Patterns of mitochondrial membrane remodeling parallel functional adaptations to thermal stress
Patterns of mitochondrial membrane remodeling parallel functional adaptations to thermal stress
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DOI：
10.1242/jeb.174458
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发表时间：
2018-04-01
影响因子：
2.8
通讯作者：
Schulte, Patricia M.
中科院分区：
文献类型：
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作者：
Chung, Dillon J.;Sparagna, Genevieve C.;Schulte, Patricia M.
温度对线粒体性能的影响被认为部分是由于其对线粒体膜的影响。大量研究表明，热驯化和适应可以改变线粒体内膜（IMM）的数量，但对生物体调节线粒体膜组成的能力知之甚少。利用适应不同环境温度的大西洋鳉鱼（Fundulus heteroclitus）的北部和南部亚种，我们评估了热适应是否会改变肝脏线粒体呼吸能力或IMM的组成和数量。我们测量了磷脂头组和头组特异性脂肪酸（FA）重塑的变化，并使用呼吸测量法评估线粒体呼吸能力。适应5摄氏度和33摄氏度改变了两个亚种的线粒体呼吸能力。在不同的驯化温度下，北方F. heteroclitus表现出更大的线粒体呼吸能力，这与之前观察到的亚种在整个生物体有氧代谢方面的差异一致。线粒体磷脂在热驯化后发生改变，这些变化的方向在亚种之间基本一致。这些影响主要是由特定磷脂类的重塑驱动的，并与代谢表型的变化有关。亚种之间的膜组成也存在差异，这在很大程度上是由磷脂类的差异所驱动的。亚种之间和驯化过程中呼吸能力的变化在很大程度上但不是完全由IMM量的变化来解释的。综上所述，这些结果支持肝脏线粒体功能的变化在驯化和适应过程中对热应激的变热反应中的作用，并暗示脂质重塑是促成这些变化的机制。
The effect of temperature on mitochondrial performance is thought to be partly due to its effect on mitochondrial membranes. Numerous studies have shown that thermal acclimation and adaptation can alter the amount of inner-mitochondrial membrane (IMM), but little is known about the capacity of organisms to modulate mitochondrial membrane composition. Using northern and southern subspecies of Atlantic killifish (Fundulus heteroclitus) that are locally adapted to different environmental temperatures, we assessed whether thermal acclimation altered liver mitochondrial respiratory capacity or the composition and amount of IMM. We measured changes in phospholipid headgroups and headgroup-specific fatty acid (FA) remodeling, and used respirometry to assess mitochondrial respiratory capacity. Acclimation to 5 degrees C and 33 degrees C altered mitochondrial respiratory capacity in both subspecies. Northern F. heteroclitus exhibited greater mitochondrial respiratory capacity across acclimation temperatures, consistent with previously observed subspecies differences in whole-organism aerobic metabolism. Mitochondrial phospholipids were altered following thermal acclimation, and the direction of these changes was largely consistent between subspecies. These effects were primarily driven by remodeling of specific phospholipid classes and were associated with shifts in metabolic phenotypes. There were also differences in membrane composition between subspecies that were driven largely by differences in phospholipid classes. Changes in respiratory capacity between subspecies and with acclimation were largely but not completely accounted for by alterations in the amount of IMM. Taken together, these results support a role for changes in liver mitochondrial function in the ectothermic response to thermal stress during both acclimation and adaptation, and implicate lipid remodeling as a mechanism contributing to these changes.