Starvation induces an increase in intracellular calcium and potentiates the progesterone-induced mouse sperm acrosome reaction.
Claudia Sánchez-CárdenasAna RomarowskiGerardo OrtaJosé Luis De la Vega-BeltránDavid Martín-HidalgoArturo Hernández-CruzPablo E ViscontiAlberto DarszonPublished in: FASEB journal : official publication of the Federation of American Societies for Experimental Biology (2021)
We have recently reported two different methodologies that improve sperm functionality. The first method involved transient exposure to the Ca2+ ionophore A23187 , and the second required sperm incubation in the absence of energy nutrients (starvation). Both methods were associated with an initial loss of motility followed by a rescue step involving ionophore removal or addition of energy metabolites, respectively. In this work, we show that starvation is accompanied by an increase in intracellular Ca2+ ([Ca2+ ]i ). Additionally, the starved cells acquire a significantly enhanced capacity to undergo a progesterone-induced acrosome reaction. Electrophysiological measurements show that CatSper channel remains active in starvation conditions. However, the increase in [Ca2+ ]i was also observed in sperm from CatSper null mice. Upon starvation, addition of energy nutrients reversed the effects on [Ca2+ ]i and decreased the effect of progesterone on the acrosome reaction to control levels. These data indicate that both methods have common molecular features.