儿童配方奶粉对Caco-2细胞钙转运及对成骨细胞增殖、矿化的影响

Effects of A Powdered Toddler Formula on Calcium Transport in Caco-2 Cells and Osteoblast Proliferation and Mineralization

摘要:

为评价某市售儿童成长配方奶粉的补钙和促进骨骼生长能力，以常见市售纯牛奶A作为对照，运用人结肠腺癌细胞（Caco-2）单层模型，研究其对钙离子转运的作用；运用成骨细胞（MC3T3-E1）矿化模型，研究其对成骨细胞增殖与矿化的影响。Caco-2细胞模型结果表明，各剂量组儿童配方奶粉组的钙转运量均高于市售纯牛奶A，但相较空白组无显著性差异（p<0.05）。成骨细胞增殖实验结果表明，5~50 μg/mL的儿童配方奶粉对成骨细胞均有促进增殖作用，增殖速度均在30%以上；并测定细胞碱性磷酸酶活性，当儿童配方奶粉质量浓度为50 μg/mL时，酶活达7.79 U/g蛋白，相较空白组极显著提高（p<0.01），较市售纯牛奶A的效果更稳定。成骨细胞矿化结果表明，5~50 μg/mL儿童配方奶粉能显著促进成骨细胞产生矿化结晶，50 μg/mL时茜素红吸光值均为0.180，对比空白组提高50%以上，较市售纯牛奶A矿化程度更稳定。综上实验结果，儿童配方奶粉虽对钙在小肠上皮的转运吸收无明显促进作用，但很可能通过促进骨生长而对儿童生长发育起作用。

Abstract:

A commercial available children's growth formula was compared with regular commercially available pure dairy milk (control milk A) in terms of their abilities to promote bone growth. Additionally, its effect on calcium transport was evaluated using a human colon adenocarcinoma cell (Caco-2) monolayer model, and its effects on osteoblast proliferation and mineralization was examined with MC3T3-E1 cells. With regard to the promotion of calcium transport, the Caco-2 cell monolayer model showed that commercially available children's growth formula outperformed control milk A at the various doses tested, but its effect did not differ significantly from that of the blank group (p<0.05). The osteoblast proliferation assay showed that 5~50 μg/mL of commercially available children's growth formula could promote the proliferation of osteoblasts, with a proliferation rate of more than 30%. Moreover, in osteoblasts treated with 50 μg/mL of commercially available children's growth formula, the alkaline phosphatase activity was 7.79 U/g of protein, which was significantly higher than that in the blank group (p<0.01). Commercially available children's growth formula also exhibited a more stable effect than control milk A in enhancing the alkaline phosphatase activity. The osteoblast mineralization assay revealed that 5~50 μg/mL of commercially available children's growth formula could significantly promote the formation of mineralized nodules in the cells. In the osteoblasts treated with 50 μg/mL of commercially available children's growth formula, the Alizarin Red absorbance value (0.180) was 50% higher than that of the blank group, and the degree of mineralization was more stable than that in the osteoblasts treated with control milk A. Collectively, our experimental results demonstrate that although commercially available children's growth formula has no significant effect in promoting calcium transport and uptake in the small intestinal epithelium, it may participate in the growth and development of children by promoting bone growth.