P53 controls genomic stability and temporal differentiation of human neural stem cells and affects neural organization in human brain organoids

Robin Johan Pronk,Astrid Tjitske van der Geest,Ana Marin Navarro,Anna Falk,Ann Nordgren,Margareta Wilhelm,Marie Arsenian-Henriksson,Ganna Oliynyk

doi:10.1038/s41419-019-2208-7

Robin Johan Pronk, Astrid Tjitske van der Geest + Show 6 more

Open Access

https://doi.org/10.1038/s41419-019-2208-7

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Abstract

In this study, we take advantage of human induced pluripotent stem (iPS) cell-derived neural stem cells and brain organoids to study the role of p53 during human brain development. We knocked down (KD) p53 in human neuroepithelial stem (NES) cells derived from iPS cells. Upon p53KD, NES cells rapidly show centrosome amplification and genomic instability. Furthermore, a reduced proliferation rate, downregulation of genes involved in oxidative phosphorylation (OXPHOS), and an upregulation of glycolytic capacity was apparent upon loss of p53. In addition, p53KD neural stem cells display an increased pace of differentiating into neurons and exhibit a phenotype corresponding to more mature neurons compared to control neurons. Using brain organoids, we modeled more specifically cortical neurogenesis. Here we found that p53 loss resulted in brain organoids with disorganized stem cell layer and reduced cortical progenitor cells and neurons. Similar to NES cells, neural progenitors isolated from brain organoids also show a downregulation in several OXPHOS genes. Taken together, this demonstrates an important role for p53 in controlling genomic stability of neural stem cells and regulation of neuronal differentiation, as well as maintaining structural organization and proper metabolic gene profile of neural progenitors in human brain organoids.

Highlights

TP53 is a tumor-suppressor gene that is mutated or inactivated in >50% of all human cancers[1]
Loss of p53 impairs neural stem cell division and promotes genomic instability To address the role of p53 in human neural development, we knocked down p53 using shRNA in two different neuroepithelial stem (NES) cell lines, NES1 (AF22) and NES2 (C9), that we have derived from induced pluripotent stem (iPS) cells generated from two different healthy individuals[13,26]
NES cells grow in a characteristic rosette-like organization and express neural stem cell markers NESTIN, SOX2, PLZF, and ZO-113,14,27,28 that were still present after p53 knocked down (KD) (Fig. 1d, Supplementary Fig. 1e) showing that p53KD NES cells maintain markers of stemness specific for neural stem cells

Summary

Introduction

TP53 is a tumor-suppressor gene that is mutated or inactivated in >50% of all human cancers[1]. Activation of p53 induces multiple cellular processes, such as cell cycle arrest, apoptosis, and differentiation[3]. While p53 mainly has been studied for tumor-suppressor functions, its role during human brain development is less understood. P53 is ubiquitously expressed throughout the whole mouse brain during early embryogenesis[4,5], p53 knock out (KO) mice were found to be developmentally normal, albeit succumbing to early onset of tumor formation[6]. Maintaining correct p53 protein levels in the central nervous system (CNS) is imperative to avoid inducing aberrant apoptosis or cell cycle arrest[9,10]. The role of p53 in CNS development has mostly been studied in murine models and little is known about the biological role of p53

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