Klotho基因在高浓度Mg^(2+)致骨密度降低大鼠中的表达  

Study on Klotho gene expression in kidney of Mg-over supplement rat

作　　者：竺淑佳[1] 顾怡然[1] 李世佳[1] 章蓉[1] 徐敏华[1] 梅兵[1] 

机构地区：[1]华东师范大学脑功能基因组学研究所,上海200062

出　　处：《中国现代医学杂志》2009年第16期2401-2404,2408,共5页China Journal of Modern Medicine

基　　金：科技部"973计划"项目子课题资助项目(No:2003CB716602)

摘　　要：目的研究高镁食物对雌性大鼠骨密度的影响,并通过比较卵巢摘除大鼠与高镁喂食大鼠体重、钙磷等矿物质含量以及Klotho基因表达情况,探讨镁过量引起骨密度变化可能的分子机制。方法实验大鼠分为4组,A、B组为假手术组,C、D组为卵巢摘除组;A、C组喂食基础饲料,B、D组喂食添加碳酸镁(180mg/kg体重)的基础饲料。3个月后分别测定各组大鼠血清中的钙磷浓度与ALP活性,X射线法检测两组大鼠股骨密度,实时荧光定量PCR法评估两组大鼠肾脏组织中Klotho基因的表达量。结果与喂食基础饲料的假手术组相比,其他3组大鼠的骨密度显著降低,血钙浓度明显升高;高镁食物导致大鼠肾脏组织中Klotho基因表达下调。结论高镁食物导致大鼠股骨密度下降,且Klotho基因的下调及其对相关信号通路的影响可能是其分子机制之一。[ Objectives] To study the effect on bone mineral density （BMD） in female rat induced by Mg-over supplement, and to discuss the possible mechanism of osteoporosis. [Methods] We divided female rats into 4 groups, group C and D were operated on the ovariectomized surgery, while group A and B were operated on the fake surgery. Group B and D were fed high dosage of MgCO3, while A and C were fed control food. After three months, we measured the level of serum Calcium, phosphorus, alkaline phosphatase （ALP） and BMD of aU 4 groups mice, re- spectively, as well evaluated their Klotho gene expression profile of kidney by real time quantitative PCR. [Results] The data showed that estrogen-deficiency and Mg-over supplement significantly decreased BMD, increased Calcium concentration in serum. Mg-over supplement reduced phosphorus concentration （group B, D）, while estrogen-defi- ciency did not （group C）. In addition, estrogen-deficiency and/or Mg-over supplement dramatically down-regulated the expression level of Klotho gene （group B, C, D）. [ Conclusion] This study suggests that Mg-over supplement could result in BMD decreasing and down-regulation of Klotho expression, which could be one of the molecular mechanisms underlying osteoporosis induced by high dosage of Mg-supplement.

关 键 词：镁 骨密度 KLOTHO基因 去势大鼠 实时荧光定量PCR 

分 类 号：R-332[医药卫生] Q786[生物学—分子生物学]