Propagation of Human Embryonic Stem Cells on Human Amniotic Fluid Cells as Feeder Cells in Xeno-Free Culture Conditions

Juwon Jung,Jin Ah Baek,Hye Won Seol,Young Min Choi 한국발생생물학회 2016 발생과 생식 Vol.20 No.1

Human embryonic stem cells (hESCs) have been routinely cultured on mouse embryonic fibroblast feeder layers with a medium containing animal materials. For clinical application of hESCs, animal-derived products from the animal feeder cells, animal substrates such as gelatin or Matrigel and animal serum are strictly to be eliminated in the culture system. In this study, we performed that SNUhES32 and H1 were cultured on human amniotic fluid cells (hAFCs) with KOSR XenoFree and a humanized substrate. All of hESCs were relatively well propagated on hAFCs feeders with xeno-free conditions and they expressed pluripotent stem cell markers, alkaline phosphatase, SSEA-4, TRA1-60, TRA1-81, Oct-4, and Nanog like hESCs cultured on STO or human foreskin fibroblast feeders. In addition, we observed the expression of nonhuman N-glycolylneuraminic acid (Neu5GC) molecules by flow cytometry, which was xenotransplantation components of contamination in hESCs cultured on animal feeder conditions, was not detected in this xeno-free condition. In conclusion, SNUhES32 and H1 could be maintained on hAFCs for humanized culture conditions, therefore, we suggested that new xenofree conditions for clinical grade hESCs culture will be useful data in future clinical studies.

Propagation of Human Embryonic Stem Cells on Human Amniotic Fluid Cells as Feeder Cells in Xeno-Free Culture Conditions

Jung, Juwon,Baek, Jin Ah,Seol, Hye Won,Choi, Young Min The Korean Society of Developmental Biology 2016 발생과 생식 Vol.20 No.1

Human embryonic stem cells (hESCs) have been routinely cultured on mouse embryonic fibroblast feeder layers with a medium containing animal materials. For clinical application of hESCs, animal-derived products from the animal feeder cells, animal substrates such as gelatin or Matrigel and animal serum are strictly to be eliminated in the culture system. In this study, we performed that SNUhES32 and H1 were cultured on human amniotic fluid cells (hAFCs) with KO-SR XenoFree and a humanized substrate. All of hESCs were relatively well propagated on hAFCs feeders with xeno-free conditions and they expressed pluripotent stem cell markers, alkaline phosphatase, SSEA-4, TRA1-60, TRA1-81, Oct-4, and Nanog like hESCs cultured on STO or human foreskin fibroblast feeders. In addition, we observed the expression of nonhuman N-glycolylneuraminic acid (Neu5GC) molecules by flow cytometry, which was xenotransplantation components of contamination in hESCs cultured on animal feeder conditions, was not detected in this xeno-free condition. In conclusion, SNUhES32 and H1 could be maintained on hAFCs for humanized culture conditions, therefore, we suggested that new xeno-free conditions for clinical grade hESCs culture will be useful data in future clinical studies.

Population genetic analysis reveals secondary contact between Eriocheir sinensis and E. japonica in South Korea

Jung Jibom,Wu Xugan,Park Taeseo,Lee Seok-hyun,Hwang Hee-seung,Jung Juwon,Jung Jongwoo 한국유전학회 2022 Genes & Genomics Vol.44 No.5

Background: The Chinese mitten crab (Eriocheir sinensis) and the Japanese mitten crab (E. japonica) of the family Varunidae, which are also critical fishery species in their native habitats, including China, Japan, and South Korea, exhibit a rare migration life history for the decapod life cycle. Eriocheir sinensis and E. japonica in South Korea may have originated from speciation or secondary contact in South Korea after speciation of these two species; however, the genetic relationship between these South Korean populations remains unclear, and need to be clarified. Objective: This study examined the population genetic properties of E. sinensis and E. japonica in South Korea to reveal the origin of their co-existence. Methods: Mitochondrial DNA cytochrome c oxidase I sequences of 120 E. sinensis and E. japonica from 6 sampling sites in South Korea were sequenced. Their genetic diversity and haplotype data were compared to previously reported data from the Chinese mainland, Taiwan, Japan, and Russia. Results: The haplotype network, analysis of molecular variance, FST values, Mantel test, and Bayesian skyline plot results of South Korean E. sinensis and E. japonica demonstrated that E. sinensis and E. japonica were isolated from their central populations, Chinese and Japanese populations, by the distance due to the temperature, salinity, ocean current flow, or a geohistorical event. In addition, genetic analysis indicated that the South Korean populations of the two species were marginal populations, exhibiting low genetic diversity, significant negative neutrality values, and radial haplotype networks. The current results also suggest that the Geum River is an overlapping habitat for the natural populations of E. sinensis and E. japonica in South Korea. Further research is required to examine the geohistorical and evolutionary event between E. sinensis and E. japonica in South Korea. Conclusions: The co-existence of E. sinensis and E. japonica in South Korea may have originated from secondary contact after their speciation.

Effective cryopreservation method by controlling the clump size of human embryonic stem cells

Juwon Jung,Hye Won Seol,Jin Ah Baek,Bo Ae Yoon,Hee-Sun Kim,Sun Kyung Oh,Seung-Yup Ku,Seok Hyun Kim,Shin Yong Moon,Young Min Choi 한국발생생물학회 2011 한국발생생물학회 학술발표대회 Vol.30 No.-

Human embryonic stem cells (hESCs) have the potential for use in regenerative medicine and in the field of basic research. Therefore, effective cryopreservation and storage of hESCs are important for preservation of newly established cell line for various purposes. Despite poor survival and slow recovery after thawing, the conventional slow freezing method is most commonly used for cryopreservation of hESCs due to its simplicity and ease of use for freezing a large number of hESCs appropriate to clinical applications. Here we controlled the clump size (Group Ⅰ; 400~450 ㎛, Group Ⅱ; 800~900 ㎛, and Group Ⅲ; 1500~1700 ㎛) of hESCs at 5 days after plating using a glass pipette during cryopreservation in order to obtain a larger amount of hESCs after thawing. Attachment rates differed significantly (P<0.05) in each of the three groups and the average of attachment rate of GroupⅡ was highest in SNUhES4 and H1. In particular, the attachment rate of Group Ⅱ in SNUhES3 showed a significant improvement with ROCK inhibitor Y-27632. These results indicate that clump size and cell-cell adhesions of GroupⅡ are appropriate for cryopreservation compared to the Group Ⅰ and Group Ⅲ. This method increased cell viability and reduced the recovery time leading to various experiments, and therefore has an advantage for use with hESCs like newly established in particular. We demonstrated that use of this effective cryopreservation method with control of the clump size of hESCs can effectively improve the attachment rate and survival of post-thaw hESCs with and without Y-27632.

인간 전분화능줄기세포에서 유전자 편집 기술의 연구 동향

정주원 ( Juwon Jung ),오선경 ( Sun Kyung Oh ),최영민 ( Young Min Choi ) 서울대학교 인구의학연구소 2014 人口醫學硏究論集 Vol.27 No.-

Human pluripotent stem cells(hPSCs) are useful resource for cell replacement therapy and modeling of human diseases. Recently, genome editing technologies have has been applied in hPSCs that are rapidly developed for targeted gene function of the human genome. These technologies including zinc finger nucleases(ZFNs), transcription activator like effector nucleases (TALENs) and clustered regulary interspaced short palindromic repeat(CRISPR)/CRISPR associated protein 9(CAS9) RNA guided nucleases are genetically modified tools which have potentials for diverse biolohical research fields. In this review, we discussed an overview of genome editing merhods and understanding their characters and drawback of this manipulation.

도로 교통망에 대한 사용자의 선호도 변화를 반영한 경로 추천

정주원(Juwon Jung),박석(Seog Park) Korean Institute of Information Scientists and Eng 2019 정보과학회논문지 Vol.46 No.1

The current location based services provide maps and nearby information, or provide a route to a specific destination. A route recommendation system recommends the best route that suits the evaluation criteria for each user. The existing personalized path recommendation system recommends the route under the assumption that the user’s preference is constant regardless of the change of the time zone. However, there is a problem in that it does not reflect requirements that important factors to users can be different for each time zone, such as importance of moving distance in morning time and importance of risk in late time. In this paper, we propose a Dijkstra algorithm considering time attributes to overcome this limitation. In addition, we suggest an efficient algorithm that can search the path reflecting the change of the weight of the preference factor according to the time zone using the G-tree index structure that effectively expresses the road network.

교육실습에서 중등 예비과학교사들의 수업계획과 실제수업의 불일치 분석

정주원 ( Juwon Jung ),이봉우 ( Bongwoo Lee ) 한국과학교육학회 2016 한국과학교육학회지 Vol.36 No.3

본 연구의 목적은 예비과학교사들의 수업설계와 실제수업의 불일 치내용을 분석하고 그 발생 원인을 고찰하는 것이다. 이를 위해서 2015년 4월부터 5월까지 실시된 교육실습에 예비과학교사 20명이 참여하였고, 예비과학교사들이 작성한 수업지도안과 수업을 분석하여 불일치한 내용을 추출하고, 면담을 실시하였다. 주요 연구 결과는 다음과 같다. 첫째, 도입 단계에서는 ``주의집중 및 동기유발`` 영역에서 가장 많은 불일치 사례가 발견되었으며, 예비과학교사들은 동기유발 요소를 다른 형태로 수정한 경우가 많았다. 둘째, 전개 단계에서는 가장 많은 불일치 사례가 발견되었는데, 특히 ``학습내용제시`` 활동에서 학습내용을 추가적으로 제시하여 수업을 하는 경우가 많았다. 셋째, 마무리단계에서는 시간의 부족으로 ``학습내용요약`` 활동이 누락된 사례가 많았다. 넷째, 예비과학교사들의 수업계획과 실제수업의 불일치 발생원인은 내부요인과 외부요인이 비슷하였으며, 외부요인 으로는 지도교사의 피드백과 학생반응에 의한 변화가 가장 많이 발생 하였다. 추가적으로 예비과학교사의 수업전문성 신장과 관련하여 반성적 멘토링 프로그램, 지도교사의 중요성, 시간 관리의 중요성 등과 관련된 시사점을 논의하였다. The purpose of this study is to analyze the mismatch between instructional design and teaching practice of pre-service science teachers and to investigate the cause of these mismatches. Twenty pre-service science teachers took part in teaching practicum for four weeks from Apr. 2015 to May 2015 and we analyzed their lesson plans and videos of these lessons. After that, we interviewed the pre-service science teachers in order to know the cause of these mismatches and additional informations. The main findings are as follows. First, in the introductory stage, we found more mismatch in the "attention and motivation stimulation" area than any other area. Many pre-service science teachers corrected their ``motivation practice`` in different forms. Second, we found out that the most mismatch occurred in the evolving stage. Many pre-service science teachers added learning contents in "learning content presentation" area. Third, in the closing stage, many pre-service science teachers omitted the "leaning content summary" area in the lack of time. Fourth, the number of mismatches by internal factors is similar of by external factors. The mismatches by external factors were mainly by feedback of guidance teacher and change by students` response. In addition, we discussed the implications related to reflective mentoring program, importance of guidance teacher, importance of time management etc.

Microstructural design of high nickel cathode toward outstanding capacity and stability using trace element doping for lithium-ion battery application

Juwon Park(박주원),Won Myung Choi(최원명),Hiram Kwak(곽희람),Yoon Seok Jung(정윤석),Byungchan Han(한병찬) 한국표면공학회 2022 한국표면공학회 학술발표회 초록집 Vol.2022 No.6

Adipose tissue-derived mesenchymal stem cells cultured at high density express IFN-β and TRAIL and suppress the growth of H460 human lung cancer cells

Jung, Pil Young,Ryu, Hoon,Rhee, Ki-Jong,Hwang, Soonjae,Lee, Chang Gun,Gwon, Sun-Yeong,Kim, Jiye,Kim, Juwon,Yoo, Byung-Su,Baik, Soon Koo,Bae, Keum Seok,Eom, Young Woo Elsevier 2019 Cancer letters Vol.440 No.-

<P><B>Abstract</B></P> <P>Although mesenchymal stem cells (MSCs) have been reported to inhibit tumor growth, the mechanism controlling this tumor suppression function is unclear. Here, we report that high-density (40,000 cells/cm<SUP>2</SUP>) cultured adipose tissue-derived MSCs (40K-ASCs) expressed interferon (IFN)-β and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL); we also found that serum deprivation during cell culture induced the expression of IFN-β and TRAIL. In addition, the mRNA expression of <I>IFN-β</I>, but not <I>TRAIL</I>, was increased during the washing step required for the transplantation of normal-density (5000 cells/cm<SUP>2</SUP>) cultured ASCs (5K-ASCs). When the human lung cancer cell line H460 was co-cultured with 40K-ASCs, necrotic cell death was dramatically increased <I>in vitro</I>. When ASCs were injected after four washes, both 5K-ASCs and 40K-ASCs substantially reduced tumor weight in H460-derived cancer animal models. These results suggest that serum deprivation during the culture of 40K-ASCs or during the washing step of 5K-ASCs can induce IFN-β and/or TRAIL expression, ultimately leading to the tumor suppression capability of ASCs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High-density cultured ASCs expressed IFN-β and TRAIL. </LI> <LI> Serum deprivation induced IFN-β/TRAIL expression in high-density cultured ASCs. </LI> <LI> <I>IFN-β</I> mRNA expression was increased during washing with phosphate-buffered saline. </LI> <LI> H460 necroptosis occurred in culture with high-density cultured ASCs. </LI> <LI> High-density cultured ASCs reduced tumor weight in murine xenograft model. </LI> </UL> </P>

Analyzing the Impact of Corporation Corruption on Climate Change by Viterbi Algorithm(HMMs)

Jung, Chaeyun,Lee, Juwon 한국기후변화학회 2013 한국기후변화학회지 Vol.4 No.4