Multiple alterations in glutamatergic transmission and dopamine D2 receptor splicing in induced pluripotent stem cell-derived neurons from patients with familial schizophrenia

AbstractAn increasing body of evidence suggests that impaired synapse development and function are associated with schizophrenia; however, the underlying molecular pathophysiological mechanism of the disease remains largely unclear. We conducted a family-based study combined with molecular and cellular analysis using induced pluripotent stem cell (iPSC) technology. We generated iPSCs from patients with familial schizophrenia, differentiated these cells into neurons, and investigated the molecular and cellular phenotypes of the patient’s neurons. We identified multiple altered synaptic functions, including increased glutamatergic synaptic transmission, higher synaptic density, and altered splicing of dopamine D2 receptor mRNA in iPSC-derived neurons from patients. We also identified patients’ specific genetic mutations using whole-exome sequencing. Our findings support the notion that altered synaptic function may underlie the molecular and cellular pathophysiology of schizophrenia, and that multiple genetic factors cooperatively contribute to the development of schizophrenia.

Download Full-text

Investigation of de novo mutations in a schizophrenia case-parent trio by induced pluripotent stem cell-based in vitro disease modeling: convergence of schizophrenia- and autism-related cellular phenotypes

Stem Cell Research & Therapy ◽

10.1186/s13287-020-01980-5 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Edit Hathy ◽

Eszter Szabó ◽

Nóra Varga ◽

Zsuzsa Erdei ◽

Csongor Tordai ◽

...

Keyword(s):

Stem Cell ◽

Dentate Gyrus ◽

Pluripotent Stem Cell ◽

Disease Modeling ◽

De Novo ◽

Disease Onset ◽

Induced Pluripotent Stem Cell ◽

Synaptic Function ◽

De Novo Mutations ◽

Induced Pluripotent

Abstract Background De novo mutations (DNMs) have been implicated in the etiology of schizophrenia (SZ), a chronic debilitating psychiatric disorder characterized by hallucinations, delusions, cognitive dysfunction, and decreased community functioning. Several DNMs have been identified by examining SZ cases and their unaffected parents; however, in most cases, the biological significance of these mutations remains elusive. To overcome this limitation, we have developed an approach of using induced pluripotent stem cell (iPSC) lines from each member of a SZ case-parent trio, in order to investigate the effects of DNMs in cellular progenies of interest, particularly in dentate gyrus neuronal progenitors. Methods We identified a male SZ patient characterized by early disease onset and negative symptoms, who is a carrier of 3 non-synonymous DNMs in genes LRRC7, KHSRP, and KIR2DL1. iPSC lines were generated from his and his parents’ peripheral blood mononuclear cells using Sendai virus-based reprogramming and differentiated into neuronal progenitor cells (NPCs) and hippocampal dentate gyrus granule cells. We used RNASeq to explore transcriptomic differences and calcium (Ca2+) imaging, cell proliferation, migration, oxidative stress, and mitochondrial assays to characterize the investigated NPC lines. Results NPCs derived from the SZ patient exhibited transcriptomic differences related to Wnt signaling, neuronal differentiation, axonal guidance and synaptic function, and decreased Ca2+ reactivity to glutamate. Moreover, we could observe increased cellular proliferation and alterations in mitochondrial quantity and morphology. Conclusions The approach of reprograming case-parent trios represents an opportunity for investigating the molecular effects of disease-causing mutations and comparing these in cell lines with reduced variation in genetic background. Our results are indicative of a partial overlap between schizophrenia and autism-related phenotypes in the investigated family. Limitations Our study investigated only one family; therefore, the generalizability of findings is limited. We could not derive iPSCs from two other siblings to test for possible genetic effects in the family that are not driven by DNMs. The transcriptomic and functional assays were limited to the NPC stage, although these variables should also be investigated at the mature neuronal stage.

Download Full-text

Investigation of de novo mutations in a schizophrenia case-parent trio by induced pluripotent stem cell based in vitro disease-modeling: Convergence of schizophrenia and autism-related cellular phenotypes

10.21203/rs.3.rs-83185/v1 ◽

2020 ◽

Author(s):

Edit Hathy ◽

Eszter Szabó ◽

Nóra Varga ◽

Zsuzsa Erdei ◽

Csongor Tordai ◽

...

Keyword(s):

Stem Cell ◽

Dentate Gyrus ◽

Pluripotent Stem Cell ◽

Disease Modeling ◽

De Novo ◽

Disease Onset ◽

Induced Pluripotent Stem Cell ◽

Synaptic Function ◽

De Novo Mutations ◽

Induced Pluripotent

Abstract Background: De novo mutations (DNMs) have been implicated in the etiology of schizophrenia (SZ), a chronic debilitating psychiatric disorder characterized by hallucinations, delusions, cognitive dysfunction and decreased community functioning. Several DNMs have been identified by examining SZ cases and their unaffected parents, however in most cases the biological significance of these mutations remains elusive. To overcome this limitation, we have developed an approach of using induced pluripotent stem cell (iPSC) lines from each member of a SZ case-parent trio, in order to investigate the effects of DNMs in cellular progenies of interest, particularly in dentate gyrus neuronal progenitors.Methods: We identified a male SZ patient characterized by early disease onset and negative symptoms, who is a carrier of 3 non-synonymous DNMs in genes LRRC7, KHSRP, and KIR2DL1. iPSC lines were generated from his and his parents’ peripheral blood mononuclear cells using Sendai virus-based reprogramming and differentiated into neuronal progenitor cells (NPCs) and hippocampal dentate gyrus granule cells. We used RNASeq to explore transcriptomic differences, and calcium (Ca2+) imaging, cell proliferation, migration, oxidative stress, and mitochondrial assays to characterize the investigated NPC lines. Results: NPCs derived from the SZ patient exhibited transcriptomic differences related to Wnt-signaling, neuronal differentiation, axonal guidance and synaptic function, and decreased Ca2+ reactivity to glutamate. Moreover, we could observe increased cellular proliferation, and alterations in mitochondrial quantity and morphology.Conclusions: The approach of reprograming case-parent trios represents an opportunity for investigating the molecular effects of disease-causing mutations, and comparing these in cell lines with reduced variation in genetic background. Our results are indicative of a partial overlap between schizophrenia and autism-related phenotypes in the investigated family.Limitations: Our study investigated only one family, therefore the generalizability of findings is limited. We could not derive iPSCs from two other siblings to test for possible genetic effects in the family that are not driven by DNMs. The transcriptomic and functional assays were limited to the NPC stage, although these variables should also be investigated at the mature neuronal stage.

Download Full-text

Investigation of de novo mutations in a schizophrenia case-parent trio by induced pluripotent stem cell based in vitro disease-modeling: Convergence of schizophrenia and autism-related cellular phenotypes

10.21203/rs.2.20699/v2 ◽

2020 ◽

Author(s):

Edit Hathy ◽

Eszter Szabó ◽

Nóra Varga ◽

Zsuzsa Erdei ◽

Csongor Tordai ◽

...

Keyword(s):

Stem Cell ◽

Dentate Gyrus ◽

Pluripotent Stem Cell ◽

Disease Modeling ◽

De Novo ◽

Disease Onset ◽

Induced Pluripotent Stem Cell ◽

Synaptic Function ◽

De Novo Mutations ◽

Induced Pluripotent

Abstract Background: De novo mutations (DNMs) have been implicated in the etiology of schizophrenia (SZ), a chronic debilitating psychiatric disorder characterized by hallucinations, delusions, cognitive dysfunction and decreased community functioning. Several DNMs have been identified by examining SZ cases and their unaffected parents, however in most cases the biological significance of these mutations remains elusive. To overcome this limitation, we have developed an approach of using induced pluripotent stem cell (iPSC) lines from each member of a SZ case-parent trio, in order to investigate the effects of DNMs in cellular progenies of interest, particularly in dentate gyrus neuronal progenitors. Methods: We identified a male SZ patient characterized by early disease onset and negative symptoms, who is a carrier of 3 non-synonymous DNMs in genes LRRC7, KHSRP, and KIR2DL1. iPSC lines were generated from his and his parents’ peripheral blood mononuclear cells using Sendai virus-based reprogramming and differentiated into neuronal progenitor cells (NPCs) and hippocampal dentate gyrus granule cells. We used RNASeq to explore transcriptomic differences, and calcium (Ca 2+ ) imaging, cell proliferation, migration, oxidative stress, and mitochondrial assays to characterize the investigated NPC lines. Results: NPCs derived from the SZ patient exhibited transcriptomic differences related to Wnt-signaling, neuronal differentiation, axonal guidance and synaptic function, and decreased Ca 2+ reactivity to glutamate. Moreover, we could observe increased cellular proliferation, and alterations in mitochondrial quantity and morphology. Conclusions: The approach of reprograming case-parent trios represents an opportunity for investigating the molecular effects of disease-causing mutations, and comparing these in cell lines with reduced variation in genetic background. Our results are indicative of a partial overlap between schizophrenia and autism-related phenotypes in the investigated family. Limitations: Our study investigated only one family, therefore the generalizability of findings is limited. We could not derive iPSCs from two other siblings to test for possible genetic effects in the family that are not driven by DNMs. The transcriptomic and functional assays were limited to the NPC stage, although these variables should also be investigated at the mature neuronal stage.

Download Full-text