Tourmente Maximiliano, Sansegundo Ester, Rial Eduardo, Roldan Eduardo R S
Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain.
Centro de Biología Celular y Molecular, Facultad de Ciencias Exactas, Físicas y Naturales (FCEFyN-UNC), Universidad Nacional de Córdoba, Córdoba, Argentina.
Front Cell Dev Biol. 2022 Aug 23;10:950979. doi: 10.3389/fcell.2022.950979. eCollection 2022.
In mammals, sperm acquire fertilization ability after a series of physiological and biochemical changes, collectively known as capacitation, that occur inside the female reproductive tract. In addition to other requirements, sperm bioenergetic metabolism has been identified as a fundamental component in the acquisition of capacitation. Mammalian sperm produce ATP through two main metabolic processes, oxidative phosphorylation (OXPHOS) and aerobic glycolysis that are localized to two different flagellar compartments, the midpiece, and the principal piece, respectively. In mouse sperm, the occurrence of many events associated with capacitation relies on the activity of these two energy-producing pathways, leading to the hypothesis that some of these events may impose changes in sperm energetic demands. In the present study, we used extracellular flux analysis to evaluate changes in glycolytic and respiratory parameters of murine sperm that occur as a consequence of capacitation. Furthermore, we examined whether these variations affect sperm ATP sustainability. Our results show that capacitation promotes a shift in the usage ratio of the two main metabolic pathways, from oxidative to glycolytic. However, this metabolic rewiring does not seem to affect the rate at which the sperm consume ATP. We conclude that the probable function of the metabolic switch is to increase the ATP supply in the distal flagellar regions, thus sustaining the energetic demands that arise from capacitation.
在哺乳动物中，精子在雌性生殖道内发生一系列生理和生化变化（统称为获能）后获得受精能力。除其他条件外，精子生物能量代谢已被确定为获能过程中的一个基本组成部分。哺乳动物精子通过两种主要的代谢过程产生ATP，即氧化磷酸化（OXPHOS）和有氧糖酵解，它们分别定位于鞭毛的两个不同区域，即中段和主段。在小鼠精子中，许多与获能相关的事件的发生依赖于这两种能量产生途径的活性，这导致了一种假设，即这些事件中的一些可能会改变精子的能量需求。在本研究中，我们使用细胞外通量分析来评估获能导致的小鼠精子糖酵解和呼吸参数的变化。此外，我们研究了这些变化是否会影响精子ATP的可持续性。我们的结果表明，获能促进了两种主要代谢途径的使用比例从氧化向糖酵解的转变。然而，这种代谢重编程似乎并不影响精子消耗ATP的速率。我们得出结论，代谢转换的可能功能是增加鞭毛远端区域的ATP供应，从而维持获能产生的能量需求。
