Synaptic deficits in iPSC-derived cortical interneurons in schizophrenia are mediated by NLGN2 and rescued by N-acetylcysteine

Abstract

Human postmortem studies suggest a major role for abnormalities in GABAergic interneurons in the prefrontal cortex in schizophrenia. Cortical interneurons differentiated from induced pluripotent stem cells (iPSCs) of schizophrenia subjects showed significantly lower levels of glutamate decarboxylase 67 (GAD67), replicating findings from multiple postmortem studies, as well as reduced levels of synaptic proteins gehpyrin and NLGN2. Co-cultures of the interneurons with excitatory cortical pyramidal neurons from schizophrenia iPSCs showed reduced synaptic puncta density and lower action potential frequency. NLGN2 overexpression in schizophrenia neurons rescued synaptic puncta deficits while NLGN2 knockdown in healthy neurons resulted in reduced synaptic puncta density. Schizophrenia interneurons also had significantly smaller nuclear area, suggesting an innate oxidative stressed state. The antioxidant N-acetylcysteine increased the nuclear area in schizophrenia interneurons, increased NLGN2 expression and rescued synaptic deficits. These results implicate specific deficiencies in the synaptic machinery in cortical interneurons as critical regulators of synaptic connections in schizophrenia and point to a nexus between oxidative stress and NLGN2 expression in mediating synaptic deficits in schizophrenia.

Developmental excitation-inhibition imbalance underlying psychoses revealed by single-cell analyses of discordant twins-derived cerebral organoids

“…Previous studies analyzing iPSC-derived neurons from the patients with SZ have suggested the alterations in synaptic function such as attenuation of neuronal connectivity [ 48 ], reduced neuronal activity [ 49 – 51 ], deficit in synaptic density [ 48 , 49 , 51 – 53 ], and neurotransmitter release [ 49 , 52 , 54 ]. However, these findings relied on the analyses of spontaneous synaptic events and morphology.…”

Transcriptome analysis and functional characterization of cerebral organoids in bipolar disorder

“…The study of neuropsychiatric disorders such as BPI has historically been hindered by the lack of access to the disease-relevant tissue from patients, but recent advances in the ability to generate iPSCs from somatic cells provide new avenues to study disease biology using stem cell-based ex vivo cellular models [67]. iPSCs can be readily differentiated to a wide variety of neuronal and glial cell types, enabling the study of cell types that are relevant to disease biology [26,[68][69][70][71][72][73]. While the use of iPSC-based cellular models to study the neurobiology of BPI has been limited to the use of two-dimensional neuronal cultures, methods to grow brain organoids provide ways to study the disease biology in complex threedimensional structures that comprise a large number of cell types [74,75].…”

“…Demographic characteristics of the eight BPI patients and eight healthy control individuals are presented in Additional file 1: Table S1. The fibroblasts were reprogrammed into iPSCs through induction using modified mRNA or with transient transfection with retroviruses using methods described before and validated using standard protocols [24][25][26] (Additional file 1: Figure S3, Additional file 1: Table S1, Additional files 2 and 3). These iPSCs were differentiated to generate cerebral organoids patterned after the dorsal forebrain [27].…”

“…Differentiation of iPSCs to excitatory cortical neurons iPSCs were cultured on Geltrex (ThermoFisher Scientific, A1413202) in NutriStem hPSC XF Medium (Biological Industries, 01-0005). Confluent iPSC cultures were differentiated into cortical excitatory neurons using standard protocols [26,28]. The culture media were replenished daily for 7 days using culture media made with 50% N2 medium comprising 485 mL neurobasal medium (Life Technologies, 21103049), 5 mL N-2 supplement (Gibco, 17502001), 5 mL Glutamax (ThermoFisher Scientific, 35050061), and 5 mL penicillin-streptomycin (Gibco 15140122), and 50% B-27 medium comprising 10 mL B-27 supplement (Gibco, 17504044), 480 mL Dulbecco's modified Eagle medium (DMEM) medium (Sigma-Aldrich, D6421), 5 mL Glutamax (ThermoFisher Scientific, 35050061), and 5 mL penicillin-streptomycin (Gibco 15140122) supplemented with 10 μM SB431542 (Sigma-Aldrich, S4317), 1 μM dorsomorphin (Sigma-Aldrich, P5499), and 100 nM LDN193189 (Sigma-Aldrich, SML0599).…”

The Role of Brain Microvascular Endothelial Cell and Blood-Brain Barrier Dysfunction in Schizophrenia

“…Human induced pluripotent stem cells (iPSC) provide us with the opportunity to develop physiologically relevant models of psychiatric disorders such as schizophrenia and bipolar disorder [28][29][30]. The use of iPSC-derived models to investigate schizophrenia pathophysiology has revealed disease-related changes in gene expression as well as deficits in specific neuronal subtypes [31,32]. Recent technical advances that enable efficient differentiation of iPSC to BMEC provide an opportunity to culture and study BMEC with disease-specific genetic backgrounds.…”