Translational Analysis of Mouse and Human Placental Protein and mRNA Reveals Distinct Molecular Pathologies in Human Preeclampsia

Abstract

Preeclampsia (PE) adversely impacts ϳ5% of pregnancies. Despite extensive research, no consistent biomarkers or cures have emerged, suggesting that different molecular mechanisms may cause clinically similar disease. To address this, we undertook a proteomics study with three main goals: (1) to identify a panel of cell surface markers that distinguish the trophoblast and endothelial cells of the placenta in the mouse; (2) to translate this marker set to human via the Human Protein Atlas database; and (3) to utilize the validated human trophoblast markers to identify subgroups of human preeclampsia. To achieve these goals, plasma membrane proteins at the blood tissue interfaces were extracted from placentas using intravascular silica-bead perfusion, and then identified using shotgun proteomics. We identified 1181 plasma membrane proteins, of which 171 were enriched at the maternal blood-trophoblast interface and 192 at the fetal endothelial interface with a 70% conservation of expression in humans. Three distinct molecular subgroups of human preeclampsia were identified in existing human microarray data by using expression patterns of trophoblast-enriched proteins. Analysis of all misexpressed genes revealed divergent dysfunctions including angiogenesis (subgroup 1), MAPK signaling (subgroup 2), and hormone biosynthesis and metabolism (subgroup 3). Subgroup 2 lacked expected changes in known preeclampsia markers (sFLT1, sENG) and uniquely overexpressed GNA12. In an independent set of 40 banked placental specimens, GNA12 was overexpressed during preeclampsia when co-incident with chronic hypertension. In the current study we used a novel translational analysis to integrate mouse and human trophoblast protein expression with human microarray data. This strategy identified distinct molecular pathologies in human preeclampsia. We conclude that clinically similar

Evolutionarily conserved intercalated disc protein Tmem65 regulates cardiac conduction and connexin 43 function

“…In-depth studies of membrane proteins have proven to be difficult because of their low abundance and hydrophobicity 1,4 . However, recent advances in proteomic technologies make it possible to investigate proteins in this cell compartment, including previously unannotated membrane proteins, to an impressive depth [4][5][6][7][8][9] . In this study, we applied colloidal silica-bead coating 10 to enrich for conserved cell-surface-associated proteins in mouse neonatal and human fetal ventricular cardiomyocytes.…”

“…Plasma membrane fractions from primary neonatal cardiomyocytes were isolated using a modified cationic silica-bead plasma membrane isolation procedure 8,59 . Plated cardiomyocytes were first washed three times with MES-buffered saline (MBS; 25 mM 2-(N-morpholino)ethanesulfonic acid (MES), pH 6.5 and 150 mM NaCl) and then coated with 1% ice-cold silica beads for 10 min, washed three times in MBS and then incubated in 0.1% polyacrylic acid to block the free cationic groups on the silica beads.…”

Genetic recapitulation of human pre-eclampsia risk during convergent evolution of reduced placental invasiveness in eutherian mammals

“…R. Soc. B 370: 20140069 the overlap between the set of genes targeted by natural selection and genes involved in multiple placental pathologies supports the view that placental disorders are highly multifactorial and that there may exist different genetic routes to common symptomatic states [63]. Controversy has also been raised over the relative contribution to pre-eclampsia of the maternal and fetal components of the placenta, especially the role of the maternal immune system in the disease [64].…”

Placental transcriptome in development and pathology: expression, function, and methods of analysis

“…8,104,105 Factors that originate and influence the progression of these pathologies can be environmental, genetic (mother, fetus, father, or even all 3), or due to an interaction between the mother and the placenta. Furthermore, PE demonstrates a wide range of patient symptoms, placental histopathology, 8,9,[106][107][108] and molecular heterogeneity. 9,82,108 As such, a significant criticism of the majority of published microarray studies is the treatment of PE as a single pathology, which is counter to this assessment of multifactorial disease.…”