C-Reactive Protein Production in Term Human Placental Tissue

• Published in: Placenta (Eastbourne) Vol. 27; no. 6; pp. 619 - 625
• Main Authors: Malek, A., Bersinger, N.A., Di Santo, S., Mueller, M.D., Sager, R., Schneider, H., Ghezzi, F., Karousou, E., Passi, A., De Luca, G., Raio, L.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-06-2006; Elsevier
• Subjects: Adult; Biological and medical sciences; Biomarkers - metabolism; C-Reactive Protein - genetics; C-Reactive Protein - metabolism; Chorionic Gonadotropin - metabolism; CRP levels; Embryology: invertebrates and vertebrates. Teratology; Female; Fetal Blood - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression; Human placenta; Humans; In vitro perfusion; In Vitro Techniques; Leptin - metabolism; Maternal blood; Placenta - blood supply; Placenta - cytology; Placenta - metabolism; Placental Lactogen - metabolism; Pregnancy - blood; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Term Birth - metabolism; Umbilical Arteries; Umbilical artery blood; Umbilical vein blood; Umbilical Veins; Maternal blood; Umbilical vein blood; Human placenta; CRP levels; Umbilical artery blood; In vitro perfusion; Human; Tissue; Vertebrata; Mammalia; Placenta; Fetal membrane; C reactive protein
• ISSN: 0143-4004; 1532-3102
• DOI: 10.1016/j.placenta.2005.05.009

C-reactive protein (CRP) is a marker of systemic inflammation. Recently, it has been shown that CRP is present in amniotic fluid and fetal urine, and that elevated levels are associated with adverse pregnancy outcome. However, the precise source of amniotic fluid CRP, its regulation, and function during pregnancy is still a matter of debate. The present in vivo and in vitro studies were designed to investigate the production of CRP in human placental tissues.
Ten paired blood samples from peripheral maternal vein (MV), umbilical cord artery (UA) and umbilical vein (UV) were collected from women with elective caesarean sections at term. The placental protein accumulation capacity of hCG, hPL, leptin and CRP was compared with the dual in vitro perfusion method of an isolated cotyledon of human term placentae and quantified by ELISA. Values for accumulation (release) were calculated as total accumulation of maternal and fetal circuits normalized for tissue weight and duration of perfusion. For gene expression, RNA was extracted from placental tissue and reverse transcribed. RT-PCR and real-time PCR were performed using specific primers.
The median (range) CRP level was significantly different between UA and UV [50.1
ng/ml (12.1–684.6) vs. 61
ng/ml (16.9–708.1)]. The median (range) difference between UV and UA was 9.3
ng/ml (2.2–31.6). A significant correlation was found between MV CRP and both UA and UV CRP levels. Median (range) MV CRP levels [2649
ng/ml (260.1–8299)] were 61.2 (6.5–96.8) fold higher than in the fetus. In vitro, the total accumulation rates (mean
±
SD) were 31
±
13 (mU/g/min, hCG), 1.16
±
0.19 (μg/g/min, hPL), 4.71
±
1.91 (ng/g/min, CRP), and 259
±
118 (pg/g/min, leptin). mRNA for hCG, hPL and leptin was detectable using conventional RT-PCR, while CRP mRNA could only be demonstrated by applying real-time RT-PCR. In the perfused tissue the transcript levels for the four proteins were comparable to those detected in the native control tissue.
Our results demonstrate that the human placenta produces and releases CRP mainly into the maternal circulation similarly to other analyzed placental proteins under in vitro conditions. Further studies are needed to explore the exact role of placental CRP during pregnancy.