Human FSTL1 ELISA Kit

Kit Components

 1. Recombinant Human FSTL1 standard: 2 vials

 2. One 96-well plate coated with Human FSTL1  Ab

 3. Sample diluent buffer: 12 mL - 1

 4. Detection antibody: 130 µL, dilution 1:100

 5. Streptavidin-HRP: 130 µL, dilution 1:100

 6. Antibody diluent buffer: 12 mL x1   

 7. Streptavidin-HRP diluent buffer: 12 mL x1

 8. TMB developing agent: 10 mL x1

9. Stop solution: 10 mL x1

10. Washing solution (20x): 25 mL x1

Background

Follistatin-like 1 (FSL1 or FSTL1), also known as FRP (follistatin-related protein), Flik (follistatin-like), and TSC-36 (TGF-β1-stimulated clone 36), is a secreted extracellular glycoprotein belonging to the BM-40/SPARC/Osteonectin family. The human FSTL-1 is a 308 amino acid (aa) precursor protein composed of a 20 aa signal sequence, a cysteine-rich Follistatin (EGF and kazal-like) domain, two apparently non-functional EF-hand calcium-binding motifs, and a von Willebrand Factor C homology domain. Mature human FSTL1 shares 94% and 95% aa identity with mouse, rat FSTL1, respectively. FSTL1 is a common rheumatoid arthritis auto-antigen in human. It prevents autoimmune arthritis by inhibiting matrix metalloproteinase (MMP) and prostaglandin expression. It promotes inflammatory cytokine secretion and exhibits pro-inflammatory activity. In muscle and heart, it shows protective activity and promotes endothelial cell functions such as revascularization after ischemia. Cardiac and circulating FSTL1 is generally increased in conditions such as heart failure and acute coronary syndrome. In addition, expression of FSTL1 is down-regulated in many human cancers. In vitro, it slows proliferation and MMP-dependent migration, and increases FAS-dependent apoptosis of tumor cell lines, suggesting that FSL1 may be a tumor suppressor.