RESUMO
Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Interleukin 31 (IL-31), a novel cytokine in AD, causes pruritus, typically characteristic of AD patients. The transient receptor potential vanilloid type 1 (TRPV1) is a cation channel activated by diverse noxious stimuli that has been studied in a variety of pruritic skin diseases. In this study, the AD animal model was generated by administering the hapten, trinitrochlorobenzene (TNCB), to Nc/Nga mice, and the degree of expression of the IL-31 receptor alpha (IL-31RA) and TRPV1 in the skin of these atopic models was evaluated. The Nc/Nga mice were divided into 3 groups: control, TNCB 2-weeks treated, and TNCB 8-weeks treated. After inducing AD, the skin lesions in each group were scored and compared, and the histology of the skin lesions and the IL-31RA and TRPV1 expression for each group were evaluated by analyzing immunohistochemistry. The results show a significant difference in the skin lesion scores between the groups. The immunohistochemistry evaluation highlighted the remarkable expression of IL-31RA and TRPV1 in the nerve fibers of the TNCB 8-weeks-treated group. We thus confirmed that the long-term application of TNCB induced chronic atopic-like dermatitis and that IL-31RA and TRPV1 were overexpressed in the peripheral nerve fibers in this AD model.
Assuntos
Dermatite Atópica , Animais , Camundongos , Dermatite Atópica/induzido quimicamente , Cloreto de Picrila , Pele , Prurido , Haptenos , Canais de Cátion TRPV/genéticaRESUMO
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 , EtanolRESUMO
We have previously reported that swellings caused by haptens, such as 2,4,6-trinitrochlorobenzene (TNCB), may be associated with the extracellular signal-regulated kinase (ERK)-induced proliferation pathway. However, the involvement of the Spred/Sprouty family as critical negative regulators of the Ras/Raf/ERK signaling pathway at disease sites is not well-established. Thus, in the present study, the effects of hapten-challenge on the expression levels of genes and proteins associated with the Spred/Sprouty family in the ear of mice were investigated. The activation of ERK and epidermal growth factor receptor (EGFR) tyrosine kinase was inhibited by their selective inhibitors, namely, U0126 and PD168393, respectively. Twenty-four hours after the final challenge by the haptens TNCB, 2,4-dinitrofluorobenzene, or oxazolone, ear thickness was augmented by challenge with all haptens and the gene expression levels of Spred1, Spred2, Sprouty1, and Sprouty2 in swelling induced by all haptens were significantly decreased. Furthermore, Spred2, Sprouty1, and Sprouty2 genes were decreased in the epidermis and dermis of the TNCB-challenged ear. In conclusion, it is possible that the mechanism of hapten-challenge-induced skin thickening involves not only the enhancement of cell proliferative functions via the activation of ERK by EGFR tyrosine kinase activation but also the decreases expression of Spred/Sprouty family members.
Assuntos
Dermatite de Contato , Proteínas Repressoras , Animais , Receptores ErbB/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Camundongos , Cloreto de Picrila , Proteínas Tirosina Quinases , Proteínas Repressoras/metabolismoRESUMO
The healing phase of contact hypersensitivity reactions is critically dependent on regulatory T cells (Tregs), but even the early inflammatory phase, that is, 6-24 hours after induction of a contact hypersensitivity reaction, is susceptible to Treg-mediated suppression. To investigate the underlying mechanisms, we injected Tregs before the challenge and analyzed the skin-infiltrating cells as early as 6 hours later. Early on, we found mainly neutrophils in the challenged skin, but only a few T cells. This influx of neutrophils was blocked by the injection of Tregs, indicating that they were able to prevent the first wave of leukocytes, which are responsible for starting an immune reaction. As an underlying mechanism, we identified that Tregs can tighten endothelial junctions by inducing intracellular cAMP, leading to protein kinase A-RhoAâdependent signaling. This eventually reorganizes endothelial junction proteins, such as Notch3, Nectin 2, Filamin B, and VE-cadherin, all of which contribute to the tightening of the endothelial barrier. In summary, Tregs prevent the leakage of proinflammatory cells from and into the tissue, which establishes a mechanism to downregulate immune reactions.
Assuntos
Dermatite Alérgica de Contato/imunologia , Endotélio Vascular/patologia , Neutrófilos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Comunicação Celular/imunologia , Quimiotaxia/imunologia , Dermatite Alérgica de Contato/patologia , Modelos Animais de Doenças , Endotélio Vascular/imunologia , Humanos , Camundongos , Cloreto de Picrila/administração & dosagem , Cloreto de Picrila/imunologia , Pele/irrigação sanguínea , Pele/imunologia , Pele/patologiaRESUMO
BACKGROUND: Abnormal immune responses, specifically excessive differentiation of Th2 cells, are associated with the development of atopic dermatitis (AD). Sophoricoside, the genistein-4'-ß-D-glucoside isolated from Styphnolobium japonicum, has previously demonstrated anti-inflammatory and immunosuppressive effects along with IL-3 and IL-5 inhibitory activities. Therefore, we speculated that sophoricoside could regulate AD by regulating abnormal immune responses. PURPOSE: To investigate the role of sophoricoside on AD-like allergic skin inflammation induced by ovalbumin (OVA) or 2,4,6-trinitrochlorobenzene (TNCB) in mouse models. METHODS: Sophoricoside was isolated from the 70% ethanol extract of S. japonicum dried mature seeds. After being submitted to a purification process, its purity was assessed by high-performance liquid chromatography (HPLC). The effects of sophoricoside were determined in vivo by OVA- and TNCB-induced AD-like allergic skin inflammation in mice. Skin tissues were subjected with hematoxylin-eosin (H&E), Giemsa and toluidine blue staining. In vitro CD4+ T cell differentiation was performed and the levels of serum immunoglobulins, cytokines, and genes related to CD4+ T cell differentiation were determined by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR. Cytokine bioassay, mixed lymphocytes reaction and cell viability assay were performed. RESULTS: Topical application of sophoricoside decreased the symptoms of AD-like allergic skin inflammation, including elevated hypertrophic scars with spongiotic epidermis, epidermal hyperplasia, hyperkeratosis, infiltration of immune, and mast cells, dermal thickness, amounts of immunoglobulins, and pro-inflammatory cytokines, and the mast cell population in the skin. Sophoricoside also decreased T cell antigen receptor (TCR)-mediated immune responses. In particular, sophoricoside suppressed the differentiation of naïve CD4+ T cells into Th cell subsets, including Th1, Th2, and Th17, by inhibiting the expression of their subset-specific master transcription factors, leading to suppression of the expression and production of these cell subset-specific cytokines. CONCLUSION: Sophoricoside can improve AD-like allergic skin diseases mainly by inhibiting pathogenic CD4+ T cell differentiation and immune responses.
Assuntos
Benzopiranos/uso terapêutico , Dermatite Atópica/tratamento farmacológico , Fabaceae/química , Animais , Citocinas/metabolismo , Dermatite Atópica/imunologia , Modelos Animais de Doenças , Feminino , Imunoglobulina E/sangue , Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/toxicidade , Cloreto de Picrila/toxicidade , Pele/efeitos dos fármacos , Pele/imunologia , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Linfócitos T Auxiliares-Indutores/imunologia , Células Th2/imunologiaAssuntos
Dermatite Atópica/tratamento farmacológico , Fármacos Dermatológicos/administração & dosagem , Receptor 3 Toll-Like/antagonistas & inibidores , Administração Cutânea , Animais , Dermatite Atópica/imunologia , Dermatite Atópica/patologia , Modelos Animais de Doenças , Humanos , Mediadores da Inflamação/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/imunologia , Queratinócitos/metabolismo , Camundongos , Cloreto de Picrila/administração & dosagem , Poli I-C/administração & dosagem , Poli I-C/imunologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Pele/citologia , Pele/efeitos dos fármacos , Pele/imunologia , Pele/patologia , Receptor 3 Toll-Like/metabolismoRESUMO
In the present study, we demonstrated that there is a direct relationship between scratching behaviors induced by itch and functional changes in the brain reward system. Using a conditional place preference test, the rewarding effect was clearly evoked by scratching under both acute and chronic itch stimuli. The induction of ΔFosB, a member of the Fos family of transcription factors, was observed in dopamine transporter (DAT)-positive dopamine neurons in the ventral tegmental area (VTA) of mice suffering from a chronic itch sensation. Based on a cellular analysis of scratching-activated neurons, these neurons highly expressed tyrosine hydroxylase (TH) and DAT genes in the VTA. Furthermore, in an in vivo microdialysis study, the levels of extracellular dopamine in the nucleus accumbens (NAcc) were significantly increased by transient scratching behaviors. To specifically suppress the mesolimbic dopaminergic pathway using pharmacogenetics, we used the TH-cre/hM4Di mice. Pharmacogenetic suppression of mesolimbic dopaminergic neurons significantly decreased scratching behaviors. Under the itch condition with scratching behaviors restricted by an Elizabethan collar, the induction of ΔFosB was found mostly in corticotropin-releasing hormone (CRH)-containing neurons of the hypothalamic paraventricular nucleus (PVN). These findings suggest that repetitive abnormal scratching behaviors under acute and chronic itch stimuli may activate mesolimbic dopamine neurons along with pleasant emotions, while the restriction of such scratching behaviors may initially induce the activation of PVN-CRH neurons associated with stress.
Assuntos
Prurido/fisiopatologia , Prurido/psicologia , Recompensa , Área Tegmentar Ventral/fisiopatologia , Doença Aguda , Animais , Comportamento Animal/fisiologia , Doença Crônica , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Expressão Gênica , Histamina/administração & dosagem , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Núcleo Accumbens/fisiopatologia , Testes Farmacogenômicos , Cloreto de Picrila/administração & dosagem , Prurido/genética , Tirosina 3-Mono-Oxigenase/genéticaRESUMO
BACKGROUND: Atopic dermatitis (AD) is a common chronic inflammatory skin disease. To understand AD, there have been many trials establishing AD animal models. Although various trials to establish AD animal models have been existed, even the mechanisms of AD in animal models are not enough clarified. OBJECTIVES: This study assessed AD characteristics induced in Nishiki-nezumi Cinnamon/Nagoya (Nc/Nga) mice following trinitrochlorobenzene (TNCB) treatment for different periods and house dust mite (HDM) treatment to compare each model's immunological patterns, especially with cytokine antibody array tool. METHODS: In this study, we exposed Nc/Nga mice to TNCB or HDM extract to induce AD. Nc/Nga mice were divided into 4 groups: control, TNCB 2 weeks-treated, TNCB 8 weeks-treated, and HDM-treated groups. After AD induction, all mice were evaluated by serum immunoglobulin E (IgE) concentration and serum cytokine antibody assays, scoring of skin lesions, scoring of scratching frequency, and histological analysis. RESULTS: The results showed significant differences between groups in serum IgE concentration, skin lesion scores, and scratching frequency. The analysis results for serum cytokine antibody arrays showed that in the TNCB 8 weeks- and HDM-treated groups, but not in the TNCB 2 weeks-treated group, expressions of genes related to the immune response were enriched. Among the histological results, the skin lesions in the HDM-treated group were most similar to those of AD. CONCLUSIONS: We confirmed that immunological pattern of AD mice was markedly different between HDM and TNCB treated groups. In addition, the immunological pattern was quietly different dependent on TNCB treated duration.
Assuntos
Citocinas/análise , Dermatite Atópica/imunologia , Cloreto de Picrila/efeitos adversos , Pyroglyphidae/fisiologia , Animais , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/parasitologia , Modelos Animais de Doenças , Feminino , Camundongos , Fatores de TempoRESUMO
Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by pruritic and eczematous skin lesions. The skin of AD patients is generally in a dried condition. Therefore, it is important for AD patients to manage skin moisturization. In this study, we examined the effects of orally administered fermented barley extract P (FBEP), which is prepared from a supernatant of barley shochu distillery by-product, on stratum corneum (SC) hydration and transepidermal water loss (TEWL) in AD-like lesions induced in hairless mice using 2,4,6-trinitrochlorobenzene. Oral administration of FBEP increased SC hydration and decreased TEWL in the dorsal skin of this mouse model. Further fractionation of FBEP showed that a pyroglutamyl pentapeptide, pEQPFP comprising all -L-form amino acids, is responsible for these activities. These results suggested that this pyroglutamyl pentapeptide may serve as a modality for the treatment of AD.
Assuntos
Misturas Complexas/farmacologia , Dermatite Atópica/tratamento farmacológico , Epiderme/efeitos dos fármacos , Hordeum/química , Hipodermóclise/métodos , Oligopeptídeos/farmacologia , Ácido Pirrolidonocarboxílico/análogos & derivados , Animais , Misturas Complexas/isolamento & purificação , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/patologia , Modelos Animais de Doenças , Epiderme/patologia , Fermentação , Masculino , Camundongos , Camundongos Pelados , Oligopeptídeos/isolamento & purificação , Cloreto de Picrila/administração & dosagem , Ácido Pirrolidonocarboxílico/isolamento & purificação , Ácido Pirrolidonocarboxílico/farmacologia , Resultado do TratamentoRESUMO
BACKGROUND: Langerhans cells (LCs) polarize the immune milieu towards a T helper type (Th) 1 or Th2 immune response. We investigated the effects of selected tetracyclines on Th cells development mediated by LCs, and their implications for the treatment of atopic dermatitis (AD). METHODS: Mice were primed with ovalbumin (OVA) peptide-pulsed LCs, which had been treated with each antibiotic, via the hind footpad. After 5 days, the Th1/Th2 cytokine response in the popliteal lymph nodes was investigated by enzyme-linked immunosorbent assay. The expression of cell surface molecules on LCs was investigated using reverse transcriptase polymerase chain reaction. The therapeutic effects of a selected antibiotic on AD-like skin lesions of NC/Nga mice were assessed in terms of the skin severity score, histological changes in the lesioned skin, the serum level of total IgE, and expression of Th1/Th2 cytokines in lymph nodes and skin lesions. RESULTS: Antibiotic-treated, OVA peptide-pulsed LCs inhibited development of Th2 cells but not Th1 cells. This was accompanied by suppression of T-cell immunoglobulin and mucin domain-containing protein (TIM)-4 expression in LCs. Doxycycline had the greatest activity against Staphylococcus aureus strains isolated from skin lesions of patients with AD, and a strong inhibitory effect on Th2 cell development. Doxycycline suppressed the increase in the skin severity score during the acute phase in NC/Nga mice similar to betamethasone. This suppressive effect was associated with a decrease in the serum IgE level and production of Th2 cytokines in auricular lymph node cells and skin lesions. CONCLUSION: Topical application of doxycycline to AD lesions would act on both superficial S. aureus colonization and epidermal LCs, thus possibly inhibiting the development of Th2 cells in vivo, with benefits for control of acute inflammation in AD.
Assuntos
Antialérgicos/uso terapêutico , Antibacterianos/uso terapêutico , Dermatite Atópica/tratamento farmacológico , Células de Langerhans/efeitos dos fármacos , Tetraciclinas/uso terapêutico , Células Th2/efeitos dos fármacos , Administração Tópica , Alérgenos , Animais , Antialérgicos/farmacologia , Antibacterianos/farmacologia , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/imunologia , Dermatite Atópica/patologia , Imunoglobulina E/sangue , Células de Langerhans/imunologia , Linfonodos/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Ovalbumina , Cloreto de Picrila , Pele/efeitos dos fármacos , Pele/patologia , Staphylococcus aureus/efeitos dos fármacos , Tetraciclinas/farmacologia , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th2/imunologiaRESUMO
PURPOSE: Reactive oxygen and nitrogen species (ROS/RNS) production and the NF-κB activation are critically involved in inflammatory responses, but knowledge about the temporal dynamics during acute and chronic inflammation is limited. Here, we present a comparative longitudinal in vivo study of both parameters in an experimental model of acute and chronic T cell-driven delayed-type hypersensitivity reaction (DTHR) using noninvasive optical imaging. PROCEDURES: Trinitrochlorobenzene (TNCB)-sensitized NF-κB-luciferase-reporter and wild-type mice were TNCB challenged on the right ear to elicit acute DTHR and then repetitively challenged (up to five times) to induce chronic DTHR. Mice were treated with the ROS-scavenging and NF-κB inhibiting molecule N-acetylcysteine (NAC) or underwent sham treatment. ROS/RNS production was noninvasively analyzed in vivo using the ROS-/RNS-sensitive chemiluminescent probe L-012, and NF-κB activation was measured using NF-κB-luciferase-reporter mice. H&E staining, CD3 and myeloperoxidase (MPO) immunohistochemistry (IHC), and quantitative PCR (qPCR) analyses were employed to investigate immune cell infiltration and expression of NF-κB- and ROS-/RNS-driven genes. RESULTS: In acute DTHR, we found strongly elevated ROS/RNS production and NF-κB activation 12 h after the 1st TNCB ear challenge, peaking at 24 h after the challenge. In chronic DTHR, ROS production peaked as early as 4 h after the 5th TNCB challenge, whereas NF-κB activity peaked after 12 h. The increase in ROS/RNS production in acute DTHR was higher than the increase in NF-κB activity but the relationship was inverse in chronic DTHR. Treatment with the ROS scavenger NAC had differential effects on ROS/RNS production and NF-κB activation during acute and chronic DTHR. Ex vivo cross-validation by histopathology and qPCR analysis correlated closely with the in vivo imaging results. CONCLUSIONS: Noninvasive in vivo imaging is capable of assessing the temporal dynamics of ROS/RNS production and NF-κB activation during progression from acute to chronic DTHR and enables monitoring of anti-inflammatory treatment responses.
Assuntos
Acetilcisteína/farmacologia , Inflamação/imunologia , Inflamação/patologia , NF-kappa B/imunologia , Imagem Óptica/métodos , Espécies Reativas de Nitrogênio/imunologia , Espécies Reativas de Oxigênio/imunologia , Linfócitos T/imunologia , Animais , Modelos Animais de Doenças , Feminino , Sequestradores de Radicais Livres/farmacologia , Inflamação/diagnóstico por imagem , Inflamação/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Cloreto de Picrila/farmacologia , Transdução de Sinais , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismoRESUMO
We recently reported that swelling resulting from 2,4,6-trinitrochlorobenzene (TNCB) challenge might be associated with recruitment of neutrophils. However, it is not known whether neutrophil recruitment is affected by scratching at inflamed sites or not. Therefore, the effects of an Elizabethan collar on the TNCB-induced upregulation of ELR-positive chemokines (CXCL1, CXCL2, and CXCL5) and neutrophil recruitment were investigated. Mice were sensitized by the application of TNCB on abdominal skin. Then, the mice were challenged three times with TNCB to auricle of the ear. To prevent scratching at inflamed sites, an Elizabethan collar was placed on the mice from just before the first challenge until the end of the experiment. The effects of the Elizabethan collar on the TNCB-induced upregulation of CXCLs chemokines and recruitment of neutrophil were investigated. The increase of ear swelling by TNCB challenge was inhibited by the Elizabethan collar. TNCB-challenge-induced upregulation of TNF-α, IL-1ß, IL-6, ELR+ chemokines, MPO, and ELA2 was also attenuated by the Elizabethan collar. The gene expression of CXCL1, CXCL2, and CXCL5 human homolog IL-8 was enhanced by TNF-α and IL-1ß in human dermal fibroblasts and epidermal keratinocytes. We here suggest that scratching the site of inflammation leads to neutrophil accumulation mediated by TNF-α and IL-1ß/ELR+ chemokines in TNCB-challenge-induced contact dermatitis in mice.
Assuntos
Dermatite Alérgica de Contato/patologia , Infiltração de Neutrófilos , Pele/lesões , Animais , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-1beta/metabolismo , Interleucina-1beta/farmacologia , Camundongos , Cloreto de Picrila , Prurido , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Allergic disease is one of the most important and common health problems worldwide. We have previously demonstrated that a fig leaf-derived lactic acid bacterium Lactobacillus (Lb.) paracasei IJH-SONE68 produces a novel exopolysaccharide (EPS). Furthermore, we have shown that the EPS inhibits the catalytic activity of hyaluronidase (EC 3.2.1.36) promoting inflammatory reactions. To evaluate the anti-allergy and anti-inflammatory effects of the EPS, in the present study, we employed the picryl-chloride-induced delayed-type (type IV) allergy model mice, which is used to evaluate the contact dermatitis. Oral administration of the EPS was observed to reduce the ear swelling in the model mice. We also observed that the overexpression of ear interleukin-4 (T helper (Th) 2 cytokine) mRNA and the increase in serum immunoglobulin E (IgE) are repressed. However, the expression of interferon-γ (Th1 cytokine) was not accelerated in all of the allergen-challenged model mice. The improvement may be responsible for the Th2 downregulation rather than the Th1 upregulation. In addition, the symptom of immediate-type (type I) allergy model mice was improved by oral administration of the IJH-SONE68 cell (data not shown). We can conclude that the IJH-SONE68-derived EPS is useful to improve the type I and IV allergies including atopic dermatitis.
Assuntos
Antialérgicos/farmacologia , Anti-Inflamatórios/farmacologia , Dermatite de Contato/prevenção & controle , Fármacos Dermatológicos/farmacologia , Lacticaseibacillus paracasei/química , Polissacarídeos Bacterianos/farmacologia , Administração Oral , Alérgenos/imunologia , Alérgenos/metabolismo , Animais , Antialérgicos/isolamento & purificação , Anti-Inflamatórios/isolamento & purificação , Dermatite de Contato/etiologia , Dermatite de Contato/imunologia , Dermatite de Contato/patologia , Fármacos Dermatológicos/isolamento & purificação , Modelos Animais de Doenças , Orelha , Expressão Gênica/efeitos dos fármacos , Hialuronoglucosaminidase/antagonistas & inibidores , Hialuronoglucosaminidase/imunologia , Hialuronoglucosaminidase/metabolismo , Imunoglobulina E/sangue , Imunoglobulina E/genética , Interferon gama/genética , Interferon gama/imunologia , Interleucina-4/genética , Interleucina-4/imunologia , Lacticaseibacillus paracasei/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Cloreto de Picrila/administração & dosagem , Polissacarídeos Bacterianos/isolamento & purificação , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th2/efeitos dos fármacos , Células Th2/imunologiaRESUMO
Cysteine-type cathepsins such as cathepsin B are involved in various steps of inflammatory processes such as antigen processing and angiogenesis. Here, we uncovered the role of cysteine-type cathepsins in the effector phase of T cell-driven cutaneous delayed-type hypersensitivity reactions (DTHR) and the implication of this role on therapeutic cathepsin B-specific inhibition. Methods: Wild-type, cathepsin B-deficient (Ctsb-/-) and cathepsin Z-deficient (Ctsz-/-) mice were sensitized with 2,4,6-trinitrochlorobenzene (TNCB) on the abdomen and challenged with TNCB on the right ear to induce acute and chronic cutaneous DTHR. The severity of cutaneous DTHR was assessed by evaluating ear swelling responses and histopathology. We performed fluorescence microscopy on tissue from inflamed ears and lymph nodes of wild-type mice, as well as on biopsies from psoriasis patients, focusing on cathepsin B expression by T cells, B cells, macrophages, dendritic cells and NK cells. Cathepsin activity was determined noninvasively by optical imaging employing protease-activated substrate-like probes. Cathepsin expression and activity were validated ex vivo by covalent active site labeling of proteases and Western blotting. Results: Noninvasive in vivo optical imaging revealed strong cysteine-type cathepsin activity in inflamed ears and draining lymph nodes in acute and chronic cutaneous DTHR. In inflamed ears and draining lymph nodes, cathepsin B was expressed by neutrophils, dendritic cells, macrophages, B, T and natural killer (NK) cells. Similar expression patterns were found in psoriatic plaques of patients. The biochemical methods confirmed active cathepsin B in tissues of mice with cutaneous DTHR. Topically applied cathepsin B inhibitors significantly reduced ear swelling in acute but not chronic DTHR. Compared with wild-type mice, Ctsb-/- mice exhibited an enhanced ear swelling response during acute DTHR despite a lack of cathepsin B expression. Cathepsin Z, a protease closely related to cathepsin B, revealed compensatory expression in inflamed ears of Ctsb-/- mice, while cathepsin B expression was reciprocally elevated in Ctsz-/- mice. Conclusion: Cathepsin B is actively involved in the effector phase of acute cutaneous DTHR. Thus, topically applied cathepsin B inhibitors might effectively limit DTHR such as contact dermatitis or psoriasis. However, the cathepsin B and Z knockout mouse experiments suggested a complementary role for these two cysteine-type proteases.
Assuntos
Catepsinas/metabolismo , Cisteína/metabolismo , Hipersensibilidade Tardia/enzimologia , Pele/patologia , Doença Aguda , Animais , Domínio Catalítico , Catepsinas/antagonistas & inibidores , Doença Crônica , Feminino , Humanos , Inflamação/patologia , Camundongos Endogâmicos C57BL , Imagem Óptica , Cloreto de Picrila , Inibidores de Proteases/farmacologiaRESUMO
Platelets have diverse roles in immune processes in addition to their key functions in haemostasis and thrombosis. Some studies imply that platelets may be possibly related to the immune tolerance induction. However, the role of platelets in the development of immune tolerance is not fully understood. The purpose of this study was to investigate the role of platelets in the development of regulatory mechanisms responsible for cutaneous inflammation using a mouse model of low zone tolerance (LZT). Mice were treated with 2,4,6-trinitro-1-chlorobenzene (TNCB) 8 times every other day for tolerance induction with administration of anti-platelet antibody or control antibody during the tolerance induction phase every 3 days. After the treatment for the tolerance induction, mice were sensitized and then challenged with TNCB. The contact hypersensitivity (CHS) was significantly decreased at 24 hours after challenge in the mice with LZT than in those without LZT. Platelet depletion via administration of anti-platelet antibody reversed the inhibition of CHS and reduced the frequency of Foxp3+ Tregs in the inflamed skin and draining lymph nodes in mice with LZT. In addition, repeated low-dose skin exposure resulted in elevated plasma levels of transforming growth factor (TGF)-ß1. Interestingly, platelet depletion reduced plasma TGF-ß1 levels of mice with LZT. Furthermore, the CHS response was reduced by administration of recombinant TGF-ß1 during platelet depletion in mice with LZT. Administration of anti-TGF-ß antibody reversed the inhibition of the CHS responses. These results suggest that platelets are involved in the induction of immune tolerance via the release of TGF-ß1.
Assuntos
Plaquetas/imunologia , Tolerância Imunológica , Fator de Crescimento Transformador beta1/fisiologia , Animais , Plaquetas/efeitos dos fármacos , Dermatite de Contato/sangue , Dermatite de Contato/tratamento farmacológico , Ensaio de Imunoadsorção Enzimática , Fatores de Transcrição Forkhead/metabolismo , Sistema Imunitário , Leucócitos/efeitos dos fármacos , Linfonodos/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Cloreto de Picrila/farmacologia , Proteínas Recombinantes/metabolismo , Fator de Crescimento Transformador beta1/genéticaAssuntos
Dermatite Atópica/tratamento farmacológico , Inflamação/tratamento farmacológico , Oligodesoxirribonucleotídeos/uso terapêutico , Vaselina/uso terapêutico , Fator de Transcrição STAT6/genética , Pele/patologia , Células Th2/imunologia , Animais , Dermatite Atópica/induzido quimicamente , Modelos Animais de Doenças , Composição de Medicamentos , Humanos , Líquidos Iônicos , Camundongos , Pomadas , Oligodesoxirribonucleotídeos/genética , Cloreto de PicrilaRESUMO
Effects of selenium supplementation on atopic dermatitis (AD) were investigated by administering seleno-L-methionine (SeMet) using a mouse model of AD caused by repeated application of 2,4,6-trinitrochlorobenzene (TNCB). BALB/c mice were sensitized with TNCB to the abdomen on day -7; then, TNCB was applied repeatedly to each ear three times a week from days 0 to 23. SeMet was orally administered to the mice from days 0 to 23. The efficacy of SeMet on AD was assessed by measuring ear thickness, histologic evaluation, serum total immunoglobulin (Ig) E levels, and expression of interleukin (IL)-4 in the ear and superficial parotid lymph node. Ear thickness was remarkably increased by repeated application of TNCB, and SeMet significantly suppressed ear thickness in BALB/c mice. SeMet inhibited epidermal hyperplasia and dense infiltration of inflammatory cells. The number of TNCB-induced mast cells was significantly decreased by SeMet. Serum total IgE levels that increased by the repeated application of TNCB were significantly suppressed by SeMet. Repeated application of TNCB induced expression of IL-4, a T-helper (Th) 2 cytokine, in the ear and superficial parotid lymph node of BALB/c mice and its expression was significantly inhibited by SeMet. These results demonstrated that SeMet supplementation suppresses AD-like skin lesions in BALB/c mice and inhibits the expression of total IgE and IL-4.
Assuntos
Antialérgicos/uso terapêutico , Dermatite Atópica/tratamento farmacológico , Imunoglobulina E/sangue , Interleucina-4/imunologia , Selenometionina/uso terapêutico , Animais , Antialérgicos/farmacologia , Doença Crônica , Dermatite Atópica/sangue , Dermatite Atópica/imunologia , Feminino , Interleucina-4/genética , Fígado/metabolismo , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Mastócitos/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Cloreto de Picrila , Selenometionina/farmacologiaRESUMO
BACKGROUND: Genetic background influences allergic immune responses to environmental stimuli. Non-obese diabetic (NOD) mice are highly susceptible to environmental stimuli. Little is known about the interaction of autoimmune genetic factors with innate immunity in allergies, especially skin hypersensitivity. OBJECTIVES: To study the interplay of innate immunity and autoimmune genetic factors in contact hypersensitivity (CHS) by using various innate immunity-deficient NOD mice. METHODS: Toll-like receptor (TLR) 2-deficient, TLR9-deficient and MyD88-deficient NOD mice were used to investigate CHS. The cellular mechanism was determined by flow cytometry in vitro and adoptive cell transfer in vivo. To investigate the role of MyD88 in dendritic cells (DCs) in CHS, we also used CD11cMyD88+ MyD88-/- NOD mice, in which MyD88 is expressed only in CD11c+ cells. RESULTS: We found that innate immunity negatively regulates CHS, as innate immunity-deficient NOD mice developed exacerbated CHS accompanied by increased numbers of skin-migrating CD11c+ DCs expressing higher levels of major histocompatibility complex II and CD80. Moreover, MyD88-/- NOD mice had increased numbers of CD11c+ CD207- CD103+ DCs and activated T effector cells in the skin-draining lymph nodes. Strikingly, re-expression of MyD88 in CD11c+ DCs (CD11cMyD88+ MyD88-/- NOD mice) restored hyper-CHS to a normal level in MyD88-/- NOD mice. CONCLUSION: Our results suggest that the autoimmune-prone NOD genetic background aggravates CHS regulated by innate immunity, through DCs and T effector cells.
Assuntos
Dermatite de Contato/genética , Imunidade Inata/genética , Transferência Adotiva , Animais , Antígeno B7-1/metabolismo , Movimento Celular , Citocinas/imunologia , Citocinas/metabolismo , Células Dendríticas/citologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Dermatite de Contato/etiologia , Dermatite de Contato/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Imunidade Inata/imunologia , Linfonodos/citologia , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/imunologia , Cloreto de Picrila/efeitos adversos , RNA Mensageiro/metabolismo , Pele/citologia , Pele/imunologia , Pele/metabolismo , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/imunologia , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/imunologiaRESUMO
Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by intense pruritus and eczematous lesion. In this study, topically applied substance P (SP) significantly alleviated AD-like clinical symptoms in 2, 4, 6-trinitrochlorobenzene (TNCB)-induced dermatitis in NC/Nga mice. This effect was nullified by pretreatment of the neurokinin-1 receptor (NK-1R) antagonist CP99994. SP treatment significantly reduced the infiltration of mast cells and CD3-positive T cells as well as inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and thymic stromal lymphopoietin (TSLP), in AD-like skin lesions and decreased the levels of IgE and thymus and activation-regulated chemokine in serum. This SP-induced alleviation of allergic inflammatory responses was also confirmed as reduced activation in the axillary lymph nodes (aLN) and spleen, suggesting the systemic effect of SP on immune responses in TNCB-induced NC/Nga mice. Furthermore, SP-mediated TSLP reduction was confirmed in human keratinocyte culture under pro-inflammatory TNF-α stimulation. Taken together, these results suggest that topically administered SP may have potential as a medication for atopic dermatitis.
Assuntos
Degranulação Celular/efeitos dos fármacos , Dermatite Atópica/tratamento farmacológico , Mastócitos/fisiologia , Neurotransmissores/uso terapêutico , Substância P/uso terapêutico , Administração Cutânea , Animais , Complexo CD3/metabolismo , Células Cultivadas , Quimiocina CCL17/sangue , Citocinas/metabolismo , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/imunologia , Dermatite Atópica/patologia , Humanos , Imunoglobulina E/sangue , Queratinócitos/metabolismo , Masculino , Mastócitos/patologia , Camundongos , Antagonistas dos Receptores de Neurocinina-1/farmacologia , Neurotransmissores/farmacologia , Cloreto de Picrila , Substância P/farmacologia , Linfócitos T/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Linfopoietina do Estroma do TimoRESUMO
Contact dermatitis is a form of delayed-type hypersensitivity characterized by localized thickening, papules, redness and vesicles of the skin. A model of contact dermatitis involving repeated challenge of a hapten is adapted to assess dermatitis as characterized by skin thickening. Recently, it was reported that neutrophils have crucial roles in contact hypersensitivity. We thus examined the involvement of CXC chemokines bearing the glutamic acid-leucine-arginine (ELR) motif ("ELR+ chemokines") and neutrophils in the ear swelling induced by 2,4,6-trinitrochlorobenzene (TNCB) challenges in the present study. Mice were sensitized by application of TNCB on their abdominal skin. They were then challenged thrice with TNCB to the ear. The CXCR2 antagonist SB225002 (9 mg/kg, i.p.) was administered before each TNCB challenge. Gene expressions and protein levels of the ELR+ chemokines CXCL1, 2 and 5 was increased markedly in mouse ear after the final TNCB challenge. In addition, we indicated that gene expression of CXCL1 was enhanced in the epidermis and dermis upon TNCB challenge. Expression of the CXCL2 gene was enhanced in the epidermis, and that of the CXCL5 gene was enhanced in the dermis. The swelling induced by TNCB challenges was significantly attenuated by SB225002. Furthermore, the increases in myeloperoxidase activity, and expression of myeloperoxidase and neutrophil elastase induced by TNCB challenge in mouse ear were inhibited by SB225002. These data suggest that ear swelling resulting from TNCB challenges might be concerned by upregulated ELR+ chemokine-induced neutrophil recruitment.