Multiple DNA repair pathways collectively protect against DNA damage-induced replicative aging.
Ontology highlight
ABSTRACT:
ORGANISM(S): Caenorhabditis elegans
SUBMITTER: Jessica Lindvall
PROVIDER: E-GEOD-39145 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:We demonstrate that transcriptomic profiling of the NER mutant ercc-1 offers better understanding of the complex phenotypes of ercc-1 deficiency in C. elegans, as it does in mammalian models. There is a transcriptomic shift in ercc-1 mutants that suggests a stochastic impairment of growth and development, with a shift towards a higher proportion of males in the population. Extensive phenotypic analyses confirm that NER deficiency in C. elegans leads to severe developmental and growth defects and a reduced replicative lifespan, although post-mitotic lifespan is not affected. Results suggest that these defects are caused by an inability to cope with randomly occurring DNA damage, which may interfere with transcription and replication. The study investigates the developmental and aging phenotypes of different NER deficient C. elegans mutants (xpa-1, ercc-1, xpf-1 and xpg-1), where the transcriptomic profile of ercc-1 mutant is presented. We show that loss of NER function does not affect post-mitotic lifespan, but leads to impaired embryogenesis, germ cell and larval development and causes a reduced replicative lifespan. Phenotypes are most pronounced in ercc-1, xpf-1 and xpg-1 mutant animals. We provide evidence that this more pronounced phenotype is likely caused by the fact that these genes are involved in multiple repair pathways besides NER. Furthermore, transcriptional profiling of ercc-1 mutants confirms these observations, showing that growth and developmental pathways are underrepresented but that insulin signaling is not affected. Our analysis suggests that XPA-1, ERCC-1, XPF-1 and XPG-1 protect animals against replicative aging by preventing the accumulation of randomly acquired DNA damage.
2013-09-15 | GSE39145 | GEO
Project description:Background: The ability of an organism to repair DNA damage is implicated in carcinogenesis and aging. Interestingly expression profiling of Nucleotide Excision Repair (NER) deficient segmental progeroid mice revealed gene expression changes resembling these observed in aged wild type animals. Our previous transcriptional profiling of NER-deficient C. elegans xpa-1 mutant showed overrepresentation of genes involved in lifespan determination and upregulation of several oxidative stress response genes (Fensgard et al. Aging 2010). However, since an independent study performed by Boyd and coworkers (Boyd et al. Mut Res 2010) showed limited number of changes in xpa-1 mutant. Therefore to independently validate that transcriptome modulation does take place in xpa-1 mutants, we performed another global gene expression profiling based on 5 independent biological replicates allowing more stringent statistical analysis. Results: In agreement with what was observed by Boyd and coworkers (Boyd et al. Mut Res 2010) current transcriptomic analysis detected fewer changes in xpa-1 C. elegans mutant with only a few genes regulated more than 4-fold. Nevertheless, Gene Ontology (GO) enrichment analysis performed on statistically significantly regulated unique protein coding genes revealed overrepresentation of aging gene cluster. Moreover, as before, overexpression of several genes involved in oxidative stress responses was detected. Conclusion: More stringent statistical analysis predictably resulted in a smaller number of regulated genes and thus overrepresented GOs comparing to the earlier paper. However, major conclusions of the previous study can be still regarded as valid, as the most important aging GO is still overrepresented. Background: The ability of an organism to repair DNA damage is implicated in carcinogenesis and aging. Interestingly expression profiling of Nucleotide Excision Repair (NER) deficient segmental progeroid mice revealed gene expression changes resembling these observed in aged wild type animals. Our previous transcriptional profiling of NER-deficient C. elegans xpa-1 mutant showed overrepresentation of genes involved in lifespan determination and upregulation of several oxidative stress response genes (Fensgard et al. Aging 2010). However, since an independent study performed by Boyd and coworkers (Boyd et al. Mut Res 2010) showed limited number of changes in xpa-1 mutant. Therefore to independently validate that transcriptome modulation does take place in xpa-1 mutants, we performed another global gene expression profiling based on 5 independent biological replicates allowing more stringent statistical analysis. Results: In agreement with what was observed by Boyd and coworkers (Boyd et al. Mut Res 2010) current transcriptomic analysis detected fewer changes in xpa-1 C. elegans mutant with only a few genes regulated more than 4-fold. Nevertheless, Gene Ontology (GO) enrichment analysis performed on statistically significantly regulated unique protein coding genes revealed overrepresentation of aging gene cluster. Moreover, as before, overexpression of several genes involved in oxidative stress responses was detected. Conclusion: More stringent statistical analysis predictably resulted in a smaller number of regulated genes and thus overrepresented GOs comparing to the earlier paper. However, major conclusions of the previous study can be still regarded as valid, as the most important aging GO is still overrepresented. Background: The ability of an organism to repair DNA damage is implicated in carcinogenesis and aging. Interestingly expression profiling of Nucleotide Excision Repair (NER) deficient segmental progeroid mice revealed gene expression changes resembling these observed in aged wild type animals. Our previous transcriptional profiling of NER-deficient C. elegans xpa-1 mutant showed overrepresentation of genes involved in lifespan determination and upregulation of several oxidative stress response genes (Fensgard et al. Aging 2010). However, since an independent study performed by Boyd and coworkers (Boyd et al. Mut Res 2010) showed limited number of changes in xpa-1 mutant. Therefore to independently validate that transcriptome modulation does take place in xpa-1 mutants, we performed another global gene expression profiling based on 5 independent biological replicates allowing more stringent statistical analysis. Results: In agreement with what was observed by Boyd and coworkers (Boyd et al. Mut Res 2010) current transcriptomic analysis detected fewer changes in xpa-1 C. elegans mutant with only a few genes regulated more than 4-fold. Nevertheless, Gene Ontology (GO) enrichment analysis performed on statistically significantly regulated unique protein coding genes revealed overrepresentation of aging gene cluster. Moreover, as before, overexpression of several genes involved in oxidative stress responses was detected. Conclusion: More stringent statistical analysis predictably resulted in a smaller number of regulated genes and thus overrepresented GOs comparing to the earlier paper. However, major conclusions of the previous study can be still regarded as valid, as the most important aging GO is still overrepresented. Activation of oxidative stress-responses and downregulation of insulin-like signaling (ILS) is seen in Nucleotide Excision Repair (NER) deficient segmental progeroid mice. Evidence suggests that this is a survival response to persistent transcription-blocking DNA damage, although the relevant lesions have not been identified. Here we provide evidence for transcriptional reprogramming in NER-deficient C. elegans xpa-1 by transcriptomic and proteomic approaches. This reprograming is accompanied by increased intracellular ROS and ATP levels and lifespan shortening in xpa-1 mutant. Moreover we show that Base Excision Repair DNA glycosylase NTH-1 is upstream form the signaling events leading to transcriptomic changes, as its downregulation reverses overexpression of sod-3, gst-4 and aqp-1 genes, reduces intracellular ROS and ATP levels and reverses lifespan shortening observed in xpa-1 mutant. Surprisingly, however, these responses appear to not depend on cyclopurine levels, since these lesions are lower in xpa-1 C. elegans mutant than in the wild type. Finally, we also explore here which other upstream factors are necessary for transcriptional reprograming in xpa-1 mutant. Untreated Caenorhabditis elegans mutant deficient in xpa-1 and the wild type N2 strain were subjected to transcriptome analysis using Affymetrix platform. For each sample group five replicates were analyzed.
2013-05-03 | E-GEOD-39252 | biostudies-arrayexpress
Project description:Background: The ability of an organism to repair DNA damage is implicated in carcinogenesis and aging. Interestingly expression profiling of Nucleotide Excision Repair (NER) deficient segmental progeroid mice revealed gene expression changes resembling these observed in aged wild type animals. Our previous transcriptional profiling of NER-deficient C. elegans xpa-1 mutant showed overrepresentation of genes involved in lifespan determination and upregulation of several oxidative stress response genes (Fensgard et al. Aging 2010). However, since an independent study performed by Boyd and coworkers (Boyd et al. Mut Res 2010) showed limited number of changes in xpa-1 mutant. Therefore to independently validate that transcriptome modulation does take place in xpa-1 mutants, we performed another global gene expression profiling based on 5 independent biological replicates allowing more stringent statistical analysis. Results: In agreement with what was observed by Boyd and coworkers (Boyd et al. Mut Res 2010) current transcriptomic analysis detected fewer changes in xpa-1 C. elegans mutant with only a few genes regulated more than 4-fold. Nevertheless, Gene Ontology (GO) enrichment analysis performed on statistically significantly regulated unique protein coding genes revealed overrepresentation of aging gene cluster. Moreover, as before, overexpression of several genes involved in oxidative stress responses was detected. Conclusion: More stringent statistical analysis predictably resulted in a smaller number of regulated genes and thus overrepresented GOs comparing to the earlier paper. However, major conclusions of the previous study can be still regarded as valid, as the most important aging GO is still overrepresented. Activation of oxidative stress-responses and downregulation of insulin-like signaling (ILS) is seen in Nucleotide Excision Repair (NER) deficient segmental progeroid mice. Evidence suggests that this is a survival response to persistent transcription-blocking DNA damage, although the relevant lesions have not been identified. Here we provide evidence for transcriptional reprogramming in NER-deficient C. elegans xpa-1 by transcriptomic and proteomic approaches. This reprograming is accompanied by increased intracellular ROS and ATP levels and lifespan shortening in xpa-1 mutant. Moreover we show that Base Excision Repair DNA glycosylase NTH-1 is upstream form the signaling events leading to transcriptomic changes, as its downregulation reverses overexpression of sod-3, gst-4 and aqp-1 genes, reduces intracellular ROS and ATP levels and reverses lifespan shortening observed in xpa-1 mutant. Surprisingly, however, these responses appear to not depend on cyclopurine levels, since these lesions are lower in xpa-1 C. elegans mutant than in the wild type. Finally, we also explore here which other upstream factors are necessary for transcriptional reprograming in xpa-1 mutant.
2013-05-03 | GSE39252 | GEO
Project description:The ERCC1-XPF heterodimer is a multifunctional endonuclease involved in nucleotide excision repair (NER), inter-strand crosslink (ICL) repair, and DNA double-strand break (DSB) repair. Only two patients with inherited ERCC1 defects have been reported who both died at an early age. Here, we describe a new case of ERCC1 deficiency in two siblings (11 and 13 years) who show mild features of Xeroderma Pigmentosum and Cockayne Syndrome. Both patients displayed microcephaly, mild developmental delay, mild photosensitivity, and severe cholestatic liver problems. Genetic analysis revealed a maternal deletion and a paternal missense variant in ERCC1 (R156W) that affect a salt bridge just below the XPA-binding pocket. Studies in patient-derived fibroblasts and reconstituted knockout cells confirmed that mutant ERCC1 is not efficiently recruited to the NER complex due to a decreased interaction with XPA. Consequently, patient cells show a strong NER defect, although residual repair could be detected. The steady-state protein levels of ERCC1 and XPF were severely reduced in patient cells, but this only led to a mild defect in ICL repair, and no impact on DSB repair. We report a new case of ERCC1 deficiency that particularly affect NER and has only a mild impact on other ERCC1-dependent repair pathways.
2021-01-26 | PXD017940 | Pride
Project description:XPA is a central scaffold protein in nucleotide excision repair (NER) that interacts with and coordinates the assembly of repair complexes. Inactivating mutations in XPA causes Xeroderma Pigmentosum (XP), which is characterized by extreme UV sensitivity and a highly elevated skin cancer risk. Here, we describe two Dutch siblings in their late forties carrying a homozygous H244R substitution in the C-terminus of XPA with a mild manifestation of XP without skin cancer, but with neurological features including cerebellar ataxia. We show that the mutant XPA protein shows a severely weakened interaction with the TFIIH complex leading to its inefficient association with NER complexes and an inability to support the efficient association of the ERCC1-XPF endonuclease with repair complexes. Despite these defects, we find that patient-derived fibroblasts and reconstituted knockout cells carrying the H244R substitution show considerable levels of residual global genome repair (~40%), which is in intrinsic property of the mutated protein as revealed by in vitro experiments. In contrast, patient fibroblasts and engineered cells only expressing the mutant XPA protein were fully deficient in transcription-coupled repair. We report a new case of XPA deficiency that interferes with TFIIH binding and primarily affects the transcription-coupled sub-pathway of nucleotide excision repair, which is more closely associated with neurological features than to skin abnormalities.
2023-02-19 | PXD033520 | Pride
Project description:We utilized high-throughput RNA-seq to uncover the intermediate-sized noncoding RNAs invovled in UV-DNA Damage Responses in C. elegans. 450 novel transfrags were discovered, some of which show dramatic expression change between the UV irradiation and control. This study should lead to a better understanding of the role of is-ncRNAs invovled in UV-DDR. Examination of intermediate-sized transcripts (70-500nt) in L4 larvae of C. elegans strains, including wild-type (N2), UV-irradiated (N2-UV100J/m2) and NER-deficient mutant (xpa-1) strains.
2012-05-01 | E-GEOD-37063 | biostudies-arrayexpress
Project description:Background: The ability of an organism to repair damages to DNA is inextricably linked to aging and cancer. We have characterized and compared the transcriptome of C. elegans mutants deficient in DNA base excision repair, nucleotide excision repair or both to elucidate the transcriptional changes incurred by the reduction of these repair pathways. Results: The gene expression signatures from nth-1, xpa-1 and nth-1;xpa-1 are deciphered. We find that the single mutants are more similar in overall transcriptomic activity compared to the double mutant and their corresponding wild-type (N2). Interestingly, of the enriched Gene Ontology terms for respective mutants are aging and proteolysis for nth-1, aging, energy production and unfolded protein response for xpa-1, and DNA repair and regulation of M-phase for nth-1;xpa-1. We also find striking similarities between the biological processes found to be enriched in the single mutants, which show a shared response in genes associated with aging and insulin signaling. Loss of either BER or NER induces an oxidative stress response, but does not confer resistance to heat shock. Conclusion: Taken together, our study provides a general overview about the global transcriptional changes in the absence of nth-1, xpa-1 and nth-1;xpa-1. Our results also point to a two-tiered global response to combat the effects of decreased DNA repair capacity.
2010-04-12 | GSE16405 | GEO
Project description:Cockayne syndrome (CS) is a photosensitive, DNA repair disorder associated with progeria caused by a defect in the transcription-coupled repair (TCR) subpathway of nucleotide excision repair (NER). Here, complete inactivation of NER in Csbm/m/Xpa-/- mutants causes a phenotype that reliably mimics the human progeroid CS syndrome. Newborn Csbm/m/Xpa-/- mice display attenuated growth, progressive neurological dysfunction, retinal degeneration, cachexia, kyphosis and die before weaning. To investigate whether a disturbance in growth and metabolism could explain the pronounced accelerated organismal deterioration seen in Csbm/m/Xpa-/- mice, we evaluated the liver transcriptome of 15-day old wt, single and double mutant mice (n=4). At this age, the Csbm/m/Xpa-/- pups have not yet become cachectic. Mouse liver transcriptome analysis and several physiological endpoints revealed systemic suppression of the GH/IGF1 somatotroph axis and oxidative metabolism, increased antioxidant responses, hypoglycemia together with hepatic glycogen and fat accumulation. Broad genome-wide parallels between Csbm/m/Xpa-/- and naturally aged mouse liver transcriptomes suggested that these changes are intrinsic to natural aging and the DNA repair-deficient mice. Importantly, wild type (wt) mice exposed to a low dose of chronic genotoxic stress and adult Csbm/m mutant mice recapitulated this response, thereby pointing to a novel link between genome instability and the age-related decline of the somatotroph axis.
2007-01-01 | E-MEXP-835 | biostudies-arrayexpress
Project description:Purpose: Nucleotide excision repair (NER) in mammalian cells requires the xeroderma pigmentosum group A protein (XPA) as a core factor. Remarkably, XPA and other NER proteins have been detected by chromatin immunoprecipitation at some active promoters, and NER deficiency is reported to influence the activated transcription of selected genes. However, the global influence of XPA on transcription in human cells has not been determined. Methods: We analyzed the human transcriptome by RNA sequencing (RNA-Seq). Four genetically matched human cell line pairs deficient or proficient in XPA were analyzed Results: Of the ~14,000 genes transcribed in each cell line, 325 genes (2%) had a significant XPA-dependent directional change in gene expression that was common to all four pairs (with a false discovery rate of 0.05). These genes were enriched in pathways for the maintenance of mitochondria. Only 27 genes were different by more than 1.5-fold. The most significant hits were AKR1C1 and AKR1C2, involved in steroid hormone metabolism. AKR1C2 protein was lower in all of the immortalized XPA-deficient cells. Retinoic acid treatment led to modest XPA-dependent activation of some genes with transcription-related functions. Conclusions: We conclude that XPA status does not globally influence human gene transcription. However, XPA significantly influences expression of a small subset of genes important for mitochondrial functions and steroid hormone metabolism. The results may help explain defects in neurological function and sterility in individuals with xeroderma pigmentosum.
2017-07-07 | GSE100855 | GEO
Project description:Nucleotide excision repair (NER) is the major DNA repair pathway that removes UV-induced and bulky DNA lesions. There is currently no structure of NER intermediates, which form around the large multisubunit transcription factor IIH (TFIIH). Here we report the cryo-EM structure of an NER intermediate containing TFIIH and the NER factor XPA. Compared to its transcription conformation, the TFIIH structure is rearranged such that its ATPase subunits XPB and XPD bind double- and single-stranded DNA, consistent with their translocase and helicase activities, respectively. XPA releases the inhibitory kinase module of TFIIH, displaces a ‘plug’ element from the DNA-binding pore in XPD, and together with the NER factor XPG stimulates XPD activity. Our results explain how TFIIH is switched from a transcription to a repair factor, and provide the basis for a mechanistic analysis of the NER pathway.
2019-07-02 | PXD013947 | Pride