Irradiation of bovine aortic endothelial cells enhances the synthesis and secretion of sulphated glycosaminoglycans.
The effect of X-irradiation on the synthesis of heparan sulphate (HS) and chondroitin/dermatan sulphate (CS/DS) by bovine aortic endothelial cells (BAEC), was studied by measuring the incorporation of [35S]sulphate and [3H]glucosamine into newly synthesized glycosaminoglycan (GAG) chains. Medium extracts from irradiated cultures (5Gy) were found to contain approx. 130% more HS and 200% more CS/DS than unirradiated controls. Smaller increases were observed in cellular extracts, irradiated cultures (5Gy) containing approx. 60% more HS and 100% more CS/DS than unirradiated controls. Structural studies showed no significant changes occurred upon irradiation in either the amounts or distribution of N- and O-sulphate groups in the HS molecule. Values for N-sulphation of 41.1% control and 41.5% irradiated (5Gy) were obtained, the corresponding values for O-sulphation being 19.9% control and 20.2% irradiated. Isotope incorporation data indicated that sulphation of CS/DS may decrease after irradiation, however, analysis of chondroitin ABC lyase derived disaccharides showed no changes in the proportion of non-sulphated and O-sulphated disaccharides. The present study indicates that X-irradiation stimulates the synthesis and secretion of HS and CS/DS proteoglycans (PGs) by BAEC. This could be relevant to many features which are found to be indicative of radiation-induced damage.
Pye
D A
DA
Department of Clinical Research, Christie Hospital, Manchester, UK.
Kumar
S
S
Wang
M J
MJ
Hunter
R D
RD
D000818:Animals; D001011:Aorta; D002417:Cattle; D002478:Cells, Cultured; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004307:Dose-Response Relationship, Radiation; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000378:metabolism / Q000528:radiation effects*; D005944:Glucosamine / Q000378:metabolism; D006025:Glycosaminoglycans / Q000096:biosynthesis* / Q000302:isolation & purification; D008970:Molecular Weight; D012588:Scintillation Counting; D013431:Sulfates / Q000378:metabolism*; D013462:Sulfur Radioisotopes; D014316:Tritium; D014965:X-Rays
D006025:Glycosaminoglycans; D013431:Sulfates; D013462:Sulfur Radioisotopes; D014316:Tritium; D005944:Glucosamine