• Journal of Plant Biotechnology
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• v.33 no.3
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• pp.195-207
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• 2006

Stem cells are the primordial, initial cells which usually divide asymmetrically giving rise to on the one hand self-renewals and on the other hand progenitor cells with potential for differentiation. Zygote (fertilized egg), with totipotency, deserves the top-ranking stem cell - he totipotent stem cell (TSC). Both the ICM (inner cell mass) taken from the 6 days-old human blastocyst and ESC (embryonic stem cell) derived from the in vitro cultured ICM have slightly less potency for differentiation than the zygote, and are termed pluripotent stem cells. Stem cells in the tissues and organs of fetus, infant, and adult have highly reduced potency and committed to produce only progenitor cells for particular tissues. These tissue-specific stem cells are called multipotent stem cells. These tissue-specific/committed multipotent stem cells, when placed in altered environment other than their original niche, can yield cells characteristic of the altered environment. These findings are certainly of potential interest from the clinical, therapeutic perspective. The controversial terminology 'somatic stem cell plasticity' coined by the stem cell community seems to have been proved true. Followings are some of the recent knowledges related to the stem cell. Just as the tissues of our body have their own multipotent stem cells, cancerous tumor has undifferentiated cells known as cancer stem cell (CSC). Each time CSC cleaves, it makes two daughter cells with different fate. One is endowed with immortality, the remarkable ability to divide indefinitely, while the other progeny cell divides occasionally but lives forever. In the cancer tumor, CSC is minority being as few as 3-5% of the tumor mass but it is the culprit behind the tumor-malignancy, metastasis, and recurrence of cancer. CSC is like a master print. As long as the original exists, copies can be made and the disease can persist. If the CSC is destroyed, cancer tumor can't grow. In the decades-long cancer therapy, efforts were focused on the reducing of the bulk of cancerous growth. How cancer therapy is changing to destroy the origin of tumor, the CSC. The next generation of treatments should be to recognize and target the root cause of cancerous growth, the CSC, rather than the reducing of the bulk of tumor, Now the strategy is to find a way to identify and isolate the stem cells. The surfaces of normal as well as the cancer stem cells are studded with proteins. In leukaemia stem cell, for example, protein CD 34 is identified. In the new treatment of cancer disease it is needed to look for protein unique to the CSC. Blocking the stem cell's source of nutrients might be another effective strategy. The mystery of sternness of stem cells has begun to be deciphered. ESC can replicate indefinitely and yet retains the potential to turn into any kind of differentiated cells. Polycomb group protein such as Suz 12 repress most of the regulatory genes which, activated, are turned to be developmental genes. These protein molecules keep the ESC in an undifferentiated state. Many of the regulator genes silenced by polycomb proteins are also occupied by such ESC transcription factors as Oct 4, Sox 2, and Nanog. Both polycomb and transcription factor proteins seem to cooperate to keep the ESC in an undifferentiated state, pluripotent, and self-renewable. A normal prion protein (PrP) is found throughout the body from blood to the brain. Prion diseases such as mad cow disease (bovine spongiform encephalopathy) are caused when a normal prion protein misfolds to give rise to PrP$^{SC}$ and assault brain tissue. Why has human body kept such a deadly and enigmatic protein? Although our body has preserved the prion protein, prion diseases are of rare occurrence. Deadly prion diseases have been intensively studied, but normal prion problems are not. Very few facts on the benefit of prion proteins have been known so far. It was found that PrP was hugely expressed on the stem cell surface of bone marrow and on the cells of neural progenitor, PrP seems to have some function in cell maturation and facilitate the division of stem cells and their self-renewal. PrP also might help guide the decision of neural progenitor cell to become a neuron.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.1017-1030
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• 2023

Fetal bovine serum (FBS), which contains various nutrients, comprises 20% of the growth medium for cell-cultivated meat. However, ethical, cost, and scientific issues, necesitates identification of alternatives. In this study, we investigated commercially manufactured serum-free media capable of culturing Hanwoo satellite cells (HWSCs) to identify constituent proliferation enhancing factors. Six different serum-free media were selected, and the HWSC proliferation rates in these serum-free media were compared with that of control medium supplemented with 20% FBS. Among the six media, cell proliferation rates were higher only in StemFlex^TM Medium (SF) and Mesenchymal Stem Cell Growth Medium DXF (MS) than in the control medium. SF and MS contain high fibroblast growth factor 2 (FGF2) concentrations, and we found upregulated FGF2 protein expression in cells cultured in SF or MS. Activation of the fibroblast growth factor receptor 1 (FGFR1)-mediated signaling pathway and stimulation of muscle satellite cell proliferation-related factors were confirmed by the presence of related biomarkers (FGFR1, FRS2, Raf1, ERK, p38, Pax7, and MyoD) as indicated by quantitative polymerase chain reaction, western blotting, and immunocytochemistry. Moreover, PD173074, an FGFR1 inhibitor suppressed cell proliferation in SF and MS and downregulated related biomarkers (FGFR1, FRS2, Raf1, and ERK). The promotion of cell proliferation in SF and MS was therefore attributed to FGF2, which indicates that FGFR1 activation in muscle satellite cells may be a target for improving the efficiency of cell-cultivated meat production.

• Journal of Life Science
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• v.21 no.12
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• pp.1726-1731
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• 2011

Human Stem Cell Factor (hSCF) is a cytokine that binds to the c-Kit receptor and plays an important role in hematopoiesis, spermatogenesis, and melanogenesis. To produce the human Stem Cell Factor (hSCF) recombinant protein, we constructed a germline transgenic silkworm using the piggyback vector. The expression of the hSCF gene was driven by the Drosophila heat shock protein 70 (dHsp70) promoter. 3XP3 promotor-driven EGFP was used as a marker which allowed us to rapidly distinguish the transgenic silkworm. A mixture of the donor and helper vector was micro-injected into 1,020 eggs of bivoltin silkworms, Keomokjam. We obtained approximately 22 G1 broods that were EGFP-positive. The expression of the hSCF gene in the transgenic silkworm was analyzed by SDS-PAGE and immunoblotting. Also, analysis of insertion sites into the silkworm genome using inverse PCR showed that exogenous DNA was inserted into the transgenic silkworm genome. These results show that successfully constructed transgenic silkworm expresses the hSCF recombinant protein.

• BMB Reports
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• v.52 no.5
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• pp.318-323
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• 2019

Mesenchymal stem cells (MSCs) are multipotent adult stem cells that present immunosuppressive effects in experimental and clinical trials targeting various rare diseases including inflammatory bowel disease (IBD). In addition, recent studies have reported tryptophanyl-tRNA synthetase (WRS) possesses uncanonical roles such as angiostatic and anti-inflammatory effects. However, little is known about the function of WRS in MSC-based therapy. In this study, we investigated if a novel factor, WRS, secreted from MSCs has a role in amelioration of IBD symptoms and determined a specific mechanism underlying MSC therapy. Experimental colitis was induced by administration of 3% DSS solution to 8-week-old mice and human umbilical cord blood-derived MSCs (hUCB-MSCs) were injected intraperitoneally. Secretion of WRS from hUCB-MSCs and direct effect of WRS on isolated $CD4^+$ T cells was determined via in vitro experiments and hUCB-MSCs showed significant therapeutic rescue against experimental colitis. Importantly, WRS level in serum of colitis induced mice decreased and recovered by administration of MSCs. Through in vitro examination, WRS expression of hUCB-MSCs increased when cells were treated with interferon-${\gamma}$ ($IFN-{\gamma}$). WRS was evaluated and revealed to have a role in inhibiting activated T cells by inducing apoptosis. In summary, $IFN-{\gamma}$-mediated secretion of WRS from MSCs has a role in suppressive effect on excessive inflammation and disease progression of IBD and brings new highlights in the immunomodulatory potency of hUCB-MSCs.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.147.1-147.1
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• 2001

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1407-1415
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• 2016

Isolation and culture of spermatogonial stem cells (SSCs) are attractive for production of genetic modified offspring. In the present study, buffalo spermatogonial stem-like cells were isolated, cultured and expression pattern of different germ cell marker genes were determined. To recover spermatogonia, testes from age 3 to 7 months of buffalo were decapsulated, and seminiferous tubules were enzymatically dissociated. Two types of cells, immature sertoli cell and type A spermatogonia were observed in buffalo testes in this stage. Germ cell marker genes, OCT3/4 (Pou5f1), THY-1, c-kit, PGP9.5 (UCHL-1) and Dolichos biflorus agglutinin, were determined to be expressed both in mRNA and protein level by reverse transcription polymerase chain reaction and immunostaining in buffalo testes and buffalo spermatogonial stem-like cells, respectively. In the following, when the isolated buffalo buffalo spermatogonial stem-like cells were cultured in the medium supplemented 2.5% fetal bovine serum and 40 ng/mL glial cell-derived neurotrophic factor medium, SSCs proliferation efficiency and colony number were significantly improved than those of other groups (p<0.05). These findings may help in isolation and establishing long term in vitro culture system for buffalo spermatogonial stem-like cells, and accelerating the generation of genetic modified buffaloes.

• Restorative Dentistry and Endodontics
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• v.45 no.2
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• pp.17.1-17.10
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• 2020

Objectives: Citation analysis provides a unique insight into how scientific interests and research trends have changed over time. The aim of this study was to report on the 50 top-cited papers in dental stem cell research using the Science Citation Index Expanded provided by the Web of Science database to determine the academic importance of each contribution. Materials and Methods: After the screening, article title and type, total citations and citations per year, publication journal, publication year, first and senior authors, country of origin, institution, and university of reprint author were documented for the 50 top-cited articles in dental stem cell research. Keyword analysis was performed to determine which keywords were most/least popular. Results: Top 50-cited articles were cited between 179 to 2,275 times. The majority of papers were published in 2008 and originated from the United States with the highest contribution from the National Institute of Dental & Craniofacial Research. Journal of Dental Research published the highest number of top-cited articles, followed by Stem Cells and Journal of Endodontics. The greatest number of articles was published by two individual authors, Shi and Gronthos. Among 197 unique keywords, dental pulp stem cells and mesenchymal stem cells were the most frequently used. Thirty-eight of the 50 most cited articles were original articles, and 37 of them were in the field of basic science. Conclusions: Basic science studies in dental stem cell research published in high impact factor journals had the highest citation rates.

• International Journal of Stem Cells
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• v.16 no.2
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• pp.135-144
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• 2023

Background and Objectives: Melanocyte (MC), derived from neural crest stem cell (NCSC), are involved in the production of melanin. The mechanism by which NCSC differentiates to MC remains unclear. N6-methyladenosine (m6A) modification was applied to discuss the potential mechanism. Methods and Results: NCSCs were isolated from hair follicles of rats, and were obtained for differentiation. Cell viability, tyrosinase secretion and activity, and transcription factors were combined to evaluated the MC differentiation. RT-qPCR was applied to determine mRNA levels, and western blot were used for protein expression detection. Total m6A level was measured using methylated RNA immunoprecipitation (MeRIP) assay, and RNA immunoprecipitation was used to access the protein binding relationship. In current work, NCSCs were successfully differentiated into MCs. Fat mass and obesity associated gene (FTO) was aberrant downregulated in MCs, and elevated FTO suppressed the differentiation progress of NCSCs into MCs. Furthermore, microphthalmia-associated transcription factor (Mitf), a key gene involved in MC synthesis, was enriched by FTO in a m6A modification manner and degraded by FTO. Meanwhile, the suppression functions of FTO in the differentiation of NCSCs into MCs were reversed by elevated Mitf. Conclusions: In short, FTO suppressed the differentiating ability of hair follicle-derived NCSCs into MCs by m6A modifying Mitf.

• BMB Reports
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• v.47 no.8
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• pp.424-432
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• 2014

The defining feature of Parkinson's disease is a progressive and selective demise of dopaminergic neurons. A recent report on Parkinson's disease animal model demonstrates that poly (ADP-ribose) (PAR) dependent cell death, also named parthanatos, is accountable for selective dopaminergic neuronal loss. Parthanatos is a programmed necrotic cell death, characterized by PARP1 activation, apoptosis inducing factor (AIF) nuclear translocation, and large scale DNA fragmentation. Besides cell death regulation via interaction with AIF, PAR molecule mediates diverse cellular processes including genomic stability, cell division, transcription, epigenetic regulation, and stress granule formation. In this review, we will discuss the roles of PARP1 activation and PAR molecules in the pathological processes of Parkinson's disease. Potential interaction between PAR molecule and Parkinson's disease protein interactome are briefly introduced. Finally, we suggest promising points of therapeutic intervention in the pathological PAR signaling cascade to halt progression in Parkinson's disease.

• Journal of Life Science
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• v.24 no.12
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• pp.1301-1307
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• 2014

Adipose-derived stem cells (ADSCs) are considered promising tools for tissue regeneration. However, ADSCs have very poor proliferation capacity. Therefore, fetal bovine serum (FBS) is generally added to the culture media of ADSCs. As FBS contains many uncharacterized components that may affect cellular functions, methods for serum-free cultures of ADSCs have been widely investigated. In this study, to develop an efficient method for a serum-free culture of ADSC-T, we used an ADSC line established by introducing the simian virus 40 (SV40) T gene into primary ADSCs. We then investigated the effect of amino acids, vitamins, and other components on the growth of ADSC-T. When the ADSC-T cells were plated with DMEM/F12 serum-free medium, the cells did not proliferate, and the mixture of amino acids, vitamins, and B27 supplement did not increase the growth of the cells. However, when the ADSC-T cells were provided with serum-free DMEM/F12 after they had been cultured with serum-supplemented DMEM for 24 h, the cells proliferated, and the vitamins and B27 supplement increased the cell growth. Stem-Pro serum-free medium also appeared to be useful as a suspension culture for the ADSC-T cells. The ADSC-T cells secreted large amounts of proteins of around 70 kDa. Insulin-like growth factor (IGF) and fibroblast growth factor basic (FGF basic) were secreted by ADSC-T in larger amounts in the serum-free culture than in the serum-supplemented culture.