title: Activation of ENaC in collecting duct cells by prorenin and its receptor PRR: involvement of Nox4-derived hydrogen peroxide.
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. 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-trap analysis and reactive oxygen species (ROS)-Glo H2O2 assay, respectively. Both siRNA-mediated Nox4 knockdown and the dual Nox1/4 inhibitor GKT137892 attenuated prorenin-induced Ieq Overall, our results demonstrate that activation of PRR by prorenin stimulates ENaC activity in CD cells via Nox4-derived H2O2.
authors.affiliation: Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China; and Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Lu
authors.affiliation: Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China; and Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China; and Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah.
authors.forename: Mi
authors.initials: M
authors.lastname: Liu
authors.affiliation: Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China; and Tianxin.Yang@hsc.utah.edu.
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Yang
authors.affiliation: Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China; and.
authors.forename: Adam
authors.initials: A
authors.lastname: Nau
authors.affiliation: Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China; and.
authors.forename: Donald E
authors.initials: DE
authors.lastname: Kohan
authors.affiliation: Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China; and.
authors.forename: Van
authors.initials: V
authors.lastname: Reese
authors.affiliation: Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China; and.
authors.forename: Russell S
authors.initials: RS
authors.lastname: Richardson
authors.affiliation: Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China; and Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah.
authors.forename: Tianxin
authors.initials: T
authors.lastname: Yang
mesh_terms: D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D062686:Epithelial Sodium Channel Blockers / Q000494:pharmacology; D053503:Epithelial Sodium Channels / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007685:Kidney Tubules, Collecting / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012083:Renin / Q000494:pharmacology*; D000093342:Prorenin Receptor
chemical_list: D062686:Epithelial Sodium Channel Blockers; D053503:Epithelial Sodium Channels; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D011956:Receptors, Cell Surface; D000584:Amiloride; D006861:Hydrogen Peroxide; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C422943:Nox4 protein, mouse; D012083:Renin; D000093342:Prorenin Receptor
keywords: (pro)renin receptor; epithelial sodium channel; hydrogen peroxide; inner medullary collecting duct; renin activity