• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.4
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• pp.1017-1024
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• 2007

Thymus and activation-regulated chemokine (TARC/CCL-17), produced by keratinocytes, is a CC chemokine known to selectively Th2 type T cells via $CCR4^+$ and is implicated in the development of atopic dermatitis (AD). TARC/CCL17 expression was induced by cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interferon-${\gamma}$ (IFN-${\gamma}$). We recently found that the wogonin, a flavone isolated from Scutellaria baicalensis, suppressed TARC expression via heme oxygenase 1 (HO1) in human keratinocytes induced with mite antigen. However, little is known about the inhibitory mechanism of wogonin on TARC/CCL-17 expression stimulated with cytokines. To investigate the inhibitory mechanism, I determined the inhibitory effects of wogonin on the activation of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and $I{\kappa}B{\alpha}$ phosphorylation, and also examined the activation of p38 MAP kainase in HaCaT keratinocytes stimulated with TNF-${\alpha}$ and IFN-${\gamma}$. Wogonin inhibited NF-${\kappa}B$-DNA complex, NF-${\kappa}B$ binding activity, and the phosphorylation of $I{\kappa}B{\alpha}$ in a dose dependent manner. Wogonin also inhibited the translocation of NF-${\kappa}B$ from cytosol to nucleus. Moreover, the phosphorylation of of p38 MAP kinase in the TNF-${\alpha}$ and IFN-${\gamma}$-stimulated HaCaT keratinocytes were suppressed by wogonin in a dose dependent manner. These results suggest that wogonin may inhibit cytokine-induced NF-${\kappa}B$ activation by $I{\kappa}B{\alpha}$ degradation via suppression of p38 MAP kinase signaling pathway in keratinocytes and modulation of wogonin signaling pathway may be beneficial for the treatment of AD.

• Journal of Trauma and Injury
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• v.20 no.1
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• pp.1-5
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• 2007

Purpose: Grafting with autograft skin remains the most effective method for treating skin defects. When insufficient donor sites are present or patients are afraid of the operation, a skin graft is impossible. Cultured allogenic keratinocytes speed wound healing by providing cover and by producing growth factors and extracellular matrix protein. We report an application of cultured allogenic keratinocytes ($Kaloderm^{(R)}$, Tegoscience, Seoul, Korea) in the treatment of an acute partial thickness skin defect. Methods: From March 2005 to January 2006, 20 patients with a partial thickness skin defect were treated with cultured allogenic keratinocytes. The wound was covered with a sheet of cultured allogenic keratinocytes and ointment with $Bactigras^{(R)}$ gauze. The wound was inspected every two or three days. We regarded completion of epithelialization as wound healing. Results: The mean period between time of injury and time of $Kaloderm^{(R)}$ application was 7.5 days. The time taken from application of $Kaloderm^{(R)}$ to complete closure of the wounds was 7.2 days. Conclusion: In view of the favorable outcome, cultured allogenic keratinocytes are safe and effective biologic dressing materials for use in the treatment of open wounds.

• Genomics & Informatics
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• v.3 no.2
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• pp.66-72
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• 2005

The epidermis is a physiological barrier to protect organisms against environment. During the aging process, skin tissues undergo various changes including morphological and functional changes. The transcriptional regulation of genes is part of cellular reaction of aging process. In order to examine the changes of gene expression during the aging process, we used the primary cell culture system of human keratinocytes. Since UV radiation is the most important environmental skin aggressor, causing skin cancer and other problems including premature skin aging, we examined the changes of gene expression in human keratinocytes after UV irradiation using oligonucleotide microarray containing over 10,000 genes. We also compared the gene expression patterns of the senescent and UV treated cells. Expression of the variety of genes related to transcription factors, cell cycle regulation, immune response was altered in human keratinocytes. Some of down-regulated genes are represented in both senescent and UV treated cells. The results may provide a new view of gene expression following UVB exposure and aging process in human keratinocytes.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.1039-1049
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• 2023

Atopic dermatitis (AD) is a chronic inflammatory disease caused by immune dysregulation. Meanwhile, the supernatant of lactic acid bacteria (SL) was recently reported to have anti-inflammatory effects. In addition, HaCaT keratinocytes stimulated by tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) are widely used for studying AD-like responses. In this study, we evaluated the anti-inflammatory effects of SL from lactic acid bacteria (LAB) on TNF-α/IFN-γ-induced HaCaT keratinocytes, and then we investigated the strains' probiotic properties. SL was noncytotoxic and regulated chemokines (macrophage-derived chemokine (MDC) and thymus and activation-regulated chemokine (TARC)) and cytokines (interleukin (IL)-4, IL-5, IL-25, and IL-33) in TNF-α/IFN-γ-induced HaCaT keratinocytes. SL from Lacticaseibacillus rhamnosus MG4644, Lacticaseibacillus paracasei MG4693, and Lactococcus lactis MG5474 decreased the phosphorylation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK). Furthermore, the safety of the three strains was demonstrated via hemolysis, bile salt hydrolase (BSH) activity, and toxicity tests, and the stability was confirmed under simulated gastrointestinal conditions. Therefore, L. rhamnosus MG4644, L. paracasei MG4693, and Lc. lactis MG5474 have potential applications in functional food as they are stable and safe for intestinal epithelial cells and could improve atopic inflammation.

• Journal of Photoscience
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• v.9 no.2
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• pp.500-502
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• 2002

In vitro and in vivo studies have reported the induction of matrix metaloproteinase (MMP)-1 in the fibroblasts by ultraviolet (UV) A irradiation. We constructed the skin equivalent model using HaCaT cells as keratinocytes and human neonatal dennal fibroblasts as fibroblasts in the present study. The induction of MMP-l in the fibroblasts was confirmed immunohistochemically 6 hours after UVA irradiation using this model. This model was simply composed of human keratinocytes and fibroblasts. To our knowledge, there have been a few papers concerning the skin equivalent model in the field of photobiology. The effect of UVA exposure to fibroblasts through keratinocytes was examined using this model. The cross-talk can be examined between keratinocytes and fibroblasts. This model can be a useful tool in the field of photobiology.

• Biomolecules & Therapeutics
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• v.26 no.4
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• pp.417-423
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• 2018

Extracellular interleukin 1 alpha (IL-$1{\alpha}$) released from keratinocytes is one of the endpoints for in vitro assessments of skin irritancy. Although cells dying via primary skin irritation undergo apoptosis as well as necrosis, IL-$1{\alpha}$ is not released in apoptotic cells. On the other hand, active secretion has been identified in interleukin-1 receptor antagonist (IL-1ra), which was discovered to be a common, upregulated, differentially-expressed gene in a microarray analysis performed with keratinocytes treated using cytotoxic doses of chemicals. This study examined whether and how IL-1ra, particularly extracellularly released IL-1ra, was involved in chemically-induced keratinocyte cytotoxicity and skin irritation. Primary cultured normal adult skin keratinocytes were treated with cytotoxic doses of chemicals (hydroquinone, retinoic acid, sodium lauryl sulfate, or urshiol) with or without recombinant IL-1ra treatment. Mouse skin was administered irritant concentrations of hydroquinone or retinoic acid. IL-1ra (mRNA and/or intracellular/extracellularly released protein) levels increased in the chemically treated cultured keratinocytes with IL-$1{\alpha}$ and IL-$1{\beta}$ mRNAs and in the chemically exposed epidermis of the mouse skin. Recombinant IL-1ra treatment significantly reduced the chemically-induced apoptotic death and intracellular/extracellularly released IL-$1{\alpha}$ and IL-$1{\beta}$ in keratinocytes. Collectively, extracellular IL-1ra released from keratinocytes could be a compensatory mechanism to reduce the chemically-induced keratinocyte apoptosis by antagonism to IL-$1{\alpha}$ and IL-$1{\beta}$, suggesting potential applications to predict skin irritation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.308-315
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• 2004

Aim: The aim of this study was to investigate the mechanism of promoted skin wound healing in skin defects with primary cultured oral mucosal keratinocytes. Materials and methods: Thirty adult female nude mice weighing $20{\pm}2g$ were used for the experiment. Primary cultured and suspended oral mucosal keratinocytes, labeled with BrdU, were scattered onto $1.5cm{\times}1.5cm$ sized full thickness skin defects in the experimental group(N=15), and no grafts were placed the control group(N=15). They were sacrificed at 3 days, 1 week and 2 weeks after the treatment respectively. Histological examination of each wounds were performed to review the healing progress on measuring the length from the wound margin to regenerating epithelial front. The role of keratinocytes were assessed by double immunohistochemical staining with Anti-BrdU and Anti-cytokeratin AE1/3. Results: In the experimental group the wound was completely covered with regenerating epithelia in 2 weeks, but partially regenerated in the control group. The immunohistochemical studies unexpectedly reveal that most of regenerating epithelial cells were induced from marginal epithelium of the margin, not from the scattered keratinocytes. Conclusion: We could successfully confirm that graft of primary cultured oral mucosal keratinocytes promotes the regeneration of skin defects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.322-330
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• 2007

Backgrounds: To overcome limited amount of autogenous mucosa for the reconstruction of various mucosal defect including oral mucosal defect, tissue engineered mucosa has been recently introduced. However, introduced conventional technique of tissue engineered mucosa still have serious pitfalls such as long fabrication time, fragility of the reconstructed mucosa, and complexity of the technique. Aim of the study: To examine whether the complex of preconfluent autologous keratinocytes and autologous PRP(Platelet rich plasma) can reconstruct oral mucosa on the muscular flap with easier and faster way compared to conventional mucosal tissue engineering technique. Materials and methods: One day before the operation, oral mucosa(3mm in diameter) were taken and treated for extraction of oral keratinocytes according to the routine manner. The day of operation, oral keratinocytes were prepared in the laboratory and then moved to the operating theater. Autologous PRP was also prepared and then mixed with oral keratinocytes just before grafting on the prepared muscular flap. After keratinocyte-PRP complex was seated, then a sterilized rubber sheet was placed on the graft and the elevated skin flap was replaced and sutured. Biopsies were proceeded at 3, 5, 7, 14 and 21 days. Tissue samples were evaluated clinically, histologically, and immunohistochemically. Results: All of the oral keratinocyte-PRP complexes were successfully grafted on the recipient sites(100%). On 3 days after the operation, 1-2 continuous epithelial layer and many inflammatory cells were observed. On 5 days after the operation, increase of layers of keratinocyte was observed with less inflammatory response. Thickness of the layers was gradually increased from 7 to 21 days after the operation. Cytokeratin confirms epithelium in every specimen. Conclusions: Preconfluent graft of autogenous oral keratinocytes mixed with autogenous PRP have successfully reconstructed myo-mucosal flap. This technique could be a useful alternative for oral mucosal reconstruction in the near future.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.241-247
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• 2015

Ultraviolet (UV) radiation-induced loss of dermal extracellular matrix is associated with skin photoaging. Recent studies demonstrated that keratinocyte-releasable stratifin (SFN) plays a critical role in skin collagen metabolism by inducing matrix metalloproteinase 1 (MMP1) expression in target fibroblasts. In the present study, we examined whether SFN released from UVB-irradiated epidermal keratinocytes increases MMP1 release from dermal fibroblasts, and whether these events are affected by p-coumaric acid (p-CA), a natural phenolic compound with UVB-shielding and antioxidant properties. HaCaT cells were exposed to UVB in the absence and presence of p-CA, and the conditioned medium was used to stimulate fibroblasts in medium transfer experiments. The cells and media were analyzed to determine the expressions/releases of SFN and MMP1. UVB exposure increased SFN release from keratinocytes into the medium. The conditioned medium of UVB-irradiated keratinocytes increased MMP1 release from fibroblasts. The depletion of SFN using a siRNA rendered the conditioned medium of UVB-irradiated keratinocytes ineffective at stimulating fibroblasts to release MMP1. p-CA mitigated UVB-induced SFN expression in keratinocytes, and attenuated the MMP1 release by fibroblasts in medium transfer experiments. In conclusion, the present study demonstrated that the use of UV absorbers such as p-CA would reduce UV-induced SFN-centered signaling events involved in skin photoaging.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.5
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• pp.275-279
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• 2002

Nerve growth factor (NGF) is an important autocrine growth factor and also a survival factor for keratinocytes. NGF may act in the hyperproliferative condition, psoriasis. Clinically, the combination of psoralen and UVA (PUVA) has been used in the treatment of a wide variety of cutaneous disorders, such as psoriasis and vitiligo. However, the precise therapeutic mechanism of PUVA on the dermatologic diseases remains unclear. The purpose of this study was to examine whether the expression of NGF in cultured keratinocytes is influenced by PUVA. Thus, normal human keratinocytes were isolated from neonatal foreskin, and the third to fifth-passaged cells were used in this study. The cells were exposed to various doses of UVA (30, 60, 120 $mJ/cm^2)$ after adding 8-methoxypsoralen (8-MOP) to examine the expression of NGF mRNA. The RNA and protein of the cells were extracted at various time points (1, 8, 24 hours) after UVA irradiation to examine the expression of NGF mRNA and production of NGF protein. In keratinocytes, there were no differences in the expression of NGF mRNA between the different doses of UVA irradiation, however, the expression of NGF mRNA in UVA and PUVA groups tended to increase as the time increased. The expression of NGF mRNA was the highest in PUVA group, followed by UVA group and the lowest in 8-MOP group. The expressions of NGF protein at 1 and 8 hours after UVA irradiation were lower in the PUVA group than in the other groups. This study showed that the expression level of NGF protein in keratinocytes was relatively lower in the PUVA groups than in the other groups, suggesting that the therapeutic mechanism of PUVA in psoriasis is related to the decrease of NGF protein.