Fertilization and early embryology: Granulosa cells improve human embryo development in vitro

Abstract

A total of 17 couples with repetitive implantation failure after transfer of fresh or frozen-thawed embryos had half of their zygotes cultured in standard conditions and frozen at day 2 after insemination, and the other half cocultured with autologous granulosa cells and transferred at the morula or blastocyst stage at day 5 or 6 after oocyte retrieval. At the end of the culture period, supernatants of cocultures were recovered for steroid assays. Monolayers were stained for granulosa cell growth and morphological assessment. We observed that granulosa cells improve embryo development in vitro since 32 out of 60 (53%) reached the morula stage and 18 (30%) the blastocyst stage, leading to a total of 83% embryos available for transfer (compared with 3% without coculture). The ongoing pregnancy rate of these patients who were selected because they had at least three previous implantation failures, is only 5.9%, however, which is similar to the control group without coculture (6.3%). To conclude, granulosa cells improve embryo development but not the pregnancy rate after transfer of cocultured embryos in patients with multiple previous implantation failures.

Follicular Fluid and Cumulus Cells Synergistically Improve Mouse Early Embryo Development In Vitro

“…Like in many other studies [2][3][4][5][6][17][18][19] the results of the present investigation show that the co-culture system generally had beneficial effects on embryo development through increasing the proportion of embryos passing the critical 2-cell stage and developing to blastocysts. Several mechanisms have been suggested to explain the positive effects of co-culture systems on embryonic development and quality.…”

Human pregnancies after transfer of fresh (four-to eight-cell) versus frozen-thawed blastocysts resulting from intracytoplasmic sperm injection

“…However, there have been strong controversies related to using ICSI as a human therapeutic technique. The quality of the embryos obtained after ICSI could not be correlated with the previous observations gathered from regular IVF, where there was a strong negative relationship between embryo quality and abnormal sperm parameters (2)(3)(4)(5).…”

“…Different cell culture systems such as uterine fibroblasts (10), ampullary epithelial cells (8), endometrial cells (1 I), granulosa cells (5), and green monkey kidney epithelial cells (7,12,13) have been used to produce human blastocysts. In our studies we used Vero cells (green monkey kidney epithelial cells) because they produce constant rates of growth factors from the beginning to the end of the coculture period (Menezo, unpublished results).…”

Growth and Differentiation of Small Ovarian Follicles in Mammals: Problems and Future Perspectives.

“…By means of heterologous gap junctions, granulosa cells support germ cell growth [20,24], prevent premature meiotic resumption by transferring cell cyclearresting factors, as purines and cAMP [36,37], modulate oocyte transcriptional activity [38], protein synthesis and phosphorylation [39][40][41], thus promo ting oocyte capacity to undergo successful fertilization and preimplantation development. In humans, granulosa lutein cells i n f l u e n c e o o c y t e q u a l i t y a n d e m b r y o developmental potential [42][43][44]. At the same time, the oocyte regulates a broad range of granulosa cell functions through the release of paracrine signals.…”