Journal of Dermatological Science

Editorial Board

2012-02-01

The Editor's Choice

2012-02-01

The role of TRPV1 channel in aged human skin

Young Mee Lee, So Min Kang, Jin Ho Chung — 2011-12-09

Abstract: Transient receptor potential vanilloid 1 (TRPV1) is a member of the nonselective cationic channel family. Activation of TRPV1 induces an influx of divalent and monovalent cations (i.e., Ca2+, Na+, and Mg2+) which are activated by capsaicin, heat, and acid. TRPV1 is known to be expressed in the epidermis, but little is known about the physiological significance and functional role of TRPV1 in skin.Recent studies suggested that heat- and ultraviolet (UV)-induced matrix metalloproteinases-1 (MMP-1) expression may be partly mediated by TRPV1 activation in human keratinocytes. Also, heat and UV increased expression of TRPV1 proteins in human skin in vivo. TRPV1 protein was expressed more in the sun-protected (upper-inner arm) skin of the elderly than in young subjects. In addition, the photoaged (forearm) skin of the elderly showed increased TRPV1 expression compared to sun-protected skin of the same individuals. The increased TRPV1 expression in the old skin implies that TRPV1 may be related to senile skin symptoms, such as senile pruritus and neurogenic inflammation. This review provides a summary of current researches on the role of TRPV1 channel in human skin, especially in aged skin.

Hypoxia and hypoxia mimetics inhibit TNF-dependent VCAM1 induction in the 5A32 endothelial cell line via a hypoxia inducible factor dependent mechanism

Todd V. Cartee, Kellie J. White, Marvin Newton-West, Robert A. Swerlick — 2011-11-17

Abstract: Background: We previously reported that iron chelators inhibit TNFα-mediated induction of VCAM-1 in human dermal microvascular endothelial cells. We hypothesized that iron chelators mediate inhibition of VCAM-1 via inhibition of iron-dependent enzymes such as those involved with oxygen sensing and that similar inhibition may be observed with agents which simulate hypoxia.Objective: We proposed to examine whether non-metal binding hypoxia mimetics inhibit TNFα-mediated VCAM-1 induction and define the mechanisms by which they mediate their effects on VCAM-1 expression.Methods: These studies were undertaken in vitro using immortalized dermal endothelial cells, Western blot analysis, ELISA, immunofluorescence microscopy, quantitative real-time PCR, and chromatin immunoprecipitation.Results: Hypoxia and the non-iron binding hypoxia mimetic dimethyl oxallyl glycine (DMOG) inhibited TNFα-mediated induction of VCAM-1. DMOG inhibition of VCAM-1 was dose-dependent, targeted VCAM-1 gene transcription independent of NF-κB nuclear translocation, and blocked TNFα-mediated chromatin modifications of relevant elements of the VCAM-1 promoter. Combined gene silencing of both HIF-1α and HIF-2α using siRNA led to a partial rescue of VCAM expression in hypoxia mimetic-treated cells.Conclusion: Iron chelators, non-metal binding hypoxia mimetics, and hypoxia all inhibit TNFα-mediated VCAM-1 expression. Inhibition is mediated independent of nuclear translocation of NF-κB, appears to target TNFα-mediated chromatin modifications, and is at least partially dependent upon HIF expression. The absence of complete VCAM-1 expression rescue with HIF silencing implies an important regulatory role for an Fe(II)/α-ketoglutarate dioxygenase distinct from the prolyl and asparagyl hydroxylases that control HIF function. Identification of this dioxygenase may provide a valuable target for modulating inflammation in human tissues.

Visualizing radiofrequency–skin interaction using multiphoton microscopy in vivo

2012-01-03

Abstract: Background: Redundant skin laxity is a major feature of aging. Recently, radiofrequency has been introduced for nonablative tissue tightening by volumetric heating of the deep dermis. Despite the wide range of application based on this therapy, the effect of this technique on tissue and the subsequent tissue remodeling have not been investigated in detail.Objective: Our objective is to evaluate the potential of non-linear optics, including multiphoton autofluorescence and second harmonic generation (SHG) microscopy, as a non-invasive imaging modality for the real-time study of radiofrequency–tissue interaction.Methods: Electro-optical synergy device (ELOS) was used as the radiofrequency source in this study. The back skin of nude mouse was irradiated with radiofrequency at different passes. We evaluated the effect on skin immediately and 1 month after treatment with multiphoton microscopy.Results: Corresponding histology was performed for comparison. We found that SHG is negatively correlated to radiofrequency passes, which means that collagen structural disruption happens immediately after thermal damage. After 1 month of collagen remodeling, SHG signals increased above baseline, indicating that collagen regeneration has occurred. Our findings may explain mechanism of nonablative skin tightening and were supported by histological examinations.Conclusions: Our work showed that monitoring the dermal heating status of RF and following up the detailed process of tissue reaction can be imaged and quantified with multiphoton microscopy non-invasively in vivo.

Mapping of B cell epitopes on desmoglein 3 in pemphigus vulgaris patients by the use of overlapping peptides

2012-01-19

Abstract: Background: Pemphigus vulgaris (PV) is a severe autoimmune blistering disease associated with autoantibodies to desmoglein 3 (Dsg 3), a transmembrane glycoprotein of the cadherin family. Previous studies mainly focused on the mapping of conformational epitopes of Dsg 3 using recombinant fragments of Dsg 3 and competition ELISA.Objective: Here, we performed a mapping of linear B cell epitopes on Dsg 3 in PV patients by the use of overlapping synthetic peptides.Methods: A set of 254 overlapping synthetic peptides of 14 amino acids length covering the entire Dsg 3 extracellular domain was generated. Sera of patients with active PV (n=10) and healthy volunteers (n=10) were tested for IgG reactivity with the 254 peptides by ELISA. Testing each peptide separately, 7 major antigenic sites were identified. In order to validate these reactivities, 7 corresponding peptides of 13–33 amino acids in length were generated and employed by ELISA. Additional sera of active PV patients (n=17) and healthy volunteers (n=20) were tested and the most reactive peptide was used to specifically purify anti-Dsg 3 antibodies from PV sera (n=3).Results: The major autoantibody reactivity in PV sera was mapped to amino acids 333–356 within the EC3 domain. Purifying patients IgG using the identified peptide, however, failed to induce acantholysis in keratinocyte dissociation assay.Conclusion: We conclude that linear epitopes do not play a major pathogenic role in human PV.

Lipid ingredients in moisturizers can modulate skin responses to UV in barrier-disrupted human skin in vivo

2011-12-30

Abstract: Background: Chemicals with a molecular weight <500 and adequate lipid solubility can penetrate the intact human skin. As many lipid ingredients in moisturizers have molecular weights <500, the lipid ingredients may penetrate into the skin and affect skin responses to UV; however, little is known about this phenomenon.Objective: To evaluate the effects of major lipid ingredients in moisturizers on skin responses to UV in tape-stripped human skin in vivo.Methods: We evaluated the effects of three major lipid ingredients in moisturizers (cholesterol, linoleic acid, and a synthetic ceramide, N-oleoyl-phytosphingosine) on skin responses to UV in the tape-stripped skin of healthy volunteers. After 2 days of lipid-application, the areas were irradiated with UV, and skin samples were obtained 24h after irradiation. Histologic features and the expression of the markers of collagen metabolism and inflammatory mediators were evaluated.Results: Compared to vehicle, topical cholesterol significantly decreased the degree of dermal inflammatory infiltrates and exocytosis, and also decreased the expression of MMP-1, IL-6, and IL-1ß mRNA. In contrast, topical linoleic acid increased the induction of apoptotic cells, and the expression of MMP-1 and IL-6 mRNA. N-oleoyl-phytosphingosine increased the expression of MMP-1 and IL-6 mRNA, while decreasing the expression of COX-2 mRNA.Conclusions: Topical cholesterol can protect the barrier-disrupted skin against UV-induced damage, while linoleic acid or N-oleoyl-phytosphingosine alone has the potential to aggravate the damage.

Expression of cytosolic NADP+-dependent isocitrate dehydrogenase in melanocytes and its role as an antioxidant

Ji Young Kim, Jae Yong Shin, Miri Kim, Seung-Kyung Hann, Sang Ho Oh — 2012-01-24

Abstract: Background: Cytosolic NADP+-dependent ICDH (IDPc) has an antioxidant effect as a supplier of NADPH to the cytosol, which is needed for the production of glutathione.Objective: To evaluate the expression of IDPc in melanocytes and to elucidate its role as an antioxidant.Methods: The knock-down of IDPc expression in immortalized mouse melanocyte cell lines (melan-a) was performed using the short interfering RNA (siRNA)-targeted gene silencing method. After confirming the silencing of IDPc expression with mRNA and protein levels, viability, apoptosis and necrosis, as well as ROS production in IDPc-silenced melanocytes were monitored under conditions of oxidative stress and non-stress. Also, the ratio of oxidized glutathione to total glutathione was examined, and whether the addition of glutathione recovered cell viability, decreased by oxidant stress, was checked.Results: The expression of IDPc in both primary human melanocytes and melan-a cells was confirmed by Western blot and RT-PCR. The silencing of IDPc expression by transfecting IDPc siRNA in melan-a cells was observed by Western blotting and real-time RT-PCR. IDPc knock-down cells showed significantly decreased cell viability and an increased number of cells under apoptosis and necrosis. IDPc siRNA-treated melanocytes demonstrated a higher intensity of DCFDA after the addition of H2O2 compared with scrambled siRNA-treated melanocytes, and a lower ratio of reduced glutathione to oxidized glutathione were observed in IDPc siRNA transfected melanocytes. In addition, the addition of glutathione recovered cell viability, which was previously decreased after incubation with H2O2.Conclusions: This study suggests that decreased IDPc expression renders melanocytes more vulnerable to oxidative stress, and IDPc plays an important antioxidant function in melanocytes.

EC-SOD induces apoptosis through COX-2 and galectin-7 in the epidermis

2012-01-17

Abstract: Background: Extracellular superoxide dismutase (EC-SOD) is an anti-oxidant enzyme found in the extracellular matrix of tissues, and plays an important role in the prevention of many diseases caused by oxidative stress. However, other functions of EC-SOD in epidermis are not well known.Objective: We investigated the functions of EC-SOD in epidermis using keratinocyte cell line and EC-SOD transgenic mice.Methods: Expression of galectin-7 in pEC-SOD transfected cells or skin of EC-SOD transgenic mice was detected by western blot analysis. The percentage of apoptotic cells was determined by propidium iodide staining and subsequent FACS analysis. COX-2 siRNA or scrambled siRNA was transfected into HaCaT cells and western blot analysis was performed to detect pro-apoptotic protein levels.Results: The epidermis of EC-SOD transgenic mice was thinner than wild type mice. In addition, we showed that the thin epidermis of EC-SOD transgenic mice results from the apoptosis of epidermal cells. To elucidate which molecules are involved in EC-SOD-induced apoptosis, we utilized two-dimensional electrophoresis; the results showed that the epidermis of EC-SOD transgenic mice produces more galectin-7, a pro-apoptotic factor, than the wild type. Furthermore, we showed that the transfection of EC-SOD-expressing plasmids induces the production of galectin-7, and pro-apoptotic proteins in keratinocytes. This suggests that EC-SOD induces apoptosis through increased galectin-7 expression. Finally, we demonstrated that EC-SOD-induced galectin-7 results from the production of COX-2.Conclusion: Our results imply that EC-SOD plays a role not only as a reactive oxygen species scavenger, but also as a pro-apoptotic factor via COX-2/galectin-7 pathways in the epidermis.

Podoplanin expression in wound and hyperproliferative psoriatic epidermis: Regulation by TGF-β and STAT-3 activating cytokines, IFN-γ, IL-6, and IL-22

Masaru Honma, Masako Minami-Hori, Hidetoshi Takahashi, Hajime Iizuka — 2011-12-22

Abstract: Background: Podoplanin (PDPN)/T1α/aggrus/PA2.26 antigen, a transmembranous glycoprotein, is a well-known lymphatic endothelial marker. Recent evidence indicates that PDPN is also expressed in keratinocytes especially of sebaceous glands.Objective: To verify expression-pattern and the regulatory mechanism of PDPN in human epidermal keratinocytes.Methods: PDPN-expression pattern was analyzed in normal and psoriatic epidermis by immunostaining. The regulatory mechanism of PDPN-expression of keratinocytes by cytokines was analyzed using specific inhibitors, siRNA, and adenoviral shRNA of signaling pathways.Results: In normal skin, PDPN was expressed on the basal cell layer of sebaceous glands and on the outer root sheath of hair follicles. While no expression was detected in the normal interfollicular epidermis, PDPN was detected in the basal cell layer of wound and hyperproliferative psoriatic epidermis, where the granular layer is lacking. TGF-β1 and IFN-γ independently upregulated PDPN-expression of keratinocytes via TGF-β receptor-Smad pathway and JAK-STAT pathway, respectively. IL-6 and IL-22 also stimulated PDPN-expression of keratinocytes accompanied by STAT-3 phosphorylation. siRNA of STAT-1, inhibitors of STAT-3 signaling, AG490, STAT-3 inhibitor VI, and si/shRNA of STAT-3 inhibited the PDPN-expression of keratinocytes induced by IFN-γ, IL-6 and IL-22 but not by TGF-β1.Conclusion: These results indicate that TGF-β1, IFN-γ, IL-6, and IL-22 induce PDPN-expression of keratinocytes, which might be significantly involved in the wound healing process as well as in the pathomechanism of hyperproliferative psoriatic epidermis.

Identification of the C-terminal tail domain of AHF/trichohyalin as the critical site for modulation of the keratin filamentous meshwork in the keratinocyte

Takahisa Takase, Yohei Hirai — 2012-01-19

Abstract: Background: AHF/trichohyalin is a large structural protein abundant in the inner root sheath (IRS) of anagenic hair follicles, which has been thought to mediate the keratin filamentous assembly. However, its functional mechanism is largely unknown.Objective: This study aimed at the identification of the key domain in AHF for keratin association and the establishment of a plausible mechanism for the modulation of the keratin meshwork.Methods: Several keratinocyte cell lines were introduced with the full length or several mutants of AHF, together with IRS-specific keratin krt31, and the profile of the AHF granules and the cellular behaviors were carefully analyzed.Results: Full length of AHF formed small round granules that clearly bound to and aligned on the exogenous keratin filaments in the keratinocytes, severely affected cellular growth, mobility and shape. Intriguingly, the removal of only 6 amino acids around the C-terminal tail of AHF resulted not only in the complete loss of its keratin adherent ability but also in a dramatic enlargement of the granules.Conclusion: We propose a model for cytoskeletal modulation in the IRS of anagenic hair follicles: AHF latches onto the keratin bundles by its C-terminus and rearranges the keratin meshwork by intrinsic cohesive activity for the granule formation.

Novel and recurrent COL7A1 mutations in Chilean patients with dystrophic epidermolysis bullosa

2012-01-03

Dystrophic epidermolysis bullosa (DEB) is a genodermatosis characterized by trauma-induced blister formation beneath the lamina densa and healing with scarring. In addition, patients often have nail dystrophy, pseudosyndactyly, corneal erosions, oesophageal strictures, anaemia and excessive caries .

Histone deacetylase activity is required for skin Langerhans cell maturation and phagocytosis

2012-01-05

Histone acetylation plays key roles in modulating chromatin structure and controlling the gene expression. It is widely accepted that densely packed DNA structure is related to histone acetylation status. Histone acetylation is a dynamic process controlled by the antagonistic actions of two classes of enzymes – the histone acetyltransferases (HATs) and the histone deacetylases (HDACs), which function to add acetyl groups or removed them from target histones, respectively . The balance between the actions of HATs and HDACs represents a key epigenetic regulatory mechanism in the gene expression regulations, which controls numerous developmental processes, biological pathways and disease states . Inhibition of HDACs has been shown to modulate gene transcription, induce growth arrest and apoptosis, or differentiation in the cancer cells. Several recent studies have indicated that HDAC inhibitors also have anti-inflammatory effects in the mouse models of different immune disorders, including atopic dermatitis, suggesting that HDAC inhibitors have immunosuppressive properties . However, the underlying mechanisms for HDAC inhibitors-mediated immune regulation remain poorly understood.

Detection of collagen VII autoantibodies to NC1 and NC2 domains of collagen VII by ELISA in suspected epidermolysis bullosa acquisita and bullous lupus erythematosus patients

E. Eugene Bain, Raminder K. Grover, Richard W. Plunkett, Ernst H. Beutner — 2012-01-06

We read with interest the original paper by Saleh et al. published recently in vol. 62:169–75. Here we share our experience with this type VII collagen ELISA (kindly supplied by Medical and Biological Laboratories CO., LTD, Nagoya, Japan) for the diagnosis of epidermolysis bullosa acquisita (EBA)/bullous lupus erythematosus (BLE).

CYP4F22 is highly expressed at the site and timing of onset of keratinization during skin development

2012-01-03

Autosomal recessive congenital ichthyoses (ARCI) include several subtypes: harlequin ichthyosis (HI), lamellar ichthyosis (LI) and congenital ichthyosiform erythroderma (CIE). To date, six causative genes have been identified in ARCI patients: ABCA12, TGM1, NIPAL4, CYP4F22, ALOXE3 and ALOX12B . The localization of transglutaminase 1, ABCA12 and 12R-lipoxygenase have been analyzed using samples from patients and model mice . However, as for NIPAL4, CYP4F22, and lipoxygenase-3, neither localization nor function has been fully clarified yet. Herein, we investigate the expression pattern and localization of NIPAL4, CYP4F22 and lipoxygenase-3 in developing human epidermis and primary cultured normal human keratinocytes.

JSID ABSTRACTS

2012-01-12