Modeling of spontaneous pulmonary fibrosis via cellular senescence in type 2 alveolar epithelial cells derived from human iPSCs [HFLF]
Telomere dysfunction in type II alveolar epithelial (AT2) cells causes pulmonary fibrosis in a subset of patients. TRF2 is a key component of the shelterin complex (SC) which prevents abnormally shortened and uncapped telomeres and genetic variants of SC were reported in some familial cases of IPF. We conceived that in vitro senescence model of AT2 cells derived from human induced pluripotent stem cells (iPSCs) would be beneficial for elucidating the mechanism of IPF progression. Then we generated an iPSC line using a doxycycline (dox) -inducible lentiviral vector encoding the dominant negative variant of TRF2 (TRF2DN). We next differentiated this iPSC line into AT2 (iAT2) cells and expressed TRF2DN protein in a dox-inducible manner. Alveolar organoids consisting of TRF2DN-expressing iAT2 cells and human fetal lung fibroblasts showed contraction of the organoid matrices Overall design: Alveolar organoids composed of tet-on TRF2DN iPSC line (T67)-derived alveolar epithelial cells and human fetal lung fibroblasts (HFLFs) were treated with or without doxycycline (DOX) for 8 days. For gene expression profile analysis, HFLFs were isolated from the organoids through magnetic activated cell sorting using anti-EpCAM antibody.