The renin-angiotensin system and Wnt/frizzled receptor signaling pathways are important in the development of essential organs, and their aberrant activation results in cardiovascular and renal pathologies. The (pro)renin receptor ((P)RR)-bound (pro)renin is enzymatically active generating angiotensin-II and activating mitogen-activated protein kinases, leading to cell proliferation and to upregulation of profibrotic genes expression, resulting in end-organ damage. The (P)RR does more than bind to (pro)renin, because it is functionally linked to the vacuolar-H(+)-ATPase (v-H(+)-ATPase) that regulates pH of cellular and intracellular vesicles, and to Wnt signaling. This signaling pathway is essential for cell survival, embryonic development and has had a role in various disease states as evidenced by mutation or genetic ablation of the (P)RR gene. This suggests two types of functions of (P)RRs, first one as a receptor for (pro)renin and second one as an accessory subunit of the v-H(+)-ATPase and a cofactor of the Wnt/Fz receptor complex. This review will discuss both of these functions of (P)RRs thereby giving new perspectives as to the roles of (P)RRs in cardiovascular and renal pathologies.
