Potential Significance of Circular RNA in Human Placental Tissue for Patients with Preeclampsia.

Aims: This study aimed to identify the different expression of circular RNAs (circRNAs) in the placental tissues of pregnant women with preeclampsia (PE) and to provide a new avenue of research regarding the pathological mechanisms of PE.

Methods: In this study, we collected 40 placental tissues from PE patients and 35 placental tissues from gestational age-matched patients who gave premature birth. Arraystar circRNA Microarray Technology (KANGCHEN, Shanghai, China) was used to analyze the differential expression of circRNAs. According to the basic content of circRNAs in the two groups and their fold changes and due to the practicability of the designed divergent primers of each candidate circRNA, we selected three up-regulated circRNAs, hsa_circRNA_100782, hsa_circRNA_102682 and hsa_circRNA_104820, to validate the data. Real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was utilized to estimate the Ct values in both groups. We further evaluated the differences with a paired t-test and a receiver operating characteristic (ROC) curve.

Results: Many circRNAs were found to be differentially expressed in PE placental tissues versus their controls; of these, 143 circRNAs were up-regulated and 158 were down-regulated. The expression levels of hsa_circRNA_100782 (p < 0.05), hsa_circRNA_102682 (p < 0.05), and hsa_circRNA_104820 (p < 0.0001) were validated as significantly up-regulated in the experimental group compared with the controls. Finally, we performed a literature comparison to forecast the possible mechanisms of circRNA function during PE.

Conclusion: circRNA expression significantly differed in placental PE tissues compared with controls. According to the circRNA microarray results and the existing papers, circRNAs may contribute to the pathogenesis of PE by acting as miRNA sponges; this possibility requires additional investigation in future studies.