Empiric therapy for patients with unexplained recurrent pregnancy loss (URPL) is not precise. Some patients will ask for assisted reproductive technology due to secondary infertility or advanced maternal age. The clinical outcomes of URPL patients who have undergone in vitro fertilization-embryo transfer (IVF-ET) require elucidation. The IVF outcome and influencing factors of URPL patients need further study.

In vitro maturation (IVM) of oocyte is an effective procedure for avoiding ovarian hyperstimulation syndrome in patients with polycystic ovaries (PCOS) during in vitro fertilization (IVF). To investigate the influences of IVM on epigenetic reprogramming and to search for the possible reasons for the lower rates of fertilization and cleavage in IVM oocytes, we examined the expression of two enzymes controlling histone acetylation, histone acetyltransferase GCN5 (GCN5) and histone deacetylase 1 (HDAC1), as well as their common target, acetyl-histone H3 (Ac-H3), in mouse metaphase II (MII) oocytes and preimplantation embryos. Results showed that IVM downregulated the protein expression of GCN5 in MII oocytes and two-cell embryos and changed the distribution of GCN5 in two-cell embryos. Expression of HDAC1 mRNA in MII oocytes and two-cell embryos decreased in the IVM group. However, none of these changes persisted after two-cell embryos. Levels of Ac-H3 in both oocytes and embryos remained unchanged after IVM. Our studies indicated that IVM could affect the protein and gene expression related to histone acetylation in oocytes and early cleavage embryos. By function of selection, parts of the changes could be recovered in late embryo development.

Epigallocatechin-3-gallate (EGCG) is a major ingredient of catechin polyphenols and exerts protective effects because of its strong antioxidant properties. As far as we know, there is still a lack of systematic research on the effects of EGCG on the in vitro maturation (IVM) and in vitro fertilization (IVF) of porcine oocytes. The present study aimed to determine the effects of EGCG on the IVM and IVF of porcine oocytes.

In mammals, β-defensins have been reported to play pivotal roles in sperm protection and fertilization. However, the function and mechanism of porcine β-defensin 129 (pBD129) in the sperm remain unclear. Here, we demonstrate that pBD129 is a glycosylated protein and broadly exists in accessory sex glands and coats the sperm surface. We inhibited the pBD129 protein on the sperm surface with an anti-pBD129 antibody and found that sperm motility was not significantly affected; however, sperm acrosome integrity and tyrosine phosphorylation levels increased significantly with time (p < 0.05) during capacitation. These changes were accompanied by an increase in sperm Ca2+ influx, resulting in a significantly reduced in vitro fertilization cleavage rate (p < 0.05). Further investigation revealed that treatment with recombinant pBD129 markedly restored the sperm motility in semen contaminated with Escherichia coli. The results suggest that pBD129 is not only associated with poor sperm motility after genital tract infection but can also protect the spermatozoa from premature capacitation, which may be beneficial for semen preservation.

The optimal time at which to perform a frozen-thawed embryo transfer (FET) following a failed in-vitro fertilization-embryo transfer (IVF-ET) attempt remains elusive to most reproductive experts. Physicians often delay the introduction of FET due to concerns related to potential residual effects of ovarian hyperstimulation which may interfere with the regular menstrual cycle. Moreover, given that most of the published studies on the topic are retrospective and have inconsistent findings, it is crucial to develop evidence-based randomized control guides for clinical practice. Therefore, this well-designed randomized controlled trial (RCT) was conducted to determine whether it is necessary to delay FET for at least one menstrual cycle after the failure of fresh embryo transfer.

Acupuncture and moxibustion has become a commonly used adjuvant treatment method to improve the success rate of in vitro fertilization-embryo transfer (IVF-ET). However, There is still insufficient evidence that acupuncture treatment can improve the local microenvironment of endometrium, the endometrial receptivity, and the pregnancy outcome of patients, which is worthy of further study.

Animal fertility is one of the most important characteristics for the livestock breeding industry. Conventional semen analysis provides basic information on sperm quality, but the predictive value of such analysis with regard to fertility remains questionable. Therefore, it is important to determine and predict male fertility more accurately in the clinic. To identify seminal plasma proteins involved in fertility, isobaric tags for relative and absolute quantitation (iTRAQ) and liquid chromatography with tandem mass spectrometry (quantitative proteomic analysis) were used to identify differentially abundant proteins (DAPs) in seminal plasma between high- and low-reproductive-efficiency Landrace boars. A total of 141 DAPs were identified, of which 125 upregulated and 16 downregulated proteins were subjected to bioinformatics analysis. These DAPs were found to be mainly involved in proteolysis, ATP binding, and energy metabolism. We investigated the relevance of three DAPs-ceruloplasmin, carboxypeptidase E (CPE), and serpin family A member 12 (SERPINA12)-in an in vitro fertility assay. This assay revealed that the inhibition of these proteins with antibodies can reduce or increase the fertilization rate. These results indicate possible biomarkers for the selection of high-fertility boars and provide a theoretical basis for the use of protein biomarkers in the livestock breeding industry. SIGNIFICANCE: Our study identified differentially abundant proteins in the seminal plasma of high-reproductive-efficiency and low-reproductive-efficiency Landrace boars. These proteins may be used as biomarkers to screen out high-fertility boars. The study can provide not only a new method for improving the effects of artificial insemination and reproductive efficiency of boars but also an important reference for boar breeding. Meanwhile, because pigs and humans have similar physiological parameters and organ sizes, our findings can also serve as a reference for human reproduction research.

The proteins in the seminal plasma and on the sperm surface play important roles in sperm function and numerous reproductive processes. The cysteine-rich secretory proteins (CRISPs) are enriched biasedly in the male reproductive tract of mammals, and CRISP2 is the sole member of CRISPs produced during spermatogenesis; whereas the role of CRISP2 in fertilization and its association with fertility of boars are still unclear. This study aimed to investigate the relationship between the sperm CRISP2 and boar fertility, and explore its impact sperm fertilizing ability. The levels of CRISP2 protein in sperm were quantified by ELISA; correlation analysis was performed to evaluate the association between CRISP2 protein levels and boar reproductive parameters. Meanwhile, the expression of CRISP2 in boar reproductive organs and sperm, and the effects of CRISP2 on in vitro fertilization (IVF) were examined. The results showed that boars with high sperm levels of CRISP2 had high fertility. The protein levels of CRISP2 in sperm were positively correlated with the litter size (r = 0.412, p = 0.026), the number of live-born piglets (r = 0.421, p = 0.023) and the qualified piglets per litter (r = 0.381, p = 0.042). CRISP2 is specifically expressed in the testis and sperm of adult boars, and its location on sperm changed mainly from the post-acrosomal region to the apical segment of acrosome during capacitation. The cleavage rate was significantly decreased by adding the anti-CRISP2 antibody to the IVF medium, which indicates CRISP2 plays a critical role in fertilization. In conclusion, CRISP2 protein is specifically expressed in the adult testis and sperm and is associated with sperm fertilizing ability and boar fertility. Further mechanistic studies are warranted, in order to fully decipher the role of CRISP2 in the boar reproduction.

Vascular endothelial growth factor receptor-2 (VEGFR-2) regulates the mitogen-activated protein kinase (MAPK) signaling pathway and plays an important role in angiogenesis. Bu Shen Zhu Yun decoction (BSZYD) can improve endometrial receptivity and embryo implantation rates in patients undergoing in vitro fertilization. However, whether BSZYD improves endometrial receptivity via angiogenesis remains unclear. Here, we investigated the effects of BSZYD on the proliferation, migration, and angiogenesis of human endometrial microvascular endothelial cells (HEMECs) and found that BSZYD upregulated the expression of cyclin D1, matrix metalloproteinase 9 (MMP9), and proliferating cell nuclear antigen (PCNA) in HEMECs. Cell Counting Kit 8 assay, scratch-wound assay, and Tube Formation Assay results showed that BSZYD promoted the proliferation, migration, and angiogenesis of HEMECs. Western blot analysis results revealed the activation of the MAPK signaling pathway by BSZYD through the upregulation of VEGF and VEGFR-2 expression. Together, these findings highlight the novel mechanism underlying BSZYD-mediated improvement in endometrial receptivity through the MAPK signaling pathway.