〔Abstract〕 Objective To investigate the influences of circ＿WBSCR17 on high glucose-induced fibrosis and inflammation in human mesangial cells by regulating the miR-30a-5p/JAK1 axis. Methods Human mesangial cells HMCL were grouped into: NG group(5.5 mmol/L glucose-treated HMCL cells),HG group(30 mmol/L glucose-treated cells),si-NC group(30 mmol/L glucose+transfected with si-NC),si-circ＿WBSCR17 group(30 mmol/L glucose+transfected with si-circ＿WBSCR17),si-circ＿WBSCR17+inhibitor-NC group(30 mmol/L glucose+co-transfected with si-circ＿WBSCR17 and inhibitor-NC),and si-circ＿WBSCR17+miR-30a-5p inhibitor group(30 mmol/L glucose+co-transfected with si-circ＿WBSCR17 and miR-30a-5p inhibitor);RT-qPCR was performed to detect the expression of circ＿WBSCR17 and miR-30a-5p in cells; CCK-8 assay was performed to detect cell proliferation; flow cytometry was performed to detect apoptosis; ELISA was performed to detect the expression levels of tumor necrosis factor-α(TNF-α),interleukin(IL)-6 and IL-8;Western blot was performed to detect the expression of JAK1,proliferating cell nuclear antigen(PCNA),Bax, transforming growth factor-β1(TGF-β1),fibronectin(FN),collagen IV,and α-smooth muscle actin(α-SMA);distribution of WBSCR17 was detected by fluorescence in situ hybridization(FISH);dual-luciferase reporter gene experiment was performed to verify the relationship between circ＿WBSCR17 and miR-30a-5p, miR-30a-5p and JAK1,respectively. Results Compared with the NG group, the HMCL cell proliferation ability of the HG group decreased, the levels of TNF-α,IL-6 and IL-8,the protein expressions of p-JAK1/JAK1,p-STAT1/STAT1,p-STAT3/STAT3,TGF-β1,FN,collagenIV and α-SMA,and the apoptosis ability increased(P<0.05);compared with HG group and si-NC group, the expression of miR-30a-5p, OD450value and PCNA expression in HMCL cells of si-circ＿WBSCR17 group increased, the levels of TNF-α,IL-6 and IL-8,the expressions of circ＿WBSCR17,p-JAK1/JAK1,p-STAT1/STAT1,p-STAT3/STAT3,Bax, TGF-β1,FN,collagenIV and α-SMA decreased(P<0.05);inhibition of miR-30a-5p attenuated the promoting effect of knockdown of circ＿WBSCR17 on proliferation of HMCL cells, and enhanced apoptosis, cellular fibrosis and inflammatory responses; FISH experiment confirmed that WBSCR17 was mainly distributed in the cytoplasm; dual-luciferase reporter gene experiment confirmed that circ＿WBSCR17,JAK1 and miR-30a-5p had a targeted regulatory relationship. Conclusion Knockdown of circ＿WBSCR17 can reduce high glucose-induced fibrosis and inflammation in human mesangial cells by regulating the miR-30a-5p/JAK1 axis.