scholarly journals Epiregulin can effectively mature isolated cumulus–oocyte complexes, but fails as a substitute for the hCG/epidermal growth factor stimulus on cultured follicles

Reproduction ◽  
2009 ◽  
Vol 137 (6) ◽  
pp. 997-1005 ◽  
Author(s):  
Sergio Romero ◽  
Johan Smitz

Epiregulin mediates LH ovulatory effectsin vitro. This study evaluated the use of epiregulin as an alternative to hCG/epidermal growth factor (EGF) stimulus upon cultured ovarian follicles in contrast to isolated cumulus–oocyte complexes (COCs). Pre-antral mouse ovarian follicles were cultured for 12 days and final maturation was induced by administration of 0.65 nM EGF or 100 nM epiregulin without or with 1.2 IU/ml hCG. Results showed that both EGF or epiregulin as sole stimulators are poor inducers of mucification/expansion of cumulus cells and oocyte meiotic reinitiation in follicle-enclosed COCs (25±17 and 22±16% GVBD respectively; versus 97±4 and 90±15% GVBD by control hCG/EGF and hCG/epiregulin respectively; mean±s.d). Furthermore, EGF or epiregulin did not induce follicle luteinisation: progesterone production was marginally increased and oestradiol was incompletely shut down. Supposing that the sub-normal progesterone secretion was a potential cause for incomplete meiosis in this model, effectiveness of progesterone supplementation and addition of a progesterone receptor inhibitor (RU486) were evaluated on meiotic resumption. Progesterone was not found to be a major regulator of meiosis in this mouse model. Epiregulin induced meiosis more effectively in COCs isolated from cultured preovulatory follicles in a secondary culture well. In conclusion, epiregulin has similar effects as EGF upon fully grown follicles. Used as a sole stimulator of periovulatory events in intact cultured follicles, both are poor inducers of follicle luteinisation and oocyte maturation. By contrast, epiregulin is as efficient as hCG/EGF, when used as meiotic stimulator for COCs isolated from the follicular environment (mural granulosa and theca cells; and conditioned medium).

Reproduction ◽  
2005 ◽  
Vol 130 (4) ◽  
pp. 517-528 ◽  
Author(s):  
Zhong Zhao ◽  
Damien Garbett ◽  
Julia L Hill ◽  
David J Gross

Cumulus cell–oocyte complexes (COCs), culturedin vitro, are competent for maturation and fertilization. Inclusion of epidermal growth factor (EGF) in the COC culture medium enhancesin vitromaturation and subsequent embryonic development. It has been shown that isolated COCs exposed to EGF respond with a prolonged and pulsatile release of Ca2+into the extra-cellular medium and that cumulus cells (CCs) of complexes exhibit both a slow rise in intracellular [Ca2+] ([Ca2+]i) and plasma membrane permeabilization in response to EGF. These unusual signaling responses were examined in isolated, cultured bovine CCs. Few individual CCs showed [Ca2+]iincreases; the lack of response was found to be due to decrease of expression of endogenous EGF receptors after dissociation. CCs transfected with a human EGF receptor–GFP fusion protein showed robust, prolonged, EGF-stimulated [Ca2+]ielevations characteristic of CC responses in intact COCs. Many CCs that responded to EGF stimulation with a [Ca2+]irise also released entrapped fura-2 dye at the peak of the [Ca2+]iresponse, suggesting that CC permeabilization and death follows activation of the EGF receptor. The [Ca2+]ielevation due to EGF stimulation and subsequent membrane permeabilization was shown to be mediated by the inositol triphosphate signaling pathway.


Reproduction ◽  
2011 ◽  
Vol 141 (4) ◽  
pp. 425-435 ◽  
Author(s):  
Radek Procházka ◽  
Michal Petlach ◽  
Eva Nagyová ◽  
Lucie Němcová

The aim of this work was to assess the FSH-stimulated expression of epidermal growth factor (EGF)-like peptides in cultured cumulus–oocyte complexes (COCs) and to find out the effect of the peptides on cumulus expansion, oocyte maturation, and acquisition of developmental competencein vitro. FSH promptly stimulated expression of amphiregulin (AREG) and epiregulin (EREG), but not betacellulin (BTC) in the cultured COCs. Expression ofAREGandEREGreached maximum at 2 or 4 h after FSH addition respectively. FSH also significantly stimulated expression of expansion-related genes (PTGS2,TNFAIP6, andHAS2) in the COCs at 4 and 8 h of culture, with a significant decrease at 20 h of culture. Both AREG and EREG also increased expression of the expansion-related genes; however, the relative abundance of mRNA for each gene was much lower than in the FSH-stimulated COCs. In contrast to FSH, AREG and EREG neither stimulated expression ofCYP11A1in the COCs nor an increase in progesterone production by cumulus cells. AREG and EREG stimulated maturation of oocytes and expansion of cumulus cells, although the percentage of oocytes that had reached metaphase II was significantly lower when compared to FSH-induced maturation. Nevertheless, significantly more oocytes stimulated with AREG and/or EREG developed to blastocyst stage after parthenogenetic activation when compared to oocytes stimulated with FSH alone or combinations of FSH/LH or pregnant mares serum gonadotrophin/human chorionic gonadotrophin. We conclude that EGF-like peptides do not mimic all effects of FSH on the cultured COCs; nevertheless, they yield oocytes with superior developmental competence.


2011 ◽  
Vol 23 (1) ◽  
pp. 222
Author(s):  
E. S. Caixeta ◽  
M. F. Machado ◽  
P. Ripamonte ◽  
P. F. Lima ◽  
A. C. S. Castilho ◽  
...  

Epidermal growth factor (EGF)-like family members [amphiregulin (AREG), epiregulin (EREG), and betacellulin (BTC)] have been shown to be important regulators of cumulus–oocyte complex (COC) maturation, particularly cumulus expansion. The aim of this study was to determine the temporal expression patterns of mRNA encoding EGF-like growth factors in bovine cumulus cells (CC) during COC in vitro maturation and to assess the effects of grading doses of FSH on EGF-like mRNA expression in CC. Immature COC (grades 1 and 2) were obtained from 2- to 8-mm follicles from abattoir ovaries. In the first experiment, CC were separated from 20 COC and frozen before (immature group) or after COC culture for 4, 8, 12, 16, and 20 h with (10 ng mL–1) or without FSH. In the second experiment, pools containing 20 COC were matured for 12 h with grading doses of FSH (0, 0.1, 1, 10, and 100 ng mL–1). After culture, CC were mechanically separated and stored at –80°C. Total RNA was extracted using RNeasy® (Qiagen, Valencia, CA, USA), and 100 ng of RNA was reverse transcribed. Expression of target genes was assessed by real-time PCR and normalized by Cyclophilin (CYC-A). Relative quantification of mRNA abundance was determined by the Pfaffl equation. Effects of time of culture and FSH treatment were tested by ANOVA, and groups were compared by Tukey-Kramer honestly significant difference test. Nonparametric analysis was used when data were not normally distributed. Differences were considered significant when P < 0.05. In the presence of FSH, AREG and EREG mRNA abundance was increased at 4 h of culture, whereas in the absence of FSH, AREG but not EREG mRNA levels were increased by 4 h of culture. The addition of FSH stimulated AREG mRNA expression from 4 to 16 h of culture. In contrast, BTC mRNA was more expressed in immature CC, decreased after 4 h of culture with FSH, and did not vary during maturation in the absence of FSH. In the dose–response experiment, AREG and EREG mRNA expression was stimulated by FSH starting from 10 ng mL–1 and did not increase from 10 ng mL–1 to 100 ng mL–1. Again in contrast, BTC mRNA expression was inhibited by FSH at 100 ng mL–1. In conclusion, the present data suggest that FSH differently regulates the expression of EGF-like factors during bovine COC maturation, although AREG and EREG are stimulated, BTC is inhibited by FSH. This work was supported by FAPESP.


1998 ◽  
Vol 13 (6) ◽  
pp. 1638-1644 ◽  
Author(s):  
P. T. Goud ◽  
A. P. Goud ◽  
C. Qian ◽  
H. Laverge ◽  
J. Van der Elst ◽  
...  

2020 ◽  
Vol 20 (18) ◽  
pp. 1628-1639
Author(s):  
Sergi Gómez-Ganau ◽  
Josefa Castillo ◽  
Andrés Cervantes ◽  
Jesus Vicente de Julián-Ortiz ◽  
Rafael Gozalbes

Background: The Epidermal Growth Factor Receptor (EGFR) is a transmembrane protein that acts as a receptor of extracellular protein ligands of the epidermal growth factor (EGF/ErbB) family. It has been shown that EGFR is overexpressed by many tumours and correlates with poor prognosis. Therefore, EGFR can be considered as a very interesting therapeutic target for the treatment of a large variety of cancers such as lung, ovarian, endometrial, gastric, bladder and breast cancers, cervical adenocarcinoma, malignant melanoma and glioblastoma. Methods: We have followed a structure-based virtual screening (SBVS) procedure with a library composed of several commercial collections of chemicals (615,462 compounds in total) and the 3D structure of EGFR obtained from the Protein Data Bank (PDB code: 1M17). The docking results from this campaign were then ranked according to the theoretical binding affinity of these molecules to EGFR, and compared with the binding affinity of erlotinib, a well-known EGFR inhibitor. A total of 23 top-rated commercial compounds displaying potential binding affinities similar or even better than erlotinib were selected for experimental evaluation. In vitro assays in different cell lines were performed. A preliminary test was carried out with a simple and standard quick cell proliferation assay kit, and six compounds showed significant activity when compared to positive control. Then, viability and cell proliferation of these compounds were further tested using a protocol based on propidium iodide (PI) and flow cytometry in HCT116, Caco-2 and H358 cell lines. Results: The whole six compounds displayed good effects when compared with erlotinib at 30 μM. When reducing the concentration to 10μM, the activity of the 6 compounds depends on the cell line used: the six compounds showed inhibitory activity with HCT116, two compounds showed inhibition with Caco-2, and three compounds showed inhibitory effects with H358. At 2 μM, one compound showed inhibiting effects close to those from erlotinib. Conclusion: Therefore, these compounds could be considered as potential primary hits, acting as promising starting points to expand the therapeutic options against a wide range of cancers.


Author(s):  
Nuria Hernández ◽  
Marta López-Morató ◽  
Mario J Perianes ◽  
Soledad Sánchez-Mateos ◽  
Vanessa Casas-Rua ◽  
...  

Abstract Embryo implantation in the uterus is a critical step to achieve success following ART. Despite favorable uterine conditions, a great number of good quality embryos fail to implant, often for reasons that are unknown. Hence, improving the implantation potential of embryos is a subject of great interest. 4-Hydroxyestradiol (4-OH-E2), a metabolic product of estradiol produced by endometrial cells, plays a key role in endometrial–embryonic interactions that are necessary for implantation. Nonetheless, the effects of 4-OH-E2 on embryos obtained in vitro have not been yet described. This study was designed to determine whether culture media enriched in 4-OH-E2 could improve the quality and implantation rate of embryos obtained in vitro, using both in vitro and in vivo models. We also analyzed its effects on the epidermal growth factor (EGF)-binding capability of the embryos. Our results showed that the presence of 4-OH-E2 in the culture media of embryos during the morula to blastocyst transition increases embryo quality and attachment to endometrial cells in vitro. 4-OH-E2 can also improve viable pregnancy rates of mouse embryos produced in vitro, reaching success rates that are similar to those from embryos obtained directly from the uterus. 4-OH-E2 improved the embryos’ ability to bind EGF, which could be responsible for the increased embryo implantation potential observed. Therefore, our results strongly suggest that 4-OH-E2 is a strong candidate molecule to supplement human IVF culture media in order to improve embryo implantation. However, further research is required before these findings can be translated with efficacy and safety to fertility clinics.


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