Porphyromonas gingivalis lipopolysaccharides regulate functions of bone marrow mesenchymal stem cells

Objectives: Periodontitis is one of the most widespread inflammatory diseases; it causes tooth loss and is also associated with a variety of systemic diseases. Mesenchymal stem cells (MSCs) have been used to treat periodontitis. However, it is unknown whether bacterial toxins in the periodontal environment affect MSC-mediated periodontal regeneration. Porphyromonas gingivalis lipopolysaccharides (Pg-LPS) are key toxins for development of periodontitis. The purpose of the present study was to investigate effects of P. gingivalis LPS on biological properties of MSCs. Materials and methods: Mesenchymal stem cells from bone marrow (BMMSCs) were treated with different concentrations of P. gingivalis LPS (0.1-10 μg/ml), then its effects were evaluated on biological properties of BMMSCs including proliferation, apoptosis, osteogenic differentiation and capacities to inhibit activated T cells. Results: Low concentration of P. gingivalis LPS (0.1 μg/ml) accelerated MSC proliferation, osteogenic differentiation and capacities to inhibit activated T cells via up-regulation of nitric oxide. However, high concentration of P. gingivalis LPS (10 μg/ml) reduced MSC proliferation, osteogenic differentiation and capacities to inhibit activated T cells. Conclusions: Mesenchymal stem cells were functionally different following exposure to P. gingivalis LPS at the investigated concentrations. These findings suggest that MSC-mediated periodontal regeneration may be regulated by P. gingivalis LPS.