Project description:FMRP-bound RNAs in hPSC-derived 8 wk neurons were identified using crosslinking immunoprecipitation (CLIP) and Illumina sequencing.
Project description:We identified FMRP-bound RNAs in hPSC (human pluripotent stem cells)-differentiated forebrain neuroprogenitors (NPCs) and neurons using crosslinking immunoprecipitation (CLIP) coupled to high-throughput sequencing. We examined transcriptomic and proteomic changes in FMRP-KO NPCs and neurons.
Project description:Loss of the neuronal RNA binding protein FMRP causes Fragile X Syndrome (FXS), the most common cause of inherited intellectual disability, yet it is unknown which brain regions and cell types within them contribute to disease pathophysiology. We used conditional tagging of FMRP and CLIP (cTag FMRP CLIP) to examine FMRP targets specifically in CA1 hippocampal neurons, a critical cell type for learning and memory known to have altered synaptic function in FXS. Integrating this data with analysis of ribosome-bound transcripts from the same neuronal population revealed CA1-enriched binding of autism-relevant mRNAs, and unexpected CA1-specific regulation of transcripts encoding circadian proteins.
Project description:In this study, we sought to identify the mRNAs associated to FMRP protein in mouse cortical neuron using a cross linking immunoprecipitation and microarray (CLIP-microarray). The mRNAs crosslinked at 254 nm to FMRP in mouse cortical neurons cultured 8 days in vitro (8 DIV) were immunoprecipitated with H120 anti-FMRP (Santa Cruz) and reverse transcribed to labeled cDNAs with Ovation Pico WTA system V2 (Nugen) and hybridized on Mouse Gene 1.0ST (Affymetrix) We analyzed total RNA (Input) and FMRP-CLIPed RNA (Clip) from 10 primary cortical neuron mouse cultures (5 Wt Input, 5 FMR1-KO Input, 5 Wt Clip, 5 FMR1-KO Clip). Array data was processed by Affymetrix Exon Array Computational Tool. No technical replicates were performed.
Project description:We report cell-type and compartment-specific TRAP-seq, RNAseq, FMRP-CLIP, and PAPERCLIP from CA1 hippocampal neurons. We use TRAP-seq and PAPERCLIP data to precisely define the dendritic transcriptome, including mRNAs that harbor APA and AS events that are differentially localized. Further, we use FMRP-CLIP in order to define mRNAs that undergo compartment-specific regulation by FMRP.
Project description:In this study, we sought to identify the mRNAs associated to FMRP protein in mouse cortical neuron using a cross linking immunoprecipitation and microarray (CLIP-microarray). The mRNAs crosslinked at 254 nm to FMRP in mouse cortical neurons cultured 8 days in vitro (8 DIV) were immunoprecipitated with H120 anti-FMRP (Santa Cruz) and reverse transcribed to labeled cDNAs with Ovation Pico WTA system V2 (Nugen) and hybridized on Mouse Gene 1.0ST (Affymetrix)
Project description:Fragile X syndrome (FXS) is the most common inherited form of intellectual disability and a leading genetic cause of autism. FXS is caused by the loss of functional fragile X mental retardation protein (FMRP). FMRP is an RNA-binding protein forming a messenger ribonucleoprotein complex with polyribosomes in the regulation of protein synthesis at synapses. Three-dimensional (3D) aggregate culture of human-induced pluripotent stem cells (iPSCs) has evolved from embryoid body cultures, quite faithfully following human organogenesis, and provides a new platform to investigate human brain development in a dish, otherwise inaccessible to experimentation. To determine whether the loss of FMRP could alter the development of human brain organoids, we have generated forebrain organoids from three FXS male patients and three healthy male controls. We observed reduced proliferation of neural progenitor cells and premature neural differentiation as well as perturbed cell cycle progression in FXS forebrain organoids. There is also a deficit in the production of GABAergic neurons as well as an altered balance between the number of excitatory and inhibitory neurons in FXS organoids. Interestingly these deficits were not observed with FXS mouse model. To compare the differential gene expression caused by the loss of FMRP between human and mouse, we then performed RNA-seq to identify the differentially expressed genes using both mouse embryonic brain cortex and human forebrain organoids at the comparable developmental stages. We detected very few genes differentially expressed in the absence of Fmrp in mouse. However, we identified 200 genes downregulated and 126 genes up-regulated in human FXS organoids, indicating human-specific impact caused by the loss of FMRP. Our bulk RNA-seq analyses revealed a more pervasive gene expression alteration in human organoids. Thus, it is plausible to speculate that there could be important human-specific genes that might be related with FXS pathogenesis. To test this idea, we used human forebrain organoids and the mouse embryonic brains in parallel to perform enhanced crosslinking and FMRP immunoprecipitation followed by high-throughput sequencing and bioinformatics analysis (CLIP-seq). Our analyses identified more than 3,700 mRNA bound by FMRP in human organoids. Of the 3,700 mRNAs, ~1,600 overlapped with mouse mRNAs. Further, ~80% of the identified mouse mRNA species overlap with previously published results in mouse. To better understand the developmental, cellular and molecular changes and to gain insight beyond bulk gene expression analysis in forebrain organoids from FXS patients compared to control, we next performed single cell RNA-seq (scRNA-seq) to characterize distinct cell populations, specific cell types and cell states. We found that the population of specific neuron type were changed upon the loss of FMRP. Next, investigated if there were developmental differences in the transitioning from the early, primitive state to one of the more committed end states between control and FXS organoids, with many cells distributed along a “trajectory” between them. we found several bifurcation points of FXS cells from the general trajectory, and the cells of these subpopulations with altered neuronal states are strongly enriched for FXS. These results together suggest that the loss of FMRP could cause neurodevelopmental deficits specifically in human, and fragile X organoids could provide a unique platform to study the molecular pathogenesis of FXS and identify human-specific druggable targets for FXS and autism in general.
Project description:We report cell-type and compartment-specific TRAP-seq, RNAseq, FMRP-CLIP, and PAPERCLIP from CA1 hippocampal neurons. We use TRAP-seq and PAPERCLIP data to precisely define the dendritic transcriptome, including mRNAs that harbor APA and AS events that are differentially localized. Further, we use FMRP-CLIP in order to define mRNAs that undergo compartment-specific regulation by FMRP.