Vitamin D maintains E-cadherin intercellular junctions by downregulating MMP-9 production in human gingival keratinocytes treated by TNF-α
10.5051/jpis.2019.49.5.270
- Author:
Changseok OH
1
;
Hyun Jung KIM
;
Hyun Man KIM
Author Information
1. Laboratory for the Study of Molecular Biointerfaces, Department of Oral Histology and Developmental Biology, Program of Cell and Developmental Biology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea. hyunmkim@snu.ac.kr
- Publication Type:Original Article
- Keywords:
Cadherins;
Keratinocytes;
Matrix metalloproteinase 9;
NF-kappa B;
Tumor necrosis factor-alpha;
Vitamin D
- MeSH:
Bays;
Blotting, Western;
Cadherins;
Cell Line;
Down-Regulation;
Epithelial Attachment;
Epithelium;
Gelatin;
Humans;
Intercellular Junctions;
Keratinocytes;
Matrix Metalloproteinase 9;
Matrix Metalloproteinases;
NF-kappa B;
Periodontium;
Receptors, Calcitriol;
Tumor Necrosis Factor-alpha;
Up-Regulation;
Vitamin D;
Vitamins
- From:Journal of Periodontal & Implant Science
2019;49(5):270-286
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: Despite the well-known anti-inflammatory effects of vitamin D in periodontal health, its mechanism has not been fully elucidated. In the present study, the effect of vitamin D on strengthening E-cadherin junctions (ECJs) was explored in human gingival keratinocytes (HGKs). ECJs are the major type of intercellular junction within the junctional epithelium, where loose intercellular junctions develop and microbial invasion primarily occurs. METHODS: HOK-16B cells, an immortalized normal human gingival cell line, were used for the study. To mimic the inflammatory environment, cells were treated with tumor necrosis factor-alpha (TNF-α). Matrix metalloproteinases (MMPs) in the culture medium were assessed by an MMP antibody microarray and gelatin zymography. The expression of various molecules was investigated using western blotting. The extent of ECJ development was evaluated by comparing the average relative extent of the ECJs around the periphery of each cell after immunocytochemical E-cadherin staining. Vitamin D receptor (VDR) expression was examined via immunohistochemical analysis. RESULTS: TNF-α downregulated the development of the ECJs of the HGKs. Dissociation of the ECJs by TNF-α was accompanied by the upregulation of MMP-9 production and suppressed by a specific MMP-9 inhibitor, Bay 11-7082. Exogenous MMP-9 decreased the development of ECJs. Vitamin D reduced the production of MMP-9 and attenuated the breakdown of ECJs in the HGKs treated with TNF-α. In addition, vitamin D downregulated TNF-α-induced nuclear factor kappa B (NF-κB) signaling in the HGKs. VDR was expressed in the gingival epithelium, including the junctional epithelium. CONCLUSIONS: These results suggest that vitamin D may avert TNF-α-induced downregulation of the development of ECJs in HGKs by decreasing the production of MMP-9, which was upregulated by TNF-α. Vitamin D may reinforce ECJs by downregulating NF-κB signaling, which is upregulated by TNF-α. Strengthening the epithelial barrier may be a way for vitamin D to protect the periodontium from bacterial invasion.
