Papel de catepsinas na angiogênese induzida por TSP Hep II, um peptídeo derivado do domínio N-terminal da trombospondina-1

• Autor(a) principal: Morais, Francisco Vardiero
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/16299
• topic: Angiogenesis; Thrombospondin-1; Cathepsin; HUVECs; Angiogênese; Trombospondina-1; Catepsina; HUVEC; Neovascularização; Trombospondina-1. Metabolismo; Catepsinas Metabolismo; Células Endoteliais da Veia Umbilical Humana; CNPQ::CIENCIAS BIOLOGICAS::MORFOLOGIA::CITOLOGIA E BIOLOGIA CELULAR

Angiogenesis is an important step during physiologic and pathologic processes, like tumor development. Inhibition of this process is an important strategy in anti-cancer therapies. A coordinate endothelial cellular migration and invasion to the angiogenic site is considered an important step to new blood vessels formation. For this, is essential, the degradation of extracelular matrix by proteases. Matricellular proteins, like thrombonspondin-1 (TSP-1), are involved in this angiogenic process modulating an intermediary state of cell adhesion that facilitates cellular migration. Our group observed that a 18 kDa recombinant fragment of N-terminal domain of TSP-1 (TSP-18) and GAG-dependent peptides from TSP-18 (TSP Hep I and TSP Hep II) could promote angiogenesis. This activity is associated with syndecan-4 binding and activation of protein kinase C (PKC). The present study aims to investigate the role of proteases modulating angiogenesis induced by TSP Hep II. The activity of MMPs associated to cellular membrane of human endothelial cells derived from umbilical veins (HUVEC) was analyzed by zimography. Cellular extract of cells seeded onto TSP Hep II showed that TSP Hep II was unable to up regulate this enzyme. Then, we analyse the presence of cathepsin secreted by HUVECs in the conditioned medium from cells seeded onto TSP Hep II. The peptide was able to induce the secretion and activity of this class of proteases. Using E-64, an specific cystein proteases inhibitor, we established that migration and tubulogenesis, modulated by TSP Hep II, are dependent of cathepsin secretion. Moreover, TSP Hep II was capable to enhance FGF-2 blood vessels formation <i>in vivo</i>, and this effect was cathepsin-dependent. Using specific fluoregenic substrates, we determined that cathepsins B, K and L were not involved in this process. From these data, we conclude that cystein cathepsin is involved in the modutation of angiogeneses by TSP Hep II.