circRNAs May Be Involved in Dysfunction of Neutrophils of Type 2 Diabetic Mice through Regulation of Specific miRNAs.

Diabetes is known to delay wound healing, and this delay is attributed to prolonged inflammation. We found that microRNAs (miRNAs) might be involved in the dysfunction of diabetic-derived neutrophils, and dynamics of neutrophil and chronic inflammation might be initiated by miRNA-regulated genes. Moreover, studies of miRNA function in nephropathy have suggested that circular RNAs (circRNAs), which function as sponges of miRNA to regulate their expression, are potential biomarkers and new therapeutic targets for the diagnosis of diabetic nephropathy. Accordingly, to investigate the molecular mechanism of the regulation of inflammation in diabetic-derived neutrophils, we identified circRNAs in diabetic-derived neutrophils obtained from BKS.Cg- Dock7 m +/+ Lepr db /J ( Lepr db/db and Lepr db/+ ) mice using microarrays. Neutrophils from pooled bone marrow of three diabetic and three non-diabetic mice were isolated and total RNA was extracted. Microarray analysis was performed using the Arraystar Mouse Circular RNA Array. The results showed that three circRNAs were significantly increased and six circRNAs were significantly decreased in diabetic-derived neutrophils compared with non-diabetic-derived neutrophils. The expressions of some circRNAs in diabetic-derived neutrophils were more than double those in non-diabetic-derived neutrophils. The circRNAs contain binding sites of miRNAs, which were differentially expressed in diabetic-derived neutrophils. Our results suggest that circRNAs may be involved in the regulation of inflammation in diabetic-derived neutrophils.