Expression of hsa_circ_0007240 in peripheral blood leucocytes and correlated with inflammatory factor in patients with type 2 diabetes mellitus

Abstract

Objective To investigate the expression levels of circRNAs in peripheral blood leucocytes and identify the correlation of circRNAs and inflammation factors in type 2 diabetes mellitus (T2DM) patients. Methods The fresh blood samples of 5 patients with T2DM and 5 healthy controls were collected for RNA sequencing (RNAseq). The peripheral blood from 62 patients with T2DM, 56 age-and gender-matched healthy controls (collected at the Beijing Hospital from June 2017 to December 2017) were chosen and collected. Then RNA of peripheral leukocytes was extracted and performed with reverse transcription PCR to detect the level of circRNA. The protein levels of interleukin 6 (IL-6), C-reactive protein (CRP) and tumor necrosis factor (TNF)-α inflammatory factors were detected by enzyme-linked immunosorbent assay. The correlation of circRNA level and the inflammatory factor level was identified. Data were analyzed using Mann-Whitney test, Student′s t-test and Pearson correlation accordingly. Results A total of 970 circRNAs were found to be differentially expressed in T2DM patients compared with the normal individuals (428 circRNAs were significantly up-regulated, 542 circRNAs were significantly down-regulated). The high expression level of hsa_circ_0007240 was further identified in the RNAseq samples. The basic RNA level of hsa_circ_0007240 in peripheral leukocytes was also significantly higher in T2DM patients compared to healthy controls in large sample test (Z=-3.422, P<0.001). The protein levels of IL-6, CRP and TNF-α were also significantly different between T2DM group and control group [(12.33±3.96) vs (9.72±2.92) μg/L, (13.34±3.99) vs (9.91±2.75) μg/L, (18.37±4.64) vs (13.73±3.07) μg/L, t=2.370, 3.167, 3.731, respectively, all P<0.05]. The expression level of hsa_circ_0007240 was positive correlated with IL-6 (r=0.596, P=0.006). Conclusion The expression level of hsa_circ_0007240 is significantly up-regulated and positive correlated with IL-6 inflammatory factor in peripheral blood leucocytes T2DM patients. Hsa_circ_0007240 can be used as potential biomarker of inflammatory T2DM. Key words: Diabetes mellitus, type 2; Inflammation; CircRNA