Project description:Gene expression profiling of striatum in R6/2 Huntington’s disease (HD) model mouse. Striatum gene set contained gene expression alterations in other neuronal populations, such as oligodendrocyte, astrocyte, microglia and interneuron.
Project description:We performed cell-type specific RNAseq in astrocytes and neurons in the presence or absence of ZFP transcriptional repressors in the striatum of R6/2 mouse model of HD.
Project description:This dataset allows for the exploration of gene expression of microdissected striatum from 11 week old wild-type and the R6/2 mouse model of Huntington's disease, in the presence or absence of microglia. Microglia were depleted via dietary administration of the CSF1R inhibitor PLX3397 from 6 to 11 weeks of age.
Project description:Transcriptional dysregulation is an early feature of Huntington's disease (HD). We observed gene-specific changes in H3K4me3 at transcriptionally repressed promoters in R6/2 mouse and human HD brain. Genome-wide analysis showed a novel chromatin signature for this mark. Reducing the levels of the H3K4 demethylase SMCX/Jarid1c in primary neurons reversed down-regulation of key neuronal genes caused by mutant Huntingtin (Htt) expression. Finally, reduction of SMCX/Jarid1c in primary neurons from BACHD mice or the single Jarid1 in a Drosophila HD model was protective. Therefore, targeting this epigenetic signature may be an effective strategy to ameliorate the consequences of HD. ChIP-seq for H3K4me3 in wild type and R6/2 cortex and striatum at 8 and 12 weeks.
Project description:Huntington’s disease is a fatal autosomal dominant neurodegenerative disorder, characterized by neuronal cell loss, primarily in the striatum, cortex, and hippocampus, causing motor, cognitive, and psychiatric impairments. Unfortunately, no treatments are yet available to modify the progression of the disease. Recent evidence from Huntington’s disease mouse models suggests that protein phosphorylation (catalysed by kinases and hydrolysed by phosphatases) might be dysregulated, making this major posttranslational modification a potential area of interest to find novel therapeutic targets. Furthermore, environmental enrichment (EE), used to model an active lifestyle in preclinical models, has been shown to alleviate Huntington’s disease-related motor and cognitive symptoms. However, the molecular mechanisms leading to these therapeutic effects are still largely unknown. In this study, we applied a phosphoproteomics approach combined with proteomic analyses on brain samples from pre-motor symptomatic R6/1 Huntington’s disease male mice (HD mice) and their wild-type (WT) littermates, after being housed either in EE conditions, or in standard housing (SH) conditions from 4 to 8 weeks of age (n=6 per group). We hypothesised that protein phosphorylation dysregulations occur prior to motor onset in this mouse model, in two highly affected brain regions, the striatum and hippocampus. Furthermore, we hypothesised that these phosphoproteome alterations are rescued by EE. When comparing 8-week-old HD mice and WT mice in SH conditions, our analysis revealed 229 differentially phosphorylated peptides in the striatum, compared to only 15 differentially phosphorylated peptides in the hippocampus (statistical thresholds FDR0.05, FC1.5). At the same disease stage, minor differences were found in protein expression, with 24 and 22 proteins dysregulated in the striatum and hippocampus, respectively. Notably, we found no differences in striatal protein phosphorylation and protein expression when comparing HD mice and their WT littermates in EE conditions. In the hippocampus, only four peptides were differentially phosphorylated between the two genotypes under EE conditions, and 22 proteins were differentially expressed. Together, our data indicates that protein phosphorylation dysregulations occur in the striatum of HD mice, prior to motor symptoms, and that the kinases and phosphatases leading to these changes in protein phosphorylation might be viable drug targets to consider for this disorder. Furthermore, we show that an early environmental intervention was able to rescue the changes observed in protein expression and phosphorylation in the striatum of HD mice and might underlie the beneficial effects of EE, thus identifying novel therapeutic targets.
Project description:Purpose: Transcriptome profiling (RNA-seq) to microarray to evaluate transcriptional changes in the heart of HD mouse models Methods: Heart mRNA profiles of 4-weeks-old wild-type (WT) and R6/2 transgenic; 15-weeks-old WT and R6/2 transgenic mice; 8-month-old WT and HdhQ150 knock-in mice; 22-month-old WT and HdhQ150 knock-in mice were generated by deep sequencing, in triplicate, using Illumina Hi-seq 2000. Conclusions: Our study showed that there is no major transcriptional deregulation in the heart of mouse models of HD.
Project description:Deregulated intracellular Ca2+ homeostasis underlies synaptic dysfunction and is a common feature in neurodegenerative processes, including Huntington's disease (HD). DREAM/calsenilin/KChIP-3 is a multifunctional Ca2+ binding protein that controls the expression level and/or the activity of several proteins related to Ca2+ homeostasis, neuronal excitability and neuronal survival. We found that expression of endogenous DREAM (DRE antagonist modulator) is reduced in the striatum of R6 mice, in STHdh-Q111/111 knock in striatal neurons and in HD patients. DREAM down regulation in R6 striatum occurs early after birth, well before the onset of motor coordination impairment, and could be part of an endogenous mechanism of neuroprotection, since i) R6/2 mice hemizygous for the DREAM gene (R6/2xDREAM+/-) showed delayed onset of locomotor impairment and prolonged lifespan, ii) motor impairment after chronic administration of 3-NPA was reduced in DREAM knockout mice and enhanced in daDREAM transgenic mice and, iii) lentiviral-mediated DREAM expression in STHdh-Q111/111 knock in cells sensitizes them to oxidative stress. Transcriptomic analysis showed that changes in gene expression in R6/2 striatum were notably reduced in R6/2xDREAM+/- striatum. Chronic administration of repaglinide, a molecule able to bind to DREAM in vitro and to accelerate its clearance in vivo, delayed the onset of motor dysfunction, reduced striatal loss and prolonged the lifespan in R6/2 mice. Furthermore, exposure to repaglinide protected STHdh-Q111/111 knock in striatal neurons sensitized to oxidative stress by lentiviral-mediated DREAM overexpression. Thus, genetic and pharmacological evidences disclose a role for DREAM silencing in early neuroprotective mechanisms in HD.
Project description:Transcriptional dysregulation is an early feature of Huntington's disease (HD). We observed gene-specific changes in H3K4me3 at transcriptionally repressed promoters in R6/2 mouse and human HD brain. Genome-wide analysis showed a novel chromatin signature for this mark. Reducing the levels of the H3K4 demethylase SMCX/Jarid1c in primary neurons reversed down-regulation of key neuronal genes caused by mutant Huntingtin (Htt) expression. Finally, reduction of SMCX/Jarid1c in primary neurons from BACHD mice or the single Jarid1 in a Drosophila HD model was protective. Therefore, targeting this epigenetic signature may be an effective strategy to ameliorate the consequences of HD. mRNA-seq in wild type and R6/2 cortex and striatum at 8 and 12 weeks.
Project description:Animal models play a critical role in the study of Huntington’s disease (HD), for example to elucidate underlying molecular mechanisms or to develop novel therapeutic venues. One of the first transgenic mouse models of HD, the R6/2 line, has been described in 1996 and has since become one of the most studied models of the disease (Mangiarini et al. 1996; Li, Popovic & Brundin 2005). R6/2 mice express the human exon 1 under control of the human huntingtin promoter at around 75% of the endogenous levels. The expression of the exon 1 with a CAG repeat length of around 115 evokes rapid disease progression and animals display multiple HD-associated neuropathological changes. First signs of disease can occur as early as three weeks and mice are severely impaired by the age of 8-12 weeks. The expected life span is 13-16 weeks (Li, Popovic & Brundin 2005). Here we were interested in the changes occurring in the proteomic landscape as well as in phosphoproteomic signaling networks in the R6/2 mouse model as compared to wild type mice. To this end, we performed comprehensive quantitative phosphoproteome and proteome analyses of striatum of one, two, and three months old mice of both genotypes. A total of nine or more samples per group was analyzed according to the experimental layout shown above. To allow for accurate quantification, peptides of each sample were labelled using tandem mass tags (TMT) and replicates of different conditions were combined. Each combined sample contained an aliquot of a pooled sample consisting of 12 sample lysates. This pooled sample was intended to serve as a reference to allow for quantitative comparison between all combined samples.
Project description:To describe the protein profile in hippocampus, colon and ileum tissue’ changing after the old faeces transplants, we adopted a quantitative label free proteomics approach.