New roles of tumor-derived exosomes in tumor microenvironment

Throughout tumorigenesis, the co-evolution of tumor cells and their surrounding microenvironment leads to the development of malignant phenotypes. Cellular communication within the tumor microenvironment(TME) plays a critical role in influencing various aspects of tumor progression, including invasion and metastasis. The release of exosomes, a type of extracellular vesicle, by most cell types in the body, is an essential mediator of intercellular communication. A growing body of research indicates that tumor-derived exosomes(TDEs) significantly expedite tumor progression through multiple mechanisms, inducing epithelial-mesenchymal transition and macrophage polarization, enhancing angiogenesis, and aiding in the immune evasion of tumor cells. Herein, we describe the formation and characteristics of the TME, and summarize the contents of TDEs and their diverse functions in modulating tumor development. Furthermore, we explore potential applications of TDEs in tumor diagnosis and treatment.

Proteomics-based identification of proteins in tumor-derived exosomes as candidate biomarkers for colorectal cancer

BACKGROUND Colorectal cancer(CRC)is the second leading cause of cancer-related death,with high morbidity worldwide.There is an urgent need to find reliable diagnostic biomarkers of CRC and explore the underlying molecular mechanisms.Exosomes are involved in intercellular communication and participate in multiple pathological processes,serving as an important part of the tumor microenvironment.AIM To investigate the proteomic characteristics of CRC tumor-derived exosomes and to identify candidate exosomal protein markers for CRC.METHODS In this study,10 patients over 50 years old who were diagnosed with moderately differentiated adenocarcinoma were recruited.We paired CRC tissues and adjacent normal intestinal tissues(>5 cm)to form the experimental and control groups.Purified exosomes were extracted separately from each tissue sample.Data-independent acquisition mass spectrometry was implemented in 8 matched samples of exosomes to explore the proteomic expression profiles,and differentially expressed proteins(DEPs)were screened by bioinformatics analysis.Promising exosomal proteins were verified using parallel reaction monitoring(PRM)analysis in 10 matched exosome samples.RESULTS A total of 1393 proteins were identified in the CRC tissue group,1304 proteins were identified in the adjacent tissue group,and 283 proteins were significantly differentially expressed between them.Enrichment analysis revealed that DEPs were involved in multiple biological processes related to cytoskeleton construction,cell movement and migration,immune response,tumor growth and telomere metabolism,as well as ECM-receptor interaction,focal adhesion and mTOR signaling pathways.Six differentially expressed exosomal proteins(NHP2,OLFM4,TOP1,SAMP,TAGL and TRIM28)were validated by PRM analysis and evaluated by receiver operating characteristic curve(ROC)analysis.The area under the ROC curve was 0.93,0.96,0.97,0.78,0.75,and 0.88(P<0.05)for NHP2,OLFM4,TOP1,SAMP,TAGL,and TRIM28,respectively,indicating their good ability to distinguish CRC tissues from adjacent intestinal tissues.CONCLUSION In our study,comprehensive proteomic profiles were obtained for CRC tissue exosomes.Six exosomal proteins,NHP2,OLFM4,TOP1,SAMP,TAGL and TRIM28,may be promising diagnostic markers and effective therapeutic targets for CRC,but further experimental investigation is needed.

Jiedu recipe,a compound Chinese herbal medicine,suppresses hepatocellular carcinoma metastasis by inhibiting the release of tumor-derived exosomes in a hypoxic microenvironment

Objective:Tumor-derived exosomes(TDEs)play crucial roles in intercellular communication.Hypoxia in the tumor microenvironment enhances secretion of TDEs and accelerates tumor metastasis.Jiedu recipe(JR),a traditional Chinese medicinal formula,has demonstrated efficacy in preventing the metastasis of hepatocellular carcinoma(HCC).However,the underlying mechanism remains largely unknown.Methods:Animal experiments were performed to investigate the metastasis-preventing effects of JR.Bioinformatics analysis and in vitro assays were conducted to explore the potential targets and active components of JR.TDEs were assessed using nanoparticle tracking analysis(NTA)and Western blotting(WB).Exosomes derived from normoxic or hypoxic HCC cells(H-TDEs)were collected to establish premetastatic mouse models.JR was intragastrically administered to evaluate its metastasis-preventive effects.WB and lysosomal staining were performed to investigate the effects of JR on lysosomal function and autophagy.Bioinformatics analysis,WB,NTA,and immunofluorescence staining were used to identify the active components and potential targets of JR.Results:JR effectively inhibited subcutaneous-tumor-promoted lung premetastatic niche development and tumor metastasis.It inhibited the release of exosomes from tumor cells under hypoxic condition.JR treatment promoted both lysosomal acidification and suppressed secretory autophagy,which were dysregulated in hypoxic tumor cells.Quercetin was identified as the active component in JR,and the epidermal growth factor receptor(EGFR)was identified as a potential target.Quercetin inhibited EGFR phosphorylation and promoted the nuclear translocation of transcription factor EB(TFEB).Hypoxia-impaired lysosomal function was restored,and secretory autophagy was alleviated by quercetin treatment.Conclusion:JR suppressed HCC metastasis by inhibiting hypoxia-stimulated exosome release,restoring lysosomal function,and suppressing secretory autophagy.Quercetin acted as a key component of JR and regulated TDE release through EGFR-TFEB signaling.Our study provides a potential strategy for retarding tumor metastasis by targeting H-TDE secretion.

Tumor-derived exosomes induce initial activation by exosomal CD19 antigen but impair the function of CD19-specific CAR T-cells via TGF-βsignaling

Tumor-derived exosomes (TEXs) enriched in immune suppressive molecules predominantly drive T-cell dysfunction and impair antitumor immunity. Chimeric antigen receptor (CAR) T-cell therapy has emerged as a promising treatment for refractory and relapsed hematological malignancies, but whether lymphoma TEXs have the same impact on CAR T-cell remains unclear. Here, we demonstrated that B-cell lymphoma-derived exosomes induce the initial activation of CD19-CAR T-cells upon stimulation with exosomal CD19. However, lymphoma TEXs might subsequently induce CAR T-cell apoptosis and impair the tumor cytotoxicity of the cells because of the upregulated expression of the inhibitory receptors PD-1, TIM3, and LAG3 upon prolonged exposure. Similar results were observed in the CAR T-cells exposed to plasma exosomes from patients with lymphoma. More importantly, single-cell RNA sequencing revealed that CAR T-cells typically showed differentiated phenotypes and regulatory T-cell (Treg) phenotype conversion. By blocking transforming growth factor β (TGF-β)-Smad3 signaling with TGF-β inhibitor LY2109761, the negative effects of TEXs on Treg conversion, terminal differentiation, and immune checkpoint expression were rescued. Collectively, although TEXs lead to the initial activation of CAR T-cells, the effect of TEXs suppressed CAR T-cells, which can be rescued by LY2109761. A treatment regimen combining CAR T-cell therapy and TGF-β inhibitors might be a novel therapeutic strategy for refractory and relapsed B-cell lymphoma.

Tumor-derived exosomes:Nanovesicles made by cancer cells to promote cancer metastasis

Nanomedicine usually refers to nanoparticles that deliver the functional drugs and siRNAs to treat cancer.Recent research has suggested that cancer cells can also make nanoparticles that also deliver functional molecules in promoting cancer metastasis,which is the leading cause of various cancer mortalities.This nanoparticle is called tumor-derived vesicles,or better-known as tumor-derived exosomes(TEXs).TEXs are nanoscale membrane vesicles(30 e140 nm)that are released continuously by various types of cancer cells and contain tumor-derived functional biomolecules,including lipids,proteins,and genetic molecules.These endogenous TEXs can interact with host immune cells and epithelial cells locally and systemically.More importantly,they can reprogram the recipient cells in favor of promoting metastasis through facilitating tumor cell local invasion,intravasation,immune evasion,extravasation,and survival and growth in distant organs.Growing evidence suggests that TEXs play a key role in cancer metastasis.Here,we will review the most recent findings of how cancer cells harness TEXs to promote cancer metastasis through modulating vascular permeability,suppressing systemic immune surveillance,and creating metastatic niches.We will also summarize recent research in targeting TEXs to treat cancer metastasis.

Tumor-derived exosomes:immune properties and clinical application in lung cancer

Lung cancer is the leading cause of cancer-related death worldwide.Despite advances in diagnosis and treatment of lung cancer,the overall survival remains poor.Evidence indicates that lung cancer development is a complex and dynamic process that involves interactions between tumor cells and their microenvironments,including immune cells.Exosomes are small extracellular vesicles secreted by most cell types;they contain functional molecules that allow intercellular communication.Tumor-derived exosomes(TEXs)carry both immunosuppressive and immunostimulatory mediators and may be involved in various immunomodulatory effects.TEXs,which partially mimic profiles of the parent cells,are a potential source of cancer biomarkers for prognosis,diagnosis,and prediction of response to therapy.In addition,TEXs may interfere with immunotherapies,but they also could be used as adjuvants and antigenic components in vaccines against lung cancer.In the context of lung cancer,identifying TEXs and understanding their contribution to tumorigenesis and the response to immunotherapies represents a challenging research area.

Exosomes as promising frontier approaches in future cancer therapy

In this editorial,we will discuss the article by Tang et al published in the recent issue of the World Journal of Gastrointestinal Oncology.They explored an innovative approach to enhancing gemcitabine(GEM)delivery and efficacy using human bone marrow mesenchymal stem cells(HU-BMSCs)-derived exosomes.The manufacture of GEM-loaded HU-BMSCs-derived exosomes(Exo-GEM)has been optimized.The Tang et al’s study demonstrated that Exo-GEM exhibits enhanced cytotoxicity and apoptosis-inducing effects compared to free GEM,highlighting the potential of exosome-based drug delivery systems as a more effective and targeted approach to chemotherapy in pancreatic cancer.Additional in vivo studies are required to confirm the safety and effectiveness of Exo-GEM before it can be considered for clinical use.

Comparative proteomic analysis of plasma exosomes reveals the functional contribution of N-acetyl-alpha-glucosaminidase to Parkinson’s disease

Parkinson’s disease is the second most common progressive neurodegenerative disorder,and few reliable biomarkers are available to track disease progression.The proteins,DNA,mRNA,and lipids carried by exosomes reflect intracellular changes,and thus can serve as biomarkers for a variety of conditions.In this study,we investigated alterations in the protein content of plasma exosomes derived from patients with Parkinson’s disease and the potential therapeutic roles of these proteins in Parkinson’s disease.Using a tandem mass tag-based quantitative proteomics approach,we characterized the proteomes of plasma exosomes derived from individual patients,identified exosomal protein signatures specific to patients with Parkinson’s disease,and identified N-acetyl-alpha-glucosaminidase as a differentially expressed protein.N-acetyl-alpha-glucosaminidase expression levels in exosomes from the plasma of patients and healthy controls were validated by enzyme-linked immunosorbent assay and western blot.The results demonstrated that the exosomal N-acetyl-alpha-glucosaminidase concentration was not only lower in Parkinson’s disease,but also decreased with increasing Hoehn-Yahr stage,suggesting that N-acetyl-alpha-glucosaminidase could be used to rapidly evaluate Parkinson’s disease severity.Furthermore,western blot and immunohistochemistry analysis showed that N-acetyl-alpha-glucosaminidase levels were markedly reduced both in cells treated with 1-methyl-4-phenylpyridinium and cells overexpressingα-synuclein compared with control cells.Additionally,N-acetyl-alpha-glucosaminidase overexpression significantly increased cell viability and inhibitedα-synuclein expression in 1-methyl-4-phenylpyridinium-treated cells.Taken together,our findings demonstrate for the first time that exosomal N-acetyl-alpha-glucosaminidase may serve as a biomarker for Parkinson’s disease diagnosis,and that N-acetyl-alpha-glucosaminidase may reduceα-synuclein expression and 1-methyl-4-phenylpyridinium-induced neurotoxicity,thus providing a new therapeutic target for Parkinson’s disease.

Advances in therapies using mesenchymal stem cells and their exosomes for treatment of peripheral nerve injury:state of the art and future perspectives

“Peripheral nerve injury”refers to damage or trauma affecting nerves outside the brain and spinal cord.Peripheral nerve injury results in movements or sensation impairments,and represents a serious public health problem.Although severed peripheral nerves have been effectively joined and various therapies have been offered,recovery of sensory or motor functions remains limited,and efficacious therapies for complete repair of a nerve injury remain elusive.The emerging field of mesenchymal stem cells and their exosome-based therapies hold promise for enhancing nerve regeneration and function.Mesenchymal stem cells,as large living cells responsive to the environment,secrete various factors and exosomes.The latter are nano-sized extracellular vesicles containing bioactive molecules such as proteins,microRNA,and messenger RNA derived from parent mesenchymal stem cells.Exosomes have pivotal roles in cell-to-cell communication and nervous tissue function,offering solutions to changes associated with cell-based therapies.Despite ongoing investigations,mesenchymal stem cells and mesenchymal stem cell-derived exosome-based therapies are in the exploratory stage.A comprehensive review of the latest preclinical experiments and clinical trials is essential for deep understanding of therapeutic strategies and for facilitating clinical translation.This review initially explores current investigations of mesenchymal stem cells and mesenchymal stem cell-derived exosomes in peripheral nerve injury,exploring the underlying mechanisms.Subsequently,it provides an overview of the current status of mesenchymal stem cell and exosomebased therapies in clinical trials,followed by a comparative analysis of therapies utilizing mesenchymal stem cells and exosomes.Finally,the review addresses the limitations and challenges associated with use of mesenchymal stem cell-derived exosomes,offering potential solutions and guiding future directions.

Exosomes:the next-generation therapeutic platform for ischemic stroke

Current therapeutic strategies for ischemic stroke fall short of the desired objective of neurological functional recovery.Therefore,there is an urgent need to develop new methods for the treatment of this condition.Exosomes are natural cell-derived vesicles that mediate signal transduction between cells under physiological and pathological conditions.They have low immunogenicity,good stability,high delivery efficiency,and the ability to cross the blood–brain barrier.These physiological properties of exosomes have the potential to lead to new breakthroughs in the treatment of ischemic stroke.The rapid development of nanotechnology has advanced the application of engineered exosomes,which can effectively improve targeting ability,enhance therapeutic efficacy,and minimize the dosages needed.Advances in technology have also driven clinical translational research on exosomes.In this review,we describe the therapeutic effects of exosomes and their positive roles in current treatment strategies for ischemic stroke,including their antiinflammation,anti-apoptosis,autophagy-regulation,angiogenesis,neurogenesis,and glial scar formation reduction effects.However,it is worth noting that,despite their significant therapeutic potential,there remains a dearth of standardized characterization methods and efficient isolation techniques capable of producing highly purified exosomes.Future optimization strategies should prioritize the exploration of suitable isolation techniques and the establishment of unified workflows to effectively harness exosomes for diagnostic or therapeutic applications in ischemic stroke.Ultimately,our review aims to summarize our understanding of exosome-based treatment prospects in ischemic stroke and foster innovative ideas for the development of exosome-based therapies.

Human-induced pluripotent stem cell-derived neural stem cell exosomes improve blood-brain barrier function after intracerebral hemorrhage by activating astrocytes via PI3K/AKT/MCP-1 axis

Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor prognosis.Human-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system diseases.In this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying mechanism.Our results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral hemorrhage.Additionally,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory microenvironment.RNA sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier integrity.Treatment with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these effects.In summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes.

CAF-derived exosome-miR-3124-5p promotes malignant biological processes in NSCLC via the TOLLIP/TLR4-MyD88-NF-κB pathway

Background:Lung cancer is a life-threatening disease that occurs worldwide,but is especially common in China.The crucial role of the tumour microenvironment(TME)in non-small cell lung cancer(NSCLC)has attracted recent attention.Cancer-associated fibroblasts(CAFs)are the main factors that contribute to the TME function,and CAF exosomes are closely linked to NSCLC.Methods:The expression levels of miR-3124-5p and Toll-interacting protein(TOLLIP)were analysed by bioinformatics prediction combined with RT-qPCR/Western Blot detection.Fibroblasts were isolated and identified from clinical NSCLC tissues.Transmission electron microscopy and Western Blot were used to identify exosomes from these cells.Changes in proliferation(CCK-8 and clone formation),migration(wound healing),and invasion(transwell)of NSCLC cells were measured.The Luciferase reporter test was applied to clarify the binding of miR-3124-5p to TOLLIP.The TOLLIP/TLR4/MyD88/NF-κB pathway proteins were determined using Western blot analysis.Results:MiR-3124-5p is overexpressed in clinical tissues and cells of NSCLC.MiR-3124-5p was dramatically enriched in CAF-derived exosomes.Cellular experiments revealed that CAFs delivered miR-3124-5p into NSCLC cells via exosomes,stimulating cancer cell progression.MiR-3124-5p acted as a sponge to negatively regulate TOLLIP expression,which activated the TLR4/MyD88/NF-κB axis to promote the occurrence and development of NSCLC.Functional salvage tests were performed to determine whether CAF-exosome-derived miR-3124-5p plays a pro-cancer role in NSCLC by affecting the TOLLIP signalling pathway.Conclusions:These results provide an interesting direction for the diagnosis and therapy of NSCLC.

Exosomes originating from neural stem cells undergoing necroptosis participate in cellular communication by inducing TSC2 upregulation of recipient cells following spinal cord injury

We previously demonstrated that inhibiting neural stem cells necroptosis enhances functional recovery after spinal cord injury.While exosomes are recognized as playing a pivotal role in neural stem cells exocrine function,their precise function in spinal cord injury remains unclear.To investigate the role of exosomes generated following neural stem cells necroptosis after spinal cord injury,we conducted singlecell RNA sequencing and validated that neural stem cells originate from ependymal cells and undergo necroptosis in response to spinal cord injury.Subsequently,we established an in vitro necroptosis model using neural stem cells isolated from embryonic mice aged 16-17 days and extracted exosomes.The results showed that necroptosis did not significantly impact the fundamental characteristics or number of exosomes.Transcriptome sequencing of exosomes in necroptosis group identified 108 differentially expressed messenger RNAs,104 long non-coding RNAs,720 circular RNAs,and 14 microRNAs compared with the control group.Construction of a competing endogenous RNA network identified the following hub genes:tuberous sclerosis 2(Tsc2),solute carrier family 16 member 3(Slc16a3),and forkhead box protein P1(Foxp1).Notably,a significant elevation in TSC2 expression was observed in spinal cord tissues following spinal cord injury.TSC2-positive cells were localized around SRY-box transcription factor 2-positive cells within the injury zone.Furthermore,in vitro analysis revealed increased TSC2 expression in exosomal receptor cells compared with other cells.Further assessment of cellular communication following spinal cord injury showed that Tsc2 was involved in ependymal cellular communication at 1 and 3 days post-injury through the epidermal growth factor and midkine signaling pathways.In addition,Slc16a3 participated in cellular communication in ependymal cells at 7 days post-injury via the vascular endothelial growth factor and macrophage migration inhibitory factor signaling pathways.Collectively,these findings confirm that exosomes derived from neural stem cells undergoing necroptosis play an important role in cellular communication after spinal cord injury and induce TSC2 upregulation in recipient cells.

Bridging bioengineering and nanotechnology: Bone marrow derived mesenchymal stem cell-exosome solutions for peripheral nerve injury

Peripheral nerve injury(PNI)is a common disease that is difficult to nerve regeneration with current therapies.Fortunately,Zou et al demonstrated the role and mechanism of bone marrow derived mesenchymal stem cells(BMSCs)in promoting nerve regeneration,revealing broad prospects for BMSCs trans-plantation in alleviating PNI.We confirmed the fact that BMSCs significantly alleviate PNI,but there are shortcomings such as low cell survival rate and immune rejection,which limit the wide application of BMSCs.BMSCs-derived exosomes(Exos)are considered as a promising cell-free nanomedicine for PNI,avoiding the ethical issues of BMSCs.Exos in combination with bioengineering therapeutics(including extracellular matrix,hydrogel)brings new hope for PNI,provides a favorable microenvironment for neurological restoration and a therapeutic strategy with a favorable safety profile,significantly increases ex-pression of neurotrophic factors,promotes axonal and myelin regeneration,and demonstrates a strong potential to enhance neurogenesis.Therefore,engineered Exos exhibit better properties,such as stronger targeting and more beneficial components.This article briefly describes the role of nanotechnology and bioe-ngineering therapies for BMSCs in PNI,proposes clinical application prospects and challenges of nanotechnology and bioengineering BMSCs-derived Exos in PNI to improve the efficacy of BMSCs in the treatment of PNI.

Pathogenic and therapeutic role of exosomes in neurodegenerative disorders

Neurodegenerative disorders affect millions of people worldwide,and the prevalence of these disorders is only projected to rise as the number of people over 65 will drastically increase in the coming years.While therapies exist to aid in symptomatic relief,effective treatments that can stop or reve rse the progress of each neurodegenerative disease are lacking.Recently,research on the role of extracellular vesicles as disease markers and therapeutics has been intensively studied.Exosomes,30-150 nm in diameter,are one type of extracellular vesicles facilitating cell-to-cell communication.Exosomes are thought to play a role in disease propagation in a variety of neurodegenerative diseases,such as Alzheimer's disease,Parkinson s disease,and amyotrophic lateral sclerosis.Accordingly,the exosomes derived from the patients are an invaluable source of disease biomarkers.On the other hand,exosomes,especially those derived from stem cells,could serve as a therapeutic for these disorders,as seen by a rapid increase in clinical trials investigating the therapeutic efficacy of exosomes in different neurological diseases.This review summarizes the pathological burden and therapeutic approach of exosomes in neurodegenerative disorders.We also highlight how heat shock increases the yield of exosomes while still maintaining their therapeutic efficacy.Finally,this review concludes with outstanding questions that remain to be addressed in exosomal research.

Emerging role of exosomes in ulcerative colitis: Targeting NOD-like receptor family pyrin domain containing 3 inflammasome

Ulcerative colitis(UC)is a chronic recurrent inflammatory bowel disease.Despite ongoing advances in our understanding of UC,its pathogenesis is yet unelu-cidated,underscoring the urgent need for novel treatment strategies for patients with UC.Exosomes are nanoscale membrane particles that mediate intercellular communication by carrying various bioactive molecules,such as proteins,RNAs,DNA,and metabolites.The NOD-like receptor family pyrin domain containing 3(NLRP3)inflammasome is a cytosolic tripartite protein complex whose activation induces the maturation and secretion of proinflammatory cytokines interleukin-1β(IL-1β)and IL-18,triggering the inflammatory response to a pathogenic agent or injury.Growing evidence suggests that exosomes are new modulators of the NLRP3 inflammasome,with vital roles in the pathological process of UC.Here,recent evidence is reviewed on the role of exosomes and NLRP3 inflammasome in UC.First,the dual role of exosomes on NLRP3 inflammasome and the effect of NLRP3 inflammasome on exosome secretion are summarized.Finally,an outlook on the directions of exosome-NLRP3 inflammasome crosstalk research in the context of UC is proposed and areas of further research on this topic are high-lighted.

Intranasal administration of stem cell-derived exosomes for central nervous system diseases

Exosomes,lipid bilayer-enclosed small cellular vesicles,are actively secreted by various cells and play crucial roles in intercellular communication.These nanosized vesicles transport internalized proteins,mRNA,miRNA,and other bioactive molecules.Recent findings have provided compelling evidence that exosomes derived from stem cells hold great promise as a therapeutic modality for central nervous system disorders.These exosomes exhibit multifaceted properties including antiapoptotic,anti-inflammatory,neurogenic,and vasculogenic effects.Furthermore,exosomes offer several advantages over stem cell therapy,such as high preservation capacity,low immunogenicity,the ability to traverse the blood-brain barrier,and the potential for drug encapsulation.Consequently,researchers have turned their attention to exosomes as a novel therapeutic avenue.Nonetheless,akin to the limitations of stem cell treatment,the limited accumulation of exosomes in the injured brain poses a challenge to their clinical application.To overcome this hurdle,intranasal administration has emerged as a non-invasive and efficacious route for delivering drugs to the central nervous system.By exploiting the olfactory and trigeminal nerve axons,this approach enables the direct transport of therapeutics to the brain while bypassing the blood-brain barrier.Notably,exosomes,owing to their small size,can readily access the nerve pathways using this method.As a result,intranasal administration has gained increasing recognition as an optimal therapeutic strategy for exosomebased treatments.In this comprehensive review,we aim to provide an overview of both basic and clinical research studies investigating the intranasal administration of exosomes for the treatment of central nervous system diseases.Furthermore,we elucidate the underlying therapeutic mechanisms and offer insights into the prospect of this approach.

Effects of exosomes from mesenchymal stem cells on functional recovery of a patient with total radial nerve injury: A pilot study

BACKGROUND Peripheral nerve injury can result in significant clinical complications that have uncertain prognoses.Currently,there is a lack of effective pharmacological interventions for nerve damage,despite the existence of several small compounds,Despite the objective of achieving full functional restoration by surgical intervention,the persistent challenge of inadequate functional recovery remains a significant concern in the context of peripheral nerve injuries.AIM To examine the impact of exosomes on the process of functional recovery following a complete radial nerve damage.METHODS A male individual,aged 24,who is right-hand dominant and an immigrant,arrived with an injury caused by a knife assault.The cut is located on the left arm,specifically below the elbow.The neurological examination and electrodiagnostic testing reveal evidence of left radial nerve damage.The sural autograft was utilized for repair,followed by the application of 1 mL of mesenchymal stem cell-derived exosome,comprising 5 billion microvesicles.This exosome was split into four equal volumes of 0.25 mL each and delivered microsurgically to both the proximal and distal stumps using the subepineural pathway.The patient was subjected to a period of 180 d during which they had neurological examination and electrodiagnostic testing.RESULTS The duration of the patient’s follow-up period was 180 d.An increasing Tinel’s sign and sensory-motor recovery were detected even at the 10th wk following nerve grafting.Upon the conclusion of the 6-mo post-treatment period,an evaluation was conducted to measure the extent of improvement in motor and sensory functions of the nerve.This assessment was based on the British Medical Research Council scale and the Mackinnon-Dellon scale.The results indicated that the level of improvement in motor function was classified as M5,denoting an excellent outcome.Additionally,the level of improvement in sensory function was classified as S3+,indicating a good outcome.It is noteworthy that these assessments were conducted in the absence of physical therapy.At the 10th wk post-injury,despite the persistence of substantial axonal damage,the nerve exhibited indications of nerve re-innervation as evidenced by control electromyography(EMG).In contrast to the preceding.EMG analysis revealed a significant electrophysiological enhancement in the EMG conducted at the 6th-mo follow-up,indicating ongoing regeneration.CONCLUSION Enhanced comprehension of the neurobiological ramifications associated with peripheral nerve damage,as well as the experimental and therapy approaches delineated in this investigation,holds the potential to catalyze future clinical progress.

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.

Neural stem cell-derived exosomes regulate cell proliferation,migration,and cell death of brain microvascular endothelial cells via the miR-9/Hes1 axis under hypoxia

Background:Our previous study found that mouse embryonic neural stem cell(NSC)-derived exosomes(EXOs)regulated NSC differentiation via the miR-9/Hes1 axis.However,the effects of EXOs on brain microvascular endothelial cell(BMEC)dysfunction via the miR-9/Hes1 axis remain unknown.Therefore,the current study aimed to determine the effects of EXOs on BMEC proliferation,migration,and death via the miR-9/Hes1 axis.Methods:Immunofluorescence,quantitative real-time polymerase chain reaction,cell counting kit-8 assay,wound healing assay,calcein-acetoxymethyl/propidium iodide staining,and hematoxylin and eosin staining were used to determine the role and mechanism of EXOs on BMECs.Results:EXOs promoted BMEC proliferation and migration and reduced cell death under hypoxic conditions.The overexpression of miR-9 promoted BMEC prolifera-tion and migration and reduced cell death under hypoxic conditions.Moreover,miR-9 downregulation inhibited BMEC proliferation and migration and also promoted cell death.Hes1 silencing ameliorated the effect of amtagomiR-9 on BMEC proliferation and migration and cell death.Hyperemic structures were observed in the regions of the hippocampus and cortex in hypoxia-induced mice.Meanwhile,EXO treatment improved cerebrovascular alterations.Conclusion:NSC-derived EXOs can promote BMEC proliferation and migra-tion and reduce cell death via the miR-9/Hes1 axis under hypoxic conditions.Therefore,EXO therapeutic strategies could be considered for hypoxia-induced vascular injury.