Value of soluble fms-like tyrosine kinase-1/placental growth factor test in third trimester of pregnancy for predicting preeclampsia in asymptomatic women.

OBJECTIVES: To estimate the value of screening maternal serum soluble fms-like tyrosine kinase/placental growth factor (sFlt-1/PlGF) ratio in asymptomatic women during 3rd trimester to predict preeclampsia (PE) development. METHODS: The investigated group comprised of 178 pregnant women. During this gestation, 24 cases had developed PE and 12 isolated gestational hypertension (GH); whereas 142 remained normotensive. Blood samples were collected between 180 and 259 gestational days (g.d.) when the participants were asymptomatic. Serums were analyzed using the BRAHMS sFlt-1 Kryptor/BRAHMS PlGF plus Kryptor PE ratio test (Thermo Fisher Scientific, Henningdorf, Germany). High-risk pregnancies for the PE development were defined as sFlt-1/PlGF>38. RESULTS: The detection rate (DR) for manifestation of PE≤30 days after sampling was 83.3% and overall DR during pregnancy 58.3%. Ten of 15 women having false positive prediction of PE suffered from GH, preterm birth and/or delivery of a small-for-gestational-age-newborn. False positive rate was significantly higher at 239-253 g.d. compared to sampling at 210-224 g.d. and 225-238 g.d. (21.9% vs. 7.8% and 5.3%; p < 0.05). CONCLUSIONS: The sFlt-1/PlGF test during 180-259 g.d. detected approximately half of subsequent PE cases. An optimal time to use the test for screening purposes was estimated 225-238 g.d. (DR 66.7%). False positive test results were more common to cases with other adverse pregnancy outcomes and samples drawn at higher gestational age.

Extensive shift in placental transcriptome profile in preeclampsia and placental origin of adverse pregnancy outcomes.

One in five pregnant women suffer from gestational complications, prevalently driven by placental malfunction. Using RNASeq, we analyzed differential placental gene expression in cases of normal gestation, late-onset preeclampsia (LO-PE), gestational diabetes (GD) and pregnancies ending with the birth of small-for-gestational-age (SGA) or large-for-gestational-age (LGA) newborns (n = 8/group). In all groups, the highest expression was detected for small noncoding RNAs and genes specifically implicated in placental function and hormonal regulation. The transcriptome of LO-PE placentas was clearly distinct, showing statistically significant (after FDR) expressional disturbances for hundreds of genes. Taqman RT-qPCR validation of 45 genes in an extended sample (n = 24/group) provided concordant results. A limited number of transcription factors including LRF, SP1 and AP2 were identified as possible drivers of these changes. Notable differences were detected in differential expression signatures of LO-PE subtypes defined by the presence or absence of intrauterine growth restriction (IUGR). LO-PE with IUGR showed higher correlation with SGA and LO-PE without IUGR with LGA placentas. Whereas changes in placental transcriptome in SGA, LGA and GD cases were less prominent, the overall profiles of expressional disturbances overlapped among pregnancy complications providing support to shared placental responses. The dataset represent a rich catalogue for potential biomarkers and therapeutic targets.

Extensive load of somatic CNVs in the human placenta.

Placenta is a temporary, but indispensable organ in mammalian pregnancy. From its basic nature, it exhibits highly invasive tumour-like properties facilitating effective implantation through trophoblast cell proliferation and migration, and a critical role in pregnancy success. We hypothesized that similarly to cancer, somatic genomic rearrangements are promoted in the support of placental function. Here we present the first profiling of copy number variations (CNVs) in human placental genomes, showing an extensive load of somatic CNVs, especially duplications and suggesting that this phenomenon may be critical for normal gestation. Placental somatic CNVs were significantly enriched in genes involved in cell adhesion, immunity, embryonic development and cell cycle. Overrepresentation of imprinted genes in somatic duplications suggests that amplified gene copies may represent an alternative mechanism to support parent-of-origin specific gene expression. Placentas from pregnancy complications exhibited significantly altered CNV profile compared to normal gestations, indicative to the clinical implications of the study.

Mid-gestational gene expression profile in placenta and link to pregnancy complications.

Despite the importance of placenta in mediating rapid physiological changes in pregnancy, data on temporal dynamics of placental gene expression are limited. We completed the first transcriptome profiling of human placental gene expression dynamics (GeneChips, Affymetrix®; ~47,000 transcripts) from early to mid-gestation (n = 10; gestational weeks 5-18) and report 154 genes with significant transcriptional changes (ANOVA, FDR P<0.1). TaqMan RT-qPCR analysis (n = 43; gestational weeks 5-41) confirmed a significant (ANOVA and t-test, FDR P<0.05) mid-gestational peak of placental gene expression for BMP5, CCNG2, CDH11, FST, GATM, GPR183, ITGBL1, PLAGL1, SLC16A10 and STC1, followed by sharp decrease in mRNA levels at term (t-test, FDR P<0.05). We hypothesized that normal course of late pregnancy may be affected when genes characteristic to mid-gestation placenta remain highly expressed until term, and analyzed their expression in term placentas from normal and complicated pregnancies [preeclampsia (PE), n = 12; gestational diabetes mellitus (GDM), n = 12; small- and large-for-gestational-age newborns (SGA, LGA), n = 12+12]. STC1 (stanniocalcin 1) exhibited increased mRNA levels in all studied complications, with the most significant effect in PE- and SGA-groups (t-test, FDR P<0.05). In post-partum maternal plasma, the highest STC1 hormone levels (ELISA, n = 129) were found in women who had developed PE and delivered a SGA newborn (median 731 vs 418 pg/ml in controls; ANCOVA, P = 0.00048). Significantly higher expression (t-test, FDR P<0.05) of CCNG2 and LYPD6 accompanied with enhanced immunostaining of the protein was detected in placental sections of PE and GDM cases (n = 15). Our study demonstrates the importance of temporal dynamics of placental transcriptional regulation across three trimesters of gestation. Interestingly, many genes with high expression in mid-gestation placenta have also been implicated in adult complex disease, promoting the discussion on the role of placenta in developmental programming. The discovery of elevated maternal plasma STC1 in pregnancy complications warrants further investigations of its potential as a biomarker.

Differential placental expression profile of human Growth Hormone/Chorionic Somatomammotropin genes in pregnancies with pre-eclampsia and gestational diabetes mellitus.

The human GH/CSH cluster consisting of one pituitary-expressed (GH1) and four placenta-expressed loci has been implicated in maternal metabolic adaptation to pregnancy, regulation of intrauterine and postnatal growth. We investigated how the mRNA expression profile of placental GH2, CSH1 and CSH2 genes and their alternative transcripts correlates with maternal pre-eclampsia (PE) and/or gestational diabetes mellitus (GD). The expression of studied genes in PE placentas (n=17) compared to controls (n=17) exhibited a trend for reduced transcript levels. The alternative transcripts retaining intron 4, GH2-2 and CSH1-2 showed significantly reduced expression in PE cases without growth restriction (P=0.007, P=0.008, respectively). In maternal GD (n=23), a tendency of differential expression was detected only for the GH2 gene and in pregnancies with large-for-gestational-age newborns. Our results, together with those reported by others, are consistent with a pleiotropic effect of placental hGH/CSH genes at the maternal-fetal interface relating to the regulation of fetal growth and the risk of affected maternal metabolism.

Differential expression profile of growth hormone/chorionic somatomammotropin genes in placenta of small- and large-for-gestational-age newborns.

CONTEXT: The human growth hormone/chorionic somatomammotropin (hGH/CSH) locus at 17q22-24, consisting of one pituitary-expressed postnatal (GH1) and four placenta-expressed genes (GH2, CSH1, CSH2, and CSHL1), is implicated in regulation of postnatal and intrauterine growth. A positive correlation has been reported between the offspring's birth weight and serum placental GH (coded by GH2) and placental lactogen (coded by CSH1, CSH2) levels in pregnant women. OBJECTIVE: The objective of the study was the investigation of the hypothesis that the mRNA expression profile of placental hGH/CSH genes contributes to the determination of birth weight. DESIGN AND SUBJECTS: We developed a sensitive, fluorescent-labeled semiquantitative RT-PCR assay coupled with gene-specific restriction analysis, capable of distinguishing alternative splice-products of individual placental hGH/CSH genes and quantification of their relative expression levels. The detailed profile of alternative transcripts of GH2, CSH1, CSH2, and CSHL1 genes in placenta from uncomplicated term pregnancies of the REPROMETA sample collection was addressed in association with the birth weight of newborns, grouped as appropriate for gestational age (AGA; n = 23), small for gestational age (SGA; n = 15), and large for gestational age (LGA; n = 34). RESULTS: The majority of pregnancies with SGA newborn showed down-regulation of the entire hGH/CSH cluster in placenta, whereas in the case of LGA, the expression of CSH1-1, CSH2-1, and CSHL1-4 mRNA transcripts in placenta was significantly increased compared with AGA newborns (P < 0.0001, P = 0.009, P = 0.002, respectively). CONCLUSION: The expression profile of placental hGH/CSH genes in placenta is altered in pregnancies accompanied by SGA and LGA compared with AGA newborns, and thus, it may directly affect the circulating fetal and maternal placental GH and placental lactogen levels.