P6417Down-regulation of type I collagen expression in silibinin-treated humanskin fibroblasts through blocking Smad2/3-dependent signaling pathway:Its potential therapeutic use in the chemoprevention of keloid

Kyu-Suk Lee, MD, PhD, Department of Dermatology, Keimyung University Schoolof Medicine, Daegu, South Korea; Jae-We Cho, MD, PhD, Department ofDermatology , School of Medicine, Keimyung University, Daegu, South Korea;Jun-Il Kwon, MD, Department of Dermatology, School of Medicine, KeimyungUniversity, Daegu, South Korea

Inhibition of the Smad2/3 pathway plays a key role on down-regulation of type Icollagen synthesis, eventually prevention of keloid formation in tissue. In this study,we investigated the effect of silibinin on the proliferation of human skin fibroblasts(HSFs), expressions of type I collagen, matrix metalloproteinase-1, and Smad2/3.Our data show that proliferation rates of fibroblasts were not markedly decreased ina dose- and time-dependent manner of silibinin. Even though silibinin did not exertcytotoxic effect in HSF, the expression of type I collagen was markedly decreased bydose- and time-dependent manner in silibinin-treated HSF. Consistent with, de-creased promoter activity of type I collagen was observed in HSF by silibinintreatment. MMP-1 and MMP-2 expressions were increased in silibinin-treated HSF.Moreover, silibinin-induced down-regulation of type I collagenwere associated withinhibition of Smad2/3 activation in TGF-b1etreated HSF. We further demonstratedthat silibinin attenuated the translocation of Smad2/3 into nucleus in TGF-b1etreated HSF. Taken together, our data indicated that silibinin has the potentialto protect fibrotic change of skin through inducing down-regulation of type Icollagen expression, which is partly mediated by blocking Smad2/3-dependentsignaling pathway in HSF.

AB36

cial support: None identified.

Commer

P6184Evidence from gene-expression profiling of the inhibition by niacinamideof both innate and adaptive immune response processes and pathwaysassociated with skin photoaging

Michael K. Robinson, PhD, The Procter and Gamble Company, Cincinnati, OH,United States; Jay P. Tiesman, PhD, The Procter and Gamble Company,Cincinnati, OH, United States; Kenton D. Juhlin, PhD, The Procter and GambleCompany, Cincinnati, OH, United States; Kevin J. Mills, PhD, The Procter andGamble Company, Cincinnati, OH, United States; Robert L. Binder, PhD, TheProcter and Gamble Company, Cincinnati, OH, United States; RosemarieOsborne, PhD, The Procter and Gamble Company, Cincinnati, OH, UnitedStates; Scott M. Hartman, The Procter and Gamble Company, Cincinnati, OH,United States

Background: Gene expression profiling of photoaged skin revealed strong up-regulation of biologic themes related to immune and inflammatory processes andtheir connection to processes of extracellular matrix, oxido-reductase activity, andprotease activity. This suggests that immune and inflammatory processes contributeto the skin photoaging phenotype. A separate gene expression profiling of skintreated with the known skin benefit agent, niacinamide, showed evidence of asubtle reversal of these or related themes. The purpose of this study was to applyadditional informatics analyses to these datasets to determine the potentialrelevance of innate and adaptive immune response processes and pathways inskin photoaging and the effect on these of niacinamide treatment.

Objective: To determine the potential role of innate and adaptive immune responsesin skin photoaging, and the effects of repeat topical application of niacinamide, viagene expression profiling analysis.

Method: Gene expression datasets were analyzed from 2 studies: (1) a photoagingphenotype study of UV exposed (outer forearm) and UV protected (buttock) skinfrom young (age 18-20) and older (age 60-67) female subjects, and (2) a study offorearm skin (females age 35-55) treated with 3.5% niacinamide-containing orvehicle lotion formulations twice a day for up to 15 days. In both studies, full-thickness skin biopsies were obtained and total RNA was extracted and labeled forAffymetrix GeneChip analysis. The analysis was based on hybridization toAffymetrix microarrays, containing up to 54,613 probe sets. The data weresubjected to rigorous statistical quality control and analysis, gene expressionprofiling, and gene set and subnetwork enrichment analysis. The latter wasspecifically focused on pathways and processes related to innate and adaptiveimmunity.

Results: Significant up-regulation of various immune pathways and processes werenoted in older photoaged versus younger UV protected skin. These included generalprocesses of innate and adaptive immunity and more specific processes such ascellular immunity, T cell function, NK cell function, leukocyte chemotaxis, toll-likereceptor processes, etc. Many of these processes were down-regulated in niacin-amide-treated versus vehicle-treated (or untreated) skin, providing additionalmechanistic insights into the known antiinflammatory effects of this skin benefitagent.

ded by The Procter and Gamble Company.

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J AM ACAD DERMATOL

P6248In vivo laser speckle measurement of skin roughness versus profilometricmeasurement of silicone replicas

Gurbir Dhadwal, MD, Photomedicine Institute, Department of Dermatology andSkin Science, University of British Columbia, Vancouver, Canada; Bernadette Ortiz-Policarpio, MD, Photomedicine Institute, Department of Dermatology and SkinScience, University of British Columbia, Vancouver, Canada; David McLean, MD,Photomedicine Institute, Department of Dermatology and Skin Science, Universityof British Columbia, Vancouver, Canada; Diana Diao, MD, Photomedicine Institute,Department of Dermatology and Skin Science, University of British Columbia,Vancouver, Canada; Harvey Lui, MD, Photomedicine Institute, Department ofDermatology, UBC; Cancer Control Research and Integrative Oncology, BC CancerAgency, Vancouver, Canada; Liuodmila Tchvialeva, PhD, Photomedicine Institute,Department of Dermatology and Skin Science, University of British Columbia,Vancouver, Canada; Tim Lee, PhD, Photomedicine Institute, Dermatology,University of British Columbia; Cancer Control Research and IntegrativeOncology, BC Cancer; Computing Science, Simon Fraser University, Vancouver,Canada

Background: Roughness is a property used in helping make the diagnosis of manyskin conditions, such as verrucae, actinic keratoses, and skin cancers, and is alsoused to assess the response to treatment in cosmetic dermatology. We developed anovel device and are conducting a study to measure in vivo the skin roughness of 25body sites and validate our technique against currently used silicone replica basedmethods, which are more time consuming. The device is based on measuring thecontrast of laser speckle patterns which are light and dark stochastic interferencepatterns generated when coherent light interacts with a rough surface. The contrastof images of laser speckle correlates with the roughness of surfaces.

Methods: Our study has recruited 40 volunteers (18 males; 22 females; mean age39.6 6 13.7), who have had 25 body sites measured by our portable device. Bodysites were categorized into minimally, intermittently and maximally sun exposed.ANOVA was used to assess for a significant relationship between skin roughness,body site and sun exposure. As well, silicone replicas were created of one body sitefrom each subject and measured with profilometry and compared with themeasurements from our device.

Results: Statistical analysis showed a significant relationship between body site andmeasured root-mean-square roughness (P\.001). The values of roughness rangedfrom 12.1 u 6 1.4 u for the palm, the smoothest site, to 32.4 u 6 1.1 u for the earlobe, the roughest site. On subgroup analysis, roughness of maximally sun exposedsites (28.0 u 6 0.4 u) was found to be significantly higher than the roughness ofintermittently (21.4 u 6 0.4 u) or minimally (21.2 u 6 0.5 u) sun exposed sites.There was a statistically significant correlation between the measurements fromour device and the measurements of silicone replicas using profilometry (r ¼ 0.51;P ¼ .02).

Conclusion: Here we report a data set of in vivo skin roughness of 25 body sites. Wefound that the roughness measurements from analysis of laser speckle wereconsistent with previously published results using other assessment methodologies,vary as expected with sun exposure, and correlate directly with measurements ofour subjects using profilometry of silicone replicas.

cial support: None identified.

Commer

P6887Persistence of corneodesmosomes and elevation of protease inhibitorsLEKTI and SCCA1 in dandruff

Bhumika Singh, PhD, Unilever R&D, Bebington, United Kingdom; Clive Harding,Unilever R&D, Bebington, United Kingdom

Corneodesmosomes (CDSMs) are the major cohesive component of the stratumcorneum (SC) and play a vital role in the water barrier function of this tissue. Fornormal desquamation to occur, CDSMs must be hydrolyzed by members of thekallikrein family of proteases. The activity of these proteases is in turn controlled bya specific inhibitor: lymphoepithelial Kazal-type related inhibitor (LEKTI). Thebalance between serine proteases and their cognate inhibitors is essential for SCintegrity. In cosmetic, dry skin conditions the hydrolysis of CDSMs is reduced,corneocytes cohesion is increased and desquamation is perturbed leading to thecharacteristic skin surface flaking. In contrast in dandruff, a condition alsoassociated with severe barrier impairment and perturbed desquamation, it hasbeen reported that this condition is associated with a premature loss of CDSMs. Tostudy the fate of CDSMs in more detail we investigated their distribution in thesuperficial layers of scalp SC recovered from both healthy individuals and dandruffsufferers. CDSMs were localized by immunohistochemical detection of desmoglein1 (DSG1). We also investigated the expression of LEKTI and the squamous cellcarcinoma antigen 1 (SCCA1), a protease inhibitor associated with perturbed barrierfunction. In healthy samples, DSG1 distributionwas limited to the cellular peripheryof adjacent corneocyteswithin the same plane of SC consistent with the distributionobserved on other healthy body sites. In samples of dandruff SC the CDSMs wereagain readily detectable. Immunofluorescence labelling showed that DSG1 waslocalized to peripheral/intercellular regions and over the entire surface area,reminiscent of the pattern of abnormal CDSM retention observed in dry skin.Western blot analysis of LEKTI and SCCA1 showed an elevated expression of bothproteins in samples of dandruff SC as compared to those from healthy SC. Ourfindings indicate that, the persistence of nonperipheral CDSMs is a characteristic ofthe perturbed desquamation seen in dandruff. The observations of increasedexpression of LEKTI and possibly SCCA1 are consistent with the view that thedandruff condition is characterized by an imbalance in protease/protease inhibitorinteraction in the SC.

ded by Unilever PLC.

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APRIL 2013