Search Results (9,080)

Arginine kinase is a key phosphagen kinase in invertebrates that facilitates rapid ATP regeneration by reversibly transferring phosphate groups between phosphoarginine and ADP. Structural studies have shown that the enzyme adopts distinct conformations in its ligand-free and ligand-bound states, known as the “open” and “closed” forms, respectively. These conformational changes are crucial for catalytic activity, enabling precise positioning of active-site residues and loop closure during phosphoryl transfer. Transition-state analog complexes have provided additional insights by mimicking intermediate states of catalysis, supporting the functional relevance of the open/closed structural model. Furthermore, studies across multiple species reveal how monomeric and dimeric forms of arginine kinase contribute to its allosteric regulation and substrate specificity. Beyond its metabolic role, arginine kinase is also recognized as a major allergen in crustaceans. Its structural uniqueness and absence in vertebrates make it a promising candidate for selective drug targeting. By integrating crystallographic data with functional context, this review highlights conserved features and species-specific variations of arginine kinase that may inform the design of inhibitors. Such molecules have the potential to serve both as antiparasitic agents and as novel therapeutics to manage crustacean-related allergic responses in humans. Full article

Background: Thyroid eye disease (TED) is a rare autoimmune orbital disorder predominantly associated with Graves’ disease. It is characterized by orbital inflammation, tissue remodeling, and potential visual morbidity. Conventional therapies, particularly systemic glucocorticoids, offer only partial symptomatic relief, failing to reverse chronic structural changes such as proptosis and diplopia, and are associated with substantial adverse effects. This review aims to synthesize recent developments in understandings of TED pathogenesis and to critically evaluate emerging therapeutic strategies. Methods: A systematic literature review was conducted using MEDLINE, Embase, and international clinical trial registries focusing on pivotal clinical trials and investigational therapies targeting core molecular pathways involved in TED. Results: Current evidence suggests that TED pathogenesis is primarily driven by the autoimmune activation of orbital fibroblasts (OFs) through thyrotropin receptor (TSH-R) and insulin-like growth factor-1 receptor (IGF-1R) signaling. Teprotumumab, a monoclonal IGF-1R inhibitor and the first therapy approved by the U.S. Food and Drug Administration for TED, has demonstrated substantial clinical benefit, including improvements in proptosis, diplopia, and quality of life. However, concerns remain regarding relapse rates and treatment-associated adverse events, particularly hearing impairment. Investigational therapies, including next-generation IGF-1R inhibitors, small-molecule antagonists, TSH-R inhibitors, neonatal Fc receptor (FcRn) blockers, cytokine-targeting agents, and gene-based interventions, are under development. These novel approaches aim to address both inflammatory and fibrotic components of TED. Conclusions: Teprotumumab has changed TED management but sustained control and toxicity reduction remain challenges. Future therapies should focus on targeted, mechanism-based, personalized approaches to improve long-term outcomes and patient quality of life. Full article

Albumin-binding agents enhance tumor uptake of radiopharmaceuticals targeting prostate-specific membrane antigens (PSMAs) in radiotherapy. We synthesized PSMA-NARI-56, a molecule with both PSMA targeting activity and albumin-binding moiety, labeled with ¹⁷⁷Lu as the therapeutic agent. The aim of this study was to determine the specific binding of ¹⁷⁷Lu-PSMA-NARI-56 towards PSMA, assess its biodistribution, and evaluate therapeutic effectiveness by tumor-bearing mice. The effect of ¹⁷⁷Lu-PSMA-NARI-56 viability of PSMA-positive cell (LNCaP) was evaluated. Biodistribution and endoradiotherapy studies were utilized to determine the distribution, targeting, and anti-tumor efficacy by tumor-bearing mice identified by ¹¹¹In-PSMA-NARI-56. ¹⁷⁷Lu-PSMA-NARI-56 exhibited a significant impact on the viability of the LNCaP cell. Biodistribution results revealed the maximum tumor uptake of ¹⁷⁷Lu-PSMA-NARI-56 occurring within 24 h, reaching 40.56 ± 10.01%ID/g. In radionuclide therapy, at 58 days post-injection (p.i.), ¹⁷⁷Lu-PSMA-NARI-56 demonstrated superior tumor inhibition (98%) compared to ¹⁷⁷Lu-PSMA-617 (58%), and the mouse survival rate after 90 days of radiotherapy (90%) was also higher than that of ¹⁷⁷Lu-PSMA-617 (30%) in LNCaP tumor-bearing mice. In the PSMA-positive animal model, ¹⁷⁷Lu-PSMA-NARI-56 shows higher potential radiotheranostic and prolonged accumulation (identify by ¹¹¹In-PSMA-NARI-56/nanoSPECT/CT image), offering the potential for improved treatment effectiveness and increased survival rates when compared to ¹⁷⁷Lu-PSMA-617. Full article

Macrophage-mediated inflammation is known to be involved in the epithelial–mesenchymal transition (EMT) of various types of cancer. This makes macrophage-derived inflammatory factors prime targets for the development of new treatments. This study uncovers the therapeutic potential and action mechanism of DAB-2-28, a small-molecule derived from para-aminobenzoic acid, in the treatment of breast cancer. The luminal MCF-7 and the triple-negative MDA-MB-231 cancer cell lines used in this study represent, respectively, breast cancers in which the differentiation states are related to the epithelial phenotype of the mammary gland and breast cancers expressing a highly aggressive mesenchymal phenotype. In MCF-7 cells, soluble factors from macrophage-conditioned media (CM-MØ) induce a characteristic morphology of mesenchymal cells with an upregulated expression of Snail1, a mesenchymal marker, as opposed to a decrease in the expression of E-cadherin, an epithelial marker. DAB-2-28 does not affect the differential expression of Snail1 and E-cadherin in response to CM-MØ, but negatively impacts other hallmarks of EMT by decreasing invasion and migration capacities, in addition to MMP9 expression and gelatinase activity, in both MCF-7 and MDA-MB-231 cells. Moreover, DAB-2-28 inhibits the phosphorylation of key pro-EMT transcriptional factors, such as NFκB, STAT3, SMAD2, CREB, and/or AKT proteins, in breast cancer cells exposed to different EMT inducers. Overall, our study provides evidence suggesting that inhibition of EMT initiation or maintenance is a key mechanism by which DAB-2-28 can exert anti-tumoral effects in breast cancer cells. Full article

Background: Mesenchymal stem cells (MSCs) are a promising tool in regenerative medicine due to their ability to secrete paracrine factors that modulate tissue repair. Extracellular vesicles (EVs) released by MSCs contain bioactive molecules (e.g., mRNAs, miRNAs, proteins) and play a key role in intercellular communication. Methods: This study compared the transcriptomic profiles (mRNA and miRNA) of equine MSCs derived from adipose tissue (AT-MSCs), bone marrow (BM-MSCs), and ovarian fibroblasts (as a differentiated control). Additionally, miRNAs present in EVs secreted by these cells were characterized using next-generation sequencing. Results: All cell types met ISCT criteria for MSCs, including CD90 expression, lack of MHC II, trilineage differentiation, and adherence. EVs were isolated using ultracentrifugation and validated with nanoparticle tracking analysis and flow cytometry (CD63, CD81). Differential expression analysis revealed distinct mRNA and miRNA profiles across cell types and their secreted EVs, correlating with tissue origin. BM-MSCs showed unique regulation of genes linked to early development and osteogenesis. EVs contained diverse RNA species, including miRNA, mRNA, lncRNA, rRNA, and others. In total, 227 and 256 mature miRNAs were detected in BM-MSCs and AT-MSCs, respectively, including two novel miRNAs per MSC type. Fibroblasts expressed 209 mature miRNAs, including one novel miRNA also found in MSCs. Compared to fibroblasts, 60 and 92 differentially expressed miRNAs were identified in AT-MSCs and BM-MSCs, respectively. Conclusions: The results indicate that MSC tissue origin influences both transcriptomic profiles and EV miRNA content, which may help to interpret their therapeutic potential. Identifying key mRNAs and miRNAs could aid in future optimizing of MSC-based therapies in horses. Full article

Background/Objectives: Chemotherapy-induced neuropathic pain (CINP) represents a critical challenge in oncology, emerging as a common and debilitating side effect of widely used chemotherapeutic agents, such as paclitaxel (PTX). Current therapeutic interventions and preventive strategies for CINP are largely insufficient, as they fail to address the underlying peripheral nerve damage, highlighting an urgent need for the development of new drugs. This study aimed to investigate the dual-function effects on normal cell protection and tumor suppression of BMX-001, a redox-active manganese metalloporphyrin that has demonstrated antioxidant and anti-inflammatory properties, which offers potential in protecting central nervous system tissues and treating CINP. Methods: This study assessed BMX-001’s different roles in protecting normal cells while acting as a pro-oxidant and pro-inflammatory molecule in cancer cells in vitro. We also evaluated its neuroprotective effect in preclinical PTX-induced CINP models in vivo. Results: Our results showed significant reductions in mechanical and cold allodynia, decreased pro-inflammatory cytokine levels, and restored antioxidant capacity in peripheral nerves and dorsal root ganglia (DRGs) following BMX-001 treatment. Conclusions: Overall, our study highlights the therapeutic potential of BMX-001 to mitigate CINP and enhance anticancer efficiency. Its dual-selective mechanism supports the future clinical investigation of BMX-001 as a novel adjunct to chemotherapeutic regimens. Full article

Reactive molecules, including oxygen and nitrogen species, serve dual roles in human physiology. While they function as essential signaling molecules under normal physiological conditions, they contribute to cellular dysfunction and damage when produced in excess by normal metabolism or in response to stressors. Oxidative/nitrosative stress is a pathological state, resulting from the overproduction of reactive species exceeding the antioxidant capacity of the body, which is implicated in several chronic human diseases. Antioxidant therapies aimed at restoring redox balance and preventing oxidative/nitrosative stress have demonstrated efficacy in preclinical models. However, their clinical applications have met with inconsistent success owing to efficacy, safety, and bioavailability concerns. This summative review analyzes the role of reactive species in human pathophysiology, the mechanisms of action of antioxidant protection, and the challenges that hinder their translation into effective clinical therapies in order to evaluate potential emerging strategies such as targeted delivery systems, precision medicine, and synergistic therapeutic approaches, among others, to overcome current limitations. By integrating recent advances, this review highlights the value of targeting reactive species in the prevention and management of chronic diseases. Full article

Nosocomial infections caused by ESKAPE pathogens represent a significant burden to global health. These pathogens may exhibit multidrug resistance (MDR) mechanisms, of which mechanisms such as efflux pumps and biofilm formation are gaining significant importance. Multidrug resistance mechanisms in ESKAPE pathogens have led to an increase in the effective costs in health care and a higher risk of mortality in hospitalized patients. These pathogens utilize antimicrobial efflux pump mechanisms and bacterial biofilm-forming capabilities to escape the bactericidal action of antimicrobials. ESKAPE bacteria forming colonies demonstrate increased expression of efflux pump-encoding genes. Efflux pumps not only expel antimicrobial agents but also contribute to biofilm formation by bacteria through (1) transport of molecules and transcription factors involved in biofilm quorum sensing, (2) bacterial fimbriae structure transport for biofilm adhesion to surfaces, and (3) regulation of a transmembrane gradient to survive the difficult conditions of biofilm microenvironments. The synergistic role of these mechanisms complicates treatment outcomes. Given the mechanistic link between biofilms and efflux pumps, therapeutic strategies should focus on targeting anti-biofilm mechanisms alongside efflux pump inactivation with efflux pump inhibitors. This review explores the molecular interplay between efflux pumps and biofilm formation, emphasizing potential therapeutic strategies such as efflux pump inhibitors (EPIs) and biofilm-targeting agents. Full article

Polymicrobial biofilms involving fungal and bacterial species are increasingly recognized as contributors to persistent infections, particularly in the oral cavity. Candida albicans and Aggregatibacter actinomycetemcomitans are two commensals that can turn into opportunistic pathogens and are able to form robust biofilms. Objectives: This study aimed to assess the interaction dynamics between these two microorganisms and to evaluate their susceptibility to fluconazole and azithromycin in single- and mixed-species forms. Methods: Biofilm biomass was quantified using crystal violet assays, while biofilm cell viability was assessed through CFU enumeration (biofilm viability assay). To assess the resistance properties of single versus mixed-species coincubations, we applied the antimicrobial susceptibility test (AST) to each drug, and analysed spatial organization with confocal laser scanning microscopy, using PNA-FISH. Results: The results indicated that both species can coexist without significant mutual inhibition. However, a non-reciprocal synergism was also observed, whereby mixed-species biofilm conditions promoted the growth of A. actinomycetemcomitans, while C. albicans growth remained stable. As expected, antimicrobial tolerance was elevated in mixed cultures, likely due to enhanced extracellular matrix production and potential quorum-sensing interactions, contributing to increased resistance against azithromycin and fluconazole. Conclusions: This study provides novel insights into previously rarely explored interactions between C. albicans and A. actinomycetemcomitans. These findings underscore the importance of investigating interspecies interactions within polymicrobial biofilms, as understanding their mechanisms, such as quorum-sensing molecules and metabolic cooperation, can contribute to improved diagnostics and more effective targeted therapeutic strategies against polymicrobial infections. Full article

Background: Antibacterial resistance (ABR) poses a major challenge to global health, with methicillin-resistant Staphylococcus aureus (MRSA) being one of the prominent multidrug-resistant strains. MRSA has developed resistance through the expression of Penicillin-Binding Protein 2a (PBP2a), a key transpeptidase enzyme involved in bacterial cell wall biosynthesis. Objectives: The objective was to design and characterize a novel small-molecule inhibitor targeting PBP2a as a strategy to combat MRSA. Methods: We synthesized a new indole triazole conjugate (ITC) using eco-friendly and click chemistry approaches. In vitro antibacterial tests were performed against a panel of strains to evaluate the ITC antibacterial potential. Further, a series of in silico evaluations like molecular docking, MD simulations, free energy landscape (FEL), and principal component analysis (PCA) using the crystal structure of PBP2a (PDB ID: 4CJN), in order to predict the mechanism of action, binding mode, structural stability, and energetic profile of the 4CJN-ITC complex. Results: The compound ITC exhibited noteworthy antibacterial activity, which effectively inhibited the selected strains. Binding score and energy calculations demonstrated high affinity of ITC for the allosteric site of PBP2a and significant interactions responsible for complex stability during MD simulations. Further, FEL and PCA provided insights into the conformational behavior of ITC. These results gave the structural clues for the inhibitory action of ITC on the PBP2a. Conclusions: The integrated in vitro and in silico studies corroborate the potential of ITC as a promising developmental lead targeting PBP2a in MRSA. This study demonstrates the potential usage of rational drug design approaches in addressing therapeutic needs related to ABR. Full article

The expression of recombinant proteins in heterologous hosts is a common strategy to obtain larger quantities of the “protein of interest” (POI) for scientific, therapeutic or commercial purposes. However, the experimental success of such an approach critically depends on the choice of an appropriate host system to obtain biologically active forms of the POI. The correct folding of the molecule, mediated by disulfide bond formation, is one of the most critical steps in that process. Here we describe the recombinant expression of hirudin, a leech-derived anticoagulant and thrombin inhibitor, in the yeast Komagataella phaffii (formerly known and mentioned throughout this publication as Pichia pastoris) and in two different strains of Escherichia coli, one of them being especially designed for improved disulfide bond formation through expression of a protein disulfide isomerase. Cultivation of the heterologous hosts and expression of hirudin were performed at different temperatures, ranging from 22 to 42 °C for the bacterial strains and from 20 to 30 °C for the yeast strain, respectively. The thrombin-inhibitory potencies of all hirudin preparations were determined using the thrombin time coagulation assay. To our surprise, the hirudin preparations of P. pastoris were considerably less potent as thrombin inhibitors than the respective preparations of both E. coli strains, indicating that a eukaryotic background is not per se a better choice for the expression of a biologically active eukaryotic protein. The hirudin preparations of both E. coli strains exhibited comparable high thrombin-inhibitory potencies when the strains were cultivated at their respective optimal temperatures, whereas lower or higher cultivation temperatures reduced the inhibitory potencies. Full article

Long non-coding RNAs (lncRNAs) interact with a variety of biomolecules, including DNA, mRNAs, microRNA, and proteins, to regulate various cellular processes. Recently, their interactions with lipids have gained increasing attention as an emerging research area. Both lipids and lncRNAs play central roles in cellular regulation, and growing evidence reveals a complex interplay between these molecules. These interactions contribute to key biological functions, such as cancer progression, lipid droplet transport, autophagy, liquid−liquid phase separation, and the formation of organelles without membranes. Understanding the lipid−lncRNA interface opens new avenues for unraveling cellular regulation and disease mechanisms, holding great potential not only for elucidating the fundamental aspects of cellular biology but also for identifying innovative therapeutic targets for metabolic disorders and cancer. This review highlights the biological relevance of lipid–lncRNA interactions by exploring their roles in cellular organization, regulation, and diseases, including metabolic and cancer-related disorders. Full article

High-mobility group box 1 (HMGB1) is a nuclear protein that can interact with a transmembrane cell surface receptor for advanced glycation end products (RAGEs) and mediates the inflammatory pathways that lead to various pathological conditions like cancer, diabetes, cardiovascular diseases, and neurodegenerative disorders. Blocking the HMGB1/RAGE axis using various small synthetic or natural molecules has been proven to be an effective therapeutic approach to treating these inflammatory conditions. However, the low water solubility of these pharmacoactive molecules limits their clinical use. Pharmaceutically active molecules with low solubility and bioavailability in vivo convey a higher risk of failure for drug development and drug innovation. The pharmacokinetic and pharmacodynamics parameters of these compounds are majorly affected by their solubility. Enhancement of the bioavailability and solubility of drugs is a significant challenge in the area of pharmaceutical formulations. This review mainly describes various technologies utilized to improve the bioavailability of synthetic or natural molecules which have been particularly used in various inflammatory conditions acting specifically through the HMGB1/RAGE pathway. Full article

Background/Objectives: Cancer suffers from unresolved therapeutic challenges owing to the lack of targeted therapies and heightened recurrence risk. This study aimed to investigate the new series of hydroxamate by structurally modifying the pharmacophore of vorinostat. Methods: The present work involves the synthesis of 15 differently substituted 2H-1,2,3-triazole-based hydroxamide analogs by employing triazole ring as a cap with varied linker fragments. The compounds were evaluated for their anticancer effect, especially their anti-breast cancer response. Molecular docking and molecular dynamics simulations were conducted to examine binding interactions. Results: Results indicated that among all synthesized hybrids, the molecule VI(i) inhibits the growth of MCF-7 and A-549 cells (GI₅₀ < 10 μg/mL) in an antiproliferative assay. Compound VI(i) was also tested for cytotoxic activity by employing an MTT assay against A549, MCF-7, and MDA-MB-231 cell lines, and the findings indicate its potent anticancer response, especially against MCF-7 cells with IC₅₀ of 60 µg/mL. However, it experiences minimal toxicity towards the normal cell line (HEK-293). Mechanistic studies revealed a dual-pathway activation: first, apoptosis (17.18% of early and 10.22% of late apoptotic cells by annexin V/PI analysis); second, cell cycle arrest at the S and G2/M phases. It also promotes ROS generation in a concentration-dependent manner. The HDAC–inhibitory assay, extended in silico molecular docking, and MD simulation experiments further validated its significant binding affinity towards HDAC 1 and 6 isoforms. DFT and ADMET screening further support the biological proclivity of the title compounds. The notable biological contribution of VI(i) highlights it as a potential candidate, especially against breast cancer cells. Full article

Endometriosis is a disease characterized by the presence of endometrial glands and stroma outside of the uterine corpus, often clinically presenting with pain and/or infertility. Ectopic lesions exhibit features characteristic of epithelial-to-mesenchymal transition (EMT), a process in which epithelial cells lose polarity and acquire mesenchymal traits, including migratory and invasive capabilities. During the process of EMT, epithelial traits are downregulated, while mesenchymal traits are acquired, with cells developing migratory ability, increasing proliferation, and resistance to apoptosis. EMT is promoted by exposure to hypoxia and stimulation by transforming growth factor-β (TGF-β), platelet-derived growth factor (PDGF), and estradiol. Signaling pathways that promote EMT are activated in most ectopic lesions and involve transcription factors such as Snail, Slug, ZEB-1/2, and TWIST-1/2. EMT-specific molecules present in the serum of women with endometriosis appear to have diagnostic potential. Strategies targeting EMT in animal models of endometriosis have demonstrated regression of ectopic lesions, opening the door for novel therapeutic approaches. This review summarizes the current understanding of the role of EMT in endometriosis and highlights potential targets for EMT-related diagnosis and therapeutic interventions. Full article