Alteration of glomerular anionic sites and expression of renal heparanase in respiratory syncytial virus nephropathy in rats / 中华实用儿科临床杂志

Objective To observe the alteration of glomerular anionic sites and renal heparanase (Hpa)expression in respiratory syncytial virus(RSV) nephropathy in rats,and to investigate the role of Hpa in the pathogenesis of proteinuria in RSV nephropathy.Methods Twenty-five Sprague-Dawley (SD) rats were inoculated with 6 x 106plaque forming units(PFU) RSV and were sacrificed on days 4,8,14 and 28 post-inoculation(RSV4,RSV8,RSV14 and RSV28 group).Five normal SD rats served as normal control.The proteinuria and serum parameters were measured.Glomerular anionic sites were measured by histochemical electron microscopy.The expression of Hpa in kidney was determined by immunohistochemical staining.The relationship between the expression level of Hpa and the quantity of 24-hour urine protein was studied.Results After inoculation,the proteinuria increased,especially in RSV14 group.The 24-hour urine protein of RSV14 group,RSV8 group,RSV28 group,RSV4 group and normal group were (30.9860 ± 3.3464)mg,(15.3212 ± 1.2249) mg,(13.9193-2.1409) mg,(11.5857± 1.5705) mg,(3.9780 ± 0.6224) rag,respectively.The serum albumin of RSV14 group decreased.The anionic sites of glomerular basement membrane(GBM) decreased in RSV nephropathy.The number of anionic sites per 1000 nm GBM of RSV14 group,RSV8 group,RSV28 group,RSV4 group and normal control group were 12.0000 ± 1.5811,14.0000 ± 1.0000,14.6000 ± 1.1401,16.8000 ± 0.8366 and 21.2000 ± 1.3038,respectively.Hpa in glomeruli couldn't be detected in normal rats.Glomerular Hpa expression was up-regulated in RSV nephropathy.The expression of glomerular Hpa of RSV14 group,RSV8 group,RSV28 group and RSV4 group were 0.6622 ±0.1145,0.5511 ± 0.0257,0.3524 ± 0.0296 and 0.4521 ± 0.0087,respectively.The expression level of Hpa in RSV8 group and RSV14 group was higher than that in RSV4 group and RSV28 group.There was a linear positive correlation between the expression level of glomerular Hpa and the quantity of 24-hour urine protein (r =0.783,P ＜ 0.05).Conclusions The increased expression of glomerular Hpa in RSV nephropathy of rats leads to loss of the glomerular anionic sites and damage of the electrostatic barrier of GBM,which promote the proteinuria.

Effects of Qufengtongluo Recipe on anionic site in glomerular basement membrane in adriamycin-induced nephropathy rats / 西安交通大学学报(医学版)

Objective To investigate the expression of anionic site in adriamycin-induced nephropathy (AN) rats, and to further explore the effects of Qufengtongluo Recipe on charge barrier in glomerulus in AN rats. Methods Adriamycin nephropathy was induced by a single tail intravenous injection of adriamycin. Totally 80 rats were randomly divided into normal control group and nephropathy model group. Three weeks later, the nephropathy model was established, and 50 AN rats were randomly divided into five groups: nephropathy model group (B, n=10), Qufeng group (C, n=10), prednisone and Qufeng group (D, n=10), prednisone group (E, n=10) and benazepri group (F, n=10), and they were treated respectively. With treatment being given respectively, renal tissue samples in each group were collected at week 3 and 7, respectively. The ultrastructure and expression of anionic site were examined by electron microscope observation. Results ① After adriamycin injection, a significant increase of the 24-hour urinary protein was observed at week 3 (P<0.01). In AN rats, serum albumin was decreased (P<0.01) while serum TCH and TG were increased (P<0.01). ② In AN rats the diffuse fusion and effacement of foot processes and decrease of anionic sites in GBM were observed at week 3. ③ At week 7, the average intensity of AS dramatically increased in C and E groups (P<0.01) compared with that in nephropathy model group. Conclusion The abnormal expression of AS is the important mechanism that leads to the occurrence and development of proteinuria in AN rats. It is possible that Qufengtongluo Recipe has effects on nephrotic syndrome through altering the charge barrier in GBM in glomerulus.

Ultrastructural Changes in Glomerular Anionic Sites in Puromycin Aminonucleoside Nephropathy

An ultrastructural study was done on puromycin aminonucleoside (PAN) nephropathy which was induced in a group of Sprague-Dawley rats by a single intraperitoneally injected dose. To study the ultrastructural alteration of glomerular anionic sites renal tissue was stained with polyethyleneimine (PEI) as a cationic probe. The PEI method seemed to selectively stain heparan sulfate proteoglycan in the basement membrane and has been widely used to evaluate the changes of the basement membrane in human diseases as well as in experimental work. The experimental rats developed proteinuria three days after the PAN injection. Electron microscopic studies of glomeruli showed the loss of epithelial foot processes, formation of cytoplasmic vacuoles, microvillous formation, and increased numbers of lysosomes in the cytoplasm of podocytes. The anionic sites on the basement membrane with foot process fusion were mostly indistinguishable from those seen in control rats, but focal areas of loss or disarray of anionic sites were noted. The anionic sites were not seen on the basement membrane where the overlying epithelium was detached. The results suggest that proteinuria in PAN nephrosis may be primarily due to a glomerular epithelial lesion, leading to focal disarray of anionic sites or focal defects in the epithelial covering of the basement membrane. The loss of anionic sites in the basement membrane may result partially from the foot process fusion, but mostly from the epithelial detachment.

An Anion Site Change of the Glomerular Basement Membrane on Various Glomerular Diseases

We studied the ultrastructural alteration of glomerular anionic sites in 6 patients with minimal change nephrotic syndrome, 5 patients with membranous glomerulonephritis, 4 patients with focal segmental glomerulosclerosis, and 4 patients with IgA nephropathy by staining with polyethyleneimine (PEI) as a cationic probe. The control study was examined by using a nephrectomy specimen of non-glomerular disease which had no proteinuria. This method seems to selectively stain heparan sulphate in the basement membranes and has been widely used to evaluate changes in basement membrane charge in various human diseases as well as in experimental studies. The anionic sites in the lamina rara interna and lamina densa of normal glomerular basement membrane were always less numerous and less regularly distributed than those in the lamina rara externa. Characteristic common findings in these glomeruli showed a marked decrease of glomerular anionic sites in the regions with immune-complex deposits and normal distribution in the regions with focally those being absorbed and newly forming glomerular basement membrane. They were not detected in the gap of the basement membrane and on the area of the detached overlying epithelium using the PEI method. But the foot process fusion of epithelial cells seems not to influence the loss of anionic sites on the glomerular basement membrane.