MicroRNA expression, target genes, and signaling pathways in infants with a ventricular septal defect

Deep sequencing unveils altered cardiac miRNome in congenital heart disease

Congenital heart disease (CHD) surges from fetal cardiac dysmorphogenesis and chiefly contributes to perinatal morbidity and cardiovascular disease mortality. A continual rise in prevalence and prerequisite postoperative disease management creates need for better understanding and new strategies to control the disease. The interaction between genetic and non-genetic factors roots the multifactorial status of this disease, which remains incompletely explored. The small non-coding microRNAs (miRs, miRNAs) regulate several biological processes via post-transcriptional regulation of gene expression. Abnormal expression of miRs in developing and adult heart is associated with anomalous cardiac cell differentiation, cardiac dysfunction, and cardiovascular diseases. Here, we attempt to discover the changes in cardiac miRNA transcriptome in CHD patients over those without CHD (non-CHD) and find its role in CHD through functional annotation. This study explores the miRNome in three most commonly occurring CHD subtypes, namely atrial septal defect (ASD), ventricular septal defect (VSD), and tetralogy of fallot (TOF). We found 295 dysregulated miRNAs through high-throughput sequencing of the cardiac tissues. The bioinformatically predicted targets of these differentially expressed miRs were functionally annotated to know they were entailed in cell signal regulatory pathways, profoundly responsible for cell proliferation, survival, angiogenesis, migration and cell cycle regulation. Selective miRs (hsa-miR-221-3p, hsa-miR-218-5p, hsa-miR-873-5p) whose expression was validated by qRT-PCR, have been reported for cardiogenesis, cardiomyocyte proliferation, cardioprotection and cardiac dysfunction. These results indicate that the altered miRNome to be responsible for the disease status in CHD patients. Our data expand the existing knowledge on the epigenetic changes in CHD. In future, characterization of these cardiac-specific miRs will add huge potential to understand cardiac development, function, and molecular pathogenesis of heart diseases with a prospect of epigenetic manipulation for cardiac repair.

Construction of the amniotic fluid-derived exosomal ceRNA network associated with ventricular septal defect

Ventricular septal defect (VSD) is the most frequent congenital cardiac malformations. Amniotic fluid (AF) contains a higher abundance of biological compounds that could reflect fetal health information. The aims of our study were to construct a competitive endogenous RNA (ceRNA) network based on AF-derived exosomal ncRNAs. We conducted whole transcriptome profiling in six pairs of AF-derived exosomes from VSD fetuses and matched healthy controls. A total of 1252 differentially expressed (DE) mRNAs, 256 DE-miRNAs and 1090 DE-lncRNAs were found to be significantly altered in the VSD group. We constructed a ceRNA regulatory network including 46 mRNAs, 11 miRNAs and 47 lncRNAs. The expression level of 6 hub RNAs were validated using qRT-PCR. In conclusion, AF-derived exosomal VSD-related ceRNAs provide a basis for a better understanding of the role of ncRNAs in the pathogenesis and mechanisms of VSD, which may lead to the discovery of potential diagnostic biomarkers for fetal VSD.