IGF-2和CDKN1C基因在单合子双胎选择性宫内生长受限胎盘中的表达

The expression of IGF-2 and CDKN1C in placenta of monozygotic twins with selective intrauterine growth restriction

目的探讨印迹基因IGF-2、CDKN1C在单绒毛膜双羊膜囊(MCDA)单合子双胎选择性宫内生长受限两胎胎盘中的表达,进而探讨IGF-2、CDKN1C基因与该疾病间的关系。方法收集20对MCDA双胎的临床资料及胎盘组织,其中双胎选择性宫内生长受限10例(sIUGR组),正常双胎10例作为对照组,用实时荧光定量PCR方法检测胎盘组织中的IGF-2、CDKN1C mRNA表达情况,且使用毛细血管电泳法对20对双胎行合子鉴定。结果经合子鉴定,20对双胎均为单合子双胎;sIUGR组的分娩孕周较对照组早(P<0.05);sIUGR组大胎的平均出生体重明显高于小胎(P<0.01),sIUGR组两胎之间的出生体重差显著大于对照组(P<0.01)。sIUGR组小胎胎盘中的IGF-2 mRNA表达水平低于大胎(P<0.05)。sIUGR组和对照组中大小胎胎盘中的CDKN1C基因mRNA表达均无明显差异(P>0.05)。结论择性宫内生长受限胎胎盘中IGF-2基因的表达降低,可能通过影响胎盘生长发育和降低胎盘营养转运功能干扰胎儿正常生长,导致其发生选择性宫内生长受限;CDKN1C基因与MCDA单合子双胎sIUGR的发病可能无相关性。

Objective To assess the imprinted gene IGF-2 and CDKN1C expression in placenta of monozygotic twins with selective intrauterine growth restriction（sIUGR）,and investigate the correlation between this disease and IGF-2 or CDKN1C.Methods Placental tissues and clinical data were collected from 20 pairs of monochorionic diamniotic twins,in which 10 cases of sIUGR as the study group,10 cases of normal twins as the control group.The zygotic characteristics were identified by STR assay.Real-time quantitative PCR method was used to measure the IGF-2 and CDKN1C mRNA expression in placental tissues.Results The 20 pairs of twins were all monozygotic twins.Significantly earlier delivery was observed in study group than that in control group（P〈0.05）.Significantly larger birth weight was revealed in large twins than that in small twins in the both groups,which was significantly more prominent in study group（P〈0.01）.In the group of sIUGR,significantly lower IGF-2 mRNA expression was observed in small twins than that in large twins（P〈0.05）.There was no significant difference in CDKN1C transcription level between the large and small twins in either study group or control group（P〈0.05）.Conclusion IGF-2 mRNA is down-regulated in the placenta of small twins in sIUGR,thus may interfere with normal fetal growth by affecting placental growth and reduced placental nutrient transport function,leading to the selective intrauterine growth restriction.There is no correlation between the CDKN1C gene and MCDA monozygotic twins with sIUGR.