Convergent genomic and pharmacological evidence of PI3K/GSK3 signaling alterations in neurons from schizophrenia patients

Ying Liu,Jessica Di Re,Rohan Cherukuru,Peilin Jia,Laura Smith-Callahan,Shenglan Li,Henriette Raventos,Guangsheng Pei,Laura Stertz,Zhongming Zhao,Fernanda Laezza,Consuelo Walss-Bass,Gabriel R Fries,Jerricho Tipo,Emily Mendez

doi:10.1038/s41386-020-00924-0

Abstract

Human-induced pluripotent stem cells (hiPSCs) allow for the establishment of brain cellular models of psychiatric disorders that account for a patient’s genetic background. Here, we conducted an RNA-sequencing profiling study of hiPSC-derived cell lines from schizophrenia (SCZ) subjects, most of which are from a multiplex family, from the population isolate of the Central Valley of Costa Rica. hiPSCs, neural precursor cells, and cortical neurons derived from six healthy controls and seven SCZ subjects were generated using standard methodology. Transcriptome from these cells was obtained using Illumina HiSeq 2500, and differential expression analyses were performed using DESeq2 (|fold change|>1.5 and false discovery rate < 0.3), in patients compared to controls. We identified 454 differentially expressed genes in hiPSC-derived neurons, enriched in pathways including phosphoinositide 3-kinase/glycogen synthase kinase 3 (PI3K/GSK3) signaling, with serum-glucocorticoid kinase 1 (SGK1), an inhibitor of glycogen synthase kinase 3β, as part of this pathway. We further found that pharmacological inhibition of downstream effectors of the PI3K/GSK3 pathway, SGK1 and GSK3, induced alterations in levels of neurite markers βIII tubulin and fibroblast growth factor 12, with differential effects in patients compared to controls. While demonstrating the utility of hiPSCs derived from multiplex families to identify significant cell-specific gene network alterations in SCZ, these studies support a role for disruption of PI3K/GSK3 signaling as a risk factor for SCZ.

Highlights

Human-induced pluripotent stem cell technology, and further differentiation into specific brain cell types, is an emerging approach to study cellular models of schizophrenia (SCZ) and other psychiatric disorders
As the aneuploidy is found in equal number of patients and controls in a very small percentage of cells, we do not expect this to influence the study. Human-induced pluripotent stem cells (hiPSCs) characterization and differentiation to hiPSC–neuronal precursor cells (NPCs) and hiPSC–neurons were performed for each subject (Fig. 1 and Supplementary Fig. S1)
No differences were found between healthy controls (HC) and SCZ cell lines on the expression of NPC and neuronal markers

Summary

Introduction

Human-induced pluripotent stem cell (hiPSC) technology, and further differentiation into specific brain cell types, is an emerging approach to study cellular models of schizophrenia (SCZ) and other psychiatric disorders. A transcriptome study utilizing neurons derived from a childhood-onset SCZ cohort identified overlap of neuronal transcriptional signatures with postmortem adult brains but failed to identify definitive differentially expressed genes (DEGs) [4]. Studies of cell lines derived from families with multiple affected individuals, in particular families from genetically homogeneous populations, may provide an important strategy to overcome the dilution of genetic effects typical of case-control studies, as persons with genetic diseases in these populations are more likely to share the same genetic mutations, and molecular and cellular profiles, than persons from genetically diverse populations, facilitating identification of causative gene networks [5]. We hypothesized that generation of hiPSCs from subjects carrying common genetic alterations would empower the identification of global transcriptome alterations and gene network pathways in a cell-type- and disease-specific way

Methods

Results

Conclusion