Laminins are one of the major protein groups in the extracellular matrix (ECM) and
specific laminin isoforms are crucial for neuronal functions in the central nervous
system in vivo. In the present study, we compared recombinant human laminin isoforms
(LN211, LN332, LN411, LN511, and LN521) and laminin isoform fragment (LN511-E8) in
in vitro cultures of human pluripotent stem cell (hPSC)-derived neurons. We showed
that laminin substrates containing the α5-chain are important for neuronal attachment,
viability and network formation, as detected by phase contrast imaging, viability
staining, and immunocytochemistry. Gene expression analysis showed that the molecular
mechanisms involved in the preference of hPSC-derived neurons for specific laminin
isoforms could be related to ECM remodeling and cell adhesion. Importantly, the microelectrode
array analysis revealed the widest distribution of electrophysiologically active neurons
on laminin α5 substrates, indicating most efficient development of neuronal network
functionality. This study shows that specific laminin α5 substrates provide a controlled
in vitro culture environment for hPSC-derived neurons. These substrates can be utilized
not only to enhance the production of functional hPSC-derived neurons for in vitro
applications like disease modeling, toxicological studies, and drug discovery, but
also for the production of clinical grade hPSC-derived cells for regenerative medicine
applications.