ESPELT Maria Victoria
congresos y reuniones científicas
CD13: A novel glycan-binding partner of Galectin-1 in liver endothelium
MALENA MANZI; SARRIAS L; BACIGALUPO, ML; CARABIAS, P; CARLOTA WOLFENSTEIN-TODEL; ELOLA, MT; RABINOVICH GA; ESPELT M.V; TRONCOSO MF
Congreso; GlycoAr; 2019
Galectin-1 (Gal1) belongs to a family of β-galactoside-binding proteins. In hepatocellular carcinoma (HCC), Gal1 is up-regulated and associated with poor patient survival. Previously, we investigated the molecular mechanisms leading to HCC cell dissemination. Recently, we found that hepatocyte-derived Gal1 promotes liver sinusoidal endothelial cell (LSEC) proliferation and migration, suggesting Gal1 contribution to angiogenesis in liver tumors. As no ligands for Gal1 have been described in liver endothelium, we aimed to identify Gal1-binding partners in human SK-HEP-1 LSECs, using a proteomic approach. Recombinant Gal1 was coupled to Affi-Gel 15 matrix and a SK-HEP-1 cell membrane fraction was applied to the Gal1-affinity column. Gal1-binding proteins were eluted with lactose, and subjected to SDS-PAGE and in gel proteolytic digestion. Mass spectrometry analysis identified CD13 as a putative Gal1-binding partner (24% sequence coverage). We confirmed CD13 expression in SK-HEP-1 cells by Western blot and Gal1-CD13 co-localization at cell surface by immunofluorescence. These results demonstrate for the first time, that the glycosylated exopeptidase CD13 is described as a ligand for Gal1. CD13 expression is increased in endothelial cells during tumor-related angiogenesis. Our findings encourage the study of the relevance of Gal1-CD13 interactions in angiogenesis during liver tumor progression.