Keywords: Ovarian support cells, in vitro maturation, stem cells, live births, multigenerational study
Objective: Our group has developed an ovarian support cells (OSCs) platform derived from human induced pluripotent stem cells for in vitro maturation (IVM). The OSCs demonstrated robust human and murine in vitro oocyte maturation and an improved blastocyst formation rate compared to commercial IVM options (Piechota et al. 2023). However, the potential reproductive toxicity of OSCs on offspring remains unexplored. Therefore, this study aimed to evaluate the OSC’s reproductive toxicity profile in a multigenerational murine study.
Materials and methods: Immature cumulus-oocyte complexes (COCs, n=1,095) and denuded oocytes (n=930) were collected and randomized into Traditional-IVM (commercial MediCult) and OSC-IVM (OSCs and Medicult). The mature oocytes were inseminated and cultured until blastocysts. The embryos were transferred to pseudopregnant CD1 mice to evaluate the long-term effects on reproductive potential. Sex ratio, periodic weight and length, and global health status were monitored. F1 mice were randomly selected and outbred to wild-type mice to generate the F2. The resultant mice were followed up and monitored. Moreover, hormonal levels and organ histological analyses were performed in F1 mice.
Results: The analysis of live births showed that mice delivered with no statistically significant differences between groups. No differences were observed in the sex ratio, pup weight, and length, and no developmental or behavioral abnormalities were reported. When F2 was analyzed, there were no differences in the fecundity or sex ratio between groups, birthing pups without any developmental or behavioral abnormality.
Table 1. Analysis of live births per birthing female. Data presented as mean ± SD
| Denuded oocytes | COCs | P-value | |||
| Traditional-IVM | OSC-IVM | Traditional-IVM | OSC-IVM | ||
| F1 Live birth per transfer (%) | 28.2 ± 19.4 | 29.0 ± 0.07 | 34.3 ± 17.3 | 25.3 ± 13.0 | 0.61 |
| F1 Day 10 weight (g) | 8.8 ± 1.6 | 9.2 ± 1.2 | 9.4 ± 1.2 | 9.7 ± 2.2 | 0.24 |
| F1 Day 10 length (cm) | 5.5 ± 1.2 | 5.0 ± 0.3 | 5.1 ± 0.4 | 5.2 ± 0.7 | 0.13 |
| F1 Sex Ratio(% males) | 45.8 ± 29.7 | 49.0 ± 32.7 | 46.9 ± 37.2 | 54.2 ± 40.0 | 0.97 |
| F1 Day 21 weight (g) | 15.9 ± 1.2 | 16.6 ± 2.2 | 16.1 ± 1.9 | 16.1 ± 3.72 | 0.60 |
| F1 Day 21 length (cm) | 6.8 ± 0.3 | 7.0 ± 0.4 | 7.0 ± 0.4 | 7.0 ± 0.7 | 0.21 |
| F1 Developmental or Behavioral Abnormalities | None noted | None noted | None noted | None noted | N/A |
| F1 Fecundity (F2 pups born per F1) (N) | 8.2 ± 1.5 | 6.8 ± 1.1 | 7.6 ± 2.2 | 8.2 ± 1.6 | 0.20 |
| F2 Sex Ratio(% males) | 53.9 ± 20.0 | 49.3 ± 10.0 | 52.2 ± 20.0 | 51.5 ± 20.0 | 0.96 |
| F2 Developmental or Behavioral Abnormalities | None noted | None noted | None noted | None noted | N/A |
Exploring the overall health of the progeny, we observed similar hormone profiles between conditions and no specific pathological abnormalities associated with any particular experimental group.
Conclusion: OSC-IVM does not display any evidence of reproductive toxicity.
Impact statement: This study suggests that OSC-IVM is a generally safe IVM platform, which is an important finding to support its future clinical trial investigation.
