Lithium chloride stimulates PLP and MBP expression in oligodendrocytes via Wnt/β-catenin and Akt/CREB pathways

- LiCl induces central myelin gene expression by enhancing PLP and MBP promoter activities.
- Wnt/β-catenin and Akt/CREB pathways are differentially involved in LiCl effect on MBP and PLP expression.
- LiCl improves branching processes and oligodendroglial cell maturation.
- LiCl promotes remyelination after lysocecithin-induced demyelination of organotypic slices of the cerebellum.

Deciphering the molecular pathways involved in myelin gene expression is a major point of interest to better understand re/myelination processes. In this study, we investigated the role of Lithium Chloride (LiCl), a drug largely used for the treatment of neurological disorders, on the two major central myelin gene expression (PLP and MBP) in mouse oligodendrocytes. We show that LiCl enhances the expression of both PLP and MBP, by increasing mRNA amount and promoter activities. We investigated whether Wnt/β-catenin and/or Akt/CREB pathways are modulated by LiCl to regulate myelin gene expression. We showed that β -catenin is required both for PLP and MBP basal promoter activities and for LiCl-induced myelin gene stimulation. Furthermore, while CREB functionality does not influence PLP expression, MBP promoter activity depends on Akt/CREB activation. Finally, we show that LiCl can stimulate oligodendrocyte morphological maturation, and promote remyelination after lysolecithin-induced demyelination of organotypic cerebellar slice cultures. Our data provide mechanistic evidences that Akt/CREB together with β-catenin participate in the transcriptional control of PLP and MBP exerted by LiCl. Therefore, the use of LiCl to balance between β-catenin and CREB effectors could be considered as an efficient remyelinating strategy.

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