Hypothalamic thyroid hormone catabolism acts as a gatekeeper for the seasonal control of body weight and reproduction

Barrett, Perry; Ebling, Francis J.P.; Schuhler, Sandrine; Wilson, Dana; Ross, Alexander W.; Warner, Amy; Jethwa, Preeti; Boelen, Anita; Visser, Theo J.; Ozanne, Daniel M.; Archer, Zoe A.; Mercer, Julian G.; Morgan, Peter J.

Abstract

Seasonal adaptations in physiology exhibited by many animals involve an interface between biological timing and specific neuroendocrine systems, but the molecular basis of this interface is unknown. In this study of Siberian hamsters, we show that the availability of thyroid hormone within the hypothalamus is a key determinant of seasonal transitions. The expression of the gene encoding type III deiodinase (Dio3) and Dio3 activity in vivo (catabolism of T4 and T3) is dynamically and temporally regulated by photoperiod, consistent with the loss of hypothalamic T3 concentrations under short photoperiods. Chronic replacement of T3 in the hypothalamus of male hamsters exposed to short photoperiods, thus bypassing synthetic or catabolic deiodinase enzymes located in cells of the ependyma of the third ventricle, prevented the onset of short-day physiology: hamsters maintained a long-day body weight phenotype and failed to undergo testicular and epididymal regression. However, pelage moult to a winter coat was not affected. Type II deiodinase gene expression was not regulated by photoperiod in these hamsters. Collectively, these data point to a pivotal role for hypothalamic DIO3 and T3 catabolism in seasonal cycles of body weight and reproduction in mammals. Copyright © 2007 by The Endocrine Society.

Citation

Barrett, P., Ebling, F. J., Schuhler, S., Wilson, D., Ross, A. W., Warner, A., Jethwa, P., Boelen, A., Visser, T. J., Ozanne, D. M., Archer, Z. A., Mercer, J. G., & Morgan, P. J. (2007). Hypothalamic thyroid hormone catabolism acts as a gatekeeper for the seasonal control of body weight and reproduction. Endocrinology, 148(8), 3608-3617. https://doi.org/10.1210/en.2007-0316

• Journal Article Type: Article
• Acceptance Date: Apr 20, 2007
• Publication Date: Aug 1, 2007
• Deposit Date: Jun 25, 2021
• Journal: Endocrinology
• Print ISSN: 0013-7227
• Electronic ISSN: 1945-7170
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 148
• Issue: 8
• Pages: 3608-3617
• DOI: https://doi.org/10.1210/en.2007-0316
• Public URL: https://nottingham-repository.worktribe.com/output/3158457
• Publisher URL: https://academic.oup.com/endo/article/148/8/3608/2501812