Campus Saint-Jean, University of Alberta, 8406, Marie-Anne-Gaboury Street (91 Street), Edmonton, Alberta, T6C 4G9, Canada.
J Bioenerg Biomembr. 2012 Aug;44(4):503-12. doi: 10.1007/s10863-012-9451-2. Epub 2012 Jun 16.
Mitochondria are producing most of the energy needed for many cellular functions by a process named oxidative phosphorylation (OXPHOS). It is now well recognized that mitochondrial dysfunctions are involved in several pathologies or degenerative processes, including cardiovascular diseases, diabetes, and aging. Animal models are currently used to try to understand the role of mitochondria in human diseases but a major problem is that mitochondria from different species and tissues are variable in terms of regulation. Analysis of mitochondrial function in three species of planarian flatworms (Tricladia, Platyhelminthes) shows that they share a very rare characteristic with human mitochondria: a strong control of oxidative phosphorylation by the phosphorylation system. The ratio of coupled OXPHOS over maximal electron transport capacity after uncoupling (electron transport system; ETS) well below 1.0 indicates that the phosphorylation system is limiting the rate of OXPHOS. The OXPHOS/ETS ratios are 0.62 ± 0.06 in Dugesia tigrina, 0.63 ± 0.05 in D. dorotocephala and 0.62 ± 0.05 in Procotyla fluviatilis, comparable to the value measured in human muscles. To our knowledge, no other animal model displays this peculiarity. This new model offers a venue in which to test the phosphorylation system as a potential therapeutic control point within humans.
线粒体通过氧化磷酸化（OXPHOS）过程产生大多数细胞功能所需的能量。现在人们已经认识到，线粒体功能障碍与几种病理或退行性过程有关，包括心血管疾病、糖尿病和衰老。目前使用动物模型来试图了解线粒体在人类疾病中的作用，但一个主要问题是，不同物种和组织的线粒体在调节方面存在差异。对三种扁形动物（三胚层、扁形动物）的线粒体功能分析表明，它们与人线粒体有一个非常罕见的共同特征：磷酸化系统对氧化磷酸化有很强的控制作用。解偶联后（电子传递系统；ETS）氧化磷酸化与最大电子传递能力之比（OXPHOS/ETS）远低于 1.0 表明磷酸化系统限制了 OXPHOS 的速率。Dugesia tigrina、D. dorotocephala 和 Procotyla fluviatilis 的 OXPHOS/ETS 比值分别为 0.62±0.06、0.63±0.05 和 0.62±0.05，与人类肌肉中测量的值相当。据我们所知，没有其他动物模型具有这种特性。这种新模型为测试磷酸化系统作为人类潜在治疗控制点提供了一个场所。
