Exosomal microRNA-150-5p from bone marrow mesenchymal stromal cells mitigates cerebral ischemia/reperfusion injury via targeting toll-like receptor 5

MicroRNA (miR)-150-5p has been investigated in many studies, while the role of exosomal miR-150-5p from bone marrow mesenchymal stromal cells (BMSCs) on cerebral ischemia/reperfusion (I/R) injury is not fully explored. This research aims to probe the effects of exosomal miR-150-5p from BMSCs on cerebral I/R injury via regulating B-cell translocation gene 2 (TLR5). BMSCs were cultured and transfected with miR-150-5p mimic, then exosomes from BMSCs were extracted. The middle cerebral artery occlusion (MCAO) rat model was established, and miR-150-5p and TLR5 levels in rat brain tissues were detected. Then, gain and loss-function assays were conducted to determine the impact of exosomes, miR-150-5p and TLR5 on neurological function, pathological changes, neuron apoptosis and inflammatory factors of MCAO rats. The binding relation between miR-150-5p and TLR5 was validated. It was found that miR-150-5p expression was decreased while TLR5 level was augmented in MCAO rats. The exosomes from BMSCs could improve neurological function, pathological changes, decelerate neuron apoptosis and reduce inflammatory factors in MCAO rats. Enriched miR-150-5p or decreased TLR5 could enhance the protective effects of exosomes from BMSCs on cerebral I/R injury. The elevated TLR5 reversed the impacts of elevated exosomal miR-150-5p. TLR5 was targeted by miR-150-5p. This research manifested that exosomal miR-150-5p from BMSCs exerts protective effects on cerebral I/R injury via repressing TLR5. This study provided novel therapeutic targets for the treatment of cerebral I/R injury.