The case for treating large extracellular vesicles as their own category rests on a fundamental difference in origin. Small extracellular vesicles arise from two well-characterised sources: the endosomal system, which produces exosomes when multivesicular bodies fuse with the plasma membrane, and the plasma membrane itself, which buds off small ectosomes. Most large extracellular vesicles, by contrast, stem directly from the plasma membrane, although the review emphasises that the various subtypes follow strikingly different biogenesis routes. This distinction matters because it shapes what the vesicles carry, how they are released, and what they do once they arrive at a recipient cell. A vesicle born from a dying cell’s collapsing membrane carries a very different cargo than one pinched off from the rear of a migrating cell or extruded from a neuron under proteotoxic stress.

The classical cast of large vesicles includes apoptotic bodies, microvesicles and large oncosomes, each recognised for years and each associated with distinct biology. Apoptotic bodies form as dying cells disassemble themselves, a process driven by caspase-mediated activation of ROCK1, which triggers the actomyosin contraction underlying membrane blebbing. These fragments are far more than debris: they broadcast find-me and eat-me signals that orchestrate the orderly clearance of dead cells by phagocytes, and recent work shows they can stimulate stem cell proliferation during tissue maintenance and couple bone resorption to bone formation. Microvesicles, shed directly from the plasma membrane of viable cells, depend on the ARF6–myosin light chain–actomyosin axis for their scission, and tumour cells exploit this pathway to spread oncogenic receptors such as EGFRvIII and drug-resistance proteins like P-glycoprotein to neighbouring cells. Large oncosomes, the giant vesicles shed by cancer cells, have been linked to loss of the formin DIAPH3 and to the reprogramming of fibroblasts in the tumour microenvironment through MYC-dependent mechanisms.

The most exciting chapters of the review concern the newer subtypes, several of which were unknown when the extracellular vesicle field consolidated its nomenclature under the MISEV guidelines. Migrasomes, discovered in 2015 by Li Yu’s group, form on retraction fibres left behind by migrating cells and serve as organelles for controlled release of cytoplasmic contents during cell migration. Their formation depends on the assembly of micron-scale tetraspanin-enriched macrodomains, driven by sphingomyelin synthase 2, phosphatidylinositol 4,5-bisphosphate signalling through Rab35, and palmitoylation of the tetraspanin Tspan4. Migrasomes have since been implicated in zebrafish organ morphogenesis, embryonic angiogenesis, mitochondrial quality control through a process termed mitocytosis, and even coagulation, with neutrophil-derived migrasomes identified as essential components of the clotting system.

Equally remarkable are the vesicles that cells use to jettison damaged components. Exophers, first described in Caenorhabditis elegans neurons in 2017, are enormous vesicles through which stressed neurons extrude toxic protein aggregates and dysfunctional mitochondria, providing a proteostasis escape route with obvious implications for neurodegenerative disease. Mitophers, reported in 2023, represent a form of mitochondria-specific ectocytosis through which sperm cells regulate their mitochondrial complement and, consequently, their fertility, establishing a paradigm for cargo-selective packaging of entire organelles into large vesicles. Blebbisomes, characterised in 2025, are large, organelle-rich vesicles with startling cell-like properties, carrying broad organellar cargo and expanding the functional repertoire attributed to vesicle-mediated communication. Large ageing neutrophil-derived vesicles, or LAND-Vs, add an anti-inflammatory dimension: they control complement activation and facilitate the resolution of inflammation, revealing that large vesicles can dampen immune responses as well as provoke them.

Beneath this diversity lies a set of shared physical and biochemical principles that the review dissects with technical precision. Membrane budding and scission require the coordination of actomyosin contractility, hydrostatic pressure and lipid remodelling. The transbilayer distribution of phospholipids emerges as a recurring regulatory node: flippases maintain lipid asymmetry, while scramblases such as TMEM16F collapse it in a calcium-dependent manner, exposing phosphatidylserine on the outer leaflet and promoting both vesicle release and the engulfment signals that mark apoptotic material for clearance. Disruption of flippase localisation in C. elegans increases extracellular vesicle budding, demonstrating that lipid asymmetry actively suppresses vesiculation in healthy membranes. Protein crowding at the membrane, tetraspanin microdomains, lipid rafts and caveolin-dependent dynamics each contribute to curvature generation at specific sites, while the ESCRT machinery contributes its membrane-scission capabilities to several of these pathways.

Cargo sorting into large vesicles follows equally mechanistic rules. The ARF6–Exportin-5 axis delivers pre-microRNA cargo into tumour microvesicles, Cdc42 acts as a regulatory node for microvesicle biogenesis, and RNA-binding proteins govern which transcripts are packaged. Zipcode-like sequence elements enrich specific mRNAs in microvesicles, and integrin pairing with extracellular matrix proteins determines where migrasomes form on retraction fibres. Delivery to recipient cells proceeds through clathrin-independent endocytosis and macropinocytosis, although the review is careful to note that the field still lacks definitive experimental support for functional cargo transfer in many contexts, a caution that reflects growing scrutiny of the extracellular vesicle cargo-transfer hypothesis.

The pathological implications are broad and, in several cases, already translating toward clinical applications. In cancer, large vesicles transfer oncogenic receptors, promote angiogenesis through CD147 and VEGF signalling, carry retrotransposon elements and amplified oncogene sequences, and mediate immune evasion through vesicle-associated PD-L1, which Epstein–Barr virus LMP1 enhances. In neurodegeneration, microglia convert aggregated amyloid-beta into neurotoxic forms through microvesicle shedding, while macrophage-derived migrasomes activate complement-dependent blood–brain barrier damage in cerebral amyloid angiopathy and promote paracrine senescence in ageing brain. Inflammation, thrombosis and kidney injury each feature large-vesicle mechanisms, with urinary podocyte-derived migrasomes emerging as early indicators of glomerular damage and plasma apoptotic bodies serving as non-invasive biomarkers of apoptosis in ischemic stroke.

Methodological rigour occupies a central place in the review’s argument. The authors catalogue the technologies now enabling multidimensional characterisation, from cryo-electron microscopy and super-resolution structured illumination microscopy to nanoparticle tracking analysis, tunable resistive pulse sensing, asymmetric flow field-flow fractionation and microfluidic affinity capture. Deep-learning platforms for automated detection of vesicle exocytosis and self-supervised image enhancement for long-term subcellular recording are extending what live imaging can reveal. Yet the review is equally candid about pitfalls: fluorescent lipophilic dyes can confound uptake studies, isolation methods such as ultracentrifugation and tangential flow filtration yield different preparations, and loss-of-function studies and mechanistic analyses must be appropriately integrated to ensure rigour and reproducibility. Engineered migrasomes that serve as thermally stable vaccination platforms hint at the therapeutic horizon, but the authors stress that biodistribution depends on cell source, administration route and targeting ligands, and that the field’s progress will depend on pairing new tools with the disciplined standards set out in the MISEV2023 framework. What emerges is a portrait of a maturing discipline: one in which the largest and most structurally complex members of the extracellular vesicle family are finally being studied with the systematic attention their biology demands.

Subject of Research: Subtypes, biogenesis and functions of large extracellular vesicles

Article Title: Towards a systematic understanding of the diverse subtypes, biogenesis and functions of large extracellular vesicles

Article References: Huang, Y., Xie, R., Ma, J., & Yu, L. (2026). Towards a systematic understanding of the diverse subtypes, biogenesis and functions of large extracellular vesicles. Nature Reviews Molecular Cell Biology. https://doi.org/10.1038/s41580-026-01021-8

Image Credits: AI Generated

DOI: 10.1038/s41580-026-01021-8

Keywords: large extracellular vesicles, migrasomes, apoptotic bodies, microvesicles, large oncosomes, exophers, blebbisomes, mitophers, plasma membrane budding, tetraspanins, extracellular vesicle biogenesis, cell-cell communication

At the heart of this discovery is the insight that adhesion GPCRs, a unique subset of the diverse GPCR family characterized by extensive extracellular adhesion-like domains, are capable of orchestrating the biogenesis of migrasomes and retractosomes. These specialized EVs serve as cellular parcels, encapsulating activated GPCRs and ferrying them to recipient cells. Through this process, aGPCRs not only mediate adhesion and mechanical sensing but also transmit bioactive signals in a form previously unappreciated, effectively extending their signaling reach beyond the confines of the originating cell membrane.

Migrasomes, intriguing organelles recently characterized for their role in cellular waste disposal and intercellular communication, emerge from cellular retraction fibers during cell migration. Retractosomes are a related but distinct EV subtype involved in similar yet mechanistically discrete signaling activities. The study reveals that the activation of aGPCRs triggers these vesicles’ formation primarily via their extracellular adhesion-like domains coupled with intracellular G-protein signaling, particularly through the G_12/13 subfamily. This bifurcated mechanism underscores a sophisticated coupling of extracellular interactions and intracellular pathways that culminate in the excision and release of receptor-laden EVs.

A pivotal aspect of this mechanism involves ectocytosis—an active cellular process whereby portions of the plasma membrane bud off to form extracellular vesicles carrying specific cargo. Here, activated aGPCRs undergo ectocytosis, effectively packaging themselves into migrasomes and retractosomes. These vesicles, once released, carry functional GPCR complexes capable of engaging with recipient cells. This process is not passive; the receptors housed within the EV membrane remain competent to activate downstream signaling cascades upon internalization by target cells, thereby replicating GPCR-mediated signal transduction in new cellular contexts.

The implications of this mechanism are profound, particularly in the context of tumor biology. The researchers provide compelling evidence that cancer-cell-derived migrasomes serve as vehicles for the intercellular transfer of aGPCRs such as GPR56. By transferring these active receptors to endothelial cells in the tumor microenvironment, migrasomes potentiate angiogenesis, a critical process in tumor growth and metastasis. This finding suggests that migrasome-mediated GPCR signaling could be a hitherto unrecognized driver of angiogenic remodeling, possibly furnishing new therapeutic targets for vascular intervention in solid tumors.

Delving deeper into the molecular underpinnings, the study elucidates that the G_12/13-protein signaling axis exerts a central role in the formation of migrasomes and retractosomes. These heterotrimeric G-proteins, upon activation by aGPCRs, initiate downstream signaling cascades involving Rho family GTPases, which regulate cytoskeletal dynamics and membrane remodeling. This precise orchestration enables the generation of membrane blebs and cellular protrusions necessary for migrasome biogenesis. The coupling of extracellular adhesion events with G_12/13 signaling thus bridges environmental sensing with vesicle formation, ensuring spatial and temporal control over EV release.

Interestingly, the extracellular adhesion-like domains of aGPCRs themselves appear indispensable for migrasome formation. These domains enable the receptors to engage with the extracellular matrix or other cell surfaces, transmitting mechanical or biochemical cues that prime cellular machinery for vesicle biogenesis. This finding aligns with the recognized roles of aGPCRs in cell adhesion and migration but now extends their functional repertoire to include direct involvement in EV-mediated signaling—a conceptual leap in understanding GPCR functional diversity.

The fate of migrated GPCRs within recipient cells reveals yet another layer of complexity. Once internalized through endocytosis of migrasomes or retractosomes, these receptors maintain their signaling capacity, capable of activating G-protein signaling de novo in the recipient cytoplasm. This phenomenon of signal transduction propagation via EV-mediated receptor transfer challenges classical paradigms of membrane receptor localization and function, underscoring a dynamic mode of receptor redistribution and signal initiation in multicellular contexts.

Given the extensive involvement of GPCRs across physiological and pathological processes, the discovery that aGPCRs exploit EV-mediated ectocytosis for intercellular communication broadens the conceptual framework for understanding signal integration across tissues. It also offers new avenues for therapeutic intervention, particularly in diseases where aberrant GPCR signaling contributes to pathology, such as cancer, neurodegeneration, and immune disorders. Targeting the migrasome formation or receptor packaging mechanisms may yield novel strategies to interrupt maladaptive signal propagation.

Moreover, this study raises intriguing questions about the potential diversity of cargoes within migrasomes. While the focus here is on aGPCRs, migrasomes could carry diverse bioactive molecules, including other membrane proteins, nucleic acids, or metabolites, shaping recipient cell behavior in multifaceted ways. Future research promises to unravel this cargo complexity and its physiological significance, potentially revealing migrasomes as central hubs of intercellular communication beyond classical ligand-receptor paradigms.

The robust experimental approach combining in vitro cellular models and in vivo animal studies strengthens the validity of these findings. Notably, the observation of cancer-cell-derived migrasomes transferring GPR56 in vivo highlights the physiological relevance of this mechanism, affirming that migrasome-mediated receptor transfer is not an artifact of cell culture but a bona fide biological phenomenon with implications for tissue remodeling and disease progression.

In addition to tumor angiogenesis, the capacity of migrasomes to propagate GPCR signals suggests roles in developmental biology, immune responses, and tissue homeostasis. Given that GPCR activity is intricately involved in diverse signaling networks, their expanded reach via migrasome-mediated transfer could coordinate complex cellular behaviors across developmental stages and environmental challenges. Whether similar mechanisms operate across different cell types and physiological conditions remains a fertile ground for exploration.

From a biophysical standpoint, the process of ectocytosis and migrasome formation mediated by aGPCRs reflects a finely balanced interplay between membrane tension, cytoskeletal dynamics, and receptor-ligand interactions. The study invites further scrutiny into the molecular machinery and lipid microdomains involved, which may reveal novel targets for modulating EV biogenesis and release. Understanding these parameters at high resolution could accelerate the design of artificial vesicles for therapeutic delivery or biosensing applications.

In summary, this seminal work illuminates the multifaceted roles of adhesion GPCRs in orchestrating a novel vesicle-mediated signaling axis. By inducing the formation of migrasomes and retractosomes and mediating the intercellular transfer of active GPCRs, aGPCRs establish a new paradigm of cell-to-cell communication that transcends traditional mechanisms. These findings not only advance our mechanistic understanding of GPCR biology but also unveil new therapeutic targets and biomarkers with broad clinical relevance.

The discovery of aGPCR-induced ectocytosis as a driver of intercellular GPCR signal propagation thus represents a significant leap forward in the field, offering a transformative lens through which to view cellular communication, signal transduction, and disease biology. The potential to exploit this mechanism to modulate pathological signaling or enhance regenerative processes heralds an exciting frontier in molecular and cellular medicine.

Subject of Research: Mechanisms of adhesion G-protein-coupled receptor (aGPCR)-mediated extracellular vesicle formation and intercellular signal propagation.

Article Title: Adhesion GPCR-induced ectocytosis mediates intercellular GPCR signal propagation.

Article References:
Huang, G., Li, N., Chen, Y. et al. Adhesion GPCR-induced ectocytosis mediates intercellular GPCR signal propagation. Nat Chem Biol (2026). https://doi.org/10.1038/s41589-026-02148-7

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41589-026-02148-7