Turn down genes for WAT? Activation of anti-apoptosis pathways protects white adipose tissue in metabolically depressed thirteen-lined ground squirrels

摘要: During hibernation, the metabolic rate of thirteen-lined ground squirrels (Ictidomys tridecemlineatus) can drop to <5 % normal resting at 37 °C, core body temperature decrease as low 1–5 °C, and heart fall from 350–400 5–10 bpm. Energy saved by hibernating allows survive winter when food is scarce, living off lipid reserves in white adipose tissue (WAT) crucial. While hibernating, some energy must be used cope with conditions that would normally damaging for mammals (e.g., temperatures, ischemia) could induce cell death via apoptosis. Cell survival largely dependent on relative amounts activities pro- anti-apoptotic Bcl-2 family proteins. The present study analyzed how proteins respond protect WAT cells during hibernation. Relative levels several were quantified immunoblotting over six time points torpor-arousal cycle. These included members Bcl-2, Bcl-xL, Mcl-l, well caspase inhibitors x-IAP c-IAP. Changes protein and/or phosphorylation also observed various regulators apoptosis (p-JAKs, p-STATs, SOCS, PIAS). Mcl-1 increased whereas c-IAP protein/phosphorylation decreased signifying important roles certain Importantly, selected STAT increased, suggesting a mechanism activation. results suggest an increase cytoprotective mechanisms supports efforts