A role for TGFβ signalling in medium spiny neuron differentiation of human pluripotent stem cells.

Marija Fjodorova,Meng Li,Zoe Noakes

doi:10.1042/ns20200004

Abstract

Activin A and other TGFβ family members have been shown to exhibit a certain degree of promiscuity between their family of receptors. We previously developed an efficient differentiation protocol using Activin A to obtain medium spiny neurons (MSNs) from human pluripotent stem cells (hPSCs). However, the mechanism underlying Activin A-induced MSN fate specification remains largely unknown. Here we begin to tease apart the different components of TGFβ pathways involved in MSN differentiation and demonstrate that Activin A acts exclusively via ALK4/5 receptors to induce MSN progenitor fate during differentiation. Moreover, we show that Alantolactone, an indirect activator of SMAD2/3 signalling, offers an alternative approach to differentiate hPSC-derived forebrain progenitors into MSNs. Further fine tuning of TGFβ pathway by inhibiting BMP signalling with LDN193189 achieves accelerated MSN fate specification. The present study therefore establishes an essential role for TGFβ signalling in human MSN differentiation and provides a fully defined and highly adaptable small molecule-based protocol to obtain MSNs from hPSCs.

Highlights

Medium spiny neurons (MSNs) are the principal projection neurons of the striatum that receive synaptic inputs from both glutamatergic and dopaminergic afferents as part of the basal ganglia circuit
• We previously developed an efficient differentiation protocol using Activin A to obtain medium spiny neurons (MSNs) from human pluripotent stem cells (hPSCs)
We show that Alantolactone, an indirect activator of SMAD2/3 signalling, offers an alternative approach to differentiate hPSC-derived forebrain progenitors into MSNs

Summary

Introduction

Medium spiny neurons (MSNs) are the principal projection neurons of the striatum that receive synaptic inputs from both glutamatergic and dopaminergic afferents as part of the basal ganglia circuit. Previous works towards differentiating hPSCs into MSNs have focused on ventralising anterior neural progenitors produced from stromal cell co-culture, embryoid body or monolayer neural induction [6,7,8,9]. These groups acted on the principle that FOXG1+ cells in the developing telencephalon are exposed to opposing gradients of the ventralizing morphogen SHH and its repressor GLI3, which is expressed in dorsal tissues together with BMP and Wnt proteins [10]. It is likely that the MSNs generated using SHH and License 4.0 (CC BY)

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