Figure 4

Schematic of dysregulated TGF-β/BMP expression in AVM endothelial cells. Levels of both circulating and intracellular TGF-β1 were elevated in AVM patients when compared to controls while intracellular BMP-9 levels were lower in AVM patients. Protein levels of components of the ALK1 → Smad1/5/8 → Smad6 pathway were decreased in AVM patients despite an increase in mRNA levels while Smads downstream of TGF-β1 → ALK5 activation demonstrated normal mRNA expression and elevated protein levels.