Heme Oxygenase-1 Expression Research Articles

IMMU-33. REPROGRAMMING OF MYELOID CELL METABOLISM VIA HEME OXYGENASE-1 INHIBITION POTENTIATES ANTI-TUMOR IMMUNITY IN A MURINE GLIOMA MODEL

Abstract Cancer cells exhibit a preference for aerobic glycolysis, a phenomenon known as the Warburg effect. Emerging evidence suggests that immune cells within the tumor microenvironment (TME) may employ a similar metabolic adaptation. Heme oxygenase-1 (HMOX-1), a metabolic regulatory gene, is elevated in myeloid cells of glioblastoma (GBM), yet its precise role in modulating immune suppression and energy utilization remains unclear. Our objective was to explore how targeting HMOX-1 activity in the GBM TME affects immune response and energy metabolism. We utilized syngeneic glioma models with C57BL/6J mice implanted with CT-2A cells, which were randomized into four treatment arms: intracranial (IC) injection of the HMOX-1 inhibitor zinc protoporphyrin (ZnPP), intraperitoneal (IP) injection of anti-PD-1, IC ZnPP + IP anti-PD-1, or IC saline (sham). For mechanistic studies, we developed a myeloid-specific knockdown model via adoptive cell transfer of myeloid-derived suppressor cells (MDSCs) transfected with Hmox-1 siRNA into CSF-1R myeloid-depleted mice. Immunophenotyping was conducted with flow cytometry. The Seahorse mitochondrial stress test was used for evaluation of energy dynamics. Downregulation of myeloid Hmox-1 expression and inhibition of HMOX-1 via ZnPP both led to heightened T cell activation, with increased IFN-γ expression in brain compared to untreated mice (P=0.039, 0.02, respectively). Notably, ZnPP treatment induced a compensatory elevation of PD-L1 in myeloid cells (P<0.0001). Both ZnPP monotherapy and anti-PD-1 + ZnPP combination therapy demonstrated enhanced median overall survival rates in comparison to sham and anti-PD-1 monotherapy groups, with the combined approach yielding the most significant survival advantage (P<0.0001). Metabolic analyses following Hmox-1 knockdown and ZnPP treatment revealed a shift away from cancer-like glycolytic shunting in MDSCs. Inhibiting the HMOX-1 pathway facilitated T cell activation and reversal of glycolysis-predominant metabolism in MDSCs, resulting in improved survival outcomes in a murine glioma model. Modulation of metabolic reprogramming in myeloid cells may potentiate anti-tumor immunity, especially in conjunction with checkpoint blockade.

5-Aminolevulinic acid combined with ferrous iron ameliorates myocardial ischemia/reperfusion injury by increasing heme oxygenase-1.

5-Aminolevulinic acid (5-ALA) is a naturally occurring metabolic precursor of heme, and 5-ALA combined with ferrous iron can induce heme oxygenase-1 (HO-1) in various cells. In this study, we investigated the cardioprotective effect of 5-ALA after myocardial ischemia/reperfusion (I/R) injury using a murine model. Male C57BL/6J mice (10-12weeks of age and weighing 21-26g) were pretreated with 100mg/kg of 5-ALA hydrochloride and 157mg/kg of sodium ferrous citrate (SFC) or vehicle 48h, 24h, and 1h before I/R, and underwent 50min of left coronary artery occlusion followed by reperfusion. Infarct area (IA) and area at risk (AAR) were determined by Evans blue and triphenyltetrazolium chloride double staining after reocclusion. Pre-administration with 5-ALA/SFC significantly reduced IA/AAR compared with placebo (34.0% vs. 51.7%, respectively; p = 0.001). Real-time PCR assay after reperfusion showed that mRNA expressions of TNF-α, IL-1β, and BNP were significantly lower, and that of HO-1 was significantly higher in the 5-ALA/SFC group than in the vehicle group in ischemic sites. An inhibition experiment revealed that zinc protoporphyrin IX, an inhibitor of HO-1, inhibited the cardioprotective effects of 5-ALA/SFC. These results suggest that 5-ALA/SFC might play a cardioprotective role in myocardial I/R injury by attenuating the inflammatory reaction by increasing the expression of HO-1.

Ginsenoside Rb1 targets to HO-1 to improve sepsis by inhibiting ferroptosis

Sepsis remains the leading cause of mortality among Intensive Care Unit (ICU) patients, with its pathogenesis and treatment not yet fully elucidated. Ferroptosis plays a critical role in sepsis, suggesting that ferroptosis-related genes may serve as potential therapeutic targets. This study aims to identify key ferroptosis-related genes in sepsis and explore targeted therapeutics. Through differential expression analysis of the GSE13940 and GSE26440 datasets, heme oxygenase-1 (HO-1) was identified as a hub gene associated with ferroptosis. Additionally, single-cell analysis of the GSE175453 dataset revealed a significant upregulation of HO-1 expression in monocyte lineages during sepsis. The cecal ligation and puncture (CLP) method was employed to induce sepsis in a mouse model, lung and intestinal tissues exhibited typical ferroptosis characteristics, with a significant increase in HO-1 expression. However, treatment with the HO-1 inhibitor zinc protoporphyrin (ZNPP) significantly ameliorated ferroptosis in CLP-induced lung and intestinal tissues, as well as in lipopolysaccharide (LPS)-induced THP-1 cells. Subsequently, molecular docking, surface plasmon resonance (SPR), and microscale thermophoresis (MST) experiments demonstrated that ginsenoside Rb1 specifically targets HO-1, identifying K18A as the key binding residue. Finally, experiments conducted both in vitro and in vivo verified that ginsenoside Rb1 significantly reduces HO-1 expression, inhibits ferroptosis in sepsis-induced lung, and intestinal tissues and THP-1 cells, and improves sepsis-induced pulmonary and intestinal damage. In conclusion, this study identifies HO-1 as a key ferroptosis target in sepsis and suggests ginsenoside Rb1 as a potential novel HO-1 inhibitor for the therapeutic approach of sepsis-induced organ dysfunction.

Acupoint Autohemotherapy Alleviates Airway Inflammation in Asthmatic Rats via Upregulating Expression of Hemeoxygenase-1.

Acupoint autohemotherapy (AA), a therapeutic technique involving the subcutaneous injection of autologous blood into acupoints, has been empirically validated as safe and effective for treating asthma by alleviating symptoms and decreasing acute attacks, though its mechanism is not well understood. The role of heme oxygenase-1 (HO-1) in AA-induced suppression of asthmatic airway inflammation is examined. Twenty rats were assigned randomly to four groups, namely the Control, OVA, OVA + AA, and (OVA + Snpp) + AA. Rats in the OVA + AA and (OVA + Snpp) + AA received autologous blood injections into acupoints (BL13 and BL23) following OVA challenge. Rats in the (OVA + Snpp) + AA were concurrently subjected to intraperitoneal injections of Snpp, a inhibitor of HO-1. Airway inflammation was evaluated through HE staining, while the concentrations of cytokines in BALF were quantified using ELISA. The mRNA and protein levels of RORγt (Th17-specific transcription factor), Foxp3 (Treg-specific transcription factor), and HO-1 in lung tissue were assessed through qRT-PCR and WB. HE staining indicated that airway inflammation was alleviated in the OVA + AA. The OVA + AA displayed significantly lower counts of total cells and eosinophils in the BALF compared to both the OVA and (OVA + Snpp) + AA. The ELISA demonstrated a significant decrease in levels of pro-inflamatory cytokines (IL-4, IL-17A), and an increase in levels of anti-inflamatory cytokines (IFN-γ, IL-10), in the OVA + AA when compared to both OVA and (OVA + Snpp) + AA. The qRT-PCR and WB analyses revealed an upregulation of HO-1 and Foxp3 expression, and a downregulation of RORγt expression, in the OVA + AA when compared to OVA and (OVA + Snpp) + AA. The involvement of HO-1 in the underlying mechanism responsible for the anti-inflammatory effects of AA is evident.

The Role of Changes in the Redox Status in the Pathogenesis of Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia is a hemoblastosis of CD5+ B lymphocytes with lymphocytosis, damage to the lymphatic organs, occurring in the older age group, the etiology and pathogenesis of which are not fully understood. Oxidative stress is an important factor in the regulation of stem cells and the activation of intracellular survival signaling pathways in chronic lymphocytic leukemia cells. The aim of the study was to analyze the current data on the role of redox status changes in the pathogenesis of chronic lymphocytic leukemia. A review of published relevant studies 2018-2023, scientific articles in scientific electronic bibliographic databases PubMed and Social Sciences Citation Index, devoted to the pathogenesis of chronic lymphocytic leukemia and the role of free-radical oxidation processes in it was carried out. In chronic lymphocytic leukemia, oxidative stress with a systemic excess of reactive oxygen species, an imbalance in the effectiveness of antioxidant defense is caused mainly by activation of oxidative phosphorylation in mitochondria, low levels of NADPH-oxidase type 2, increased expression of heme oxygenase-1, glutathione peroxidase and glutathione recycling enzymes, superoxide dismutase-2, thioredoxins and decreased expression of catalase. One of the mechanisms of resistance to drug therapy and oxidative stress of chronic lymphocytic leukemia cells is the intracellular signaling pathway dependent on erythroid nuclear factor-2, due to the activation of expression in cells of superoxide dismutase-2, catalase, glutathione peroxidase, peroxiredoxin-3 and-5, heme oxygenase-1, thioredoxin-1 and -2, reduced glutathione, natural killer cell activity, which is associated with lifespan, chemotaxis, proliferation, and survival. FOXO family proteins are believed to suppress carcinogenesis. FOXO3a increases the expression of superoxide dismutase-2, catalase, glutathione peroxidase, peroxiredoxin-3 and -5, and the activity of natural killer cells, which promotes the survival of tumor cells. The development of new targeted pharmacological agents that are capable of accumulating reactive oxygen species and reducing antioxidant protection due to the degradation of erythroid nuclear factor-2 and activation of NADPH-quinone oxidoreductase-1 is underway, which modernizes the therapy of chronic lymphocytic leukemia.

Long non-coding RNA PANDA promotes endothelial senescence and oxidative damage through the interaction with NRF2

Abstract Background Accumulation of reactive oxygen species and inflammation are major features of diabetic vasculopathy, yet the underlying mechanisms remain elusive. LncRNAs are emerging as important players in the pathogenesis of cardiovascular disease. PANDA, a newly identified lncRNA, is a key regulator of cellular senescence, apoptosis and oxidative stress. Purpose To investigate the role and molecular mechanism of PANDA in diabetic vascular disease. Methods RNAseq was performed to aorta specimen from diabetic and no diabetic patients as well to HAECs exposed to 5 mM and 25 mM concentrations (Normal -NG- and High -HG-, respectively). PANDA depletion in HG-treated HAECs was obtained by siRNA transfection while a scrambled siRNA wass used as a negative control. RNAseq and network perturbation analysis (NPA) of treated HAECs unveiled transcriptional changes upon PANDA depletion. Expression of PANDA was assessed by real time PCR. PANDA RNA-IP was performed to check its binding to relevant transcriptional factor (such as NRF2) as well Ch-IP was performed to check the NRF2 binding on oxidative gene promoters. Cellular localization of NRF2 was investigated by Immunofluorescence. Beta-galactosidase and superoxide staining was used to detect endothelial senescence and ROS formation; while, migration and tube formation were employed to evaluate angiogenic properties of HAECs. Results PANDA expression was significantly increased in diabetic human aorta as well in HG-treated HAECs (Figure1 A-B). Transcriptomic analysis revealed dysregulation of several genes upon PANDA silencing with the antioxidant gene heme oxygenase-1 (HMOX1) as the top-ranking transcript in HG cells (Figure1 C-D). Western blot analysis reveals the restored level of HMOX1 and TFRC1 upon PANDA depletion (Figure1 E-G). NPA analysis showed a strong involvement of PANDA in senescence, DNA damage, NRF2 signaling, hypoxic stress response and proliferation. In HG, NFR2 is downregulated while PANDA silencing restores its level (Figure1 I-J). We found that in HG condition PANDA binds the transcription factor NRF2 and blocks its nuclear translocation thus impeding its binding on HMOX1 and TFRC promoters (Figure1 K-M). Silencing of PANDA in HG-treated HAECs reduced genes and cellular features of senescence (Figure2 A-B), restored the expression of anti-apoptotic genes and decreases caspase 3 activity (Figure2 C-D), improved endothelial migration and tube formation (Figure2 E and G), and reduced ROS formation (Figure2 F). Conclusions In hyperglycemia PANDA upregulation drives endothelial senescence while impairing angiogenic properties. On the other hand, PANDA depletion in HG-treated HAECs rescues maladaptive transcriptional changes through the release of NRF2 that in turn translocate into the nucleus enhancing the expression of the antioxidant gene HMOX1. The results indicate PANDA as a putative novel molecular target in the setting of diabetic vascular disease (Figure2 H).

Probiotic Characteristics and the Anti-Inflammatory Effects of Lactiplantibacillus plantarum Z22 Isolated from Naturally Fermented Vegetables

Currently, there is increasing interest in the commercial utilization of probiotics isolated from traditional fermented food products. Therefore, this study aimed to investigate the probiotic potential of Lactiplantibacillus plantarum (L. plantarum) Z22 isolated from naturally fermented mustard. The results suggest that L. plantarum Z22 exhibits good adhesion ability, antibacterial activity, safety, and tolerance to acidic conditions and bile salts. We further determined the anti-inflammatory mechanism and properties of L. plantarum Z22 and found that L. plantarum Z22 could significantly reduce the secretion of pro-inflammatory cytokines, including interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and the expression of the pro-inflammatory mediator cyclooxygenase-2 (COX-2) protein in LPS-induced RAW 264.7 cells. In addition, L. plantarum Z22 also effectively inhibited the signaling pathways of nuclear factor κB (NF-κB) and mitogen-activated protein kinases (MAPKs). This effect can be attributed to a decrease in the levels of reactive oxygen species (ROS) and increased heme oxygenase-1 (HO-1) expression. Moreover, whole-genome sequencing revealed that L. plantarum Z22 contains gene-encoding proteins with anti-inflammatory functions, such as beta-glucosidase (BGL) and pyruvate kinase (PK), as well as antioxidant functions, including thioredoxin reductase (TrxR), tyrosine-protein phosphatase, and ATP-dependent intracellular proteases ClpP. In summary, these results indicated that L. plantarum Z22 can serve as a potential candidate probiotic for use in fermented foods such as yogurt (starter cultures), providing a promising strategy for the development of functional foods to prevent chronic diseases.

Notoginsenoside R1 Attenuates Cisplatin-Induced Ototoxicity by Inducing Heme Oxygenase-1 Expression and Suppressing Oxidative Stress

Cisplatin-induced ototoxicity occurs in approximately half of patients treated with cisplatin, and pediatric patients are more likely to be affected than adults. The oxidative stress elicited by cisplatin is a key contributor to the pathogenesis of ototoxicity. Notoginsenoside R1 (NGR1), the main bioactive compound of Panax notoginseng saponins, has antioxidant and antiapoptotic effects. This study investigated the ability of NGR1 to protect against cisplatin-induced damage in auditory HEI-OC1 cells and neonatal murine cochlear explants. The viability of HEI-OC1 cells treated with NGR1 and cisplatin was greater than that of cells treated with cisplatin alone. The results of Western blots and immunostaining for cleaved caspase-3 revealed that the level of cleaved caspase-3 in the cells treated with cisplatin was repressed by NGR1. NGR1 attenuated cisplatin-induced cytotoxicity in HEI-OC1 cells. Intracellular reactive oxygen species (ROS) were detected with a DCFDA assay and immunostaining for 4-HNE. The result revealed that its expression was induced by cisplatin and was significantly reduced by NGR1. Moreover, NGR1 can promote heme oxygenase-1 (HO-1) expression at both the mRNA and protein levels. ZNPPIX, an HO-1 inhibitor, was administered to cisplatin-treated cells to investigate the role of HO-1 in the protective effect of NGR1. The suppression of HO-1 activity by ZNPPIX markedly abolished the protective effect of NGR1 on cisplatin-treated cells. Therefore, NGR1 protects cells from cisplatin-induced damage by activating HO-1 and its antioxidative activity. In cochlear explants, NGR1 protects cochlear hair cells and attenuates cisplatin-induced ototoxicity by inhibiting ROS generation. In the group treated with cisplatin alone, prominent loss of outer hair cells and severe damage to the structure of the stereociliary bundles of inner and outer hair cells were observed. Compared with the group treated with cisplatin alone, less loss of outer hair cells (p = 0.009) and better preservation of the stereociliary bundles of hair cells were observed in the group treated with cisplatin and NGR1. In conclusion, these findings indicate that NGR1 can protect against cisplatin-induced ototoxicity by inducing HO-1 expression and suppressing oxidative stress.

Gene expression responses of CF airway epithelial cells exposed to elexacaftor/tezacaftor/ivacaftor (ETI) suggest benefits beyond improved CFTR channel function.

The combination of elexacaftor/tezacaftor/ivacaftor (ETI, Trikafta) reverses the primary defect in Cystic Fibrosis (CF) by improving CFTR mediated Cl- and HCO3- secretion by airway epithelial cells (AEC), leading to improved lung function and less frequent exacerbations and hospitalizations. However, studies have shown that CFTR modulators like ivacaftor, a component of ETI, has numerous effects on CF cells beyond improved CFTR channel function. Because little is known about the effect of ETI on CF AEC gene expression we exposed primary human AEC to ETI for 48 hours and interrogated the transcriptome by RNA-seq and qPCR. ETI increased CFTR Cl- secretion, and defensin gene expression (DEFB1) an observation consistent with reports of decreased bacterial burden in the lungs of people with CF (pwCF). ETI decreased MMP10 and MMP12 gene expression, suggesting that ETI may reduce proteolytic induced lung destruction in CF. ETI also reduced the expression of the stress response gene heme oxygenase (HMOX1). qPCR analysis confirmed DEFB1, HMOX1, MMP10 and MMP12 gene expression results observed by RNA-seq. Gene pathway analysis revealed that ETI decreased inflammatory signaling, cellular proliferation and MHC Class II antigen presentation. Collectively, these findings suggest that the clinical observation that ETI reduces lung infections in pwCF is related in part to drug induced increases in DEFB1, and that ETI may reduce lung damage by reducing MMP10 and MMP12 gene expression. Moreover, pathway analysis also identified several other genes responsible for the ETI induced reduction in inflammation observed in pwCF.

Mevastatin-Induced HO-1 Expression in Cardiac Fibroblasts: A Strategy to Combat Cardiovascular Inflammation and Fibrosis.

Mevastatin (MVS) is known for its anti-inflammatory effects, potentially achieved by upregulating heme oxygenase-1 (HO-1), an enzyme involved in cytoprotection against oxidative injury. Nonetheless, the specific processes by which MVS stimulates HO-1 expression in human cardiac fibroblasts (HCFs) are not yet fully understood. In this study, we found that MVS treatment increased HO-1 mRNA and protein levels in HCFs. This induction was inhibited by pretreatment with specific inhibitors of p38 MAPK, JNK1/2, and FoxO1, and by siRNAs targeting NOX2, p47phox, p38, JNK1, FoxO1, Keap1, and Nrf2. MVS also triggered ROS generation and activated JNK1/2 and p38 MAPK, both attenuated by NADPH oxidase or ROS inhibitors. Additionally, MVS promoted the phosphorylation of FoxO1 and Nrf2, which was suppressed by p38 MAPK or JNK1/2 inhibitor. Furthermore, MVS inhibited TNF-α-induced NF-κB activation and vascular cell adhesion molecule-1 (VCAM-1) expression via the HO-1/CO pathway in HCFs. In summary, the induction of HO-1 expression in HCFs by MVS is mediated through two primary signaling pathways: NADPH oxidase/ROS/p38 MAPK, and JNK1/2/FoxO1 and Nrf2. This research illuminates the underlying processes through which MVS exerts its anti-inflammatory effects by modulating HO-1 in cardiac fibroblasts.

Tumor microenvironment-based smart beacon drug delivery system for in situ visualization of tumor therapy

Real-time monitoring of the effectiveness of tumor-targeted drugs is crucial for assessing their impact. To address this need, we developed a beacon drug delivery system, MDB, which incorporates tumor targeting, anti-tumor effects, and near-infrared fluorescence emission for on-site visualization of tumor therapy. In non-cancerous cells, MDB remains inactive as a prodrug but is selectively activated within tumor cells when the borate ester group reacts with H2O2 in the tumor microenvironment (TME), releasing the beacon drug MDBRe. MDBRe can down-regulate the expression of the protein heme oxygenase 1 (HO-1), ultimately disrupting the mitochondrial energy supply system and leading to tumor cell death. It also emits near-infrared fluorescence for drug tracking under structured illumination microscopy (SIM). Both in vitro and in vivo experiments confirm the effective delivery of MDBRe by MDB to H2O2-enriched tumor tissues, resulting in a potent anti-tumor effect, visualization of drug distribution in tumors, and monitoring of therapy progress. In conclusion, our approach presents a novel method for targeted drug delivery to tumors and enables real-time visual monitoring of the treatment process.

Heme Oxygenase-1 Protected Against Severe Acute Pancreatitis by Inhibiting Inflammatory Response

Abstract Background Activation of NLPR3 inflammasome promotes the maturation and secretion of IL-1β and IL-18, leading to a series of inflammatory reactions, while inhibition of NLRP3 inflammasome alleviates the severity of Severe Acute Pancreatitis (SAP). An inducible enzyme responsible for heme decomposition, heme oxygenase-1 (HO-1), has anti-inflammatory, antioxidant, and anti-proliferative effects. HO-1 activity profoundly affects the host ability to forbear infection by reducing tissue damage or affecting resistance and increasing the capacity to pathogen load. We postulated that hemin, a strong HO-1 inducer, could decrease NLRP3 inflammasome activation, which would alleviate the severity of SAP and acute lung injury caused by pancreatitis. Methods By administering intraperitoneal injections of caerulein (Cae) and lipopolysaccharide (LPS), the SAP rat model was created. Then, the SAP rats were pretreated with Hemin or zinc protoporphyrin IX (Znpp, a HO-1 inhibitor) to stimulate or inhibit the HO-1 enzyme respectively, and the effects and mechanisms were investigated. Results The pancreas and lung tissue of the SAP rats suffered considerable pathological damage after Cae and LPS injection, with significant increases of amylase, lipase, IL-1β and IL-18 levels in the serum. Hemin pretreatment decreased IL-1β and IL-18 release in the serum and prevented pancreatic and pulmonary damage. Hemin dramatically reduced oxidative stress, downregulated the expression of NLRP3, ASC, and Caspase-1, and elevated HO-1 expression. On the contrary, there were no discernible changes between the SAP control and Znpp treated groups. Conclusion These results showed that hemin prevented Cae and LPS-induced lung and pancreatic injury through suppression of the inflammatory response. The impact of hemin on the activity of the NLRP3 inflammasome was depending critically on HO-1 activity. The protective role and mechanism HO-1 against the acute and severe inflammatory responses may provide a novel and effective therapeutic approach for SAP treatment.

Purple Butter Clam (Saxidomus Purpurata) as a Potential Functional Food Source for Obesity Treatment.

Saxidomus purpurata extract (SPE) is a highly consumable seafood worldwide with known health-related benefits. However, there are no reports of its' anti-obesity effect. This study explores the potential of SPE for anti-obesity effects by modulating adipogenesis and lipolysis. SPE reduced intracellular lipid and triglyceride accumulation while increasing free glycerol release in adipocytes. SPE inhibited lipogenesis protein expressions and increased the phosphorylation of hormone-sensitive lipase and Adenosine monophosphate-activated protein kinase (AMPK) to promote lipolysis. In addition, SPE suppressed adipogenesis by downregulating protein expression of key adipogenic markers, peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1) via Wnt/β-catenin signaling. SPE augmented the heme oxygenase-1 (HO-1) expression. Thus, pharmacological intervention with Zinc protoporphyrin (ZnPP-HO-1 antagonist) was employed to validate the HO-1 role. The presence of ZnPP increased the lipid accumulation and reduced the free glycerol release. At the molecular level, adipogenic transcription factors (PPARγ, C/EBPα, and SREBP1) expressions were restored in the presence of ZnPP. GC-MS analysis revealed that SPE was comprised of several fatty acids, contributing to its anti-obesity activity. SPE is an effective nutraceutical that can be used to reduce the progression of obesity. HO-1 expression during adipogenesis might be the mechanism of action for the anti-obesity effect of SPE.

Network pharmacology, molecular docking and experimental study on the mechanism of Curcumin's anti-ferroptosis in melanocytes

Ferroptosis is a form of regulated nonapoptotic cell death associated with iron-dependent lipid peroxidation, closely associated with Vitiligo. Although the impact of Curcumin (Cur), a polyphenolic compound derived from the plant Curcuma longa Linn, on vitiligo has been established, the specific role and potential mechanistic pathways through which Cur modulates ferroptosis in vitiligo remain elusive. In this study, the critical targets and potential mechanisms of Cur in treating vitiligo were predicted by network pharmacology and molecule docking. Then, the effects of Cur on Erastin-induced ferroptosis were investigated in melanocytes induced by Erastin in vitro. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of Cur acting on Vitiligo found that these intersection genes are associated with the vitiligo oxidative stress pathway, including nuclear factor erythroid 2-related factor 2(Nrf2)/Heme Oxygenase 1(HO-1) signaling pathway. Further molecular docking shows that Cur has a good binding effect with Nrf2(the binding energy of Cur and Nrf2 protein is −6 kcal/mol). Through the CCK8 assay, showed that 10 μM Cur treatment 24 h after Erastin significantly improved cell viability In vitro. Then we found that Erastin induced cell death, ROS production, the mitochondrial membrane potential(MMP) decreased, Superoxide dismutase (SOD) and Glutathione (GSH) levels reduced, Malonaldehyde (MDA) and iron ion accumulation in melanocytes. In addition, the expression of glutathione peroxidase 4(GPX4) mRNA and protein was inhibited, while the expression of acyl-CoA synthetase long-chain family member 4(ACSL4), Transferrin Receptor Protein 1(TFR1) mRNA and protein was increased. However, the damage induced by Erastin was significantly relieved by Cur and Fer-1 treatment. Mechanistically, Cur treatment significantly promoted nuclear translocation of transcriptional factor Nrf2 and HO-1 expression. Interestingly, pretreatment with ML385, a selective Nrf2 inhibitor, counteracted anti-ferroptosis effects induced by Cur treatment. Taken together, these results demonstrate that Cur inhibits ferroptosis by regulating the Nrf2/HO-1 pathway to protect melanocytes.

Circadian Clock Provides Beneficial Effects against Atherogenesis by Regulating Heme Oxygenase-1 Expression and Heme Synthesis

Circadian Clock Provides Beneficial Effects against Atherogenesis by Regulating Heme Oxygenase-1 Expression and Heme Synthesis

Agomelatine-loaded nanostructured lipid carriers alleviate neuropathic pain in rats by Nrf2/HO-1 signalling pathway.

Neuropathic pain arises from impairments or malfunctions within the nervous system, resulting in atypical transmission and interpretation of pain signals. In the present study, we examined the neuroprotective effects of agomelatine (AGM) and agomelatine-loaded nanostructured lipid carriers (AGM-NLCs) in neuropathic animal models induced by chronic constriction injury (CCI) of the sciatic nerve. Male Sprague Dawley rats were divided into seven experimental groups to compare the effects of AGM and AGM-NLCs, which were administered at 20 mg/kg for 14 consecutive days after CCI. Our finding demonstrated that CCI triggered the onset of analgesia in these animals, corroborated by mechanical allodynia and thermal hyperalgesia. Furthermore, CCI induced an elevation in inflammatory mediators such as interleukin (IL)-1β and inducible nitric oxide synthase (iNOS), and downregulated heme oxygenase-1 (HO-1) and nuclear factor E2-related factor (Nrf2). Treatment with AGM and AGM-NLCs reversed inflammatory cascades and elevated antioxidant enzyme levels, leading to a reduction in paw withdrawal latency and threshold in rats. To further investigate the effect of AGM and AGM-NLCs, all-trans retinoic acid (ATRA) was administered, which antagonizes Nrf2. ATRA substantially downregulated Nrf2 expression and exacerbated thermal hyperalgesia, whereas Nrf2 and HO-1 expressions were significantly upregulated after AGM-NLCs administration. Overall, the results demonstrated that AGM-NLCs offer promising antinociceptive and anti-inflammatory properties in alleviating neuropathic pain symptoms, which can be attributed to improved drug delivery and therapeutic outcomes compared with AGM alone.

Evaluating the Role of Nrf-2/HO-1 Pathway in Glioblastoma Treatment Efficacy: A Co-Culture Study

Objective: Glioblastoma (GB) is a highly lethal form of brain tumor. Although standard therapy appears to be effective, the survival time is quite short, and the recurrence rate is high. Bortezomib (BTZ), is a proteasome inhibitor, used in GB therapies and resulted in serious off-target effects. Carfilzomib (CFZ), is an alternative for BTZ, has known with nonserious off-target effects. This study aimed to examine the potential off-target effects caused by BTZ and CFZ in terms of the therapy related activation of antioxidant mechanisms regarding to Nuclear factor (erythroid-derived 2)-like 2 (Nrf-2)/Heme Oxygenase-1 (HO-1)-dependent response. Methods: GB cells were co-cultured with heathy astrocyte (HA) cells to mimic the tumor microenvironment in some extent. Cell viability was determined following ionizing radiation (IR), temozolomide (TMZ), BTZ and CFZ alone and in combination. Nrf-2 and HO-1 protein expressions were analyzed by western blotting assay. Results: Co-culture results showed that the GB cells in the BTZ-treated groups expressed higher levels of Nrf-2 and HO-1 than in the CFZtreated groups. In the HAs, the group treated with CFZ showed higher Nrf-2 expression than the group treated with BTZ alone, while the same groups in combination with TMZ&IR showed exactly opposite results. HO-1 expression was also not seen in any of the HA groups. Conclusion: The significant increase in Nrf-2 levels in the CFZ-treated group in the HAs could also be interpreted as CFZ promoting the defence of healthy cells against therapy-induced stress conditions. Although further studies are needed, these preliminary results show that the evaluation of CFZ as a second-line therapy could be a milestone for the treatment of GB.

Inhibition of calpain reduces oxidative stress and attenuates pyroptosis and ferroptosis in Clostridium perfringens Beta-1 toxin-induced macrophages

Clostridium perfringens Beta-1 toxin (CPB1) is a lethal toxin, which can lead to necrotic enteritis, but the pathological mechanism has not been elucidated. We investigated whether reactive oxygen species (ROS) participated in CPB1-induced pyroptosis and ferroptosis, and investigated the effects of calpain on CPB1-induced oxidative stress and inflammation. Scavenging ROS by N-acetyl cysteine (NAC) led to the reduction of ROS, inhibited the death of macrophages, cytoplasmic swelling and membrane rupture, the expression of pyroptosis-related proteins and proinflammatory factor, while increased the expression of anti-inflammatory factors in cells treated with rCPB1. Adenosine triphosphate (ATP) synthase, H+ transporting, mitochondrial F1 complex, alpha subunit 1 (ATP5A1) was identified specifically interact with rCPB1. Silencing ATP5A1 inhibited accumulation of ATP and ROS, leaded to less cytoplasmic swelling and membrane rupture, attenuated pyroptosis and inflammation in rCPB1-treated cells. We also found that rCPB1 induces ferroptosis in macrophages, and the level of ferroptosis was similar with H2O2. Of note, H2O2 is a major ROS source, indicated that ROS production may play a major role in the regulation of ferroptosis in macrophages treated with rCPB1. This finding was further corroborated in rCPB1- induced human acute monocytic leukemia cells, which were treated with NAC. In addition, the inhibition of ferroptosis using liproxstatin-1 inhibited the shriveled mitochondrial morphology, increased the expression of glutathione peroxidase 4, nicotinamide adenine dinucleotide (phosphate) hydrogen: quinone oxidoreductase 1 and cysteine/glutamic acid reverse transport solute carrier family 7 members 11, decreased the expression of heme oxygenase 1, nuclear receptor coactivator 4 and transferrin receptor proteins, reduced malondialdehyde and lipid peroxidation levels, and increased intracellular L-glutathione levels in cells treated with rCPB1. Furthermore, calpain inhibitor PD151746 was used to investigate how pyroptosis and ferroptosis were involved simultaneously in rCPB1-treated macrophages. We showed that PD151746 inhibited ATP and ROS production, reversed the representative pyroptosis/ferroptosis indicators and subsequently reduced inflammation. The above findings indicate that rCPB1 might lead to macrophage pyroptosis and ferroptosis through the large and sustained increase in intracellular calpain and oxidative stress, further lead to inflammation.

GBT1118, a Voxelotor Analog, Ameliorates Hepatopathy in Sickle Cell Disease.

Background and Objectives: In sickle cell disease (SCD), hepatopathy is a cumulative consequence of ischemia/reperfusion (I/R) injury from a vaso-occlusive crisis, tissue inflammation, and iron overload due to blood transfusion. Hepatopathy is a major contributing factor of shortened life span in SCD patients. We hypothesized that the voxelotor, a hemoglobin allosteric modifier, ameliorates sickle hepatopathy. Materials and Methods: Townes SCD mice and their controls were treated with either chow containing GBT1118, a voxelotor analog, or normal chow. We evaluated inflammation, fibrosis, apoptosis and ferroptosis in their livers using qPCR, ELISA, histology, and immunohistochemistry. Results: GBT1118 treatment resulted in reduced hemolysis, iron overload and inflammation in the liver of SCD mice. There were significant reductions in the liver enzyme levels and bile acids. Furthermore, GBT1118-treated mice exhibited reduced apoptosis, necrosis, and fibrosis. Increased ferroptosis as evident from elevated 4-hydroxynonenal (4-HNE) staining, malondialdehyde (MDA) levels, and expression of Ptgs2 and Slc7a11 mRNAs, were also significantly reduced after GBT1118 treatment. To explain the increased ferroptosis, we evaluated iron homeostasis markers in livers. SCD mice showed decreased expression of heme oxygenase-1, ferritin, hepcidin, and ferroportin mRNA levels. GBT1118 treatment significantly increased expressions of these genes. Conclusions: Our results suggest GBT1118 treatment in SCD confers the amelioration of sickle hepatopathy by reducing inflammation, fibrosis, apoptosis, iron overload and ferroptosis.

The Nrf2-HO-1 system and inflammaging.

Nrf2 is a master transcriptional regulator of a number of genes involved in the adaptive response to oxidative stress. Among the genes upregulated by Nrf2, heme oxygenase-1 (HO-1) has received significant attention, given that the products of HO-1-induced heme catabolism have well established antioxidant and anti-inflammatory properties. This is evidenced in numerous models of inflammatory and autoimmune disease whereby induction of HO-1 expression or administration of tolerable amounts of HO-1 reaction products can ameliorate disease symptoms. Unsurprisingly, Nrf2 and HO-1 are now considered viable drug targets for a number of conditions. In recent years, the term 'inflammaging' has been used to describe the low-grade chronic inflammation observed in aging/aged cells. Increased oxidative stress is also a key factor associated with aging and there is convincing evidence that Nrf2, not only declines with age, but that Nrf2 and HO-1 can reduce cellular senescence and the senescence-associated secretory phenotype (SASP) which is now considered an underlying driver of age-related inflammatory disease. In this review, we describe the role of oxidative stress in 'inflammaging' and highlight the potential anti-aging properties of the Nrf2-HO-1 system. We also highlight established and newly emerging Nrf2 activators and their therapeutic application in age-related disease.