• Korean Journal of Bronchoesophagology
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• v.7 no.1
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• pp.24-28
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• 2001

Background and Objectives： Heat shock protein(HSP) 27 is a member of the small HSP family that plays a part in the epithelial cell growth and differentiation, wound healing. apoptosis and cell protection against inflammatory cytotoxic mediators. The expression of HSP27 was investigated in normal laryngeal tissue and squamous cell carcinoma of the larynx. Materials and Methods : We studied expression of HSP27 by Western blot on 20 patients of laryngeal squamous cell carcinoma. Results： HSP27 expressed in all normal and cancer tissues. In 9 cases(45%), expression of HSP27 more prominent in cancer tissue. Statistically, there were no significant difference in the expression of HSP27 in normal and cancer tissue, clinical stage and tumor differentiation. Conclusion 45% of cancer tissues was more prominent than normal tissue. But further studies on expression of HSP27 in laryngeal cancer and relationship with clinical parameter should be done.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2006.10a
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• pp.78-78
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• 2006

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.243-249
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• 2010

Tissue engineered bone (TEB) can replace an autogenous bone graft requiring an secondary operation site as well as avoid complications like inflammation or infection from xenogenic or synthetic bone graft. Adult mesenchymal stem cells (MSC) for TEB are considered to have various ranges of differentiation capacity or multipotency by the donor site and age. This study examined the effect of age on proliferation capacity, differentiation capacity and bone morphogenetic protein-2 (BMP-2) responsiveness of human bone marrow stromal cells (hBMSC) according to the age. In addition, to evaluate the effect on enhancement for osteoblast differentiation, the hBMSC were treated with Trichostatin A (TSA) and 5-Azacitidine (5-AZC) which was HDAC inhibitors and methyltransferase inhibitors respectively affecting chromatin remodeling temporarily and reversibly. The young and old group of hBMSC obtained from the iliac crest from total 9 healthy patients, showed similar proliferation capacity. Cell surface markers such as CD34, CD45, CD90 and CD105 showed uniform expression regardless of age. However, the young group showed more prominent transdifferentiation capacity with adipogenic differentiation. The osteoblast differentiation capacity or BMP responsiveness was low and similar between young and old group. TSA and 5-AZC showed potential for enhancing the BMP effect on osteoblast differentiation by increasing the expression level of osteogenic master gene, such as DLX5, ALP. More study will be needed to determine the positive effect of the reversible function of HDAC inhibitors or methyltransferase inhibitors on enhancing the low osteoblast differentiation capacity of hBMSC.

• International Journal of Stem Cells
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• v.15 no.4
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• pp.347-358
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• 2022

Background and Objectives: The search for a suitable alternative for urethral defect is a challenge in the field of urethral tissue engineering. Induced pluripotent stem cells (iPSCs) possess multipotential for differentiation. The in vitro derivation of urothelial cells from mouse-iPSCs (miPSCs) has thus far not been reported. The purpose of this study was to establish an efficient and robust differentiation protocol for the differentiation of miPSCs into urothelial cells. Methods and Results: Our protocol made the visualization of differentiation processes of a 2-step approach possible. We firstly induced miPSCs into posterior definitive endoderm (DE) with glycogen synthase kinase-3𝛽 (GSK3𝛽) inhibitor and Activin A. We investigated the optimal conditions for DE differentiation with GSK3𝛽 inhibitor treatment by varying the treatment time and concentration. Differentiation into urothelial cells, was directed with all-trans retinoic acid (ATRA) and recombinant mouse fibroblast growth factor-10 (FGF-10). Specific markers expressed at each stage of differentiation were validated by flow cytometry, quantitative real-time polymerase chain reaction (qRT-PCR) assay, immunofluorescence staining, and western blotting Assay. The miPSC-derived urothelial cells were successfully in expressed urothelial cell marker genes, proteins, and normal microscopic architecture. Conclusions: We built a model of directed differentiation of miPSCs into urothelial cells, which may provide the evidence for a regenerative potential of miPSCs in preclinical animal studies.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.14-17
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• 1995

An in vitro construct of three dimensional artificial skin equivalent has been engineered using human cervical epithelial cells and human foreskin fibroblasts with a matrix of bovine type I collagen. Two cell lines were established from cervical uteri cancer tissues which have the HPV(human papillomavirus)18 genome. These two cell lines came from the same origin but have slight differencies in growth rate and tumorigenicity. The organotypic raft culturing of epithelial cells were accomplished at air-liquid interface. The differentiation related characteristics were examined by immunohistochemistry using monoclonal antibodies against EGFreceptor, cytokeratin 5/6/18 as proliferation markers and against filaggrin, involucrin, and cytokeratin 10/13 as differentiation marker. We have obtained the stratification and the differentiation in the artificial skin equivalent, and differentiation-related proteins were expressed more in the C3-artificial skin, and proteins of proliferation were expressed more in the C3N-artificial skin, relatively. We found that reconstituted artificial skin have the same characteristics of differentiation proteins of original tissue or cells of human body.

• Animal cells and systems
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• v.13 no.4
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• pp.363-370
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• 2009

Since vitamin $D_3$ is an important regulator of osteoblastic differentiation, a presently-established vitamin $D_3$-entrapped calcium phosphate film (VCPF) was evaluated for hard tissue engineering. The entrapped vitamin $D_3$ more rapidly induced bone nodule formation. To characterize the cellular events leading to regulations including faster differentiation, signal transduction pathways were investigated in osteoblastic MG63 cells at a molecular level. Major signaling pathways for MG63 cell proliferation including phosphatidylinositol-3-kinase, extracellular signal-regulated kinase, c-Jun N-terminal kinase and focal adhesion kinase pathways were markedly down-regulated when cells were cultured on calcium phosphate film (CPF) and VCPF. This agreed with our earlier observations of the immediate delay in proliferation of MG63 cells upon culture on CPF and VCPF. On the other hand, the p38 mitogen-activated protein kinase (p38 MAPK) and protein kinase A (PKA) pathways were significantly up-regulated on both CPF and VCPF. CPF alone could simulate differential behaviors of MG63 cells even in the absence of osteogenic stimulation and entrapment of vitamin $D_3$ within CPF further amplified the signal pathways, resulting in continued promotion of MG63 cell differentiation. Interplay of p38 MAPK and PKA signaling pathways likely is a significant event for the promotion of differentiation and mineralization of MG63 cells.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.268-268
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• 2006

Due to their multipotency, stem cells can differentiate into a variety of specialized cell types, such as chondrocytes, osteoblasts, myoblasts, and nerve cells. As an alternative to mature tissue cells, stem cells are of importance in tissue engineering and regenerative medicine. Since interactions between scaffold and cells play an important role in the tissue development in vitro, synthetic oligopeptides have been immobilized onto polymeric scaffolds to improve specific cell attachment and even to stimulate cell differentiation. In this study, chondrogenic differentiation of stem cells was evaluated using surface-modified PLLA scaffolds, i.e., either hydrophilic acrylic acid (AA)-grafted PLLA or RGD-immobilized one. Porous PLLA scaffolds were prepared using a gas foaming method, followed by plasma treatment and subsequent grafting of AA to introduce a hydrophilicity (PLLA-PAA). This was further processed to fix RGD peptide to make an RGD-immobilized scaffold (PLLA-PAA-RGD). Stem cells were seeded at $1{\times}10^{6}$ cells per scaffold and the cell-PLLA constructs were cultured for up to 4 weeks in the chondrogenic medium. Using these surface-modified scaffolds, adhesion, proliferation, and chondrogenic differentiation of stem cells were evaluated. The surface of PLLA scaffolds turned hydrophilic (water contact angle, 45 degrees) with both plasma treatment and AA grafting. The hydrophilicity of RGD-immobilized surface was not significantly altered. Cell proliferation rate on the either PLLA-PAA or PLLA-PAA-RGD surface was obviously improved, especially with the RGD-immobilized one as compared to the control PLLA one. Chondrogenic differentiation was clearly identified with Safranin O staining of GAG in the AA- or RGD-grafted PLLA substrates. This study demonstrated that modified polymer surfaces may provide better environment for chondrogenesis of stem cells.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1983-1988
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• 2012

Stem cell transplantation is emerging as a possible new treatment for liver cirrhosis, and recent animal studies have documented the benefits of stem cell therapy in a hepatic fibrosis model. However, the underlying mechanism of stem cell therapy is still unclear. Among the proposed mechanisms, the cell replacement mechanism is the oldest and most important, in which permanently damaged tissue can be replaced by normal tissue to restore function. In the present study, Cy5.5-labeled superparamagnetic iron oxide (SPIO) was used to label human mesenchymal stem cells. The uptake of fluorescently labeled nanoparticles enabled the detection and monitoring of the transplanted stem cells; therefore, we confirmed the direct incorporation and differentiation of SPIO into the hepatocyte-like transplanted stem cells by detecting human tyrosine aminotransferase (TAT), well-known enzymatic marker for hepatocyte-specific differentiation.

• Korean Journal of Pharmacognosy
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• v.46 no.4
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• pp.309-314
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• 2015

Periodontitis is a chronic inflammatory disease that is known to have the characteristics of destructed periodontal tissue. Anti-oxidant and anti-inflammatory effects of mulberry leaves in periodontal tissue is not well known until now. We investigated the effects of n-butanol extract of mulberry leaves on the lipopolysaccharide (LPS)-induced proinflammatory cytokines, such as $IL-1{\beta}$, IL-6, IL-8 and modulates osteogenic differentiation in periodontal ligament cells. The expression levels of Runx2, ALP and mRNA were increased by n-butanol extract of mulberry leaves at the concentration of $100{\mu}g/ml$ in periodontal ligament cells. n-Butanol extract of mulberry leaves extract reduced the range of pathophysiological processes, such as inflammation and increase in the level of osteogenic-related genes. These findings suggest that n-butanol extract of mulberry leaves has therapeutic effects on periodontitis and periodontal tissue regeneartion.

• Journal of Plant Biology
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• v.13 no.3
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• pp.17-19
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• 1970

Histological observation of micropore-originated haploid rice callus was reported previously. Present study was attempted to clarify the growth or development of the calli when they were transferred to differentiation media prepared exclusively for differentiation of plantlets. When the callus was transferred to differentiation medium, the cells and tissues became radially elongated. Meristematic tissues were present but few in number, and their structures were quite different from those grown in the propagaton medium. Differentiation of tracheid, chloroplast, and epidermis-like cell layer, and formation of gap in the callus tissue were more conspicuous in differentiation media. Approximately ten days after transfer of callus to differentiation medium, plantlet was formed.