Activated microglia can suppress neurite outgrowth and synapse recovery in the acute stage following traumatic brain injury (TBI). However, the underlying mechanism has not been clearly elucidated. Exosomes derived from microglia have been reported to play a critical role in microglia-neuron interaction in healthy and pathological brains. Here, we aimed to investigate the role of microglia-derived exosomes in regulating neurite outgrowth and synapse recovery following TBI. In our study, exosomes derived from microglia were co-cultured with stretch-injured neurons in vitro and intravenously injected into mice that underwent fluid percussion injury (FPI) by tail vein injection in vivo. The results showed that microglia-derived exosomes could be absorbed by neurons in vitro and in vivo. Moreover, exosomes derived from stretch-injured microglia decreased the protein levels of GAP43, PSD-95, GluR1, and Synaptophysin and dendritic complexity in stretch-injured neurons in vitro, and reduced GAP43+ NEUN cell percentage and apical dendritic spine density in the pericontusion region in vivo. Motor coordination was also impaired in mice treated with stretch-injured microglia-derived exosomes after FPI. A microRNA microarray showed that the level of miR-5121 was decreased most greatly in exosomes derived from stretch-injured microglia. Overexpression of miR-5121 in stretch-injured microglia-derived exosomes partly reversed the suppression of neurite outgrowth and synapse recovery of neurons both in vitro and in vivo. Moreover, motor coordination in miR-5121 overexpressed exosomes treated mice was significantly improved after FPI. Following mechanistic study demonstrated that miR-5121 might promote neurite outgrowth and synapse recovery by directly targeting RGMa. In conclusion, our finding revealed a novel exosome-mediated mechanism of microglia-neuron interaction that suppressed neurite outgrowth and synapse recovery of neurons following TBI.
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http://dx.doi.org/10.1007/s13311-020-00999-z | DOI Listing |
Bio Protoc
January 2025
Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan.
Primary neuronal culture and transient transfection offer a pair of crucial tools for neuroscience research, providing a controlled environment to study the behavior, function, and interactions of neurons in vitro. These cultures can be used to investigate fundamental aspects of neuronal development and plasticity, as well as disease mechanisms. There are numerous methods of transient transfection, such as electroporation, calcium phosphate precipitation, or cationic lipid transfection.
View Article and Find Full Text PDFIntroduction: Neurotrophic factors are widely known for their protective effect on spiral ganglion neurons (SGN) and the protection of these neurons is of great importance to optimize Cochlear Implants, which directly stimulate SGN in deaf patients. Previous studies have identified Cometin - also known as Meteroin-like - to be neuroprotective and beneficial for metabolic disorders. The aim of our study was to investigate the effects of different concentrations of recombinant human Cometin (hCometin) on SGN in regard to neuroprotection and neurite outgrowth and to evaluate its neurite guidance potential using a neurite outgrowth chamber.
View Article and Find Full Text PDFTransl Psychiatry
January 2025
Department of Neuropsychiatry, Dongguk University, School of Medicine, Seoul, Republic of Korea.
Autism spectrum disorder (ASD) is linked to ion channel dysfunction, including chloride voltage-gated channel-4 (CLCN4). We generated Clcn4 knockout (KO) mice by deleting exon 5 of chromosome 7 in the C57BL/6 mice. Clcn4 KO exhibited reduced social interaction and increased repetitive behaviors assessed using three-chamber and marble burying tests.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Spinal Surgery, The Third Affiliated Hospital of Soochow University, Changzhou 213000, Jiangsu, People's Republic of China. Electronic address:
After spinal cord injury (SCI), reactive astrocytes in the injured area are triggered after spinal cord injury (SCI) and to polarize into A1 astrocytes with a proinflammatory phenotype or A2 astrocytes with an anti-inflammatory phenotype. Monopolar spindle binder 2 (MOB2) induces astrocyte stellation, maintains cell homeostasis, and promotes neurite outgrowth; however, its role in the phenotypic transformation of reactive astrocytes remains unclear. Here, we confirmed for the first time that MOB2 is associated with A1/A2 phenotypic switching in reactive astrocytes following SCI in mice.
View Article and Find Full Text PDFBrain Sci
December 2024
Department of Anatomy, College of Medicine, Inje University, Busan 47392, Republic of Korea.
Background/objectives: α-Synuclein (α-syn) protein is a major pathological agent of familial Parkinson's disease (PD), and its levels and aggregations determine neurotoxicity in PD pathogenesis. Although the pathophysiological functions of α-syn have been extensively studied, its biological functions remain elusive, and there are reports of wild-type (WT) α-syn and two missense mutations of α-syn (A30P and A53T) inducing protective neuritogenesis through neurite outgrowth. However, the function of another α-syn mutation, E46K, has not been fully elucidated.
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