Effect of keratinocyte growth factor on growth and transdifferentiation of primary alveolar epithelial type II cells

Background/aim: To investigate the effects of keratinocyte growth factor (KGF) on the growth and transdifferentiation of primary alveolar epithelial type II cells (AECIIs). Materials and methods: The number of primary AECIIs, their viability, and cell cycle and apoptosis were studied under KGF treatment using a hemocytometer, trypan blue exclusion, and flow cytometry, respectively. Positive expressions of surfactant protein C (SP-C), aquaporin 5 (AQP5), and thyroid transcription factor 1(TTF-1) were examined with indirect immunofluorescence; mRNA levels of SP-C, AQP5, and TTF-1 were determined by polymerase chain reaction. Results: In response to KGF treatment, cell numbers were significantly increased, more cells were blocked in the S phase, and fewer cells were apoptotic or necrotic on days 2 and 4, but there was little effect on cell viability. In addition, KGF treatment resulted in higher levels of SP-C on days 2 and 8 while lowering them on day 4, higher levels of AQP5 on day 4 while lowering them on day 8, and higher levels of TTF-1 on days 2, 6, and 8. Conclusion: KGF treatment promoted proliferation of AECIIs, inhibited cell apoptosis, promoted transdifferentiation of AECIIs, and induced alveolar epithelial type I cells to revert to AECIIs.