A decrease in glucose supply promotes cell death in bovine corpus luteum.

Glucose (GLU) is an essential energy source for mammalian cells, and its depletion induces various cellular responses, including apoptosis. The present study examined whether a decrease in GLU levels induces apoptotic cell death, which typically occurs during regression of the bovine corpus luteum (CL). To investigate the possible mechanisms of luteal cell death induced by low GLU levels, we examined the effect of GLU-free medium on the expression of apoptosis-regulating factors (FAS, BAX, BCL2, CASP8, and CASP3). GLU depletion induced cell death in bovine mid-luteal cells. Luteal cells cultured in GLU-free medium showed reduced viability, which was rescued by GLU supplementation in a dose-dependent manner. Culturing without GLU increased the expression of FAS and CASP3 mRNAs. Inhibiting glucose transporter 1 (GLUT1) with cytochalasin B or STF-31 in the presence of GLU also induced cell death. Based on these findings, a decrease in GLU supply, which is induced by a decrease in blood flow to the CL during luteolysis, may promote apoptosis by stimulating the expression of FAS and CASP3 in the bovine CL.