Neuroretinal Cell Culture Model as a Tool for the Development of New Therapeutic Approaches for Oxidative Stress-Induced Ocular Diseases, with a Focus on Glaucoma.

Glaucoma is a heterogeneous group of optic neuropathies characterized by a progressive degeneration of the retinal ganglion cells (RGCs), leading to irreversible vision loss. Nowadays, the traditional therapeutic approach to glaucoma consists of lowering the intraocular pressure (IOP), which does not address the neurodegenerative features of the disease. Besides animal models of glaucoma, there is a considerable need for in vitro experimental models to propose new therapeutic strategies for this ocular disease. In this study, we elucidated the pathological mechanisms leading to neuroretinal R28 cell death after exposure to glutamate and hydrogen peroxide (H2O2) in order to develop new therapeutic approaches for oxidative stress-induced retinal diseases, including glaucoma. We were able to show that glutamate and H2O2 can induce a decrease in R28 cell viability in a concentration-dependent manner. A cell viability of about 42% was found after exposure to 3 mM of glutamate and about 56% after exposure to 100 µM of H2O2 (n = 4). Label-free quantitative mass spectrometry analysis revealed differential alterations of 193 and 311 proteins in R28 cells exposed to 3 mM of glutamate and 100 µM of H2O2, respectively (FDR < 1%; p < 0.05). Bioinformatics analysis indicated that the protein changes were associated with the dysregulation of signaling pathways, which was similar to those observed in glaucoma. Thus, the proteomic alteration induced by glutamate was associated with the inhibition of the PI3K/AKT signaling pathway. On the other hand, H2O2-induced toxicity in R28 cells was linked to the activation of apoptosis signaling and the inhibition of the mTOR and ERK/MAPK signaling pathways. Furthermore, the data show a similarity in the inhibition of the EIF2 and AMPK signaling pathways and the activation of the sumoylation and WNT/ß-catenin signaling pathways in both groups. Our findings suggest that the exposure of R28 cells to glutamate and H2O2 could induce glaucoma-like neurodegenerative features and potentially provide a suitable tool for the development of new therapeutic strategies for retinal diseases.

Sodium arsenite and arsenic trioxide differently affect the oxidative stress of lymphoblastoid cells: An intricate crosstalk between mitochondria, autophagy and cell death.

Although the toxicity of arsenic depends on its chemical forms, few studies have taken into account the ambiguous phenomenon that sodium arsenite (NaAsO2) acts as a potent carcinogen while arsenic trioxide (ATO, As2O3) serves as an effective therapeutic agent in lymphoma, suggesting that NaAsO2 and As2O3 may act via paradoxical ways to either promote or inhibit cancer pathogenesis. Here, we compared the cellular response of the two arsenical compounds, NaAsO2 and As2O3, on the Burkitt lymphoma cell model, the Epstein Barr Virus (EBV)-positive P3HR1 cells. Using flow cytometry and biochemistry analyses, we showed that a NaAsO2 treatment induces P3HR1 cell death, combined with drastic drops in ΔΨm, NAD(P)H and ATP levels. In contrast, As2O3-treated cells resist to cell death, with a moderate reduction of ΔΨm, NAD(P)H and ATP. While both compounds block cells in G2/M and affect their protein carbonylation and lipid peroxidation, As2O3 induces a milder increase in superoxide anions and H2O2 than NaAsO2, associated to a milder inhibition of antioxidant defenses. By electron microscopy, RT-qPCR and image cytometry analyses, we showed that As2O3-treated cells display an overall autophagic response, combined with mitophagy and an unfolded protein response, characteristics that were not observed following a NaAsO2 treatment. As previous works showed that As2O3 reactivates EBV in P3HR1 cells, we treated the EBV- Ramos-1 cells and showed that autophagy was not induced in these EBV- cells upon As2O3 treatment suggesting that the boost of autophagy observed in As2O3-treated P3HR1 cells could be due to the presence of EBV in these cells. Overall, our results suggest that As2O3 is an autophagic inducer which action is enhanced when EBV is present in the cells, in contrast to NaAsO2, which induces cell death. That's why As2O3 is combined with other chemicals, as all-trans retinoic acid, to better target cancer cells in therapeutic treatments.

Effect of fluoride or chitosan toothpaste and at-home bleaching in enamel roughness, tooth color, and staining susceptibility.

PURPOSE: To evaluate how fluoride- or chitosan-based toothpaste used during at-home bleaching affects enamel roughness, tooth color, and staining susceptibility. METHODS: Bovine enamel blocks were submitted to a 14-day cycling regime considering a factorial design (bleaching agent x toothpaste, 2 x 3), with n=10: (1) bleaching with 16% carbamide peroxide (CP) or 6% hydrogen peroxide (HP), and (2) daily exposure of a fluoride (1,450 ppm F-NaF) toothpaste (FT), chitosan-based toothpaste (CBT), or distilled water (control). Then, 24 hours after the last day of bleaching procedure the samples were exposed to a coffee solution. Color (ΔEab, ΔE00, L*, a*, b*) and roughness (Ra, µm) analyses were performed to compare the samples initially (baseline), after bleaching, and after coffee staining. The results were evaluated by linear models for repeated measures (L*, a*, b*, and Ra), 2-way ANOVA (ΔEab, ΔE00) and Tukey's test (α= 0.05). RESULTS: After the at-home bleaching procedure (toothpaste vs. time, P< 0.0001), the toothpaste groups presented a statistically lower Ra than the control (CBT 0.05). After coffee exposure, CBT presented lower ΔEab and ΔE00 values in the HP groups (toothpaste, P< 0.0001), and lower b* and a* values in the CP groups (toothpaste vs. time, P= 0.004). CLINICAL SIGNIFICANCE: Fluoride or chitosan delivered by toothpaste can reduce surface alterations of the enamel during at-home bleaching, without affecting bleaching efficacy.

Increasing the radiation-induced cytotoxicity by silver nanoparticles and docetaxel in prostate cancer cells.

BACKGROUND: Radiation therapy is utilized for treatment of localized prostate cancer. Nevertheless, cancerous cells frequently develop radiation resistance. While higher radiation doses have not always been effective, radiosensitizers have been extensively studied for their ability to enhance the cytotoxic effects of radiation. So, this study aims to evaluate the possible radiosensitization effects of docetaxel (DTX) and silver nanoparticles (SNP) in LNCaP cells. METHODS: The cytotoxic effects of DTX, SNP and 2 Gy of X-Ray radiation treatments were assessed in human LNCaP cell line using the MTT test after 24 h. Moreover, the effects of DTX, SNP and radiation on Epidermal growth factor (EGF), Caspase 3, inducible nitric oxide synthase and E-cadherin gene expression were analyzed using the Real-time PCR method. The level of Hydrogen peroxide (H2O2), an oxidative stress marker, was also detected 24 h after various single and combined treatments. RESULTS: The combinations of SNP (in low toxic concentration) and/or DTX (0.25× IC50 and 0.5 × IC50 concentrations for triple and double combinations respectively) with radiation induced significant cytotoxicity in LNCaP cells in comparison to monotherapies. These cytotoxic effects were associated with the downregulation of EGF mRNA. Additionally, H2O2 levels increased after Radiation + SNP + DTX triple combination and double combinations including Radiation + SNP and Radiation + DTX versus single treatments. The triple combination treatment also increased Caspase 3 and and E-cadherin mRNA levels in compared to single treatments in LNCaP cells. CONCLUSION: Our results indicate that the combination of SNP and DTX with radiation induces significant anti-cancer effects. Upregulation of Caspase 3 and E-cadherin gene expression, and decreased mRNA expression level of EGF may be exerted specifically by use of this combination versus single treatments.

Neuroprotective and immunomodulatory effects of superoxide dismutase on SH-SY5Y neuroblastoma cells and RAW264.7 macrophages.

Superoxide dismutase (SOD) is an antioxidant enzyme that protects the body from free radicals. It has both antioxidant and immunomodulatory properties, inducing macrophage polarization from M1 to M2. Macrophages, key mediators of the innate immune response, are divided into the M1 (pro-inflammatory) and M2 (anti-inflammatory) subtypes. In this study, we aimed to assess the antioxidant and neuroprotective effects of SOD on nerve cells and its immunomodulatory effects on macrophages. We observed that SOD inhibited the accumulation of reactive oxygen species and enhanced the viability of H2O2-treated nerve cells. Furthermore, SOD reduced the degree of necrosis in nerve cells treated with the conditioned medium from macrophages, which induced inflammation. In addition, SOD promoted the M1 to M2 transition of macrophages. Our findings suggest that SOD protects nerve cells and regulates immune responses.

Enhanced catalytic activity of Fe3O4-carbon dots complex in the Fenton reaction for enhanced immunotherapeutic and oxygenation effects.

Tumor metastasis and recurrence are closely related to immune escape and hypoxia. Chemodynamic therapy (CDT), photodynamic therapy (PDT), and photothermal therapy (PTT) can induce immunogenic cell death (ICD), and their combination with immune checkpoint agents is a promising therapeutic strategy. Iron based nanomaterials have received more and more attention, but their low Fenton reaction efficiency has hindered their clinical application. In this study, Fe3O4-carbon dots complex (Fe3O4-CDs) was synthesized, which was modified with ferrocenedicarboxylic acid by amide bond, and crosslinked into Fe3O4-CDs@Fc nano complex. The CDs catalyzed the Fenton reaction activity of Fe3O4 by helping to improve the electron transfer efficiency, extended the reaction pH condition to 7.4. The Fe3O4-CDs@Fc exhibit exceptional optical activity, achieving a thermal conversion efficiency of 56.43 % under 808 nm light and a photosensitive single-line state oxygen quantum yield of 33 % under 660 nm light. Fe3O4-CDs@Fc improved intracellular oxygen level and inhibited hypoxia-inducing factor (HIF-1α) by in-situ oxygen production based on Fenton reaction. The multimodal combination of Fe3O4-CDs@Fc (CDT/PDT/PTT) strongly induced immune cell death (ICD). The expression of immune-related protein and HIF-1α was investigated by immunofluorescence method. In vivo, Fe3O4-CDs@Fc combined with immune checkpoint blocker (antibody PD-L1, αPD-L1) effectively ablated primary tumors and inhibited distal tumor growth. Fe3O4-CDs@Fc is a promising immune-antitumor drug.

Molecular characterization, immune functions and DNA protective effects of peroxiredoxin-1 gene in Antheraea pernyi.

Peroxiredoxins are antioxidant proteins that detoxify peroxynitrite, hydrogen peroxide, and organic hydroperoxides, impacting various physiological processes such as immune responses, apoptosis, cellular homeostasis, and so on. In the present study, we identified and characterized peroxiredoxin 1 from Antheraea pernyi (thereafter designated as ApPrx-1) that encodes a predicted 195 amino acid residue protein with a 21.8 kDa molecular weight. Quantitative real-time PCR analysis revealed that the mRNA level of ApPrx-1 was highest in the hemocyte, fat body, and midgut. Immune-challenged larval fat bodies and hemocytes showed increased ApPrx-1 transcript. Moreover, ApPrx-1 expression was induced in hemocytes and the whole body of A. pernyi following exogenous H2O2 administration. A DNA cleavage assay performed using recombinant ApPrx-1 protein showed that rApPrx-1 protein manifests the ability to protect supercoiled DNA damage from oxidative stress. To test the rApPrx-1 protein antioxidant activity, the ability of the rApPrx-1 protein to remove H2O2 was assessed in vitro using rApPrx-1 protein and DTT, while BSA + DDT served as a control group. The results revealed that ApPrx-1 can efficiently remove H2O2 in vitro. In the loss of function analysis, we found that ApPrx-1 significantly increased the levels of H2O2 in ApPrx-1-depleted larvae compared to the control group. We also found a significantly lower survival rate in the larvae in which ApPrx-1 was knocked down. Interestingly, the antibacterial activity was significantly higher in the ApPrx-1 depleted larvae, compared to the control. Collectively, evidence strongly suggests that ApPrx-1 may regulate physiological activities and provides a reference for further studies to validate the utility of the key genes involved in reliving oxidative stress conditions and regulating the immune responses of insects.

A small-molecule Fenton reagent for self-augmented chemodynamic therapy by intelligently regulating intracellular acidosis.

A small-molecule Fenton reagent, integrating ferrocene with a carbonic anhydrase inhibitor, was designed to intelligently regulate intracellular acidosis for self-augmented chemodynamic therapy. Acidosis coupled with up-regulated ROS levels demonstrated potent cytotoxicity and effective tumor suppression.

miRNA-142-3p aggravates hydrogen peroxide-induced human umbilical vein endothelial cell premature senescence by targeting SIRT1.

Vascular endothelial cell premature senescence plays an important part in stroke. Many microRNAs (miRNAs) are known to be involved in the pathological process of vascular endothelial cell premature senescence. The present study aimed to investigate the mechanism of hydrogen peroxide (H2O2)-induced premature senescence in human umbilical vein endothelial cells (HUVECs) and effect of miR-142-3p on hydrogen peroxide (H2O2)-induced premature senescence. HUVECs were exposed to H2O2 to establish a model premature senescence in endothelial cells. CCK-8 assay was performed to detect cell viability. Senescence-associated ß-galactosidase staining assay and senescence-related proteins p16 and p21 were used to detect changes in the degree of cell senescence. RT-qPCR and Western blot were conducted to measure mRNA and protein levels, respectively. The scratch wound-healing assay, transwell assay, and EdU assay were performed to evaluate the ability of migration and proliferation, respectively. miRNA-142-3p and silencing information regulator 2 related enzyme 1 (SIRT1) binding was verified using Targetscan software and a dual-luciferase assay. We found that miRNA-142-3p is abnormally up-regulated in HUVECs treated with H2O2. Functionally, miRNA-142-3p inhibition may mitigate the degree of HUVEC senescence and improve HUVEC migration and proliferation. Mechanistically, SIRT1 was validated to be targeted by miRNA-142-3p in HUVECs. Moreover, SIRT1 inhibition reversed the effects of miRNA-142-3p inhibition on senescent HUVECs exposed to H2O2. To our knowledge, this is the first study to show that miRNA-142-3p ameliorates H2O2-induced HUVECs premature senescence by targeting SIRT1 and may shed light on the role of the miR-142-3p/SIRT1 axis in stroke treatment.

A 70% Ethanol Neorhodomela munita Extract Attenuates RANKL-Induced Osteoclast Activation and H2O2-Induced Osteoblast Apoptosis In Vitro.

The rapid aging of the population worldwide presents a significant social and economic challenge, particularly due to osteoporotic fractures, primarily resulting from an imbalance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation. While conventional therapies offer benefits, they also present limitations and a range of adverse effects. This study explores the protective impact of Neorhodomela munita ethanol extract (EN) on osteoporosis by modulating critical pathways in osteoclastogenesis and apoptosis. Raw264.7 cells and Saos-2 cells were used for in vitro osteoclast and osteoblast models, respectively. By utilizing various in vitro methods to detect osteoclast differentiation/activation and osteoblast death, it was demonstrated that the EN's potential to inhibit RANKL induced osteoclast formation and activation by targeting the MAPKs-NFATc1/c-Fos pathway and reducing H2O2-induced cell death through the downregulation of apoptotic signals. This study highlights the potential benefits of EN for osteoporosis and suggests that EN is a promising natural alternative to traditional treatments.

The Potential of Bioactive Fish Collagen Oligopeptides against Hydrogen Peroxide-Induced NIH/3T3 and HUVEC Damage: The Involvement of the Mitochondria.

Extensive in vivo investigations have demonstrated the antioxidant properties of fish collagen oligopeptides (FCOPs). One of the main causes of aging and chronic non-communicable diseases is oxidative stress. Therefore, FCOPs have a broad range of applications in illness prevention and delaying aging from the standpoint of the "food is medicine" theory. However, the mechanisms that underpin the antioxidant activity of FCOPs are not completely understood. The specific objective of this essay was to investigate the antioxidant effect of FCOPs and its possible mechanism at the cellular level. Mouse embryonic fibroblasts NIH/3T3 and human vein endothelial cells (HUVECs) were exposed to 200 µM hydrogen peroxide containing different concentrations of FCOPs for 4 h and were supplemented with different concentrations of FCOPs for 24 h. Normal growth medium without FCOPs was applied for control cells. An array of assays was used to evaluate the implications of FCOPs on cellular oxidative stress status, cellular homeostasis, inflammatory levels, and mitochondrial function. We found that FCOPs exerted a protective effect by inhibiting reactive oxygen species (ROS) production, enhancing superoxide dismutase (SOD) and endothelial nitric oxide synthase (eNOS) activities and cell viability, inhibiting cell cycle arrest in the G1 phase, suppressing interleukin-1ß (IL-1ß), IL-6, matrix metalloproteinase-3 (MMP-3) and intercellular adhesion molecule-1(ICAM-1) secretion, downregulating nuclear factor-kappa B (NF-κB) activity, protecting mitochondrial membrane potential, and increasing ATP synthesis and NAD+ activities in both cells. FCOPs had a stronger antioxidant impact on NIH/3T3 than on HUVECs, simultaneously increasing glutathione peroxidase (GSH-Px) activity and decreasing malondialdehyde (MDA) content in NIH/3T3. These findings indicate that FCOPs have antioxidant effects on different tissue cells damaged by oxidative stress. FCOPs were therefore found to promote cellular homeostasis, inhibit inflammation, and protect mitochondria. Meanwhile, better health outcomes will be achieved by thoroughly investigating the effective dose and intervention time of FCOPs, as the absorption efficiency of FCOPs varies in different tissue cells.

An anthocyanin-rich extract from Zea mays L. var. ceratina alleviates neuronal cell death caused by hydrogen peroxide-induced cytotoxicity in SH-SY5Y cells.

The incidence of dementia is rising, with neuronal cell death from oxidative stress and apoptosis recognized as a significant contributor to its development. However, effective strategies to combat this condition are lacking, necessitating further investigation. This study aimed to assess the potential of an anthocyanin-rich extract from Zea mays L. var. ceratina (AZC) in alleviating neuronal cell death.Neurotoxicity was induced in SH-SY5Y cells using hydrogen peroxide (H2O2) at a concentration of 200 µM. Cells were pretreated with varying doses (31.25 and 62.5 µg/mL) of AZC. Cell viability was assessed using the MTT assay, and molecular mechanisms including reactive oxygen species (ROS) levels, antioxidant enzyme activities (catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)), malondialdehyde (MDA) levels for oxidative stress, and the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), cAMP response element-binding protein (CREB), and apoptotic factors (B-cell lymphoma 2 (Bcl-2), caspase 3) were explored.Results showed that AZC significantly improved cell viability, reduced ROS production and MDA levels, and downregulated caspase 3 expression. It enhanced CAT, SOD, and GSH-Px activities, activated ERK1/2 and CREB, and upregulated Bcl-2 expression. These findings support the neuroprotective effects of AZC, suggesting it activates ERK1/2, leading to CREB activation and subsequent upregulation of Bcl-2 expression while suppressing caspase 3. AZC may mitigate neuronal cell death by reducing ROS levels through enhanced scavenging enzyme activities.In conclusion, this study underscores the potential of AZC as a neuroprotective agent against neuronal cell death. However, further investigations including toxicity assessments, in vivo studies, and clinical trials are necessary to validate its benefits in neuroprotection.

Network pharmacology combined with experimental validation to investigate the effect of Rongjin Niantong Fang on chondrocyte apoptosis in knee osteoarthritis.

Knee osteoarthritis (KOA) is a chronic degenerative disease that affects the quality of life of middle­aged and elderly individuals, and is one of the major factors leading to disability. Rongjin Niantong Fang (RJNTF) can alleviate the clinical symptoms of patients with KOA, but the molecular mechanism underlying its beneficial effects on KOA remains unknown. Using pharmacological analysis and in vitro experiments, the active components of RJNTF were analyzed to explore their potential therapeutic targets and mechanisms in KOA. The potential targets and core signaling pathways by which RJNTF exerts its effects on KOA were obtained from databases such as Gene Expression Omnibus, Traditional Chinese Medicine Systems Pharmacology and Analysis Platform. Subsequently, chondrocyte apoptosis was modeled using hydrogen peroxide (H2O2). Cell Counting Kit­8 assay involving a poly [ADP­ribose] polymerase­1 (PARP1) inhibitor, DAPI staining, reverse transcription­quantitative PCR, Annexin V­FITC/PI staining and flow cytometry, western blotting and co­immunoprecipitation analysis were used to determine the therapeutic efficacy of RJNTF on KOA and to uncover the molecular mechanism. It was found that PARP1­knockdown lentivirus, incubation with PARP1 inhibitor PJ34, medium and high doses of RJNTF significantly reduced H2O2­induced chondrocyte apoptosis. Medium and high doses of RJNTF downregulated the expression of cleaved caspase­3, cleaved PARP1 and PAR total proteins, as well as nucleus proteins of apoptosis­inducing factor (AIF) and migration inhibitory factor (MIF), and upregulated the expression of caspase­3, PARP1 total protein, as well as the cytoplasmic expression of AIF and MIF, suggesting that RJNTF may inhibit chondrocyte apoptosis through the PARP1/AIF signaling pathway.

Efficacy evaluation of hydrogen peroxide disinfectant based zinc oxide nanoparticles against diarrhea causing Escherichia coli in ruminant animals and broiler chickens.

Different strains of Escherichia coli that exhibit genetic characteristics linked to diarrhea pose a major threat to both human and animal health. The purpose of this study was to determine the prevalence of pathogenic Escherichia coli (E. coli), the genetic linkages and routes of transmission between E. coli isolates from different animal species. The efficiency of disinfectants such as hydrogen peroxide (H2O2), Virkon®S, TH4+, nano zinc oxide (ZnO NPs), and H2O2-based zinc oxide nanoparticles (H2O2/ZnO NPs) against isolated strains of E. coli was evaluated. Using 100 fecal samples from different diarrheal species (cow n = 30, sheep n = 40, and broiler chicken n = 30) for E. coli isolation and identification using the entero-bacterial repetitive intergenic consensus (ERIC-PCR) fingerprinting technique. The E. coli properties isolated from several diarrheal species were examined for their pathogenicity in vitro. Scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared spectrum (FT-IR), X-ray diffraction (XRD), zeta potential, and particle size distribution were used for the synthesis and characterization of ZnO NPs and H2O2/ZnO NPs. The broth macro-dilution method was used to assess the effectiveness of disinfectants and disinfectant-based nanoparticles against E. coli strains. Regarding the results, the hemolytic activity and Congo red binding assays of pathogenic E. coli isolates were 55.3 and 44.7%, respectively. Eleven virulent E. coli isolates were typed into five ERIC-types (A1, A2, B1, B2, and B3) using the ERIC-PCR method. These types clustered into two main clusters (A and B) with 75% similarity. In conclusion, there was 90% similarity between the sheep samples' ERIC types A1 and A2. On the other hand, 89% of the ERIC types B1, B2, and B3 of cows and poultry samples were comparable. The H2O2/ZnO NPs composite exhibits potential antibacterial action against E. coli isolates at 0.04 mg/ml after 120 min of exposure.

A meta-analysis highlights the cross-resistance of plants to drought and salt stresses from physiological, biochemical, and growth levels.

In nature, drought and salt stresses often occur simultaneously and affect plant growth at multiple levels. However, the mechanisms underlying plant responses to drought and salt stresses and their interactions are still not fully understood. We performed a meta-analysis to compare the effects of drought, salt, and combined stresses on plant physiological, biochemical, morphological and growth traits, analyze the different responses of C3 and C4 plants, as well as halophytes and non-halophytes, and identify the interactive effects on plants. There were numerous similarities in plant responses to drought, salt, and combined stresses. C4 plants had a more effective antioxidant defense system, and could better maintain above-ground growth. Halophytes could better maintain photosynthetic rate (Pn) and relative water content (RWC), and reduce growth as an adaptation strategy. The responses of most traits (Pn, RWC, chlorophyll content, soluble sugar content, H2O2 content, plant dry weight, etc.) to combined stress were less-than-additive, indicating cross-resistance rather than cross-sensitivity of plants to drought and salt stresses. These results are important to improve our understanding of drought and salt cross-resistance mechanisms and further induce resistance or screen-resistant varieties under stress combination.

Engineered Exosomes with Growth Differentiation Factor-15 Overexpression Enhance Cardiac Repair After Myocardial Injury.

Background: Cardiac repair remains a thorny issue for survivors of acute myocardial infarction (AMI), due to the regenerative inertia of myocardial cells. Cell-free therapies, such as exosome transplantation, have become a potential strategy for myocardial injury. The aim of this study was to investigate the role of engineered exosomes in overexpressing Growth Differentiation Factor-15 (GDF-15) (GDF15-EVs) after myocardial injury, and their molecular mechanisms in cardiac repair. Methods: H9C2 cells were transfected with GDF-15 lentivirus or negative control. The exosomes secreted from H9C2 cells were collected and identified. The cellular apoptosis and autophagy of H2O2-injured H9C2 cells were assessed by Western blotting, TUNEL assay, electron microscopy, CCK-8 and caspase 3/7 assay. A rat model of AMI was constructed by ligating the left anterior descending artery. The anti-apoptotic, pro-angiogenic effects of GDF15-EVs treatment, as well as ensuing functional and histological recovery were evaluated. Then, mRNA sequencing was performed to identify the differentially expressed mRNAs after GDF15-EVs treatment. Results: GDF15-EVs inhibited apoptosis and promoted autophagy in H2O2 injured H9C2 cells. GDF15-EVs effectively decreased the infarct area and enhanced the cardiac function in rats with AMI. Moreover, GDF15-EVs hindered inflammatory cell infiltration, inhibited cell apoptosis, and promoted cardiac angiogenesis in rats with AMI. RNA sequence showed that telomerase reverse transcriptase (TERT) mRNA was upregulated in GDF15-EVs-treated H9C2 cells. AMPK signaling was activated after GDF15-EVs. Silencing TERT impaired the protective effects of GDF15-EVs on H2O2-injured H9C2 cells. Conclusion: GDF15-EVs could fulfil their protective effects against myocardial injury by upregulating the expression of TERT and activating the AMPK signaling pathway. GDF15-EVs might be exploited to design new therapies for AMI.

Advancing Photodynamic Antimicrobial Strategy: Sustainable Fabrication of Novel Lauryl Gallate-Chitosan Hydrophobic Films with Rapid Bacterial Capture and Biofilms Elimination Capabilities for Promoting Wound Healing.

Bioinspired photoactive composites, in terms of photodynamic inactivation, cost-effectiveness, and biosafety, are promising alternatives to antibiotics for combating bacterial infections while avoiding antibacterial resistance. However, the weak bacterial membrane affinity of the photoactive substrate and the lack of synergistic antibacterial effect remain crucial shortcomings for their antibacterial applications. Herein, we developed a hydrophobic film from food antioxidant lauryl gallate covalently functionalized chitosan (LG-g-CS conjugates) through a green radical-induced grafting reaction that utilizes synergistic bacteria capture, contact-killing, and photodynamic inactivation activities to achieve enhanced bactericidal and biofilm elimination capabilities. Besides, the grafting reaction mechanism between LG and CS in the ascorbic acid (AA)/H2O2 redox system was further proposed. The LG-g-CS films feature hydrophobic side chains and photoactive phenolic hydroxyl groups, facilitating dual bactericidal activities through bacteria capture and contact-killing via strong hydrophobic and electrostatic interactions with bacterial membranes as well as blue light (BL)-driven photodynamic bacterial eradication through the enhanced generation of reactive oxygen species. As a result, the LG-g-CS films efficiently capture and immobilize bacteria and exhibit excellent photodynamic antibacterial activity against model bacteria (Escherichia coli and Staphylococcus aureus) and their biofilms under BL irradiation. Moreover, LG-g-CS films could significantly promote the healing process of S. aureus-infected wounds. This research demonstrates a new strategy for designing and fabricating sustainable bactericidal and biofilm-removing materials with a high bacterial membrane affinity and photodynamic activity.

Methionine biosynthetic genes and methionine sulfoxide reductase A are required for Rhizoctonia solani AG1-IA to cause sheath blight disease in rice.

Rhizoctonia solani is a polyphagous necrotrophic fungal pathogen that causes sheath blight disease in rice. It deploys effector molecules as well as carbohydrate-active enzymes and enhances the production of reactive oxygen species for killing host tissues. Understanding R. solani ability to sustain growth under an oxidative-stress-enriched environment is important for developing disease control strategies. Here, we demonstrate that R. solani upregulates methionine biosynthetic genes, including Rs_MET13 during infection in rice, and double-stranded RNA-mediated silencing of these genes impairs the pathogen's ability to cause disease. Exogenous treatment with methionine restores the disease-causing ability of Rs_MET13-silenced R. solani and facilitates its growth on 10 mM H2O2-containing minimal-media. Notably, the Rs_MsrA gene that encodes methionine sulfoxide reductase A, an antioxidant enzyme involved in the repair of oxidative damage of methionine, is upregulated upon H2O2 treatment and also during infection in rice. Rs_MsrA-silenced R. solani is unable to cause disease, suggesting that it is important for the repair of oxidative damage in methionine during host colonization. We propose that spray-induced gene silencing of Rs_MsrA and designing of antagonistic molecules that block MsrA activity can be exploited as a drug target for effective control of sheath blight disease in rice.

Predicting the cryotolerance of boar sperm through antioxidant stress.

High sperm cryotolerance is crucial to the successful cryopreservation of boar sperm. Evaluating the cryotolerance of boar sperm by using a rapid and convenient technique can enhance the commercial viability of these sperm. This study investigated the correlation between sperm parameters for three sample subsets-fresh sperm, sperm with H2O2-induced oxidative damage (hereinafter referred to as H2O2-induced sperm), and frozen-thawed sperm-to identify the potential of these correlations to predict cryotolerance. A total of 64 sperm samples were obtained from 64 Duroc boars. The sperm parameters of the three subsets, where the frozen-thawed sperm were analysed at 30 or 180 min after thawing, were determined, and the coefficients of correlation between these parameters were calculated. The results indicated that H2O2-induced oxidative stress resulted in decreases in various sperm parameters-including total motility (TM), viability (VIA), mitochondrial membrane potential (MMP), and live sperm with MMP (LMP)-but increased their coefficients of variation. Receiver operating characteristic (ROC) curve analysis revealed that the kinematic parameters of the H2O2-induced sperm effectively predicted those of the frozen-thawed boar sperm at 30 min after thawing; the corresponding area under the ROC curve (AUC) was 0.8667 for TM and 0.8733 for progressive motility in the H2O2-induced sperm. For measurement at 180 min after thawing, the sperm membrane and mitochondrial parameters of the H2O2-induced sperm effectively predicted the LMP of the frozen-thawed boar sperm; the corresponding AUC was 0.8489 for VIA, 0.8289 for MMP, and 0.8444 for LMP. To our knowledge, this is the first study to directly establish a strong correlation between post-thaw boar sperm quality and H2O2-induced oxidative stress before freezing. Our proposed technique can serve as a valuable reference for the development of practical applications aimed at enhancing techniques for cryopreserving boar sperm.

Deinococcus wulumuqiensis R12 synthesized silver nanoparticles with peroxidase-like activity for synergistic antibacterial application.

The use of a combination of several antibacterial agents for therapy holds great promise in reducing the dosage and side effects of these agents, improving their efficiency, and inducing potential synergistic therapeutic effects. Herein, this study provides an innovative antibacterial treatment strategy by synergistically combining R12-AgNPs with H2O2 therapy. R12-AgNPs were simply produced with the supernatant of an ionizing radiation-tolerant bacterium Deinococcus wulumuqiensis R12 by one-step under room temperature. In comparison with chemically synthesized AgNPs, the biosynthesized AgNPs presented fascinating antibacterial activity and peroxidase-like properties, which endowed it with the capability to catalyze the decomposition of H2O2 to generate hydroxyl radical. After the combination of R12-AgNPs and H2O2, an excellent synergistic bacteriostatic activity was observed for both Escherichia coli and Staphylococcus aureus, especially at low concentrations. In addition, in vitro cytotoxicity tests showed R12-AgNPs had good biocompatibility. Thus, this work presents a novel antibacterial agent that exhibits favorable synergistic antibacterial activity and low toxicity, without the use of antibiotics or a complicated synthesis process.