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Mancuso P, Curtis JL, Weitzel AM, Griffin CA, Bouchard B, Freeman CM, Bridges D, Singer K. Diet-induced obesity in mice impairs host defense against Klebsiella pneumonia in vivo and glucose transport and bactericidal functions in neutrophils in vitro. Am J Physiol Lung Cell Mol Physiol 2022; 322:L116-L128. [PMID: 34850640 PMCID: PMC8794018 DOI: 10.1152/ajplung.00008.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 11/16/2021] [Accepted: 11/16/2021] [Indexed: 01/03/2023] Open
Abstract
Obesity impairs host defense against Klebsiella pneumoniae, but responsible mechanisms are incompletely understood. To determine the impact of diet-induced obesity on pulmonary host defense against K. pneumoniae, we fed 6-wk-old male C57BL/6j mice a normal diet (ND) or high-fat diet (HFD) (13% vs. 60% fat, respectively) for 16 wk. Mice were intratracheally infected with Klebsiella, assayed at 24 or 48 h for bacterial colony-forming units, lung cytokines, and leukocytes from alveolar spaces, lung parenchyma, and gonadal adipose tissue were assessed using flow cytometry. Neutrophils from uninfected mice were cultured with and without 2-deoxy-d-glucose (2-DG) and assessed for phagocytosis, killing, reactive oxygen intermediates (ROI), transport of 2-DG, and glucose transporter (GLUT1-4) transcripts, and protein expression of GLUT1 and GLUT3. HFD mice had higher lung and splenic bacterial burdens. In HFD mice, baseline lung homogenate concentrations of IL-1β, IL-6, IL-17, IFN-γ, CXCL2, and TNF-α were reduced relative to ND mice, but following infection were greater for IL-6, CCL2, CXCL2, and IL-1β (24 h only). Despite equivalent lung homogenate leukocytes, HFD mice had fewer intraalveolar neutrophils. HFD neutrophils exhibited decreased Klebsiella phagocytosis and killing and reduced ROI to heat-killed Klebsiella in vitro. 2-DG transport was lower in HFD neutrophils, with reduced GLUT1 and GLUT3 transcripts and protein (GLUT3 only). Blocking glycolysis with 2-DG impaired bacterial killing and ROI production in neutrophils from mice fed ND but not HFD. Diet-induced obesity impairs pulmonary Klebsiella clearance and augments blood dissemination by reducing neutrophil killing and ROI due to impaired glucose transport.
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Affiliation(s)
- Peter Mancuso
- Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan
- Graduate Program in Immunology, University of Michigan, Ann Arbor, Michigan
| | - Jeffrey L Curtis
- Graduate Program in Immunology, University of Michigan, Ann Arbor, Michigan
- Division of Pulmonary & Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
- Medical Service, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan
| | - Anne M Weitzel
- Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Cameron A Griffin
- Division of Pediatric Endocrinology, Department of Pediatrics, University of Michigan, Ann Arbor, Michigan
| | - Benjamin Bouchard
- Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Christine M Freeman
- Graduate Program in Immunology, University of Michigan, Ann Arbor, Michigan
- Division of Pulmonary & Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
- Research Service, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan
| | - Dave Bridges
- Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Kanakadurga Singer
- Graduate Program in Immunology, University of Michigan, Ann Arbor, Michigan
- Division of Pediatric Endocrinology, Department of Pediatrics, University of Michigan, Ann Arbor, Michigan
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2
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Birlutiu V, Boicean LC. Serum leptin level as a diagnostic and prognostic marker in infectious diseases and sepsis: A comprehensive literature review. Medicine (Baltimore) 2021; 100:e25720. [PMID: 33907162 PMCID: PMC8084034 DOI: 10.1097/md.0000000000025720] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 02/27/2021] [Accepted: 04/11/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Infections and sepsis are common causes of morbidity and mortality, with an increasing incidence worldwide. Leptin is involved in the inflammatory process and may modulate the cytokine production, immune cell proliferation and endothelial function. There are conflicting results regarding alterations of leptin levels in infectious diseases and the outcome from sepsis.The aim of the current article is to provide an overview of the medical literature on the correlations between variations of leptin levels and infectious diseases and sepsis. METHODS We performed an extensive literature search in PubMed and Google Scholar databases, using keywords to identify articles related to leptin in infectious diseases and sepsis. Searches were referenced using medical subject headings that included "leptin," "adipokines," "sepsis," "infectious diseases," "leptin deficiency," "leptin resistance" or "hyperleptinemia." The language of publication, journal, or country were not included as limitation criteria.Articles or abstracts containing adequate information, such as age, sex, anthropometric indices, clinical presentation, comorbidities, and management were included in the study, whereas articles with insufficient clinical and demographic data were excluded. We assessed the quality of the studies selected.The final review of all databases was conducted on June 18, 2020. RESULTS We find the results from the current review to be of great importance due to the possible therapeutic role of leptin analogs in states of leptin deficiency associated with infectious diseases or sepsis.In hyperleptinemia, a therapeutic plan for obtaining leptin neutralization also needs further investigations. This could lead to the reduction of proinflammatory responses.There is a need for further studies to demonstrate the specificity and sensitivity of leptin in the early diagnosis of sepsis and the need to measure serum leptin levels in routine evaluation of the critical patient. CONCLUSION The multiple effects of leptin are of growing interest, but further studies are needed to elucidate the role of leptin signalling in infectious diseases and sepsis. Because very few human studies are reported, we recommend the need for further research.Better understanding of the pathophysiology of sepsis and the implication of circulating total leptin in this process could help physicians in managing this life-threatening condition.
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Affiliation(s)
- Victoria Birlutiu
- “Lucian Blaga” University of Sibiu, Faculty of Medicine
- Academic Emergency Hospital Sibiu—Infectious Diseases Clinic, Sibiu, Romania
| | - Loredana Camelia Boicean
- “Lucian Blaga” University of Sibiu, Faculty of Medicine
- Academic Emergency Hospital Sibiu—Infectious Diseases Clinic, Sibiu, Romania
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3
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Andrade FB, Gualberto A, Rezende C, Percegoni N, Gameiro J, Hottz ED. The Weight of Obesity in Immunity from Influenza to COVID-19. Front Cell Infect Microbiol 2021; 11:638852. [PMID: 33816341 PMCID: PMC8011498 DOI: 10.3389/fcimb.2021.638852] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/19/2021] [Indexed: 12/15/2022] Open
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged in December 2019 and rapidly outspread worldwide endangering human health. The coronavirus disease 2019 (COVID-19) manifests itself through a wide spectrum of symptoms that can evolve to severe presentations as pneumonia and several non-respiratory complications. Increased susceptibility to COVID-19 hospitalization and mortality have been linked to associated comorbidities as diabetes, hypertension, cardiovascular diseases and, recently, to obesity. Similarly, individuals living with obesity are at greater risk to develop clinical complications and to have poor prognosis in severe influenza pneumonia. Immune and metabolic dysfunctions associated with the increased susceptibility to influenza infection are linked to obesity-associated low-grade inflammation, compromised immune and endocrine systems, and to high cardiovascular risk. These preexisting conditions may favor virological persistence, amplify immunopathological responses and worsen hemodynamic instability in severe COVID-19 as well. In this review we highlight the main factors and the current state of the art on obesity as risk factor for influenza and COVID-19 hospitalization, severe respiratory manifestations, extrapulmonary complications and even death. Finally, immunoregulatory mechanisms of severe influenza pneumonia in individuals with obesity are addressed as likely factors involved in COVID-19 pathophysiology.
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Affiliation(s)
- Fernanda B. Andrade
- Laboratory of Immunothrombosis, Department of Biochemistry, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Ana Gualberto
- Laboratory of Immunology, Obesity and Infectious Diseases, Department of Parasitology, Microbiology and Immunology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Camila Rezende
- Department of Nutrition, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Nathércia Percegoni
- Department of Nutrition, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Jacy Gameiro
- Laboratory of Immunology, Obesity and Infectious Diseases, Department of Parasitology, Microbiology and Immunology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Eugenio D. Hottz
- Laboratory of Immunothrombosis, Department of Biochemistry, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil
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4
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Trinh T, Broxmeyer HE. Role for Leptin and Leptin Receptors in Stem Cells During Health and Diseases. Stem Cell Rev Rep 2021; 17:511-522. [PMID: 33598894 PMCID: PMC7889057 DOI: 10.1007/s12015-021-10132-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2021] [Indexed: 12/14/2022]
Abstract
Hematopoietic stem cells (HSCs) give rise to all blood and immune cells in the body. These rare cells reside in the hypoxic niche of the bone marrow (BM) where they are subjected to a complex network of regulatory factors including cellular and molecular components. To sustain hematopoiesis over the lifetime of an individual, HSCs maintain distinctive metabolic programs, and in recent years nutritional factors have been increasingly recognized as critical regulators of HSC numbers and functions. Leptin (LEP), a neuroendocrine messenger, and its receptor (LEPR) are well-known for their immunomodulatory and energy balancing effects; yet, how LEP/LEPR signaling plays a role in hematopoiesis is under-appreciated. In this review, we summarize and highlight recent work that demonstrated involvement of LEP/LEPR in hematopoiesis under steady state or stress-associated situations as well as in pathological conditions such as cardiovascular diseases and malignancies. Although the field is only in its infancy, these studies suggest evidence of potential clinical applications and proof-of-principle for more in-depth future research.
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Affiliation(s)
- Thao Trinh
- Departments of Microbiology/Immunology, Indiana University School of Medicine, 950 West Walnut Street, Bldg. R2, Room 302, Indianapolis, IN, 46202-5121, USA
| | - Hal E Broxmeyer
- Departments of Microbiology/Immunology, Indiana University School of Medicine, 950 West Walnut Street, Bldg. R2, Room 302, Indianapolis, IN, 46202-5121, USA.
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5
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Gibson D, Mehler PS. Anorexia Nervosa and the Immune System-A Narrative Review. J Clin Med 2019; 8:jcm8111915. [PMID: 31717370 PMCID: PMC6912362 DOI: 10.3390/jcm8111915] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/24/2019] [Accepted: 11/04/2019] [Indexed: 12/13/2022] Open
Abstract
The pathogenesis of an increasing number of chronic diseases is being attributed to effects of the immune system. However, its role in the development and maintenance of anorexia nervosa is seemingly under-appreciated. Yet, in examining the available research on the immune system and genetic studies in anorexia nervosa, one becomes increasingly suspicious of the immune system’s potential role in the pathophysiology of anorexia nervosa. Specifically, research is suggestive of increased levels of various pro-inflammatory cytokines as well as the spontaneous production of tumor necrosis factor in anorexia nervosa; genetic studies further support a dysregulated immune system in this disorder. Potential contributors to this dysregulated immune system are discussed including increased oxidative stress, chronic physiological/psychological stress, changes in the intestinal microbiota, and an abnormal bone marrow microenvironment, all of which are present in anorexia nervosa.
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Affiliation(s)
- Dennis Gibson
- Assistant Medical Director, ACUTE Center for Eating Disorders @ Denver Health; Assistant Professor of Medicine, University of Colorado School of Medicine; 777 Bannock St., Denver, CO 80204, USA
- Correspondence: ; Tel.: +303-602-5067; Fax: +303-602-3811
| | - Philip S Mehler
- President, Eating Recovery Center; Founder and Executive Medical Director, ACUTE Center for Eating Disorders @ Denver Health; Glassman Professor of Medicine, University of Colorado School of Medicine; 7351 E Lowry Blvd, Suite 200, Denver, CO 80230, USA;
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6
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Abstract
Pneumonia is a type of acute lower respiratory infection that is common and severe. The outcome of lower respiratory infection is determined by the degrees to which immunity is protective and inflammation is damaging. Intercellular and interorgan signaling networks coordinate these actions to fight infection and protect the tissue. Cells residing in the lung initiate and steer these responses, with additional immunity effectors recruited from the bloodstream. Responses of extrapulmonary tissues, including the liver, bone marrow, and others, are essential to resistance and resilience. Responses in the lung and extrapulmonary organs can also be counterproductive and drive acute and chronic comorbidities after respiratory infection. This review discusses cell-specific and organ-specific roles in the integrated physiological response to acute lung infection, and the mechanisms by which intercellular and interorgan signaling contribute to host defense and healthy respiratory physiology or to acute lung injury, chronic pulmonary disease, and adverse extrapulmonary sequelae. Pneumonia should no longer be perceived as simply an acute infection of the lung. Pneumonia susceptibility reflects ongoing and poorly understood chronic conditions, and pneumonia results in diverse and often persistent deleterious consequences for multiple physiological systems.
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Affiliation(s)
- Lee J Quinton
- Pulmonary Center, Boston University School of Medicine , Boston, Massachusetts
| | - Allan J Walkey
- Pulmonary Center, Boston University School of Medicine , Boston, Massachusetts
| | - Joseph P Mizgerd
- Pulmonary Center, Boston University School of Medicine , Boston, Massachusetts
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7
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Maurya R, Bhattacharya P, Dey R, Nakhasi HL. Leptin Functions in Infectious Diseases. Front Immunol 2018; 9:2741. [PMID: 30534129 PMCID: PMC6275238 DOI: 10.3389/fimmu.2018.02741] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 11/07/2018] [Indexed: 01/26/2023] Open
Abstract
Leptin, a pleiotropic protein has long been recognized to play an important role in the regulation of energy homeostasis, metabolism, neuroendocrine function, and other physiological functions through its effects on the central nervous system (CNS) and peripheral tissues. Leptin is secreted by adipose tissue and encoded by the obese (ob) gene. Leptin acts as a central mediator which regulates immunity as well as nutrition. Importantly, leptin can modulate both innate and adaptive immune responses. Leptin deficiency/resistance is associated with dysregulation of cytokine production, increased susceptibility toward infectious diseases, autoimmune disorders, malnutrition and inflammatory responses. Malnutrition induces a state of immunodeficiency and an inclination to death from communicable diseases. Infectious diseases are the disease of poor who invariably suffer from malnutrition that could result from reduced serum leptin levels. Thus, leptin has been placed at the center of many interrelated functions in various pathogenic conditions, such as bacterial, viruses and parasitic infections. We review herein, the recent advances on the role of leptin in malnutrition in pathogenesis of infectious diseases with a particular emphasis on parasitic diseases such as Leishmaniasis, Trypanosomiasis, Amoebiasis, and Malaria.
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Affiliation(s)
- Radheshyam Maurya
- Department of Animal Biology, School of Life Science, University of Hyderabad, Hyderabad, India
| | - Parna Bhattacharya
- Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
| | - Ranadhir Dey
- Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
| | - Hira L. Nakhasi
- Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
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8
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Francisco V, Pino J, Campos-Cabaleiro V, Ruiz-Fernández C, Mera A, Gonzalez-Gay MA, Gómez R, Gualillo O. Obesity, Fat Mass and Immune System: Role for Leptin. Front Physiol 2018; 9:640. [PMID: 29910742 PMCID: PMC5992476 DOI: 10.3389/fphys.2018.00640] [Citation(s) in RCA: 243] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 05/11/2018] [Indexed: 12/13/2022] Open
Abstract
Obesity is an epidemic disease characterized by chronic low-grade inflammation associated with a dysfunctional fat mass. Adipose tissue is now considered an extremely active endocrine organ that secretes cytokine-like hormones, called adipokines, either pro- or anti-inflammatory factors bridging metabolism to the immune system. Leptin is historically one of most relevant adipokines, with important physiological roles in the central control of energy metabolism and in the regulation of metabolism-immune system interplay, being a cornerstone of the emerging field of immunometabolism. Indeed, leptin receptor is expressed throughout the immune system and leptin has been shown to regulate both innate and adaptive immune responses. This review discusses the latest data regarding the role of leptin as a mediator of immune system and metabolism, with particular emphasis on its effects on obesity-associated metabolic disorders and autoimmune and/or inflammatory rheumatic diseases.
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Affiliation(s)
- Vera Francisco
- The NEIRID Group (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Servizo Galego de Saude and Instituto de Investigación Sanitaria de Santiago, Santiago University Clinical Hospital, Santiago de Compostela, Spain
| | - Jesús Pino
- The NEIRID Group (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Servizo Galego de Saude and Instituto de Investigación Sanitaria de Santiago, Santiago University Clinical Hospital, Santiago de Compostela, Spain
| | - Victor Campos-Cabaleiro
- The NEIRID Group (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Servizo Galego de Saude and Instituto de Investigación Sanitaria de Santiago, Santiago University Clinical Hospital, Santiago de Compostela, Spain
| | - Clara Ruiz-Fernández
- The NEIRID Group (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Servizo Galego de Saude and Instituto de Investigación Sanitaria de Santiago, Santiago University Clinical Hospital, Santiago de Compostela, Spain
| | - Antonio Mera
- Servizo Galego de Saude, Division of Rheumatology, Santiago University Clinical Hospital, Santiago de Compostela, Spain
| | - Miguel A Gonzalez-Gay
- Epidemiology, Genetics and Atherosclerosis Research Group on Systemic Inflammatory Diseases, Hospital Universitario Marqués de Valdecilla, Universidad de Cantabria and IDIVAL, Santander, Spain
| | - Rodolfo Gómez
- Musculoskeletal Pathology Group, Servizo Galego de Saude and Instituto de Investigación Sanitaria de Santiago, Santiago University Clinical Hospital, Santiago de Compostela, Spain
| | - Oreste Gualillo
- The NEIRID Group (Neuroendocrine Interactions in Rheumatology and Inflammatory Diseases), Servizo Galego de Saude and Instituto de Investigación Sanitaria de Santiago, Santiago University Clinical Hospital, Santiago de Compostela, Spain
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9
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Mancuso P, Curtis JL, Freeman CM, Peters-Golden M, Weinberg JB, Myers MG. Ablation of the leptin receptor in myeloid cells impairs pulmonary clearance of Streptococcus pneumoniae and alveolar macrophage bactericidal function. Am J Physiol Lung Cell Mol Physiol 2018; 315:L78-L86. [PMID: 29565180 DOI: 10.1152/ajplung.00447.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Leptin is a pleiotropic hormone produced by white adipose tissue that regulates appetite and many physiological functions, including the immune response to infection. Genetic leptin deficiency in humans and mice impairs host defenses against respiratory tract infections. Since leptin deficiency is associated with obesity and other metabolic abnormalities, we generated mice that lack the leptin receptor (LepRb) in cells of the myeloid linage (LysM-LepRb-KO) to evaluate its impact in lean metabolically normal mice in a murine model of pneumococcal pneumonia. We observed higher lung and spleen bacterial burdens in LysM-LepRb-KO mice following an intratracheal challenge with Streptococcus pneumoniae. Although numbers of leukocytes recovered from bronchoalveolar lavage fluid did not differ between groups, we did observe higher levels of pulmonary IL-13 and TNFα in LysM-LepRb-KO mice 48 h post infection. Phagocytosis and killing of ingested S. pneumoniae were also impaired in alveolar macrophages (AMs) from LysM-LepRb-KO mice in vitro and were associated with reduced LTB4 and enhanced PGE2 synthesis in vitro. Pretreatment of AMs with LTB4 and the cyclooxygenase inhibitor, indomethacin, restored phagocytosis but not bacterial killing in vitro. These results confirm our previous observations in leptin-deficient ( ob/ob) and fasted mice and demonstrate that decreased leptin action, as opposed to metabolic irregularities associated with obesity or starvation, is responsible for the defective host defense against pneumococcal pneumonia. They also provide novel targets for therapeutic intervention in humans with bacterial pneumonia.
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Affiliation(s)
- Peter Mancuso
- Department of Environmental Health Sciences, University of Michigan , Ann Arbor, Michigan.,Department of Nutritional Sciences, School of Public Health, University of Michigan , Ann Arbor, Michigan.,Graduate Program in Immunology, University of Michigan , Ann Arbor, Michigan
| | - Jeffrey L Curtis
- Graduate Program in Immunology, University of Michigan , Ann Arbor, Michigan.,Division of Pulmonary and Critical Care Medicine, University of Michigan , Ann Arbor, Michigan.,Veterans Affairs, Ann Arbor Healthcare System, Ann Arbor, Michigan
| | - Christine M Freeman
- Graduate Program in Immunology, University of Michigan , Ann Arbor, Michigan.,Division of Pulmonary and Critical Care Medicine, University of Michigan , Ann Arbor, Michigan.,Veterans Affairs, Ann Arbor Healthcare System, Ann Arbor, Michigan
| | - Marc Peters-Golden
- Graduate Program in Immunology, University of Michigan , Ann Arbor, Michigan.,Division of Pulmonary and Critical Care Medicine, University of Michigan , Ann Arbor, Michigan
| | - Jason B Weinberg
- Department of Pediatrics and Communicable Diseases, University of Michigan , Ann Arbor, Michigan.,Department of Microbiology and Immunology, University of Michigan , Ann Arbor, Michigan
| | - Martin G Myers
- Department of Integrative and Molecular Physiology, University of Michigan , Ann Arbor, Michigan
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10
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R-Phycoerythrin-labeled Mannheimia haemolytica for the simultaneous measurement of phagocytosis and intracellular reactive oxygen species production in bovine blood and bronchoalveolar lavage cells. Vet Immunol Immunopathol 2017; 196:53-59. [PMID: 29695326 DOI: 10.1016/j.vetimm.2017.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 11/21/2017] [Accepted: 12/05/2017] [Indexed: 01/09/2023]
Abstract
The present study aimed to validate the use of R-phycoerythrin (R-PE)-labeled Mannheimia haemolytica to simultaneously stimulate phagocytosis and intracellular production of reactive oxygen species (ROS) by blood phagocytes in bronchoalveolar lavage (BAL) fluid. Initially, R-PE-labeled M. haemolytica was inactivated using a water bath at 60 °C for 60 min. Afterwards, R-PE labelling of bacteria was confirmed by flow cytometry. The geometric mean fluorescence intensity of R-PE-labeled bacteria (FL2 detector, 585 ± 42 nm) was analyzed by flow cytometry and was 41.5-fold higher than the respective unlabeled controls, confirming the success of bacterial conjugation to R-PE. Phagocytosis and intracellular production of ROS by blood neutrophils and monocytes, and by BAL CD14+ macrophages, in 12 healthy 6-month-old male calves were then performed using R-PE-labeled bacteria and 2',7'-dichlorofluorescein diacetate (DCFH-DA) as probes. Confocal microscopy was used to confirm phagocytosis of R-PE-labeled M. haemolytica by phagocytes and to exclude erroneous measurements of bacteria adhering to the leukocyte membrane. The present study showed that there is no difference in the ROS production without stimulus and in the presence of M. haemolytica by peripheral blood neutrophils and monocytes, in contrast to the increased ROS production by local alveolar macrophages upon stimulation by M. haemolytica. This emphasizes the importance of alveolar macrophages in the maintenance of homeostasis and health of the respiratory system, which can be supported during the inflammatory process by the rapid recruitment of neutrophils with high microbicidal and phagocytic capacity. The method described here provides an easy and feasible tool to measure phagocytosis and intracellular ROS production by phagocytes, especially when commonly used probes for intracellular ROS production were used, such as DCFH-DA and dihydrorhodamine 123.
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11
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van Balkom BW, Gremmels H, Ooms LS, Toorop RJ, Dor FJ, de Jong OG, Michielsen LA, de Borst GJ, de Jager W, Abrahams AC, van Zuilen AD, Verhaar MC. Proteins in Preservation Fluid as Predictors of Delayed Graft Function in Kidneys from Donors after Circulatory Death. Clin J Am Soc Nephrol 2017; 12:817-824. [PMID: 28476951 PMCID: PMC5477220 DOI: 10.2215/cjn.10701016] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 02/02/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND OBJECTIVES Kidney transplantation is the preferred treatment for ESRD, and donor kidney shortage urges proper donor-recipient matching. Zero-hour biopsies provide predictive values for short- and long-term transplantation outcomes, but are invasive and may not reflect the entire organ. Alternative, more representative methods to predict transplantation outcome are required. We hypothesized that proteins accumulating in preservation fluid during cold ischemic storage can serve as biomarkers to predict post-transplantation graft function. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Levels of 158 proteins were measured in preservation fluids from kidneys donated after circulatory death (Maastricht category III) collected in two Dutch centers (University Medical Center Utrecht and Erasmus Medical Center Rotterdam) between 2013 and 2015. Five candidate biomarkers identified in a discovery set of eight kidneys with immediate function (IF) versus eight with delayed graft function (DGF) were subsequently analyzed in a verification set of 40 additional preservation fluids to establish a prediction model. RESULTS Variables tested for their contribution to a prediction model included five proteins (leptin, periostin, GM-CSF, plasminogen activator inhibitor-1, and osteopontin) and two clinical parameters (recipient body mass index [BMI] and dialysis duration) that distinguished between IF and DGF in the discovery set. Stepwise multivariable logistic regression provided a prediction model on the basis of leptin and GM-CSF. Receiver operating characteristic analysis showed an area under the curve (AUC) of 0.87, and addition of recipient BMI generated a model with an AUC of 0.89, outperforming the Kidney Donor Risk Index and the DGF risk calculator, showing AUCs of 0.55 and 0.59, respectively. CONCLUSIONS We demonstrate that donor kidney preservation fluid harbors biomarkers that, together with information on recipient BMI, predict short-term post-transplantation kidney function. Our approach is safe, easy, and performs better than current prediction algorithms, which are only on the basis of clinical parameters.
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Affiliation(s)
| | | | - Liselotte S.S. Ooms
- Division of Hepato-Pancreato-Biliary and Transplant Surgery, Department of Surgery, Erasmus Medical Center, University Medical Center, Rotterdam, The Netherlands
| | | | - Frank J.M.F. Dor
- Division of Hepato-Pancreato-Biliary and Transplant Surgery, Department of Surgery, Erasmus Medical Center, University Medical Center, Rotterdam, The Netherlands
- Directorate of Renal and Transplant Services, Imperial College Healthcare National Health Service Trust, London, United Kingdom; and
| | - Olivier G. de Jong
- Departments of Nephrology and Hypertension and
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | | | | | - Wilco de Jager
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
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12
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Kiehn JT, Tsang AH, Heyde I, Leinweber B, Kolbe I, Leliavski A, Oster H. Circadian Rhythms in Adipose Tissue Physiology. Compr Physiol 2017; 7:383-427. [PMID: 28333377 DOI: 10.1002/cphy.c160017] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The different types of adipose tissues fulfill a wide range of biological functions-from energy storage to hormone secretion and thermogenesis-many of which show pronounced variations over the course of the day. Such 24-h rhythms in physiology and behavior are coordinated by endogenous circadian clocks found in all tissues and cells, including adipocytes. At the molecular level, these clocks are based on interlocked transcriptional-translational feedback loops comprised of a set of clock genes/proteins. Tissue-specific clock-controlled transcriptional programs translate time-of-day information into physiologically relevant signals. In adipose tissues, clock gene control has been documented for adipocyte proliferation and differentiation, lipid metabolism as well as endocrine function and other adipose oscillations are under control of systemic signals tied to endocrine, neuronal, or behavioral rhythms. Circadian rhythm disruption, for example, by night shift work or through genetic alterations, is associated with changes in adipocyte metabolism and hormone secretion. At the same time, adipose metabolic state feeds back to central and peripheral clocks, adjusting behavioral and physiological rhythms. In this overview article, we summarize our current knowledge about the crosstalk between circadian clocks and energy metabolism with a focus on adipose physiology. © 2017 American Physiological Society. Compr Physiol 7:383-427, 2017.
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Affiliation(s)
- Jana-Thabea Kiehn
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Anthony H Tsang
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Isabel Heyde
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Brinja Leinweber
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Isa Kolbe
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
| | - Alexei Leliavski
- Institute of Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Henrik Oster
- Chronophysiology Group, Medical Department I, University of Lübeck, Lübeck, Germany
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13
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Dolan JM, Weinberg JB, O'Brien E, Abashian A, Procario MC, Aronoff DM, Crofford LJ, Peters-Golden M, Ward L, Mancuso P. Increased lethality and defective pulmonary clearance of Streptococcus pneumoniae in microsomal prostaglandin E synthase-1-knockout mice. Am J Physiol Lung Cell Mol Physiol 2016; 310:L1111-20. [PMID: 27059285 DOI: 10.1152/ajplung.00220.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 03/31/2016] [Indexed: 01/14/2023] Open
Abstract
The production of prostaglandin E2 (PGE2) increases dramatically during pneumococcal pneumonia, and this lipid mediator impairs alveolar macrophage (AM)-mediated innate immune responses. Microsomal prostaglandin E synthase-1 (mPGES-1) is a key enzyme involved in the synthesis of PGE2, and its expression is enhanced during bacterial infections. Genetic deletion of mPGES-1 in mice results in diminished PGE2 production and elevated levels of other prostaglandins after infection. Since PGE2 plays an important immunoregulatory role during bacterial pneumonia we assessed the impact of mPGES-1 deletion in the host defense against pneumococcal pneumonia in vivo and in AMs in vitro. Wild-type (WT) and mPGES-1 knockout (KO) mice were challenged with Streptococcus pneumoniae via the intratracheal route. Compared with WT animals, we observed reduced survival and increased lung and spleen bacterial burdens in mPGES-1 KO mice 24 and 48 h after S. pneumoniae infection. While we found modest differences between WT and mPGES-1 KO mice in pulmonary cytokines, AMs from mPGES-1 KO mice exhibited defective killing of ingested bacteria in vitro that was associated with diminished inducible nitric oxide synthase expression and reduced nitric oxide (NO) synthesis. Treatment of AMs from mPGES-1 KO mice with an NO donor restored bacterial killing in vitro. These results suggest that mPGES-1 plays a critical role in bacterial pneumonia and that genetic ablation of this enzyme results in diminished pulmonary host defense in vivo and in vitro. These results suggest that specific inhibition of PGE2 synthesis by targeting mPGES-1 may weaken host defense against bacterial infections.
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Affiliation(s)
- Jennifer M Dolan
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Jason B Weinberg
- Department of Pediatrics and Communicable Disease and Microbiology and Immunology, School of Medicine, University of Michigan, Ann Arbor, Michigan
| | - Edmund O'Brien
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Anya Abashian
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Megan C Procario
- Department of Pediatrics and Communicable Disease and Microbiology and Immunology, School of Medicine, University of Michigan, Ann Arbor, Michigan
| | - David M Aronoff
- Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Leslie J Crofford
- Division of Rheumatology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Marc Peters-Golden
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan; Graduate Program in Immunology, University of Michigan, Ann Arbor, Michigan; and
| | - Lindsay Ward
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Peter Mancuso
- Graduate Program in Immunology, University of Michigan, Ann Arbor, Michigan; and Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan
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14
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Naylor C, Petri WA. Leptin Regulation of Immune Responses. Trends Mol Med 2016; 22:88-98. [PMID: 26776093 DOI: 10.1016/j.molmed.2015.12.001] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/06/2015] [Accepted: 12/10/2015] [Indexed: 12/19/2022]
Abstract
Leptin is a regulatory hormone with multiple roles in the immune system. We favor the concept that leptin signaling 'licenses' various immune cells to engage in immune responses and/or to differentiate. Leptin is an inflammatory molecule that is capable of activating both adaptive and innate immunity. It can also 'enhance' immune functions, including inflammatory cytokine production in macrophages, granulocyte chemotaxis, and increased Th17 proliferation. Leptin can also 'inhibit' cells; CD4(+) T cells are inhibited from differentiating into regulatory T cells in the presence of elevated leptin, while NK cells can exhibit impaired cytotoxicity under the same circumstances. Consequently, understanding the effect of leptin signaling is important to appreciate various aspects of immune dysregulation observed in malnutrition, obesity, and autoimmunity.
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Affiliation(s)
- Caitlin Naylor
- Medical Research Council Unit, Atlantic Blvd, Serrekunda, Gambia.
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15
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Ather JL, Poynter ME, Dixon AE. Immunological characteristics and management considerations in obese patients with asthma. Expert Rev Clin Immunol 2015; 11:793-803. [PMID: 25914932 DOI: 10.1586/1744666x.2015.1040394] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Obesity is associated with severe, poorly controlled asthma that does not respond as well to therapy as asthma in leaner asthmatics. Important insights gained from animal models of obesity and asthma suggests that different forms of obesity may lead to different manifestations of airway disease: obesity is associated with both innate increased airway reactivity and altered responses to aeroallergen and pollutant challenges. In humans, at least two broad groups of obese asthmatics have been recognized: one that is likely unique to obesity and another that is likely lean allergic asthma much complicated by obesity. This article will discuss what we have learned about the immunological and pathophysiological basis of asthma in obesity from animal and human studies, and how this might guide therapy.
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Affiliation(s)
- Jennifer L Ather
- Pulmonary and Critical Care Medicine, University of Vermont College of Medicine, Given D208, 89 Beaumont Avenue, Burlington, VT 05405, USA
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16
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Conde J, Scotece M, Abella V, López V, Pino J, Gómez-Reino JJ, Gualillo O. An update on leptin as immunomodulator. Expert Rev Clin Immunol 2014; 10:1165-70. [DOI: 10.1586/1744666x.2014.942289] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Zhu M, Li D, Wu Y, Huang X, Wu M. TREM-2 promotes macrophage-mediated eradication of Pseudomonas aeruginosa via a PI3K/Akt pathway. Scand J Immunol 2014; 79:187-96. [PMID: 24383713 DOI: 10.1111/sji.12148] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 12/16/2013] [Indexed: 01/11/2023]
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM-2) is a cell surface receptor abundantly expressed on myeloid lineage cells such as macrophages and dendritic cells. It is reported that TREM-2 functions as an inflammatory inhibitor in macrophages and dendritic cells. However, the role of TREM-2 in bacterial killing remains unclear. This study explored the role of TREM-2 in bacterial eradication of Pseudomonas aeruginosa (PA), a Gram-negative bacterium which causes various opportunistic infections. Phagocytosis assay assessed by flow cytometry suggested that TREM-2 was not involved in the uptake of PA by macrophages, while bacterial plate count data showed that TREM-2 was required for macrophage-mediated intracellular killing of PA. Moreover, our results demonstrated that TREM-2 promoted macrophage killing by enhancing reactive oxygen species (ROS), but not nitric oxygen (NO) production. Treatment with N-acetylcysteine, a ROS scavenger, diminished the TREM-2-mediated intracellular killing of PA. To further investigate the underlined mechanisms of TREM-2-promoted bacterial killing, we examined the activation of downstream mitogen-activated protein kinases and PI3K/Akt pathway. Western blot data showed that silencing of TREM-2 inhibited phosphorylation of Akt, but not ERK, JNK or P38. In addition, pretreatment with PI3K active product PIP3 DiC16 reversed the elevation of intracellular bacterial load in TREM-2-silenced macrophages, while PI3K inhibitor wortmannin restored the decline of bacterial load in TREM-2-overexpressed macrophages. These data together suggested that the TREM-2-mediated bacterial killing is dependent on the activation of PI3K/Akt signalling, which may provide a better understanding of the host antibacterial immune defence.
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Affiliation(s)
- M Zhu
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China; Key Laboratory of Tropical Diseases Control, Ministry of Education, Sun Yat-sen University, Guangzhou, China
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18
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Vernooy JHJ, Ubags NDJ, Brusselle GG, Tavernier J, Suratt BT, Joos GF, Wouters EFM, Bracke KR. Leptin as regulator of pulmonary immune responses: involvement in respiratory diseases. Pulm Pharmacol Ther 2013; 26:464-72. [PMID: 23542720 PMCID: PMC4122282 DOI: 10.1016/j.pupt.2013.03.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 03/08/2013] [Accepted: 03/19/2013] [Indexed: 12/11/2022]
Abstract
Leptin is an adipocyte-derived hormone, recognized as a critical mediator of the balance between food intake and energy expenditure by signalling through its functional receptor (Ob-Rb) in the hypothalamus. Structurally, leptin belongs to the long-chain helical cytokine family, and is now known to have pleiotropic functions in both innate and adaptive immunity. The presence of the functional leptin receptor in the lung together with evidence of increased airspace leptin levels arising during pulmonary inflammation, suggests an important role for leptin in lung development, respiratory immune responses and eventually pathogenesis of inflammatory respiratory diseases. The purpose of this article is to review our current understanding of leptin and its functional role on the different resident cell types of the lung in health as well as in the context of three major respiratory conditions being chronic obstructive pulmonary disease (COPD), asthma, and pneumonia.
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Affiliation(s)
- Juanita H J Vernooy
- Department of Respiratory Medicine, Maastricht University Medical Center+, PO Box 5800, 6202 AZ Maastricht, The Netherlands.
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19
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Spreadbury I, Samis AJW. Evolutionary Aspects of Obesity, Insulin Resistance, and Cardiovascular Risk. CURRENT CARDIOVASCULAR RISK REPORTS 2013. [DOI: 10.1007/s12170-013-0293-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Zhang AJX, To KKW, Li C, Lau CCY, Poon VKM, Chan CCS, Zheng BJ, Hung IFN, Lam KSL, Xu A, Yuen KY. Leptin mediates the pathogenesis of severe 2009 pandemic influenza A(H1N1) infection associated with cytokine dysregulation in mice with diet-induced obesity. J Infect Dis 2013; 207:1270-80. [PMID: 23325916 DOI: 10.1093/infdis/jit031] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Obesity is associated with a high circulating leptin level and severe 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09) infection. The mechanism for severe lung injury in obese patients and the specific treatment strategy remain elusive. METHOD We studied the pathogenesis of A(H1N1)pdm09 infection in a mouse model of diet-induced obesity. RESULTS Obese mice had significantly higher initial pulmonary viral titer and mortality after challenge with A(H1N1)pdm09, compared with age-matched lean mice. Compared with lean mice, obese mice had heightened proinflammatory cytokine and chemokine levels and more severe pulmonary inflammatory damage. Furthermore, obese mice had a higher preexisting serum leptin level but a lower preexisting adiponectin level. Recombinant mouse leptin increased the interleukin 6 (IL-6) messenger RNA expression in mouse single-lung-cell preparations, mouse macrophages, and mouse lung epithelial cell lines infected with A(H1N1)pdm09. Administration of anti-leptin antibody improved the survival of infected obese mice, with associated reductions in pulmonary levels of the proinflammatory cytokines IL-6 and interleukin 1β but not the pulmonary viral titer. CONCLUSIONS Our findings suggest that preexisting high levels of circulating leptin contribute to the development of severe lung injury by A(H1N1)pdm09 in mice with diet-induced obesity. The therapeutic strategy of leptin neutralization for the reduction of proinflammatory responses and pulmonary damage in obese patients warrants further investigations.
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Affiliation(s)
- Anna J X Zhang
- Carol Yu Centre for Infection and Division of Infectious Diseases, Department of Microbiology, University of Hong Kong, Queen Mary Hospital, Pokfulam Rd, Pokfulam, Hong Kong SAR, China
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