Proteomics Analysis of Human Chorionic Villi Reveals Dysregulated Pathways That Contribute to Recurrent Pregnancy Loss

Purpose: Recurrent pregnancy loss (RPL) represents a common disorder with consequences on family and society. As more than half of the RPL cases do not have a clearly identified cause, uncovering the mechanisms behind the idiopathic RPL is urgently needed.

Experimental design: Using label-free data-independent LC-MS/MS acquisition coupled with ion mobility, we compared the proteome of chorionic villi from 13 RPL cases with 10 age and gestational week-matched elective pregnancies. Transcriptional levels of selected candidate biomarkers were determined in chorionic villi of 35 RPL cases and 25 controls using quantitative polymerase chain reaction (qPCR).

Results: Statistically significant difference in abundance (Benjamini-Hochberg [B-H] p ≤ 0.05) and fold change ≥1.5 showed 128 proteins. Bioinformatics analysis identified complement and coagulation cascades, platelet activation, tricarboxylic acid cycle (TCA) cycle, and ferroptosis as pathways with the highest significance. Correlation with transcriptome datasets revealed a weak statistically significant positive correlation with 45% of the co-differentially expressed proteins/genes displaying the same regulation trend. The transcription levels of neurofilament light polypeptide (NEFL), dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex_mitochondrial (DLST), nitric oxide synthase 3 (NOS3), and ceruloplasmin (CP) were significantly increased in the RPL, consistent with the proteomics findings.

Conclusions and clinical relevance: Our data suggests alteration of several pathways as potential causes of idiopathic RPL from the fetal side and opens the way for investigations concerning clinical management.