Upregulation Of Heme Oxygenase-1 Expression Research Articles

Gastrodin plays a protective role in alleviating hepatic ischemia reperfusion injury by regulating heme oxygenase-1 expression.

Hepatic ischemia reperfusion injury (HIRI) is a pathophysiological and complex systemic process involving multiple tissues and organs. Gastrodin (GSTD), a natural compound from Gastrodia elata, displays a variety of interesting pharmacological activities. Heme oxygenase-1 (HO-1), a stress-responsive protein, has a cytoprotective defense response against oxidative and inflammatory injuries. The aim of this investigation was to elucidate whether GSTD plays a protective role against HIRI by regulating HO-1 expression. GSTD (100 mg/kg) or zinc protoporphyrin (15 mg/kg; an HO-1 inhibitor) was administered to HIRI C57 male mice. GSTD decreased glutamic pyruvic transaminase and glutamic oxaloacetic transaminase levels in HIRI mice. Inflammatory (TNF-α and IL-6) and oxidative-stress (malondialdehyde, MDA) markers of HIRI mice were decreased by GSTD. GSTD up-regulated HO-1 protein and mRNA expression in HIRI mice but decreased caspase-3 and -9 protein expression. GSTD lowered mRNA expression of apoptosis-related genes (caspase-3, -9, -12, and Bax) in the liver of HIRI mice but enhanced mRNA level of the anti-apoptotic Bcl-2 gene. Consistent with in vivo results, GSTD displayed a similar regulatory effect on the expression of mRNA (HO-1, caspase-3, -9, -12, Bax, and Bcl-2) and protein (HO-1, caspase-3 and -9) as well as inflammatory (TNF-α and IL-6) and on oxidative stress factors (superoxide dismutase and MDA) in BRL-3A cells transfected with small interfering HO-1 RNA in a hypoxia-reperfusion model. In conclusion, GSTD up-regulated HO-1 expression to play a protective role in HIRI by anti-apoptotic, anti-inflammatory, and antioxidant effects. GSTD is a promising natural compound that alleviated HIRI in liver surgery.

HO-1 impairs the efficacy of radiotherapy by redistributing cGAS and STING in tumors.

Type I IFNs (IFN-Is) induced by radiotherapy (RT) are critical for its efficacy, while the mechanism by which tumor cells inhibit IFN-I production remains largely unsolved. By an unbiased CRISPR screen, we identified hemeoxygenase 1 (HO-1) as an RT-related regulator of IFN-I production. Mechanistically, the ER-anchored, full-length HO-1 disrupted stimulator of IFN genes (STING) polymerization and subsequent coat protein complex II-mediated (COPII-mediated) ER-Golgi transportation, leading to hampered activation of downstream signaling. This process was exacerbated by the upregulation of HO-1 expression under RT. Importantly, RT also induced HO-1 cleavage. Cleaved HO-1 underwent nuclear translocation, interacted with cyclic GMP-AMP synthase (cGAS), and inhibited its nuclear export upon irradiation, leading to suppressed 2'3'-cyclic GMP-AMP (cGAMP) production. Furthermore, we revealed that HO-1 inhibitors could enhance local and distant tumor control of RT in vivo. Clinically, higher HO-1 expression was associated with a poorer prognosis and earlier tumor relapse after RT in multiple types of patient tumors. Collectively, through comprehensive inhibition of the cGAS/STING pathway, HO-1 strongly inhibited RT-induced IFN-I production, and targeting HO-1 was shown to be a promising RT-sensitizing therapeutic strategy.

Validation of Active Compound of Terminalia catappa L. Extract and Its Anti-Inflammatory and Antioxidant Properties by Regulating Mitochondrial Dysfunction and Cellular Signaling Pathways.

As chronic inflammation and oxidative stress cause various diseases in the human body, this study aimed to develop functional materials to prevent inflammation and oxidative stress. This study investigated the biological function and components of Terminalia catappa L. extract prepared using its leaves and branches (TCE). TCE was determined using ultraperformance liquid chromatography-quadrupole-time-of-flight mass spectrometry. Using RAW 264.7 mouse macrophages, inhibitory effects of the identified compounds on nitric oxide (NO) and reactive oxygen species (ROS) generation were analyzed. Therefore, α-punicalagin was selected as an active compound with the highest content (986.6 ± 68.4 μg/g) and physiological activity. TCE exhibited an inhibitory effect on lipopolysaccharide (LPS)-induced inflammatory markers, including NO, inducible nitric oxide synthase, and inflammatory cytokines without exerting cytotoxicity. Moreover, TCE prevented excessive ROS production mediated by LPS and upregulated hemeoxygenase-1 expression via the nuclear translocation of nuclear factor erythroid 2-related factor 2. Interestingly, TCE prevented LPS-induced mitochondrial membrane potential loss, mitochondrial ROS production, and dynamin-related protein 1 phosphorylation (serine 616), a marker of abnormal mitochondrial fission. Furthermore, TCE considerably repressed the activation of LPS-induced mitogen-activated protein kinase pathway. Thus, TCE is a promising anti-inflammatory and antioxidant pharmaceutical or nutraceutical, as demonstrated via mitochondrial dysfunction and cellular signaling pathway regulation.

Butylphthalide inhibits ferroptosis and ameliorates cerebral Ischaemia–Reperfusion injury in rats by activating the Nrf2/HO-1 signalling pathway

This study aims to investigate whether butylphthalide can inhibit ferroptosis and ameliorate cerebral ischaemia–reperfusion (I/R) injury in rats by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) / heme oxygenase-1 (HO-1) signalling pathway, known for its antioxidative and cytoprotective properties. Middle cerebral artery occlusion reperfusion (MCAO/R) rat models were established. Male rats were randomly divided into five groups: a sham-operated group (sham), MCAO/R group, MCAO/R ​+ ​ML385 (Nrf2-specific inhibitor) group, MCAO/R ​+ ​NBP (butylphthalide) group and MCAO/R ​+ ​ML385 ​+ ​NBP group. The effect of butylphthalide on cerebral I/R injury was evaluated using neurological deficit scores. The expression levels of Nrf2, HO-1, glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4) and transferrin receptor 1 (TfR1) protein were detected using Western blot. Moreover, the expression levels of GPX4, HO-1 and TfR1 mRNA were determined through real-time fluorescence quantitative reverse transcription polymerase chain reaction. The distribution of Nrf2, HO-1, GPX4 and TfR1 was detected using immunohistochemical staining. The levels of iron and related lipid peroxidation indexes, such as reduced glutathione, reactive oxygen species, malondialdehyde and nitric oxide, were measured using a kit. The changes in mitochondria were observed through transmission electron microscopy. Butylphthalide treatment significantly improved neurological dysfunction, reduced cerebral infarction volume and mitigated histopathological damage in MCAO/R rats. It induced the nuclear translocation of Nrf2 and upregulated HO-1 expression, which was attenuated by ML385. Butylphthalide also attenuated lipid peroxidation, iron accumulation and mitochondrial damage induced by MCAO/R. The expression of GPX4, ACSL4 and TfR1 proteins, as well as their mRNA levels, was modulated through butylphthalide treatment, with improvements observed in mitochondrial morphology. Butylphthalide exerts neuroprotective effects by attenuating neurological dysfunction and ferroptosis in MCAO/R rats through the activation of the Nrf2/HO-1 pathway and inhibition of lipid peroxidation and iron accumulation.

Potential skin anti-aging effects of main phenolic compounds, tremulacin and tremuloidin from Salix chaenomeloides leaves on TNF-α-stimulated human dermal fibroblasts

The genus Salix spp. has long been recognized as a healing herb for its use in treating fever, inflammation, and pain relief, as well as a food source for its nutritional value. In this study, we aimed to explore the potential bioactive natural products in the leaves of Salix chaenomeloides, commonly known as Korean pussy willow, for their protective effects against skin damage, including aging. Utilizing LC/MS-guided chemical analysis of the ethanol extract of S. chaenomeloides leaves, with a focus on major compounds, we successfully isolated two main phenolic compounds, tremulacin (1) and tremuloidin (2). Subsequently, we investigated the protective effects of tremulacin (1) and tremuloidin (2) in TNF-α-stimulated human dermal fibroblasts (HDFs). The results revealed that both tremulacin (1) and tremuloidin (2) inhibited TNF-α-stimulation-induced ROS, suppressed matrix metalloproteinase-1 (MMP-1) expression, and enhanced collagen secretion. This implies that both tremulacin (1) and tremuloidin (2) hold promise as preventive agents against photoaging-induced skin aging. Furthermore, we assessed the activity of mitogen-activated protein kinases (MAPKs), cyclooxygenase-2 (COX-2), and heme oxygenase 1 (HO-1) to elucidate the mechanism of photoaging inhibition by tremuloidin (2), which exhibited superior efficacy. We found that tremuloidin (2) inhibited ERK and p38 phosphorylation and notably suppressed COX-2 expression while significantly upregulating HO-1 expression. These findings suggest potent anti-inflammatory and antioxidant properties of tremuloidin (2), positioning it as a potential candidate for combating photoaging-induced skin aging.

Oral administration of osthole mitigates maladaptive behaviors through PPARα activation in mice subjected to repeated social defeat stress

Psychological stress induces neuroinflammatory responses, which are associated with the pathogenesis of various psychiatric disorders, such as posttraumatic stress disorder and anxiety. Osthole—a natural coumarin isolated from the seeds of the Chinese herb Cnidium monnieri—exerts anti-inflammatory and antioxidative effects on the central nervous system. However, the therapeutic benefits of osthole against psychiatric disorders remain largely unknown. We previously demonstrated that mice subjected to repeated social defeat stress (RSDS) in the presence of aggressor mice exhibited symptoms of posttraumatic stress disorder, such as social avoidance and anxiety-like behaviors. In this study, we investigated the therapeutic effects of osthole and the underlying molecular mechanisms. Osthole exerted therapeutic effects on cognitive behaviors, mitigating anxiety-like behaviors and social avoidance in a mouse model of RSDS. The anti-inflammatory response induced by the oral administration of osthole was strengthened through the upregulation of heme oxygenase-1 expression. The expression of PPARα was inhibited in mice subjected to RSDS. Nonetheless, osthole treatment reversed the inhibition of PPARα expression. We identified a positive correlation between heme oxygenase-1 expression and PPARα expression in osthole-treated mice. In conclusion, osthole has potential as a Chinese herbal medicine for anxiety disorders. When designing novel drugs for psychiatric disorders, researchers should consider targeting the activation of PPARα.

Suppression of inflammation in ulcerative colitis rats by avocado and pomegranate

BackgroundPomegranate seed oil (PSO) and avocado seed oil (ASO) are natural polyphenols with established anti-inflammatory activity. PurposeThis study aimed to investigate the molecular mechanisms underlying the therapeutic efficacy of PSO and ASO in experimental ulcerative colitis (UC) with reference to sulfasalazine (SLZ). MethodsEighty male albino rats were divided equally into 8 groups; Normal, PSO, ASO, SLZ, UC-control, (UC+PSO), (UC+ASO) and (UC+SLZ) groups. Colitis was induced by intra-rectal injection of acetic acid. PSO (0.5ml/ 200g), ASO (1ml/ 250g) and SLZ (100mg/kg) were administered orally once/day for 14 days, 24h after colitis induction. Colitis was evaluated by measuring disease activity index (DAI), colon weight/length ratio and histologic inflammatory score. Vascular endothelial growth factor receptor-2 (VEGFR-2), colonic macrophage migration inhibitory factor (MIF), and malondialdehyde (MDA) were determined. Colonic gene expression of TNF-α, VEGF and heme oxygenase-1 (HO-1) were also estimated. ResultsPSO and ASO treatments to UC rats significantly reduced DAI, weight/length ratio, VEGFR-2, and colon histologic inflammatory score versus UC-controls. ASO significantly suppressed MIF levels and TNF-α expression greater than PSO. However, PSO was more significant than ASO in reducing MDA levels and up-regulating HO-1 expression. Both oils significantly down-regulated VEGF expression. The obtained biochemical and histological changes induced by UC were nearly corrected by SLZ. ConclusionThe proved beneficial effect of PSO and ASO as anti-inflammatory, anti-angiogenic, and antioxidant in UC rats could be mediated by suppression of TNF-α, VEGF, and MIF and up-regulation of HO-1.

NCAM mimetic peptide P2 synergizes with bone marrow mesenchymal stem cells in promoting functional recovery after stroke

The neural cell adhesion molecule (NCAM) promotes neural development and regeneration. Whether NCAM mimetic peptides could synergize with bone marrow mesenchymal stem cells (BMSCs) in stroke treatment deserves investigation. We found that the NCAM mimetic peptide P2 promoted BMSC proliferation, migration, and neurotrophic factor expression, protected neurons from oxygen-glucose deprivation through ERK and PI3K/AKT activation and anti-apoptotic mechanisms in vitro. Following middle cerebral artery occlusion (MCAO) in rats, P2 alone or in combination with BMSCs inhibited neuronal apoptosis and induced the phosphorylation of ERK and AKT. P2 combined with BMSCs enhanced neurotrophic factor expression and BMSC proliferation in the ischemic boundary zone. Moreover, combined P2 and BMSC therapy induced translocation of nuclear factor erythroid 2-related factor, upregulated heme oxygenase-1 expression, reduced infarct volume, and increased functional recovery as compared to monotreatments. Treatment with LY294002 (PI3K inhibitor) and PD98059 (ERK inhibitor) decreased the neuroprotective effects of combined P2 and BMSC therapy in MCAO rats. Collectively, P2 is neuroprotective while P2 and BMSCs work synergistically to improve functional outcomes after ischemic stroke, which may be attributed to mechanisms involving enhanced BMSC proliferation and neurotrophic factor release, anti-apoptosis, and PI3K/AKT and ERK pathways activation.

Metformin alleviates spinal cord injury by inhibiting nerve cell ferroptosis through upregulation of heme oxygenase-1 expression.

JOURNAL/nrgr/04.03/01300535-202409000-00037/figure1/v/2024-01-16T170235Z/r/image-tiff Previous studies have reported upregulation of heme oxygenase-1 in different central nervous system injury models. Heme oxygenase-1 plays a critical anti-inflammatory role and is essential for regulating cellular redox homeostasis. Metformin is a classic drug used to treat type 2 diabetes that can inhibit ferroptosis. Previous studies have shown that, when used to treat cardiovascular and digestive system diseases, metformin can also upregulate heme oxygenase-1 expression. Therefore, we hypothesized that heme oxygenase-1 plays a significant role in mediating the beneficial effects of metformin on neuronal ferroptosis after spinal cord injury. To test this, we first performed a bioinformatics analysis based on the GEO database and found that heme oxygenase-1 was upregulated in the lesion of rats with spinal cord injury. Next, we confirmed this finding in a rat model of T9 spinal cord compression injury that exhibited spinal cord nerve cell ferroptosis. Continuous intraperitoneal injection of metformin for 14 days was found to both upregulate heme oxygenase-1 expression and reduce neuronal ferroptosis in rats with spinal cord injury. Subsequently, we used a lentivirus vector to knock down heme oxygenase-1 expression in the spinal cord, and found that this significantly reduced the effect of metformin on ferroptosis after spinal cord injury. Taken together, these findings suggest that metformin inhibits neuronal ferroptosis after spinal cord injury, and that this effect is partially dependent on upregulation of heme oxygenase-1.

Adeno-associated virus-9 reverses delayed gastric emptying of solids in diabetic mice.

Gastroparesis is defined by delayed gastric emptying (GE) without obstruction. Studies suggest targeting heme oxygenase-1 (HO1) may ameliorate diabetic gastroparesis. Upregulation of HO1 expression via interleukin-10 (IL-10) in the gastric muscularis propria is associated with reversal of delayed GE in diabetic NOD mice. IL-10 activates the M2 cytoprotective phenotype of macrophages and induces expression of HO1 protein. Here, we assess delivery of HO1 by recombinant adeno-associated viruses (AAVs) in diabetic mice with delayed GE. C57BL6 diabetic delayed GE mice were injected with 1 × 1012 vg scAAV9-cre, scAAV9-GFP, or scAAV9-HO1 particles. Changes to GE were assessed weekly utilizing our [13 C]-octanoic acid breath test. Stomach tissue was collected to assess the effect of scAAV9 treatment on Kit, NOS1, and HO1 expression. Delayed GE returned to normal within 2 weeks of treatment in 7/12 mice receiving scAAV9-cre and in 4/5 mice that received the scAAV9-GFP, whereas mice that received scAAV9-HO1 did not respond in the same manner and had GE that took significantly longer to return to normal (6/7 mice at 4-6 weeks). Kit, NOS1, and HO1 protein expression in scAAV9-GFP-treated mice with normal GE were not significantly different compared with diabetic mice with delayed GE. Injection of scAAV9 into diabetic C57BL6 mice produced a biological response that resulted in acceleration of GE independently of the cargo delivered by the AAV9 vector. Further research is needed to determine whether use of AAV mediated gene transduction in the gastric muscularis propria is beneficial and warranted.

The protective effects of EGCG was associated with HO-1 active and microglia pyroptosis inhibition in experimental intracerebral hemorrhage

Intracerebral hemorrhage (ICH), which has high mortality and disability rate is associated with microglial pyroptosis and neuroinflammation, and the effective treatment methods are limited Epigallocatechin-3-gallate (EGCG) has been found to play a cytoprotective role by regulating the anti-inflammatory response to pyroptosis in other systemic diseases. However, the role of EGCG in microglial pyroptosis and neuroinflammation after ICH remains unclear. In this study, we investigated the effects of EGCG pretreatment on neuroinflammation-mediated neuronal pyroptosis and the underlying neuroprotective mechanisms in experimental ICH. EGCG pretreatment was found to remarkably improved neurobehavioral performance, and decreased the hematoma volume and cerebral edema in mice. We found that EGCG pretreatment attenuated the release of hemin-induced inflammatory cytokines (IL-1β, IL-18, and TNF-α). EGCG significantly upregulated the expression of heme oxygenase-1 (HO-1), and downregulated the levels of pyroptotic molecules and inflammatory cytokines including Caspase-1, GSDMD, NLRP3, mature IL-1β, and IL-18. EGCG pretreatment also decreased the number of Caspase-1-positive microglia and GSDMD along with NLRP3-positive microglia after ICH. Conversely, an HO-1-specific inhibitor (ZnPP), significantly inhibited the anti-pyroptosis and anti-neuroinflammation effects of EGCG. Therefore, EGCG pretreatment alleviated microglial pyroptosis and neuroinflammation, at least in part through the Caspase-1/GSDMD/NLRP3 pathway by upregulating HO-1 expression after ICH. In addition, EGCG pretreatment promoted the polarization of microglia from the M1 phenotype to M2 phenotype after ICH. The results suggest that EGCG is a potential agent to attenuate neuroinflammation via its anti-pyroptosis effect after ICH.

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.

Paired Box Gene 6 Regulates Heme Oxygenase-1 Expression and Mitigates Hydrogen Peroxide-Induced Oxidative Stress in Lens Epithelial Cells

Purpose This study aimed to investigate the regulation of heme oxygenase-1 (HO-1) by paired box gene 6 (Pax6) and their roles in hydrogen peroxide (H2O2)-induced oxidative stress and apoptosis in lens epithelial cells (LECs) (SRA01/04, HLE-B3). Methods Lens anterior capsule membranes of mice of different ages were obtained to compare differences in the expression of Pax6 and HO-1 using Western blotting. Pax6-overexpressing plasmid and small interfering RNA were designed to overexpress and silence Pax6, respectively. Cobalt protoporphyrin (CoPP) was used to promote the expression of HO-1. Oxidative damage in LECs was induced by treatment with H2O2 (400 µM) for 24 h. Cell viability was measured using the Cell Counting Kit-8 assay. Intracellular reactive oxygen species (ROS) were detected using flow cytometry and immunofluorescence. Superoxide dismutase (SOD) level was measured using SOD Assay Kit and apoptotic cells were quantified using annexin V-fluorescein isothiocyanate/propidium iodide staining. Results Pax6 and HO-1 expression levels showed an age-dependent decrease in LECs of mouse. Overexpressing Pax6 upregulated HO-1 expression level. Silencing Pax6 downregulated the HO-1 expression level, resulting in increased generation of ROS, reduced SOD activity, decreased cell viability, and increased apoptotic cells of LECs under H2O2-induced oxidative stress. Overexpressing Pax6 and CoPP both mitigates H2O2-induced oxidative stress by increasing the expression of HO-1 of LECs. Conclusion Pax6 and HO-1 expression levels showed an age-dependent decrease in LECs in mouse anterior capsules. Pax6 could regulate the expression of HO-1 in LECs. The decrease of Pax6 weakened the antioxidant ability of LECs under H2O2-induced oxidative stress by downregulating HO-1, which may be a potential mechanism for the formation of age-related cataract.

P-TAK1 acts as a switch between myoblast proliferation phase and differentiation phase in mdx mice via regulating HO-1 expression

Skeletal muscle transforming growth factor-β-activated kinase 1 (TAK1) continuous excessive phosphorylation was observed in Duchenne muscular dystrophy (DMD) patients and mdx mice. Inhibiting TAK1 phosphorylation ameliorated fibrosis and muscular atrophy, while TAK1 knockout also impaired muscle regeneration. The definite effect and mechanism of p-TAK1 in muscle regeneration disorder is still obscure. In this study, BaCl2-induced acute muscle injury model was used to investigate the role of p-TAK1 in myoblast proliferation and differentiation phase. The results showed that TAK1 phosphorylation was significantly up-regulated in proliferation phase along with Keap1/Nrf2/HO-1 signaling pathway activation, which was down-regulated in differentiation phase yet. In C2C12 cells, inhibiting TAK1 phosphorylation markedly suppressed the expression of heme oxygenase-1 (HO-1), and both myoblast proliferation and differentiation were inhibited. As for activation, p-TAK1 promoted myoblast proliferation via up-regulating HO-1 level. However, excessive TAK1 phosphorylation (induced by 20 ng·mL−1 TGF-β1) notably up-regulated HO-1 expression, inhibiting myogenic differentiation antigen (MyOD) and myogenic differentiation. A mild p-TAK1 level (induced by 5 or 10 ng·mL−1 TGF-β1) was beneficial for myoblast differentiation. In mdx mice, robust myoblast proliferation and differentiation arrest were observed with high p-TAK1 level in skeletal muscle. HO-1 expression was significantly up-regulated. TAK1 phosphorylation inhibitor NG25 (N-[4-[(4-ethylpiperazin-1-yl)methyl]-3-(trifluoromethyl)phenyl]-4-methyl-3-(1H-pyrrolo[2,3-b]pyridin-4-yloxy)benzamide) significantly inhibited HO-1 expression, relieved excessive myoblast proliferation and differentiation arrest, promoted new myofiber formation, and eventually improved muscle function. In conclusion, p-TAK1 acted as “a switch” between proliferation and differentiation phase. Mitigating p-TAK1 level transformed myoblast excessive proliferation phase into differentiation phase in mdx mouse via regulating HO-1 expression.

Hydrogen-rich medium ameliorates lipopolysaccharides-induced mitochondrial fission and dysfunction in human umbilical vein endothelial cells (HUVECs) via up-regulating HO-1 expression

BackgroundSepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. It has been showed that the change of mitochondrial dynamics has been proved to be one of the main causes of death in patients with severe sepsis. And hydrogen has been proved to exert its protective effects against sepsis via heme oxygenase-1 (HO-1). This study was designed to demonstrate that whether the benefit effects of hydrogen can maintain the dynamic process of mitochondrial fusion/fission to mitigate human umbilical vein endothelial cells (HUVECs) injury exposed to endotoxin through HO-1. MethodsHUVECs cells cultured with medium which contained Lipopolysaccharides (LPS), Saline, hydrogen, Mdivi-1 (a dynamin-related protein 1 [Drp1] inhibitor) or zinc protoporphyrin IX (Znpp) (a HO-1 inhibitor) were also used in the research. Cell death and apoptosis were assessed using FITC annexin V and PI. Mitochondria were stained with Mitotracker orange and observed by confocal microscope. Oxygen consumption rate was assessed by seahorse xf24 extracellular analyzer. Mitochondrial membrane potential monitored by JC-1 dye. The expressions of Drp1 and HO-1 were tested by Western blot. The co-localization of Drp1 and mitochondria was determined by immunofluorescence. ResultsLPS caused a decrease in ATP content, mitochondrial membrane potential, and maximal respiration rate. At the same time, increased expression of Drp1 were observed in LPS-stimulated HUVECs, concomitantly with excessive mitochondrial fission. We found that hydrogen-rich medium can increase ATP content, mitochondrial membrane potential and maximal respiration rate, and decrease the expression of Drp1 in LPS-treated HUVECs. Meanwhile, hydrogen can ameliorate excessive mitochondrial fission caused by LPS. Furthermore, hydrogen-rich medium had a similar effect to Mdivi-1, a mitochondrial fission blocker. Both of them rescued the up-regulation of Drp1 and mitochondrial fission induced by LPS, then normalized mitochondrial shape after LPS stimulation. But after Znpp pretreatment, HO-1 expression was inhibited and the protective effects of hydrogen were abrogated. ConclusionsHydrogen-rich medium can alleviate the LPS-induced mitochondrial fusion/fission and dysfunction in HUVECs via HO-1 up-regulation.

An oligomeric semiconducting nanozyme with ultrafast electron transfers alleviates acute brain injury.

Artificial enzymes have attracted wide interest in disease diagnosis and biotechnology due to high stability, easy synthesis, and cost effectiveness. Unfortunately, their catalytic rate is limited to surface electron transfer, affecting the catalytic and biological activity. Here, we report an oligomeric nanozyme (O-NZ) with ultrafast electron transfer, achieving ultrahigh catalytic activity. O-NZ shows electron transfer of 1.8 nanoseconds in internal cores and 1.2 picoseconds between core and ligand molecule, leading to ultrahigh superoxidase dismutase–like and glutathione peroxidase–like activity (comparable with natural enzyme, Michaelis constant = 0.87 millimolars). Excitingly, O-NZ can improve the 1-month survival rate of mice with acute brain trauma from 50 to 90% and promote the recovery of long-term neurocognition. Biochemical experiments show that O-NZ can decrease harmful peroxide and superoxide via in vivo catalytic chain reaction and reduce acute neuroinflammation via nuclear factor erythroid-2 related factor 2–mediated up-regulation of heme oxygenase-1 expression.

Inhibitive Effect of Luteolin on Sevoflurane-Induced Neurotoxicity through Activation of the Autophagy Pathway by HMOX1.

Luteolin is a flavone compound occurring in a variety of medicinal plants, which is reported to have neuroprotective properties. In this study, we aimed to explore the effects of luteolin in alleviating sevoflurane-induced neurotoxicity. GeneCards and Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform were employed to screen luteolin, sevoflurane, and neurotoxicity-related genes. Subsequently, we isolated primary neurons from the hippocampus of 1-day-old C57BL/6J mice and tested for cytotoxicity after treatment of different concentrations of luteolin. Next, we measured the expression of apoptosis by flow cytometry and assessed inflammation-related factors, including heme oxygenase-1 expression detected by immunohistochemical staining and neuronal apoptosis. Finally, water maze, open field, and fear conditioning tests were conducted to observe the interaction between luteolin and sevoflurane in cognitive impairment of mice. Luteolin had the lowest cytotoxicity at concentrations of 30 or 60 μg/mL; we selected 30 μg/mL for drug administration experiments in vitro. Luteolin inhibited sevoflurane-induced neuronal apoptosis and inflammatory responses through the autophagic pathway and thus ameliorated sevoflurane-induced cognitive impairment in mice. Mechanistically, luteolin up-regulated heme oxygenase-1 expression, which activated the autophagy pathway in vitro. This was confirmed by subsequent histological experiments in mice and behavioral results showing rescue cognitive impairment. Our findings uncovered an inhibitory role of luteolin in sevoflurane-induced neuronal apoptosis and inflammatory response through activation of autophagy arising from up-regulation of heme oxygenase-1, thereby alleviating sevoflurane-induced cognitive impairment in mice.

MicroRNA-760 resists ambient PM2.5-induced apoptosis in human bronchial epithelial cells through elevating heme-oxygenase 1 expression

PM2.5 (particles matter smaller aerodynamic diameter of 2.5 μm) exposure, a major environmental risk factor for the global burden of diseases, is associated with high risks of respiratory diseases. Heme-oxygenase 1 (HMOX1) is one of the major molecular antioxidant defenses to mediate cytoprotective effects against diverse stressors, including PM2.5-induced toxicity; however, the regulatory mechanism of HMOX1 expression still needs to be elucidated. In this study, using PM2.5 as a typical stressor, we explored whether microRNAs (miRNAs) might modulate HMOX1 expression in lung cells. Systematic bioinformatics analysis showed that seven miRNAs have the potentials to target HMOX1 gene. Among these, hsa-miR-760 was identified as the most responsive miRNA to PM2.5 exposure. More importantly, we revealed a “non-conventional” miRNA function in hsa-miR-760 upregulating HMOX1 expression, by targeting the coding region and interacting with YBX1 protein. In addition, we observed that exogenous hsa-miR-760 effectively elevated HMOX1 expression, reduced the reactive oxygen agents (ROS) levels, and rescued the lung cells from PM2.5-induced apoptosis. Our results revealed that hsa-miR-760 might play an important role in protecting lung cells against PM2.5-induced toxicity, by elevating HMOX1 expression, and offered new clues to elucidate the diverse functions of miRNAs.

MicroRNA-100 Mediates Hydrogen Peroxide-Induced Apoptosis of Human Retinal Pigment Epithelium ARPE-19 Cells.

This study investigated the regulatory role of microRNA 100 (miR-100) in hydrogen peroxide (H2O2)-induced apoptosis of human retinal pigment epithelial ARPE-19 cells. H2O2 induced oxidative cell death of cultured ARPE-19 cells was measured by cytotoxicity assay. qRT-PCR was used to quantify cytosolic and extracellular contents of miR-100. Kinase and miR-100 inhibition treatments were applied to determine the regulatory signaling pathways involved in cell death regulation. H2O2 dose-dependently reduced viability of ARPE-19 cells and simultaneously upregulated miR-100 levels in both cytosolic and extracellular compartments. Western blotting detection indicated that H2O2 elicited hyperphosphorylation of PI3K/Akt, ERK1/2, JNK, p38 MAPK, and p65 NF-κB. Further kinase inhibition experiments demonstrated that PI3K, p38 MAPK, and NF-κB activities were involved in oxidative-stress-induced miR-100 upregulation in ARPE-19 cells, while blockade of PI3K, JNK, and NF-κB signaling significantly attenuated the oxidative cell death. Intriguingly, MiR-100 antagomir treatment exerted a cytoprotective effect against the H2O2-induced oxidative cell death through attenuating the oxidation-induced AMPK hyperphosphorylation, restoring cellular mTOR and p62/SQSTM1 levels and upregulating heme oxygenase-1 expression. These findings support that miR-100 at least in part mediates H2O2-induced cell death of ARPE-19 cells and can be regarded as a preventive and therapeutic target for retinal degenerative disease.

Sevoflurane inhibits ferroptosis: A new mechanism to explain its protective role against lipopolysaccharide-induced acute lung injury

Sevoflurane (Sev) has protective effects in acute lung injury (ALI), but the relevant mechanisms are still not fully understood. The present study aimed to determine whether Sev exerts a protective effect on lipopolysaccharide (LPS)-induced ALI by regulating ferroptosis. In this study, we found that Sev could protect mice from lung injury caused by LPS stimulation, including extenuating lung histological damage, pulmonary edema and pulmonary vascular permeability, and the content of inflammatory factors in Bronchoalveolar lavage fluid (BALF), as well as improving the survival rate of ALI mice, which was in line with the effects of ferroptosis inhibitor ferrostatin-1. Simultaneously, Sev could eliminate the worsening effects of ferroptosis inducer Fe-citrate on LPS-induced ALI to a certain extent. Additionally, the administration of Sev could inhibit ferroptosis caused by LPS, which was manifested by reducing the accumulation of MDA and Fe2+, and increasing the levels of GSH and GPX4 in the lung tissues of ALI mice. It was also observed in BEAS-2B cells that the increased MDA and Fe2+ levels and the decreased GSH and GPX4 levels caused by LPS could be rescued by ferrostatin-1 and Sev. LPS stimulation compensatory up-regulated heme oxygenase-1 (HO-1) expression in mouse lung tissues and BEAS-2B cells, which could be enhanced by Sev. Moreover, HO-1 depletion could offset the inhibitory effect of Sev on LPS-induced ferroptosis and inflammation in BEAS-2B cells. Taken together, Sev inhibited ferroptosis by up-regulating HO-1 expression to reduce LPS-induced ALI, which may provide a possible mechanism for the application of Sev in clinical anesthesia.