Effect Of MT01 On Proliferation, Cell Cycle And Apoptosis Of Osteoblasts MG63 Invaded By Porphyromonas Gingivalis

Periodontitis is regarded as a kind of chronic infectious diseases due to unbalanced between plaque microbes and host immune system, the cause of the alveolar bone resorption has become the main reason for the loss of adult teeth. The harm not only affects chewing, pronunciation,the basic function such as eating, but also severely affected physical and mental health and the quality of life of patients.As an important periodontal pathogen, Porphyromonas gingivalis’ virulence factor can cause periodontal tissue destruction by acting directly involved in periodontal support tissues or indirectly causing the host immune inflammatory response, then inhibiting osteoblast differentiation and bone formation, resulting in alveolar bone absorption, causing loss of teeth.specific sequence oligodeoxynucleotide MT01 is a kind of inhibitory oligodeoxynucleotide which designed based on the sequence of human mitochondrial DNA without CG sequence motif. MT01 can target and block Toll-like receptors 9 activation, and reduce the inflammation injury of tissues,thus inhibiting the excessive and harmful immune response causing by pathogen infection.Animal experiments have confirmed that MT01 can inhibit alveolar bone resorption of rat periodontitis model, at the same time, in vitro studies have shown that MT01 play an importantrole in the process of osteoblast activation and promote bone marrow mesenchymal stem cells to differentiate into osteoblast.Based on these researches, we speculate that MT01 may have a greate influence on periodontitis inflammatory immune response. Therefore, we want to detect whether MT01 can effect the biological properties of osteoblasts invaded by Porphyromonas gingivalis through testing the proliferation, cell cycle and apoptosis. These ideas could be the experimental basis of MT01 may be regulate periodontal immune inflammation response.Methods:MG63 were recoveried and incubated with MT01, Cp G ODN,metronidazole(MNZ), gentamicin(GEN) for 3 hours, then Porphyromonas gingivalis(MOI=100:1) was added subsequently and cocultured for another 24 h and 48 h. Cells with PBS were used as blank group and celles with Pg used as negative controls. There were six experimental groups: PBS group 、Pg group 、MT01+Pg group、Cp G ODN+Pg group 、 MNZ+Pg group 、 GEN+Pg group. The ability of proliferation was measured by methyl thiazolyl tetrazolium assay(MTT),and the percentage of apoptosis and cell cycle were examined by flow cytometry.Result:The proliferation increased significantly in the MT01+Porphyromonas gingivalis group compared to the blank group(P<0.05);the ratio of cells was lower at G1 phase and higher at S phase in the MT01+ Porphyromonas gingivalis group compared to the Porphyromonas gingivalis group(P<0.05); the early cell apoptosis in the MT01+ Porphyromonas gingivalis group was significantly decreased compared to the Porphyromonas gingivalis group(P<0.05).Conclusion:MT01 can promote the proliferation, reduce the ratio of G1 phase,increase the ratio of S phase and inhibit the early apoptosis of osteoblasts invaded by Porphyromonas gingivalis.