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1.
J Am Acad Dermatol ; 90(5): 953-962, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38215793

RESUMO

BACKGROUND: Distinguishing between allergic and nonallergic forms of Contact Dermatitis (CD) is challenging and requires investigations based on patch-testing. Early detection of allergy biomarkers in active CD lesions could refine and simplify the management of CD patients. OBJECTIVE: To characterize the molecular signatures of active CD lesions. METHODS: We studied the expression of 12 allergy biomarkers by qRT-PCR in active lesions of 38 CD patients. Allergic CD (ACD) was diagnosed based on patch test (PT) results and exposure assessment. Molecular signatures of active lesions, as well as positive PT reactions, were compared with those of reference chemical allergens and irritants. RESULTS: Nineteen of the 38 CD patients reacted positively upon patch-testing and exposure assessment confirmed ACD diagnosis for 17 of them. Gene profiling of active CD lesions revealed 2 distinct molecular patterns: patients harboring signatures similar to reference allergens (n = 23) or irritants (n = 15). Among the 23 patients with an "allergy signature," we found the 17 patients with confirmed ACD, while no culprit allergen was identified for the 6 other patients. Interestingly, the 15 patients without biomarker induction had negative PT, suggesting that they developed nonallergic CD reactions. CONCLUSION: Molecular signatures from active skin lesions may help to stratify CD patients and predict those suffering from ACD.


Assuntos
Dermatite Alérgica de Contato , Dermatite Irritante , Humanos , Irritantes , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/genética , Dermatite Alérgica de Contato/patologia , Alérgenos , Testes do Emplastro/métodos , Biomarcadores , Dermatite Irritante/diagnóstico
3.
Contact Dermatitis ; 90(1): 23-31, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37857578

RESUMO

BACKGROUND: Transcriptome analyses of vesicular hand eczema (VHE) indicated a large overlap with atopic dermatitis (AD). However, differentially expressed genes (DEGs) that differentiate VHE from AD are unknown. OBJECTIVE: To identify distinctive transcriptional features of VHE in comparison to AD. METHODS: We re-analysed RNA sequencing data of 10 lesional palmar VHE epidermal biopsies and performed DEG analyses. We adjusted the obtained DEG results of 57 lesional whole AD skin biopsies of the upper extremities or trunk to our criteria. Up- and down-regulated DEGs in both skin diseases, VHE-only, AD-only, and opposite regulated DEGs were identified. Enrichment analyses and Chi-squared tests were conducted to test for differences in gene set enrichment between both skin diseases. RESULTS: Comparing 3028 DEGs in VHE (1645 up; 1383 down) with 5391 DEGs in AD (3842 up; 1549 down), revealed 1516 shared DEGs (1179 up; 337 down) and 1512 DEGs unique to VHE (466 up, 1046 down). Interferon signalling and necroptosis were significantly more prominent in VHE compared to AD. Downregulated genes identified only in VHE (like DNASE1L2, KRT2, KRT9 and KRT25) indicate an aberrant epidermal differentiation. CONCLUSION: Our study indicates a common pathophysiology between VHE and AD, but also reveals transcriptional differences between VHE and AD.


Assuntos
Dermatite Alérgica de Contato , Dermatite Atópica , Eczema Disidrótico , Eczema , Humanos , Dermatite Atópica/genética , Dermatite Alérgica de Contato/patologia , Pele/patologia , Perfilação da Expressão Gênica , Eczema/genética , Desoxirribonuclease I
4.
Contact Dermatitis ; 90(1): 84-88, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37937664

RESUMO

BACKGROUND: Several methyl esters of sulphonic acids are listed in murine local lymph node assay (LLNA) databases, with dose-response data and EC3 values. However, some of these entries are questionable-in one case the chemical tested is not the chemical named in the databases and in others the EC3 value has been derived by extrapolation from data that do not meet the applicability criteria for the approved extrapolation method. OBJECTIVES: To consider how LLNA data came to be attributed to the wrong chemical and to address the inappropriate extrapolated EC3 values. METHODS: Dose-response data for methyl hexadec-3-enesulphonate (wrongly named as methyl hexadec-1-enesulphonate), two other methyl sulphonates and hexadec-1-ene-1,3-sultone are re-evaluated using the single dose probit extrapolation method (SDPEM). The different reaction chemistry profiles of methyl hexadec-3-enesulphonate and methyl hexadec-1-enesulphonate are discussed. RESULTS: Extrapolated EC3 values for hexadec-1-ene-1,3-sultone are the same by both methods but for the methyl sulphonates the differences are substantial. CONCLUSIONS: Current databases should be corrected and further analysed to identify other cases where EC3 values are likely to be unreliable due to inappropriate estimation by extrapolation.


Assuntos
Dermatite Alérgica de Contato , Animais , Camundongos , Humanos , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/patologia , Alérgenos , Ésteres , Linfonodos , Pele , Ensaio Local de Linfonodo
5.
Microsc Microanal ; 29(2): 762-776, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-37749732

RESUMO

Allergic contact dermatitis (ACD) is an occupation-dependent skin disease that afflicts humans with recurrent, non-specific episodes. Telocyte (TC) is a novel interstitial cell discovered in recent years and, together with fibroblasts, constitutes the predominant interstitial cell population in the skin. The purpose of this study was to investigate the morphodynamic changes of interstitial cells, especially TCs, in the skin during the development and treatment of ACD by histological and microscopic scientific methods. Hematoxylin-eosin staining, Masson staining, immunohistochemistry (IHC), immunofluorescence (IF), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to track morphodynamic changes in interstitial cells during the development and treatment in the ACD-involved skin induced by 2,4-dinitrochlorobenzene (DNCB). The results demonstrated that TCs were mainly present around dermal collagen fibers, perivascular (except dermal papillary vascular loop), and skin appendages, which expressed CD34+, Vimentin+, PDGFR-α+, and α-SMA-. The absence of TCs during ACD development and after ACD recovery causes dermal interstitial cell dysregulation. The special anatomical relationships between TCs, immune cells, and follicular stem cells were also revealed, suggesting their potential dermatitis-regulating function. In a nutshell, our results provide morphodynamic evidence for the process of ACD development and recovery and offer potential cytological ideas for ACD treatment.


Assuntos
Dermatite Alérgica de Contato , Células Intersticiais de Cajal , Telócitos , Humanos , Telócitos/ultraestrutura , Pele/patologia , Dermatite Alérgica de Contato/patologia , Imuno-Histoquímica
6.
J Allergy Clin Immunol ; 152(6): 1520-1540, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37562754

RESUMO

BACKGROUND: Elicitation of allergic contact dermatitis (ACD), an inflammatory type 4 hypersensitivity disease, induces skin infiltration by polyclonal effector CD8 αß T cells and precursors of tissue-resident memory T (TRM) cells. Because TRM have long-term potential to contribute to body-surface immunoprotection and immunopathology, their local regulation needs a fuller understanding. OBJECTIVE: We sought to investigate how TRM-cell maturation might be influenced by innate-like T cells pre-existing within many epithelia. METHODS: This study examined CD8+ TRM-cell maturation following hapten-induced ACD in wild-type mice and in strains harboring altered compartments of dendritic intraepidermal γδ T cells (DETCs), a prototypic tissue-intrinsic, innate-like T-cell compartment that reportedly regulates ACD, but by no elucidated mechanism. RESULTS: In addition to eliciting CD8 TRM, ACD induced DETC activation and an intimate coregulatory association of the 2 cell types. This depended on DETC sensing IFN-γ produced by CD8 cells and involved programmed death-ligand 1 (PD-L1). Thus, in mice lacking DETC or lacking IFN-γ receptor solely on γδ cells, ACD-elicited CD8 T cells showed enhanced proliferative and effector potentials and reduced motility, collectively associated with exaggerated ACD pathology. Comparable dysregulation was elicited by PD-L1 blockade in vitro, and IFN-γ-regulated PD-L1 expression was a trait of human skin-homing and intraepithelial γδ T cells. CONCLUSIONS: The size and quality of the tissue-infiltrating CD8 T-cell response during ACD can be profoundly regulated by local innate-like T cells responding to IFN-γ and involving PD-L1. Thus, interindividual and tissue-specific variations in tissue-intrinsic lymphocytes may influence responses to allergens and other challenges and may underpin inflammatory pathologies such as those repeatedly observed in γδ T-cell-deficient settings.


Assuntos
Dermatite Alérgica de Contato , Interferon gama , Animais , Humanos , Camundongos , Antígeno B7-H1 , Linfócitos T CD8-Positivos/patologia , Dermatite Alérgica de Contato/patologia , Pele/patologia
7.
Regul Toxicol Pharmacol ; 141: 105402, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37116738

RESUMO

The local lymph node assay (LLNA) has provided a large dataset against which performance of non-animal approaches for prediction of skin sensitisation potential and potency can be assessed. However, a recent comparison of LLNA results with human data has argued that LLNA specificity is low, with many human non-sensitisers, particularly hydrophobic chemicals, being false positives. It has been suggested that such putative false positives result from hydrophobic chemicals causing cytotoxicity, which induces irritancy, in turn driving non-specific lymphocyte proliferation. This paper finds that the apparent reduced specificity of the LLNA largely reflects differences in definitions of the boundaries between weak skin sensitisers and non-sensitisers. A small number of LLNA false positives may be due to lymphocyte proliferation without skin sensitisation, but most alleged 'false' positives are in fact very weak sensitisers predictable from structure-activity considerations. The evidence does not support the hypothesis for hydrophobicity-induced false positives. Moreover, the mechanistic basis is untenable. Sound LLNA data, appropriately interpreted, remain a good measure of sensitisation potency, applicable across a wide hydrophilicity-hydrophobicity range. The standard data interpretation protocol enables detection of very low levels of sensitisation, irrespective of regulatory significance, but there is scope to interpret the data to give focus on regulatory significance.


Assuntos
Dermatite Alérgica de Contato , Ensaio Local de Linfonodo , Humanos , Pele , Irritantes/química , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/patologia , Alérgenos/toxicidade , Linfonodos
8.
J Vis Exp ; (193)2023 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-37036234

RESUMO

Skin is the human body's first line of defense and one of the most exposed organs to environmental chemicals. Allergic contact dermatitis (ACD) is a common skin disease that manifests as a local rash, redness, and skin lesions. The occurrence and development of ACD are influenced by both genetic and environmental factors. Although many scholars have constructed a series of models of ACD in recent years, the experimental protocols of these models are all different, which makes it difficult for readers to establish them well. Therefore, a stable and efficient animal model is of great significance to further study the pathogenesis of atopic dermatitis. In this study, we detail a modeling method using 1-fluoro-2,4-dinitrobenzene (DNFB) to induce ACD-like symptoms in the ears of mice and describe several methods for assessing the severity of dermatitis during modeling. This experimental protocol has been successfully applied in some experiments and has a certain promotional role in the field of ACD research.


Assuntos
Dermatite Alérgica de Contato , Dermatite Atópica , Animais , Humanos , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/patologia , Pele/patologia , Modelos Animais de Doenças , Orelha/patologia
9.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 48(1): 1-14, 2023 Jan 28.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-36935172

RESUMO

OBJECTIVES: Ozone is widely applied to treat allergic skin diseases such as eczema, atopic dermatitis, and contact dermatitis. However, the specific mechanism remains unclear. This study aims to investigate the effects of ozonated oil on treating 2,4-dinitrochlorobenzene (DNCB)-induced allergic contact dermatitis (ACD) and the underling mechanisms. METHODS: Besides the blank control (Ctrl) group, all other mice were treated with DNCB to establish an ACD-like mouse model and were randomized into following groups: a model group, a basal oil group, an ozonated oil group, a FcεRI-overexpressed plasmid (FcεRI-OE) group, and a FcεRI empty plasmid (FcεRI-NC) group. The basal oil group and the ozonated oil group were treated with basal oil and ozonated oil, respectively. The FcεRI-OE group and the FcεRI-NC group were intradermally injected 25 µg FcεRI overexpression plasmid and 25 µg FcεRI empty plasmid when treating with ozonated oil, respectively. We recorded skin lesions daily and used reflectance confocal microscope (RCM) to evaluate thickness and inflammatory changes of skin lesions. Hematoxylin-eosin (HE) staining, real-time PCR, RNA-sequencing (RNA-seq), and immunohistochemistry were performed to detct and analyze the skin lesions. RESULTS: Ozonated oil significantly alleviated DNCB-induced ACD-like dermatitis and reduced the expressions of IFN-γ, IL-17A, IL-1ß, TNF-α, and other related inflammatory factors (all P<0.05). RNA-seq analysis revealed that ozonated oil significantly inhibited the activation of the DNCB-induced FcεRI/Syk signaling pathway, confirmed by real-time PCR and immunohistochemistry (all P<0.05). Compared with the ozonated oil group and the FcεRI-NC group, the mRNA expression levels of IFN-γ, IL-17A, IL-1ß, IL-6, TNF-α, and other inflammatory genes in the FcεRI-OE group were significantly increased (all P<0.05), and the mRNA and protein expression levels of FcεRI and Syk were significantly elevated in the FcεRI-OE group as well (all P<0.05). CONCLUSIONS: Ozonated oil significantly improves ACD-like dermatitis and alleviated DNCB-induced ACD-like dermatitis via inhibiting the FcεRI/Syk signaling pathway.


Assuntos
Dermatite Alérgica de Contato , Dermatite Atópica , Animais , Camundongos , Dinitroclorobenzeno/toxicidade , Dinitroclorobenzeno/metabolismo , Pele/metabolismo , Citocinas/metabolismo , Interleucina-17/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Dermatite Alérgica de Contato/tratamento farmacológico , Dermatite Alérgica de Contato/metabolismo , Dermatite Alérgica de Contato/patologia , Dermatite Atópica/induzido quimicamente , Transdução de Sinais , RNA Mensageiro/metabolismo , Camundongos Endogâmicos BALB C
10.
Int Immunopharmacol ; 117: 110003, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36931000

RESUMO

BACKGROUND: Allergic contact dermatitis (ACD) is one of the most common dermatoses, which has high disease burden and quality of life impairment. Anti-histamine is not effective in a part of the ACD patients. Thus, the discovery of novel antipruritic therapy is of highly demand. OBJECTIVE: In this study, we investigated the anti-pruritic effects of rosmarinic acid (RA) and explored the underlying mechanism. METHOD: SPF Balb/c mice were randomly divided into control group, ACD model group, RA group (1.0 mg/kg) and loratadine (LORA) group (1.5 mg/kg). Back epidermal thickness was recorded. H&E staining was used for pathological observation. Mast cell degranulation was assessed by toluidine blue staining. ELISA assay was employed to detect cytokines levels. Cortistatin-14 (CST-14) and Mas-related G protein-coupled receptor X2 (MRGPRX2) expression was detetcted by RT-PCR and western blot. Molecular docking assay was used to predict the affinity of RA and MRGPRX2. Surface plasmon resonance (SPR) assay was used to verify structure affinity of RA and MRGPRX2. RESULTS: RA treatment significantly decreased epidermal keratinization and inflammatory cell infiltration in ACD mouse model. Administration of RA significantly reduced secretion of histamine, IL-13, and mRNA expression of CST-14. Furthermore, RA treatment increased mRNA expression of MRGPRX2. In addition, Molecular docking results predict that RA has a good affinity with MRGPRX2. RA displayed a structure affinity (KD = 8.89 × 10-4) with MRGPRX2 by SPR. RA inhibited CST-14 and Compound 48/80 (C48/80)-induced mast cell activation via MRGPRX2-PLCγ1-PKC-NF-κB signaling pathway. CONCLUSION: RA exhibits anti-pruritic and anti-inflammatory effects in ACD mice by inhibiting MRGPRX2-PLCγ1-PKC-NF-κB signaling pathway. RA might emerge as a potential drug for the treatment of pruritus and skin inflammation in the setting of ACD.


Assuntos
Dermatite Alérgica de Contato , NF-kappa B , Animais , Camundongos , NF-kappa B/metabolismo , Mastócitos , Simulação de Acoplamento Molecular , Qualidade de Vida , Prurido/tratamento farmacológico , Dermatite Alérgica de Contato/patologia , Transdução de Sinais , Receptores Acoplados a Proteínas G/metabolismo , Inflamação/metabolismo , RNA Mensageiro/metabolismo , Degranulação Celular
11.
Regul Toxicol Pharmacol ; 138: 105333, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36608925

RESUMO

Meaningful and accurate reference data are crucial for the validation of New Approach Methodologies (NAMs) in toxicology. For skin sensitization, multiple reference datasets are available including human patch test data, guinea pig data and data from the mouse local lymph node assay (LLNA). When assessed against the LLNA, a reduced sensitivity has been reported for in vitro and in chemico assays for lipophilic chemicals with a LogP ≥3.5, resulting in reliability restrictions within the h-CLAT OECD test guideline. Here we address the question of whether LLNA data are an appropriate reference for chemicals in this physicochemical range. Analysis of LLNA vs human reference data indicates that the false-discovery rate of the LLNA is significantly higher for chemicals with LogP ≥3.5. We present a mechanistic hypothesis whereby irritation caused by testing lipophilic chemicals at high test doses leads to unspecific cell proliferation. The accompanying analysis indicates that for lipophilic chemicals with negative calls in in vitro and in chemico assays, resorting to the LLNA is not necessarily a better option. These results indicate that the validation of NAMs in this particular LogP range should be based on a more holistic evaluation of the reference data and not solely upon LLNA data.


Assuntos
Dermatite Alérgica de Contato , Ensaio Local de Linfonodo , Animais , Camundongos , Humanos , Cobaias , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/patologia , Reprodutibilidade dos Testes , Pele , Testes do Emplastro , Alérgenos/toxicidade , Linfonodos/patologia
12.
Adv Sci (Weinh) ; 10(7): e2204184, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36638280

RESUMO

Allergic contact dermatitis (ACD) and atopic dermatitis (AD) are the most common human skin disorders. Although corticosteroids have been widely used to treat ACD and AD, the side effects of corticosteroids encourage researchers to explore new immunoregulatory treatments. Here, an immunomodulatory approach based on lipid nanoparticles carrying α-helical configurational melittin (α-melittin-NP) is developed to overcome T cell-mediated inflammatory reactions in an oxazolone (OXA)-induced contact hypersensitivity mouse model and OXA-induced AD-like mouse model. Intradermal injection of low-dose α-melittin-NPs prevents the skin damage caused by melittin administration alone and efficiently targeted lymph nodes. Importantly, melittin and α-melittin-NPs restrain RelB activity in dendritic cells (DCs) and further suppresses dendritic cell activation and maturation in lymph nodes. Furthermore, low-dose α-melittin-NPs leads to relief of antigen recognition-induced effector T cell arrest in the dermis and inhibited allergen-specific T cell proliferation and activation. Significantly, this approach successfully controls Th1-type cytokine release in the ACD model and restricts Th2-type cytokine and IgE release in the AD-like model. Overall, intradermal delivery of low-dose α-melittin-NPs efficiently elicits immunosuppression against T cell-mediated immune reactions, providing a promising therapeutic strategy for treating skin disorders not restricted to the lesion region.


Assuntos
Dermatite Alérgica de Contato , Dermatite Atópica , Nanopartículas , Humanos , Animais , Camundongos , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/tratamento farmacológico , Linfócitos T , Meliteno/efeitos adversos , Dermatite Alérgica de Contato/tratamento farmacológico , Dermatite Alérgica de Contato/patologia , Citocinas
13.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-971365

RESUMO

OBJECTIVES@#Ozone is widely applied to treat allergic skin diseases such as eczema, atopic dermatitis, and contact dermatitis. However, the specific mechanism remains unclear. This study aims to investigate the effects of ozonated oil on treating 2,4-dinitrochlorobenzene (DNCB)-induced allergic contact dermatitis (ACD) and the underling mechanisms.@*METHODS@#Besides the blank control (Ctrl) group, all other mice were treated with DNCB to establish an ACD-like mouse model and were randomized into following groups: a model group, a basal oil group, an ozonated oil group, a FcεRI-overexpressed plasmid (FcεRI-OE) group, and a FcεRI empty plasmid (FcεRI-NC) group. The basal oil group and the ozonated oil group were treated with basal oil and ozonated oil, respectively. The FcεRI-OE group and the FcεRI-NC group were intradermally injected 25 µg FcεRI overexpression plasmid and 25 µg FcεRI empty plasmid when treating with ozonated oil, respectively. We recorded skin lesions daily and used reflectance confocal microscope (RCM) to evaluate thickness and inflammatory changes of skin lesions. Hematoxylin-eosin (HE) staining, real-time PCR, RNA-sequencing (RNA-seq), and immunohistochemistry were performed to detct and analyze the skin lesions.@*RESULTS@#Ozonated oil significantly alleviated DNCB-induced ACD-like dermatitis and reduced the expressions of IFN-γ, IL-17A, IL-1β, TNF-α, and other related inflammatory factors (all P<0.05). RNA-seq analysis revealed that ozonated oil significantly inhibited the activation of the DNCB-induced FcεRI/Syk signaling pathway, confirmed by real-time PCR and immunohistochemistry (all P<0.05). Compared with the ozonated oil group and the FcεRI-NC group, the mRNA expression levels of IFN-γ, IL-17A, IL-1β, IL-6, TNF-α, and other inflammatory genes in the FcεRI-OE group were significantly increased (all P<0.05), and the mRNA and protein expression levels of FcεRI and Syk were significantly elevated in the FcεRI-OE group as well (all P<0.05).@*CONCLUSIONS@#Ozonated oil significantly improves ACD-like dermatitis and alleviated DNCB-induced ACD-like dermatitis via inhibiting the FcεRI/Syk signaling pathway.


Assuntos
Animais , Camundongos , Dinitroclorobenzeno/metabolismo , Pele/metabolismo , Citocinas/metabolismo , Interleucina-17/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Dermatite Alérgica de Contato/patologia , Dermatite Atópica/induzido quimicamente , Transdução de Sinais , RNA Mensageiro/metabolismo , Camundongos Endogâmicos BALB C
14.
J Microbiol Biotechnol ; 32(12): 1506-1514, 2022 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-36377198

RESUMO

Allergic contact dermatitis (ACD) is an allergen-specific T-cell-mediated inflammatory response, albeit with unclear pathogenesis. Exosomes are nanoscale extracellular vesicles secreted by several cell types and widely distributed in various biological fluids. Exosomes affect the occurrence and development of ACD through immunoregulation among other ways. Nevertheless, the role of exosomes in ACD warrants further clarification. This review examines the progress of research into exosomes and their involvement in the pathogenesis, diagnosis, and treatment of ACD and provides ideas for exploring new diagnostic and treatment methods for this disease.


Assuntos
Dermatite Alérgica de Contato , Exossomos , Vesículas Extracelulares , Humanos , Exossomos/patologia , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/patologia , Alérgenos , Linfócitos T
15.
J Vis Exp ; (187)2022 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-36282686

RESUMO

Contact hypersensitivity (CHS) is an experimental model of allergic contact dermatitis (ACD) that can be studied in mice. This study aims to present an objective laboratory method that may help to study the CHS reaction in mice, which can be measured and quantified by various tests. To induce CHS, on day "0", mice were sensitized on a previously shaved spot by abdominal skin painting with the hapten 2,4,6-trinitrochlorobenzene (TNCB) in an acetone-ethanol mixture, whereas negative control mice were sham sensitized with vehicle alone-acetone-ethanol mixture. On day "4", the baseline ear thickness was measured with a micrometer prior to the elicitation of CHS (challenge) by painting both ears with diluted TNCB both in the test and control groups. After 24 h, the ear swelling was measured with a micrometer. CHS is an example of a T cell-mediated immune response that causes swelling in inflamed tissue, peaking 24 h after the skin challenge with the same hapten. An increase in ear edema correlated with augmented ear weight, myeloperoxidase (MPO) activity, pro-inflammatory cytokine concentration in the ear extracts, increased thickening of the edematous dermis in the histological examination, and ear vascular permeability. There was also an increase in the concentration of TNP-specific IgG1 antibodies in the sera of the test group when compared with the control mice. Additionally, CHS can be successfully transferred with the CHS-effector cells obtained from donors previously sensitized with TNCB. The CHS-effector cells were administered intravenously into naïve recipient mice, which were subsequently challenged with the same diluted hapten. Ear swelling was measured with a micrometer 24 h later.


Assuntos
Dermatite Alérgica de Contato , Peroxidase , Camundongos , Animais , Cloreto de Picrila , Modelos Animais de Doenças , Acetona , Camundongos Endogâmicos BALB C , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/patologia , Haptenos , Citocinas , Imunoglobulina G , Etanol
16.
Dermatologie (Heidelb) ; 73(11): 873-879, 2022 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-35925215

RESUMO

The nipple region is characterized by special anatomical conditions and from a dermatological perspective can be divided into breast skin, skin of the areola and the skin of the nipple. In a clinical context the nipples are often altered during lactation by mechanical alteration, changes in the environment with maceration by the milk flow and by microbial pathogens. In addition, there is a risk of developing puerperal mastitis. Outside of pregnancy and lactation, eczema diseases are occasionally found on the mammary skin, often with atopic disposition (atopic nipple eczema) or as irritant contact eczema ("joggers nipple"). More rarely, allergic contact eczema is observed from preservatives in topical preparations or metals (piercings). Also, in the context of a scabies infestation involvement of the nipples, especially in women, is regularly observed. Of great clinical importance are rare preinvasive lesions of breast cancer or Paget's disease of the mamilla of the extramammary type. Due to the special anatomical conditions, it is obvious that specific penetration conditions are also derived from the application of topical substances. Experimental studies on human skin ex vivo suggest that depending on the molecular weight and solubility of the drug as well as the vehicle system used, a significant increase in cutaneous bioavailability, especially on the nipple itself through the transpapillary diffusion pathway, may occur. This should be considered in particular in the topical application of drugs with known potential of dose-dependent side effects (e.g. glucocorticoids); however, there is still no clinical evidence for this.


Assuntos
Neoplasias da Mama , Dermatite Alérgica de Contato , Dermatite Atópica , Eczema , Gravidez , Feminino , Humanos , Mamilos/patologia , Irritantes , Eczema/tratamento farmacológico , Neoplasias da Mama/tratamento farmacológico , Dermatite Atópica/patologia , Dermatite Alérgica de Contato/patologia
17.
Regul Toxicol Pharmacol ; 134: 105244, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35932886

RESUMO

Considerable progress has been made in the design of New Approach Methodologies (NAMs) for the hazard identification of skin sensitising chemicals. However, effective risk assessment requires accurate measurement of sensitising potency, and this has proven more difficult to achieve without recourse to animal tests. One important requirement for the development and adoption of novel approaches for this purpose is the availability of reliable databases for determining the accuracy with which sensitising potency can be predicted. Some previous approaches have relied on comparisons with potency estimates based on either human or animal (local lymph node assay) data. In contrast, we here describe the development of a carefully curated Reference Chemical Potency List (RCPL) which is based on consideration of the best available human and animal data. The RCPL is comprised of 33 readily available chemicals that span a wide range of chemistry and sensitising potency, and contain examples of both direct and indirect (pre- and pro-) haptens. For each chemical a potency value (PV) was derived, and chemicals ranked according to PV without the use of potency categories. It is proposed that the RCPL provides an effective resource for assessment of the accuracy with which NAMs can measure skin sensitising potency.


Assuntos
Dermatite Alérgica de Contato , Alternativas aos Testes com Animais , Animais , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/patologia , Haptenos , Humanos , Ensaio Local de Linfonodo , Medição de Risco/métodos , Pele
18.
Food Chem Toxicol ; 166: 113201, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35671905

RESUMO

Citronellol, one of the most used fragrance compounds worldwide, is one ingredient of Fragrance Mix II used to assess skin allergy to fragrances in dermatitis patients. Pure citronellol is non-allergenic. Main issue is it autoxidizes when exposed to air becoming then allergenic. The increased skin sensitizing potency of air-exposed citronellol has been attributed to the hydroperoxides detected at high concentrations in the oxidation mixtures. It has been postulated that such hydroperoxides can give rise to specific antigens, although chemical mechanisms involved and the pathogenesis are far from being unraveled. Hydroperoxides are believed to react with skin proteins through mechanisms involving radical intermediates. Here, insights on the potential radicals involved in skin sensitization to citronellol hydroperoxides are given. The employed tool is a multispectroscopic approach based on (i) electron paramagnetic resonance and spin trapping, that confirmed the formation of oxygen- and carbon-radicals when exposing reconstructed human epidermis to concentrations of hydroperoxides close to those used for patch testing patients with air-oxidized citronellol; (ii) liquid chromatography-mass spectrometry, that proved the reaction with amino acids such as cysteine and histidine, known to be involved in radical processes and (iii) density functional theory calculations, that gave an overview on the preferential paths for radical degradation.


Assuntos
Dermatite Alérgica de Contato , Perfumes , Monoterpenos Acíclicos , Alérgenos , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/patologia , Radicais Livres , Humanos , Peróxido de Hidrogênio/metabolismo , Odorantes , Perfumes/química , Perfumes/toxicidade
19.
Regul Toxicol Pharmacol ; 130: 105128, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35104615

RESUMO

Potency determination of potential skin sensitizers in humans is essential for quantitative risk assessment and proper risk management. SENS-IS is an in vitro test based on a reconstructed human skin model, that was developed to predict the hazard and potency of potential skin sensitizers. The performance of the SENS-IS assay in potency prediction for 174 materials was evaluated for this work. The potency used as a benchmark was determined based on the weight of evidence approach, by collectively considering all well-established test data, including human, animal, in chemico, in vitro, and in silico data. Based on this weight of evidence approach, the dataset was composed of 5, 19, 34, 54, and 38 extreme, strong, moderate, weak, and very weak sensitizers, respectively, as well as 24 non-sensitizers. SENS-IS provided good prediction of the skin sensitization potency for 85% of this dataset, with precise and approximate prediction on 46% and 39% of the 174 materials, respectively. Our evaluation showed that SENS-IS provides a good approximation of the skin sensitization potency.


Assuntos
Dermatite Alérgica de Contato/patologia , Irritantes/toxicidade , Modelos Biológicos , Alternativas aos Testes com Animais , Animais , Relação Dose-Resposta a Droga , Humanos , Técnicas In Vitro , Reprodutibilidade dos Testes , Testes de Toxicidade
20.
Am J Dermatopathol ; 44(3): 205-206, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34991101

RESUMO

ABSTRACT: Lymphomatoid contact dermatitis (LCD) is a rare, benign pseudolymphoma with clinicopathologic features of both allergic contact dermatitis and cutaneous T-cell lymphoma (CTCL). In this article, we report a fascinating case of LCD secondary to chronic baby wet wipe use with clinical features of allergic contact dermatitis and histopathologic changes of mycosis fungoides, a subtype of CTCL. We argue that LCD should be added to the list of mimickers of mycosis fungoides, a subtype of CTCL.


Assuntos
Dermatite Alérgica de Contato/patologia , Doenças dos Genitais Femininos/patologia , Produtos Domésticos/efeitos adversos , Dermatite Alérgica de Contato/diagnóstico , Diagnóstico Diferencial , Feminino , Doenças dos Genitais Femininos/diagnóstico , Humanos , Pessoa de Meia-Idade , Micose Fungoide/diagnóstico
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