Search Results (140)

Dietary interventions using probiotics actively regulate metabolism in obesity and type 2 diabetes. This study aimed to characterize two novel co-isolated strains, P. pentosaceus BGI-N8 and P. acidilactici BGI-N9, using an integrated genome–phenotype approach. Whole-genome sequencing established their preliminary safety and functional genotypes, followed by in vitro assays measuring gastrointestinal tolerance, adhesion, and metabolic enzyme activity. Genomic analysis revealed that both strains achieved genome-based safety levels, and no high-confidence transferable AMR determinants and canonical virulence factors were identified. Functional annotation showed that BGI-N8 and BGI-N9 contain essential genes for gastrointestinal adaptation, including F0F1-ATPase, the dltA-D operon, and the opp transport system. Phenotypically, BGI-N9 exhibited superior acid resistance (79.3% survival at pH 2.0), while both strains showed robust auto-aggregation (>70%) and high adhesion to HT-29 cells (ranged from 5.4 to 5.9 adherent bacteria per cell). Furthermore, the strains displayed inhibitory activity against selected indicator pathogens (88.6–97.6% inhibition). Notably, BGI-N8 and BGI-N9 showed comparable α-glucosidase inhibitory activities, with inhibition rates of 44.53% and 39.94%, respectively, Both strains also exhibited comparable cholesterol-removal capacities under the tested conditions, with removal rates of 68.76% and 74.49%. Overall, these genomic and phenotypic results supported the potentials of BGI-N8 and BGI-N9 as candidate probiotic strains with distinct complementary strengths in glycolipid regulation, providing a theoretical basis for their synergistic application. Further mechanistic, safety, and in vivo studies are required to validate their metabolic-health-related relevance. Full article

Magnesium is an essential divalent cation required for adenosine triphosphate (ATP)-dependent reactions, nucleic acid metabolism, and ribosomal stability. Bacteria depend on specialized transport systems to maintain intracellular Mg²⁺ homeostasis as it cannot freely cross the phospholipid bilayer. During infection, host nutritional immunity restricts metal availability, and magnesium limitation within the phagosome compromises bacterial metabolism and stability. This review summarizes the major bacterial magnesium transport systems and their roles in survival and pathogenicity, with an emphasis on Salmonella and extension to clinically relevant ESKAPE pathogens. We focus on the PhoPQ-regulated MgtA, MgtB, and MgtC system, in which low magnesium, acidic pH, and other host-derived signals activate PhoPQ to induce mgt gene expression. MgtA and MgtB act as high-affinity P-type ATPases, whereas MgtC promotes bacterial survival within the intramacrophage environment by inhibiting bacterial F-type ATP synthase through specific interactions with subunit a. We also discuss CorA as a conserved channel for basal Mg²⁺ uptake and MgtE as a Mg²⁺-selective channel whose gating responds to intracellular Mg²⁺ and ATP. Finally, we consider the conservation and variation in these systems across pathogenic bacteria and their potential as therapeutic targets for antimicrobial development. Full article

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a major cause of morbidity and mortality worldwide, particularly due to the emergence of drug-resistant strains. Membrane-active antimicrobial peptides (AMPs) represent attractive therapeutic candidates because they target bacterial envelope integrity and disrupt essential cellular processes. We evaluated two rationally designed LL-37-derived peptides: a truncated C-terminally amidated analog (LL37-1) and a modified variant incorporating N-terminal acetylation and a single D-amino acid substitution (D-LL37). Dose–response analysis demonstrated that D-LL37 exhibited greater antimycobacterial potency, with lower inhibitory concentrations of 90% (IC₉₀) and 50% (IC₅₀) values (18.40 ± 0.39 μM and 10.11 ± 0.60 μM, respectively) compared with LL37-1 (25.44 ± 0.36 μM and 15.45 ± 1.40 μM). Fluorescence-based permeability assays revealed partial membrane disruption (36% and 44% at IC₉₀ for LL37-1 and D-LL37, respectively), which was supported by ultrastructural alterations observed by scanning electron microscopy, including bacillary shortening, rough surface formation, cell clusters, and the presence of cellular debris, all of which are consistent with membrane damage. RT-qPCR analysis demonstrated significant upregulation of the P-type ATPase genes ctpF, ctpA, and ctpH following D-LL37 exposure. Collectively, these findings indicate that optimized LL-37-derived peptides exert antitubercular activity associated with envelope perturbation and coordinated activation of ion transport-related stress responses. Full article

Cheese ripening is slow and costly, driving interest in accelerating maturation. This study aimed to isolate a safe, efficient adjunct starter from traditional Sichuan yak yoghurt, a niche rich in stress-adapted lactic acid bacteria. From 295 isolates, 15 strains tolerant to high salt, low pH, and low temperature were selected. Using acidification, autolysis, proteolysis, and peptidase activity as indices, principal component analysis identified Limosilactobacillus fermentum 270 as the best candidate. Phenotypic assays showed no haemolysis, gelatin liquefaction, indole production, or amino acid decarboxylase activity. Whole-genome sequencing confirmed species identity and revealed 52 protease/peptidase genes, complete pathways for diacetyl/acetoin biosynthesis and branched-chain amino acid conversion, and no functional biogenic amine synthesis genes. Stress-related genes (F-ATPase, glycine-betaine transport, cold-shock proteins) support cheese adaptability. Antibiotic resistance gene homologs were mainly chromosomal and unlinked to mobile genetic elements; a functional CRISPR-Cas system lowers horizontal transfer risk. The strain was developed as a freeze-dried direct-vat starter (97.3% viability). Orthogonal optimisation of yak Gouda cheese-making defined best conditions: 0.018% adjunct, 45 min acidification, pH 5.8, and 30% curd washing. L. fermentum 270 thus combines proteolytic, flavour-enhancing, genetic safety, and processing traits, offering a promising adjunct for accelerated cheese ripening. Full article

Background/Objectives: ATPase family AAA domain-containing protein 2 (ATAD2) is an oncogenic chromatin regulator that amplifies E2F/MYC transcriptional programs, yet direct modulators remain scarce. Arecoline (ARE), the primary alkaloid of the areca nut, is a known carcinogen but paradoxically exhibits context-dependent anti-proliferative activities. In this study, we resolve this paradox by defining ARE’s anti-cancer mechanism. Methods: Breast cancer cell proliferation and colony formation assays were performed to evaluate the anti-proliferative effects of ARE. Cell-cycle distribution was analyzed to determine phase-specific effects. Transcriptomic profiling was conducted to identify affected gene networks. An unbiased Cellular Thermal Shift Assay–Mass Spectrometry (CETSA-MS) screening was used to identify direct protein targets, followed by CETSA–Western blotting for validation. Finally, in silico structure-based design was applied to generate novel derivatives with improved predicted properties. Results: ARE suppressed breast cancer cell proliferation and colony formation by inducing G1/S phase arrest. Transcriptomic analysis revealed that this phenotype was driven by profound suppression of the E2F/Cell Cycle gene network. CETSA-MS identified ATAD2 through multi-omics convergence, as the 67 direct targets were collectively most significantly enriched in the E2F pathway. CETSA–Western blotting confirmed that ARE binds and thermally stabilizes ATAD2. Mechanistically, ARE engagement of ATAD2 led to downregulation of key downstream proteins, including MYC and Cyclin D1, directly linking target modulation to G1/S arrest. Structure-based design further yielded novel derivatives with predicted enhanced ATAD2 binding and substantially reduced toxicity. Conclusions: Together, these findings uncover ATAD2 as a druggable target of ARE, establish proof-of-concept for repurposing this scaffold, and provide a rational framework for developing safer ATAD2-targeted therapies. Full article

Excessive post-acidification remains a major quality concern in yogurt production, yet the strain-specific mechanisms in Streptococcus thermophilus starter cultures are unclear. This study compared the post-acidification capacity of FS (strong) and FW (weak) strains through integrated physiological and molecular analyses to elucidate the dominant role of F_oF₁-ATPase–mediated proton homeostasis during storage. Although both strains exhibited similar acidification and lactose consumption during fermentation, FS accumulated more lactic acid during storage (6.89 vs. 6.49 g/L) and showed a smaller decrease in intracellular pH (ΔpHi 0.08 vs. 0.26), indicating superior proton homeostasis under acid–cold stress. Physiological assays revealed that FS showed higher F_oF₁-ATPase activity (1.17 μmol Pi/min/mg protein) and ATP levels (0.39 μmol/mg protein) at the storage endpoint. FS also maintained a membrane with a lower UFA/SFA ratio of 1.90, suggesting increased rigidity. Transcriptomics further showed that FS reinforced the F_oF₁-ATPase efflux pathway, aided by auxiliary neutralization and membrane-stress pathways. FS suppressed energy-costly biosynthesis and transport, forming a more integrated regulatory program than FW to sustain proton homeostasis. Notably, CcpA was upregulated in FS and was associated with this energy-conserving transcriptional profile, which may support proton transport and contribute to improved proton stability and reduced post-acidification under acid–cold stress. These findings provide mechanistic insights into strain-specific post-acidification and offer molecular targets for starter culture selection. Full article

Plasma membrane Ca²⁺-ATPases (PMCA) are activated by calmodulin (CaM) via a C-terminal calmodulin-binding domain, CaMBD. Although specific mutations in this domain have been linked to disease, the broader impact of alternative substitutions across the interface remains unexplored. We applied an integrative in silico workflow to test six substitutions within CaMBD positions 1–18, L5R, N6I, I8T, V14E/D, and F18S, across PMCA isoforms 1–4. CaMBD sequences were aligned across isoforms, and candidates for substitutions were selected by conservation and nucleotide feasibility, prioritizing conserved or co-evolutionarily relevant sites, with substitutions possible by single-nucleotide change. PolyPhen-2 screened the impact of the substitutions on the protein functionality, the DisGeNET database was used to contextualize ATP2B genes with clinical phenotypes, and structural models plus binding free energy changes were estimated with AlphaFold3, FoldX, and MutaBind2. Effects were isoform and subregion dependent, with the strongest weakening toward the CaMBD C-terminus. V14E/D and F18S showed the largest and consistent predicted destabilization, consistent with disruption of conserved hydrophobic anchors. I8T and L5R had mixed outcomes depending on isoform, while N6I presented various scenarios with no clear effect. PolyPhen-2 classified most tested substitutions as damaging. Gene-disease evidence linked ATP2B to neurological, endocrine, and oncologic phenotypes, consistent with roles in Ca²⁺ homeostasis. Overall, CaMBD appears highly sensitive to perturbation, with distal positions 14–18 particularly vulnerable to substitutions that can destabilize CaM binding and potentially impair PMCA-mediated Ca²⁺ clearance in susceptible tissues. Full article

The 26S proteasome is the main proteolytic machinery involved in protein degradation, thereby contributing to the homeostasis and stress response of eukaryotic cells. This macromolecular complex consists of a 20S core particle assembled with one or two 19S regulatory particles. Here, we describe the Plasmodium berghei (Pb) proteasome AAA-ATPase regulatory subunit Rpt3 and demonstrate its binding to the Protein Phosphatase 1 catalytic subunit (PP1c), which is one of the major and essential parasite phosphatases. The PbRpt3 protein enhances the activity of PP1c both in vitro and in a Xenopus oocyte heterologous model. Further investigation of this model suggests that the PbRpt3-PP1c interaction may occur outside of the proteasome, and it reveals that the RVxF motifs of PbRpt3 are involved in its binding and regulatory function. Moreover, the ATP-binding capacity of PbRpt3 may also contribute to its phosphatase regulatory activity. In the parasite, reverse genetic studies suggest an essential role for PbRpt3 during erythrocytic cycle of P. berghei, and an interactome analysis confirmed that PbRpt3 belongs to the 19S regulatory particle of the proteasome and may interact with proteins previously shown to be involved in phospholipid binding. Full article

Bisphenol A (BPA) replacement chemicals are used in products like food packaging, plastic piping, and sportswear. While they can be toxic, their neurotoxicity is less understood. The aim of this study was to treat differentiated human SH-SY5Y cells with Bisphenol S (BPS) and Bisphenol F (BPF) to investigate mechanisms of toxicity. BPS reduced cell viability (>50 µM at 48 h) more than BPF (>200 µM at 48 h), with concentration- and time-dependent effects. Both induced caspase 3/7 activity at 250 µM after 48 h, though no changes were observed in levels of reactive oxygen species nor mitochondrial ATPase activity. RNA-seq analysis at 0.1 nM revealed distinct transcriptional networks: BPS altered IL15R, causing NF-kB/NFATC activation, and triggered NF-kB signaling through CD8, while BPF affected TLR9 and activated NF-kB targets through TNF. Pathway analysis showed that genes involved in neuroinflammation, protein folding, microglial function, and motor neuron regulation were disrupted, demonstrating that BPS and BPF, even at low, environmentally relevant concentrations, significantly alter gene expression in pathways linked to neuroinflammation, immune signaling, and neurodegenerative diseases. BPS primarily affected ribosomal and immune-related networks, while BPF disrupted oxidative phosphorylation and protein-folding pathways. These alterations suggest mechanisms for long-term neurological effects, highlighting the need for comprehensive evaluations of BPA alternatives. Full article

Background/Objectives: In the fight against ovarian cancer, various therapies have been employed, with a strong focus on developing novel derivatives of existing substances. Methods: In this study, we continue our research on novel xanthone derivatives in combination with mild hyperthermia, targeting ovarian cancer cell lines TOV-21G and SK-OV-3. Using qPCR arrays, we analyzed 84 cellular stress-related genes categorized into anti-oxidant and pro-oxidant enzymes, molecular chaperones, and xenobiotic metabolism including the cytochrome P450 group. Furthermore, we conducted in silico analyses to investigate the pathways of the most affected genes, gene set enrichment, and gene ontology. Results: The most significant changes were observed in SOD2, SOD3, CYP2F1, CYP1B1, and HMOX1. Additional changes related to drug toxicity and the postulated mechanism of action were also identified. Based on in silico analyses, we concluded that the primary node of hyperthermia-induced changes is HSPA1A. Heat-induced alterations predominantly revolve around misfolded proteins, monooxygenase activity, and ATPase activity. Conclusions: To summarize, the combined therapy of novel xanthone derivatives and mild hyperthermia shows promising results and warrants further investigation to fully elucidate the mechanisms of action underlying these effects. Full article

Endocytic uptake and lysosomal localization are suggested to be the key mechanisms underlying the toxicity of metal oxide nanoparticles (MONPs), with dissolution in the acidic milieu driving the response. In this study, we aimed to investigate if MONPs of varying solubility are similarly sequestered intracellularly, including in lysosomes and the role of the acidic lysosomal milieu on toxicity induced by copper oxide (CuO) nanoparticles (NPs), nickel oxide (NiO) NPs, aluminum oxide (Al₂O₃) NPs, and titanium dioxide (TiO₂) NPs of varying solubility in FE1 lung epithelial cells. Mitsui-7 multi-walled carbon nanotubes (MWCNTs) served as contrasts against particles. Enhanced darkfield hyperspectral imaging (EDF-HSI) with fluorescence microscopy was used to determine their potential association with lysosomes. The v-ATPase inhibitor Bafilomycin A1 (BaFA1) was used to assess the role of lysosomal acidification on toxicity. The results showed co-localization of all MONPs with lysosomes, with insoluble TiO₂ NPs showing the greatest co-localization. However, only acute toxicity induced by soluble CuO NPs was affected by the presence of BaFA1, showing a 14% improvement in relative survival. In addition, all MONPs were found to be associated with large actin aggregates; however, treatment with insoluble TiO₂ NPs, but not soluble CuO NPs, impaired the organization of F-actin and α-tubulin. These results indicate that MONPs are sequestered similarly intracellularly; however, the nature or magnitude of their toxicity is not similarly impacted by it. Future studies involving a broader variety of NPs are needed to fully understand the role of differential sequestration of NPs on cellular toxicity. Full article

Cardiotonic steroids (CTS), including the endogenous compound ouabain, modulate neuronal Na/K-ATPase (NKA) activity in a concentration-dependent manner, affecting neuronal survival and function. While high concentrations of ouabain are neurotoxic, endogenous levels of 0.1–1 nM exert neuroprotective effects and influence intracellular signaling. However, the effects of physiologically relevant ouabain concentrations on excitatory synaptic transmission remain unclear. In this study, we examined how 1 nM ouabain affects synaptic responses in rat hippocampal CA1 neurons. Using whole-cell patch-clamp recordings of evoked excitatory postsynaptic currents (EPSCs) and extracellular recordings of field excitatory postsynaptic potentials (fEPSPs), we found that ouabain enhances excitatory synaptic transmission, increasing EPSC amplitude and fEPSP slope by 35–50%. This effect was independent of NMDA receptor (NMDAR) activity. Ouabain reduced the magnitude of NMDAR-dependent long-term potentiation (LTP), but still augmented fEPSPs when applied after LTP induction. This implies separate additive mechanisms. These observations exhibit that ouabain, at concentrations corresponding to endogenous levels, facilitates basal excitatory synaptic transmission while partially suppressing LTP. We propose that ouabain exerts dual modulatory effects in hippocampal networks via distinct synaptic mechanisms. Full article

Fusarium head blight (FHB) is a major threat to wheat production that is caused by toxigenic species of the Fusarium graminearum complex. This study aimed to investigate the biochemical and molecular defense responses of Brazilian wheat genotypes (BRS 194, BRS Parrudo, and Frontana) with contrasting FHB susceptibilities following inoculation with F. graminearum (deoxynivalenol producer) and F. meridionale (nivalenol producer). Temporal patterns of antioxidant enzymes, defense-related enzymes, and gene expression (ABC-Transporter and Ca²⁺-ATPase) were analyzed from 12 to 96 h after inoculation. The ANOVA results revealed significant effects of genotypes, inoculation, and time after inoculation on most of the evaluated enzymatic activities. Frontana exhibited high basal activity for most enzymes, and after inoculation, the enzyme activity was higher than in other genotypes. BRS 194 presented delayed and fragmented activation patterns, particularly under DON-producing pathogen infection. According to the transcriptome results, inoculation with the NIV-producing pathogen upregulated both genes, reaching up to an 18-fold increase. BRS 194 showed an upregulated transcript pattern from the early hours after inoculation. Frontana showed increased transcript levels, reaching 12-fold, under DON-producing pathogen infection. These findings show that biochemical and molecular responses varied depending on genotype and the chemotype of the Fusarium isolate, highlighting the importance of early, coordinated defense activation in FHB resistance. Full article

The midgut of Antheraea pernyi plays a critical role in antiviral defense. However, its transcriptional complexity remains poorly understood. Here, a full-length (FL) transcriptome atlas of A. pernyi midgut was developed by integrating PacBio Iso-Seq and RNA-seq techniques. The transcriptome sequences included 1850 novel protein-coding genes, 17,736 novel alternative isoforms, 1664 novel long non-coding RNAs (lncRNAs), and 858 transcription factors (TFs). In addition, 2471 alternative splicing (AS) events and 3070 alternative polyadenylation (APA) sites were identified. Moreover, 3426 and 4796 differentially expressed genes (DEGs) and isoforms were identified after ApNPV infection, respectively, besides the differentially expressed lncRNAs (164), TFs (171), and novel isoforms of ApRelish (1) and ApSOCS2 (4). Enrichment analyses showed that KEGG pathways related to metabolism were suppressed, whereas GO terms related to DNA synthesis and replication were induced. Furthermore, the autophagy and apoptosis pathways were significantly enriched among the upregulated genes. Protein–protein interaction network (PPI) analysis revealed the coordinated downregulation of genes involved in mitochondrial ribosomes, V-type and F-type ATPases, and oxidative phosphorylation, indicating the disruption of host energy metabolism and organelle acidification. Moreover, coordinated upregulation of genes associated with cytoplasmic ribosomes was observed, suggesting that the infection by ApNPV interferes with host translational machinery. These results show that ApNPV infection reprograms energy metabolism, biosynthetic processes, and immune response in A. pernyi midgut. Our study provides a foundation for elucidating the mechanisms of A. pernyi–virus interactions, particularly how the viruses affect host defense strategies. Full article

Polarized fluorescence microscopy of “ghost” muscle fibers, containing fluorescently labeled F-actin, tropomyosin, and myosin, has provided new insights into the molecular mechanisms underlying muscle contraction. At low Ca²⁺, the troponin-induced overtwisting of the actin filament alters the configuration of myosin binding sites, preventing actin–myosin interactions. As Ca²⁺ levels rise, the actin filament undergoes untwisting, while tropomyosin becomes overtwisted, facilitating the binding of myosin to actin. In the weakly bound state, myosin heads greatly increase both the internal twist and the bending stiffness of actin filaments, accompanied by the untwisting of tropomyosin. Following phosphate (Pi) release, myosin induces the untwisting of overtwisted actin filaments, driving thin-filament sliding relative to the thick filament during force generation. Point mutations in tropomyosin significantly alter the ability of actin and tropomyosin filaments to respond to Pi release, with coordinated changes in twist and bending stiffness. These structural effects correlate with changes in actomyosin ATPase activity. Together, these findings support a model in which dynamic filament twisting is involved in the molecular mechanisms of muscle contraction together with the active working stroke in the myosin motor, and suggest that impairment of this ability may cause contractile dysfunction. Full article