Ontogeny of the (pro)renin receptor.

Background: This study examined temporal expression of the (pro)renin receptor ((P)RR), during renal, heart, lung, and brain organogenesis in the mouse.

Methods: (P)RR expression was determined by quantitative reverse-transcription PCR, western blotting, and immunohistochemistry.

Results: Brain, kidney, and lung (P)RR mRNA levels increased progressively during gestation and peak on postnatal day (P)10. (P)RR protein contents were high during gestation in all organs studied and declined with maturation. Brain (P)RR was expressed most prominently in the ependymal lining of the ventricles. In the embryonic day (E)16.5 and E18.5 metanephros, (P)RR was present in the ureteric bud and ureteric bud-derived collecting ducts. In the fetal heart, (P)RR was expressed diffusely in the myocardium, whereas pulmonary (P)RR was detected at highest levels in the epithelium of branching airways. Treatment of newborn kidneys with the angiotensin (Ang) II type 1 receptor (AT₁R) antagonist candesartan increased (P)RR mRNA levels.

Conclusion: (P)RR gene and protein expressions in the brain, kidney, heart, and lung are developmentally regulated in a tissue-specific manner. Endogenous Ang II, acting via the AT₁R, exerts a negative feedback on (P)RR in the newborn kidney. These findings suggest that high (P)RR protein levels observed during gestation may play a role in brain, kidney, heart, and lung organogenesis.