Transcriptome-wide RNA m6A methylation profiles in an endemic osteoarthropathy, Kashin-Beck disease.

Kashin-Beck disease (KBD) is a chronic degenerative, disabling disease of the bones and joints and its exact aetiology and pathogenesis remain uncertain. This study is to investigate the role of m6A modification in the pathogenesis of KBD. Combined analysis of m6A MeRIP-Seq and RNA-Seq were used to analyse human peripheral blood samples from three KBD patients and three normal controls (NC). Bioinformatic methods were used to analyse m6A-modified differential genes and RT-qPCR was performed to validate the mRNA expression of several KBD-related genes. The results indicated that the total of 16,811 genes were modified by m6A in KBD group, of which 4882 genes were differential genes. A large number of differential genes were associated with regulation of transcription, signal transduction and protein binding. KEGG analysis showed that m6A-enriched genes participated the pathways of Vitamin B6 metabolism, endocytosis and Rap 1 signalling pathway. There was a positive association between m6A abundance and levels of gene expression, that there were 6 hypermethylated and upregulated genes (hyper-up), 23 hypomethylated and downregulated genes (hypo-down) in KBD group compared with NC. In addition, the mRNA expression of levels of MMP8, IL32 and GPX1 were verified and the protein-protein interaction networks of these key factors were constructed. Our study showed that m6A modifications may play a vital role in modulating gene expression, which represents a new clue to reveal the pathogenesis of KBD.