Effects of Bone CS-Proteoglycans, DS-Decorin, and DS-Biglycan on Hydroxyapatite Formation in a Gelatin Gel

被引：0

作者：

A. L. Boskey

L. Spevak

S. B. Doty

L. Rosenberg

机构：

[1] The Hospital for Special Surgery,

[2] 535 East 70th Street,undefined

[3] New York,undefined

[4] New York 10021,undefined

[5] USA,undefined

[6] Montefiore Hospital,undefined

[7] New York,undefined

[8] New York,undefined

[9] USA,undefined

来源：

Calcified Tissue International | 1997年 / 61卷

关键词：

Key words: Mineralization — Biglycan — Decorin — Hydroxyapatite — Bone proteoglycan.;

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摘要：

The small leucine-rich bone proteoglycans, biglycan and decorin, can be purified by chromatography on hydroxyapatite columns, demonstrating their potential affinities for bone apatite. To determine their effects on in vitro apatite formation and growth, a mixture of the chondroitin-sulfate (CS) bone proteoglycans, or purified fractions of the dermatan sulfate (DS) containing proteoglycans, DS-decorin and DS-biglycan obtained from skin and articular cartilage, respectively, were analyzed in a gelatin gel diffusion system in which apatite formation occurs in the absence of proteins in a 3.5 day period. Low concentrations of the bone CS-proteoglycan mixture and low DS-biglycan concentrations (5–25 μg/ml) increased apatite formation relative to proteoglycan-free controls at 3.5 days. The CS-proteoglycan mixture was less effective at 50 μg/ml than at 10 μg/ml. DS-biglycan was similarly most effective at 5–25 μg/ml. At 5 days, when apatite growth and proliferation were assessed, 10 and 50 μg/ml of both CS-bone proteoglycan and DS-biglycan increased mineral yields. DS-decorin, in contrast, had no significant effect on mineral accumulation at any of these concentrations. In seeded growth experiments, 1 and 10 μg/ml CS-proteoglycan and 10 and 50 μg/ml DS-biglycan were significant effective inhibitors of mineral accretion, whereas DS-decorin showed no tendency to inhibit seeded growth. Using molar extinction coefficients to determine concentrations, the binding of DS-biglycan and DS-decorin to apatite (specific surface 54 m2/g) was determined using a Langmuir adsorption isotherm model. DS-biglycan had a greater affinity for apatite than DS-decorin (0.285 ml/μmol versus 0.0098 ml/μmol). DS-biglycan binding was more specific with fewer binding sites (3.5 μmol/m2 compared with 18.2 μmol/m2 for DS-decorin). Data suggest that of the small proteoglycans, biglycan may play a more significant role than decorin in the regulation of mineralization.

引用

页码：298 / 305

页数：7