The effect of glucocorticoid on the synthesis of biglycan and decorin in human osteoblasts and bone marrow stromal cells.
The effect of glucocorticoid on the synthesis of biglycan and decorin in human osteoblasts and bone marrow stromal cells.
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DOI：
10.1210/endo.135.6.7988427
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发表时间：
1994-12
期刊：
影响因子：
4.8
通讯作者：
S. Kimoto;S. L. Cheng;S. Zhang;L. Avioli
中科院分区：
文献类型：
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作者：
S. Kimoto;S. L. Cheng;S. Zhang;L. Avioli
我们之前已经证明，糖皮质激素诱导人骨髓基质细胞（BMSC）分化为表达成熟成骨细胞表型的细胞。由于糖皮质激素对骨细胞外基质蛋白合成有显着影响，并且蛋白聚糖是骨基质的重要组成部分，可能调节成骨细胞的分化和生物活性，因此我们研究了地塞米松（Dex）对成人骨髓间充质干细胞和人成骨细胞（HOB）中小蛋白聚糖[核心蛋白聚糖（DCN）和双聚糖（BGN）]合成的影响。首次传代的HOB和BMSC用乙醇或10(-7)M Dex处理7天。处理后，细胞单独用[35S]SO4或[35S]SO4和[3H]亮氨酸一起代谢标记24小时。收集条件培养基，并用 4 M HCl 提取细胞层。对提取物和条件培养基进行凝胶过滤和离子交换色谱。直接或在免疫沉淀后通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析含有放射性标记蛋白聚糖的级分。 Dex 处理导致条件培养基和 HOB 培养物细胞层中 DCN 显着增加，BGN 相应减少。在经Dex处理的BMSC培养物中，条件培养基和细胞层中的BGN均减少，而大多数培养物中的DCN则受到刺激。 Northern 印迹分析表明，在所有 HOB 培养物以及所分析的 8 个 BMSC 培养物中的 7 个中，Dex 均增加了 DCN 的稳态信使 RNA (mRNA) 浓度。在 HOB 和 BMSC 培养物中，Dex 均降低了 BGN 的稳态 mRNA 水平。 HOB 和 BMSC（有反应时）中 Dex 对 DCN 和 BGN mRNA 的调节呈剂量依赖性。时程分析表明，仅需 1 天的 Dex 治疗就足以降低 BMSC 中的 BGN mRNA 并增加 DCN mRNA（观察时）水平；该调节周期为 4 周，在此期间 BMSC 的细胞外基质被矿化。治疗 1 天后，Dex 对 HOB 中 DCN 和 BGN 稳态 mRNA 水平的影响也很明显。这些累积的结果表明，Dex 调节人骨髓基质骨祖细胞和成熟成骨细胞中小蛋白聚糖的合成。
We have previously demonstrated that glucocorticoids induce differentiation of human bone marrow stromal cells (BMSC) into cells expressing mature osteoblast phenotype. As glucocorticoids have marked effects on extracellular matrix protein synthesis in bone, and because proteoglycans are important components of bone matrix and may condition the differentiation and biological activities of osteoblasts, we studied the effects of dexamethasone (Dex) on the synthesis of small proteoglycans [decorin (DCN) and biglycan (BGN)] in adult human BMSC and human osteoblasts (HOB). First passaged HOB and BMSC were treated with either ethanol or 10(-7) M Dex for 7 days. After treatment, the cells were metabolically labeled with either [35S]SO4 alone or [35S]SO4 and [3H]leucine together for 24 h. Conditioned media were collected, and cell layers were extracted with 4 M guanidine HCl. The extracts and conditioned media were subjected to gel filtration and ion exchange chromatography. Fractions containing radiolabeled proteoglycans were analyzed either directly or after immunoprecipitation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Dex treatment resulted in a dramatic increase in DCN and an associated decrease in BGN in both the conditioned medium and the cell layer of HOB cultures. In Dex-treated BMSC cultures, BGN was decreased in both the conditioned medium and cell layer, whereas DCN was stimulated in the majority of cultures. Northern blot analysis indicated that steady state messenger RNA (mRNA) concentration of DCN was increased by Dex in all of the HOB cultures and in seven of eight BMSC cultures analyzed. The steady state mRNA level of BGN was decreased by Dex in both HOB and BMSC cultures. The regulation of DCN and BGN mRNA by Dex in both HOB and BMSC (when responsive) was dose dependent. Time-course analysis indicated that as little as 1 day of treatment with Dex was sufficient to decrease BGN mRNA and increase DCN mRNA (when observed) levels in BMSC; the regulation spanned a 4-week interval, during which the extracellular matrix of BMSC was mineralized. The effect of Dex on the steady state mRNA levels of DCN and BGN in HOB was also apparent after 1 day of treatment. These accumulated results suggest that Dex modulates the synthesis of small proteoglycans in both human bone marrow stromal osteoprogenitor cells and mature osteoblasts.