Immunologic contact urticaria – the human touch

Myricetin alleviated immunologic contact urticaria and mast cell degranulation via the PI3K/Akt/NF-κB pathway

Immunologic contact urticaria (ICU) is characterized by the wheal and flare reaction from direct contact with a chemical or protein agent, which involves a type I hypersensitivity mediated by allergen-specific immunoglobulin E (sIgE). Myricetin (Myr), a bioactive flavonoid, exhibits antiinflammatory activities. Our results showed that treatment with Myr could alleviate ICU symptoms, including a decrease in the number of wheals and scratching, and inhibit ear swelling in the IgE/DNFB-induced mice. The serum level of IgE, histamine, interleukin (IL)-4, TNF-α, and MCP-1 were reduced in Myr-treated mice. Myr also attenuated mast cells (MCs) degranulation and H-PGDS, TSLP, IL-33, PI3K, Akt, and NF-κB mRNA levels in ICU model. The IgE-mediated anaphylaxis mouse models demonstrated anti-allergic effects of Myr. In vitro analysis showed that Myr reduced IgE-induced calcium (Ca²⁺ ) influx, suppressed degranulation, and chemokine release in LAD2 cells (human primary mast cells). Myr can significantly inhibited PLCγ1, Akt, NF-κB, and p38 phosphorylation. In conclusion, the study demonstrated that Myr alleviate ICU symptoms and inhibit mast cell activation via PI3K/Akt/NF-κB signal pathway.

Silencing ICAM-1 reduces the adhesion of vascular endothelial cells in mice with immunologic contact urticaria

OBJECTIVE

Immunologic contact urticaria (ICU) is an immediate response of wheal caused by various contactants in vulnerable individuals, with undefined pathogenesis.

METHODS

In the present study, we aim to explore the effects of intercellular cell adhesion molecule-1 (ICAM-1) gene silencing by RNA inference (RNAi) on vascular endothelial cells (VECs) adhesion molecule expression and cell-cell adhesion in ICU mice. Sixty BALB/c mice were selected, among which 48 mice were used for establishment of ICU models. VECs from normal and ICU mice were grouped into different groups. Expressions of ICAM-1, eosinophilic cationic protein (ECP), total immunologlobulin E (tIgE), L-selectin (CD62L), integrin, alpha L (CD11a) in tissues and cells were evaluate by RT-qPCR and western blotting. Cell proliferation was evaluated by MTT assay and EdU staining and cell adhesive function by cell-cell adhesion assay.

RESULTS

Compared with normal mice, ICU mice had increased expressions of ICAM-1, ECP, tIgE, CD62L, and CD11a.ICAM-1 gene silencing decreased expressions of ECP, tIgE, CD62L, and CD11a, enhanced cell proliferation, and more activity in cell adhesion.

CONCLUSION

These findings indicate that RNAi-mediated gene silencing of ICAM-1 may decrease VECs adhesion expression and reduce cell-cell adhesion in mice with ICU.

Effects of RNA interference-mediated E-selectin gene silencing on cell adhesion molecule expression and cell-cell adhesion in vascular endothelial cells in mice with immunologic contact urticaria

Contact urticaria is recognized as the wheal and flare reaction at a site from direct contact with a chemical or protein agent. Ongoing studies have proposed that gene silencing may have a promising future in finding optimal treatment of a variety of disease; hence, the aim of the study was to investigate the effect of RNA interference-mediated E-selectin ( SELE) gene silencing on cell adhesion molecule expression and on cell-cell adhesion in vascular endothelial cells (VECs) in a mouse model of immunologic contact urticaria (ICU). Following the successful establishment of mouse models of ICU induced by antidinitrophenol immunoglobulin E (IgE) combining 2,4-dinitrofluorobenzene challenge, enzyme-linked immunosorbent assay and immunohistochemistry were used to measure the levels of IgE, interleukin 4 (IL-4), interferon-γ (IFN-γ), and histamine as well as the positive expression rate of SELE, respectively. The siRNA- SELE vector was constructed and transfection efficiency was estimated prior to performing quantitative reverse-transcription polymerase chain reaction and Western blot assay to determine the relative expression of SELE, eosinophil cationic protein (ECP), intercellular adhesion molecule 1 (ICAM-1), L-selectin (CD62L), and the alpha chain of leukocyte function-associated antigen-1 (CD11a). Adhesion assay was then performed to assess the cell adhesion ability in VECs. Elevated levels of IgE, IL-4, IFN-γ, and histamine and increased positive expression rate of SELE were indicative of successful establishment of mouse models of ICU. Furthermore, the relative expression levels of SELE, ECP, ICAM-1, CD62L, and CD11a were highest in the OE- SELE group. Besides, cell adhesion ability of VECs was notably promoted. Collectively, the current study define the potential role of SELE silencing as an inhibitor to ICU development by inhibiting cell adhesion ability of VECs.

Proposed ICDRG Classification of the Clinical Presentation of Contact Allergy

The International Contact Dermatitis Research Group proposes a classification for the clinical presentation of contact allergy. The classification is based primarily on the mode of clinical presentation. The categories are direct exposure/contact dermatitis, mimicking or exacerbation of preexisting eczema, multifactorial dermatitis including allergic contact dermatitis, by proxy, mimicking angioedema, airborne contact dermatitis, photo-induced contact dermatitis, systemic contact dermatitis, noneczematous contact dermatitis, contact urticaria, protein contact dermatitis, respiratory/mucosal symptoms, oral contact dermatitis, erythroderma/exfoliative dermatitis, minor forms of presentation, and extracutaneous manifestations.

The definition, diagnostic testing, and management of chronic inducible urticarias - The EAACI/GA(2) LEN/EDF/UNEV consensus recommendations 2016 update and revision

These recommendations for the definition, diagnosis and management of chronic inducible urticaria (CIndU) extend, revise and update our previous consensus report on physical urticarias and cholinergic urticaria (Allergy, 2009). The aim of these recommendations is to improve the diagnosis and management of patients with CIndU. Our recommendations acknowledge the latest changes in our understanding of CIndU, and the available therapeutic options, as well as the development of novel diagnostic tools.