262 ISOBUTYLMETHYLXANTHINE REVERSIBLY SUPPRESSES SPONTANEOUS AND EQUINE CHORIONIC GONADOTROPIN/EPIDERMAL GROWTH FACTOR-STIMULATED MEIOSIS IN FELINE OOCYTES

2011 ◽  
Vol 23 (1) ◽  
pp. 229
Author(s):  
J. R. Herrick

Recent studies have shown that short-term exposure to phosphodiesterase inhibitors (decreased cAMP degradation) or adenylate cyclase stimulators (increased cAMP synthesis) inhibits spontaneous oocyte maturation and improves the developmental competence of oocytes after gonadotropin-induced maturation. A similar approach may improve the developmental competence of in vitro matured feline oocytes. The objectives of this study were to 1) determine if a nonspecific phosphodiesterase inhibitor [isobutylmethylxanthine (IBMX); 100 μM] or an adenylate cyclase stimulator (forskolin; 100 μM) would suppress spontaneous or eCG (1 IU mL–1)/epidermal growth factor (EGF; 25 ng mL–1)-induced maturation of feline oocytes in vitro; 2) evaluate the reversibility of chemically induced meiotic arrest; and 3) assess the developmental competence of meiotically arrested oocytes. Cumulus–oocyte complexes were cultured in modified feline optimized culture medium [6 mM glucose, 0.1 mM cysteamine, 0.6 mM cysteine, 0.5× minimal essential medium (MEM) essential amino acids, 1× MEM vitamins, and 1× insulin-transferrin-selenium; Herrick et al. 2010 Biol. Reprod. 82, 552–562] supplemented with (+) or without (–) IBMX, forskolin, or eCG/EGF (eE). The IBMX decreased (P < 0.05; mixed model ANOVA) the incidence of spontaneous maturation (–eE) after 24 h of culture (84.6%, germinal vesicle, GV; 6.7% metaphase II, MII) compared with control (no supplements) oocytes (18.8% GV, 42.0% MII). Forskolin (–eE) stimulated (P < 0.05) meiosis (6.1% GV, 81.7% MII), so it was not tested in subsequent experiments. The IBMX also inhibited (P < 0.05) eE-induced meiosis compared with control (–IBMX +eE) oocytes after 18 h (87.6 v. 27.1% GV, 2.5 v. 11.0% MII), 24 h (68.0 v. 11.9% GV, 5.6 v. 66.1% MII), and 30 h (58.1 v. 9.4% GV, 14.6 v. 64.4% MII) of culture. To evaluate the reversibility of IBMX, oocytes were cultured +IBMX –eE for 12 h and then transferred to medium –IBMX +eE. After 12 h of culture –IBMX +eE (24 h total), fewer (P < 0.05) IBMX-exposed oocytes were MII (6.6%) compared with control oocytes cultured for 24 h +eE –IBMX (70.2%). The proportion of IBMX-exposed oocytes reaching MII increased (P < 0.05) following 18 h of culture –IBMX +eE (30 h total; 49.4% MII), and by 24 h of culture –IBMX +eE (36 h total; 66.1% MII) was similar (P > 0.05) to the proportion of MII oocytes (78.3%) that had been cultured continuously for 36 h –IBMX +eE. Finally, oocytes were cultured for 0 h or 12 h +IBMX –eE followed by 24 h of culture –IBMX +eE, coincubated with frozen–thawed spermatozoa (5 × 105 sperm mL–1, 22 h), and the resulting embryos cultured (6% CO2, 5% O2) until day 7 post-insemination (Herrick et al. 2007 Biol. Reprod. 76, 858–870). The proportion of oocytes cleaving (83.0 v. 79.9%) and the proportions of oocytes (20.8 v. 18.7%) or embryos (25.2 v. 23.6%) developing to the blastocyst stage were not affected (P > 0.05) by 12 h of IBMX exposure during oocyte maturation. These results demonstrate that IBMX reversibly inhibits both spontaneous and eCG/EGF-induced meiosis in feline oocytes without compromising the oocyte’s developmental competence. This work was supported by the College of Veterinary Medicine’s Companion Animal Memorial Fund at the University of Illinois.

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.


Zygote ◽  
2015 ◽  
Vol 24 (3) ◽  
pp. 465-476 ◽  
Author(s):  
Mehdi Vafaye Valleh ◽  
Mikkel Aabech Rasmussen ◽  
Poul Hyttel

SummaryThe developmental potential of in vitro matured porcine oocytes is still lower than that of oocytes matured and fertilized in vivo. Major problems that account for the lower efficiency of in vitro production include the improper nuclear and cytoplasmic maturation of oocytes. With the aim of improving this issue, the single and combined effects of epidermal growth factor (EGF) and glial cell line-derived neurotrophic factor (GDNF) on oocyte developmental competence were investigated. Porcine cumulus–oocyte cell complexes (COCs) were matured in serum-free medium supplemented with EGF (0, 10 or 50 ng/ml) and/or GDNF (0, 10 or 50 ng/ml) for 44 h, and subsequently subjected to fertilization and cultured for 7 days in vitro. The in vitro-formed blastocysts derived from selected growth factor groups (i.e. EGF = 50 ng/ml; GDNF = 50 ng/ml; EGF = 50 ng/ml + GDNF = 50 ng/ml) were also used for mRNA expression analysis, or were subjected to Hoechst staining. The results showed that the addition of EGF and/or GDNF during oocyte maturation dose dependently enhanced oocyte developmental competence. Compared with the embryos obtained from control or single growth factor-treated oocytes, treatment with the combination of EGF and GDNF was shown to significantly improve oocyte competence in terms of blastocyst formation, blastocyst cell number and blastocyst hatching rate (P < 0.05), and also simultaneously induced the expression of BCL-xL and TERT and suppressed the expression of caspase-3 in resulting blastocysts (P < 0.05). These results suggest that both GDNF and EGF may play an important role in the regulation of porcine in vitro oocyte maturation and the combination of these growth factors could promote oocyte competency and blastocyst quality.


2008 ◽  
Vol 20 (1) ◽  
pp. 182 ◽  
Author(s):  
Y. Locatelli ◽  
N. Poulin ◽  
G. Baril ◽  
J.-L. Touzé ◽  
A. Fatet ◽  
...  

The aim of the present study was to assess the effect of IVM treatment on the developmental competence of oocytes recovered from repeated laparoscopic ovum pickukp (LOPU) in goats. A total of 94 LOPU sessions were performed on 33 adult goats of the Saanen and Alpine breeds. Females were synchronized (Day 0) during the nonbreeding season by inserting vaginal sponges (45 mg of fluorogestone acetate, Intervet, Boxmeer, The Netherlands). At Day 8, an i.m. injection of 50 μg of cloprostenol (Estrumate; Schering-Plough Animal Health, Pointe-Claire, Quebec, Canada) was administered. Porcine FSH (Stimufol, Merial, Brussels, Belgium, 160 mg/goat) was administered in 5 injections at 12-h intervals, starting on Day 8. The LOPU took place under general anesthesia on Day 11, and follicles ≥2 mm were aspirated with an 18-gauge needle connected to a controlled vacuum system. Vaginal sponges were removed at the time of LOPU. Treatments were repeated 2 times in a 2-week interval scheme (2 goats and 1 goat were excluded from the experiment during the second and third LOPU sessions, respectively). Cumulus–oocyte complexes were washed and evaluated for quality (graded from 1 to 3). Oocytes recovered from unstimulated slaughterhouse-derived ovaries served as a control. Cumulus–oocytes complexes from Grades 1 and 2 were submitted to IVM in TCM-199, supplemented with 100 μm of cysteamine and either 10 ng mL–1 of epidermal growth factor (EGF) or 10% follicular fluid and 100 ng mL–1 of ovine FSH (FF-FSH). Matured oocytes were then submitted to IVF and in vitro development as described by Cognié et al. (2004 Reprod. Fertil. Dev. 16, 437–445). Over the 94 LOPU sessions, 20.4 ± 0.9 follicles were aspirated (mean ± SEM), allowing the recovery of 12.3 ± 0.7 COC per goat and per session, of which 80.1% were suitable for IVM (Grades 1 and 2). Results of in vitro production are detailed in the table. The IVM treatment did not significantly affect cleavage or blastocyst development rates in oocytes derived from slaughterhouse ovaries. Cleavage rates were significantly decreased in LOPU-derived oocytes when compared with control oocytes. For LOPU-derived oocytes, cleavage and final blastocyst development rates were increased significantly and kinetics of embryo development were accelerated when FF-FSH was used during IVM as compared with EGF. The IVM with FF-FSH allowed us to produce 4.1 blatocysts per goat per LOPU session. These results demonstrate the interest in LOPU for goat embryo production once appropriate IVM treatment is used. The difference observed between LOPU and slaughterhouse oocytes in terms of response to IVM treatments may be related to FSH stimulation prior to the LOPU session or to postmortem changes in oocyte responsiveness in the slaughterhouse group. Table 1. Effects of oocyte origin [laparoscopic ovum pickukp (LOPU) or slaughterhouse derived] and maturation treatment [epidermal growth factor (EGF) or follicular fluid (FF)-FSH] on in vitro embryo production (6 replicates)


2017 ◽  
Vol 29 (1) ◽  
pp. 180
Author(s):  
T. Yamanouchi ◽  
S. Sugimura ◽  
H. Matsuda ◽  
M. Ohtake ◽  
Y. Goto ◽  
...  

Bovine oocytes obtained by ovum-pick-up (OPU) following follicle growth treatment (FGT) have improved quality and competence (Imai et al. 2008 Reprod. Fertil. Dev. 20, 182). However, the effect of the presence of FSH or epidermal growth factor (EGF) like peptide during in vitro maturation (IVM) on the developmental competence of FGT oocytes has not been well known. This study was undertaken to examine the developmental competence of FGT oocytes following IVM in the presence of FSH (recombinant human FSH) or EGF-like peptide (amphiregulin; Areg) and IVF. Japanese Black cows (n = 17) were used as donors. Five days after arbitrary OPU (opu group), follicles ≥8 mm in diameter were aspirated again, a controlled internal drug release (CIDR) was inserted into the vagina, and then pFSH was injected twice a day from the evening of Day 6 to the morning of Day 10 with decreasing doses (total of 20 AU; 4, 4, 3, 3, 2, 2, 1, 1 AU/day). On the evening of Day 8, PGF2α (0.5 mg of cloprostenol) was administered. On Day 11, oocytes were aspirated from follicles with ≥5 mm in diameter of the treated donors by OPU (fgt group). The cumulus-oocyte complexes (COC) were cultured in the absence (opu-cont and fgt-cont groups) or presence of 0.1 IU mL−1 FSH (opu-fsh and fgt-fsh groups) or 100 ng mL−1 Areg (opu-areg and fgt-areg groups) in IVM medium (mTCM199 containing 5 mg mL−1 BSA) for 20 to 22 h (1 COC/5 µL, total of 162–171 COC per group), and then co-cultured with 3 × 106 sperm/mL for 6 h. The presumptive zygotes were continued to culture in mCR1aa supplemented with 5% newborn calf serum for 216 h (1 zygote/5 µL) using micro-well culture dishes (Dai-Nippon-Print). When repeating this opu-fgt session in the same cow, an interval at least for 50 days was kept, and the session was performed 28 times. Statistical analysis was carried out by Mann-Whitney’s U-test (between opu and fgt groups) or Steel-Dwass test after Kruskal-Wallis test (among all groups). The number of follicles ≥5 mm increased in the fgt than opu group (17.8 v. 2.9; P < 0.01). The number of COC collected was not different between the opu and fgt groups (23.1 v. 19.6; P > 0.05). The blastocyst formation rate was higher in the fgt than opu group (36.9 v. 23.1%; P < 0.01). Within 6 groups, the blastocyst formation rate was higher in the fgt-fsh (43.3%; P < 0.01) and fgt-areg (39.5%; P < 0.05) groups than the opu-cont (16.3%) group. The rate in the fgt-fsh group was also higher than that in the opu-fsh group (43.3 v. 18.7%; P < 0.01). These results suggested that FGT improved the developmental competence of bovine oocytes, probably through improving the ability of the COC to react against FSH/Areg.


Endocrinology ◽  
2005 ◽  
Vol 146 (1) ◽  
pp. 77-84 ◽  
Author(s):  
H. Ashkenazi ◽  
X. Cao ◽  
S. Motola ◽  
M. Popliker ◽  
M. Conti ◽  
...  

Previous studies showed that epidermal growth factor (EGF) and TGFα mimic the action of LH on the resumption of oocyte maturation. We tested whether EGF-like agents, such as amphiregulin (AR), epiregulin (ER), and betacellulin (BTC), also mediate the LH stimulation of the ovulatory response in the rat. LH induced transient follicular expression of AR, ER, and BTC mRNA, reaching a maximum after 3-h incubation. Furthermore, the addition of ER, AR, and BTC to the culture medium could mimic some of LH actions. AR and ER fully simulated LH-induced resumption of meiosis in vitro, whereas BTC was less effective. To study the putative involvement of EGF-like factors in mediation of LH signal, the effect of the EGF receptor kinase inhibitor AG1478 was tested. When added with LH, AG1478, but not its inactive analog AG43, reduced EGF receptor phosphorylation and oocyte maturation compared with follicles treated with LH only. In addition to the inhibition of resumption of meiosis, AG1478 administration into the bursa (3 μg/bursa) resulted in 51% (P &lt; 0.0005) inhibition of ovulation in the treated ovaries, compared with the untreated contralateral ones, as well as to the vehicle-treated ovaries (P &lt; 0.02). LH, as well as ER, induced the expression of genes associated with the ovulatory response like rat hyaluronan synthase-2, cycloxygenase-2, and TNFα-stimulated gene 6 mRNA, whereas AG1478 inhibited this effect of LH. Release of EGF-like factors from the membrane is dependent on activated metalloproteases. Indeed, Galardin, a broad-spectrum metalloprotease inhibitor, but not a specific matrix metalloprotease 2 and 9 inhibitor, suppressed meiotic maturation induced by LH. Conversely, meiotic maturation induced by ER was not affected by Galardin, thus, supporting the notion that LH releases follicular membrane-bound EGF-like agents. In summary, EGF-like factors such as ER, AR, and BTC seem to mediate, at least partially, the LH stimulation of oocyte maturation, ovulatory enzyme expression, and ovulation.


Zygote ◽  
2016 ◽  
Vol 25 (2) ◽  
pp. 120-130 ◽  
Author(s):  
Marta Wasielak ◽  
Teresa Więsak ◽  
Iwona Bogacka ◽  
Beenu Moza Jalali ◽  
Marek Bogacki

SummaryMaternal effect genes (MEG) play a crucial role in early embryogenesis. In vitro culture conditions may affect MEG expression in porcine oocytes and embryos. We investigated whether in vitro culture medium supplementation with epidermal growth factor (EGF), IL-1β or LIF (leukemia inhibitory factor) affects the mRNA level of ZAR-1 (zygote arrest 1), NPM2 (nucleoplasmin 2) and DPPA3 (developmental associated protein 3) in porcine MII oocytes and embryos. Cumulus–oocyte complexes (COCs) were matured in NCSU-37 medium (control) or in NCSU-37 with EGF 10 ng/ml, IL-1β 10 ng/ml or LIF 50 ng/ml. After maturation for 44–46 h, MII oocytes were preserved for the analysis of MEG mRNA levels (experiment 1). In experiment 2, COCs were fertilized, and the presumptive zygotes were cultured in the same groups. Then, 2-, 4-, 8-cell embryos, morulae and blastocysts were collected for the analysis of MEG mRNA levels. LIF addition to the maturation medium increased MII oocyte numbers (P < 0.05), while EGF and IL-1β did not affect oocyte maturation. Medium supplementation with EGF resulted in lower DPPA3 mRNA levels in MII oocytes and in 2- and 4-cell embryos versus control embryos (P < 0.05). LIF treatment increased DPPA3 mRNA levels in morulae and blastocysts (P < 0.05). Culture with EGF and IL-1β decreased ZAR-1 and NPM2 mRNA levels in 2-cell embryos (P < 0.05). The inclusion of EGF or IL-1β in the porcine in vitro production system influences ZAR-1, NPM2 and DPPA3 mRNA in MII oocytes and embryos but not beyond the 4-cell stage. LIF stimulates oocyte maturation and affects DPPA3 mRNA in porcine morulae and blastocysts in vitro.


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