title: Chronic IL9 and IL-13 exposure leads to an altered differentiation of ciliated cells in a well-differentiated paediatric bronchial epithelial cell model.
abstract: Asthma is a chronic inflammatory disease characterised by airways remodelling. In mouse models IL-9 and IL-13 have been implicated in airways remodelling including mucus hypersecretion and goblet cell hyperplasia. Their role, especially that of IL-9, has been much less studied in authentic human ex vivo models of the bronchial epithelium from normal and asthmatic children. We assessed the effects of IL-9, IL-13 and an IL-9/IL-13 combination, during differentiation of bronchial epithelial cells from normal (n = 6) and asthmatic (n = 8) children. Cultures were analysed for morphological markers and factors associated with altered differentiation (MUC5AC, SPDEF and MMP-7). IL-9, IL-9/IL-13 combination and IL-13 stimulated bronchial epithelial cells from normal children had fewer ciliated cells [14.8% (SD 8.9), p = 0.048, 12.4 (SD 6.1), p = 0.016 and 7.3% (SD 6.6), p = 0.031] respectively compared with unstimulated [(21.4% (SD 9.6)]. IL-9 stimulation had no effect on goblet cell number in either group whereas IL-9/IL-13 combination and IL-13 significantly increased goblet cell number [24.8% (SD 8.8), p = 0.02), 32.9% (SD 8.6), p = 0.007] compared with unstimulated normal bronchial cells [(18.6% (SD 6.2)]. All stimulations increased MUC5AC mRNA in bronchial epithelial cells from normal children and increased MUC5AC mucin secretion. MMP-7 localisation was dysregulated in normal bronchial epithelium stimulated with Th2 cytokines which resembled the unstimulated bronchial epithelium of asthmatic children. All stimulations resulted in a significant reduction in transepithelial electrical resistance values over time suggesting a role in altered tight junction formation. We conclude that IL-9 does not increase goblet cell numbers in bronchial epithelial cell cultures from normal or asthmatic children. IL-9 and IL-13 alone and in combination, reduce ciliated cell numbers and transepithelial electrical resistance during differentiation of normal epithelium, which clinically could inhibit mucociliary clearance and drive an altered repair mechanism. This suggests an alternative role for IL-9 in airways remodelling and reaffirms IL-9 as a potential therapeutic target.
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland.
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Parker
authors.forename: Surendran
authors.initials: S
authors.lastname: Thavagnanam
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Skibinski
authors.forename: Jeremy
authors.initials: J
authors.lastname: Lyons
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bell
authors.forename: Liam G
authors.initials: LG
authors.lastname: Heaney
authors.forename: Michael D
authors.initials: MD
authors.lastname: Shields
mesh_terms: D001249:Asthma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D001980:Bronchi / Q000166:cytology; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D002923:Cilia; D004357:Drug Synergism; D017097:Electric Impedance; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D020397:Goblet Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D018793:Interleukin-13 / Q000378:metabolism / Q000494:pharmacology*; D016906:Interleukin-9 / Q000378:metabolism / Q000494:pharmacology*; D020783:Matrix Metalloproteinase 7 / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D055271:Mucin 5AC / Q000235:genetics / Q000378:metabolism; D050783:Proto-Oncogene Proteins c-ets / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D018793:Interleukin-13; D016906:Interleukin-9; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D050783:Proto-Oncogene Proteins c-ets; C403974:SPDEF protein, human; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7