title: L-fucose reduces collagen and noncollagen protein production in cultured cerebral microvessel endothelial cells.
abstract: L-fucose is a monosaccharide which is present in low concentrations in normal serum but is increased in diabetes, cancer, and inflammatory diseases. The contribution that abnormal L-fucose levels make to the progression of these disorders is unknown. In a previous study we showed that increased L-fucose concentration reduced proliferation and proteoglycan production by cultured cerebral microvessel endothelial cells. In the present study we show that exposing cerebral microvessel endothelial cells for 2 weeks to medium containing an increased concentration of L-fucose causes a significant decrease in collagen and to a lesser extent noncollagen protein production. The effect of L-fucose on collagen and noncollagen protein production is concentration-dependent: 1 mM L-fucose causes a significant decrease in collagen production but has no effect on noncollagen protein production; a 5 mM L-fucose concentration causes a maximum decrease in both collagen and noncollagen protein production. This defect is unrelated to the reduction in myo-inositol uptake caused by L-fucose and is not prevented by aminoguanidine. Collagen production can be improved by restoring L-fucose-conditioned cells to normal medium. Culturing cells for 2 weeks in medium containing 10 mM L-fucose resulted in a 50% decrease in collagen production, which was restored to 75% of control after cells were transferred to normal medium for 7 days. In contrast, noncollagen protein production was totally restored after 3 days in normal medium. Increasing levels of L-fucose in serum of rats also resulted in a decrease in collagen production. Collagenase digestible incorporation of L-[2,3,4,5-3H]proline into protein of the articular cartilage from rats fed a diet containing 20% L-fucose for 3 weeks was reduced by about 40% compared to rats fed a normal diet. The decrease in collagen production in L-fucose fed rats was less than the reduction that occurred in streptozotocin-induced diabetic rats. These data suggest that changes in L-fucose concentration itself may be a factor in the regulation of collagen production.
authors.affiliation: Department of Internal Medicine, Veterans Affairs Medical Center, Iowa City, IA 52246, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Yorek
authors.forename: C E
authors.initials: CE
authors.lastname: Conner
authors.forename: R G
authors.initials: RG
authors.lastname: Spanheimer
mesh_terms: D000818:Animals; D001921:Brain / Q000098:blood supply; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005643:Fucose / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology; D008297:Male; D051379:Mice; D008833:Microcirculation / Q000378:metabolism; D014176:Protein Biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D005643:Fucose; D003094:Collagen; D005947:Glucose