Mesenchymal stem cells derived from patients with premature ageing syndromes display hallmarks of physiological ageing [array]
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ABSTRACT: Progeroid syndromes are rare genetic diseases with a majority of autosomal dominant transmission, the prevalence of which is less than 1 / 10,000,000. These syndromes caused by mutations in the LMNA gene encoding A-type Lamins belong to the group of disorders called laminopathies. Lamins are implicated in the architecture and function of the nucleus and chromatin. Patients affected with progeroid laminopathies display accelerated ageing of mesenchymal stem cells (MSCs)-derived tissues associated with nuclear morphological abnormalities. In order to identify pathways altered in progeroid patients’ MSCs, we used induced pluripotent stem cells (hiPSCs) from patients affected with classical Hutchinson-Gilford Progeria Syndrome (HGPS, c.1824C>T - p.G608G), HGPS-Like Syndrome (HGPS-L; c.1868C>G - p.T623S) associated with farnesylated prelamin A accumulation, or Atypical Progeroid Syndromes (APS; homozygous c.1583C> T - p.T528M; heterozygous c.1762T>C - p.C588R; compound heterozygous c.1583C>T and c.1619T>C - p.T528M and p.M540T) without progerin accumulation. By comparative analysis of the transcriptome and methylome of hiPSC-derived MSCs, we found that patient’s MSCs display specific DNA methylation patterns and modulated transcription at early stages of differentiation. We further explored selected biological processes deregulated in the presence of LMNA variants and confirmed alterations of age-related pathways during MSC differentiation. In particular, we report the presence of an altered mitochondrial pattern, an increased response to double-strand DNA damage and telomere erosion in HGPS, HGPS-L and APS MSCs, suggesting converging pathways, independent of progerin accumulation, but a distinct DNA methylation profile in HGPS and HGPS-L compared to APS cells.
Project description:Progeroid syndromes are rare genetic diseases with a majority of autosomal dominant transmission, the prevalence of which is less than 1 / 10,000,000. These syndromes caused by mutations in the LMNA gene encoding A-type Lamins belong to the group of disorders called laminopathies. Lamins are implicated in the architecture and function of the nucleus and chromatin. Patients affected with progeroid laminopathies display accelerated ageing of mesenchymal stem cells (MSCs)-derived tissues associated with nuclear morphological abnormalities. In order to identify pathways altered in progeroid patients’ MSCs, we used induced pluripotent stem cells (hiPSCs) from patients affected with classical Hutchinson-Gilford Progeria Syndrome (HGPS, c.1824C>T - p.G608G), HGPS-Like Syndrome (HGPS-L; c.1868C>G - p.T623S) associated with farnesylated prelamin A accumulation, or Atypical Progeroid Syndromes (APS; homozygous c.1583C> T - p.T528M; heterozygous c.1762T>C - p.C588R; compound heterozygous c.1583C>T and c.1619T>C - p.T528M and p.M540T) without progerin accumulation. By comparative analysis of the transcriptome and methylome of hiPSC-derived MSCs, we found that patient’s MSCs display specific DNA methylation patterns and modulated transcription at early stages of differentiation. We further explored selected biological processes deregulated in the presence of LMNA variants and confirmed alterations of age-related pathways during MSC differentiation. In particular, we report the presence of an altered mitochondrial pattern, an increased response to double-strand DNA damage and telomere erosion in HGPS, HGPS-L and APS MSCs, suggesting converging pathways, independent of progerin accumulation, but a distinct DNA methylation profile in HGPS and HGPS-L compared to APS cells.
Project description:Hutchinson-Gilford Progeria Syndrome (HGPS) is caused by a point mutation in the LMNA gene that activates a cryptic donor splice site and yields a truncated form of prelamin A called progerin. Small amounts of progerin are also produced during normal aging. Studies with mouse models of HGPS have allowed the recent development of the first therapeutic approaches for this disease. However, none of these earlier works have addressed the aberrant and pathogenic LMNA splicing observed in HGPS patients because of the lack of an appropriate mouse model. We report herein a genetically modified mouse strain that carries the HGPS mutation. These mice accumulate progerin, present histological and transcriptional alterations characteristic of progeroid models, and phenocopy the main clinical manifestations of human HGPS, including shortened life span and bone and cardiovascular aberrations. By using this animal model, we have developed an antisense morpholino–based therapy that prevents the pathogenic Lmna splicing, dramatically reducing the accumulation of progerin and its associated nuclear defects. Treatment of mutant mice with these morpholinos led to a marked amelioration of their progeroid phenotype and substantially extended their life span, supporting the effectiveness of antisense oligonucleotide–based therapies for treating human diseases of accelerated aging. 6 samples, three from LmnaG609G/G609G mice and three from control Lmna+/+ mice
Project description:Hutchinson-Gilford Progeria Syndrome (HGPS) is caused by a point mutation in the LMNA gene that activates a cryptic donor splice site and yields a truncated form of prelamin A called progerin. Small amounts of progerin are also produced during normal aging. Studies with mouse models of HGPS have allowed the recent development of the first therapeutic approaches for this disease. However, none of these earlier works have addressed the aberrant and pathogenic LMNA splicing observed in HGPS patients because of the lack of an appropriate mouse model. We report herein a genetically modified mouse strain that carries the HGPS mutation. These mice accumulate progerin, present histological and transcriptional alterations characteristic of progeroid models, and phenocopy the main clinical manifestations of human HGPS, including shortened life span and bone and cardiovascular aberrations. By using this animal model, we have developed an antisense morpholino–based therapy that prevents the pathogenic Lmna splicing, dramatically reducing the accumulation of progerin and its associated nuclear defects. Treatment of mutant mice with these morpholinos led to a marked amelioration of their progeroid phenotype and substantially extended their life span, supporting the effectiveness of antisense oligonucleotide–based therapies for treating human diseases of accelerated aging.
Project description:Nuclear lamins orchestrate the nuclear envelope architecture to maintain nuclear homeostasis, such as nuclear integrity and chromatin organization. The LMNA mutations lead to a variety of laminopathies, including progeroid syndrome. Other than typical Hutchinson-Gilford progeria syndrome (HGPS), the mechanism of LMNA mutation associated atypical progeria remains largely unexplored. We used patient-specific induced pluripotent stem cells (iPSCs) and their derivatives to remodel an LMNA (c.1579 C>T, p.R527C) mutation that causes Mandibuloacral dysplasia type A (MAD). Vascular lineages, including vascular smooth muscle cells (VSMCs) and endothelial cells (VECs), exhibited premature ageing phenotypes, such as genome instability and nuclear deformations, whereas neural lineages showed no obvious defects. Based on the observation that MAD-iPSCs derived mesenchymal stem cells (MSCs) also recapitulated accelerated senescence, an integrated multi-omics approach was adapted to reveal the underlying mechanisms of stem cells ageing. We found that among available human MSCs ageing models, MAD-MSCs had the highest transcriptional similarity to normal ageing hMSCs. The nuclear lamina-chromatin interaction was dramatically altered for both A and B type lamin-associating domains (LADs) as well as non-LADs binding sites, resulting in ageing-associated gene dysregulations. Chromatin state analysis further showed increased chromatin accessibility, enhancer remodelling, global chromatin compartments loss, topologically associating domains (TADs) and TAD boundaries reorganization in MAD-MSCs. These hierarchical chromatin reorganizations, coupled with gene dysregulation as consequences, expedited the MAD-MSCs ageing. Collectively, this study revealed a multilevel chromatin dysregulation contributed to ageing significantly in a laminopathy-mediated atypical progeroid syndrome.
Project description:Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare disease caused by the expression of progerin, an aberrant protein produced by a de novo point mutation in the LMNA gene. HGPS patients show accelerated aging and die prematurely, mainly from atherosclerosis complications. Understanding vascular disease onset and progression in HGPS and uncovering new therapeutic targets critically depend on the identification of cell type-specific molecular and functional alterations in the highly heterogeneous cell subsets present in the arterial wall. We used single-cell RNA sequencing to characterize the cellular and molecular landscape of the aorta in progerin-expressing LmnaG609G/G609G mice and wild type controls. Subendothelial extracellular matrix (ECM) stiffness was analyzed in decellularized aortas by atomic force microscopy, and aortic blood flow in vivo was monitored by ultrasound assessment. For atherosclerosis studies, we used progeroid atheroprone Apoe–/– LmnaG609G/G609G mice.
Project description:Hutchinson-Gilford Progeria Syndrome (HGPS) is caused by a mutant LMNA called progerin. To determine the mechanism of STXBP5 on progerin, we over expressed STXBP5 or knocked down STXBP5 in HA-progerin HEK293 cells, then analyzed the effect on the expression of coding genes. In this study, we identified STXBP5 as an influencing factor for HA-progerin HEK293 cells. Lowering the expression of STXBP5 may be a new therapeutic strategy for treating age-related phenotypes in HGPS.
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.
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:Mutation on A-type lamins encoding gene can lead to a wide-range of diseases called laminopathies, including dilated cardiomyopathy. Nuclear lamins are integral to a physical continuum connecting the extracellular environment and the nuclear interior, playing a crucial role in load-bearing tissues like the heart to preserve mechanical integrity and genome stability. To investigate the impact of the LMNA p.H222P mutation on gene expression, we conducteed bulk RNA-seq in hiPSCs-derived cardiomyocytes and mouse cardiomyocytes, both carrying this mutation. Our results reveal that the LMNA p.H222P mutation leads to dysregulated gene expression, which may contribute to LMNA cardiomyopathy pathogenesis.
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.