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Tao W, Ye Z, Wei Y, Wang J, Yang W, Yu G, Xiong J, Jia S. Insm1 regulates mTEC development and immune tolerance. Cell Mol Immunol 2023; 20:1472-1486. [PMID: 37990032 PMCID: PMC10687002 DOI: 10.1038/s41423-023-01102-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 10/30/2023] [Indexed: 11/23/2023] Open
Abstract
The expression of self-antigens in medullary thymic epithelial cells (mTECs) is essential for the establishment of immune tolerance, but the regulatory network that controls the generation and maintenance of the multitude of cell populations expressing self-antigens is poorly understood. Here, we show that Insm1, a zinc finger protein with known functions in neuroendocrine and neuronal cells, is broadly coexpressed with an autoimmune regulator (Aire) in mTECs. Insm1 expression is undetectable in most mimetic cell populations derived from mTECs but persists in neuroendocrine mimetic cells. Mutation of Insm1 in mice downregulated Aire expression, dysregulated the gene expression program of mTECs, and altered mTEC subpopulations and the expression of tissue-restricted antigens. Consistent with these findings, loss of Insm1 resulted in autoimmune responses in multiple peripheral tissues. We found that Insm1 regulates gene expression in mTECs by binding to chromatin. Interestingly, the majority of the Insm1 binding sites are co-occupied by Aire and enriched in superenhancer regions. Together, our data demonstrate the important role of Insm1 in the regulation of the repertoire of self-antigens needed to establish immune tolerance.
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Affiliation(s)
- Weihua Tao
- The First Affiliated Hospital of Jinan University, Guangzhou, China
- The Guangdong-Hong Kong-Macao Joint University Laboratory of Metabolic and Molecular Medicine, Jinan University, Guangzhou, China
- The Institute of Clinical Medicine, Jinan University, Guangzhou, China
- Key Lab of Guangzhou Basic and Translational Research of Pan-Vascular Diseases, Guangzhou, China
| | - Zhihuan Ye
- The First Affiliated Hospital of Jinan University, Guangzhou, China
- The Guangdong-Hong Kong-Macao Joint University Laboratory of Metabolic and Molecular Medicine, Jinan University, Guangzhou, China
- The Institute of Clinical Medicine, Jinan University, Guangzhou, China
| | - Yiqiu Wei
- The First Affiliated Hospital of Jinan University, Guangzhou, China
- The Guangdong-Hong Kong-Macao Joint University Laboratory of Metabolic and Molecular Medicine, Jinan University, Guangzhou, China
- The Institute of Clinical Medicine, Jinan University, Guangzhou, China
| | - Jianxue Wang
- The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Weixin Yang
- The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Guoxing Yu
- The First Affiliated Hospital of Jinan University, Guangzhou, China
- The Guangdong-Hong Kong-Macao Joint University Laboratory of Metabolic and Molecular Medicine, Jinan University, Guangzhou, China
- The Institute of Clinical Medicine, Jinan University, Guangzhou, China
| | - Jieyi Xiong
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.
- VIB-KU Leuven Center for Cancer Biology, Leuven, Belgium.
| | - Shiqi Jia
- The First Affiliated Hospital of Jinan University, Guangzhou, China.
- The Guangdong-Hong Kong-Macao Joint University Laboratory of Metabolic and Molecular Medicine, Jinan University, Guangzhou, China.
- The Institute of Clinical Medicine, Jinan University, Guangzhou, China.
- Key Lab of Guangzhou Basic and Translational Research of Pan-Vascular Diseases, Guangzhou, China.
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Duarte MJ, Mascarenhas RS, Assis AF, Tanaka PP, Speck-Hernandez CA, Passos GA. Autoimmune regulator act in synergism with thymocyte adhesion in the control of lncRNAs in medullary thymic epithelial cells. Mol Immunol 2021; 140:127-135. [PMID: 34700158 DOI: 10.1016/j.molimm.2021.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 05/30/2021] [Accepted: 10/07/2021] [Indexed: 12/06/2022]
Abstract
The autoimmune regulator (Aire) gene in medullary thymic epithelial cells (mTECs) encodes the AIRE protein, which interacts with its partners within the nucleus. This "Aire complex" induces stalled RNA Pol II on chromatin to proceed with transcription elongation of a large set of messenger RNAs and microRNAs. Considering that RNA Pol II also transcribes long noncoding RNAs (lncRNAs), we hypothesized that Aire might be implicated in the upstream control of this RNA species. To test this, we employed a loss-of-function approach in which Aire knockout mTECs were compared to Aire wild-type mTECs for lncRNA transcriptional profiling both in vitro and in vivo model systems. RNA sequencing enables the differential expression profiling of lncRNAs when these cells adhere in vitro to thymocytes or do not adhere to them as a way to test the effect of cell adhesion. Sets of lncRNAs that are unique and that are shared in vitro and in vivo were identified. Among these, we found the Aire-dependent lncRNAs as for example, Platr28, Ifi30, Morrbid, Malat1, and Xist. This finding represents the first evidence that Aire mediates the transcription of lncRNAs in mTECs. Microarray hybridizations enabled us to observe that temporal thymocyte adhesion modulates the expression levels of such lncRNAs as Morrbid, Xist, and Fbxl12o after 36 h of adhesion. This finding shows the existence of a synergistic mechanism involving a link between thymocyte adhesion, Aire, and lncRNAs in mTECs that might be important for immune self-representation.
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Affiliation(s)
- Max Jordan Duarte
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Romário S Mascarenhas
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Amanda Freire Assis
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Pedro Paranhos Tanaka
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Cesar A Speck-Hernandez
- Program in Basic and Applied Immunology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Geraldo Aleixo Passos
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil; Program in Basic and Applied Immunology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil; Laboratory of Genetics and Molecular Biology, Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, USP, Ribeirão Preto, SP, Brazil; Center for Cell-Based Therapy in Dentistry, USP, Ribeirão Preto, SP, Brazil.
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3
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Oliveira EH, Assis AF, Speck-Hernandez CA, Duarte MJ, Passos GA. Aire Gene Influences the Length of the 3' UTR of mRNAs in Medullary Thymic Epithelial Cells. Front Immunol 2020; 11:1039. [PMID: 32547551 PMCID: PMC7270294 DOI: 10.3389/fimmu.2020.01039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Aire is a transcriptional controller in medullary thymic epithelial cells (mTECs) modulating a set of peripheral tissue antigens (PTAs) and non-PTA mRNAs as well as miRNAs. Even miRNAs exerting posttranscriptional control of mRNAs in mTECs, the composition of miRNA-mRNA networks may differ. Under reduction in Aire expression, networks exhibited greater miRNA diversity controlling mRNAs. Variations in the number of 3'UTR binding sites of Aire-dependent mRNAs may represent a crucial factor that influence the miRNA interaction. To test this hypothesis, we analyzed through bioinformatics the length of 3'UTRs of a large set of Aire-dependent mRNAs. The data were obtained from existing RNA-seq of mTECs of wild type or Aire-knockout (KO) mice. We used computational algorithms as FASTQC, STAR and HTSEQ for sequence alignment and counting reads, DESEQ2 for the differential expression, 3USS for the alternative 3'UTRs and TAPAS for the alternative polyadenylation sites. We identified 152 differentially expressed mRNAs between these samples comprising those that encode PTAs as well as transcription regulators. In Aire KO mTECs, most of these mRNAs featured an increase in the length of their 3'UTRs originating additional miRNA binding sites and new miRNA controllers. Results from the in silico analysis were statistically significant and the predicted miRNA-mRNA interactions were thermodynamically stable. Even with no in vivo or in vitro experiments, they were adequate to show that lack of Aire in mTECs might favor the downregulation of PTA mRNAs and transcription regulators via miRNA control. This could unbalance the overall transcriptional activity in mTECs and thus the self-representation.
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Affiliation(s)
- Ernna H. Oliveira
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | | | - Cesar A. Speck-Hernandez
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Max Jordan Duarte
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Geraldo A. Passos
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
- Laboratory of Genetics and Molecular Biology, Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, USP, Ribeirão Preto, Brazil
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Guyon C, Jmari N, Padonou F, Li YC, Ucar O, Fujikado N, Coulpier F, Blanchet C, Root DE, Giraud M. Aire-dependent genes undergo Clp1-mediated 3'UTR shortening associated with higher transcript stability in the thymus. eLife 2020; 9:52985. [PMID: 32338592 PMCID: PMC7205469 DOI: 10.7554/elife.52985] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/24/2020] [Indexed: 12/23/2022] Open
Abstract
The ability of the immune system to avoid autoimmune disease relies on tolerization of thymocytes to self-antigens whose expression and presentation by thymic medullary epithelial cells (mTECs) is controlled predominantly by Aire at the transcriptional level and possibly regulated at other unrecognized levels. Aire-sensitive gene expression is influenced by several molecular factors, some of which belong to the 3'end processing complex, suggesting they might impact transcript stability and levels through an effect on 3'UTR shortening. We discovered that Aire-sensitive genes display a pronounced preference for short-3'UTR transcript isoforms in mTECs, a feature preceding Aire's expression and correlated with the preferential selection of proximal polyA sites by the 3'end processing complex. Through an RNAi screen and generation of a lentigenic mouse, we found that one factor, Clp1, promotes 3'UTR shortening associated with higher transcript stability and expression of Aire-sensitive genes, revealing a post-transcriptional level of control of Aire-activated expression in mTECs.
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Affiliation(s)
- Clotilde Guyon
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Nada Jmari
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Francine Padonou
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Université de Nantes, Inserm, Centre de Recherche en Transplantation et Immunologie, UMR 1064, ITUN, F-44000, Nantes, France
| | - Yen-Chin Li
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Olga Ucar
- Division of Developmental Immunology, German Cancer Research Center, Heidelberg, Germany
| | - Noriyuki Fujikado
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
| | - Fanny Coulpier
- Ecole Normale Supérieure, PSL Research University, CNRS, INSERM, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Plateforme Génomique, Paris, France
| | | | - David E Root
- The Broad Institute of MIT and Harvard, Cambridge, United States
| | - Matthieu Giraud
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Université de Nantes, Inserm, Centre de Recherche en Transplantation et Immunologie, UMR 1064, ITUN, F-44000, Nantes, France
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5
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Cotrim-Sousa L, Freire-Assis A, Pezzi N, Tanaka PP, Oliveira EH, Passos GA. Adhesion between medullary thymic epithelial cells and thymocytes is regulated by miR-181b-5p and miR-30b. Mol Immunol 2019; 114:600-611. [PMID: 31539668 DOI: 10.1016/j.molimm.2019.09.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 09/03/2019] [Accepted: 09/05/2019] [Indexed: 12/16/2022]
Abstract
In this work, we demonstrate that adhesion between medullary thymic epithelial cells (mTECs) and thymocytes is controlled by miRNAs. Adhesion between mTECs and developing thymocytes is essential for triggering negative selection (NS) of autoreactive thymocytes that occurs in the thymus. Immune recognition is mediated by the MHC / TCR receptor, whereas adhesion molecules hold cell-cell interaction stability. Indeed, these processes must be finely controlled, if it is not, it may lead to aggressive autoimmunity. Conversely, the precise molecular genetic control of mTEC-thymocyte adhesion is largely unclear. Here, we asked whether miRNAs would be controlling this process through the posttranscriptional regulation of mRNAs that encode adhesion molecules. For this, we used small interfering RNA to knockdown (KD) Dicer mRNA in vitro in a murine mTEC line. A functional assay with fresh murine thymocytes co-cultured with mTECs showed that single-positive (SP) CD4 and CD8 thymocyte adhesion was increased after Dicer KD and most adherent subtype was CD8 SP cells. Analysis of broad mTEC transcriptional expression showed that Dicer KD led to the modulation of 114 miRNAs and 422 mRNAs, including those encoding cell adhesion or extracellular matrix proteins, such as Lgals9, Lgals3pb, Tnc and Cd47. Analysis of miRNA-mRNA networks followed by miRNA mimic transfection showed that these mRNAs are under the control of miR-181b-5p and miR-30b*, which may ultimately control mTEC-thymocyte adhesion. The expression of CD80 surface marker in mTECs was increased after Dicer KD following thymocyte adhesion. This indicates the existence of new mechanisms in mTECs that involve the synergistic action of thymocyte adhesion and regulatory miRNAs.
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Affiliation(s)
- Larissa Cotrim-Sousa
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Amanda Freire-Assis
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil; State University of Minas Gerais, Passos, MG, Brazil
| | - Nicole Pezzi
- Graduate Program in Basic and Applied Immunology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Pedro Paranhos Tanaka
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Ernna Hérida Oliveira
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Geraldo Aleixo Passos
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil; Graduate Program in Basic and Applied Immunology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil; Laboratory of Genetics and Molecular Biology, Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, USP, Ribeirão Preto, SP, Brazil.
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Assis AF, Li J, Donate PB, Dernowsek JA, Manley NR, Passos GA. Predicted miRNA-mRNA-mediated posttranscriptional control associated with differences in cervical and thoracic thymus function. Mol Immunol 2018; 99:39-52. [DOI: 10.1016/j.molimm.2018.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 03/09/2018] [Accepted: 04/05/2018] [Indexed: 12/12/2022]
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Abstract
About two decades ago, cloning of the autoimmune regulator (AIRE) gene materialized one of the most important actors on the scene of self-tolerance. Thymic transcription of genes encoding tissue-specific antigens (ts-ags) is activated by AIRE protein and embodies the essence of thymic self-representation. Pathogenic AIRE variants cause the autoimmune polyglandular syndrome type 1, which is a rare and complex disease that is gaining attention in research on autoimmunity. The animal models of disease, although not identically reproducing the human picture, supply fundamental information on mechanisms and extent of AIRE action: thanks to its multidomain structure, AIRE localizes to chromatin enclosing the target genes, binds to histones, and offers an anchorage to multimolecular complexes involved in initiation and post-initiation events of gene transcription. In addition, AIRE enhances mRNA diversity by favoring alternative mRNA splicing. Once synthesized, ts-ags are presented to, and cause deletion of the self-reactive thymocyte clones. However, AIRE function is not restricted to the activation of gene transcription. AIRE would control presentation and transfer of self-antigens for thymic cellular interplay: such mechanism is aimed at increasing the likelihood of engagement of the thymocytes that carry the corresponding T-cell receptors. Another fundamental role of AIRE in promoting self-tolerance is related to the development of thymocyte anergy, as thymic self-representation shapes at the same time the repertoire of regulatory T cells. Finally, AIRE seems to replicate its action in the secondary lymphoid organs, albeit the cell lineage detaining such property has not been fully characterized. Delineation of AIRE functions adds interesting data to the knowledge of the mechanisms of self-tolerance and introduces exciting perspectives of therapeutic interventions against the related diseases.
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Affiliation(s)
- Roberto Perniola
- Department of Pediatrics, Neonatal Intensive Care, Vito Fazzi Regional Hospital, Lecce, Italy
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Passos GA, Speck‐Hernandez CA, Assis AF, Mendes‐da‐Cruz DA. Update on Aire and thymic negative selection. Immunology 2018; 153:10-20. [PMID: 28871661 PMCID: PMC5721245 DOI: 10.1111/imm.12831] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/24/2017] [Accepted: 08/31/2017] [Indexed: 12/17/2022] Open
Abstract
Twenty years ago, the autoimmune regulator (Aire) gene was associated with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy, and was cloned and sequenced. Its importance goes beyond its abstract link with human autoimmune disease. Aire identification opened new perspectives to better understand the molecular basis of central tolerance and self-non-self distinction, the main properties of the immune system. Since 1997, a growing number of immunologists and molecular geneticists have made important discoveries about the function of Aire, which is essentially a pleiotropic gene. Aire is one of the functional markers in medullary thymic epithelial cells (mTECs), controlling their differentiation and expression of peripheral tissue antigens (PTAs), mTEC-thymocyte adhesion and the expression of microRNAs, among other functions. With Aire, the immunological tolerance became even more apparent from the molecular genetics point of view. Currently, mTECs represent the most unusual cells because they express almost the entire functional genome but still maintain their identity. Due to the enormous diversity of PTAs, this uncommon gene expression pattern was termed promiscuous gene expression, the interpretation of which is essentially immunological - i.e. it is related to self-representation in the thymus. Therefore, this knowledge is strongly linked to the negative selection of autoreactive thymocytes. In this update, we focus on the most relevant results of Aire as a transcriptional and post-transcriptional controller of PTAs in mTECs, its mechanism of action, and its influence on the negative selection of autoreactive thymocytes as the bases of the induction of central tolerance and prevention of autoimmune diseases.
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Affiliation(s)
- Geraldo A. Passos
- Molecular Immunogenetics GroupDepartment of GeneticsRibeirão Preto Medical SchoolUniversity of São PauloRibeirão PretoSPBrazil
- Discipline of Genetics and Molecular BiologyDepartment of Morphology, Physiology and Basic PathologySchool of Dentistry of Ribeirão PretoUniversity of São PauloRibeirão PretoSPBrazil
| | - Cesar A. Speck‐Hernandez
- Graduate Programme in Basic and Applied ImmunologyRibeirão Preto Medical SchoolUniversity of São PauloRibeirão PretoSPBrazil
| | - Amanda F. Assis
- Molecular Immunogenetics GroupDepartment of GeneticsRibeirão Preto Medical SchoolUniversity of São PauloRibeirão PretoSPBrazil
| | - Daniella A. Mendes‐da‐Cruz
- Laboratory on Thymus ResearchOswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
- National Institute of Science and Technology on NeuroimmunomodulationRio de JaneiroRJBrazil
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MicroRNAs Regulate Thymic Epithelium in Age-Related Thymic Involution via Down- or Upregulation of Transcription Factors. J Immunol Res 2017; 2017:2528957. [PMID: 29226156 PMCID: PMC5684555 DOI: 10.1155/2017/2528957] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 08/09/2017] [Accepted: 08/20/2017] [Indexed: 12/14/2022] Open
Abstract
Age-related thymic involution is primarily induced by defects in nonhematopoietic thymic epithelial cells (TECs). It is characterized by dysfunction of multiple transcription factors (TFs), such as p63 and FoxN1, and also involves other TEC-associated regulators, such as Aire. These TFs and regulators are controlled by complicated regulatory networks, in which microRNAs (miRNAs) act as a key player. miRNAs can either directly target the 3'-UTRs (untranslated regions) of the TFs to suppress TF expression or target TF inhibitors to reduce or increase TF inhibitor expression and thereby indirectly enhance or inhibit TF expression. Here, we review the current understanding and recent studies about how miRNAs are involved in age-related thymic involution via regulation of TEC-autonomous TFs. We also discuss potential strategies for targeting miRNAs to rejuvenate age-related declined thymic function.
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