Loomer P M, Ellen R P, Tenenbaum H C
Department of Periodontics, University of Toronto, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, ON.
J Periodontol. 1998 Nov;69(11):1263-70. doi: 10.1902/jop.1998.69.11.1263.
This study was undertaken to determine the direct effects of extracts derived from Porphyromonas gingivalis on bone formation and mineral resorption in an osteogenic/osteoclastic cell in vitro co-culture model. Osteogenic bone marrow derived stromal cells were isolated from 18-day old embryonic chickens, while osteoclastic cells were isolated from laying white Leghorn hens on calcium deficient diets. Osteoclastic cells (5 x 10(5)) were seeded onto mineral thin films and suspended above osteogenic cells (1 x 10(4)) already plated on the bottoms of tissue culture plate wells. Sonicated P. gingivalis 2561 extracts were prepared from whole bacterial cells and added in varying proportions (0 to 2 microg/ml) to the co-culture growth medium. These co-cultures, and appropriate mono-culture controls, were incubated for a further 4 days. Parameters of bone forming cell activity including alkaline phosphatase activity, calcium and inorganic phosphate accumulation were performed on the osteogenic cells. Mineral substrate resorption by osteoclastic cells was assessed morphometrically. In their respective mono-cultures, the addition of P. gingivalis sonicate to the culture medium had no effect on osteoclastic mineral resorption, but significantly inhibited osteogenesis (up to 45%; P <0.05). In co-cultures, however, the sonicate induced significant increases in mineral resorption (up to 70%; P <0.05), whereas bone forming cell activity was still inhibited, although to a significantly lesser extent than in mono-cultures (up to 25%; P <0.05). These results suggest that P. gingivalis sonicate induced up-regulation of mineral resorption may be mediated via osteogenic cells.
本研究旨在确定牙龈卟啉单胞菌提取物对体外成骨细胞/破骨细胞共培养模型中骨形成和矿物质吸收的直接影响。成骨骨髓来源的基质细胞从18日龄的胚胎鸡中分离，而破骨细胞从缺钙饮食的产蛋白来航母鸡中分离。将破骨细胞（5×10⁵）接种到矿物质薄膜上，并悬浮在已接种于组织培养板孔底部的成骨细胞（1×10⁴）上方。从全菌细胞制备超声处理的牙龈卟啉单胞菌2561提取物，并以不同比例（0至2微克/毫升）添加到共培养生长培养基中。这些共培养物以及适当的单培养对照再孵育4天。对成骨细胞进行骨形成细胞活性参数检测，包括碱性磷酸酶活性、钙和无机磷积累。通过形态计量学评估破骨细胞对矿物质底物的吸收。在各自的单培养中，向培养基中添加牙龈卟啉单胞菌超声裂解物对破骨细胞矿物质吸收没有影响，但显著抑制成骨（高达45%；P<0.05）。然而，在共培养中，超声裂解物诱导矿物质吸收显著增加（高达70%；P<0.05），而成骨细胞活性仍受到抑制，尽管程度明显低于单培养（高达25%；P<0.05）。这些结果表明，牙龈卟啉单胞菌超声裂解物诱导的矿物质吸收上调可能是通过成骨细胞介导的。
