scholarly journals Atrial fibrillation associated common risk variants in SYNE2 lead to lower expression of nesprin-2α1 and increased nuclear stiffness

2019 ◽  
Author(s):  
Nana Liu ◽  
Jeffrey Hsu ◽  
Gautam Mahajan ◽  
Han Sun ◽  
John Barnard ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Association Studies ◽  
Dominant Negative ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Gene Encoding ◽  
Enhancer Activity ◽  
Risk Alleles ◽  
Risk Variants ◽  
Lower Expression

ABSTRACTRationaleAtrial fibrillation (AF) genome-wide association studies (GWAS) identified significant associations for rs1152591 and linked variants in the SYNE2 gene encoding the nesprin-2 protein that connects the nuclear membrane with the cytoskeletonObjectiveDetermine the effects of the AF-associated rs1152591 and rs1152595, two linked intronic single nucleotide polymorphisms (SNPs), on SYNE2 expression and investigate the mechanisms for their association with AF.Methods and ResultsRNA sequencing of human left atrial appendage (LAA) tissues indicated that rs1152591 and rs1152595 were significantly associated with the expressions of SYNE2α1, a short mRNA isoform, without an effect on the expression of the full-length SYNE2 mRNA. SYNE2α1 mRNA uses an alternative transcription start site and encodes an N-terminal deleted 62 kDa nesprin-2α1 isoform, which can act as a dominant-negative on nuclear-cytoskeleton connectivity. Western blot and qPCR assays confirmed that AF risk alleles of both SNPs were associated with lower expression of nesprin-2α1 in human LAA tissues. Reporter gene transfections demonstrated that the risk vs. reference alleles of rs1152591 and rs1152595 had decreased enhancer activity. SYNE2 siRNA knockdown (KD) or nesprin-2α1 overexpression studies in human stem cell-derived induced cardiomyocytes (iCMs) resulted in ~12.5 % increases in the nuclear area compared to controls (p<0.001). Atomic force microscopy demonstrated that SYNE2 KD or nesprin-2α1 overexpression led to 57.5% or 33.2% decreases, respectively, in nuclear stiffness compared to controls (p< 0.0001).ConclusionsAF-associated SNPs rs1152591 and rs1152595 downregulate the expression of SYNE2α1, increasing nuclear-cytoskeletal connectivity and nuclear stiffness. The resulting increase in mechanical stress may play a role in the development of AF.

scholarly journals Host Genetic Variants Potentially Associated with SARS-Cov-2: A Multi-Population Analysis

2020 ◽  
Author(s):  
Maria K. Smatti ◽  
Yasser Al-Sarraj ◽  
Omar Albagha ◽  
Hadi M. Yassine
Keyword(s):  
Genetic Variants ◽  
Association Studies ◽  
Population Analysis ◽  
Fold Change ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Risk Alleles ◽  
Risk Variants ◽  
Genome Wide ◽  
Ifn Γ

Background: Clinical outcomes of Coronavirus Disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) showed enormous inter-individual and interpopulation differences, possibly due to host genetics differences. Earlier studies identified single nucleotide polymorphisms (SNPs) associated with SARS-CoV-1 in Eastern Asian (EAS) populations. In this report, we aimed at exploring the frequency of a set of genetic polymorphisms that could affect SARS-CoV-2 susceptibility or severity, including those that were previously associated with SARS-CoV-1. Methods: We extracted the list of SNPs that could potentially modulate SARS-CoV-2 from the genome wide association studies (GWAS) on SARS-CoV-1 and other viruses. We also collected the expression data of these SNPs from the expression quantitative trait loci (eQTLs) databases. Sequences from Qatar Genome Programme (QGP, n=6,054) and 1000Genome project were used to calculate and compare allelic frequencies (AF). Results: A total of 74 SNPs, located in 10 genes: ICAM3, IFN-γ, CCL2, CCL5, AHSG, MBL, Furin, TMPRSS2, IL4, and CD209 promoter, were identified. Analysis of Qatari genomes revealed significantly lower AF of risk variants linked to SARS-CoV-1 severity (CCL2, MBL, CCL5, AHSG, and IL4) compared to that of 1000Genome and/or the EAS population (up to 25-fold change). Conversely, SNPs in TMPRSS2, IFN-γ, ICAM3, and Furin were more common among Qataris (average 2-fold change). Inter-population analysis showed that the distribution of risk alleles among Europeans differs substantially from Africans and EASs. Remarkably, Africans seem to carry extremely lower frequencies of SARS-CoV-1 susceptibility alleles, reaching to 32-fold decrease compared to other populations. Conclusion: Multiple genetic variants, which could potentially modulate SARS-CoV-2 infection, are significantly variable between populations, with the lowest frequency observed among Africans. Our results highlight the importance of exploring population genetics to understand and predict COVID-19 outcomes. Indeed, further studies are needed to validate these findings as well as to identify new genetic determinants linked to SARS-CoV-2.

scholarly journals Upregulation of c-MYC in cis through a Large Chromatin Loop Linked to a Cancer Risk-Associated Single-Nucleotide Polymorphism in Colorectal Cancer Cells

2010 ◽  
Vol 30 (6) ◽  
pp. 1411-1420 ◽  
Author(s):  
Jason B. Wright ◽  
Seth J. Brown ◽  
Michael D. Cole
Keyword(s):  
Cancer Risk ◽  
Cancer Cells ◽  
Association Studies ◽  
Beta Catenin ◽  
Genome Wide Association Studies ◽  
Chromatin Loop ◽  
Nucleotide Polymorphisms ◽  
Distal Enhancer ◽  
Enhancer Activity ◽  
Single Nucleotide

ABSTRACT Genome-wide association studies have mapped many single-nucleotide polymorphisms (SNPs) that are linked to cancer risk, but the mechanism by which most SNPs promote cancer remains undefined. The rs6983267 SNP at 8q24 has been associated with many cancers, yet the SNP falls 335 kb from the nearest gene, c-MYC. We show that the beta-catenin-TCF4 transcription factor complex binds preferentially to the cancer risk-associated rs6983267(G) allele in colon cancer cells. We also show that the rs6983267 SNP has enhancer-related histone marks and can form a 335-kb chromatin loop to interact with the c-MYC promoter. Finally, we show that the SNP has no effect on the efficiency of chromatin looping to the c-MYC promoter but that the cancer risk-associated SNP enhances the expression of the linked c-MYC allele. Thus, cancer risk is a direct consequence of elevated c-MYC expression from increased distal enhancer activity and not from reorganization/creation of the large chromatin loop. The findings of these studies support a mechanism for intergenic SNPs that can promote cancer through the regulation of distal genes by utilizing preexisting large chromatin loops.

Abstract 18374: Targeted Sequencing and Massively Parallel Reporter Assay Identify the Functional Variation Underlying the 4q25 Locus for Atrial Fibrillation

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Nathan R Tucker ◽  
Jiangchuan Ye ◽  
Honghuang Lin ◽  
Michael A McLellan ◽  
Emelia J Benjamin ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Association Studies ◽  
Targeted Sequencing ◽  
Massively Parallel ◽  
Genome Wide Association Studies ◽  
Sequencing Analysis ◽  
Reporter Assay ◽  
Enhancer Activity ◽  
Functional Variants ◽  
Massively Parallel Reporter Assay

Introduction: Genome-wide association studies have identified 14 independent loci for atrial fibrillation (AF). The 4q25 locus upstream of the left-right asymmetry gene PITX2 is, by far, the strongest association signal for AF. However, as with most GWAS loci, the functional variants are noncoding, presumed to be regulatory, and remain unknown. We therefore sought to rapidly identify the functional variants at an AF locus by combining high throughput sequencing and massively parallel reporter assays. Methods and Results: We sequenced a ~750kb region encompassing the PITX2 locus in 462 individuals with early-onset AF from the MGH AF Study and 464 referents from the Framingham Heart Study. The SNP most significantly associated with AF in our sequenced sample was rs2129983, which is 140kb from PITX2 (OR=2.43, P =8.9X10 -16 ). rs2129983 is approximately 1.7kb from the most significantly associated SNP in a prior AF GWAS, rs6817105 (r 2 =0.52). From the targeted sequencing analysis, we identified 262 SNVs with a MAF >0.5% within a genomic region bounded by SNPs with an r2 greater than 0.4 with the top variant. To identify functional variants, we then utilized a massively parallel reporter assay (MPRA) in order to measure enhancer activity at each SNP across the entire AF locus. In both HL-1 and C2C12 myoblasts, MPRA identified many distinct SNP regions with differential enhancer activity. Using AF-association status as a standard, we were able to identify a series of variants that have both differential activity in either cell line tested and also a high level of association (rs17042076, rs4469143). Mechanistically, these functional SNPs are predicted to alter transcription factor binding. Conclusions: We have comprehensively identified the AF-associated variation at 4q25 and determined which of these variants are functional through differential enhancer activity. Here, in addition to identifying the causative variation for AF at 4q25, we provide a generalizable pathway for translating this work to other loci, a method that could expedite the identification of causative genetic variants at other disease loci.

scholarly journals Long-range Pitx2c enhancer–promoter interactions prevent predisposition to atrial fibrillation

2019 ◽  
Vol 116 (45) ◽  
pp. 22692-22698 ◽  
Author(s):  
Min Zhang ◽  
Matthew C. Hill ◽  
Zachary A. Kadow ◽  
Ji Ho Suh ◽  
Nathan R. Tucker ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Long Range ◽  
Association Studies ◽  
Ctcf Binding ◽  
Ctcf Binding Site ◽  
Genome Wide Association Studies ◽  
Range Interaction ◽  
Chromosome Conformation ◽  
Risk Variants ◽  
Increased Risk

Genome-wide association studies found that increased risk for atrial fibrillation (AF), the most common human heart arrhythmia, is associated with noncoding sequence variants located in proximity to PITX2. Cardiomyocyte-specific epigenomic and comparative genomics uncovered 2 AF-associated enhancers neighboring PITX2 with varying conservation in mice. Chromosome conformation capture experiments in mice revealed that the Pitx2c promoter directly contacted the AF-associated enhancer regions. CRISPR/Cas9-mediated deletion of a 20-kb topologically engaged enhancer led to reduced Pitx2c transcription and AF predisposition. Allele-specific chromatin immunoprecipitation sequencing on hybrid heterozygous enhancer knockout mice revealed that long-range interaction of an AF-associated region with the Pitx2c promoter was required for maintenance of the Pitx2c promoter chromatin state. Long-range looping was mediated by CCCTC-binding factor (CTCF), since genetic disruption of the intronic CTCF-binding site caused reduced Pitx2c expression, AF predisposition, and diminished active chromatin marks on Pitx2. AF risk variants located at 4q25 reside in genomic regions possessing long-range transcriptional regulatory functions directed at PITX2.

scholarly journals Integrative genomics analysis identifies five promising genes implicated in insomnia risk based on multiple omics datasets

2020 ◽  
Vol 40 (9) ◽  
Author(s):  
Haozhen Sun ◽  
Jianhua Zhang ◽  
Yunlong Ma ◽  
Jingjing Liu
Keyword(s):  
Brain Cortex ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Integrative Genomics ◽  
Bioinformatics Analyses ◽  
Risk Variants ◽  
Genome Wide ◽  
Brain Expression ◽  
Mice Brain ◽  
Lower Expression

Abstract In recent decades, many genome-wide association studies on insomnia have reported numerous genes harboring multiple risk variants. Nevertheless, the molecular functions of these risk variants conveying risk to insomnia are still ill-studied. In the present study, we integrated GWAS summary statistics (N=386,533) with two independent brain expression quantitative trait loci (eQTL) datasets (N=329) to determine whether expression-associated SNPs convey risk to insomnia. Furthermore, we applied numerous bioinformatics analyses to highlight promising genes associated with insomnia risk. By using Sherlock integrative analysis, we detected 449 significant insomnia-associated genes in the discovery stage. These identified genes were significantly overrepresented in six biological pathways including Huntington’s disease (P=5.58 × 10−5), Alzheimer’s disease (P=5.58 × 10−5), Parkinson’s disease (P=6.34 × 10−5), spliceosome (P=1.17 × 10−4), oxidative phosphorylation (P=1.09 × 10−4), and wnt signaling pathways (P=2.07 × 10−4). Further, five of these identified genes were replicated in an independent brain eQTL dataset. Through a PPI network analysis, we found that there existed highly functional interactions among these five identified genes. Three genes of LDHA (P=0.044), DALRD3 (P=5.0 × 10−5), and HEBP2 (P=0.032) showed significantly lower expression level in brain tissues of insomnic patients than that in controls. In addition, the expression levels of these five genes showed prominently dynamic changes across different time points between behavioral states of sleep and sleep deprivation in mice brain cortex. Together, the evidence of the present study strongly suggested that these five identified genes may represent candidate genes and contributed risk to the etiology of insomnia.

Abstract 4408: Using a Large Electronic Medical Record to Validate 4q25 Variants Conferring Risk for Atrial Fibrillation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Joshua C Denny ◽  
Marylyn D Ritchie ◽  
Dana C Crawford ◽  
Andrea Havens ◽  
Justin Weiner ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Language Processing ◽  
Association Studies ◽  
Genomic Research ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Heart Transplants ◽  
Text Documents ◽  
Research Populations ◽  
Processing Techniques

Background : Genome-wide association studies, largely in research populations, have identified susceptibility single-nucleotide polymorphisms (SNPs) for a broad range of human diseases, including variants at 4q25 associated with atrial fibrillation (AF). However, no studies have evaluated the applicability of these data to practice-based settings. Methods : This study was conducted in the Vanderbilt DNA Databank, a repository that accrues 500 –900 new samples/week from routine outpatient blood draws, and included 37,335 samples as of June 2, 2008. The Databank is linked to a de-identified derivative of the electronic medial record (EMR), which includes data for the last 15 years on 1.4 million subjects. We used natural language processing techniques and billing code queries to extract AF cases and controls without AF from the first 10,000 subjects entering the Databank. Cases had AF recorded in the cardiologist report of an electrocardiogram (ECG). Controls had at least one ECG and no AF, other abnormal atrial rhythms, or atrioventricular nodal ablation in any portion of the EMR, including text documents, billing codes, and ECGs. We excluded subjects with heart transplants and non-Caucasian ethnicity. Subjects were genotyped at rs2200733 and rs10033464, both located at 4q25, previously associated with AF with odds ratios (ORs) of 1.75 and 1.42, respectively. Results : We identified 168 cases with AF and 1695 controls. The electronic algorithms had an accuracy of 98% for identifying cases and 100% for controls over a random sample of 100 subjects each. The minor allele frequencies (MAF) for rs2200733 were 0.1419 for cases and 0.1032 for controls; the MAF for rs10033464 were 0.1019 for cases and 0.908 for controls. rs2200733 was significantly associated with AF (OR [95% confidence interval], 1.44 [1.01–2.03], p=0.04). The effect of rs10033464 on AF was not significant (OR, 1.14 [0.78 –1.67], p=0.52); however, power calculations indicate that 993 cases with AF were needed to replicate this effect. Conclusion : This practice-based study replicated an association identified in research datasets between a 4q25 SNP and AF. These findings support the utility of Electronic Medical Records coupled to DNA collections as resources for genomic research.

scholarly journals Silencing of CCR4-NOT complex subunits affects heart structure and function

2020 ◽  
Vol 13 (7) ◽  
pp. dmm044727 ◽  
Author(s):  
Lisa Elmén ◽  
Claudia B. Volpato ◽  
Anaïs Kervadec ◽  
Santiago Pineda ◽  
Sreehari Kalvakuri ◽  
...  
Keyword(s):  
Heart Development ◽  
Qt Interval ◽  
Association Studies ◽  
Induced Pluripotent Stem Cell ◽  
Interval Length ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Risk Alleles ◽  
And Function

ABSTRACTThe identification of genetic variants that predispose individuals to cardiovascular disease and a better understanding of their targets would be highly advantageous. Genome-wide association studies have identified variants that associate with QT-interval length (a measure of myocardial repolarization). Three of the strongest associating variants (single-nucleotide polymorphisms) are located in the putative promotor region of CNOT1, a gene encoding the central CNOT1 subunit of CCR4-NOT: a multifunctional, conserved complex regulating gene expression and mRNA stability and turnover. We isolated the minimum fragment of the CNOT1 promoter containing all three variants from individuals homozygous for the QT risk alleles and demonstrated that the haplotype associating with longer QT interval caused reduced reporter expression in a cardiac cell line, suggesting that reduced CNOT1 expression might contribute to abnormal QT intervals. Systematic siRNA-mediated knockdown of CCR4-NOT components in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) revealed that silencing CNOT1 and other CCR4-NOT genes reduced their proliferative capacity. Silencing CNOT7 also shortened action potential duration. Furthermore, the cardiac-specific knockdown of Drosophila orthologs of CCR4-NOT genes in vivo (CNOT1/Not1 and CNOT7/8/Pop2) was either lethal or resulted in dilated cardiomyopathy, reduced contractility or a propensity for arrhythmia. Silencing CNOT2/Not2, CNOT4/Not4 and CNOT6/6L/twin also affected cardiac chamber size and contractility. Developmental studies suggested that CNOT1/Not1 and CNOT7/8/Pop2 are required during cardiac remodeling from larval to adult stages. To summarize, we have demonstrated how disease-associated genes identified by GWAS can be investigated by combining human cardiomyocyte cell-based and whole-organism in vivo heart models. Our results also suggest a potential link of CNOT1 and CNOT7/8 to QT alterations and further establish a crucial role of the CCR4-NOT complex in heart development and function.This article has an associated First Person interview with the first author of the paper.

Abstract 18865: Identification of a Functional SNP Regulating PRRX1 at the 1q24 Locus for Atrial Fibrillation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Elena Dolmatova ◽  
Nathan R Tucker ◽  
Honghuang Lin ◽  
Rebecca R Cooper ◽  
Jiangchuan Ye ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Action Potential ◽  
Action Potential Duration ◽  
Association Studies ◽  
Physical Interaction ◽  
Eqtl Analysis ◽  
Genome Wide Association Studies ◽  
Enhancer Activity ◽  
Atrial Tissue ◽  
Functional Snp

Introduction: Genome-wide association studies have identified 9 genomic loci associated with atrial fibrillation (AF). Hypothesis: We sought to identify the functional variant at the 1q24 locus for AF, located upstream of the paired related homeobox 1 gene ( PRRX1 ). Methods: We used morpholino-mediated knockdown in zebrafish to assess the role of PRRX1 in cardiac function and development. To identify potential enhancers at the PRRX1 locus we analyzed DNase hypersensitivity, histone methylation, and mammalian conservation data from ENCODE. Tissue-specific enhancer activity was evaluated by microinjection of eGFP reporter constructs for each putative enhancer into zebrafish and luciferase assays in a mouse atrial myocyte (HL-1) cell line. To determine physical interaction between the AF-associated enhancer and PRRX1 promoter we analyzed available Hi-C data and performed chromatin conformation capture (3C). The functional SNP was localized using luciferase assays in HL-1 cells. The effect of the functional SNP on gene expression in human left atrial tissue was measured by qPCR. Results: Knockdown of the PRRX1 ortholog in zebrafish resulted in atrial dilation and shortening of atrial action potential duration (APD 80 : 114.8±2.2ms vs 126±1.5ms in controls, p=0.0004). Of the 4 regions tested at the 1q24 locus, 2 adjacent regions exhibited enhancer activity in the zebrafish myocardium. 3C demonstrated an increased interaction frequency between the enhancer and PRRX1 promoter regions in cells of cardiac lineage when compared to controls (103±57%, p=0.038). Screening for functional SNPs within these regions revealed that the AF risk allele (C) at SNP rs577676 associated with ~4 fold increased enhancer activity as compared to the non-risk (T) allele in HL-1 cells. Finally, regional eQTL analysis of human atrial tissue showed that rs577676 correlated with PRRX1 expression. Conclusions: We have implicated PRRX1 in cardiac electrophysiology by demonstrating that knockdown of the gene results in atrial dilation and shortening of atrial action potential duration. Further, we have found that SNP rs577676 modifies an enhancer regulating PRRX1 expression.

scholarly journals The Role of 39 Psoriasis Risk Variants on Age of Psoriasis Onset

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Yingchang Lu ◽  
Sinae Kane ◽  
Haoyan Chen ◽  
Argentina Leon ◽  
Ethan Levin ◽  
...  
Keyword(s):  
Age Of Onset ◽  
Association Studies ◽  
Meta Analysis ◽  
Genome Wide Association Studies ◽  
Risk Alleles ◽  
False Discovery ◽  
Risk Variants ◽  
Genome Wide ◽  
Independent Cohort

Recent genome-wide association studies (GWAS) have identified multiple genetic risk factors for psoriasis, but data on their association with age of onset have been marginally explored. The goal of this study was to evaluate known risk alleles of psoriasis for association with age of psoriasis onset in three well-defined case-only cohorts totaling 1,498 psoriasis patients. We selected 39 genetic variants from psoriasis GWAS and tested these variants for association with age of psoriasis onset in a meta-analysis. We found that rs10484554 and rs12191877 near HLA-C and rs17716942 near IFIH1 were associated with age of psoriasis onset with false discovery rate < 0.05. The association between rs17716942 and age of onset was not replicated in a fourth independent cohort of 489 patients (). The imputed HLA-C*06:02 allele demonstrated a much stronger association with age of psoriasis onset than rs10484554 and rs12191877. We conclude that despite the discovery of numerous psoriasis risk alleles, HLA-C*06:02 still plays the most important role in determining the age of onset of psoriasis. Larger studies are needed to evaluate the contribution of other risk alleles, including IFIH1, to age of psoriasis onset.

scholarly journals Genetic Predisposition to the Mortality in Septic Shock Patients: From GWAS to the Identification of a Regulatory Variant Modulating the Activity of a CISH Enhancer

2021 ◽  
Vol 22 (11) ◽  
pp. 5852
Author(s):  
Florian Rosier ◽  
Audrey Brisebarre ◽  
Claire Dupuis ◽  
Sabrina Baaklini ◽  
Denis Puthier ◽  
...  
Keyword(s):  
Septic Shock ◽  
Association Studies ◽  
Significant Snps ◽  
K562 Cells ◽  
Strong Linkage Disequilibrium ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphisms ◽  
Coding Region ◽  
Enhancer Activity ◽  
Risk Of Death

The high mortality rate in septic shock patients is likely due to environmental and genetic factors, which influence the host response to infection. Two genome-wide association studies (GWAS) on 832 septic shock patients were performed. We used integrative bioinformatic approaches to annotate and prioritize the sepsis-associated single nucleotide polymorphisms (SNPs). An association of 139 SNPs with death based on a false discovery rate of 5% was detected. The most significant SNPs were within the CISH gene involved in cytokine regulation. Among the 139 SNPs associated with death and the 1311 SNPs in strong linkage disequilibrium with them, we investigated 1439 SNPs within non-coding regions to identify regulatory variants. The highest integrative weighted score (IW-score) was obtained for rs143356980, indicating that this SNP is a robust regulatory candidate. The rs143356980 region is located in a non-coding region close to the CISH gene. A CRISPR-Cas9-mediated deletion of this region and specific luciferase assays in K562 cells showed that rs143356980 modulates the enhancer activity in K562 cells. These analyses allowed us to identify several genes associated with death in patients with septic shock. They suggest that genetic variations in key genes, such as CISH, perturb relevant pathways, increasing the risk of death in sepsis patients.

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