Curcumin induces stabilization of Nrf2 protein through Keap1 cysteine modification.

Curcumin induces stabilization of Nrf2 protein through Keap1 cysteine modification. Biochem Pharmacol. 2020 Jan 20;:113820 Authors: Shin JW, Chun KS, Kim DH, Kim SJ, Hoon Kim S, Cho NC, Na HK, Surh YJ Abstract The present study was aimed to investigate the effects of curcumin, a representative chemopreventive phytochemical with pronounced antioxidant and anti-inflammatory properties, on activation of Nrf2 and its target protein heme oxygenase-1 (HO-1) in mouse skin in vivo and in cultured murine epidermal cells. Treatment of mouse epidermal JB-6 cells with curcumin resulted in the induction of HO-1 expression, and this was abrogated in cells transiently transfected with Nrf2 siRNA. While curcumin treatment increased protein expression of Nrf2, it failed to did not alter the steady-state level of the Nrf2 mRNA transcript. Treatment of cells with curcumin stabilized Nrf2 by inhibiting ubiquitination and subsequent 26S proteasomal degradation of this transcription factor. Tetrahydrocurcumin, a non-electrophilic analogue of curcumin that lacks the α,β-unsaturated carbonyl group, failed to induce HO-1 expression as well as Nrf2 nuclear translocation of Nrf2 and its binding to the antioxidant/electrophile response elements. Cells transfected with a mutant Keap1 protein in which cysteine 151 is replaced by serine exhibited marked reduction in curcumin-induced Nrf2 transactivation. Mass spectrometric analysis revealed that curcumin binds t...
Source: Biochemical Pharmacology - Category: Drugs & Pharmacology Authors: Tags: Biochem Pharmacol Source Type: research