This SuperSeries is composed of the SubSeries listed below.
Neuroprotective effects of brain-derived neurotrophic factor in rodent and primate models of Alzheimer's disease.
Treatment
View SamplesWe examined transgenic (TG) mice expressing human APP695 bearing the double Swedish (671KM>NL) and Indiana (717V>F) amyloid precursor protein (APP) mutations. Lentiviral vectors constitutively expressing BDNF-GFP under control of the CMV/-actin hybrid promoter or GFP alone were injected into the entorhinal cortices of TG mice bilaterally at age 6 months, a time point by which neuropathological degeneration and cell loss are established. Age-matched wild-type littermates underwent sham surgery or injection of lentivirus expressing GFP into the entorhinal cortices bilaterally.
Neuroprotective effects of brain-derived neurotrophic factor in rodent and primate models of Alzheimer's disease.
Treatment
View SamplesTranscriptional control is dependent on a vast network of epigenetic modifications. One epigenetic mark of particular interest is tri-methylation of lysine 27 on histone H3 (H3K27me3), which is catalyzed and maintained by the Polycomb Repressor Complex (PRC2). Although this histone mark is studied widely, the precise relationship between its local pattern of enrichment and regulation of gene expression is currently unclear. We have used ChIP-seq to generate genome wide maps of H3K27me3 enrichment, and have identified three enrichment profiles with distinct regulatory consequences. First, a broad domain of H3K27me3 enrichment across the body of genes corresponds to the canonical view of H3K27me3 as inhibitory to transcription. Second, a peak of enrichment around the transcription start site is commonly associated with bivalent genes, where H3K4me3 also marks the TSS. Finally and most surprisingly, we identified an enrichment profile with a peak in the promoter of genes that is associated with active transcription. Genes with each of these three profiles were found in different proportions in each of the cell types studied. The data analysis techniques developed here will be useful for the identification of common enrichment profiles for other histone modifications that have important consequences for transcriptional regulation.
ChIP-seq analysis reveals distinct H3K27me3 profiles that correlate with transcriptional activity.
Specimen part
View SamplesBackground and Aims: In the interleukin-10-deficient (Il10-/-) mouse model of IBD, 10 quantitative trait loci (QTL) have been shown to be associated with colitis susceptibility by linkage analyses on experimental crosses of highly susceptible C3H/HeJBir (C3Bir)-Il10-/- and partially resistant C57BL/6J (B6)-Il10-/- mice. The strongest locus (C3Bir-derived cytokine deficiency-induced colitis susceptibility [Cdcs]1 on Chromosome [Chr] 3) controlled multiple colitogenic subphenotypes and contributed the vast majority to the phenotypic variance in cecum and colon. This was demonstrated by interval-specific Chr 3 congenic mice wherein defined regions of Cdcs1 from C3Bir or B6 were bred into the IL-10-deficient reciprocal background and altered the susceptible or resistant phenotype. Furthermore, this locus likely acts by inducing innate hypo- and adaptive hyperresponsiveness, associated with impaired NFB responses of macrophages. The aim of the present study was to dissect the complexity of Cdcs1 by further development and characterization of reciprocal Cdcs1 congenic strains and to identify potential candidate genes in the congenic interval. Material and Methods: In total, 15 reciprocal congenic strains were generated from Il10-/- mice of either C3H/HeJBir or C57BL/6J backgrounds by 10 cycles of backcrossing. Colitis activity was monitored by histological grading. Candidate genes were identified by fine mapping of congenic intervals, sequencing, microarray analysis and a high-throughput real-time RT-PCR approach using bone marrow-derived macrophages. Results: Within the originally identified Cdcs1-interval, three independent regions were detected that likely contain susceptibility-determining genetic factors (Cdcs1.1, Cdcs1.2, and Cdcs1.3). Combining results of candidate gene approaches revealed Fcgr1, Cnn3, Larp7, and Alpk1 as highly attractive candidate genes with polymorphisms in coding or regulatory regions and expression differences between susceptible and resistant mouse strains. Conclusions: Subcongenic analysis of the major susceptibility locus Cdcs1 on mouse chromosome 3 revealed a complex genetic structure. Candidate gene approaches revealed attractive genes within the identified regions with homologs that are located in human susceptibility regions for IBD.
Cdcs1 a major colitis susceptibility locus in mice; subcongenic analysis reveals genetic complexity.
Sex, Specimen part
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