Fluvastatin protects vascular smooth muscle cells against oxidative stress through the Nrf2-dependent antioxidant pathway.
OBJECTIVE
HMG-CoA reductase inhibitors (statins) have pleiotropic actions, including the ability to reduce vascular oxidative stress. Transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) is an important regulator of cellular oxidative stress. This study examined the role of Nrf2 in statin-mediated antioxidant effects in vascular smooth muscle cells.


RESULTS
In cultured human coronary artery smooth muscle cells (hCASMCs), fluvastatin activated the nuclear translocation of Nrf2, as evaluated by Western blotting and immunocytochemical analyses. Nrf2-antioxidant response element (ARE) activity was measured with a luciferase assay after transfection of reporter plasmids containing AREs. Fluvastatin significantly increased the transcriptional activity of the ARE. Electromobility shift assays using an ARE probe detected a complex that was significantly increased in intensity by fluvastatin. Western blotting and luciferase assay revealed fluvastatin activated Nrf2 via the PI3K/Akt pathway. Statins upregulated the Nrf2-related antioxidant genes heme oxygenase-1, NAD(P)H quinone oxidoreductase-1, and glutamate-cysteine ligase modifier subunits. Inhibition of Nrf2 by siRNA reduced statin-induced upregulation of these antioxidant genes. Moreover, Nrf2 siRNA markedly reduced the cytoprotective effects of fluvastatin against H(2)O(2) administration in hCASMCs.


CONCLUSIONS
Fluvastatin exerts cytoprotective effects against oxidative stress, inducing antioxidant genes through Nrf2/ARE in hCASMCs. These results suggest that the Nrf2/ARE pathway plays an important role in the regulation of statin-mediated antioxidant effects in vascular smooth muscle cells.
Makabe
Shin
S
Department of Cardiovascular and Respiratory Medicine, Akita University Graduate School of Medicine, 1-1-1 Hondoh, Akita 010-8543, Japan.
Takahashi
Yoichiro
Y
Watanabe
Hiroyuki
H
Murakami
Manabu
M
Ohba
Takayoshi
T
Ito
Hiroshi
H
D000975:Antioxidants / Q000494:pharmacology*; D002478:Cells, Cultured; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology*; D000077340:Fluvastatin; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000378:metabolism; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000502:physiology*; D018384:Oxidative Stress / Q000187:drug effects*; D020218:Response Elements / Q000502:physiology
D000975:Antioxidants; D005229:Fatty Acids, Monounsaturated; D007211:Indoles; D051267:NF-E2-Related Factor 2; D000077340:Fluvastatin; D051547:Heme Oxygenase-1; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human; C546365:GCLM protein, human; D005721:Glutamate-Cysteine Ligase