H2O2 Treatment Research Articles

Nicotinamide mononucleotide protects STAT1 from oxidative stress-induced degradation to prevent colorectal tumorigenesis.

Colitis, accompanied by the accumulation of reactive oxygen species (ROS) in the intestinal tract, is a risk factor for colorectal cancer (CRC). Our previous studies indicate that nicotinamide mononucleotide (NMN) replenishment reduces chronic inflammation. In this study, we confirm that NMN supplementation reduces inflammatory cytokine levels and oxidative tissue damage in an azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colitis-associated cancer (CAC) model. Mice treated with NMN developed fewer colon tumors than untreated animals under the same AOM/DSS treatment conditions. Quantitative proteomic analysis revealed a decrease in signal transducer and activator of transcription 1 (STAT1) expression in the CAC model. We demonstrate that STAT1 overexpression induces G1 arrest by downregulating CDK6 expression and suppressing tumor cell proliferation and migration. Of note, H2O2 induced trioxidation of the STAT1 protein and promoted its degradation, which was partially reversed by NMN supplementation. Upon H2O2 treatment, Cys155 in STAT1 was oxidized to sulfonic acid, whereas the mutation of Cys155 to alanine abolished ROS-mediated STAT1 degradation. These results indicate that oxidative stress induces STAT1 degradation in tumor cells and possibly in CAC tissues, whereas supplementation with NMN protects STAT1 from oxidation-induced degradation and prevents tumorigenesis. This study provides experimental evidence for the development of NMN-mediated chemoprevention strategies for CRC.

Revitalizing Muscle Regeneration: Cocoa Polyphenols Shield Mitochondrial Integrity and Boost Myogenesis Under Oxidative Stress.

In this study, we describe the effect of cocoa polyphenol extract (CPE, from flavanols-rich cocoa) on myogenic differentiation in murine myoblasts (C2C12 cells) exposed to H2O2. The myogenic program was monitored using morphological, ultrastructural, and molecular approaches. Treatment with 100 μM of H2O2 for 1 h decreased cell viability. C2C12 (D1) exposed to H2O2 shows more apoptotic and necrotic cells, and mitochondria appear emptied, with cristae heavily damaged. To evaluate the effect of CPE on myoblast viability and myotube formation, 10 μg/mL of CPE were added 24 h prior to H2O2 treatment and cells were supplemented with fresh CPE every 24 h during differentiation. Supplementation with CPE protected C2C12 myoblasts from H2O2-induced oxidative damage both at early (D1) and late (D6) phases of differentiation, preventing cell death and mitochondrial damage. The number of mitochondria (per area of cell surface) increased 2-fold in both control and in CPE-supplemented and mitochondria in myotubes D6 showed a greater extension of mitochondrial cristae than mitochondria in D1. At D1 and D6 the monolayers showed surface and inner cell features relatively comparable to the untreated control suggesting that CPE supplementation significantly mitigated the effect of H2O2. Preliminary data obtained by the myogenic index (Giemsa staining) suggested that CPE-supplemented cells were partially protected from H2O2-induced myogenesis inhibition. The CPE supplementation seems to preserve the mitochondrial integrity and the myogenic differentiation ability of oxidatively injured C2C12 ensuing further nutraceutical perspectives.

Hydrogen peroxide priming triggers splicing memory in grape berries.

Plants are highly sensitive to environmental changes, and alternative splicing (AS) has been described in many studies due to its important control role in stress response. Recent studies indicated that plants exhibit splicing memory to stress to effectively activate transcriptional adaptation. Hydrogen peroxide (H2O2), as a reactive oxygen species (ROS), has toxic effects on plants. However, it also has a significant effect on promoting early maturity of 'Kyoho' grape at low concentrations. To explore the mechanism of priming treatment of H2O2 showing better promotion effect, the RNA-Seq data of H2O2-primied and no-primied fruits were analyzed. The genes with H2O2 stress splicing memory were identified, accompanied by changes in H3K4me3 modification levels, and their splicing memory patterns were verified by PCR and agarose gel electrophoresis. This finding establishes a link between alternative splicing memory and fruit ripening under H2O2 regulation and contribute to develop the application of H2O2 in fruit ripening.

Melatonin alleviates oxidative stress and inflammation of Leydig cells of Min pig through SIRT1 pathway

Inflammation responses and oxidative stress adversely affect testicular function, reducing fertility. Melatonin exhibits anti-inflammatory and antioxidant properties. However, the molecular mechanism by which melatonin alleviates inflammation and oxidative stress in Leydig cells of the Min pig testis remains unclear. To investigate this, primary Leydig cells were isolated from 7-day-ld Min pigs' testes and treated with LPS, H2O2 and melatonin, respectively. The results showed that co-treatment with melatonin and LPS significantly decreased the expression of TLR4, NF-κB, IL-6 and IL-1β compared to LPS group. Co-treatment with melatonin and H2O2 significantly mitigated reactive oxygen species and malondialdehyde levels. Melatonin also enhanced glutathione and superoxide dismutase levels and upregulated the mRNA expression levels of Nrf2, Keap1, HO-1 and NQO1. In the co-treatment group of melatonin, LPS, and SIRT1 inhibitor, the secretion of IL-6 and IL-1β and the mRNA expression levels of TLR4 and NF-κB were elevated significantly compared to the control group and the melatonin-LPS co-treatment group. In the combined treatment group of melatonin, H2O2 and a SIRT1 inhibitor, ROS levels increased significantly, while the expression of Nrf2, Keap1, HO-1 and NQO1 were decreased significantly compared to the control group and the melatonin-H2O2 co-treatment group. Furthermore, mRNA expression levels of testosterone synthesis-related genes StAR, CYP11A1, 3β-HSD, CYP17A1 and 17β-HSD significantly decreased following H2O2 treatment, which was alleviated by co-treatment with H2O2 and melatonin, but not by the addition of SIRT1 inhibitor. In conclusion, melatonin exhibits the capability to ameliorate inflammatory responses, oxidative stress and testosterone secretion in Leydig cells via the SIRT1 pathway.

The OXI1 kinase regulates plant immunity by linking microbial pattern-induced ROS burst to MAPK activation.

Plant cell-surface-localized pattern recognition receptors (PRRs) recognize microbial patterns and activate pattern-triggered immunity (PTI). Typical PTI responses include reactive oxygen species (ROS) burst controlled by the NADPH oxidase RESPIRATORY BURST OXIDASE HOMOLOGUE D (RbohD) and activation of the mitogen-activated protein kinase (MAPK) cascade composed of MAPKKK3/5-MKK4/5-MPK3/6. However, the mechanisms through which PRRs regulate and coordinate these immune responses are not fully understood. Here, we showed that Arabidopsis thaliana OXIDATIVE SIGNAL-INDUCIBLE1 (OXI1), a kinase known to be activated by ROS, is involved in the LYK5-CERK1 receptor complex, which recognizes fungal cell wall-derived chitin. The oxi1 mutant exhibits enhanced susceptibility to various pathogens and reduced chitin-induced MAPK activation and ROS burst. We showed that chitin induces the phosphorylation of OXI1 in an RbohD-dependent manner. H2O2 and chitin treatment causes the oxidation of OXI1 at Cys104 and Cys205, which is essential for the kinase activity of OXI1. These oxidation sites are required for chitin-induced MAPK activation and disease resistance. Activated OXI1 directly phosphorylates MAPKKK5 to regulate MAPK activation. Additionally, OXI1 phosphorylates RbohD, suggesting that it may activate RbohD to promote ROS burst to further enhance the long-term MAPK activation. Together, our findings reveal a pathway linking PRR-mediated ROS production to MAPK activation through OXI1.

LncRNA UCA1 enhances NRF2 expression through the m6A pathway to mitigate oxidative stress and ferroptosis in aging cardiomyocytes.

To explore the regulatory mechanism of lncRNA UCA1 and NRF2 in cardiomyocyte aging. In this study, we explored how lncRNA UCA1 regulates NRF2 and its effect on cardiomyocyte aging. H9c2 cardiomyocytes were cultured and treated with H2O2 to simulate cardiomyocyte aging in vitro. The expression levels of lncRNA UCA1 and NRF2 in cells were detected using qRT-PCR. Cell viability was assessed using the CCK8 assay, and cell aging was detected via Sa-β-gal staining. The levels of oxidative stress markers (SOD, MDA, ROS) and the expressions of ferroptosis-related proteins (ACSL4, TFR1, FTH1, GPX4) were measured. The regulatory mechanism between UCA1 and NRF2 was investigated using RIP-qPCR. Additionally, changes in m6A modification levels and the expression of m6A modification-related proteins in cells after UCA1 overexpression were analyzed by western blot. Our results indicate that H2O2 treatment significantly downregulated the expression of lncRNA UCA1 and NRF2. UCA1 overexpression promoted H9c2 cell proliferation, inhibited cell aging, increased SOD activity and the expression of FTH1 and GPX4 proteins, and decreased MDA and ROS content as well as ACSL4 and TFR1 protein expression. RIP-qPCR verified that UCA1 can promote the expression of NRF2 in cells. Overexpression of UCA1 significantly increased the expression of the demethylase FTO, leading to a reduction in m6A modification levels. Furthermore, there was significant enrichment between FTO and NRF2, and overexpression of FTO improved the expression of NRF2 protein in cells. Taken together, lncRNA UCA1 inhibits oxidative stress and ferroptosis, thereby preventing cardiomyocyte aging. This protective effect is likely mediated by increasing the expression of demethylase FTO and reducing m6A modification, which promotes the expression of NRF2.

Functional characterization of peroxiredoxin 5 from yellowtail clownfish (Amphiprion clarkii): Immunological expression assessment, antioxidant activities, heavy metal detoxification, and nitrosative stress mitigation

Peroxiredoxin 5 (Prdx5) is the last recognized member of Prdx family. It is a unique, atypical, 2-Cys antioxidant enzyme, protecting cells from death caused by reactive oxygen species (ROS). In this study, the Prdx5 ortholog of Amphiprion clarkii (AcPrdx5) was identified and characterized to explore its specific structural features and functional properties. The open reading frame of AcPrdx5 is 573 bp long and encodes 190 amino acids containing a mitochondrial targeting sequence, thioredoxin domain, and two conserved cysteine residues responsible for antioxidant function. The predicted molecular weight and theoretical isoelectric point of AcPrdx5 are 20.3 kDa and 9.01, respectively. AcPrdx5 sequences were found to be highly conserved across the other orthologs from various organisms and it distinctively clustered within the fish Prdx5 subclade of the phylogenetic tree. The expression of AcPrdx5 was ubiquitously detected among twelve tested tissues, with the highest level in the brain. Furthermore, the mRNA levels of AcPrdx5 in the blood and head-kidney tissues were significantly (p < 0.05) upregulated following polyinosinic-polycytidylic acid (Poly I:C), lipopolysaccharide (LPS), and Vibrio harveyi immune challenge. A concentration-dependent antioxidant potential of recombinant AcPrdx5 was observed in insulin disulfide bond reduction, heavy metal detoxification, free radical and hydrogen peroxide (H2O2) scavenging assays. Additionally, AcPrdx5 overexpression in fathead minnow (FHM) cells upregulated the antioxidant-associated gene (Rrm1, MAPK, SOD2, and PRDX1) expression after H2O2 treatment, and promoted cell viability upon arsenic (As) exposure. In macrophages, AcPrdx5 overexpression effectively suppressed substantial nitric oxide production under lipopolysaccharide treatment. Collectively, our results suggest that AcPrdx5 may play roles in both antioxidant defense system and innate immune response against pathogenic invasions in A. clarkii.

MiR-204-5p regulates SIRT1 to promote the endoplasmic reticulum stress-induced apoptosis of inner ear cells in C57BL/6 mice with hearing loss.

This study investigated the effect of miR-204-5p-mediated silencing of SIRT1 on the development of deafness in C57BL/6 mice and the roles of miR-204-5p and SIRT1 in deafness. Auditory brainstem response recordings, H&E staining, and immunohistochemistry were used to observe changes in hearing function and cochlear tissue morphology in 2-month-old and 15-month-old C57BL/6 mice. A senescence model was induced using H2O2 in inner ear cells (HEI-OC1). Changes in HEI-OC1 cell proliferation were detected using the CCK-8 assay, whereas flow cytometry was used to detect changes in apoptosis. MiR-204-5p expression was measured via RT‒qPCR. The SIRT1 agonist RSV and a miR-204-5p inhibitor were used to study changes in ER stress (ERS), proliferation, and apoptosis in HEI-OC1 cells. Western blotting was performed to detect changes in ATF4, CHOP, SIRT1, PERK, p-PERK, Bax, and Bcl-2 protein levels. A dual-luciferase reporter gene assay was carried out to assess the ability of miR-204-5p to target SIRT1. Relative miR-204-5p expression levels in the cochleae of aged C57BL/6 mice increased, whereas SIRT1 expression levels decreased, and miR-204-5p and SIRT1 expression levels were negatively correlated. ERS and increased 8-OHDG levels were observed in aged C57BL/6 mice. In a model of inner ear cell aging, H2O2 treatment induced increases in miR-204-5p expression and ERS-mediated apoptosis. MiR-204-5p was found to target SIRT1 and inhibit its expression. SIRT1 activation and a miR-204-5p inhibitor promoted HEI-OC1 cell proliferation and reduced apoptosis. The miR-204-5p inhibitor regulated expression of the ERS proteins PERK, ATF4, and CHOP to upregulate Bcl-2 and downregulate Bax. This study identified the roles of miR-204-5p and SIRT1 in deafness in C57BL/6 mice and investigated the loss of cochlear outer hair cells and the involvement of apoptosis and ERS in deafness.

Rivaroxaban as a protector of Oxidative Stress-induced Vascular Endothelial Glycocalyx Damage via The IQGAP1/PAR1-2/PI3K/Akt Pathway.

The vascular endothelial glycocalyx, crucial for blood vessel integrity and homeostasis, is vulnerable to oxidative stress, leading to endothelial dysfunction, which strongly correlates with cardiovascular disease (CVD). This study investigates the protective effects of rivaroxaban, a FXa inhibitor, on the glycocalyx under oxidative stress condition. We examined the impact of rivaroxaban on human umbilical vein endothelial cells (HUVECs) exposed to acute and chronic H₂O₂-induced oxidative stress. Rivaroxaban dose-dependently suppressed syndecan-1, a key component of the glycocalyx, shedding from cell surface, and enhanced protease-activated receptor (PAR)1-PAR2/ phosphatidylinositol-3-kinase (PI3K)-dependent cell viability after acute induction of H2O2. This protective effect was linked to the translocation of IQGAP1, a scaffold protein that modulates the actin cytoskeleton, to the perinucleus from the cell membrane. Under chronic H2O2 treatments, rivaroxaban improves cell viability accompanied by an increase in hyaluronidase activities, aiding the turnover and remodeling of hyaluronic acid within the glycocalyx. We identify that rivaroxaban protects against oxidative stress-induced endothelial glycocalyx damage and cell viability through IQGAP1/PAR1-2/PI3K/Akt pathway, offering a potential to be a therapeutic target for CVD prevention.

Unveiling abiotic stress-induced cell death modalities in the heterocytous cyanobacterium Anabaena sp. PCC 7120

Regulated cell death (RCD) in cyanobacteria is a post-stress phenomenon necessary for stress adaptability and eco-physiology. However, the sequential modulations in cellular processes conferring regulated forms of death remained elusive. In this study, we evaluated morpho-physiological and biochemical determinants of cell death in a time-dependent manner to understand the sequential cellular events during the process. The death was instigated by exposing heterocytous cyanobacterium Anabaena sp. PCC 7120 to 1mM H2O2, 250mM NaCl and sulfur-starvation. A significant changes in the sequences of morpho-physiological and biochemical events were observed in different stress conditions. Upon H2O2 treatment rapid oxidation of cytosol and disintegration of cell envelop was observed prior to DNA fragmentation. On the other hand, salt-stress and sulfur-deprivation induced phosphatidylserine (PS) externalisation, gradual rise in redox potential, and DNA fragmentation prior to membrane disintegration. Furthermore, we analysed the time-dependent expression of five orthocaspases, the putative executioner of cyanobacterial cell death. Out of five, only two orthocaspases anaOC2 and anaOC6 exhibit expression pattern synergistic and coherent with DNA fragmentation in salt treated and sulfur-deficient cells. However, no orthocaspases expression was evident during H2O2 treatment. Considering these parameters, H2O2 induced death was regarded as accidental cell death (ACD), whereas in salt and sulfur stresses mediated two different RCD subroutines, which were orthocaspases-dependent. Overall for the first time, we demonstrated the existence of three death modalities in cyanobacteria based on sequential cellular events and relative expression of orthocaspases.

H2O2-mediated cell wall remodeling and pectin demethylesterification are involved in maintaining postharvest texture of table grape by sulfur dioxide

Berry texture affects consumer acceptance and postharvest shelf life of table grapes. This study elucidates how sulfur dioxide (SO2) treatment maintains grape texture quality, focusing on the role of hydrogen peroxide (H2O2)-mediated cell wall modifications. SO2 treatment exhibited effects similar to those of H2O2 treatment, resulting in firmer berries with more intact cell wall structures, higher contents of chelate-soluble pectin, sodium carbonate-soluble pectin, hemicellulose, and cellulose, with lower levels of water-soluble pectin compared to untreated fruit. Moreover, it delays pectin nanostructure disassembly and reduces degree of pectin methylesterification, which facilitates the formation of calcium bridges between demethylesterified pectin and increased calcium ions, thereby strengthening the cell wall and weakening enzymatic pectin degradation. Conversely, combining ROS generation inhibitors with SO2 mitigated these effects. Overall, these findings highlight the role of H2O2-mediated cell wall modification in maintaining grape postharvest texture through SO2 treatment, providing new insights for managing grape postharvest softening.

SydR, a redox-sensing MarR-type regulator of Sinorhizobium meliloti, is crucial for symbiotic infection of Medicago truncatula roots.

Rhizobia associate with legumes and induce the formation of nitrogen-fixing nodules. The regulation of bacterial redox state plays a major role in symbiosis, and reactive oxygen species produced by the plant are known to activate signaling pathways. However, only a few redox-sensing transcriptional regulators (TRs) have been characterized in the microsymbiont. Here, we describe SydR, a novel redox-sensing TR of Sinorhizobium meliloti that is essential for the establishment of symbiosis with Medicago truncatula. SydR, a MarR-type TR, represses the expression of the adjacent gene SMa2023 in growing cultures, and this repression is alleviated by NaOCl, tert-butyl hydroperoxide, or H2O2 treatment. Transcriptional psydR-gfp and pSMa2023-gfp fusions, as well as gel shift assays, showed that SydR binds two independent sites of the sydR-SMa2023 intergenic region. This binding is redox-dependent, and site-directed mutagenesis demonstrated that the conserved C16 is essential for SydR redox sensing. The inactivation of sydR did not alter the sensitivity of S. meliloti to NaOCl, tert-butyl hydroperoxide, or H2O2, nor did it affect the response to oxidants of the roGFP2-Orp1 redox biosensor expressed within bacteria. However, in planta, ΔsydR mutation impaired the formation of root nodules. Microscopic observations and analyses of plant marker gene expression showed that the ΔsydR mutant is defective at an early stage of the bacterial infection process. Altogether, these results demonstrated that SydR is a redox-sensing MarR-type TR that plays a key role in the regulation of nitrogen-fixing symbiosis with M. truncatula.IMPORTANCEThe nitrogen-fixing symbiosis between rhizobia and legumes has an important ecological role in the nitrogen cycle, contributes to nitrogen enrichment of soils, and can improve plant growth in agriculture. This interaction is initiated in the rhizosphere by a molecular dialog between the two partners, resulting in plant root infection and the formation of root nodules, where bacteria reduce the atmospheric nitrogen into ammonium. This symbiosis involves modifications of the bacterial redox state in response to reactive oxygen species produced by the plant partner. Here, we show that SydR, a transcriptional regulator of the Medicago symbiont Sinorhizobium meliloti, acts as a redox-responsive repressor that is crucial for the development of root nodules and contributes to the regulation of bacterial infection in S. meliloti/Medicago truncatula symbiotic interaction.

OSBPL2 inhibition leads to apoptosis of cochlea hair cells in age-related hearing loss by inhibiting the AKT/FOXG1 signaling pathway.

Age-related hearing loss (AHL) is a prevalent and multifaceted condition that significantly impacts a substantial portion of the aging population. Oxysterol Binding Protein-like 2 (OSBPL2) has been identified as a causal gene for hearing loss. However, its role in AHL is still unclear. In this study, we investigated the effect of OSBPL2 on the survival of cochlea hair cells. To simulate AHL in vitro, hair cell-like inner ear cells (HEI-OC1) were exposed to H2O2 treatment. OSBPL2 expression was significantly increased in HEI-OC1 cells after H2O2 treatment. OSBPL2 knockdown augmented cell death and apoptosis in H2O2-induced HEI-OC1 cells. Besides, H2O2 treatment also led to the inactivation of the AKT and FOXG1 signaling pathways in HEI-OC1 cells. Mechanistically, OSBPL2 silencing reinforced the inactivation of the FOXG1 signaling pathway in H2O2-treated HEI-OC1 cells by inhibiting the AKT signaling pathway. Under H2O2 treatment, AKT inhibition by MK2206 augmented the apoptosis of HEI-OC1 cells; on the contrary, AKT activation by SC79 treatment partially rescued the apoptosis of OSBPL2-knockdown HEI-OC1 cells. In addition, FOXG1 silencing significantly reversed the effects of AKT activation on OSBPL2-knockdown HEI-OC1 cells. Moreover, OSBPL2 expression and the activation status of the AKT/FOXG1 signaling pathway were confirmed in the cochleae of young and old C57BL/6 mice. In conclusion, our study provides evidence that OSBPL2 inhibition sensitizes HEI-OC1 cells to H2O2-induced apoptosis via inactivation of the AKT/FOXG1 signaling pathway, suggesting that OSBPL2 acts as an important regulator in AHL.

Mild and efficient approach to aromatic backbone cleavage using copper-lignosulfonate/hydrogen peroxide system

This study investigates the dual role of copper ions in catalysis and complexation during the oxidation of lignosulfonates with hydrogen peroxide (H2O2) under alkaline conditions. The presence of copper ions reduces partial oxidation by 86 % compared to H2O2 treatment alone, enhancing overall conversion efficiency to 63 % under increased oxidative conditions. Analyses reveal that copper-lignosulfonate complexes facilitate redox cycling and hydroxyl radical generation through interactions with H2O2, confirming copper’s dual functions. This mechanism mitigates the hindrance of sulfonic groups on hydroperoxide anions, leading to lignosulfonate degradation into dicarboxylic acids. These findings provide novel insights into the copper-lignosulfonate/H2O2 system, expanding the understanding of oxidative degradation mechanisms beyond traditional Fenton-like reactions. Furthermore, this system offers a simplified and efficient alternative for industrial applications, particularly in integration with the sulfite pretreatment process of woody biomass for producing valuable co-products.

Supplementation of Chlorogenic Acid Alleviates the Effects of H2O2-Induced Oxidative Stress on Laying Performance, Egg Quality, Antioxidant Capacity, Hepatic Inflammation, Mitochondrial Dysfunction, and Lipid Accumulation in Laying Hens.

This research examined the impact of chlorogenic acid (CGA) on laying performance, antioxidant capacity, egg quality, hepatic inflammation, mitochondrial function, and lipid metabolism in hens subjected to hydrogen peroxide (H2O2)-induced oxidative stress (OS). Three hundred sixty healthy 43-wk-old Hy-Line brown hens were randomly assigned to six treatments: a basal diet + 0 (control and H2O2), 600 (600 mg/kg CGA and 600 mg/kg CGA + H2O2), and 800 (800 mg/kg CGA and 800 mg/kg CGA + H2O2) mg/kg CGA for 84 d. On the 64th and 78th days of the trial, hens in groups H2O2, 600 mg/kg CGA + H2O2, and 800 mg/kg CGA + H2O2 were injected intraperitoneally with 10% H2O2. The results demonstrated that 600 and 800 mg/kg CGA significantly improved the egg production rate (EPR) and egg quality and reduced lipid peroxidation compared to the control group. The 800 mg/kg CGA showed greater improvements in the EPR and average egg weight (AEW) compared to the 600 mg/kg dose. Conversely, H2O2 exposure significantly decreased the EPR, AEW, and egg quality and increased feed conversion rate and average daily feed intake. H2O2 exposure significantly decreased serum T-AOC and increased serum MDA levels while reducing hepatic T-SOD, GSH-Px, and CAT activities. Meanwhile, H2O2 exposure significantly elevated liver reactive oxygen species levels, pathological damage, and NF-κB, TNFα, and IL-1β gene expression. Additionally, H2O2 treatment disrupted hepatocyte mitochondrial structure and significantly increased the expression of VDAC1 protein, and IP3R, GRP75, MCU, Fis1, and MFF genes, while downregulating the expression of MFN2 protein and PGC1α gene. Oil Red O staining demonstrated that H2O2 induced significant lipid accumulation in hepatocytes. Concurrently, H2O2 significantly increased serum triglycerides, total cholesterol, and liver triglycerides levels while decreasing serum hepatic lipase activity. This was primarily attributed to the significant upregulation of liver SREBP1, FASN, and ACC genes and the downregulation of the liver CPT1 gene induced by H2O2. Furthermore, CGA pretreatment effectively prevented the degeneration in laying performance and egg quality, as well as OS, liver inflammation, pathological damage, and mitochondrial dysfunction induced by H2O2. CGA inhibited H2O2-induced hepatic lipid accumulation by upregulating fatty acid oxidation-related gene expression and downregulating fatty acid synthesis-related gene expression. These findings indicate that the dietary addition of 800 mg/kg of CGA is the optimum supplementation dose. CGA can enhance laying performance and egg quality while alleviating OS, hepatic inflammation, mitochondrial dysfunction, and lipid accumulation in H2O2-challenged laying hens.

Chemical composition of anti-microbially active fractions derived from extract of filamentous fungus Keratinophyton Lemmensii including three novel bioactive compounds

Screening for new bioactive microbial metabolites, we found a novel okaramine derivative, for which we propose the trivial name lemmokaramine, as well as two already known okaramine congeners – okaramine H and okaramine J - responsible for antimicrobial activity of the recently described microscopic filamentous fungus, Keratinophyton lemmensii BiMM-F76 (= CCF 6359). In addition, two novel substances, a new cyclohexyl denominated lemmensihexol and a new tetrahydroxypyrane denominated lemmensipyrane, were purified and characterized. The compounds were isolated from the culture extract of the fungus grown on modified yeast extract sucrose medium by means of flash chromatography followed by preparative HPLC. The chemical structures were elucidated by NMR and LC-MS. The new okaramine (lemmokaramine) exerted antimicrobial activity against Gram-positive and Gram-negative bacteria, yeasts and fungi and anticancer activity against different mammalian cell lines (Caco-2, HCT116, HT29, SW480, MCM G1, and MCM DLN). Furthermore, we found a significant antioxidant effect of lemmokaramine following H2O2 treatment indicated by activation of the Nrf2 pathway. This is the first report describing analysis and structural elucidation of bioactive metabolites for the onygenalean genus Keratinophyton.

Remarkable Stability of Glutathione-Based Supramolecular Gel in the Presence of Oxidative Stress from Hydrogen Peroxide.

Low molecular weight 7-methoxy-3-(p-nitrophenyl)iminocoumarin (MNI) with donor and acceptor groups has been synthesized. The molecule shows typical π-stacking geometry in the crystal structure. In this study, MNI, an achiral small organic molecule, forms a nanostructured supramolecular gel along with a short peptide sequence glutathione (GSH). The self-assembly of the achiral organic coumarin component and chiral biomolecule produces a chiral gel with helical fiber structures. Interestingly, the helicities of chiral gels are controlled by the solvent ratio, where MNI in DMSO and GSH in water has been used. Variation of the solvent ratio from 6:4 to 1:9 for DMSO:H2O results in six gels (4, 5, 6, 7, 8 and 9), where the gel numbers signify the water content ratio. FE-SEM analysis shows gel fibers with right-handed helical structures, which have been further confirmed by circular dichroism (CD) with notable helicity in 4 to 6. This is the first report of controlled chiral helical nanostructured supramolecular gel formation by a solvent mixture with an organic small molecule and biomolecule. Interestingly, storage modulus (G') initially decreases from 4 to 6 and further increases up to 9. An opposite strain (%) trend was observed among these six gels. These unusual solvent-dependent gel properties have been further applied to monitor the stability of the gels in the presence of hydrogen peroxide (H2O2), which converts GSH to oxidized glutathione (GSSG) in general. The oxidative stress from H2O2 disrupts 4 to 6 gels, and precipitation occurs. It is noteworthy to mention that GSSG alone cannot form a gel with the MNI molecule and forms a precipitate. Remarkably, on the other hand, 7 to 9 remain as strong gels even after H2O2 treatment. Among all six gels, 9 shows extraordinary stability of gels even after H2O2 treatment.

PFKFB3 ameliorates ischemia-induced neuronal damage by reducing reactive oxygen species and inhibiting nuclear translocation of Cdk5.

The enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB) plays an essential role in glycolysis and in the antioxidant pathway associated with glutathione. Therefore, we investigated the effects of PFKFB3 on oxidative and ischemic damage. We synthesized a fusion protein of transactivator of transcription (Tat)-PFKFB3 to facilitate its passage into the intracellular space and examine its effects against oxidative stress induced by hydrogen peroxide (H2O2) treatment and ischemic damage caused by occlusion of the common carotid arteries for 5min in gerbils. The Tat-PFKFB3 protein was efficiently delivered into HT22 cells in a concentration- and time-dependent manner, with higher levels observed 18h after treatment. Furthermore, treatment with 6 µM Tat-PFKFB3 demonstrated intracellular delivery into HT22 cells, as analyzed through immunocytochemical staining. Moreover, it significantly ameliorated the reduction of cell viability induced by 200 µM H2O2 treatment. Tat-PFKFB3 treatment also alleviated H2O2-induced DNA fragmentation and reactive oxygen species formation in HT22 cells. In gerbils, the intraperitoneal administration of 2mg/kg Tat-PFKFB3 efficiently delivered the substance to all hippocampal areas, including the hippocampal CA1 region. This administration significantly mitigated ischemia-induced hyperlocomotion, long-term memory deficits, and ischemic neuronal death in the hippocampal CA1 region after ischemia. Additionally, treatment with 2mg/kg Tat-PFKFB3 significantly ameliorated the translocation of Cdk5 from the cytosol to the nucleus in the hippocampal CA1 region 24h after ischemia, but not in other regions. The treatment also significantly reduced reactive oxygen species formation in the CA1 region. These findings suggest that Tat-PFKFB3 reduces neuronal damage in the hippocampal CA1 region after ischemia through the reduction of Cdk5 signaling and reactive oxygen species formation. Therefore, Tat-PFKFB3 may have potential applications in reducing ischemic damage.

Effect of Oxidative Stress on Sperm TERRA Expression and Chromatin Function in Infertile Males: A Preliminary Finding

Telomeres are vital for cellular function. Oxidative stress is detrimental to telomere function as it causes telomere attrition. Increase in oxidative stress has a negative impact on sperm telomere and chromatin integrity and therefore, on sperm function and male fertility. TERRA, a long non-coding RNA is a fundamental component required for telomere length homeostasis. Aim: The present work aimed to study the effect of H2O2 induced oxidative stress on sperm TERRA expression and chromatin function. Methodology: 5 infertile and 5 fertile males were selected for the study. Baseline semen analysis was done as per WHO manual 2021. Sperm TERRA expression was assessed by real time qPCR. To assess chromatin function nuclear chromatin decondensation test was done. Results: Study showed that 500µM H2O2 increased TERRA expression as compared to untreated groups and the difference was found to be statistically significant. As compared to controls, cases showed more fold increase in TERRA expression. When treated samples of control and cases were compared, cases had more TERRA expression than controls however, the baseline TERRA expressions in untreated samples were less in cases as compared to controls. Both comparisons yielded statistically nonsignificant results. When nuclear chromatin decondensation was compared before and after H2O2 treatment, the percentage of sperm head decondensation decreased in both cases and controls. When treated and untreated samples of cases and controls were compared, the difference was statistically nonsignificant. Conclusion: Oxidative stress led to an increase in the expression of sperm TERRA and had a negative impact on nuclear chromatin decondensation. Similar studies with greater sample size can provide much more insight into TERRA mediated regulation of telomere function and chromatin integrity and how it is affected by oxidative stress.

αB-crystallin mini-peptides support corneal healing in vitro and in vivo in rabbit model.

To evaluate if topical use of αB-crystallin mini-peptides supports corneal healing following flap surgery. Cultured corneal cells were treated with fluorescent tagged αB-crystallin mini-peptides to assess its internalization. Cultured corneal cells pre-treated with or without the mini-peptides were exposed to H2O2 and cell viability was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Elongation of neurites of cultured trigeminal neurones was examined following treatment either with αB-crystallin mini-peptides or protein. Cultured trigeminal neurones were pre-treated either with αB-crystallin mini-peptides or crystallin protein and exposed to H2O2 and presence of beading in the dendrites and axons was assessed. Corneal flap surgery was conducted on rabbit cornea and treated topically either with αB-crystallin peptide (0.5 mg/mL thrice daily for 14d) or phosphate-buffered saline (PBS). Corneal healing was evaluated under slit-lamp biomicroscope, mRNA expression of inflammatory cytokines were assessed and the corneas were evaluated by histopathology. Internalization of αB-crystallin mini-peptides was ascertained by the detection of fluorescence within the corneal cells. The MTT assay revealed that treatment with αB-crystallin mini-peptide reduced cell death induced by H2O2 treatment. The mini-peptides did not influence the elongation of trigeminal neurites, but significantly (P<0.05) reduced beading in the neurites. In rabbit eye, the treated corneas showed reduced hyper-reflective zones (P<0.05) and suppression in the expression of inflammatory cytokines. Histopathological examination also revealed reduction of inflammatory response in treated corneas. The αB-crystallin mini-peptides restrict the damage to corneal cells and neurons and aids in corneal healing.