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Nelson PT, Fardo DW, Katsumata Y. The MUC6/AP2A2 Locus and Its Relevance to Alzheimer's Disease: A Review. J Neuropathol Exp Neurol 2020; 79:568-584. [PMID: 32357373 PMCID: PMC7241941 DOI: 10.1093/jnen/nlaa024] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/10/2020] [Indexed: 12/11/2022] Open
Abstract
We recently reported evidence of Alzheimer's disease (AD)-linked genetic variation within the mucin 6 (MUC6) gene on chromosome 11p, nearby the adaptor-related protein complex 2 subunit alpha 2 (AP2A2) gene. This locus has interesting features related to human genomics and clinical research. MUC6 gene variants have been reported to potentially influence viral-including herpesvirus-immunity and the gut microbiome. Within the MUC6 gene is a unique variable number of tandem repeat (VNTR) region. We discovered an association between MUC6 VNTR repeat expansion and AD pathologic severity, particularly tau proteinopathy. Here, we review the relevant literature. The AD-linked VNTR polymorphism may also influence AP2A2 gene expression. AP2A2 encodes a polypeptide component of the adaptor protein complex, AP-2, which is involved in clathrin-coated vesicle function and was previously implicated in AD pathogenesis. To provide background information, we describe some key knowledge gaps in AD genetics research. The "missing/hidden heritability problem" of AD is highlighted. Extensive portions of the human genome, including the MUC6 VNTR, have not been thoroughly evaluated due to limitations of existing high-throughput sequencing technology. We present and discuss additional data, along with cautionary considerations, relevant to the hypothesis that MUC6 repeat expansion influences AD pathogenesis.
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Affiliation(s)
- Peter T Nelson
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky
- Department of Pathology, University of Kentucky, Lexington, Kentucky
| | - David W Fardo
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky
- Department of Biostatistics, University of Kentucky, Lexington, Kentucky
| | - Yuriko Katsumata
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky
- Department of Biostatistics, University of Kentucky, Lexington, Kentucky
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2
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Abstract
Dysregulation of gel-forming mucins is associated with many airway diseases. Better knowledge of the pathophysiological mechanisms linking mucins and respiratory diseases will advance the understanding of their pathogenesis and should provide opportunities to develop new therapeutic compounds for treatment. MUC5B and MUC5AC are the two main gel-forming mucins in the respiratory tract. The organization in domains and the expression profile of mouse Muc5b are very similar to those in humans, which makes the mouse a relevant model for studies of the translational activities of human mucins. To assess the in vivo biological functions of Muc5b, a mouse reporter tagged in frame with the green fluorescent protein marker has been engineered by homologous recombination. The proof of concept that this reporter model may be informative for translational studies was confirmed by the finding that interleukin-13 administration in living mice upregulated Muc5b production.
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3
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Yamashita MSDA, Melo EO. Mucin 2 (MUC2) promoter characterization: an overview. Cell Tissue Res 2018; 374:455-463. [PMID: 30218241 DOI: 10.1007/s00441-018-2916-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 08/13/2018] [Indexed: 12/24/2022]
Abstract
Transgenic livestock have been studied with a well-known interest in improving quantitative and qualitative traits. In order to direct heterologous gene expression, it is indispensable to identify and characterize a promoter suitable for directing the expression of the gene of interest (GOI) in a tissue-specific way. The gastrointestinal tract is a desirable target for gene expression in several mammalian models. Throughout the surface of the intestinal epithelium, there is an intricate polymer network, formed by gel-forming mucins (especially MUC2 and MUC5AC, of which MUC2 is the major one), which plays a protective role due to the formation of a physical, chemical and immunological barrier between the organism and the environment. The characterization of the gel-forming mucins is difficult because of their large size and repetitive DNA sequences and domains. The main mucin in the small and large intestine, mucin 2 (MUC2), is expressed specifically in goblet cells. MUC2 plays an important role in intestinal homeostasis and its disruption is associated with several diseases and carcinomas. This mucin is also an important marker for elucidating mechanisms that regulate differentiation of the secretory cell lineage. This review presents the state of the art of MUC2 promoter structure and functional characterization.
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Affiliation(s)
| | - Eduardo O Melo
- EMBRAPA Genetic Resources and Biotechnology, PqEB Av W5 Norte, Brasilia, DF, 70770-917, Brazil
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4
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Penney ME, Parfrey PS, Savas S, Yilmaz YE. Associations of single nucleotide polymorphisms with mucinous colorectal cancer: genome-wide common variant and gene-based rare variant analyses. Biomark Res 2018; 6:17. [PMID: 29942513 PMCID: PMC5998544 DOI: 10.1186/s40364-018-0133-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/07/2018] [Indexed: 02/07/2023] Open
Abstract
Background Colorectal cancer has significant impact on individuals and healthcare systems. Many genes have been identified to influence its pathogenesis. However, the genetic basis of mucinous tumor histology, an aggressive subtype of colorectal cancer, is currently not well-known. This study aimed to identify common and rare genetic variations that are associated with the mucinous tumor phenotype. Methods Genome-wide single nucleotide polymorphism (SNP) data was investigated in a colorectal cancer patient cohort (n = 505). Association analyses were performed for 729,373 common SNPs and 275,645 rare SNPs. Common SNP association analysis was performed using univariable and multivariable logistic regression under different genetic models. Rare-variant association analysis was performed using a multi-marker test. Results No associations reached the traditional genome-wide significance. However, promising genetic associations were identified. The identified common SNPs significantly improved the discriminatory accuracy of the model for mucinous tumor phenotype. Specifically, the area under the receiver operating characteristic curve increased from 0.703 (95% CI: 0.634–0.773) to 0.916 (95% CI: 0.873–0.960) when considering the most significant SNPs. Additionally, the rare variant analysis identified a number of genetic regions that potentially contain causal rare variants associated with the mucinous tumor phenotype. Conclusions This is the first study applying both common and rare variant analyses to identify genetic associations with mucinous tumor phenotype using a genome-wide genotype data. Our results suggested novel associations with mucinous tumors. Once confirmed, these results will not only help us understand the biological basis of mucinous histology, but may also help develop targeted treatment options for mucinous tumors. Electronic supplementary material The online version of this article (10.1186/s40364-018-0133-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michelle E Penney
- 1Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada
| | - Patrick S Parfrey
- 2Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada
| | - Sevtap Savas
- 1Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.,3Discipline of Oncology, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada
| | - Yildiz E Yilmaz
- 1Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.,2Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.,4Department of Mathematics and Statistics, Faculty of Science, Memorial University of Newfoundland, St. John's, Canada
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5
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Demouveaux B, Gouyer V, Gottrand F, Narita T, Desseyn JL. Gel-forming mucin interactome drives mucus viscoelasticity. Adv Colloid Interface Sci 2018; 252:69-82. [PMID: 29329667 DOI: 10.1016/j.cis.2017.12.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 12/31/2022]
Abstract
Mucus is a hydrogel that constitutes the first innate defense in all mammals. The main organic component of mucus, gel-forming mucins, forms a complex network through both reversible and irreversible interactions that drive mucus gel formation. Significant advances in the understanding of irreversible gel-forming mucins assembly have been made using recombinant protein approaches. However, little is known about the reversible interactions that may finely modulate mucus viscoelasticity, which can be characterized using rheology. This approach can be used to investigate both the nature of gel-forming mucins interactions and factors that influence hydrogel formation. This knowledge is directly relevant to the development of new drugs to modulate mucus viscoelasticity and to restore normal mucus functions in diseases such as in cystic fibrosis. The aim of the present review is to summarize the current knowledge about the relationship between the mucus protein matrix and its functions, with emphasis on mucus viscoelasticity.
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Affiliation(s)
| | - Valérie Gouyer
- Univ. Lille, Inserm, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
| | - Frédéric Gottrand
- Univ. Lille, Inserm, CHU Lille, LIRIC UMR 995, F-59000 Lille, France
| | - Tetsuharu Narita
- Laboratoire Sciences et Ingénierie de la Matière Molle, PSL Research University, UPMC Univ Paris 06, ESPCI Paris, CNRS, 10 rue Vauquelin, 75231 Paris Cedex 05, France; Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan
| | - Jean-Luc Desseyn
- Univ. Lille, Inserm, CHU Lille, LIRIC UMR 995, F-59000 Lille, France.
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6
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Fan X, Jiao H, Zhao J, Wang X, Lin H. Lipopolysaccharide impairs mucin secretion and stimulated mucosal immune stress response in respiratory tract of neonatal chicks. Comp Biochem Physiol C Toxicol Pharmacol 2018; 204:71-78. [PMID: 29203321 DOI: 10.1016/j.cbpc.2017.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/22/2017] [Accepted: 11/28/2017] [Indexed: 11/17/2022]
Abstract
The chicken immune system is immature at the time of hatching. The development of the respiratory immune system after hatching is vital to young chicks. The aim of this study was to investigate the effect of LPS on respiratory mucin and IgA production in chicks. In this study, we selected 7days old AA broilers of similar weigh randomly; LPS atomized at 1mg/kg body weigh dose in the confined space of 1 cubic meter. The chickens exposed for 2h. Then collect samples after 4h and 8h respectively. Compared to control, LPS inhibited mucus production in BALF, caused a rising trend of the concentration of IgA in serum and BALF, and increased the protein expression of IgA in lung tissue. And LPS treat induced a decreasing trend of the mRNA expression of IL-6 and TGF-β and significantly decreased the gene expression of TGF-α and EGFR after 4h. After 8h the LPS suppressed the TGF-β mRNA expression significantly. In addition, LPS treatment stimulated airway epithelial cilia sparse after 4h. Therefore, results proved: LPS can impair mucin expression and stimulated mucosal immune stress reaction of respiratory tract. This study suggested that LPS involved in respiratory tract mucosal immune response in chicks by regulating gene expression of cytokines and epithelial growth factors.
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Affiliation(s)
- Xiaoxiao Fan
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Hongchao Jiao
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong 271018, China.
| | - Jingpeng Zhao
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Xiaojuan Wang
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong 271018, China.
| | - Hai Lin
- Department of Animal Science, Shandong Agricultural University, Taian, Shandong 271018, China.
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7
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Mucins, Mucus, and Goblet Cells. Chest 2017; 154:169-176. [PMID: 29170036 DOI: 10.1016/j.chest.2017.11.008] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/19/2017] [Accepted: 11/06/2017] [Indexed: 12/12/2022] Open
Abstract
The respiratory epithelium is lined by mucus, a gel consisting of water, ions, proteins, and macromolecules. The major macromolecular components of mucus are the mucin glycoproteins, which are critical for local defense of the airway. There are three classes of mucins in the airways: those that are secreted but do not polymerize (MUC7), those that are secreted and polymerize to form gels (MUC5AC, MUC5B), and those that have transmembrane domains and are cell surface associated (MUC1, MUC4, MUC16, MUC20). The mucins are regulated at the transcriptional, posttranscriptional, and epigenetic levels, and posttranslational modifications play an important role in mucin binding and clearance of microbes and pollutants. The development of mice deficient in specific mucins, and the cystic fibrosis pig, has greatly advanced our understanding of the role of mucins as innate immune mediators and how mucins and mucus contribute to lung disease. These observations suggest new strategies to ameliorate mucus obstruction by targeting mucociliary clearance and mucin hyperconcentration. Furthermore, a polymorphism in the promoter of MUC5B is strongly associated with risk of developing pulmonary fibrosis, supporting a novel function for MUC5B to influence interstitial lung disease. Exciting new data support the concept not only that mucins and mucus are important for lung homeostasis and protection from environmental threats but also that goblet cells play an important role as regulators of innate immune function. These insights into the innate immune properties of mucins and goblet cells support a shift from the current paradigm of repressing increased mucin expression to targeting regulation of specific mucins and the abnormal airway milieu.
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8
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The properties of the mucus barrier, a unique gel--how can nanoparticles cross it? Ther Deliv 2016; 7:229-44. [PMID: 27010985 DOI: 10.4155/tde-2015-0002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The key criterion for a nanoparticle drug-delivery system is the ability to produce substantial bioavailability without damaging the physiological protective mechanisms. The main area for drug delivery is the aerodigestive tract. All epithelial surfaces have a membrane-bound layer and in the lung this layer is surmounted by a gel layer. In the gastrointestinal tract the membrane-bound mucin layer is covered by a mucus bilayer. The pore sizes of mucus gels are around 100 to 200 nm. Consequently, only nanoparticles in this size range could potentially penetrate without modification of these layers. To study nanoparticle permeation with results that pertain to in vivo conditions, native mucus mucin preparations must be used. Strategies to increase pores in mucus gels are discussed herein.
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9
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Lee SN, Choi IS, Kim HJ, Yang EJ, Min HJ, Yoon JH. Proprotein convertase inhibition promotes ciliated cell differentiation - a potential mechanism for the inhibition of Notch1 signalling by decanoyl-RVKR-chloromethylketone. J Tissue Eng Regen Med 2016; 11:2667-2680. [PMID: 27878968 PMCID: PMC6214225 DOI: 10.1002/term.2240] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 04/22/2016] [Accepted: 06/17/2016] [Indexed: 01/17/2023]
Abstract
Chronic repetitive rounds of injury and repair in the airway lead to airway remodelling, including ciliated cell loss and mucous cell hyperplasia. Airway remodelling is mediated by many growth and differentiation factors including Notch1, which are proteolytically processed by proprotein convertases (PCs). The present study evaluated a novel approach for controlling basal cell‐type determination based on the inhibition of PCs. It was found that decanoyl‐RVKR‐chloromethylketone (CMK), a PC inhibitor, promotes ciliated cell differentiation and has no effect on the ciliary beat frequency in air–liquid interface (ALI) cultures of human nasal epithelial cells (HNECs). Comparative microarray analysis revealed that CMK considerably increases ciliogenesis‐related gene expression. Use of cell‐permeable and cell‐impermeable PC inhibitors suggests that intracellular PCs regulate basal cell‐type determination in ALI culture. Furthermore, CMK effect on ciliated cell differentiation was reversed by a Notch inhibitor N‐[N‐(3,5‐difluorophenacetyl)‐l‐alanyl]‐S‐phenylglycine t‐butyl ester (DAPT). CMK inhibited the processing of Notch1, a key regulator of basal cell differentiation toward secretory cell lineages in the airway epithelium, and down‐regulated the expression of Notch1 target genes together with furin, a PC. Specific lentiviral shRNA‐mediated knockdown of furin resulted in reduced Notch1 processing and increased numbers of ciliated cells in HNECs. Moreover, CMK inhibited Notch1 processing and promoted regeneration and ciliogenesis of the mouse nasal respiratory epithelium after ZnSO4 injury. These observations suggest that PC inhibition promotes airway ciliated cell differentiation, possibly through suppression of furin‐mediated Notch1 processing. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd
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Affiliation(s)
- Sang-Nam Lee
- Research Centre for Human Natural Defence System, Yonsei University College of Medicine, Seoul, Korea
| | - In-Suk Choi
- Research Centre for Human Natural Defence System, Yonsei University College of Medicine, Seoul, Korea
| | - Hyun Jun Kim
- Department of Otorhinolaryngology, School of Medicine, Ajou University, Seoul, Korea
| | - Eun Jin Yang
- Clinical Research Division, Korea Institute of Oriental Medicine, Seoul, Korea
| | - Hyun Jin Min
- Department of Otorhinolaryngology-Head and Neck Surgery, Chung-Ang University College of Medicine, Seoul, Korea
| | - Joo-Heon Yoon
- Research Centre for Human Natural Defence System, Yonsei University College of Medicine, Seoul, Korea.,Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea.,The Airway Mucus Institute, Yonsei University College of Medicine, Seoul, Korea
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10
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Yang R, Kerschner JL, Gosalia N, Neems D, Gorsic LK, Safi A, Crawford GE, Kosak ST, Leir SH, Harris A. Differential contribution of cis-regulatory elements to higher order chromatin structure and expression of the CFTR locus. Nucleic Acids Res 2016; 44:3082-94. [PMID: 26673704 PMCID: PMC4838340 DOI: 10.1093/nar/gkv1358] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/21/2015] [Accepted: 11/24/2015] [Indexed: 12/18/2022] Open
Abstract
Higher order chromatin structure establishes domains that organize the genome and coordinate gene expression. However, the molecular mechanisms controlling transcription of individual loci within a topological domain (TAD) are not fully understood. The cystic fibrosis transmembrane conductance regulator (CFTR) gene provides a paradigm for investigating these mechanisms.CFTR occupies a TAD bordered by CTCF/cohesin binding sites within which are cell-type-selective cis-regulatory elements for the locus. We showed previously that intronic and extragenic enhancers, when occupied by specific transcription factors, are recruited to the CFTR promoter by a looping mechanism to drive gene expression. Here we use a combination of CRISPR/Cas9 editing of cis-regulatory elements and siRNA-mediated depletion of architectural proteins to determine the relative contribution of structural elements and enhancers to the higher order structure and expression of the CFTR locus. We found the boundaries of the CFTRTAD are conserved among diverse cell types and are dependent on CTCF and cohesin complex. Removal of an upstream CTCF-binding insulator alters the interaction profile, but has little effect on CFTR expression. Within the TAD, intronic enhancers recruit cell-type selective transcription factors and deletion of a pivotal enhancer element dramatically decreases CFTR expression, but has minor effect on its 3D structure.
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Affiliation(s)
- Rui Yang
- Human Molecular Genetics Program, Lurie Children's Research Center, Chicago, IL 60614, USA Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Jenny L Kerschner
- Human Molecular Genetics Program, Lurie Children's Research Center, Chicago, IL 60614, USA Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Nehal Gosalia
- Human Molecular Genetics Program, Lurie Children's Research Center, Chicago, IL 60614, USA Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Daniel Neems
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Lidija K Gorsic
- Human Molecular Genetics Program, Lurie Children's Research Center, Chicago, IL 60614, USA Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Alexias Safi
- Division of Medical Genetics, Department of Pediatrics and Center for Genomic and Computational Biology, Duke University Medical School, Durham, NC 27708, USA
| | - Gregory E Crawford
- Division of Medical Genetics, Department of Pediatrics and Center for Genomic and Computational Biology, Duke University Medical School, Durham, NC 27708, USA
| | - Steven T Kosak
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Shih-Hsing Leir
- Human Molecular Genetics Program, Lurie Children's Research Center, Chicago, IL 60614, USA Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Ann Harris
- Human Molecular Genetics Program, Lurie Children's Research Center, Chicago, IL 60614, USA Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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β-Casein(94-123)-derived peptides differently modulate production of mucins in intestinal goblet cells. J DAIRY RES 2014; 82:36-46. [PMID: 25335546 DOI: 10.1017/s0022029914000533] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We recently reported the identification of a peptide from yoghurts with promising potential for intestinal health: the sequence (94-123) of bovine β-casein. This peptide, composed of 30 amino acid residues, maintains intestinal homoeostasis through production of the secreted mucin MUC2 and of the transmembrane-associated mucin MUC4. Our study aimed to search for the minimal sequence responsible for the biological activity of β-CN(94-123) by using several strategies based on (i) known bioactive peptides encrypted in β-CN(94-123), (ii) in silico prediction of peptides reactivity and (iii) digestion of β-CN(94-123) by enzymes of intestinal brush border membranes. The revealed sequences were tested in vitro on human intestinal mucus-producing HT29-MTX cells. We demonstrated that β-CN(108-113) (an ACE-inhibitory peptide) and β-CN(114-119) (an opioid peptide named neocasomorphin-6) up-regulated MUC4 expression whereas levels of the secreted mucins MUC2 and MUC5AC remained unchanged. The digestion of β-CN(94-123) by intestinal enzymes showed that the peptides β-CN(94-108) and β-CN(117-123) were present throughout 1·5 to 3 h of digestion, respectively. These two peptides raised MUC5AC expression while β-CN(117-123) also induced a decrease in the level of MUC2 mRNA and protein. In addition, this inhibitory effect was reproduced in airway epithelial cells. In conclusion, β-CN(94-123) is a multifunctional molecule but only the sequence of 30 amino acids has a stimulating effect on the production of MUC2, a crucial factor of intestinal protection.
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12
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Genetic susceptibility for chronic bronchitis in chronic obstructive pulmonary disease. Respir Res 2014; 15:113. [PMID: 25241909 PMCID: PMC4190389 DOI: 10.1186/s12931-014-0113-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/02/2014] [Indexed: 12/23/2022] Open
Abstract
Background Chronic bronchitis (CB) is one of the classic phenotypes of COPD. The aims of our study were to investigate genetic variants associated with COPD subjects with CB relative to smokers with normal spirometry, and to assess for genetic differences between subjects with CB and without CB within the COPD population. Methods We analyzed data from current and former smokers from three cohorts: the COPDGene Study; GenKOLS (Bergen, Norway); and the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE). CB was defined as having a cough productive of phlegm on most days for at least 3 consecutive months per year for at least 2 consecutive years. CB COPD cases were defined as having both CB and at least moderate COPD based on spirometry. Our primary analysis used smokers with normal spirometry as controls; secondary analysis was performed using COPD subjects without CB as controls. Genotyping was performed on Illumina platforms; results were summarized using fixed-effect meta-analysis. Results For CB COPD relative to smoking controls, we identified a new genome-wide significant locus on chromosome 11p15.5 (rs34391416, OR = 1.93, P = 4.99 × 10-8) as well as significant associations of known COPD SNPs within FAM13A. In addition, a GWAS of CB relative to those without CB within COPD subjects showed suggestive evidence for association on 1q23.3 (rs114931935, OR = 1.88, P = 4.99 × 10-7). Conclusions We found genome-wide significant associations with CB COPD on 4q22.1 (FAM13A) and 11p15.5 (EFCAB4A, CHID1 and AP2A2), and a locus associated with CB within COPD subjects on 1q23.3 (RPL31P11 and ATF6). This study provides further evidence that genetic variants may contribute to phenotypic heterogeneity of COPD. Trial registration ClinicalTrials.gov NCT00608764, NCT00292552 Electronic supplementary material The online version of this article (doi:10.1186/s12931-014-0113-2) contains supplementary material, which is available to authorized users.
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13
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Gosalia N, Neems D, Kerschner JL, Kosak ST, Harris A. Architectural proteins CTCF and cohesin have distinct roles in modulating the higher order structure and expression of the CFTR locus. Nucleic Acids Res 2014; 42:9612-22. [PMID: 25081205 PMCID: PMC4150766 DOI: 10.1093/nar/gku648] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 07/02/2014] [Accepted: 07/03/2014] [Indexed: 01/02/2023] Open
Abstract
Higher order chromatin structures across the genome are maintained in part by the architectural proteins CCCTC binding factor (CTCF) and the cohesin complex, which co-localize at many sites across the genome. Here, we examine the role of these proteins in mediating chromatin structure at the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CFTR encompasses nearly 200 kb flanked by CTCF-binding enhancer-blocking insulator elements and is regulated by cell-type-specific intronic enhancers, which loop to the promoter in the active locus. SiRNA-mediated depletion of CTCF or the cohesin component, RAD21, showed that these two factors have distinct roles in regulating the higher order organization of CFTR. CTCF mediates the interactions between CTCF/cohesin binding sites, some of which have enhancer-blocking insulator activity. Cohesin shares this tethering role, but in addition stabilizes interactions between the promoter and cis-acting intronic elements including enhancers, which are also dependent on the forkhead box A1/A2 (FOXA1/A2) transcription factors (TFs). Disruption of the three-dimensional structure of the CFTR gene by depletion of CTCF or RAD21 increases gene expression, which is accompanied by alterations in histone modifications and TF occupancy across the locus, and causes internalization of the gene from the nuclear periphery.
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Affiliation(s)
- Nehal Gosalia
- Human Molecular Genetics Program, Lurie Children's Research Center, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Daniel Neems
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60614, USA
| | - Jenny L Kerschner
- Human Molecular Genetics Program, Lurie Children's Research Center, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Steven T Kosak
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60614, USA
| | - Ann Harris
- Human Molecular Genetics Program, Lurie Children's Research Center, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
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Li M, Tian Y, Wu SD, Li YN. LPS induces MUC5AC expression in human biliary epithelial cells. Shijie Huaren Xiaohua Zazhi 2013; 21:2181-2184. [DOI: 10.11569/wcjd.v21.i22.2181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To examine whether lipopolysaccharide (LPS) stimulates MUC5AC expression in human biliary epithelial cells.
METHODS: Human biliary epithelial cells were treated with LPS, and MUC5AC mRNA and protein expression was detected by real time-PCR, Western blot and immunohistochemistry 12 and 24 h after LPS treatment.
RESULTS: LPS stimulation significantly increased MUC5AC mRNA expression (3.67 ± 0.22 vs 1.00 ± 0.05, P < 0.05). MUC5AC protein expression was also increased after LPS treatment (0.26 vs 0.59, P < 0.05).
CONCLUSION: LPS can induce MUC5AC expression in human biliary epithelial cells.
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