Adiponectin Upregulates Filaggrin Expression via SIRT1-Mediated Signaling in Human Normal Keratinocytes

BACKGROUND: Filaggrin (FLG) is the major component of the epidermal granular layer and binds to and condenses the keratin cytoskeleton. FLG thus contributes to cell compaction and serves as a natural moisturizing factor by promoting unfolding and degradation into hygroscopic amino acids. Loss or downregulation of FLG has been shown to result in a weak stratum corneum, which causes water loss and increases the possibility of skin barrier-related seizure. Adiponectin (Acrp30) contributes to the functional recovery of somatic cells, including human normal epidermal keratinocytes (NHEKs). OBJECTIVE: To investigate the effect of Acrp30 in FLG expression and identifying its signal transduction mechanism. METHODS: Normal human keratinocytes were treated with Acrp30 and the levels of FLG were examined. Silent mating type information regulation 2 homolog (SIRT)-targeting siRNA and aryl hydrocarbon receptor nuclear translocator (ARNT)-targeting siRNA were used to identify the role of various signal transduction pathway components. RESULTS: Acrp30 upregulated SIRT1 and ARNT expression in NHEKs, resulting in increased FLG expression. Treatment with both SIRT1-targeting siRNA and ARNT-targeting siRNA blocked Acrp30 stimulation and silenced FLG expression. CONCLUSION: Adiponectin upregulates FLG expression through a SIRT1-mediated pathway. Our results suggest that Acrp30 is a promising agent for skin barrier permeability improvement.

Rapid Detection of Staphylococcus aureus and Methicillin-Resistant S. aureus in Atopic Dermatitis by Using the BD Max StaphSR Assay

Eczematous lesions of atopic dermatitis (AD) patients are known to be a source of Staphylococcus aureus (SA) transmission and might be a reservoir for community-associated methicillin-resistant SA (MRSA). The BD Max StaphSR (BD-SR) is a fully automated, multiplex real-time PCR assay for the direct detection and differentiation of SA and MRSA from nasal swab samples. We evaluated the detection rates of SA and MRSA from skin lesions of outpatients with AD using the BD-SR assay, and determined the usefulness of the BD-SR assay. A total of 244 skin swab samples (skin lesions of 213 outpatients with AD and normal skin of 31 healthy controls) were tested directly by using the BD-SR assay. Of the 213 samples from patients with AD, 69 (32.4%) were positive for SA, 6 (8.7%) of which were positive for MRSA. Only 1 (3.2%) of 31 samples from healthy controls was positive for SA. The BD-SR assay is effective for the rapid detection of SA and MRSA from skin swab samples, which can provide important information for managing patients with AD and preventing the spread of MRSA.

Distribution of Skin and Oral Microorganisms in Atopic Dermatitis / 대한피부과학회지

BACKGROUND: Atopic dermatitis (AD) is a chronically relapsing skin disease that is associated with a disturbance of the epidermal barrier function. Changes in the human skin microbiome have been suggested as a risk factor for AD. OBJECTIVE: The aim of this study was to explore the species distribution of microflora on the skin and in the oral cavity of healthy volunteers and patients with AD. METHODS: Samples for culture were obtained from both lesional skin and the oral cavity in 211 patients with AD and from both the normal skin and oral cavity of 24 healthy controls. Species identification was performed with the VITEK 2 system (bioMerieux Inc., Hazelwood, MO, USA). RESULTS: The isolation of Staphylococcus aureus from the skin was statistically more frequent among patients with AD than among healthy controls, while the isolation of Staphylococcus hominis and Micrococcus luteus were statistically more frequent among healthy controls than among patients with AD (p<0.05). In the oral cavity, S. aureus and Candida albicans were found more frequently in patients with AD, but the difference did was not statistically significant. CONCLUSION: This study provides an important insight into the species distribution of microorganisms on human skin and in the oral cavity. Further investigation is required to determine the role of specific microorganisms in the etiology and pathogenicity of AD.

Protective Effect of Survivin in Doxorubicin-Induced Cell Death in H9c2 Cardiac Myocytes

BACKGROUND AND OBJECTIVES: Apoptosis has been known to be an important mechanism of doxorubicin-induced cardiotoxicity. Survivin, which belongs to the inhibitor of apoptosis protein family, is associated with apoptosis and alteration of the cardiac myocyte molecular pathways. Therefore, we investigated the anti-apoptotic effect and cellular mechanisms of survivin using a protein delivery system in a doxorubicin-induced cardiac myocyte injury model. MATERIALS AND METHODS: We constructed a recombinant survivin which was fused to the protein transduction domain derived from HIV-TAT protein. In cultured H9c2 cardiac myocytes, TAT-survivin (1 microM) was added for 1 hour prior to doxorubicin (1 microM) treatment for 24 hours. Cell viability and apoptosis were evaluated by 2-(4,5-dimethyltriazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, caspase-3 activity, and terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling assay. We measured the expression levels of several apoptosis-related signal proteins. RESULTS: The survivin level was significantly reduced in a dose dependent manner up to 1 microM of doxorubicin in concentration. Purified recombinant TAT-survivin protein was efficiently delivered to H9c2 cardiac myocytes, and its transduction showed an anti-apoptotic effect, demonstrated by reduced caspase-3 activity and the apoptotic index, concomitantly with increased cell viability against doxorubicin injury. The phosphorylation of p38 mitogen-activated protein (MAP) kinase and the release of Smac from mitochondria were suppressed and the expression levels of Bcl-2 and cAMP response element-binding protein (CREB), the transcription factor of Bcl-2, were recovered following TAT-survivin transduction, indicating that survivin had an anti-apoptotic effect against doxorubicin injury. CONCLUSION: Our results suggest that survivin has a potentially cytoprotective effect against doxorubicin-induced cardiac myocyte apoptosis through mechanisms that involve a decrease in the phosphorylation of p38 MAP kinase, mitochondrial Smac release, and increased expression of Bcl-2 and CREB.

Cathepsin L derived from skeletal muscle cells transfected with bFGF promotes endothelial cell migration

Gene transfer of basic fibroblast growth factor (bFGF) has been shown to induce significant endothelial migration and angiogenesis in ischemic disease models. Here, we investigate what factors are secreted from skeletal muscle cells (SkMCs) transfected with bFGF gene and whether they participate in endothelial cell migration. We constructed replication-defective adenovirus vectors containing the human bFGF gene (Ad/bFGF) or a control LacZ gene (Ad/LacZ) and obtained conditioned media, bFGF-CM and LacZ-CM, from SkMCs infected by Ad/bFGF or Ad/LacZ, respectively. Cell migration significantly increased in HUVECs incubated with bFGF-CM compared to cells incubated with LacZ-CM. Interestingly, HUVEC migration in response to bFGF-CM was only partially blocked by the addition of bFGF-neutralizing antibody, suggesting that bFGF-CM contains other factors that stimulate endothelial cell migration. Several proteins, matrix metalloproteinase-1 (MMP-1), plasminogen activator inhibitor-1 (PAI-1), and cathepsin L, increased in bFGF-CM compared to LacZ-CM; based on 1-dimensional gel electrophoresis and mass spectrometry. Their increased mRNA and protein levels were confirmed by RT-PCR and immunoblot analysis. The recombinant human bFGF protein induced MMP-1, PAI-1, and cathepsin L expression in SkMCs. Endothelial cell migration was reduced in groups treated with bFGF-CM containing neutralizing antibodies against MMP-1 or PAI-1. In particular, HUVECs treated with bFGF-CM containing cell-impermeable cathepsin L inhibitor showed the most significant decrease in cell migration. Cathepsin L protein directly promotes endothelial cell migration through the JNK pathway. These results indicate that cathepsin L released from SkMCs transfected with the bFGF gene can promote endothelial cell migration.