Zinc ameliorates acrylamide-induced oxidative stress and apoptosis in testicular cells via Nrf2/HO-1/NfkB and Bax/Bcl2 signaling pathway.

BACKGROUND: Acrylamide is a toxic substance formed in some foods that require high-temperature cooking processes and has been implicated as a gonadotoxic agent. Zinc, on the other hand, is a known antioxidant with fertility-enhancing properties. Hence, this study was designed to explore the possible ameliorative effect of zinc in acrylamide-induced gonadotoxicity. METHODS: Twenty-four male Wistar rats were randomized into control, acrylamide (10 mg/kg of acrylamide), acrylamide + 1 mg/kg of zinc, and acrylamide + 3 mg/kg of zinc. The administration was via the oral route and lasted for 56 days. RESULTS: Zinc treatment ameliorated acrylamide-impaired sperm quality, normal testicular histoarchitecture, and hormonal balance, which was accompanied by increased testicular malondialdehyde and interleukin-1ß and decreased testicular superoxide dismutase (SOD) and catalase (CAT). Furthermore, zinc prevented acrylamide-induced downregulation of testicular nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and B-cell lymphoma 2 (BCl2) expression and upregulation of testicular nuclear factor kappa B (NF-κB) and bcl-2-like protein 4 (bax) expression. CONCLUSION: In conclusion, zinc may protect against acrylamide-induced testicular toxicity, mediated by its antioxidant, anti-inflammatory, and antiapoptotic effects.

Ivacaftor attenuates gentamicin-induced ototoxicity through the CFTR-Nrf2-HO1/NQO1 pathway.

OBJECTIVES: Gentamicin is one of the most common ototoxic drugs that can lower patients' quality of life. Oxidative stress is a key factors inducing sensory hair cell death during gentamicin administration. So far, there are no effective drugs to prevent or treat gentamicin- induced hearing loss. A recent study found cystic fibrosis transmembrane conductance regulator (CFTR) as a new target to modulate cellular oxidative balance. The objective of this study was to estimate the effect of the CFTR activator ivacaftor on gentamicin-induced ototoxicity and determine its mechanism. METHODS: The hair cell count was analyzed by Myosin 7a staining. Apoptosis was analyzed by TUNEL Apoptosis Kit. Cellular reactive oxygen species (ROS) level was detected by DCFH-DA probes. The Nrf2 related proteins expression levels were analyzed by western blot. RESULTS: An in vitro cochlear explant model showed that gentamicin caused ROS accumulation in sensory hair cells and induced apoptosis, and this effect was alleviated by pretreatment with ivacaftor. Western blotting showed that ivacaftor administration markedly increased the protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO1), and NAD(P)H:quinone oxidoreductase 1 (NQO1). The protective effect of ivacaftor was abolished by the Nrf2 inhibitor ML385. DISCUSSION: Our results indicate the protective role of the CFTR-Nrf2-HO1/NQO1 pathway in gentamicin-induced ototoxicity. Ivacaftor may be repositioned or repurposed towards aminoglycosides-induced hearing loss.

Cocoa flavanols, Nrf2 activation, and oxidative stress in peripheral artery disease: mechanistic findings in muscle based on outcomes from a randomized trial.

The pathophysiology of muscle damage in peripheral artery disease (PAD) includes increased oxidant production and impaired antioxidant defenses. Epicatechin (EPI), a naturally occurring flavanol, has antioxidant properties that may mediate the beneficial effects of natural products such as cocoa. In a phase II randomized trial, a cocoa-flavanol-rich beverage significantly improved walking performance compared with a placebo in people with PAD. In the present work, the molecular mechanisms underlying the therapeutic effect of cocoa flavanols were investigated by analyzing baseline and follow-up muscle biopsies from participants. Increases in nuclear factor erythroid 2-related factor 2 (Nrf2) target antioxidants heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase [quinone] 1 (NQO1) in the cocoa group were significantly associated with reduced accumulation of central nuclei, a myopathy indicator, in type II muscle fibers (P = 0.017 and P = 0.023, respectively). Protein levels of the mitochondrial respiratory complex III subunit, cytochrome b-c1 complex subunit 2 (UQCRC2), were significantly higher in the cocoa group than in the placebo group (P = 0.032), and increases in UQCRC2 were significantly associated with increased levels of Nrf2 target antioxidants HO-1 and NQO1 (P = 0.001 and P = 0.035, respectively). Exposure of non-PAD human myotubes to ex vivo serum from patients with PAD reduced Nrf2 phosphorylation, an indicator of activation, increased hydrogen peroxide production and oxidative stress, and reduced mitochondrial respiration. Treatment of myotubes with EPI in the presence of serum from patients with PAD increased Nrf2 phosphorylation and protected against PAD serum-induced oxidative stress and mitochondrial dysfunction. Overall, these findings suggest that cocoa flavanols may enhance antioxidant capacity in PAD via Nrf2 activation.NEW & NOTEWORTHY The current study supports the hypothesis that in people with PAD, cocoa flavanols activate Nrf2, thereby increasing antioxidant protein levels, protecting against skeletal muscle damage, and increasing mitochondrial protein abundance. These results suggest that Nrf2 activation may be an important therapeutic target for improving walking performance in people with PAD.

Erastin induces ferroptosis in cervical cancer cells via Nrf2/HO-1 signaling pathway.

OBJECTIVE: Our research aims to assess the influence of erastin, a ferroptosis-inducing agent, on cervical cancer cells. INTRODUCTION: Cervical cancer is a prevalent malignancy in females. Dysregulation of ferroptosis, a form of cell demise reliant on iron, is implicated in several cancers. METHODS: The effect of erastin on HeLa and SiHa was detected by transwell assay, scratch test, and colony formation assay, while cell apoptosis was detected using flow cytometry. Cellular reactive oxygen species (ROS) generation was detected using the dichloro-dihydro-fluorescein diacetate assay. Sequencing analysis identified differentially expressed genes (DEGs), and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Enrichment analyses were employed to identify the target gene. Subsequently, the utilization of small interfering RNA (siRNA) was employed to suppress the targeted gene expression in HeLa cells, thereby effectively mitigating the impact of erastin on various cellular processes including invasion, colony formation, migration, and ROS generation. RESULTS: The findings indicate that erastin attenuates the viability of both HeLa cells (IC50 = 30.88 µM) and SiHa cells (IC50 = 29.40 µM). Treatment with erastin at 10 µM inhibits the invasion, colony formation, and migration of both HeLa and SiHa cells within 24 h. Ferrostatin-1 (1 µM) notably alleviates the inhibitory effects of erastin of HeLa and SiHa cells. Upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream target, heme oxygenase-1 (HO-1), was found in erastin-treated cells compared to the control group. When knocked down HO-1 in HeLa cells, effectively counteracting the effects of erastin on the invasion, colony formation, migration, and ROS production in HeLa cells. CONCLUSION: Our research demonstrates that erastin induces ferroptosis and the accumulation of ROS in cervical cancer cells by activating the Nrf2/HO-1 pathway, significantly reducing cell proliferation and motility. These findings propose a potential molecular mechanism of erastin-mediated cervical cancer development.

Arctigenin Suppresses the Proliferation and Metastasis, and Induces Apoptosis and Cycle Arrest of Osteosarcoma Cells by inhibiting HMOX1 Expression.

BACKGROUND: Osteosarcoma is the most common malignant bone tumor, with highly proliferative and metastatic properties. Previous studies have reported that arctigenin (Arc), a bioactive lignin compound, showed excellent anti-tumor activities in a variety of human cancers. However, its role in osteosarcoma has not been studied. OBJECTIVE: We aimed to investigate the anti-tumor effects of Arc on osteosarcoma cell proliferation, migration, invasion, apoptosis, and cell cycle. METHODS: Effects of Arc on osteosarcoma cell proliferation were detected by MTT and colony formation assay. Flow cytometry analysis was performed to assess the cell apoptosis and cycle arrest. Transwell assay was used to evaluate the capability of migration and invasion. qRT-PCR and Western blot were employed to determine the changes in mRNA and protein levels. RESULTS: Arc could significantly suppress the proliferation, colony formation, and induce cell apoptosis and S phase cycle arrest of MG63 and U-2 OS cells in a dose-dependent manner. In addition, we also observed an inhibitory effect of Arc treatment on osteosarcoma cell invasion, migration, and epithelial-mesenchymal transition (EMT). HMOX1, encoding enzyme heme oxygenase-1, was predicted to be a candidate target of Arc using STITCH. Arc treatment significantly reduced the mRNA and protein levels of HMOX1. Furthermore, overexpression of HMOX1 could partly reverse the inhibitory effects of Arc on osteosarcoma cell malignant phenotypes. CONCLUSION: Our results suggest that Arc inhibits the proliferation, metastasis and promotes cell apoptosis and cycle arrest of osteosarcoma cells by downregulating HMOX1 expression.

CCR2-overexpressing biomimetic carrier-free nanoplatform for enhanced cascade ferroptosis tumor therapy.

Ferroptosis-based nanoplatforms have shown great potential in cancer therapy. However, they also face issues such as degradation and metabolism. Carrier-free nanoplatforms consisting of active drugs can effectively avoid the security issues associated with additional carrier ingredients. Herein, a biomimetic carrier-free nanoplatform (HESN@CM) was designed to treat cancer by modulating cascade metabolic pathways of ferroptosis. CCR2-overexpressing macrophage membrane-modified HESN can target cancer cells via the CCR2-CCL2 axis. The acidic tumor microenvironment (TME) can disrupt the supramolecular interaction of HESN, releasing hemin and erastin. Then, erastin could induce cancer cells ferroptosis by inhibiting system XC- pathways, while hemin, a vital component of blood to transport oxygen, could be broken down by heme oxygenase-1 (HO-1), increasing the intracellular Fe2+ concentration to induce cancer cells' ferroptosis further. Meanwhile, erastin could enhance the activity of HO-1, further promoting the release of Fe2+ from hemin. As a result, HESN@CM demonstrated superior therapeutic efficacy in both primary and metastatic tumors in vitro and in vivo. The carrier-free HESN@CM provided cascade ferroptosis tumor therapy strategies for potential clinical application. STATEMENT OF SIGNIFICANCE: CCR2-overexpressing biomimetic carrier-free nanoplatform (HESN@CM) was designed for cancer treatment by modulating metabolic pathways of ferroptosis. HESN modified with CCR2-overexpressing macrophage membrane can target tumor cells via the CCR2-CCL2 axis. HESN was composed of hemin and erastin without additional vectors. Erastin could directly induce ferroptosis, while hemin could be broken down by heme oxygenase-1 (HO-1), increasing the intracellular Fe2+ concentration to enhance ferroptosis further. Meanwhile, erastin could improve the activity of HO-1, promoting the release of Fe2+ from hemin. Therefore, HESN@CM with good bioavailability, stability, and simple preparation can realize cascade ferroptosis tumor therapy and have the potential prospect of clinical translation.

The antioxidant effect of preischemic dexmedetomidine in a rat model: increased expression of Nrf2/HO-1 via the PKC pathway

Abstract Background The precise underlying mechanism of antioxidant effects of dexmedetomidine-induced neuroprotection against cerebral ischemia has not yet been fully elucidated. Activation of Nuclear factor erythroid 2-related factor (Nrf2) and Heme Oxygenase-1 (HO-1) represents a major antioxidant-defense mechanism. Therefore, we determined whether dexmedetomidine increases Nrf2/HO-1 expression after global transient cerebral ischemia and assessed the involvement of Protein Kinase C (PKC) in the dexmedetomidine-related antioxidant mechanism. Methods Thirty-eight rats were randomly assigned to five groups: sham (n = 6), ischemic (n = 8), chelerythrine (a PKC inhibitor; 5 mg.kg-1 IV administered 30 min before cerebral ischemia) (n = 8), dexmedetomidine (100 µg.kg-1 IP administered 30 min before cerebral ischemia (n = 8), and dexmedetomidine + chelerythrine (n = 8). Global transient cerebral ischemia (10 min) was applied in all groups, except the sham group; histopathologic changes and levels of nuclear Nrf2 and cytoplasmic HO-1 were examined 24 hours after ischemia insult. Results We found fewer necrotic and apoptotic cells in the dexmedetomidine group relative to the ischemic group (p< 0.01) and significantly higher Nrf2 and HO-1 levels in the dexmedetomidine group than in the ischemic group (p< 0.01). Additionally, chelerythrine co-administration with dexmedetomidine attenuated the dexmedetomidine-induced increases in Nrf2 and HO-1 levels (p< 0.05 and p< 0.01, respectively) and diminished its beneficial neuroprotective effects. Conclusion Preischemic dexmedetomidine administration elicited neuroprotection against global transient cerebral ischemia in rats by increasing Nrf2/HO-1 expression partly via PKC signaling, suggesting that this is the antioxidant mechanism underlying dexmedetomidine-mediated neuroprotection.

Biogenic silver NPs alleviate LPS-induced neuroinflammation in a human fetal brain-derived cell line: Molecular switch to the M2 phenotype, modulation of TLR4/MyD88 and Nrf2/HO-1 signaling pathways, and molecular docking analysis.

Silver nanoparticles (AgNPs) have inconsistent findings against inflammation. Although a wealth of literature on the beneficial effects of green-synthesized AgNPs has been published, a detailed mechanistic study of green AgNPs on the protective effects against lipopolysaccharide (LPS)-induced neuroinflammation using human microglial cells (HMC3) has not yet been reported. For the first time, we studied the inhibitory effect of biogenic AgNPs on inflammation and oxidative stress induced by LPS in HMC3 cells. X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and transmission electron microscopy were used to characterize AgNPs produced from honeyberry. Co-treatment with AgNPs significantly reduced mRNA expressions of inflammatory molecules such as interleukin (IL)-6 and tumor necrosis factor-α, while increasing the expressions of anti-inflammatory markers such as IL-10 and transforming growth factor (TGF)-ß. HMC3 cells were also switched from M1 to M2, as shown by lower expression of M1 markers such as cluster of differentiation (CD)80, CD86, and CD68 and higher expression of M2 markers such as CD206, CD163, and triggering receptors expressed on myeloid cells (TREM2). Furthermore, AgNPs inhibited LPS-induced toll-like receptor (TLR)4 signaling, as evidenced by decreased expression of myeloid differentiation factor 88 (MyD88) and TLR4. In addition, AgNPs reduced the production of reactive oxygen species (ROS) and enhanced the expression of nuclear factor-E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), while decreasing the expression of inducible nitric oxide synthase. The docking score of the honeyberry phytoconstituents ranged from -14.93 to - 4.28 KJ/mol. In conclusion, biogenic AgNPs protect against neuroinflammation and oxidative stress by targeting TLR4/MyD88 and Nrf2/HO-1 signaling pathways in a LPS-induced in vitro model. Biogenic AgNPs could be utilized as potential nanomedicine against LPS-induced inflammatory disorders.

Identification of Nrf2 Activators from the Roots of Valeriana officinalis.

Various age-related chronic diseases have been linked to oxidative stress. The cellular antioxidant response pathway is regulated by the transcription factor nuclear erythroid factor 2. Therefore, plant-derived nuclear erythroid factor 2 activators might be useful therapeutics to stimulate the body's defense mechanisms. Our study focused on the discovery of potent nuclear erythroid factor 2 activators from medicinal plants. Initially, a variety of medicinal plant extracts were screened for nuclear erythroid factor 2 activity using a nuclear erythroid factor 2 luciferase reporter cell line. Among these, Valerian (Valeriana officinalis) root was identified as a potent candidate. Sequential extraction and bioassay-guided fractionation led to the isolation of four nuclear erythroid factor 2-active compounds, which were structurally identified by NMR and LC/HRMS as the known compounds isovaltrate, valtrate, jatamanvaltrate-P, and valerenic acid. These four compounds were then tested in relevant biological assays. Firstly, their effects on the expression of glutathione S-transferase, glutamate-cysteine ligase catalytic subunit, glutathione peroxidase, and heme oxygenase 1 were determined in HepG2 cells. Glutathione S-transferase P1 and glutamate-cysteine ligase catalytic subunit were upregulated by isovaltrate, valtrate, and jatamanvaltrate-P, while heme oxygenase 1 was upregulated by isovaltrate, jatamanvaltrate-P, and valerenic acid. The four compounds also increased the levels of glutathione and its metabolite, CysGly. As glutathione aids in the detoxification of hydrogen peroxide, cytoprotective effects of these four nuclear erythroid factor 2 activators against hydrogen peroxide toxicity were investigated, and indeed, the compounds significantly improved cell survival. This study provides evidence that four valepotriates from the roots of V. officinalis are activators of nuclear erythroid factor 2-mediated antioxidant and detoxification pathways. Our data might expand the medical use of this plant beyond its current application as a sleep aid.

HMOX1 silencing prevents doxorubicin-induced cardiomyocyte injury, mitochondrial dysfunction, and ferroptosis by downregulating CTGF.

OBJECTIVES: Doxorubicin is a type of effective antitumor drug but can contribute to cardiomyocyte injuries. We aimed to dissect the mechanism of the HMOX1/CTGF axis in DOX-induced cardiomyocyte injury, mitochondrial dysfunction, and ferroptosis. METHODS: Bioinformatics analysis was conducted to retrieve differentially expressed genes in a DOX-induced mouse model. Mouse cardiomyocytes, HL-1 cells, were induced with l µM DOX, after which gain- or loss-of-function assays were applied. CCK-8, fluorescent probe assay, flow cytometry, and corresponding kits were employed to detect cell viability, ROS levels, mitochondrial membrane potential and cell apoptosis, and GSH and Fe2+ contents, respectively. qRT-PCR or Western blot assay was adopted to test HMOX1, CTGF, BCL-2, Caspase3, Cleaved-Caspase3, and GPX4 expression. RESULTS: Bioinformatics analysis showed that HMOX1 and CTGF were highly expressed in DOX-induced mice and correlated with each other. Also, HMOX1 and CTGF expression was high in HL-1 cells after DOX treatment, along with an obvious decrease in cell viability and GSH and GPX4 expression, an increase in ROS levels, apoptosis, and Fe2+ contents, and mitochondrial membrane potential dysfunction or loss. HMOX1 or CTGF silencing diminished cell apoptosis, Cleaved-Caspase3 expression, Fe2+ contents, and ROS levels, enhanced cell viability and the expression of GSH, GPX4, and BCL-2, and recovered mitochondrial membrane potential in DOX-induced HL-1 cells. Nevertheless, the effects of HMOX1 silencing on the viability, apoptosis, ferroptosis, and mitochondrial dysfunction of DOX-induced HL-1 cells were counteracted by CTGF overexpression. CONCLUSIONS: In conclusion, HMOX1 silencing decreased CTGF expression to alleviate DOX-induced injury, mitochondrial dysfunction, and ferroptosis of mouse cardiomyocytes.

Effects of CEACAM1 in oral keratinocytes on HO-1 expression induced by Candida ß-glucan particles.

OBJECTIVE: Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a member of the carcinoembryonic antigen family. Although its expression has been found in chronic oral inflammatory epithelium, this study aimed to know whether CEACAM1 in oral keratinocytes participates in host immune response against Candida albicans . METHODOLOGY: We investigated CEACAM1 expression in oral keratinocytes induced by C. albicans as well as by Candida cell wall component ß-glucan particles (ß-GPs). Furthermore, the effects of CEACAM1 on ß-GPs-induced heme oxygenase-1 (HO-1) expression and its related signals were examined. RESULTS: Fluorescence staining showed CEACAM1 expression in oral keratinocytes (RT7) cells, whereas quantitative reverse transcription (RT)-PCR indicated that both live and heat-killed C. albicans increased CEACAM1 mRNA expression in RT7 cells. Examinations using quantitative RT-PCR and western blotting indicated that CEACAM1 expression was also increased by ß-GPs derived from C. albicans . Specific siRNA for CEACAM1 decreased HO-1 expression induced by ß-GPs from C. albicans as well as the budding yeast microorganism Saccharomyces cerevisiae . Moreover, knockdown of CEACAM1 decreased ß-GPs-induced ROS activity in the early phase and translocation of Nrf2 into the nucleus. CONCLUSION: CEACAM1 in oral keratinocytes may have a critical role in regulation of HO-1 for host immune defense during Candida infection.

[Astragaloside IV inhibits oxidative stress-mediated apoptosis of human SY5Y cells by activating Nrf-2/HO-1 signaling pathway].

Objective To investigate the protective effect and mechanism of astragaloside IV (AST4) on H2O2-induced oxidative stress injury and apoptosis of SY5Y cells. Methods Human SY5Y cells were cultured in vitro and induced by H2O2 to establish oxidative stress model, which was divided into PBS group, H2O2 group and AST4 group. Cell viability was determined by MTT assay. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL). The supernatant was used to determine the activity of malondialdehyde (MAD), superoxide dismutase (SOD) and glutathione (GSH) in each group. Immunofluorescence cytochemistry was used to detect the nuclear factor E2-related factor (Nrf-2) and cleaved caspase-3 (c-caspase-3). B-lymphoblastoma-2 (Bcl2), Bcl2-associated X protein (BAX), c-caspase-3, Nrf-2 in cells and nuclei and heme oxygenase-1 (HO-1) were determined by Western blot analysis. Results AST4 had a protective effect on viability of SY5Y cells under oxidative stress damage, reduced the content of MAD, and increased the content of GSH and SOD. AST4 increased Bcl2 and decreased BAX, thus Bc12/BAX ratio was significantly increased compared with that in H2O2 group. Meanwhile, AST4 inhibited the expression of c-caspase-3. AST4 promoted nuclear translocation of Nrf-2 and increased the expression of the downstream antioxidant protein HO-1. Conclusion AST4 can promote Nrf-2 nuclear translocation, increase HO-1 expression, regulate oxidation/antioxidant balance, improve antioxidant level, protect cells from oxidative damage and reduce apoptosis by activating Nrf-2/HO-1 signaling pathway.

Forsythiaside Protected H9c2 Cardiomyocytes from H2O2-Induced Oxidative Stress and Apoptosis via Activating Nrf2/HO-1 Signaling Pathway.

Forsythiaside, one of the main bioactive components of Chinese medicine Lian Qiao, exerts antioxidant, anti-bacterial, and anti-inflammatory effects. To date, the mechanism of Forsythiaside in cardiomyocyte injury remains unclear. However, the antioxidant effects of Forsythiaside on cardiac cells are currently unknown. This study investigated the effect and mechanism of Forsythiaside on oxidative stress in H9c2 cardiomyocytes. H9c2 cells were treated with H2O2 and Forsythiaside and then transfected with small-interfering RNA against nuclear factor erythroid 2-related factor 2 (siNrf2). Cell viability, apoptosis, accumulation of reactive oxygen species (ROS), and mitochondrial membrane potential were measured using methyl thiazolyl tetrazolium (MTT), terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) assay, fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), and rhodamine 123, respectively. The levels of oxidative stress-related markers were determined using their respective detection kits. Furthermore, the levels of apoptosis- and Nrf2 pathway-related molecules were determined via Western blot and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Forsythiaside had no obvious toxicity on H9c2 cells. H2O2 suppressed the viability, and reduced the levels of mitochondrial membrane potential, B-cell lymphoma-2 (Bcl-2), glutathione peroxidase (GSH-Px) and catalase (CAT) and superoxide dismutase (SOD), while promoted apoptosis, ROS accumulation, and elevated the levels of cleaved caspase 3, BCL2-Associated X (Bax) and malondialdehyde (MDA) in H9c2 cells. Contrarily, Forsythiaside reversed the aforementioned effects. H2O2 advanced the levels of cytoplasm Nrf2, heme oxygenase-1 (HO-1), and nucleus Nrf2 in H9c2 cells, whereas Forsythiaside enhanced these effects. SiNrf2 reversed the functions of H2O2 or Forsythiaside in cell viability, MDA, SOD, GSH-Px, CAT, Nrf2, and HO-1 in H9c2 cells, whereas Forsythiaside reversed the aforementioned effects of siNrf2. In sum, Forsythiaside protected H9c2 cells from oxidative stress and apoptosis induced by H2O2 by activating the Nrf2/HO-1 pathway.

The protective effect of proanthocyanidins on the psoriasis-like cell models via PI3K/AKT and HO-1.

BACKGROUND: Inflammation and oxidative stress (OS) are important contributors to psoriasis pathogenesis. Proanthocyanidins (PCs) have anti-inflammatory and anti-oxidative activities. Previously, we discovered that PCs alleviated psoriasis-like mice symptoms, likely via mitigating inflammation and OS damage. OBJECTIVE: To elucidate the protective mechanism underlying PCs against the damage of TNF-ɑ-induced psoriasis-like cell models. METHODS: Psoriasis-like cell models were established with 7.5 ng/mL TNF-ɑ and then subjected to different-concentrations PCs treatment. Finally, inflammatory and oxidative parameters were determined. Besides, LY294002 (PI3K inhibitor) and ZnPP (HO-1 inhibitor) were employed to investigate the roles of PI3K/AKT and HO-1 in PCs against psoriasis-like cell models. RESULTS: After TNF-α treatment, cells organized tightly and proliferated greatly (P<0.01); HO-1 expression dropped obviously, along with the increased OS/inflammatory indicators and the decreased antioxidants (P<0.05); consequently, psoriasis-like cell models were well established. In the presence of PCs, nevertheless, the proliferation rate and number of psoriasis-like cells evidently decreased (P<0.01), accompanied with enhanced HO-1 and antioxidants, and lowered OS/inflammatory indicators as well as phosphorylated JAK2/STAT3/PI3/AKT (P<0.01). Similar changes appeared after LY294002 pretreatment, regardless of PCs or not. But after ZnPP pretreatment with or without PCs, the opposite occurred. CONCLUSION: The study reveals that PCs can suppress psoriasis-like cell proliferation and reduce inflammatory/OS damage through PI3K/AKT inhibition and HO-1 activation, thus promising a candidate for PCs in treating psoriasis.

Overexpression of long noncoding RNA LINC00638 inhibits inflammation and oxidative stress in rheumatoid arthritis fibroblast-like synoviocytes by regulating the Nrf2/HO-1 pathway.

BACKGROUND: Abnormal expression of long noncoding RNAs (lncRNAs) is involved in several autoimmune diseases including rheumatoid arthritis (RA). In this study, we intended to explore the expression of lncRNA LINC00638 in RA and its potential mechanism of action related to inflammation and oxidative stress. METHODS: The level of LINC00638 in the peripheral blood mononuclear cells (PBMCs) obtained from 45 RA patients and 30 normal controls was analyzed and its correlation with clinical indicators was investigated. In vitro, we used tumor necrosis factor-α to stimulate fibroblast-like synoviocytes (FLS) of RA patients for cell based experiments. Subsequently, the overexpressed plasmid and small interfering RNA of LINC00638 were designed. Furthermore, we further analyzed the potential effects of LINC00638 on the proliferation and migration of RA-FLS and the nuclear factor erythrocyte derived 2 related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway. RESULTS: LINC00638 expression was found to be significantly decreased in PBMCs of RA patients, and it was negatively correlated with erythrocyte sedimentation rate, interleukin (IL)-17, reactive oxygen species (ROS), and disease activity scores for 28 joints (DAS28). Overexpression of LINC00638 activated the Nrf2/HO-1 pathway, markedly decreased the expressions of IL-6, IL-17, IL-23, ROS, as well as malondialdehyde, increased the total antioxidant capacity, and attenuated the proliferation and migration of RA-FLS, while silencing of LINC00638 reversed these manifestations. CONCLUSIONS: LINC00638 was found to be expressed at low levels in RA patients and was associated with immune inflammation, oxidative stress, and disease activity. Overexpression of LINC00638 can reduce the proliferation as well as migration of RA-FLS, and activate the Nrf2/HO-1 pathway to inhibit the inflammation and oxidative stress.

Effects of Preconditioning With Transcutaneous Electrical Nerve Stimulation Monitored by Infrared Thermography on the Survival of Pedicled Perforator Flaps in a Rat Model.

OBJECTIVE: Pedicled perforator partial or complete necrosis with a rate of 13.7%. This study was undertaken to test whether preconditioning with transcutaneous electrical nerve stimulation (TENS) monitored by infrared thermography protect against partial necrosis by converting the choke anastomoses to the true anastomoses via inducing heme oxygenase-1 (HO-1) in a rat pedicled perforator flap model. METHODS: Seventy-two Sprague-Dawley rats were randomly assigned to the control, the TENS, the TENS + SnPP (tin protoporphyrin; HO-1 activity inhibitor; 50 µmol/kg) and the TENS +0.9% saline groups. On the unilateral dorsum of the rats, a rectangular flap donor site of 11 × 3 cm was marked out, which contained three perforator angiosomes and two choke zones. On days 1, 3 and 4, 1 hour of TENS (biphasic pulses, 25 mA, 80 Hz, 200 µs) was applied to the flap donor sites, respectively. On day 5, after the flap donor sites were assessed by infrared thermography, the flaps were harvested based on the deep circumflex iliac artery perforator. RESULTS: Infrared thermography showed that the choke zones in the flap donor sites presented white in the TENS and the TENS +0.9% saline groups, whereas they presented red in the control and the TENS + SnPP groups. Postmortem arteriography showed that the number of arterioles across each choke zone significantly increased in the TENS and the TENS +0.9% saline groups compared with the control and the TENS + SnPP groups. Immunohistochemistry and western blot showed a significant increase in HO-1 in the choke zones after TENS preconditioning. The necrotic area percentage of the flaps was significantly decreased in the TENS (4.3% ± 2.6%) and the TENS +0.9% saline groups (4.5% ± 2.3%) compared with the control (24.8% ± 5.0%) ( P < 0.001); there was no significant difference between the TENS and the TENS + SnPP (24.4% ± 7.3%) groups. CONCLUSIONS: These data show that TENS preconditioning monitored by infrared thermography might be a promising strategy to prevent pedicled perforator flaps from partial necrosis.

Curcumin analog, GO-Y078, induces HO-1 transactivation-mediated apoptotic cell death of oral cancer cells by triggering MAPK pathways and AP-1 DNA-binding activity.

BACKGROUND: GO-Y078, a new synthetic analogue of curcumin (CUR), has higher oral bioavailability and anticancer activity than CUR, but the oncostatic effect of GO-Y078 on oral squamous cell carcinoma (OSCC) is largely unknown. RESEARCH DESIGN AND METHODS: In the present study, we examined the oncostatic properties and possible mechanisms of GO-Y078 on human SCC-9 and HSC-3 OSCC cells. RESULTS: Our results indicated that GO-Y078 showed a cytostatic effect against OSCC cells, and this antiproliferative phenomenon stemmed from a mechanism involving multiple levels of cooperation, including cell-cycle G2/M arrest and apoptosis induction. Mechanistically, GO-Y078 treatment induced caspase-mediated apoptosis via upregulating two apoptosis-modulating proteins, SMAC/DIABLO and heme oxygenase (HO)-1. GO-Y078 transcriptionally induced upregulation of the HO-1 gene by increasing the AP-1 DNA-binding activity, which was initiated by activation of the p38 /JNK1/2 pathways. In the clinic, patients with head and neck cancers expressed lower HO-1 and SMAC/DIABLO levels in primary cancer tissues compared to normal tissues. Clinical datasets also revealed that patients with head and neck cancers expressing high HO-1 had afavorable prognosis. CONCLUSIONS: Our results provide new insights into the role of GO-Y078-induced molecular regulation in suppressing OSCC growth and suggest that GO-Y078 has potential therapeutic applications for OSCC.

Sagittaria sagittifolia polysaccharide protects against six-heavy-metal-induced hepatic injury associated with the activation of Nrf2 pathway to regulate oxidative stress and apoptosis.

The hepatic protective role of Sagittaria sagittifolia polysaccharide (SSP) and its possible mechanism were discussed in mice and L02 hepatocytes injured by heavy metals mixture of Cd + Cr (VI) + Pb + Mn + Zn + Cu. After 30-day intervention, blood and liver samples were collected for the relevant assessments. Methyl thiazolyl tetrazolium (MTT) assay showed 24 h was the best protecting point and the SSP protection at 1 mg/mL was strongest in L02 hepatocytes. SSP can alleviated hepatic injury, as evidenced by significantly decreased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and the malondialdehyde (MDA) content, also increased the superoxide dismutase (SOD) activity and glutathione (GSH), total sulphydryl (T-SH) contents. SSP effectively reduced pathological damage of mice and accumulation of heavy metals in liver, as well as decreased the level of reactive oxygen species (ROS) in L02 hepatocytes. After SSP treatment, the protein expressions or gene transcription of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H dehydrogenase, quinone 1 (NQO1) and heme oxygenase1 (HO-1) decreased in L02. The protein expression of Nrf2 and NQO1 were increased while HO-1 was decreased in liver. Besides, SSP can attenuates apoptosis through reducing the protein expression of Bcl-2-associated X protein (Bax) and caspase-3, and increasing B-cell lymphoma gene 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl). SSP protects against six-heavy-metal-induced hepatic injury in mice and L02 hepatocytes. Supported by Nrf2 gene silencing, the mechanisms may correlate with activating Nrf2 pathway to mitigate oxidative stress and apoptosis.

Heme Oxygenase-1 targeting exosomes for temozolomide resistant glioblastoma synergistic therapy.

Glioblastoma (GBM) is a highly fatal and recurrent brain cancer without a complete prevailing remedy. Although the synthetic nanotechnology-based approaches exhibit excellent therapeutic potential, the associated cytotoxic effects and organ clearance failure rest major obstacles from bench to clinics. Here, we explored allogeneic bone marrow mesenchymal stem cells isolated exosomes (BMSCExo) decorated with heme oxygenase-1 (HMOX1) specific short peptide (HSSP) as temozolomide (TMZ) and small interfering RNA (siRNA) nanocarrier for TMZ resistant glioblastoma therapy. The BMSCExo had excellent TMZ and siRNA loading ability and could traverse the blood-brain barrier (BBB) by leveraging its intrinsic brain accumulation property. Notably, with HSSP decoration, the TMZ or siRNA encapsulated BMSCExo exhibited excellent TMZ resistant GBM targeting ability both in vitro and in vivo due to the overexpression of HMOX1 in TMZ resistant GBM cells. Further, the HSSP decorated BMSCExo delivered the STAT3 targeted siRNA to the TMZ resistant glioma and restore the TMZ sensitivity, consequently achieved the synergistically drug resistant GBM treatment with TMZ. Our results showed this biomimetic nanoplatform can serve as a flexible, robust and inert system for GBM treatment, especially emphasizing the drug resistant challenge.

Toxicological mechanism of large amount of copper supplementation: Effects on endoplasmic reticulum stress and mitochondria-mediated apoptosis by Nrf2/HO-1 pathway-induced oxidative stress in the porcine myocardium.

Copper (Cu) is an essential micronutrient that is required by all living organisms. However, Cu can also be a potentially toxic metal if excessive dietary supplementation occurs. The current study aimed to investigate the mechanism of Cu toxicity in the cardiomyocytes of large mammal pigs. Here, we used pigs to explore Cu toxicity in the control group (10 mg/kg Cu) and treatment groups (125 mg/kg and 250 mg/kg Cu) for a period of 80 days. Consequently, we identified that large amount intake of Cu led to in oxidative damage, and activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1)-mediated antioxidant pathway, indicating an imbalanced redox status in the myocardium. Furthermore, Cu exposure activated endoplasmic reticulum (ER) stress through upregulating levels of glucose-regulated protein 78 (GRP78), c-Jun N-terminal kinase (JNK), glucose-regulated protein 94 (GRP94), X-box binding protein 1 (XBP1), and C/EBP homologous protein (CHOP). Additionally, mitochondrial fission and fusion homeostasis was disrupted and the copy number of mitochondrial DNA (mtDNA) was reduced under Cu exposure. Furthermore, Cu exposure could induce apoptosis, evidenced by the increased terminal deoxynucleotidyl transferase biotin-d UTP nick end labeling (TUNEL)-positive staining, the upregulated expression levels of Cytoplasm-cytochrome C (Cytc), Bcl-2-associated X protein (Bax), and Cleaved-caspase3, and decreased expression level of B-cell lymphoma-2 (Bcl-2) and Mitochondrial-cytc. In summary, large amount of Cu could trigger Nrf2/HO-1 pathway-mediated oxidative stress, which promotes ER stress and mitochondrial damage pathways, causing apoptosis in cardiomyocytes.