Antioxidants

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in older adults. It is characterised by early retinal pigment epithelium (RPE) dysfunction followed by progressive photoreceptor degeneration. Cigarette smoking is a major environmental risk factor for AMD, and hydroquinone (HQ), a redox-active cigarette smoke component, induces oxidative stress and apoptosis in RPE cells. To analyse how RPE stress contributes to photoreceptor degeneration, we employed a retinal co-culture model composed of human induced pluripotent stem cell-derived RPE (iPSC-RPE) cells in conjunction with porcine neuroretina explants. Exposure to HQ induced oxidative stress in iPSC-RPE cells as well as retinal photoreceptors (RPR), resulting in apoptosis, executed at least in part by caspase activation. Concomitantly, HQ caused endoplasmic reticulum (ER) stress (ERAD) in RPR followed by their degeneration, evidenced by reduced outer nuclear layer (ONL) rows and shortened RPR outer segments (OS). Based on earlier results, which suggest a perturbation of proteostasis due to HQ, we tested whether ML240, a bona fide inhibitor of valosin-containing protein (VCP), would influence the degree of degenerative activities. ML240 did not prevent HQ-induced apoptosis in iPSC-RPE cells. However, it significantly preserved photoreceptor integrity, retaining OS length and cone density in HQ-stressed co-cultures. Proteomic analysis suggested that ML240 reshapes stress response patterns of the HQ-exposed neuroretina, as evidenced by a reduction in ERAD-associated markers, increased levels of antioxidant response proteins, and the preservation of cytochrome c enrichment in photoreceptor inner segments, which indicates improved mitochondrial integrity consistent with the observed preservation of photoreceptor structure. Together, these findings establish the iPSC-RPE/neuroretina co-culture as a platform to analyse pathophysiological features of AMD, dissect cell type-specific retinal responses to environmental stress and test neuroprotective pharmacological approaches to protect photoreceptors in oxidative stress-associated retinal degeneration.

Animals experience stressors in a variety of contexts that result in activation of neuroendocrine and cellular stress responses. Release of stress hormones can disrupt or restore redox homeostasis, and the resulting changes in oxidative states, physiology and behavior vary by an individuals stress coping style. However, oxidative stress can also directly modulate neuroendocrine stress signaling. To what extent individual differences in brain antioxidant levels alter behavioral stress levels is not well understood. The present study investigated how N-acetylcysteine amide (NACA), an antioxidant and glutamate-modulating compound, regulates stress behavior across zebrafish (Danio rerio) with different stress coping styles (proactive, reactive). Following 24-hour exposure to NACA or control conditions, we quantified individual and composite stress behaviors using a Light-Dark Test (LDT). As expected, both proactive fish and NACA-treated fish showed significantly lower stress behaviors compared to reactive and control animals, respectively. Notably, stress-reducing effects of NACA were only seen in those with a reactive stress coping style. Overall, our data suggest that antioxidant mechanisms (e.g., glutathione system) may be key in facilitating the distinct behavioral and physiological responses to stressors that characterize alternative stress coping styles. The results underscore how individual differences in stress coping style and redox state can influence behavioral responses to stress.

Kakadu plum (Terminalia ferdinandiana), an Australian native fruit, is among the richest known dietary sources of vitamin C and hydrolysable tannins, yet its capacity to protect the intestinal epithelium against oxidative stress remains largely unexplored. This study optimised the extraction of bioactive compounds from freeze-dried Kakadu plum powder and evaluated their antioxidant activity using both chemical and cellular antioxidant in vitro assay. Phenolic compounds were extracted using three solvents (water, 80% ethanol, and 80% methanol) combined with shaking, ultrasound, or microwave assistance. Solvent, rather than processing technique, was the dominant determinant of antioxidant capacity: ethanol and methanol maximised total phenolic content, total flavonoid content, and DPPH radical-scavenging activity, whereas water extracts showed the highest ferric-reducing antioxidant power. Twenty-four phenolic compounds identified by HPLC-ESI-QTOF-MS/MS were mapped by network pharmacology to nine core oxidative-stress targets, and cross-species molecular docking predicted conserved binding of key phenolics to canine orthologs of PTGS2 and MMP2. In an H2O2-induced oxidative-stress in vitro cell model using canine small intestinal epithelial cells, both water (less than 25 ug/mL) and ethanol (less than 250 ug/mL) extracts significantly suppressed intracellular reactive oxygen species (ROS) in a dose-dependent manner, with the ethanol extract effective across a wider concentration range. This work demonstrated that Kakadu plum extract could be a promising natural, multi-target antioxidant ingredient for canine intestinal health, and provided a reference for future in vivo research.

Objective White smoke inhalation injury (WSI) causes severe acute lung damage with no specific therapy currently available. Sphingolipid metabolism is implicated in pulmonary inflammation, but its transcriptional regulatory landscape in WSI remains unexplored. This study aimed to identify key sphingolipid metabolism related genes and evaluate their regulatory roles and therapeutic potential in WSI. Methods We established a rat model of WSI and performed integrated bulk RNA sequencing, weighted gene coexpression network analysis (WGCNA), and single-cell RNA sequencing (scRNAseq) to screen for differentially expressed sphingolipid metabolism-related genes (DESRGs). Protein-protein interaction (PPI) network with four centrality algorithms was used to prioritize hub genes. In silico gene knockout and molecular docking were conducted to assess regulatory functions and identify potential drug candidates. Results We identified 22 DESRGs that were predominantly enriched in DNA replication and cell cycle pathways rather than canonical sphingolipid metabolic processes. PPI consensus prioritized three hub genes--Top2a, Ttk, and Ccna2--with Top2a exhibiting the highest expression in epithelial cells and significant downregulation after smoke exposure. ScRNAseq revealed immune cell infiltration and epithelial differentiation trajectories. Virtual knockout showed that Top2a depletion affected the largest transcriptomic fraction (~0.4%) and was enriched in lysosome biogenesis, innate immunity, phagocytosis, and lipid catabolism. Molecular docking identified thalidomide as a high affinity ligand for Top2a (Vina score: -8.5 kcal/mol). Conclusion Our multiomics integrative framework identifies Top2a as a central regulatory hub linking sphingolipid associated inflammation to epithelial responses in WSI, and nominates thalidomide as a potential drug repurposing candidate. These findings provide prioritized targets for future translational investigation.

BackgroundHydrogen sulfide (H2S) is an important endothelial-derived vasodilator, but the signaling mechanism remains incompletely understood. We previously demonstrated that H2S-mediated vasodilation requires transient receptor potential vanilloid type 4 (TRPV4) channels. Because H2S has been reported to enhance heme oxygenase (HO) activity and HO-derived carbon monoxide (CO) regulates endothelial signaling, we hypothesized that H2S-mediated vasodilation requires HO-2-derived CO. MethodsPressure myography was performed in isolated rat mesenteric arteries to determine the contribution of HO, TRPV4, eBK, and SK/IK channels to H2S-mediated vasodilation. HO-2 sulfhydration was assessed using a maleimide assay, and spatial association among HO-2 and TRPV4 was examined using proximity ligation assays in human aortic endothelial cells. ResultsH2S Selicited concentration-dependent vasodilation that was abolished by HO inhibition. Repletion of CO restored H2S-mediated vasodilation in the presence of HO inhibition. CO-mediated vasodilation was abolished by TRPV4 and SK/IK inhibition but was unaffected by eBK inhibition. H2S increased HO-2 sulfhydration and enhanced HO activity. In endothelial cells, HO-2 and TRPV4 exhibited close spatial association. ConclusionsThese findings support a model in which H2S stimulates HO-2-derived CO production, leading to TRPV4-dependent endothelial signaling, SK/IK activation, and vasodilation. Together, the data support the existence of an endothelial HO-2/TRPV4/SK/IK signaling domain that contributes to H2S-mediated vascular reactivity.

Purpose: Oxidative stress is thought to contribute to the development of age-related cataracts (ARCs), but the mechanisms by which oxidative damage leads to the opacification of the lens remain unclear. Previous studies suggest that oxidative stress can disrupt lens proteostasis. Therefore, it was hypothesized that ARCs arise from proteomic changes driven by an age-associated decline in oxidative stress defenses that interact with the lens proteostatic state. To test this hypothesis, proteomic analyses of lenses exposed to oxidative stress were performed to examine oxidative and proteostatic stress responses in vivo. Methods: Cataract formation was induced by injecting hydrogen peroxide into the aqueous humor of adult zebrafish. nrf2fh318/fh318 zebrafish were used to model the reduced oxidative stress protection observed in aged human lenses, while cryaba-/- zebrafish were used to model impaired lens proteostasis. Resulting opacities in WT, cryaba-/-, nrf2fh318/fh318, and cryaba-/-; nrf2fh318/fh318 lenses were quantified and proteomic changes in the cortex were analyzed using data independent acquisition Parallel Accumulation Serial Fragmentation mass spectrometry. Results: Hydrogen peroxide treatment induced the formation of cortical cataracts. Proteomic results showed that, dependent on genotype and day, oxidative stress activates the unfolded and mitochondrial unfolded protein responses. Additional changes were also observed in energy metabolism, Ca2+ homeostasis, protein degradation, and cytoskeletal and extracellular matrix remodeling pathways. Conclusions: Treated zebrafish lenses successfully model ARC and mass spectrometry proteomics identified the unfolded and mitochondrial unfolded protein responses as potential therapeutic targets for ARC.

The rise of antimicrobial resistance has intensified interest in antimicrobial photodynamic inactivation (aPDI) and antimicrobial blue light (aBL) as alternatives or adjuvants to conventional antibiotics. However, whether chemically distinct photodynamic treatments elicit a shared bacterial response remains unclear. Here, we integrated transcriptomic profiles of Escherichia coli BW25113 exposed to five short-term, sub-lethal photodynamic treatments: antimicrobial blue light (aBL), aBL combined with 5-aminolevulinic acid (aBL+ALA), rose bengal (RB), new methylene blue (NMB), and the cationic porphyrin TMPyP. Intersection analysis identified 891 conserved core genes differentially expressed across all treatments, of which approximately 98% changed in a consistent direction despite differences in photosensitizer chemistry and activating wavelength. Random-effects meta-analysis and robust rank aggregation prioritized 88 high-confidence genes, revealing induction of envelope stress and cytoplasmic protein quality control pathways alongside repression of acid resistance, hydrogen metabolism, molybdate transport, and biofilm formation. Regulon enrichment indicated that heat-shock sigma factor {sigma}32/RpoH and the envelope-stress regulators CpxR, BaeR, {sigma}24/RpoE, and PspF were enriched among induced genes, whereas GadW/GadX/GadE, Fur, and {sigma}38/RpoS were enriched among repressed genes. Functional validation using selected single-gene Keio knockouts confirmed that deletion of conserved-core genes sensitized E. coli to photodynamic treatment and delayed post-treatment recovery in a modality-dependent manner. Moreover, RT-qPCR analysis of selected transcriptional responses confirmed the direction and overall pattern of RNA-seq-derived expression changes. Together, these findings define a unified conserved early survival program in E. coli after chemically distinct photodynamic treatments and identify stress-response modules that may serve as targets for potentiating aPDI. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=126 SRC="FIGDIR/small/744726v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@dbbadaorg.highwire.dtl.DTLVardef@1c85538org.highwire.dtl.DTLVardef@152d699org.highwire.dtl.DTLVardef@18705a6_HPS_FORMAT_FIGEXP M_FIG C_FIG

Plants make diverse metabolites to outcompete neighboring organisms for space and resources. Some of these toxic metabolites broadly disrupt conserved molecular mechanisms, such as protein biosynthesis. Nonproteogenic amino acids (NPAAs) are a structurally diverse class of metabolites that interfere with protein biosynthesis. The proline (Pro) analog azetidine-2-carboxylic acid (Aze) inhibits plant growth through misincorporation during protein biosynthesis. However, it is unknown if a cascade of downstream stress responses is triggered following Aze misincorporation. Here, we investigate the morphological and stress responses in Arabidopsis grown on Aze. Investigation of root morphological responses show not only reduced root growth, but increased root branching following growth on Aze. Altered root morphology is coupled with a reduced gravitropic response. Aboveground organs were also affected by Aze, including reduced chlorophyll content, reduced photosynthetic efficiency, and increased anthocyanin content. We then tested whether Aze induces reactive oxygen species (ROS) accumulation using multiple approaches and observed both immediate and sustained accumulation of general ROS and H2O2 following treatment with Aze. When plants were grown on Aze supplemented with Pro, ROS levels were restored to normal levels, suggesting that reducing misincorporation events results in less downstream stress responses. In summary, we find that following Aze treatment a cascade of downstream stress responses is induced that exacerbates the effects of toxic NPAAs. This study sheds light on the mechanism of action of NPAAs and provides information on the downstream consequences of translational errors.

This study aims to investigate the cardioprotective effects of 4-Hydroxybenzaldehyde (4-HBA) against isoproterenol (ISO)-induced cardiac fibrosis and to elucidate the underlying mechanisms. In vivo, cardiac fibrosis was induced in C57BL/6 mice by subcutaneous injection of ISO, and the mice were treated with 4-HBA or a TGF-{beta} inhibitor. Assessments using echocardiography, histopathology, and Western blotting demonstrated that 4-HBA significantly alleviated ISO-induced cardiac dysfunction, reduced collagen deposition, and attenuated apoptosis in mice. Mechanistically, 4-HBA inhibited TGF-{beta} expression and Smad2/3 phosphorylation. In vitro, ISO was applied to cardiomyocytes (HL-1) and cardiac fibroblasts (MCFs), with or without 4-HBA or TGF-{beta} inhibitor intervention. The results showed that 4-HBA suppressed HL-1 apoptosis and fibroblast proliferation, and significantly reduced the expression of extracellular matrix genes, TGF-{beta} levels, and Smad2/3 phosphorylation in MCFs. These findings indicate that 4-HBA reduces myocardial injury while targeting the TGF-{beta}/Smad2/3 pathway to attenuate cardiac fibrosis, highlighting its potential as a therapeutic agent for fibrotic cardiomyopathy.This study aims to investigate the cardioprotective effects of 4-Hydroxybenzaldehyde (4-HBA) against isoproterenol (ISO)-induced cardiac fibrosis and to elucidate the underlying mechanisms. In vivo, cardiac fibrosis was induced in C57BL/6 mice by subcutaneous injection of ISO, and the mice were treated with 4-HBA or a TGF-{beta} inhibitor. Assessments using echocardiography, histopathology, and Western blotting demonstrated that 4-HBA significantly alleviated ISO-induced cardiac dysfunction, reduced collagen deposition, and attenuated apoptosis in mice. Mechanistically, 4-HBA inhibited TGF-{beta} expression and Smad2/3 phosphorylation. In vitro, ISO was applied to cardiomyocytes (HL-1) and cardiac fibroblasts (MCFs), with or without 4-HBA or TGF-{beta} inhibitor intervention. The results showed that 4-HBA suppressed HL-1 apoptosis and fibroblast proliferation, and significantly reduced the expression of extracellular matrix genes, TGF-{beta} levels, and Smad2/3 phosphorylation in MCFs. These findings indicate that 4-HBA reduces myocardial injury while targeting the TGF-{beta}/Smad2/3 pathway to attenuate cardiac fibrosis, highlighting its potential as a therapeutic agent for fibrotic cardiomyopathy.

Background: Natural compounds from avocado fruit (avocadene, avocadyne, and acetate derivatives) exhibit notable biological activity, although their molecular mechanisms remain unclear. The avocado-derived lipids exert potent nematocidal activity against several parasitic nematodes. In Caenorhabditis elegans (C. elegans), those compounds caused concentration-dependent toxicity, impairing first stage larval growth, egg hatching, and adult survival. Treated worms exhibited impaired mitochondrial respiration, reduced oxygen consumption, and elevated reactive oxygen species. These effects suggest that avocado lipids disrupt mitochondrial function and lipid metabolism, in part by inhibiting acetyl-CoA carboxylase, the rate-limiting enzyme of fatty acid biosynthesis. Methods: We investigated the effects of these compounds on the lipid profile of C. elegans and their association with endogenous lipid pools using NMR spectroscopy, click-chemistry-based fluorescence labeling, thin-layer chromatography (TLC), and microscopy. Results: Lipidomic analysis of stage 4 larvae (L4) and embryos treated with avocadene acetate revealed increased lipid NMR signals. Fluorescence-assisted TLC and NMR further suggested that avocadyne preferentially associates with triglyceride-linked fatty acids, particularly monounsaturated and flexible polyunsaturated chains, without detectable interactions with conformationally-constrained polyunsaturated species. Fluorescent avocadyne derivatives were efficiently internalized with distinct localization patterns in L4 larvae and embryonic cells. Conclusions: Overall, the lipid homeostasis remodeling of L4 larvae in response to lipotoxic shock was associated with phospholipid increase and remarkable lipid droplets onset, whereas embryos showed accumulation of lipids in enlarged droplets and developmental arrest.

Cardiolipin (CL) is a phospholipid found in the inner mitochondrial membrane (IMM) where it increases the efficiency of ATP regeneration. We have investigated the hypothesis that this increase may result in part from CL concentrating H+ at the IMM surface through electrostatic interactions as the CL polar head is a dianion at physiological pH. To this aim, we compared the concentrations and movements of H+ at the surface of giant planar phosphatidylcholine (PC) membranes and 20% CL enriched PC membranes by recording their surface pH with the membrane-grafted pH probe fluorescein DHPE. CL enrichment of the membranes increased their surface H+ activity by a ~4 factor. Moreover, we observed non-gaussian spatial H+ concentration profiles with distance from a point H+ source with both PC and CL membranes suggesting that both lipids also induce interactions between probe molecules. A whole bath pH variation revealed that these interactions allow the traveling of reversible acidification fronts with constant speed over the membrane between high and low pH states. A reaction-diffusion model of these observations suggests that membranes support these fronts through a mechanism of autocatalytic (de)protonation of the membrane surface. In mitochondria, these fronts would result in transitions between high and low pH states, the low one having a larger H+ concentration in CL-enriched regions of the IMM. Such an increase at the inner leaflet of the IMM may increase efficiency of the respiratory chain whereas the increase at the outer leaflet may boost the ATP synthase rate.

People are widely exposed to the antimicrobial cetylpyridinium chloride (CPC) via consumer products, but CPC is a mitochondrial toxicant with potency comparable to that of canonical mitotoxicants. CPC is largely unregulated despite growing usage, bioavailability, and ability to cross the blood-brain barrier. Previously, we showed, in several cell types at non-cytotoxic and exposure-relevant doses, CPC inhibits ATP and OCR, endpoints of the electron transport chain (ETC). Mitochondrial toxicity is linked to multiple diseases (e.g., diabetes, Parkinsons, myalgic encephalomyelitis), but CPC has not been studied epidemiologically, and little mechanistic information is available. To determine why OCR and ATP are hampered by CPC, we hypothesized that CPC inhibits individual ETC components, cardiolipin, or TCA enzymes. Here, we show that, in primary human skin cells, an immune mast cell model, and isolated mitochondria, CPC apparently inhibits multiple ETC Complexes. Detailed investigation pinpointed the mechanism to the distal end of ETC: Complex III-cytochrome C-Complex IV. Using multiple approaches, we show that CPC does not directly inhibit any of the Complexes (not even Complex I as earlier reported), nor TCA enzymes, nor coenzyme Q. Yet, we found that CPC exhibits mitotoxicity as potent as cyanide. Anionic lipid cardiolipin attracts cytochrome C to the inner mitochondrial membrane so that it may shuttle electrons from Complex III to IV. Despite not altering levels of cardiolipin, CPC hinders cytochrome C by electrostatically interfering with cardiolipin. To aid epidemiology, risk analysis, and predictive toxicology, we have determined the precise biochemical mechanism of action of this ubiquitous compound.

Parkinson's disease (PD) is a progressive neurodegenerative condition characterized by the loss of dopaminergic (DA) neurons and alpha-synuclein aggregation, with ferroptosis playing a critical pathological role. This study investigated the neuroprotective potential of Kocuria rhizophila strain CDMP12, a marine bacterium isolated from the Gulf of Mannar, India, using Caenorhabditis elegans models of PD. Dietary supplementation with K. rhizophila (CDMP12) significantly preserved DA neuron structure, rescued neuro-sensory and motor deficits, and attenuated both alpha-synuclein expression in the C. elegans models. Transcriptomic and qRT-PCR analyses revealed that CDMP12 systematically suppressed ferroptosis by significantly downregulating iron and lipid regulatory genes such as smf-3, ftn-1, and acs-4, while upregulating the protective antioxidant gene gpx-1. Furthermore, BODIPY staining demonstrated that CDMP12 treatment markedly reduced lipid peroxidation, lowering the oxidized-to-non-oxidized lipid ratio in PD worms. Collectively, these findings identify K. rhizophila (CDMP12) as a promising marine-derived neuroprotective candidate that mitigates PD-associated pathology, accompanied by reduced alpha-synuclein burden, preservation of DA neuronal function, and attenuation of ferroptosis-associated molecular and lipid peroxidation signatures.

Cigarette smoke-induced lung inflammation is a central driver of pulmonary diseases. The limited efficacy of current anti-inflammatory agents underscores the need for structurally novel therapeutics with distinct mechanisms. We recently demonstrated that AB-free kava, a flavokavains A/B-depleted formulation from Piper methysticum containing six major kavalactones, effectively suppresses cigarette smoke-induced lung inflammation in mice. This study aims to identify the bioactive constituent(s) and elucidate underlying mechanisms. These kavalactones revealed a clear structure-activity relationship in suppressing lipopolysaccharide (LPS)-stimulated prostaglandin E2 (PGE2) production in macrophages with desmethoxyyangonin (DMY) as the most potent kavalactone whereas dihydrokavain (DHK, a structurally similar analog) with minimal activity. DMY also effectively reduced LPS-induced interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-) production while DHK was ineffective. Mechanistically, DMY, but not DHK, attenuated COX-2 induction and reduced phosphorylation of cAMP response element-binding protein (CREB). Pharmacological inhibition of protein kinase A (PKA) similarly reduced p-CREB, COX-2 and PGE2, supporting a PKA-dependent CREB/COX-2 signaling in mediating PGE2 suppression while these effects were independent of nuclear factor kappa B (NF-{kappa}B) and activator protein 1 (AP-1) signaling. Similar results were observed for DMY and DHK in attenuating cigarette smoke condensate-induced proinflammatory pathways and PGE2 production. Consistently, DMY demonstrated significant in vivo efficacy in suppressing cigarette smoke-induced lung inflammation while DHK was not effective. Interestingly, dihydromethysticin (DHM) demonstrated the greatest in vivo anti-inflammatory efficacy, although it only exhibited moderate in vitro potency, likely due to its superior bioavailability over DMY. Concordantly, cigarette smoke exposure elevated p-CREB and COX-2 expressions in mouse lungs, which were attenuated by AB-free kava and its bioactive kavalactones with the extent of suppression correlating with their in vivo anti-inflammatory efficacy. DHM effectively suppressed LPS-induced neutrophil accumulation in mouse lungs as well. Collectively, these studies identify bioactive kavalactones in AB-free kava that suppress cigarette smoke- and LPS-induced lung inflammation through the modulation of the PKA/CREB/COX-2 signaling axis, providing a foundation for developing structurally distinct anti-inflammatory agents, particularly targeting smoke-induced inflammation and associated pulmonary diseases.

Early life stress (ELS) in the form of adverse experiences in childhood results in multiple psycho-physiological pathologies during adulthood and accelerates aging. Such pathologies are recently observed to be alleviated upon nicotinamide treatment in a maternal separation model of ELS. We report a nicotinamide-driven amelioration of gut dysbiosis in middle-aged rodents with a history of neonatal maternal separation.

Therapy of ischemic stroke is currently limited to pharmacological and/or mechanical recanalization. There are no neuroprotective therapies approved for use during the rehabilitative phase of ischemic stroke, which is characterized by neurodegenerative changes. Thus, the search for neuroprotective compounds capable of preventing neuronal death caused by pathogenetic cascades triggered during hypoxia is an urgent task. In this study, we demonstrate increased culture viability following pre- and post-incubation with salicyl-carnosine (SC) in a model of oxygen glucose deprivation on a primary culture of rat cortical neurons. Its neuroprotective properties were greater than that of acetylsalicylic acid and carnosine, and it was effective in lower concentrations. In addition, SC protected the culture from NMDA-induced excitotoxicity. We also showed the passage of SC into neurons, and the presence of its direct antioxidant activity in a model of paraquat-induced oxidative stress. The neuroprotective effects of SC are associated with a decrease in the level of pro-apoptotic protein Bak and a decrease in the activation of kinase p38, as well as an increase in the activation of kinase ERK1/2. The acquired data suggests that SC is a promising neuroprotective compound, and warrants further investigation in vivo.

O_LIVitamin B12, an essential micronutrient for many microalgae and humans, is synthesised only by certain prokaryotes. B12 is a complex tetrapyrrole that can exist in many forms (vitamers), some more bioavailable than others. Some microalgae are able to interconvert, or remodel, different B12 vitamers. As microalgae are important primary producers, it is crucial to understand how diverse microalgae acquire, utilise, and remodel this micronutrient. C_LIO_LIThrough the development of a novel algal bioassay for B12 quantification that distinguishes between B12 vitamers with different lower axial ligands, and the generation of targeted knock-out lines, we characterised the role of proteins involved in algal B12 uptake and remodelling. C_LIO_LIWe found that the previously characterised protein CoBalamin-Acquisition protein 1 (CBA1) is also necessary for the acquisition of pseudocobalamin, a less bioavailable form of B12. In addition, we provide the first experimental evidence that COBT is required for Chlamydomonas reinhardtii to remodel B12. C_LIO_LIWe apply the algal B12 bioassay to show that the edible alga Chlorella vulgaris can accumulate pseudocobalamin but is unable to remodel it, highlighting the need for thorough investigation of the metabolic requirements and capabilities of microalgae, especially given the growing interest in microalgae-based food additives. C_LI

Green synthesis of zinc oxide nanoparticles (ZnO NPs) offers a sustainable strategy for developing multifunctional antimicrobial nanomaterials. In this study, ZnO NPs were synthesized using Azadirachta indica leaf extract and characterized by UV-vis spectroscopy, FTIR, XRD, SEM, and GC-MS. The nanoparticles exhibited a characteristic absorption peak at 352 nm, a direct band gap of 3.07 eV, and hexagonal wurtzite crystallinity with an average crystallite size of approximately 32 nm. The biosynthesized ZnO NPs showed concentration-dependent antibacterial activity against Erwinia carotovora, producing inhibition zones of up to 25.9 mm. Mechanistic studies revealed significant membrane damage, evidenced by 4.77-fold and 5.62-fold increases in extracellular protein and amino acid leakage, respectively, with marked alterations in bacterial protein profiles detected by SDS-PAGE. The nanoparticles also exhibited strong antioxidant activity, achieving 89.4% DPPH radical scavenging, and induced dose-dependent cytotoxicity in HepG2 cells with an estimated IC50 of 124.8 g/mL. These findings demonstrate that neem-mediated ZnO nanoparticles possess potent antibacterial activity through membrane disruption while exhibiting promising antioxidant properties, highlighting their potential as eco-friendly nanomaterials for the management of bacterial soft rot and other phytopathogenic diseases.

Background: Cardiometabolic multimorbidity (CMM), which refers to having two or more cardiometabolic conditions like type 2 diabetes, stroke, and coronary heart disease, is becoming an increasing global health challenge. Although metabolic dysfunction and biological aging may jointly contribute to CMM development, most previous studies have examined these dimensions separately. Whether their combined assessment improves risk stratification and prediction across the cardiometabolic disease continuum remains unclear. Methods: This prospective cohort study involved 8,767 participants aged 45 and older who did not have CMM at the start, as part of the China Health and Retirement Longitudinal Study (CHARLS). Baseline evaluations included the triglyceride-glucose (TyG) index and two biological age algorithms, Light BA and KDM BA. The residual from regressing biological age on chronological age was used to derive BAA. Continuous TyG BA composite indices were constructed as the products of TyG and biological age. Cumulative exposure and two wave trajectory analyses used repeated measurements from 2011 and 2015. Multistate models examined associations across the cardiometabolic disease continuum. Cox proportional hazards models, along with restricted cubic splines and time dependent discrimination analyses, were utilized to examine associations, dose response relationships, and incremental predictive performance. Results: During a median follow-up span of 108 months, 873 participants were newly diagnosed with CMM. TyG and biological age were independently associated with CMM, with mutually adjusted hazard ratios of 1.23 to 1.27 and 1.39 to 1.44 per standard deviation increase, respectively. Individuals with elevated TyG and rapid biological aging faced the greatest CMM risk, showing hazard ratios of 2.37 for Light BA and 2.26 for KDM BA, despite the absence of a significant multiplicative interaction. Continuous TyG BA composites were associated with 49% to 62% higher CMM risk per standard-deviation increase, with more than threefold higher risk in the highest versus lowest quartile and nonlinear dose response relationships. Significantly increased CMM risk was linked to higher cumulative exposure and elevated two wave trajectory levels, with hazard ratios ranging from 3.93 to 5.17 when comparing the highest and lowest exposure groups. Multistate analyses demonstrated consistent associations of the composites with transitions across the cardiometabolic disease continuum and with mortality. Adding TyG BA composites to the prespecified clinical model increased the Cindex by 0.015 to 0.024 and improved net clinical benefit, but did not improve discrimination beyond models containing TyG and biological age as separate covariates. Associations were stronger in younger and non frail participants in exploratory subgroup analyses. Conclusions: Metabolic dysfunction and biological aging represent complementary dimensions of CMM susceptibility and progression. TyG BA composites provide a parsimonious summary of combined metabolic-aging burden and improve risk discrimination beyond conventional clinical factors, but should not be interpreted as superior to models retaining TyG and biological age separately. These findings support the potential utility of a metabolic aging framework for risk stratification and warrant external validation, particularly for its application in earlier stages of cardiometabolic disease development. Keywords: cardiometabolic multimorbidity; TyG index; biological age; metabolic aging composite; risk stratification; prospective cohort study

Brook trout (Salvelinus fontinalis) exhibit strain-level variation in growth performance, environmental tolerance, and survival, yet the biochemical mechanisms underlying these differences remain poorly understood. We developed and applied a ratiometric biochemical framework integrating the pentose-phosphate pathway (PPP) and glutathione metabolism to characterize strain-specific hepatic metabolic organization in brook trout. Five strains reared under standardized conditions differed significantly in hepatic soluble protein density, glutathione pool size, total NADP(H) concentration, and activities of glucose-6-phosphate dehydrogenase (G6PDH), glutathione reductase (GR), and transketolase (TKT). These differences were not uniformly coordinated across pathways, demonstrating that metabolic phenotype cannot be inferred from individual biomarkers alone. Derived ratios describing oxidative-to-non-oxidative PPP capacity (G6PDH/TKT) and glutathione buffering relative to recycling capacity ((GSH+GSSG)/GR) resolved distinct patterns of metabolic allocation among strains. Despite shared ancestry, the Temiscamie (TEM) strain and its domestic x TEM hybrid (TXD) exhibited markedly divergent metabolic phenotypes, demonstrating that closely related strains can differ substantially in hepatic metabolic organization. Together, these findings identify relative allocation among interconnected metabolic pathways as an axis of physiologic diversity and establish a ratiometric approach for comparing metabolic organization across populations and species. Graphical abstractHepatic metabolic phenotypes of brook trout strains were characterized by integrating pentose phosphate pathway enzyme capacities, glutathione metabolism, NADP(H) availability, and soluble protein into a ratiometric framework. Ratios distinguish investment in oxidative versus non-oxidative PPP capacity (G6PDH/TKT), antioxidant buffering versus glutathione recycling capacity (total glutathione/GR), and hepatic protein density (soluble protein/liver mass), revealing distinct metabolic organization among strains. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/743818v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@1694676org.highwire.dtl.DTLVardef@90f2d4org.highwire.dtl.DTLVardef@365327org.highwire.dtl.DTLVardef@8d56ca_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIA ratiometric framework was developed to characterize hepatic metabolic organization in brook trout C_LIO_LIGlutathione buffering and recycling capacity distinguish alternative redox phenotypes C_LIO_LIInvestment in oxidative and non-oxidative PPP capacity varies independently among strains C_LIO_LIG6PDH/TKT and total glutathione (GSH+GSSG)/GR reveal distinct metabolic phenotypes C_LIO_LIRatiometric indices provide a framework for interpreting redox metabolism and carbon allocation C_LI