The Expression And Significance Of CD2AP And WT1 In Glomeruli Of Patients With Primary Nephrotic Syndrome

Objective:Nephrotic syndrome (NS) manifests itself in massive proteinuria, hypoalbuminemia, edema and hyperlipidemia. The integrated structure and function of the slit diaphragm(SD) is particularly critical for the occurrence of proteinuria. CD2AP (CD2 associated protein) is a kind of protein located in SD which is related with cytoskeleton assembly, cell signal transduction and apoptosis of podocyte. Wilms'tumor 1 (WT1) as a transcription regulatory factor plays an important role in the maintenance of normal podocyte function.Our study is to investigate the expression and distribution of CD2AP and WT1 (by immunohistochemistry) in glomeruli of patients with primary nephrotic syndrome, and to carry out the relative researches with trial index commonly used in24-hour urinary protein ,serum creatinine, glomerular sclerosis rate, so as to discuss the possible effect of CD2AP and WT1 in the occurrence of proteinuria.Methods:(1)Eighty patients diagnosed as primary nephrotic syndrome were involved in this study with an average age (39.64±16.3 years), 50 cases of male, 30 cases of female。Based on pathological classification all patients are divided into four group(s20 cases in each group) :glomerular minimal change group (MCN), IgA nephropathy group (focal proliferative sclerosing IgA nephropathy in 8 patients, mild mesangial proliferative IgA nephropathy in 11 cases, severe mesangial proliferative IgA nephropathy in 1 patients), membranous nephropathy group (18 cases in phaseⅠ, 2 cases in phase 2), focal segmental glomerulosclerosis group (2 cases of the top type, 2 cases of umbilical-based, 16 cases of non-special-type).(2)10 specimens of renal tissue in patients with normal renal tissue remote carcinoma(5 cases of male, 5cases of female)formed the control group(.3)Collected urine and serum samples, measured 24-hour urinary protein, serum creatinine, serum albumin.CD2AP and WT1 expression index (EI) are detected by Motic Med 6.0 image analysis system.Counting the glomerular sclerosis rate by glomerular light microscopy (the number of sclerotic glomeruli / the total number of glomerular×100%).(4)The estimates of CD2AP and WT1 expression were mathematically analysed to examine changes of both markers in the various glomerulopathies. And differences between groups were evaluated by one-way analysis of variance test. To determine the significance between group means in the analysis of variance, the nearest significant difference test (SNK-q test) was used as the multiple comparison test. Correlation analysis was processed between immunohistochemical result and clinical index.(5): SPSS 16.0 statistical software is used to analyze the above-mentioned data, in which process the significance was set at p<0.05.Results:1.The expression of CD2AP in glomerruli:In control group, the distribution of CD2AP showed an even and linear pattern along the glomerular capillary wall. Staining in some regions apparently decreased and the linear pattern disappeared in some regions showing more granular in nephrotic syndrome group. There was expression deletion at the lesions regional.The EI of CD2AP in control group and MCN Group, IgAN group,MN group, FSGS group respectively were (14.35±3.29)(11.69±3.36),(11.84±4.37),(7.67±3.06),(8.71±3.06).There were sinificantly diminution as compareing MN group FSGS group with control group in CD2AP expressian(p<0.05)and no significant difference was found as compareing MCN group, IgAN group with the control group .The expression of CD2AP in MCN group, IgAN group was significantly higher than the MN group and FSGS group (p <0.05).2.The expression of WT1 in glomeruli :WT1 in the control group was uniformly distributed along the glomerular capillary wall.The expression of WT1 in MCN Group, FSGS group ,IgAN group was intensity decreased and there was expression deletion in lesion regional of IgAN group.The EI of WT1 in control group and MCN Group, IgAN group, MN group, FSGS group respectively were (3.51±0.51),(2.54±0.85),(2.45±0.57),(3.71±1.08),(1.93±0.31).WT1 expressions of MCN group, IgA group and FSGS group decreased compared with that of the control group (p<0.05) and no difference as compareing MN group with the control group.Differences were not fined between the nephrotic syndromegroup (p > 0.05).3. The correlation between clinical data and EI : The expressions of CD2AP and WT1 were correlated negatively with 24-hour urine protein quantitation(r =-0.861,-0.304 p <0.05). No relationship was found between their expressions and serum creatinine,the rate of glomerular sclerosis .Conclusion:1. CD2AP was specificly expressed mainly in glomerruli.In control group, the distribution of CD2AP showed an even and linear pattern along the glomerular capillary wall.Staining in some regions apparently decreased and the linear pattern disappeared in some regions showing more granular in nephrotic syndrome group.The expression of MN group and FSGS group decreased significantly compared with that of the control group.The CD2AP expression in glomerruli has negative correlation with 24-hour urinary protein and no correlation with serum creatinine and the rate of glomerular sclerosis.2.The expressian of WT1 in MCN group,IgAN group,FSGS group was sinificantly decreased as compared with control group.The WT1 expression level in glomerruli has negative correlation with 24-hour urinary protein and no correlation with serum creatinine, the rate of glomerular sclerosis.