The effect of melatonin on in vitro maturation fertilization and early embryo development of mouse oocytes and expression of HMGB1 gene in blastocysts

Antioxidants are commonly used for maturation, fertilization and early development of embryos. Melatonin as an antioxidant have been recently proven to be useful for the assisted reproductive technology. In the present study, we evaluated the roles of melatonin in the in vitro maturation, fertilization, development and also the gene expression of high mobility group box-1 (HMGB1) in the blastocysts. The immature oocytes of BDF1 mice were transferred to the media containing different doses of melatonin (10-6, 10-9, 10-12 M). The blastocysts that developed under in vitro fertilization from each group were stained to determine the cell number of embryos and analyzed to determine the expression level of HMGB1 by real-time PCR. The most effective doses of melatonin for maturation of oocytes were 10-6 and 10-12M (P<0.05). Fertilization rate, early development and the cell number of blastocysts were significantly higher in the group that treated with 10-12 M of melatonin comparing to the other groups. The HMGB1 expression decreased in groups that treated with 10-6M and 10-9M of melatonin and increased in the group that treated with 10-12 M of melatonin, but did not show a significant difference (p˃0.05). From the results, it may be concluded that the melatonin could be effective when the embryos undergo maturation, fertilization and early developmental processes. The HMGB1 expression, as a marker of early development in mice embryos, increased in the groups that treated with low doses of melatonin

A new three-dimensional glass scaffold increases the in vitro maturation efficiency of buffalo (Bubalus bubalis) oocyte via remodelling the extracellular matrix and cell connection of cumulus cells.

At present, many three-dimensional (3D) culture systems have been reported, improving the oocyte quality of in vitro maturation (IVM), yet the mechanism still needs to be further explored. Here we examined the effects of a new self-made 3D glass scaffold on buffalo oocyte maturation; meanwhile, the underlying mechanism on buffalo oocyte maturation was also detected. Compared to the two-dimensional (2D) glass dish culture, results revealed that the 3D culture can improve the first polar body rate of oocytes, subsequent cleavage and blastocysts rate of parthenogenetic activation embryos (p < .05). The extracellular matrix-related proteins COL1A1, COL2A1, COL3A1, FN and cell connection-related proteins N-cadherin, E-cadherin, GJA1 were found higher in cumulus cells of 3D culture. Moreover, in cumulus cells, proteins of the PI3K/AKT pathway reported being regulated by FN and E-cadherin including PI3K P85 and p-AKT were also higher in 3D culture. Furthermore, proapoptosis proteins P53, BAX, caspase-3 were lower in both cumulus cells and oocytes in 3D culture, while proteins PCNA and BCL2 showed the opposite result. Results also showed that the apoptosis was inhibited, and the proliferation was enhanced in cumulus cells of 3D culture. Finally, the cumulus expansion-related genes HAS2, CD44, HMMR, PTX3, PTGS2 were found higher in cumulus cells of 3D culture. Taken together, the 3D culture could promote oocyte maturation by regulating proteins correlated with the ECM, cell connection and PI3K/AKT pathway, inhibiting the apoptosis of cumulus cells and oocytes, enhancing the proliferation of cumulus cells and the cumulus expansion.

A three-dimensional alginate system for in vitro culture of cumulus-denuded feline oocytes.

In the case of high valuable individuals with very precious genetic material, widening the genetic pool including gametes with poor morphological characteristics, as cumulus-denuded oocytes (CDOs), could be an option. To improve the in vitro culture of low-competence feline CDOs, an enriched three-dimensional (3D) system in association with competent cumulus-oocyte complexes (COCs) was developed. For this purpose, domestic cat CDOs were cultured with or without companion COCs in the 3D barium alginate microcapsules. The overall viability and the meiotic progression of feline CDOs cocultured with COCs or cultured separately in 3D or in 2D (traditional microdrops) system were compared. The 3D system was able to support viability and meiotic resumption of the feline oocytes, as well as the 2D microdrops. In 3D microcapsules, the presence of COCs resulted in a higher viability of CDOs (91.1%, p < .05), than that obtained without COCs or in 2D microdrops (71.2% and 67.3%, respectively), but the percentages of meiotic resumption were similar of those of CDOs cultured separately (55.4% vs. 40.4%, p > .05). It is notable that the presence of CDOs seemed to enhance the meiotic progression of the associated COCs. In conclusion, the 3D barium alginate microcapsules are a suitable system for feline oocytes in vitro culture, but more specific enriched conditions should be developed to improve the CDOs full competence in vitro.

¿Es ético congelar ovocitos para retrasar la maternidad por motivos laborales? / Is it ethical to freeze oocytes to delay childbearing for employment?

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The effect of ovarian puncture on the endocrine profile of PCOS patients who undergo IVM.

BACKGROUND: To examine whether ovarian puncture for immature oocyte retrieval and in-vitro maturation (IVM) has an effect on the endocrine profile of patients with polycystic ovary syndrome (PCOS). METHODS: Twenty-two consecutive patients with PCOS undergoing IVM treatment were included. Serum anti-Müllerian hormone (AMH), sex hormone-binding globulin (SHBG), total testosterone (TT) and luteinized hormone (LH) levels were analyzed at the start of the cycle, on the day of immature oocyte retrieval (OR) and at fixed intervals thereafter, for up to three months after OR. RESULTS: Five days after OR circulating AMH, TT, calculated free testosterone (FTc), and LH levels were significantly reduced and circulating SHBG was significantly increased. Two weeks after OR, TT, FTc and LH remained reduced, whereas circulating AMH and SHBG levels recovered to pre-puncture values. Three months after OR, all circulating hormone levels had recovered to baseline values. CONCLUSION: Ovarian puncture for the retrieval of immature oocytes and IVM in patients with PCOS has a significant impact on the ovarian endocrine profile, but this impact is brief and transient.

A comparison of the Cook single lumen immature ovum IVM needle to the Steiner-Tan pseudo double lumen flushing needle for oocyte retrieval for IVM.

PURPOSE: This study compared the impact of using the Steiner-Tan pseudo double lumen needle for antral follicle oocyte retrieval to using a conventional non-flushing needle. The Steiner-Tan needle has a much smaller dead space than the needles commonly used for IVM oocyte retrievals. METHODS: This was a retrospective cohort study. The patient population was determined by the time period in which a patient underwent IVM in a single physician's IVF practice. The following data was abstracted from clinical and embryology records: oocytes retrieved, oocytes matured, early maturing oocytes, oocytes fertilized, embryo quality measures, retrieval time, needle punctures, clot formation, and clinical pregnancy rate. RESULTS: The Steiner-Tan needle did not increase the number of oocytes retrieved. It also did not increase the time required for retrieval. However, flushing of antral follicles significantly decreased clot formation in fluid aspirates. Use of the Steiner-Tan needle also significantly decreased the number of vaginal needle punctures during each case. There was a trend toward improved embryo quality, but statistical power was inadequate to show a difference. CONCLUSIONS: The primary benefit of the Steiner-Tan needle was on the embryological aspects of IVM. Decreased blood and blood clots in the aspirates made an IVM retrieval more like conventional IVF for the embryologist. The patient also experienced less tissue trauma without increasing anesthesia or surgical time. There was no improvement in the number of oocytes retrieved, but based on the results, we hypothesized that oocytes were more commonly retrieved from slightly large follicles than when using a routine needle.

In vitro maturation system for individual culture of bovine oocytes using micro-volume multi-well plate.

As a preliminary study for the development of individual in vitro maturation (IVM) culture of bovine oocytes, a multi-well (MW) plate was used. Maturation, fertilization and development to blastocysts were examined and compared with those of IVM oocytes cultured in 50-microl droplets in groups and in 10-microl droplets individually. The maturation rates were similar in all experimental groups. Normal fertilization rates in MW and 50-microl droplets were similar, but lower in 10-microl droplets (p < 0.01). The blastocyst rate in 10-microl droplets tended to be lower than those in MW (p = 0.15) and 50-microl droplets (p = 0.19). These results indicate that an IVM system using MW supports the acquisition of developmental competence by bovine oocytes the same as conventional group IVM culture.

In vitro maturation (IVM) of porcine oocytes.

Oocyte maturation is a critical component of in vitro embryo production. If not carried out in a precise manner under optimal conditions, subsequent fertilization and embryo development will be compromised. Here, we describe collection and in vitro maturation procedures in swine that maintain oocyte competence, resulting in successful embryo development following fertilization. These procedures can be used both for basic research purposes and large-scale production of mature oocytes for use in subsequent assisted reproductive technologies.