Abstract

Recent publications have demonstrated the possibility of trophoblastic cells retrieval from cervical brushing of pregnancy patients since the fifth week. This strategy has the potential of early non-invasive study of placental dysfunction markers. At the present, research efforts to obtain trophoblast cells have focused on a genomic/ transcriptomics approach. We explore the possibility of identifying placental proteins in cervico-vaginal brushing during the first trimester of pregnancy. A sample of one voluntary pregnant women (9 gestational weeks) and nonpregnant control participated in this study. Cervico-vaginal brushings were collected using Rovers Cervex-Brush (DB) and transported in RPMI culture medium. Samples were centrifuged and cells lysed under standard procedures. After digestion with trypsin, peptides were quantified by IR and processed triplicated in a nanoHPLC (nanoElute) Mass Spectrometry using our TimsTOFpro instrument (Bruker). Protein identification was performed by Swissprot/Uniprot database (560,292 entries) for human taxonomy using the PEAKS studio X bioinformatic platform. We obtained 86,346 identified spectra and 11,055 peptides with a total of 1,206 proteins. After filtering by constitutive proteins from the cervico-vaginal tract and comparing with a reference proteome for placenta (ProteinAtlas). 15 placentary protein were identified. Of note, different isoforms of choriogonadotropin subunit beta were identified by mass spectrometry, indicating the suitability of this proteomics approach to find specific biomarkers of placenta. This proof of concept underlines the potential of using cervico-vaginal brushing to identify placental biomarkers by bottom up mass spectrometry. The technique is safe and minimally invasive. Further studies in different clinical conditions are warranted