Loomer P M, Sigusch B, Sukhu B, Ellen R P, Tenenbaum H C
Department of Periodontics, Faculty of Dentistry, University of Toronto, Canada.
Infect Immun. 1994 Apr;62(4):1289-97. doi: 10.1128/iai.62.4.1289-1297.1994.
It is well documented that oral microorganisms play a significant role in the initiation and progression of periodontal disease. By using various in vitro models, it has been shown that some bacteria considered periodontal pathogens or their products can stimulate bone resorption and some other parameters of osteoblast-like cell activity. However, the effects of these organisms and their products on osteogenesis itself are not known. This study was undertaken to determine the direct effects of metabolic products and sonicated extracts of Porphyromonas gingivalis on bone formation in the chick periosteal osteogenesis model. Cultures of P. gingivalis 2561 were grown under standard anaerobic culture conditions. The spent medium was collected, and following centrifugation, sonicated bacterial extracts were prepared from the bacterial pellet. These were added in various proportions to the chick periosteal osteogenesis cultures. Sonicated extracts were further fractionated into five molecular-size ranges and similarly tested. Parameters of osteogenesis, including alkaline phosphatase activity, calcium and Pi accumulation, and collagen synthesis, were measured on 6-day-old cultures. Compared with controls devoid of bacterial products, osteogenesis was inhibited significantly in cultures treated with either conditioned medium or extracts obtained from P. gingivalis. Various amounts of inhibitory activity were observed in the different ultrafiltration molecular-size fractions, with very profound inhibitory effects observed in the < 5-kDa range. Histological observations indicated the presence of cells, some bone, and/or new fibrous connective tissue at all concentrations, indicating that toxicity was not a factor. These results suggest that periodontal pathogens such as P. gingivalis might contribute to the bone loss in periodontal diseases not only by stimulating resorption but, possibly, by inhibiting bone formation directly.
有充分文献记载，口腔微生物在牙周病的发生和发展中起重要作用。通过使用各种体外模型，已表明一些被认为是牙周病原体的细菌或其产物可刺激骨吸收和成骨样细胞活性的其他一些参数。然而，这些微生物及其产物对骨生成本身的影响尚不清楚。本研究旨在确定牙龈卟啉单胞菌的代谢产物和超声提取物对鸡骨膜骨生成模型中骨形成的直接影响。牙龈卟啉单胞菌2561在标准厌氧培养条件下培养。收集用过的培养基，离心后，从细菌沉淀中制备超声细菌提取物。将这些提取物以不同比例添加到鸡骨膜骨生成培养物中。超声提取物进一步分成五个分子大小范围并进行类似测试。在6天大的培养物上测量骨生成参数，包括碱性磷酸酶活性、钙和无机磷积累以及胶原蛋白合成。与不含细菌产物的对照相比，用牙龈卟啉单胞菌条件培养基或提取物处理的培养物中骨生成受到显著抑制。在不同的超滤分子大小级分中观察到不同程度的抑制活性，在<5 kDa范围内观察到非常显著的抑制作用。组织学观察表明，在所有浓度下均存在细胞、一些骨和/或新的纤维结缔组织，表明毒性不是一个因素。这些结果表明，牙龈卟啉单胞菌等牙周病原体可能不仅通过刺激吸收，还可能通过直接抑制骨形成，导致牙周病中的骨质流失。
