Identification and functional analysis of circulating small extracellular vesicle lncRNA signatures in children with fulminant myocarditis.

Fulminant myocarditis (FM) is the most serious type of myocarditis. However, the molecular mechanism underlying the pathogenesis of FM has not been fully elucidated. Small extracellular vesicles (sEVs) play important roles in many diseases, but any potential role in paediatric FM has not been reported. Here, the differential signatures of lncRNAs in plasma sEVs were studied in FM children and healthy children using transcriptome sequencing followed by functional analysis. Then immune-related lncRNAs were screened to study their role in immune mechanisms, the levels and clinical relevance of core immune-related lncRNAs were verified by qRT-PCR in a large sample size. Sixty-eight lncRNAs had increased levels of plasma sEVs in children with FM and 11 had decreased levels. Functional analysis showed that the sEVs-lncRNAs with different levels were mainly related to immunity, apoptosis and protein efflux. Seventeen core immune-related sEVs-lncRNAs were screened, functional enrichment analysis showed that these lncRNAs were closely related to immune activation, immune cell migration and cytokine pathway signal transduction. The results of the study show that sEVs-lncRNAs may play an important role in the pathogenesis of fulminant myocarditis in children, especially in the mechanism of immune regulation.