Abstract 15037: Novel Role of Kelch-like ECH-associated Protein 1/NF-E2-related Factor 2 System in Vascular Smooth Muscle Cell Apoptosis Following Vascular Injury

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Takashi Ashino ◽  
Masayuki Yamamoto ◽  
Satoshi Numazawa
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Vascular Injury ◽  
Neointimal Hyperplasia ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Neointimal Formation ◽  
Quinone Oxidoreductase

Abnormal increases in vascular smooth muscle cells (VSMCs) in the intimal region after vascular injury are a key event in the neointimal hyperplasia followed by vascular occlusive diseases. To maintain vascular functions, the number of VSMCs is tightly controlled by those proliferation and apoptosis during vascular remodeling. Kelch-like ECH-associated protein 1 (Keap1)-NF-E2-related factor 2 (Nrf2) system plays a critical role in the oxidative stress response. While Keap1 ubiquitinates Nrf2 for degradation under unstressed conditions, this Keap1 function is abrogated in response to oxidative stress, leading to Nrf2 stabilization and coordinated up-regulation of antioxidant genes. We have previously found that Nrf2 plays an important role in neointimal hyperplasia after vascular injury via regulating platelet-derived growth factor-induced reactive oxygen species-dependent VSMC migration; however, the role of Keap1-Nrf2 system in VSMC apoptosis has not been established. Here we show that TUNEL-positive cells are detected in both the layers of neointima and media, both of which observe alpha-smooth muscle actin positive and high Nrf2-expressed cells, 14 days after transluminal arterial injury in mice. Nrf2 deficient mice show decreased TUNEL-positive cells in neointimal and medial areas (60%) and enhanced neointimal formation (I/M ratio: 152%) 14 days after vascular injury compared with the wild-type mice. In VSMCs isolated from the thoracic aorta of rats, depletion of Keap1 with siRNA increases nuclear Nrf2 (685%) and induces its target genes, including NAD(P)H: quinone oxidoreductase-1 (664%) and heme oxygenase-1 (230%). Functionally, Keap1 depletion increase apoptotic morphological features such as cell shrinkage and nuclear condensation (4114%), annexin V binding (512%), and positive TUNEL staining in VSMCs, which is associated with caspase-3/7 activation (576%). Pretransfection of VSMCs with Nrf2 siRNA inhibits apotosis mediated by Keap1 siRNA. In summary, Keap1-Nrf2 system regulates VSMC apoptosis in the process of neointimal formation, thereby inhibiting VSMC hyperproliferation, which may contribute to the development of neointimal hyperplasia after vascular injury.

Stress-induced senescence exaggerates postinjury neointimal formation in the old vasculature

2010 ◽  
Vol 298 (1) ◽  
pp. H66-H74 ◽  
Author(s):  
Sheik J. Khan ◽  
Si Pham ◽  
Yunteo Wei ◽  
Dania Mateo ◽  
Melissa St-Pierre ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Vascular Injury ◽  
Vascular Wall ◽  
Galactosidase Activity ◽  
Neointimal Formation ◽  
Normal Cells ◽  
The Media ◽  
Vascular Senescence

This study aims to demonstrate the role of stress-induced senescence in aged-related neointimal formation. We demonstrated that aging increases senescence-associated β-galactosidase activity (SA-β-Gal) after vascular injury and the subsequent neointimal formation (neointima-to-media ratio: 0.8 ± 0.2 vs. 0.54 ± 0.15) in rats. We found that senescent cells (SA-β-Gal+ p21+) were scattered throughout the media and adventitia of the vascular wall at day 7 after injury and reached their maximum number at day 14. However, senescent cells only persisted in the injured arteries of aged animals until day 30. No senescent cells were observed in the noninjured, contralateral artery. Interestingly, vascular senescent cells accumulated genomic 8-oxo-7,8-dihydrodeoxyguanine, indicating that these cells were under intense oxidative stress. To demonstrate whether senescence worsens intimal hyperplasia after injury, we seeded matrigel-embedded senescent and nonsenescent vascular smooth muscle cells around injured vessels. The neointima was thicker in arteries treated with senescent cells with respect to those that received normal cells (neointima-to-media ratio: 0.41 ± 0.105 vs. 0.26 ± 0.04). In conclusion, these results demonstrate that vascular senescence is not only a consequence of postinjury oxidative stress but is also a worsening factor for neointimal development in the aging vasculature.

scholarly journals S-Allyl Cysteine Alleviates Hydrogen Peroxide Induced Oxidative Injury and Apoptosis through Upregulation of Akt/Nrf-2/HO-1 Signaling Pathway in HepG2 Cells

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Chitra Basu ◽  
Runa Sur
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Oxidative Damage ◽  
Hepg2 Cells ◽  
Liver Diseases ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Dependent Manner ◽  
Cell Viability Assay

Hydrogen peroxide (H2O2) mediated oxidative stress leading to hepatocyte apoptosis plays a pivotal role in the pathophysiology of several chronic liver diseases. This study demonstrates that S-allyl cysteine (SAC) renders cytoprotective effects on H2O2 induced oxidative damage and apoptosis in HepG2 cells. Cell viability assay showed that SAC protected HepG2 cells from H2O2 induced cytotoxicity. Further, SAC treatment dose dependently inhibited H2O2 induced apoptosis via decreasing the Bax/Bcl-2 ratio, restoring mitochondrial membrane potential (∆Ψm), inhibiting mitochondrial cytochrome c release, and inhibiting proteolytic cleavage of caspase-3. SAC protected cells from H2O2 induced oxidative damage by inhibiting reactive oxygen species accumulation and lipid peroxidation. The mechanism underlying the antiapoptotic and antioxidative role of SAC is the induction of the heme oxygenase-1 (HO-1) gene in an NF-E2-related factor-2 (Nrf-2) and Akt dependent manner. Specifically SAC was found to induce the phosphorylation of Akt and enhance the nuclear localization of Nrf-2 in cells. Our results were further confirmed by specific HO-1 gene knockdown studies which clearly demonstrated that HO-1 induction indeed played a key role in SAC mediated inhibition of apoptosis and ROS production in HepG2 cells, thus suggesting a hepatoprotective role of SAC in combating oxidative stress mediated liver diseases.

scholarly journals Cinnamaldehyde Ameliorates Vascular Dysfunction in Diabetic Mice by Activating Nrf2

2020 ◽  
Vol 33 (7) ◽  
pp. 610-619 ◽  
Author(s):  
Peijian Wang ◽  
Yi Yang ◽  
Dan Wang ◽  
Qiyuan Yang ◽  
Jindong Wan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Vascular Dysfunction ◽  
Mesenteric Arteries ◽  
Heme Oxygenase 1 ◽  
No Production ◽  
Related Factor ◽  
Diabetic Mice ◽  
Quinone Oxidoreductase ◽  
Nrf2 Signaling Pathway

Abstract BACKGROUND Oxidative stress is known to be associated with the development of diabetes. Cinnamaldehyde (CA) is a spice compound in cinnamon that enhances the antioxidant defense against reactive oxygen species (ROS) by activating nuclear factor erythroid-related factor 2 (Nrf2), which has been shown to have a cardioprotection effect. However, the relationship between CA and Nrf2 in diabetic vascular complications remains unclear. METHODS Leptin receptor-deficient (db/db) mice were fed normal chow or diet containing 0.02% CA for 12 weeks. The vascular tone, blood pressure, superoxide level, nitric oxide (NO) production, renal morphology, and function were measured in each group. RESULTS CA remarkably inhibited ROS generation, preserved NO production, increased phosphorylated endothelial nitric oxide synthase (p-eNOS), attenuated the upregulation of nitrotyrosine, P22 and P47 in aortas of db/db mice, and apparently ameliorated the elevation of type IV collagen, TGF-β1, P22, and P47 in kidney of db/db mice. Feeding with CA improved endothelium-dependent relaxation of aortas and mesenteric arteries, and alleviated the remodeling of mesenteric arteries in db/db mice. Additionally, dietary CA ameliorated glomerular fibrosis and renal dysfunction in diabetic mice. Nrf2 and its targeted genes heme oxygenase-1 (HO-1) and quinone oxidoreductase-1 (NQO-1) were slightly increased in db/db mice and further upregulated by CA. However, these protective effects of CA were reversed in Nrf2 downregulation mice. CONCLUSIONS A prolonged diet of CA protects against diabetic vascular dysfunction by inhibiting oxidative stress through activating of Nrf2 signaling pathway in db/db mice.

The pro-oxidant role of methylglyoxal in mesenteric artery smooth muscle cells

2005 ◽  
Vol 83 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Lingyun Wu
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Mesenteric Artery ◽  
Advanced Glycation Endproducts ◽  
Muscle Cells ◽  
Heme Oxygenase 1 ◽  
Rat Mesenteric Artery ◽  
Cultured Smooth Muscle Cells

Methylglyoxal (MG), a highly reactive metabolite of glucose, causes non-enzymatic glycation of proteins to form irreversible advanced glycation endproducts (AGEs). The present study investigated whether methylglyoxal induced oxidative stress and activated nuclear factor kappa B (NF-κB) in freshly isolated and cultured smooth muscle cells (SMCs) from rat mesenteric artery. The treatment of cells with MG (50 or 100 µmol/L) induced a significant increase in AGE formation and oxidation of DCF. MG-enhanced generation of AGEs and the oxidation of DCF was markedly inhibited by antioxidant n-acetylcysteine (NAC, 600 µmol/L). MG at a concentration of 100 µmol/L increased the heme-oxygenase-1 expression in these cells. Moreover, MG activated NF-κB p65, indicated by an increased im muno cytochemistry stain for NF-κB p65 located in the nucleus after the treatment of mesenteric artery SMCs with MG. MG-induced activation of NF-κB p65 was inhibited by NAC. In summary, MG significantly increases oxidative stress and activates NF-κB p65 in mesenteric artery SMCs. The pro-oxidant role of methylglyoxal may contribute to various pathological changes of SMCs from resistance arteries.Key words: methylglyoxal, oxidative stress, NF-κB p65, vascular smooth muscle cells, mesenteric artery.

scholarly journals Epigallocatechin Gallate Attenuates Proliferation and Oxidative Stress in Human Vascular Smooth Muscle Cells Induced by Interleukin-1βvia Heme Oxygenase-1

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Po-Len Liu ◽  
Jung-Tung Liu ◽  
Hsuan-Fu Kuo ◽  
Inn-Wen Chong ◽  
Chong-Chao Hsieh
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Green Tea ◽  
Vascular Smooth Muscle Cells ◽  
Heme Oxygenase ◽  
Muscle Cells ◽  
Heme Oxygenase 1 ◽  
And Oxidative Stress

Proliferation of vascular smooth muscle cells (VSMCs) triggered by inflammatory stimuli and oxidative stress contributes importantly to atherogenesis. The association of green tea consumption with cardiovascular protection has been well documented in epidemiological observations, however, the underlying mechanisms remain unclear. This study aimed to elucidate the effects of the most active green tea catechin derivative, (−)-epigallocatechin-3-gallate (EGCG), in human aortic smooth muscle cells (HASMCs), focusing particularly on the role of a potent anti-inflammatory and antioxidative enzyme heme oxygenase-1 (HO-1). We found that pretreatment of EGCG dose- and time-dependently induced HO-1 protein levels in HASMCs. EGCG inhibited interleukin- (IL-)1β-induced HASMC proliferation and oxidative stress in a dose-dependent manner. The HO-1 inducer CoPPIX decreased IL-1β-induced cell proliferation, whereas the HO-1 enzyme inhibitor ZnPPIX significantly reversed EGCG-caused growth inhibition in IL-1β-treated HASMCs. At the molecular level, EGCG treatment significantly activated nuclear factor erythroid-2-related factor (Nrf2) transcription activities. These results suggest that EGCG might serve as a complementary and alternative medicine in the treatment of these pathologies by inducing HO-1 expression and subsequently decreasing VSMC proliferation.

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