CircRNA-0004904, CircRNA-0001855, and PAPP-A: Potential Novel Biomarkers for the Prediction of Preeclampsia.

Circular RNAs (circRNAs) are transcribed prevalently in the genome; however, their potential roles in multiple cardiovascular diseases, particularly preeclampsia (PE), are not yet well understood. This study investigated the expression profiles of circRNAs and explored circRNA-mediated pregnancy-associated plasma protein A (PAPP-A) expression as a potential biomarker for PE before 20 weeks of pregnancy. A nested case-control two-phase screening/validation study was performed in pregnant women before 20 weeks of gestation (before clinical diagnosis) at Guangzhou Women and Children's Medical Center from 2012 to 2015. In the screening phase, circRNA expression profiles of blood cells were assessed using a human circRNA microarray, which was designed to detect simultaneously 5396 circRNAs, in 5 patients with PE and 5 age- and gestational week-matched controls. In the validation phase, 18 circRNAs in blood cells predicted by bioinformatics tools were validated by quantitative reverse transcription PCR in a cohort of 60 patients (PE and age-, gestational week-, and sample storage time-matched controls). Then, we examined the involvement of circRNAs in PE-related pathways via interactions with miRNAs by multiple bioinformatics approaches. Bioinformatics analysis predicted that hsa_circ_0004904 and hsa_circ_0001855 miRNA sponges directly target PAPP-A. PAPP-A was verified in the serum of the same cohort of patients using an enzyme-linked immunosorbent assay. Finally, we combined PAPP-A with circRNAs to create a novel preclinical diagnostic model for PE with logistic regression and evaluated the efficiency of this model with receiver operating curve analysis. Volcano plot analysis using various parameters showed that circRNAs were differentially expressed among both groups (P < 0.01, fold change > 2). In the screening phase, we found that 2178 circRNAs were differentially expressed between the control and PE groups, in which 884 circRNAs were downregulated and 1294 circRNAs were upregulated in the PE group compared with the control group. In the validation phase, two circRNAs, hsa_circ_0004904 and hsa_circ_0001855, were significantly upregulated in PE patients compared with healthy pregnant women (P < 0.05). PAPP-A expression levels, related to the two circRNAs based on bioinformatics prediction, were increased in the PE group compared with the control group. The area under the curve of the combined model was 0.94 in the predicted PE subjects. This is the first study to report circRNA profiling in patients with PE prior to the onset of symptoms. Our data suggested that hsa_circ_0004904 and hsa_circ_0001855 combined with PAPP-A might be promising biomarkers for the detection of PE. Moreover, circRNAs may provide new insights into the potential mechanisms underlying the pathophysiology of PE.

Jiang M ，Lash GE ，Zhao X ，Long Y ，Guo C ，Yang H ... -  《-》

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

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. 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. 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. 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.

Qian Y ，Lu Y ，Rui C ，Qian Y ，Cai M ，Jia R ... -  《-》

Competing endogenous RNA expression profiling in pre-eclampsia identifies hsa_circ_0036877 as a potential novel blood biomarker for early pre-eclampsia.

Hu X ，Ao J ，Li X ，Zhang H ，Wu J ，Cheng W ... -  《-》

Circular RNA expression profiling identifies hsa_circ_0011460 as a novel molecule in severe preeclampsia.

To identify circRNA expression profiles in the placentae of severe preeclampsia (SPE) and normal pregnant (NP) women. Placental samples were collected from six paired SPE and NP women. CircRNA expression profiles were identified by RNA-Seq and validated in another 30 SPE and NP samples by qRT-PCR. Several bioinformatic tools were utilised to analyse the potential function of differentially expressed circRNAs (DE-circRNAs) and to predict target microRNAs (miRNAs) and proteins. Furthermore, immunohistochemistry, Western blotting and RNA binding protein immunoprecipitation (RIP) were conducted to confirm the interaction between the circRNA and protein. In total, 18,631 circRNAs were detected. Among them, 180 circRNAs were differentially expressed, including 94 upregulated and 86 downregulated circRNAs. Seven DE-circRNAs were selected for validation, and the results of six circRNAs (hsa_circ_0007611, hsa_circ_0011460, hsa_circ_0002888, and hsa_circ_0007445, hsa_circ_0017068, hsa_circ_0012737) were consistent with the sequencing results. Bioinformatics analyses of DE-circRNAs revealed that most of them are involved in vasodilation, regulation of blood vessel size, protein transport and localization, and pathways in cancer. In addition to the mRNA expression profile, it was interesting to find that the hsa_circ_0011460 target gene solute carrier organic anion transporter family member 2A1 (SLCO2A1, PGT) was also significantly increased in SPE placentae. Immunohistochemistry, Western blotting and qRT-PCR validated the expression and distribution of PGT. Finally, RIP of HTR-8/SVneo cells confirmed that hsa_circ_0011460 targets PGT directly. A total of 180 DE-circRNAs were detected. One crucial circRNA, hsa_circ_0011460, was shown to interact directly with its host gene PGT. These findings indicated that hsa_circ_0011460 may serve as a potential therapeutic target for patients with SPE.

Deng N ，Lei D ，Huang J ，Yang Z ，Fan C ，Wang S ... -  《-》

Microarray Expression Profile of Circular RNAs in Plasma from Primary Biliary Cholangitis Patients.

Circular RNAs (circRNAs) play a crucial role in the occurrence of several diseases, including autoimmune diseases. However, their role in primary biliary cholangitis (PBC) remains unclear. Here, we aimed to determine the circRNA expression profile in plasma from PBC patients and further explore the value of circRNA in diagnosing PBC. CircRNA microarrays were used to determine circRNA expression profiles in plasma samples from 6 PBC patients and 6 healthy controls. Statistical analyses identified differentially expressed circRNAs, and these circRNAs were verified by qRT-PCR in 29 PBC patients and 30 healthy controls. MicroRNA (miRNA) target prediction software identified putative miRNA response elements (MREs), which were used to construct a map of circRNA-miRNA interactions for the differentially expressed circRNAs. Our results indicated that there were 18 up-regulated and 4 down-regulated circular RNAs in the plasma from PBC patients compared with that from healthy individuals. Among the differentially expressed circRNAs, hsa_circ_402458 (P=0.0033), hsa_circ_087631 and hsa_circ_406329 (P=0.0185) were up-regulated, and hsa_circ_407176 (P=0.0066) and hsa_circ_082319 were down-regulated in the PBC group versus the healthy group as demonstrated by qRT-PCR. In particular, hsa_circ_402458 was significantly higher in PBC patients not receiving UDCA treatment than in PBC patients receiving UDCA treatment (P=0.0338). The area under the receiver operating characteristic curve for hsa_circ_402458 for diagnosing PBC was 0.710 (P=0.005). For hsa_circ_402458, two putative miRNA targets, hsa-miR-522-3p and hsa-miR-943, were predicted. circRNA dysregulation may play a role in PBC pathogenesis, and hsa_circ_402458 shows promise as a candidate biomarker for PBC.

Zheng J ，Li Z ，Wang T ，Zhao Y ，Wang Y ... -  《-》