scholarly journals Pyruvate prevents aging of mouse oocytes

Reproduction ◽  
2009 ◽  
Vol 138 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Na Liu ◽  
Yan-Guang Wu ◽  
Guo-Cheng Lan ◽  
Hong-Shu Sui ◽  
Li Ge ◽  
...  

Inhibiting oocyte aging is important not only for healthy reproduction but also for the success of assisted reproduction techniques. Although our previous studies showed that cumulus cells accelerated aging of mouse oocytes, the underlying mechanism is unknown. The objective of this paper was to study the effects of pyruvate and cumulus cells on mouse oocyte aging. Freshly ovulated mouse cumulus–oocyte complexes (COCs) or cumulus-denuded oocytes (DOs) were cultured in Chatot-Ziomek-Bavister (CZB) medium or COC-conditioned CZB medium supplemented with different concentrations of pyruvate before being examined for aging signs and developmental potential. Pyruvate supplementation to CZB medium decreased rates of ethanol-induced activation in both COCs and DOs by maintaining their maturation-promoting factor activities, but more pyruvate was needed for COCs than for DOs. Addition of pyruvate to the COC-conditioned CZB also alleviated aging of DOs. Observations on cortical granules, level of BCL2 proteins, histone acetylation, intracellular concentration of glutathione, and embryo development all confirmed that pyruvate supplementation inhibited aging of mouse oocytes. It is concluded that the aging of mouse oocytes, facilitated by culture in COCs, can be partially prevented by the addition of pyruvate to the culture medium.

2007 ◽  
Vol 19 (1) ◽  
pp. 165 ◽  
Author(s):  
J. Xu ◽  
L.-Y. Sung ◽  
J. Zhang ◽  
X. Tian ◽  
Y. E. Chen ◽  
...  

Nuclear reprogramming is dependent upon a number of factors, including chromatin organization and modification. Trychostatin A (TSA), a histone deacetylase inhibitor, was used to increase histone acetylation and to improve reprogrammability in both cattle and mice. The objective of the study was to determine whether TSA could improve the pre-implantational development potential of rabbit nuclear transplant (NT) embryos. Rabbit oocytes were flushed from the oviducts of superovulated donors treated with the regime of FSH and hCG. Cumulus cells were then denuded from the oocytes by incubation in 0.5% hyaluronidase and pipetting. Oocyte enucleation was conducted in 10% FBS M199 and confirmed under fluorescence microscopy. Cumulus cells were prepared as nuclear donors for NT; a donor cell with the diameter approximately 15–19 µm was transferred into the perivitelline space of an enucleated oocyte, and subsequently fused with the oocyte recipient by application of 3 direct current pulses at 3.2 kV cm−1 for a duration of 20 µs/pulse. Fused embryos were activated by the same electrical stimulation regime described above, and subsequently cultured in M199 + 10% FBS containing 2.0 mM 6-dimethylaminopurine (DMAP) and 5 µg mL−1 cycloheximide for 1 h. Rabbit NT embryos were cultured in 5 nM TSA-2.5% FBS-B2 medium for 10 h before being transferred into regular medium (FBS-B2). The TSA-treated embryos (5 nM vs. 0 nM) were cultured in 400 µL FBS-B2 medium for 5 days in 5% CO2 in a humidified atmosphere at 38.5°C (initiation of activation = Day 0). NT embryo development to cleaved (2 to 4 cell), morula, and blastocyst stages was evaluated on Day 2, Day 3, and Day 5, respectively. The selected NT blastocysts were counted for cell numbers following Hoechst 33342 epifluorescenin staining. The results (Table 1) showed that there was no difference on pre-implantational development of cloned embryos between TSA-added and control groups (P > 0.05). However, a significantly higher cell number per NT blastocyst was found in the TSA-added group (357 vs. 113; P < 0.05). This indicated that the blastocyst quality in NT embryos was improved with the addition of TSA by increasing histone acetylation activity. The developmental potential of TSA-treated NT embryos to term is under investigation. Table 1.Effects of TSA on the pre-implantational development of cloned rabbit embryos This work was supported by NIH/NCRR-SBIR grant: 1R43RR020261-01.


Zygote ◽  
2015 ◽  
Vol 24 (2) ◽  
pp. 195-205 ◽  
Author(s):  
Qian Li ◽  
Long-Bo Cui

SummaryThe postovulatory aging of oocytes eventually affects the development of oocytes and embryos. Oxidative stress is known to accelerate the onset of apoptosis in oocytes and influence their capacity for fertilisation. This study aimed to reveal the roles of temperature and the antioxidant N-acetyl-l-cysteine in preventing the aging of postovulatory mouse oocytes. First, newly ovulated mouse oocytes were cultured at various temperature and time combinations in HCZB medium with varying concentrations of N-acetyl-l-cysteine to assess signs of aging and developmental potential. When cultured in HCZB with 300 μM N-acetyl-l-cysteine at different temperature and incubation time combinations (namely 25°C for 12 h, 15°C for 24 h and 5°C for 12 h), the increase in the susceptibility of oocytes to activating stimuli was efficiently prevented, and the developmental potential was maintained following Sr2+ activation or in vitro fertilisation. After incubation at either 15°C for 36 h or 5°C for 24 h, oocytes that had decreased blastocyst rates displayed unrecoverable abnormal cortical granule distribution together with decreased BCL2 levels, total glutathione concentrations and glutathione/glutathione disulphide (GSH/GSSG) ratios. In conclusion, postovulatory oocyte aging could be effectively inhibited by appropriate N-acetyl-l-cysteine addition at low temperatures. In addition, a simple method for the temporary culture of mature oocytes was established.


Reproduction ◽  
2009 ◽  
Vol 137 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Jun-Zuo Wang ◽  
Hong-Shu Sui ◽  
De-Qiang Miao ◽  
Na Liu ◽  
Ping Zhou ◽  
...  

The objectives of this study were to investigate the effect of heat stress duringin vitromaturation on the developmental potential of mouse oocytes and to determine whether the deleterious effect was on the nuclear or cytoplasmic component. While rates of oocyte nuclear maturation (development to the metaphase II stage) did not differ from 37 to 40 °C, rates for blastocyst formation decreased significantly as maturation temperature increased from 38.5 to 39 °C. Chromosome spindle exchange showed that while blastocyst formation did not differ when spindles maturedin vivoorin vitroat 37, 40 or 40.7 °C were transplanted intoin vivomatured cytoplasts, no blastocyst formation was observed whenin vivospindles were transferred into the 40 °C cytoplasts. While oocytes reconstructed between 37 °C ooplasts and 37 or 40 °C karyoplasts developed into 4-cell embryos at a similar rate, no oocytes reconstituted between 40 °C ooplasts and 37 °C spindles developed to the 4-cell stage. Immunofluorescence microscopy revealed impaired migration of cortical granules and mitochondria in oocytes matured at 40 °C compared with oocytes matured at 37 °C. A decreased glutathione/GSSG ratio was also observed in oocytes matured at 40 °C. While spindle assembling was normal and no MAD2 was activated in oocytes matured at 37 or 40 °C, spindle assembling was affected and MAD2 was activated in some of the oocytes matured at 40.7 °C. It is concluded that 1) oocyte cytoplasmic maturation is more susceptible to heat stress than nuclear maturation, and 2) cytoplasmic rather than nuclear components determine the pre-implantation developmental capacity of an oocyte.


2020 ◽  
Vol 32 (5) ◽  
pp. 474
Author(s):  
Liga Wuri ◽  
Cansu Agca ◽  
Yuksel Agca

This study compared the morphometric, subcellular characteristics, in vitro fertilisation (IVF) and embryonic developmental potential of metaphase II (MII) mouse oocytes obtained from females superovulated with either anti-inhibin serum–human chorionic gonadotrophin (AIS-hCG) or pregnant mare serum gonadotrophin (PMSG)-hCG. The oocyte’s quantity, quality, zona pellucida (ZP) thickness, perivitelline space (PVS), diameter, microtubules, F-actin, cortical granules (CGs) and mitochondrial distribution were determined. Superovulation using AIS-hCG resulted in a higher numbers of oocyte/donor compared with PMSG-hCG (P=0.002). There was no difference in morphologically normal and abnormal oocytes between AIS-hCG and PMSG-hCG (P=0.425 and P=0.194, respectively). The morphometric measurements showed no difference in oocyte diameter between AIS-hCG and PMSG-hCG (P=0.289). However, the thickness of the ZP of oocytes from AIS-hCG females was decreased compared with PMSG-hCG (P<0.001). The PVS of oocytes from the AIS-hCG was larger than with PMSG-hCG (P<0.001). The microtubules of oocytes from both AIS-hCG and PMSG-hCG were normal, although there was an increased fluorescence intensity in the AIS-hCG oocytes (P<0.001). The F-actin and CGs distribution in oocytes from both AIS-hCG and PMSG-hCG were similar (P=0.330 and P=0.13, respectively). Although the oocytes from PMSG-hCG females had homogenously distributed mitochondria, AIS-hCG oocytes showed more peripheral distribution with no differences in fluorescence intensity (P=0.137). The blastocyst development rates after IVF with fresh sperm showed no difference between AIS-hCG and PMSG-hCG (P=0.235). These data suggested that AIS-hCG superovulation produces high numbers of morphologically normal oocytes that also possess normal subcellular structures, good morphological characteristics and had high invitro embryonic developmental potential.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dulama Richani ◽  
Cathy F. Lavea ◽  
Raji Kanakkaparambil ◽  
Angelique H. Riepsamen ◽  
Michael J. Bertoldo ◽  
...  

AbstractA follicular spike in cyclic AMP (cAMP) and its subsequent degradation to AMP promotes oocyte maturation and ovulation. In vitro matured (IVM) oocytes do not receive the cAMP increase that occurs in vivo, and artificial elevation of cAMP in IVM cumulus-oocyte complexes improves oocyte developmental potential. This study examined whether mouse oocytes can use the cAMP degradation product AMP to generate ATP via the adenosine salvage pathway, and examined whether pharmacological elevation of cAMP in IVM cumulus-oocyte complexes alters ATP levels. Oocytes cultured with isotopic 13C5-AMP dose-dependently produced 13C5-ATP, however total cellular ATP remained constant. Pharmacological elevation of cAMP using forskolin and IBMX prior to IVM decreased oocyte ATP and ATP:ADP ratio, and promoted activity of the energy regulator AMPK. Conversely, cumulus cells exhibited higher ATP and no change in AMPK. Culture of oocytes without their cumulus cells or inhibition of their gap-junctional communication yielded lower oocyte 13C5-ATP, indicating that cumulus cells facilitate ATP production via the adenosine salvage pathway. In conclusion, this study demonstrates that mouse oocytes can generate ATP from AMP via the adenosine salvage pathway, and cAMP elevation alters adenine nucleotide metabolism and may provide AMP for energy production via the adenosine salvage pathway during the energetically demanding process of meiotic maturation.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Maryam Mazhar ◽  
Ahmad Ud Din ◽  
Hamid Ali ◽  
Guoqiang Yang ◽  
Wei Ren ◽  
...  

AbstractLife is indeed continuously going through the irreversible and inevitable process of aging. The rate of aging process depends on various factors and varies individually. These factors include various environmental stimuli including exposure to toxic chemicals, psychological stress whereas suffering with various illnesses specially the chronic diseases serve as endogenous triggers. The basic underlying mechanism for all kinds of stresses is now known to be manifested as production of excessive ROS, exhaustion of ROS neutralizing antioxidant enzymes and proteins leading to imbalance in oxidation and antioxidant processes with subsequent oxidative stress induced inflammation affecting the cells, tissues, organs and the whole body. All these factors lead to conventional cell death either through necrosis, apoptosis, or autophagy. Currently, a newly identified mechanism of iron dependent regulated cell death called ferroptosis, is of special interest for its implication in pathogenesis of various diseases such as cardiovascular disease, neurological disorders, cancers, and various other age-related disorders (ARD). In ferroptosis, the cell death occur neither by conventional apoptosis, necrosis nor by autophagy, rather dysregulated iron in the cell mediates excessive lipid peroxidation of accumulated lethal lipids. It is not surprising to assume its role in aging as previous research have identified some solid cues on the subject. In this review, we will highlight the factual evidences to support the possible role and implication of ferroptosis in aging in order to declare the need to identify and explore the interventions to prevent excessive ferroptosis leading to accelerated aging and associated liabilities of aging.


Reproduction ◽  
2007 ◽  
Vol 133 (1) ◽  
pp. 219-230 ◽  
Author(s):  
Feikun Yang ◽  
Ru Hao ◽  
Barbara Kessler ◽  
Gottfried Brem ◽  
Eckhard Wolf ◽  
...  

The epigenetic status of a donor nucleus has an important effect on the developmental potential of embryos produced by somatic cell nuclear transfer (SCNT). In this study, we transferred cultured rabbit cumulus cells (RCC) and fetal fibroblasts (RFF) from genetically marked rabbits (Alicia/Basilea) into metaphase II oocytes and analyzed the levels of histone H3-lysine 9-lysine 14 acetylation (acH3K9/14) in donor cells and cloned embryos. We also assessed the correlation between the histone acetylation status of donor cells and cloned embryos and their developmental potential. To test whether alteration of the histone acetylation status affects development of cloned embryos, we treated donor cells with sodium butyrate (NaBu), a histone deacetylase inhibitor. Further, we tried to improve cloning efficiency by chimeric complementation of cloned embryos with blastomeres fromin vivofertilized or parthenogenetic embryos. The levels of acH3K9/14 were higher in RCCs than in RFFs (P<0.05). Although the type of donor cells did not affect development to blastocyst, after transfer into recipients, RCC cloned embryos induced a higher initial pregnancy rate as compared to RFF cloned embryos (40 vs 20%). However, almost all pregnancies with either type of cloned embryos were lost by the middle of gestation and only one fully developed, live RCC-derived rabbit was obtained. Treatment of RFFs with NaBu significantly increased the level of acH3K9/14 and the proportion of nuclear transfer embryos developing to blastocyst (49 vs 33% with non-treated RFF,P<0.05). The distribution of acH3K9/14 in either group of cloned embryos did not resemble that inin vivofertilized embryos suggesting that reprogramming of this epigenetic mark is aberrant in cloned rabbit embryos and cannot be corrected by treatment of donor cells with NaBu. Aggregation of embryos cloned from NaBu-treated RFFs with blastomeres fromin vivoderived embryos improved development to blastocyst, but no cloned offspring were obtained. Two live cloned rabbits were produced from this donor cell type only after aggregation of cloned embryos with a parthenogenetic blastomere. Our study demonstrates that the levels of histone acetylation in donor cells and cloned embryos correlate with their developmental potential and may be a useful epigenetic mark to predict efficiency of SCNT in rabbits.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Á Martíne. Moro ◽  
I Lamas-Toranzo ◽  
L González-Brusi ◽  
A Pérez-Gómez ◽  
P Bermejo-Álvarez

Abstract Study question Does cumulus cell mtDNA content correlate with oocyte developmental potential in the bovine model? Summary answer The relative amount of mtDNA content did not vary significantly in oocytes showing different developmental outcomes following IVF What is known already Cumulus cells are closely connected to the oocyte through transzonal projections, serving essential metabolic functions during folliculogenesis. These oocyte-supporting cells are removed and discarded prior to ICSI, thereby constituting an interesting biological material on which to perform molecular analysis aimed to predict oocyte developmental competence. Previous studies have positively associated oocytés mtDNA content with developmental potential in both animal models and women. However, it remains debatable whether mtDNA content in cumulus cells could be used as a proxy to infer oocyte developmental potential. Study design, size, duration Bovine cumulus cells were allocated into three groups according to the developmental potential of the oocyte: 1) oocytes developing to blastocysts following IVF (Bl+Cl+), 2) oocytes cleaving following IVF but arresting their development prior to the blastocyst stage (Bl-Cl+), and 3) oocytes not cleaving following IVF (Bl-Cl-). Relative mtDNA content was analysed in 40 samples/group, each composed by the cumulus cells from one cumulus-oocyte complex (COC). Participants/materials, setting, methods Bovine cumulus-oocyte complexes were obtained from slaughtered cattle and individually matured in vitro (IVM). Following IVM, cumulus cells were removed by hyaluronidase treatment, pelleted, snap frozen in liquid nitrogen and stored at –80 ºC until analysis. Cumulus-free oocytes were fertilized and cultured in vitro individually and development was recorded for each oocyte. Relative mtDNA abundance was determined by qPCR, amplifying a mtDNA sequence (COX1) and a chromosomal sequence (PPIA). Statistical differences were tested by ANOVA. Main results and the role of chance Relative mtDNA abundance did not differ significantly (ANOVA p &gt; 0.05) between the three groups exhibiting different developmental potential (1±0.06 vs. 1.19±0.05 vs. 1.11±0.05, for Bl+Cl+ vs. Bl-Cl+ vs. Bl-Cl-, mean±s.e.m.). Limitations, reasons for caution Experiments were conducted in the bovine model. Although bovine folliculogenesis, monoovulatory ovulation and early embryo development exhibit considerable similarities with that of humans, caution should be taken when extrapolating these data to humans. Wider implications of the findings: The use of molecular markers for oocyte developmental potential in cumulus cells could be used to enhance success rates following single-embryo transfer. Unfortunately, mtDNA in cumulus cells was not found to be a good proxy for oocyte quality. Trial registration number Not applicable


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