Project description:This SuperSeries is composed of the following subset Series: GSE41751: Correlated alterations in genome organization, histone methylation, and DNA-lamina interactions in Hutchinson-Gilford progeria syndrome (expression) GSE41757: Correlated alterations in genome organization, histone methylation, and DNA-lamina interactions in Hutchinson-Gilford progeria syndrome (ChIP-seq) GSE41763: Correlated alterations in genome organization, histone methylation, and DNA-lamina interactions in Hutchinson-Gilford progeria syndrome (Hi-C) Refer to individual Series
Project description:The main goal of this study was to gain insight into the mechanisms underlying phenotypic changes in endothelial cells during atherosclerosis associated with Hutchinson-Gilford progeria syndrome, a premature aging syndrome. To this end, we performed an RNAseq experiment with aortic intima samples from atheroprone mice with ubiquitous and VSMC-specific progeria expression and their corresponding controls.
Project description:Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal human premature aging disease1-5, characterized by premature atherosclerosis and degeneration of vascular smooth muscle cells (SMCs)6-8. HGPS is caused by a single-point mutation in the LMNA gene, resulting in the generation of progerin, a truncated mutant of lamin A. Accumulation of progerin leads to various aging-associated nuclear defects including disorganization of nuclear lamina and loss of heterochromatin9-12. Here, we report the generation of induced pluripotent stem cells (iPSCs) from fibroblasts obtained from patients with HGPS. HGPS-iPSCs show absence of progerin, and more importantly, lack the nuclear envelope and epigenetic alterations normally associated with premature aging. Upon differentiation of HGPS-iPSCs, progerin and its associated aging consequences are restored. In particular, directed differentiation of HGPS-iPSCs to SMCs leads to the appearance of premature senescent SMC phenotypes associated with vascular aging. Additionally, our studies identify DNA-dependent protein kinase catalytic subunit (DNAPKcs) as a component of the progerin-containing protein complex. The absence of nuclear DNAPKcs correlates with premature as well as physiological aging. Since progerin also accumulates during physiological aging6,12,13, our results provide an in vitro iPSC-based model with an acceleration progerin accumulation to study the pathogenesis of human premature and physiological vascular aging. Microarray gene expression profiling was done to: (1) Compare differences between WT fibroblasts and fibroblasts from patients suffering of the Hutchinson-Gilford progeria syndrome (2) Check that iPSC originating from WT and patients are in fact similar to ESC
Project description:Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disease that is frequently caused by a de novo point mutation at position 1824 in LMNA. This mutation activates a cryptic splice donor site in exon 11, and leads to an in-frame deletion within the prelamin A mRNA and the production of a dominant negative lamin A protein, known as progerin. Here we show that HGPS cells experience genome-wide alterations in patterns of H3K27me3 deposition, changes in the associations of genomic loci with nuclear lamin A/C, and, at late passages, genome-wide loss of spatial compartmentalization of active and inactive chromatin domains that characterizes chromosome folding in normal cells. We further demonstrate that the H3K27me3 changes associate with gene expression alterations in HGPS cells. Our results support a model that the accumulation of progerin in the nuclear lamina leads to altered H3K27me3 marks in heterochromatin, possibly through the down-regulation of EZH2, and disrupts heterochromatin-lamina interactions. These changes may then lead to the genomic disorganization and changes in transcriptional regulation we observe in HGPS fibroblasts. We analyzed gene expression of primary fibroblasts of a Hutchinson-Gilford progeria syndrome patient, a healthy age-matched control, and the patient's healthy father using the Affymetrix GeneChip Human Genome U133 Plus 2.0 Array platform. Arrays were filtered and normalized using RMA. Two replicates were performed.
Project description:Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare lethal genetic disorder characterized with symptoms reminiscent of accelerated aging. The major underlying genetic cause is a substitution mutation in the gene coding for lamin A, causing the production of a toxic isoform called progerin. Here we show the RNA sequencing analyses performed on primary mouse fibroblasts of different genotypes (in terms of Progeria; Cas9 background) treated with Cas9 guide RNAs targeting Lmna/Progerin. The mouse genetic background in (1) Pro/Pro;Cas9/+: homozygous for Progeria and heterozygous for transgenic Cas9 The mouse genetic background in (2) Pro/+; +/+: heterozygous for Progeria and no transgenic Cas9 (wild type) The mouse genetic background in (3) +/+;Cas9/+: no Progeria (wild type) and heterozygous for transgenic Cas9
Project description:Hutchinson-Gilford Progeria Syndrome (HGPS) is a progeroid disease characterized by the early onset of some classically age-related phenotypes including arthritis, loss of body fat and hair and atherosclerosis. Cells from affected individuals express a mutant version of the nuclear envelope protein Lamin A (termed Progerin) and have previously been shown to exhibit prominent chromatin changes. Here, we identify epigenetic deregulation of lamina-associated domains (LADs) as a central feature in the molecular pathology of HGPS. Using ATAC-see/-seq and Infinium MethylationEPIC BeadChip-mediated DNA methylation profiling, we demonstrate that dermal fibroblasts from HGPS patients exhibit both chromatin accessibility and DNA methylation changes that are enriched in LADs. Importantly, we further show that these epigenetic alterations are associated with HGPS-specific gene expression changes. Together, our results establish a central involvement of LADs in the epigenetic deregulation of HGPS and provide novel insight into the molecular changes associated with the disease.
Project description:Our goal was to identify gene expression and functional differences between directly reprogrammed vascular cells derived from young and old individuals, as wells as from healthy and Hutchinson-Gilford Progeria Syndrome (HGPS) donors. We provided a full characterization of reprogrammed endothelial and smooth muscle cells by comparing their gene expression with both the original fibroblasts and primary vascular cells, showing that reprogrammed cells express key vascular cell-identity genes and contribute to the formation of in vitro 3D vascular structures. We identified and validated biomarkers of vascular dysfunction in the context of physiological and accelerated aging typical of HGPS patients, and we demonstrated their direct contribution in the modulation of vascular permeability.
Project description:Hutchinson–Gilford progeria syndrome (HGPS) is a rare genetic disease with widespread phenotypic features resembling premature aging. HGPS was recently shown to be caused by dominant mutations in the LMNA gene, resulting in the in-frame deletion of 50 amino acids near the carboxyl terminus of the encoded lamin A protein. Children with this disease typically succumb to myocardial infarction or stroke caused by severe atherosclerosis at an average age of 13 years. To elucidate further the molecular pathogenesis of this disease, we compared the gene expression patterns of three HGPS fibroblast cell lines heterozygous for the LMNA mutation with three normal, age-matched cell lines. We defined a set of 361 genes (1.1% of the approximately 33 000 genes analyzed) that showed at least a 2-fold, statistically significant change. The most prominent categories encode transcription factors and extracellular matrix proteins, many of which are known to function in the tissues severely affected in HGPS. The most affected gene, MEOX2/GAX, is a homeobox transcription factor implicated as a negative regulator of mesodermal tissue proliferation. Thus, at the gene expression level, HGPS shows the hallmarks of a developmental disorder affecting mesodermal and mesenchymal cell lineages. The identification of a large number of genes implicated in atherosclerosis is especially valuable, because it provides clues to pathological processes that can now be investigated in HGPS patients or animal models. Keywords: microarrays, Hutchinson–Gilford progeria syndrome, HGPS
Project description:Hutchinson-Gilford progeria syndrome (HGPS) is a genetic disorder displaying features reminiscent of premature senescence caused by germline mutations in the LMNA gene encoding lamin A and C, essential components of the nuclear lamina. By studying a family with homozygous LMNA mutation (K542N), we showed that HGPS can also be caused by mutations affecting both isoforms, lamin A and C (J Med Genet 2004;41:609M-^V614). With the aim to elucidate the molecular mechanisms underlying the pathogenesis of lamin A/C-related (hereditary) HGPS, we investigated primary cultured skin fibroblasts from affected homozygous K542N carriers (n=3), healthy heterozygotes (n=3), and controls (n=3) for differences in global gene expression using GeneChip Human Genome U133 Plus 2.0 arrays (Affymetrix UK Ltd.).
Project description:Hutchinson-Gilford Progeria Syndrome (HGPS) is a segmental premature aging disorder caused by the accumulation of the truncated form of Lamin A known as Progerin within the nuclear lamina. Cellular hallmarks of HGPS include nuclear blebbing, loss of peripheral heterochromatin, defective epigenetic inheritance, altered gene expression, and senescence. To model HGPS using iPSCs, detailed genome-wide and structural analysis of the epigenetic landscape is required to assess the initiation and progression of the disease.