Project description:An Infinium microarray platform (GPL23976, Illumina Infinium HumanMethylation850 BeadChip) was used to generate DNA methylation data from fibroblasts from human progeria cases. Treatment: Antisense oligonucleotide for Line 1 elements.
Project description:<p>Deep sequencing was performed to analyze the prevalence of somatic mutations during <i>in vitro</i> cell aging. Primary dermal fibroblasts from healthy subjects of young and advanced age, from Hutchinson-Gilford progeria syndrome, and from Xeroderma Pigmentosum complementation group A (XPA) and C (XPC), were first restricted in number and then expanded <i>in vitro</i>. DNA was obtained from cells pre- and post-expansion and sequenced at high depth, over a cumulative 290 kb target region, including the exons of 44 aging-related genes. Allele frequencies of 58 somatic mutations differed between the pre- and post-cell culture expansion passages.</p>
Project description:Hutchinson Gilford Progeria Syndrome (HGPS) is a rare, sporadic genetic disease caused by mutations in the nuclear lamin A gene. In most cases the mutation creates an efficient donor-splice site that generates an altered transcript encoding a truncated lamin A protein, progerin. In vitro studies have indicated that progerin can disrupt nuclear function. HGPS affects mainly mesenchymal lineages but the shortage of patient material has precluded a tissue-wide molecular survey of progerin’s cellular impact. We report here a new, induced pluripotent stem cell (iPSC)-based model for studying HGPS. HGPS dermal fibroblasts were reprogrammed into iPSC lines using a cocktail of the transcription factor genes, OCT4, SOX2, KLF4 and C-MYC. The iPSC cells were differentiated into neural progenitors (NPs), endothelial cells (ECs), fibroblast-like cells and mesenchymal stem cells (MSCs). Progerin levels in the different cell types followed the pattern MSC≥ fibroblast>EC>>NP. Functionally, we detected a major impact of progerin on MSC function. We show that HGPS-MSCs are vulnerable to the ischemic conditions found in a murine hind limb recovery model and an in vitro hypoxia assay, as well as showing enhanced sensitivity in a serum starvation assay. Since there is widespread consensus that MSCs reside in low oxygen niches in vivo, we propose that these conditions lead to an accelerated depletion of the MSC pool in HGPS patients with consequent accretion of mesenchymal tissue. Analysis of iPSCs, hESCs and parental fibroblasts at the gene expression level. The comparison analysis in the present study was expected to show the similarity between iPSCs, hESCs and parental fibroblasts. Results provide important information of the differences between iPSCs, hESCs and parental fibroblasts. Total RNA was obtained from different samples (iPSCs, hESCs, and fibroblasts) separately.
Project description:Progeria syndromes are very rare, incurable premature aging conditions recapitulating most aging features. Through a whole genome, multiparametric CRISPR anti-aging screen,we identified 43 new genes that can reverse multiple aging phenotypes in progeria. The screen was implemented in fibroblasts from Néstor-Guillermo Progeria Syndrome (NGPS) patients, carrying a homozygous p.Ala12Thr mutation in barrier-to-autointegration factor (BAF A12T). The hits were enriched for genes involved in protein synthesis, protein and RNA transport and osteoclast formation. We further confirmed that BAF A12T drives increased protein translation and translational errors that could directly contribute to premature aging in patients. This RNA seq analysis identified 213 genes as being differentially expressed in NGPS cells compared to WT cells. GO analysis showed enrichment for genes involved in translation, supporting that the BAF A12T mutation modulates the expression of genes regulating translation
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:We present a new high-throughput sequencing-based technique, named Sequential Analysis of MacroMolecules accessibilitY (SAMMY-seq), for the genome-wide mapping of chromatin regions separated by differential accessibility. The method is based on the sequential extraction of multiple chromatin fractions, corresponding to increasingly compacted and less accessible chromatin regions, which are mapped along the genome using high-throughput sequencing. Using SAMMY-seq we analyzed Hutchinson-Gilford progeria syndrome (HGPS) skin fibroblasts and normal control fibroblasts. Additionally we carried out ChIP-seq for the H3K9me3 and H3K27me3 histone modifications and RNA-seq for the characterization of transcriptome changes on the same HGPS and control fibroblasts.
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 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:Exon usage analysis in in vitro cultured fibroblast cells. To assay the genome-wide splicing changes during cellular senescence, we performed splicing analysis on young and old normal fibroblasts, and in fibroblasts +/- tert (telomerase protein subunit Tert immortalized). We analyzed primary fibroblasts from 5 healthy subjects at various passages and from 2 Hutchinson-Gilford Progeria Syndrome (HGPS) patients using the Affymetrix Human Exon 1.0 ST platform. Two or three technical replicates were performed.