Rett syndrome is caused by mutations in the gene encoding methyl-CpG binding protein 2 (MECP2), an epigenetic regulator of mRNA transcription. Here we report a test of the hypothesis of shared pathophysiology of Rett syndrome and fragile X, another monogenic cause of autism and intellectual disability. In fragile X, the loss of the mRNA translational repressor FMRP leads to exaggerated protein synthesis downstream of metabotropic glutamate receptor 5 (mGluR5). We found that mGluR5- and protein synthesis-dependent synaptic plasticity is similarly altered in area CA1 of Mecp2 KO mice. CA1 pyramidal cell-type-specific, genome-wide profiling of ribosome-bound mRNAs was performed in wild-type and Mecp2 KO hippocampal CA1 neurons to reveal the MeCP2-regulated 'translatome'. We found significant overlap between ribosome-bound transcripts overexpressed in the Mecp2 KO and FMRP mRNA targets. These tended to encode long genes that are functionally related to either cytoskeleton organization or the development of neuronal connectivity. In the Fmr1 KO mouse, chronic treatment with mGluR5 negative allosteric modulators (NAMs) has been shown to ameliorate many mutant phenotypes by correcting excessive protein synthesis. In the Mecp2 KO mice we found that mGluR5 NAM treatment significantly reduces the level of overexpressed ribosome-associated transcripts, particularly those that are also FMRP targets. Some Rett phenotypes were also ameliorated by treatment, most notably hippocampal cell size and life span. Together, these results suggest a potential mechanistic link between MeCP2-mediated transcription regulation and mGluR5/FMRP-mediated protein translation regulation through co-regulation of a subset of genes relevant to synaptic functions. Overall design: TRAP-seq analysis of the effect of negative modulator of mGluR5 on the CA1 neurons (marked by Cck-EGFP-L10a) of a mouse model of Rett syndrome
Negative Allosteric Modulation of mGluR5 Partially Corrects Pathophysiology in a Mouse Model of Rett Syndrome.
Specimen part, Cell line, Treatment, Subject
View SamplesExcessive mRNA translation downstream of group I metabotropic glutamate receptors (mGlu1/5) is a core pathophysiology of fragile X syndrome (FX), however the differentially translating mRNAs that contribute to altered neural function are not known. We used Translating Ribosome Affinity Purification (TRAP) and RNA-seq to identify mistranslating mRNAs in CA1 pyramidal neurons of the FX mouse model (Fmr1-/y) hippocampus, which exhibit exaggerated mGlu1/5-induced long-term synaptic depression (LTD). In these neurons, we find the Chrm4 transcript encoding muscarinic acetylcholine receptor 4 (M4) is excessively translated, and synthesis of M4 downstream of mGlu5 activation is mimicked and occluded. Surprisingly, enhancement rather than inhibition of M4 activity normalizes core phenotypes in the Fmr1-/y, including excessive protein synthesis, exaggerated mGluR-LTD, and audiogenic seizures. These results suggest that not all excessively translated mRNAs in the Fmr1-/y brain are detrimental, and some may be candidates for enhancement to correct pathological changes in the FX brain. Overall design: 6 biological replicates of total hippocampal mRNA (Input) from WT and Fmr1 KO littermate pairs and CA1-TRAP-IP (IP) from the same 6 WT and KO littermate pairs.
Cell-Type-Specific Translation Profiling Reveals a Novel Strategy for Treating Fragile X Syndrome.
Sex, Specimen part, Cell line, Subject
View SamplesWe investigated the molecular mechanisms of chronic alcohol consumption or lipopolysaccharide insult by gene expression profiling in prefrontal cortex and liver of C57BL/6J mice.
Gene expression in brain and liver produced by three different regimens of alcohol consumption in mice: comparison with immune activation.
Age, Specimen part
View SamplesAnalysis of the transcriptional changes in the heart resulting from the loss of cardiac enhancers. As there remains a limited understanding of the phenotypic consequences of enhancer mutations, we examined the impact of loss of function mutations by deleting two enhancers near heart disease genes in mice. In both cases, we observed loss of target gene expression, as well as cardiac phenotypes consistent with heart disease in humans, highlighting the functional importance of enhancers for normal heart function, as well as the potential contribution of enhancer mutations to heart disease. Overall design: Hearts were dissected from wild-type and enhancer-null mice (either embryonic or adult) and processed for deep RNA-seq analysis.
Genome-wide compendium and functional assessment of in vivo heart enhancers.
Sex, Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A high protein diet during pregnancy affects hepatic gene expression of energy sensing pathways along ontogenesis in a porcine model.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcriptional response of skeletal muscle to a low-protein gestation diet in porcine offspring accumulates in growth- and cell cycle-regulating pathways.
Specimen part
View SamplesGerman landrace gilts were fed a high protein diet (HP, 30% CP) throughout their whole pregnancy. Subsequently hepatic transcriptome profiles of the offspring were analysed at prenatal (94 dpc) and postnatal stages (1, 28, 188 dpn)
A high protein diet during pregnancy affects hepatic gene expression of energy sensing pathways along ontogenesis in a porcine model.
Specimen part
View SamplesGerman landrace gilts were fed an adequate protein diet (AP, 12% CP) throughout their whole pregnancy. Subsequently hepatic transcriptome profiles of the offspring were analysed at prenatal (94 dpc) and postnatal stages (1, 28, 188 dpn).
A high protein diet during pregnancy affects hepatic gene expression of energy sensing pathways along ontogenesis in a porcine model.
Specimen part
View SamplesGerman landrace gilts were fed a high protein diet (HP, 30% CP) throughout their whole pregnancy. Subsequently muscle transcriptome profiles of the offspring were analysed at prenatal (94 dpc) and postnatal stages (1, 28, 188 dpn)
Transcriptional response of skeletal muscle to a low-protein gestation diet in porcine offspring accumulates in growth- and cell cycle-regulating pathways.
Specimen part
View SamplesGerman landrace gilts were fed a low protein diet (LP, 6% CP) throughout their whole pregnancy. Subsequently muscle transcriptome profiles of the offspring were analysed at prenatal (94 dpc) and postnatal stages (1, 28, 188 dpn)
Transcriptional response of skeletal muscle to a low-protein gestation diet in porcine offspring accumulates in growth- and cell cycle-regulating pathways.
Specimen part
View Samples