Localization and expression pattern of amelotin, odontogenic ameloblast-associated protein and follicular dendritic cell-secreted protein in the junctional epithelium of inflamed gingiva

Abstract

The purpose of this study is to elucidate the localization of amelotin (AMTN), odontogenic ameloblast-associated protein (ODAM) and follicular dendritic cell-secreted protein (FDC-SP) at the junctional epithelium (JE) in Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans infected mice and inflamed and non-inflamed human gingiva. We performed immunostaining to determine the localization and expression pattern of AMTN, ODAM and FDC-SP. AMTN, ODAM and FDC-SP in A. actinomycetemcomitans infected mice did not change dramatically compared with non-infected mice. AMTN and FDC-SP expressions were observed stronger in P. gingivalis infected mice at early stage. However, at the following stage, the coronal part of the AMTN expression disappeared from the JE, and FDC-SP expression decreased due to severe inflammation by P. gingivalis. ODAM expressed internal and external basal lamina, and the expression increased not only at early stage but also at the following stage in the inflammatory JE induced by P. gingivalis. In the human gingival tissues, AMTN was detected at the surface of the sulcular epithelium and JE in the non-inflamed and inflamed gingiva, and the localization did not change the process of inflammation. ODAM and FDC-SP were more widely detected at the sulcular epithelium and JE in the non-inflamed gingiva. In the inflamed gingiva, localization of ODAM and FDC-SP was spread into the gingival epithelium, compared to AMTN. These studies demonstrated that the expression pattern of AMTN, ODAM and FDC-SP at the JE were changed during inflammation process and these three proteins might play an important role in the resistance to inflammation.

Selective bacterial degradation of the extracellular matrix attaching the gingiva to the tooth

“…Similarly to ODAM, numerous fragments of Lm332 are also found in the crevicular fluid of patients suffering from periodontal diseases (40). Immunolabeling for AMTN in the JE has been reported to decrease over time in P. gingivalis-infected mice (41). These outcomes are consistent with their high degradative susceptibility to enzymes and bacteria observed in the present study.…”

Transcriptional regulation of human amelotin gene by interleukin‐1β

“…transcription in gingival epithelial cells [24]. AMTN protein expression in the JE was increased in Porphyromonas gingivalis-infected periodontitis model mice at early stage, whereas AMTN protein levels were suppressed at later stages [34]. These data suggest that the increased gene expression of AMTN by inflammatory cytokines might have some kind of physiological role of AMTN in the JE.…”

Tumor necrosis factor‐α regulates human follicular dendritic cell‐secreted protein gene transcription in gingival epithelial cells

“…Statherin inhibits precipitation from supersaturated calcium phosphate solutions and stabilizes supersaturated saliva (Schlesinger & Hay, ). FDC‐SP expresses in the periodontal ligament and JE, and prevents mineralization of periodontal ligament and adsorbs onto the surface of enamel and cementum adjacent to JE (Nakayama et al., ; Shinomura et al., ). FDC‐SP in the JE was completely lost 3 hr after the treatment with E. coli LPS in the upper molars of rats, but the immunoreactivity was detected again after 3 days (Oshiro et al., ).…”

“…In the human gingiva, FDC‐SP was widely detected at the sulcular epithelium and JE in the noninflamed gingiva. In the inflamed gingiva, localization of FDC‐SP was spread into the gingival epithelium (Nakayama et al., ). Thus, to elucidate the function of FDC‐SP in the inflamed gingiva, we used TNF‐α on FDC‐SP gene transcription in gingival epithelium cells.…”