scholarly journals Oocyte Morphometric Assessment and Gene Expression Profiling of Oocytes and Cumulus Cells as Biomarkers of Oocyte Competence in Sheep

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2818
Author(s):  
Carolina Maside ◽  
Irene Sánchez-Ajofrín ◽  
Daniela Medina-Chávez ◽  
Benner Alves ◽  
José Julián Garde ◽  
...  
Keyword(s):  
Gene Expression ◽  
Assisted Reproductive Technologies ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Oocyte Quality ◽  
Blastocyst Stage ◽  
Morphometric Parameters ◽  
Oocyte Diameter ◽  
Relative Gene Expression ◽  
Relative Gene

Oocyte quality is crucial for subsequent embryo development and so it is a major challenge in assisted reproductive technologies. The aim of the present work was to evaluate the morphometric parameters of oocytes (experiment 1) and the relative gene expression of oocytes and cumulus cells (CCs) (experiment 2) as biomarkers of oocyte quality after individually culturing them (one oocyte or embryo/drop). In experiment 1, individually matured oocytes were measured and classified into small, intermediate, and large oocytes after a cluster analysis, based on total diameter (with zona pellucida, ZP), oocyte diameter (without ZP), and ZP thickness. These oocytes were individually fertilized in vitro and cultured. The embryo development was evaluated up to the blastocyst stage. According to the total diameter, oocyte diameter, and ZP thickness, the blastocyst rate decreased in the small oocytes group (3.1 ± 3.1, 14.1 ± 9.4, and 26.7 ± 3.9, respectively) compared to the intermediate (29.4 ± 5.2, 30.5 ± 10.1, and 28.6 ± 9.6, respectively) and large oocytes groups (54.2 ± 13.5, 44.4 ± 3.9, and 67.6 ± 12.4, respectively). In addition, the probability of reaching the blastocyst stage was positively related to the total diameter (p < 0.001), oocyte diameter (p < 0.05), and ZP thickness (p < 0.001). Furthermore, the relative gene expression of BAX, BCL2, GDF9, and GJA1 was lower in oocytes classified as large. In experiment 2, the mRNA transcript relative abundance pattern of genes in CCs was evaluated according to oocyte total diameter and developmental stage reached. CCs from oocytes classified as large and oocytes capable of developing to the blastocyst stage had a lower relative expression of BAX, STAR, and PTGS2, while a higher expression of HAS2 and SDC2 transcript was observed for those oocytes. In conclusion, oocyte morphometric parameters and gene expression analysis in oocytes and CCs provide methods for the identification of the most competent oocytes for assisted reproductive technologies in sheep.

scholarly journals Quadrupling efficiency in production of genetically modified pigs through improved oocyte maturation

2017 ◽  
Vol 114 (29) ◽  
pp. E5796-E5804 ◽  
Author(s):  
Ye Yuan ◽  
Lee D. Spate ◽  
Bethany K. Redel ◽  
Yuchen Tian ◽  
Jie Zhou ◽  
...  
Keyword(s):  
Assisted Reproductive Technologies ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Oocyte Quality ◽  
Blastocyst Stage ◽  
Vitro Fertilization ◽  
Fourfold Increase

Assisted reproductive technologies in all mammals are critically dependent on the quality of the oocytes used to produce embryos. For reasons not fully clear, oocytes matured in vitro tend to be much less competent to become fertilized, advance to the blastocyst stage, and give rise to live young than their in vivo-produced counterparts, particularly if they are derived from immature females. Here we show that a chemically defined maturation medium supplemented with three cytokines (FGF2, LIF, and IGF1) in combination, so-called “FLI medium,” improves nuclear maturation of oocytes in cumulus–oocyte complexes derived from immature pig ovaries and provides a twofold increase in the efficiency of blastocyst production after in vitro fertilization. Transfer of such blastocysts to recipient females doubles mean litter size to about nine piglets per litter. Maturation of oocytes in FLI medium, therefore, effectively provides a fourfold increase in piglets born per oocyte collected. As they progress in culture, the FLI-matured cumulus–oocyte complexes display distinctly different kinetics of MAPK activation in the cumulus cells, much increased cumulus cell expansion, and an accelerated severance of cytoplasmic projections between the cumulus cells outside the zona pellucida and the oocyte within. These events likely underpin the improvement in oocyte quality achieved by using the FLI medium.

scholarly journals Human Cumulus Cells in Long-Term In Vitro Culture Reflect Differential Expression Profile of Genes Responsible for Planned Cell Death and Aging—A Study of New Molecular Markers

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1265
Author(s):  
Błażej Chermuła ◽  
Wiesława Kranc ◽  
Karol Jopek ◽  
Joanna Budna-Tukan ◽  
Greg Hutchings ◽  
...  
Keyword(s):  
Cell Death ◽  
In Vitro Culture ◽  
Expression Analysis ◽  
Assisted Reproductive Technologies ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Oocyte Quality ◽  
Genetic Profile

In the ovarian follicle, maturation of the oocyte increases in the presence of somatic cells called cumulus cells (CCs). These cells form a direct barrier between the oocyte and external environment. Thanks to bidirectional communication, they have a direct impact on the oocyte, its quality and development potential. Understanding the genetic profile of CCs appears to be important in elucidating the physiology of oocytes. Long-term in vitro culture of CCs collected from patients undergoing controlled ovarian stimulation during in vitro fertilization procedure was conducted. Using microarray expression analysis, transcript levels were assessed on day 1, 7, 15, and 30 of culture. Apoptosis and aging of CCs strictly influence oocyte quality and subsequently the outcome of assisted reproductive technologies (ART). Thus, particular attention was paid to the analysis of genes involved in programmed cell death, aging, and apoptosis. Due to the detailed level of expression analysis of each of the 133 analyzed genes, three groups were selected: first with significantly decreased expression during the culture; second with the statistically lowest increase in expression; and third with the highest significant increase in expression. COL3A1, SFRP4, CTGF, HTR2B, VCAM1, TNFRSF11B genes, belonging to the third group, were identified as potential carriers of information on oocyte quality.

Neither gonadotropin nor cumulus cell expansion is needed for the maturation of competent porcine oocytes in vitro

2021 ◽  
Author(s):  
Bethany K Redel ◽  
Lee D Spate ◽  
Ye Yuan ◽  
Clifton N Murphy ◽  
R Michael Roberts ◽  
...  
Keyword(s):  
Assisted Reproductive Technologies ◽  
Cumulus Cell ◽  
Reproductive Technologies ◽  
Oocyte Quality ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Oocyte Competence ◽  
Key Indicator ◽  
Cytoplasmic Competence

Abstract In vitro maturation of oocytes from immature females is widely used in assisted reproductive technologies. Here we illustrate that cumulus cell (CC) expansion, once considered a key indicator of oocyte quality, is not needed for oocytes to mature to the metaphase II (MII) stage and to gain nuclear and cytoplasmic competence to produce offspring. Juvenile pig oocytes were matured in four different media: 1) Basal (−gonadotropins (GN)-FLI); 2) -GN + FLI (supplement of FGF2, LIF, and IGF1); 3) + GN-FLI; 4) + GN + FLI. There was no difference in maturation to MII or progression to the blastocyst stage after fertilization of oocytes that had been matured in -GN + FLI medium and oocytes matured in +GN + FLI medium. Only slight CC expansion occurred in the two media lacking GN compared to the two where GN was present. The cumulus-oocytes-complexes (COC) matured in +GN + FLI exhibited the greatest expansion. We conclude that FLI has a dual role. It is directly responsible for oocyte competence, a process where GN are not required, and, when GN are present, it has a downstream role in enhancing CC expansion. Our study also shows that elevated phosphorylated MAPK may not be a necessary correlate of oocyte maturation and that the greater utilization of glucose by COC observed in +GN + FLI medium probably plays a more significant role to meet the biosynthetic needs of the CC to expand than to attain oocyte developmental competence. Gene expression analyses have not been informative in providing a mechanism to explain how FLI medium enhances oocyte competence without promoting CC expansion.

Mechanism of the adverse effect of hyaluronidase used for oocyte denudation on early development of bovine embryos

Zygote ◽  
2021 ◽  
pp. 1-5
Author(s):  
Shiori Ashibe ◽  
Kanade Irisawa ◽  
Ken Yokawa ◽  
Yoshikazu Nagao
Keyword(s):  
Treatment Group ◽  
Assisted Reproductive Technologies ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Control Group ◽  
Free Calcium ◽  
Parthenogenetic Development ◽  
Early Embryos ◽  
Bovine Oocytes

Summary Hyaluronidase is widely used in animal and human assisted reproductive technologies (ARTs) to remove cumulus cells around oocytes. However, adverse effects of hyaluronidase treatment, such as increased rates of degeneration and parthenogenesis, have been found after treatment of human and mouse oocytes. Currently, the mechanism(s) of the detrimental effects are unclear. The present study was initiated to identify the mechanism of adverse responses to hyaluronidase treatment in bovine oocytes and early embryos. Cumulus cells were removed from cumulus–oocyte complexes (COCs) with or without hyaluronidase and the oocytes were subjected to intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF). Significantly lower rates of blastocyst formation were obtained in the hyaluronidase treatment group after ICSI (22.4%) and IVF (21.2%) compared with the non-hyaluronidase control groups: 36.1% after ICSI and 30.4% after IVF. Next, we examined the effect of hyaluronidase on parthenogenetic development rates and on the cytoplasmic levels of free calcium ions (Ca2+), reactive oxygen species (ROS) and reduced glutathione (GSH). No differences in parthenogenesis rates were found between treated and untreated groups. Ca2+ levels in oocytes from the hyaluronidase treatment group indicated using mean fluorescence intensity were significantly higher (68.8 ± 5.3) compared with in the control group (45.0 ± 2.5). No differences were found in the levels of ROS or GSH between the treated and untreated groups. We conclude that hyaluronidase might trigger an increase in Ca2+ levels in oocytes, resulting in a decreased potential for normal embryonic development.

scholarly journals Influence of Angiopoietin Treatment with Hypoxia and Normoxia on Human Intervertebral Disc Progenitor Cell’s Proliferation, Metabolic Activity, and Phenotype

2021 ◽  
Vol 11 (15) ◽  
pp. 7144
Author(s):  
Muriel C. Bischof ◽  
Sonja Häckel ◽  
Andrea Oberli ◽  
Andreas S. Croft ◽  
Katharina A. C. Oswald ◽  
...  
Keyword(s):  
Gene Expression ◽  
Intervertebral Disc ◽  
Metabolic Activity ◽  
Cell Metabolism ◽  
Trauma Patients ◽  
Low Back ◽  
Relative Gene Expression ◽  
Progenitor Cell Population ◽  
Ivd Degeneration ◽  
Relative Gene

Increasing evidence implicates intervertebral disc (IVD) degeneration as a major contributor to low back pain. In addition to a series of pathogenic processes, degenerated IVDs become vascularized in contrast to healthy IVDs. In this context, angiopoietin (Ang) plays a crucial role and is involved in cytokine recruitment, and anabolic and catabolic reactions within the extracellular matrix (ECM). Over the last decade, a progenitor cell population has been described in the nucleus pulposus (NP) of the IVD to be positive for the Tie2 marker (also known as Ang-1 receptor). In this study, we investigated the influence of Ang-1 and Ang-2 on human NP cell (Tie2+, Tie2- or mixed) populations isolated from trauma patients during 7 days in normoxia (21% O2) or hypoxia (≤ 5% O2). At the end of the process, the proliferation and metabolic activity of the NP cells were analyzed. Additionally, the relative gene expression of NP-related markers was evaluated. NP cells showed a higher proliferation depending on the Ang treatment. Moreover, the study revealed higher NP cell metabolism when cultured in hypoxia. Additionally, the relative gene expression followed, with an increase linked to the oxygen level and Ang concentration. Our study comparing different NP cell populations may be the start of new approaches for the treatment of IVD degeneration.

scholarly journals Molecular Mechanisms Responsible for Increased Vulnerability of the Ageing Oocyte to Oxidative Damage

2017 ◽  
Vol 2017 ◽  
pp. 1-22 ◽  
Author(s):  
Bettina P. Mihalas ◽  
Kate A. Redgrove ◽  
Eileen A. McLaughlin ◽  
Brett Nixon
Keyword(s):  
Oxidative Damage ◽  
Molecular Mechanisms ◽  
Spindle Assembly Checkpoint ◽  
Assisted Reproductive Technologies ◽  
Reproductive Technologies ◽  
Oocyte Quality ◽  
Protein Repair ◽  
Protective Mechanisms ◽  
Pronounced Increase ◽  
Age Related

In their midthirties, women experience a decline in fertility, coupled to a pronounced increase in the risk of aneuploidy, miscarriage, and birth defects. Although the aetiology of such pathologies are complex, a causative relationship between the age-related decline in oocyte quality and oxidative stress (OS) is now well established. What remains less certain are the molecular mechanisms governing the increased vulnerability of the aged oocyte to oxidative damage. In this review, we explore the reduced capacity of the ageing oocyte to mitigate macromolecular damage arising from oxidative insults and highlight the dramatic consequences for oocyte quality and female fertility. Indeed, while oocytes are typically endowed with a comprehensive suite of molecular mechanisms to moderate oxidative damage and thus ensure the fidelity of the germline, there is increasing recognition that the efficacy of such protective mechanisms undergoes an age-related decline. For instance, impaired reactive oxygen species metabolism, decreased DNA repair, reduced sensitivity of the spindle assembly checkpoint, and decreased capacity for protein repair and degradation collectively render the aged oocyte acutely vulnerable to OS and limits their capacity to recover from exposure to such insults. We also highlight the inadequacies of our current armoury of assisted reproductive technologies to combat age-related female infertility, emphasising the need for further research into mechanisms underpinning the functional deterioration of the ageing oocyte.

P–219 mtDNA content in bovine cumulus cells does not predict oocytés developmental competence

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Á Martíne. Moro ◽  
I Lamas-Toranzo ◽  
L González-Brusi ◽  
A Pérez-Gómez ◽  
P Bermejo-Álvarez
Keyword(s):  
Cumulus Cell ◽  
Cumulus Cells ◽  
Oocyte Quality ◽  
Blastocyst Stage ◽  
Early Embryo ◽  
Developmental Competence ◽  
Success Rates ◽  
Developmental Potential ◽  
Mtdna Sequence

Abstract Study question Does cumulus cell mtDNA content correlate with oocyte developmental potential in the bovine model? Summary answer The relative amount of mtDNA content did not vary significantly in oocytes showing different developmental outcomes following IVF What is known already Cumulus cells are closely connected to the oocyte through transzonal projections, serving essential metabolic functions during folliculogenesis. These oocyte-supporting cells are removed and discarded prior to ICSI, thereby constituting an interesting biological material on which to perform molecular analysis aimed to predict oocyte developmental competence. Previous studies have positively associated oocytés mtDNA content with developmental potential in both animal models and women. However, it remains debatable whether mtDNA content in cumulus cells could be used as a proxy to infer oocyte developmental potential. Study design, size, duration Bovine cumulus cells were allocated into three groups according to the developmental potential of the oocyte: 1) oocytes developing to blastocysts following IVF (Bl+Cl+), 2) oocytes cleaving following IVF but arresting their development prior to the blastocyst stage (Bl-Cl+), and 3) oocytes not cleaving following IVF (Bl-Cl-). Relative mtDNA content was analysed in 40 samples/group, each composed by the cumulus cells from one cumulus-oocyte complex (COC). Participants/materials, setting, methods Bovine cumulus-oocyte complexes were obtained from slaughtered cattle and individually matured in vitro (IVM). Following IVM, cumulus cells were removed by hyaluronidase treatment, pelleted, snap frozen in liquid nitrogen and stored at –80 ºC until analysis. Cumulus-free oocytes were fertilized and cultured in vitro individually and development was recorded for each oocyte. Relative mtDNA abundance was determined by qPCR, amplifying a mtDNA sequence (COX1) and a chromosomal sequence (PPIA). Statistical differences were tested by ANOVA. Main results and the role of chance Relative mtDNA abundance did not differ significantly (ANOVA p &gt; 0.05) between the three groups exhibiting different developmental potential (1±0.06 vs. 1.19±0.05 vs. 1.11±0.05, for Bl+Cl+ vs. Bl-Cl+ vs. Bl-Cl-, mean±s.e.m.). Limitations, reasons for caution Experiments were conducted in the bovine model. Although bovine folliculogenesis, monoovulatory ovulation and early embryo development exhibit considerable similarities with that of humans, caution should be taken when extrapolating these data to humans. Wider implications of the findings: The use of molecular markers for oocyte developmental potential in cumulus cells could be used to enhance success rates following single-embryo transfer. Unfortunately, mtDNA in cumulus cells was not found to be a good proxy for oocyte quality. Trial registration number Not applicable

The birth of a healthy child in the assisted reproductive technologies program after autologous co-culture of embryo with cumulus cells and a new CAT transfer technology. Case report

GYNECOLOGY ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 270-274
Author(s):  
Gunai R. Asfarova ◽  
Veronika I. Smol'nikova ◽  
Natalia P. Makarova ◽  
Iuliia S. Drapkina ◽  
Anastasiia P. Sysoeva ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Healthy Child ◽  
Assisted Reproductive Technologies ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Biologically Active ◽  
Human Embryos ◽  
Implantation Failure ◽  
Recurrent Implantation Failure ◽  
Art Programs

Cumulus cells are essential during oocytes growth and development, as well as during their maturation and fertilization. Research results have shown that embryo co-cultivation with autologous cumulus cells increases the frequency of blastocyst formation, and also improves the effectiveness of ART programs. Embryo transfer in such programs is recommended to be carried out using the CAT technology (Cumulus-Aided embryo Transfer), which includes embryo cultivation on a layer of cumulus cells and embryo transfer with a certain amount of diluted cumulus cells. Patient G., 38 years old, came to the department with infertility for 15 years and recurrent implantation failure in history. The patient had ART program with autologous co-cultivation of embryos with cumulus cells and a new CAT transfer technology. The patient fell pregnant and gave birth to a healthy child. Autologous cumulus cells can be a source of biologically active substances and improve embryological parameters and implantation rate in ART programs. Embryo co-cultivation with cumulus cells is especially important for patients with recurrent implantation failure. This technique can become an alternative for optimizing human embryos culturing.

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