scholarly journals Inverse relationship between autophagy and CTSK is related to bovine embryo quality

Reproduction ◽  
2020 ◽  
Vol 159 (6) ◽  
pp. 757-766
Author(s):  
Ahmed Z Balboula ◽  
Mansour Aboelenain ◽  
Jianye Li ◽  
Hanako Bai ◽  
Manabu Kawahara ◽  
...  

Improving the quality and the developmental competence of in vitro produced (IVP) embryos is an indispensable goal for assisted reproductive technology. Autophagy is a major protective mechanism for intracellular degradation of unnecessary cytoplasmic components. Autophagy ends by the fusion between autophagic vacuoles and lysosomes, allowing the degradation of the cargo by lysosomal enzymes, especially the cathepsins (CTSs). However, it is still unclear how autophagy and cathepsin K (CTSK) relate to embryo development. This study evaluated (1.) the activities of autophagy and CTSK in relation to bovine embryo quality and (2.) the effect of autophagy induction and/or CTSK inhibition on preimplantation embryo development and quality. We show here that good-quality embryos exhibited a greater autophagic activity and less CTSK activity compared to poor-quality embryos. Blastomeres of an individual embryo may vary in their quality. Good quality blastomeres showed an increased autophagic activity and decreased CTSK activity compared to poor-quality blastomeres within the same embryo at different developmental stages. Importantly, induction of autophagy and/or inhibition of CTSK improved the developmental rate (increased blastocyst and hatching rates) and the quality (increased total cell number and decreased the percentage of apoptotic cells) of IVP bovine embryos. These results demonstrate a promising approach to selectively isolate good-quality embryos and improve the efficiency of IVEP of cattle embryos.

Zygote ◽  
2021 ◽  
pp. 1-6
Author(s):  
Haixia Wang ◽  
Wenbin Cao ◽  
Huizhong Hu ◽  
Chenglong Zhou ◽  
Ziyi Wang ◽  
...  

Summary Many studies have focused on the optimization of the composition of embryo culture medium; however, there are few studies involving the effect of a culture medium changing procedure on the preimplantation development of embryos. In this study, three groups were designed: a non-renewal group, a renewal group and a half-renewal group. The levels of reactive oxygen species (ROS), apoptotic index, blastocyst ratio and blastocyst total cell number were analyzed in each group. The results showed that the ROS level and the apoptotic index of blastocyst in the non-renewal group were significantly higher than in the renewal group and the half-renewal group (P < 0.05). The blastocyst ratio and blastocyst total cell number were significantly higher in the half-renewal group than that in non-renewal group and the renewal group (P < 0.05). These results demonstrated that the procedure of changing the culture medium influenced ROS level, apoptotic index, blastocyst ratio and total cell number of blastocysts. In addition, the result suggested that changing the culture medium may lead to a loss of important regulatory factors for embryos, while not changing the culture medium may lead to the accumulation of toxic substances. Half-renewal can alleviate the defects of both no renewal and renewal, and benefit embryo development. This study will be of high value as a reference for the optimization of embryo culture in vitro, and is very significant for assisted reproduction.


1999 ◽  
Vol 1999 ◽  
pp. 2-2 ◽  
Author(s):  
M. Kuran ◽  
M.E. Staines ◽  
G.J. McCallum ◽  
A.G. Onal ◽  
T.G. McEvoy

Ovine embryos produced in synthetic oviduct fluid (SOF) medium or in coculture with granulosa cell monolayers supplemented with low (A; 120 μmol/l) and high (B; 190 μmol/l) ammonia-producing steer sera caused different degrees of fetal oversize (Carolan et al., 1998). The objective of the present study was to determine whether the effects on fetal growth induced by these sera were associated with alterations in early embryo development.A total of 911 bovine oocytes, used in 8 replicates to test the effect of three culture treatments on embryo development, were matured and fertilized in vitro (IVF= Day 0). Presumptive zygotes were allocated on Day 1 to culture in SOF supplemented with 10% v/v steer serum (SOF+A, n=308; SOF+B, n=302) or with amino acids plus 0.4% w/v crystalline BSA (SOFaaBSA, n=301). All cultures were in 20 μl droplets under oil (38.5°C; 5% CO2, 5% O2; 4 zygotes per drop) and droplets were renewed every 48 h. Cleavage rate was recorded on Day 3. On Days 7 and 8, blastocyst yields, grade 1 and 2 blastocysts, their cell numbers (by staining with Hoechst 33342) and their stage and diameter were determined.


Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2358
Author(s):  
Katarzyna Suwik ◽  
Emilia Sinderewicz ◽  
Dorota Boruszewska ◽  
Ilona Kowalczyk-Zięba ◽  
Joanna Staszkiewicz-Chodor ◽  
...  

Peroxisome proliferator-activated receptors (PPARs), a nuclear receptors for prostacyclin (PGI2) have been recognized as being essential for early embryo development. The objectives of the present study were to determine if the bovine early- and late-cleaved embryos in different stages of early development express PPARγ and PPARδ. Since embryo developmental competence depends on numerous biological factors, we evaluated if the expression of PPARγ and PPARδ correlate with selected embryo quality markers (SOX2, OCT4, PLAC8, IGF1R) in the in vitro produced embryos at different stages of their development. Developmental rates and embryo quality for early- and late-cleaved embryos were provided according to International Embryo Transfer Society (IETS; developmental stages: 2-, 4-, 16-cell embryo, morula, blastocyst (1—early, 2—developing, 3—expanded, 4—hatched); quality stages: A—high quality, B—moderate quality, C—low quality). We found that bovine embryos expressed mRNA of PPARδ and PPARγ at all stages of early development, independently of their quality. In addition, the expression of PPARδ and PPARγ correlated with the expression of quality markers in bovine blastocysts. Positive correlations were stronger and more frequent in the group of early-cleaved embryos, whereas the negative correlations were typical for the group of late-cleaved embryos. Obtained results and available literature reports may indicate the participation of PGI2, via PPARδ and PPARγ, in the processes related to the early embryo development, through the participation of this factor in the modulation of blastocyst hatching, implantation, and post-implantation development.


Reproduction ◽  
2009 ◽  
Vol 138 (3) ◽  
pp. 507-517 ◽  
Author(s):  
M Clemente ◽  
J de La Fuente ◽  
T Fair ◽  
A Al Naib ◽  
A Gutierrez-Adan ◽  
...  

The steroid hormone progesterone (P4) plays a key role in the reproductive events associated with pregnancy establishment and maintenance. High concentrations of circulating P4 in the immediate post-conception period have been associated with an advancement of conceptus elongation, an associated increase in interferon-τ production and higher pregnancy rates in cattle. Using in vitro and in vivo models and ∼8500 bovine oocytes across six experiments, the aim of this study was to establish the route through which P4 affects bovine embryo development in vitro and in vivo. mRNA for P4 receptors was present at all stages of embryo development raising the possibility of a direct effect of P4 on the embryo. Exposure to P4 in vitro in the absence or presence of oviduct epithelial cells did not affect the proportion of embryos developing to the blastocyst stage, blastocyst cell number or the relative abundance of selected transcripts in the blastocyst. Furthermore, exposure to P4 in vitro did not affect post-hatching elongation of the embryo following transfer to synchronized recipients and recovery on Day 14. By contrast, transfer of in vitro derived blastocysts to a uterine environment previously primed by elevated P4 resulted in a fourfold increase in conceptus length on Day 14. These data provide clear evidence to support the hypothesis that P4-induced changes in the uterine environment are responsible for the advancement in conceptus elongation reported previously in cattle and that, interestingly, the embryo does not need to be present during the period of high P4 in order to exhibit advanced elongation.


2017 ◽  
Vol 29 (4) ◽  
pp. 805 ◽  
Author(s):  
Luis B. Ferré ◽  
Yanina Bogliotti ◽  
James L. Chitwood ◽  
Cristóbal Fresno ◽  
Hugo H. Ortega ◽  
...  

The aim of the present study was to evaluate the effects of sperm motility enhancers and different IVF times on cleavage, polyspermy, blastocyst formation, embryo quality and hatching ability. In Experiment 1, sex-sorted X chromosome-bearing Bos taurus spermatozoa were incubated for 30 min before 18 h fertilisation with hyperactivating factors, namely 10 mM caffeine (CA), 5 mM theophylline (TH), 10 mM caffeine and 5 mM theophylline (CA + TH); and untreated spermatozoa (control). In Experiment 2, matured B. taurus oocytes were fertilised using a short (8 h) or standard (18 h) fertilisation length, comparing two different fertilisation media, namely synthetic oviducal fluid (SOF) fertilisation medium (SOF-FERT) and M199 fertilisation medium (M199-FERT). Cleavage and blastocyst formation rates were significantly higher in the CA + TH group (77% and 27%, respectively) compared with the control group (71% and 21%, respectively). Cleavage rates and blastocyst formation were significantly lower for the shortest fertilisation time (8 h) in M199-FERT medium (42% and 12%, respectively). The SOF-FERT medium with an 8 h fertilisation time resulted in the highest cleavage rates and blastocyst formation (74% and 29%, respectively). The SOF-FERT medium produced the highest embryo quality (50% Grade 1) and hatching rate (66%). Motility enhancers did not affect polyspermy rates, whereas polyspermy was affected when fertilisation length was extended from 8 h (3%) to 18 h (9%) and in M199-FERT (14%) compared with SOF-FERT (6%). We conclude that adding the motility enhancers CA and TH to sex sorted spermatozoa and Tyrode’s albumin lactate pyruvate (TALP)-Sperm can improve cleavage and embryo development rates without increasing polyspermy. In addition, shortening the oocyte–sperm coincubation time (8 h) resulted in similar overall embryo performance rates compared with the prolonged (18 h) interval.


2010 ◽  
Vol 22 (3) ◽  
pp. 564 ◽  
Author(s):  
Dessie Salilew-Wondim ◽  
Micheal Hölker ◽  
Franca Rings ◽  
Chirawath Phatsara ◽  
Abdollah Mohammadi-Sangcheshmeh ◽  
...  

Baculoviral inhibitors of apoptosis repeat-containing 6 (BIRC6) is believed to inhibit apoptosis by targeting key cell-death proteins. To understand its involvement during bovine preimplantation embryo development, two consecutive experiments were conducted by targeted knockdown of its mRNA and protein using RNA interference. In Experiment 1, the effect of BIRC6 knockdown during the early stages of preimplantation embryo development was assessed by injecting zygotes with long double-stranded RNA (ldsRNA) and short hairpin RNA (shRNA) against BIRC6 mRNA followed by in vitro culturing until 96 h post insemination (hpi). The results showed that in RNA-injected zygote groups, reduced levels of BIRC6 mRNA and protein were accompanied by an increase (P < 0.05) in the proportion of 2- and 4-cell and uncleaved embryos and a corresponding decrease (P < 0.05) in the number of 8-cell embryos. In Experiment 2, the effect of BIRC6 knockdown on blastocyst formation, blastocyst total cell number and the extent of apoptosis was investigated. Consequently, zygotes injected with ldsRNA and shRNA resulted in lower (P < 0.05) blastocyst formation and total blastocyst cell number. Moreover, the apoptotic cell ratio, CASPASE 3 and 7 activity, BAX to BCL-2 ratio and levels of SMAC and CASPASE 9 were higher in blastocysts derived from the ldsRNA and shRNA groups, suggesting increased apoptosis in those blastocysts. The results of this study reveal the importance of BIRC6 expression for embryo survival during bovine preimplantation embryo development. However, whether BIRC6 is essential for implantation and fetal development during bovine pregnancy needs further research.


Reproduction ◽  
2007 ◽  
Vol 133 (3) ◽  
pp. 597-608 ◽  
Author(s):  
Serge McGraw ◽  
Christian Vigneault ◽  
Marc-André Sirard

Distinct epigenetic modification events regulate gene expression and chromatin structure during the period between the immature oocyte and the blastocyst. Throughout this developmental period, important methylation fluctuations occur on genomic DNA and histones. Finding single orcombinations offactors, which are at work during this period is essential to understand the entire epigenetic process. With this in mind, we assessed the precise temporal expression profile, during preimplantation embryo development, of 15 key regulators involved in RNA, DNA or histone methylation, chromatin modification or silencing and transcription regulation. To achieve this, real-time RT-PCR was used to quantify the mRNA levels of ATF7IP, DMAP1, EHMT1, EHMT2, HELLS, JARID1A, JARID1B, JMJD1A, JMJD2A, LSD1, MeCP2, METTL3, PRMT2, PRMT5 and RCOR2, in the oocyte and throughout in vitro bovine embryo development. Our results demonstrate that all the 15 key regulators were present to different degrees in the developmental stages tested, and they can be divided into three different groups depending on their respective mRNA profile.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2313
Author(s):  
Alan D. Ealy ◽  
Savannah L. Speckhart ◽  
Lydia K. Wooldridge

The term “embryokine” has been used to denote molecules produced by the endometrium, oviduct, or by embryo itself that will influence embryo development. Several cytokines have been identified as embryokines in cattle and other mammals. This review will describe how these cytokines function as embryokines, with special emphasis being placed on their actions on in vitro produced (IVP) bovine embryos. Embryokines are being explored for their ability to overcome the poor development rates of IVP embryos and to limit post-transfer pregnancy retention efficiencies that exist in IVP embryos. This review will focus on describing two of the best-characterized cytokines, colony-stimulating factor 2 and interleukin 6, for their ability to modify bovine embryo quality and confirmation, promote normal fetal development, and generate healthy calves. Additional cytokines will also be discussed for their potential to serve as embryokines.


2015 ◽  
Vol 27 (1) ◽  
pp. 156
Author(s):  
J. De Bie ◽  
E. Merckx ◽  
S. Andries ◽  
I. Immig ◽  
P. E. J. Bols ◽  
...  

Elevated serum NEFA concentrations, typically present in negative energy balance (NEB) cows, are known to compromise bovine in vitro oocyte and embryo quality and developmental competence. These observations seem to be associated with oxidative stress. Therefore, antioxidant supplementation such as β-carotene (bC) can be a promising solution to ameliorate embryo quality and survival. However, little is known about the possible neutralizing effect of bC on NEB-compromised embryos. Accordingly, we hypothesise that bC can overcome the potential negative effects of metabolic conditions associated with NEB on embryo development. To investigate this we aimed to evaluate the effect of serum from bC-supplemented positive energy balance (PEB) or NEB cows on embryonic developmental competence. A total of 5 nonlactating Holstein-Friesian cows were subjected to 4 consecutive dietary treatments, 28 days each: 1) 1.2 × maintenance (M) (= PEB–bC), 2) 1.2 × M with daily 2000 mg of bC (Rovimix 10% bC, DSM) (= PEB+bC), 3) 0.6 × M + bC (= NEB+bC), and 4) after a 6 week acclimatization period 0.6 × M (= NEB–bC). Serum was collected 72 h after ovulation, pooled per dietary treatment, and heat inactivated during 30 min at 56°C. In total 1404 bovine slaughterhouse grade 1 cumulus-oocyte complexes were serum-free matured (4 repeats), routinely fertilized, and cultivated for 6.7 days with the addition of 10% serum of the 4 different treatments. Cleavage (48 h post-insemination), blastocyst rates (7.7 days post-insemination), and the rates of blastocysts from cleaved zygotes were calculated. Developmental competence data were compared between the 4 treatments using a binary logistic regression model taking replicate, treatment, and the interaction of both factors into account. The NEFA and bC data were analysed using a paired-samples t-test (IBM SPSS Statistics 20). Bonferroni correction was applied. Serum NEFA concentrations were significantly elevated in NEB compared to PEB (0.36 ± 0.18 mM v. 0.21 ± 0.11 mM; P = 0.011). β-Carotene supplementation drastically increased bC concentrations in serum in NEB (0.44 ± 0.18 μg mL–1 v. 3.28 ± 0.78 μg mL–1; P < 0.001) as well as in PEB (1.02 ± 0.91 μg mL–1 v. 3.04 ± 1.28 μg mL–1; P < 0.001). Unexpectedly no significant differences were found on cleavage rates (on average 81%), subsequent development until blastocyst stage (on average 29%), or blastocyst rates from cleaved zygotes (on average 36%). Briefly, our model was not able to indicate any negative effect of NEB serum on in vitro embryo development compared with PEB, and hence no extra beneficial effects of bC could be observed on the outcome. In conclusion, these data show that more research is needed to optimize this model to investigate the effect of specific dietary strategies on pre-implantation embryo quality.


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