Abstract

Endemic fluorosis is a serious problem in public health, affecting thousands of people. Abnormal proliferation and activation of osteoblasts in skeletal fluorosis lesions play a leading role and osteoblast proliferation is finely regulated by the cell cycle. There are a few reports on fluoride-induced DNA methylation. However, the role of DNA methylation of the cyclin/cyclin-dependent kinase (CDK)/cyclin-dependent kinase inhibitor (CKI) regulatory network in skeletal fluorosis has not been investigated. We used a population study and in vitro experiment to explore the relationship between the pathogenesis of skeletal fluorosis and methylation of Cyclin d1/CDK4/p21. The results showed a positive relationship between fluoride exposure and expression of Cyclin d1/CDK4, and a negative relationship between fluoride exposure and expression of P21. Hypermethylation of p21 was found in the fluoride-exposed population, and low expression of p21 attributed to promoter hypermethylation was confirmed in vitro. However, no changes in methylation levels of Cyclin d1 and CDK4 genes were observed in the population exposed to fluoride and NaF-treated osteoblasts. These results show that methylation of p21 gene has a significant impact on the proliferation of osteoblasts during the development of skeletal fluorosis. The present study was a first attempt to link the methylation of the Cyclin d1/CDK4/p21 regulatory network with osteoblast proliferation in skeletal fluorosis.

• Related Studies :

  • The relationship between Alu I polymorphisms in the calcitonin receptor gene and fluorosis endemic to Chongqing, China

    OBJECTIVE:  This study explored the association between an Alu I polymorphism at position 1,377 of the calcitonin receptor (CTR) gene and endemic fluorosis. SUBJECTS AND METHODS:  A case-control study of 321 participants was conducted in regions with high fluorosis rates (Wushan and Fengjie counties) and those without high fluorosis rates (Yubei

  • [Genetic markers of occupational susceptibility to fluorosis].

    To determine markers showing propensity to occupational fluorosis, the authors studied prevalence of ABO, Rh, MN, ABH and Lewis phenotypes, systemic rhesus haplotypes in 229 workers engaged into aluminum production. Propensity to occupational fluorosis was marked by P (+), O (ABO) phenotypes. P (-) phenotype appeared to be a marker

  • Downregulation of miR-4755-5p promotes fluoride-induced osteoblast activation via tageting Cyclin D1.

    Background Endemic fluorosis remains a major public health issue in many countries. Fluoride can cause abnormalities in osteoblast proliferation and activation, leading to skeletal fluorosis. However, its detailed molecular mechanism remains unclear. Based on a previous study, the aim of this study is to explore the role of miRNA in osteoblast

  • Fluoride's effects on the formation of teeth and bones, and the influence of genetics.

    Fluorides are present in the environment. Excessive systemic exposure to fluorides can lead to disturbances of bone homeostasis (skeletal fluorosis) and enamel development (dental/enamel fluorosis). The severity of dental fluorosis is also dependent upon fluoride dose and the timing and duration of fluoride exposure. Fluoride's actions on bone cells predominate

  • Fluoride induces hypomethylation of BMP2 and activates osteoblasts through the Wnt/B-catenin signaling pathway.

    Background: Skeletal fluorosis has become a public health issue in recent years as its serious impact on patients' life expectancy. Bone morphogenetic protein 2 (BMP2) plays a key role in promoting osteogenesis. However, the mechanism of BMP2-Wnt/B-catenin axis in skeletal fluorosis needs further exploration. Methods: The RT-qPCR

• Related FAN Content :

  • Factors which increase the risk for skeletal fluorosis

    The risk for developing skeletal fluorosis, and the course the disease will take, is not solely dependent on the dose of fluoride ingested. Indeed, people exposed to similar doses of fluoride may experience markedly different effects. While the wide range in individual response to fluoride is not yet fully understood, the following are some of the factors that are believed to play a role.

  • Fluoride's Effect on Osteoblasts (Bone-Forming Cells)

    As noted by the National Research Council, "[p]erhaps the single clearest effect of fluoride on the skeleton is its stimulation of osteoblast proliferation." (NRC 2006). Osteoblasts are bone-forming cells. "Stimulatory effects of fluoride on osteoblasts result in formation of osteoid, which subsequently undergoes mineralization." (Fisher RL, et al. 1989). If the new

  • Fluoride & Osteoarthritis

    While the osteoarthritic effects that occurred from fluoride exposure were once considered to be limited to those with skeletal fluorosis, recent research shows that fluoride can cause osteoarthritis in the absence of traditionally defined fluorosis. Conventional methods used for detecting skeletal fluorosis, therefore, will fail to detect the full range of people suffering from fluoride-induced osteoarthritis.

  • Skeletal Fluorosis & Individual Variability

    One of the common fallacies in the research on skeletal fluorosis is the notion that there is a uniform level of fluoride that is safe for everyone in the population. These "safety thresholds" have been expressed in terms of (a) bone fluoride content, (b) daily dose, (c) water fluoride level, (d) urinary fluoride level, and (e) blood fluoride level. The central fallacy with each of these alleged safety thresholds, however, is that they ignore the wide range of individual susceptibility in how people respond to toxic substances, including fluoride.

  • Skeletal Fluorosis: The Misdiagnosis Problem

    It is a virtual certainty that there are individuals in the general population unknowingly suffering from some form of skeletal fluorosis as a result of a doctor's failure to consider fluoride as a cause of their symptoms. Proof that this is the case can be found in the following case reports of skeletal fluorosis written by doctors in the U.S. and other western countries. As can be seen, a consistent feature of these reports is that fluorosis patients--even those with crippling skeletal fluorosis--are misdiagnosed for years by multiple teams of doctors who routinely fail to consider fluoride as a possible cause of their disease.