Evaluation of hepatic AMP-activated protein kinase (AMPK), mechanistic target of rapamycin kinase complex 1 (mTORC1) and autophagy-lysosomal pathway in cows with mild or moderate fatty liver

Under energy deficient conditions, AMPK suppresses mTORC1 resulting in TFEB nuclear translocation, which in turn upregulates the transcription of genes related to autophagy lysosomal pathway. Herein, we showed that activity of AMPK, TFEB transcriptional activity and autophagy-lysosomal function were enhanced, but the activity of mTORC1 was inhibited in the liver of dairy cows with mild fatty liver. Conversely, overactivation of mTORC1, suppressed AMPK signaling pathway and TFEB transcriptional activity as well as impaired autophagy-lysosomal function were observed in the liver of dairy cows with moderate fatty liver. These data suggest that the metabolic status may be differ in cows experiencing different degrees of fatty liver.