Project description:Dysregulation of Sonic hedgehog (SHH) signaling may contribute to multiple Down syndrome-associated phenotypes, including cerebellar hypoplasia, congenital heart defects, craniofacial and skeletal dysmorphologies, and Hirschsprung disease. Granule cell precursors isolated from the developing cerebellum of Ts65Dn mice are less responsive to the mitogenic effects of SHH than euploid cells, and a single postnatal dose of the SHH pathway agonist SAG rescues cerebellar morphology and performance on learning and memory tasks in Ts65Dn mice. SAG treatment also normalizes expression levels of OLIG2 in neural progenitor cells derived from human trisomy 21 iPSCs. However, despite evidence that activating SHH signaling rescues Down syndrome-associated phenotypes, chromosome 21 does not encode any canonical components of the SHH pathway. Here, we screened 163 chromosome 21 cDNAs in a series of SHH-responsive cell lines to identify chromosome 21 genes that modulate SHH signaling and confirmed overexpression of trisomic candidate genes using RNA-seq in Ts65Dn and TcMAC21 cerebellum. Our study indicates that some chromosome 21 genes, including DYRK1A, activate SHH signaling while others, such as HMGN1 and MIS18A, inhibit SHH signaling. Moreover, overexpression of genes involved in chromatin structure and mitosis, but not genes previously implicated in ciliogenesis, regulate the SHH pathway. Our data suggest that cerebellar hypoplasia and other phenotypes related to aberrant SHH signaling arise from the net effect of trisomy for multiple chromosome 21 genes rather than the overexpression of a single trisomic gene. Identifying which chromosome 21 genes modulate SHH signaling may also suggest new therapeutic avenues for ameliorating Down syndrome phenotypes.
Project description:The goal of the study was to analize expression of cell cycle related genes during postnatal development of Ts65Dn (Down syndrome mouse model) and control mice cerebellum. Keywords: Gene expression study in mouse model of disease RNA from 3 controls and 3 Ts65Dn postnatal day 2 cerebellum were analized on separate arrays.
Project description:The goal of the study was to analize expression of cell cycle related genes during postnatal development of Ts65Dn (Down syndrome mouse model) and control mice cerebellum. Keywords: Gene expression study in mouse model of disease
Project description:Transcriptome analysis of Ts1Cje (mouse model of Down syndrome) and euploids murine cerebellum during postnatal development Keywords = Down syndrome Keywords = Chromosome 21 Keywords = Transcriptome Keywords = Microarray Keywords = Cerebellum Keywords = Development Keywords: other
Project description:Despite the growing importance of the cortico-cerebellar-thalamo-cortical circuit in schizophrenia, limited information is available regarding altered molecular networks in cerebellum. To identify altered protein networks, we conducted proteomic analysis of grey matter of postmortem cerebellar cortex in chronic schizophrenia subjects (n=12) and healthy individuals (n=14) followed by an extensive bioinformatic analysis. Two double-hit postnatal stress murine models for SZ were used to validate the most robust candidates.
Project description:Down syndrome (DS), a genetic condition leading to intellectual disability, is characterized by triplication of human chromosome 21. Neuropathological hallmarks of DS include abnormal central nervous system development that manifests during gestation and extends throughout life. As a result, newborns and adults with DS exhibit cognitive and motor deficits and fail to meet typical developmental and lack independent life skills. A critical outstanding question is how DS-specific prenatal and postnatal phenotypes are recapitulated in different mouse models. To begin answering this question, we developed a life span approach to directly compare differences in embryonic brain development, cellularity, gene expression, neonatal and adult behavior behavior in three cytogenetically distinct mouse models of DS—Ts1Cje, Ts65Dn and Dp16/1Yey (Dp16). In the last two decades multiple therapeutic trials have been attempted to improve cognition in humans with DS but the results of these interventions lacked efficacy despide their succes in the Ts65Dn mouse model of DS. To better understand how phenotypic changes in humans in DS are recapitulated in different mouse models, we copared embryonic brain development and gene expression, perinatal behavior and brain excitatoty/inhibitory cell distribution, and adult behavior and gene expression in the Dp16, Ts65Dn and Ts1Cje mouse models of DS. The objectives of this study were to determine the best model(s) for prenatal and postnatal therapeutic trials and to identify treatment endpoints that can be used to evaluate the fficacy of these therapies prior to human clinical trials. Our data showed that, at embryonic day 15.5, Ts65Dn mice are the most profoundly and consistently affected with respect to somatic growth, brain morphogenesis, and neurogenesis compared to Ts1Cje and Dp16 embryos. However, gene expression results show that both Ts65Dn and Ts1Cje embryonic forebrains have a relatively high number of differentially expressed genes compared to Dp16, with little overlap in gene identities and genomic distribution observed among these models. Additionally, postnatal histological analyses show varying degrees of cell population and brain histogenesis abnormalities among the three strains. Behavioral testing also highlights differences among the models in their ability to meet various developmental milestones. At adulthood, Ts65Dn and Ts1Cje showed hyperactive behavior in the open field test but not Dp16 mice. In the fear conditioning test, all three strains showed lower freezing versus eupploid mice; Dp16 were the most severely affected. In the Morris water maze, Ts65Dn showed significant delays in the hidden platform, probe and reversal trials. Dp16 mice showed milder deficits in the hidden platform trial but severe deficits in reversal. Ts1Cje mice had no spatial memory deficits. In the rotarod test, Dp16 performed poorly in fixed and accelerating speed trials, while Ts1Cje was only abnormal at high speeds. Ts65Dn rotarod performance was unaffected. Compared to euploid, Ts65Dn had a higher number of differentially expressed (DEX) genes in cortex and cerebellum, while Ts1Cje had more DEX genes in hippocampus and cerebellum. Dp16 had the lowest number of DEX genes in all regions analyzed. Pathway analyses highlighted commonly dysregulated pathways, including G-protein signaling, oxidative stress, interferon signaling, glycosylation and disulfide bonds.
Project description:Transcriptome analysis of Ts1Cje (mouse model of Down syndrome) and euploids murine cerebellum during postnatal development Keywords = Down syndrome Keywords = Chromosome 21 Keywords = Transcriptome Keywords = Microarray Keywords = Cerebellum Keywords = Development Keywords: other
Project description:We generated single-cell RNAseq profiles of 143 microglia, sorted in the gate CD45lowCD11+Gpnmb+Clec7a+, from postnatal day 7 cerebellum to validate the newly identified “proliferative region-associated microglia (PAM)” (Gpnmb and Clec7a are PAM surface markers). Single cells were FACS index sorted followed by Smart-seq2 library preparation and Illumina Nextseq (sequence depth > 1 million per cell). These cells showed characteristic PAM gene expression and clustered together with other PAM cells sequenced in the same study.