Microtubule perturbations of neurite extension and nucleokinesis in an iPSC-derived model system

Abstract

Microtubules in neurons can be characterized based on their dynamic behavior (dynamic vs. stable), on their point of origin (centrosomal vs. acentrosomal), on their relative orientation (parallel vs. antiparallel), and a range of other features. Patterns of different microtubule types are essential in neurite extension and neuronal migration. Cellular model systems such as rodent primary cultures and iPSC-derived neurons have provided key insights into how these patterns are created and maintained through the action of microtubule associated proteins (MAPs), motor proteins, and regulatory enzymes. Here we have characterized a recent cellular model based on induced pluripotent stem cells (iPSC)-derived neurons (EBiSC-NEUR1 neurons), in which doxycycline-induced expression of Neurogenin-2 drives consistent trans-differentiation into the neuronal state. We measured the process extension and nucleokinesis of NEUR1 neurons, which are comparable to published data from primary cultures and other iPSC-based models. We challenged NEUR1 neurons with a panel of drugs modifying microtubule physiology. NEUR1 extension and nucleokinesis were significantly perturbed by two microtubule-targeting drugs, namely a taxane (paclitaxel) and a vinca alkaloid (DZ-2384). In contrast, inhibition of microtubule severing (spastazoline) or of deacetylation (trichostatin A) had a limited effect on nucleokinesis only. Our results support the primary importance of microtubule dynamics in neuronal development and demonstrate the power of NEUR1 neurons as a model system.