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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #105959
Title: NUTRITIONAL DEPRIVATION REDUCES THE TRANSCRIPTS FOR TRANSCRIPTION FACTORS AND ADIPOCYTE-CHARACTERISTIC PROTEINS IN PORCINE ADIPOCYTES

Author
item MCNEEL, RONALD - BAYLOR COLL OF MEDICINE
item Mersmann, Harry

Submitted to: Journal of Nutritional Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/2/1999
Publication Date: 5/1/2000
Citation: N/A

Interpretive Summary: We are interested in studying how fat cells develop and are controlled because of their role in obesity, a major American health problem, especially among children. Adipose tissue, or fat, is a source of energy available to animals when they are in a starvation state. We wanted to determine what happens to certain transcript concentrations during starvation. Transcripts are the templates for making proteins involved in metabolism of the cell. We used fat tissue from pigs that were fasted for 72 hours, and examined the transcript concentrations of two key transcription factors (PPAR-gamma and C/EBP-alpha), which are major controllers in the process of fat cell development and growth. They regulate other transcripts that produce proteins characteristic of mature fat cells. We found that these transcription factors were reduced, or downregulated. We also found that fat cell-characteristic transcripts also odownregulated, apparently in response to control by these transcription factors. They apparently downregulate to let the organism use the energy stored in the fat cells to survive. This is useful information for researchers who are attempting to further the understanding and treatment of human obesity.

Technical Abstract: In order 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.