Upregulation Of Heme Oxygenase-1 Research Articles

Highly Penetrable Drug-Loaded Nanomotors for Photothermal-Enhanced Ferroptosis Treatment of Tumor.

A kind of drug-loaded nanomotors with deep penetration was developed to improve the therapeutic effect of ferroptosis on tumor. The nanomotors were constructed by co-loading hemin and ferrocene (Fc) on the surface of bowl-shaped polydopamine (PDA) nanoparticles. The near-infrared response of PDA makes the nanomotor have high tumor penetration capability. In vitro experiments show that the nanomotors can exhibit good biocompatibility, high light to heat conversion efficiency, and deep tumor permeability. It is worth noting that under the catalysis of H2O2 overexpressed in the tumor microenvironment, the Fenton-like reagents hemin and Fc loaded on the nanomotors can increase the concentration of toxic •OH. Furthermore, hemin can consume glutathione in tumor cells and trigger the up-regulation of heme oxygenase-1, which can efficiently decompose hemin to Fe2+, thus producing the Fenton reaction and causing a ferroptosis effect. Notably, thanks to the photothermal effect of PDA, it can enhance the generation of reactive oxygen species and thus intervene in the Fenton reaction process, thereby enhancing the ferroptosis effect photothermally. In vivo antitumor results show that the drug-loaded nanomotors with high penetrability showed an effective antitumor therapeutic effect.

Clustered Cobalt Nanodots Initiate Ferroptosis by Upregulating Heme Oxygenase 1 for Radiotherapy Sensitization (Small 10/2023)

Radiotherapy Sensitization Enhancing the cellular radiosensitivity is instrumental for improving the efficacy of tumor radiotherapy. In article number 2206415, Junping Wang, Cheng Wang, and co-workers report a tumor-penetrating nanomaterial iCoDMSN constituted with dendritic mesoporous silica nanoparticles and iRGD peptide-conjugated [email protected] nanodots. By decreasing KEAP1 expression and upregulating nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase 1 (HMOX1), iCoDMSN expands the labile iron pool in cancer cells and initiates ferroptosis, whereby the nanomaterial sensitizes cancer cells to ionized radiation and eliminates the tumors combined with radiotherapy.

Shikonin and cisplatin synergistically overcome cisplatin resistance of ovarian cancer by inducing ferroptosis via upregulation of HMOX1 to promote Fe2+ accumulation

BackgroundCisplatin-based chemotherapy often results in ovarian cancer (OC) chemical resistance and treatment failure. The combination of natural compounds with platinum-based agents is a new strategy for overcoming cisplatin resistance. At present, the synergistic effects and mechanism of combination of shikonin and cisplatin to overcome cisplatin resistance in OC are still unknown. PurposeThis study was to evaluate the synergistic effects of shikonin and cisplatin on cisplatin-resistant OC cells and to assess the underlying molecular basis for these effects. MethodsCell counting kit-8 assay, colony-formation assay, proteomic analysis, reactive oxygen species (ROS) detection, lipid peroxidation (LPO) detection, Fe2+ detection, western blot, and quantitative real-time reverse transcription PCR (qRT-PCR) were performed to evaluate the effects of shikonin and cisplatin on cisplatin-resistant OC cells. Underlying mechanisms of action were investigated in vitro using small molecule inhibitors and siRNA. In vivo, the effect of shikonin and cisplatin combination on tumor growth in BALB/c nude mice was evaluated, with tumor immunohistochemical (IHC) staining performed to detect ferroptosis-related proteins. ResultsIn vitro, shikonin and cisplatin were shown to synergistically reduce the viability of cisplatin-resistant OC cells. Proteomic results demonstrated that the combination of the two drugs induced a ferroptotic process, as evidenced by increased levels of ROS, LPO, and Fe2+, with downregulation of glutathione peroxidase 4 (GPX4). Heme oxygenase 1 (HMOX1) inhibition and siRNA interference attenuated the combined effect of the two drugs on cell viability. Accumulation of Fe2+ was attenuated by siRNA interference of HMOX1. In vivo, combination treatment significantly inhibited the growth of subcutaneous tumors in BALB/c nude mice and increased the expression of ferroptosis-related proteins in tumor tissue. ConclusionWe report for the first time that the co-treatment of shikonin and cisplatin overcomes cisplatin resistance in OC through ferroptosis. Mechanistic analysis reveals the co-treatment induces ferroptosis through upregulation of HMOX1 that promotes Fe2+ accumulation.

Metal protoporphyrin‐induced self‐assembly nanoprobe enabling precise tracking and antioxidant protection of stem cells for ischemic stroke therapy

AbstractMesenchymal stem cell (MSC)‐based therapy has provided a promising strategy for the treatment of ischemic stroke, which is still restricted by the lack of long‐term cell tracking strategy as well as the poor survival rate of stem cells in ischemic region. Herein, a dual‐functional nanoprobe, cobalt protoporphyrin‐induced nano‐self‐assembly (CPSP), has been developed through a cobalt protoporphyrin IX (CoPP) aggregation‐induced self‐assembly strategy, which combines CoPP and superparamagnetic iron oxide (SPION) via a simple solvent evaporation‐driven method. Without any additional carrier materials, the obtained CPSP is featured with good biocompatibility and high proportions of active ingredients. The SPIONs in CPSPs form a cluster‐like structure, endowing this nano‐self‐assembly with excellent T2‐weighted magnetic resonance (MR) imaging performance. Furthermore, the CoPP released from CPSPs could effectively protect MSCs by upregulating heme oxygenase 1 (HO‐1) expression. The in vivo cell tracing capacity of CPSPs is confirmed by monitoring the migration of labeled MSCs with MR imaging in a middle cerebral artery occlusion mouse model. More importantly, the sustained release of CoPP from CPSPs improves the survival of transplanted MSCs and promotes neural repair and neurobehavioral recovery of ischemic mice. Overall, this work presents a novel dual‐functional nanoagent with an ingenious design for advancing MSC‐based therapy.

Fermented Aloe arborescens Miller Leaf Extract Suppresses Acute Alcoholic Liver Injury via Antioxidant and Anti-Inflammatory Effects in C57BL/6J Mice.

This study confirmed the change in functional composition and alcohol-induced acute liver injury in Aloe arborescens after fermentation. An acute liver injury was induced by administration of ethanol (3 g/kg/day) to C57BL/6J mice for 5 days. A fermented A. arborescens Miller leaf (FAAL) extract was orally administered 30 minutes before ethanol treatment. After fermentation, the emodin content was approximately 13 times higher than that of the raw material. FAAL extract significantly attenuated ethanol-induced aspartate aminotransferase, alanine aminotransferase, and triglyceride increases in serum and liver tissue. Histological analysis revealed that FAAL extract inhibits inflammatory cell infiltration and fat accumulation in liver tissues. The cytochrome P450 2E1, superoxide dismutase, and glutathione (GSH), which involved in alcohol-induced oxidative stress, were effectively regulated by FAAL extract in serum and liver tissues, except for GSH. FAAL also maintained the antioxidant defense system by upregulating heme oxygenase 1 and nuclear factor erythroid 2-related factor 2 protein expression. In addition, FAAL extract inhibited the decrease in alcohol dehydrogenase and aldehyde dehydrogenase activity, which promoted alcohol metabolism and prevented the activation of inflammatory response. Our results suggest that FAAL could be used as a potential therapeutic agent for ethanol-induced acute liver injury.

Pharmacology-based molecular docking of 4-methylcatechol and its role in RANKL-mediated ROS/Keap1/Nrf2 signalling axis and osteoclastogenesis

4-Methylcatechol (4-MC) is an agonist of various neurotrophic factors, which can upregulate the expression of Heme oxygenase 1 (HO-1) protein by activating nuclear factor erythroid 2-related factor 2 (Nrf2), thereby inhibiting oxidative stress-induced neural stem cell death. During RANKL-stimulated osteoclast differentiation, intracellular reactive oxygen species (ROS) levels were increased. Nonetheless, the effect of 4-MC on osteoclast formation and bone resorption function has not been researched. In this study, we investigated the effect of HO-1 upregulation by 4-MC on RANKL-induced osteoclastogenesis and explored the molecular mechanism of HO-1 upregulation by 4-MC. We found that the small molecule compound 4-MC could bind to Keap1 amino acid residue of glycine GLY 367, isoleucine ILE 559 and valine VAL 606, with a predicted binding energy of −4.99 kcal/mol. 4-MC was found to inhibit osteoclast differentiation in vitro by activating Nrf2 to scavenge ROS, inhibiting NF-κB phosphorylation, and alleviating osteoporosis in ovariectomized (OVX) mice. Taken together, 4-MC reduces ROS by inhibiting Keap1, thereby preventing OVX-induced bone loss.

Clustered Cobalt Nanodots Initiate Ferroptosis by Upregulating Heme Oxygenase 1 for Radiotherapy Sensitization.

High cobalt (Co) levels in tumors are associated with good clinical prognosis. An anticancer regimen that increases intratumoral Co through targeted nanomaterial delivery is proposed in this study. Bovine serum albumin and cobalt dichloride are applied to prepare cobaltous oxide nanodots using a facile biomineralization strategy. After iRGD peptide conjugation, the nanodots are loaded into dendritic mesoporous silica nanoparticles, generating a biocompatible product iCoDMSN. This nanocomposite accumulates in tumors after intravenous injection by deep tissue penetration and can be used for photoacoustic imaging. Proteomics research and molecular biology experiments reveal that iCoDMSN is a potent ferroptosis inducer in cancer cells. Mechanistically, iCoDMSNs upregulate heme oxygenase 1 (HMOX1), which increases transferrin receptors and reduces solute carrier family 40 member 1 (SLC40A1), resulting in Fe2+ accumulation and ferroptosis initiation. Furthermore, upregulated nuclear factor erythroid 2-related factor 2 (NRF2), arising from the reduction in Kelch-like ECH-associated protein 1 (KEAP1) expression, is responsible for HMOX1 enhancement after iCoDMSN treatment. Owing to intensified ferroptosis, iCoDMSN acts as an efficient radiotherapy enhancer to eliminate cancer cells in vitro and in vivo. This study demonstrates a versatile Co-based nanomaterial that primes ferroptosis by expanding the labile iron pool in cancer cells, providing a promising tumor radiotherapy sensitizer.

Pretreatment of human retinal pigment epithelial cells with sterculic acid forestalls fenretinide-induced apoptosis

The ratio of saturated to monounsaturated fatty acids, thought to play a critical role in many cellular functions, is regulated by stearoyl-CoA desaturase (SCD), a rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids. Previously, we observed a decrease in both SCD protein and enzymatic activity in apoptosis induced by fenretinide, a synthetic analog of retinoic acid, in the human retinal pigment epithelial (RPE) cell line ARPE-19. Here, we investigated the effect of pretreating ARPE-19 with sterculic acid, a cyclopropenoic fatty acid inhibitor of SCD, on preventing fenretinide-induced apoptosis, given the role of SCD in cell proliferation and apoptosis. We show that sterculic acid pretreatment prevents the effects of fenretinide-induced apoptosis shown by changes in cell morphology, viability, and caspase-3 activation. Analysis of endoplasmic reticulum (ER)-associated proteins shows that sterculic acid pretreatment reduced the fenretinide-induced upregulation of heme oxygenase-1, ATF3 and GADD153 expression that are in response to reactive oxygen species (ROS) generation. Sterculic acid is as effective as allopurinol in inhibition of xanthine oxidase (XDH), and this may play a role in reducing the potential role of XDH in fenretinide-induced ROS generation. Sterculic acid pretreatment also results in a reduction in SOD2 mRNA expression. Dihydroceramide accumulation, compared to ceramide, and ROS generation indicate that a ceramide-independent pathway mediates fenretinide-induced apoptosis, and ROS mediation is borne out by activation of the NF-κBp50 and NF-κBp65 downstream signaling cascade. Its prevention by sterculic acid pretreatment further indicates the latter’s antioxidant/anti-inflammatory effect. Taken together, our results suggest that sterculic acid pretreatment can mitigate ROS-mediated fenretinide-induced apoptosis. Thus, sterculic acid may serve as a potential antioxidant and therapeutic agent. These effects may be independent of its effects on SCD activity.

Hypoxia-Induced Oxidative Stress Promotes Proteasome Inhibitor Resistance Via Upregulation of Heme Oxygenase-1 in Multiple Myeloma

Background Multiple myeloma (MM) is a hematopoietic malignancy for which proteasome inhibitors have become available in recent years. However, many patients develop resistance to these drugs during treatment. Therefore, it is important to elucidate the mechanisms underlying resistance acquisition by proteasome inhibitors. Side population (SP) cells, which have a high drug efflux capacity, as well as hypoxic responses in the microenvironment, have both provided important insights into drug resistance in MM; however, little is known about the characteristics of SP cells in hypoxic microenvironments. Aim and Methods To find novel therapeutic target for drug resistant MM cells, the SP cells and non-SP cells of MM cell lines (RPMI-8226 and KMS-11) were sorted for normoxic and hypoxic cultures (1% O2) for 48 h, respectively, and cDNA microarray assays were performed on these samples. Then, we conducted functional analysis of hypoxia-SP specific genes. Results Our comprehensive gene expression analysis identified four coding genes (HMOX1, BACH2, DUX4, and RASGEF1B) and seven non-coding genes (TUSC8, LOC101928738, lnc-WRAP73-1, LINC-PINT, LINC01004, MIR146A, and lnc-FAM133B-1) that are specifically highly expressed in SP cells under hypoxic conditions. Among protein-coding genes, RT-qPCR showed very low expression of BACH2 and no expression of DUX4; we decided to investigate the function of HMOX1/heme oxygenase-1 (HO-1) in hypoxic environments. One of the functions of HO-1 is to protect cells from apoptosis induced by reactive oxygen species (ROS). We found a significant increase in ROS under hypoxic conditions compared with normoxic conditions in MM cells, including MM patient samples. HMOX1 knockdown significantly increased ROS levels under both normoxic and hypoxic conditions. These results suggest that hypoxic stress induced ROS and that HO-1 can neutralize hypoxia-induced ROS. The addition of PMA, a ROS inducer, significantly increased HMOX1/HO-1 in MM cells. Conversely, the addition of NAC, a ROS neutralizer, suppressed HMOX1/HO-1 expression under hypoxic conditions. These results suggest that HO-1 is induced in hypoxic environments by a ROS-mediated pathway. Next, we investigated the involvement of HO-1 in the effects of proteasome inhibitors in hypoxic environments. MTX assays showed that bortezomib against HMOX1 knockdown KMS-11 reduced cell viability under hypoxic rather than normoxic conditions. We transplanted HMOX1 knockdown or control KMS-11 (1×106 cells) into immunodeficient mice, injected bortezomib (1.0 mg/kg) intraperitoneally on days 14 and 18, and sacrificed the mice on day 22. There was no significant difference in subcutaneous tumor volume and weight between the control and HMOX1 knockdown cell lines, whereas HMOX1 knockdown resulted in a significant bortezomib-induced reduction in subcutaneous tumor volume and weight (p = 0.0009 and 0.0096, respectively). Lastly, we examined whether excessive levels of ROS enhance the effect of bortezomib. PMA and a low concentration of bortezomib (5 nM, which is lower than that for IC50) were added to KMS-11 and RPMI-8226, and an apoptosis assay was performed. As a result, PMA or a low concentration of bortezomib increased apoptotic cells by only a small percentage, while simultaneous exposure to both significantly increased apoptotic cells synergistically. This result indicates that excessive ROS levels enhance the anti-myeloma effect of proteasome inhibitors. Additionally, in clinical datasets, HMOX1 had a strong and significantly positive correlation with MAFB, but not MAF. We investigated whether MAFB actually regulates HMOX1 under hypoxic conditions. MAFB/MafB was induced by hypoxia even in a cell line without t(14;20) (q32;q12), such as KMS-11. Knockdown of MAFB significantly decreased HMOX1/HO-1 expression only under hypoxic condition, suggesting that MafB induction is involved in the elevated expression of HO-1 under hypoxic conditions. Conclusion We clarified the contribution of the hypoxia-ROS-HO-1 axis to proteasome inhibitor resistance in hypoxic environments. This axis might also be involved in hypoxia-induced MafB expression. Because mechanisms that reduce excessive ROS in hypoxic microenvironments are thought to be closely related to cell survival and drug resistance, targeting this mechanism may be a new strategy to overcome drug resistance in refractory MM.

Novel Evidence That Pineal Gland Hormone Melatonin Inhibits Migration of Hematopoietic Stem/Progenitor Cells (HSPCs) By Inhibiting Nlrp3 Inflammasome and Upregulating Heme Oxygenase-1 (HO-1) - Implications to Understand Better Diurnal Trafficking of HSPCs and Anti-Inflammatory Effects of Melatonin

Background. Hematopoietic stem progenitor cells (HSPCs) follow the diurnal circulation rhythm in peripheral blood (PB) with nadir during late night and pick at early morning hours. We have reported that the level of these cells in PB correlates with activation of innate immunity pathways, including complement cascade (ComC) (Stem Cell Rev Rep. 2018;14(5):677-685) that drives activation of Nlrp3 inflammasome (Stem Cell Rev Rep. 2020;16(2):335-343). Therefore, mice both in defective ComC activation as well as Nlrp3 inflammasome do not show typical changes in the diurnal level of circulating HSPCs. Cell migration is also inhibited by the anti-inflammatory enzyme heme oxygenase-1 (HO-1), which inhibits Nlrp3 inflammasome (Leukemia. 2022;36(1):23-32). It is well known that circadian rhythm is regulated by the release of melatonin from the pineal gland, which also has some anti-inflammatory effects (J. Pineal Res. 2018;65:e12525). Aim of the study.Since stem cell trafficking is driven by innate immunity-induced sterile inflammation and melatonin has an anti-inflammatory effect, we hypothesized that melatonin could negatively impact the release of HSPCs from bone marrow (BM) into PB by inhibiting Nlrp3 inflammasome activation. Materials and Methods. To test this hypothesis, first, we tested the expression of melatonin receptors in murine and human HSPCs. We employed Transwell system to see the effect of melatonin on the migration of human and murine HSPCs to the SDF-1 gradient. Next, we performed pharmacological mobilization of normal mice with G-CSF or AMD3100 in the presence of melatonin. Finally, employing Glow assay, we evaluated the effect of melatonin on activation of Nlrp3 inflammasome in HSPCs stimulated by BM chemotactic factors and the effect of melatonin on expression of migration inhibitory HO-1. Since membrane lipid rafts (MLRs) are crucial for the proper response of cells to chemoattractants, we also evaluated the effect of melatonin on the expression of enzymes (SREBP2, HMGCs, and HMGCR) involved in the synthesis of cholesterol and sphingolipids that are major constituents of MLRs. Results. We noticed that HSPCs express melatonin receptors, and melatonin inhibits in vitro Transwell assays migration of HSPCs and negatively affects mobilization of these cells into PB in response to G-CSF and AMD3100 administration. We also observed that melatonin inhibits Nlrp3 inflammasome activation and the formation of MLRs. This is explained by a decrease in the expression of enzymes such as SREBP2, HMGCs, and HMGCR involved in cholesterol synthesis leading to impaired formation of MLRs. Moreover, melatonin increases in HSPCs expression of heme oxygenase-1 (HO-1), that is a known inhibitor of Nlrp3 inflammasome and a negative regulator of cell migration. Conclusions. We provide for the first-time evidence that melatonin being a ''sleep regulating pineal hormone'' directly inhibits migration of HSPCs in vitro assays and in vivo their release from BM in response to G-CSF and AMD3100. This is correlated with inhibition of cholesterol synthesis, which results in defective assembly of MLRs, as well as a decrease in Nlrp3 inflammasome activity and an increase in expression of HO-1. Since melatonin is a commonly used shelf drug, this should be considered while preparing a patient for the procedure of HSPCs mobilization. More importantly, our studies shed more light on molecular mechanisms of melatonin involvement in the diurnal circulation of HSPCs.

Anti-Inflammatory Activity of Geraniol Isolated from Lemon Grass on Ox-LDL-Stimulated Endothelial Cells by Upregulation of Heme Oxygenase-1 via PI3K/Akt and Nrf-2 Signaling Pathways.

Among the world's leading causes of cardiovascular disease, atherosclerosis is a chronic inflammatory disorder that affects the arteries. Both vasodilation and vasoconstriction, low levels of nitric oxide and high levels of reactive oxygen species and pro-inflammatory factors characterize dysfunctional blood vessels. Hypertension, and atherosclerosis, all start with this dysfunction. Geraniol, a compound of acyclic monoterpene alcohol, found in plants such as geranium, lemongrass and rose, is a primary constituent of essential oils. It shows a variety of pharmacological properties. This study aimed to investigate the impact of geraniol on Ox-LDL-induced stress and inflammation in human umbilical vein endothelial cells. In this study, HUVECs were treated with Ox-LDL or geraniol at different dose concentrations. MTT assay, Western blot, ROS generation and DNA fragmentation were used to evaluate geraniol's effects on Ox-LDL-induced HUVECs inflammation. The results show that geraniol pre-incubation ameliorates Ox-LDL-mediated HUVECs cytotoxicity and DNA fragmentation. The geraniol inhibited the production of pro-inflammatory cytokines by Ox-LDL, including TNF-α, IL-6 and IL-1β. In Ox-LDL-stimulated HUVECs, geraniol suppresses the nuclear translocation and activity of NF-ᴋB as well as phosphorylation of IkBα. Moreover, geraniol activated the PI3K/AKT/NRF2 pathway in HUVECs, resulting in an increase in the expression of HO-1. Taking our data together, we can conclude that, in HUVECs, geraniol inhibits Ox-LDL-induced inflammation and oxidative stress by targeting PI3/AKT/NRF2.

Decreased PPARgamma in the trigeminal spinal subnucleus caudalis due to neonatal injury contributes to incision-induced mechanical allodynia in female rats

Whisker pad skin incision in infancy causes the prolongation of mechanical allodynia after re-incision in adulthood. A recent study also proposed the importance of sex differences in pain signaling in the spinal cord. However, the sex difference in re-incision-induced mechanical allodynia in the orofacial region is not fully understood. In the rats that experienced neonatal injury in the whisker pad skin, the mechanical allodynia in the whisker pad was significantly prolonged after re-incision in adulthood compared to sham injury in infancy. No significant sex differences were observed in the duration of mechanical allodynia. The duration of mechanical allodynia in male rats was shortened by intracisternal administration of minocycline. However, minocycline had no effects on the duration of mechanical allodynia in female rats. In contrast, intracisternal administration of pioglitazone markedly suppressed mechanical allodynia in female rats after re-incision. Following re-incision, the number of peroxisome proliferator-activated receptor gamma (PPARgamma)-positive cells were reduced in the trigeminal spinal subnucleus caudalis (Vc) in female rats that experienced neonatal injury. Immunohistochemical analyses revealed that PPARgamma was predominantly expressed in Vc neurons. Pioglitazone increased the number of PPARgamma-positive Vc neurons in female rats whose whisker pad skin was incised in both infancy and adulthood stages. Pioglitazone also upregulated heme oxygenase 1 and downregulated NR1 subunit in the Vc in female rats after re-incision. Together, PPARgamma signaling in Vc neurons is a female-specific pathway for whisker pad skin incision-induced mechanical allodynia.

Neuroprotective effect of canagliflozin against cisplatin-induced cerebral cortex injury is mediated by regulation of HO-1/PPAR-γ, SIRT1/FOXO-3, JNK/AP-1, TLR4/iNOS, and Ang II/Ang 1–7 signals

Objectives Canagliflozin (CAN), a sodium-glucose co-transporter 2 inhibitor, is an anti-hyperglycemic drug that has been approved to treat diabetes. This study evaluated the beneficial effects of CAN on cerebral cortex intoxication induced by cisplatin (CIS). Materials and methods Rats were allocated into four groups: normal control, CAN (10 mg/kg, P.O.) for 10 days, CIS (8 mg/kg, i.p.) as a single dose on the 5th day of the experiment, and CAN + CIS group. Results In comparison with CIS control rats, CAN significantly mitigated CIS-induced cortical changes in rats’ behavior in the open field and forced swimming assessment as well as histological structure. Biochemically, CAN administration efficiently decreased lipid peroxidation biomarkers MDA and boosted the antioxidant status via a remarkable increase in the cortical reduced glutathione (GSH) content as well as enzymatic activities of antioxidant enzymes superoxide dismutase (SOD), glutathione-S-transferase (GST), catalase (CAT), and glutathione peroxidase (GPx) mediated by up-regulation of heme oxygenase-1 (HO-1), peroxisome proliferator-activated receptors (PPARγ), and silent information regulator (SIRT1)/forkhead box-O3 (FOXO-3) signals. Additionally, pretreatment with CAN significantly decreased cortical myeloperoxidase (MPO), nitrite (NO2 –), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) levels. At the same time, it elevated the IL-10 level associated with the downregulation of Jun N-terminal kinase (JNK)/activator protein 1 (AP-1), TLR4/inducible nitric oxide synthase (iNOS)/nitric oxide (NO), and Ang II/Ang 1–7 signals. Conclusions Due to the potent antioxidant and anti-inflammatory properties of CAN, our findings showed that CAN could be a good candidate for the protection against CIS-induced cortical intoxication in the patient receiving CIS.

Betanin ameliorates fipronil-induced nephrotoxicity via activation of Nrf2-HO-1/NQO-1 pathway in albino rat model.

Fipronil (FPN) is phenylpyrazole insecticide extensively used to control a wide variety of pests. Betanin (BET) is a natural colorant with promising antioxidant and anti-inflammatory effects. This study aimed to investigate the potential protective effect of BET on FPN induced nephrotoxicity in adult male albino rats. Forty rats were assigned into 4 equal groups; Group I (Control); Group II (BET) received 20mg/kg b.wt/day; Group III (FPN) received 4.8mg/kg b.wt/day; and Group IV (BET/FPN). All treatments were given orally for 90days. At the end of experiment, blood samples were collected for analysis of serum urea and creatinine. Kidneys were harvested for determination of kidney injury molecule-1(KIM-1) level; gene expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NAD(P)H: quinone oxidoreductase-1 (NQO-1); oxidative stress biomarkers including malondialdehyde (MDA), protein carbonyl content (PCC), catalase activity (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH). Histopathological examination and immunohistochemical investigation of Nrf2, nuclear factor kappa B (NF-κB), and caspase-3 were also undertaken. The results revealed kidney dysfunction, downregulation of Nrf2, HO-1, and NQO-1 genes, redox imbalance, structural damage, decreased Nrf2 and increased NF-κB immune-expression, in addition to strong caspase-3 immunoreactivity in FPN-treated group. In the combined group, BET co-administration resulted in functional and structural amelioration, up-regulation of Nrf2, HO-1, and NQO-1 genes, mitigation of redox imbalance, and strong anti-inflammatory and antiapoptotic effects. In conclusion, BET via activation of Nrf2-HO-1/NQO-1 pathway, exhibits beneficial antioxidant, anti-inflammatory, and antiapoptotic effects against FPN-induced nephrotoxicity.

Photooxidation of A2E by Blue Light Regulates Heme Oxygenase 1 Expression via NF-κB and Lysine Methyltransferase 2A in ARPE-19 Cells.

Background: N-retinylidene-N-retinylethanolamine (A2E) is a component of drusen that accumulates in retinal cells and induces oxidative stress through photooxidation, such as blue light (BL). We found that the heme oxygenase 1 (HMOX1) gene responds sensitively to photooxidation by the BL of A2E in retinal pigment epithelial (RPE) cells, and we sought to identify the transcription factors and coactivators involved in the upregulation of HMOX1 by A2E and BL. Methods: A2E-laden human RPE cells (ARPE-19) were exposed to BL (430 nm). RNA sequencing was performed to identify genes responsive to BL exposure. Chromatin immunoprecipitation and RT-qPCR were performed to determine the regulation of HMOX1 transcription. Clinical transcriptome data were used to evaluate HMOX1 expression in patients with age-related macular degeneration (AMD). Results: In ARPE-19 cells, the expression of HMOX1, one of the NF-κB target genes, was significantly increased by A2E and BL. The binding of RELA and RNA polymerase II to the promoter region of HMOX1 was significantly increased by A2E and BL. Lysine methyltransferase 2A (MLL1) plays an important role in H3K4me3 methylation, NF-κB recruitment, chromatin remodeling at the HMOX1 promoter, and, subsequently, HMOX1 expression. The retinal tissues of patients with late-stage AMD showed significantly increased expression of HMOX1 compared to normal retinal tissues. In addition, the expression levels of MLL1 and HMOX1 in retinal tissues were correlated. Conclusions: Taken together, our results suggest that BL induces HMOX1 expression by activating NF-κB and MLL1 in RPE cells.

Oxygen-boosted biomimetic nanoplatform for synergetic phototherapy/ferroptosis activation and reversal of immune-suppressed tumor microenvironment

Photodynamic therapy (PDT) induces apoptosis of cancer cells by generating cytotoxic reactive oxygen species, the therapeutic effect of which, however, is impeded by intrinsic/inducible apoptosis-resistant mechanisms in cancer cells and hypoxia of tumor microenvironment (TME); also, PDT-induced anti-tumor immunity activation is insufficient. To deal with these obstacles, a novel biomimetic nanoplatform is fabricated for the precise delivery of photosensitizer chlorin e6 (Ce6), hemin and PEP20 (CD47 inhibitory peptide), integrating oxygen-boosted PDT, ferroptosis activation and CD47-SIRPα blockade. Hemin's catalase-mimetic activity alleviates TME hypoxia and enhances PDT. The nanoplatform activates ferroptosis via both classical (down-regulating glutathione peroxidase 4 pathway) and non-classical (inducing Fe2+ overload) modes. Besides the role of hemin in consuming glutathione and up-regulating heme oxygenase-1 expression, interestingly, we observe that Ce6 enhance ferroptosis activation via both classical and non-classical modes. The anti-cancer immunity is reinforced by combining PEP20-mediated CD47-SIRPα blockade and PDT-mediated T cell activation, efficiently suppressing primary tumor growth and metastasis. PEP20 has been revealed for the first time to sensitize ferroptosis by down-regulating system Xc−. This work sheds new light on the mechanisms of PDT-ferroptosis activation interplay and bridges immunotherapy and ferroptosis activation, laying the theoretical foundation for novel combinational modes of cancer treatment.

Heme oxygenase-1 modulates ferroptosis by fine-tuning levels of intracellular iron and reactive oxygen species of macrophages in response to Bacillus Calmette-Guerin infection.

Macrophages are the host cells and the frontline defense against Mycobacterium tuberculosis (Mtb) infection, and the form of death of infected macrophages plays a pivotal role in the outcome of Mtb infections. Ferroptosis, a programmed necrotic cell death induced by overwhelming lipid peroxidation, was confirmed as one of the mechanisms of Mtb spread following infection and the pathogenesis of tuberculosis (TB). However, the mechanism underlying the macrophage ferroptosis induced by Mtb infection has not yet been fully understood. In the present study, transcriptome analysis revealed the upregulation of heme oxygenase-1 (HMOX1) and pro-ferroptosis cytokines, but downregulation of glutathione peroxidase 4 (GPX4) and other key anti-lipid peroxidation factors in the peripheral blood of both patients with extra-pulmonary tuberculosis (EPTB) and pulmonary tuberculosis (PTB). This finding was further corroborated in mice and RAW264.7 murine macrophage-like cells infected with Bacillus Calmette-Guerin (BCG). A mechanistic study further demonstrated that heme oxygenase-1 protein (HO-1) regulated the production of reactive oxygen species (ROS) and iron metabolism, and ferroptosis in BCG-infected murine macrophages. The knockdown of Hmox1 by siRNA resulted in a significant increase of intracellular ROS, Fe2+, and iron autophagy-mediated factor Ncoa4, along with the reduction of antioxidant factors Gpx4 and Fsp1 in macrophages infected with BCG. The siRNA-mediated knockdown of Hmox1 also reduced cell survival rate and increased the release of intracellular bacteria in BCG-infected macrophages. By contrast, scavenging ROS by N-acetyl cysteine led to the reduction of intracellular ROS, Fe2+, and Hmox1 concentrations, and subsequently inhibited ferroptosis and the release of intracellular BCG in RAW264.7 cells infected with BCG. These findings suggest that HO-1 is an essential regulator of Mtb-induced ferroptosis, which regulates ROS production and iron accretion to alter macrophage death against Mtb infections.

Changes of Oxidative Stress-Related Gene Expression in an in vitro Model of Neonatal Hypoxic-Ischemic Encephalopathy

Background: We recently demonstrated that oxygen-glucose deprivation (OGD) and unconjugated bilirubin (UCB) can damage mature and immature organotypic hippocampal slices and induce an oxidative stress similar to what occurs in jaundiced term and preterm infants with hypoxic-ischemic encephalopathy (HIE). Objectives: To assess the effects of OGD and UCB on the expression of heme-oxygenase 1 (HO-1) and oxidative stress-related enzymes in an in vitro model of HIE. Methods: Mature and immature organotypic hippocampal slices were exposed to 30-min OGD and to 24 h UCB or UCB plus human serum albumin (HSA). The expression of HO-1, superoxide dismutase 1 (SOD1), catalase (CAT), glutathione peroxidase (GPX), and nuclear factor erythroid-related factor 2 were analyzed by real-time PCR. Results: In mature slices, OGD did not affect the expression of HO-1 and oxidative stress-induced enzymes. The addition of UCB was associated with the upregulation of HO-1 and Nrf2 that is abolished by the presence of equimolar amount of HSA. In immature slices, OGD induced the downregulation of CAT, GPX, and Nrf2 expression and the addition of UCB further decreased GPX. The addition of UCB and HSA reverted the effects of OGD and UCB on gene expression. Conclusions: In an in vitro model of HIE in term infants, we did not observe neuroprotective changes of the expression of HO-1 and genes involved in antioxidant defenses. Conversely, in an in vitro model of HIE in preterm infants, we observed a harmful decrease of the expression of genes encoding for antioxidant enzymes.

The Activation of Nrf2/HO-1 by 8-Epi-7-deoxyloganic Acid Attenuates Inflammatory Symptoms through the Suppression of the MAPK/NF-κB Signaling Cascade in In Vitro and In Vivo Models.

In this study, we examined the ameliorative effects of 8-epi-7-deoxyloganic acid (DLA), an iridoid glycoside, on oxidative stress and inflammation in both LPS-stimulated macrophages and mice with carrageenan-induced inflammation. DLA decreased oxidative stress through the up-regulation of heme oxygenase-1 (HO-1) via the activation of nuclear factor erythroid 2-related factor 2 (Nrf2), leading to the suppression of reactive oxygen species (ROS) and nitric oxide generation (NO). In addition, DLA inhibited the activation of mitogen-activated protein kinases (MAPKs) and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway, resulting in a decreased production of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) and -6 (IL-6), as well as of monocyte chemoattractant protein-1 (MCP-1). In addition, DLA effectively inhibited the generation of nitric oxide (NO) and prostaglandin E2 (PGE2) by inhibiting the expression of the upstream genes inducible nitric oxidase (iNOS) and cyclooxygenase-2 (COX-2). DLA demonstrated powerful anti-inflammatory and antioxidant properties and thus appears as an intriguing prospective therapeutic treatment.

Respiratory Exposure to Copper Oxide Particles Causes Multiple Organ Injuries via Oxidative Stress in a Rat Model.

IntroductionThe wide application of copper oxide nanoparticles (CuO NPs) in industry, agriculture, environmental remediation, and biomedicine has increased the risk of human exposure to CuO NPs. Recent studies suggested that CuO NPs have genotoxic and cytotoxic effects on various cells. However, little is known about the toxicity of CuO NPs on major peripheral organs after respiratory exposure.Materials and MethodsWe investigated the toxicities of CuO NPs on human bronchial epithelial (BEAS-2B) and human cardiomyocytes (AC16) cells in vitro, and on the lungs, liver, kidneys, and heart of spontaneously hypertensive rats (SHRs) at 24 and 72 h after intrabronchial instillation in vivo.ResultsCuO NPs induced concentration-dependent toxicities in both BEAS-2B and AC16 cells mainly through hierarchical oxidative stress mechanisms, involving generation of reactive oxygen species (ROS), upregulation of heme oxygenase-1 (HO-1), mitochondrial dysfunction, and secretion of proinflammatory and profibrogenic cytokines. Respiratory exposure to CuO NPs induced acute multiple organ injuries in SHRs manifesting through inflammation and fibrosis. However, cardiac injury was relatively less severe than injuries in the lungs, liver, and kidneys. Upregulation of serum C-reaction protein (CRP), tumor necrosis factor α (TNF-α), intercellular adhesion molecule 1 (ICAM-1), endothelin-1 (ET-1), angiotensin converting enzyme (ACE), and von Willebrand factor (vWF) after exposure to CuO NPs indicated systematic inflammation, endothelial injury, and potential prothrombosis.ConclusionRespiratory exposure to CuO NPs induced acute injuries in main peripheral organs, including the lungs, liver, kidneys, and heart. Individuals with existing cardiovascular diseases were susceptible to exposure to CuO NPs. This study provides a warning about the extensive toxic effects of CuO NPs, especially in the susceptible population.