Ambient temperature influences aging in an annual fish (Nothobranchius rachovii)

Abstract

SummaryExtending lifespan by lowering ambient temperature in the habitat has been shown in a variety of organisms. Its mechanism, however, remains elusive. In this study, we examined the survivorship and the aging process of the annual fish (Nothobranchius rachovii) reared under high (30°C), moderate (25°C) and low (20°C) ambient temperatures. The results showed that low ambient temperatures prolong survivorship, whereas high ambient temperatures shorten survivorship. At low ambient temperature, expression of senescence-associated b-galactosidase, lipofuscin, reactive oxygen species, lipid peroxidation, protein oxidation, mitochondrial density and ADP ⁄ ATP ratio were reduced compared with those reared at high and moderate temperatures, whereas catalase activity, Mn-superoxide dismutase activities, mitochondrial membrane potential and the levels of ATP, ADP, Sirt1 and Forkhead box O expression were elevated. The expression levels of Hsp70 and CIRP showed no significant difference under any of the ambient temperatures tested. We concluded that cellular metabolism, energy utilization and gene expression are altered at lower ambient temperature, which is associated with the extension of lifespan of the annual fish.

Effects of dietary protein levels on the disease resistance, immune function and physical barrier function in the gill of grass carp ( Ctenopharyngodon idella ) after challenged with Flavobacterium columnare

“…Therefore, we further explored the effects of dietary protein levels on the integrity of epithelial cells and their intercellular TJs in the gills of grass carp. In fish, an excess of ROS causes oxidative damage to lipids and proteins, which is reflected in the contents of MDA and PC, respectively [75,76]. In the present study, compared with low or high levels of protein, at optimal levels of dietary protein, the contents of ROS, MDA and PC decreased in the gills of grass carp, indicating that an optimal level of dietary protein protected fish from oxidative damage to the gill.…”

Changes in mitochondrial energy utilization in young and old worker honeybees (Apis mellifera)

“…This phenomenon is the result of mitochondrial dysfunction during the aging process (Ames et al 1995;Trifunovic and Larsson 2008;Artal-Sanz and Tavernarakis 2008;López-Lluch et al 2008;Chanséaume and Morio 2009). In addition, the extended life span that accompanies TR, noted above, is associated with high ΔΨm (Hsu and Chiu 2009). Thus, the high ΔΨm in the trophocytes and fat cells of young workers may have cellular functions similar to the high ΔΨm observed with TR.…”

“…Suspensions of fixed cells were incubated with 40 nM MTG for 20 min at room temperature in the dark, washed twice, and observed by confocal microscopy (Leica TCS SP2; Leica, Wetzlar, Germany). Confocal microscopic images were analyzed with QWin image processing and analysis software (version 2.5; Leica, Wetzlar, Germany) (Hsu and Chiu 2009). This experiment was biologically replicated five times and used a total of five young and five old workers.…”

“…Trophocytes and fat cells were stained with 10 μM JC1 for 30 min, washed three times with PBS, fixed in 4 % paraformaldehyde, washed three times with PBS, excited at a wavelength of 488 nm, and visualized using confocal microscopy (Leica TCS SP2; Leica, Wetzlar, Germany). ΔΨm was determined by the ratiometric analysis of red fluorescence emitted by JC1 aggregates (590 nm) and green fluorescence emitted by the monomer (525 nm) using QWin image processing and analysis software (version 2.5; Leica, Wetzlar, Germany) (López-Lluch et al 2006;Hsu and Chiu 2009). This experiment was biologically replicated five times and used a total of five young and five old workers.…”

“…Furthermore, temperature reduction (TR) can extend the life span of organisms, a life span extension that is associated with low mitochondrial density (Hsu and Chiu 2009). The fact that mitochondrial density increased with advancing age in the trophocytes and fat cells of workers is reconfirmed by the expression levels of ND1, ATP synthase, and VDAC1.…”