Mesenchymal stem cell-derived extracellular vesicles affect disease outcomes via transfer of microRNAs

Fate reversal: Exosome-driven macrophage rejuvenation and bacterial-responsive drug release for infection immunotherapy in diabetes

Superficial surgical site infection (SSI) is a significant risk factor for the development of periprosthetic joint infection (PJI), particularly in diabetic patients. A high-glucose microenvironment is observed to compromise phagocytosis by inducing cellular senescence, which leads to impaired antibacterial immune function. Exosomes derived from umbilical cord stem cells (H-Exos) can reverse the immunosuppressive microenvironment by rejuvenating senescent cells, thereby terminating excessive, persistent, and ineffective inflammatory responses. Thus, a novel exosome-based immunotherapeutic antibacterial strategy to reverse fate is proposed. Vancomycin & lysostaphin-loaded exosomes are incorporated in a customizable microneedle patch (ExoV-ExoL@MN) for controlled release, enabling tailored treatments for diverse clinical scenarios. While rejuvenating macrophage senescent phenotype, the antibiotics encapsulated within exosomes can be responsively released by the hemolysin secreted by bacteria, triggering rapid bacterial killing. Post-infection clearance, they induce a shift from M1 to M2 macrophage polarization, thereby enhancing anti-inflammatory and reparative responses. Furthermore, the components can be mixed on demand and at any time, allowing for real-time customization and fabrication directly at the clinic (fabrication@clinic). This strategy reverses the immunosuppressive microenvironment by rejuvenating senescent macrophages and effectively combats bacterial invasion into deep tissues through bacteria-responsive antibiotic release, providing a promising approach for preventing and treating SSI-induced PJI.

Mesenchymal stem cell-derived exosomes: a novel therapeutic frontier in hematological disorders

Mesenchymal stem cells (MSCs) are multipotent stromal cells valued for their immunomodulatory and regenerative properties, positioning them as a cornerstone of regenerative medicine. Their derived exosomes small extracellular vesicles laden with bioactive molecules such as proteins, lipids, and nucleic acids have emerged as critical mediators of MSC therapeutic effects. This review systematically explores the biology of MSC-derived exosomes, detailing their biogenesis, molecular composition, and pivotal roles in hematopoiesis, inflammation, and immune regulation. In hematological disorders, including leukemia, lymphoma, and myelodysplastic syndromes, these exosomes exhibit significant therapeutic potential by modulating the tumor microenvironment, enhancing hematopoietic recovery, and suppressing malignant cell proliferation. Notable findings include their ability to induce cell cycle arrest in leukemia cells via the p53 pathway and to reduce chemoresistance through targeted signaling mechanisms, such as the IRF2/INPP4B axis. However, clinical translation is hindered by several challenges, including the standardization of isolation techniques such as ultracentrifugation which are costly and susceptible to contamination as well as difficulties in optimizing large-scale production and ensuring long-term safety and efficacy. Despite these obstacles, MSC-derived exosomes offer a promising, cell-free therapeutic alternative that minimizes risks such as immune rejection and tumorigenicity associated with whole-cell therapies. Future research must prioritize the refinement of isolation and production protocols, the development of precise delivery strategies, and the execution of comprehensive safety evaluations to unlock their full clinical potential in treating hematological disorders and beyond. This review integrates recent advancements to provide a clearer understanding of their multifaceted contributions and highlights the critical gaps that remain.

Exosomes derived from mesenchymal stem cells ameliorate impaired glucose metabolism in myocardial Ischemia/reperfusion injury through miR-132-3p/PTEN/AKT pathway

Exosomes secreted by mesenchymal stem cells (MSCs) have been considered as a novel biological therapy for myocardial ischemia/reperfusion injury (MIRI). However, the underlying mechanism of exosomes has not been completely established, especially in the early stage of MIRI. In this study, we primarily investigated the protective effect of exosomes on MIRI from both in vitro and ex vivo perspectives. Bioinformatic analysis was conducted to identify exosomal miRNA associated with myocardial protection, Genes and proteins related to functional studies and myocardial energy metabolism were analyzed and evaluated using techniques such as Polymerase Chain Re-action (PCR), Western blotting, double luciferase biochemical techniques, flow cytometry assay, etc. It was discovered that exosomes ameliorated cardiomyocyte injury t by delivery of miR-132-3p.This process reduced the expression of Phosphatase and tensin homolog (PTEN) mRNA and protein, enhanced the expression of phosphorylated protein kinase (pAKT), regulated the insulin signaling pathway, facilitated intracellular Glucose transporter 4 (GLUT4) protein membrane translocation, and enhanced glucose uptake and Adenosine Triphosphate (ATP) production. This study confirmed, for the first time, that MSC-EXO can provide myocardial protection in the early stages of MIRI through miR-132/PTEN/AKT pathway. This research establishes a theoretical and experimental foundation for the clinical application of MSC-derived exosomes.

Anti-liver fibrotic effects of small extracellular vesicle microRNAs from human umbilical cord-derived mesenchymal stem cells and their differentiated hepatocyte-like cells

OBJECTIVE

The aim of this study is to identify therapeutic cargos within mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEVs) for the treatment of liver fibrosis, a condition that poses significant health risks.

RESULTS

sEVs from human umbilical cord-derived MSCs (UCMSCs) and their differentiated hepatocyte-like cells (hpUCMSCs) were found to alleviate liver fibrosis in mouse models, reduce fibrogenic gene expression in the liver, and inhibit hepatic stellate cell (HSC) activation, a central driver of liver fibrosis, in vitro. Deep sequencing identified differentially abundant microRNAs (miRNAs) (high-abundance: 57, low-abundance: 22) in both UCMSC- and hpUCMSC-derived sEVs, compared to HeLa cell-derived sEVs, which lack anti-liver fibrotic activity. Functional enrichment analysis of the high-abundance sEV miRNA targets revealed their involvement in transcriptional regulation, apoptosis, and cancer-related pathways, all of which are linked to liver fibrosis and hepatocellular carcinoma. Notably, many of the top 10 most abundant miRNAs reduced pro-fibrotic marker levels in activated HSCs in vitro.

CONCLUSION

The therapeutic potential of the high-abundance miRNAs shared by UCMSC- and hpUCMSC-derived sEVs in treating liver fibrosis is highlighted.

The emerging role of mesenchymal stem cell-derived extracellular vesicles to ameliorate hippocampal NLRP3 inflammation induced by binge-like ethanol treatment in adolescence

JOURNAL/nrgr/04.03/01300535-202504000-00030/figure1/v/2024-07-06T104127Z/r/image-tiff Our previous studies have reported that activation of the NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3)-inflammasome complex in ethanol-treated astrocytes and chronic alcohol-fed mice could be associated with neuroinflammation and brain damage. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been shown to restore the neuroinflammatory response, along with myelin and synaptic structural alterations in the prefrontal cortex, and alleviate cognitive and memory dysfunctions induced by binge-like ethanol treatment in adolescent mice. Considering the therapeutic role of the molecules contained in mesenchymal stem cell-derived extracellular vesicles, the present study analyzed whether the administration of mesenchymal stem cell-derived extracellular vesicles isolated from adipose tissue, which inhibited the activation of the NLRP3 inflammasome, was capable of reducing hippocampal neuroinflammation in adolescent mice treated with binge drinking. We demonstrated that the administration of mesenchymal stem cell-derived extracellular vesicles ameliorated the activation of the hippocampal NLRP3 inflammasome complex and other NLRs inflammasomes (e.g., pyrin domain-containing 1, caspase recruitment domain-containing 4, and absent in melanoma 2, as well as the alterations in inflammatory genes (interleukin-1β, interleukin-18, inducible nitric oxide synthase, nuclear factor-kappa B, monocyte chemoattractant protein-1, and C-X3-C motif chemokine ligand 1) and miRNAs (miR-21a-5p, miR-146a-5p, and miR-141-5p) induced by binge-like ethanol treatment in adolescent mice. Bioinformatic analysis further revealed the involvement of miR-21a-5p and miR-146a-5p with inflammatory target genes and NOD-like receptor signaling pathways. Taken together, these findings provide novel evidence of the therapeutic potential of MSC-derived EVs to ameliorate the hippocampal neuroinflammatory response associated with NLRP3 inflammasome activation induced by binge drinking in adolescence.

Extracellular Vesicles Derived from Mesenchymal Stromal Cells Reduce Pseudomonas aeruginosa Lung Infection and Inflammation in Mice

The World Health Organization and the U.S. Centers for Disease Control and Prevention have reported that antibiotic resistant infections with Pseudomonas aeruginosa present a significant health risk world-wide. In the genetic disease Cystic Fibrosis (CF), chronic antibiotic resistant Pseudomonas lung infections and persistent inflammation remain the leading causes of morbidity and mortality. While highly effective modulator therapy (HEMT) dramatically improves lung function in CF, they fail to eradicate chronic infections or eliminate the associated hyperinflammatory state. Thus, there is an urgent need for innovative therapies that can simultaneously eliminate antibiotic resistant P. aeruginosa lung infection and the attendant hyperinflammatory lung environment. Mesenchymal stromal cell-derived extracellular vesicles (MSC EVs) represent a promising solution, offering potent anti-inflammatory, immunomodulatory, and antimicrobial properties while being safe and non-toxic. This study demonstrates using a CF mouse model of infection that MSC EVs reduce acute P. aeruginosa lung infection and inflammation. MSC EVs reduced Pseudomonas burden, immune cell infiltration, and pro-inflammatory cytokine levels. As the first investigation of MSC EVs in CF, this research underscores the dual effects of MSC EVs; mitigating inflammation and reducing bacterial burden. These findings mark an important advancement in antimicrobial therapy, addressing the unmet need for reducing antibiotic resistant infections and hyperinflammation for people with CF as well as the multitude of others with chronic, antibiotic resistant P. aeruginosa lung infections.

GRAPHICAL ABSTRACT

NEW AND NOTEWORTHY

This is the first study demonstrating the ability of Mesenchymal Stromal Cell Extracellular Vesicles (MSC EVs) to reduce Pseudomonas aeruginosa burden and inflammation in a CF mouse model of infection.

Immunomodulatory effects and clinical application of exosomes derived from mesenchymal stem cells

Exosomes (Exos) are extracellular vesicles secreted by cells and serve as crucial mediators of intercellular communication. They play a pivotal role in the pathogenesis and progression of various diseases and offer promising avenues for therapeutic interventions. Exos derived from mesenchymal stem cells (MSCs) have significant immunomodulatory properties. They effectively regulate immune responses by modulating both innate and adaptive immunity. These Exos can inhibit excessive inflammatory responses and promote tissue repair. Moreover, they participate in antigen presentation, which is essential for activating immune responses. The cargo of these Exos, including ligands, proteins, and microRNAs, can suppress T cell activity or enhance the population of immunosuppressive cells to dampen the immune response. By inhibiting lymphocyte proliferation, acting on macrophages, and increasing the population of regulatory T cells, these Exos contribute to maintaining immune and metabolic homeostasis. Furthermore, they can activate immune-related signaling pathways or serve as vehicles to deliver microRNAs and other bioactive substances to target tumor cells, which holds potential for immunotherapy applications. Given the immense therapeutic potential of MSC-derived Exos, this review comprehensively explores their mechanisms of immune regulation and therapeutic applications in areas such as infection control, tumor suppression, and autoimmune disease management. This article aims to provide valuable insights into the mechanisms behind the actions of MSC-derived Exos, offering theoretical references for their future clinical utilization as cell-free drug preparations.

Extracellular vesicle-bound S100A8/A9 is differentially expressed in septic shock and prompts acute lung injury

BACKGROUND

Sepsis is a common indirect insult leading to acute respiratory distress syndrome (ARDS). Circulating extracellular vesicles (EVs) have been reported to participate in the pathogenesis of sepsis. However, the alteration of EV-bound S100A8/A9 during septic shock, along with the role of S100A8/A9 in driving acute lung injury, remains unexplored.

METHODS

EVs were isolated from the plasma of patients upon admission with sepsis or septic shock, as well as from healthy controls. Levels of EV S100A8/A9 were assayed via ELISA. To examine the effects and underlying mechanisms of septic shock EVs in acute lung injury, these EVs were administered intratracheally into wild-type C57BL/6 mice or mice with a deficiency of advanced glycation end-products (RAGE). In addition, a mouse model of polymicrobial sepsis was introduced using cecal ligation and puncture (CLP).

RESULTS

Levels of EV S100A8/A9 were significantly elevated in patients with sepsis or septic shock compared to healthy controls. Receiver operating characteristic (ROC) analysis demonstrated that EV S100A8/A9 effectively distinguished between septic shock and sepsis and had predictive potential for the development of ARDS. Notably, the levels of S100A8/A9 in EVs and alveolar macrophages from CLP mice were significantly higher than those in sham mice. Intratracheal administration of septic shock EVs directly induced acute lung injury and M1 macrophage polarization in a lipopolysaccharide-independent manner. Septic shock EVs were efficiently taken up by alveolar macrophages in vivo, leading to a significant increase in S100A8/A9 levels, which was inhibited by preincubating the EVs with an S100A8/A9 neutralizing antibody. Additionally, mice with deficiency in RAGE, a receptor for S100A8/A9, were partially protected from acute lung injury induced by septic shock EVs. In vitro, septic shock EVs prompted a proinflammatory response in bone marrow-derived macrophages. This response was blocked by preincubating the EVs with the S100A8/A9 neutralizing antibody.

CONCLUSIONS

Our results suggested that EV S100A8/A9 has potential value in distinguishing septic shock from sepsis and predicting the development of ARDS. Septic shock EVs-induced lung injury is at least partially mediated through S100A8/A9-RAGE pathway, involving the activation of alveolar macrophages.

Exosomes derived from hypoxic mesenchymal stem cell ameliorate premature ovarian insufficiency by reducing mitochondrial oxidative stress

Cyclophosphamide (CTX) exposure causes premature ovarian insufficiency (POI). The therapeutic potential of exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs) is not fully understood, especially regarding whether hypoxic preconditioning enhances their efficacy in POI. In this study, exosomes were isolated and identified from hucMSCs (hucMSCs-Exos) under hypoxic (HExos) and normoxic (NExos) conditions. Cyclophosphamide (CTX) was used to develop the POI rat model, and NExos or HExos was injected into the tail vein to investigate its therapeutic effect on POI. In addition, CTX-treated KGN cell lines were used to investigate the effects of NExos and HExos on cell proliferation, apoptosis, oxidative stress and mitochondrial membrane potential.The results indicated that hucMSCs-Exos transplantation substantially improved body weight, ovarian weight coefficient, estrous cycles, ovarian morphology, ovulation count, and sex hormone levels in POI rats. Further, HExos showed a higher level of therapeutic efficiency than NExos. In vitro experiments demonstrated that NExos and HExos may be phagocytosed by KGN cell line, decrease cell apoptosis, and enhance cell growth. After NExos or HExos transplantation, the reactive oxygen species level was reduced, mitochondrial membrane potential enhanced, and the levels of mitochondrial oxidative stress-associated factors returned to their basal level. Notably, the improvement of oxidative stress by NExos or HExos was blocked by the SIRT3 selective inhibitor 3-TYP. In conclusion, hypoxia-induced hucMSCs-Exos protected the ovarian reserve against CXT-induced ovarian damage by rectifying mitochondrial malfunction via the SIRT3/PGC1-α pathway, establishing a solid basis for developing specific ovarian protection therapies.

Effects of Hydrogels on Mesenchymal Stem/Stromal Cells Paracrine Activity and Extracellular Vesicles Production

Mesenchymal stem/stromal cells (MSCs) are a valuable source of paracrine factors, as they have a remarkable secretory capacity, and there is a sizeable knowledge base to develop industrial and clinical production protocols. Promising cell-free approaches for tissue regeneration and immunomodulation are driving research towards secretome applications, among which extracellular vesicles (EVs) are steadily gaining attention. However, the manufacturing and application of EVs is limited by insufficient yields, knowledge gaps, and low standardization. Facing these limitations, hydrogels represent a versatile three-dimensional (3D) culture platform that can incorporate extracellular matrix (ECM) components to mimic the natural stem cell environment in vitro; via these niche-mimicking properties, hydrogels can regulate MSCs' morphology, adhesion, proliferation, differentiation and secretion capacities. However, the impact of the hydrogel's architectural, biochemical and biomechanical properties on the production of EVs remains poorly understood, as the field is still in its infancy and the interdependency of culture parameters compromises the comparability of the studies. Therefore, this review summarizes and discusses the reported effects of hydrogel encapsulation and culture on the secretion of MSC-EVs. Considering the effects of cell-material interactions on the overall paracrine activity of MSCs, we identify persistent challenges from low standardization and process control, and outline future paths of research, such as the synergic use of hydrogels and bioreactors to enhance MSC-EV generation.

Ultrasensitive Quantification of microRNA Copy Number in Individual Extracellular Vesicles Using DNA Tetrahedron-Based Single-Molecule Imaging

The ultrasensitive detection of microRNAs (miRNAs) in extracellular vesicles (EVs) can accurately reflect the progress and metastasis of miRNA-mediated intercellular communication, providing an unprecedented opportunity for liquid biopsy. However, due to the low abundance and high heterogeneity of miRNAs in EVs, the ultrasensitive quantification and establishment of a distribution model for miRNA within native EVs remain challenging. Here, we have developed a DNA tetrahedron-based single-molecule fluorescence imaging strategy to overcome this challenge. The internalization efficiency of the probe was as high as 70% without disrupting the native structure of EVs, and combined with single-molecule fluorescence imaging, we achieved in situ imaging analysis of single-copy miRNA in individual EVs without amplification for the first time. A new distribution model for miRNAs has been revealed by statistical analysis of the copy number of miRNAs in EVs across multiple cell lines, characterized by low occupancy and a heterogeneous distribution. More importantly, we found that drug resistance cancer cells promote an increase in the number of drug resistance-related miRNAs within EVs without a corresponding increase in the number of EVs secreted, providing new insights into the EV miRNA sorting mechanisms. We anticipate that this technology will rapidly advance miRNA-mediated intercellular communication based on EVs.

Mesenchymal stem cells-derived exosomes attenuate mouse non-heart-beating liver transplantation through Mir-17-5p-regulated Kupffer cell pyroptosis

BACKGROUND

Liver transplantation is the most effective treatment for end-stage liver disease. However, the shortage of donor livers has become a significant obstacle to the advancement of liver transplantation. Mesenchymal stem cells-derived exosomes (MSCs-Exo) have been extensively investigated in liver diseases. However, the underlying mechanisms of how they can protect organ donation after cardiac death (DCD) livers remain unclear.

METHODS

In this study, an arterialized mouse non-heart-beating (NHB) liver transplantation model was used to investigate the effect of MSCs-Exo on NHB liver transplantation. The survival rates, histology, pro-inflammatory cytokine and chemokine expression, and underlying mechanisms were investigated.

RESULTS

The infusion of MSCs-Exo reduced the injury to DCD liver graft tissue. In vitro and in vivo experiments demonstrated that MSCs-Exo could inhibit hydrogen peroxide-induced pyroptosis of Kupffer cells. We found that miR-17-5p was significantly abundant in MSCs-Exo, targeting and regulating the TXNIP expression. This action inhibited NLRP3-mediated pyroptosis of Kupffer cells through the classical Caspase1-dependent pathway, alleviating DCD liver graft injury.

CONCLUSION

Our study elucidated a protective role for MSCs-Exo in a NHB liver transplantation model. This mechanism provides a theoretical basis and new strategies for the clinical application of MSCs-Exo to improve liver graft quality and alleviate the organ shortage in liver transplantation.

Exosomal miR-25 from Mesenchymal stem cells inhibits T cells migration and Alleviates Type 1 diabetes mellitus by Targeting CXCR3 models

Mesenchymal stem cells (MSCs) have demonstrated promising therapeutic potential in the treatment of type 1 diabetes mellitus (T1DM); however, the underlying mechanism remains unclear. The primary pathological mechanism of T1DM involves activated T cells infiltrating the pancreas, leading to islet inflammation and the destruction of β-cells. However, the question of whether exosomes derived from MSCs can suppress the migration of T cells to the pancreas in the context of T1DM remains unresolved. In this study, we observed that miR-25 was highly expressed in MSCs exosomes and associated with signaling pathways related to cell migration. In vitro assay, we synthesized a miR-25 mimic and transiently transfected it into activated T cells, which revealed that miR-25 can effectively reduce the expression of CXCR3. Additionally, according to the in vivo T1DM mouse model, we found that there was a significant increase in miR-25 levels in T1DM mice treated with MSCs and the number of T cells decreased. Overall, our findings suggest that MSCs exosomes containing miR-25 can impede the infiltration of activated T cells into the pancreas in T1DM by repressing CXCR3 expression in these cells.

Profiling the extracellular vesicles of two human placenta-derived mesenchymal stromal cell populations

Increasing evidence shows extracellular vesicles (EVs) are primarily responsible for the beneficial effects of cell-based therapies. EVs derived from mesenchymal stromal cells (MSCs) show promise as a source of EVs for cell-free therapies. The human placental fetal-maternal interface is a rich and abundant source of MSCs from which EVs can be isolated. This study focusses on chorionic MSCs (CMSC) located on the fetal aspect of the interface and decidual MSCs (DMSC) on the maternal aspect. This study used Ligand-based Exosome Affinity Purification (LEAP) chromatography to isolate EVs from well-characterized placental hTERT-transduced CMSC29 and DMSC23 cell lines, which retain many important stem cell-like properties of primary CMSC and DMSC, respectively. After initial biophysical characterization of the EVs isolated from each cell line, the biological activities and the protein, lipid and small RNA contents of CMSC29-EVs and DMSC23-EVs were compared and assessed. LEAP-purified EVs from both sources were validated at the biophysical level by Spectradyne, Cryo-Transmission Electron Microscopy (Cryo-TEM), and Western blot analysis. EVs from each type were labelled with the live cell stain PKH26 and their in vitro uptake and internalization by human dermal fibroblast cells was assessed, as well as their phosphorylation of the protein kinase B/AKT (AKT) pathway. The protein and lipid contents were analyzed by mass spectrometry and the nucleic acid content by RNA sequencing (RNA-seq). Lastly, the biological activities of the EVs were evaluated in a BioMAP® Diversity PLUS® screen system across a panel of 12 human primary cell-based systems and in vitro cell proliferation. EVs isolated from both DMSC23 and CMSC29 significantly increased proliferation of fibroblasts and showed phosphorylation of the AKT pathway. Protein mass spectrometry analysis identified a large number of proteins including cell surface receptors, cytokines, chemokines, matrix molecules and enzymes in both EV types. Lipidomic analysis identified species including phosphatidylcholine, triacylglycerides and diacylglycerides in both DMSC23 and CMSC29-derived EVs. There were some significant differences in identified microRNAs (miRNAs) between the two EV types. The top differentially expressed miRNAs between the two EV types show pathways association with matrix interaction, transcriptional regulation, proliferation, cellular protein modification processes, and vasculogenesis. Differences were also detected between DMSC23- and CMSC29-EVs in the biological activity they displayed in the BioMAP® Diversity PLUS® screen.

Extracellular Vesicles as Tools for Crossing the Blood-Brain Barrier to Treat Lysosomal Storage Diseases

Extracellular vesicles (EVs) are nanosized, membrane-bound structures that have emerged as promising tools for drug delivery, especially in the treatment of lysosomal storage disorders (LSDs) with central nervous system (CNS) involvement. This review highlights the unique properties of EVs, such as their biocompatibility, capacity to cross the blood-brain barrier (BBB), and potential for therapeutic cargo loading, including that of enzymes and genetic material. Current therapies for LSDs, like enzyme replacement therapy (ERT), often fail to address neurological symptoms due to their inability to cross the BBB. EVs offer a viable alternative, allowing for targeted delivery to the CNS and improving therapeutic outcomes. We discuss recent advancements in the engineering and modification of EVs to enhance targeting, circulation time and cargo stability, and provide a detailed overview of their application in LSDs, such as Gaucher and Fabry diseases, and Sanfilippo syndrome. Despite their potential, challenges remain in scaling production, ensuring isolation purity, and meeting regulatory requirements. Future developments will focus on overcoming these barriers, paving the way for the clinical translation of EV-based therapies in LSDs and other CNS disorders.

Mesenchymal Stem Cell-Derived Extracellular Vesicles for Regenerative Applications and Radiotherapy

Tissue repair is an extremely crucial part of clinical treatment. During the course of disease treatment, surgery, chemotherapy, and radiotherapy cause tissue damage. On the other hand, Normal tissue from accidental or therapeutic exposure to high-dose radiation can cause severe tissue damage. There is an urgent need for developing medical countermeasures against radiation injury for tissue repair. Tissue repair involves the regeneration, proliferation, differentiation, and migration of tissue cells; imbalance of local tissue homeostasis, progressive chronic inflammation; decreased cell activity and stem cell function; and wound healing. Although many clinical treatments are currently available for tissue repair, they are expensive. The long recovery time and some unavoidable complications such as cell damage and the inflammatory reaction caused by radiotherapy have led to unsatisfactory results. Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have similar tissue repair functions as MSCs. In tissue damage, EVs can be used as an alternative to stem cell therapy, thereby avoiding related complications such as immunological rejection. EVs play a major role in regulating tissue damage, anti-inflammation, pro-proliferation, and immune response, thus providing a diversified and efficient solution for the repair of disease- and radiotherapy-induced tissue damage. This article reviews the research progress of mesenchymal stem cell-derived EVs in promoting the repair of tissue including heart, lung, liver, intestine, skin, blood system, central nervous system, and tissue damage caused by radiotherapy, thereby aiming to offer new directions and ideas for the radiotherapy and regenerative applications.

Cell-free osteoarthritis treatment with dual-engineered chondrocyte-targeted extracellular vesicles derived from mechanical loading primed mesenchymal stem cells

Osteoarthritis (OA) is an age-related chronic inflammatory disease, predominantly characterized by chondrocyte senescence and extracellular matrix (ECM) degradation. Although mesenchymal stem cells (MSCs) derived extracellular vesicles (EVs) are promising for promoting cartilage regeneration, their clinical application is limited by inconsistent therapeutic effects and insufficient targeting capabilities. Mechanical loading shows potential to optimize MSC-EVs for OA treatment, while the underlying mechanism is not clear. In this study, EVs derived from mechanical loading-primed MSCs (ML-EVs) demonstrate prominent efficacy in maintaining ECM homeostasis and relieving chondrocyte senescence, thereby mitigating OA. Subsequent miRNA sequencing reveals that ML-EVs exert their effects by delivering miR-27b-3p, which targets ROR1 mRNA in chondrocytes and suppresses downstream NF-κB pathways. By modulating the ROR1/NF-κB axis, miR-27b-3p effectively restrains ECM degradation and chondrocyte senescence. To optimize therapeutic efficacy of EVs, miR-27b-3p is overexpressed within EVs (miROE-EVs), and a chondrocyte-targeted peptide (CTP) is conjugated to their surface, thereby constructing dual-engineered chondrocyte-targeted EVs (CTP/miROE-EVs). CTP/miROE-EVs exhibit excellent ability to specifically target cartilage and ameliorate OA pathology. In conclusion, this study underscores the critical role of mechanical loading in augmenting effectiveness of EVs in mitigating OA and introduces dual-engineered EVs that specifically target chondrocytes, providing a promising therapeutic strategy for OA.

Can miRNAs in MSCs-EVs Offer a Potential Treatment for Hypoxic-ischemic Encephalopathy?

Neonatal hypoxic-ischemic encephalopathy (HIE) is a critical condition resulting from impaired oxygen and blood flow to the brain during birth, leading to neuroinflammation, neuronal apoptosis, and long-term neurological deficits. Despite the use of therapeutic hypothermia, current treatments remain inadequate in fully preventing brain damage. Recent advances in mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) offer a novel, cell-free therapeutic approach, as these EVs can cross the blood-brain barrier (BBB) and deliver functional microRNAs (miRNAs) to modulate key pathways involved in inflammation and neuroprotection. This review examines how specific miRNAs encapsulated in MSC-EVs-including miR-21, miR-124, miR-146, and the miR-17-92 cluster-target the complex inflammatory responses that drive HIE pathology. By modulating pathways such as NF-κB, STAT3, and PI3K/Akt, these miRNAs influence neuroinflammatory processes, reduce neuronal apoptosis, and promote tissue repair. The aim is to assess the therapeutic potential of miRNA-loaded MSC-EVs in mitigating inflammation and neuronal damage, thus addressing the limitations of current therapies like therapeutic hypothermia.

Recent advances in the role of mesenchymal stem cells as modulators in autoinflammatory diseases

Mesenchymal stem cells (MSCs), recognized for their self-renewal and multi-lineage differentiation capabilities, have garnered considerable wide attention since their discovery in bone marrow. Recent studies have underscored the potential of MSCs in immune regulation, particularly in the context of autoimmune diseases, which arise from immune system imbalances and necessitate long-term treatment. Traditional immunosuppressive drugs, while effective, can lead to drug tolerance and adverse effects, including a heightened risk of infections and malignancies. Consequently, adjuvant therapy incorporating MSCs has emerged as a promising new treatment strategy, leveraging their immunomodulatory properties. This paper reviews the immunomodulatory mechanisms of MSCs and their application in autoimmune diseases, highlighting their potential to regulate immune responses and reduce inflammation. The immunomodulatory mechanisms of MSCs are primarily mediated through direct cell contact and paracrine activity with immune cells. This review lays the groundwork for the broader clinical application of MSCs in the future and underscores their significant scientific value and application prospects. Further research is expected to enhance the efficacy and safety of MSCs-based treatments for autoimmune diseases.

Roles of extracellular vesicles from mesenchymal stem cells in regeneration

Mesenchymal stem cells (MSCs) are highly valued in regenerative medicine due to their ability to self-renew and differentiate into various cell types. Their therapeutic benefits are primarily due to their paracrine effects, in particular through extracellular vesicles (EVs), which are related to intercellular communication. Recent advances in EV production and extraction technologies highlight the potential of MSC-derived EVs (MSC-EVs) in tissue engineering and regenerative medicine. MSC-EVs offer several advantages over traditional cell therapies, including reduced toxicity and immunogenicity compared with whole MSCs. EVs carrying functional molecules such as growth factors, cytokines, and miRNAs play beneficial roles in tissue repair, fibrosis treatment, and scar prevention by promoting angiogenesis, skin cell migration, proliferation, extracellular matrix remodeling, and reducing inflammation. Despite the potential of MSC-EVs, there are several limitations to their use, including variability in quality, the need for standardized methods, low yield, and concerns about the composition of EVs and the potential risks. Overall, MSC-EVs are a promising alternative to cell-based therapies, and ongoing studies aim to understand their actions and optimize their use for better clinical outcomes in wound healing and skin regeneration.

Electrostatic Gelatin Nanoparticles for Biotherapeutic Delivery

Biological agents such as extracellular vesicles (EVs) and growth factors, when administered in vivo, often face rapid clearance, limiting their therapeutic potential. To address this challenge and enhance their efficacy, we propose the electrostatic conjugation and sequestration of these agents into gelatin-based biomaterials. In this study, gelatin nanoparticles (GNPs) were synthesized via the nanoprecipitation method, with adjustments to the pH of the gelatin solution (4.0 or 10.0) to introduce either a positive or negative charge to the nanoparticles. The GNPs were characterized using dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Transmission electron microscopy (TEM) imaging. Both positively and negatively charged GNPs were confirmed to be endotoxin-free and non-cytotoxic. Mesenchymal stem cell (MSC)-derived EVs exhibited characteristic surface markers and a notable negative charge. Zeta potential measurements validated the electrostatic conjugation of MSC-EVs with positively charged GNPs. Utilizing a transwell culture system, we evaluated the impact of EV-GNP conjugates encapsulated within a gelatin hydrogel on macrophage secretory activity. The results demonstrated the bioactivity of EV-GNP conjugates and their synergistic effect on macrophage secretome over five days of culture. In summary, these findings demonstrate the efficacy of electrostatically coupled biotherapeutics with biomaterials for tissue regeneration applications.

Enhanced spinal cord repair using bioengineered induced pluripotent stem cell-derived exosomes loaded with miRNA

BACKGROUND

A spinal cord injury (SCI) can result in severe impairment and fatality as well as significant motor and sensory abnormalities. Exosomes produced from IPSCs have demonstrated therapeutic promise for accelerating spinal cord injury recovery, according to a recent study.

OBJECTIVE

This study aims to develop engineered IPSCs-derived exosomes (iPSCs-Exo) capable of targeting and supporting neurons, and to assess their therapeutic potential in accelerating recovery from spinal cord injury (SCI).

METHODS

iPSCs-Exo were characterized using Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA), and western blot. To enhance neuronal targeting, iPSCs-Exo were bioengineered, and their uptake by neurons was visualized using PKH26 labeling and fluorescence microscopy. In vitro, the anti-inflammatory effects of miRNA-loaded engineered iPSCs-Exo were evaluated by exposing neurons to LPS and IFN-γ. In vivo, biodistribution of engineered iPSC-Exo was monitored using a vivo imaging system. The therapeutic efficacy of miRNA-loaded engineered iPSC-Exo in a SCI mouse model was assessed by Basso Mouse Scale (BMS) scores, H&E, and Luxol Fast Blue (LFB) staining.

RESULTS

The results showed that engineered iPSC-Exo loaded with miRNA promoted the spinal cord injure recovery. Thorough safety assessments using H&E staining on major organs revealed no evidence of systemic toxicity, with normal organ histology and biochemistry profiles following engineered iPSC-Exo administration.

CONCLUSION

These results suggest that modified iPSC-derived exosomes loaded with miRNA have great potential as a cutting-edge therapeutic approach to improve spinal cord injury recovery. The observed negligible systemic toxicity further underscores their potential safety and efficacy in clinical applications.

Comparison of Autologous and Allogeneic Adipose-Derived Stem Cells in Kidney Transplantation: Immunological Considerations and Therapeutic Efficacy

Regenerative medicine shows significant potential in treating kidney diseases through the application of various types of stem and progenitor cells, including mesenchymal stem cells (MSCs), renal stem/progenitor cells, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs). Stem cells possess the unique ability to repair injured organs and improve impaired functions, making them a key element in the research of therapies for kidney tissue repair and organ regeneration. In kidney transplantation, reperfusion injury can cause tissue destruction, leading to an initially low glomerular filtration rate and long-term impact on function by creating irreversible interstitial fibrosis. MSCs have proven useful in repairing early tissue injury in animal models of kidney, lung, heart, and intestine transplantation. The use of stem cell therapies in solid organ transplantation raises the question of whether autologous or allogeneic cells should be preferred. Adipose-derived stem cells (ASCs), characterized by the lack of HLA Class II molecules and low expression of HLA Class I and co-stimulatory signals, are considered immune-privileged. However, the actual risk of graft rejection associated with allogeneic ASCs remains unclear. It has been demonstrated that donor-derived ASCs can promote the development of Treg cells in vitro, and some degree of tolerance induction has been observed in vivo. Nevertheless, a study comparing the efficacy of autologous and allogeneic ASCs in a rat model with a total MHC mismatch for kidney transplantation showed that donor-derived administration of ASCs did not improve the grafts' survival and was associated with increased mortality through an immunologically mediated mechanism. Given the lack of data, autologous ASCs appear to be a safer option in this research context. The aim of this review was to examine the differences between autologous and allogeneic ASCs in the context of their application in kidney transplantation therapies, considering potential immune reactions and therapeutic efficacy. Some have argued that ASCs harvested from end-stage renal disease (ESRD) patients may have lower regenerative potential due to the toxic effects of uremia, potentially limiting their use in transplantation settings. However, evidence suggests that the beneficial properties of ASCs are not affected by uremia or dialysis. Indeed, some investigators have demonstrated that ASCs harvested from chronic kidney disease (CKD) patients exhibit normal characteristics and function, maintaining consistent proliferative capacity and genetic stability over time, even after prolonged exposure to uremic serum Furthermore, no differences were observed in the response of ASCs to immune activation or their inhibitory effect on the proliferation of alloantigen-activated peripheral blood mononuclear cells between patients with normal or impaired renal function. This review presents the current achievements in stem cell research aimed at treating kidney diseases, highlighting significant progress and ongoing efforts in the development of stem cell-based therapies. Despite the encouraging results, further research is needed to overcome the current limitations and fully realize the potential of these innovative treatments. Advances in this field are crucial for developing effective therapies that can address the complex challenges associated with kidney damage and failure.

Advancements in diabetic foot ulcer research: Focus on mesenchymal stem cells and their exosomes

Diabetes represents a widely acknowledged global public health concern. Diabetic foot ulcer (DFU) stands as one of the most severe complications of diabetes, its occurrence imposing a substantial economic burden on patients, profoundly impacting their quality of life. Despite the deepening comprehension regarding the pathophysiology and cellular as well as molecular responses of DFU, the current therapeutic arsenal falls short of efficacy, failing to offer a comprehensive remedy for deep-seated chronic wounds and microvascular occlusions. Conventional treatments merely afford symptomatic alleviation or retard the disease's advancement, devoid of the capacity to effectuate further restitution of compromised vasculature and nerves. An escalating body of research underscores the prominence of mesenchymal stem cells (MSCs) owing to their paracrine attributes and anti-inflammatory prowess, rendering them a focal point in the realm of chronic wound healing. Presently, MSCs have been validated as a highly promising cellular therapeutic approach for DFU, capable of effectuating cellular repair, epithelialization, granulation tissue formation, and neovascularization by means of targeted differentiation, angiogenesis promotion, immunomodulation, and paracrine activities, thereby fostering wound healing. The secretome of MSCs comprises cytokines, growth factors, chemokines, alongside exosomes harboring mRNA, proteins, and microRNAs, possessing immunomodulatory and regenerative properties. The present study provides a systematic exposition on the etiology of DFU and elucidates the intricate molecular mechanisms and diverse functionalities of MSCs in the context of DFU treatment, thereby furnishing pioneering perspectives aimed at harnessing the therapeutic potential of MSCs for DFU management and advancing wound healing processes.

Resveratrol reinforces the therapeutic effect of mesenchymal stem cell (MSC)-derived exosomes against renal ischemia‒reperfusion injury (RIRI)-associated fibrosis by suppressing TGF-β-induced epithelial-mesenchymal transition

Resveratrol (RSV) has been shown to prevent epithelial-mesenchymal transition (EMT) in different diseases by modulating several signaling pathways, and RSV can prevent EMT by modulating the signaling of the TGF-β/Smad axis. In the development of renal ischemia‒reperfusion injury (RIRI), RSV and MSC-derived exosomes could ameliorate RIRI via different signaling pathways. In this study, we aimed to investigate the effect of RSV plus MSC-derived exosomes on the prognosis of RIRI. Quantitative real-time polymerase chain reaction (PCR) was performed to measure the expression of E-CAD, SMA, COL10A1, VMT and MMP-7 mRNA in TCMK-1 cells and mice under various conditions. HE and Masson staining were used to evaluate kidney injury and fibrosis in mice under various conditions. RSV effectively maintained the TGF-β- and AA-induced upregulation of E-CAD, SMA, COL10A1, VMT and MMP-7 mRNA expression in TCMK-1 cells. Moreover, MSC-derived exosomes effectively reinforced the effect of RSV on reducing the TGF-β- and AA-induced upregulation of E-CAD, SMA, COL10A1, VMT and MMP-7 mRNA expression in TCMK-1 cells. Furthermore, MSC-derived exosomes enhanced the capability of RSV to maintain the RIRI-induced increases in Cr and BUN, as well as the upregulation of E-CAD, SMA, COL10A1, VMT and MMP-7 mRNA expression in mice. In addition, MSC-derived exosomes enhanced the capability of RSV to decrease RIRI-induced kidney injury and fibrosis in mice. Our findings showed that the administration of MSC-derived exosomes and RSV could suppress the TGF-β-induced epithelial-mesenchymal transition. This suppressive effect was promoted by the coadministration of MSC-derived exosomes and RSV.

The Role of Exosomes from Mesenchymal Stem Cells in Spinal Cord Injury: A Systematic Review

Spinal cord injury (SCI) is a serious nervous system disease that usually leads to the impairment of the motor, sensory, and autonomic nervous functions of the spinal cord, and it places a heavy burden on families and healthcare systems every year. Due to the complex pathophysiological mechanism of SCI and the poor ability of neurons to regenerate, the current treatment scheme has very limited effects on the recovery of spinal cord function. In addition, due to their unique advantages, exosomes can be used as carriers for cargo transport. In recent years, some studies have confirmed that treatment with mesenchymal stem cells (MSCs) can promote the recovery of SCI nerve function. The therapeutic effect of MSCs is mainly related to exosomes secreted by MSCs, and exosomes may have great potential in SCI therapy. In this review, we summarized the repair mechanism of mesenchymal stem cells-derived exosomes (MSCs-Exos) in SCI treatment and discussed the microRNAs related to SCI treatment based on MSCs-Exos and their mechanism of action, which is helpful to further understand the role of exosomes in SCI.

Influence of inflammation on the expression of microRNA-140 in extracellular vesicles from 2D and 3D culture models of synovial-membrane-derived stem cells

Background

In osteoarthritis (OA), articular homeostasis is regulated by microRNA-140 that inhibits ADAMTS-5, an enzyme that cleaves aggrecan and stimulates the synthesis of other inflammatory mediators. This study aims to evaluate the expression of microRNA-140 in extracellular vesicles (EVs) derived from equine synovial-membrane-derived mesenchymal stem cells (eqSMMSCs) cultured in monolayer (2D) and three-dimensional (3D) culture models under an in vitro inflammatory environment.

Methods

Four experimental groups of eqSMMSC cultures were defined for isolation of the EVs. The 2D and 3D control groups were cultured in a conventional cell culture medium, while the 2D-OA and 3D-OA treatment groups were exposed to an OA-like medium containing IL-1β and TNFα. The culture media samples were collected at 24 h, 72 h, and 120 h time points for EV isolation and characterization using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Reverse transcription quantitative polymerase chain reaction was employed to assess the expressions of microRNA-140 in both the cells and EVs. All statistical analyses were conducted at the 5% significance level.

Results

Encapsulation of the eqSMMSCs protected the cells from the inflammatory media compared to the monolayer cultures. EVs were found in higher concentrations in the 3D-OA cultures. Additionally, higher expressions of microRNA-140 were observed in the cells of the 3D-OA group at 24 and 72 h, whereas microRNA-140 expressions in the EVs were higher in the 3D group at 72 h and in the 2D-OA group at 120 h (p < 0.001). However, the 3D-OA culture showed higher expression of the mRNA Adamts5 in the EVs at 120 h.

Conclusion

The responses of the eqSMMSCs to inflammatory stimuli involve intracellular expression of microRNA-140 and its subsequent transportation via the EVs, with quicker responses observed in the 3D than 2D cultures. This study sheds light on the behaviors of stem cells in restoring homeostasis in osteoarthritic joints.

Biopotency and surrogate assays to validate the immunomodulatory potency of extracellular vesicles derived from mesenchymal stem/stromal cells for the treatment of experimental autoimmune uveitis

Extracellular vesicles (EVs) derived from mesenchymal stem/stromal cells (MSCs) have been recognized as promising cytotherapeutics due to their demonstrated immunomodulatory effects in various preclinical models. The immunomodulatory capabilities of EVs stem from the proteins and genetic materials they carry from parent cells, but the cargo contents of EVs are significantly influenced by MSC tissues and donors, cellular age and culture conditions, resulting in functional variations. However, there are no surrogate assays available to validate the immunomodulatory potency of MSC-EVs before in vivo administration. In previous work, we discovered that microcarrier culture conditions enhance the immunomodulatory function of MSC-EVs, as well as the levels of immunosuppressive molecules such as TGF-β1 and let-7b in MSC-EVs. Building on these findings, we investigated whether TGF-β1 levels in MSC-EVs could serve as a surrogate biomarker for predicting their potency in vivo. Our studies revealed a strong correlation between TGF-β1 and let-7b levels in MSC-EVs, as well as their capacity to suppress IFN-γ secretion in stimulated splenocytes, establishing biopotency and surrogate assays for MSC-EVs. Subsequently, we validated MSC-EVs generated from monolayer cultures (ML-EVs) or microcarrier cultures (MC-EVs) using murine models of experimental autoimmune uveoretinitis (EAU) and additional in vitro assays reflecting the Mode of Action of MSC-EVs in vivo. Our findings demonstrated that MC-EVs carrying high levels of TGF-β1 exhibited greater efficacy than ML-EVs in halting disease progression in mice with EAU as well as inducing apoptosis and inhibiting the chemotaxis of retina-reactive T cells. Additionally, MSC-EVs suppressed the MAPK/ERK pathway in activated T cells, with treatment using TGF-β1 or let-7b showing similar effects on the MAPK/ERK pathway. Collectively, our data suggest that MSC-EVs directly inhibit the infiltration of retina-reactive T cells toward the eyes, thereby halting the disease progression in EAU mice, and their immunomodulatory potency in vivo can be predicted by their TGF-β1 levels.

Exosomes from SHED-MSC regulate polarization and stress oxidative indexes in THP-1 derived M1 macrophages

OBJECTIVE

The inhibition of M1 macrophages may be interesting for targeted therapy with mesenchymal stem cell-derived Exosomes (MSC-EXOs). This study aimed to investigate the stem cells of human exfoliated deciduous teeth-derived EXOs (SHED-MSC-EXOs) effect on regulating the pro- and anti-oxidant indexes and inhibiting M1 macrophage polarization. Besides, an in-silico analysis of SHED-MSC-EXO miRNAs as the highest frequency of small RNAs in the exosomes was performed to discover the possible mechanism.

METHODS

The flow cytometry analysis of CD80 and CD86 as M1-specific markers confirmed the polarization of macrophages derived from THP-1 cells. After exosome isolation, characterization, and internalization, THP-1-derived M1 macrophages were treated with SHED-MSC-EXOs. M1-specific markers and pro- and anti-oxidant indexes were evaluated. For in-silico analysis of SHED-MSC-EXOs miRNAs, initial miRNA array data of SHED-EXOs is collected from GEO, and the interaction of the miRNAs in M1 macrophage polarization (M1P), mitochondrial oxidative stress (MOS) and LPS-induced oxidative stress (LOS) were analyzed by miRWalk 3.0 server. Outcomes were filtered by 75th percentile signal intensity, score cut-off ≥0.95, minimum free energy (MEF)≤ -20 kcal/mol, and seed = 1.

RESULTS

It shows a decrease in the expression of CD80 and CD81, a reduction in pro-oxidant indicators, and an increase in the anti-oxidant indexes (P < 0.05). Computational analysis showed that eight microRNAs of SHED-MSC-EXO miRNAs can bind to and interfere with the expression of candidate genes in the M1P, MOS, and LOS pathways simultaneously.

CONCLUSION

SHED-MSCs-EXOs can be utilized to treat conditions related to M1 macrophage-induced diseases (M1IDs) due to their unique physical properties and ability to penetrate target cells easily.

Mesenchymal stem cell-derived exosomes: Characteristics and applications in disease pathology and management

Mesenchymal stem cells (MSCs) possess a role in tissue regeneration and homeostasis because of inherent immunomodulatory capacity and the production of factors that encourage healing. There is substantial evidence that MSCs' therapeutic efficacy is primarily determined by their paracrine function including in cancers. Extracellular vesicles (EVs) are basic paracrine effectors of MSCs that reside in numerous bodily fluids and cell homogenates and play an important role in bidirectional communication. MSC-derived EVs (MSC-EVs) offer a wide range of potential therapeutic uses that exceed cell treatment, while maintaining protocell function and having less immunogenicity. We describe characteristics and isolation methods of MSC-EVs, and focus on their therapeutic potential describing its roles in tissue repair, anti-fibrosis, and cancer with an emphasis on the molecular mechanism and immune modulation and clinical trials. We also explain current understanding and challenges in the clinical applications of MSC-EVs as a cell free therapy.

Modulation of experimental acute lung injury by exosomal miR-7704 from mesenchymal stromal cells acts through M2 macrophage polarization

Acute lung injury (ALI) is a life-threatening condition with limited treatment options. The pathogenesis of ALI involves macrophage-mediated disruption and subsequent repair of the alveolar barriers, which ultimately results in lung damage and regeneration, highlighting the pivotal role of macrophage polarization in ALI. Although exosomes derived from mesenchymal stromal cells have been established as influential modulators of macrophage polarization, the specific role of exosomal microRNAs (miRNAs) remains underexplored. This study aimed to elucidate the role of specific exosomal miRNAs in driving macrophage polarization, thereby providing a reference for developing novel therapeutic interventions for ALI. We found that miR-7704 is the most abundant and efficacious miRNA for promoting the switch to the M2 phenotype in macrophages. Mechanistically, we determined that miR-7704 stimulates M2 polarization by inhibiting the MyD88/STAT1 signaling pathway. Notably, intra-tracheal delivery of miR-7704 alone in a lipopolysaccharide-induced murine ALI model significantly drove M2 polarization in lung macrophages and remarkably restored pulmonary function, thus increasing survival. Our findings highlight miR-7704 as a valuable tool for treating ALI by driving the beneficial M2 polarization of macrophages. Our findings pave the way for deeper exploration into the therapeutic potential of exosomal miRNAs in inflammatory lung diseases.

Preemptive administration of mesenchymal stem cells-derived conditioned medium can attenuate the development of neuropathic pain in rats via downregulation of proinflammatory cytokines

Neuropathic pain (NP) is a chronic condition characterized by persistent pain following nerve injury. It is a challenging clinical problem to manage due to limited treatment options. Mesenchymal stem cells (MSCs)-derived conditioned medium (CM) is a cell-free product that contains the secretome of MSCs and has been shown to have therapeutic potential in various inflammatory and degenerative disorders. Several animal studies have examined the antinociceptive effects of MSCs-CM on established neuropathic pain, but none have investigated the early prevention of neuropathic pain using MSCs-CM. Therefore, in this study, we tested whether preemptive administration of MSCs-CM could attenuate the development of NP in rats. To this end, NP was induced in Wistar rats using a chronic constriction injury (CCI) model (day 0), and then the animals were divided into four groups: Sham, CCI, CCI-Dulbecco's Modified Eagle Medium (DMEM), and CCI-CM. The CCI-CM group received 1 ml intraperitoneal administration of MSCs-CM on days - 1, 1, and 2, while the Sham, CCI, and CCI-DMEM groups received vehicle only (normal saline or DMEM). Mechanical withdrawal threshold and thermal withdrawal latency were assessed to evaluate pain sensitivities. In addition, the expression levels of proinflammatory cytokines (TNF-α and IL-1β) in the spinal cord tissues were measured using quantitative real-time PCR (qRT-PCR). The results demonstrated that preemptive treatment with MSCs-CM can significantly attenuate the development of NP, as evidenced by improved mechanical withdrawal threshold and thermal withdrawal latency in the CCI-CM group compared to the CCI and CCI-DMEM groups. Furthermore, the relative gene expression of proinflammatory cytokines TNF-α and IL-1β were significantly decreased in the spinal cord tissues of the CCI-CM group compared to the control groups. These findings suggest that preemptive administration of MSCs-CM can attenuate the development of NP in rats, partly due to the downregulation of proinflammatory cytokines.

Regulation of Oxygen Tension as a Strategy to Control Chondrocytic Phenotype for Cartilage Tissue Engineering and Regeneration

Cartilage defects and osteoarthritis are health problems which are major burdens on health care systems globally, especially in aging populations. Cartilage is a vulnerable tissue, which generally faces a progressive degenerative process when injured. This makes it the 11th most common cause of global disability. Conservative methods are used to treat the initial phases of the illness, while orthopedic management is the method used for more progressed phases. These include, for instance, arthroscopic shaving, microfracturing and mosaicplasty, and joint replacement as the final treatment. Cell-based implantation methods have also been developed. Despite reports of successful treatments, they often suffer from the non-optimal nature of chondrocyte phenotype in the repair tissue. Thus, improved strategies to control the phenotype of the regenerating cells are needed. Avascular tissue cartilage relies on diffusion for nutrients acquisition and the removal of metabolic waste products. A low oxygen content is also present in cartilage, and the chondrocytes are, in fact, well adapted to it. Therefore, this raises an idea that the regulation of oxygen tension could be a strategy to control the chondrocyte phenotype expression, important in cartilage tissue for regenerative purposes. This narrative review discusses the aspects related to oxygen tension in the metabolism and regulation of articular and growth plate chondrocytes and progenitor cell phenotypes, and the role of some microenvironmental factors as regulators of chondrocytes.

Regulation of inflammation during wound healing: the function of mesenchymal stem cells and strategies for therapeutic enhancement

A wound takes a long time to heal and involves several steps. Following tissue injury, inflammation is the primary cause of tissue regeneration and repair processes. As a result, the pathophysiological processes involving skin damage, healing, and remodeling depend critically on the control of inflammation. The fact that it is a feasible target for improving the prognosis of wound healing has lately become clear. Mesenchymal stem cells (MSCs) are an innovative and effective therapeutic option for wound healing due to their immunomodulatory and paracrine properties. By controlling the inflammatory milieu of wounds through immunomodulation, transplanted MSCs have been shown to speed up the healing process. In addition to other immunomodulatory mechanisms, including handling neutrophil activity and modifying macrophage polarization, there may be modifications to the activation of T cells, natural killer (NK) cells, and dendritic cells (DCs). Furthermore, several studies have shown that pretreating MSCs improves their ability to modulate immunity. In this review, we summarize the existing knowledge about how MSCs influence local inflammation in wounds by influencing immunity to facilitate the healing process. We also provide an overview of MSCs optimizing techniques when used to treat wounds.

Mesenchymal stromal cell derived extracellular vesicles as a therapeutic tool: immune regulation, MSC priming, and applications to SLE

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a dysfunction of the immune system. Mesenchymal stromal cell (MSCs) derived extracellular vesicles (EVs) are nanometer-sized particles carrying a diverse range of bioactive molecules, such as proteins, miRNAs, and lipids. Despite the methodological disparities, recent works on MSC-EVs have highlighted their broad immunosuppressive effect, thus driving forwards the potential of MSC-EVs in the treatment of chronic diseases. Nonetheless, their mechanism of action is still unclear, and better understanding is needed for clinical application. Therefore, we describe in this review the diverse range of bioactive molecules mediating their immunomodulatory effect, the techniques and possibilities for enhancing their immune activity, and finally the potential application to SLE.

Induced pluripotent stem cell-derived extracellular vesicles enriched with miR-126 induce proangiogenic properties and promote repair of ischemic tissue

Emerging evidence suggests that stem cell-derived extracellular vesicles (EVs) may induce pro-regenerative effects in ischemic tissues by delivering bioactive molecules, including microRNAs. Recent studies have also shown pro-regenerative benefits of EVs derived from induced pluripotent stem (iPS) cells. However, the underlying mechanisms of EV benefits and the role of their transferred regulatory molecules remain incompletely understood. Accordingly, we investigated the effects of human iPS-derived EVs (iPS-EVs) enriched in proangiogenic miR-126 (iPS-miR-126-EVs) on functional properties of human endothelial cells (ECs) in vitro. We also examined the outcomes following EV injection in a murine model of limb ischemia in vivo. EVs were isolated from conditioned media from cultures of unmodified and genetically modified human iPS cells overexpressing miR-126. The iPS-miR-126-EVs were enriched in miR-126 when compared with control iPS-EVs and effectively transferred miR-126 along with other miRNAs to recipient ECs improving their functional properties essential for ischemic tissue repair, including proliferation, metabolic activity, cell survival, migration, and angiogenic potential. Injection of iPS-miR-126-EVs in vivo in a murine model of acute limb ischemia promoted angiogenesis, increased perfusion, and enhanced functional recovery. These observations corresponded with elevated expression of genes for several proangiogenic factors in ischemic tissues following iPS-miR-126-EV transplantation. These results indicate that innate pro-regenerative properties of iPS-EVs may be further enhanced by altering their molecular composition via controlled genetic modifications. Such iPS-EVs overexpressing selected microRNAs, including miR-126, may represent a novel acellular tool for therapy of ischemic tissues in vivo.

Huc-MSC-derived exosomal miR-144 alleviates inflammation in LPS-induced preeclampsia-like pregnant rats via the FosB/Flt-1 pathway

Background

Preeclampsia (PE) is a common and severe hypertensive disorder in pregnancy. Mesenchymal stem cell-derived exosomes (Exos-MSC) have been reported to mitigate the progression of inflammatory diseases. The study aimed to explore the effects of human umbilical cord-derived Exos-MSC (huc-Exos-MSC) on PE-like models.

Methods

Lipopolysaccharide (LPS) was used to construct in vitro and in vivo PE-like models. Exosomes were treated with LPS-induced PE-like cells and rats.

Results

PE-like inflammatory models of pregnant rats and cells were successfully constructed in vivo and in vitro. miR-144 was screened by bioinformatics analysis. Exosomes were successfully extracted. Silencing FosB, overexpressing miR-144 or treating with exosomes extracted from huc-MSC overexpressing miR-144 in (Exos-MSCmiR-144) reversed the LPS-induced decline in HTR-8/SVneo cell viability and migration. In addition, the above groups decreased LPS-induced increases in interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), phosphorylated nuclear factor-kappaB (p-NF-κB)/NF-κB, soluble FMS-like tyrosine kinase 1 (sFlt-1), and Flt-1 levels. Simultaneously, transfection of miR-144 mimics and overexpressing FosB reversed those changes in the miR-144 mimics group. miR-144 might alleviate LPS-induced HTR-8/SVneo cell inflammation by targeting FosB. Injection of Exos-MSCmiR-144 in PE-like pregnant rats reversed LPS-induced increases in FosB expression, systolic and diastolic blood pressure (SBP and DBP), as well as mean arterial pressure (MAP), heart rate, urine albumin/creatine ratio, inflammatory factors, p-NF-κB/NF-κB, and sFlt-1 levels. Furthermore, compared with the model group, the proportion of live births was significantly higher in the model + Exos-MSCmiR-144 group, while the apoptosis rate of fetal rat brain tissue was significantly lower.

Conclusions

We found that huc-Exos-MSC-derived miR-144 alleviated gestational hypertension and inflammation in PE-like pregnant rats by regulating the FosB/Flt-1 pathway. In addition, huc-Exos-MSC-derived miR-144 could partially reverse the LPS-induced adverse pregnancy outcome and brain injury in fetal rats, laying the foundation for developing new treatments for PE.

Influential factors for optimizing and strengthening mesenchymal stem cells and hematopoietic stem cells co-culture

Mesenchymal stem cells (MSCs) and Hematopoietic stem cells (HSCs) are two types of bone marrow stem cells that can proliferate and differentiate into different cell lineages. HSCs interact with MSCs under protective conditions, called niche. Numerous studies have indicated supportive effects of MSCs on HSCs proliferation and differentiation. Furthermore, HSCs have many clinical applications and could treat different hematologic and non-hematologic diseases. For this purpose, there is a need to perform in vitro studies to optimize their expansion. Therefore, various methods including co-culture with MSCs are used to address the limitations of HSCs culture. Some parameters that might be effective for improving the MSC/ HSC co-culture systems. Manipulating culture condition to enhance MSC paracrine activity, scaffolds, hypoxia, culture medium additives, and the use of various MSC sources, have been examined in different studies. In this article, we investigated the potential factors for optimizing HSCs/ MSCs co-culture. It might be helpful to apply a suitable approach for providing high-quality HSCs and improving their therapeutic applications.

Recent advances in mesenchymal stem cell therapy for myocardial infarction

Myocardial infarction refers to the ischemic necrosis of myocardium, characterized by a sharp reduction or interruption of blood flow in the coronary arteries due to the coronary artery occlusion, resulting in severe and prolonged ischemia in the corresponding myocardium and ultimately leading to ischemic necrosis of the myocardium. Given its high risk, it is considered as one of the most serious health threats today. In current clinical practice, multiple approaches have been explored to diminish myocardial oxygen consumption and alleviate symptoms, but notable success remains elusive. Accumulated clinical evidence has showed that the implantation of mesenchymal stem cell for treating myocardial infarction is both effective and safe. Nevertheless, there persists controversy and variability regarding the standardizing MSC transplantation protocols, optimizing dosage, and determining the most effective routes of administration. Addressing these remaining issues will pave the way of integration of MSCs as a feasible mainstream cardiac treatment.

Role of Cisplatin in Inducing Acute Kidney Injury and Pyroptosis in Mice via the Exosome miR-122/ELAVL1 Regulatory Axis

Although cisplatin is an effective chemotherapy drug for the treatment of various cancers, its clinical use is limited due to its side effects, especially nephrotoxicity. Unfortunately, acute kidney injury (AKI) caused by cisplatin remains one of the main challenges in effective cancer treatment. Evidence increasingly suggests that renal inflammation and pyroptotic inflammatory cell death of renal tubular epithelial cells (RTECs) mainly determine the progression and outcome of cisplatin-induced AKI. However, it is not clear how cisplatin regulates the pyroptosis of RTECs cells in AKI. The current study aimed to determine the regulation mechanism of AKI induced by cisplatin. We used cisplatin to induce AKI in vivo. We performed H&E staining of mouse kidney tissue sections and evaluated serological indicators of kidney injury (including blood urea nitrogen (BUN), serum creatinine, and tumor necrosis factor-alpha (TNF-alpha)). We used immunohistochemistry and western blot to detect the important substrate protein gasdermin D (GSDMD) and key target caspase-1 of pyroptosis, respectively. Cisplatin induced mouse AKI and RTECs pyroptosis. HK2 cell-derived exosomes treated with cisplatin influenced pyroptosis of the surrounding HK2 cells. Cisplatin-treated HK2 cells exosome-derived miR-122 regulated pyroptosis in the surrounding cells. Exosome-derived miR-122 affected cisplatin-induced AKI and HK2 cells pyroptosis by regulating the expression of embryonic lethal abnormal vision (ELAVL1). These results suggest that exosome miR-122 inhibited pyroptosis and AKI by targeting ELAVL1 under cisplatin treatment, and this offers a potential target for the treatment of AKI.

Mesenchymal Stem Cell-Derived Exosomal microRNAs in Cardiac Regeneration

Mesenchymal stem cell (MSC)-based therapy is one of the most promising modalities for cardiac repair. Accumulated evidence suggests that the therapeutic value of MSCs is mainly attributable to exosomes. MSC-derived exosomes (MSC-Exos) replicate the beneficial effects of MSCs by regulating various cellular responses and signaling pathways implicated in cardiac regeneration and repair. miRNAs constitute an important fraction of exosome content and are key contributors to the biological function of MSC-Exo. MSC-Exo carrying specific miRNAs provides anti-apoptotic, anti-inflammatory, anti-fibrotic, and angiogenic effects within the infarcted heart. Studying exosomal miRNAs will provide an important insight into the molecular mechanisms of MSC-Exo in cardiac regeneration and repair. This significant information can help optimize cell-free treatment and overcome the challenges associated with MSC-Exo therapeutic application. In this review, we summarize the characteristics and the potential mechanisms of MSC-derived exosomal miRNAs in cardiac repair and regeneration.

Extracellular vesicle-carried GTF2I from mesenchymal stem cells promotes the expression of tumor-suppressive FAT1 and inhibits stemness maintenance in thyroid carcinoma

Through bioinformatics predictions, we identified that GTF2I and FAT1 were downregulated in thyroid carcinoma (TC). Further, Pearson's correlation coefficient revealed a positive correlation between GTF2I expression and FAT1 expression. Therefore, we selected them for this present study, where the effects of bone marrow mesenchymal stem cell-derived EVs (BMSDs-EVs) enriched with GTF2I were evaluated on the epithelial-to-mesenchymal transition (EMT) and stemness maintenance in TC. The under-expression of GTF2I and FAT1 was validated in TC cell lines. Ectopically expressed GTF2I and FAT1 were found to augment malignant phenotypes of TC cells, EMT, and stemness maintenance. Mechanistic studies revealed that GTF2I bound to the promoter region of FAT1 and consequently upregulated its expression. MSC-EVs could shuttle GTF2I into TPC-1 cells, where GTF2I inhibited TC malignant phenotypes, EMT, and stemness maintenance by increasing the expression of FAT1 and facilitating the FAT1-mediated CDK4/FOXM1 downregulation. In vivo experiments confirmed that silencing of GTF2I accelerated tumor growth in nude mice. Taken together, our work suggests that GTF2I transferred by MSC-EVs confer antioncogenic effects through the FAT1/CDK4/FOXM1 axis and may be used as a promising biomarker for TC treatment.

Selective cargo sorting in stem cell-derived small extracellular vesicles: impact on therapeutic efficacy for intervertebral disc degeneration

BACKGROUND

Growing evidence has suggested the role of stem cell-derived small extracellular vesicles (sEVs) in intervertebral disc degeneration (IVDD). The cargo sorting of sEVs, particularly miRNAs, may be influenced when the donor cell is subjected to oxidative stress. Here, we discovered that miRNAs containing specific motifs are selectively sorted into intraluminal vesicles within mesenchymal stem cells (MSCs) in response to oxidative stress.

METHODS

Analysis of miRNA cargoes in sEVs derived from normal MSCs (C-sEVs) or stressed MSCs (T-sEVs) was conducted using miRNA sequencing. Differential expressed miRNAs in sEVs and the identification of motifs were evaluated through bioinformatics analysis. Protein binding was assessed using immunofluorescent staining and immunoprecipitation analysis. Additionally, RNA pull down and RNA immunoprecipitation (RIP) immunoprecipitation were employed to determine the binding between miRNAs and proteins. The effects of C-sEVs and T-sEVs on IVDD were compared by detecting the expression levels of phenotypic genes in vitro or histological evaluation in vivo.

RESULTS

The sorting process of miRNAs is mediated by the nucleocytoplasmic transport of heterogeneous nuclear ribonucleoproteins, which in turn facilitates the phosphorylation of SNAP25 and promotes the transport and secretion of sEVs. Additionally, CHMP1B plays a role in membrane repair and protects against cell ferroptosis upon oxidative stress, concurrently affecting the release of sEVs. Notably, stem cell-derived sEVs associated with ferroptosis impair the therapeutic efficacy for IVDD. However, the application of engineered sEVs containing a specific miRNA inhibitor exhibits the potential to reinstate the therapeutic efficacy for IVDD both in vitro and in vivo.

CONCLUSIONS

Taken together, our findings shed light on the mechanism of miRNAs sorting into sEVs and offer new insights for the optimization of sEV-based treatments during intervertebral disc regeneration. regeneration.

Embryonic stem cell-derived extracellular vesicles rejuvenate senescent cells and antagonize aging in mice

Aging is a degenerative process that leads to tissue dysfunction and death. Embryonic stem cells (ESCs) have great therapeutic potential for age-related diseases due to their capacity for self-renewal and plasticity. However, the use of ESCs in clinical treatment is limited by immune rejection, tumourigenicity and ethical issues. ESC-derived extracellular vesicles (EVs) may provide therapeutic effects that are comparable to those of ESCs while avoiding unwanted effects. Here, we fully evaluate the role of ESC-EVs in rejuvenation in vitro and in vivo. Using RNA sequencing (RNA-Seq) and microRNA sequencing (miRNA-Seq) screening, we found that miR-15b-5p and miR-290a-5p were highly enriched in ESC-EVs, and induced rejuvenation by silencing the Ccn2-mediated AKT/mTOR pathway. These results demonstrate that miR-15b-5p and miR-290a-5p function as potent activators of rejuvenation mediated by ESC-EVs. The rejuvenating effect of ESC-EVs was further investigated in vivo by injection into aged mice. The results showed that ESC-EVs successfully ameliorated the pathological age-related phenotypes and rescued the transcriptome profile of aged mice. Our findings demonstrate that ESC-EVs treatment can rejuvenate senescence both in vitro and in vivo and suggest the therapeutic potential of ESC-EVs as a novel cell-free alternative to ESCs for age-related diseases.

Advances in stem cell therapy for peritoneal fibrosis: from mechanisms to therapeutics

Peritoneal fibrosis (PF) is a pathophysiological condition caused by a variety of pathogenic factors. The most important features of PF are mesothelial-mesenchymal transition and accumulation of activated (myo-)fibroblasts, which hinder effective treatment; thus, it is critical to identify other practical approaches. Recently, stem cell (SC) therapy has been indicated to be a potential strategy for this disease. Increasing evidence suggests that many kinds of SCs alleviate PF mainly by differentiating into mesothelial cells; secreting cytokines and extracellular vesicles; or modulating immune cells, particularly macrophages. However, there are relatively few articles summarizing research in this direction. In this review, we summarize the risk factors for PF and discuss the therapeutic roles of SCs from different sources. In addition, we outline effective approaches and potential mechanisms of SC therapy for PF. We hope that our review of articles in this area will provide further inspiration for research on the use of SCs in PF treatment.

Extracellular vesicles derived from umbilical cord mesenchymal stromal cells show enhanced anti-inflammatory properties via upregulation of miRNAs after pro-inflammatory priming

Autoimmune conditions, such as rheumatoid arthritis, are characterised by a loss of immune tolerance, whereby the immune cells attack self-antigens causing pain and inflammation. These conditions can be brought into remission using pharmaceutical treatments, but often have adverse side effects and some patients do not respond favourably to them. Human umbilical cord mesenchymal stromal cells (UCMSCs) present a promising alternative therapeutic due to their innate anti-inflammatory properties which can be strengthened using pro-inflammatory conditions. Their therapeutic mechanism of action has been attributed to paracrine signalling, by which nanosized acellular particles called 'extracellular vesicles' (EVs) are one of the essential components. Therefore, this research analysed the anti-inflammatory properties of UCMSC-EVs 'primed' with pro-inflammatory cytokines and at baseline with no inflammatory cytokines (control). Both control and primed EVs were co-cultured with un-pooled peripheral blood mononuclear cells (PBMCs; n = 6) from healthy donors. Neither control nor primed EVs exerted a pro-inflammatory effect on PBMCs. Instead, the primed EVs showed the immunosuppressive potential by increasing the expression of the anti-inflammatory protein FoxP3 in PBMCs. This may be attributed to the upregulated miRNAs identified in primed EVs in comparison to control EVs (miR-139-5p, miR-140-5p, miR-214-5p). These findings aid in understanding how UCMSC-EVs mediate immunosuppression and support their potential use in treating autoimmune conditions.

RNAi therapies: Expanding applications for extrahepatic diseases and overcoming delivery challenges

The era of RNA medicine has become a reality with the success of messenger RNA (mRNA) vaccines against COVID-19 and the approval of several RNA interference (RNAi) agents in recent years. Particularly, therapeutics based on RNAi offer the promise of targeting intractable and previously undruggable disease genes. Recent advances have focused in developing delivery systems to enhance the poor cellular uptake and insufficient pharmacokinetic properties of RNAi therapeutics and thereby improve its efficacy and safety. However, such approach has been mainly achieved via lipid nanoparticles (LNPs) or chemical conjugation with N-Acetylgalactosamine (GalNAc), thus current RNAi therapy has been limited to liver diseases, most likely to encounter liver-targeting limitations. Hence, there is a huge unmet medical need for intense evolution of RNAi therapeutics delivery systems to target extrahepatic tissues and ultimately extend their indications for treating various intractable diseases. In this review, challenges of delivering RNAi therapeutics to tumors and major organs are discussed, as well as their transition to clinical trials. This review also highlights innovative and promising preclinical RNAi-based delivery platforms for the treatment of extrahepatic diseases.

Extracellular Vesicle MicroRNAs From Corneal Stromal Stem Cell Enhance Stemness of Limbal Epithelial Stem Cells by Targeting the Notch Pathway

Purpose

The limbal niche supports the self-renewal of limbal epithelial stem cells (LESCs). The corneal stromal stem cell (CSSC) is an important component in the niche that regulates the LESC phenotype. However, the intercellular communication between LESCs and CSSCs has yet to be elucidated.

Methods

A traditional two-dimensional (2D) system, a direct three-dimensional (3D) system, and an indirect 3D coculture system of LESCs and CSSCs were used to elucidate the paracrine pathway effect of CSSCs on LESCs. To reveal the impact of CSSC derived extracellular vesicles (CSSC-EVs) on LESCs, GW4869 and CSSC-EVs were added separately to the LESC culture medium. The outgrowth rate, cell density, differentiation, and stemness maintenance were compared among these methods. The miRNAs in the CSSC-EVs were sequenced, and the targeted Notch pathway was further confirmed by RT‒qPCR and Western blotting.

Results

Compared with 2D culture, both the direct and indirect 3D coculture systems yielded a higher outgrowth rate and expression of stem cell markers of LESCs. The phenotypes of LESCs cultivated using the two coculture approaches were also comparable. Nevertheless, GW4869 inhibited the effect of CSSCs on LESCs, and the addition of CSSC-EVs to the 2D culture system could increase cell density, and the proportion of p63αbright cells, which indicated that CSSC-EVs were crucial in regulating LESCs. Furthermore, the EV-AlixKD with reduced miRNA partly lost its regulating function. The abundant miRNAs in CSSC-EVs, such as hsa-miR-663b, hsa-miR-16-5p, and hsa-miR-1290, target the Notch pathway. The LESCs transfected with miR-663b had higher p63 expression via downregulating of the Notch pathway.

Conclusions

CSSC-EV played an important role in promoting LESC proliferation and stemness maintenance by targeting Notch signaling via miRNAs, which will increase our understanding of the limbal niche and provide a potential new approach for LESC culture and the treatment of corneal epithelial disorders.

Extracellular Vesicles Derived from Mesenchymal Stem Cells as Cell-Free Therapy for Intrauterine Adhesion

Intrauterine adhesion (IUA) can occur after trauma to the basal layer of the endometrium, contributing to severe complications in females, such as infertility and amenorrhea. To date, the proposed therapeutic strategies are targeted to relieve IUA, such as hysteroscopic adhesiolysis, Foley catheter balloon, and hyaluronic acid injection have been applied in the clinic. However, these approaches showed limited effects in alleviating endometrial fibrosis and thin endometrium. Mesenchymal stem cells (MSCs) can offer the potential for endometrium regeneration owing to reduce inflammation and release growth factors. On this basis, MSCs have been proposed as promising methods to treat intrauterine adhesion. However, due to the drawbacks of cell therapy, the possible therapeutic use of extracellular vesicles released by stem cells is raising increasing interest. The paracrine effect, mediated by MSCs derived extracellular vehicles (MSC-EVs), has recently been suggested as a mechanism for their therapeutic properties. Here, we summarizes the main pathological mechanisms involved in intrauterine adhesion, the biogenesis and characteristics of extracellular vesicles, explaining how these vesicles could provide new opportunities for MSCs.