title: Altered response of fibroblasts from human tympanosclerotic membrane to interacting mast cells: implication for tissue remodeling.
abstract: Several lines of evidence suggest that a tympanosclerotic (TMS) lesion often develops secondary to acute and chronic otitis media. Histological findings indicate that fibroblasts and inflammatory cells, including mast cells, play a key role in the tympanosclerotic plaque formation. However, details on the functional characteristics of tympanosclerotic fibroblasts (Fs(TMS)) are scanty. Therefore the aim of our study was to examine the activity of human fibroblasts from tympanosclerotic lesions and to evaluate the influence of stimulated by crosslinking of IgE receptor mast cells (HMC-1(FcɛRI)) on fibroblast functional behavior. We observed that fibroblasts from normal tympanic membrane (Fs(TM)) released less TNF-α, TGF-β1 and IL-6 compared to Fs(TMS). Fs(TMS) but not Fs(TM) upon interaction with HMC-1(FcɛRI) released increased quantities of TNF-α and TGF-β1. Exposing the fibroblast to HMC-1(FcɛRI) cells resulted in an increased synthesis of proteins including collagen. We noted that the COL2A1 transcript level increased ∼5- and ∼12-fold in Fs(TM) and Fs(TMS) co-cultured with HMC-1(FcɛRI), respectively. Both Fs(TM) and Fs(TMS) upon maintenance in the primary culture released significant quantities of matrix metalloproteinase 9 (MMP-9). However, Fs(TMS) released ∼5-fold more MMP-9 activity compared to the Fs(TM) cultures. The mast cell-induced release of TNF-α, TGF-β1 and MMP-9 sustained for a longer time in Fs(TMS) cultures compared to Fs(TM). Concluding, our data strongly indicate that increased fibroblast sensitivity to mast cell stimulation greatly contributes to the excessive fibrosis and pathological remodeling of the tympanic membrane. We postulate that the persistency of the Fs(TMS) activated state could be an important factor in the pathogenesis of tympanosclerosis.
authors.affiliation: Department of Molecular Medicine, Poland. Electronic address: tkpaw@gumed.edu.pl.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Pawelczyk
authors.affiliation: Department of Molecular Medicine, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Sakowicz-Burkiewicz
authors.affiliation: Department of Molecular Medicine, Poland.
authors.forename: Martyna
authors.initials: M
authors.lastname: Wesserling
authors.affiliation: Department of Molecular Medicine, Poland.
authors.forename: Marzena
authors.initials: M
authors.lastname: Grden
authors.affiliation: Department of Otolaryngology, Medical University of Gdansk, 80-211 Gdansk, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Kuczkowski
mesh_terms: D002450:Cell Communication / Q000502:physiology*; D002908:Chronic Disease; D003094:Collagen / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008407:Mast Cells / Q000378:metabolism / Q000473:pathology*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D063371:Myringosclerosis / Q000378:metabolism / Q000473:pathology*; D010033:Otitis Media / Q000378:metabolism / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D014409:Tumor Necrosis Factor-alpha; D003094:Collagen; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9
keywords: Collagens; Fibroblast; Mast cells; Matrix metalloproteinase-9; Tympanosclerosis