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        검색결과 154

        121.
        2013.08 서비스 종료(열람 제한)
        One of the most effective and safe therapeutic methods for treating vitiligo, mixed autologous keratinocytes (KCs) and melanocytes (MCs) cultures have been used for autologous cell transplantation. However, the present transplantation method is faced with a problem that may require a large amount of skin tissue and keratinocytes have limited culture potency. We have found previously that human adipose derived stromal cells (hASCs) from aspirated fat tissue could be used in place of KCs and sufficient amounts of hASCs for transplantation could be obtained by small amount of aspirated fat tissue. The present investigation was determined the effect of ASCs on ex vivo expansion MCs for transplantation. In addition, we examined for a preservation conditions of MCs which have reported low recovery rates and a slowdown in growth after cryopreservation. Various conditions including ASCs ratio, incubation period, and additive materials for MCs cultivation was determined to improve the expansion ability of MCs. The growth rate of MCs colony was elevated 6.85 folds compared the previous conditions. These MCs showed a specific expression of immature melanocyte protein, Trp-2, but did not express the mature melanocyte proteins and markers (c-kit, CD133, and etc.) of mesenchymal stem cells that represents in ASCs feeder. Results in cryopreservation experiments were determined a preservation medium for MCs showing an increased recovery rates after thawing. The characteristics of MCs after cryopreservation using a designed medium were indicated consistent morphology and immunophenotype. In conclusion, ASCs as a feeder could be used in place of keratinocytes for ex vivo expansion of MCs. For clinical trial for vitiligo patients, efficiency experiments in preclinical state should be followed.
        122.
        2013.08 서비스 종료(열람 제한)
        Pluripotent stem cells are cells that have a self-renewal capacity and the ability to differentiate into all lineages. These cells can be divided into naive- and primed-state pluripotent stem cells according to their pluripotent state. Only the naive state comprises a full pluripotency or ground state that contributes to germ-line transmission. Naive states are found in specific permissive strains or species, such as 129, C57BL/6 and BALB/C in mice. However, a number of attempts have been made to derive naive-state pluripotent stem cell lines from non-permissive species, including humans and pigs, using various exogenous factors including GSK3β and MEK inhibitors (2i), LIF, hypoxic conditions and up-regulation of Oct4 or Klf4. Therefore, in this study we investigated whether a naive pluripotent stem cell line could be derived from porcine embryonic fibroblasts (PEFs) via previously reported factors. Our mouse embryonic stem cell (mESC)-like cell lines expressed the pluripotency markers Oct4, Sox2 and Nanog and a stable mESC-like morphology for more than 50 passages. In addition, these cell lines could be sequentially reprogrammed into mESC-like induced pluripotent stem (iPS) cells from secondary or tertiary fibroblast-like cells differentiated from mESC-like iPS cells by addition of doxycycline (DOX), LIF and 2i. Our results suggest that, as a non-permissive species, porcine stem cells can be induced into mESC-like iPS cells from PEFs by various exogenous factors, including continuous transgene expression, 2i and LIF. However, further work that aims to effectively induce the activation of endogenous transcription factors is necessary to derive authentic naive-state pluripotent porcine stem cells.
        123.
        2013.08 서비스 종료(열람 제한)
        Anthocyanins are the largest group of water-soluble pigments in the plant kingdom. They are widely distributed in the human diet through crops, beans, fruits, vegetables and red wine. The specific health effects that anthocyanins might have in vivo are not known, although there are several possibilities related to obesity, cardiovascular disease, and cancer. In this study we used human subcutaneous adipose mesenchymal stem cells (hADSC) and mouse subcutaneous adipose mesenchymal stem cells (mADSC) to evaluate the effects of anthocyanins. And we examined the effect of cell activity and adipocyte differentiation by Cyanidin-3-O-glucoside (C3G), Delphinidin-3-ß-D-glucoside (D3G) that are among the anthocyanin family and black soybean extract. Using MTT assay method, we tested cellular metabolic activity. In mADSC, cell activity is significantly decreased by C3G and D3G (50 uM, 100 uM, and 200 uM), and black soybean extract (100 ug/ml and 200 ug/ml). In hADSC, cell activity is significantly decreased only by C3G (50 uM, 100 uM and 200 uM) unlike in mADSC. Cell activity is significantly increased of 100 uM D3G and black soybean extract (50 ug/ml, 100 ug/ml and 200 ug/ml). In mADSC, 50 uM C3G promoted differentiation into adipocyte but no effect in other concentration. D3G suppressed the differentiation of mADSC at 100 uM and 200 uM. 50 ug/ml black soybean extract promoted differentiation of mADSC, but 200 ug/ml black soybean extract suppressed differentiation. In hADSC, 50 uM, 100 uM and 200 uM C3G suppressed differentiation. 100 uM D3G promoted differentiation into adipocyte, but 200uM D3G suppressed it. Black soybean extract suppressed the differentiation into adipocyte at 50 ug/ml, 100 ug/ml and 200 ug/ml. These data showed that the responsibility to the C3G and D3G were different between hADSC and mADSC. Interestingly the responsibility to the black soybean extract was similar between hADSC and mADSC. Based on them, it is suggested that there are species-specificity to the cellular responsibility to the anthocyanins in subcutaneous ADSC.
        125.
        2013.03 서비스 종료(열람 제한)
        The transplantation of bone-marrow stem cells into the heart might restore viability after myocardial infarction, and the regenerative potentials of human autologous adult stem cells with respect to myocardial regeneration and neovascularization after myocardial infarction may contribute to healing in the infarcted areas. Here, we describe the results of this method in a patient with acute myocardial infarction who exhibited quantitative improvements in ventricular geometry and contractility. Furthermore, left ventricular ejection fraction and infarct area were improved at 3 month after stem cell transplantation as compared with baseline echocardiography and myocardial single photon emission computed tomography findings.
        127.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        Human embryonic stem (ES) cells are a potential source of cells for developmental studies and for a variety of applications in transplantation therapies and drug discovery. However, human ES cells are difficult to culture and maintain at a large scale, which is one of the most serious obstacles in human ES cell research. Culture of human ES cells on MEF cells after disassociation with accutase has previously been demonstrated by other research groups. Here, we confirmed that human ES cells (H9) can maintain stem cell properties when the cells are passaged as single cells under a feeder-free culture condition. Accutase-dissociated human ES cells showed normal karyotype, stem cell marker expression, and morphology. We prepared frozen stocks during the culture period, thawed two of the human ES cell stocks, and analyzed the cells after culture with the same method. Although the cells revealed normal expression of stem cell marker genes, they had abnormal karyotypes. Therefore, we suggest that accutase-dissociated single cells can be usefully expanded in a feeder-free condition but chromosomal modification should be considered in the culture after freeze-thawing.
        128.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to investigate the effects of Woohwangcheungsimweun (ox bezoar), deer antlers, and wild ginseng on induction of cardiomyocyte differentiation using the established mouse embryonic stem (ES) cells. The expression of atrial natriuretic peptide (ANP) was highest in Woohwangcheungsimweun treatment group. The expression of rabbit anti-GATA-4(GATA-4) and troponin (TnI) were highest in wild ginseng and Woohwangcheungsimweun treatment groups, respectively. Fluorescence activated cell sorting (FACS) analysis showed that the expression of ANP was highest in Dimethyl sulfoxide(DMSO) and Woohwangcheungsimweun treatment groups. The expression of GATA-4 was relatively high in wild ginseng treatment group. The expression of TnI was highest in Woohwangcheungsimweun treatment group. In the gene expression analysis, DMSO greatly inhibited GATA-4 expression to 25% of control. Woohwangcheungsimweun treatment caused to increase cTnI and cardiac ANP expression significantly. Wild ginseng extract upregulated GATA-4 gene expression. In conclusion, DMSO widely used as cardiomyocyte differentiation inducer did not show significant effects on the expression of ANP, GATA-4 and TnI in this study. Woohwangcheungsimweun showed upregulation of ANP and TnI expression. Wild ginseng extract showed greater effects than DMSO on GATA-4 expression. These results might suggest that the combination of Woohwangcheungsimweun and wild ginseng extract treatment can be expected to increase expressions of all three genes.
        129.
        2012.09 서비스 종료(열람 제한)
        Human embryonic stem cells (hESCs) are promising cell source because of their unique self-renewal and pluripotency. Although hESC-derived cardiac cells are currently generated worldwide, cryopreservation of these cells is still limited due to low rate of post-thaw survival. Cryopreservation of hESC-derived cardiac cells is critical in that their long-term storage can accelerate their use in regenerative medicine. However, to date, there are few reports on efficient cryopreservation and post-thaw survival of hESC-derived cardiac cells. In this study, we evaluated the effects of ginsenoside, which is known to improve survival of rat embryonic cardiomyocytes against myocardial ischemia injury in diabetic rats (Wu et al., 2011), on the survival of hESC-derived cardiac cells after thawing. We induced differentiation into cardiac cells using our previously reported method (Kim et al., 2011). Differentiated, pre-beating stage cardiac cells were cryopreserved using either mass cryopreservation or vitrification. To evaluate the effects of ginsenoside (Re, Rb), we compared three sets: pre- and post-thaw treatment, pre- or post-thaw treatment only. The survival of post-thaw cardiac cells were evaluated using Trypan-blue and Annexin V staining. In addition, the three groups were treated with ROCK inhibitor Y-27632, and compared with non-treatment groups. The effect of ginsenoside was significant in post-thaw treatment group, i.e, thawed cells expressed cardiac specific genes and showed specific functionality such as spontaneous beating. Taken together, we demonstrated favorable effects of ginsenoside on the survival of hESC-derived cardiac cells after cryopreservation and thawing. These results suggest a possible application of well-known cardioprotectant ginsenoside in cell-based tissue engineering using hESC-derived cardiac cells.
        130.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        Human eyelid adipose-derived stem cells (hEAs) and amniotic mesenchymal stem cells (hAMs) are very valuable sources for the cell therapeutics. Both types of cells have a great proliferating ability in vitro and a multipotency to differentiate into adipocytes, osteoblasts and chondrocytes. In the present study, we evaluated their stem cell characteristics after long-time cryopreservation for 6, 12 and 24 months. When frozen-thawed cells were cultivated in vitro, their cumulative cell number and doubling time were similar to freshly prepared cells. Also they expressed stem cell-related genes of SCF, NANOG, OCT4, and TERT, ectoderm-related genes of NCAM and FGF5, mesoderm/endoderm-related genes of CK18 and VIM, and immune-related genes of HLA-ABC and 2M. Following differentiation culture in appropriate culture media for 2-3 weeks, both types of cells exhibited well differentiation into adipocyte, osteoblast, and chondrocyte, as revealed by adipogenic, osteogenic or chondrogenic-specific staining and related genes, respectively. In conclusion, even after long-term storage hEAs and hAMs could maintain their stem cell characteristics, suggesting that they might be suitable for clinical application based on stem cell therapy.
        131.
        2011.09 서비스 종료(열람 제한)
        Estrogens are ubiquitous signaling molecules that influence nearly every cell type, and exert profound effects on embryonic development, and differentiation. Wnt pathway, which recruits β-catenin into nuclei, and activates The Wnt-dependent transcription factors, also plays an important role in embryonic development and stem cell maintenance, and differentiation. Accumulating evidences indicate that potential convergence between these two pathways in carcinoma cells. However, physiological roles of estrogens in development and differentiation of human embryonic stem cells (hESCs) are relatively unknown. Here, we demonstrated that estrogenic compounds 17α-ethinylestradiol (EE2) and genistein (GEN) significantly increased β-catenin expression in undifferentiated hESCs cultured in feeder-free media. Interestingly, GEN treatement induced an increased trend of mesendodermal gene expressions, and significantly inhibited ectodermal gene expressions (Nestin and Pax6) in embrioid body (EB). Expectantly, GEN increased epithelial-mesenchymal transition (EMT) related gene expression (Snail2, and Twist), whereas decreased E-cadherin on day 6 of EB development. Taken together, these suggest that estrogens may in part the powerful effects on normal hESC differentiation. Mechanistic studies of estrogen signaling continue to suggest novel drug targets for stem cells and will also improve screening methods of developmental toxicity.
        132.
        2011.09 서비스 종료(열람 제한)
        Hematopoietic stem cells (HSCs) can self-renew and can differentiate to a variety of specialized blood cells). The proliferation and homing of HSCs are strictly regulated both in the system level and local level. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor, potent species-specific stimulator of granulocyte-macrophage, eosinophil, megakaryocyte and erythroid progenitors. In clinical purpose GM-CSF has been used as hematopoietic growth factor. It can promote the mobilization of HSC from bone marrow to peripheral blood. The number of HSCs mobilized into blood can be modulated by the kinds of cytolines. However, the information for the cytokine which promote mobilization is limited. Basic fibroblast growth factor (bFGF or FGF-2) induces the change of niche and affects the maintenance and differentiation of HSCs. FGF-2 positively regulates hematopoiesis, by acting on stroma cells, on early and committed hematopoietic progenitors, and possibly on some mature blood cells. In this study, we investigated the effect of FGF-2 on HSCs mobilization and proliferation compare to GM-CSF. GM-CSF and FGF-2 were injected for 2 or 5 days into peritoneum of CD-1 mice (6~8 wks old) and sampling the bone marrow and peripheral blood. The bone marrow cells and peripheral blood were analyzed using FACS. In GM-CSF group, the number of HSCs was significantly increased by 2 days of injection but was significantly decreased in 5 days of injection. On the other hand the number of HSCs was significantly increased by the administration of FGF2 both in 2 days and 5 days. GM-CSF and FGF-2 are all increased the number of HSC both in bone marrow and peripheral blood. From these results, it is revealed that chronic administration of GM-CSF does not cause of the increase the number of HSCs. On the other hand, FGF2 can stimulate the proliferation of HSC without inhibition by the treatment period. It is suggested that GM-CSF and FGF2 may use different mechanisms to stimulate the HSCs proliferation. IP: 220.149.***.
        133.
        2011.09 서비스 종료(열람 제한)
        The human eyelid adipose-derived stem cells (HEACs) are known as a candidate source for stem cell-based therapy. HEACs possess the ability to proliferate in vitro and multipotency to differentiate into adipogenic, osteogenic and chondrogenic cells. To be used later than the time of collection, a long-term storage is needed. In this study, we investigated stem cell characteristics after cryopreservation of HEACs for 6 months and 1 year in liquid nitrogen. Frozen-thawed stem cells have shown that cumulative cell and doubling numbers were similar to those of fresh HEACs. After thawing, HEACs expressed stem cell-related genes of SCF, NANOG, OCT4, and TERT, ectoderm-related genes of NCAM and FGF5, mesoderm/endoderm-related genes of CK18 and VIM. They also consistently expressed transcripts of the immune-related genes of HLA-ABC and β2M. To induce mesodermal differentiation, cell were cultivated in adipogenic, osteogenic or chondrogenic medium for 2~3 weeks. After each differentiation culture, HEACs expressed adipocyte-, osteocyte- and chondrocytespecific genes. They were also stained with Oil red O, von Kossa, or alcian blue, revealing adipogenic, osteogenic, or chondrogenic character, respectively. The results suggest that long-term storage up to 1 year do not affect their biological properties, HEACs may be suitable for clinical application on cell-based therapies.
        134.
        2011.09 서비스 종료(열람 제한)
        The remarkable regenerative capacity of the adult liver provides a setting to test the functional consequences of grafting human cells generated from pluripotent stem cells. This presentation describes a procedure to differentiate hepatocytes from human embryonic stem and induced pluripotent stem cells using only defined factors. Two cell populations generated in vitro were grafted into the spleen of mice treated with the hepato-toxin carbon tetra-chloride. The population containing few hepatocytes generated few surviving cells that produced low levels of albumin and did not support regeneration of the host liver. The cells enriched in donor hepatocytes efficiently engrafted around the branches of the portal vein, expressed hepatic features for at least 5 weeks. These cells also contributed to the endogenous tissue regeneration and function of the host liver. These results show that the controlled differentiation of hepatocytes from human pluripotent cells provides new approaches to define the mechanisms of tissue regeneration and restore liver function.
        135.
        2010.12 KCI 등재 서비스 종료(열람 제한)
        Estrogen related receptor β(Esrrb)는 오르판 수용체 중 하나로 전분화능 관련유전자인 Oct4와 Nanog의 발현을 조절함으로써 줄기세포의 미분화를 유지시키고, 지속적인 자기 복제를 가능케 하는 유전자로 알려져 있다. 또한 Feng 등 (2009)은 체세포에 Oct4, Sox2와 함께 Esrrb 유전자를 함께 도입하면, 유전자가 변형된 체세포가 배아 줄기세포와 유사한 유도만능줄기세포로 리프로그래밍(reprograming)되어 진다는 결과를 보고한 바 있다. 본 연구에서는 인간 ESRRB 단백질을 양수유래줄기세포 내로 직접도입하는 방법을 개발하고, 이를 통해 전분화능 관련유전자의 기능 조절을 확인하고자 하였다. 클로닝 된 인간 short-form ESRRB를 세포투과 펩타이드(cell-penetrating peptide, CPP)의 일종인 R7(아르기닌 7개)에 접합(Fusion)하였고, 합성단백질 (R7-ESRRB-His6)의 형태로 배양중인 인간 양수 유래 줄기세포에 처리하여 세포내로 도입하였다. R7-ESRRB-His6 단백질은 5시간 내에 세포막을 통과하였고, 24시간 내에 핵 내로 이동하였다. 또한 핵 내로 이동한 ESRRB 단백질은 OCT4와 NANOG 유전자의 발현을 증가시켰을 뿐만 아니라, 또 다른 전분화능 관련유전자인 SOX2의 발현도 함께 증가시킨다는 것을 확인하였다. 이상의 결과는 세포투과 펩타이드와 유전자의 접합을 통해 생산된 R7-ESRRB-His6 합성단백질이 양수유래줄기세포내로 원활하게 도입되는 것을 확인하였고, 유전자의 변형 없이 전분화능 관련유전자의 기능을 조절할 수 있는 방법임을 확인하였다.
        136.
        2010.09 서비스 종료(열람 제한)
        Implantation of the blastocyst into the maternal endometrium, mediated by well-differentiated primary cells of the placenta known as trophoblasts, grow in an invasive via complicated interaction with immune cells in the maternal myometrium. Placenta-derived stem cells (PDSCs), which is a fetal origin, display multi-lineages differentiation potential, and they are free of ethical concerns, easily accessible, abundant, and strongly immunosuppressive. However, the efficiency of PDSCs according to trophoblast invasion or immune modulation in implantation has not yet been evaluated. Here, we investigated the effects of PDSCs for trophoblast invasion as well as their potential for immune modulation of activated T cells when they co-cultured with PDSCs. Activated T cells and HTR-8SV/neo trophoblast cells were co-cultured with PDSCs according to cell dose-dependent manner. Activities for proliferation of T cells were analyzed by BrdU incorporation assay and cell invasions were estimated. Activation of T cells was significantly decreased in the group co-cultured with PDSCs comparing to normal fibroblast cells (p<0.05). In addition, trophoblast invasion by PDSCs have recorded a twofold increase than the normal fibroblast cells. These results contribute to our understanding of the potential roles of PDSCs, including immune modulation effects for trophoblast invasion in pregnancy, and provide a foundation for the development of new cell therapy-based strategies for the treatment of women with implantation.
        137.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        최근 골수와 혈액으로 유래된 중간엽 줄기세포와 비슷한 능력을 가지는 것으로 알려진 지방 유래 중간엽줄기세포가 새로운 세포 치료제로 떠오르고 있다. 하지만 줄기세포를 이용하여 치료하려는 질병은 나이가 들어감에 따라 발병하는 퇴행성 질환들이 대부분인데, 노화가 진행됨에 따라 줄기세포의 능력이 차이가 있다고 알려져 있다. 이에 본 연구에서는 노화가 일어남에 따라 발생되는 신경성 질환을 자가 유래 지방 중간엽 줄기세포를 이용하여 치료함에 있어서 노화가 진행됨에
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