Kidney Basement Membranes Research Articles

Increased concentration of albumin in kidney basement membranes in diabetes mellitus.

The concentration of albumin was measured by a double-antibody radioimmunoassay in the glomerular basement membrane (GBM) and tubular basement membrane (TBM) of patients with diabetic nephropathy, other kidney diseases, and normal kidneys. The TBM from diabetics contained significantly more albumin (m +/ SD; 2.75 +/- 0.34 microgram/mg) than the TBM from other diseases (1.00 +/- 0.24 microgram/mg) or normals (1.21 +/- 0.26 microgram/mg) (P less than 0.0001). Similarly, diabetic GBM contained more albumin (2.25 +/- 0.59 microgram/mg) than other diseases (1.22 +/- 0.55) or normals (1.31 +/- 0.36 microgram/mg) (P less than 0.01-0.001). No differences were observed between the normal and other disease groups. Although there were no differences in hydroxyproline content, there was a highly significant correlation between the concentration of hydroxyproline and albumin in the diabetic TBM (r = 0.82), diabetic GBM (r = 0.70), and normal TBM (r = 0.79). Elution studies with different buffers on frozen sections of diabetic kidneys suggest that the albumin is relatively firmly bound. Although albumin is present in extracellular membranes of normal and diseased human kidneys, the concentration is higher in diabetes mellitus.

Increased concentration of albumin in kidney basement membranes in diabetes mellitus

Increased concentration of albumin in kidney basement membranes in diabetes mellitus

Formation of basement membranes in the embryonic kidney: an immunohistological study.

Specific antibodies to laminin, type IV collagen, basement-membrane proteoglycan, and fibronectin have been used in immunofluorescence microscopy to study the development of basement membranes of the embryonic kidney. Kidney tubules are known to form from the nephrogenic mesenchyme as a result of an inductive tissue interaction. This involves a change in the composition of the extracellular matrix. The undifferentiated mesenchyme expresses in the composition of the extracellular matrix. The undifferentiated mesenchyme expresses fibronectin but no detectable laminin, type IV collagen, or basement-membrane proteoglycan. During the inductive interaction, basement-membrane specific components (laminin, type IV collagen, basement membrane proteoglycan) become detectable in the induced area, whereas fibronectin is lost. While the differentiation to epithelial cells of the kidney requires an inductive interaction, the development of the vasculature seems to involve an ingrowth of cells which throughout development deposits basement-membrane specific components, as well as fibronectin. These cells form the endothelium and possibly also the mesangium of the glomerulus, and contribute to the formation of the glomerular basement membrane. An analysis of differentiation of the kidney mesenchyme in vitro in the absence of circulation supports these conclusions. Because a continuity with vasculature is required for glomerular endothelial cell differentiation, it is possible that these cells are derived from outside vasculature.

Concurrent Membranous Glomerulopathy and Diabetes Mellitus-Reply

—J. Charles Jennette, MD, describes a 25-year-old man with membranous nephropathy in whom dependence on isophane insulin suspension for diabetes mellitus developed after receiving high-dosage steroid therapy for an indefinite period. The linking of these two disorders with a common cause, though an intriguing thought, currently lacks substantiation. Bernes et al, 1 in 1962, observed positive immunofluorescence in diabetic kidneys using antiserum to beef insulin and suggested that the renal damage in diabetic patients might be caused by immune complex deposition, with insulin being the exogenous antigen. However, subsequent immunohistological studies by Westberg et al 2 and Thompsen 3 failed to confirm the immunologic cause of diabetic glomerulosclerosis. They concluded that the linear deposition of immunoglobulins along the glomerular and tubular basement membranes of diabetic kidneys is caused by nonspecific trapping of a variety of plasma proteins, including albumin and ceruloplasmin. Thus, the consensus of opinion at the moment is

Immune complexes in tissues of obese strain (OS) chickens.

Obese strain (OS) chickens develop spontaneous autoimmune thyroiditis (SAT) comparable in many aspects to human Hashimoto's thyroiditis. In a chronologic study on chickens of the Obese strain with B1B1 and B4B4 genotypes, immune and electron dense deposits suggesting immune complexes (IC) were found in the basal lamina of thyroid follicles (BLTF) as early as the time of hatching. The incidence of IC deposition in BLTF increased with age. In some of the chickens studied, thyroglobulin could also be demonstrated in the immune deposits. In addition, IC were also detected in the glomerular basement membrane of kidneys and in basement membranes of cecal tonsils. The early occurrence of IC in tissues of OS chickens suggests a possible primary role of these immune reactants in the pathogenesis of SAT.

1529 MINIMAL CHANGE NEPHROTIC SYNDROME (MCNS): AN AUTOIMMUNE DISEASE?

The presence of low-level tissue directed antibodies (AAb's) and immune complexes (IC) were determined in 12 MCNS and 5 mesangial proliferative glomerulonephritis (MesPGN) patients with biopsy proven disease. The AAb's were detected by immunofluor-escence (IF) against human cadaveric tissues and the IC detected by 3 different methods and isolated by polyethylene glycol precipitation/sedimentation. The isolated antibodies from the IC were also tested by IF for AAb activity against the same tissue antigen battery. The presence of such AAb activity was demonstrated in 8/12 MCNS and in all of the MesPGN sera. In the MCNS group 7/8 of the AAb positive sera also contained IC with corresponding AAb activity (2/7 directed against smooth muscle antigens and 5/7 directed against kidney tubular microsomes). The MesPGN group all reacted against kidney basement membrane antigens but no other tissue antigen. Of these 3/5 also demonstrated the presence of IC which contained AAb reactive with the same kidney antigen. The presence of such AAb's and their formation of IC indicates that these antibodies may have a functional role in the initial immunological insult to the kidney.

Effect of hemodynamic factors in renal glomerulus. I. Alterations of glomerular basement membrane in the experimental congestive kidney.

Renal glomerular function cannot be attributed solely to structural elements in the glomerular capillary wall. Such structural elements certainly contribute to barrier function during ultrafiltration, but normal hemodynamic conditions are also required for optimal ultrafiltration. In order to change the normal hemodynamic state of glomerular capillary, an experimental congestive kidney was made by clipping unilateral renal vein in rabbits.The glomerular basement membrane was observed morphologically and cytochemically (performic acid-phosphotungstic acid reaction, PFP reaction) at various time intervals.The glomerular basement membrane in the congestive kidney showed a localized or widespread thickening and polypoid changes. Cytochemical findings were similar to that of controls.

AMYLOID P-COMPONENT IN HUMAN GLOMERULAR BASEMENT MEMBRANE: Abnormal Patterns of Immunofluorescent Staining in Glomerular Disease

Serum amyloid P-component (SAP) is a normal plasma protein and is a constituent of normal human glomerular basement membrane. Immunofluorescence with anti-SAP antibody produced characteristic linear staining along the glomerular basement membrane in normal kidneys. Distinctive abnormal staining patterns were seen in renal biopsy specimens from patients with diabetes, membranous glomerulonephritis, mesangiocapillary nephritis, systemic vasculitis, Goodpasture's syndrome,

Ultrastructural localization of fibronectin and laminin in the basement membranes of the murine kidney.

Affinity-purified rabbit antibodies specific for two large noncollagenous gycoproteins--laminin and fibronectin--were used to study the distribution of these proteins in normal murine kidneys. Immunofluorescence staining of conventional frozen sections demonstrates fibronectin within mesangial areas of the glomerulus. Laminin is also found in mesangial areas. However, it also appears to be distributed in typical basement membranelike patterns on glomerular and tubular basement membranes and Bowman's capsule. At the ultrastructural level, by labeling 600-800-A thick frozen sections with a three-stage procedure consisting of specific antibodies, biotinyl sheep anti-rabbit IgG, and avidin-ferritin conjugates, fibronectin is present ony in the mesangial matrix and is specifically localized to areas immediately surrounding mesangial cell processes. Laminin, on the other hand, is found uniformly distributed throughout tubular basement membranes, the mesangial matrix, and Bowman's capsule. In glomerular basement membranes, laminin labeling is restricted to the lamina rara interna and adjacent regions of the lamina densa.

Isolation of a heparan sulfate-containing proteoglycan from basement membrane.

We have isolated a unique, basement membrane proteoglycan from the Engelbreth-Holm-Swarm (EHS) sarcoma. This proteoglycan, estimated to be 0.75 X 10(6) daltons, was found to contain about equal amounts of protein and covalently linked heparan sulfate. Antibody prepared against this proteoglycan reacts with the basement membrane matrix in the tumor and with the basement membranes in skin, kidney, and cornea. These studies indicate that the heparan sulfate proteoglycan is a normal constituent of basement membranes that presumably plays an important role in the organization of basement membrane components and that also may determine the permeability of basement membranes to acidic molecules.

The role of glycoprotein carbohydrate in the immunological reactivity of antistreptococcal cell-membrane and antiglomerular basement-membrane antisera.

Rabbit antisera to "carbohydrate-rich" antigens prepared from group-A, type-12 streptococcal cell-membrane and human glomerular basement-membrane were found to react by an indirect fluorescent-antibody test with the glomerular basement membrane of adult human kidney. This activity was absent or diminished in neonatal tissue. Removal of the carbohydrate epitopes from the adult tissue by means of carbohydrases removed the immunological activity. Antisera against the "carbohydrate-rich" antigens showed immunological reactivities distinctly different from those against the parent native immunogens--streptococcal cell membrane or glomerular basement membrane--which proved to be directed towards the portein epitopes.

Association of thy-1 cell surface differentiation antigen with certain connective tissues in vivo.

The cell surface differentiation antigen, Thy-1, has been demonstrated by immunofluorescence to be associated with some collagen-based connective tissue. In the rat, the basement membrane of kidney collecting tubules of certain blood vessels, reticulin of the lamina propria, loose connective tissue in the dermis, and collagen fibres within certain nerve cell tumours, bear the antigen. Other, apparently similar, connective tissue (especially that of muscle and liver) lacked Thy-1. In the mouse, only the connective tissue of the skin was found to bear the antigen. The possible origin of this extracellular Thy-1, and its implications for the function of the molecule, are discussed.

Mucopolysaccharide heterogeneity of the reptilian kidney basement membranes

The kidney basement membranes of fifteen different reptiles from marine, terrestrial, desert, amphibious and fresh-water habitats have been analysed for their mucopolysaccharide contents histochemically, employing well-known and recent techniques. Capsular and tubular basement membranes possess only neutral mucopolysaccharides; on the other hand glomerular basement membrane possesses both neutral and acidic (sialic acid) mucopolysaccharides. The concentration of different mucopolysaccharides seems to be dependent on the type of habitat. Their possible physiological significance in the kidney function is discussed in great details.

Synthesis of the glomerular basement membrane in the rat kidney. Autoradiographic studies with the light and electron microscope.

To study the origin and the formation of the glomerular basement membrane, autoradiographic investigations with 3H-proline and 3H-leucine have been performed in ultrathin with semithin sections of the glomeruli of 42 male rats. The results of this study indicate that, of the three cell types of the glomerulus, the epithelial cells (=podocytes) synthesize the proline-rich scleroproteins of the glomerular basement membrane. Our autoradiographic studies have yielded no evidence for participation of the endothelial or mesangial cells in the formation of the basement membrane. The mesangial cells appear to be responsible for the synthesis of the mesangial matrix only.

Electron dense alteration of kidney basement membranes. A renal lesion specific of a systemic disease : Galle P, Mahieu P: Am J Med 58: 749–764, 1975

Electron dense alteration of kidney basement membranes. A renal lesion specific of a systemic disease : Galle P, Mahieu P: Am J Med 58: 749–764, 1975

Electron dense alteration of kidney basement membranes: A renal lesion specific of a systemic disease

Described here are the findings of a clinical, anatomic and chemical study of 40 patients having an original lesion of the basement membranes of the kidney. This lesion is characterized by an ultrastructural modification of the basement membrane substance which appears very dark (black) and homogeneous in electron micrographs. It affects the basement membranes of the glomerulus, Bowman's capsule and the renal tubules. Patients with this lesion all manifest the clinical course of a chronic nephritis and is almost invariably accompanied by proteinuria and microscopic hematuria. The disease evolves generally with intermittent episodes towards irreversible renal failure. Eight patients received kidney transplants. Study of these transplants has shown that the lesion recurs in the transplanted kidneys during the year following transplantation. Moreover, it is never found in kidneys transplanted into patients who did not have it in their own kidneys. This ultrastructural lesion can therefore be placed in the framework of a systemic disease whose etiology is not yet known. The study of these transplants also shows that the lesion can exist despite the absence of any detectable clinical or biologic signs and be well tolerated for periods which now exceed 4 years for three patients.

Nephropathy associated with sickle cell anemia: An autologous immune complex nephritis: I. Studies on nature of glomerular-bound antibody and antigen identification in a patient with sickle cell disease and immune deposit glomerulonephritis

The nature of the glomerular-bound antibody and the putative antigen was investigated in one of the patients with sickle cell disease and immune deposit membranoproliferative glomerulonephritis by immunohistologic and glomerular antibody elution. Renal proximal tubular epithelial antigen was localized in association with immunoglobulins G (IgG), M (IgM), Clq fraction of the first component of complement (Clq) and the third component of complement (C 3) in a granular pattern along the glomerular basement membrane of the patient's kidney. IgG and IgM were eluted from glomeruli. These immunoglobulins fixed to the proximal tubules of normal human kidney by direct immunofluorescence. This localization was abolished by absorption of the eluted immunoglobulins with renal tubular epithelial (RTE) antigen. The IgG eluted from the glomeruli blocked the fixation of rabbit anti-RTE antigen to normal proximal tubular brush border. These studies suggest that the nephritis in this patient was due to deposition of complexes of RTE antigen and specific antibody. An autologous immune complex nephritis may develop in some patients with sickle cell anemia secondary to RTE antigen released possibly after renal ischemia or some other phenomenon causing renal tubular damage.

Chemical compositions of glomerular and tubular basement membranes of human kidney.

Glomerular basement membranes (GBM) and tubular basement membranes (TBM) were prepared from human kidney and their chemical compositions were studied. Electron microscopic figures showed no contamination of the cellular components components or collagen fibers, indicating a high degree of purity of the preparations. Low contents of phospholipid supported this indication. Amino acid compositions of the human GBM and TBM resembled that of the bovine GBM, containing hydroxyproline, hydroxylsine, half-cystine, methionine and a large amount of glycine as the characteristic amino acids. The human GBM and TBM had similar carbohydrate compositions consisting of glucose and galactose, as the major sugars, together with mannose, L-fucose, hexosamine and sialic acid. Glucosylgalactosylhydroxylysine and a small amount of galactosylhydroxylysine were detected in alkaline hydrolyzates of both membranes. The human GBM and TBM separated into more than ten subunits having molecular weights ranging from 2.5 times 10-4 to more than 2.5 times 10-5 on polyacrylamide gel electrophoresis in the presence of sodium laurylsulfate and 2-mercaptoethanol. The electrophoretograms of both membranes resembled that of the bovine GBM. These observations indicate that the human TBM has a similar chemical structure to those of the human GBM and the bovine GBM.

Epithelial Basement Membrane of Bovine Renal Tubuli. Isolation and Analysis of the Carbohydrate Chains

The carbohydrate chains present in the tubular basement membrane of bovine kidney were studied. Digestion with collagenase followed with pronase resulted in a complete solubilization of the basement membrane. The different glycopeptides were purified by gel filtration and ion-exchange chromatography. Two kinds of carbohydrate chains could be characterized: oligosaccharides composed of glucosamine, mannose, galactose, fucose and sialic acid, and glucosylgalactose disaccharides. A very small portion of the oligosaccharide chains (ca. 4%) appeared to be free of sialic acid. The bulk of these chains contained sialic acid and fucose, although in small amounts. Only traces of galactosamine were found.

Immunological studies of the human placenta. Characterization of immunoglobulins on trophoblastic basement membranes.

Immunohistological and elution studies of the human placenta revealed the presence of IgG on the trophoblastic basement membrane (TBM) which demonstrated specificity for placental but not lung, thyroid, or kidney basement membranes, suggesting the presence of a placenta-specific antigen in TBM. IgG comprised the bulk of immunoglobulin in eluates, and small amounts of IgA, trace amounts of IgM, but no IgE or IgD were identified in eluates. The distribution of IgG subclasses in eluate was not unusual as compared to maternal and neonatal sera, and Gm and Inv typing of eluates indicated that it was of maternal origin. Small amounts of eluate-IgG effectively inhibited the blastogenic response of unrelated lymphocytes to old tuberculin, phytohemagglutinin, and in one- or two-way mixed lymphocyte culture reactions. The inhibition was distinct from nonspecific inhibitors, and dose-response analysis indicated that eluate was very much more potent as an inhibitor than were the nonspecific inhibitors. Inhibition was shown to not be due to anti-HL-A activity, and was probably not due to aggregated IgG or immune complexes. Binding of eluate to lymphocytes was very loose as shown by washing experiments, and no binding could be shown by immunofluorescence. The capacity of eluate IgG to inhibit MLC was retained after pepsin digestion to F(ab')(2), suggesting that the inhibition reactions were immunological. It is suggested that eluate-IgG is maternal blocking antibody to a hitherto uncharacterized trophoblast antigen, and it is speculated that either abnormal antigen or aberrant responses to antigen could result in fetal wastage.