Forskolin and IBMX Induce Neural Transdifferentiation of MSCs Through Downregulation of the NRSF

Ryan Thompson,Christina Chan,Christina Casali

doi:10.1038/s41598-019-39544-0

Ryan Thompson, Christina Chan + Show 1 more

Open Access

https://doi.org/10.1038/s41598-019-39544-0

Copy DOI

Journal: Scientific Reports	Publication Date: Feb 27, 2019
Citations: 25	License type: open-access

Affiliation: Michigan State University

Abstract

Neural differentiation of mesenchymal stem cells is a controversial phenomenon, as it would require transdifferentiation across the mesoderm-ectoderm barrier. However, several laboratories have observed that MSCs are able to be induced to express neural characteristics. Previously, we demonstrated that the cAMP-elevating agents, forskolin and IBMX, induced neural-like differentiation of MSCs, including expression of neural markers and increased sensitivity to neurotransmitters. However, due to the broad range of effects that forskolin and IBMX can elicit through the intracellular second messenger, cAMP, a better mechanistic understanding is required. Here, we show that neural induction by forskolin and IBMX is dependent on downregulation of expression of the master transcriptional regulator, neuron restrictive silencer factor (NRSF), and its downstream target genes. Since silencing of NRSF is known to initiate neural differentiation, it suggests that forskolin and IBMX result in transdifferentiation of MSCs into a neural lineage.

Highlights

Neural differentiation of MSCs remains a controversial topic because it requires transdifferentiation across the mesoderm-ectoderm germline barrier
We found that inducing neural differentiation in MSCs with forskolin and IBMX (FI) strongly downregulated neuron restrictive silencer factor (NRSF) protein expression after 24 h, which continued over the 5 day treatment course (Fig. 1A)
Due to the highly pleiotropic nature of CREB and its importance to other non-neural cell lineages, we investigated possible mechanisms induced by FI that might be specific to neural differentiation

Summary

Introduction

Neural differentiation of MSCs remains a controversial topic because it requires transdifferentiation across the mesoderm-ectoderm germline barrier. A better characterization of the mechanism is needed to explain the neural-inducing effect of FI within the mesodermal background of MSCs. Transcription factors are critical for specifying cell lineage. Yang et al demonstrated that knockdown of the master transcriptional repressor of the neural phenotype, the neuron restrictive silencer factor (NRSF), induces neural gene expression, gain of neuronal morphology, and causes the cells to generate spontaneous action potentials[26]. We report that FI downregulates expression of NRSF and that this event is responsible for the expression of neuronal genes and for the increase in sensitivity to neurotransmitters in MSCs. Knockdown of NRSF recapitulates the changes observed during FI induced differentiation and overexpression of NRSF is able to block expression of neuronal genes in FI-treated MSCs. We propose that the mechanism behind FI induced neural transdifferentiation of MSCs requires the downregulation of NRSF

Methods

Results

Conclusion