Biomedical subjects

R J Butkowski

Publications and source records attributed to R J Butkowski.

At least 19 recordsLinked to original sources

PubMed1995

Identification of a cDNA encoding tubulointerstitial nephritis antigen.

Tubulointerstitial nephritis antigen (TIN-ag) is a 58-kDa basement membrane glycoprotein that is recognized by human autoantibodies in certain forms of tubulointerstitial nephritis. To further characterize this macromolecule and isolate cDNAs encoding TIN-ag, amino acid sequences from tryptic peptides were used to design and synthesize primers in order to amplify a probe for screening a rabbit kidney cortex cDNA library. A cDNA encoding TIN-ag was cloned and sequenced. The predicted amino acid sequence deduced from this cDNA includes the chemically determined sequences of peptides derived from TIN-ag, supporting its authenticity. The predicted amino acid sequence also shows that the carboxyl-terminal region of the molecule exhibits a 30% homology with human preprocathepsin B, a member of the cysteine proteinase family of proteins. A domain in the amino-terminal region of TIN-ag contains an epidermal growth factor-like motif that shares homology with laminin A and S chains, alpha 1 chain of type I collagen, von Willebrand's factor, and mucin, suggesting structural and perhaps functional similarities among these molecules. Immunoprecipitation of in vitro generated recombinant protein using a TIN-ag-specific monoclonal antibody (A8), confirms the identity of the isolated TIN-ag cDNA. In this report the cDNA and predicted amino acid sequences of TIN-ag are presented. Knowledge of the primary structure of TIN-ag will facilitate our understanding of the molecular structure of this novel basement membrane component and may provide clues toward understanding its functional role.

Amino Acid Sequence↗

PubMed1995

Human corneal basement membrane heterogeneity: topographical differences in the expression of type IV collagen and laminin isoforms.

BACKGROUND: The corneal epithelium converges at the peripheral zone (limbus) with the conjunctival epithelium, forming a continuous sheet with phenotypically distinct regions--central, limbal, and conjunctival. The epithelial basement membrane (EBM) is important for corneal functions and cell adhesion, but its regional composition is poorly understood. Current literature is controversial as to the occurrence of type IV collagen in the cornea. The aim of this study was to investigate in detail corneal basement membrane (BM) composition and correlate it with the differentiation state of contributing cells. EXPERIMENTAL DESIGN: Adult human corneas (N = 8) were cryosectioned and analyzed by immunofluorescence with antibodies to 15 BM components and to keratin 3, a marker of corneal epithelial differentiation. RESULTS: A novel type of spatial heterogeneity ("horizontal") in the EBM composition was found between the central cornea, limbus, and conjunctiva. Central EBM had type IV collagen alpha 3-alpha 5 chains, whereas limbal and conjunctival EBM contained alpha 1-alpha 2 chains and also laminin alpha 2 and beta 2 chains. Limbal EBM in addition had alpha 5(IV) chain. Laminin-1 (alpha 1 beta 1 gamma 1), laminin-5 (alpha 3 beta 3 gamma 2), perlecan, fibronectin, entactin/nidogen, and type VII collagen were seen in the entire EBM. Another novel type of BM heterogeneity ("vertical") was typical for the corneal Descemet's membrane: its stromal face had alpha 1(IV) and alpha 2(IV) chains and fibronectin, whereas alpha 3(IV)-alpha 5(IV) chains, entactin/nidogen, laminin-1, and perlecan were present on the endothelial face. CONCLUSIONS: Type IV collagen controversy is the result of the shifts of isoforms in the limbus and conjunctiva. These shifts and the appearance of additional laminins in the limbus may be related to the differentiation state of corneal cells contributing to the EBM formation. Novel types of BM heterogeneity in the human cornea are described: regional (horizontal) in the EBM and vertical in the Descemet's membrane. The first one may be a common feature of converging complex epithelia, whereas the second one may be another unique property of the Descemet's membrane.

Adult↗

PubMed1994

Tubular basement membrane changes during induction and regression of drug-induced polycystic kidney disease.

Defective cell-extracellular matrix (ECM) biophysiology is considered a factor in the development of polycystic kidney disease (PKD). Altered biosynthesis of various ECM components may result in tubular dysmorphogenesis and uncontrolled tubular cystic expansion. In this study, expression of certain ECM components was investigated in a diphenylthiazole (DPT)-induced rat model of PKD. DPT induces cystic change in all the collecting tubules, most severe in the outer medulla and inner cortex, and following withdrawal of DPT, cystic tubules return to normal with persistence of focal interstitial fibrosis. SDS-PAGE analyses of isolated tubular basement membranes (TBMs) of control and PKD kidneys revealed overall similar electrophoretic migratory bands. However, in PKD, there were relative increases in components with M(r) approximately 380,000, 250,000 and 145,000, and a decrease in the component with M(r) approximately 55,000. Immunoblot analyses revealed that the major components of TBM (type-IV collagen, laminin beta 1 and beta 2 chains and entactin) were present in the same relative concentrations in control and PKD. The expression of tubulointerstitial (TIN) antigen was decreased. Also, the relative concentrations of type-I collagen and fibronectin were increased in the PKD group. Following recovery, the expressions of TIN and fibronectin returned to normal, whereas type-I collagen remained elevated. ELISA determinations revealed increased expression of interstitial collagens type-I, -V and -VI in PKD vs control and they remained elevated following recovery, while that of type-III was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

The Goodpasture antigen: common epitopes in the globular domains of collagen IV.

To determine the nature of Goodpasture antibody-reactive epitopes on the globular domains of collagen IV [non collagenous (NC) domain], Goodpasture antigen was characterized by immunochemical and immunohistological techniques using affinity-purified (AP) Goodpasture autoantibodies. Affinity purification of Goodpasture autoantibodies toward alpha 1(IV), alpha 2(IV), and alpha 3(IV) NC domains was performed and revealed antigenic cross-reactivity with all alpha(IV) NC domain subunits, which was confirmed by inhibition ELISA. Since by immunofluorescent microscopy all 3 AP Goodpasture antibodies only stained the central portion (lamina densa) of bovine glomerular basement membrane, it appears that there are common epitopes reactive with Goodpasture autoantibodies present on alpha 1(IV) NC, alpha 2(IV) NC, and alpha 3(IV) NC domains.

Animals↗

PubMed1992

Role of antibodies to tubulointerstitial nephritis antigen in human anti-tubular basement membrane nephritis associated with membranous nephropathy.

We report three patients, from two unrelated families, with anti-tubular basement membrane (TBM) antibody nephritis associated with membranous nephropathy. This rare disorder is characterized by nephrotic syndrome, tubular dysfunction, and progression to renal failure. Direct immunofluorescent studies in these patients revealed linear IgG deposition along the proximal TBM, while circulating antibodies reacting with proximal TBM but not with glomerular basement membrane were identified by indirect immunofluorescence. Sera from all three patients reacted by enzyme-linked immunosorbent assay and Western immunoblotting with purified 58-kd tubulointerstitial nephritis (TIN) antigen isolated from TBM. Additional reactivity with a 175-kd component, which may be a higher-molecular-weight form of TIN antigen, was observed by immunoblotting. Since recurrent Fanconi syndrome was seen after transplantation in one patient, anti-TBM antibodies were removed by plasmapheresis prior to kidney transplantation in the other two patients. Neither patient has clinical evidence of recurrent anti-TBM nephritis in the allograft despite the posttransplantation reappearance of anti-TBM antibodies in the serum of one patient. Serologic and molecular HLA class I and class II polymorphism analysis has identified the presence of both HLA-B7 and -DRw8 antigens in two unrelated affected individuals (0.3% expected frequency in the white population). We conclude that sera from patients with anti-TBM nephritis associated with membranous nephropathy react with 58-kd TIN antigen previously implicated in the pathogenesis of primary anti-TBM nephritis. This rare autoimmune disorder may be HLA associated with B7 and/or DRw8, providing susceptibility to the disease. Further investigation is needed to understand the pathogenesis of recurrent anti-TBM nephritis in the renal allograft.

Antibodies, Anti-Idiotypic↗

PubMed1992

Partial protein sequence of the globular domain of alpha 4(IV) collagen chain: sites of sequence variability and homology with alpha 2(IV).

The globular domain (NC) of alpha 4(IV) collagen chain was partially sequenced and compared with the NC domain of other collagen IV chains. The alpha 4(IV) NC domain was found to be most closely related to alpha 2(IV) NC domain but distinct from the NC domain of alpha 1(IV), alpha 2(IV), alpha 3(IV) and alpha 5(IV) collagen chains. Partial sequence, representing nearly one half of alpha 4(IV) NC domain, shows 56%, 69%, 51% and 54% identity with the corresponding NC domains of alpha 1(IV), alpha 2(IV), alpha 3(IV) and alpha 5(IV) collagen chains, respectively. A short, highly polar, region of variable sequence is found near the carboxy terminus of alpha 4(IV) NC domain. This sequence corresponds to a non-conserved region among NC domains, suggesting functional specialization at this site. It exhibits high surface probability with predicted structural differences among NC domains. These results confirm uniqueness of alpha 4(IV) NC domain and indicate its structural relatedness to other NC domains of collagen IV.

Amino Acid Sequence↗

PubMed1991

X-chromosome inactivation in the liver of female heterozygous OTC-deficient sparse-furash mice.

X-chromosome inactivation patterns were investigated in livers of nine spfash female heterozygous ornithine transcarbamylase (OTC)-deficient mice. Quantitative morphometric analysis of cellular mosaicism was performed on sections of frozen liver reacted with purified anti-OTC antibody and prepared for immunofluorescent microscopy. Analysis of enzymatic OTC activity was performed on sections of these livers using a radiochromatographic technique. Several areas of cellular mosaicism were seen in each of the histological sections that were studied. The distribution of the volume fraction of the liver tissue cells having cells with normal OTC content among the nine mice ranged from 20 to 70% and it correlated (r = 0.8, P = 0.005) with the enzymatic activities of the respective livers. The extreme variegation of mosaic patches in the liver suggests the high probability that a single needle biopsy will be diagnostic in females heterozygous for an OTC mutation. This study also suggests that at the time of X inactivation, the number of primordial liver embryonic cells is small and the observed variegation of liver mosaicism probably results from complex migration patterns of liver cells during fetal development. This study shows that the spfash mouse is a suitable animal model for quantitative studies of X-chromosome inactivation in liver using immunohistochemical staining of OTC protein.

Animals↗

PubMed1991

Renal entactin (nidogen): isolation, characterization and tissue distribution.

Entactin/nidogen (E/N) was isolated from bovine renal tubular basement membrane. Apparent molecular weight, amino acid composition, and molecular configuration by electron microscopy rotary shadowing were similar to that of nidogen from EHS mouse tumor. The identity of bovine E/N was confirmed using a thrombin derived peptide, the sequence of which corresponded to a region within mouse and human E/N. Monoclonal and polyclonal anti-E/N antibodies were used to determine the distribution of E/N in human kidney by immunofluorescent and immunoelectron microscopy. E/N was present in all renal basement membranes and was distributed through the full width of the glomerular basement membrane (GBM) with accentuation along its epithelial aspects. E/N distribution was similar to that of novel collagen chain alpha 3(IV) NC domain in the GBM. In the mesangium, E/N was distributed mainly in the peripheral mesangial region that is bounded by the GBM, while classical collagen chain alpha 1(IV) NC as present diffusely throughout the mesangium. In the developing nephron, E/N was present in basement membranes of the ureteric bud, primitive vesicle and S-form. In all instances, E/N co-localized with laminin B2 chain. Prominent E/N detection within the mesangium was observed in diseases where mesangial expansion was present. This process was also seen in early diabetic nephropathy, but disappeared with disease progression. However, all thickened diabetic renal basement membranes showed an increase in E/N which was also present in Kimmelstiel-Wilson lesions. E/N was observed in the GBM "spikes" of membranous glomerulonephritis and in epithelial crescents associated with various disorders. The association between E/N, laminin and type IV collagen chains observed in the normal kidney were maintained in disorders with altered E/N distribution. We could not detect any changes in the distribution of E/N in other acquired and hereditary kidney diseases. These observations reflect the involvement of E/N in the structure and disease alteration of renal basement membranes and mesangial matrix.

Amino Acid Sequence↗

PubMed1991

Distribution of tubulointerstitial nephritis antigen and evidence for multiple forms.

A monoclonal antibody (A8) to a basement membrane component (TIN antigen), which is associated with autoimmune tubulointerstitial nephritis, was developed and utilized to characterize tissue distribution and properties of TIN antigen by immunofluorescence microscopy and immunoblotting. Results were confirmed with polyclonal goat anti-rabbit and human autoantibodies. TIN antigen was found in basement membranes of kidney cortex, small intestines, skin, and cornea, but was not detected in the renal medulla. Within the kidney cortex proximal tubular basement membrane (TBM) showed the strongest staining. TIN antigen was also detected in Bowman's capsule, distal TBM, peritubular capillaries, and focally in the interstitium, but not in glomerular basement membrane or mesangial matrix. Immunoblotting of SDS-extracted human, rabbit, mouse, and Brown Norway rat TBM with A8 revealed predominantly a 58 kD TIN antigen; however, other reactive components were detected in minor quantities. Bovine TBM contained components of 52 kD, 45 kD and 35 kD in varying concentrations. Immunoblotting of isolated rabbit TIN antigen revealed the major 58 kD component that was characterized previously, and minor components of 300 kD, 175 kD, 160 kD and 50 kD. TIN antigen was not detected in Lewis rat TBM by immunofluorescence or immunoblotting. These studies suggest the following: 1) TIN antigen may be synthesized as a high molecular weight glycoprotein that is processed to smaller forms; 2) it may be covalently associated with other basement membrane components; 3) the antibody reactive epitope may be present on multiple TBM components; and 4) high molecular weight forms may represent aggregates of TIN antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Characterization of a tubular basement membrane component reactive with autoantibodies associated with tubulointerstitial nephritis.

A kidney tubular basement membrane (TBM) component that is bound by antibodies from individuals with anti-TBM antibody-associated tubulointerstitial nephritis (TIN) was purified and characterized (TIN antigen). TIN antigen was prepared from rabbit TBM by extraction with guanidine and purified by ion-exchange, gel filtration, and reversed-phase chromatography. Based upon yields of protein and antibody reactivity, TIN antigen accounts for about 9% of the mass of TBM and thus is a major component of this basement membrane. A predominant 58-kDa form comprises about 90% of purified TIN antigen, and a 50-kDa form accounts for the remainder. The two forms share the amino-terminal sequence Ser-Ile-Phe-Gln-Gly-Gln-Tyr-X-Arg-Ser-Phe-Gly- and give similar tryptic peptide maps, indicating that they are structurally related. Their amino acid compositions overall are similar to laminin and entactin/nidogen. The absence of hydroxyproline and hydroxylysine and the low levels of glycine in TIN antigen indicate that it is noncollagenous. No similarities were found between other known proteins and sequences of tryptic peptides and the amino terminus of TIN antigen, suggesting that it is distinct from other characterized basement membrane components. A goat polyclonal antibody toward rabbit TIN antigen showed the same kidney distribution as human antibodies and was completely inhibited in enzyme-linked immunosorbent assay by purified TIN antigen. These data further support the idea that TIN antigen is the primary target for anti-TBM antibodies associated with TIN. This research presents methods to prepare TIN antigen for biochemical studies and investigations of its role in anti-TBM autoimmune TIN.

Amino Acid Sequence↗

PubMed1990

Alport syndrome, basement membranes and collagen.

Alport syndrome, an inherited disorder of the kidney, eye and ear, has fascinated nephrologists, pathologists, and geneticists for nearly a century. With the recent application of molecular biochemical and genetic techniques, this mysterious disease has begun to yield some of its secrets. Alport syndrome can now be viewed as a generalized disorder of basement membranes that appears to result from mutations in an X-chromosome-encoded basement membrane collagen chain. This chain, along with two other novel collagen chains, is absent from Alport basement membranes, in contrast to the classical chains of collagen IV. Phenotypic heterogeneity in Alport syndrome probably arises from allelic mutations at a single genetic locus. The phenomenon of post-transplant anti-glomerular basement membrane nephritis may be a manifestation of specific mutations at the Alport locus that prevent synthesis of the gene's protein product and the establishment of immunological tolerance.

Basement Membrane↗

PubMed1990

A method for preparation of renal tubular basement membrane.

A method is presented for the preparation of tubular basement membrane from renal cortex. The procedure utilizes a Polytron tissue disrupter, differential sieving, and for some species, sucrose density centrifugation. The procedure is especially useful for obtaining highly purified rabbit and bovine tubular basement membranes. Human tubular and glomerular basement membranes can be prepared with some cross contamination. The method offers the capability of rapidly generating large quantities of the basement membranes that retain the Goodpasture antigen and a TBM antigen associated with anti-TBM nephritis.

Animals↗

PubMed1990

Characterization of type IV collagen NC1 monomers and Goodpasture antigen in human renal basement membranes.

Monomeric subunits of the globular domain of type IV collagen from human renal basement membrane were isolated and characterized. The monomers, M24, M26, M28+, and M28 , which have been identified previously in human glomerular basement membrane, were characterized by amino acid analysis, amino-terminal sequencing, and electrophoretic mobility. The results indicate that M24 and M26 are derived from alpha 1(IV) and alpha 2(IV) collagen chains, respectively. Amino-terminal sequencing revealed that M28+, and M28 correspond to the globular domain of novel collagen chains. M28 has been characterized as the principal target antigen in Goodpasture's syndrome and antiglomerular basement membrane (GBM) nephritis, and both M28 species are absent from the GBM in Alport familial nephritis. The cationic charge of M28 appears to be a consequence of a relatively high concentration of basic amino acids when compared with other monomers. Previous studies of bovine GBM have demonstrated chains with amino-terminal sequence homology to M28+ and M28 .

Amino Acid Sequence↗

PubMed1990

Immunochemical analysis of carbamyl phosphate synthetase I and ornithine transcarbamylase deficient livers: elevated N-acetylglutamate level in a liver lacking carbamyl phosphate synthetase protein.

Liver tissue from 3 patients with carbamyl phosphate synthetase I deficiency and 11 patients with ornithine transcarbamylase deficiency was analyzed by Western blots for the presence of carbamyl phosphate synthetase I and ornithine transcarbamylase cross-reactive material with anti-rat enzyme antibodies. One patient with carbamyl phosphate synthetase I deficiency had no cross-reactive material with the antibody to this enzyme, one had reduced amounts, and one had similar to normal amounts. Only one of the patients with ornithine transcarbamylase deficiency had apparently normal amounts of enzyme protein in his liver, another patient had markedly reduced amounts, and the other nine patients had traces or absence of reactive ornithine transcarbamylase protein. N-acetylglutamate content in the carbamyl phosphate synthetase I deficient liver with absent enzyme protein, was higher (98.4 nmol/g) than that measured in 5 normal controls (41.6 +/- 19.3 mean +/- SD, n = 5) and much higher than the N-acetylglutamate level (2.2 nmol/g) in another carbamyl phosphate synthetase I deficient liver with normal amounts of enzyme protein. Hepatic N-acetylglutamate content in 3 patients with complete ornithine transcarbamylase deficiency was below the normal mean but within 2 standard deviations from the mean (8.5-12.8 nmol/g) whereas it was higher (30.7 nmol/g) in another partial ornithine transcarbamylase deficient patient. Most patients with ornithine transcarbamylase deficiency have markedly reduced or undetectable enzyme protein in their liver, therefore. Western blot analysis could help to establish this diagnosis in most patients. Absent carbamyl phosphate synthetase I enzyme protein may have caused elevation of the hepatic content of its cofactor, N-acetylglutamate, by an as yet unknown mechanism.

Adult↗

PubMed1990

Posttransplant anti-glomerular basement membrane nephritis in related males with Alport syndrome.

This report describes the development of anti-glomerular basement membrane (GBM) glomerulonephritis after kidney transplantation in related males with Alport syndrome. Antibodies in sera from one of these patients stained normal GBM, Bowman's capsule, tubular basement membranes, and epidermal basement membranes but did not stain tissues from an unrelated Alport male. The target antigen was found to be a 26 kd peptide of the noncollagenous domain of basement membrane collagen. This study provides further evidence of the importance of abnormalities of basement membrane collagen in the pathogenesis of the Alport nephropathy. We speculate that certain mutations at the Alport locus, such as large intragenic deletions or frame-shift mutations, may be associated with failure to develop immune tolerance to epitopes on this 26kd peptide. In the setting of permissive immune response and regulation, transplantation of a normal kidney may result in the generation of anti-GBM antibodies.

Basement Membrane↗

PubMed1989

Basement membrane collagen in the kidney: regional localization of novel chains related to collagen IV.

Variability in the collagen chain composition of renal basement membranes was demonstrated by immunofluorescent microscopy using polyclonal and monoclonal antibodies and correlating with imaging of the glomerular basement membrane by phase microscopy. Antibodies toward the globular domains of alpha 1(IV) and alpha 2(IV) collagen chains, triple helical and 7S domains of collagen IV bind within the glomerulus to mesangial matrix, along the subendothelial region of the glomerular capillary wall, and to all tubular and vascular basement membranes. The portion of glomerular basement membrane corresponding to the phase dense image is not reactive with these antibodies. A different binding pattern is seen with antibodies against two novel globular regions of basement membrane collagen chains which bind to the phase dense aspect of glomerular basement membrane and to Bowman's capsule. Human tubular basement membrane is not reactive, except along portions of the distal tubule, whereas bovine tubular basement membrane is diffusely reactive; mesangial matrix and extraglomerular vascular basement membranes are not reactive. Although a possible explanation for the regional distribution of basement membrane collagen antigens in the glomerulus may relate to antigen exposure, a more likely reason is that collagen chains are regionally expressed. The staining patterns suggest that the novel collagen chains have a selective tissue distribution compared with alpha 1(IV) and alpha 2(IV) chains and that the glomerular cells of origin of these collagen IV chains may differ.

Animals↗

PubMed1988

Structural heterogeneity of the noncollagenous domain of basement membrane collagen.

The noncollagenous domain of collagen from three different basement membranes of bovine origin (glomerular, lens capsule, and placental) was excised with bacterial collagenase, purified under nondenaturing conditions, and characterized. In each case the domain existed as a hexamer comprised of four distinct subunits (alpha 1 (IV) NC1, alpha 2 (IV) NC1, M2*, and M3). Each subunit exists in both monomeric and dimeric (disulfide-cross-linked) forms. Certain dimers also exist which contain nonreducible cross-links. The hexamers from the three membranes differ with respect to stoichiometry of subunits and subunit isoforms and to the degree of cross-linking of monomers into dimers. The minor subunits, M2* and M3, vary in quantity over a 20-fold range relative to the major ones among the three hexamers. The results indicate that: 1) at least two populations of triple-helical collagen molecules, differing in chain composition, exist in each membrane and that their relative proportions are tissue-specific; and 2) the chemical nature of the noncollagenous domain of these populations is tissue-specific with regard to subunit isoforms and relative proportion of reducible and nonreducible cross-links in dimers. A novel structural feature of the noncollagenous domain of basement membrane collagen was also evinced from these studies. Namely, that each of the four monomeric subunits exists in charge isoforms.

Amino Acids↗

PubMed1987

Localization of the Goodpasture epitope to a novel chain of basement membrane collagen.

The chain origins of subunits M1, M2*, and M3 previously described (Butkowski, R. L., Wieslander, J., Wisdom, B.J., Barr, J.F., Noelken, M.E., and Hudson, B.G. (1985) J. Biol. Chem. 260, 3739-3747) of the globular domain of basement membrane collagen were identified, by amino-terminal amino acid sequence analysis, with respect to their relationship to the chains of collagen IV. M1 comprises two polypeptides which correspond to the noncollagenous segments (NC1) of the alpha 1 ad alpha 2 chains of collagen IV. M2*, containing the Goodpasture epitope, and M3 are distinct from these two constituents and from each other but have Gly-X-Y triplets and hydroxyproline at their amino terminus, reflecting the fact that each has a collagen chain origin. These results indicate the presence of two new collagen chains in basement membrane. These new chains appear to be integral components of collagen IV molecules. Alternatively, they could represent new molecular species of basement membrane collagen containing a globular domain, comprising M2* and M3, with physicochemical properties very similar to those of collagen IV.

Amino Acid Sequence↗