357 CALCIUM RELEASE INDUCED BY THIMEROSAL AND INOSITOL 1,4,5-TRIPHOSPHATE IN HEAT-SHOCKED PORCINE OOCYTES

2007 ◽  
Vol 19 (1) ◽  
pp. 294
Author(s):  
J.-K. Tseng ◽  
P.-C. Tang ◽  
J.-C. Ju

Elevated ambient temperature has been known to be deleterious to the developmental competence of mammalian oocytes and embryos, although the mechanism is still unclear. The objective of this study was to determine the effect of heat shock (HS) on the alteration of intracellular calcium concentrations ([Ca2+]i) of matured pig oocytes by two different calcium releasing agents. Porcine cumulus–oocyte complexes were aspirated from the follicles (3–6 mm) and subjected to standard in vitro maturation procedure for 42 h. Matured oocytes were then randomly allocated to different heat treatments at 41.5°C for 0 (Control, C0h), 1 (HS1h), 2 (HS2h), or 4 h (HS4h). An additional control group was cultured for 4 h without heat shock (C4h). Oocytes were incubated with 2 µM fura-2 acetoxymethyl ester (AM) and 0.02% pluronic F-127 in Ca2+-free PBS (40 min) following heat shock, and then washed with Ca2+-free PBS (30 min) for detection of [Ca2+]i. Fluorescent images were captured with alternative excitation wavelengths at 340/380 nm by a rotating chopper disk equipped with an Axon imaging system. Data from both experiments were analyzed by ANOVA using the General Linear Model (GLM) of the SAS (SAS Institute, Inc., Cary, NC, USA). In Experiment 1, matured oocytes were activated by 200 mM thimerosal (10 min) following heat treatment. The maximal [Ca2+]i in the HS2h group was the highest among all treatment groups. The lowest maximal peak of [Ca2+]i was observed in the HS4h group, but it was still higher than that in the C4h group (P < 0.05). The total amount of Ca2+ release represented by the total area of the peaks in C4h was lower than in any other groups except HS4h (P < 0.05). In Experiment 2, each matured oocyte was injected with approximately 10 pL of inositol 1,4,5-triphosphate (IP3, 0.5 mM); the Ca2+ transient was recorded as described in the previous experiment. The maximal value of [Ca2+]i in the C4h group was still the lowest among the heat-shocked and C0h groups (P < 0.05). The total Ca2+ release in the HS2h group was the highest among all treatment groups, but only significantly higher than the HS1h and C4h groups (P < 0.05). A similar pattern of Ca2+ release in HS-oocytes was induced by thimerosal and IP3 stimulations. These results indicate that Ca2+ releasing capacity of matured pig oocytes is enhanced by a shorter duration of heat shock, but declines after prolonged exposure of heat shock and/or in vitro culture. The differential Ca2+ releasing capacity of heat-shocked oocytes prior to fertilization revealed physiological changes of pig oocytes after heat shock. This finding provides further insight for the low fertilization and developmental competence that occurs in farm species during hot seasons.

Zygote ◽  
2020 ◽  
pp. 1-6
Author(s):  
Ji-Eun Park ◽  
Sang-Hee Lee ◽  
Yong Hwangbo ◽  
Choon-Keun Park

Summary The aim of the present study was to investigate the effects of porcine follicular fluid (pFF) from large-sized (LFF; >8 mm in diameter) and medium-sized (MFF; 3–6 mm in diameter) follicles on the maturation and developmental competence of porcine oocytes. Cumulus–oocyte complexes (COCs) were collected from follicles 3–6 mm in diameter. The collected COCs were incubated for 22 h with LFF or MFF (in vitro maturation (IVM)-I stage) and were incubated subsequently for 22 h with LFF or MFF (IVM-II stage). Cumulus expansion was confirmed after the IVM-I stage and nuclear maturation was evaluated after the IVM-II stage. Intracellular glutathione (GSH) and reactive oxygen species (ROS) levels were measured and embryonic development was evaluated. Relative cumulus expansion and GSH levels were higher in the LFF group compared with in the MFF group after the IVM-I stage (P < 0.05). After the IVM-II stage, the numbers of oocytes in metaphase-II were increased in the LFF group and GSH content was higher in all of the LFF treatment groups compared with in the MFF treatment groups during both IVM stages (P < 0.05). ROS levels were reduced by LFF treatment regardless of IVM stage (P < 0.05). Blastocyst formation and the total numbers of cells in blastocysts were increased in all LFF treatment groups compared with the control group (P < 0.05). These results suggested that pFF from large follicles at the IVM stage could improve nucleic and cytoplasmic maturation status and further embryonic development through reducing ROS levels and enhancing responsiveness to gonadotropins.


2011 ◽  
Vol 23 (7) ◽  
pp. 876 ◽  
Author(s):  
Dorit Kalo ◽  
Zvi Roth

Programmed cell death via the sphingomyelin pathway has been suggested to underlie heat-shock disturbance of oocyte developmental competence. A series of experiments were performed to characterise the role of the sphingolipid ceramide in heat-shock-induced apoptosis, and to determine whether ceramide formation can be regulated. Bovine cumulus–oocyte complexes (COCs) were aspirated from ovaries collected in the cold season (November–April), in vitro-matured, fertilised and cultured for 8 days. Exposure of COCs to heat shock (41°C) during maturation reduced cleavage rate and blastocyst formation relative to the control group (38.5°C). Annexin-V binding (V-FITC assay), which is associated with the early apoptotic event of membrane phosphatidylserine turnover, was higher in oocytes exposed to short-term versus long-term heat shock, suggesting that heat-shock-induced apoptosis involves membrane alterations. Similar to heat exposure, oocyte maturation with C2-ceramide had a dose-dependent deleterious effect on the first cleavages and subsequent embryonic development in association with increased annexin-V binding. Blocking endogenous ceramide generation with fumonisin B1, a specific inhibitor of dihydroceramide synthase (i.e. de novo formation), moderated, to some extent, the effects of heat shock on oocyte developmental competence, suggesting that ceramide plays an important role in heat-shock-induced apoptosis.


2005 ◽  
Vol 17 (2) ◽  
pp. 211
Author(s):  
J.-K. Tseng ◽  
P.-C. Tang ◽  
J.-C. Ju

Oocytes are susceptible to heat shock (HS) during the maturation process. It has been demonstrated that HS induces apoptosis and/or the expression of HS protein 70 (hsp 70) in in vitro-produced oocytes and embryos. The objectives of this study were to analyze the effects of HS on the development and apoptosis of pig oocytes and embryos. Porcine ovaries were collected from a local slaughterhouse and the cumulus-oocyte complexes (COCs) were aspirated from follicles 3–6 mm in diameter and subjected to standard in vitro maturation procedures at 39°C for 42 h. The in vitro matured oocytes were then randomly allocated to different HS treatments at 41.5°C for 0 (control, C0h), 1 (HS1h), 2 (HS2h), or 4 h (HS4h). An additional control group of oocytes was cultured for 4 h without HS (C4h). Data were analyzed by chi-square test. In Experiment 1, anti-hsp 70 (SPA-810AP, Stressgen, San Diego, CA, USA) and Western blotting were used to examine the expression of hsp 70. Results indicated that no significant difference of hsp 70 expression in metaphase II porcine oocytes occurred between controls and HS groups (P > 0.05, 7 replicates). In Experiment 2, apoptosis of metaphase II oocytes after HS was identified by annexin V-FITC (Sigma, St. Louis, MO, USA) staining and TUNEL (Roche, Indianapolis, IN, USA). No significant apoptotic signal was detected in the HS groups compared to the controls. The intensity of annexin V staining was not affected by HS, but it increased with the time of culture (P < 0.05, n = 24–37). In Experiment 3, the apoptotic rate and developmental competence of the HS-oocytes were evaluated by TUNEL assay (n = 123–137, 4 replicates). Parthenogenetic activation (n = 123–137) was performed by an electric pulse (2.2 kV cm−1) combined with 6-dimethyaminopurine treatment (6-DMAP, 2.5 μM, 4 h, Sigma). The cleavage rates in HS2h (43 ± 29%) and HS4h (35 ± 28%) decreased (P < 0.05) compared to those in C0h (62 ± 12%) and C4h (66 ± 8%). In addition, the blastocyst formation rates and total cell numbers reduced (P < 0.05) after 2 h (11 ± 10%, 20 ± 16) and 4 h (11 ± 8%, 19 ± 8) of HS treatments compared to those in C0h (23 ± 14%, 32 ± 22) and C4h (21 ± 11%, 27 ± 17), all respectively. The numbers of blastocysts with TUNEL-positive signals were not significantly different between the HS and control groups, but the signals increased (P < 0.05) before the 8-cell stage in HS groups (22–24%) compared to the C0h and C4h controls (16 and 11%), respectively. These results indicate that reduction in developmental competence of in vitro-matured pig oocytes after heat shock is not closely correlated to the expression of hsp 70 in the oocytes and to the apoptotic cell numbers in the blastocyst. Whether detection of apoptosis by TUNEL or annexin V-FITC in oocytes is a good indicator requires further investigation.


2012 ◽  
Vol 24 (1) ◽  
pp. 207
Author(s):  
Y. Jeon ◽  
S.-S. Kwak ◽  
S.-A. Jeong ◽  
R. Salehi ◽  
Y. H. Seong ◽  
...  

Trans-ε-viniferin is a naturally occurring polyphenol belonging to the stilbenoids family. Trans-ε-viniferin is isolated from Vitis amurensis, 1 of the most common wild grapes in Korea, Japan and China. We investigated the effects of trans-ε-viniferin on in vitro maturation (IVM) and developmental competence after IVF or parthenogenesis (PA). At the laboratory of Veterinary Pharmacology, College of Veterinary Medicine, Chungbuk National University, trans-ε-viniferin was purified from the leaves and stems of Vitis amurensis. Data were analyzed with SPSS 17.0 using Duncan's multiple range test. First, in total, 594 cumulus–oocyte complexes (COC) were used for the evaluation of nuclear maturation. The COC were matured in TCM-199 medium supplemented with various concentrations of trans-ε-viniferin (0, 0.1, 0.5, 1.0 and 5.0 μM) with 10% porcine follicular fluid, 10 IU mL–1 of eCG and 10 IU mL–1 of hCG. After 22 h in maturation culture, the COC were cultured in hormone-free medium supplemented with various concentrations of trans-ε-viniferin for an additional 22 h and then nuclear maturation was evaluated. Second, in total, 300 matured oocytes were used to examine the effects of different trans-ε-viniferin concentrations (0, 0.5 and 5.0 μM) on porcine oocyte intracellular glutathione (GSH) and reactive oxygen species (ROS) levels. Lastly, the developmental competence of oocytes matured with different concentrations of trans-ε-viniferin (0, 0.5 and 5.0 μM) was evaluated after IVF or PA. In total, 711 embryos were evaluated. As results, we observed that trans-ε-viniferin treatment during IVM did not improve the nuclear maturation of oocytes in any group (84.2, 86.6, 85.5, 83.3 and 79.2%, respectively), but significantly increased (P < 0.05) intracellular GSH levels in the 0.5 μM group (0 μM vs 0.5 μM; 14.6 vs 16.8 pmol oocyte–1) and reduced ROS levels (0 μM vs 0.5 μM and 50 μM; 174.6 vs 25.7 and 23.8 pixel oocyte–1). Oocytes treated with trans-ε-viniferin during IVM did not have significantly different cleavage rates or blastocyst formation rates after IVF, but total cell numbers were significantly higher (P < 0.05) in the 0.5 and 5.0 μM treatment groups (53.6 ± 4.0 and 47.9 ± 3.1) compared to the control group (36.4 ± 2.2). The PA embryos showed similar results; there were no significant differences in cleavage rates and blastocyst formation rates, but the total cell number significantly increased in the 0.5 and 5.0 μM treatment groups (59.6 ± 4.2 and 60.8 ± 4.6) compared to the control group (43.1 ± 2.1). In conclusion, these results indicate that trans-ε-viniferin treatment during porcine IVM increased total cell number of blastocysts, possibly through increasing intracellular GSH synthesis and reducing ROS levels. This work was supported by a grant from the Korea institute of Planning & Evaluation for Technology in Food, Agriculture, Forestry & Fisheries, Republic of Korea.


Reproduction ◽  
2013 ◽  
Vol 146 (4) ◽  
pp. 407-417 ◽  
Author(s):  
A Z Balboula ◽  
K Yamanaka ◽  
M Sakatani ◽  
M Kawahara ◽  
A O Hegab ◽  
...  

Cathepsin B was found to be correlated inversely with the quality of bovine oocytes and embryos. The aims of this study were to evaluate i) the relationship between heat shock during in vitro maturation (IVM) of bovine cumulus–oocyte complexes (COCs) and cathepsin B activity in relation to apoptosis and ii) the effect of supplementation of cathepsin B inhibitor (E-64) during IVM of heat-shocked COCs on embryonic development. After IVM at 38.5 °C for 22 h (control group) or at 38.5 °C for 5 h followed by 41 °C for 17 h (heat shock group) either with or without 1 μM E-64, activities and protein expression of cathepsin B and caspase 3 were evaluated as well as TUNEL staining. After IVF, developmental rate, total cell number, and the percentage of apoptotic cells in blastocysts were evaluated on day 8 (day 0, IVF day). Heat-shocked IVM COCs showed significantly high activities and expressions of both cathepsin B, and caspase 3 accompanied by a significant increase in number of TUNEL-positive cells. Addition of E-64 significantly decreased the activities of cathepsin B and caspase 3, and TUNEL-positive cells in heat-shocked IVM COCs. Moreover, addition of 1 μM E-64 during IVM under heat shock conditions significantly improved both developmental competence and quality of the produced embryos. These results indicate that heat shock induction of cathepsin B is associated with apoptosis of COCs, and inhibition of cathepsin B activity can improve the developmental competence of heat-shocked COCs during IVM.


1990 ◽  
Vol 18 (3) ◽  
pp. 169-185 ◽  
Author(s):  
Peter G. AuBuchon ◽  
Karen S. Calhoun

The present study examined the effects of therapist presence and the addition of relaxation training on the efficacy and generalizability of in vivo exposure procedures in the treatment of multiply-phobic individuals. Thirty-two individuals who were severely phobic of at least two objects/situations were assigned to one of three treatment groups or a waiting list control group, but received treatment for only one phobia. The Exposure Alone group received prolonged exposure to a phobic stimulus while alone in a room with that stimulus. The Exposure + Relaxation group were also exposed to a phobic stimulus but had received additional training in a relaxation technique. Subjects in the Exposure + Therapist group were accompanied by a nonanxious/nonavoiding “therapist” during exposure sessions. All treatment groups improved significantly, but the Exposure + Therapist group demonstrated significantly greater extinction of fear responses related to the treated phobias than the other groups. The Exposure + Relaxation group demonstrated the greatest generalization of treatment effects to untreated phobias. Clinical and theoretical implications are discussed.


Author(s):  
A. O. Olayanju ◽  
N. I. Kyesmen ◽  
R. B. Jacob ◽  
T. D. Adeniyi ◽  
S. S. Enitan ◽  
...  

Some plants used in the management of sickle cell disease (SCD) have been shown to increase gelling time of sickle cell blood and inhibits sickling in vitro, reversal of sickling, inhibiting osmotically induced haemolysis of erythrocytes, membrane stabilization. Plants such as Sorghum bicolar, Phyllanthus amarus, U. afzelii, Securidaca longipedunculata, Momordica charantia, Dalium guineense have been found to exhibit anti-sickling properties. The polyherbal combination of these drugs was used in this study for the investigation of the effects of anti-sickling polyherbal mixture on haematological indices in rabbits. Sixty (60) New Zealand rabbits weighing 1200g ±200g, conducted in duplicate and designated experiment X (normal rabbits) and Y (anaemia induced using Cadmium 2mg/kg +10 mg/Kg body weight phenylhydrazine for 15 days). Both groups were further subdivided into four groups (A-D) with 5 animals each, administered saline substitute, different grades of polyherbal mixtures for 8 weeks. Blood sample (2mls) was collected into Ethylene Diamine Tetra Acetic Acid (EDTA) bottles for full blood count. The results in the experiment (X) showed significant increase in WBC (103/μl) count across the groups (B=8.15±0.33; C=9.3±0.74; D=9.8±0.59) compared to the control group (A=7.25±0.44) (p<0.05). RBC (106/μl) count showed insignificant increase in group B (5.1±0.20) and C (5.6±0.450), decrease level in D (4.4±0.26) compared to control A (4.8±0.29) (p<0.05). Hb(g/dl) and HCT (%) showed similar pattern with insignificant increased levels across all treatment groups (B=14.8±0.59, 43.4±1.74; C=15.5±0.78, 45.8±3.; D=14.2±0.85, 43.7±2.62) compared to control A (13.6±0.68; 41.5±2.49) respectively. Platelets showed significant increase in group B and C (286±17.16 and 286±17.16) compared to control A (244±9.76) with significant decrease in group D (226±18.08) (p<0.05). In experiment (Y), WBC count showed significant increase across all treatment groups (B= 6.4±0.26 C= 6.8±0.54 D =10.6±0.64) compared to control (A= 4±0.24) (p<0.05). RBC (106/μl) count in control A gave (2.5±0.15), insignificant increase in B (3.1±0.12) with significant increase in group C (3.5±0.28) and insignificant decrease in D (2.2±0.13) (p<0.05). Higher level of Hb (g/dL) was seen in group B and C (B= 8.4±0.34; C= 9.1±0.46), while D (7.7±0.46) had a slightly elevated value compared to the control A (7.1±0.36) (p<0.05). HCT (%) showed significant increase across the groups (B=26±1.04; C=28±2.24; D=24±1.44) (p<0.05) compared to control A (18±1.08). Red cell indices showed some degree of derangement across the study groups. Findings in this study suggest that polyherbal mixture have a positive effect on the haemoglobin, red blood cells, packed cell volume and white blood cell count of the rabbits in a dose dependent manner.


Zygote ◽  
2020 ◽  
pp. 1-5
Author(s):  
Li Ang ◽  
Cao Haixia ◽  
Li Hongxia ◽  
Li Ruijiao ◽  
Guo Xingping ◽  
...  

Summary The present study investigated the effects of c-type natriuretic peptide (CNP) on the development of murine preantral follicles during in vitro growth (IVG). Preantral follicles isolated from ovaries of Kunming mice were cultured in vitro. In the culture system, CNP was supplemented in the experimental groups and omitted in the control groups. In Experiment 1, CNP was only supplemented at the early stage and follicle development was evaluated. In Experiments 2 and 3, CNP was supplemented during the whole period of in vitro culture. In Experiment 2, follicle development and oocyte maturity were evaluated. In Experiment 3, follicle development and embryo cleavage after in vitro fertilization (IVF) were assessed. The results showed that in the control groups in all three experiments, granulosa cells migrated from within the follicle and the follicles could not reach the antral stage. In the experimental groups in all three experiments, no migration of granulosa cells was observed and follicle development was assessed as attaining the antral stage, which was significantly superior to that of the control group (P < 0.0001). Oocyte meiotic arrest was effectively maintained, hence giving good developmental competence. In conclusion, CNP supplementation in the culture system during IVG benefited the development of murine preantral follicles.


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.


2018 ◽  
Vol 30 (10) ◽  
pp. 1342 ◽  
Author(s):  
Zhao-Bo Luo ◽  
Long Jin ◽  
Qing Guo ◽  
Jun-Xia Wang ◽  
Xiao-Xu Xing ◽  
...  

Accumulating evidence suggests that aberrant epigenetic reprogramming and low pluripotency of donor nuclei lead to abnormal development of cloned embryos and underlie the inefficiency of mammalian somatic cell nuclear transfer (SCNT). The present study demonstrates that treatment with the small molecule RepSox alone upregulates the expression of pluripotency-related genes in porcine SCNT embryos. Treatment with the histone deacetylase inhibitor LBH589 significantly increased the blastocyst formation rate, whereas treatment with RepSox did not. Cotreatment with 12.5 μM RepSox and 50 nM LBH589 (RepSox + LBH589) for 24 h significantly increased the blastocyst formation rate compared with that of untreated embryos (26.9% vs 8.5% respectively; P < 0.05). Furthermore, the expression of pluripotency-related genes octamer-binding transcription factor 4 (NANOG) and SRY (sex determining region Y)-box 2 (SOX2) were found to significantly increased in the RepSox + LBH589 compared with control group at both the 4-cell and blastocyst stages. In particular, the expression of NANOG was 135-fold higher at the blastocyst stage in the RepSox + LBH589 group. Moreover, RepSox + LBH589 improved epigenetic reprogramming. In summary, RepSox + LBH589 increases the expression of developmentally important genes, optimises epigenetic reprogramming and improves the in vitro development of porcine SCNT embryos.


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