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.
Human recombinant laminin 332, Biolaminin 332 LN (LN332), is highly enriched in epithelial basement membranes, lining surfaces of the body such as the skin, hair follicles, oral cavity, gastrointestinal and urinary tract, lungs, and different glands.
Laminin 332 highly influences keratinocyte proliferation and mediates a strong adhesion of keratinocytes to the basement membrane through hemidesmosome protein complex (Ghohestani, 2001).
The importance of laminin 332 mediated adhesion in the skin is also evident in the human blistering disease Junctional Epidermolysis Bullosa, which is associated with laminin-332 gene mutations (DiPersio, 1997).
The expression of laminin 332 is upregulated during wound healing and has important effects on keratinocyte migration, invasion and eventually tissue remodeling (D’Alessio, 2008).
Laminin 332 is highly expressed in the catagen phase by keratinocytes in the basement membrane zone of hair follicles. It antagonizes laminin 511 driven hair growth in vitro of human hair follicles and, thus, hair growth has been suggested to be controlled by the relative expression of laminin 511 and laminin 332 (Conti, 2003; Sugawara, 2007; Li, 2003).
Structural changes in the RPE basement/Bruch’s membrane (BrM) lead to alterations in the RPE-matrix adhesion which is commonly the cause for retinal diseases (Zarbin, 2004).
Laminins are produced by and secreted from RPE cells themselves into the RPE basement membrane (Campochiaro, 1986). In particular, the RPE cells produce and bind the strongest to laminin 332 and in vitro, laminin 332 preserves phenotypic stability of mature RPE cells the best (Aisenbrey, 2006).
