Figure 2. The proposed mechanism of the alcohol-induced autophagy in the liver.

Cellular receptors trigger the autophagy following the classic 4 stages, as described in the text. Alcohol exposure triggers autophagy. Alcohol and/or its metabolites inhibit the mTOR pathway thus releasing its inhibition of autophagy. The effect of alcohol on protein in the final stages of autophagy, namely autophagosome-lysosome fusion, and on catabolism of cargo proteins is still unclear. The existence of alcohol-induced mitophagy is unknown. The effect of alcohol on receptor-initiated autophagy and their downstream signaling pathways remain largely unexplored. Known effects are depicted with lines and arrows; unknowns are depicted with “?” sign; the up- and down-regulation is depicted by the orientation of the arrows.