• BMB Reports
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• v.50 no.11
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• pp.572-577
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• 2017

In most clinical applications, human mesenchymal stem cells (hMSCs) are expanded in large scale before their administration. Prolonged culture in vitro results in cellular senescence-associated phenotypes, including accumulation of reactive oxygen species (ROS) and decreased cell viabilities. Profiling of stem cell-related genes during in vitro expansion revealed that numerous canonical pathways were significantly changed. To determine the effect of selenocysteine (Sec), a rare amino acid found in several antioxidant enzymes, on the replicative senescence in hMSCs, we treated senescent hMSCs with Sec. Supplementation of Sec in the culture medium in late-passage hMSCs reduced ROS levels and improved the survival of hMSCs. In addition, a subset of key antioxidant genes and Sec-containing selenoproteins showed increased mRNA levels after Sec treatment. Furthermore, ROS metabolism and inflammation pathways were predicted to be downregulated. Taken together, our results suggest that Sec has antioxidant effects on the replicative senescence of hMSCs.

• Korean Journal of Veterinary Research
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• v.53 no.1
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• pp.37-42
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• 2013

Mesenchymal stem cells (MSCs) have ability to differentiate into multi-lineage cells, which confer a great promise for regenerative medicine to the cells. The aim of this study was to establish a method for isolation and characterization of adipose tissue-derived MSC (pAD-MSC) and bone marrow-derived MSC (pBM-MSC) in pigs. Isolated cells from all tissues were positive for CD29, CD44, CD90 and CD105, but negative for hematopoietic stem cell associated markers, CD45. In addition, the cells expressed the transcription factors, such as Oct4, Sox2, and Nanog by RT-PCR. pAD-MSC and pBM-MSC at early passage successfully differentiated into chondrocytes, osteocytes and adipocytes. Collectively, pig AD-MSC and BM-MSC with multipotency were optimized in our study.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.392-401
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• 2010

Introduction: Diabetes mellitus, as a major health problem for the elderly has been shown to alter the properties of the bone and impair bone healing around a titanium implant in both humans and animals. The aim of this study was to examine the effect of adipose-derived stem cells on the healing process around a titanium implant in streptozotocin-induced diabetic rats. Materials and Methods: Thirteen rats were divided into two groups: adipose-derived stem cells injected group and a control group. A titanium screw implant (diameter: 2.0 mm, length: 3.5 mm) was placed into both tibia of 13 rats: 13 right tibia as the control group and 13 left tibia as the experimental group. The rats were sacrificed at different intervals (1, 2, and 4 weeks) after implantation for histopathology observations and immunohistochemistric analysis. Results: The histopathological findings revealed earlier new formed bone in the experimental group than the control group. In particular, at 1 week after implantation, the experimental group showed more newly formed bone and collagen around the implant than the control group. In immunohistochemistric analysis, osteoprotegerin (OPG) expression in the experimental group increased early compared to that of the control group until 2 weeks after implantation. However, after 2 weeks, OPG expression in the experimental group was similar to OPG expression in the control group. The receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL) expression in the experimental group increased early compared to that of the control group, and then decreased at 2 weeks. After 2 weeks, the level of RANKL expression was similar in both groups. Conclusion: These results suggest that adipose-derived stem cells in implantation can promote bone healing around titanium, particularly in diabetes mellitus induced animals.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.383-390
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• 2016

Mesenchymal stem cells (MSCs) are multipotent stem cells that can be differentiated into a variety of cell types, including adipocytes, osteoblasts, chondrocytes, β-pancreatic islet cells, and neuronal cells. MSCs have been reported to exhibit immunomodulatory effects in many diseases. Many studies have reported that MSCs have distinct roles in modulating inflammatory and immune responses by releasing bioactive molecules. Exosomes are cell-derived vesicles present in biological fluids, including the blood, urine, and cultured medium of cell cultures. In this study, we investigated the immunomodulatory effects of mouse adipose tissue-derived MSCs (mAD-MSCs), cultured medium (MSC-CM) of mAD-MSCs, and mAD-MSC-derived exosomes (MSC-Exo) on lipopolysaccharide (LPS)-induced RAW 264.7 cells. We observed that the expression levels of IL-1β, TNF-α, and IL-10 were significantly increased in LPS-stimulated RAW 264.7 cells compared to those in LPS-unstimulated RAW 264.7 cells. Additionally, these values were significantly (p < 0.05) decreased in mAD-MSCs-RAW 264.7 cell co-culture groups, MSC-CM-treated groups, and MSC-Exo-treated groups. MSCs can modulate the immune system in part by secreting cytokines and growth factors. We observed that immunomodulatory factors such as IL-1β, TNF-α, and IL-10 were secreted by mAD-MSCs under co-culturing conditions of mAD-MSCs with activated RAW 264.7 cells. In addition, mAD-MSC-derived exosomes exhibited similar immunomodulatory effects in activated RAW 264.7 cells. Therefore, our results suggest that mAD-MSCs have an immunomodulatory function through indirect contact.

• Development and Reproduction
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• v.17 no.4
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• pp.409-420
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• 2013

Human serum (HS) has been reported to induce aggregation of human eyelid adipose-derived stem cells (HEACs) during high-density culture in vitro. The present study focused on the role of cell adhesion molecules and gelatinases during HS-induced aggregation of HEACs. HS-induced aggregation occurred between 9-15 days of culture. Cells aggregated by HS medium (HS-agg) showed stronger expression of ${\alpha}2$, ${\alpha}2B$, ${\alpha}X$, and CEACAM1 genes compared to non-aggregated cells in HS medium (HS-ex) or in control FBS-cultured cells. HS-agg were distinctly labeled with antibodies against ${\alpha}2$, ${\alpha}2B$, and ${\alpha}X$ proteins. Western blot results demonstrated that the two integrin proteins were greatly expressed in HS-agg compared to HS-ex and control FBS-cultured cells. Treatment of HEACs with anti-integrin ${\alpha}2$ antibody during culture in HS medium delayed aggregation formation. HS-agg exhibited strong expression of MMP1 and MMP9 compared to HS-ex or FBS-cultured cells. Conditioned media from HS-culture showed remarkable increase of MMP9 gelatinolytic activity in comparison to those from FBS-culture. However, there was no change of TIMP mRNA expression in relation to the HS-induced aggregation. Based on these results, it is suggested that integrin ${\alpha}2$, ${\alpha}2B$, and ${\alpha}X$, and MMP9 might play an important role in the HS-induced aggregation of HEACs.

• Archives of Plastic Surgery
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• v.38 no.2
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• pp.131-134
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• 2011

Purpose: Stem cells continue to receive research attention in the clinical fields, and adipose-derived stem cells (ADSCs) have been shown to be a good source raw material. Many plastic surgeons are researching the ADSC adipogenesis with a view of conducting clinical trials, and many attempts have been made to identify the factors that promote the adipogenesis of ADSCs, but comparatively few correlation studies have been undertaken to explore the relation between reactive oxygen species (ROS) and the ADSC adipogenesis. We undertook this study is to investigate the effects of ROS on ADSC adipogenesis. Methods: ADSCs were isolated and cultured from abdominal adipose tissue, and cultured in different media; 1) DMEM(control), 2) adipogenesis induction culture medium, 3) adipogenesis induction culture medium with ROS ($20{\mu}M/50{\mu}M\;H_2O_2$), 4) adipogenesis induction culture medium containing ROS ($20{\mu}M/50{\mu}M\;H_2O_2$) and antioxidant ($10{\mu}M/20{\mu}M$ Deferoxamine). We compared adipogenesis in these different media by taking absorbance measurements after Oil-Red O staining every 5 days. Results: After culturing for 20 days, significant differences were observed between these various culture groups. Absorbance results showed significantly more adipogenesis had occurred in media containing adipogenesis induction culture medium and $H_2O_2$ (in a $H_2O_2$ dose-dependently manner) than in media containing adipogenesis induction culture medium and no $H_2O_2$ (p<0.001). Furthermore, in media containing adipogenesis induction culture medium, $H_2O_2$, and antioxidant, absorbance results were significantly lower than in adipogenesis induction culture medium and $H_2O_2$ (p<0.001). Conclusion: These findings suggest that ROS promote the adipogenesis of ADSCs. We suggests that ROS could be used in the adipose tissue engineering to improve fat cell differentiation and implantable fat tissue organization.

• 대한생식의학회:학술대회논문집
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• 2006.06a
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• pp.172.2-172.2
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• 2006

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.323-328
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• 2010

Purpose: Adipose-derived stromal cells (ADSCs) are multipotent cells that have been found to promote wound healing through the process of angiogenesis and reepithelialization. Generally, it is well known that the antigenicity of ADSCs doesn't affect stem cell therapy. In this study, we investigated the effect of allogeneic ADSCs in the wound healing process by applying allogeneic ADSCs on the wound healing splint model of mice. Methods: Adipose tissue was harvested from the epididymal fat pads of BALB/c and C57BL/6 mice. Twenty four mice BALB/c were divided into three groups; control, isogeneic, and allogeneic groups. Two full thickness defects with 6 mm diameters were created on the back of BALB/c mice. $1{\times}10^6$ ADSCs from BALB/c mice were applied on the isogeneic group. In the allogeneic group, ADSCs from the C57BL/6 mice were applied. No cells were applied to the control group. The sizes of the wounds were evaluated in 3, 5, 7, 10, and 14 days after the wounds were applied, and tissues were harvested in 7 and 14 days for histological analysis. Results: Wound healing rates had showed significant increase in 10, and 14 days when the isogeneic group was compared to the control group, but the allogeneic group showed significantly decrease compared to the isogeneic group (p<0.05). Histological scores in the isogeneic group were significantly high, but significantly lower in the allogeneic group when compared to the isogeneic group in 2 weeks (p<0.05). In the isogeneic group, thick inflammatory cell infiltration with abundant capillaries were observed in 1 week, and thick epithelium with many large capillaries were observed in 2 weeks. Conclusion: When isogeneic ADSCs were applied to wounds, they presented a faster wound healing rate compared to controls and the allogeneic group. Unlike general stem cell therapy, these findings suggest that cell therapy targeted at enhancing wound healing may benefit from the use of ADSCs with identical antigenicity, as opposed to allogeneic or xenogenic ADSCs.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.187-195
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• 2007

The cord blood serves as a vehicle for the transportation of oxygen and nutrients to the fetus. In the past, the human cord blood has generally been discarded after birth. However, numerous studies have described the regenerative ability of the cord blood cells in various incurable diseases. The umbilical cord blood (UCB)-derived stem cells are obtained through non-invasive methods that are not harmful to both the mother and the fetus. Furthermore, the cord blood stem cells are more immature than the adult stem cells and expand readily in vitro. The mesenchymal stem cells (MSCs) have the capacity to differentiate in vitro into various mesodermal (bone, cartilage, tendon, muscle, and adipose), endodermal (hepatocyte), and ectodermal (neurons) tissues. This review describes the immunological properties of the human UCB-MSCs to assess their potential usefulness in the allogeneic transplantation for the regenerative medicine.

• Journal of Life Science
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• v.23 no.4
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• pp.471-478
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• 2013

Human adipose tissue-derived mesenchymal stem cells (hADSCs) have therapeutic potential, including the ability to self-renew and differentiate into multiple lineages. Understanding of molecular mechanisms of stem cell differentiation is important for improving the therapeutic efficacies of stem cell transplantation. In this study, we determined the role of nuclear factor of activated T cells (NFAT5) in the osteogenic differentiation of hADSCs. The down-regulation of NFAT5 expression by the transfection of a specific siRNA significantly inhibited osteogenic differentiation of hADSCs and decreased the activity of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-${\kappa}B$) promoter without affecting their proliferation and adipogenic differentiation. The inhibition of NFAT5 expression inhibited the basal and Tumor Necrosis Factor ${\alpha}$ (TNF-${\alpha}$) induced activation of NF-${\kappa}B$, but it did not affect TNF-${\alpha}$-induced degradation of the $I{\kappa}B$ protein. These findings indicate that NFAT5 plays an important role in the osteogenic differentiation of hADSCs through the modulation of the NF-${\kappa}B$ pathway.