Search Results (222)

Atherosclerosis is a complex vascular disorder driven by oxidative stress, inflammation, and platelet activation. Agents capable of targeting multiple atherogenic pathways may provide improved therapeutic benefits. In this study, we evaluated the anti-atherogenic effects of chrysotoxine, a bibenzyl compound isolated from Dendrobium pulchellum, using in vitro models relevant to atherogenesis. Chrysotoxine significantly suppressed hemin-induced LDL oxidation by reducing lipid peroxidation and apolipoprotein modification. In an endothelial–monocyte co-culture model, chrysotoxine markedly attenuated lipopolysaccharide-induced monocyte adhesion, indicating inhibition of endothelial inflammatory activation. Chrysotoxine also inhibited platelet aggregation induced by arachidonic acid, ADP, and collagen in a concentration-dependent manner, with the strongest effects observed against arachidonic acid–mediated responses, suggesting modulation of the thromboxane pathway. Molecular docking analyses and cyclooxygenase activity assays further indicated that chrysotoxine may interact with both COX-1 and COX-2, exhibiting inhibitory activity in the low micromolar range. Collectively, these findings demonstrate that chrysotoxine modulates multiple key processes involved in atherogenesis, including oxidative LDL modification, vascular inflammation, and platelet activation. Although further in vivo studies are required, chrysotoxine represents a promising plant-derived candidate for the development of multi-target strategies against atherosclerotic disease. Full article

Pulmonary hypertension (PH) causes morbidity and mortality in sickle cell disease (SCD). The release of heme during hemolysis triggers endothelial dysfunction and contributes to PH. Long non-coding RNAs (lncRNAs) may play a pivotal role in endothelial dysfunction and PH pathogenesis. This study assessed the regulatory role of the lncRNA–heme oxygenase-1 (HMOX1) axis in SCD-associated PH pathogenesis. Total RNAs were isolated from the lungs of 15–17-week-old sickle cell (SS) mice and littermate controls (AA) mice and subjected to lncRNA expression profiling using the Arrystar™ lncRNA array. Volcano plot filtering was used to screen for differentially expressed lncRNAs and mRNAs with statistical significance (fold change > 1.8, p < 0.05). A total of 3915 lncRNAs were upregulated and a total of 3545 lncRNAs were downregulated in the lungs of SS mice compared to AA mice. To validate differentially expressed lncRNAs, six upregulated lncRNAs and six downregulated lncRNAs were selected for quantitative PCR. MALAT1 expression was significantly upregulated in the lungs of SS mice and in hemin-treated human pulmonary artery endothelial cells (HPAECs), suggesting that hemolysis induces MALAT1. Functional studies revealed that MALAT1 depletion increased, while MALAT1 overexpression decreased, the endothelial dysfunction markers endothelin-1 (ET-1) and vascular cell adhesion molecule-1 (VCAM1), indicating a protective role of MALAT1 in maintaining endothelial homeostasis. In vivo, adenoviral MALAT1 overexpression attenuated PH, right ventricular hypertrophy (RVH), vascular remodeling, and reduced ET-1 and VCAM1 expression in SS mice. Given that HMOX1 protects endothelial cells during hemolysis, we observed that HMOX1 expression and activity were elevated in SS mouse lungs and hemin-treated HPAECs. HMOX1 knockdown enhanced ET-1 and VCAM1 expression, confirming its endothelial-protective function. Importantly, MALAT1 overexpression increased HMOX1 expression and activity, whereas MALAT1 knockdown reduced HMOX1 levels and mRNA stability. Collectively, these findings identify MALAT1 as a protective regulator that mitigates endothelial dysfunction, vascular remodeling, and PH in SCD, at least in part through the induction of HMOX1. These results suggest that SCD modulates the MALAT1–HMOX1 axis, and further characterization of MALAT1 function may provide new insights into SCD-associated endothelial dysfunction and PH pathogenesis, as well as identify novel therapeutic targets. Full article

The transcription factor NRF2 orchestrates diverse cellular homeostatic networks, but its role in angiogenesis remains poorly understood. Genetic and pharmacological modulation of NRF2 in mouse neuroendothelial cells altered the expression of several genes involved in endothelial biology. Among these, the TIE2/Tek receptor, essential for vascular development and integrity, was downregulated upon NRF2 activation, accompanied by changes in adherens and tight junction gene expression. Hemin treatment and knockdown revealed that TIE2/Tek repression is independent of the NRF2 repressor BACH1. mRNA stability and ChIP analyses indicated no post-transcriptional or direct transcriptional repression by NRF2. These findings suggest an alternative NRF2-dependent mechanism affecting TIE2/Tek levels and potentially influencing angiogenic regulation. Full article

G-quadruplex (G4) DNAzymes, guanine-rich sequences that fold into four-stranded structures and bind hemin to mimic peroxidase activity, are widely used in biosensing. Split G4 DNAzymes offer conditional activation upon target recognition, enabling high specificity and modularity. However, achieving low OFF-state leakage remains a major challenge. Here, we systematically characterized four representative G4 scaffolds, C-myc, Bcl2, PS5.M, and C-kit, under standardized ABTS/H₂O₂ conditions to assess their kinetic properties and suitability for split designs. C-myc exhibited the highest sustained activity and near-linear concentration dependence, making it ideal for quantitative sensing, while Bcl2 showed durable catalysis suited for extended read windows. C-kit produced rapid bursts with early plateaus, favoring binary outputs, and PS5.M initiated quickly but inactivated rapidly, suggesting potential application of systems requiring fast response. Split-mode analysis revealed that symmetric 2:2 partitions often retained significant activity, whereas asymmetric 3:1 splits reduced but did not eliminate leakage. Among the four G4 DNAzymes, PS5.M demonstrated the most promising OFF-state suppression. Design strategies to minimize leakage including non-classical splits, loop/flank edits, and template-assisted assembly could be used to optimize biosensor functionalities. These findings identify essential factors critical for designing robust split DNAzyme biosensors, advancing applications in diagnostics and molecular logic gates. Full article

Expansion of d(GGGGC)_n repeat in the C9ORF72 gene is causal for Amyotrophic Lateral Sclerosis (ALS) and Frontal Temporal Dementia (FTD). Proposed mechanisms include Repeat-Associated Non-AUG translation or the formation of G-quadruplexes (GQ) that disrupt translation, induce protein aggregation, sequester RNA processing factors, or alter RNA editing. Here, I show, using AlphaFold V3 (AF3) modeling, that the TAR DNA-binding protein (TDP-43) docks to a complex of GQ and hemin. TDP-43 methionines lie over hemin and likely squelch the generation of superoxide by the porphyrin-bound Fe. These TDP-43 methionines are frequently altered in ALS patients. Tau protein, a variant of which causes ALS, also binds to GQ and heme and positions methionines to detoxify peroxides. Full-length Tau, which is often considered prone to aggregation and a prion-like disease agent, can bind to an array composed of multiple GQs as a fully folded protein. In ALS and FTD, loss-of-function variants cause an uncompensated surplus of superoxide, which sparks neuronal cell death. In Alzheimer’s Disease (AD) patients, GQ and heme complexes bound by β-amyloid 42 (Aβ4) are also likely to generate superoxides. Collectively, these neuropathologies have proven difficult to treat. The current synthesis provides a framework for designing future therapeutics. Full article

Hemibagrus guttatus is a commercially valuable freshwater fish in the Pearl River Basin, renowned as the “King of Freshwater Fish.” Due to habitat degradation and overfishing, its wild population has declined sharply, leading to its listing as a National Key Protected Wild Animal of Class II in China. Artificial breeding is therefore crucial for conservation, yet progress is hindered by the lack of clear sexual dimorphism and poor understanding of its sex differentiation mechanism. In this study, we performed high-throughput RNA sequencing (RNA-seq) to compare gonadal transcriptomes of male and female H. guttatus. A total of 3245 differentially expressed genes (DEGs) were identified, including 3122 male-biased and 123 female-biased DEGs, which clustered into three distinct expression patterns. Enrichment analysis revealed that genes associated with the TGF-β (Transforming Growth Factor-beta) and GnRH (Gonadotropin-Releasing Hormone) signaling pathways were significantly enriched in the female gonads, suggesting their potential roles in gonadal differentiation. From the DEG set, we further highlighted five genes with pronounced sex-biased expression: rbm46 (RNA Binding Motif Protein 46) exhibited gonad-specific expression, whereas myc (v-myc avian myelocytomatosis viral oncogene homolog), angptl4 (Angiopoietin-Like 4), sox9 (SRY-Related HMG-Box Gene 9), and fzd2 (Frizzled Class Receptor 2) showed marked expression differences between male and female gonads. These findings provide insights into the molecular mechanisms underlying sex differentiation in H. guttatus, offer potential molecular markers for sex identification, and establish a scientific basis for germplasm conservation and the optimization of breeding techniques. Full article

Enzymatically crosslinked hydrogels are important in biomedical applications. However, conventional horseradish peroxidase (HRP)-based systems are expensive, unstable, and potentially immunogenic. Herein, we introduce hemin/albumin complexes as cost-effective and biocompatible catalysts for phenol-mediated hydrogel formation. Phenolated bovine serum albumins (BSA-LPh, -MPh, and-HPh) with different degrees of substitution were synthesized and complexed with hemin. Spectroscopic analysis demonstrated that phenol modification altered the hemin microenvironment, resulting in distinct shifts in the Soret band. Functional assays revealed that albumin complexation enhanced catalytic activity compared to hemin alone. Moderate phenol modification provided an optimal balance between catalytic efficiency and hydrogel integration, whereas excessive modification reduced the performance of the enzyme. Hydrogels containing hemin/BSA-Ph complexes exhibited controllable protein retention and high cytocompatibility (>90%) with mouse fibroblast 10T1/2 cells. These findings demonstrate that hemin/albumin complexes are promising, cost-effective, and cytocompatible alternatives to HRP systems for hydrogel-based biomedical and nonclinical applications. Full article

In this study, a sliding microfluidic biosensor integrating RPA-SDA cascaded amplification was developed for the rapid, visual detection of Shigella. A novel RPA primer targeting the specific ipaH gene was designed to include a 5′-end G-quadruplex (G4) sequence and the complementary sequence of an Nt.BstNBI endonuclease recognition site. The RPA product templates a subsequent SDA reaction, generating abundant G4 structures that form peroxidase-mimicking DNAzymes with hemin, catalyzing a TMB reaction that produces a distinct blue color for visual readout (on-chip detection at OD₃₇₀, distinct from conventional tube assays at OD₄₅₀). The core on-chip detection process was completed within 13 min (10 min for SDA and 3 min for color development), achieving a limit of detection of 3.5 × 10⁻⁴ ng/μL for Shigella genomic DNA. This timing explicitly excludes the preceding, off-chip steps of nucleic acid extraction and RPA amplification. Validation using spiked lettuce samples confirmed the platform’s high specificity and sensitivity. This work establishes a proof-of-concept for a portable screening tool, highlighting its potential for on-site food safety applications. However, further validation in diverse food matrices and under real-world field conditions is required to fully establish its practical utility. Full article

Staining-based assays are widely used for cell analysis but are invasive, alter physiology, and prevent longitudinal monitoring. Label-free, morphology-based approaches could enable real-time, non-invasive drug testing, yet detection of subtle and dynamic changes has remained difficult. We developed a deep learning framework for stain-free monitoring of leukemia cell cultures using automated bright-field microscopy in a semi-automated culture system (AICE3, LABMaiTE, Augsburg, Germany). YOLOv8 models were trained on images from K562, HL-60, and Kasumi-1 cells, using an NVIDIA DGX A100 GPU for training and tested on GPU and CPU environments for real-time performance. Comparative benchmarking with RT-DETR and interpretability analyses using Eigen-CAM and radiomics (RedTell) was performed. YOLOv8 achieved high accuracy (mAP@0.5 > 98%, precision/sensitivity > 97%), with reproducibility confirmed on an independent dataset from a second laboratory and an AICE3 setup. The model distinguished between morphologically similar leukemia lines and reliably classified untreated versus differentiated K562 cells (hemin-induced erythroid and PMA-induced megakaryocytic; >95% accuracy). Incorporation of decitabine-treated cells demonstrated applicability to drug testing, revealing treatment-specific and intermediate phenotypes. Longitudinal monitoring captured culture- and time-dependent drift, enabling separation of temporal from drug-induced changes. Radiomics highlighted interpretable features such as size, elongation, and texture, but with lower accuracy than the deep learning approach. To our knowledge, this is the first demonstration that deep learning resolves subtle, drug-induced, and time-dependent morphological changes in unstained leukemia cells in real time. This approach provides a robust, accessible framework for label-free longitudinal drug testing and establishes a foundation for future autonomous, feedback-driven platforms in precision oncology. Ultimately, this approach may also contribute to more precise and adaptive clinical decision-making, advancing the field of personalized medicine. Full article

Human–machine trust has shifted over the past three decades from trust in automation to trust in AI, while research paradigms, disciplines, and problem spaces have expanded. Centered on AI in healthcare, this narrative review offers a longitudinal synthesis that traces and compares phase-specific changes in theory and method, providing design guidance for human-AI systems at different stages of maturity. From a cross-disciplinary view, we introduce an Interdisciplinary Human-AI Trust Research (I-HATR) framework that aligns explainable AI (XAI) with human–computer interaction/human factors engineering (HCI/HFE). We distill three core categories of determinants of human-AI trust in healthcare, user characteristics, AI system attributes, and contextual factors, and summarize the main measurement families and their evolution from self-report to behavioral and psychophysiological approaches, with growing use of multimodal and dynamic evaluation. Finally, we outline key trends, opportunities, and practical challenges to support the development of human-centered, trustworthy AI in healthcare, emphasizing the need to bridge actual trustworthiness and perceived trust through shared metrics, uncertainty communication, and trust calibration. Full article

Tunnel lining voids, a common latent defect induced by the coupling effects of complex geological, environmental, and load factors, pose severe threats to operational and personnel safety. Traditional detection methods relying on Ground-Penetrating Radar (GPR) combined with manual interpretation suffer from high subjectivity, low efficiency, frequent missed or false detections, and an inability to achieve real-time monitoring. Thus, this paper proposes an intelligent identification methodology for tunnel lining voids based on an improved version of YOLOv8. Key enhancements include integrating the RepVGGBlock module, dynamic upsampling, and a spatial context-aware module to address challenges from diverse void geometries—resulting from interactions between the environment, geology, and load—and complex GPR signals caused by heterogeneous underground media and the varying electromagnetic properties of materials, which obscure void–background boundaries, as well as interference signals from detection processes. Additionally, the C2f-Faster module reduces the computational complexity (GFLOPs), parameter count, and model size, facilitating edge deployment at detection sites to achieve real-time GPR signal interpretation for tunnel linings. Experimental results on a heavy-haul railway tunnel’s lining defect dataset show 11.57% lower GFLOPs, 14.55% fewer parameters, and 13.85% smaller weight files, with average accuracies of 94.1% and 94.4% in defect recognition and segmentation, respectively, meeting requirements for the real-time online detection of tunnel linings. Notably, the proposed model is specifically tailored for void identification and cannot handle other prevalent tunnel lining defects, which restricts its application in comprehensive tunnel health monitoring scenarios where multiple defects often coexist to threaten structural safety. Full article

In some cases, the catalytic processes involve the formation of self-organized supramolecular structures due to H-bonds and other non-covalent interactions. It has been suggested that the construction of self-assembled catalytic systems is a promising strategy to mimic enzyme catalysis at the model level. As a rule, the real catalysts are not the primary catalytic complexes, but rather, those that are formed during the catalytic process. In our earlier works, we have established that the effective catalysts M(II)_xL¹_y(L¹_ox)_z(L²)_n(H₂O)_m (M = Ni, Fe, L¹ = acac⁻, L² = activating electron-donating ligand) for the selective oxidation of ethylbenzene to α-phenyl ethyl hydroperoxide are the result of the transformation of primary (Ni(Fe)L¹)_x(L²)_y complexes during the oxidation of ethylbenzene. In addition, the mechanism of the transformation to active complexes is similar to the mechanism of action of NiFeARD (NiFe-acireductone dioxygenase). Based on kinetic and spectrophotometric data, we hypothesized that the high stability of effective catalytically active complexes may be associated with the formation of stable supramolecular structures due to intermolecular hydrogen bonds and possibly other non-covalent bonds. We confirmed this assumption using AFM. In this work, using AFM, we studied the possibility of forming supramolecular structures based on iron complexes with L²-crown ethers and quaternary ammonium salts, which are catalysts for the oxidation of ethylbenzene and are models of FeARD (Fe-acireductone dioxygenase). The formation of supramolecular structures based on complexes of natural Hemin with PhOH and L-histidine or Hemin with L-tyrosine and L-histidine, which are models of heme-dependent tyrosine hydroxylase and cytochrome P450-dependent monooxygenases (AFM method), may indicate the importance of outer-sphere regulatory interactions with the participation of Tyrosine and Histidine in the mechanism of action of these enzymes. Full article

Origanum majorana L. (O. majorana) (Lamiaceae) is an aromatic Mediterranean plant widely used in food, cosmetics, and traditional medicine due to its aroma and rich content of bioactive compounds. While its leaves and flowers are commonly utilized, lignified stems are often discarded. This study compared hydroalcoholic extracts from the leaves and flowers (valuable fraction, VF) and stems (by-product, BP). Phytochemical analysis revealed qualitatively similar profiles, identifying 20 phenolic compounds, with Rosmarinic acid and Salvianolic acid B as the most and second most abundant, respectively. Antioxidant activity was evaluated in vitro using DPPH (IC₅₀ [µg/mL]: VF 30.11 ± 3.46; BP 31.72 ± 1.46), H₂O₂ (IC₅₀ [µg/mL]: VF 103.09 ± 4.97; BP 119.55 ± 10.58), and O₂^•− (IC₅₀ [µg/mL]: VF 0.71 ± 0.062; BP 0.79 ± 0.070). Both extracts (20 µg/mL) fully restored oxidative balance in hemin-stressed AC16 cardiomyocytes, without altering the expression of catalase, heme-oxygenase 1, superoxide dismutase 2, or ferritin. Anti-inflammatory activity in LPS-stimulated RAW 264.7 macrophages showed that VF (IC₅₀ 400 µg/mL) reduced ^•NO release to control levels, while BP achieved a ~60% reduction. Cytotoxicity was assessed on cancer cell lines: CaCo-2 (IC₅₀ [µg/mL]: VF 154.1 ± 6.22; BP 305.2 ± 15.94), MCF-7 (IC₅₀ [µg/mL]: VF 624.6 ± 10.27; BP 917.9 ± 9.87), and A549 (IC₅₀ [µg/mL]: VF 720.8 ± 13.66; BP 920.2 ± 16.79), with no cytotoxicity on normal fibroblasts HFF-1 (IC₅₀ > 1000 µg/mL for both extracts). Finally, both extracts slightly inhibited only CYP1A2 (IC₅₀ [µg/mL]: VF 497.45 ± 9.64; BP 719.72 ± 11.37) and CYP2D6 (IC₅₀ [µg/mL]: VF 637.15 ± 14.78, BP 588.70 ± 11.01). These results support the potential reuse of O. majorana stems as a sustainable source of bioactive compounds for nutraceutical and health-related applications. Full article

We aimed to simulate tau abnormalities—specifically hyperphosphorylation and aggregation—that are hallmarks of tauopathies, including Alzheimer’s disease, to evaluate tau-targeting therapies. To model pathological p-tau accumulation at early disease stages, we exposed mouse cortical cultures to redox-active iron from hemin (Hm), a breakdown product of hemoglobin, or challenged them with the excitatory neurotransmitter glutamate. Using the AT8 phospho-specific antibody, we demonstrate that a subtoxic concentration of Hm (3 µM) promotes pathological p-tau accumulation in a subpopulation of cultured cortical neurons and their proximal neurites. Uric acid (UA; 0.1–200 µM), the metabolic end-product of purines in humans, prevented p-tau build-up. Neither xanthine, the immediate precursor of UA, nor allantoin, its oxidized product, reproduced this effect. Live cell imaging studies revealed that UA operates by repressing iron-driven lipid peroxidation. DOT (3 µM), a brain-permeant tetracycline (TC) without antibiotic activity, mimicked UA’s anti-tau and antioxidant effects. Interestingly, both UA and DOT remained effective in preventing p-tau accumulation induced by glutamate (10 µM). To simulate tau aggregation at more advanced disease stages, we conducted a Thioflavin-T aggregation assay. Our findings revealed that UA and DOT prevented tau aggregation seeded by heparin. However, only DOT remained effective when heparin-assembled tau fibrils were used as the seeding material. In summary, our results indicate that UA-elevating agents may hold therapeutic utility for tauopathies. The non-purine compound DOT could serve as an effective alternative to UA-related therapies. Full article

Serratia plymuthica, isolated from the midgut of Aedes aegypti, displays remarkable resilience to hemin, a toxic hemoglobin byproduct generated during blood digestion. This study explores its proteomic adaptations under oxidative stress induced by 5 mM hemin, mimicking midgut conditions. Growth assays demonstrated that S. plymuthica tolerated hemin concentrations ranging from 5 µM to 1 mM, reaching the stationary phase within approximately 10 h. Colonies exhibited morphological changes—darkened peripheries and translucent halos—suggesting heme accumulation and detoxification. Label-free quantitative proteomics identified 436 proteins, among which 28 were significantly upregulated—including universal stress proteins (USPs), ABC transporters, and flavodoxin—while 54 were downregulated, including superoxide dismutase and several ribosomal proteins. Upregulated proteins were associated with antioxidant defense, heme transport, and redox regulation, whereas downregulated proteins suggested metabolic reprogramming to conserve energy under stress. Functional enrichment analysis revealed significant alterations in transmembrane transport, oxidative stress response, and central metabolism. These findings suggest that S. plymuthica contributes to redox homeostasis in the mosquito gut by mitigating reactive oxygen species (ROS) and detoxifying excess heme, supporting its role as a beneficial symbiont. The observed stress tolerance mechanisms may influence mosquito physiology and vector competence, offering novel insights into mosquito–microbiota interactions and potential microbiota-based strategies for vector control. Full article