氟化钠染毒致大鼠骨组织形态计量学及微小RNA-23a表达的变化  

Changes in bone histomorphometry and microRNA-23a expression in rats exposed to sodium fluoride

作　　者：代佑罡 韦艳 陈宣好 祁忠达 张华 DAI You-gang;WEI Yan;CHEN Xuan-hao;QI Zhong-da;ZHANG Hua(Department of Occupational Health and Environmental Hygiene, School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou 550004, China)

机构地区：[1]贵州医科大学公共卫生学院职业卫生与环境卫生学系环境污染与疾病监控教育部重点实验室,贵州贵阳550004

出　　处：《环境与职业医学》2019年第3期254-260,共7页Journal of Environmental and Occupational Medicine

基　　金：国家自然科学基金(81560515);科技部国家科技支撑计划课题(2013BAI05B03)

摘　　要：[目的]探讨氟化钠染毒致大鼠骨组织形态计量学变化及对微小RNA(miR NA)-23a表达的影响。[方法 ]将96只SD大鼠按体重随机分为对照组(0 mg/L)、低氟组(50 mg/L)、中氟组(150 mg/L)、高氟组(250 mg/L)。采取饮水染毒方式,染氟至2、4、6个月时分别处死每组8只SD大鼠,收集大鼠左下肢及牙齿,采用灰化-氟离子电极法测定大鼠骨氟、牙氟含量;取大鼠股骨干骺端固定后脱钙,进行苏木精-伊红染色,光镜观察骨组织骨小梁、骺板、成骨细胞的形态学改变;取左前肢,剔除多余结缔组织,用液氮反复研磨成骨粉,使用RNAiso Plus提取骨粉总RNA,采用实时荧光定量PCR法测定miRNA-23a基因表达水平。[结果 ]除2个月时的低氟组外,不同时间各染毒组大鼠氟斑牙检出率均高于对照组(P <0.05)。随染毒时间的延长,各染氟组大鼠骨氟、牙氟含量呈上升的趋势。不同时期中氟组、高氟组大鼠骨小梁和各剂量组骺板面积均大于对照组(P <0.05),低氟组骨小梁面积均低于对照组(P <0.05)。随着染氟剂量的增加,骨小梁和骺板面积呈上升趋势;在2、4、6个月时各剂量组间差异有统计学意义(P <0.01)。各时期染氟大鼠成骨细胞数量均低于对照组(P <0.05),且随着剂量升高呈下降趋势。随着染毒时间的延长,各染氟组骨小梁、骺板面积以及成骨细胞数量均呈下降趋势。染氟2、4、6个月时,各染氟组大鼠miRNA-23a表达量均高于对照组(P <0.05);染氟6个月时,各染氟组大鼠miRNA-23a表达量均较2个月和4个月时升高,呈上升趋势。[结论 ]过量、长期的氟摄入会影响骨的形成和发育,推测miRNA-23a参与了氟中毒致大鼠体内骨转换异常的过程,提示miRNA-23a与氟致全身性危害具有潜在的关联性,但其参与机制尚未明确,有待进一步研究。[Objective] To investigate the effects of different doses of sodium fluoride exposure on histomorphometric change of bone and miRNA-23 a expression in rats at different developmental stages.[Methods] Ninety-six SD rats were randomly divided into control(0 mg/L) and low(50 mg/L),moderate(150 mg/L), and high(250 mg/L) fluoride treated groups. The animals were executed after 2, 4, and 6 months of the treatment via drinking water to determine bone and dental fluoride levels in left lower limb and teeth by ashing-fluoride ion selective eletrode method. The rat femoral metaphysis samples were stained with hematoxylin-eosin(HE) after decalcification,and observed under optical microscope for evaluating morphological changes in trabeculae,epiphyseal plate, and osteoblasts. The expression levels of miRNA-23 a in total RNA extracted by RNAiso Plus from bone meal of left rat forelimb were detected by real-time fluorescence quantitative PCR.[Results] Except the low NaF group at 2 months, the dental fluorosis incidence rates of each NAF group at different time points were statistically higher than those of the control group(P <0.05). The bone and dental fluoride concentrations of each NaF group were increased over exposure time. At different time points, the trabecular area and epiphyseal area of both moderate and high NaF groups were statistically higher than those of the control group(P < 0.05), while the trabecular area of the low NaF group was statistically lower(P < 0.05). Both trabecular area and epiphyseal area showed rising trends with the increase of NaF dose, with statistical differences among the groups after 2, 4, and 6 months of treatment(P < 0.01). After the treatment for different time, the numbers of osteoblasts of each NaF group were statistically lower than that of the control group(P < 0.05), and showed a decreasing trend with the increase of NaF dose. The trabecular area, epiphyseal area, and number of osteoblasts all showed downward trends with prolonged time of the NaF treatment(P < 0.05). After the treat

关 键 词：氟化钠 氟中毒 骨形态计量学 miRNA-23a 

分 类 号：R114[医药卫生—卫生毒理学]