Identification of MicroRNA Profiles in Fetal Spina Bifida: The Role in Pathomechanism and Diagnostic Significance

Abstract

Distinct miRNA expression patterns may reflect anomalies related to fetal congenital malformations such as spinal bifida (SB). The aim of this preliminary study was to determine the maternal miRNA expression profile of women carrying fetuses with SB. Therefore, six women carrying fetuses with SB and twenty women with euploid healthy fetuses were enrolled in this study. Using NanoString technology, we evaluated the expression level of 798 miRNAs in both plasma and amniotic fluid samples. A downregulation of miR-1253, miR-1290, miR-194-5p, miR-302d-3p, miR-3144-3p, miR-4536-5p, miR-548aa + miR-548t-3p, miR-548ar-5p, miR-548n, miR-590-5p, miR-612, miR-627-5p, miR-644a, and miR-122-5p, and an upregulation of miR-320e, let-7b-5p, miR-23a-3p, miR-873-3p, and miR-30d-5p were identified in maternal amniotic fluid samples in SB when compared to the control group. The target genes of these miRNAs play a predominant role in regulating the synthesis of several biological compounds related to signaling pathways such as those regulating the pluripotency of stem cells. Moreover, the maternal plasma expression of miR-320e was increased in pregnancies with SB, and this marker could serve as a valuable non-invasive screening tool. Our results highlight the SB-specific miRNA signature and the differentially expressed miRNAs that may be involved in SB pathogenesis. Our findings emphasize the role of miRNA as a predictive factor that could potentially be useful in prenatal genetic screening for SB.

Keywords: biomarker; miR-320e; miRNA; prenatal screening; spina bifida.

Figure 1

The amniotic fluid assessment in SB pathogenesis identification. (A) DE miRNAs in amniotic fluid with significantly different expressions between SB (n = 6) and control group (n = 20) (|FC| > 1.5; FDR < 0.05); (B) the network of the top 10 hub genes; (C) gene ontology (GO) enrichment analysis. Top 10 significantly enriched GO (−log10 (p-value)) terms of the target genes in the cellular components, molecular function, and biological processes. KEGG, Kyoto Encyclopedia of Genes and Genomes.

Figure 2

ROC analysis was constructed to evaluate the diagnostic values of the selected miRNAs as predictive biomarkers of SB (FC > 1.5; FDR < 0.05): (A) miR-1253; (B) miR-1290; (C) miR-194-5p; (D) miR-302d-3p; (E) miR-3144-3p; (F) let-7b-5p; (G) miR-122-5p; (H) miR-23a-3p; (I) miR-30d-5p.

Figure 3

ROC analysis was constructed to evaluate the diagnostic values of the selected miRNAs in amniotic fluid as predictive biomarkers of SB (FC > 1.5; FDR < 0.05): (A) miR-320e; (B) miR-4536-5p; (C) miR-549aa + miR-548t-3p; (D) miR-548ar-5p; (E) miR-548n; (F) let-590-5p; (G) miR-612; (H) miR-627-5p; (I) miR-644a; (J) miR-873-3p.

Figure 4

The plasma analysis among SB pathogenesis identifications. (A) The DE miRNAs in plasma with significantly different expressions between SB (n = 6) and control group (n = 20) (FC > 1.5; FDR < 0.05); (B) the networks of the top 10 hub genes targeted by miR-320e; (C) gene ontology (GO) enrichment analysis. Top significantly enriched GO (−log10 (p-value)) categories of the target genes in the cellular components, and biological processes.

Figure 5

ROC analysis was conducted to evaluate the diagnostic value of miR-320e as diagnostic biomarker of SB vs. control.