Non-coding RNAs in Mesenchymal Stem Cell-Derived Extracellular Vesicles: Deciphering Regulatory Roles in Stem Cell Potency, Inflammatory Resolve, and Tissue Regeneration

An assessment of economy- and transport-oriented health performance

BACKGROUND

Good health can prolong one's lifespan and is a fundamental human right. Thus, human health is being influenced by prejudiced from sociological, environmental, economic, and geographic aspects. The economy and transportation system pose a serious challenge to the assessment of the health performance of economies.

OBJECTIVE

This study aims to assess the health performance of Organization for Economic Cooperation and Development (OECD) economies by using economic and transport-related indicators and examining the role of health expenditure and governance in improving efficiency.

METHODS

This study measures the economy- and transport-oriented health efficiency of 35 OECD economies for the period of 2000-2022. In the first stage, this study employs a slacks-based measure and the data envelopment analysis-window analysis approach to conduct individual (economy and transportation) and joint assessments to measure health efficiency. In the second stage, this study uses the tobit regression method to investigate the effects of influencing factors, namely, government general health and pharmaceutical expenditures, the medical infrastructure, and governance, on health efficiency.

RESULTS

Empirical results reveal that a 1-unit change in the health expenditure during the research period improves economy-oriented health efficiency by 71% and transport-oriented health efficiency by 58%. The econometric analysis demonstrates that all the coefficients of economy- and transport-oriented health efficiency are significant and positive. Notably, a 1-unit change in the medical infrastructure increases economy- and transport-oriented health efficiency by 50.8%, and a 1% increase in pharmaceutical expenditure increases the health, economy, and transport efficiency scores by 16.3%, 33%, and 58.6%, respectively.

CONCLUSIONS

The findings suggest that some of the economies were efficient with regard to their health-oriented outputs, that is, quality of life and mortality and morbidity rates, and most of the economies demonstrated excellent economic performance. The findings of the transport-oriented health efficiency assessment reveal that the economies were unable to perform well in the last year of the research period owing to the nationwide lockdowns. Nonetheless, they demonstrated efficiency in the first half of the research period. The joint assessment of economy- and transport-oriented health efficiency indicates that economic and transport input resources can adversely affect the GDP and life expectancy simultaneously, and the medical infrastructure, pharmaceutical expenditure, and number of medical graduates serve as constructive stimuli for health efficiency improvement.

Exosomal Non-coding RNA Derived from Mesenchymal Stem Cells (MSCs) in Autoimmune Diseases Progression and Therapy; an Updated Review

Inflammation and autoimmune diseases (AD) are common outcomes of an overactive immune system. Inflammation occurs due to the immune system reacting to damaging stimuli. Exosomes are being recognized as an advanced therapeutic approach for addressing an overactive immune system, positioning them as a promising option for treating AD. Mesenchymal stem cells (MSCs) release exosomes that have strong immunomodulatory effects, influenced by their cell of origin. MSCs-exosomes, being a cell-free therapy, exhibit less toxicity and provoke a diminished immune response compared to cell-based therapies. Exosomal non-coding RNAs (ncRNA), particularly microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are intricately linked to various biological and functional aspects of human health. Exosomal ncRNAs can lead to tissue malfunction, aging, and illnesses when they experience tissue-specific alterations as a result of various internal or external problems. In this study, we will examine current trends in exosomal ncRNA researches regarding AD. Then, therapeutic uses of MSCs-exosomal ncRNA will be outlined, with a particle focus on the underlying molecular mechanisms.

OTULIN of exosomes derived from Schwann cells promotes peripheral nerve injury repair by regulating macrophage polarization via deubiquitination of ERBB2

A significant public health burden is peripheral nerve damage (PNI), which is frequently brought on by trauma. Macrophages were essential to the effective regeneration of nerves and restoration of function. It is still not entirely understood how macrophages and Schwann cells interact after damage during remyelination. Here, we established an inflammatory model in bone marrow-derived macrophages (BMDMs) and a rat sciatic nerve damage model to investigate the possible relationship between lipopolysaccharides (LPS)-induced exosomes derived from Schwann cells (LPS SCs-Exos) and peripheral nerve repair. The pro-inflammatory macrophage was changed into a pro-regeneration macrophage by LPS SC-Exos. Notably, it was discovered that SC-Exos had a substantial enrichment of OTULIN. OTULIN was a key mediator in the regulatory effects of LPS SC-Exos by deubiquitinating ERBB2 and preventing its degradation. The local injection of SC-Exos into the nerve damage site led in a faster functional recovery, axon regeneration and remyelination, and an increased M2 macrophage polarization, whereas OTULIN knockdown reversed these effects in vivo. Our results indicate that LPS SC-Exos may offer a therapeutic avenue for peripheral nerve regeneration by promoting macrophage polarization toward an M2 phenotype through the shuttling of OTULIN and deubiquitination of ERBB2. SIGNIFICANCE STATEMENT: OTULIN protein from SC-Exos mediated the macrophages polarization and axonal growth in BMDMs through promoting ubiquitination of ERBB2 and triggering the degradation of ERBB2. The findings offered prospective therapeutic hints for PNI therapy approaches that target axonal regrowth.

The Combined Anti-Aging Effect of Hydrolyzed Collagen Oligopeptides and Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells on Human Skin Fibroblasts

Stem cell-derived exosomes (SC-Exos) are used as a source of regenerative medicine, but certain limitations hinder their uses. The effect of hydrolyzed collagen oligopeptides (HCOPs), a functional ingredient of SC-Exos is not widely known to the general public. We herein evaluated the combined anti-aging effects of HCOPs and exosomes derived from human umbilical cord mesenchymal stem cells (HucMSC-Exos) using a senescence model established on human skin fibroblasts (HSFs). This study discovered that cells treated with HucMSC-Exos + HCOPs enhanced their proliferative and migratory capabilities; reduced both reactive oxygen species production and senescence-associated β-galactosidase activity; augmented type I and type III collagen expression; attenuated the expression of matrix-degrading metalloproteinases (MMP-1, MMP-3, and MMP-9), interleukin 1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α); and decreased the expression of p16, p21, and p53 as compared with the cells treated with HucMSC-Exos or HCOPs alone. These results suggest a possible strategy for enhancing the skin anti-aging ability of HucMSC-Exos with HCOPs.

Recent Advances in Nanomaterials for the Treatment of Acute Kidney Injury

Acute kidney injury (AKI) is a serious clinical syndrome with high morbidity, elevated mortality, and poor prognosis, commonly considered a "sword of Damocles" for hospitalized patients, especially those in intensive care units. Oxidative stress, inflammation, and apoptosis, caused by the excessive production of reactive oxygen species (ROS), play a key role in AKI progression. Hence, the investigation of effective and safe antioxidants and inflammatory regulators to scavenge overexpressed ROS and regulate excessive inflammation has become a promising therapeutic option. However, the unique physiological structure and complex pathological alterations in the kidneys render traditional therapies ineffective, impeding the residence and efficacy of most antioxidant and anti-inflammatory small molecule drugs within the renal milieu. Recently, nanotherapeutic interventions have emerged as a promising and prospective strategy for AKI, overcoming traditional treatment dilemmas through alterations in size, shape, charge, and surface modifications. This Review succinctly summarizes the latest advancements in nanotherapeutic approaches for AKI, encompassing nanozymes, ROS scavenger nanomaterials, MSC-EVs, and nanomaterials loaded with antioxidants and inflammatory regulator. Following this, strategies aimed at enhancing biocompatibility and kidney targeting are introduced. Furthermore, a brief discussion on the current challenges and future prospects in this research field is presented, providing a comprehensive overview of the evolving landscape of nanotherapeutic interventions for AKI.

A state-of-the-art review of the recent advances in exosome isolation and detection methods in viral infection

Proteins, RNA, DNA, lipids, and carbohydrates are only some of the molecular components found in exosomes released by tumor cells. They play an essential role in healthy and diseased cells as messengers of short- and long-distance intercellular communication. However, since exosomes are released by every kind of cell and may be found in blood and other bodily fluids, they may one day serve as biomarkers for a wide range of disorders. In many pathological conditions, including cancer, inflammation, and infection, they play a role. It has been shown that the biogenesis of exosomes is analogous to that of viruses and that the exosomal cargo plays an essential role in the propagation, dissemination, and infection of several viruses. Bidirectional modulation of the immune response is achieved by the ability of exosomes associated with viruses to facilitate immunological escape and stimulate the body's antiviral immune response. Recently, exosomes have received a lot of interest due to their potential therapeutic use as biomarkers for viral infections such as human immunodeficiency virus (HIV), Hepatitis B virus (HBV), Hepatitis C virus (HCV), Epstein-Barr virus (EBV), and SARS-CoV-2. This article discusses the purification procedures and detection techniques for exosomes and examines the research on exosomes as a biomarker of viral infection.

Astragaloside IV (ASIV) Mediates Endothelial Progenitor Cell (EPC) Exosomal LINC01963 to Inhibit Pyroptosis and Oxidative Stress in High Glucose-impaired Endothelial Cells

BACKGROUND

Hyperglycemia is widespread in the world's population, increasing the risk of many diseases. This study aimed to explore the regulatory effect and mechanism of astragaloside IV (ASIV)-mediated endothelial progenitor cells (EPCs) exosomal LINC01963 in endothelial cells (HUVECs) impaired by high glucose.

METHODS

Morphologies of exosomes were observed by light microscope and electron microscope. Immunofluorescence was used to identify EPCs and detect the expressions of caspase-1. LINC01963 was detected by quantitative reverse transcription PCR. NLRP3, ASC, and caspase-3 were detected by Western Blot. Nanoparticle tracking analysis was carried out to analyze the exosome diameter. High-throughput sequencing was applied to screen target lncRNAs. The proliferation of endothelial cells was measured by cell counting kit-8 assay. The apoptosis level of HUVECs was detected by flow cytometry and TdT-mediated dUTP Nick-End labeling. The levels of IL- 1β, IL-18, ROS, SOD, MDA, and LDH were measured by enzyme-linked immunosorbent assay.

RESULTS

ASIV could promote the secretion of the EPC exosome. LINC01963 was obtained by high-throughput sequencing. It was observed that high glucose could inhibit the proliferation, reduce the level of SOD, the expression of NLRP3, ASC, and caspase- 1, increase the levels of IL-1β, IL-18, ROS, MDA, and LDH, and promote apoptosis of HUVECs. Whereas LINC01963 could inhibit the apoptosis of HUVECs, the increase the expression of NLRP3, ASC, and caspase-1, and decrease the levels of IL-1β, IL-18, ROS, MDA, and LDH.

CONCLUSION

EPCs exosomal LINC01963 play an inhibitory role in high glucoseinduced pyroptosis and oxidative stress of HUVECs. This study provides new ideas and directions for treating hyperglycemia and researching exosomal lncRNAs.

H19: An Oncogenic Long Non-coding RNA in Colorectal Cancer

Colorectal cancer (CRC) has been recorded amongst the most common cancers in the world, with high morbidity and mortality rates, and relatively low survival rates. With risk factors such as chronic illness, age, and lifestyle associated with the development of CRC, the incidence of CRC is increasing each year. Thus, the discovery of novel biomarkers to improve the diagnosis and prognosis of CRC has become beneficial. Long non-coding RNAs (lncRNAs) have been emerging as potential players in several tumor types, one among them is the lncRNA H19. The paternally imprinted oncofetal gene is expressed in the embryo, downregulated at birth, and reappears in tumors. H19 aids in CRC cell growth, proliferation, invasion, and metastasis via various mechanisms of action, significantly through the lncRNA-microRNA (miRNA)-messenger RNA (mRNA)-competitive endogenous RNA (ceRNA) network, where H19 behaves as a miRNA sponge. The RNA transcript of H19 obtained from the first exon of the H19 gene, miRNA-675 also promotes CRC carcinogenesis. Overexpression of H19 in malignant tissues compared to adjacent non-malignant tissues marks H19 as an independent prognostic marker in CRC. Besides its prognostic value, H19 serves as a promising target for therapy in CRC treatment.

Bone marrow mesenchymal stem cell‑derived exosomes: A novel therapeutic agent for tendon‑bone healing (Review)

In sports medicine, injuries related to the insertion of tendons into bones, including rotator cuff injuries, anterior cruciate ligament injuries and Achilles tendon ruptures, are commonly observed. However, traditional therapies have proven to be insufficient in achieving satisfactory outcomes due to the intricate anatomical structure associated with these injuries. Adult bone marrow mesenchymal stem cells possess self‑renewal and multi‑directional differentiation potential and can generate various mesenchymal tissues to aid in the recovery of bone, cartilage, adipose tissue and bone marrow hematopoietic tissue. In addition, extracellular vesicles derived from bone marrow mesenchymal stem cells known as exosomes, contain lipids, proteins and nucleic acids that govern the tissue microenvironment, facilitate tissue repair and perform various biological functions. Studies have demonstrated that bone marrow mesenchymal stem cell‑derived exosomes can function as natural nanocapsules for drug delivery and can enhance tendon‑bone healing strength. The present review discusses the latest research results on the role of exosomes released by bone marrow mesenchymal stem cells in tendon‑bone healing and provides valuable information for implementing these techniques in regenerative medicine and sports health.

Exosomes: Potential Next-Generation Nanocarriers for the Therapy of Inflammatory Diseases

Inflammatory diseases are common pathological processes caused by various acute and chronic factors, and some of them are autoimmune diseases. Exosomes are fundamental extracellular vesicles secreted by almost all cells, which contain a series of constituents, i.e., cytoskeletal and cytosolic proteins (actin, tubulin, and histones), nucleic acids (mRNA, miRNA, and DNA), lipids (diacylglycerophosphates, cholesterol, sphingomyelin, and ceramide), and other bioactive components (cytokines, signal transduction proteins, enzymes, antigen presentation and membrane transport/fusion molecules, and adhesion molecules). This review will be a synopsis of the knowledge on the contribution of exosomes from different cell sources as possible therapeutic agents against inflammation, focusing on several inflammatory diseases, neurological diseases, rheumatoid arthritis and osteoarthritis, intestinal bowel disease, asthma, and liver and kidney injuries. Current knowledge indicates that the role of exosomes in the therapy of inflammation and in inflammatory diseases could be distinctive. The main limitations to their clinical translation are still production, isolation, and storage. Additionally, there is an urgent need to personalize the treatments in terms of the selection of exosomes; their dosages and routes of administration; and a deeper knowledge about their biodistribution, type and incidence of adverse events, and long-term effects of exosomes. In conclusion, exosomes can be a very promising next-generation therapeutic option, superior to synthetic nanocarriers and cell therapy, and can represent a new strategy of effective, safe, versatile, and selective delivery systems in the future.

Bioengineering extracellular vesicles: smart nanomaterials for bone regeneration

In the past decade, extracellular vesicles (EVs) have emerged as key regulators of bone development, homeostasis and repair. EV-based therapies have the potential to circumnavigate key issues hindering the translation of cell-based therapies including functional tissue engraftment, uncontrolled differentiation and immunogenicity issues. Due to EVs' innate biocompatibility, low immunogenicity, and high physiochemical stability, these naturally-derived nanoparticles have garnered growing interest as potential acellular nanoscale therapeutics for a variety of diseases. Our increasing knowledge of the roles these cell-derived nanoparticles play, has made them an exciting focus in the development of novel pro-regenerative therapies for bone repair. Although these nano-sized vesicles have shown promise, their clinical translation is hindered due to several challenges in the EV supply chain, ultimately impacting therapeutic efficacy and yield. From the biochemical and biophysical stimulation of parental cells to the transition to scalable manufacture or maximising vesicles therapeutic response in vivo, a multitude of techniques have been employed to improve the clinical efficacy of EVs. This review explores state of the art bioengineering strategies to promote the therapeutic utility of vesicles beyond their native capacity, thus maximising the clinical potential of these pro-regenerative nanoscale therapeutics for bone repair.

Extracellular vesicle-loaded hydrogels for tissue repair and regeneration

Extracellular vesicles (EVs) are a collective term for nanoscale or microscale vesicles secreted by cells that play important biological roles. Mesenchymal stem cells are a class of cells with the potential for self-healing and multidirectional differentiation. In recent years, numerous studies have shown that EVs, especially those secreted by mesenchymal stem cells, can promote the repair and regeneration of various tissues and, thus, have significant potential in regenerative medicine. However, due to the rapid clearance capacity of the circulatory system, EVs are barely able to act persistently at specific sites for repair of target tissues. Hydrogels have good biocompatibility and loose and porous structural properties that allow them to serve as EV carriers, thereby prolonging the retention in certain specific areas and slowing the release of EVs. When EVs are needed to function at specific sites, the EV-loaded hydrogels can stand as an excellent approach. In this review, we first introduce the sources, roles, and extraction and characterization methods of EVs and describe their current application status. We then review the different types of hydrogels and discuss factors influencing their abilities to carry and release EVs. We summarize several strategies for loading EVs into hydrogels and characterizing EV-loaded hydrogels. Furthermore, we discuss application strategies for EV-loaded hydrogels and review their specific applications in tissue regeneration and repair. This article concludes with a summary of the current state of research on EV-loaded hydrogels and an outlook on future research directions, which we hope will provide promising ideas for researchers.

Therapeutic potential and mechanisms of mesenchymal stem cell-derived exosomes as bioactive materials in tendon-bone healing

Tendon-bone insertion (TBI) injuries, such as anterior cruciate ligament injury and rotator cuff injury, are the most common soft tissue injuries. In most situations, surgical tendon/ligament reconstruction is necessary for treating such injuries. However, a significant number of cases failed because healing of the enthesis occurs through scar tissue formation rather than the regeneration of transitional tissue. In recent years, the therapeutic potential of mesenchymal stem cells (MSCs) has been well documented in animal and clinical studies, such as chronic paraplegia, non-ischemic heart failure, and osteoarthritis of the knee. MSCs are multipotent stem cells, which have self-renewability and the ability to differentiate into a wide variety of cells such as chondrocytes, osteoblasts, and adipocytes. Numerous studies have suggested that MSCs could promote angiogenesis and cell proliferation, reduce inflammation, and produce a large number of bioactive molecules involved in the repair. These effects are likely mediated by the paracrine mechanisms of MSCs, particularly through the release of exosomes. Exosomes, nano-sized extracellular vesicles (EVs) with a lipid bilayer and a membrane structure, are naturally released by various cell types. They play an essential role in intercellular communication by transferring bioactive lipids, proteins, and nucleic acids, such as mRNAs and miRNAs, between cells to influence the physiological and pathological processes of recipient cells. Exosomes have been shown to facilitate tissue repair and regeneration. Herein, we discuss the prospective applications of MSC-derived exosomes in TBI injuries. We also review the roles of MSC-EVs and the underlying mechanisms of their effects on promoting tendon-bone healing. At last, we discuss the present challenges and future research directions.

Small extracellular vesicles from mesenchymal stem cells: A potential Weapon for chronic non-healing wound treatment

Chronic non-healing wounds have posed a severe threat to patients mentally and physically. Behavior dysregulation of remaining cells at wound sites is recognized as the chief culprit to destroy healing process and hinders wound healing. Therefore, regulating and restoring normal cellular behavior is the core of chronic non-healing wound treatment. In recent years, the therapy with mesenchymal stem cells (MSCs) has become a promising option for chronic wound healing and the efficacy has increasingly been attributed to their exocrine functions. Small extracellular vesicles derived from MSCs (MSC-sEVs) are reported to benefit almost all stages of wound healing by regulating the cellular behavior to participate in the process of inflammatory response, angiogenesis, re-epithelization, and scarless healing. Here, we describe the characteristics of MSC-sEVs and discuss their therapeutic potential in chronic wound treatment. Additionally, we also provide an overview of the application avenues of MSC-sEVs in wound treatment. Finally, we summarize strategies for large-scale production and engineering of MSC-sEVs. This review may possibly provide meaningful guidance for chronic wound treatment with MSC-sEVs.

Mesenchymal Stem Cell-derived Exosomes Affect Macrophage Phenotype: A Cell-free Strategy for the Treatment of Skeletal Muscle Disorders

The process of tissue damage, repair, and regeneration in the skeletal muscle system involves complex inflammatory processes. Factors released in the inflammatory microenvironment can affect the phenotypic changes of macrophages, thereby changing the inflammatory process, making macrophages an important target for tissue repair treatment. Mesenchymal stem cells exert anti-inflammatory effects by regulating immune cells. In particular, exosomes secreted by mesenchymal stem cells have become a new cell-free treatment strategy due to their low tumorigenicity and immunogenicity. This article focuses on the mechanism of the effect of exosomes derived from mesenchymal stem cells on the phenotype of macrophages after skeletal muscle system injury and explores the possible mechanism of macrophages as potential therapeutic targets after tissue injury.

Advances in microRNA from adipose-derived mesenchymal stem cell-derived exosome: focusing on wound healing

Skin wounds are a common condition causing economic burden and they represent an urgent clinical need, especially chronic wounds. Numerous studies have been conducted on the applications of stem cell therapy in wound healing, with adipose-derived mesenchymal stem cells (ADMSCs) playing a major role since they can be isolated easily, yielding a high number of cells, the less invasive harvesting required, the longer life span and no ethical issues. However, the lack of standardized doses and protocols, the heterogeneity of clinical trials, as well as the incompatibility of the immune system limit its application. Recent studies have demonstrated that specific stem cell functions depend on paracrine factors, including extracellular vesicles, in which microRNAs in exosomes (Exo-miRNAs) are essential in controlling their functions. This paper describes the application and mechanism whereby ADMSC-Exo-miRNA regulates wound healing. ADMSC-Exo-miRNA is involved in various stages in wounds, including modulating the immune response and inflammation, accelerating skin cell proliferation and epithelialization, promoting vascular repair, and regulating collagen remodeling thereby reducing scar formation. In summary, this acellular therapy based on ADMSC-Exo-miRNA has considerable clinical potential, and provides reference values for developing new treatment strategies for wound healing.

Dual Role of Extracellular Vesicles in Sepsis-Associated Kidney and Lung Injury

Extracellular vesicles form a complex intercellular communication network, shuttling a variety of proteins, lipids, and nucleic acids, including regulatory RNAs, such as microRNAs. Transfer of these molecules to target cells allows for the modulation of sets of genes and mediates multiple paracrine and endocrine actions. EVs exert broad pro-inflammatory, pro-oxidant, and pro-apoptotic effects in sepsis, mediating microvascular dysfunction and multiple organ damage. This deleterious role is well documented in sepsis-associated acute kidney injury and acute respiratory distress syndrome. On the other hand, protective effects of stem cell-derived extracellular vesicles have been reported in experimental models of sepsis. Stem cell-derived extracellular vesicles recapitulate beneficial cytoprotective, regenerative, and immunomodulatory properties of parental cells and have shown therapeutic effects in experimental models of sepsis with kidney and lung involvement. Extracellular vesicles are also likely to play a role in deranged kidney-lung crosstalk, a hallmark of sepsis, and may be key to a better understanding of shared mechanisms underlying multiple organ dysfunction. In this review, we analyze the state-of-the-art knowledge on the dual role of EVs in sepsis-associated kidney/lung injury and repair. PubMed library was searched from inception to July 2022, using a combination of medical subject headings (MeSH) and keywords related to EVs, sepsis, acute kidney injury (AKI), acute lung injury (ALI), and acute respiratory distress syndrome (ARDS). Key findings are summarized into two sections on detrimental and beneficial mechanisms of actions of EVs in kidney and lung injury, respectively. The role of EVs in kidney-lung crosstalk is then outlined. Efforts to expand knowledge on EVs may pave the way to employ them as prognostic biomarkers or therapeutic targets to prevent or reduce organ damage in sepsis.

Comparative proteomic profiling of Small Extracellular vesicles derived from iPSCs and tissue specific mesenchymal stem cells

BACKGROUND

Small Extracellular vesicles (EV) are emerging as crucial intercellular messengers that contribute to the physiological processes. EVs contain numerous functional proteins and nucleic acids derived from their parent cells and have different roles depending on their origin. Functionally, EVs transfer these biological materials from the parent cell to the recipient and thus exhibits a novel therapeutic platform for delivering therapeutics molecules to the target tissue. In this regard, EVs derived from stem cells such as Mesenchymal Stem Cells and iPSCs have demonstrated a higher ability to benefit regenerative medicine. Even though these stem cells share some common properties, due to the differences in their origin (cell sources, the hierarchy of potency, etc) the EVs cargo profiling and functionality may vary.

METHOD

We used iTRAQ-based proteomic analysis to conduct a comprehensive and quantitative evaluation of EVs derived from iPSCs and various tissue-specific MSCs in this study. Additionally, the data was analyzed using a variety of bioinformatic tools, including ProteinPilot for peptide and protein identification and quantification; Funrich, GO, Reactome, and KEGG (Kyoto Encyclopedia of Genes and Genomes) for pathway enrichment; the STRING database, and the inBio Discover tool for identifying known and predicted Protein-Protein networks.

RESULTS

Bioinformatics analysis revealed 223 differentially expressed proteins in these EVs; however, Wharton's jelly MSC-EV contained more exclusive proteins with higher protein expression levels. Additionally, 113 proteins were abundant in MSC-EVs, while others were shared between MSC-EVs and iPSC-EVs. Further, based on an in-depth examination of the proteins, their associated pathways, and their interactions with other proteins, it was determined that these proteins are involved in bone regeneration (9.3%), wound healing (4.4%), immune regulation (8.9%), cardiac regeneration (6.6%), neuro regeneration (8.9%), and hepatic regeneration (3.5%).

CONCLUSION

Overall, the results of our proteomic analysis indicate that EVs derived from MSCs have a more robust profile of proteins with higher expression levels than iPSCs. This is a significant finding, as it demonstrates the critical therapeutic role of EVs in a variety of diseases, as demonstrated by enrichment analysis, their versatility, and broad application potential.

Exosomes from LPS-preconditioned bone marrow MSCs accelerated peripheral nerve regeneration via M2 macrophage polarization: Involvement of TSG-6/NF-κB/NLRP3 signaling pathway

Lipopolysaccharide (LPS)-preconditioned mesenchymal stem cells (MSCs) possessed strong immunomodulatory and anti-inflammatory functions by secreting exosomes as major paracrine effectors. However, the specific effect of exosomes from LPS pre-MSCs (LPS pre-Exos) on peripheral nerve regeneration has yet to be documented. Here, we established a sciatic nerve injury model in rats and an inflammatory model in RAW264.7 cells to explore the potential mechanism between LPS pre-Exos and peripheral nerve repair. The local injection of LPS pre-Exos into the nerve injury site resulted in an accelerated functional recovery, axon regeneration and remyelination, and an enhanced M2 Macrophage polarization. Consistent with the data in vivo, LPS pre-Exos were able to shift the pro-inflammation macrophage into a pro-regeneration macrophage. Notably, TNF stimulated gene-6 (TSG-6) was found to be highly enriched in LPS pre-Exos. We obtained si TSG-6 Exo by the knockdown of TSG-6 in LPS pre-Exos to demonstrate the role of TSG-6 in macrophage polarization, and found that TSG-6 served as a critical mediator in LPS pre-Exos-induced regulatory effects through the inhibition of NF-ΚΒ and NOD-like receptor protein 3 (NLRP3). In conclusion, our findings suggested that LPS pre-Exos promoted macrophage polarization toward an M2 phenotype by shuttling TSG-6 to inactivate the NF-ΚΒ/NLRP3 signaling axis, and could provide a potential therapeutic avenue for peripheral nerve repair.

Mesenchymal Stem Cell-Derived Exosomes: Toward Cell-Free Therapeutic Strategies in Chronic Kidney Disease

Chronic kidney disease (CKD) is rising in global prevalence and has become a worldwide public health problem, with adverse outcomes of kidney failure, cardiovascular disease, and premature death. However, current treatments are limited to slowing rather than reversing disease progression or restoring functional nephrons. Hence, innovative strategies aimed at kidney tissue recovery hold promise for CKD therapy. Mesenchymal stem cells (MSCs) are commonly used for regenerative therapy due to their potential for proliferation, differentiation, and immunomodulation. Accumulating evidence suggests that the therapeutic effects of MSCs are largely mediated by paracrine secretion of extracellular vesicles (EVs), predominantly exosomes. MSC-derived exosomes (MSC-Exos) replicate the functions of their originator MSCs via delivery of various genetic and protein cargos to target cells. More recently, MSC-Exos have also been utilized as natural carriers for targeted drug delivery. Therapeutics can be effectively incorporated into exosomes and then delivered to diseased tissue. Thus, MSC-Exos have emerged as a promising cell-free therapy in CKD. In this paper, we describe the characteristics of MSC-Exos and summarize their therapeutic efficacy in preclinical animal models of CKD. We also discuss the potential challenges and strategies in the use of MSC-Exos-based therapies for CKD in the future.

Stem Cell-Derived Extracellular Vesicles as Potential Therapeutic Approach for Acute Kidney Injury

Acute kidney injury is a frequent complication of hospitalized patients and significantly increases morbidity and mortality, worsening costs and length of hospital stay. Despite this impact on healthcare system, treatment still remains only supportive (dialysis). Stem cell-derived extracellular vesicles are a promising option as they recapitulate stem cells properties, overcoming safety issues related to risks or rejection or aberrant differentiation. A growing body of evidence based on pre-clinical studies suggests that extracellular vesicles may be effective to treat acute kidney injury and to limit fibrosis through direct interference with pathogenic mechanisms of vascular and tubular epithelial cell damage. We herein analyze the state-of-the-art knowledge of therapeutic approaches with stem cell-derived extracellular vesicles for different forms of acute kidney injury (toxic, ischemic or septic) dissecting their cytoprotective, regenerative and immunomodulatory properties. We also analyze the potential impact of extracellular vesicles on the mechanisms of transition from acute kidney injury to chronic kidney disease, with a focus on the pivotal role of the inhibition of complement cascade in this setting. Despite some technical limits, nowadays the development of therapies based on stem cell-derived extracellular vesicles holds promise as a new frontier to limit acute kidney injury onset and progression.

Noncoding RNA in Extracellular Vesicles Regulate Differentiation of Mesenchymal Stem Cells

To achieve the desired outcome in tissue engineering regeneration, mesenchymal stem cells need to undergo a series of biological processes, including differentiating into the ideal target cells. The extracellular vesicle (EV) in the microenvironment contributes toward determining the fate of the cells with epigenetic regulation, particularly from noncoding RNA (ncRNA), and exerts transportation and protective effects on ncRNAs. We focused on the components and functions of ncRNA (particularly microRNA) in the EVs. The EVs modified by the ncRNA favor tissue regeneration and pose a potential challenge.

Therapeutic effects of mesenchymal stem cells-derived extracellular vesicles' miRNAs on retinal regeneration: a review

Extracellular vesicles (EVs), which consist of microvesicles and exosomes, are secreted from all cells to transform vital information in the form of lipids, proteins, mRNAs and small RNAs such as microRNAs (miRNAs). Many studies demonstrated that EVs' miRNAs have effects on target cells. Numerous people suffer from the blindness caused by retinal degenerations. The death of retinal neurons is irreversible and creates permanent damage to the retina. In the absence of acceptable cures for retinal degenerative diseases, stem cells and their paracrine agents including EVs have become a promising therapeutic approach. Several studies showed that the therapeutic effects of stem cells are due to the miRNAs of their EVs. Considering the effects of microRNAs in retinal cells development and function and studies which provide the possible roles of mesenchymal stem cells-derived EVs miRNA content on retinal diseases, we focused on the similarities between these two groups of miRNAs that could be helpful for promoting new therapeutic techniques for retinal degenerative diseases.

Immunomodulatory Effect of MSCs and MSCs-Derived Extracellular Vesicles in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a common autoimmune connective tissue disease with unclear etiology and pathogenesis. Mesenchymal stem cell (MSC) and MSC derived extracellular vesicles (EVs) play important roles in regulating innate and adaptive immunity, which are involved in many physiological and pathological processes and contribute to the immune homeostasis in SLE. The effects of MSCs and EVs on SLE have been drawing more and more attention during the past few years. This article reviews the immunomodulatory effects and underlying mechanisms of MSC/MSC-EVs in SLE, which provides novel insight into understanding SLE pathogenesis and guiding the biological therapy.

The Immunomodulatory Properties of Mesenchymal Stem Cells Play a Critical Role in Inducing Immune Tolerance after Liver Transplantation

Although liver transplantation is considered to be the best choice for patients with end-stage liver diseases, postoperative immune rejection still cannot be overlooked. Patients with liver transplantation have to take immunosuppressive drugs for a long time or even their entire lives, in which heavy economic burden and side effects caused by the drugs have become the major impediment for liver transplantation. There is a growing body of evidences indicating that mesenchymal stem cell (MSC) transplantation, a promising tool in regenerative medicine, can be used as an effective way to induce immune tolerance after liver transplantation based on their huge expansion potential and unique immunomodulatory properties. MSCs have been reported to inhibit innate immunity and adaptive immunity to induce a tolerogenic microenvironment. In in vitro studies, transplanted MSCs show plasticity in immune regulation by altering their viability, migration, differentiation, and secretion in the interactions with the surrounding host microenvironment. In this review, we aim to provide an overview of the current understanding of immunomodulatory properties of MSCs in liver transplantation, to elucidate the potential mechanisms behind MSCs regulating immune response, especially in vivo and the influence of the microenvironment, and ultimately to discuss the feasible strategies to improve the clinical prognosis of liver transplantation. Only after exhaustive understanding of potential mechanisms of the MSC immunomodulation can we improve the safety and effectiveness of MSC treatment and achieve better therapeutic effects.

Comparing the Therapeutic Potential of Stem Cells and their Secretory Products in Regenerative Medicine

Cell therapy involves the transplantation of human cells to replace or repair the damaged tissues and modulate the mechanisms underlying disease initiation and progression in the body. Nowadays, many different types of cell-based therapy are developed and used to treat a variety of diseases. In the past decade, cell-free therapy has emerged as a novel approach in regenerative medicine after the discovery that the transplanted cells exerted their therapeutic effect mainly through the secretion of paracrine factors. More and more evidence showed that stem cell-derived secretome, i.e., growth factors, cytokines, and extracellular vesicles, can repair the injured tissues as effectively as the cells. This finding has spurred a new idea to employ secretome in regenerative medicine. Despite that, will cell-free therapy slowly replace cell therapy in the future? Or are these two modes of treatment still needed to address different diseases and conditions? This review provides an indepth discussion about the values of stem cells and secretome in regenerative medicine. In addition, the safety, efficacy, advantages, and disadvantages of using these two modes of treatment in regenerative medicine are also critically reviewed.

Mesenchymal Stem Cell-Derived Extracellular Vesicles to the Rescue of Renal Injury

Acute kidney injury (AKI) and chronic kidney disease (CKD) are rising in global prevalence and cause significant morbidity for patients. Current treatments are limited to slowing instead of stabilising or reversing disease progression. In this review, we describe mesenchymal stem cells (MSCs) and their constituents, extracellular vesicles (EVs) as being a novel therapeutic for CKD. MSC-derived EVs (MSC-EVs) are membrane-enclosed particles, including exosomes, which carry genetic information that mimics the phenotype of their cell of origin. MSC-EVs deliver their cargo of mRNA, miRNA, cytokines, and growth factors to target cells as a form of paracrine communication. This genetically reprograms pathophysiological pathways, which are upregulated in renal failure. Since the method of exosome preparation significantly affects the quality and function of MSC-exosomes, this review compares the methodologies for isolating exosomes from MSCs and their role in tissue regeneration. More specifically, it summarises the therapeutic efficacy of MSC-EVs in 60 preclinical animal models of AKI and CKD and the cargo of biomolecules they deliver. MSC-EVs promote tubular proliferation and angiogenesis, and inhibit apoptosis, oxidative stress, inflammation, the epithelial-to-mesenchymal transition, and fibrosis, to alleviate AKI and CKD. By reprogramming these pathophysiological pathways, MSC-EVs can slow or even reverse the progression of AKI to CKD, and therefore offer potential to transform clinical practice.

Adipose-Derived Stem Cells Secretome and Its Potential Application in "Stem Cell-Free Therapy"

Adipose-derived stem cells (ASCs) secrete many cytokines, proteins, growth factors, and extracellular vesicles with beneficial outcomes that can be used in regenerative medicine. It has great potential, and the development of new treatment strategies using the ASCs secretome is of global interest. Besides cytokines, proteins, and growth factors, the therapeutic effect of secretome is hidden in non-coding RNAs such as miR-21, miR-24, and miR-26 carried via exosomes secreted by adequate cells. The whole secretome, including ASC-derived exosomes (ASC-exos) has been proven in many studies to have immunomodulatory, proangiogenic, neurotrophic, and epithelization activity and can potentially be used for neurodegenerative, cardiovascular, respiratory, inflammatory, and autoimmune diseases as well as wound healing treatment. Due to limitations in the use of stem cells in cell-based therapy, its secretome with emphasis on exosomes seems to be a reasonable and safer alternative with increased effectiveness and fewer side effects. Moreover, the great advantage of cell-free therapy is the possibility of biobanking the ASCs secretome. In this review, we focus on the current state of knowledge on the use of the ASCs secretome in stem cell-free therapy.

Extracellular Vesicles of Mesenchymal Stem Cells: Therapeutic Properties Discovered with Extraordinary Success

Mesenchymal stem cells (MSCs), the cells distributed in the stromas of the body, are known for various properties including replication, the potential of various differentiations, the immune-related processes including inflammation. About two decades ago, these cells were shown to play relevant roles in the therapy of numerous diseases, dependent on their immune regulation and their release of cytokines and growth factors, with ensuing activation of favorable enzymes and processes. Such discovery induced great increase of their investigation. Soon thereafter, however, it became clear that therapeutic actions of MSCs are risky, accompanied by serious drawbacks and defects. MSC therapy has been therefore reduced to a few diseases, replaced for the others by their extracellular vesicles, the MSC-EVs. The latter vesicles recapitulate most therapeutic actions of MSCs, with equal or even better efficacies and without the serious drawbacks of the parent cells. In addition, MSC-EVs are characterized by many advantages, among which are their heterogeneities dependent on the stromas of origin, the alleviation of cell aging, the regulation of immune responses and inflammation. Here we illustrate the MSC-EV therapeutic effects, largely mediated by specific miRNAs, covering various diseases and pathological processes occurring in the bones, heart and vessels, kidney, and brain. MSC-EVs operate also on the development of cancers and on COVID-19, where they alleviate the organ lesions induced by the virus. Therapy by MSC-EVs can be improved by combination of their innate potential to engineering processes inducing precise targeting and transfer of drugs. The unique properties of MSC-EVs explain their intense studies, carried out with extraordinary success. Although not yet developed to clinical practice, the perspectives for proximal future are encouraging.

Mesenchymal Stem Cell-Derived Extracellular Vesicles in Tissue Regeneration

Mesenchymal stem cells (MSCs) are multipotent stem cells that have attracted increasing interest in the field of regenerative medicine. Previously, the differentiation ability of MSCs was believed to be primarily responsible for tissue repair. Recent studies have shown that paracrine mechanisms play an important role in this process. MSCs can secrete soluble molecules and extracellular vesicles (EVs), which mediate paracrine communication. EVs contain large amounts of proteins and nucleic acids, such as mRNAs and microRNAs (miRNAs), and can transfer the cargo between cells. The cargoes are similar to those in MSCs and are not susceptible to degradation due to the protection of the EV bimolecular membrane structure. MSC-EVs can mimic the biological characteristics of MSCs, such as differentiation, maturation, and self-renewal. Due to their broad biological functions and their ability to transfer molecules between cells, EVs have been intensively studied by an increasing number of researchers with a focus on therapeutic applications, especially those of EVs secreted by MSCs. In this review, we discuss MSC-derived EVs and their therapeutic potential in tissue regeneration.

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.

Mitigation of Sodium Iodate-Induced Cytotoxicity in Retinal Pigment Epithelial Cells in vitro by Transgenic Erythropoietin-Expressing Mesenchymal Stem Cells

Mesenchymal stem cells (MSC) have shown promise in restoring the vision of patients in clinical trials. However, this therapeutic effect is not observed in every treated patient and is possibly due to the inefficacies of cell delivery and high cell death following transplantation. Utilizing erythropoietin can significantly enhance the regenerative properties of MSCs and hence improve retinal neuron survivability in oxidative stress. Hence, this study aimed to investigate the efficacy of conditioned medium (CM) obtained from transgenic human erythropoietin-expressing MSCs (MSC _EPO ) in protecting human retinal pigment epithelial cells from sodium iodate (NaIO₃)-induced cell death. Human MSC and MSC _EPO were first cultured to obtain conditioned media (CM). The IC₅₀ of NaIO₃ in the ARPE-19 culture was then determined by an MTT assay. After that, the efficacy of both MSC-CM and MSC-CM _EPO in ARPE-19 cell survival were compared at 24 and 48 h after NaIO₃ treatment with MTT. The treatment effects on mitochondrial membrane potential was then measured by a JC-1 flow cytometric assay. The MTT results indicated a corresponding increase in cell survivability (5-58%) in the ARPE-19 cell cultures. In comparison to MSC-CM, the use of conditioned medium collected from the MSC-CM _EPO further enhanced the rate of ARPE-19 survivability at 24 h (P < 0.05) and 48 h (P < 0.05) in the presence of NaIO₃. Furthermore, more than 90% were found viable with the JC-1 assay after MSC-CM _EPO treatment, showing a positive implication on the mitochondrial dynamics of ARPE-19. The MSC-CM _EPO provided an enhanced mitigating effect against NaIO₃-induced ARPE-19 cell death over that of MSC-CM alone during the early phase of the treatment, and it may act as a future therapy in treating retinal degenerative diseases.

Comparative study of commercial protocols for high recovery of high-purity mesenchymal stem cell-derived extracellular vesicle isolation and their efficient labeling with fluorescent dyes

The extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) can be used as carriers for therapeutic molecules and drugs to target disordered tissues. This aimed to compare the protocols used for isolation of MSC-derived EVs by comparing EV collection conditions and three commercial purification kits. We also determined appropriate fluorescent dyes for labeling EVs. MSC-derived EVs were efficiently secreted during cell growth and highly purified by the phosphatidyl serine-based affinity kit. Although the EV membrane was more efficiently labeled with the fluorescent dye PKH67 compared to other probes, the efficiency was not enough to accurately analyze the endothelial cellular uptake of EVs. Results verified the easy protocol for isolating and fluorescently labeling EVs with commercial reagents and kits, but meanwhile, further modification of the protocol is required in order to scale up the amount of EVs derived from MSCs using fluorescent probes.

Mesenchymal Stem Cell Derived Extracellular Vesicles for Repairing the Neurovascular Unit after Ischemic Stroke

Ischemic stroke is a debilitating disease and one of the leading causes of long-term disability. During the early phase after ischemic stroke, the blood-brain barrier (BBB) exhibits increased permeability and disruption, leading to an influx of immune cells and inflammatory molecules that exacerbate the damage to the brain tissue. Mesenchymal stem cells have been investigated as a promising therapy to improve the recovery after ischemic stroke. The therapeutic effects imparted by MSCs are mostly paracrine. Recently, the role of extracellular vesicles released by these MSCs have been studied as possible carriers of information to the brain. This review focuses on the potential of MSC derived EVs to repair the components of the neurovascular unit (NVU) controlling the BBB, in order to promote overall recovery from stroke. Here, we review the techniques for increasing the effectiveness of MSC-based therapeutics, such as improved homing capabilities, bioengineering protein expression, modified culture conditions, and customizing the contents of EVs. Combining multiple techniques targeting NVU repair may provide the basis for improved future stroke treatment paradigms.

Extracellular Vesicles From Perinatal Cells for Anti-inflammatory Therapy

Perinatal cells, including cells from placenta, fetal annexes (amniotic and chorionic membranes), umbilical cord, and amniotic fluid display intrinsic immunological properties which very likely contribute to the development and growth of a semiallogeneic fetus during pregnancy. Many studies have shown that perinatal cells can inhibit the activation and modulate the functions of various inflammatory cells of the innate and adaptive immune systems, including macrophages, neutrophils, natural killer cells, dendritic cells, and T and B lymphocytes. These immunological properties, along with their easy availability and lack of ethical concerns, make perinatal cells very useful/promising in regenerative medicine. In recent years, extracellular vesicles (EVs) have gained great interest as a new therapeutic tool in regenerative medicine being a cell-free product potentially capable, thanks to the growth factors, miRNA and other bioactive molecules they convey, of modulating the inflammatory microenvironment thus favoring tissue regeneration. The immunomodulatory actions of perinatal cells have been suggested to be mediated by still not fully identified factors (secretoma) secreted either as soluble proteins/cytokines or entrapped in EVs. In this review, we will discuss how perinatal derived EVs may contribute toward the modulation of the immune response in various inflammatory pathologies (acute and chronic) by directly targeting different elements of the inflammatory microenvironment, ultimately leading to the repair and regeneration of damaged tissues.

Extracellular Vesicles From Liver Progenitor Cells Downregulates Fibroblast Metabolic Activity and Increase the Expression of Immune-Response Related Molecules

Extracellular vesicles (EVs) mediate cell-to-cell crosstalk whose content can induce changes in acceptor cells and their microenvironment. MLP29 cells are mouse liver progenitor cells that release EVs loaded with signaling cues that could affect cell fate. In the current work, we incubated 3T3-L1 mouse fibroblasts with MLP29-derived EVs, and then analyzed changes by proteomics and transcriptomics. Results showed a general downregulation of protein and transcript expression related to proliferative and metabolic routes dependent on TGF-beta. We also observed an increase in the ERBB2 interacting protein (ERBIN) and Cxcl2, together with an induction of ribosome biogenesis and interferon-related response molecules, suggesting the activation of immune system signaling.

Exosomal LncRNA LINC00659 transferred from cancer-associated fibroblasts promotes colorectal cancer cell progression via miR-342-3p/ANXA2 axis

Background

Cancer-associated fibroblasts (CAFs) play a pivotal role in regulating tumor progression by transferring exosomes to adjacent cells. Our aim was to clarify the role of LINC00659 encapsulated in CAFs-derived exosomes (CAFs-exo) in colorectal cancer (CRC).

Methods

CAFs and normal fibroblasts (NFs) were isolated and cultured. CAFs-exo and NFs-derived exosomes (NFs-exo) were characterized by transmission electron microscope and Western blot. The mRNA level of LINC00659 in CAFs-exo and NFs-exo were measured. Then we analyzed cell proliferation by CCK-8 and clone formation assay, cell migration by cell scratch, and cell invasion by Transwell. Epithelial mesenchymal transformation (EMT) related markers E-cadherin, N-cadherin, Vimentin and Snail-1 expressions were assessed by Western blot. The binding of LINC00659 and miR-342-3p, miR-342-3p and ANXA2 were analyzed by dual-luciferase reporter gene assay.

Results

CAFs and NFs showed a spindle-like morphology. CAFs-exo promoted CRC cell proliferation, migration, invasion and EMT progression. The expression of LINC00659 in CAF-derived exosomes was significantly increased, and fibroblasts could transfer exosomal LINC00659 to CRC cells. We further revealed that transfection of miR-342-3p mimic or sh-ANXA2 could obviously reverse the promotion effect of exosomal LINC00659 on CRC progression. Functional studies reveal that LINC00659 is transferred from CAFs to the cancer cells via exosomes, where it promotes CRC cell proliferation, invasion, migration and EMT progression in vitro. Mechanistically, LINC00659 interacts directly with miR-342-3p to increase ANXA2 expression in CRC cells.

Conclusion

Collected evidence supported that CAFs-derived exosomal LINC00659 promotes CRC cell proliferation, invasion and migration via miR-342-3p/ANXA2axis.

Exosomes: Emerging Diagnostic and Therapeutic Targets in Cutaneous Diseases

Skin is the largest human organ and is continuously exposed to various exogenous and endogenous trigger factors affecting body homeostasis. A number of mechanisms, including genetic, inflammatory and autoimmune ones, have been implicated in the pathogenesis of cutaneous diseases. Recently, there has been considerable interest in the role that extracellular vesicles, particularly exosomes, play in human diseases, through their modulation of multiple signaling pathways. Exosomes are nano-sized vesicles secreted by all cell types. They function as cargo carriers shuttling proteins, nucleic acids, lipids etc., thus impacting the cell-cell communications and transfer of vital information/moieties critical for skin homeostasis and disease pathogenesis. This review summarizes the available knowledge on how exosomes affect pathogenesis of cutaneous diseases, and highlights their potential as future targets for the therapy of various skin diseases.

Urinary vitronectin identifies patients with high levels of fibrosis in kidney grafts

BACKGROUND

In kidney transplantation, fibrosis represents the final and irreversible consequence of the pathogenic mechanisms that lead to graft failure, and in the late stages it irremediably precedes the loss of renal function. The invasiveness of kidney biopsy prevents this condition from being frequently monitored, while clinical data are rather unspecific. The objective of this study was to find noninvasive biomarkers of kidney rejection.

METHODS

We carried out proteomic analysis of the urinary Extracellular Vesicles (uEVs) from a cohort of kidney transplant recipients (n = 23) classified according to their biopsy-based diagnosis and clinical parameters as interstitial fibrosis and tubular atrophy (IFTA), acute cellular rejection (ACR), calcineurin inhibitors toxicity (CNIT) and normal kidney function (NKF).

RESULTS

Shotgun mass spectrometry of uEV-proteins identified differential expression of several proteins among these different groups. Up to 23 of these proteins were re-evaluated using targeted proteomics in a new independent cohort of patients (n = 41) classified in the same diagnostic groups. Among other results, we found a differential expression of vitronectin (VTN) in patients displaying chronic interstitial and tubular lesions (ci and ct mean > 2 according to Banff criteria). These results were further confirmed by a pilot study using enzyme-linked immunosorbent assay (ELISA).

CONCLUSION

Urinary vitronectin levels are a potential stand-alone biomarker to monitor fibrotic changes in kidney transplant recipients in a non-invasive fashion.

Stem Cell-Derived Exosomes and Nanovesicles: Promotion of Cell Proliferation, Migration, and Anti-Senescence for Treatment of Wound Damage and Skin Ageing

Extracellular vesicles (EVs), such as exosomes, are nano-sized vesicles derived from endocytic membranes and contain biomolecules such as proteins, lipids, RNAs, and DNAs for the transfer of signals to recipient cells, playing significant roles in cell-to-cell communication. Discovery of exosomes has attracted attention for possible use as next generation therapies in clinical applications; however, several studies suggest that cells secrete exosomes that perform as mediators in the tumor niche and play several roles in tumorigenesis, angiogenesis, and metastasis. Recently, stem cell-derived exosomes have been suggested as a desirable source for regenerative medicine due to their roles in the promotion of angiogenesis via migratory and proliferative mechanisms. This review is aimed at demonstrating the present knowledge of stem cell-derived exosomes and cell-engineered nanovesicles (CNVs) as proliferative, migratory, and anti-senescent therapeutic biomaterial for use in tissue regeneration; wound healing and anti-ageing are explained. We conclude this review by discussing the future perspectives of stem cell-derived exosomes and CNVs as a platform in therapeutic strategies for treatment of wound damage and skin aging.

Cardiovascular Complications Associated with COVID-19 and Potential Therapeutic~Strategies

The outbreak of coronavirus disease 2019 (COVID-19), an infectious disease with severe acute respiratory syndrome, has now become a worldwide pandemic. Despite the respiratory complication, COVID-19 is also associated with significant multiple organ dysfunction, including severe cardiac impairment. Emerging evidence reveals a direct interplay between COVID-19 and dire cardiovascular complications, including myocardial injury, heart failure, heart attack, myocarditis, arrhythmias as well as blood clots, which are accompanied with elevated risk and adverse outcome among infected patients, even sudden death. The proposed pathophysiological mechanisms of myocardial impairment include invasion of SARS-CoV-2 virus via angiotensin-converting enzyme 2 to cardiovascular cells/tissue, which leads to endothelial inflammation and dysfunction, de-stabilization of vulnerable atherosclerotic plaques, stent thrombosis, cardiac stress due to diminish oxygen supply and cardiac muscle damage, and myocardial infarction. Several promising therapeutics are under investigation to the overall prognosis of COVID-19 patients with high risk of cardiovascular impairment, nevertheless to date, none have shown proven clinical efficacy. In this comprehensive review, we aimed to highlight the current integrated therapeutic approaches for COVID-19 and we summarized the potential therapeutic options, currently under clinical trials, with their mechanisms of action and associated adverse cardiac events in highly infectious COVID-19 patients.

Intranasal delivery of mesenchymal stem cell-derived extracellular vesicles exerts immunomodulatory and neuroprotective effects in a 3xTg model of Alzheimer's disease

The critical role of neuroinflammation in favoring and accelerating the pathogenic process in Alzheimer's disease (AD) increased the need to target the cerebral innate immune cells as a potential therapeutic strategy to slow down the disease progression. In this scenario, mesenchymal stem cells (MSCs) have risen considerable interest thanks to their immunomodulatory properties, which have been largely ascribed to the release of extracellular vesicles (EVs), namely exosomes and microvesicles. Indeed, the beneficial effects of MSC-EVs in regulating the inflammatory response have been reported in different AD mouse models, upon chronic intravenous or intracerebroventricular administration. In this study, we use the triple-transgenic 3xTg mice showing for the first time that the intranasal route of administration of EVs, derived from cytokine-preconditioned MSCs, was able to induce immunomodulatory and neuroprotective effects in AD. MSC-EVs reached the brain, where they dampened the activation of microglia cells and increased dendritic spine density. MSC-EVs polarized in vitro murine primary microglia toward an anti-inflammatory phenotype suggesting that the neuroprotective effects observed in transgenic mice could result from a positive modulation of the inflammatory status. The possibility to administer MSC-EVs through a noninvasive route and the demonstration of their anti-inflammatory efficacy might accelerate the chance of a translational exploitation of MSC-EVs in AD.

Extracellular vesicle-carried microRNA-27b derived from mesenchymal stem cells accelerates cutaneous wound healing via E3 ubiquitin ligase ITCH

Mesenchymal stem cells (MSCs) have been highlighted as promising candidate cells in relation to cutaneous wound healing. The current study aimed to investigate whether MSC-derived extracellular vesicles (EVs) could transfer microRNA-27b (miR-27b) to influence cutaneous wound healing. The miR-27b expression was examined in the established cutaneous wound mouse model, and its correlation with the wound healing rate was evaluated by Pearson's correlation analysis. The identified human umbilical cord MSC-derived EVs were co-cultured with human immortal keratinocyte line HaCaT and human skin fibroblasts (HSFs). The mice with cutaneous wound received injections of MSC-derived EVs. The effects of EVs or miR-27b loaded on wound healing and cellular functions were analysed via gain- and loss-of-function approaches in the co-culture system. Dual-luciferase reporter gene assay was employed to verify the relationship between miR-27b and Itchy E3 ubiquitin protein ligase (ITCH). Rescue experiments were conducted to investigate the underlying mechanisms associated with the ITCH/JUNB/inositol-requiring enzyme 1α (IRE1α) axis. miR-27b was down-regulated in the mouse model, with its expression found to be positively correlated with the wound healing rate. Abundant miR-27b was detected in the MSC-derived EVs, while EV-transferred miR-27b improved cutaneous wound healing in mice and improved proliferation and migration of HaCaT cells and HSFs in vitro. As a target of miR-27b, ITCH was found to repress cell proliferation and migration. ITCH enhanced the JUNB ubiquitination and degradation, ultimately inhibiting JUNB and IRE1α expressions and restraining wound healing. Collectively, MSC-derived EVs transferring miR-27b can promote cutaneous wound healing via ITCH/JUNB/IRE1α signalling, providing insight with clinical implications.

The Treatment of Cartilage Damage Using Human Mesenchymal Stem Cell-Derived Extracellular Vesicles: A Systematic Review of in vivo Studies

Damage to joints through injury or disease can result in cartilage loss, which if left untreated can lead to inflammation and ultimately osteoarthritis. There is currently no cure for osteoarthritis and management focusses on symptom control. End-stage osteoarthritis can be debilitating and ultimately requires joint replacement in order to maintain function. Therefore, there is growing interest in innovative therapies for cartilage repair. In this systematic literature review, we sought to explore the in vivo evidence for the use of human Mesenchymal Stem Cell-derived Extracellular Vesicles (MSC-EVs) for treating cartilage damage. We conducted a systematic literature review in accordance with the PRISMA protocol on the evidence for the treatment of cartilage damage using human MSC-EVs. Studies examining in vivo models of cartilage damage were included. A risk of bias analysis of the studies was conducted using the SYRCLE tool. Ten case-control studies were identified in our review, including a total of 159 murine subjects. MSC-EVs were harvested from a variety of human tissues. Five studies induced osteoarthritis, including cartilage loss through surgical joint destabilization, two studies directly created osteochondral lesions and three studies used collagenase to cause cartilage loss. All studies in this review reported reduced cartilage loss following treatment with MSC-EVs, and without significant complications. We conclude that transplantation of MSC-derived EVs into damaged cartilage can effectively reduce cartilage loss in murine models of cartilage injury. Additional randomized studies in animal models that recapitulates human osteoarthritis will be necessary in order to establish findings that inform clinical safety in humans.

Use of Stem Cell Extracellular Vesicles as a "Holistic" Approach to CNS Repair

Neurodegeneration is a hallmark of many diseases and disorders of the central nervous system (CNS). High levels of neuroinflammation are often associated with irreparable damage to CNS cells due to the dysregulation of signaling cascades that are unable to restore a homeostatic balance. Due to the inherent complexity of the CNS, development of CNS-related therapeutics has met limited success. While stem cell therapy has been evaluated in the context of CNS repair, the mechanisms responsible for their functional properties have not been clearly defined. In recent years, there has been growing interest in the use of stem cell extracellular vesicles (EVs) for the treatment of various CNS pathologies as these vesicles are believed to mediate many of the functional effects associated with their donor stem cells. The potency of stem cell EVs is believed to be largely driven by their biological cargo which includes various types of RNAs, proteins, and cytokines. In this review, we describe the characteristic properties of stem cell EVs and summarize their reported neuroprotective and immunomodulatory functions. A special emphasis is placed on the identification of specific biological cargo, including proteins and non-coding RNA molecules, that have been found to be associated with stem cell EVs. Collectively, this review highlights the potential of stem cell EVs as an alternative to traditional stem cell therapy for the repair of cellular damage associated with diverse CNS pathologies.

Can Stem Cells Beat COVID-19: Advancing Stem Cells and Extracellular Vesicles Toward Mainstream Medicine for Lung Injuries Associated With SARS-CoV-2 Infections

A number of medicines are currently under investigation for the treatment of COVID-19 disease including anti-viral, anti-malarial, and anti-inflammatory agents. While these treatments can improve patient's recovery and survival, these therapeutic strategies do not lead to unequivocal restoration of the lung damage inflicted by this disease. Stem cell therapies and, more recently, their secreted extracellular vesicles (EVs), are emerging as new promising treatments, which could attenuate inflammation but also regenerate the lung damage caused by COVID-19. Stem cells exert their immunomodulatory, anti-oxidant, and reparative therapeutic effects likely through their EVs, and therefore, could be beneficial, alone or in combination with other therapeutic agents, in people with COVID-19. In this review article, we outline the mechanisms of cytokine storm and lung damage caused by SARS-CoV-2 virus leading to COVID-19 disease and how mesenchymal stem cells (MSCs) and their secreted EVs can be utilized to tackle this damage by harnessing their regenerative properties, which gives them potential enhanced clinical utility compared to other investigated pharmacological treatments. There are currently 17 clinical trials evaluating the therapeutic potential of MSCs for the treatment of COVID-19, the majority of which are administered intravenously with only one clinical trial testing MSC-derived exosomes via inhalation route. While we wait for the outcomes from these trials to be reported, here we emphasize opportunities and risks associated with these therapies, as well as delineate the major roadblocks to progressing these promising curative therapies toward mainstream treatment for COVID-19.

MicroRNAs-containing extracellular vesicles in bone remodeling: An emerging frontier

Bone remodeling is a complex and constant process, which is maintained by well-regulated communication among various cells. Extracellular vesicles (EVs) are small vesicles, which could provide a protective environment for the transportation of various functional molecules. It has been shown that EVs could dock with distant and/or neighboring target cells, deliver cargoes to these specific cells and alter their fates. MicroRNAs (miRNAs), single-stranded non-coding RNAs with 22-26 nucleotides, could bind to mRNAs and repress the translation or stimulate the degradation of mRNAs. It is reported that EVs could serve as the mail carriers, which could cargo miRNAs to exchange information between different cells and act through a novel way to regulate signaling pathways during bone remodeling. In this review, we summarize the function of EV-miRNAs in the communication among mesenchymal stem cells (MSCs), osteoblasts, osteoclasts, osteocytes, and myoblasts during bone remodeling, as well as the key signaling molecules which are involved in this process. The roles of EV-miRNAs in sending intercellular messages in the microenvironment of bone remodeling could shed new light on the development of tissue engineering, and provide novel diagnostic markers and therapeutic targets of bone-related diseases.

MSC-derived exosomes attenuate cell death through suppressing AIF nucleus translocation and enhance cutaneous wound healing

Background

Skin wounding is very common and may be slow to heal. Increasing evidence shows that exosomes derived from mesenchymal stem cells (MSCs) dramatically enhance skin wound healing in a paracrine manner. However, the mechanism underlying this phenomenon has not yet been elucidated. Thus, the objective of the present study was to identify the signaling pathways and paracrine factors by which MSC-derived exosomes promote de novo skin tissue regeneration in response to wound healing.

Methods

In vitro and in vivo skin wound healing models were created by treating immortalized human keratinocytes (HaCaT) with hydrogen peroxide (H₂O₂) and excising full-thickness mouse skin, respectively. Exosomes were extracted from human umbilical cord Wharton’s jelly MSCs (hucMSC-Ex) by ultracentrifugation of cell culture supernatant.

Results

The hucMSC-Ex treatment significantly increased HaCaT cell proliferation and migration in a time- and dose-dependent manner, suppressed HaCaT apoptosis induced with H₂O₂ by inhibiting nuclear translocation of apoptosis-inducing factor (AIF) and upregulating poly ADP ribose polymerase 1 (PARP-1) and poly (ADP-ribose) (PAR). The animal experiments showed that relative to hucMSCs, hucMSC-Ex attenuated full-thickness skin wounding by enhancing epidermal re-epithelialization and dermal angiogenesis.

Conclusions

These findings indicated that direct administration of hucMSC-Ex may effectively treat cutaneous wounding and could be of great value in clinical settings.