Biology of Reproduction and Stem Cell Group, CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
Reproduction. 2013 Oct 1;146(5):R163-74. doi: 10.1530/REP-13-0178. Print 2013.
Although mitochondria are best known for being the eukaryotic cell powerhouses, these organelles participate in various cellular functions besides ATP production, such as calcium homoeostasis, generation of reactive oxygen species (ROS), the intrinsic apoptotic pathway and steroid hormone biosynthesis. The aim of this review was to discuss the putative roles of mitochondria in mammalian sperm function and how they may relate to sperm quality and fertilisation ability, particularly in humans. Although paternal mitochondria are degraded inside the zygote, sperm mitochondrial functionality seems to be critical for fertilisation. Indeed, changes in mitochondrial integrity/functionality, namely defects in mitochondrial ultrastructure or in the mitochondrial genome, transcriptome or proteome, as well as low mitochondrial membrane potential or altered oxygen consumption, have been correlated with loss of sperm function (particularly with decreased motility). Results from genetically engineered mouse models also confirmed this trend. On the other hand, increasing evidence suggests that mitochondria derived ATP is not crucial for sperm motility and that glycolysis may be the main ATP supplier for this particular aspect of sperm function. However, there are contradictory data in the literature regarding sperm bioenergetics. The relevance of sperm mitochondria may thus be associated with their role in other physiological features, particularly with the production of ROS, which in controlled levels are needed for proper sperm function. Sperm mitochondria may also serve as intracellular Ca²⁺ stores, although their role in signalling is still unclear.
虽然线粒体是真核细胞的能量工厂而广为人知，但这些细胞器除了产生 ATP 之外，还参与各种细胞功能，例如钙稳态、活性氧（ROS）的产生、内在凋亡途径和甾体激素生物合成。本综述的目的是讨论线粒体在哺乳动物精子功能中的可能作用，以及它们如何与精子质量和受精能力相关，特别是在人类中。尽管父系线粒体在受精卵内被降解，但精子线粒体的功能似乎对受精至关重要。事实上，线粒体完整性/功能的变化，即线粒体超微结构或线粒体基因组、转录组或蛋白质组的缺陷，以及线粒体膜电位降低或耗氧量改变，与精子功能丧失（特别是运动能力下降）相关。来自基因工程小鼠模型的结果也证实了这一趋势。另一方面，越来越多的证据表明，线粒体衍生的 ATP 对于精子运动不是必需的，糖酵解可能是精子功能这一方面的主要 ATP 供应源。然而，文献中关于精子生物能量学的数据存在矛盾。因此，精子线粒体的相关性可能与其在其他生理特征中的作用有关，特别是与 ROS 的产生有关，ROS 的适量产生对于精子的正常功能是必需的。精子线粒体也可以作为细胞内 Ca²⁺储存库，尽管它们在信号转导中的作用仍不清楚。
