Project description:22q11.2 deletion syndrome (22q11DS) is a common cause of developmental neuropsychiatric disorders, including psychosis, autism and epilepsy. This highly penetrant genetic syndrome provides a unique opportunity to mitigate the challenges raised by the heterogeneity of complex mental disorders and to identify specific neuronal phenotypes. Here, we generated induced pluripotent stem cells from subjects carrying a 3 Mb deletion at the 22q11.2 locus and from controls and differentiated these cells in vitro into three-dimensional organoid resembling the developing cerebral cortex. We performed single-cell RNA-sequencing to establish the reliability and reproducibility of cortical organoid differentiation in 22q11DS.
Project description:The 22q11.2 deletion syndrome (22q11.2DS) is the most common copy number variant (CNV)-associated syndrome, leading to congenital and neuropsychiatric anomalies. Patient-derived, induced pluripotent stem cell (iPS) models have provided important insight into the mechanisms of phenotypic features of this condition. However, patient-derived iPSC models may harbor underlying genetic heterogeneity that can confound analysis of pathogenic CNV effects. Furthermore, the ~1.5 Mb “A-B” deletion at this locus is inherited at higher frequency than the more common ~2.7 Mb “A-D” deletion, but remains under-studied due to lack of relevant models. To address these issues, here we leveraged a CRISPR-based strategy in Cas9-expressing iPS cells to engineer novel isogenic models of the 22q11.2 “A-B” deletion. After in vitro differentiation to excitatory neurons, integrated transcriptomic and cell surface proteomics identified deletion-associated alterations in surface adhesion markers. Furthermore, implantation of iPS-derived neuronal progenitor cells into the cortex of neonatal mice found decreased proliferation and accelerated neuronal maturation within a relevant microenvironment. Taken together, our results suggest potential pathogenic mechanisms of the 22q11.2 “A-B” deletion in driving neuronal and neurodevelopmental phenotypes. We further propose that the isogenic models generated here will provide a unique resource to study this less-common variant of the 22q11.2 microdeletion syndrome.
Project description:Adults and children with the 22q11.2 Deletion Syndrome demonstrate cognitive, social and emotional impairments and high risk for schizophrenia. Work in mouse model of the 22q11.2 deletion provided compelling evidence for abnormal expression and processing of microRNAs. A major transcriptional effect of the microRNA dysregulation is up-regulation of Emc10, a component of the ER membrane complex, which promotes membrane insertion of a subset of polytopic and tail-anchored membrane proteins. We previously uncovered a key contribution of EMC10 in mediating the behavioral phenotypes observed in 22q11.2 deletion mouse models. Here we show that expression and processing of miRNAs is abnormal and EMC10 expression is elevated in neurons derived from 22q11.2 deletion carriers. Reduction of EMC10 levels restores defects in neurite outgrowth and calcium signaling in patient neurons. Furthermore, antisense oligonucleotide administration and normalization of Emc10 in the adult mouse brain not only alleviates cognitive deficits in social and spatial memory but remarkably sustains these improvements for over two months post injection, indicating its therapeutic potential. Broadly, our study integrates findings from both animal models and human neurons to elucidate the translational potential of modulating EMC10 levels and downstream targets as a specific venue to ameliorate disease progression in 22q11.2 Deletion Syndrome.
Project description:Adults and children with the 22q11.2 Deletion Syndrome demonstrate cognitive, social and emotional impairments and high risk for schizophrenia. Work in mouse model of the 22q11.2 deletion provided compelling evidence for abnormal expression and processing of microRNAs. A major transcriptional effect of the microRNA dysregulation is up-regulation of Emc10, a component of the ER membrane complex, which promotes membrane insertion of a subset of polytopic and tail-anchored membrane proteins. We previously uncovered a key contribution of EMC10 in mediating the behavioral phenotypes observed in 22q11.2 deletion mouse models. Here we show that expression and processing of miRNAs is abnormal and EMC10 expression is elevated in neurons derived from 22q11.2 deletion carriers. Reduction of EMC10 levels restores defects in neurite outgrowth and calcium signaling in patient neurons. Furthermore, antisense oligonucleotide administration and normalization of Emc10 in the adult mouse brain not only alleviates cognitive deficits in social and spatial memory but remarkably sustains these improvements for over two months post injection, indicating its therapeutic potential. Broadly, our study integrates findings from both animal models and human neurons to elucidate the translational potential of modulating EMC10 levels and downstream targets as a specific venue to ameliorate disease progression in 22q11.2 Deletion Syndrome.
Project description:The 22q11.2 deletion syndrome (22q11.2DS) is the most common copy number variant (CNV)-associated syndrome, leading to congenital, cognitive, and neuropsychiatric anomalies in patients. The clinical presentation of the disease phenotypes is variable, posing significant challenges for prognosis of inheritance risk and clinical outcomes for the CNV carriers. ~85% of patients and almost all available human-centered models of this condition reflect the ~2.7 Mb “A-D” deletion at this locus. Leveraging a CRISPR/Cas9-based engineering strategy and induced pluripotent stems cells, we generated novel isogenic models for the smaller, commonly inherited 1.5 Mb “A-B” deletion found in ~5-10% of 22q11.2DS patients. The bulk RNA-seq data included here reflects paired-end 100 bp sequencing of iPSC-derived neuronal progenitor cells and excitatory neurons. These data reflect three independent clones either carrying the designed 22q11.2 deletion or control comparators (2 clones nucleofected with same sgRNA but with no deletion generated; 1 clone derived from the parental Cas9-expressing iPSC line). We anticipate that these novel, isogenic models will carry significant utility for the study of 22q11.2 deletion syndrome.
Project description:Adults and children with the 22q11.2 deletion syndrome (22q11.2DS) demonstrate cognitive, social and emotional impairments and markedly increased risk for schizophrenia (SCZ). The alterations in early human brain development resulting from this deletion remain unclear. Here we use organoid models of the developing human cerebral cortex derived from patients with 22q11.2DS and SCZ as well as unaffected controls to identify cell-type-specific developmental abnormalities that result from this genomic lesion. Using RNA-sequencing and follow-up experimental validation we find that loss of genes within the 22q11.2 locus leads to delayed development of cortical neurons.
Project description:Adults and children with the 22q11.2 deletion syndrome (22q11.2DS) demonstrate cognitive, social and emotional impairments and markedly increased risk for schizophrenia (SCZ). The alterations in early human brain development resulting from this deletion remain unclear. Here we use organoid models of the developing human cerebral cortex derived from patients with 22q11.2DS and SCZ as well as unaffected controls to identify cell-type-specific developmental abnormalities that result from this genomic lesion. Using RNA-sequencing and follow-up experimental validation we find that loss of genes within the 22q11.2 locus leads to delayed development of cortical neurons.