Capillary endothelial cells secrete a heparin-binding mitogen for pericytes.
The cells of the retinal microvasculature consist predominantly of mesodermally derived pericytes and endothelial cells, and the regulatory factors which govern their co-ordinated growth and define their phenotypic characteristics in vivo may be regarded as key elements of the angiogenic process. An investigation of these cells in co-culture experiments has led to the identification of a potent mitogen for pericytes in medium conditioned by retinal endothelial cells (EC-FBS). EC-FBS activity was shown to be non-dialyzable, and stable to both heat and acid treatment. EC-FBS was inactivated by passage over a heparin-Agarose column. The column-bound activity could be eluted as a single peak at approximately 1.0 M NaCl. Stimulation of pericyte growth was also achieved with platelet-derived growth factor (PDGF), acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) and could be blocked by using the appropriate antiserum (anti-PDGF or anti-aFGF). Neither antisera, however, blocked the activity of EC-FBS. The EC-FBS mitogen markedly altered the phenotypic behavior of pericytes compared with PDGF and the FGFs; yet, unlike them, it failed to stimulate the growth of smooth muscle cells (SMC) and Balb/c 3T3 cells.
Swinscoe
J C
JC
Department of Anatomy and Cell Biology, School of Medicine, University of North Dakota, Grand Forks 58202.
Carlson
E C
EC
D000818:Animals; D002196:Capillaries / Q000166:cytology / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003470:Culture Media; D004730:Endothelium, Vascular / Q000378:metabolism*; D005346:Fibroblast Growth Factors / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006493:Heparin / Q000378:metabolism; D006801:Humans; D051379:Mice; D008934:Mitogens / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D010982:Platelet-Derived Growth Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology; D051381:Rats; D012171:Retinal Vessels / Q000166:cytology / Q000378:metabolism
D003470:Culture Media; D008934:Mitogens; D010982:Platelet-Derived Growth Factor; D005346:Fibroblast Growth Factors; D006493:Heparin