1
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Rasheed A, Rayner KJ. Macrophage Responses to Environmental Stimuli During Homeostasis and Disease. Endocr Rev 2021; 42:407-435. [PMID: 33523133 PMCID: PMC8284619 DOI: 10.1210/endrev/bnab004] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Indexed: 12/20/2022]
Abstract
Work over the last 40 years has described macrophages as a heterogeneous population that serve as the frontline surveyors of tissue immunity. As a class, macrophages are found in almost every tissue in the body and as distinct populations within discrete microenvironments in any given tissue. During homeostasis, macrophages protect these tissues by clearing invading foreign bodies and/or mounting immune responses. In addition to varying identities regulated by transcriptional programs shaped by their respective environments, macrophage metabolism serves as an additional regulator to temper responses to extracellular stimuli. The area of research known as "immunometabolism" has been established within the last decade, owing to an increase in studies focusing on the crosstalk between altered metabolism and the regulation of cellular immune processes. From this research, macrophages have emerged as a prime focus of immunometabolic studies, although macrophage metabolism and their immune responses have been studied for centuries. During disease, the metabolic profile of the tissue and/or systemic regulators, such as endocrine factors, become increasingly dysregulated. Owing to these changes, macrophage responses can become skewed to promote further pathophysiologic changes. For instance, during diabetes, obesity, and atherosclerosis, macrophages favor a proinflammatory phenotype; whereas in the tumor microenvironment, macrophages elicit an anti-inflammatory response to enhance tumor growth. Herein we have described how macrophages respond to extracellular cues including inflammatory stimuli, nutrient availability, and endocrine factors that occur during and further promote disease progression.
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Affiliation(s)
- Adil Rasheed
- University of Ottawa Heart Institute, Ottawa, Ontario, Canada.,Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Katey J Rayner
- University of Ottawa Heart Institute, Ottawa, Ontario, Canada.,Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.,Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
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2
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Sharif O, Brunner JS, Vogel A, Schabbauer G. Macrophage Rewiring by Nutrient Associated PI3K Dependent Pathways. Front Immunol 2019; 10:2002. [PMID: 31497027 PMCID: PMC6712174 DOI: 10.3389/fimmu.2019.02002] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 08/07/2019] [Indexed: 12/15/2022] Open
Abstract
Class 1 Phosphoinositide-3-Kinases (PI3Ks) have been widely studied and mediate essential roles in cellular proliferation, chemotaxis, insulin sensitivity, and immunity. Here, we provide a comprehensive overview of how macrophage expressed PI3Ks and their downstream pathways orchestrate responses to metabolic stimuli and nutrients, polarizing macrophages, shaping their cellular identity and function. Particular emphasis will be given to adipose tissue macrophages, crucial players of insulin resistance and chronic metabolically triggered inflammation during obesity. An understanding of PI3K dependent wiring of macrophage responses is important as this is involved in various diseases ranging from obesity, type 2 diabetes to chronic inflammatory disease.
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Affiliation(s)
- Omar Sharif
- Centre for Physiology and Pharmacology, Institute for Vascular Biology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Julia Stefanie Brunner
- Centre for Physiology and Pharmacology, Institute for Vascular Biology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Andrea Vogel
- Centre for Physiology and Pharmacology, Institute for Vascular Biology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Gernot Schabbauer
- Centre for Physiology and Pharmacology, Institute for Vascular Biology, Medical University Vienna, Vienna, Austria
- Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
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3
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Interleukin-4 Boosts Insulin-Induced Energy Deposits by Enhancing Glucose Uptake and Lipogenesis in Hepatocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:6923187. [PMID: 30584465 PMCID: PMC6280305 DOI: 10.1155/2018/6923187] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 08/14/2018] [Accepted: 09/06/2018] [Indexed: 12/20/2022]
Abstract
Type 2 diabetes mellitus (T2DM), with dysregulated hepatic gluconeogenesis as the major cause of fasting hyperglycemia, is closely associated with chronic inflammation. We previously demonstrated interleukin-4 (IL-4) improves insulin sensitivity and glucose tolerance while reducing lipid deposits. The present study examined the in vitro effects of IL-4 on insulin signaling molecules, glucose uptake, and lipid metabolism in hepatocytes, as well as in vivo effects on hepatic adiposity, for elucidating the roles of IL-4 in hepatic energy metabolism. Potential interaction between IL-4 and insulin in regulating hepatic metabolism was also investigated. Our results showed that IL-4 enhanced Akt and GSK-3α/β phosphorylations, which in turn promoted glycogen synthesis. IL-4 not only potentiated basal glucose uptake by upregulating glucose transporter 2 expression but also promoted insulin-induced glucose uptake. Additionally, IL-4 increased triglyceride contents through facilitating free fatty acid uptake and expression/activity of lipogenic enzymes. The major effects of IL-4 on the liver were to promote energy storage by boosting insulin-stimulated glucose uptake and lipid synthesis. This study provides evidence to implicate the novel roles of IL-4 in mediating hepatic glucose and lipid metabolism, interactions between immune responses and metabolic homeostasis, and the involvement of IL-4 in metabolic abnormalities.
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4
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Novita BD, Soediono EI, Nugraha J. Metformin associated inflammation levels regulation in type 2 diabetes mellitus-tuberculosis coinfection patients – A case report. ACTA ACUST UNITED AC 2018; 65:345-349. [DOI: 10.1016/j.ijtb.2018.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 08/31/2018] [Indexed: 01/27/2023]
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5
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Perkisas S, Vandewoude M. Where frailty meets diabetes. Diabetes Metab Res Rev 2016; 32 Suppl 1:261-7. [PMID: 26453435 DOI: 10.1002/dmrr.2743] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/13/2015] [Accepted: 10/06/2015] [Indexed: 12/11/2022]
Abstract
Diabetes is a chronic illness that has an effect on multiple organ systems. Frailty is a state of increased vulnerability to stressors and a limited capacity to maintain homeostasis. It is a multidimensional concept and a dynamic condition that can improve or worsen over time. Frailty is either physical or psychological or a combination of these two components. Sarcopenia, which is the age-related loss of skeletal muscle mass and strength, is the main attributor to the physical form of frailty. Although the pathophysiology of diabetes is commonly focused on impaired insulin secretion, overload of gluconeogenesis and insulin resistance, newer insights broaden this etiologic horizon. Immunologic factors that create a chronic state of low-grade inflammation--'inflammaging'--have an influence on both the ageing process and diabetes. Persons with diabetes mellitus already tend to have an accelerated ageing process that places them at greater risk for developing frailty at an earlier age. The development of frailty--and sarcopenia--is multifactorial and includes nutritional, physical and hormonal elements; these elements are interlinked with those of diabetes. A lower muscle mass will lead to poorer glycaemic control through lower muscle glucose uptake. This leads to higher insulin secretion and insulin resistance, which is the stepping stone for diabetes itself.
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Affiliation(s)
- Stany Perkisas
- Department of Geriatrics, University of Antwerp, Antwerp, Belgium
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6
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Rajwani A, Cubbon RM, Wheatcroft SB. Cell-specific insulin resistance: implications for atherosclerosis. Diabetes Metab Res Rev 2012; 28:627-34. [PMID: 22987644 DOI: 10.1002/dmrr.2336] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Insulin resistance is increasingly acknowledged as an independent risk factor for cardiovascular disease. Despite this, our understanding of the cellular and molecular mechanisms that might account for this relationship remain incompletely understood. A key challenge has been in distinguishing between a 'whole-body' milieu of inflammation and oxidative stress from the ramifications of cell-specific resistance to insulin. Transgenic models have now begun to explore the cellular influences of insulin resistance on vascular biology, with novel implications for atherosclerosis across a range of cells including endothelial cells, endothelial progenitor cells, vascular smooth muscle cells, macrophages and fibroblasts. Emerging data from these models have also begun to challenge conventional dogma. In particular, the findings across various cell types are disparate with some even implying a protective influence on vascular biology. We now review these data, highlighting recent advances in our understanding of cellular resistance to insulin as well as those areas where there remains a paucity of data.
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Affiliation(s)
- A Rajwani
- Division of Cardiovascular & Diabetes Research, Leeds Institute of Genetics, Heath & Therapeutics and the Multidisciplinary Cardiovascular Research Centre, University of Leeds, United Kingdom
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7
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Abstract
Macrophages are key innate immune effector cells best known for their role as professional phagocytes, which also include neutrophils and dendritic cells. Recent evidence indicates that macrophages are also key players in metabolic homoeostasis. Macrophages can be found in many tissues, where they respond to metabolic cues and produce pro- and/or anti-inflammatory mediators to modulate metabolite programmes. Certain metabolites, such as fatty acids, ceramides and cholesterol crystals, elicit inflammatory responses through pathogen-sensing signalling pathways, implicating a maladaptation of macrophages and the innate immune system to elevated metabolic stress associated with overnutrition in modern societies. The outcome of this maladaptation is a feedforward inflammatory response leading to a state of unresolved inflammation and a collection of metabolic pathologies, including insulin resistance, fatty liver, atherosclerosis and dyslipidaemia. The present review summarizes what is known about the contributions of macrophages to metabolic diseases and the signalling pathways that are involved in metabolic stress-induced macrophage activation. Understanding the role of macrophages in these processes will help us to develop therapies against detrimental effects of the metabolic syndrome.
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8
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Xu JM, Shi GP. Emerging role of mast cells and macrophages in cardiovascular and metabolic diseases. Endocr Rev 2012; 33:71-108. [PMID: 22240242 PMCID: PMC3365842 DOI: 10.1210/er.2011-0013] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 09/12/2011] [Indexed: 12/11/2022]
Abstract
Mast cells are essential in allergic immune responses. Recent discoveries have revealed their direct participation in cardiovascular diseases and metabolic disorders. Although more sophisticated mechanisms are still unknown, data from animal studies suggest that mast cells act similarly to macrophages and other inflammatory cells and contribute to human diseases through cell-cell interactions and the release of proinflammatory cytokines, chemokines, and proteases to induce inflammatory cell recruitment, cell apoptosis, angiogenesis, and matrix protein remodeling. Reduced cardiovascular complications and improved metabolic symptoms in animals receiving over-the-counter antiallergy medications that stabilize mast cells open another era of mast cell biology and bring new hope to human patients suffering from these conditions.
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Affiliation(s)
- Jia-Ming Xu
- Department of Medicine, Nanfang Hospital and Southern Medical University, Guangzhou 510515, China
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9
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Cardellini M, Menghini R, Luzi A, Davato F, Cardolini I, D'Alfonso R, Gentileschi P, Rizza S, Marini MA, Porzio O, Lauro D, Sbraccia P, Lauro R, Federici M. Decreased IRS2 and TIMP3 expression in monocytes from offspring of type 2 diabetic patients is correlated with insulin resistance and increased intima-media thickness. Diabetes 2011; 60:3265-70. [PMID: 21984580 PMCID: PMC3219931 DOI: 10.2337/db11-0162] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE In humans, it is unclear if insulin resistance at the monocyte level is associated with atherosclerosis in vivo. Here we have studied first-degree relatives of patients with type 2 diabetes to investigate whether a reduction in components of the insulin signal transduction pathways, such as the insulin receptor (InsR) or InsR substrate 1 or 2 (IRS1 or IRS2), or a reduction in genetic modifiers of insulin action, such as the TIMP3/ADAM17 (tissue inhibitor of metalloproteinase 3/A disintegrin and metalloprotease domain 17) pathway, is associated with evidence of atherosclerosis. RESEARCH DESIGN AND METHODS Insulin sensitivity was analyzed through euglycemic-hyperinsulinemic clamp, and subclinical atherosclerosis was analyzed through intimal medial thickness. Monocytes were isolated through magnetic cell sorting, and mRNA and proteins were extracted and analyzed by quantitative PCR and pathscan enzyme-linked immunosorbent assays, respectively. RESULTS In monocyte cells from human subjects with increased risk for diabetes and atherosclerosis, we found that gene expression, protein levels, and tyrosine phosphorylation of IRS2, but not InsR or IRS1, were decreased. TIMP3 was also reduced, along with insulin resistance, resulting in increased ectodomain shedding activity of the metalloprotease ADAM17. CONCLUSIONS Systemic insulin resistance and subclinical atherosclerosis are associated with decreased IRS2 and TIMP3 expression in circulating monocytes.
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Affiliation(s)
- Marina Cardellini
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Rossella Menghini
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Alessio Luzi
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Francesca Davato
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Iris Cardolini
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Rossella D'Alfonso
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Paolo Gentileschi
- Department of Surgical Sciences, University of Rome Tor Vergata, Rome, Italy
| | - Stefano Rizza
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | | | - Ottavia Porzio
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Davide Lauro
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Paolo Sbraccia
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Renato Lauro
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Massimo Federici
- Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
- Corresponding author: Massimo Federici,
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10
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Go MJ, Min HS, Lee JY, Kim SS, Kim YJ. Association of an Anti-inflammatory Cytokine Gene IL4 Polymorphism with the Risk of Type 2 Diabetes Mellitus in Korean Populations. Genomics Inform 2011. [DOI: 10.5808/gi.2011.9.3.114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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11
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Mao F, Chen T, Zhao Y, Zhang C, Bai B, Zhao S, Xu Z, Shi C. Insulin resistance: a potential marker and risk factor for active tuberculosis? Med Hypotheses 2011; 77:66-8. [PMID: 21459520 DOI: 10.1016/j.mehy.2011.03.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 03/01/2011] [Accepted: 03/12/2011] [Indexed: 12/12/2022]
Abstract
Current tuberculosis control measures are focused on the prompt detection and treatment of active tuberculosis. Despite the measured success of this strategy, tuberculosis continues to be a public health issue of major significance around the world. This unwanted situation suggests the need to expand our control efforts by exploring specific markers for the disease. Insulin resistance is one such marker. Although insulin resistance has been implicated in various diseases, thus far, no attempt has been made to analyze what has proved to be a direct relationship between insulin resistance and Mycobacterium tuberculosis susceptibility. Several studies have shown the role of insulin not only in cellular metabolism but also, more importantly, in phagocytosis of M. tuberculosis. Therefore, we hypothesize that insulin resistance can be considered a potential risk factor for active M. tuberculosis infection.
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Affiliation(s)
- Fengfeng Mao
- Laboratory Animal Center, The Fourth Military Medical University, 17 Changlexilu, Xi'an 710032, PR China.
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12
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Mima A, Ohshiro Y, Kitada M, Matsumoto M, Geraldes P, Li C, Li Q, White GS, Cahill C, Rask-Madsen C, King GL. Glomerular-specific protein kinase C-β-induced insulin receptor substrate-1 dysfunction and insulin resistance in rat models of diabetes and obesity. Kidney Int 2011; 79:883-96. [PMID: 21228767 DOI: 10.1038/ki.2010.526] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Insulin resistance has been associated with the progression of chronic kidney disease in both diabetes and obesity. In order to determine the cellular mechanisms contributing to this, we characterized insulin signaling in renal tubules and glomeruli during diabetic and insulin-resistant states using streptozotocin-diabetic and Zucker fatty-insulin-resistant rats. Compared with nondiabetic and Zucker lean rats, the insulin-induced phosphorylation of insulin receptor substrate-1 (IRS1), Akt, endothelial nitric oxide synthase, and glycogen synthase kinase 3α were selectively inhibited in the glomeruli but not in the renal tubules of both respective models. Protein, but not mRNA levels of IRS1, was decreased only in the glomeruli of streptozotocin-diabetic rats likely due to increased ubiquitination. Treatment with the protein kinase C-β inhibitor, ruboxistaurin, enhanced insulin actions and elevated IRS1 expression. In glomerular endothelial cells, high glucose inhibited the phosphorylation of Akt, endothelial nitric oxide synthase, and glycogen synthase kinase 3α; decreased IRS1 protein expression and increased its association with ubiquitin. Overexpression of IRS1 or the addition of ruboxistaurin reversed the inhibitory effects of high glucose. Thus, loss of insulin's effect on endothelial nitric oxide synthase and glycogen synthase kinase 3α activation may contribute to the glomerulopathy observed in diabetes and obesity.
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Affiliation(s)
- Akira Mima
- Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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13
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Tauroursodeoxycholic acid attenuates lipid accumulation in endoplasmic reticulum-stressed macrophages. J Cardiovasc Pharmacol 2010; 55:49-55. [PMID: 19834331 DOI: 10.1097/fjc.0b013e3181c37d86] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND/AIM Recent evidence suggests that endoplasmic reticulum (ER) stress provoked under diabetic conditions augments the expression of scavenger receptors on macrophages, promoting the uptake of oxidized low-density lipoprotein uptake and atherogenesis. The aim of the present study was to test the hypothesis that the chemical chaperone tauroursodeoxycholic acid (TUDCA) attenuates lipid accumulation in macrophages subjected to ER stress. METHODS Cultured human macrophages were subjected to ER stress by treating them with tunicamycin. Lipid uptake by macrophages subjected to ER stress in the presence or absence of TUDCA was assessed by oil red O staining and by assessing the cellular uptake of Dil-oxidized low-density lipoprotein by fluorescence measurement. Protein levels and phosphorylation status of ER stress markers, insulin-signaling molecules, and scavenger receptor were assessed by Western blotting. RESULTS Treatment of cultured human macrophages with the ER stressor tunicamycin caused an increase in the protein levels of cluster of differentiation 36 (CD-36) and augmentation of lipid uptake both of which were inhibited by TUDCA. TUDCA treatment inhibited tunicamycin-induced ER stress as evidenced by the attenuation of phosphorylation of eukaryotic translation initiation factor-2a and glucose reactive protein-78. In addition, TUDCA improved insulin signaling in macrophages by augmenting Akt phosphorylation and blunting c-Jun N-terminal kinase activity. CONCLUSIONS Inhibition of macrophage ER stress may represent a potential strategy in preventing atherogenesis under diabetic conditions.
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14
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O'Connor JC, Johnson DR, Freund GG. Psychoneuroimmune implications of type 2 diabetes: redux. Immunol Allergy Clin North Am 2009; 29:339-58. [PMID: 19389586 DOI: 10.1016/j.iac.2009.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A sizable body of knowledge has arisen demonstrating that type 2 diabetes (T2D) is associated with alterations in the innate immune system. The resulting proinflammatory-leaning imbalance is implicated in the development of secondary disease complications and comorbidities, such as delayed wound healing, accelerated progress of atherosclerosis, and retinopathy, in people who have T2D. New experimental data and the results of recently published health-related quality-of-life surveys indicate that individuals who have T2D experience diminished feelings of happiness, well being, and satisfaction with life. These emotional and psychological consequences of T2D point to altered neuroimmunity as a previously unappreciated complication of T2D. This article discusses recent data detailing the impact of T2D on a person's PNI response.
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Affiliation(s)
- Jason C O'Connor
- Department of Animal Sciences, University of Illinois, 1201 West Gregory Drive, Urbana, IL 61801, USA
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15
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Wu H, Xia X, Jiang C, Wu J, Zhang S, Zheng Z, Liu W, Zhang Y, Ren H, Wei C, Xu X. High glucose attenuates insulin-induced VEGF expression in bovine retinal microvascular endothelial cells. Eye (Lond) 2009; 24:145-51. [PMID: 19557019 DOI: 10.1038/eye.2009.157] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
PURPOSE To investigate the effect of high glucose on insulin-induced vascular endothelial growth factor (VEGF) expression in bovine retinal microvascular endothelial cells (BRECs) and to probe into related mechanisms. METHODS BRECs were isolated as primary cultures and identified by immunostaining. Passage cells were initially exposed to normal (5 mM) or high glucose (30 mM) for 3 days, and equimolar L-glucose was supplemented for osmotic equation. BRECs were then treated with 100 nM insulin for 24 h or not, and cells were prepared for the determination of VEGF mRNA expression by real-time PCR. VEGF protein was determined by human umbilical vein endothelial cell proliferation assay, immunofluorescence, and ELISA. BRECs were treated with 5 or 30 mM glucose for 3 days and then cells cultured with 5 mM glucose were exposed to the PI3-K inhibitor wortmannin (100 nM), the P42/44 mitogen-activated protein kinase (MAPK) inhibitor U0126 (50 microM), or to the protein kinase C (PKC) inhibitor GF109203X (2 microM) 1 h before addition of 100 nM insulin. Twenty-four hours after incubation with insulin, the cells were subjected to real-time PCR and ELISA analyses. RESULTS Insulin or high glucose alone markedly increased VEGF mRNA and protein levels in BRECs (P<0.05, two-way ANOVA). However, the combination of insulin and high glucose displayed a weaker effect in promoting VEGF expression than did insulin alone (P<0.05, t-test). Pretreatment of cells with PI3-K inhibitor significantly (P<0.05, one-way ANOVA) suppressed the insulin-induced VEGF expression; neither pretreatment with the PKC inhibitor nor with the P42/p44 MAPK inhibitor showed an effect on the expression of VEGF at the mRNA or protein level (P>0.05, one-way ANOVA). CONCLUSIONS Both insulin and high glucose can markedly increase VEGF expression in BRECs at the mRNA and protein level. We propose that insulin may upregulate VEGF expression through the PI3-K signalling pathway in BRECs, and high glucose may attenuate insulin-induced VEGF expression by impairing PI3-K signalling pathways.
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Affiliation(s)
- H Wu
- Department of Ophthalmology, The First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
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16
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González-Navarro H, Vinué A, Vila-Caballer M, Fortuño A, Beloqui O, Zalba G, Burks D, Díez J, Andrés V. Molecular Mechanisms of Atherosclerosis in Metabolic Syndrome. Arterioscler Thromb Vasc Biol 2008; 28:2187-94. [DOI: 10.1161/atvbaha.108.175299] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Objective—
The mechanisms underlying accelerated atherosclerosis in metabolic syndrome (MetS) patients remain poorly defined. In the mouse, complete disruption of insulin receptor substrate-2 (
Irs2
) causes insulin resistance, MetS-like manifestations, and accelerates atherosclerosis. Here, we performed human, mouse, and cell culture studies to gain insight into the contribution of defective
Irs2
signaling to MetS-associated alterations.
Methods and Results—
In circulating leukocytes from insulin-resistant MetS patients,
Irs2
and
Akt2
mRNA levels inversely correlate with plasma insulin levels and HOMA index and are reduced compared to insulin-sensitive MetS patients. Notably, a moderate reduction in
Irs2
expression in fat-fed
apolipoprotein E-null
mice lacking one allele of
Irs2
(
apoE
−/−
Irs2
+/−
) accelerates atherosclerosis compared to
apoE-null
controls, without affecting plaque composition. Partial
Irs2
inactivation also increases CD36 and SRA scavenger receptor expression and modified LDL uptake in macrophages, diminishes
Akt2
and
Ras
expression in aorta, and enhances expression of the proatherogenic cytokine MCP1 in aorta and primary vascular smooth muscle cells (VSMCs) and macrophages. Inhibition of AKT or ERK1/2, a downstream target of RAS, upregulates
Mcp1
in VSMCs.
Conclusions—
Enhanced levels of MCP1 resulting from reduced IRS2 expression and accompanying defects in AKT2 and Ras/ERK1/2 signaling pathways may contribute to accelerated atherosclerosis in MetS states.
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Affiliation(s)
- Herminia González-Navarro
- From the Laboratory of Vascular Biology (H.G.-N., A.V., M.V.-C., V.A.), Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, CSIC, Spain; the Division of Cardiovascular Sciences (A.F., O.B., G.Z., J.D.), Centre for Applied Medical Research; Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), School of Medicine, University of Navarra, Pamplona, Spain; and the Centro de Investigación Príncipe Felipe (D.B.), CIBER de Diabetes y
| | - Ángela Vinué
- From the Laboratory of Vascular Biology (H.G.-N., A.V., M.V.-C., V.A.), Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, CSIC, Spain; the Division of Cardiovascular Sciences (A.F., O.B., G.Z., J.D.), Centre for Applied Medical Research; Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), School of Medicine, University of Navarra, Pamplona, Spain; and the Centro de Investigación Príncipe Felipe (D.B.), CIBER de Diabetes y
| | - Marian Vila-Caballer
- From the Laboratory of Vascular Biology (H.G.-N., A.V., M.V.-C., V.A.), Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, CSIC, Spain; the Division of Cardiovascular Sciences (A.F., O.B., G.Z., J.D.), Centre for Applied Medical Research; Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), School of Medicine, University of Navarra, Pamplona, Spain; and the Centro de Investigación Príncipe Felipe (D.B.), CIBER de Diabetes y
| | - Ana Fortuño
- From the Laboratory of Vascular Biology (H.G.-N., A.V., M.V.-C., V.A.), Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, CSIC, Spain; the Division of Cardiovascular Sciences (A.F., O.B., G.Z., J.D.), Centre for Applied Medical Research; Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), School of Medicine, University of Navarra, Pamplona, Spain; and the Centro de Investigación Príncipe Felipe (D.B.), CIBER de Diabetes y
| | - Oscar Beloqui
- From the Laboratory of Vascular Biology (H.G.-N., A.V., M.V.-C., V.A.), Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, CSIC, Spain; the Division of Cardiovascular Sciences (A.F., O.B., G.Z., J.D.), Centre for Applied Medical Research; Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), School of Medicine, University of Navarra, Pamplona, Spain; and the Centro de Investigación Príncipe Felipe (D.B.), CIBER de Diabetes y
| | - Guillermo Zalba
- From the Laboratory of Vascular Biology (H.G.-N., A.V., M.V.-C., V.A.), Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, CSIC, Spain; the Division of Cardiovascular Sciences (A.F., O.B., G.Z., J.D.), Centre for Applied Medical Research; Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), School of Medicine, University of Navarra, Pamplona, Spain; and the Centro de Investigación Príncipe Felipe (D.B.), CIBER de Diabetes y
| | - Deborah Burks
- From the Laboratory of Vascular Biology (H.G.-N., A.V., M.V.-C., V.A.), Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, CSIC, Spain; the Division of Cardiovascular Sciences (A.F., O.B., G.Z., J.D.), Centre for Applied Medical Research; Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), School of Medicine, University of Navarra, Pamplona, Spain; and the Centro de Investigación Príncipe Felipe (D.B.), CIBER de Diabetes y
| | - Javier Díez
- From the Laboratory of Vascular Biology (H.G.-N., A.V., M.V.-C., V.A.), Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, CSIC, Spain; the Division of Cardiovascular Sciences (A.F., O.B., G.Z., J.D.), Centre for Applied Medical Research; Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), School of Medicine, University of Navarra, Pamplona, Spain; and the Centro de Investigación Príncipe Felipe (D.B.), CIBER de Diabetes y
| | - Vicente Andrés
- From the Laboratory of Vascular Biology (H.G.-N., A.V., M.V.-C., V.A.), Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia, CSIC, Spain; the Division of Cardiovascular Sciences (A.F., O.B., G.Z., J.D.), Centre for Applied Medical Research; Department of Cardiology and Cardiovascular Surgery, University Clinic (J.D.), School of Medicine, University of Navarra, Pamplona, Spain; and the Centro de Investigación Príncipe Felipe (D.B.), CIBER de Diabetes y
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Park MJ, Guest CB, Barnes MB, Martin J, Ahmad U, York JM, Freund GG. Blocking of beta-2 adrenergic receptors hastens recovery from hypoglycemia-associated social withdrawal. Psychoneuroendocrinology 2008; 33:1411-8. [PMID: 18814973 PMCID: PMC2636565 DOI: 10.1016/j.psyneuen.2008.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Revised: 08/04/2008] [Accepted: 08/10/2008] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Hypoglycemia is associated with a variety of adverse behaviors including fatigue, confusion and social withdrawal. While these clinical symptoms are well characterized, the mechanism of their cause is not understood. Here we investigated how insulin-induced hypoglycemia causes social withdrawal. RESEARCH DESIGN AND METHODS Male 8-12-week-old C57BL/6J mice were injected intraperitoneally (IP) with or without and/or insulin, norepinephrine (NE) and epinephrine (Epi), terbutaline and butoxamine with subsequent measurement of blood glucose, social withdrawal and plasma catecholamines. RESULTS Insulin generated (0.75h post-injection) significant hypoglycemia with blood glucose nadirs of 64+/-4 and 48+/-5mg/dl for 0.8 and 1.2units/kg of insulin, respectively. Insulin (0.8 or 1.2units/kg) caused near total social withdrawal at 0.75h with full recovery not occurring until 4h (0.8units/kg) or 8h (1.2units/kg) post-insulin injection. Insulin also caused a marked elevation in plasma catecholamines. Basal 12h fasting NE and Epi were 287+/-38 and 350+/-47pg/ml, respectively. Insulin at 0.8units/kg increased plasma NE and Epi to 994+/-73 and 1842+/-473pg/ml, respectively. Administration of exogenous NE or Epi caused social withdrawal similar in magnitude to insulin. Importantly, administration of the beta-2 adrenergic receptor agonist terbutaline also caused social withdrawal while administration of the beta-2 adrenergic receptor antagonist butoxamine blocked NE-induced social withdrawal. Finally, butoxamine blocked insulin-induced social withdrawal. CONCLUSIONS These data demonstrate that hypoglycemia-associated social withdrawal is dependent on catecholamines via a beta-2 receptor-mediated pathway.
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Affiliation(s)
- Min Jung Park
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Pathology, Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Christopher B. Guest
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Pathology, Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Meredith B. Barnes
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jonathan Martin
- Department of Pathology, Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Uzma Ahmad
- Department of Pathology, Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jason M. York
- Department of Pathology, Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Gregory G. Freund
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Pathology, Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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18
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Guest CB, Chakour KS, Freund GG. Macropinocytosis is decreased in diabetic mouse macrophages and is regulated by AMPK. BMC Immunol 2008; 9:42. [PMID: 18667079 PMCID: PMC2518915 DOI: 10.1186/1471-2172-9-42] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Accepted: 07/30/2008] [Indexed: 03/09/2023] Open
Abstract
BACKGROUND Macrophages (MPhis) utilize macropinocytosis to integrate immune and metabolic signals in order to initiate an effective immune response. Diabetes is characterized by metabolic abnormalities and altered immune function. Here we examine the influence of diabetes on macropinocytosis in primary mouse macrophages and in an in vitro diabetes model. RESULTS The data demonstrate that peritoneal MPhis from diabetic (db/db) mice had reduced macropinocytosis when compared to MPhis from non-diabetic (db/+) mice. Additionally, MPhis cultured in hyperglycemic conditions were less adept at macropinocytosis than those cultured in low glucose. Notably, AMP-activated protein kinase (AMPK) activity was decreased in MPhis cultured in hyperglycemic conditions. Activation of AMPK with leptin or 5-aminoimidazole-4-carboxamide-1-beta-riboside (AICAR) increased macropinocytosis and inhibition of AMPK with compound C decreased macropinocytosis. CONCLUSION Taken together, these findings indicate that MPhis from diabetic mice have decreased macropinocytosis. This decrease appears dependent on reduced AMPK activity. These results demonstrate a previously unrealized role for AMPK in MPhis and suggest that increasing AMPK activity in diabetic MPhis could improve innate immunity and decrease susceptibility to infection.
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Affiliation(s)
- Christopher B Guest
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, USA
- Pathology, College of Medicine, University of Illinois at Urbana-Champaign, Urbana, USA
| | - Kenneth S Chakour
- Pathology, College of Medicine, University of Illinois at Urbana-Champaign, Urbana, USA
| | - Gregory G Freund
- Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, USA
- Pathology, College of Medicine, University of Illinois at Urbana-Champaign, Urbana, USA
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19
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Surmi BK, Atkinson RD, Gruen ML, Coenen KR, Hasty AH. The role of macrophage leptin receptor in aortic root lesion formation. Am J Physiol Endocrinol Metab 2008; 294:E488-95. [PMID: 18182468 DOI: 10.1152/ajpendo.00374.2007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Plasma leptin is often elevated in obese individuals, and previous studies have suggested leptin as a factor that links obesity and atherosclerosis. Because macrophages play a key role in atherogenesis and are responsive to leptin, we hypothesized that leptin increases aortic root lesion formation, in part, through macrophage leptin receptor (LepR). Three different bone marrow transplantation studies were conducted in which bone marrow, with or without LepR, was transplanted into lethally irradiated 1) LDL receptor-deficient (LDLR(-/-)) mice with moderate hyperleptinemia due to Western diet (WD) feeding, 2) LDLR(-/-) mice with WD feeding plus pharmacologically induced hyperleptinemia (daily injection of 125 microg leptin), or 3) obese, hyperleptinemic, LepR-deficient LDLR(-/-) (LepR(db/db);LDLR(-/-)) mice. Minor differences in plasma parameters such as cholesterol, triglycerides, and insulin were observed in some groups; however, a consistent trend for the role of LepR on these parameters was not detected. In each of the studies, macrophage LepR expression did not have an effect on aortic root atherosclerotic lesion formation. These results suggest that nonhematopoietic cells may have a more significant role than macrophages in leptin-mediated effects on aortic root lesion formation.
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Affiliation(s)
- Bonnie K Surmi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232-0615, USA
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20
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Wang JY, Gualco E, Peruzzi F, Sawaya BE, Passiatore G, Marcinkiewicz C, Staniszewska I, Ferrante P, Amini S, Khalili K, Reiss K. Interaction between serine phosphorylated IRS-1 and beta1-integrin affects the stability of neuronal processes. J Neurosci Res 2007; 85:2360-73. [PMID: 17593555 PMCID: PMC3536502 DOI: 10.1002/jnr.21400] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Tumor necrosis factor-alpha (TNFalpha) released in the brain by HIV-activated macrophages/microglia is suspected to compromise neuronal survival. Previously, we have demonstrated that activated receptor for insulin-like growth factor I (IGF-IR) protects neurons from TNFalpha-induced neuronal damage (Wang et al. [ 2006] J. Neurosci. Res. 83:7-18). Because TNFalpha triggers phosphorylation of insulin receptor substrate 1 (IRS-1) on serine residues (pS-IRS-1; Rui et al. [ 2001] J. Clin. Invest. 107:181-189), and pS-IRS-1 binds integrins (Reiss et al. [ 2001] Oncogene 20:490-500), we asked how these events affect neuronal processes. We show that beta1-integrin and pS-IRS-1 colocalize in PC12 cells and in primary cortical neurons. TNFalpha treatment elevated membrane-associated pS-IRS-1, enhanced pS-IRS-1 interaction with beta1-integrin, and attenuated cell attachment to collagen IV. In contrast, IGF-I inhibited pS-IRS-1-beta1-integrin complexes and improved cell attachment. The domain of IRS-1 involved in beta1-integrin binding mapped between amino acids 426 and 740, and the expression of 426-740/IRS-1 mutant attenuated neuronal outgrowth. Our results indicate that TNFalpha facilitates the interaction of pS-IRS-1 and beta1-integrin and destabilizes neuronal processes. IGF-I counteracts TNFalpha-mediated accumulation of pS-IRS-1-beta1-integrin complexes supporting the stability of neuronal processes.
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Affiliation(s)
- Jin Ying Wang
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Elisa Gualco
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Francesca Peruzzi
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Bassel E. Sawaya
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Giovanni Passiatore
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Cezary Marcinkiewicz
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Izabella Staniszewska
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Pasquale Ferrante
- Laboratory of Molecular Medicine and Biotechnologies, Don C. Gnocchi Foundation, Milan, Italy
| | - Shohreh Amini
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
- Department of Biology, Temple University, Philadelphia, Pennsylvania
| | - Kamel Khalili
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Krzysztof Reiss
- Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, Philadelphia, Pennsylvania
- Correspondence to: Krzysztof Reiss, Center for Neurovirology, Department of Neuroscience, School of Medicine, Temple University, 1900 North 12th Street, Biology Life Science Building, Philadelphia, PA 19122.
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Abstract
The macrophage has emerged as an important player in the pathogenesis of both atherosclerosis and insulin resistance. Cross-talk between inflammatory macrophages and adipocytes may be involved in insulin resistance in peripheral tissues. Defective insulin signaling in cells of the arterial wall including macrophages may promote the development of atherosclerosis. Insulin resistant macrophages are more susceptible to endoplasmic reticulum stress and apoptosis in response to various stimuli such as nutrient deprivation, free cholesterol loading, and oxidized LDL. Increased apoptosis of insulin resistant macrophages and impaired phagocytic clearance of apoptotic cells by insulin resistant macrophages in atherosclerotic lesions may lead to enhanced postapoptotic necrosis, larger lipid-rich cores, increased inflammation, and more complex vulnerable plaques.
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Affiliation(s)
- Chien-Ping Liang
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY 10032, USA.
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22
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O'Connor JC, Sherry CL, Guest CB, Freund GG. Type 2 Diabetes Impairs Insulin Receptor Substrate-2-Mediated Phosphatidylinositol 3-Kinase Activity in Primary Macrophages to Induce a State of Cytokine Resistance to IL-4 in Association with Overexpression of Suppressor of Cytokine Signaling-3. THE JOURNAL OF IMMUNOLOGY 2007; 178:6886-93. [PMID: 17513737 DOI: 10.4049/jimmunol.178.11.6886] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Chronic elevation of proinflammatory markers in type 2 diabetes (T2D) is well defined, but the role of anti-inflammatory cytokines in T2D is less clear. In this study, we report that normal IL-4-dependent elaboration of IL-1 receptor antagonist (IL-1RA) requires IRS-2-mediated PI3K activity in primary macrophages. We also show that macrophages isolated from obese/diabetic db/db mice have impaired IRS-2-mediated PI3K activity and constitutively overexpress suppressor of cytokine signaling (SOCS)-3, which impairs an important IL-4 anti-inflammatory function. Peritoneal proinflammatory cytokine levels were examined in diabese (db/db) mice, and IL-6 was found to be nearly 7-fold higher than in nondiabese (db/+) control mice. Resident peritoneal macrophages were isolated from db/db mice and were found to constitutively overexpress IL-6 and were unable to elaborate IL-1RA in response to IL-4-like db/+ mouse macrophages. Inhibition of PI3K with wortmannin or blockage of IRS-2/PI3K complex formation with a cell permeable IRS-2-derived tyrosine phosphopeptide inhibited IL-4-dependent IL-1RA production in db/+ macrophages. Examination of IL-4 signaling in db/db macrophages revealed that IL-4-dependent IRS-2/PI3K complex formation and IRS-2 tyrosine phosphorylation was reduced compared with db/+ macrophages. SOCS-3/IL-4 receptor complexes, however, were increased in db/db mouse macrophages compared with db/+ mice macrophages as was db/db mouse macrophage SOCS-3 expression. These results indicate that in the db/db mouse model of T2D, macrophage expression of SOCS-3 is increased, and impaired IL-4-dependent IRS-2/PI3K formation induces a state of IL-4 resistance that disrupts IL-4-dependent production of IL-1RA.
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Affiliation(s)
- Jason C O'Connor
- Division of Nutritional Sciences, Integrative Immunology and Behavior Program, University of Illinois, Urbana, IL 61801, USA
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23
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Sherry CL, O'Connor JC, Kramer JM, Freund GG. Augmented Lipopolysaccharide-Induced TNF-α Production by Peritoneal Macrophages in Type 2 Diabetic Mice Is Dependent on Elevated Glucose and Requires p38 MAPK. THE JOURNAL OF IMMUNOLOGY 2007; 178:663-70. [PMID: 17202326 DOI: 10.4049/jimmunol.178.2.663] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dysregulated inflammation is a complication of type 2 diabetes (T2D). In this study, we show that augmented LPS-induced TNF-alpha production by resident peritoneal macrophages (PerMphi) in type 2 diabetic (db/db) mice is dependent on elevated glucose and requires p38 MAPK. Intraperitoneal LPS administered to db/db and nondiabetic (db/+) mice induced 3- and 4-fold more TNF-alpha in the peritoneum and serum, respectively, of db/db mice as compared with db/+ mice. Examination of the TLR-4/MD2 complex and CD14 expression showed no difference between db/db and db/+ PerMphi. Ex vivo stimulation of PerMphi with LPS produced a similar 3-fold increase in TNF-alpha production in db/db PerMphi when compared with db/+ PerMphi. PerMphi isolated from db/+ mice incubated in high glucose (4 g/L) medium for 12 h produced nearly 2-fold more TNF-alpha in response to LPS than PerMphi incubated in normal glucose medium (1 g/L). LPS-dependent stimulation of PI3K activity, ERK1/2 activation, and p38 kinase activity was greater in PerMphi from db/db mice as compared with db/+ mice. Only inhibition of p38 kinase blocked LPS-induced TNF-alpha production in PerMphi from db/db mice. Taken together, these data indicate that augmented TNF-alpha production induced by LPS in macrophages during diabetes is due to hyperglycemia and increased LPS-dependent activation of p38 kinase.
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Affiliation(s)
- Christina L Sherry
- Division of Nutritional Sciences, Integrative Immunology and Behavior Program, University of Illinois, 506 South Mathews Avenue, Urbana, IL 61801, USA
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24
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Abstract
The idea that type 2 diabetes is associated with augmented innate immune function characterized by increased circulating levels of acute phase reactants and altered macrophage biology is fairly well established, even though the mechanisms involved in this complex interaction still are not entirely clear. To date, the majority of studies investigating innate immune function in type 2 diabetes are limited to the context of wound healing, atherosclerosis, stroke, and other commonly identified comorbidities. Several important recurring themes come out of these data. First, type 2 diabetes is associated with a state of chronic, subclinical inflammation. Second, in macrophages, type 2 diabetic conditions enhance proinflammatory reactions and impair anti-inflammatory responses. Third, after acute activation of the innate immune system in type 2 diabetes, recovery or resolution of inflammation is impaired. The consequences of type 2 diabetes-associated inflammatory alterations on PNI processes have been recognized only recently. Given the impact of diminished emotional well-being on the quality of life in patients who have type 2 diabetes, diabetes-induced exacerbation of PNI responses should be considered a serious complication of type 2 diabetes that warrants further clinical attention.
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Affiliation(s)
- Jason C O'Connor
- Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801, USA
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25
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Baumgartl J, Baudler S, Scherner M, Babaev V, Makowski L, Suttles J, McDuffie M, Fazio S, Kahn CR, Hotamisligil GS, Krone W, Linton M, Brüning JC. Myeloid lineage cell-restricted insulin resistance protects apolipoproteinE-deficient mice against atherosclerosis. Cell Metab 2006; 3:247-56. [PMID: 16581002 PMCID: PMC4027059 DOI: 10.1016/j.cmet.2006.02.010] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2004] [Revised: 12/07/2005] [Accepted: 02/17/2006] [Indexed: 11/30/2022]
Abstract
Inflammatory processes play an important role in the pathogenesis of vascular diseases, and insulin-resistant diabetes mellitus type 2 represents an important risk factor for the development of atherosclerosis. To directly address the role of insulin resistance in myeloid lineage cells in the development of atherosclerosis, we have created mice with myeloid lineage-specific inactivation of the insulin receptor gene. On an ApoE-deficient background, MphIRKO mice developed smaller atherosclerotic lesions. There was a dramatic decrease in LPS-stimulated IL-6 and IL-1beta expression in the presence of macrophage autonomous insulin resistance. Consistently, while insulin-resistant IRS-2-deficient mice on an ApoE-deficient background display aggravated atherosclerosis, fetal liver cell transplantation of IRS-2(-/-) ApoE(-/-) cells ameliorated atherosclerosis in Apo-E-deficient mice. Thus, systemic versus myeloid cell-restricted insulin resistance has opposing effects on the development of atherosclerosis, providing direct evidence that myeloid lineage autonomous insulin signaling provides proinflammatory signals predisposing to the development of atherosclerosis.
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Affiliation(s)
- Julia Baumgartl
- Institute for Genetics, University of Cologne and Center of Molecular Medicine Cologne, D-50931 Cologne, Germany
| | - Stephanie Baudler
- Institute for Genetics, University of Cologne and Center of Molecular Medicine Cologne, D-50931 Cologne, Germany
| | - Maximilian Scherner
- Klinik II und Poliklinik für Innere Medizin der Universität zu Köln and Center of Molecular Medicine Cologne, D-50931 Cologne, Germany
| | - Vladimir Babaev
- Cardiovasular Medicine Division, Vanderbilt University, Nashville, Tennessee 37235
| | - Liza Makowski
- Division of Biological Sciences and Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, 02215
| | - Jill Suttles
- Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, Kentucky, 40292
| | - Marcia McDuffie
- University of Virginia School of Medicine, Charlottesville, Virginia, 22908
| | - Sergio Fazio
- Cardiovasular Medicine Division, Vanderbilt University, Nashville, Tennessee 37235
| | - C. Ronald Kahn
- Joslin Diabetes Center, Harvard Medical School. Boston, Massachusetts 02115
| | - Gökhan S. Hotamisligil
- Division of Biological Sciences and Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, 02215
| | - Wilhelm Krone
- Klinik II und Poliklinik für Innere Medizin der Universität zu Köln and Center of Molecular Medicine Cologne, D-50931 Cologne, Germany
| | - MacRae Linton
- Cardiovasular Medicine Division, Vanderbilt University, Nashville, Tennessee 37235
| | - Jens C. Brüning
- Institute for Genetics, University of Cologne and Center of Molecular Medicine Cologne, D-50931 Cologne, Germany
- Correspondence:
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26
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Murakami Y, Akahoshi T, Hayashi I, Endo H, Kawai S, Inoue M, Kondo H, Kitasato H. Induction of triggering receptor expressed on myeloid cells 1 in murine resident peritoneal macrophages by monosodium urate monohydrate crystals. ACTA ACUST UNITED AC 2006; 54:455-62. [PMID: 16447220 DOI: 10.1002/art.21633] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Triggering receptor expressed on myeloid cells 1 (TREM-1) is a cell surface molecule that was recently identified on monocytes and neutrophils. TREM-1 has been implicated in the early inflammatory responses induced by microbes, but its pathophysiologic role in nonmicrobial inflammation remains unknown. In the present study, we investigated the role of TREM-1 in acute inflammation induced by monosodium urate monohydrate (MSU) crystals. Induction of TREM-1 expression by MSU crystal-stimulated murine resident peritoneal macrophages and infiltrating leukocytes in a murine air-pouch model of crystal-induced acute inflammation was determined. The biologic role of TREM-1 in crystal-induced cytokine production by resident peritoneal macrophages was also investigated. METHODS TREM-1 expression by resident peritoneal macrophages and infiltrating leukocytes in a murine air-pouch model was determined by quantitative real-time polymerase chain reaction, Western blot analysis, and flow cytometry. Cytokine production by resident peritoneal macrophages after incubation with MSU crystals in the presence or absence of an anti-TREM-1 agonist antibody was determined by enzyme-linked immunosorbent assay. RESULTS TREM-1 expression by resident peritoneal macrophages was significantly induced after stimulation with the crystals. Maximum expression of TREM-1 transcripts and protein occurred at 1 and 4 hours after exposure to the crystals, respectively. Costimulation of resident peritoneal macrophages with MSU crystals and an anti-TREM-1 agonist antibody synergistically increased the production of both interleukin-1beta and monocyte chemotactic protein 1 compared with stimulation with the crystals alone. MSU crystals also induced TREM-1 expression in infiltrating leukocytes in a murine air-pouch model of crystal-induced acute inflammation. CONCLUSION These findings suggest that rapid induction of TREM-1 expression on resident peritoneal macrophages and neutrophils by MSU crystals may contribute to the development of acute gout through enhancement of inflammatory responses.
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MESH Headings
- Acute Disease
- Animals
- Antibodies, Blocking/pharmacology
- Crystallization
- Cytokines/metabolism
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drug Synergism
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/physiology
- Inflammation/chemically induced
- Inflammation/immunology
- Inflammation/metabolism
- Macrophages, Peritoneal/drug effects
- Macrophages, Peritoneal/immunology
- Macrophages, Peritoneal/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred ICR
- RNA, Messenger/analysis
- Receptors, Immunologic/biosynthesis
- Receptors, Immunologic/genetics
- Receptors, Immunologic/immunology
- Uric Acid/pharmacology
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27
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Johnson DR, O'Connor JC, Satpathy A, Freund GG. Cytokines in type 2 diabetes. VITAMINS AND HORMONES 2006; 74:405-41. [PMID: 17027525 DOI: 10.1016/s0083-6729(06)74017-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Daniel R Johnson
- Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801, USA
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28
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Johnson DR, O'Connor JC, Dantzer R, Freund GG. Inhibition of vagally mediated immune-to-brain signaling by vanadyl sulfate speeds recovery from sickness. Proc Natl Acad Sci U S A 2005; 102:15184-9. [PMID: 16217019 PMCID: PMC1257721 DOI: 10.1073/pnas.0507191102] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Indexed: 01/04/2023] Open
Abstract
To the ill patient with diabetes, the behavioral symptoms of sickness such as fatigue and apathy are debilitating and can prevent recuperation. Here we report that peripherally administered insulin-like growth factor 1 (IGF-1) attenuates LPS-dependent depression of social exploration (sickness) in nondiabetic (db/+) but not in diabetic (db/db) mice. We show that the insulin/IGF-1 mimetic vanadyl sulfate (VS) is effective at augmenting recovery from sickness in both db/+ and db/db mice. Specifically, peak illness was reached at 2 h for both VS and control animals injected with LPS, and VS mice recovered 50% faster than non-VS-treated animals. Examination of the mechanism of VS action in db/+ mice showed that VS paradoxically augmented peritoneal macrophage responsivity to LPS, increasing both peritoneal and ex vivo macrophage production of IL-1beta and IL-6 but not TNF-alpha. The effects of VS in promoting recovery from sickness were not restricted to LPS, because they were also observed after direct administration of IL-1beta. To explore the possibility that VS impairs immune-to-brain communication via vagal afferents, the vagally mediated satiety-inducing effects of cholecystokinin 8 were tested in db/+ mice. Cholecystokinin decreased food intake in saline-injected mice but not in VS-treated mice. VS also inhibited LPS-dependent up-regulation of IL-1beta and IL-6 mRNA in the brain, while increasing by 50% the cerebral expression of transcripts of the specific antagonist of IL-1 receptors IL-1RA and IL-1R2. Taken together, these data indicate that VS improves recovery from LPS-induced sickness by blocking vagally mediated immune-to-brain signaling and by up-regulating brain expression of IL-1beta antagonists.
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Affiliation(s)
- Daniel R Johnson
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Stout RD, Suttles J. Immunosenescence and macrophage functional plasticity: dysregulation of macrophage function by age-associated microenvironmental changes. Immunol Rev 2005; 205:60-71. [PMID: 15882345 PMCID: PMC1201508 DOI: 10.1111/j.0105-2896.2005.00260.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The macrophage lineage displays extreme functional and phenotypic heterogeneity, which appears to be because, in large part, of the ability of macrophages to functionally adapt to changes in their tissue microenvironment. This functional plasticity of macrophages plays a critical role in their ability to respond to tissue damage and/or infection and to contribute to clearance of damaged tissue and invading microorganisms, to recruitment of the adaptive immune system, and to resolution of the wound and of the immune response. Evidence has accumulated that environmental influences, such as stromal function and imbalances in hormones and cytokines, contribute significantly to the dysfunction of the adaptive immune system. The innate immune system also appears to be dysfunctional in aged animals and humans. In this review, the hypothesis is presented and discussed that the observed age-associated 'dysfunction' of macrophages is the result of their functional adaptation to the age-associated changes in tissue environments. The resultant loss of orchestration of the manifold functional capabilities of macrophages would undermine the efficacy of both the innate and adaptive immune systems. The macrophages appear to maintain functional plasticity during this dysregulation, making them a prime target of cytokine therapy that could enhance both innate and adaptive immune systems.
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Affiliation(s)
- Robert D Stout
- Department of Microbiology and Immunology, University of Louisville School of Medicine, KY 40292, USA.
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30
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O'Connor JC, Satpathy A, Hartman ME, Horvath EM, Kelley KW, Dantzer R, Johnson RW, Freund GG. IL-1beta-mediated innate immunity is amplified in the db/db mouse model of type 2 diabetes. THE JOURNAL OF IMMUNOLOGY 2005; 174:4991-7. [PMID: 15814729 DOI: 10.4049/jimmunol.174.8.4991] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Chronic inflammation appears to play a critical role in type 2 diabetes and its complications. Here we tested the hypothesis that this inflammatory dysregulation affects the IL-1beta system and has functional consequences in the brain. Diabetic, db/db, and nondiabetic, db/+, mice were administered i.p. LPS, a potent cytokine inducer, at a dose of 100 microg/kg/mouse. db/db mouse innate immune-associated sickness behavior was 14.8, 33, 44.7, and 34% greater than that of db/+ mice at 2, 4, 8, and 12 h, respectively. When a fixed dose of LPS was used (5 microg/mouse), db/db mouse sickness was again enhanced 18.4, 22.2, and 14.5% at 4, 8, and 12 h as compared with db/+ mice. In diabetic mice, peritoneal macrophages produced more IL-1beta in response to LPS, and peritoneal levels of IL-1beta induced by LPS were increased. Importantly, IL-1R antagonist and type 2 IL-1 receptor (IL-1R2) failed to up-regulate in response to LPS in db/db mice. Finally, both peripheral and central administration of IL-1beta, itself, induced sickness in db/db mice that mimicked the effects of peripheral LPS and was significantly greater than that seen in db/+ mice. Taken together, these results indicate that IL-1beta-mediated innate immunity is augmented in db/db mice both at the periphery and in the brain, and the mechanism is due to diabetes-associated loss of IL-1beta counterregulation.
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MESH Headings
- Animals
- Base Sequence
- Brain/immunology
- DNA/genetics
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/immunology
- Immunity, Innate
- Interleukin 1 Receptor Antagonist Protein
- Interleukin-1/administration & dosage
- Interleukin-1/antagonists & inhibitors
- Interleukin-1/genetics
- Interleukin-1/metabolism
- Lipopolysaccharides/toxicity
- Macrophages, Peritoneal/drug effects
- Macrophages, Peritoneal/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Models, Immunological
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Interleukin-1/genetics
- Receptors, Interleukin-1/metabolism
- Receptors, Interleukin-1 Type II
- Recombinant Proteins/administration & dosage
- Sialoglycoproteins/genetics
- Sialoglycoproteins/metabolism
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Affiliation(s)
- Jason C O'Connor
- Department of Animal Sciences, University of Illinois at Urbana Champain, Urbana, IL 61801, USA
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