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de Frutos S, Griera M, Hatem-Vaquero M, Campillo S, Gutiérrez-Calabres E, García-Ayuso D, Pardo M, Calleros L, Rodríguez-Puyol M, Rodríguez-Puyol D. The integrin beta1 modulator Tirofiban prevents adipogenesis and obesity by the overexpression of integrin-linked kinase: a pre-clinical approach in vitro and in vivo. Cell Biosci 2022; 12:10. [PMID: 35090553 PMCID: PMC8796419 DOI: 10.1186/s13578-022-00746-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/14/2022] [Indexed: 02/04/2023] Open
Abstract
Background Obesity is caused by the enlargement of the white adipose tissue (WAT) depots, characterized by the hypertrophic enlargement of malfunctioning adipocytes within WAT which increases the storage of triglycerides (TG) in the lipid droplets (LD). Adipogenesis pathways as well as the expression and activity of some extracellular matrix receptors integrins are upregulated. Integrinβ1 (INTB1) is the main isoform involved in WAT remodeling during obesity and insulin resistance-related diseases. We recently described Integrin Linked Kinase (ILK), a scaffold protein recruited by INTB1, as an important mediator of WAT remodeling and insulin resistance. As the few approved drugs to fight obesity have brought long-term cardiovascular side effects and given that the consideration of INTB1 and/or ILK modulation as anti-obesogenic strategies remains unexplored, we aimed to evaluate the anti-obesogenic capacity of the clinically approved anticoagulant Tirofiban (TF), stated in preclinical studies as a cardiovascular protector. Methods Fully differentiated adipocytes originating from C3H10T1/2 were exposed to TF and were co-treated with specific INTB1 blockers or with siRNA-based knockdown ILK expression. Lipid-specific dyes were used to determine the TG content in LD. The genetic expression pattern of ILK, pro-inflammatory cytokines (MCP1, IL6), adipogenesis (PPARγ, Leptin), thermogenesis (UCP1), proliferation (PCNA), lipid metabolism (FASN, HSL, ATGL), and metabolite transporters (FABP4, FAT, AQP7) were detected using quantitative PCR. Cytoskeletal actin polymerization was detected by confocal microscopy. Immunoblotting was performed to detect INTB1 phosphorylation at Thr788/9 and ILK activity as phosphorylation levels of protein kinase B (AKT) in Ser473 and glycogen synthase kinase 3β (GSK3β) at Ser9. TF was intraperitoneally administered once per day to wildtype and ILK knockdown mice (cKDILK) challenged with a high-fat diet (HFD) or control diet (STD) for 2 weeks. Body and WAT weight gains were compared. The expression of ILK and other markers was determined in the visceral epididymal (epi) and inguinal subcutaneous (sc) WAT. Results TF reduced TG content and the expression of adipogenesis markers and transporters in adipocytes, while UCP-1 expression was increased and the expression of lipases, cytokines or PCNA was not affected. Mechanistically, TF rapidly increased and faded the intracellular phosphorylation of INTB1 but not AKT or GSK3β. F-actin levels were rapidly decreased, and INTB1 blockade avoided the TF effect. After 24 h, ILK expression and phosphorylation rates of AKT and GSK3β were upregulated, while ILK silencing increased TG content. INTB1 blockade and ILK silencing avoided TF effects on the TG content and the transcriptional expression of PPARγ and UCP1. In HFD-challenged mice, the systemic administration of TF for several days reduced the weight gain on WAT depots. TF reduced adipogenesis and pro-inflammatory biomarkers and increased lipolysis markers HSL and FAT in epiWAT from HFD, while increased UCP1 in scWAT. In both WATs, TF upregulated ILK expression and activity, while no changes were observed in other tissues. In HFD-fed cKDILK, the blunted ILK in epiWAT worsened weight gain and avoided the anti-obesogenic effect of in vivo TF administration. Conclusions ILK downregulation in WAT can be considered a biomarker of obesity establishment. Via an INTB1-ILK axis, TF restores malfunctioning hypertrophied WAT by changing the expression of adipocyte-related genes, increasing ILK expression and activity, and reducing TG storage. TF prevents obesity, a property to be added to its anticoagulant and cardiovascular protective advantages. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00746-1.
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Moreno Santillán DD, Lama TM, Gutierrez Guerrero YT, Brown AM, Donat P, Zhao H, Rossiter SJ, Yohe LR, Potter JH, Teeling EC, Vernes SC, Davies KTJ, Myers E, Hughes GM, Huang Z, Hoffmann F, Corthals AP, Ray DA, Dávalos LM. Large-scale genome sampling reveals unique immunity and metabolic adaptations in bats. Mol Ecol 2021; 30:6449-6467. [PMID: 34146369 DOI: 10.1111/mec.16027] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 05/27/2021] [Accepted: 06/03/2021] [Indexed: 11/28/2022]
Abstract
Comprising more than 1,400 species, bats possess adaptations unique among mammals including powered flight, unexpected longevity, and extraordinary immunity. Some of the molecular mechanisms underlying these unique adaptations includes DNA repair, metabolism and immunity. However, analyses have been limited to a few divergent lineages, reducing the scope of inferences on gene family evolution across the Order Chiroptera. We conducted an exhaustive comparative genomic study of 37 bat species, one generated in this study, encompassing a large number of lineages, with a particular emphasis on multi-gene family evolution across immune and metabolic genes. In agreement with previous analyses, we found lineage-specific expansions of the APOBEC3 and MHC-I gene families, and loss of the proinflammatory PYHIN gene family. We inferred more than 1,000 gene losses unique to bats, including genes involved in the regulation of inflammasome pathways such as epithelial defence receptors, the natural killer gene complex and the interferon-gamma induced pathway. Gene set enrichment analyses revealed genes lost in bats are involved in defence response against pathogen-associated molecular patterns and damage-associated molecular patterns. Gene family evolution and selection analyses indicate bats have evolved fundamental functional differences compared to other mammals in both innate and adaptive immune system, with the potential to enhance antiviral immune response while dampening inflammatory signalling. In addition, metabolic genes have experienced repeated expansions related to convergent shifts to plant-based diets. Our analyses support the hypothesis that, in tandem with flight, ancestral bats had evolved a unique set of immune adaptations whose functional implications remain to be explored.
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Affiliation(s)
| | - Tanya M Lama
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, USA
| | - Yocelyn T Gutierrez Guerrero
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, Mexico City, Mexico
| | - Alexis M Brown
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, USA
| | - Paul Donat
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, USA
| | - Huabin Zhao
- Department of Ecology, Tibetan Centre for Ecology and Conservation at WHU-TU, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Stephen J Rossiter
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Laurel R Yohe
- Department of Earth & Planetary Science, Yale University, New Haven, Connecticut, USA
| | - Joshua H Potter
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Emma C Teeling
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Sonja C Vernes
- Neurogenetics of Vocal Communication Group, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,School of Biology, The University of St Andrews, Fife, UK
| | - Kalina T J Davies
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Eugene Myers
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Graham M Hughes
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Zixia Huang
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Federico Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, Mississippi, USA
| | - Angelique P Corthals
- Department of Sciences, John Jay College of Criminal Justice, New York, New York, USA
| | - David A Ray
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Liliana M Dávalos
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, USA.,Consortium for Inter- Disciplinary Environmental Research, Stony Brook University, Stony Brook, New York, USA
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Wu WC, Lee WJ, Lee TH, Chen SC, Chen CY. Do different bariatric surgical procedures influence plasma levels of matrix metalloproteinase-2, -7, and -9 among patients with type 2 diabetes mellitus? World J Diabetes 2020; 11:252-260. [PMID: 32547699 PMCID: PMC7284017 DOI: 10.4239/wjd.v11.i6.252] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/09/2020] [Accepted: 04/24/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bariatric surgery is an efficient strategy for body weight and type 2 diabetes mellitus (T2DM) management. Abnormal lipid deposition in visceral organs, especially the pancreas and liver, might cause beta-cell dysfunction and insulin resistance. Extracellular matrix (ECM) remodeling allows adipose expansion, and matrix metalloproteinases (MMPs) play essential roles in ECM construction. MMP-2 and MMP-9 are the substrates of MMP-7. Different studies have reported that MMP-2, -7, and -9 increase in patients with obesity and metabolic syndromes or T2DM and are considered biomarkers in obesity and hyperglycemia patients. AIM To prospectively investigate whether MMP-2, MMP-7, and MMP-9 differ after two bariatric surgeries: Gastric bypass (GB) and sleeve gastrectomy (SG). METHODS We performed GB in 23 and SG in 19 obese patients with T2DM. We measured body weight, waist circumference, body mass index (BMI), and serum concentrations of total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting blood sugar (FBS), hemoglobin A1c (HbA1c), C-peptide, homeostasis model assessments of insulin resistance, and MMP-2, MMP-7, and MMP-9 levels at baseline and at 3, 12, and 24 mo post-operation. RESULTS Twenty-three patients aged 44.7 ± 9.7 years underwent GB, and 19 patients aged 40.1 ± 9.1 years underwent SG. In the GB group, BMI decreased from 30.3 ± 3.4 to 24.4 ± 2.4 kg/m2, HbA1c decreased from 9.2% ± 1.5% to 6.7% ± 1.4%, and FBS decreased from 171.6 ± 65.0 mg/dL to 117.7 ± 37.5 mg/dL 2 years post-operation (P < 0.001). However, the MMP-2, MMP-7, and MMP-9 levels pre- and post-GB were similar even 2 years post-operation (P = 0.107, 0.258, and 0.466, respectively). The SG group revealed similar results: BMI decreased from 36.2 ± 5.1 to 26.9 ± 4.7 kg/m2, HbA1c decreased from 7.9% ± 1.7% to 5.8% ± 0.6%, and FBS decreased from 138.3 ± 55.6 mg/dL to 95.1 ± 3.1 mg/dL (P < 0.001). The serum MMP-2, -7, and -9 levels pre- and post-SG were not different (P = 0.083, 0.869, and 0.1, respectively). CONCLUSION Improvements in obesity and T2DM induced by bariatric surgery might be the result of MMP-2, -7, or -9 independent pathways.
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Affiliation(s)
- Wen-Chi Wu
- Department of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Wei-Jei Lee
- Department of Surgery, Min-Sheng General Hospital, Taoyuan 330, Taiwan
- Taiwan Society for Metabolic and Bariatric Surgery, Taipei 11031, Taiwan
| | - Tzong-His Lee
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan
| | - Shu-Chun Chen
- Department of Nursing, Chang-Gung Institute of Technology, Guishan, Taoyuan 333, Taiwan
| | - Chih-Yen Chen
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Faculty of Medicine and Institute of Emergency and Critical Medicine, National Yang-Ming University School of Medicine, Taipei 11221, Taiwan
- Association for the Study of Small Intestinal Diseases, Guishan, Taoyuan 33305, Taiwan
- Chinese Taipei Society for the Study of Obesity, Taipei 110, Taiwan
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Implications of Skeletal Muscle Extracellular Matrix Remodeling in Metabolic Disorders: Diabetes Perspective. Int J Mol Sci 2020; 21:ijms21113845. [PMID: 32481704 PMCID: PMC7312063 DOI: 10.3390/ijms21113845] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/23/2020] [Accepted: 05/25/2020] [Indexed: 12/13/2022] Open
Abstract
The extracellular matrix (ECM) provides a scaffold for cells, controlling biological processes and providing structural as well as mechanical support to surrounding cells. Disruption of ECM homeostasis results in several pathological conditions. Skeletal muscle ECM is a complex network comprising collagens, proteoglycans, glycoproteins, and elastin. Recent therapeutic approaches targeting ECM remodeling have been extensively deliberated. Various ECM components are typically found to be augmented in the skeletal muscle of obese and/or diabetic humans. Skeletal muscle ECM remodeling is thought to be a feature of the pathogenic milieu allied with metabolic dysregulation, obesity, and eventual diabetes. This narrative review explores the current understanding of key components of skeletal muscle ECM and their specific roles in the regulation of metabolic diseases. Additionally, we discuss muscle-specific integrins and their role in the regulation of insulin sensitivity. A better understanding of the importance of skeletal muscle ECM remodeling, integrin signaling, and other factors that regulate insulin activity may help in the development of novel therapeutics for managing diabetes and other metabolic disorders.
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Bednarczyk M, Stege H, Grabbe S, Bros M. β2 Integrins-Multi-Functional Leukocyte Receptors in Health and Disease. Int J Mol Sci 2020; 21:E1402. [PMID: 32092981 PMCID: PMC7073085 DOI: 10.3390/ijms21041402] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 12/25/2022] Open
Abstract
β2 integrins are heterodimeric surface receptors composed of a variable α (CD11a-CD11d) and a constant β (CD18) subunit and are specifically expressed by leukocytes. The α subunit defines the individual functional properties of the corresponding β2 integrin, but all β2 integrins show functional overlap. They mediate adhesion to other cells and to components of the extracellular matrix (ECM), orchestrate uptake of extracellular material like complement-opsonized pathogens, control cytoskeletal organization, and modulate cell signaling. This review aims to delineate the tremendous role of β2 integrins for immune functions as exemplified by the phenotype of LAD-I (leukocyte adhesion deficiency 1) patients that suffer from strong recurrent infections. These immune defects have been largely attributed to impaired migratory and phagocytic properties of polymorphonuclear granulocytes. The molecular base for this inherited disease is a functional impairment of β2 integrins due to mutations within the CD18 gene. LAD-I patients are also predisposed for autoimmune diseases. In agreement, polymorphisms within the CD11b gene have been associated with autoimmunity. Consequently, β2 integrins have received growing interest as targets in the treatment of autoimmune diseases. Moreover, β2 integrin activity on leukocytes has been implicated in tumor development.
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Affiliation(s)
| | | | | | - Matthias Bros
- Department of Dermatology, University Medical Center Mainz, Langenbeckstraße 1, 55131 Mainz, Germany; (M.B.); (H.S.); (S.G.)
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Ruiz-Ojeda FJ, Méndez-Gutiérrez A, Aguilera CM, Plaza-Díaz J. Extracellular Matrix Remodeling of Adipose Tissue in Obesity and Metabolic Diseases. Int J Mol Sci 2019; 20:ijms20194888. [PMID: 31581657 PMCID: PMC6801592 DOI: 10.3390/ijms20194888] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 09/25/2019] [Accepted: 09/29/2019] [Indexed: 12/15/2022] Open
Abstract
The extracellular matrix (ECM) is a network of different proteins and proteoglycans that controls differentiation, migration, repair, survival, and development, and it seems that its remodeling is required for healthy adipose tissue expansion. Obesity drives an excessive lipid accumulation in adipocytes, which provokes immune cells infiltration, fibrosis (an excess of deposition of ECM components such as collagens, elastin, and fibronectin) and inflammation, considered a consequence of local hypoxia, and ultimately insulin resistance. To understand the mechanism of this process is a challenge to treat the metabolic diseases. This review is focused at identifying the putative role of ECM in adipose tissue, describing its structure and components, its main tissue receptors, and how it is affected in obesity, and subsequently the importance of an appropriate ECM remodeling in adipose tissue expansion to prevent metabolic diseases.
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Affiliation(s)
- Francisco Javier Ruiz-Ojeda
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, 18071 Granada, Spain.
- Instituto de Investigación Biosanitaria IBS.GRANADA, Complejo Hospitalario Universitario de Granada, 18014 Granada, Spain.
- RG Adipocytes and metabolism, Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Center Munich, 85764 Neuherberg, Munich, Germany.
| | - Andrea Méndez-Gutiérrez
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, 18071 Granada, Spain.
- Instituto de Investigación Biosanitaria IBS.GRANADA, Complejo Hospitalario Universitario de Granada, 18014 Granada, Spain.
- Institute of Nutrition and Food Technology "José Mataix", Center of Biomedical Research, University of Granada, Avda. del Conocimiento s/n. 18016 Armilla, Granada, Spain.
- CIBEROBN (CIBER Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain.
| | - Concepción María Aguilera
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, 18071 Granada, Spain.
- Instituto de Investigación Biosanitaria IBS.GRANADA, Complejo Hospitalario Universitario de Granada, 18014 Granada, Spain.
- Institute of Nutrition and Food Technology "José Mataix", Center of Biomedical Research, University of Granada, Avda. del Conocimiento s/n. 18016 Armilla, Granada, Spain.
- CIBEROBN (CIBER Physiopathology of Obesity and Nutrition), Instituto de Salud Carlos III, 28029 Madrid, Spain.
| | - Julio Plaza-Díaz
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, 18071 Granada, Spain.
- Instituto de Investigación Biosanitaria IBS.GRANADA, Complejo Hospitalario Universitario de Granada, 18014 Granada, Spain.
- Institute of Nutrition and Food Technology "José Mataix", Center of Biomedical Research, University of Granada, Avda. del Conocimiento s/n. 18016 Armilla, Granada, Spain.
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Fagerholm SC, Guenther C, Llort Asens M, Savinko T, Uotila LM. Beta2-Integrins and Interacting Proteins in Leukocyte Trafficking, Immune Suppression, and Immunodeficiency Disease. Front Immunol 2019; 10:254. [PMID: 30837997 PMCID: PMC6389632 DOI: 10.3389/fimmu.2019.00254] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/29/2019] [Indexed: 12/21/2022] Open
Abstract
Beta2-integrins are complex leukocyte-specific adhesion molecules that are essential for leukocyte (e.g., neutrophil, lymphocyte) trafficking, as well as for other immunological processes such as neutrophil phagocytosis and ROS production, and T cell activation. Intriguingly, however, they have also been found to negatively regulate cytokine responses, maturation, and migratory responses in myeloid cells such as macrophages and dendritic cells, revealing new, and unexpected roles of these molecules in immunity. Because of their essential role in leukocyte function, a lack of expression or function of beta2-integrins causes rare immunodeficiency syndromes, Leukocyte adhesion deficiency type I, and type III (LAD-I and LAD-III). LAD-I is caused by reduced or lost expression of beta2-integrins, whilst in LAD-III, beta2-integrins are expressed but dysfunctional because a major integrin cytoplasmic regulator, kindlin-3, is mutated. Interestingly, some LAD-related phenotypes such as periodontitis have recently been shown to be due to an uncontrolled inflammatory response rather than to an uncontrolled infection, as was previously thought. This review will focus on the recent advances concerning the regulation and functions of beta2-integrins in leukocyte trafficking, immune suppression, and immune deficiency disease.
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Affiliation(s)
- Susanna C Fagerholm
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Carla Guenther
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Marc Llort Asens
- Molecular and Integrative Biosciences Research Program, Faculty of Bio- and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | | | - Liisa M Uotila
- Research Services, University of Helsinki, Helsinki, Finland
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Burhans MS, Hagman DK, Kuzma JN, Schmidt KA, Kratz M. Contribution of Adipose Tissue Inflammation to the Development of Type 2 Diabetes Mellitus. Compr Physiol 2018; 9:1-58. [PMID: 30549014 DOI: 10.1002/cphy.c170040] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The objective of this comprehensive review is to summarize and discuss the available evidence of how adipose tissue inflammation affects insulin sensitivity and glucose tolerance. Low-grade, chronic adipose tissue inflammation is characterized by infiltration of macrophages and other immune cell populations into adipose tissue, and a shift toward more proinflammatory subtypes of leukocytes. The infiltration of proinflammatory cells in adipose tissue is associated with an increased production of key chemokines such as C-C motif chemokine ligand 2, proinflammatory cytokines including tumor necrosis factor α and interleukins 1β and 6 as well as reduced expression of the key insulin-sensitizing adipokine, adiponectin. In both rodent models and humans, adipose tissue inflammation is consistently associated with excess fat mass and insulin resistance. In humans, associations with insulin resistance are stronger and more consistent for inflammation in visceral as opposed to subcutaneous fat. Further, genetic alterations in mouse models of obesity that reduce adipose tissue inflammation are-almost without exception-associated with improved insulin sensitivity. However, a dissociation between adipose tissue inflammation and insulin resistance can be observed in very few rodent models of obesity as well as in humans following bariatric surgery- or low-calorie-diet-induced weight loss, illustrating that the etiology of insulin resistance is multifactorial. Taken together, adipose tissue inflammation is a key factor in the development of insulin resistance and type 2 diabetes in obesity, along with other factors that likely include inflammation and fat accumulation in other metabolically active tissues. © 2019 American Physiological Society. Compr Physiol 9:1-58, 2019.
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Affiliation(s)
- Maggie S Burhans
- Cancer Prevention Program, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.,Department of Epidemiology, University of Washington, Seattle, Washington, USA
| | - Derek K Hagman
- Cancer Prevention Program, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Jessica N Kuzma
- Cancer Prevention Program, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Kelsey A Schmidt
- Cancer Prevention Program, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.,Department of Epidemiology, University of Washington, Seattle, Washington, USA
| | - Mario Kratz
- Cancer Prevention Program, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.,Department of Epidemiology, University of Washington, Seattle, Washington, USA.,Department of Medicine, University of Washington, Seattle, Washington, USA
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Abstract
At the simplest level, obesity is the manifestation of an imbalance between caloric intake and expenditure; however, the pathophysiological mechanisms that govern the development of obesity and associated complications are enormously complex. Fibrosis within the adipose tissue compartment is one such factor that may influence the development of obesity and/or obesity-related comorbidities. Furthermore, the functional consequences of adipose tissue fibrosis are a matter of considerable debate, with evidence that fibrosis serves both adaptive and maladaptive roles. Tissue fibrosis itself is incompletely understood, and multiple cellular and molecular pathways are involved in the development, maintenance, and resolution of the fibrotic state. Within the context of obesity, fibrosis influences molecular and cellular events that relate to adipocytes, inflammatory cells, inflammatory mediators, and supporting adipose stromal tissue. In this Review, we explore what is known about the interplay between the development of adipose tissue fibrosis and obesity, with a view toward future investigative and therapeutic avenues.
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Affiliation(s)
| | - Michael J Podolsky
- Cardiovascular Research Institute.,Lung Biology Center, and.,Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Kamran Atabai
- Cardiovascular Research Institute.,Lung Biology Center, and.,Department of Medicine, University of California, San Francisco, San Francisco, California, USA
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Uotila LM, Guenther C, Savinko T, Lehti TA, Fagerholm SC. Filamin A Regulates Neutrophil Adhesion, Production of Reactive Oxygen Species, and Neutrophil Extracellular Trap Release. THE JOURNAL OF IMMUNOLOGY 2017; 199:3644-3653. [PMID: 28986439 DOI: 10.4049/jimmunol.1700087] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 09/11/2017] [Indexed: 12/26/2022]
Abstract
Neutrophils are of fundamental importance in the early immune response and use various mechanisms to neutralize invading pathogens. They kill endocytosed pathogens by releasing reactive oxygen species in the phagosome and release neutrophil extracellular traps (NETs) into their surroundings to immobilize and kill invading micro-organisms. Filamin A (FlnA) is an important actin cross-linking protein that is required for cellular processes involving actin rearrangements, such cell migration. It has also been shown to negatively regulate integrin activation and adhesion. However, its role in the regulation of β2 integrin-dependent adhesion, as well as in other cellular functions in neutrophils, is poorly understood. Using a transgenic mouse model in which FlnA is selectively depleted in myeloid cells, such as neutrophils, we show that FlnA negatively regulates β2 integrin adhesion to complement component iC3b and ICAM-1 in shear-free, but not shear-flow, conditions. FlnA deletion does not affect phagocytosis of Escherichia coli or Staphylococcus aureus or their intracellular killing. However, FlnA negatively regulates production of reactive oxygen species upon cell activation. Conversely, neutrophil activation through TLR4, as well as through activation by the Gram-negative bacteria E. coli, results in reduced NET production in FlnA-depleted neutrophils. Thus, FlnA is a negative regulator of β2 integrin-dependent cell adhesion and reactive oxygen species production but is required for NET production in primary murine neutrophils.
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Affiliation(s)
- Liisa M Uotila
- Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland; and
| | - Carla Guenther
- Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland; and
| | - Terhi Savinko
- Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland; and
| | - Timo A Lehti
- Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland; and
| | - Susanna C Fagerholm
- Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland; and .,Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
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Abstract
Adipose tissue has traditionally been defined as connective tissue that stores excess calories in the form of triacylglycerol. However, the physiologic functions attributed to adipose tissue are expanding, and it is now well established that adipose tissue is an endocrine gland. Among the endocrine factors elaborated by adipose tissue are the adipokines; hormones, similar in structure to cytokines, produced by adipose tissue in response to changes in adipocyte triacylglycerol storage and local and systemic inflammation. They inform the host regarding long-term energy storage and have a profound influence on reproductive function, blood pressure regulation, energy homeostasis, the immune response, and many other physiologic processes. The adipokines possess pro- and anti-inflammatory properties and play a critical role in integrating systemic metabolism with immune function. In calorie restriction and starvation, proinflammatory adipokines decline and anti-inflammatory adipokines increase, which informs the host of energy deficits and contributes to the suppression of immune function. In individuals with normal metabolic status, there is a balance of pro- and anti-inflammatory adipokines. This balance shifts to favor proinflammatory mediators as adipose tissue expands during the development of obesity. As a consequence, the proinflammatory status of adipose tissue contributes to a chronic low-grade state of inflammation and metabolic disorders associated with obesity. These disturbances are associated with an increased risk of metabolic disease, type 2 diabetes, cardiovascular disease, and many other pathological conditions. This review focuses on the impact of energy homeostasis on the adipokines in immune function.
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Affiliation(s)
- Peter Mancuso
- Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA
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12
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Lin D, Chun TH, Kang L. Adipose extracellular matrix remodelling in obesity and insulin resistance. Biochem Pharmacol 2016; 119:8-16. [PMID: 27179976 DOI: 10.1016/j.bcp.2016.05.005] [Citation(s) in RCA: 144] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 05/10/2016] [Indexed: 12/15/2022]
Abstract
The extracellular matrix (ECM) of adipose tissues undergoes constant remodelling to allow adipocytes and their precursor cells to change cell shape and function in adaptation to nutritional cues. Abnormal accumulation of ECM components and their modifiers in adipose tissues has been recently demonstrated to cause obesity-associated insulin resistance, a hallmark of type 2 diabetes. Integrins and other ECM receptors (e.g. CD44) that are expressed in adipose tissues have been shown to regulate insulin sensitivity. It is well understood that a hypoxic response is observed in adipose tissue expansion during obesity progression and that hypoxic response accelerates fibrosis and inflammation in white adipose tissues. The expansion of adipose tissues should require angiogenesis; however, the excess deposition of ECM limits the angiogenic response of white adipose tissues in obesity. While recent studies have focused on the metabolic consequences and the mechanisms of adipose tissue expansion and remodelling, little attention has been paid to the role played by the interaction between peri-adipocyte ECM and their cognate cell surface receptors. This review will address what is currently known about the roles played by adipose ECM, their modifiers, and ECM receptors in obesity and insulin resistance. Understanding how excess ECM deposition in the adipose tissue deteriorates insulin sensitivity would provide us hints to develop a new therapeutic strategy for the treatment of insulin resistance and type 2 diabetes.
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Affiliation(s)
- De Lin
- Division of Cancer Research, School of Medicine, University of Dundee, Dundee, UK
| | - Tae-Hwa Chun
- Division of Metabolism, Endocrinology & Diabetes (MEND), Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Li Kang
- Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, UK.
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