Isolation and identification of genes differentially expressed in premature luteinization granulosa cell during controlled ovarian hyperstimulation

Analysis of maturation dynamics and developmental competence of in vitro matured oocytes under time-lapse monitoring

BACKGROUND

To improve the developmental competence of in vitro cultured oocytes, extensive literature focused on maturation rate improvement with different additives in culture medium, while studies investigating the maturation dynamics of oocytes during in vitro maturation (IVM) and the influencing factors on oocyte viability are scarce.

METHODS

The study involved a retrospective observation by time-lapse monitoring of the IVM process of 157 donated GV oocytes from 59 infertile couples receiving ICSI in 2019, in Tongji Hospital, Wuhan, China. The GV oocytes derived from controlled ovarian hyperstimulation (COH) cycles underwent rescue IVM (R-IVM), and the maturation dynamics, including GVBD time (GV-MI), time from GVBD to maturation (MI-MII), maturation time (GV-MII), and MII arrest duration (MII-ICSI), were recorded by time-lapse monitoring. The matured oocytes were inseminated at different MII arrest points and subsequent embryo developments were assessed. The effects of baseline clinical characteristics, oocyte diameters, and maturation dynamics on the developmental competence of the oocytes were also analyzed.

RESULTS

Totally, 157 GV oocytes were collected. GVBD happened in 111 oocytes, with a median GV-MI duration of 3.7 h. The median MI-MII duration was 15.6 h and the median GV-MII duration was 19.5 h. The maturation rate reached 56.7% at 24 h and 66.9% at 48 h, and the clinical factors, including patient age, FSH level, AMH level, ovarian stimulation protocol, and serum estradiol and progesterone levels on hCG trigger day, showed no effects on the 24-h maturation rate. The normal fertilization rate of oocytes resuming meiosis within 8 h and matured within 24 h was significantly higher than that of oocytes resuming meiosis after 8 h and matured after 24 h. Furthermore, among those oocytes matured within 24 h, the high-quality embryo formation rate of oocytes resuming meiosis within 4.5 h and matured within 19 h was significantly higher. All stated time was measured from the start point of IVM. Additionally, for oocytes from patients with serum progesterone levels less than 1 ng/ml on hCG trigger day, the high-quality embryo formation rate was significantly increased.

CONCLUSION

R-IVM technology could increase the available embryos for patients in routine COH cycles, but excessive culture beyond 24 h is not recommended. GV-MI duration of the oocyte, recorded by time-lapse system, and serum progesterone levels of patients on hCG trigger day can significantly affect the developmental potential of the IVM oocytes.

Correlation of progesterone levels on the day of oocyte retrieval with basal hormonal status and the outcome of ART

This study aimed to assess whether basal hormonal levels can predict the levels of progesterone (P4) on the day of oocyte retrieval (OR) and examine the impact of P4 levels on the day of OR on the outcome of assisted reproduction. One hundred sixty-four patients that were enrolled in the assisted reproduction procedure were classified according to their P4 levels on the OR day (< 2 ng/ml vs. ≥ 2 ng/ml). Patients who had P4 levels < 2 ng/ml had significantly higher follicle stimulating hormone (FSH) levels and significantly lower anti-Mullerian hormone (AMH) levels. More than half of patients with P4 levels < 2 ng/ml on the OR day got pregnant and delivered healthy infants. There was a significant correlation between lower FSH values and higher P4 values at OR and between higher AMH values and higher P4 values on the day of OR. Regression analysis showed that high FSH levels are the most important factor that can reliably imply lower P4 levels on OR day. Our study confirmed that lower basal FSH levels can predict the levels of P4 on the OR day. Moreover, lower levels of P4 on the day of OR are associated with a positive outcome in assisted reproduction.

Bone Morphogenetic Protein 15 Knockdown Inhibits Porcine Ovarian Follicular Development and Ovulation

Bone morphogenetic protein 15 (BMP15) is strongly associated with animal reproduction and woman reproductive disease. As a multifunctional oocyte-specific secret factor, BMP15 controls female fertility and follicular development in both species-specific and dosage-sensitive manners. Previous studies found that BMP15 played a critical role in follicular development and ovulation rate in mono-ovulatory mammalian species, especially in sheep and human, but study on knockout mouse model implied that BMP15 possibly has minimal impact on female fertility of poly-ovulatory species. However, this needs to be validated in other poly-ovulatory species. To investigate the regulatory role of BMP15 on porcine female fertility, we generated a BMP15-knockdown pig model through somatic nuclear transfer technology. The BMP15-knockdown gilts showed markedly reduced fertility accompanied by phenotype of dysplastic ovaries containing significantly declined number of follicles, increased number of abnormal follicles, and abnormally enlarged antral follicles resulting in disordered ovulation, which is remarkably different from the unchanged fertility observed in BMP15 knockout mice. Molecular and transcriptome analysis revealed that the knockdown of BMP15 significantly affected both granulosa cells (GCs) and oocytes development, including suppression of cell proliferation, differentiation, and follicle stimulating hormone receptor (Fshr) expression, leading to premature luteinization and reduced estradiol (E2) production in GCs, and simultaneously decreased quality and meiotic maturation of oocyte. Our results provide in vivo evidence of the essential role of BMP15 in porcine ovarian and follicular development, and new insight into the complicated regulatory function of BMP15 in female fertility of poly-ovulatory species.

Different protein expression patterns associated with polycystic ovary syndrome in human follicular fluid during controlled ovarian hyperstimulation

Polycystic ovary syndrome (PCOS) is one of the most common causes of anovulatory infertility, affecting 5-10% of females during their reproductive life. Currently the pathology of PCOS is largely unknown. To identify the differential protein expression in follicular fluids from PCOS and normal subjects during controlled ovarian hyperstimulation, we performed an initial proteomic study including two-dimensional gel electrophoresis (2DE) analysis and mass spectroscopy, and confirmed results by western blot. Thirty-two protein spots were shown to be significantly differentially expressed between PCOS and normal follicular fluids, of which 20 unique proteins were identified to be associated with cellular metabolism and physiological processes; 13 of these proteins were upregulated while seven were downregulated in PCOS follicular fluids. Western blotting analyses confirmed the differential expressions for three randomly selected proteins, i.e. upregulated α1-antitrypsin, apolipoprotein A-I and transferrin in follicular fluid from PCOS patients than normal controls. Furthermore, semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) analyses revealed that mRNA levels of serine palmitoyltransferase 2, serine/threonine-protein kinase male germ cell-associated kinase (MAK) and DNA damage-regulated autophagy modulator protein 2 decreased significantly in granulosa cells of PCOS patients compared with normal samples. These results increase our understanding of PCOS and the identified genes may serve as candidate biomarkers to develop diagnostic and therapeutic tools.

Premature progesterone rise negatively correlated with live birth rate in IVF cycles with GnRH agonist: an analysis of 2,566 cycles

OBJECTIVE

To investigate the occurrence of premature progesterone rise (PPR) in GnRH agonist long or short protocol, address the relationship between circulating P levels and live birth rates, and explore the possible mechanism through which PPR affects clinical outcomes and the possible factors related to the occurrence of PPR.

DESIGN

Retrospective analysis.

SETTING

Reproductive medicine center of a public hospital.

PATIENT(S)

A total of 2,566 patients receiving in vitro fertilization/intracytoplasmic sperm injection treatment with GnRH agonist long or short protocol.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live birth rates.

RESULT(S)

The corresponding incidence of PPR in long or short protocol was 22.86% (393/1,719) or 27.63% (234/847) with the cutoff value of 1.2 ng/mL or 2.0 ng/mL, respectively, being used to define PPR. Live birth rates decreased under the condition of PPR (40.65% vs. 29.77% in long protocol; 30.18% vs. 23.50% in short protocol). Logistic regression analysis showed that serum P level on the day of hCG administration was a strong predictor of live birth rate in both long and short protocols. Live birth rates in frozen embryo transfer cycles had no significant difference between groups with or without PPR (29.31% vs. 25.35% in long protocol; 24.84% vs. 24.22% in short protocol). Multivariate regression analysis showed that exogenous gonadotropin dose, the duration of stimulation, E(2) and LH levels on the day of hCG administration, the number of oocytes retrieved, and basal FSH level were all involved in PPR.

CONCLUSION(S)

In GnRH agonist cycles, PPR negatively correlated with live birth rate in fresh embryo transfer cycles, although no adverse impact on frozen embryo transfer was observed, implying that PPR may have deleterious effects on endometrial receptivity.