Mesenchymal stem cells isolated from fibrotic human lung tissue inhibit collagen expression by lung fibroblasts

Abstract

Introduction: Mesenchymal stem cells have been identified in the human lung; however, their role in lung disease is not clear. In animal models of lung fibrosis, beneficial effects of exogenously administrated stem cells have been demonstrated. In this study we isolated and characterized mesenchymal stem cells from fibrotic human lung tissue and studied their properties in vitro. Methods: Mesenchymal stem cells were cultured from lung tissue obtained from patient with fibrotic lung diseases (n=10). The characterization of cells was performed by immunofluorescence stainings. The effect of mesenchymal stem cell-conditioned media on collagen mRNA expression by fibroblasts was studied by real time RT-PCR. Stem cell-conditioned medium was subjected to size-exclusion filtration and filtrates were used to determine their effect on collagen mRNA expression in fibroblasts. Results: Expression of CD44, CD90, CD105, Oct3/4, and NANOG characterized the cells as pluripotent cells of mesenchymal origin. Compared to control medium, mesenchymal stem cell-conditioned medium significantly inhibited the expression of collagen type I mRNA by fibroblasts by 40% (p Conclusions: Our data demonstrate that conditioned medium obtained from lung mesenchymal stem cells exhibits anti-fibrotic properties via the inhibition of collagen expression by fibroblasts, suggesting that lung resident mesenchymal stem cells have fibro-protective properties and might therefore be a novel therapeutic approach for patients with idiopathic pulmonary fibrosis.