Infertility and Immunocontraception based on zona pellucida

Human oocyte zona pellucida abnormalities: evaluation of clinical impact for different zona pellucida abnormalities and role of using assisted hatching

BACKGROUND

Zona pellucida (ZP) plays an important role in oocyte development and fertilisation, as well as in early embryo development. However, there is currently no exploration of systematic categorising and clinical treatment measures for patients with abnormal ZP, especially the fast and easy method that can be used clinically.

METHODS

In this study, 185 patients with abnormal ZP (ZPA) and 222 patients with normal ZP (ZPN) were enrolled and analysed.

RESULTS

Patients with ZPA exhibited altered hormone levels and lower laboratory outcomes in in vitro fertilisation (IVF), such as reduced MII rate, cleavage rate, high-quality embryo rate, and blastocyst formation rate compared to ZPN group. ZPA patients were sub-categorised into ZPA-A/B/C/D group according to the status of oocyte polar body and the width of perivitelline space (PVS). There are also differences in the degree of sperm binding to ZP derived from different ZPA patients and the elasticity of the oocyte membrane. ZPA subgroup analysis revealed further disparities in various IVF parameters and pregnancy outcomes. In addition, by performing different treatments on oocytes derived from ZPA patients, we found that ZP assisted hatching before the first oocyte cleavage on D1 of embryonic development in the ZPA-A/B groups and before blastocyst expansion on D4 of embryonic development in the ZPA-C/D groups were beneficial to improve embryonic development.

CONCLUSION

The degree of the impact on clinical outcomes is correlated with the types of ZPA, and laser-assisted hatching of the ZP helps to improve embryonic development in patients with ZPA.

Zona pellucida removal by acid Tyrode's solution affects pre- and post-implantation development and gene expression in mouse embryos

The zona pellucida (ZP) plays a crucial role in the process of fertilization to early embryonic development, including cellular arrangement and communication between blastomeres. However, little is known regarding the role of the ZP in pre- and post-implantation embryonic development associated with gene expression. We investigated the effect of zona pellucida removal (ZPR) on pre- and post-implantation development of mouse embryos. After ZPR of 2-cell stage embryos was performed by acid Tyrode's solution, which is commonly used for ZP treatment, compaction occurred earlier in ZP-free (ZF) than ZP-intact (ZI) embryos. In addition, the expression of differentiation-related genes in the inner cell mass (ICM) and trophectoderm (TE) was significantly altered in ZF blastocyst compared with ZI embryos. After embryo transfer, the rate of implantation and live fetuses was lower in ZF embryos than in control embryos, whereas the fetal weight at E17.5 was not different. However, placental weight significantly increased in ZF embryos. RNA-seq analysis of the placenta showed that a total of 473 differentially expressed genes (DEGs) significantly influenced the biological process. The present study suggests that ZPR by acid Tyrode's solution at the 2-cell stage not only disturbs the expression pattern of ICM/TE-related genes but affects the post-implantation development of mouse embryos. Overall, this study provides deeper insight into the role of the ZP during early embryonic development and the viability of post-implantation development.

TRF1 Depletion Reveals Mutual Regulation Between Telomeres, Kinetochores, and Inner Centromeres in Mouse Oocytes

In eukaryotic chromosomes, the centromere and telomere are two specialized structures that are essential for chromosome stability and segregation. Although centromeres and telomeres often are located in close proximity to form telocentric chromosomes in mice, it remained unclear whether these two structures influence each other. Here we show that TRF1 is required for inner centromere and kinetochore assembly in addition to its role in telomere protection in mouse oocytes. TRF1 depletion caused premature chromosome segregation by abrogating the spindle assembly checkpoint (SAC) and impairing kinetochore-microtubule (kMT) attachment, which increased the incidence of aneuploidy. Notably, TRF1 depletion disturbed the localization of Survivin and Ndc80/Hec1 at inner centromeres and kinetochores, respectively. Moreover, SMC3 and SMC4 levels significantly decreased after TRF1 depletion, suggesting that TRF1 is involved in chromosome cohesion and condensation. Importantly, inhibition of inner centromere or kinetochore function led to a significant decrease in TRF1 level and telomere shortening. Therefore, our results suggest that telomere integrity is required to preserve inner centromere and kinetochore architectures, and vice versa, suggesting mutual regulation between telomeres and centromeres.

Chinese herbal medicine for immune infertility: A protocol for systematic review and meta-analysis

BACKGROUND

Infertility is a reproductive disorder caused by multiple causes and is an adverse event of reproductive health for couples in the reproductive period. Women who do not avoid sex for at least 12 months and are not pregnant are said to be infertile. 10% to 20% of infertility is caused by immune factors. At present, there is no unified diagnostic standard for immunological infertility. Clinically, it is considered that abnormal ovulation and reproductive system function of women are excluded, and no obvious pathogenic factors occur; routine examination of male semen is normal, but there is evidence of anti-reproductive immunity, thus causing infertility is immunological infertility. Traditional Chinese medicine (TCM) has a long history of treating infertility and has remarkable curative effect. It plays an important role in the treatment of gynecological and obstetrical diseases in China. The purpose of this study is to evaluate the efficacy and safety of traditional Chinese medicine for the treatment of immune infertility.

METHOD

we searched the literature from following databases: Cochrane Library, PubMed, China Biomedical Literature Database (CB), EMBASE, Chinese Journal of Science and Technology (VIP), China National Knowledge Infrastructure Database (CNKI) and Wanfang Database were searched. All the databases mentioned above will be searched from the start date to the latest version. A manual search of all references to the included trials, published randomized controlled trials (RCTs) whether blind or unblind, any languages and length of follow up were included. Treatments included Chinese medicinal herbs (single or compound). Controlls were placebo and western medicine, or no intervention. Key outcomes will include pregnancy rates, the efficiency of Chinese herbal medicine (at least one negative antibody for infertility), birth rates (the ratio of the number of pregnant women giving birth to their babies normally after herbal treatment to the total number of patients treated), recurrence rate and safety index. Two evaluators independently retrieved and extracted data and import it into Endnote X8. Then they conduct methodological evaluation on the quality of the included studies, and meta-analysis was conducted with RevMan 5.3 and Stata 13.0 software. We will use the Cochrane risk analysis tool to assess the risk of bias. Differences will be resolved by consensus or through the participation of third parties. All analysis will be performed based on the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

The purpose of this study is to evaluate the efficacy and safety of traditional Chinese herb medicine in the treatment of immune infertility.

CONCLUSION

This meta-analysis can provide evidence for clinicians to help patients make better choices.

TRIAL REGISTRATION NUMBER

INPLASY2020120073.

Mutation analysis of ZP1, ZP2, ZP3 and ZP4 genes in 152 Han Chinese samples with ovarian endometriosis

Endometriosis is characterized by the ectopic implant of endometrial tissue outside the uterine cavity and found in ˜35-50% of subfertile women. Previous studies have found that endometriosis had frequent defects in zona pellucida (ZP), and mutations in ZP genes could lead to ZP defects, raising the possibility that mutations in ZP genes might exist in endometriosis. We analyzed a total of 152 Han Chinese samples with ovarian endometriosis for the presence of mutations in the ZP1, ZP2, ZP3 and ZP4 genes. Two novel nonsynonymous ZP4 mutations were identified in three out of 152 (2.0%) samples: a p.M1?/(c.3 G > C) mutation in a 27- and 35-year-old sample, respectively, and a p.A433 V (c.1298C > T) mutation in a 31-year-old patient. No mutations were detected in ZP1, ZP2 or ZP3 genes; furthermore, no mutations in ZP genes were identified in 85 female control samples without endometriosis. The p.M1?/(c.3 G > C) mutation could lead to the usage of a downstream translation initiation site, while the evolutionary conservation and protein structural modeling analyses suggested that the p.A433 V mutation might be functionally important. However, there were strikingly different fertility outcomes among the three samples with ZP4 mutations: the p.A433V-mutated sample had no problem in fertility; while the p.M1?-mutated samples presented with paradoxical effects on fertility: the 35-year-old patient had a child while the 27-year-old patient was infertile, who underwent two spontaneous abortions and an implantation failure after IVF treatment. These results suggested that the potential role of ZP4 mutations on human fertility might be more complex than we thought, and other genetic and environment factors might play a role. In conclusion, we identified two novel mutations in the ZP4 gene in 2.0% of Han Chinese patients with ovarian endometriosis for the first time, our results suggested that mutations in ZP4, but not ZP1, ZP2 and ZP3, might play active roles in the pathogenesis of ovarian endometriosis, despite the mutation-carriers present with complex fertility outcomes.