Could microRNAs be biomarkers for neural tube defects?

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

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.

MicroRNA biomarkers for early detection of embryonic malformations in pregnancy

Congenital birth defects, manifested in newborn infants, are formed during early embryogenesis. Targeted and individualized interventions to prevent birth defects require early detection of risk and signs of developmental abnormalities. Current diagnosis of structural anomalies largely relies on ultrasonography, which can only detect abnormities after their formation in fetuses. Biomolecules, mainly proteins, in maternal blood have been used as indicators of fetal anomalies; however, they lack adequate sensitivity for detecting embryonic malformations. Recently, cell-free microRNAs (miRNAs) have been found in blood and evaluated as biomarkers for diseases. Expression of certain miRNAs in maternal plasma has been shown to be correlated with birth defects in infants. Although their reliability and sensitivity remain to be validated, miRNAs, which can be amplified and sequenced, are potentially sensitive and specific biomarkers for early embryonic dysmorphogenesis.