Chemical Derived Patient-Specific Hepatic Stem Cells from Various Patients

( Kyojin Kang ),( Yohan Kim ),( Sangtae Yoon ),( Elina Maria Buisson ),( Changhee Lee ),( Ji-hye Yim ),( Jaemin Jeong ),( Dongho Choi ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Hepatocyte like cells can be derived from many different sources of stem cells including induced pluripotent stem cells, embryonic stem cells or directly converted cells. These Methods: are well developed, however, some problems such as tumor formation, low functionality and differentiation ratio as well as genomic variation are yet to be solved. Methods: We have developed a method using two small molecules and no ectopic gene expression to develop patient-specific hepatic stem cells (hCdH) from primary hepatocytes. Of interest, from 52 patients healthy and diseased patient livers, we were able to generate hCdH. Results: Among the 52 patients, significant differences in fibrosis were observed with 4.17% and 52% in the normal and diseased group respectively. The harvested hepatocytes ratio (number of cells/the liver weight) also differed with a mean of 5.9x10⁶ in normal livers and 1.1x10⁶ in diseased livers. In normal livers ALP ranged from 66 to 95 U/L whilst there was a significant increase in the ALP level of diseased livers ranging from 80 to 174 U/L. Through the evaluation of different platforms such as generation and differentiation ratio, hepatic marker expression and functionality of these hCdHs, we were able to find the most significant difference in the statistical analysis between the generation of CdH in healthy and diseased livers and the level of ALP(alkaline phosphatase). Through FACS analysis we were also able to find the stemness marker NPB24-B3 obtained from embryonic stem cells as a characteristic of CdH and sorted 36.2% of the cells accordingly. Conclusions: Although the CdH characteristics vary, it was possible to generate CdH from all patients. We therefore suggest that the functional state and generation efficiency of CdH are related to patient liver condition. In further studies, we plan to use the CdH marker to sort the cells obtained from the patients to allow for homogeneous population.

Association Among Self-Injury, Suicidal Tendency, and Personality and Psychological Characteristics in Korean Adolescents

Kyojin Yang,Si Young Kim,Hyejin Kim,Jun-Won Hwang 대한신경정신의학회 2022 PSYCHIATRY INVESTIGATION Vol.19 No.1

Objective To compare mental health problems and personality characteristics between adolescents with self-injury (SI) and suicidal tendency (ST), including suicidal ideation and suicide planning. Methods The participants completed the Adolescent Personality and Mental Health Problems Screening Questionnaire, Third version (AMPQ-III), and Korean version of the Strengths and Difficulties Questionnaire (SDQ-Kr), and gave their demographic information. Based on the answered SI and ST items in AMPQ-III, the participants were divided into groups: without SI and ST, with SI and without ST, without SI and with ST, and with SI and ST. Analysis of variance (ANOVA) and post-hoc Scheffe test were used to determine group differences, stepwise multiple linear regression, and factors associated with SI and ST. Results ANOVA yielded results for all categories of mental health problems. Significant differences were observed between the four groups. Conversely, for personality characteristics, only the sense of community item between the group without SI and with ST and the group without SI and ST were significantly different; sense of community was associated with ST (β=-0.054, p=0.005). Among the mental health subscales, SI was significantly associated with conduct problems (β=0.211, p<0.001), emotional problems (β=0.173, p<0.001), peer problems (β=0.085, p<0.001), and prosocial behavior (β=0.073, p<0.001). ST was significantly associated with emotional symptoms (β=0.317, p<0.001), peer problems (β=0.130, p<0.001), conduct problems (β=0.106, p<0.001), hyperactivity (β=0.050, p=0.010), and prosocial behavior (β=0.062, p<0.001). Conclusion The findings highlight the necessity of assessing psychological strength, difficulties, and personality characteristics for the prevention and early intervention of adolescent SI.

Simultaneous determination of 10 new amphetamines in human urine by protein precipitation and LC-MS/MS

Kyojin Kim,Hyewon Seo,Hye jin Cha,Jisoon Shin,Young-Hoon Kim,Jayoung Jeong,Soo Kyung Suh 한국분석과학회 2018 학술대회논문집 Vol.2018 No.5

북한 ‘수령’ 성격 규정의 다양성 및 그 변용에 관한 연구

정교진 ( Kyojin Jung ) 연세대학교 통일연구원 2022 통일연구 Vol.26 No.1

1967년, 김일성에게 수령 칭호를 공식화했던 북한은 1972년에는 인민민주주의헌법을 사회주의헌법으로 전환하며 ‘수령제’ 정치체제를 확립했다. 1974년은 ‘수령혁명론’(혁명적 수령관)을 내세워 북한을 수령중심주의(수령제일주의) 통치체제로 완성했다. 이론적으로 북한 최고지도자가 ‘수령’(뇌수)의 지위를 확보한 것이다. ‘수령론’과 ‘후계자론’도 이 논리를 더욱 보강해주어 ‘수령론’은 수령을 제도화시켰고 ‘후계자론’은 ‘미래의 수령’을 제시하였다. 이런 측면에서 볼 때, 김정은은 2012년 정권을 승계한 때부터 정치적으로 ‘수령’의 지위를 확보한 셈이다. 하지만 아이러니하게도 북한의 당 기관지 노동신문을 검토해 볼 때 2020년까지 김정은 이름 앞뒤에 직접적으로 수령이라는 수식어가 붙지 않았다. 김정은을 수령으로 암시해 주는 문장도 2014년이나 되어서야 나타나는 것으로 보인다. 그러던 북한이 2021년 1월, 제8차 당 대회를 개최하고 김정은을 ‘당 총비서’로 추대하면서 그 추대사 내용에 그를 ‘인민적 수령’이라고 지칭했다. 이후 노동신문은 5월 14일 자, <정론>에 처음으로 김정은의 이름에 직접적으로 ‘수령’이라는 수식어를 붙였다. 그 이후 노동신문의 기사들은 자연스럽게 김정은을 수령으로 표기하기 시작했다. 한 노동신문 <사설>은 김정은이 제8차 당 대회에서 수령으로 정식화되었음을 분명하게 밝혀주기도 했다 이처럼, 김정은이 2021년에 수령으로 정식화된 북한의 현실정치를 ‘수령론’과 ‘후계자론’으로는 설명하기가 쉽지 않다. 따라서 본 연구는 수령이 하나의 지도자 이미지라는 점에 착안하고 ‘지도자(수령) 이미지의 상징화’라는 개념으로 접근해서 이 현상을 고찰하며 해석을 하고자 했다. 그 결과, 다음과 같은 결과물을 얻었다. 김정은의 수령 이미지 생성(2014) → 수령 이미지 구축(2016) → 수령 이미지 강화(2019) → 수령 이미지 고착화/상징성 확보(2021)라는 단계가 성립되었다. 따라서 2012년에 암묵적인 수령의 지위 인정에서 2021년에 수령의 지위 정식화라는 북한의 현실정치를 유의미하게 설명할 수 있게 되었다. 2021년 제8차 당 대회는 김정은을 수령으로 정식화했을 뿐만 아니라, 김정은의 혁명사상(김정은주의)도 내세운 바 있다. 여기에는 수령은 영도뿐만 아니라 사상을 제시해야 된다는 논리가 작동되었다. 이처럼, 북한에서 수령과 혁명사상은 불가분의 관계이다. 수령 김정은에게 있어서 그의 독자적인 혁명사상의 대두는 필연적이었던 것이다. 북한은 김정은을 ‘인민적 수령’을 내세우며 그의 혁명사상을 ‘애민관’에 초점을 맞추었다. 여기에서 ‘인민을 더 잘 섬기기 위해서’라는 김정은 수령 정식화의 정당성이 확보되어 진다. North Korea, which formalized the title of ‘Suryong(supreme leader)’ to Kim Ilsung in 1967, converted the People’s Democratic Constitution into a socialist constitution in 1972 and established a “Suryong system” as a political system. In 1974, the “suryong revolution theory” completed North Korea as a Suryong-centered governing system. Theoretically, the supreme leader of North Korea has secured the status of “Suryong” (the brain). ‘Suryong Theory’ and ‘Successor Theory’ further reinforced this logic, so the Suryong theory institutionalized the Suryong, and the Succession theory suggested the ‘future Suryong’. In this respect, Kim Jongun has secured the status of a “Suryong” politically since he took over in 2012. However, ironically, when reviewing North Korea’s official newspaper Rodong Sinmun, Kim Jongun’s name did not appear with the modifier “Suryong” directly around it until 2020. A sentence that implicated Kim Jongun as the Suryong finally did appear until 2014. Therefore, the title of Suryong was nothing but the domain of Kim Ilsung until 2020. However, when North Korea held the 8th party congress in January 2021, it appointed Kim Jongun as the “general secretary of the party” and referred to Kim Jongun as the “people’s Suryong” in the recommendation speech. since then, the Rodong Sinmun has directly attached the modifier ‘Suryong’ to Kim Jongun’s name for the first time at the editorial on May 14. since then, articles in the Rodong Sinmun have naturally referred to Kim Jongun as Suryong. An editorial in the Rodong Sinmun made it clear that Kim Jongun was enthroned as Suryong at the 8th Party Congress. In this way, it is not easy to explain the reality of North Korea’s politics, in which Kim Jongun is appointed as Suryong in 2021, with the ‘Suryong theory’ and the ‘successor theory’. Therefore, this study focused on the fact that the Suryong is an image of a leader, approached it with the concept of ‘symbolization of the leader (suryong) image’, considered this phenomenon and attempted to analyze it, and the following results were obtained. The steps and process from making Suryong images toward securing the symbolization were established as below. The creation of the image of Suryong (2014) → building of the image of Suryong(2016) → strengthening of the image of Suryong (2019)→ fixing of the image of Suryong/securing of the symbol of Suryong (2021). Therefore, from the implicit recognition of the status of the Suryong in 2012 to the formalization of the status of the Suryong in 2021, that is, it is possible to meaningfully explain the reality of North Korea’s politics, which is Kim Jongun’s Suryong enthronement. The 8th Party Congress in 2021 not only formalized Kim Jongun as the Suryong, but also promoted Kim Jongun’s revolutionary ideology (Kim Jongunism). The logic was oprerated that the Suryong should present not only leadership but also ideology. As such, the Suryong and revolutionary ideology are inextricably linked in North Korea. In addition, North Korea focused on Kim Jongun’s ‘view of loving people’ by promoting the image of ‘people’s Suryong’. Here too, another justification for Kim Jongun’s Suryong enthronement, “to serve the people better”, is secured.

나노복합 하이드로젤 기반 압력 센서의 제작 및 응용

안교진(Kyojin Ahn),김연수(Younsoo Kim) 한국고분자학회 2021 고분자 과학과 기술 Vol.32 No.1

Suppression of Voltage Decay through Manganese Deactivation and Nickel Redox Buffering in High-Energy Layered Lithium-Rich Electrodes

Ku, Kyojin,Hong, Jihyun,Kim, Hyungsub,Park, Hyeokjun,Seong, Won Mo,Jung, Sung-Kyun,Yoon, Gabin,Park, Kyu-Young,Kim, Haegyeom,Kang, Kisuk Wiley (John WileySons) 2018 ADVANCED ENERGY MATERIALS Vol.8 No.21

Gut Microbial Metabolites Induce Changes in Circadian Oscillation of Clock Gene Expression in the Mouse Embryonic Fibroblasts

Ku, Kyojin,Park, Inah,Kim, Doyeon,Kim, Jeongah,Jang, Sangwon,Choi, Mijung,Choe, Han Kyoung,Kim, Kyungjin Korean Society for Molecular and Cellular Biology 2020 Molecules and cells Vol.43 No.3

Circadian rhythm is an endogenous oscillation of about 24-h period in many physiological processes and behaviors. This daily oscillation is maintained by the molecular clock machinery with transcriptional-translational feedback loops mediated by clock genes including Period2 (Per2) and Bmal1. Recently, it was revealed that gut microbiome exerts a significant impact on the circadian physiology and behavior of its host; however, the mechanism through which it regulates the molecular clock has remained elusive. 3-(4-hydroxyphenyl)propionic acid (4-OH-PPA) and 3-phenylpropionic acid (PPA) are major metabolites exclusively produced by Clostridium sporogenes and may function as unique chemical messengers communicating with its host. In the present study, we examined if two C. sporogenes-derived metabolites can modulate the oscillation of mammalian molecular clock. Interestingly, 4-OH-PPA and PPA increased the amplitude of both PER2 and Bmal1 oscillation in a dose-dependent manner following their administration immediately after the nadir or the peak of their rhythm. The phase of PER2 oscillation responded differently depending on the mode of administration of the metabolites. In addition, using an organotypic slice culture ex vivo, treatment with 4-OH-PPA increased the amplitude and lengthened the period of PER2 oscillation in the suprachiasmatic nucleus and other tissues. In summary, two C. sporogenes-derived metabolites are involved in the regulation of circadian oscillation of Per2 and Bmal1 clock genes in the host's peripheral and central clock machineries.

Generation of Multilayered 3D Structures of HepG2 Cells Using a Bio-printing Technique

( Hyeryeon Jeon ),( Kyojin Kang ),( Su A Park ),( Wan Doo Kim ),( Seung Sam Paik ),( Sang-hun Lee ),( Jaemin Jeong ),( Dongho Choi ) 대한소화기학회 2017 Gut and Liver Vol.11 No.1

Background/Aims: Chronic liver disease is a major widespread cause of death, and whole liver transplantation is the only definitive treatment for patients with end-stage liver diseases. However, many problems, including donor shortage, surgical complications and cost, hinder their usage. Recently, tissue-engineering technology provided a potential breakthrough for solving these problems. Three-dimensional (3D) printing technology has been used to mimic tissues and organs suitable for transplantation, but applications for the liver have been rare. Methods: A 3D bioprinting system was used to construct 3D printed hepatic structures using alginate. HepG2 cells were cultured on these 3D structures for 3 weeks and examined by fluorescence microscopy, histology and immunohistochemistry. The expression of liverspecific markers was quantified on days 1, 7, 14, and 21. Results: The cells grew well on the alginate scaffold, and liver-specific gene expression increased. The cells grew more extensively in 3D culture than two-dimensional culture and exhibited better structural aspects of the liver, indicating that the 3D bioprinting method recapitulates the liver architecture. Conclusions: The 3D bioprinting of hepatic structures appears feasible. This technology may become a major tool and provide a bridge between basic science and the clinical challenges for regenerative medicine of the liver. (Gut Liver 2017;11:121-128)

Three-dimensional (3D) printing of mouse primary hepatocytes to generate 3D hepatic structure

Yohan Kim,Kyojin Kang,Jaemin Jeong,Seung Sam Paik,Ji Sook Kim,Su A Park,Wan Doo Kim,Jisun Park,Dongho Choi 대한외과학회 2017 Annals of Surgical Treatment and Research(ASRT) Vol.92 No.2

Purpose: The major problem in producing artificial livers is that primary hepatocytes cannot be cultured for many days. Recently, 3-dimensional (3D) printing technology draws attention and this technology regarded as a useful tool for current cell biology. By using the 3D bio-printing, these problems can be resolved. Methods: To generate 3D bio-printed structures (25 mm × 25 mm), cells-alginate constructs were fabricated by 3D bio-printing system. Mouse primary hepatocytes were isolated from the livers of 6–8 weeks old mice by a 2-step collagenase method. Samples of 4 × 10<SUP>7</SUP> hepatocytes with 80%–90% viability were printed with 3% alginate solution, and cultured with well-defined culture medium for primary hepatocytes. To confirm functional ability of hepatocytes cultured on 3D alginate scaffold, we conducted quantitative real-time polymerase chain reaction and immunofluorescence with hepatic marker genes. Results: Isolated primary hepatocytes were printed with alginate. The 3D printed hepatocytes remained alive for 14 days. Gene expression levels of Albumin , HNF-4α and Foxa3 were gradually increased in the 3D structures. Immunofluorescence analysis showed that the primary hepatocytes produced hepatic-specific proteins over the same period of time. Conclusion: Our research indicates that 3D bio-printing technique can be used for long-term culture of primary hepatocytes. It can therefore be used for drug screening and as a potential method of producing artificial livers.

Indentification of phase I metablites of 25I-NBF in human liver microsomes by LC-high resolution MS/MS

Hyewon Seo,Kyojin Kim,Hye Jin Cha,Jisoon Shin,Young-Hoon Kim,Jayoung Jeong,Soo Kyung Suh 한국분석과학회 2018 학술대회논문집 Vol.2018 No.5