Recreating the natural cell niche is key to successful cultivation. The physical, topological, and biochemical expression of the different laminin isoforms in the BM is heterogeneous and tissue-specific.Â
Human recombinant laminin 421, Biolaminin 421 LN (LN421), supports several tissue-specific cell types such as endothelial cells and kidney cells and has been suggested to be important for renal, synaptic and inflammatory functions.
In the kidney, laminin 421 is produced by mesangial cells and is presumably important for the development and reparation of microvasculature and glomerulogenesis (Abrass, 2010) whereas kidney podocytes mainly bind to laminin 521 via the α3β1 integrin (Sachs and Sonnenberg, 2013). Laminin 421 has also been implicated in renal cell carcinomas (Lohi, 1996; Vainionpää, 2007) and glial brain tumors (Ljubimova, 2001).
In chemical synapses, the laminin 421 isoform is crucial for the correct localization of pre- and post-synaptic specializations. In mice lacking the laminin β2 chain, neuromuscular junctions fail to form active zones in the presynaptic terminal and thereby neurotransmitter release is disrupted (Patton, 2001). Laminin 421 has been shown to assist in the formation and stabilization of active zones by several mechanisms, including voltage-gated Ca2+-channels and integrins containing the α3 subunit (Carlsson, 2003; Cohen, 2000).
