title: The protective role of Nrf2 in streptozotocin-induced diabetic nephropathy.
abstract: OBJECTIVE
  Diabetic nephropathy is one of the major causes of renal failure, which is accompanied by the production of reactive oxygen species (ROS). Nrf2 is the primary transcription factor that controls the antioxidant response essential for maintaining cellular redox homeostasis. Here, we report our findings demonstrating a protective role of Nrf2 against diabetic nephropathy.
  
  
  METHODS
  We explore the protective role of Nrf2 against diabetic nephropathy using human kidney biopsy tissues from diabetic nephropathy patients, a streptozotocin-induced diabetic nephropathy model in Nrf2(-/-) mice, and cultured human mesangial cells.
  
  
  RESULTS
  The glomeruli of human diabetic nephropathy patients were under oxidative stress and had elevated Nrf2 levels. In the animal study, Nrf2 was demonstrated to be crucial in ameliorating streptozotocin-induced renal damage. This is evident by Nrf2(-/-) mice having higher ROS production and suffering from greater oxidative DNA damage and renal injury compared with Nrf2(+/+) mice. Mechanistic studies in both in vivo and in vitro systems showed that the Nrf2-mediated protection against diabetic nephropathy is, at least, partially through inhibition of transforming growth factor-beta1 (TGF-beta1) and reduction of extracellular matrix production. In human renal mesangial cells, high glucose induced ROS production and activated expression of Nrf2 and its downstream genes. Furthermore, activation or overexpression of Nrf2 inhibited the promoter activity of TGF-beta1 in a dose-dependent manner, whereas knockdown of Nrf2 by siRNA enhanced TGF-beta1 transcription and fibronectin production.
  
  
  CONCLUSIONS
  This work clearly indicates a protective role of Nrf2 in diabetic nephropathy, suggesting that dietary or therapeutic activation of Nrf2 could be used as a strategy to prevent or slow down the progression of diabetic nephropathy.
authors.affiliation: Department of Pharmacology and Toxicology, University of Arizona, Tucson, Arizona, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Zheping
authors.initials: Z
authors.lastname: Huang
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Lin
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Deyu
authors.initials: D
authors.lastname: Fang
authors.forename: Donna D
authors.initials: DD
authors.lastname: Zhang
mesh_terms: D000419:Albuminuria / Q000235:genetics; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003404:Creatinine / Q000652:urine; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000517:prevention & control*; D003928:Diabetic Nephropathies / Q000235:genetics / Q000517:prevention & control*; D017930:Genes, Reporter; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D051267:NF-E2-Related Factor 2 / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D011507:Proteinuria / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D014162:Transfection
chemical_list: D001786:Blood Glucose; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D034741:RNA, Small Interfering; D003404:Creatinine