Research Updates: Relationship between Gingival Epithelial Intercellular Junctions and Periodontal Pathogenic Bacteria

Gingival epithelial barrier is the first line of defense of periodontal tissues against the invasion of pathogenic bacteria. The destruction of gingival epithelial barrier is closely related to the development of periodontal disease. Studies have shown that periodontal pathogenic bacteria and their inflammatory microenvironment can inhibit the expression of gingival epithelial junctional proteins via molecular mechanisms such as the downregulation of the expression of grainyhead-like protein family and the upregulation of the methylation level of gene promoter of epithelial connexin, and thus cause damage to the gingival epithelial barrier and the development of periodontitis. We herein reviewed the effects of bacteria and inflammatory factors induced by bacterial infection on gingival epithelial intercellular junctions and related mechanisms, and summarized the research progress on the relationship between gingival epithelial intercellular junctions and periodontal pathogenic bacteria in recent years. Most recent studies were focused on in vitro cytological experiments and animal models of infections caused by a single kind of bacterium. We have suggested that building gingival epithelial organoid model and combining multi-omics approaches with high resolution three-dimensional electron microscopy are expected to help pinpoint the key microorganisms and their most important virulence factors that trigger periodontal microecologcal imbalance and cause functional damage to the gingival epithelial barrier, to reveal the key molecular mechanisms involved in the maintenance and destruction of gingival epithelial barrier function, and to provide new perspectives on the pathogenesis and the clinical prevention and treatment of periodontitis.