Differential temporal therapies with pharmacologically targeted mitochondrial fission/fusion protect the brain against acute myocardial ischemia-reperfusion injury in prediabetic rats: The crosstalk between mitochondrial apoptosis and inflammation

An imbalance of brain mitochondrial dynamics, increases in brain inflammation and apoptosis, and increasing cognitive dysfunction, have been reported as being associated with prediabetes and myocardial ischemia-reperfusion (IR) injury. Since inhibiting mitochondrial fission with Mdivi-1 or promoting fusion with M1 had cardioprotective effects in myocardial IR injury and obesity, the neuroprotective roles of Mdivi-1 and M1 when administered at different time points of myocardial IR injury in obese prediabetes have never been determined. Ninety-six male Wistar rats were fed with either a normal (ND: n = 8) or a high-fat diet to induce prediabetes (HFD: n = 88) for 12 weeks. At week 13, all rats were subjected to left anterior descending coronary artery ligation for 30 min, followed by reperfusion for 120 min. HFD rats were randomly divided into 10 groups and assigned into either a pre-ischemic group treated with vehicle (HFV), pre-ischemic, during-ischemic, or onset of reperfusion groups treated with either Mdivi-1 (MDV), M1, or combined (COM). Heart function was examined invasively, with the heart being terminated to investigate myocardial infarction. Brains were collected to determine mitochondrial functions, inflammation, apoptosis, and pathological markers. Mdivi-1, M1, and COM treatment at different periods exerted cardioprotection against myocardial IR injury in HFD-fed rats by reducing infarct size and left ventricular dysfunction. All interventions also improved all brain pathologies against myocardial IR injury in prediabetic rats. These findings suggest that differential temporal modulation of mitochondrial dynamics may be appropriate regimens for preventing heart and brain complications after myocardial IR injury in obese prediabetes.