Project description:This SuperSeries is composed of the following subset Series: GSE24285: Genome-wide Analysis Reveals Mecp2-dependent Regulation of MicroRNAs in a Mouse Model of Rett Syndrome (mm8 chromosomal tiling arrays) GSE24286: Genome-wide Analysis Reveals Mecp2-dependent Regulation of MicroRNAs in a Mouse Model of Rett Syndrome (mm8 promoter tiling arrays) GSE24320: Genome-wide Analysis Reveals Mecp2-dependent Regulation of MicroRNAs in a Mouse Model of Rett Syndrome (high-throughput small RNA sequencing) Refer to individual Series
Project description:Rett syndrome is a human intellectual disability disorder that is associated with mutations in the X-linked MECP2 gene. Theepigenetic reader MeCP2 binds to methylated cytosines on the DNA and regulates chromatin organization. We have shownpreviously that MECP2 Rett syndrome missense mutations are impaired in chromatin binding and heterochromatinreorganization. Here, we performed a proteomics analysis of post-translational modifications of MeCP2 isolated from adult mousebrain. We show that MeCP2 carries various post-translational modifications, among them phosphorylation on S80 and S421, whichlead to minor changes in either heterochromatin binding kinetics or clustering. We found that MeCP2 is (di)methylated on severalarginines and that this modification alters heterochromatin organization. Interestingly, we identified the Rett syndrome mutationsite R106 as a dimethylation site. In addition, co-expression of protein arginine methyltransferases 1 and 6 lead to a decrease ofheterochromatin clustering. Altogether, we identified and validated novel modifications of MeCP2 in the brain and show that thesecan modulate its ability to bind as well as reorganize heterochromatin, which may play a role in the pathology of Rett syndrome.
Project description:We recently identified a mutation in the methyl-binding domain of MECP2 (MECP2 G118E) in a male patient with Rett syndrome. To ask whether this mutation conferred similar molecular dysregulation as observed in previous mouse models of Rett syndrome, we generated a knockin mouse model of this mutation and collected the cortex for RNA-sequencing.
Project description:Genome-wide Analysis Reveals Mecp2-dependent Regulation of MicroRNAs in a Mouse Model of Rett Syndrome (high-throughput sequencing)
Project description:Mutations in methyl-CpG-binding protein 2 (MeCP2), a major epigenetic regulator, are the predominant cause of Rett syndrome, an X-linked neurodevelopmental disorder. We previously found that Mecp2-null microglia are functionally impaired, and that engraftment of wild-type monocytes into the brain of Mecp2-deficient mice attenuates pathology. In this study we show that Mecp2 is expressed in macrophage and monocyte populations throughout the body, and is indispensable for their transcriptional regulation in multiple contexts. We demonstrate that Mecp2-null mice progressively lose or are chronically deficient in several macrophage populations and resident monocytes. Postnatal re-expression of Mecp2 driven by a tamoxifen-inducible CX3CR1 promoter significantly increased the lifespan of otherwise Mecp2-null mice, suggesting that epigenetic regulation of macrophage function by Mecp2 significantly contributes to pathology. RNA-Seq of acutely isolated microglia and peritoneal macrophages (to our knowledge, the first cell-specific RNA-Seq analysis comparing Mecp2-null and wild type cells of any kind) revealed significantly increased transcription of glucocorticoid- and hypoxia-signaling genes in Mecp2-null cells compared to that in their wild-type counterparts, suggesting that Mecp2 functions as a repressor of these pathways. Furthermore, in-vitro and in vivo validation studies demonstrated that the absence of Mecp2 is associated with cell-intrinsic dysfunction of signaling underlying inflammatory activation, suggesting that Mecp2 is important for regulation of specific macrophage gene-expression programs in response to stimuli and stressors. Our findings demonstrate a fundamental role for Mecp2 in the regulation of macrophage functions, which may provide a link to pathologies in Rett syndrome across multiple organs. Mecp2-null microglia and resident peritoneal macrophages from 10-12 week old mice were acutely isolated via AutoMACS, total RNA collected, and analyzed via RNA-Seq to compare for transcriptional differences in microglia and macrophages in the absence of Mecp2.
Project description:Human methyl-CpG-binding protein 2 (MeCP2) disruption causes Rett syndrome, an autistic disease prevalent in females. Previous microarray expression profiling studies using tissue homogenate samples from mouse model of the Rett syndrome revealed only modest changes in expression caused by the loss of Mecp2, making it difficult to identify etiology of the Rett syndrome. Here, we carried out cell type specific genome wide expression profiling of Mecp2 null mice in three neuronal cell types. We found a hot spot of Mecp2 affected genes in chromosome 11B3 syntenic to human chromosome 17p13 which has known associations to mental retardation. We also found Mecp2 affected genes are almost non-overlapping between cell types. Cell-adhesion category of genes, however, are commonly overrepresented, suggesting a possible etiology of Rett syndrome Keywords: cell type comparison, disease state analysis, genetic modification Transgenic mice lines which label subpopulations of neurons (G42: fast spiking Parvarbumin positive interneurons, YFPH: layer 5 thick tufted pyramidal neurons, TH: tyrosine hydroxylase positive locus coeruleus neurons) were used to obtain cell type specific expression profiles on Affymetrix microarrays. Females which carry Mecp2 null alleles (and one of the fluorescent alleles) were crossed with males (which may or may not carry one of the fluorescent alleles depending on whether the female has one or not). Male offsprings at around age P40 which carry fluorescent allele and Mecp2 null allele were used for experiments. Littermate males which carry fluorescent allele but not Mecp2 null allele were used for controls. 3 or 4 biological replicates were done for each condition.
Project description:Rett syndrome is a severe neurodevelopmental condition that rsults primarily from mutations in the MECP2 gene. MECP2 is known to function as both a transcriptional activator and transcriptional repressor. However, it remains unclear how transcriptional dysregulation resulting from MECP2 mutations lead to the Rett syndrome phenotype. Multiple mouse models have been generated to investigate the function of MECP2 in vivo. Remarkably, despite the neurodevelopmental phenotype characteristic of Rett syndrome, temporal conditional MECP2 knock-out mouse models with MECP2 deletion induced postnatally recapitulate the Rett-syndrome-like phenotype in mouse. Here we investigated gene expression changes in 22-weeks old mice following conditional MECP knock-out at 12 weeks by RNA-sequencing. Consistent with previous data, we identify mild gene expression changes following MECP2 knock-out. These data could prove valuable in future studies comparing conditional MECP2 knock-out at distinct time points and in additional brain regions, and can also serve for investigating alternative splicing changes resulting from MECP2 conditional deletion.