2026 ECNP Congress

PS04-4057

Modeling CDH13-dependent network dysfunction in human cortical cultures: From gene variants to circuit phenotypes

Dorothea Lambrini Tsounis — E. Kutluyuva, L. Dürner, R. Riemens, D. van den Hove, K.P. Lesch · Division of Molecular Psychiatry, Department of Child and Adolescent Psychiatry- Psychosomatics and Psychotherapy - Center of Mental Health- University Hospital Würzburg, Würzburg, Germany

2026 ECNP Congress

Introduction

Cadherin-13 (CDH13) is an atypical, glycosylphosphatidylinositol-anchored cadherin highly expressed in GABAergic interneurons, where it regulates inhibitory synapse organization and stability. Genetic variants in CDH13 have been consistently associated with attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD) [1]. The rs2199430 locus, located in the CDH13 gene, has been specifically associated with low agreeableness and altered neural responses in ADHD patients [2]. CDH13 functions as a negative regulator of inhibitory control, and its impairment is hypothesized to disrupt excitatory-inhibitory (E/I) balance in cortical networks [3]. Yet, the cellular mechanisms by which CDH13 variants contribute to neurodevelopmental disorder phenotypes remain poorly understood.

Methods

To investigate CDH13-associated network-level mechanisms, we are generating human induced pluripotent stem cell (hiPSC)-derived cortical neuronal co-cultures using previously established cell lines, including CRISPR/Cas9-generated heterozygous (HET) and null knockout (KO) lines from a healthy donor (wildtype, WT; rs2199430 GG) [4], and patient-derived lines carrying CDH13 polymorphisms at the rs2199430 locus (AG and AA genotypes). Neuronal differentiation is achieved through lentiviral transduction of Neurogenin-2 (NGN2) and Achaete-scute homolog 1 (ASCL1) transcription factors, producing mixed excitatory-inhibitory cortical cultures over 50 days in vitro. Multiple clones per cell line were validated for transgene expression using RT-qPCR, and the best-performing clones were selected for downstream experiments. The experimental design incorporates systematic biological replication across three independent differentiation rounds per genotype to capture intrinsic variability in network development. Planned analyses include calcium imaging and multi-electrode array (MEA) electrophysiology to assess neuronal excitability and network dynamics, immunofluorescence to quantify inhibitory and excitatory synaptic markers, gene expression profiling via RT-qPCR and RNA sequencing, and metabolomic profiling to identify CDH13-dependent alterations in cellular signaling pathways.

Results

Initial validation experiments confirm successful lentiviral transduction and stable transgene expression across all CDH13 genotypes. Clone selection based on NGN2/ASCL1 expression levels has been completed for WT, HET, and KO lines, as well as patient-derived AG and AA lines. Differentiation protocols yield functional neuronal networks with appropriate temporal maturation profiles. Calcium imaging data collection is currently in progress, and preliminary analysis of spontaneous Ca²⁺ activity at DIV50 reveals functional neuronal networks with detectable activity across all genotypes. Ongoing analyses are examining per-cell activity metrics, recruitment of neurons into active network states, and network-level properties including synchrony, burst dynamics, and functional connectivity to characterize potential genotype-dependent differences in circuit organization. Sample collections for RNA extractions and metabolomic analyses are ongoing and expected to be completed by July 2026.

Conclusions

This hiPSC-based approach provides a controlled genetic model to investigate how CDH13 variants alter cortical E/I balance and network dynamics at the cellular level. Ongoing functional analyses will characterize CDH13-dependent phenotypes in excitability, synaptic organization, network synchrony, and metabolic signaling. By linking genetic risk variants to circuit-level mechanisms, this work aims to elucidate the cellular basis of CDH13-associated neurodevelopmental and psychiatric disorders, potentially informing more targeted therapeutic strategies.

References

  1. Z. Hawi, J. Tong, C. Dark, H. Yates, B. Johnson, and M. A. Bellgrove, ‘The role of cadherin genes in five major psychiatric disorders: A literature update’, Am. J. Med. Genet. B Neuropsychiatr. Genet., vol. 177, no. 2, pp. 168–180, 2018, doi: 10.1002/ajmg.b.32592.
  2. G. C. Ziegler et al., ‘A Common CDH13 Variant Is Associated with Low Agreeableness and Neural Responses to Working Memory Tasks in ADHD’, Genes, vol. 12, no. 9, p. 1356, Aug. 2021, doi: 10.3390/genes12091356.
  3. B. Mossink et al., ‘Cadherin-13 is a critical regulator of GABAergic modulation in human stem-cell-derived neuronal networks’, Mol. Psychiatry, vol. 27, no. 1, pp. 1–18, Jan. 2022, doi: 10.1038/s41380-021-01117-x.
  4. M. R. Vitale et al., ‘Generation of induced pluripotent stem cell (iPSC) lines carrying a heterozygous (UKWMPi002-A-1) and null mutant knockout (UKWMPi002-A-2) of Cadherin 13 associated with neurodevelopmental disorders using CRISPR/Cas9’, Stem Cell Res., vol. 51, p. 102169, Mar. 2021, doi: 10.1016/j.scr.2021.102169.