Figure 3.

AR, EGF, HB-EGF, EGFR, and ErbB4 expression in cystic bpk mice and noncystic littermates, TGF-α present or absent. Whole kidney lysates from d-21 cystic (C) and noncystic (N) mice with TGF-α (TGF-α present) or without (TGF-α null) were prepared as described in the text. Western analysis for AR, EGF, HB-EGF, EGFR, and ErbB4 protein expression was performed, also as described. AR and HB-EGF whole kidney lysates were subjected to heparin column purification before loading. Recombinant purified growth factor was loaded as a positive control for EGF-related growth factor immunoblots. Expression of AR, EGF, HB-EGF, EGFR, and ErbB4 is increased to similar degrees in cystic mice with or without TGF-α when compared with their noncystic counterparts.