四氯二苯二噁英致胎鼠腭裂作用机制的初步探讨  

Mechanism of cleft palate in mice induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin

作　　者：蒲亚兰[1] 刘丽玲[1] 甘立强[1] 何晓梦[1] 傅跃先[1] 

机构地区：[1]重庆医科大学附属儿童医院烧伤整形外科,儿童发育疾病研究省部共建教育部重点实验室,儿科学重庆市重点实验室,重庆市（儿童发育重大疾病诊治与预防）国际科技合作基地,重庆400014

出　　处：《中华整形外科杂志》2011年第6期448-453,共6页Chinese Journal of Plastic Surgery

基　　金：重庆市自然科学基金重点项目（2009BA5085）

摘　　要：目的探讨四氯二苯二噁英（2，3，7，8-tetrachlorodibenzo-p-dioxin，TCDD）致胎鼠先天性腭裂的可能作用机制。方法12只C57BL／6J孕鼠于妊娠第10天随机分为实验组和对照组，每组6只，实验组以TCDD64μg／kg灌胃，对照组以等量玉米油灌胃，于妊娠第18．5天在解剖显微镜下观察胎鼠腭裂的发生率。另取18只C57BL／6J孕鼠，于妊娠第10天随机分为实验组和对照组，每组9只，处理方法同前，根据标本采集时间不同，每组又分为妊娠第13．5、14．5和15．5天3个亚组，每个亚组3只，分别于妊娠第13．5、14．5和15．5天剪取胎鼠腭突组织提取RNA和DNA，采用RT—PCR检测Smad2～4及Smad7mRNA的表达情况、甲基化特异性PCR（methylmion specific PCR，MSP）检测转化生长因子-β3（transforming growthfactor—β3，TGF—β3）基因启动子甲基化水平。两样本间均数比较采用t检验。结果TCDD成功诱导建立C57BL／6J胎鼠先天性腭裂模型，实验组腭裂发生率为100％，对照组无腭裂发生。在妊娠第13．5、14．5和15．5天，RT—PCR显示实验组Smad2mRNA的相对表达值分别为0．263±0．088、0．296±0．016和0．159±0．027，对照组为0．180±0．042、0．282±0．029和0．165±0．018，差异无统计学意义（t=-1．474、-0．762、0．321，P〉0．05）；实验组Smad3mRNA的相对表达值分别为0．453±0．153、0．551±0．160和0．328±0．049，对照组为0．375±0．126、0．510±0．145和0．259±0．035，差异无统计学意义（t=-0．678、-0．336、-2．005，P〉0．05）；实验组Smad4mRNA的相对表达值分别为0．675±0．174、0．577±0．070和0．396±0．066，对照组为0．557±0．138、0．587±0．080和0．441±0．054，差异无统计学意义（t=-0．926、0．161、0．927，P〉0．05）；实验组Smad7mRNA的相对表达值分别为0．283±0．050、0．320±0．068和0．169±0．045，对照组为0．207±0．043、0．288±0．051和0．15Objective To explm＇e the mechanism of cleft palate in mice induced by 2, 3, 7, 8- Tetrachlorodibenzo pdioxin （TCDD）. Methods On gestation day 10 （GD 10）, 12 pregnant mice were randmnly divided into two groups as the treated group and the eontrol group with 6 mice in each group. The mice in the treated group received intragastric administration with 64 p,g TCDD/kg, while the mice in the control group received equivalent corn oil. The embryos were examined under stereomicroscope to detect the incidence of cleft palate on GD 18.5. Another 18 pregnant mice were randomly divided into two groups （treated group and control group） on GD 10 with 9 pregnant mice in each group. Then each group was divided into 3 subgroups： GD 13.5, GD 14.5 and GD 15.5, with 3 pregnant mice in each subgroup. The palatal shelves were dissected from the embryos for RNA and DNA extraction on GD 13.5, GD 14, 5 and GD 15.5. At last the expression of Smad 24 and Smad 7 mRNA was investigated by RT-PCR, and the TGF-153 promoter methylamine levels were investigated by methylmion specific PCR （ MSP）. Results The cleft palate mice model was established successfully by exposing pregnant C57BL/6J mice to TCDD. Total frequency of clefts was 100% in TCDD group, and the frequency of clefts was 0 in the control group. The relative expression of Smad 2 mRNA was 0. 263 ± 0. 088, 0. 296± 0. 016 and 0. 159 ± 0. 027 in TCDD group, 0. 180 ±0. 042, 0. 282 ± 0. 029 and 0. 165 ± 0. 018 in control group. The relative expression of Smad 3 mRNA was 0. 453 ±0. 153, O. 551 ±0. 160 and 0. 328 ±0. 049 in TCDD group, 0. 375 ± 0. 126, 0. 510 ±0. 145 and 0. 259 ±0. 035 in control group. The relative expression of Smad 4 mRNA was 0. 675 ± 0. 174, 0. 577 ±0. 070 and 0. 396 ±0. 066 in TCDD group, 0. 557 ±0. 138, 0. 587 ±0. 080 and 0. 441 ± 0. 054 in control group. The relative expression of Smad 7 mRNA was 0. 283 ± 0. 050, 0. 320 ± 0. 068 and 0. 169 ±0.045 in TCDD group, 0.207 ±0.043, 0.288 ±0.051 and 0.155 ±0.040 in control group. Ther

关 键 词：腭裂 四氯二苯二噁英 转化生长因子-Β3 

分 类 号：R782.2[医药卫生—口腔医学]