60 EFFECTS OF AY9944 A-7 ON MEIOTIC RESUMPTION OF PORCINE OOCYTES AND CUMULUS CELL EXPANSION

2016 ◽  
Vol 28 (2) ◽  
pp. 160
Author(s):  
S. Lee ◽  
C. Khoirinaya ◽  
J.-X. Jin ◽  
G. A. Kim ◽  
B.-C. Lee

In vitro studies on mammalian oocytes have shown that follicular fluid-meiosis activating sterol (FF-MAS) can overcome the inhibitory effect of hypoxanthine (Hx) on the resumption of meiosis. FF-MAS, an intermediate in the cholesterol biosynthesis pathway, is converted to testis meiosis–activating sterol by a sterol Δ14-reductase. AY9944 A-7, an inhibitor of Δ14-reductase and Δ7-reductase, induces accumulation of FF-MAS by inhibiting its metabolism. The aim of this study was to evaluate the effects of AY9944 A-7 on meiotic resumption of porcine oocytes, cumulus cell expansion, and gene expression related to M-phase-promoting factor (MPF), mitogen-activated protein kinase (MAPK), and oocyte maturation in oocytes and related to cumulus expansion in cumulus cells. In experiment 1, 1136 cumulus-oocyte complexes (COCs) were cultured in IVM media with 4 different concentrations (0, 10, 20, and 40 μM) of AY9944 A-7 in addition to a meiotic inhibitor (Hx, 4 mM) for 44 h. Oocytes treated with 10 and 20 μM AY9944 A-7 in the presence of Hx had significantly higher GVBD and M2 rates than the control group. However, 40 μM AY9944 A-7 significantly decreased GVBD and M2 rates and increased degeneration of oocytes compared with other groups. In experiment 2, 600 COCs were cultured in IVM media with 4 different concentrations (0, 10, 20, and 40 μM) of AY9944 A-7 in the absence of Hx for 44 h. Cumulus expansion of 40 μM AY9944 A-7 treated group was significantly decreased compared with other groups. In experiment 3, we evaluate the effects of AY9944 A-7 on gene expression, and the experiment was replicated four times. Data on gene expression were analysed using Student’s t-test. Oocytes treated with 10 μM AY9944 A-7 increased expression of genes involved in MPF (Cyclin B and Cdc2), MAPK (C-mos), and oocyte maturation (GDF9 and BMP15). Cumulus cells treated with 10 μM AY9944 A-7 decreased cumulus expansion-related genes (Has2, Tnfaip6, Ptgs2, and Ptx-3). In conclusion, our results suggest that although 10 μM AY9944 A-7 decreased cumulus expansion-related genes, there was no difference in cumulus expansion and it induced meiotic resumption of porcine oocytes with increased MPF, MAPK, and oocyte maturation-related genes. Further studies are needed to evaluate the effect of AY9944 A-7 on porcine embryo development. This study was supported by Ministry Of Trade, Industry & Energy (#10048948), Korea IPET (#114059–3), Research Institute for Veterinary Science, TS Corporation, and the BK21 plus program.


2010 ◽  
Vol 22 (1) ◽  
pp. 322
Author(s):  
D. D. Bücher ◽  
M. A. Castro ◽  
M. E. Silva ◽  
M. A. Berland ◽  
I. I. Concha ◽  
...  

Granulocyte-macrophage colony stimulating factor (GM-CSF) is a pleiotropic cytokine that stimulates proliferation, differentiation and function in different cells types. We have previously demonstrated (Bücher DD et al. 2008 Reprod. Dom. Anim. 43 (Suppl. 3), 146 abst.) that both subunits of GM-CSF receptor are expressed in granulosa cells from antral follicles in bovine ovaries. Also, we determined that the cytokine enhances glucose uptake through facilitative hexose transporters in granulosa cells in primary culture. The goals of the present study were to characterize the expression of GM-CSF receptor in cumulus cells and oocytes from bovine antral follicles and to determine its effects on in vitro-matured bovine COCs in a chemically defined medium. To determine the presence of a and |5 subunits of GM-CSF receptor, COCs were aspirated from follicles <8 mm in diameter, fixed, and submitted to immunocytochemistry. To study the effect of GM-CSF on in vitro maturation of oocytes, COCs (n =481) were cultured using serum-free medium (SOF) containing 0, 1, 10, and 100 ng mL-1 of human recombinant GM-CSF (R&D Systems, Inc., Minneapolis, MN, USA) for 22 h at 39°C, 5% CO2 in humidified air. Nuclear stage, cumulus expansion, cumulus cell number, and viability were analyzed after in vitro maturation. Cumulus expansion was assessed using the cumulus expansion index (CEI) (Fagbohun C and Down S 1990 Biol. Reprod. 42, 413-423). Nuclear stage was evaluated using aceto-orcein stain. To determine cumulus cell viability and number, COCs (n = 10-12 per group) were transferred into an Eppendorf tube and cumulus cells were removed by vortexing for 3 min, stained with trypan blue and counted with a hemocytometer. The study was conducted in 6 replicates. Data from cumulus expansion and cell number were analyzed by Kruskal-Wallis analysis. Data for nuclear stage and cell viability were analyzed by chi-square analysis and one way ANOVA, respectively. Both receptor subunits were present in cumulus cells and oocytes from COCs. COCs cultured in 10 and 100 ng mL-1 GM-CSF had CEI scores (0.8 and 1.22, respectively) greater (P < 0.01) than controls (0.2), but the proportion of COCs displaying second metaphase did not differ (P = 0.5) among treatment groups. GM-CSF at a concentration of 100 ng mL-1 increased (P < 0.01) cumulus cell viability by more than 20% compared to the control group. Similarly, GM-CSF at concentrations of 10 and 100 ng mL-1 increased (P < 0.05) cumulus cell number by more than 20% and 45%, respectively, from the control group. The use of a specific inhibitor of PI3 kinase (Ly294002; 10 and 100 μM) blocked the stimulatory effect of GM-CSF on cumulus expansion, cell viability, and cell number. In conclusion, the results of the study suggest a plausible modulator role of GM-CSF in the metabolism and function of cumulus cells and oocytes during in vitro maturation. Funding from Faculty of Veterinary Sciences, Universidad Austral de Chile, MECESUP AUS-0005, AUS-0601, and DID D-2006-24 and from Universidad Católica de Temuco, research grant 2007 DGI-CDA-04.



2017 ◽  
Vol 29 (1) ◽  
pp. 199
Author(s):  
A. W. Harl ◽  
E. L. Larimore ◽  
A. Al Naib ◽  
L. K. Wooldridge ◽  
A. D. Ealy ◽  
...  

The objective of this work was to determine how characteristics of bovine follicle fluid (FF; especially oestradiol content) affect cumulus cell expansion and oocyte competence. In the first study, FF was collected from abattoir-derived ovaries and pooled separately for large follicles (≥10 mm) and small follicles (≤3 mm). A portion of the FF from each category was charcoal stripped. These 4 types of FF were then used as the primary ingredient (75% vol/vol) in oocyte maturation media. A separate control group lacking FF but containing BSA was included to monitor potential impacts of protein on outcomes (control; without FF). Some of the cumulus-oocyte complexes (COC; n = 250) were matured in individual drops for analysis of cumulus expansion (photographed and measured at 0 and 21 h of maturation). Other COC (n = 770) were matured in groups of 12 to 25 in the previously described media, and then subjected to IVF procedures. Cleavage rates were recorded on Day 3, and blastocyst rates were recorded on Day 8 post-fertilization. Cumulus cell expansion was greatest when COC were matured in medium containing FF from large follicles, wherein it even exceeded the controls (P < 0.02). Maturation in FF from small follicles resulted in cumulus expansion that was intermediate between large and control. Maturation in charcoal-stripped FF severely restricted cumulus cell expansion (P < 0.05) compared with those matured in untreated FF. Despite the observed improvement in cumulus cell expansion, COC that had been matured in media containing FF were less likely to cleave (P < 0.05) and also less likely to develop to the blastocyst stage (P < 0.01) than those matured in control medium. Cleavage and blastocyst rates did not differ among any of the maturation media containing FF. In the second study, oestrous cycles of 9 crossbred cows were synchronized and FF samples were collected 36 to 42 h after prostaglandin F2α injection. Samples from individual cows were categorized as having high oestradiol (>800,000 pg mL−1; H) or low oestradiol concentrations (<800,000 pg mL−1; L). The FF was retained for use in in vitro experiments, where it was added to maturation media (20% vol/vol). Cumulus-oocyte complexes (n = 1,775) were randomly distributed into treatments across 12 in vitro maturation/fertilization replicates (H and L, balanced within replicate; 4 replicates/cow). Each replicate included the following 3 control groups: maturation medium containing BSA without FF, maturation medium without BSA with abattoir-derived FF, and maturation medium without BSA and without FF. The COC were matured in their assigned medium for 21 h, and then all COC were subjected to IVF procedures. Cleavage rates were recorded on Day 3, and blastocyst rates were recorded on Day 7 and 8 post-fertilization. Oestradiol content of the FF (H v. L) did not affect oocyte cleavage nor blastocyst rates on Day 7 or 8. The results of these studies indicate that although FF improves cumulus cell expansion during maturation in vitro, it does not result in higher rates of cleavage or blastocyst development regardless of oestradiol content.



2015 ◽  
Vol 308 (6) ◽  
pp. E525-E534 ◽  
Author(s):  
Bo Pan ◽  
Derek Toms ◽  
Wei Shen ◽  
Julang Li

We sought to investigate whether miR-378 plays a role in cumulus cells and whether the manipulation of miRNA levels in cumulus cells influences oocyte maturation in vitro. Cumulus-oocyte complexes (COCs) from ovarian follicles had significantly lower levels of precursor and mature miR-378 in cumulus cells surrounding metaphase II (MII) oocytes than cumulus cells surrounding germinal vesicle (GV) oocytes, suggesting a possible role of miR-378 during COC maturation. Overexpression of miR-378 in cumulus cells impaired expansion and decreased expression of genes associated with expansion ( HAS2, PTGS2) and oocyte maturation ( CX43, ADAMTS1, PGR). Cumulus cell expression of miR-378 also suppressed oocyte progression from the GV to MII stage (from 54 ± 2.7 to 31 ± 5.1%), accompanied by a decrease of growth differentiation factor 9 ( GDF9), bone morphogenetic protein 15 ( BMP15), zona pellucida 3 ( ZP3), and CX37 in the oocytes. Subsequent in vitro fertilization resulted in fewer oocytes from COCs overexpressing miR-378 reaching the blastocyst stage (7.3 ± 0.7 vs. 16.6 ± 0.5%). miR-378 knockdown led to increased cumulus expansion and oocyte progression to MII, confirming a specific effect of miR-378 in suppressing COC maturation. Aromatase (CYP19A1) expression in cumulus cells was also inhibited by miR-378, leading to a significant decrease in estradiol production. The addition of estradiol to IVM culture medium reversed the effect of miR-378 on cumulus expansion and oocyte meiotic progression, suggesting that decreased estradiol production via suppression of aromatase may be one of the mechanisms by which miR-378 regulates the maturation of COCs. Our data suggest that miR-378 alters gene expression and function in cumulus cells and influences oocyte maturation, possibly via oocyte-cumulus interaction and paracrine regulation.



2005 ◽  
Vol 17 (2) ◽  
pp. 298 ◽  
Author(s):  
M.M. Petersen ◽  
B. Avery ◽  
T. Greve ◽  
I.B. Bøgh

Development of two-photon laser scanning microscopy (TPLSM) has made it possible to conduct several recordings over time of early stage embryos without compromising viability. To use TPLSM to study structures within the oocyte it is necessary to remove at least part of the cumulus cells to prevent emitted light from being blocked. Aspiration of cumulus oocyte complexes (COC) through a denudation pipette creates a “window” through which the emitted light can escape and be recorded. To allow repeated recordings of the same location within an object it is important to avoid movement of the object. Gelatine (Gel) and poly-l-lysine (PLL) have previously been used to promote adhesion of cells in culture. The aim of our study was to develop a method to avoid movement during IVM of partially denuded COCs without compromising oocyte viability. Previous experiments in our lab showed that partial denudation of COC had no effect on embryo development (unpublished). Bovine COCs were obtained from abattoir ovaries. In the control group COCs were placed in non-treated dishes. In the experimental groups, they were placed in Gel- or PLL-coated dishes, either intact or partially denuded, where the length of cumulus cell “tails” was shortened to around 200 μm on each side of the oocyte. The coated dishes were prepared 24 h prior to IVM with 200 μL of 0.1% Gel (Sigma, Copenhagen, Denmark, G2500) or 200 μL 0.01% PLL (Sigma, P-4832). Partial denudation of COCs was performed with a 127–129 μm diameter denudation pipette. Standard procedures were used for IVM (23 h in DMEM with 5% serum and eCG/hCG), IVF (23 h in TALP), and IVC (SOF with 10% serum); IVM and IVF were incubated at 38.5°C in 5% CO2 in air, and IVC at 5% CO2 in 5% O2. The study was based on a total of 1151 oocytes and 3 replicates. Day 8 blastocyst (BL) rates, BL kinetics, and morphology were used as endpoints to assess oocyte maturation. Kinetics/morphology were graded by a scoring system: hatched/excellent 3, expanded/good 2, non-expanded/poor 1. COCs placed in Gel- or PLL-coated dishes did not move during handling of the dishes. The BL rates in the Gel group were 37%, 25%, and 17%, and in the PLL group 24%, 21%, and 12%, for the control, intact, and partially denuded COCs, respectively. In the Gel group the BL rates showed a decreasing trend (P < 0.0036), whereas in only the PLL group the BL rates from the partially denuded COC differed from the control and the intact COCs (P < 0.008). No significant differences were seen between blastocyst kinetics (Gel/PLL 1.9/1.9, 1.8/1.9, 1.6/1.7) or morphology (Gel/PLL 2.2/2.4, 2.0/2.5, 2.2/2.1) in the control, intact or partially denuded groups. Fisher's exact test used. We conclude that it is possible to avoid movement of COCs during IVM without compromising oocyte maturation in dishes coated with Gel or PLL, if the cumulus layer is intact. The BL rates are compromised if COCs are partially denuded and the “cumulus tails” shortened before IVM in Gel or PLL coated dishes, whereas kinetics and morphology are unaffected. This research was funded by the Danish Research Agency, no. 23-023-0133.



2013 ◽  
Vol 25 (1) ◽  
pp. 280
Author(s):  
M. Nakakoji ◽  
H. Funahashi

The degree of cumulus expansion, an important step in oocyte maturation, of porcine cumulus–oocyte complexes (COC) derived from small follicles (SF: 1 to 2 mm in diameter) is known to be lower than those derived from middle follicles (MF: 3 to 6 mm in diameter). The objective of this study was to compare the abilities of hyaluronan (HA) synthesis of COC from SF and MF. Furthermore, the effect of oestradiol during pre-incubation of COC on proliferation of the cumulus cells was examined. Cumulus–oocyte complexes from SF and MF of porcine ovaries were cultured for in vitro maturation [IVM, in modified porcine oocyte medium (Yoshioka et al. 2008 J. Reprod. Dev. 54, 208–213) supplemented with 50 µM β-mercaptoethanol, 10 IU mL–1 of eCG, 10 IU mL–1 of hCG, and 1 mM dbcAMP for 20 h and then in the fresh medium without those supplements for another 24 h]. Hyaluronan production was quantified at 20 h after the start of IVM with a commercial HA-ELISA kit (20 COC/tube × 4 times). The number of cumulus cells was assessed 0 and 20 h after the start of IVM (50 COC × 4 times). Furthermore, proliferation of cumulus cells was examined after pre-culture of COC (n = 40 COC × 5 times) in modified porcine oocyte medium with various concentrations of oestradiol (0, 0.1, 1, and 10 ng mL–1) for 6 h. Statistical analyses of results from 4 to 5 replicated trials were performed by ANOVA with a Bonferroni-Dunn post-hoc test (significance, P < 0.05). The degree of cumulus expansion of COC from MF (n = 152) was higher than that of COC from SF (n = 156). The incidence of metaphase-II oocytes was significantly lower in COC from SF (n = 133; 48.9%) than in COC from MF (n = 148; 74.7%). The HA content of COC was higher in those from MF (20.8 µg/COC) than in those from SF (10.8 µg/COC), whereas the content per cumulus cell was not different because the numbers of cumulus cells at 0 and 20 h were also higher in COC (n = 200 in each group) from MF (3.0 × 103 and 3.3 × 103 cells, respectively) than from SF (2.0 × 103 and 2.5 × 103 cells, respectively). Cumulus cells proliferated significantly in the presence of oestradiol, regardless of the concentration, during pre-incubation for 6 h (2.5 to 2.8 × 103 cells), as compared with the oestradiol-free controls (2.2 × 103 cells). These results demonstrate that the different abilities of cumulus expansion between COC (n = 200 in each group) from SF and MF may be due to the number of cumulus cells per COC. Pre-incubation in the presence of oestradiol stimulates the proliferation of cumulus cells and may improve the oocyte maturation of COC derived from SF.



2017 ◽  
Vol 29 (1) ◽  
pp. 194
Author(s):  
S.-Y. Park ◽  
H.-J. Park ◽  
J.-W. Kim ◽  
J.-Y. Park ◽  
S.-G. Yang ◽  
...  

Bisphenol A (BPA) is well known as oestrogen-like chemical and it is widely used in plastic products. Many studies have reported that BPA exposure has a well-known toxicity effect on reproduction function, such as reducing the number of ovulated oocytes, oocyte quality, and maturation rate. Recently, BPA induced mitochondrial-derived reactive oxygen species (mito-ROS) and disrupted mitochondrial homeostasis by increasing of superoxide anions production. In this study, we investigated how the regulation of mito-ROS production may play a critical role in meiotic maturation and expansion of cumulus cells during the in vitro maturation progression of porcine oocytes. Furthermore, we investigated the toxicity effect of BPA exposure on mitochondrial functions and mito-ROS production during porcine oocyte maturation in vitro. All results were analysed using a 1-way ANOVA followed by Bonferroni’s and Tukey’s Multiple Comparison Test and t-tests. First, porcine oocytes were matured in NCSU-23 medium supplemented with BPA (50, 75, and 100 µM) for 44 h. Our results indicated that the rates of matured oocytes were significantly decreased by BPA exposure in a dose-dependent manner (69.4 ± 5.1, 50.9 ± 6.3, and 29.9 ± 5.8% for BPA treatments of 50, 75, and 100 μM) compared with control group (70.2 ± 7.8%; P < 0.05). Next, we confirmed the secretion functions of oocyte and cumulus cell of cumulus-oocyte complex (COC) and ROS production. Cumulus cell secretion factors (has2, tnfaip6, and cx37) mRNA expression in COC were decreased in the BPA-treated (75 µM) group. In addition, mRNA expressions of mitochondrial-specific antioxidant enzymes (sod2, P < 0.001; prdx3, P < 0.01; prdx5, P < 0.001) and mitochondrial apoptosis genes (bax and caspase-3, P < 0.01) were significantly increased in COC of the BPA-treated (75 µM) group. We measured mitochondrial membrane potential and mito-ROS production using JC-1 analysis and Mito-SOX staining, respectively. The BPA treatment caused a rapid decrease of mitochondrial membrane potential maintenance and increase of mito-ROS production in porcine COC. Moreover, mitochondrial-specific ROS scavenger, Mito-Tempo (0.1 µM) treatment was significantly increased the meiotic maturation of porcine oocytes compared with control group (78.5 ± 3.5 v. 65.8 ± 5.0%; P < 0.05). Based on these results, we first confirmed that BPA exposure reduces the meiotic maturation and cumulus cells expansion of COC by increasing mito-ROS production during porcine oocyte maturation in vitro. Therefore, controlling of mito-ROS for mitochondrial function maintenance and apoptosis plays a critical role in improving porcine oocyte maturation in vitro. This work was supported by grants from the Next-Generation BioGreen 21 Program (PJ01117604) and the Bio-industry Technology Development Program (316037–04–1-HD020) through the Rural Development Administration, the Ministry of Agriculture, Food and Rural Affairs, Republic of Korea.



2011 ◽  
Vol 301 (1) ◽  
pp. E196-E209 ◽  
Author(s):  
Young S. Lee ◽  
Catherine A. VandeVoort ◽  
John P. Gaughan ◽  
Uros Midic ◽  
Zoran Obradovic ◽  
...  

The elaboration of a quality oocyte is integrally linked to the correct developmental progression of cumulus cell phenotype. In humans and nonhuman primates, oocyte quality is diminished with in vitro maturation. To determine the changes in gene expression in rhesus monkey cumulus cells (CC) that occur during the final day prior to oocyte maturation and how these changes differ between in vitro (IVM) and in vivo maturation (VVM), we completed a detailed comparison of transcriptomes using the Affymetrix gene array. We observed a large number of genes differing in expression when comparing IVM-CC and VVM-CC directly but a much larger number of differences when comparing the transitions from the prematuration to the post-IVM and post-VVM states. We observed a truncation or delay in the normal pattern of gene regulation but also remarkable compensatory changes in gene expression during IVM. Among the genes affected by IVM are those that contribute to productive cell-cell interactions between cumulus cell and oocyte and between cumulus cells. Numerous genes involved in lipid metabolism are incorrectly regulated during IVM, and the synthesis of sex hormones appears not to be suppressed during IVM. We identified a panel of 24 marker genes, the expression of which should provide the foundation for understanding how IVM can be improved for monitoring IVM conditions and for diagnosing oocyte quality.



2006 ◽  
Vol 18 (2) ◽  
pp. 249 ◽  
Author(s):  
N. Maedomari ◽  
N. Kashiwazaki ◽  
M. Ozawa ◽  
A. Takizawa ◽  
J. Noguchi ◽  
...  

It is generally accepted that cumulus cells (CCs) support the nuclear maturation of immature oocytes in mammals. However, the precise mechanism of interaction between cumulus cells and oocytes has not been clarified. Furthermore, the role of cumulus cells in embryonic development has not been reported. In the present study, the effect of denuding cumulus cells from porcine oocytes on oocyte maturation, ertilization, and their subsequent development to the blastocyst stage was examined in vitro. In vitro maturation, fertilization, and culture were carried out as previously reported (Kikuchi et al. 2002 Biol. Reprod. 66, 1033-1041). Porcine cumulus-oocyte complexes (COCs) were collected; some of them were completely denuded of cumulus cells immediately after the collection (DO-0 group). The remaining intact COCs and the DO-0 oocytes were cultured for 24 h in the presence of dbcAMP and hormones. After the initial culture, some of the intact COCs were denuded either completely (DO-24 group) or partially (H-DO-24 group). Additionally, some of DO-24 oocytes were co-cultured with the cumulus cells removed at 0 h and pre-cultured for 24 h (DO-24 + CCs group). The denuded oocytes in each experimental group and intact COCs (control) were further cultured for total 46 h. The remaining oocytes with a first polar body were either examined for the levels of intracellular glutathione (GSH) or fertilized in vitro with frozen-thawed boar spermatozoa. The inseminated oocytes were cultured and examined for their fertilization status after 10 h and for their developmental competence after 6 days. Data were analyzed by ANOVA, followed by the Duncan's multiple range tests. The maturation rates of all denuded groups were significantly lower (P < 0.05; 34.3 to 45.0%) than that of the control group (64.5%). Intracellular GSH concentrations of all denuded groups were also significantly lower (P < 0.05; 4.03 to 7.00 pmol/oocyte) than that of the control group (9.60 pmol/oocyte); however, the GSH level of H-DO-24 oocytes was significantly higher (P < 0.05) than the GSH levels in the other denuded groups. Male pronuclear formation rates of completely denuded oocytes (DO-0, DO-24, and DO-24 + CCs groups) were significantly lower (P < 0.05; 41.4 to 59.3%) than those of the control (89.4%) and the H-DO-24 (80.0%) groups. The blastocyst rate of the control group was significantly higher (P < 0.05; 19.9%) than that of H-DO-24 group (11.6%), and these rates were significantly higher (P < 0.05) than those of the completely denuded groups (3.0 to 4.5%). The results suggest that the presence of cumulus cells during maturation culture improves nuclear maturation of oocytes and plays an important role in embryonic development to the blastocyst stage in vitro.



2017 ◽  
Vol 29 (1) ◽  
pp. 143
Author(s):  
J.-X. Jin ◽  
S. Lee ◽  
A. Taweechaipaisankul ◽  
G. A. Kim ◽  
B. C. Lee

Melatonin (N-acetyl-5-methoxytryptamine) is the hormone synthesised from the mammalian pineal gland, which has an antioxidant property and regulates physiological processes such as cellular metabolism. It is well known that melatonin affects in vitro maturation of oocytes and embryonic development in many species. However, limited information is available on the underlying beneficial effects of melatonin. Sonic Hedgehog (Shh) signalling is important for follicular development, oocyte maturation, and embryo development. To elucidate the relationship between melatonin and Shh signalling, we designed an experiment with the following three groups: (1) control, (2) melatonin, and (3) melatonin with cyclopamine (smoothened inhibitor) during porcine in vitro maturation. Porcine ovaries were collected from prepubertal gilts at a local slaughterhouse and transported to the laboratory at 28 to 32°C. The contents of follicles 3 to 6 mm in diameter were recovered by aspiration with an 18 G needle. Cumulus–oocyte complexes were pooled and cultured in TCM-199 medium for 44 h. The aim of this study was to evaluate the effects of melatonin (10−9 M) with or without cyclopamine (2 μM) on cumulus cell expansion (a total of 432 cumulus–oocyte complexes were used in 3 replicates), embryo development after parthenogenetic activation (a total of 432 oocytes were used in 4 replicates). Moreover, we detected gene expression related to cumulus expansion, oocyte maturation, and hedgehog signalling in cumulus cells and oocyte. Results indicated that melatonin treatment significantly increased cumulus expansion index (3.75 ± 0.02 v. 3.51 ± 0.03 and 3.59 ± 0.05, respectively; P < 0.05) and blastocyst formation rates (30.4 ± 2.4 v. 21.9 ± 2.2 and 20.0 ± 2.2, respectively; P < 0.05) compared with control and melatonin with cyclopamine. In addition, the expression of cumulus expansion-related genes (Ptgs1, Ptgs2, Has2, Ptx-3, and Tnfaip6) and hedgehog signalling-related genes (Shh, Pthc1, Smo, and Gli-1) in cumulus cells were up-regulated in melatonin treatment compared with control and melatonin with cyclopamine. Similarly, the expressions of oocyte maturation-related genes (GDF9 and BMP15) in porcine oocytes were up-regulated in melatonin treatment compared with control and melatonin with cyclopamine. In conclusion, Shh signalling mediated melatonin to improve porcine cumulus cell expansion, oocyte maturation, and subsequent embryo development. Further studies are needed to evaluate the effect of melatonin on protein levels of Shh signalling. Statistical analyses were performed using SPSS 22.0 (SPSS Inc., Chicago, IL, USA). All data were tested for normality and homoscedasticity and then subjected to one-way ANOVA, followed by Duncan’s multiple range test (when the variances were assumed to be equal) or Dunnet’s T3 test (when the variances were assumed to be unequal) to determine differences among experimental groups. All results are expressed as means ± SEM; P-values < 0.05 were considered to be statistically significant. This study was supported by Ministry of Trade, Industry and Energy (#10048948), Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry, and Fisheries (#311011–05–4-SB010, #114059–03–2-SB010), National Research Foundation (2016M3A9B6903410), China Scholarship Council (CSC, No. 2015–3022), Research Institute for Veterinary Science, TS Corporation, and the BK21 plus program.



2016 ◽  
Vol 28 (2) ◽  
pp. 222
Author(s):  
M. S. Araujo ◽  
M. D. Guastali ◽  
A. C. S. Castilho ◽  
F. Landim-Alvarenga

The insulin-like growth factor-1 recombinant -3 (IGF-1-LongR3), a synthetic analogue of IGF-1 with increased bioavailability has not yet been used in vitro maturation (IVM) medium of bovine oocytes. Therefore, the aim of this study was to evaluate and compare the addition effects of IGF-1-LongR3 or IGF-1 in IVM bovine oocytes on meiotic progression, apoptosis, and profile of oocytes genes (GDF9, BMP15, BAX, BCL2, OOSP1, IGFBP2, IGFBP4 and IGFBP5) and genes in cumulus cells (AREG, EGFR, FSHR, COX2, BAX, BCL2, IGFBP2, IGFBP4 and IGFBP5). Bovine ovaries were collected in slaughterhouses, and 739 oocytes with grades 1 or 2 were selected after aspiration of 2- to 8-mm follicles. IVM was carried out in TCM199 with FSH, LH, and antibiotics (BM) supplemented with 100 ng mL–1 IGF-1 or 100 ng mL–1 LongR3-IGF-1. Control oocytes were matured in BM supplemented with 0.1% polyvinyl alcohol (PVA) or 10% FCS. For all groups, maturation was performed during 22–24 h in an incubator at 38.5°C and 5% CO2 in air. Subsequently oocytes were denuded and analysed for apoptosis, nuclear maturation, and gene expression by TUNEL assay, staining Hoechst 33342, and RT-qPCR, respectively. Statistical analysis was performed using a linear mixed effects model, which correlated the change in metaphase stage 1 to 2 and the absence of apoptosis among the experimental groups. ANOVA and Tukey tests were used to analyse the results obtained by RT-qPCR. After 10 replicates of IVM, 339 oocytes were evaluated for meiotic progression and apoptosis and 400 oocytes for gene expression. There was no statistical difference between the experimental groups with respect to meiotic progression and apoptosis. BCL2 and IGFBP4 gene were less expressed in oocytes matured with IGF-1 and LongR3-IGF-1 compared with control groups. GFBP4 was also less expressed in cumulus cell of oocytes from the experimental groups. Moreover COX2 expression was statistically elevated in cumulus cells matured in the presence of IGF-1 and LongR3-IGF-1 It was possible to perform IVM of bovine oocytes in the presence of LongR3-IGF-1, allowing its use in replacement of IGF-1 and FCS. The results of this study will provide more information on the interaction of IGF with the IGFBP and its importance for oocyte maturation.



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