Levels of caspase-3 and histidine-rich glycoprotein in the embryo secretome as biomarkers of good-quality day-2 embryos and high-quality blastocysts

Developmental and Molecular Effects of C-Type Natriuretic Peptide Supplementation in In Vitro Culture of Bovine Embryos

The use of C-type natriuretic peptide (CNP) in the interaction with the oocyte and in the temporary postponement of spontaneous meiosis resumption has already been well described. However, its action in pre-implantation developmental-stage embryos is yet to be understood. Thus, our study aimed to detect the presence of the canonical CNP receptor (natriuretic peptide receptor, NPR2) in germinal vesicle (GV)-, metaphase II (MII)-, presumptive zygote (PZ)-, morula (MO)-, and blastocyst (BL)-stage embryos and, later, to observe possible modulations on the embryos when co-cultured with CNP. In Experiment I, we detected and quantified NPR2 on the abovementioned embryo stages. Further, in Experiment II, we intended to test different concentrations (100, 200, or 400 nM of CNP) at different times of inclusion in the in vitro culture (IVC; inclusion from the beginning, i.e., day 1, or from day 5). In Experiment III, 400 nM of CNP was used on day 1 (D1) in the IVC, which was not demonstrated to be embryotoxic, and it showed potentially promising results in the blastocyst production rate when compared to the control. Thus, we analyzed the embryonic development rates of bovine embryos (D7) and hatching kinetics (D7, D8, and D9). Subsequently, morula and blastocyst were collected and evaluated for transcript abundance of their competence and quality (apoptosis, oxidative stress, proliferation, and differentiation) and lipid metabolism. Differences with probabilities less than p < 0.05, and/or fold change (FC) > 1.5, were considered significant. We demonstrate the presence of NPR2 until the blastocyst development stage, when there was a significant decrease in membrane receptors. There was no statistical difference in the production rate after co-culture with 400 nM CNP. However, when we evaluated the abundance of morula transcripts, there was an upregulated transcription in ADCY6 (p = 0.057) and downregulated transcripts in BMP15 (p = 0.013), ACAT1 (p = 0.040), and CASP3 (p = 0.082). In addition, there was a total of 12 transcriptions in morula that presented variation FC > 1.5. In blastocysts, the treatment with CNP induced upregulation in BID, CASP3, SOX2, and HSPA5 transcripts and downregulation in BDNF, NLRP5, ELOVL1, ELOVL4, IGFBP4, and FDX1 transcripts (FC > 1.5). Thus, our study identified and quantified the presence of NPR2 in bovine pre-implantation embryos. Furthermore, 400 nM of CNP in IVC, a concentration not previously described in the literature, modulated some transcripts related to embryonic metabolism, and this was not embryotoxic morphologically.

Implementing a preimplantation proteomic approach to advance assisted reproduction technologies in the framework of predictive, preventive, and personalized medicine

The evolution of the field of assisted reproduction technology (ART) in the last 40 years has significantly contributed to the management of global infertility. Despite the great numbers of live births that have been achieved through ART, there is still potential for increasing the success rates. As a result, there is a need to create optimum conditions in order to increase ART efficacy. The selection of the best sperm, oocyte, and embryo, as well as the achievement of optimal endometrial receptivity, through the contribution of new diagnostic and treatment methods, based on a personalized proteomic approach, may assist in the attainment of this goal. Proteomics represent a powerful new technological development, which seeks for protein biomarkers in human tissues. These biomarkers may aid to predict the outcome, prevent failure, and monitor in a personalized manner in vitro fertilization (IVF) cycles. In this review, we will present data from studies that have been conducted in the search for such biomarkers in order to identify proteins related to good sperm, oocyte, and embryo quality, as well as optimal endometrial receptivity, which may later lead to greater results and the desirable ART outcome.

Evaluation of the TMRW vapor phase cryostorage platform using reproductive specimens and in vitro extended human embryo culture

OBJECTIVE

To assess the impact of shipment and storage of sperm, oocytes, and blastocysts in vapor phase nitrogen compared with static storage in liquid phase nitrogen.

DESIGN

Prospective cohort-matched study.

SETTING

Multiple in vitro fertilization laboratories in an in vitro fertilization network.

PATIENT(S)

Fifty-eight human embryos, 32 human oocytes, 15 units of bovine semen.

INTERVENTION(S)

Vapor vs. liquid nitrogen.

MAIN OUTCOME MEASURE(S)

The postwarming survival of oocytes, sperm, and blastocysts, and the developmental potential of blastocysts during in vitro extended culture.

RESULT(S)

Custom-designed labware, for use with the TMRW platform, enables continuous temperature monitoring during shipment and/or storage in the vapor phase robotic storage system. The highest temperature recorded for specimens shipped to a domestic laboratory was -180.2 °C with a mean ± SD of -190.4 ± 0.5 °C during shipment and -181.1 ± 0.6 °C during storage. Likewise, specimens shipped internationally had a high of -180.2 °C with a mean ± SD of -193.5 ± 0.6 °C during shipment and -181.2 ± 0.7 °C during storage. Results from the extended culture assays have revealed no deleterious effect of shipment and storage in nitrogen vapor. The viability of mammalian gametes and embryos was equivalent between the vapor phase and liquid phase storage.

CONCLUSION(S)

The evaluated system did not have any deleterious effects on the postwarming survival of sperm, oocytes, and blastocysts. The postwarming developmental potential of human blastocysts during in vitro extended culture was unaffected by storage and handling in the vapor phase nitrogen TMRW platform when compared with static liquid phase nitrogen storage. Our results suggest that the vapor phase cryostorage platform is a safe system to handle and store reproductive specimens for human assisted reproductive technology.

Histidine-rich glycoprotein (HRGP): Pleiotropic and paradoxical effects on macrophage, tumor microenvironment, angiogenesis, and other physiological and pathological processes

Histidine-rich glycoprotein (HRGP) is a relatively less known glycoprotein, but it is abundant in plasma with a multidomain structure, which allows it to interact with many ligands and regulate various biological processes. HRGP ligands includes heme, Zn²⁺, thrombospondin, plasmin/plasminogen, heparin/heparan sulfate, fibrinogen, tropomyosin, IgG, FcγR, C1q. In many conditions, the histidine-rich region of HRGP strengthens ligand binding following interaction with Zn²⁺ or exposure to low pH, such as sites of tissue injury or tumor growth. The multidomain structure and diverse ligand binding attributes of HRGP indicates that it can act as an extracellular adaptor protein, connecting with different ligands, especially on cell surfaces. Also, HRGP can selectively target IgG, which blocks the production of soluble immune complexes. The most common cell surface ligand of HRGP is heparan sulfate proteoglycan, and the interaction is also potentiated by elevated Zn²⁺ concentration and low pH. Recent reports have shown that HRGP can modulate macrophage polarization and possibly regulate other physiological processes such as angiogenesis, anti-tumor immune response, fibrinolysis and coagulation, soluble immune complex clearance and phagocytosis of apoptotic/necrosis cells. In addition, it has also been reported that HRGP has antibacterial and anti-HIV infection effects and may be used as a novel clinical biomarker accordingly. This review outlines the molecular, structural and biological properties of HRGP as well as presenting an update on the function of HRGP in various physiological processes.

Molecular Drivers of Developmental Arrest in the Human Preimplantation Embryo: A Systematic Review and Critical Analysis Leading to Mapping Future Research

Developmental arrest of the preimplantation embryo is a multifactorial condition, characterized by lack of cellular division for at least 24 hours, hindering the in vitro fertilization cycle outcome. This systematic review aims to present the molecular drivers of developmental arrest, focusing on embryonic and parental factors. A systematic search in PubMed/Medline, Embase and Cochrane-Central-Database was performed in January 2021. A total of 76 studies were included. The identified embryonic factors associated with arrest included gene variations, mitochondrial DNA copy number, methylation patterns, chromosomal abnormalities, metabolic profile and morphological features. Parental factors included, gene variation, protein expression levels and infertility etiology. A valuable conclusion emerging through critical analysis indicated that genetic origins of developmental arrest analyzed from the perspective of parental infertility etiology and the embryo itself, share common ground. This is a unique and long-overdue contribution to literature that for the first time presents an all-inclusive methodological report on the molecular drivers leading to preimplantation embryos’ arrested development. The variety and heterogeneity of developmental arrest drivers, along with their inevitable intertwining relationships does not allow for prioritization on the factors playing a more definitive role in arrested development. This systematic review provides the basis for further research in the field.

Circulating MMP-7 and VEGF as potential predictive biomarkers for recurrent implantation failures

Recurrent implantation failure (RIF) is considered to be one of the major limiting factors of assisted reproductive technology (ART) programme success. The current study focused on the investigation of matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), cytokines and cell adhesion molecules in peripheral blood (PB) and follicular fluid (FF) obtained from 44 women aged between 25 and 39 years old and undergoing intracytoplasmic sperm injection (ICSI). These women were divided into two groups: 22 RIF women with embryo implantation failures after the transfer of at least four fresh or frozen-thawed good quality embryos in a minimum of three ICSI cycles, and 22 ICSI success women (controls) who achieved a clinical pregnancy at their first ICSI attempt. The PB and FF samples were obtained from each patient on the day of oocyte retrieval. MMP-1, -2, -3, -7, -9, TIMP-1, -2, vascular endothelial growth factor (VEGF), leukaemia inhibitory factor (LIF), vascular cell adhesion molecule 1 (VCAM1) and intercellular adhesion molecules 1 (ICAM1) were analyzed using enzyme-linked immunosorbent assay of PB and FF. Our results showed significant decreases in PB MMP-7 and PB VEGF in the RIF group compared with controls [281.11 (33-614) pg/ml vs 119.92 (27-441) pg/ml; P-value = 0.030] and [82.54 (25.94-210.20) pg/ml vs 30.93 (13.62-193.33) pg/ml; P-value = 0.022; respectively]. Receiver operating characteristic (ROC) curve analysis showed informative area under the curve values for PB MMP-7, as well as for PB VEGF, making them able to be proposed as biomarkers of the RIF. Therefore, circulating MMP-7 and VEGF seem to play an interesting role in embryo implantation in in vitro fertilization (IVF)/ICSI cycles and could be proposed as circulating biomarkers of the RIF. These results could be helpful for clinicians and patients to choose the best rescue strategy and treatment to minimize implantation failure in women undergoing IVF/ICSI procedures after the first attempt.

Oxidative stress markers in the follicular fluid of patients with polycystic ovary syndrome correlate with a decrease in embryo quality

PURPOSE

Elevated oxidative stress has been proposed as an important factor in the pathogenesis of polycystic ovary syndrome (PCOS)-related infertility. Our study was aimed at simultaneously exploring local and systemic oxidative stress in PCOS individuals and its relationship with embryo quality.

METHODS

We recruited 86 PCOS cases and 60 controls. Five representative oxidative stress markers, namely, total oxidant capacity (TOC), total antioxidant capacity (TAC), malonaldehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD), were measured in both follicular fluid (FF) and serum.

RESULTS

Women with PCOS compared to normal controls had higher levels of TOC in both FF (10.13 ± 2.68 vs.7.03 ± 2.45, P < 0.001) and serum (11.76 ± 2.92 vs. 8.82 ± 2.57, P < 0.001). The oxidative stress index (OSI, the ratio of TOC to TAC) was also higher in PCOS cases. They were still significant after BMI adjustment (Padj<0.01). In addition, the serum OSI level was much higher than the FF OSI level in both groups. Correlation analysis showed that the FF and serum TOC were negatively correlated with the high-quality embryo rate on day 3 and the later blastocyst formation rate in the PCOS group (P < 0.05). The correlation coefficient was higher in FF. Moreover, as the regression analysis data showed, the FF MDA level was significantly associated with embryo quality indicators (P < 0.05).

CONCLUSIONS

PCOS was accompanied by elevated oxidative stress in both serum and FF. Even though serum oxidative stress was severe, the study suggested that FF oxidative stress contributed more to embryo quality, to which we should give more attention in the future.

Spontaneous in vitro hatching of the human blastocyst: the proteomics of initially hatching cells

Spontaneous in vitro hatching of human blastocysts starts with the formation of a tunnel through the zona pellucida (ZP) by cellular projections of trophoblast cells. Our aim was to identify the proteins that are upregulated in these initially hatching cells as compared to trophectoderm (TE) cells from blastocysts that had not yet hatched. Forty seven women that underwent assisted reproduction treatment donated their ICSI-derived polyploid blastocysts for the study. In polyploid blastocysts that started spontaneous hatching, hatched clusters of cells were collected from the outer side of the ZP. Liquid chromatography mass spectrometry was applied to determine the proteins that were upregulated in these cells as compared to TE cells obtained from inside the ZP. Whole non-hatched polyploid blastocysts were used as controls. Overall 1245 proteins were identified in all samples. Forty nine proteins were significantly upregulated in hatching cells and 17 in the TE cells. There was minimal overlap between hatching and TE samples; only serine protease inhibitors (SERPINS) and lipocalin were detected in both samples. Myosin and actin were highly upregulated in the hatching cells as well as paraoxonase, N-acetylmuramoyl alanine amidase, and SERPINS clade A and galectin. In the TE cells, gamma butyrobetaine dioxygenase, lupus La protein, sialidase, lysosomal Pro-X carboxypeptidase, phospholipase b, and SERPINS clade B and A were among the most highly upregulated proteins. These findings may contribute to the basic knowledge of the molecular behavior of the specific cells that actively perforate the glycoprotein matrix of the ZP.

Non-invasive Embryo Assessment: Altered Individual Protein Profile in Spent Culture Media from Embryos Transferred at Day 5

In order to improve ART outcome, non-invasive embryo assessment is gaining more and more attention. Therefore, the aim of this study is to determine the consecutive implantation potential via the secretome between blastocysts with or without implantation and to analyse possible interactions between these differentially expressed proteins. In this prospective study, 69 spent culture media from blastocysts transferred at day 5 were collected from patients undergoing IVF/ICSI treatment in a single IVF centre between April 2015 and November 2018 after informed consent and analysed individually. Exclusion criteria were the absence of informed consent, PCOS, endometriosis and maternal age > 42 years. Dependent on the treatment outcome, media were subsequently divided into two groups: from embryos who implanted successfully (n = 37) and from embryos without implantation (n = 32). Ninety-two proteins were measured simultaneously using the proximity extension assay (PEA) technology with the Olink® CVD III panel employing oligonucleotide-labelled antibodies. Statistical analysis was performed using the Kolmogorov-Smirnov test, Student's t test, the Mann-Whitney U test and Fisher's exact test. Media from implanted blastocysts showed significantly higher expression of EPHB4, ALCAM, CSTB, BMH, TIMP4, CCL24, SELE, FAS, JAM-A, PON3, PDGF-A, vWF and PECAM-1 compared with media from blastocysts without subsequent implantation. The highest relative expression change could be demonstrated for PECAM-1 and TIMP4. PECAM-1, SELE and vWF were co-expressed. Especially EPHB 4, SELE, ALCAM, MCP-1, CCL24, FAS, JAM-A and PDGF-A have already been described in early embryonic development and metabolism. Therefore, these proteins together with PECAM-1 indicate possible biomarkers for non-invasive embryo assessment in the future. However, due to the innovative methodology, defining a threshold for the use as biomarkers remains to be assessed.