Epalrestat Upregulates Heme Oxygenase-1, Superoxide Dismutase, and Catalase in Cells of the Nervous System

Biol Pharm Bull. 2016 Sep 1;39(9):1523-30. doi: 10.1248/bpb.b16-00332. Epub 2016 Jul 21.

Abstract

Heme oxygenase (HO)-1 has potent antioxidant and anti-inflammatory functions. Recent studies have shown that the upregulation of HO-1 is beneficial to counteract neuroinflammation, making HO-1 a new therapeutic target for neurological diseases. We have reported that epalrestat (EPS), which is currently used for the treatment of diabetic neuropathy, increases HO-1 levels through the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) in bovine aortic endothelial cells. In this study, we tested the hypothesis that EPS upregulates HO-1 via Nrf2 activation in the component cells of the nervous system, by using rat Schwann cells and human SH-SY5Y cells. Treatment of Schwann cells with EPS at near-plasma concentration led to a dramatic increase in HO-1 levels. Nrf2 knockdown by small interfering RNA (siRNA) suppressed the EPS-induced HO-1 expression. EPS did not promote the intracellular accumulation of free ferrous ion and reactive oxygen species, by increasing ferritin via Nrf2 during HO-1 induction. Moreover, EPS stimulated the expression of superoxide dismutase 1 and catalase, which also are Nrf2 target gene products. It also markedly increased HO-1 levels in SH-SY5Y cells through the activation of Nrf2. We demonstrated for the first time that EPS upregulates HO-1, superoxide dismutase, and catalase by activating Nrf2. We suggest that EPS has the potential to prevent several neurological diseases.

MeSH terms

  • Aldehyde Reductase / antagonists & inhibitors
  • Animals
  • Catalase / genetics*
  • Catalase / metabolism
  • Cell Line, Tumor
  • Ferritins / metabolism
  • Heme Oxygenase-1 / genetics*
  • Heme Oxygenase-1 / metabolism
  • Humans
  • Iron / metabolism
  • NF-E2-Related Factor 2 / genetics
  • NF-E2-Related Factor 2 / metabolism
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / genetics
  • Rats
  • Reactive Oxygen Species / metabolism
  • Rhodanine / analogs & derivatives*
  • Rhodanine / pharmacology
  • Schwann Cells / drug effects*
  • Schwann Cells / metabolism
  • Superoxide Dismutase / genetics*
  • Superoxide Dismutase / metabolism
  • Thiazolidines / pharmacology*
  • Up-Regulation

Substances

  • NF-E2-Related Factor 2
  • RNA, Messenger
  • RNA, Small Interfering
  • Reactive Oxygen Species
  • Thiazolidines
  • epalrestat
  • Rhodanine
  • Ferritins
  • Iron
  • Aldehyde Reductase
  • Catalase
  • Heme Oxygenase-1
  • Superoxide Dismutase