Transcriptome-wide N6-methyladenosine methylation dynamic profile in type 1 diabetes progression.

Aims: To map transcriptome-wide N6-methyladenosine (m6A) profile at different stages of type 1 diabetes (T1D).

Materials & methods: RNA extracted from islet tissues of non-obese diabetic mice at different ages (4-week-old control group, 8-week-old pre-diabetes group, and 14-week-old diabetes group) was analyzed by MeRIP-seq and mRNA-seq. Bioinformatics analyses, including m6A motif enrichment, differential methylation, gene ontology and pathway analysis.

Results: Bioinformatic analysis revealed a progressive increase in m6A methylation sites and unique peaks throughout diabetes progression. The predominant m6A motif was "GGACU" in the control and pre-diabetes stages, shifting to "GGACU/A" in the diabetes stage. m6A modifications were primarily enriched at the start codon, coding region, and stop codon. Integrated analysis found pre-diabetes, diabetes groups showed distinct m6A and mRNA changes versus control. Pathway analysis indicated that differentially expressed mRNAs with m6A methylation were predominantly enriched in insulin/IGF-MAPKK/MAPK cascades, apoptosis, T-cell activation, interleukins, CCKR, and inflammation-related pathways in the pre-diabetes stage. As diabetes progressed, additional pathways, including Wnt, EGF receptor, PDGF, GnRH receptor, and angiogenesis, became involved in disease development. In vitro, cytokine stimulation of INS-1 cells increased m6A methylation, upregulated METTL3, downregulated ALKBH5.

Conclusions: m6A methyl group dynamics in T1D disease progression, potentially influencing mRNA expression and signal transduction pathways.