Effect of Sonicated Extracts of P. gingivalis 2561 on PDLSCs

Porphyromonas gingivalis has been implicated as an important etiological agent in the initiation and progression of periodontal disease. However, the effects of P. gingivalis on PDLSCs, which is the potential cells to repair or reconstruct periodontal tissues following destruction by periodontal diseases, are not known. Objectives: This study was undertaken to determine the effects of sonicated extracts of P. gingivalis on differentiation of PDLSCs. Methods: Cultures of P. gingivalis 2561 were grown under standard anaerobic culture conditions. The bacterial inocula were harvested, and following centrifugation, sonicated bacterial extracts were prepared from the bacterial pellet. These were added in various concentrations to the PDLSCs cultures. Expression of osteonectin (ON), MMP-9 and VEGF were measured on 6-day-old cultures at protein level. Results: Compared with controls devoid of bacterial sonicated extracts, ON was down-regulated in cultures treated with either 10 ìg/ml or 100 ìg/ml P. gingivalis sonicated extracts and up-regulated with 1ìg/ml P. gingivalis sonicated extracts. VEGF was up-regulated in cultures treated with either 1 ìg/ml or 10 ìg/ml P. gingivalis sonicated extracts but down-regulated with 100 ìg/ml P. gingivalis sonicated extracts. MMP-9 was up-regulated in cultures treated with P. gingivalis sonicated extracts. Conclusions: These results suggested that periodontal pathogens such as P. gingivalis might contribute to destruction in periodontal diseases by inhibiting the differentiation and blood vessel reconstruction of PDLSCs as well as by speeding the degradation of extracellular matrix.