Abstract
Background: Lung ischemia-reperfusion injury (LIRI) is a significant clinical problem occurring after lung transplantation. LIRI is mediated by the overproduction of reactive oxygen species (ROS) and inflammatory activation. Previous studies have confirmed that dexmedetomidine (DEX) exerts a protective effect on LIRI, which potentially causes severe mitochondrial dysfunction. However, the specific mechanisms remain unclear. Our study was to explore whether dexmedetomidine exerts a beneficial effect on LIRI by reducing mitochondrial dysfunction. Methods: Two different models were used in our study. For the in vivo experiment, thirty-two male Sprague-Dawley rats were randomly divided into Sham, ischemia-reperfusion (I/R), DEX+I/R and DEX+yohimbine+I/R (DY+I/R) groups. Similarly, pulmonary vascular endothelial cells (PVECs) from SD rats were divided into Control, oxygen glucose deprivation (OGD), D+OGD and DY+OGD groups.Results: In our experiment, we confirmed severe lung damage after LIRI that was characterized by significantly pulmonary histopathology injury, a decrease in the oxygenation index (PaO2/FiO2) and an increase in the wet-to-dry weight ratio, while DEX treatment mitigated this damage. In addition, the DEX pretreatment significantly attenuated I/R-induced oxidative stress by decreasing the level of ROS in the mitochondria in vitro. Moreover, the DEX treatment enhanced mitochondrial biogenesis and autophagy by increasing the expression of peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α), mitochondrial transcription factor A (Tfam), PTEN-induced putative kinase 1 (PINK1), Parkin and dynamin 1-like protein 1 (Drp1). Conclusions: These data suggest that DEX may alleviate LIRI by reducing mitochondrial dysfunction through the induction of mitochondrial biogenesis and autophagy.
HIGH-DOSE HUMANIN ANALOGUE APPLIED DURING ISCHEMIA PROVIDES CARDIOPROTECTION AGAINST ISCHEMIA-REPERFUSION INJURY THROUGH ATTENUATING MITOCHONDRIAL DYSFUNCTION
