Qingwu Shen
College of Animal Science and Technology, Northwest A&F University

AMP-activated protein kinase (AMPK) is an energy sensing serine/threnine kinase that consists of α, β and γ subunits. AMPK is activated by an increase in AMP/ATP ratio. Once activated, AMPK phosphorylates downstream substrate and the biological effects of AMPK are pleiotropic: switching off ATP-consuming processes such as biosynthetic pathways, and switching on catabolic processes to generate ATP, including glycolyssis, as well as increased fatty acid oxidation. In addition to its direct phosphorylation of metabolic enzymes and acute regulation of energy balance within cells, emerging evidence suggests that AMPK is also involved in cell polarity, cell growth, differentiation and apopotosis. The control of energy balance with cells by AMPK and its regulation of cell differentiation and tissue development suggest that AMPK could be a target protein to improve lean meat yield and quality in animal production. Here we reviewed our previous study and some other excellent literature about AMPK involvement in cell differentiation, animal muscle development, fat deposition, and postmortem glycolysis. Data we obtained from both mice and porcine showed that AMPK played a critical role in the control of glycolytic rate early postmortem and AMPK was a potential target for the prevention of PSE meat. Evidence from mutant animals and in vitro cell culture also show that AMPK regulates cell differentiation, animal muscle growth and fat deposition. The positive and negative relationship between animal growth rate and intramuscular fat content to AMPK activity in both cattle and porcine indicate that AMPK might control the balance between myogenesis and adipogenesis. Indeed, a body of literature has showed that AMPK inhibits preadipocyte 3T3-L1 differentiation and the differentiation of adult human and mouse mesenchymal stem cells (MSC) into adipocytes. Although the role of AMPK in myogenesis needs to be further defined, fetal programming studies show that AMPK may play an important regulative role in fetal development. Studies on AMPK regulation of embryonic mesenchymal stem cell differentiation and embryonic myogenesis are currently carrying on in our lab. The temporal difference between embryonic adipogenesis and myogenesis, along with maternal nutrition regulation of AMPK activity in fetuses suggests that AMPK provides a target to optimize postnatal animal growth potential and to increase lean meat yield and quality for meat animal production.