title: Regulation of transforming growth factor β1-dependent aldose reductase expression by the Nrf2 signal pathway in human mesangial cells.
abstract: Aldose reductase (AR) is a key enzyme in the alternative glucose metabolism pathway, the polyol pathway. To date, AR is known to be involved in several secondary complications of diabetes and various kidney diseases. The goal of this study was to elucidate how the Nrf2-anti-oxidant response element (ARE) signal pathway plays a role in TGFβ1's regulation of AR expression in human renal mesangial cells (HRMCs). As an in vitro model system, HRMCs were used to investigate AR mRNA by qPCR, protein by Western blot and enzymatic activity by spectrophotometric assay. The ability of TGFβ1 to induce reactive oxygen species (ROS) in cells was measured by electron-spin resonance (ESR) trapping method. Reporter assays were used to test the activity of the AR promoter region, and ChIP was employed to test the direct binding of Nrf2 with the endogenous AR promoter. Treatment of HRMCs with TGFβ1 up-regulated the expression of AR mRNA, protein, and activity level. Additionally, TGFβ1 rapidly increased cellular ROS levels, which in turn activated the Nrf2-ARE pathway. Either inhibition of ROS production or knockdown of Nrf2 in HRMCs decreased the TGFβ1-induction of AR expression. Nrf2 regulated AR luciferase activity specifically via two AREs within the AR promoter, and bound directly to the endogenous AR promoter. Furthermore, the TGFβ1-mediated expression of AR required Nrf2 and was significantly abrogated in Nrf2-/- cells. These data show the regulation of AR by TGFβ1 is induced by TGFβ1 stimulation of ROS, which activates the Nrf2-ARE pathway allowing Nrf2 to directly increase AR expression in HRMCs.
authors.affiliation: Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Tian
authors.forename: Samantha A
authors.initials: SA
authors.lastname: Whitman
authors.forename: Donna D
authors.initials: DD
authors.lastname: Zhang
authors.forename: Toru
authors.initials: T
authors.lastname: Nishinaka
authors.forename: Nong
authors.initials: N
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
mesh_terms: D000449:Aldehyde Reductase / Q000235:genetics / Q000378:metabolism*; D061745:Antioxidant Response Elements; D002460:Cell Line; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D050527:Mesangial Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species / Q000378:metabolism; D015533:Transcriptional Activation; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
chemical_list: D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D053773:Transforming Growth Factor beta1; D000449:Aldehyde Reductase