Function Analysis Of Long Non-coding RNA In Down Syndrome And Human Early Embryos

Down’s syndrome(DS)is a disorder caused by nervous system developmental defect.Recent studies found epigenetics could play an important role in DS pathopoiesis.In this study,we analyze the functions of long non-coding RNA(lncRNA),which is an important epigenetics regulator,in DS and human early embryo development by the method combining the high-throughput sequencing and the bioinformatics.To begin with,Because DS has already formed in early embryo development,we analyzed the expression profiles and functions of lncRNAs in human early-stage embryos based on public single-cell RNA sequencing(RNA-seq)data.We found that lncRNAs were expressed in a developmental stage–specific manner during human early-stage embryonic development,and lncRNAs may regulate gene transcription in cis.Weighted gene co-expression network analysis(WGCNA)suggested that lncRNAs involved in human early-stage embryonic development were associated with several important functions and processes,such as oocyte maturation,zygotic genome activation.Most importantly,we found lncRNAs can regulate mitochondrial functions during blastocyst stage.Then the transcriptome profiles of the DS-iPSC(induced pluripotent stem cells)and Normal-iPSC were detected by RNA-sequencing.Through differential expression analysis,we found there are 3167 coding genes and 582 lncRNAs differetiallly expressed in DS-iPSC.Furthermore,we found that the expression levels of coding genes and lncRNAs were down-regulated in DS-iPSC.Meanwhile,we found that the abnormal expression of lncRNAs was far more than that of the coding genes.This result implied that the lncRNAs would be greatly influenced by an additional chromosome,which means that lncRNAs may play more important role in the pathogenesis of DS.By GSEA(Gene Set Enrichment Analysis)analysis,we discovered that the abnormal expression pattern of lncRNAs in DS may be related with the dysfunction of mitochondria.As the morphology,self-renewing capacity,and differentiation potential of iPSC are very similar to human embryonic stem cells which are located in blastocyte,the above results confirm that lncRNAs may involve in the pathopoiesis of DS by affecting the function of mitochondria.At last,PCR-array and qRT-PCR were conducted to confirm the results drawed from RNA-seq data analysis.The results showed that the expression of a large number of mitochondrial genes were down-regulated in DS-iPSC,while the abnormal expressed lncRNA NONHSAG002018 can interact with the abnormal expressed mitochondrial genes RHOT1 and NDUFA3 directly.