Moyamoya disease-specific extracellular vesicle-derived microRNAs in the cerebrospinal fluid as revealed by comprehensive expression analysis through microRNA sequencing

We examined the specific changes that occur in the expression levels of extracellular vesicle (EV)-derived microRNAs (miRNAs) in intracranial cerebrospinal fluid (CSF) in moyamoya disease. Patients with arteriosclerotic cerebral ischemia were used as controls to eliminate the effects of cerebral ischemia. Comprehensive expression analysis of miRNAs extracted from EVs by next-generation sequencing (NGS) and validation by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed. Experiments were conducted on eight cases of moyamoya disease and four control cases. In the comprehensive miRNA expression analysis, 153 miRNAs were upregulated and 98 miRNAs were downregulated in moyamoya disease compared to the control (q-value  1). qRT-PCR performed on the four most valuable miRNAs (hsa-miR-421, hsa-miR-361-5p, hsa-miR-320a, and hsa-miR-29b-3p) associated with vascular lesions among the differentially expressed miRNAs gave the same results as miRNA sequencing. In GO analysis for the target genes, cytoplasmic stress granule was the most significant GO term. This study is the first comprehensive expression analysis of EV-derived miRNAs in the CSF of moyamoya disease patients using NGS. The miRNAs identified here may be related to the etiology and pathophysiology of moyamoya disease.