性早熟女童雌激素受体基因多态性与环境内分泌干扰物效应关系的研究

Study on relationship between estrogen receptor gene polymorphism of precocious girls and environmental endocrine disruptors

目的研究性早熟女童雌激素受体α(estrogen receptorα,ERα)及雌激素受体β(estrogen receptorβ,ERβ)基因多态性与环境内分泌干扰物效应的关系,阐明机体对环境内分泌干扰物易感性差异的分子机制。方法收集2011年5月-2012年9月在江西省儿童医院内分泌专科门诊就诊的初诊性早熟女童123例,正常女童102例,运用高效液相色谱法测定患儿和正常女童血清四种[4-壬基酚(4-NP)、1,1-二氯-2,2-双对氯苯乙烯(P,P-DDE)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸-2-乙基乙酯(DEHP)]环境内分泌干扰物(EEDs)的含量,同时测定子宫、卵巢体积、骨密度及血清中雌二醇含量,将血清中四种EEDs的含量与靶器官的临床指标做相关分析;进一步用聚合酶链反应-限制性片段长度多态性(PCRRFLP)分析技术,对性早熟女童血清中分别能检出4-NP、DEHP、DBP和P,P'-DDE的患儿和正常对照分别不能检出以上4种内环境干扰物的女童ERα和ERβ基因多态性分析,观察它们之间的效应关系。结果正常儿童,38.4%血清中检测到P,P'-DDE,58%的血清中检测到4-NP,37%的血清中检测到DEHP,31%的血清中检测到DBP;性早熟患儿100%血清中均检测到P,P'-DDE,89.7%的血清中检测到4-NP,63.3%的血清中检测到DEHP,64.8%的血清中检测到DBP,且含量均高于正常儿童;性早熟女童血清中4-NP与子宫体积、卵巢容积、骨密度均呈正相关;P,P'-DDE与子宫体积也成正相关;ERα基因XbaⅠ基因型Xx以及ERβ基因RsaⅠ基因型RR在各组的危险度(OR)最高,Xx与xx相比较,分别对4-NP、DEHP、DBP和P,P'-DDE的易感性是2.52、7.01、6.21和2.63倍,RR与rr相比较,分别对4-NP、DEHP、DBP和P,P′-DDE的易感性是7.36、9.61、8.67和6.77倍。结论性早熟女童所受4-NP、DEHP、DBP和P,P'-DDE污染的程度比正常对照组女童严重,而且不同种类的EEDs对靶器官的致病作用不同;暴露于EEDs的儿童并非都发生性早熟的原因之一可能是由ERα和ERβ基因多态性引起,其中Xx和RR是EEDs的易感基因型。

Objective To study the relationship between estrogen receptor gene polymorphism of precocious girls and environmental endocrine disruptors,as well as,to clarify the molecular mechanisms of body＇s susceptibility to environmental endocrine disruptors differences. Methods The blood samples were collected from 123 cases of precocious girls and 102 cases of normal girls. The concentrations of 4-nonylphend （4-NP）,dibutyl phthalate （DBP）,DEHP and P,P-DDE in serum samples Were Measured by using high performance liquid chromatography（HPLC）,the volume of the uterus and ovary, the bone density, the content of estradiol（E2 ） were determined at the same time. The contents of 4-NP,DBP,DEHP and P, P- DDE in serum of precocious girls and the indices of the target organs were analyzed by using correlation. Further, estrogen receptor α （ERα） and estrogen receptor β （ERβ） gene polymorphisms were analyzed by using PCR-RFLP between the pre- cocious girls who can be detected 4-NP,DEHP,DBP and P,P＇-DDE in serum and normal controls who can not be detected the above four kinds of EEDs respectively and the effect relationship between them were observed. Results In normal control grodp,4-NP,DEHP,DBP and P,P-DDE,were detected in blood serum for 58% ,37% ,31% and 38.4% respective- ly,whereas,in precocious girls group, the four kinds of EEDs respectively were detected in blood serum for 89.7 %, 63.3 %, 64.8% and 100%. The levels of 4-NP,DEHP,DBP and P,P＇-DDE in serum in precocious girl group were notably increased than those in control group（P all〈0.01）. In precocious girls group, there was a positive correlations between the 4-NP in volume of uterus and the volume of ovary and the density of bone;P,P＇-DDE and volume of uterus also showed a the positive correlation. Compared girls with precocious puberty who can be detected 4-NP,DEHP, DBP and P, P＇-DDE in serum and nor- mal controls who can not be detected the above four kinds of EEDs respectively,there were significant differences in geno-type distribution for the Xba I and the Rsa I polymorphism. Compared Xx with wild-type xx, the susceptibility to 4-NP, DEHP,DBP and P,P-DDE was respectively 2.52,7.01,6.21 and 2.63 fold. Compared RR with wild-type rr,the susceptibil- ity to 4-NP,DEHP,DBP and P,P＇-DDE was respectively 7.36,9.61,8.67 and 6.77 fold. Conclusion Precocious girls are contaminated more severely than normal girls. Different kinds of EEDs might have different influencing extents to the target organs. Children exposed to EEDs haven＇t necessarily occurred precocious. One reason may be different genotypes expressed in different individuals. Xx and RR are susceptible genotypes to EEDs.