Micro RNA expression profile of human periodontal ligament cells under the influence of Porphyromonas gingivalis LPS

Periodontitis is a chronic inflammatory disease which is caused by bacterial infection and leads to the destruction of periodontal tissues and resorption of alveolar bone. Thus, special attention should be paid to the mechanism under lipopolysaccharide ( LPS )‐induced periodontitis because LPS is the major cause of periodontitis. However, to date, mi RNA expression in the LPS ‐induced periodontitis has not been well characterized. In this study, we investigated mi RNA expression patterns in LPS ‐treated periodontal ligament cells (PDLC s). Through mi RNA array and differential analysis, 22 up‐regulated mi RNA s and 28 down‐regulated mi RNA s in LPS ‐treated PDLC s were identified. Seven randomly selected up‐regulated (miR‐21‐5p, 498, 548a‐5p) and down‐regulated (miR‐495‐3p, 539‐5p, 34c‐3p and 7a‐2‐3p) mi RNA s were examined by qRT ‐ PCR , and the results proved the accuracy of the mi RNA array. Moreover, targets of these deregulated mi RNA s were analysed using the mi RW alk database. Database for Annotation, Visualization and Integration Discovery software were performed to analyse the Gene Ontology and Kyoto Encyclopaedia of Genes and Genomes pathway of differential expression mi RNA s, and the results shown that Toll‐like receptor signalling pathway, cAMP signalling pathway, transforming growth factor‐beta signalling pathway, mitogen‐activated protein kinase ( MAPK ) signalling pathway and other pathways were involved in the molecular mechanisms underlying LPS ‐induced periodontitis. In conclusion, this study provides clues for enhancing our understanding of the mechanisms and roles of mi RNA s as key regulators of LPS ‐induced periodontitis.