Ambient Temperature Influences Aging in an Annual Fish (Nothobranchius Rachovii) (I)

Temperature reduction (TR) can extend the lifespan of organisms, but the mechanism is unknown. Our lab used an annual fish (Nothobranchius rachovii) to study this mechanism. The results of recent studies were shown as follows. We bred Nothobranchius rachovii at 20°C (low temperature), 25°C (moderate temperature) and 30°C (high temperature) for 18 day.Fish at 20°C extended the lifespan and fish at 30°C shortened the lifespan, compared to fish at 25°C. Age-related molecules assays showed that the expression of age-related molecules decreased with TR. In other words, TR can maintain rejuvenation to extend lifespan. Mitochondrial function assays showed that mitochondrial efficiency increase with TR. Anti-aging molecules assays showed that anti-aging molecules increase with TR. These phenomena have nothing to do with heat and cold shock proteins. Based on the above results, we plan to study the mechanism of lifespan extension induced by TR with confocal microscopic techniques, electron microscopic techniques, and biochemical techniques in the future 3 years. Research items are planned in the present proposal. (1) Whether the lifespan extension of Nothobranchius rachovii only depends on TR and has nothing to do with calorie restriction (CR). Simultaneously, whether the lifespan extension of Nothobranchius rachovii can be further extended by the combination of TR and CR. (2) study the expression of cellular degradation molecules of Nothobranchius rachovii at 20°C, 25°C, and 30°C (mTOR、pmTOR、LC3、Hsc70、Lamp1、Lamp2、proteosome density and activity、lysosome density and activity) because we infer that TR activates the cellular degradation system to extend lifespan. (3) study the expression of energy metabolism molecules of Nothobranchius rachovii at 20°C, 25°C, and 30°C (AMPK、pAMPK、HOAD、 CS、CPTII、FFA、PPAR-α、PDK4、PDH、eIF4E and fatty acid synthase) because we infer that TR improve the energy metabolism to extend lifespan. This study will answer the mechanism of lifespan extension induced by TR.

Project ID:PA9907-3103
External Project ID:NSC99-2311-B182-002-MY3