It is now generally accepted that adherence of microorganisms to various components of cardiac valve surfaces or vegetation lodging on the heart valves is an important early event in the pathogenesis of infective endocarditis. 120 clinical isolates of S. aureus obtained from patients with endocarditis and wound infections and from nasopharyngeal carriers were quantitatively analysed in vitro for their ability to bind to fibronectin and to produce protein A and alpha-toxin. Both cell-bound and extracellular protein A were measured and alpha-toxin was determined as antigen and as haemolytic activity. The highest fibronectin binding ability was found in carrier strains while no significant differences between strains were observed regarding the production of protein A. Strains isolated from patients with endocarditis produced significantly lower amounts of alpha-toxin than did strains from the other two groups. An inverse relationship between the production of protein A and of alpha-toxin was noticed in the material. Animal passage of five strains in an experimental endocarditis model showed a good reproducibility of the test systems and one strain was upregulated in its fibronectin binding ability and in alpha-toxin production. These in vitro results indicate that the fibronectin binding ability is not the decisive adherence factor and question the role of alpha-toxin as a virulence factor in endocarditis.
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http://dx.doi.org/10.1016/s0934-8840(98)80182-5 | DOI Listing |
Int J Mol Sci
January 2025
Department of Pathology, Albert Szent-Györgyi Medical Center, Faculty of Medicine, University of Szeged, 6720 Szeged, Hungary.
Fibronectin glomerulopathy (FG) is caused by fibronectin 1 () gene mutations. A renal biopsy was performed on a 4-year-old girl with incidentally discovered proteinuria (150 mg/dL); her family history of renal disease was negative. Markedly enlarged glomeruli (mean glomerular diameter: 196 μm; age-matched controls: 140 μm), α-SMA-positive and Ki-67-positive mesangial cell proliferation (glomerular proliferation index 1.
View Article and Find Full Text PDFRespir Res
January 2025
Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI, 53792, USA.
Progressive forms of interstitial lung diseases, including idiopathic pulmonary fibrosis (IPF), are deadly disorders lacking non-invasive biomarkers for assessment of early disease activity, which presents a major obstacle in disease management. Excessive extracellular matrix (ECM) deposition is a hallmark of these disorders, with fibronectin being an abundant ECM glycoprotein that is highly upregulated in early fibrosis and serves as a scaffold for the deposition of other matrix proteins. Due to its role in active fibrosis, we are targeting fibronectin as a biomarker of early lung fibrosis disease activity via the PEGylated fibronectin-binding polypeptide (PEG-FUD).
View Article and Find Full Text PDFSci Rep
January 2025
Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
The poor prognosis of pancreatic cancer is often attributed to difficulties of early detection due to a lack of appropriate risk factors. Previously, we demonstrated the presence of Enterococcus faecalis (E. faecalis) in pancreatic juice and tissues obtained from patients with cancers of the duodeno-pancreato-biliary region, suggesting the possible involvement of this bacterial species in chronic and malignant pancreatic diseases.
View Article and Find Full Text PDFMath Biosci
January 2025
Department of Biomedical Engineering, Virginia Commonwealth University, 410 West Main St., Richmond, VA, 23284, USA. Electronic address:
One of the main drivers of fibrotic diseases is epithelial-mesenchymal transition (EMT): a transdifferentiation process in which cells undergo a phenotypic change from an epithelial state to a pro-migratory state. The cytokine transforming growth factor-β1 (TGF-β1) has been previously shown to regulate EMT. TGF-β1 binds to fibronectin (FN) fibrils, which are the primary extracellular matrix (ECM) component in renal fibrosis.
View Article and Find Full Text PDFIntegrins are a large family of heterodimeric receptors important for cell adhesion and signaling. Integrin α5β1, also known as the fibronectin receptor, is a key mediator of angiogenesis and its dysregulation is associated with tumor proliferation, progression, and metastasis. Despite numerous efforts, α5β1-targeting therapeutics have been unsuccessful in large part due to efficacy and off-target effects.
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