摘要
目的探究饮水型氟中毒大鼠的骨组织miR-23a表达改变对其氟斑牙、尿氟、牙氟和骨氟含量的影响。方法将48只2周龄清洁级SD雄性大鼠按体重随机分为6组,分别为对照组、NaF染毒组、mi R-23a激动剂组、NaF染毒+miR-23a激动剂组、miR-23a抑制剂组、NaF染毒+miR-23a抑制剂组,每组8只。动物每天连续自由饮用250 mg/L氟化钠溶液;每周尾静脉注射miR-23a的激动剂与抑制剂(150μl/只)1次,以分别模拟miR-23a的过表达和缺失,连续染毒6个月。动态观察染氟期间大鼠氟斑牙情况,测定大鼠尿氟、牙氟和骨氟含量。结果对照组、mi R-23a激动剂组、miR-23a抑制剂组均未检出氟斑牙;而不同时间NaF染毒组、NaF染毒+miR-23a激动剂组和NaF染毒+miR-23a抑制剂组大鼠氟斑牙检出率均为100%。染氟约36天时,NaF染毒组大鼠开始出现氟斑牙,随着染氟时间的延长,氟斑牙症状加重,牙齿出现不规则棕、白色相间横纹。干预组大鼠约从28天开始出现氟斑牙症状,比染氟组早约1周。随着干预时间的延长,NaF染毒+mi R-23a激动剂组与NaF染毒+miR-23a抑制剂组大鼠氟斑牙程度以中、重度氟斑牙为主,两个干预组氟斑牙情况无明显差异。各染氟组大鼠的尿氟浓度均高于同一时间点(第2、4、6个月)的对照组、miR-23a激动剂组和miR-23a抑制剂组,差异均有统计学意义(P<0.05);而同一时间点,NaF染毒组、NaF染毒+miR-23a激动剂组和NaF染毒+miR-23a抑制剂组大鼠的尿氟浓度间比较,差异无统计学意义(P>0.05);随着染氟时间的延长,各组大鼠的尿氟浓度均呈上升的趋势。各染氟组大鼠的骨氟、牙氟含量均高于对照组、miR-23a激动剂组和miR-23a抑制剂组,差异均有统计学意义(P<0.05)。对照组、miR-23a激动剂组和miR-23a抑制剂组大鼠的骨氟、牙氟含量间比较,差异无统计学意义(P>0.05)。大鼠的骨氟、牙氟含量依次为NaF染毒+miR-23a抑制剂组<NaF染毒组<NaF染毒+miR-23a激动剂组,差异均有统计学意义(P<0.05)。结论氟中毒大鼠骨组织miR-23a的表达上调和下调均可加重大鼠氟斑牙症状,且miR-23a的表达下调可以降低氟中毒大鼠骨氟和牙氟的含量。
Objective To understand the effects of miR-23 a expression in bone tissue of rats with drinking water fluorosis on dental fluorosis,urine fluoride,dental fluoride and bone fluoride.Methods A total of 48 male SD rats were randomly divided into the control group,NaF group,miR-23 a agonist group,NaF+miR-23 a agonist group,miR-23 a inhibitor group and NaF+mi R-23 a inhibitor group,eight rats in each group.The rats were exposed to fluoride through drinking water containing 250 mg/L sodium fluoride(NaF)to establish the rats model of drinking water fluorosis.Meanwhile,in order to simulate the over expression and knockout of miR-23 a in fluorosis rats,the rats were injected with miR-23 a agonist and inhibitor(150μl per animal)via tail vein once a week,for consecutive six months.Dynamic observation of dental fluorosis was performed in rats exposed to fluoride,at the end of exposure,the contents of urinary fluoride,dental fluoride and bone fluoride in rats were measured.Results Dental fluorosis was not detected in the control group,miR-23 a agonist group,and miR-23 a inhibitor group,however,the detection rates of dental fluorosis in NaF group,NaF+miR-23 a agonist group and NaF+miR-23 a inhibitor group were 100%at different times.After about 36 days of fluoride exposure,the rats in NaF-exposed groups began to develop dental fluorosis;With the prolonged exposure to fluoride,the symptoms of dental fluorosis were aggravated in rats,and irregular brown and white stripes appeared on the teeth.The rats in the intervention groups started to develop dental fluorosis symptoms after about28 days of fluoride exposure,about one week earlier than the NaF-exposed groups.With the extension of the intervention time,the degree of dental fluorosis of NaF+miR-23 a agonist group and NaF+miR-23 a inhibitor group were mainly moderate and severe dental fluorosis,and there was no significant difference between these two groups.The fluoride content in urine showed significantly higher levels in each fluoride-exposed group compared with the control group,miR-23 a agonist group and miR-23 a inhibitor group at the same time point(the 2 th,4 th,and 6 th month),the differences were statistically significant(P<0.05).Meanwhile,there were no statistical differences in the urinary fluoride content of rats at the same time point in the NaF group,NaF+miR-23 a agonist group and NaF+miR-23 a inhibitor group(P>0.05);The level of urinary fluoride increased with the prolongation of fluoride exposure time.The content of bone fluoride and dental fluoride in each fluoride-exposed group showed significantly higher level compared with the control group,miR-23 a agonist group and miR-23 a inhibitor group,the differences were statistically significant(P<0.05);There were no significant difference in the bone fluoride and dental fluoride level of rats in the control group,miR-23 a agonist group and miR-23 a inhibitor group(P>0.05).The levels of bone fluoride and dental fluoride in rats ranked as NaF+miR-23 a inhibitor group<NaF group<NaF+miR-23 a agonist group,with significant differences(P<0.05).Conclusion The up-regulation and down-regulation of miR-23 a in the bone tissue of rats with fluorosis can aggravate the symptoms of dental fluorosis,and down-regulation of miR-23 a can reduce the content of bone fluoride and dental fluoride in the rats with fluorosis.
作者
卢明丽
杨璐珲
代佑罡
王楠兰
张华
韦艳
LU Ming-li;YANG Lu-hui;DAI You-gang;WANG Nan-lan;ZHANG Hua;WEI Yan(School of Public Health,the Key Laboratory of Environmental Pollution Monitoring and Disease Control,Ministry of Education,Guizhou Medical University,Guiyang,Guizhou 550025,China;不详)
出处
《环境与健康杂志》
CAS
北大核心
2020年第7期590-594,共5页
Journal of Environment and Health
基金
国家自然科学基金(81560515)
关键词
饮水型氟中毒大鼠
miR-23a
氟斑牙
尿氟
牙氟
骨氟
Rats with drinking water fluorosis
miR-23a
Dental fluorosis
Urine fluoride
Dental fluoride
Bone fluoride
