| China is one of the most severely fluorosis countries in the world. Almost all theprovinces have reported, Guizhou province has a high coal-fired incidence of endemicfluorosis. Regional dental fluorosis is a prominent symptoms of chronic fluorosis,generally believed that the pathogenesis of chronic endemic fluorosis is closely related toexcess fluoride destroys the normal metabolism of calcium and phosphorus, inhibit theactivity of certain enzymes, damage cell protoplasm and inhibition of collagen synthesis.There are few studies being about molecular and cell level, however, a lot of researchresults need to be comfirmed. We have established animal model of coal type dentalfluorosis of rats,we detected to new borned mouse tooth germ about the expression changesof organization of BMP-2(Bone Morphogenetic Protein2, BMP-2), informationtransmission G Protein oncogene ras P21expression product family, P53(tumor suppressorgene) and AP-1(transcription activitor) in1,3,5,7,14days respectively. A preliminaryexplore of coal-fired molecular pathogenesis of dental fluorosis will provide a theoreticalbasis for the study of coal-based dental fluorosis pathogenesis.Objective: To simulate coal-fired type fluorosis ward environment, establish coal typeanimals model of dental fluorosis and study the effects of fluoride on the expression ofBMP-2, P53, P21and AP-1in the rats germ. These factors to the coal-fired fluorosis isdiscussed.Methods:(1) Replication of an animal model:363-week-old SD rats, cleaning level,male and female ratio2:1, were randomly divided into experimental group. Theexperimental group was placed in a simulated coal-burning endemic fluorosis indoorenvironment and feed with fluoride concentration of F-40mg/kg foods while the normal group with ordinary conditions. Both groups were drinking deionized water.(2) Testing content and methods:weighing the rat body weight, took photos of the teeth toobserve the changes of rat incisor. Eight weeks of the experimental group and controlgroup respectively according to the proportion of male and female rats2:1or cage, whenthe offspring were borned,using the microscope to get the fetal rats’ labial and root of themandibular incisors’ organizations at1,3,5,7,14day, using pathological to localize andseparation of tooth germ. Using Immunohistochemistry staining observation of BMP-2andP21proteins in tooth germ cell development in the process of localization. The expressionof BMP-2, P21, P53, AP-1in the germ cell were detected by fluorescence quantitative PCR.Results:(1) This experiment successfully established more credible animals dentalfluorosis of SD rats.The experimental group was observed the dental fluorosis and theillness aggravating gradually in4weeks and the fluorine spot tooth form basically fixedafter8weeks.(2) In1,3,5,7,14days, excessive fluorine has inhibition effect to the expression ofBMP-2gene. In1,3,5,7day,excessive fluorine has inhibitory effect on the expression ofP21gene. C-Fos and P53gene were inhibited by excessive fluorine contained in1,3days,but increased in5,7,14days. C-Jun genes expressed in1,3days will be affected byexcessive fluorine contained, and on day5,7increased expression(p<0.05).Conclusion: The coal-fired type fluoride environment on the growth and development ofrats and their offspring produced a certain influence, excessive fluoride may be affectedtooth germ development and the relevant genes of protein synthesis in the fetal rats’ toothgerm cells and the tooth germ developments in further, all of these may lead to theemergence of symptom of dental fluorosis consequently. |
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