Heterogeneidade dos mastócitos e expressão da proteína Anexina A1 em modelo de lesão térmica de segundo grau
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Data
2016-07-29
Autores
Souza, Helena Ribeiro [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O processo de reparo de lesões térmicas pode ser dividido nas fases de inflamação, proliferação e remodelação. No seu processo de desgranulação, os mastócitos (MCs) liberam fatores quimiotáticos, citocinas e proteases, como triptase e quimase, para o meio extracelular, contribuindo na degradação da matriz lesada e síntese de uma nova. Além disso, estudos indicam que os MCs armazenam a proteína anti-inflamatória anexina A1 (AnxA1), envolvida na inflamação, apoptose, crescimento e diferenciação celular. Contudo, não se conhecem relatos da expressão e função da AnxA1 no reparo de queimaduras. Diante disso, os objetivos desse estudo foram quantificar e avaliar a ativação, acúmulo de histamina e heterogeneidade para triptase e quimase dos MCs, bem como, verificar a expressão da AnxA1, quantificar macrófagos, e dosar as citocinas TNF-α, IL-1β, IL-6, IL-10 e a quimiocina MCP-1 em modelo de queimadura de segundo grau em ratos Wistar. Para o desenvolvimento da lesão os animais foram anestesiados e submetidos à aplicação de um bloco metálico aquecido no dorso. Os animais foram divididos em grupos controles e tratados com pomada de sulfadiazina de prata a 1% (SDP 1%). As análises foram realizadas em 3, 7, 14 e 21 dias após injúria, e também em fragmentos de pele normal. Avaliações macroscópicas e histopatológicas da cicatrização confirmaram as características de queimadura de segundo grau e a melhor evolução da cicatrização nos animais tratados. A quantificação dos MCs mostrou grande quantidade de células intactas na pele normal e redução significante dessas células nas fases de inflamação (dia 3) e de proliferação (dia 7). Nas fases de proliferação de matriz (dia 14) e remodelação (dia 21) foi verificada maior quantidade de MCs nos animais controles e essas células foram observadas, principalmente, desgranuladas no dia 14 e intactas no dia 21. Ainda, no grupo tratado aos 7 dias e em ambos os grupos aos 14 dias, foi encontrada diferença entre MCs com grande quantidade de histamina e MCs totais. A análise da heterogeneidade dos MCs revelou maior número de MCs positvos para triptase (MCT) do que para quimase (MCQ) na pele normal e redução de MCTs e MCQs nas primeiras fases da cicatrização. Contudo, na fase de remodelação, muitos MCQs foram observados no grupo controle. A expressão da AnxA1 foi fraca na pele normal com aumento nas fases de inflamação e de proliferação. Aos 21 dias após lesão, a expressão da AnxA1 foi maior nos animais tratados com SDP 1%, no estroma e também em regiões epiteliais próximas à neogênese dos anexos cutâneos. As análises das citocinas mostraram aumento das pró-inflamatórias TNF-α, IL-1β e IL-6, e da citocina anti-inflamatória IL-10, nas fases iniciais do reparo, especialmente nos dias 3 e 7. O mesmo foi observado com relação a quimiocina MCP-1 e a quantificação de macrófagos. Nossos resultados evidenciaram diferenças no número de MCs e na imunomarcação da AnxA1 entre os grupos estudados, moduladas pelo tratamento com a SDP 1% e indicam que essas células e proteínas podem ser alvos terapêuticos no processo de regeneração de queimaduras.
The repair process of thermal injury can be divided into phases of inflammation, proliferation and remodeling. The mast cells (MCs) in their degranulation process, release chemotactic factors, cytokines and proteases, as tryptase and chymase, to the extracellular environment contributing to the degradation of damaged matrix and synthesis of a new one. Moreover, studies indicate that MCs store the antiinflammatory protein annexin A1 (AnxA1) which involved in inflammation, apoptosis, growth and cell differentiation. However, there are no known reports of the expression and function of AnxA1 in burns repair. Thus, the objectives of this study were to quantify, assess the activation, histamine accumulation and heterogeneity for tryptase and chymase of MCs, as well as, check the expression of AnxA1, associated with macrophages quantification and the levels of TNF-α, IL-1β, IL-6, IL-10 and MCP-1 in a second degree burn model in rats. For the development of the lesions, animals were anesthetized for applying a water-heated metal block in the dorso. The animals were divided into control and treated or not with the cream of silver sulfadiazine 1% (SDP 1%). The analyzes were performed on 3, 7, 14 and 21 days after injury, and also in normal skin fragments. Macroscopic and histopathological evaluations of healing confirmed the burning characteristics of second degree and the better progress of wound repair in treated animals. Quantification of MCs showed large amount of intact cells in normal skin and a significant reduction of these cells in the stages of inflammation (day 3) and proliferation (day 7). In the phases of matrix proliferation (day 14) and remodeling (day 21) it was observed increased amount of MCs, only in the control animals, and these cells were mainly degranulated on day 14, but intact on day 21. Also, in the treated group on day 7 and in both groups on day 14, it was found difference between MCs with large amounts of histamine and total MCs. The heterogeneity analysis revealed more MCs positves for tryptase (MCT) than for chymase (MCC) on normal skin and reduced MCTs and MCQs in the early stages of healing. However, in the remodeling phase, many MCCs were observed in the control group. The expression of AnxA1 was low in normal skin and increased in the stages of inflammation and proliferation. On 21 days after injury, the expression of AnxA1 was higher in animals treated with SDP 1% in the stroma and epithelial cells especially in regions close to neogenesis of skin attachments. Analysis of the inflammatory mediators showed an increase pro-inflammatory TNF-α, IL-1β and IL-6 and anti-inflammatory IL-10 cytokines in the early stages of the repair, especially on days 3 and 7. The same was observed for MCP-1 chemokine and quantification of macrophages. Our results showed differences in the number of MCs and AnxA1 expression between groups, that were modulated by treatment with the SDP 1%, indicating that these cells and protein can be used as therapeutic targets in burns regeneration process.
The repair process of thermal injury can be divided into phases of inflammation, proliferation and remodeling. The mast cells (MCs) in their degranulation process, release chemotactic factors, cytokines and proteases, as tryptase and chymase, to the extracellular environment contributing to the degradation of damaged matrix and synthesis of a new one. Moreover, studies indicate that MCs store the antiinflammatory protein annexin A1 (AnxA1) which involved in inflammation, apoptosis, growth and cell differentiation. However, there are no known reports of the expression and function of AnxA1 in burns repair. Thus, the objectives of this study were to quantify, assess the activation, histamine accumulation and heterogeneity for tryptase and chymase of MCs, as well as, check the expression of AnxA1, associated with macrophages quantification and the levels of TNF-α, IL-1β, IL-6, IL-10 and MCP-1 in a second degree burn model in rats. For the development of the lesions, animals were anesthetized for applying a water-heated metal block in the dorso. The animals were divided into control and treated or not with the cream of silver sulfadiazine 1% (SDP 1%). The analyzes were performed on 3, 7, 14 and 21 days after injury, and also in normal skin fragments. Macroscopic and histopathological evaluations of healing confirmed the burning characteristics of second degree and the better progress of wound repair in treated animals. Quantification of MCs showed large amount of intact cells in normal skin and a significant reduction of these cells in the stages of inflammation (day 3) and proliferation (day 7). In the phases of matrix proliferation (day 14) and remodeling (day 21) it was observed increased amount of MCs, only in the control animals, and these cells were mainly degranulated on day 14, but intact on day 21. Also, in the treated group on day 7 and in both groups on day 14, it was found difference between MCs with large amounts of histamine and total MCs. The heterogeneity analysis revealed more MCs positves for tryptase (MCT) than for chymase (MCC) on normal skin and reduced MCTs and MCQs in the early stages of healing. However, in the remodeling phase, many MCCs were observed in the control group. The expression of AnxA1 was low in normal skin and increased in the stages of inflammation and proliferation. On 21 days after injury, the expression of AnxA1 was higher in animals treated with SDP 1% in the stroma and epithelial cells especially in regions close to neogenesis of skin attachments. Analysis of the inflammatory mediators showed an increase pro-inflammatory TNF-α, IL-1β and IL-6 and anti-inflammatory IL-10 cytokines in the early stages of the repair, especially on days 3 and 7. The same was observed for MCP-1 chemokine and quantification of macrophages. Our results showed differences in the number of MCs and AnxA1 expression between groups, that were modulated by treatment with the SDP 1%, indicating that these cells and protein can be used as therapeutic targets in burns regeneration process.
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Palavras-chave
Queimaduras, Cicatrização, Mastócitos, Triptase, Quimase, Anexina A-1, Inflamação, Interleucinas, Burns, Wound healing, Mast cell, Tryptase, Chymase, Inflammation, Interleukins