Fig. 6.

Schematic drawing showing the effects of BMP signaling on the morphogenesis of hepatic cords. Assembly of hepatic cords requires the coordinated assembly of hepatoblasts and peri-sinusoidal mesenchymal cells. Proper BMP activity levels are important for coordinated assembly of the complex epithelial structure (middle row). When BMP was overexpressed, liver structure was not affected. Over-expression of BMP promoted hepatoblast differentiation (upper row). When BMP signaling was suppressed, liver structure was disrupted and cells formed clusters, leading to abnormal fibronectin deposition and dilated sinusoidal space (lower row). Thus BMP signaling is important for regulating interactions between hepatoblast and peri-sinusoidal cells for organizing the hepatic cord and its 3D ECM