Overexpression of ALDOC Promotes Porcine Intramuscular and Intermuscular Fat Deposition by Activating the AKT-mTORC1 Signaling Pathway

Abstract

Skeletal muscle fat accumulation, a common complication of obesity, has garnered increasing attention. For livestock animals, intramuscular fat content is a key determinant of meat quality and directly influences consumer preferences for different meat products. However, genes effectively regulating intramuscular and intermuscular fat (IIMF) deposition remain largely unexplored. To address this gap, we employed transcriptome sequencing of muscle from pigs with high and low IIMF contents, uncovering Aldolase C (ALDOC) as a novel key gene controlling IIMF. ALDOC overexpression significantly enhanced the IIMF content both in vivo and in vitro. Mechanistic investigations revealed that ALDOC activates the AKT-mTORC1 axis to promote lipid accumulation in myotubes and intramuscular adipocytes. Notably, the mTORC1 inhibitor rapamycin abrogated ALDOC’s proadipogenic effect. Our findings establish ALDOC as a novel key gene regulating IIMF deposition and identify the ALDOC-AKT-mTORC1 signaling pathway as a promising therapeutic target for treating skeletal muscle fat infiltration and improving pork quality.