Previous experiments have shown that human neoplastic and embryonic glial cell lines synthesize and secrete in culture, α2macroglobulin (α2M),a broad spectrum proteinase inhibitor present in serum and extracellular fluids. The present study was aimed to investigate the presence of α2M receptors on glial cell membrane, since several non-neural cell types producing α2M also express α2M receptors. By flow cytometric analysis, immunofluorescence and immunoelectronmicroscopy techniques we demonstrate an α2M receptor-related immunoreactivity on the plasma membrane of a human glioma cell line. Ultrastructural experiments reveal a close colocalization of immunoreactivities for α2M and its receptor in clathrin-coated pits and vesicles, structures typically involved in receptor-mediated endocytic pathways.
Receptor-mediated endocytosis of α2macroglobulin by a glioma cell line
NORI, Stefania Lucia;
1993-01-01
Abstract
Previous experiments have shown that human neoplastic and embryonic glial cell lines synthesize and secrete in culture, α2macroglobulin (α2M),a broad spectrum proteinase inhibitor present in serum and extracellular fluids. The present study was aimed to investigate the presence of α2M receptors on glial cell membrane, since several non-neural cell types producing α2M also express α2M receptors. By flow cytometric analysis, immunofluorescence and immunoelectronmicroscopy techniques we demonstrate an α2M receptor-related immunoreactivity on the plasma membrane of a human glioma cell line. Ultrastructural experiments reveal a close colocalization of immunoreactivities for α2M and its receptor in clathrin-coated pits and vesicles, structures typically involved in receptor-mediated endocytic pathways.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.