RESUMO
Interferon (IFN)-γ is mainly secreted by CD4+ T helper 1 (Th1), natural killer (NK) and NKT cells after skin injury. Although IFN-γ is well known regarding its inhibitory effects on collagen synthesis by fibroblasts in vitro, information is limited regarding its role in wound healing in vivo. In the present study, we analyzed how the defect of IFN-γ affects wound healing. Full-thickness wounds were created on the backs of wild type (WT) C57BL/6 and IFN-γ-deficient (KO) mice. We analyzed the percent wound closure, wound breaking strength, accumulation of leukocytes, and expression levels of COL1A1, COL3A1, and matrix metalloproteinases (MMPs). IFN-γKO mice exhibited significant attenuation in wound closure on Day 10 and wound breaking strength on Day 14 after wound creation, characteristics that are associated with prolonged neutrophil accumulation. Expression levels of COL1A1 and COL3A1 mRNA were lower in IFN-γKO than in WT mice, whereas expression levels of MMP-2 (gelatinase) mRNA were significantly greater in IFN-γKO than in WT mice. Moreover, under neutropenic conditions created with anti-Gr-1 monoclonal antibodies, wound closure in IFN-γKO mice was recovered through low MMP-2 expression levels. These results suggest that IFN-γ may be involved in the proliferation and maturation stages of wound healing through the regulation of neutrophilic inflammatory responses.
Assuntos
Regulação Enzimológica da Expressão Gênica/imunologia , Interferon gama/deficiência , Metaloproteinase 2 da Matriz/imunologia , Neutrófilos/imunologia , Cicatrização/imunologia , Animais , Colágeno Tipo I/genética , Colágeno Tipo I/imunologia , Cadeia alfa 1 do Colágeno Tipo I , Colágeno Tipo III/genética , Colágeno Tipo III/imunologia , Ativação Enzimática/genética , Ativação Enzimática/imunologia , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Interferon gama/imunologia , Metaloproteinase 2 da Matriz/genética , Camundongos , Camundongos Knockout , Neutrófilos/patologia , Cicatrização/genéticaRESUMO
The inflammatory response after skin injury involves the secretion of a variety of cytokines and growth factors that are necessary for tissue repair. Caspase recruitment domain-containing protein 9 (CARD9) is an essential signalling adaptor molecule for NF-κB activation upon triggering through C-type lectin receptors (CLRs), which are expressed in macrophages and dendritic cells. However, the role of CARD9 in inflammatory responses at the wound site has not been elucidated. In this study, we analysed the role of CARD9 in the healing process of skin wounds. Wounds were created on the backs of wild-type (WT) C57BL/6 mice and CARD9 gene-disrupted (knockout [KO]) mice. We analysed per cent wound closure, and the wound tissues were harvested for analysis of leucocyte accumulation and cytokine and chemokine expressions. CARD9KO mice exhibited significant attenuation of wound closure compared with WT mice on days 5, 7 and 10 postwounding, which was associated with decreased macrophage accumulation and reduced TNF-α, IL-1ß, CCL3 and CCL4 expressions. These results suggest that CARD9 may be involved in the wound-healing process through the regulation of macrophage-mediated inflammatory responses.
Assuntos
Proteínas Adaptadoras de Sinalização CARD/metabolismo , Macrófagos , Transdução de Sinais , Pele/metabolismo , Pele/patologia , Cicatrização , Animais , Proteínas Adaptadoras de Sinalização CARD/genética , Quimiocina CCL3/genética , Quimiocina CCL3/metabolismo , Feminino , Expressão Gênica , Inflamação/patologia , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Contagem de Leucócitos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro/metabolismo , Pele/lesões , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Cicatrização/efeitos dos fármacos , Zimosan/farmacologiaRESUMO
Dendritic cell-associated C-type lectin-2 (i.e., dectin-2) recognizes fungal polysaccharides, including α-mannan. Dectin-2-mediated recognition of fungi, such as Candida albicans, leads to NF-κB activation, which induces production of inflammatory cytokines. However, the role of dectin-2 in skin wound healing remains unclear. In this study, we sought to determine how dectin-2 deficiency and the administration of α-mannan affected the wound healing process. Full-thickness wounds were created on the backs of wild type C57BL/6 and dectin-2-deficient mice. We analyzed wound closure, histological findings, and re-epithelialization. We also examined the neutrophilic inflammatory responses and neutrophil extracellular trap (NET)-osis at the wound sites after administration of α-mannan. The percent wound closure and re-epithelialization was significantly accelerated in dectin-2-knockout mice compared with wild-type mice on days 3 and 5 after wounding. In contrast, administration of α-mannan delayed wound closure in wild-type mice, and these responses were canceled in dectin-2-knockout mice. Furthermore, mice administered α-mannan, neutrophil infiltration was prolonged, and the expression of citrullinated histone, an indicator of NETosis, at the wound sites was accelerated. Administration of a neutrophil elastase inhibitor significantly improved the delayed wound healing caused by α-mannan. These results suggest that dectin-2 may have a deep impact on the skin wound healing process through regulation of neutrophilic responses.