Fig. 5
From: Antifibrotic effect of lung-resident progenitor cells with high aldehyde dehydrogenase activity
CD45−/ALDHbr cell therapy ameliorates BLM-induced pulmonary fibrosis CD45−/ALDHbr cell therapy ameliorates BLM-induced pulmonary fibrosis. A Lung hydroxyproline content on day 14 in BLM-treated mice transferred with CD45−/ALDHdim (n = 7) and CD45−/ALDHbr (n = 4) cells on day 2. *P < 0.05. B HE-staining of lung tissue sections obtained from PBS-treated and BLM-treated mice transferred with CD45−/ALDHdim and CD45−/ALDHbr cells. C Real-time quantitative PCR analysis of the mRNA expression levels of TGF-β1 and IL-6 in lung tissues on day 7 obtained from BLM-treated mice transferred with CD45−/ALDHdim (n = 9–10) and CD45−/ALDHbr (n = 7–8) cells. Values are expressed relative to the expression of the endogenous control β-actin mRNA and normalized to the mean value of the CD45−/ALDHdim i.v. group set as 1. *P < 0.05. D Representative images of flow cytometry of lung CD45−/ALDHbr cells in BLM-treated mice transferred with PBS alone, CD45−/ALDHdim cells, and CD45−/ALDHbr cells on day 14. E Real-time quantitative PCR analysis of the mRNA expression levels of ALDH isoforms in the lungs obtained from BLM-treated mice transferred with CD45−/ALDHdim (n = 7) and CD45−/ALDHbr (n = 4) cells on day 14. Values are expressed relative to the expression of endogenous control β-actin mRNA. Data are shown as mean ± SEM. *P < 0.05. F Schematic summary of the retinol-metabolizing pathway. Circulating retinol/vitamin A is taken up into a cell via the cell membrane receptor (stimulated by retinoic acid 6, STRA6). It is converted into retinal/retinaldehyde within the cytoplasm, which is further converted into all-trans-retinoic acid (ATRA) by retinal dehydrogenase/retinaldehyde dehydrogenase (RALDH, ALDH1a family). Subsequently, it is transported into the nucleus by the cellular retinoic acid-binding protein (CRABP), where ATRA binds to the intranuclear retinoic acid receptor (RAR) and promotes gene transcription. G Real-time quantitative PCR analysis of the mRNA expression levels of retinol-metabolizing pathway-related genes in the lung tissues obtained from BLM-treated mice transferred with CD45−/ALDHdim (n = 7) and CD45−/ALDHbr (n = 4) cells on day 14. Values are expressed relative to the expression of the endogenous control β-actin mRNA. Data are shown as mean ± SEM. *P < 0.05. (H) Survival rate in high-dose BLM-treated mice transferred with PBS alone (n = 8), CD45−/ALDHdim (n = 8) cells, and CD45−/ALDHbr (n = 5) cells