Research Paper Volume 6, Issue 10 pp 900—912
The effect of calorie restriction on insulin signaling in skeletal muscle and adipose tissue of Ames dwarf mice
- 1 Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
- 2 Department of Cell Biology and Anatomy, School of Medicine, University of South Carolina Columbia, SC 29209, USA
- 3 Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 100191, China
- 4 Department of Oncological Endocrinology, Medical University of Lodz, 90-752 Lodz, Poland
- 5 Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL 62794, USA
- 6 Department of Head and Neck Surgery, The Greater Poland Cancer Centre, 61-866 Poznan
Received: September 17, 2014 Accepted: October 3, 2014 Published: October 5, 2014
https://doi.org/10.18632/aging.100700How to Cite
Abstract
Long-living Ames dwarf (df/df) mice are homozygous for a mutation of the Prop1df gene. As a result, mice are deficient in growth hormone (GH), prolactin (PRL) and thyrotropin (TSH). In spite of the hormonal deficiencies, df/df mice live significantly longer and healthier lives compared to their wild type siblings. We studied the effects of calorie restriction (CR) on the expression of insulin signaling genes in skeletal muscle and adipose tissue of normal and df/df mice. The analysis of genes expression showed that CR differentially affects the insulin signaling pathway in these insulin target organs. Moreover, results obtained in both normal and Ames dwarf mice indicate more direct effects of CR on insulin signaling genes in adipose tissue than in skeletal muscle. Interestingly, CR reduced the protein levels of adiponectin in the epididymal adipose tissue of normal and Ames dwarf mice, while elevating adiponectin levels in skeletal muscle and plasma of normal mice only.
In conclusion, our findings suggest that both skeletal muscle and adipose tissue are important mediators of insulin effects on longevity. Additionally, the results revealed divergent effects of CR on expression of genes in the insulin signaling pathway of normal and Ames dwarf mice.