Search Results (1,648)

Copper is an essential trace element required for numerous enzymatic processes in the brain, including mitochondrial metabolism, antioxidant defense, and gene expression regulation. Recent studies have further implicated copper in a newly defined form of regulated cell death termed cuproptosis, providing a mechanistic framework for copper-dependent cytotoxicity. Increasing evidence indicates that copper dyshomeostasis is a common feature of major neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS), where it is associated with protein misfolding, redox imbalance, and neuronal vulnerability. Nevertheless, the mechanistic link between copper dysregulation and neuronal cell death remains incompletely defined. In this review, we systematically summarize the molecular mechanisms governing copper homeostasis and intracellular copper trafficking, while providing a timely, updated, and in-depth overview of the mechanistic basis and emerging biology of cuproptosis. We further comprehensively evaluate the current evidence linking copper dysregulation and cuproptosis-related pathways to neurodegenerative diseases, with particular emphasis on distinguishing mechanistic causation from pathological correlation. Importantly, we discuss current therapeutic strategies and emerging clinical efforts targeting copper metabolism, while highlighting the major challenges in defining the pathological significance and mechanistic contribution of cuproptosis in neurodegenerative diseases. Collectively, this review provides an updated framework for understanding the pathological significance and translational potential of cuproptosis in neurodegenerative diseases. Full article

Glycosylation is the most common post-translational modification in the human proteome, with over half of all human proteins bearing covalently attached glycans. These glycan structures direct protein folding through ER quality control machinery, shield polypeptides from proteolytic degradation, regulate circulatory half-life via the asialoglycoprotein receptor, and serve as molecular signals for immune recognition and intracellular trafficking. For biopharmaceuticals, which constitute a rapidly growing share of approved drugs, glycan profiles are critical quality attributes that directly determine clinical efficacy and safety. Yet achieving the correct glycosylation on a therapeutic protein remains one of the field’s central challenges, as glycan biosynthesis is non-template-driven and highly sensitive to expression system and manufacturing conditions. This review connects the biological functions of glycosylation to the practical strategies of glycoengineering, examining how sequence design, expression system selection, and downstream enzymatic remodeling are used to optimize therapeutic glycoproteins. Clinical case studies spanning monoclonal antibodies, cytokines, and enzyme replacement therapies illustrate how glycan engineering translates into improved patient outcomes. We conclude by surveying emerging technologies poised to make precisely glycosylated therapeutics more accessible. Full article

Collapsin Response Mediator Protein 2 (CRMP2) has emerged as a central node in the pathogenesis of chronic pain, functioning as a multimodal ‘molecular switch’ that regulates microtubule dynamics, ion channel trafficking, and synaptic plasticity. The dysregulation of CRMP2, particularly through aberrant post-translational modifications (PTMs) such as phosphorylation and SUMOylation, is a critical driver of both peripheral and central sensitization. This review systematically examines the structure, regulation, and multifaceted roles of CRMP2 in pain signaling pathways. We then critically evaluate a spectrum of CRMP2-targeted therapeutic strategies, including small-molecule inhibitors, peptide-based agents, and gene silencing, highlighting their promising preclinical efficacy and safety profiles. Despite challenges in targeting specificity and central nervous system delivery, we posit that innovations in delivery systems, precision medicine, and AI-assisted drug design will catalyze the clinical translation of CRMP2-based, non-opioid analgesics, offering a paradigm shift in chronic pain management. Full article

The vascular endothelial glycocalyx (EGX) is a gel-like, negatively charged mesh of membrane-bound proteoglycans, glycosaminoglycans, glycoproteins and adsorbed plasma proteins that covers the luminal surface of the endothelium and orchestrates vascular homeostasis through regulation of permeability, leukocyte trafficking, mechanotransduction and anti-thrombotic signalling. Progressive thinning, heterogeneous remodelling and accelerated shedding of the EGX are now recognised as hallmarks of vascular ageing and early drivers of age-related cardiovascular disease. Here, we synthesise current evidence linking EGX integrity to biological ageing, with emphasis on age-dependent remodelling of heparan-sulfate proteoglycans, endothelial progenitor-cell dysfunction, and the heightened susceptibility of the aged EGX to oxidative, inflammatory and infectious insults. We discuss signalling pathways driving EGX shedding—including the IQGAP1/PAR1-2/PI3K/Akt axis—and clinical correlates such as vulnerable coronary plaque in older patients with coronary artery disease and microvascular endotheliopathy in severe COVID-19. Finally, we review emerging anti-ageing strategies targeting the EGX, including direct oral anticoagulants, glycocalyx-mimetic and nitric-oxide-releasing biomaterials, bioinspired antithrombogenic surfaces and microbiome-based modulation, and consider their translational potential for extending cardiovascular healthspan. Full article

Glutamine-Fructose-6-Phosphate Transaminase 1 (GFPT1), the rate-limiting enzyme of the hexosamine biosynthetic pathway (HBP), provides the UDP-N-acetylglucosamine (UDP-GlcNAc) required for protein glycosylation. Biallelic mutations in GFPT1 cause congenital myasthenic syndromes (GFPT1-CMS), yet the molecular mechanisms linking impaired glycosylation to skeletal muscle dysfunction remain incompletely understood. Here, we combine cellular models of inducible Gfpt1 knockdown and a skeletal muscle-specific Gfpt1 knockout mouse (Gfpt1^Tm1d/Tm1d) with whole-cell proteomics, immunoblot studies and secretomics to define glycosylation-dependent defects in intracellular trafficking, ER stress signaling and autophagy. Global proteomic profiling of Gfpt1-deficient myoblasts revealed marked downregulation of protein trafficking pathways and impaired secretion of key muscle cargo proteins, including serglycin (Srgn). Loss of GFPT1 reduced both high-molecular-weight glycosylated serglycin and its core protein, accompanied by intracellular retention and decreased secretion. These trafficking defects coincide with robust activation of the unfolded protein response (UPR), evidenced by increased Xbp1 expression and accumulation of spliced Xbp1s across pharmacologic, cellular, and mouse models of GFPT1 deficiency. Converging evidence from proteomics, immunoblotting, and immunofluorescence demonstrated impaired autophagy, including increased LC3-II accumulation, elevated p62/Sqstm1 levels, and enhanced p62-positive puncta in both Gfpt1-deficient C2C12 myoblasts and skeletal muscle. Soluble/insoluble fractionation further confirmed p62 accumulation, indicating defective autophagic flux and buildup of aggregated cargo. Together, these findings identify a glycosylation-dependent failure in protein trafficking that triggers ER stress, UPR activation, and autophagy impairment in Gfpt1-deficient skeletal muscle. This mechanistic cascade provides a unifying explanation for muscle pathology in GFPT1-CMS and suggests that restoring glycosylation or improving proteostasis may represent viable therapeutic approaches. Full article

Vacuolar Protein Sorting 29 (VPS29) is a highly conserved subunit of the retromer complex, which mediates retrograde transport from endosomes to the Golgi apparatus and plays a critical role in membrane trafficking, protein recycling, and organelle biogenesis. In Plasmodium falciparum, the retromer has been implicated in the formation of apical organelles essential for parasite invasion and replication. In this study, we investigated naturally acquired antibody responses to P. falciparum VPS29 (PfVPS29) and the genetic diversity of the vps29 gene in isolates from three malaria-endemic areas of the Brazilian Amazon. Naturally acquired responses to PfVPS29 were evaluated by ELISA in 533 individuals, and genetic diversity was assessed in 62 P. falciparum isolates. Only 17% of participants displayed IgG reactivity, whereas 73.5% showed IgM responses, indicating limited IgG acquisition but a predominant IgM profile associated with recent or ongoing exposure. IgG subclass analysis revealed a predominance of cytophilic IgG1 and IgG3 among responders. IgM responses were significantly boosted during P. falciparum infection. Sequence analysis revealed no polymorphisms among Brazilian isolates, and comparison with global datasets confirmed the high conservation of the PfVPS29 coding sequence. Together, these findings show that PfVPS29 is a highly conserved intracellular protein that elicits an atypical humoral response dominated by IgM, with limited class switching to IgG, like other conserved or repetitive malaria antigens. These results highlight PfVPS29 as an example of a conserved intracellular antigen that induces non-classical humoral responses in naturally exposed populations. Full article

Virus infection requires coordinated activation of pathogen-sensing, innate immune, and cellular stress response pathways to mount an effective antiviral defense. Recognition of nucleic acid pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs) initiates signaling cascades that drive the production of type I interferons (IFNs) and proinflammatory cytokines. These responses are often accompanied by the activation of integrated stress response pathways that help optimize host defense. Cytosolic double-stranded dsDNA, generated during viral infection or released from damaged mitochondria, is sensed by cyclic GMP-AMP synthase (cGAS), which generates 2′3′-cGAMP to activate stimulator of interferon genes (STING). Activated STING translocates from the endoplasmic reticulum to the Golgi, where it drives TBK1-dependent IFN and cytokine production. Previous reports show that cGAS activity is enhanced by Ras-GAP SH3 domain binding protein 1 (G3BP1), a key nucleator of stress granules (SGs), independent of its role in SG assembly. Here, we identify a non-canonical role of G3BP1 as a regulator of DNA sensing responses at multiple levels, including STING intracellular trafficking, in addition to potentiating cGAS activity. Loss of G3BP1 impaired STING-dependent IFN and cytokine responses to HSV-1 infection and viral DNA. G3BP1-deficient cells showed reduced cGAMP-induced STING translocation to the Golgi, induction of type I IFN and proinflammatory cytokines, and activation of the ER stress kinase PERK and stress granule formation. Together, these findings demonstrate G3BP1-STING as a node linking DNA sensing, innate immunity, and stress signaling with broad implications for antiviral defense and diseases characterized by aberrant DNA sensing and stress responses, including neurodegeneration, fibrosis, and autoimmunity. Full article

Potassium (K⁺) channels have been frequently linked to cancer progression; however, their contribution varies across tumour types and experimental models. This heterogeneity indicates that gene-level characteristics such as expression, co-expression, or mutational status are inadequate for explaining channel involvement in oncogenic signalling. Here, we performed a cross-study comparison of experimentally validated K⁺ channel interactomes, we show that K⁺ channel regulation is highly context-dependent and does not exhibit conserved pan-cancer signatures. By directly comparing proximity-labeling and affinity-purification datasets across different K⁺ channel families, we identify a limited number of recurrent organizational architectures rather than universal signalling modules. KCa3.1 (encoded by KCNN4), Kir2.1 (KCNJ2), and TASK-1 (KCNK3) assemble signalling-permissive interactomes integrating adhesion complexes, junctional scaffolds, vesicular trafficking pathways, and receptor-associated signalling nodes. In contrast, Kv11.1 (encoded by KCNH2) displays an interactome predominantly enriched for proteostasis and endoplasmic reticulum–associated components, indicating a proteostasis-centered organizational profile with comparatively limited signalling integration. Kv1.3 (encoded by KCNA3), instead, consistently associates with mitochondrial and metabolism-linked proteins and functionally connects metabolic state to downstream transcriptional regulators, rather than regulating its own transcription. Higher-order intersection and pathway-specific analyses indicate that functional convergence across the above channels emerges from shared architectural principles rather than extensive molecular overlap. In conclusion, this study identifies interactome architecture as a central organizational level for understanding K⁺ channel function in cancer. The integration of pan-cancer gene-level analyses with systematic comparison of interaction architectures offers a coherent framework for interpreting the functional heterogeneity observed across channels, families, and tumor contexts. This perspective suggests that therapeutic strategies may benefit from targeting channel-centered network architectures rather than isolated channels alone, highlighting ion channels as structural components of broader signalling systems rather than solely bioelectrical regulators. Full article

Theranostics is a novel approach that integrates diagnostic and therapeutic efficacy on a single platform, holding great promise for precision medicine by enabling real-time monitoring of disease progression and therapeutic response. Despite significant advances, the successful development and delivery of theranostic systems are critically limited by multiple biological barriers present at systemic, tissue, cellular, anatomical, and immunological levels. These barriers restrict bioavailability, target accessibility, and therapeutic efficacy, while often increasing off-target accumulation and adverse effects. This review provides a comprehensive overview of the major biological barriers encountered in theranostic development, including physiological barriers such as plasma protein binding, renal clearance, and hepatic metabolism; anatomical barriers like endothelial linings, the blood–brain barrier (BBB), and the tumor microenvironment; cellular barriers involving membrane permeability, intracellular trafficking, and endo-lysosomal entrapment; and immunological barriers such as immune recognition, inflammatory responses, and complement activation. Special emphasis is placed on the BBB, highlighting its structural complexity, transport mechanisms, and strategies such as molecular Trojan-horse technology, receptor-mediated and adsorptive-mediated transcytosis, and nanocarrier-based approaches to enhance central nervous system delivery. The review further discusses targeted delivery challenges, including receptor heterogeneity and multidrug resistance, and critically evaluates current strategies to overcome these barriers through surface functionalization, stimuli-responsive systems, biomimetic carriers, and controlled-release mechanisms. Finally, recent advances, clinical challenges, and future perspectives—including personalized theranostics, artificial intelligence—assisted design, and next-generation barrier-penetrating systems—are explored. Overall, this review aims to provide a structured understanding of biological barriers in theranostics and highlight innovative approaches to improve their translational potential. Full article

Artificial intelligence (AI) is increasingly influencing nanopharmaceutical development by supporting the transition from empirical formulation screening toward predictive, data-driven, and translationally oriented design. Nanocarrier-based therapeutics are governed by nonlinear relationships among material composition, physicochemical attributes, manufacturing parameters, biological identity, pharmacokinetics, toxicity, and therapeutic performance. In this review, we examine how AI can contribute to nanopharmaceutical development from predictive formulation design to clinical translation. We synthesize current applications of machine learning, deep learning, physics-informed modeling, hybrid mechanistic–AI approaches, and automated optimization workflows, with emphasis on critical quality attribute modeling, multi-objective optimization, design of experiments, quality-by-design, process analytical technology, digital twins, and continuous manufacturing. We also discuss applications involving nano–bio interactions, pharmacokinetics, toxicity, immunogenicity, and precision nanomedicine. AI-based approaches can support rational nanocarrier design, identify nonlinear formulation–property relationships, guide optimization, improve process understanding, and integrate heterogeneous experimental, biological, and manufacturing datasets across diverse nanopharmaceutical platforms. These methods are particularly relevant for modeling protein corona formation, cellular uptake, intracellular trafficking, biodistribution, pharmacokinetics, toxicity, immunogenicity, and patient-specific responses. However, translational implementation remains limited by fragmented datasets, inconsistent reporting standards, limited interpretability, insufficient external validation, uncertain predictions, poorly defined applicability domains, and evolving regulatory expectations for adaptive computational models. Overall, AI should be viewed not only as an optimization tool, but also as a translational framework connecting formulation science, biological prediction, manufacturing control, and clinical implementation. Future progress will depend on standardized data infrastructures, explainable and externally validated models, uncertainty quantification, applicability-domain definition, hybrid mechanistic–AI frameworks, regulatory-ready documentation, and clinically relevant case studies. Full article

The Popeye domain-containing protein 1 (Popdc1), also known as Bves, plays a crucial role in maintaining skeletal muscle homeostasis, with its variants leading to limb–girdle muscular dystrophy type R25. Skeletal muscles of patients with the homozygous missense variant of Bves exhibit impaired membrane trafficking, while skeletal muscle fibers in bves^S191F homozygous mutant zebrafish are significantly reduced and disorganized. However, the mechanism by which the absence of bves induces skeletal muscle atrophy remains unclear. In this study, we discovered a novel mechanism whereby bves deficiency drives skeletal muscle atrophy by disrupting mitochondrial structure and function. Our findings indicate that bves knockout leads to a significant decrease in zebrafish’s ability to swim, atrophy of skeletal muscle tissue, loss of cell membrane localization signals, and abnormalities in mitochondrial structure and function. After an 8-week intervention of regular aerobic exercise, the symptoms of skeletal muscle atrophy in bves knockout zebrafish were significantly alleviated, and the expression levels of genes and proteins related to mitochondrial were effectively rescued. These findings establish a connection between bves deficiency-induced disruption of mitochondrial structure and function and the onset and progression of skeletal muscle tissue atrophy symptoms, thereby laying a molecular foundation for exercise rehabilitation strategies in atrophic myopathy. Full article

Atherosclerosis (AS) is the primary underlying cause of cardiovascular and cerebrovascular diseases. The occurrence and development of AS are closely related to lipid deposition, chronic inflammation, phenotypic modulation of vascular smooth muscle cells (VSMCs), and extracellular matrix (ECM) remodeling. Numerous studies indicate that low-density lipoprotein receptor-associated protein 1 (LRP1), as a multifunctional receptor, contributes to vascular homeostasis in AS and vascular remodeling by regulating lipid handling, inflammatory responses, transforming growth factor beta (TGFβ) signaling, and platelet-derived growth factor receptor beta (PDGFRβ) trafficking. Rather than treating the LRP1-TGFβ-PDGFRβ relationship as a fully established linear pathway, this review distinguishes demonstrated mechanisms from inferred cross-talk and proposes an integrated, cell- and stage-dependent regulatory model. This article systematically elaborates on the structure and function of LRP1; LRP1-mediated regulation of TGFβ and PDGFRβ in AS and vascular remodeling; the possible relationship among LRP1, TGFβ, and PDGFRβ; and cell-specific effects in VSMCs, macrophages, endothelial cells, and pericytes. Meanwhile, this article summarizes potential translational strategies such as lipid-lowering, anti-inflammatory therapy, PDGFRβ inhibitor repositioning, TGFβ pathway modulation, biomarker-based stratification, and LRP1-targeted delivery. A deeper understanding of the cell-specificity and stage-dependence of the LRP1-TGFβ-PDGFRβ signaling network may help elucidate the progression mechanism of AS and provide new ideas for risk stratification and precise intervention. Full article

Background: Early endolysosomal and autophagic defects are among the earliest cellular alterations observed in Alzheimer’s disease (AD). However, the molecular mechanisms linking amyloid precursor protein (APP) metabolism to vesicle trafficking dysfunction remain incompletely understood. The APP-derived fragment C99 has emerged as a potential upstream mediator of intracellular toxicity, but its impact on organelle homeostasis and its modulation by metabolic interventions remain unclear. Methods: To investigate these mechanisms, we expressed human C99 in Drosophila neurons and examined intracellular pathology using ultrastructural analysis, fluorescent reporters of autophagy and mitochondrial turnover, and proteomic interactome mapping. The effects of the ketone body β-hydroxybutyrate (BHB) were evaluated to assess the impact of metabolic intervention. Results: Neuronal C99 expression induced pronounced vesicular abnormalities, impaired autophagic turnover, and disrupted mitochondrial quality control. Transmission electron microscopy revealed extensive accumulation of enlarged vesicular compartments, accompanied by reduced mitochondrial turnover and accumulation of aged mitochondria. BHB treatment restored autophagic cargo clearance, improved mitochondrial turnover, and normalized vesicular ultrastructure. These protective effects required neuronal ketone transport, indicating a neuron-intrinsic metabolic mechanism. Proteomic analysis of the C99-associated interactome revealed that ketone treatment remodels networks enriched for vesicle trafficking and proteostasis pathways. Network prioritization identified the retromer component VPS35 as a candidate regulatory hub. Functional analyses demonstrated that depletion of VPS35 abolished the BHB-dependent restoration of autophagy, mitochondrial turnover, and vesicle morphology. Conclusions: Ketone treatment restores mitochondrial quality control and autophagic homeostasis through a VPS35-dependent mechanism in C99-induced neurodegeneration. These findings provide mechanistic insight into how metabolic interventions may restore intracellular homeostasis in Alzheimer’s disease. Full article

Adult bone marrow-derived mesenchymal stem cells (BMSCs) are multipotent progenitors capable of differentiating into diverse cell lineages, including osteogenic, chondrogenic, adipogenic, and neuronal lineages. In BMSCs, intracellular glutathione (GSH) is a critical determinant of stemness maintenance and differentiation outcomes. However, how intracellular GSH homeostasis is regulated during BMSC-to-neuron differentiation remains unclear. In neurons, GSH synthesis critically depends on cysteine uptake mediated by the excitatory amino acid carrier 1 (EAAC1). Here, we investigated the expression, subcellular localization, and functional contribution of EAAC1 and its regulatory protein, glutamate transporter-associated protein 3-18 (GTRAP3-18) in mouse BMSCs and neuron-like BMSCs generated by Notch intracellular domain-based induction (NICD-3F BMSCs). BMSCs exhibited higher intracellular GSH levels than NICD-3F BMSCs, despite comparable levels of EAAC1 protein. In contrast, EAAC1-dependent cysteine uptake and plasma membrane localization of EAAC1 were markedly reduced in BMSCs, indicating differentiation-dependent regulation of EAAC1 trafficking. Treatment with the xCT inhibitor erastin reduced intracellular GSH levels in both BMSCs and NICD-3F BMSCs. GTRAP3-18 expression was high in BMSCs and significantly reduced in NICD-3F BMSCs. Notably, GTRAP3-18 knockout decreased intracellular GSH levels in BMSCs without altering total EAAC1 protein or intracellular cysteine levels, whereas in NICD-3F BMSCs, both GSH and EAAC1 protein levels were increased. These findings demonstrate lineage-dependent divergence in GSH regulatory mechanisms and reveal previously unrecognized functions of GTRAP3-18 in redox control during stem–to–neuron differentiation. Full article

Background: Although prolonged inflammatory symptoms are an infrequent and problematic adverse effect of vaccination that can occur in some people, the transient activation of acute phase reactants (APRs) is expected with adjuvanted vaccines and helps to potentiate immune responses. Methods: This experiment examined the association between vaccine reactogenicity and immunogenicity in monkeys immunized with an adjuvanted recombinant protein including a receptor binding domain–human IgG1-Fc fusion protein (RBD-Fc) sequenced from the ancestral Wuhan strain of SARS-CoV-2. The acute inflammatory reaction to immunization was assessed by determining the decline in serum iron levels at 24 h and the increase in the neutrophil-to-lymphocyte ratio (NLR) as the adherent neutrophil pool trafficked into circulation. Results: Robust primary and secondary antibody responses were elicited. Larger decreases in serum iron and higher NLRs were associated with a stronger inhibition of RBD binding with angiotensin-converting enzyme (ACE2) when five early viral variants of SARS-CoV-2 were tested, including Wuhan, Alpha, Beta, Gamma and Delta. Inhibition of ACE2-RBD binding was less evident when the Omicron variant was tested. Individual variation in the APR was also predictive of the persistence of cell-mediated immunity based on the number of interferon-expressing mononuclear cells activated by viral antigen in ELISpot assays. Conclusions: Rapid antibody responses to primary immunization and large secondary responses to booster immunizations were elicited by this adjuvanted recombinant RBD-Fc vaccine, and our analysis affirmed the view that a transient APR can enhance antibody binding with antigen proteins. Full article