Search Results (32,508)

Background/Objectives: The emergence of drug-resistant Plasmodium falciparum highlights the need for new antiplasmodial compounds with distinct mechanisms of action. Microbial secondary metabolites, particularly from Streptomyces species, remain important sources of bioactive molecules. This study aimed to evaluate antiplasmodial metabolites associated with a Mongolian Streptomyces isolate. Methods: Streptomyces sp. strain D10 was isolated from Mongolian soil samples and extracted with ethyl acetate. Bioassay-guided fractionation was performed, followed by LC–HRMS analysis and GNPS-based spectral dereplication. Antiplasmodial activity was evaluated against P. falciparum 3D7, K1, and Dd2 strains using a SYBR Green I assay. Cytotoxicity was assessed in HSF cells. Stage-specific susceptibility assays were conducted using synchronized 3D7 parasites. Comparative docking analyses against β-hematin and the chloroquine resistance transporter (PfCRT), together with target prediction and molecular docking analyses, were performed to explore potential mechanisms. In vivo efficacy was evaluated using a Plasmodium yoelii 17XNL mouse model. Results: Fractionation yielded an active fraction (C2), and LC–HRMS and GNPS-based dereplication suggested a bile acid-like metabolite, with ursodeoxycholic acid (UDCA) returned as a putative spectral library candidate associated with fraction C2. Fraction C2 and UDCA showed comparable antiplasmodial activity against P. falciparum 3D7 (IC₅₀ = 6.55 ± 3.00 and 4.68 ± 0. 65 µg/mL, respectively) without detectable cytotoxicity up to 200 µg/mL. Activity was retained against multidrug-resistant K1 and Dd2 strains. Stage-specific assays demonstrated inhibitory activity across ring, trophozoite, and schizont stages without significant stage-dependent differences. Comparative docking analyses suggested interaction profiles distinct from chloroquine in β-hematin and PfCRT models. Additional docking analyses identified PfGluPho, PfMAPK, and PfPFT-β as potential targets. In vivo, UDCA reduced parasitemia in a dose-dependent manner without significant toxicity. Conclusions: UDCA exhibited moderate antiplasmodial activity across in vitro, in silico, and in vivo evaluations with a favorable selectivity profile, supporting further investigation of bile acid-like metabolites as potential antimalarial scaffolds. Full article

Endogenous gene tagging using CRISPR has changed the understanding of the role played by different proteins due to the ability to track and study proteins in their natural state. With CRISPR-based gene tagging, it is possible to insert fluorescent, luminescent, epitope, affinity, and proximity labels into the target protein at its endogenous genomic location without affecting its physiological expression and dynamics. Here, we discuss the DNA-repair mechanisms employed in endogenous gene tagging, including homology-dependent repair, NHEJ-based integration, and alternative approaches that can be used with challenging cell types. Key aspects of efficient CRISPR tagging experiments are also described. Additionally, we review recent advances in the increasing array of protein tag technologies, including fluorescent proteins, split-reporter technologies, NanoLuc/HiBiT, peptide epitopes, and proximity biotinylation enzymes. Lastly, we review the scalability of endogenous tagging approaches using multiplex editing, atlas-scale proteome tagging, iPSC-based disease modeling, and drug discovery platforms for assessing target engagement, protein degradation, phenotype screening, and mechanism of action of compounds. Although difficult in primary and pluripotent cells, new methods based on avoiding double-strand breaks, such as prime editing, PASTE, and CRISPR associated transposases, will drive the future expansion of endogenous tagging approaches. Such developments firmly set up CRISPR gene tagging as a fundamental technology in quantitative cell biology and translational pharmacology. Full article

Neurodegenerative disorders, including Parkinson’s and Alzheimer’s diseases, are hallmarked by the progressive degeneration of neuronal networks. Given the lack of disease-modifying cures, current therapies are limited to symptomatic relief. Here, we investigated the neurotrophic potential of the skin secretion (SS) from Rhinella schneideri, its polar fraction (PF) and nonpolar (NPF) fraction, and respective subfractions on the morphology of neuron-like cells. Following initial H₂O-CH₂CL₂ partitioning, PF and NPF subfractions were isolated via RP-HPLC. Chemical characterization using LC-MS-IT-TOF identified eight distinct molecules, notably bufotenine and marinobufagin. Cytotoxicity screening established safe working concentrations (100–250 ng/mL for SS/PF; 250–500 ng/mL for NPF and subfractions) for downstream morphological evaluations using High Content Screening (HCS). The subfraction polar 5 (SfP5) elicited a robust neurotrophic response, significantly enhancing all assessed morphometric parameters: total neurite outgrowth (+72%), branching points (+120%), maximum process length (+60%), and total number of processes (+35%). Our data show that Rhinella schneideri SS contains molecules that improve in vitro neuronal networks, serving as a promising source for preliminary screening of neuroprotective effects. Full article

Background: Type 2 diabetes mellitus (T2DM) is a global health challenge characterized by chronic hyperglycemia and oxidative stress. Pithecellobium dulce root has long been recognized for its antidiabetic potential; however, its specific bioactive constituents and mechanisms of action remain poorly defined. This study aimed to evaluate the antidiabetic and antioxidant properties of extracts and isolated molecules from P. dulce root bark. Methods: The DCM/MeOH crude extract of P. dulce root bark was fractionated with n-hexane (PDEH) and ethyl acetate (PDAE), followed by chromatographic purification and spectroscopic characterization, yielding seventeen compounds (1–17). The antioxidant activity (DPPH, ABTS, FRAP) and antidiabetic potential of PDEH, PDAE, and 1–17 were assessed in vitro using yeast-derived enzymes and in silico (targeting human α-glucosidase [PDB: 2QLY] and human α-amylase [PDB: 4GQR]). The in vitro α-glucosidase experiments used saccharomyces cerevisiae enzyme, which varies from the human target. Therefore, these results should be taken as preliminary screening data that needs confirmation with human enzymes. Results: Compound 1 was identified as new, while 2 was isolated for the first time from a natural source. The cell-free chemical tests DPPH, ABTS, and FRAP measured antioxidant capability. These tests quantify radical-scavenging and electron-transfer capabilities in vitro and are preliminary chemical screening methods. They do not directly represent biological antioxidant activity in cells or organisms. PDEH demonstrated strong radical scavenging against DPPH (IC₅₀ = 15.30 μg/mL) and ABTS (IC₅₀ = 12.80 μg/mL), while pristriol (16) showed ferric reducing power (EC₅₀ = 4200 μM FeSO₄/g). Enzyme inhibition assays demonstrated activity against α-amylase (IC₅₀ 53.88–112.24 µg/mL; acarbose IC₅₀ = 91.20 µg/mL) and α-glucosidase (IC₅₀ 18.38–136.88 µg/mL; acarbose IC₅₀ = 11.31 µg/mL). Compounds 15, 1, and 2 showed superior activity compared to acarbose for α-amylase, with effect sizes (Cohen’s d) of 2.15, 0.94, and 0.82, respectively, and IC₅₀ values of 53.88, 88.15, and 92.62 µg/mL; for α-glucosidase, IC₅₀ values were 18.38, 39.25, and 36.40 µg/mL, respectively. Docking studies supported these findings, revealing binding energies of −9.08, −8.34, and −7.22 kcal/mol for compounds 1, 2, and 15 with α-amylase, and −10.35 and −9.79 kcal/mol for compounds 1 and 2 with α-glucosidase. ADME profiling further identified 1 and 2 as promising lead candidates for dual-enzyme inhibition. Conclusions: P. dulce root bark represents a potent source of bioactive molecules with both antioxidant and dual-enzyme-inhibitory properties. These findings validate its traditional use and highlight its potential in the development of multitarget therapies for T2DM management. Full article

Citrus fruits are widely cultivated all over the world. Due to climatic conditions, citrus fruits are frequently exposed to periodic low temperatures, which poses a serious threat to their yield and quality. Cold not only restricts plant growth and deteriorates fruit quality but also leads to fruit abscission and tree mortality, posing severe constraints on large-scale citrus production. The TIFY family gene plays crucial roles in plant development and stress adaptation. However, the genome-wide identification and functional analysis of TIFY genes in cold stress adaptation of citrus plants remain largely unexplored. Here, we performed a systematic genome-wide analysis of the TIFY family in sweet orange (Citrus sinensis (L.) Osbeck) and identified 14 CsTIFY members. We conducted a comprehensive study on the protein characteristics, phylogenetic relationships, gene structure, chromosome distribution, promoter cis-acting elements, and subcellular localization of these genes. Phylogenetic analysis classified the CsTIFYs into ZML (ZML1–ZML4), JAZ (JAZ1–JAZ7), PPD (JAZ8, JAZ9), and TIFY (TIFY1) subfamilies, and they are distributed on seven chromosomes. Collinearity analysis revealed that segmental duplication is the primary driver for CsTIFY family expansion. Expression profiling under cold stress identified JAZ1, JAZ2, and JAZ3 as the most cold-inducible members. All three CsTIFY proteins are targeted to the nucleus, as confirmed by subcellular localization analysis. Overexpression of JAZ1, JAZ2, or JAZ3 in citrus calli significantly enhanced cold sensibility. Collectively, this study elucidates the gene function of CsTIFYs under cold stress and provides new insight for molecular breeding of cold-tolerant citrus varieties. Full article

Biokinetic complexities (plastic sorption, protein binding, and cellular accumulation) may cause large discrepancies between nominal and biologically effective concentrations of test compounds assessed by new approach methods (NAMs). This case study was performed to explore a generally applicable workflow that addresses biokinetic complexities in the context of NAM-based hazard testing for next-generation risk assessment (NGRA). The pesticide tebufenpyrad (TEBU) is a challenging test compound, as it (i) is hydrophobic, (ii) has an intracellular target (mitochondrial respiration), and (iii) is acting at low concentrations (susceptible to biokinetic complexities). In the newly established NeuriTox-M neurotoxicity assay, based on human dopaminergic (LUHMES) neuron cultures, TEBU showed toxic effects at 20 nM. Mass spectrometric analyses of various experimental setups showed that a large fraction (75% to >90%) of TEBU was adsorbed to plastic. This effect was strongly attenuated by albumin in the medium. Cells, cultured on plastic, were considered unsuitable to assess cellular uptake. Therefore, alternatives were explored: when cells were used as suspension cultures (3% v/v) in albumin-containing medium, analysis worked best. Under such conditions, the concentration ratio (cells/medium) of TEBU was around 10. Data from an in vitro distribution (VIVD) model were in good agreement with the measurements. VIVD predicted the unbound medium TEBU concentration (C_u) to be 2–3 orders of magnitude below the nominal concentration and the total cellular concentration to be 10–100-fold above. Standard cell culture assays showed that the medium albumin content indeed altered the TEBU toxicity threshold. More such studies are needed to embed biokinetics information into NGRA. Full article

LRRK1 is essential for osteoclast-mediated bone resorption, and loss of LRRK1 function causes osteopetrosis in mice and humans. However, the mechanisms by which LRRK1 regulates osteoclast activity remain incompletely defined. We previously identified that phosphorylation of OSTM1 at threonine 328 and serine 329 was compromised in LRRK1-deficient osteoclasts. To test the role for OSTM1 phosphorylation in LRRK1 regulation of osteoclast functions, we expressed a phosphomimetic OSTM1 variant in LRRK1-null osteoclasts. Overexpression of phosphomimetic, but not a dephosphomimetic variant, partially restored resorptive activity in LRRK1-deficient osteoclasts in vitro. To test OSTM1’s role in rescuing defective bone resorption in Lrrk1-null mice, we generated Ostm1-T328E/S329D knock-in (KI) mice and crossed them onto the Lrrk1-deficient background. Ostm1-T328E/S329D KI mice displayed normal skeletal development and bone remodeling. When crossed to the Lrrk1-deficient background, OSTM1-T328E/S329D expression increased osteoclast resorptive activity and bone formation and partially improved trabecular architecture, although bone volume remained unchanged. These findings demonstrate that OSTM1 phosphorylation contributes to LRRK1-dependent regulation of osteoclast function and identify the LRRK1–OSTM1 pathway as a mechanistic node controlling bone resorption. Our work provides new insight into the molecular basis of LRRK1-mediated osteoclast function and highlights OSTM1 phosphorylation as a potential therapeutic target for metabolic bone diseases. Full article

Prostate cancer is the most common cancer diagnosed in men and the incidence is rising globally. Disease-related mortality however remains comparatively low. There is now irrefutable evidence that many men do not need treatment if diagnosed with early cancer and can instead be safely managed conservatively. Active surveillance is therefore now an increasingly popular management option for these men. A minority of men on surveillance however will experience disease progression to a point where radical treatment is necessary. It is therefore logical to consider interventions that might slow down or abrogate this natural history. This is particularly important for subgroups of men with early cancer who are at a higher risk of progression and where the risk–benefit of therapeutic intervention is much more favourable. In this narrative review we explore the literature on known molecular and genetic events in prostate cancer which may drive progression. Our principal focus was to consider mechanisms that could be realistically targeted by therapeutics. We further consider key attributes that early cancer therapeutic trials should incorporate in their design. These include risk-stratified patient selection, bespoke dosing schedules and the importance of unambiguous, clinically meaningful endpoints in this new trial space. Full article

Intestinal fungal overgrowth (IFO) is an increasingly recognized yet underexplored component of gut dysbiosis with potential implications for gastrointestinal and systemic disease. While bacterial microbiota have historically garnered research attention, recent advances in sequencing technologies have highlighted the importance of the gut mycobiome in maintaining intestinal homeostasis. Disruption of fungal–bacterial balance, particularly involving Candida albicans, C. tropicalis, and C. glabrata, may contribute to symptom generation through immune activation, epithelial barrier dysfunction, biofilm formation, and the production of toxic metabolites such as acetaldehyde and candidalysin. Emerging clinical evidence suggests that IFO is associated with persistent gastrointestinal symptoms, including bloating, abdominal discomfort, and altered bowel habits, particularly in patients who do not respond to conventional therapies targeting bacterial overgrowth. Furthermore, fungal dysbiosis involving Malassezia restricta and Saccharomyces cerevisiae has been associated with inflammatory bowel disease, metabolic disorders, and systemic immune dysregulation; however, the nature and directionality of these relationships remain incompletely understood. Despite increasing recognition, the diagnosis of IFO remains challenging due to a lack of standardized criteria and validated non-invasive tools. Therapeutic strategies, including antifungal agents such as fluconazole and nystatin, as well as microbiome-targeted interventions, show promise but require further validation. This review provides a comprehensive synthesis of current evidence regarding the epidemiology, pathophysiology, clinical manifestations, diagnostic challenges, and therapeutic implications of IFO, with particular emphasis on species-specific mechanisms. Recognition of the intestinal mycobiome as a potentially important component of gut health may provide new perspectives for understanding gastrointestinal disorders and inform future precision medicine approaches. Full article

In modern radar and electronic countermeasure systems, frequency-agile (FA) signal generators with low phase noise are of vital importance. The optoelectronic oscillator (OEO) is restricted by the periodic boundary condition (PBC), despite its superior performance in phase noise and frequency tunability. This paper proposes a new FA optoelectronic hybrid oscillator scheme, which employs a reconfigurable aperiodic FA filter and a dynamic frequency compensation module to collaboratively break the PBC limitation. It achieves fast switching and fine-grained frequency hopping at the 100 kHz level while maintaining low phase noise. Theoretical and experimental verification show that the system can generate arbitrary FA radio frequency (RF) signals from 1.95 GHz to 2.05 GHz with a tuning range of 10³ times the free spectral range (FSR), and the phase noise reaches −120 dBc/Hz at 10 kHz offset. This study provides a novel technical route for generating narrow-step frequency-agile signals and effectively improves target detection accuracy and anti-jamming performance in electronic warfare applications. Full article

Melanoma incidence rates have also been steadily increasing, emphasizing the need for improved prognostic and diagnostic tools with the goal of enhancing patients’ outcomes. Biomarkers in melanoma have emerged as an important component of melanoma management, offering insight into disease progression, tumor biology, and the potential for judging treatment responses. Traditionally, blood and immunohistochemical markers such as lactate dehydrogenase (LDH), S100 calcium-binding protein (S100B), human melanoma black-45 (HMB-45), and SRY-box transcription factor 10 (SOX10) have been widely used in melanoma diagnosis, staging, and monitoring. However, their clinical use has been limited because of their low specificity, especially in patients with early-stage disease. This has led to the development of molecular and genetic biomarkers, including BRAF, NRAS, and KIT mutations, which improved patients’ risk stratification and enabled targeted therapies, and gene expression signature assays such as DecisionDx (Castle Biosciences) and SkylineDx (Merlin) that are already used in clinics to help with surgical decisions and to assess patients’ prognosis. Other circulating biomarkers, including microRNAs, circulating tumor DNA and circulating tumor cells, have been developed to provide minimally invasive approaches to monitor tumor evolution and detect recurrence. However, none of these new approaches are used in clinics due to their low specificity and/or sensitivity. Additionally, nomograms or predictive models have been created using biomarkers and clinicopathologic data to assess patients’ outcomes and survival. While significant progress has been made, the integration of melanoma biomarkers into routine clinical practice remains limited. This review summarizes current advancements in melanoma biomarkers, including traditional serum and immunohistochemical markers, as well as developments in molecular, genetic, circulating, and predictive biomarker approaches. Full article

Zero-shot remote sensing is attractive for scene classification because new regions, sensors, and label taxonomies often appear before sufficient annotated data are available for supervised adaptation. We present OATS-RS, an inference-centric framework that keeps a remote sensing vision–language model (VLM) backbone frozen and improves zero-shot decisions through ontology-aware prompt construction, hierarchical and contrastive scoring, adaptive multi-view aggregation, unlabeled transductive refinement, ambiguity-aware local re-ranking, and selective prediction. The method targets the common remote sensing regime in which neighboring classes such as annual crop, permanent crop, forest, pasture, herbaceous vegetation, river, and sea or lake overlap strongly in red–green–blue (RGB) appearance, meaning that they require more than a single class-name prompt. On the supplied final EuroSAT RGB evaluation with a GeoRSCLIP Contrastive Language–Image Pre-training (CLIP)-family Vision Transformer Base with 32 × 32-pixel patches (ViT-B-32) backbone, the complete pipeline obtains top-1 accuracy of 0.522, balanced accuracy of 0.522, macro-averaged F1 score (macro-F1) of 0.535, and top-3 accuracy of 0.887. The strongest classes are industrial area, residential area, river, highway, and pasture, whereas the weakest classes remain herbaceous vegetation and several fine-grained vegetation categories. Selective prediction increases accepted-example accuracy to 0.538 at 0.934 coverage, but the expected calibration error (ECE) remains high at 0.384. These results support a qualified conclusion: ontology-guided zero-shot inference can already recover useful semantic shortlists for structured remote-sensing scenes, but fine-grained natural-class disambiguation, calibrated confidence, multi-dataset transfer, component-level ablations, and measured runtime remain essential before dependable deployment claims can be made. Full article

Background: Hexavalent chromium (Cr(VI)) is a widespread environmental toxic heavy metal with strong oxidative properties; however, its immunotoxicity and metabolic mechanisms in rabbit spleen remain largely unclear. Methods: In this study, New Zealand rabbits were exposed to 0, 12.5, 25, and 50 mg/L Cr(VI) (as potassium dichromate, K₂Cr₂O₇) via drinking water for four weeks to investigate splenic damage and the underlying molecular pathways. Spleen pathological injury was evaluated by hematoxylin and eosin (H&E) staining, and the distribution of T cells, B cells, and macrophages was assessed by immunohistochemistry. Antioxidant enzyme activities and antioxidant substance levels were determined using ELISA, and the relative mRNA expression of immune factor genes, antioxidant-related genes, and ferroptosis-related genes was quantified by quantitative real-time PCR (qRT-PCR). In addition, the distribution of iron in splenic tissue was detected by enhanced Prussian blue staining. Results: Our results demonstrate that high-dose Cr(VI) significantly inhibited body weight gain, induced lymphocyte atrophy, vacuolization, and widening of intercellular spaces in the splenic white pulp. Furthermore, Cr(VI) reduced T and B lymphocyte populations, promoted macrophage infiltration and inflammatory cytokine gene expression in a concentration-dependent manner, impaired total antioxidant capacity, and led to a decrease in glutathione (GSH) levels in the spleen. Additionally, Cr(VI) exposure increased iron accumulation, activated the ACSL4–NOX lipid peroxidation cascade, and downregulated GPX4 expression, ultimately triggering ferroptosis. Conclusions: These findings reveal that Cr(VI) causes splenic immune injury by disrupting oxidative homeostasis and inducing ferroptosis, providing novel insights for evaluating immunotoxicity and identifying metabolic targets under Cr(VI) pollution. Full article

The Late Triassic Bolila Formation in the central Qiangtang Basin is a typical carbonate buildup deposited during a regional transgression in the eastern Tethyan realm. Understanding its sedimentary evolution and reservoir-forming mechanisms is crucial for hydrocarbon exploration. This study integrates petrology, detrital zircon U-Pb geochronology, carbon-oxygen isotopes, and reservoir property analysis of the Quemudongda section. The results show: (1) detrital zircon dating provides a maximum depositional age of 225.7–235.7 Ma (Carnian–Norian), correcting the previous Jurassic misassignment on the 1:250,000 geological map. Carbon-oxygen isotopes (average δ¹³C = +3.2‰, δ¹⁸O = −11.1‰) are consistent with the global Carnian–Norian positive δ¹³C excursion. (2) The section reveals a platform-margin reef (hexactinellid and calcareous sponges) and slump breccia (seven layers) association, representing a steep-rimmed carbonate platform margin. The sedimentary evolution comprises three stages: reef initiation, reef flourishing with frequent slumping, and reef decline with dolomitization. (3) Reservoirs are mainly breccia and reef dolostones, with intergranular, intercrystalline, and fracture-related pores. Porosity averages 2.8% (0.8%–7.2%), permeability averages 0.35 mD (0.001–8.5 mD), defining a low-porosity, ultra-low-permeability fracture-pore reservoir. Breccia dolostone has better properties (porosity 3.71%, permeability 2.412 mD). (4) Reservoir formation is controlled by sedimentation (platform-margin facies), diagenesis (dolomitization generates pores, but high-temperature recrystallization causes densification), and tectonics (microfractures enhance permeability). High-quality reservoirs occur where breccia dolostone and fractures overlap. (5) The Bolila reef-shoal complex and the overlying Bagong Formation source rocks form a “lower reservoir—upper source” assemblage, representing a new exploration target in the Tuonamu area. The breccia dolostone–fracture overlap zone is the core “sweet spot”. Full article

In practical remote sensing object detection tasks, the application of deep learning approaches often takes the form of incremental learning: when the application includes new target types that were not encountered during training, a pre-trained model must acquire new knowledge without suffering catastrophic forgetting. Among the various techniques proposed, knowledge distillation (KD)-based regularization has proven to be one of the most effective methods. Current KD-based approaches primarily focus on addressing inter-task confusion and optimizing feature selection during distillation processes. In this paper, we propose a dual-branch detector-independent learning framework and a multi-granularity dynamic selection strategy. The former decouples detection tasks for old and new classes to mitigate inter-class confusion, while the latter is a novel, exquisitely designed distillation mechanism that ensures precise transfer of critical old-class information. Moreover, we apply a DIST loss that aligns both inter-class and intra-class relations, further enhancing the fidelity of old-class knowledge transfer. Experiments on the DIOR and DOTA datasets demonstrate that our method significantly outperforms state-of-the-art incremental-learning approaches for remote-sensing object detection and exhibits good robustness under different remote-sensing scenarios. Full article