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Inoue T, Ito Y, Nishizawa N, Eshima K, Kojo K, Otaka F, Betto T, Yamane S, Tsujikawa K, Koizumi W, Majima M. RAMP1 in Kupffer cells is a critical regulator in immune-mediated hepatitis. PLoS One 2018; 13:e0200432. [PMID: 30462657 PMCID: PMC6248891 DOI: 10.1371/journal.pone.0200432] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 09/17/2018] [Indexed: 01/01/2023] Open
Abstract
The significance of the relationship between the nervous and immune systems with respect to disease course is increasingly apparent. Immune cells in the liver and spleen are responsible for the development of acute liver injury, yet the regulatory mechanisms of the interactions remain elusive. Calcitonin gene-related peptide (CGRP), which is released from the sensory nervous system, regulates innate immune activation via receptor activity-modifying protein 1 (RAMP1), a subunit of the CGRP receptor. Here, we show that RAMP1 in Kupffer cells (KCs) plays a critical role in the etiology of immune-mediated hepatitis. RAMP1-deficient mice with concanavalin A (ConA)-mediated hepatitis, characterized by severe liver injury accompanied by infiltration of immune cells and increased secretion of pro-inflammatory cytokines by KCs and splenic T cells, showed poor survival. Removing KCs ameliorated liver damage, while depleting T cells or splenectomy led to partial amelioration. Adoptive transfer of splenic T cells from RAMP1-deficient mice led to a modest increase in liver injury. Co-culture of KCs with splenic T cells led to increased cytokine expression by both cells in a RAMP1-dependent manner. Thus, immune-mediated hepatitis develops via crosstalk between immune cells. RAMP1 in KCs is a key regulator of immune responses.
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Affiliation(s)
- Tomoyoshi Inoue
- Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
- Department of Gastroenterology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
- Department of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Yoshiya Ito
- Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
- Department of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Nobuyuki Nishizawa
- Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
- Department of Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Koji Eshima
- Department of Immunology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Ken Kojo
- Department of Immunology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Fumisato Otaka
- Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
- Department of Gastroenterology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
- Department of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Tomohiro Betto
- Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
- Department of Gastroenterology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
- Department of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Sakiko Yamane
- Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
- Department of Gastroenterology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
- Department of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Kazutake Tsujikawa
- Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Wasaburo Koizumi
- Department of Gastroenterology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Masataka Majima
- Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
- Department of Pharmacology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
- * E-mail:
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Abstract
The interplay between the immune and nervous systems has been acknowledged in the past, but only more recent studies have started to unravel the cellular and molecular players of such interactions. Mounting evidence indicates that environmental signals are sensed by discrete neuro-immune cell units (NICUs), which represent defined anatomical locations in which immune and neuronal cells colocalize and functionally interact to steer tissue physiology and protection. These units have now been described in multiple tissues throughout the body, including lymphoid organs, adipose tissue, and mucosal barriers. As such, NICUs are emerging as important orchestrators of multiple physiological processes, including hematopoiesis, organogenesis, inflammation, tissue repair, and thermogenesis. In this review we focus on the impact of NICUs in tissue physiology and how this fast-evolving field is driving a paradigm shift in our understanding of immunoregulation and organismal physiology.
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Affiliation(s)
- Cristina Godinho-Silva
- Champalimaud Research, Champalimaud Centre for the Unknown, 1400-038 Lisboa, Portugal; , ,
| | - Filipa Cardoso
- Champalimaud Research, Champalimaud Centre for the Unknown, 1400-038 Lisboa, Portugal; , ,
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53
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Abstract
Bones provide both skeletal scaffolding and space for hematopoiesis in its marrow. Previous work has shown that these functions were tightly regulated by the nervous system. The central and peripheral nervous systems tightly regulate compact bone remodeling, its metabolism, and hematopoietic homeostasis in the bone marrow (BM). Accumulating evidence indicates that the nervous system, which fine-tunes inflammatory responses and alterations in neural functions, may regulate autoimmune diseases. Neural signals also influence the progression of hematological malignancies such as acute and chronic myeloid leukemias. Here, we review the interplay of the nervous system with bone, BM, and immunity, and discuss future challenges to target hematological diseases through modulation of activity of the nervous system.
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Affiliation(s)
- Maria Maryanovich
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Shoichiro Takeishi
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Paul S Frenette
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461
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54
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Badner A, Hacker J, Hong J, Mikhail M, Vawda R, Fehlings MG. Splenic involvement in umbilical cord matrix-derived mesenchymal stromal cell-mediated effects following traumatic spinal cord injury. J Neuroinflammation 2018; 15:219. [PMID: 30075797 PMCID: PMC6091078 DOI: 10.1186/s12974-018-1243-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/28/2018] [Indexed: 01/05/2023] Open
Abstract
Background The spleen plays an important role in erythrocyte turnover, adaptive immunity, antibody production, and the mobilization of monocytes/macrophages (Mφ) following tissue injury. In response to trauma, the spleen initiates production of inflammatory cytokines, which in turn recruit immune cells to the inflamed tissue, exacerbating damage. Our previous work has shown that intravenous mesenchymal stromal cell (MSC) infusion has potent immunomodulatory effects following spinal cord injury (SCI), associated with the transplanted cells homing to and persisting within the spleen. Therefore, this work aimed to characterize the relationship between the splenic inflammatory response and SCI pathophysiology, emphasizing splenic involvement in MSC-mediated effects. Methods Using a rodent model of cervical clip-compression SCI, secondary tissue damage and functional recovery were compared between splenectomised rodents and those with a sham procedure. Subsequently, 2.5 million MSCs from the term human umbilical cord matrix cells (HUCMCs) were infused via tail vein at 1-h post-SCI and the effects were assessed in the presence or absence of a spleen. Results Splenectomy alone had no effect on lesion volume, hemorrhage, or inflammation. There was also no significant difference between the groups in functional recovery and those in lesion morphometry. Yet, while the infusion of HUCMCs reduced spinal cord hemorrhage and increased systemic levels of IL-10 in the presence of a spleen, these effects were lost with splenectomy. Further, HUCMC infusion was shown to alter the expression levels of splenic cytokines, suggesting that the spleen is an important target and site of MSC effects. Conclusions Our results provide a link between MSC function and splenic inflammation, a finding that can help tailor the cells/transplantation approach to enhance therapeutic efficacy. Electronic supplementary material The online version of this article (10.1186/s12974-018-1243-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anna Badner
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, Ontario, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Justin Hacker
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, Ontario, M5T 2S8, Canada
| | - James Hong
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, Ontario, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Mirriam Mikhail
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, Ontario, M5T 2S8, Canada
| | - Reaz Vawda
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, Ontario, M5T 2S8, Canada
| | - Michael G Fehlings
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, Ontario, M5T 2S8, Canada. .,Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Division of Neurosurgery, Toronto Western Hospital, 399 Bathurst St. Suite 4WW-449, Toronto, Ontario, M5T 2S8, Canada.
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Chmilewsky F, About I, Cooper LF, Chung SH. C5L2 Silencing in Human Pulp Fibroblasts Enhances Nerve Outgrowth Under Lipoteichoic Acid Stimulation. J Endod 2018; 44:1396-1401. [PMID: 30032862 DOI: 10.1016/j.joen.2018.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/18/2018] [Accepted: 05/03/2018] [Indexed: 01/09/2023]
Abstract
INTRODUCTION We recently reported that caries-associated C5a receptor (C5aR) expression and activation result in up-regulation of brain-derived neurotropic factor secretion by pulp fibroblasts inducing prominent neurite outgrowth toward the carious site. Our data further showed a negative regulation of this brain-derived neurotropic factor secretion by C5L2, another C5aR. C5L2 was considered a nonfunctional receptor and thus has received much less attention than C5aR. The aim of this study was to identify the role of C5L2 in pulp fibroblast-mediated neurite outgrowth. METHODS In this study, lipoteichoic acid (LTA) was used to mimic dental caries-like inflammation. To evaluate the role of C5L2 in pulp neurite outgrowth, human pulp fibroblasts were C5L2 small interfering RNA silenced and cocultured with human neurons in a nerve growth assay system. RESULTS C5L2 silencing drastically increased the neurite outgrowth toward the LTA-stimulated pulp fibroblasts. The number of neurites detected was increased in the LTA-treated pulp fibroblasts. CONCLUSIONS Our results show that C5L2 constitutes a negative regulator of the neurite outgrowth under LTA stimulation. Of the events occurring during dentin-pulp regeneration, nerve regeneration is the key factor for maintaining tooth viability after infection or injury. Our study provides a foundation for creating therapeutic tools that target pulp fibroblasts during pulp/nerve regeneration.
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Affiliation(s)
- Fanny Chmilewsky
- Department of Oral Biology, University of Illinois at Chicago, Chicago, Illinois
| | - Imad About
- Department of Oral Biology, Aix Marseille University, Marseille, France
| | - Lyndon F Cooper
- Department of Oral Biology, University of Illinois at Chicago, Chicago, Illinois
| | - Seung H Chung
- Department of Oral Biology, University of Illinois at Chicago, Chicago, Illinois.
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Vasamsetti SB, Florentin J, Coppin E, Stiekema LCA, Zheng KH, Nisar MU, Sembrat J, Levinthal DJ, Rojas M, Stroes ESG, Kim K, Dutta P. Sympathetic Neuronal Activation Triggers Myeloid Progenitor Proliferation and Differentiation. Immunity 2018; 49:93-106.e7. [PMID: 29958804 PMCID: PMC6051926 DOI: 10.1016/j.immuni.2018.05.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 03/23/2018] [Accepted: 05/15/2018] [Indexed: 01/31/2023]
Abstract
There is a growing body of research on the neural control of immunity and inflammation. However, it is not known whether the nervous system can regulate the production of inflammatory myeloid cells from hematopoietic progenitor cells in disease conditions. Myeloid cell numbers in diabetic patients were strongly correlated with plasma concentrations of norepinephrine, suggesting the role of sympathetic neuronal activation in myeloid cell production. The spleens of diabetic patients and mice contained higher numbers of tyrosine hydroxylase (TH)-expressing leukocytes that produced catecholamines. Granulocyte macrophage progenitors (GMPs) expressed the β2 adrenergic receptor, a target of catecholamines. Ablation of splenic sympathetic neuronal signaling using surgical, chemical, and genetic approaches diminished GMP proliferation and myeloid cell development. Finally, mice lacking TH-producing leukocytes had reduced GMP proliferation, resulting in diminished myelopoiesis. Taken together, our study demonstrates that catecholamines produced by leukocytes and sympathetic nerve termini promote GMP proliferation and myeloid cell development.
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Affiliation(s)
- Sathish Babu Vasamsetti
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jonathan Florentin
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Emilie Coppin
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Lotte C A Stiekema
- Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Kang H Zheng
- Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Muhammad Umer Nisar
- Department of Bioengineering, University of Pittsburgh School of Engineering, Pittsburgh, PA, USA
| | - John Sembrat
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA; Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA; The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - David J Levinthal
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mauricio Rojas
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA; Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA; The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, University of Pittsburgh Medical Center, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Erik S G Stroes
- Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Kang Kim
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh School of Engineering, Pittsburgh, PA, USA; Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Partha Dutta
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA; Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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57
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Noble BT, Brennan FH, Popovich PG. The spleen as a neuroimmune interface after spinal cord injury. J Neuroimmunol 2018; 321:1-11. [PMID: 29957379 DOI: 10.1016/j.jneuroim.2018.05.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 01/17/2023]
Abstract
Traumatic spinal cord injury (SCI) causes widespread damage to neurons, glia and endothelia located throughout the spinal parenchyma. In response to the injury, resident and blood-derived leukocytes orchestrate an intraspinal inflammatory response that propagates secondary neuropathology and also promotes tissue repair. SCI also negatively affects autonomic control over peripheral immune organs, notably the spleen. The spleen is the largest secondary lymphoid organ in mammals, with major roles in blood filtration and host defense. Splenic function is carefully regulated by neuroendocrine mechanisms that ensure that the immune responses to infection or injury are proportionate to the initiating stimulus, and can be terminated when the stimulus is cleared. After SCI, control over the viscera, including endocrine and lymphoid tissues is lost due to damage to spinal autonomic (sympathetic) circuitry. This review begins by examining the normal structure and function of the spleen including patterns of innervation and the role played by the nervous system in regulating spleen function. We then describe how after SCI, loss of proper neural control over splenic function leads to systems-wide neuropathology, immune suppression and autoimmunity. We conclude by discussing opportunities for targeting the spleen to restore immune homeostasis, reduce morbidity and mortality, and improve functional recovery after SCI.
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Affiliation(s)
- Benjamin T Noble
- Neuroscience Graduate Studies Program, Center for Brain and Spinal Cord Repair, Department of Neuroscience, The Ohio State University, Columbus 43210, OH, USA
| | - Faith H Brennan
- Department of Neuroscience, Center for Brain and Spinal Cord Repair, Wexner Medical Center, The Ohio State University, Columbus 43210, OH, USA
| | - Phillip G Popovich
- Department of Neuroscience, Center for Brain and Spinal Cord Repair, Wexner Medical Center, The Ohio State University, Columbus 43210, OH, USA.
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58
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Hu D, Nicholls PK, Yin C, Kelman K, Yuan Q, Greene WK, Shi Z, Ma B. Immunofluorescent Localization of Non-myelinating Schwann Cells and Their Interactions With Immune Cells in Mouse Thymus. J Histochem Cytochem 2018; 66:775-785. [PMID: 29775115 DOI: 10.1369/0022155418778543] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The thymus is innervated by sympathetic/parasympathetic nerve fibers from the peripheral nervous system (PNS), suggesting a neural regulation of thymic function including T-cell development. Despite some published studies, data on the innervation and nerve-immune interaction inside the thymus remain limited. In the present study, we used immunofluorescent staining of glial fibrillary acidic protein (GFAP) coupled with confocal microscopy/three-dimensional (3D) reconstruction to reveal the distribution of non-myelinating Schwann cells (NMSC) and their interactions with immune cells inside mouse thymus. Our results demonstrate (1) the presence of an extensive network of NMSC processes in all compartments of the thymus including the capsule, subcapsular region, cortex, cortico-medullary junction, and medulla; (2) close associations/interactions of NMSC processes with blood vessels, indicating the neural control of blood flow inside the thymus; (3) the close "synapse-like" association of NMSC processes with various subsets of dendritic cells (DC; e.g., B220+ DCs, CD4+ DCs, and CD8+ DCs), and lymphocytes (B cells, CD4+/CD8+ thymocytes). Our novel findings concerning the distribution of NMSCs and the associations of NMSCs and immune cells inside mouse thymus should help us understand the anatomical basis and the mechanisms through which the PNS affects T-cell development and thymic endocrine function in health and disease.
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Affiliation(s)
- Dailun Hu
- Clinical College, Hebei Medical University, Shijiazhuang, China
| | - Philip K Nicholls
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
| | - Changfu Yin
- Clinical College, Hebei Medical University, Shijiazhuang, China
| | - Khama Kelman
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
| | - Qionglan Yuan
- School of Medicine, Tongji University, Shanghai, China
| | - Wayne K Greene
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
| | - Zhongli Shi
- Clinical College, Hebei Medical University, Shijiazhuang, China
| | - Bin Ma
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
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Wei Q, Frenette PS. Niches for Hematopoietic Stem Cells and Their Progeny. Immunity 2018; 48:632-648. [PMID: 29669248 PMCID: PMC6103525 DOI: 10.1016/j.immuni.2018.03.024] [Citation(s) in RCA: 256] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/28/2017] [Accepted: 03/20/2018] [Indexed: 01/01/2023]
Abstract
Steady-state hematopoietic stem cells' (HSCs) self-renewal and differentiation toward their mature progeny in the adult bone marrow is tightly regulated by cues from the microenvironment. Recent insights into the cellular and molecular constituents have uncovered a high level of complexity. Here, we review emerging evidence showing how HSCs and their progeny are regulated by an interdependent network of mesenchymal stromal cells, nerve fibers, the vasculature, and also other hematopoietic cells. Understanding the interaction mechanisms in these intricate niches will provide great opportunities for HSC-related therapies and immune modulation.
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Affiliation(s)
- Qiaozhi Wei
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Paul S Frenette
- Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Departmentof Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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60
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Bellinger DL, Lorton D. Sympathetic Nerve Hyperactivity in the Spleen: Causal for Nonpathogenic-Driven Chronic Immune-Mediated Inflammatory Diseases (IMIDs)? Int J Mol Sci 2018; 19:ijms19041188. [PMID: 29652832 PMCID: PMC5979464 DOI: 10.3390/ijms19041188] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 04/05/2018] [Accepted: 04/05/2018] [Indexed: 12/21/2022] Open
Abstract
Immune-Mediated Inflammatory Diseases (IMIDs) is a descriptive term coined for an eclectic group of diseases or conditions that share common inflammatory pathways, and for which there is no definitive etiology. IMIDs affect the elderly most severely, with many older individuals having two or more IMIDs. These diseases include, but are not limited to, type-1 diabetes, obesity, hypertension, chronic pulmonary disease, coronary heart disease, inflammatory bowel disease, and autoimmunity, such as rheumatoid arthritis (RA), Sjőgren's syndrome, systemic lupus erythematosus, psoriasis, psoriatic arthritis, and multiple sclerosis. These diseases are ostensibly unrelated mechanistically, but increase in frequency with age and share chronic systemic inflammation, implicating major roles for the spleen. Chronic systemic and regional inflammation underlies the disease manifestations of IMIDs. Regional inflammation and immune dysfunction promotes targeted end organ tissue damage, whereas systemic inflammation increases morbidity and mortality by affecting multiple organ systems. Chronic inflammation and skewed dysregulated cell-mediated immune responses drive many of these age-related medical disorders. IMIDs are commonly autoimmune-mediated or suspected to be autoimmune diseases. Another shared feature is dysregulation of the autonomic nervous system and hypothalamic pituitary adrenal (HPA) axis. Here, we focus on dysautonomia. In many IMIDs, dysautonomia manifests as an imbalance in activity/reactivity of the sympathetic and parasympathetic divisions of the autonomic nervous system (ANS). These major autonomic pathways are essential for allostasis of the immune system, and regulating inflammatory processes and innate and adaptive immunity. Pathology in ANS is a hallmark and causal feature of all IMIDs. Chronic systemic inflammation comorbid with stress pathway dysregulation implicate neural-immune cross-talk in the etiology and pathophysiology of IMIDs. Using a rodent model of inflammatory arthritis as an IMID model, we report disease-specific maladaptive changes in β₂-adrenergic receptor (AR) signaling from protein kinase A (PKA) to mitogen activated protein kinase (MAPK) pathways in the spleen. Beta₂-AR signal "shutdown" in the spleen and switching from PKA to G-coupled protein receptor kinase (GRK) pathways in lymph node cells drives inflammation and disease advancement. Based on these findings and the existing literature in other IMIDs, we present and discuss relevant literature that support the hypothesis that unresolvable immune stimulation from chronic inflammation leads to a maladaptive disease-inducing and perpetuating sympathetic response in an attempt to maintain allostasis. Since the role of sympathetic dysfunction in IMIDs is best studied in RA and rodent models of RA, this IMID is the primary one used to evaluate data relevant to our hypothesis. Here, we review the relevant literature and discuss sympathetic dysfunction as a significant contributor to the pathophysiology of IMIDs, and then discuss a novel target for treatment. Based on our findings in inflammatory arthritis and our understanding of common inflammatory process that are used by the immune system across all IMIDs, novel strategies to restore SNS homeostasis are expected to provide safe, cost-effective approaches to treat IMIDs, lower comorbidities, and increase longevity.
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Affiliation(s)
- Denise L Bellinger
- Department of Pathology and Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Dianne Lorton
- College of Arts and Sciences, Kent State University, Kent, OH 44304, USA.
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61
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Ma B, Yin C, Hu D, Newman M, Nicholls PK, Wu Z, Greene WK, Shi Z. Distribution of non-myelinating Schwann cells and their associations with leukocytes in mouse spleen revealed by immunofluorescence staining. Eur J Histochem 2018; 62:2890. [PMID: 29943953 PMCID: PMC6038114 DOI: 10.4081/ejh.2018.2890] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 03/06/2018] [Accepted: 03/09/2018] [Indexed: 12/31/2022] Open
Abstract
The nervous system and the immune system communicate extensively with each other in order to maintain homeostasis and to regulate the immune response. The peripheral nervous system (PNS) communicates specifically with the immune system according to local interactions, including the “hardwiring” of sympathetic/parasympathetic (efferent) and sensory nerves (afferent) to lymphoid tissue and organs. To reveal this type of bidirectional neuroimmune interaction at the microscopic level, we used immunofluorescent staining of glial fibrillary acidic protein (GFAP) coupled with confocal microscopy/3D reconstruction to reveal the distribution of nonmyelinating Schwann cells (NMSCs) and their interactions with immune cells inside mouse spleen. Our results demonstrate i) the presence of an extensive network of NMSC processes in all splenic compartments including the splenic nodules, periarteriolar lymphoid sheath (PALS), marginal zone, trabecula, and red pulp; ii) the close association of NMSC processes with blood vessels (including central arteries and their branches, marginal sinuses, penicillar arterioles and splenic sinuses); iii) the close “synapse-like” interaction/association of NMSC processes with various subsets of dendritic cells (DCs; e.g., CD4+CD11c+ DCs, B220+CD11c+ DCs, and F4/80+ CD11c+ DCs), macrophages (F4/80+), and lymphocytes (B cells, CD4+ T helper cells). Our novel findings concerning the distribution of NMSCs and NMSC-leukocytes interactions inside mouse spleen should improve our understanding of the mechanisms through which the PNS affects cellular- and humoral-mediated immune responses in a variety of health conditions and infectious/non-infectious diseases.
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Affiliation(s)
- Bin Ma
- Murdoch University, School of Veterinary and Life Sciences.
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62
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The temporospatial pattern of energy metabolism coordinates the interactions between the bones and other organ systems. J Oral Biosci 2018. [DOI: 10.1016/j.job.2017.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Hoover DB, Brown TC, Miller MK, Schweitzer JB, Williams DL. Loss of Sympathetic Nerves in Spleens from Patients with End Stage Sepsis. Front Immunol 2017; 8:1712. [PMID: 29270174 PMCID: PMC5723638 DOI: 10.3389/fimmu.2017.01712] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/20/2017] [Indexed: 01/22/2023] Open
Abstract
The spleen is an important site for central regulation of immune function by noradrenergic sympathetic nerves, but little is known about this major region of neuroimmune communication in humans. Experimental studies using animal models have established that sympathetic innervation of the spleen is essential for cholinergic anti-inflammatory responses evoked by vagal nerve stimulation, and clinical studies are evaluating this approach for treating inflammatory diseases. Most data on sympathetic nerves in spleen derive from rodent studies, and this work has established that remodeling of sympathetic innervation can occur during inflammation. However, little is known about the effects of sepsis on spleen innervation. Our primary goals were to (i) localize noradrenergic nerves in human spleen by immunohistochemistry for tyrosine hydroxylase (TH), a specific noradrenergic marker, (ii) determine if nerves occur in close apposition to leukocytes, and (iii) determine if splenic sympathetic innervation is altered in patients who died from end stage sepsis. Staining for vesicular acetylcholine transporter (VAChT) was done to screen for cholinergic nerves. Archived paraffin tissue blocks were used. Control samples were obtained from trauma patients or patients who died after hemorrhagic stroke. TH + nerves were associated with arteries and arterioles in all control spleens, occurring in bundles or as nerve fibers. Individual TH + nerve fibers entered the perivascular region where some appeared in close apposition to leukocytes. In marked contrast, spleens from half of the septic patients lacked TH + nerves fibers and the average abundance of TH + nerves for the septic group was only 16% of that for the control group (control: 0.272 ± 0.060% area, n = 6; sepsis: 0.043 ± 0.026% area, n = 8; P < 0.005). All spleens lacked cholinergic innervation. Our results provide definitive evidence for the distribution of noradrenergic nerves in normal human spleen and the first evidence for direct sympathetic innervation of leukocytes in human spleen. We also provide the first evidence for marked loss of noradrenergic nerves in patients who died from sepsis. Such nerve loss could impair neuroimmunomodulation and may not be limited to the spleen.
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Affiliation(s)
- Donald B Hoover
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States.,Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Thomas Christopher Brown
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Madeleine K Miller
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - John B Schweitzer
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States.,Department of Pathology, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - David L Williams
- Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States.,Department of Surgery, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
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64
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Sîrbulescu RF, Boehm CK, Soon E, Wilks MQ, Ilieş I, Yuan H, Maxner B, Chronos N, Kaittanis C, Normandin MD, El Fakhri G, Orgill DP, Sluder AE, Poznansky MC. Mature B cells accelerate wound healing after acute and chronic diabetic skin lesions. Wound Repair Regen 2017; 25:774-791. [PMID: 28922523 DOI: 10.1111/wrr.12584] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 08/16/2017] [Indexed: 12/11/2022]
Abstract
Chronic wounds affect 12-15% of patients with diabetes and are associated with a drastic decrease in their quality of life. Here, we demonstrate that purified mature naive B220+ /CD19+ /IgM+ /IgD+ B cells improve healing of acute and diabetic murine wounds after a single topical application. B cell treatment significantly accelerated acute wound closure by 2-3 days in wild-type mice and 5-6 days in obese diabetic mice. The treatment led to full closure in 43% of chronic diabetic wounds, as compared to only 5% in saline-treated controls. Applying equivalent numbers of T cells or disrupted B cells failed to reproduce these effects, indicating that live B cells mediated pro-healing responses. Topically applied B cell treatment was associated with significantly reduced scar size, increased collagen deposition and maturation, enhanced angiogenesis, and increased nerve growth into and under the healing wound. β-III tubulin+ nerve endings in scars of wounds treated acutely with B cells showed increased relative expression of growth-associated protein 43. The improved healing associated with B cell treatment was supported by significantly increased fibroblast proliferation and decreased apoptosis in the wound bed and edges, altered kinetics of neutrophil infiltration, as well as an increase in TGF-β and a significant reduction in MMP2 expression in wound granulation tissue. Our findings indicate that the timeline and efficacy of wound healing can be experimentally manipulated through the direct application of mature, naive B cells, which effectively modify the balance of mature immune cell populations within the wound microenvironment and accelerate the healing process.
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Affiliation(s)
- Ruxandra F Sîrbulescu
- Vaccine and Immunotherapy Center, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Chloe K Boehm
- Vaccine and Immunotherapy Center, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Erin Soon
- Vaccine and Immunotherapy Center, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Moses Q Wilks
- Gordon Center for Medical Imaging, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Iulian Ilieş
- Healthcare Systems Engineering Institute, Department of Mechanical and Industrial Engineering, College of Engineering, Northeastern University, Boston, Massachusetts
| | - Hushan Yuan
- Gordon Center for Medical Imaging, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ben Maxner
- Vaccine and Immunotherapy Center, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Nicolas Chronos
- Vaccine and Immunotherapy Center, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Charalambos Kaittanis
- Gordon Center for Medical Imaging, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Dennis P Orgill
- Division of Plastic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ann E Sluder
- Vaccine and Immunotherapy Center, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Mark C Poznansky
- Vaccine and Immunotherapy Center, Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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65
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The Spleen: A Hub Connecting Nervous and Immune Systems in Cardiovascular and Metabolic Diseases. Int J Mol Sci 2017; 18:ijms18061216. [PMID: 28590409 PMCID: PMC5486039 DOI: 10.3390/ijms18061216] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 05/30/2017] [Accepted: 06/02/2017] [Indexed: 12/14/2022] Open
Abstract
Metabolic disorders have been identified as major health problems affecting a large portion of the world population. In addition, obesity and insulin resistance are principal risk factors for the development of cardiovascular diseases. Altered immune responses are common features of both hypertension and obesity and, moreover, the involvement of the nervous system in the modulation of immune system is gaining even more attention in both pathophysiological contexts. For these reasons, during the last decades, researches focused their efforts on the comprehension of the molecular mechanisms connecting immune system to cardiovascular and metabolic diseases. On the other hand, it has been reported that in these pathological conditions, central neural pathways modulate the activity of the peripheral nervous system, which is strongly involved in onset and progression of the disease. It is interesting to notice that neural reflex can also participate in the modulation of immune functions. In this scenario, the spleen becomes the crucial hub allowing the interaction of different systems differently involved in metabolic and cardiovascular diseases. Here, we summarize the major findings that dissect the role of the immune system in disorders related to metabolic and cardiovascular dysfunctions, and how this could also be influenced by neural reflexes.
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66
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Li L, Duan M, Chen W, Jiang A, Li X, Yang J, Li Z. The spleen in liver cirrhosis: revisiting an old enemy with novel targets. J Transl Med 2017; 15:111. [PMID: 28535799 PMCID: PMC5442653 DOI: 10.1186/s12967-017-1214-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 05/16/2017] [Indexed: 12/15/2022] Open
Abstract
The spleen is a secondary lymphoid organ which can influence the progression of multiple diseases, notably liver cirrhosis. In chronic liver diseases, splenomegaly and hypersplenism can manifest following the development of portal hypertension. These splenic abnormalities correlate with and have been postulated to facilitate the progression of liver fibrosis to cirrhosis, although precise mechanisms remain poorly understood. In this review, we summarize the literature to highlight the mechanistic contributions of splenomegaly and hypersplenism to the development of liver cirrhosis, focusing on three key aspects: hepatic fibrogenesis, hepatic immune microenvironment dysregulation and liver regeneration. We conclude with a discussion of the possible therapeutic strategies for modulating splenic abnormalities, including the novel potential usage of nanomedicine in non-surgically targetting splenic disorders for the treatment of liver cirrhosis.
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Affiliation(s)
- Liang Li
- National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China.,Liver and Spleen Diseases Research Center, Shaanxi Province, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Mubing Duan
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Bundoora, VIC, Australia
| | - Weisan Chen
- National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Bundoora, VIC, Australia
| | - An Jiang
- National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China.,Liver and Spleen Diseases Research Center, Shaanxi Province, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China.,Department of General Surgery, The Second Affiliated Hospital, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Xiaoming Li
- National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Jun Yang
- National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China. .,Liver and Spleen Diseases Research Center, Shaanxi Province, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China. .,Department of Pathology, The Second Affiliated Hospital, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China.
| | - Zongfang Li
- National & Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital, Xi'an Jiaotong University, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China. .,Liver and Spleen Diseases Research Center, Shaanxi Province, No.157, Xiwu Road, Xi'an, 710004, Shaanxi, China.
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67
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Hoover DB. Cholinergic modulation of the immune system presents new approaches for treating inflammation. Pharmacol Ther 2017; 179:1-16. [PMID: 28529069 DOI: 10.1016/j.pharmthera.2017.05.002] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The nervous system and immune system have broad and overlapping distributions in the body, and interactions of these ubiquitous systems are central to the field of neuroimmunology. Over the past two decades, there has been explosive growth in our understanding of neuroanatomical, cellular, and molecular mechanisms that mediate central modulation of immune functions through the autonomic nervous system. A major catalyst for growth in this field was the discovery that vagal nerve stimulation (VNS) caused a prominent attenuation of the systemic inflammatory response evoked by endotoxin in experimental animals. This effect was mediated by acetylcholine (ACh) stimulation of nicotinic receptors on splenic macrophages. Hence, the circuit was dubbed the "cholinergic anti-inflammatory pathway". Subsequent work identified the α7 nicotinic ACh receptor (α7nAChR) as the crucial target for attenuation of pro-inflammatory cytokine release from macrophages and dendritic cells. Further investigation made the important discovery that cholinergic T cells within the spleen and not cholinergic nerve cells were the source of ACh that stimulated α7 receptors on splenic macrophages. Given the important role that inflammation plays in numerous disease processes, cholinergic anti-inflammatory mechanisms are under intensive investigation from a basic science perspective and in translational studies of animal models of diseases such as inflammatory bowel disease and rheumatoid arthritis. This basic work has already fostered several clinical trials examining the efficacy of VNS and cholinergic therapeutics in human inflammatory diseases. This review provides an overview of basic and translational aspects of the cholinergic anti-inflammatory response and relevant pharmacology of drugs acting at the α7nAChR.
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Affiliation(s)
- Donald B Hoover
- Department of Biomedical Sciences and Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.
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68
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Eldahan KC, Rabchevsky AG. Autonomic dysreflexia after spinal cord injury: Systemic pathophysiology and methods of management. Auton Neurosci 2017; 209:59-70. [PMID: 28506502 DOI: 10.1016/j.autneu.2017.05.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/30/2017] [Accepted: 05/03/2017] [Indexed: 12/11/2022]
Abstract
Traumatic spinal cord injury (SCI) has widespread physiological effects beyond the disruption of sensory and motor function, notably the loss of normal autonomic and cardiovascular control. Injury at or above the sixth thoracic spinal cord segment segregates critical spinal sympathetic neurons from supraspinal modulation which can result in a syndrome known as autonomic dysreflexia (AD). AD is defined as episodic hypertension and concomitant baroreflex-mediated bradycardia initiated by unmodulated sympathetic reflexes in the decentralized cord. This condition is often triggered by noxious yet unperceived visceral or somatic stimuli below the injury level and if severe enough can require immediate medical attention. Herein, we review the pathophysiological mechanisms germane to the development of AD, including maladaptive plasticity of neural circuits mediating abnormal sympathetic reflexes and hypersensitization of peripheral vasculature that collectively contribute to abnormal hemodynamics after SCI. Further, we discuss the systemic effects of recurrent AD and pharmacological treatments used to manage such episodes. Contemporary research avenues are then presented to better understand the relative contributions of underlying mechanisms and to elucidate the effects of recurring AD on cardiovascular and immune functions for developing more targeted and effective treatments to attenuate the development of this insidious syndrome following high-level SCI.
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Affiliation(s)
- Khalid C Eldahan
- Department of Physiology, University of Kentucky, Lexington, KY 40536, United States; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, United States
| | - Alexander G Rabchevsky
- Department of Physiology, University of Kentucky, Lexington, KY 40536, United States; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, United States.
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69
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Greco SJ, Yehia G, Potian JA, Molina CA, Rameshwar P. Constitutive Expression of Inducible Cyclic Adenosine Monophosphate Early Repressor (ICER) in Cycling Quiescent Hematopoietic Cells: Implications for Aging Hematopoietic Stem Cells. Stem Cell Rev Rep 2016; 13:116-126. [PMID: 27822872 DOI: 10.1007/s12015-016-9701-5] [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: 12/01/2022]
Abstract
Despite extensive insights on the interaction between hematopoietic stem cells (HSCs) and the supporting bone marrow (BM) stroma in hematopoietic homeostasis there remains unanswered questions on HSC regulation. We report on the mechanism by which HSCs attain cycling quiescence by addressing a role for inducible cyclic AMP early repressor (ICER). ICER negatively transcriptional regulators of cAMP activators such as CREM and CREB. These activators can be induced by hematopoietic stimulators such as cytokines. We isolated subsets of hematopoietic cells from ten healthy donors: CD34+CD38-/c-kit + (primitive progenitor), CD34+CD38+/c-kitlow (mature progenitor) and CD34-CD38+/-/c-kitlow/- (differentiated lineage-). The relative maturity of the progenitors were verified in long-term culture initiating assay. Immunoprecipitation indicated the highest level of ICER in the nuclear extracts of CD34+/CD38- cells. Phospho (p)-CREM was also present suggesting a balance between ICER and p-CREM in HSC. ICER seems to be responsible for decrease in G1 transition, based on reduced Cdk4 protein, decreased proliferation and functional studies with propidium iodide. There were no marked changes in the cycling inhibitors, p15 and p-Rb, suggesting that ICER may act independently of other cycling inhibitors. The major effects of ICER were validated with BM mononuclear cells (BMNCs) in which ICER was ectopically expressed, and with BMNCs resistant to 5-fluorouracil- or cyclophosphamide. In total, this study ascribes a novel role for ICER in G1 checkpoint regulation in HSCs. These findings are relevant to gene therapy that require engineering of HSCs, age-related disorders that are associated with hematopoietic dysfunction and other hematological disorders.
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Affiliation(s)
- Steven J Greco
- Department of Medicine, Division of Hematology-Oncology, New Jersey Medical School, Rutgers School of Biomedical Health Science, Newark, NJ, 07103, USA
| | - Ghassan Yehia
- Office of Research Advancement, Rutgers University, New Brunswick, USA
| | - Julius A Potian
- Department of Medicine, Division of Hematology-Oncology, New Jersey Medical School, Rutgers School of Biomedical Health Science, Newark, NJ, 07103, USA
| | - Carlos A Molina
- Department of Biology and Molecular Biology, Montclair University, Montclair, NJ, USA
| | - Pranela Rameshwar
- Department of Medicine, Division of Hematology-Oncology, New Jersey Medical School, Rutgers School of Biomedical Health Science, Newark, NJ, 07103, USA.
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