Characterisation of an endothelial cell proliferation factor from cultured 3T3 cells

Abstract

A high molecular weight polypeptide from cultured 3T3 cells enhanced the rate of proliferation of both vascular and non-vascular bovine endothelial cells in culture, and induced DNA synthesis in resting confluent cultures of these cells. This proliferation factor showed no activity towards bovine aortal smooth muscle cells, dog kidney cells, bovine corneal stromal fibroblasts or BALB/c 3T3 cells. Activity was resistant to 6 M guanidine hydrochloride, β-mercaptoethanol, periodate oxidation or RNase, but was inactivated by heating at 100 °C or by pronase. The isoelectric point was found to be 6.5 and its molecular weight, determined by gel filtration and sedimentation velocity, was 120000 D. These properties clearly distinguish this growth factor from other polypeptide factors known to stimulate endothelial cell proliferation.