Reffitt D M, Ogston N, Jugdaohsingh R, Cheung H F J, Evans B A J, Thompson R P H, Powell J J, Hampson G N
Gastrointestinal Laboratory, The Rayne Institute, St Thomas' Hospital, London SE1 7EH, UK.
Bone. 2003 Feb;32(2):127-35. doi: 10.1016/s8756-3282(02)00950-x.
Silicon deficiency in animals leads to bone defects. This element may therefore play an important role in bone metabolism. Silicon is absorbed from the diet as orthosilicic acid and concentrations in plasma are 5-20 microM. The in vitro effects of orthosilicic acid (0-50 microM) on collagen type 1 synthesis was investigated using the human osteosarcoma cell line (MG-63), primary osteoblast-like cells derived from human bone marrow stromal cells, and an immortalized human early osteoblastic cell line (HCC1). Collagen type 1 mRNA expression and prolyl hydroxylase activity were also determined in the MG-63 cells. Alkaline phosphatase and osteocalcin (osteoblastic differentiation) were assessed both at the protein and the mRNA level in MG-63 cells treated with orthosilicic acid. Collagen type 1 synthesis increased in all treated cells at orthosilicic acid concentrations of 10 and 20 microM, although the effects were more marked in the clonal cell lines (MG-63, HCCl 1.75- and 1.8-fold, respectively, P < 0.001, compared to 1.45-fold in the primary cell lines). Treatment at 50 microM resulted in a smaller increase in collagen type 1 synthesis (MG-63 1.45-fold, P = 0.004). The effect of orthosilicic acid was abolished in the presence of prolyl hydroxylase inhibitors. No change in collagen type 1 mRNA level was seen in treated MG-63 cells. Alkaline phosphatase activity and osteocalcin were significantly increased (1.5, 1.2-fold at concentrations of 10 and 20 microM, respectively, P < 0.05). Gene expression of alkaline phosphatase and osteocalcin also increased significantly following treatment. In conclusion, orthosilicic acid at physiological concentrations stimulates collagen type 1 synthesis in human osteoblast-like cells and enhances osteoblastic differentiation.
动物体内硅缺乏会导致骨骼缺陷。因此，这种元素可能在骨代谢中发挥重要作用。硅以原硅酸的形式从饮食中吸收，血浆中的浓度为5 - 20微摩尔。使用人骨肉瘤细胞系（MG - 63）、源自人骨髓基质细胞的原代成骨样细胞以及永生化的人早期成骨细胞系（HCC1），研究了原硅酸（0 - 50微摩尔）对I型胶原蛋白合成的体外影响。还测定了MG - 63细胞中I型胶原蛋白mRNA表达和脯氨酰羟化酶活性。在用原硅酸处理的MG - 63细胞中，在蛋白质和mRNA水平评估了碱性磷酸酶和骨钙素（成骨细胞分化）。在原硅酸浓度为10和20微摩尔时，所有处理细胞中的I型胶原蛋白合成均增加，尽管在克隆细胞系中的作用更明显（MG - 63、HCC1分别增加1.75倍和1.8倍，P < 0.001，而原代细胞系中增加1.45倍）。50微摩尔处理导致I型胶原蛋白合成增加幅度较小（MG - 63增加1.45倍，P = 0.004）。在脯氨酰羟化酶抑制剂存在的情况下，原硅酸的作用被消除。处理后的MG - 63细胞中I型胶原蛋白mRNA水平未见变化。碱性磷酸酶活性和骨钙素显著增加（在10和20微摩尔浓度下分别增加1.5倍和1.2倍，P < 0.05）。处理后碱性磷酸酶和骨钙素的基因表达也显著增加。总之，生理浓度的原硅酸刺激人成骨样细胞中I型胶原蛋白的合成并增强成骨细胞分化。
