Extra domain A-fibronectin (EDA-FN)

Extra domain A-fibronectin is an **alternatively spliced isoform** of the extracellular matrix glycoprotein **fibronectin** that contains the type III repeat "extra domain A" (EDA). This variant is produced primarily during **tissue injury**, **embryonic development**, and various pathological conditions such as inflammation, fibrosis, cancer progression, and cardiovascular disease. The presence of the EDA segment alters fibronectin’s physical properties within the extracellular matrix—affecting fibrillogenesis and mechanical stiffness—and modulates cellular responses including pH homeostasis, survival signaling pathways like TGF-beta signaling, cell adhesion/migration/proliferation dynamics[1][2]. Functionally distinct from plasma fibronectin (which lacks extra domains), cellular forms containing EDA are upregulated in response to stress or damage. Mechanistically important is their ability to interact with pattern recognition receptors such as Toll-like receptor 4 (**TLR4**), thereby promoting inflammatory gene expression similar to bacterial lipopolysaccharide stimulation[5][6]. In vascular biology specifically, Fn containing extra domain A has been shown to promote arterial thrombosis via platelet TLR4 activation. In oncology research and drug development contexts it serves both as a marker for tumor stroma remodeling and a potential target for selective delivery strategies due to its restricted expression profile outside normal adult tissues except during active remodeling processes[2][4]. No FDA-approved drugs currently target this molecule directly; however investigational approaches include monoclonal antibodies against Fn–EDA being explored in cancer diagnostics/therapeutics.

Other names

EDA-FNFn-EDAFN-EDAFN1 EDA isoformCellular fibronectin containing extra domain AType III repeat extra domain A of fibronectin