Propofol elicits autophagy via endoplasmic reticulum stress and calcium exchange in C2C12 myoblast cell line

In this study, we investigated the relationship between propofol and autophagy and examined whether this relationship depends on ER stress, production of ROS (reactive oxygen species), and disruption of calcium (Ca(2+)) homeostasis. To this end, we measured C2C12 cell apoptosis in vitro, along with Ca(2+) levels; ROS production; and expression of proteins and genes associated with autophagy, Ca(2+) homeostasis, and ER stress, including LC3 (microtubule-associate protein 1 light chain 3), p62, AMPK (adenosine 5’-monophosphate (AMP)-activated protein kinase), phosphorylated AMPK, mTOR (the mammalian target of rapamycin), phosphorylated mTOR, CHOP (C/BEP homologous protein), and Grp78/Bip (78 kDa glucose-regulated protein). We found that propofol treatment induced autophagy, ER stress, and Ca(2+) release. The ratio of phosphorylated AMPK to AMPK increased, whereas the ratio of phosphorylated mTOR to mTOR decreased. Collectively, the data suggested that propofol induced autophagy in vitro through ER stress, resulting in elevated ROS and Ca(2+). Additionally, co-administration of an ER stress inhibitor blunted the effect of propofol.