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Lamin A/C promotes DNA base excision repair (mouse arrays)

ABSTRACT: The A-type lamins (lamin A/C), encoded by the Lmna gene, are important structural components of the nuclear lamina. Lmna mutations lead to degenerative disorders, including the premature aging disease Hutchinson-Gilford progeria syndrome (HGPS). In addition, altered lamin A/C expression is found in various cancers. Reports indicate that lamin A/C plays a role in DNA double strand break repair, but a role in DNA base excision repair (BER) has not been described. We provide evidence for reduced BER efficiency in lamin A/C-depleted cells. The mechanism involves impairment of the APE1 and POLβ enzyme activities in BER. Also, Lmna null mouse fibroblasts displayed reduced expression of several core BER enzymes (PARP1, LIG3, and POLβ). Moreover, the robustness of APE1 and POLβ activities and the rate of BER were enhanced by lamin A/C-augmented poly(ADP-ribose) polymer formation (PARylation). Finally, we report that HGPS fibroblasts are defective in BER. Collectively, our results provide novel insights into the functional interplay between the nuclear lamina and cellular defenses against oxidative DNA damage, with implications for human cancer and aging.

ORGANISM(S): Mus musculus

PROVIDER: GSE120389 | GEO | 2019/10/02

REPOSITORIES: GEO

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Lamin A/C promotes DNA base excision repair (human arrays)

Project description:The A-type lamins (lamin A/C), encoded by the Lmna gene, are important structural components of the nuclear lamina. Lmna mutations lead to degenerative disorders, including the premature aging disease Hutchinson-Gilford progeria syndrome (HGPS). In addition, altered lamin A/C expression is found in various cancers. Reports indicate that lamin A/C plays a role in DNA double strand break repair, but a role in DNA base excision repair (BER) has not been described. We provide evidence for reduced BER efficiency in lamin A/C-depleted cells. The mechanism involves impairment of the APE1 and POLβ enzyme activities in BER. Also, Lmna null mouse fibroblasts displayed reduced expression of several core BER enzymes (PARP1, LIG3, and POLβ). Moreover, the robustness of APE1 and POLβ activities and the rate of BER were enhanced by lamin A/C-augmented poly(ADP-ribose) polymer formation (PARylation). Finally, we report that HGPS fibroblasts are defective in BER. Collectively, our results provide novel insights into the functional interplay between the nuclear lamina and cellular defenses against oxidative DNA damage, with implications for human cancer and aging.

2020-09-30 | GSE124465 | GEO

Transcription profiling of primary fibroblasts from a family with autosomal recessive Hutchinson-Gilford Progeria Syndrome

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.).

2011-06-27 | E-MEXP-3097 | biostudies-arrayexpress

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. ChIP-Seq was performed for H3K27me3 and lamin A/C in the human genome in three primary fibroblast cell lines: an HGPS patient (HGPS), normal cells from the father of the HGPS patient (Father), and age-matched normal cells (Age Control). Two biological replicates were performed.

2012-10-30 | E-GEOD-41757 | biostudies-arrayexpress

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. Hi-C was performed on three primary fibroblast cell lines: an HGPS patient (passage 17 and 19; HGPS), normal cells from the father of the HGPS patient (passage 18; Father), and age-matched normal cells (passage 20; Age Control).

2012-10-30 | E-GEOD-41763 | biostudies-arrayexpress

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.

2012-10-30 | E-GEOD-41751 | biostudies-arrayexpress

Recapitulation of human premature aging by using iPSCs from Hutchinson-Gilford progeria syndrome

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

2011-03-14 | E-GEOD-24487 | biostudies-arrayexpress

2012-10-30 | GSE41751 | GEO

2012-10-30 | GSE41763 | GEO

2012-10-30 | GSE41757 | GEO

Recapitulation of human premature aging by using iPSCs from Hutchinson-Gilford progeria syndrome

2011-03-14 | GSE24487 | GEO