Hematogenous apoptotic mechanism in salivary glands in chronic periodontitis.

Abstract

OBJECTIVE:

The aim of the study is to investigate the apoptotic mechanism in salivary glands in the rat experimental periodontitis model.

DESIGN:

A rat periodontitis model was prepared by using a ligature around the second upper molar. In the salivary (parotid and submandibular) glands and blood samples, putative apoptotic factors and pathway molecules were investigated in vivo and in vitro.

RESULTS:

Four weeks of ligation (chronic periodontitis) demonstrated significant apoptotic atrophy of the salivary gland, but one week of ligation (initial periodontitis) did not. In the blood plasma, tumor necrosis factor-α (TNF-α) was increased in the periodontitis model, but interleukin-1β and -6 were not. TNF-α receptor type 1, which has an intracellular apoptotic pathway, was expressed in the salivary glands of rats. Western blot analysis of cultured rat primary salivary gland cells demonstrated that TNF-α induced cleavage of poly (ADP-ribose) polymerase (PARP) and caspase-3 in a dose-dependent manner, indicating apoptosis induction. Additionally, we found increment of circulating lymphocytes in the model. Expression of mRNA and immunoreactive cells for the B lymphocyte marker CD19 were increased in the salivary gland in the model. Western blotting showed that coculture with extracted B cells from the periodontitis model increased cleaved PARP in salivary gland cells.

CONCLUSIONS:

Chronic periodontitis status leads to an increase in circulating TNF-α and B lymphocyte infiltration, resulting in apoptotic atrophy of the salivary gland as a periodontitis-induced systemic response.

• Authors: T Shikayama, J Fujita-Yoshigaki, M Sago-Ito, M Nakamura-Kiyama, M Naniwa, S Hitomi, I Ujihara, S Kataoka, N Yada, W Ariyoshi, M Usui, K Nakashima, K Ono
• Journal: Archives of oral biology (Arch Oral Biol) Vol. 117 Pg. 104775 (Sep 2020) ISSN: 1879-1506 [Electronic] England
• PMID: 32512258 (Publication Type: Journal Article)
• Copyright: Copyright © 2020 Elsevier Ltd. All rights reserved.

Chemical References

• Tumor Necrosis Factor-alpha

Topics

• Animals
• Apoptosis
• B-Lymphocytes (cytology)
• Chronic Periodontitis (pathology)
• Rats
• Salivary Glands (pathology)
• Tumor Necrosis Factor-alpha (blood)