title: Activation of the Nrf2-ARE pathway attenuates hyperglycemia-mediated injuries in mouse podocytes.
abstract: BACKGROUND
  Damage to podocytes caused by excessive reactive oxygen species (ROS) contributes to onset and progression of diabetic kidney disease (DKD). Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a redox-sensing transcription factor that can induce the expression of antioxidant enzymes. We explored whether activation of Nrf2 pathway attenuated hyperglycemia-induced injuries in mouse podocytes.
  
  
  METHODS
  Tert-Butylhydroquinone (tBHQ) and small interfering RNAs (siRNAs) were used to regulate Nrf2 expression. Apoptosis and intracellular superoxide anion production were measured by flow cytometry. The activity of the Nrf2 antioxidant pathway was measured by an antioxidant response element (ARE)-driven luciferase reporter gene assay, and Nrf2 expression was assessed by real-time PCR and western blot analyses.
  
  
  RESULTS
  Podocytes incubated with high-glucose (HG) medium had higher intracellular superoxide anion and hydrogen peroxide production, higher apoptosis rate, higher bovine serum albumin (BSA) permeability and lower synaptopodin expression compared with podocytes exposed normal glucose (NG) (p<0.05). tBHQ increased the activity of the Nrf2 antioxidant pathway and enhanced nuclear Nrf2 expression, reduced intracellular superoxide anion and hydrogen peroxide production, apoptosis rate and BSA permeability, and restored synaptopodin expression in podocytes exposed to HG (p<O.05). Podocytes with Nrf2 siRNAs showed higher intracellular superoxide anion and hydrogen peroxide production, apoptosis and BSA permeability as well as lower synaptopodin expression compared with podocytes exposed to HG (p<0.05).
  
  
  CONCLUSIONS
  Our findings suggest that protection against activation of the Nrf2-ARE pathway in podocytes exposed to hyperglycemia. Thus, regulation of the Nrf2-ARE pathway could be a therapeutic option to combat oxidative stress and inhibit the development of DKD.
authors.affiliation: Division of Nephrology, Department of Medicine, the 3rd Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.forename: CuiCui
authors.initials: C
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Peng
authors.forename: Zengchun
authors.initials: Z
authors.lastname: Ye
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Xun
authors.initials: X
authors.lastname: Liu
authors.forename: Tanqi
authors.initials: T
authors.lastname: Lou
mesh_terms: D000818:Animals; D001483:Base Sequence; D005786:Gene Expression Regulation / Q000187:drug effects; D005947:Glucose / Q000008:administration & dosage / Q000009:adverse effects; D006873:Hydroquinones / Q000494:pharmacology; D006943:Hyperglycemia / Q000378:metabolism*; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D050199:Podocytes / Q000187:drug effects* / Q000378:metabolism; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D006873:Hydroquinones; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; C018855:2-tert-butylhydroquinone; D005947:Glucose