Recent Progress in Extracellular Vesicle-Based Carriers for Targeted Drug Delivery in Cancer Therapy

Extracellular vesicles (EVs) are small, membrane-based vesicles released by cells that play a critical role in various physiological and pathological processes. They act as vehicles for transporting a variety of endogenous cargo molecules, enabling intercellular communication. Due to their natural properties, EVs have emerged as a promising "cell-free therapy" strategy for treating various diseases, including cancer. They serve as excellent carriers for different therapeutics, including nucleic acids, proteins, small molecules, and other nanomaterials. Modifying or engineering EVs can improve the efficacy, targeting, specificity, and biocompatibility of EV-based therapeutics for cancer therapy. In this review, we comprehensively outline the biogenesis, isolation, and methodologies of EVs, as well as their biological functions. We then focus on specific applications of EVs as drug carriers in cancer therapy by citing prominent recent studies. Additionally, we discuss the opportunities and challenges for using EVs as pharmaceutical drug delivery vehicles. Ultimately, we aim to provide theoretical and technical support for the development of EV-based carriers for cancer treatment.

Activation of Sestrin2 accelerates deep second-degree burn wound healing through PI3K/AKT pathway

Deep second-degree burns heal slowly, and promoting the healing process is a focus of clinical research. Sestrin2 is a stress-inducible protein with antioxidant and metabolic regulatory effects. However, its role during acute dermal and epidermal re-epithelialization in deep second-degree burns is unknown. In this study, we aimed to explore the role and molecular mechanism of sestrin2 in deep second-degree burns as a potential treatment target for burn wounds. To explore the effects of sestrin2 on burn wound healing, we established a deep second-degree burn mouse model. Then we detected the expression of sestrin2 by western blot and immunohistochemistry after obtaining the wound margin of full-thickness burned skin. The effects of sestrin2 on burn wound healing were explored in vivo and in vitro through interfering sestrin2 expression using siRNAs or the small molecule agonist of sestrin2, eupatilin. We also investigated the molecular mechanism of sestrin2 in promoting burn wound healing by western blot and CCK-8 assay. Our in vivo and in vitro deep second-degree burn wound healing model demonstrated that sestrin2 was promptly induced at murine skin wound edges. The small molecule agonist of sestrin2 accelerated the proliferation and migration of keratinocytes, as well as burn wound healing. Conversely, the healing of burn wounds was delayed in sestrin2-deficient mice and was accompanied by the secretion of inflammatory cytokines as well as the suppression of keratinocyte proliferation and migration. Mechanistically, sestrin2 promoted the phosphorylation of the PI3K/AKT pathway, and inhibition of PI3K/AKT pathway abrogated the promoting role of sestrin2 in keratinocyte proliferation and migration. Therefore, sestrin2 plays a critical role in activation of the PI3K/AKT pathway to promote keratinocyte proliferation and migration, as well as re-epithelialization in the process of deep second-degree burn wound repair.

Mitochondria-derived vesicles and their potential roles in kidney stone disease

Recent evidence has shown significant roles of mitochondria-derived vesicles (MDVs) in mitochondrial quality control (MQC) system. Under mild stress condition, MDVs are formed to carry the malfunctioned mitochondrial components, such as mitochondrial DNA (mtDNA), peptides, proteins and lipids, to be eliminated to restore normal mitochondrial structure and functions. Under severe oxidative stress condition, mitochondrial dynamics (fission/fusion) and mitophagy are predominantly activated to rescue mitochondrial structure and functions. Additionally, MDVs generation can be also triggered as the major MQC machinery to cope with unhealthy mitochondria when mitophagy is unsuccessful for eliminating the damaged mitochondria or mitochondrial fission/fusion fail to recover the mitochondrial structure and functions. This review summarizes the current knowledge on MDVs and discuss their roles in physiologic and pathophysiologic conditions. In addition, the potential clinical relevance of MDVs in therapeutics and diagnostics of kidney stone disease (KSD) are emphasized.

Bidirectional Communication Between the Brain and Other Organs: The Role of Extracellular Vesicles

A number of substances released by the brain under physiological and pathological conditions exert effects on other organs. In turn, substances produced primarily by organs such as bone marrow, adipose tissue, or the heart may have an impact on the metabolism and function and metabolism of the healthy and diseased brain. Despite a mounting amount of evidence supports such bidirectional communication between the brain and other organs, research on the function of molecular mediators carried by extracellular vesicles (EVs) is in the early stages. In addition to being able to target or reach practically any organ, EVs have the ability to cross the blood-brain barrier to transport a range of substances (lipids, peptides, proteins, and nucleic acids) to recipient cells, exerting biological effects. Here, we review the function of EVs in bidirectional communication between the brain and other organs. In a small number of cases, the role has been explicitly proven; yet, in most cases, it relies on indirect evidence from EVs in cell culture or animal models. There is a dearth of research currently available on the function of EVs-carrying mediators in the bidirectional communication between the brain and bone marrow, adipose tissue, liver, heart, lungs, and gut. Therefore, more studies are needed to determine how EVs facilitate communication between the brain and other organs.

The Regulatory Mechanism of Cold Plasma in Relation to Cell Activity and Its Application in Biomedical and Animal Husbandry Practices

As an innovative technology in biological applications, cold plasma is widely used in oral treatment, tissue regeneration, wound healing, and cancer therapy, etc., because of the adjustable composition and temperature which allow the plasma to react with bio-objects safely. Reactive oxygen species (ROS) produced by cold plasma regulate cell activity in an intensity- and time-dependent manner. A low level of ROS produced by cold plasma treatment within the appropriate intensities and times promotes proliferation of skin-related cells and increases angiogenesis, which aid in the acceleration of the wound healing process, while a high level of ROS produced by cold plasma treatment performed at a high intensity or over a long period of time inhibits the proliferation of endothelial cells, keratinocytes, fibroblasts, and cancer cells. Moreover, cold plasma can regulate stem cell proliferation by changing niche interface and producing nitric oxide directly. However, the molecular mechanism of cold plasma regulating cell activity and its potential application in the field of animal husbandry remain unclear in the literature. Therefore, this paper reviews the effects and possible regulatory mechanisms of cold plasma on the activities of endothelial cells, keratinocytes, fibroblasts, stem cells, and cancer cells to provide a theoretical basis for the application of cold plasma to skin-wound healing and cancer therapy. In addition, cold plasma exposure at a high intensity or an extended time shows excellent performances in killing various microorganisms existing in the environment or on the surface of animal food, and preparing inactivated vaccines, while cold plasma treatment within the appropriate conditions improves chicken growth and reproductive capacity. This paper introduces the potential applications of cold plasma treatment in relation to animal-breeding environments, animal health, their growth and reproduction, and animal food processing and preservation, which are all beneficial to the practice of animal husbandry and guarantee good animal food safety results.

Engineered Extracellular Vesicles as a Targeted Delivery Platform for Precision Therapy

Extracellular vesicles (EVs)-based cell-free strategy has shown therapeutic potential in tissue regeneration. Due to their important roles in intercellular communications and their natural ability to shield cargos from degradation, EVs are also emerged as novel delivery vehicles for various bioactive molecules and drugs. Accumulating studies have revealed that EVs can be modified to enhance their efficacy and specificity for the treatment of many diseases. Engineered EVs are poised as the next generation of targeted delivery platform in the field of precision therapy. In this review, the unique properties of EVs are overviewed in terms of their biogenesis, contents, surface features and biological functions, and the recent advances in the strategies of engineered EVs construction are summarized. Additionally, we also discuss the potential applications of engineered EVs in targeted therapy of cancer and damaged tissues, and evaluate the opportunities and challenges for translating them into clinical practice.

Emerging role of mesenchymal stem cell-derived extracellular vesicles in oral and craniomaxillofacial tissue regenerative medicine

Mesenchymal stem cells (MSCs) are multipotent stem cells with differentiation potential and paracrine properties, drawing significant attention in the field of regenerative medicine. Extracellular vesicles (EVs), mainly including exosomes, microvesicles and apoptotic bodies (ABs), are predominantly endosomal in origin and contain bioactive molecules, such as miRNAs, mRNAs, and proteins, which are transferred from their original cells to target cells. Recently it has emerged that MSC-derived EVs (MSC-EVs) combine the advantages of MSCs and EVs, which may be used as a promising MSC-based therapy in tissue repair and regeneration. Oral and craniomaxillofacial diseases are clinically complications containing the soft and hard tissues in craniofacial and dental arches. These diseases are often induced by various factors, such as chemical, microbiological, physical factors, and systemic disorders. For decades, tissue repair and regeneration in oral and craniomaxillofacial regions provide substantial improvements in the prevention and treatment of some severe diseases. In this review we discuss MSC-EVs and their therapeutic potential in oral and craniomaxillofacial tissue regenerative medicine.

The Antisenescence Effect of Exosomes from Human Adipose-Derived Stem Cells on Skin Fibroblasts

Human adipose-derived stem cells (ADSCs) have become a promising therapeutic approach against skin aging. Recent studies confirm that exosomes partially mediate the therapeutic effect of stem cells. This study successfully isolated exosomes from the ADSC culture medium and discovered that ADSC-derived exosomes (ADSC-Exos) could alleviate human dermal fibroblast (HDF) senescence and stimulate HDF migration. Moreover, ADSC-Exos increased the type I collagen expression level and reduced the reactive oxygen species (ROS) and senescence-associated β-galactosidase (SA-β-Gal) activity in HDFs. In addition, we demonstrated that ADSC-Exos significantly inhibited senescence-related protein expression levels of p53, p21, and p16. In conclusion, our results have revealed the antisenescence effects of ADSC-Exos on HDFs and ADSC-Exos may be a novel cell-free therapeutic tool for antiaging.

The Use of Menthol in Skin Wound Healing-Anti-Inflammatory Potential, Antioxidant Defense System Stimulation and Increased Epithelialization

Wound healing involves inflammatory, proliferative, and remodeling phases, in which various cells and chemical intermediates are involved. This study aimed to investigate the skin wound healing potential of menthol, as well as the mechanisms involved in its effect, after 3, 7, or 14 days of treatment, according to the phases of wound healing. Skin wound was performed in the back of Wistar rats, which were topically treated with vehicle cream; collagenase-based cream (1.2 U/g); or menthol-based cream at 0.25%, 0.5%, or 1.0% over 3, 7, or 14 days. Menthol cream at 0.5% accelerated the healing right from the inflammatory phase (3 days) by decreasing mRNA expression of inflammatory cytokines TNF-α and Il-6. At the proliferative phase (7 days), menthol 0.5% increased the activity of antioxidant enzymes SOD, GR, and GPx, as well as the level of GSH, in addition to decreasing the levels of inflammatory cytokines TNF-α, IL-6, and IL-1β and augmenting mRNA expression for Ki-67, a marker of cellular proliferation. At the remodeling phase (14 days), levels of inflammatory cytokines were decreased, and the level of Il-10 and its mRNA expression were increased in the menthol 0.5% group. Menthol presented skin wound healing activity by modulating the antioxidant system of the cells and the inflammatory response, in addition to stimulating epithelialization.

Diagnostic and Therapeutic Role of Extracellular Vesicles in Articular Cartilage Lesions and Degenerative Joint Diseases

Two leading contributors to the global disability are cartilage lesions and degenerative joint diseases, which are characterized by the progressive cartilage destruction. Current clinical treatments often fail due to variable outcomes and an unsatisfactory long-term repair. Cell-based therapies were once considered as an effective solution because of their anti-inflammatory and immunosuppression characteristics as well as their differentiation capacity to regenerate the damaged tissue. However, stem cell-based therapies have inherent limitations, such as a high tumorigenicity risk, a low retention, and an engraftment rate, as well as strict regulatory requirements, which result in an underwhelming therapeutic effect. Therefore, the non-stem cell-based therapy has gained its popularity in recent years. Extracellular vesicles (EVs), in particular, like the paracrine factors secreted by stem cells, have been proven to play a role in mediating the biological functions of target cells, and can achieve the therapeutic effect similar to stem cells in cartilage tissue engineering. Therefore, a comprehensive review of the therapeutic role of EVs in cartilage lesions and degenerative joint diseases can be discussed both in terms of time and favorability. In this review, we summarized the physiological environment of a joint and its pathological alteration after trauma and consequent changes in EVs, which are lacking in the current literature studies. In addition, we covered the potential working mechanism of EVs in the repair of the cartilage and the joint and also discussed the potential therapeutic applications of EVs in future clinical use.

Granulation tissue myofibroblasts during normal and pathological skin healing: The interaction between their secretome and the microenvironment

The first role that was proposed for the myofibroblasts located in skin granulation tissue was to contract the edges of the wound in order to reduce the surface to be repaired. This role, linked to the presence of alpha smooth muscle actin, was very quickly confirmed and is part of the definition of granulation tissue myofibroblasts. However, myofibroblasts are cells that also play a much more central role in wound healing. Indeed, it has been shown that these cells produce large quantities of matrix components, and that they stimulate angiogenesis and can recruit immune cells. These actions take place via the secretion of molecules into their environment or indirectly via the production of microvesicles containing pro-fibrotic and pro-angiogenic molecules. Pathologically, granulation tissue can develop into a hypertrophic scar that histologically looks like granulation tissue, but which can remain for months or even years. It has been hypothesized that the myofibroblasts in these tissues remained present instead of disappearing by apoptosis, causing the maintenance of granulation tissue rather than allowing its change into a mature scar. Understanding the roles of both pathological and healthy myofibroblasts in wound tissue is crucial in order to better intervene in the healing mechanism.

Photobiomodulation induces microvesicle release in human keratinocytes: PI3 kinase-dependent pathway role

Microvesicles (MVs, 100-1000 nm diameter) are released into the extracellular environment by mammalian cells. MVs interact with near or remote cells through different mechanisms; in particular, MVs from human keratinocytes accelerate wound healing. Photobiomodulation by laser improves wound healing, but no information is available about its effects on MV release from human keratinocyte. Human-immortalized keratinocytes (human adult low-calcium high-temperature, HaCaT) were starved for 24 h and then irradiated using a 980-nm energy density of 0, 16.2, 32.5, and 48.7 J/cm². After 24 h, MVs released in the conditioned medium were isolated, stained, and quantified using flow cytometry. MVs were distinguished from exosomes on the basis of their volume (forward scatter signals). In some experiments, phosphatidylinositol 3-kinase (PI-3K) activity, involved in MV release and stimulated by laser light, was inhibited by pre-treating cells with Wortmannin (WRT, 10 μg/mL). MVs were observed in HaCaT-conditioned medium both in basal- and laser-stimulated conditions. Photobiomodulation therapy, also known as PBMT, was able to increase MV release from human keratinocytes reaching a maximum effect at 32.5 J/cm² with a stimulation of (148.6 ±15.1)% of basal (p<0.001). PI-3K activity inhibition strongly reduced both basal- and laser-induced MV release; but PBMT by laser still increased MV release, compared to basal values in the presence of WRT. In vitro near infrared photobiomodulation increased the releasing of MVs from human keratinocytes, while Wortmannin, a PI-3K inhibitor, negatively affects both basal- and laser-induced releasing. Laser-induced MV release could be a new effect of biostimulation on the wound healing process.

Shedding of proangiogenic microvesicles from hypertrophic scar myofibroblasts

Hypertrophic scars are a common complication of burn injuries and represent a major challenge in terms of prevention and treatment. These scars are characterized by a supraphysiological vascular density and by the presence of pathological myofibroblasts (Hmyos) displaying a low apoptosis propensity. However, the nature of the association between these two hallmarks of hypertrophic scarring remains largely unexplored. Here, we show that Hmyos produce signalling entities known as microvesicles that significantly increase the three cellular processes underlying blood vessel formation: endothelial cell proliferation, migration and assembly into capillary-like structures. The release of microvesicles from Hmyos was dose-dependently induced by the serum protein α-2-macroglobulin. Using flow cytometry, we revealed the presence of the α-2-macroglobulin receptor-low-density lipoprotein receptor-related protein 1-on the surface of Hmyos. The inhibition of the binding of α-2-macroglobulin to its receptor abolished the shedding of proangiogenic microvesicles from Hmyos. These findings suggest that the production of microvesicles by Hmyos contributes to the excessive vascularization of hypertrophic scars. α-2-Macroglobulin modulates the release of these microvesicles through interaction with low-density lipoprotein receptor-related protein 1.

Effects of Plasma-Activated Water on Skin Wound Healing in Mice

Cold atmospheric plasma (CAP) has been widely used in biomedicine during the last two decades. While direct plasma treatment has been reported to promote wound healing, its application can be uneven and inconvenient. In this study, we first activated water with a portable dielectric barrier discharge plasma device and evaluated the inactivation effect of plasma-activated water (PAW) on several kinds of bacteria that commonly infect wounds. The results show that PAW can effectively inactivate these bacteria. Then, we activated tap water and examined the efficacy of PAW on wound healing in a mouse model of full-thickness skin wounds. We found that wound healing in mice treated with PAW was significantly faster compared with the control group. Histological analysis of the skin tissue of mice wounds showed a significant reduction in the number of inflammatory cells in the PAW treatment group. To identify the possible mechanism by which PAW promotes wound healing, we analyzed changes in the profiles of wound bacteria after PAW treatment. The results show that PAW can significantly reduce the abundance of wound bacteria in the treatment group. The results of biochemical blood tests and histological analysis of major internal organs in the mice show that PAW had no obvious side effects. Taken together, these results indicate that PAW may be a new and effective method for promoting wound healing without side effects.

The myofibroblast at a glance

In 1971, Gabbiani and co-workers discovered and characterized the “modification of fibroblasts into cells which are capable of an active spasm” (contraction) in rat wound granulation tissue and, accordingly, named these cells ‘myofibroblasts’. Now, myofibroblasts are not only recognized for their physiological role in tissue repair but also as cells that are key in promoting the development of fibrosis in all organs. In this Cell Science at a Glance and the accompanying poster, we provide an overview of the current understanding of central aspects of myofibroblast biology, such as their definition, activation from different precursors, the involved signaling pathways and most widely used models to study their function. Myofibroblasts will be placed into context with their extracellular matrix and with other cell types communicating in the fibrotic environment. Furthermore, the challenges and strategies to target myofibroblasts in anti-fibrotic therapies are summarized to emphasize their crucial role in disease progression.

Adipose Tissue: A Source of Stem Cells with Potential for Regenerative Therapies for Wound Healing

Interest in adipose tissue is fast becoming a focus of research after many years of being considered as a simple connective tissue. It is becoming increasingly apparent that adipose tissue contains a number of diverse cell types, including adipose-derived stem cells (ASCs) with the potential to differentiate into a number of cell lineages, and thus has significant potential for developing therapies for regenerative medicine. Currently, there is no gold standard treatment for scars and impaired wound healing continues to be a challenge faced by clinicians worldwide. This review describes the current understanding of the origin, different types, anatomical location, and genetics of adipose tissue before discussing the properties of ASCs and their promising applications for tissue engineering, scarring, and wound healing.

PLGF-1 contained in normal wound myofibroblast-derived microvesicles stimulated collagen production by dermal fibroblasts

During the last stages of wound healing, myofibroblasts differentiate mainly from fibroblasts. Myofibroblasts from normal skin wounds (Wmyo) can communicate with its surrounding using secreted factors. They also have the capacity to produce microvesicles (MVs), a type of extracellular vesicles, as mediators of intercellular communication. MVs cargo are potentially capable of regulating the behavior of targeted cells and tissues. The aim of this study is to evaluate the effect of Wmyo-derived MVs on dermal fibroblasts and to determine the responsible signaling molecule. Microvesicles were obtained from culture media of myofibroblasts and characterized using protein quantification, dynamic light scattering and transmission electron microscopy. Uptake of fluorescent MVs in fibroblasts was assessed by flow cytometry. Cytokines concentrations were quantified in MV samples by a multiplex ELISA. Different concentration of MVs or a selected cytokine were used as treatments over fibroblasts culture for 5 days. Following the treatments, parameters linked to the extracellular matrix were studied. Lastly, the selected cytokine was neutralized within MVs before evaluating collagen production. We showed that Wmyo derived-MVs were internalized by dermal fibroblasts. Cytokine array analysis revealed that a large amount of placental growth factor 1 (PLGF-1) (0.88 ± 0.63 pg/μg proteins in MVs) could be detected in MVs samples. Cutaneous fibroblasts treated with MVs or PLGF-1 showed significantly stimulated procollagen I level production (Fold change of 1.80 ± 0.18 and 2.07 ± 0.18, respectively). Finally, the neutralization of PLGF-1 in MVs significantly inhibited the production of procollagen I by fibroblasts. Our study shows that Wmyo derived-MVs are involved in intercellular communication by stimulating collagen production by fibroblasts during wound healing. This effect is possibly attained through PLGF-1 signalling. These findings represent a promising opportunity to gain insight into how MVs and Wmyo may mediate the healing of a skin wound.

Skin Microcolumns as a Source of Paracrine Signaling Factors

Objective: We recently developed the approach of using “microcolumns” of autologous full-thickness skin tissue for wound repair. The small size of these micro skin tissue columns (MSTCs, ∼0.5 mm in diameter) allows donor sites to heal quickly without scarring. Treatment with MSTCs significantly accelerate wound healing, and suppled various skin cell types and skin structures to replenish the wound volume. This technology is now starting clinical use. In this study, we investigate whether MSTCs may also influence wound healing by releasing soluble signaling factors.

Approach: Freshly harvested MSTCs were incubated in culture medium for 24 h. The conditioned medium was collected and tested for its effects on migration and proliferation of human dermal fibroblasts, and its ability to induce tube formation by human umbilical vein endothelial cells (HUVECs). Proteins released into the conditioned medium were characterized by multiplex enzyme-linked immunosorbent assay (ELISA), and compared with medium conditioned by an equivalent mass of intact full-thickness skin.

Results: MSTC-conditioned medium increased fibroblast migration and proliferation, as well as HUVEC tube formation. MSTCs released many soluble factors known to play prominent roles in wound healing. A subset of proteins showed significantly different release profiles compared with intact full-thickness skin.

Innovation: The technology for harvesting and using MSTCs to augment wound healing was recently developed as an alternative to conventional autologous skin grafting. This study shows that MSTCs could also function as “cytokine factories.”

Conclusion: In addition to supplying autologous cells to repopulate the wound volume, MSTCs can also function as a source of growth factors and cytokines to further enhance wound healing.

Mesoglycan induces the secretion of microvesicles by keratinocytes able to activate human fibroblasts and endothelial cells: A novel mechanism in skin wound healing

Mesoglycan is a fibrinolytic compound but recently promising pro-healing effects in skin wound repair have been reported. Previously, we have showed that mesoglycan activates human keratinocytes, fibroblasts and endothelial cells and induces the secretion of microvesicles (EVs), particularly exosomes, from keratinocytes. These EVs may contribute to wound healing since they further activate cells generating an autocrine loop with a positive feedback. In this work, EVs isolated from keratinocytes, treated with mesoglycan, have been tested on human fibroblasts and endothelial cells. The in vitro investigation has been carried out through Wound-Healing/invasion assays to analyze cell motility and assess the differentiation process. Then, the formation of capillary-like structures by human endothelial cells has been performed to evaluate in vitro angiogenesis. We found that EVs secreted from keratinocytes treated with mesoglycan promote fibroblasts and endothelial cells migration and invasion. Furthermore, these receiving cells acquire a mesenchymal phenotype. Additionally, the angiogenesis appears strongly enhanced in presence of this kind of EVs. In conclusion, we show that EVs deriving from keratinocytes trigger a paracrine positive feedback able to further amplify the effects of mesoglycan. This mechanism adds up to the autocrine loop previously reported and culminates with the activation of fibroblasts and endothelial cells. Particularly, this activation is amplified by the action of growth factors as FGF-2 (Fibroblast Growth Factor-2) for the fibroblasts and by VEGF (Vascular Endothelial Growth Factor) for the endothelial cells.

Tumor-derived extracellular vesicles: molecular parcels that enable regulation of the immune response in cancer

Extracellular vesicles (EVs) are a heterogeneous collection of membrane-bound vesicles released by cells that contain bioactive cargoes including proteins, lipids and nucleic acids. Multiple subpopulations of EVs have now been recognized and these include exosomes and microvesicles. EVs have been thought to facilitate intercellular and distal communication to bring about various processes that enable tumor progression and metastases. Here, we describe the current knowledge of the functional cargo contained within EVs, with a focus on tumor microvesicles, and review the emerging theory of how EVs support immune suppression in cancer.

Annexin A1 Contained in Extracellular Vesicles Promotes the Activation of Keratinocytes by Mesoglycan Effects: An Autocrine Loop Through FPRs

We have recently demonstrated that mesoglycan, a fibrinolytic compound, may be a promising pro-healing drug for skin wound repair. We showed that mesoglycan induces migration, invasion, early differentiation, and translocation to the membrane of keratinocytes, as well as the secretion of annexin A1 (ANXA1), further involved in keratinocytes activation. These events are triggered by the syndecan-4 (SDC4)/PKCα pathway. SDC4 also participates to the formation and secretion of microvesicles (EVs) which may contribute to wound healing. EVs were isolated from HaCaT cells, as human immortalized keratinocytes, and then characterised by Western blotting, Field Emission-Scanning Electron Microscopy, and Dynamic Light Scattering. Their autocrine effects were investigated by Wound-Healing/invasion assays and confocal microscopy to analyse cell motility and differentiation, respectively. Here, we found that the mesoglycan increased the release of EVs which amplify its same effects. ANXA1 contained in the microvesicles is able to promote keratinocytes motility and differentiation by acting on Formyl Peptide Receptors (FPRs). Thus, the extracellular form of ANXA1 may be considered as a link to intensify the effects of mesoglycan. In this study, for the first time, we have identified an interesting autocrine loop ANXA1/EVs/FPRs in human keratinocytes, induced by mesoglycan.

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles: A novel therapeutic paradigm

Mesenchymal stem cells (MSCs) have been revealed to hold great potential for the development of new treatment approaches for various diseases. However, the clinical use of these cells is limited due to their tumorigenic effects. The therapeutic benefits of MSCs are largely dependent on paracrine factors including extracellular vesicles (EVs). EVs are nano-sized bilayer membrane structures containing lipids, microRNAs and proteins which play key roles in cell-to-cell communications. Because of their lower immunogenicity, tumorigenicity, and easier management, EVs have emerged as a new promising alternative to whole-cell therapy. Therefore, this paper reviews current preclinical studies on the use of EVs derived from human umbilical cord MSCs (hucMSCs) as a therapeutic approach in treatment of several diseases including neurological, cardiovascular, liver, kidney, and bone diseases as well as the cutaneous wound, inflammatory bowel disease, cancers, infertility, and other disorders.

Microvesicles from human adipose stem cells promote wound healing by optimizing cellular functions via AKT and ERK signaling pathways

BACKGROUND

Human adipose stem cells (ASCs) have emerged as a promising treatment paradigm for skin wounds. Recent works demonstrate that the therapeutic effect of stem cells is partially mediated by extracellular vesicles, which comprise exosomes and microvesicles. In this study, we investigate the regenerative effects of isolated microvesicles from ASCs and evaluate the mechanisms how ASC microvesicles promote wound healing.

METHODS

Adipose stem cell-derived microvesicles (ASC-MVs) were isolated by differential ultracentrifugation, stained by PKH26, and characterized by electron microscopy and dynamic light scattering (DLS). We examined ASC-MV effects on proliferation, migration, and angiogenesis of keratinocytes, fibroblasts, and endothelial cells both in vitro and in vivo. Next, we explored the underlying mechanisms by gene expression analysis and the activation levels of AKT and ERK signaling pathways in all three kinds of cells after ASC-MV stimulation. We then assessed the effect of ASC-MVs on collagen deposition, neovascularization, and re-epithelialization in an in vivo skin injury model.

RESULTS

ASC-MVs could be readily internalized by human umbilical vein endothelial cells (HUVECs), HaCAT, and fibroblasts and significantly promoted the proliferation, migration, and angiogenesis of these cells both in vitro and in vivo. The gene expression of proliferative markers (cyclin D1, cyclin D2, cyclin A1, cyclin A2) and growth factors (VEGFA, PDGFA, EGF, FGF2) was significantly upregulated after ASC-MV treatment. Importantly, ASC-MVs stimulated the activation of AKT and ERK signaling pathways in those cells. The local injection of ASC-MVs at wound sites significantly increased the re-epithelialization, collagen deposition, and neovascularization and led to accelerated wound closure.

CONCLUSIONS

Our data suggest that ASC-MVs can stimulate HUVEC, HaCAT, and fibroblast functions. ASC-MV therapy significantly accelerates wound healing, and the benefits of ASC-MVs may due to the involvement of AKT and ERK signaling pathways. This illustrates the therapeutic potential of ASC-MVs which may become a novel treatment paradigm for cutaneous wound healing.

Microvesicles as promising biological tools for diagnosis and therapy

INTRODUCTION

Shed by most cells, in response to a myriad of stimuli, extracellular vesicles (EVs) carry proteins, lipids, and various nucleic acids. EVs encompass diverse subpopulations differing for biogenesis and content. Among these, microvesicles (MVs) derived from plasma membrane, are key regulators of physiopathological cellular processes including cancer, inflammation and infection. This review is unique in that it focuses specifically on the MVs as a mediator of information transfer. In fact, few proteomic studies have rigorously distinguished MVs from exosomes. Areas covered: Aim of this review is to discuss the proteomic analyses of the MVs. Many studies have examined mixed populations containing both exosomes and MVs. We discuss MVs' role in cell-specific interactions. We also show their emerging roles in therapy and diagnosis. Expert commentary: We see MVs as therapeutic tools for potential use in precision medicine. They may also have potential for allowing the identification of new biomarkers. MVs represent an invaluable tool for studying the cell of origin, which they closely represent, but it is critical to build a repository with data from MVs to deepen our understanding of their molecular repertoire and biological functions.

Extracellular Vesicles: How Drug and Pathology Interfere With Their Biogenesis and Function

Extracellular vesicles (EV) are at the center of an intense activity of investigation, both for their possible employment as biomarkers of ongoing pathologic processes and for their broad range of biological activities. EV can promote tissue repair in very different pathologic settings, including hindlimb and myocardial ischemia. Importantly, the exact mode of action of EV is still partly understood, since they may act by modulating growth factors and cytokines, signaling pathways, and by transferring non-coding RNAs to target cells. However, the term EV identifies cell derived, enveloped particles very heterogeneous in size, composition, and biogenesis. Therefore, part of the controversies on the biological effects exerted by EV is a consequence of differences in methods of separation that result in the enrichment of different entities. Since technical challenges still hamper the highly specific sorting of different EV subpopulations, up to now only few investigators have tried to verify differences in the biological effects of specific EV subtypes. This review summarizes the current state of the art on the comprehension of mechanisms involved in EV biogenesis and release, which is a prerequisite for understanding and investigating the impact that pathology and drug therapy may exert on the secretion and composition of EV. Finally, we described both the mechanism involved in the modulation of EV secretion by drugs commonly used in patients affected by heart failure, and how pathophysiological mechanisms involved in heart disease modify EV secretion.