Directional cell movement through tissues is controlled by exosome secretion

Advances in therapies using mesenchymal stem cells and their exosomes for treatment of peripheral nerve injury: state of the art and future perspectives

"Peripheral nerve injury" refers to damage or trauma affecting nerves outside the brain and spinal cord. Peripheral nerve injury results in movements or sensation impairments, and represents a serious public health problem. Although severed peripheral nerves have been effectively joined and various therapies have been offered, recovery of sensory or motor functions remains limited, and efficacious therapies for complete repair of a nerve injury remain elusive. The emerging field of mesenchymal stem cells and their exosome-based therapies hold promise for enhancing nerve regeneration and function. Mesenchymal stem cells, as large living cells responsive to the environment, secrete various factors and exosomes. The latter are nano-sized extracellular vesicles containing bioactive molecules such as proteins, microRNA, and messenger RNA derived from parent mesenchymal stem cells. Exosomes have pivotal roles in cell-to-cell communication and nervous tissue function, offering solutions to changes associated with cell-based therapies. Despite ongoing investigations, mesenchymal stem cells and mesenchymal stem cell-derived exosome-based therapies are in the exploratory stage. A comprehensive review of the latest preclinical experiments and clinical trials is essential for deep understanding of therapeutic strategies and for facilitating clinical translation. This review initially explores current investigations of mesenchymal stem cells and mesenchymal stem cell-derived exosomes in peripheral nerve injury, exploring the underlying mechanisms. Subsequently, it provides an overview of the current status of mesenchymal stem cell and exosome-based therapies in clinical trials, followed by a comparative analysis of therapies utilizing mesenchymal stem cells and exosomes. Finally, the review addresses the limitations and challenges associated with use of mesenchymal stem cell-derived exosomes, offering potential solutions and guiding future directions.

Extracellular vesicles as cancer biomarkers and drug delivery strategies in clinical settings: Advances, perspectives, and challenges

Cancer is a leading cause of death worldwide, and despite the introduction of new therapeutic approaches for advanced cases aimed at improving patient survival, only a subset of patients benefits from a complete response. In this context, there is a growing need for new cancer biomarkers and therapeutic strategies, and the use of Extracellular Vesicles (EVs) has been widely explored in various approaches. As circulating lipid-bilayer particles carrying a variety of biological information from tumor cells, EVs can be employed as good biomarkers of diagnosis, prognosis, therapy evaluation, and as adjuvants in cancer treatment. In this review, we provide a brief overview of the different types of EVs and their biogenesis and discuss how tumor-derived EV cargo can serve as a potential biomarker in clinical settings through liquid biopsy. We also highlight recent advances in EV nanoengineering and their potential as adjuvants in cancer treatment. Finally, we discuss the key unknowns, gaps, and bottlenecks that must be addressed to fully integrate EVs into precision oncology.

1,4-Dioxane Induces Epithelial-Mesenchymal Transition and Carcinogenesis in an Nrf2-Dependent Manner

The carcinogenic potential of the environmental pollutant 1,4-dioxane (1,4-D) in humans is not yet fully understood or recognised. In this study, we provide evidence that 1,4-D acts as a carcinogen in human epithelial cells. Using the human bronchial epithelial cell line BEAS-2B, with or without CRISPR-Cas9-mediated Nrf2 knockout, we demonstrate that continuous exposure to environmentally relevant concentrations of 1.25-20 ppm 1,4-D over 2 months induces malignant transformation in an Nrf2-dependent manner. Transformed cells exhibit enhanced anchorage-independent growth in soft agar, increased migration and invasion, and tumorigenic potential in a xenograft mouse model. Integrated RNA sequencing and proteomics analyses reveal that 1,4-D robustly activates Nrf2 signalling, driving extracellular vesicle (EV) biogenesis and cargo loading with syndecan 4 (SDC4) and other proteins, including COL12A1, CAPG and NNMT, which are associated with epithelial-mesenchymal transition (EMT) and cancer metastasis. Nrf2 knockout reduces SDC4 expression and its incorporation into EVs, leading to decreased EV uptake by recipient cells. Unlike EVs from 1,4-D-transformed WT cells, which enhance the proliferation, migration and invasion of recipient cells, EVs from 1,4-D-transformed Nrf2 KO cells exhibit a diminished capacity to promote these EMT properties. Furthermore, we demonstrate that the Nrf2 target gene SDC4, induced by 1,4-D and enriched in EVs, plays a critical role in EV uptake by recipient cells, thereby facilitating EMT propagation. Collectively, our findings suggest that 1,4-D is a human carcinogen, with its carcinogenicity largely dependent on Nrf2 activation, which orchestrates the biogenesis of EVs with EMT-promoting functions.

Extracellular membrane particles en route to the nucleus - exploring the VOR complex

Intercellular communication is an essential hallmark of multicellular organisms for their development and adult tissue homeostasis. Over the past two decades, attention has been focused on communication mechanisms based on various membrane structures, as illustrated by the burst of scientific literature in the field of extracellular vesicles (EVs). These lipid bilayer-bound nano- or microparticles, as vehicle-like devices, act as regulators in various biological and physiological processes. When EVs are internalized by recipient cells, their membrane and cytoplasmic cargoes can interfere with cellular activities, affecting pathways that regulate cell proliferation, differentiation, and migration. In cancer, EVs can transfer oncogenic factors, stimulate neo-angiogenesis and immunosuppression, reprogram stromal cells, and confer drug resistance traits, thereby remodeling the surrounding microenvironment. Although the mechanisms underlying EV biogenesis and uptake are now better understood, little is known about the spatiotemporal mechanism(s) of their actions after internalization. In this respect, we have shown that a fraction of endocytosed EVs reaches the nuclear compartment via the VOR (VAP-A-ORP3-Rab7) complex-mediated docking of late endosomes to the outer nuclear membrane in the nucleoplasmic reticulum, positioning and facilitating the transfer of EV cargoes into the nucleoplasm via nuclear pores. Here, we highlight the EV heterogeneity, the cellular pathways governing EV release and uptake by donor and recipient cells, respectively, and focus on a novel intracellular pathway leading to the nuclear transfer of EV cargoes. We will discuss how to intercept it, which could open up new avenues for clinical applications in which EVs and other small extracellular particles (e.g., retroviruses) are implicated.

Extracellular vesicles as the common denominator among the 7 Rs of radiobiology: From the cellular level to clinical practice

Extracellular vesicles (EVs) are lipid-bound particles released by tumor cells and widely explored in cancer development, progression, and treatment response, being considered as valuable components to be explored as biomarkers or cellular targets to modulate the effect of therapies. The mechanisms underlying the production and profile of EVs during radiotherapy (RT) require addressing radiobiological aspects to determine cellular responses to specific radiation doses and fractionation. In this review, we explore the role of EVs in the 7 Rs of radiobiology, known as the molecular basis of a biological tissue response to radiation, supporting EVs as a shared player in all the seven processes. We also highlight the relevance of EVs in the context of liquid biopsy and resistance to immunotherapy, aiming to establish the connection and utility of EVs as tools in contemporary and precision radiotherapy.

P, Danieli-Mackay A, Lenz C, Brockmeyer P, Gross JC. The Ceramide-Dependent EV Secretome Differentially Affects Prostate Cancer Cell Migration

Tumor-derived extracellular vesicles (EVs) play an important role in cancer progression. Neutral sphingomyelinases (nSMases) are lipid-modifying enzymes that modulate the secretion of EVs from cells. How nSMase activity and therefore ceramide generation affect the composition and functionality of secreted EVs is not fully understood. Here, we aimed to investigate the expression of nSMases 1 and 2 in prostate cancer (PCa) tissue and their role in EV composition and secretion for prostate cancer cell migration. Reduced nSMase 1 and 2 expression was found in prostate cancer and correlated with the age of the patient. When nSMase 2 was inhibited by GW4869 in PCa cells (PC3 and DU145), the EV secretome was significantly altered, while the number of EVs and the total protein content of released EVs were not significantly changed. Using proteomic analysis, we found that extracellular matrix proteins, such as SDC4 (Syndecan-4) and SRPX-2, were differentially secreted on EVs from GW4869-treated PC3 cells. In scratch wound migration assays, GW4869 significantly increased migration compared to control PC3 cells but not DU145 cells, while SDC4 knockdown significantly reduced the migration of PC3 cells. These and other nSMase-2-dependent secreted proteins are interesting candidates for understanding the role of stress-induced EVs in the progression of prostate cancer.

ECM-binding properties of extracellular vesicles: advanced delivery strategies for therapeutic applications in bone and joint diseases

Extracellular vesicles (EVs) and the extracellular matrix (ECM) are essential in maintaining bone and joint health by facilitating intercellular communication, regulating tissue processes and providing structural support. EVs with a large surface area carry diverse biomolecules to steer the function of cells in their surroundings. To understand how EVs localize to specific sites, we here review the available knowledge on EV surface biomolecules and their interactions with ECM components that are crucial for regulating bone remodeling, cartilage maintenance, and immune responses, playing roles in both tissue homeostasis and pathological conditions, such as arthritis and osteoporosis. More importantly, using analyses of animal experimental data, we illustrate the effect of ECM-based biomaterials (e.g. hydrogels, decellularized matrices, and ECM-mimetic scaffolds) as carriers for EVs toward effective EV delivery in regenerative and immunomodulatory therapies in bone and joint tissue. These biomaterials enable sustained release and targeted delivery of EVs, promoting bone and cartilage regeneration. The insights of this review can be utilized to advance the development of cutting-edge therapies for skeletal tissue regeneration and disease management.

Decoding the MMP14 integrin link: Key player in the secretome landscape

Rapid progress has been made in the exciting field of secretome research in health and disease. The tumor secretome, which is a significant proportion of the tumor proteome, is secreted into the extracellular space to promote intercellular communication and thus tumor progression. Among the many molecules of the secretome, integrins and matrix metalloproteinase 14 (MMP14) stand out as the interplay of adhesion and proteolysis drives invasion. Integrins serve as mechanosensors that mediate the contact of cells with the scaffold of the extracellular matrix and are significantly involved in the precise positioning and activity control of the membrane-bound collagenase MMP14. As a secretome proteinase, MMP14 influences and modifies the secretome itself. While integrins and MT-MMPs are membrane bound, but can be released and are therefore border crossers between the cell surface and the secretome, the extracellular matrix is not constitutively cell-bound, but its binding to integrins and other cell receptors is a stringently regulated process. To understand the mutual interactions in detail, we first summarize the structure and function of MMP14 and how it is regulated at the enzymatic and cellular level. In particular, the mutual interactions between integrins and MMP14 include the proteolytic cleavage of integrins themselves by MMP14. We then review the biochemical, cell biological and physiological effects of MMP14 on the composition and associated functions in the tumor secretome when either bound to the cell membrane, or located on extracellular microvesicles, or as a proteolytically shed non-membrane-bound ectodomain. Novel methods of proteomics, including the analysis of extravesicular vesicles, and new methods for the quantification of MMP14 will provide new research and diagnostic tools. The proteolytic modification of the tumor secretome, especially by MMP14, may bring an additional aspect to tumor secretome studies and will have an impact on the diagnosis and most likely also on the therapy of cancer patients.

Secreted exosomes induce filopodia formation

Filopodia are dynamic adhesive cytoskeletal structures that are critical for directional sensing, polarization, cell-cell adhesion, and migration of diverse cell types. Filopodia are also critical for neuronal synapse formation. While dynamic rearrangement of the actin cytoskeleton is known to be critical for filopodia biogenesis, little is known about the upstream extracellular signals. Here, we identify secreted exosomes as potent regulators of filopodia formation. Inhibition of exosome secretion inhibited the formation and stabilization of filopodia in both cancer cells and neurons and inhibited subsequent synapse formation by neurons. Rescue experiments with purified small and large extracellular vesicles (EVs) identified exosome-enriched small EVs (SEVs) as having potent filopodia-inducing activity. Proteomic analyses of cancer cell-derived SEVs identified the TGF-β family coreceptor endoglin as a key SEV-enriched cargo that regulates filopodia. Cancer cell endoglin levels also affected filopodia-dependent behaviors, including metastasis of cancer cells in chick embryos and 3D migration in collagen gels. As neurons do not express endoglin, we performed a second proteomics experiment to identify SEV cargoes regulated by endoglin that might promote filopodia in both cell types. We discovered a single SEV cargo that was altered in endoglin-KD cancer SEVs, the transmembrane protein Thrombospondin Type 1 Domain Containing 7A (THSD7A). We further found that both cancer cell and neuronal SEVs carry THSD7A and that add-back of purified THSD7A is sufficient to rescue filopodia defects of both endoglin-KD cancer cells and exosome-inhibited neurons. We also find that THSD7A induces filopodia formation through activation of the Rho GTPase, Cdc42. These findings suggest a new model for filopodia formation, triggered by exosomes carrying THSD7A.

Mesenchymal Stem Cell-Derived Small Extracellular Vesicle as A Novel Therapeutic Approach for Chemotherapy-Induced Male Infertility: A Review Article

Small extracellular vesicles (sEVs) have been recognized as a promising therapeutic modality due to their low immunogenicity, and the ability to penetrate biological barriers. They contain significant amounts of lipids, proteins, and microRNAs, effectively participating in intra- and inter-cellular communications. sEVs derived from mesenchymal stem cells (MSCs) are being explored as a potential therapeutic option due to their immunomodulatory, anti-inflammatory, antioxidant, and regenerative properties, offering advantages over stem cell transplantationbased treatments. Chemotherapy induces side effects on various organs, particularly those with high proliferative capacity, such as testicular tissue. Exposure to some groups of chemotherapeutic agents, such as cyclophosphamide, cisplatin, and doxorubicin can cause DNA damage and induce apoptosis in spermatogonia and primary spermatocytes. Chemotherapy has been shown to induce cellular stress in testicles, leading to testicular dysfunction and the activation of apoptotic pathways in response to external and internal stress. The current research aims to review the potential therapeutic advantages of sEVs derived from MSCs in addressing sperm abnormalities and male infertility resulting from chemotherapy. Several lines of evidence indicate that treatment with sEVs can reduce testicular tissue damage caused by chemotherapy by decreasing oxidative stress and inflammatory responses. sEVs boost the growth and motility of spermatogenic cells and protect them from apoptosis by activating internal pathways. Therefore, as a non-invasive approach, they have shown promising results in regenerating damaged spermatozoa and restoring spermatogenesis.

Focal adhesion in the tumour metastasis: from molecular mechanisms to therapeutic targets

The tumour microenvironment is the "hotbed" of tumour cells, providing abundant extracellular support for growth and metastasis. However, the tumour microenvironment is not static and is constantly remodelled by a variety of cellular components, including tumour cells, through mechanical, biological and chemical means to promote metastasis. Focal adhesion plays an important role in cell-extracellular matrix adhesion. An in-depth exploration of the role of focal adhesion in tumour metastasis, especially their contribution at the biomechanical level, is an important direction of current research. In this review, we first summarize the assembly of focal adhesions and explore their kinetics in tumour cells. Then, we describe in detail the role of focal adhesion in various stages of tumour metastasis, especially its key functions in cell migration, invasion, and matrix remodelling. Finally, we describe the anti-tumour strategies targeting focal adhesion and the current progress in the development of some inhibitors against focal adhesion proteins. In this paper, we summarize for the first time that focal adhesion play a positive feedback role in pro-tumour metastatic matrix remodelling by summarizing the five processes of focal adhesion assembly in a multidimensional way. It is beneficial for researchers to have a deeper understanding of the role of focal adhesion in the biological behaviour of tumour metastasis and the potential of focal adhesion as a therapeutic target, providing new ideas for the prevention and treatment of metastases.

Cortactin Facilitates Malignant Transformation of Dysplastic Cells in Gastric Cancer Development

BACKGROUND & AIMS

Epithelial cancer onset occurs through sequential stages of cell lineage conversion and functional dysregulation. Dysplasia is a precancerous lesion defined as a direct precursor to cancer and is histologically defined as a transition stage between pre-cancer and cancer, but molecular and biological mechanisms controlling its transformation to malignancy are underdetermined. Here, we discover the crucial role of the actin stabilization and exosome secretion-regulatory protein cortactin in dysplastic cell transformation to adenocarcinoma.

METHODS

We engineered a CRISPR/Cas9-based cortactin knock-out (KO) dysplasia organoid model established from dysplastic tissue and examined malignant roles of cortactin during gastric cancer development in vitro and in vivo.

RESULTS

Although dysplastic cell identity remained unchanged, the cortactin KO organoids exhibited a decrease in cellular organization and multicellular protrusions, which are considered aggressive features when observed in vitro. When injected into the flank of nude mice, cortactin KO cells failed malignant transformation into adenocarcinoma and solid tumor formation with reduced recruitment of fibroblasts and macrophages. In addition, cortactin KO cells showed diminished exosome secretion levels, and adenocarcinoma development was impaired when exosome secretion was inhibited in cortactin wild-type dysplastic cells.

CONCLUSIONS

These data suggest that cortactin is a functional element of membrane dynamics, malignant changes, and exosome secretion in dysplastic cells, and solid gastric tumor formation associated with alteration of the tumor microenvironment.

Exosomes: a double-edged sword in cancer immunotherapy

Over the past few decades, immunotherapy has emerged as a powerful strategy to overcome the limitations of conventional cancer treatments. The use of extracellular vesicles, particularly exosomes, which carry cargoes capable of modulating the immune response, has been extensively explored as a potential therapeutic approach in cancer immunotherapy. Exosomes can deliver their cargo to target cells, thereby influencing their phenotype and immunomodulatory functions. They exhibit either immunosuppressive or immune-activating characteristics, depending on their internal contents. These exosomes originate from diverse cell sources, and their internal contents can vary, suggesting that there may be a delicate balance between immune suppression and stimulation when utilizing them for immunotherapy. Therefore, a thorough understanding of the molecular mechanisms underlying the role of exosomes in cancer progression is essential. This review focuses on the molecular mechanisms driving exosome function and their impact on the tumor microenvironment (TME), highlighting the intricate balance between immune suppression and activation that must be navigated in exosome-based therapies. Additionally, it underscores the challenges and ongoing efforts to optimize exosome-based immunotherapies, thereby making a significant contribution to the advancement of cancer immunotherapy research.

Extracellular vesicles support increased expansion of mesenchymal stromal cells on fetal membrane-derived decellularized extracellular matrix

Decidual mesenchymal stromal cells (DMSC) were the source of extracellular vesicles (DMSC_EV). The xCELLigence real-time cell growth assay revealed increasing concentrations of EVs decreased DMSC attachment in the early growth phase but stimulated DMSC proliferation at day 7 when grown on tissue culture plastic (TCP). DMSC attachment and proliferation varied depending on the growth surface and DMSC_EV supplementation. DMSC attachment increased on decellularized and solubilized amniotic (s-dAM) whether or not EVs were added. Only Matrigel substrate increased DMSC attachment with added EVs. The addition of EVs increased DMSC proliferation only on the s-dAM substrate. DMSCs were more motile on s-dAM and decellularized and solubilized chorionic (s-dCM) membranes following EV addition. The osteogenic potential of DMSCs was improved on s-dAM substrates when supplanted with EVs. Finally, the levels of reactive oxygen species in DMSCs varied depending on the substrate but not on added EVs. We show that the addition of in vitro EVs isolated from the source being expanded (i.e., DMSCs) and the presence of ECM improve DMSC behaviours during ex vivo expansion. The inclusion of two key components of the MSC niche, EVs and ECM, benefitted the ex vivo expansion of MSCs. Added in vitro EVs increased the proliferation of DMSCs when grown on s-dAM but not on s-dCM, whereas they improved DMSC mobility on both surfaces. Testing different ECMs could be used to promote specific desired characteristics of DMSCs, and different combinations of EVs and ECM may enhance desirable MSC characteristics for specific therapeutic settings.

Leveraging nature's nanocarriers: Translating insights from extracellular vesicles to biomimetic synthetic vesicles for biomedical applications

Naturally occurring extracellular vesicles (EVs) and synthetic nanoparticles like liposomes have revolutionized precision diagnostics and medicine. EVs excel in biocompatibility and cell targeting, while liposomes offer enhanced drug loading capacity and scalability. The clinical translation of EVs is hindered by challenges including low yield and heterogeneity, whereas liposomes face rapid immune clearance and limited targeting efficiency. To bridge these gaps, biomimetic synthetic vesicles (SVs) have emerged as innovative platforms, combining the advantageous properties of EVs and liposomes. This review emphasizes critical aspects of EV biology, such as mechanisms of EV-cell interaction and source-dependent functionalities in targeting, immune modulation, and tissue regeneration, informing biomimetic SV engineering. We reviewed a broad array of biomimetic SVs, with a focus on lipid bilayered vesicles functionalized with proteins. These include cell-derived nanovesicles, protein-functionalized liposomes, and hybrid vesicles. By addressing current challenges and highlighting opportunities, this review aims to advance biomimetic SVs for transformative biomedical applications.

Label-Free SERS Analysis of Biological and Physical Information Heterogeneity of Nanoscale Extracellular Vesicle by Matching Specific Sizes of Enhanced Particles

The heterogeneity of extracellular vesicles (EVs) surface information represents different functions, which is neglected in previous studies. In this study, a label-free SERS analysis approach is demonstrated to study fundamental EV biological and physical information heterogeneity by matching specific sizes of nano-enhanced particles. This strategy reveals informative, comprehensive, and high-quality SERS spectra of the overall exosome surface, and effectively circumvents the key information loss caused by the spatial resistance of NPs binding to the 293 exosomes' concave structure. The classification of normal and cancerous cell-derived exosomes by PCA method, the accuracy is improved from 91.2% to 95.1% by optimizing sizes of nano-enhanced particles. In addition, stem cell-derived EVs of diverse sizes and morphologies similarly show acuity of spectrum variation to NPs size, which is conductive to qualitative studies. This new strategy will offer a widened in-depth understanding of the surface information, size, and morphology of EVs, which can be applied to the study of biological functions.

The role and regulation of integrins in cell migration and invasion

Integrin receptors are the main molecular link between cells and the extracellular matrix (ECM) as well as mediating cell-cell interactions. Integrin-ECM binding triggers the formation of heterogeneous multi-protein assemblies termed integrin adhesion complexes (IACs) that enable integrins to transform extracellular cues into intracellular signals that affect many cellular processes, especially cell motility. Cell migration is essential for diverse physiological and pathological processes and is dysregulated in cancer to favour cell invasion and metastasis. Here, we discuss recent findings on the role of integrins in cell migration with a focus on cancer cell dissemination. We review how integrins regulate the spatial distribution and dynamics of different IACs, covering classical focal adhesions, emerging adhesion types and adhesion regulation. We discuss the diverse roles integrins have during cancer progression from cell migration across varied ECM landscapes to breaching barriers such as the basement membrane, and eventual colonization of distant organs.

Engineered Extracellular Vesicles as a New Class of Nanomedicine

Extracellular vesicles (EVs) are secreted from biological cells and contain many molecules with diagnostic values or therapeutic functions. There has been great interest in academic and industrial communities to utilize EVs as tools for diagnosis or therapeutics. In addition, EVs can also serve as delivery vehicles for therapeutic molecules. An indicator of the enormous interest in EVs is the large number of review articles published on EVs, with the focus ranging from their biology to their applications. An emerging trend in EV research is to produce and utilize "engineered EVs", which are essentially the enhanced version of EVs. EV engineering can be conducted by cell culture condition control, genetic engineering, or chemical engineering. Given their nanometer-scale sizes and therapeutic potentials, engineered EVs are an emerging class of nanomedicines. So far, an overwhelming majority of the research on engineered EVs is preclinical studies; there are only a very small number of reported clinical trials. This Review focuses on engineered EVs, with a more specific focus being their applications in therapeutics. The various approaches to producing engineered EVs and their applications in various diseases are reviewed. Furthermore, in vivo imaging of EVs, the mechanistic understandings, and the clinical translation aspects are discussed. The discussion is primarily on preclinical studies while briefly mentioning the clinical trials. With continued interdisciplinary research efforts from biologists, pharmacists, physicians, bioengineers, and chemical engineers, engineered EVs could become a powerful solution for many major diseases such as neurological, immunological, and cardiovascular diseases.

Matrix stiffness modulated release of spheroid-derived extracellular vesicles and discovery of Piezo1 cargo

Augmented extracellular matrix (ECM) stiffness is a mechanical hallmark of cancer. Mechanotransduction studies have extensively probed the mechanisms by which ECM stiffness regulates intracellular communication. However, the influence of stiffness on intercellular communication aiding tumor progression in three-dimensional microenvironments remains unknown. Small extracellular vesicles (EVs) are communicators of altered biophysical cues to distant sites through EV-ECM interactions and EV-mediated recipient cell-ECM interactions. Here we demonstrate stiffness-mediated modulation of small EVs secretion and cargo from three-dimensional oral squamous cell carcinoma spheroids. Using a spheroid culture platform with varying matrix stiffness properties, we show that small EVs carry parental biomolecular cargo, including mechanosensitive Piezo1 ion channel and adhesion molecule CD44. We comprehensively validate the presence of both markers in our EV populations using proteomic and genetic analysis. Transcriptomic analysis of microRNA and long non-coding RNA cargo of small EVs released from soft and stiff ECM spheroids revealed enrichment of tumorigenic and metastatic profiles in EVs from stiff ECM cultures compared to that of soft ones. Gene set enrichment analysis of a comparative dataset obtained by overlaying spheroid mRNA and EV miRNA profiles identified key oncogenic pathways involved in cell-EV crosstalk in the spheroid model.

Profiling signaling mediators for cell-cell interactions and communications with microfluidics-based single-cell analysis tools

Cell-cell interactions and communication represent the fundamental cornerstone of cells' collaborative efforts in executing diverse biological processes. A profound understanding of how cells interface through various mediators is pivotal across a spectrum of biological systems. Recent strides in microfluidic technologies have significantly bolstered the precision and prowess in capturing and manipulating cells with exceptional spatial and temporal resolution. These advanced methodologies converge with multi-signal mediator detection systems, furnishing potent, high-throughput platforms for dissecting cell-cell interactions at the single-cell level. This approach empowers researchers to delve into intricate cellular dynamics with unprecedented accuracy and efficiency. Here, we present a critical evaluation of the latest advancements in microfluidics-driven techniques for detecting signal mediators involved in cell-cell interactions and communication at the single-cell level. We underscore notable biological applications that have benefited from these technologies and identify pressing challenges that must be addressed in future endeavors leveraging microfluidic tools for single-cell interaction studies.

Unveiling the complex double-edged sword role of exosomes in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignancy arising from the epithelium of the nasopharynx. Given its late diagnosis, NPC raises serious considerations in Southeast Asia. In addition to resistance to conventional treatment that combines chemotherapy and radiation, NPC has high rates of metastasis and frequent recurrence. Exosomes are small membrane vesicles at the nanoscale that transport physiologically active compounds from their source cell and have a crucial function in signal transmission and intercellular message exchange. The exosomes detected in the tissues of NPC patients have recently emerged as a potential non-invasive liquid biopsy biomarker that plays a role in controlling the tumor pathophysiology. Here, we take a look back at what we know so far about the complex double-edged sword role of exosomes in NPC. Exosomes could serve as biomarkers and therapeutic agents, as well as the molecular mechanisms by which they promote cell growth, angiogenesis, metastasis, immunosuppression, radiation resistance, and chemotherapy resistance in NPC. Furthermore, we go over some of the difficulties and restrictions associated with exosome use. It is anticipated that this article would provide the reference for the apply of exosomes in clinical practice.

Extracellular vesicles as emerging players in glaucoma: Mechanisms, biomarkers, and therapeutic targets

In recent years, extracellular vesicles (EVs) have attracted significant scientific interest due to their widespread distribution, their potential as disease biomarkers, and their promising applications in therapy. Encapsulated by lipid bilayers these nanovesicles include small extracellular vesicles (sEV) (30-150 nm), microvesicles (100-1000 nm), and apoptotic bodies (100-5000 nm) and are essential for cellular communication, immune responses, biomolecular transport, and physiological regulation. As they reflect the condition and functionality of their originating cells, EVs play critical roles in numerous physiological processes and diseases. Therefore, EVs offer valuable opportunities for uncovering disease mechanisms, enhancing drug delivery systems, and identifying novel biomarkers. In the context of glaucoma, a leading cause of irreversible blindness, the specific roles of EVs are still largely unexplored. This review examines the emerging role of EVs in the pathogenesis of glaucoma, with a focus on their potential as diagnostic biomarkers and therapeutic agents. Through a thorough analysis of current literature, we summarize key advancements in EV research and identify areas where further investigation is needed to fully understand their function in glaucoma.

Extracellular RNA communication: A decade of NIH common fund support illuminates exRNA biology

The discovery that extracellular RNAs (exRNA) can act as endocrine signalling molecules established a novel paradigm in intercellular communication. ExRNAs can be transported, both locally and systemically in virtually all body fluids. In association with an array of carrier vehicles of varying complexity, exRNA can alter target cell phenotype. This highlights the important role secreted exRNAs have in regulating human health and disease. The NIH Common Fund exRNA Communication program was established in 2012 to accelerate and catalyze progress in the exRNA biology field. The program addressed both exRNA and exRNA carriers, and served to generate foundational knowledge for the field from basic exRNA biology to future potential clinical applications as biomarkers and therapeutics. To address scientific challenges, the exRNA Communication program developed novel tools and technologies to isolate exRNA carriers and analyze their cargo. Here, we discuss the outcomes of the NIH Common Fund exRNA Communication program, as well as the evolution of exRNA as a scientific field through the analysis of scientific publications and NIH funding. ExRNA and associated carriers have potential clinical use as biomarkers, diagnostics, and therapeutics. Recent translational applications include exRNA-related technologies repurposed as novel diagnostics in response to the COVID-19 pandemic, the clinical use of extracellular vesicle-based biomarker assays, and exRNA carriers as drug delivery platforms. This comprehensive landscape analysis illustrates how discoveries and innovations in exRNA biology are being translated both into the commercial market and the clinic. Analysis of program outcomes and NIH funding trends demonstrate the impact of this NIH Common Fund program.

Viscoelastic High-Molecular-Weight Hyaluronic Acid Hydrogels Support Rapid Glioblastoma Cell Invasion with Leader-Follower Dynamics

Hyaluronic acid (HA), the primary component of brain extracellular matrix, is increasingly used to model neuropathological processes, including glioblastoma (GBM) tumor invasion. While elastic hydrogels based on crosslinked low-molecular-weight (LMW) HA are widely exploited for this purpose and have proven valuable for discovery and screening, brain tissue is both viscoelastic and rich in high-MW (HMW) HA, and it remains unclear how these differences influence invasion. To address this question, hydrogels comprised of either HMW (1.5 MDa) or LMW (60 kDa) HA are introduced, characterized, and applied in GBM invasion studies. Unlike LMW HA hydrogels, HMW HA hydrogels relax stresses quickly, to a similar extent as brain tissue, and to a greater extent than many conventional HA-based scaffolds. GBM cells implanted within HMW HA hydrogels invade much more rapidly than in their LMW HA counterparts and exhibit distinct leader-follower dynamics. Leader cells adopt dendritic morphologies similar to invasive GBM cells observed in vivo. Transcriptomic, pharmacologic, and imaging studies suggest that leader cells exploit hyaluronidase, an enzyme strongly enriched in human GBMs, to prime a path for followers. This study offers new insight into how HA viscoelastic properties drive invasion and argues for the use of highly stress-relaxing materials to model GBM.

The roles of extracellular vesicles in gliomas: Challenge or opportunity?

Gliomas are increasingly becoming a major disease affecting human health, and current treatments are not as effective as expected. Deeper insights into glioma heterogeneity and the search for new diagnostic and therapeutic strategies appear to be urgent. Gliomas adapt to their surroundings and form a supportive tumor microenvironment (TME). Glioma cells will communicate with the surrounding cells through extracellular vesicles (EVs) carrying bioactive substances such as nucleic acids, proteins and lipids which is related to the modification to various metabolic pathways and regulation of biological behaviors, and this regulation can be bidirectional, widely existing between cells in the TME, constituting a complex network of interactions. This complex regulation can affect glioma therapy, leading to different types of resistance. Because of the feasibility of EVs isolation in various body fluids, they have a promising usage in the diagnosis and monitoring of gliomas. At the same time, the nature of EVs to cross the blood-brain barrier (BBB) confers potential for their use as drug delivery systems. In this review, we will focus on the roles and functions of EVs derived from different cellular origins in the glioma microenvironment and the intercellular regulatory networks, and explore possible clinical applications in glioma diagnosis and precision therapy.

Mechanisms of extracellular vesicle uptake and implications for the design of cancer therapeutics

The translation of pre-clinical anti-cancer therapies to regulatory approval has been promising, but slower than hoped. While innovative and effective treatments continue to achieve or seek approval, setbacks are often attributed to a lack of efficacy, failure to achieve clinical endpoints, and dose-limiting toxicities. Successful efforts have been characterized by the development of therapeutics designed to specifically deliver optimal and effective dosing to tumour cells while minimizing off-target toxicity. Much effort has been devoted to the rational design and application of synthetic nanoparticles to serve as targeted therapeutic delivery vehicles. Several challenges to the successful application of this modality as delivery vehicles include the induction of a protracted immune response that results in their rapid systemic clearance, manufacturing cost, lack of stability, and their biocompatibility. Extracellular vesicles (EVs) are a heterogeneous class of endogenous biologically produced lipid bilayer nanoparticles that mediate intercellular communication by carrying bioactive macromolecules capable of modifying cellular phenotypes to local and distant cells. By genetic, chemical, or metabolic methods, extracellular vesicles (EVs) can be engineered to display targeting moieties on their surface while transporting specific cargo to modulate pathological processes following uptake by target cell populations. This review will survey the types of EVs, their composition and cargoes, strategies employed to increase their targeting, uptake, and cargo release, and their potential as targeted anti-cancer therapeutic delivery vehicles.

Formin-like 1β phosphorylation at S1086 is necessary for secretory polarized traffic of exosomes at the immune synapse in Jurkat T lymphocytes

We analyzed here how formin-like 1 β (FMNL1β), an actin cytoskeleton-regulatory protein, regulates microtubule-organizing center (MTOC) and multivesicular bodies (MVB) polarization and exosome secretion at an immune synapse (IS) model in a phosphorylation-dependent manner. IS formation was associated with transient recruitment of FMNL1β to the IS, which was independent of protein kinase C δ (PKCδ). Simultaneous RNA interference of all FMNL1 isoforms prevented MTOC/MVB polarization and exosome secretion, which were restored by FMNL1βWT expression. However, expression of the non-phosphorylatable mutant FMNL1βS1086A did not restore neither MTOC/MVB polarization nor exosome secretion to control levels, supporting the crucial role of S1086 phosphorylation in MTOC/MVB polarization and exosome secretion. In contrast, the phosphomimetic mutant, FMNL1βS1086D, restored MTOC/MVB polarization and exosome secretion. Conversely, FMNL1βS1086D mutant did not recover the deficient MTOC/MVB polarization occurring in PKCδ-interfered clones, indicating that S1086 FMNL1β phosphorylation alone is not sufficient for MTOC/MVB polarization and exosome secretion. FMNL1 interference inhibited the depletion of F-actin at the central region of the immune synapse (cIS), which is necessary for MTOC/MVB polarization. FMNL1βWT and FMNL1βS1086D, but not FMNL1βS1086A expression, restored F-actin depletion at the cIS. Thus, actin cytoskeleton reorganization at the IS underlies the effects of all these FMNL1β variants on polarized secretory traffic. FMNL1 was found in the IS made by primary T lymphocytes, both in T cell receptor (TCR) and chimeric antigen receptor (CAR)-evoked synapses. Taken together, these results point out a crucial role of S1086 phosphorylation in FMNL1β activation, leading to cortical actin reorganization and subsequent control of MTOC/MVB polarization and exosome secretion.

Fluorogenic RNA-based biomaterials for imaging and tracking the cargo of extracellular vesicles

Extracellular vesicles (EVs), or exosomes, play important roles in physiological and pathological cellular communication and have gained substantial traction as biological drug carriers. EVs contain both short and long non-coding RNAs that regulate gene expression and epigenetic processes. To fully capitalize on the potential of EVs as drug carriers, it is important to study and understand the intricacies of EV function and EV RNA-based communication. Here we developed a genetically encodable RNA-based biomaterial, termed EXO-Probe, for tracking EV RNAs. The EXO-Probe comprises an EV-loading RNA sequence (EXO-Code), fused to a fluorogenic RNA Mango aptamer for RNA imaging. This fusion construct allowed the visualization and tracking of EV RNA and colocalization with markers of multivesicular bodies; imaging RNA within EVs, and non-destructive quantification of EVs. Overall, the new RNA-based biomaterial provides a useful and versatile means to interrogate the role of EVs in cellular communication via RNA trafficking to EVs and to study cellular sorting decisions. The system will also help lay the foundation to further improve the therapeutic efficacy of EVs as drug carriers.

Extracellular vesicle-functionalized bioactive scaffolds for bone regeneration

The clinical need for effective bone regeneration in compromised conditions continues to drive demand for innovative solutions. Among emerging strategies, extracellular vesicles (EVs) have shown promise as an acellular approach for bone regeneration. However, their efficacy is hindered by rapid sequestration and clearance when administered via bolus injection. To address this challenge, EV-functionalized scaffolds have recently been proposed as an alternative delivery strategy to enhance EV retention and subsequent healing efficacy. This review aims to consolidate recent advancements in the development of EV-functionalized scaffolds for augmenting bone regeneration. It explores various sources of EVs and different strategies for integrating them into biomaterials. Furthermore, the mechanisms underlying their therapeutic effects in bone regeneration are elucidated. Current limitations in clinical translation and perspectives on the design of more efficient EVs for improved therapeutic efficacy are also presented. Overall, this review can provide inspiration for the development of novel EV-assisted grafts with superior bone regeneration potential.

Direct and cell-mediated EV-ECM interplay

Extracellular vesicles (EV) are a heterogeneous group of lipid particles excreted by cells. They play an important role in regeneration, development, inflammation, and cancer progression, together with the extracellular matrix (ECM), which they constantly interact with. In this review, we discuss direct and indirect interactions of EVs and the ECM and their impact on different physiological processes. The ECM affects the secretion of EVs, and the properties of the ECM and EVs modulate EVs' diffusion and adhesion. On the other hand, EVs can affect the ECM both directly through enzymes and indirectly through the modulation of the ECM synthesis and remodeling by cells. This review emphasizes recently discovered types of EVs bound to the ECM and isolated by enzymatic digestion, including matrix-bound nanovesicles (MBV) and tissue-derived EV (TiEV). In addition to the experimental studies, computer models of the EV-ECM-cell interactions, from all-atom models to quantitative pharmacology models aiming to improve our understanding of the interaction mechanisms, are also considered. STATEMENT OF SIGNIFICANCE: Application of extracellular vesicles in tissue engineering is an actively developing area. Vesicles not only affect cells themselves but also interact with the matrix and change it. The matrix also influences both cells and vesicles. In this review, different possible types of interactions between vesicles, matrix, and cells are discussed. Furthermore, the united EV-ECM system and its regulation through the cellular activity are presented.

Defining the activity of pro-reparative extracellular vesicles in wound healing based on miRNA payloads and cell type-specific lineage mapping

Small extracellular vesicles (EVs) are released by cells and deliver biologically active payloads to coordinate the response of multiple cell types in cutaneous wound healing. Here we used a cutaneous injury model as a donor of pro-reparative EVs to treat recipient diabetic obese mice, a model of impaired wound healing. We established a functional screen for microRNAs (miRNAs) that increased the pro-reparative activity of EVs and identified a down-regulation of miR-425-5p in EVs in vivo and in vitro associated with the regulation of adiponectin. We tested a cell type-specific reporter of a tetraspanin CD9 fusion with GFP to lineage map the release of EVs from macrophages in the wound bed, based on the expression of miR-425-5p in macrophage-derived EVs and the abundance of macrophages in EV donor sites. Analysis of different promoters demonstrated that EV release under the control of a macrophage-specific promoter was most abundant and that these EVs were internalized by dermal fibroblasts. These findings suggested that pro-reparative EVs deliver miRNAs, such as miR-425-5p, that stimulate the expression of adiponectin that has insulin-sensitizing properties. We propose that EVs promote intercellular signaling between cell layers in the skin to resolve inflammation, induce proliferation of basal keratinocytes, and accelerate wound closure.

Asymmetric crowders and membrane morphology at the nexus of intracellular trafficking and oncology

A definitive understanding of the interplay between protein binding/migration and membrane curvature evolution is emerging but needs further study. The mechanisms defining such phenomena are critical to intracellular transport and trafficking of proteins. Among trafficking modalities, exosomes have drawn attention in cancer research as these nano-sized naturally occurring vehicles are implicated in intercellular communication in the tumor microenvironment, suppressing anti-tumor immunity and preparing the metastatic niche for progression. A significant question in the field is how the release and composition of tumor exosomes are regulated. In this perspective article, we explore how physical factors such as geometry and tissue mechanics regulate cell cortical tension to influence exosome production by co-opting the biophysics as well as the signaling dynamics of intracellular trafficking pathways and how these exosomes contribute to the suppression of anti-tumor immunity and promote metastasis. We describe a multiscale modeling approach whose impact goes beyond the fundamental investigation of specific cellular processes toward actual clinical translation. Exosomal mechanisms are critical to developing and approving liquid biopsy technologies, poised to transform future non-invasive, longitudinal profiling of evolving tumors and resistance to cancer therapies to bring us one step closer to the promise of personalized medicine.

The 8-oxoguanine DNA glycosylase-synaptotagmin 7 pathway increases extracellular vesicle release and promotes tumour metastasis during oxidative stress

Reactive oxygen species (ROS)-induced oxidative DNA damages have been considered the main cause of mutations in genes, which are highly related to carcinogenesis and tumour progression. Extracellular vesicles play an important role in cancer metastasis. However, the precise role of DNA oxidative damage in extracellular vesicles (EVs)-mediated cancer cell migration and invasion remains unclear. Here, we reveal that ROS-mediated DNA oxidative damage signalling promotes tumour metastasis through increasing EVs release. Mechanistically, 8-oxoguanine DNA glycosylase (OGG1) recognises and binds to its substrate 8-oxo-7,8-dihydroguanine (8-oxoG), recruiting NF-κB to the synaptotagmin 7 (SYT7) promoter and thereby triggering SYT7 transcription. The upregulation of SYT7 expression leads to increased release of E-cadherin-loaded EVs, which depletes intracellular E-cadherin, thereby inducing epithelial-mesenchymal transition (EMT). Notably, Th5487, the inhibitor of DNA binding activity of OGG1, blocks the recognition and transmission of oxidative signals, alleviates SYT7 expression and suppresses EVs release, thereby preventing tumour progression in vitro and in vivo. Collectively, our study illuminates the significance of 8-oxoG/OGG1/SYT7 axis-driven EVs release in oxidative stress-induced tumour metastasis. These findings provide a deeper understanding of the molecular basis of cancer progression and offer potential avenues for therapeutic intervention.

The trajectory of vesicular proteomic signatures from HBV-HCC by chitosan-magnetic bead-based separation and DIA-proteomic analysis

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer often associated with chronic hepatitis B virus infection (CHB) and liver cirrhosis (LC), underscoring the critical need for biomarker discovery to improve patient outcomes. Emerging as a promising avenue for biomarker development, proteomic technology leveraging liquid biopsy from small extracellular vesicles (sEV) offers new insights. Here, we evaluated various methods for sEV isolation and identified polysaccharide chitosan (CS) as an optimal approach. Subsequently, we employed optimized CS-based magnetic beads (Mag-CS) for sEV separation from serum samples of healthy controls, CHB, LC, and HBV-HCC patients. Leveraging data-independent acquisition mass spectrometry coupled with machine learning, we uncovered potential vesicular protein biomarker signatures (KNG1, F11, KLKB1, CAPNS1, CDH1, CPN2, NME2) capable of distinguishing HBV-HCC from CHB, LC, and non-HCC conditions. Collectively, our findings highlight the utility of Mag-CS-based sEV isolation for identifying early detection biomarkers in HBV-HCC.

New Insights into the Exosome-Induced Migration of Uveal Melanoma Cells and the Pre-Metastatic Niche Formation in the Liver

UM is an aggressive intraocular tumor characterized by high plasticity and a propensity to metastasize in the liver. However, the underlying mechanisms governing liver tropism remain poorly understood. Given the emerging significance of exosomes, we sought to investigate the contribution of UM-derived exosomes to specific steps of the metastatic process. Firstly, we isolated exosomes from UM cells sharing a common genetic background and different metastatic properties. A comparison of protein cargo reveals an overrepresentation of proteins related to cytoskeleton remodeling and actin filament-based movement in exosomes derived from the parental cells that may favor the detachment of cells from the primary site. Secondly, we assessed the role of macrophages in reprogramming the HHSCs by exosomes. The activation of HHSCs triggered a pro-inflammatory and pro-fibrotic environment through cytokine production, upregulation of extracellular matrix molecules, and the activation of signaling pathways. Finally, we found that activated HHSCs promote increased adhesion and migration of UM cells. Our findings shed light on the pivotal role of exosomes in pre-metastatic niche construction in the liver.

Extracellular Vesicles in Cardiovascular Pathophysiology: Communications, Biomarkers, and Therapeutic Potential

Extracellular vesicles (EVs) are diverse, membrane-bound vesicles released from cells into the extracellular environment. They originate from either endosomes or the cell membrane and typically include exosomes and microvesicles. These EVs serve as crucial mediators of intercellular communication, carrying a variety of contents such as nucleic acids, proteins, and lipids, which regulate the physiological and pathological processes of target cells. Moreover, the molecular cargo of EVs can reflect critical information about the originating cells, making them potential biomarkers for the diagnosis and prognosis of diseases. Over the past decade, the role of EVs as key communicators between cell types in cardiovascular physiology and pathology has gained increasing recognition. EVs from different cellular sources, or from the same source under different cellular conditions, can have distinct impacts on the management, diagnosis, and prognosis of cardiovascular diseases. Furthermore, it is essential to consider the influence of cardiovascular-derived EVs on the metabolism of peripheral organs. This review aims to summarize recent advancements in the field of cardiovascular research with respect to the roles and implications of EVs. Our goal is to provide new insights and directions for the early prevention and treatment of cardiovascular diseases, with an emphasis on the therapeutic potential and diagnostic value of EVs.

A case for the study of native extracellular vesicles

Three main areas of research revolve around extracellular vesicles (EVs): their use as early detection diagnostics for cancer prevention, engineering of EVs or other enveloped viral-like particles for therapeutic purposes and to understand how EVs impact biological processes. When investigating the biology of EVs, it is important to consider strategies able to track and alter EVs directly in vivo, as they are released by donor cells. This can be achieved by suitable engineering of EV donor cells, either before implantation or directly in vivo. Here, we make a case for the study of native EVs, that is, EVs released by cells living within a tissue. Novel genetic approaches to detect intercellular communications mediated by native EVs and profile recipient cells are discussed. The use of Rab35 dominant negative mutant is proposed for functional in vivo studies on the roles of native EVs. Ultimately, investigations on native EVs will tremendously advance our understanding of EV biology and open novel opportunities for therapy and prevention.

Fluorescent, phosphorescent, magnetic resonance contrast and radioactive tracer labelling of extracellular vesicles

This review focusses on the significance of fluorescent, phosphorescent labelling and tracking of extracellular vesicles (EVs) for unravelling their biology, pathophysiology, and potential diagnostic and therapeutic uses. Various labeling strategies, such as lipid membrane, surface protein, luminal, nucleic acid, radionuclide, quantum dot labels, and metal complex-based stains, are evaluated for visualizing and characterizing EVs. Direct labelling with fluorescent lipophilic dyes is simple but generally lacks specificity, while surface protein labelling offers selectivity but may affect EV-cell interactions. Luminal and nucleic acid labelling strategies have their own advantages and challenges. Each labelling approach has strengths and weaknesses, which require a suitable probe and technique based on research goals, but new tetranuclear polypyridylruthenium(II) complexes as phosphorescent probes have strong phosphorescence, selective staining, and stability. Future research should prioritize the design of novel fluorescent probes and labelling platforms that can significantly enhance the efficiency, accuracy, and specificity of EV labeling, while preserving their composition and functionality. It is crucial to reduce false positive signals and explore the potential of multimodal imaging techniques to gain comprehensive insights into EVs.

Extracellular Vesicle-Mediated Modulation of Stem-like Phenotype in Breast Cancer Cells under Fluid Shear Stress

Circulating tumor cells (CTCs) are some of the key culprits that cause cancer metastasis and metastasis-related deaths. These cells exist in a dynamic microenvironment where they experience fluid shear stress (FSS), and the CTCs that survive FSS are considered to be highly metastatic and stem cell-like. Biophysical stresses such as FSS are also known to cause the production of extracellular vesicles (EVs) that can facilitate cell-cell communication by carrying biomolecular cargos such as microRNAs. Here, we hypothesized that physiological FSS will impact the yield of EV production, and that these EVs will have biomolecules that transform the recipient cells. The EVs were isolated using direct flow filtration with and without FSS from the MDA-MB-231 cancer cell line, and the expression of key stemness-related genes and microRNAs was characterized. There was a significantly increased yield of EVs under FSS. These EVs also contained significantly increased levels of miR-21, which was previously implicated to promote metastatic progression and chemotherapeutic resistance. When these EVs from FSS were introduced to MCF-7 cancer cells, the recipient cells had a significant increase in their stem-like gene expression and CD44+/CD24- cancer stem cell-like subpopulation. There was also a correlated increased proliferation along with an increased ATP production. Together, these findings indicate that the presence of physiological FSS can directly influence the EVs' production and their contents, and that the EV-mediated transfer of miR-21 can have an important role in FSS-existing contexts, such as in cancer metastasis.

The emerging role of the exosomal proteins in neuroblastoma

Exosomes are a subclass of extracellular vesicles shown to promote the cancer growth and support metastatic progression. The proteomic analysis of neuroblastoma-derived exosomes has revealed proteins involved in cell migration, proliferation, metastasis, and in the modulation of tumor microenvironment - thus contributing to the tumor development and an aggressive metastatic phenotype. This review gives an overview of the current understanding of the exosomal proteins in neuroblastoma and of their potential as diagnostic/prognostic biomarker of disease and therapeutics.

A novel cell-free therapy using exosomes in the inner ear regeneration

Cellular and molecular alterations associated with hearing loss are now better understood with advances in molecular biology. These changes indicate the participation of distinct damage and stress pathways that are unlikely to be fully addressed by conventional pharmaceutical treatment. Sensorineural hearing loss is a common and debilitating condition for which comprehensive pharmacologic intervention is not available. The complex and diverse molecular pathology that underlies hearing loss currently limits our ability to intervene with small molecules. The present review focuses on the potential for the use of extracellular vesicles in otology. It examines a variety of inner ear diseases and hearing loss that may be treatable using exosomes (EXOs). The role of EXOs as carriers for the treatment of diseases related to the inner ear as well as EXOs as biomarkers for the recognition of diseases related to the ear is discussed.

Impacts of tissue context on extracellular vesicles-mediated cancer-host cell communications

Tumor tissue is densely packed with cancer cells, non-cancerous cells, and ECM, forming functional structures. Cancer cells transfer extracellular vesicles (EVs) to modify surrounding normal cells into cancer-promoting cells, establishing a tumor-favorable environment together with other signaling molecules and structural components. Such tissue environments largely affect cancer cell properties, and so as EV-mediated cellular communications within tumor tissue. However, current research on EVs focuses on functional analysis of vesicles isolated from the liquid phase, including cell culture supernatants and blood draws, 2D-cultured cell assays, or systemic analyses on animal models for biodistribution. Therefore, we have a limited understanding of local EV transfer within tumor tissues. In this review, we discuss the need to study EVs in a physiological tissue context by summarizing the current findings on the impacts of tumor tissue environment on cancer EV properties and transfer and the techniques required for the analysis. Tumor tissue environment is likely to alter EV properties, pose physical barriers, interactions, and interstitial flows for the dynamics, and introduce varieties in the cell types taken up. Utilizing physiological experimental settings and spatial analyses, we need to tackle the remaining questions on physiological EV-mediated cancer-host cell interactions. Understanding cancer EV-mediated cellular communications in physiological tumor tissues will lead to developing interaction-targeting therapies and provide insight into EV-mediated non-cancerous cells and interspecies interactions.

Extracellular vesicles from non-neuroendocrine SCLC cells promote adhesion and survival of neuroendocrine SCLC cells

Small cell lung cancer (SCLC) tumors are made up of distinct cell subpopulations, including neuroendocrine (NE) and non-neuroendocrine (non-NE) cells. While secreted factors from non-NE SCLC cells have been shown to support the growth of the NE cells, the underlying molecular factors are not well understood. Here, we show that exosome-type small extracellular vesicles (SEVs) secreted from non-NE SCLC cells promote adhesion and survival of NE SCLC cells. Proteomic analysis of purified SEVs revealed that extracellular matrix (ECM) proteins and integrins are highly enriched in SEVs of non-NE cells whereas nucleic acid-binding proteins are enriched in SEVs purified from NE cells. Addition of select purified ECM proteins identified in purified extracellular vesicles (EVs), specifically fibronectin, laminin 411, and laminin 511, were able to substitute for the role of non-NE-derived SEVs in promoting adhesion and survival of NE SCLC cells. Those same proteins were differentially expressed by human SCLC subtypes. These data suggest that ECM-carrying SEVs secreted by non-NE cells play a key role in supporting the growth and survival of NE SCLC cells.

The Role of αvβ3 Integrin in Cancer Therapy Resistance

A relevant challenge for the treatment of patients with neoplasia is the development of resistance to chemo-, immune-, and radiotherapies. Although the causes of therapy resistance are poorly understood, evidence suggests it relies on compensatory mechanisms that cells develop to replace specific intracellular signaling that should be inactive after pharmacological inhibition. One such mechanism involves integrins, membrane receptors that connect cells to the extracellular matrix and have a crucial role in cell migration. The blockage of one specific type of integrin is frequently compensated by the overexpression of another integrin dimer, generally supporting cell adhesion and migration. In particular, integrin αvβ3 is a key receptor involved in tumor resistance to treatments with tyrosine kinase inhibitors, immune checkpoint inhibitors, and radiotherapy; however, the specific inhibition of the αvβ3 integrin is not enough to avoid tumor relapse. Here, we review the role of integrin αvβ3 in tumor resistance to therapy and the mechanisms that have been proposed thus far. Despite our focus on the αvβ3 integrin, it is important to note that other integrins have also been implicated in drug resistance and that the collaborative action between these receptors should not be neglected.

Extracellular vesicles promote migration despite BRAF inhibitor treatment in malignant melanoma cells

Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance mechanisms. Malignant melanoma (MM) is one of the deadliest forms of skin cancers, because of its high metastatic potential and often acquired resistance to oncotherapies. The prevalence of BRAF mutations in MM underscores the importance of BRAF-targeted therapies, such as vemurafenib and dabrafenib, alone or in combination with the MEK inhibitor, trametinib. This study aimed to elucidate the involvement of EVs in MM progression and ascertain whether EV-mediated metastasis promotion persists during single agent BRAF (vemurafenib, dabrafenib), or MEK (trametinib) and combined BRAF/MEK (dabrafenib/trametinib) inhibition.Using five pairs of syngeneic melanoma cell lines, we assessed the impact of EVs - isolated from their respective supernatants - on melanoma cell proliferation and migration. Cell viability and spheroid growth assays were employed to evaluate proliferation, while migration was analyzed through mean squared displacement (MSD) and total traveled distance (TTD) measurements derived from video microscopy and single-cell tracking.Our results indicate that while EV treatments had remarkable promoting effect on cell migration, they exerted only a modest effect on cell proliferation and spheroid growth. Notably, EVs demonstrated the ability to mitigate the inhibitory effects of BRAF inhibitors, albeit they were ineffective against a MEK inhibitor and the combination of BRAF/MEK inhibitors. In summary, our findings contribute to the understanding of the intricate role played by EVs in tumor progression, metastasis, and drug resistance in MM.

Integrated proteomic, phosphoproteomic, and N-glycoproteomic analyses of small extracellular vesicles from C2C12 myoblasts identify specific PTM patterns in ligand-receptor interactions

Small extracellular vesicles (sEVs) are important mediators of intercellular communication by transferring of functional components (proteins, RNAs, and lipids) to recipient cells. Some PTMs, including phosphorylation and N-glycosylation, have been reported to play important role in EV biology, such as biogenesis, protein sorting and uptake of sEVs. MS-based proteomic technology has been applied to identify proteins and PTM modifications in sEVs. Previous proteomic studies of sEVs from C2C12 myoblasts, an important skeletal muscle cell line, focused on identification of proteins, but no PTM information on sEVs proteins is available.In this study, we systematically analyzed the proteome, phosphoproteome, and N-glycoproteome of sEVs from C2C12 myoblasts with LC-MS/MS. In-depth analyses of the three proteomic datasets revealed that the three proteomes identified different catalogues of proteins, and PTMomic analysis could expand the identification of cargos in sEVs. At the proteomic level, a high percentage of membrane proteins, especially tetraspanins, was identified. The sEVs-derived phosphoproteome had a remarkably high level of tyrosine-phosphorylated sites. The tyrosine-phosphorylated proteins might be involved with EPH-Ephrin signaling pathway. At the level of N-glycoproteomics, several glycoforms, such as complex N-linked glycans and sialic acids on glycans, were enriched in sEVs. Retrieving of the ligand-receptor interaction in sEVs revealed that extracellular matrix (ECM) and cell adhesion molecule (CAM) represented the most abundant ligand-receptor pairs in sEVs. Mapping the PTM information on the ligands and receptors revealed that N-glycosylation mainly occurred on ECM and CAM proteins, while phosphorylation occurred on different categories of receptors and ligands. A comprehensive PTM map of ECM-receptor interaction and their components is also provided.In summary, we conducted a comprehensive proteomic and PTMomic analysis of sEVs of C2C12 myoblasts. Integrated proteomic, phosphoproteomic, and N-glycoproteomic analysis of sEVs might provide some insights about their specific uptake mechanism.

LS, Saftics A, Shodubi O, Raghunandan S, Xu J, Tsai SJ, Dong Y, Li R, Jovanovic-Talisman T, Gould SJ. Endocytosis blocks the vesicular secretion of exosome marker proteins

Exosomes are secreted vesicles of ~30 to 150 nm diameter that play important roles in human health and disease. To better understand how cells release these vesicles, we examined the biogenesis of the most highly enriched human exosome marker proteins, the exosomal tetraspanins CD81, CD9, and CD63. We show here that endocytosis inhibits their vesicular secretion and, in the case of CD9 and CD81, triggers their destruction. Furthermore, we show that syntenin, a previously described exosome biogenesis factor, drives the vesicular secretion of CD63 by blocking CD63 endocytosis and that other endocytosis inhibitors also induce the plasma membrane accumulation and vesicular secretion of CD63. Finally, we show that CD63 is an expression-dependent inhibitor of endocytosis that triggers the vesicular secretion of lysosomal proteins and the clathrin adaptor AP-2 mu2. These results suggest that the vesicular secretion of exosome marker proteins in exosome-sized vesicles occurs primarily by an endocytosis-independent pathway.

Multiparametric Single-Vesicle Flow Cytometry Resolves Extracellular Vesicle Heterogeneity and Reveals Selective Regulation of Biogenesis and Cargo Distribution

Mammalian cells release a heterogeneous array of extracellular vesicles (EVs) that contribute to intercellular communication by means of the cargo that they carry. To resolve EV heterogeneity and determine if cargo is partitioned into select EV populations, we developed a method named "EV Fingerprinting" that discerns distinct vesicle populations using dimensional reduction of multiparametric data collected by quantitative single-EV flow cytometry. EV populations were found to be discernible by a combination of membrane order and EV size, both of which were obtained through multiparametric analysis of fluorescent features from the lipophilic dye Di-8-ANEPPS incorporated into the lipid bilayer. Molecular perturbation of EV secretion and biogenesis through respective ablation of the small GTPase Rab27a and overexpression of the EV-associated tetraspanin CD63 revealed distinct and selective alterations in EV populations, as well as cargo distribution. While Rab27a disproportionately affects all small EV populations with high membrane order, the overexpression of CD63 selectively increased the production of one small EV population of intermediate membrane order. Multiplexing experiments subsequently revealed that EV cargos have a distinct, nonrandom distribution with CD63 and CD81 selectively partitioning into smaller vs larger EVs, respectively. These studies not only present a method to probe EV biogenesis but also reveal how the selective partitioning of cargo contributes to EV heterogeneity.

Breast cancer derived exosomes: Theragnostic perspectives and implications

Breast cancer (BC) is the most prevalent malignancy affecting women worldwide. Although conventional treatments such as chemotherapy, surgery, hormone therapy, radiation therapy, and biological therapy are commonly used, they often entail significant side effects. Therefore, there is a critical need to investigate more cost-effective and efficient treatment modalities in BC. Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, play a crucial role in modulating recipient cell behaviour and driving cancer progression. Among the EVs, exosomes provide valuable insights into cellular dynamics under both healthy and diseased conditions. In cancer, exosomes play a critical role in driving tumor progression and facilitating the development of drug resistance. BC-derived exosomes (BCex) dynamically influence BC progression by regulating cell proliferation, immunosuppression, angiogenesis, metastasis, and the development of treatment resistance. Additionally, BCex serve as promising diagnostic markers in BC which are detectable in bodily fluids such as urine and saliva. Targeted manipulation of BCex holds significant therapeutic potential. This review explores the therapeutic and diagnostic implications of exosomes in BC, underscoring their relevance to the disease. Furthermore, it discusses future directions for exosome-based research in BC, emphasizing the necessity for further exploration in this area.