ABSTRACT: Here we investigated the RNA helicase Senataxin (SETX), an enzyme that resolve RNA-DNA hybrids and R-loops, to address its role in preventing replicative stress by oncogenic Myc. Silencing of SETX led to selective engagement of the DNA damage response (DDR) upon Myc activation, leading to a robust cytotoxicity. Pharmacological dissection of the upstream kinases regulating the DDR revealed a protective role of the ATR pathway, that once inactivated, boosted SETX driven-DDR. While loss of SETX did not lead to a genome-wide increase of R-loops, mechanistic analyses revealed enhanced R-loops localized at DDR-foci and newly replicated genomic loci, compatible with a selective role of SETX in resolving RNA-DNA hybrids to alleviate Myc-induced RS.
Project description:Here we investigated the RNA helicase Senataxin (SETX), an enzyme that resolve RNA-DNA hybrids and R-loops, to address its role in preventing replicative stress by oncogenic Myc. Silencing of SETX led to selective engagement of the DNA damage response (DDR) upon Myc activation, leading to a robust cytotoxicity. Pharmacological dissection of the upstream kinases regulating the DDR revealed a protective role of the ATR pathway, that once inactivated, boosted SETX driven-DDR. While loss of SETX did not lead to a genome-wide increase of R-loops, mechanistic analyses revealed enhanced R-loops localized at DDR-foci and newly replicated genomic loci, compatible with a selective role of SETX in resolving RNA-DNA hybrids to alleviate Myc-induced RS.
Project description:Here we investigated the RNA helicase Senataxin (SETX), an enzyme that resolve RNA-DNA hybrids and R-loops, to address its role in preventing replicative stress by oncogenic Myc. Silencing of SETX led to selective engagement of the DNA damage response (DDR) upon Myc activation, leading to a robust cytotoxicity. Pharmacological dissection of the upstream kinases regulating the DDR revealed a protective role of the ATR pathway, that once inactivated, boosted SETX driven-DDR. While loss of SETX did not lead to a genome-wide increase of R-loops, mechanistic analyses revealed enhanced R-loops localized at DDR-foci and newly replicated genomic loci, compatible with a selective role of SETX in resolving RNA-DNA hybrids to alleviate Myc-induced RS.
Project description:Analysis of senataxin effect on neuronal differentiation and neurite growth in RA-treated P19 cells by modulating senataxin expression levels. Senataxin silencing does not grossly affect the gene expression profiles of P19 cells At day one total RNA from Setx shRNA P19 cells, wild type human Setx P19 transfected cells with and without retionoic acid were used to compare gene expression profiling versus P19 control cells
Project description:Senataxin, encoded by the SETX gene, contributes to multiple aspects of gene expression, including transcription and RNA processing. Mutations in SETX cause the recessive disorder ataxia with oculomotor apraxia type 2 (AOA2) and a dominant juvenile form of amyotrophic lateral sclerosis (ALS4). To assess the functional role of senataxin in disease, we examined differential gene expression in AOA2 patient fibroblasts, identifying a core set of genes showing altered expression by microarray and RNA-sequencing. To determine whether AOA2 and ALS4 mutations differentially affect gene expression, we overexpressed disease-specific SETX mutations in senataxin-haploinsufficient fibroblasts and observed changes in distinct sets of genes. This implicates mutation-specific alterations of senataxin function in disease pathogenesis and provides a novel example of allelic neurogenetic disorders with differing gene expression profiles. Weighted gene co-expression network analysis (WGCNA) demonstrated these senataxin-associated genes to be involved in both mutation-specific and shared functional gene networks. To assess this in vivo, we performed gene expression analysis on peripheral blood from members of 12 different AOA2 families and identified an AOA2-specific transcriptional signature. WGCNA identified two gene modules highly enriched for this transcriptional signature in the peripheral blood of all AOA2 patients studied. These modules were disease-specific and preserved in patient fibroblasts and in the cerebellum of Setx knockout mice demonstrating conservation across species and cell types, including neurons. These results identify novel genes and cellular pathways related to senataxin function in normal and disease states, and implicate alterations in gene expression as underlying the phenotypic differences between AOA2 and ALS4. Total RNA samples obtained from 1) an AOA2 patient and carrier fibroblast cell lines, 2) 2 biological replicates of haploinsufficient SETX fibroblast cell lines transfected with one of 4 different wild-type and mutant SETX constructs, 3) peripheral blood from 33 patients and carriers across 12 families, and 4) 2 tissues from 2 Setx knockout and 2 control mice were analyzed using expression microarray. This submission represents the microarray component of study.
Project description:Senataxin, encoded by the SETX gene, contributes to multiple aspects of gene expression, including transcription and RNA processing. Mutations in SETX cause the recessive disorder ataxia with oculomotor apraxia type 2 (AOA2) and a dominant juvenile form of amyotrophic lateral sclerosis (ALS4). To assess the functional role of senataxin in disease, we examined differential gene expression in AOA2 patient fibroblasts, identifying a core set of genes showing altered expression by microarray and RNA-sequencing. To determine whether AOA2 and ALS4 mutations differentially affect gene expression, we overexpressed disease-specific SETX mutations in senataxin-haploinsufficient fibroblasts and observed changes in distinct sets of genes. This implicates mutation-specific alterations of senataxin function in disease pathogenesis and provides a novel example of allelic neurogenetic disorders with differing gene expression profiles. Weighted gene co-expression network analysis (WGCNA) demonstrated these senataxin-associated genes to be involved in both mutation-specific and shared functional gene networks. To assess this in vivo, we performed gene expression analysis on peripheral blood from members of 12 different AOA2 families and identified an AOA2-specific transcriptional signature. WGCNA identified two gene modules highly enriched for this transcriptional signature in the peripheral blood of all AOA2 patients studied. These modules were disease-specific and preserved in patient fibroblasts and in the cerebellum of Setx knockout mice demonstrating conservation across species and cell types, including neurons. These results identify novel genes and cellular pathways related to senataxin function in normal and disease states, and implicate alterations in gene expression as underlying the phenotypic differences between AOA2 and ALS4. Total RNA samples obtained from 1) an AOA2 patient and carrier fibroblast cell lines, 2) 2 biological replicates of haploinsufficient SETX fibroblast cell lines transfected with one of 4 different wild-type and mutant SETX constructs, 3) peripheral blood from 33 patients and carriers across 12 families, and 4) 2 tissues from 2 Setx knockout and 2 control mice were analyzed using expression microarray. This submission represents the microarray component of study.
Project description:Senataxin, encoded by the SETX gene, contributes to multiple aspects of gene expression, including transcription and RNA processing. Mutations in SETX cause the recessive disorder ataxia with oculomotor apraxia type 2 (AOA2) and a dominant juvenile form of amyotrophic lateral sclerosis (ALS4). To assess the functional role of senataxin in disease, we examined differential gene expression in AOA2 patient fibroblasts, identifying a core set of genes showing altered expression by microarray and RNA-sequencing. To determine whether AOA2 and ALS4 mutations differentially affect gene expression, we overexpressed disease-specific SETX mutations in senataxin-haploinsufficient fibroblasts and observed changes in distinct sets of genes. This implicates mutation-specific alterations of senataxin function in disease pathogenesis and provides a novel example of allelic neurogenetic disorders with differing gene expression profiles. Weighted gene co-expression network analysis (WGCNA) demonstrated these senataxin-associated genes to be involved in both mutation-specific and shared functional gene networks. To assess this in vivo, we performed gene expression analysis on peripheral blood from members of 12 different AOA2 families and identified an AOA2-specific transcriptional signature. WGCNA identified two gene modules highly enriched for this transcriptional signature in the peripheral blood of all AOA2 patients studied. These modules were disease-specific and preserved in patient fibroblasts and in the cerebellum of Setx knockout mice demonstrating conservation across species and cell types, including neurons. These results identify novel genes and cellular pathways related to senataxin function in normal and disease states, and implicate alterations in gene expression as underlying the phenotypic differences between AOA2 and ALS4. Total RNA samples obtained from 1) an AOA2 patient and carrier fibroblast cell lines, 2) 2 biological replicates of haploinsufficient SETX fibroblast cell lines transfected with one of 4 different wild-type and mutant SETX constructs, 3) peripheral blood from 33 patients and carriers across 12 families, and 4) 2 tissues from 2 Setx knockout and 2 control mice were analyzed using expression microarray. This submission represents the microarray component of study.
Project description:Senataxin, encoded by the SETX gene, contributes to multiple aspects of gene expression, including transcription and RNA processing. Mutations in SETX cause the recessive disorder ataxia with oculomotor apraxia type 2 (AOA2) and a dominant juvenile form of amyotrophic lateral sclerosis (ALS4). To assess the functional role of senataxin in disease, we examined differential gene expression in AOA2 patient fibroblasts, identifying a core set of genes showing altered expression by microarray and RNA-sequencing. To determine whether AOA2 and ALS4 mutations differentially affect gene expression, we overexpressed disease-specific SETX mutations in senataxin-haploinsufficient fibroblasts and observed changes in distinct sets of genes. This implicates mutation-specific alterations of senataxin function in disease pathogenesis and provides a novel example of allelic neurogenetic disorders with differing gene expression profiles. Weighted gene co-expression network analysis (WGCNA) demonstrated these senataxin-associated genes to be involved in both mutation-specific and shared functional gene networks. To assess this in vivo, we performed gene expression analysis on peripheral blood from members of 12 different AOA2 families and identified an AOA2-specific transcriptional signature. WGCNA identified two gene modules highly enriched for this transcriptional signature in the peripheral blood of all AOA2 patients studied. These modules were disease-specific and preserved in patient fibroblasts and in the cerebellum of Setx knockout mice demonstrating conservation across species and cell types, including neurons. These results identify novel genes and cellular pathways related to senataxin function in normal and disease states, and implicate alterations in gene expression as underlying the phenotypic differences between AOA2 and ALS4. Total RNA samples obtained from 1) an AOA2 patient and carrier fibroblast cell lines, 2) 2 biological replicates of haploinsufficient SETX fibroblast cell lines transfected with one of 4 different wild-type and mutant SETX constructs, 3) peripheral blood from 33 patients and carriers across 12 families, and 4) 2 tissues from 2 Setx knockout and 2 control mice were analyzed using expression microarray. This submission represents the microarray component of study.