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Badaoui M, Chanson M. Intercellular Communication in Airway Epithelial Cell Regeneration: Potential Roles of Connexins and Pannexins. Int J Mol Sci 2023; 24:16160. [PMID: 38003349 PMCID: PMC10671439 DOI: 10.3390/ijms242216160] [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: 09/26/2023] [Revised: 10/19/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Connexins and pannexins are transmembrane proteins that can form direct (gap junctions) or indirect (connexons, pannexons) intercellular communication channels. By propagating ions, metabolites, sugars, nucleotides, miRNAs, and/or second messengers, they participate in a variety of physiological functions, such as tissue homeostasis and host defense. There is solid evidence supporting a role for intercellular signaling in various pulmonary inflammatory diseases where alteration of connexin/pannexin channel functional expression occurs, thus leading to abnormal intercellular communication pathways and contributing to pathophysiological aspects, such as innate immune defense and remodeling. The integrity of the airway epithelium, which is the first line of defense against invading microbes, is established and maintained by a repair mechanism that involves processes such as proliferation, migration, and differentiation. Here, we briefly summarize current knowledge on the contribution of connexins and pannexins to necessary processes of tissue repair and speculate on their possible involvement in the shaping of the airway epithelium integrity.
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Affiliation(s)
| | - Marc Chanson
- Department of Cell Physiology & Metabolism, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland;
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2
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Le Nabec A, Blotas C, Briset A, Collobert M, Férec C, Moisan S. 3D Chromatin Organization Involving MEIS1 Factor in the cis-Regulatory Landscape of GJB2. Int J Mol Sci 2022; 23:ijms23136964. [PMID: 35805969 PMCID: PMC9266880 DOI: 10.3390/ijms23136964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/17/2022] [Accepted: 06/21/2022] [Indexed: 02/04/2023] Open
Abstract
The human genome is covered by 8% of candidate cis-regulatory elements. The identification of distal acting regulatory elements and an understanding of their action are crucial to determining their key role in gene expression. Disruptions of such regulatory elements and/or chromatin conformation are likely to play a critical role in human genetic diseases. Non-syndromic hearing loss (i.e., DFNB1) is mostly due to GJB2 (Gap Junction Beta 2) variations and DFNB1 large deletions. Although several GJB2 cis-regulatory elements (CREs) have been described, GJB2 gene regulation remains not well understood. We investigated the endogenous effect of these CREs with CRISPR (clustered regularly interspaced short palindromic repeats) disruptions and observed GJB2 expression. To decipher the GJB2 regulatory landscape, we used the 4C-seq technique and defined new chromatin contacts inside the DFNB1 locus, which permit DNA loops and long-range regulation. Moreover, through ChIP-PCR, we determined the involvement of the MEIS1 transcription factor in GJB2 expression. Taken together, the results of our study enable us to describe the 3D DFNB1 regulatory landscape.
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Affiliation(s)
- Anaïs Le Nabec
- University Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (C.B.); (A.B.); (M.C.); (C.F.)
- Correspondence: or twitter@anaisnabec (A.L.N.); (S.M.); Tel.: +33-2-98-01-65-84 (A.L.N.); +33-2-98-01-65-67 (S.M.)
| | - Clara Blotas
- University Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (C.B.); (A.B.); (M.C.); (C.F.)
| | - Alinéor Briset
- University Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (C.B.); (A.B.); (M.C.); (C.F.)
| | - Mégane Collobert
- University Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (C.B.); (A.B.); (M.C.); (C.F.)
| | - Claude Férec
- University Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (C.B.); (A.B.); (M.C.); (C.F.)
| | - Stéphanie Moisan
- University Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France; (C.B.); (A.B.); (M.C.); (C.F.)
- Laboratoire de Génétique Moléculaire et d’Histocompatibilité, CHRU Brest, UMR 1078, F-29200 Brest, France
- Correspondence: or twitter@anaisnabec (A.L.N.); (S.M.); Tel.: +33-2-98-01-65-84 (A.L.N.); +33-2-98-01-65-67 (S.M.)
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Moisan S, Le Nabec A, Quillévéré A, Le Maréchal C, Férec C. Characterization of GJB2 cis-regulatory elements in the DFNB1 locus. Hum Genet 2019; 138:1275-1286. [PMID: 31586237 DOI: 10.1007/s00439-019-02068-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/29/2019] [Indexed: 11/28/2022]
Abstract
Although most disease-causing variants are within coding region of genes, it is now well established that cis-acting regulatory sequences, depending on 3D-chromatin organization, are required for temporal and spatial control of gene expression. Disruptions of such regulatory elements and/or chromatin conformation are likely to play a critical role in human genetic disease. Hence, recurrent monoallelic cases, who present the most common hereditary type of nonsyndromic hearing loss (i.e., DFNB1), carry only one identified pathogenic allele. This strongly suggests the presence of uncharacterized distal cis-acting elements in the missing allele. Here within, we study the spatial organization of a large DFNB1 locus encompassing the gap junction protein beta 2 (GJB2) gene, the most frequently mutated gene in this inherited hearing loss phenotype, with the chromosome conformation capture carbon copy technology (5C). By combining this approach with functional activity reporter assays and mapping of CCCTC-binding factor (CTCF) along the DFNB1 locus, we identify a novel set of cooperating GJB2 cis-acting elements and suggest a DFNB1 three-dimensional looping regulation model.
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Affiliation(s)
- Stéphanie Moisan
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, CHRU de Brest, Bretagne, Brest, France. .,Univ Brest, Inserm, EFS UMR 1078, GGB, 29200, Brest, France.
| | - Anaïs Le Nabec
- Univ Brest, Inserm, EFS UMR 1078, GGB, 29200, Brest, France
| | | | - Cédric Le Maréchal
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, CHRU de Brest, Bretagne, Brest, France.,Univ Brest, Inserm, EFS UMR 1078, GGB, 29200, Brest, France
| | - Claude Férec
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, CHRU de Brest, Bretagne, Brest, France. .,Univ Brest, Inserm, EFS UMR 1078, GGB, 29200, Brest, France.
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Chanson M, Watanabe M, O'Shaughnessy EM, Zoso A, Martin PE. Connexin Communication Compartments and Wound Repair in Epithelial Tissue. Int J Mol Sci 2018; 19:ijms19051354. [PMID: 29751558 PMCID: PMC5983803 DOI: 10.3390/ijms19051354] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 12/20/2022] Open
Abstract
Epithelial tissues line the lumen of tracts and ducts connecting to the external environment. They are critical in forming an interface between the internal and external environment and, following assault from environmental factors and pathogens, they must rapidly repair to maintain cellular homeostasis. These tissue networks, that range from a single cell layer, such as in airway epithelium, to highly stratified and differentiated epithelial surfaces, such as the epidermis, are held together by a junctional nexus of proteins including adherens, tight and gap junctions, often forming unique and localised communication compartments activated for localised tissue repair. This review focuses on the dynamic changes that occur in connexins, the constituent proteins of the intercellular gap junction channel, during wound-healing processes and in localised inflammation, with an emphasis on the lung and skin. Current developments in targeting connexins as corrective therapies to improve wound closure and resolve localised inflammation are also discussed. Finally, we consider the emergence of the zebrafish as a concerted whole-animal model to study, visualise and track the events of wound repair and regeneration in real-time living model systems.
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Affiliation(s)
- Marc Chanson
- Department of Pediatrics and Cell Physiology & Metabolism, Geneva University Hospitals and University of Geneva, 1211 Geneva, Switzerland.
| | - Masakatsu Watanabe
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan.
| | - Erin M O'Shaughnessy
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
| | - Alice Zoso
- Department of Pediatrics and Cell Physiology & Metabolism, Geneva University Hospitals and University of Geneva, 1211 Geneva, Switzerland.
| | - Patricia E Martin
- Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK.
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Kim R, Chang G, Hu R, Phillips A, Douglas R. Connexin gap junction channels and chronic rhinosinusitis. Int Forum Allergy Rhinol 2016; 6:611-7. [PMID: 26919292 DOI: 10.1002/alr.21717] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/04/2015] [Accepted: 12/15/2015] [Indexed: 12/24/2022]
Abstract
BACKGROUND Gap junction channels are formed by connexin (Cx) proteins. These channels facilitate communication between adjacent cells, and some have been implicated in acute and chronic inflammation. We investigated whether altered connexin expression could be associated with the inflammatory changes of the sinonasal mucosa that characterize chronic rhinosinusitis (CRS). Our aims were first to screen normal sinus mucosa to determine the expression profile of the connexin family of genes, and second to compare the level of expression of 3 key connexins (Cx26, Cx30, and Cx43) in CRS and normal sinus mucosa. These 3 connexins have been implicated in lower airway epithelial cell repair, as well as chronic and acute cutaneous wounds. METHODS Sinus mucosa biopsies were taken from 11 patients with CRS undergoing sinus surgery and from 7 controls with normal sinuses undergoing transnasal pituitary surgery. Gene expression study of the connexin family was performed using polymerase chain reaction (PCR). Subsequent targeted quantitative analyses were done using quantitative real-time PCR (qPCR) and fluorescent immunohistochemistry (IHC). RESULTS A total of 16 different connexin genes were expressed in the normal mucosa including Cx26, Cx30, and Cx43. The qPCR demonstrated increased abundance of Cx26 (p = 0.005), Cx30 (p = 0.07), and Cx43 (p = 0.04) in CRS compared to control mucosa. IHC confirmed significantly higher levels of Cx43 in CRS (p < 0.001). CONCLUSION The majority of the connexin family is expressed in normal sinus mucosa. Expression of 3 selected connexins was found elevated in CRS mucosa. Connexin gap junction modulation may offer a novel therapeutic target for CRS.
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Affiliation(s)
- Raymond Kim
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - George Chang
- Faculty of Medical and Health Science, and School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Rebecca Hu
- Faculty of Medical and Health Science, and School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Anthony Phillips
- Department of Surgery, The University of Auckland, Auckland, New Zealand.,Faculty of Medical and Health Science, and School of Biological Sciences, The University of Auckland, Auckland, New Zealand.,CoDa Therapeutics Inc, Auckland, New Zealand
| | - Richard Douglas
- Department of Surgery, The University of Auckland, Auckland, New Zealand
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Abstract
The different types of cells in the lung, from the conducting airway epithelium to the alveolar epithelium and the pulmonary vasculature, are interconnected by gap junctions. The specific profile of gap junction proteins, the connexins, expressed in these different cell types forms compartments of intercellular communication that can be further shaped by the release of extracellular nucleotides via pannexin1 channels. In this review, we focus on the physiology of connexins and pannexins and describe how this lung communication network modulates lung function and host defenses in conductive and respiratory airways.
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Affiliation(s)
- Davide Losa
- Geneva University Hospitals and University of Geneva, 1211 Geneva, Switzerland
- The ithree Institute, University of Technology Sydney, 2007 Ultimo, NSW Australia
| | - Marc Chanson
- Geneva University Hospitals and University of Geneva, 1211 Geneva, Switzerland
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Yang J, Qin G, Luo M, Chen J, Zhang Q, Li L, Pan L, Qin S. Reciprocal positive regulation between Cx26 and PI3K/Akt pathway confers acquired gefitinib resistance in NSCLC cells via GJIC-independent induction of EMT. Cell Death Dis 2015. [PMID: 26203858 PMCID: PMC4650742 DOI: 10.1038/cddis.2015.197] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Gefitinib efficiency in non-small-cell lung cancer (NSCLC) therapy is limited due to development of drug resistance. The molecular mechanisms of gefitinib resistance remain still unclear. In this study, we first found that connexin 26 (Cx26) is the predominant Cx isoform expressed in various NSCLC cell lines. Then, two gefitinib-resistant (GR) NSCLC cell lines, HCC827 GR and PC9 GR, from their parental cells were established. In these GR cells, the results showed that gefitinib resistance correlated with changes in cellular EMT phenotypes and upregulation of Cx26. Cx26 was detected to be accumulated in the cytoplasm and failed to establish functional gap-junctional intercellular communication (GJIC) either in GR cells or their parental cells. Ectopic expression of GJIC-deficient chimeric Cx26 was sufficient to induce EMT and gefitinib insensitivity in HCC827 and PC9 cells, while knockdown of Cx26 reversed EMT and gefitinib resistance in their GR cells both in vitro and in vivo. Furthermore, Cx26 overexpression could activate PI3K/Akt signaling in these cells. Cx26-mediated EMT and gefitinib resistance were significantly blocked by inhibition of PI3K/Akt pathway. Specifically, inhibition of the constitutive activation of PI3K/Akt pathway substantially suppressed Cx26 expression, and Cx26 was confirmed to functionally interplay with PI3K/Akt signaling to promote EMT and gefitinib resistance in NSCLC cells. In conclusion, the reciprocal positive regulation between Cx26 and PI3K/Akt signaling contributes to acquired gefitinib resistance in NSCLC cells by promoting EMT via a GJIC-independent manner.
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Affiliation(s)
- J Yang
- Department of Pharmacology, School of Pharmacy, Guangxi Medical University, 22 Shuangyong Road, Nanning 530021, Guangxi, China
| | - G Qin
- Department of Pharmacology, School of Pharmacy, Guangxi Medical University, 22 Shuangyong Road, Nanning 530021, Guangxi, China
| | - M Luo
- Department of Pharmacology, School of Pharmacy, Guangxi Medical University, 22 Shuangyong Road, Nanning 530021, Guangxi, China
| | - J Chen
- Department of Hepatobiliary Surgery, Affiliated Cancer Hospital, Guangxi Medical University, 71 Hedi Road, Nanning 530021, Guangxi, China
| | - Q Zhang
- Department of Pharmacology, School of Pharmacy, Guangxi Medical University, 22 Shuangyong Road, Nanning 530021, Guangxi, China
| | - L Li
- Division of Pulmonary, Department of Medicine, Allergy and Critical Care, Lung Biology Laboratory, Columbia University Medical Center, New York, NY 10032, USA
| | - L Pan
- Nephrology Division, The First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China
| | - S Qin
- Department of Respiratory Medicine, The First Affiliated Hospital, Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi, China
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Cx26 regulates proliferation of repairing basal airway epithelial cells. Int J Biochem Cell Biol 2014; 52:152-60. [DOI: 10.1016/j.biocel.2014.02.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 02/13/2014] [Accepted: 02/14/2014] [Indexed: 01/10/2023]
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Losa D, Chanson M, Crespin S. Connexins as therapeutic targets in lung disease. Expert Opin Ther Targets 2011; 15:989-1002. [PMID: 21585238 DOI: 10.1517/14728222.2011.584875] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The lung is a mechanically active system exposed to the external environment and is particularly sensitive to injury and inflammation. Studies have identified intercellular communication pathways that promote proper lung function in response to injury and disease. These pathways involve connexins (Cxs) and gap junctional intercellular communication (GJIC). AREAS COVERED IN THIS REVIEW The functional expression of Cxs in airway epithelium and vasculature, under normal and pathological conditions, is reviewed. Inhibition of GJIC and/or silencing of Cxs have been shown to modulate the course of disease development. Cx-based channels: i) coordinate ciliary beating and fluid transport to promote clearance of particulates, ii) regulate secretion of pulmonary surfactant, in response to deep inhalation by interconnecting type I and type II alveolar epithelial cells, and iii) are key mediators of pro- and anti-inflammatory signalling by the pulmonary endothelium, in order to modulate leukocyte recruitment from the circulation. EXPERT OPINION Cx-based channels play several central roles in promoting a regulated inflammatory response and facilitating lung repair, thus enabling the pulmonary epithelium and vasculature to behave as integrated systems. Several pathologies can disrupt the normal communication pathways required for proper lung function, including acute lung injury, asthma, cystic fibrosis, pulmonary fibrosis and cancer.
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Affiliation(s)
- Davide Losa
- Geneva University Hospitals and University of Geneva, Foundation for Medical Research , Laboratory of Clinical Investigation III, Switzerland
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Kaarteenaho R, Merikallio H, Lehtonen S, Harju T, Soini Y. Divergent expression of claudin -1, -3, -4, -5 and -7 in developing human lung. Respir Res 2010; 11:59. [PMID: 20478039 PMCID: PMC2886022 DOI: 10.1186/1465-9921-11-59] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 05/17/2010] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Claudins are the main components of tight junctions, structures which are associated with cell polarity and permeability. The aim of this study was to analyze the expression of claudins 1, 3, 4, 5, and 7 in developing human lung tissues from 12 to 40 weeks of gestation. METHODS 47 cases were analyzed by immunohistochemistry for claudins 1, 3, 4, 5 and 7. 23 cases were also investigated by quantitative RT-PCR for claudin-1, -3 and -4. RESULTS Claudin-1 was expressed in epithelium of bronchi and large bronchioles from week 12 onwards but it was not detected in epithelium of developing alveoli. Claudin-3, -4 and -7 were strongly expressed in bronchial epithelium from week 12 to week 40, and they were also expressed in alveoli from week 16 to week 40. Claudin-5 was expressed strongly during all periods in endothelial cells. It was expressed also in epithelium of bronchi from week 12 to week 40, and in alveoli during the canalicular period. RT-PCR analyses revealed detectable amounts of RNAs for claudins 1, 3 and 4 in all cases studied. CONCLUSION Claudin-1, -3, -4, -5, and -7 are expressed in developing human lung from week 12 to week 40 with distinct locations and in divergent quantities. The expression of claudin-1 was restricted to the bronchial epithelium, whereas claudin-3, -4 and -7 were positive also in alveolar epithelium as well as in the bronchial epithelium. All claudins studied are linked to the development of airways, whereas claudin-3, -4, -5 and -7, but not claudin-1, are involved in the development of acinus and the differentiation of alveolar epithelial cells.
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Affiliation(s)
- Riitta Kaarteenaho
- Institute of Diagnostics, Department of Pathology and Clinical Research Center, University of Oulu, Oulu, Finland.
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Mellow TE, Murphy PC, Carson JL, Noah TL, Zhang L, Pickles RJ. THE EFFECT OF RESPIRATORY SYNCTIAL VIRUS ON CHEMOKINE RELEASE BY DIFFERENTIATED AIRWAY EPITHELIUM. Exp Lung Res 2009; 30:43-57. [PMID: 14967603 DOI: 10.1080/01902140490252812] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Respiratory synctial virus (RSV) infection of undifferentiated airway epithelial cells has been shown to induce the production of chemokines. The purpose of this study was to investigate the vectorial release of interleukin (IL-8) and Released on Activation, Normal T-cell Expressed and Secreted (RANTES) by polarized, well-differentiated respiratory epithelial cells after RSV infection. Human bronchial epithelial cultures were differentiated under air-liquid interface conditions and infected with RSV by the apical or basolateral route. RSV infection was specific to the apical surface. Supernatants were collected at 6 and 48 hours after RSV inoculation, and IL-8 and RANTES were measured by enzyme-linked immunosorbent assay (ELISA). Both IL-8 and RANTES were significantly released by 48 hours following inoculation with RSV. The secretion of each chemokine was greatest after apical inoculation, and secretion was polarized to the basolateral supernatant. Immunohistochemical staining confirmed that RSV infection was specific to ciliated cells, and immunohistochemical staining for chemokines was localized to RSV-infected ciliated cells. The authors conclude that, in differentiated human airway epithelium in vitro, RSV-induced increases in IL-8 and RANTES release are predominantly in the basolateral direction. In epithelial layers, virus-containing cells are the predominant source of the increased chemokine release. The authors speculate that similar processes in vivo influence recruitment of leukocytes to sites of RSV infection.
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Affiliation(s)
- Thomas E Mellow
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7220, USA
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Kohn AZ, Hoxha Z, Balan KV, Martin RJ, Haxhiu MA, Wilson CG, Mayer CA, Kc P. Developmental changes in brainstem neurons regulating lower airway caliber. Pediatr Res 2009; 65:509-13. [PMID: 19190536 PMCID: PMC2761216 DOI: 10.1203/pdr.0b013e31819da270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Premature infants are at risk for lower airway obstruction; however, maturation of reflex pathways regulating lower airway patency is inadequately studied. We hypothesized that postnatal maturation causes developmental change in brainstem efferent airway-related vagal preganglionic neurons (AVPNs) within the rostral nucleus ambiguus (rNA) that project to the airways and in pulmonary afferent fibers that terminate in the nucleus tractus solitarius (NTS). Ferrets aged 7, 14, 21, and 42 d received intrapulmonary injection of cholera toxin (CT)-beta subunit, a transganglionic retrograde tracer. Five days later, their brainstem was processed for dual immunolabeling of CT-beta and the cholinergic marker, choline acetyl transferase. CT-beta-labeled AVPNs and CT-beta-labeled afferent fiber optical density (OD) were analyzed. There was a significantly higher CT-beta-labeled cell number within the rNA at the youngest compared with older ages. All efferent CT-beta-labeled cells expressed choline acetyl transferase. OD of CT-beta-labeled afferent fibers was also higher at 7 d compared with 14 d. We conclude that the number of efferent AVPNs and afferent fiber OD both diminish over the second postnatal week. We speculate that exposure to injurious agents in early postnatal life may inhibit natural remodeling and thereby enhance later vulnerability to airway hyperreactivity.
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Affiliation(s)
- Amitai Z Kohn
- Department of Pediatrics, Case Western Reserve University, Rainbow Babies and Children's Hospital, Cleveland, Ohio 44106, USA
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Johnson LN, Koval M. Cross-talk between pulmonary injury, oxidant stress, and gap junctional communication. Antioxid Redox Signal 2009; 11:355-67. [PMID: 18816185 PMCID: PMC2933150 DOI: 10.1089/ars.2008.2183] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Gap junction channels interconnect several different types of cells in the lung, ranging from the alveolar epithelium to the pulmonary vasculature, each of which expresses a unique subset of gap junction proteins (connexins). Major lung functions regulated by gap junctional communication include coordination of ciliary beat frequency and inflammation. Gap junctions help enable the alveolus to regulate surfactant secretion as an integrated system, in which type I cells act as mechanical sensors that transmit calcium transients to type II cells. Thus, disruption of epithelial gap junctional communication, particularly during acute lung injury, can interfere with these processes and increase the severity of injury. Consistent with this, connexin expression is altered during lung injury, and connexin-deficiency has a negative impact on the injury response and lung-growth control. It has recently been shown that alcohol abuse is a significant risk factor associated with acute respiratory distress syndrome. Oxidant stress and hormone-signaling cascades in the lung induced by prolonged alcohol ingestion are discussed, as well as the effects of these pathways on connexin expression and function.
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Affiliation(s)
- Latoya N Johnson
- Division of Pulmonary, Allergy and Critical Care Medicine, and Emory Alcohol and Lung Biology Center, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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Chen Y, Pacyna-Gengelbach M, Deutschmann N, Niesporek S, Petersen I. Homeobox gene HOP has a potential tumor suppressive activity in human lung cancer. Int J Cancer 2007; 121:1021-7. [PMID: 17417779 DOI: 10.1002/ijc.22753] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The homeobox containing gene HOP (Homeodomain Only Protein) was identified in the developing heart and lung where it functions downstream of Nkx2.5 and Nkx2.1 to modulate cardiac and lung gene expression. Previously, we found that HOP was downregulated in lung cancer. In this study, we constructed an expression vector containing the full-length cDNA of HOP and transfected it into a lung cancer cell line H2170. Stable transfection led to an increased expression of HOP confirmed by Northern blot analysis. HOP positive transfectants remarkably reduced the growth rate and the ability of anchorage-independent growth in soft agar, and moreover suppressed the tumor formation in nude mice compared to controls. Transient transfection of Nkx2.1 into H2170 resulted in the overexpression of HOP, and correspondingly, siRNA silencing of Nkx2.1 reduced the expression of HOP in lung cancer cells. Treatment with a differentiation modulating agent 5-bromodeoxyuridine (BrdU) led to restoration of HOP expression in a small cell lung cancer cell line H526. In 29 paired primary lung tumor samples, loss of heterozygosity (LOH) analysis was performed by using the 3 microsatellite markers D4S189, D4S231 and D4S392 around the region of chromosome 4q12 where HOP locates. LOH was only found in 4 out 23 cases (17.4%) indicating that allelic loss is a rare genetic event not responsible for the downregulation of HOP in lung cancer. Taken together, our data suggest that HOP is a potential tumor suppressor possibly involved in lung cancer differentiation, and functions downstream of Nkx2.1.
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Affiliation(s)
- Yuan Chen
- Institute of Pathology, University Hospital Charité, Schumannstr 20-21, D-10098 Berlin, Germany
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Wiszniewski L, Sanz J, Scerri I, Gasparotto E, Dudez T, Lacroix JS, Suter S, Gallati S, Chanson M. Functional expression of connexin30 and connexin31 in the polarized human airway epithelium. Differentiation 2007; 75:382-92. [PMID: 17428265 DOI: 10.1111/j.1432-0436.2007.00157.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gap junctions are documented in the human airway epithelium but the functional expression and molecular identity of their protein constituents (connexins, Cx) in the polarized epithelium is not known. To address this question, we documented the expression of a family of epithelial Cx (Cx26, Cx30, Cx30.3, Cx31, Cx31.1, Cx32, Cx37, Cx40, and Cx43) in primary human airway epithelial cells (AEC) grown on porous supports. Under submerged conditions, AEC formed a monolayer of airway cells whereas the air-liquid interface induced within 30-60 days AEC differentiation into a polarized epithelium for up to 6-9 months. Maturation of AEC was associated with the down-regulation of Cx26 and Cx43. The well-differentiated airway epithelium exhibited gap junctional communication between ciliated and between ciliated and basal cells. Interestingly, Cx30 was mostly present between ciliated cells whereas Cx31 was found between basal cells. These results are supportive of the establishment of signal-selective gap junctions with maturation of AEC, likely contributing to support airway epithelium function. These results lay the ground for studying the role of Cx-mediated cell-cell communication during repair following AEC injury and exploring Cx-targeted interventions to modulate the healing process.
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Affiliation(s)
- Ludovic Wiszniewski
- Laboratory of Clinical Investigation III, Department of Pediatrics, Geneva University Hospitals, Geneva, Switzerland
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16
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Chen Y, Pacyna-Gengelbach M, Deutschmann N, Ye F, Petersen I. 5-Bromodeoxyuridine induced differentiation of a human small cell lung cancer cell line is associated with alteration of gene expression. Biochem Biophys Res Commun 2007; 353:559-64. [PMID: 17196172 DOI: 10.1016/j.bbrc.2006.12.096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Accepted: 12/07/2006] [Indexed: 12/30/2022]
Abstract
Small cell lung cancer (SCLC) appears to arise from neuroendocrine cells with the potential to differentiate into a variety of lung epithelial cell lineages. In order to investigate molecular events underlying the cell type transition in SCLC, we treated a SCLC cell line H526 with a differentiation inducing agent 5-bromodeoxyuridine (BrdU). The treatment led to a dramatic conversion from suspension cells to adherent cells exhibiting an epithelioid phenotype, which remarkably reduced the ability of colony formation in soft agar and suppressed the tumor growth rate in nude mice. The phenotypic transition was consistent with upregulation of surfactant protein C (SFTPC), thyroid transcription factor 1 (TTF-1), Connexin 26 (Cx26), insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1), as well as homeobox genes LAGY, PITX1, and HOXB2. Our data suggest that BrdU induced cell differentiation could be linked to the development of a less aggressively phenotype in small cell lung cancer.
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Affiliation(s)
- Yuan Chen
- Institute of Pathology, Charité Medical School, University Hospital Charité, Humboldt-University, Schumannstr 20-21, D-10098 Berlin, Germany
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17
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Chen Y, Knösel T, Ye F, Pacyna-Gengelbach M, Deutschmann N, Petersen I. Decreased PITX1 homeobox gene expression in human lung cancer. Lung Cancer 2006; 55:287-94. [PMID: 17157953 DOI: 10.1016/j.lungcan.2006.11.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Revised: 09/29/2006] [Accepted: 10/26/2006] [Indexed: 11/27/2022]
Abstract
The PITX1 (pituitary homeobox 1) gene has essential roles in human development and has been considered a tumor suppressor in various cancers. However, in lung cancer the role of PITX1 remains to be elucidated. In this study, we analyzed the expression of PITX1 at both mRNA and protein levels in human lung cancer. The reduced PITX1 expression was found in cancer cell lines test compared to normal human bronchial epithelia cells (HEBC) and small airway epithelia cells (SAEC) by Northern blot analysis and RT-PCR as well as Western blot analysis. In primary lung tissues, PITX1 mRNA was found to be downregulated in the majority of tumors compared with normal lung tissues. An association between the lack of PITX1 mRNA expression and higher tumor grade was observed. A tissue microarray containing 135 primary lung carcinomas was analyzed by immunohistochemistry. Eighty-four cases (62%) exhibited no expression of PITX1 and the lower expression of PITX1 was significantly linked to higher tumor stages. Additionally, PITX1 was found to be upregulated in lung cancer cell lines H2228 and H526 after they were exposed to a differentiation modifying agent 5-bromodeoxyuridine (BrdU). Since homeobox genes are known to transcriptionally regulate key cellular processes and associated with differentiation and carcinogenesis, we suggest that PITX1 might be linked to lung cancer development and progression.
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Affiliation(s)
- Yuan Chen
- Institute of Pathology, University Hospital Charité, Schumannstr 20-21, D-10098 Berlin, Germany
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18
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Isakson BE, Olsen CE, Boitano S. Laminin-332 alters connexin profile, dye coupling and intercellular Ca2+ waves in ciliated tracheal epithelial cells. Respir Res 2006; 7:105. [PMID: 16884540 PMCID: PMC1559610 DOI: 10.1186/1465-9921-7-105] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Accepted: 08/02/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tracheal epithelial cells are anchored to a dynamic basement membrane that contains a variety of extracellular matrix proteins including collagens and laminins. During development, wound repair and disease of the airway epithelium, significant changes in extracellular matrix proteins may directly affect cell migration, differentiation and events mediated by intercellular communication. We hypothesized that alterations in cell matrix, specifically type I collagen and laminin alpha3beta3gamma2 (LM-332) proteins within the matrix, directly affect intercellular communication in ciliated rabbit tracheal epithelial cells (RTEC). METHODS Functional coupling of RTEC was monitored by microinjection of the negatively charged fluorescent dyes, Lucifer Yellow and Alexa 350, into ciliated RTEC grown on either a LM-332/collagen or collagen matrix. Coupling of physiologically significant molecules was evaluated by the mechanism and extent of propagated intercellular Ca2+ waves. Expression of connexin (Cx) mRNA and proteins were assayed by reverse transcriptase - polymerase chain reaction and immunocytochemistry, respectively. RESULTS When compared to RTEC grown on collagen alone, RTEC grown on LM-332/collagen displayed a significant increase in dye transfer. Although mechanical stimulation of RTEC grown on either LM-332/collagen or collagen alone resulted in intercellular Ca2+ waves, the mechanism of transfer was dependent on matrix: RTEC grown on LM-332/collagen propagated Ca2+waves via extracellular purinergic signaling whereas RTEC grown on collagen used gap junctions. Comparison of RTEC grown on collagen or LM-332/collagen matrices revealed a reorganization of Cx26, Cx43 and Cx46 proteins. CONCLUSION Alterations in airway basement membrane proteins such as LM-332 can induce connexin reorganizations and result in altered cellular communication mechanisms that could contribute to airway tissue function.
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Affiliation(s)
- Brant E Isakson
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, University of Virginia Charlottesville, Virginia 22908, USA
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Colin E Olsen
- Arizona Respiratory Center, Arizona Health Sciences Center, University of Arizona, Tucson, Arizona 85724, USA
| | - Scott Boitano
- Arizona Respiratory Center, Arizona Health Sciences Center, University of Arizona, Tucson, Arizona 85724, USA
- Department of Physiology, Arizona Health Sciences Center, University of Arizona, Tucson, Arizona 85724, USA
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19
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Boitano S, Safdar Z, Welsh DG, Bhattacharya J, Koval M. Cell-cell interactions in regulating lung function. Am J Physiol Lung Cell Mol Physiol 2004; 287:L455-9. [PMID: 15308493 DOI: 10.1152/ajplung.00172.2004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tight junction barrier formation and gap junctional communication are two functions directly attributable to cell-cell contact sites. Epithelial and endothelial tight junctions are critical elements of the permeability barrier required to maintain discrete compartments in the lung. On the other hand, gap junctions enable a tissue to act as a cohesive unit by permitting metabolic coupling and enabling the direct transmission of small cytosolic signaling molecules from one cell to another. These components do not act in isolation since other junctional elements, such as adherens junctions, help regulate barrier function and gap junctional communication. Some fundamental elements related to regulation of pulmonary barrier function and gap junctional communication were presented in a Featured Topic session at the 2004 Experimental Biology Conference in Washington, DC, and are reviewed in this summary.
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Affiliation(s)
- Scott Boitano
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, Arizona 85724, USA
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20
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Chen Y, Hühn D, Knösel T, Pacyna-Gengelbach M, Deutschmann N, Petersen I. Downregulation of connexin 26 in human lung cancer is related to promoter methylation. Int J Cancer 2004; 113:14-21. [PMID: 15386363 DOI: 10.1002/ijc.20498] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cell-Cell communication via gap junctions plays a key role in carcinogenesis and in growth control. One of the gap junction proteins, Connexin 26 (Cx26) was considered as tumor suppressor in various cancers. In our study, the expression of Cx26 was analyzed in human lung cancer. The reduced mRNA expression was observed in 17 lung cancer cell lines examined by Northern blot analysis and RT-PCR. In 138 primary carcinomas comprising all subtypes analyzed by immunohistochemistry, 85 cases (62%) exhibited no expression of Cx26, whereas in other 53 cases the Cx26 staining was positive (38%). Additionally, an association between Cx26 protein expression and higher grading of tumors was found in whole tumor samples (p =0.028) but no statistically significant correlations could be observed with tumor stage, tumor size and node status. In squamous cell carcinoma, tumors with higher stage and grading were linked to higher expression of Cx26 (p = 0.015 and 0.017, respectively). To explore the mechanism responsible for the downregulation of Cx26, we treated 2 lung cancer cell lines H2170 and H226 with the demethylation agent 5-aza-2'-deoxycytidine and found the reexpression of Cx26 mRNA. Methylation status of these 2 cell lines was further analyzed by PCR amplification of bisulfite modified DNA and sequencing. A heterogeneous methylation pattern turned out. Our results suggest the inactivation of Cx26 in lung cancer may be explained by promoter methylation.
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MESH Headings
- Actins
- Antimetabolites, Antineoplastic/pharmacology
- Azacitidine/analogs & derivatives
- Azacitidine/pharmacology
- Blotting, Northern
- Blotting, Southern
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/pathology
- Cell Line, Tumor
- Connexin 26
- Connexins/genetics
- DNA Methylation/drug effects
- DNA Modification Methylases/antagonists & inhibitors
- DNA, Neoplasm/metabolism
- Decitabine
- Down-Regulation/drug effects
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation, Enzymologic/drug effects
- Gene Expression Regulation, Neoplastic/drug effects
- Glyceraldehyde-3-Phosphate Dehydrogenases
- Humans
- Immunohistochemistry
- Lung Neoplasms/drug therapy
- Lung Neoplasms/genetics
- Lung Neoplasms/pathology
- Promoter Regions, Genetic/drug effects
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Analysis, DNA
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Affiliation(s)
- Yuan Chen
- Institute of Pathology, University Hospital Charité, Berlin, Germany
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21
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Isakson BE, Seedorf GJ, Lubman RL, Evans WH, Boitano S. Cell-cell communication in heterocellular cultures of alveolar epithelial cells. Am J Respir Cell Mol Biol 2003; 29:552-61. [PMID: 12748060 DOI: 10.1165/rcmb.2002-0281oc] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The mammalian alveolar epithelium is composed of alveolar type I (AT1) and alveolar type II (AT2) cells that together coordinate tissue function. We used a heterocellular culture model of AT1 and AT2 cells to determine pathways for intercellular signaling between these two phenotypes. Gap junction protein (connexin) profiles of AT1 and AT2 cells in heterocellular cultures were similar to those seen in rat lung alveolar sections. Dye coupling studies revealed functional gap junctions between and among each cell phenotype. Localized mechanical stimulation resulted in propagated changes of intracellular Ca2+ to AT1 or AT2 cells independent of the stimulated cell phenotype. Ca2+ communication that originated after AT1 cell stimulation was inhibited by gap junction blockers, but not by an inhibitor of extracellular nucleotide signaling (apyrase). Conversely, Ca2+ communication after stimulation of AT2 cells was not significantly reduced by gap junction inhibitors. However, apyrase significantly reduced Ca2+ communication from AT2 to AT1 cells, but not from AT2 to AT2 cells. In conclusion, AT1 and AT2 cells have unique connexin profiles that allow for functional coupling and distinct intercellular pathways for coordination of Ca2+ signaling.
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Affiliation(s)
- Brant E Isakson
- Department of Physiology, University of Arizona Health Sciences Center, Tucson, AZ 85724, USA
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22
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Koval M. Sharing signals: connecting lung epithelial cells with gap junction channels. Am J Physiol Lung Cell Mol Physiol 2002; 283:L875-93. [PMID: 12376339 DOI: 10.1152/ajplung.00078.2002] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Gap junction channels enable the direct flow of signaling molecules and metabolites between cells. Alveolar epithelial cells show great variability in the expression of gap junction proteins (connexins) as a function of cell phenotype and cell state. Differential connexin expression and control by alveolar epithelial cells have the potential to enable these cells to regulate the extent of intercellular coupling in response to cell stress and to regulate surfactant secretion. However, defining the precise signals transmitted through gap junction channels and the cross talk between gap junctions and other signaling pathways has proven difficult. Insights from what is known about roles for gap junctions in other systems in the context of the connexin expression pattern by lung cells can be used to predict potential roles for gap junctional communication between alveolar epithelial cells.
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Affiliation(s)
- Michael Koval
- Department of Physiology and Institute for Environmental Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
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23
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Isakson BE, Seedorf GJ, Lubman RL, Boitano S. Heterocellular cultures of pulmonary alveolar epithelial cells grown on laminin-5 supplemented matrix. In Vitro Cell Dev Biol Anim 2002; 38:443-9. [PMID: 12605538 DOI: 10.1290/1071-2690(2002)038<0443:hcopae>2.0.co;2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The pulmonary alveolar epithelium consists of alveolar type I (AT1) and alveolar type II (AT2) cells. Interactions between these two cell types are necessary for alveolar homeostasis and remodeling. These interactions have been difficult to study in vitro because current cell culture models of the alveolar epithelium do not provide a heterocellular population of AT1 and AT2 cells for an extended period of time in culture. In this study, a new method for obtaining heterocellular cultures of AT1- and AT2-like alveolar epithelial cells maintained for 7 d on a rat tail collagen-fibronectin matrix supplemented with laminin-5 is described. These cultures contain cells that appear by their morphology to be either AT1 cells (larger flattened cells without lamellar bodies) or AT2 cells (smaller cuboidal cells with lamellar bodies). AT1-like cells stain for the type I cell marker aquaporin-5, whereas AT2-like cells stain for the type II cell markers surfactant protein C or prosurfactant protein C. AT1/AT2 cell ratios, cell morphology, and cell phenotype-specific staining patterns seen in 7-d-old heterocellular cultures are similar to those seen in alveoli in situ. This culture system, in which a mixed population of phenotypically distinct alveolar epithelial cells are maintained, may facilitate in vitro studies that are more representative of AT1-AT2 cell interactions that occur in vivo.
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Affiliation(s)
- Brant E Isakson
- Department of Zoology and Physiology, University of Wyoming, 16th and Gibbon Streets, Laramie 82071-3166, USA
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24
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Isakson BE, Lubman RL, Seedorf GJ, Boitano S. Modulation of pulmonary alveolar type II cell phenotype and communication by extracellular matrix and KGF. Am J Physiol Cell Physiol 2001; 281:C1291-9. [PMID: 11546667 DOI: 10.1152/ajpcell.2001.281.4.c1291] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The alveolar epithelium consists of two cell types, alveolar type I (AT1) and alveolar type II (AT2) cells. We have recently shown that 7-day-old cultures of AT2 cells grown on a type I collagen/fibronectin matrix develop phenotypic characteristics of AT1 cells, display a distinct connexin profile, and coordinate mechanically induced intercellular Ca(2+) changes via gap junctions (25). In this study, we cultured AT2 cells for 7 days on matrix supplemented with laminin-5 and/or in the presence of keratinocyte growth factor. Under these conditions, cultured AT2 cells display AT2 type morphology, express the AT2-specific marker surfactant protein C, and do not express AT1-specific cell marker aquaporin 5, all consistent with maintenance of AT2 phenotype. These AT2-like cells also coordinate mechanically induced intercellular Ca(2+) signaling, but, unlike AT1-like cells, do so by using extracellular nucleotide triphosphate release. Additionally, cultured cells that retain AT2 cell-specific markers express connexin profiles different from cultured cells with AT1 characteristics. The parallel changes in intercellular Ca(2+) signaling with cell differentiation suggest that cell signaling mechanisms are an intrinsic component of lung alveolar cell phenotype. Because lung epithelial injury is accompanied by extracellular matrix and growth factor changes, followed by extensive cell division, differentiation, and migration of AT2 progenitor cells, we suggest that similar changes may be vital to the lung recovery and repair process in vivo.
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Affiliation(s)
- B E Isakson
- Department of Zoology and Physiology, University of Wyoming, Laramie, 82071-3166, USA
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25
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Affiliation(s)
- D E Rannels
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, 500 University Dr., Hershey, PA 17033, USA.
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26
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Crandall ED, Matthay MA. Alveolar epithelial transport. Basic science to clinical medicine. Am J Respir Crit Care Med 2001; 163:1021-9. [PMID: 11282783 DOI: 10.1164/ajrccm.163.4.2006116] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- E D Crandall
- Department of Medicine, University of Southern California, Los Angeles, USA
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27
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Guo Y, Martinez-Williams C, Yellowley CE, Donahue HJ, Rannels DE. Connexin expression by alveolar epithelial cells is regulated by extracellular matrix. Am J Physiol Lung Cell Mol Physiol 2001; 280:L191-202. [PMID: 11158997 DOI: 10.1152/ajplung.2001.280.2.l191] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Extracellular matrix (ECM) proteins promote attachment, spreading, and differentiation of cultured alveolar type II epithelial cells. The present studies address the hypothesis that the ECM also regulates expression and function of gap junction proteins, connexins, in this cell population. Expression of cellular fibronectin and connexin (Cx) 43 increase in parallel during early type II cell culture as Cx26 expression declines. Gap junction intercellular communication is established over the same interval. Cells plated on a preformed, type II cell-derived, fibronectin-rich ECM demonstrate accelerated formation of gap junction plaques and elevated gap junction intercellular communication. These effects are blocked by antibodies against fibronectin, which cause redistribution of Cx43 protein from the plasma membrane to the cytoplasm. Conversely, cells cultured on a laminin-rich ECM, Matrigel, express low levels of Cx43 but high levels of Cx26, reflecting both transcriptional and translational regulation. Cx26 and Cx43 thus demonstrate reciprocal regulation by ECM constituents.
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Affiliation(s)
- Y Guo
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
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28
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Hama T, Oyamada M, Dejima K, Takenaka H, Takamatsu T. Expression of Gap Junctional Protein Connexins in Human Nasal Epithelium, and Its Contribution to Intercellular Calcium Signalling. Acta Histochem Cytochem 2000. [DOI: 10.1267/ahc.33.23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Takemitsu Hama
- Department of Pathology and Cell Regulation,Kyoto Prefectural University of Medicine,Kawaramachi Hirokoji,Kamigyo-ku,Kyoto 602-0841
- Department of Otorhinolaryngology,Kyoto Prefectural University of Medicine,Kyoto 602-8566
| | - Masahito Oyamada
- Department of Pathology and Cell Regulation,Kyoto Prefectural University of Medicine,Kawaramachi Hirokoji,Kamigyo-ku,Kyoto 602-0841
| | - Kenji Dejima
- Department of Otorhinolaryngology,Kyoto Prefectural University of Medicine,Kyoto 602-8566
| | - Hiroshi Takenaka
- Department of Otorhinolaryngology,Osaka Medical Collage,Osaka 569-0801
| | - Tetsuro Takamatsu
- Department of Pathology and Cell Regulation,Kyoto Prefectural University of Medicine,Kawaramachi Hirokoji,Kamigyo-ku,Kyoto 602-0841
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