Decreased expression of E‐cadherin by Porphyromonas gingivalis‐lipopolysaccharide attenuates epithelial barrier function. (26th March 2016)

• Record Type: Journal Article
• Authors: Abe‐Yutori, M.; Chikazawa, T.; Shibasaki, K.; Murakami, S.
• Is Part Of: Journal of periodontal research. Volume 52:Number 1(2017)
• Page Start: 42
• Page End: 50
• Publication Date: 2016-03-26
• Subjects: E‐cadherin -- epithelial barrier -- gingival epithelium -- lipopolysaccharide -- Porphyromonas gingivalis -- reactive oxygen species; Periodontics -- Periodicals; 617.632
• DOI: 10.1111/jre.12367
• Languages: English
• ISSNs: 0022-3484

Abstract

Abstract : Background and Objective: The gingival epithelium is a first line of defense against bacterial challenge. E‐cadherin (E‐cad) plays an important role in cell–cell adhesion as a barrier in the epithelium. Recently, a decrease in the expression of E‐cad has been observed in inflamed gingival tissue. The aims of this study were to clarify the changes in E‐cad expression and barrier function in human gingival epithelial cells stimulated with Porphyromonas gingivalis ‐lipopolysaccharide ( P. gingivalis ‐LPS) and to evaluate the influence of these changes on the inflammatory reaction. Furthermore, to clarify the mechanism of the E‐cad changes induced by P. gingivalis ‐LPS, we focused on reactive oxygen species (ROS) that are reported to induce a decrease in E‐cad expression. Material and Methods: Human gingival epithelial cells were incubated in Humedia‐KG2 in the presence or absence of P. gingivalis ‐LPS and antioxidants to analyze ROS involvement in P. gingivalis ‐LPS‐induced E‐cad changes. E‐cad protein expression was analyzed by immunofluorescence staining. To investigate barrier function and inflammatory changes, we performed transport and cytokine assays using gingival epithelial cells and macrophages co‐culture model in transwell plates. Medium containing 10 μg/mL P. gingivalis ‐LPS (transport substance) was added to the upper compartment, which harvested gingival epithelial cells, and medium without P. gingivalis ‐LPS was added to the lower compartment, which harvested macrophages. In the transport assay, P. gingivalis ‐LPS penetration was analyzed using the Limulus amebocyte lysate test. In the cytokine assay, we examined the change in tumor necrosis factor‐α (TNF‐α) production from the macrophages in the lower compartment using enzyme‐linked immunosorbent assay. Results: Expression of E‐cad in human gingival epithelial cells was decreased by P. gingivalis ‐LPS, and the decrease in E‐cad accelerated the penetration of P. gingivalis ‐LPS through the monolayer. In addition, the concentration of TNF‐α was higher under the E‐cad reduced monolayer. Antioxidants, particularly vitamin E andl ‐ascorbic acid 2‐phosphate magnesium salt, inhibited the decrease in E‐cad expression, penetration of P. gingivalis ‐LPS and increase in TNF‐α. Conclusion: These results suggest that the decrease in E‐cad caused by P. gingivalis‐ LPS leads to destruction of the epithelial barrier function in human gingival epithelial cells, and finally accelerates the inflammatory reaction under the barrier. Antioxidants, particularly vitamin E andl ‐ascorbic acid 2‐phosphate magnesium salt, may restore the impaired function by scavenging ROS, which are related to the decrease in E‐cad expression by P. gingivalis‐ LPS.