TY - JOUR
T1 - Withaferin A induces heme oxygenase (HO-1) expression in endothelial cells via activation of the Keap1/Nrf2 pathway
AU - Heyninck, Karen
AU - Sabbe, Linde
AU - Chirumamilla, Chandra Sekhar
AU - Szic, Katarzyna Szarc Vel
AU - Veken, Pieter Vander
AU - Lemmens, Kristien J. A.
AU - Lahtela-Kakkonen, Maija
AU - Naulaerts, Stefan
AU - de Beeck, Ken Op
AU - Laukens, Kris
AU - Van Camp, Guy
AU - Weseler, Antje R.
AU - Bast, Aalt
AU - Haenen, Guido R. M. M.
AU - Haegeman, Guy
AU - Berghe, Wim Vanden
PY - 2016/6/1
Y1 - 2016/6/1
N2 - Withaferin A (WA), a natural phytochemical derived from the plant Withania somnifera, is a well-studied bioactive compound exerting a broad spectrum of health promoting effects. To gain better insight in the potential therapeutic capacity of WA, we evaluated the transcriptional effects of WA on primary human umbilical vein endothelial cells (HUVECs) and an endothelial cell line (EA.hy926). RNA microarray analysis of WA treated HUVEC cells demonstrated increased expression of the antioxidant gene heme oxygenase (HO-1). Transcriptional regulation of this gene is strongly dependent on the transcription factor NF-E2-related factor 2 (Nrf2), which senses chemical changes in the cell and coordinates transcriptional responses to maintain chemical homeostasis via expression of antioxidant genes and cytoprotective Phase II detoxifying enzymes. Under normal conditions, Nrf2 is kept in the cytoplasm by Kelch-like ECH-associated protein 1 (Keap1), an adaptor protein controlling the half-life of Nrf2 via constant proteasomal degradation. In this study we demonstrate that WA time- and concentration-dependently induces HO-1 expression in endothelial cells via upregulation and increased nuclear translocation of Nrf2. According to the crucial negative regulatory role of Keap1 in Nrf2 expression levels, a direct interaction of WA with Keap1 could be demonstrated. In vitro and in silico evaluations suggest that specific cysteine residues in Keap1 might be involved in the interaction with WA.
AB - Withaferin A (WA), a natural phytochemical derived from the plant Withania somnifera, is a well-studied bioactive compound exerting a broad spectrum of health promoting effects. To gain better insight in the potential therapeutic capacity of WA, we evaluated the transcriptional effects of WA on primary human umbilical vein endothelial cells (HUVECs) and an endothelial cell line (EA.hy926). RNA microarray analysis of WA treated HUVEC cells demonstrated increased expression of the antioxidant gene heme oxygenase (HO-1). Transcriptional regulation of this gene is strongly dependent on the transcription factor NF-E2-related factor 2 (Nrf2), which senses chemical changes in the cell and coordinates transcriptional responses to maintain chemical homeostasis via expression of antioxidant genes and cytoprotective Phase II detoxifying enzymes. Under normal conditions, Nrf2 is kept in the cytoplasm by Kelch-like ECH-associated protein 1 (Keap1), an adaptor protein controlling the half-life of Nrf2 via constant proteasomal degradation. In this study we demonstrate that WA time- and concentration-dependently induces HO-1 expression in endothelial cells via upregulation and increased nuclear translocation of Nrf2. According to the crucial negative regulatory role of Keap1 in Nrf2 expression levels, a direct interaction of WA with Keap1 could be demonstrated. In vitro and in silico evaluations suggest that specific cysteine residues in Keap1 might be involved in the interaction with WA.
KW - Antioxidant
KW - Endothelial cell
KW - Molecular pharmacology
KW - Phytochemical
KW - Signal transduction
KW - Transcription regulation
U2 - 10.1016/j.bcp.2016.03.026
DO - 10.1016/j.bcp.2016.03.026
M3 - Article
C2 - 27045103
SN - 0006-2952
VL - 109
SP - 48
EP - 61
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
ER -