Capacitation promotes a shift in energy metabolism in murine sperm

TOURMENTE, MAXIMILIANO; SANSEGUNDO, ESTER; RIAL, EDUARDO; ROLDAN, EDUARDO R. S.

Frontiers in Cell and Developmental Biology

Frontiers Media

Lugar: Laussane; Año: 2022 vol. 10

In mammals, sperm acquire fertilization ability after a series of physiological andbiochemical changes, collectively known as capacitation, that occur inside thefemale reproductive tract. In addition to other requirements, spermbioenergetic metabolism has been identified as a fundamental componentin the acquisition of capacitation. Mammalian sperm produce ATP through twomain metabolic processes, oxidative phosphorylation (OXPHOS) and aerobicglycolysis that are localized to two different flagellar compartments, themidpiece, and the principal piece, respectively. In mouse sperm, theoccurrence of many events associated with capacitation relies on theactivity of these two energy-producing pathways, leading to the hypothesisthat some of these events may impose changes in sperm energetic demands. Inthe present study, we used extracellular flux analysis to evaluate changes inglycolytic and respiratory parameters of murine sperm that occur as aconsequence of capacitation. Furthermore, we examined whether thesevariations affect sperm ATP sustainability. Our results show that capacitationpromotes a shift in the usage ratio of the two main metabolic pathways, fromoxidative to glycolytic. However, this metabolic rewiring does not seem toaffect the rate at which the sperm consume ATP. Weconclude that the probablefunction of the metabolic switch is to increase the ATP supply in the distalflagellar regions, thus sustaining the energetic demands that arise fromcapacitation.