Fluvastatin protects vascular smooth muscle cells against oxidative stress through the Nrf2-dependent antioxidant pathway.
ABSTRACT 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.
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.
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.
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ABSTRACT: ABSTRACT Significance - Heme oxygenase-1 (HMOX1) plays a critical role in the protection of cells and the inducible enzyme is implicated in a spectrum of human diseases. The increasing prevalence of cardiovascular and metabolic morbidities, for which current treatment approaches are not optimal, emphasizes the necessity to better understand key players such as HMOX1 that may be therapeutic targets. Recent Advances - HMOX1 is a dynamic protein that can undergo post-translational and structural modifications that modulate HMOX1 function. Moreover, trafficking from the endoplasmic reticulum to other cellular compartments, including the nucleus, highlights that HMOX1 may have roles other than the catabolism of heme. Critical Issues - The ability of HMOX1 to be induced by a variety of stressors, in an equally wide variety of tissues and cell types, represents an obstacle for the therapeutic exploitation of the enzyme. Any capacity to modulate HMOX1 in cardiovascular and metabolic diseases must be tempered with an appreciation that HMOX1 may impact on cancer. Moreover, the potential for heme catabolism end products, such a carbon monoxide, to amplify the HMOX1 stress response must be considered. Future Directions - A more complete understanding of HMOX1 modifications and the properties that they impart is necessary. Delineating these parameters will provide a clearer picture of the opportunities to modulate HMOX1 in human disease.Antioxidants & Redox Signaling 11/2013; · 8.20 Impact Factor
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ABSTRACT: OBJECTIVE: NF-E2-related factor 2 (Nrf2) is a transcription factor that is related to tumor cell multidrug resistance and proliferation. Here we studied the involvement of Nrf2 in the migration and invasion of human U251 glioma cells. METHODS: Two kinds of plasmid, that is, pEGFP-Nrf2 and Si-Nrf2, were constructed and transfected to upregulate or downregulate the expression of Nrf2 in U251 glioma cell line. Blank vectors or random siRNA plasmid were used as negative control. Cells treated with lipofectamine only were set up as blank control. Protein and mRNA level of Nrf2 and matrix metalloproteinase 9 (MMP9) were investigated by reverse transcriptase-polymerase chain reaction and western blot after transfection. Wound healing assay and transwell assay were used to study migration and invasion of U251 after transfection. Gelatin zymography was performed to reveal the change of MMP9 activity after transfection. RESULTS: The mRNA and protein level of Nrf2 was upregulated in U251-pEGFP-Nrf2 while downregulated in U251-Si-Nrf2 48 hours after transfection. In the wound healing assay, there were more cells in group pEGFP-Nrf2 crossing the scratch line than in group Si-Nrf2. Furthermore, in transwell migration and invasion assay, there were more cells in group pEGFP-Nrf2 penetrating the membranes than in group Si-Nrf2. Then we investigated the change of MMP9 activity, mRNA, and protein levels after transfection. The results suggested that upregulation of Nrf2 led to an increase in MMP9 expression and activity whereas downregulation of Nrf2 led to a decrease in MMP9 expression and activity. CONCLUSION: Nrf2 is involved in migration and invasion of U251 cells, which may be related to MMP9.World Neurosurgery 11/2011; · 1.77 Impact Factor
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ABSTRACT: Anti-oxidant capacity is crucial defence against environmental or endogenous oxidative stress. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that plays a key defensive role against oxidative and cytotoxic stress and cellular senescence. However, Nrf2 signalling is impaired in several aging-related diseases, such as chronic pulmonary obstructive disease (COPD), cancer, and neurodegenerative diseases. Thus, novel therapeutics that enhance Nrf2 signalling are an attractive approach to treat these diseases. Nrf2 was stabilized by SKI-II (2-(p-hydroxyanilino)-4-(p-chlorophenyl) thiazole), which is a known sphingosine kinase inhibitor, in human bronchial epithelial cell line, BEAS2B, and in primary human bronchial epithelial cells, leading to enhancement of anti-oxidant proteins, such as HO-1, NQO1 and GCLM. The activation of Nrf2 was achieved by the generation of inactive dimerized form of Keap1, a negative regulator of Nrf2 expression, which was independent of sphingosine kinase inhibition. Using mice that were exposed to cigarette smoke, SKI-II induced Nrf2 expression together with HO-1 in their lungs. In addition, SKI-II reduced cigarette smoke mediated oxidative stress, macrophages and neutrophil infiltration and markers of inflammation in mice. SKI-II appears to be a novel activator of Nrf2 signalling via the inactivation of Keap1.PLoS ONE 02/2014; 9(2):e88168. · 3.53 Impact Factor