Antioxidant Features of Humic Products by ABTS Assay.

Oxidative stress plays a pivotal role in driving immunosenescence by disrupting cellular homeostasis and impairing immune function. Humic substances exhibit scavenging activity against reactive oxygen species (ROS), inhibit ROS generation via metal chelation, and modulate endogenous antioxidant enzyme activity. Additionally, humic substances display anti-inflammatory effects, further supporting cellular redox balance. Given their antioxidant activity, humic substances hold promise as natural compounds for mitigating oxidative stress-associated immunosenescence. Here we describe the evaluation of antioxidant capacities of humic products by ABTS spectrophotometric assay.

Ultrasmall iridium-encapsulated porphyrin metal-organic frameworks for enhanced photodynamic/catalytic therapy by producing reactive oxygen species storm.

Transition metal-coordinated porphyrin metal-organic frameworks (MOFs) were perspective in photodynamic therapy (PDT) and catalytic therapy. However, the tumor hypoxia and the insufficient endogenous hydrogen peroxide (H2O2) seriously limited their efficacies. Herein, by encapsulating ultrasmall iridium (Ir) and modifying glucose oxidase (GOx), an iron-coordinated porphyrin MOF (Fe-MOF) nanoplatform (Fe-MOF@Ir/GOx) was designed to strengthen PDT/catalytic therapy by producing reactive oxygen species (ROS) storm. In this nanoplatform, Fe-MOF showed glutathione (GSH)-responsive degradation, by which porphyrin, GOx and ultrasmall Ir were released. Moreover, ultrasmall Ir possessed dual-activities of catalase (CAT)-like and peroxidase (POD)-like, which provided sufficient oxygen (O2) to enhance PDT efficacy, and hydroxyl radical (·OH) production was also improved by combining Fenton reaction of Fe2+. Further, GOx catalyzed endogenous glucose produced H2O2, also reduced pH value, which accelerated Fenton reaction and resulted in generation of ROS storm. Therefore, the developed Fe-MOF@Ir/GOx nanoplatform demonstrated enhanced PDT/catalytic therapy by producing ROS storm, and also provided a promising strategy to promote degradation/metabolism of inorganic nanoplatforms.

A cuproptosis-based nanomedicine suppresses triple negative breast cancers by regulating tumor microenvironment and eliminating cancer stem cells.

Cuproptosis is a new kind of cell death that depends on delivering copper ions into mitochondria to trigger the aggradation of tricarboxylic acid (TCA) cycle proteins and has been observed in various cancer cells. However, whether cuproptosis occurs in cancer stem cells (CSCs) is unexplored thus far, and CSCs often reside in a hypoxic tumor microenvironment (TME) of triple negative breast cancers (TNBC), which suppresses the expression of the cuproptosis protein FDX1, thereby diminishing anticancer efficacy of cuproptosis. Herein, a ROS-responsive active targeting cuproptosis-based nanomedicine CuET@PHF is developed by stabilizing copper ionophores CuET nanocrystals with polydopamine and hydroxyethyl starch to eradicate CSCs. By taking advantage of the photothermal effects of CuET@PHF, tumor hypoxia is overcome via tumor mechanics normalization, thereby leading to enhanced cuproptosis and immunogenic cell death in 4T1 CSCs. As a result, the integration of CuET@PHF and mild photothermal therapy not only significantly suppresses tumor growth but also effectively inhibits tumor recurrence and distant metastasis by eliminating CSCs and augmenting antitumor immune responses. This study presents the first evidence of cuproptosis in CSCs, reveals that disrupting hypoxia augments cuproptosis cancer therapy, and establishes a paradigm for potent cancer therapy by simultaneously eliminating CSCs and boosting antitumor immunity.

Sea buckthorn extract mitigates chronic obstructive pulmonary disease by suppression of ferroptosis via scavenging ROS and blocking p53/MAPK pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Sea buckthorn (Hippophae rhamnoides), a traditional Tibetan medicinal herb, exhibits protective effects against cardiovascular and respiratory diseases. Although Sea buckthorn extract (SBE) has been confirmed to alleviate airway inflammation in mice, its therapeutic effect and underlying mechanism on chronic obstructive pulmonary disease (COPD) requires further clarification. AIM OF THE STUDY: To elucidate the alleviative effect and molecular mechanism of SBE on lipopolysaccharides (LPS)/porcine pancreatic elastase (PPE)-induced COPD by blocking ferroptosis. METHODS: The anti-ferroptotic effects of SBE were evaluated in human BEAS-2B bronchial epithelial cells using CCK8, RT-qPCR, western blotting, and transmission electron microscopy. Transwell was employed to detect chemotaxis of neutrophils. COPD model was induced by intranasally administration of LPS/PPE in mice and measured by alterations of histopathology, inflammation, and ferroptosis. RNA-sequencing, western blotting, antioxidant examination, flow cytometry, DARTS, CETSA, and molecular docking were then used to investigate its anti-ferroptotic mechanisms. RESULTS: In vitro, SBE not only suppressed erastin- or RSL3-induced ferroptosis by suppressing lipid peroxides (LPOs) production and glutathione (GSH) depletion, but also suppressed ferroptosis-induced chemotactic migration of neutrophils via reducing mRNA expression of chemokines. In vivo, SBE ameliorated LPS/PPE-induced COPD phenotypes, and inhibited the generation of LPOs, cytokines, and chemokines. RNA-sequencing showed that p53 pathway and mitogen-activated protein kinases (MAPK) pathway were implicated in SBE-mediated anti-ferroptotic action. SBE repressed erastin- or LPS/PPE-induced overactivation of p53 and MAPK pathway, thereby decreasing expression of diamine acetyltransferase 1 (SAT1) and arachidonate 15-lipoxygenase (ALOX15), and increasing expression of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11). Mechanistically, erastin-induced elevation of reactive oxygen species (ROS) was reduced by SBE through directly scavenging free radicals, thereby contributing to its inhibition of p53 and MAPK pathways. CETSA, DARTS, and molecular docking further showed that ROS-generating enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) may be the target of SBE. Overexpression of NOX4 partially impaired the anti-ferroptotic activity of SBE. CONCLUSION: Our results demonstrated that SBE mitigated COPD by suppressing p53 and MAPK pro-ferroptosis pathways via directly scavenging ROS and blocking NOX4. These findings also supported the clinical application of Sea buckthorn in COPD therapy.

Tubeimoside-I, an inhibitor of HSPD1, enhances cytotoxicity of oxaliplatin by activating ER stress and MAPK signaling pathways in colorectal cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Tubeimoside-I (TBM) promotes various cancer cell death by increasing the reactive oxygen species (ROS) production. However, the specific molecular mechanisms of TBM and its impact on oxaliplatin-mediated anti-CRC activity are not yet fully understood. AIM OF THE STUDY: To elucidate the therapeutic effect and underlying molecular mechanism of TBM on oxaliplatin-mediated anti-CRC activity. MATERIALS AND METHODS: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, wound healing assays and flow cytometry were conducted to investigate the changes in cell phenotypes and ROS generation. Real-time quantitative PCR (qRT-PCR) and western blotting were performed to detect the expressions of related mRNA and proteins. Finally, mouse xenograft models demonstrated that synergistic anti-tumor effects of combined treatment with TBM and oxaliplatin. RESULTS: The synergistic enhancement of the anti-tumor effects of oxaliplatin in colon cancer cells by TBM involved in the regulation of ROS-mediated endoplasmic reticulum (ER) stress, C-jun-amino-terminal kinase (JNK), and p38 MAPK signaling pathways. Mechanistically, TBM increased ROS generation in colon cancer cells by inhibiting heat shock protein 60 (HSPD1) expression. Knocking down HSPD1 increased TBM-induced antitumor activity and ROS generation in colon cancer cells. The mouse xenograft tumor models further validated that the combination therapy exhibited stronger anti-tumor effects than monotherapy alone. CONCLUSIONS: Combined therapy with TBM and oxaliplatin might be an effective therapeutic strategy for some CRC patients.

Fluorescence and photoacoustic (FL/PA) dual-modal probe: Responsive to reactive oxygen species (ROS) for atherosclerotic plaque imaging.

Accurate and early detection of atherosclerosis (AS) is imperative for their effective treatment. However, fluorescence probes for efficient diagnosis of AS often encounter insufficient deep tissue penetration, which hinders the reliable assessment of plaque vulnerability. In this work, a reactive oxygen species (ROS) activated near-infrared (NIR) fluorescence and photoacoustic (FL/PA) dual model probe TPA-QO-B is developed by conjugating two chromophores (TPA-QI and O-OH) and ROS-specific group phenylboronic acid ester. The incorporation of ROS-specific group not only induces blue shift in absorbance, but also inhibits the ICT process of TPA-QO-OH, resulting an ignorable initial FL/PA signal. ROS triggers the convertion of TPA-QO-B to TPA-QO-OH, resulting in the concurrent amplification of FL/PA signal. The exceptional selectivity of TPA-QO-B towards ROS makes it effectively distinguish AS mice from the healthy. The NIR emission can achieve a tissue penetration imaging depth of 0.3 cm. Moreover, its PA775 signal possesses the capability to penetrate tissues up to a thickness of 0.8 cm, ensuring deep in vivo imaging of AS model mice in early stage. The ROS-triggered FL/PA dual signal amplification strategy improves the accuracy and addresses the deep tissue penetration problem simultaneously, providing a promising tool for in vivo tracking biomarkers in life science and preclinical applications.

pH-responsive and nanoenzyme-loaded artificial nanocells relieved osteomyelitis efficiently by synergistic chemodynamic and cuproptosis therapy.

Osteomyelitis is an osseous infectious disease that primarily affects children and the elderly with high morbidity and recurrence. The conventional treatments of osteomyelitis contain long-term and high-dose systemic antibiotics with debridements, which are not effective and lead to antibiotic resistance with serious side/adverse effects in many cases. Hence, developing novel antibiotic-free interventions against osteomyelitis (especially antibiotic-resistant bacterial infection) is urgent and anticipated. Here, a bone mesenchymal stem cell membrane-constructed nanocell (CFE@CM) was fabricated against osteomyelitis with the characteristics of acid-responsiveness, hydrogen peroxide self-supplying, enhanced chemodynamic therapeutic efficacy, bone marrow targeting and cuproptosis induction. Notably, mRNA sequencing was applied to unveil the underlying biological mechanisms and found that the biological processes related to copper ion binding, oxidative phosphorylation, peptide biosynthesis and metabolism, etc., were disturbed by CFE@CM in bacteria. This work provided an innovative antibiotic-free strategy against osteomyelitis through copper-enhanced Fenton reaction and distinct cuproptosis, promising to complement the current insufficient therapeutic regimen in clinic.

Selenium deficiency exacerbates ROS/ER stress mediated pyroptosis and ferroptosis induced by bisphenol A in chickens thymus.

Bisphenol A (BPA) is an industrial pollutant that can cause immune impairment. Selenium acts as an antioxidant, as selenium deficiency often accompanies oxidative stress, resulting in organ damage. This study is the first to demonstrate that BPA and/or selenium deficiency induce pyroptosis and ferroptosis-mediated thymic injury in chicken and chicken lymphoma cell (MDCC-MSB-1) via oxidative stress-induced endoplasmic reticulum (ER) stress. We established a broiler chicken model of BPA and/or selenium deficiency exposure and collected thymus samples as research subjects after 42 days. The results demonstrated that BPA or selenium deficiency led to a decrease in antioxidant enzyme activities (T-AOC, CAT, and GSH-Px), accumulation of peroxides (H2O2 and MDA), significant upregulation of ER stress-related markers (GRP78, IER 1, PERK, EIF-2α, ATF4, and CHOP), a significant increase in iron ion levels, significant upregulation of pyroptosis-related gene (NLRP3, ASC, Caspase1, GSDMD, IL-18 and IL-1ß), significantly increase ferroptosis-related genes (TFRC, COX2) and downregulate GPX4, HO-1, FTH, NADPH. In vitro experiments conducted in MDCC-MSB-1 cells confirmed the results, demonstrating that the addition of antioxidant (NAC), ER stress inhibitor (TUDCA) and pyroptosis inhibitor (Vx765) alleviated oxidative stress, endoplasmic reticulum stress, pyroptosis, and ferroptosis. Overall, this study concludes that the combined effects of oxidative stress and ER stress mediate pyroptosis and ferroptosis in chicken thymus induced by BPA exposure and selenium deficiency.

Oxidation-reduction process of Arabidopsis thaliana roots induced by bisphenol compounds based on RNA-seq analysis.

Bisphenol compounds (BPs) have various industrial uses and can enter the environment through various sources. To evaluate the ecotoxicity of BPs and identify potential gene candidates involved in the plant toxicity, Arabidopsis thaliana was exposed to bisphenol A (BPA), BPB, BPE, BPF, and BPS at 1, 3, 10 mg/L for a duration of 14 days, and their growth status were monitored. At day 14, roots and leaves were collected for internal BPs exposure concentration detection, RNA-seq (only roots), and morphological observations. As shown in the results, exposure to BPs significantly disturbed root elongation, exhibiting a trend of stimulation at low concentration and inhibition at high concentration. Additionally, BPs exhibited pronounced generation of reactive oxygen species, while none of the pollutants caused significant changes in root morphology. Internal exposure concentration analysis indicated that BPs tended to accumulate in the roots, with BPS exhibiting the highest level of accumulation. The results of RNA-seq indicated that the shared 211 differently expressed genes (DEGs) of these 5 exposure groups were enriched in defense response, generation of precursor metabolites, response to organic substance, response to oxygen-containing, response to hormone, oxidation-reduction process and so on. Regarding unique DEGs in each group, BPS was mainly associated with the redox pathway, BPB primarily influenced seed germination, and BPA, BPE and BPF were primarily involved in metabolic signaling pathways. Our results provide new insights for BPs induced adverse effects on Arabidopsis thaliana and suggest that the ecological risks associated with BPA alternatives cannot be ignored.

The Synergy between Antibiotics and the Nanoparticle-Based Photodynamic Effect.

Antimicrobial resistance (AMR) is a growing global health concern, necessitating innovative strategies beyond the development of new antibiotics. Here, we employed NdYVO4:Eu3+ nanoparticles, which can persistently produce reactive oxygen species (ROS) after stopping the light, as a model of photodynamic nanoparticles and demonstrated that the photodynamic effect can serve as an adjuvant with antibiotics to effectively reduce their minimum inhibitory concentration. These preirradiated nanoparticles could penetrate the bacterial cell membrane, significantly enhancing the potency of antibiotics. We showed that the synergy effect could be attributed to disrupting crucial cellular processes by ROS, including damaging cell membrane proteins, interfering with energy supply, and inhibiting antibiotic metabolism. Our findings suggested that complementing the photodynamic effect might be a robust strategy to enhance antibiotic potency, providing an alternative antibacterial treatment paradigm.

Tetraspanin 5 orchestrates resilience to salt stress through the regulation of ion and reactive oxygen species homeostasis in rice.

Tetraspanins (TETs) are integral membrane proteins, characterized by four transmembrane domains and a unique signature motif in their large extracellular loop. They form dynamic supramolecular complexes called tetraspanin-enriched microdomains (TEMs), through interactions with partner proteins. In plants, TETs are involved in development, reproduction and immune responses, but their role in defining abiotic stress responses is largely underexplored. We focused on OsTET5, which is differentially expressed under various abiotic stresses and localizes to both plasma membrane and endoplasmic reticulum. Using overexpression and underexpression transgenic lines we demonstrate that OsTET5 contributes to salinity and drought stress tolerance in rice. OsTET5 can interact with itself in yeast, suggesting homomer formation. Immunoblotting of native PAGE of microsomal fraction enriched from OsTET5-Myc transgenic rice lines revealed multimeric complexes containing OsTET5, suggesting the potential formation of TEM complexes. Transcriptome analysis, coupled with quantitative PCR-based validation, of OsTET5-altered transgenic lines unveiled the differential expression patterns of several stress-responsive genes, as well as those coding for transporters under salt stress. Notably, OsTET5 plays a crucial role in maintaining the ionic equilibrium during salinity stress, particularly by preserving an elevated potassium-to-sodium (K+/Na+) ratio. OsTET5 also regulates reactive oxygen species homeostasis, primarily by modulating the gene expression and activities of antioxidant pathway enzymes and proline accumulation. Our comprehensive investigation underscores the multifaceted role of OsTET5 in rice, accentuating its significance in developmental processes and abiotic stress tolerance. These findings open new avenues for potential strategies aimed at enhancing stress resilience and making valuable contributions to global food security.

The Negative Impact of Prolonged Desiccation on the Recovery of Selaginella bryopteris: Insights Into Autophagy and Cellular Protection Strategies.

Desiccation tolerance is a complex biological phenomenon that allows certain plants to survive extreme dehydration and revive upon rehydration. Although significant progress has been made in understanding the physiological and molecular mechanisms involved in desiccation tolerance, recovery mechanisms after prolonged desiccation periods are enigmatic. Combining physiological, biochemical, transcriptomic and metabolomic approaches, we investigated the role of prolonged desiccation on recovery of Selaginella bryopteris. Prolonged desiccation causes a decline in the antioxidant system, leading to accumulation of ROS that hinder recovery by inducing cellular damage. Transcriptome and WGCNA analysis revealed the significance of protective proteins, alternative respiration and protein homeostasis in cellular protection and recovery after short and long-term desiccation. Metabolomic analysis exhibited an increased accumulation of antioxidant compounds, which can be substituted for antioxidant enzymes to maintain cellular protection during prolonged desiccation. The significant role of autophagy and autophagic components was evaluated by H2O2 treatment and phylogenetic analysis of ATG4 and ATG8, which unveiled their substantial role in desiccation tolerance and remarkable conservation of the autophagy-related genes across plant species. Our data demonstrated that prolonged desiccation leads to ROS-induced cell death by extensive autophagy due to enormous loss of protective proteins, antioxidant enzymes and energy resources during desiccation.

Impact of Indole Inclusion in the Design of Multi-Tactical Metal-Binding Tetra-Aza Macrocycles that Target the Molecular Features of Neurodegeneration.

Numerous small molecules have been studied for their ability to counteract oxidative stress, a key contributor to neurodegenerative diseases such as Alzheimer's. Despite these efforts, the pharmacological properties and structure-activity relationships of these compounds remain insufficiently understood, yet they are critical in evaluating a drug molecule's therapeutic potential. A modified tetra-aza macrocycle has demonstrated strong antioxidant activity through various mechanisms; however, its limited permeability presents challenges for advanced formulation studies. To enhance permeability while preserving the beneficial reactivity of the parent molecule, two synthetic modifications involving indole functionality were explored and compared to modifications using methyl groups alone. New synthetic strategies were developed to produce the indole-containing molecules, which were characterized by 1D/2D NMR techniques. Isoelectric points, metal binding, and radical scavenging activity were determined to validate that the reactivity of the parent molecules was retained. The permeability of all molecules explored was improved. Protection against oxidative stress through activation of the Nrf2 pathway was demonstrated for molecules containing indoles in cellular models by measuring ROS levels upon treatment and mRNA levels of HO-1 and Nrf2. In contrast, no protection or Nrf2 activation was observed with the methylation of the O- or N atom. These results suggest that while alkylation improves permeability overall, concomitant antioxidant protection and positive permeability are achieved with the indole congeners alone.

ROS responsive conductive microspheres loaded with salvianolic acid B as adipose derived stem cell carriers for acute myocardial infarction treatment.

Stem cell therapy is currently the most promising strategy for the treatment of myocardial infarction. However, the development of injectable cell carriers that can scavenge reactive oxygen species (ROS) in the infarct zone to improve transplanted cell survival remains a challenge. Here, we developed a ROS responsive conductive microsphere based on chitosan (CS) and dextran (DEX) with 4-formylphenylboronic acid (4-FPBA) as a cross-linking agent and the addition of graphite oxide (GO) and the anti-inflammatory agent salvianolic acid B (SalB), as a cell delivery carrier for myocardial infarction. These microspheres were crosslinked by dual dynamic networks of Schiff base and phenylborate bonds. The relationship between CS concentration and microsphere particle size, as well as the biocompatibility, ROS responsiveness, anti-inflammatory properties, and effects on myogenic differentiation of H9C2 cells were fully investigated. The microspheres exhibit good biocompatibility, proliferation promoting, differentiation promoting, antioxidant, and anti-inflammatory properties. When applied to mice myocardial infarction models, the ROS responsive conductive microspheres loaded with SalB and adipose derived stem cells (ADSC) exhibited excellent in vivo repair ability. In addition, they reduced myocardial fibrosis and promoted ventricular wall regeneration by promoting the expression of Connexin 43 (Cx43) and CD31, ultimately reshaping the infarcted myocardium, suggesting their great potential as cell delivery carriers for myocardial infarction treatment.

Comprehensive eco-geno-toxicity and environmental risk of common antiviral drugs in aquatic environments post-pandemic.

The eco-geno-toxicological impacts of the most widely used antiviral drugs against SARS-CoV2 - ribavirin, ritonavir, nirmatrelvir and tenofovir - were investigated in freshwater organisms. Ribavirin and tenofovir exhibited the highest acute toxicity in the rotifer Brachionus calyciflorus at concentrations of a few mg/L while ritonavir and nirmatrelvir showed similar effects at tens of mg/L; acute toxicity of ribavirin was also observed in the crustacean Ceriodaphnia dubia at similar concentrations. In contrast, the crustacean Thamnocephalus platyurus showed the lowest sensitivity to the antiviral drugs tested with no sublethal effects. Chronic toxicity tests revelead that these antivirals induced effects in consumers at concentrations of environmental concern (ng-µg/L). Ribavirin showed the highest toxicity to the alga Raphidocelis subcapitata, while ritonavir showed the highest toxicity to B. calyciflorus and C. dubia. DNA damage and oxidative stress were observed in C. dubia at 0.001 µg/L and 0.1 µg/L when exposed to ritonavir and nirmatrelvir respectively, and at 1 µg/L when exposed to ribavirin and tenofovir. Toxic and genotoxic environmental risks were assessed with risk quotients for ritonavir, tenofovir and ribavirin exceeding the threshold of 1, indicating significant environmental concern.

Berberine extends healthspan and delays neurodegenerative diseases in Caenorhabditis elegans through ROS-dependent PMK-1/SKN-1 activation.

Oxidative stress, or the chronic generation of reactive oxygen species (ROS), is thought to contribute to the progression of aging and aging related diseases. However, low degree of ROS generation has repeatedly been shown to be associated with beneficial outcomes via activation of protective signaling pathways. Berberine, a natural alkaloid isolated from Rhizomacoptidis, has a long history of medicinal use in both Ayurvedic and traditional Chinese medicine, which possesses anti-cancer, anti-inflammatory and anti-neurodegenerative properties. In this study, we utilize Caenorhabditis elegans to examine the mechanisms by which berberine influences healthspan and neurodegenerative diseases. We find that 10 µM berberine significantly extends healthy lifespan in wild type C. elegans. We further show that berberine generates ROS, which is followed by activation of PMK-1/SKN-1 to extend healthspan. Intriguingly, berberine also delays neurodegenerative diseases such as Alzheimer's and polyglutamine diseases in a PMK-1/SKN-1dependent manner. Our work suggests that berberine may be a viable candidate for the prevention and treatment of aging and aging related diseases.

Singlet oxygen-mediated photochemical cross-linking of an engineered fluorescent flavoprotein iLOV.

Genetically-encoded photoactive proteins are integral tools in modern biochemical and molecular biological research. Within this tool box, truncated variants of the phototropin 2 light-oxygen-voltage (LOV) flavoprotein have been developed to photochemically generate singlet oxygen (1O2) in vitro and in vivo, yet the effect of 1O2 on these genetically encoded photosensitizers remains underexplored. In this study, we demonstrate that the "improved" LOV (iLOV) flavoprotein is capable of photochemical 1O2 generation. Once generated, 1O2 induces protein oligomerization via covalent cross-linking. The molecular targets of protein oligomerization by cross-linking are not endogenous tryptophans or tyrosines, but rather primarily histidines. Substitution of surface-exposed histidines for serine or glycine residues effectively eliminates protein cross-linking. When used in biochemical applications, such protein-protein cross-links may interfere with native biological responses to 1O2, which can be ameliorated by substitution of the surface exposed histidines of iLOV or other 1O2-generating flavoproteins.

The power of small: microRNAs modulating stomatal movement.

Regulation of stomatal aperture is paramount in drought-stress responses. Recently, Yang et al. demonstrated how microRNA-plantacyanin (PCY) regulates stomata movement by revealing a novel mechanism responsive to abscisic acid (ABA) that controls reactive oxygen species (ROS) in guard cells. This sets a precedent for using miRNAs as a new target for stress-resistance genetic engineering.

Synergistic Gas Therapy and Targeted Interventional Ablation With Size-Controllable Arsenic Sulfide (As2S3) Nanoparticles for Effective Elimination of Localized Cancer Pain.

The elimination of localized cancer pain remains a globally neglected challenge. A potential solution lies in combining gas therapy with targeted interventional ablation therapy. In this study, HA-As2S3 nanoparticles with controlled sizes are synthesized using different molecular weights of sodium hyaluronate (HA) as a supramolecular scaffold. Initially, HA co-assembles with arsenic ions (As3+) via coordinate bonds, forming HA-As3+ scaffold intermediates. These intermediates, varying in size, then react with sulfur ions to produce size-controlled HA-As2S3 particles. This approach demonstrates that different molecular weights of HA enable precise control over the particle size of arsenic sulfide, offering a straightforward and environmentally friendly method for synthesizing metal sulfide particles. In an acidic environment, HA-As2S3 nanoparticles release hydrogen sulfide(H2S) gas and As3+. The released As3+ directly damage tumor mitochondria, leading to substantial reactive oxygen species (ROS) production from mitochondria. Concurrently, the H2S gas inhibits the activity of catalase (CAT) and complex IV, preventing the beneficial decomposition of ROS and disrupting electron transfer in the mitochondrial respiratory chain. Consequently, it is found that H2S gas significantly enhances the mitochondrial damage induced by arsenic nanodrugs, effectively killing local tumors and ultimately eliminating cancer pain in mice.