Charone Senda, De Lima Leite Aline, Peres-Buzalaf Camila, Silva Fernandes Mileni, Ferreira de Almeida Lucas, Zardin Graeff Marcia Sirlene, Cardoso de Oliveira Rodrigo, Campanelli Ana Paula, Groisman Sonia, Whitford Gary Milton, Everett Eric T, Buzalaf Marília Afonso Rabelo
Department of Biological Sciences, Bauru Dental School, University of Sx00E3;o Paulo, Bauru, Brazil.
Caries Res. 2016;50(1):24-31. doi: 10.1159/000442301. Epub 2016 Jan 28.
The mechanisms by which excessive ingestion of fluoride (F) during amelogenesis leads to dental fluorosis (DF) are still not precisely known. Inbred strains of mice vary in their susceptibility to develop DF, and therefore permit the investigation of underlying molecular events influencing DF severity. We employed a proteomic approach to characterize and evaluate changes in protein expression from secretory-stage and maturation-stage enamel in 2 strains of mice with different susceptibilities to DF (A/J, i.e. 'susceptible' and 129P3/J, i.e. 'resistant'). Weanling male and female susceptible and resistant mice fed a low-F diet were divided into 2 F-water treatment groups. They received water containing 0 (control) or 50 mg F/l for 6 weeks. Plasma and incisor enamel was analyzed for F content. For proteomic analysis, the enamel proteins extracted for each group were separated by 2-dimensional electrophoresis and subsequently characterized by liquid-chromatography electrospray-ionization quadrupole time-of-flight mass spectrometry. F data were analyzed by 2-way ANOVA and Bonferroni's test (p < 0.05). Resistant mice had significantly higher plasma and enamel F concentrations when compared with susceptible mice in the F-treated groups. The proteomic results for mice treated with 0 mg F/l revealed that during the secretory stage, resistant mice had a higher abundance of proteins than their susceptible counterparts, but this was reversed during the maturation stage. Treatment with F greatly increased the number of protein spots detected in both stages. Many proteins not previously described in enamel (e.g. type 1 collagen) as well as some uncharacterized proteins were identified. Our findings reveal new insights regarding amelogenesis and how genetic background and F affect this process.
在牙釉质形成过程中过量摄入氟（F）导致氟斑牙（DF）的机制仍未完全明确。近交系小鼠对DF的易感性存在差异，因此有助于研究影响DF严重程度的潜在分子事件。我们采用蛋白质组学方法，对两种对DF易感性不同的小鼠品系（A/J，即“易感”品系和129P3/J，即“抗性”品系）分泌期和成熟期牙釉质中的蛋白质表达变化进行表征和评估。将断奶的雌雄易感和抗性小鼠喂食低氟饮食，分为两个氟水处理组。它们接受含0（对照）或50 mg F/l的水，持续6周。分析血浆和切牙釉质中的氟含量。对于蛋白质组学分析，每组提取的牙釉质蛋白通过二维电泳分离，随后通过液相色谱电喷雾电离四极杆飞行时间质谱进行表征。氟数据通过双向方差分析和Bonferroni检验（p < 0.05）进行分析。在氟处理组中，抗性小鼠的血浆和牙釉质氟浓度显著高于易感小鼠。用0 mg F/l处理的小鼠的蛋白质组学结果显示，在分泌期，抗性小鼠的蛋白质丰度高于易感小鼠，但在成熟期则相反。氟处理大大增加了两个阶段检测到的蛋白质斑点数量。鉴定出许多以前未在牙釉质中描述的蛋白质（如I型胶原蛋白）以及一些未表征的蛋白质。我们的研究结果揭示了关于牙釉质形成以及遗传背景和氟如何影响这一过程的新见解。
