Activation of ENaC in Collecting Duct Cells by Prorenin and Its Receptor PRR: Involvement of Nox4-Derived Hydrogen Peroxide.

Activation of ENaC in Collecting Duct Cells by Prorenin and Its Receptor PRR: Involvement of Nox4-Derived Hydrogen Peroxide. Am J Physiol Renal Physiol. 2015 Dec 23;:ajprenal.00492.2015 Authors: Lu X, Wang F, Liu M, Yang KT, Nau A, Kohan DE, Reese VR, Richardson RS, Yang T Abstract The collecting duct (CD) has been recognized as an important source of prorenin/renin and it also expresses (pro)renin receptor (PRR). The goal of this study was to examine the hypothesis that prorenin or renin via PRR regulates epithelial Na(+) channel (ENaC) activity in mpkCCD cells. Transepithelial Na(+) transport was measured by using a conventional epithelial volt-ohmmeter and was expressed as the calculated equivalent current (Ieq). Amiloride-inhibitable Ieq was used as a reflection of ENaC activity. Administration of prorenin in the nanomolar range induced a significant increase in Ieq that was detectable as early as 1 min, peaked at 5 min, and gradually returned to baseline within 15 min. These changes in Ieq were completely prevented by a newly developed PRR decoy inhibitor, PRO20. Prorenin-induced Ieq was inhibitable by amiloride. As compared with prorenin, renin was less effective in stimulating Ieq. Prorenin-induced Ieq was attenuated by apocynin but enhanced by Tempol, the latter effect being prevented by catalase. In response to prorenin treatment, the levels of total reactive oxygen species and H2O2 were both increased, as detected by spin-t...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Tags: Am J Physiol Renal Physiol Source Type: research