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White KE, Bailey HL, Shaw BS, Geiszler PC, Mesquita-Ribeiro R, Scott D, Layfield R, Serres S. A convenient model of serum-induced reactivity of human astrocytes to investigate astrocyte-derived extracellular vesicles. Front Cell Neurosci 2024; 18:1414142. [PMID: 38915876 PMCID: PMC11195030 DOI: 10.3389/fncel.2024.1414142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 05/17/2024] [Indexed: 06/26/2024] Open
Abstract
Extracellular vesicles (EVs) are secreted by all cells in the CNS, including neurons and astrocytes. EVs are lipid membrane enclosed particles loaded with various bioactive cargoes reflecting the dynamic activities of cells of origin. In contrast to neurons, the specific role of EVs released by astrocytes is less well understood, partly due to the difficulty in maintaining primary astrocyte cultures in a quiescent state. The aim of this study was to establish a human serum-free astrocyte culture system that maintains primary astrocytes in a quiescent state to study the morphology, function, and protein cargoes of astrocyte-derived EVs. Serum-free medium with G5 supplement and serum-supplemented medium with 2% FBS were compared for the culture of commercially available human primary fetal astrocytes. Serum-free astrocytes displayed morphologies similar to in vivo astrocytes, and surprisingly, higher levels of astrocyte markers compared to astrocytes chronically cultured in FBS. In contrast, astrocyte and inflammatory markers in serum-free astrocytes were upregulated 24 h after either acute 2% FBS or cytokine exposure, confirming their capacity to become reactive. Importantly, this suggests that distinct signaling pathways are involved in acute and chronic astrocyte reactivity. Despite having a similar morphology, chronically serum-cultured astrocyte-derived EVs (ADEVs) were smaller in size compared to serum-free ADEVs and could reactivate serum-free astrocytes. Proteomic analysis identified distinct protein datasets for both types of ADEVs with enrichment of complement and coagulation cascades for chronically serum-cultured astrocyte-derived EVs, offering insights into their roles in the CNS. Collectively, these results suggest that human primary astrocytes cultured in serum-free medium bear similarities with in vivo quiescent astrocytes and the addition of serum induces multiple morphological and transcriptional changes that are specific to human reactive astrocytes and their ADEVs. Thus, more emphasis should be made on using multiple structural, molecular, and functional parameters when evaluating ADEVs as biomarkers of astrocyte health.
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Affiliation(s)
- Katherine E. White
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Hannah L. Bailey
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Barry S. Shaw
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | | | | | - Daniel Scott
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Robert Layfield
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Sébastien Serres
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- The David Greenfield Human Physiology Unit, University of Nottingham, Nottingham, United Kingdom
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Jiang S, Li X, Li Y, Chang Z, Yuan M, Zhang Y, Zhu H, Xiu Y, Cong H, Yin L, Yu ZW, Fan J, He W, Shi K, Tian DC, Zhang J, Verkhratsky A, Jin WN, Shi FD. APOE from patient-derived astrocytic extracellular vesicles alleviates neuromyelitis optica spectrum disorder in a mouse model. Sci Transl Med 2024; 16:eadg5116. [PMID: 38416841 DOI: 10.1126/scitranslmed.adg5116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 02/07/2024] [Indexed: 03/01/2024]
Abstract
Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune astrocytopathy of the central nervous system, mediated by antibodies against aquaporin-4 water channel protein (AQP4-Abs), resulting in damage of astrocytes with subsequent demyelination and axonal damage. Extracellular communication through astrocyte-derived extracellular vesicles (ADEVs) has received growing interest in association with astrocytopathies. However, to what extent ADEVs contribute to NMOSD pathogenesis remains unclear. Here, through proteomic screening of patient-derived ADEVs, we observed an increase in apolipoprotein E (APOE)-rich ADEVs in patients with AQP4-Abs-positive NMOSD. Intracerebral injection of the APOE-mimetic peptide APOE130-149 attenuated microglial reactivity, neuroinflammation, and brain lesions in a mouse model of NMOSD. The protective effect of APOE in NMOSD pathogenesis was further established by the exacerbated lesion volume in APOE-deficient mice, which could be rescued by exogenous APOE administration. Genetic knockdown of the APOE receptor lipoprotein receptor-related protein 1 (LRP1) could block the restorative effects of APOE130-149 administration. The transfusion ADEVs derived from patients with NMOSD and healthy controls also alleviated astrocyte loss, reactive microgliosis, and demyelination in NMOSD mice. The slightly larger beneficial effect of patient-derived ADEVs as compared to ADEVs from healthy controls was further augmented in APOE-/- mice. These results indicate that APOE from astrocyte-derived extracellular vesicles could mediate disease-modifying astrocyte-microglia cross-talk in NMOSD.
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Affiliation(s)
- Shihe Jiang
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Xindi Li
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Yan Li
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Zhilin Chang
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Meng Yuan
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Ying Zhang
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Huimin Zhu
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Yuwen Xiu
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Hengri Cong
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Linlin Yin
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Zhen-Wei Yu
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Junwan Fan
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Wenyan He
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Kaibin Shi
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - De-Cai Tian
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Jing Zhang
- Department of Pathology, First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310002, China
- National Human Brain Bank for Health and Disease, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310002, China
| | - Alexei Verkhratsky
- Health and Medicine, University of Manchester, Manchester M13 9PL, UK
- Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
| | - Wei-Na Jin
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Fu-Dong Shi
- Department of Neurology, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
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Kumar A, Nader MA, Deep G. Emergence of Extracellular Vesicles as "Liquid Biopsy" for Neurological Disorders: Boom or Bust. Pharmacol Rev 2024; 76:199-227. [PMID: 38351075 PMCID: PMC10877757 DOI: 10.1124/pharmrev.122.000788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 11/11/2023] [Accepted: 11/27/2023] [Indexed: 02/16/2024] Open
Abstract
Extracellular vesicles (EVs) have emerged as an attractive liquid biopsy approach in the diagnosis and prognosis of multiple diseases and disorders. The feasibility of enriching specific subpopulations of EVs from biofluids based on their unique surface markers has opened novel opportunities to gain molecular insight from various tissues and organs, including the brain. Over the past decade, EVs in bodily fluids have been extensively studied for biomarkers associated with various neurological disorders, such as Alzheimer's disease, Parkinson's disease, schizophrenia, bipolar disorder, major depressive disorders, substance use disorders, human immunodeficiency virus-associated neurocognitive disorder, and cancer/treatment-induced neurodegeneration. These studies have focused on the isolation and cargo characterization of either total EVs or brain cells, such as neuron-, astrocyte-, microglia-, oligodendrocyte-, pericyte-, and endothelial-derived EVs from biofluids to achieve early diagnosis and molecular characterization and to predict the treatment and intervention outcomes. The findings of these studies have demonstrated that EVs could serve as a repetitive and less invasive source of valuable molecular information for these neurological disorders, supplementing existing costly neuroimaging techniques and relatively invasive measures, like lumbar puncture. However, the initial excitement surrounding blood-based biomarkers for brain-related diseases has been tempered by challenges, such as lack of central nervous system specificity in EV markers, lengthy protocols, and the absence of standardized procedures for biological sample collection, EV isolation, and characterization. Nevertheless, with rapid advancements in the EV field, supported by improved isolation methods and sensitive assays for cargo characterization, brain cell-derived EVs continue to offer unparallel opportunities with significant translational implications for various neurological disorders. SIGNIFICANCE STATEMENT: Extracellular vesicles present a less invasive liquid biopsy approach in the diagnosis and prognosis of various neurological disorders. Characterizing these vesicles in biofluids holds the potential to yield valuable molecular information, thereby significantly impacting the development of novel biomarkers for various neurological disorders. This paper has reviewed the methodology employed to isolate extracellular vesicles derived from various brain cells in biofluids, their utility in enhancing the molecular understanding of neurodegeneration, and the potential challenges in this research field.
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Affiliation(s)
- Ashish Kumar
- Departments of Cancer Biology (A.K., G.D.), Physiology and Pharmacology (M.A.N.), Radiology (M.A.N.), and Center for Addiction Research (M.A.N., G.D.), Wake Forest University School of Medicine, Winston-Salem, North Carolina; Atrium Health Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina (G.D.); and Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina (G.D.)
| | - Michael A Nader
- Departments of Cancer Biology (A.K., G.D.), Physiology and Pharmacology (M.A.N.), Radiology (M.A.N.), and Center for Addiction Research (M.A.N., G.D.), Wake Forest University School of Medicine, Winston-Salem, North Carolina; Atrium Health Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina (G.D.); and Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina (G.D.)
| | - Gagan Deep
- Departments of Cancer Biology (A.K., G.D.), Physiology and Pharmacology (M.A.N.), Radiology (M.A.N.), and Center for Addiction Research (M.A.N., G.D.), Wake Forest University School of Medicine, Winston-Salem, North Carolina; Atrium Health Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina (G.D.); and Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina (G.D.)
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Miron RJ, Zhang Y. Understanding exosomes: Part 1-Characterization, quantification and isolation techniques. Periodontol 2000 2024; 94:231-256. [PMID: 37740431 DOI: 10.1111/prd.12520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 09/24/2023]
Abstract
Exosomes are the smallest subset of extracellular signaling vesicles secreted by most cells with a diameter in the range of 30-150 nm. Their use has gained great momentum recently due to their ability to be utilized as diagnostic tools with a vast array of therapeutic applications. Over 5000 publications are currently being published yearly on this topic, and this number is only expected to dramatically increase as novel therapeutic strategies continue to be investigated. This review article first focuses on understanding exosomes, including their cellular origin, biogenesis, function, and characterization. Thereafter, overviews of the quantification methods and isolation techniques are given with discussion over their potential use as novel therapeutics in regenerative medicine.
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Affiliation(s)
- Richard J Miron
- Department of Periodontology, University of Bern, Bern, Switzerland
| | - Yufeng Zhang
- Department of Oral Implantology, University of Wuhan, Wuhan, China
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Filannino FM, Panaro MA, Benameur T, Pizzolorusso I, Porro C. Extracellular Vesicles in the Central Nervous System: A Novel Mechanism of Neuronal Cell Communication. Int J Mol Sci 2024; 25:1629. [PMID: 38338906 PMCID: PMC10855168 DOI: 10.3390/ijms25031629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/21/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
Cell-to-cell communication is essential for the appropriate development and maintenance of homeostatic conditions in the central nervous system. Extracellular vesicles have recently come to the forefront of neuroscience as novel vehicles for the transfer of complex signals between neuronal cells. Extracellular vesicles are membrane-bound carriers packed with proteins, metabolites, and nucleic acids (including DNA, mRNA, and microRNAs) that contain the elements present in the cell they originate from. Since their discovery, extracellular vesicles have been studied extensively and have opened up new understanding of cell-cell communication; they may cross the blood-brain barrier in a bidirectional way from the bloodstream to the brain parenchyma and vice versa, and play a key role in brain-periphery communication in physiology as well as pathology. Neurons and glial cells in the central nervous system release extracellular vesicles to the interstitial fluid of the brain and spinal cord parenchyma. Extracellular vesicles contain proteins, nucleic acids, lipids, carbohydrates, and primary and secondary metabolites. that can be taken up by and modulate the behaviour of neighbouring recipient cells. The functions of extracellular vesicles have been extensively studied in the context of neurodegenerative diseases. The purpose of this review is to analyse the role extracellular vesicles extracellular vesicles in central nervous system cell communication, with particular emphasis on the contribution of extracellular vesicles from different central nervous system cell types in maintaining or altering central nervous system homeostasis.
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Affiliation(s)
| | - Maria Antonietta Panaro
- Department of Biosciences, Biotechnologies and Environment, University of Bari, 70125 Bari, Italy;
| | - Tarek Benameur
- Department of Biomedical Sciences, College of Medicine, King Faisal University, Al-Ahsa 31982, Saudi Arabia;
| | - Ilaria Pizzolorusso
- Child and Adolescent Neuropsychiatry Unit, Department of Mental Health, ASL Foggia, 71121 Foggia, Italy;
| | - Chiara Porro
- Department of Clinical and Experimental Medicine, University of Foggia, 71121 Foggia, Italy;
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Hou Y, Xie Y, Liu X, Chen Y, Zhou F, Yang B. Oxygen glucose deprivation-pretreated astrocyte-derived exosomes attenuates intracerebral hemorrhage (ICH)-induced BBB disruption through miR-27a-3p /ARHGAP25/Wnt/β-catenin axis. Fluids Barriers CNS 2024; 21:8. [PMID: 38243347 PMCID: PMC10799414 DOI: 10.1186/s12987-024-00510-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 01/05/2024] [Indexed: 01/21/2024] Open
Abstract
BACKGROUND Blood brain barrier (BBB) breakdown is one of the key mechanisms of secondary brain injury following intracerebral hemorrhage (ICH). Astrocytes interact with endothelial and regulate BBB integrity via paracrine signaling factors. More and more studies reveal astrocyte-derived extracellular vesicles (ADEVs) as an important way of intercellular communication. However, the role of ADEV in BBB integrity after ICH remains unclear. METHODS ADEVs were obtained from astrocytes with or without oxygen and glucose deprivation (OGD) pre-stimulation and the role of ADEVs in ICH was investigated using ICH mice model and ICH cell model. The potential regulatory effect of ADEVs on endothelial barrier integrity was identified by TEER, western blot and immunofluorescence in vitro. In vivo, functional evaluation, Evans-blue leakage and tight junction proteins (TJPs) expression were analyzed. MiRNA sequencing revealed that microRNA-27a-3p (miR-27a-3p) was differentially expressed miRNA in the EVs from OGD-pretreated astrocytes compared with normal control. The regulatory mechanism of miR-27a-3p was assessed using Luciferase assay, RT-PCR, western blot and immunofluorescence. RESULTS OGD-activated astrocytes reduced hemin-induced endothelial hyper-permeability through secreting EVs. OGD-activated ADEVs alleviated BBB dysfunction after ICH in vivo and in vitro. MicroRNA microarray analysis indicated that miR-27a-3p is a major component that was highly expressed miRNA in OGD pretreated-ADEVs. OGD-ADEVs mitigated BBB injury through transferring miR-27a-3p into bEnd.3 cells and regulating ARHGAP25/Wnt/β-catenin pathway. CONCLUSION Taken together, these findings firstly revealed that miR-27a-3p, as one of the main components of OGD-pretreated ADEVs, attenuated BBB destruction and improved neurological deficits following ICH by regulating endothelial ARHGAP25/Wnt/β-catenin axis. OGD-ADEVs might be a novel strategy for the treatment of ICH. this study implicates that EVs from OGD pre-stimulated astrocytes.
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Affiliation(s)
- Ying Hou
- Department of Neurology, 2nd Xiangya Hospital, Central South University, No. 139, Middle Renmin Road, Changsha, Hunan, China
| | - Ye Xie
- Department of Neurology, 2nd Xiangya Hospital, Central South University, No. 139, Middle Renmin Road, Changsha, Hunan, China
| | - Xiaoxuan Liu
- Department of Neurology, 2nd Xiangya Hospital, Central South University, No. 139, Middle Renmin Road, Changsha, Hunan, China
| | - Yushan Chen
- Department of Neurology, 2nd Xiangya Hospital, Central South University, No. 139, Middle Renmin Road, Changsha, Hunan, China
| | - Fangfang Zhou
- Department of Neurology, 2nd Xiangya Hospital, Central South University, No. 139, Middle Renmin Road, Changsha, Hunan, China
| | - Binbin Yang
- Department of Neurology, 2nd Xiangya Hospital, Central South University, No. 139, Middle Renmin Road, Changsha, Hunan, China.
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Liu Z, Zhang H, Liu S, Hou Y, Chi G. The Dual Role of Astrocyte-Derived Exosomes and Their Contents in the Process of Alzheimer's Disease. J Alzheimers Dis 2023; 91:33-42. [PMID: 36373321 DOI: 10.3233/jad-220698] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Millions of patients worldwide are affected by Alzheimer's disease (AD), and the number of patients with AD is increasing. However, current treatment can only improve symptoms but cannot cure the disease. Astrocytes, glial cells in the central nervous system, play important roles in support, nutrition, protection, and information transmission in the nervous system. Pathological changes in astrocytes are closely associated with the development and progression of AD. As carriers for material and information exchange between astrocytes and other neural cells, astrocyte-derived exosomes (ADEs) have been widely studied in recent years, and ADE secretion has been shown to be increased in patients with AD and animal models of AD. ADEs contain a variety of substances, including nucleic acids, proteins, and lipids. The contents of ADEs can effectively control oxidative stress and detoxification during the early development of AD, thereby playing positive and negative roles in the occurrence and development of AD. In this review, we elaborate on the functions of ADEs and their components in AD and discuss their applications in AD research and clinical practice.
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Affiliation(s)
- Ziyu Liu
- Department of Regenerative Medicine, School of Pharmaceutical Science, Jilin University, Changchun, China
| | - Haotian Zhang
- Department of Regenerative Medicine, School of Pharmaceutical Science, Jilin University, Changchun, China
| | - Shiji Liu
- Department of Regenerative Medicine, School of Pharmaceutical Science, Jilin University, Changchun, China
| | - Yi Hou
- Department of Regenerative Medicine, School of Pharmaceutical Science, Jilin University, Changchun, China
| | - Guangfan Chi
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, China
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The dual action of glioma-derived exosomes on neuronal activity: synchronization and disruption of synchrony. Cell Death Dis 2022; 13:705. [PMID: 35963860 PMCID: PMC9376103 DOI: 10.1038/s41419-022-05144-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 06/28/2022] [Accepted: 07/28/2022] [Indexed: 01/21/2023]
Abstract
Seizures represent a frequent symptom in gliomas and significantly impact patient morbidity and quality of life. Although the pathogenesis of tumor-related seizures is not fully understood, accumulating evidence indicates a key role of the peritumoral microenvironment. Brain cancer cells interact with neurons by forming synapses with them and by releasing exosomes, cytokines, and other small molecules. Strong interactions among neurons often lead to the synchronization of their activity. In this paper, we used an in vitro model to investigate the role of exosomes released by glioma cell lines and by patient-derived glioma stem cells (GSCs). The addition of exosomes released by U87 glioma cells to neuronal cultures at day in vitro (DIV) 4, when neurons are not yet synchronous, induces synchronization. At DIV 7-12 neurons become highly synchronous, and the addition of the same exosomes disrupts synchrony. By combining Ca2+ imaging, electrical recordings from single neurons with patch-clamp electrodes, substrate-integrated microelectrode arrays, and immunohistochemistry, we show that synchronization and de-synchronization are caused by the combined effect of (i) the formation of new neuronal branches, associated with a higher expression of Arp3, (ii) the modification of synaptic efficiency, and (iii) a direct action of exosomes on the electrical properties of neurons, more evident at DIV 7-12 when the threshold for spike initiation is significantly reduced. At DIV 7-12 exosomes also selectively boost glutamatergic signaling by increasing the number of excitatory synapses. Remarkably, de-synchronization was also observed with exosomes released by glioma-associated stem cells (GASCs) from patients with low-grade glioma but not from patients with high-grade glioma, where a more variable outcome was observed. These results show that exosomes released from glioma modify the electrical properties of neuronal networks and that de-synchronization caused by exosomes from low-grade glioma can contribute to the neurological pathologies of patients with brain cancers.
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