Migrasome as a novel organelle: Biogenesis, physiological functions, and therapeutic potential

Nucleation

Enrichment analysis of genes that specifically affect migrasome formation without altering retraction fiber structure indicates that ceramide catabolism is the most prominently enriched biological process in migrasomes.^[27] As a major lipid component of the cell membrane, sphingomyelin (SM) is synthesized through the conversion of ceramide, a reaction catalyzed by sphingomyelin synthase (SMS).^[28] Among SMS enzymes, the SMS2 isozyme is a key regulator localized to the plasma membrane, where it efficiently converts ceramide present at the plasma membrane into SM.^[29] Migrasomes are rich in SMS2, which actively participates in migrasome formation (Figure 1a).^[27,30] SMS2 specifically aggregates into SMS2 foci on the basement membrane at the leading edge of migrating cells and forms stable attachments to the matrix via its extracellular domain. As cells migrate forward, these anchored SMS2 foci are “left behind” at the cell rear due to their immobility relative to the cell body. Eventually, they localize to retraction fibers, becoming initiation sites for migrasome biogenesis.^[27] Functional experiments further confirmed that inhibition of SMS2 almost completely blocks migrasome formation, while exogenous SM supplementation effectively restores this process. These findings directly confirm that SM synthesis catalyzed by SMS2 is the core biochemical reaction for migrasome nucleation.^[27] Ceramide synthases (CerS), as rate-limiting enzymes in ceramide synthesis, include several family members.^[31,32] Knockdown experiments targeting CerS5 showed significant inhibition of migrasome formation, indicating that CerS5-mediated ceramide synthesis is a crucial source of substrates for SMS2.^[22,27] Notably, SM generated by SMS2 not only provides structural lipid components for migrasomes but also contributes to migrasome biogenesis by promoting the assembly of tetraspanin-enriched macrodomains (TEMAs).^[27]

Maturation

The conversion of ceramide to SM at nucleation sites establishes the basis for subsequent migrasome formation steps.^[27] Simultaneously, signaling cascades occur at these sites, transforming them into MFSs during maturation.^[21] Phosphatidylinositol 4, 5-bisphosphate (PI [4, 5] P₂), a key phosphoinositide predominantly localized on the inner leaflet of the plasma membrane, plays an essential regulatory role in migrasome maturation.^[33,34] PI (4, 5) P₂ is primarily synthesized by phosphatidylinositol 4-monophosphate 5-kinases (PIP5Ks).^[35] Prior to migrasome formation, phosphatidylinositol 4-monophosphate 5-kinase 1A (PIP5K1A) localizes to MFSs ahead of time and catalyzes the production of PI (4, 5) P₂ at these sites.^[36] Subsequently, PI (4, 5) P₂ recruits the small guanosine triphosphatase (GTPase) Rab35 to MFSs. Rab35 specifically enriches integrin α5 at MFSs by binding to the glycine-phenylalanine-phenylalanine-lysine-arginine (GFFKR) motif of integrin α5 (Figure 1b).^[36] In zebrafish embryos, using PIP5K1A inhibitors or peptides that disrupt Rab35-integrin α5 interactions effectively inhibits migrasome formation.^[23] Similarly, knocking down integrin α5 in normal rat kidney (NRK) cells suppresses migrasome generation.^[21] Therefore, initial PI (4, 5) P₂ synthesis followed by the recruitment of Rab35-integrin α5 constitutes a critical maturation step during migrasome biogenesis, facilitating the transition into the expansion stage.

Expansion

Following maturation, migrasomes expand along retraction fibers. Migrasome anchoring points preferentially stabilize at sites of strong adhesion to the ECM.^[21] The PI (4, 5) P₂-Rab35-integrin signaling axis promotes the formation and stabilization of junctions by enhancing adhesion at MFSs, thus creating favorable conditions for initial expansion driven by membrane tension fluctuations.^[23,35,36] The expansion process depends on the recruitment and stabilization of tetraspanins (TSPANs). The mammalian Tetraspanin (TSPAN) family comprises 33 members,^[37] among which tetraspanin 4 (TSPAN4) is highly enriched in migrasomes, serves as a signature biomarker for migrasome identification, and plays a key role in migrasome biogenesis.^[1] Knocking down TSPAN 4 significantly reduces migrasome formation, whereas overexpressing TSPAN4 or other TSPAN family members promotes migrasome generation.^[24] During cell migration, TSPAN4 is recruited from retraction fibers onto the surface of developing migrasomes, forming dynamic puncta whose signal intensity gradually strengthens and stabilizes as migrasomes expand. Once incorporated into migrasomes, TSPAN4 does not return to retraction fibers, indicating its essential structural role in migrasome assembly.^[38] Migrasome membranes are rich in cholesterol and other TSPAN members, including TSPAN7 and TSPAN9.^[39] These proteins interact with cholesterol, membrane receptors, and adhesion molecules, forming TSPAN-enriched microdomains (TEMs). These microdomains further cluster into larger macrodomains, enhancing membrane rigidity.^[24,40] As retraction fibers continuously stretch, these domains expand, gradually developing into mature migrasomes (Figure 1c).^[41] In addition, Synaptotagmin-1 (Syt1) primes migrasome formation sites for TSPAN4-mediated stabilization by initiating their expansion.^[42]

Cell Migration patterns

Cell migration patterns influence migrasome formation by modulating retraction fiber dynamics. These patterns refer to the movement trajectories of cells responding to internal and external environmental signals. They directly regulate migrasome production by affecting the length, stability, and formation efficiency of retraction fibers. For example, cells migrating rapidly and linearly tend to form longer retraction fibers, thereby generating more migrasomes. In contrast, cells frequently changing direction produce narrower tails, resulting in fewer retraction fibers and thus fewer migrasomes.^[26] Cell migration speed influences migrasome formation by modulating the length of retraction fibers. This regulatory process likely involves molecular mechanisms such as the RhoA/ROCK signaling pathway. As the core signaling axis responsible for dynamically regulating the cytoskeleton, this pathway controls actin-myosin contractility, coordinating the severing and stabilization of retraction fibers, and consequently determining the efficiency of migrasome release. Additionally, vimentin plays a critical role in regulating cell migration behavior.^[43] It influences cell migration by controlling the formation of actin stress fibers or regulating lamellipodia generation.^[44,45] The absence of vimentin leads to reduced directional persistence and migration speed, subsequently diminishing retraction fiber formation and migrasome production. This finding underscores the decisive influence of cell migration mode on migrasome formation. Future studies should further investigate the negative regulatory mechanisms of migrasome biogenesis and provide in-depth analyses of molecular details governing active release, thereby refining the molecular regulatory network linking cell migration patterns to migrasome formation.^[26]

Maintaining mitochondrial homeostasis

Mitochondria are involved in cellular aerobic respiration, and the maintenance of normal mitochondrial function is essential for cellular homeostasis. During cellular metabolism, mitochondria may experience various forms of damage, such as DNA mutations, membrane potential decline, and increased production of reactive oxygen species (ROS).^[46] Impaired mitochondrial function can result in metabolic disorders, cardiovascular diseases, neurological conditions, and aging.^[47] To maintain mitochondrial and cellular homeostasis and prevent damaged mitochondria from harming cells, defective mitochondria are specifically encapsulated in autophagosomes, which then fuse with lysosomes for degradation, a process known as mitophagy.^[48] Mitophagy selectively recognizes and removes damaged mitochondria to prevent further cellular harm. Jiao et al. demonstrated that after mild mitochondrial stress, damaged mitochondria are transported into migrasomes and subsequently exported from the cell, achieving mitochondrial quality control and maintaining cellular homeostasis. This alternative process is termed mitocytosis.^[6] Notably, mitocytosis occurs only under mild mitochondrial stress; severe mitochondrial stress is primarily managed through mitophagy.^[49] During mitocytosis, mild mitochondrial stress reduces mitochondrial binding to inward-transporting dynamin, while increasing affinity to the outward-transporting kinesin family member 5B (KIF5B). Damaged mitochondria are thus preferentially transported toward the cell periphery by KIF5B. Subsequently, these mitochondria associate with cortical actin at the plasma membrane via myosin 19 (Myo19), ultimately being incorporated into migrasomes through dynamin-related protein 1 (Drp1)-mediated fission (Figure 2a).^[6] Mitocytosis plays a crucial role in maintaining mitochondrial homeostasis, protecting cells from mitochondrial stress by discarding damaged mitochondria and thereby preserving mitochondrial membrane potential (MMP) and respiration levels. Mitocytosis thus provides the first direct link between mitochondrial health and cell migration.^[6]

Figure 2

Physiological functions of migrasomes. (a) Migrasomes play a key role in sustaining mitochondrial homeostasis. Under mild mitochondrial stress, the binding affinity of KIF5B increases, promoting the transport of impaired mitochondria to the plasma membrane. Subsequently, with the involvement of Myo19, these mitochondria associate with actin at the membrane and are incorporated into migrasomes through Drp1-mediated fission prior to extracellular release. This mechanism supports mitochondrial quality control and contributes to the maintenance of cellular homeostasis. (b) Migrasomes facilitate intercellular communication through lateral material transfer. They enable the horizontal delivery of functional proteins and translationally active mRNA to recipient cells, thereby restoring the expression of specific proteins. (c) Migrasomes play a critical role in promoting embryonic development. Migrasomes derived from zebrafish blastulae contain chemokines such as CXCL12, which are essential for the proper development of zebrafish embryonic organs. (d) Migrasomes play a significant role in promoting angiogenesis. In the chorioallantoic membrane of chicken embryos, monocytes release migrasomes that are enriched with chemokines (such as CXCL12) and angiogenic factors (including VEGF). These migrasomes enhance tube formation by vascular endothelial cells and facilitate further monocyte recruitment, collectively contributing to enhanced angiogenesis. (e) Neutrophil-derived migrasomes specifically adsorb coagulation factors and accumulate at the injury site, where they activate platelets and promote the formation of hemostatic plugs through migrasome-platelet binding. This mechanism enables rapid vascular repair and effective bleeding control while preserving blood fluidity. KIF5B: kinesin family member 5B; Myo19: Myosin 19; Drp1: dynamin-related protein 1; CXCL12: C-X-C motif chemokine ligand 12; VEGF: vascular endothelial growth factor.

In an in vivo neutrophil model, neutrophils produced abundant migrasomes containing damaged mitochondria. ^[6] TSPAN9-knockout mice displayed reduced migrasome formation and significantly decreased MMP in neutrophils. Critically, TSPAN9 deficiency severely impaired neutrophil viability, demonstrating the necessity of mitocytosis for neutrophil survival.

Material transfer

Following cell migration, migrasomes persist at the original location until maturation, subsequently undergoing leakage or rupture to release their vesicular contents and bioactive molecules, or becoming engulfed by neighboring cells. This indicates that migrasomal cargo can be directly transferred to recipient cells through these mechanisms, potentially constituting a novel mode of intercellular communication. ^[2] Migrasomes are known to contain bioactive substances, including proteins and mRNA.^[5] Functional proteins and translationally active mRNA molecules can be laterally transferred by migrasomes to recipient cells, restoring the expression of relevant proteins. Upon migrasome rupture and the subsequent release of various signaling molecules, they effectively mediate the biological functions of recipient cells (Figure 2b).^[5] However, this phenomenon has primarily been documented in vitro, with in vivo studies investigating the functional consequences of migrasome-mediated material transfer on recipient cells notably lacking. Further research is required to elucidate the physiological relevance and mechanistic details of this process in living organisms.

Embryonic development

Migrasomes contain diverse signaling molecules, including cytokines, angiogenic factors, and chemokines.^[50] The regulated release of these molecules critically influences embryonic development.^[3,4] Researchers engineered zebrafish embryos to express migrasome markers and observed abundant migrasomes and retraction fibers via live-cell imaging. In TSPAN4a- and TSPAN7-knockout zebrafish, migrasome formation was reduced, resulting in developmental defects characterized by disrupted left-right asymmetry. Supplementation with exogenous migrasomes restored proper organ development, demonstrating that these developmental abnormalities directly result from migrasome deficiency rather than loss of TSPAN4a/TSPAN7 functions (Figure 2c).^[3] This study reveals a novel mechanism: migrasomes form membranous compartments that encapsulate signaling molecules for targeted release, thus providing precise spatiotemporal regulation of zebrafish embryonic development.^[3]

Angiogenesis

Vascular endothelial growth factor (VEGF), a key regulator of angiogenesis, is primarily synthesized and secreted by perivascular cells adjacent to nascent blood vessels.^[51,52] Secreted VEGF specifically binds to receptors on the surface of endothelial cells, triggering intracellular signaling cascades that promote neovascularization.^[53] Zhang et al. demonstrated that monocytes in the chick chorioallantoic membrane (CAM) generate migrasomes enriched with chemokines (e.g., CXCL12), VEGF, and transforming growth factor β-3 (TGF-β3).^[4] VEGF delivery via migrasomes establishes a pro-angiogenic niche at capillary formation sites, while migrasome-mediated CXCL12 transport recruits monocytes, creating a positive feedback loop that promotes CAM angiogenesis (Figure 2d). Monocyte depletion (via pharmacological or antibody approaches) or suppression of migrasome biogenesis (through TSPAN4 knockdown) severely impairs capillary neogenesis. Exogenous migrasome supplementation rescues defective capillary formation.^[4] These findings establish migrasomes as spatiotemporal signaling hubs: Their membrane-bound compartments package molecules for targeted release, coordinating physiological functions during angiogenesis.

Participate in blood coagulation

Neutrophil-derived migrasomes in circulation are critical components of the hemostatic system.^[7] Blood from both humans and mice contains abundant neutrophil-derived migrasomes that rapidly adsorb coagulation factors and accumulate at injury sites, triggering platelet activation through exposure of surface phosphatidylserine, thus amplifying thrombin generation.^[7,54] Activated platelets bind migrasomes and assemble porous hemostatic plugs, maintaining blood flow while sealing damaged vessels to prevent hemorrhage. To clarify the direct role of migrasomes in hemostasis, researchers used neutrophil-depleted mice in tail-tip bleeding assays. Neutrophil depletion prolonged bleeding time, an effect reversed by exogenous neutrophil-derived migrasomes (Figure 2e).^[7] This study establishes migrasomes as essential hemostatic regulators, revealing a novel mechanism for coagulation control and wound healing.

Urology

Podocyte injury is the central mechanism underlying the pathogenesis of kidney diseases.^[59] Podocyte injury reduces the glomerular filtration rate and leads to proteinuria.^[60,61] Podocytes are terminally differentiated cells unable to proliferate or regenerate. Compared with other kidney cells, damaged podocytes display greater migratory activity under disease conditions.^[62] Podocyte-derived migrasomes have been detected in the urine of mice with kidney injury, appearing prior to elevated urinary microalbumin. Thus, urinary migrasomes could serve as a non-invasive diagnostic indicator for podocyte damage.^[10] Clinical studies have also confirmed that migrasomes derived from podocytes in the urine of patients with kidney disease are associated with kidney injury,^[10,11] highlighting their potential use in nephropathy diagnosis and treatment. Although these studies directly link migrasomes and podocyte injury, the causal relationship between migrasome formation and disease progression has yet to be fully established.

Rac1, a member of the Rho family of small GTPases, regulates cellular signaling, migration, and inflammatory responses. Podocyte injury is characterized by aberrant activation of the Rac1 signaling pathway. Inhibition of Rac1 preserves podocyte structural and functional integrity.^[63] Liu et al. demonstrated a significant negative correlation between Rac1 inhibitor dosage and urinary migrasome quantity in injured podocyte models. This finding suggests that the protective effects of Rac1 inhibition on podocytes may be mediated through regulating migrasome release.^[10] These findings indicate a potential causal relationship between migrasomes and renal injury, yet the possibility that increased migrasome release is merely an accompanying phenomenon of cellular damage cannot be excluded. Current evidence primarily stems from observational studies utilizing mouse disease models and patient urine samples. There remains a lack of in vivo causal validation experiments, where migrasome biogenesis is specifically modulated to directly observe subsequent renal outcomes. Moreover, the sensitivity, specificity, and predictive value of urinary migrasomes as biomarkers, compared to established clinical gold standards such as eGFR and UACR, have not been validated in large-scale prospective cohort studies. Furthermore, the isolation and quantification of urinary migrasomes lack standardized methodologies, and challenges concerning their stability and assay reproducibility pose major technical barriers to clinical translation. Given the correlation between migrasome release and the extent of podocyte injury, targeted interventions against migrasome formation may represent a novel therapeutic strategy for kidney diseases.

Tumor

Migrasomes are widely present in highly migratory tumor cells and play a significant role in tumor metastasis. Wang et al. found abundant programmed death-ligand 1 (PD-L1) at the trailing edges of migrating tumor cells. After internalization by tumor cells, PD-L1-rich migrasomes can upregulate PD-L1 expression. Meanwhile, they promote tumor migration by secreting chemokines, becoming a key component of tumor metastasis mechanisms.^[9] Premetastatic niches (PMNs) are essential for tumor metastasis and are characterized by immune suppression, inflammatory responses, and angiogenesis.^[64,65] In bone metastasis, osteoclasts play a central role in forming PMNs.^[66] Studies have shown that tumor cells can deliver mRNA to osteoclast precursors via migrasomes, inducing their abnormal differentiation into osteoclasts and promoting pre-metastatic niche (PMN) formation.^[8] This suggests that inhibiting migrasome formation could provide a new strategy for the early prevention of tumor bone metastasis. However, this discovery is based on in vitro co-culture and animal models, and it is still necessary to prove whether blocking this pathway under in vivo conditions can completely inhibit the formation of metastatic foci. Nevertheless, further investigation is required to fully clarify the mechanistic roles of migrasomes.

The expression of cluster of differentiation 151 (CD151) in cancer cells is essential for migrasome biogenesis and may be utilized as a biomarker. Elevated CD151 expression facilitates migrasome formation, enhancing the invasiveness and angiogenic capacity of hepatocellular carcinoma (HCC) cells, thus promoting primary HCC progression.^[56] Further studies revealed that integrin alpha-5 (ITGA5) is upregulated in HCC tissues and correlates with poor clinical prognosis. Knockdown of ITGA5 significantly suppresses the proliferation, migration, and invasion of HCC cells, whereas its overexpression worsens malignant phenotypes.^[57]

As a biomarker and critical mediator of migrasome formation, TSPAN4 is frequently dysregulated across multiple tumor types.^[67] Previous studies showed that TSPAN4 promotes glioblastoma (GBM) progression through interaction with epidermal growth factor receptor (EGFR)^[58] and modulates immune cell infiltration within the tumor microenvironment.^[67] Migrasomes facilitate immune evasion, thereby supporting tumor invasion and metastatic dissemination. Consequently, targeting migrasome biogenesis represents a promising therapeutic strategy for tumor suppression. However, given its potential interference with physiological functions in normal cells, future research should prioritize developing targeted approaches to selectively inhibit migrasome production in tumor cells.

Neurology

Cerebral amyloid angiopathy (CAA) is a common neurodegenerative disorder characterized by β-amyloid (Aβ) deposition in small intracranial vessels.^[68] Predominantly affecting the elderly, CAA is an important cause of cognitive decline and intracerebral hemorrhage in this population.^[69] Hu et al. were the first to identify macrophage-derived migrasomes in CAA. Their findings demonstrated that after macrophages phagocytose Aβ, migrasomes enriched with CD5 antigen like (CD5L) are generated, exhibiting vascular adhesiveness. CD5L accumulation attenuates the host’s resistance to complement activation, resulting in complement-dependent cytotoxicity, disruption of the blood-brain barrier (BBB), and subsequent exacerbation of Aβ deposition and cerebral injury.^[70] Given the established association between migrasomes and CAA, migrasomes represent promising candidate biomarkers for the clinical detection of this condition. In central nervous system (CNS) disorders, the BBB poses a significant challenge to identifying early peripheral biochemical alterations.^[71] However, brain-resident macrophages can produce migrasomes associated with neuropathology. Future research should focus on detecting migrasome-related biomarkers in cerebrospinal fluid to provide targeted molecular evidence supporting the early diagnosis of CNS diseases such as CAA.

Traumatic brain injury (TBI) results from external mechanical forces acting directly on brain tissue. Pathology begins with primary structural damage and evolves into complex secondary injury cascades, causing transient or persistent neurological deficits.^[72] In a murine TBI model, significant neutrophil infiltration was observed surrounding the lesion. Recent studies suggest that neutrophils directly communicate with immune cells in the CNS by generating migrasomes. These migrasomes enhance neuroimmune surveillance responses,^[73] providing novel therapeutic insights for TBI treatment.

Pathological accumulation of migrasomes has been confirmed in the brain tissue of acute ischemic stroke (AIS) patients.^[12] A high-salt diet induces excessive migrasome production by microglia/macrophages, exacerbating neuronal damage and representing a novel pathological mechanism in AIS.^[12] Notably, migrasomes derived from bone marrow mesenchymal stem cells improve macrophage phagocytic capacity against bacteria, reducing post-AIS pneumonia.^[74] These findings collectively demonstrate the dual role of migrasomes in AIS pathogenesis.

Ophthalmology

Proliferative vitreoretinopathy (PVR) is a vision-threatening disorder characterized by activation of retinal pigmented epithelium (RPE) cells via transforming growth factor β (TGF-β) cytokines, causing retinal detachment and irreversible blindness.^[75] PVR treatment remains challenging. Current pharmacological interventions are mainly prophylactic, with uncertain efficacy and potential adverse effects.^[76] Although surgery remains the primary treatment, it is invasive, complex, and requires substantial expertise and advanced equipment. Wu et al. reported elevated TSPAN4 expression, a migrasome marker, in clinical PVR specimens.^[13] Further studies revealed that TGF-β1 activation upregulates TSPAN4 expression and promotes migrasome production in rat RPE cells. Mechanistically, the TGF-β1/Smad2/3 pathway mediates both TSPAN4 expression and migrasome formation in RPE cells. Therapeutically, silencing TSPAN4 reduces RPE cell fibrogenesis and significantly suppresses epiretinal membrane formation.^[13] These findings underscore the critical role of migrasomes in PVR progression. Targeting TSPAN4 or inhibiting migrasome biogenesis may thus represent a novel therapeutic strategy for PVR. The formation of pathological retinal neovascularization (RNV) is a key driver of retinal diseases, stemming from an imbalance between angiogenic stimulators and inhibitors.^[77] Although there are currently no studies directly reporting the association between migrasomes and RNV, as potential carriers of angiogenesis, migrasomes may be involved in the disease progression of RNV.

Virus transmission

Migrasomes are critical mediators of intercellular viral transmission.^[14] Upon chikungunya virus (CHIKV) infection, viral nonstructural protein 1 (nsP1) activates PIP5K1A, enhancing PI (4, 5) P₂ synthesis and modulating actin polymerization dynamics. This induces migrasome biogenesis and increases cellular motility, promoting viral spread. This represents the first evidence that migrasomes facilitate viral dissemination.^[38] Lv et al. confirmed by TEM that migrasomes encapsulate intact mpox virus particles. Mpox virus infection notably upregulates migrasome production, enabling stealth viral transport.^[15] Research indicates that the antiviral drug tecovirimat/ST-246, which targets poxvirus, failed to significantly inhibit virus-induced migrasome formation, likely due to migrasomes’ greater structural stability compared to typical EVs.^[78] Consequently, migrasomes may function as protective compartments, allowing viruses to evade common antiviral treatments and enhancing transmission efficiency and drug resistance. Additional studies identified virus-containing migrasomes in HSV-2-infected cells and murine tissues.^[55] These migrasomes efficiently transmit viruses to uninfected cells, initiating new infection cycles. Migrasome-mediated viral transmission occurs at significantly higher efficiency than conventional exocytosis. Xu et al. demonstrated that dasabuvir suppresses migrasome formation during vaccinia virus (VACV) infection, inhibiting the propagation of extracellular enveloped viruses (EEVs).^[79] Therefore, targeting virus-induced migrasome formation represents a promising strategy for novel antiviral therapeutics and warrants further investigation.

Infectious diseases

During infection and inflammation, neutrophils, acting as initial responders, are rapidly mobilized.^[80,81] Migrasome production by neutrophils increases dramatically, suggesting migrasome generation is integral to the immune response during infection or inflammation.^[4] Upon lipopolysaccharide (LPS) stimulation, monocytes utilize a migrasome-dependent pathway to secrete inflammatory cytokines, achieving substantially higher release compared to classical exocytosis.^[74] These cytokine-loaded migrasomes rapidly accumulate at inflammation sites, forming localized signaling centers. This highlights migrasomes as a novel cytokine delivery mechanism and potential therapeutic targets for immunomodulation and inflammatory disease treatment. Additionally, migrasome-deficient mice exhibit reduced acute inflammation and improved survival after toxin challenge, further supporting the role of migrasomes in early immune responses.^[20] Consequently, migrasomes represent promising therapeutic targets and early diagnostic markers for related pathologies.

Respiratory medicine

Sepsis-associated pulmonary fibrosis (SAPF) is a critical pathology in acute respiratory distress syndrome induced by sepsis.^[82,83] Peng et al. demonstrated that migrasomes mediate macrophage-to-myofibroblast transition (MMT) in LPS-induced SAPF mouse models and fibroblast-macrophage co-culture systems.^[84] PGC-1α promotes migrasome biogenesis, facilitating profibrotic signaling and driving fibrosis in SAPF. This study identifies migrasomes as potential therapeutic targets for SAPF.^[84]

Cardiology

Migrasomes regulate cardiovascular diseases. Studies indicate that TSPAN4, a migrasome marker, is significantly upregulated in myocardial infarction mouse models and associated with pathological processes such as macrophage enrichment and intra-plaque hemorrhage,^[16] suggesting migrasome involvement in atherosclerosis. Targeting TSPAN4-mediated migrasome formation may thus provide a novel therapeutic strategy for atherosclerosis. Zhang et al. further demonstrated that endothelial cell-derived migrasomes promote macrophage polarization toward the pro-inflammatory M1 phenotype, accelerating atherosclerosis.^[17] Migrasome expression positively correlates with disease severity in advanced-stage patients.^[17] Thus, targeting TSPAN4 and migrasome pathways may slow atherosclerosis progression.

Sun et al. used a mouse model of myocardial ischemia-reperfusion injury (MIRI) to demonstrate that low-intensity pulsed ultrasound (LIPUS) alleviates MIRI-induced mitochondrial dysfunction.^[85] Mechanistically, LIPUS activates the RhoA/myosin II/F-actin signaling pathway, inducing migrasome formation to expel damaged mitochondria. This process mitigates mitochondrial dysfunction, thereby improving cardiac function.^[85] Thus, migrasome-mediated mitochondrial quality control exerts cardioprotective effects in MIRI, providing novel avenues for non-invasive cardiac protection strategies. Zhu et al. combined machine learning with single-cell RNA sequencing, Mendelian randomization, and molecular docking techniques to develop migrasome-related signatures predicting acute myocardial infarction risk.^[86] They identified a significant positive causal relationship between migrasome-related gene ITGB1 expression and acute myocardial infarction risk.^[86] Migrasome-mediated mitochondrial quality control may sustain cardiovascular mitochondrial homeostasis, suggesting potential therapeutic strategies for cardiovascular diseases.^[87] However, clear in vivo evidence remains lacking, and further research is needed.

Regenerative medicine

Migrasomes exhibit unique biological functions in regenerative medicine.^[19] Studies show that adipose‑derived stem cells (ASCs) establish a chemotactic gradient by secreting CXCL12‑rich migrasomes, which activate the CXCR4/RhoA signaling axis to drive stem cell migration and create a pro‑regenerative microenvironment. This process significantly improves soft tissue regeneration efficiency.^[19] These findings indicate that ASC‑derived migrasomes restore tissue regeneration by recruiting stem cells. As a novel therapeutic target in ASC‑mediated regeneration, migrasomes offer potential intervention strategies for regenerative medicine. In bone regeneration, Li et al. confirmed that M2 macrophage‑derived migrasomes carry osteogenic differentiation‑inducing factors.^[88] Migrasomes collected from M2 macrophages using a titanium dioxide nanotube surface enhance the osteogenic differentiation potential of mesenchymal stem cells (MSCs), thereby promoting new bone formation in defect models. Coating titanium surfaces with migrasomes further enhances osteogenesis.^[88] Thus, nano‑surfaces may function as platforms for migrasome production, offering new approaches for tissue regeneration.

Wound healing

Migrasome biogenesis declines markedly during skin aging. Migrasomes derived from young fibroblasts reverse senescent phenotypes in aged keratinocytes and accelerate wound healing in aged skin.^[18] Single‑cell RNA sequencing (scRNA‑seq) reveals peak transcriptional heterogeneity in fibroblasts during aging, with senescence levels inversely correlating with migrasome marker expression. Multiplex immunohistochemistry (mIHC) and TEM confirm significantly higher migrasome density in skin samples from young donors (mice/humans) compared with aged counterparts.^[18] In naturally aged mouse models, exogenous young fibroblast‑derived migrasomes accelerate wound closure and suppress senescence‑associated marker expression.^[18] As novel intercellular communication vectors, migrasomes exhibit dual therapeutic capacities. They function as natural repair engines that accelerate wound healing and as rejuvenation signal hubs that reverse keratinocyte aging. This strategy enables simultaneous senescent cell clearance and tissue regeneration, offering transformative potential for geriatric chronic wound treatment.

Isolation and purification of migrasomes

Methods for isolating and purifying migrasomes include differential centrifugation and density gradient centrifugation. These techniques effectively minimize contamination from cell bodies, apoptotic bodies, and exosomes, resulting in purified migrasome fractions. Yu et al. adapted extracellular vesicle isolation strategies, combining differential centrifugation with density gradient centrifugation, to enrich migrasomes from biological samples (e.g., body fluids or conditioned media).^[89] Notably, this protocol uses Optiprep rather than sucrose as the density medium, preserving migrasome structural integrity through optimized isopycnic centrifugation parameters.^[90] In this method, cells are digested with 0.25% trypsin [neutralized with 10% fetal bovine serum (FBS)], followed by differential centrifugation: low-speed steps at 1000×g for 10 min and 4000×g for 20 min (4 ° C) to remove cell debris, and high-speed centrifugation at 20,000×g for 60 min (4 °C). Density gradient centrifugation is then employed for further purification.^[39,88] Saito et al. demonstrated that cell-penetrating peptides (e.g., pVEC, R9) and viral fusion peptides (e.g., SIV) enhance migrasome biogenesis by promoting cell migration, offering novel strategies for functional enrichment studies.^[91] Ma et al. developed a pipeline combining hierarchical filtration with ultracentrifugation: initial debris removal using a 0.45-μm filter, migrasome capture via reverse membrane extrusion, and enrichment of high-purity migrasome-derived nanoparticles (MDNPs) through ultracentrifugation at 100,000×g.^[90] Although isolated migrasomes are highly enriched, they are not absolutely pure. Due to this inherent limitation, rigorous quality control is essential before conducting functional studies. Techniques such as Western blotting, mass spectrometry, wheat germ agglutinin (WGA) staining, and electron microscopy are useful for migrasome identification and functional characterization.

Migrasome Labeling Methods

Early migrasome studies identified key markers (e.g., TSPAN4, TSPAN9, integrin α5).^[1] Migrasomes can be visualized by labeling these markers with green fluorescent protein or mCherry; however, this approach involves prolonged protocols, high cost, and potential interference with migrasome biogenesis due to protein overexpression.^[1,3,92] The WGA dye labeling method rapidly labels cell lines and chicken embryos by binding N-acetylneuraminic acid and N-acetylglucosamine, but its efficacy is limited in zebrafish and mice.^[93] Liang et al. demonstrated that SMS2 forms SM-enriched microdomains at the leading edge of migrating cells, determining MFSs. Non-toxic lysenin (NT-Lys), which specifically binds membrane SM, effectively labels migrasomes in vitro, but its applicability for in vivo labeling remains unexplored.^[27] Cui et al. developed an aggregation-induced emission (AIE)-based near-infrared probe, TTCPy, specifically binding migrasome phospholipids to enable rapid fluorescent labeling.^[93] TTCPy permits high-resolution imaging of migrasomes in live cells and CAM, and it supports super-resolution microscopy for enhanced spatial contrast.^[93] Additionally, Yang et al. established a magnetic bead-based assay combining WGA-coated beads with flow cytometry for efficient migrasome isolation and quantification.^[11] This method quantitatively compares migrasome levels in urine samples from healthy donors and nephropathy patients, demonstrating potential applicability in diverse liquid biopsies (e.g., cell culture media, serum, urine) and clinical translation.^[11] However, due to the extremely low abundance of migrasomes in body fluids (such as blood and urine), false-negative results are very likely to occur in routine tests, which severely limits their clinical application potential as disease biomarkers. To overcome this technical bottleneck, in the future, a microfluidic enrichment platform can be used to efficiently capture and concentrate migrasomes. At the same time, combined with a capture strategy based on specific antibodies or affinity ligands, the sensitivity and reliability of detection can be significantly improved, thereby promoting the practical application of migrasomes in the field of non-invasive diagnosis. Migrasome research depends on dynamic tracing and observation techniques. Therefore, developing more efficient, convenient, and specific methods for migrasome labeling and visualization represents a major ongoing challenge that requires continuous exploration and refinement.

Morphological observation of migrasomes

Optical and electron microscopy techniques enable the observation, detection, and characterization of migrasomes. As early as 1963, Taylor et al. used TEM to observe contractile filaments produced by migrating cells.^[94] Correlative light-electron microscopy (CLEM) has revealed migrasomes as vesicle-like structures enclosed by a single-layer membrane containing multiple smaller vesicles.^[1] Researchers first successfully observed migrasome formation in living cells using confocal microscopy-based live-cell imaging technology.^[3] Developing an in vivo imaging system to monitor migrasome dynamics in mice is a current research priority. However, traditional spinning-disk confocal microscopy provides insufficient spatiotemporal resolution and higher phototoxicity, limiting its application in migrasome research.

Jiang et al. used fluorescently conjugated antibodies combined with flow cytometry to specifically label cell-surface proteins.^[39] This method rapidly labels migrasomes in real-time, enabling in vivo observation in live mice and facilitating exploration of migrasome functions in physiological processes. Yu Li et al., in collaboration with Prof. Dai Qionghai’s team at Tsinghua University, developed Digital Adaptive Optics Scanning Light-field Mutual Iterative Tomography (DAOSLIMIT) technology.^[95] Using a scanning light-field microscope, they observed migrasome production by neutrophils and tumor cells at enhanced spatiotemporal resolution through a hepatic observation window.^[95] Recently, Prof. Dai Qionghai’s team developed two-photon synthetic aperture microscopy (2pSAM), employing a needle-like beam for high-speed scanning.^[73] This technique reduces cellular phototoxicity and provides superior spatial resolution compared to conventional methods. Applying 2pSAM, they documented migrasome production by neutrophils in the cortex of TBI mice.^[73]