Psoriasiform Dermatitis Research Articles

Functional Connectivity Magnetic Resonance Imaging Reveals Rapid and Reversible Changes in the Brain Following Induction of Psoriasiform Dermatitis in Mice

Functional connectivity magnetic resonance imaging (fcMRI), a specific form of MRI imaging, quantitatively assesses connectivity between brain regions that share functional properties. Functional connectivity magnetic resonance imaging has already provided unique insights into changes in the brain in patients with conditions such as depression and pain and symptoms that have been reported by patients with psoriasis and are known to impact quality of life. To identify the central neurological impact of psoriasiform inflammation of the skin, we applied fcMRI analysis to mice that had been topically treated with the Toll-like receptor agonist, imiquimod (IMQ) to induce psoriasiform dermatitis. Brain insula regions, due to their suggested role in stress, were chosen as seed regions for fcMRI analysis. Mouse ear and head skin developed psoriasiform epidermal thickening (up to 4-fold, P < .05) and dermal inflammation after 4 days of topical treatment with IMQ. After fcMRI analysis, IMQ-treated mice showed significantly increased insula fc with wide areas throughout the brain, including, but not limited to, the somatosensory cortex, anterior cingulate cortex, and caudate putamen ( P < .005). This reflects a potential central neurological impact of IMQ-induced psoriasis-like skin inflammation. These data indicate that fcMRI may be valuable tool to quantitatively assess the neurological impact of skin inflammation in patients with psoriasis.

The non-neuronal and nonmuscular effects of botulinum toxin: an opportunity for a deadly molecule to treat disease in the skin and beyond.

There is growing evidence that botulinum neurotoxins (BoNTs) exhibit biological effects on various human cell types with a host of associated clinical implications. This review aims to provide an update on the non-neuronal and nonmuscular effects of botulinum toxin. We critically analysed recent reports on the structure and function of cellular signalling systems subserving biological effects of BoNTs. The BoNT receptors and intracellular targets are not unique for neurotransmission. They have been found in both neuronal and non-neuronal cells, but there are differences in how BoNT binds to, and acts on, neuronal vs. non-neuronal cells. The non-neuronal cells that express one or more BoNT/A-binding proteins, and/or cleavage target synaptosomal-associated protein 25, include: epidermal keratinocytes; mesenchymal stem cells from subcutaneous adipose; nasal mucosal cells; urothelial cells; intestinal, prostate and alveolar epithelial cells; breast cell lines; neutrophils; and macrophages. Serotype BoNT/A can also elicit specific biological effects in dermal fibroblasts, sebocytes and vascular endothelial cells. Nontraditional applications of BoNT have been reported for the treatment of the following dermatological conditions: hyperhidrosis, Hailey-Hailey disease, Darier disease, inversed psoriasis, aquagenic palmoplantar keratoderma, pachyonychia congenita, multiple eccrine hydrocystomas, eccrine angiomatous hamartoma, eccrine sweat gland naevi, congenital eccrine naevus, Raynaud phenomenon and cutaneous leiomyomas. Experimental studies have demonstrated the ability of BoNT/A to protect skin flaps, facilitate wound healing, decrease thickness of hypertrophic scars, produce an anti-ageing effect, improve a mouse model of psoriasiform dermatitis, and have also revealed extracutaneous effects of BoNT arising from its anti-inflammatory and anticancer properties. BoNTs have a much wider range of applications than originally understood, and the individual cellular responses to the cholinergic impacts of BoNTs could provide fertile ground for future studies.

TRPA1 Acts in a Protective Manner in Imiquimod-Induced Psoriasiform Dermatitis in Mice

This study revealed the modulatory role of transient receptor potential ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1) cation channels in the Aldara-induced (5% imiquimod) murine psoriasis model using selective antagonists and genetically altered animals. We have also developed a refined localized model to enable internal controls and reduce systemic effects. Skin pathology was quantified by measuring skin thickness, scaling, blood flow, and analyzing dermal cellular infiltrate, whereas nocifensive behaviors were also observed. Cytokine gene expression profiles were measured exvivo. Psoriasiform dermatitis was significantly enhanced in TRPA1 knockout mice and with TRPA1 antagonist (A967079) treatment. By comparison, symptoms were decreased when TRPV1 function was inhibited. Imiquimod induced Ca2+ influx in TRPA1-, but not in TRPV1-expressing cell lines. Immunohistochemical studies revealed that CD4+ T helper cells express TRPA1 but not TRPV1 ion channels in mice skin. Compared with the TRPV1 knockout animals, additional elimination of the TRPA1 channels in the TRPV1/TRPA1 double knockout mice did not modify the outcome of the imiquimod-induced reaction, further supporting the dominant role of TRPV1 in the process. Our results suggest that the protective effects in psoriasiform dermatitis can be mediated by the activation of neuronal and nonneuronal TRPA1 receptors.

Interleukin-21 receptor signalling is not critically required for imiquimod-induced psoriasiform dermatitis in mice.

Psoriasis is largely mediated by interleukin (IL)-23/T helper (Th) 17 axis, and IL-21 is a pleiotropic cytokine expressed by Th17 cells. Despite previously reported possible pathogenic roles of IL-21 in human psoriasis, we found that IL-21 receptor (IL-21R) signalling was not crucial for imiquimod-induced psoriatic inflammation, using IL-21R-/- mice. The severity of imiquimod-induced psoriatic manifestation and pro-inflammatory Th17 cytokine levels, IL-17A-producing γδ T cells and CD4+ T cells, and in vitro IL-17A production by γδ T cells after IL-23 stimulation was comparable between wild-type and IL-21R-/- mice. Collectively, IL-21R signalling was not critically involved in IMQ-induced psoriatic inflammation despite an increased IL-21 expression in the IMQ-treated mouse skin. Our data may represent the significant differences between human psoriasis and murine psoriasis model, and further studies using other models will be required to elucidate the role of IL-21 in psoriasis pathogenesis.

Ten-eleven Translocation-2 Regulates DNA Hydroxymethylation Status and Psoriasiform Dermatitis Progression in Mice.

Epigenetics plays an important role in the development and progression of many diseases. There is increasing evidence for the importance of epigenetic modifications in the progression of psoriasis. The aim of this study was to examine the role and potential mechanism of action of 5-hydroxymethylcytosine (5-hmC) and ten-eleven translocation-2 (TET2) in psoriasiform dermatitis in mice. Immunohistochemical staining was performed on psoriasis patients and healthy controls. Topical application of imiquimod cream to the dorsal skin of mice was used to induce psoriasiform dermatitis. In comparison with healthy controls, 5-hmC was more extensive and intense in the skin lesions from psoriasis patients. TET2 and 5-hmC were highly expressed in imiquimod-induced psoriasiform skin lesions. Importantly, knockdown of TET2 expression in mice attenuated the psoriasiform phenotype and the expression levels of proinflammatory cytokines (interleukin-17A and -17F and interferon-?) and the chemokine CXCL1 in the lesional skin of mice. This is the first demonstration of a critical role for TET2 in psoriasiform dermatitis in a mouse model, and indicates that 5-hmC may serve as a potential biomarker of psoriasis.

Ocrelizumab-induced psoriasiform dermatitis in a patient with multiple sclerosis

Multiple Sclerosis (MS) is a chronic autoimmune disease that presents with a wide variety of sensory and motor deficiencies. New medications targeting B cells have been approved to treat MS, but the side effect profile has not been widely explored. Herein, we report a case of drug-induced psoriasiform dermatitis following ocrelizumab treatment. Physicians should be cognizant of this possible side effect in patients receiving treatment for MS.

Decrease of galectin-3 in keratinocytes: A potential diagnostic marker and a critical contributor to the pathogenesis of psoriasis

Psoriasis-specific proteins dysregulated in keratinocytes and involved in the pathophysiological process of psoriasis remains elusive. We report here that epidermal galectin-3 expression is significantly downregulated in lesional skin, but not in non-lesional skin in psoriasis patients, nor in a group of diseases known as psoriasiform dermatitis clinically and histologically similar to psoriasis. The deficiency of epidermal galectin-3 is sufficient to promote development of psoriatic lesions, as evidenced by more severe skin inflammation in galectin-3 knockout (gal3−/−) mice, compared to wild-type mice, after imiquimod treatment, and in skin from gal3−/− mice grafted onto wildtype mice. The development of psoriatic-like lesions is attributable to 1) the spontaneously tuning up of psoriasis signatures in keratinocytes through JNK pathway; and 2) neutrophil accumulation caused by the enhanced leukocyte-recruiting capacity associated with overexpression of S100A7-9 and CXCL-1, 8 in keratinocytes with impaired galectin-3 expression. Psoriasis-like skin inflammation is significantly improved in gal-3−/− mice both by inhibition of neutrophils accumulation with a selective CXCR2 antagonist of SB225002, and by intracutaneous injection of recombinant galectin-3. Overall, these findings offer promising galectin-3-related diagnostic and therapeutic resolutions of psoriasis.

Skin-Specific CD301b+ Dermal Dendritic Cells Drive IL-17−Mediated Psoriasis-Like Immune Response in Mice

Conventional dendritic cells (cDCs) are composed of heterogeneous subsets commonly arising from dendritic cell (DC)-committed progenitors. A population of CD301b-expressing DCs has recently been identified in non-lymphoid barrier tissues such as skin. However, whether CD301b+ DCs in the skin represent an ontogenetically unique subpopulation of migratory cDCs has not been fully addressed. Here, we demonstrated that CD301b+ dermal DCs were distinct subpopulation of FMS-like tyrosine kinase 3 ligand (FLT3L)-dependent CD11b+ cDC2 lineage, which required an additional GM-CSF cue for the adequate development. Although the majority of lymphoid-resident cDC2 lacked CD301b expression, dermal migratory cDC2 contained a substantial fraction of CD301b+ subset. Similar to CD301b- population, CD301b+ dermal DC development was closely regulated by FLT3 signaling, suggesting their common origin from FLT3L-responsive cDC progenitors. However, FLT3L-driven cDC progenitor culture was not sufficient, but additional GM-CSF treatment was required to produce CD301b+ cDC2. Invivo development of CD301b+ cDC2 was significantly augmented by exogenous GM-CSF, while the repopulation of CD301b+ dermal cDC2 was abrogated by GM-CSF neutralization. Functionally, CD301b+ cDC2 was capable of producing a high level of IL-23, and the depletion of CD301b+ cDC2 effectively prevented IL-17-mediated psoriasiform dermatitis. Therefore, our findings highlight the differentiation program of a distinct CD301b+ dermal cDC2 subset in the skin and its involvement in psoriatic inflammation.

Chronic social stress Ameliorates psoriasiform dermatitis through upregulation of the Hypothalamic-Pituitary-Adrenal axis

Acute stress is a physiological response of an organism to adverse conditions, contributing to survival; however, persistence through time may lead to disease. Indeed, exacerbation of inflammatory conditions such as psoriasis has been reported to follow stressors in susceptible patients. Because chronic stress cannot ethically be elicited in patients under controlled laboratory conditions, we studied genetically modified mice that naturally develop psoriasiform dermatitis, and subjected them to an ethological chronic social contact stress paradigm. Although we found elevated pro-inflammatory neuropeptide production of substance P (SP), calcitonin-gene-related peptide (CGRP) and nerve-growth factor (NGF) mRNA in the dorsal root ganglia (DRG) as well as pro-inflammatory cytokines in response to the social stressor, stress paradoxically prevented the development of the skin lesions. This effect of stress could be reversed by the treatment with glucocorticoid (GC) receptor blockers, suggesting that it was mediated through the upregulation of corticosterone secretion. Extrapolating to humans, the worsening of disease in susceptible patients with psoriasis could be attributed to a defect in the Hypothalamic-Pituitary-Adrenal (HPA) axis with an impaired production of GC during situations of adversity, thus rendering them unable to counteract the pro-inflammatory effects of chronic stressors.

Protein engineering of the chemokine CCL20 prevents psoriasiform dermatitis in an IL-23–dependent murine model

Psoriasis is a chronic inflammatory skin disease characterized by the infiltration of T cell and other immune cells to the skin in response to injury or autoantigens. Conventional, as well as unconventional, γδ T cells are recruited to the dermis and epidermis by CCL20 and other chemokines. Together with its receptor CCR6, CCL20 plays a critical role in the development of psoriasiform dermatitis in mouse models. We screened a panel of CCL20 variants designed to form dimers stabilized by intermolecular disulfide bonds. A single-atom substitution yielded a CCL20 variant (CCL20 S64C) that acted as a partial agonist for the chemokine receptor CCR6. CCL20 S64C bound CCR6 and induced intracellular calcium release, consistent with G-protein activation, but exhibited minimal chemotactic activity. Instead, CCL20 S64C inhibited CCR6-mediated T cell migration with nominal impact on other chemokine receptor signaling. When given in an IL-23-dependent mouse model for psoriasis, CCL20 S64C prevented psoriatic inflammation and the up-regulation of IL-17A and IL-22. Our results validate CCR6 as a tractable therapeutic target for psoriasis and demonstrate the value of CCL20 S64C as a lead compound.

Resolvin D1 attenuates imiquimod-induced mice psoriasiform dermatitis through MAPKs and NF-κB pathways

BackgroundResolvin D1 (RvD1), a pro-resolution lipid mediator derived from docosahexaenoic acid (DHA), has been described to promote several kinds of inflammatory resolution. However, the effects and anti-inflammatory mechanisms of RvD1 on psoriasis have not been previously reported. ObjectiveThe present study aimed to determine the protective effects and the underlying mechanisms of RvD1 on imiquimod (IMQ)-induced psoriasiform dermatitis. MethodsMice were topically treated with IMQ to develop psoriasiform dermatitis on their shaved back, pretreated intraperitoneally (i.p.) with or without RvD1 or tert-butoxycarbonyl Met-Leu-Phe peptide (Boc), a lipoxin A4 (ALX) receptor antagonist. The severity was monitored and graded using a modified human scoring system, the Psoriasis Area and Severity Index (PASI), histopathology, and the signature cytokines of psoriasis (IL-23, IL-17, IL-22 and TNF-α). The mRNA and protein levels of inflammatory cytokines were quantified by quantitative real-time PCR (QRT-PCR) and ELISA. The expressions of signaling proteins MAPKs and NF-κB p65 were analyzed using western blotting. Electrophoretic mobility shift assay (EMSA) was used to check NF-κB p65 DNA binding activity. ResultsOur study showed that RvD1 alleviated IMQ-induced psoriasiform dermatitis and improved skin pathological changes. RvD1 markedly inhibited IMQ-induced activation of ERK1/2, p38, JNK (c-Jun N-terminal protein kinase, a subfamily of MAPKs), and NF-κB. Furthermore, pretreatment with Boc, would not exacerbate skin inflammation of IMQ-induced mice, but significantly reversed the beneficial effects of RvD1 on IMQ-induced psoriasiform inflammation. ConclusionRvD1 can obviously improve skin inflammation in IMQ-induced mice psoriasiform dermatitis. The protective mechanisms might be related to its selective reaction with lipoxin A4 receptor/Formyl-peptide receptor 2 (ALX/FPR2), by downregulating relevant cytokines of the IL-23/IL-17 axis expression, the inhibition of MAPKs and NF-κB signaling transduction pathways. Thus, these results show that RvD1 could be a possible candidate for psoriasis therapy.

T-helper immune phenotype may underlie 'paradoxical' tumour necrosis factor-α inhibitor therapy-related psoriasiform dermatitis.

Therapeutics targeting tumour necrosis factor (TNF)-α are effective for psoriasis; however, in patients treated for other disorders, psoriasis may worsen and psoriasiform dermatitis (PsoD) may arise. T helper (Th) cytokines in psoriasis upregulate keratin (K)17, which modulates TNF-α transduction, leading to vascular adhesion molecule upregulation and lymphocytic extravasation. We investigated Th phenotype and expression of K17, intercellular adhesion molecule (ICAM)-1 and vascular adhesion molecule (VCAM)-1 in psoriasis and anti-TNF-α-related PsoD. Skin biopsies from patients with psoriasis unresponsive to TNF-α inhibitor therapy (n=11), PsoD-related to TNF-α inhibition (n=9), untreated psoriasis (n=9) or atopic dermatitis (AD; n=9) were immunohistochemically analysed for Th1, Th2, Th17 and Th22. Expression of K17, ICAM-1 and VCAM-1 was also examined. Anti-TNF-α-unresponsive psoriasis and anti-TNF-α-related PsoD showed decreased Th1:Th2 raio and increased Th17:Th1 ratio compared with untreated psoriasis. Anti-TNF-α-unresponsive psoriasis had significantly fewer Th1 (4% vs. 12%) and more Th17 (51% vs. 20%) cells than untreated psoriasis. No difference in Th22 cells was identified. K17 was present in all cases of untreated psoriasis and anti-TNF-α-related PsoD, 91% of anti-TNF-α-unresponsive psoriasis, and only 22% of AD. VCAM-1 and ICAM-1 in anti-TNF-α-related PsoD was akin to untreated psoriasis, but decreased in anti-TNF-α-unresponsive psoriasis. These findings further the current understanding of the anti-TNF-α-related psoriasiform phenotype and support a rationale for therapeutic targeting of interleukin-17 and TNF-α in combination.

344 Opposing effect of TRPA1 and TRPV1 on imiquimod-induced psoriasiform dermatitis

344 Opposing effect of TRPA1 and TRPV1 on imiquimod-induced psoriasiform dermatitis

468 Methodological improvement of imiquimod-induced psoriasiform dermatitis model

468 Methodological improvement of imiquimod-induced psoriasiform dermatitis model

399 IL-36 receptor antagonistic antibodies inhibit inflammatory response in IL-23 model of psoriasiform dermatitis

399 IL-36 receptor antagonistic antibodies inhibit inflammatory response in IL-23 model of psoriasiform dermatitis

GM-CSF in murine psoriasiform dermatitis: Redundant and pathogenic roles uncovered by antibody-induced neutralization and genetic deficiency.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic, Th17-derived cytokine thought to critically contribute to the pathogenesis of diverse autoimmune diseases, including rheumatoid arthritis and psoriasis. Treatment with monoclonal antibodies that block GM-CSF activity is associated with favorable therapeutic effects in patients with rheumatoid arthritis. We evaluated the role of GM-CSF as a potential target for therapeutic interference in psoriasis using a combined pharmacologic and genetic approach and the mouse model of imiquimod-induced psoriasiform dermatitis (IMQPD). Neutralization of murine GM-CSF by an anti-GM-CSF antibody ameliorated IMQPD. In contrast, genetic deficiency in GM-CSF did not alter the course of IMQPD, suggesting the existence of mechanisms compensating for chronic, but not acute, absence of GM-CSF. Further investigation uncovered an alternative pathogenic pathway for IMQPD in the absence of GM-CSF characterized by an expanded plasmacytoid dendritic cell population and release of IFNα and IL-22. This pathway was not activated in wild-type mice during short-term anti-GM-CSF treatment. Our investigations support the potential value of GM-CSF as a therapeutic target in psoriatic disease. The discovery of an alternative pathogenic pathway for psoriasiform dermatitis in the permanent absence of GM-CSF, however, suggests the need for monitoring during therapeutic use of long-term GM-CSF blockade.

Lipoxin A4 and its analog suppress inflammation by modulating HMGB1 translocation and expression in psoriasis

Psoriasis is a chronic inflammatory skin disease that affects 2–3% of the global population, and there is still no known possibility of a cure. Lipoxin A4 (LXA4), an endogenous lipoxygenase-derived eicosanoid mediator, has potent dual pro-resolving and anti-inflammatory properties. BML-111 (5(S)-6(R)-7-trihydroxyheptanoic acid methyl ester), a lipoxin receptor agonist, has been previously confirmed to be equivalent to LXA4 in the anti-inflammatory processes. High mobility group box 1 (HMGB1) serves as an inflammatory cytokine when secreted extracellularly in psoriatic lesions and is involved in the development of psoriasis. Therefore, we investigated the effects of LXA4 and BML-111 on the HMGB1 signaling cascade and inflammation in lipopolysaccharide (LPS)-induced keratinocytes and imiquimod (IMQ)-induced psoriasiform dermatitis in mice. In the present study, we found that treatment with BML-111 attenuated the development of IMQ-induced psoriasiform dermatitis. Furthermore, treatment with BML-111 and LXA4 inhibited HMGB1 translocation from the nucleus to cytoplasm and downregulated the expression of toll-like receptor 4 (TLR4), receptor for advanced glycation end products (RAGE), p-ERK1/2, nuclear NF-κB p65, and proinflammatory cytokines in vivo and in vitro. Our findings indicate that LXA4 and its analog may be potential therapeutic candidates for psoriasis because of their ability to modulate the translocation and expression of HMGB1.

A rare case of sterol-C4-methyl oxidase deficiency in a young Italian male: Biochemical and molecular characterization

Inborn defects of cholesterol biosynthesis are metabolic disorders presenting with multi-organ and tissue anomalies. An autosomal recessive defect involving the demethylating enzyme C4-methyl sterol (SC4MOL) has been reported in only 4 patients so far. In infancy, all patients were affected by microcephaly, bilateral congenital cataracts, growth delay, psoriasiform dermatitis, immune dysfunction, and intellectual disability. Herein, we describe a new case of SC4MOL deficiency in which a 19-year-old Italian male was affected by bilateral congenital cataracts, growth delay and learning disabilities, behavioral disorders and small stature, but not microcephaly. Our patient had abundant scalp dandruff, without other skin manifestations. Analysis of the blood sterol profile showed accumulation of C4-monomethyl and C4-dimethyl sterols suggesting a deficiency of the SC4MOL enzyme. Sequencing of the MSMO1 gene (also known as the "SC4MOL" gene) confirmed mutations in each allele (c.731A>G, p.Y244C, which is already known, and c.605G>A, p.G202E, which is a novel variant). His father carried c.731A>G mutation, whereas his mother carried c.605G>A. Thus, the combination of multiple skills and methodologies, in particular, blood sterol profiling and genetic analysis, led to the diagnosis of a new case of a very rare defect of cholesterol biosynthesis. Consequently, we suggest that these two analyses should be performed as soon as possible in all undiagnosed patients affected by bilateral cataracts and developmental delay.

Generalized lichen nitidus and psoriasiform dermatitis associated with mogamulizumab and tremelimumab immunotherapy: A newly described immune-related adverse event

Generalized lichen nitidus and psoriasiform dermatitis associated with mogamulizumab and tremelimumab immunotherapy: A newly described immune-related adverse event

Biomarkers for psoriasis skin lesions.

Psoriasis is a common, chronic skin disease, whose diagnosis is based mainly on clinical features but, in some cases, can be difficult. As the exact diagnosis of psoriasis and the differential diagnosis with other diseases are crucial for the therapeutic choice, several studies investigated the relevance of some genes and proteins as potential specific skin biomarkers. Despite a large number of reports, none of them has been tested in large studies and thus achieved regulatory approval and clinical application. Authors give an overview on the skin biomarkers (BMs) in psoriasis, distinguishing inflammatory and epidermal biomarkers, highlighting the most distinctive skin psoriasis BMs, that can help physicians and pathologists to recognize psoriasis among "psoriasiform dermatitis".