• Reproductive and Developmental Biology
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• v.38 no.4
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• pp.137-142
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• 2014

A tremendous increase in the human population has put poultry industry under an increased pressure to meet steep increase in the demand. Poultry is contributing 25% of the total world's meat production and lesser cost of investment per bird makes it more suitable for the further breeding programmes. Major poultry diseases frequently lead to cardiac damage and cause huge economic losses to poultry industry due to mortality. The in vitro embryonic stem cell (ESC) technology has a futuristic approach for homogeneous populace of differentiated cells, for their further transplantations. During in vitro conditions the differentiated cell populace can be used in grafting and transplantation processes to regenerate damaged tissues. Therefore, the current study targeted the use of spermatogonial stem cells (SSCs) in the poultry production system through cardiac regeneration. The current study will also open new boulevard for the similar kind of research in other livestock species for the management of heart diseases.

• Health Policy and Management
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• v.23 no.4
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• pp.314-325
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• 2013

Background: Stem cell research competition is accelerating globally since President Obama signed an executive order, repealing Bush-era policy that limited use of federal tax dollars for embryonic stem cell research. Methods: In this paper, we conducted a comparative analysis of stem cell research policy changes in three countries, including the Human Fertilisation Embryology Act (HFEA) of UK, executive order 13,505 (removing barriers to responsible scientific research involving human stem cells) of USA, and Bioethics and Safety Act of South Korea. Debates on stem cell research are based on conflicts of fundamental beliefs that exist in the supporting and opposing coalitions. We compared regional characteristics of the advocacy coalitions in three countries and presented various factors that might be related to the policy changes. Results: The UK government, parliament, and the HFEA have sought expert consultations and public opinions to establish guidelines. UK has made social consensus through continued discussion for a long time. US President's veto power was one strongest factors influencing policy. South Korean policy was influenced by public opinion and policy brokers. Also, South Korea has not made social consensus. UK had a strong leadership and strong adjustment of coalitions but US and South Korea had not. Dr. Hwang's scandal has had one of the greatest impacts on policy decision in South Korea. Conclusion: The power of public opinion was critical in all three countries. In particular, the influence of public opinion was noticeable in South Korea. Also it turned out that in US and South Korea, the presence of a policy broker who could pursue his or her goals was the most powerful factor among the advocacy coalition factors.

• Biomedical Science Letters
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• v.25 no.2
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• pp.177-184
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• 2019

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of Parkinson's disease (PD). LRRK2 contains a functional kinase and GTPase domains. A pathogenic G2019S mutation that is the most prevalent among the LRRK2 mutations and is also found in sporadic cases, increases its kinase activity. Therefore, identification of LRRK2 kinase substrates and the development of kinase inhibitors are under intensive investigation to find PD therapeutics. Several recent studies have suggested members of Rab proteins, a branch of the GTPase superfamily, as LRRK2 kinase substrates. Rab proteins are key regulators of cellular vesicle trafficking. Among more than 60 members of human Rab proteins, Rab3, Rab5, Rab8, Rab10, Rab12, Rab29, Rab35, and Rab43 have been identified as LRRK2 kinase substrates. However, most studies have used human embryonic kidney (HEK) 293T cells overexpressing LRRK2/Rab proteins or murine embryonic fibroblast (MEF) cells which are not relevant to PD, rather than neuronal cells. In this study, we tested whether Rab proteins are phosphorylated by LRRK2 in astroglia in addition to neurons. Among the various Rab substrates, we tested phosphorylation of Rab10, because of the commercial availability and credibility of the phospho-Rab10 (pRab10) antibody, in combination with a specific LRRK2 kinase inhibitor. Based on the results of specific LRRK2 kinase inhibitor treatment, we concluded that LRRK2 phosphorylates Rab10 in the tested brain cells such as primary neurons, astrocytes and BV2 microglial cells.

• BMB Reports
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• v.49 no.4
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• pp.197-198
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• 2016

Although three different research groups have reported successful derivations of human somatic cell nuclear transfer-derived embryonic stem cell (SCNT-ESC) lines using fetal, neonatal and adult fibroblasts, the extremely poor development of cloned embryos has hindered its potential applications in regenerative medicine. Recently, however, our group discovered that the severe methylation of lysine 9 in Histone H3 in a human somatic cell genome was a major SCNT reprogramming barrier, and the overexpression of KDM4A, a H3K9me3 demethylase, significantly improved the blastocyst formation of SCNT embryos. In particular, by applying this new approach, we were able to produce multiple SCNT-ES cell lines using oocytes obtained from donors whose eggs previously failed to develop to the blastocyst stage. Moreover, the success rate was closer to 25%, which is comparable to that of IVF embryos, so that our new human SCNT method seems to be a practical approach to establishing a pluripotent stem cell bank for the general public as well as for individual patients.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.123-129
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• 2011

The pig has been considered to serve as an appropriate model of human disease. Therefore, establishment of porcine embryonic stem cell lines is important. The purpose of the present study was to further work in this direction. We produced porcine parthenogenetic embryos, and separately aggregated two of each of two-cell ($2{\times}2$), four-cell ($2{\times}4$), and eight-cell ($2{\times}8$) embryos derived by parthenogenesis. After culture for 4 days, the developmental ability of the aggregates and total blastocyst cell numbers were evaluated. The percentage of blastocysts was significantly higher in both $2{\times}4$- and $2{\times}8$-aggregated embryos ($58.3{\pm}1.9%$ and $37.2{\pm}2.8%$, respectively) than in the control or $2{\times}2$-aggregated embryos ($23.6{\pm}1.1%$ and $12.5{\pm}2.4%$, respectively). Total blastocyst cell numbers were increased in the $2{\times}4$- and $2{\times}8$-aggregated embryos (by $44{\pm}3.0%$ and $45{\pm}3.3%$, respectively) compared with those of control or $2{\times}2$-aggregated embryos ($30.5{\pm}2.1%$ and $30.7{\pm}2.6%$, respectively; p<0.05). The levels of mRNA encoding Oct-4 were higher in both the $2{\times}4$- and $2{\times}8$-aggregated embryos than in the control. When blastocysts derived from $2{\times}4$- aggregated embryos or intact normal embryos were cultured on mouse embryonic fibroblast feeder cells to obtain porcine stem cells, blastocysts from aggregated embryos formed colonies that were better in shape compared with those derived from intact blastocysts. Together, the data show that aggregation of porcine embryos not only improves blastocyst quality but also serves as an efficient procedure by which porcine embryonic stem cells can become established.

• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.297-300
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• 1996

LBD-001, a recombinant human interferon $\gamma$ produced by genetically engineered yeast as a host system, was administered intraperitoneally to Sprague-Dawley male rats from premating to mating period at least for 60 days and to female rats from at least for 2 weeks before mating to early gestation period (from day 0 to 7 of gestation) at dose levels of $0.35\times10^6, 0.39\times10^6, and 1.38\times10^6$ I.U./kg/day. In the positive control group, ethynylestradiol ($EE_2$; 40 $\mu\textrm{g}$/kg/day) was subcutaneously administered only to female rats during the early gestation period. Effects of the test agents on reproductive performances of the male or female rats and embryonic development were as followings; (1) No significant changes by the treatment of LBD-001 were observed in general behaviors, body weight, food and water consumption, and necropsy of parent animals. However, significant decreases of body weight, food consumption, and water consumption were observed in ($EE_2$ -treated female rats. (2) Mating performances and fertility of parent animals were not significantly affected by the treatment of LBD-001. In ($EE_2$ -treated females, however, the fertility was completely inhibited. (3) No changes in resorption rate and external abnormality of F1 fetuses were observed by the treatment of LBD-001. The results show that LBD-001 at the dose of $1.38\times10^6$ I.U./kg/day or less does not affect general toxicity and reproductive function of parent animals and embryonic development of F1 fetuses.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1383-1391
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• 2016

Bovine embryonic stem cells have potential for use in research, such as transgenic cattle generation and the study of developmental gene regulation. The Nanog may play a critical role in maintenance of the undifferentiated state of embryonic stem cells in the bovine, as in murine and human. Nevertheless, efforts to study the bovine Nanog for pluripotency-maintaining factors have been insufficient. In this study, in order to understand the mechanisms of transcriptional regulation of the bovine Nanog, the 5'-flanking region of the Nanog was isolated from ear cells of Hanwoo. Results of transient transfection using a luciferase reporter gene under the control of serially deleted 5'-flanking sequences revealed that the -134 to -19 region contained the positive regulatory sequences for the transcription of the bovine Nanog. Results from mutagenesis studies demonstrated that the Sp1-binding site that is located in the proximal promoter region plays an important role in transcriptional activity of the bovine Nanog promoter. The electrophoretic mobility shift assay with the Sp1 specific antibody confirmed the specific binding of Sp1 transcription factor to this site. In addition, significant inhibition of Nanog promoter activity by the Sp1 mutant was observed in murine embryonic stem cells. Furthermore, chromatin-immunoprecipitation assay with the Sp1 specific antibody confirmed the specific binding of Sp1 transcription factor to this site. These results suggest that Sp1 is an essential regulatory factor for bovine Nanog transcriptional activity.

• The Journal of Korean Society of Virology
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• v.26 no.2
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• pp.235-244
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• 1996

We selected the adequate cell line to be used for propagation and plaquing of R. tsutsugamushi in laboratory and identified R. tsutsugamushi serotype cultured in LuMA cells by nested PCR. As in this study, we concluded that. 1. LuMA cell was suitable for the study of the biology of rickettsiae-host cell interaction. 2. The plaque-forming unit (PFU) per ml of R. tsutsugamushi Karp strain propagated in embryonated egg yolk sacs was $10^{8.8}$ and the PFU/ml of Gilliam strain was $10^{7.1}$. 3. The rate and extent of cytopathic changes depended on the PFU titer of R. tsutsugamushi. 4. PCR with nested primer pairs was useful for identification of R. tsutsugamushi serotype cultured in human embryonic lung cells.

• Reproductive and Developmental Biology
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• v.38 no.2
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• pp.79-84
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• 2014

MicroRNAs (miRNAs) are approximately 22 nucleotides of small noncoding RNAs that control gene expression at the posttranscriptional level through translational inhibition and destabilization of their target mRNAs. The miRNAs are phylogenetically conserved and have been shown to be instrumental in a wide variety of key biological processes including cell cycle regulation, apoptosis, metabolism, imprinting, and differentiation. Recently, a paper has shown that expression of the miRNA-302/367 cluster expressed abundantly in mouse and human embryonic stem cells (ESCs) can directly reprogram mouse and human somatic cells to induced pluripotent stem cells (iPSCs) efficiently in the absence of any of the four factors, Oct4, Sox2, c-Myc, and Klf4. To apply this efficient method to porcine, we analyzed porcine genomic sequence containing predicted porcine miRNA-302/367 cluster through ENSEMBL database, generated a non-replicative episomal vector system including miRNA-302/367 cluster originated from porcine embryonic fibroblasts (PEF), and tried to make porcine iPSCs by transfection of the miRNA-302/367 cluster. Colonies expressing EGFP and forming compact shape were found, but they were not established as iPSC lines. Our data in this study show that pig miRNA-302/367 cluster could not satisfy requirement of PEF reprogramming conditions for pluripotency. To make pig iPSC lines by miRNA, further studies on the role of miRNAs in pluripotency and new trials of transfection with conventional reprogramming factors are needed.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.1
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• pp.1-9
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• 2012

Because the average human life span has recently increased, the number of patients who are diagnosed with neurodegenerative diseases has escalated. Recent advances in stem cell research have given us access to unlimited numbers of multi-potent or pluripotent cells for screening for new drugs for neurodegenerative diseases. Neural stem cells (NSCs) are a good model with which to screen effective drugs that increase neurogenesis. Recent technologies for human embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) can provide human cells that harbour specific neurodegenerative disease. This article discusses the use of NSCs, ESCs and iPSCs for neurodegenerative drug screening and toxicity evaluation. In addition, we introduce drugs or natural products that are recently identified to affect the stem cell fate to generate neurons or glia.