Disease relevance of FN1

• BACKGROUND: Borrelia Burgdorferi has a predilection for collagenous tissue and can interact with fibronectin and cellular collagens [1].
• Immunopathologic studies using laminin, bullous pemphigoid antigen, and fibronectin indicate that, despite the increased inflammatory response seen in homografts, the epithelial surface is normal [2].
• Medial fibrosis occurred to the same extent as in control grafts, as did the early appearance of platelet factor VIII and fibronectin and the lack of vasa vasorum at 3 days followed by reappearance at 7 days [3].
• The findings of this study indicate that fibronectin use resulted in enhanced healing by early replacement of the fibrin clot, increased connective tissue cell proliferation, reduction of the inflammatory response, and inhibition of both cementum resorption and dentoalveolar ankylosis [4].

High impact information on FN1

• Recent studies have reported improved efficiency by including stromal cells (STR), or the fibronectin fragment CH-296 (FN), and various cytokines such as flt3 ligand (FLT) during ex vivo culture and transduction in nonhuman primates [5].
• Antibodies to vascular basement membrane and matrix markers laminin, fibronectin, and collagen types I and VIII, and antisera recognizing cell cycle-specific nuclear proteins (cyclin, Ki-67, Mib-1) also were used [6].
• METHODS: The impact of culture and transduction on rhesus macaque CD34+ peripheral blood stem cells (PBSCs) was assessed in the presence of FN and stimulatory cytokines [7].
• In the current study, we investigated whether prolonged culture and transduction in the presence of the carboxy-terminal portion of fibronectin (FN) could maintain or expand retrovirally transduced repopulating hematopoietic stem cells (HSCs) [7].
• Levels of FFN in amnion increase with the onset of labor in rhesus monkeys [8].

Biological context of FN1

• Since glucocorticoid (GC) levels in serum and amniotic fluid increase in association with parturition, we compared GC-mediated regulation of FFN expression in cultures of amnion epithelial cells and fibroblasts isolated from human and baboon amnions [8].
• We studied the composition of this material in placentas collected from 22-34 days of gestation by using immunoperoxidase techniques directed to the extracellular matrix molecules fibronectin, type IV collagen, and laminin [9].
• Fibronectin-treated areas showed significantly increased cellular proliferation (P less than 0.01) during the first 2 weeks, affecting mainly all the supracrestal tissues [10].
• Fibronectin mat implants impregnated with NGF have been successfully used in rat nerve regeneration model [11].
• This result, together with the comparison of these filaments with microfibril-associated 1.2-3 nm wide fibronectin filaments and the reported abundance of fibronectin in the basement membrane area during odontogenesis, indicates that these 1.5-3 nm wide filaments are composed of fibronectin [12].

Anatomical context of FN1

• We conclude that GC differentially regulates FFN expression in epithelial and mesenchymal cells from amnion and placenta [8].
• CONCLUSIONS: These results suggest that culture on FN support allows prolonged ex vivo maintenance and even expansion of transduced repopulating stem cells [7].
• Cultured simian astrocytes expressed vimentin, laminin, and fibronectin [13].
• As macrophages, they expressed in vitro CD68, CD64, CD14, CD11b, MHC class II, and fibronectin [13].
• During this period the trophoblast cells in the proximal shell reorganized, forming strands of cells that were separated by bands of matrix immunoreactive for type IV collagen, laminin, and fibronectin [14].

Associations of FN1 with chemical compounds

• Cells were maintained with and without dexamethasone (DEX), and levels of FFN in the conditioned media were determined by ELISA [8].
• Aqueous humor fibronectin levels were determined in four monkeys after approximately 9.5 weeks of timolol + dorzolamide treatment [15].
• Our findings indicate that timolol affects neither ciliary epithelial transport of ascorbate nor aqueous fibronectin levels [15].
• Surfaces on the experimental sides were decalcified with citric acid, and after thorough rinsing, the inner aspect of the flaps and the roots were bathed with 1 ml of autologous plasma fibronectin in normal saline (400 micrograms m/ml) and the flaps sutured [10].
• Immunoperoxidase staining showed that these structures contained major basement membrane components including laminin, heparan sulfate proteoglycan, type IV collagen, as well as fibronectin [16].

Regulatory relationships of FN1

• In the absence of serum, VEGF stimulated proliferation of UEA-1 (+) cells plated on fibronectin but not collagen I, whereas in the presence of 10% fetal calf serum, both matrices supported VEGF-induced mitogenesis [17].

Other interactions of FN1

• We have previously described a novel integrin beta-subunit, beta 6, which is expressed in cultured epithelial cells. beta 6 can associate with alpha v to form the fibronectin-binding heterodimer alpha v beta 6 [18].

Analytical, diagnostic and therapeutic context of FN1

• Northern blots revealed that DEX reduced levels of fibronectin (FN) mRNA in amnion epithelial cells and cytotrophoblasts, whereas it increased FN mRNA in amnion and placental fibroblasts [8].
• The synthesis and secretion of von Willebrand factor (VWF, or Factor VIII-related antigen) and fibronectin by cultured endothelial cells from rhesus monkey choroid retina were demonstrated by immunofluorescence, immunoperoxidase and single radial immunodiffusion techniques [19].
• On each of the remaining teeth, the root surface and the inner walls of the socket were bathed with 1 ml of fibronectin in saline solution (400 micrograms/ml) during the 5-minute interval between tooth extraction and its replantation [4].
• The distribution of fibronectin (FN), laminin (LM), hyaluronic acid (HA) and chondroitin sulfate (CS) were examined by peroxidase immunocytochemistry in long-tailed monkey embryos during the period of neural tube and notochord formation (stages 8-11) [20].

References