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P Bornstein

Publications and source records attributed to P Bornstein.

203 records · Page 12Linked to original sources
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Secretory phenotypes of endothelial cells in culture: comparison of aortic, venous, capillary, and corneal endothelium.

Endothelial cells from different tissues display variations in morphology, intercellular junctions, cell surface and growth properties, and in production of basal lamina components, both in vivo and in vitro. We have investigated the spectra of extracellular proteins secreted by bovine endothelial cells cultured from large vessels, cornea, and capillaries. Aortic, venous, and corneal endothelial cells displayed highly similar patterns of protein synthesis as judged by analysis of the culture medium; the major products were fibronectin, a glycoprotein similar or identical to platelet thrombospondin, and Type III procollagen. Ion-exchange chromatography, followed by peptide mapping, confirmed the presence of EC, a novel endothelial collagen previously described in bovine aortic endothelial cell cultures. Minor variations were found in the collagens of the cell layers: Type III, the predominant interstitial collagen, was associated with the basement membrane Types IV and V and, in the case of corneal endothelium, with Type I. In contrast, capillary endothelial cells secreted significantly more collagen than did the aortic, venous, and corneal cells. Approximately 50% of the protein in the culture medium was collagenous and consisted of Types I and III collagen in a ratio of 2:3. These interstitial collagens were the only types detected in capillary cell layers as well. The pattern and overall rate of collagen synthesis by capillary endothelial cells in vitro contrasted significantly with that of the other endothelial cell types and closely resembled that described for cultures of sprouting endothelium. These alterations in secretory phenotype may reflect: 1) a true difference in cell type between capillary and other types of endothelium, 2) differences resulting from cell isolation and initial culture conditions, or 3) a correlation between growth regulation and protein synthesis.

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PubMedDate not supplied

Endothelial cells from umbilical vein and a hemangioendothelioma secrete basement membrane largely to the exclusion of interstitial procollagens.

The biosynthesis of extracellular matrix proteins by primary cultures of endothelial cells from human umbilical vein, and by clones from a murine hemangioendothelioma, was studied and compared to that reported for endothelium cultured from other sources. Umbilical vein endothelial cells secreted two glycoproteins-fibronectin and thrombospondin-which comprise the major proportion of the protein in the culture media of bovine aortic, venous, and corneal endothelial cells. These biosynthetic products were absent from hemangioendothelioma cultures. However, in contrast to bovine endothelium from large vessels and cornea, which secrete primarily Type III procollagen into the culture medium, both the umbilical vein and hemangioendothelioma cultures secrete Type IV (basement membrane) procollagen. In addition, EC, a novel endothelial collagen type that has been characterized in bovine endothelial cell supernates, was not present in the umbilical vein or tumor-derived endothelium. The production of basement membrane procollagen as the major collagen type in the medium of these cultures probably reflects the nature of the vascular bed from which the endothelial cells originated, rather than differences in species of in cellular isolation and subculture. We suggest that endothelial cells from different vascular environments could display variations in growth, migration, morphology, and response to exogenous blood-borne factors as a result of their relationship to an extracellular matrix/subendothelium composed of diverse structural glycoproteins.

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