Metabolic and epigenetic dysfunctions underlie the arrest of in vitro fertilized human embryos in a senescent-like state.

Around 60% of in vitro fertilized (IVF) human embryos irreversibly arrest before compaction between the 3- to 8-cell stage, posing a significant clinical problem. The mechanisms behind this arrest are unclear. Here, we show that the arrested embryos enter a senescent-like state, marked by cell cycle arrest, the down-regulation of ribosomes and histones and down-regulation of MYC and p53 activity. The arrested embryos can be divided into 3 types. Type I embryos fail to complete the maternal-zygotic transition, and Type II/III embryos have low levels of glycolysis and either high (Type II) or low (Type III) levels of oxidative phosphorylation. Treatment with the SIRT agonist resveratrol or nicotinamide riboside (NR) can partially rescue the arrested phenotype, which is accompanied by changes in metabolic activity. Overall, our data suggests metabolic and epigenetic dysfunctions underlie the arrest of human embryos.

Correction of the pathogenic mutation in TGM1 gene by adenine base editing in mutant embryos.

A couple diagnosed as carriers for lamellar ichthyosis, an autosomal recessive rare disease, encountered two pregnancy losses. Their blood samples showed the same heterozygous c.607C>T mutation in the TGM1 gene. However, we found that about 98.4% of the sperm had mutations, suggesting possible de novo germline mutation. To explore the probability of correcting this mutation, we used two different adenine base editors (ABEs) combined with related truncated single guide RNA (sgRNA) to repair the pathogenic mutation in mutant zygotes. Our results showed that the editing efficiency was 73.8% for ABEmax-NG combined with 20-bp-length sgRNA and 78.7% for Sc-ABEmax combined with 19-bp-length sgRNA. The whole-genome sequencing (WGS) and deep sequencing analysis demonstrated precise DNA editing. This study reveals the possibility of correcting the genetic mutation in embryos with the ABE system.

Single-cell transcriptome analysis of human oocyte ageing.

Oocyte ageing is a key bottleneck and intractable challenge for in vitro fertilization treatment of aged female patients. The underlying molecular mechanisms of human oocyte ageing remain to be elucidated. Hence, this study aims to investigate the key genes and relevant biological signalling pathways involved in human oocyte ageing. We isolated mRNA for single-cell RNA sequencing from MII human oocytes donated by patients undergoing intracytoplasmic sperm injection. Nine RNA-seq datasets were analyzed, which included 6 older patients(average 42.67±2.25 years) and 3 younger patients (average 25.67±2.08 years). 481 differentially expressed genes (DEGs) were identified, including 322 upregulated genes enriched in transcription, ubiquitination, epigenetic regulation, and cellular processes, and 159 downregulated genes enriched in ubiquitination, cell cycle, signalling pathway, and DNA repair. The STRING database was used to analyse protein-protein interactions, and the Cytoscape software was used to identify hub genes. From these DEGs, 17 hub genes were identified including 12 upregulated genes (UBE2C, UBC, CDC34, UBR1, KIF11, ASF1B, PRC1, ESPL1, GTSE1, EXO1, UBA1, KIF4A) and 5 downregulated genes (UBA52, UBE2V2, SKP1, CCNB1, MAD2L1). The significant key biological processes that are associated with these hub genes include ubiquitin-mediated proteolysis, ubiquitination-related pathways, oocyte meiosis, and cell cycle. Among these, UBE2C may play a crucial role in human oocyte ageing.

CDX2 is essential for human IVF early embryonic development.

Human in vitro fertilization (IVF) embryos usually have developmental block at 4-8 cell stages, in which only 30%-50% percent of IVF embryos develop to blastocyst stage. This is the main cause for low efficiency and repeated treatment failure in human fertility therapy. Transcription factor CDX2 is one of the key genes in human early embryonic development, which decides the differentiation from blastomere to trophoblastic lineage. However, the relationship between the developmental block of human IVF embryos and CDX2 is poorly understood. In this study, we showed that CDX2 is crucial for human IVF embryonic development. q-PCR analysis confirmed that the level of CDX2 in developmental block embryos was dramatically decreased. Immunofluorescence analysis further demonstrated that CDX2 protein level in developmental block embryos was significantly decreased compared with that in control embryos. We also addressed whether re-expression of CDX2 could rescue developmental block defects in human IVF developmental block embryos. As expected, these developmental block defects could be partially rescued by overexpression of CDX2 protein. In conclusion, these findings suggest that CDX2 plays an important role in the process of human early embryonic development.

Clinical evidence of growth hormone for infertile women with diminished ovarian reserve undergoing IVF: a systematic review and meta-analysis.

Objective: To appraise the current randomized clinical trials (RCTs) for evidence of the association of growth hormone (GH) with improved outcomes in infertile women with diminished ovarian reserve (DOR) undergoing in vitro fertilization (IVF). Methods: Relevant RCTs published in Chinese or English were identified through a comprehensive search of nine databases from the period of database inception to April 20, 2023. We included trials investigating adjuvant GH during ovarian stimulation and reported the subsequent outcomes. The group with adjuvant GH treatment and the group without adjuvant GH treatment were set up as the trial and control groups, respectively. The quality of RCTs was measured according to the Cochrane Collaboration Handbook. Results: Of the 579 studies initially identified, 10 RCTs comprising 852 infertile women with DOR were included. The GH dose of individual trials ranged between 3 and 5 IU/day. Overall, we judged the trials to be at high risk of bias in the blinding domain. Pooled results showed that GH was associated with an increased clinical pregnancy rate (RR = 1.63, 95%CI [1.31, 2.03], p < 0.0001) and a greater number of oocytes retrieved (MD = 0.91, 95%CI [0.47, 1.35], p < 0.0001). Favorable associations were also observed when ovarian stimulation was combined with GH therapy for improving the optimal embryos rate (RR = 1.84, 95%CI [1.30, 2.59], p = 0.0005) and the number of optimal embryos (MD = 0.28, 95%CI [0.08, 0.48], p = 0.005) along with reducing the cycle cancellation rate (RR = 0.46, 95%CI [0.24, 0.89], p = 0.02). Moreover, GH resulted in an increase in the fertilization rate (RR = 1.33, 95%CI [1.18, 1.50], p < 0.00001) and the embryo implantation rate (RR = 1.56, 95%CI [1.21, 2.01], p = 0.0006). In addition, there was a significant enhancement in estradiol levels (SMD = 1.18, 95%CI [0.46, 1.91], p = 0.001) and endometrial thickness (MD = 0.75, 95%CI [0.41, 1.09], p < 0.0001) on the day of hCG. With regard to the total number of days and total dose of gonadotrophins used, GH treatment was correlated with shorter days (MD = -0.26, 95%CI [-0.46, -0.06], p = 0.01) and lower dose (MD = -460.97, 95%CI [-617.20, -304.73], p < 0.00001) of gonadotrophins applied during ovarian stimulation. Furthermore, GH in conjunction with the GnRH antagonist protocol was more conducive to improving the number of oocytes retrieved when compared with the GnRH agonist protocol (p < 0.0001). Moreover, a notable association was also seen in IVF combined with GH more than or equal to 4.5 IU/day to increase the number of optimal embryos and estradiol levels on the day of hCG (p < 0.05). Conclusion: For infertile women with DOR undergoing IVF, adjuvant treatment with GH during ovarian stimulation protocols showed better clinical outcomes, shorter days and lower dosages of gonadotrophin required. Furthermore, well-designed RCTs are needed to verify our results in the future. Systematic review registration: https://www.crd.york.ac.uk PROSPERO (CRD42023421739).

The clinical value of progestin-primed ovarian stimulation protocol for women with diminished ovarian reserve undergoing IVF/ICSI: a systematic review and meta-analysis.

Background: To determine whether progestin-primed ovarian stimulation (PPOS) is more effective for women with diminished ovarian reserve (DOR) than clomiphene citrate (CC)/letrozole (LE) plus gonadotropin in IVF or ICSI treatment. Methods: Nine databases were searched until May 24, 2023, to identify relevant studies. Forest plots were used to present the results of this meta-analysis. Begg's and Egger's tests were applied to estimate publication bias. Subgroup and sensitivity analysis were performed to check the potential sources of heterogeneity and verify the robustness of the pooled results, respectively. Results: A total of 14 studies with 4182 participants were included for meta-analysis. There was evidence of a statistically notable increase in clinical pregnancy rate (OR = 1.39, 95%CI [1.01, 1.91], p = 0.05), optimal embryos rate (OR = 1.50, 95%CI [1.20, 1.88], p = 0.0004), and cumulative pregnancy rate (OR = 1.73, 95%CI [1.14, 2.60], p = 0.009), the duration and the amount of gonadotropin required (MD = 1.56, 95%CI [0.47, 2.66], p = 0.005; SMD = 1.51, 95%CI [0.90, 2.12], p < 0.00001), along with decrease cycle cancellation rate (OR = 0.78, 95%CI [0.64, 0.95], p = 0.02), luteinizing hormone (LH) level on the day of hCG (SMD = -0.81, 95%CI [-1.10, -0.53], p < 0.00001), and premature LH surge rate (OR = 0.10, 95%CI [0.07, 0.15], p < 0.00001) when PPOS was used. No evidence for publication bias within results was revealed. Conclusions: Based on evidence-based results, PPOS protocol seems to improve IVF/ICSI outcomes for women with DOR. More research with larger sample sizes and rigorous designs are required to further explore the value of PPOS among women diagnosed with DOR. Systematic review registration: www.crd.york.ac.uk, identifier CRD42023430202.

[Effects of electroacupuncture on pregnancy outcome in poor ovarian response patients of kidney essence deficiency and undergoing in vitro fertilization-embryo transfer].

OBJECTIVE: To observe the effects of electroacupuncture (EA) on ovarian reaction, egg and embryo quality, as well as pregnancy rate in poor ovarian response (POR) patients of kidney essence deficiency and undergoing in vitro fertilization-embryo transfer (IVF-ET). METHODS: Ninety-six patients who met the inclusion criteria were randomly divided into an EA group and a control group, with 48 cases in each group. Before IVF-ET, the patients in the EA group received EA, once daily, 2 or 3 treatments a week for 12 weeks. Before and after the treatment, traditional Chinese medicine (TCM) syndrome score and clinical pregnancy rate were assessed in two groups. The concentrations of serum follicle-stimulating hormone (FSH), luteinsing hormone, estradiol, progesterone and anti-mullerian hormone were detected by chemiluminescence; the contents of serum insulin-like growth factor-1, serum inhibin B (INHB) and Kisspeptin in follicular fluid were determined by enzyme linked immunosorbent assay (ELISA); the antral follicle counting (AFC) was detected by color Doppler ultrasonography; and the egg and embryo conditions were observed under microscope. Fourteen days after embryo transfer, the positive rate of serum hemchoriconic gonadotropin (HCG) and clinical pregnancy rate were calculated. RESULTS: After the treatment, the TCM syndrome score and level of serum FSH were reduced (P<0.05); the INHB in serum and AFC were increased (P<0.05) when compared with those before the treatment in the EA group. After the treatment, in comparison with the control group, the TCM syndrome score and level of serum FSH were lower (P<0.05); and the contents of serum INHB, AFC, the numbers of MⅡ eggs and high-quality embryos, as well as serum HCG positive rate were all increased (P<0.05) in the EA group. CONCLUSION: EA can relieve the clinical symptoms of TCM in POR patients of kidney essence deficiency and undergoing IVF-ET, increase the ovarian reserve, reduce the serum FSH level, and improve the content of serum INHB, and the quality of eggs and embryos. This therapy tends to improve the clinical pregnancy rate and clinical pregnancy outcome.

Effect of Bushen Yutai Recipe on IVF Patients Subjected to Mild Ovarian Stimulation.

This article investigated the effects of the traditional Chinese medicine (TCM) herbal recipe, Bushen Yutai, on in vitro fertilization (IVF) patients subjected to mild ovarian stimulation. Two hundred nineteen infertile patients were randomly divided into 2 groups: the control group and herbal treatment group. By studying, we found estrogen levels (E2) on the human chorionic gonadotropin (hCG) triggering day were significantly lower in the control group (P < 0.05), with positive blood flow being less detected by ultrasound scanning on both the day of hCG triggering and day of fresh embryo transfer for the control group (P < 0.05). Additionally, the blood flow index, retroactive and proactive inhibition, was higher in the control group, whereas the fertilization rate and number of high-quality embryos in the control group were lower than the control TCM experimental group (P < 0.01). The expression levels of the endometrial receptivity gene, vascular endothelial growth factor (VEGF), were lower in the control group vs. the TCM experimental group on the day of fresh embryo transfer (P < 0.05), whereas the rate of fresh embryo transfer in the control group was lower than the TCM experimental group (P < 0.05). In conclusion, the TCM could increase the E2 during the IVF stage, with a higher number of oocytes and higher-quality embryos. It also improved the endometrium and increased the level of VEGF gene expression. By enhancing the fresh embryo transfer rate in a minimal ovarian stimulation protocol and by improving the clinical pregnancy and ongoing pregnancy rates, the Bushen Yutai recipe could be able to increase fresh embryo transfer and higher-quality embryos.