Investigation Of Angptl4in Human Podocyte Injury-related Disease

Background:Membranous nephropathy (MN, membranous nephropathy) and minimal change nephropathy (MCN, minimal change nephropathy) were the most common pathological type in adults and children with nephrotic syndrome, which are based on massive proteinuria, low serum albumin, edema, and hyperlipidemia as the main characteristics. Effaced foot process occurs in both of the two pathological types. Long-term proteinuria has a great impact on the prognosis of patients with kidney disease. In recent years, studies in rats with MCD have found that expression of angiopoietin-like4(Angptl4) was significantly increased in kidney tissue of MCD rat, compared with other pathological types of nephrotic syndrome.Aims:To investigate changes of Angptl4protein in patients with podocyte injury and non-podocyte injury.Methods:We classified72podocyte injury patients with nephrotic syndrome as the NS group,64podocyte injury patients without nephrotic syndrome as the non-NS group,37patients with IgA nepropathy as IgAN group and60healthy volunteers as the control group. Plasma, urine and renal tissue paraffin samples were collected for further study. Angptl4protein expression in plasma and urine were measured using enzyme-linked immunosorbent assay (ELISA). And the data was carried out by SPSS. The expression of Angptl4in kidney biopsy tissue was determined by immunohistochemical assay.Results:There was significant difference among the plasma Angpt14OD values of NS group, non-NS group, IgAN group and Control group (NS:1.296±0.634; non-NS:1.469±0.546; IgAN:1.731±0.387; Control:2.142±0.416). According to the urine albumin/creatinine of IgAN group patients, they were divided into three groups (0-0.5g/g vs0.5∽3.5g/g vs3.5∽g/g).The OD values of plasma Angptl4among them was significantly different (1.875±0.381vs1.694±0.324vs1.016±0.098). Linear correlation analysis showed there were no significant correlation between plasma Angpt14OD value and urine albumin/creatinine, urinary protein concentration, GFR and Scr in NS group. In IgAN group, there were negative correlation between plasma Angpt14OD value and urine albumin/creatinine, urinary protein concentration.There was significant difference among the urinary Angptl4OD values of NS group, non-NS group, IgAN group and Control group (NS:2.830±0.340; non-NS group:2.456±0.770; IgAN:1.569±0.810; Control:0.163±0.270). Linear correlation analysis showed there were no significant correlation between urinary Angpt14OD value and urine albumin/creatinine, urinary protein concentration, GFR and Scr in NS group. In IgAN group, there were positive correlation between plasma Angpt14OD value and urine albumin/creatinine, urinary protein concentration.The immunohistochemistry results showed, the Angpt14staining on podocytes were positive in NS group and the non-NS group.Conclusions:There are differences in plasma, urine and kidney tissue expression of Angpt14among NS group, non-NS group, IgAN group and Control group. Angpt14specifically expressed in podocyte injury patients with nephrotic syndrome, and it can be concluded that the protein may plays an important role in the pathophysiological processes of podocyte injury.