• The Korean Journal of Physiology and Pharmacology
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• 제25권1호
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• pp.15-26
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• 2021

Peptides are short chain of amino acids linked by peptide bonds. They are widely used as effective and biocompatible active ingredients in cosmetic industry. In this study, we developed novel peptide mixture and identified its anti-pigmentation effect on melanocytes and keratinocytes. Our results revealed that peptide mixture inhibited melanosome biogenesis through the regulation of microphthalmia-associated transcription factor, a key factor of melanogenesis in melanocytes. And we observed that peptide mixture inhibited melanosome uptake through the reduction of protease-activated receptor 2, a phagocytosis-related receptor in keratinocytes. Furthermore, peptide mixture activated autophagy system resulting in degradation of transferred melanosomes in keratinocytes. The anti-pigmentation effect of multi-targeting peptide mixture was assessed in a human skin equivalent model (MelanoDerm). Melanin contents in epidermal layer were significantly decreased by topical treatment of peptide mixture, suggesting that it can be applied as a novel cosmetics material having a whitening function.

• Toxicological Research
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• 제22권3호
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• pp.283-291
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• 2006

The survival and growth of epithelial cells depends on adhesion to the extracellular matrix. An adhesion signal may regulate the initiation of differentiation, since epidermal keratinocytes differentiate as they leave the basement membrane. A metabolically dead cornified cell envelope is the end point of epidermal differentiation so that this process may be viewed as a specialized form of programmed cell death. In order to investigate the precise cellular signaling events loading to terminal differentiation of keratinocytes, we have utilized HaCaT cells to monitor the biological consequences of $Ca^{2+}$ stimulation and numerous downstream signaling pathways, including activation of the extracellular signal-regulated protein kinase(ERK) pathway and activation of phosphatidylinositol 3-kinase(PI3K). The results presented in this study show that $Ca^{2+}$ function as potent agents for the differentiation of HaCaT keratinocytes, and this differentiation depends or the activation of ERK, Protein kinase B(PKB) and p70 ribosomal protein S6 kinase(p70S6K). Finally, the results show that the expression of Activator protein 1(AP-1; c-Jun and c-Fos) increased following $Ca^{2+}$-mediated differentiation of HaCaT cells, suggesting that ERK-mediated AP-1 expression is critical for initiating the terminal differentiation of keratinocytes.

• The Korean Journal of Physiology and Pharmacology
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• 제12권4호
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• pp.177-183
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• 2008

The layers of keratinocytes form an acid mantle on the surface of the skin. Herein, we investigated the effects of acidic pH on the membrane current and $[Ca^{2+}]_c$ of human primary keratinocytes from foreskins and human keratinocyte cell line (HaCaT). Acidic extracellular pH ($pH_e{\leq}5.5$) activated outwardly rectifying $Cl^-$ current ($I_{Cl,pH}$) with slow kinetics of voltage-dependent activation. $I_{Cl,pH}$ was potently inhibited by an anion channel blocker 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (DIDS, 73.5% inhibition at 1${\mu}$M). $I_{Cl,pH}$ became more sensitive to $pH_e$ by raising temperature from $24^{circ}C$ to $37^{circ}C$. HaCaT cells also expressed $Ca^{2+}$-activated $Cl^-$ current ($I_{Cl,Ca}$), and the amplitude of $I_{Cl,Ca}$ was increased by relatively weak acidic $pH_e$ (7.0 and 6.8). Interestingly, the acidic $pH_e$ (5.0) also induced a sharp increase in the intracellular [$Ca^{2+}$] (${\triangle}[Ca^{2+}]_{acid}$) of HaCaT cells. The ${\triangle}[Ca^{2+}]_{acid}$ was independent of extracellular $Ca^{2+}$, and was abolished by the pretreatment with PLC inhibitor, U73122. In primary human keratinocytes, 5 out of 28 tested cells showed ${\triangle}[Ca^{2+}]_{acid}$. In summary, we found $I_{Cl,pH}$ and ${\triangle}[Ca^{2+}]_{acid}$ in human keratinocytes, and these ionic signals might have implication in pathophysiological responses and differentiation of epidermal keratinocytes.

• Journal of Ginseng Research
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• 제37권4호
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• pp.389-400
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• 2013

Korean Red Ginseng (KRG) has been reported to exert anticancer, anti-oxidant, and anti-inflammatory effects. However, there has been no report on the effect of KRG on skin pigmentation. In this study, we investigated the inhibitory effect of KRG on melanocyte proliferation. KRG extract (KRGE) at different concentrations had no effect on melanin synthesis in melan-A melanocytes. Saponin of KRG (SKRG) inhibited melanin content to 80% of the control at 100 ppm. Keratinocyte-derived factors induced by UV-irradiation were reported to stimulate melanogenesis, differentiation, proliferation, and dendrite formation. In this study, treatment of melan-A melanocytes with conditioned media from UV-irradiated SP-1 keratinocytes increased melanocyte proliferation. When UV-irradiated SP-1 keratinocytes were treated with KRGE or SKRG, the increase of melanocyte proliferation by the conditioned media was blocked. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was produced and released from UV-irradiated keratinocytes. This factor has been reported to be involved in regulating the proliferation and differentiation of epidermal melanocytes. In this study, GM-CSF was significantly increased in SP-1 keratinocytes by UVB irradiation ($30mJ/cm^2$), and the proliferation of melan-A melanocytes increased significantly by GM-CSF treatment. In addition, the proliferative effect of keratinocyte-conditioned media on melan-A melanocytes was blocked by anti-GM-CSF treatment. KRGE or SKRG treatment decreased the expression of GM-CSF in SP-1 keratinocytes induced by UVB irradiation. These results demonstrate that UV irradiation induced GM-CSF expression in keratinocytes and KRGE or SKRG inhibited its expression. Therefore, KRG could be a good candidate for regulating UV-induced melanocyte proliferation.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.231.1-231.1
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• 2003

Ultraviolet (UV) irradiation is well known to cause human skin aging and skin cancer through activation of matrix metalloproteinases (MMPs) which are responsible for the degradation of collagen, an extracellular matrix component. However, the molecular mechanisms of UV-induced MMP expression are yet to be defined. In this study, we investigated signaling molecules involved in UV-induced MMP expression in HaCaT human keratinocytes. (omitted)

• KSBB Journal
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• 제16권3호
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• pp.237-240
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• 2001

본 연구에서는 keratinocytes 세포를 이용하여 VEGF가 세포의 증식, MMP-2 및 plasmin 분비에 미치는 영향을 조사하였다. 그 결과 VEGF는 keratinocytes의 세포증식을 약 2.5배 상승시켜 내피세포 뿐반 아니라 상피세포에서도 강력한 mitogen임을 확인하였으며 submaximal effect를 보이는 농도는 10 ng/mL이었다. VEGF의 농도 증가에 따른 MMP-2의 분비에 미치는 효과 역시 10 ng/mL에서 최대 효과를 나타냈으며 VEGF 처리 후 1시간만에 확인 가능한 MMP-2 밴드가 나타났다. 한편, MMP-2의 분비 증가와 함께 plasmin의 분비 증가가 수반되는지를 확인한 결과 VEGF를 첨가했을 때 약 3배 정도 plasmin의 분비량이 증가함을 알 수 었었다. 이러한 결과는 VEGF의 성장촉진 효과와 관련자어 볼 때 MMP-2와 plasmin이 keratinocytes 세포의 성장과 이동에 부분적으로 관여할 것임을 시사하고 있다.

• International Journal of Oral Biology
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• 제32권3호
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• pp.93-101
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• 2007

Cell behavior of the transformed cells is known to affect by interaction with extracellular matrix (ECM) proteins and integrin. To investigate the alterations of both integrin expression and cell-matrix interaction during neoplastic conversion of human oral kerationcytes, we studied expression levels of integrin subunits by flow cytometry and cellular responses to the ECM proteins in normal human oral keratinocytes (NHOKs), HPV-immortalized HOK-16B line, and three oral cancer cell lines established from HOK-16B line, CTHOK-16B-BaP, CTHOK-16B-DMBA, and CTHOK-16B-Dexa lines. The expression levels of ${\alpha}\;and\;{\beta}$ integrin subunits were shown decreased tendency in human oral keratinocytes undergoing immortalization and tumorigenic transformation except CTHOK-16B-DMBA line tested. Although ${\alpha}v{\beta}6$ integrin is known to be highly expressed in squamous cell carcinomas, and the altered integrin expression is suspected to be associated with cellular carcinogenesis, ${\alpha}v$ integrin subunit and ${\alpha}v{\beta}6$ integrin did not express in oral cancer cell lines tested. Cell behavior to the ECM proteins in HOK-16B line was generally similar to that of exponentially proliferating NHOKs. The adhesion activity profiles of type I collagen were very similar to that of its laminin counterparts, but fibronectin showed minimal adhesion activity under our conditions compared to the BSA control. The ability of the CTHOK-16B-BaP line to spread upon type I collagen and laminin markedly decreased, but migration was notably increased on type I collagen. In contrast, CTHOK-16B-DMBA and CTHOK-16B-Dexa lines spread less but migrated more upon type I collagen than immortalized HOK-16B line. These data indicate that downregulation of integrin subunits causes the changes of cellular responses to the ECM proteins during neoplastic conversion of human oral keratinocytes, and that cellular responses to the ECM proteins in oral cancer cell lines established by exposing different carcinogens are variable according to chemical carcinogens treatment.

• Biomolecules & Therapeutics
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• 제21권5호
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• pp.349-357
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• 2013

6'-O-galloylpaeoniflorin (GPF) is a galloylated derivate of paeoniflorin and a key chemical constituent of the peony root, a perennial flowering plant that is widely used as an herbal medicine in East Asia. This study is the first investigation of the cytoprotective effects of GPF against hydrogen peroxide ($H_2O_2$)-induced cell injury and death in human HaCaT keratinocytes. GPF demonstrated a significant scavenging capacity against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, $H_2O_2$-generated intracellular reactive oxygen species (ROS), the superoxide anion radical ($O_2^-$), and the hydroxyl radical (${\cdot}$OH). GPF also safeguarded HaCaT keratinocytes against $H_2O_2$-provoked apoptotic cell death and attenuated oxidative macromolecular damage to DNA, lipids, and proteins. The compound exerted its cytoprotective actions in keratinocytes at least in part by decreasing the number of DNA strand breaks, the levels of 8-isoprostane (a stable end-product of lipid peroxidation), and the formation of carbonylated protein species. Taken together, these results indicate that GPF may be developed as a cytoprotector against ROS-mediated oxidative stress.

• Applied Microscopy
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• 제37권4호
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• pp.209-217
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• 2007

상처회복은 염증, 재상피화 그리고 기질의 재형성등이 관여하는 복잡한 과정이다. 이중 재상피화에 관여하는 각질화세포의 이동경로를 분석하기 위하여 무당개구리 피부 상처유도 후 투과전자현미경과 cytokeratin에 대한 조직면역화학법을 이용하였다. 정상조직의 cytokeratin발현은 기저층의 세포들과 선상피에서 확인되었다. 상처 유도후 3시간 조직에서, 기저세포층에서 강한 반응이 관찰되었고, 1일과 2일 사이에서는 재생되는 각질화세포에서 강한 면역반응이 확인되었다. 상처반응 중기인 7일부터 10일 사이에서도 재생된 세포의 기저층세포에서 강한 반응이 일어났다. 19일경과의 조직에서는 기저층과 유극층의 세포들에서 cytokeratin의 발현이 증가하였다. 따라서, 재상피화에 관여하는 각질화세포는 기저층의 세포로부터 시작하여 상처부위로 이동하여 과립층과 유극층으로 분화됨으로서 재상피가 진행되었다.

• Biomolecules & Therapeutics
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• 제18권1호
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• pp.56-64
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• 2010

Pentoxifylline (PTX) has been used for the local reduction of fat tissue in the clinical setting. However, its safety and efficacy have not been proven. The aim of this study was to evaluate the effects of PTX on cell lines established from fat tissue. Newly cultured human preadipocytes and adipocytes from subcutaneous abdominal fat in addition to purchased human lung fibroblasts and keratinocytes were treated with PTX at different concentrations. Cell viability was determined using the Cell counting kit (CCK)-8 assay and lipolysis was evaluated using an Elisa kit. DNA fragmentation, Western blot analysis, Hoechst and Propidium Iodide (PI) staining and fluorescence activated cell scanning analysis were performed to confirm apoptosis. The viability of adipocytes, preadipocytes, keratinocytes and fibroblasts was markedly decreased at concentrations of PTX above 20 mM. Apoptosis was induced at concentrations of PTX over 40 mM in all cell lines. Lipolysis was increased by 60% at concentrations of PTX of 20 mM compared to the control. In conclusion, the results of this study showed that 20 mM of PTX induced lipolysis. At concentrations over 20 mM, PTX reduced the viability of all cells studied including: adipocytes, preadipocytes, fibroblasts and keratinocytes, in a non-specific manner.