scholarly journals IL-24 Negatively Regulates Keratinocyte Differentiation Induced by Tapinarof, an Aryl Hydrocarbon Receptor Modulator: Implication in the Treatment of Atopic Dermatitis

2020 ◽  
Vol 21 (24) ◽  
pp. 9412
Author(s):  
Yen Hai Vu ◽  
Akiko Hashimoto-Hachiya ◽  
Masaki Takemura ◽  
Ayako Yumine ◽  
Yasutaka Mitamura ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Aryl Hydrocarbon Receptor ◽  
Skin Barrier ◽  
Janus Kinase ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Dependent Manner ◽  
Jak Inhibitors ◽  
Barrier Dysfunction ◽  
Aryl Hydrocarbon

Skin barrier dysfunction, including reduced filaggrin (FLG) and loricrin (LOR) expression, plays a critical role in atopic dermatitis (AD) development. Since aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, mediates keratinocyte differentiation, it is a potential target for AD treatment. Recently, clinical studies have shown that tapinarof, an AHR modulator, attenuated the development of AD. To examine the molecular mechanism involved in this, we analyzed tapinarof-treated normal human epidermal keratinocytes (NHEKs). Tapinarof upregulated FLG and LOR mRNA and protein expression in an AHR-dependent manner. Tapinarof also induced the secretion of IL-24, a cytokine that activates Janus kinase (JAK)-signal transducer and activator of transcription (STAT), leading to the downregulation of FLG and LOR expression. Knockdown of either IL-24 or STAT3 expression by small interfering RNA (siRNA) transfection augmented the upregulation of FLG and LOR expression induced by tapinarof, suggesting that inhibition of the IL-24/STAT3 axis during AHR activation supports the improvement of skin barrier dysfunction. Furthermore, tapinarof alone could restore the downregulation of FLG and LOR expression induced by IL-4, a key cytokine of AD, and its combination with JAK inhibitors enhanced this effect. These findings provide a new strategy for treating AD using AHR modulators and JAK inhibitors.

scholarly journals Commensal Microbiota Regulates Skin Barrier Function And Repair Via Signaling Through The Aryl Hydrocarbon Receptor

2020 ◽  
Author(s):  
Aayushi Uberoi ◽  
Casey Bartow-McKenney ◽  
Qi Zheng ◽  
Laurice Flowers ◽  
Amy Campbell ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Skin Barrier ◽  
The Body ◽  
Epidermal Differentiation ◽  
Skin Barrier Function ◽  
Dependent Manner ◽  
Skin Microbiome ◽  
Barrier Dysfunction ◽  
Epidermal Barrier ◽  
Aryl Hydrocarbon

SUMMARYThe epidermis forms a barrier that defends the body from desiccation and entry of harmful substances, while sensing and integrating environmental signals. The tightly orchestrated cellular changes required for the proper formation and maintenance of this epidermal barrier occur in the context of the skin microbiome. Using germ free mice, we demonstrate the microbiota is necessary for proper differentiation and repair of the epidermal barrier. These effects were mediated by the aryl hydrocarbon receptor (AHR) in keratinocytes, a xenobiotic receptor also implicated in epidermal differentiation. Murine skin lacking keratinocyte AHR was more susceptible to barrier damage and infection, during steady state and epicutaneous sensitization. Colonization with a defined consortium of human skin isolates restored barrier competence in an AHR-dependent manner. We reveal a fundamental mechanism whereby the microbiota regulates skin barrier formation and repair, with far-reaching implications for the numerous skin disorders characterized by epidermal barrier dysfunction.

scholarly journals Aryl Hydrocarbon Receptor in Atopic Dermatitis and Psoriasis

2019 ◽  
Vol 20 (21) ◽  
pp. 5424 ◽  
Author(s):  
Masutaka Furue ◽  
Akiko Hashimoto-Hachiya ◽  
Gaku Tsuji
Keyword(s):  
Oxidative Stress ◽  
Atopic Dermatitis ◽  
Aryl Hydrocarbon Receptor ◽  
T Regulatory Cells ◽  
Skin Barrier ◽  
Related Factor ◽  
T Helper 17 ◽  
Aryl Hydrocarbon ◽  
Sensitive Sensor ◽  
Tryptophan Photoproducts

The aryl hydrocarbon receptor (AHR)/AHR-nuclear translocator (ARNT) system is a sensitive sensor for small molecular, xenobiotic chemicals of exogenous and endogenous origin, including dioxins, phytochemicals, microbial bioproducts, and tryptophan photoproducts. AHR/ARNT are abundantly expressed in the skin. Once activated, the AHR/ARNT axis strengthens skin barrier functions and accelerates epidermal terminal differentiation by upregulating filaggrin expression. In addition, AHR activation induces oxidative stress. However, some AHR ligands simultaneously activate the nuclear factor-erythroid 2-related factor-2 (NRF2) transcription factor, which is a master switch of antioxidative enzymes that neutralizes oxidative stress. The immunoregulatory system governing T-helper 17/22 (Th17/22) and T regulatory cells (Treg) is also regulated by the AHR system. Notably, AHR agonists, such as tapinarof, are currently used as therapeutic agents in psoriasis and atopic dermatitis. In this review, we summarize recent topics on AHR related to atopic dermatitis and psoriasis.

scholarly journals Aryl Hydrocarbon Receptor Activation Downregulates IL-33 Expression in Keratinocytes via Ovo-Like 1

2020 ◽  
Vol 9 (3) ◽  
pp. 891 ◽  
Author(s):  
Gaku Tsuji ◽  
Akiko Hashimoto-Hachiya ◽  
Vu Hai Yen ◽  
Sho Miake ◽  
Masaki Takemura ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Aryl Hydrocarbon Receptor ◽  
Crucial Role ◽  
Receptor Activation ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes ◽  
Aryl Hydrocarbon ◽  
Normal Human Epidermal Keratinocytes ◽  
Normal Human ◽  
Susceptible Gene

Background: IL-33, one of the IL-1 superfamily cytokines, has been shown to be associated with pruritus and inflammation in atopic dermatitis (AD). Furthermore, IL-33 production derived from keratinocytes reportedly has a crucial role in the development of AD; however, the mechanism of IL-33 expression has not been fully understood. Methods: We analyzed IL-33 expression in normal human epidermal keratinocytes (NHEKs) treated with IL-4. Results: IL-4 induced the upregulation of IL-33 expression in NHEKs. Based on the findings 1) that ovo-like 1 (OVOL1), a susceptible gene of AD, upregulates filaggrin (FLG) and loricrin (LOR) expression in NHEKs and 2) that reduced expression of FLG and LOR leads to production of IL-1 superfamily cytokines, we examined the involvement of OVOL1 in IL-33 expression in NHEKs. Knockdown of OVOL1 induced upregulation of IL-33 expression. Moreover, because Glyteer, an activator of aryl hydrocarbon receptor (AHR), reportedly upregulates OVOL1 expression, we examined whether treatment with Glyteer inhibited IL-33 expression in NHEKs. Treatment with Glyteer inhibited IL-4-induced upregulation of IL-33 expression, which was canceled by knockdown of either AHR or OVOL1. Conclusions: Activation of the AHR-OVOL1 axis inhibits IL-4-induced IL-33 expression, which could be beneficial for the treatment of AD.

scholarly journals A molecular mechanism for IL-4 suppression of loricrin transcription in epidermal keratinocytes: implication for atopic dermatitis pathogenesis

2017 ◽  
Vol 23 (8) ◽  
pp. 641-647 ◽  
Author(s):  
Lei Bao ◽  
Girish C Mohan ◽  
Jaime B Alexander ◽  
Caroline Doo ◽  
Kui Shen ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Molecular Mechanism ◽  
Specific Inhibitor ◽  
Skin Barrier ◽  
Human Keratinocytes ◽  
Epidermal Keratinocytes ◽  
Dependent Manner ◽  
Down Regulation ◽  
Important Barrier ◽  
First Time

Skin barrier defects play an important role in atopic dermatitis (AD) pathogenesis. Loricrin, an important barrier protein suppressed in human AD, is down-regulated by IL-4 in keratinocytes. However, the molecular mechanism is unknown. Since loricrin transcription requires p300/CBP, and Stat6 also recruits this common coactivator for its stimulated factors, we hypothesize that IL-4-activated Stat6 competes for the available endogenous p300/CBP, leading to loricrin transcription inhibition. First, we showed that loricrin is suppressed in the skin of IL-4 transgenic mice, an AD mouse model. In human keratinocytes, IL-4 down-regulation of loricrin is abrogated by a pan-Jak inhibitor, suggesting that the Jak-Stat pathway is involved. To further investigate the downstream molecular mechanism, we transfected HaCat cells with a loricrin promoter and then treated them with either IL-4 or vehicle. Not surprisingly, IL-4 greatly suppressed the promoter activity. Interestingly, this suppression was prevented when we knocked down Stat6, indicating that Stat6 participates in IL-4 regulation of loricrin. A Stat6-specific inhibitor confirmed the knockdown study. Finally, IL-4 suppression of loricrin was reversed with transfection of a CBP expression vector in a dose-dependent manner. Taken together, for the first time, we delineate a molecular mechanism for IL-4 down-regulation of loricin expression in human keratinocytes, which may play an important role in AD pathogenesis.

scholarly journals Aryl hydrocarbon receptor-dependence of dioxin’s effects on constitutive mouse hepatic cytochromes P450 and growth hormone signaling components

2012 ◽  
Vol 90 (10) ◽  
pp. 1354-1363 ◽  
Author(s):  
Chunja Lee ◽  
David S. Riddick
Keyword(s):  
Growth Hormone ◽  
Cytochrome P450 ◽  
Aryl Hydrocarbon Receptor ◽  
Target Genes ◽  
Janus Kinase ◽  
Specific Gene ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Aryl Hydrocarbon ◽  
Signaling Components

The aryl hydrocarbon receptor (AHR) has physiological roles in the absence of exposure to exogenous ligands, and mediates adaptive and toxic responses to the environmental pollutant 2,3,7,8-tetracholorodibenzo-p-dioxin (TCDD). A readily metabolized AHR agonist, 3-methylcholanthrene, disrupts the expression of mouse hepatic growth hormone (GH) signaling components and suppresses cytochrome P450 2D9 (Cyp2d9), a male-specific gene controlled by pulsatile GH via signal transducer and activator of transcription 5b (STAT5b). Using TCDD as an essentially nonmetabolized AHR agonist, and Ahr −/− mice as the preferred model to determine the AHR-dependence of biological responses, we now show that 2 mouse hepatic STAT5b target genes, Cyp2d9, and major urinary protein 2 (Mup2), are suppressed by TCDD in an AHR-dependent manner. TCDD also decreased hepatic mRNA levels for GH receptor, Janus kinase 2, and STAT5a/b with AHR-dependence. Without inducing selected hepatic inflammatory markers, TCDD caused AHR-dependent induction of Cyp1a1 and NADPH-cytochrome P450 oxidoreductase (Por) and suppression of Cyp3a11. In vehicle-treated mice, basal mRNA levels for CYP2D9, CYP3A11, POR, serum amyloid protein P, and MUP2 were influenced by Ahr genetic status. We conclude that AHR activation per se leads to dysregulation of hepatic GH signaling components and suppression of some, but not all, STAT5b target genes.

scholarly journals A novel mineralocorticoid receptor antagonist, 7,3',4'-trihydroxyisoflavone improves skin barrier function impaired by endogenous or exogenous glucocorticoids

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hanil Lee ◽  
Eun-Jeong Choi ◽  
Eun Jung Kim ◽  
Eui Dong Son ◽  
Hyoung-June Kim ◽  
...  
Keyword(s):  
Barrier Function ◽  
Nuclear Translocation ◽  
Clinical Investigation ◽  
Therapeutic Option ◽  
Skin Barrier ◽  
Keratinocyte Differentiation ◽  
Skin Barrier Function ◽  
Epidermal Keratinocytes ◽  
Barrier Dysfunction ◽  
Mineralocorticoid Receptor Antagonist

AbstractExcess glucocorticoids (GCs) with either endogenous or exogenous origins deteriorate skin barrier function. GCs bind to mineralocorticoid and GC receptors (MRs and GRs) in normal human epidermal keratinocytes (NHEKs). Inappropriate MR activation by GCs mediates various GC-induced cutaneous adverse events. We examined whether MR antagonists can ameliorate GC-mediated skin barrier dysfunction in NHEKs, reconstructed human epidermis (RHE), and subjects under psychological stress (PS). In a preliminary clinical investigation, topical MR antagonists improved skin barrier function in topical GC-treated subjects. In NHEKs, cortisol induced nuclear translocation of GR and MR, and GR and MR antagonists inhibited cortisol-induced reductions of keratinocyte differentiation. We identified 7,3’,4’-trihydroxyisoflavone (7,3’,4’-THIF) as a novel compound that inhibits MR transcriptional activity by screening 30 cosmetic compounds. 7,3’,4’-THIF ameliorated the cortisol effect which decreases keratinocyte differentiation in NHEKs and RHE. In a clinical study on PS subjects, 7,3',4'-THIF (0.1%)-containing cream improved skin barrier function, including skin surface pH, barrier recovery rate, and stratum corneum lipids. In conclusion, skin barrier dysfunction owing to excess GC is mediated by MR and GR; thus, it could be prevented by treatment with MR antagonists. Therefore, topical MR antagonists are a promising therapeutic option for skin barrier dysfunction after topical GC treatment or PS.

scholarly journals EGFR inhibitors switch keratinocytes from a proliferative to a differentiative phenotype affecting epidermal development and barrier function

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nicolas Joly-Tonetti ◽  
Thomas Ondet ◽  
Mario Monshouwer ◽  
Georgios N. Stamatas
Keyword(s):  
Growth Factor ◽  
Barrier Function ◽  
Kinase Inhibitors ◽  
Treatment Protocol ◽  
Growth Factor Receptor ◽  
Skin Barrier ◽  
Keratinocyte Differentiation ◽  
Skin Barrier Function ◽  
Epidermal Keratinocytes ◽  
Epidermal Structure

Abstract Background Cutaneous adverse drug reactions (CADR) associated with oncology therapy involve 45–100% of patients receiving kinase inhibitors. Such adverse reactions may include skin inflammation, infection, pruritus and dryness, symptoms that can significantly affect the patient’s quality of life. To prevent severe skin damages dose adjustment or drug discontinuation is often required, interfering with the prescribed oncology treatment protocol. This is particularly the case of Epidermal Growth Factor Receptor inhibitors (EGFRi) targeting carcinomas. Since the EGFR pathway is pivotal for epidermal keratinocytes, it is reasonable to hypothesize that EGFRi also affect these cells and therefore interfere with the epidermal structure formation and skin barrier function. Methods To test this hypothesis, the effects of EGFRi and Vascular Endothelial Growth Factor Receptor inhibitors (VEGFRi) at therapeutically relevant concentrations (3, 10, 30, 100 nM) were assessed on proliferation and differentiation markers of human keratinocytes in a novel 3D micro-epidermis tissue culture model. Results EGFRi directly affect basal keratinocyte growth, leading to tissue size reduction and switching keratinocytes from a proliferative to a differentiative phenotype, as evidenced by decreased Ki67 staining and increased filaggrin, desmoglein-1 and involucrin expression compared to control. These effects lead to skin barrier impairment, which can be observed in a reconstructed human epidermis model showing a decrease in trans-epidermal water loss rates. On the other hand, pan-kinase inhibitors mainly targeting VEGFR barely affect keratinocyte differentiation and rather promote a proliferative phenotype. Conclusions This study contributes to the mechanistic understanding of the clinically observed CADR during therapy with EGFRi. These in vitro results suggest a specific mode of action of EGFRi by directly affecting keratinocyte growth and barrier function.

scholarly journals Effects of mineral complex material treatment on 2,4- dinitrochlorobenzene-induced atopic dermatitis like-skin lesions in mice model

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Johny Bajgai ◽  
Jing Xingyu ◽  
Ailyn Fadriquela ◽  
Rahima Begum ◽  
Dong Heui Kim ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Water Loss ◽  
Immunoglobulin E ◽  
Skin Barrier ◽  
Skin Lesions ◽  
Total Serum ◽  
Skin Barrier Function ◽  
Barrier Dysfunction ◽  
Complex Material ◽  
Mineral Complex

Abstract Background Atopic dermatitis (AD) is a chronic allergic inflammatory skin disease characterized by complex pathogenesis including skin barrier dysfunction, immune-redox disturbances, and pruritus. Prolonged topical treatment with medications such as corticosteroids, calcineurin inhibitors, and T-cell inhibitors may have some potential side-effects. To this end, many researchers have explored numerous alternative therapies using natural products and mineral compounds with antioxidant or immunomodulatory effects to minimize toxicity and adverse-effects. In the current study, we investigated the effects of mineral complex material (MCM) treatment on 2, 4-dinitrochlorobenzene (DNCB)-induced AD-like skin lesions in SKH-1 hairless mice. Methods Animals were divided into four groups; normal control (NC), negative control treated with DNCB only (DNCB only), positive control treated with DNCB and tacrolimus ointment (PC) and experimental group treated with DNCB and MCM patch (MCM). Skin inflammation and lesion severity were investigated through analyses of skin parameters (barrier score and strength, moisture and trans-epidermal water loss level), histopathology, immunoglobulin E, and cytokines. In addition, reactive oxygen species (ROS), nitric oxide (NO), glutathione peroxidase (GPx), and catalase (CAT) levels were measured in both serum and skin lysate. Results Our results demonstrates that MCM patch improved the progression of AD-like skin lesions by significantly increasing skin barrier strength and decreasing trans-epidermal water loss. Additionally, dermal administration of MCM patch significantly reduced epidermal thickness, ROS, and NO levels in skin lysate. Furthermore, we found that MCM suppressed the levels of AD-involved (Th1 and Th2) cytokines such as IL-2, IFN-γ, and IL-4 in blood. In addition, the levels of other Th1, and Th2 and inflammatory cytokines such as IL-1β, TNF-α, IL-6, IL-12(p70) and IL-10 were found lowest in the MCM group than in the DNCB only and PC groups. Moreover, we found total serum IgE level significantly increased after DNCB treatment, but decreased in the PC and MCM groups. Conclusion Taken together, our findings suggest that MCM application may have beneficial effects either systemic or regional on DNCB-induced AD lesional skin via regulation of the skin barrier function and immune-redox response.

scholarly journals Update on Atopic Dermatitis

2019 ◽  
Vol 32 (9) ◽  
pp. 606 ◽  
Author(s):  
Tiago Torres ◽  
Eduarda Osório Ferreira ◽  
Margarida Gonçalo ◽  
Pedro Mendes-Bastos ◽  
Manuela Selores ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Disease Severity ◽  
Clinical Manifestations ◽  
Skin Barrier ◽  
Future Research ◽  
Severe Atopic Dermatitis ◽  
Inadequate Response ◽  
Barrier Dysfunction ◽  
Therapeutic Goals ◽  
Global Health Issue

With an increasing prevalence during the past decades, atopic dermatitis has become a global health issue. A literature search following a targeted approach was undertaken to perform this non-systematic review, which intends to provide an overview of the epidemiology, pathophysiology, clinical features, comorbidities, and current therapies for the treatment of atopic dermatitis. In sum, this is a heterogeneous skin disorder associated with variable morphology, distribution, and disease course. Although not completely understood, its pathogenesis is complex and seems to result from a combination of genetic and environmental factors that induce skin barrier dysfunction, cutaneous and systemic immune dysregulation, skin microbiota dysbiosis, and a strong genetic influence. Diagnosis is based on specific criteria that consider patient and family history and clinical manifestations. Overall disease severity must be determined by evaluating both objective signs and subjective symptoms. Therapeutic goals require a multistep approach, focusing on reducing pruritus and establishing disease control. Patients should be advised on basic skin care and avoidance of triggers. Topical anti-inflammatory agents should be considered in disease flares or chronic/recurrent lesions. In case of inadequate response, phototherapy, systemic immunosuppressants and, more recently, dupilumab, should be added. Nevertheless, the treatment of moderate-to-severe atopic dermatitis remains challenging and novel, efficacious, safe and targeted treatments are urgently needed. In conclusion, although the last few years have seen important improvement in the understanding of the disease, future research in atopic dermatitis will continue exploring gene-environment interactions and how it affects pathophysiology, disease severity, and treatment outcomes.

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