PPAR Agonists and 3D Alginate Encapsulation Accelerate Oligodendrocyte Differentiation of Mouse Embryonic Stem Cells

Abstract

Cellular replacement therapies for myelin disorders require large numbers of cells and relatively mature oligodendrocytes. Oligodendrocyte differentiation from a pluripotent state often involves long protracted protocols. In this study, we investigated the effect that activation of peroxisome proliferator activator receptors (PPAR) alpha, delta and gamma would have on oligodendrocyte differentiation of mouse embryonic stem (mES) cells. Using a two-dimensional (2D) differentiation platform, oligodendrocyte differentiation stalled at the immature oligodendrocyte stage, i.e., CNPase positive cells. When PPAR agonists for alpha, delta and gamma were added, oligodendrocyte differentiation was accelerated with higher numbers of O1 and CNPase positive cells being detected. PPAR agonist addition also resulted in phenotypic changes with alpha agonist addition resulting in an increase in process length compared to control with some increased secondary branching, delta agonist addition resulted in longer primary process length, and gamma agonist addition resulted in a larger cell soma and more tertiary branching patterns. Placing mES cells into a three-dimensional (3D) alginate nanoporous microcapsule environment, we were able to further mature cells to a myelin basic protein (MBP) expressing stage. The exposure of cells to PPAR agonists within the alginate microcapsules resulted in accelerated maturation with PPAR delta in particular showing a sustained high expression of MBP. The combined effect of PPAR activation in a 3D environment demonstrates a relatively simple and efficient method to differentiate mES cells into mature oligodendrocytes.