RESUMO
BACKGROUND: Matrix metalloproteinases (MMPs) contribute to matrix remodelling in venous leg ulcers. Extracellular MMP inducer (EMMPRIN; CD147) has been reported to increase MMP expression, and membrane type 1 MMP (MT1-MMP) has been implicated in the activation of MMPs. OBJECTIVES: To examine whether and to what degree EMMPRIN, MMP-2, MT1-MMP and membrane type 2 MMP (MT2-MMP) are expressed in venous leg ulcers as well as the association with MMP activity. METHODS: EMMPRIN, MMP-2, MT1-MMP and MT2-MMP were analysed by zymography and immunohistochemistry in biopsies from healthy skin and lesional tissue from venous leg ulcers. RESULTS: Zymography provided direct evidence of increased proteolytic activity of MMP-2 in lesional skin in comparison with healthy controls. Immunostaining showed intense expression of EMMPRIN, MMP-2, MT1-MMP and MT2-MMP in dermal structures of venous leg ulcers, whereas only EMMPRIN and MMP-2 showed elevated expression in perivascular regions. Our findings indicate that venous leg ulcers are characterized by elevated expression of EMMPRIN, MMP-2, MT1-MMP and MT2-MMP. The immunohistological findings of skin alterations reflect the dynamic process of activation of soluble and membrane-bound MMPs, which may be highly induced by EMMPRIN. CONCLUSIONS: These data suggest for the first time that membrane-bound MMPs may favour enhanced turnover of the extracellular matrix and support unrestrained MMP activity in venous leg ulcers.
Assuntos
Antígenos CD , Antígenos de Neoplasias , Glicoproteínas de Membrana/metabolismo , Metaloendopeptidases/metabolismo , Úlcera Varicosa/metabolismo , Basigina , Doença Crônica , Colagenases/metabolismo , Eletroforese em Gel de Poliacrilamida/métodos , Humanos , Metaloproteinase 15 da Matriz , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinases da Matriz Associadas à Membrana , Úlcera Varicosa/enzimologiaRESUMO
Stasis dermatitis is a common disorder, which is a consequence of impaired venous drainage of the legs. It is characterized histologically by proliferation of small blood vessels in the papillary dermis. This neovascularization may lead occasionally to the formation of discrete papules due to inflammatory processes. In order to evaluate the role of matrix metalloproteinases (MMPs) in the acute phase of chronic venous insufficiency, we examined the production of MMP-1, -2, -13 and tissue inhibitors of metalloproteinase (TIMP)-1 and -2 in lesional skin of stasis dermatitis. A total of 19 patients affected by stasis dermatitis were included in this experimental study. Polymerase chain reaction, western blot and immunohistochemical studies on tissue specimen were performed. In lesional skin of stasis dermatitis, there was elevated gene expression and immunoreactivity for MMP-1, -2 and -13 in comparison to healthy controls. In contrast, genexpression and immunoreactivity for TIMP-1 and -2 were diminished in stasis dermatitis in comparison with healthy controls. Overexpression and production of MMP-1, -2 and -13 without inhibitory effects could be the result of cytokine mediated induction. Matrix metalloproteinases (MMPs) may play an important role in the remodeling of lesional skin in stasis dermatitis.
Assuntos
Colagenases/metabolismo , Dermatite/enzimologia , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Insuficiência Venosa/enzimologia , Idoso , Sequência de Bases , Estudos de Casos e Controles , Colagenases/genética , Primers do DNA/genética , Dermatite/etiologia , Dermatite/genética , Feminino , Humanos , Imuno-Histoquímica , Inflamação/enzimologia , Inflamação/etiologia , Inflamação/genética , Masculino , Metaloproteinase 1 da Matriz/genética , Metaloproteinase 13 da Matriz , Metaloproteinase 2 da Matriz/genética , Pessoa de Meia-Idade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Inibidor Tecidual de Metaloproteinase-2/metabolismo , Regulação para Cima , Insuficiência Venosa/complicações , Insuficiência Venosa/genéticaRESUMO
Healing of venous leg ulcers depends on the adhesive interaction and formation of new vascular cells. Angiogenesis on the surface of angiogenic blood vessels requires the vascular integrin alphavbeta3 also known as the vitronectin receptor. Autologous platelet-derived wound healing factor (autologous PDWHF) has been described to regulate the wound healing process by forming granulation tissue in the early healing phase. Here we analysed the influence of autologous PDWHF on the expression of the alphavbeta3 integrin in tissue specimen of venous leg ulcers in comparison with placebo treated controls by using reverse transcriptase-polymerase chain reaction and immunohistochemistry. Our investigations provide evidence that mRNA and protein expression of alphavbeta3 were significantly increased in healing venous leg ulcers after 96 h treatment (p<0.05), whereas the total amount of alphavbeta3 mRNA and protein was not altered in placebo treated patients. In healing leg ulcers the alphavbeta3 integrin was predominantly localized around capillary vessels preferentially at sites of newly formed granulation tissue. Placebo controlled patients displayed no altered expression of the alphavbeta3 integrin in biopsy specimen. These findings suggest that topical autologous platelet-derived wound healing factor influences the process of angiogenesis/revascularization via alphavbeta3 integrin-expression hereby promoting granulation tissue formation in healing leg ulcers.
