• Journal of Biomedical Engineering Research
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• v.40 no.1
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• pp.1-6
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• 2019

Human mesenchymal stem cells (hMSC) are multipotent stromal cells that have great potential to differentiate into a variety of cell types such as osteocytes, chondrocytes, and myocytes. Although there have been many studies on their clinical availability, little is known about how intracellular signals can be modulated by topographic features of the extracellular matrix (ECM). In this study, we investigated whether and how microwavy-patterned extracellular matrix (ECM) could affect the signaling activity of focal adhesion kinase (FAK), a key cellular adhesion protein. The fluorescence resonance energy transfer (FRET)-based FAK biosensor-transfected cells are incubated on microwavy-patterned surfaces and then platelet derived growth factor (PDGF) are treated to trigger FAK signals, followed by monitoring through live-cell FRET imaging in real time. As a result, we report that PDGF-induced FAK was highly activated in cells cultured on microwavy-patterned surface with L or M type, while inhibited by H type-patterned surface. In further studies, PDGF-induced FAK signals are regulated by functional support of actin filaments, microtubules, myosin-related proteins, suggesting that PDGF-induced FAK signals in hMSC upon microwavy surfaces are dependent on cytoskeleton (CSK)-actomyosin networks. Thus, our findings not only provide new insight on molecular mechanisms on how FAK signals can be regulated by distinct topographical cues of the ECM, but also may offer advantages in potential applications for regenerative medicine and tissue engineering.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.678-686
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• 2007

Human mesenchymal stem cells(hMSC), that have been reported to be present in bone marrow, adipose tissues, dermis, muscles and peripheral blood, have the potential to differentiate along different lineages including those forming bone, cartilage, fat, muscle and neuron. Therefore, hMSC are attractive candidates for cell and gene therapy. The optimal conditions for hMSC expansion require medium supplemented with fetal bovine serum(FBS). Some forms of cell therapy will involve multiple doses, raising a concern over immunological reactions caused by medium-derived FBS proteins. Previously, we have shown that hADSC can be cultured in human serum(HS) during their isolation and expansion, and that they maintain their proliferative capacity and ability for multilineage differentiation and promote engraftment of peripheral blood-derived CD34 cells mobilized from bone marrow in NOD/SCID mice. In this study we determined whether hADSC grown in HS maintain surface markers expression similar with cells grown in FBS during culture expansion and compared gene expression profile by Affymetrix microarray. Flow cytometry analysis showed that HLA-DR, CD117, CD29 and CD44 expression in HS-cultured hADSC during culture expansion were similar with that in FBS-cultured cells. However, the gene expression profile in HS-cultured hADSC was significantly different from that in FBS-cultured cells. Therefore, these data indicated that HS-cultured hADSC should be used in vivo animal study of hADSC transplantation for direct extrapolation of preclinical data into clinical application.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.5
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• pp.380-390
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• 2004

Bone healing plays an important role in orthognathic and craniofacial surgery. Bone tissue repair and regeneration are regulated by an array of growth and morphogenetic factors. Bone formation and remodeling require continuous generation of osteoprogenitor cells from bone marrow stromal cells, which generate and respond to a variety of growth factors with putative roles in hematopoiesis and mesenchymal differentiation. In this study, the efficacy of a single application of hepatocyte growth factor to promote bone regeneration in 5-mm experimental calvarial defects of adult male rats was assessed histologically and immunohistochemically. The result of the experimental site were compared with those of the contralateral contral side. None of the control and experimental bone defects demonstrated complete bone closure. Bone regeneration was found close th the margine and central part of the defects. At 1, 2 weeks, there were found much significant cellural mitotic activity and many inflammatory cells and osteoblasts on the experimental site than control site. At 4, 6 weeks, new bone apposition was founded in both site but, more apposition was seen at experimental site. At 8, 12 weeks, also, some differences was found that more apposition of new bone and collagen fiber was seen on experimental site. Our results have some possibility that HGF do a early positive role to repair the bone defect. More study will be needed.

• Development and Reproduction
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• v.14 no.4
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• pp.233-241
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• 2010

Human adipose stem cells are an abundant, readily available population of multipotent progenitor cells that reside in adipose tissue and these cells have characteristics very similar to bone marrow mesenchymal stromal cells (BMMSCs). However, liposuction procedure, donor age, body mass index, and harvesting sites might generate differences in the initial cell population and the preparations are a heterogeneous mixture of precursors with different subsets. Therefore, in this study, we investigated the characteristics of human thigh adipose stem cells and the differentiation potential into mesodermal and endodermal lineage. Thigh adipose stem cells maintained fibroblast-like morphology similar to BM-MSCs and they underwent average 56.5 doublings and produced $5{\times}10^{22}$ cells. These cells expressed SCF, Oct4, nanog, vimentin, CK18, FGF5, NCAM, Pax6, BMP4, HNF4a, nestin, GATA4, HLA-ABC, and HLA-DR genes at p3 and they also expressed Oct4, Thy-1, FSP, vWF, vimentin, desmin, CK18, CD54, CD4, CD106, CD31, a-SMA, HLA-ABC proteins. Moreover, they could differentiate into mesodermal lineage cells such as adipocyte, osteoblast and chondrocyte. In addition, they also differentiated into insulin secreting cells in our culture condition. In conclusion, human thigh adipose stem cells retain proliferative potential and expression patterns similar to BM-MSCs and they also differentiate into various cell types. Thus, human thigh adipose stem cells might be useful alternative cell source for clinical application.

• The Journal of the Korean dental association
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• v.53 no.12
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• pp.935-948
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• 2015

목적: 법랑기질 유도체(EMD)가 사람 치주인대 줄기세포(hPDLSC)의 조직 형성능에 미치는 영향을 in vitro와 in vivo 분석 모델을 이용해 평가한다. 재료 및 방법: hPDLSC를 배양하여 운반체와 함께 면역 억제된 쥐 등에 이식하였다; (1)대조군: EMD 처치하지 않은 운반체에 심어진 hPDLSC군 ($EMD^-/hPDLSC^+$), (2)실험군: EMD 처치한 운반체에 심어진 hPDLSC군 ($EMD^+/hPDLSC^+$). 각 군당 5마리씩 시행하고 8주 후 희생하였다. 조직학적, 조직계측학적 분석을 통해 형성된 백악질의 면적과 백악세포의 수 그리고 샤피 섬유의 수를 계측하였으며 면역조직화학적 분석을 통해 백악질과 교원질 형성을 평가하였다. 또한 in vitro에서 hPDLSC의 수용성 교원질과 glycosaminoglycan 형성에 대한 EMD의 효과를 분석하였다. 결과: 조직학적 분석에서 교원질성 치주 인대 조직이 실험군에서 현저하게 많이 생성된 것을 관찰할 수 있었다. 형성된 백악질의 면적과 백악세포의 수는 군 간 차이가 없었으나, 새롭게 형성된 샤피 섬유의 수는 실험군에서 대조군보다 유의하게 많았다(p<0.05). 교원질 형성에 대한 면역조직 화학적 분석 결과, 실험군에서 I, III형 교원질과 hydroxyproline의 발현이 높았다. 또한 in vitro에서 hPDLSC에 의한 수용성 교원질과 glycosaminoglycan 형성이 EMD의 농도에 비례하여 증가하였다 (p<0.05). 결론: EMD는 hPDLSC에 의한 샤피 섬유 및 교원질 생성을 증가시키고, 이는 새로운 백악질의 기능적 부착과 치주조직 재생에 중요한 역할을 한다.

• Molecules and Cells
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• v.38 no.11
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• pp.941-949
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• 2015

Rheumatoid arthritis is a chronic inflammatory disease that leads to bone and cartilage erosion. The inhibition of osteoblast differentiation by the inflammatory factor TNF-${\alpha}$ is critical for the pathogenesis of rheumatoid arthritis. To modulate TNF-${\alpha}$ mediated inhibition of osteoblast differentiation is required to improve therapeutic efficacy of rheumatoid arthritis. Here, we explored the potential role of rocaglamide-A, a component of Aglaia plant, in osteoblast differentiation. Rocaglamide-A prevented TNF-${\alpha}$ mediated inhibition of osteoblast differentiation, and promoted osteoblast differentiation directly, in both C2C12 and primary mesenchymal stromal cells. Mechanistically, Rocaglamide-A inhibited the phosphorylation of NF-${\kappa}B$ component p65 protein and the accumulation of p65 in nucleus, which resulted in the diminished NF-${\kappa}B$ responsible transcriptional activity. Oppositely, overexpression of p65 reversed rocaglamide-A's protective effects on osteoblast differentiation. Collectively, rocaglamide-A protected and stimulated osteoblast differentiation via blocking NF-${\kappa}B$ pathway. It suggests that rocaglamide-A may be a good candidate to develop as therapeutic drug for rheumatoid arthritis associated bone loss diseases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.245-249
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• 2008

Epidermal growth factor is a single-chain polypeptide consisting of 53 amino acids and has a potent mitogenic activity that stimulates proliferation of various normal and neoplastic cells through the interaction with its specific receptor(epidermal growth factor receptor, EGFR). Pleomorphic adenoma is the most common salivary benign tumor and histologically, it contains the epithelial cell, the myo-epithelial cell and mesenchymal ingredient, which is various aspect. Adenoid cystic carcinoma is an infiltrative malignant salivary gland tumor with three different histological patterns: cribriform, tubular or solid. The tumor cell structure composed of modified myoepithelial cell, and basaloid cell. In this study, we used an immunohistochemical technique to investigate the expression of EGF in 6 specimens of adenoid cystic carcinoma and 10 specimens of pleomorphic adenoma taken from patients treated at Dept. of Oral and Maxillofacial Surgery, Dankook University. The results were as follows. 1. In pleomorphic adenoma, ductal structure and scattered spindle cells in hyalinized stroma, disclosing myxoid stroma and hyalin, cartilage formation were observed. Immunohistologically, weak EGF expression in ductal structure and negative in stromal area were observed. 2. Cribriform type of adenoid cystic carcinoma showed numerous pseudocyst surrounded by dark small neoplastic cells in the back-ground of fibrous connective tissue and moderate EGF expression of dark cells adjacent to pseudo lumen in cribriform pattern, while weak expression in other most cells. 3. Tubular type of adenoid cystic carcinoma showed numerous ductal pattern surrounded by two layered neoplastic cells in the back-ground of fibrous connective tissue and strong EGF expression in luminal cells of ductal structure, while weak expression in outer cells. From the results obtained, we suggest that EGF is mainly biosynthesized in cells forming duct like structures of tubulo-ductal type or cribriform adenoid cystic carcinoma and it may play a role, as a cell mitogen in adenoid cystic carcinoma growth.

• Molecules and Cells
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• v.42 no.12
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• pp.906-918
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• 2019

MicroRNA-223-3p (miR-223-3p) is one of the potential microRNAs that have been shown to alleviate inflammatory responses in pre-clinical investigations and is highly encased in exosomes derived from bone mesenchymal stem cells (MSC-exosomes). MSC-exosomes are able to function as carriers to deliver microRNAs into cells. Autoimmune hepatitis is one of the challenging liver diseases with no effective treatment other than steroid hormones. Here, we examined whether MSC-exosomes can transfer miR-223-3p to treat autoimmune hepatitis in an experimental model. We found that MSC-exosomes were successfully incorporated with miR-223-3p and delivered miR-223-3p into macrophages. Moreover, there was no toxic effect of exosomes on the macrophages. Furthermore, treatments of either exosomes or exosomes with miR-223-3p successfully attenuated inflammatory responses in the liver of autoimmune hepatitis and inflammatory cytokine release in both the liver and macrophages. The mechanism may be related to the regulation of miR-223-3p level and STAT3 expression in the liver and macrophages. These results suggest that MSC-exosomes can be used to deliver miR-223-3p for the treatment of autoimmune hepatitis.

• Molecules and Cells
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• v.42 no.11
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• pp.763-772
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• 2019

Periodontitis is characterized by the loss of periodontal tissues, especially alveolar bone. Common therapies cannot satisfactorily recover lost alveolar bone. Periodontal ligament stem cells (PDLSCs) possess the capacity of self-renewal and multilineage differentiation and are likely to recover lost alveolar bone. In addition, periodontitis is accompanied by hypoxia, and hypoxia-inducible $factor-1{\alpha}$ ($HIF-1{\alpha}$) is a master transcription factor in the response to hypoxia. Thus, we aimed to ascertain how hypoxia affects runt-related transcription factor 2 (RUNX2), a key osteogenic marker, in the osteogenesis of PDLSCs. In this study, we found that hypoxia enhanced the protein expression of $HIF-1{\alpha}$, vascular endothelial growth factor (VEGF), and RUNX2 ex vivo and in situ. VEGF is a target gene of $HIF-1{\alpha}$, and the increased expression of VEGF and RUNX2 proteins was enhanced by cobalt chloride ($CoCl_2$, $100{\mu}mol/L$), an agonist of $HIF-1{\alpha}$, and suppressed by 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1, $10{\mu}mol/L$), an antagonist of $HIF-1{\alpha}$. In addition, VEGF could regulate the expression of RUNX2, as RUNX2 expression was enhanced by human VEGF ($hVEGF_{165}$) and suppressed by VEGF siRNA. In addition, knocking down VEGF could decrease the expression of osteogenesis-related genes, i.e., RUNX2, alkaline phosphatase (ALP), and type I collagen (COL1), and hypoxia could enhance the expression of ALP, COL1, and osteocalcin (OCN) in the early stage of osteogenesis of PDLSCs. Taken together, our results showed that hypoxia could mediate the expression of RUNX2 in PDLSCs via $HIF-1{\alpha}$-induced VEGF and play a positive role in the early stage of osteogenesis of PDLSCs.

• Journal of Nutrition and Health
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• v.57 no.2
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• pp.171-184
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• 2024

Purpose: Although activating thermogenic adipocytes is a promising strategy to reduce the risk of obesity and related metabolic disorders, emerging evidence suggests that it is difficult to induce adipocyte thermogenesis in obesity. Therefore, this study aimed to investigate the regulation of adipocyte thermogenesis in diet-induced obesity. Methods: Adipose progenitor cells were isolated from the white and brown adipose tissues of control diet (CD) or high-fat diet (HFD) fed mice, and fully differentiated white and brown adipocytes were treated with β-agonists or 18-carbon fatty acids for β-adrenergic activation or peroxisome proliferator-activated receptor (PPAR) activation. Results: Compared to the CD-fed mice, the expression of uncoupling protein 1 (Ucp1) was lower in the white adipose tissue of the HFD-fed mice; however, this was not observed in the brown adipose tissue. The expression of peroxisome proliferator-activated receptor gamma (Pparg) was lower in the brown adipose progenitor cells isolated from HFD-fed mice than in those isolated from the CD-fed mice. Norepinephrine (NE) treatment exerted lesser effect on peroxisome proliferator-activated receptor-γ coactivator (Pgc1a) upregulation in white adipocytes derived from HFD-fed mice than those derived from CD-fed mice. Regardless which 18-carbon fatty acids were treated, the expression levels of thermogenic genes including Ucp1, Pgc1a, and positive regulatory domain zinc finger region protein 16 (Prdm16) were higher in the white adipocytes derived from HFD-fed mice. Oleic acid (OLA) and γ-linolenic acid (GLA) upregulated Pgc1a expression in white adipocytes derived from HFD-fed mice. Brown adipocytes derived from HFD-fed mice had higher expression levels of Pgc1a and Prdm16 compared to their counterparts. Conclusion: These results indicate that diet-induced obesity may downregulate brown adipogenesis and NE-induced thermogenesis in white adipocytes. Also, HFD feeding may induce thermogenic gene expression in white and brown primary adipocytes, and OLA and GLA could augment the expression levels.