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Insulin Represses Fasting-Induced Expression of Hepatic Fat-Specific Protein 27
Kohei Matsuo1, Kimihiko Matsusue1, Daisuke Aibara1
1Faculty of Pharmaceutical Science, Fukuoka University.
Biological & Pharmaceutical Bulletin
|June 2, 2017
Summary
Fasting induces fat-specific protein 27 (Fsp27) in mouse livers, independent of PPARγ. Insulin and glucose administration repress this Fsp27 induction, suggesting insulin
Area of Science:
- Molecular biology
- Metabolic regulation
- Lipid metabolism
Background:
- Fat-specific protein 27 (Fsp27) is a member of the CIDE family, highly expressed in adipose tissue and fatty liver.
- Fsp27 expression in the liver of obese (ob/ob) mice is regulated by peroxisome proliferator-activated receptor γ (PPARγ).
Purpose of the Study:
- To investigate the regulation of Fsp27 expression in mouse liver and adipose tissue under fasting and refeeding conditions.
- To determine the role of PPARγ and insulin in the fasting-induced regulation of Fsp27 in the liver.
Main Methods:
- Analysis of Fsp27 gene expression in liver and adipose tissue of mice under different nutritional states (fasting, refeeding).
- Investigation of Fsp27 regulation in streptozotocin-induced diabetes model (insulin depletion).
- Assessment of the effects of glucose and insulin administration on Fsp27 expression in fasting mice.
Main Results:
- Fasting markedly induced Fsp27 expression in normal mouse livers, while refeeding repressed it.
- Fasting decreased Fsp27 expression in adipose tissue, with refeeding increasing it.
- Fasting-induced Fsp27 liver expression was independent of PPARγ and was also observed in insulin-depleted livers.
- Direct injection of glucose or insulin into fasting mice repressed Fsp27 expression.
Conclusions:
- Fasting induces Fsp27 expression in the liver through a PPARγ-independent mechanism.
- Insulin plays a significant role in repressing Fsp27 expression in the fasting liver.
- Fsp27 regulation differs between liver and adipose tissue in response to nutritional changes.
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