Studies of morphologically atypical (“sprouting”) cultures of bovine aortic endothelial cells. Growth characteristics and connective tissue protein synthesis

Abstract

Morphologic and biochemical studies were performed on cultures of bovine aortic endothelial cells which had developed a second growth pattern that has been referred to as "sprouting" (Gospodarowicz and Mecher, '78; Schwartz '78). These morphologically atypical cells undergrew the intact endothelial cell monolayer and appeared only after the cells had reached confluence. They were ultrastructurally very similar to endothelial cells, but synthesized reduced amounts of fibronectin and a predominance of type I procollagen, rather than the types III and IV procollagens synthesized by monolayer endothelial cells. It is suggested that these cells represent phenotypically altered endothelial cells that differ in biosynthesis of secreted proteins and display a reduced contact-inhibition.

LDL, scavenger, and beta-VLDL receptors on aortic endothelial cells.

“…6 It was found 28 that in macrophages the activity of the scavenger receptor was not regulated by preincubation with lipoproteins. In the present study, the decrease in scavenger receptor activity could be the result of an increase in the number of "sprouting" cells in the population 29 which was observed after incubation with MDA-LDL (data not shown). Sprouting cells are phenotypically altered endothelial cells that are known to differ in the biosynthesis of some secreted proteins which also display reduced contact inhibition.…”

Modulation of extracellular matrix proteins by endothelial cells undergoing angiogenesis in vitro.

“…28 - 44 The sprouting cells are responsible for the formation of endothelial tubes in vitro. 28 Why certain cultures spontaneously exhibit this sprouting growth pattern while others maintain a contact-inhibited monolayer is not understood.…”

Adenovirus-mediated Transfer of a Truncated Transforming Growth Factor-β (TGF-β) Type II Receptor Completely and Specifically Abolishes Diverse Signaling by TGF-β in Vascular Wall Cells in Primary Culture

“…Arterial endothelial cells (EC) and smooth muscle cells (SMC) were primarily prepared from the bovine thoracic aorta as described previously (18,19) and maintained in Dulbecco's modified Eagle's medium (DMEM) (Life Technologies, Inc.) with 10% fetal calf serum (Hyclone Lab., Logan, UT). Each medium contained 100 IU/ml of penicillin and 50 g/ml of streptomycin.…”