Abstract

Enamel fluorosis is characterized by hypomineralization, and forkhead box O1 (Foxo1) is essential for mouse enamel biomineralization. This study investigated the effect of fluoride on Foxo1 expression and its implications for enamel fluorosis. Mandibular incisors were extracted from Sprague Dawley rats treated for 3 months with water containing 0, 50, or 100 p.p.m. F^– . Immunohistochemistry was used to localize and quantify FOXO1 expression in dental epithelial layer cells of the incisors. The effect of fluoride on expression of Foxo1, kallikrein-4 (Klk4), and amelotin (Amtn) mRNAs was analyzed by real-time RT-PCR, and western blotting was used to measure total and nuclear FOXO1 protein levels in mature dental epithelial cells. The results revealed that nuclear FOXO1 was mainly localized in the transition and the mature ameloblasts and exhibited weaker expression in the rats exposed to fluoride. In addition to the reduced levels of Foxo1, Klk4, and AmtnmRNAs, the protein levels of total and nuclearFOXO1 were decreased in the mature dental epithelial cells exposed to fluoride. Thus, excessive fluoride may have an effect on the expression levels of Foxo1 in dental epithelial cells and thereby affect hypomineralization of the enamel during fluorosis.

• Related Studies :

  • Fluoride Alters Klk4 Expression in Maturation Ameloblasts through Androgen and Progesterone Receptor Signaling.

    Fluorosed maturation stage enamel is hypomineralized in part due to a delay in the removal of matrix proteins to inhibit final crystal growth. The delay in protein removal is likely related to reduced expression of kallikrein-related peptidase 4 (KLK4), resulting in a reduced matrix proteinase activity that found in fluorosed

  • Effects of fluoride on the expression of beclin1 and mTOR in ameloblasts

    Exposure to high levels of fluoride (F-) can result in dental fluorosis in different individuals, but the mechanism of dental fluorosis remains unclear. Autophagy is a highly conserved intracellular digestion process that degrades damaged organelles and protein aggregates. This study examined the effect of sodium fluoride (NaF) on the expression

  • [In vivo and in vitro experimental study on the effect of fluoride-induced autophagy in rat HAT-7 cell line].

    PURPOSE:  To study the effect of fluoride on autophagy in rat ameloblasts both in vitro and in vivo. METHODS:  Logarithmic-phase HAT-7 cells were cultured in different concentrations of fluoride for 48h. Transmission electron microscopy (TEM) was used to detect autophagosomes. Western blot and RT-qPCR were carried out to examine the expression

  • JNK Signaling Pathway Mediates Fluoride-Induced Upregulation of CK1a during Enamel Formation.

    Fluorosis is a defect in the enamel mineral content caused by excessive fluoride intake during amelogenesis; the interaction of various factors in the development and progression of fluorosis has not been defined. Casein kinase 1a (CK1a) is constitutively active in cells and is involved in diverse cellular processes; however, its

  • Fluoride exposure alters Ca2+ signaling and mitochondrial function in enamel cells.

    Fluoride ions are highly reactive, and their incorporation in forming dental enamel at low concentrations promotes mineralization. In contrast, excessive fluoride intake causes dental fluorosis, visually recognizable enamel defects that can increase the risk of caries. To investigate the molecular bases of dental fluorosis, we analyzed the effects of fluoride

• Related FAN Content :

  • Mechanisms by Which Fluoride Causes Dental Fluorosis Remain Unknown

    When it comes to how fluoride impacts human health, no tissue in the body has been studied more than the teeth. Yet, despite over 50 years of research, the mechanism by which fluoride causes dental fluorosis (a hypo-mineralization of the enamel that results in significant staining of the teeth) is not

  • Dental Fluorosis Is a "Hypo-mineralization" of Enamel

    Teeth with fluorosis have an increase in porosity in the subsurface enamel ("hypomineralization"). The increased porosity of enamel found in fluorosis is a result of a fluoride-induced impairment in the clearance of proteins (amelogenins) from the developing teeth. Despite over 50 years of research, the exact mechanism by which fluoride impairs amelogin

  • "Mild" Dental Fluorosis: Perceptions & Psychological Impact

    The vast majority of research has found that patients, parents, and the general public alike view mild fluorosis (TF score 3) as a significant blemish of the teeth, one that is likely to embarrass the affected child to a degree that cosmetic treatment would be warranted.

  • Racial Disparities in Dental Fluorosis

    In 2005, the Centers for Disease Control published the results of a national survey of dental fluorosis conducted between 1999 and 2002. According to the CDC, black children in the United States have significantly higher rates of dental fluorosis than either white or Hispanic children. This was not the first time that black children were found to suffer higher rates of dental fluorosis. At least five other studies -- dating as far back as the 1960s -- have found black children in the United States are disproportionately impacted by dental fluorosis.

  • Diagnostic Criteria for Dental Fluorosis: The TSIF ("Total Surface Index of Fluorosis")

    The traditional criteria (the "Dean Index") for diagnosing dental fluorosis was developed in the first half of the 20th century by H. Trendley Dean. While the Dean Index is still widely used in surveys of fluorosis -- including the CDC's national surveys of fluorosis in the United States -- dental