β-Catenin Regulates the Expression of cAMP Response Element-Binding Protein 1 in Squamous Cell Carcinoma Cells

No abstract available.

Erratum: Possible Role of Single Stranded DNA Binding Protein 3 on Skin Hydration by Regulating Epidermal Differentiation

The authors would like to change the corresponding author of the article.

Possible Role of Single Stranded DNA Binding Protein 3 on Skin Hydration by Regulating Epidermal Differentiation

BACKGROUND: Skin hydration is a common problem both in elderly and young people as dry skin may cause irritation, dermatological disorders, and wrinkles. While both genetic and environmental factors seem to influence skin hydration, thorough genetic studies on skin hydration have not yet been conducted. OBJECTIVE: We used a genome-wide association study (GWAS) to explore the genetic elements underlying skin hydration by regulating epidermal differentiation and skin barrier function. METHODS: A GWAS was conducted to investigate the genetic factors influencing skin hydration in 100 Korean females along with molecular studies of genes in human epidermal keratinocytes for functional study in vitro. RESULTS: Among several single nucleotide polymorphisms identified in GWAS, we focused on Single Stranded DNA Binding Protein 3 (SSBP3) which is associated with DNA replication and DNA damage repair. To better understand the role of SSBP3 in skin cells, we introduced a calcium-induced differentiation keratinocyte culture system model and found that SSBP3 was upregulated in keratinocytes in a differentiation dependent manner. When SSBP3 was overexpressed using a recombinant adenovirus, the expression of differentiation-related genes such as loricrin and involucrin was markedly increased. CONCLUSION: Taken together, our results suggest that genetic variants in the intronic region of SSBP3 could be determinants in skin hydration of Korean females. SSBP3 represents a new candidate gene to evaluate the molecular basis of the hydration ability in individuals.

The Effect of FK 506 on the Reepithelialization of Superficial Skin Wound

No abstract available.

Induction of Interleukin-22 (IL-22) production in CD4+ T Cells by IL-17A Secreted from CpG-Stimulated Keratinocytes

BACKGROUND: Interleukin-17A (IL-17A) is mainly secreted from Th17 cells that are activated by various stimuli including CpG oligodeoxynucleotide, a Toll-like receptor 9 (TLR9) ligand. Recently, it has been demonstrated that keratinocytes play an important role in the pathogenesis of psoriasis. OBJECTIVE: To investigate the potential role of keratinocytes, we examined whether TLR9 ligand CpG induces IL-17A expression in keratinocytes. METHODS: We used HaCaT keratinocytes as a model system, and determined CpG-induced IL-17A using enzyme-linked immunosorbent assay and Western blot. RESULTS: When HaCaT keratinocytes were treated with CpG, the expression of several cytokines including IL-17A, tumor necrosis factor-α and CCL20 was markedly increased. Treatment with nuclear factor (NF)-κB inhibitor significantly blocked the CpG-induced IL-17A production, indicating that CpG induced IL-17A expression through the NF-κB signaling pathway. In addition, IL-17A secreted from keratinocytes stimulated the CD4⁺ T cells, resulting in strong induction of IL-22 production. CONCLUSION: Since IL-22 is an important mediator for psoriatic inflammation, our data suggest that keratinocytes can participate in the pathogenesis of psoriasis via the TLR9-dependent IL-17A production.

Effect of MITF-M and MITF-A Overexpression on the Dendrtic Formation in Melanocytes / 체질인류학회지

The microphthalmia-associated transcription factor (MITF), has been described as the master regulator of the basic helix-loop-helix leucine zipper family, involves melanogenesis in melanocytes. MITF consists of at least six isoforms, called MITF-M, MITF-A, MITF-B, MITF-C, MITF-H, and MITF-J. Previously, we found that not only MITF-M is expressed in the human hair follicle, but also MITF-A, MITF-C, MITF-H, and MITF-J isoforms are expressed in the skin. The aim of this study was to conform the MITF isoforms expressed in human skin, and investigate novel role of MITF isoforms in the melanocytes. Expression of MITF-M and MITF-A was found in primary melanoctyes and the melanoma cell lines. Interestingly, when MITF-M and MITF-A were overexpressed in the SK-MEL-24 melanoma cells by adenoviral transfection, length of the dendrites, serves as the principal conduit for melanosomes transfer, was significantly increased in the MITF-M overexpressed cells compared with the control group, and number of the dendtrites was significantly increased in the MITF-A overexpressed cells. A signal molecule involve in actin polymerization during dendrite formation, Rac1, was increased in the SK-MEL-24 melanoma cells treated with adenoviral MITF-M and MITF-A vectors. These results suggest that MITF-M and MITF-A induce dendrite formation via Rac1 signaling in the melanocytes.

Potential Role of S100A8 in Cutaneous Squamous Cell Carcinoma Differentiation

BACKGROUND: S100A8 is differentially expressed in various cell types and is associated with a number of malignant disorders. S100A8 may affect tumor biology. However, its role in cutaneous squamous cell carcinoma (SCC) is not well established. OBJECTIVE: This study aims to investigate the relationship between S100A8 and cutaneous SCC development. METHODS: We performed immunohistochemical staining to detect S100A8 expression in facial skin specimens of premalignant actinic keratosis (AK), malignant SCC, and normal tissues. In addition, we utilized postconfluence and high calcium-induced differentiation in a culture system model. Furthermore, we constructed a recombinant adenovirus expressing GFP-tagged S100A8 to investigate the role of S100A8 in SCC cell differentiation. RESULTS: S100A8 was significantly overexpressed in human cutaneous SCC compared to that in normal and AK tissues. S100A8 was gradually upregulated in SCC cells in a post-confluence-induced differentiation model. Overexpression of S100A8 in SCC cells induced by adenoviral transduction led to increased expression levels of differentiation markers, such as loricrin, involucrin, and filaggrin. S100A8 overexpression also increased loricrin and involucrin luciferase activity. CONCLUSION: S100A8 regulates cutaneous SCC differentiation and induces well-differentiated SCC formation in skin.

Immunohistochemical Study of O-GlcNAcylation in Human Skin Tumors / 체질인류학회지

O-linked beta-N-acetylglucosamine modification is an important post-translational modification, emerging as a novel regulatory mechanism in various cellular events. Recently, several studies have shown that O-GlcNAcylation plays an essential role in human breast, lung, and colon cancers. With regard to skin cancers, the role of O-GlcNAcylation has yet to be elucidated. To investigate whether O-GlcNAcylation is linked to human skin tumor development, immunohistochemical analysis was performed to investigate the presence of O-GlcNAcylation in various skin tumors. We evaluated the levels of O-GlcNAcylation, O-GlcNAc transferase, and O-GlcNAcase in 29 benign tumors, 12 premalignant tumors, and 26 malignant tumors in skin. Compared to the benign tumors, premalignant and malignant tumors had increased patterns of O-GlcNAcylation. In addition, the O-GlcNAc transferase and O-GlcNAcase levels were higher in premalignant and malignant tumors than in benign tumors. Interestingly, O-GlcNAcase levels were significantly increased in premalignant tumors compared to benign and malignant tumors. These results suggest that O-GlcNAcylation of proteins may play an important role in the development of human skin tumors.

Epigenetic Modulation of Gene Expression during Keratinocyte Differentiation

BACKGROUND: Epigenetic modulation of gene expression occurs by various methods, including DNA methylation and histone modification. DNA methylation of specific genes may affect the chromatin structure, preventing access by the transcriptional machinery. Although gene expression is dramatically changed during keratinocyte differentiation, there is no evidence of epigenetic modulation during the process of epidermal stratification. OBJECTIVE: We investigated whether epigenetic modulation is involved in keratinocyte differentiation-specific gene regulation. METHODS: We used trypsin to produce epidermal fragmentation (named T1-T4) and performed a morphological analysis using hematoxylin-eosin stain and cytokeratin expression based on reverse transcription polymerase chain reaction. We then constructed a DNA methylation microarray. RESULTS: Each epidermal fragment showed morphological features of the epithelial layer. T1 represented the basal layer, T2 was the spinous layer, T3 was the granular layer, and T4 was the cornified layer. The level of the K14 proliferation marker was increased in the T1 fraction, and the level of K10 differentiation marker was increased in the T2-T4 fractions. Using a methylation microarray with the T1 and T4 fractions, we obtained many hypermethylated and hypomethylated genes from differentiated keratinocytes. CONCLUSION: The importance of epigenetic modulation in target gene expression during keratinocyte differentiation is identified.

Changes in Transepidermal Water Loss and Skin Hydration according to Expression of Aquaporin-3 in Psoriasis

BACKGROUND: Aquaporins (AQPs) are a family of water transporting proteins present in many mammalian epithelial and endothelial cell types. Among the AQPs, AQP3 is known to be a water/glycerol transporter expressed in human skin. OBJECTIVE: The relationship between the expression level of AQP3 and transpidermal water loss (TEWL) in the lesional and peri-lesional skin of psoriasis-affected patients, and skin hydration in the lesional and peri-lesional skin of psoriasis patients, was investigated. METHODS: The expression of AQP3 in psoriasis-affected and healthy control skin was determined using immunohistochemical and immunofluroscence staining. TEWL and skin hydration were measured using a Tewameter(R) TM210 (Courage & Khazaka, Cologne, Germany) and a Corneometer(R) CM 820 (Courage & Khazaka), respectively. RESULTS: AQP3 was mainly expressed in the plasma membrane of stratum corneum and the stratum spinosum in normal epidermis. Unlike the normal epidermis, AQP3 showed decreased expression in the lesional and peri-lesional epidermis of psoriasis. TEWL was increased, and skin hydration was decreased, in the lesional and peri-lesional skin of psoriasis patients, compared with the healthy control sample. CONCLUSION: Although various factors contribute to reduced skin hydration in the lesional and peri-lesional skin of psoriasis, AQP3 appears to be a key factor in the skin dehydration of psoriasis-affected skin.

Sox9 Increases the Proliferation and Colony-forming Activity of Outer Root Sheath Cells Cultured In Vitro

BACKGROUND: beta-catenin plays a pivotal role in hair follicle development and hair growth cycle. OBJECTIVE: The aim of this study was to identify beta-catenin-regulated genes in cultured human hair outer root sheath (ORS) cells. METHODS: Primary cultured ORS cells were transduced with recombinant adenovirus expressing N-terminal truncated beta-catenin (constitutive active form), and beta-catenin-regulated genes were identified. RESULTS: Overexpression of the constitutively active form of beta-catenin led to induction of Sox9 expression at both mRNA and protein levels. To investigate the potential role of Sox9, we made the recombinant adenovirus expressing green fluorescent protein-tagged Sox9, and then transduced into cultured ORS cells. Interestingly, Sox9 induced the expression of keratin 15, increased the proliferation of ORS cells in vitro, and enhanced colony-forming activity. CONCLUSION: Our results suggest that Sox9 is a beta-catenin-regulated gene in ORS cells, and has potential importance in the regulation of hair follicle homeostasis.

Effects of Calcium on the Epidermis in a Skin Organ Culture / 대한피부과학회지

BACKGROUND: Calcium plays a role in the proliferation and differentiation of keratinocytes. In a normal situation, the calcium concentration forms a gradient across the epidermal layers. Calcium is sparse in the basal layer and spinous layer. Skin organ culture is a useful model for conducting research on various aspects of skin biology. Skin organ culture systems are used for defining factors that affect homeostasis when elucidating the modulatory effects of biologic response modifiers, drugs and physical agents on the skin and also when studying complex aspects of cutaneous biology in normal and diseased skin. OBJECTIVE: In this study, we investigated the effects of extracellular calcium on the epidermis in a skin organ culture. METHODS: We compared the skin organ culture patterns under various culture conditions (calcium 0.1, 0.7, 1.4 and 2.0 mM). RESULTS: H&E staining showed different phenotypes according to the calcium concentration and IHC also showed different phenotyes compared to that of keratin 10, involucrin, filaggrin, loricrin and PCNA. CONCLUSION: As a result, we concluded that the calcium gradient is also an important factor in skin organ culture to maintain the vivo-like environment and the appropriate calcium concentration is 1.4 mM.

Expression of N-terminal truncated desmoglein 3 (Delta NDg3) in epidermis and its role in keratinocyte differentiation

During a search for keratinocyte differentiation-related genes, we obtained a cDNA fragment from the 5'-untranslated region of a previously identified splicing variant of desmoglein 3 (Dg3). This transcript encodes a protein of 282 amino acids, which corresponds to the N-terminal truncated intracellular domain of Dg3 (Delta NDg3). Northern blot analysis detected a 4.6-kb transcript matching the predicted size of Delta NDg3 mRNA, and Western blot analysis with an antibody raised against the Dg3 C-terminus (H-145) detected a 31-kDa protein. Increased Delta NDg3 expression was observed in differentiating keratinocytes by RT-PCR and Western blot analysis, suggesting that Delta NDg3 is indeed a differentiation-related gene product. In immunohistochemical studies of normal and pathologic tissues, H-145 antibody detected the protein in the cytoplasm of suprabasal layer cells, whereas an antibody directed against the N-terminal region of Dg3 (AF1720) reacted with a membrane protein in the basal layer. In addition, Delta NDg3 transcript and protein were upregulated in psoriatic epidermis, and protein expression appeared to increase in epidermal tumors including Bowen's disease and squamous cell carcinoma. Moreover, overexpression of Delta NDg3 led to increased migration and weakening of cell adhesion. These results suggest that Delta NDg3 have a role in keratinocyte differentiation, and that may be related with tumorigenesis of epithelial origin.