Disease relevance of FN1

• Adherence of Pasteurella multocida to fibronectin [1].
• Laminin was isolated from the mouse EHS tumor and fibronectin from human plasma [2].
• Elevated levels of fibronectin (Fn) in articular cartilage have been linked to the progression of both rheumatoid and osteoarthritis [3].
• Both brain and pituitary FGF are mitogenic for low density human umbilical endothelial (HUE) cell cultures maintained on either fibronectin- or laminin-coated dishes or on biomatrices produced by cultured cells such as bovine corneal endothelial cells or the teratocarcinoma cell line PF-HR-9 [4].
• Moreover, these results, in addition to those previously reported for fibronectin, suggest that the platelet defect in Glanzmann thrombasthenia is not limited to decreased binding of fibrinogen but involves several glycoproteins that are known to interact with platelets [5].

High impact information on FN1

• The distribution of fibronectin on human fibroblast surfaces during initial attachment and spreading was studied by indirect immunofluorescence analysis using a monospecific anti-cold-insoluble globulin antiserum [6].
• Plasma membrane receptors have been described for components of the extracellular matrix such as fibronectin, laminin and various collagen types [7].
• At this molecular level we find that the phospholipid lateral diffusion coefficient is dependent on the substrate upon which cells are allowed to adhere (collagen, fibronectin or a natural basement membrane) and on the topography of the cell (basal versus apical plasma membrane) [7].
• We now report that fibronectin, which is a high molecular weight glycoprotein present in blood, connective tissue and at cell surfaces, binds specifically to Trypanosoma cruzi trypomastigotes [8].
• Human keratinocytes, derived from the skin of newborns and of adults, were grown in the complete absence of serum, in a hormone-supplemented medium on fibronectin-coated cell culture dishes at low seed density [9].

Chemical compound and disease context of FN1

• Modification of the mycoplasma surface charge by blocking of carboxyl groups or neutralization of ionic lipids by tetracaine altered the attachment level, whereas fibronectin and its corresponding antiserum were without effect [10].
• Components of osteoarthritis include increases in pericellular fibronectin and in chondrocyte beta1 integrin expression [11].
• All Treponema strains bound to the amino-terminal heparin I/fibrin I domain of fibronectin [12].
• Primary cultures of dorsal root ganglion neurons were cultured on F108-immobilized FN or, as a control, on FN adsorbed from solution directly to polystyrene [13].
• A strongly elevated fibronectin content is an early feature in osteoarthritis and appears to be related to increases in both the synthesis and retention of this glycoprotein [14].

Biological context of FN1

• Furthermore, the 204 COOH-terminal amino acid sequence of bovine FN was completed by overlapping two peptide fragments (MrS 3,000 and 23,000) [15].
• A bovine fibronectin (FN) cDNA clone (pFB1) was isolated by screening a cDNA library of calf testis fibroblasts with a synthetic oligonucleotide probe [15].
• Characterization of the expression of the alternative splicing of the ED-A, ED-B and V regions of fibronectin mRNA in bovine ovarian follicles and corpora lutea [16].
• Vessel wall subendothelial extracellular matrix, a dense mesh formed of collagens, fibronectin, laminin, and proteoglycans, has important roles in lipid and lipoprotein retention and cell adhesion [17].
• To test whether removal of HSPG exposes fibronectin, a candidate Lp(a) binding protein in the matrix, antifibronectin antibodies were used [17].

Anatomical context of FN1

• For many pathogens, adherence and/or invasion involve association with host extracellular matrix molecules, such as fibronectin (Fn) [1].
• Thus follicles and corpora lutea express isoforms of fibronectin usually expressed in developing tissues [16].
• Bovine ovarian follicles (0.5-9 mm diameter) and corpora lutea (cyclic, early to late mid-luteal phase) were shown to express ED-A+, ED-A-, ED-B+, ED-B-, V+ and V fibronectin isoforms, similar to the liver, lung and kidney of fetuses, but generally not of adult animals [16].
• Adherence of chondrocytes to fibronectin enhanced proteoglycan synthesis by twofold (vs. albumin) [3].
• Endothelial cell growth can be controlled in chemically-defined medium by varying the density of FN coated on the substratum (Ingber, D. E., and J. Folkman. J. Cell Biol. 1989. 109:317-330) [18].

Associations of FN1 with chemical compounds

• Three carbohydrate groups (two glucosamine-based and one galactosamine-based) were identified, giving a total of eight carbohydrate groups in the longest splice variant of bovine plasma fibronectin [19].
• Removal of polysaccharide capsule enhanced the binding capacity of the bacterium to Fn and inhibition by Hep [1].
• Fibronectin is an extracellular matrix glycoprotein [16].
• In this study, we examined intracellular events which follow ligation of Fn to its receptor, the integrin alpha5beta1 [3].
• Factor XIIIa-dependent covalent cross-linking of vWF to collagen, but not to fibronectin or laminin, was also demonstrated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate [20].

Physical interactions of FN1

• The C-terminal portion of BSP-30K is organized in a tandem of 40-44-residue domains each sharing the consensus pattern of the gelatin-binding fibronectin type II module [21].
• We have previously shown that both heparin and fibronectin have two binding sites on the TSP-1 subunit which may require conformational change for their occupancy (R. Dardik and J. Lahav, 1987, Eur. J. Biochem. 168, 347; ibid 1989, 185, 581) [22].
• The combination of SP and IGF-1 significantly increased the number of cells attached to the fibronectin matrix and the expression of integrin alpha 5 [23].
• Further, osteoblastic cells on the grooved surfaces also displayed a strong labelling for fibronectin at the cytoplasmic extensions coupled with intense osteonectin expression in comparison to the rough surfaced implants [24].
• Adhesion to a 60 kd tryptic fragment of fibronectin that is not involved in integrin-mediated cell binding was also increased by TGF-beta [25].

Regulatory relationships of FN1

• Fibronectin fragments upregulate insulin-like growth factor binding proteins in chondrocytes [26].
• After transient transfection of cDNA of the constitutively active (CA) mutant of TbetaR-I, the production of laminin and fibronectin was stimulated even in the absence of TGF-beta [27].
• Electric field-directed cell motility involves up-regulated expression and asymmetric redistribution of the epidermal growth factor receptors and is enhanced by fibronectin and laminin [28].
• These results demonstrate that cellular outgrowth from bovine ICM is supported by fibronectin and is stimulated by TIMP-2 [29].
• Bone morphogenetic protein-induced chondrogenesis in outgrowths of muscle connective tissues on various furrowed and unfurrowed fibronectin-coated substrata was observed by biochemical and histologic methods [30].

Other interactions of FN1

• The presence of endogenously produced active TGF-beta in the culture media was shown to modulate the behavior of the cell cultures as evidenced by the effects of TGF-beta-neutralizing antisera on cell size and fibronectin production [31].
• The results of distance geometry and restrained molecular dynamics calculations indicate that the global fold of the PDC-109 b domain, a type II module related to those found in fibronectin, is somewhat different from that predicted by modeling the structure on the basis of homology between type II and kringle units [32].
• Seven days of retinoic acid treatment resulted in decreased attachment to fibronectin, MGP, and collagen [33].
• The collagen-binding domain of bovine fibronectin (type II sequence) was also found to be highly homologous to both BSP-A3 and PDC-109 [34].
• Cyclic compression of articular cartilage at 0.1 Hz and higher was consistently associated with a dramatic increase in the synthesis of COMP as well as fibronectin [35].

Analytical, diagnostic and therapeutic context of FN1

• Southern blot studies suggest that human FN is coded by a unique gene [15].
• PCR products from bovine fetal liver cDNA were determined to be bovine fibronectin by the correct product size and DNA sequence homology to other species, and to the known bovine amino acid sequence [16].
• Based upon the timing of appearance of conditioning factors on the substratum and the immunofluorescence patterns, it seems that the diffusely organized fibronectin on the substratum constitutes the sites to which cell attachment occurs [6].
• Intravenous injection of bovine serum albumin-antibovine serum albumin complexes or colloidal carbon was combined with histological staining for endogenous peroxidase, fibronectin, laminin, or a lectin, Bandeiraea simplicifolia agglutinin I [36].
• Bovine aortic endothelial cell (BAEC) attachments to laminin, fibronectin, and fibrinogen are inhibited by soluble arginine-glycine-aspartate (RGD)-containing peptides, and YGRGDSP activity is responsive to titration of either soluble peptide or matrix protein [37].

References