Myelin Formation by Oligodendrocytes Is Enhanced Through Laminin-411 and Its Derived Peptide.

In the central nervous system, oligodendrocytes (OLs) form myelin sheaths that accomplish the efficient transmission of nerve conduction for optimal motor and cognitive functions. OL development and differentiation are regulated by a variety of molecules, including extracellular matrix (ECM) proteins. ECM proteins are also useful as substrates for OL culture. However, the functions of ECM proteins in OL development and myelination remain unclear, and only a limited number of ECM proteins have been characterized and used in in vitro experiments. Here, we investigated the expression and function of laminin (LM) isoforms in OL differentiation and myelination. We found that LM α1, α2, and α4 chains were expressed around blood vessels at the stage of myelination in mice. Functional analyses using recombinant proteins of LM isoforms containing α1, α2, and α4 chains revealed that LM411 and LM411E8, the integrin binding domain of LM411, possessed significant activities in myelin membrane formation of OLs. Furthermore, the peptide A4G47 derived from LM411E8 promoted the activity, which provides evidence of the first peptide in OL myelin formation from ECM proteins. Our findings facilitate a better understanding of ECM functions in OL biology and the development of a new material in OL myelination.