Evaluation of the anticancer effects exerted by 5-fluorouracil and heme oxygenase-1 inhibitor hybrids in HTC116 colorectal cancer cells.

Colon cancer remains a clinical challenge in industrialised countries. Its treatment with 5-Flurouracil (5-FU) develops many side effects and resistance. Thus, several strategies have been undertaken so far, including the use of drug cocktails and polypharmacology. Heme oxygenase-1 (HO-1) is an emerging molecular target in the treatment of various cancers. We recently demonstrated that a combination of HO-1 inhibitors with 5-FU and the corresponding hybrids SI1/17, SI1/20, and SI1/22, possessed anticancer activity against prostate and lung cancer cells. In this work, we evaluated these hybrids in a model of colon cancer and found that SI1/22 and the respective combo have greater potency than 5-FU. Particularly, compounds inhibit HO-1 activity in cell lysates, increase ROS and the expression of HO-1, SOD, and Nrf2. Moreover, we observed a decrease of pro-caspase and an increase in cleaved PARP-1 and p62, suggesting apoptotic and autophagic cell death and potential application of these drugs as anticancer agents.

Icariin­curcumol promotes ferroptosis in prostate cancer cells through Nrf2/HO­1 signaling.

Ferroptosis is a form of regulatory cell death that relies on iron and reactive oxygen species (ROS) to inhibit tumors. The present study aimed to investigate whether icariin-curcumol could be a novel ferroptosis inducer in tumor inhibition. Various concentrations of icariin-curcumol were used to stimulate prostate cell lines (RWPE-2, PC-3, VCAP and DU145). Small interfering negative control (si-NC) and si-nuclear factor erythroid 2-related factor 2 (Nrf2) were used to transfect DU145 cells. Cell viability was determined by using cell counting kit-8. Ferroptosis-related factor levels were analyzed using western blotting and reverse transcription-quantitative PCR. Enzyme-linked immunosorbent assays were used to assess the ferrous (Fe2+), glutathione and malondialdehyde (MDA) content. The ROS fluorescence intensity was assessed using flow cytometry. DU145 cells were most sensitive to icariin-curcumol concentration. The Fe2+ content, ROS fluorescence intensity and MDA level gradually increased, while solute carrier family 7 member 11 (SLC7A11) level, glutathione peroxidase 4 (GPX4) level, GSH content, Nrf2 and heme oxygenase-1 (HO-1) decreased with icariin-curcumol in a dose-dependent manner. After si-Nrf2 was transfected, the cell proliferation ability, SLC7A11 and GPX4 levels declined compared with the si-NC group. In contrast to the control group, the icariin + curcumol group showed reductions in Nrf2 and HO-1 levels, cell proliferation, SLC7A11 and GPX4 levels, with an increase in Fe2+ content and ROS fluorescence intensity. Overexpression of Nrf2 reversed the regulation observed in the icariin + curcumol group. Icariin-curcumol induced ferroptosis in PCa cells, mechanistically by inhibiting the Nrf2/HO-1 signaling pathway. Icariin-curcumol could be used as a new type of ferroptosis inducer to treat PCa effectively.

Pyrogallol protects against influenza A virus-triggered lethal lung injury by activating the Nrf2-PPAR-γ-HO-1 signaling axis.

Pyrogallol, a natural polyphenol compound (1,2,3-trihydroxybenzene), has shown efficacy in the therapeutic treatment of disorders associated with inflammation. Nevertheless, the mechanisms underlying the protective properties of pyrogallol against influenza A virus infection are not yet established. We established in this study that pyrogallol effectively alleviated H1N1 influenza A virus-induced lung injury and reduced mortality. Treatment with pyrogallol was found to promote the expression and nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2) and peroxisome proliferator-activated receptor gamma (PPAR-γ). Notably, the activation of Nrf2 by pyrogallol was involved in elevating the expression of PPAR-γ, both of which act synergistically to enhance heme oxygenase-1 (HO-1) synthesis. Blocking HO-1 by zinc protoporphyrin (ZnPP) reduced the suppressive impact of pyrogallol on H1N1 virus-mediated aberrant retinoic acid-inducible gene-I-nuclear factor kappa B (RIG-I-NF-κB) signaling, which thus abolished the dampening effects of pyrogallol on excessive proinflammatory mediators and cell death (including apoptosis, necrosis, and ferroptosis). Furthermore, the HO-1-independent inactivation of janus kinase 1/signal transducers and activators of transcription (JAK1/STATs) and the HO-1-dependent RIG-I-augmented STAT1/2 activation were both abrogated by pyrogallol, resulting in suppression of the enhanced transcriptional activity of interferon-stimulated gene factor 3 (ISGF3) complexes, thus prominently inhibiting the amplification of the H1N1 virus-induced proinflammatory reaction and apoptosis in interferon-beta (IFN-ß)-sensitized cells. The study provides evidence that pyrogallol alleviates excessive proinflammatory responses and abnormal cell death via HO-1 induction, suggesting it could be a potential agent for treating influenza.

Production of biliverdin by biotransformation of exogenous heme using recombinant Pichia pastoris cells.

Biliverdin, a bile pigment hydrolyzed from heme by heme oxygenase (HO), serves multiple functions in the human body, including antioxidant, anti-inflammatory, and immune response inhibitory activities. Biliverdin has great potential as a clinical drug; however, no economic and efficient production method is available currently. Therefore, the production of biliverdin by the biotransformation of exogenous heme using recombinant HO-expressing yeast cells was studied in this research. First, the heme oxygenase-1 gene (HO1) encoding the inducible plastidic isozyme from Arabidopsis thaliana, with the plastid transport peptide sequence removed, was recombined into Pichia pastoris GS115 cells. This resulted in the construction of a recombinant P. pastoris GS115-HO1 strain that expressed active HO1 in the cytoplasm. After that, the concentration of the inducer methanol, the induction culture time, the pH of the medium, and the concentration of sorbitol supplied in the medium were optimized, resulting in a significant improvement in the yield of HO1. Subsequently, the whole cells of GS115-HO1 were employed as catalysts to convert heme chloride (hemin) into biliverdin. The results showed that the yield of biliverdin was 132 mg/L when hemin was added to the culture of GS115-HO1 and incubated for 4 h at 30 °C. The findings of this study have laid a good foundation for future applications of this method for the economical production of biliverdin.

[Value of constructing a non-invasive diagnostic model based on serum heme oxygenase-1 and glucose regulatory protein 78 for non-alcoholic fatty liver disease].

Objective: To analyze the clinical application value of serum heme oxygenase (HO)-1expression level in non-alcoholic fatty liver disease (NAFLD) and, based on that, establish a diagnostic model combined with glucose regulatory protein 78 (GRP78) so as to clarify its diagnostic effectiveness and application value. Methods: A total of 210 NAFLD patients diagnosed by abdominal B-ultrasound and liver elastography were included, and at the same time, 170 healthy controls were enrolled. The general clinical data, peripheral blood cell counts, and biochemical indicators of the research subjects were collected. The expression levels of HO-1 and GRP78 were detected using an enzyme-linked immunosorbent assay. Multivariate analysis was used to screen independent risk factors for NAFLD. Visual output was performed through nomogram diagrams, and the diagnostic model was constructed. Receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis (DCA) were used to evaluate the diagnostic effectiveness of NAFLD. Measurement data were analyzed using a t-test or Mann-Whitney U rank sum test to detect data differences between groups. Enumeration data were analyzed using the Fisher's exact probability test or the Pearson χ(2) test. Results: Compared with the healthy control group, the white blood cell count, aspartate aminotransferase (AST), alanine aminotransferase, gamma-glutamyl transferase (GTT), fasting blood glucose (Glu), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), serum HO-1, and GRP78 levels were significantly increased in the NAFLD group patients (P < 0.05). Binary logistic analysis results showed that AST, TG, LDL-C, serum HO-1, and GRP78 were independent risk factors for NAFLD (P < 0.05). A nomogram clinical predictive model HGATL was established using HO-1 (H), GRP78 (G) combined with AST (A), TG (T), and LDL-C (L), with the formula P=-21.469+3.621×HO-1+0.116 ×GRP78+0.674×AST+6.250×TG+4.122 ×LDL-C. The results confirmed that the area under the ROC curve of the HGATL model was 0.965 8, with an optimal cutoff value of 81.69, a sensitivity of 87.06%, a specificity of 92.82%, a P < 0.05, and the diagnostic effectiveness significantly higher than that of a single indicator. The calibration curve and DCA both showed that the model had good diagnostic performance. Conclusion: The HGATL model can be used as a novel, non-invasive diagnosis model for NAFLD and has a positive application value in NAFLD diagnosis and therapeutic effect evaluation. Therefore, it should be explored and promoted in clinical applications.

Activation of heme oxygenase-1 by laminar shear stress ameliorates high glucose-induced endothelial cell and smooth muscle cell dysfunction.

High glucose (HG)-induced endothelial cell (EC) and smooth muscle cell (SMC) dysfunction is critical in diabetes-associated atherosclerosis. However, the roles of heme oxygenase-1 (HO-1), a stress-response protein, in hemodynamic force-generated shear stress and HG-induced metabolic stress remain unclear. This investigation examined the cellular effects and mechanisms of HO-1 under physiologically high shear stress (HSS) in HG-treated ECs and adjacent SMCs. We found that exposure of human aortic ECs to HSS significantly increased HO-1 expression; however, this upregulation appeared to be independent of adenosine monophosphate-activated protein kinase, a regulator of HO-1. Furthermore, HSS inhibited the expression of HG-induced intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and reactive oxygen species (ROS) production in ECs. In an EC/SMC co-culture, compared with static conditions, subjecting ECs close to SMCs to HSS and HG significantly suppressed SMC proliferation while increasing the expression of physiological contractile phenotype markers, such as α-smooth muscle actin and serum response factor. Moreover, HSS and HG decreased the expression of vimentin, an atherogenic synthetic phenotypic marker, in SMCs. Transfecting ECs with HO-1-specific small interfering (si)RNA reversed HSS inhibition on HG-induced inflammation and ROS production in ECs. Similarly, reversed HSS inhibition on HG-induced proliferation and synthetic phenotype formation were observed in co-cultured SMCs. Our findings provide insights into the mechanisms underlying EC-SMC interplay during HG-induced metabolic stress. Strategies to promote HSS in the vessel wall, such as continuous exercise, or the development of HO-1 analogs and mimics of the HSS effect, could provide an effective approach for preventing and treating diabetes-related atherosclerotic vascular complications.

[Research progress on the mechanism of action of heme oxygenase-1 regulating ferroptosis in non-alcoholic fatty liver disease].

Non-alcoholic fatty liver disease (NAFLD) has gradually become the most prevalent chronic liver disease in the world, but its pathogenesis has not been fully elucidated. Ferroptosis is a novel type of programmed cell death caused by iron-dependent lipid peroxidation. Heme oxygenase-1 is a recognized antioxidant enzyme and an important regulatory factor in ferroptosis that modulates ferroptosis through various pathways and, in turn, regulates NAFLD. This paper reviews the regulatory mechanism of heme oxygenase-1 on NAFLD in ferroptosis pathway, with a view to clarifying the occurrence and development mechanisms of NAFLD and providing new vision and targets for its prevention and treatment.

LncRNA HMOX1 alleviates renal ischemia-reperfusion-induced ferroptotic injury via the miR-3587/HMOX1 axis.

Emerging evidence suggests that long non-coding RNAs (lncRNAs) play significant roles in renal ischemia reperfusion (RIR) injury. However, the specific mechanisms by which lncRNAs regulate ferroptosis in renal tubular epithelial cells remain largely unknown. The objective of this study was to investigate the biological function of lncRNA heme oxygenase 1 (lnc-HMOX1) in RIR and its potential molecular mechanism. Our findings demonstrated that the expression of HMOX1-related lnc-HMOX1 was reduced in renal tubular epithelial cells treated with hypoxia-reoxygenation (HR). Furthermore, the over-expression of lnc-HMOX1 mitigated ferroptotic injury in renal tubular epithelial cells in vivo and in vitro. Mechanistically, lnc-HMOX1, as a competitive endogenous RNA (ceRNA), promoted the expression of HMOX1 by sponging miR-3587. Furthermore, the inhibition of HMOX1 effectively impeded the aforementioned effects exerted by lnc-HMOX1. Ultimately, the inhibitory or mimic action of miR-3587 reversed the promoting or refraining influence of silenced or over-expressed lnc-HMOX1 on ferroptotic injury during HR. In summary, our findings contribute to a comprehensive comprehension of the mechanism underlying ferroptotic injury mediated by lnc-HMOX1 during RIR. Significantly, we identified a novel lnc-HMOX1-miR-3587-HMOX1 axis, which holds promise as a potential therapeutic target for RIR injury.

Craniofacial anomalies in schizophrenia-relevant GFAP.HMOX10-12m mice.

Subtle craniofacial dysmorphology has been reported in schizophrenia patients. This dysmorphology includes midline facial elongation, frontonasal anomalies and a sexually dimorphic deviation from normal directional asymmetry of the face, with male patients showing reduced and female patients showing enhanced facial asymmetry relative to healthy control subjects. GFAP.HMOX10-12m transgenic mice (Mus musculus) that overexpress heme oxygenase-1 in astrocytes recapitulate many schizophrenia-relevant neurochemical, neuropathological and behavioral features. As morphogenesis of the brain, skull and face are highly interrelated, we hypothesized that GFAP.HMOX10-12m mice may exhibit craniofacial anomalies similar to those reported in persons with schizophrenia. We examined craniofacial anatomy in male GFAP.HMOX10-12m mice and wild-type control mice at the early adulthood age of 6-8 months. We used computer vision techniques for the extraction and analysis of mouse head shape parameters from systematically acquired 2D digital images, and confirmed our results with landmark-based geometric morphometrics. We performed skull bone morphometry using digital calipers to take linear distance measurements between known landmarks. Relative to controls, adult male GFAP.HMOX10-12m mice manifested craniofacial dysmorphology including elongation of the nasal bones, alteration of head shape anisotropy and reduction of directional asymmetry in facial shape features. These findings demonstrate that GFAP.HMOX10-12m mice exhibit craniofacial anomalies resembling those described in schizophrenia patients, implicating heme oxygenase-1 in their development. As a preclinical mouse model, GFAP.HMOX10-12m mice provide a novel opportunity for the study of the etiopathogenesis of craniofacial and other anomalies in schizophrenia and related disorders.

Promotion of 14-3-3ζ/Heme Oxygenase-1 Axis on Endotoxin-Induced Uveitis and Microglia Ferroptosis in Mice.

PURPOSE: Uveitis is a common, sight-threatening inflammatory ocular disease and is the main cause of blindness, which is caused by autoimmune response, infection, and injury. The contribution of 14-3-3ζ in uveitis remains obscure. This study aims to investigate the role of 14-3-3ζ in regulating ferroptosis in retinal inflammation and its contribution to uveitis. METHODS: A lipopolysaccharide (LPS)-induced uveitis mouse model and BV-2 cell line were used to examine the effect of LPS stimulation on the expression of 14-3-3ζ and ferroptosis in microglia. The expression of heme oxygenase-1 (HO-1) was also analyzed to understand its role in promoting microglial ferroptosis. RESULTS: We found that LPS stimulation increased the expression of 14-3-3ζ and promoted ferroptosis in microglia. Additionally, 14-3-3ζ was found to promote microglial ferroptosis by stabilizing the expression of HO-1. These findings suggest that the 14-3-3ζ/HO-1 axis plays a crucial role in promoting microglial ferroptosis in retinal inflammation. CONCLUSION: The study provides valuable insights into the mechanisms underlying uveitis and highlights the potential of the 14-3-3ζ/HO-1 axis as a therapeutic target for the disease. Further research in this area could lead to the development of preventive and therapeutic strategies for uveitis.

Absence of Heme Oxygenase-1 Affects Trophoblastic Spheroid Implantation and Provokes Dysregulation of Stress and Angiogenesis Gene Expression in the Uterus.

The enzyme heme oxygenase-1 (HO-1) is pivotal in reproductive processes, particularly in placental and vascular development. This study investigated the role of HO-1 and its byproduct, carbon monoxide (CO), in trophoblastic spheroid implantation. In order to deepen our understanding of the role of HO-1 during implantation, we conducted in vivo experiments on virgin and pregnant mice, aiming to unravel the cellular and molecular mechanisms. Using siRNA, HO-1 was knocked down in JEG-3 and BeWo cells and trophoblastic spheroids were generated with or without CO treatment. Adhesion assays were performed after transferring the spheroids to RL-95 endometrial epithelial cell layers. Additionally, angiogenesis, stress, and toxicity RT2-Profiler™ PCR SuperArray and PCR analyses were performed in uterine murine samples. HO-1 knockdown by siRNA impeded implantation in the 3D culture model, but this effect could be reversed by CO. Uteruses from virgin Hmox1-/- females exhibited altered expression of angiogenesis and stress markers. Furthermore, there was a distinct expression pattern of cytokines and chemokines in uteruses from gestation day 14 in Hmox1-/- females compared to Hmox1+/+ females. This study strongly supports the essential role of HO-1 during implantation. Moreover, CO appears to have the potential to compensate for the lack of HO-1 during the spheroid attachment process. The absence of HO-1 results in dysregulation of angiogenesis and stress-related genes in the uterus, possibly contributing to implantation failure.

Serum heme oxygenase-1 level predicts clinical outcome after acute ischemic stroke.

AIMS: The relationship between heme oxygenase-1 (HO-1) and human ischemic stroke outcome remains unclear, which was investigated in this study. METHODS: Acute ischemic stroke patients admitted within 24 h were enrolled. Serum HO-1 levels at baseline were measured via ELISA. Poor 3-month functional outcome was defined as modified Rankin Scale (mRS) score 3-6. Multivariable-adjusted binary logistic regression and restricted cubic spline models were employed to examine association between serum HO-1 and functional outcome. HO-1's additive prognostic utility was assessed by net reclassification index (NRI) and integrated discrimination improvement (IDI). RESULTS: Of 194 eligible patients, 79 (40.7%) developed poor functional outcomes at 3-month follow-up. The highest quartile of serum HO-1 was independently associated with a lower risk of poor functional outcome (adjusted OR 0.13, 95% CI 0.04-0.45; p = 0.001) compared with the lowest HO-1 category. The relationship between higher HO-1 levels and reduced risk of poor functional outcome was linear and dose responsive (p = 0.002 for linearity). Incorporating HO-1 into the analysis with conventional factors significantly improved reclassification for poor functional outcomes (NRI = 41.2%, p = 0.004; IDI = 5.0%, p = 0.004). CONCLUSIONS: Elevated serum HO-1 levels at baseline were independently associated with improved 3-month functional outcomes post-ischemic stroke. Serum HO-1 measurement may enhance outcome prediction beyond conventional clinical factors.

Deficiency of heme oxygenase 1a causes detrimental effects on cardiac function.

Humans lacking heme oxygenase 1 (HMOX1) display growth retardation, haemolytic anaemia, and vulnerability to stress; however, cardiac function remains unclear. We aimed to explore the cardiac function of zebrafish lacking hmox1a at baseline and in response to stress. We generated zebrafish hmox1a mutants using CRISPR/Cas9 genome editing technology. Deletion of hmox1a increases cardiac output and further induces hypertrophy in adults. Adults lacking hmox1a develop myocardial interstitial fibrosis, restrain cardiomyocyte proliferation and downregulate renal haemoglobin and cardiac antioxidative genes. Larvae lacking hmox1a fail to respond to hypoxia, whereas adults are insensitive to isoproterenol stimulation in the heart, suggesting that hmox1a is necessary for cardiac response to stress. Haplodeficiency of hmox1a stimulates non-mitochondrial respiration and cardiac cell proliferation, increases cardiac output in larvae in response to hypoxia, and deteriorates cardiac function and structure in adults upon isoproterenol treatment. Intriguingly, haplodeficiency of hmox1a upregulates cardiac hmox1a and hmox1b in response to isoproterenol. Collectively, deletion of hmox1a results in cardiac remodelling and abrogates cardiac response to hypoxia and isoproterenol. Haplodeficiency of hmox1a aggravates cardiac response to the stress, which could be associated with the upregulation of hmox1a and hmox1b. Our data suggests that HMOX1 homeostasis is essential for maintaining cardiac function and promoting cardioprotective effects.

Resolvins protect against diabetes-induced colonic oxidative stress, barrier dysfunction, and associated diarrhea via the HO-1 pathway.

Diabetes is associated with increased oxidative stress, leading to altered tight junction formation and increased apoptosis in colonic epithelial cells. These changes may lead to intestinal barrier dysfunction and corresponding gastrointestinal symptoms in patients with diabetes, including diarrhea. The aim of this study was to characterize the effect and mechanism of Resolvin D1 (RvD1) on diabetes-induced oxidative stress and barrier disruption in the colon. Mice with streptozotocin-induced diabetes were treated with RvD1 for 2 weeks, then evaluated for stool frequency, stool water content, gut permeability, and colonic transepithelial electrical resistance as well as production of reactive oxygen species (ROS), apoptosis, and expression of tight junction proteins Zonula Occludens 1 (ZO-1) and occludin. The same parameters were assessed in human colonoid cultures subjected to elevated glucose. We found that RvD1 treatment did not affect blood glucose, but normalized stool water content and prevented intestinal barrier dysfunction, epithelial oxidative stress, and apoptosis. RvD1 also restored ZO-1 and occludin expression in diabetic mice. RvD1 treatment increased phosphorylation of Akt and was accompanied by a 3.5-fold increase in heme oxygenase-1 (HO-1) expression in the epithelial cells. The protective effects of RvD1 were blocked by ZnPP, a competitive inhibitor of HO-1. Similar findings were observed in RvD1-treated human colonoid cultures subjected to elevated glucose. In conclusion, Oxidative stress in diabetes results in mucosal barrier dysfunction, contributing to the development of diabetic diarrhea. Resolvins prevent ROS-mediated mucosal injury and protect gut barrier function by intracellular PI3K/Akt activation and subsequent HO-1 upregulation in intestinal epithelial cells. These actions result in normalizing stool frequency and stool water content in diabetic mice, suggesting that resolvins may be useful in the treatment of diabetic diarrhea.

Cobalt protoporphyrin promotes heme oxygenase 1 expression and ameliorates cardiac dysfunction in long-term fasting mice.

BACKGROUND: The association between malnutrition and cardiac dysfunction has been reported. Heme oxygenase (HO)-1 played protective roles in the animals functioning as a myocardial infarction, heart failure, or cardiomyopathy model. We hypothesized that the administration of HO-1 inducer, cobalt protoporphyrin (CoPP) reduces oxidative stress and ameliorates cardiac systolic dysfunction in long-term fasting mice. METHODS: C57BL/6 J mice were classified into three groups: fed mice (fed group), 48-h fasting mice with a single intraperitoneal injection of the corresponding vehicle (fasting group), and 48-h fasting mice with a single intraperitoneal injection of 5 mg/kg CoPP (CoPP group). RESULTS: The fasting group showed a significant increase in heme and 4-hydroxy-2-nonenal (4HNE) protein in the heart tissue, and reduced left ventricular ejection fraction (LVEF) when compared with the fed group. The CoPP group showed significantly increased protein levels of nuclear factor-erythroid 2-related factor 2 and HO-1, and increased mRNA expression levels of HO-1, peroxisome proliferator-activated receptor gamma coactivator 1-alpha, forkhead box protein O1, sirtuin-1, cyclooxygenase 2, and superoxide dismutase 2, and reduced levels of heme and 4HNE protein when compared with the fasting group. LVEF were significantly higher in the CoPP group than in the fasting group. CONCLUSIONS: Administration of CoPP reduced heme accumulation and oxidative stress, and ameliorated cardiac systolic dysfunction in long-term fasting mice. This study suggests that heme accumulation may be associated with impaired cardiac function induced by long-term fasting and that HO-1 may be a key factor or therapeutic target.

Antioxidant Enzymes in Cancer Cells: Their Role in Photodynamic Therapy Resistance and Potential as Targets for Improved Treatment Outcomes.

Photodynamic therapy (PDT) is a selective tumor treatment that consists of a photosensitive compound-a photosensitizer (PS), oxygen, and visible light. Although each component has no cytotoxic properties, their simultaneous use initiates photodynamic reactions (PDRs) and sequentially generates reactive oxygen species (ROS) and/or free radicals as cytotoxic mediators, leading to PDT-induced cell death. Nevertheless, tumor cells develop various cytoprotective mechanisms against PDT, particularly the adaptive mechanism of antioxidant status. This review integrates an in-depth analysis of the cytoprotective mechanism of detoxifying ROS enzymes that interfere with PDT-induced cell death, including superoxide dismutase (SOD), catalase, glutathione redox cycle, and heme oxygenase-1 (HO-1). Furthermore, this review includes the use of antioxidant enzymes inhibitors as a strategy in order to diminish the antioxidant activities of tumor cells and to improve the effectiveness of PDT. Conclusively, PDT is an effective tumor treatment of which its effectiveness can be improved when combined with a specific antioxidant inhibitor.

Assessing the Impact of Influenza Vaccination Timing on Experimental Arthritis: Effects on Disease Progression and Inflammatory Biomarkers.

Numerous studies have indicated a link between vaccines and the exacerbation of autoimmune diseases including rheumatoid arthritis (RA). However, there is no consensus in clinical practice regarding the optimal timing of immunization. Therefore, this study aimed to investigate the impact of the 3Fluart influenza vaccine on the complete Freund's adjuvant (CFA)-induced chronic arthritis rat model and to identify new biomarkers with clinical utility. CFA was injected into the plantar surface of one hind paw and the root of the tail on day 0, and the tail root injection was repeated on day 1. Flu vaccination was performed on day 1 or 7. Paw volume was measured by plethysmometry, mechanonociceptive threshold by dynamic plantar aesthesiometry, neutrophil myeloperoxidase (MPO) activity, and vascular leakage using in vivo optical imaging throughout the 21-day experiment. Inflammatory markers were determined by Western blot and histopathology. CFA-induced swelling, an increase in MPO activity, plasma extravasation in the tibiotarsal joint. Mechanical hyperalgesia of the hind paw was observed 3 days after the injection, which gradually decreased. Co-administration of the flu vaccine on day 7 but not on day 1 resulted in significantly increased heme oxygenase 1 (HO-1) expression. The influenza vaccination appears to have a limited impact on the progression and severity of the inflammatory response and associated pain. Nevertheless, delayed vaccination could alter the disease activity, as indicated by the findings from assessments of edema and inflammatory biomarkers. HO-1 may serve as a potential marker for the severity of inflammation, particularly in the case of delayed vaccination. However, further investigation is needed to fully understand the regulation and role of HO-1, a task that falls outside the scope of the current study.

Knockdown of FOXO4 protects against OGD/R­induced cerebral microvascular endothelial cell injury and regulates the AMPK/Nrf2/HO­1 pathway through transcriptional activation of CTRP6.

Cerebral ischemia is a type of cerebrovascular disease with high disability and mortality rates. The expression of forkhead box protein O4 (FOXO4) in the brain is increased following traumatic brain injury. To the best of our knowledge, however, the role of FOXO4 as well as its mechanism in cerebral ischemia has not been reported so far. For the establishment of an in vitro cellular injury model, human brain microvascular endothelial HCMEC/D3 cells were induced by oxygen-glucose deprivation/reoxygenation (OGD/R). mRNA and protein expressions of FOXO4 and C1q/tumor necrosis factor-related protein 6 (CTRP6) in OGD/R-induced HCMEC/D3 cells were detected by reverse transcription-quantitative (RT-q)PCR and western blotting. The transfection efficacy of small interfering (si)- and overexpression (Ov)-FOXO4 and si-CTRP6 was assessed using RT-qPCR and western blotting. Cell Counting Kit-8 and TUNEL assay were used to assess viability and apoptosis of HCMEC/D3 cells induced by OGD/R, respectively. A FITC-Dextran assay kit was applied to determine endothelial permeability and immunofluorescence assay was used for the measurement of the tight junction protein zonula occludens-1. The levels of oxidative stress markers and inflammatory cytokines were assessed with corresponding assay kits. The binding sites of transcription factor, FOXO4 and CTRP6 promoter were predicted using HDOCK SERVER. Luciferase reporter assay was used to detect the activity of the CTRP6 promoter while chromatin immunoprecipitation assay was used to evaluate the binding ability of the FOXO4 and CTRP6 promoter. Western blotting was used for the detection of apoptosis- and AMPK/Nrf2/heme oxygenase-1 (HO-1) pathway-associated proteins, along with tight junction proteins. The expression of FOXO4 was increased in OGD/R-induced HCMEC/D3 cells. After interfering with FOXO4 in cells, the viability of the OGD/R-induced HCMEC/D3 cells was increased while apoptosis was decreased. Furthermore, FOXO4 interference improved cellular barrier dysfunction but inhibited oxidative stress and the inflammatory response in HCMEC/D3 cells induced by OGD/R. FOXO4 knockdown regulated CTRP6 transcription in HCMEC/D3 cells. Knockdown of FOXO4 regulated expression of CTRP6 and protected OGD/R-induced HCMEC/D3 cell injury via the AMPK/Nrf2/HO-1 pathway. The present study indicated that FOXO4 knockdown activated CTRP6 to protect against cerebral microvascular endothelial cell injury induced by OGD/R via the AMPK/Nrf2/HO-1 pathway.

Therapeutic Role of Chinese Medicine Targeting Nrf2/HO-1 Signaling Pathway in Myocardial Ischemia/Reperfusion Injury.

Acute myocardial infarction (AMI), characterized by high incidence and mortality rates, poses a significant public health threat. Reperfusion therapy, though the preferred treatment for AMI, often exacerbates cardiac damage, leading to myocardial ischemia/reperfusion injury (MI/RI). Consequently, the development of strategies to reduce MI/RI is an urgent priority in cardiovascular therapy. Chinese medicine, recognized for its multi-component, multi-pathway, and multi-target capabilities, provides a novel approach for alleviating MI/RI. A key area of interest is the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. This pathway is instrumental in regulating inflammatory responses, oxidative stress, apoptosis, endoplasmic reticulum stress, and ferroptosis in MI/RI. This paper presents a comprehensive overview of the Nrf2/HO-1 signaling pathway's structure and its influence on MI/RI. Additionally, it reviews the latest research on leveraging Chinese medicine to modulate the Nrf2/HO-1 pathway in MI/RI treatment.

Heme oxygenase-1 alleviates allergic airway inflammation by suppressing NF-κB-mediated pyroptosis of bronchial epithelial cells.

Allergic asthma development and pathogenesis are influenced by airway epithelial cells in response to allergens. Heme oxygenase-1 (HO-1), an inducible enzyme responsible for the breakdown of heme, has been considered an appealing target for the treatment of chronic inflammatory diseases. Herein, we report that alleviation of allergic airway inflammation by HO-1-mediated suppression of pyroptosis in airway epithelial cells (AECs). Using house dust mite (HDM)-induced asthma models of mice, we found increased gasdermin D (GSDMD) in the airway epithelium. In vivo administration of disulfiram, a specific inhibitor of pore formation by GSDMD, decreased thymic stromal lymphopoietin (TSLP) release, T helper type 2 immune response, alleviated airway inflammation, and reduced airway hyperresponsiveness (AHR). HO-1 induction by hemin administration reversed these phenotypes. In vitro studies revealed that HO-1 restrained GSDMD-mediated pyroptosis and cytokine TSLP release in AECs by binding Nuclear Factor-Kappa B (NF-κB) p65 RHD domain and thus controlling NF-κB-dependent pyroptosis. These data provide new therapeutic indications for purposing HO-1 to counteract inflammation, which contributes to allergic inflammation control.