acknowledged, identifying correlative relationships is complicated by the prognostic reliance on systemic measures of iron homeostasis. What is lacking and perhaps more informative is an understanding of how cellular iron homeostasis changes with metabolic dysfunction. This article explores bidirectional relationships between different proteins involved in iron homeostasis and metabolic dysfunction in the liver. © 2022 American Physiological Society. Compr Physiol 12:3641-3663, 2022.
Collapse
Affiliation(s)
- Magdalene Ameka
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Alyssa H Hasty
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA.,VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA
| |
Collapse
|
15
|
Winn NC, Wolf EM, Cottam MA, Bhanot M, Hasty AH. Myeloid-specific deletion of ferroportin impairs macrophage bioenergetics but is disconnected from systemic insulin action in adult mice. Am J Physiol Endocrinol Metab 2021; 321:E376-E391. [PMID: 34338042 PMCID: PMC8461794 DOI: 10.1152/ajpendo.00116.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/28/2021] [Accepted: 07/25/2021] [Indexed: 12/28/2022]
Abstract
Tissue iron overload is associated with insulin resistance and mitochondrial dysfunction in rodents and humans; however, the mechanisms or cell types that mediate this phenotype are not completely understood. Macrophages (Mɸs) are known to contribute to iron handling; thus, we hypothesized that perturbed iron handling by Mɸs impairs mitochondrial energetics and evokes systemic insulin resistance in mice. Male and female mice with myeloid-targeted (LysMCre) deletion of the canonical iron exporter, ferroportin (Fpn, encoded by Slc40a1), floxed littermates, and C57BL/6J wild-type mice were used to test our hypotheses. Myeloid-targeted deletion of Fpn evoked multitissue iron accumulation and reduced mitochondrial respiration in bone marrow-derived Mɸs, liver leukocytes, and Mɸ-enriched populations from adipose tissue (AT). In addition, a single bolus of exogenous iron administered to C57BL/6J mice phenocopied the loss of Fpn, resulting in a reduction in maximal and mitochondrial reserve capacity in Mɸ-enriched cellular fractions from liver and AT. In vivo exogenous iron chelation restored mitochondrial reserve capacity in liver leukocytes from Fpn LysMCre mice, but had no effect in AT myeloid populations. However, despite the impairments in mitochondrial respiration, neither loss of myeloid-specific Fpn nor exogenous iron overload perturbed glucose homeostasis or systemic insulin action in lean or obese mice, whereas aging coupled with lifelong loss of Fpn unmasked glucose intolerance. Together these data demonstrate that iron handling is critical for the maintenance of macrophage mitochondrial function, but perturbing myeloid iron flux via the loss of Fpn action is not sufficient to evoke systemic insulin resistance in young adult mice. These findings also suggest that if Mɸs are capable of storing iron properly, they have a pronounced ability to withstand iron excess without evoking overt collateral damage and associated insulin resistance that may be age dependent.NEW & NOTEWORTHY We used myeloid-specific knockout of ferroportin to determine whether macrophage iron enrichment alters systemic metabolism. We found that macrophages in several tissues showed mitochondrial defects such as a reduction in mitochondrial reserve capacity. However, insulin action in the mice was preserved. These findings also suggest that Mɸs have a pronounced ability to withstand iron excess without evoking overt collateral damage and associated insulin resistance, which appears to be age dependent.
Collapse
Affiliation(s)
- Nathan C Winn
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Elysa M Wolf
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Matthew A Cottam
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Monica Bhanot
- Division of Diabetes, Endocrinology and Metabolism, Vanderbilt Medical Center, Nashville, Tennessee
| | - Alyssa H Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
- VA Tennessee Valley Healthcare System, Nashville, Tennessee
| |
Collapse
|
16
|
De R, Prakash KU, Edison ES. Complex Interactions in Regulation of Haematopoiesis-An Unexplored Iron Mine. Genes (Basel) 2021; 12:genes12081270. [PMID: 34440444 PMCID: PMC8391430 DOI: 10.3390/genes12081270] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/10/2021] [Accepted: 07/13/2021] [Indexed: 12/14/2022] Open
Abstract
Iron is one of the most abundant metals on earth and is vital for the growth and survival of life forms. It is crucial for the functioning of plants and animals as it is an integral component of the photosynthetic apparatus and innumerable proteins and enzymes. It plays a pivotal role in haematopoiesis and affects the development and differentiation of different haematopoietic lineages, apart from its obvious necessity in erythropoiesis. A large amount of iron stores in humans is diverted towards the latter process, as iron is an indispensable component of haemoglobin. This review summarises the important players of iron metabolism and homeostasis that have been discovered in recent years and highlights the overall significance of iron in haematopoiesis. Its role in maintenance of haematopoietic stem cells, influence on differentiation of varied haematopoietic lineages and consequences of iron deficiency/overloading on development and maturation of different groups of haematopoietic cells have been discussed.
Collapse
|
17
|
Félix I, Jokela H, Karhula J, Kotaja N, Savontaus E, Salmi M, Rantakari P. Single-Cell Proteomics Reveals the Defined Heterogeneity of Resident Macrophages in White Adipose Tissue. Front Immunol 2021; 12:719979. [PMID: 34381461 PMCID: PMC8350344 DOI: 10.3389/fimmu.2021.719979] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/12/2021] [Indexed: 12/24/2022] Open
Abstract
Adipose tissue macrophages (ATMs) regulate homeostasis and contribute to the metabolically harmful chronic inflammation in obese individuals. While evident heterogeneity of resident ATMs has been described previously, their phenotype, developmental origin, and functionality remain inconsistent. We analyzed white adipose tissue (WAT) during homeostasis and diet interventions using comprehensive and unbiased single-cell mass cytometry and genetic lineage tracking models. We now provide a uniform definition of individual subsets of resident ATMs. We show that in lean mice, WAT co-harbors eight kinetically evolving CD206+ macrophage subpopulations (defined by TIM4, CD163, and MHC II) and two CD206- macrophage subpopulations. TIM4-CD163+, TIM4-CD163- and CD206- macrophage populations are largely bone marrow-derived, while the proliferating TIM4+CD163+ subpopulation is of embryonic origin. All macrophage subtypes are active in phagocytosis, endocytosis, and antigen processing in vitro, whereas TIM4+CD163+ cells are superior in scavenging in vivo. A high-fat diet induces massive infiltration of CD206- macrophages and selective down-regulation of MHC II on TIM4+ macrophages. These changes are reversed by dietary intervention. Thus, the developmental origin and environment jointly regulate the functional malleability of resident ATMs.
Collapse
Affiliation(s)
- Inês Félix
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.,Research Centre for Infection and Immunity, Institute of Biomedicine, University of Turku, Turku, Finland.,InFLAMES Research Flagship Center, University of Turku, Turku, Finland
| | - Heli Jokela
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.,Research Centre for Infection and Immunity, Institute of Biomedicine, University of Turku, Turku, Finland.,InFLAMES Research Flagship Center, University of Turku, Turku, Finland
| | - Joonas Karhula
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.,Research Centre for Infection and Immunity, Institute of Biomedicine, University of Turku, Turku, Finland.,InFLAMES Research Flagship Center, University of Turku, Turku, Finland
| | - Noora Kotaja
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Eriika Savontaus
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland.,Clinical Pharmacology, Turku University Hospital, Turku, Finland
| | - Marko Salmi
- InFLAMES Research Flagship Center, University of Turku, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
| | - Pia Rantakari
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.,Research Centre for Infection and Immunity, Institute of Biomedicine, University of Turku, Turku, Finland.,InFLAMES Research Flagship Center, University of Turku, Turku, Finland
| |
Collapse
|
18
|
Macrophage metabolic adaptation to heme detoxification involves CO-dependent activation of the pentose phosphate pathway. Blood 2021; 136:1535-1548. [PMID: 32556090 DOI: 10.1182/blood.2020004964] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/08/2020] [Indexed: 02/07/2023] Open
Abstract
Heme is an essential cofactor for numerous cellular functions, but release of free heme during hemolysis results in oxidative tissue damage, vascular dysfunction, and inflammation. Macrophages play a key protective role in heme clearance; however, the mechanisms that regulate metabolic adaptations that are required for effective heme degradation remain unclear. Here we demonstrate that heme loading drives a unique bioenergetic switch in macrophages, which involves a metabolic shift from oxidative phosphorylation toward glucose consumption. Metabolomic and transcriptional analysis of heme-loaded macrophages revealed that glucose is funneled into the pentose phosphate pathway (PPP), which is indispensable for efficient heme detoxification and is required to maintain redox homeostasis. We demonstrate that the metabolic shift to the PPP is controlled by heme oxygenase-dependent generation of carbon monoxide (CO). Finally, we show that PPP upregulation occurs in vivo in organ systems central to heme clearance and that PPP activity correlates with heme levels in mouse sickle cell disease (SCD). Together, our findings demonstrate that metabolic adaptation to heme detoxification in macrophages requires a shift to the PPP that is induced by heme-derived CO, suggesting pharmacologic targeting of macrophage metabolism as a novel therapeutic strategy to improve heme clearance in patients with hemolytic disorders.
Collapse
|
19
|
Iron-rich Kupffer cells exhibit phenotypic changes during the development of liver fibrosis in NASH. iScience 2021; 24:102032. [PMID: 33521599 PMCID: PMC7820131 DOI: 10.1016/j.isci.2020.102032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 12/07/2020] [Accepted: 12/30/2020] [Indexed: 02/06/2023] Open
Abstract
Although recent evidence suggests the involvement of iron accumulation in the pathogenesis of nonalcoholic steatohepatitis (NASH), the underlying mechanisms remain poorly understood. Previously, we reported a unique histological structure termed "crown-like structure (CLS)," where liver-resident macrophages (Kupffer cells) surround dead hepatocytes, scavenge their debris, and induce inflammation and fibrosis in NASH. In this study, using magnetic column separation, we show that iron-rich Kupffer cells exhibit proinflammatory and profibrotic phenotypic changes during the development of NASH, at least partly, through activation of MiT/TFE transcription factors. Activation of MiT/TFE transcription factors is observed in Kupffer cells forming CLSs in murine and human NASH. Iron chelation effectively attenuates liver fibrosis in a murine NASH model. This study provides insight into the pathophysiologic role of iron in NASH. Our data also shed light on a unique macrophage subset rich in iron that contributes to CLS formation and serves as a driver of liver fibrosis.
Collapse
|
20
|
Yook JS, You M, Kim Y, Zhou M, Liu Z, Kim YC, Lee J, Chung S. The thermogenic characteristics of adipocytes are dependent on the regulation of iron homeostasis. J Biol Chem 2021; 296:100452. [PMID: 33631196 PMCID: PMC8010711 DOI: 10.1016/j.jbc.2021.100452] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/09/2021] [Accepted: 02/18/2021] [Indexed: 12/15/2022] Open
Abstract
The development of thermogenic adipocytes concurs with mitochondrial biogenesis, an iron-dependent pathway. Iron regulatory proteins (IRP) 1 and 2 are RNA-binding proteins that regulate intracellular iron homeostasis. IRPs bind to the iron-response element (IRE) of their target mRNAs, balancing iron uptake and deposition at the posttranscriptional levels. However, IRP/IRE-dependent iron regulation in adipocytes is largely unknown. We hypothesized that iron demands are higher in brown/beige adipocytes than white adipocytes to maintain the thermogenic mitochondrial capacity. To test this hypothesis, we investigated the IRP/IRE regulatory system in different depots of adipose tissue. Our results revealed that 1) IRP/IRE interaction was increased in proportional to the thermogenic function of the adipose depot, 2) adipose iron content was increased in adipose tissue browning upon β3-adrenoceptor stimulation, while decreased in thermoneutral conditions, and 3) modulation of iron content was linked with mitochondrial biogenesis. Moreover, the iron requirement was higher in HIB1B brown adipocytes than 3T3-L1 white adipocytes during differentiation. The reduction of the labile iron pool (LIP) suppressed the differentiation of brown/beige adipocytes and mitochondrial biogenesis. Using the 59Fe-Tf, we also demonstrated that thermogenic stimuli triggered cell-autonomous iron uptake and mitochondrial compartmentalization as well as enhanced mitochondrial respiration. Collectively, our work demonstrated that IRP/IRE signaling and subsequent adaptation in iron metabolism are a critical determinant for the thermogenic function of adipocytes.
Collapse
Affiliation(s)
- Jin-Seon Yook
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Mikyoung You
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Yongeun Kim
- Department of Nutrition and Health Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Mi Zhou
- Department of Nutrition and Health Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Zhenhua Liu
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Young-Cheul Kim
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jaekwon Lee
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska, USA
| | - Soonkyu Chung
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA; Department of Nutrition and Health Sciences, University of Nebraska, Lincoln, Nebraska, USA.
| |
Collapse
|
21
|
Abstract
Low-grade chronic adipose tissue (AT) inflammation is now recognized as a pivotal driver of the multi-organ dysfunction associated with obesity-related complications; and adipose tissue macrophages (ATMs) are key to the development of this inflammatory milieu. Along with their role in immunosurveillance, ATMs are central regulators of AT iron homeostasis. Under optimal conditions, ATMs maintain a proper homeostatic balance of iron in adipocytes; however, during obesity, this relationship is altered, and iron is repartitioned into adipocytes as opposed to ATMs. This adipocyte iron overload leads to systemic IR and the mechanism for these effects is still under investigation. Here, we comment on the most recent findings addressing the interplay between adipocyte and ATM iron handling, and metabolic dysfunction.
Collapse
|
22
|
Li Y, Yun K, Mu R. A review on the biology and properties of adipose tissue macrophages involved in adipose tissue physiological and pathophysiological processes. Lipids Health Dis 2020; 19:164. [PMID: 32646451 PMCID: PMC7350193 DOI: 10.1186/s12944-020-01342-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/02/2020] [Indexed: 12/14/2022] Open
Abstract
Obesity exhibits a correlation with metabolic inflammation and endoplasmic reticulum stress, promoting the progression of metabolic disease such as diabetes, hyperlipidemia, hyperuricemia and so on. Adipose tissue macrophages (ATMs) are central players in obesity-associated inflammation and metabolic diseases. Macrophages are involved in lipid and energy metabolism and mitochondrial function in adipocytes. Macrophage polarization is accompanied by metabolic shifting between glycolysis and mitochondrial oxidative phosphorylation. Here, this review focuses on macrophage metabolism linked to functional phenotypes with an emphasis on macrophage polarization in adipose tissue physiological and pathophysiological processes. In particular, the interplay between ATMs and adipocytes in energy metabolism, glycolysis, OXPHOS, iron handing and even interactions with the nervous system have been reviewed. Overall, the understanding of protective and pathogenic roles of ATMs in adipose tissue can potentially provide strategies to prevent and treat obesity-related metabolic disorders.
Collapse
Affiliation(s)
- Yunjia Li
- The First Clinical Medicine Faculty, China Medical University, Shenyang, 110001, China
| | - Ke Yun
- Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, 110001, China
| | - Runqing Mu
- Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, 110001, China.
| |
Collapse
|
23
|
Caslin HL, Bhanot M, Bolus WR, Hasty AH. Adipose tissue macrophages: Unique polarization and bioenergetics in obesity. Immunol Rev 2020; 295:101-113. [PMID: 32237081 DOI: 10.1111/imr.12853] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/25/2020] [Accepted: 02/28/2020] [Indexed: 12/13/2022]
Abstract
Macrophages comprise a majority of the resident immune cells in adipose tissue (AT) and regulate both tissue homeostasis in the lean state and metabolic dysregulation in obesity. Since the AT environment rapidly changes based upon systemic energy status, AT macrophages (ATMs) must adapt phenotypically and metabolically. There is a distinct dichotomy in the polarization and bioenergetics of in vitro models, with M2 macrophages utilizing oxidative phosphorylation (OX PHOS) and M1 macrophages utilizing glycolysis. Early studies suggested differential polarization of ATMs, with M2-like macrophages predominant in lean AT and M1-like macrophages in obese AT. However, recent studies show that the phenotypic plasticity of ATMs is far more complicated, which is also reflected in their bioenergetics. Multiple ATM populations exist along the M2 to M1 continuum and appear to utilize both glycolysis and OX PHOS in obesity. The significance of the dual fuel bioenergetics is unclear and may be related to an intermediate polarization, their buffering capacity, or the result of a mixed population of distinct polarized ATMs. Recent evidence also suggests that ATMs of lean mice serve as a substrate buffer or reservoir to modulate lipid, catecholamine, and iron availability. Furthermore, recent models of weight loss and weight cycling reveal additional roles for ATMs in systemic metabolism. Evaluating ATM phenotype and intracellular metabolism together may more accurately illuminate the consequences of ATM accumulation in obese AT, lending further insight into obesity-related comorbidities in humans.
Collapse
Affiliation(s)
- Heather L Caslin
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Monica Bhanot
- Division of Diabetes, Endocrinology and Metabolism, Vanderbilt Medical Center, Nashville, TN, USA
| | - W Reid Bolus
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Alyssa H Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA.,VA Tennessee Valley Healthcare System, Nashville, TN, USA
| |
Collapse
|
24
|
Winn NC, Volk KM, Hasty AH. Regulation of tissue iron homeostasis: the macrophage "ferrostat". JCI Insight 2020; 5:132964. [PMID: 31996481 DOI: 10.1172/jci.insight.132964] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Iron is an essential element for multiple fundamental biological processes required for life; yet iron overload can be cytotoxic. Consequently, iron concentrations at the cellular and tissue level must be exquisitely governed by mechanisms that complement and fine-tune systemic control. It is well appreciated that macrophages are vital for systemic iron homeostasis, supplying or sequestering iron as needed for erythropoiesis or bacteriostasis, respectively. Indeed, recycling of iron through erythrophagocytosis by splenic macrophages is a major contributor to systemic iron homeostasis. However, accumulating evidence suggests that tissue-resident macrophages regulate local iron availability and modulate the tissue microenvironment, contributing to cellular and tissue function. Here, we summarize the significance of tissue-specific regulation of iron availability and highlight how resident macrophages are critical for this process. This tissue-dependent regulation has broad implications for understanding both resident macrophage function and tissue iron homeostasis in health and disease.
Collapse
Affiliation(s)
- Nathan C Winn
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Katrina M Volk
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Alyssa H Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA
| |
Collapse
|
25
|
Bolus WR, Hasty AH. Contributions of innate type 2 inflammation to adipose function. J Lipid Res 2019; 60:1698-1709. [PMID: 29891508 PMCID: PMC6795076 DOI: 10.1194/jlr.r085993] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/25/2018] [Indexed: 12/17/2022] Open
Abstract
A critical contributor to the health consequences of the obesity epidemic is dysregulated adipose tissue (AT) homeostasis. While white, brown, and beige AT function is altered in obesity-related disease, white AT is marked by progressive inflammation and adipocyte dysfunction and has been the focus of extensive "immunometabolism" research in the past decade. The exact triggering events initiating and sustaining AT inflammation are still under study, but it has been shown that reducing inflammation improves insulin action in AT. Scientific efforts seeking interventions to mitigate obesity-associated AT inflammation continue, and many groups are now determining how lean healthy AT homeostasis is maintained in order to leverage these mechanisms as therapeutic targets. Such studies have revealed that an elaborate network of immune cells, cytokines, and other cellular mediators coordinate AT function. Recent studies elucidated the involvement of the innate immune system in AT homeostasis (e.g., beiging and insulin sensitivity), including M2-like macrophages, eosinophils, innate lymphoid type 2 cells, and several others. In this review, we summarize the existing literature on innate type 2 inflammation in AT; additionally, we draw attention to areas of debate where seemingly conflicting data promises to yield more surprising and elegant biology as studies continue to dissect AT physiology.
Collapse
Affiliation(s)
- W Reid Bolus
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville TN 37232
| | - Alyssa H Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville TN 37232
- Veterans Affairs Tennessee Valley Healthcare System, Nashville TN 37212
| |
Collapse
|
26
|
Caslin HL, Hasty AH. Extrinsic and Intrinsic Immunometabolism Converge: Perspectives on Future Research and Therapeutic Development for Obesity. Curr Obes Rep 2019; 8:210-219. [PMID: 30919312 PMCID: PMC6661206 DOI: 10.1007/s13679-019-00344-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW Research over the past decade has shown that immunologic and metabolic pathways are intricately linked. This burgeoning field of immunometabolism includes intrinsic and extrinsic pathways and is known to be associated with obesity-accelerated metabolic disease. Intrinsic immunometabolism includes the study of fuel utilization and bioenergetic pathways that influence immune cell function. Extrinsic immunometabolism includes the study of immune cells and products that influence systemic metabolism. RECENT FINDINGS Th2 immunity, macrophage iron handling, adaptive immune memory, and epigenetic regulation of immunity, which all require intrinsic metabolic changes, play a role in systemic metabolism and metabolic function, linking the two arms of immunometabolism. Together, this suggests that targeting intrinsic immunometabolism can directly affect immune function and ultimately systemic metabolism. We highlight important questions for future basic research that will help improve translational research and provide therapeutic targets to help establish new treatments for obesity and associated metabolic disorders.
Collapse
Affiliation(s)
- Heather L Caslin
- Molecular Physiology and Biophysics, Vanderbilt University, 813 Light Hall, 23rd Ave. South and Pierce, Nashville, TN, 37232, USA
| | - Alyssa H Hasty
- Molecular Physiology and Biophysics, Vanderbilt University, 813 Light Hall, 23rd Ave. South and Pierce, Nashville, TN, 37232, USA.
- VA Tennessee Valley Healthcare System, Nashville, TN, USA.
| |
Collapse
|