Proliferation Of Epidermal Keratinocytes Research Articles

Fluoxetine exerts anti-proliferative effect in human epidermal keratinocytes.

We have recently shown that fluoxetine (FX) suppressed polyinosinic-polycytidylic acid-induced inflammatory response and endothelin release in human epidermal keratinocytes, via the indirect inhibition of the phosphoinositide 3-kinase (PI3K)-pathway. Because PI3K-signaling is a positive regulator of the proliferation, in the current, highly focused follow-up study, we assessed the effects of FX (14 µM) on the proliferation and differentiation of human epidermal keratinocytes. We found that FX exerted anti-proliferative actions in 2D cultures (HaCaT and primary human epidermal keratinocytes [NHEKs]; 48- and 72-h; CyQUANT-assay) as well as in 3D reconstructed epidermal equivalents (48-h; Ki-67 immunohistochemistry). Importantly, FX did not influence epidermal thickness (hematoxylin-eosin staining), and it did not have a major impact on the differentiation-associated alteration of the gene expression pattern (24-h treatments; RNA-Seq). Moreover, neither keratin (K)-1, nor K10 expression was altered by FX in NHEKs (RT-qPCR) or in 3D epidermal equivalents (semi-quantitative immunohistomorphometry). FX did not influence differentiation-induced up-regulation of occludin (RT-qPCR; NHEKs), and did not alter differentiation-associated barrier forming capacity of epidermal keratinocytes (electrical impedance; Lucifer Yellow penetration assay). Our data indicate that, besides the previously reported combined anti-inflammatory and putative anti-pruritic effects, FX may also suppress proliferation of human epidermal keratinocytes without impairing their differentiation and barrier-forming capacity.

Bioactive Effect of Plasma-Rich in Growth Factors (PRGFs) on Cell-Based In Vitro Models of Skin Inflammation in Relation to Inflammatory Skin Disorders.

Plasma rich in growth factors (PRGFs) has proven potentially beneficial as a bioregenerator in patients with chronic skin disorders due to its anti-inflammatory effect. However, its therapeutic potential may be limited by soluble autoimmune components associated with inflammatory dermatoses in blood plasma. To evaluate the impact of skin health status on cell bioactivity, PRGF was prepared from healthy (H) donors as well as from individuals with atopic dermatitis (AD), psoriasis (PS), or lichen sclerosus (LS). Leukocyte exclusion and heat inactivation (Immunosafe treatment) were evaluated as potential methods to reduce the inflammatory components of the samples under study. The biological effect of PRGF-derived formulations was investigated using cell-based in vitro skin inflammation models, including human dermal fibroblasts (HDFs) and human epidermal keratinocytes (HEKs) exposed to a pro-inflammatory environment. The data confirmed that viability, proliferation, and migration rates were enhanced in inflamed cell cultures supplemented with PRGF formulations compared to those maintained in standard culture media. Nevertheless, significant differences have been identified. About the healthy control, inflamed epidermal keratinocytes supplemented with most PRGF-based formulations obtained from pathological donors (PS/LS) showed lower viability. Heat inactivation significantly promoted cell proliferation in epidermal keratinocytes supplemented with SP (PS/LS) and L-PRP supernatant (LSP) samples (AD), and also cell migration in inflamed HDF (AD/H/LS) and HEK (AD/LS) models supplemented with LSP. Leukocyte exclusion improved cell behavior in terms of migration with the only exception of LSP from individuals with AD added to inflamed HEK cultures. In conclusion, PRGF derived from pathological patients contains autoimmune components that could compromise its effectiveness as a therapy for treating individuals with chronic inflammatory disorders. However, heat inactivation (Immunosafe treatment) or leukocyte exclusion could minimize local adverse effects.

RNA Sequencing Reveals That the Genes Related to Cell Cycle and Glycolysis Play an Essential Role in IL-27-Induced Keratinocyte Hyperproliferation.

Psoriasis is characterized by accelerated proliferation of epidermal keratinocytes. IL-27 is relevant to psoriasis pathogenesis. We previously found that IL-27 stimulates the proliferation of keratinocytes. However, the mRNAs involved in the process have not been fully studied. This study aims to identify potential pathways and hub genes associated with proliferation in keratinocytes with IL-27 intervention by bioinformatics analysis. The mRNA expression profiles from HaCaT cells with or without IL-27 treated were analyzed by bioinformatics tools. The protein-protein interaction (PPI) network was constructed to screen gene clusters and hub genes associated with proliferation. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) were used to identify the function of the mRNAs. The GEO database and quantitative real-time PCR (qPCR) were used to verify the expression levels of hub genes in psoriatic skin lesions and IL-27-treated psoriasiform keratinocytes, respectively. We found 1257 differentially expressed genes and screened 2 crucial gene clusters. GO analysis revealed that Cluster 1 was mainly enriched in "Mitotic sister chromatid segregation" and "Spindle". Cluster 2 was mainly enriched in the "Pyruvate metabolic process" and "Oxidoreductase complex". KEGG analysis showed that Cluster 1 and Cluster 2 were mainly enriched in "Cell cycle" and "Glycolysis/Gluconeogenesis", respectively. We then identified 6hub genes enriched in the two pathways, including CCNB1, PTTG1, CDC20, PLK1, PKM, and LDHA. GSEA complemented the role of the mitochondrial "Oxidative phosphorylation" pathway. Moreover, we found that 6hub genes were upregulated in psoriasis skin lesions and IL-27 elevated the hub genes expression in M5-induced psoriasiform keratinocytes. IL-27 possibly promotes glycolysis, mitochondrial oxidative phosphorylation, and cell cycle progression in keratinocytes. Additionally, we identified CCNB1, PTTG1, CDC20, PLK1, PKM, and LDHA as hub genes that may be involved in the mechanism of IL-27 facilitating keratinocyte proliferation in psoriasis.

Astragaloside IV suppresses the proliferation and inflammatory response of human epidermal keratinocytes and ameliorates imiquimod-induced psoriasis-like skin damage in mice.

The primary pathological features of psoriasis include excessive epidermal keratinocytes and infiltration of inflammatory cells, which are pivotal targets for psoriasis therapy. Astragaloside IV (AS-IV), the principal active compound of astragalus, exhibits anti-inflammatory, antioxidant, and immune-modulatory properties. This study aims to investigate AS-IV's anti--psoriatic effects and underlying mechanisms. Normal human epidermal keratinocytes (NHEKs) were stimulated with a combination of TNF-α, IL-17A, IL-1α, IL-22, and oncostatin M (M5) to replicate psoriatic keratinocyte pathology in vitro. Cell proliferation was assessed using CCK8 and EDU staining. Pro-inflammatory cytokine levels were measured via qRT-PCR. In addition, an imiquimod (IMQ)-induced psoriasis mouse model was utilized. Skin histology changes were evaluated with HE staining, while IL-6 and TNF-α levels in mouse serum were quantified using ELISA. NF-κB pathway protein expression was analyzed by western blotting. The results demonstrated that AS-IV inhibited M5-induced proliferation of NHEKs. AS-IV reduced M5-stimulated IL-1β, IL-6, IL-8, TNF-α, IL-23, and MCP-1 expression in NHEKs. Moreover, M5-induced phosphorylation of IκBα and p65 was significantly attenuated by AS-IV. Furthermore, AS-IV application ameliorated erythema, scale formation, and epidermal thickening in IMQ-induced psoriasis-like mouse models. AS-IV also decreased IL-6 and TNF-α levels in mouse serum and inhibited IκBα and p65 phosphorylation in skin tissues. However, prostratin treatment reversed these effects. These findings underscore AS-IV's capacity to mitigate M5-induced NHEK proliferation and inflammation. AS-IV shows promise in alleviating IMQ-induced psoriasis-like skin lesions and inflammation by suppressing the NF-κB pathway.

O07 Lower doses of retinol facilitate cell proliferation and epidermal thickening in photoaged skin

Abstract Introduction and aims Chronic exposure to solar ultraviolet radiation leads to cutaneous hypertrophic photoageing which clinically manifests as wrinkles, skin laxity and hyperpigmentation. This photoaged phenotype is underscored by a remodelled cutaneous microenvironment including epidermal thinning and rete ridge flattening. We have previously shown that cosmeceutical formulations of 0.3% and 1% retinol can effectively induce epidermal thickening and keratinocyte proliferation. However, these concentrations require careful usage to limit potential irritancy issues, highlighting a need to explore the benefits of lower dose retinol for daily skincare. Therefore, we compare the efficacy of lower doses of retinol in facilitating epidermal thickness and proliferation in photoaged skin, as this currently remains unknown. Methods Using the in vivo Manchester Patch Test Assay, test substances (vehicle and retinol at concentrations of 0.025%, 0.05%, 0.1% and 1%) were applied under occlusion to extensor forearms of healthy but photoaged volunteers (three men, three women; age range 66–86 years) for 12 days. Resultant skin biopsies were processed for histological assessment of epidermal thickness and keratinocyte proliferation. Results Epidermal thickness was significantly increased with 0.025% (P < 0.05), 0.05%, 0.1% and 1% (all P < 0.01) retinol treatment, compared with baseline or vehicle. Immunofluorescence staining of the proliferation marker Ki67 identified elevated keratinocyte proliferation following retinol treatment (P < 0.05 for 0.025%, 0.05% and 1%) compared with baseline. Although Ki67 expression in the 0.1% retinol treatment was elevated, significance was not achieved compared with baseline. However, compared with the vehicle, all retinol concentrations significantly increased Ki67 expression (P < 0.05). Clinically, 50% of volunteers showed an erythemal irritancy response to 1% retinol only. Conclusions We established that lower doses of retinol are capable of inducing keratinocyte proliferation and epidermal thickening without irritancy issues. Therefore, long-term effective treatment of photoaged skin with low-dose retinol products may be the preferred choice for individuals where retinol sensitivity has previously been an issue.

CircCDK13-loaded small extracellular vesicles accelerate healing in preclinical diabetic wound models

Chronic wounds are a major complication in patients with diabetes. Here, we identify a therapeutic circRNA and load it into small extracellular vesicles (sEVs) to treat diabetic wounds in preclinical models. We show that circCDK13 can stimulate the proliferation and migration of human dermal fibroblasts and human epidermal keratinocytes by interacting with insulin-like growth factor 2 mRNA binding protein 3 in an N6-Methyladenosine-dependent manner to enhance CD44 and c-MYC expression. We engineered sEVs that overexpress circCDK13 and show that local subcutaneous injection into male db/db diabetic mouse wounds and wounds of streptozotocin-induced type I male diabetic rats could accelerate wound healing and skin appendage regeneration. Our study demonstrates that the delivery of circCDK13 in sEVs may present an option for diabetic wound treatment.

Diagnose und Therapie aktinischer Keratosen

Actinic keratosis (AK) is considered a chronic and recurring in situ skin neoplasia, with a possible transformation into invasive squamous cell carcinoma (SCC). Among others, predominant risk factors for development of AK are UV-light exposure and immunosuppression. Basal epidermal keratinocyte atypia (AK I) and proliferation (PRO Score) seem to drive malignant turnover, rather than clinical appearance of AK (Olsen I-III). Due to the invasiveness of punch biopsy, those histological criteria are not regularly assessed. Non-invasive imaging techniques, such as optical coherence tomography (OCT), reflectance confocal microscopy (RCM) and line-field confocal OCT (LC-OCT) are helpful to distinguish complex cases of AK, Bowen's disease and SCC. Moreover, LC-OCT can visualize the epidermis and the papillary dermis at cellular resolution, allowing real-time PRO Score assessment. The decision-making for implementation of therapy is still based on clinical risk factors, ranging from lesion- to field-targeted and ablative to non-ablative regimes, but in approximately 85% of the cases a recurrence of AK can be observed after a 1-year follow-up. The possible beneficial use of imaging techniques for a non-invasive follow-up of AK to detect recurrence or invasive progression early on should be subject to critical evaluation in further studies.

Abstract 6872: A spatio-temporal approach to mapping the dynamics of cutaneous squamous cell carcinoma progression and immunotherapy response: A journey through TiME

Abstract Background: Cutaneous squamous cell carcinoma (cSCC), arising from proliferation of malignant epidermal keratinocytes, is the second most common non-melanoma skin cancer. cSCC accounts for 75% of all skin cancer related deaths excluding melanoma, and metastatic and immunotherapy-resistant cases pose an emerging global threat. Tumor development is a gradual process characterized by high mutational burden and an immunosuppressive tumor immune microenvironment (TiME); therefore, identifying the underlying changes across the spatial and temporal landscape of these tumors will be crucial to understanding the key cellular and molecular drivers of disease progression and response. Methods: In this longitudinal study, we used a single-cell, whole-slide approach to mapping key proteins of immune lineage, tissue architecture, cellular metabolism, and stress to study the spatial landscape of cSCC at baseline (pre-treatment) and multiple time points over the course of immunotherapy with the aim to develop a temporal atlas of the tumor. An ultra-high plex antibody panel encompassing over 50 major determinants in the tumor microenvironment was employed on the PhenoCycler®-Fusion spatial biology platform. Deep bioinformatic analyses was performed to identify cellular phenotypes, spatial neighborhoods, heterogenous functional states and cellular interactions by spatial proximity determinations. Results: Previous studies in our laboratory have identified unique phenotypes correlating with response and resistance to immunotherapies in pre-treatment cSCC biopsies. Our results expand on these findings with temporal data tracking the dynamic changes in the TiME over the course of immune checkpoint inhibitor therapy. Apart from differences in immune cell composition and spatial localization patterns, we also saw differences in macrophage polarization and expression of metabolic markers in the responder and non-responder cohorts. Conclusions: Overall, ultrahigh-plex spatio-temporal monitoring of cSCC revealed distinct signatures of response and resistance and identified key features in the TiME that reveal deeper insights into the pathobiology of the tumor. Our discovery-based approach identifies novel biomarkers for patient stratification and therapeutic modulation. Citation Format: Niyati Jhaveri, Bassem Ben Cheikh, Dmytro Klymyshyn, Ning Ma, Aditya Pratapa, James Monkman, Nadine Nelson, Arutha Kulasinghe. A spatio-temporal approach to mapping the dynamics of cutaneous squamous cell carcinoma progression and immunotherapy response: A journey through TiME [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6872.

Phloroglucinol Enhances Anagen Signaling and Alleviates H2O2-Induced Oxidative Stress in Human Dermal Papilla Cells.

Phloroglucinol (PG) is one of the abundant isomeric benzenetriols in brown algae. Due to its polyphenolic structure, PG exhibits various biological activities. However, the impact of PG on anagen signaling and oxidative stress in human dermal papilla cells (HDPCs) is unknown. In this study, we investigated the therapeutic potential of PG for improving hair loss. A non-cytotoxic concentration of PG increased anagen-inductive genes and transcriptional activities of β-Catenin. Since several anagen-inductive genes are regulated by β-Catenin, further experiments were performed to elucidate the molecular mechanism by which PG upregulates anagen signaling. Various biochemical analyses revealed that PG upregulated β-Catenin signaling without affecting the expression of Wnt. In particular, PG elevated the phosphorylation of protein kinase B (AKT), leading to an increase in the inhibitory phosphorylation of glycogen synthase kinase 3 beta (GSK3β) at serine 9. Treatment with the selective phosphoinositide 3-kinase/AKT inhibitor, LY294002, restored the increased AKT/GSK3β/β-Catenin signaling and anagen-inductive proteins induced by PG. Moreover, conditioned medium from PG-treated HDPCs promoted the proliferation and migration of human epidermal keratinocytes via the AKT signaling pathway. Subsequently, we assessed the antioxidant activities of PG. PG ameliorated the elevated oxidative stress markers and improved the decreased anagen signaling in hydrogen peroxide (H2O2)-induced HDPCs. The senescence-associated β-galactosidase staining assay also demonstrated that the antioxidant abilities of PG effectively mitigated H2O2-induced senescence. Overall, these results indicate that PG potentially enhances anagen signaling and improves oxidative stress-induced cellular damage in HDPCs. Therefore, PG can be employed as a novel therapeutic component to ameliorate hair loss symptoms.

Diagnosis and therapy of actinic keratosis.

Actinic keratosis (AK) is considered a chronic and recurring in situ skin neoplasia, with a possible transformation into invasive squamous cell carcinoma (SCC). Among others, predominant risk factors for development of AK are UV-light exposure and immunosuppression. Basal epidermal keratinocyte atypia (AK I) and proliferation (PRO score) seem to drive malignant transformation, rather than clinical appearance of AK (Olsen I-III). Due to the invasiveness of punch biopsy, those histological criteria are not regularly assessed. Non-invasive imaging techniques, such as optical coherence tomography (OCT), reflectance confocal microscopy (RCM) and line-field confocal OCT (LC-OCT) are helpful to distinguish complex cases of AK, Bowen's disease, and SCC. Moreover, LC-OCT can visualize the epidermis and the papillary dermis at cellular resolution, allowing real-time PRO score assessment. The decision-making for implementation of therapy is still based on clinical risk factors, ranging from lesion- to field-targeted and ablative to non-ablative regimens, but in approximately 85% of the cases a recurrence of AK can be observed after a 1-year follow-up. The possible beneficial use of imaging techniques for a non-invasive follow-up of AK to detect recurrence or invasive progression early on should be subject to critical evaluation in further studies.

Novel Placenta-Derived Liquid Product Suitable for Cosmetic Application Produced by Fermentation and Digestion of Porcine or Equine Placenta Using Lactic Acid Bacterium Enterococcus faecalis PR31

Since ancient times, the placenta has been used to produce cosmetic and health food products, whereas fermentation is a technology that has been used to produce foods and cosmetics. For application in cosmetics, traditional placental extracts produced solely by proteolysis have not had enough moisturizing properties or the ability to stimulate the proliferation of epidermal keratinocytes. We combined these two traditional approaches to produce raw materials without such drawbacks that are suitable for cosmetic applications. Using a unique lactic acid bacterial strain, Enterococcus faecalis PR31, to directly ferment and digest both porcine and equine placentas, we produced the following liquid products: placenta ferment filtrates. The ferment filtrates stimulated the proliferation of not only normal human dermal fibroblasts but also epidermal keratinocytes. The ferments had higher equilibrium water content properties than traditional placental extracts, and the ferment derived from the porcine placenta maintained high stratum corneum water content levels for up to 6 h after its application on the skin. Metabolome analysis revealed various molecules that were increased by fermentation, among which lactic acid was assumed to play a central role in the high moisturizing properties. To conclude, the placenta ferment filtrates developed in this study are beneficial for cosmetic applications.

Exploring the Effectiveness of Biological Therapy in Patients with Psoriasis: Body Image and Quality of Life.

Background and Objectives: Psoriasis is a chronic, long-term, incurable skin inflammatory disease characterized by the excessive proliferation of epidermal keratinocytes, dilation of blood vessels, thickening of the skin, and the formation of visible red patches of variable sizes. The impact on patients differs with the severity of the disease, leading to physiological discomfort and psychological distress, which significantly affect the quality of life. The etiology of psoriasis is not completely clear, but immune cells, including type 1 and type 17 cytokine-producing cells modulated by regulatory T cells (Tregs), play a critical role in driving the disease pathogenesis. With the ability to specifically target inflammatory markers, biologics can efficiently inhibit the spread of inflammation to achieve therapeutic effects. The goal was to explore the changes in body image and quality of life in psoriasis patients undertaking therapies with biologic agents. Materials and Methods: This study employed a quasi-experimental, single-sample, pretest-posttest design. Forty-four psoriasis patients were recruited from the dermatology outpatient clinics at two medical centers in northern Taiwan. A structured questionnaire, including demographic information, the Body Image Scale (BIS), and the Dermatology Life Quality Index (DLQI), was used as a research tool. Questionnaire assessments were conducted both before and three months after the biologic agent intervention. Statistical analyses were performed using SPSS version 22.0. Results: Our results indicated a significant difference in body image between psoriasis patients before and after intervention with biologic agents. In addition, overall quality of life (QoL) also showed significant improvements before and after biologic agent intervention. There was a positive correlation between body image and quality of life in psoriasis patients. Conclusions: The treatment for psoriasis has evolved rapidly in recent years, and biologic agents have proven to be effective therapies to improve the quality of life for psoriasis patients. Our study suggests that health-related education and psychological support can further benefit psoriasis patients to willingly and positively undertake treatment and therefore improve their positive body image and quality of life.

Complement C3 deficient mice show more severe imiquimod-induced psoriasiform dermatitis than wild-type mice regardless of the commensal microbiota.

The complement active product, C3a, and the receptor C3aR comprise an axis that exerts various biological functions, such as protection against infection. C3a is highly expressed in the inflamed skin and blood from patients with psoriasiform dermatitis. However, the role of the C3a/C3aR axis in psoriasiform dermatitis remains unclear because conflicting results using C3-/- mice have been published. In this study, to elucidate the contribution of commensal microbiota in C3-/- and wild-type (WT) mice were subjected to imiquimod-induced psoriasiform dermatitis under different housing conditions. C3-/- mice showed increased epidermal thickness and keratinocyte proliferation markers in the inflamed ear compared to WT mice upon treatment with IMQ. These inflamed phenotypes were observed in both cohoused and separately housed conditions, and antibiotic treatment did not abolish the aggravation of IMQ-induced psoriasiform dermatitis in C3-/- mice. These results suggested that the difference of commensal microbiota is not important for the C3-involved psoriasiform dermatitis. Keratinocyte hyperproliferation is a major feature of the inflamed skin in patients with psoriasiform dermatitis. In vitro experiments showed that C3a and C3aR agonists inhibited keratinocyte proliferation, which was abolished by introduction of a C3aR antagonist. Collectively, these results suggest that the C3a/C3aR axis plays a critical role in psoriasiform dermatitis development by inhibiting keratinocyte proliferation, regardless of the regulation of the commensal microbiota.

Vascular Endothelial Growth Factor A VEGFA Inhibition: An Effective Treatment Strategy for Psoriasis.

Psoriasis is an inflammatory skin disease mediated by the immune system and characterized by an inflammatory ring, also known as an epithelial immune microenvironment (EIME). The interaction between the epithelial tissue of the skin and the immune system has a crucial role in the immune cycle of psoriasis. Although the formation of new blood vessels in skin lesions provides energy support for the proliferation of epidermal keratinocytes, the role of angiogenesis in psoriasis has not been extensively studied. Vascular endothelial growth factor A (VEGFA) is a key regulator of angiogenesis that has an important role in the development of psoriasis. VEGFA promotes angiogenesis and directly stimulates epidermal keratinocytes and infiltrating immune cells, thus contributing to the progression of psoriasis. Measuring VEGFA levels to identify angiogenic characteristics in psoriasis patients may be a predictive biomarker for disease severity and response to anti-angiogenic therapy. Clinical data have shown that anti-angiogenic therapy can improve skin lesions in psoriasis patients. Therefore, this study aimed to uncover the underestimated role of blood vessels in psoriasis, explore the relationship between VEGFA and keratinocytes in the EIME, and inspire innovative drug therapies for the treatment of psoriasis.

A Route for Investigating Psoriasis: From the Perspective of the Pathological Mechanisms and Therapeutic Strategies of Cancer.

Psoriasis is an incurable skin disease that develops in about two-thirds of patients before the age of 40 and requires lifelong treatment; its pathological mechanisms have not been fully elucidated. The core pathological process of psoriasis is epidermal thickening caused by the excessive proliferation of epidermal keratinocytes, which is similar to the key feature of cancer; the malignant proliferation of cancer cells causes tumor enlargement, suggesting that there is a certain degree of commonality between psoriasis and cancer. This article reviews the pathological mechanisms that are common to psoriasis and cancer, including the interaction between cell proliferation and an abnormal immune microenvironment, metabolic reprogramming, and epigenetic reprogramming. In addition, there are common therapeutic agents and drug targets between psoriasis and cancer. Thus, psoriasis and cancer share a common pathological mechanisms-drug targets-therapeutic agents framework. On this basis, it is proposed that investigating psoriasis from a cancer perspective is beneficial to enriching the research strategies related to psoriasis.

Effects of Schumann resonance on the proliferation and migration of normal human epidermal keratinocytes and the expression of DEFB1 and SIRT1.

When the skin is damaged and its barrier function is disrupted, the proliferation and migration of epidermal keratinocytes are vital for repairing the damaged area. The Schumann resonance at 7.8 Hz has been reported to protect rat cardiomyocytes against oxidative stress and inhibit the proliferation of B16 mouse melanoma cells. However, its effect on the skin is unknown. In this study, we applied 7.8-Hz electromagnetic waves to normal human epidermal keratinocytes (NHEKs) and investigated its effects on cell proliferation and migration, β-defensin (DEFB1) and sirtuin 1 (SIRT1) expression. We performed cell proliferation assay, cell migrationassay and gene expression analysis of DEFB1 and SIRT1. We found that the application of 7.8-Hz electromagnetic waves caused a 2.8-fold increase in NHEK proliferation, enhanced cell migration, and increased the expression of DEFB1 and SIRT1 by 2.4-fold and 4.9-fold, respectively. These results suggest that the application of 7.8-Hz electromagnetic waves may contribute to improving the skin barrier function and skin ulcer.

Cellular Mechanisms of Psoriasis Pathogenesis: A Systemic Review.

Psoriasis is a common inflammatory skin disease characterized by abnormal proliferation of epidermal keratinocytes and massive infiltration of inflammatory cells. Many kinds of cells, including keratinocytes, T lymphocytes, dendritic cells, neutrophils, and macrophages, are reported to play critical roles in the pathogenesis and progression of psoriasis. However, to date, the role of each kind of cell in the pathogenesis and development of psoriasis has not been systematically reviewed. In addition, although antibodies developed targeting cytokines (e.g. IL-23, IL-17A, and TNF-α) released by these cells have shown promising results in the treatment of psoriasis patients, these targeted antibodies still do not cure psoriasis and only provide short-term relief of symptoms. Furthermore, long-term use of these antibodies has been reported to have adverse physical and psychological effects on psoriasis patients. Therefore, gaining a deeper understanding of the cellular and molecular pathogenesis of psoriasis and providing new thoughts on the development of psoriasis therapeutic drugs is of great necessity. In this review, we summarize the roles of various cells involved in psoriasis, aiming to provide new insights into the pathogenesis and development of psoriasis at the cellular level and hoping to provide new ideas for exploring new and effective psoriasis treatments.

Eicosapentaenoic acid reduces the proportion of IL-17A–producing T cells in a 3D psoriatic skin model

Psoriasis is a skin disease presenting as erythematous lesions with accentuated proliferation of epidermal keratinocytes, infiltration of leukocytes, and dysregulated lipid metabolism. T cells play essential roles in the disease. n-3 polyunsaturated fatty acids are anti-inflammatory metabolites, which exert an immunosuppressive effect on healthy T cells. However, the precise mechanistic processes of n-3 polyunsaturated fatty acids on T cells in psoriasis are still unrevealed. In this study, we aimed to evaluate the action of eicosapentaenoic acid (EPA) on T cells in a psoriatic skin model produced with T cells. A coculture of psoriatic keratinocytes and polarized T cells was prepared using culture media, which was either supplemented with 10 μM EPA or left unsupplemented. Healthy and psoriatic skin substitutes were produced according to the self-assembly method. In the coculture model, EPA reduced the proportion of IL-17A–positive cells, while increasing that of FOXP3-positive cells, suggesting an increase in the polarization of regulatory T cells. In the 3D psoriatic skin model, EPA normalized the proliferation of psoriatic keratinocytes and diminished the levels of IL-17A. The expression of the proteins of the signal transducer and activator of transcription was influenced following EPA supplementation with downregulation of the phosphorylation levels of signal transducer and activator of transcription 3 in the dermis. Finally, the NFκB signaling pathway was modified in the EPA-supplemented substitutes with an increase in Fas amounts. Ultimately, our results suggest that in this psoriatic model, EPA exerts its anti-inflammatory action by decreasing the proportion of IL-17A–producing T cells.

Tirbanibulin 1% Ointment Significantly Reduces the Actinic Keratosis Area and Severity Index in Patients with Actinic Keratosis: Results from a Real-World Study.

Actinic keratosis (AK) is a cutaneous lesion resulting from the proliferation of atypical epidermal keratinocytes caused by long-term exposure to ultraviolet radiation. AK may progress to cutaneous squamous cell carcinoma (cSCC) and therefore is often treated with topical agents such as 5-fluorouracil, diclofenac, imiquimod, and photodynamic therapy. Tirbanibulin has been approved based on two phase III trials in the USA. However, real-world evidence for tirbanibulin is absent. This was a single-centre study of adult patients with clinically typical, visible AK on the face or scalp treated with tirbanibulin 1% ointment. Treatment was administered as per label once daily for 5 consecutive days on the same lesions or field. Treatment outcomes were assessed 4 weeks after treatment, with additional optional assessments conducted at later time points. Efficacy was measured using the actinic keratosis area and severity index (AKASI) and digital dermoscopy. A total of 33 patients were treated of whom 30 were analysed. The median AKASI score was 5.6 (1.4-11) pre-treatment and 1.2 (0-7.4) post-treatment (p < 0.0001). Complete clearance as defined by AKASI scores less than 1 was achieved in 47% (n = 14) and 57% (n = 13) at the first and second follow-up, respectively. All local reactions resolved spontaneously and without sequelae. The most common local reactions were erythema (80%, n = 26) and flaking or scaling (43%, n = 13). Tirbanibulin 1% ointment significantly and rapidly reduced the AKASI score in a real-world setting. The complete clearance rates were in line with those observed in the two pivotal trials.

Vitamin D receptor cross-talk with p63 signaling promotes epidermal cell fate

The vitamin D receptor with its ligand 1,25 dihydroxy vitamin D3 (1,25D3) regulates epidermal stem cell fate, such that VDR removal from Krt14 expressing keratinocytes delays re-epithelialization of epidermis after wound injury in mice. In this study we deleted Vdr from Lrig1 expressing stem cells in the isthmus of the hair follicle then used lineage tracing to evaluate the impact on re-epithelialization following injury. We showed that Vdr deletion from these cells prevents their migration to and regeneration of the interfollicular epidermis without impairing their ability to repopulate the sebaceous gland. To pursue the molecular basis for these effects of VDR, we performed genome wide transcriptional analysis of keratinocytes from Vdr cKO and control littermate mice. Ingenuity Pathway analysis (IPA) pointed us to the TP53 family including p63 as a partner with VDR, a transcriptional factor that is essential for proliferation and differentiation of epidermal keratinocytes. Epigenetic studies on epidermal keratinocytes derived from interfollicular epidermis showed that VDR is colocalized with p63 within the specific regulatory region of MED1 containing super-enhancers of epidermal fate driven transcription factor genes such as Fos and Jun. Gene ontology analysis further implicated that Vdr and p63 associated genomic regions regulate genes involving stem cell fate and epidermal differentiation. To demonstrate the functional interaction between VDR and p63, we evaluated the response to 1,25(OH)2D3 of keratinocytes lacking p63 and noted a reduction in epidermal cell fate determining transcription factors such as Fos, Jun. We conclude that VDR is required for the epidermal stem cell fate orientation towards interfollicular epidermis. We propose that this role of VDR involves cross-talk with the epidermal master regulator p63 through super-enhancer mediated epigenetic dynamics.