title: Nox2 is a mediator of chronic CsA nephrotoxicity.
abstract: We hypothesized that Nox2, the classical phagocytic NADPH oxidase, plays an important role in calcineurin inhibitor (CNI)-induced renal fibrosis. We tested this hypothesis in vitro, in animal and in human studies. Cyclosporine A (CsA) and tacrolimus (TAC) were associated with greater levels of Nox2 mRNA and epithelial to mesenchymal transition (EMT) in NRK52E cells. CsA increased Nox2, α-SMA and phosphorylated-p38MAPK, Smad3 and NFκB proteins. Nox2 upregulation and EMT were inhibited in TGF-β1 knockout cells suggesting that TGF-β1 is required for Nox2 activation. Fisher344 rats treated with high dose CsA showed increased Nox2 in the tubulointerstitium and greater Nox2, α-SMA, phosphorylated Smad3 and nitrotyrosine by immunoblot analyses. Inhibition of Nox2 by coadministration of apocynin or diphenyleneiodonium was associated with reduced fibrogenesis. We validated these findings by treating wild type and Nox2 null (B6.129S-Cybb(Tm1Din)/J) mice with high dose CsA. Western blot analyses confirmed the absence of Nox2 and significantly lower levels of α-SMA and 4-hydroxynonenal (HNE) in CsA-treated knockout mice. These findings were clinically relevant since Nox2 and α-SMA were increased in the tubulointerstitium of kidneys from 15 liver transplant recipients with biopsy-confirmed chronic CsA or TAC nephrotoxicity. In conclusion, specific Nox2 inhibition strategies may improve chronic CNI nephrotoxicity in solid organ transplantation.
authors.affiliation: Division of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA. axd@medicine.wisc.edu
authors.forename: A
authors.initials: A
authors.lastname: Djamali
authors.forename: S
authors.initials: S
authors.lastname: Reese
authors.forename: O
authors.initials: O
authors.lastname: Hafez
authors.forename: A
authors.initials: A
authors.lastname: Vidyasagar
authors.forename: L
authors.initials: L
authors.lastname: Jacobson
authors.forename: W
authors.initials: W
authors.lastname: Swain
authors.forename: C
authors.initials: C
authors.lastname: Kolehmainen
authors.forename: L
authors.initials: L
authors.lastname: Huang
authors.forename: N A
authors.initials: NA
authors.lastname: Wilson
authors.forename: J R
authors.initials: JR
authors.lastname: Torrealba
mesh_terms: D000818:Animals; D065095:Calcineurin Inhibitors; D002908:Chronic Disease; D016572:Cyclosporine / Q000009:adverse effects*; D058750:Epithelial-Mesenchymal Transition; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D016031:Liver Transplantation; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011916:Rats, Inbred F344; D060888:Real-Time Polymerase Chain Reaction; D016559:Tacrolimus / Q000494:pharmacology; D053773:Transforming Growth Factor beta1 / Q000502:physiology
chemical_list: D065095:Calcineurin Inhibitors; D007166:Immunosuppressive Agents; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D016572:Cyclosporine; C500593:Cybb protein, rat; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D016559:Tacrolimus