title: Mitochondrial dysfunction mediates aldosterone-induced podocyte damage: a therapeutic target of PPARγ.
abstract: Aldosterone (Aldo) causes podocyte damage by an unknown mechanism. We examined the role of mitochondrial dysfunction (MtD) in Aldo-treated podocytes in vitro and in vivo. Exposure of podocytes to Aldo reduced nephrin expression dose dependently, accompanied by increased production of reactive oxygen species (ROS). The ROS generation and podocyte damage were abolished by the mitochondrial (mt) respiratory chain complex I inhibitor rotenone. Pronounced MtD, including reduced mt membrane potential, ATP levels, and mtDNA copy number were seen in Aldo-treated podocytes and in the glomeruli of Aldo-infused mice. The mineralocorticoid receptor antagonist eplerenone significantly inhibited Aldo-induced MtD. The MtD was associated with higher levels of ROS, reduction in the activity of complexes I, III, and IV, and expression of the peroxisome proliferator-activated receptor-γ (PPARγ) coactivator-1α and mt transcription factor A. Both the PPARγ agonist rosiglitazone and PPARγ overexpression protected against podocyte injury by preventing MtD and oxidative stress, as evidenced by reduced ROS production, by maintenance of mt morphology, by restoration of mtDNA copy number, by decrease in mt membrane potential loss, and by recovery of mt electron transport function. The protective effect of rosiglitazone was abrogated by the specific PPARγ small interference RNA, but not a control small interference RNA. We conclude that MtD is involved in Aldo-induced podocyte injury, and that the PPARγ agonist rosiglitazone may protect podocytes from this injury by improving mitochondrial function.
authors.affiliation: Department of Nephrology, Nanjing Children's Hospital, Affiliated to Nanjing Medical University, Nanjing, China.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Zhu
authors.forename: Songming
authors.initials: S
authors.lastname: Huang
authors.forename: Yanggang
authors.initials: Y
authors.lastname: Yuan
authors.forename: Guixia
authors.initials: G
authors.lastname: Ding
authors.forename: Ronghua
authors.initials: R
authors.lastname: Chen
authors.forename: Bicheng
authors.initials: B
authors.lastname: Liu
authors.forename: Tianxin
authors.initials: T
authors.lastname: Yang
authors.forename: Aihua
authors.initials: A
authors.lastname: Zhang
mesh_terms: D000450:Aldosterone / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D004272:DNA, Mitochondrial / Q000187:drug effects / Q000378:metabolism; D007674:Kidney Diseases / Q000378:metabolism / Q000473:pathology*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000502:physiology; D008565:Membrane Proteins / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D047495:PPAR gamma / Q000378:metabolism*; D050199:Podocytes / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: D004272:DNA, Mitochondrial; D008565:Membrane Proteins; D047495:PPAR gamma; D017382:Reactive Oxygen Species; C113267:nephrin; D000450:Aldosterone