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Al-Bkoor T, Ata F, Bint I Bilal A, Abdulgayoom M, Cherif H, Surchi H. Post-Thymectomy Autoimmune Flare-Up With New-Onset Type 1 Diabetes Mellitus. JCEM CASE REPORTS 2024; 2:luae039. [PMID: 38524389 PMCID: PMC10958770 DOI: 10.1210/jcemcr/luae039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Indexed: 03/26/2024]
Abstract
The thymus gland aids in the maturation of the immune system. An overactive or malfunctioning thymus gland, as seen in thymomas, can lead to disrupted immune systems. Thymectomy, the usual treatment, can paradoxically lead to further derangements in the immune system, leading to new autoimmune disorders. Most of these reported disorders are rheumatological. Except preclinical studies, there are no reported cases of autoimmune diabetes post-thymectomy. A 25-year-old woman who had malignant thymoma underwent chemotherapy, followed by thymectomy and radiotherapy. She developed autoimmune diabetes mellitus (AID) approximately 1 year post-thymectomy, evident from raised glycated hemoglobin, anti-glutamic acid decarboxylase (GAD) antibodies, ineffectiveness of oral glucose-lowering agents, and positive response to insulin. AID can occur after thymectomy, as evidenced by animal studies and this case report. Whether these patients would have long-term outcomes and control of diabetes differently than classic type 1 diabetes mellitus (T1D) is uncertain. Further research is needed to prove causality between thymectomy and diabetes.
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Affiliation(s)
- Tareq Al-Bkoor
- Department of Internal Medicine, Hamad Medical Corporation, Doha, Qatar
| | - Fateen Ata
- Department of Endocrinology and Metabolism, Hamad Medical Corporation, Doha, Qatar
| | | | | | - Honar Cherif
- Department of Hematology, Hamad Medical Corporation, Doha, Qatar
| | - Haval Surchi
- Department of Endocrinology and Metabolism, Hamad Medical Corporation, Doha, Qatar
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2
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What's the role of thymus in diabetes mellitus? Int Immunopharmacol 2023; 116:109765. [PMID: 36702074 DOI: 10.1016/j.intimp.2023.109765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/17/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023]
Abstract
Diabetes mellitus is considered as an autoimmune inflammatory and age-related disease. As an important immune organ, the thymus is involved in the immune response and inflammatory response process. Therefore, there may be a link between changes in thymus function and diabetes. Based on previous studies, we hypothesized that thymus dysfunction due to aging and other reasons leads to changes in the generation of various inflammatory-immune cells and inflammatory cytokines that regulate insulin resistance, and then participates in the development of diabetes and its complications. Therefore, thymus may be a key factor in diabetes and complications, and it may be a promising therapeutic strategy to improve the thymus function for patients with diabetes. The purpose of this review is to summarize and discuss recent advances in the influence of thymus function on diabetes, especially its potential mechanisms.
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3
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Tanoey J, Baechle C, Brenner H, Deckert A, Fricke J, Günther K, Karch A, Keil T, Kluttig A, Leitzmann M, Mikolajczyk R, Obi N, Pischon T, Schikowski T, Schipf SM, Schulze MB, Sedlmeier A, Moreno Velásquez I, Weber KS, Völzke H, Ahrens W, Gastell S, Holleczek B, Jöckel KH, Katzke V, Lieb W, Michels KB, Schmidt B, Teismann H, Becher H. Birth Order, Caesarean Section, or Daycare Attendance in Relation to Child- and Adult-Onset Type 1 Diabetes: Results from the German National Cohort. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:10880. [PMID: 36078596 PMCID: PMC9517906 DOI: 10.3390/ijerph191710880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/25/2022] [Accepted: 08/27/2022] [Indexed: 06/15/2023]
Abstract
(1) Background: Global incidence of type 1 diabetes (T1D) is rising and nearly half occurred in adults. However, it is unclear if certain early-life childhood T1D risk factors were also associated with adult-onset T1D. This study aimed to assess associations between birth order, delivery mode or daycare attendance and type 1 diabetes (T1D) risk in a population-based cohort and whether these were similar for childhood- and adult-onset T1D (cut-off age 15); (2) Methods: Data were obtained from the German National Cohort (NAKO Gesundheitsstudie) baseline assessment. Self-reported diabetes was classified as T1D if: diagnosis age ≤ 40 years and has been receiving insulin treatment since less than one year after diagnosis. Cox regression was applied for T1D risk analysis; (3) Results: Analyses included 101,411 participants (100 childhood- and 271 adult-onset T1D cases). Compared to "only-children", HRs for second- or later-born individuals were 0.70 (95% CI = 0.50-0.96) and 0.65 (95% CI = 0.45-0.94), respectively, regardless of parental diabetes, migration background, birth year and perinatal factors. In further analyses, higher birth order reduced T1D risk in children and adults born in recent decades. Caesarean section and daycare attendance showed no clear associations with T1D risk; (4) Conclusions: Birth order should be considered in both children and adults' T1D risk assessment for early detection.
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Affiliation(s)
- Justine Tanoey
- Institute of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Christina Baechle
- Institute for Biometrics and Epidemiology, German Diabetes Center (DDZ), Leibniz Institute for Diabetes Research, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Hermann Brenner
- Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Andreas Deckert
- Heidelberg Institute of Global Health, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Julia Fricke
- Institute of Social Medicine, Epidemiology and Health Economics, Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Kathrin Günther
- Leibniz Institute for Prevention Research and Epidemiology—BIPS, 28359 Bremen, Germany
| | - André Karch
- Institute for Epidemiology and Social Medicine, Albert-Schweitzer-Campus 1, Building D3, 48149 Münster, Germany
| | - Thomas Keil
- Institute of Social Medicine, Epidemiology and Health Economics, Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany
- Institute of Clinical Epidemiology and Biometry, University of Würzburg, 97080 Würzburg, Germany
- State Institute of Health, Bavarian Health and Food Safety Authority, 91058 Erlangen, Germany
| | - Alexander Kluttig
- Institute for Medical Epidemiology, Biometrics and Informatics, Interdisciplinary Center for Health Sciences, Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
| | - Michael Leitzmann
- Department for Epidemiology and Preventive Medicine, Regensburg University Medical Center, 93053 Regensburg, Germany
| | - Rafael Mikolajczyk
- Institute for Medical Epidemiology, Biometrics and Informatics, Interdisciplinary Center for Health Sciences, Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
| | - Nadia Obi
- Institute of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Tobias Pischon
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Molecular Epidemiology Research Group, 13125 Berlin, Germany
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Biobank Technology Platform, 13125 Berlin, Germany
- Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Tamara Schikowski
- Leibniz Research Institute for Environmental Medicine—IUF, 40225 Düsseldorf, Germany
| | - Sabine M. Schipf
- Institute for Community Medicine, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Matthias B. Schulze
- German Institute of Human Nutrition Potsdam-Rehbruecke, 14558 Nuthetal, Germany
- Institute of Nutritional Science, University of Potsdam, 14558 Nuthetal, Germany
| | - Anja Sedlmeier
- Department for Epidemiology and Preventive Medicine, Regensburg University Medical Center, 93053 Regensburg, Germany
| | - Ilais Moreno Velásquez
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Molecular Epidemiology Research Group, 13125 Berlin, Germany
| | | | - Henry Völzke
- Institute for Community Medicine, University Medicine Greifswald, 17489 Greifswald, Germany
| | - Wolfgang Ahrens
- Leibniz Institute for Prevention Research and Epidemiology—BIPS, 28359 Bremen, Germany
| | - Sylvia Gastell
- German Institute of Human Nutrition Potsdam-Rehbruecke, 14558 Nuthetal, Germany
| | - Bernd Holleczek
- Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Karl-Heinz Jöckel
- Institute of Medical Informatics, Biometry und Epidemiology, Essen University Hospital, 45147 Essen, Germany
| | - Verena Katzke
- Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Wolfgang Lieb
- Institute of Epidemiology, Kiel University, 24105 Kiel, Germany
| | - Karin B. Michels
- Institute for Prevention and Cancer Epidemiology, Faculty of Medicine and Medical Center, University of Freiburg, 79110 Freiburg, Germany
| | - Börge Schmidt
- Institute of Medical Informatics, Biometry und Epidemiology, Essen University Hospital, 45147 Essen, Germany
| | - Henning Teismann
- Institute for Epidemiology and Social Medicine, Albert-Schweitzer-Campus 1, Building D3, 48149 Münster, Germany
| | - Heiko Becher
- Institute of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
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4
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Abstract
The conventional perception asserts that immunology is the science of ‘discrimination’ between self and non-self. This concept is however no longer tenable as effector cells of the adaptive immune system are first conditioned to be tolerant to the body’s own antigens, collectively known as self until now. Only then attain these effectors the responsiveness to non-self. The acquisition of this essential state of tolerance to self occurs for T cells in the thymus, the last major organ of our body that revealed its intricate function in health and disease. The ‘thymus’ as an anatomical notion was first notably documented in Ancient Greece although our present understanding of the organ’s functions was only deciphered commencing in the 1960s. In the late 1980s, the thymus was identified as the site where clones of cells reactive to self, termed ‘forbidden’ thymocytes, are physically depleted as the result of a process now known as negative selection. The recognition of this mechanism further contributed to the belief that the central rationale of immunology as a science lies in the distinction between self and non-self. This review will discuss the evidence that the thymus serves as a unique lymphoid organ able to instruct T cells to recognize and be tolerant to harmless self before adopting the capacity to defend the body against potentially injurious non-self-antigens presented in the context of different challenges from infections to exposure to malignant cells. The emerging insight into the thymus’ cardinal functions now also provides an opportunity to exploit this knowledge to develop novel strategies that specifically prevent or even treat organ-specific autoimmune diseases.
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Presa M, Racine JJ, Dwyer JR, Lamont DJ, Ratiu JJ, Sarsani VK, Chen YG, Geurts A, Schmitz I, Stearns T, Allocco J, Chapman HD, Serreze DV. A Hypermorphic Nfkbid Allele Contributes to Impaired Thymic Deletion of Autoreactive Diabetogenic CD8 + T Cells in NOD Mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 201:1907-1917. [PMID: 30127089 PMCID: PMC6143397 DOI: 10.4049/jimmunol.1800465] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 07/23/2018] [Indexed: 11/19/2022]
Abstract
In both NOD mice and humans, the development of type 1 diabetes (T1D) is dependent in part on autoreactive CD8+ T cells recognizing pancreatic β cell peptides presented by often quite common MHC class I variants. Studies in NOD mice previously revealed that the common H2-Kd and/or H2-Db class I molecules expressed by this strain aberrantly lose the ability to mediate the thymic deletion of pathogenic CD8+ T cell responses through interactions with T1D susceptibility genes outside the MHC. A gene(s) mapping to proximal chromosome 7 was previously shown to be an important contributor to the failure of the common class I molecules expressed by NOD mice to mediate the normal thymic negative selection of diabetogenic CD8+ T cells. Using an inducible model of thymic negative selection and mRNA transcript analyses, we initially identified an elevated Nfkbid expression variant as a likely NOD-proximal chromosome 7 region gene contributing to impaired thymic deletion of diabetogenic CD8+ T cells. CRISPR/Cas9-mediated genetic attenuation of Nfkbid expression in NOD mice resulted in improved negative selection of autoreactive diabetogenic AI4 and NY8.3 CD8+ T cells. These results indicated that allelic variants of Nfkbid contribute to the efficiency of intrathymic deletion of diabetogenic CD8+ T cells. However, although enhancing thymic deletion of pathogenic CD8+ T cells, ablating Nfkbid expression surprisingly accelerated T1D onset that was associated with numeric decreases in both regulatory T and B lymphocytes in NOD mice.
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Affiliation(s)
| | | | | | | | | | | | | | - Aron Geurts
- Medical College of Wisconsin, Milwaukee, WI 53226
| | - Ingo Schmitz
- Systems-Oriented Immunology and Inflammation Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; and
- Institute of Molecular and Clinical Immunology, Otto-von-Guericke University, 39120 Magdeburg, Germany
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6
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Mendes-da-Cruz DA, Lemos JP, Passos GA, Savino W. Abnormal T-Cell Development in the Thymus of Non-obese Diabetic Mice: Possible Relationship With the Pathogenesis of Type 1 Autoimmune Diabetes. Front Endocrinol (Lausanne) 2018; 9:381. [PMID: 30050502 PMCID: PMC6052664 DOI: 10.3389/fendo.2018.00381] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 06/22/2018] [Indexed: 12/20/2022] Open
Abstract
Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of insulin-producing cells in the pancreas, by direct interactions with autoreactive pancreas infiltrating T lymphocytes (PILs). One of the most important animal models for this disease is the non-obese diabetic (NOD) mouse. Alterations in the NOD mouse thymus during the pathogenesis of the disease have been reported. From the initial migratory disturbances to the accumulation of mature thymocytes, including regulatory Foxp3+ T cells, important mechanisms seem to regulate the repertoire of T cells that leave the thymus to settle in peripheral lymphoid organs. A significant modulation of the expression of extracellular matrix and soluble chemoattractant molecules, in addition to integrins and chemokine receptors, may contribute to the progressive accumulation of mature thymocytes and consequent formation of giant perivascular spaces (PVS) that are observed in the NOD mouse thymus. Comparative large-scale transcriptional expression and network analyses involving mRNAs and miRNAs of thymocytes, peripheral T CD3+ cells and PILs provided evidence that in PILs chemokine receptors and mRNAs are post-transcriptionally regulated by miR-202-3p resulting in decreased activity of these molecules during the onset of T1D in NOD mice. In this review, we discuss the abnormal T-cell development in NOD mice in the context of intrathymic expression of different migration-related molecules, peptides belonging to the family of insulin and insulin-like growth factors as well as the participation of miRNAs as post-transcriptional regulators and their possible influence on the onset of aggressive autoimmunity during the pathogenesis of T1D.
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Affiliation(s)
- Daniella A. Mendes-da-Cruz
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Julia P. Lemos
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Geraldo A. Passos
- Department of Morphology, Physiology and Basic Pathology, Ribeirão Preto Medical School, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Wilson Savino
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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7
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Junjappa RP, Patil P, Bhattarai KR, Kim HR, Chae HJ. IRE1α Implications in Endoplasmic Reticulum Stress-Mediated Development and Pathogenesis of Autoimmune Diseases. Front Immunol 2018; 9:1289. [PMID: 29928282 PMCID: PMC5997832 DOI: 10.3389/fimmu.2018.01289] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 05/22/2018] [Indexed: 12/15/2022] Open
Abstract
Inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α) is the most prominent and evolutionarily conserved endoplasmic reticulum (ER) membrane protein. This transduces the signal of misfolded protein accumulation in the ER, named as ER stress, to the nucleus as “unfolded protein response (UPR).” The ER stress-mediated IRE1α signaling pathway arbitrates the yin and yang of cell life. IRE1α has been implicated in several physiological as well as pathological conditions, including immune disorders. Autoimmune diseases are caused by abnormal immune responses that develop due to genetic mutations and several environmental factors, including infections and chemicals. These factors dysregulate the cell immune reactions, such as cytokine secretion, antigen presentation, and autoantigen generation. However, the mechanisms involved, in which these factors induce the onset of autoimmune diseases, are remaining unknown. Considering that these environmental factors also induce the UPR, which is expected to have significant role in secretory cells and immune cells. The role of the major UPR molecule, IRE1α, in causing immune responses is well identified, but its role in inducing autoimmunity and the pathogenesis of autoimmune diseases has not been clearly elucidated. Hence, a better understanding of the role of IRE1α and its regulatory mechanisms in causing autoimmune diseases could help to identify and develop the appropriate therapeutic strategies. In this review, we mainly center the discussion on the molecular mechanisms of IRE1α in the pathophysiology of autoimmune diseases.
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Affiliation(s)
- Raghu Patil Junjappa
- Department of Pharmacology, School of Medicine, Institute of New Drug Development, Chonbuk National University, Jeonju, South Korea
| | - Prakash Patil
- Department of Pharmacology, School of Medicine, Institute of New Drug Development, Chonbuk National University, Jeonju, South Korea
| | - Kashi Raj Bhattarai
- Department of Pharmacology, School of Medicine, Institute of New Drug Development, Chonbuk National University, Jeonju, South Korea
| | - Hyung-Ryong Kim
- Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Han-Jung Chae
- Department of Pharmacology, School of Medicine, Institute of New Drug Development, Chonbuk National University, Jeonju, South Korea
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8
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Csaba G. The Role of Brain –Pineal –Thymus System in the Determination of Lifespan: The Autoimmune Aging Theory. ACTA ACUST UNITED AC 2017. [DOI: 10.3233/nib-160118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- G. Csaba
- Department of Genetics, Cell and Immunobiology, Semmelweis University, Budapest, Hungary
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9
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Marré ML, Piganelli JD. Environmental Factors Contribute to β Cell Endoplasmic Reticulum Stress and Neo-Antigen Formation in Type 1 Diabetes. Front Endocrinol (Lausanne) 2017; 8:262. [PMID: 29033899 PMCID: PMC5626851 DOI: 10.3389/fendo.2017.00262] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 09/20/2017] [Indexed: 12/16/2022] Open
Abstract
Type 1 diabetes (T1D) is an autoimmune disease in which immune-mediated targeting and destruction of insulin-producing pancreatic islet β cells leads to chronic hyperglycemia. There are many β cell proteins that are targeted by autoreactive T cells in their native state. However, recent studies have demonstrated that many β cell proteins are recognized as neo-antigens following posttranslational modification (PTM). Although modified neo-antigens are well-established targets of pathology in other autoimmune diseases, the effects of neo-antigens in T1D progression and the mechanisms by which they are generated are not well understood. We have demonstrated that PTM occurs during endoplasmic reticulum (ER) stress, a process to which β cells are uniquely susceptible due to the high rate of insulin production in response to dynamic glucose sensing. In the context of genetic susceptibility to autoimmunity, presentation of these modified neo-antigens may activate autoreactive T cells and cause pathology. However, inherent β cell ER stress and protein PTM do not cause T1D in every genetically susceptible individual, suggesting the contribution of additional factors. Indeed, many environmental factors, such as viral infection, chemicals, or inflammatory cytokines, are associated with T1D onset, but the mechanisms by which these factors lead to disease onset remain unknown. Since these environmental factors also cause ER stress, exposure to these factors may enhance production of neo-antigens, therefore boosting β cell recognition by autoreactive T cells and exacerbating T1D pathogenesis. Therefore, the combined effects of physiological ER stress and the stress that is induced by environmental factors may lead to breaks in peripheral tolerance, contribute to antigen spread, and hasten disease onset. This Hypothesis and Theory article summarizes what is currently known about ER stress and protein PTM in autoimmune diseases including T1D and proposes a role for environmental factors in breaking immune tolerance to β cell antigens through neo-antigen formation.
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Affiliation(s)
- Meghan L Marré
- Division of Pediatric Surgery, Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jon D Piganelli
- Division of Pediatric Surgery, Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA, United States
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10
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Askenasy N. Mechanisms of diabetic autoimmunity: II--Is diabetes a central or peripheral disorder of effector and regulatory cells? Immunol Res 2016; 64:36-43. [PMID: 26482052 DOI: 10.1007/s12026-015-8725-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Two competing hypotheses aiming to explain the onset of autoimmune reactions are discussed in the context of genetic and environmental predisposition to type 1 diabetes (T1D). The first hypothesis has evolved along characterization of the mechanisms of self-discrimination and attributes diabetic autoimmunity to escape of reactive T cells from central regulation in the thymus. The second considers frequent occurrence of autoimmune reactions within the immune homunculus, which are adequately suppressed by regulatory T cells originating from the thymus, and occasionally, insufficient suppression results in autoimmunity. Besides thymic dysfunction, deregulation of both effector and suppressor cells can in fact result from homeostatic aberrations at the peripheral level during initial stages of evolution of adaptive immunity. Pathogenic cells sensitized in the islets are efficiently expanded in the target tissue and pancreatic lymph nodes of lymphopenic neonates. In parallel, the same mechanisms of peripheral sensitization contribute to tolerization through education of naïve/effector T cells and expansion of regulatory T cells. Experimental evidence presented for each individual mechanism implies that T1D may result from a primary effector or suppressor immune abnormality. Disturbed self-tolerance leading to T1D may well result from peripheral deregulation of innate and adaptive immunity, with variable contribution of central thymic dysfunction.
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11
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Parackova Z, Kayserova J, Danova K, Sismova K, Dudkova E, Sumnik Z, Kolouskova S, Lebl J, Stechova K, Sediva A. T regulatory lymphocytes in type 1 diabetes: Impaired CD25 expression and IL-2 induced STAT5 phosphorylation in pediatric patients. Autoimmunity 2016; 49:523-531. [PMID: 27560779 DOI: 10.1080/08916934.2016.1217998] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
T regulatory cells (Tregs) are essential for maintaining tolerance and preventing autoimmune diseases, such as type 1 diabetes (T1D). In our study, we investigated CD25 + FoxP3 + Tregs and thymic FoxP3 + Helios + Tregs in large cohorts of children with T1D at onset and with long-term T1D, and further in their relatives and healthy controls. We observed significantly decreased numbers of CD25 + FoxP3 + Tregs, but not FoxP3 + Helios + Tregs, in long-term patients compared with the control group and T1D onset. Furthermore, long-term T1D patients exhibited highly significant decrease of CD25 expression on both CD25 + FoxP3 + Tregs and FoxP3 + Helios + Tregs, independently on age or the duration of diabetes. A similar reduction of CD25 expression was also found in T1D relatives, more significant in those with positive autoantibodies. Low CD25 expression was associated with impaired signal transducer and activator of transcription 5 (STAT5) phosphorylation after IL-2 exposure. Our results show that the frequency of Tregs is altered in a large cohort of long-term T1D patients, a profound decrease in CD25 expression and altered IL-2 signaling are typical features of Tregs populations in long-term diabetic patients and their relatives.
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Affiliation(s)
| | | | - Klara Danova
- a Department of Immunology.,d Sotio a.c. , Prague , Czech Republic
| | | | | | | | | | - Jan Lebl
- b Department of Pediatrics , and
| | - Katerina Stechova
- c Department of Internal Medicine , Charles University, 2nd Faculty of Medicine, University Hospital Motol , Prague , Czech Republic , and
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12
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Marré ML, Profozich JL, Coneybeer JT, Geng X, Bertera S, Ford MJ, Trucco M, Piganelli JD. Inherent ER stress in pancreatic islet β cells causes self-recognition by autoreactive T cells in type 1 diabetes. J Autoimmun 2016; 72:33-46. [PMID: 27173406 DOI: 10.1016/j.jaut.2016.04.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/25/2016] [Accepted: 04/30/2016] [Indexed: 01/10/2023]
Abstract
Type 1 diabetes (T1D) is an autoimmune disease characterized by pancreatic β cell destruction induced by islet reactive T cells that have escaped central tolerance. Many physiological and environmental triggers associated with T1D result in β cell endoplasmic reticulum (ER) stress and dysfunction, increasing the potential for abnormal post-translational modification (PTM) of proteins. We hypothesized that β cell ER stress induced by environmental and physiological conditions generates abnormally-modified proteins for the T1D autoimmune response. To test this hypothesis we exposed the murine CD4(+) diabetogenic BDC2.5 T cell clone to murine islets in which ER stress had been induced chemically (Thapsigargin). The BDC2.5 T cell IFNγ response to these cells was significantly increased compared to non-treated islets. This β cell ER stress increased activity of the calcium (Ca(2+))-dependent PTM enzyme tissue transglutaminase 2 (Tgase2), which was necessary for full stress-dependent immunogenicity. Indeed, BDC2.5 T cells responded more strongly to their antigen after its modification by Tgase2. Finally, exposure of non-antigenic murine insulinomas to chemical ER stress in vitro or physiological ER stress in vivo caused increased ER stress and Tgase2 activity, culminating in higher BDC2.5 responses. Thus, β cell ER stress induced by chemical and physiological triggers leads to β cell immunogenicity through Ca(2+)-dependent PTM. These findings elucidate a mechanism of how β cell proteins are modified and become immunogenic, and reveal a novel opportunity for preventing β cell recognition by autoreactive T cells.
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MESH Headings
- Amino Acid Sequence
- Animals
- Autoantigens/genetics
- Autoantigens/immunology
- Autoimmunity/genetics
- Autoimmunity/immunology
- Blotting, Western
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- Calcium/immunology
- Calcium/metabolism
- Cell Line
- Cells, Cultured
- Chromogranin A/genetics
- Chromogranin A/immunology
- Chromogranin A/metabolism
- Diabetes Mellitus, Type 1/genetics
- Diabetes Mellitus, Type 1/immunology
- Diabetes Mellitus, Type 1/metabolism
- Endoplasmic Reticulum Stress/genetics
- Endoplasmic Reticulum Stress/immunology
- GTP-Binding Proteins/genetics
- GTP-Binding Proteins/immunology
- GTP-Binding Proteins/metabolism
- Humans
- Insulin-Secreting Cells/immunology
- Insulin-Secreting Cells/metabolism
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, SCID
- Models, Immunological
- Protein Glutamine gamma Glutamyltransferase 2
- Protein Processing, Post-Translational/immunology
- Reverse Transcriptase Polymerase Chain Reaction
- Tandem Mass Spectrometry
- Transglutaminases/genetics
- Transglutaminases/immunology
- Transglutaminases/metabolism
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Affiliation(s)
- Meghan L Marré
- Division of Immunogenetics, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Jennifer L Profozich
- Division of Immunogenetics, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Jorge T Coneybeer
- Division of Immunogenetics, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Xuehui Geng
- Division of Immunogenetics, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Suzanne Bertera
- Division of Immunogenetics, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Michael J Ford
- MS Bioworks, LLC, 3950 Varsity Drive, Ann Arbor, MI 48108, USA
| | - Massimo Trucco
- Division of Immunogenetics, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Jon D Piganelli
- Division of Immunogenetics, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA 15224, USA.
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13
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Julián MT, Alonso N, Colobran R, Sánchez A, Miñarro A, Pujol-Autonell I, Carrascal J, Rodríguez-Fernández S, Ampudia RM, Vives-Pi M, Puig-Domingo M. CD26/DPPIV inhibition alters the expression of immune response-related genes in the thymi of NOD mice. Mol Cell Endocrinol 2016; 426:101-12. [PMID: 26911933 DOI: 10.1016/j.mce.2016.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 02/15/2016] [Accepted: 02/15/2016] [Indexed: 12/22/2022]
Abstract
The transmembrane glycoprotein CD26 or dipeptidyl peptidase IV (DPPIV) is a multifunctional protein. In immune system, CD26 plays a role in T-cell function and is also involved in thymic maturation and emigration patterns. In preclinical studies, treatment with DPPIV inhibitors reduces insulitis and delays or even reverses the new -onset of type 1 diabetes (T1D) in non-obese diabetic (NOD) mice. However, the specific mechanisms involved in these effects remain unknown. The aim of the present study was to investigate how DPPIV inhibition modifies the expression of genes in the thymus of NOD mice by microarray analysis. Changes in the gene expression of β-cell autoantigens and Aire in thymic epithelial cells (TECs) were also evaluated by using qRT-PCR. A DPPIV inhibitor, MK626, was orally administered in the diet for 4 and 6 weeks starting at 6-8 weeks of age. Thymic glands from treated and control mice were obtained for each study checkpoint. Thymus transcriptome analysis revealed that 58 genes were significantly over-expressed in MK626-treated mice after 6 weeks of treatment. Changes in gene expression in the thymus were confined mainly to the immune system, including innate immunity, chemotaxis, antigen presentation and immunoregulation. Most of the genes are implicated in central tolerance mechanisms through several pathways. No differences were observed in the expression of Aire and β-cell autoantigens in TECs. In the current study, we demonstrate that treatment with the DPPIV inhibitor MK626 in NOD mice alters the expression of the immune response-related genes in the thymus, especially those related to immunological central tolerance, and may contribute to the prevention of T1D.
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Affiliation(s)
- María Teresa Julián
- Department of Endocrinology and Nutrition, Germans Trias i Pujol Health Sciences Research Institute and Hospital, 08916, Badalona, Spain; Department of Medicine, Autonomous University of Barcelona, 08193, Barcelona, Spain
| | - Núria Alonso
- Department of Endocrinology and Nutrition, Germans Trias i Pujol Health Sciences Research Institute and Hospital, 08916, Badalona, Spain; Department of Medicine, Autonomous University of Barcelona, 08193, Barcelona, Spain; CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Instituto de Salud Carlos III (ISCIII), 28029, Madrid, Spain
| | - Roger Colobran
- Immunology Division, Vall d'Hebron Research Institute (VHIR), Vall d'Hebron University Hospital, 08035, Barcelona, Spain
| | - Alex Sánchez
- Statistics Department, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain; Statistics and Bioinformatics Unit, Vall d'Hebron Research Institute (VHIR), 08035, Barcelona, Spain
| | - Antoni Miñarro
- Statistics Department, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain
| | - Irma Pujol-Autonell
- Immunology Department, Germans Trias i Pujol Health Sciences Research Institute, 08916, Badalona, Autonomous University of Barcelona, Spain
| | - Jorge Carrascal
- Immunology Department, Germans Trias i Pujol Health Sciences Research Institute, 08916, Badalona, Autonomous University of Barcelona, Spain
| | - Silvia Rodríguez-Fernández
- Immunology Department, Germans Trias i Pujol Health Sciences Research Institute, 08916, Badalona, Autonomous University of Barcelona, Spain
| | - Rosa María Ampudia
- Immunology Department, Germans Trias i Pujol Health Sciences Research Institute, 08916, Badalona, Autonomous University of Barcelona, Spain
| | - Marta Vives-Pi
- Immunology Department, Germans Trias i Pujol Health Sciences Research Institute, 08916, Badalona, Autonomous University of Barcelona, Spain; CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Instituto de Salud Carlos III (ISCIII), 28029, Madrid, Spain
| | - Manel Puig-Domingo
- Department of Endocrinology and Nutrition, Germans Trias i Pujol Health Sciences Research Institute and Hospital, 08916, Badalona, Spain; Department of Medicine, Autonomous University of Barcelona, 08193, Barcelona, Spain; CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Instituto de Salud Carlos III (ISCIII), 28029, Madrid, Spain; CIBER of Rare Diseases (CIBERER), Instituto de Salud Carlos III (ISCIII), 28029, Madrid, Spain.
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14
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Novoselova EG, Glushkova OV, Lunin SM, Khrenov MO, Novoselova TV, Parfenyuk SB, Fesenko EE. Signaling, stress response and apoptosis in pre-diabetes and diabetes: restoring immune balance in mice with alloxan-induced type 1 diabetes mellitus. Int Immunopharmacol 2015; 31:24-31. [PMID: 26690976 DOI: 10.1016/j.intimp.2015.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/17/2015] [Accepted: 11/05/2015] [Indexed: 12/16/2022]
Abstract
The aim of this study was to compare immune imbalances in "pre-diabetic" and diabetic mice and to evaluate the efficacy of several agents in improving the immunity of mice with type 1 diabetes. Pre-diabetic and diabetic models generated by a single or double alloxan injection were monitored for plasma glucose and pancreas immunohistochemistry. To study the immunity in pre-diabetic and diabetic Balb/C male mice; the levels of cytokines; synthesis of inducible heat shock proteins HSP72 and HSP90α; activity of the NF-κB, IFR3, SAPK/JNK, and TLR4 pathways; and apoptosis levels in thymuses were measured. Pre-diabetes resulted in a decrease in IL-4, IL-5 and IL-10 in plasma; in diabetic mice, plasma IFN-gamma, IL-6, TNF-alpha, and IL-10 were decreased. The NF-κB alternative pathway activity and TLR4 expression were significantly increased only in pre-diabetic mice, whereas SAPK/JNK activation was observed at both stages of diabetes. Other measured parameters also showed distinct altered patterns in the immunity of pre-diabetic and diabetic mice. Treatment with an inhibitor of NF-κB, thymulin, or a diet with an antioxidant improved or normalized the immune balance in diabetic mice and also notably decreased pancreatic cell damage in pre-diabetic mice.
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Affiliation(s)
| | | | - Sergey M Lunin
- Institute of Cell Biophysics, Pushchino, Moscow region, Russia.
| | - Maxim O Khrenov
- Institute of Cell Biophysics, Pushchino, Moscow region, Russia
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15
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Marré ML, James EA, Piganelli JD. β cell ER stress and the implications for immunogenicity in type 1 diabetes. Front Cell Dev Biol 2015; 3:67. [PMID: 26579520 PMCID: PMC4621612 DOI: 10.3389/fcell.2015.00067] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 10/08/2015] [Indexed: 12/11/2022] Open
Abstract
Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by hyperglycemia due to progressive immune-mediated destruction of insulin-producing pancreatic islet β cells. Although many elegant studies have identified β cell autoantigens that are targeted by the autoimmune response, the mechanisms by which these autoantigens are generated remain poorly understood. Normal β cell physiology includes a high demand for insulin production and secretion in response to dynamic glucose sensing. This secretory function predisposes β cells to significantly higher levels of endoplasmic reticulum (ER) stress compared to nonsecretory cells. In addition, many environmental triggers associated with T1D onset further augment this inherent ER stress in β cells. ER stress may increase abnormal post-translational modification (PTM) of endogenous β cell proteins. Indeed, in other autoimmune disorders such as celiac disease, systemic lupus erythematosus, multiple sclerosis, and rheumatoid arthritis, abnormally modified neo-antigens are presented by antigen presenting cells (APCs) in draining lymph nodes. In the context of genetic susceptibility to autoimmunity, presentation of neo-antigens activates auto-reactive T cells and pathology ensues. Therefore, the ER stress induced by normal β cell secretory physiology and environmental triggers may be sufficient to generate neo-antigens for the autoimmune response in T1D. This review summarizes what is currently known about ER stress and protein PTM in target organs of other autoimmune disease models, as well as the data supporting a role for ER stress-induced neo-antigen formation in β cells in T1D.
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Affiliation(s)
- Meghan L Marré
- Division of Pediatric Surgery, Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh Pittsburgh, PA, USA
| | - Eddie A James
- Benaroya Research Institute at Virginia Mason Seattle, WA, USA
| | - Jon D Piganelli
- Division of Pediatric Surgery, Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh Pittsburgh, PA, USA
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16
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Liu Y, Zhang H, Zhang P, Meng F, Chen Y, Wang Y, Yao Y, Qi B. Autoimmune regulator expression in thymomas with or without autoimmune disease. Immunol Lett 2014; 161:50-6. [PMID: 24768600 DOI: 10.1016/j.imlet.2014.04.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/10/2014] [Accepted: 04/11/2014] [Indexed: 11/21/2022]
Abstract
BACKGROUND The autoimmune regulator (AIRE) regulates autoimmunity and self-antigen expression, such as acetylcholine receptor (AchR), in the thymus. Regulatory T cells (Tregs) can down-regulate autoimmunity, but also promote tumor growth. The objective of this study was to examine the levels of AIRE, AchR, and Foxp3 expression in thymomas. METHODS The relative levels of AIRE, AchR, and Foxp3 mRNA transcripts and the frequency of AIRE+, AchR+, and Foxp3+ cells were determined by quantitative RT-PCR and immunohistochemistry in 79 thymoma tissue samples from 21 patients with simple thymoma (the Tm group), 39 patients with myasthenia gravis (the MG group) and 19 patients with myasthenia gravis and one other autoimmune disease (the AD group). The numbers of peripheral blood CD4+CD25+Foxp3+ Tregs were determined by flow cytometry analysis. RESULTS The relative levels of AIRE and AchR mRNA transcripts in the MG group were significantly lower than that in the Tm group (p=0.04, p=0.03), but higher than that in the AD group (p=0.03, p=0.04). The relative levels of Foxp3 mRNA transcripts in the Tm group were significantly higher than that in the MG and AD groups (p=0.03 for both). A similar pattern of the percentages of AIRE+, AchR+, and Foxp3+ cells in the thymoma tissues and the numbers of peripheral blood Tregs were detected in these patients. The levels of AIRE mRNA transcripts were correlated positively with that of the AchR and Foxp3 in this population. The levels of AIRE and AchR mRNA transcripts in the A/AB/B1 types of thymomas were significantly higher than that in the B2/B3/C types of thymomas in this population. CONCLUSION Significantly lower levels of AIRE, AchR, and Foxp3 expression are associated with the development of thymoma-related autoimmune diseases.
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Affiliation(s)
- Yimei Liu
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Hui Zhang
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Peng Zhang
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China.
| | - Fanjie Meng
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Yuan Chen
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Yuanguo Wang
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Yuanyuan Yao
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
| | - Bin Qi
- Department of Cardiothoracic Surgery General Hospital at Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin300052 PR China
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17
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Ozerkan D, Ozsoy N, Cebesoy S. Response of thymus lymphocytes to streptozotocin-induced diabetes and exogenous vitamin C administration in rats. Microscopy (Oxf) 2014; 63:409-17. [PMID: 25145646 DOI: 10.1093/jmicro/dfu029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Diabetes causes oxidative stress, which in turn generates excessive free radicals resulting in cellular damage. Vitamin C is an antioxidant that protects tissues and organs from oxidative stress. The thymus is one of the most important lymphoid organs, which regulates T-lymphocyte proliferation and maturation. The aim of this study is to investigate the protective effects of vitamin C on the thymus of streptozotocin (STZ)-induced diabetic rats. The mitotic activity and cell integrity of thymic lymphocytes were explored. Wistar Albino rats were divided into three groups: control (Group 1), STZ-diabetes (Group 2) and vitamin C-treated STZ-diabetics (Group 3). Rats received a single intraperitoneal injection of 45 mg/kg STZ to induce diabetes. Vitamin C (20 mg/kg) was administered intragastrically. Semithin and ultrathin sections were examined under a light or an electron microscope, respectively. Considerable numbers of mitotic lymphocytes were observed in the thymus of control rats. In the diabetic rats, however, numbers of mitotic lymphocytes decreased to ∼57% of controls, and cell division abnormalities were observed. Additionally, diabetic rats showed degeneration in the structure of the thymus including trabecular thickening, accumulation of lipid vacuoles, heterochromatic nuclei and loss of mitochondrial cristae. Degradation of medullar and cortical integrity was also detected. In the vitamin C-treated STZ-diabetic group, the structure of the thymus and mitotic activity of the lymphocytes were similar to the control group. These results suggest that vitamin C protects the thymus against injury caused by diabetes and restores thymocyte mitotic activity.
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Affiliation(s)
- Dilşad Ozerkan
- Department of Biology, Faculty of Arts and Sciences, Kastamonu University, 37100, Kastamonu, Turkey
| | - Nesrin Ozsoy
- Department of Biology, Faculty of Science, Ankara University, 06100, Tandogan/Ankara, Turkey
| | - Suna Cebesoy
- Department of Biology, Faculty of Science, Ankara University, 06100, Tandogan/Ankara, Turkey
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18
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Thymic epithelial cell development and its dysfunction in human diseases. BIOMED RESEARCH INTERNATIONAL 2014; 2014:206929. [PMID: 24672784 PMCID: PMC3929497 DOI: 10.1155/2014/206929] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 11/28/2013] [Indexed: 12/01/2022]
Abstract
Thymic epithelial cells (TECs) are the key components in thymic microenvironment for T cells development. TECs, composed of cortical and medullary TECs, are derived from a common bipotent progenitor and undergo a stepwise development controlled by multiple levels of signals to be functionally mature for supporting thymocyte development. Tumor necrosis factor receptor (TNFR) family members including the receptor activator for NFκB (RANK), CD40, and lymphotoxin β receptor (LTβR) cooperatively control the thymic medullary microenvironment and self-tolerance establishment. In addition, fibroblast growth factors (FGFs), Wnt, and Notch signals are essential for establishment of functional thymic microenvironment. Transcription factors Foxn1 and autoimmune regulator (Aire) are powerful modulators of TEC development, differentiation, and self-tolerance. Dysfunction in thymic microenvironment including defects of TEC and thymocyte development would cause physiological disorders such as tumor, infectious diseases, and autoimmune diseases. In the present review, we will summarize our current understanding on TEC development and the underlying molecular signals pathways and the involvement of thymus dysfunction in human diseases.
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19
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Collado JA, Guitart C, Ciudad MT, Alvarez I, Jaraquemada D. The Repertoires of Peptides Presented by MHC-II in the Thymus and in Peripheral Tissue: A Clue for Autoimmunity? Front Immunol 2013; 4:442. [PMID: 24381570 PMCID: PMC3865459 DOI: 10.3389/fimmu.2013.00442] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 11/26/2013] [Indexed: 11/13/2022] Open
Abstract
T-cell tolerance to self-antigens is established in the thymus through the recognition by developing thymocytes of self-peptide-MHC complexes and induced and maintained in the periphery. Efficient negative selection of auto-reactive T cells in the thymus is dependent on the in situ expression of both ubiquitous and tissue-restricted self-antigens and on the presentation of derived peptides. Weak or inadequate intrathymic expression of self-antigens increases the risk to generate an autoimmune-prone T-cell repertoire. Indeed, even small changes of self-antigen expression in the thymus affect negative selection and increase the predisposition to autoimmunity. Together with other mechanisms, tolerance is maintained in the peripheral lymphoid organs via the recognition by mature T cells of a similar set of self-peptides in homeostatic conditions. However, non-lymphoid peripheral tissue, where organ-specific autoimmunity takes place, often have differential functional processes that may lead to the generation of epitopes that are absent or non-presented in the thymus. These putative differences between peptides presented by MHC molecules in the thymus and in peripheral tissues might be a major key to the initiation and maintenance of autoimmune conditions.
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Affiliation(s)
- Javier A Collado
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - Carolina Guitart
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - M Teresa Ciudad
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - Iñaki Alvarez
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - Dolores Jaraquemada
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
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