Human mesenchymal stem cells and derived extracellular vesicles induce regulatory dendritic cells in type 1 diabetic patients

The impact of 5-aminosalicylates on the efficacy of mesenchymal stem cell therapy in a murine model of ulcerative colitis

Inflammatory bowel disease (IBD) is distinguished by persistent immune-mediated inflammation of the gastrointestinal tract. Previous experimental investigations have shown encouraging outcomes for the use of mesenchymal stem cell (MSC)-based therapy in the treatment of IBD. However, as a primary medication for IBD patients, there is limited information regarding the potential interaction between 5-aminosalicylates (5-ASA) and MSCs. In this present study, we employed the dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mouse model to examine the influence of a combination of MSCs and 5-ASA on the development of UC. The mice were subjected to weight measurement, DAI scoring, assessment of calprotectin expression, and collection of colons for histological examination. The findings revealed that both 5-ASA and MSCs have demonstrated efficacy in the treatment of UC. However, it is noteworthy that 5-ASA exhibits a quicker onset of action, while MSCs demonstrate more advantageous and enduring therapeutic effects. Additionally, the combination of 5-ASA and MSC treatment shows a less favorable efficacy compared to the MSCs alone group. Moreover, our study conducted in vitro revealed that 5-ASA could promote MSC migration, but it could also inhibit MSC proliferation, induce apoptosis, overexpress inflammatory factors (IL-2, IL-12P70, and TNF-α), and reduce the expression of PD-L1 and PD-L2. Furthermore, a significant decrease in the viability of MSCs within the colon was observed as a result of 5-ASA induction. These findings collectively indicate that the use of 5-ASA has the potential to interfere with the therapeutic efficacy of MSC transplantation for the treatment of IBD.

Cord Blood-Derived Multipotent Stem Cells Ameliorate in Vitro/in Vivo Alloreactive Responses, and This Effect Is Associated with Exosomal Microvesicles in Vitro

Human cord blood derived-multipotent stem cells (CB-SCs) have been found to have immunomodulatory capabilities that can result in inhibition of immune activation. Clinically, when used to interact with apheresed peripheral blood mononuclear cells (PBMCs) before reinfusion, they can counteract inflammation and restore immune balance in patients with autoimmune diseases, including alopecia areata and type 1 diabetes. The present study aimed to explore the potential application of CB-SCs to control donor alloreactive responses involved in allogeneic hematopoietic cell transplantation, which often results in acute graft-versus-host disease (GVHD). Phenotypically, we demonstrated that CB-SCs express CD45, CD11b, and CD9 markers on the cell surface; express Oct3/4, a transcription factor for embryonic stem cells; are negative for CD3, CD14, and CD34 expression; and have low expression of HLA-DR. In an allogeneic mixed lymphocyte culture (MLC) using human CD4 T cell enriched PBMCs and allogeneic myeloid derived dendritic cells, direct coculture with CB-SCs decreased CD4 T cell proliferation and activation, as evidenced by a marked decrease in the expression of the late activation markers CD25 and HLA-DR and a reduction of the PKH26 cell proliferation membrane lipophilic marker. Cytokine profiling of MLC supernatants revealed decreased concentrations of inflammatory proteins, including IFN-γ, IL-17, IL-13, IL-2, IL-6, and MIP1-α, along with marked increases in IL-1RA, IP-10, and MCP-1 concentrations in the presence of CB-SCs. Furthermore, transwell MLC experiments revealed that a soluble component was partially responsible for the immunomodulatory effects of CB-SCs. In this regard, exosomal microvesicles (EVs) positive for CD9, CD63, and CD81 were found in CB-SC-derived, ultrafiltered, and ultracentrifuged culture supernatants. CB-SC-EVs inhibited T cell proliferation in allogeneic MLC, suggesting a potential mode of action in allogeneic responses. Finally, CB-SCs were evaluated for their cellular therapy potential in vivo and found to ameliorate the development of GVHD responses in a xenogeneic human PBMC-induced NSG mouse model. Taken together, our results indicate that CB-SCs can directly and indirectly attenuate alloreactive CD4 T cell activation and proliferation in vitro with a potentially related EV mode of action and may have potential as a cellular therapy to control donor T cell-mediated GVHD responses in vivo.

Extracellular vesicles as tools and targets in therapy for diseases

Extracellular vesicles (EVs) are nano-sized, membranous structures secreted into the extracellular space. They exhibit diverse sizes, contents, and surface markers and are ubiquitously released from cells under normal and pathological conditions. Human serum is a rich source of these EVs, though their isolation from serum proteins and non-EV lipid particles poses challenges. These vesicles transport various cellular components such as proteins, mRNAs, miRNAs, DNA, and lipids across distances, influencing numerous physiological and pathological events, including those within the tumor microenvironment (TME). Their pivotal roles in cellular communication make EVs promising candidates for therapeutic agents, drug delivery systems, and disease biomarkers. Especially in cancer diagnostics, EV detection can pave the way for early identification and offers potential as diagnostic biomarkers. Moreover, various EV subtypes are emerging as targeted drug delivery tools, highlighting their potential clinical significance. The need for non-invasive biomarkers to monitor biological processes for diagnostic and therapeutic purposes remains unfulfilled. Tapping into the unique composition of EVs could unlock advanced diagnostic and therapeutic avenues in the future. In this review, we discuss in detail the roles of EVs across various conditions, including cancers (encompassing head and neck, lung, gastric, breast, and hepatocellular carcinoma), neurodegenerative disorders, diabetes, viral infections, autoimmune and renal diseases, emphasizing the potential advancements in molecular diagnostics and drug delivery.

Current status of stem cell therapy for type 1 diabetes: a critique and a prospective consideration

Over the past decade, there had been progress in the development of cell therapy for insulin-dependent diabetes. Nevertheless, important hurdles that need to be overcome still remain. Protocols for the differentiation of pluripotent stem cells into pancreatic progenitors or fully differentiated β-cells have been developed. The resulting insulin-producing cells can control chemically induced diabetes in rodents and were the subject of several clinical trials. However, these cells are immunogenic and possibly teratogenic for their transplantation, and an immunoisolation device and/or immunosuppression is needed. A growing number of studies have utilized genetic manipulations to produce immune evasive cells. Evidence must be provided that in addition to the expected benefit, gene manipulations should not lead to any unforeseen complications. Mesenchymal stem/stromal cells (MSCs) can provide a viable alternative. MSCs are widely available from many tissues. They can form insulin-producing cells by directed differentiation. Experimentally, evidence has shown that the transplantation of allogenic insulin-producing cells derived from MSCs is associated with a muted allogeneic response that does not interfere with their functionality. This can be explained by the immunomodulatory functions of the MSC subpopulation that did not differentiate into insulin-producing cells. Recently, exosomes derived from naive MSCs have been used in the experimental domain to treat diabetes in rodents with varying degrees of success. Several mechanisms for their beneficial functions were proposed including a reduction in insulin resistance, the promotion of autophagy, and an increase in the T regulatory population. However, euglycemia was not achieved in any of these experiments. We suggest that exosomes derived from β-cells or insulin-producing cells (educated) can provide a better therapeutic effect than those derived from undifferentiated cells.

Exosomes derived from odontogenic stem cells: Its role in the dentin-pulp complex

Odontogenic stem cells originate from cranial neural crest cells and offer unique advantages in the regeneration of dentin-pulp complex. There is increasing evidence that stem cells exert their biological functions mainly through exosome-based paracrine effects. Exosomes contain DNA, RNA, proteins, metabolites, etc., which can play a role in intercellular communication and have similar therapeutic potential to stem cells. In addition, compared with stem cells, exosomes also have the advantages of good biocompatibility, high drug carrying capacity, easy to obtain, and few side effects. Odontogenic stem cell-derived exosomes mainly affect the regeneration of the dentin-pulp complex by regulating processes such as dentintogenesis, angiogenesis, neuroprotection and immunomodulation. This review aimed to describe "cell-free therapies" based on odontogenic stem cell-derived exosomes, which aim to regenerate the dentin-pulp complex.

Bioadhesive Microcarriers Encapsulated with IL-27 High Expressive MSC Extracellular Vesicles for Inflammatory Bowel Disease Treatment

Mesenchymal stem cell (MSC) therapy is a promising candidate for inflammatory bowel disease (IBD) treatment, while overcoming the limitations of naive seeding cells function and realizing efficient intestinal targeting remains a challenge. Here, a bioadhesive microparticle carrying interleukin-27 (IL-27) MSC-derived extracellular vesicles (MSCIL-27 EVs) is developed to treat IBD. The MSCIL-27 EVs prepared through lentivirus-mediated gene transfection technology show ideal anti-inflammatory and damage repair function. By encapsulating MSCIL-27 EVs into dopamine methacrylamide-modified hydrogel, a bioadhesive EVs microcarrier via microfluidic technology is fabricated. The resultant microcarriers exhibit ideal MSCIL-27 EVs sustained release effect and effective wet adhesion property. Furthermore, the therapeutic potential of MSCIL-27 EVs-loaded microcarriers in treating IBD is demonstrated. Through giving IBD rats a rectal administration, it is found that the microcarriers can firmly anchor to the surface of colon, reduce the inflammatory response, and repair the damaged barrier. Therefore, the bioadhesive MSCIL-27 EVs-loaded microcarriers provide a promising strategy for the biomedical application of MSC-derived EVs, and broaden the clinical potential of MSC therapy.

Mesenchymal stromal cells and their small extracellular vesicles in allergic diseases: From immunomodulation to therapy

Mesenchymal stromal cells (MSCs) have long been considered a potential tool for treatment of allergic inflammatory diseases, owing to their immunomodulatory characteristics. In recent decades, the medical utility of MSCs has been evaluated both in vitro and in vivo, providing a foundation for therapeutic applications. However, the existing limitations of MSC therapy indicate the necessity for novel therapies. Notably, small extracellular vesicles (sEV) derived from MSCs have emerged rapidly as candidates instead of their parental cells. The acquisition of abundant and scalable MSC-sEV is an obstacle for clinical applications. The potential application of MSC-sEV in allergic diseases has attracted increasing attention from researchers. By carrying biological microRNAs or active proteins, MSC-sEV can modulate the function of various innate and adaptive immune cells. In this review, we summarise the recent advances in the immunomodulatory properties of MSCs in allergic diseases, the cellular sources of MSC-sEV, and the methods for obtaining high-quality human MSC-sEV. In addition, we discuss the immunoregulatory capacity of MSCs and MSC-sEV for the treatment of asthma, atopic dermatitis, and allergic rhinitis, with a special emphasis on their immunoregulatory effects and the underlying mechanisms of immune cell modulation.

Stem cells in treatment of crohn's disease: Recent advances and future directions

BACKGROUND AND AIM

Crohn's disease (CD) is an inflammatory bowel disease that can affect any part of the intestine. There is currently no recognized cure for CD because its cause is unknown. One of the modern approaches that have been suggested for the treatment of CD and other inflammatory-based disorders is cell therapy.

METHODS

Search terms were stem cell therapy, CD, adipose-derived stem cells, mesenchymal stem cells, and fistula. Of 302 related studies, we removed duplicate and irrelevant papers and identified the ones with proper information related to our scope of the research by reviewing all the abstracts and categorizing each study into the proper section.

RESULTS AND CONCLUSION

Nowadays, stem cell therapy is widely implied in treating CD. Although mesenchymal and adipose-derived tissue stem cells proved to be safe in treating Crohn's-associated fistula, there are still debates on an optimal protocol to use. Additionally, there is still a lack of evidence on the efficacy of stem cell therapy for intestinal involvement of CD. Future investigations should focus on preparing a standard protocol as well as luminal stem cell therapy in patients.

A Supportive Role of Mesenchymal Stem Cells on Insulin-Producing Langerhans Islets with a Specific Emphasis on The Secretome

Type 1 Diabetes (T1D) is a chronic autoimmune disease characterized by a gradual destruction of insulin-producing β-cells in the endocrine pancreas due to innate and specific immune responses, leading to impaired glucose homeostasis. T1D patients usually require regular insulin injections after meals to maintain normal serum glucose levels. In severe cases, pancreas or Langerhans islet transplantation can assist in reaching a sufficient β-mass to normalize glucose homeostasis. The latter procedure is limited because of low donor availability, high islet loss, and immune rejection. There is still a need to develop new technologies to improve islet survival and implantation and to keep the islets functional. Mesenchymal stem cells (MSCs) are multipotent non-hematopoietic progenitor cells with high plasticity that can support human pancreatic islet function both in vitro and in vivo and islet co-transplantation with MSCs is more effective than islet transplantation alone in attenuating diabetes progression. The beneficial effect of MSCs on islet function is due to a combined effect on angiogenesis, suppression of immune responses, and secretion of growth factors essential for islet survival and function. In this review, various aspects of MSCs related to islet function and diabetes are described.

Mesenchymal Stromal Cell-Derived Small Extracellular Vesicles Modulate Apoptosis, TNF Alpha and Interferon Gamma Response Gene mRNA Expression in T Lymphocytes

Recent studies have highlighted the therapeutic potential of small extracellular bodies derived from mesenchymal stem cells (MSC-sEVs) for various diseases, notably through their ability to alter T-cell differentiation and function. The current study aimed to explore immunomodulatory pathway alterations within T cells through mRNA sequencing of activated T cells cocultured with bone marrow-derived MSC-sEVs. mRNA profiling of activated human T cells cocultured with MSC-sEVs or vehicle control was performed using the QIAGEN Illumina sequencing platform. Pathway networks and biological functions of the differentially expressed genes were analyzed using Ingenuity pathway analysis (IPA)® software, KEGG pathway, GSEA and STRING database. A total of 364 differentially expressed genes were identified in sEV-treated T cells. Canonical pathway analysis highlighted the RhoA signaling pathway. Cellular development, movement, growth and proliferation, cell-to-cell interaction and inflammatory response-related gene expression were altered. KEGG enrichment pathway analysis underscored the apoptosis pathway. GSEA identified enrichment in downregulated genes associated with TNF alpha and interferon gamma response, and upregulated genes related to apoptosis and migration of lymphocytes and T-cell differentiation gene sets. Our findings provide valuable insights into the mechanisms by which MSC-sEVs implement immunomodulatory effects on activated T cells. These findings may contribute to the development of MSC-sEV-based therapies.

The developing role of extracellular vesicles in autoimmune diseases: special attention to mesenchymal stem cell-derived extracellular vesicles

Autoimmune diseases are complex, chronic inflammatory conditions initiated by the loss of immunological tolerance to self-antigens. Nowadays, there is no effective and useful therapy for autoimmune diseases, and the existing medications have some limitations due to their nonspecific targets and side effects. During the last few decades, it has been established that mesenchymal stem cells (MSCs) have immunomodulatory functions. It is proposed that MSCs can exert an important therapeutic effect on autoimmune disorders. In parallel with these findings, several investigations have shown that MSCs alleviate autoimmune diseases. Intriguingly, the results of studies have demonstrated that the effective roles of MSCs in autoimmune diseases do not depend on direct intercellular communication but on their ability to release a wide spectrum of paracrine mediators such as growth factors, cytokines and extracellular vehicles (EVs). EVs that range from 50 to 5,000 nm were produced by almost any cell type, and these nanoparticles participate in homeostasis and intercellular communication via the transfer of a broad range of biomolecules such as modulatory proteins, nucleic acids (DNA and RNA), lipids, cytokines, and metabolites. EVs derived from MSCs display the exact properties of MSCs and can be safer and more beneficial than their parent cells. In this review, we will discuss the features of MSCs and their EVs, EVs biogenesis, and their cargos, and then we will highlight the existing discoveries on the impacts of EVs from MSCs on autoimmune diseases such as multiple sclerosis, arthritis rheumatic, inflammatory bowel disease, Type 1 diabetes mellitus, systemic lupus erythematosus, autoimmune liver diseases, Sjögren syndrome, and osteoarthritis, suggesting a potential alternative for autoimmune conditions therapy.

Engineered Cytokine-Primed Extracellular Vesicles with High PD-L1 Expression Ameliorate Type 1 Diabetes

Type 1 diabetes (T1D), which is a chronic autoimmune disease, results from the destruction of insulin-producing β cells targeted by autoreactive T cells. The recent discovery that mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) function as therapeutic tools for autoimmune conditions has attracted substantial attention. However, the in vivo distribution and therapeutic effects of MSC-EVs potentiated by pro-inflammatory cytokines in the context of T1D have yet to be established. Here, it is reported that hexyl 5-aminolevulinate hydrochloride (HAL)-loaded engineered cytokine-primed MSC-EVs (H@TI-EVs) with high expression of immune checkpoint molecule programmed death-legend 1 (PD-L1) exert excellent inflammatory targeting and immunosuppressive effects for T1D imaging and therapy. The accumulated H@TI-EVs in injured pancreas not only enabled the fluorescence imaging and tracking of TI-EVs through the intermediate product protoporphyrin (PpIX) generated by HAL, but also promoted the proliferative and anti-apoptotic effects of islet β cells. Further analysis revealed that H@TI-EVs exhibited an impressive ability to reduce CD4+ T cell density and activation through the PD-L1/PD-1 axis, and induced M1-to-M2 macrophage transition to reshape the immune microenvironment, exhibiting high therapeutic efficiency in mice with T1D. This work identifies a novel strategy for the imaging and treatment of T1D with great potential for clinical application.

The role of mesenchymal stem cells derived exosomes as a novel nanobiotechnology target in the diagnosis and treatment of cancer

Mesenchymal stem cells (MSCs), one of the most common types of stem cells, are involved in the modulation of the tumor microenvironment (TME). With the advancement of nanotechnology, exosomes, especially exosomes secreted by MSCs, have been found to play an important role in the initiation and development of tumors. In recent years, nanobiotechnology and bioengineering technology have been gradually developed to detect and identify exosomes for diagnosis and modify exosomes for tumor treatment. Several novel therapeutic strategies bioengineer exosomes to carry drugs, proteins, and RNAs, and further deliver their encapsulated cargoes to cancer cells through the properties of exosomes. The unique properties of exosomes in cancer treatment include targeting, low immunogenicity, flexibility in modification, and high biological barrier permeability. Nevertheless, the current comprehensive understanding of the roles of MSCs and their secreted exosomes in cancer development remain inadequate. It is necessary to better understand/update the mechanism of action of MSCs-secreted exosomes in cancer development, providing insights for better modification of exosomes through bioengineering technology and nanobiotechnology. Therefore, this review focuses on the role of MSCs-secreted exosomes and bioengineered exosomes in the development, progression, diagnosis, and treatment of cancer.

Dendritic cells mediated by small extracellular vesicles derived from MSCs attenuated the ILC2 activity via PGE2 in patients with allergic rhinitis

BACKGROUND

Mesenchymal stromal cells-derived small extracellular vesicles (MSC-sEVs) have recently attracted considerable attention because of their therapeutic potential in various immune diseases. We previously reported that MSC-sEVs could exert immunomodulatory roles in allergic airway inflammation by regulating group 2 innate lymphoid cell (ILC2) and dendritic cell (DC) functions. Therefore, this study aimed to investigate the indirect effects of MSC-sEVs on ILC2s from patients with allergic rhinitis (AR) via DCs.

METHODS

Here, we isolated sEVs from induced pluripotent stem cells-MSCs using anion-exchange chromatography and mature DCs (mDCs) were treated with MSC-sEVs. sEV-mDCs were co-cultured with peripheral blood mononuclear cells from patients with AR or purified ILC2s. The levels of IL-13 and GATA3 in ILC2s were examined by flow cytometry. Bulk RNA sequence for mDCs and sEV-mDCs was employed to further probe the potential mechanisms, which were then validated in the co-culture systems.

RESULTS

sEV-mDCs showed impaired capacity in priming the levels of IL-13 and GATA3 in ILC2s when compared with mDCs. Furthermore, there was higher PGE2 and IL-10 production from sEV-mDCs, and the blockade of them especially the former one reversed the inhibitory effects of sEV-mDCs.

CONCLUSIONS

We demonstrated that MSC-sEVs were able to dampen the activating effects of mDCs on ILC2s in patients with AR. Mechanismly, the PGE2-EP2/4 axis played an essential role in the immunomodulatory effects of sEV-mDCs on ILC2s. Herein, we provided new insights into the mechanism underlying the therapeutic effects of MSC-sEVs in allergic airway inflammation.

Clinical Prospect of Mesenchymal Stromal/Stem Cell-Derived Extracellular Vesicles in Kidney Disease: Challenges and the Way Forward

Kidney disease is a growing public health problem worldwide, including both acute and chronic forms. Existing therapies for kidney disease target various pathogenic mechanisms; however, these therapies only slow down the progression of the disease rather than offering a cure. One of the potential and emerging approaches for the treatment of kidney disease is mesenchymal stromal/stem cell (MSC) therapy, shown to have beneficial effects in preclinical studies. In addition, extracellular vesicles (EVs) released by MSCs became a potent cell-free therapy option in various preclinical models of kidney disease due to their regenerative, anti-inflammatory, and immunomodulatory properties. However, there are scarce clinical data available regarding the use of MSC-EVs in kidney pathologies. This review article provides an outline of the renoprotective effects of MSC-EVs in different preclinical models of kidney disease. It offers a comprehensive analysis of possible mechanisms of action of MSC-EVs with an emphasis on kidney disease. Finally, on the journey toward the implementation of MSC-EVs into clinical practice, we highlight the need to establish standardized methods for the characterization of an EV-based product and investigate the adequate dosing, safety, and efficacy of MSC-EVs application, as well as the development of suitable potency assays.

TITLE: New therapeutic approaches in pediatric diseases: Mesenchymal stromal cell and mesenchymal stromal cell-derived extracellular vesicles as new drugs

Mesenchymal Stromal Cell (MSC) clinical applications have been widely reported and their therapeutic potential has been documented in several diseases. MSCs can be isolated from several human tissues and easily expanded in vitro, they are able to differentiate in a variety of cell lineages, and they are known to interact with most immunological cells, showing immunosuppressive and tissue repair properties. Their therapeutic efficacy is closely associated with the release of bioactive molecules, namely Extracellular Vesicles (EVs), effective as their parental cells. EVs isolated from MSCs act by fusing with target cell membrane and releasing their content, showing a great potential for the treatment of injured tissues and organs, and for the modulation of the host immune system. EV-based therapies provide, as major advantages, the possibility to cross the epithelium and blood barrier and their activity is not influenced by the surrounding environment. In the present review, we deal with pre-clinical reports and clinical trials to provide data in support of MSC and EV clinical efficacy with particular focus on neonatal and pediatric diseases. Considering pre-clinical and clinical data so far available, it is likely that cell-based and cell-free therapies could become an important therapeutic approach for the treatment of several pediatric diseases.

Versatility of mesenchymal stem cell-derived extracellular vesicles in tissue repair and regenerative applications

Mesenchymal stem/stromal cells (MSCs) are multipotent somatic cells that have been widely explored in the field of regenerative medicine. MSCs possess the ability to secrete soluble factors as well as lipid bound extracellular vesicles (EVs). MSCs have gained increased interest and attention as a result of their therapeutic properties, which are thought to be attributed to their secretome. However, while the use of MSCs as whole cells pose heterogeneity concerns and survival issues post-transplantation, such limitations are absent in cell-free EV-based treatments. EVs derived from MSCs are promising therapeutic agents for a range of clinical conditions and disorders owing to their immunomodulatory, pro-regenerative, anti-inflammatory, and antifibrotic activity. Recent successes with preclinical studies using EVs for repair and regeneration of damaged tissues such as cardiac tissue, lung, liver, pancreas, bone, skin, cornea, and blood diseases are discussed in this review. We also discuss delivery strategies of EVs using biomaterials as delivery vehicles through systemic or local administration. Despite its effectiveness in preclinical investigations, the application of MSC-EV in clinical settings will necessitate careful consideration surrounding issues such as: i) scalability and isolation, ii) biodistribution, iii) targeting specific tissues, iv) quantification and characterization, and v) safety and efficacy of dosage. The future of EVs in regenerative medicine is promising yet still needs further investigation on enhancing the efficacy, scalability, and potency for clinical applications.

Inhibitory Effects of Extracellular Vesicles from iPS-Cell-Derived Mesenchymal Stem Cells on the Onset of Sialadenitis in Sjögren's Syndrome Are Mediated by Immunomodulatory Splenocytes and Improved by Inhibiting miR-125b

Extracellular vesicles (EVs) from allogeneic-tissue-derived mesenchymal stem cells (MSCs) are promising to improve Sjögren's syndrome (SS) treatment, but their application is hindered by high variations in and limited expandability of tissue MSCs. We derived standardized and scalable MSCs from iPS cells (iMSCs) and reported that EVs from young but not aging iMSCs (iEVs) inhibited sialadenitis onset in SS mouse models. Here, we aim to determine cellular mechanisms and optimization approaches of SS-inhibitory effects of iEVs. In NOD.B10.H2b mice at the pre-disease stage of SS, we examined the biodistribution and recipient cells of iEVs with imaging, flow cytometry, and qRT-PCR. Intravenously infused iEVs accumulated in the spleen but not salivary glands or cervical lymph nodes and were mainly taken up by macrophages. In the spleen, young but not aging iEVs increased M2 macrophages, decreased Th17 cells, and changed expression of related immunomodulatory molecules. Loading miR-125b inhibitors into aging iEVs significantly improved their effects on repressing sialadenitis onset and regulating immunomodulatory splenocytes. These data indicated that young but not aging iEVs suppress SS onset by regulating immunomodulatory splenocytes, and inhibiting miR-125b in aging iEVs restores such effects, which is promising to maximize production of effective iEVs from highly expanded iMSCs for future clinical application.

Exosomes from bone marrow-derived mesenchymal stem cells facilitate corneal wound healing via regulating the p44/42 MAPK pathway

PURPOSE

This study was aimed at exploring the function of Exosomes isolated from bone marrow-derived mesenchymal stem cells (BMSC-Exos) in corneal wound healing and at revealing the underlying mechanisms involving the p44/42 mitogen-activated protein kinase (MAPK) pathway.

METHODS

The isolated BMSC-Exos were identified by transmission electron microscopy, Western blot, and nanoparticle tracking analysis. After coculture with BMSC-Exos, the proliferation and migration of human corneal epithelial cells (HCEs) were evaluated. The protein expression of p-MEK/MEK and p44/42 MAPK was detected by Western blot. A mouse model of alkali-burned cornea was established via NaOH exposure. After injection with BMSC-Exos, the pathological changes and expression of α-SMA (a fibrosis marker) and CD31 (a vascularization marker) in corneal tissues were detected.

RESULTS

BMSC-Exos enhanced the proliferation and migration of HCEs in a dose-dependent manner. The p44/42 MAPK pathway was activated by the treatment of BMSC-Exos, and its blocking using U0126 partially abrogated the effects of BMSC-Exos on promoting the proliferation and migration of HCEs. In vivo, the injection of BMSC-Exos facilitated the remission of the pathological changes (inflammation) and weakened the upregulation of α-SMA (fibrosis) and CD31 (vascularization) in corneal tissues of mice with alkali-burn injury.

CONCLUSION

BMSC-Exos promoted the proliferation and migration of HCEs via activating the p44/42 MAPK pathway in vitro and also inhibited alkali burn-induced inflammation, fibrosis, and vascularization in corneal tissues in vivo. BMSC-Exos may be promising resources for promoting corneal wound healing.

Title: Immunotherapy; a ground-breaking remedy for spinal cord injury with stumbling blocks: An overview

Spinal cord injury (SCI) is a debilitating disorder with no known standard and effective treatment. Despite its ability to exacerbate SCI sequel by accelerating auto-reactive immune cells, an immune response is also considered essential to the healing process. Therefore, immunotherapeutic strategies targeting spinal cord injuries may benefit from the dual nature of immune responses. An increasing body of research suggests that immunization against myelin inhibitors can promote axon remyelination after SCI. However, despite advancements in our understanding of neuroimmune responses, immunoregulation-based therapeutic strategies have yet to receive widespread acceptance. Therefore, it is a prerequisite to enhance the understanding of immune regulation to ensure the safety and efficacy of immunotherapeutic treatments. The objective of the present study was to provide an overview of previous studies regarding the advantages and limitations of immunotherapeutic strategies for functional recovery after spinal cord injury, especially in light of limiting factors related to DNA and cell-based vaccination strategies by providing a novel prospect to lay the foundation for future studies that will help devise a safe and effective treatment for spinal cord injury.

Mechanisms behind therapeutic potentials of mesenchymal stem cell mitochondria transfer/delivery

Mesenchymal stromal/stem cells (MSCs) perform their therapeutic effects through various mechanisms, including their ability to differentiate, producing different growth factors, immunomodulatory factors, and extracellular vesicles (EVs). In addition to the mentioned mechanisms, a new aspect of the therapeutic potential of MSCs has recently been noticed, which occurs through mitochondrial transfer. Various methods of MSCs mitochondria transfer have been used in studies to benefit from their therapeutic potential. Among these methods, mitochondrial transfer after MSCs transplantation in cell-to-cell contact, EVs-mediated transfer of mitochondria, and the use of MSCs isolated mitochondria (MSCs-mt) are well studied. Pathological conditions can affect the cells in the damaged microenvironment and lead to cells mitochondrial damage. Since the defect in the mitochondrial function of the cell leads to a decrease in ATP production and the subsequent cell death, restoring the mitochondrial content, functions, and hemostasis can affect the functions of the damaged cell. Various studies show that the transfer of MSCs mitochondria to other cells can affect vital processes such as proliferation, differentiation, cell metabolism, inflammatory responses, cell senescence, cell stress, and cell migration. These changes in cell attributes and behavior are very important for therapeutic purposes. For this reason, their investigation can play a significant role in the direction of the researchers'.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: New Soldiers in the War on Immune-Mediated Diseases

Inflammatory diseases are a group of debilitating disorders with varying degrees of long-lasting functional impairment of targeted system. New therapeutic agents that will attenuate on-going inflammation and, at the same time, promote regeneration of injured organ are urgently needed for the treatment of autoimmune and inflammatory disorders. During the last decade numerous studies have demonstrated that crucial therapeutic benefits of mesenchymal stem cells (MSCs) in inflammatory diseases are based on the effects of MSC-produced paracrine mediators and not on the activity of engrafted cells themselves. Thus, to overcome the limitations of stem cell transplantation, MSC-derived extracellular vesicles (MSC-EVs) have been rigorously investigated, as a promising cell-free pharmaceutical component. In this review, we focus on the mechanisms of MSC-EV covering the current knowledge on their potential therapeutic applications for immune-mediated diseases.

Immunomodulatory potential of mesenchymal stem cell-derived extracellular vesicles: Targeting immune cells

Various intractable inflammatory diseases caused by disorders of immune systems have pressed heavily on public health. Innate and adaptive immune cells as well as secreted cytokines and chemokines are commanders to mediate our immune systems. Therefore, restoring normal immunomodulatory responses of immune cells is crucial for the treatment of inflammatory diseases. Mesenchymal stem cell derived extracellular vesicles (MSC-EVs) are nano-sized double-membraned vesicles acting as paracrine effectors of MSCs. MSC-EVs, containing a variety of therapeutic agents, have shown great potential in immune modulation. Herein, we discuss the novel regulatory functions of MSC-EVs from different sources in the activities of innate and adaptive immune cells like macrophages, granulocytes, mast cells, natural killer (NK) cells, dendritic cells (DCs) and lymphocytes. Then, we summarize the latest clinical trials of MSC-EVs in inflammatory diseases. Furthermore, we prospect the research trend of MSC-EVs in the field of immune modulation. Despite the fact that the research on the role of MSC-EVs in regulating immune cells is in infancy, this cell-free therapy based on MSC-EVs still offers a promising solution for the treatment of inflammatory diseases.

Therapeutic potential of mesenchymal stromal/stem cells in critical-care patients with systemic inflammatory response syndrome

BACKGROUND

Despite notable advances in the support and treatment of patients admitted to the intensive care unit (ICU), the management of those who develop a systemic inflammatory response syndrome (SIRS) still constitutes an unmet medical need.

MAIN BODY

Both the initial injury (trauma, pancreatitis, infections) and the derived uncontrolled response promote a hyperinflammatory status that leads to systemic hypotension, tissue hypoperfusion and multiple organ failure. Mesenchymal stromal/stem cells (MSCs) are emerging as a potential therapy for severe ICU patients due to their potent immunomodulatory, anti-inflammatory, regenerative and systemic homeostasis-regulating properties. MSCs have demonstrated clinical benefits in several inflammatory-based diseases, but their role in SIRS needs to be further explored.

CONCLUSION

In the current review, after briefly overviewing SIRS physiopathology, we explore the potential mechanisms why MSC therapy could aid in the recovery of this condition and the pre-clinical and early clinical evidence generated to date.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: A Potential Therapy for Diabetes Mellitus and Diabetic Complications

As a novel cell-free strategy, mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) inherit the therapeutic potential of donor cells, and are widely used for the treatment of many diseases. Increasing studies have shown that MSC-EVs transfer various bioactive molecules to create a beneficial microenvironment, thus exerting protective roles in diabetic mellitus (DM) and diabetic complications. To overcome the limitations of natural MSC-EVs such as heterogeneity and insufficient function, several modification methods have been established for constructing engineered MSC-EVs with elevated repairing efficiency. In this review, the PubMed library was searched from inception to August 2022, using a combination of Medical Subject Headings (MeSH) and keywords related to MSC-EVs, DM, and diabetic complications. We provide an overview of the major characteristics of MSC-EVs and summarize the recent advances of MSC-EV-based therapy for hyperglycemia-induced tissue damage with an emphasis on MSC-EV-mediated delivery of functional components. Moreover, the potential applications of engineered MSC-EVs in DM-related diseases therapy are discussed by presenting examples, and the opportunities and challenges for the clinical translation of MSC-EVs, especially engineered MSC-EVs, are evaluated.

Pathophysiology of Sepsis and Genesis of Septic Shock: The Critical Role of Mesenchymal Stem Cells (MSCs)

The treatment of sepsis and septic shock remains a major public health issue due to the associated morbidity and mortality. Despite an improvement in the understanding of the physiological and pathological mechanisms underlying its genesis and a growing number of studies exploring an even higher range of targeted therapies, no significant clinical progress has emerged in the past decade. In this context, mesenchymal stem cells (MSCs) appear more and more as an attractive approach for cell therapy both in experimental and clinical models. Pre-clinical data suggest a cornerstone role of these cells and their secretome in the control of the host immune response. Host-derived factors released from infected cells (i.e., alarmins, HMGB1, ATP, DNA) as well as pathogen-associated molecular patterns (e.g., LPS, peptidoglycans) can activate MSCs located in the parenchyma and around vessels to upregulate the expression of cytokines/chemokines and growth factors that influence, respectively, immune cell recruitment and stem cell mobilization. However, the way in which MSCs exert their beneficial effects in terms of survival and control of inflammation in septic states remains unclear. This review presents the interactions identified between MSCs and mediators of immunity and tissue repair in sepsis. We also propose paradigms related to the plausible roles of MSCs in the process of sepsis and septic shock. Finally, we offer a presentation of experimental and clinical studies and open the way to innovative avenues of research involving MSCs from a prognostic, diagnostic, and therapeutic point of view in sepsis.

Mesenchymal stem/stromal cells in the pathogenesis and regenerative therapy of inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) represent a group of chronic inflammatory disorders of the gastrointestinal (GI) tract including ulcerative colitis (UC), Crohn’s disease (CD), and unclassified IBDs. The pathogenesis of IBDs is related to genetic susceptibility, environmental factors, and dysbiosis that can lead to the dysfunction of immune responses and dysregulated homeostasis of local mucosal tissues characterized by severe inflammatory responses and tissue damage in GI tract. To date, extensive studies have indicated that IBDs cannot be completely cured and easy to relapse, thus prompting researchers to find novel and more effective therapeutics for this disease. Due to their potent multipotent differentiation and immunomodulatory capabilities, mesenchymal stem/stromal cells (MSCs) not only play an important role in regulating immune and tissue homeostasis but also display potent therapeutic effects on various inflammatory diseases, including IBDs, in both preclinical and clinical studies. In this review, we present a comprehensive overview on the pathological mechanisms, the currently available therapeutics, particularly, the potential application of MSCs-based regenerative therapy for IBDs.

Mesenchymal Stem Cell-Derived Secretome: A Potential Therapeutic Option for Autoimmune and Immune-Mediated Inflammatory Diseases

Immune-mediated inflammatory diseases (IMIDs) encompass several entities such as "classic" autoimmune disorders or immune-mediated diseases with autoinflammatory characteristics. Adult stem cells including mesenchymal stem cells (MSCs) are by far the most commonly used type in clinical practice. However, due to the possible side effects of MSC-based treatments, there is an increase in interest in the MSC-secretome (containing large extracellular vesicles, microvesicles, and exosomes) as an alternative therapeutic option in IMIDs. A wide spectrum of MSC-secretome-related biological activities has been proven thus far including anti-inflammatory, anti-apoptotic, and immunomodulatory properties. In comparison with MSCs, the secretome is less immunogenic but exerts similar biological actions, so it can be considered as an ideal cell-free therapeutic alternative. Additionally, since the composition of the MSC-secretome can be engineered, for a future perspective, it could also be viewed as part of a potential delivery system within nanomedicine, allowing us to specifically target dysfunctional cells or tissues. Although many encouraging results from pre-clinical studies have recently been obtained that strongly support the application of the MSC-secretome in IMIDs, human studies with MSC-secretome administration are still in their infancy. This article reviews the immunomodulatory effects of the MSC-secretome in IMIDs and provides insight into the interpretation of its beneficial biological actions.

Knowledge Mapping of Exosomes in Autoimmune Diseases: A Bibliometric Analysis (2002–2021)

Background

Autoimmune diseases (AIDs) are a class of chronic disabling diseases characterized by inflammation and damage to muscles, joints, bones, and internal organs. Recent studies have shown that much progress has been made in the research of exosomes in AIDs. However, there is no bibliometric analysis in this research field. This study aims to provide a comprehensive overview of the knowledge structure and research hotspots of exosomes in AIDs through bibliometrics.

Method

Publications related to exosomes in AIDs from 2002 to 2021 were searched on the web of science core collection (WoSCC) database. VOSviewers, CiteSpace and R package “bibliometrix” were used to conduct this bibliometric analysis.

Results

312 articles from 48 countries led by China and the United States were included. The number of publications related to exosomes in AIDs is increasing year by year. Central South University, Sun Yat Sen University, Tianjin Medical University and University of Pennsylvania are the main research institutions. Frontiers in immunology is the most popular journal in this field, and Journal of Immunology is the most co-cited journal. These publications come from 473 authors among which Ilias Alevizos, Qianjin Lu, Wei Wei, Jim Xiang and Ming Zhao had published the most papers and Clotilde Théry was co-cited most often. Studying the mechanism of endogenous exosomes in the occurrence and development of AIDs and the therapeutic strategy of exogenous exosomes in AIDs are the main topics in this research field. “Mesenchymal stem cells”, “microRNA”, “biomarkers”, “immunomodulation”, and “therapy” are the primary keywords of emerging research hotspots.

Conclusion

This is the first bibliometric study that comprehensively summarizes the research trends and developments of exosomes in AIDs. This information identifies recent research frontiers and hot directions, which will provide a reference for scholars studying exosomes.

Extracellular vesicles in β cell biology: Role of lipids in vesicle biogenesis, cargo, and intercellular signaling

BACKGROUND

Type 1 diabetes (T1D) is a complex autoimmune disorder whose pathogenesis involves an intricate interplay between β cells of the pancreatic islet, other islet cells, and cells of the immune system. Direct intercellular communication within the islet occurs via cell surface proteins and indirect intercellular communication has traditionally been seen as occurring via secreted proteins (e.g., endocrine hormones and cytokines). However, recent literature suggests that extracellular vesicles (EVs) secreted by β cells constitute an additional and biologically important mechanism for transmitting signals to within the islet.

SCOPE OF REVIEW

This review summarizes the general mechanisms of EV formation, with a particular focus on how lipids and lipid signaling pathways influence their formation and cargo. We review the implications of EV release from β cells for T1D pathogenesis, how EVs and their cargo might be leveraged as biomarkers of this process, and how EVs might be engineered as a therapeutic candidate to counter T1D outcomes.

MAJOR CONCLUSIONS

Islet β cells have been viewed as initiators and propagators of the cellular circuit giving rise to autoimmunity in T1D. In this context, emerging literature suggests that EVs may represent a conduit for communication that holds more comprehensive messaging about the β cells from which they arise. As the field of EV biology advances, it opens the possibility that intervening with EV formation and cargo loading could be a novel disease-modifying approach in T1D.

An Overview of Current Research on Mesenchymal Stem Cell-Derived Extracellular Vesicles: A Bibliometric Analysis From 2009 to 2021

Background: Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) are important mediators of intercellular communication and participate in numerous physiological and pathological processes in the body. This study aims to introduce the research status, analyze the research hotspots, and predict the development trend through bibliometric analysis of MSC-EVs.

Methods: We searched all relevant literature on MSC-EVs from 2009 to 2021 in the Web of Science. R-bibliometrix, VOSviewer, and CiteSpace software were used to visualize the quantitative analysis of the published literature, including co-authorship, co-occurrence, citation, and co-citation, to provide objective presentation and predictions in the field.

Results: A total of 1595 articles and reviews on MSC-EVs published between 2009 and 2021 were identified. The annual publication outputs increased at an exponential rate, reaching as high as 555 publications in 2021. China contributed the most publications (n = 899, 56.36%) and had the most citations (n = 24,210). The United States had the strongest intensity of cooperation in this field. Shanghai Jiao Tong University had the maximum number of publications (n = 79). In terms of the number of publications and co-citations, the journal of Stem cell research & therapy ranked first. Camussi G was the most productive and most cited author. The top three themes in the research area were cell biology, research experimental medicine, and biochemistry molecular biology. Keyword co-occurrence and co-citation clustering analysis revealed that studies of MSC-EVs covered cellular origin (bone marrow mesenchymal stem cell, adipose-derived mesenchymal stem cell), injurious diseases (spinal cord injury, acute lung injury, ischemia/reperfusion injury, acute kidney injury, traumatic brain injury), tumor (breast cancer, tumor microenvironment), biological processes (drug delivery system, angiogenesis, inflammation, proliferation, differentiation, senescence), and molecular mechanisms (signaling pathway, signal transduction, oxidative stress, VEGF, TGF β).

Conclusions: Studies on MSC-EVs have shown a steep growth trend in recent years. Available studies mostly focused on the therapeutic effects and underlying mechanisms of MSC-EVs in aplastic diseases. Multidisciplinary integration is a development trend in this field, and senescence-related topics might be the focus of future research on MSC-EVs.

A Bibliometric Analysis of the Hotspots Concerning Stem Cell Extracellular Vesicles for Diabetes in the Last 5 Years

Background:

Diabetes mellitus (DM) is a metabolic disease that endangers human health, and its prevalence is exploding and younger. Stem cell-derived extracellular vesicles (SC-EVs) have a repair function similar to SCs and no risk of tumor formation, which have been widely used in the repair of DM and its complications. We aim to map the hot trends of SC-EVs for the treatment of DM and providing directions for future research.

Methods

We screened all relevant publications on SC-EVs for DM from the Web of Science (Wos) during 2017–2021, and research trends in this field were analyzed by VOSviewer and CiteSpace.

Results

A total of 255 articles related to SC-EVs for DM were screened out according to the search strategy. China (122 publications and 2,759 citations) was the most productive country, followed by the USA (50 publications and 1,167 citations) and Italy (16 publications and 366 citations). The top five institutions with the most publications were located in Italy and China, with Turin University being the most productive. The journals Stem Cell Research and Therapy and International Journal of Molecular Sciences published most of the studies on SC-EVs for DM. ASHOK KUMAR published the majority of articles in this field, while QING LI was the most cited. Cluster analysis indicated that the current research trend is more focused on the repair mechanism and clinical translation of exosomes and their related preparations in promoting DM and its complications.

Conclusion

In this study, a comprehensive summary and analysis of the global research trends of SC-EVs used in DM and its complications was performed. In the past 5 years, relevant high-quality publications in this field have increased significantly, and SC-EVs have a good prospect for development in the treatment of DM and its complications.

Anti-Oxidative Therapy in Islet Cell Transplantation

Islet cell transplantation has become a favorable therapeutic approach in the treatment of Type 1 Diabetes due to the lower surgical risks and potential complications compared to conventional pancreas transplantation. Despite significant improvements in islet cell transplantation outcomes, several limitations hamper long-term graft survival due to tremendous damage and loss of islet cells during the islet cell transplantation process. Oxidative stress has been identified as an omnipresent stressor that negatively affects both the viability and function of isolated islets. Furthermore, it has been established that at baseline, pancreatic β cells exhibit reduced antioxidative capacity, rendering them even more susceptible to oxidative stress during metabolic stress. Thus, identifying antioxidants capable of conferring protection against oxidative stressors present throughout the islet transplantation process is a valuable approach to improving the overall outcomes of islet cell transplantation. In this review we discuss the potential application of antioxidative therapy during each step of islet cell transplantation.

Mesenchymal stromal cells-derived small extracellular vesicles modulate DC function to suppress Th2 responses via IL-10 in patients with allergic rhinitis

Mesenchymal stromal cells (MSCs) are well known for their immunoregulatory roles on allergic inflammation particularly by acting on T cells, B cells, and dendritic cells (DCs). MSC‐derived small extracellular vesicles (MSC‐sEV) are increasingly considered as one of the main factors for the effects of MSCs on immune responses. However, the effects of MSC‐sEV on DCs in allergic diseases remain unclear.

Extracellular Vesicle Therapy for Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic disorder characterized by immune-mediated destruction of pancreatic insulin-producing β-cells. The primary treatment for T1D is multiple daily insulin injections to control blood sugar levels. Cell-free delivery packets with therapeutic properties, extracellular vesicles (EVs), mainly from stem cells, have recently gained considerable attention for disease treatments. EVs provide a great potential to treat T1D ascribed to their regenerative, anti-inflammatory, and immunomodulatory effects. Here, we summarize the latest EV applications for T1D treatment and highlight opportunities for further investigation.

Type 1 Diabetes and Associated Cardiovascular Damage: Contribution of Extracellular Vesicles in Tissue Crosstalk

Significance: Type 1 diabetes (T1D) is characterized by the autoimmune destruction of the insulin secreting β-cells, with consequent aberrant blood glucose levels. Hyperglycemia is the common denominator for most of the chronic diabetic vascular complications, which represent the main cause of life reduction in T1D patients. For this disease, three interlaced medical needs remain: understanding the underlying mechanisms involved in pancreatic β-cell loss; identifying biomarkers able to predict T1D progression and its related complications; recognizing novel therapeutic targets. Recent Advances: Extracellular vesicles (EVs), released by most cell types, were discovered to contain a plethora of different molecules (including microRNAs) with regulatory properties, which are emerging as mediators of cell-to-cell communication at the paracrine and endocrine level. Recent knowledge suggests that EVs may act as pathogenic factors, and be developed into disease biomarkers and therapeutic targets in the context of several human diseases. Critical Issues: EVs have been recently shown to sustain a dysregulated cellular crosstalk able to exacerbate the autoimmune response in the pancreatic islets of T1D; moreover, EVs were shown to be able to monitor and/or predict the progression of T1D and the insurgence of vasculopathies. Future Directions: More mechanistic studies are needed to investigate whether the dysregulation of EVs in T1D patients is solely reflecting the progression of diabetes and related complications, or EVs also directly participate in the disease process, thus pointing to a potential use of EVs as therapeutic targets/tools in T1D. Antioxid. Redox Signal. 36, 631-651.

Effect of small extracellular vesicles derived from IL-10-overexpressing mesenchymal stem cells on experimental autoimmune uveitis

BACKGROUND

Autoimmune uveitis is a sight-threatening intraocular inflammation mainly caused by immune dysregulation. The development of safe and effective therapeutic approaches is urgently needed. Small extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) have been demonstrated to inhibit autoimmune responses; however, the immunosuppressive effect of MSC-sEVs is too weak for clinical transfer. In the current study, we investigated the therapeutic effect of IL-10-overexpressing MSC-sEVs (sEV-IL10) on experimental autoimmune uveitis (EAU) and studied the underlying mechanism.

METHODS

Mice were randomly grouped and received a single tail vein injection of different sEVs (50 μg) or PBS on day 11 post-immunization. The clinical and histological scores were graded, and the percentage of T helper cell was measured. To investigate the effect of sEVs on the proliferation of T-cells and the differentiation of Th1, Th17 and Treg cells, T-cells were cocultured with sEVs under the corresponding culture conditions. After labeled with PKH-26, sEVs were traced both in vivo and in vitro.

RESULTS

Compared with normal or vector sEV-treated groups, mice in the sEV-IL10-treated group had lower clinical and histological scores with lower percentages of Th1 and Th17 cells in the eyes and higher percentages of Treg cells in the spleen and draining lymph nodes (LN). Furthermore, sEV-IL10 enhanced the suppressive effect of MSC-sEVs on the proliferation of T-cells and differentiation of Th1 and Th17 cells, whereas upregulated the differentiation of Treg cells. Both in vivo and in vitro experiments demonstrated that MSC-sEVs were rapidly enriched in target tissues and internalized by T-cells.

CONCLUSION

These results suggested that sEV-IL10 effectively ameliorates EAU by regulating the proliferation and differentiation of T-cells, indicating sEVs as a potential novel therapy for autoimmune uveitis or other autoimmune diseases.

Mesenchymal Stem Cell-Derived Extracellular Vesicles in Liver Immunity and Therapy

Mesenchymal stem cells (MSCs), as the most common cell source for stem cell therapy, play an important role in the modulation of innate and adaptive immune responses and have been widely used in clinical trials to treat autoimmune and inflammatory diseases. Recent experimental and clinical studies have shown that MSC-derived extracellular vesicles (MSC-EVs) can inhibit the activation and proliferation of a variety of proinflammatory cells, such as Th1, Th17 and M1 macrophages, reducing the secretion of proinflammatory cytokines, while promoting the proliferation of anti-inflammatory cells, such as M2 macrophages and Tregs, and increasing the secretion of anti-inflammatory cytokines, thus playing a role in immune regulation and exhibiting immunomodulatory functions. Besides MSC-EVs are more convenient and less immunogenic than MSCs. There is growing interest in the role of MSC-EVs in liver diseases owing to the intrinsic liver tropism of MSC-EVs. In this review, we focus on the immunomodulatory effects of MSC-EVs and summarize the pivotal roles of MSC-EVs as a cell-free therapy in liver diseases, including NAFLD, AIH, acute liver failure, liver fibrosis and hepatic ischemia–reperfusion injury. Moreover, we provide a concise overview of the potential use and limits of MSC-EVs in clinical application.

Extracellular Vesicles in Type 1 Diabetes: A Versatile Tool

Type 1 diabetes is a chronic autoimmune disease affecting nearly 35 million people. This disease develops as T-cells continually attack the β-cells of the islets of Langerhans in the pancreas, which leads to β-cell death, and steadily decreasing secretion of insulin. Lowered levels of insulin minimize the uptake of glucose into cells, thus putting the body in a hyperglycemic state. Despite significant progress in the understanding of the pathophysiology of this disease, there is a need for novel developments in the diagnostics and management of type 1 diabetes. Extracellular vesicles (EVs) are lipid-bound nanoparticles that contain diverse content from their cell of origin and can be used as a biomarker for both the onset of diabetes and transplantation rejection. Furthermore, vesicles can be loaded with therapeutic cargo and delivered in conjunction with a transplant to increase cell survival and long-term outcomes. Crucially, several studies have linked EVs and their cargos to the progression of type 1 diabetes. As a result, gaining a better understanding of EVs would help researchers better comprehend the utility of EVs in regulating and understanding type 1 diabetes. EVs are a composition of biologically active components such as nucleic acids, proteins, metabolites, and lipids that can be transported to particular cells/tissues through the blood system. Through their varied content, EVs can serve as a flexible aid in the diagnosis and management of type 1 diabetes. In this review, we provide an overview of existing knowledge about EVs. We also cover the role of EVs in the pathogenesis, detection, and treatment of type 1 diabetes and the function of EVs in pancreas and islet β-cell transplantation.

Mesenchymal Stem/Stromal Cells and Their Paracrine Activity-Immunomodulation Mechanisms and How to Influence the Therapeutic Potential

With high clinical interest to be applied in regenerative medicine, Mesenchymal Stem/Stromal Cells have been widely studied due to their multipotency, wide distribution, and relative ease of isolation and expansion in vitro. Their remarkable biological characteristics and high immunomodulatory influence have opened doors to the application of MSCs in many clinical settings. The therapeutic influence of these cells and the interaction with the immune system seems to occur both directly and through a paracrine route, with the production and secretion of soluble factors and extracellular vesicles. The complex mechanisms through which this influence takes place is not fully understood, but several functional manipulation techniques, such as cell engineering, priming, and preconditioning, have been developed. In this review, the knowledge about the immunoregulatory and immunomodulatory capacity of MSCs and their secretion products is revisited, with a special focus on the phenomena of migration and homing, direct cell action and paracrine activity. The techniques for homing improvement, cell modulation and conditioning prior to the application of paracrine factors were also explored. Finally, multiple assays where different approaches were applied with varying success were used as examples to justify their exploration.

The Molecular Mechanisms Through Which Placental Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Myelin Regeneration

Multiple sclerosis (MS) is a debilitating degenerative disease characterized by an immunological attack on the myelin sheath leading to demyelination and axon degeneration. Mesenchymal stem/stromal cells (MSCs) and secreted extracellular vesicles (EVs) have become attractive targets as therapies to treat neurodegenerative diseases such as MS due to their potent immunomodulatory and regenerative properties. The placenta is a unique source of MSCs (PMSCs), demonstrates "fetomaternal" tolerance during pregnancy, and serves as a novel source of MSCs for the treatment of neurodegenerative diseases. PMSCs and PMSC-EVs have been shown to promote remyelination in animal models of MS, however, the molecular mechanisms by which modulation of autoimmunity and promotion of myelination occurs have not been well elucidated. The current review will address the molecular mechanisms by which PMSC-EVs can promote remyelination in MS.

Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Alleviate Psoriasis-like Skin Inflammation

Immunomodulatory effects of mesenchymal stem cells (MSCs) in inflammatory diseases, including psoriasis, are well documented. However, the role of MSC-derived exosomes (MSCs-Exo) in psoriasis-like skin inflammation remains largely unknown. This study aimed to investigate whether MSCs-Exo play a regulatory role in psoriasis-like skin inflammation. We found that subcutaneous injection of human umbilical cord MSCs-Exo (hucMSCs-Exo) significantly suppressed the proliferation of epidermis and reduced Psoriasis Area and Severity Index (PASI) scores in imiquimod (IMQ)-induced mice. hucMSCs-Exo also reduced the expression of interleukin (IL)-17, IL-23, and chemokine C-C-motif ligand 20 (CCL20) and inhibited phosphorylation of signal transducer and activator of transcription 3 (STAT3) in the skin of IMQ-induced mice and in human keratinocyte (HaCaT) cells. In addition, co-cultured with hucMSCs-Exo in vitro, the maturation and activation of dendritic cells (DCs) were suppressed, and the expression level of IL-23 was decreased. These results indicate that hucMSCs-Exo can effectively ameliorate psoriasis-like skin inflammation in mice by regulating the expression of IL-23 and IL-17, and inhibiting the maturation and activation of DCs. Our data offer a promising therapeutic approach for psoriasis by leveraging the immunomodulatory effects of hucMSCs-Exo.

Emerging roles of mesenchymal stem cell-derived exosomes in gastrointestinal cancers

Gastrointestinal tumours are the most common solid tumours, with a poor prognosis and remain a major challenge in cancer treatment. Mesenchymal stem cells (MSC) are multipotent stromal cells with the potential to differentiate into multiple cell types. Several studies have shown that MSC-derived exosomes have become essential regulators of intercellular communication in a variety of physiological and pathological processes. Notably, MSC-derived exosomes support or inhibit tumour progression in different cancers through the delivery of proteins, RNA, DNA, and bioactive lipids. Herein, we summarise current advances in MSC-derived exosomes in cancer research, with particular reference to their role in gastrointestinal tumour development. MSC-derived exosomes are expected to be a novel potential strategy for the treatment of gastrointestinal cancers.

Exosomes Secreted by Umbilical Cord Blood-Derived Mesenchymal Stem Cell Attenuate Diabetes in Mice

Mesenchymal stem cell (MSC) therapy is an innovative approach in diabetes due to its capacity to modulate tissue microenvironment and regeneration of glucose-responsive insulin-producing cells. In this study, we investigated the role of MSC-derived exosomes in pancreatic regeneration and insulin secretion in mice with streptozotocin-induced diabetes. Mesenchymal stem cells (MSCs) were isolated and characterized from umbilical cord blood (UCB). Exosomes were isolated and characterized from these MSCs. Diabetes was induced in male C57Bl/6 mice by streptozotocin (STZ; 40 mg/kg body weight, i.p.) for five consecutive days. The diabetic mice were administered (i.v.) with MSC (1 × 105 umbilical cord blood MSC cells/mice/day), their derived exosomes (the MSC-Exo group that received exosomes derived from 1 × 105 MSC cells/mice/day), or the same volume of PBS. Before administration, the potency of MSCs and their exosomes was evaluated in vitro by T cell activation experiments. After day 7 of the treatments, blood samples and pancreatic tissues were collected. Histochemistry was performed to check cellular architecture and β cell regeneration. In body weight, blood glucose level, and insulin level, cell proliferation assay was done to confirm regeneration of cells after MSC and MSC-Exo treatments. Hyperglycemia was also attenuated in these mice with a concomitant increase in insulin production and an improved histological structure compared to mice in the PBS-treated group. We found increased expression of genes associated with tissue regeneration pathways, including Reg2, Reg3, and Amy2b in the pancreatic tissue of mice treated with MSC or MSC-Exo relative to PBS-treated mice. MicroRNA profiling of MSC-derived exosomes showed the presence of miRs that may facilitate pancreatic regeneration by regulating the Extl3-Reg-cyclinD1 pathway. These results demonstrate a potential therapeutic role of umbilical cord blood MSC-derived exosomes in attenuating insulin deficiency by activating pancreatic islets' regenerative abilities.

Human Wharton's Jelly-Derived Mesenchymal Stromal Cells Primed by Tumor Necrosis Factor-α and Interferon-γ Modulate the Innate and Adaptive Immune Cells of Type 1 Diabetic Patients

The unique immunomodulation and immunosuppressive potential of Wharton’s jelly-derived mesenchymal stromal cells (WJ-MSCs) make them a promising therapeutic approach for autoimmune diseases including type 1 diabetes (T1D). The immunomodulatory effect of MSCs is exerted either by cell-cell contact or by secretome secretion. Cell-cell contact is a critical mechanism by which MSCs regulate immune-responses and generate immune regulatory cells such as tolerogenic dendritic cells (tolDCs) and regulatory T cell (Tregs). In this study, we primed WJ-MSCs with TNF-α and IFN-γ and investigated the immunomodulatory properties of primed WJ-MSCs on mature dendritic cells (mDCs) and activated T cells differentiated from mononuclear cells (MNCs) of T1D patient’s. Our findings revealed that primed WJ-MSCs impaired the antigen-mediated immunity, upregulated immune-tolerance genes and downregulated immune-response genes. We also found an increase in the production of anti-inflammatory cytokines and suppression of the production of pro-inflammatory cytokines. Significant upregulation of FOXP3, IL10 and TGFB1 augmented an immunosuppressive effect on adaptive T cell immunity which represented a strong evidence in support of the formation of Tregs. Furthermore, upregulation of many critical genes involved in the immune-tolerance mechanism (IDO1 and PTGES2/PTGS) was detected. Interestingly, upregulation of ENTPD1/NT5E genes express a strong evidence to switch immunostimulatory response toward immunoregulatory response. We conclude that WJ-MSCs primed by TNF-α and IFN-γ may represent a promising tool to treat the autoimmune disorders and can provide a new evidence to consider MSCs- based therapeutic approach for the treatment of TID.

Effects of Mesenchymal Stem Cell-Derived Exosomes on Autoimmune Diseases

Recent years, the immunosuppressive properties of mesenchymal stem cells (MSCs) have been demonstrated in preclinical studies and trials of inflammatory and autoimmune diseases. Emerging evidence indicates that the immunomodulatory effect of MSCs is primarily attributed to the paracrine pathway. As one of the key paracrine effectors, mesenchymal stem cell-derived exosomes (MSC-EXOs) are small vesicles 30-200 nm in diameter that play an important role in cell-to-cell communication by carrying bioactive substances from parental cells. Recent studies support the finding that MSC-EXOs have an obvious inhibitory effect toward different effector cells involved in the innate and adaptive immune response. Moreover, substantial progress has been made in the treatment of autoimmune diseases, including multiple sclerosis (MS), systemic lupus erythematosus (SLE), type-1 diabetes (T1DM), uveitis, rheumatoid arthritis (RA), and inflammatory bowel disease (IBD). MSC-EXOs are capable of reproducing MSC function and overcoming the limitations of traditional cell therapy. Therefore, using MSC-EXOs instead of MSCs to treat autoimmune diseases appears to be a promising cell-free treatment strategy. In this review, we review the current understanding of MSC-EXOs and discuss the regulatory role of MSC-EXOs on immune cells and its potential application in autoimmune diseases.

Mesenchymal stromal cells: Putative microenvironmental modulators become cell therapy

An exceptional safety profile has been shown in a large number of cell therapy clinical trials that use mesenchymal stromal cells (MSCs). However, reliable potency assays are still lacking to predict MSC immunosuppressive efficacy in the clinical setting. Nevertheless, MSCs are approved in Japan and Europe for the treatment of graft-versus-host and Crohn's fistular diseases, but not in the United States for any clinical indication. We discuss potential mechanisms of action for the therapeutic effects of MSC transplantation, experimental models that dissect tissue modulating function of MSCs, and approaches for identifying MSC effects in vivo by integrating biomarkers of disease and MSC activity.

Extracellular Vesicles as Therapeutic Tools for the Treatment of Chronic Wounds

Chronic wounds develop when the orderly process of cutaneous wound healing is delayed or disrupted. Development of a chronic wound is associated with significant morbidity and financial burden to the individual and health-care system. Therefore, new therapeutic modalities are needed to address this serious condition. Mesenchymal stem cells (MSCs) promote skin repair, but their clinical use has been limited due to technical challenges. Extracellular vesicles (EVs) are particles released by cells that carry bioactive molecules (lipids, proteins, and nucleic acids) and regulate intercellular communication. EVs (exosomes, microvesicles, and apoptotic bodies) mediate key therapeutic effects of MSCs. In this review we examine the experimental data establishing a role for EVs in wound healing. Then, we explore techniques for designing EVs to function as a targeted drug delivery system and how EVs can be incorporated into biomaterials to produce a personalized wound dressing. Finally, we discuss the status of clinically deploying EVs as a therapeutic agent in wound care.

Therapeutic Implications of Mesenchymal Stromal Cells and Their Extracellular Vesicles in Autoimmune Diseases: From Biology to Clinical Applications

Mesenchymal stromal cells (MSCs) are perivascular multipotent stem cells originally identified in the bone marrow (BM) stroma and subsequently in virtually all vascularized tissues. Because of their ability to differentiate into various mesodermal lineages, their trophic properties, homing capacity, and immunomodulatory functions, MSCs have emerged as attractive candidates in tissue repair and treatment of autoimmune disorders. Accumulating evidence suggests that the beneficial effects of MSCs may be primarily mediated via a number of paracrine-acting soluble factors and extracellular vesicles (EVs). EVs are membrane-coated vesicles that are increasingly being acknowledged as playing a key role in intercellular communication via their capacity to carry and deliver their cargo, consisting of proteins, nucleic acids, and lipids to recipient cells. MSC-EVs recapitulate the functions of the cells they originate, including immunoregulatory effects but do not seem to be associated with the limitations and concerns of cell-based therapies, thereby emerging as an appealing alternative therapeutic option in immune-mediated disorders. In the present review, the biology of MSCs will be outlined and an overview of their immunomodulatory functions will be provided. In addition, current knowledge on the features of MSC-EVs and their immunoregulatory potential will be summarized. Finally, therapeutic applications of MSCs and MSC-EVs in autoimmune disorders will be discussed.