title: Vascular versus tubular renin: role in kidney development.
abstract: Renin, the key regulated enzyme of the renin-angiotensin system regulates blood pressure, fluid-electrolyte homeostasis, and renal morphogenesis. Whole body deletion of the renin gene results in severe morphological and functional derangements, including thickening of renal arterioles, hydronephrosis, and inability to concentrate the urine. Because renin is found in vascular and tubular cells, it has been impossible to discern the relative contribution of tubular versus vascular renin to such a complex phenotype. Therefore, we deleted renin independently in the vascular and tubular compartments by crossing Ren1(c fl/fl) mice to Foxd1-cre and Hoxb7-cre mice, respectively. Deletion of renin in the vasculature resulted in neonatal mortality that could be rescued with daily injections of saline. The kidneys of surviving mice showed the absence of renin, hypertrophic arteries, hydronephrosis, and negligible levels of plasma renin. In contrast, lack of renin in the collecting ducts did not affect kidney morphology, intra-renal renin, or circulating renin in basal conditions or in response to a homeostatic stress, such as sodium depletion. We conclude that renin generated in the renal vasculature is fundamental for the development and integrity of the kidney, whereas renin in the collecting ducts is dispensable for normal kidney development and cannot compensate for the lack of renin in the vascular compartment. Further, the main source of circulating renin is the kidney vasculature.
authors.affiliation: Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia; and msl7u@virginia.edu.
authors.forename: Maria Luisa S
authors.initials: ML
authors.lastname: Sequeira-Lopez
authors.affiliation: Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia; and.
authors.forename: Vidya K
authors.initials: VK
authors.lastname: Nagalakshmi
authors.affiliation: Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia; and.
authors.forename: Minghong
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Pharmacology, University of Iowa Hospitals and Clinics Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa.
authors.forename: Curt D
authors.initials: CD
authors.lastname: Sigmund
authors.affiliation: Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia; and.
authors.forename: R Ariel
authors.initials: RA
authors.lastname: Gomez
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000378:metabolism*; D001835:Body Weight; D051858:Forkhead Transcription Factors / Q000235:genetics; D005838:Genotype; D018398:Homeodomain Proteins / Q000235:genetics; D007668:Kidney / Q000254:growth & development*; D007684:Kidney Tubules / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009929:Organ Size; D012083:Renin / Q000235:genetics* / Q000378:metabolism*; D012084:Renin-Angiotensin System / Q000235:genetics / Q000502:physiology
chemical_list: D051858:Forkhead Transcription Factors; C489562:Foxd1 protein, mouse; D018398:Homeodomain Proteins; C093253:Hoxb7 protein, mouse; D012083:Renin
keywords: arterioles; conditional knockout; medulla; renin angiotensin system