Transcriptional Consequences of XPA Disruption in Human Cell Lines
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE100855 | GEO | 2017/07/07
SECONDARY ACCESSION(S): PRJNA393295
REPOSITORIES: GEO
Similar Datasets
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: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:Xeroderma pigmentosum type A (XP-A) is a hereditary disease characterized by early onset of skin cancers development by ultraviolet (UV) exposure. Although etiology of susceptible to skin tumor of XP-A is well investigated as a repair deficiency by UV-induced DNA damage, the mechanism of unusual strong and prolonged skin inflammation caused by UV in XP-A and whether UV-induced inflammatory response relates to skin tumor-prone phenotype remains to be elucidated. Among up-regulated inflammatory response related genes in Xpa mice compared with wild-type by gene profiling study, Cxcl1 in Xpa mice was significantly different from wild-type and blood level of Cxcl1 was increased with UVB exposed on even small area of skin in Xpa mice. We administered Cxcl1 neutralizing antibody or antioxidant agent n-acetylcysteine for Xpa mice after UVB irradiation, showing that blood levels of Cxcl1, ear swelling and skin redness as an inflammatory response were significantly suppressed. Xpa mice with chronic UVB exposure and Cxcl1 neutralizing antibody or n-acetylcysteine administered Xpa mice yields much less skin tumors compared with control group. Those results indicate that highly inflammatory response of Xpa mice by UVB plays a role of skin tumor development that could be suppressed by chemokine as Cxcl1 through antioxidant mechanism.
2017-06-01 | GSE86093 | GEO
Project description:Mitochondrial dysfunction is a common feature in neurodegeneration and aging. We identify mitochondrial dysfunction in xeroderma pigmentosum group A (XPA), a nucleotide excision DNA repair disorder with severe neurodegeneration, in silico and in vivo. XPA deficient cells show defective mitophagy with excessive cleavage of PINK1 and increased mitochondrial membrane potential. The mitochondrial abnormalities appear to be caused by decreased activation of the NAD+-SIRT1-PGC-1α axis triggered by hyperactivation of the DNA damage sensor PARP1. This phenotype is rescued by PARP1 inhibition or by supplementation with NAD+ precursors that also rescue the lifespan defect in xpa-1 nematodes. Importantly, this pathogenesis appears common to ataxia-telangiectasia and Cockayne syndrome, two other DNA repair disorders with neurodegeneration, but absent in XPC, a DNA repair disorder without neurodegeneration. Our findings reveal a novel nuclear-mitochondrial cross-talk that is critical for the maintenance of mitochondrial health.
2015-06-04 | GSE55485 | GEO
Project description:Mitochondrial dysfunction is a common feature in neurodegeneration and aging. We identify mitochondrial dysfunction in xeroderma pigmentosum group A (XPA), a nucleotide excision DNA repair disorder with severe neurodegeneration, in silico and in vivo. XPA deficient cells show defective mitophagy with excessive cleavage of PINK1 and increased mitochondrial membrane potential. The mitochondrial abnormalities appear to be caused by decreased activation of the NAD+-SIRT1-PGC-1α axis triggered by hyperactivation of the DNA damage sensor PARP1. This phenotype is rescued by PARP1 inhibition or by supplementation with NAD+ precursors that also rescue the lifespan defect in xpa-1 nematodes. Importantly, this pathogenesis appears common to ataxia-telangiectasia and Cockayne syndrome, two other DNA repair disorders with neurodegeneration, but absent in XPC, a DNA repair disorder without neurodegeneration. Our findings reveal a novel nuclear-mitochondrial cross-talk that is critical for the maintenance of mitochondrial health.
2015-06-04 | GSE55484 | 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
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>
| phs001867 | dbGaP
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:DNA-protein crosslinks (DPCs), arise from enzymatic intermediates, endogenous metabolism or exogenous chemicals like chemotherapeutics. DPCs are highly cytotoxic as they will impede DNA transacting processes such as replication, which is counteracted by proteolysis-mediated DPC removal by the protease SPRTN or the proteasome. However, how DPCs affect transcription and how transcription-blocking DPCs are repaired remains largely unknown. Here, we show that DPCs severely inhibit RNA polymerase II (Pol II)-mediated transcription, resulting in the recruitment of the transcription-coupled nucleotide excision repair (TC-NER) factors CSA and CSB. Interestingly, CSA and CSB are indispensable for transcription-coupled DPC (TC-DPC) repair, while the downstream TC-NER factors UVSSA and XPA are not, indicative of a non-canonical TC-NER mechanism. TC-DPC repair functions independent of SPRTN, but is mediated by the activities of the ubiquitin ligase CRL4CSA and the proteasome. Thus, DPCs are preferentially repaired in genes by a dedicated transcription-coupled repair mechanism, which is crucial to warrant correct transcription.
2024-02-09 | PXD041679 | Pride