Human umbilical cord mesenchymal stem cell-derived exosomes promote neurological function recovery in rat after traumatic brain injury by inhibiting the activation of microglia and astrocyte

UCMSCs-derived exosomal SLIT2 alleviates ischemic stroke through the β-catenin/TCF4/USP20 signaling pathway

BACKGROUND

Ischemic stroke (IS) is a disease that causes necrosis of brain tissues by inadequate blood supply to the brain. Umbilical cord mesenchymal stem cells (UCMSCs)-derived exosomes (UCMSCs-Exo) have been reported to alleviate IS, and slit guidance ligand 2 (SLIT2) could promote neurological repair after IS. The aim of this research was to explore the potential mechanism of UCMSCs-derived exosomal SLIT2 on IS progression.

METHODS

The middle cerebral artery occlusion (MCAO) rat and oxygen glucose deprivation/reperfusion (OGD/R)-induced cellular models were established, and then treated with UCMSCs-Exo. Cell viability and apoptosis were explored by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. The expressions of ubiquitin specific peptidase 20 (USP20) and related apoptotic proteins were determined using Western blot. Immunofluorescence and immunohistochemistry were performed to evaluate the effect of SLIT2 on β-catenin nuclear translocation. The association between transcription factor 4 (TCF4) and USP20 promoter was investigated by chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assys.

RESULTS

In the OGD/R-induced cell model, UCMSCs-derived exosomal SLIT2 increased cell viability, decreased apoptosis and promoted β-catenin nuclear translocation. Besides, β-catenin agonist (SKL2001) facilitated USP20 transcription by promoting TCF4 binding to USP20 promoter. Finally, TCF4 upregulated USP20 and inhibited OGD/R-induced cell damage. In the MCAO rat model, UCMSCs-derived exosomal SLIT2 mitigated IS by promoting β-catenin nuclear translocation, which activated the TCF4/USP20 pathway to inhibit apoptosis.

CONCLUSION

UCMSCs-derived exosomal SLIT2 activated TCF4 by promoting β-catenin nuclear translocation, which transcriptionally upregulated USP20 expression, thereby attenuating OGD/R-induced neuroncell damage and ultimately leading to inhibition of IS progression.

Effect of administration routes on the efficacy of human umbilical cord mesenchymal stem cells in type 2 diabetic rats

Background

Human umbilical cord mesenchymal stem cells (UCMSCs) are being investigated in various clinical trials for different conditions, including type 2 diabetes mellitus (T2DM). However, there is limited research on the optimal injection routes for UCMSCs in T2DM, particularly intravenous injection.

Objective

The objective of this study aims to investigate the efficacy of four different administration routes of UCMSCs in treating T2DM rats, including pancreas injection (DP), tail vein injection (DT), intraperitoneal injection (DI), and dorsal pancreatic artery injection (DPA).

Results

After two weeks of UCMSCs treatment, the fasting blood glucose levels in the DT group decreased significantly. The oral glucose tolerance test (OGTT) levels and the islet structure in the DT group almost recovered to normal. The contents of C-P and GLP-1 in serum increased significantly in all treatment groups, while the levels of INS, TNF-α, IL-6, IL-1β, IAA, and GSP decreased significantly. These improvements were further observed after four weeks of UCMSCs treatment. Histological analysis confirmed the progression of pancreatic recovery in all treatment groups, with the DT group showing the most significant improvement, correlating with the observed efficacy. Immunohistochemistry results further demonstrated increased insulin and PDX-1 expression, along with reduced glucagon levels in UCMSCs-treated rats. Additionally, liver and kidney function significantly improved across all treatment groups, with the DT group showing the best outcomes.

Conclusion

Overall, these findings suggest that the administration route significantly affected the efficacy of UCMSCs in treating T2DM, with tail vein injection showing the most effective results.

Suppression of TP Rat Pancreatic Acinar Cell Apoptosis by hucMSC-Ex Carrying hsa-miR-21-5p via PTEN/PI3K Regulation

Objective: The traumatic pancreatitis (TP) has an alarmingly high mortality rate. Our previous research has demonstrated that human umbilical cord mesenchymal stem cells-derived exosomes (hucMSC-Exs) could treat TP by inhibiting acinar cell apoptosis. Accordingly, the objective of this study is to unravel the intricate mechanism behind the repair of pancreatic injury in TP rats. Methods: A gene interaction network of miRNA was constructed based on the Gene Expression Omnibus (GEO) database (GSE 159814). Our investigation was divided into two groups, and appropriate controls were implemented for each group. The expression levels of inflammatory factors in each group were detected, along with the pathological damage of pancreatic tissue, the percentage of apoptotic cells, and key mRNA and protein expression levels. Results: The miRNA-mRNA gene interaction network suggests that hsa-miR-21-5p/phosphatase and tensin homolog (PTEN) are positioned at the core of this interaction network. Enzyme-linked immunosorbent assay (ELISA) and histological examination (HE) results suggest that pancreatic damage increased in the miR-21 inhibitor and EXW groups, whereas it decreased in the miR-21 activator and EXC groups compared to the EX group. PCR, western blot (WB), and TdT-mediated dUTP Nick-End Labeling (TUNEL) results indicate that hucMSC-Ex carrying hsa-miR-21-5p suppresses excessive activation of PTEN by phosphoinositide 3-kinase (PI3K), exerting therapeutic effects. Conclusion: This study has discovered that hucMSC-Ex effectively inhibits the translation of PTEN via the transported hsa-miR-21-5p, consequently affecting the PI3K/serine-threonine kinase (AKT) signaling pathway. This results in reduced inflammation and inhibition of acinar cell apoptosis by regulating pancreatic enzyme leakage, thereby providing a therapeutic effect on TP.

Human Umbilical Cord Mesenchymal Stem Cell-derived Exosome Regulates Intestinal Type 2 Immunity

AIMS

The aim of this study was to investigate the role of human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-Exo) in regulating the intestinal type 2 immune response for either protection or therapy.

BACKGROUND

hUCMSC-Exo was considered a novel cell-free therapeutic product that shows promise in the treatment of various diseases. Type 2 immunity is a protective immune response classified as T-helper type 2 (Th2) cells and is associated with helminthic infections and allergic diseases. The effect of hUCMSC-Exo on intestinal type 2 immune response is not clear.

METHOD

C57BL/6 mice were used to establish intestinal type 2 immune response by administering of H. poly and treated with hUCMSC-Exo before or after H. poly infection. Intestinal organoids were isolated and co-cultured with IL-4 and hUCMSC-Exo. Then, we monitored the influence of hUCMSC-Exo on type 2 immune response by checking adult worms, the hyperplasia of tuft and goblet cells Result: hUCMSC-Exo significantly delays the colonization of H. poly in subserosal layer of duodenum on day 7 post-infection and promotes the hyperplasia of tuft cells and goblet cells on day 14 post-infection. HUCMSC-Exo enhances the expansion of tuft cells in IL-4 treated intestinal organoids, and promotes lytic cell death.

CONCLUSION

Our study demonstrates hUCMSC-Exo may benefit the host by increasing the tolerance at an early infection stage and then enhancing the intestinal type 2 immune response to impede the helminth during Th2 priming. Our results show hUCMSC-Exo may be a positive regulator of type 2 immune response, suggesting hUCMSC-Exo has a potential therapeutic effect on allergic diseases.

Therapeutic Efficacy and Promise of Human Umbilical Cord Mesenchymal Stem Cell-Derived Extracellular Vesicles in Aging and Age-Related Disorders

The global issue of aging populations has become increasingly prominent, thus the research and development for anti-aging therapies to assure longevity as well as to ameliorate age-related complications is put high on the agenda. The young humoral milieu has been substantiated to impart youthful characteristics to aged cells or organs. Extracellular vesicles (EVs) are a heterogeneous group of cell-derived membrane-limited structures that serve as couriers of proteins and genetic material to regulate intercellular communication. Of note, EVs appeared to be an indispensable component of young blood in prolonging lifespans, and circulating EVs have been indicated to mediate the beneficial effect of a young milieu on aging. Human umbilical cord mesenchymal stem cell-derived EVs (HUCMSC-EVs), isolated from the youngest adult stem cell source, are speculated to reproduce the function of circulating EVs in young blood and partially revitalize numerous organs in old animals. Robust evidence has suggested HUCMSC-EVs as muti-target therapeutic agents in combating aging and alleviating age-related degenerative disorders. Here, we provide a comprehensive overview of the anti-aging effects of HUCMSC-EVs in brain, heart, vasculature, kidney, muscle, bone, and other organs. Furthermore, we critically discuss the current investigation on engineering strategies of HUCMSC-EVs, intending to unveil their full potential in the field of anti-aging research.

Therapeutic potential of EVs loaded with CB2 receptor agonist in spinal cord injury via the Nrf2/HO-1 pathway

BACKGROUND

Spinal cord injury (SCI) poses a challenge due to limited treatment options. Recently, the effect and mechanism of Exo-loaded cannabinoid receptor type 2 (CB2) agonist AM1241(Exo + AM1241) have been applied in other inflammatory diseases but not in SCI.

METHODS

The SCI model was set up using C57BL/6 mice, followed by the treatment of Exo, AM1241, and Exo + AM1241. We assessed the effects of the following treatments on motor function recovery using BMS, and evaluated histological changes, apoptosis activity, inflammation, and oxidative stress in the SCI mice model. Additionally, the effect of following treatments on spinal cord neural stem cells (NSCs) was evaluated under lipopolysaccharides (LPS) induced inflammatory and oxidative models and, glutamate (Gluts) induced cell apoptosis models.

RESULT

Our results demonstrated that Exo + AM1241 treatment significantly improved motor function recovery, after SCI by decreasing proinflammatory cytokines, and suppressing astrocyte/microglia (GFAP/Iba1) activation in the injury zone. Additionally, this treatment reduces pro-apoptotic proteins (Bax and caspase 3), increases the levels of the anti-apoptotic protein Bcl-2, enhances antioxidant defenses by boosting SOD and GSH, and lowers oxidative stress markers such as MDA. It also activates the Nuclear factor erythroid-2 (Nrf2) related factor 2 signaling pathway, thereby enhancing tissue protection against damage and cell death.

The role of microglia in neurological diseases with involvement of extracellular vesicles

As a subset of mononuclear phagocytes in the central nervous system, microglia play a crucial role in immune defense and homeostasis maintenance. Microglia can regulate their states in response to specific signals of health and pathology. Microglia-mediated neuroinflammation is a pathological hallmark of neurodegenerative diseases, neurological damage and neurological tumors, underscoring its key immunoregulatory role in these conditions. Intriguingly, a substantial body of research has indicated that extracellular vesicles can mediate intercellular communication by transporting cargoes from parental cells, a property that is also reflected in microenvironmental signaling networks involving microglia. Based on the microglial characteristics, we briefly outline the biological features of extracellular vesicles and focus on summarizing the integrative role played by microglia in the maintenance of nervous system homeostasis and progression of different neurological diseases. Extracellular vesicles may engage in the homeostasis maintenance and pathological process as a medium of intercellular communication. Here, we aim to provide new insights for further exploration of neurological disease pathogenesis, which may provide theoretical foundations for cell-free therapies.

The functions of exosomes targeting astrocytes and astrocyte-derived exosomes targeting other cell types

Astrocytes are the most abundant glial cells in the central nervous system; they participate in crucial biological processes, maintain brain structure, and regulate nervous system function. Exosomes are cell-derived extracellular vesicles containing various bioactive molecules including proteins, peptides, nucleotides, and lipids secreted from their cellular sources. Increasing evidence shows that exosomes participate in a communication network in the nervous system, in which astrocyte-derived exosomes play important roles. In this review, we have summarized the effects of exosomes targeting astrocytes and the astrocyte-derived exosomes targeting other cell types in the central nervous system. We also discuss the potential research directions of the exosome-based communication network in the nervous system. The exosome-based intercellular communication focused on astrocytes is of great significance to the biological and/or pathological processes in different conditions in the brain. New strategies may be developed for the diagnosis and treatment of neurological disorders by focusing on astrocytes as the central cells and utilizing exosomes as communication mediators.

Exosomal miRNA-21 derived from umbilical cord mesenchymal stem cells inhibits microglial overactivation to counteract nerve damage

BACKGROUND

Traumatic brain injury (TBI) is a major cause of neurological disability, and current treatments have limited effectiveness. Recent studies have emphasized the potential of exosomes derived from umbilical cord mesenchymal stem cells (UC-MSCs-Exo) in TBI treatment, but the molecular mechanisms underlying their therapeutic effects are not fully understood.

METHODS AND RESULTS

In this study, UC-MSCs-Exo was isolated using ultracentrifugation and intraventricularly injected to TBI rat model. The neurofunctional motor function of the rats was evaluated using the modified neurological severity score (mNSS), and the activation of microglia was assessed through immunofluorescence detection of IBA1 expression levels. Additionally, we established an in vitro neuroinflammatory model using BV2 microglia to investigate the effects of UC-MSCs-Exo and miRNA-21. Our findings indicate that UC-MSCs-Exo promote neurological recovery in TBI rats and inhibit excessive microglia activation. Furthermore, UC-MSCs-Exo highly expresses miRNA-21 and inhibited the proliferation, migration, and release of inflammatory mediators of BV2 microglia by transporting miRNA-21.

CONCLUSIONS

The present study suggests that the promotion of neurological recovery in TBI rats by UC-MSCs-Exo may be attributed to the inhibition of excessive microglia activation through miRNA-21.

Effects of spinal cord injury associated exosomes delivered tRF-41 on the progression of spinal cord injury progression

BACKGROUND

Spinal cord injury (SCI) is a devastating neurological and pathological condition. Exosomal tsRNAs have reported to be promising biomarkers for cancer diagnosis and therapy. This study aimed to investigate the roles of SCI-associated exosomes, and related tsRNA mechanisms in SCI.

METHODS

The serum of healthy controls and SCI patients at the acute stage were collected for exosomes isolation, and the two different exosomes were used to treat human astrocytes (HA). The cell viability, apoptosis, and cycle were determined, and the expression of the related proteins were detected by western blot. Then, the two different exosomes were sent for tsRNA sequencing, and four significant known differentially expressed tsRNAs (DE-tsRNAs) were selected for RT-qPCR validation. Finally, tRT-41 was chosen to further explore its roles and related mechanisms in SCI.

RESULTS

After sequencing, 21 DE-tsRNAs were identified, which were significantly enriched in pathways of Apelin, AMPK, Hippo, MAPK, Ras, calcium, PI3K-Akt, and Rap1. RT-qPCR showed that tRF-41 had higher levels in the SCI-associated exosomes. Compared with the control HA, healthy exosomes did not significantly affect the growth of HA cells, but SCI-associated exosomes inhibited viability of HA cells, while promoted their apoptosis and increased the HA cells in G2/M phase; but tRF-41 inhibitor reversed the actions of SCI-associated exosomes. Additionally, SCI-associated exosomes, similar with tRF-41 mimics, down-regulated IGF-1, NGF, Wnt3a, and β-catenin, while up-regulated IL-1β and IL-6; but tRF-41 inhibitor had the opposite actions, and reversed the effects induced by SCI-associated exosomes.

CONCLUSIONS

SCI-associated exosomes delivered tRF-41 may inhibit the growth of HA through regulating Wnt/ β-catenin pathway and inflammation response, thereby facilitating the progression of SCI.

Mesenchymal stem cell‐derived extracellular vesicles: Recent therapeutics and targeted drug delivery advances

The targeted drug delivery field is rapidly advancing, focusing on developing biocompatible nanoparticles that meet rigorous criteria of non‐toxicity, biocompatibility, and efficient release of encapsulated molecules. Conventional synthetic nanoparticles (SNPs) face complications such as elevated immune responses, complex synthesis methods, and toxicity, which restrict their utility in therapeutics and drug delivery. Extracellular vesicles (EVs) have emerged as promising substitutes for SNPs, leveraging their ability to cross biological barriers, biocompatibility, reduced toxicity, and natural origin. Notably, mesenchymal stem cell‐derived EVs (MSC‐EVs) have garnered much curiosity due to their potential in therapeutics and drug delivery. Studies suggest that MSC‐EVs, the central paracrine contributors of MSCs, replicate the therapeutic effects of MSCs. This review explores the characteristics of MSC‐EVs, emphasizing their potential in therapeutics and drug delivery for various diseases, including CRISPR/Cas9 delivery for gene editing. It also delves into the obstacles and challenges of MSC‐EVs in clinical applications and provides insights into strategies to overcome the limitations of biodistribution and target delivery.

Extracellular vesicles as carriers for noncoding RNA-based regulation of macrophage/microglia polarization: an emerging candidate regulator for lung and traumatic brain injuries

Macrophage/microglia function as immune defense and homeostatic cells that originate from bone marrow progenitor cells. Macrophage/microglia activation is historically divided into proinflammatory M1 or anti-inflammatory M2 states based on intracellular dynamics and protein production. The polarization of macrophages/microglia involves a pivotal impact in modulating the development of inflammatory disorders, namely lung and traumatic brain injuries. Recent evidence indicates shared signaling pathways in lung and traumatic brain injuries, regulated through non-coding RNAs (ncRNAs) loaded into extracellular vesicles (EVs). This packaging protects ncRNAs from degradation. These vesicles are subcellular components released through a paracellular mechanism, constituting a group of nanoparticles that involve exosomes, microvesicles, and apoptotic bodies. EVs are characterized by a double-layered membrane and are abound with proteins, nucleic acids, and other bioactive compounds. ncRNAs are RNA molecules with functional roles, despite their absence of coding capacity. They actively participate in the regulation of mRNA expression and function through various mechanisms. Recent studies pointed out that selective packaging of ncRNAs into EVs plays a role in modulating distinct facets of macrophage/microglia polarization, under conditions of lung and traumatic brain injuries. This study will explore the latest findings regarding the role of EVs in the progression of lung and traumatic brain injuries, with a specific focus on the involvement of ncRNAs within these vesicles. The conclusion of this review will emphasize the clinical opportunities presented by EV-ncRNAs, underscoring their potential functions as both biomarkers and targets for therapeutic interventions.

A New Strategy for the Regulation of Neuroinflammation: Exosomes Derived from Mesenchymal Stem Cells

Neuroinflammation is an important pathogenesis of neurological diseases and causes a series of physiopathological changes, such as abnormal activation of glial cells, neuronal degeneration and death, and disruption of the blood‒brain barrier. Therefore, modulating inflammation may be an important therapeutic tool for treating neurological diseases. Mesenchymal stem cells (MSCs), as pluripotent stem cells, have great therapeutic potential for neurological diseases due to their regenerative ability, immunity, and ability to regulate inflammation. However, recent studies have shown that MSC-derived exosomes (MSC-Exos) play a major role in this process and play a key role in neuroprotection by regulating neuroglia. This review summarizes the recent progress made in regulating neuroinflammation by focusing on the mechanisms by which MSC-Exos are involved in the regulation of glial cells through signaling pathways such as the TLR, NF-κB, MAPK, STAT, and NLRP3 pathways to provide some references for subsequent research and therapy.

Mesenchymal stem cell-derived extracellular vesicles for human diseases

Stem cell therapy is a novel approach for treating various severe and intractable diseases, including autoimmune disorders, organ transplants, tumors, and neurodegenerative diseases. Nevertheless, the extensive utilization of stem cells is constrained by potential tumorigenicity, challenges in precise differentiation, rejection concerns, and ethical considerations. Extracellular vesicles possess the ability to carry diverse bioactive factors from stem cells and deliver them to specific target cells or tissues. Moreover, they offer the advantage of low immunogenicity. Consequently, they have the potential to facilitate the therapeutic potential of stem cells, mitigating the risks associated with direct stem cell application. Therefore, the use of stem cell extracellular vesicles in clinical diseases has received increasing attention. This review summarizes advances in the use of extracellular vesicles from mesenchymal stem cells (MSC). MSC extracellular vesicles are used in the treatment of inflammatory diseases such as rheumatoid arthritis, liver injury, COVID-19, and allergies; in the repair of tissue damage in heart disease, kidney injury, and osteoarthritic diseases; as a carrier in the treatment of tumors; and as a regenerative agent in neurodegenerative disorders such as Alzheimer's and Parkinson's.

Exosomes in neuron-glia communication: A review on neurodegeneration

Introduction

Exosomes, a subset of extracellular vesicles (EVs), are crucial for intercellular communication in various contexts. Despite their small size, they carry diverse cargo, including RNA, proteins, and lipids. Internalization by recipient cells raises concerns about potential disruptions to cellular functions. Notably, the ability of exosomes to traverse the blood-brain barrier (BBB) has significant implications.

Methods

To conduct a thorough investigation into the existing academic literature on exosomes within the framework of neuron-glia communication, a comprehensive search strategy was implemented across the PubMed, Google Scholar, and Science Direct databases. Multiple iterations of the keywords "exosome," "neuron-glia communication," and "neurological disorders" were employed to systematically identify relevant publications. Furthermore, an exploration of the Clinicaltrials.gov database was undertaken to identify clinical trials related to cellular signaling, utilizing analogous terminology.

Results

Although the immediate practical applications of exosomes are somewhat limited, their potential as carriers of pathogenic attributes offers promising opportunities for the development of precisely targeted therapeutic strategies for neurological disorders. This review presents a comprehensive overview of contemporary insights into the pivotal roles played by exosomes as agents mediating communication between neurons and glial cells within the central nervous system (CNS).

Conclusion

By delving into the intricate dynamics of exosomal communication in the CNS, this review contributes to a deeper understanding of the roles of exosomes in both physiological and pathological processes, thereby paving the way for potential therapeutic advancements in the field of neurological disorders.

Differentiation of Neurons, Astrocytes, Oligodendrocytes and Microglia From Human Induced Pluripotent Stem Cells to Form Neural Tissue-On-Chip: A Neuroinflammation Model to Evaluate the Therapeutic Potential of Extracellular Vesicles Derived from Mesenchymal Stem Cells

Advances in stem cell (SC) technology allow the generation of cellular models that recapitulate the histological, molecular and physiological properties of humanized in vitro three dimensional (3D) models, as well as production of cell-derived therapeutics such as extracellular vesicles (EVs). Improvements in organ-on-chip platforms and human induced pluripotent stem cells (hiPSCs) derived neural/glial cells provide unprecedented systems for studying 3D personalized neural tissue modeling with easy setup and fast output. Here, we highlight the key points in differentiation procedures for neurons, astrocytes, oligodendrocytes and microglia from single origin hiPSCs. Additionally, we present a well-defined humanized neural tissue-on-chip model composed of differentiated cells with the same genetic backgrounds, as well as the therapeutic potential of bone marrow mesenchymal stem cells (BMSCs)-derived extracellular vesicles to propose a novel treatment for neuroinflammation derived diseases. Around 100 nm CD9 + EVs promote a more anti-inflammatory and pro-remodeling of cell-cell interaction cytokine responses on tumor necrosis factor-α (TNF-α) induced neuroinflammation in neural tissue-on-chip model which is ideal for modeling authentic neural-glial patho-physiology.

The emerging role of exosomes in communication between the periphery and the central nervous system

Exosomes, membrane-enclosed vesicles, are secreted by all types of cells. Exosomes can transport various molecules, including proteins, lipids, functional mRNAs, and microRNAs, and can be circulated to various recipient cells, leading to the production of local paracrine or distal systemic effects. Numerous studies have proved that exosomes can pass through the blood-brain barrier, thus, enabling the transfer of peripheral substances into the central nervous system (CNS). Consequently, exosomes may be a vital factor in the exchange of information between the periphery and CNS. This review will discuss the structure, biogenesis, and functional characterization of exosomes and summarize the role of peripheral exosomes deriving from tissues like the lung, gut, skeletal muscle, and various stem cell types in communicating with the CNS and influencing the brain's function. Then, we further discuss the potential therapeutic effects of exosomes in brain diseases and the clinical opportunities and challenges. Gaining a clearer insight into the communication between the CNS and the external areas of the body will help us to ascertain the role of the peripheral elements in the maintenance of brain health and illness and will facilitate the design of minimally invasive techniques for diagnosing and treating brain diseases.

Secretome as a Tool to Treat Neurological Conditions: Are We Ready?

Due to their characteristics, mesenchymal stem cells (MSCs) are considered a potential therapy for brain tissue injury or degeneration. Nevertheless, despite the promising results observed, there has been a growing interest in the use of cell-free therapies in regenerative medicine, such as the use of stem cell secretome. This review provides an in-depth compilation of data regarding the secretome composition, protocols used for its preparation, as well as existing information on the impact of secretome administration on various brain conditions, pointing out gaps and highlighting relevant findings. Moreover, due to the ability of MSCs to respond differently depending on their microenvironment, preconditioning of MSCs has been used to modulate their composition and, consequently, their therapeutic potential. The different strategies used to modulate the MSC secretome were also reviewed. Although secretome administration was effective in improving functional impairments, regeneration, neuroprotection, and reducing inflammation in brain tissue, a high variability in secretome preparation and administration was identified, compromising the transposition of preclinical data to clinical studies. Indeed, there are no reports of the use of secretome in clinical trials. Despite the existing limitations and lack of clinical data, secretome administration is a potential tool for the treatment of various diseases that impact the CNS.

Stem Cell Therapy in Children with Traumatic Brain Injury

Pediatric traumatic brain injury is a cause of major mortality, and resultant neurological sequelae areassociated with long-term morbidity. Increasing studies have revealed stem cell therapy to be a potential new treatment. However, much work is still required to clarify the mechanism of action of effective stem cell therapy, type of stem cell therapy, optimal timing of therapy initiation, combination of cocurrent medical treatment and patient selection criteria. This paper will focus on stem cell therapy in children with traumatic brain injury.

The Role of Microglial Exosomes and miR-124-3p in Neuroinflammation and Neuronal Repair after Traumatic Brain Injury

(1) Background: In this study, we aimed to explore the regulatory mechanism of miR-124-3p microglial exosomes, as they were previously reported to modulate neuroinflammation and promote neuronal repair following traumatic brain injury (TBI). (2) Methods: Studies investigating the impact of microglial exosomal miRNAs, specifically miR-124-3p, on injured neurons and brain microvascular endothelial cells (BMVECs) in the context of TBI were reviewed. (3) Results: Animal models of TBI, in vitro cell culture experiments, RNA sequencing analysis, and functional assays were employed to elucidate the mechanisms underlying the effects of miR-124-3p-loaded exosomes on neuroinflammation and neuronal repair. Anti-inflammatory M2 polarization of microglia, mTOR signaling suppression, and BMVECs-mediated autophagy were reported as the main processes contributing to neuroprotection, reduced blood-brain barrier leakage, and improved neurologic outcomes in animal models of TBI. (4) Conclusions: Microglial exosomes, particularly those carrying miR-124-3p, have emerged as promising candidates for therapeutic interventions in TBI. These exosomes exhibit neuroprotective effects, attenuate neuroinflammation, and promote neuronal repair and plasticity. However, further research is required to fully elucidate the underlying mechanisms and optimize their delivery strategies for effective treatment in human TBI cases.

Mesenchymal Stem Cells in Soft Tissue Regenerative Medicine: A Comprehensive Review

Soft tissue regeneration holds significant promise for addressing various clinical challenges, ranging from craniofacial and oral tissue defects to blood vessels, muscle, and fibrous tissue regeneration. Mesenchymal stem cells (MSCs) have emerged as a promising tool in regenerative medicine due to their unique characteristics and potential to differentiate into multiple cell lineages. This comprehensive review explores the role of MSCs in different aspects of soft tissue regeneration, including their application in craniofacial and oral soft tissue regeneration, nerve regeneration, blood vessel regeneration, muscle regeneration, and fibrous tissue regeneration. By examining the latest research findings and clinical advancements, this article aims to provide insights into the current state of MSC-based therapies in soft tissue regenerative medicine.

Biogenesis, Composition and Potential Therapeutic Applications of Mesenchymal Stem Cells Derived Exosomes in Various Diseases

Exosomes are nanovesicles with a wide range of chemical compositions used in many different applications. Mesenchymal stem cell-derived exosomes (MSCs-EXOs) are spherical vesicles that have been shown to mediate tissue regeneration in a variety of diseases, including neurological, autoimmune and inflammatory, cancer, ischemic heart disease, lung injury, and liver fibrosis. They can modulate the immune response by interacting with immune effector cells due to the presence of anti-inflammatory compounds and are involved in intercellular communication through various types of cargo. MSCs-EXOs exhibit cytokine storm-mitigating properties in response to COVID-19. This review discussed the potential function of MSCs-EXOs in a variety of diseases including neurological, notably epileptic encephalopathy and Parkinson's disease, cancer, angiogenesis, autoimmune and inflammatory diseases. We provided an overview of exosome biogenesis and factors that regulate exosome biogenesis. Additionally, we highlight the functions and potential use of MSCs-EXOs in the treatment of the inflammatory disease COVID-19. Finally, we covered a strategies and challenges of MSCs-EXOs. Finally, we discuss conclusion and future perspectives of MSCs-EXOs.

Efficacy of extracellular vesicles of different cell origins in traumatic brain injury: A systematic review and network meta-analysis

Background

There was still no effective treatment for traumatic brain injury (TBI). Recently, many preclinical studies had shown promising efficacy of extracellular vesicles (EVs) from various cell sources. Our aim was to compare which cell-derived EVs were most effective in treating TBI through a network meta-analysis.

Methods

We searched four databases and screened various cell-derived EVs for use in preclinical studies of TBI treatment. A systematic review and network meta-analysis were conducted for two outcome indicators, modified Neurological Severity Score (mNSS) and Morris Water Maze (MWM), and they were ranked by the surface under the cumulative ranking curves (SUCRA). Bias risk assessment was performed with SYRCLE. R software (version 4.1.3, Boston, MA, USA) was used for data analysis.

Results

A total of 20 studies were included in this study, involving 383 animals. Astrocyte-derived extracellular vesicles (AEVs) ranked first in response to mNSS at day 1 (SUCRA: 0.26%), day 3 (SUCRA: 16.32%), and day 7 (SUCRA: 9.64%) post-TBI. Extracellular vesicles derived from mesenchymal stem cells (MSCEVs) were most effective in mNSS assessment on day 14 (SUCRA: 21.94%) and day 28 (SUCRA: 6.26%), as well as MWM’s escape latency (SUCRA: 6.16%) and time spent in the target quadrant (SUCRA: 86.52%). The result of mNSS analysis on day 21 showed that neural stem cell-derived extracellular vesicles (NSCEVs) had the best curative effect (SUCRA: 6.76%).

Conclusion

AEVs may be the best choice to improve early mNSS recovery after TBI. The efficacy of MSCEVs may be the best in the late mNSS and MWM after TBI.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023377350.