184 EFFECT OF HISTONE DEACETYLASE INHIBITOR ON DEVELOPMENT OF EMBRYOS DERIVED FROM HEAT-SHOCKED BOVINE OOCYTES

2017 ◽  
Vol 29 (1) ◽  
pp. 200
Author(s):  
V. R. A. Mendes ◽  
R. B. S. Dias ◽  
J. F. S. Souza ◽  
E. D. Souza ◽  
C. C. R. Quintao ◽  
...  

Heat shock affects the oocyte developmental competence and embryonic gene expression. We found that the chromatin organisation of embryos derived from heat-shocked oocytes can also be affected (Camargo et al. 2015 Reprod. Fert. Dev. 27, 132). This study aimed to evaluate whether Scriptaid, a histone deacetylase inhibitor able to modulate the chromatin structure, could influence the development of embryos derived from heat-shocked oocytes. Bovine oocytes were in vitro-matured under conventional temperature (38.5°C) for 24 h (non-heat-shock; NHS group) or under 41.5°C for 12 h followed by 38.5°C for 12 h (heat-shock; HS group). In vitro fertilization was performed under 38.5°C with 5% CO2 in air for 20 h. Right after the end of fertilization the presumptive zygotes from the NHS or HS groups were denuded and randomly exposed to 500 nM Scriptaid for 0, 12, or 24 h, comprising 6 treatments as followa: NHS-0 h (NHS without Scriptaid, n = 185); NHS-12 h (NHS plus Scriptaid for 12 h, n = 178); NHS-24 h (NHS plus Scriptaid for 24 h, n = 177); HS-0 h (HS without Scriptaid, n = 187); HS-12 h (HS plus Scriptaid for 12 h, n = 180); and HS-24 h (HS plus Scriptaid for 24 h, n = 183). After Scriptaid exposure, zygotes were cultured in CR2aa plus 2.5% FCS at 38.5°C with 5% CO2, 5% O2, and 90% N2. Cleavage rate was calculated on Day 2 (44 h post-fertilization) and blastocyst rates on Day 7 and 8 post-fertilization. Six replicates were carried out and data was analysed by logistic regression (Proc Logistic, SAS 9.2, SAS Institute Inc., Cary, NC). Significant data were interpreted as odd ratios considering the 95% confidence interval. Values are shown as mean ± standard error of the mean. There was no difference (P > 0.05) among NHS treatments (NHS-0 h, NHS-12 h, and NHS-24 h) as well as among HS treatments (HS-0 h, HS-12 h, and HS-24 h) for cleavage and blastocyst rates at Day 7. At Day 8, however, the blastocyst rate in the NHS group decreased (P < 0.05) as the time of zygote exposure to Scriptaid increased to 24 h (33.9 ± 2.8 and 24.2 ± 1.6% for NHS-0 h and NHS-24 h, respectively), whereas no difference (P > 0.05) was found in the HS group (20.7 ± 1.5, 21.2 ± 1.6, and 20.5 ± 2.4% for HS-0 h, HS-12 h, and HS-24 h, respectively). Comparison between NHS and HS treatments showed that cleavage and blastocyst rates at Day 7 and 8 of NHS-0 h (88.7 ± 2.8, 30.1 ± 1.5, and 33.9 ± 2.8%, respectively) were superior (P < 0.05) to HS-0 h (79.3 ± 3.2, 16.9 ± 1.0, and 20.7 ± 1.5%, respectively). Differences (P < 0.05) between NHS-12 h and HS-12 h on blastocyst rates at Day 7 (32.8 ± 3.8 v. 20.6 ± 1.7%, respectively) and at Day 8 (31.7 ± 2.7 v. 21.2 ± 1.6%, respectively) were also found. However, no difference (P > 0.05) between NHS-24 h and HS-24 h was found. We showed that Scriptaid for 24 h right after IVF has a negative impact on further development of zygotes derived from oocytes matured under conventional temperature (NHS group), in contrast to zygotes derived from oocytes matured under high temperature (HS group). We concluded that the effect of Scriptaid on embryo development is influenced by the temperature during oocyte maturation. Supported by FAPEMIG, CAPES, and CNPq.

2014 ◽  
Vol 26 (1) ◽  
pp. 197
Author(s):  
E. D. Souza ◽  
F. B. E. Paula ◽  
C. C. R. Quintao ◽  
J. H. M. Viana ◽  
L. T. Iguma ◽  
...  

The 90-kDa heat shock protein (HSP90) is a chaperone that is important for maintaing protein homeostasis under stress conditions. HSP90 seems also to be required for maturation of Xenopus oocytes (Fisher et al. 2000 EMBO J. 19, 1516) and first cleavage of mouse zygotes (Audouard et al. 2011 PloS One 6, e17109). This study aimed to evaluate the effect of inhibition of HSP90 by 17-(allylamino)-17-demethoxygeldanamycin (17AAG, Sigma St. Louis, MO, USA) during in vitro maturation (IVM) on bovine oocyte developmental competence. Immature cumulus–oocyte complexes (COC) were randomly allocated in 3 treatments during IVM: T0 (control; n = 240), no HSP90 inhibitor; T1: 2 μM HSP90 inhibitor (17AAG; n = 250) for the first 12 h of IVM; and T2: 2 μM HSP90 inhibitor (n = 188) for 24 h of IVM. In vitro maturation was performed in Nunc plates containing 400 μL of TCM-199 medium (Invitrogen, Carlsbad, CA, USA) supplemented with porcine FSH (Hertape Calier, Juatuba, Brazil) and 10% oestrus cow serum under 5% CO2, 95% humidity, and 38.5°C for 24 h. Oocytes were in vitro fertilized for 20 h and incubated under the same IVM conditions. Semen was processed by Percoll gradient (Nutricell, Campinas, Brazil) an IVF performed with 2 × 106 spermatozoa mL–1. Presumptive zygotes were completely denuded in a PBS solution with hyaluronidase and then cultured in wells with 500 μL of modified CR2aa medium supplemented with 2.5% fetal calf serum (Nutricell) in an incubator at 38.5°C under 5% CO2, 5% O2, 90% N2, and saturated humidity. Cleavage rate was evaluated 72 h post-fertilization and blastocyst rates were evaluated at Day 7 and Day 8. Data from 6 repetitions were analysed by generalized linear model procedure of SAS software (version 9.1; SAS Institute Inc., Cary, NC, USA), and means were compared by Student-Newman-Keuls test. Values are shown as mean ± s.e.m. There was a tendency (P = 0.08) for a lower cleavage rate in T2 (52.6 ± 5.8%) than in T0 (control; 74.2 ± 4.1%). Inhibition of HSP90 by 17AAG for 12 h and 24 h of IVM (T1 and T2, respectively) decreased blastocyst rates at Day 7 (20.4 ± 3.0% and 14.3 ± 2.6%, respectively; P < 0.01) and Day 8 (22.6 ± 4.1% and 16.9 ± 2.7%, respectively; P < 0.05) when compared with control (T0 = 31.8 ± 2.5% and 34.1 ± 2.9% for Day 7 and Day 8, respectively). In addition, the inhibition of HSP90 for 24 h decreased (P < 0.05) the proportion of hatched blastocysts at Day 8 (9.5 ± 5.0% for T2, respectively) when compared with control (T0 = 35.8 ± 3.9%), indicating a reduction on embryo quality. In conclusion, inhibition of HSP90 by 17AAG during IVM results in lower developmental competence, suggesting that this protein is also important for bovine oocytes. Further studies are required to investigate if the role of HSP90 on developmental competence of bovine oocyte is affected when under stress conditions. The authors acknowledge CNPq 473484/2011-0, FAPEMIG and FAPES for financial support.


2015 ◽  
Vol 27 (1) ◽  
pp. 235
Author(s):  
E. D. Souza ◽  
N. C. Rabelo ◽  
T. D. Araujo ◽  
C. M. Assunção ◽  
C. C. R. Quintão ◽  
...  

The heat shock protein 90kDa (HSP90) is a chaperone involved in protein homeostasis under normal and stress conditions. Its inhibition by 17-(allylamino)-17-demethoxygeldanamycin (17AAG, Sigma, St. Louis, MO, USA) for 12 or 24 h during in vitro maturation reduces the oocyte's ability to develop after in vitro fertilization (Souza et al. 2014 Reprod. Fert. Dev. 26, 197). This study aimed to evaluate the effect of treatment with 17AAG during the heat shock on oocyte developmental competence. Immature bovine COC were randomly allocated in 4 treatments during IVM: control = no heat shock or 17AAG; HS = heat shock (41.5°C) for the first 12 h of IVM; 17AAG = 2 µM 17AAG for the first 12 h of IVM; and 17AAG + HS = 2 µM 17AAG plus heat shock for the first 12 h of IVM. In vitro maturation was performed in Nunc plate containing 400 µL of TCM199 medium (Invitrogen, Carlsbad, CA, USA) supplemented with porcine FSH (Hertape Calier, Juatuba, Brazil) and 10% oestrus cow serum under 5% CO2 in air, 95% humidity, and 38.5°C for 24 h. Semen was processed by Percoll gradient (Nutricell, Campinas, Brazil) and oocytes were in vitro fertilized for 20 h with 2 × 106 spermatozoa mL–1 under the same IVM atmospheric conditions. Presumptive zygotes were completely denuded in a PBS solution with 0.1% hyaluronidase and then cultured in wells with 500 µL of modified CR2aa medium supplemented with 2.5% fetal calf serum (Nutricell) in an incubator at 38.5°C under 5% CO2, 5% O2, 90% N2, and saturated humidity. Cleavage rate was evaluated 72 h postfertilization and blastocyst rate was evaluated at Day 7 (D7) and 8 (D8). Data from 7 replicates were submitted to analysis of variance and means were compared by Student Newman Keul's test. There was no difference (P > 0.05) on cleavage rate among treatments. Heat shock or treatment with 17AAG, both for 12 h of IVM, decreased (P < 0.05) the blastocyst rate at D7 and D8 when compared to control but no significant difference between HS and 17AAG treatments was found (Table 1). However, the lowest (P < 0.05) blastocyst rate at D7 and D8 was achieved when oocytes were submitted simultaneously to 17AAG and heat shock for 12 h of IVM (17AAG + HS treatment, Table 1). In conclusion, the treatment with 17AAG during IVM worsens the deleterious effect of heat shock on oocyte developmental competence and suggests that HSP90 may also play role on cellular protection during heat shock in bovine oocytes. Table 1.Cleavage and blastocyst (Bl) rates at D7 and D8 for control, 17AAG, Heat Shock (HS), and 17AAG plus HS treatments Financial support comes from CNPq, FAPEMIG, and FAPES.


Zygote ◽  
2014 ◽  
Vol 23 (4) ◽  
pp. 514-524 ◽  
Author(s):  
Qi Meiyu ◽  
Di Liu ◽  
Zvi Roth

SummaryAn in vitro model of embryo production was used to examine the effects of insulin-like growth factor (IGF)-I on maturation and developmental competence of oocytes exposed to heat shock. Cumulus–oocyte complexes were matured at 38.5°C or exposed to acute heat shock (HS; 41.5°C), with or without 100 ng/ml IGF-I, for 22 h through in vitro maturation. The experimental groups were control (C), C + IGF-I, HS, and HS + IGF-I. Oocytes were fertilized at the end of maturation, and the proportion of cleaved embryos was recorded 44 h later. HS during maturation increased the proportion of TUNEL-positive oocytes (P < 0.05). HS did not have any effect on cortical granule translocation but impaired resumption of meiosis, expressed as a decreased proportion of oocytes with nuclei in metaphase I (P < 0.05) and metaphase II (MII; P < 0.05). HS decreased the proportion of oocytes that cleaved (P < 0.05), in particular those oocytes that further developed to 4-cell-stage embryos (P < 0.05). IGF-I alleviated, to some extent, the deleterious effects of HS on the oocytes as reflected by a reduced proportion of TUNEL-positive oocytes (P < 0.03). While not significant, IGF-I tended to increase the proportion of MII-stage oocytes (P < 0.08) and 4-cell-stage cleaved embryos (P < 0.06). Further examination is required to explore whether IGF-I also affects the developmental competence of oocytes exposed to HS.


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.


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