http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Derivation of putative brain endothelial cells from porcine induced pluripotent stem cells
Mirae Kim,Sang-Hwan Hyun 한국수정란이식학회 2017 한국수정란이식학회 학술대회 Vol.2017 No.05
The use of pigs in neuroscience has increased over the past years because the pigs are closely related to humans in terms of anatomy and physiology. Especially, the blood-brain barrier (BBB) maintains the homeostatic microenvironment in the central nervous system (CNS) and they can provide a valuable tool for studying the neurobiology. However, only a few putative blood-brain barrier (BBB) models have been generated by co-culture of porcine primary cells. The fundamental problem is that they lose some of their phenotypes when maintained in vitro for long-term culture. To establish improved in vitro porcine BBB models, we differentiated novel brain microvascular endothelial cells (BMECs) from porcine induced pluripotent stem cells (iPSCs) using a modified human-based protocol. Briefly, the dissociated single cells from iPSCs were seeded in Geltrex. For differentiation, cells were maintained for 3 days of expansion and then switched to unconditioned medium (UM) lacking bFGF for 6-7 days. Then, we subcultured cells onto collagen/fibronectin coated plates and changed BMEC medium for 2-3 weeks. About two weeks later, we observed a cluster of round cells surrounded by spindle shaped adherent cells termed as colony-forming units (CFU) of putative BMECs. Over time, the cluster of cells disappears and remained adherent spindle-shaped cells showed properties of endothelial cells. Although further studies will be needed, this study would be a great comparative analysis of the porcine and human in vitro BBB model.
Analysis of Transition Stage for Putative Canine Induced Pluripotent Stem Cells
Mirae Kim,Sang-Hwan Hyun 한국동물생명공학회(구 한국동물번식학회) 2018 발생공학 국제심포지엄 및 학술대회 Vol.2018 No.06
Canine induced pluripotent stem cells (ciPSCs) have great potential for veterinary regenerative medicine. To generate integration-free iPSCs from aged dog’s fibroblasts, canine adult fibroblasts (CAFs) were reprogrammed using an RNA-based strategy involving the non-integrating, self-replicating Venezuelan equine encephalitis (VEE) virus. Using this RNA system, CAFs were co-transfected with the T7-VEE-OKS-iG RNA replicon plus B18R mRNA for 4 h. Subsequently, the transfection medium was replaced with Advanced-Dulbecco’s modified Eagle’s medium (Advanced-DMEM) containing 10% fetal bovine serum and 200 ng/mL of the B18R protein. One day after the final transfection, cells were grown in stage 1 medium and selected with puromycin (0.5 μg/mL) until Day 10. On Day 11, the stage 1 medium was changed to mouse embryonic fibroblast- conditioned medium containing 20% KnockOut Serum Replacement (KSR) medium. Putative ciPSC colonies first appeared between Days 15 and 25. Interestingly, two distinct types of ciPSC colonies were identified, which showed TRA-1-60 expression or alkaline phosphatase activity. Furthermore, analysis of the gene-expression levels suggested that these putative ciPSCs were in a transition state. Although further studies will be needed, this study will contribute to the development of cell-based therapeutics for aged dogs.
Derivation of Canine induced Pluripotent Stem Cells using an Integration-Free Method
Mirae Kim,Seon-Ung Hwang,Sang-Hwan Hyun 한국동물생명공학회(구 한국동물번식학회) 2017 발생공학 국제심포지엄 및 학술대회 Vol.2017 No.10
Canine induced Pluripotent Stem Cells (iPSCs) can provide great potential for regenerative veterinary medicine and may assist in the development of new therapeutics and pre-clinical studies for both dogs and human. To date, there have been several reports on the generation of canine iPSCs using retroviral or lentiviral transduction of Yamanaka’s factors. However, there is no report of canine iPSCs generated by genomic integration-free methods. According to previous studies, a polycistronic and synthetic self-replicating RNA system was developed for generating human iPSCs by the RNA replicon of Venezuelan Equine Encephalitis (VEE) virus. The VEE replicon is a positive-sense and single-stranded RNA which is similar with cellular mRNA containing a 5’ cap and poly (A) tail. It is no potential for genomic DNA integration problems because it does not use a DNA intermediate. Here, we investigated to generate canine iPSCs by a single transfection of the VEE-reprogramming factor (VEE-RF) RNA. To generate integration- free canine iPSCs, the VEE-OKS-iG RNA that expresses four reprogramming ORFs (hOct4, hKlf4, hSox2 and hGlis1) was transfected. Also, B18R mRNA was co-transfected to reduce immune response by VEE replicon. Putative canine iPSC colonies first appeared between day 15-25. Interestingly, they have two distinct types of initial canine iPSC colonies. They were identified by immunohistochemistry of live cells using TRA-1-60 antibody and also showed clear alkaline phosphatase (AP) activity. Further study will be required to analyze the characterization for a clinical application, and the non-integrating and self-replicating VEE RNA replicon system has the potential to make a great contribution to generating clinically applicable canine iPSCs.
A software tool for integrated risk assessment of spent fuel transportation and storage
Mirae Yun,Robby Christian,김보경,Belal Almomani,Jaehyun Ham,이상훈,강현국 한국원자력학회 2017 Nuclear Engineering and Technology Vol.49 No.4
When temporary spent fuel storage pools at nuclear power plants reach their capacity limit, the spentfuel must be moved to an alternative storage facility. However, radioactive materials must be handledand stored carefully to avoid severe consequences to the environment. In this study, the risks of threepotential accident scenarios (i.e., maritime transportation, an aircraft crashing into an interim storagefacility, and on-site transportation) associated with the spent fuel transportation process were analyzedusing a probabilistic approach. For each scenario, the probabilities and the consequences were calculatedseparately to assess the risks: the probabilities were calculated using existing data and statistical models,and the consequences were calculated using computation models. Risk assessment software wasdeveloped to conveniently integrate the three scenarios. The risks were analyzed using the developedsoftware according to the shipment route, building characteristics, and spent fuel handling environment. As a result of the risk analysis with varying accident conditions, transportation and storage strategieswith relatively low risk were developed for regulators and licensees. The focus of this study was the riskassessment methodology; however, the applied model and input data have some uncertainties. Furtherresearch to reduce these uncertainties will improve the accuracy of this model.