[Show abstract][Hide abstract] ABSTRACT: Protease-activated receptor 2 (PAR-2) participates in various biological activities, including the regulation of epidermal barrier homeostasis, inflammation, pain perception, and melanosome transfer in the skin.
To evaluate the basic physiological role of PAR-2 in skin.
We investigated PAR-2 expression in human epidermis, skin tumors, and cultured epidermal cells using western blot and immunohistochemical analysis. Additionally, we examined the effect of the PAR-2 agonist, SLIGRL-NH2, on cultured keratinocytes.
Strong PAR-2 immunoreactivity was observed in the granular layer of normal human skin and the acrosyringium of the eccrine sweat glands. In contrast, weak PAR-2 immunoreactivity was seen in the granular layer of callused skin and in the duct and gland cells of the eccrine sweat glands. Interestingly, PAR-2 immunoreactivity was very weak or absent in the tumor cells of squamous cell carcinoma (SCC) and syringoma. PAR-2 was detected in primary keratinocytes and SV-40T-transformed human epidermal keratinocytes (SV-HEKs), an immortalized keratinocyte cell line, but not in SCC12 cells. SV-HEKs that were fully differentiated following calcium treatment displayed higher PAR-2 expression than undifferentiated SV-HEKs. Treatment of cultured SV-HEKs with PAR-2 agonist increased loricrin and filaggrin expression, a terminal differentiation marker.
Our data suggest that PAR-2 is associated with terminal differentiation of epidermis and eccrine sweat glands.
Annals of Dermatology 08/2015; 27(4):364-70. DOI:10.5021/ad.2015.27.4.364 · 1.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epidermal keratinocytes provide protective role against external stimuli by barrier formation. In addition, kertinocytes exerts their role as the defense cells via activation of innate immunity. Disturbance of keratinocyte functions is related with skin disorders. Psoriasis is a common skin disease related with inflammatory reaction in epidermal cells. We attempted to find therapeutics for psoriasis, and found that Paeonia lactiflora Pallas extract (PE) has an inhibitory potential on poly (I:C)-induced inflammation of keratinocytes. PE significantly inhibited poly (I:C)-induced expression of crucial psoriatic cytokines, such as IL-6, IL-8, CCL20 and TNF-α, via down-regulation of NF-κB signaling pathway in human keratinocytes. In addition, PE significantly inhibited poly (I:C)-induced inflammasome activation, in terms of IL-1β and caspase-1 secretion. Finally, PE markedly inhibited poly (I:C)-increased NLRP3, an important component of inflammasome. These results indicate that PE has an inhibitory effect on poly (I:C)-induced inflammatory reaction of keratinocytes, suggesting that PE can be developed for the treatment of psoriasis.
International journal of clinical and experimental pathology 07/2015; 8(5):5236-41. · 1.89 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A multistage genome-wide association (GWA) analysis was conducted to investigate the genetic factors influencing ultraviolet (UV)-induced skin pigmentation in Korean females after UV exposure. Previously, a meta-analysis of two GWA studies evaluating ~500,000 single nucleotide polymorphisms (SNPs) in 99 Korean females identified eight SNPs that were highly associated with tanning ability. To confirm these associations, we genotyped the SNPs in an independent replication study (112 Korean females). We found that a novel SNP in the intron of the WW domain-containing oxidoreductase (WWOX) gene yielded significant replicated associations with skin tanning ability (P-value = 1.16 × 10(-4) ). To understand the functional consequences of this locus located in the non-coding region, we investigated the role of WWOX in human melanocytes using a recombinant adenovirus expressing a microRNA specific for WWOX. Inhibition of WWOX expression significantly increased the expression and activity of tyrosinase in human melanocytes. Taken together, our results suggest that genetic variants in the intronic region of WWOX could be determinants in the UV-induced tanning ability of Korean females. WWOX represents a new candidate gene to evaluate the molecular basis of the UV-induced tanning ability in individuals. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Lipedematous alopecia is a rare condition of unknown etiology characterized by a thick boggy scalp with varying degrees of hair loss. It is usually seen in adult African-American females, and a case in a 9-year-old was the youngest patient reported thus far. We report on the appearance of this condition in two children, a 6-year-old child and a 10-year-old child. Each presented with congenital patchy hair loss on the occipital area and the left temple. A boggy hairless scalp with soft swelling was detected in both patients. Histological examination showed increased thickness of the subcutaneous fat tissue with a decrease in hair follicles. These features were consistent with a diagnosis of lipedematous alopecia. We report two cases of congenital lipedematous alopecia, which has not been reported previously. Although congenital, these distinct clinical features should be kept in mind in the diagnosis of alopecic hair loss.
Annals of Dermatology 02/2015; 27(1):87-9. DOI:10.5021/ad.2015.27.1.87 · 1.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: S100A9 and S100A8 are called damage-associated molecular pattern (DAMP) molecules because of their pro-inflammatory properties. Few studies have evaluated S100A9 and S100A8 function as DAMP molecules in atopic dermatitis (AD). We investigated how house-dust mites affect S100A9 and S100A8 expression in Th2 cytokine- and Th17 cytokine-treated keratinocytes, and how secretion of these molecules affects keratinocyte-derived cytokines. Finally, we evaluated expression of these DAMP molecules in AD patients. S100A9 and S100A8 expression was strongly induced in IL-17A- and Dermatophagoides (D.) farinae-treated keratinocytes, respectively. Furthermore, co-treatment with D. farinae and IL-17A strongly increased expression of S100A9 and S100A8 compared with D. farinae-Th2 cytokine co-treatment. The IL-33 mRNA level increased in a dose-dependent manner in S100A9-treated keratinocytes, but TSLP expression did not change. S100A8/A9 levels were also higher in the lesional skin and serum of AD patients, and correlated with disease severity. Taken together, S100A9 and S100A8 may be involved in inducing DAMP-mediated inflammation in AD triggered by IL-17A and house-dust mites. This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Anetoderma is a rare cutaneous disorder characterized by a loss of normal elastic tissue that presents clinically as atrophic patches located mainly on the upper trunk. Recent studies suggest immunological mechanisms may play a role in this process. Furthermore, a secondary form of macular atrophy occurs in the course of infectious diseases (e.g. syphilis and tuberculosis) and autoimmune disease (e.g. systemic lupus erythematosus [SLE]). Here, we report the case of a 20-year-old woman previously diagnosed with SLE, who presented with numerous well-circumscribed atrophic macules on the face and upper trunk. Histopathological examination showed decreased elastic tissues in the reticular dermis and mononuclear cells adhering to elastic fibers, consistent with anetoderma. Thus, the eruptive anetoderma localized widely on the face and upper trunk may have been caused by an autoimmune response of SLE.
Annals of Dermatology 10/2014; 26(5):621-3. DOI:10.5021/ad.2014.26.5.621 · 1.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Genkwadaphnin is a daphnane diterpene ester molecule isolated from the flower buds of Daphne genkwa. In the present study, we investigated the apoptosis-inducing effect of genkwadaphnin in squamous cell carcinoma (SCC) cells. Apoptosis was triggered in SCC12 cells following genkwadaphnin treatment in a time- and concentration-dependent manner. Genkwadaphnin treatment increased phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Knockdown of JNK and p38 MAPK by recombinant adenovirus expressing microRNA (miR) resulted in significant inhibition of genkwadaphnin-induced apoptosis in SCC12 cells. Finally, pretreatment with the reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) markedly reduced SCC12 cell apoptosis, concomitant with significant inhibition of MAPK activation. These results indicate that genkwadaphnin has the potential to induce apoptosis in SCC cells, providing information on which to base further research with the aim of developing a cure for SCC.
Biochemical and Biophysical Research Communications 07/2014; 450(2). DOI:10.1016/j.bbrc.2014.06.118 · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Nuclear factor E2-related factor 2 (Nrf2) is one of the most important redox-sensitive transcription factors regulating expression of antioxidative genes and cytoprotective enzymes, which constitute the cellular response to oxidative stress and xenobiotic damage. In this study, we investigated the functional role of Nrf2 during normal epidermal keratinocyte (NHEK) differentiation. Immunohistochemical staining showed that Nrf2 is expressed from basal to granular layer of epidermis. When cultured NHEKs were treated with 1.2 mM calcium, Nrf2 expression was increased gradually in protein levels and Nrf2 translocated into the nucleus in a differentiation-dependent manner. When Nrf2 was overexpressed in NHEK by adenoviral transduction, the expression of the NHEK differentiation marker loricrin and keratin 10 was increased and overexpression of Nrf2 also increased the luciferase activity of loricrin in the absence of calcium. These results suggest that Nrf2 helps to promote the differentiation of epidermal keratinocytes.
Archives for Dermatological Research 05/2014; 306(7). DOI:10.1007/s00403-014-1470-x · 1.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: O-linked β-N-acetylglucosamine (O-GlcNAc) modification is one of the posttranslational modification, emerging as an important regulatory mechanism in various cellular events.
We attempted to investigate whether O-GlcNAcylation is involved in keratinocyte differentiation.
Immunohistochemistry and Western blot were performed to demonstrate O-GlcNAcylation in keratinocyte differentiation.
During calcium-induced keratinocyte differentiation, overall O-GlcNAcylation was decreased in a temporal manner. We focused our attention on transcription factor Sp-1, which is implicated in keratinocyte differentiation. Total Sp-1 level did not change during keratinocyte differentiation. However, O-GlcNAcylated Sp-1 was decreased in a keratinocyte differentiation-dependent manner. Interestingly, transcriptional activity of Sp-1, in terms of involucrin and loricrin promoter activities, was markedly increased by overexpression of O-GlcNAcase (OGA). In addition, membrane permeable non-O-GlcNAcylated Sp-1 did show transcriptional activity, while membrane permeable O-GlcNAcylated Sp-1 did not, suggesting O-GlcNAcylated Sp-1 is an inactive form in keratinocyte differentiation.
Our results reveal that O-GlcNAcylation is a dynamic regulatory mechanism for keratinocyte differentiation.
[Show abstract][Hide abstract] ABSTRACT: Nrf2 plays a role in protection of cells against oxidative stress and xenobiotic damage by regulating cytoprotective genes. In this study, we investigated the effect of Nrf2 on melanogenesis in normal human melanocytes (NHMCs). When NHMCs were transduced with a recombinant adenovirus expressing Nrf2, melanin synthesis was significantly decreased. Consistent with this result, overexpression of Nrf2 decreased the expression of tyrosinase and tyrosinase-related protein 1. The inhibitory effect of Nrf2 was reversed by overexpression of Keap1, an intracellular regulator of Nrf2. Interestingly, Nrf2 overexpression resulted in marked activation of PI3K/Akt signaling. Conversely, inhibition of PI3K activity by treatment with wortmannin reversed the depigmentary effects of Nrf2. Taken together, these results strongly suggest that Nrf2 negatively regulates melanogenesis by modulating the PI3K/Akt signaling pathway.
PLoS ONE 04/2014; 9(4):e96035. DOI:10.1371/journal.pone.0096035 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Imiquimod, a nucleoside analogue of the imidazoquinoline family, is being used to treat various cutaneous cancers including squamous cell carcinoma (SCC). Imiquimod activates anti-tumor immunity via Toll-like receptor 7 (TLR7) in macrophage and other immune cells. Imiquimod can also affect tumor cells directly, regardless of its impact on immune system. In this study, we demonstrated that imiquimod induced apoptosis of SCC cells (SCC12) and A20 was involved in this process. When A20 was overexpressed, imiquimod-induced apoptosis was markedly inhibited. Conversely, knockdown of A20 potentiated imiquimod-induced apoptosis. Interestingly, A20 counteracted activation of c-Jun N-terminal kinase (JNK), suggesting that A20-regulated JNK activity was possible mechanism underlying imiquimod-induced apoptosis of SCC12 cells. Finally, imiquimod-induced apoptosis of SCC12 cells was taken place in a TLR7-independent manner. Our data provide new insight into the mechanism underlying imiquimod effect in cutaneous cancer treatment.
PLoS ONE 04/2014; 9(4):e95337. DOI:10.1371/journal.pone.0095337 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Adenosine is a nucleoside, in which an adenine molecule is attached to a ribofuranose sugar moiety. It can be released into the microenvironment by metabolically active cells, and then fulfills a multitude of functions in regulation of cell proliferation, by activating four subtypes of G protein-coupled adenosine receptors.
In this study, we investigated the effect of adenosine on melanogenesis, using B16 melanoma cells.
The toxic effects of adenosine on B16 melanoma cells were assessed. To understand the mechanism of the effect of adenosine on melanogenesis in B16 cells, melanin content and tyrosinase activity were measured. Tyrosinase, tyrosinase-related protein-1, and dopachrome tautomerase were monitored by Western blotting. Finally, adenosine was applied to zebrafish embryos, and its in vivo effect on pigmentation investigated.
At a low concentration, adenosine increased melanin content and tyrosinase activity, while a high dose of adenosine resulted in inhibition of tyrosinase activity. Western blotting showed that adenosine increased tyrosinase protein levels slightly, while high-dose adenosine decreased the expression of tyrosinase. In zebrafish tests, adenosine slightly inhibited body pigmentation.
In this study, we investigated the effect of adenosine on melanogenesis, using the well-established B16 melanoma cell and zebrafish models. The results suggest that adenosine may inhibit pigmentation, through negative regulation of tyrosinase.
Annals of Dermatology 04/2014; 26(2):209-13. DOI:10.5021/ad.2014.26.2.209 · 1.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Traditional pharmacotherapy for onychomycosis has low to moderate efficacy and may be associated with adverse reactions and medication interactions limiting its use in many patients.
We evaluated the clinical efficacy and safety of a fractional carbon-dioxide laser with topical antifungal therapy in the treatment of onychomycosis.
In all, 24 patients were treated with fractional carbon-dioxide laser therapy and a topical antifungal cream. The laser treatment consisted of 3 sessions at 4-week intervals. Efficacy was assessed based on the response rate from standardized photographs, a microscopic examination of subungual debris, and subjective evaluations.
Among the patients, 92% showed a clinical response and 50% showed a complete response with a negative microscopic result. The factors that influenced a successful outcome were the type of onychomycosis and the thickness of the nail plate before treatment. The treatment regimen was well tolerated and there was no recurrence 3 months after the last treatment episode.
The study followed up only 24 patients and there were no relevant treatment controls.
Fractional carbon-dioxide laser therapy, combined with a topical antifungal agent, was effective in the treatment of onychomycosis. It should be considered an alternative therapeutic option in patients for whom systemic antifungal agents are contraindicated.
Journal of the American Academy of Dermatology 03/2014; 70(5). DOI:10.1016/j.jaad.2014.01.893 · 4.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: S100A8 and S100A9 are members of the S100 protein family and exist in neutrophils, monocytes, and macrophages. Recent studies have shown that S100A8 and S100A9 are associated with various neoplastic disorders; however, their roles in cutaneous squamous cell carcinoma (SCC) are not well defined. To investigate the expression and function of S100A8 and S100A9 in skin tumors, we examined the expression levels of S100A8 and S100A9 between premalignant and malignant skin tumors and investigated the functional roles of S100A8 and S100A9 in vitro and in vivo using recombinant adenovirus expressing S100A8 or S100A9. The immunopositive staining rates and intensities of S100A8 and S100A9 were higher in SCC than in premalignant skin tumors. When S100A8 and/or S100A9 were overexpressed in SCC12 cells using a recombinant adenovirus, cell growth and motility were increased. Similarly, when mouse skin was intradermally injected with SCC12 cells overexpressing S100A8 and/or S100A9, there were remarkable increases in tumor growth and volume. Both S100A8 and S100A9 are highly expressed in cutaneous SCC and play important roles in tumorigenesis. We suggest that S100A8 and S100A9 may be potential therapeutic targets for the prevention or treatment of SCC in skin.
Archives for Dermatological Research 02/2014; 306(5). DOI:10.1007/s00403-014-1453-y · 1.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this study, we investigated the role of glucocorticoid receptor (GR) in epidermal keratinocytes. In adult normal human skin, GR was highly expressed in the upper layers of the epidermis. Consistent with normal skin, GR expression was increased after calcium treatment of HaCaT keratinocytes cultured in vitro, suggesting that GR is involved in keratinocyte differentiation process. Overexpression of GR using an adenovirus showed that expression of involucrin, an early differentiation marker of keratinocytes, was markedly increased due to GR overexpression. However, treatment with dexamethasone, a GR agonist, did not increase involucrin expression. Overexpression of GR led to phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinases (ERK) in the absence of glucocorticoid, suggesting that the GR effect on involucrin expression is related to activation of intracellular signaling cascades. This idea was supported by the fact that GR-mediated involucrin induction was abolished after treatment with JNK and ERK inhibitors. In addition, GR mutants lacking the ligand-binding domain increased involucrin expression concomitantly with increase of ERK phosphorylation. Together, these results suggest that GR modulates involucrin expression of keratinocytes by regulating the intracellular signaling network in a ligand-independent manner.