Alternative Splicing Landscape of Placental Decidual Cells during Physiological Pregnancy

Alternative splicing (AS) of RNA is a key step in the post-transcriptional regulation of gene expression. It provides transcriptional plasticity and control of the expression of RNA isoforms in a certain type of tissues and cells at a given time. Presumably, this mechanism plays an important role in the development and functioning of the placenta. The study carried out deep whole-transcriptome sequencing with a detailed analysis of alternative splicing events in decidual cells (DC) of placental tissue during the physiological course of pregnancy. In decidual cells, 149 067 AS events annotated in GENCODE v.26 were identified in 20 463 genes; 4038 of these genes were characterized by ten or more isoforms. Analysis of the network of reconstructed genes demonstrated a high degree of interactions between alternatively spliced genes and revealed regulatory relationships that ensure the coordinated expression of most of the central genes associated with the initiation and elongation of translation in eukaryotes and modulation of angiogenesis and cell adhesion mediated by DE-cadherin. The results obtained confirm the importance of alternative splicing, which significantly increases transcriptional diversity and represents an important mechanism of gene regulation in decidual cells. It should be noted that a number of genes susceptible to AS in DC are associated with pregnancy complications, and therefore it seems relevant to further study this mechanism of RNA processing in a cohort of patients with obstetric pathology.