Kinnunen Sanni M E, Mänttäri Satu K, Saarela Seppo Y O
Physiol Biochem Zool. 2017 Nov/Dec;90(6):605-612. doi: 10.1086/694295.
The wintering strategy of the Djungarian hamster (Phodopus sungorus) includes a naturally occurring decrease in food intake and body mass. Our aim was to investigate the conceivable role of the metabolic regulators, AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1), in the seasonal adaptation of the Djungarian hamster. In addition, a rate-limiting enzyme in fatty acid synthesis and oxidation, acetyl CoA carboxylase (ACC), was studied. Relative protein expressions and phosphorylated forms (pAMPK and pACC) were determined by Western blot from subcutaneous white adipose tissues (sWAT), abdominal white adipose tissues (aWAT), interscapular brown adipose tissues (iBAT), skeletal muscle, and hypothalamus of winter- and summer-acclimatized hamsters. The winter group had higher AMPK expression in sWAT, aWAT, and iBAT, but the relative amount of phosphorylated protein (pAMPK/AMPK ratio) was lower in these tissues. Furthermore, ACC expression was higher in sWAT and iBAT of the winter animals. pACC (inactive form) levels were higher in all adipose tissues, yet a lower pACC/ACC ratio was detected in iBAT of the winter hamsters. Muscle AMPK expression was lower but pAMPK/AMPK ratio higher in the winter group. SIRT1 expression was higher in muscle and all adipose tissues of the winter hamsters. Hypothalamic protein expressions did not differ between the groups. Higher expressions of AMPK, ACC, and SIRT1 in WAT and iBAT of the winter hamsters suggest a role in the regulation of lipid reserves and increased thermogenic capacity characteristic to the winter-adapted Djungarian hamsters.
中亚仓鼠（Phodopus sungorus）的越冬策略包括食物摄入量和体重的自然下降。我们的目的是研究代谢调节因子腺苷酸活化蛋白激酶（AMPK）和沉默调节蛋白1（SIRT1）在中亚仓鼠季节性适应中的潜在作用。此外，还研究了脂肪酸合成和氧化中的限速酶乙酰辅酶A羧化酶（ACC）。通过蛋白质免疫印迹法测定了冬夏驯化仓鼠的皮下白色脂肪组织（sWAT）、腹部白色脂肪组织（aWAT）、肩胛间棕色脂肪组织（iBAT）、骨骼肌和下丘脑的相对蛋白表达及磷酸化形式（pAMPK和pACC）。冬季组sWAT、aWAT和iBAT中的AMPK表达较高，但这些组织中磷酸化蛋白的相对量（pAMPK/AMPK比值）较低。此外，冬季动物的sWAT和iBAT中的ACC表达较高。所有脂肪组织中的pACC（无活性形式）水平较高，但在冬季仓鼠的iBAT中检测到较低的pACC/ACC比值。冬季组肌肉中的AMPK表达较低，但pAMPK/AMPK比值较高。冬季仓鼠的肌肉和所有脂肪组织中的SIRT1表达较高。两组之间下丘脑蛋白表达无差异。冬季仓鼠WAT和iBAT中AMPK、ACC和SIRT1的较高表达表明它们在调节脂质储备以及增加适应冬季的中亚仓鼠特有的产热能力方面发挥作用。
