Testes of most male mammals present the particularity of being externalized from the
body and are consequently slightly cooler than core body temperature
(4–8°C below). Although, hypothermia of the testis is known to increase
germ cells apoptosis, little is known about the underlying molecular mechanisms,
including cold sensors, transduction pathways, and apoptosis triggers. In this study,
using a functional knockout mouse model of the cold and menthol receptors, dubbed
transient receptor potential melastatine 8 (TRPM8) channels, we found that TRPM8
initiated the cold-shock response by differentially modulating cold- and heat-shock
proteins. Besides, apoptosis of germ cells increased in proportion to the cooling
level in control mice but was independent of temperature in knockout mice. We also
observed that the rate of germ cell death correlated positively with the reactive
oxygen species level and negatively with the expression of the detoxifying enzymes.
This result suggests that the TRPM8 sensor is a key determinant of germ cell fate
under hypothermic stimulation.—Borowiec, A.-S., Sion, B., Chalmel, F.,
Rolland, A. D., Lemonnier, L., De Clerck, T., Bokhobza, A., Derouiche, S., Dewailly,
E., Slomianny, C., Mauduit, C., Benahmed, M., Roudbaraki, M., Jégou, B.,
Prevarskaya, N., Bidaux, G. Cold/menthol TRPM8 receptors initiate the cold-shock
response and protect germ cells from cold-shock–induced oxidation.