S–laminin/laminin β2, a homologue of the widely distributed laminin B1/β1 chain, is a major component of adult renal glomerular basement membrane (GBM). Immature GBM bears p1, which is replaced by β2 as development proceeds. In mutant mice that lack β2, the GBM remains rich in β1, suggesting that a feedback mechanism normally regulates GBM maturation. The β2–deficient GBM is structurally intact and contains normal complements of several collagenous and noncollagenous glycoproteins. However, mutant mice develop massive proteinuria due to failure of the glomerular filtration barrier. These results support the idea that laminin β chains are functionally distinct although they assemble to form similar structures. Laminin β2–deficient mice may provide a model for human congenital or idiopathic nephrotic syndromes.

The renal glomerulus of mice lacking s–laminin/laminin β2: nephrosis despite molecular compensation by laminin β1

The distribution and localization of a glioma-associated antigen defined by monoclonal antibody 81C6 has been examined using human cultured cell lines and tissues. Monoclonal antibody 81C6 was selected from a hybridoma fusion of spleen cells of mice immunized with the glial fibrillary acidic protein-positive human glioma cell line U-251 MG. Results of cell surface radioimmunoassay and absorption analysis demonstrated that 81C6 defined a glioma-mesenchymal extracellular matrix (GMEM) antigen expressed by 14 of 16 gliomas, 1 of 3 neuroblastomas, 1 of 7 melanomas, 2 of 6 sarcoma cell lines, and 8 of 9 cultured fibroblast lines. GMEM was not expressed by carcinoma or by the myeloid-lymphoid cell lines examined. Within the central nervous system, GMEM was expressed in 10 of 11 glioblastomas but was undetected in 5 of 6 astrocytomas and in normal adult and fetal brain by peroxidase-antiperoxidase immunohistology. In glioblastomas, the GMEM antigen was localized to basement membranes of the distinctive glomeruloid endothelial proliferations and hyperplastic blood vessels. The GMEM antigen was also expressed in 3 of 3 glioblastoma cell lines and 6 of 8 glioblastoma biopsy xenografts in athymic nude mice. Among non-central nervous system tissues and tumors, GMEM was found by peroxidase-antiperoxidase immunohistology in normal liver sinusoids, spleen red pulp sinusoids, kidney medullary tubule interstitium, and glomerular mesangium and in association with vascular and stromal elements of several undifferentiated tumors. The GMEM antigen is distinct from previously described forms of fibronectin, laminin, collagen types I to V, hyaluronic acid, chondroitin sulfate, and heparin, as determined by absorption analysis and immunohistological localization in tissues. The expression of GMEM in glioblastoma but not normal brain, association with glioblastoma-proliferative endothelium basement membranes, and expression in glioblastoma cell lines and nude mouse xenografts suggest that GMEM may be a useful marker of gliomas in vivo and in vitro.

https://cancerres.aacrjournals.org/content/canres/43/6/2796.full.pdf

Human glioma-mesenchymal extracellular matrix antigen defined by monoclonal antibody.

Glomerular visceral epithelial cells, also termed podocytes, are highly specialized epithelial cells that cover the outer aspect of the glomerular basement membrane. Recent studies point to an important role of podocytes in the physiology and pathophysiology of the glomerulus. This review summarizes the structure-function relationships of podocytes. Following a description of the general morphology of podocytes, the technical problems associated with studying these cells are discussed. A survey of podocyte function forms the center of this review. Finally, selected aspects of podocyte development and cell division are discussed.

Structure and function of podocytes: an update

Collagen IV is a major structural component of all basal laminae (BLs). Six collagen IV alpha chains are present in mammals; alpha 1 and alpha 2(IV) are broadly expressed in embryos and adults, whereas alpha 3-6(IV) are restricted to a defined subset of BLs. In the glomerular BL of the kidney, the alpha 1 and alpha 2(IV) chains are replaced by the alpha 3-5(IV) chains as development proceeds. In humans, mutation of the collagen alpha 3, alpha 4, or alpha 5(IV) chain genes results in a delayed onset renal disease called Alport syndrome. We show here that mice lacking collagen alpha 3(IV) display a renal phenotype strikingly similar to Alport syndrome: decreased glomerular filtration (leading to uremia), compromised glomerular integrity (leading to proteinuria), structural changes in glomerular BL, and glomerulonephritis. Interestingly, numerous changes in the molecular composition of glomerular BL precede the onset of renal dysfunction; these include loss of collagens alpha 4 and alpha 5(IV), retention of collagen alpha 1/2(IV), appearance of fibronectin and collagen VI, and increased levels of perlecan. We suggest that these alterations contribute, along with loss of collagen IV isoforms per se, to renal pathology.

/pdf/molecular-and-functional-defects-in-kidneys-of-mice-lacking-1jgshs0op9.pdf

Molecular and functional defects in kidneys of mice lacking collagen alpha 3(IV): implications for Alport syndrome.

Neutrophil emigration in the lung differs substantially from that in systemic vascular beds where extravasation occurs primarily through postcapillary venules. Migration into the alveolus occurs directly from alveolar capillaries and appears to progress through a sequence of steps uniquely influenced by the cellular anatomy and organization of the alveolar wall. The cascade of adhesive and stimulatory events so critical to the extravasation of neutrophils from postcapillary venules in many tissues is not evident in this setting. Compelling evidence exists for unique cascades of biophysical, adhesive, stimulatory, and guidance factors that arrest neutrophils in the alveolar capillary bed and direct their movement through the endothelium, interstitial space, and alveolar epithelium. A prominent path accessible to the neutrophil appears to be determined by the structural interactions of endothelial cells, interstitial fibroblasts, as well as type I and type II alveolar epithelial cells.

https://www.physiology.org/doi/pdf/10.1152/physrev.00023.2002

Unique Structural Features That Influence Neutrophil Emigration Into the Lung

Entactin is a sulfated glycoprotein in the extracellular basement membrane like matrix produced by M1536-B3 cells, a mouse endodermal line derived from an embryonal carcinoma. It has a molecular weight of 158,000 and is chemically and immunologically distinguishable from GP-2 (laminin) and fibronectin. Antibodies produced against entactin and GP-2 react with subepithelial and vascular basement membranes in rat lung, liver, spleen, and kidney and mouse placenta and kidney when examined by light microscopy. Both antibodies yield staining around the marginal sinus of the white pulp of the spleen. Antientactin reacts with basement membrane and mesangium in rat glomeruli, and anti-GP2 does not. Ultrastructurally, staining in kidneys is strongest at epithelial or endothelial cell membranes bordering basement membranes, with only moderate staining of the basement membrane proper. Intracellular staining is not present. The location of entactin suggests that it has a role in the interaction of cells with extracellular matrix, possibly in adhesion. Lack of intracellular staining suggests that the tissues studied are not actively producing entactin or GP-2 and that these substances may be fairly stable in adult organisms.

Immunolocalization of entactin, a sulfated basement membrane component, in rodent tissues, and comparison with GP-2 (laminin).

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

A E Chung

Author Tools

Chat about Author

Papers

Immunolocalization of entactin, a sulfated basement membrane component, in rodent tissues, and comparison with GP-2 (laminin).