• Molecules and Cells
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• 제37권6호
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• pp.497-502
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• 2014

Microfluidics can provide unique experimental tools to visualize the development of neural structures within a microscale device, which is followed by guidance of neurite growth in the axonal isolation compartment. We utilized microfluidics technology to monitor the differentiation and migration of neural cells derived from human embryonic stem cells (hESCs). We co-cultured hESCs with PA6 stromal cells, and isolated neural rosette-like structures, which subsequently formed neurospheres in suspension culture. Tuj1-positive neural cells, but not nestin-positive neural precursor cells (NPCs), were able to enter the microfluidics grooves (microchannels), suggesting that neural cell-migratory capacity was dependent upon neuronal differentiation stage. We also showed that bundles of axons formed and extended into the microchannels. Taken together, these results demonstrated that microfluidics technology can provide useful tools to study neurite outgrowth and axon guidance of neural cells, which are derived from human embryonic stem cells.

• 한국컴퓨터정보학회논문지
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• 제15권6호
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• pp.81-89
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• 2010

이 연구의 목적은 교육용 로봇을 활용한 STEM 통합교육이 수학 교과의 태도 수준 향상에 미치는 영향을 검증하는데 있다. 이러한 목적을 달성하기 위하여 다음과 같은 가설을 설정하였다. 교육용 로봇을 활용한 STEM 통합교육과 기존 전통적인 수학 학습에 의한 초등학생들의 수학 교과 태도 수준에는 유의미한 차이가 있을 것이다. 이와 같은 가설을 검증하기 위하여 초등학교 1학년 56명을 대상으로 이질 통제 집단 전후 검사 설계 방식을 적용하였다. 연구의 결과로 이 연구의 가설은 채택 되었으며, 교육용 로봇을 활용한 STEM 통합교육은 초등학생의 수학 교과태도 수준 신장에긍정적인 영향을 미치는 것으로 나타났다. 향후 다양한 교과의 지식과 활동을 교육용 로봇을 매개로 통합 융합할 수 있는 교육활동이 필요하다.

• BMB Reports
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• 제53권8호
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• pp.425-430
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• 2020

Tumor necrosis factor-inducible gene 6 protein (TSG-6) is a cytokine secreted by mesenchymal stem cells (MSCs) and regulates MSC stemness. We previously reported that TSG-6 changes primary human hepatic stellate cells (pHSCs) into stem-like cells by activating yes-associated protein-1 (YAP-1). However, the molecular mechanism behind the reprogramming action of TSG-6 in pHSCs remains unknown. Cluster of differentiation 44 (CD44) is a transmembrane protein that has multiple functions depending on the ligand it is binding, and it is involved in various signaling pathways, including the Wnt/β-catenin pathway. Given that β-catenin influences stemness and acts downstream of CD44, we hypothesized that TSG-6 interacts with the CD44 receptor and stimulates β-catenin to activate YAP-1 during TSG-6-mediated transdifferentiation of HSCs. Immunoprecipitation assays showed the interaction of TSG-6 with CD44, and immunofluorescence staining analyses revealed the colocalization of TSG-6 and CD44 at the plasma membrane of TSG-6-treated pHSCs. In addition, TSG-6 treatment upregulated the inactive form of phosphorylated glycogen synthase kinase (GSK)-3β, which is a negative regulator of β-catenin, and promoted nuclear accumulation of active/nonphosphorylated β-catenin, eventually leading to the activation of YAP-1. However, CD44 suppression in pHSCs following CD44 siRNA treatment blocked the activation of β-catenin and YAP-1, which inhibited the transition of TSG-6-treated HSCs into stem-like cells. Therefore, these findings demonstrate that TSG-6 interacts with CD44 and activates β-catenin and YAP-1 during the conversion of TSG-6-treated pHSCs into stem-like cells, suggesting that this novel pathway is an effective therapeutic target for controlling liver disease.

• BMB Reports
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• 제48권4호
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• pp.193-199
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• 2015

Degenerative retinal diseases affect millions of people worldwide, which can lead to the loss of vision. However, therapeutic approaches that can reverse this process are limited. Recent efforts have allowed the possibility of the stem cell-based regeneration of retinal cells and repair of injured retinal tissues. Although the direct differentiation of pluripotent stem cells into terminally differentiated photoreceptor cells comprises one approach, a series of studies revealed the intrinsic regenerative potential of the retina using endogenous retinal stem cells. Muller glial cells, ciliary pigment epithelial cells, and retinal pigment epithelial cells are candidates for such retinal stem cells that can differentiate into multiple types of retinal cells and be integrated into injured or developing retina. In this review, we explore our current understanding of the cellular identity of these candidate retinal stem cells and their therapeutic potential for cell therapy against degenerative retinal diseases. [BMB Reports 2015; 48(4): 193-199]

• 대한지구과학교육학회지
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• 제13권1호
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• pp.121-133
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• 2020

본 연구는 융합(STEM)교육의 핵심인 공학 설계를 기반으로 과학 수업에서 공학을 의미있고 쉽게 융함하여 수업을 설계할 수 있도록 수업 준거틀을 제안 한 것이다. 본 연구에서 개발된 과학·공학 융합 수업 준거틀은 과학과 공학 융합 교육에 대한 국내외 이론적, 실제적 선행 연구 분석과 전문가 토의, 그리고 현장교사들의 피드백에 근거하여 개발되었다. 과학·공학 융합 수업 준거틀은 과학 수업에서 공학 설계를 주요 교수법 및 문제해결 방법으로 사용하며, 선행 연구에서 제시된 공학 융합 수업의 핵심요소와 학년군별 성취수준을 고려하여 공학 설계에 대한 이해가 부족한 현장 교사들이 쉽게 공학 설계를 과학 수업에 도입할 수 있는 방법을 제공한다. 또한 본 연구에서 개발된 과학·공학 융합 수업 준거틀은 복잡하게 제시된 한국 STEAM 교육 준거틀의 단점을 보완하여 현장교사뿐 아니라 예비교사들이 쉽게 공학적 설계와 문제해결과정에 대해 이해하고 이를 적용하여 과학 융합 수업을 설계하는데 구체적인 지침을 제공할 수 있다.

• 대한의생명과학회지
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• 제19권1호
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• pp.32-40
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• 2013

Pluripotent stem cells (PSCs) have enormous potential in the biomedical sciences because they can grow continuously and differentiate into any kind of cell in the body. However, for future application in regenerative medicine, it is still a challenge to control the differentiation of PSCs without using genetic materials. To control the differentiation of PSCs, small molecules might be the best substitute for genetic materials considering the following advantages: small size, which enables penetration of plasma membrane; easy-to-modify structure; and low chance of genetic recombination in treated cells. Herein, we introduce small molecules that induce the neuroectodermal differentiation of mouse embryonic stem cells (ESCs). The small molecules were identified via ESC-based consecutive screenings of small-molecule libraries composed of 324 natural compounds or 93 selected drugs. The natural compounds discovered in the first screening were used to select 93 structurally similar drugs out of 1,200 approved drugs. In the second screening, among the 93 compounds, we found 4 drugs that induced the neuroectodermal differentiation of ESCs. These drugs were progesteroneor corticoid-derivatives. Our results suggest that small molecules targeting the progesterone receptor or glucocorticoid receptor could be used as chemical tools to induce the differentiation of PSCs into a specific germ lineage.

• 정보교육학회논문지
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• 제17권2호
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• pp.177-189
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• 2013

국제학업성취도 비교 연구에 따르면 우리나라 학생들은 과학 수학교과에서 높은 수준의 학업성취결과를 나타낸 반면 학습 동기는 상대적으로 낮게 나타났다. 이에 본 연구는 엔지니어링 수업 모델을 적용한 로봇활용 STEM 융합교육 프로그램을 개발하였다. 프로그램의 주제는 4학년 과학교육과정의 한 단원이면서 학생들에게 친숙하고 로봇의 활용이 효과적인 '동물'로 정하였다. 로봇활용 STEM 프로그램은 로봇소양교육, 주제관련 교과학습, 엔지니어링 교육활동의 세 영역으로 구성되었다. 개발된 STEM 프로그램은 현장교사 14명으로부터 검토를 받았으며 연구결과 로봇 소양 유무에 상관없이 대부분의 교사가 프로그램의 목표, 내용 구성, 로봇의 활용에 대해 긍정적 반응을 나타내었다.

• Molecules and Cells
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• 제37권2호
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• pp.133-139
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• 2014

Idiopathic pulmonary fibrosis (IPF) is the most common and severe type of idiopathic interstitial pneumonias (IIP), and which is currently no method was developed to restore normal structure and function. There are several reports on therapeutic effects of adult stem cell transplantations in animal models of pulmonary fibrosis. However, little is known about how mesenchymal stem cell (MSC) can repair the IPF. In this study, we try to provide the evidence to show that transplanted mesenchymal stem cells directly replace fibrosis with normal lung cells using IPF model mice. As results, transplanted MSC successfully integrated and differentiated into type II lung cell which express surfactant protein. In the other hand, we examine the therapeutic effects of microvesicle treatment, which were released from mesenchymal stem cells. Though the therapeutic effects of MV treatment is less than that of MSC treatment, MV treat-ment meaningfully reduced the symptom of IPF, such as collagen deposition and inflammation. These data suggest that stem cell transplantation may be an effective strategy for the treatment of pulmonary fibrosis via replacement and cytoprotective effect of microvesicle released from MSCs.

• 한국발생생물학회지:발생과생식
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• 제25권4호
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• pp.279-291
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• 2021

Hair loss is one of the most common chronic diseases, with a detrimental effect on a patient's psychosocial life. Hair loss results from damage to the hair follicle (HF) and/or hair regeneration cycle. Various damaging factors, such as hereditary, inflammation, and aging, impair hair regeneration by inhibiting the activation of hair follicle stem cells (HFSCs) and dermal papilla cells (DPCs). Formyl peptide receptor 2 (FPR2) regulates the inflammatory response and the activity of various types of stem cells, and has recently been reported to have a protective effect on hair loss. Given that stem cell activity is the driving force for hair regeneration, we hypothesized that FPR2 influences hair regeneration by mediating HFSC activity. To prove this hypothesis, we investigated the role of FPR2 in hair regeneration using Fpr2 knockout (KO) mice. Fpr2 KO mice were found to have excessive hair loss and abnormal HF structures and skin layer construction compared to wild-type (WT) mice. The levels of Sonic hedgehog (Shh) and β-catenin, which promote HF regeneration, were significantly decreased, and the expression of bone morphogenetic protein (Bmp)2/4, an inhibitor of the anagen phase, was significantly increased in Fpr2 KO mice compared to WT mice. The proliferation of HFSCs and DPCs was significantly lower in Fpr2 KO mice than in WT mice. These findings demonstrate that FPR2 impacts signaling molecules that regulate HF regeneration, and is involved in the proliferation of HFSCs and DPCs, exerting a protective effect on hair loss.

• Molecules and Cells
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• 제27권6호
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• pp.615-620
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• 2009

The plant shoot meristem maintains a group of stem cells that remain active throughout the plant life. They continuously generate new cells that are then recruited for organ initiation in the peripheral zone. Stem cell proliferation and daughter cell differentiation has to be integrated with overall growth and development of the diverse functional domains within the shoot apex. Several studies have revealed extensive communication between these domains. The signaling mechanisms employed comprise diffusible peptides, directional transport of plant hormones, but also complex interactions between transcription factors, that together establish a panoply of regulatory inputs that fine-tune stem cell behavior in the shoot meristem.