Calcium and Phosphorus Levels in Saliva are Influenced by Genetic Polymorphisms in Estrogen Receptor Alpha and Microrna17

Abstract Homeostasis between salivary calcium and phosphorus is important for maintaining oral health. The aim of this study was to evaluate if polymorphisms in ESR1 (Estrogen Receptor Alpha), ESR2 (Estrogen Receptor Beta) and miRNA17 (microRNA17) are associated with calcium and phosphorus levels in saliva. Saliva from 276 12-year-old children were collected by masticatory stimulation and calcium and phosphorus levels were determined by Mass Spectrometry. Genomic DNA was extracted from remaining saliva and genetic polymorphisms in ESR1 (rs12154178, rs1884051, rs9340799 and rs2234693), in ESR2 (rs4986938 and rs1256049) and in miRNA17 (rs4284505) were genotyped using TaqMan chemistry and a real-time PCR equipment. Statistical differences in genotype and allele distributions between ‘low’ and ‘high’ calcium and phosphorus levels were determined using chi-square or Fisher´s exact tests. The analysis was also adjusted by sex (alpha of 5%). ESR1 rs9340799 had the less common genotype associated with higher calcium levels (p=0.03). The less common allele of ESR1 rs1884051 was associated with lower phosphorus levels (p=0.005) and there was an excess of heterozygotes for miRNA17 rs4284505 among individuals with lower calcium levels (p=0.002), both adjusted by sex. This study provides evidence that genetic polymorphisms in ESR1 and miRNA17 are involved in determining salivary calcium and phosphorus levels.

摘要 唾液钙磷稳态对于维持口腔健康具有重要意义。本研究旨在评估雌激素受体α（Estrogen Receptor Alpha，ESR1）、雌激素受体β（Estrogen Receptor Beta，ESR2）及微小RNA17（microRNA17，miRNA17）的基因多态性是否与唾液钙、磷水平相关。本研究通过咀嚼刺激法采集了276名12岁儿童的唾液样本，采用质谱法（Mass Spectrometry）检测其中钙与磷的含量。从剩余唾液样本中提取基因组DNA，使用TaqMan化学试剂（TaqMan chemistry）与实时荧光定量PCR（real-time PCR）设备，对ESR1的rs12154178、rs1884051、rs9340799及rs2234693，ESR2的rs4986938、rs1256049，以及miRNA17的rs4284505进行基因分型。采用卡方检验或Fisher确切概率法分析钙、磷水平“低组”与“高组”间的基因型及等位基因分布差异，并以性别作为协变量进行校正（检验水准α=5%）。分析结果显示：ESR1 rs9340799的稀有基因型与较高的唾液钙水平相关（p=0.03）；ESR1 rs1884051的稀有等位基因与较低的唾液磷水平相关（p=0.005）；经性别校正后，唾液钙水平较低的个体中，miRNA17 rs4284505的杂合子比例显著偏高（p=0.002）。本研究证实，ESR1及miRNA17的基因多态性与唾液钙、磷水平的调控存在关联。