Purpose: This study aimed to investigate the comprehensive differential expression profile of miRNAs by screening for miRNA expression in ischemic stroke and normal samples. Methods: Differentially expressed miRNA analysis was conducted by using limma R Bioconductor package. Target genes of differential expression miRNAs (DEMs) were identified from TargetScanHuman and miRTarBase databases. Functional enrichment analysis of the target genes was performed using clusterProfiler R Bioconductor package. The miRNA-based ischemic stroke diagnostic signature was constructed via logistic regression analysis. Results: Compared with the normal cohort, a total of 14 DEMs, including 5 upregulated miRNAs and 9 downregulated miRNAs, were identified in ischemic stroke patients. These DEMs have 1600 regulatory targets. Using a logistic regression model, the top 5 miRNAs were screened for constructing a miRNA-based ischemic stroke diagnostic signature. Using the miRNA–mRNA interaction pairs, two target genes (SP1 and AGO1) were speculated to be the primary genes of ischemic stroke. Discussion and Conclusion: Here, several potential miRNAs biomarkers were identified and a miRNA-based diagnostic signature for ischemic stroke was established, which can be a valuable reference for future clinical researches.

Alzheimer’s disease (AD) is a common neurodegenerative disease with high morbidity among elderly people. A genetic attribution has been extensively proved. Here, we propose to further prioritize genes that harbor single nucleotide variation (SNV) or structural variation (SV) for AD and explore the underlying potential mechanisms through exploiting their expression and methylation spectra. A high-confidence AD-associated candidate gene list was obtained from the ClinVar and Human Gene Mutation Database (HGMD). Genome-wide methylation and expression profiles of AD and normal subjects were downloaded from the Gene Expression Omnibus (GEO). Through comprehensive comparison of expression and methylation levels between AD and normal samples, as well as different stages of AD samples, SORL1 was identified as the most plausible gene for AD incidence and progression. Gene Set Enrichment Analysis (GSEA) revealed significant activation of the ABC (ATP binding cassette) transporter with the aberrant up-regulation of SORL1 within AD samples. This study unfolds the expression and methylation spectra of previously probed genes with SNV or SV in AD for the first time, and reports an aberrant activation of the ABC transporter pathway that might contribute to AD progression. This should shed some light on AD diagnosis and precision treatment.