Screening And Preliminary Functional Analysis Of MicroRNAs Expression Profiles Of Peripheral Blood Mononuclear Cells In Early-onset Familial Alzheimer's Disease

Background and Aims:Alzheimer's Disease(AD)is one of the most common neurodegenerative diseases,characterized by amyloid deposition of senile plaques,Neurofibrillary tangles(NFT)formed by tau protein over-phosphorylation,and loss of neurons.The onset of AD is insidious,and the pathogenesis is not completely clear,especially the relatively insufficient understanding of early AD.AD can be divided into sporadic AD(Sporadic Alzheimer's diseases,SAD)and Familial AD(Familial Alzheimer's diseases,FAD),clinical go up to see more SAD.AD can be artificially divided into asymptomatic preclinical stage and dementia stage,and the transition between these two stages is a continuous process.Therefore,members of the FAD family are the ideal population to observe the preclinical stage of AD and the development of AD.Micro RNAs(Mi RNAs)are single-stranded non-coding small RNAs with the size of about 18-25 nucleosides and the function of post-transcriptional gene regulation.Mi RNAs and AD have been widely studied,but few studies have been conducted on FAD and Mi RNAs.This experiment with Illumina sequencing technology for PSEN1 gene p.G 378 E mutations cause early-onset familial Alzheimer's disease(EOFAD)in patients with peripheral blood mononuclear cell line mi RNAs expression spectrum detection,target gene prediction and parallel preliminary function analysis,to explore the mechanism of action of mi RNAs in EOFAD,for understanding of mi RNAs in the pathogenesis of AD and the AD process of occurrence and development to offer help.Methods:Two patients with EOFAD and two normal controls were selected and 4ml of their peripheral blood was extracted respectively.Lymphocyte analysis solution was used for mononuclear cell isolation,total RNA was extracted and mi RNAs were isolated.Illumina Hi Seq 2500 sequencing technology was applied to detect the expression profile of mi RNAs in peripheral blood mononuclear cells of patients with EOFAD and normal controls,and to analyze and screen out mi RNAs with differential expression.Through the search for mi Randa database and Target Scan database,the target genes differentially expressed mi RNAs projections,search for each database predicted target genes,respectively,and then summarize the results of the two databases are common target genes(m RNAs).Functional annotation of predicted target genes was conducted according to GO database and KEGG database,so as to screen out significant sexual function and significant pathway reflected by different genes.Results:There were 142 differentially expressed mi RNAs in peripheral blood mononuclear cells of patients with EOFAD and normal controls,of which 90up-regulated mi RNAs and 52 down-regulated mi RNAs(p<0.05,FC>1.2 or FC<0.833).If differential gene screening was conducted with p value <0.05,FC>2 or FC<0.5,there were 121 mi RNAs,including 76 up-regulated mi RNAs and 45 down-regulated mi RNAs,among which hsa-mi R-3614-3p,hsa-mi R-193a-5p,hsa-mi R1-3p,hsa-mi R-206,hsa-mi R-27a-5p,etc.A total of768 target genes were obtained by predicting target genes in mi Randa database and Target Scan database and summarizing the results.GO analysis of predicted target genes showed that the first three significant GO's of up-regulated target genes predicted by mi RNAs in EOFAD group and NC group were as follows:cell-substrate junction,focal adhesion,cell-substrate adhesion junction;The significance of the first five down-regulated target genes predicted by mi RNAs in EOFAD group and NC group went as follows: m RNA catabolic process,focal adhesion,cell-s-ubstrate adherens junction,cell-substrate junction,cadherin binding.In addition to participating in the above functions,target genes are also related to physiological processes such as m RNA catabolic process,RNA catabolic process,positive regulation of cell cycle and wnt signaling pathway and other function.KEGG analysis of predicted target genes showed that the first three significant pathways of up-regulated mi RNAs predicted target genes in EOFAD group and NC group were proteoglycan pathways,cell senescence pathways and prostate cancer pathways in cancer.The first three significant pathways of down-regulated target genes predicted by mi RNAs in EOFAD group and NC group were viral oncogenic pathway,proteoglycan pathway in cancer,and thyroid hormone signaling pathway.In addition to the above signaling pathways,target genes are also involved in neurotrophic factor signaling pathways,Fox O signaling pathways,MAPK signaling pathways,Wnt signaling pathways,Ras signaling pathways,cell aging,cell cycle and other pathways.Conclusion:High-throughput sequencing is an effective method to detect the expression profile of mi RNAs in peripheral blood mononuclear cells in patients with EOFAD.Compared with normal people,patients with EOFAD have significantly differentially expressed mi RNAs,among which hsa-mi R-3614-3p,hsa-mi R-193a-5p,hsa-mi R-1-3p,hsa-mi R-206,hsa-mi R-27a-5p and other mi RNAs have significant differentially expressed mi RNAs.These mi RNAs may participate in the decomposition of m RNA catabolic process,RNA catabolic process,positive regulation of cell cycle.Also,these mi RNAs may participate in neurotrophin signaling pathways,Fox O signaling pathways,MAPK signaling pathways,Wnt signaling pathways,Ras signaling pathways,cell aging,cell cycle such as signaling pathways involved the onset of EOFAD.