Controllable oxidative stress and tissue specificity in major tissues during the torpor-arousal cycle in hibernating Daurian ground squirrels
Controllable oxidative stress and tissue specificity in major tissues during the torpor-arousal cycle in hibernating Daurian ground squirrels
复制标题
冬眠达斡尔地松鼠冬眠唤醒周期中主要组织的可控氧化应激和组织特异性
DOI：
10.1098/rsob.180068
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发表时间：
2018
期刊：
影响因子：
5.8
通讯作者：
Gao Yunfang
中科院分区：
文献类型：
--
作者：
Wei Yanhong;Zhang Jie;Xu Shenhui;Peng Xin;Yan Xia;Li Xiaoyu;Wang Huiping;Chang Hui;Gao Yunfang
哺乳动物冬眠者在麻木-觉醒周期中反复经历缺氧缺血和再灌流。我们研究了达乌尔黄鼠(Spermophilus Dauricus)冬眠不同时期心、肝、脑、肾组织和血浆中氧化应激水平、抗氧化能力及其可能的机制。我们的数据显示，与夏季活动状态(SA)相比，昏迷晚期(LT)心脏和大脑中过氧化氢的水平显著增加。睡眠间歇期(IBA)和昏迷早期(ET)的丙二醛(MDA)含量显著低于SA或冬眠前(Pre)，而LT脑组织中的MDA含量显著高于其他状态。在整个昏迷-觉醒周期中，心脏中的超氧化物歧化酶2蛋白水平显著增加。在冬眠周期中，过氧化氢酶在肝脏中的表达水平保持在较高水平。在IBA和ET状态下，所有组织中超氧化物歧化酶1和谷胱甘肽过氧化物酶1(GPX1)的表达显著增加。此外，在IBA和ET期间，所有组织中的各种抗氧化酶活性均高于LT期间，而血浆中GPx活性在冬眠季节显著下降。P-Nrf2在IBA期间各组织中的表达均下降，但在LT期间显著增加，尤其是在肝组织中。有趣的是，大多数变化的指标在冬眠后(POST)恢复到SA或Pre水平。这些结果表明，LT期间增加的活性氧物种可能激活了Nrf2/Keap1抗氧化途径，并可能有助于在IBA和ET状态下发现丙二醛水平的降低，从而保护生物体在昏迷-觉醒的冬眠周期中免受氧化损伤。这是关于冬眠者主要氧化组织中氧化应激和组织特异性的显着可控性的首次报道。
Mammalian hibernators experience repeated hypoxic ischaemia and reperfusion during the torpor–arousal cycle. We investigated levels of oxidative stress, antioxidant capacity, and the underlying mechanism in heart, liver, brain and kidney tissue as well as plasma during different periods of hibernation in Daurian ground squirrels (Spermophilus dauricus). Our data showed that the levels of hydrogen peroxide significantly increased in the heart and brain during late torpor (LT) compared with levels during the summer active (SA) state. The content of malondialdehyde (MDA) was significantly lower during interbout arousal (IBA) and early torpor (ET) than that during SA or pre-hibernation (PRE), and MDA levels in the LT brain were significantly higher than the levels in other states. Superoxide dismutase 2 protein levels increased markedly in the heart throughout the entire torpor–arousal cycle. Catalase expression remained at an elevated level in the liver during the hibernation cycle. Superoxide dismutase 1 and glutathione peroxidase 1 (GPx1) expression increased considerably in all tissues during the IBA and ET states. In addition, the activities of the various antioxidant enzymes were higher in all tissues during IBA and ET than during LT; however, GPx activity in plasma decreased significantly during the hibernation season. The expression of p-Nrf2 decreased in all tissue types during IBA, but significantly increased during LT, especially in liver tissue. Interestingly, most changed indicators recovered to SA or PRE levels in post-hibernation (POST). These results suggest that increased reactive oxygen species during LT may activate the Nrf2/Keap1 antioxidant pathway and may contribute to the decreased MDA levels found during the IBA and ET states, thereby protecting organisms from oxidative damage over the torpor-arousal cycle of hibernation. This is the first report on the remarkable controllability of oxidative stress and tissue specificity in major oxidative tissues of a hibernator.