• BMB Reports
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• 제54권9호
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• pp.464-469
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• 2021

Cardiomyocyte differentiation occurs through complex and finely regulated processes including cardiac lineage commitment and maturation from pluripotent stem cells (PSCs). To gain some insight into the genome-wide characteristics of cardiac lineage commitment, we performed transcriptome analysis on both mouse embryonic stem cells (mESCs) and human induced PSCs (hiPSCs) at specific stages of cardiomyocyte differentiation. Specifically, the gene expression profiles and the protein-protein interaction networks of the mESC-derived platelet-derived growth factor receptor-alpha (PDGFRα)⁺ cardiac lineage-committed cells (CLCs) and hiPSC-derived kinase insert domain receptor (KDR)⁺ and PDGFRα⁺ cardiac progenitor cells (CPCs) at cardiac lineage commitment were compared with those of mesodermal cells and differentiated cardiomyocytes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the genes significantly upregulated at cardiac lineage commitment were associated with responses to organic substances and external stimuli, extracellular and myocardial contractile components, receptor binding, gated channel activity, PI3K-AKT signaling, and cardiac hypertrophy and dilation pathways. Protein-protein interaction network analysis revealed that the expression levels of genes that regulate cardiac maturation, heart contraction, and calcium handling showed a consistent increase during cardiac differentiation; however, the expression levels of genes that regulate cell differentiation and multicellular organism development decreased at the cardiac maturation stage following lineage commitment. Additionally, we identified for the first time the protein-protein interaction network connecting cardiac development, the immune system, and metabolism during cardiac lineage commitment in both mESC-derived PDGFRα⁺ CLCs and hiPSC-derived KDR⁺PDGFRα⁺ CPCs. These findings shed light on the regulation of cardiac lineage commitment and the pathogenesis of cardiometabolic diseases.

• 생체재료학회지
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• 제22권4호
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• pp.311-318
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• 2018

Background: Tissue regeneration includes delivering specific types of cells or cell products to injured tissues or organs for restoration of tissue and organ function. Stem cell therapy has drawn considerable attention since transplantation of stem cells can overcome the limitations of autologous transplantation of patient's tissues; however, it is not perfect for treating diseases. To overcome the hurdles associated with stem cell therapy, tissue engineering techniques have been developed. Development of stem cell technology in combination with tissue engineering has opened new ways of producing engineered tissue substitutes. Several studies have shown that this combination of tissue engineering and stem cell technologies enhances cell viability, differentiation, and therapeutic efficacy of transplanted stem cells. Main body: Stem cells that can be used for tissue regeneration include mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells. Transplantation of stem cells alone into injured tissues exhibited low therapeutic efficacy due to poor viability and diminished regenerative activity of transplanted cells. In this review, we will discuss the progress of biomedical engineering, including scaffolds, biomaterials, and tissue engineering techniques to overcome the low therapeutic efficacy of stem cells and to treat human diseases. Conclusion: The combination of stem cell and tissue engineering techniques overcomes the limitations of stem cells in therapy of human diseases, and presents a new path toward regeneration of injured tissues.

• BMB Reports
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• 제55권9호
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• pp.453-458
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• 2022

Diabetes mellitus (DM) is a serious disease in which blood sugar levels rise abnormally because of failed insulin production or decreased insulin sensitivity. Although many studies are being conducted for the treatment or early diagnosis of DM, it is not fully understood how mitochondrial genome (mtDNA) abnormalities appear in patients with DM. Here, we induced iPSCs from fibroblasts, PBMCs, or pancreatic cells of three patients with type 2 DM (T2D) and three patients with non-diabetes counterpart. The mtDNA mutations were detected randomly without any tendency among tissues or patients. In T2D patients, 62% (21/34) of iPSC clones harbored multiple mtDNA mutations, of which 37% were homoplasmy at the 100% mutation level compared to only 8% in non-diabetes. We next selected iPSC clones that were a wild type or carried mutations and differentiated into pancreatic cells. Oxygen consumption rates were significantly lower in cells carrying mutant mtDNA. Additionally, the mutant cells exhibited decreased production of insulin and reduced secretion of insulin in response to glucose. Overall, the results suggest that screening mtDNA mutations in iPSCs from patients with T2D is an essential step before pancreatic cell differentiation for disease modeling or autologous cell therapy.

• 한국동물생명공학회지
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• 제37권2호
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• pp.67-79
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• 2022

Currently, there is no treatment to reverse or cure heart failure caused by ischemic heart disease and myocardial infarction despite the remarkable advances in modern medicine. In addition, there is a lack of evidence regarding the existence of stem cells involved in the proliferation and regeneration of cardiomyocytes in adult hearts. As an alternative solution to overcome this problem, protocols for differentiating human pluripotent stem cell (hPSC) into cardiomyocyte have been established, which further led to the development of cell therapy in major leading countries in this field. Recently, clinical studies have confirmed the safety of hPSC-derived cardiac progenitor cells (CPCs). Although several institutions have shown progress in their research on cell therapy using hPSC-derived cardiomyocytes, the functions of cardiomyocytes used for transplantation remain to be those of immature cardiomyocytes, which poses a risk of graft-induced arrhythmias in the early stage of transplantation. Over the last decade, research aimed at achieving maturation of immature cardiomyocytes, showing same characteristics as those of mature cardiomyocytes, has been actively conducted using various approaches at leading research institutes worldwide. However, challenges remain in technological development for effective generation of mature cardiomyocytes with the same properties as those present in the adult hearts. Therefore, in this review, we provide an overview of the technological development status for maturation methods of hPSC-derived cardiomyocytes and present a direction for future development of maturation techniques.

• BMB Reports
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• 제45권12호
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• pp.713-718
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• 2012

Gangliosides play important roles in the control of several biological processes, including proliferation and transmembrane signaling. In this study, we demonstrate the effect of ganglioside GM1 on the proliferation of mouse induced pluripotent stem cells (miPSCs). The proliferation rate of miPSCs was lower than in mouse embryonic stem cells (mESCs). Fluorescence activated cell sorting analysis showed that the percentage of cells in the G2/M phase in miPSCs was lower than that in mESCs. GM1 was expressed in mESCs, but not miPSCs. To confirm the role of GM1 in miPSC proliferation, miPSCs were treated with GM1. GM1-treated miPSCs exhibited increased cell proliferation and a larger number of cells in the G2/M phase. Furthermore, phosphorylation of mitogen-activated protein kinases was increased in GM1-treated miPSCs.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2001년도 제18차 정기총회 및 학술발표 PROCEEDINGS
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• pp.40-46
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• 2001

The use of pluripotent stem cells has tremendous advantages for various purposes but these cell lines with proven germ-line transmission have been completely established only in the mouse. Embryonic germ (EG) cell lines are also pluripotent and undifferentiated stem cells established from primordial germ cells (PGCs). This study was conducted to establish and characterize the chicken EG cells derived from gonadal primordial germ cells. We isolated gonadal PGCs from 5.5-day-old (stage 28) White leghorn (WL) embryos and established chicken EG cells lines with EG culture medium supplemented with human stem cell factor (hSCF), murine leukemia inhibitory factor (mLIF), bovine basic fibroblast growth factor (bFGF), human interleukin-11 (hIL-11), and human insulin-like growth factor-I (hIGF-I). These cells grew continuously for 4 months (10 passages) on a feeder layer of mitotically active chicken embryonic fibroblasts. These cells were characterized by screening with the Periodic acid-Shiff＇s reaction, anti-SSEA-1 antibody, and a proliferation assay after several passages. As the results, the chicken EG cells maintained characteristics of undifferentiated stem cells as well as that of gonadal PGCs. When cultured in suspension, the chicken EG cells successfully formed an embryoid body and differentiated into a variety of cell types when re-seeded onto culture dish. The chicken EG cells were injected into blastodermal layer at stage X and dorsal aorta of recipient embryo at stage 14 (incubation of 53hrs) and produced chimeric chickens with various differentiated tissues derived from the EG cells. The germline chimeras were also successfully induced by using EG cells. Thus, Chicken EG cells will be useful for the production of transgenic chickena and for studies of germ cell differentiation and genomic imprinting.

• Molecules and Cells
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• 제44권11호
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• pp.851-860
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• 2021

Label-free optical diffraction tomography (ODT), an imaging technology that does not require fluorescent labeling or other pre-processing, can overcome the limitations of conventional cell imaging technologies, such as fluorescence and electron microscopy. In this study, we used ODT to characterize the cellular organelles of three different stem cells-namely, human liver derived stem cell, human umbilical cord matrix derived mesenchymal stem cell, and human induced pluripotent stem cell-based on their refractive index and volume of organelles. The physical property of each stem cell was compared with that of fibroblast. Based on our findings, the characteristic physical properties of specific stem cells can be quantitatively distinguished based on their refractive index and volume of cellular organelles. Altogether, the method employed herein could aid in the distinction of living stem cells from normal cells without the use of fluorescence or specific biomarkers.

• 생명과학회지
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• 제30권4호
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• pp.394-401
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• 2020

배아줄기세포는 만능세포이기 때문에 동물에게 주입되면 종양으로 발달할 수도 있다. 따라서 연구자들은 종양 형성으로부터 비교적 자유로운 성체세포로부터 세포 특이적 줄기세포(성체줄기세포)를 확보하는데 관심을 두고 있다. 성체줄기세포는 제한적으로 세포분열을 할 수 있고 지정된 특정 세포로만 발달할 수 있다. 포유동물에서 각 조직의 세포들은 자연적 생리조건하에서는 역분화 혹은 교차분화에 의해 성체줄기세포로 전환되지 않는다. 따라서 일본 연구자들에 의하여 2006년 성체세포의 리프로그램에 의한 유도만능줄기세포(iPSCs) 기술이 소개되어 성체줄기세포 연구의 새로운 장을 열었다. 비록 연구현장에서 iPSCs 기술이 폭 넓게 이용되지만, 리프로그램의 안정성뿐만 아니라 유전체에 외래유전자의 도입 등의 문제점도 있다. Reversine은 iPSCs 보다 2년 앞서 발견된 작은 화학적 합성 분자인 퓨린 유사체이다. Reversine은 분화된 세포를 리프로그램에 의한 역분화를 유도하여 다능성 줄기세포로 전환시킬 수 있으며, 적절한 분화조건하에서 다른 세포로 교차분화를 유도할 수도 있다. 따라서 reversine은 iPSCs가 가지고 있는 문제점을 극복하고 화학적인 방법을 이용하여 성체세포를 다능성 줄기세포로 전환시킬 수 있는 물질로 활용될 수 있다. Reversine이 백색지방세포를 갈색지방형세포(beige cell)로 전변시켜 열발산에 의한 에너지소비를 촉진함을 제시하여 항비만인자로서 그 가능성을 열어 놓았다. Reversine은 세포 역분화의 기능적 역할 이외에 항암 인자로서 또 다른 기능들이 보고되고 있어 앞으로 여러 분야에서 그 이용성이 기대되는 물질이다.

• BMB Reports
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• 제52권6호
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• pp.349-359
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• 2019

After the first research declaring the generation of human induced pluripotent stem cells (hiPSCs) in 2007, several attempts have been made to model neurodegenerative disease in vitro during the past decade. Parkinson's disease (PD) is the second most common neurodegenerative disorder, which is mainly characterized by motor dysfunction. The formation of unique and filamentous inclusion bodies called Lewy bodies (LBs) is the hallmark of both PD and dementia with LBs. The key pathology in PD is generally considered to be the alpha-synuclein (${\alpha}$-syn) accumulation, although it is still controversial whether this protein aggregation is a cause or consequence of neurodegeneration. In the present work, the recently published researches which recapitulated the ${\alpha}$-syn aggregation phenomena in sporadic and familial PD hiPSC models were reviewed. Furthermore, the advantages and potentials of using patient-derived PD hiPSC with focus on ${\alpha}$-syn aggregation have been discussed.

• Asian-Australasian Journal of Animal Sciences
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• 제22권1호
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• pp.26-34
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• 2009

Porcine embryonic stem (ES) cells have a great potential as tools for transgenic animal production and studies of regulation of differentiation genes. Although several studies showed successful derivation of porcine ES-like cells, these cells were not maintained long-term in culture. Therefore, this study was conducted to establish porcine pluripotent ES-like cells using in vivo fertilized embryos and to maintain these cells in long term culture. Porcine ES-like cells from in vivo embryos obtained by immunosurgery or whole explant culture were successfully cultured for over 56 passages. Morphology of porcine ES-like cells was flat-shaped with a monolayer type colony. These cells stained for alkaline phosphatase throughout the culture. Furthermore, porcine ES-like cells reacted with antibodies against Oct-4, SSEA-1, SSEA-4, Tra-1-60, and Tra-1-81, which are typical markers of undifferentiated stem cells. To characterize the ability of porcine ES-like cells to differentiate into three germ layers, embryoid body formation was induced. After plating of these cells, porcine ES-like cells were spontaneously differentiated into various cell types of all three germ layers. In addition, porcine ES-like cells were successfully derived from IVF blastocysts in media containing human recombinant basic fibroblast growth factor.