heparitin-sulfate and Glomerulosclerosis--Focal-Segmental

We examined whether blood pressure reduction or good glycemic control equally lower albuminuria by preventing glomerular loss of heparan sulfate and progression of glomerulosclerosis in streptozotocin-induced diabetic rats. We used doxazosin, and alpha 1-adrenergic blocker, to lower systemic blood pressure, and good glycemic control was achieved by insulin treatment. Rats were killed after 20 weeks of treatment. Doxazosin significantly lowered systolic pressure in diabetic rats; however, it had no effect in normal rats. Good glycemic control also lowered systolic pressure. In diabetic rats with good glycemic control, doxazosin had an additive effect on blood pressure. Glomerular heparan sulfate synthesis was significantly lower and urinary albumin excretion higher in diabetic than in normal rats. Both doxazosin treatment and good glycemic control normalized these abnormalities in diabetic rats. Insulin normalized plasma glucose and glycosylated HbA1 concentrations in diabetic rats, as did doxazosin. Significant increases in mesangial area and glomeruloscelerosis were observed in diabetic rats. Only good glycemic control normalized these pathological changes in all diabetic rats. Two-way factorial ANOVA showed an interaction between the effects of doxazosin and insulin on systolic pressure and plasma glucose. The data show that after 20 weeks of doxazosin treatment, albuminuria was reduced by 80%; however, this treatment had no significant effect on mesangial expansion or progression to glomerulosclerosis. Conversely, good glycemic control prevented all three of the preceding sequelae.

Topics: Adrenergic alpha-Antagonists; Albuminuria; Animals; Blood Glucose; Blood Pressure; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Doxazosin; Glomerular Mesangium; Glomerulosclerosis, Focal Segmental; Heparitin Sulfate; Incidence; Insulin; Kidney Glomerulus; Male; Proteinuria; Rats; Rats, Wistar; Systole

The saccharide side chains of heparan sulfate (HS) proteoglycans show enormous complexity. These polysaccharides can interact specifically with cytokines such as basic fibroblast growth factor (bFGF). The understanding of HS expression in glomerulosclerosis and interstitial fibrosis, which is still rudimentary, could provide some insight about the role of bFGF in kidney diseases.. Kidney sections were exposed to exogenous bFGF and then to a monoclonal anti-bFGF antibody. Specificity of the interaction between HS and bFGF was established by monitoring concomitant loss of bFGF during selective removal of HS with heparitinase and competitive inhibition studies. To further characterize regional changes in saccharide sequences, heparitinase-generated unsaturated disaccharides, N-sulfated glucosamine-enriched but O-sulfate-scarce portions characteristics of native HS, and such portions characteristic of Engelbreth-Holm-Swarm tumor HS were studied.. HS was detected in interstitial fibrosis and in advanced glomerulosclerosis, whereas bFGF-binding domains were found only in the fibrosis: The distributional pattern of the N-sulfate-enriched and O-sulfate-scarce portions of native HS was similar to that of bFGF-binding domains. Moreover, a small population of parenchymal cells in advanced tubulointerstitial fibrosis with marked cellular infiltration were especially rich in the bFGF-binding domains.. In fibrotic lesions of the peritubular interstitium, HS shows enrichment of bFGF-binding domains. These regions may play an important role in the fibrogenesis through their interaction with endogenous bFGF.

Topics: Adult; Female; Fibroblast Growth Factor 2; Glomerulosclerosis, Focal Segmental; Heparitin Sulfate; Humans; Immunohistochemistry; Kidney Glomerulus; Male; Middle Aged; Nephritis, Interstitial

Topics: Animals; Dietary Proteins; Disease Models, Animal; Extracellular Matrix Proteins; Gene Expression Regulation; Glomerulosclerosis, Focal Segmental; Glycoproteins; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Kidney Glomerulus; Metalloendopeptidases; Nephrectomy; Proteinuria; Proteoglycans; Puromycin; Rats; RNA, Messenger; Tissue Inhibitor of Metalloproteinases

Topics: Antibodies, Monoclonal; Binding Sites; Fibroblast Growth Factor 2; Fibrosis; Glomerulosclerosis, Focal Segmental; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Humans; Immunoenzyme Techniques; Kidney; Proteoglycans

Most glomerular pathologies are associated with alterations of the matrix compartment. Using reagents directed against the alpha 1/alpha 2 and alpha 3 chains of type IV collagen [alpha 1/alpha 2(IV), alpha 3(IV)], laminin, heparan sulphate proteoglycan (HPG), fibronectin, collagen I, and collagen III, we investigated the modifications of the glomerular matrix components in several human glomerular lesions compared with normal kidney. In type I membranous glomerulonephritis (MGN) (nine cases), we did not observe alterations in the matrix component distribution. In MGN types II and III (five cases), the spikes and chainettes were made of the alpha 3(IV) chain, laminin, and HPG, while the alpha 1/alpha 2(IV) chains were localized along the subendothelial side of the glomerular basement membrane (GBM). In focal and segmental glomerulosclerosis (six cases), fibronectin, alpha 1/alpha 2(IV) chains, laminin, and small amounts of interstitial collagens were detected within the collapsed capillary loops; the newly formed matrix material between the podocytes and the GBM contained the alpha 1/alpha 2(IV) chains, laminin, and HPG but not the alpha 3(IV) chain. In crescentic glomerulonephritis (six cases), fibronectin was the most abundant and, in purely cellular crescents, the unique component. A basement membrane-like network containing laminin, HPG, alpha 1/alpha 2(IV) chains, and interstitial collagens developed in a second step between the crescent cells. Interstitial collagens were present in the crescent framework, even when the integrity of Bowman's capsule was preserved.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Collagen; Extracellular Matrix Proteins; Fibronectins; Glomerulonephritis; Glomerulonephritis, Membranoproliferative; Glomerulonephritis, Membranous; Glomerulosclerosis, Focal Segmental; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Humans; Immunoenzyme Techniques; Kidney Glomerulus; Laminin; Proteoglycans

This study was designed to assess how the expression of genes for components of the extracellular matrix is altered in a model of focal glomerular sclerosis. In this model, a unilateral nephrectomy combined with injections of puromycin aminonucleoside induces a much higher incidence of focal glomerular sclerosis. Rats received puromycin aminonucleoside on days 0, 27, 34, and 41 and underwent unilateral nephrectomy on day 22. Control rats received physiologic saline injections with and without unilateral nephrectomy. Rats from each group were killed on days 48, 60, and 80. The steady-state levels of glomerular mRNA encoding type IV collagen, the B1 and B2 chains of laminin, heparan sulfate proteoglycan, and type I and type III collagens were compared in both the puromycin aminonucleoside-treated and the control glomeruli. The mRNA levels encoding type IV collagen and laminin B1 and B2 were increased three-, two-, and twofold, respectively, on day 48 of focal glomerular sclerosis. These transcripts were further increased eight-, seven-, and eightfold, respectively, on day 80 compared with the control glomeruli (P < 0.01). In contrast, heparan sulfate proteoglycan mRNA levels were not increased on day 48 when the animals had marked proteinuria. However, the heparan sulfate proteoglycan mRNA levels did become elevated by day 60 and remained elevated thereafter. The expression of type I and type III collagen mRNA was increased 12- and 7-fold, respectively (P < 0.01), on day 80 in focal glomerular sclerosis rats compared with the controls. An immunofluorescence study revealed the accumulation of immunoglobulin M, C3, type IV collagen, laminin, heparan sulfate proteoglycan, and type I and type III collagens in the sclerotic area. These data indicate that changes in the mRNA levels for components of the basement membrane and interstitial collagen are associated with the development of glomerular sclerosis.

Topics: Animals; Collagen; Disease Models, Animal; Extracellular Matrix; Extracellular Matrix Proteins; Gene Expression; Glomerulosclerosis, Focal Segmental; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Kidney Glomerulus; Laminin; Male; Nephrectomy; Proteoglycans; Puromycin Aminonucleoside; Rats; Rats, Sprague-Dawley; RNA, Messenger

Expansion of the mesangial extracellular matrix (ECM) with subsequent glomerular sclerosis is a prominent finding in most progressive renal diseases. To investigate the chronology of accumulation of ECM components as it relates to previously described cellular events, biopsies were obtained from rats at various times following 5/6-nephrectomy as well as from sham-operated controls. The biopsies were stained with PAS as well as immunostained for PCNA (a cell proliferation marker), monocytes/macrophages, types I and IV collagen, laminin, s-laminin, fibronectin, heparan sulfate proteoglycan and entactin/nidogen. Immunostaining of biopsies obtained from 5/6 nephrectomized rats demonstrated an early glomerular cell proliferation, peaking at week 2. Expansion of the glomerular tuft area with rare glomeruli demonstrating focal sclerosis were also seen at week 2. Glomerular macrophage influx correlated with later ECM expansion and glomerulosclerosis. A progressive accumulation of all ECM proteins investigated was noted in the pathological mesangial matrix at week 2 and later time points. Northern analysis of total glomerular RNA at weeks 2 and 6 after 5/6 nephrectomy showed de novo expression type I collagen mRNA as well as small increases of glomerular mRNA levels for type IV collagen (1.2- and 1.4-fold over control RNA) and laminin (1.3- and 1.5-fold) but not s-laminin (1.1- and 0.9-fold). We conclude that cellular events including glomerular cell proliferation and macrophage influx are associated with increased gene and protein expression by ECM proteins in the remnant kidney model and may contribute to the development of sclerosis.

Topics: Animals; Cell Division; Collagen; Disease Models, Animal; Extracellular Matrix Proteins; Fibronectins; Glomerulosclerosis, Focal Segmental; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Histocytochemistry; Immunohistochemistry; Kidney Failure, Chronic; Kidney Glomerulus; Laminin; Male; Membrane Glycoproteins; Nephrectomy; Proteoglycans; Rats; RNA, Messenger

To evaluate the specificity of a raised heparan sulphate (HS) excretion previously reported in four children with congenital nephrotic syndrome (CNS), we measured the urinary excretion of HS and chondroitin sulphate (CS) in seven children with Finnish-type congenital nephrotic syndrome (CNSF), seven with diffuse mesangial sclerosis (DMS), nine with focal segmental glomerulosclerosis (FSGS), 14 with steroid-sensitive nephrotic syndrome of whom eight had a biopsy confirming minimal change histology (SSNS), and 17 controls. The urine HS/CS ratio in normal children had a median of 0.36 (observed range 0.21 to 0.68) and was independent of age. HS/CS ratio was significantly greater than controls in CNSF (median 0.80, range 0.43 to 1.28), DMS (median 0.81, range 0.49 to 1.13) and FSGS children (median 0.66, range 0.38 to 1.6), but was not in SSNS (median 0.44, range 0.28 to 0.70). There was a positive correlation between the HS/CS ratio and urine albumin excretion. High HS/CS ratios are not diagnostic of a particular histological variety of CNS.

Topics: Albuminuria; Child; Child, Preschool; Chondroitin Sulfates; Creatinine; Female; Glomerulosclerosis, Focal Segmental; Glycosaminoglycans; Heparitin Sulfate; Humans; Infant; Male; Nephrosis, Lipoid; Nephrotic Syndrome; Steroids

Mice transgenic for growth hormone (GH) develop progressive glomerulosclerosis. The compositions of kidney extracellular matrix (ECM) and ECM mRNA were examined. The glomerulosclerotic areas in GH mice contained types I and IV collagen, laminin, and basement membrane heparan sulfate proteoglycan (HSPG), which increased with age. The type IV collagen, laminin B2, and HSPG mRNA levels in GH mice, measured by a solution hybridization RNase protection assay, were increased over normal littermates. These findings suggest that the accumulation of ECM components in the glomeruli of GH mice is regulated at the transcriptional level and that glomerulosclerosis is, in part, due to the excess production of ECM rather than simply a reduction in its turnover. The glomerular lesions in GH mice resemble diabetic nephropathy and may allow further dissection of the molecular basis of certain forms of glomerulosclerosis.

Topics: Aging; Animals; Collagen; Extracellular Matrix; Fluorescent Antibody Technique; Glomerular Mesangium; Glomerulosclerosis, Focal Segmental; Growth Hormone; Heparitin Sulfate; Immunohistochemistry; Laminin; Mice; Mice, Transgenic; RNA, Messenger

This study deals with the quantification of mRNA of basement membrane components (laminin, type IV collagen, heparan sulfate proteoglycan) and type I collagen in focal glomerular sclerosis induced by the aminonucleoside of puromycin (PAN) in rats. PAN (15 mg/100 g B.W.) was injected intraperitoneally to male Sprague-Dawley rats on day 0. On day 22, the right kidney was removed from group II and III. Rats in group III received injections of PAN (5 mg/100 g B.W.) on day 27, 34 and 41. Rats in group II received injections of 0.9% NaCl instead of PAN. Remnant kidneys were removed on days 48, 60 and 80 and processed for RNA isolation and histopathological study. Glomerular RNAs were isolated using guanidinium thiocyanate and then dotted onto nylon membrane. Filters were hybridized with specific cDNA probes and exposed to film for analysis by densitometer. FGS was detected in 70% of glomeruli on day 80 in group II. All the basement membrane components and type I collagen were accumulated in the sclerotic areas. The mRNA coding for laminin and type IV collagen continued to increase in group III till day 80. The mRNA for HSPG decreased when the urinary protein excretion was maximum on day 48, then increased with the remission of proteinuria. The type I collagen mRNA also increased during the course of the FGS. We suggest that decrease of mRNA for HSPG may play an important role in the development of proteinuria in PAN nephrosis and increase of mRNA coding for laminin, type IV collagen and type I collagen may be involved in focal glomerular sclerosis.

Topics: Animals; Basement Membrane; Chondroitin Sulfate Proteoglycans; Collagen; Disease Models, Animal; Gene Expression; Glomerulosclerosis, Focal Segmental; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Laminin; Male; Puromycin; Rats; Rats, Inbred Strains; RNA, Messenger