Selective TGF-β1/ALK inhibitor improves neuronal differentiation of mouse embryonic stem cells

• Inhibition of TGF-β1/ALK pathway efficiently decrease contamination of pluripotent cells in ESC-derived neuronal population.
• TGF-β1/ALK inhibitor rapidly drives cell fate alteration from pluripotent state toward neuronal lineages.
• TGF-β1/ALK inhibitor significantly suppresses gliogenesis within EBs during neuronal differentiation.

The transforming growth factor-β1 (TGF-β1), a polypeptide member of the TGF-β superfamily, has myriad cellular functions, including cell fate differentiation. We hypothesized that suppression of TGF-β1 signaling would improve the efficacy of neuronal differentiation during embryoid body (EB) development. In this study, mouse embryonic stem cells (ESCs) were allowed to differentiate into their neuronal lineage, both with, and without the TGF-β1 inhibitor (A83-01). After 8 days of EB suspension culture, the samples were examined by morphological analysis, immunocytochemistry and immunohistochemistry with pluripotent (Oct4, Sox2) and neuronal specific markers (Pax6, NeuN). The alteration of gene expressions during EB development was determined by quantitative RT-PCR. Our results revealed that the TGF-β1/ALK inhibitor potentially suppressed pluripotent gene (Oct4) during a rapidly up-regulation of neuronal associated genes including Sox1 and MAP2. Strikingly, during EB development, the expression of GFAP, the astrocyte specific gene, remarkably decreased compared to the non-treated control. This strategy demonstrated the beneficial function of TGF-β1/ALK inhibitor that rapidly and uniformly drives cell fate alteration from pluripotent state toward neuronal lineages.