Expression of insulin-like growth factor-II and insulin-like growth factor binding protein-1 in the placental basal plate from pre-eclamptic pregnancies.
OBJECTIVE
To determine whether expressions of insulin-like growth factor-II (IGF-II) and insulin-like growth factor binding protein-1 (IGFBP-1) are altered in pre-eclamptic placenta and to elucidate the possible relationship between their expressions and a mechanism for inadequate trophoblast invasion in pre-eclampsia.


METHODS
Placental tissues were obtained at cesarean delivery from five normotensive, nine mild pre-eclamptic and five severe pre-eclamptic women at 33-39 completed weeks of gestation. After total ribonucleic acid was extracted, reverse transcriptase-polymerase chain reaction was performed to determine IGF-II and IGFBP-1 mRNA expression. Product bands were quantitated by scanning densitometry and results were expressed as ratio of cytokines/beta-actin. Western blot analysis was also done to determine IGF-II and IGFBP-1 protein expression. Statistical analysis was determined by Kruskal-Wallis analysis of variance with the Scheffe multiple post-hoc test.


RESULTS
The IGF-II mRNA levels of mild and severe pre-eclamptic placenta were significantly lower than that of uncomplicated placenta (P<0.005, P<0.001, respectively), with the level of severe pre-eclamptic placenta being significantly lower than that of mild pre-eclamptic placenta (P<0.05). As for the IGF-II protein expression, a significant decrease was found among the three groups (P<0.001), correlating with the IGF-II mRNA results. However, the mean IGFBP-1 mRNA levels of mild and severe pre-eclamptic placenta were significantly higher than that of uncomplicated placenta (P<0.05, P<0.005, respectively), with the level of severe pre-eclamptic placenta being significantly raised compared with that of mild pre-eclamptic placenta (P<0.05). Finally, a significant increase of IGFBP-1 protein expression was noted among the three groups (P<0.001), correlating with the IGFBP-1 mRNA results.


CONCLUSIONS
This study suggests that IGF-II and IGFBP-1 might be associated with the impaired trophoblastic invasion that may lead to pathogenesis of pre-eclampsia.
Shin
J C
JC
Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Medical College, Catholic University of Korea, Seoul, South Korea. jcshin@catholic.ac.kr
Lee
J H
JH
Yang
D E
DE
Moon
H B
HB
Rha
J G
JG
Kim
S P
SP
D000199:Actins / Q000032:analysis / Q000235:genetics; D000328:Adult; D005260:Female; D015870:Gene Expression / Q000235:genetics*; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000032:analysis* / Q000235:genetics*; D007335:Insulin-Like Growth Factor II / Q000032:analysis* / Q000235:genetics*; D010920:Placenta / Q000737:chemistry* / Q000503:physiopathology; D011225:Pre-Eclampsia / Q000235:genetics* / Q000503:physiopathology; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012720:Severity of Illness Index; D014327:Trophoblasts / Q000502:physiology
D000199:Actins; D018970:Insulin-Like Growth Factor Binding Protein 1; D012333:RNA, Messenger; D007335:Insulin-Like Growth Factor II