Differential detection of secretome(s) from pregnancy-associated blastocysts by sperm heat-induced hyperactivation assay

Abstract

OBJECTIVE: Signaling proteins from healthy versus defective blastocysts might be distinguished using a stressed sperm motility assay. The objective was to assess motility parameters in sperm incubated in spent conditioned media obtained after blastocyst transfer.DESIGN: Retrospective study.MATERIALS AND METHODS: Cryopreserved sperm were washed by 2-gradient (90:45) centrifugation procedure and resuspended in modified HTF medium. An aliquot (100 uL at 50 mill./mL) of sperm was added to either: (1) spent media from pregnant (2) nonpregnant cycles or (3) control HTF. Sperm were also added to spent media from corresponding control droplets from (4) pregnant and (5) nonpregnant cycles. The spent media (G-2 ver 5, Vitrolife) were left-over from blastocysts transferred back after IVF with pregnant (N=5) or nonpregnant (N=5) outcomes and previously stored frozen (-24°C). Computer-aided sperm analyses parameters were determined at hrs. O and 4 of incubation at 40°C in air. Data from 5 experiments were analyzed by Student's t-test.Table 1Percent of control ± SEM.NONPREGNANTPREGNANTP∗Motility94.5 ± 7.097.9 ± 4.7Progression82.2 ± 3.0106.7 ± 3.7<0.05Curvilinear Vel.98.3 ± 0.9100.4 ± 5.4Hyperactivation67.9 ± 0.6254.5 ± 0.6<0.05 Open table in a new tab Sperm progressive motility was also higher in the pregnant group. However, there were no differences in the remaining sperm parameters.CONCLUSIONS: The results suggested that secretomes released by blastocysts associated with pregnancies improved parameters such as hyperactivation and progression. Standard analyses of total motility would not be predictive of outcome. Heat stressing of the sperm was required to show differences. Furthermore, the data suggested that the lower parameters in the nonpregnant group were due to an inhibitory effect. The stressed sperm motility assay might be useful for identifying healthy embryos. OBJECTIVE: Signaling proteins from healthy versus defective blastocysts might be distinguished using a stressed sperm motility assay. The objective was to assess motility parameters in sperm incubated in spent conditioned media obtained after blastocyst transfer. DESIGN: Retrospective study. MATERIALS AND METHODS: Cryopreserved sperm were washed by 2-gradient (90:45) centrifugation procedure and resuspended in modified HTF medium. An aliquot (100 uL at 50 mill./mL) of sperm was added to either: (1) spent media from pregnant (2) nonpregnant cycles or (3) control HTF. Sperm were also added to spent media from corresponding control droplets from (4) pregnant and (5) nonpregnant cycles. The spent media (G-2 ver 5, Vitrolife) were left-over from blastocysts transferred back after IVF with pregnant (N=5) or nonpregnant (N=5) outcomes and previously stored frozen (-24°C). Computer-aided sperm analyses parameters were determined at hrs. O and 4 of incubation at 40°C in air. Data from 5 experiments were analyzed by Student's t-test. Sperm progressive motility was also higher in the pregnant group. However, there were no differences in the remaining sperm parameters. CONCLUSIONS: The results suggested that secretomes released by blastocysts associated with pregnancies improved parameters such as hyperactivation and progression. Standard analyses of total motility would not be predictive of outcome. Heat stressing of the sperm was required to show differences. Furthermore, the data suggested that the lower parameters in the nonpregnant group were due to an inhibitory effect. The stressed sperm motility assay might be useful for identifying healthy embryos.