title: Late-onset temperature reduction can retard the aging process in aged fish via a combined action of an anti-oxidant system and the insulin/insulin-like growth factor 1 signaling pathway.
abstract: Two different mechanisms are considered to be related to aging. Cumulative molecular damage caused by reactive oxygen species (ROS), the by-products of oxidative phosphorylation, is one of these mechanisms (ROS concept). Deregulated nutrient sensing by the insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) pathway is the second mechanism (IIS concept). Temperature reduction (TR) is known to modulate aging and prolong life span in a variety of organisms, but the mechanisms remain poorly defined. Here we first demonstrate that late-onset TR from 26 °C to 22 °C extends mean life span and maximum life span by approximately 5.2 and 3 weeks, respectively, in the annual fish Nothobranchius guentheri. We then show that TR is able to decrease the accumulation of the histological aging markers senescence-associated β-galactosidase (SA-β-Gal) in the epithelium and lipofuscin (LF) in the liver and to reduce protein oxidation and lipid peroxidation levels in the muscle. We also show that TR can enhance the activities of catalase, glutathione peroxidase, and superoxide dismutase, and stimulate the synthesis of SirT1 and FOXO3A/FOXO1A, both of which are the downstream regulators of the IIS pathway. Taken together, our findings suggest that late-onset TR, a simple non-intrusion intervention, can retard the aging process in aged fish, resulting in their life span extension, via a synergistic action of an anti-oxidant system and the IIS pathway. This also suggests that combined assessment of the ROS and IIS concepts will contribute to providing a more comprehensive view of the anti-aging process.
authors.affiliation: 1 Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China , Qingdao, China .
authors.forename: Xia
authors.initials: X
authors.lastname: Wang
authors.forename: Qingyun
authors.initials: Q
authors.lastname: Chang
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Su
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000375:Aging; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D005399:Fishes; D005979:Glutathione Peroxidase / Q000378:metabolism; D007328:Insulin / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D015227:Lipid Peroxidation; D008055:Lipids / Q000737:chemistry; D008136:Longevity; D008297:Male; D010100:Oxygen / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000378:metabolism; D013696:Temperature; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D007328:Insulin; D008055:Lipids; D017382:Reactive Oxygen Species; D007334:Insulin-Like Growth Factor I; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001616:beta-Galactosidase; D010100:Oxygen