Electroacupuncture Preconditioning Attenuates Myocardial Ischemia-Reperfusion Injury by Inhibiting Microglial Engulfment of Dendritic Spines in the Fastigial Nucleus
Description
A major side effect of reperfusion therapy following myocardial infarction is myocardial ischemia-reperfusion injury (MIRI). Electroacupuncture preconditioning (EA-pre) has a long history in the treatment of cardiovascular diseases. Here, we demonstrate how EA-pre attenuates MIRI by affecting the phagocytosis of neuronal dendritic spines of microglia of the fastigial nucleus (FNmicroglia). From optical-fiber-based Ca2+ signal recordings in GABAergic neurons of the FN (FNGABA), we observed that EA-pre for 7 days increased activity in FNGABA and then improved myocardial injury by inhibiting abnormal activities of glutaminergic neurons of the FN (FNGlu) during MIRI. Interestingly, we observed changes in the quantity and shape of FN microglia in mice treated with EA-pre, and a decrease in the phagocytosis of FNGABA neuronal dendritic spines by microglia. Furthermore, the effects of improving MIRI were reversed when EA-pre mice were chemically activated by intra-FN lipopolysaccharide injection, followed by a reduction in FNGABA activity. Overall, our results provide new insight indicating that EA-pre negatively regulates microglial engulfment capacity, thus promoting the improvement of cardiac sympathetic nervous injury and disorders during MIRI.