Messenger ribonucleic acid levels of pregnancy-associated plasma protein-A and the proform of eosinophil major basic protein: expression in human reproductive and nonreproductive tissues.
PAPP-A/proMBP, the complex of pregnancy-associated plasma protein-A (PAPP-A) and the proform of eosinophil major basic protein (proMBP), circulates at increasing levels during pregnancy. The major site of synthesis is the placenta, in which PAPP-A mRNA has been localized to the syncytiotrophoblast and the placental X cells, whereas proMBP mRNA has been localized to the placental X cells only. The function of PAPP-A/proMBP and its components has remained speculative for years. Recently, however, it has been shown that PAPP-A specifically cleaves insulin-like growth factor (IGF) binding protein-4 in an IGF-dependent manner. Female reproductive and nonreproductive tissues have previously been reported to contain PAPP-A immunoreactivity, based on studies using preparations of anti(PAPP-A/proMBP), now known to recognize both PAPP-A and proMBP, and other irrelevant antigens. To analyze for the presence of PAPP-A and proMBP mRNA, a sensitive semiquantitative reverse transcription (RT) polymerase chain reaction (PCR) method was developed. Reverse-transcribed poly(A)(+) RNA was used as a template in a competitive PCR. PAPP-A and proMBP mRNA levels were normalized against the level of beta-actin mRNA. Both mRNA species were significantly more abundant in term placenta than in other tissues analyzed. All analyzed tissues, including endometrium, myometrium, colon, and kidney, contained both PAPP-A and proMBP mRNA.
Overgaard
M T
MT
Department of Molecular and Structural Biology, University of Aarhus, 8000 Aarhus C, Denmark.
Oxvig
C
C
Christiansen
M
M
Lawrence
J B
JB
Conover
C A
CA
Gleich
G J
GJ
Sottrup-Jensen
L
L
Haaning
J
J
D000199:Actins / Q000096:biosynthesis / Q000235:genetics; D001798:Blood Proteins / Q000096:biosynthesis*; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000378:metabolism; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011266:Pregnancy-Associated Plasma Protein-A / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000378:metabolism*; D012260:Ribonucleases / Q000378:metabolism
D000199:Actins; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D018836:Inflammation Mediators; D012333:RNA, Messenger; D012260:Ribonucleases; D011266:Pregnancy-Associated Plasma Protein-A