Differential activation of NF-κB and gene expression in oral epithelial cells by periodontal pathogens

Abstract

SummaryTo investigate the molecular effects of the periodontopathogens Fusobacterium nucleatum (FN) and Porphyromonas gingivalis (PG) on the oral epithelium, the H400 oral epithelial cell line was cultured in the presence of non-viable bacteria. Following confirmation of the presence of transcripts for the bacterial pattern recognition receptors in H400 cells, Toll-like receptors -2, -4 and -9, and components of the NF-kB signalling pathway, immunocytochemical analyses were performed showing that NF-kB was activated within 1 h of exposure to both periodontopathogens. A significantly greater number of NF-kB nuclear translocations were apparent following H400 cell exposure to FN as compared with PG. Gene expression analyses indicated that transcripts known to be regulated by the NF-kB pathway, including cytokines/chemokines TNF-a, IL-1b, IL-8, MCP-1/CCL2 and GM-CSF, were up-regulated following 4 and 24 h of exposure to both periodontopathogens. In addition, H400 periodontopathogen exposure resulted in differential regulation of transcripts for several cytokeratin gene family members. Consistent with the immunocytochemical data, microarray results indicated that FN induced a greater number of gene expression changes than PG following 24 h of exposure, 609 and 409 genes, respectively. Ninety-one genes were commonly differentially expressed by both periodontopathogens and represented biological processes commonly associated with periodontitis. Gene expression analyses by reserve transcriptase-polymerase chain reaction (RT-PCR) of molecules identified from the microarray data sets, including Heme oxygenase-1, lysyl oxidase, SOD2, CCL20 and calprotectin components, confirmed their differential expression profiles induced by the two periodontopathogens. FN and PG have clearly different molecular effects on oral epithelial cells, potentially highlighting the importance of the composition of the plaque biofilm in periodontitis pathogenesis.

The NLR Adaptor ASC/PYCARD Regulates DUSP10, Mitogen-activated Protein Kinase (MAPK), and Chemokine Induction Independent of the Inflammasome

“…The finding that Pg activates NF-B-and TNF-related signaling is consistent with other microarray studies of Pg infection (28,34). Our further assessment of ASC-modulated genes revealed several chemokines that are ASC-dependent.…”

“…Consistently, TNF-␣ pathways are known to contribute to Pg-associated pathogenesis during periodontitis (34,35). The second interactome ( Fig.…”

Myricetin blocks lipoteichoic acid-induced COX-2 expression in human gingival fibroblasts

“…It associates with TLR-2 and is responsible for septic shock via its promotion of the expression of proinflammatory cytokines. The premise that periodontal pathogens or their components are associated with the development of periodontal disease has spurred extensive research into ways to control the disease by regulating activated intracellular signaling pathways [16][17][18][19]. There is growing evidence that plant-derived foods and beverages contribute to the healthy development and status of blood vessels and connective tissues.…”

Contemporary perspective on plaque control

“…7,8 The precise biological mechanisms involved in this 'cross-talk' are still being determined, but pathogenic and non-pathogenic bacteria may initiate different intracellular signalling pathways and innate immune responses in epithelial cells. 9 As at other body sites, the resident oral microflora displays 'colonisation resistance' and prevents the establishment in the mouth of the many exogenous microorganisms we come into contact with on a daily basis. This is because the natural oral microflora is better adapted at attachment to oral surfaces, is more efficient at metabolising the available nutrients for growth and can produce inhibitory factors and create hostile environments that restrict colonisation by potential microbial invaders.…”