Assuntos
Apoptose/genética , Proteína Ligante Fas/genética , Fibroblastos/citologia , Regulação da Expressão Gênica , Integrina beta3/biossíntese , Antígenos Thy-1/genética , Animais , Proliferação de Células/genética , Células Cultivadas , Células Epidérmicas , Fibroblastos/metabolismo , Camundongos , Camundongos Knockout , Modelos Animais , Sensibilidade e Especificidade , Regulação para CimaRESUMO
Fibroblasts provide matrix and regulatory mediators to the microenvironment and thereby contribute to maintenance of tissue homeostasis, wound healing, and tumor progression. In the present study, we addressed the functional relevance of Thy-1 for fibroblast functions in vitro and in vivo. Using fibroblasts from Thy-1(-/-) and wild-type mice, recombinant expression of Thy-1, and analysis of the interaction of fibroblasts with immobilized Thy-1, we showed that Thy-1 has a crucial role in the control of cell growth by suppressing proliferation and promoting apoptosis and differentiation of dermal fibroblasts. Function-blocking studies revealed that Thy-1 mediates the control of apoptosis and proliferation via modulation of ß3 integrin function. Interestingly, Thy-1-mediated growth control appears to be a more general mechanism because it also regulates growth of tumor cells of different origin dependent on their ß3 integrin expression. In summary, our findings point to an important role of Thy-1 in controlling the balance between proliferation and differentiation in dermal fibroblasts.
Assuntos
Diferenciação Celular/genética , Proliferação de Células/genética , Fibroblastos/citologia , Antígenos Thy-1/genética , Animais , Apoptose/genética , Células Cultivadas , Modelos Animais de Doenças , Células Epidérmicas , Imunofluorescência , Regulação da Expressão Gênica , Immunoblotting , Integrina beta3/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/análise , Reação em Cadeia da Polimerase em Tempo Real , Cicatrização/genéticaRESUMO
Leukocyte trafficking and recruitment is a critical process in host immune surveillance and in inflammatory diseases. Extracellular cyclophilins (eCyps) have been identified as a novel class of chemotactic mediators. The impact of eCyp/CD147 interactions for the recruitment of leukocytes during inflammation was analyzed using a structurally simplified cell-impermeable eCyp inhibitor. This compound was highly effective at inhibiting leukocyte migration toward CypA in vitro as well as in the recruitment of leukocytes during inflammation in a mouse model of experimentally induced peritonitis and delayed-type hypersensitivity reaction. By using CD147-/- mice in combination with the cell-impermeable eCyp inhibitor, we were able to show that the action of eCyps in inflammation is exclusively mediated by interaction with CD147. Our findings suggest that blocking eCyps may be an effective therapeutic target for reducing inflammatory diseases associated with leukocyte recruitment.
Assuntos
Anti-Inflamatórios/farmacologia , Basigina/metabolismo , Ciclosporina/farmacologia , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/metabolismo , Animais , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/química , Anti-Inflamatórios/metabolismo , Quimiotaxia de Leucócito/efeitos dos fármacos , Ciclofilinas/antagonistas & inibidores , Ciclosporina/síntese química , Ciclosporina/química , Ciclosporina/metabolismo , Humanos , Células Jurkat , Leucócitos/citologia , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Camundongos , PermeabilidadeRESUMO
The cell adhesion molecule Thy-1 (CD90) mediates the adhesion of melanoma cells to activated human endothelial cells (EC) via the interaction with the αvß3-integrin on the tumor cells in vitro. Here, we report a strong expression of Thy-1 on both blood vessel and lymphatic EC in melanoma and melanoma metastases. Vascular endothelial growth factor and tumor necrosis factor-α were identified as inducers of Thy-1 expression on EC in vitro. The physiological role of Thy-1 for lymphogenic and hematogenic metastasis of melanoma cells was substantiated in an experimental metastasis model using B16/F10 melanoma cells. Mice lacking Thy-1 showed markedly diminished experimental lung metastasis after injection of B16/F10 melanoma cells compared to wild-type littermate controls. In addition, on generation of a primary subcutaneous tumor, metastasis to regional lymph nodes was clearly reduced in Thy-1(-/-) mice. However, Thy-1 deletion did not affect subcutaneous primary tumor growth, tumor-induced recruitment of inflammatory cells or T cells, angiogenesis, or T-cell activation. In conclusion, Thy-1 contributes to metastasis of melanoma cells by mechanisms likely involving a Thy-1-mediated adhesion of melanoma cells to EC.
