Aortic endothelial cell heterogeneity in vitro Lack of association between morphological phenotype and collagen biosynthesis

Abstract

Previous reports dealing with the characterisation of endothelial cells derived from the same tissue have produced apparently conflicting results in fundamental cellular attributes such as matrix biosynthesis and the ability to form sprouts in vitro. One potential explanation for this discrepancy is that endothelial cells actually comprise a heterogeneous population of cells displaying a significant degree of intra-site variation in phenotype. In order to address this question, we have characterised both cloned and uncloned lines of bovine aortic endothelial cells with respect to (a) their ability to adopt both the cobblestone and sprouting cell phenotypes and (b) matrix biosynthesis by cells displaying these two phenotypes. Data are presented indicating that all of the 18 cloned and 20 uncloned cell lines examined were capable of undergoing a reversible transition between the cobblestone and sprouting cell phenotypes in response to culture conditions. In all cases, sprouting occurred spontaneously in the presence of either serum or platelet-poor plasma and did not require the addition of exogenous factors to the medium. Twelve lines of cells were examined with respect to protein biosynthesis; these lines produced different types of collagens in differing proportions. The pattern of collagen synthesis displayed by every cell line was stable and did not vary with either passage number or batch of serum. The presence of a 3-D gel of native type I collagen increased specifically the synthesis of type IV collagen by one cell line. However, in four other cell lines, even though total synthesis was increased, the type of proteins secreted by these cells was not altered.(ABSTRACT TRUNCATED AT 250 WORDS)

Surface Characterization of the Extracellular Matrix Remaining after Cell Detachment from a Thermoresponsive Polymer

“…LN and FN both contain binding sites for cell-surface receptors, collagen, and other ECM molecules. − Coll IV is believed to serve as the scaffold to which other ECM proteins and constituents bind and align . Although Coll IV is known to be the primary collagen type in endothelial cell basement membranes, it has previously been demonstrated that identical endothelial cells may respond to differences in media or substrate by extruding differing amounts or types of collagen; for this reason we have chosen to analyze both Coll I and Coll IV. , All three proteins provide the means for diverse biological functions, including cell adhesion, morphology, migration, and differentiation of cells. Thus, these proteins are excellent models for the study of the behavior of ECM upon cell detachment from NIPAM-coated surfaces.…”