Oocyte retrieval and selection
David K. Gardner, Ariel Weissman, Colin M. Howles, Zeev Shoham in Textbook of Assisted Reproductive Techniques, 2017
Cumulus cells are Graafian follicular cells that surround and nourish the oocyte during its development in the ovary. The innermost layer of cumulus cells, immediately adjacent to the ZP, is called corona radiata. Cells of the corona radiata extend their cytoplasm toward the oocyte through the ZP. Communication (either paracrine interaction or gap junction) occurs between the oocyte and the cumulus-corona cells. Such interactions allow oocyte nutrition and maturation during its preovulatory growth from the diplotene to the MII stage (102, 103). Corona radiata and cumulus cells maintain their contact with the oocyte at the time of ovulation, during a normal menstrual cycle, or after withdrawal by aspiration, in hormonally stimulated assisted reproduction cycles.
Regulation of Reproduction by Dopamine
Nira Ben-Jonathan in Dopamine, 2020
A fully grown oocyte is tightly surrounded by compact layers of specialized granulosa cells (cumulus cells), forming a cumulus–oocyte complex. The process of meiosis resumption requires integration of endocrine, paracrine and autocrine signaling pathways involving interactions between the oocyte and the surrounding granulosa and cumulus cells. Ovulation occurs only once the first meiotic division has completed and a secondary oocyte has been formed within the dominant follicle. As discussed in Section 10.6, the completion of oogenesis (stage 5) occurs at the time of fertilization, when the secondary oocyte completes meiosis II and produces a very large, mature haploid ovum that unites with the sperm. The different stages of oogenesis and folliculogenesis are presented in Table 10.3 and illustrated in Figure 10.11.
Capacitation, the Acrosome Reaction, and Motility in Mammalian Sperm
Claude Gagnon in Controls of Sperm Motility, 2020
The cumulus is comprised of cumulus cells derived from the follicular cells surrounding the developing oocyte and various macromolecular and ionic components secreted by the cumulus cells or derived from follicular fluid. Since the discovery of the acrosome reaction more than 30 years ago, investigators have searched among these components for a specific inducer of the reaction. Interpretation of results obtained from incubating spermatozoa with putative inducing factors from the cumulus have been fraught with problems, most of which stem from separating the effect of factors on capacitation from their effect on the acrosome reaction. Apparently, acrosome reactions can occur spontaneously in some capacitated sperm; therefore, a factor that appears to induce the acrosome reaction may only be hastening the process of capacitation. This would be the case if the factor only increases the percentage of acrosome-reacted sperm when it has been incubated with sperm for long periods (hours instead of minutes). On the other hand, if a factor does not induce acrosome reactions, it may be that the sperm were not capacitated sufficiently to expose receptors for the factor.
Association of IL-17 and IL-23 follicular fluid concentrations and gene expression profile in cumulus cells from infertile women at risk for ovarian hyperstimulation syndrome
Published in Human Fertility, 2020
Leila Motamedzadeh, Mohammad Mahdi Mohammadi, Hossein Hadinedoushan, Ehsan Farashahi Yazd, Farzaneh Fesahat
In the present study, we used the cumulus cells associated with the oocytes of the case and the control groups for the evaluation of gene expression. The oocytes are surrounded by several layers of cumulus cells that have essential roles in oocyte development by paracrine signals like carbohydrate metabolism (Rienzi, Balaban, Ebner, & Mandelbaum, 2012). Lee et al. (2017) concluded that IL-6 and tumour necrosis factor-α mRNA expression in granulosa cells has not displayed significant changes in the case and control group (Lee et al., 2017). Ovarian granulosa cells and cumulus cells are expressed and respond to innate immune cell-related surveillance proteins and cytokines, such as IL-6, during ovulation (Richards, Liu, & Shimada, 2008). Contrary to the significant higher rates of FF IL-17 level in this study, there was no significant increase of mRNA level of IL-17. Different regulatory levels of gene expression have been proven at transcription, alternative splicing, translation, and post-translational modifications as well as differences in expression levels in various tissues (Schwanhäusser et al., 2011). Therefore, the discrepancy in expression of IL-17 on protein and mRNA levels in the two different sites, one in the FF and the other in the cumulus cells, is not unexpected.
Application of ultrasound markers measured at different time points of COH cycle in the prediction of ovarian response for individualised ovulation induction
Published in Journal of Obstetrics and Gynaecology, 2022
Yue-Wei Li, Xiao-Wen Liang, Jing-Hui Fang, Zhi-Yi Chen
The growth of cumulus cells is closely related to the development of the oocyte, and cumulus cell apoptosis affects the maturation, fertilisation, and cleavage of the oocyte and may thus be used to predict IVF outcomes. With the advancement of high-resolution TV-CDS, ultrasound features can be regarded as markers in the evaluation of ovarian response. Moreover, TV-CDS is more likely to detect the cumulus on the day of hCG injection, thus indirectly indicating a good ovarian response, which is correlated with the number of retrieved oocytes, fertilised eggs, and excellent-grade embryos (Jadaon et al. 2012). In this study, we found that the number of cumulus oophorus observed on the day of hCG injection was positively correlated with the number of oocytes and fertilised oocytes. The number of cumulus oophorus gradually increased from the low response group to the normal response group and the high response group, and the number of oocytes retrieved, the number of fertilised oocytes, and the number of high-quality embryos also gradually increased. These results indirectly prove that the cumulus oophorus is a syncytium with complete structure and function, which is closely related to the growth, development, maturation, and fertilisation of oocytes (Tola et al. 2019). According to Bertolin's study, successful fertilisation is related to the quantity and quality of cumulus expansion. The cumulus oophorus creates a beneficial microenvironment for the growth and development of oocytes (Bertolin et al. 2017). The cumulus oophorus is essential for normal oocyte development, ovulation, and fertilisation.
Paraben concentrations found in human body fluids do not exert steroidogenic effects in human granulosa primary cell cultures
Published in Toxicology Mechanisms and Methods, 2020
Elena Herrera-Cogco, Bruno López-Bayghen, Dinorah Hernández-Melchor, Almena López-Luna, Cecilia Palafox-Gómez, Leticia Ramírez-Martínez, Estheisy López-Bello, Arnulfo Albores, Esther López-Bayghen
Cultured mural granulosa cells are a model that can be used to screen for toxic effects of the female reproductive system, an idea that was initially proposed by Hughes and colleagues. In their studies, they demonstrate that human obtained cultured granulosa cells produce progesterone but not estrogen. They also showed that cultured granulosa cells respond to molecules with estrogenic activity, such as 17β-estradiol or clomiphene citrate, inducing a decrease in progesterone production (Hughes et al. 1990). Therefore, we decided to expand upon this idea but taking into consideration the cell’s phenotype. In vivo, granulosa cells exhibit two phenotypes, cumulus and mural. Cultured human granulosa cells are typically obtained from the follicular fluid, and their phenotype, whether cumulus or mural, has not been extensively characterized. By using cells obtained by decumulation, we started with a highly enriched sample of cumulus cells. After seeding these cells, we monitored the expression of critical transcription markers for each phenotype. Here, we show a concomitantly increased expression of CYP11A1 and LHCGR, markers for mural cell phenotype, with decreased expression of PTGS2 and HAS2, markers for the cumulus cells phenotype. These observations, coupled with the observed increase in progesterone production and positive immunostaining for CYP11A1 and LHCGR, support the notion that these cultured cells are mural granulosa cells. To our knowledge, this resulted in having the best-characterized mural primary culture to analyze the differentiation process from cumula to mural granulosa.
Related Knowledge Centers
- Amino Acid Transporter
- Antral Follicle
- Corona Radiata
- Ovarian Follicle
- Ovulation
- Spermatozoon
- Sterol
- Oocyte
- Membrana Granulosa
- Fertilisation