Fig. 7.

Ouabain inhibits expression of p21 and p27 in ADPKD cells, but not in normal human kidney cells. Cells were treated without or with 3 nM ouabain and were incubated for 24 h. A–D: ADPKD cells. A and B: RNA was isolated from the cells, subjected to RT-PCR for detection of p21 and p27 transcripts. C and D: nuclear fractions from the cells were prepared and subjected to immunoblot for quantification of p21 and p27 protein levels. E and F: p21 and p27 levels in nuclear fractions from normal kidney cells. C–F: detection of histone 3 (H3) was included as a loading control. Bars represent the level of protein expression after densitometric analysis of the blots. Values are means ± SE of 3 experiments using cells from 3 different ADPKD or normal kidneys. Significant differences compared with the untreated controls are shown; *P < 0.01.