ABSTRACT
BACKGROUND: Cerebral ischemia/reperfusion (I/R) injury after ischemic stroke is usually accompanied with the activation of inflammasome which seriously impairs neurological function. MiR-139 has been reported to be associated with inflammatory regulation in multiple diseases. However, its effect and mechanism on inflammation regulation after cerebral I/R injury are still poorly understood. METHODS: An in vitro model of cerebral I/R injury was constructed with oxygen-glucose deprivation/reoxygenation (OGD/R) treatment. TargetScan bioinformatics analysis and dual luciferase reporter assay were utilized to confirm the targeted relationship between miR-139 and c-Jun. Cell pyroptosis was verified by flow cytometry and Caspase-1 Detection Kit. qRT-PCR assay was performed to detect the expression levels of miR-139, c-Jun, NLRP3 and ASC. Western blotting was applied to measure the protein levels of c-Jun and pyroptosis-related markers NLRP3, ASC, caspase-1, GSDMDNterm. The ELISA assay was applied to measure the release of IL-1ß, IL-18 and LDH. RESULTS: MiR-139 was significantly downregulated whereas c-Jun was obviously upregulated after OGD/R treatment. TargetScan analysis predicted that c-Jun was a potential target of miR-139, which was verified by the dual-luciferase reporter assay. Also, overexpression of miR-139 repressed c-Jun expression. Furthermore, miR-139 inhibited OGD/R-induced cell pyroptosis and the upregulation of NLRP3, caspase-1, ASC, GSDMDNterm, and the release of IL-1ß, IL-18 and LDH, while miR-139 inhibition exerted the opposite effects. However, overexpression of c-Jun aggravated OGD/R-induced nerve injury and partly abolished the neuroprotective effect of miR-139. CONCLUSION: Upregulation of miR-139 exerted neuroprotection against OGD/R-induced nerve injury by negatively regulating c-Jun/NLRP3 inflammasome signaling. This study offered insights for providing potential therapeutic targets for treating cerebral I/R injury.
Subject(s)
Inflammasomes/metabolism , MicroRNAs/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Neurons/metabolism , Proto-Oncogene Proteins c-jun/metabolism , Pyroptosis , Reperfusion Injury/prevention & control , Caspase 1/metabolism , Cell Hypoxia , Cell Line, Tumor , Glucose/deficiency , Humans , Interleukin-18/metabolism , Interleukin-1beta/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , L-Lactate Dehydrogenase/metabolism , MicroRNAs/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Neurons/pathology , Phosphate-Binding Proteins/metabolism , Proto-Oncogene Proteins c-jun/genetics , Reperfusion Injury/genetics , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Signal TransductionABSTRACT
INTRODUCTION: The aim of this study was to explore whether the antibrain edema of hypertonic saline (HS) is associated with alleviating ischemic blood-brain barrier (BBB) permeability by downregulating astrocyte-derived vascular endothelial growth factor (VEGF), which is mediated by microglia-derived NOD-like receptor protein 3 (NLRP3) inflammasome. METHODS: The infarct volume and BBB permeability were detected. The protein expression level of VEGF in astrocytes in a transient focal brain ischemia model of rats was evaluated after 10% HS treatment. Changes in the NLRP3 inflammasome, IL-1ß protein expression, and the interleukin-1 receptor (IL1R1)/pNF-кBp65/VEGF signaling pathway were determined in astrocytes. RESULTS: HS alleviated the BBB permeability, reduced the infarct volume, and downregulated the expression of VEGF in astrocytes. HS downregulates IL-1ß expression by inhibiting the activation of the NLRP3 inflammasome in microglia and then downregulates VEGF expression by inhibiting the phosphorylation of NF-кBp65 mediated by IL-1ß in astrocytes. CONCLUSIONS: HS alleviated the BBB permeability, reduced the infarct volume, and downregulated the expression of VEGF in astrocytes. HS downregulated IL-1ß expression via inhibiting the activation of the NLRP3 inflammasome in microglia and then downregulated VEGF expression through inhibiting the phosphorylation of NF-кBp65 mediated by IL-1ß in astrocytes.
