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Skibba ME, Brasier AR. NF-κB/RelA signaling in secretoglobin progenitors mediates plasticity and MMP-induced barrier disruption in house dust mite-induced allergic asthma. Am J Physiol Lung Cell Mol Physiol 2024; 327:L86-L101. [PMID: 38713619 PMCID: PMC11380976 DOI: 10.1152/ajplung.00066.2024] [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: 02/20/2024] [Revised: 04/23/2024] [Accepted: 04/23/2024] [Indexed: 05/09/2024] Open
Abstract
The mechanisms how aeroallergens induce sensitization are incompletely understood. The house dust mite (HDM) Dermatophagoides pteronyssius (Der p) is a ubiquitous aeroallergen that represents a major cause of allergic rhinitis and asthma. Herein, we tested whether HDM-induced aeroallergen exposure sensitivity is caused by the innate-immune response in small airway epithelial cells. HDM exposure is a rapid activator of NF-κB/RelA in the Secretoglobin (Scgb1a1+) lineage associated with upregulation of NF-κB/RelA-dependent markers of epithelial plasticity. To determine the effect of epithelial NF-κB signaling, NF-κB was depleted in a tamoxifen (TMX)-inducible Scgb1a1-CreERTM mouse within a CL57B/L6 background. Corn oil or TMX-treated/RelA-depleted [RelA knockdown (KD)] mice were repetitively exposed to airway HDM challenges to induce airway hyperresponsiveness (AHR). Strikingly, we observed that HDM induces hallmarks of epithelial plasticity through upregulation of the mesenchymal core factors SNAI1 and ZEB1 and production of metalloproteinase (MMP)9 that are RelA-dependent. Downstream, HDM-induced mucous metaplasia, Th2 polarization, allergen sensitivity, and airway hyperreactivity were all reduced in the RelA-depleted mice. Mechanistically, HDM-induced functional and structural barrier disruption was dependent on RelA signaling and associated with active MMP secretion into the bronchoalveolar lavage fluid. To establish the role of MMP2/9 in barrier disruption, we observe that a small-molecule MMP inhibitor (SB-3CT) blocked HDM-induced barrier disruption and activation of plasticity in naïve wild-type (WT) mice. Loss of functional barrier was associated with MMP disruption of zona occludens (ZO)-1 containing adherens junctions. Overall, this data indicates that host innate signaling in the Scgb1a1+ progenitors is directly linked to epithelial plasticity, MMP9 secretion, and enhanced barrier permeability that allows allergen penetration, sensitization producing allergic asthma (AA) in vivo. We propose that maintenance of epithelial integrity may reduce allergic sensitization and AA.NEW & NOTEWORTHY Allergic asthma from house dust mite (HDM) allergy causes substantial morbidity. This study examines the dynamic changes in small airway epithelial cells in a mouse model of HDM exposure. Our findings indicate that NF-κB/RelA signaling mediates matrix metalloproteinase production, disrupting the epithelial barrier resulting in allergic sensitization. Our findings bring new insight into mechanisms for epithelial cell-state change in the allergen response, creating a potential therapeutic pathway for maintaining barrier function in asthma.
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Affiliation(s)
- Melissa E Skibba
- School of Medicine and Public Health, University of Wisconsin Madison, Madison, Wisconsin, United States
| | - Allan R Brasier
- School of Medicine and Public Health, University of Wisconsin Madison, Madison, Wisconsin, United States
- Institute for Clinical and Translational Research, Madison, Wisconsin, United States
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2
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Xu X, Qiao D, Brasier AR. Cooperative interaction of interferon regulatory factor -1 and bromodomain-containing protein 4 on RNA polymerase activation for intrinsic innate immunity. Front Immunol 2024; 15:1366235. [PMID: 38601157 PMCID: PMC11004252 DOI: 10.3389/fimmu.2024.1366235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 03/14/2024] [Indexed: 04/12/2024] Open
Abstract
Introduction The human orthopneumovirus, Respiratory Syncytial Virus (RSV), is the causative agent of severe lower respiratory tract infections (LRTI) and exacerbations of chronic lung diseases. In immune competent hosts, RSV productively infects highly differentiated epithelial cells, where it elicits robust anti-viral, cytokine and remodeling programs. By contrast, basal cells are relatively resistant to RSV infection, in part, because of constitutive expression of an intrinsic innate immune response (IIR) consisting of a subgroup of interferon (IFN) responsive genes. The mechanisms controlling the intrinsic IIR are not known. Methods Here, we use human small airway epithelial cell hSAECs as a multipotent airway stem cell model to examine regulatory control of an intrinsic IIR pathway. Results We find hSAECs express patterns of intrinsic IIRs, highly conserved with pluri- and multi-potent stem cells. We demonstrate a core intrinsic IIR network consisting of Bone Marrow Stromal Cell Antigen 2 (Bst2), Interferon Induced Transmembrane Protein 1 (IFITM1) and Toll-like receptor (TLR3) expression are directly under IRF1 control. Moreover, expression of this intrinsic core is rate-limited by ambient IRF1• phospho-Ser 2 CTD RNA Polymerase II (pSer2 Pol II) complexes binding to their proximal promoters. In response to RSV infection, the abundance of IRF1 and pSer2 Pol II binding is dramatically increased, with IRF1 complexing to the BRD4 chromatin remodeling complex (CRC). Using chromatin immunoprecipitation in IRF1 KD cells, we find that the binding of BRD4 is IRF1 independent. Using a small molecule inhibitor of the BRD4 acetyl lysine binding bromodomain (BRD4i), we further find that BRD4 bromodomain interactions are required for stable BRD4 promoter binding to the intrinsic IIR core promoters, as well as for RSV-inducible pSer2 Pol II recruitment. Surprisingly, BRD4i does not disrupt IRF1-BRD4 interactions, but disrupts both RSV-induced BRD4 and IRF1 interactions with pSer2 Pol II. Conclusions We conclude that the IRF1 functions in two modes- in absence of infection, ambient IRF1 mediates constitutive expression of the intrinsic IIR, whereas in response to RSV infection, the BRD4 CRC independently activates pSer2 Pol II to mediates robust expression of the intrinsic IIR. These data provide insight into molecular control of anti-viral defenses of airway basal cells.
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Affiliation(s)
- Xiaofang Xu
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Dianhua Qiao
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Allan R. Brasier
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
- Institute for Clinical and Translational Research, University of Wisconsin-Madison, Madison, WI, United States
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Therapeutic potency of curcumin for allergic diseases: A focus on immunomodulatory actions. Biomed Pharmacother 2022; 154:113646. [PMID: 36063645 DOI: 10.1016/j.biopha.2022.113646] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/23/2022] Open
Abstract
In light of increasing research evidence on the molecular mechanisms of allergic diseases, the crucial roles of innate and acquired immunity in the disease's pathogenesis have been well highlighted. In this respect, much attention has been paid to the modulation of unregulated and unabated inflammatory responses aiming to suppress pathologic immune responses in treating allergic diseases. One of the most important natural compounds with a high potency of immune modulation is curcumin, an active polyphenol compound derived from turmeric, Curcuma longa L. Curcumin's immunomodulatory action mainly arises from its interactions with an extensive collection of immune cells such as mast cells, eosinophils, epithelial cells, basophils, neutrophils, and lymphocytes. Up to now, there has been no detailed investigation of curcumin's immunomodulatory actions in allergic diseases. So, the present review study aims to prepare an overview of the immunomodulatory effects of curcumin on the pathologic innate immune responses and dysregulated functions of T helper (TH) subtypes, including TH1, TH2, TH17, and regulator T cells (Tregs) by gathering evidence from several studies of In-vitro and In-vivo. As the second aim of the present review, we also discuss some novel strategies to overcome the limitation of curcumin in clinical use. Finally, this review also assesses the therapeutic potential of curcumin regarding its immunomodulatory actions in allergic diseases.
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Ferreira F, Mueller GA, Gilles S, Wills-Karp M. Editorial: Activation of Innate Immunity by Allergens and Allergenic Sources. FRONTIERS IN ALLERGY 2022; 2:800929. [PMID: 35386983 PMCID: PMC8974755 DOI: 10.3389/falgy.2021.800929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Fatima Ferreira
- Department of Biosciences, Paris-Lodron University of Salzburg, Salzburg, Austria
| | - Geoffrey A Mueller
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, United States
| | - Stefanie Gilles
- Department of Environmental Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany.,Institute of Environmental Medicine, Helmholtz Center Munich-Research for Environmental Health, Augsburg, Germany
| | - Marsha Wills-Karp
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
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Brasier AR, Qiao D, Zhao Y. The Hexosamine Biosynthetic Pathway Links Innate Inflammation With Epithelial-Mesenchymal Plasticity in Airway Remodeling. Front Pharmacol 2021; 12:808735. [PMID: 35002741 PMCID: PMC8727908 DOI: 10.3389/fphar.2021.808735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/07/2021] [Indexed: 01/15/2023] Open
Abstract
Disruption of the lower airway epithelial barrier plays a major role in the initiation and progression of chronic lung disease. Here, repetitive environmental insults produced by viral and allergens triggers metabolic adaptations, epithelial-mesenchymal plasticity (EMP) and airway remodeling. Epithelial plasticity disrupts epithelial barrier function, stimulates release of fibroblastic growth factors, and remodels the extracellular matrix (ECM). This review will focus on recent work demonstrating how the hexosamine biosynthetic pathway (HBP) links innate inflammation to airway remodeling. The HBP is a core metabolic pathway of the unfolded protein response (UPR) responsible for protein N-glycosylation, relief of proteotoxic stress and secretion of ECM modifiers. We will overview findings that the IκB kinase (IKK)-NFκB pathway directly activates expression of the SNAI-ZEB1 mesenchymal transcription factor module through regulation of the Bromodomain Containing Protein 4 (BRD4) chromatin modifier. BRD4 mediates transcriptional elongation of SNAI1-ZEB as well as enhancing chromatin accessibility and transcription of fibroblast growth factors, ECM and matrix metalloproteinases (MMPs). In addition, recent exciting findings that IKK cross-talks with the UPR by controlling phosphorylation and nuclear translocation of the autoregulatory XBP1s transcription factor are presented. HBP is required for N glycosylation and secretion of ECM components that play an important signaling role in airway remodeling. This interplay between innate inflammation, metabolic reprogramming and lower airway plasticity expands a population of subepithelial myofibroblasts by secreting fibroblastic growth factors, producing changes in ECM tensile strength, and fibroblast stimulation by MMP binding. Through these actions on myofibroblasts, EMP in lower airway cells produces expansion of the lamina reticularis and promotes airway remodeling. In this manner, metabolic reprogramming by the HBP mediates environmental insult-induced inflammation with remodeling in chronic airway diseases.
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Affiliation(s)
- Allan R. Brasier
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
- Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, United States
| | - Dianhua Qiao
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Yingxin Zhao
- Department of Internal Medicine, University of Texas Medical Branch Galveston, Galveston, TX, United States
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Xu X, Mann M, Qiao D, Li Y, Zhou J, Brasier AR. Bromodomain Containing Protein 4 (BRD4) Regulates Expression of its Interacting Coactivators in the Innate Response to Respiratory Syncytial Virus. Front Mol Biosci 2021; 8:728661. [PMID: 34765643 PMCID: PMC8577543 DOI: 10.3389/fmolb.2021.728661] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/24/2021] [Indexed: 12/12/2022] Open
Abstract
Bromodomain-containing protein 4 plays a central role in coordinating the complex epigenetic component of the innate immune response. Previous studies implicated BRD4 as a component of a chromatin-modifying complex that is dynamically recruited to a network of protective cytokines by binding activated transcription factors, polymerases, and histones to trigger their rapid expression via transcriptional elongation. Our previous study extended our understanding of the airway epithelial BRD4 interactome by identifying over 100 functionally important coactivators and transcription factors, whose association is induced by respiratory syncytial virus (RSV) infection. RSV is an etiological agent of recurrent respiratory tract infections associated with exacerbations of chronic obstructive pulmonary disease. Using a highly selective small-molecule BRD4 inhibitor (ZL0454) developed by us, we extend these findings to identify the gene regulatory network dependent on BRD4 bromodomain (BD) interactions. Human small airway epithelial cells were infected in the absence or presence of ZL0454, and gene expression profiling was performed. A highly reproducible dataset was obtained which indicated that BRD4 mediates both activation and repression of RSV-inducible gene regulatory networks controlling cytokine expression, interferon (IFN) production, and extracellular matrix remodeling. Index genes of functionally significant clusters were validated independently. We discover that BRD4 regulates the expression of its own gene during the innate immune response. Interestingly, BRD4 activates the expression of NFκB/RelA, a coactivator that binds to BRD4 in a BD-dependent manner. We extend this finding to show that BRD4 also regulates other components of its functional interactome, including the Mediator (Med) coactivator complex and the SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin (SMARC) subunits. To provide further insight into mechanisms for BRD4 in RSV expression, we mapped 7,845 RSV-inducible Tn5 transposase peaks onto the BRD4-dependent gene bodies. These were located in promoters and introns of cytostructural and extracellular matrix (ECM) formation genes. These data indicate that BRD4 mediates the dynamic response of airway epithelial cells to RNA infection by modulating the expression of its coactivators, controlling the expression of host defense mechanisms and remodeling genes through changes in promoter accessibility.
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Affiliation(s)
- Xiaofang Xu
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Morgan Mann
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Dianhua Qiao
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Yi Li
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jia Zhou
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, United States
| | - Allan R Brasier
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States.,Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, United States
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7
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Pointner L, Kraiem A, Thaler M, Richter F, Wenger M, Bethanis A, Klotz M, Traidl-Hoffmann C, Gilles S, Aglas L. Birch Pollen Induces Toll-Like Receptor 4-Dependent Dendritic Cell Activation Favoring T Cell Responses. FRONTIERS IN ALLERGY 2021; 2:680937. [PMID: 35386993 PMCID: PMC8974861 DOI: 10.3389/falgy.2021.680937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 07/15/2021] [Indexed: 12/12/2022] Open
Abstract
Seasonal exposure to birch pollen (BP) is a major cause of pollinosis. The specific role of Toll-like receptor 4 (TLR4) in BP-induced allergic inflammation and the identification of key factors in birch pollen extracts (BPE) initiating this process remain to be explored. This study aimed to examine (i) the importance of TLR4 for dendritic cell (DC) activation by BPE, (ii) the extent of the contribution of BPE-derived lipopolysaccharide (LPS) and other potential TLR4 adjuvant(s) in BPE, and (iii) the relevance of the TLR4-dependent activation of BPE-stimulated DCs in the initiation of an adaptive immune response. In vitro, activation of murine bone marrow-derived DCs (BMDCs) and human monocyte-derived DCs by BPE or the equivalent LPS (nLPS) was analyzed by flow cytometry. Polymyxin B (PMB), a TLR4 antagonist and TLR4-deficient BMDCs were used to investigate the TLR4 signaling in DC activation. The immunostimulatory activity of BPE was compared to protein-/lipid-depleted BPE-fractions. In co-cultures of BPE-pulsed BMDCs and Bet v 1-specific hybridoma T cells, the influence of the TLR4-dependent DC activation on T cell activation was analyzed. In vivo immunization of IL-4 reporter mice was conducted to study BPE-induced Th2 polarization upon PMB pre-treatment. Murine and human DC activation induced by either BPE or nLPS was inhibited by the TLR4 antagonist or by PMB, and abrogated in TLR4-deficient BMDCs compared to wild-type BMDCs. The lipid-free but not the protein-free fraction showed a reduced capacity to activate the TLR4 signaling and murine DCs. In human DCs, nLPS only partially reproduced the BPE-induced activation intensity. BPE-primed BMDCs efficiently stimulated T cell activation, which was repressed by the TLR4 antagonist or PMB, and the addition of nLPS to Bet v 1 did not reproduce the effect of BPE. In vivo, immunization with BPE induced a significant Th2 polarization, whereas administration of BPE pre-incubated with PMB showed a decreased tendency. These findings suggest that TLR4 is a major pathway by which BPE triggers DC activation that is involved in the initiation of adaptive immune responses. Further characterization of these BP-derived TLR4 adjuvants could provide new candidates for therapeutic strategies targeting specific mechanisms in BP-induced allergic inflammation.
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Affiliation(s)
- Lisa Pointner
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Amin Kraiem
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Michael Thaler
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Fabian Richter
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Mario Wenger
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | | | - Markus Klotz
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Claudia Traidl-Hoffmann
- Chair of Environmental Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
- Institute of Environmental Medicine, Helmholtz Zentrum München, Neuherberg, Germany
- Christine Kühne 96 Center for Allergy Research and Education (CK-CARE), Davos, Switzerland
| | - Stefanie Gilles
- Chair of Environmental Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
- Institute of Environmental Medicine, Helmholtz Zentrum München, Neuherberg, Germany
| | - Lorenz Aglas
- Department of Biosciences, University of Salzburg, Salzburg, Austria
- *Correspondence: Lorenz Aglas
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8
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Zhao Y, Zhang J, Sun H, Brasier AR. Crosstalk of the IκB Kinase with Spliced X-Box Binding Protein 1 Couples Inflammation with Glucose Metabolic Reprogramming in Epithelial-Mesenchymal Transition. J Proteome Res 2021; 20:3475-3488. [PMID: 34124911 DOI: 10.1021/acs.jproteome.1c00093] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Epithelial-mesenchymal transition (EMT) plays a critical role in airway injury, repair, and structural remodeling. IκB kinase (IKK)-NFκB signaling regulates late EMT-associated gene expression. However, IKK-mediated mesenchymal transition occurs earlier than NFκB/RelA subunit-dependent EMT gene expression, leading us to investigate the hypothesis that IKK plays an independent mechanism in transforming growth factor-β (TGFβ)-induced EMT. Time-resolved dissection of early proteome and phosphoproteome changes in response to TGFβ and a specific IKK inhibitor, BMS-345541, revealed that IKK regulates cascades of 23 signaling pathways essential in EMT, including TGFβ signaling, p38 mitogen associate protein kinase (MAPK), Toll receptor signaling, and integrin pathways. We identified early IKK-dependent phosphorylation of core regulatory proteins in essential EMT signaling cassettes, including ATF2, JUN, NFKB1/p105, and others. Interestingly, we found that IKKβ directly complexes with and phosphorylates the spliced X-box-binding protein 1 (XBP1s). XBP1s is an arm of the unfolded protein response (UPR) that activates the hexosamine biosynthetic pathway (HBP), a pathway that mediates protein N-glycosylation and survival from ER stress-induced apoptosis in EMT. We found that inhibition of IKK activity abolishes the phosphorylation of XBP1-T48, blocks XBP1s nuclear translocation, and inhibits the activation of HBP. Our study elucidates a previously unrecognized IKKβ-XBP1s-HBP crosstalk pathway that couples inflammation and glucose metabolic reprogramming in ETM. Because XBP1-HBP controls N-glycosylation of the extracellular matrix (ECM) in EMT, this novel IKKβ-XBP1-HBP pathway may contain therapeutic targets whose inhibition could prevent ECM remodeling in lung fibrosis or other airway remodeling diseases.
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Affiliation(s)
- Yingxin Zhao
- Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas 77555-1060, United States.,Institute for Translational Sciences, UTMB, Galveston, Texas 77555-0342, United States.,Sealy Center for Molecular Medicine, UTMB, Galveston, Texas 77555-0129, United States
| | - Jing Zhang
- Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas 77555-1060, United States
| | - Hong Sun
- Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas 77555-1060, United States
| | - Allan R Brasier
- Institute for Clinical and Translational Research, University of Wisconsin-Madison School of Public Health, Madison, Wisconsin 53705, United States
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9
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Xu X, Qiao D, Dong C, Mann M, Garofalo RP, Keles S, Brasier AR. The SWI/SNF-Related, Matrix Associated, Actin-Dependent Regulator of Chromatin A4 Core Complex Represses Respiratory Syncytial Virus-Induced Syncytia Formation and Subepithelial Myofibroblast Transition. Front Immunol 2021; 12:633654. [PMID: 33732255 PMCID: PMC7957062 DOI: 10.3389/fimmu.2021.633654] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 01/18/2021] [Indexed: 12/15/2022] Open
Abstract
Epigenetics plays an important role in the priming the dynamic response of airway epithelial cells to infectious and environmental stressors. Here, we examine the epigenetic role of the SWI/SNF Related, Matrix Associated, Actin Dependent Regulator of Chromatin A4 (SMARCA4) in the epithelial response to RSV infection. Depletion of SMARCA4 destabilized the abundance of the SMARCE1/ARID1A SWI/SNF subunits, disrupting the innate response and triggering a hybrid epithelial/mesenchymal (E/M) state. Assaying SMARCA4 complex-regulated open chromatin domains by transposase cleavage -next generation sequencing (ATAC-Seq), we observed that the majority of cleavage sites in uninfected cells have reduced chromatin accessibility. Paradoxically, SMARCA4 complex-depleted cells showed enhanced RSV-inducible chromatin opening and gene expression in the EMT pathway genes, MMP9, SNAI1/2, VIM, and CDH2. Focusing on the key MMP9, we observed that SMARCA4 complex depletion reduced basal BRD4 and RNA Polymerase II binding, but enhanced BRD4/Pol II binding in response to RSV infection. In addition, we observed that MMP9 secretion in SMARCA4 complex deficient cells contributes to mesenchymal transition, cellular fusion (syncytia) and subepithelial myofibroblast transition. We conclude the SMARCA4 complex is a transcriptional repressor of epithelial plasticity, whose depletion triggers a hybrid E/M state that affects the dynamic response of the small airway epithelial cell in mucosal remodeling via paracrine MMP9 activity.
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Affiliation(s)
- Xiaofang Xu
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Dianhua Qiao
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Chenyang Dong
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, United States
| | - Morgan Mann
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Roberto P. Garofalo
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, United States
| | - Sunduz Keles
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, United States
- Department of Biostatistics & Medical Informatics, University of Wisconsin-Madison, Madison, WI, United States
| | - Allan R. Brasier
- Department of Internal Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
- Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, United States
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10
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Skibba M, Drelich A, Poellmann M, Hong S, Brasier AR. Nanoapproaches to Modifying Epigenetics of Epithelial Mesenchymal Transition for Treatment of Pulmonary Fibrosis. Front Pharmacol 2020; 11:607689. [PMID: 33384604 PMCID: PMC7770469 DOI: 10.3389/fphar.2020.607689] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/09/2020] [Indexed: 12/11/2022] Open
Abstract
Idiopathic Pulmonary Fibrosis (IPF) is a chronically progressive interstitial lung that affects over 3 M people worldwide and rising in incidence. With a median survival of 2-3 years, IPF is consequently associated with high morbidity, mortality, and healthcare burden. Although two antifibrotic therapies, pirfenidone and nintedanib, are approved for human use, these agents reduce the rate of decline of pulmonary function but are not curative and do not reverse established fibrosis. In this review, we discuss the prevailing epithelial injury hypothesis, wherein pathogenic airway epithelial cell-state changes known as Epithelial Mesenchymal Transition (EMT) promotes the expansion of myofibroblast populations. Myofibroblasts are principal components of extracellular matrix production that result in airspace loss and mortality. We review the epigenetic transition driving EMT, a process produced by changes in histone acetylation regulating mesenchymal gene expression programs. This mechanistic work has focused on the central role of bromodomain-containing protein 4 in mediating EMT and myofibroblast transition and initial preclinical work has provided evidence of efficacy. As nanomedicine presents a promising approach to enhancing the efficacy of such anti-IPF agents, we then focus on the state of nanomedicine formulations for inhalable delivery in the treatment of pulmonary diseases, including liposomes, polymeric nanoparticles (NPs), inorganic NPs, and exosomes. These nanoscale agents potentially provide unique properties to existing pulmonary therapeutics, including controlled release, reduced systemic toxicity, and combination delivery. NP-based approaches for pulmonary delivery thus offer substantial promise to modify epigenetic regulators of EMT and advance treatments for IPF.
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Affiliation(s)
- Melissa Skibba
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Adam Drelich
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, United States
| | - Michael Poellmann
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, United States
| | - Seungpyo Hong
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, United States
- Carbone Cancer Center, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
- Yonsei Frontier Lab, Department of Pharmacy, Yonsei University, Seoul, South Korea
| | - Allan R. Brasier
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
- Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, United States
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