Juvenile and adult immature and in vitro matured ovine oocytes evaluated in relation to membrane electrical properties, calcium stores, IP3 sensitivity and apoptosis occurrence in cumulus cells

2008 ◽  
Vol 75 (12) ◽  
pp. 1752-1760 ◽  
Author(s):  
R. Boni ◽  
N. Cocchia ◽  
F. Silvestre ◽  
G. Tortora ◽  
R. Lorizio ◽  
...  
2005 ◽  
Vol 17 (2) ◽  
pp. 290 ◽  
Author(s):  
R. Boni ◽  
N. Cocchia ◽  
F. Silvestre ◽  
G. Tortora ◽  
R. Lorizio ◽  
...  

The low developmental efficiency recorded in juvenile oocytes represents, besides its technological relevance, an opportunity for increasing the knowledge of mechanisms regulating developmental competence in the oocytes. To analyze the biological reasons that make an adult oocyte different from a juvenile one, we monitored membrane electrical properties, i.e. resting potential, steady-state conductance and calcium currents, and calcium stores in these two oocyte types both at immature (GV) stage and after in vitro maturation (MII). Ovaries of cycling ewes and 40-day-old lambs were collected at abattoir and transported at 30°C. Cumulus-oocyte complexes (COC) were recovered by mincing. In vitro maturation was carried out in TCM199 supplemented with 10% fetal calf serum, 10 IU/mL of LH, 0.1 IU/mL of FSH, and 1 mg/mN of 17β-estradiol at 39.0°C in 5% CO2 for 24 h. Zona pellucida of immature and in vitro-matured oocytes was removed after incubation for 1–1.5 min in 0.5% (w/v) protease solution. Zona-free oocytes were placed in Ham F10 at 38.5°C and voltage clamped by standard techniques (Tosti et al. 2002 Reproduction 124, 835–846). After obtaining a giga-seal, the patch was ruptured. The permeability of the plasma membrane was verified by applying depolarizing and hyperpolarizing voltage steps of 10 mV and 500 ms before and at the peak current to generate the voltage-dependent currents. The voltage clamp was set at −80 and −30 mV to differentiate the Ca2+ current components, i.e. L-type Ca2+ channels. For intracellular calcium determinations, oocytes were placed in Ham F10 and injected with the 0.5 mM calcium green dextran (Mr 10,000). Ca2+ stores were evoked by the addition of 5 μM Ca2+ ionophore, monitored using a computer-controlled photo-multiplier system, and measured as relative fluorescence units (RFU) by normalizing fluorescence against baseline fluorescence. In lamb and ewe, differences in electrical features and calcium dynamics between GV (n = 36 and 17) and MII (n = 42 and 32) oocytes were tested by ANOVA and expressed as mean ± SEM. Resting potential was higher at MII than GV stages (−15.2 ± 0.9 vs. −12.1 ± 1.1 mV, respectively; P < 0.02) but it did not differ between animal age. GV stage and ewe showed either a higher steady-state conductance (25.4 ± 0.2 vs. 11.7 ± 0.2 nS and 21.7 ± 0.2 vs. 15.4 ± 0.2 nS, respectively; P < 0.01) or L-type Ca2+ channels (9.7 ± 1.4 vs. 2.7 ± 1.3 pA and 9.2 ± 1.5 vs. 3.2 ± 1.1 pA, respectively; P < 0.01). No differences were found between resting potential peaks yielded after Ca2+ ionophore exposure but a higher ion activation current was found in lamb oocytes (489 ± 56 vs. 300 ± 73 pA; P < 0.05). Ca2+ stores did not differ between animal age but they were larger at MII than at GV stage (0.70 ± 0.07 vs. 0.44 ± 0.07 RFU; P < 0.01). These results supply further information on both reproductive biology in ovine species and the physiology of oocytes collected from juvenile and adult individuals. This work was supported by Italian Ministry of University and Research (MIUR) COFIN 2002 Project.


Reproduction ◽  
2000 ◽  
pp. 127-135 ◽  
Author(s):  
W Bone ◽  
NG Jones ◽  
G Kamp ◽  
CH Yeung ◽  
TG Cooper

The effects of the male antifertility agent ornidazole on glycolysis as a prerequisite for fertilization were investigated in rats. Antifertility doses of ornidazole inhibited glycolysis within mature spermatozoa as determined from the lack of glucose utilization, reduced acidosis under anaerobic conditions and reduced glycolytic enzyme activity. As a consequence, cauda epididymidal spermatozoa from ornidazole-fed rats were unable to fertilize rat oocytes in vitro, with or without cumulus cells, which was not due to transfer of an inhibitor in epididymal fluid with the spermatozoa. Under IVF conditions, binding to the zona pellucida was reduced in spermatozoa from ornidazole-fed males and the spermatozoa did not undergo a change in swimming pattern, which was observed in controls. The block to fertilization could be explained by the disruption of glycolysis-dependent events, since reduced binding to the zona pellucida and a lack of kinematic changes were demonstrated by control spermatozoa in glucose-free media in the presence of respiratory substrates. The importance of glycolysis for binding to, and penetration of, the zona pellucida, and hyperactivation in rats is discussed in relation to the glycolytic production of ATP in the principal piece in which local deprivation of energy may explain the reduced force of spermatozoa from ornidazole-fed males.


Author(s):  
Er-Meng Gao ◽  
Bongkoch Turathum ◽  
Ling Wang ◽  
Di Zhang ◽  
Yu-Bing Liu ◽  
...  

AbstractThis study evaluated the differences in metabolites between cumulus cells (CCs) and mural granulosa cells (MGCs) from human preovulatory follicles to understand the mechanism of oocyte maturation involving CCs and MGCs. CCs and MGCs were collected from women who were undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment. The differences in morphology were determined by immunofluorescence. The metabolomics of CCs and MGCs was measured by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) followed by quantitative polymerase chain reaction (qPCR) and western blot analysis to further confirm the genes and proteins involved in oocyte maturation. CCs and MGCs were cultured for 48 h in vitro, and the medium was collected for detection of hormone levels. There were minor morphological differences between CCs and MGCs. LC-MS/MS analysis showed that there were differences in 101 metabolites between CCs and MGCs: 7 metabolites were upregulated in CCs, and 94 metabolites were upregulated in MGCs. The metabolites related to cholesterol transport and estradiol production were enriched in CCs, while metabolites related to antiapoptosis were enriched in MGCs. The expression of genes and proteins involved in cholesterol transport (ABCA1, LDLR, and SCARB1) and estradiol production (SULT2B1 and CYP19A1) was significantly higher in CCs, and the expression of genes and proteins involved in antiapoptosis (CRLS1, LPCAT3, and PLA2G4A) was significantly higher in MGCs. The level of estrogen in CCs was significantly higher than that in MGCs, while the progesterone level showed no significant differences. There are differences between the metabolomes of CCs and MGCs. These differences may be involved in the regulation of oocyte maturation.


2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 2-3
Author(s):  
Theisy P Acosta Pérez

Abstract α-tocopherol is known to be a powerful antioxidant, in this regard, it was added to bovine oocyte in vitro maturation media to evaluate its effect on oocyte maturation. Oocytes (n = 624) aspirated from ovaries of slaughtered cows were classified by quality and divided in four categories according to cytoplasm appearance and cumulus cells layers. Oocytes were washed in TCM-199 supplemented with fetal bovine serum (FBS) and FSH, then distributed in maturation media (TCM-199 supplemented with FBS, FSH and gentamicin). Three experimental groups of α-tocopherol (50, 100 and 200 mM) and a control group without α-tocopherol were used. Maturation was carried 22 h at 38.5°C in a 5% CO2 atmosphere. Oocytes were examined to determine cumulus expansion as categorical data (expansion or no expansion), as well as cumulus expansion Index (CEI). For CEI determination oocytes were graded 0 to 4, being 0 those with null expansion and 4 those with a noticeable cell expansion, then the number of oocytes were multiplied by the grade given and a sum of the totals was obtained, the new total was divided by the total of oocytes in the group and the result obtained corresponded to the CEI of the group. Results were analyzed with Chi Square test (for maturation rates) and an ANOVA (for the CEI) using the SAS system, data are presented as mean ± standard error. There was no statistical difference between control and α-tocopherol groups (P &gt;0.05). Numerically, the control group showed a higher maturation rate (100%) and obtained a higher CEI (2.44±0.20), followed by the 50 mM group (98.16%; 2.39±0.13), the groups 200 mM (97.40%; 2.00±0.14) and 100 mM (96.25%; 2.06±0.24) were the lowest. The addition of the minimum concentration (50 mM) of α-tocopherol to the maturation media could improve maturation rates without exposing oocytes to toxic effects.


Author(s):  
Kiptiyah Kiptiyah ◽  
Widodo Widodo ◽  
Gatot Ciptadi ◽  
Aulanni’am Aulanni’Am ◽  
Mohammad A. Widodo ◽  
...  

AbstractBackgroundWe investigated whether 10-gingerol is able to induce oxidative stress in cumulus cells.MethodsFor the in-vitro research, we used a cumulus cell culture in M199, containing 10-gingerol in various concentrations (0, 12, 16, and 20 µM), and detected oxidative stress through superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentrations, with incubation periods of 24, 48, 72, and 96 h. The obtained results were confirmed by in-silico studies.ResultsThe in-vitro data revealed that SOD activity and MDA concentration increased with increasing incubation periods: SOD activity at 0 µM (1.39 ± 0.24i), 12 µM (16.42 ± 0.35ab), 16 µM (17.28 ± 0.55ab), 20 µM (17.81 ± 0.12a), with a contribution of 71.1%. MDA concentration at 0 µM (17.82 ± 1.39 l), 12 µM (72.99 ± 0.31c), 16 µM (79.77 ± 4.19b), 20 µM (85.07 ± 2.57a), with a contribution of 73.1%. Based on this, the in-silico data uncovered that 10˗gingerol induces oxidative stress in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT˗1.Conclusions10-gingerol induces oxidative stress in cumulus cells through enhancing SOD activity and MDA concentration by inhibiting HTR1A functions and inactivating GSK3B and AKT˗1.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1794
Author(s):  
Konstantina Stamperna ◽  
Themistoklis Giannoulis ◽  
Eleni Dovolou ◽  
Maria Kalemkeridou ◽  
Ioannis Nanas ◽  
...  

Heat shock protein 70 (HSP70) is a chaperon that stabilizes unfolded or partially folded proteins, preventing inappropriate inter- and intramolecular interactions. Here, we examined the developmental competence of in vitro matured oocytes exposed to heat stress with or without HSP70. Bovine oocytes were matured for 24 h at 39 °C without (group C39) or with HSP70 (group H39) and at 41 °C for the first 6 h, followed by 16 h at 39 °C with (group H41) or without HSP70 (group C41). After insemination, zygotes were cultured for 9 days at 39 °C. Cleavage and embryo yield were assessed 48 h post insemination and on days 7, 8, 9, respectively. Gene expression was assessed by RT-PCR in oocytes, cumulus cells and blastocysts. In C41, blastocysts formation rate was lower than in C39 and on day 9 it was lower than in H41. In oocytes, HSP70 enhanced the expression of three HSP genes regardless of incubation temperature. HSP70 at 39 °C led to tight coordination of gene expression in oocytes and blastocysts, but not in cumulus cells. Our results imply that HSP70, by preventing apoptosis, supporting signal transduction, and increasing antioxidant protection of the embryo, protects heat stressed maturing bovine oocyte and restores its developmental competence.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 478
Author(s):  
Martina Cotena ◽  
Mélanie Auffan ◽  
Virginie Tassistro ◽  
Noémie Resseguier ◽  
Jérôme Rose ◽  
...  

Benzo(a)pyrene (BaP) is a recognized reprotoxic compound and the most widely investigated polycyclic aromatic hydrocarbon in ambient air; it is widespread by the incomplete combustion of fossil fuels along with cerium dioxide nanomaterials (CeO2 NMs), which are used in nano-based diesel additives to decrease the emission of toxic compounds and to increase fuel economy. The toxicity of CeO2 NMs on reproductive organs and cells has also been shown. However, the effect of the combined interactions of BaP and CeO2 NMs on reproduction has not been investigated. Herein, human and rat gametes were exposed in vitro to combusted CeO2 NMs or BaP or CeO2 NMs and BaP in combination. CeO2 NMs were burned at 850 °C prior to mimicking their release after combustion in a diesel engine. We demonstrated significantly higher amounts of DNA damage after exposure to combusted CeO2 NMs (1 µg·L−1) or BaP (1.13 µmol·L−1) in all cell types considered compared to unexposed cells. Co-exposure to the CeO2 NMs-BaP mixture induced additive DNA damage in sperm and cumulus cells, whereas no additive effect was observed in rat oocytes. This result could be related to the structural protection of the oocyte by cumulus cells and to the oocyte’s efficient system to repair DNA damage compared to that of cumulus and sperm cells.


Zygote ◽  
2021 ◽  
pp. 1-5
Author(s):  
Shiori Ashibe ◽  
Kanade Irisawa ◽  
Ken Yokawa ◽  
Yoshikazu Nagao

Summary Hyaluronidase is widely used in animal and human assisted reproductive technologies (ARTs) to remove cumulus cells around oocytes. However, adverse effects of hyaluronidase treatment, such as increased rates of degeneration and parthenogenesis, have been found after treatment of human and mouse oocytes. Currently, the mechanism(s) of the detrimental effects are unclear. The present study was initiated to identify the mechanism of adverse responses to hyaluronidase treatment in bovine oocytes and early embryos. Cumulus cells were removed from cumulus–oocyte complexes (COCs) with or without hyaluronidase and the oocytes were subjected to intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF). Significantly lower rates of blastocyst formation were obtained in the hyaluronidase treatment group after ICSI (22.4%) and IVF (21.2%) compared with the non-hyaluronidase control groups: 36.1% after ICSI and 30.4% after IVF. Next, we examined the effect of hyaluronidase on parthenogenetic development rates and on the cytoplasmic levels of free calcium ions (Ca2+), reactive oxygen species (ROS) and reduced glutathione (GSH). No differences in parthenogenesis rates were found between treated and untreated groups. Ca2+ levels in oocytes from the hyaluronidase treatment group indicated using mean fluorescence intensity were significantly higher (68.8 ± 5.3) compared with in the control group (45.0 ± 2.5). No differences were found in the levels of ROS or GSH between the treated and untreated groups. We conclude that hyaluronidase might trigger an increase in Ca2+ levels in oocytes, resulting in a decreased potential for normal embryonic development.


Sign in / Sign up

Export Citation Format

Share Document