Glucose stimulates transcription of fatty acid synthase and malic
enzyme in avian hepatocytes.
Hillgartner, F. Bradley, and Tina Charron.
Department of Biochemistry, School of Medicine, West Virginia
University, Morgantown, WV 26506, USA
APStracts 4:0270E, 1997.
Transcription of fatty acid synthase (FAS) and malic enzyme (ME) in
avian liver is low during starvation or feeding a low-carbohydrate,
high-fat diet and high during feeding a high-carbohydrate, low-fat
diet. The role of glucose in the nutritional control of FAS and ME
was investigated by determining the effects of this metabolic fuel on
expression of FAS and ME in primary cultures of chick embryo
hepatocytes. In the presence of triiodothyronine, glucose (25 mM)
stimulated an increase in the activity and mRNA abundance of FAS and
ME. These effects required the phosphorylation of glucose to glucose
-6-phosphate but not further metabolism downstream of the aldolase
step of the glycolytic pathway. Xylitol mimicked the effects of
glucose on FAS and ME expression, suggesting that an intermediate of
the pentose phosphate pathway may be involved in mediating this
response. The effects of glucose on the mRNA abundance of FAS and ME
were accompanied by similar changes in transcription of FAS and ME.
These data support the hypothesis that glucose plays a role in
mediating the effects of nutritional manipulation on transcription of
FAS and ME in liver.
Received 12 September 1997; accepted in final form 25 November
1997.
APS Manuscript Number E432-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 12 December 1997