scholarly journals Melatonin Improves Oocyte Maturation and Mitochondrial Functions by Reducing Bisphenol A-Derived Superoxide in Porcine Oocytes In Vitro

2018 ◽  
Vol 19 (11) ◽  
pp. 3422 ◽  
Author(s):  
Hyo-Jin Park ◽  
Soo-Yong Park ◽  
Jin-Woo Kim ◽  
Seul-Gi Yang ◽  
Min-Ji Kim ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Oocyte Maturation ◽  
Cell Damage ◽  
Cumulus Cell ◽  
Superoxide Production ◽  
Positive Effects ◽  
Mitochondrial Functions ◽  
Porcine Oocyte ◽  
Antioxidative Effects

Bisphenol A (BPA) is synthetic organic compound that exhibits estrogen-like properties and it induces mitochondrial superoxide production. Melatonin (Mela) protects against BPA-mediated cell damage and apoptosis. However, the antioxidative effects of Mela against BPA-induced superoxide production in porcine oocytes are still not known. In this study, we investigated the antioxidative effects of Mela against BPA-derived superoxide on oocyte maturation in pigs. To investigate the effects of the superoxide specific scavenger, Mito-TEMPO, on porcine oocyte maturation in response to BPA exposure apoptosis proteins, we treated the oocytes with Mito-TEMPO (0.1 µM) after pre-treating them with BPA (75 µM) for 22 h. As expected, the reduction in meiotic maturation and cumulus cell expansion of cumulus-oocyte-complexes (COCs) in the BPA (75 µM) treated group was recovered (p < 0.01) by treatment with Mito-TEMPO (0.1 µM). An increase in the levels of mitochondrial apoptotic proteins (AIF, cleaved Cas 3 and cleaved Parp1) in response to BPA-induced damage was also reduced by Mito-TEMPO treatment in porcine COCs. Interestingly, we confirmed the positive effects of Mela with respect to superoxide production upon BPA exposure during oocyte maturation and also confirmed the reduction in mitochondrial apoptosis in Mela (0.1 µM)-treated porcine COCs. These results provide evidence for the first time that antioxidative effects of Mela on BPA-derived superoxide improve porcine oocyte maturation.

scholarly journals Exposure of Triclosan in Porcine Oocyte Leads to Superoxide Production and Mitochondrial-Mediated Apoptosis during In Vitro Maturation

2020 ◽  
Vol 21 (9) ◽  
pp. 3050 ◽  
Author(s):  
Hyo-Jin Park ◽  
Bong-Seok Song ◽  
Jin-Woo Kim ◽  
Seul-Gi Yang ◽  
Sun-Uk Kim ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Cumulus Cell ◽  
Superoxide Production ◽  
Mrna Levels ◽  
Female Reproduction ◽  
Mitochondrial Superoxide ◽  
Porcine Oocyte

While triclosan (TCS) exerts detrimental effects on female reproduction, the effect of TCS-derived toxins on porcine oocytes during in vitro maturation (IVM) is unclear. This study investigated the effects of TCS on mitochondrion-derived reactive oxygen species (ROS) production and apoptosis pathways during porcine oocyte maturation. Porcine oocytes were treated with TCS (1, 10, and 100 μM) and triphenylphosphonium chloride (Mito-TEMPO; 0.1 μM), and matured cumulus oocyte complexes (COCs) were stained with orcein, dichlorofluorescein diacetate (DCF-DA), and Mito-SOX. Proteins and mRNA levels of factors related to cumulus expansion and mitochondrion-mediated apoptosis and antioxidant enzymes were analyzed by western blotting and reverse-transcription polymerase chain reaction (RT-PCR), respectively. Meiotic maturation and cumulus cell expansion significantly decreased for COCs after TCS treatment along with an increase in mitochondrial superoxide levels at 44 h of IVM. Further, mitochondrion-related antioxidant enzymes and apoptosis markers were significantly elevated in porcine COCs following TCS-mediated oxidative damage. The protective effect of Mito-TEMPO as a specific superoxide scavenger from TCS toxin improved the maturation capacity of porcine COCs. Mito-TEMPO downregulated the mitochondrial apoptosis of TCS-exposed porcine COCs by reducing superoxide level. In conclusion, our data demonstrate that TCS mediates toxicity during porcine oocyte maturation through superoxide production and mitochondrion-mediated apoptosis.

scholarly journals Butylparaben Is Toxic to Porcine Oocyte Maturation and Subsequent Embryonic Development Following In Vitro Fertilization

2020 ◽  
Vol 21 (10) ◽  
pp. 3692 ◽  
Author(s):  
Pil-Soo Jeong ◽  
Sanghoon Lee ◽  
Soo-Hyun Park ◽  
Min Ju Kim ◽  
Hyo-Gu Kang ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Oocyte Maturation ◽  
Mitochondrial Function ◽  
Cumulus Cell ◽  
Annexin V ◽  
Ros Generation ◽  
Vitro Fertilization ◽  
Porcine Oocyte ◽  
Mitochondrial Distribution

Parabens are widely used in personal care products due to their antimicrobial effects. Although the toxicity of parabens has been reported, little information is available on the toxicity of butylparaben (BP) on oocyte maturation. Therefore, we investigated the effects of various concentrations of BP (0 μM, 100 μM, 200 μM, 300 μM, 400 μM, and 500 μM) on the in vitro maturation of porcine oocytes. BP supplementation at a concentration greater than 300 μM significantly reduced the proportion of complete cumulus cell expansion and metaphase II oocytes compared to the control. The 300 μM BP significantly decreased fertilization, cleavage, and blastocyst formation rates with lower total cell numbers and a higher rate of apoptosis in blastocysts compared to the control. The BP-treated oocytes showed significantly higher reactive oxygen species (ROS) levels, and lower glutathione (GSH) levels than the control. BP significantly increased the aberrant mitochondrial distribution and decreased mitochondrial function compared to the control. BP-treated oocytes exhibited significantly higher percentage of γ-H2AX, annexin V-positive oocytes and expression of LC3 than the control. In conclusion, we demonstrated that BP impaired oocyte maturation and subsequent embryonic development, by inducing ROS generation and reducing GSH levels. Furthermore, BP disrupted mitochondrial function and triggered DNA damage, early apoptosis, and autophagy in oocytes.

265 HYALURONAN SYNTHESIS ABILITY OF PORCINE CUMULUS - OOCYTE COMPLEXES DERIVED FROM SMALL FOLLICLES

2013 ◽  
Vol 25 (1) ◽  
pp. 280
Author(s):  
M. Nakakoji ◽  
H. Funahashi
Keyword(s):  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Cumulus Expansion ◽  
Elisa Kit ◽  
Porcine Oocyte ◽  
Post Hoc ◽  
Metaphase Ii Oocytes

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.

172 THE APOPTOTIC EFFECTS OF BISPHENOL A-INDUCED MITOCHONDRIAL-DERIVED REACTIVE OXYGEN SPECIES ON MATURATION OF PORCINE OOCYTES IN VITRO

2017 ◽  
Vol 29 (1) ◽  
pp. 194
Author(s):  
S.-Y. Park ◽  
H.-J. Park ◽  
J.-W. Kim ◽  
J.-Y. Park ◽  
S.-G. Yang ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Critical Role ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Meiotic Maturation ◽  
Control Group ◽  
Ros Production ◽  
Maturation In Vitro ◽  
Porcine Oocyte

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.

Exogenous Ganglioside GT1b Enhances Porcine Oocyte Maturation, Including the Cumulus Cell Expansion and Activation of EGFR and ERK1/2 Signaling

2020 ◽  
Vol 27 (1) ◽  
pp. 278-289
Author(s):  
Jin-Woo Kim ◽  
Hyo-Jin Park ◽  
Seul-Gi Yang ◽  
Min-Ji Kim ◽  
In-Su Kim ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Cell Expansion ◽  
Cumulus Cell ◽  
Porcine Oocyte ◽  
Ganglioside Gt1b

254 9-cis RETINOIC ACID INHIBITS CUMULUS CELL APOPTOSIS DURING IN VITRO MATURATION OF BOVINE OOCYTES THROUGH INHIBITION OF AP-1 PATHWAY

2011 ◽  
Vol 23 (1) ◽  
pp. 225
Author(s):  
G. K. Deb ◽  
S. R. Dey ◽  
J. I. Bang ◽  
S. J. Cho ◽  
T. H. Kwon ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Tumor Necrosis Factor ◽  
Oocyte Maturation ◽  
Tumor Necrosis ◽  
In Vitro Maturation ◽  
Tumor Necrosis Factor Α ◽  
Cumulus Cell ◽  
Factor Α ◽  
Necrosis Factor

Cumulus cells (CC) play a critical role in oocyte maturation and fertilization via gap junctions. The oocyte itself maintains CC health to favour oocyte maturation via the secretion of paracrine growth factors. However, the antiapoptotic effects of oocyte-secreted factors follow a gradient from the site of the oocytes. Moreover, degrees of CC apoptosis are inversely related to the in vitro embryo development. Therefore, inhibition of CC apoptosis is important for efficient in vitro embryo development. The beneficial effects of retinoic acid (RA) during in vitro embryo production are well known in different species. However, the effect of RA on CC apoptosis is yet to be elucidated. All-trans RA and 9-cis RA are the natural components of retinoids, and all-trans RA are metabolized to 9-cis RA for physiological function. Therefore, the objective of the present study was to evaluate the effect of 9-cis RA on the mechanism for inhibition of apoptosis in CC. Slaughterhouse cumulus–oocyte complexes (COC) were matured in vitro in TCM-199-based in vitro maturation medium containing 0 or 5 mM 9-cis RA for 23 to 24 h (15 COC/100 μL droplet) at 38.5°C and 5% CO2 in air with maximum humidity. Following in vitro maturation, COC of a droplet were fixed in 4% paraformaldehyde for TUNEL staining using In Situ Cell Death Detection Kit (Roche, Budapest, Hungary). The proportion of apoptotic cells was estimated using Olympus Soft Imaging Solutions GmBH (Olympus, Münster, Germany). The COC of the remaining droplet were denuded. The CC were frozen and stored at –80°C. The CC of 3 different cultures were pooled, and total RNA was extracted using RNeasy Mini Kit (Qiagen, Valencia, CA, USA). Total RNA was reverse transcribed into cDNA using Omniscript Reverse Transcription kit (Qiagen). Relative expression of candidate genes was quantified using SYBER green real-time PCR with ΔΔ CT method. The expression was normalized against β-actin, glyceraldehyde 3-phosphate dehydrogenase, and 18s rRNA genes expression. The PCR efficiencies were calculated using relative calibration curves following 10-fold dilution series at 5 measuring points. Data were analysed for one-way ANOVA. The proportion of apoptotic cells was low in the 9-cis RA group (1.3 v. 3.3% of total CC; P < 0.05). Expression of tumor necrosis factor-α (11.1 v. 1.0; P < 0.001), caspase9 (2.0 v. 1.0; P < 0.01), and caspase3 (2.1 v. 1.0; P < 0.001) genes was down-regulated in the 9-cis RA group, whereas expression of Bcl2 gene was increased (1.0 v. 2.6 fold; P < 0.05). Moreover, the expression of c-fos gene of AP-1 pathway was down-regulated (1.9 v. 1 fold; P < 0.05) in the 9-cis RA group. Retinoic acid suppressed the expression of NF-kB, which in turn inhibits tumor necrosis factor-α-mediated caspase activity. However, the expression of NF-kB in CC was not affected by 9-cis RA (1.1 v. 1.0; P > 0.05). In conclusion, the present study indicated that 9-cis RA may inhibit cumulus cell apoptosis through suppression of AP-1 pathway. This work was partly supported by a scholarship from the BK21 program, the KRF (KRF-2008-211-F00011), the IPET (108068-03-1-SB010), and the KOSEF (10525010001-05N2501-00110).

260 EVALUATION OF PORCINE IN VITRO PRODUCTION WITH THE ADDITION OF CHITOSAN TO CULTURE MEDIA

2015 ◽  
Vol 27 (1) ◽  
pp. 219 ◽  
Author(s):  
F. García ◽  
Y. Ducolomb ◽  
S. P. Miranda-Castro ◽  
J. F. De la Torre-Sánchez ◽  
S. Romo
Keyword(s):  
Embryo Development ◽  
Oocyte Maturation ◽  
Culture Media ◽  
Biological Properties ◽  
In Vitro Production ◽  
Porcine Oocyte ◽  
Main Component ◽  
Vitro Production ◽  
Positive Effect

Chitosan is a partially deacetylated polymer obtained from the alkaline deacetylation of chitin, which is a glucose-based unbranched polysaccharide widely distributed in nature as the main component of exoskeletons of crustaceans and insects. Chitosan has a variety of physicochemical and biological properties resulting in numerous applications. In addition to its lack of toxicity and allergenicity, its biocompatibility, biodegradability, and bioactivity make it a very attractive substance for diverse applications as a biomaterial in pharmaceutical and medical fields. Chitosan stimulates cell growth and it has been used in fibroblast culture, increasing cell proliferation. For these reasons, it is important to evaluate if this polymer has a positive effect on embryo production. The aim of this study was to evaluate porcine oocyte maturation and embryo development, comparing the effect of supplementing different concentrations of chitosan to the maturation (MM) and development media (DM). Cumulus-oocyte complexes (COC) were aspirated from ovarian follicles of slaughtered sows. The COC were matured in supplemented TCM-199 (MM) and incubated for 44 h. All incubations were performed at 38.5°C, with 5% CO2 in air and humidity at saturation. After maturation IVF was performed, frozen-thawed semen from the same boar was used and gametes were co-incubated in MTBM for 7 h. Then, putative zygotes were cultured in NCSU-23 (DM) for 144 h. The following experiments were performed: 1) addition of 0 (control), 35, 50, 100, and 150 ppm chitosan to the MM (n = 1353), 2) addition of 0, 50, 100, and 150 ppm chitosan to the DM (n = 739), 3) addition of 0, 50, 100, and 150 ppm of chitosan to the MM first and then the same concentrations to the DM (n = 702). When chitosan was added to the MM, the highest percentage of matured oocytes (metaphase II) was obtained in the 50 ppm treatment (87%, P < 0.05) when compared with the control, 100, and 150 ppm groups (78, 78, and 82%, respectively). Regarding the percentage of blastocysts, there were no differences when comparing the treatment and the control groups (ranging from 12 to 13%). After addition of chitosan to the putative zygotes in the DM, the percentage of morulae in the 150 ppm treatment was significantly increased with regard to the other groups (54 v. 46%, respectively, P < 0.05). When adding chitosan to both MM and DM, there was no effect on embryo development. It is concluded that the addition of chitosan to the MM at a concentration of 50 ppm significantly improved oocyte maturation and a concentration of 150 ppm in the DM increased the percentage of morulae. Chitosan had a positive effect on oocyte maturation and embryo development. These results justify further investigations to find out if chitosan can be useful as a supplement for chemically defined media.

188 IMPROVEMENT OF IN VITRO CANINE OOCYTE MATURATION BY OVIDUCTAL SECRETOME

2017 ◽  
Vol 29 (1) ◽  
pp. 202 ◽  
Author(s):  
A. Lange-Consiglio ◽  
C. Perrini ◽  
P. Esposti ◽  
F. Cremonesi
Keyword(s):  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Cumulus Cell ◽  
Follicular Development ◽  
Cumulus Cells ◽  
Chi Square ◽  
Cell Layers ◽  
Hoechst Staining

The in vitro maturation of canine oocyte is problematic because it is difficult to reproduce the oviducal microenvironment where the in vivo maturation occurs. Because cells are able to communicate with each other by paracrine action, oviducal cells could be in vitro cultivated to obtain the conditioned medium (CM) consisting of soluble factors and microvesicles (MV), which represent a carrier for nonsoluble molecules including microRNA. The aim of the present work was to investigate the effect of the addition of CM or MV, secreted by oviducal cells, to the canine in vitro maturation medium. To generate CM, cells from oviducts of 3 animals in late oestrus were cultured for 5 days at 38.5°C in a humidified atmosphere of 5% CO2. Supernatants were collected, pooled, centrifuged at 2500 × g, and stored at −80°C. Microvesicles were obtained by ultracentrifugation of CM at 100,000 × g for 1 h at 4°C and measured for concentration and size by a Nanosight instrument. Ovaries were obtained from 50 healthy domestic bitches (1–4 years old) of different breeds that underwent ovariectomy regardless of the oestrous cycle. Cumulus-oocyte complexes were released by slicing the ovarian cortex with a scalpel blade, and only Grade 1 cumulus-oocyte complexes (darkly granulated cytoplasm and surrounded by 3 or more compact cumulus cell layers) 110 to 120 µm in diameter were selected for culture. Maturation was performed at 38.5°C in a humidified atmosphere of 5% CO2 and 5% of O2 in bi-phasic systems: 24 h in SOF with 5.0 μg mL−1 of LH followed by 48 h in SOF supplemented with 10% of oestrous bitch serum and 10% CM or 50, 75, 100, or 150 × 106 MV mL−1 labelled with PKH-26. Control was the same medium without CM or MV. Oocytes were observed under a fluorescent microscope to detect metaphase II (MII), by Hoechst staining, and the incorporation of MV. Statistical analysis was performed by chi-square test. Results show that canine oviducal cells secreted MV of 234 ± 23 nm in size, underling that these MV fall within the shedding vesicles category. The incorporation of labelled MV occurred at first in cumulus cells, at 48 h of maturation, and then, at 72 h, in oocyte cytoplasm. These MV had a positive effect on maturation rate (MII) at the concentration of 75 and 100 × 106 MV mL−1 compared with CM and control (20.34 and 21.82 v. 9.09 and 3.95%, respectively). The concentration of 150 × 106 MV mL−1 provided only 9.26% of MII. To understand the role of MV, we assessed the expression of 3 microRNA (miRNA-30b, miR-375, and miR-503) that are involved in some key pathways (WNT, MAPK, ERbB, and TGFβ) regulating follicular development and meiotic resumption. The lower rate of MII with the higher concentration of MV is possibly due to the high level of miR-375, which recent literature shows to suppress the TGFβ pathway, leading to impaired oocyte maturation. In conclusion, the oviducal MV, or specific microRNA, are involved in cellular trafficking during oocyte maturation, and their possible use in vitro could facilitate the exploitation of canine reproductive biotechnologies.

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
Keyword(s):  
Gene Expression ◽  
Oocyte Maturation ◽  
Cell Expansion ◽  
Cholesterol Biosynthesis ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Mitogen Activated Protein Kinase ◽  
Control Group ◽  
Cumulus Expansion

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.

173 MELATONIN ALLEVIATES THE ENDOPLASMIC RETICULUM STRESS THROUGH THE REGULATING OF UNFOLDING PROTEIN RESPONSE SIGNALING DURING PORCINE OOCYTE MATURATION IN VITRO

2017 ◽  
Vol 29 (1) ◽  
pp. 195 ◽  
Author(s):  
J.-Y. Park ◽  
H.-J. Park ◽  
J.-W. Kim ◽  
S.-Y. Park ◽  
S.-G. Yang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Er Stress ◽  
Oocyte Maturation ◽  
Caspase 3 ◽  
Oxygen Species ◽  
Melatonin Treatment ◽  
Maturation In Vitro ◽  
Porcine Oocyte ◽  
Protein Response

Unfolding protein response (UPR) is a defence mechanism during endoplasmic reticulum (ER) stress in mammalian cells. Especially, UPR genes and regulation of reactive oxygen species is involved in ER stress response on porcine oocyte maturation in vitro. Some studies have shown that melatonin treatment results in reducing oxidative stress, a protective function of free radical damage in oocyte maturation and embryo development. Also, melatonin has an important role in reducing reactive oxygen species and ER stress. However, it is unknown how the changes of UPR genes expression levels are affected the porcine oocyte maturation. In addition, there are no reports about ER stress recovery mechanism by melatonin during porcine oocyte maturation. Here, we investigated the UPR signal genes (Bip/Grp78, Atf4, p90/p50Atf6, and Xbp1) and ER-stress mediated apoptosis factors (Chop and Cleaved caspase 3) in porcine oocyte maturation in vitro. Expression of Chop and Cleaved caspase 3 mRNA levels were significantly increased (P < 0.01) in matured oocytes (metaphase II; 44 h) in vitro. Porcine oocytes were cultured in maturation medium with ER stress inducer, tunicamycin (Tm), and supplemented with various concentrations (1, 5, and 10 μg mL−1) of Tm for 0 to 44 h. Our results indicated that the proportion of matured oocytes was significantly decreased in Tm-treated groups in a dose-dependent manner (60.1 ± 1.3, 46.5 ± 2.1, and 38.9 ± 5.1% at 1, 5, and 10 μg mL−1 of Tm) compared with the control group (76.6 ± 1.9%). Likewise, mRNA expression of UPR regulator genes (Grp78/Bip, Aft4, Xbp1, Chop, and Cleaved caspase 3) was decreased by melatonin treatment (0.1 μM, 22–44 h) after pretreatment of Tm (5 μg mL−1, 0–22 h) during oocyte maturation. Our results demonstrated that the roles of melatonin as UPR signaling regulator for reducing ER stress are essential for promotion of porcine oocyte maturation and cumulus cell expansion of cumulus-oocyte complex. Moreover, the current study was initiated to confirm a functional link between effect of melatonin and regulating of UPR signaling in porcine oocytes maturation. These results suggest that melatonin improve the oocyte maturation and cumulus cells expansion by regulating of UPR signal genes against the ER stress during the porcine in vitro maturation process. 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.

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