Plasma extrachromosomal circular DNA is a pathophysiological hallmark of short-term intensive insulin therapy for type 2 diabetes.

ABSTRACT

BACKGROUND: Extrachromosomal circular DNA (eccDNA) has emerged as a promising biomarker for disease diagnosis and prognosis prediction. However, its role in type 2 diabetes remains unexplored. OBJECTIVE: To investigate the characteristics and dynamics of circulating eccDNAs in newly diagnosed type 2 diabetes mellitus (T2DM) patients undergoing short-term intensive insulin therapy (SIIT), a highly effective treatment for inducing long-term glycemic remission. METHODS: We conducted Circle-Seq analysis on plasma samples from 35 T2DM patients at three time points pre-SIIT, post-SIIT, and 1-year post-SIIT. Our analysis encompassed the characterization of eccDNA features, including GC content, eccDNA length distribution, genomic distribution, and the genes in eccDNAs. RESULTS: Following SIIT, we observed an increase in plasma eccDNA load, suggesting metabolic alterations during therapy. Notably, a correlation was identified between eccDNA profiles and glycemia in T2DM, both quantitatively and genetically. Our analysis also revealed the frequent presence of metabolism-related genes within T2DM plasma eccDNAs, some of which spanned gene exons and/or fractions. CONCLUSION: This study represents the first report of cell-free eccDNA in T2DM and underscores a compelling association between cell-free eccDNA and profound glycemic changes. These findings highlight the potential of eccDNAs as crucial players in the context of T2DM and glycemic control.