Project description:An inversion polymorphism at the 17q21.31 locus defines the H1 and H2 haplotypes, with the former linked to multiple neurodegenerative disorders, including an increased risk of Parkinson’s disease (PD). Although the high linkage disequilibrium at this locus has made it difficult to decipher which gene(s) drive the PD association, there is increasing evidence to support the role of KANSL1 as a risk gene. KANSL1 has been shown to regulate the expression of some PD-associated genes and pathways, likely as part of the histone acetylating non-specific lethal (NSL) complex. Here for the first time, we studied the global effects of 17q21.31 haplotype variation using bulk and single-nuclear RNA-sequencing data from control and PD patient brain. We first analysed differential gene expression across haplotype groups, and then assessed the contribution of KANSL1 by comparing with the results of an siRNA knockdown in neuronal and glial human cell lines. We demonstrated that the PD risk-associated H1 haplotype downregulates autophagy, lysosomal and mitochondrial processes, all of which have already been implicated in PD aetiology. Furthermore, these effects were apparent in both neuronal and glial cell types, and in the case of the latter, appear to be associated with the modulation of innate and adaptive immune responses. Thus, we identify important links between NSL complex activity and PD pathophysiology that can be leveraged for novel therapeutic interventions.
Project description:This is array CGH data of recurrent 17q21.31 deletions used to delineate breakpoints within segmental duplications in a study by Itsara et al. Somatic cell hybrids were generated from three parent-child trios probands with 17q21.31 deletions and three 17q21.31 probands for which no parental DNA was available that isolated individual chromosome 17 homologues. In parents, this isolated the H2 from the H1 haplotypes in distinct cell lines, and in probands, isolated the deletion-bearing chromosomes from the unaffected chromosome 17. In parent-child trios, the deletion-bearing chromosomes were hybridized against the progenitor parental chromosome. In probands with no parental DNA, the deletion-bearing chromosomes were hybridized against an H2 chromosome. 6 experimental hybes of deletion-bearing proband vs H2 chromosome reference. 3 control hybes of H1 vs H2 haplotype, H2 vs H2 haplotype (different individuals), and H1 vs deletion-bearing H2 haplotype.
Project description:Progressive supranuclear palsy (PSP) and frontotemporal dementia (FTD) are two neurodegenerative diseases linked, at the pathologic and genetic level, to the macrutubule associated protein tau. We identified and replicated a dose-dependent effect of the risk-associated H1 haplotype on methylation levels within the region in independent datasets in blood and brain. These data reveal that the H1 haplotype increases risk for tauopathy via differential methylation, indicating a mediating role for methylation in dementia pathophysiology.
Project description:Progressive supranuclear palsy (PSP) and frontotemporal dementia (FTD) are two neurodegenerative diseases linked, at the pathologic and genetic level, to the macrutubule associated protein tau. We identified and replicated a dose-dependent effect of the risk-associated H1 haplotype on methylation levels within the region in independent datasets in blood and brain. These data reveal that the H1 haplotype increases risk for tauopathy via differential methylation, indicating a mediating role for methylation in dementia pathophysiology. We studied epigenetic changes (DNA methylation levels) in peripheral blood from patients with PSP, FTD, and unaffected controls. Analysis of genome-wide methylation patterns revealed significant differentially methylated probes in patients versus unaffected controls.
Project description:The 9p21.3 cardiovascular disease locus is the most influential common genetic risk factor for coronary artery disease, accounting for ~10-15% of disease among non-African populations. The ~60kb risk haplotype is human-specific and lacks coding genes, hindering efforts to decipher its function. Genetic studies implicate the 9p21.3 locus and other risk genes to effects in the vascular wall. Here, we use genome editing to delete the entire risk on non-risk haplotype from the genomes of human iPSCs and perform genomewide transcriptional profiling along the timecourse of their differentiation into vascular smooth muscle cells (VSMCs). These studies identify a network of ~3000 genes governed by the risk haplotype in VSMCs that predict deficits in cell division, adhesion and contraction, which we confirmufunctionally. Remarkably, deleting the risk haplotype reverts VSMCs to resemble the non-risk VSMCs, suggesting that the risk region drives a cell state transition. transcriptionally and functionally. . Deleting the risk haplotype reverts these cells to reverted to the non-risk of iPSCs we show that the non-risk haplotype has little effect on locus we produce iPSCs from risk and non-risk individuals, delete each haplotype using genome editing and generate vascular smooth muscle cells (VSMCs). We show that risk VSMCs exhibit aberrant adhesion and contraction, concomitant with dramatically altered global transcriptional changes that are enriched in previously identified cardiovascular disease genes and pathways. Unexpectedly, deleting the risk haplotype rescues VSMC transcriptional identity and function, while expressing the 9p21.3-associated long non-coding RNA ANRIL induces risk phenotypes in non-risk VSMCs. This studies shows that the risk haplotype dominantly predisposes VSMCs to adopt perturbed phenotypes associated with cardiovascular disease and establishes haplotype-edited iPSCs as powerful tools for functionally annotating human-specific variation in non-coding genomic regions.
Project description:Whole transcriptome RNA-seq analysis to measure group-wise RNA expression level of the MERTK gene in 3 healthy controls (known to be homozygous non-risk haplotype at MERTK gene locus) and to compare this to the group-wise RNA expression level of the MERTK gene in 5 Multiple Sclerosis-affected (MS-affected) individuals (known to be homozygous for the MS risk haplotype at the MERTK gene locus). We sequenced the whole transcriptome of 3 healthy control samples which were all homozygous for the MS non-risk haplotype at the MERTK gene. We also did the same RNA-seq protocol on 5 MS-affected subjects that were all homozygous for the Risk haplotype at the MERTK gene. All 8 samples were sequenced evenly across 3 lanes of an Illumina HiSeq NGS machine to remove any batch-type effects that could be caused by sequencing e.g. all cases in one lane and all controls in another lane.
Project description:Whole transcriptome RNA-seq analysis to measure group-wise RNA expression level of the MERTK gene in 3 healthy controls (known to be homozygous non-risk haplotype at MERTK gene locus) and to compare this to the group-wise RNA expression level of the MERTK gene in 5 Multiple Sclerosis-affected (MS-affected) individuals (known to be homozygous for the MS risk haplotype at the MERTK gene locus).
Project description:This is array CGH data of recurrent 17q21.31 deletions used to delineate breakpoints within segmental duplications in a study by Itsara et al. Somatic cell hybrids were generated from three parent-child trios probands with 17q21.31 deletions and three 17q21.31 probands for which no parental DNA was available that isolated individual chromosome 17 homologues. In parents, this isolated the H2 from the H1 haplotypes in distinct cell lines, and in probands, isolated the deletion-bearing chromosomes from the unaffected chromosome 17. In parent-child trios, the deletion-bearing chromosomes were hybridized against the progenitor parental chromosome. In probands with no parental DNA, the deletion-bearing chromosomes were hybridized against an H2 chromosome.
Project description:Genome-wide association studies in multiple sclerosis (MS) identified a polymorphism (rs6897932) located in the coding region of the alpha chain of the cytokine receptor interleukin 7 receptor (IL7R) as a component that increases susceptibility to develop the disease. This single nucleotide polymorphism (SNP) affects the splicing of the primary transcript leading to genotype-defined transcript ratios encoding either a full length membrane spanning form or a soluble receptor chain. Genotyping at the IL7R locus reveals that the region can be described by four haplotypes. Interestingly, only one out of three haplotypes harbouring the associated SNP is positively associated with MS whereas the other two do not show association. The minor allele containing haplotype shows a reduced susceptibility to develop MS. We hypothesized that additional functional or phenotypic differences exist between individuals homozygous for haplotypes shown to have either positive, negative, or neutral effect, on susceptibility to develop MS. Gene expression profiles of CD4+ T cells from MS individuals before and after stimulation with IL7 were recorded. Haplotype-specific gene signatures were found indicating small alterations in IL7/IL7R signal processing/sensitivity through JAK/STAT and p38/MAPK14. We can not exclude that the obtained signatures result from differences within the CD4+ T cell compartment that, in fact, should be seen as a consequence of systemic haplotype-specific processing of homeostatic and proliferation signals transmitted through IL7/IL7R. Samples of CD4+ cells were obtained from 7 MS patients (homozygous for Hap1 (3), Hap2 (2), Hap3 (2)). CD4+ cells were collected from peripheral blood, frozen and stored in liquid nitrogen. All samples were thawed and CD4+ cells were purified by magnetic bead separation. Purity and viability of cells was analyzed by Fluorescence Activated Cell Sorter (FACS). Total cellular RNA were extracted with TRIzol reagent and analyzed with the Human Gene 1.0 ST Array (affymetrix). IL7R haplotypes and susceptibility to develop MS: Hap1 homozygous <-> Risk <-> positive effect on MS susceptibility Hap2 homozygous <-> Hap2 <-> neutral effect on MS susceptibility Hap3 homozygous <-> Prot <-> neutral effect on MS susceptibility [Note: Haplotype nomenclature subject to revision.]
Project description:ChIP-sequencing for H3K4me1, H3K4me3, and H3K27ac was performed in primary human hepatocytes from three individuals heterozygous for the T2D risk haplotype at the SLC16A11 locus. The goal was to identify allelic skews in chromatin marks at variants at the SLC16A11 locus.