title: Cryptochrome restores dampened circadian rhythms and promotes healthspan in aging Drosophila.
abstract: Circadian clocks generate daily rhythms in molecular, cellular, and physiological functions providing temporal dimension to organismal homeostasis. Recent evidence suggests two-way relationship between circadian clocks and aging. While disruption of the circadian clock leads to premature aging in animals, there is also age-related dampening of output rhythms such as sleep/wake cycles and hormonal fluctuations. Decay in the oscillations of several clock genes was recently reported in aged fruit flies, but mechanisms underlying these age-related changes are not understood. We report that the circadian light-sensitive protein CRYPTOCHROME (CRY) is significantly reduced at both mRNA and protein levels in heads of old Drosophila melanogaster. Restoration of CRY using the binary GAL4/UAS system in old flies significantly enhanced the mRNA oscillatory amplitude of several genes involved in the clock mechanism. Flies with CRY overexpressed in all clock cells maintained strong rest/activity rhythms in constant darkness late in life when rhythms were disrupted in most control flies. We also observed a remarkable extension of healthspan in flies with elevated CRY. Conversely, CRY-deficient mutants showed accelerated functional decline and accumulated greater oxidative damage. Interestingly, overexpression of CRY in central clock neurons alone was not sufficient to restore rest/activity rhythms or extend healthspan. Together, these data suggest novel anti-aging functions of CRY and indicate that peripheral clocks play an active role in delaying behavioral and physiological aging.
authors.affiliation: Department of Zoology, Center for Healthy Aging Research, Oregon State University, 3029 Cordley Hall, Corvallis, OR, 97331, USA.
authors.forename: Kuntol
authors.initials: K
authors.lastname: Rakshit
authors.forename: Jadwiga M
authors.initials: JM
authors.lastname: Giebultowicz
mesh_terms: D000367:Age Factors; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D002940:Circadian Rhythm / Q000235:genetics / Q000502:physiology*; D056931:Cryptochromes / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004330:Drosophila / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D056931:Cryptochromes; D012333:RNA, Messenger
keywords: Cryptochrome; Drosophila; aging; circadian clock; healthspan