College of Chemistry & Environmental Science, Chemical Biology Key Laboratory of Hebei Province, Hebei University, Baoding, People's Republic of China.
Biol Trace Elem Res. 2012 Dec;150(1-3):433-40. doi: 10.1007/s12011-012-9486-6. Epub 2012 Aug 14.
A series of experimental methods including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, alkaline phosphatase (ALP) activity measurement, alizarin red S stain and measurement, quantitative real-time reverse transcriptase polymerase chain reaction, and Western blot analysis were employed to assess the effects of LaCl₃ on the proliferation, osteogenic differentiation, and mineralization of a murine preosteoblast cell line MC3T3-E1 at cell and molecular levels. The results indicated that LaCl₃ had dual effects on the proliferation, osteogenic differentiation, and mineralization of MC3T3-E1 cells. First, LaCl₃ promoted the proliferation, osteogenic differentiation, and mineralization of MC3T3-E1 cells at lower concentrations, then had no effects and further turned to inhibit the proliferation, osteogenic differentiation, and mineralization of MC3T3-E1 cells with increasing concentrations. The expression of runt-related transcription factor 2 (Runx2), bone morphogenetic protein 2 (BMP2), ALP, bone sialoprotein (BSP), collagen I (Col I), and osteocalcin (OCN) genes was upregulated in the presence of 0.0001 and 0.1 μM LaCl₃, but these genes were downregulated in the MC3T3-E1 cells treated with 1,000 μM LaCl₃. In addition, the expression of BMP2, Runx2, and OCN proteins was promoted by LaCl₃ at the concentration of 0.0001 μM, but these proteins were downregulated after 1,000 μM LaCl₃ treatment. The results suggest that LaCl₃ likely up- or downregulates the expression of Runx2, which subsequently up- or downregulates osteoblasts marker genes Col I and BMP2 at early stages and ALP and OCN at later stages of differentiation, thus causes to promote or inhibit the proliferation, osteogenic differentiation and mineralization of MC3T3-E1 cells. The results will be helpful for understanding the mechanisms of bone metabolism and application of lanthanum-based compounds in the future.
采用 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐、碱性磷酸酶 (ALP) 活性测定、茜素红 S 染色和测定、实时定量逆转录聚合酶链反应和 Western blot 分析等一系列实验方法，评估了 LaCl₃对鼠前成骨细胞系 MC3T3-E1 细胞水平增殖、成骨分化和矿化的影响。结果表明，LaCl₃对 MC3T3-E1 细胞的增殖、成骨分化和矿化具有双重作用。首先，LaCl₃在较低浓度下促进 MC3T3-E1 细胞的增殖、成骨分化和矿化，然后随着浓度的增加，对 MC3T3-E1 细胞的增殖、成骨分化和矿化没有影响，进一步转为抑制作用。在 0.0001 和 0.1 μM LaCl₃存在的情况下，Runt 相关转录因子 2 (Runx2)、骨形态发生蛋白 2 (BMP2)、碱性磷酸酶 (ALP)、骨涎蛋白 (BSP)、胶原 I (Col I) 和骨钙素 (OCN) 基因的表达上调，但在 MC3T3-E1 细胞用 1000 μM LaCl₃处理时，这些基因下调。此外，在浓度为 0.0001 μM 的 LaCl₃作用下，BMP2、Runx2 和 OCN 蛋白的表达得到促进，但在 1000 μM LaCl₃处理后这些蛋白表达下调。结果表明，LaCl₃可能上调或下调 Runx2 的表达，随后在成骨细胞标志物基因 Col I 和 BMP2 的早期分化阶段以及 ALP 和 OCN 的晚期分化阶段上调或下调，从而促进或抑制 MC3T3-E1 细胞的增殖、成骨分化和矿化。这些结果有助于理解骨代谢的机制，并为未来镧基化合物的应用提供参考。
