Regulation of Angiogenesis in vitro by Collagen Metabolism

• Published in: In Vitro Cellular & Developmental Biology - Animal 1991-12, Vol.27A (12), p.961-966
• Main Authors: Nicosia, Roberto F., Paul Belser, Elena Bonanno, James Diven
• Format: Article
• Language: English
• Subjects: Angiogenesis; Animals; Aorta; Aorta - cytology; Aorta - physiology; Aorta - ultrastructure; Ascorbic Acid - pharmacology; Biological and medical sciences; Blood plasma; Blood Vessels - drug effects; Blood Vessels - physiology; Blood Vessels - ultrastructure; Blood vessels and receptors; Cell Division - drug effects; Cell Division - physiology; Cells, Cultured; Collagen - metabolism; Collagen - physiology; Collagens; Endothelial cells; Extracellular matrix; Extracellular Matrix - metabolism; Fundamental and applied biological sciences. Psychology; Gels; Hydroxyproline - pharmacology; Male; Metabolism; Microscopy, Electron; Microvessels; Neovascularization, Pathologic - physiopathology; Rats; Rats, Inbred F344; Solar fibrils; Vertebrates: cardiovascular system
• ISSN: 0883-8364; 2327-431X; 1543-706X
• DOI: 10.1007/BF02631124

The role of collagen in microvascular growth was investigated using the aortic ring model of angiogenesis. Collagen production by vasoformative outgrowths in plasma clot culture of rat aorta was either stimulated with ascorbic acid or inhibited with the proline analogue cis-hydroxyproline. Microvessels proliferating in the absence of ascorbic acid supplements became ectatic and developed large lumina. In contrast, newly formed microvessels in the presence of ascorbic acid remained small and maintained thin lumina throughout the angiogenic process. Biochemical studies demonstrated enhanced collagen production and deposition in cultures treated with ascorbic acid. Ultrastructural studies of these cultures showed a marked increase in newly formed interstitial collagen in the perivascular matrix and in regions of the plasma clot containing nonendothelial mesenchymal cells. Small microvessels with thin lumina similar to the ones observed in ascorbic acid-treated plasma clot cultures were obtained by growing aortic explants in gels of interstitial collagen in the absence of ascorbic acid. Inhibition of collagen production with the proline analogue cis-hydroxyproline had a marked anti-angiogenic effect in both plasma clot and collagen gel cultures. The anti-angiogenic effect of cis-hydroxyproline was abolished by adding L-proline to the culture medium, thereby restoring normal metabolism. These results support the hypothesis that angiogenesis is regulated by collagen production and suggest that the size of newly formed microvessels is influenced by the degree of collagenization of the extracellular matrix.