scholarly journals The antioxidant response favors Leishmania parasites survival, limits inflammation and reprograms the host cell metabolism

2021 ◽  
Vol 17 (3) ◽  
pp. e1009422
Author(s):  
Marta Reverte ◽  
Remzi Onur Eren ◽  
Baijayanti Jha ◽  
Chantal Desponds ◽  
Tiia Snäkä ◽  
...  

The oxidative burst generated by the host immune system can restrict intracellular parasite entry and growth. While this burst leads to the induction of antioxidative enzymes, the molecular mechanisms and the consequences of this counter-response on the life of intracellular human parasites are largely unknown. The transcription factor NF-E2-related factor (NRF2) could be a key mediator of antioxidant signaling during infection due to the entry of parasites. Here, we showed that NRF2 was strongly upregulated in infection with the human Leishmania protozoan parasites, its activation was dependent on a NADPH oxidase 2 (NOX2) and SRC family of protein tyrosine kinases (SFKs) signaling pathway and it reprogrammed host cell metabolism. In inflammatory leishmaniasis caused by a viral endosymbiont inducing TNF-α in chronic leishmaniasis, NRF2 activation promoted parasite persistence but limited TNF-α production and tissue destruction. These data provided evidence of the dual role of NRF2 in protecting both the invading pathogen from reactive oxygen species and the host from an excess of the TNF-α destructive pro-inflammatory cytokine.

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 709
Author(s):  
Ana E. Cartaya ◽  
Halle Lutz ◽  
Sophie Maiocchi ◽  
Morgan Nalesnik ◽  
Edward M. Bahnson

Selective delivery of nuclear factor erythroid 2-related factor 2 (Nrf2) activators to the injured vasculature at the time of vascular surgical intervention has the potential to attenuate oxidative stress and decrease vascular smooth muscle cell (VSMC) hyperproliferation and migration towards the inner vessel wall. To this end, we developed a nanoformulation of cinnamic aldehyde (CA), termed Antioxidant Response Activating nanoParticles (ARAPas), that can be readily loaded into macrophages ex vivo. The CA-ARAPas-macrophage system was used to study the effects of CA on VSMC in culture. CA was encapsulated into a pluronic micelle that was readily loaded into both murine and human macrophages. CA-ARAPas inhibits VSMC proliferation and migration, and activates Nrf2. Macrophage-mediated transfer of CA-ARAPas to VSMC is evident after 12 h, and Nrf2 activation is apparent after 24 h. This is the first report, to the best of our knowledge, of CA encapsulation in pluronic micelles for macrophage-mediated delivery studies. The results of this study highlight the feasibility of CA encapsulation and subsequent macrophage uptake for delivery of cargo into other pertinent cells, such as VSMC.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Zi-Huan Zhang ◽  
Jia-Qiang Liu ◽  
Cheng-Di Hu ◽  
Xin-Tong Zhao ◽  
Fei-Yun Qin ◽  
...  

Luteolin (LUT) possesses multiple biologic functions and has beneficial effects for cardiovascular and cerebral vascular diseases. Here, we investigated the protective effects of LUT against subarachnoid hemorrhage (SAH) and the involvement of underlying molecular mechanisms. In a rat model of SAH, LUT significantly inhibited SAH-induced neuroinflammation as evidenced by reduced microglia activation, decreased neutrophil infiltration, and suppressed proinflammatory cytokine release. In addition, LUT markedly ameliorated SAH-induced oxidative damage and restored the endogenous antioxidant systems. Concomitant with the suppressed oxidative stress and neuroinflammation, LUT significantly improved neurologic function and reduced neuronal cell death after SAH. Mechanistically, LUT treatment significantly enhanced the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), while it downregulated nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation. Inhibition of Nrf2 by ML385 dramatically abrogated LUT-induced Nrf2 activation and NLRP3 suppression and reversed the beneficial effects of LUT against SAH. In neurons and microglia coculture system, LUT also mitigated oxidative stress, inflammatory response, and neuronal degeneration. These beneficial effects were associated with activation of the Nrf2 and inhibitory effects on NLRP3 inflammasome and were reversed by ML385 treatment. Taken together, this present study reveals that LUT confers protection against SAH by inhibiting NLRP3 inflammasome signaling pathway, which may be modulated by Nrf2 activation.


2020 ◽  
Vol 41 (4) ◽  
pp. 405-416 ◽  
Author(s):  
Feng He ◽  
Laura Antonucci ◽  
Michael Karin

Abstract Nuclear factor erythroid 2-related factor 2 (NRF2) is a master transcriptional regulator of genes whose products defend our cells for toxic and oxidative insults. Although NRF2 activation may reduce cancer risk by suppressing oxidative stress and tumor-promoting inflammation, many cancers exhibit elevated NRF2 activity either due to mutations that disrupt the negative control of NRF2 activity or other factors. Importantly, NRF2 activation is associated with poor prognosis and NRF2 has turned out to be a key activator of cancer-supportive anabolic metabolism. In this review, we summarize the diverse roles played by NRF2 in cancer focusing on metabolic reprogramming and tumor-promoting inflammation.


2013 ◽  
Vol 64 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Huangyuan Li ◽  
Siying Wu ◽  
Junnian Chen ◽  
Bo Wang ◽  
Nian Shi

Transcription factor NF-E2-related factor 2 (Nrf2) is important for cell protection against chemical-induced oxidative stress. Previously, we have reported that in PC12 cells, Nrf2 can be triggered by deltamethrin (DM), a commonly used pyrethroid insecticide. Molecular mechanisms behind Nrf2 activation by DM are still unclear. Here we studied the effects of cell glutathione (GSH) depletion on Nrf2 activation by DM. We found that DM enhanced Nrf2 expression at the mRNA and protein levels and increased nuclear Nrf2 levels. Activation of Nrf2 was associated with activation of its downstream targets, such as heme oxygenase-1 (HO-1) and glutamate cysteine ligase catalytic subunit (GCLC). In contrast, DL-buthionine-[S,R]- sulfoximine (BSO), a known GSH-depleting agent, did not increase Nrf2 protein expression or cause its nuclear accumulation. However, pre-treatment with BSO triggered mRNA expression of HO-1 and GCLC. Furthermore, BSO pre-treatment suppressed DM-induced Nrf2 upregulation and activation and lowered mRNA expression of HO-1 and GCLC upon DM treatment. These data demonstrate that GSH depletion is not necessary for the activation of Nrf2/ARE by DM in PC12 cells, and that GCLC and HO-1 expression can increase through other signalling pathways.


2020 ◽  
Vol 21 (15) ◽  
pp. 5378 ◽  
Author(s):  
Effi Haque ◽  
M. Rezaul Karim ◽  
Aamir Salam Teeli ◽  
Magdalena Śmiech ◽  
Paweł Leszczynski ◽  
...  

NF-E2-related factor 2 (NRF2) is a basic leucine zipper transcription factor, a master regulator of redox homeostasis regulating a variety of genes for antioxidant and detoxification enzymes. NRF2 was, therefore, initially thought to protect the liver from oxidative stress. Recent studies, however, have revealed that mutations in NRF2 cause aberrant accumulation of NRF2 in the nucleus and exert the upregulation of NRF2 target genes. Moreover, among all molecular changes in hepatocellular carcinoma (HCC), NRF2 activation has been revealed as a more prominent pathway contributing to the progression of precancerous lesions to malignancy. Nevertheless, how its activation leads to poor prognosis in HCC patients remains unclear. In this review, we provide an overview of how aberrant activation of NRF2 triggers HCC development. We also summarize the emerging roles of other NRF family members in liver cancer development.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Yi Zou ◽  
Jun Wang ◽  
Jian Peng ◽  
Hongkui Wei

Oregano essential oil (OEO) has long been used to improve the health of animals, particularly their intestinal health. The health benefits of OEO are generally attributed to antioxidative actions, but the mechanisms remain unclear. Here, we investigate the antioxidative effects of OEO and their underlying molecular mechanisms in porcine small intestinal epithelial (IPEC-J2) cells. We found that OEO treatment prior to hydrogen peroxide (H2O2) exposure increased cell viability and prevented lactate dehydrogenase (LDH) release into the medium. H2O2-induced reactive oxygen species (ROS) and malondialdehyde (MDA) were remarkably suppressed by OEO. OEO dose-dependently increased mRNA and protein levels of the nuclear factor-erythroid 2-related factor-2 (Nrf2) target genes Cu/Zn-superoxide dismutase (SOD1) and g-glutamylcysteine ligase (GCLC, GLCM), as well as intracellular concentrations of SOD1 and glutathione. OEO also increased intranuclear expression of Nrf2 and the activity of an antioxidant response element reporter plasmid in IPEC-J2 cells. The OEO-induced expression of Nrf2-regulated genes and increased SOD1 and glutathione concentrations in IPEC-J2 cells were reduced by Nrf2 small interfering (si) RNAs, counteracting the protective effects of OEO against oxidative stress in IPEC-J2 cells. Our results suggest that OEO protects against H2O2-induced IPEC-J2 cell damage by inducing Nrf2 and related antioxidant enzymes.


2019 ◽  
Vol 116 (25) ◽  
pp. 12516-12523 ◽  
Author(s):  
Gahee Bahn ◽  
Jong-Sung Park ◽  
Ui Jeong Yun ◽  
Yoon Jee Lee ◽  
Yuri Choi ◽  
...  

BACE1 is the rate-limiting enzyme for amyloid-β peptides (Aβ) generation, a key event in the pathogenesis of Alzheimer’s disease (AD). By an unknown mechanism, levels of BACE1 and a BACE1 mRNA-stabilizing antisense RNA (BACE1-AS) are elevated in the brains of AD patients, implicating that dysregulation of BACE1 expression plays an important role in AD pathogenesis. We found that nuclear factor erythroid-derived 2-related factor 2 (NRF2/NFE2L2) represses the expression of BACE1 and BACE1-AS through binding to antioxidant response elements (AREs) in their promoters of mouse and human. NRF2-mediated inhibition of BACE1 and BACE1-AS expression is independent of redox regulation. NRF2 activation decreases production of BACE1 and BACE1-AS transcripts and Aβ production and ameliorates cognitive deficits in animal models of AD. Depletion of NRF2 increases BACE1 and BACE1-AS expression and Aβ production and worsens cognitive deficits. Our findings suggest that activation of NRF2 can prevent a key early pathogenic process in AD.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Kazi N Islam ◽  
David J Polhemus ◽  
Erminia Donnarumma ◽  
Hiroyuki Otsuka ◽  
Shashi Bhushan ◽  
...  

Background: Cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST) are enzymatic sources of hydrogen sulfide (H2S). Functions of H2S are mediated by several targets including ion channels and signaling proteins. Nuclear factor-erythriod 2-related factor 2 (NRF2) is responsible for the expression of antioxidant response element (ARE)-regulated genes and is known to be upregulated by H2S. We examined the levels of H2S producing enzymes, H2S, and NRF2 activation status in skeletal muscle obtained from CLI patients. Methods: Gastrocnemius tissues were attained post amputation from human CLI and aged-matched control patients. Tissue H2S levels were measured using gas chromatography methods coupled with sulfur chemiluminescence. RT-qPCR, immunoblot, and electrophoretic mobility shift assay (EMSA) were used to analyze respective gene expression, protein levels, and DNA binding activity, respectively. Results: We found mRNA and protein levels of CSE, CBS, and 3-MST were significantly decreased in skeletal muscle of CLI (~2 fold, p < 0.05) patients as compared to control. H2S and sulfane sulfur levels were significantly decreased in skeletal muscle of CLI patients. We also observed significant reductions in NRF2 activation (2 fold, p < 0.05) as well as antioxidant proteins, such as CuZn-superoxide dismutase (2 fold, p < 0.05), catalase (2 fold, p < 0.05), and glutathione peroxidase (2 fold, p < 0.05) in skeletal muscle of CLI patients. Biomarkers of oxidative stress, such as malondialdehyde and protein carbonyl formation were significantly increased (2 fold, p < 0.05) in skeletal muscle of CLI patients as compared to age-matched controls. Conclusions: The data demonstrate that H2S bioavailability and NRF2 activation are both attenuated in CLI tissues concomitant with significantly increased oxidative stress. Reductions in the activity of H2S producing enzymes may contribute to the pathogenesis of CLI.


2016 ◽  
Vol 8 (334) ◽  
pp. 334ra51-334ra51 ◽  
Author(s):  
Hui Wang ◽  
Xiufei Liu ◽  
Min Long ◽  
Yi Huang ◽  
Linlin Zhang ◽  
...  

Cancer is a common comorbidity of diabetic patients; however, little is known about the effects that antidiabetic drugs have on tumors. We discovered that common classes of drugs used in type 2 diabetes mellitus, the hypoglycemic dipeptidyl peptidase–4 inhibitors (DPP-4i) saxagliptin and sitagliptin, as well as the antineuropathic α-lipoic acid (ALA), do not increase tumor incidence but increase the risk of metastasis of existing tumors. Specifically, these drugs induce prolonged activation of the nuclear factor E2–related factor 2 (NRF2)–mediated antioxidant response through inhibition of KEAP1-C151–dependent ubiquitination and subsequent degradation of NRF2, resulting in up-regulated expression of metastasis-associated proteins, increased cancer cell migration, and promotion of metastasis in xenograft mouse models. Accordingly, knockdown ofNRF2attenuated naturally occurring and DPP-4i–induced tumor metastasis, whereas NRF2 activation accelerated metastasis. Furthermore, in human liver cancer tissue samples, increased NRF2 expression correlated with metastasis. Our findings suggest that antioxidants that activate NRF2 signaling may need to be administered with caution in cancer patients, such as diabetic patients with cancer. Moreover, NRF2 may be a potential biomarker and therapeutic target for tumor metastasis.


2014 ◽  
Vol 4 (12) ◽  
pp. 510 ◽  
Author(s):  
Rame Taha ◽  
Gilbert Blaise

Background: Chronic inflammation integrally related to oxidative stress has been increasingly recognized as a contributing factor in various chronic diseases such as neurodegenerative diseases, pulmonary diseases, metabolic syndrome, and cardiovascular diseases as well as premature aging. Thus, inhibiting this vicious circle has the potential to delay, prevent progression, and treat those diseases. However, adverse effects of current anti-inflammatory drugs and the failure of exogenous antioxidant encourage scientists to develop new therapeutic alternatives. The nuclear factor E2-related factor 2 (Nrf2) is the transcription factor that is responsible for the expression of antioxidant response element (ARE)-regulated genes and have been described as having many therapeutic effects. In this review, we have discussed the role of oxidative stress in various chronic diseases. Furthermore, we have also explored various novel ways to activate Nrf2 either directly or indirectly, which may have therapeutic potential in attenuating oxidative stress, inflammation and mitochondrial dysfunction that contributes to chronic diseases.Keywords: Oxidative stress, Mitochondria, Inflammation, Nrf2, Nutrition, Chronic diseases


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