Search Results (513)

Background: Immune checkpoint inhibitor therapy in patients with lung cancer and metastatic melanoma is associated with exacerbation of autoimmune-related diseases. The efficacy of treatment targeting the programmed cell death receptor-1 (PD-1) checkpoint relies upon a feedback loop between interferon gamma (IFN-γ) and the interleukin-12 isoform, IL-12p40. Paradoxically, both cytokines and the anti-PD-1 antibody worsen psoriasis. We previously reported an immunomodulating peptide, designated IK14004, that inhibits progression of Lewis lung cancer in mice yet uncouples IFN-γ from IL-12p40 production in human immune cells. Methods: Immune cells obtained from healthy donors were exposed to IK14004 in vitro to further characterise the signalling pathways affected by this peptide. Using C57BL/6 immunocompetent mice, the effect of IK14004 was tested in models of lung melanoma and psoriatic skin. Results: Differential effects of IK14004 on the expression of IFN-α/β, the interleukin-15 (IL-15) receptor and signal transducers and activators of transcription were consistent with immune responses relevant to both cancer surveillance and immune tolerance. Moreover, both melanoma and psoriasis were inhibited by the peptide. Conclusions: Taken together, these findings suggest mechanisms underlying immune homeostasis that could be exploited in the setting of cancer and autoimmune pathologies. Peptide administered together with checkpoint blockers in relevant models of autoimmunity and cancer may offer an opportunity to gain further insight into how immune tolerance can be retained in patients receiving cancer immunotherapy. Full article

Terpenes represent a structurally diverse class of natural compounds with increasing scientific interest due to their potential anti-inflammatory properties. This study investigates the in silico binding behavior of six plant-derived terpenes—α-pinene, β-pinene, menthol, camphor, limonene, and linalool—against four key enzymes in the arachidonic acid (AA) metabolic pathway: cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), and phospholipase A2 (PLA₂). AA serves as a reference for binding energy comparison. Blind rigid-body molecular docking is performed using AutoDock 4.2 and the Lamarckian Genetic Algorithm, with 100 runs per ligand–enzyme pair and the energy-based selection of optimal poses. The analysis includes binding energy (ΔG), inhibition constants (Ki), root-mean-square deviation (RMSD), and residue-level interactions. Several terpenes exhibit favorable binding energies and inhibition constants across the evaluated enzymes. For COX-1 and COX-2, menthol and camphor show low Ki values, indicating stable binding. Menthol and limonene also show the strongest affinities for PLA₂, exceeding AA. The focus is on compounds with potential to modulate arachidonic acid metabolism. In this context, β-pinene engages the catalytic site of PLA₂, linalool forms multiple contacts within key regions of 5-LOX, and menthol, α-pinene, and β-pinene align with functionally important regions in both COX isoforms. These targeted interactions suggest that the highlighted compounds may selectively interfere with enzymatic activity in inflammation-related pathways. By modulating key steps in AA metabolism, these terpenes may influence the biosynthesis of pro-inflammatory mediators, offering a promising avenue for the development of safer, plant-derived anti-inflammatory agents. The findings lay the groundwork for further experimental validation and the structure-based optimization of terpene-derived modulators. Full article

Granulosa cells (GCs) are essential for follicular growth and development, and their functional state critically impacts folliculogenesis. TAp73α, a transcriptionally active isoform of the p73 gene, is crucial for maintaining follicular integrity. In this study, we demonstrate that TAp73α overexpression promotes ferroptosis in bovine GCs by downregulating SLC7A11, depleting intracellular glutathione (GSH), and enhancing lipid peroxidation, particularly under Erastin treatment. By contrast, TAp73α knockdown restores antioxidant capacity, elevates GSH levels, and attenuates ferroptosis. To elucidate the underlying mechanism, untargeted metabolomic profiling revealed that TAp73α overexpression significantly altered the metabolic landscape of GCs, with marked enrichment in the glutathione metabolism pathway. Notably, betaine—a metabolite closely linked to redox homeostasis—was markedly downregulated. Functional assays confirmed that exogenous betaine supplementation restored SLC7A11 expression, increased GSH levels, and alleviated oxidative damage induced by either H₂O₂ or TAp73α overexpression. Moreover, betaine co-treatment effectively reversed lipid peroxide accumulation and mitigated TAp73α-induced ferroptosis. Collectively, our findings identify a novel mechanism by which TAp73α promotes ferroptosis in granulosa cells through the suppression of betaine and glutathione metabolism, highlighting betaine as a key metabolic modulator with promising protective potential. Full article

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease of 2019 (COVID-19) and has persistently caused infections since its emergence in late 2019. The main protease (Mpro) of SARS-CoV-2 plays a crucial role in its life-cycle; thus, it is an important target for drug development. One of the first virus-specific drugs that has been approved for the treatment of COVID-19 patients is Paxlovid, which contains nirmatrelvir, a covalent inhibitor of Mpro. Screening of inhibitor candidates and specificity studies also rely on efficient substrates and activity assays. Casein is one of the most commonly applied universal substrates that can be used to study a wide range of proteases, including SARS-CoV-2 Mpro. Casein is a known substrate for Mpro in vitro, but the specific casein isoform cleaved by Mpro remained unidentified, and the cleavage sites have yet to be determined. This work studied cleavage of α-, β- and κ-isoforms of bovine casein by SARS-CoV-2 Mpro, using in vitro and in silico approaches. The candidate cleavage sites were predicted in silico based on the protein sequences, and the cleavage positions were identified based on mass spectrometric analysis of cleavage fragments. Based on our results, only β-casein contains cleavage sites for Mpro and thus can be used as its substrate in vitro. The newly identified cleavage site sequences further widen the knowledge about the specificity of SARS-CoV-2 Mpro. Full article

Although some GABA_A receptor subtypes are involved in both the passive permeability of anions and the ATP-dependent recovery of neuronal anion concentrations, the molecular mechanisms that ensure the coordination of passive and active transport processes remain unclear. Here we used fluorescence measurements to investigate the role of genistein (tyrosine kinase inhibitor) and vanadate (tyrosine phosphatase and ATPase inhibitor) in modulating GABA_AR-mediated [Cl⁻]_i/[HCO₃⁻]_i changes and ATPase activity in rat cortical neurons and HEK 293FT cells expressing the heteropentameric α2β3γ2 GABA_AR isoform. We found that genistein plays an important role in the inhibition of passive GABA_AR-mediated Cl⁻ influx and Cl⁻ATPase activity, whereas vanadate plays an important role in the inhibition of Cl⁻, HCO₃⁻ATPase activity and ATP-dependent recovery of [HCO₃⁻]_i via changes in the formation of the phosphorylated intermediate. The effect of blockers was significantly restored in the presence of phenol. In behavioral experiments, the administration of phenol has been established to induce tremors and head twitching in rats, with the involvement of GABA_AR/ATPase in these behavioral responses. Genistein can reduce the adverse effects of phenol, thereby confirming the interaction of these chemicals when binding to binding receptor sites. While our data demonstrate the opposing roles of genistein and vanadate in modulating GABA_AR/ATPase function in a bicarbonate-dependent manner. Such multidirectional systems are considered to be bistable elements involved in the regulatory mechanisms of synaptic plasticity. Full article

Chondrocytes maintain cartilage integrity through coordinated regulation of extracellular matrix (ECM) synthesis and remodeling. These processes depend on ECM dynamic interactions, mediated by integrin-based focal adhesions and associated cytoskeletal components. While the roles of core adhesion proteins are well described, the involvement of sarcoglycans (SGs) remains unclear in chondrocytes. Drawing parallels from striated muscle, where the SG subcomplex stabilizes the sarcolemma, we hypothesized that SGs similarly integrate into chondrocyte adhesion complexes. This study investigated the SGs (α, β, γ, δ) expression with cytoskeletal and adhesion proteins, including actin and vinculin, in human chondrocytes cultured by immunofluorescence, qPCR, and siRNA-mediated silencing. All four SG isoforms were expressed in the cytoplasmic and membrane domains, with enrichment at focal adhesion sites. Double labeling revealed SG colocalization with F-actin stress fibers and vinculin, indicating integration into the core adhesion complex. Silencing of each SG resulted in disrupted actin stress fibers, diffuse vinculin distribution, reduced focal plaque number, and a change in cell morphology. These findings support the hypothesis that SGs regulate actin cytoskeletal dynamics and focal contact stabilization. Loss of SG function compromises chondrocyte shape and adhesion, highlighting the importance of these glycoproteins also in non-muscle cells. Full article

The enzymes in honey can originate not only from bees and the plants from which the bees collect pollen and nectar but also from feed provided by beekeepers. Enzymes that hydrolyze sucrose—present in honey (α-glucosidase) or honey adulterated with invert syrup (β-fructofuranosidase)—can be distinguished using zymography, where enzymatic bands are detected with nitroblue tetrazolium (NBT) after sugar removal via ultrafiltration. This method enables the identification of honey produced in hives that have been improperly fed with invert syrup, leading to the mixture of natural honey and syrup, and offers a practical tool to detect indirect adulteration. The NBT assay, in combination with ultrafiltration, was used to determine the isoelectric point of honey bee α-glucosidases. The pI value of 6.63 for isoforms found in the head, midgut, and natural honey extracts during winter can be attributed to α-glucosidase III. Two additional isoforms with isoelectric points of 5.20 and 5.77 were observed in the midgut extract and may correspond to α-glucosidase I and II. The difference between α-glucosidase and β-fructofuranosidase was confirmed using a substrate specificity test, followed by thin-layer chromatography, where it was confirmed that α-glucosidase from natural honey, bee head, and bee midgut does not hydrolyze raffinose, in contrast to yeast β-fructofuranosidase. Full article

KRAS is a pivotal oncoprotein that regulates cell proliferation and survival through interactions with downstream effectors such as RAF1. Despite significant advances in understanding KRAS biology, the structural and dynamic mechanisms of KRAS allostery remain poorly understood. In this study, we employ microsecond molecular dynamics simulations, mutational scanning, and binding free energy calculations together with dynamic network modeling to dissect how engineered DARPin proteins K27, K55, K13, and K19 engage KRAS through diverse molecular mechanisms ranging from effector mimicry to conformational restriction and allosteric modulation. Mutational scanning across all four DARPin systems identifies a core set of evolutionarily constrained residues that function as universal hotspots in KRAS recognition. KRAS residues I36, Y40, M67, and H95 consistently emerge as critical contributors to binding stability. Binding free energy computations show that, despite similar binding modes, K27 relies heavily on electrostatic contributions from major binding hotspots while K55 exploits a dense hydrophobic cluster enhancing its effector-mimetic signature. The allosteric binders K13 and K19, by contrast, stabilize a KRAS-specific pocket in the α3–loop–α4 motif, introducing new hinges and bottlenecks that rewire the communication architecture of KRAS without full immobilization. Network-based analysis reveals a strikingly consistent theme: despite their distinct mechanisms of recognition, all systems engage a unifying allosteric architecture that spans multiple functional motifs. This architecture is not only preserved across complexes but also mirrors the intrinsic communication framework of KRAS itself, where specific residues function as central hubs transmitting conformational changes across the protein. By integrating dynamic profiling, energetic mapping, and network modeling, our study provides a multi-scale mechanistic roadmap for targeting KRAS, revealing how engineered proteins can exploit both conserved motifs and isoform-specific features to enable precision modulation of KRAS signaling in oncogenic contexts. Full article

Background: Von Hippel-Lindau (VHL) disease, a hereditary cancer syndrome, is characterized by mutations in the VHL gene, which result in the stabilization of hypoxia-inducible factors (HIF)-1α and -2α, ultimately leading to the development of highly vascularized tumors, such as hemangioblastomas of the central nervous system (CNS-HBs). The standard treatment for these brain tumors is neurosurgical resection. However, multiple surgeries are often necessary due to tumor recurrence, which increases the risk of neurological sequelae. Thus, elucidation of the proliferative behavior of hemangioblastomas (with the aim of identifying biomarkers associated with tumor progression) and the development of pharmacological therapies could reduce the need for repeated surgical interventions and provide alternative treatment options for unresectable CNS-HBs. Belzutifan (Welireg™), a selective HIF-2α inhibitor and the only FDA-approved non-surgical option, has shown limited efficacy in CNS-HBs, highlighting the need for alternative therapeutic strategies. Results: In this study, primary cell cultures were successfully established from CNS-HB tissue samples of VHL patients, achieving a 75% success rate. These cultures were predominantly composed of stromal cells and pericytes. The proliferative patterns of patient-derived HB cell cultures significantly correlated with tumor burden and recurrence in VHL patients. Furthermore, flow cytometry, reverse transcription-PCR, and Western blot analyses revealed marked overexpression of both HIF-1α and HIF-2α isoforms in primary HB cells. In addition, evaluation of the therapeutic potential of acriflavine, a dual HIF-1α/HIF-2α inhibitor, demonstrated reduced HB cells viability, induced G2/M cell cycle arrest, and predominantly triggered necrotic cell death in patient-derived HB cultures. Conclusions: These results suggest that the in vitro proliferative dynamics of HB cell cultures may reflect clinical characteristics associated with CNS-HB progression, potentially serving as indicators to predict tumor development in patients with VHL. Furthermore, our findings support the simultaneous targeting of both HIF-1α and HIF-2α isoforms as a promising non-invasive therapeutic strategy. Full article

Hypoxia results in a wide range of adaptive physiological responses, including metabolic reprogramming, erythropoiesis, and angiogenesis. The response to hypoxia at the cellular level is mainly regulated by hypoxia-inducible factors (HIFs): HIF1α and HIF2α isoforms. Although structurally similar and overlapping gene targets, both isoforms can exhibit distinct expression patterns and functions in some conditions of hypoxia. The interaction between these isoforms, known as the “HIF switch”, determines their coordinated function under varying oxygen levels and exposure time. In angiogenesis, HIF-1α is rapidly stabilized under acute hypoxia, prompting a metabolic shift from oxidative phosphorylation to glycolysis and initiating angiogenesis by activating endothelial cells and extracellular matrix remodeling. Conversely, HIF-2α regulates cell responses to chronic hypoxia by sustaining genes critical for vascular remodeling and maturation. The current review highlights the different roles and regulatory mechanisms of HIF-1α and HIF-2α isoforms, focusing on their involvement in cell metabolism and the multi-step process of angiogenesis. Tuning the specific targeting of HIF isoforms and finding the right therapeutic window is essential to obtaining the best therapeutic effect in diseases such as cancer and vascular ischemic diseases. Full article

Objectives: Metabolic dysfunction-associated steatohepatitis (MASH) lacks effective therapies. This study aimed to evaluate the therapeutic potential of compound 3d, a novel elafibranor derivative, focusing on its dual mechanisms of PPAR pathway activation and p38 MAPK signaling inhibition. Methods: Integrated in vitro and in vivo approaches were employed. In vitro, free fatty acid (FFA)-induced lipid accumulation in L02 hepatocytes and lipopolysaccharides (LPSs)-stimulated inflammatory responses in RAW264.7 macrophages were used to evaluate lipid metabolism and anti-inflammatory effects. In vivo, a high-fat diet (HFD)-induced MASH model in C57BL/6 mice assessed serum biochemical parameters (triglycerides (TGs), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), alanine aminotransferase (ALT), aspartate transaminase (AST), tumor necrosis factor-α (TNF-α), nitric oxide (NO), and interleukin-6 (IL-6)), liver histopathology (H&E, Oil Red O, Masson staining), and proteomic profiling. Gut microbiota composition was analyzed via 16S rRNA sequencing. Western blotting quantified PPAR isoforms (γ/δ), downstream targets (Acox1, EHHADH, Acaa1), and p38 MAPK pathway proteins (p-p38, caspase-8, Bcl-2). Results: In vitro, 3d significantly reduced lipid accumulation (reduction in TG, p < 0.01) and inflammation (decrease in ALT activity, p < 0.05) in hepatocytes, while suppressing LPSs-induced TNF-α (63% reduction), NO (51% decrease), and IL-6 (48% reduction) in macrophages (p < 0.01). In vivo, 3d (30 mg/kg) lowered serum TG (39% decrease), TC (32% reduction), LDL-C (45% decline), and TNF-α (57% reduction) in HFD-fed mice (p < 0.05 vs. model), normalized AST/ALT levels, and ameliorated hepatic steatosis, ballooning, and fibrosis. Proteomics demonstrated PPARγ/δ activation (2.3–3.1-fold upregulation of Acox1, EHHADH, Acaa1; p < 0.001) and p38 MAPK pathway inhibition (54% reduction in p-p38, 61% decrease in caspase-8; 1.8-fold increase in Bcl-2; p < 0.01). Gut microbiota analysis revealed enrichment of beneficial taxa (Lactobacillus: 2.7-fold increase; Bifidobacterium: 1.9-fold rise) and reduced pathogenic Proteobacteria (68% decrease, p < 0.05). Conclusions: Compound 3d alleviates MASH via PPAR-mediated lipid metabolism enhancement and p38 MAPK-driven inflammation/apoptosis suppression, with additional gut microbiota modulation. These findings highlight 3d as a multi-target therapeutic candidate for MASH. Full article

The human laminin family is composed of five α, four β, and three γ chains. Laminins are heterotrimers of α, β, and γ chains. Laminins play critical roles during organogenesis, mostly as basement membrane components. The expression of all and the localization of most laminin chains were characterized in mouse developing teeth. Primary laminin isoforms in basement membranes along the inner enamel epithelium before the secretory stage and outside of the outer enamel epithelium were laminins 111 (α1β1γ1) and 511. The mouse laminin α3 chain has two variants, α3A and α3B. Although a basement membrane structure is absent, laminin 3A32 was localized along the secretory surface of the secretory stage ameloblast Tomes’ processes. Laminin 3A32 was localized along the atypical basement membrane of maturation stage ameloblasts and the specialized basement membrane of junctional epithelium facing the enamel surface. The endothelial basement membrane in the dental papilla and outside of the enamel organ contained laminins 411 and 511. Laminin 332 was detected in the extracellular matrix but not the basement membrane of the apical loop. Laminin 111 was localized in the extracellular matrix of the apical dental papilla without forming a visible basement membrane. These findings suggest the multifaceted functions of laminins in tooth development and set the foundation for functional investigations. Full article

Background/Objectives: Gestational trophoblastic disease (GTD) is a group of disorders including complete, partial, and invasive/metastatic hydatidiform moles, as well as gestational trophoblastic neoplasia (GTN) (choriocarcinoma; placental site trophoblastic tumor, PSTT; epithelioid trophoblastic tumor, ETT; or mixed forms). These entities are characterized by increased trophoblast proliferation, rarely complicated by hyperthyroidism. Methods: Our systematic literature review (PRISMA guidelines; PubMed, Web of Science, and Scopus databases) searched for histologically confirmed cases of GTN associated with clinical or subclinical hyperthyroidism. We described the clinical–pathologic features and the pathways of hyperthyroidism in GTD. Results: We identified just 32 choriocarcinomas and one PSTT; other non-histologically confirmed cases could have been identified, as some patients received a clinical diagnosis based on serum human chorionic gonadotropin (hCG) levels and imagining data and were treated accordingly. As regards choriocarcinomas, patients’ age range was 15–45 (mean 27) years. Metastases involved the lungs (53%), brain (25%), and liver (19%) (less frequently, the kidneys, spleen, ovaries, vagina, pelvis/abdomen, or thyroid). The time to recurrence range was 1–36 (mean 12) months. On follow-up, 10 patients (32%) were alive with disease and 6 (19%) showed no evidence of disease, while most of the women (15 cases, 48%) died of disease. The hCG level range was 10,000–3,058,000,000 (mean 128,957,613) IU/L. At least some symptoms and/or signs of hyperthyroidism were evident with variable intensity in most cases and significantly improved within 2–3 weeks after treatment. Conclusions: Increased trophoblast proliferation could stimulate thyroid function via increasing the half-life of thyroxine-binding globulin. Secondly, increased hCG demonstrates cross-reactivity with the thyroid-stimulating hormone due to similar α-subunits. Moreover, basic isoforms of hCG may facilitate thyrotropic activity. Full article

Bile acids (BAs) are important signaling molecules in the gastrointestinal (GI) tract and are associated with health and disease in humans and animals. Intestinal bacteria transform BA through deconjugation, dehydroxylation, and epimerization reactions, producing various isoforms, many of which have not been investigated in companion animal diseases. We aimed to develop and analytically validate a novel liquid chromatography–tandem mass spectrometry (LC-MS/MS) method for the quantification of 30 BAs in dog feces, with a simple extraction procedure and on-line solid-phase extraction. Validation demonstrated good accuracy, precision, sensitivity, spiking recovery, dilution, and stability for 29 BAs. The method was applied to fecal samples from healthy dogs (H; n = 121) and dogs with chronic enteropathy (CE; n = 58). The immediate and downstream products of bacterial 7α-dehydroxylation reactions with cholic acid were lower in concentration in dogs with CE when compared to healthy dogs (deoxycholic acid, 3-oxo-deoxycholic acid, and 12-oxo-lithocholic acid; q < 0.001). Across all fecal samples, the products of hydroxysteroid dehydrogenase (including oxo- and iso-BA) made up an average of 30% of the total measured fecal BA pool (glycine-BA, 0.1%; taurine-BA, 2.2%; unconjugated BA, 53%). Full article

Background: Fabry disease (FD) results from pathogenic GLA variants, causing lysosomal α-galactosidase A (α-GalA) deficiency and sphingolipid ceramide trihexoside (Gb3 or THC) accumulation. Disease phenotype varies widely but cardiomyopathy is commonly life-limiting. As a multisystemic disorder, FD initiates at the cellular level; however, the mechanism/s underlying Gb3-induced cell dysfunction remains largely unknown. This study established an in vitro mutation-specific model of Fabry cardiomyopathy using human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes to explore underlying cell pathology. Methods: Skin biopsies from consenting Fabry patients and normal control subjects were reprogrammed to iPSCs then differentiated into cardiomyocytes. The GLA mutations in Fabry cell lines were corrected using CRISP-Cas9. Phenotypic characteristics, α-Gal A activity, Gb3 accumulation, functional status, and lipid analysis were assessed. Cardiomyocytes derived from two patients with severe clinical phenotype and genotypes, GLA^c.851T>C, GLA^{c.1193_1196del}, and their respective corrected lines, GLA^{corr c.851T>C}, GLA^{corr c.1193_1196del}, were selected for further studies. Results: Cardiomyocytes derived from individuals with FD iPSCs exhibited stable expression of cardiomyocyte markers and spontaneous contraction, morphological features of FD, reduced α-Gal A activity, and accumulation of Gb3. Lipidomic profiling revealed differences in the Gb3 isoform profile between the control and FD patient iPSC-derived cardiomyocytes. Contraction strength was unchanged but relaxation after contraction was delayed, mimicking the diastolic dysfunction typical of Fabry cardiomyopathy. Conclusions: iPSC-derived cardiomyocytes provide a useful model to explore aspects of Fabry cardiomyopathy, including disruptions in sphingolipid pathways, proteomics, and multigene expression that together link genotype to phenotype. The platform potentially offers broad applicability across many genetic diseases and offers the prospect of testing and implementation of individualised therapies. Full article