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Porphyromonas gingivalis Lipopolysaccharide Induces a Pro-inflammatory Human Gingival Fibroblast Phenotype

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Abstract

Human gingival fibroblasts (HGFs) are the major constituents of the gingival tissues responsible for the synthesis and degradation of the connective tissue while actively participating in immune reactions and inflammation. The aim of this study was to test the impact of lipopolysaccharide (LPS) from Porphyromonas gingivalis (P. gingivalis) on human gingival fibroblasts. Human gingival fibroblasts were treated with different P. gingivalis LPS concentrations. Cell survival rate was evaluated with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) after 24 h. Cell proliferation was determined by counting cells on days 3 and 12. Expression of matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), and pro-inflammatory cytokine transcripts in HGFs was determined by quantitative PCR (Q-PCR) analysis on days 3 and 8. P. gingivalis LPS decreased cell proliferation on day 3 (p < 0.05) compared to the control group without significantly impacting the cell survival (p > 0.05).The experiments showed that P. gingivalis LPS dose-dependently and differentially modulated the expression of MMP-1, 2, and 3 and TIMP-1 and 2 on days 3 and 8. TIMP-1 expression was significantly induced in P. gingivalis LPS-treated cells while TIMP-2 was increased in response to 10 and 30 ng/ml of LPS on day 3. P. gingivalis LPS induced up-regulation of MMP-1/TIMP-1 ratio on day 3 and increased MMP-2/TIMP-2 ratio on day 8 dose-dependently. Expression of interleukin (IL)-6 and IL-8 was stimulated at higher concentrations (1000 and 3000 ng/ml) of LPS. These findings demonstrate that P. gingivalis LPS suppresses cell proliferation and leads to increased pro-inflammatory changes in HGFs, suggesting that P. gingivalis LPS-induced modification of phenotypic and inflammatory characteristics in HGF could potentially be a pathogenic mechanism underlying the tissue destruction.

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Acknowledgments

This study was performed at the Selcuk University Faculty of Dentistry, Research Center and was supported by the Research Fund, Selcuk University (BAP/08201022).

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Authors and Affiliations

  1. Research Center of Faculty of Dentistry, Selcuk University, Konya, Turkey

    S. Buket Bozkurt

  2. Faculty of Dentistry, Department of Periodontology, Selcuk University, Konya, Turkey

    Sema S. Hakki

  3. Faculty of Agriculture, Department of Soil Science & Plant Nutrition, Selcuk University, Konya, Turkey

    Erdogan E. Hakki

  4. Faculty of Science, Department of Biology, Selcuk University, Konya, Turkey

    Yusuf Durak

  5. Department of Periodontology, The Forsyth Institute, Boston, MA, USA

    Alpdogan Kantarci

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Bozkurt, S.B., Hakki, S.S., Hakki, E.E. et al. Porphyromonas gingivalis Lipopolysaccharide Induces a Pro-inflammatory Human Gingival Fibroblast Phenotype. Inflammation 40, 144–153 (2017). https://doi.org/10.1007/s10753-016-0463-7

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