Fig. 2.
EGFR activation and a disintegrin and metalloprotease 17 (ADAM17) augmentation by chronic Ang II infusion. A: compared with saline-infused mice, Ang II infusion increased kidney phospho-EGFR (p-EGFR) levels in both HBlox/lox and HBendo−/− mice, with the latter having much lower levels of p-EGFR. The total amount of EGFR was almost identical in all groups. Levels of ADAM17 were also increased in Ang II-infused kidneys compared with saline-infused groups. B and C: densitometric analysis of the Western blot bands in A expressed as p-EGFR/EGFR and ADAM17/β-actin. *P < 0.05 compared with normal saline infusions; ^P < 0.05 compared with Ang II-infused mice with endothelial HB-EGF deletion. Values represent the mean and SE of at least 3 independent experiments (n = 6–7 in each group). D: 8 wk after chronic Ang II infusion, increased p-EGFR immunostaining was seen in glomeruli, proximal tubules, perivascular infiltrating cells, and smooth muscle cells in the large blood vessels in the control HBlox/lox mice, with significantly decreased expression in HBendo−/− mouse kidneys. No p-EGFR immunostaining was detected in saline-infused groups.