Project description:Primary neuron model of Huntington's Disease. 2 treatment groups: A) Infected 4 weeks prior with TRE-Htt-N853-18Q-expressing recombinant lentivirus, B) Infected 4 weeks prior with TRE-Htt-N853-82Q-expressing recombinant lentivirus Experiment Overall Design: Primary neurons samples infected with TRE-Htt-N853-18Q or -82Q.
Project description:Primary neuron model of Huntington's Disease. 2 treatment groups: A) Infected 4 weeks prior with TRE-Htt-N853-18Q-expressing recombinant lentivirus, B) Infected 4 weeks prior with TRE-Htt-N853-82Q-expressing recombinant lentivirus Keywords: gene expression study
Project description:Huntington's disease (HD) is characterized by the aggregation of polyglutamine-expanded huntingtin (HTT), proceeding from soluble oligomers to end-stage inclusions. The molecular mechanisms of how protein aggregation leads to neuronal dysfunction are not well understood. We employed mass spectrometry-based quantitative proteomics to dissect spatiotemporal mechanisms of neurodegeneration using the R6/2 mouse model of HD. We show that extensive remodeling of the soluble brain proteome correlates with changes in insoluble aggregate formation during disease progression. In-depth characterization of HTT inclusion bodies uncovered an unprecedented complexity of several hundred proteins. Sequestration to inclusions was dependent on protein expression levels and the presence of aggregation-prone amino acid sequence features, such as low-complexity regions or coiled-coil domains. Overexpression of several sequestered proteins ameliorated HTT toxicity and modified the aggregation behavior in an in vitro model of HD. Our study provides a comprehensive and spatiotemporally-resolved proteome resource of HD progression, indicating that widespread loss of protein function contributes to aggregate-mediated toxicity.
Project description:Transcriptional changes are an early feature of Huntington's disease (HD). We profiled genome-wide interaction sites for the huntingtin protein (HTT) using ChIP-sequencing from mouse striatal tissue at 4 months of age. We include replicate samples from CAG-expanded murine Htt (heterozygous Q111/+) and wildtype littermate controls.
Project description:We used microarrays to investigate whether transcriptional dysregulation in hypothalamus is caused by expression of the huntingtin (HTT) protein We used two different Huntington's disease mouse models: BACHD mice with ubiquitous full-length mutant HTT expression (97 CAG repeats) and wild-type mice with targeted bilateral injections of wild-type or mutant HTT (853 amino acids length, wild-type HTT: 18 CAG repeats, mutant HTT: 79 CAG repeats) in hypothalamus.
Project description:In Huntington's disease (HD), polyglutamine expansions in the huntingtin (Htt) protein cause subtle changes in cellular functions that, over-time, lead to neurodegeneration and death. Studies have indicated that activation of the heat shock response can reduce many of the effects of mutant Htt in disease models, suggesting that the heat shock response is impaired in the disease. To understand the basis for this impairment, we have used genome-wide chromatin immunoprecipitation followed by massively parallel sequencing (ChIP-Seq) to examine the effects of mutant Htt on the master regulator of the heat shock response, HSF1. We find that, under normal conditions, HSF1 function is highly similar in cells carrying either wild-type or mutant Htt. However, polyQ-expanded Htt severely blunts the HSF1-mediated stress response. Surprisingly, we find that the HSF1 targets most affected upon stress are not directly associated with proteostasis, but with cytoskeletal binding, focal adhesion and GTPase activity. Our data raise the intriguing hypothesis that the accumulated damage from life-long impairment in these stress responses may contribute significantly to the etiology of Huntington's disease. Affymetrix MG430 2.0 expression levels of wild-type (STHdhQ7/Q7) and mutant (STHdhQ111/Q111) striatal cells under growth condition (33 C) and upon heat shock (42 C for six hours)
Project description:Huntington's disease (HD) is a dominantly inherited genetic disease caused by mutant huntingtin (htt) protein with expanded polyglutamine tracts. A neuropathological hallmark of HD is the presence of neuronal inclusions of mutant htt. p62 is an important regulatory protein in selective autophagy, a process by which aggregated proteins are degraded, and it is associated with several neurodegenerative disorders including HD. Here we investigated the effect of p62 depletion in three HD model mice: R6/2, HD190QG and HD120QG mice. We found that loss of p62 in these models led to longer lifespans and reduced nuclear inclusions, although cytoplasmic inclusions increased with polyglutamine length. In mouse embryonic fibroblasts (MEFs) with or without p62, mutant htt with a nuclear localization signal (NLS) showed no difference in nuclear inclusion between the two MEF types. In the case of mutant htt without NLS, however, p62 depletion increased cytoplasmic inclusions. Furthermore, to examine the effect of impaired autophagy in HD model mice, we crossed R6/2 mice with Atg5 conditional knockout mice. These mice also showed decreased nuclear inclusions and increased cytoplasmic inclusions, similar to HD mice lacking p62. These data suggest that the genetic ablation of p62 in HD model mice enhances cytoplasmic inclusion formation by interrupting autophagic clearance of polyQ inclusions. This reduces polyQ nuclear influx and paradoxically ameliorates disease phenotypes by decreasing toxic nuclear inclusions. Gene expression profiles were analyzed to examine the effects of p62 depletion in mouse with or without mutant huntingtin exon 1 To examine the effect of p62 depletion on the transcriptome of Huntington's disease model mice, we crossed p62 knockout mice with HD model mice. We extracted total RNA from the striatum of these mice at 8 weeks and used for a microaaray analysis. The samples are HD transgenic mice with p62 knockout (HD_p62KO), HD mice with normal p62 (HD_p62WT), non-HD-transgenic mice with p62 knockout (NT_p62KO), and non-HD-transgenic mice with normal p62 (NT_p62WT).
Project description:Few studies have assessed the patterns of parasite populations of rodents over a longitudinal gradient in Chile. In this work, the gastrointestinal helminthic fauna of invasive rodents in Chile was examined to assess the association between their presence/absence and abundance with latitude, host sex, and host body condition, and to assess the coexistence and correlation of the abundance between parasite species. Rodents were obtained from 20 localities between 33 and 43°S. Helminths were extracted from the gastrointestinal tract and identified morphologically. Overall, 13 helminth taxa were obtained. The most frequently identified parasite species was Heterakis spumosa, and the most abundant was Syphacia muris, while Physaloptera sp. was the most widely distributed. No locality presented with a coexistence that was different from that expected by chance, while the abundance of five helminthic species correlated with the abundance of another in at least one locality, most likely due to co-infection rather than interaction. Host sex was associated with parasite presence or abundance, and female sex-biased parasitism was notably observed in all cases. Body condition and latitude presented either a positive or negative association with the presence or abundance of parasites depending on the species. It is notable that the likely native Physaloptera sp. is widely distributed among invasive rodents. Further, gravid females were found, suggesting spillback of this species to the native fauna. The low frequency and abundance of highly zoonotic hymenolepid species suggest that rodents are of low concern regarding gastrointestinal zoonotic helminths.
Project description:Male Sprague-Dawley rats were used to establish exhausted-exercise model by motorized rodent treadmill. Yu-Ping-Feng-San at doses of 2.18 g/kg was administrated by gavage before exercise training for 10 consecutive days. Quantitative proteomics was performed for assessing the related mechanism of Yu-Ping-Feng-San.