Search Results (130)

Extracellular vesicles (EVs) can disseminate replication-competent viral genomes complexed with selected host proteins, enabling stealth cell-to-cell transfer within lipid membrane-enclosed bubbles. In addition to complementing free-virion spread, EV-associated genomes can be protected from neutralizing antibodies and persist under conditions in which classical virion production decreases. Here, we propose a route-resolved framework in which interconnected cellular secretory pathways, including endoplasmic reticulum (ER) remodeling, multivesicular body (MVB) biogenesis, secretory autophagy, and plasma-membrane budding, jointly generate EV heterogeneity and create discrete opportunities for the capture, protection, and export of infectious cargo. We highlight reticulon-3 (RTN3), an ER-shaping protein, as an upstream regulator that can couple infection-induced ER microdomains to endosomal docking and to autophagy-linked trafficking decisions that bias intermediates toward secretion rather than degradation. Supporting this view, transmission electron microscopy of dengue virus-infected cells reveals extensive vesicular remodeling, including irregular MVBs adjacent to the plasma membrane and autophagosome-like double-membrane structures, consistent with altered vesicular routing following RTN3 perturbation. Collectively, these route-resolved, spatially organized spatio-organelle changes support a pathomechanistic model in which RTN3-mediated ER remodeling reshapes ER-endosome-autophagy trafficking interfaces, creating regulated decision points that can be leveraged to stratify infectious EV subsets (with infectivity-linked single-vesicle and quantitative proteomics approaches) and to inform host-directed strategies that curb non-lytic viral dissemination. Full article

Plant-derived exosomes (PDEs) are gaining attention owing to their key implications in cross-kingdom communication, facilitating bioactive entities among plants and animals. PDEs are tiny nanoscale vesicles generally comprised of RNAs, proteins, and secondary metabolites and are involved in the regulation of physiological processes (immune modulation, cell regeneration, and stress response). An important feature of PDEs is to enable cross-kingdom regulation in skin wound repair. This is because PDEs can modulate several signaling pathways (PI3K-Akt, TGF-β, and mitogen-activated protein kinase) that further direct inflammatory, cell migratory, angiogenic, and extracellular matrix remodeling. Key features of PDEs, including modest immunogenicity, easy crossing of biological barriers, and natural biocompatibility, make them novel alternatives to synthetic wound-healing agents. Therefore, this review disparagingly examines the biogenesis, molecular composition, and diversified biological functions of PDEs, particularly with reference to potential implications in wound healing and overall skin health. The current challenges pertaining to PDE isolation, scalability, and bioavailability and regulatory hurdles for their clinical translation were also explored. In addition, the epigenetic effects of PDEs on human skin cells and wound healing are explained in detail. Finally, this review presents a comprehensive investigation of PDEs in skin wound repair, identifies research gaps, and outlines future directions for dermatological applications. Full article

Plant-derived extracellular vesicles (PDEVs) are nanoscale carriers produced through conserved plant mechanisms, including multivesicular body (MVB) formation and consequent extracellular vesicle release. MVBs are formed through repeated rounds of intracellular vesicles’ fusion, thus leading to the incorporation into PDEVs of lipids, proteins, miRNAs, nucleic acids, and secondary metabolites, derived from different cellular compartments. PDEVs possess a bilayer lipid membrane, which protects their cargo from degradation and facilitates membrane–membrane fusion with target cells. Ayurvedic medicinal plants are renowned for their extensive phytochemical diversity and enduring efficacy in addressing inflammation, infections, metabolic disorders, cancer, and neurodegeneration. However, the clinical translation of traditional herbal preparation is severely bottlenecked by batch-to-batch variability, restricted compound bioavailability, mechanistic uncertainties, and limitations of conventional large-scale extractions. This perspective research study critically proposes PDEVs as an innovative interpretation for Ayurvedic medicinal plants utilization. We identify and evaluate medicinal plants with established therapeutic characteristics that remain unexamined in PDEV research, hence presenting compelling opportunities for future investigation. By establishing a synergistic bridge between ancient Ayurvedic knowledge and modern nanomedicine, this perspective provides a methodological roadmap to guide health-efficient plant selection and accelerate translational research in next-generation therapeutics. Full article

The field of extracellular vesicle (EV) research offers a compelling example of a biological concept refined through continuous methodological innovation. This review traces the historical trajectory of the discipline chronologically, beginning with early observations in haemostasis, from Malpighi’s descriptions of blood clots and Chargaff and West’s identification of a procoagulant sedimentable plasma fraction, to Wolf’s “platelet dust,” Crawford’s microparticles characterised by electron microscopy, and the seminal work by Stahl and Johnstone demonstrating regulated vesicle biogenesis during reticulocyte maturation via multivesicular bodies. We highlight a pivotal conceptual shift, from viewing EVs as cellular debris to recognising them as regulated “communicasomes,” catalysed by Raposo’s discovery of antigen-presenting exosomes and subsequent evidence for EV-mediated transfer of functional receptors and nucleic acids, including the influential and sometimes debated model proposed by Ratajczak. By integrating findings from matrix vesicles, plant-derived vesicles, and diverse tissue contexts, we frame EV release as an evolutionarily conserved process with profound implications for immunity, regeneration, oncology, and cardiovascular pathology. A second central aim of this review is practical and methodological. We map how the expansion of biological claims has driven urgent standardisation efforts, notably through the establishment of the International Society for Extracellular Vesicles (ISEV) and the successive MISEV guidelines (2014, 2018, 2023). These are complemented by community resources such as EV-TRACK, MIFlowCyt-EV, and the databases ExoCarta and Vesiclepedia. We summarise core experimental choices across isolation and characterisation techniques, including ultracentrifugation, size exclusion chromatography, density gradients, flow cytometry, nanoparticle tracking analysis, and electron microscopy, while outlining persistent bottlenecks in purity, standardised nomenclature, and experimental reproducibility. Finally, we provide concise biographical sketches of key contributors and an overview of major EV-focused journals and ISEV meetings that anchor consensus-building and the translation of fundamental knowledge into clinical and industrial applications. Full article

Extracellular vesicles (EVs) are membrane-bound particles secreted by most cell types that play a pivotal role in intercellular communication via transporting protein, nucleic acid, lipid, and metabolite cargos. Among EVs, exosomes are a well-characterized subtype, typically ranging from 10–150 nm in diameter and originating from the endosomal pathway via the formation of multivesicular bodies that fuse with the plasma membrane. EVs/exosomes can be isolated from various biological fluids and cultured cells, with production and yield influenced by the cell type and culture conditions. Isolation methods, including ultracentrifugation or density-based ultracentrifugation, tangential flow filtration, size-exclusion chromatography, immunoaffinity and membrane-affinity capture, and recently developed commercial equipment, offer distinct advantages and limitations in terms of purity, scalability, and exosome integrity. Characterization techniques, such as nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), cryogenic electron microscopy (cryo-EM), atomic force microscopy (AFM), Western blotting, flow cytometry, and dynamic light scattering (DLS), assess exosome size, morphology, and biomarker expression. Given their biocompatibility and inherent targeting capabilities across a diverse range of diseases, EVs/exosomes hold clinical promise as diagnostic biomarkers, cell-free therapeutics, drug delivery vehicles, immune modulators, and in regenerative medicine. However, these emerging fields in exosome medicine continue to face challenges in standardizing EV sourcing, production, purification, yield, bio-targeting, drug loading, and drug delivery. While EVs/exosomes represent a rapidly advancing frontier in biomedical science, robust protocols for standardization and scalable production will be essential for their successful translation into clinical applications. This article provides a comprehensive overview of EV/exosome origins, their biological functions, the approaches for their isolation and characterization, and their therapeutic potential. Full article

Exocytosis is a fundamental biological process in all eukaryotes involving the vesicular transport of cellular cargo to the plasma membrane or extracellular space. However, in walled organisms such as plants, fungi, and certain archaea, the rigid cell wall presents a unique barrier to vesicular secretion. The dense, structured matrix of the mature cell wall restricts the passage of macromolecules and vesicles, raising the fundamental question of how vesicle secretion operates in this constrained environment. In the present study, we integrate transmission electron microscopy (TEM), cryo-electron tomography (cryo-ET), and serial section electron tomography (SS-ET) to investigate the structural mechanisms underlying cell wall-related exocytosis. We demonstrate that secretory vesicles do not undergo fusion with the plasma membrane in cell wall-related vesicle secretion in Arabidopsis thaliana (A. thaliana) and Saccharomyces cerevisiae (S. cerevisiae). Furthermore, in the floral nectary of A. thaliana, we identify the details of vesicles inside the multivesicular body (MVB)-like structure in cell wall. Collectively, these results reveal distinct vesicle secretion pathways adapted to the presence of a cell wall, expanding our understanding of how secretory vesicles traverse and deliver cargo beyond the plasma membrane in walled eukaryotic cells. Full article

Cystinosis is a rare lysosomal storage disorder characterized by defective cystine transport and progressive multi-organ damage, with the kidney being the primary site of pathology. In addition to the traditional perspective on lysosomal dysfunction, recent studies have demonstrated that cystinosis exerts a substantial impact on cellular energy metabolism, with a particular emphasis on oxidative pathways. Mitochondria, the central hub of ATP production, exhibit structural abnormalities, impaired oxidative phosphorylation, and increased reactive oxygen species. These factors contribute to proximal tubular cell failure and systemic complications. This review highlights the critical role of energy metabolism in cystinosis and supports the emerging idea of organelle communication. A mounting body of evidence points to a robust functional and physical association between lysosomes and mitochondria, facilitated by membrane contact sites, vesicular trafficking, and signaling networks that modulate nutrient sensing, autophagy, and redox balance. Disruption of these interactions in cystinosis leads to defective mitophagy, accumulation of damaged mitochondria, and exacerbation of oxidative stress, creating a vicious cycle of energy failure and cellular injury. A comprehensive understanding of these mechanisms has the potential to reveal novel therapeutic avenues that extend beyond the scope of cysteamine, encompassing strategies that target mitochondrial health, enhance autophagy, and restore lysosome–mitochondria communication. Full article

Exosomes are nanoscale extracellular vesicles that mediate intercellular communication by transporting microRNAs, proteins, and lipids. Generated through Endosomal Sorting Complex Required for Transport (ESCRT)-dependent mechanisms or ESCRT-independent pathways, exosomes are released when multivesicular bodies fuse with the plasma membrane. The ESCRT-dependent pathway involves sequential protein complexes (ESCRT-0, I, II, III) that recognize and sort ubiquitinated cargo, induce membrane budding, and facilitate vesicle scission. In contrast, the ESCRT-independent pathway relies on membrane lipids such as ceramide and proteins like tetraspanins (CD9, CD63, CD81) to promote vesicle formation without ESCRT machinery. Furthermore, post-translational modifications, including ubiquitination, sumoylation, and phosphorylation, further serve as molecular switches, modulating the affinity of ESCRT complexes or cargo proteins for membrane domains and affecting ILV formation rates. In reproductive medicine, exosomes regulate oocyte maturation, embryo–endometrial crosstalk, placental development, and maternal–fetal communication. Altered exosomal signaling contributes to obstetric complications, including preeclampsia, gestational diabetes mellitus, and preterm birth, whereas distinct exosomal miRNA signatures serve as potential diagnostic biomarkers. In gynecology, dysregulated exosomes are implicated in endometriosis, polycystic ovary syndrome, premature ovarian insufficiency, and gynecological malignancies. In contrast, mesenchymal stem cell-derived exosomes show therapeutic promise in restoring ovarian function and enhancing fertility outcomes. The distinctive molecular profiles of circulating exosomes enable minimally invasive diagnosis, while their biocompatibility and ability to cross biological barriers position them as vehicles for targeted drug delivery. Characterization of accessible data provides non-invasive opportunities for disease monitoring. However, clinical translation faces challenges, including standardization of isolation protocols, establishment of reference ranges for biomarkers, and optimization of therapeutic dosing. This review summarizes exosome biogenesis, characterization methods, physiological functions, and clinical applications in obstetrics and gynecology, with an emphasis on their diagnostic and therapeutic potential. Future directions include large-scale biomarker validation studies, engineering approaches to enhance exosome targeting, and integration with precision medicine platforms to advance personalized reproductive healthcare. Full article

The short peptide AlaGluAspLeu (AEDL) stimulates shoot and root development in Nicotiana tabacum. Growing tobacco in the presence of AEDL was found to induce autophagy and programmed cell death, as demonstrated using immunodetection of the autophagy marker ATG8 and cytochrome c in the cytoplasm, as well as the detection of DNA breaks using the TUNEL assay. A detailed study of the ultrastructure of Nicotiana tabacum root cells grown in the presence of AEDL using transmission electron microscopy revealed fundamental structural differences from control cells. Control cells contained only lytic vacuoles, while in the presence of AEDL, tobacco root meristem cells contained predominantly protein-storing vacuoles and amyloplasts with numerous starch granules in the stroma. Characteristic types of phagophores were identified, forming numerous small autophagosomes with cytoplasmic regions, multivesicular bodies, or concentric membranes, possibly with cytoskeletal elements. Expression of autophagy protein genes revealed a decrease in TOR expression, which promoted autophagy activation and prevented ATG13 phosphorylation. ATG8 gene expression significantly increased in the presence of the AEDL peptide. Schematic diagrams of autophagy processes in root cells of control plants and those grown in the presence of AEDL are presented. Based on these data, it was concluded that stimulation of tobacco plant development in the presence of the AEDL peptide at a concentration of 10⁻⁷ M occurs due to the activation of metabolic processes and autophagy. Moreover, the synthesis of metabolites exceeds the required amount of nutrients, which accumulate in vacuoles and leucoplasts. Full article

Lindane, a persistent organochlorine pesticide, exerts toxic effects on the female reproductive system, compromising oocyte quality and maturation. However, the effects of this pesticide on mammalian oocyte morphology and ultrastructure remain unknown. This study investigated the effects of Lindane on mouse oocyte ultrastructure using an in vitro model with Transmission Electron Microscopy (TEM) at concentrations from 1 to 100 μM. The results revealed a progressive dose-related trend of alterations: at 1 μM, mild swelling of smooth endoplasmic reticulum (SER) vesicles; at 10 μM, increased SER dilation and cytoplasmic disorganization; and at 100 μM, pronounced vacuolization, mitochondrial swelling, dense lamellar bodies (dlbs), and multivesicular bodies (MVBs) indicative of autophagic activity. Mitochondrial alterations increased significantly with concentration: 3.2 ± 0.8 (control), 5.7 ± 1.0 (1 μM), 9.4 ± 1.5 (10 μM), and 16.8 ± 2.3 (100 μM) altered mitochondria per oocyte (p < 0.01). Vacuole frequency was notably elevated at 100 μM (4.3 ± 1.1 vs. 0.7 ± 0.5 in controls), and mislocalization of organelles within the ooplasm was observed. In conclusion, Lindane-induced oocyte ultrastructural alterations were observed at all tested concentrations but were more pronounced at 100 μM. These results highlight its impact on female fertility and may guide the search for protective agents, as well as efforts to reduce environmental exposure to endocrine disruptors. Full article

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are linked by shared genetic mutations and overlapping clinical features, forming a clinical spectrum. This systematic review and meta-analysis analysed 97 studies, including 3212 patients with key ALS/FTD gene mutations, to identify gene-specific behavioural profiles. Chromosome 9 open reading frame 72 (C9orf72) mutations were strongly associated with psychotic symptoms and aggression, while superoxide dismutase 1 (SOD1) mutations had minimal cognitive effects. Progranulin (PGRN) mutations correlated with apathy and hallucinations, microtubule-associated protein tau (MAPT) mutations with disinhibition, and charged multivesicular body protein 2B (CHMP2B) with social impairments. Fused in sarcoma (FUS) mutations caused early sleep disturbances, TANK-binding kinase 1 (TBK1) led to disinhibition, and presenilin 1 and 2 (PSEN1/2) was linked to severe aggression. Prodromal cognitive changes in PGRN, MAPT, and CHMP2B mutations suggested early disease onset. Despite overlapping symptoms and clinical heterogeneity, understanding gene-specific patterns could inform tailored care strategies to enhance the quality of life for ALS and FTD patients. This study calls for refined guidelines integrating genetic behavioural profiles to improve patient and family support. Full article

Endosomal dysfunction is one of the earliest cellular signs in Alzheimer’s disease. Tumor susceptibility gene 101 protein (TSG101) is a component of the endosomal sorting complex required for transport (ESCRT)-I, which plays a key role in sorting ubiquitinated cell surface proteins and lipids onto intraluminal vesicles of multivesicular bodies for trafficking to lysosomes or autophagosomes for degradation, or to the plasma membrane for exosomal secretion. TSG101-dependent trafficking has been implicated in the propagation and spread of misfolded proteins associated with neurodegenerative diseases. We used transgenesis mice to study the in vivo consequences of disrupting TSG101-dependent trafficking in adult neurons. Mice lacking Tsg101 in forebrain neurons (Tsg101^ck2-null) showed rapid loss of hippocampal neurons and progressive forebrain atrophy. Astrogliosis was apparent in the dentate gyrus within 1 week of deleting Tsg101, followed by apoptosis of hippocampal CA3 neurons and accumulation of the autophagy adapter P62/SQSTM1 and ubiquitinated proteins. Failure to detect lipidated LC3 indicated autophagy was impaired rather than upregulated. Endosomal markers (RAB5 and RAB7) and amyloid protein also accumulated in hippocampal neurons of Tsg101^ck2-null mice. Our data establish a critical role for TSG101 in neuronal survival and demonstrate the importance of the in vivo assessment of gene and protein functions. Full article

The endosomal sorting complexes required for transport (ESCRT) comprise a fundamental cellular machinery with remarkable versatility in membrane remodeling. It is multifunctional in the multivesicular body (MVB) biogenesis, exosome formation and secretion, virus budding, cytokinesis, plasma membrane repair, neuron pruning, and autophagy. ESCRT’s involvement in cellular mechanisms extends beyond basic membrane trafficking. By directly interacting with autophagy-related (ATG) proteins and facilitating autophagosome-lysosome fusion, ESCRT ensures cellular homeostasis. Dysregulation in ESCRT function has been implicated in cancer, neurodegenerative disorders, and infectious diseases, underscoring its critical role in numerous pathologies. Hepatitis B virus (HBV) is an enveloped virus that exploits ESCRT and autophagy pathways for viral replication, assembly, and secretion. This review synthesizes recent mechanistic insights into ESCRT’s multifaceted roles, particularly focusing on its interactions with autophagy formation and the HBV lifecycle. Full article

Cancer is a significant global health challenge, where early diagnosis is crucial for enhancing patient survival and mitigating the treatment burden on patients. Exosomes are extracellular vesicles released through the fusion of multivesicular bodies with cell membranes, carrying disease-associated information from donor cells. This makes exosomes a key biomarker in liquid biopsy analysis, particularly for early cancer detection. Developing cost-effective, straightforward, and sensitive exosome biosensing technologies is of significant practical importance. To date, a large number of fluorescence-based exosome biosensors have relied on the Fluorescence Resonance Energy Transfer (FRET) principle. This review introduces the basic background of the field and the principle of FRET-based exosome sensors, followed by a systematic summary of their progress categorized by different transduction elements or mechanisms. Finally, this work discusses the current challenges in the field and proposes potential solutions and future prospects, aiming to encourage and inspire the development of new approaches for advanced FRET exosome biosensors. Full article

Background/Objectives: Glioblastomas are the most common brain malignancies. Despite the implementation of multimodal therapy, patient life expectancy after diagnosis is barely 12 to 18 months. Glioblastomas are highly heterogeneous at the genetic and epigenetic level and comprise multiple different cell subpopulations. Therefore, small molecules such as nanobodies, able to target membrane proteins specific to glioblastoma cells or specific cell types within the tumor are being investigated as novel tools to treat glioblastomas. Methods: Here, we describe the identification of such a nanobody and its in silico and in vitro validation. NB3F18, as we named it, is directed against the membrane-associated protein FREM2, overexpressed in glioblastoma stem cells. Results: Three dimensional in silico modeling indicated that NB3F18 and FREM2 form a stable complex. Surface plasmon resonance confirmed their interaction with moderate affinity. As we demonstrated by flow cytometry, NB3F18 binds to glioblastoma stem cells to a greater extent than to differentiated glioblastoma cells and astrocytes. Immunocytochemistry revealed surface localization of NB3F18 on glioblastoma stem cells, whereas cytoplasmic localization of NB3F18 was observed in other cell lines. NB3F18 was detected by transmission electron microscopy on the plasma membrane and in various compartments of the endocytic pathway, from endocytic vesicles to multivesicular bodies (endosomes) and lysosomes. Interestingly, NB3F18 was cytotoxic to glioblastoma stem cells. Conclusions: Collectively, NB3F18 has been qualified as an interesting tool to target glioblastoma cells and as a potential vehicle to deliver biological or pharmaceutical agents to these cells. Full article