Search Results (2,578)

This study presents a comparative in vitro evaluation of 24 natural sesquiterpene γ-lactones and selected semisynthetic derivatives against three trypanosomatid parasites responsible for neglected tropical diseases: Trypanosoma brucei brucei, Trypanosoma cruzi, and Leishmania amazonensis. The compounds were screened for antiparasitic activity across different parasite life stages, and their cytotoxicity was assessed in mammalian cells. Several compounds demonstrated high inhibitory activity (>95%) at 10 µg/mL, including estafiatin (1), grossheimin (4), cynaropicrin (5), argolide (2) derivatives, and arglabin (23). However, a marked decrease in activity was observed at lower concentrations and in intracellular parasite models, particularly for T. cruzi and L. amazonensis amastigotes. Among the tested compounds, dihydroargolide (3) and pulchellin C (19) exhibited comparatively lower cytotoxicity and were further evaluated, yielding IC₅₀ values of 10.51 ± 1.72 µg/mL and 2.51 ± 1.13 µg/mL against T. b. brucei, respectively. Against L. amazonensis promastigotes, estafiatin (1), 8α-chloroacetoxygrossheimin (12), and arglabin (23) showed IC₅₀ values of 0.16 ± 0.13, 0.35 ± 0.18, and 0.58 ± 0.11 µg/mL, respectively, although their selectivity indices remained limited. Comparative analysis of the dataset indicates that specific structural elements, such as the α-methylene-γ-lactone moiety and selected substituents (e.g., epoxy and acetyl groups), may influence antiparasitic activity in a species-dependent manner. At the same time, the generally low selectivity indices and reduced activity in intracellular models highlight important limitations of these compounds as direct drug leads. Overall, this work provides a systematic comparative dataset and identifies preliminary structure–activity trends that may guide further chemical optimization of sesquiterpene γ-lactones as antiparasitic hit compounds. Full article

The dystrophin–glycoprotein complex (DGC) is a structural and signaling network of cardiac muscle. It connects the extracellular matrix to the intracellular cytoskeleton. Dystroglycan, a component of the DGC, plays an essential role in maintaining the integrity of the sarcolemma of cardiac muscle. It contributes to sarcolemma stability, force transmission, mechanotransduction, calcium homeostasis, and cardiomyocyte survival. While the role of dystroglycan signaling is well established in many inherited disorders such as Duchenne muscular dystrophy, it is less studied in acquired heart failure with reduced ejection fraction (HFrEF). Emerging evidence suggests that dystroglycan remodeling may also occur in HFrEF. This review critically analyzes dystroglycan signaling in healthy and failing hearts, with particular emphasis on its emerging role in acquired HFrEF, including cardiac remodeling and fibrosis. Full article

Viral infections continue to pose a major global health challenge because of rapid viral evolution, immune escape, and the emergence of novel pathogens. This review examines the biological characteristics, antiviral mechanisms, production strategies, and therapeutic potential of camelid VHH as next-generation antiviral agents. The review synthesizes current evidence on the structural and functional properties of VHH, their methods of generation and engineering, and their applications against a broad range of respiratory and non-respiratory viruses. Camelid VHH nanobodies exhibit high specificity and affinity, exceptional physicochemical stability, efficient tissue penetration, and the unique ability to recognize conserved and cryptic epitopes that are often inaccessible to conventional antibodies. Engineering approaches, including multivalent, bispecific, Fc-fused, and half-life-extended constructs, further enhance their antiviral potency and pharmacokinetic properties. Evidence from preclinical studies demonstrates potent antiviral activity against multiple viral pathogens through mechanisms that include blocking viral attachment and fusion, inhibiting intracellular replication, targeting conserved viral proteins, and reducing the likelihood of viral escape. The review also highlights emerging advances in recombinant production platforms, artificial intelligence-assisted nanobody design, targeted delivery technologies, and One Health applications. Collectively, the available evidence indicates that camelid VHH represent a highly versatile and adaptable platform for antiviral therapeutics and diagnostics, with considerable potential to support pandemic preparedness and the development of broad-spectrum interventions against current and emerging viral diseases. Full article

Ischemia–reperfusion injury (IRI) is a common form of tissue injury encountered in myocardial infarction, ischemic stroke, solid-organ transplantation, and complex vascular surgery. Timely restoration of blood flow is essential for salvaging ischemic tissues; however, reperfusion itself can induce sterile inflammation and oxidative stress, further compromising microvascular and organ function. Accumulating evidence indicates that alterations in the local microenvironment associated with innate immune responses contribute to this pathological process, with neutrophils representing among the earliest effector cells recruited to injured tissues. In response to danger signals such as damage-associated molecular patterns, neutrophils can release neutrophil extracellular traps (NETs), extracellular web-like structures composed of decondensed chromatin and granular proteins. Extracellular NETs can injure endothelial and parenchymal cells and provide procoagulant scaffolds that contribute to immunothrombosis and local inflammatory responses. Current evidence is derived predominantly from clinical samples and experimental models across different organs. Owing to organ-specific differences in microvascular architecture, cellular composition, and ischemia–reperfusion conditions, the triggers, relative pathological contributions, and responses to NET-targeted interventions are not uniform across tissues. This review first summarizes the intracellular events preceding NET release, the molecular composition of extracellular NETs, and the mechanisms of NET extrusion. We then provide an organ-based synthesis of the local triggers, major injurious effects, and interventional evidence for NETs in the heart, liver, lung, kidney, brain, intestine, limb, and skin, while discussing recurrent pathological features—including microthrombosis, endothelial or barrier injury, and inflammatory amplification—in the context of organ-specific differences and the limitations of the available evidence. In addition, we evaluate therapeutic strategies involving degradation of extracellular NETs and neutralization of their toxic components, inhibition of NET-associated enzymes and upstream signaling pathways, and spatiotemporally targeted delivery, together with the major barriers to clinical translation. Overall, this review provides an organ-structured synthesis of current evidence linking NETs to IRI and offers a framework for understanding their context-dependent pathological roles and for developing organ- and phase-specific therapeutic strategies. Full article

Drug resistance in cancer remains a major barrier to durable therapeutic benefits and limits the effectiveness of chemotherapy, targeted therapy, and combination treatment in multiple malignancies. Increasing evidence indicates that specific kinesin superfamily proteins contribute to tumor adaptation and therapeutic response in a context-dependent manner through their roles in mitotic regulation, intracellular transport, and stress-response pathways. Aberrant expression of multiple kinesin family members has been documented across diverse cancers and is frequently associated with aggressive clinicopathological features, poor prognosis, and resistance to treatment. However, expression alterations alone do not establish functional dependency, and mechanistic validation is required to distinguish true resistance drivers from adaptive tumor states. In this review, we summarize the classification, biological functions, and abnormal expression patterns of kinesins in cancer; discuss the major mechanisms through which they contribute to drug resistance; and examine strategies for targeting kinesins, including natural-product-derived direct inhibitors, small-molecule inhibitor development, rational combination approaches, and structure-guided and computational optimization strategies. We also evaluate the biomarker potential of kinesin dysregulation and the value of advanced preclinical models for mechanistic and translational investigations. Finally, we highlight the major challenges that hinder clinical translation, including target specificity, compensatory resistance, insufficient biomarker validation, and tumor heterogeneity. Future progress will require integration of functional genomics, multiomics profiling, and mechanism-guided therapeutic strategies to determine when kinesin inhibition represents a clinically actionable approach for resistant malignancies. Full article

Background: Cultured primary mouse hepatocytes undergo drastic phenotypic and metabolic reprogramming, while the temporal rules and regulatory machinery of membrane phospholipid remodeling remain elusive. Methods: Relying on a 0–72 h time-series in vitro culture system, this study integrated multi-omics technologies to dissect the temporal dynamics of phospholipid remodeling in hepatocytes. Through phosphatidylethanolamine N-methyltransferase (PEMT) knockout, exogenous PEMT expression, and methionine deprivation, we examined the association of PEMT status and methionine availability with phospholipid remodeling. Results: In vitro cultivation reduces intracellular total phospholipids, phosphatidylcholine (PC) and phosphatidylethanolamine (PE) through three coordinated events: suppressed transcription of phospholipid synthetic genes hinders de novo synthesis, elevated lipid hydrolysis consumes cellular phospholipids, and extracellular phospholipids accumulate in the culture medium from 12 to 48 h. These jointly trigger ordered remodeling of PC/PE balance, acyl chain length and fatty acid unsaturation. PEMT knockout was associated with PE retention without worsening hepatocyte dedifferentiation, PEMT exogenous expression raises PC content and PC/PE ratio yet cannot rescue culture-dominated lipid structural shifts. Methionine depletion depleted cellular methionine, S-adenosylmethionine (SAM) and S-adenosyl-L-homocysteine (SAH), producing selected lipid changes that partially overlapped with lipid phenotypes of PEMT knockout. Conclusion: In short, culture duration was the dominant factor associated with the fundamental phospholipid remodeling trajectory, and PEMT status and methionine availability, were associated with selective differences in lipid composition. Full article

CD97 is an adhesion G-protein-coupled receptor encoded by ADGRE5 that integrates extracellular signals (including cell adhesion, ligand binding, and mechanical stimulation) with intracellular signal transduction. Recent structural studies have further elucidated tethered/intramolecular agonist (TIA)/Stachel recognition and engagement of the seven-transmembrane domain (7TMD), activation-associated 7TMD conformational changes, and G-protein coupling, including the structural basis for the preferential coupling of CD97 to G13. Currently, antibody–drug conjugates (ADCs) targeting CD97 are supported by in vitro proof-of-concept evidence, whereas chimeric antigen receptor (CAR) strategies have shown antitumor activity in animal models of glioblastoma (GBM) and acute myeloid leukemia (AML). Existing research indicates that CD97 is involved in maintaining stem-like states, invasion and metastasis, metabolic adaptation, and stress survival in certain tumors, and its function varies depending on tumor type and cellular environment. Because CD97 is also expressed in normal immune cells and various nonhematopoietic tissues, systemic targeted therapy may be limited by on-target/off-tumor toxicity. This article reviews the latest advances in CD97 structure and signal transduction, and explores its tumor-related functions, biomarker value, evidence for ADC and CAR-related therapies, as well as early exploratory directions involving RNA-mediated downregulation and structure-guided interventions. Full article

In the central nervous system, the neuropeptide oxytocin stimulates neural networks that regulate social behaviors, including social attachment, aggression, and complex social cognition. Perturbations in oxytocin and/or oxytocin receptor expression results in social behavioral deficits and are associated with a number of psychopathologies including autism spectrum disorder, schizophrenia, anxiety, and depression. In rodent models of autism spectrum disorder, oxytocin is effective at improving social behavior. However, limited translatability between animal models and human physiology has hindered successful translation of these findings into human therapeutics. Oxytocin variant-induced cellular signaling pathways and G-protein coupling have largely been investigated in HEK and CHO heterologous expression systems; however, cellular context is crucial, and these profiles likely differ from intact neurons. This project assessed oxytocin variants in in vitro human-derived neuron-like SH-SY5Y cells that endogenously express the oxytocin receptor. Results demonstrated that the naturally occurring oxytocin variants Leu⁸-OT, Pro⁸-OT and Val³-Pro⁸-OT activated intracellular signaling pathways and promoted neuronal differentiation-associated responses, including calcium mobilization, membrane hyperpolarization, and neurite outgrowth in a concentration-dependent manner. Knowledge of how oxytocin variants alter cellular structure and function has the potential to both identify mechanisms that produce social dysfunction and to inform the development of therapeutic agents. Full article

RNA therapeutics offer considerable potential for cancer treatment. Their therapeutic application, however, remains limited by rapid degradation, inefficient cellular uptake, and restricted intracellular release. Extracellular vesicles (EVs) are cell-derived membrane vesicles that have been exploited as promising vehicles for drug delivery due to their high biocompatibility and low immunogenicity, whereas liposomes and lipid nanoparticles provide tunable lipid composition and efficient loading of exogenous nucleic acids. Combining these carriers has led to EV–lipid hybrid systems designed to integrate their complementary properties. This review summarizes recent advances in EV–lipid hybrids for cancer therapy and organizes the reported systems according to their structural architecture and preparation. EV–liposome fusion hybrids, EV–lipid nanoparticle hybrids, and EV membrane-integrated lipid nanocarriers are discussed in relation to their RNA-loading strategies and representative therapeutic designs. The review also examines the key processes involved in functional RNA delivery and summarizes representative applications across different cancer types. Challenges associated with safety evaluation are also discussed, together with future directions for clinical translation. Overall, EV–lipid hybrids represent a promising strategy for RNA-based cancer therapy. Full article

Plants are continuously exposed to volatile organic compounds (VOCs) emitted by neighbors. Although the mechanisms governing VOC uptake and metabolism remain unclear, cytochrome P450 monooxygenases (CYP450s) are thought to participate in the detoxification and metabolic conversion of absorbed VOCs. Data from previously conducted cDNA microarray transcriptomic profiling in potato exposed to French marigold essential oil (FM-EO) was here used to filter differentially expressed sequences, and identified 54 unique CYP450 transcripts. Among the 10 most highly expressed sequences, two CYP81D1-like (81D1-1 and 81D1-2) and one CYP81D11-like (81D11-1) transcripts were found. RT-qPCR confirmed their strong induction within 8 h of volatile exposure. Comprehensive bioinformatics identified the most highly induced 81D1-1 gene as a CYP450 containing a predicted N-terminal hydrophobic signal or membrane-anchor region, the conserved heme-binding signature motif, and regulatory elements associated with oxidative stress responses. The other 81D11-1 gene, exhibiting a comparable expression level, was annotated only as a heme-binding protein but possessed seven distinct cis-regulatory elements, suggesting high transcriptional plasticity. Machine learning predictions assigned the highest interaction probability to (Z)-β-ocimene, whereas structure-based docking yielded the most favorable mean score for piperitone. This study provides the first characterization of the potato CYP450 superfamily in the context of volatile-mediated plant–plant interactions and identifies two CYP81D members as strong candidates for the oxidative metabolism of absorbed VOCs. The results support a proposed detoxification pathway in which CYP81-mediated oxidation precedes glutathione conjugation and intracellular sequestration of VOCs. These candidate genes provide a valuable foundation for future functional studies and may facilitate the development of sustainable crop protection strategies based on volatile-mediated plant defense. Full article

Coronaviruses comprise a diverse group of enveloped, positive-sense single-stranded RNA viruses capable of causing high morbidity in humans and livestock. The repeated emergence of severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and SARS-CoV-2 underscores the critical need for broad-spectrum countermeasures. Mounting evidence demonstrates that successful coronavirus infection depends on the manipulation of host cellular pathways governing translation, metabolism, autophagy, and survival. The mechanistic target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that functions via the mammalian target of rapamycin complex 1 (mTORC1) and complex 2 (mTORC2) to integrate extracellular and intracellular signals. Rather than remaining passive metabolic bystanders, coronaviruses actively exploit and rewrite host PI3K/Akt/mTOR networks to facilitate structural translation, assemble double-membrane replication organelles, suppress autophagic clearance, and reprogram protective innate and adaptive immune landscapes. This review provides a comprehensive synthesis of the molecular mechanisms dictating coronavirus–mTOR interactions across human pathogens and high-impact veterinary models. We detail the clinical consequences of dysregulated mTOR signaling—including immunometabolic perturbations, long-term metabolic memory, and tissue-specific complications—and evaluate the therapeutic potential of allosteric rapalogs, dual ATP-competitive inhibitors, and natural compounds as host-directed platforms designed to complement conventional antiviral regimens and enhance global pandemic preparedness. Full article

The widespread exposure of multidrug-resistant bacterial strains due to excessive use of antibiotics has accelerated the bacteriophage applications as highly specific antibacterial agents competent to target resistant pathogenic Vibrio through receptor-mediated adsorption and lytic infection. Vibrio pathogens are responsible for substantial economic losses, environmental instability, and foodborne infections in humans through contaminated seafood and water. However, the molecular determinants remain incompletely understood, commanding the Vibrio-phage host specificity, host range, and resistance evolution. This review highlights the comprehensive overview of structural, and functional framework of Vibrio surface receptors responsible for phage recognition, including outer membrane vesicles (OMVs), porins, lipopolysaccharides (LPS), capsular polysaccharides (CPS), flagella, and pili along with specialized bacteriophage tail spike proteins known as receptor-binding proteins (RBPs). We also explored the mechanisms against phage-mediated lysis, including receptor modification, intracellular defense systems, physiological remodeling, and structural adaptations that regulate burst size, lysis timing, and resistance evolution with emphasis on significant progress in phage biology and therapeutic development. It is critical to grasp the molecular-level interaction mechanisms due to limited marine phage ecological data, lack of standardized resistance databases, and regulatory constraints. Future perspectives emphasize the engineered phages, multi-omics integration, and artificial intelligence-driven phage design for the sustainable management of Vibriosis and improved aquaculture biosecurity. Full article

Cellular responses depend on the coordinated regulation of receptor activation, trafficking, and signaling across distinct membrane and intracellular compartments. Proteoglycans (PGs), traditionally regarded as structural components of the extracellular matrix and co-receptors, are now emerging as active organizers of receptor dynamics. This review examines the mechanisms through which PGs regulate receptor trafficking and spatial signaling in cancer. Recent studies addressing the roles of proteoglycans in receptor clustering, endocytic pathway selection, intracellular trafficking, recycling, lysosomal degradation, endosomal signaling, exosome biogenesis, and nuclear receptor transport were evaluated, with particular attention to the strength of direct evidence for trafficking. Particular attention was given to the complementary functions of proteoglycan core proteins, glycosaminoglycan chains, and extracellular matrix remodeling in shaping receptor behavior. Current evidence demonstrates that proteoglycans govern multiple stages of receptor biology by controlling ligand presentation, receptor accessibility, membrane organization, intracellular trafficking, and signaling persistence. Individual proteoglycans exert distinct effects on receptor fate, ranging from receptor downregulation and degradation to sustained endosomal signaling and nuclear receptor translocation. Cancer-associated alterations in proteoglycan expression, glycosaminoglycan sulfation, heparanase activity, ectodomain shedding, and glycocalyx organization remodel signaling networks, strengthen communication between tumor and stromal cells, and promote tumor progression, immune modulation, metastasis, and therapeutic resistance. Proteoglycans have emerged as fundamental regulators of receptor trafficking and signaling architecture. Through the integration of extracellular matrix organization with receptor dynamics, they shape the spatial and temporal properties of oncogenic signaling. This conceptual framework broadens our understanding of tumor biology and identifies proteoglycan-dependent regulation of receptor trafficking as a promising avenue for future therapeutic intervention. Full article

Targeted protein degradation (TPD) represents a whole new paradigm in cell-level therapeutic design, with its ability to remove target proteins, normally through the endogenous proteasomal, lysosomal, or autophagic systems, rather than the traditional occupancy-driven inhibition approach. But the clinical efficacy of degraders is becoming more restricted based on delivery rather than efficacy only. Many proteolysis-targeting chimeras and new proximity-inducing systems have low solubility, are impermeable, are pharmacodynamically complicated, lack tissue selectivity, and cannot fully access the intracellular space. Nanomedicine and PD platforms could provide strategies not only to overcome these challenges, but also to provide other advantages, including enhancing exposure to degraders, biodistribution, controlled release, and context-dependent activation. This critical review is an outline of all lipid, polymeric, inorganic, biomimetic, targeted, activatable, and self-assembling delivery systems for TPD. We assess compositional considerations, in vitro and in vivo evidence, challenges for translation, and clinical endpoints required to support delivery-enabled degradation. Trusted TPD therapeutics need to relate different aspects of their design, such as degrader chemistry, carrier structure, disease biology, and pharmacodynamic biomarkers, to one another. Further investigations are needed to establish intact delivery of the degrader to the target, target depletion in relevant tissues, prolonged pharmacodynamics, favorable safety, and compelling therapeutic benefit relative to free degraders or traditional inhibitors. Thus, it is important to view delivery not simply as an additional step during formulation but as a design principle necessary for the reliable clinical outcome of degradation medicine. Full article

Excessive melanin accumulation induced by UV exposure and hormonal changes poses significant challenges to skin health, necessitating safe and effective tyrosinase inhibitors. Pearl and nacre powder have long been utilized in traditional Chinese medicine for skin whitening. Our previous study identified a tyrosinase inhibitory peptide (Ala-His-Tyr-Tyr-Asp) from Pinctada martensii nacre in silico; however, chemical modification strategies for enhancing bioactive peptide efficacy remain underexplored. The present study investigated the structure-activity relationship of NP-TIP-1 (Tyrosinase Inhibitory Peptide of Nacre Powder-1) through three chemical modifications (C-terminal amidation, N-terminal acetylation, and N-terminal palmitoylation). C-terminal amidation significantly improved tyrosinase inhibitory potency, reducing the IC50 value from 2.012 ± 0.088 mM to 0.979 ± 0.028 mM, while retaining thermal stability and copper ion chelating capacity comparable to the native peptide. In B16F10 melanoma cells, NP-TIP-1-NH₂ (C-terminally amidated NP-TIP-1) exhibited no cytotoxicity at concentrations up to 600 μM and concentration-dependently suppressed intracellular tyrosinase activity and melanin content. Mechanistic investigation revealed that NP-TIP-1-NH₂ treatment downregulates the mRNA and protein expression of TYR and TRP-1 without affecting MITF (Microphthalmia-associated Transcription Factor) or TRP-2, suggesting a potential regulatory mechanism independent of MITF-mediated transcriptional control. Non-targeted metabolomics further identified nucleotide metabolism, purine metabolism, and glycine/serine/threonine metabolism as the most significantly perturbed pathways, with cytosine and GMP downregulated while guanosine and guanine were upregulated. This study establishes NP-TIP-1-NH₂ as a promising candidate for multifunctional food preservatives and nutraceuticals, providing a strategic framework for C-terminal amidation as a structure-activity optimization approach for marine-derived anti-melanogenic peptides. Full article