scholarly journals Mesangial cells organize the glomerular capillaries by adhering to the G domain of laminin α5 in the glomerular basement membrane

2003 ◽  
Vol 161 (1) ◽  
pp. 187-196 ◽  
Author(s):  
Yamato Kikkawa ◽  
Ismo Virtanen ◽  
Jeffrey H. Miner

In developing glomeruli, laminin α5 replaces laminin α1 in the glomerular basement membrane (GBM) at the capillary loop stage, a transition required for glomerulogenesis. To investigate domain-specific functions of laminin α5 during glomerulogenesis, we produced transgenic mice that express a chimeric laminin composed of laminin α5 domains VI through I fused to the human laminin α1 globular (G) domain, designated Mr51. Transgene-derived protein accumulated in many basement membranes, including the developing GBM. When bred onto the Lama5 −/− background, Mr51 supported GBM formation, preventing the breakdown that normally occurs in Lama5 −/− glomeruli. In addition, podocytes exhibited their typical arrangement in a single cell layer epithelium adjacent to the GBM, but convolution of glomerular capillaries did not occur. Instead, capillaries were distended and exhibited a ballooned appearance, a phenotype similar to that observed in the total absence of mesangial cells. However, here the phenotype could be attributed to the lack of mesangial cell adhesion to the GBM, suggesting that the G domain of laminin α5 is essential for this adhesion. Analysis of an additional chimeric transgene allowed us to narrow the region of the α5 G domain essential for mesangial cell adhesion to α5LG3-5. Finally, in vitro studies showed that integrin α3β1 and the Lutheran glycoprotein mediate adhesion of mesangial cells to laminin α5. Our results elucidate a mechanism whereby mesangial cells organize the glomerular capillaries by adhering to the G domain of laminin α5 in the GBM.

1988 ◽  
Vol 251 (2) ◽  
pp. 411-418 ◽  
Author(s):  
L A Beavan ◽  
M Davies ◽  
R M Mason

Newly synthesized rat glomerular [35S]proteoglycans were labelled in vivo after injecting Na2[35S]SO4 intraperitoneally. At the end of the labelling period (7 h) the kidneys were perfused in situ with 0.01% (w/v) cetylpyridinium chloride. This fixed proteoglycans in the tissue and increased their recovery 2-3-fold during subsequent isolation of glomeruli from the renal cortex. The glomeruli were fractionated by a modified osmotic lysis and detergent extraction procedure [Meezan, Brendel, Hjelle & Carlson (1978) in The Biology and Chemistry of Basement Membranes (Kefalides, N.A., ed.), Academic Press, New York; Kanwar & Farquhar (1979) Proc. Natl. Acad. Sci. U.S.A. 76, 4493-4497] to obtain a basement membrane preparation. The proteoglycans released at each stage of the procedure were characterized using DEAE-Sephacel ion-exchange chromatography, chondroitinase ABC and HNO2 digestion and Sepharose CL-4B gel-permeation chromatography. About 85% of the [35S]proteoglycans synthesized were of the heparan sulphate variety, the remainder being chondroitin sulphate proteoglycans. Three sizes of heparan sulphate proteoglycans were identified. The largest (HS1, Kav. 0.47) accounts for 44% of the total extractable heparan sulphates. About one third of HS1 were extracted from the glomerular basement-membrane fraction with 8 M-urea and 4 M-guanidine hydrochloride but the remainder were released from the glomerulus during preparation of the fraction. The two smaller molecules (HS2, Kav. 0.56 and HS3, Kav. 0.68) accounted for 27% and 28% of the extractable heparan sulphate respectively and were not associated with the basement membrane fraction. HS1, HS2 and HS3 were also isolated from non-fixed glomeruli labelled in vivo but with much lower recovery. In glomeruli labelled in vitro, heparan sulphate accounted for only 35% of the proteoglycans, the remainder being of the chondroitin sulphate type. Proteoglycans similar to HS1, HS2 and HS3 were present in glomeruli labelled in vitro but, in addition, a large, highly charged heparan sulphate (HS1a) was extracted from the glomerular basement-membrane fraction of these glomeruli. It accounted for 6% of the total heparan sulphate.


1979 ◽  
Vol 81 (1) ◽  
pp. 137-153 ◽  
Author(s):  
Y S Kanwar ◽  
M G Farquhar

Cationized ferritin (CF) of narrow pI range (7.3-7.5) and the basic dye ruthenium red (RR) have been used as cationic probes to partially characterize anionic sites previously demonstrated in the glomerular basement membrane (GBM). When CF was given i.v. to normal rats and the left kidney was fixed by perfusion 15 min thereafter, clusters of CF molecules were found throughout the lamina rara interna (LRI), lamina rara externa (LRE), and mesangial matrix distributed at regular (approximately 60 nm) intervals. When kidneys were perfused with aldehyde fixative containing RR, small (20 nm) RR-stained particles were seen in the same locations distributed with the same 60 nm repeating pattern, forming a quasiregular, lattice-like arrangement. Fine (approximately 3 nm) filaments connected the sites and extended between them and the membranes of adjoining endothelial and epithelial cells. When CF was given i.v. followed by perfusion with RR in situ, both probes localized to the same sites. CF remained firmly bound after prolonged perfusion with 0.1-0.2 M KCl or NaCl. It was displaced by perfusion with buffers of high ionic strength (0.4-0.5 M KCl) or pH (less than 3.0 or greater than 10.0). CF also bound (clustered at approximately 60 nm intervals) to isolated GBM's, and binding was lost when such isolated GBM's were treated with buffers of high ionic strength or pH. These experiments demonstrate the existence of a quasi-regular, lattice-like network of anionic sites in the LRI and LRE and the mesangial matrix. The sites are demonstrable in vivo (by CF binding), in fixed kidneys (by RR staining), and in isolated GBM's (by CF binding). The results obtained with CF show that the binding of CF (and probably also RR) to the laminae rarae is electrostatic in nature since it is displaced by treatment with buffers of high ionic strength or pH. With RR the sites resemble in morphology and staining properties the proteoglycan particles found in connective tissue matrices and in association with basement membranes in several other locations.


1966 ◽  
Vol 124 (3) ◽  
pp. 431-442 ◽  
Author(s):  
Richard A. Lerner ◽  
Frank J. Dixon

Serum globulin from donor sheep made nephritic by immunization with glomerular basement membrane and subsequently nephrectomized contained specific kidney-fixing antibody and was capable of inducing an immediate, although transient, glomerulonephritis when injected into unilaterally nephrectomized lambs. This nephritis was characterized by immediate proteinuria, PMN infiltration into the glomerulus, and localization of γG- and ß1C-globulins in a linear fashion along the recipients' glomerular capillary walls. The nephritogenic property of the serum could be absorbed in vitro with isolated sheep glomerular basement membranes.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Alexander Winkler ◽  
Emanuel Zitt ◽  
Hannelore Sprenger-Mähr ◽  
Afschin Soleiman ◽  
Manfred Cejna ◽  
...  

Abstract Background Anti-glomerular basement membrane disease (GBM) disease is a rare autoimmune disease causing rapidly progressive glomerulonephritis and pulmonary haemorrhage. Recently, an association between COVID-19 and anti-glomerular basement membrane (anti-GBM) disease has been proposed. We report on a patient with recurrence of anti-GBM disease after SARS-CoV-2 infection. Case presentation The 31-year-old woman had a past medical history of anti-GBM disease, first diagnosed 11 years ago, and a first relapse 5 years ago. She was admitted with severe dyspnoea, haemoptysis, pulmonary infiltrates and acute on chronic kidney injury. A SARS-CoV-2 PCR was positive with a high cycle threshold. Anti-GBM autoantibodies were undetectable. A kidney biopsy revealed necrotising crescentic glomerulonephritis with linear deposits of IgG, IgM and C3 along the glomerular basement membrane, confirming a recurrence of anti-GBM disease. She was treated with steroids, plasma exchange and two doses of rituximab. Pulmonary disease resolved, but the patient remained dialysis-dependent. We propose that pulmonary involvement of COVID-19 caused exposure of alveolar basement membranes leading to the production of high avidity autoantibodies by long-lived plasma cells, resulting in severe pulmonary renal syndrome. Conclusion Our case supports the assumption of a possible association between COVID-19 and anti-GBM disease.


1997 ◽  
Vol 136 (2) ◽  
pp. 433-444 ◽  
Author(s):  
Rong-Rong Wu ◽  
John R. Couchman

Basement membranes contain several proteoglycans, and those bearing heparan sulfate glycosaminoglycans such as perlecan and agrin usually predominate. Most mammalian basement membranes also contain chondroitin sulfate, and a core protein, bamacan, has been partially characterized. We have now obtained cDNA clones encoding the entire bamacan core protein of Mr = 138 kD, which reveal a five domain, head-rod-tail configuration. The head and tail are potentially globular, while the central large rod probably forms coiled-coil structures, with one large central and several very short interruptions. This molecular architecture is novel for an extracellular matrix molecule, but it resembles that of a group of intracellular proteins, including some proposed to stabilize the mitotic chromosome scaffold. We have previously proposed a similar stabilizing role for bamacan in the basement membrane matrix. The protein sequence has low overall homology, apart from very small NH2- and COOH-terminal motifs. At the junctions between the distal globular domains and the coiled-coil regions lie glycosylation sites, with up to three N-linked oligosaccharides and probably three chondroitin chains. Three other Ser-Gly dipeptides are unfavorable for substitution. Fusion protein antibodies stained basement membranes in a pattern commensurate with bamacan, and they also Western blotted bamacan core protein from rat L2 cell cultures. The antibodies could also specifically immunoprecipitate an in vitro transcription/translation product from a full-length bamacan cDNA. The unusual structure of this proteoglycan is indicative of specific functional roles in basement membrane physiology, commensurate with its distinct expression in development and changes in disease models.


Author(s):  
Boyang Xu ◽  
Li Zhu ◽  
Qingsong Wang ◽  
Yanfeng Zhao ◽  
Meng Jia ◽  
...  

Abstract Background IgA nephropathy (IgAN) is characterized by predominant IgA deposition in the glomerular mesangium. Previous studies proved that renal-deposited IgA in IgAN came from circulating IgA1-containing complexes (CICs). Methods To explore the composition of CICs in IgAN, we isolated CICs from IgAN patients and healthy controls, and then quantitatively analyzed them by mass spectrometry. Meanwhile, the isolated CICs were used to treat human mesangial cells to monitor mesangial cell injury. Taken together the proteins content and injury effects, the key constituent in CICs was identified. Then, the circulating levels of identified key constituent-IgA complex were detected in an independent population by an in-house-developed ELISA. Results By comparing the proteins of CICs between IgAN patients and controls, we found that 14 proteins showed significantly different levels. Among them, alpha-1-microglobulin content in CICs was associated with not only in vitro mesangial cell proliferation and MCP-1 secretion but also in vivo eGFR levels and tubulointerstitial lesions in IgAN patients. Moreover, we found alpha-1-microglobulin was prone to bind aberrant glycosylated IgA1. Additionally, an elevated circulating IgA-alpha-1-microglobulin complex levels were detected in an independent IgAN population, and IgA-alpha-1-microglobulin complex levels were correlated with hypertension, eGFR levels and Oxford-T scores in these IgAN patients. Conclusions Our results suggest that the IgA-alpha-1-microglobulin complex is an important constituent in CICs, and that circulating IgA-alpha-1-microglobulin complex detection might serve as a potential noninvasive biomarker detection method for IgAN.


1982 ◽  
Vol 242 (4) ◽  
pp. F385-F389
Author(s):  
M. P. Cohen ◽  
M. L. Surma ◽  
V. Y. Wu

Glomerular basement membrane (GBM) was labeled in vivo by the injection of tracer amounts of tritiated proline into normal and streptozotocin-diabetic rats. Basement membrane biosynthesis and turnover were determined from the specific activities of proline and hydroxyproline in samples purified following osmotic lysis of glomeruli isolated 4 h to 12 days after injection. Peak radiolabeling of normal and diabetic GBM occurred within 24-48 h and 48-72 h, respectively, and, when corrected for differences in the serum proline specific activities, [3H]proline incorporation was greater in diabetic than in normal samples. In contrast to the subsequent time-dependent progressive decline in radiolabeling in basement membranes from normal animals, specific activities of proline and hydroxyproline in diabetic glomerular basement membrane did not change significantly over the same period of observation. Renal cortical mass and glomerular basement membrane collagen content were preserved in diabetic animals despite loss of body weight. The findings are compatible with prolongation of glomerular basement membrane turnover in experimental diabetes, and suggest that diminished degradation contributes to the accumulation of glomerular basement membrane that is characteristic of chronic diabetes.


1971 ◽  
Vol 25 (03) ◽  
pp. 507-516 ◽  
Author(s):  
Chung-Hsin Ts'ao

SummaryPurified canine glomerular basement membrane (BM) induced platelet aggregation when added to heparinized platelet-rich plasma (PRP) of the rat. Platelet aggregation induced by BM suspension was compared with that induced by collagen submicroscopically. When aliquots of BM or collagen suspension of the same concentration (2 mg/ml saline) was incubated with PRP, platelet-BM reaction was far less pronounced than platelet-collagen reaction. Platelet-BM reaction was slow and aggregates were small; swelling and pseudopod formation were obvious but platelet degranulation was limited. With high concentration (5 mg/ml saline) of BM suspension, the aggregation time was shortened and aggregates were generally composed of larger number of platelets. Treatment of BM with collagenase abolished the platelet-BM reaction. It is postulated that similar “platelet aggregating” elements in collagen are present in BM; but the quantity of these elements is less in a BM than in a collagen molecule.


1993 ◽  
Vol 289 (3) ◽  
pp. 647-652 ◽  
Author(s):  
W D Comper ◽  
A S N Lee ◽  
M Tay ◽  
Y Adal

Estimates of levels of glomerular and glomerular-basement-membrane anion charge should serve as useful quantitative markers for the integrity of the tissues in health and disease. We have developed a simple, rapid, technique to measure this charge through the use of ion exchange with radioisotopes 22Na+ and 36Cl- at low ionic strengths in phosphate buffer. When this technique is used, normal glomeruli isolated from rat have a measured net anion charge concentration of 17.4 +/- 3.7 p-equiv. per glomerulus (n = 20). Perfused rat kidneys that lose approximately half of their glomerular heparan [35S]sulphate content (owing to oxygen-radical damage) exhibited a lower anion charge, of 7.5 +/- 1.6 p-equiv. per glomerulus (n = 5). Glomerular basement membranes prepared from rat glomeruli by a sonication-centrifugation procedure in the presence of enzyme inhibitors had a charge concentration of 6.3 +/- 0.7 mu-equiv./g wet wt. of tissue (n = 4), whereas membranes prepared by sonication, centrifugation, DNAse and detergent treatment had a charge concentration of 7.1 +/- 1.6 mu-equiv./g wet wt. (n = 4). Isotope-dilution experiments with 3H2O on these detergent-prepared glomerular basement membranes demonstrated that they had a water content of approx. 93%, which would then give a net anion charge concentration of 7.6 +/- 1.7 m-equiv./l (n = 4). These values are in good agreement with those obtained by others using titration techniques [Bray and Robinson (1984) Kidney Int. 25, 527-533]. The relatively low magnitude of glomerular anion charge in normal kidneys is consistent with other recent findings that glomerular anion charge is too low to affect the glomerular transport of charged molecules in a direct, passive, biophysical manner through electrostatic interactions.


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