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Kruglov V, Jang IH, Camell CD. Inflammaging and fatty acid oxidation in monocytes and macrophages. IMMUNOMETABOLISM (COBHAM, SURREY) 2024; 6:e00038. [PMID: 38249577 PMCID: PMC10798594 DOI: 10.1097/in9.0000000000000038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 12/27/2023] [Indexed: 01/23/2024]
Abstract
Fatty acid oxidation (FAO), primarily known as β-oxidation, plays a crucial role in breaking down fatty acids within mitochondria and peroxisomes to produce cellular energy and preventing metabolic dysfunction. Myeloid cells, including macrophages, microglia, and monocytes, rely on FAO to perform essential cellular functions and uphold tissue homeostasis. As individuals age, these cells show signs of inflammaging, a condition that includes a chronic onset of low-grade inflammation and a decline in metabolic function. These lead to changes in fatty acid metabolism and a decline in FAO pathways. Recent studies have shed light on metabolic shifts occurring in macrophages and monocytes during aging, correlating with an altered tissue environment and the onset of inflammaging. This review aims to provide insights into the connection of inflammatory pathways and altered FAO in macrophages and monocytes from older organisms. We describe a model in which there is an extended activation of receptor for advanced glycation end products, nuclear factor-κB (NF-κB) and the nod-like receptor family pyrin domain containing 3 inflammasome within macrophages and monocytes. This leads to an increased level of glycolysis, and also promotes pro-inflammatory cytokine production and signaling. As a result, FAO-related enzymes such as 5' AMP-activated protein kinase and peroxisome proliferator-activated receptor-α are reduced, adding to the escalation of inflammation, accumulation of lipids, and heightened cellular stress. We examine the existing body of literature focused on changes in FAO signaling within macrophages and monocytes and their contribution to the process of inflammaging.
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Affiliation(s)
- Victor Kruglov
- Department of Biochemistry, Molecular Biology, and Biophysics, Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA
| | - In Hwa Jang
- Department of Biochemistry, Molecular Biology, and Biophysics, Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA
| | - Christina D. Camell
- Department of Biochemistry, Molecular Biology, and Biophysics, Institute on the Biology of Aging and Metabolism, University of Minnesota, Minneapolis, MN, USA
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2
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The Role of IL-13 and IL-4 in Adipose Tissue Fibrosis. Int J Mol Sci 2023; 24:ijms24065672. [PMID: 36982747 PMCID: PMC10051142 DOI: 10.3390/ijms24065672] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/18/2023] Open
Abstract
White adipose tissue (WAT) fibrosis, characterized by an excess of extracellular (ECM) matrix components, is strongly associated with WAT inflammation and dysfunction due to obesity. Interleukin (IL)-13 and IL-4 were recently identified as critical mediators in the pathogenesis of fibrotic diseases. However, their role in WAT fibrosis is still ill-defined. We therefore established an ex vivo WAT organotypic culture system and demonstrated an upregulation of fibrosis-related genes and an increase of α-smooth muscle actin (αSMA) and fibronectin abundance upon dose-dependent stimulation with IL-13/IL-4. These fibrotic effects were lost in WAT lacking il4ra, which encodes for the underlying receptor controlling this process. Adipose tissue macrophages were found to play a key role in mediating IL-13/IL-4 effects in WAT fibrosis as their depletion through clodronate dramatically decreased the fibrotic phenotype. IL-4-induced WAT fibrosis was partly confirmed in mice injected intraperitoneally with IL-4. Furthermore, gene correlation analyses of human WAT samples revealed a strong positive correlation of fibrosis markers with IL-13/IL-4 receptors, whereas IL13 and IL4 correlations failed to confirm this association. In conclusion, IL-13 and IL-4 can induce WAT fibrosis ex vivo and partly in vivo, but their role in human WAT remains to be further elucidated.
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3
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Kim KD, Choe JM, Myoung S, Lee SH, Kim M, Choi JH, Park HT. Estradiol treatment increases M2-like visceral adipose tissue macrophages in obese ovariectomized mice regardless of its anorectic action. Anim Cells Syst (Seoul) 2022; 26:243-253. [PMID: 36275444 PMCID: PMC9586618 DOI: 10.1080/19768354.2022.2128871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Estradiol (E2) treatment has been known to induce changes in food intake, energy expenditure, and weight gain. However, its direct effects on adipose tissue macrophages (ATM) in vivo are not fully understood. Thus, we aimed to explore this aspect at cellular and molecular levels in ovariectomized obese mice. We examined the changes in ATMs after eight weeks of a high-fat diet (HFD) in male, female, and ovariectomized (OVX) mice. After eight weeks, osmotic pumps were inserted into OVX mice to provide two weeks of E2 treatment. We additionally set up a vehicle Pair-Fed (PF) control group that supplied the same amount of HFD consumed by the E2-treated group. We then investigated the in vivo phenotypic changes of visceral adipose tissue (VAT) macrophages. The percentage of M1-like ATMs decreased by the anorectic effect of E2, while M2-like ATMs increased regardless of the anorexia. E2 treatment increased the expression of anti-inflammatory genes but decreased pro-inflammatory genes in VAT. Monocyte recruitment and local proliferation contributed to M2-like ATMs. Furthermore, M2-like phenotypes were induced by E2 treatment in human macrophages. E2 treatment increases M2-like macrophages and improves the tissue milieu of VAT regardless of the anorectic reaction of E2.
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Affiliation(s)
- Kyeong-dae Kim
- Department of Life Science, College of Natural Sciences, Research Institute for Natural Sciences, Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, Republic of Korea
| | - Jeong Min Choe
- Department of Obstetrics and Gynecology, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Soomin Myoung
- Department of Obstetrics and Gynecology, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Seung Hyun Lee
- Department of Life Science, College of Natural Sciences, Research Institute for Natural Sciences, Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, Republic of Korea
| | - Minkyu Kim
- Department of Life Science, College of Natural Sciences, Research Institute for Natural Sciences, Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, Republic of Korea
| | - Jae-Hoon Choi
- Department of Life Science, College of Natural Sciences, Research Institute for Natural Sciences, Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, Republic of Korea
| | - Hyun Tae Park
- Department of Obstetrics and Gynecology, College of Medicine, Korea University, Seoul, Republic of Korea
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4
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Macrophage Polarization Mediated by Mitochondrial Dysfunction Induces Adipose Tissue Inflammation in Obesity. Int J Mol Sci 2022; 23:ijms23169252. [PMID: 36012516 PMCID: PMC9409464 DOI: 10.3390/ijms23169252] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 12/06/2022] Open
Abstract
Obesity is one of the prominent global health issues, contributing to the growing prevalence of insulin resistance and type 2 diabetes. Chronic inflammation in adipose tissue is considered as a key risk factor for the development of insulin resistance and type 2 diabetes in obese individuals. Macrophages are the most abundant immune cells in adipose tissue and play an important role in adipose tissue inflammation. Mitochondria are critical for regulating macrophage polarization, differentiation, and survival. Changes to mitochondrial metabolism and physiology induced by extracellular signals may underlie the corresponding state of macrophage activation. Macrophage mitochondrial dysfunction is a key mediator of obesity-induced macrophage inflammatory response and subsequent systemic insulin resistance. Mitochondrial dysfunction drives the activation of the NLRP3 inflammasome, which induces the release of IL-1β. IL-1β leads to decreased insulin sensitivity of insulin target cells via paracrine signaling or infiltration into the systemic circulation. In this review, we discuss the new findings on how obesity induces macrophage mitochondrial dysfunction and how mitochondrial dysfunction induces NLRP3 inflammasome activation. We also summarize therapeutic approaches targeting mitochondria for the treatment of diabetes.
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5
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Petrie RJ. Visualizing Cell Motility in Mouse Ear Explants. Curr Protoc 2022; 2:e434. [PMID: 35532288 DOI: 10.1002/cpz1.434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A method to visualize cell motility in fluorescence-labeled mouse-ear dermal explants is described. This approach allows cell and matrix dynamics to be visualized in physiologically relevant, three-dimensional (3D) environments. This Basic Protocol for the preparation of mouse-ear dermal explants can be optimized and applied to any tissue explant and cell type. © 2022 Wiley Periodicals LLC.
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Affiliation(s)
- Ryan J Petrie
- Department of Biology, Drexel University, Philadelphia, Pennsylvania
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6
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Gopal SS, Kasiappan R, Vallikannan B, Ponesakki G. Effective inhibition of adipogenesis-mediated inflammation by a macular carotenoid, lutein in vitro. J Food Biochem 2022; 46:e14211. [PMID: 35488719 DOI: 10.1111/jfbc.14211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 03/31/2022] [Accepted: 04/05/2022] [Indexed: 11/29/2022]
Abstract
An absolute interlinks between inflammation and obesity with scarce investigations on the role of lutein in inflammation-induced obesity motivated us to explore the protective mechanism of lutein on adipogenesis-mediated inflammation in vitro by culturing RAW264.7 macrophages in adipocyte conditioned medium. The RAW264 macrophage cells were cultured with adipocyte-conditioned media, and the potency of lutein on the expression of adipocyte inflammation-associated protein markers (IL-1β, MCP-1, TNF-α, IL-6, NF-κB, and IKKα/β) were analyzed by western blotting. The data revealed that lutein effectively reduces the protein levels of major inflammatory markers such as NF-κB, IL-1β, MCP-1, and TNF-α in differentiated adipocytes. Interestingly, lutein hampered inflammation in the RAW264 cells that were cultured in adipocyte-conditioned media by lowering the protein expression of IL-1β, MCP-1, and TNF-α. The blockage of inflammation by lutein in both differentiated adipocytes, and adipogenesis-induced macrophages is associated with suppression of IKK α/β phosphorylation. These data suggest that lutein potentially alters adipocyte differentiation-mediated inflammation by regulating the NF-κB signaling pathway. Thus, lutein could be utilized as a potent nutraceutical agent in the management of obesity and associated inflammation. PRACTICAL APPLICATIONS: Lutein isolated from a dietary source exhibited an inhibitory effect in adipogenesis-induced inflammations. The findings of this study authenticate the diversified prospective of lutein in regulating obesity and other inflammation-related diseases. Thus, it is understood that continuous intake of lutein-rich food or dietary intervention of lutein may reduce the risk of developing obesity.
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Affiliation(s)
- Sowmya Shree Gopal
- Department of Molecular Nutrition, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Ravi Kasiappan
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Department of Biochemistry, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, India
| | - Baskaran Vallikannan
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Department of Biochemistry, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, India
| | - Ganesan Ponesakki
- Department of Molecular Nutrition, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.,Department of Biochemistry and Biotechnology, CSIR-Central Leather Research Institute (CLRI), Chennai, India
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7
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Liu X, Chu H, Ji Y, Bosnjak Z, Ao H, Li T. Which BMI for Diabetes Patients is Better? From the View of the Adipose Tissue Macrophage-Derived Exosome. Diabetes Metab Syndr Obes 2022; 15:141-153. [PMID: 35046685 PMCID: PMC8763208 DOI: 10.2147/dmso.s345890] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 12/24/2021] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Diabetes, as a group of metabolic diseases, can elevate blood glucose, thus leading to the development of life-threatening complications. It is difficult to define the outcome for diabetics with different BMI. This review will illustrate the adipose tissue macrophage-derived exosome in the diabetics with different BMI. PATIENTS AND METHODS Insulin resistance in peripheral tissues can cause diabetes. The peripheral tissues include liver, muscle, or the adipose depots. Communication between these organs is fatal to the maintenance of glucose homeostasis. This review will illustrate this communication. Obesity is closely linked with diabetes. There are different changes in fat distribution in diabetic patients. Adipose tissue macrophages can secrete various hormones, including adiponectin, leptin, resistin and other classical cytokines, such as TNF-α and IL-6. Studies illustrated that exosomes from the adipose tissue, can modulate inter-organ cross-talk by regulating gene expression in other tissues. RESULTS Adipose tissue macrophages exosomes links thin and fat individuals in the development of diabetes. CONCLUSION The molecular pathways initiated by exosomes such as miRNA in the situations of metabolic stress could help us gain a deeper knowledge of the pathophysiology of diabetes.
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Affiliation(s)
- Xiaojie Liu
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, People’s Republic of China
- Departments of Medicine and Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Anesthesiology, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China
| | - Haichen Chu
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, People’s Republic of China
| | - Yuzhi Ji
- Obstetrics, Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, People’s Republic of China
| | - Zeljko Bosnjak
- Departments of Medicine and Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Hushan Ao
- Department of Anesthesiology, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China
- Correspondence: Hushan Ao Department of Anesthesiology, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No.167 North Lishi Road, Xicheng District, Beijing, People’s Republic of ChinaTel/Fax +86-10-68006210 Email
| | - Tianjun Li
- Department of Oncology, Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, People’s Republic of China
- Tianjun Li Department of Oncology, Affiliated Hospital of Qingdao University, No. 59 Haier Road, Laoshan District, Qingdao, Shandong Province, People’s Republic of ChinaTel/Fax +86-10-82913035 Email
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8
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Ma S, Murakami K, Saito R, Ito H, Murata K, Nishitani K, Hashimoto M, Tanaka M, Taniguchi M, Kitagori K, Akizuki S, Nakashima R, Yoshifuji H, Ohmura K, Morinobu A, Mimori T. Increased Ratio of CD14 ++CD80 + Cells/CD14 ++CD163 + Cells in the Infrapatellar Fat Pad of End-Stage Arthropathy Patients. Front Immunol 2021; 12:774177. [PMID: 34899727 PMCID: PMC8662627 DOI: 10.3389/fimmu.2021.774177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 11/08/2021] [Indexed: 01/02/2023] Open
Abstract
Objectives This study sought to identify the ratio of M1/M2 cells in the infrapatellar fat pads (IFP) and subcutaneous fat tissues (SC) of osteoarthritis (OA) and rheumatoid arthritis (RA) patients. The clinical features of OA and RA patients treated with or without biological disease-modifying anti-rheumatic drugs (bDMARDs) were also assessed. Methods IFP and SC were collected from patients with OA and RA who are undergoing total knee arthroplasty (TKA). CD14-positive cells were then isolated from these samples. Flow cytometry was used to determine the number of CD14++CD80+ cells and CD14++CD163+ cells. The expression levels of lipid transcription factors, such as sterol regulatory element-binding protein 1 (SREBP1) and liver X receptor alpha (LXRA), and inflammatory cytokines were also evaluated. Results Twenty OA patients and 22 RA patients were enrolled in this study. Ten of the RA patients (45.4%) received bDAMRDs before TKA. On average, a fivefold increase in the number of CD14-positive cells and lower expression levels of SREBP1C and LXRA were observed in OA IFP relative to OA SC; however, these results were not obtained from the RA samples. The median ratio of CD14++CD80+ cells/CD14++CD163+ cells of OA IFP was 0.87 (0.76–1.09, interquartile range), which is higher to that of OA SC with a lower ratio (p = 0.05835). Conclusions The quantity and quality of CD14-positive cells differed between IFP and SC in arthropathy patients. To our knowledge, this is the first study to characterize the ratio of M1/M2 cells in the IFP and SC of end-stage OA and RA patients. The increased ratio of CD14++CD80+ cells/CD14++CD163+ cells in the IFP from patients with OA and RA treated with bDMARDs indicated that inflammation was localized in the IFP. As adipose tissue-derived innate immune cells were revealed as one of the targets for regulating inflammation, further analysis of these cells in the IFP may reveal new therapeutic strategies for inflammatory joint diseases.
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Affiliation(s)
- Shuhe Ma
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kosaku Murakami
- Center for Cancer Immunotherapy and Immunobiology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Rintaro Saito
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiromu Ito
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Orthopaedic Surgery, Kurashiki Central Hospital, Okayama, Japan
| | - Koichi Murata
- Department for Advanced Medicine for Rheumatic Disease, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kohei Nishitani
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Motomu Hashimoto
- Department for Advanced Medicine for Rheumatic Disease, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Clinical Immunology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Masao Tanaka
- Department for Advanced Medicine for Rheumatic Disease, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masahi Taniguchi
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Koji Kitagori
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shuji Akizuki
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ran Nakashima
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hajime Yoshifuji
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Koichiro Ohmura
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akio Morinobu
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tsuneyo Mimori
- Department of Rheumatology and Clinical Immunology, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Ijinkai Takeda General Hospital, Kyoto, Japan
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9
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Modelling and Differential Quantification of Electric Cell-Substrate Impedance Sensing Growth Curves. SENSORS 2021; 21:s21165286. [PMID: 34450726 PMCID: PMC8401457 DOI: 10.3390/s21165286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/26/2021] [Accepted: 08/02/2021] [Indexed: 11/29/2022]
Abstract
Measurement of cell surface coverage has become a common technique for the assessment of growth behavior of cells. As an indirect measurement method, this can be accomplished by monitoring changes in electrode impedance, which constitutes the basis of electric cell-substrate impedance sensing (ECIS). ECIS typically yields growth curves where impedance is plotted against time, and changes in single cell growth behavior or cell proliferation can be displayed without significantly impacting cell physiology. To provide better comparability of ECIS curves in different experimental settings, we developed a large toolset of R scripts for their transformation and quantification. They allow importing growth curves generated by ECIS systems, edit, transform, graph and analyze them while delivering quantitative data extracted from reference points on the curve. Quantification is implemented through three different curve fit algorithms (smoothing spline, logistic model, segmented regression). From the obtained models, curve reference points such as the first derivative maximum, segmentation knots and area under the curve are then extracted. The scripts were tested for general applicability in real-life cell culture experiments on partly anonymized cell lines, a calibration setup with a cell dilution series of impedance versus seeded cell number and finally IPEC-J2 cells treated with 1% and 5% ethanol.
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10
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Adipocyte death triggers a pro-inflammatory response and induces metabolic activation of resident macrophages. Cell Death Dis 2021; 12:579. [PMID: 34091595 PMCID: PMC8179930 DOI: 10.1038/s41419-021-03872-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 12/23/2022]
Abstract
A chronic low-grade inflammation within adipose tissue (AT) seems to be the link between obesity and some of its associated diseases. One hallmark of this AT inflammation is the accumulation of AT macrophages (ATMs) around dead or dying adipocytes, forming so-called crown-like structures (CLS). To investigate the dynamics of CLS and their direct impact on the activation state of ATMs, we established a laser injury model to deplete individual adipocytes in living AT from double reporter mice (GFP-labeled ATMs and tdTomato-labeled adipocytes). Hence, we were able to detect early ATM-adipocyte interactions by live imaging and to determine a precise timeline for CLS formation after adipocyte death. Further, our data indicate metabolic activation and increased lipid metabolism in ATMs upon forming CLS. Most importantly, adipocyte death, even in lean animals under homeostatic conditions, leads to a locally confined inflammation, which is in sharp contrast to other tissues. We identified cell size as cause for the described pro-inflammatory response, as the size of adipocytes is above a critical threshold size for efferocytosis, a process for anti-inflammatory removal of dead cells during tissue homeostasis. Finally, experiments on parabiotic mice verified that adipocyte death leads to a pro-inflammatory response of resident ATMs in vivo, without significant recruitment of blood monocytes. Our data indicate that adipocyte death triggers a unique degradation process and locally induces a metabolically activated ATM phenotype that is globally observed with obesity.
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11
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Brinker G, Froeba J, Arndt L, Braune J, Hobusch C, Lindhorst A, Bechmann I, Gericke M. CD4 + T cells regulate glucose homeostasis independent of adipose tissue dysfunction in mice. Eur J Immunol 2021; 51:1399-1411. [PMID: 33784418 DOI: 10.1002/eji.202048870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 02/10/2021] [Accepted: 03/16/2021] [Indexed: 11/11/2022]
Abstract
Obesity is frequently associated with a chronic low-grade inflammation in the adipose tissue (AT) and impaired glucose homeostasis. Adipose tissue macrophages (ATMs) have been shown to accumulate in the inflamed AT either by means of recruitment from the blood or local proliferation. ATM proliferation and activation can be stimulated by TH2 cytokines, such as IL-4 and IL-13, suggesting involvement of CD4-positive T cells in ATM proliferation and activation. Furthermore, several studies have associated T cells to alterations in glucose metabolism. Therefore, we sought to examine a direct impact of CD4-positive T cells on ATM activation, ATM proliferation and glucose homeostasis using an in vivo depletion model. Surprisingly, CD4 depletion did not affect ATM activation, ATM proliferation, or insulin sensitivity. However, CD4 depletion led to a significant improvement of glucose tolerance. In line with this, we found moderate disturbances in pancreatic endocrine function following CD4 depletion. Hence, our data suggest that the effect on glucose metabolism observed after CD4 depletion might be mediated by organs other than AT and independent of AT inflammation.
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Affiliation(s)
- Georg Brinker
- Institute of Anatomy, Leipzig University, Leipzig, D-04103, Germany
| | - Janine Froeba
- Institute of Anatomy, Leipzig University, Leipzig, D-04103, Germany.,Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), D-06108, Germany
| | - Lilli Arndt
- Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), D-06108, Germany
| | - Julia Braune
- Institute of Anatomy, Leipzig University, Leipzig, D-04103, Germany.,Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), D-06108, Germany
| | | | - Andreas Lindhorst
- Institute of Anatomy, Leipzig University, Leipzig, D-04103, Germany.,Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), D-06108, Germany
| | - Ingo Bechmann
- Institute of Anatomy, Leipzig University, Leipzig, D-04103, Germany
| | - Martin Gericke
- Institute of Anatomy, Leipzig University, Leipzig, D-04103, Germany.,Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), D-06108, Germany
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12
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Huang Q, Garrett A, Bose S, Blocker S, Rios AC, Clevers H, Shen X. The frontier of live tissue imaging across space and time. Cell Stem Cell 2021; 28:603-622. [PMID: 33798422 PMCID: PMC8034393 DOI: 10.1016/j.stem.2021.02.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
What you see is what you get-imaging techniques have long been essential for visualization and understanding of tissue development, homeostasis, and regeneration, which are driven by stem cell self-renewal and differentiation. Advances in molecular and tissue modeling techniques in the last decade are providing new imaging modalities to explore tissue heterogeneity and plasticity. Here we describe current state-of-the-art imaging modalities for tissue research at multiple scales, with a focus on explaining key tradeoffs such as spatial resolution, penetration depth, capture time/frequency, and moieties. We explore emerging tissue modeling and molecular tools that improve resolution, specificity, and throughput.
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Affiliation(s)
- Qiang Huang
- Department of Pediatric Surgery, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004 Shaanxi, China; Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Aliesha Garrett
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Shree Bose
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Stephanie Blocker
- Center for In Vitro Microscopy, Duke University, Durham, NC 27708, USA
| | - Anne C Rios
- Princess Máxima Center for Pediatric Oncology, Utrecht 3584, the Netherlands; Department of Cancer Research, Oncode Institute, Hubrecht Institute-KNAW Utrecht, Utrecht 3584, the Netherlands
| | - Hans Clevers
- Princess Máxima Center for Pediatric Oncology, Utrecht 3584, the Netherlands; Department of Cancer Research, Oncode Institute, Hubrecht Institute-KNAW Utrecht, Utrecht 3584, the Netherlands; Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center (UMC) Utrecht, Utrecht 3584, the Netherlands
| | - Xiling Shen
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA.
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13
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Braune J, Lindhorst A, Fröba J, Hobusch C, Kovacs P, Blüher M, Eilers J, Bechmann I, Gericke M. Multinucleated Giant Cells in Adipose Tissue Are Specialized in Adipocyte Degradation. Diabetes 2021; 70:538-548. [PMID: 33158932 DOI: 10.2337/db20-0293] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 10/30/2020] [Indexed: 11/13/2022]
Abstract
Obesity is associated with chronic low-grade inflammation of visceral adipose tissue (AT) characterized by an increasing number of AT macrophages (ATMs) and linked to type 2 diabetes. AT inflammation is histologically indicated by the formation of so-called crown-like structures, as ATMs accumulate around dying adipocytes, and the occurrence of multinucleated giant cells (MGCs). However, to date, the function of MGCs in obesity is unknown. Therefore, the aim of this study was to characterize MGCs in AT and unravel the function of these cells. We demonstrated that MGCs occurred in obese patients and after 24 weeks of a high-fat diet in mice, accompanying signs of AT inflammation and then representing ∼3% of ATMs in mice. Mechanistically, we found evidence that adipocyte death triggered MGC formation. Most importantly, MGCs in obese AT had a higher capacity to phagocytize oversized particles, such as adipocytes, as shown by live imaging of AT, 45-µm bead uptake ex vivo, and higher lipid content in vivo. Finally, we showed that interleukin-4 treatment was sufficient to increase the number of MGCs in AT, whereas other factors may be more important for endogenous MGC formation in vivo. Most importantly, our data suggest that MGCs are specialized for clearance of dead adipocytes in obesity.
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Affiliation(s)
- Julia Braune
- Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Andreas Lindhorst
- Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle, Germany
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| | - Janine Fröba
- Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle, Germany
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| | | | - Peter Kovacs
- Medical Department III, Leipzig University, Leipzig, Germany
| | - Matthias Blüher
- Medical Department III, Leipzig University, Leipzig, Germany
| | - Jens Eilers
- Carl-Ludwig Institute of Physiology, Leipzig University, Leipzig, Germany
| | - Ingo Bechmann
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| | - Martin Gericke
- Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle, Germany
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14
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Lindhorst A, Bechmann I, Gericke M. Unspecific DNA recombination in AdipoqCre-ER T2 - mediated knockout approaches in transgenic mice is sex-, age- and genotype-dependent. Adipocyte 2020; 9:1-6. [PMID: 31842670 PMCID: PMC6959310 DOI: 10.1080/21623945.2019.1701394] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Due to the epidemic rise of obesity prevalence, adipose tissue (AT) research is of major interest. Our aim was to study specificity of the most-common Cre/loxP approach for inducible gene manipulation of AT in mice (AdipoqCre-ERT2). We used mice with tamoxifen-sensitive Cre recombinase controlled by the adiponectin promoter (AdipoqCre-ERT2), which were crossed to a tdTomato reporter mouse to visualize the site of recombination on a single-cell resolution. Albeit tamoxifen induced tdTomato expression in this model, also non-stimulated background recombination (‘Cre leakage’) was detected in AT of untreated Adipoq-CreERT2xTDTO mice in vivo. Quantification of Cre leakage revealed age, sex and genotype as factors impacting on non-induced Cre recombination.
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Affiliation(s)
- Andreas Lindhorst
- Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
- Institute of Anatomy, Leipzig University, Leipzig, Germany
| | - Ingo Bechmann
- Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Martin Gericke
- Institute of Anatomy and Cell Biology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
- Institute of Anatomy, Leipzig University, Leipzig, Germany
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15
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Schopow N, Kallendrusch S, Gong S, Rapp F, Körfer J, Gericke M, Spindler N, Josten C, Langer S, Bechmann I. Examination of ex-vivo viability of human adipose tissue slice culture. PLoS One 2020; 15:e0233152. [PMID: 32453755 PMCID: PMC7250419 DOI: 10.1371/journal.pone.0233152] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 04/29/2020] [Indexed: 01/29/2023] Open
Abstract
Obesity is associated with significantly higher mortality rates, and excess adipose tissue is involved in respective pathologies. Here we established a human adipose tissue slice cultures (HATSC) model ex vivo. HATSC match the in vivo cell composition of human adipose tissue with, among others, mature adipocytes, mesenchymal stem cells as well as stroma tissue and immune cells. This is a new method, optimized for live imaging, to study adipose tissue and cell-based mechanisms of obesity in particular. HATSC survival was tested by means of conventional and immunofluorescence histological techniques, functional analyses and live imaging. Surgery-derived tissue was cut with a tissue chopper in 500 μm sections and transferred onto membranes building an air-liquid interface. HATSC were cultured in six-well plates filled with Dulbecco’s Modified Eagle’s Medium (DMEM), insulin, transferrin, and selenium, both with and without serum. After 0, 1, 7 and 14 days in vitro, slices were fixated and analyzed by morphology and Perilipin A for tissue viability. Immunofluorescent staining against IBA1, CD68 and Ki67 was performed to determine macrophage survival and proliferation. These experiments showed preservation of adipose tissue as well as survival and proliferation of monocytes and stroma tissue for at least 14 days in vitro even in the absence of serum. The physiological capabilities of adipocytes were functionally tested by insulin stimulation and measurement of Phospho-Akt on day 7 and 14 in vitro. Viability was further confirmed by live imaging using Calcein-AM (viable cells) and propidium iodide (apoptosis/necrosis). In conclusion, HATSC have been successfully established by preserving the monovacuolar form of adipocytes and surrounding macrophages and connective tissue. This model allows further analysis of mature human adipose tissue biology ex vivo.
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Affiliation(s)
- Nikolas Schopow
- Institute of Anatomy, University Leipzig, Leipzig, Germany
- Department for Orthopedics, Trauma Surgery, and Reconstructive Surgery, University Hospital Leipzig, Leipzig, Germany
- * E-mail:
| | | | - Siming Gong
- Institute of Anatomy, University Leipzig, Leipzig, Germany
- Department for Orthopedics, Trauma Surgery, and Reconstructive Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Felicitas Rapp
- Institute of Anatomy, University Leipzig, Leipzig, Germany
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany
| | - Justus Körfer
- Institute of Anatomy, University Leipzig, Leipzig, Germany
- University Cancer Center Leipzig (UCCL), University Hospital Leipzig, Leipzig, Germany
| | - Martin Gericke
- Institute of Anatomy, University Leipzig, Leipzig, Germany
| | - Nick Spindler
- Department for Orthopedics, Trauma Surgery, and Reconstructive Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Christoph Josten
- Department for Orthopedics, Trauma Surgery, and Reconstructive Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Stefan Langer
- Department for Orthopedics, Trauma Surgery, and Reconstructive Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Ingo Bechmann
- Institute of Anatomy, University Leipzig, Leipzig, Germany
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16
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Castegna A, Gissi R, Menga A, Montopoli M, Favia M, Viola A, Canton M. Pharmacological targets of metabolism in disease: Opportunities from macrophages. Pharmacol Ther 2020; 210:107521. [PMID: 32151665 DOI: 10.1016/j.pharmthera.2020.107521] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/28/2020] [Indexed: 12/12/2022]
Abstract
From advances in the knowledge of the immune system, it is emerging that the specialized functions displayed by macrophages during the course of an immune response are supported by specific and dynamically-connected metabolic programs. The study of immunometabolism is demonstrating that metabolic adaptations play a critical role in modulating inflammation and, conversely, inflammation deeply influences the acquisition of specific metabolic settings.This strict connection has been proven to be crucial for the execution of defined immune functional programs and it is now under investigation with respect to several human disorders, such as diabetes, sepsis, cancer, and autoimmunity. The abnormal remodelling of the metabolic pathways in macrophages is now emerging as both marker of disease and potential target of therapeutic intervention. By focusing on key pathological conditions, namely obesity and diabetes, rheumatoid arthritis, atherosclerosis and cancer, we will review the metabolic targets suitable for therapeutic intervention in macrophages. In addition, we will discuss the major obstacles and challenges related to the development of therapeutic strategies for a pharmacological targeting of macrophage's metabolism.
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Affiliation(s)
- Alessandra Castegna
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy; IBIOM-CNR, Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, National Research Council, Bari, Italy; Fondazione Città della Speranza, Istituto di Ricerca Pediatrica, Padua, Italy.
| | - Rosanna Gissi
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Alessio Menga
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy; Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Monica Montopoli
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy; Veneto Institute of Molecular Medicine (VIMM), Padua, Italy
| | - Maria Favia
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Antonella Viola
- Department of Biomedical Sciences, University of Padua, Italy; Fondazione Città della Speranza, Istituto di Ricerca Pediatrica, Padua, Italy
| | - Marcella Canton
- Department of Biomedical Sciences, University of Padua, Italy; Fondazione Città della Speranza, Istituto di Ricerca Pediatrica, Padua, Italy.
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17
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Savaş EM, Oğuz SH, Samadi A, Yılmaz Işıkhan S, Ünlütürk U, Lay İ, Gürlek A. Apoptosis Inhibitor of Macrophage, Monocyte Chemotactic Protein-1, and C-Reactive Protein Levels Are Increased in Patients with Metabolic Syndrome: A Pilot Study. Metab Syndr Relat Disord 2020; 18:197-205. [PMID: 32096694 DOI: 10.1089/met.2019.0074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Background: Apoptosis inhibitor of macrophage (AIM) and monocyte chemotactic protein-1 (MCP-1) are molecules that cause migration of M1 macrophages to visceral adipocytes, which is the first step in development of metabolic syndrome. The aim of this study is to evaluate the status of AIM and MCP-1 in metabolic syndrome and to investigate their use as biomarkers. Methods: Forty metabolic syndrome patients and 40 healthy individuals were enrolled in the study. Serum AIM, MCP-1, and C-reactive protein (CRP) levels were measured by enzyme-linked immunosorbent assay. Results: AIM, MCP-1, and CRP levels were significantly higher in the metabolic syndrome group (P < 0.01, P < 0.01, and P < 0.05, respectively). There was a positive correlation of serum AIM, MCP-1, and CRP levels with waist circumference (r = 0.480, r = 0.663, and r = 0.418, respectively; P < 0.01). Receiver operating characteristic (ROC) curve analyses revealed AIM, MCP-1, and CRP cutoff points as 2383.7 ng/mL, 172.8 pg/mL, and 0.366 mg/dL, which could be used in the diagnosis of metabolic syndrome with highest sensitivity and specificity. In the logistic regression model, including age, AIM, CRP, and MCP-1 as covariates, having serum AIM and CRP levels above cutoffs were significant independent predictors for metabolic syndrome (odds ratios 13.8 and 21.3), whereas the serum MCP-1 level was not a significant independent predictor, although the odds ratio was 2.6 (P = 0.193). Conclusions: These results suggest that AIM and MCP-1 may play a role in the pathogenesis of metabolic syndrome. AIM and CRP levels may be used as biomarkers in the diagnosis of metabolic syndrome. Although MCP-1 is not an independent predictor, its elevation in metabolic syndrome is noteworthy, which warrants further analyses in larger groups.
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Affiliation(s)
- Emine Merve Savaş
- Department of Internal Medicine, Hacettepe University School of Medicine, Ankara, Turkey
| | - Seda Hanife Oğuz
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Hacettepe University School of Medicine, Ankara, Turkey
| | - Afshin Samadi
- Department of Medical Biochemistry, Hacettepe University School of Medicine, Ankara, Turkey
| | - Selen Yılmaz Işıkhan
- Department of Biostatistics, Hacettepe University School of Medicine, Ankara, Turkey
| | - Uğur Ünlütürk
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Hacettepe University School of Medicine, Ankara, Turkey
| | - İncilay Lay
- Department of Medical Biochemistry, Hacettepe University School of Medicine, Ankara, Turkey
| | - Alper Gürlek
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Hacettepe University School of Medicine, Ankara, Turkey
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18
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Burnett DD, Legako JF, Phelps KJ, Gonzalez JM. Biology, strategies, and fresh meat consequences of manipulating the fatty acid composition of meat. J Anim Sci 2020; 98:skaa033. [PMID: 31999826 PMCID: PMC7036598 DOI: 10.1093/jas/skaa033] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 01/28/2020] [Indexed: 12/20/2022] Open
Abstract
The utility and attractiveness of adipose tissue within meat products vary based on species, cut, and consumer preference. In beef, producers are rewarded for producing carcasses with greater visual marbling at the 12th and 13th rib juncture, while pork producers are either not rewarded or penalized for producing carcasses with too much adipose tissue. Some consumers prefer to purchase leaner meat cuts, while other consumers pay premiums to consume products with elevated fat content. While no clear consumer adipose tissue preference standard exists, advances in beef and swine nutrition have enabled producers to target markets that enable them to maximize profits. One niche market that has increased in popularity over the last decade is manipulating the fatty acid profile, specifically increasing omega-3 fatty acid content, of beef and pork products to increase their appeal in a healthy diet. While much research has documented the ability of preharvest diet to alter the fatty acid profile of beef and pork, the same studies have indicated both the color and palatability of these products were negatively affected if preharvest diets were not managed properly. The following review discusses the biology of adipose tissue and lipid accumulation, altering the omega-3 fatty acid profile of beef and pork, negative fresh meat color and palatability associated with these studies, and strategies to mitigate the negative effects of increased omega-3 fatty acid content.
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Affiliation(s)
- Derris D Burnett
- Department of Animal and Dairy Sciences, Mississippi State University, Starkville
| | - Jerrad F Legako
- Department of Animal and Food Sciences, Texas Tech University, Lubbock
| | | | - John M Gonzalez
- Department of Animal and Dairy Science, University of Georgia, Athens
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19
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Kim EY, Noh HM, Choi B, Park JE, Kim JE, Jang Y, Lee HK, Chang EJ. Interleukin-22 Induces the Infiltration of Visceral Fat Tissue by a Discrete Subset of Duffy Antigen Receptor for Chemokine-Positive M2-Like Macrophages in Response to a High Fat Diet. Cells 2019; 8:E1587. [PMID: 31817755 PMCID: PMC6953014 DOI: 10.3390/cells8121587] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/03/2019] [Accepted: 12/05/2019] [Indexed: 12/14/2022] Open
Abstract
Interleukin-22 (IL-22) is a cytokine with important functions in host defense and inflammatory responses and has recently been suggested to play a role in immune-inflammatory system in the context of obesity and its metabolic consequences. The specific cellular targets and mechanisms of IL-22-mediated obesity are largely unknown however. We here identified a previously unknown subset of monocyte-derived Duffy antigen receptors for chemokines (DARC)+ macrophages in epididymal fat adipose tissue and found that they are preferentially recruited into the crown-like structures of adipose tissue in the mouse upon high fat diet-induced obesity. Importantly, DARC+ macrophages highly express the IL-22 receptor (IL-22Ra1). Exposure to recombinant IL-22 shifts macrophages to an alternative M2 polarization pathway and augments DARC expression via a STAT5b signaling axis. STAT5b directly binds to the DARC promoter and a STAT5 inhibitor abrogates the IL-22-mediated induction of DARC. These M2-like DARC+ subpopulations of monocytes/macrophages were elevated in obese db/db mice compared to WT lean mice. Furthermore, subsets of CD14+ and/or CD16+ monocytes/macrophages within human peripheral blood mononuclear cell populations express DARC and the prevalence of these subsets is enhanced by IL-22 stimuli. This suggested that IL-22 is a critical cytokine that promotes the infiltration of adipose tissue macrophages, that regulate inflammatory processes. Taken together, our present findings provide important insights into the molecular mechanism by which IL-22 signal modulates DARC expression in M2-like macrophages.
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Affiliation(s)
- Eun-Young Kim
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (E.-Y.K.); (B.C.); (J.-E.P.); (J.-E.K.); (Y.J.)
- Stem Cell Immunomodulation Research Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Hye Mi Noh
- Department of Ophthalmology, Institute of Vision Research, Yonsei University College of Medicine, Seoul 06273, Korea;
| | - Bongkun Choi
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (E.-Y.K.); (B.C.); (J.-E.P.); (J.-E.K.); (Y.J.)
- Stem Cell Immunomodulation Research Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Ji-Eun Park
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (E.-Y.K.); (B.C.); (J.-E.P.); (J.-E.K.); (Y.J.)
- Stem Cell Immunomodulation Research Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Ji-Eun Kim
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (E.-Y.K.); (B.C.); (J.-E.P.); (J.-E.K.); (Y.J.)
- Stem Cell Immunomodulation Research Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Youngsaeng Jang
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (E.-Y.K.); (B.C.); (J.-E.P.); (J.-E.K.); (Y.J.)
| | - Hyung Keun Lee
- Department of Ophthalmology, Institute of Vision Research, Yonsei University College of Medicine, Seoul 06273, Korea;
- Department of Pharmacy, Integrated Science and Engineering Division, Yonsei University, Incheon 21983, Korea
| | - Eun-Ju Chang
- Department of Biomedical Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea; (E.-Y.K.); (B.C.); (J.-E.P.); (J.-E.K.); (Y.J.)
- Stem Cell Immunomodulation Research Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
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20
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Wang Y, Lee MYK, Mak JCW, Ip MSM. Low-Frequency Intermittent Hypoxia Suppresses Subcutaneous Adipogenesis and Induces Macrophage Polarization in Lean Mice. Diabetes Metab J 2019; 43:659-674. [PMID: 31237128 PMCID: PMC6834831 DOI: 10.4093/dmj.2018.0196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 12/06/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The relationship between obstructive sleep apnoea (OSA) and metabolic disorders is complex and highly associated. The impairment of adipogenic capacity in pre-adipocytes may promote adipocyte hypertrophy and increase the risk of further metabolic dysfunction. We hypothesize that intermittent hypoxia (IH), as a pathophysiologic feature of OSA, may regulate adipogenesis by promoting macrophage polarization. METHODS Male C57BL/6N mice were exposed to either IH (240 seconds of 10% O₂ followed by 120 seconds of 21% O₂, i.e., 10 cycles/hour) or intermittent normoxia (IN) for 6 weeks. Stromal-vascular fractions derived from subcutaneous (SUB-SVF) and visceral (VIS-SVF) adipose tissues were cultured and differentiated. Conditioned media from cultured RAW 264.7 macrophages after air (Raw) or IH exposure (Raw-IH) were incubated with SUB-SVF during adipogenic differentiation. RESULTS Adipogenic differentiation of SUB-SVF but not VIS-SVF from IH-exposed mice was significantly downregulated in comparison with that derived from IN-exposed mice. IH-exposed mice compared to IN-exposed mice showed induction of hypertrophic adipocytes and increased preferential infiltration of M1 macrophages in subcutaneous adipose tissue (SAT) compared to visceral adipose tissue. Complementary in vitro analysis demonstrated that Raw-IH media significantly enhanced inhibition of adipogenesis of SUB-SVF compared to Raw media, in agreement with corresponding gene expression levels of differentiation-associated markers and adipogenic transcription factors. CONCLUSION Low frequency IH exposure impaired adipogenesis of SAT in lean mice, and macrophage polarization may be a potential mechanism for the impaired adipogenesis.
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Affiliation(s)
- Yan Wang
- Department of Medicine, The University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong
- Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Mary Yuk Kwan Lee
- Department of Medicine, The University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong
- Research Centre of Heart, Brain, Hormone and Healthy Aging, The University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong
| | - Judith Choi Wo Mak
- Department of Medicine, The University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong
- Research Centre of Heart, Brain, Hormone and Healthy Aging, The University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong
- Department of Pharmacology & Pharmacy, The University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong
| | - Mary Sau Man Ip
- Department of Medicine, The University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong
- Research Centre of Heart, Brain, Hormone and Healthy Aging, The University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong.
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21
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Russo L, Lumeng CN. Properties and functions of adipose tissue macrophages in obesity. Immunology 2018; 155:407-417. [PMID: 30229891 DOI: 10.1111/imm.13002] [Citation(s) in RCA: 378] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 12/12/2022] Open
Abstract
The expansion of adipose tissue (AT) in obesity is accompanied by the accumulation of immune cells that contribute to a state of low-grade, chronic inflammation and dysregulated metabolism. Adipose tissue macrophages (ATMs) represent the most abundant class of leukocytes in AT and are involved in the regulation of several regulatory physiological processes, such as tissue remodeling and insulin sensitivity. With progressive obesity, ATMs are key mediators of meta-inflammation, insulin resistance and impairment of adipocyte function. While macrophage recruitment from blood monocytes is a critical component of the generation of AT inflammation, new studies have revealed a role for ATM proliferation in the early stages of obesity and in sustaining AT inflammation. In addition, studies have revealed a more complex range of macrophage activation states than the previous M1/M2 model, and the existence of different macrophage profiles between human and animal models. This review will summarize the current understanding of the regulatory mechanisms of ATM function in relation to obesity, type 2 diabetes, depot of origin, and to other leukocytes such as AT dendritic cells, with hopes of emphasizing the regulatory nodes that can potentially be targeted to prevent and treat obesity-related metabolic disorders.
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Affiliation(s)
- Lucia Russo
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Carey N Lumeng
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, USA.,Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
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22
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Appari M, Channon KM, McNeill E. Metabolic Regulation of Adipose Tissue Macrophage Function in Obesity and Diabetes. Antioxid Redox Signal 2018; 29:297-312. [PMID: 28661198 PMCID: PMC6012981 DOI: 10.1089/ars.2017.7060] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
SIGNIFICANCE Obesity and diabetes are associated with chronic activation of inflammatory pathways that are important mechanistic links between insulin resistance (IR), type 2 diabetes (T2D), and cardiovascular disease pathogenesis. The development of these metabolic diseases is associated with changes in both the number and phenotype of adipose tissue macrophages (ATMs). Emerging lines of evidence have shown that ATMs release proinflammatory cytokines similar to classically activated M1 macrophages, which directly contribute to IR or T2D. In contrast, adipose tissue (AT) from lean healthy individuals contains macrophages with a less inflammatory M2 phenotype. Recent Advances: Recent research has shown that macrophage phenotype is linked to profound changes in macrophage cellular metabolism. CRITICAL ISSUES This review focuses on the role of macrophages in AT inflammation and obesity, and the metabolic changes in macrophage function that occur with activation that underpin their role in the pathogenesis of IR and T2D. We highlight current targets for altering macrophage metabolism from both within the field of metabolic disease and AT biology and more widely within inflammatory biology. FUTURE DIRECTIONS As our knowledge of macrophage metabolic programming in AT builds, there will be increasing scope for targeting this aspect of macrophage biology as a therapeutic strategy in metabolic diseases. Antioxid. Redox Signal. 29, 297-312.
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Affiliation(s)
- Mahesh Appari
- 1 Division of Cardiovascular Medicine, British Heart Foundation Centre for Research Excellence, John Radcliffe Hospital, University of Oxford , Oxford, United Kingdom .,2 Wellcome Trust Centre for Human Genetics, University of Oxford , Oxford, United Kingdom
| | - Keith M Channon
- 1 Division of Cardiovascular Medicine, British Heart Foundation Centre for Research Excellence, John Radcliffe Hospital, University of Oxford , Oxford, United Kingdom .,2 Wellcome Trust Centre for Human Genetics, University of Oxford , Oxford, United Kingdom
| | - Eileen McNeill
- 1 Division of Cardiovascular Medicine, British Heart Foundation Centre for Research Excellence, John Radcliffe Hospital, University of Oxford , Oxford, United Kingdom .,2 Wellcome Trust Centre for Human Genetics, University of Oxford , Oxford, United Kingdom
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23
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Li Y, Liu TM. Discovering Macrophage Functions Using In Vivo Optical Imaging Techniques. Front Immunol 2018; 9:502. [PMID: 29599778 PMCID: PMC5863475 DOI: 10.3389/fimmu.2018.00502] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 02/26/2018] [Indexed: 12/27/2022] Open
Abstract
Macrophages are an important component of host defense and inflammation and play a pivotal role in immune regulation, tissue remodeling, and metabolic regulation. Since macrophages are ubiquitous in human bodies and have versatile physiological functions, they are involved in virtually every disease, including cancer, diabetes, multiple sclerosis, and atherosclerosis. Molecular biological and histological methods have provided critical information on macrophage biology. However, many in vivo dynamic behaviors of macrophages are poorly understood and yet to be discovered. A better understanding of macrophage functions and dynamics in pathogenesis will open new opportunities for better diagnosis, prognostic assessment, and therapeutic intervention. In this article, we will review the advances in macrophage tracking and analysis with in vivo optical imaging in the context of different diseases. Moreover, this review will cover the challenges and solutions for optical imaging techniques during macrophage intravital imaging.
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Affiliation(s)
- Yue Li
- Faculty of Health Sciences, University of Macau, Macao, China
| | - Tzu-Ming Liu
- Faculty of Health Sciences, University of Macau, Macao, China
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Han SJ, Glatman Zaretsky A, Andrade-Oliveira V, Collins N, Dzutsev A, Shaik J, Morais da Fonseca D, Harrison OJ, Tamoutounour S, Byrd AL, Smelkinson M, Bouladoux N, Bliska JB, Brenchley JM, Brodsky IE, Belkaid Y. White Adipose Tissue Is a Reservoir for Memory T Cells and Promotes Protective Memory Responses to Infection. Immunity 2017; 47:1154-1168.e6. [PMID: 29221731 DOI: 10.1016/j.immuni.2017.11.009] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 09/13/2017] [Accepted: 11/06/2017] [Indexed: 12/21/2022]
Abstract
White adipose tissue bridges body organs and plays a fundamental role in host metabolism. To what extent adipose tissue also contributes to immune surveillance and long-term protective defense remains largely unknown. Here, we have shown that at steady state, white adipose tissue contained abundant memory lymphocyte populations. After infection, white adipose tissue accumulated large numbers of pathogen-specific memory T cells, including tissue-resident cells. Memory T cells in white adipose tissue expressed a distinct metabolic profile, and white adipose tissue from previously infected mice was sufficient to protect uninfected mice from lethal pathogen challenge. Induction of recall responses within white adipose tissue was associated with the collapse of lipid metabolism in favor of antimicrobial responses. Our results suggest that white adipose tissue represents a memory T cell reservoir that provides potent and rapid effector memory responses, positioning this compartment as a potential major contributor to immunological memory.
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Affiliation(s)
- Seong-Ji Han
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Arielle Glatman Zaretsky
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Vinicius Andrade-Oliveira
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Nicholas Collins
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Amiran Dzutsev
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Jahangheer Shaik
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Denise Morais da Fonseca
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Oliver J Harrison
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Samira Tamoutounour
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Allyson L Byrd
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA; Translational and Functional Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA; Department of Bioinformatics, Boston University, Boston, MA 02215, USA
| | - Margery Smelkinson
- Biological Imaging, Research Technology Branch, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Nicolas Bouladoux
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA; NIAID Microbiome Program, NIH, Bethesda, MD 20892, USA
| | - James B Bliska
- Department of Molecular Genetics and Microbiology, 238 Centers for Molecular Medicine, Stony Brook University, Stonybrook, NY 11794, USA
| | - Jason M Brenchley
- Barrier Immunity Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Igor E Brodsky
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yasmine Belkaid
- Mucosal Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA; NIAID Microbiome Program, NIH, Bethesda, MD 20892, USA.
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Okamatsu-Ogura Y, Nio-Kobayashi J, Nagaya K, Tsubota A, Kimura K. Brown adipocytes postnatally arise through both differentiation from progenitors and conversion from white adipocytes in Syrian hamster. J Appl Physiol (1985) 2017; 124:99-108. [PMID: 28982944 DOI: 10.1152/japplphysiol.00622.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To investigate the postnatal development of brown adipose tissue (BAT) in Syrian hamsters, we histologically examined interscapular fat tissue from 5-16-day-old pups, focusing on how brown adipocytes arise. Interscapular fat of 5-day-old hamsters mainly consisted of white adipocytes containing large unilocular lipid droplets, as observed in typical white adipose tissue (WAT). On day 7, clusters of small, proliferative nonadipocytes with a strong immunoreactivity for Ki67 appeared near the edge of the interscapular fat tissue. The area of the Ki67-positive regions expanded to ~50% of the total tissue area by day 10. The interscapular fat showed the typical BAT feature by day 16. A brown adipocyte-specific marker, uncoupling protein-1, was clearly detected on day 10 and thereafter, while not detected on day 7. During conversion of interscapular fat from WAT to BAT, unilocular adipocytes completely and rapidly disappeared without obvious apoptosis. Dual immunofluorescence staining for Ki67 and monocarboxylate transporter 1 (MCT1), another selective marker for brown adipocytes, revealed that most of the proliferating cells were of the brown adipocyte lineage. Electron microscopic examination showed that some of the white adipocytes contained small lipid droplets in addition to the large droplet and expressed MCT1 as do progenitor and mature brown adipocytes, implying a direct conversion from white to brown adipocytes. These results suggest that BAT of Syrian hamsters develops postnatally through two different pathways: the proliferation and differentiation of brown adipocyte progenitors and the conversion of unilocular adipocytes to multilocular brown adipocytes. NEW & NOTEWORTHY Brown and white adipose tissues (BAT and WAT, respectively) are quite different in morphological features and function; however, the boundary between these tissues is obscure. In this study, we histologically evaluated the process of BAT development in Syrian hamsters, which shows postnatal conversion of WAT to BAT. Our results suggest that brown adipocytes arise through two different pathways: the proliferation and differentiation of brown adipocyte progenitors and the conversion from white adipocytes.
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Affiliation(s)
- Yuko Okamatsu-Ogura
- Laboratory of Biochemistry, Division of Veterinary Medicine, Graduate School of Veterinary Medicine, Hokkaido University , Sapporo , Japan
| | - Junko Nio-Kobayashi
- Laboratory of Histology and Cytology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University , Sapporo , Japan
| | - Kazuki Nagaya
- Laboratory of Biochemistry, Division of Veterinary Medicine, Graduate School of Veterinary Medicine, Hokkaido University , Sapporo , Japan
| | - Ayumi Tsubota
- Laboratory of Biochemistry, Division of Veterinary Medicine, Graduate School of Veterinary Medicine, Hokkaido University , Sapporo , Japan
| | - Kazuhiro Kimura
- Laboratory of Biochemistry, Division of Veterinary Medicine, Graduate School of Veterinary Medicine, Hokkaido University , Sapporo , Japan
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Braune J, Weyer U, Matz-Soja M, Hobusch C, Kern M, Kunath A, Klöting N, Kralisch S, Blüher M, Gebhardt R, Zavros Y, Bechmann I, Gericke M. Hedgehog signalling in myeloid cells impacts on body weight, adipose tissue inflammation and glucose metabolism. Diabetologia 2017; 60:889-899. [PMID: 28233033 DOI: 10.1007/s00125-017-4223-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 01/23/2017] [Indexed: 12/21/2022]
Abstract
AIMS/HYPOTHESIS Recently, hedgehog (Hh) was identified as a crucial player in adipose tissue development and energy expenditure. Therefore, we tested whether Hh ligands are regulated in obesity. Further, we aimed at identifying potential target cells of Hh signalling and studied the functional impact of Hh signalling on adipose tissue inflammation and glucose metabolism. METHODS Hh ligands and receptors were analysed in adipose tissue or serum from lean and obese mice as well as in humans. To study the impact on adipose tissue inflammation and glucose metabolism, Hh signalling was specifically blocked in myeloid cells using a conditional knockout approach (Lys-Smo -/-). RESULTS Desert Hh (DHH) and Indian Hh (IHH) are local Hh ligands, whereas Sonic Hh is not expressed in adipose tissue from mice or humans. In mice, obesity leads to a preferential upregulation of Hh ligands (Dhh) and signalling components (Ptch1, Smo and Gli1) in subcutaneous adipose tissue. Further, adipose tissue macrophages are Hh target cells owing to the expression of Hh receptors, such as Patched1 and 2. Conditional knockout of Smo (which encodes Smoothened, a mandatory Hh signalling component) in myeloid cells increases body weight and adipose tissue inflammation and attenuates glucose tolerance, suggesting an anti-inflammatory effect of Hh signalling. In humans, adipose tissue expression of DHH and serum IHH decrease with obesity and type 2 diabetes, which might be explained by the intake of metformin. Interestingly, metformin reduced Dhh and Ihh expression in mouse adipose tissue explants. CONCLUSIONS/INTERPRETATION Hh signalling in myeloid cells affects adipose tissue inflammation and glucose metabolism and may be a potential target to treat type 2 diabetes.
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Affiliation(s)
- Julia Braune
- Institute of Anatomy, Leipzig University, Oststrasse 25, D-04317, Leipzig, Germany
| | - Ulrike Weyer
- Institute of Anatomy, Leipzig University, Oststrasse 25, D-04317, Leipzig, Germany
| | - Madlen Matz-Soja
- Institute of Biochemistry, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Constance Hobusch
- Institute of Anatomy, Leipzig University, Oststrasse 25, D-04317, Leipzig, Germany
| | - Matthias Kern
- German Center of Diabetes Research (DZD), Leipzig, Germany
| | - Anne Kunath
- IFB Adiposity Disease, Core Unit, Leipzig University, Leipzig, Germany
| | - Nora Klöting
- IFB Adiposity Disease, Core Unit, Leipzig University, Leipzig, Germany
| | - Susann Kralisch
- Department of Medicine, Leipzig University, Leipzig, Germany
| | - Matthias Blüher
- Department of Medicine, Leipzig University, Leipzig, Germany
| | - Rolf Gebhardt
- Institute of Biochemistry, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Yana Zavros
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, USA
| | - Ingo Bechmann
- Institute of Anatomy, Leipzig University, Oststrasse 25, D-04317, Leipzig, Germany
| | - Martin Gericke
- Institute of Anatomy, Leipzig University, Oststrasse 25, D-04317, Leipzig, Germany.
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Braune J, Weyer U, Hobusch C, Mauer J, Brüning JC, Bechmann I, Gericke M. IL-6 Regulates M2 Polarization and Local Proliferation of Adipose Tissue Macrophages in Obesity. THE JOURNAL OF IMMUNOLOGY 2017; 198:2927-2934. [PMID: 28193830 DOI: 10.4049/jimmunol.1600476] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 01/20/2017] [Indexed: 12/12/2022]
Abstract
Obesity is associated with chronic low-grade inflammation of adipose tissue (AT) and an increase of AT macrophages (ATMs) that is linked to the onset of type 2 diabetes. We have recently shown that focal sites of inflammation around dying adipocytes, so-called crown-like structures, exhibit a unique microenvironment for macrophage proliferation. Interestingly, locally proliferating macrophages were not classically activated (M1), but they exhibited a rather alternatively activated (M2) immune phenotype. In this study, we established organotypic cell cultures of AT explants to study the impact of cytokine treatment on local ATM proliferation, without the bias of early monocyte recruitment. We show that exposure of AT to Th2 cytokines, such as IL-4, IL-13, and GM-CSF, stimulates ATM proliferation, whereas Th1 cytokines, such as TNF-α, inhibit local ATM proliferation. Furthermore, AT from obese mice exhibits an increased sensitivity to IL-4 stimulation, indicated by an increased phosphorylation of STAT6. In line with this, gene expression of the IL-4 receptor (Il4ra) and its ligand IL-13 are elevated in AT of obese C57BL/6 mice. Most importantly, Il4ra expression and susceptibility to IL-4 or IL-13 treatment depend on IL-6 signaling, which seems to be the underlying mechanism of local ATM proliferation in obesity. We conclude that IL-6 acts as a Th2 cytokine in obesity by stimulating M2 polarization and local ATM proliferation, presumably due to upregulation of the IL-4 receptor α.
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Affiliation(s)
- Julia Braune
- Institute of Anatomy, Leipzig University, 04317 Leipzig, Germany
| | - Ulrike Weyer
- Institute of Anatomy, Leipzig University, 04317 Leipzig, Germany
| | | | - Jan Mauer
- Department of Pharmacology, Weill Cornell Medical College, Cornell University, New York, NY 10065; and
| | - Jens C Brüning
- Max Planck Institute for Metabolism Research, 50931 Cologne, Germany
| | - Ingo Bechmann
- Institute of Anatomy, Leipzig University, 04317 Leipzig, Germany
| | - Martin Gericke
- Institute of Anatomy, Leipzig University, 04317 Leipzig, Germany;
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Abstract
Inflammation originating from the adipose tissue is considered to be one of the main driving forces for the development of insulin resistance and type 2 diabetes in obese individuals. Although a plethora of different immune cells shapes adipose tissue inflammation, this review is specifically focused on the contribution of macrophages that reside in adipose tissue in lean and obese conditions. Both conventional and tissue-specific functions of adipose tissue macrophages (ATMs) in lean and obese adipose tissue are discussed and linked with metabolic and inflammatory changes that occur during the development of obesity. Furthermore, we will address various circulating and adipose tissue-derived triggers that may be involved in shaping the ATM phenotype and underlie ATM function in lean and obese conditions. Finally, we will highlight how these changes affect adipose tissue inflammation and may be targeted for therapeutic interventions to improve insulin sensitivity in obese individuals.
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Affiliation(s)
- Lily Boutens
- Department of Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
- Nutrition, Metabolism and Genomics Group, Wageningen University, Bomenweg 2, 6703 HD, Wageningen, the Netherlands
| | - Rinke Stienstra
- Department of Medicine, Radboud University Medical Center, Nijmegen, the Netherlands.
- Nutrition, Metabolism and Genomics Group, Wageningen University, Bomenweg 2, 6703 HD, Wageningen, the Netherlands.
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Hill AA, Anderson-Baucum EK, Kennedy AJ, Webb CD, Yull FE, Hasty AH. Activation of NF-κB drives the enhanced survival of adipose tissue macrophages in an obesogenic environment. Mol Metab 2015; 4:665-77. [PMID: 26779432 PMCID: PMC4588436 DOI: 10.1016/j.molmet.2015.07.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 07/10/2015] [Accepted: 07/18/2015] [Indexed: 01/09/2023] Open
Abstract
Objective Macrophage accumulation in adipose tissue (AT) during obesity contributes to inflammation and insulin resistance. Recruitment of monocytes to obese AT has been the most studied mechanism explaining this accumulation. However, recent evidence suggests that recruitment-independent mechanisms may also regulate pro-inflammatory AT macrophage (ATM) numbers. The role of increased ATM survival during obesity has yet to be explored. Results We demonstrate that activation of apoptotic pathways is significantly reduced in ATMs from diet-induced and genetically obese mice. Concurrently, pro-survival Bcl-2 family member protein levels and localization to the mitochondria is elevated in ATMs from obese mice. This increased pro-survival signaling was associated with elevated activation of the transcription factor, NF-κB, and increased expression of its pro-survival target genes. Finally, an obesogenic milieu increased ATM viability only when NF-κB signaling pathways were functional. Conclusions Our data demonstrate that obesity promotes survival of inflammatory ATMs, possibly through an NF-κB-regulated mechanism. Macrophage apoptosis is decreased in obese adipose tissue. ATMs from obese mice display increased mitochondrial localization of Bcl-2. The pro-survival targets of NF-κB are increased in ATMs from obese mice. NF-κB activation in ATMs during metabolic stimulation increases their survival. Decreased ATM apoptosis contributes to macrophage accumulation in obesity.
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Affiliation(s)
- Andrea A Hill
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, United States
| | - Emily K Anderson-Baucum
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, United States
| | - Arion J Kennedy
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, United States
| | - Corey D Webb
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, United States
| | - Fiona E Yull
- Department of Cancer Biology, Vanderbilt University School of Medicine, United States
| | - Alyssa H Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, United States; Department of Veterans Affairs, Tennessee Valley Healthcare System, United States
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