What is Laminin 521?

Laminin 521 (LN521, LAMB2, LN-11) is a heterotrimeric glycoprotein composed of α5, β2 and γ1 chains, expressed in stem cells and most basement membranes (especially in the nerve sheath, muscle nerve junction and glomerular basement membrane GBM). It is a key matrix protein that supports the growth of stem cells and maintains the stability and performance of the basement membrane.

Laminin 521 can form a huge net-like material environment together with nestin, collagen, fibronectin, glycosaminoglycan, and other extracellular matrix components. It is a key supportor of various tissues such as muscle fiber, epithelium, nerve, capillaries, fat, etc. In addition, the LG1-5 region of Laminin 521 can bind to cell membrane surface integrin α6β1 or α3β1, etc., start the downstream PI3K-Akt signaling pathway, and promote cell proliferation.

Figure 4. Laminin 521 structure [1].

Laminin for Stem Cell Culture

Due to their unique ability for self-renewal and directional differentiation, stem cells can be applied in many fields such as embryonic development research, drug screening modeling, and cell therapy. At the same time, stem cell culture methods continue to be optimized. Laminin 521 is an important matrix adhesion protein, which can recreate a suitable growth environment for primary cells such as stem cells, and is currently one of the most commonly used trophoblast-free culture substrates.

Laminin 521 can maintain the pluripotency of stem cells, promote cell proliferation, support the clonal expansion of pluripotent human stem cells and the growth of skin keratinocytes. It is also involved in the regulation of important physiological processes such as cell adhesion, migration, differentiation, phenotype maintenance, and matrix-mediated signal transduction [3]. Compared with Laminin 511, Laminin 521 can support the monolayer maintenance and expansion of stem cells in the absence of apoptosis inhibitors (such as ROCK inhibitors). It can be an excellent alternative to Laminin 511 and to some extent, is more suitable for human pluripotency stem cell culture than Laminin 511.