Pretreatment with Perlecan-Conjugated Laminin-E8 Fragment Enhances Maturation of Grafted Dopaminergic Progenitors in Parkinson's Disease Model.

The therapeutic effect of a cell replacement therapy for Parkinson's disease (PD) depends on the proper maturation of grafted dopaminergic (DA) neurons and their functional innervation in the host brain. In the brain, laminin, an extracellular matrix protein, regulates signaling pathways for the survival and development of neurons by interacting with integrins. The heparan sulfate (HS) chain binds mildly to various neurotrophic factors and regulates their intracellular signaling. Perlecan-conjugated laminin 511/521-E8 fragments (p511/p521) were designed to contain an integrin-binding site and HS chains. Here we examined the effect of treating DA progenitors with p511/p521 prior to transplantation in rodent PD models. In vitro and in vivo experiments showed that p511/p521 treatment enhanced the maturation and neurite extension of the grafted DA progenitors by activating RAS-ERK1/2 signaling. This strategy will contribute to an efficient cell replacement therapy for PD in the future.