Essentials of extracellular vesicles: posters on basic and clinical aspects of extracellular vesicles

Comprehensive review of MS-based studies on N-glycoproteome and N-glycome of extracellular vesicles

Extracellular vesicles (EVs) are lipid bilayer-enclosed particles that can be released by all type of cells. Whereas, as one of the most common post-translational modifications, glycosylation plays a vital role in various biological functions of EVs, such as EV biogenesis, sorting, and cellular recognition. Nevertheless, compared with studies on RNAs or proteins, those investigating the glycoconjugates of EVs are limited. An in-depth investigation of N-glycosylation of EVs can improve the understanding of the biological functions of EVs and help to exploit EVs from different perspectives. The general focus of studies on glycosylation of EVs primarily includes isolation and characterization of EVs, preparation of glycoproteome/glycome samples and MS analysis. However, the low content of EVs and non-standard separation methods for downstream analysis are the main limitations of these studies. In this review, we highlight the importance of glycopeptide/glycan enrichment and derivatization owing to the low abundance of glycoproteins and the low ionization efficiency of glycans. Diverse fragmentation patterns and professional analytical software are indispensable for analysing glycosylation via MS. Altogether, this review summarises recent studies on glycosylation of EVs, revealing the role of EVs in disease progression and their remarkable potential as biomarkers.

Diversity of Intercellular Communication Modes: A Cancer Biology Perspective

From the moment a cell is on the path to malignant transformation, its interaction with other cells from the microenvironment becomes altered. The flow of molecular information is at the heart of the cellular and systemic fate in tumors, and various processes participate in conveying key molecular information from or to certain cancer cells. For instance, the loss of tight junction molecules is part of the signal sent to cancer cells so that they are no longer bound to the primary tumors and are thus free to travel and metastasize. Upon the targeting of a single cell by a therapeutic drug, gap junctions are able to communicate death information to by-standing cells. The discovery of the importance of novel modes of cell-cell communication such as different types of extracellular vesicles or tunneling nanotubes is changing the way scientists look at these processes. However, are they all actively involved in different contexts at the same time or are they recruited to fulfill specific tasks? What does the multiplicity of modes mean for the overall progression of the disease? Here, we extend an open invitation to think about the overall significance of these questions, rather than engage in an elusive attempt at a systematic repertory of the mechanisms at play.

Cell Death, by Any Other Name…

Studies trying to understand cell death, this ultimate biological process, can be traced back to a century ago. Yet, unlike many other fashionable research interests, research on cell death is more alive than ever. New modes of cell death are discovered in specific contexts, as are new molecular pathways. But what is "cell death", really? This question has not found a definitive answer yet. Nevertheless, part of the answer is irreversibility, whereby cells can no longer recover from stress or injury. Here, we identify the most distinctive features of different modes of cell death, focusing on the executive final stages. In addition to the final stages, these modes can differ in their triggering stimulus, thus referring to the initial stages. Within this framework, we use a few illustrative examples to examine how intercellular communication factors in the demise of cells. First, we discuss the interplay between cell-cell communication and cell death during a few steps in the early development of multicellular organisms. Next, we will discuss this interplay in a fully developed and functional tissue, the gut, which is among the most rapidly renewing tissues in the body and, therefore, makes extensive use of cell death. Furthermore, we will discuss how the balance between cell death and communication is modified during a pathological condition, i.e., colon tumorigenesis, and how it could shed light on resistance to cancer therapy. Finally, we briefly review data on the role of cell-cell communication modes in the propagation of cell death signals and how this has been considered as a potential therapeutic approach. Far from vainly trying to provide a comprehensive review, we launch an invitation to ponder over the significance of cell death diversity and how it provides multiple opportunities for the contribution of various modes of intercellular communication.

Extracellular Vesicles in Domestic Animals: Cellular Communication in Health and Disease

Apoptotic and healthy cells of domestic animals release membrane-enclosed particles from their plasma membrane. These special structures, called extracellular vesicles, play an important role in intercellular communication. In the past, it was believed that their function was mainly to dispose unwanted cell contents and to help maintain cell homeostasis. However, we now know that they have important roles in health and disease and have diagnostic value as well as great potential for therapy in veterinary medicine. Extracellular vesicles facilitate cellular exchanges by delivering functional cargo molecules to nearby or distant tissues. They are produced by various cell types and are found in all body fluids. Their cargo reflects the state of the releasing parent cell, and despite their small size, this cargo is extraordinarily complex. Numerous different types of molecules contained in vesicles make them an extremely promising tool in the field of regenerative veterinary medicine. To further increase research interest and discover their full potential, some of the basic biological mechanisms behind their function need to be better understood. Only then will we be able to maximize the clinical relevance for targeted diagnostic and therapeutic purposes in various domestic animal species.

Extracellular-Vesicle-Based Therapeutics in Neuro-Ophthalmic Disorders

Extracellular vesicles (EVs) have been recognized as promising candidates for developing novel therapeutics for a wide range of pathologies, including ocular disorders, due to their ability to deliver a diverse array of bioactive molecules, including proteins, lipids, and nucleic acids, to recipient cells. Recent studies have shown that EVs derived from various cell types, including mesenchymal stromal cells (MSCs), retinal pigment epithelium cells, and endothelial cells, have therapeutic potential in ocular disorders, such as corneal injury and diabetic retinopathy. EVs exert their effects through various mechanisms, including promoting cell survival, reducing inflammation, and inducing tissue regeneration. Furthermore, EVs have shown promise in promoting nerve regeneration in ocular diseases. In particular, EVs derived from MSCs have been demonstrated to promote axonal regeneration and functional recovery in various animal models of optic nerve injury and glaucoma. EVs contain various neurotrophic factors and cytokines that can enhance neuronal survival and regeneration, promote angiogenesis, and modulate inflammation in the retina and optic nerve. Additionally, in experimental models, the application of EVs as a delivery platform for therapeutic molecules has revealed great promise in the treatment of ocular disorders. However, the clinical translation of EV-based therapies faces several challenges, and further preclinical and clinical studies are needed to fully explore the therapeutic potential of EVs in ocular disorders and to address the challenges for their successful clinical translation. In this review, we will provide an overview of different types of EVs and their cargo, as well as the techniques used for their isolation and characterization. We will then review the preclinical and clinical studies that have explored the role of EVs in the treatment of ocular disorders, highlighting their therapeutic potential and the challenges that need to be addressed for their clinical translation. Finally, we will discuss the future directions of EV-based therapeutics in ocular disorders. Overall, this review aims to provide a comprehensive overview of the current state of the art of EV-based therapeutics in ophthalmic disorders, with a focus on their potential for nerve regeneration in ocular diseases.

Identification of the microRNA alterations in extracellular vesicles derived from human haemorrhoids

NEW FINDINGS

What is the central question of this study? What are the morphological features and microRNA (miRNA) expression features of extracellular vesicles (EVs) from haemorrhoids (Hae-EVs) and normal tissues? What are the potential functions of the differentially expressed (DE) miRNAs in Hae-EVs? What is the main finding and its importance? We present, for the first time, the morphological features and miRNA profile of human Hae-EVs. Four hundred and forty-seven significant DE-miRNAs were identified. Gene ontology and pathway analysis of the DE-miRNAs indicated diverse roles of the Hae-EVs through different pathways. Our findings provide EV-based pathological features and the underlying mechanism of haemorrhoids.

ABSTRACT

Extracellular vesicles (EVs) play important roles in many pathophysiologies as cell-to-cell communication vehicles. However, the features and potential functions of the EVs in haemorrhoids remain unclear. Therefore, we performed microRNA (miRNA) microarray analysis in EVs derived from haemorrhoid tissue to identify the profile of miRNAs in these EVs and predict their potential functions. We obtained typical EVs from both haemorrhoid and control tissues. Microarray analysis identified 447 miRNAs with significant differential expresssion (DE): 245 upregulated and 202 downregulated. The top three upregulated miRNAs in haemorrhoid EVs (Hae-EVs), namely miR-6741-3p, miR-6834-3p and miR-4254, were detected by RT-qPCR in both Hae-EVs and haemorrhoid tissues. Interestingly, we found a different expression pattern in the haemorrhoid tissues from that in Hae-EVs. The potential target genes of these DE-miRNAs were predicted by the miRWalk and miRDB databases. Gene ontology (GO) analysis of the target genes showed that the DE-miRNAs contributed mainly to protein kinase activity, transcriptional activity and ubiquitin-protein function. KEGG search found that the DE-miRNAs might regulate the MAPK and Ras signalling pathways. These findings revealed, for the first time, the miRNA profiles in Hae-EVs and provided potential targets and pathways involved in the pathological process.

Homogenous subpopulation of human mesenchymal stem cells and their extracellular vesicles restore function of endometrium in an experimental rat model of Asherman syndrome

BACKGROUND

Asherman syndrome (AS), or intrauterine adhesions, is a main cause of infertility in reproductive age women after endometrial injury. Mesenchymal stem cells (MSCs) and their extracellular vesicles (EVs) are promising candidates for therapies that repair damaged endometria. However, concerns about their efficacy are attributed to heterogeneity of the cell populations and EVs. A homogenous population of MSCs and effective EV subpopulation are needed to develop potentially promising therapeutic options in regenerative medicine.

METHODS

AS model was induced by mechanical injury in adult rat uteri. Then, the animals were treated immediately with homogeneous population of human bone marrow-derived clonal MSCs (cMSCs), heterogenous parental MSCs (hMSCs), or cMSCs-derived EV subpopulations (EV20K and EV110K). The animals were sacrificed two weeks post-treatment and uterine horns were collected. The sections were taken, and hematoxylin-eosin was used to examine the repair of endometrial structure. Fibrosis was measured by Masson's trichrome staining and α-SMA and cell proliferation by Ki67 immunostaining. The function of the uteri was explored by the result of mating trial test. Expression changes of TNFα, IL-10, VEGF, and LIF were assayed by ELISA.

RESULTS

Histological analysis indicated fewer glands, thinner endometria, increased fibrotic areas, and decreased proliferation of epithelial and stroma of the uteri in the treated compared with intact and sham-operated animals. However, these parameters improved after transplantation of both types of cMSCs and hMSCs and/or both cryopreserved EVs subpopulations. The cMSCs demonstrated more successful implantation of the embryos in comparison with hMSCs. The tracing of the transplanted cMSCs and EVs showed that they migrated and localized in the uteri. Protein expression analysis results demonstrated downregulation of proinflammatory factor TNFα and upregulation of anti-inflammatory cytokine IL-10, and endometrial receptivity cytokines VEGF and LIF in cMSC- and EV20K-treated animals.

CONCLUSION

Transplantation of MSCs and EVs contributed to endometrial repair and restoration of reproductive function, likely by inhibition of excessive fibrosis and inflammation, enhancement of endometrial cell proliferation, and regulation of molecular markers related to endometrial receptivity. Compared to classical hMSCs, cMSCs were more efficient than hMSCs in restoration of reproductive function. Moreover, EV20K is more cost-effective and feasible for prevention of AS in comparison with conventional EVs (EV110K).

Characterization of large extracellular vesicles (L-EV) derived from human regulatory macrophages (Mreg): novel mediators in wound healing and angiogenesis?

BACKGROUND

Large extracellular vesicles (L-EV) with a diameter between 1 and 10 µm are released by various cell types. L-EV contain and transport active molecules which are crucially involved in cell to cell communication. We have shown that secretory products of human regulatory macrophages (Mreg) bear pro-angiogenic potential in-vitro and our recent findings show that Mreg cultures also contain numerous large vesicular structures similar to L-EV with so far unknown characteristics and function.

AIM OF THIS STUDY

To characterize the nature of Mreg-derived L-EV (L-EV_Mreg) and to gain insights into their role in wound healing and angiogenesis.

METHODS

Mreg were differentiated using blood monocytes from healthy donors (N = 9) and L-EV_Mreg were isolated from culture supernatants by differential centrifugation. Characterization of L-EV_Mreg was performed by cell/vesicle analysis, brightfield/transmission electron microscopy (TEM), flow cytometry and proteome profiling arrays. The impact of L-EV_Mreg on wound healing and angiogenesis was evaluated by means of scratch and in-vitro tube formation assays.

RESULTS

Mreg and L-EV_Mreg show an average diameter of 13.73 ± 1.33 µm (volume: 1.45 ± 0.44 pl) and 7.47 ± 0.75 µm (volume: 0.22 ± 0.06 pl) respectively. Flow cytometry analyses revealed similarities between Mreg and L-EV_Mreg regarding their surface marker composition. However, compared to Mreg fewer L-EV_Mreg were positive for CD31 (P < 0.01), CD206 (P < 0.05), CD103 (P < 0.01) and CD45 (P < 0.05). Proteome profiling suggested that L-EV_Mreg contain abundant amounts of pro-angiogenic proteins (i.e. interleukin-8, platelet factor 4 and serpin E1). From a functional point of view L-EV_Mreg positively influenced in-vitro wound healing (P < 0.05) and several pro-angiogenic parameters in tube formation assays (all segment associated parameters, P < 0.05; number of meshes, P < 0.05).

CONCLUSION

L-EV_Mreg with regenerative and pro-angiogenic potential can be reproducibly isolated from in-vitro cultured human regulatory macrophages. We propose that L-EV_Mreg could represent a putative therapeutic option for the treatment of chronic wounds and ischemia-associated diseases.

Dendritic cells originating exosomal miR-193b-3p induces regulatory T cells to alleviate liver transplant rejection

BACKGROUND

Exosomes exert considerable influence in mediating regulatory T (Treg) cells differentiation, which attach great importance to attenuating acute cellular rejection after liver transplantation (LT). And, miRNAs are known to play essential roles in cell-cell communication delivered by exosomes. However, the function of exosomal miRNAs in regulating Treg cells after LT remains unknown. Here, we performed an expression profiling analysis of exosome-miRNAs from human plasma after LT and investigated their immunoregulatory effects on Treg cells.

METHODS

Fifty-eight LT patients and nine donors were included in this report. miRNA profiles in plasma exosomes were analyzed using next-generation sequencing. Flow cytometry, HE and multiplex immunofluorescent staining were used to identify Treg cells in the liver and peripheral blood. A lentiviral vector system was used to overexpress miR-193b-3p in dendritic cells (DCs), and exosomes isolated from these transfected cells were co-cultured with spleen lymphocytesin vitro. A quantitative Real-time PCR and enzyme-linked immunosorbent assay were used to detect the expression of cytokines.

RESULTS

Treg cell infiltration was increased in the liver along with Th17 and CD8+ T cell, and it was down-regulated in peripheral blood in the acute rejection group. High-throughput sequencing revealed that miR-193b-3p was markedly up-regulated in plasma exosomes of non-rejection LT patients. The NLRP3 inflammasome was screened as a target for miR-193b-3p based on target prediction and functional enrichment analyses. Exosomal miR-193b-3p derived from DCs increased Treg cells as demonstrated in vitro. miR-193b-3p overexpression down-regulated NLRP3 as well as the inflammatory cytokines IL-1β and IL-17A while increasing levels of the cytokines IL-10 and TGF-β.

CONCLUSION

DC derived exosomal miR-193b-3p promoted Treg cells by inhibiting NLRP3 expression. These findings not only provide a new perspective on the mechanisms, but also hold great promise for the treatment or prevention of liver allograft rejection.

Alterations of long noncoding RNAs and mRNAs in extracellular vesicles derived from the murine heart post-ischemia-reperfusion injury

Extracellular vesicles (EVs) play important roles in cardiovascular diseases by delivering their RNA cargos. However, the features and possible role of the lncRNAs and mRNAs in cardiac EVs during ischemia-reperfusion (IR) remain unclear. Therefore, we performed RNA sequencing analysis to profile the features of lncRNAs and mRNAs and predicted their potential functions. Here, we demonstrated that the severity of IR injury was significantly correlated with cardiac EV production. RNA sequencing identified 73 significantly differentially expressed (DE) lncRNAs (39 upregulated and 34 downregulated) and 720 DE-mRNAs (317 upregulated and 403 downregulated). Gene Ontology (GO) and pathway analysis were performed to predict the potential functions of the DE-lncRNAs and mRNAs. The lncRNA-miRNA-mRNA ceRNA network showed the possible functions of DE-lncRNAs with DE-mRNAs which are enriched in the pathways of T cell receptor signalling pathway and cell adhesion molecules. Moreover, the expressions of ENSMUST00000146010 and ENSMUST00000180630 were negatively correlated with the severity of IR injury. A significant positive correlation was revealed between TCONS_00010866 expression and the severity of the cardiac injury. These findings revealed the lncRNA and mRNA profiles in the heart derived EVs and provided potential targets and pathways involved in cardiac IR injury.

Next generation of neurological therapeutics: Native and bioengineered extracellular vesicles derived from stem cells

Extracellular vesicles (EVs)-based cell-free therapy, particularly stem cell-derived extracellular vesicles (SC-EVs), offers new insights into treating a series of neurological disorders and becomes a promising candidate for alternative stem cell regenerative therapy. Currently, SC-EVs are considered direct therapeutic agents by themselves and/or dynamic delivery systems as they have a similar regenerative capacity of stem cells to promote neurogenesis and can easily load many functional small molecules to recipient cells in the central nervous system. Meanwhile, as non-living entities, SC-EVs avoid the uncontrollability and manufacturability limitations of live stem cell products in vivo (e.g., low survival rate, immune response, and tumorigenicity) and in vitro (e.g., restricted sources, complex preparation processes, poor quality control, low storage, shipping instability, and ethical controversy) by strict quality control system. Moreover, SC-EVs can be engineered or designed to enhance further overall yield, increase bioactivity, improve targeting, and extend their half-life. Here, this review provides an overview on the biological properties of SC-EVs, and the current progress in the strategies of native or bioengineered SC-EVs for nerve injury repairing is presented. Then we further summarize the challenges of recent research and perspectives for successful clinical application to advance SC-EVs from bench to bedside in neurological diseases.

Apoptotic bodies for advanced drug delivery and therapy

Extracellular vesicles (EVs) have emerged as promising candidates for multiple biomedical applications. Major types of EVs include exosomes, microvesicles, and apoptotic bodies (ABs). ABs are conferred most properties from parent cells in the final stages of apoptosis. A wide variety of sources and stable morphological features are endowed to ABs by the rigorous apoptotic program. ABs accommodate more functional biomolecules by relying on the larger volume and maintaining their naturalness in circulation. The predominant body surface ratio of ABs facilitates their recognition by recipient cells and is advantageous for interactions with microenvironments. ABs can modulate and alleviate symptoms of numerous diseases for their origins, circulation, and high biocompatibility. In addition, ABs have been emerging in disease diagnosis, immunotherapy, regenerative therapy, and drug delivery. Here, we aim to present a thorough discussion on current knowledge about ABs. Of particular interest, we will summarize the application of AB-based strategies for diagnosis and disease therapy. Perspectives for the development of ABs in biomedical applications are highlighted.

sncRNAs in Epididymosomes: The Contribution to Embryonic Development and Offspring Health

Much progress has been made in determining that paternal environmental exposures can remodel their spermatozoa small noncoding RNAs (sncRANs) and, in turn, affect the phenotypes of their offspring. Studies have shown that changes in the spermatozoa sncRNAs profile occur during passing through the epididymis. Due to the absence of transcription and translation in the epididymis, spermatozoa remodel their sncRNAs profile through communication with the epididymal microenvironment. Since epididymosomes contribute to the process of spermatozoa maturation by mediating the crosstalk between the epididymis and the passing spermatozoa, they are considered to be the leading candidate to mediate these changes. Previous studies and reviews on the role of epididymal transfer proteins in sperm maturation and function are myriad. This review focuses on the role and mechanisms of epididymosome-mediated transfer of sncRNAs cargoes onembryonic development and offspring health.

Theragnostic Applications of Mammal and Plant-Derived Extracellular Vesicles: Latest Findings, Current Technologies, and Prospects

The way cells communicate is not fully understood. However, it is well-known that extracellular vesicles (EVs) are involved. Researchers initially thought that EVs were used by cells to remove cellular waste. It is now clear that EVs function as signaling molecules released by cells to communicate with one another, carrying a cargo representing the mother cell. Furthermore, these EVs can be found in all biological fluids, making them the perfect non-invasive diagnostic tool, as their cargo causes functional changes in the cells upon receiving, unlike synthetic drug carriers. EVs last longer in circulation and instigate minor immune responses, making them the perfect drug carrier. This review sheds light on the latest development in EVs isolation, characterization and, application as therapeutic cargo, novel drug loading techniques, and diagnostic tools. We also address the advancement in plant-derived EVs, their characteristics, and applications; since plant-derived EVs only recently gained focus, we listed the latest findings. Although there is much more to learn about, EV is a wide field of research; what scientists have discovered so far is fascinating. This paper is suitable for those new to the field seeking to understand EVs and those already familiar with it but wanting to review the latest findings.

Biorepository - A key component of research studies

The last two decades have shown impressive advances in high-throughput assays for gene expression (genomics), proteins (proteomics), and metabolites (metabolomics). As a result, the quest for an equivalent need for human biological samples has increased exponentially. Translational investigations require good quality specimens to guarantee research results' integrity, probity, and reproducibility. A biorepository is a bank of specimens or specimens-derived neosamples (e.g., organoids, nucleic acids) linked to a database containing information related to these specimens. Two requirements must be met to safeguard the authenticity and stability of such a repository. First, the information provided should comprise relevant clinical and therapeutic communication, and second, the chain of custody is assured, guarded, versatile, and accessible. Completing these requirements is crucial for consistency, accuracy, verifiability, and disclosability of scientific and clinical outcomes. This commentary emphasizes that advocacy for standardization of operational workflows is a sine qua non for good science. Safe procedures for clinical trials are crucial to maintaining biorepositories' validity for all researchers.

A brief history of nearly EV-erything - The rise and rise of extracellular vesicles

Extracellular vesicles (EVs) are small cargo-bearing vesicles released by cells into the extracellular space. The field of EVs has grown exponentially over the past two decades; this growth follows the realisation that EVs are not simply a waste disposal system as had originally been suggested by some, but also a complex cell-to-cell communication mechanism. Indeed, EVs have been shown to transfer functional cargo between cells and can influence several biological processes. These small biological particles are also deregulated in disease. As we approach the 75th anniversary of the first experiments in which EVs were unknowingly isolated, it seems right to take stock and look back on how the field started, and has since exploded into its current state. Here we review the early experiments, summarise key findings that have propelled the field, describe the growth of an organised EV community, discuss the current state of the field, and identify key challenges that need to be addressed.

Transfusion‑related immunomodulation in patients with cancer: Focus on the impact of extracellular vesicles from stored red blood cells (Review)

Red blood cell (RBC) transfusions may have a negative impact on the prognosis of patients with cancer, where transfusion‑related immunomodulation (TRIM) may be a significant contributing factor. A number of components have been indicated to be associated with TRIM. Among these, the impact of extracellular vesicles (EVs) has been garnering increasing attention from researchers. EVs are defined as nano‑scale, cell‑derived vesicles that carry a variety of bioactive molecules, including proteins, nucleic acids and lipids, to mediate cell‑to‑cell communication and exert immunoregulatory functions. RBCs in storage constitutively secrete EVs, which serve an important role in TRIM in patients with cancer receiving a blood transfusion. Therefore, the present review aimed to first summarize the available information on the biogenesis and characterization of EVs. Subsequently, the possible mechanisms of TRIM in patients with cancer and the impact of EVs on TRIM were discussed, aiming to provide an outlook for future studies, specifically for formulating recommendations for managing patients with cancer receiving RBC transfusions.

Liquid Biopsy: A Family of Possible Diagnostic Tools

Liquid biopsies could be considered an excellent diagnostic tool, in different physiological or pathological conditions. The possibility of using liquid biopsies for non-invasive clinical purposes is quite an old idea: indeed many years ago it was already being used in the field of non-invasive prenatal tests (NIPT) for autosomal fetal aneuploidy evaluation. In 1997 Lo et al. had identified fetal DNA in maternal plasma and serum, showing that about 10–15% of cfDNA in maternal plasma is derived from the placenta, and biologic fluid represents an important and non-invasive technique to evaluate state diseases and possible therapies. Nowadays, several body fluids, such as blood, urine, saliva and other patient samples, could be used as liquid biopsy for clinical non-invasive evaluation. These fluids contain numerous and various biomarkers and could be used for the evaluation of pathological and non-pathological conditions. In this review we will analyze the different types of liquid biopsy, their potential role in clinical diagnosis and the functional involvement of extracellular vesicles in these fluids as carriers.

Plasma exosomal miR-375-3p regulates mitochondria-dependent keratinocyte apoptosis by targeting XIAP in severe drug-induced skin reactions

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe drug-induced cutaneous reactions characterized by keratinocyte apoptosis. Exosomes are nanometer-sized membranous vesicles in body fluids. They contain functional proteins, mRNAs, and miRNAs, which induce immune dysfunction and influence disease progression. However, their roles and mechanisms in SJS/TEN remain unknown. Our results demonstrate that exosomes isolated from the plasma of patients with SJS/TEN were 30 to 200 nm in diameter and expressed CD9, CD63, CD81, and TSG101 exosome marker proteins. miR-375-3p was markedly up-regulated in 35 patients with SJS/TEN and correlated with clinical severity. Plasma exosomes were internalized by human primary keratinocytes and promoted keratinocyte apoptosis in vitro. Furthermore, miR-375-3p overexpression promoted intrinsic (mitochondria-dependent) apoptosis of human primary keratinocytes via down-regulation of the X-linked inhibitor of apoptosis protein (XIAP), a key apoptosis regulator in primary human keratinocytes. In sum, our study indicates that the circulating exosomal miR-375-3p enters keratinocytes, down-regulates XIAP, and induces keratinocyte apoptosis in patients with SJS/TEN.

Extracellular Vesicles: An Emerging Regenerative Treatment for Oral Disease

Extracellular Vesicles (EVs) are small lipid-enclosed particles containing biological molecules such as RNA and proteins that have emerged as vital modulators of intercellular communication. Increasingly, studies have shown that EVs play an essential role in the occurrence and prognosis of oral diseases. EVs are increasingly considered a research hotspot of oral diseases. In addition, the characteristics of carrying active molecules have also been studied in oral tissue regeneration. Evidence has shown that EVs regulate the homeostasis of the inflammatory microenvironment, promote angiogenesis, and repair damaged tissues. In this review, we summarized the characteristics of EVs and highlighted the role of EVs in oral tissue regeneration, including dental pulp, periodontal tissue, cartilage, and bone. We also discussed their deficiencies and prospects as a potential therapeutic role in the regeneration treatment of oral disease.

Extracellular Vesicles in chondrogenesis and Cartilage regeneration

Extracellular vesicles (EVs), mainly exosomes and microvesicles, are bilayer lipids containing biologically active information, including nucleic acids and proteins. They are involved in cell communication and signalling, mediating many biological functions including cell growth, migration and proliferation. Recently, EVs have received great attention in the field of tissue engineering and regenerative medicine. Many in vivo and in vitro studies have attempted to evaluate the chondrogenesis potential of these microstructures and their roles in cartilage regeneration. EVs derived from mesenchymal stem cells (MSCs) or chondrocytes have been found to induce chondrocyte proliferation and chondrogenic differentiation of stem cells in vitro. Preclinical studies have shown that exosomes derived from MSCs have promising results in cartilage repair and in cell‐free therapy of osteoarthritis. This review will focus on the in vitro and in vivo chondrogenesis and cartilage regeneration of EVs as well as their potential in the treatment of osteoarthritis.

Stem/progenitor cell in kidney: characteristics, homing, coordination, and maintenance

Renal failure has a high prevalence and is becoming a public health problem worldwide. However, the renal replacement therapies such as dialysis are not yet satisfactory for its multiple complications. While stem/progenitor cell-mediated tissue repair and regenerative medicine show there is light at the end of tunnel. Hence, a better understanding of the characteristics of stem/progenitor cells in kidney and their homing capacity would greatly promote the development of stem cell research and therapy in the kidney field and open a new route to explore new strategies of kidney protection. In this review, we generally summarize the main stem/progenitor cells derived from kidney in situ or originating from the circulation, especially bone marrow. We also elaborate on the kidney-specific microenvironment that allows stem/progenitor cell growth and chemotaxis, and comment on their interaction. Finally, we highlight potential strategies for improving the therapeutic effects of stem/progenitor cell-based therapy. Our review provides important clues to better understand and control the growth of stem cells in kidneys and develop new therapeutic strategies.

[Gly14]-Humanin Ameliorates High Glucose-Induced Apoptosis by Inhibiting the Expression of MicroRNA-155 in Endothelial Microparticles

BACKGROUND

Humanin, a newly emerging endogenously expressed cytoprotective peptide, has been shown to have anti-apoptotic properties effects by protecting neuronal cells injury. Endothelial microparticles (EMPs) are considered as vital mediators in intercellular communication. EMPs may regulate various physiological and pathological processes by transferring mRNAs and microRNAs (miRNAs) to recipient cells.

METHODS

EMPs were isolated from human umbilical vein endothelial cells (HUVECs) by ultracentrifugation. EMPs were characterized by transmission electron microscopy and nanoparticle tracking analyses. Observation of EMPs uptake into HUVECs and the number of EMPs were realized by confocal microscopy. The expression of miR-155 was examined using real-time PCR. Cell apoptosis was examined by flow cytometry assay.

RESULTS

We found that high glucose (HG) increased the number of EMPs and upregulated the expression of miR-155 contained within EMPs, which was mitigated by HNG pretreatment. miR-155 overexpression in EMPs reversed the effects of HNG pretreatment and increased apoptosis of target cells. Effects of HNG pretreatment on HG-treated endothelial cells (ECs) were mitigated after miR-155 mimic transfection into HUVECs while were augmented after miR-155 inhibitor transfection into HUVECs.

CONCLUSION

HNG inhibited HG-induced apoptosis of ECs and the effect of HNG may be mediated by inhibiting the transfer of EMPs miR-155 from HG-induced HUVECs to normal cells. This study provides a new direction for biological products related to humanin to treat vascular complications associated with all forms of diabetes mellitus.

MicroRNAs As Master Regulators of Atherosclerosis: From Pathogenesis to Novel Therapeutic Options

Significance: Cardiovascular disease (CVD) remains the major cause of morbidity and mortality worldwide. Accumulating evidence indicates that atherosclerosis and its sequelae, coronary artery disease, contribute to the majority of cardiovascular deaths. Atherosclerosis is a chronic inflammatory disease of the arteries in which atherosclerotic plaques form within the vessel wall. Epidemiological studies have identified various risk factors for atherosclerosis, such as diabetes, hyperlipidemia, smoking, genetic predisposition, and sedentary lifestyle. Recent Advances: Through the advancement of genetic manipulation techniques and their use in cardiovascular biology, it was shown that small RNAs, especially microRNAs (miRNAs), are dynamic regulators of disease pathogenesis. They are considered to be central during the regulation of gene expression through numerous mechanisms and provide a means to develop biomarkers and therapeutic tools for the diagnosis and therapy of atherosclerosis. Circulating miRNAs encapsulated within membrane-surrounded vesicles, which originate from diverse subcellular compartments, are now emerging as novel regulators of intercellular communication. The miRNAs, in both freely circulating and vesicle-bound forms, represent a valuable tool for diagnosing and monitoring CVD, recently termed as "liquid biopsy." Critical Issues: However, despite the recent advancements in miRNA-based diagnostics and therapeutics, understanding how miRNAs can regulate atherosclerosis is still crucial to achieving an effective intervention and reducing the disease burden. Future Directions: We provide a landscape of the current developmental progression of RNA therapeutics as a holistic approach for treating CVD in different animal models and clinical trials. Future interrogations are warranted for the development of miRNA-based therapeutics to overcome challenges for the treatment of the disease.

Extracellular Vesicles Derived from Senescent Fibroblasts Attenuate the Dermal Effect on Keratinocyte Differentiation

The skin is a multilayered and primary defensive organ. Intimate intercellular communication in the skin is necessary to ensure effective surveillance. Extracellular vesicles (EVs) are being explored for their involvement in intercellular skin communication. The aim of this study was to evaluate how human dermal fibroblasts (HDFs) accelerate EV production during senescence and the effects of senescence-associated EVs on epidermal homeostasis. Replicative senescent HDFs were assessed with senescence-associated β-galactosidase staining and the expression of senescence-related markers. Isolated EVs were characterized by dynamic light scattering and EV marker expression. EVs secreted from untreated young or senescent HDFs, or from those treated with a nSMase inhibitor, antioxidant, and lysosomal activity regulators, were determined by sandwich ELISA for CD81. Human epidermal keratinocytes were treated with young- and senescent HDF-derived EVs. Compared to young HDFs, senescent HDFs produced relatively high levels of EVs due to the increased nSMase activity, oxidative stress, and altered lysosomal activity. The nSMase inhibitor, antioxidant, and agents that recovered lysosomal activity reduced EV secretion in senescent HDFs. Relative to young HDF-derived EVs, senescent HDF-derived EVs were less supportive in keratinocyte differentiation and barrier function but increased proinflammatory cytokine IL-6 levels. Our study suggests that dermis-derived EVs may regulate epidermal homeostasis by reflecting cellular status, which provides insight as to how the dermis communicates with the epidermis and influences skin senescence.

Apoptotic Bodies: Particular Extracellular Vesicles Involved in Intercellular Communication

In the last decade, a new method of cell-cell communication mediated by membranous extracellular vesicles (EVs) has emerged. EVs, including exosomes, microvesicles, and apoptotic bodies (ApoBDs), represent a new and important topic, because they are a means of communication between cells and they can also be involved in removing cellular contents. EVs are characterized by differences in size, origin, and content and different types have different functions. They appear as membranous sacs released by a variety of cells, in different physiological and patho-physiological conditions. Intringuingly, exosomes and microvesicles are a potent source of genetic information carriers between different cell types both within a species and even across a species barrier. New, and therefore still relatively poorly known vesicles are apoptotic bodies, on which numerous in-depth studies are needed in order to understand their role and possible function. In this review we would like to analyze their morpho-functional characteristics.

MiR155-5p in adventitial fibroblasts-derived extracellular vesicles inhibits vascular smooth muscle cell proliferation via suppressing angiotensin-converting enzyme expression

Proliferation of vascular smooth muscle cells (VSMCs) plays crucial roles in vascular remodelling and stiffening in hypertension. Vascular adventitial fibroblasts are a key regulator of vascular wall function and structure. This study is designed to investigate the roles of adventitial fibroblasts-derived extracellular vesicles (EVs) in VSMC proliferation and vascular remodelling in normotensive Wistar-Kyoto rat (WKY) and spontaneously hypertensive rat (SHR), an animal model of human essential hypertension. EVs were isolated from aortic adventitial fibroblasts of WKY (WKY-EVs) and SHR (SHR-EVs). Compared with WKY-EVs, miR155-5p content was reduced, while angiotensin-converting enzyme (ACE) content was increased in SHR-EVs. WKY-EVs inhibited VSMC proliferation of SHR, which was prevented by miR155-5p inhibitor. SHR-EVs promoted VSMC proliferation of both strains, which was enhanced by miR155-5p inhibitor, but abolished by captopril or losartan. Dual luciferase reporter assay showed that ACE was a target gene of miR155-5p. MiR155-5p mimic or overexpression inhibited VSMC proliferation and ACE upregulation of SHR. WKY-EVs reduced ACE mRNA and protein expressions while SHR-EVs only increased ACE protein level in VSMCs of both strains. However, the SHR-EVs-derived from the ACE knockdown-treated adventitial fibroblasts lost the roles in promoting VSMC proliferation and ACE upregulation. Systemic miR155-5p overexpression reduced vascular ACE, angiotensin II and proliferating cell nuclear antigen levels, and attenuated hypertension and vascular remodelling in SHR. Repetitive intravenous injection of SHR-EVs increased blood pressure and vascular ACE contents, and promoted vascular remodelling in both strains, while WKY-EVs reduced vascular ACE contents and attenuated hypertension and vascular remodelling in SHR. We concluded that WKY-EVs-mediated miR155-5p transfer attenuates VSMC proliferation and vascular remodelling in SHR via suppressing ACE expression, while SHR-EVs-mediated ACE transfer promotes VSMC proliferation and vascular remodelling.

Exosomes in specific fractions of the boar ejaculate contain CD44: A marker for epididymosomes?

Seminal plasma (SP) is a complex fluid containing proteins, peptides, enzymes, hormones as well as extracellular vesicles (EVs). The SP interacts with spermatozoa and the inner cell lining of the female genital tract, adsorbing proteins and exosomes that modulate sperm functions and female immune responsiveness. In the present study, boar sperm-free SP was studied using flow cytometry (FC) after membrane tetraspanins (CD9, CD63 and CD81) and membrane receptor CD44 marking of non-enriched (whole SP) or gradient fractions enriched through two-step discontinuous KBr-density-gradient ultracentrifugation, in whole ejaculate or in selected ejaculate fractions. The results, evaluated by transmission electron microscopy, confirmed the presence of exosomes in all fractions of the pig SP. Noteworthy, these pig SP-exosomes were CD44-bearing when analysed by FC, with bands detected by western blotting (WB) at the expected 85 kD size. The two-step discontinuous KBr-density-gradient ultracentrifugation enriched the population of exosomes in two specific gradient fractions, indicating exosomes (either prostasomes or epididymosomes) could be separated from low-density lipoprotein (LDL) but they co-sediment with the high-density lipoprotein (HDL)-bearing fraction. The findings pave for the selective isolation of exosomes in functional studies of their function when interacting with spermatozoa, the oocyte and/or the female genitalia, including hyaluronan-CD44 interplay.

Extracellular vesicles isolated from porcine seminal plasma exhibit different tetraspanin expression profiles

Seminal extracellular vesicles (EVs) include exosomes (ø 40–120 nm) and microvesicles (MVs, ø 120–1000 nm), which would be involved in multiple functional reproductive roles. The study aimed to establish which EV subtypes are present in pig semen, using a high-resolution flow cytometer to explore differences in their tetraspanin expression profile. The EVs were isolated from 12 pig ejaculates using serial ultracentrifugation and characterized by dynamic light scattering and electron microscopy for size and morphology as well as for tetraspanin expression using flow cytometry with Carboxyfluorescein succinimidyl ester (CFSE) and antibodies against CD9, CD63 and CD81. Pig semen contained a heterogeneous EV-population regarding size and morphology. Flow cytometric analysis demonstrated that the proportion of EVs expressing CD63 and CD9 was higher in MVs (P < 0.001 and P < 0.05, respectively) than in exosomes, while the opposite was true for CD81; higher (P < 0.001) in exosomes than in MVs. In conclusion, (1) the new generation of flow cytometers are able to accurately identify EVs and to gate them in two size-different populations named exosomes and MVs. (2) Tetraspanins CD9, CD63 and CD81 are present in both seminal EVs, albeit with exosomes and MVs differing in expression profiles, suggesting dissimilar cargo and binding affinity.

Bovine Milk Extracellular Vesicles (EVs) Modification Elicits Skeletal Muscle Growth in Rats

The current study investigated how bovine milk extracellular vesicles (EVs) affected rotarod performance and biomarkers of skeletal muscle physiology in young, growing rats. Twenty-eight-day Fisher 344 rats were provided an AIN-93G-based diet for 4 weeks that either remained unadulterated [EVs and RNA-sufficient (ERS; n = 12)] or was sonicated [EVs and RNA-depleted (ERD; n = 12)]. Prior to (PRE) and on the last day of the intervention (POST), animals were tested for maximal rotarod performance. Following the feeding period, the gastrocnemius muscle was analyzed at the histological, biochemical, and molecular levels and was also used to measure mitochondrial function and reactive oxygen species (ROS) emission. A main effect of time was observed for rotarod time (PRE > POST, p = 0.001). Terminal gastrocnemius mass was unaffected by diet, although gastrocnemius muscle fiber cross sectional area was 11% greater (p = 0.018) and total RNA (a surrogate of ribosome density) was 24% greater (p = 0.001) in ERD. Transcriptomic analysis of the gastrocnemius indicated that 22 mRNAs were significantly greater in ERS versus ERD (p < 0.01), whereas 55 mRNAs were greater in ERD versus ERS (p < 0.01). There were no differences in gastrocnemius citrate synthase activity or mitochondrial coupling (respiratory control ratio), although mitochondrial ROS production was lower in ERD gastrocnemius (p = 0.016), which may be explained by an increase in glutathione peroxidase protein levels (p = 0.020) in ERD gastrocnemius. Dietary EVs profiling confirmed that sonication in the ERD diet reduced EVs content by ∼60%. Our findings demonstrate that bovine milk EVs depletion through sonication elicits anabolic and transcriptomic effects in the gastrocnemius muscle of rapidly maturing rats. While this did not translate into a functional outcome between diets (i.e., rotarod performance), longer feeding periods may be needed to observe such functional effects.