Figure 1.

AREG is expressed by renal resident cells and upregulated during NTN. (A) Time course of renal AREG mRNA expression after induction of NTN relative to baseline levels. (B) Overview of renal mRNA expression of the seven known EGFR ligands during NTN. (C) ELISA analyses of soluble AREG protein in the serum at the indicated time points of NTN. (D and E) AREG mRNA expression by cultured (D) mesangial and (E) proximal tubule cells after 6 hours of in vitro stimulation with AREG at the indicated concentrations. (F and G) Levels of soluble AREG protein in the supernatant of cultured (F) mesangial and (G) proximal tubule cells, 20 hours after initial 6-hour in vitro stimulation with AREG. Symbols represent individual animals, horizontal lines show mean values. *P<0.05; ***P<0.001.