Inhibin subunits mRNA expression level in human placenta from normal and Down's syndrome pregnancies.
In order to study the mechanisms leading to increased inhibin A and activin A in maternal serum with advancing gestation and increased inhibin A in Down's syndrome pregnancy, the mRNA expression level of inhibin and activin subunits was quantitatively studied in human placenta using Northern blot and semiquantitative RT-PCR analysis. The corresponding protein level was also determined by specific ELISAs for inhibin A, inhibin B, activin A and inhibin pro alphaC in placental extracts. Normal placenta (n=27) showed a slight significant increase in alpha and betaA subunit mRNA levels in term pregnancy, with no change of the corresponding protein level. Placenta from Down's syndrome pregnancies (n=6) did not differ from controls in either mRNA expression or corresponding protein levels. In conclusion, there is a dissociation between inhibin and activin subunit mRNA levels and the corresponding protein levels in maternal serum, and Down's syndrome inhibin A increase is not explained by mRNA expression upregulation. In an additional study, ovarian cortex tissue from term pregnancies (n=3) were examined. Only the alpha subunit mRNA was expressed, at a higher level than in the placenta, suggesting that ovary could be a source of inhibin pro alphaC during pregnancy.
Debiève
F
F
Department of Obstetrics and Gynecological Endocrinology, Faculty of Medicine, Université Catholique de Louvain, OBST 5330, Avenue Em. Mounier 53, B-1200 Brussels, Belgium. debieve@obst.ucl.ac.be
Pampfer
S
S
Thomas
K
K
D000328:Adult; D015152:Blotting, Northern; D004314:Down Syndrome / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005865:Gestational Age; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007265:Inhibins / Q000235:genetics* / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000737:chemistry; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014327:Trophoblasts / Q000378:metabolism*
D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D007265:Inhibins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases