Nutritional deprivation reduces the transcripts for transcription factors and adipocyte-characteristic proteins in porcine adipocytes

For an organism to survive during nutritional deprivation, it must be able to regulate the genes involved in energy metabolism. White adipose tissue is an energy source during fasting conditions. In adipose tissue, transcription factors regulate several adipocyte-characteristic proteins involved in differentiation and energy metabolism. We investigated the transcript concentrations of two key transcription factors, as well as the transcript concentrations of several adipocyte-characteristic proteins, and genes involved in adipocyte energy metabolism in the adipose tissue of pigs fasted for 72 hours. Nutritional deprivation resulted in decreased transcript concentrations of the transcription factors, peroxisome proliferator-activated receptor gamma, and CCAAT-enhancer-binding protein alpha. The transcript concentrations of several adipocyte-characteristic proteins, fatty acid synthase, glucose transporter 4, lipoprotein lipase, leptin, and adipocyte fatty acid binding protein were also significantly reduced. The insulin receptor transcript concentration did not change. We conclude that these transcript concentration changes are aimed collectively at adjusting energy partitioning to conserve energy during nutritional deprivation, thereby enabling survival.