hepatocyte growth factor HGF; pulmonary fibrosis; regeneration; paracrine factors; induced pluripotent stem cells iPSC
Ebener S, Barnowski S, Wotzkow C, Marti TM, Lopez-Rodriguez E, Crestani B, Blank F, Schmid RA, Geiser T, Funke M (2017), Toll-like receptor 4 activation attenuates profibrotic response in control lung fibroblasts but not in fibroblasts from patients with IPF, in Am J Physiol Lung Cell Mol Physiol
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Lutz D, Gazdhar A, Lopez-Rodriguez E, Ruppert C, Mahavadi P, Günther P, Klepetko W, Bates JH, Smith B, Geiser T, Ochs M, Knudsen L (2015), Alveolar derecruitment and collapse induration as crucial mechanisms in lung injury and fibrosis, in Am J Respir Cell Mol Biol
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Gazdhar A, Grad I, Tamò L, Gugger M, Feki A, Geiser T (2014), The secretome of induced pluripotent stem cells reduces lung fibrosis in part by hepatocyte growth factor, in Stem Cell Res Ther 2014 Nov 10
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Gazdhar A, Lebrecht D, Roth M, Tamm M, Venhoff N, Foocharoen C, Geiser T, Walker UA (2014), Time-dependent and somatically acquired mitochondrial DNA mutagenesis and respiratory chain dysfunction in a scleroderma model of lung fibrosis, in Sci Rep
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Gazdhar A, Susuri N, Hostettler K, Gugger M, Knudsen L, Roth M, Ochs M, Geiser T (2013), HGF expressing stem cells in usual interstitial pneumonia originate from the bone marrow and are antifibrotic, in PLoS One
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Nita I, Hostettler K, Tamò L, Medová M, Zhong J, Zimmer Y, Roth M, Geiser T, Gazdhar A, Hepatocyte growth factor secreted by bone marrow stem cell reduces ER stress and improves repair in alveolar epithelial type II cells in vitro, in Scient Reports
Background: Recent evidence suggest that idiopathic pulmonary fibrosis (IPF) is a disease of inefficient alveolar repair after repeated microinjuries. Mesenchymal bone-marrow derived stem cells (BMSC) have promising regenerative properties, mainly by release of paracrine factors that support regeneration and repair. Hepatocyte growth factor (HGF) is one of the major soluble factors inducing lung repair regeneration, thereby reducing pulmonary fibrosis. The regenerative effect of induced pluripotent stem cells (iPSC) on lung injury and fibrosis is not known.Hypothesis: iPSC, HGF-modified iPSC or iPS-derived alveolar epithelial cells (iPS-AEC) and their paracrine soluble factors induce alveolar epithelial repair in vitro and improve lung injury and fibrosis in vivo. Specific Aims: We will study the potential of a cell-based, but cell-free strategy in lung repair and fibrosis by using paracrine secreted factors from iPSC and modified iPSC. We will generate and characterize iPS cells in vitro regarding their proliferative, secretory and differentiation capacities to AEC and will study the effect of iPSC, HGF-modified iPSC and iPSC-AEC and their paracrine soluble factors on lung epithelail repair in vitro and pulmonary fibrosis in vivo.Methods: iPS cells will be generated by transfection of the transcription factors SOX2, OCT4, KLF4, and c-MYC and further modified by transfection of HGF or differentiation to iPS-AEC using specific culture conditions. iPSC will be characterized by FACS analysis, immunhistology and electron microscopy. The regenerative properties of iPSC, modified iPSC and their conditioned medium containing paracrine factors will be studied using our in vitro co-culture alveolar epithelial wound repair model. The effect of iPSC and their paracrine factors on lung injury and repair in vivo will be studied using a bleomycin induced lung injury and fibrosis model in the rat. Immunohistochemistry and electron microscopy in combination with morphometric, biochemical and functional analysis of the lung will be performed. Finally, paracrine soluble factors released by iPSC and modified iPSC will be identified and analyzed by proteomics followed by specific in vitro and in vivo inhibition experiments.Expected values of the project: Although stem cells offer very promising possibilities in regenerative medicine, BMSC or embryonic stem cells are difficult to obtain and have biological and ethical limitations. iPSC offer the advantage of generating pluripotent stem cells from individual patients that can be multiplied in culture, modified and differentiated before giving them back to the patients as specific treatment. Alternatively, paracrine soluble factors released from iPSC may be as efficient as iPSC alone and therefore represent another promising therapeutic strategy. We hope to contribute to the understanding of the therapeutic potential of iPSC and their paracrine factors in lung regeneration and repair, hoping to develop a novel theurapeutic approach in patients with pulmonary fibrosis.