Study And Functional Analysis Of Differential Expression Profiles Of MiRNAs In Dilated Cardiomyopathy

ObjectiveThis study used RNA-seq technology to research the differential expression profiles of mi RNAs in patients with dilated cardiomyopathy and healthy controls,and conduct func-tional analysis of differentially expressed mi RNAs by bioinformatics method,so as to elucidate the mechanism of the occurrence and development of dilated cardiomyopathy from the gene expression and gene regulation levels.MethodBlood samples for small RNA-sequencing were obtained from 10 typical patients with DCM and 10 healthy controls.Peripheral venous blood samples were collected in sterile tubes with ethylenediamine tetra acetic acid.Total RNA was isolated and enriched using Trizol~? reagent.The RNA library was constructed with ribosomal RNA-depleted RNAs using the Tru Seq Stranded Total RNA Library Prep kit.Paired-end reads were harvested from Illumina Hi Seq sequencer and quality controlled by Q30.Then the data analysis was performed using R software on the Novelbrain platform(https://cloud.novelbrain.com).The high-quality trimmed reads were aligned to the reference genome(Mi Rbase v22)guided by the Ensembl GTf gene annotation file with HISAT2 method.Then,the fold-change and P-values were calculated based on the mi RNAs counts using DESeq2 method,and differ-entially expressed mi RNAs were identified between the DCM group and control group.The criteria were set as fold-change≥2 or≤-2 and P-value<0.05 between two groups.Hier-archical clustering with average linkage was applied to calculate the distinguishable ex-pression patterns.Miranda database and RNAhybrid database were employed to predict the target m RNAs of dysregulated circulating mi RNAs in dilated cardiomyopathy.Finally,bioinformatics analysis was performed to elucidate the potential biological processes and signaling pathways associated with dilated cardiomyopathy.ResultSmall RNA-seq technology was applied to obtain the original data.After quality control,low expression removed and standardized treatment.A total of 48 dysregulated circulating mi RNAs were identified through the expression analysis,including 44 up-regulated mi RNAs and 4 down-regulated mi RNAs.A hierarchical clustering approach was employed to confirm the consistency of dysregulated micro RNAs in DCM and control serum.Miranda database and RNAhybrid database were employed to predict the target m RNAs of dysregulated circulating mi RNAs in dilated cardiomyopathy.Gene Ontology analysis were performed to identify the related biological processes of the predicted target m RNAs.GO-Tree network analysis was applied to reveal the hub biological processes associated with dilated cardiomyopathy,which included neuron differentiation,protein phosphorylation,cell migration and so on.Kyoto Encyclopedia of Genes and Genomes ana-lysis were performed to identify the related pathways of the predicted target m RNAs.Pathway-Act network was applied to reveal the hub pathways associated with dilated car-diomyopathy,including MAPK signaling pathway,regulation of actin cytoskeleton,PI3K-Akt signaling pathway,calcium signaling pathway,pathways in cancer and so on.ConclusionSmall RNA sequencing was employed to identify dysregulated circulating mi RNAs in dilated cardiomyopathy.GO analysis showed that the dysregulated mi RNAs participated multiple biological processes,and GO-Tree analysis disclosed that neuron differentiation was potentially the core biological process associated with dilated cardiomyopathy.KEGG analysis and Pathway-Act network showed that MAPK signaling pathway was the hub pathway in dilated cardiomyopathy.