Abstract: Objective To investigate the expression changes of hsa_circ_0017650 in the human adipocyte differentiation process and adipose tissue of obese people. Methods The changes of hsa_circ_0017650 on the 0th, 1st, 3rd, 5th, 7th, 9th and 12th days of human preadipocyte differentiation were determined by RT-qPCR; Oil Red O staining was performed to observe the formation of lipid droplets on 0th, 6th, and 12th days of human preadipocyte differentiation. The mRNA levels of CCAAT enhancer-binding protein α (C/EBPα), fatty acid-binding protein 4 (FABP4/ap2), and lipoprotein lipase (LPL) in human preadipocytes were determined by RT-qPCR to identify the differentiation of human preadipocytes. A total of 125 patients who underwent appendectomy in our hospital were selected as research subjects, and were divided into obesity group (53 cases) and control group (72 cases) according to body mass index (BMI). The expression differences of hsa_circ_0017650 in retroperitoneal white adipose tissue of the two groups were compared. The Pearson’s correlation coefficient between the expression level of hsa_circ_0017650 and BMI, triacylglycerol (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) in obesity group was analyzed. Results Human preadipocytes gradually changed from spindle to oval or round, with a gradual increase in volume and an increase in fat droplets. On the 12th day of culture the levels of C / EBPα, FABP4/ap2 and LPL in human precursor adipocytes were higher than those on day 0 (P<0.001). Compared with baseline of day zero(1.02±0.13), the expression of hsa_circ_0017650 increased on the 1st (2.47±0.30), 3rd (27.38±3.42), 5th (15.62±1.95), 7th (16.24±2.03), 9th (18.37±2.29) and 12th (16.24±2.21), and reached the peak on the 3rd day (P<0.001). Compared with the control group, the levels of BMI, waist-to-hip ratio, TC, TG, LDL-C and of hsa_circ_0017650 in white adipose tissue increased in the obesity group (P<0.001); Hsa_circ_0017650 was positively correlated with BMI, TG, and LDL-C (r=0.554, 0.569, 0.618, P<0.001). Conclusions Hsa_circ_0017650 is highly expressed during human adipocyte differentiation and mainly in white adipose tissue of obese individual.It is closely related to obesity and is potential for the treatment of obese patients.

Key words: human preadipocytes, differentiation, obesity, hsa_circ_0017650