scholarly journals Inhibition of nuclear factor-erythroid 2–related factor (Nrf2) by caveolin-1 promotes stress-induced premature senescence

2013 ◽  
Vol 24 (12) ◽  
pp. 1852-1862 ◽  
Author(s):  
Daniela Volonte ◽  
Zhongmin Liu ◽  
Paul M. Musille ◽  
Elena Stoppani ◽  
Nobunao Wakabayashi ◽  
...  

Reactive oxygen species (ROS) can induce premature cellular senescence, which is believed to contribute to aging and age-related diseases. The nuclear erythroid 2 p45–related factor-2 (Nrf2) is a transcription factor that mediates cytoprotective responses against stress. We demonstrate that caveolin-1 is a direct binding partner of Nrf2, as shown by the binding of the scaffolding domain of caveolin-1 (amino acids 82–101) to the caveolin-binding domain of Nrf2 (amino acids 281–289). Biochemical studies show that Nrf2 is concentrated into caveolar membranes in human and mouse fibroblasts, where it colocalizes with caveolin-1, under resting conditions. After oxidative stress, caveolin-1 limits the movement of Nrf2 from caveolar membranes to the nucleus. In contrast, Nrf2 is constitutively localized to the nucleus before and after oxidative stress in caveolin-1–null mouse embryonic fibroblasts (MEFs), which do not express caveolin-1. Functional studies demonstrate that caveolin-1 acts as an endogenous inhibitor of Nrf2, as shown by the enhanced up-regulation of NQO1, an Nrf2 target gene, in caveolin-1–null MEFs and the activation or inhibition of a luciferase construct carrying an antioxidant responsive element (ARE) after down-regulation of caveolin-1 by small interfering RNA or overexpression of caveolin-1, respectively. Expression of a mutant form of Nrf2 that cannot bind to caveolin-1 (Φ→A-Nrf2) hyperactivates ARE and inhibits oxidative stress–induced activation of the p53/p21Waf1/Cip1 pathway and induction of premature senescence in fibroblasts. Finally, we show that overexpression of caveolin-1 in colon cancer cells inhibits oxidant-induced activation of Nrf2-dependent signaling, promotes premature senescence, and inhibits their transformed phenotype. Thus, by inhibiting Nrf2-mediated signaling, caveolin-1 links free radicals to the activation of the p53/senescence pathway.

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 25
Author(s):  
Lara Macchioni ◽  
Davide Chiasserini ◽  
Letizia Mezzasoma ◽  
Magdalena Davidescu ◽  
Pier Luigi Orvietani ◽  
...  

Age-related retinal degenerations, including age-related macular degeneration (AMD), are caused by the loss of retinal pigmented epithelial (RPE) cells and photoreceptors. The pathogenesis of AMD, deeply linked to the aging process, also involves oxidative stress and inflammatory responses. However, the molecular mechanisms contributing to the shift from healthy aging to AMD are still poorly understood. Since RPE cells in the retina are chronically exposed to a pro-oxidant microenvironment throughout life, we simulated in vivo conditions by growing ARPE-19 cells in the presence of 10 μM H2O2 for several passages. This long-term oxidative insult induced senescence in ARPE-19 cells without affecting cell proliferation. Global proteomic analysis revealed a dysregulated expression in proteins involved in antioxidant response, mitochondrial homeostasis, and extracellular matrix organization. The analyses of mitochondrial functionality showed increased mitochondrial biogenesis and ATP generation and improved response to oxidative stress. The latter, however, was linked to nuclear factor-κB (NF-κB) rather than nuclear factor erythroid 2–related factor 2 (Nrf2) activation. NF-κB hyperactivation also resulted in increased pro-inflammatory cytokines expression and inflammasome activation. Moreover, in response to additional pro-inflammatory insults, senescent ARPE-19 cells underwent an exaggerated inflammatory reaction. Our results indicate senescence as an important link between chronic oxidative insult and detrimental chronic inflammation, with possible future repercussions for therapeutic interventions.


Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 622
Author(s):  
Iswariyaraja Sridevi Gurubaran ◽  
Hanna Heloterä ◽  
Stephen Marry ◽  
Ali Koskela ◽  
Juha M. T. Hyttinen ◽  
...  

Aging-associated chronic oxidative stress and inflammation are known to be involved in various diseases, e.g., age-related macular degeneration (AMD). Previously, we reported the presence of dry AMD-like signs, such as elevated oxidative stress, dysfunctional mitophagy and the accumulation of detrimental oxidized materials in the retinal pigment epithelial (RPE) cells of nuclear factor erythroid 2-related factor 2, and a peroxisome proliferator-activated receptor gamma coactivator 1-alpha (NFE2L2/PGC1α) double knockout (dKO) mouse model. Here, we investigated the dynamics of inflammatory markers in one-year-old NFE2L2/PGC1α dKO mice. Immunohistochemical analysis revealed an increase in levels of Toll-like receptors 3 and 9, while those of NOD-like receptor 3 were decreased in NFE2L2/PGC1α dKO retinal specimens as compared to wild type animals. Further analysis showed a trend towards an increase in complement component C5a independent of component C3, observed to be tightly regulated by complement factor H. Interestingly, we found that thrombin, a serine protease enzyme, was involved in enhancing the terminal pathway producing C5a, independent of C3. We also detected an increase in primary acute phase C-reactive protein and receptor for advanced glycation end products in NFE2L2/PGC1α dKO retina. Our main data show C5 and thrombin upregulation together with decreased C3 levels in this dry AMD-like model. In general, the retina strives to mount an orchestrated inflammatory response while attempting to maintain tissue homeostasis and resolve inflammation.


2021 ◽  
Vol 14 (8) ◽  
pp. 1260-1273
Author(s):  
Zi-Yan Cai ◽  
◽  
Ke Liu ◽  
Xuan-Chu Duan ◽  
◽  
...  

Age-related eye diseases, including cataract, glaucoma, diabetic retinopathy (DR), and age-related macular degeneration (AMD), are the leading causes of vision loss in the world. Several studies have shown that the occurrence and development of these diseases have an important relationship with oxidative stress in the eye. The Keap1-Nrf2-ARE pathway is a classical pathway that resists oxidative stress and inflammation in the body. This pathway is also active in the development of age-related eye diseases. A variety of drugs have been shown to treat age-related eye diseases through the Keap1-Nrf2-ARE (Kelch-like ECH-Associating protein 1- nuclear factor erythroid 2 related factor 2-antioxidant response element) pathway. This review describes the role of oxidative stress in the development of age-related eye diseases, the function and regulation of the Keap1-Nrf2-ARE pathway, and the therapeutic effects of drugs associated with this pathway on age-related eye diseases.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yasuhiro Nakagami

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that binds to antioxidant response elements located in the promoter region of genes encoding many antioxidant enzymes and phase II detoxifying enzymes. Activation of Nrf2 functions is one of the critical defensive mechanisms against oxidative stress in many species. The retina is constantly exposed to reactive oxygen species, and oxidative stress is a major contributor to age-related macular diseases. Moreover, the resulting inflammation and neuronal degeneration are also related to other retinal diseases. The well-known Nrf2 activators, bardoxolone methyl and its derivatives, have been the subject of a number of clinical trials, including those aimed at treating chronic kidney disease, pulmonary arterial hypertension, and mitochondrial myopathies. Recent studies suggest that Nrf2 activation protects the retina from retinal diseases. In particular, this is supported by the finding that Nrf2 knockout mice display age-related retinal degeneration. Moreover, the concept has been validated by the efficacy of Nrf2 activators in a number of retinal pathological models. We have also recently succeeded in generating a novel Nrf2 activator, RS9, using a biotransformation technique. This review discusses current links between retinal diseases and Nrf2 and the possibility of treating retinal diseases by activating the Nrf2 signaling pathway.


Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 114 ◽  
Author(s):  
Ji Hye Yang ◽  
Moon-Hee Choi ◽  
Chang-Su Na ◽  
Sam Seok Cho ◽  
Jae Hoon Kim ◽  
...  

This study was designed to investigate the hepatoprotective effect of bamboo stems using in vitro and in vivo experimental liver damage models. Ethyl acetate fraction of 80% ethanol extract of Phyllostachys nigra stem (PN3) containing polyphenols had a higher NQO1-ARE reporter gene activity as monitored by the activity of the NF-E2-related factor (Nrf2) antioxidant pathway in cells in comparison to extracts from other species and under other conditions. The Nrf2 was translocated from the cytosol to the nucleus in response to PN3, followed by induction of the Nrf2 target gene expression, including HO-1, GCL, and NQO-1 in HepG2 cells. Phosphorylation of Nrf2 in HepG2 cells was enhanced in PN3, which was mediated by PKCδ, ERK, and p38 MAPK. Consequently, PN3 inhibited arachidonic acid (AA) + iron-induced reactive oxygen species generation and glutathione depletion, and, thus, highlighted their role in cytotoxicity. Treatment with major polyphenols of PN3, including catechin, chlorogenic acid, caffeic acid, and p-coumaric acid, also improved AA + iron-mediated oxidative stress and, thus, improved cell viability. Treatment with phenylhydrazine in mice, i.e., the iron overload liver injury model, increased plasma alanine aminotransferase and aspartate aminotransferase levels and changed histological features in mice—a response that was almost completely blocked by PN3 administration. Moreover, PN3 extract mitigated phenylhydrazine-induced oxidative stress and inflammatory responses. Conclusively, PN3 can exert a hepatoprotective effect against iron overload-induced acute liver damage due to its antioxidant properties.


2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Samuel Abokyi ◽  
Chi-Ho To ◽  
Tim T. Lam ◽  
Dennis Y. Tse

Age-related macular degeneration (AMD) is a common cause of visual impairment in the elderly. There are very limited therapeutic options for AMD with the predominant therapies targeting vascular endothelial growth factor (VEGF) in the retina of patients afflicted with wet AMD. Hence, it is important to remind readers, especially those interested in AMD, about current studies that may help to develop novel therapies for other stages of AMD. This study, therefore, provides a comprehensive review of studies on human specimens as well as rodent models of the disease, to identify and analyze the molecular mechanisms behind AMD development and progression. The evaluation of this information highlights the central role that oxidative damage in the retina plays in contributing to major pathways, including inflammation and angiogenesis, found in the AMD phenotype. Following on the debate of oxidative stress as the earliest injury in the AMD pathogenesis, we demonstrated how the targeting of oxidative stress-associated pathways, such as autophagy and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, might be the futuristic direction to explore in the search of an effective treatment for AMD, as the dysregulation of these mechanisms is crucial to oxidative injury in the retina. In addition, animal models of AMD have been discussed in great detail, with their strengths and pitfalls included, to assist inform in the selection of suitable models for investigating any of the molecular mechanisms.


2019 ◽  
Vol 20 (13) ◽  
pp. 3208 ◽  
Author(s):  
Fabiane Valentini Francisqueti-Ferron ◽  
Artur Junio Togneri Ferron ◽  
Jéssica Leite Garcia ◽  
Carol Cristina Vágula de Almeida Silva ◽  
Mariane Róvero Costa ◽  
...  

The transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) is one of the most important oxidative stress regulator in the human body. Once Nrf2 regulates the expression of a large number of cytoprotective genes, it plays a crucial role in the prevention of several diseases, including age-related disorders. However, the involvement of Nrf2 on these conditions is complex and needs to be clarified. Here, a brief compilation of the Nrf2 enrollment in the pathophysiology of the most common age-related diseases and bring insights for future research on the Nrf2 pathway is described. This review shows a controversial response of this transcriptional factor on the presented diseases. This reinforces the necessity of more studies to investigate modulation strategies for Nrf2, making it a possible therapeutic target in the treatment of age-related disorders.


2015 ◽  
Vol 2015 ◽  
pp. 1-24 ◽  
Author(s):  
Mika Reinisalo ◽  
Anna Kårlund ◽  
Ali Koskela ◽  
Kai Kaarniranta ◽  
Reijo O. Karjalainen

Numerous studies have highlighted the key roles of oxidative stress and inflammation in aging-related diseases such as obesity, type 2 diabetes, age-related macular degeneration (AMD), and Alzheimer’s disease (AD). In aging cells, the natural antioxidant capacity decreases and the overall efficiency of reparative systems against cell damage becomes impaired. There is convincing data that stilbene compounds, a diverse group of natural defence phenolics, abundant in grapes, berries, and conifer bark waste, may confer a protective effect against aging-related diseases. This review highlights recent data helping to clarify the molecular mechanisms involved in the stilbene-mediated protection against oxidative stress. The impact of stilbenes on the nuclear factor-erythroid-2-related factor-2 (Nrf2) mediated cellular defence against oxidative stress as well as the potential roles of SQSTM1/p62 protein in Nrf2/Keap1 signaling and autophagy will be summarized. The therapeutic potential of stilbene compounds against the most common aging-related diseases is discussed.


2017 ◽  
Vol 28 (9) ◽  
pp. 1177-1185 ◽  
Author(s):  
Glenn Marsboom ◽  
Zhenlong Chen ◽  
Yang Yuan ◽  
Yanmin Zhang ◽  
Chinnaswamy Tiruppathi ◽  
...  

A heterozygous caveolin-1 c.474delA mutation has been identified in a family with heritable pulmonary arterial hypertension (PAH). This frameshift mutation leads to a caveolin-1 protein that contains all known functional domains but has a change in only the final 20 amino acids of the C-terminus. Here we studied how this mutation alters caveolin-1 function, using patient-derived fibroblasts. Transmission electron microscopy showed that fibroblasts carrying the c.474delA mutation form typical caveolae. Expression of mutated caveolin-1 in caveolin-1–null mouse fibroblasts failed to induce formation of caveolae due to retention of the mutated protein in the endoplasmic reticulum. However, coexpression of wild-type caveolin-1 with mutated caveolin-1 restored the ability to form caveolae. Importantly, fibroblasts carrying the mutation showed twofold increase in proliferation rate associated with hyperphosphorylation of Smad1/5/8. This mutation impaired the antiproliferative function of caveolin-1. Inhibition of type I TGFβ receptors ALK1/2/3/6 responsible for phosphorylation of Smad1/5/8 reduced the hyperproliferation seen in c.474delA fibroblasts. These results demonstrate the critical role of the final 20 amino acids of caveolin-1 in modulating fibroblast proliferation by dampening Smad signaling and suggest that augmented Smad signaling and fibroblast hyperproliferation are contributing factors in the pathogenesis of PAH in patients with caveolin-1 c.474delA mutation.


2019 ◽  
Author(s):  
Yan Wang ◽  
Meiling Lian ◽  
Jing Zhou ◽  
Shengzhou Wu

AbstractThe pathogenesis of Alzheimer’s disease (AD) involves the central roles of oxidative stress. Oxidative stress due to Dicer1 depletion may underline the neurodegeneration in the central nervous system and degeneration of retinal pigment epithelial cells in geographic atrophy form of age-related macular degeneration. We hypothesized that Dicer1 may play roles in AD pathogenesis. Indeed, Dicer1 was reduced in the hippocampus and cortex of APPswe/PSEN1dE9 mice, an AD model. Dicer1 knockdown induced oxidative stress, mitochondrial dysfunction, apoptosis in cultured neurons, and increased secretions of interleukin-1β/-18, indicators of inflammasome activation. Accordingly, Dicer1 was decreased by amyloid peptide and the effect was connected with down-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2). Anti-oxidant response elements (AREs) were identified in the promoter of Dicer1 and Keap1-Nrf2-AREs signaling was demonstrated to regulate Dicer1 expression. Furthermore, overexpression of Dicer1 carried by adenovirus in the cultured neurons rescued neurite deficit induced by amyloid peptide. In consistent with the in vitro results, injection of Dicer1-overexperssion adenovirus in the hippocampus of the AD mice significantly improved spatial learning. Altogether, we unveiled an unexploited roles of Dicer1 in AD and a novel way of Dicer1 regulation. These findings suggest that Dicer1 may be a target in AD therapy.Significance StatementDicer1 is a microRNA-processing enzyme, which is central to microRNA maturation. For the first time, we herein reported that Dicer1 was reduced in the hippocampus or the cortex of AD mice before overt amyloid plque deposition and overexpression of Dicer1 in the hippocampus significantly improved spatial learning in AD mice. We also demonstrated that Dicer1 was regulated by Keap1-Nrf2-ARE signaling which is unreported before. These findings advance understandings of AD pathogenesis and suggest that Dicer1 may be a molecular target in AD therapy.


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