HK-2 cells cultured in vitro were divided into three groups: normal glucose group ( NG ), high glucose group( HG), and mannitol group(MG). The expression of angiotensin-converting enzyme( ACE ) and ACE2 mRNA in HK-2 cells was detected. The concentration of angiotensin Ⅱ ( Ang Ⅱ ) in the culture medium was detected. The mRNA and protein expression of ACE and ACE2 existed in normal cultured HK-2 ( NG group ). In comparison with NG group, the mRNA and protein expressions of ACE in HG group increased significantly ( P＜0. 01 ), and the expression of ACE2 mRNA decreased significantly( P＜0. 01 ). The level of Ang Ⅱ in HG group was significantly higher than in NG group( P＜0. 05 ). The result show that high glucose may induce ACE expression and inhibit ACE2 expression, then promote synthesis of Ang Ⅱ in proximal tubular cells.

Objective To investigate the efficacy of leflunomide combined with prednisone in the induction therapy of proliferative lupus nephritis (LN).Methods A prospective,multicenter,randomized controlled clinical trial was conducted in patients with biopsy-proved proliferative lupus nephritis recruited from 15 renal centers from 2013 to 2015.Patients were randomized to two groups.Oral leflunomide or intravenous cyclophosphamide was given to patients in each group.Both groups received a tapering course of oral prednisone therapy.All patients were followed up for 24 weeks.The blood biochemistry,urine index,clinical curative effect and adverse reaction were recorded and analyzed statistically.Results A total of 100 patients were enrolled in this clinical trial,including 48 patients in leflunomide group and 52 patients in cyclophosphamide group.After 24 weeks,the overall response rate was 79％ (95％ CI 67％-90％) in the leflunomide group and 69％ (95％ CI 56％-82％) in the cyclophosphamide group.23％ (95％CI 11％-35％) of patients in leflunomide group showed complete remission compared with 27％ (95％CI 24％-30％) in cyclophosphamide group (P=0.35).The levels of 24-hr urine protein excretion,SLEDAI and anti-dsDNA antibody titers were decreased in patients treated with leflunomide group after 24-weeks treatment.And the levels of serum albumin and complement 3 after treatment were significantly higher compared with these before treatment.There was also no significant difference in changes of 24-hr urine protein excretion,SLEDAI score,anti-dsDNA antibody titers,serum albumin and complement C3 levels after treatment between two groups.Incidence of adverse events did not differ between the leflunomide and cyclophosphamide group.Conclusions Leflunomide combined with prednisone showed same efficacy compared with cyclophosphamide as induction therapy for lupus nephritis.Leflunomide might be an useful medicine in the induction therapy of lupus nephritis.