Targeted genomic disruption of H-ras and N-ras has no effect on early renal changes after unilateral ureteral ligation

Purpose To assess the contribution of two different Ras monomeric GTPases isoforms H-and N-Ras in the early changes associated to obstructive nephropathy induced by unilateral ureteral obstruction (UUO). Methods UUO was performed in N-ras (N-ras(-/-)) and H-ras (H-ras(-/-)) knock-out mice and control (H-ras(+/+)/N-ras(+/+)) mice of C57B1/6 background. Fibronectin, alpha-smooth muscle actin, cleaved caspase-3, ki-67, Ras-GTP, pERK, and pAkt expression was analyzed by western blot and/or immunohistochemistry. Ras isoforms activation and caspase activity were determined by both western blot and ELISA. Results Three days after UUO, obstructed (O) kidneys of H-ras(-/-), N-ras(-/-) and H-ras(+/+)/ N-ras(+/+) mice showed no significant differences in activated total ras, pERK1/2, pAkt, total Akt levels, fibronectin, alpha-SMA expression, cell proliferation, and activated caspase-3. The morphological alterations in the O kidneys, revealed by histological and immunohistochemical studies, were also similar in H-ras(-/-), N-ras(-/-), and H-ras(+/+)/N-ras(+/+) mice. Conclusions These data suggest that the activation of H-ras and N-ras isoforms does not play a major role in the early renal damage induced by UUO.