CircRNA_0000927 promotes inflammatory response to neuronal injury via miR-126a-5p/PGC-1α axis in acute ischemic stroke

Abstract

Abstract Purpose We investigated the role of CircRNA_0000927 on the occurrence and development of acute ischemic stroke (AIS) and neuronal injury by targeting the miR-126a-5p/PGC-1α axis to find a novel clinical drug target and prediction and treatment of AIS. Methods The mouse AIS animal model was used in vivo experiments and hypoxia/reoxygenation cell model in vitro was established. Firstly, infarction volume and pathological changes of mouse hippocampal neurons were detected using HE staining. Secondly, rat primary neuron apoptosis was detected by flow cytometry assay. The numbers of neuron, microglia and astrocytes were detected using immunofluorescence (IF). Furthermore, binding detection was performed by bioinformatics database and double luciferase reporter assay. CircRNA_0000927 localization was performed using fluorescence in situ hybridization (FISH). CircRNA_0000927, miR-126a-5p and PGC-1α mRNA expression was performed using RT-qPCR. NLRP3, ASC, Caspase-1 and PGC-1α protein expression was performed using Western blotting. IL-1β was detected by ELISA assay. Results Mouse four-vessel occlusion could easily establish the animal model, and AIS animal model had an obvious time-dependence. HE staining showed that, compared with the sham group, infarction volume and pathological changes of mouse hippocampal neurons were deteriorated in the model group. Furthermore, compared with the sham group, neurons were significantly reduced, while microglia and astrocytes were significantly activated. Moreover, the bioinformatics prediction and detection of double luciferase reporter confirmed the binding site of circRNA_0000927 to miR-126a-5p and miR-126a-5p to PGC-1α. CircRNA_0000927 and PGC-1α expression was significantly down-regulated and miR-126a-5p expression was significantly up-regulated in AIS animal model in vivo. At the same time, the expression of inflammasome NLRP3, ASC, Caspase-1 and pro-inflammatory factor IL-1β was significantly up-regulated in vivo and in vitro. The over-expression of circRNA_0000927 and miR-126a-5p inhibitor could inhibit the neuron apoptosis and the expression of inflammasome NLRP3, ASC, Caspase-1 and pro-inflammatory factor IL-1β and up-regulate the expression of PGC-1α in vitro. Finally, over-expression of circRNA_0000927 and miR-126a-5p inhibitor transfected cell model was significant in relieving the AIS and neuronal injury. Conclusion CircRNA_0000927 promotes inflammatory response to neuronal injury via miR-126a-5p/PGC-1α axis in AIS.