TY - JOUR
T1 - Relationship between cellular shape and receptor-mediated endocytosis
T2 - An ultrastructural and morphometric study in rat Kupffer cells
AU - Dini, Luciana
AU - Ruzittu, Mariateresa
AU - Carlà, Emanuela C.
AU - Falasca, Laura
PY - 1998/4
Y1 - 1998/4
N2 - The relationship between cellular shape (i.e., size, volume, presence of microvilli, pseudopodia, flat or round shape) and receptor-mediated endocytotic activities (i.e., binding and internalization) was investigated using intact liver as well as freshly isolated Kupffer cells and Kupffer cells in culture. The morphological features of Kupffer cells were reconstructed by three-dimentional analysis from in situ experiments and by densitometric analysis of cells in suspension and in culture. By morphometry at the ultrastructural level, different cellular shapes were compared with the respective capacities for binding and internalization of glycoproteins with terminal galactosyl residues. The number of asialoglycoprotein-gold particles bound to the cell surface or internalized into endosomes was calculated. Our data show that differences in cellular shape, mainly related to the reduction of projection and microvilli and to the roundness of cell surface, accompany modulation of galactose-specific receptors in rat Kupffer cells, thus supporting the hypothesis that cell morphology is affected by endocytic activities. In fact, the progressive reduction in microvilli projections and cellular roundness is paralleled by the progressive decrement of both binding and uptake capacity from in situ, freshly isolated and cultured Kupffer cells.
AB - The relationship between cellular shape (i.e., size, volume, presence of microvilli, pseudopodia, flat or round shape) and receptor-mediated endocytotic activities (i.e., binding and internalization) was investigated using intact liver as well as freshly isolated Kupffer cells and Kupffer cells in culture. The morphological features of Kupffer cells were reconstructed by three-dimentional analysis from in situ experiments and by densitometric analysis of cells in suspension and in culture. By morphometry at the ultrastructural level, different cellular shapes were compared with the respective capacities for binding and internalization of glycoproteins with terminal galactosyl residues. The number of asialoglycoprotein-gold particles bound to the cell surface or internalized into endosomes was calculated. Our data show that differences in cellular shape, mainly related to the reduction of projection and microvilli and to the roundness of cell surface, accompany modulation of galactose-specific receptors in rat Kupffer cells, thus supporting the hypothesis that cell morphology is affected by endocytic activities. In fact, the progressive reduction in microvilli projections and cellular roundness is paralleled by the progressive decrement of both binding and uptake capacity from in situ, freshly isolated and cultured Kupffer cells.
KW - Kupffer cells
KW - Morphometry
KW - Receptor-mediated endocytosis
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M3 - Article
C2 - 9588768
AN - SCOPUS:0031966511
VL - 18
SP - 99
EP - 109
JO - Liver
JF - Liver
SN - 0106-9543
IS - 2
ER -