TY - JOUR
T1 - Adaptive induction of NF-E2-related factor-2-driven antioxidant genes in endothelial cells in response to hyperglycemia
AU - Ungvari, Zoltan
AU - Bailey-Downs, Lora
AU - Gautam, Tripti
AU - Jimenez, Rosario
AU - Losonczy, Gyorgy
AU - Zhang, Cuihua
AU - Ballabh, Praveen
AU - Recchia, Fabio A.
AU - Wilkerson, Donald C.
AU - Sonntag, William E.
AU - Pearson, Kevin
AU - de Cabo, Rafael
AU - Csiszar, Anna
PY - 2011/4
Y1 - 2011/4
N2 - Hyperglycemia in diabetes mellitus promotes oxidative stress in endothelial cells, which contributes to development of cardiovascular diseases. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a transcription factor activated by oxidative stress that regulates expression of numerous reactive oxygen species (ROS) detoxifying and antioxidant genes. This study was designed to elucidate the homeostatic role of adaptive induction of Nrf2-driven free radical detoxification mechanisms in endothelial protection under diabetic conditions. Using a Nrf2/antioxidant response element (ARE)-driven luciferase reporter gene assay we found that in a cultured coronary arterial endothelial cell model hyperglycemia (10-30 mmol/l glucose) significantly increases transcriptional activity of Nrf2 and upregulates the expression of the Nrf2 target genes NQO1, GCLC, and HMOX1. These effects of high glucose were significantly attenuated by small interfering RNA (siRNA) downregulation of Nrf2 or overexpression of Keap-1, which inactivates Nrf2. High-glucose-induced upregulation of NQO1, GCLC, and HMOX1 was also prevented by pretreatment with polyethylene glycol (PEG)-catalase or N-acetylcysteine, whereas administration of H 2O 2 mimicked the effect of high glucose. To test the effects of metabolic stress in vivo, Nrf2 +/+ and Nrf2 -/- mice were fed a high-fat diet (HFD). HFD elicited significant increases in mRNA expression of Gclc and Hmox1 in aortas of Nrf2 +/+ mice, but not Nrf2 -/- mice, compared with respective standard diet-fed control mice. Additionally, HFD-induced increases in vascular ROS levels were significantly greater in Nrf2 -/- than Nrf2 +/+ mice. HFD-induced endothelial dysfunction was more severe in Nrf2 -/- mice, as shown by the significantly diminished acetylcholine-induced relaxation of aorta of these animals compared with HFD-fed Nrf2 +/+ mice. Our results suggest that adaptive activation of the Nrf2/ARE pathway confers endothelial protection under diabetic conditions.
AB - Hyperglycemia in diabetes mellitus promotes oxidative stress in endothelial cells, which contributes to development of cardiovascular diseases. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a transcription factor activated by oxidative stress that regulates expression of numerous reactive oxygen species (ROS) detoxifying and antioxidant genes. This study was designed to elucidate the homeostatic role of adaptive induction of Nrf2-driven free radical detoxification mechanisms in endothelial protection under diabetic conditions. Using a Nrf2/antioxidant response element (ARE)-driven luciferase reporter gene assay we found that in a cultured coronary arterial endothelial cell model hyperglycemia (10-30 mmol/l glucose) significantly increases transcriptional activity of Nrf2 and upregulates the expression of the Nrf2 target genes NQO1, GCLC, and HMOX1. These effects of high glucose were significantly attenuated by small interfering RNA (siRNA) downregulation of Nrf2 or overexpression of Keap-1, which inactivates Nrf2. High-glucose-induced upregulation of NQO1, GCLC, and HMOX1 was also prevented by pretreatment with polyethylene glycol (PEG)-catalase or N-acetylcysteine, whereas administration of H 2O 2 mimicked the effect of high glucose. To test the effects of metabolic stress in vivo, Nrf2 +/+ and Nrf2 -/- mice were fed a high-fat diet (HFD). HFD elicited significant increases in mRNA expression of Gclc and Hmox1 in aortas of Nrf2 +/+ mice, but not Nrf2 -/- mice, compared with respective standard diet-fed control mice. Additionally, HFD-induced increases in vascular ROS levels were significantly greater in Nrf2 -/- than Nrf2 +/+ mice. HFD-induced endothelial dysfunction was more severe in Nrf2 -/- mice, as shown by the significantly diminished acetylcholine-induced relaxation of aorta of these animals compared with HFD-fed Nrf2 +/+ mice. Our results suggest that adaptive activation of the Nrf2/ARE pathway confers endothelial protection under diabetic conditions.
KW - Diabetes
KW - Endothelial dysfunction
KW - Oxidative stress
UR - http://www.scopus.com/inward/record.url?scp=79955068967&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79955068967&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.00402.2010
DO - 10.1152/ajpheart.00402.2010
M3 - Article
C2 - 21217061
AN - SCOPUS:79955068967
SN - 0363-6135
VL - 300
SP - H1133-H1140
JO - American Journal of Physiology
JF - American Journal of Physiology
IS - 4
ER -
