scholarly journals The HDAC Inhibitor LAQ824 Enhances Epigenetic Reprogramming and In Vitro Development of Porcine SCNT Embryos

2017 ◽  
Vol 41 (3) ◽  
pp. 1255-1266 ◽  
Author(s):  
Jun-Xue Jin ◽  
Sanghoon Lee ◽  
Anukul Taweechaipaisankul ◽  
Geon A. Kim ◽  
Byeong Chun Lee

Background/Aims: Hypoacetylation caused by aberrant epigenetic nuclear reprogramming results in low efficiency of mammalian somatic cell nuclear transfer (SCNT). Many epigenetic remodeling drugs have been used in attempts to improve in vitro development of porcine SCNT embryos. In this study, we examined the effects of LAQ824, a structurally novel histone acetylase inhibitor, on the nuclear reprogramming and in vitro development of porcine SCNT embryos. Methods: LAQ824 treatment was supplemented during the culture of SCNT embryos. The reprogramming levels were measured by immunofluorescence and quantified by image J software. Relative expression levels of 18 genes were analyzed by quantitative real-time PCR. Results: 100 nM LAQ824 treatment of post-activation SCNT embryos for 24 h significantly improved the subsequent blastocyst formation rate. The LAQ824 treatment enhanced histone 3 lysine 9 (H3K9) levels, histone 4 lysine 12 (H4K12) levels, and reduced global DNA methylation levels as well as anti-5-methylcytosine (5-mC) at the pseudo-pronuclear and 2-cell stages. Furthermore, LAQ824 treatment positively regulated the mRNA expression of genes for histone acetylation (HAT1, HDAC1, 2, 3, and 6), DNA methylation (DNMT1, 3a and 3b), development (Pou5f1, Nanog, Sox2, and GLUT1) and apoptosis (Bax, Bcl2, Caspase 3 and Bak) in blastocysts. Conclusion: Optimum exposure (100 nM for 24 h) to LAQ824 post-activation improved the in vitro development of porcine SCNT embryos by enhancing levels of H3K9 and H4K12, reducing 5-mC, and regulating gene expression.

2013 ◽  
Vol 25 (1) ◽  
pp. 174
Author(s):  
R. Olivera ◽  
C. Alvarez ◽  
I. Stumpo ◽  
G. Vichera

The time allowed for nuclear reprogramming is considered an essential factor for the efficiency of cloning and has not been evaluated in equine aggregated cloned embryos. The aim of our work was to assess the effect of different timing of activation stimulus after fusion of adult equine fibroblast cells to enucleated equine oocytes on embryo development and embryo quality. We processed a total of 1874 equine ovaries, recovering 3948 oocytes, of which 1914 (48.5%) had extruded the first polar body after 24 h of maturation. Oocyte collection, maturation, and the NT procedure were performed as described by Lagutina et al. (2007 Theriogenology 67, 90–98). Reconstructed oocytes (RO) were activated at 3 different times after cell fusion: (1) 1 h, (2) 1.5 h, and (3) 2 h. Activation was performed using 8.7 µM ionomycin for 4 min, followed by a 4-h culture in a combination of 1 mM DMAP and 5 mg mL–1 of cycloheximide. The RO were cultured in the well of the well system, aggregating 3 RO per well. The RO were cultured in DMEM-F12 with 5% fetal bovine serum (FBS) and antibiotics. Cleavage (48 h after activation), blastocyst, and expanded blastocyst rates (8–9 days) were assessed. In vitro development was compared using the chi-square test (P < 0.05). A total of 1608 RO were cultured. Cleavage was significantly lower in group 3 with respect to the other 2 groups [(1): 396/450, 88%; (2): 540/639, 84.5%; (3): 365/519, 70.3%]. There were no significant differences in blastocyst rates within the 3 groups considering the number of total RO [(1): 19/450, 4.2%; (2): 23/639, 3.6%; (3): 15/519, 2.9%] or aggregated RO per well [(1): 12.7%; (2): 10.8%; (3): 8.7%]. However, the rate of blastocyst expansion was higher (P < 0.05) in group 2 than in group 3 [(1): 17/19, 89.5%; (2): 23/23, 100%; (3): 11/15, 73.3%]. In conclusion, the timing of nuclear reprogramming did not affect blastocyst rates but affected cleavage rates and blastocyst quality. This indicates that 1 h before activation stimulus is enough for embryo development of equine aggregated cloned embryos.


2007 ◽  
Vol 19 (1) ◽  
pp. 262
Author(s):  
W. Fujii ◽  
H. Funahashi

If diploid zygotes constituted with a somatic and a maternal genome could successfully develop to term, a new reproductive method would be developed to produce animals. However, there appears to be little information on this subject. In the present study, in vitro early development of the constituted zygotes was examined. A cumulus cell was microinjected into a rat non-enucleated oocyte, the reconstructed oocyte was chemically activated, and the pronuclear formation and in vitro development of the embryo was observed. Prepubertal Wistar female rats (21–27 days old) were induced to superovulate with an IP injection of 15 IU of eCG, followed by 15 IU of hCG 48 h later. Cumulus cells were removed from oocytes by pipetting with 0.1% hyaluronidase. Experiment 1: The DNA content of cumulus cells for microinjection was evaluated by flow cytometry. Experiment 2: The optimal concentration of SrCl2 for activation of rat oocytes was examined. Experiment 3: Cumulus cells were injected into mature oocytes in BSA-free HEPES-buffered mKRB containing 0.1% polyvinyl alcohol (PVA) and cytochalasin B (5 �g mL-1), and were then chemically activated by treatment in Ca2+-free mKRB containing 5 mM SrCl2 for 20 min at 0 to 0.5 (A), 1 to 1.5 (B), or 3 to 3.5 h (C) after injection. Activated embryos were cultured in droplets of mKRB in an atmosphere of 5% CO2 in air at 37�C for 9 to 12 h. After being observed for pronuclear formation, the embryos were transferred into mR1ECM-PVA, and the cleavage and blastocyst formation rates were examined 24 and 120 h later, respectively. Results from 3 to 7 replicates were analyzed by ANOVA and Duncan's multiple range test. A total of 90.0 and 9.5% of cumulus cells derived from ovulated oocyte–cumulus complexes contained 2C and 4C DNA contents, respectively. Survival rates did not differ among oocytes stimulated with 0 to 5 mM SrCl2 (96.7–100%) but did differ between those stimulated with 1.25 and 10 mM SrCl2 (100 and 72.9%, respectively). Activation rates of oocytes increased at higher SrCl2 concentrations and were higher at 5 and 10 mM (92.6 and 98.5%, respectively) than at other concentrations. When cumulus-injected oocytes were activated after various periods after the injection, the incidences of pronuclear formation and cleavage did not differ among the periods (A: 95.0 and 81.3%; B: 85.6 and 85.0%; and C: 82.7 and 84.6%, respectively). Although a majority of the embryos developed to the 2- to 4-cell stages (78.7%; 152/208), the blastocyst formation rate was very low (0.8%; 2/208). In conclusion, rat non-enucleated oocytes injected with a cumulus cell can form pronuclei and cleave following chemical activation, but blastocyst formation of the embryos is very limited.


2017 ◽  
Author(s):  
◽  
Bethany Rae Mordhorst

Gene edited pigs serve as excellent models for biomedicine and agriculture. Currently, the most efficient way to make a reliably-edited transgenic animal is through somatic cell nuclear transfer (SCNT) also known as cloning. This process involves using cells from a donor (which may have been gene edited) that are typically grown in culture and using their nuclear content to reconstruct a new zygote. To do this, the cell may be placed in the perivitelline space of an enucleated oocyte and activated artificially by a calcium-containing media and electrical pulse waves. While it is remarkable that this process works, it is highly inefficient. In pigs the success of transferred embryos becoming live born piglets is only 1-3%. The creation of more cloned pigs enables further study for the benefit of both A) biomedicine in the development of prognosis and treatments and B) agriculture, whether it be for disease resistance, feed efficiency, gas emissions, etc. Two decades of research has not drastically improved the cloning efficiency of most mammals. One of the main impediments to successful cloning is thought to be due to inefficient nuclear reprogramming and remodeling of the donor cell nucleus. In the following chapters we detail our efforts to improve nuclear reprogramming of porcine fetal fibroblasts by altering the metabolism to be more blastomere-like in nature. We used two methods to alter metabolism 1) pharmaceutical agents and 2) hypoxia. After treating donor cells both methods were used in nuclear transfer. Pharmaceutical agents did not improve in vitro development of gestational survival of clones. Hypoxia did improve in vitro development and we are currently awaiting results of gestation.


2015 ◽  
Vol 27 (1) ◽  
pp. 131 ◽  
Author(s):  
J. H. Galiguis ◽  
C. E. Pope ◽  
M. N. Biancardi ◽  
C. Dumas ◽  
G. Wang ◽  
...  

Vitrification remains a promising technique in the preservation of valuable genetic material; however, in the cat, success has varied. Live kittens have been produced from embryos vitrified at early cleavage stages, but phenotypic abnormalities in some kittens suggest possible epigenetic effects of the vitrification process. It has been reported that cryopreservation alters epigenetic events in somatic donor cells, which indirectly influences physical status of cloned offspring. However, extending post-warming in vitro culture of donor cells corrects these epigenetic modifications, resulting in normal embryos/clones. Accordingly, in the present study, vitrification was performed at the pronuclear stage to lengthen pretransfer culture time, and vitrified cat zygotes were assessed by analysing (1) histone acetylation/methylation, (2) global DNA methylation, (3) pluripotent gene expression, (4) in vitro development, and () in vivo viability. In vivo matured/IVF oocytes were vitrified in 15% dimethyl sulfoxide, 15% ethylene glycol, and 0.5 M sucrose at 16 h post-insemination (PI). After warming in 1.0 M sucrose at 38°C, embryos were fixed at 18 h or 40 h PI, and the nuclear intensity of either acetyl/dimethyl-H3K9 or 5-methylcytosine was determined by immunofluorescence. Results showed that at 18 h PI, mean H3K9ac intensity of vitrified embryos (11.8; n = 6) was higher than that of corresponding nonvitrified (fresh) controls (4.5; n = 6) and the fresh (3.2; n = 11) and vitrified (0.6; n = 7) 40-h groups (2-way ANOVA; P < 0.05). H3K9me2 in the fresh (36.9) and vitrified (32.5) 18-h embryos was similar but increased relative to both fresh (10.7) and vitrified (9.2) 40-h groups (P < 0.05). Mean DNA methylation (5MeC) in the fresh (31.6; n = 1) and vitrified (24.7; n = 3) 18-h groups was similar to that of the fresh 40-h group (19.8; n = 4) but higher than that of the vitrified 40-h group (15.0; n = 5; P < 0.05). To assess expression of POU5F1 and Nanog, qRT-PCR was performed on Day 8 blastocysts. Relative to controls (n = 9), mean POU5F1 and Nanog levels in vitrified blastocysts (n = 24) were 1.38- and 1.98-fold higher, respectively (one-way ANOVA; P > 0.05). In terms of in vitro development, Day 2 cleavage of vitrified zygotes (59%; n = 508) was similar to that of controls (66%; n = 340), but Day 8 blastocyst formation was reduced (9 v. 31%; t-test; P < 0.05). In vivo viability was assessed by oviducal transfer of 41 Day 1 embryos into 2 recipients. One pregnancy was established (50%), with 3 live kittens weighing 70, 79, and 131 g delivered without assistance on Day 65 of gestation. The 2 smaller kittens died within a few hours of birth, with the smallest exhibiting an umbilical hernia and organ exteriorization. The third kitten developed into a normal, healthy adult. In summary, mean H3K9me2, 5MeC, and POU5F1/Nanog expression of vitrified zygotes was similar to corresponding controls. H3K9ac increased at 18h PI as a result of vitrification, but was reduced after culture to 40 h PI. Although vitrified zygotes cleaved in vitro at rates similar to controls, blastocyst development was reduced. In vivo viability was demonstrated; however, postnatal survival of kittens produced was low.


PLoS ONE ◽  
2011 ◽  
Vol 6 (8) ◽  
pp. e23805 ◽  
Author(s):  
Jianmin Su ◽  
Yongsheng Wang ◽  
Yanyan Li ◽  
Ruizhe Li ◽  
Qian Li ◽  
...  

2013 ◽  
Vol 25 (1) ◽  
pp. 169 ◽  
Author(s):  
J. T. Kang ◽  
J. Y. Choi ◽  
S. J. Park ◽  
S. J. Kim ◽  
J. H. Moon ◽  
...  

Despite great advances in the field of cloning techniques, the efficiency of production of cloning animals is very low. Maybe the poor outcome of somatic cell nuclear transfer (SCNT) is thought to be a consequence of incomplete reprogramming of the donor cell or cloned embryos. The objective of this study was to investigate the effects of treatment with S-adenosylhomocysteine (SAH), the reversible nontoxic inhibitor of DNA methyltransferases (DNMT), on porcine female fibroblast donor cells and in vitro development of cloned embryos. We hypothesized that SAH targeting DNA methylation could alter chromatin configuration and turn it more amenable to reprogramming. Thus, the female fibroblast donor cells were cultured in media containing respective concentrations of SAH [0 (control), 0.1, 0.5, and 1 mM) for 2 passages. One-way ANOVA was used to determine significant differences in the data and a Tukey test was done to determine statistical differences among groups. Compared with nontreated controls, the cells treated with SAH, especially 1 mM, revealed significantly (P < 0.05) reduced global DNA methylation, proved by commercial kit and immunocytochemistry analysis, and elevation of transcript levels for X chromosome-linked genes (XIST and HPRT), estimated by real-time PCR analysis compared with the control group. It was suggested that treatment with SAH in female cells could make cells into more valuable donor cells for cloning. In another trial, cloned embryos using normal donor cells were cultured in media containing 1 mM SAH for 0 (control), 12, and 24 h after activation on different time interval of DNMT inhibition, transferred to PZM5 media, and subsequently cultured for 7 days. Treatment with SAH for 12 h resulted in 13.0 ± 1.9% blastocyst production, which was significantly greater than cloned embryos treated with SAH for 24 h (11.2 ± 2.1%) and control cloned embryos (9.1 ± 1.2%). It was suggested that the appropriate DNMT inhibition might have an important role in in vitro development of porcine SCNT, and improving effects on developmental competency of cloned embryos. We concluded that SAH induced global DNA demethylation that partially reactivated the X chromosome and that a hypomethylated genome may facilitate the nuclear reprogramming process. This study was supported by IPET (no. 311011-05-1-SB010), MKE (no. 10033839-2012-21), Institute for Veterinary Science, the BK21 program, and TS Corporation.


2011 ◽  
Vol 13 (5) ◽  
pp. 431-439 ◽  
Author(s):  
Li-Jun Wang ◽  
Hui Zhang ◽  
Yong-Sheng Wang ◽  
Wen-Bing Xu ◽  
Xian-Rong Xiong ◽  
...  

2011 ◽  
Vol 23 (1) ◽  
pp. 173
Author(s):  
L. C. Sui ◽  
W. Wang ◽  
Y. S. Li ◽  
Y. L. Zhang ◽  
S. F. Ji ◽  
...  

Recently, it has been reported that a new activation method, brief exposure to cycloheximide before electrical activation, could increase development rates and reduce cell death. In our study, we allocated reconstructed SCNT embryos into 3 groups: electrical activation followed by exposure to cycloheximide (10 μg mL–1) for 4 h (ELE+CHX); exposure to cycloheximide (10 μg mL–1) for 10 min followed by electrical activation (CHX+ELE); and electrical pulse treatment alone (ELE). We found the CHX+ELE (10 min) group had a similar blastocyst formation rate and total blastocyst number with the ELE+CHX (4 h) group, and both groups could increase in vitro development compared with the ELE group. Trichostatin A (TSA), an inhibitor of histone deacetylase, has been reported to potentially enhance cloning efficiency. We examine the effect of TSA on nuclear transfer embryos produced by the CHX+ELE activation method. The reconstructed embryos were treated with 50 nM TSA for 0 and 36 h. We found that 50 nM TSA for 36 h after activation had an increased blastocyst rate compared with the control (15.35 v. 8.84%; P < 0.05), but there was no difference in cleavage rate or in total blastocyst numbers. Our data demonstrate that TSA treatment could significantly improve pig nuclear transfer embryos produced by a new activation method. S.L.C., W.W. equal contribution; Corresponding author ZH. X.R., ZH. Y.H.; Supported by NSFC (30700574), 863 (2008AA101003).


Sign in / Sign up

Export Citation Format

Share Document