Low-temperature carbon utilization is regulated by novel gene activity in the heart of a hibernating mammal
| Autor: | Christopher M. Bowen, Matthew T. Andrews, Teresa L. Squire, Martha B. Rollins |
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| Rok vydání: | 1998 |
| Předmět: |
Hibernation
DNA Complementary Multidisciplinary Pyruvate dehydrogenase kinase Myocardium Molecular Sequence Data Temperature Sciuridae Metabolism Biological Sciences Carbohydrate metabolism Biology Isozyme Carbon Carbon utilization Gene Expression Regulation Biochemistry Anaerobic glycolysis Carbohydrate catabolism Animals Cloning Molecular |
| Zdroj: | Proceedings of the National Academy of Sciences. 95:8392-8397 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.95.14.8392 |
| Popis: | Hibernation is a physiological adaptation characterized by dramatic decreases in heart rate, body temperature, and metabolism, resulting in long-term dormancy. Hibernating mammals survive for periods up to 6 mo in the absence of food by minimizing carbohydrate catabolism and using triglyceride stores as their primary source of fuel. The cellular and molecular mechanisms underlying the changes from a state of activity to the hibernating state are poorly understood; however, the selective expression of genes offers one level of control. To address this problem, we used a differential gene expression screen to identify genes that are responsible for the physiological characteristics of hibernation in the heart of the thirteen-lined ground squirrel ( Spermophilus tridecemlineatus ). Here, we report that genes for pancreatic lipase and pyruvate dehydrogenase kinase isozyme 4 are up-regulated in the heart during hibernation. Pancreatic lipase is normally expressed exclusively in the pancreas, but when expressed in the hibernating heart it liberates fatty acids from triglycerides at temperatures as low as 0°C. Pyruvate dehydrogenase kinase isozyme 4 inhibits carbohydrate oxidation and depresses metabolism by preventing the conversion of pyruvate to Ac-CoA. The resulting anaerobic glycolysis and low-temperature lipid catabolism provide evidence that adaptive changes in cardiac physiology are controlled by the differential expression of genes during hibernation. |
| Databáze: | OpenAIRE |
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