Radiation Induces Pulmonary Fibrosis by Promoting the Fibrogenic Differentiation of Alveolar Stem Cells

Figure 1

The lung cell differentiation and the effects of radiation exposure on LSCs and alveolar cells. (a) Workflow and time line of in vitro lung cell differentiation experiments. LSCs were isolated from neonatal ICR mice and then sequentially differentiated into alveolar cells by culture with MCDB-201 medium. LSCs, AECII, and AECI cells were examined through immunostaining with anti-CD157, anti-pro-SP-C, and anti-T1α antibodies. Scale bars, 100 μm. (b) Cell numbers of irradiated LSCs and alveolar cells were examined at day 3 postirradiation. The results are represented as (, ) relative to initial cell number. (c) Immunostaining of γ-H2AX expression (green, left panels) and nuclear morphology (blue, right panels) in LSCs and alveolar cells that received 8 Gy at 1 h and 16 h. (d) The lung cells repair radiation-induced DNA double-strand breaks as determined by nuclear foci formation of γ-H2AX. The nuclear γ-H2AX foci per cell are from LSCs and AECII cells () or AECI cells () relative to the initial sample. (e) The cell morphology of irradiated lung cells at day 3 postirradiation. Scale bars, 100 μm. (f) The cell differentiation of irradiated lung stem cells was examined at day 3 postirradiation by immunostaining with specific protein markers CD157, SP-C, or T1α. Scale bars, 100 μm.

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