Reactive Oxygen Species Damage Research Articles

Preclinical evaluation of combined therapy with amiodarone and low-dose benznidazole in a mouse model of chronic Trypanosoma cruzi infection

Chagasic chronic cardiomyopathy (CCC) is the primary clinical manifestation of Chagas disease (CD), caused by Trypanosoma cruzi. Current therapeutic options for CD are limited to benznidazole (Bz) and nifurtimox. Amiodarone (AMD) has emerged as most effective drug for treating the arrhythmic form of CCC. To address the effects of Bz and AMD we used a preclinical model of CCC. Female C57BL/6 mice were infected with T. cruzi and subjected to oral treatment for 30 consecutive days, either as monotherapy or in combination. AMD in monotherapy decreased the prolonged QTc interval, the incidence of atrioventricular conduction disorders and cardiac hypertrophy. However, AMD monotherapy did not impact parasitemia, parasite load, TNF concentration and production of reactive oxygen species (ROS) in cardiac tissue. Alike Bz therapy, the combination of Bz and AMD (Bz/AMD), improved cardiac electric abnormalities detected T. cruzi-infected mice such as decrease in heart rates, enlargement of PR and QTc intervals and increased incidence of atrioventricular block and sinus arrhythmia. Further, Bz/AMD therapy ameliorated the ventricular function and reduced parasite burden in the cardiac tissue and parasitemia to a degree comparable to Bz monotherapy. Importantly, Bz/AMD treatment efficiently reduced TNF concentration in the cardiac tissue and plasma and had beneficial effects on immunological abnormalities. Moreover, in the cardiac tissue Bz/AMD therapy reduced fibronectin and collagen deposition, mitochondrial damage and production of ROS, and improved sarcomeric and gap junction integrity. Our study underlines the potential of the Bz/AMD therapy, as we have shown that combination increased efficacy in the treatment of CCC.

Lactate facilitated mitochondrial fission-derived ROS to promote pulmonary fibrosis via ERK/DRP-1 signaling

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic interstitial lung diseases, which mainly existed in middle-aged and elderly people. The accumulation of reactive oxygen species (ROS) is a common characteristic of IPF. Previous research also shown that lactate levels can be abnormally elevated in IPF patients. Emerging evidence suggested a relationship between lactate and ROS in IPF which needs further elucidation. In this article, we utilized a mouse model of BLM-induced pulmonary fibrosis to detect alterations in ROS levels and other indicators associated with fibrosis. Lactate could induce mitochondrial fragmentation by modulating expression and activity of DRP1 and ERK. Moreover, Increased ROS promoted P65 translocation into nucleus, leading to expression of lung fibrotic markers. Finally, Ulixertinib, Mdivi-1 and Mito-TEMPO, which were inhibitor activity of ERK, DRP1 and mtROS, respectively, could effectively prevented mitochondrial damage and production of ROS and eventually alleviate pulmonary fibrosis. Taken together, these findings suggested that lactate could promote lung fibrosis by increasing mitochondrial fission-derived ROS via ERK/DRP1 signaling, which may provide novel therapeutic solutions for IPF.

Protective effect of luteolin against oxidative stress‑mediated cell injury via enhancing antioxidant systems.

Physiological stress such as excessive reactive oxygen species (ROS) production may contribute normal fibroblasts activation into cancer‑associated fibroblasts, which serve a crucial role in certain types of cancer such as pancreatic, breast, liver and lung cancer. The present study aimed to examine the cytoprotective effects of luteolin (3',4',5,7‑tetrahydroxyflavone) against hydrogen peroxide (H2O2)‑generated oxidative stress in lung fibroblasts. To examine the effects of luteolin against H2O2‑induced damages, cell viability, sub‑G1 cell population, nuclear staining with Hoechst 33342, lipid peroxidation and comet assays were performed. To evaluate the effects of luteolin on the protein expression level of apoptosis, western blot assay was performed. To assess the antioxidant effects of luteolin, detection of ROS using H2DCFDA staining, O2‑ and ·OH using electron spin resonance spectrometer and antioxidant enzyme activity was performed. In a cell‑free chemical system, luteolin scavenges superoxide anion and hydroxyl radical generated by xanthine/xanthine oxidase and the Fenton reaction (FeSO4/H2O2). Furthermore, Chinese hamster lung fibroblasts (V79‑4) treated with H2O2 showed a significant increase in cellular ROS. Intracellular ROS levels and damage to cellular components such as lipids and DNA in H2O2‑treated cells were significantly decreased by luteolin pretreatment. Luteolin increased cell viability, which was impaired following H2O2 treatment and prevented H2O2‑mediated apoptosis. Luteolin suppressed active caspase‑9 and caspase‑3 levels while increasing Bcl‑2 expression and decreasing Bax protein levels. Additionally, luteolin restored levels of glutathione that was reduced in response to H2O2. Moreover, luteolin enhanced the activity and protein expressions of superoxide dismutase, catalase, glutathione peroxidase, and heme oxygenase‑1. Overall, these results indicated that luteolin inhibits H2O2‑mediated cellular damage by upregulating antioxidant enzymes.

MOF-based nanoparticles for tumor-targeted protein degradation and photodynamic therapy induce enhanced anti-tumor immunity

Combining proteolysis targeting chimeras (PROTACs) with photodynamic therapy (PDT) is a promising strategy for cancer treatment. However, the therapeutic efficacy is impaired due to the poor water solubility or the unsatisfactory tumor distribution of drugs. Herein, we developed a Hyaluronan (HA) coating MOF-based nanoplatform (ZMCH) to achieve the combined therapy of PROTACs and PDT with tumor-specific delivery and local drug release. The PROTACs molecules and photosensitizers could be easily wrapped into the nanoparticles via the self-assembly of zinc ions and 2-methylimidazole, which is a universal encapsulation approach for the conventional PROTACs or photosensitizers. As a proof-of-concept, we demonstrated that the designed ZMCH nanoreactor effectively suppresses tumor growth in the 4T1-tumor-bearing mice model, resulting from the synergistic effect of MZ1-mediated protein degradation and the Ce6-mediated reactive oxygen species (ROS) damage. Importantly, the ZMCH-induced therapy exhibited the enhanced antitumor T-cell immunity by regulating immunosuppressive tumor microenvironment, thereby effectively inhibiting tumor metastasis in the lungs. This work thus provides a novel approach and insights for the combination therapy of protein degradation and PDT in clinical cancer treatment.

ROS-Responsive Methionine-Containing Amphiphilic Peptides Impart Enzyme-Triggered Phase Transition and Antioxidant Cell Protection.

Reactive oxygen species (ROS) are produced by cellular activities, such as metabolism and immune response, and play important roles in cell signaling and homeostasis. However, overproduced ROS causes irreversible damage to nucleic acids and membrane lipids, supporting genetic mutations and enhancing the effects of aging. Cells defend themselves against ROS using antioxidant systems based on redox-active sulfur and transition metals. Inspired by such biological redox-responsive systems, we developed methionine-containing self-assembling peptides. The Met-containing peptides formed hydrogels that underwent a gel-to-sol phase transition upon oxidation by H2O2, and the sensitivity of the peptides to the oxidant increased as the number of Met residues increased. The peptide containing three Met residues, the largest number of Met residues in our series of designed peptides, showed the highest sensitivity to oxidation and detoxification to protect cells from ROS damage. In addition, this peptide underwent a phase transition in response to H2O2 produced by an oxidizing enzyme. This study demonstrates the design of a supramolecular biomaterial that is responsive to enzymatically generated ROS and can protect cells against oxidative stress.

The distribution and sequestration of cercosporin by Cercospora cf. flagellaris.

Plant pathogenic fungi produce toxins as virulence factors in many plant diseases. In Cercospora leaf blight (CLB) of soybean caused by Cercospora cf. flagellaris, symptoms are a consequence of the production of a perylenequinone toxin, cercosporin, which is light-activated to produce damaging reactive oxygen species (ROS). Cercosporin is universally toxic to cells, except to the cells of the producer. The current model of self-resistance to cercosporin is largely attributed to the maintenance of cercosporin in a chemically-reduced state inside hyphae, unassociated with cellular organelles. However, in another perylenequinone-producing fungus, Phaeosphaeria sp., the toxin was specifically sequestered inside lipid droplets (LDs) to prevent ROS production. This study hypothesized that LD-based sequestration of cercosporin occurred in C. cf. flagellaris and that lipid-inhibiting fungicides could inhibit toxin production. Confocal microscopy using light-cultured C. cf. flagellaris indicated that 3-day old hyphae contained two forms of cercosporin distributed in two types of hyphae. Reduced cercosporin was uniformly distributed in the cytoplasm of thick, primary hyphae, and contrary to previous studies, active cercosporin was observed specifically in LDs of thin, secondary hyphae. The production of hyphae of two different thicknesses, a characteristic of hemibiotrophic plant pathogens, has not been documented in C. cf. flagellaris. No correlation was observed between cercosporin production and total lipid extracted, and two lipid-inhibiting fungicides had little effect on fungal growth in growth-inhibition assays. The study lays a foundation to explore the importance of pathogen lifestyle, toxin production, and LD content in pathogenicity and symptomology of Cercospora.

Assessment of the toxicity of different antiretroviral drugs and their combinations on Sertoli and Leydig cells

The human immunodeficiency virus continues to pose a significant global public health challenge, affecting millions of individuals. The current treatment strategy has incorporated the utilization of combinations of antiretroviral drugs. The administration of these drugs is associated with many deleterious consequences on several physiological systems, notably the reproductive system. This study aimed to assess the toxic effects of abacavir sulfate, ritonavir, nevirapine, and zidovudine, as well as their combinations, on TM3 Leydig and TM4 Sertoli cells. The cell viability was gauged using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) and neutral red uptake (NRU) assays. Reactive oxygen species (ROS) production was assessed via the 2’,7’-dichlorofluorescein diacetate (DCFDA) test, and DNA damage was determined using the comet assay. Results indicated cytotoxic effects at low drug concentrations, both individually and combined. The administration of drugs, individually and in combination, resulted in the production of ROS and caused damage to the DNA at the tested concentrations. In conclusion, the results of this study suggest that the administration of antiretroviral drugs can lead to testicular toxicity by promoting the generation of ROS and DNA damage. Furthermore, it should be noted that the toxicity of antiretroviral drug combinations was shown to be higher compared to that of individual drugs.

Bioenergetics of iron snow fueling life on Europa

The main sources of redox gradients supporting high-productivity life in the Europan and other icy ocean world oceans were proposed to be photolytically derived oxidants, such as reactive oxygen species (ROS) from the icy shell, and reductants (Fe(II), S(-II), CH4, H2) from bottom waters reacting with a (ultra)mafic seafloor. Important roadblocks to maintaining life, however, are that the degree of ocean mixing to combine redox species is unknown, and ROS damage biomolecules. Here, we envisage a unique solution using an acid mine drainage (AMD)-filled pit lakes analog system for the Europan ocean, which previous models predicted to be acidic. We hypothesize that surface-generated ROS oxidize dissolved Fe(II) resulting in Fe(III) (hydr)oxide precipitates, that settle to the seafloor as "iron snow." The iron snow provides a respiratory substrate for anaerobic microorganisms ("breathing iron"), and limits harmful ROS exposure since they are now neutralized at the ice-water interface. Based on this scenario, we calculated Gibbs energies and maximal biomass productivities of various anaerobic metabolisms for a range of pH, temperatures, and H2 fluxes. Productivity by iron reducers was greater for most environmental conditions considered, whereas sulfate reducers and methanogens were more favored at high pH. Participation of Fe in the metabolic redox processes is largely neglected in most models of Europan biogeochemistry. Our model overcomes important conceptual roadblocks to life in icy ocean worlds and broadens the potential metabolic diversity, thus increasing total primary productivity, the diversity and volume of habitable environmental niches and, ultimately, the probability of biosignature detection.

Arbuscular mycorrhizal fungi enhanced resistance to low-temperature weak-light stress in snapdragon (Antirrhinum majus L.) through physiological and transcriptomic responses.

Low temperature (LT) and weak light (WL) seriously affects the yield and quality of snapdragon in winter greenhouse. Arbuscular mycorrhizal fungi (AMF) exert positive role in regulating growth and enhancing abiotic stress tolerance in plants. Nevertheless, the molecular mechanisms by AMF improve the LT combined with WL (LTWL) tolerance in snapdragon remain mostly unknown. We compared the differences in root configuration, osmoregulatory substances, enzymatic and non-enzymatic antioxidant enzyme defense systems and transcriptome between AMF-inoculated and control groups under LT, WL, low light, and LTWL conditions. Our analysis showed that inoculation with AMF effectively alleviated the inhibition caused by LTWL stress on snapdragon root development, and significantly enhanced the contents of soluble sugars, soluble proteins, proline, thereby maintaining the osmotic adjustment of snapdragon. In addition, AMF alleviated reactive oxygen species damage by elevating the contents of AsA, and GSH, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and glutathione reductase (GR). RNA-seq analysis revealed that AMF regulated the expression of genes related to photosynthesis (photosystem I related proteins, photosystem II related proteins, chlorophyll a/b binding protein), active oxygen metabolism (POD, Fe-SOD, and iron/ascorbate family oxidoreductase), plant hormone synthesis (ARF5 and ARF16) and stress-related transcription factors gene (bHLH112, WRKY72, MYB86, WRKY53, WRKY6, and WRKY26) under LTWL stress. We concluded that mycorrhizal snapdragon promotes root development and LTWL tolerance by accumulation of osmoregulatory substances, activation of enzymatic and non-enzymatic antioxidant defense systems, and induction expression of transcription factor genes and auxin synthesis related genes. This study provides a theoretical basis for AMF in promoting the production of greenhouse plants in winter.

Physiological and biochemical response analysis of Styrax tonkinensis seedlings to waterlogging stress

Climate change is increasing flooding in provinces of the south of the Yangtze River, posing challenges for promoting Styrax tonkinensis seedlings in these areas. To understand the physiological reasons for this species' intolerance to waterlogging, we observed biochemical parameters in one-year-old S. tonkinensis seedlings during two seasons. For 4 and 12 days in summer and winter experiments, respectively, we subjected seedlings to a pot-in-pot waterlogging treatment. Control groups were established at 0 h and 0 days. We examined indicators related to root vigor, reactive oxygen species (ROS), antioxidant enzymes, fermentative pathways, and more. The results displayed that decreased abscisic acid accumulation in roots inhibited water transport. Increased dehydrogenase and lactate dehydrogenase activity in roots promoted alcohol and lactate fermentation, causing toxic damage and reduced root vigor, impeding water absorption. In leaves, high ROS levels led to lipid peroxidation, exacerbating water loss from continuous transpiration. The high relative electric conductivity and low leaf relative water content indicated water loss, causing leaf wilting and shriveling. Conversely, winter seedlings, devoid of leaves, significantly reduced transpiration, and dormancy delayed root fermentation. With less ROS damage in roots, winter seedlings exhibited greater waterlogging tolerance. In summary, excessive water loss from leaves and inhibited vertical water transport contributed to low summer survival rates, while winter leafless dormancy and reduced ROS damage enhanced tolerance. Our findings provide insights for enhancing waterlogging resistance in S. tonkinensis amidst climate change challenges.

Identification and characterization of the critical genes encoding Cd-induced enhancement of SOD isozymes activities in Zhe-Maidong (Ophiopogon japonicus).

Superoxide dismutase (SOD) protects plants from abiotic stress-induced reactive oxygen species (ROS) damage. Here, the effects of cadmium (Cd) exposure on ROS accumulation and SOD isozymes, as well as the identification of significant SOD isozyme genes, were investigated under different Cd stress treatments to Zhe-Maidong (Ophiopogon japonicus). The exposure to Cd stress resulted in a notable elevation in the SOD activity in roots. Cu/ZnSODa and Cu/ZnSODb were the most critical SOD isozymes in response to Cd stress, as indicated by the detection results for SOD isozymes. A total of 22 OjSOD genes were identified and classified into three subgroups, including 10 OjCu/ZnSODs, 6 OjMnSODs, and 6 OjFeSODs, based on the analysis of conserved motif and phylogenetic tree. Cu/ZnSOD-15, Cu/ZnSOD-18, Cu/ZnSOD-20, and Cu/ZnSOD-22 were the main genes that control the increase in SOD activity under Cd stress, as revealed via quantitative PCR and transcriptome analysis. Additionally, under various heavy metal stress (Cu2+, Fe2+, Zn2+, Mn2+), Cu/ZnSOD-15, Cu/ZnSOD-18, and Cu/ZnSOD-22 gene expression were significantly upregulated, indicating that these three genes play a critical part in resisting heavy metal stress. The molecular docking experiments performed on the interaction between oxygen ion (O2•-) and OjSOD protein have revealed that the critical amino acid residues involved in the binding of Cu/ZnSOD-22 to the substrate were Pro135, Ile136, Ile140, and Arg144. Our findings provide a solid foundation for additional functional investigations on the OjSOD genes, as well as suggestions for improving genetic breeding and agricultural management strategies to increase Cd resistance in O. japonicus.

Abstract 711: HDAC3 sustains resistance to hypofractionated radiotherapy in fusion positve rhabdomyosarcoma cells

Abstract Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood. The fusion-positive (FP)-RMS variant expressing chimeric oncoproteins such as PAX3-FOXO1 and PAX7-FOXO1 shows a dismal prognosis with 5-year survival of less than 30% compared to non-metastatic fusion-negative (FN)-RMS variant. In the last years, a lot of interest has focused on new targets identification to improve the radiotherapy (RT) efficacy. HDAC inhibitors (HDACi) radio-sensitize different cancer cell types including RMS. Recently, we reported that MS-275, a Class I and IV HDACi, in combination with RT affected cell survival, reduced colony formation ability, increased DNA damage repair inhibition and reactive oxygen species formation in FP-RMS cells. However, despite promising preclinical studies, HDAC inhibitors (HDACi) achieved only modest success in human clinical trials for solid tumors, frequently showing several toxicities, probably because of the limited specificity of many HDACi. Thus, a major effort is being directed toward identification of HDACi which are selective for HDAC isoforms often uniquely implicated in the radioresistance of specific cancers. In order to identify the class I HDAC responsible of radioresistance in RMS we knocked-down HDAC1, HDAC2, HDAC3, and HDAC8 expression in combination with RT. Interestingly, we observed an increased radiosensitivity only in HDAC3-depleted FP-RMS cells. Thus, we focused on HDAC3 to understand the mechanisms by which it promotes radioresistance in RMS. We observed that HDAC3 is overexpressed in RMS patients and cell lines compared to the normal counterpart. Furthermore, RMS cells are strongly dependent by HDAC3 expression while slight dependency has been observed with other class I HDACs in DepMap portal. We demonstrated that HDAC3 depletion by CRISPR in combination with RT in FP-RMS cells increases apoptosis, reduces colony formation ability, cancer stem cells population and anchorage independent growth and reduces cell growth in vivo and in vitro. Accordingly, HDAC3 depleted cells in combination with RT reduces levels and activation of key player of FP-RMS biology such as MYCN, ERK and AKT. Moreover, HDAC3 KD increases radiotherapy-induced DNA double strand break and impairs DNA repair mechanisms reducing levels and activation of both homologous recombination (HR) and non-homologous end joining (NHEJ) factors such as ATM, RAD51 and DNA-PKcs. Thus, we developed a new potent and highly specific HDAC3 inhibitor (HDAC3i). The new HDAC3i is highly specific in targeting FP-RMS cell growth in vitro while no effects have been observed in normal cells such as myoblasts and lung fibroblast. Moreover, the drug treatment in combination with radiotherapy phenotypically and molecularly recapitulated what observed in HDAC3 depleted cells.The study has been founded by Italian Association for Cancer Research (AIRC) to FM. Citation Format: Matteo Cassandri, Antonella Porrazzo, Silvia Pomella, Simona Camero, Francesca A. Aiello, Lucrezia D'Archivio, Clemens Zwergel, Beatrice Noce, Miriam Tomaciello, Francesca Vulcano, Luisa Milazzo, Francesca Pedini, Michele Signore, Alessandro Fanzani, Cinzia Marchese, Giuseppe Minniti, Sergio Valente, Antonello Mai, Francesca Megiorni, Rossella Rota, Francesco Marampon. HDAC3 sustains resistance to hypofractionated radiotherapy in fusion positve rhabdomyosarcoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 711.

Integrated physiological, biochemical and transcriptomic analyses reveal the mechanism of salt tolerance induced by a halotolerant Serratia sp. NTN6 in maize

Salt stress is a serious environmental challenge that hinders crop growth and yield. Plant growth-promoting rhizobacteria (PGPR) can successfully and environmentally friendly boost plant development in saline soils. In this study, a halotolerant Serratia sp. NTN6 was isolated from the rhizosphere soil of halophyte Puccinellia tenuiflora and its plant growth-promoting properties were determined. NTN6 inoculation significantly promoted seed germination and seedling growth in maize under salt stress. Shoot height, stem thickness, root fresh weight, shoot fresh weight, root dry weight, and shoot dry weight of salt-stressed seedlings increased by 36.3%, 32.5%, 146.4%, 193.6%, 25.0%, and 109.6%, respectively, after inoculation with NTN6. NTN6-mediated maize salt tolerance was revealed via transcriptomic, physiological, and biochemical analyses. Under salt stress, NTN6 regulated the transcript levels of genes related to chlorophyll synthesis, photosynthesis apparatus, and carbon assimilation pathways, and thus increasing chlorophyll content, Fv/Fm, and net photosynthetic rate; NTN6 reduced the content of O2•–, H2O2, and MDA by regulating the transcripts and activities of antioxidant enzymes; NTN6 affected the transcriptional response of genes involved in ABA synthesis and signaling to salt stress and reduced ABA level. Finally, NTN6 boosted photosynthetic capacity in salt-stressed maize by modulating photochemical activity, C4 pathway and Calvin cycle as well as mitigating reactive oxygen species damage to the photosystem reaction center. This study first investigated the mechanism of Serratia sp.-induced salt tolerance in maize and these findings demonstrate the valuable contribution of halotolerant PGPR strain from halophytes in improving salinity tolerance in non-halophytic crops.

Abstract B016: Repurposing nelfinavir for re-sensitizing platinum-resistant high grade serous ovarian cancer cells

Abstract B016: Repurposing nelfinavir for re-sensitizing platinum-resistant high grade serous ovarian cancer cells

Antioxidants for Early Treatment of Type 2 Diabetes in Rodents and Humans: Lost in Translation?

Reactive oxygen species (ROS) are formed by virtually all tissues. In normal concentrations they facilitate many physiologic activities, but in excess they cause oxidative stress and tissue damage. Local antioxidant enzyme synthesis in cells is regulated by the cytoplasmic KEAP-1/ Nrf2 complex, which is stimulated by ROS, to release Nrf2 for entry into the nucleus where it upregulates antioxidant gene expression. Major antioxidant enzymes include glutathione peroxidase (GPx), catalase (CAT), superoxide dismutases (SOD), hemoxygenases (HO), and peroxiredoxins (Prdx). Notably, the pancreatic islet beta cell does not express GPx or CAT, which puts it at greater risk for ROS damage caused by postprandial hyperglycemia. Experimentally, overexpression of GPx in beta cell lines and isolated islets as well as in vivo studies using genetic models of type 2 diabetes, have demonstrated enhanced protection against hyperglycemia and oxidative stress. Oral treatment of diabetic rodents with Ebselen, a GPx mimetic that is approved for human clinical usereproduced these findings. Prdxs detoxify hydrogen peroxide and reduce lipid peroxides. This suggests that pharmacologic development of more potent, beta cell specific antioxidants could be valuable as a treatment for oxidative stress due to post-prandial hyperglycemia in early type 2 diabetes in humans.

Biosynthesis of high antibacterial silver chloride nanoparticles against Ralstonia solanacearum using spent mushroom substrate extract

Abstract In this study, a green and highly efficient method was proposed to synthesize nano-silver chloride (nano-AgCl) by using spent mushroom substrate (SMS) extract as a cheap reactant. Nanoparticles were characterized by a series of techniques like X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), which showed the formation of near-spherical silver chloride nanoparticles with an average size of about 8.30 nm. Notably, the synthesized nano-silver chloride has a more prominent antibacterial effect against Ralstonia solanacearum (EC50=5.18 mg/L) than non-nano-sized silver chloride particles, nano-silver chloride synthesized by chemical method, and commercial pesticides. In-depth, the study of mechanism revealed that nano-silver chloride could cause cell membrane disruption, DNA damage and intracellular generation of reactive oxygen species (•OH, •O2- and 1O2) leading to peroxidation damage in Ralstonia solanacearum (R. solanacearum). And the reaction between nano-silver chloride and bacteria could be driven by intermolecular forces instead of electrostatic interactions. Our study provides a new approach to synthesizing nano-silver chloride as a highly efficient antibacterial agent and broadens the utilization of agricultural waste spent mushroom substrate.

Assessment of the impact of direct in vitro PFAS treatment on mouse spermatozoa.

Poly- and per-fluoroalkyl substances (PFAS) are synthetic environmentally persistent chemicals. Despite the phaseout of specific PFAS, their inherent stability has resulted in ubiquitous and enduring environmental contamination. PFAS bioaccumulation has been reported globally with omnipresence in most populations wherein they have been associated with a range of negative health effects, including strong associations with increased instances of testicular cancer and reductions in overall semen quality. To elucidate the biological basis of such effects, we employed an acute in vitro exposure model in which the spermatozoa of adult male mice were exposed to a cocktail of PFAS chemicals at environmentally relevant concentrations. We hypothesized that direct PFAS treatment of spermatozoa would induce reactive oxygen species generation and compromise the functional profile and DNA integrity of exposed cells. Despite this, post-exposure functional testing revealed that short-term PFAS exposure (3 h) did not elicit a cytotoxic effect, nor did it overtly influence the functional profile, capacitation rate, or the in vitro fertilization ability of spermatozoa. PFAS treatment of spermatozoa did, however, result in a significant delay in the developmental progression of the day 4 pre-implantation embryos produced in vitro. This developmental delay could not be attributed to a loss of sperm DNA integrity, DNA damage, or elevated levels of intracellular reactive oxygen species. When considered together, the results presented here raise the intriguing prospect that spermatozoa exposed to a short-term PFAS exposure period potentially harbor an alternate stress signal that is delivered to the embryo upon fertilization. PFAS are synthetic chemicals widely used in non-stick cookware, food packaging, and firefighting foam. Such extensive use has led to concerning levels of environmental contamination and reports of associations with a spectrum of negative health outcomes, including testicular cancer and reduced semen quality. To investigate the effects of PFAS on male reproduction, we incubated mouse sperm in a cocktail of nine PFAS at environmentally relevant concentrations before checking for a range of functional outcomes. This treatment strategy was not toxic to the sperm; it did not kill them or reduce their motility, nor did it affect their fertilization capacity. However, we did observe developmental delays among pre-implantation embryos created using PFAS-treated sperm. Such findings raise the intriguing prospect that PFAS-exposed sperm harbor a form of stress signal that they deliver to the embryo upon fertilization.

Mesoporous Ternary Nanozymes with Anti‐Senescence and Anti‐Inflammation Activities for Atherosclerosis Management

AbstractNumerous anti‐inflammatory agents and corresponding therapeutic strategies have been explored for treating inflammation‐related atherosclerosis, which has struggled with compromised antiatherosclerotic efficacy due to the complex pathogenesis. The senescent endothelial cells participate fundamentally at all stages in atherosclerosis, providing the basis for developing senotherapies to blunt the deleterious effects of senescent cells. In this work, a mesoporous palladium‐boron‐phosphorus ternary nanozyme with intrinsic superoxide dismutase/catalase‐mimicking properties is rationally engineered to co‐load H2 (an anti‐inflammatory agent) within nanozyme's crystal lattice and 4,4′‐dimethoxychalcone (DIM, an anti‐senescence agent) within mesopores, which elicits strong anti‐inflammatory effect in pro‐inflammatory macrophages by elimination of reactive oxygen species (ROS), H2 anti‐inflammation and promotion of cholesterol efflux, while simultaneously exerts anti‐senescence capacity in endothelial cells by protection of DNA from ROS damage and degradation of the cellular senescent components via autophagy activation. Both in vitro and in vivo experimental results verify the synergy between nanozyme‐based anti‐inflammatory therapy and autophagy activation, demonstrating that such a precise regulation of vascular senescence is applicable to augment antiatherosclerotic efficiency, which provides the nanomedicine‐enabled and senotherapy‐based paradigm for atherosclerosis management.

Enhanced photodynamic therapy efficacy of Ni-doped/oxygen vacancy double-defect Ni-ZnO@C photosensitizer in bacteria-infected wounds based on ROS damage and ATP synthesis inhibition

The use of zinc oxide (ZnO) photosensitizers (PSs)-mediated photodynamic therapy (PDT) against bacterial wound infections is greatly restricted by diminished photocatalytic efficiency caused by the rapid recombination of photogenerated electrons and holes. In this work, ZnO PSs with a Ni-doped/oxygen vacancy and a protective carbon shell were successfully synthesized by calcinating a Ni-doping zeolitic imidazolate framework-8 precursor. The double-defect structure and the carbon-based substrates significantly promoted the efficiency of photogenerated electron–hole pair separation, meanwhile, the 3 % Ni doping endows it with great photocatalytic performance as elucidated by photodegradation assays of methylene blue (MB) and density functional theory (DFT) calculations, reinforcing the generation of reactive oxygen species (ROS) by ZnO and showing obvious advantages in antibacterial properties. As the enhanced photogenerated electron transfer and the ROS damage underwent localized accumulation, the PSs disturbed the bacterial membrane integrity and caused bacterial ATP synthesis inhibition, further leading to bacterial lysis and promoting bacterial deaths. Additionally, the PSs showed outstanding efficacy in eradicating bacterial biofilms. Simultaneously, the significantly enhanced PDT antibacterial performance of the PSs in vivo could initiate wound tissue repair and trigger anti-inflammatory reactions by significantly regulating the expression levels of regeneration- and inflammation-related genes or proteins. Furthermore, the PSs consistently exhibited favorable compatibility both in vitro and in vivo. In summary, this study offers evidence of the remarkably efficient and biologically safe performance of Ni-ZnO@C PSs, with antibacterial properties advancing wound healing, both in controlled laboratory environments and living organisms, further underscoring their substantial potential for biomedical applications.

An Overview of Reactive Oxygen Species Damage Occurring during In Vitro Bovine Oocyte and Embryo Development and the Efficacy of Antioxidant Use to Limit These Adverse Effects.

The in vitro production (IVP) of bovine embryos has gained popularity worldwide and in recent years and its use for producing embryos from genetically elite heifers and cows has surpassed the use of conventional superovulation-based embryo production schemes. There are, however, several issues with the IVP of embryos that remain unresolved. One limitation of special concern is the low efficiency of the IVP of embryos. Exposure to reactive oxygen species (ROS) is one reason why the production of embryos with IVP is diminished. These highly reactive molecules are generated in small amounts through normal cellular metabolism, but their abundances increase in embryo culture because of oocyte and embryo exposure to temperature fluctuations, light exposure, pH changes, atmospheric oxygen tension, suboptimal culture media formulations, and cryopreservation. When uncontrolled, ROS produce detrimental effects on the structure and function of genomic and mitochondrial DNA, alter DNA methylation, increase lipid membrane damage, and modify protein activity. Several intrinsic enzymatic pathways control ROS abundance and damage, and antioxidants react with and reduce the reactive potential of ROS. This review will focus on exploring the efficiency of supplementing several of these antioxidant molecules on oocyte maturation, sperm viability, fertilization, and embryo culture.