Search Results (3,849)

An inorganic–organic hybrid nano-adsorbent was prepared by chemical immobilisation of an organic Schiff base Cu (II) ion receptor, DHB ((E)-N-(1-(2-hydroxy-6-methyl-4-oxo-4H-pyran-3-yl) ethylidene) benzohydrazide), a selective dehydroacetic acid-based chemosensor, onto a mesoporous silica support. In order to prepare the sorbent, the silylating agent was anchored onto the silica. During this procedure, 3-Chloropropyl trimethoxy silane (CPTS) was attached to the surface, increasing hydrophobicity. By immobilising DHB onto the CPTS platform, the silica surface was activated, and as a result the coordination chemistry of the Schiff base generated a hybrid adsorbent with the capability to rapidly sequestrate Cu (II) ions from wastewater, as an answer to combat growing Waste Electrical and Electronic Equipment (WEEE) contamination in water supplies, in the wake of a prolonged consumerism mentality and boom in cryptocurrency mining. The produced hybrid materials were characterised by FTIR, proximate and ultimate analysis, nitrogen physisorption, PXRD, SEM, and TEM. The parameters influencing the removal efficiency of the sorbent, including pH, initial metal ion concentration, contact time, and adsorbent dosage, were optimised to achieve enhanced removal efficiency. Under optimal conditions (pH 7.0, adsorbent dosage 3 mg, contact time of 70 min, and 25 °C), Cu (II) ions were quantitatively sequestered from the sample solution; 93.1% of Cu (II) was removed under these conditions. The adsorption was found to follow pseudo-second-order kinetics, and Langmuir model fitting affirmed the monolayer adsorption. Full article

Mutations in TP53 inhibit p53 protective behaviors including cell cycle arrest, DNA damage repair protein recruitment, and apoptosis. The ubiquity of p53 in genome-stabilizing functions leads to an aberrant tumor microenvironment in TP53-mutated myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Profound immunosuppression mediated by myeloid-derived suppressor cells, the upregulation of cytokines and cell-surface receptors on leukemic cells, the suppression of native immune regulator cells, and metabolic aberrations in the bone marrow are features of the TP53-mutated AML/MDS marrow microenvironment. These localized changes in the bone marrow microenvironment (BMME) explain why traditional therapies for MDS/AML, including chemotherapeutics and hypomethylating agents, are not as effective in TP53-mutated myeloid neoplasms and demonstrate the dire need for new treatments in this patient population. The unique pathophysiology of TP53-mutated disease also provides new therapeutic approaches which are being studied, including intracellular targets (MDM2, p53), cell-surface protein biologics (immune checkpoint inhibitors, BiTE therapy, and antibody–drug conjugates), cell therapies (CAR-T, NK-cell), signal transduction pathways (Hedgehog, Wnt, NF-κB, CCRL2, and HIF-1α), and co-opted biologic pathways (cholesterol synthesis and glycolysis). In this review, we will discuss the pathophysiologic anomalies of the tumor microenvironment in TP53-mutant MDS/AML, the hypothesized mechanisms of chemoresistance it imparts, and how novel therapies are leveraging diverse therapeutic targets to address this critical area of need. Full article

The zoonotic potential of bat coronaviruses, especially HKU5, is a significant issue because of their capacity to utilize human angiotensin-converting enzyme 2 (ACE2) as a receptor for cellular entry. This study offers structural insights into the binding kinetics of HKU5 (Bat Merbecovirus HKU5) receptor-binding domain (RBD) spike protein with human ACE2 through a multiscale computational method. This study employed structural modeling, 300-nanosecond (ns) molecular dynamics (MD) simulations, alanine-scanning mutagenesis, and computational peptide design to investigate ACE2 recognition by the HKU5 RBD and its interactions with peptides. The root mean square deviation (RMSD) investigation of HKU5–ACE2 complexes indicated that HKU5 exhibited greater flexibility than SARS-CoV-2, with RMSD values reaching a maximum of 1.2 nm. Free energy analysis, Molecular Mechanics/Generalized Born Surface Area (MM/GBSA), indicated a more robust binding affinity of HKU5 to ACE2 (ΔG_Total = −21.61 kcal/mol) in contrast to SARS-CoV-2 (ΔG_Total = −5.82 kcal/mol), implying that HKU5 binding with ACE2 had higher efficiency. Additionally, a peptide was designed from the ACE2 interface, resulting in the development of 380 single-site mutants by mutational alterations. The four most promising mutant peptides were selected for 300-nanosecond (ns) MD simulations, subsequently undergoing quantum chemical calculations (DFT) to evaluate their electronic characteristics. MM/GBSA of −37.83 kcal/mol indicated that mutant-1 exhibits the most favorable binding with HKU5, hence potentially inhibiting ACE2 interaction. Mutant-1 formed hydrogen bonds involving Glu74, Ser202, Ser204, and Asn152 residues of HKU5. Finally, QM/MM calculations on the peptide–HKU5 complexes showed the most favorable ΔE_interaction of −170.47 (Hartree) for mutant-1 peptide. These findings offer a thorough comprehension of receptor-binding dynamics and are crucial for evaluating the zoonotic risk associated with HKU5-CoV and guiding the design of receptor-targeted antiviral treatments. Full article

To prepare and characterize low-bitter angiotensin-converting enzyme (ACE)-inhibitory peptides from sesame protein, a triple-enzyme hydrolysis system was optimized using mixture design and response surface methodology. The resulting hydrolysate was separated by ultrafiltration and medium-pressure chromatography, followed by identification through nano-liquid chromatography–electrospray ionization-tandem mass spectrometry. Finally, the mechanism of typical low-bitter ACE-inhibitory peptides was elucidated by molecular docking and molecular dynamics simulation. Results showed that the optimal enzyme activity ratio of 1:0.94:1.07 for Alcalase, trypsin, and Flavourzyme, combined with optimized hydrolysis conditions (E/S ratio of 126,793.03 nkat/g, pH 8.40, 4.82 h hydrolysis time, and 45 °C), resulted in a peptide yield of 93.19 ± 0.14%, ACE-inhibitory rate of 95.92 ± 0.23%, and bitter value of 3.15 ± 0.09. APQLGR and APWLR exhibited high ACE-inhibitory activity and minimal bitterness among the seventeen identified peptides. Although both peptides bound to the S1 pocket and Zn²⁺ catalytic site of ACE, APWLR exhibited an additional interaction with the S2 pocket. Both peptides were predicted to antagonize the bitter taste receptor T2R14 by forming stable complexes with key residues, but two complexes exhibited distinct mechanisms of stabilization. This work demonstrates a method for producing dual-functional peptides from sesame protein, paving the way for their application in functional foods. Full article

Neuroprotection represents a promising approach for mitigating retinal degeneration. Cord blood serum (CBS), rich in trophic factors such as the brain-derived neurotrophic factor (BDNF), has shown therapeutic potential for ocular surface diseases; however, its role in retinal neuroprotection remains underexplored. This study evaluates the protective effects of CBS on retinal pigment epithelium (ARPE-19) and photoreceptor-like (661W) cells exposed to oxidative stress. Cells were cultured in media supplemented with fetal bovine serum (FBS) or CBS with either high (CBS-H) or low (CBS-L) BDNF content. Oxidative stress was induced using hydrogen peroxide (H₂O₂), and cell viability was measured via an MTS assay. ZO-1 expression was analyzed in ARPE-19 cells to assess tight junction integrity, while mitochondrial function in 661W cells was examined using MitoRed staining. TrkB receptor involvement was investigated using the inhibitor K252a and Western blot analysis. CBS significantly improved cell viability under oxidative conditions. CBS-H increased ZO-1 expression in ARPE-19 cells, indicating preserved epithelial integrity. In 661W cells, CBS maintained mitochondrial integrity and enhanced TrkB phosphorylation, while TrkB inhibition reduced its protective effect. These findings indicate that CBS confers neuroprotection through BDNF-TrkB signaling together with other trophic factors, supporting its potential as a multifactorial therapeutic strategy for retinal degeneration that deserves further exploration. Full article

Chemokines play a central role in orchestrating neutrophil recruitment from the bloodstream and determining their effector functions at sites of infection. Chemokine activity is determined by three key properties: reversible monomer–dimer equilibrium, binding to glycosaminoglycans (GAGs), and signaling through the GPCR class of receptors CXCR1 and CXCR2. In this study, we investigated the structural basis of CXCL8 monomer and dimer binding to GAG chondroitin sulfate (CS) using nuclear magnetic resonance (NMR) spectroscopy, docking, and molecular dynamics (MD) measurements. Our studies reveal that both the monomer and dimer use essentially the same set of basic residues for binding, that the interface is extensive, that the dimer is the high-affinity CS ligand, and that the CS-binding residues form a contiguous surface within a monomer. Several of these residues also participate in receptor interactions, suggesting that CS-bound CXCL8 is likely impaired in its ability to bind receptors. Notably, we observe that the same basic residues are involved in binding CS and heparin/heparan sulfate, even though these GAGs differ in backbone structures and sulfation patterns. We conclude that the strategic distribution and topology of basic residues on the CXCL8 scaffold enable engagement with diverse GAG structures, which likely allows fine-tuning receptor signaling to regulate neutrophil trafficking and effector functions. Full article

Systemic lupus erythematosus (SLE) is a chronic and refractory autoimmune disease characterized by multi-organ damage, for which reliably safe and effective treatment remains an unmet need. Autoantibodies, secreted by autoreactive B cells, deposition is the central pathogenesis of organ damage in SLE. Current studies reported B cell receptor and B cell activating factor (BAFF)-mediated signals regulate the activation and survival of B cells and production of autoantibodies. We showed that marginal zone B cells and CD11c⁺T-bet⁺ autoreactive B cells expressed higher levels of BAFF receptor and BTK in MRL/lpr mice. Here, a liposome-delivery system capable of targeting BAFFR^high autoreactive B cells by conjugating anti-BAFFR antibody on the surface of the PEG-liposomes and loading BTK-inhibitor ibrutinib (BTEL) was rationally designed. Notably, the BTEL nanoparticles could inhibit the survival and activation of B cells, and systemic administration of BTEL could alleviate the development of the lupus mouse model by decreasing the production of anti-dsDNA autoantibodies, along with reduced secretion of inflammatory cytokines and kidney damage, and without apparent side effects. These findings suggest the potential of BTEL in targeting autoreactive B cells, blocking signaling pathways, and improving the efficacy of BTK inhibitors, providing a promising therapeutic approach for SLE, while also reducing toxicity. Full article

Neonicotinoids are synthetic nicotine-like compounds extensively used globally as insecticides for agricultural and urban purposes. Neonicotinoid-contaminated produce is a major public health concern worldwide. Limited epidemiological studies have shown an association of neonicotinoid exposure with abnormal semen analysis. This study aimed to elucidate the potential disruption of the androgen receptor (AR) by eight common neonicotinoids, including imidacloprid (IMI), acetamiprid, clothianidin, thiamethoxam, dinotefuran, thiacloprid (THI), nitenpyram, and nithiazine using docking and molecular dynamics (MD) simulation. The results showed good binding strength of all compounds (except THI) with AR, as indicated by high binding energy, high binding affinity, and number of bonding interactions. The results of MD simulation supported the conformational stability and structural dynamic behavior of the AR-IMI (receptor-neonicotinoid) complex upon binding. This was indicated by root mean square deviation showing stability of the complex; the root mean square fluctuation showing minimized residual fluctuations upon binding; the radius of gyration showing greater compactness of the protein structure; the solvent-accessible surface area showing no changes upon binding; and the Gibbs funnel energy of the landscape showing a stable conformation state with minimum energy and slight change in size and position of the sampled energy basin of the AR, with a stable equilibrium. Taken together, the structural dynamics results showed that neonicotinoids are bound stably in the same ligand-binding domain of the AR as the native ligand testosterone. This may perturb the natural binding of testosterone with the AR and potentially disrupt downstream signaling and biological pathways, leading to male reproductive dysfunction. Full article

Clostridial neurotoxins, botulinum neurotoxins (BoNTs), and tetanus neurotoxin (TeNT) are potent toxins responsible for severe diseases, botulism and tetanus, respectively. BoNTs associate with non-toxic proteins (non-toxic non-hemagglutinin, hemagglutinins, and OrfXs), which protect BoNTs against acidic pH and protease degradation and facilitate BoNT passage through the intestinal barrier. TeNT enters motor neurons and undergoes a retrograde axonal transport until the target inhibitory interneurons in the central nervous system. BoNTs and TeNT recognize specific cell surface receptors which consist of complex sets of protein(s)-glycan-gangliosides and determine specific cell entry pathways. Recent data on structural and functional investigations of BoNT and TeNT receptors bring a better understanding of toxin trafficking in the host and entry into target neuronal cells, which is useful for the development of updated strategies of prevention and treatment of the corresponding diseases. Since clostridial neurotoxins, notably BoNTs, are important therapeutic tools, detailed knowledge of their activity opens the way of the development of engineered molecules for specific clinical applications. Full article

The COVID-19 pandemic accelerated vaccine innovation but also exposed weaknesses in global access and manufacturing. Yeast-based platforms, particularly Saccharomyces cerevisiae and Pichia pastoris, also known as Komagataella phaffii, offer a practical complement to vector systems. These eukaryotic microorganisms combine safety, scalability, and cost-effectiveness with the ability to express complex antigens and assemble virus-like particles. Building on the success of the recombinant hepatitis B vaccine, recent advances in glycoengineering, CRISPR-based host optimization, and surface display technologies have expanded the utility of yeast-based platforms for the rapid development of vaccines. Yeast-derived SARS-CoV-2 receptor-binding domain (RBD) subunit vaccines, such as Corbevax and Abdala (CIGB-66), demonstrate that affordable, immunogenic, and thermostable products are feasible at scale. Emerging innovations in glycan humanization, thermostable formulations, and oral or mucosal delivery highlight the potential of yeast-based vaccines for decentralized manufacturing and equitable pandemic preparedness. This review summarizes recent technical and clinical progress in yeast-based vaccine research, positioning these platforms as accessible and adaptable tools for future outbreak responses and global immunization strategies. Full article

Heterotrophic bacteria and microalgae are key regulators of marine biogeochemical cycles. The phycosphere, a nutrient-rich microenvironment surrounding microalgae, serves as a crucial interface for bacterial–algal interactions. Our previous work identified Opacimonas immobilis LMIT016^T, a phycosphere isolate from the diatom Actinocyclus curvatulus that possesses the smallest genome within the Alteromonadaceae family. However, its adaptation mechanisms to the phycosphere remain unclear, particularly given its extensive genome streamlining, a process involving the selective loss of non-essential and energetically costly genes to enhance fitness in nutrient-specific niches. Here, the co-cultivation experiments demonstrated significant mutual growth promotion between LMIT016^T and its host microalgae, with the bacterium forming dense attachments on diatom surfaces. Genomic analysis revealed that in addition to loss of motility-related genes, the strain exhibits a substantial reduction in c-di-GMP signaling components, including both synthases and receptors. Conversely, LMIT016^T harbors numerous genes essential for extracellular polysaccharide (EPS) biosynthesis and adhesion, supporting long-term attachment and biofilm formation. Other retained genes encode pathways for nutrient acquisition, stress response, and phosphate and nitrogen metabolism, reflecting its adaptations to the nutrient-rich phycosphere. Furthermore, the genome of LMIT016^T encodes two polysaccharide utilization loci (PULs) targeting laminarin and α-1,4-glucans, whose functions were experimentally validated by the transcriptional induction of the corresponding carbohydrate-active enzyme genes. These findings indicate that this strain counterbalances genome reduction by enhancing its attachment capabilities and metabolic specialization on algal polysaccharides, potentially facilitating stable association with diatom cells. Our results suggest that genome streamlining may represent an alternative ecological strategy in the phycosphere, highlighting a potential evolutionary trade-off between metabolic efficiency and niche specialization. Full article

Glucagon-like peptide-1 (GLP-1) receptor agonists and sodium–glucose cotransporter-2 (SGLT2) inhibitors have reshaped pharmacological management of type 2 diabetes, but emerging safety signals suggest a possible association with intestinal obstruction. Because many candidates for these agents already harbor risk factors for ileus and bowel obstruction, clarifying agent- and dose-specific gastrointestinal safety is clinically important. We aimed to re-evaluate the risk of intestinal obstruction across individual GLP-1 receptor agonists and SGLT2 inhibitors, with particular attention to dose stratification. We systematically searched eight databases through 21 January 2025 to identify randomized controlled trials (RCTs) comparing GLP-1 receptor agonists or SGLT2 inhibitors with placebo or active comparators in adults. The primary outcome was incident intestinal obstruction (small or large bowel). A frequentist random-effects network meta-analysis estimated odds ratios (ORs) with 95% confidence intervals (CIs) across drugs and dose tiers; Bayesian models and surface under the cumulative ranking (SUCRA) metrics were used for sensitivity analyses and treatment ranking. Risk of bias and certainty of evidence were assessed with standard Cochrane and GRADE-adapted tools. Fifty RCTs (47 publications; 192,359 participants) met inclusion criteria. Overall, canagliflozin use was associated with a higher incidence of intestinal obstruction than control therapies (OR 2.56, 95% CI 1.01–6.49), corresponding to an absolute risk difference of 0.15% and a number needed to harm of 658. High-dose canagliflozin (300 mg/day) showed the clearest signal (OR 3.42, 95% CI 1.08–10.76). In contrast, liraglutide was associated with a lower risk of intestinal obstruction (OR 0.44, 95% CI 0.24–0.81), with an absolute risk reduction of 0.34% and a number needed to treat of 295. No other GLP-1 receptor agonist or SGLT2 inhibitor demonstrated a statistically significant increase in obstruction risk. Frequentist and Bayesian analyses yielded concordant estimates and rankings. From a randomized-trial perspective, intestinal obstruction risk is not elevated for most GLP-1 receptor agonists and SGLT2 inhibitors. A dose-dependent safety signal was observed only for high-dose canagliflozin, whereas liraglutide may confer a protective effect. These findings refine gastrointestinal safety profiles for modern antidiabetic agents and may inform perioperative bowel management, drug selection, and dose optimization in patients at risk for ileus or adhesive obstruction. Full article

Chalcone-based derivatives were designed as dual-acting ligands targeting the histamine H₃ receptor (H₃R) and monoamine oxidase B (MAO-B), based on the lead compound DL76. Three series of compounds (1–18) were synthesised and characterised, including simple chalcones (1–9) and piperidinyl chalcones (10–18). All piperidinyl derivatives exhibited nanomolar affinity for human H₃R (hH₃R), with compounds 10–12 achieving K_i values ≤ 30 nM. Simple chalcones showed potent human MAO-B (hMAO-B) inhibition (IC₅₀: 0.85–337 nM), especially 3,4-dichloro derivatives. Compound 15 was the most active hybrid, with a K_i of 46.8 nM for hH₃R and an IC₅₀ of 212.5 nM for hMAO-B. Molecular docking and 250 ns simulations revealed stabilising interactions at both binding sites and clarified structural features behind dual activity. Preliminary ADMET profiling showed low Caco-2 permeability and rapid microsomal metabolism, mainly via hydroxylation. Compound 15 exhibited micromolar cytotoxicity in SH-SY5Y and HepG2 cells, induced G2/M arrest, disrupted mitochondrial homeostasis, and was genotoxic in Peripheral Blood Mononuclear Cells (PBMCs). Additionally, for H₃R ligands (15, DL76, pitolisant), the study reports the first use of Surface Plasmon Resonance Microscopy (SPRM) to assess their interactions with this receptor. Therefore, piperidinyl chalcones show promise as ligands with dual action on H₃R and MAO-B, useful in the treatment of neurodegeneration and/or CNS cancers. Full article

Valsartan (Val)—a lipophilic non-peptide angiotensin II type 1 receptor antagonist—is highly effective against hypertension and displaying limited solubility in water (3.08 μg/mL), thereby resulting in low oral bioavailability (23%). The limited water solubility of antihypertensive drugs can pose a challenge, particularly for rapid and precise administration. Herein, we synthesize and characterize valsartan-containing silver nanoparticles (Val-AgNPs) using Mangifera indica leaf extracts. The physicochemical, structural, thermal, and pharmacological properties of these nano-conjugates were established through various analytical and structural tools. The spectral shifts in both UV-visible and FTIR analyses indicate a successful interaction between the valsartan molecule and the silver nanoparticles. The resulting nano-conjugates are spherical and within the size range of 30–60 nm as revealed in scanning electron-EDS and atomic force micrographs. The log-normal distribution of valsartan-loaded nanoparticles, with a size range of 30 to 60 nm and a mode of 54 nm, indicates a narrow, monodisperse, and highly uniform particle size distribution. This is a favorable characteristic for drug delivery systems, as it leads to enhanced bioavailability and a consistent performance. Dynamic Light Scattering (DLS) analysis of the Val-AgNPs indicates a polydisperse sample with a tendency toward aggregation, resulting in larger effective sizes in the suspension compared to individual nanoparticles. The accompanying decrease in zeta potential (to −19.5 mV) and conductivity further supports the idea that the surface chemistry and stability of the nanoparticles changed after conjugation. Differential scanning calorimetry (DSC) demonstrated the melting onset of the valsartan component at 113.99 °C. The size-dependent densification of the silver nanoparticles at 286.24 °C correspond to a size range of 40–60 nm, showing a significant melting point depression compared to bulk silver due to nanoscale effects. The shift in Rf for pure valsartan to Val-AgNPs suggests that the interaction with the AgNPs alters the compound’s overall polarity and/or its interaction with the stationary phase, complimented in HPTLC and HPLC analysis. The stability and offloading behavior of Val-AgNPs was observed at pH 6–10 and in 40% and 80% MeOH. In addition, Val-AgNPs did not reveal hemolysis or significant alterations in blood cell indices, confirming the safety of the nano-conjugates for biological application. In conclusion, these findings provide a comprehensive characterization of Val-AgNPs, highlighting their potential for improved drug delivery applications. Full article

Background: Epicardial adipose tissue (EAT) is a metabolically active organ implicated in coronary artery disease (CAD); however, its role in aortic stenosis (AS) remains unclear. Advanced glycation end products (AGEs) and their receptor (RAGE) promote cardiovascular tissue inflammation. This study aimed to investigate whether inflammatory activity within the EAT, particularly involving the AGEs-RAGE axis, is associated with AS. Methods: We studied 42 patients (isolated AS, n = 15; AS with CAD, n = 15; and CAD alone, n = 12) undergoing surgical intervention, along with 10 autopsy controls. EAT volume was assessed via computed tomography and indexed to body surface area. Furthermore, macrophage infiltration (CD68) and RAGE expression in EAT samples were analyzed using immunohistochemistry and immunofluorescence imaging. Results: EAT volume index was significantly higher in all surgical groups than in the controls (p < 0.001). These surgical groups also had markedly increased CD68- and RAGE-positive cells compared with the controls (p < 0.001), with colocalization detected by means of immunofluorescence imaging. Additionally, the EAT volume index independently and positively correlated with CD68-positive cell counts (p = 0.021), and causal mediation analysis suggested that it promotes CD68-positive macrophage activation through pathways mediated by RAGE-positive cells (p = 0.024). Inflammatory cells did not correlate with AS severity (maximum aortic jet velocity, mean pressure gradient, aortic valve area). Conclusions: EAT in AS exhibits increased macrophage infiltration and RAGE expression. Therefore, the AGEs-RAGE axis may contribute to local inflammatory activity, and EAT can be a potential biomarker and therapeutic target in AS. Full article