Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an, 710069, China.
Shaanxi Sci-Tech University, School of Biological Science and Engineering, Hanzhong, 723001, China.
Sci Rep. 2017 Sep 5;7(1):10509. doi: 10.1038/s41598-017-10829-6.
We investigated cytosolic calcium (Ca) and sarcoplasmic reticulum Ca regulation in skeletal muscle fibers of hibernating Daurian ground squirrels (Spermophilus dauricus), non-hibernating hindlimb-unloaded (HLU) squirrels, and HLU rats to clarify the molecular mechanisms involved in preventing muscle atrophy in hibernators. The Na, K-ATPase and Ca-ATPase activities in the soleus muscle (SOL) of squirrels were maintained in hibernation, decreased during interbout arousal (IB-A), and increased to autumn/pre-hibernation (AUT/Pre-H) levels in torpor after interbout arousal (Post-IBA), whereas activities in the extensor digitorum longus muscle (EDL) were stable during hibernation, but increased during post-hibernation (Post-H). Activities increased in the SOL of HLU rats, but were stable in HLU squirrels. Sarco/endoplasmic reticulum Ca-ATPase (SERCA) activity in the SOL decreased in IB-A squirrels, but returned to AUT/Pre-H levels in the Post-IBA group; no significant changes were found in the EDL. SERCA activity increased in the EDL of HLU squirrels and SOL of HLU rats. Compared with AUT/Pre-H, SERCA type 2 protein expression increased in the SOL and EDL of IB-A and Post-IBA squirrels, but increased in the SOL only in HLU animals. We also describe the protein kinase A changes in this paper. Thus, hibernating ground squirrels displayed remarkable Na, K-ATPase, Ca-ATPase, and SERCA plasticity.
我们研究了冬眠达乌尔黄鼠（Spermophilus dauricus）、非冬眠后肢去负荷（hindlimb-unloaded，HLU）松鼠和 HLU 大鼠骨骼肌纤维的细胞质钙（Ca）和肌浆网 Ca 调节，以阐明参与防止冬眠动物肌肉萎缩的分子机制。在冬眠期间，松鼠比目鱼肌（soleus muscle，SOL）中的 Na，K-ATP 酶和 Ca-ATP 酶活性得以维持，在觉醒间隔（interbout arousal，IB-A）期间减少，并在觉醒后间隔（post-interbout arousal，Post-IBA）的蛰伏期间增加到秋季/冬眠前（autumn/pre-hibernation，AUT/Pre-H）水平，而伸趾长肌（extensor digitorum longus muscle，EDL）中的活性在冬眠期间保持稳定，但在冬眠后增加。HLU 大鼠的 SOL 活性增加，而 HLU 松鼠则保持稳定。SOL 中的肌浆/内质网 Ca-ATP 酶（sarco/endoplasmic reticulum Ca-ATPase，SERCA）活性在 IB-A 松鼠中减少，但在 Post-IBA 组中恢复到 AUT/Pre-H 水平；在 EDL 中未发现明显变化。HLU 松鼠的 EDL 和 HLU 大鼠的 SOL 中的 SERCA 活性增加。与 AUT/Pre-H 相比，IB-A 和 Post-IBA 松鼠的 SOL 和 EDL 中 SERCA 类型 2 蛋白表达增加，但仅在 HLU 动物的 SOL 中增加。我们还在本文中描述了蛋白激酶 A 的变化。因此，冬眠达乌尔黄鼠表现出显著的 Na，K-ATP 酶、Ca-ATP 酶和 SERCA 可塑性。
