Low Level Fluoride Stimulates Epithelial-Mesenchymal Interaction in Oral Mucosa

Abstract

Oral mucosa consists of the superficial epithelium and the underlying lamina propria, and it functions as a barrier against exogenous substances. In development, interactions of stem/progenitor cells of the epithelium and mesenchyme are crucial to the morphogenesis of oral mucosa. Our previous work in low level fluorideinduced cell motility of epithelial cells has yielded important clues for periodontal physiology. This study focuses on a working concept of low level fluoride to provide a conducive oral environment for pivotal epithelialmesenchymal interactions. Cultured human primary gingival epithelial cells treated with 50 μM NaF were investigated by DNA microarray. Quantitative real-time PCR and an in vivo experimental rat skin wound model were employed to confirm the findings obtained with the microarray analysis. Microarray data revealed that low level fluoride-treated human gingival epithelial cells elevated various biological processes. The key proliferation markers, FGF2 and FGF7, and mesenchymal marker, Twist1, expression was up-regulated and quantitative real-time PCR confirmed this observation. Our in vivo study revealed that low concentration of NaF increased FGF2, FGF7, and Twist1 protein expression in fluoride-treated skin wound tissues compared with controls. These results provide new information on low level fluoride-induced epithelial-mesenchymal interactions and may thus aid in the understanding of oral mucosa development.

Anti‐inflammatory effects of bamboo salt and sodium fluoride in human gingival fibroblasts–An in vitro study

“…The effect of fluoride on cellular activity may be biphasic in that low concentrations provide increased osteoprogenitor cell number, whereas high concentrations are associated with histological findings of osteoblast inactivity [34]. In the present study, the use of BS and NaF to treat inflammation exhibited favorable results in agreement with previous studies [35,36]. The inhibitory effect of BS and NaF on IL‐1β, TNF‐α, and IL‐8 cytokine production was observed in IL‐1β‐treated fibroblast cells in vitro .…”

The Role of Low-Level Sodium Fluoride in Periodontal Inflammation

“…In this study, the similar responses in the PDL suggests that the effector, fluoride, is a trigger that elicits a PDL specific reaction. Although the specific mechanism of action has not been elucidated, our previous studies and the in vitro and in vivo data reported here suggest that NaF acts directly on oral cells 27,44,45) .…”

Treatment with low‐level sodium fluoride on wound healing and the osteogenic differentiation of bone marrow mesenchymal stem cells

“…The cells were then treated with serum‐free medium supplemented with NaF at concentrations of 0, 50, 500, and 5 mM. Cell proliferation was assessed by the MTS assay at 12, 24, and 48 hours after NaF supplementation as per the protocol of a previously published study . Cell Titer 96® Aqueous One Solution Reagent (Promega) was added directly to each well, incubated for 2 hours, and the absorbance at 490 nm was then measured using a microplate reader (Bio‐Rad).…”

“…RNA extraction was done in BMMSCs cultured in osteoblastic induction medium with and without 50 µM NaF for 21 days as per the previously published protocol . In brief, 1 μg total extracted RNA (RNeasy Mini Kit; Qiagen KK) was reverse‐transcribed using a High‐Capacity cDNA Archive Kit (Applied Biosystems).…”

“…In recent years, great advances have been made in elucidating the effects of treating cells with sodium fluoride (NaF) . Those effects have been found to be concentration‐dependent with micromolar levels (low level) of fluoride increasing cell proliferation, while millimolar levels (high concentration) induce stress in the endoplasmic reticulum, apoptosis, and DNA fragmentation by the caspase‐mediated pathway in enamel organ/epithelial‐derived cell lines . Recently, a novel low‐level NaF application has emerged as an innovative, effective, and affordable adjunct for wound healing .…”