Project description:Fragile X syndrome (FXS) is caused by transcriptional silencing of the FMR1 gene during embryonic development with the consequent loss of the encoded fragile X mental retardation protein (FMRP). The pathological mechanisms of FXS have been extensively studied using the Fmr1-knockout mouse, and the findings suggest important roles for FMRP in synaptic plasticity and proper functioning of neural networks. However, the function of FMRP during early neural development in human nervous systems remains to be confirmed. We established human neural progenitor cells (NPCs) as a model for studying FMRP functions and FXS pathology. In order to identify the differentially expressed genes in FMR1KO-NPCs, we performed DNA array analysis on this model.
Project description:Fmr1 mutation results in autistic behaviors and the FMR1 KO mice model is one of the popular methods to study autism spectrum disorders. In this dataset, we include the expression data obtained from astrocytes isolated from cortex of control and FMR1-KO mice.
Project description:Fragile X Syndrome (FXS) is the most common cause of inherited intellectual disabilities and the most prevalent monogenic cause of autism. Although the knockout (KO) of the Fmr1 gene homolog in mice is primarily used for elucidating the neurobiological substrate of FXS, there is limited association of the experimental data with the pathophysiological condition in humans. The use of Fmr1 KO rats offers additional translational validity in this regard. Therefore, we employed a multi-level approach to study the behavioral profile and the glutamatergic and GABAergic neurotransmission status in pathophysiology-associated brain structures of Fmr1 KO rats, including the recordings of evoked and spontaneous field potentials from hippocampal slices, paralleled with next-generation RNA sequencing (RNA-seq). We found that these rats exhibit hyperactivity and cognitive deficits, along with characteristic bidirectional glutamatergic and GABAergic alterations in the prefrontal cortex and the hippocampus. These results are coupled to affected excitability and local inhibitory processes in the hippocampus, along with a specific transcriptional profile, highlighting dysregulated hippocampal network activity in KO rats. Overall, our data provide novel insights concerning the biobehavioral profile of FmR1 KO rats and translationally upscales our understanding on pathophysiology and symptomatology of FXS syndrome.
Project description:N6-methyladenosine (m6A) modification of mRNA is emerging as a vital mechanism regulating RNA function. Here, we show that fragile X mental retardation protein (FMRP), an RNA-binding protein, reads m6A to regulate nuclear export of methylated mRNA targets during neural stem cell differentiation. In Fmr1 KO mice neural progenitors show delayed cell cycle exit and differentiation, resulting in their progressive accumulation in the ventricular and subventricular zones. RNA-seq of neural precursor cells (NPCs) from Fmr1 KO mice and m6A-seq uncovered nuclear retention of m6A-modified FMRP target mRNAs involved in regulating neural differentiation, including components of Notch and Hedgehog signaling pathways. Analysis of NPCs from Mettl14 cKO mice, which are devoid of m6A, revealed that methylation of RNAs promotes their nuclear export through CRM1. Altogether, our findings suggest that FMRP reads and facilitates nuclear export of m6A-modified mRNAs to regulate neural stem cell differentiation, contributing to Fragile X syndrome.
Project description:Fragile X syndrome (FXS) is the most common monogenetic cause of inherited intellectual disability and autism in humans. One of the well-characterized molecular phenotypes of Fmr1 KO mice, a model of FXS, is increased translation of synaptic proteins. Although this upregulation stabilizes in the adulthood, abnormalities during the critical period of plasticity have long-term effects on circuit formation and synaptic properties. Using high-resolution quantitative proteomics of synaptoneurosomes isolated from the adult, developed brains of Fmr1 KO mice, we show differential abundance of proteins regulating postsynaptic receptor activity of glutamatergic synapse. This work includes proteomic dataset that was acquired and analyzed to quantify changes in the abundance of proteins in synaptoneurosomes (basal state, unstimulated and in vitro NMDA-R stimulated) isolated from Fmr1 KO mice and their wild-type littermates.
Project description:TRAP (translating ribosome affinity purification) from CA1 pyramidal neurons and cerebellar granule cells in wildtype and Fmr1 KO littermate pairs. These data show a global downregulation of FMRP targets in Fmr1 KO mice in these cell types.
Project description:The Fragile X Mental Retardation Protein, FMRP, is thought to regulate the translation of a specific set of neuronal mRNAs on polyribosomes. Therefore, we prepared polyribosomes on sucrose gradients and purified mRNA specifically from these fractions, as well as the total mRNA levels, to determine whether a set of mRNAs might be changed in its % association with polyribosomes in the absence of FMRP in the KO mouse model. No significant differences were found, other than the Fmr1 transcript itself, in total mRNA levels or % polyribosome association that withstood multiple test correction, in P7 Fmr1 KO mouse cerebral cortex compared with WT littermates.. We prepared polyribosomes on sucrose gradients from 6 littermate pairs of Fmr1 KO and WT littermates (FVB background, P7 males, cerebral cortex) and purified RNA from both polyribosomal fractions and input to the gradient, reflecting total mRNA levels for comparison.
Project description:Fragile X syndrome (FXS), caused by mutations in fragile X mental retardation 1 gene (FMR1), is a prevailing genetic disorder of intellectual disability and autism. Analysis of transcriptome outcome (differentially expressed genes between WT and Fmr1 KO hippocampal neuron) associated with FXS reveal promising value of gene signature-based computation in repurposing drugs for potential practical treatment.