• Reproductive and Developmental Biology
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• 제32권2호
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• pp.135-140
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• 2008

Recent studies on nuclear transfer and induced pluripotent stem cells have demonstrated that differentiated somatic cells can be returned to the undifferentiated state by reversing their developmental process. These epigenetically reprogrammed somatic cells may again be differentiated into various cell types, and used for cell replacement therapies through autologous transplantation to treat many degenerative diseases. To date, however, reprogramming of somatic cells into undifferentiated cells has been extremely inefficient. Hence, reliable markers to identify the event of reprogramming would assist effective selection of reprogrammed cells. In this study, a transgene construct encoding enhanced green fluorescent protein (EGFP) under the regulation of human Oct4 promoter was developed as a reporter for the reprogramming of somatic cells. Microinjection of the transgene construct into pronuclei of fertilized mouse eggs resulted in the emission of green fluorescence, suggesting that the undifferentiated cytoplasmic environment provided by fertilized eggs induces the expression of EGFP. Next, the transgene construct was introduced into human embryonic fibroblasts, and the nuclei from these cells were transferred into enucleated porcine oocytes. Along with their in vitro development, nuclear transfer embryos emitted green fluorescence, suggesting the reprogramming of donor nuclei in nuclear transfer embryos. The results of the present study demonstrate that expression of the transgene under the regulation of human Oct4 promoter coincides with epigenetic reprogramming, and may be used as a convenient marker that non-invasively reflects reprogramming of somatic cells.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2004년도 제4회 발생공학 국제심포지움 및 학술대회
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• pp.88-88
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• 2004

• 한국동물생명공학회지
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• 제37권4호
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• pp.292-297
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• 2022

Direct injection of CRISPR/Cas9 into zygotes enables the production of genetically modified nonhuman primates (NHPs) essential for modeling specific human diseases, such as Usher syndrome, and for developing novel therapeutic strategies. Usher syndrome is a rare genetic disease that causes loss of hearing, retinal degeneration, and problems with balance, and is attributed to a mutation in MYO7A, a gene that encodes an uncommon myosin motor protein expressed in the inner ear and retinal photoreceptors. To produce an Usher syndrome type 1B (USH1B) rhesus macaque model, we disrupted the MYO7A gene in developing zygotes. Identification of appropriately edited MYO7A embryos for knockout embryo transfer requires sequence analysis of material recovered from a trophectoderm (TE) cell biopsy. However, the TE biopsy procedure is labor intensive and could adversely impact embryo development. Recent studies have reported using cell-free DNA (cfDNA) from embryo culture media to detect aneuploid embryos in human in vitro fertilization (IVF) clinics. The cfDNA is released from the embryo during cell division or cell death, suggesting that cfDNA may be a viable resource for sequence analysis. Moreover, cfDNA collection is not invasive to the embryo and does not require special tools or expertise. We hypothesized that selection of appropriate edited embryos could be performed by analyzing cfDNA for MYO7A editing in embryo culture medium, and that this method would be advantageous for the subsequent generation of genetically modified NHPs. The purpose of this experiment is to determine whether cfDNA can be used to identify the target gene mutation of CRISPR/Cas9 injected embryos. In this study, we were able to obtain and utilize cfDNA to confirm the mutagenesis of MYO7A, but the method will require further optimization to obtain better accuracy before it can replace the TE biopsy approach.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 1996년도 추계 학술대회 및 정기총회
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• pp.46.2-47
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• 1996

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2004년도 제47차 추계학술대회
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• pp.103-103
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• 2004

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2006년도 제51차 추계학술대회
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• pp.161-161
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• 2006

• Clinical and Experimental Reproductive Medicine
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• 제27권4호
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• pp.367-372
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• 2000

Objective: This study was performed to evaluate whether vitrification method could be used for the cryopreservation of human blastocysts derived from IVF program. Methods: Surplus embryos were obtained from consented IVF patients. Controlled ovarian hyperstimulation was done with midluteal GnRH agonist, gonadotropin and hCG. After oocyte retrieval and insemination, fresh embryo transfer was done at $4{\sim}8$ cell stage. The surplus embryos after ET were cultured in blastocyst medium up to 6 days after oocyte retrieval. Obtained blastocysts were cryopreserved with our vitrification method. Blastocysts were exposed to 1.5 Methylene glycol (EG) in phosphate buffered saline (PBS) for 2.5 minutes, followed by 5.5 M EG plus 1 M sucrose for 20 seconds. Then 1 to 3 blastocysts were mounted on electron microscope (EM) grid and the grid was plunged into liquid nitrogen for storage. For thawing, blastocyst-containing EM grids were sequentially transferred in 1.0 M, 0.5 M, 0.25 M, 0.125 M and 0 M sucrose solution at the intervals of2.5 minutes. And blastocysts were cultured for about 6 hours and only re-expanded blastocysts were transferred to uterus of the patients on 4 to 5 days after ovulation in natural cycle or on 18 to 19 day of artificial cycle. Results: From Oct. 1998 to Jul. 1999, 34 patients were agreed to participate in this study. The mean age and duration of infertility of the patients were 31.6 years and 4.1 years, respectively. Among 34 cycles. replacements could be done in 20 cycles (58.8%). A total 93 blastocysts were thawed and 48 (51.6%) of them survived. Thirty-eight blastocysts, mean 1.9 embryos per patient, were transferred, resulting in 5 clinical pregnancies which consisted of 1 triplet, 2 sets of twins and 2 singleton pregnancies. The pregnancy rate per transfer was 25% and implantation rate was 23.6%. Five patients delivered 7 healthy babies including 2 sets of twins at term. Conclusion: Successful pregnancies and deliveries were established after transfer of vitrified human blastocysts. Vitrification using ethylene glycol as cryoprotectant and electron microscope grid is a rapid and simple method that can be effectively applied for the cryopreservation of human blastocysts.

• 생명과학회지
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• 제16권4호
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• pp.566-570
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• 2006

현재, 유전자의 in vivo 기능을 연구하기 위해 가장 많이 이용되고 있는 transgenic mice를 생산하기 위한 기본적으로 이용되고 있는 방법이 one cell-stage embryo에 pronuclear microinjection (PMI)이다. 그러나, 이 PMI 후에 one cell-stage embryo들의 생존율은 현저히 감소 (65.4%)할 뿐만 아니라 PMI 후의 embryo의 출생률(26.4%)이 PMI 처리를 하지 않은 것 (41.9%) 보다 현저히 낮다. 더욱이, PMI 방법에 의해 태어난 transgenic founder들의 간 조직에 병리학적 변화가 14.8% 정도에 대해서 같은 한배의 새끼 non-transgenic founder들의 경우도 간 조직에 병리학적 변화가 14.3%로 나타났다. 결론적으로, 이 PMI 방법에 의한 염색체에 물리적 손상은 형질전환 마우스의 생산 및 표현형에 영향을 미치는 잠재적 요소로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권9호
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• pp.1152-1158
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• 2010

In differentiating human embryonic stem (d-hES) cells there are a number of types of cells which may secrete various nutrients and helpful materials for pre-implantation embryonic development. This study examined whether the d-hES could function as a feeder cell in vitro to support mouse embryonic development. By RT-PCR analysis, the d-hES cells revealed high expression of three germ-layered differentiation markers while having markedly reduced expression of stem cell markers. Also, in d-hES cells, LIF expression in embryo implantation-related material was confirmed at a similar level to undifferentiated ES cells. When mouse 2PN embryos were cultured in control M16 medium, co-culture control CR1aa medium or co-cultured with d-hES cells, their blastocyst development rate at embryonic day 4 (83.9%) were significantly better in the d-hES cell group than in the CR1aa group (66.0%), while not better than in the M16 group (90.7%)(p<0.05). However, at embryonic days 5 and 6, embryo hatching and hatched-out rates of the dhES cell group (53.6 and 48.2%, respectively) were superior to those of the M16 group (40.7 and 40.7%, respectively). At embryonic day 4, blastocysts of the d-hES cell group were transferred into pseudo-pregnant recipients, and pregnancy rate (75.0%) was very high compared to the other groups (M16, 57.1%; CR1aa, 37.5%). In addition, embryo implantation (55.9%) and live fetus rate (38.2%) of the d-hES cell group were also better than those of the other groups (M16, 36.7 and 18.3%, respectively; CR1aa, 23.2 and 8.7%, respectively). These results demonstrated that d-hES cells can be used as a feeder cell for enhancing in vitro and in vivo developmental potential of mouse pre-implantation embryos.

• Asian Pacific Journal of Cancer Prevention
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• 제15권18호
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• pp.7785-7792
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• 2014

Background: Valproic acid (VPA) is a potent anticancer and antiangiogenic agent. However, design and synthesis of chemical derivatives with improved antiangiogenic and anticancer activities are still necessary. In this study a library of novel derivatives of VPA was synthesized and tested. Methods: A human liver cancer cell line (HepG2) and a human normal embryonic kidney cell line (HEK 293) were exposed to various concentrations of VPA derivatives for 24 hours and cell viability was checked by MTT colorimetric assay. Anti-angiogenic properties were evaluated in transgenic zebrafish embryos. Results: N-valproylglycine derivatives suppressed survival almost 70% (p value 0.001) in HepG2 cells but only 10-12% in HEK 293 cells (p value 0.133). They also suppressed angiogenic blood vessel formation by 80% when used between $2-20{\mu}M$ in zebrafish embryos. Valproic acid hydrazides showed moderate level of anticancer activity by affecting 30-50% (p value 0.001) of cell viability in HepG2 cells and 8-10% in HEK293 cells (p value 0.034). Conclusion: The majority of compounds in this study showed potent and stronger antiangiogenic and anticancer activity than VPA. They proved selectively toxic to cancer cells and safer for normal cells. Moreover, these compounds inhibited developmental angiogenesis in zebrafish embryos. Based on the fact that liver is a highly vascularized organ, in case of liver carcinoma these compounds have the potential to target the pathological angiogenesis and could be an effective strategy to treat hepatocellular carcinoma.