Related Experiment Video
Updated: Nov 8, 2025
Characterization and Isolation of Mouse Primary Microglia by Density Gradient Centrifugation
Published on: February 16, 2018
Extracellular vesicles derived from M2 microglia reduce ischemic brain injury through microRNA-135a-5p/TXNIP/NLRP3
Yue Liu1, You-Ping Li1, Li-Min Xiao1
1Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, PR China.
Abstract:
Accumulating evidences have suggested that extracellular vesicles (EVs) are crucial players in the pathogenesis of ischemic brain injury. This study was designed to explore the specific functions of M2 phenotype microglia-derived EVs in ischemic brain injury progression. The expression of microRNA-135a-5p (miR-135a-5p) in M2 microglia-derived EVs was determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), followed by the identification of expression relationship among miR-135a-5p, thioredoxin-interacting protein (TXNIP), and nod-like receptor protein 3 (NLRP3) by dual luciferase reporter gene assay. After construction of an oxygen-glucose deprivation/reperfusion (OGD/R) cell model, the effects of miR-135a-5p on the biological characteristics of HT-22 cells were assessed by cell counting kit 8 (CCK-8) assay and flow cytometry. Finally, a mouse model of transient middle cerebral artery occlusion (tMCAO) was established and cerebral infarction volume was determined by triphenyltetrazolium chloride (TTC) staining and the expression of IL-18 and IL-1β in the brain tissue was determined by enzyme-linked immunosorbent assay (ELISA). We found that M2 microglia-derived EVs had high expression of miR-135a-5p, and that miR-135a-5p in M2 microglia-derived EVs negatively regulated the expression of NLRP3 via TXNIP. Overexpression of miR-135a-5p promoted the proliferation but inhibited the apoptosis of neuronal cells, and inhibited the expression of autophagy-related proteins. M2 microglia-derived EVs delivered miR-135a-5p into neuronal cells to inhibit TXNIP expression, which further inhibited the activation of NLRP3 inflammasome, thereby reducing neuronal autophagy and ischemic brain injury. Hence, M2 microglia-derived EVs are novel therapeutic targets for ischemic brain injury treatment.
Insights
M2 microglia-derived extracellular vesicles (EVs) deliver microRNA-135a-5p to reduce ischemic brain injury by inhibiting NLRP3 inflammasome activation and neuronal autophagy. These EVs represent a promising therapeutic target for stroke treatment.
Area of Science:
- Neuroscience
- Cell Biology
- Biochemistry
Background:
- Extracellular vesicles (EVs) are implicated in ischemic brain injury pathogenesis.
- M2 phenotype microglia-derived EVs warrant investigation for their specific roles.
Purpose of the Study:
- To investigate the function of M2 microglia-derived EVs in ischemic brain injury.
- To determine the role of microRNA-135a-5p (miR-135a-5p) within these EVs.
Main Methods:
- RT-qPCR and dual luciferase reporter assay to analyze miR-135a-5p, TXNIP, and NLRP3 interactions.
- Oxygen-glucose deprivation/reperfusion (OGD/R) and transient middle cerebral artery occlusion (tMCAO) models.
- Cell counting kit-8 (CCK-8), flow cytometry, TTC staining, and ELISA were used for assessments.
Main Results:
- M2 microglia-derived EVs showed high miR-135a-5p expression.
- miR-135a-5p negatively regulated NLRP3 via TXNIP, promoting neuronal proliferation and inhibiting apoptosis and autophagy.
- EVs delivered miR-135a-5p, suppressing TXNIP, NLRP3 inflammasome activation, and reducing ischemic brain injury.
Conclusions:
- M2 microglia-derived EVs deliver miR-135a-5p to mitigate ischemic brain injury.
- This mechanism involves the inhibition of TXNIP and NLRP3 inflammasome activation.
- M2 microglia-derived EVs are potential therapeutic targets for ischemic brain injury.
