Fig. 3.

Expression of AT1 and AT2 cell markers changes over time in culture during in vitro transdifferentiation. A: immunoblot with AT1 and AT2 cell markers shows HOPX is highly expressed from day 1 and increases only minimally in culture. AQP5 is expressed at very low levels on day 1 and increases over time. NKX2.1 decreases as cells transdifferentiate to the AT1-like phenotype; n = 3. B: diagram of proposed sequence of temporal changes in AT1 and AT2 cell markers as AT2 cells transdifferentiate toward AT1-like cells. Pro-SP-C expression drops abruptly as cells begin to transdifferentiate while NKX2.1 expression declines more slowly as cells progress though the intermediate (transitional) cell time period.