title: Involvement of renin-angiotensin-aldosterone system in calcium oxalate crystal induced activation of NADPH oxidase and renal cell injury.
abstract: OBJECTIVE
  Reactive oxygen species (ROS) are produced during the interaction between oxalate/calcium oxalate monohydrate (COM) crystals and renal epithelial cells and are responsible for the various cellular responses through the activation of NADPH oxidase (Nox). Ox and COM also activate the renin-angiotensin-aldosterone system (RAAS). Aldosterone stimulates ROS production through activation of Nox with the involvement of mineralocorticoid receptor (MR), Rac1 and mitogen-activated protein kinases (MAPK). We investigated RAAS pathways in vivo in an animal model of hyperoxaluria and in vitro by exposing renal epithelial cells to COM crystals.
  
  
  METHODS
  Hyperoxaluria was induced in male SD rats by administering ethylene glycol. One group of rats was additionally given spironolactone. Total RNA was extracted and subjected to genomic microarrays to obtain global transcriptome data. Normal rat kidney cell line (NRK-52E) was incubated with aldosterone(10(-7) M) and COM(67 μg/cm(2)) with or without spironolactone(10(-5) M), a selective inhibitor of SRC family of kinases; protein phosphatase 2(pp2) (10(-5) M) and Nox inhibitor; diphenylene iodonium (DPI) (10(-5) M).
  
  
  RESULTS
  Relative expression of genes encoding for AGT, angiotensin receptors 1b and 2, Renin 1, Cyp11b, HSD11B2, Nr3c2, NOx4 and Rac1 was upregulated in the kidneys of rats with hyperoxaluria. Treatment with spironolactone reversed the effect of hyperoxaluria. Both aldosterone and COM crystals activated Nox and Rac1 expression in NRK52E, while spironolactone inhibited Nox and Rac1 expression. Increased Rac1 expression was significantly attenuated by treatment with PP2 and spironolactone.
  
  
  CONCLUSIONS
  Results indicate that hyperoxaluria-induced production of ROS, injury and inflammation are in part associated with the activation of Nox through renin-angiotensin-aldosterone pathway.
authors.affiliation: Department of Urology, Faculty of Medicine, Kinki University, 377-2 Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan.|Department of Pathology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Tsuji
authors.affiliation: Department of Pathology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Pathology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Joshi
authors.initials: J
authors.lastname: Sunil
authors.affiliation: Department of Urology, Faculty of Medicine, Kinki University, 377-2 Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan. nsimizu810@yahoo.co.jp.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Shimizu
authors.affiliation: Department of Urology, Faculty of Medicine, Kinki University, 377-2 Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yoshimura
authors.affiliation: Department of Urology, Faculty of Medicine, Kinki University, 377-2 Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Uemura
authors.affiliation: Department of Pathology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Ammon B
authors.initials: AB
authors.lastname: Peck
authors.affiliation: Department of Pathology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Saeed R
authors.initials: SR
authors.lastname: Khan
mesh_terms: D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D000808:Angiotensinogen / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002129:Calcium Oxalate / Q000378:metabolism*; D002460:Cell Line; D019405:Cytochrome P-450 CYP11B2 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019855:Ethylene Glycol / Q000633:toxicity; D020869:Gene Expression Profiling; D006959:Hyperoxaluria / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D008297:Male; D000451:Mineralocorticoid Receptor Antagonists / Q000494:pharmacology; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D009861:Onium Compounds / Q000494:pharmacology; D054648:Protein Phosphatase 2 / Q000494:pharmacology; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011945:Receptors, Angiotensin / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018161:Receptors, Mineralocorticoid / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012083:Renin / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000235:genetics*; D013148:Spironolactone / Q000494:pharmacology; D013252:Steroid 11-beta-Hydroxylase / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
chemical_list: C534933:Agt protein, rat; D004791:Enzyme Inhibitors; D000451:Mineralocorticoid Receptor Antagonists; D009861:Onium Compounds; D012333:RNA, Messenger; D011945:Receptors, Angiotensin; D018161:Receptors, Mineralocorticoid; D000808:Angiotensinogen; D002129:Calcium Oxalate; D013148:Spironolactone; C007517:diphenyleneiodonium; D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2; D019405:Cytochrome P-450 CYP11B2; D013252:Steroid 11-beta-Hydroxylase; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498911:Nox4 protein, rat; D054648:Protein Phosphatase 2; D012083:Renin; C499134:Rac1 protein, rat; D020830:rac1 GTP-Binding Protein; D019855:Ethylene Glycol
keywords: Aldosterone; Mineralcorticoid receptor; NADPH oxidase; Rac1; Spironolactone