Skin Pharmacology and Physiology最新文献

Introduction: Non-invasive measurement of the stratum corneum hydration (SCH) with capacitance-based instrumentation is established in dermatological and cosmetic studies. We wanted to test the reliability of non-invasive self-measurements for SCH performed under real-life conditions by volunteers with a Bluetooth-based (wireless) probe Corneometer® (CM 825i) transmitting the data via a smartphone application to a central server. Probes and smartphones communicated using Bluetooth Low Energy. Data from the smartphone were securely transferred to a remote server in a different country with TLS encryption using HTTPS protocols. CM 825i values were correlated with the established CM 825 under laboratory conditions. The primary endpoint was the correlation of the two probes. Secondary endpoints were the coefficient of variation (CV) and delta values (before and after treatment).

Methods: Eighteen healthy volunteers (f: 8; m: 10) participated in the prospective observational study. The real-world home use of the wireless CM 825i was performed before and after treatments with base cream DAC for 7 days.

Results: Both instruments showed a significant and relevant correlation (p < 0.0001; Spearman coefficient of r = 0.8647). CM 825i and CM 825 differentiate significantly between normal and high SCH. Both devices showed comparable robustness in repeated measurements with a CV between 5.6% and 9.2%.

Conclusion: We could show a significant correlation between both devices and a comparable differentiation between low and high SCH and comparable CVs. The real-life use demonstrated adequate acquiring and transmitting of in vivo data to a smartphone and subsequently transmitting to the secure server with low numbers of missed transmissions (<0.2%) and missed measurements (<5%).

Introduction: The long-term use of topical corticosteroids (TCS) is associated with side effects such as skin atrophy and barrier deterioration. Moisturizers, such as mucopolysaccharide polysulfate (MPS), have been reported to prevent relapses in atopic dermatitis (AD) when used in combination with TCS. However, the mechanisms underlying the positive effects of MPS in combination with TCS in AD are poorly understood. In the present study, we investigated the effects of MPS in combination with clobetasol 17-propionate (CP) on tight junction (TJ) barrier function in human epidermal keratinocytes (HEKa) and 3D skin models.

Methods: The expression of claudin-1, which is crucial for TJ barrier function in keratinocytes, and transepithelial electrical resistance (TEER) was measured in CP-treated human keratinocytes incubated with and without MPS. A TJ permeability assay, using Sulfo-NHS-Biotin as a tracer, was also conducted in a 3D skin model.

Results: CP reduced claudin-1 expression and TEER in human keratinocytes, whereas MPS inhibited these CP-induced effects. Moreover, MPS inhibited the increase in CP-induced TJ permeability in a 3D skin model.

Conclusion: The present study demonstrated that MPS improved TJ barrier impairment induced by CP. The improvement of TJ barrier function may partially be responsible for the delayed relapse of AD induced by the combination of MPS and TCS.

Introduction: SHR0302 is a highly selective JAK1 inhibitor. This study aimed to investigate the safety, tolerability, and pharmacokinetics of single and multiple-dose topical skin application of SHR0302 base ointment in healthy adult subjects.

Methods: This phase I clinical trial (registration number: CTR20192188) consisted of two parts. Part 1 was a single-dose ascending study with four dose levels in 32 healthy Australian adults (8 subjects in each dose group). All Australian subjects were randomized 3:1 to a single-dose topical skin application of SHR0302 base ointment or placebo. The dose escalated from 1% SHR0302 base ointment on 3% of body surface area (BSA) to 2% SHR0302 base ointment on 20% of BSA. Part 2 combined single and multiple-dose ascension studies with two dose levels in 20 healthy Chinese adults (10 subjects in each dose group). All Chinese subjects were randomized 4:1 to a combination of single and multiple doses for consecutive 10 days of topical application of 1% SHR0302 base ointment on 20% BSA or 2% SHR0302 base ointment on 20% BSA. The safety and pharmacokinetics of the SHR0302 base ointment were evaluated.

Results: The incidence of treatment-emergent adverse events (TEAEs) in both parts was comparable between the SHR0302 base ointment group and the vehicle group (part 1: 33.3% vs. 37.5%; part 2: 56.3% vs. 75.0%). All TEAEs were transient, recovered, and equally well-tolerated in the two racial groups. The overall absorption of the SHR0302 base ointment was slow after topical application, with Tmax>10 h. After a single dose of the SHR0302 base ointment, drug exposure in healthy Australian and Chinese subjects increased nonlinearly with the increase in the administration area and drug content. Drug exposure increased in a less-than-dose-proportional manner within the dose range tested. Due to differences in the clinical practice of topical application, the Tmax of the drug in Australian subjects was earlier than in Chinese subjects, but the overall extent of absorption seemed comparable in Australian and Chinese subjects (with comparable AUC0-t).

Conclusion: The SHR0302 base ointment (either single or multiple doses) was well tolerated and safe, with no racial disparity.

Key message: The SHR0302 base ointment (either single or multiples doses) was well tolerated and safe.

Introduction: The outermost layer of the skin, the epidermis, is directly exposed to external stress (e.g., irradiation, allergens, and chemicals). Changes in epidermal conditions/environment in response to this stress could also influence conditions of the dermis, located directly beneath the epidermis. Yet, whether/how any epidermal environment changes in response to external stress affect dermal functions has not been completely clarified.

Methods: We employed ultraviolet irradiation B (UVB) (which hardly reaches the dermis) as a model of external stress. Human keratinocytes and human dermal fibroblasts were treated with UVB and conditioned medium of keratinocytes exposed to UVB (UVB-keratinocyte-M), respectively. We assessed (1) inflammatory cytokines and lipid mediators in keratinocytes; (2) matrix metalloprotease (MMP) levels and collagen degradation in fibroblasts; (3) ex vivo organ-cultured human skin was treated with UVB. MMP levels and collagen degradation were examined; (4) test whether the mixture of agent (agent cocktail) consisting of dihydroceramide, niacin amide, resveratrol, glucosyl hesperidin, and phytosterol ester that has been shown to improve skin barrier integrity can mitigate influence of UVB in skin; and (5) a pilot one-arm human clinical test to assess efficacy of formulation containing agent cocktail on stratum corneum hydration, skin elasticity, and wrinkle index.

Results: Inflammatory-cytokine and -lipid mediator production were increased in cultured keratinocytes treated with UVB, while matrix MMP-1, -3, and -9 production and collagen degradation were increased in fibroblasts incubated with UVB-keratinocyte-M. mRNA expression of COL1A1 (that codes type 1 collagen) levels was decreased in fibroblasts incubated with UVB-keratinocyte-M. The study using ex vivo organ-cultured human skin showed both MMP-1 and MMP-9 expression were increased in both epidermis and dermis and increased dermal collagen degradation following UVB irradiation. Increased MMP production and collagen degradation were attenuated by application of an agent cocktail. Finally, a pilot clinical study demonstrated that the formulation containing our agent cocktail likely has the ability to improve skin hydration, increase skin elasticity, and reduce the appearance of wrinkles.

Conclusion: Epidermal changes in epidermal environment and conditions in response to external stress affect dermal conditions, and these negative effects of external stress on various skin layers can be pharmacologically mitigated.

Introduction: Elastic skin fibers lose their mechanical properties during aging due to enzymatic degradation, lack of maturation, or posttranslational modifications. Dill extract has been observed to increase elastin protein expression and maturation in a 3D skin model, to improve mechanical properties of the skin, to increase elastin protein expression in vascular smooth muscle cells, to preserve aortic elastic lamella, and to prevent glycation.

Objective: The aim of the study was to highlight dill actions on elastin fibers during aging thanks to elastase digestion model and the underlying mechanism.

Methods: In this study, elastic fibers produced by dermal fibroblasts in 2D culture model were injured by elastase, and we observed the action of dill extract on elastic network by elastin immunofluorescence. Then action of dill extract was examined on mice skin by injuring elastin fibers by intradermal injection of elastase. Then elastin fibers were observed by second harmonic generation microscopy, and their functionality was evaluated by oscillatory shear stress tests. In order to understand mechanism by which dill acted on elastin fibers, enzymatic tests and real-time qPCR on cultured fibroblasts were performed.

Results: We evidence in vitro that dill extract is able to prevent elastin from elastase digestion. And we confirm in vivo that dill extract treatment prevents elastase digestion, allowing preservation of the cutaneous elastic network in mice and preservation of the cutaneous elastic properties. Although dill extract does not directly inhibit elastase activity, our results show that dill extract treatment increases mRNA expression of the endogenous inhibitor of elastase, elafin.

Conclusion: Dill extract can thus be used to counteract the negative effects of elastase on the cutaneous elastic fiber network through modulation of PI3 gene expression.

Background: The anatomic layers of the skin are well-defined, and a functional model of the skin barrier has recently been described. Barrier disruption plays a key role in several skin conditions, and moisturization is recommended as an initial treatment in conditions such as atopic dermatitis. This review aimed to analyze the skin barrier in the context of the function model, with a focus on the mechanisms by which moisturizers support each of the functional layers of the skin barrier to promote homeostasis and repair.

Summary: The skin barrier is comprised of four interdependent layers - physical, chemical, microbiologic, and immunologic - which maintain barrier structure and function. Moisturizers target disruption affecting each of these four layers through several mechanisms and were shown to improve transepidermal water loss in several studies. Occlusives, humectants, and emollients occlude the surface of the stratum corneum (SC), draw water from the dermis into the epidermis, and assimilate into the SC, respectively, in order to strengthen the physical skin barrier. Acidic moisturizers bolster the chemical skin barrier by supporting optimal enzymatic function, increasing ceramide production, and facilitating ideal conditions for commensal microorganisms. Regular moisturization may strengthen the immunologic skin barrier by reducing permeability and subsequent allergen penetration and sensitization.

Key messages: The physical, chemical, microbiologic, and immunologic layers of the skin barrier are each uniquely impacted in states of skin barrier disruption. Moisturizers target each of the layers of the skin barrier to maintain homeostasis and facilitate repair.

Introduction: Eczema is a debilitating skin disorder clinically characterised by the development of itchy, dry, rough, and scaling skin caused by a series of rudimentary clinical phenotypes.

Methods: This double-blind, randomised, comparator-controlled trial evaluated the effectiveness of topical application of a novel palmitoylethanolamide formulation (Levagen+) compared with a standard moisturiser (comparator) to reduce eczema severity and improve patient outcomes. Seventy-two participants aged over 18 years old with atopic eczema (symptoms including redness, dry skin, scaling, and/or itchiness) on their hands or arm were recruited. Participants were randomly allocated to one of two treatment groups (Levagen + or comparator). Treatment was applied to the affected area twice daily for 4 weeks. Outcome measures included Self-Assessed Eczema Area Severity Index (SA-EASI) scoring and Patient-Oriented Eczema Measure (POEM) from baseline to week 4.

Results: Levagen+ was effective at alleviating symptom severity of eczema over 4 weeks. Levagen+ significantly reduced redness, dryness, and total POEM score compared to a comparator cream.

Conclusion: Levagen+ can significantly reduce eczema symptom severity compared to a comparator product, supporting its use as a potential treatment for eczema.

Trial registration: clinicaltrials.gov Identifier: NCT05003453.