ZEB2 haploinsufficient Mowat-Wilson syndrome induced pluripotent stem cells show disrupted GABAergic transcriptional regulation and function

Jens Schuster; Joakim Klar; Ayda Khalfallah; Loora Laan; Jan Hoeber; Ambrin Fatima; Velin Marita Sequeira; Zhe Jin; Sergiy V Korol; Mikael Huss; Ann Nordgren; Britt Marie Anderlid; Caroline Gallant; Bryndis Birnir; Niklas Dahl

doi:10.3389/fnmol.2022.988993

ZEB2 haploinsufficient Mowat-Wilson syndrome induced pluripotent stem cells show disrupted GABAergic transcriptional regulation and function

Front Mol Neurosci. 2022 Oct 24:15:988993. doi: 10.3389/fnmol.2022.988993. eCollection 2022.

Authors

Jens Schuster¹, Joakim Klar¹, Ayda Khalfallah¹, Loora Laan¹, Jan Hoeber¹, Ambrin Fatima¹, Velin Marita Sequeira¹, Zhe Jin², Sergiy V Korol², Mikael Huss³, Ann Nordgren^{4

5}, Britt Marie Anderlid^{4

5}, Caroline Gallant¹, Bryndis Birnir², Niklas Dahl¹

Affiliations

¹ Department of Immunology, Genetics and Pathology, Uppsala University and Science for Life Laboratory, Uppsala, Sweden.
² Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
³ Wallenberg Long-Term Bioinformatics Support, Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
⁴ Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
⁵ Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.

Abstract

Mowat-Wilson syndrome (MWS) is a severe neurodevelopmental disorder caused by heterozygous variants in the gene encoding transcription factor ZEB2. Affected individuals present with structural brain abnormalities, speech delay and epilepsy. In mice, conditional loss of Zeb2 causes hippocampal degeneration, altered migration and differentiation of GABAergic interneurons, a heterogeneous population of mainly inhibitory neurons of importance for maintaining normal excitability. To get insights into GABAergic development and function in MWS we investigated ZEB2 haploinsufficient induced pluripotent stem cells (iPSC) of MWS subjects together with iPSC of healthy donors. Analysis of RNA-sequencing data at two time points of GABAergic development revealed an attenuated interneuronal identity in MWS subject derived iPSC with enrichment of differentially expressed genes required for transcriptional regulation, cell fate transition and forebrain patterning. The ZEB2 haploinsufficient neural stem cells (NSCs) showed downregulation of genes required for ventral telencephalon specification, such as FOXG1, accompanied by an impaired migratory capacity. Further differentiation into GABAergic interneuronal cells uncovered upregulation of transcription factors promoting pallial and excitatory neurons whereas cortical markers were downregulated. The differentially expressed genes formed a neural protein-protein network with extensive connections to well-established epilepsy genes. Analysis of electrophysiological properties in ZEB2 haploinsufficient GABAergic cells revealed overt perturbations manifested as impaired firing of repeated action potentials. Our iPSC model of ZEB2 haploinsufficient GABAergic development thus uncovers a dysregulated gene network leading to immature interneurons with mixed identity and altered electrophysiological properties, suggesting mechanisms contributing to the neuropathogenesis and seizures in MWS.

Keywords: FOXG1; GABAergic interneurons; Mowat-Wilson syndrome; ZEB2; electrophysiology; epilepsy; neurodevelopmental disease; transcriptional network.