The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Danny Reinberg - One of the best experts on this subject based on the ideXlab platform.
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regulation of the histone h4 monomethylase pr set7 by crl4cdt2 mediated pcna dependent degradation during dna damage
Molecular Cell, 2010Co-Authors: Hisanobu Oda, Michael R Hubner, David B Beck, Michiel Vermeulen, Jerard Hurwitz, David L Spector, Danny ReinbergAbstract:Summary The histone methyltransferase PR-Set7/Set8 is the sole enzyme that catalyzes monomethylation of histone H4 at K20 (H4K20me1). Previous reports document disparate evidence regarding PR-Set7 expression during the cell cycle, the biological relevance of PR-Set7 interaction with PCNA, and its role in the cell. We find that PR-Set7 is indeed undetectable during S phase and instead is detected during late G2, mitosis, and early G1. PR-Set7 is transiently recruited to laser-induced DNA damage sites through its interaction with PCNA, after which 53BP1 is recruited dependent on PR-Set7 catalytic activity. During the DNA damage response, PR-Set7 interaction with PCNA through a specialized "PIP degron" domain targets it for PCNA-coupled CRL4 Cdt2 -dependent proteolysis. PR-Set7 mutant in its "PIP degron" is now detectable during S phase, during which the mutant protein accumulates. Outside the chromatin context, Skp2 promotes PR-Set7 degradation as well. These findings demonstrate a stringent spatiotemporal control of PR-Set7 that is essential for preserving the genomic integrity of mammalian cells.
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Monomethylation of histone H4-lysine 20 is involved in chromosome structure and stability and is essential for mouse development.
Molecular and Cellular Biology, 2009Co-Authors: Hisanobu Oda, Ikuhiro Okamoto, Niall Murphy, Jianhua Chu, Sandy Price, Michael Shen, Maria Elena Torres-padilla, Edith Heard, Danny ReinbergAbstract:PR-Set7/Set8/KMT5A is the sole enzyme known to catalyze monomethylation of histone H4 lysine 20 (H4K20) and is present only in multicellular organisms that compact a large fraction of their DNA. We found that mouse embryos that are homozygous null mutants for the gene PR-Set7 display early embryonic lethality prior to the eight-cell stage. Death was due to the absence of PR-Set7 catalytic activity, since microinjection of the wild type, but not a catalytically inactive version, into two-cell embryos rescued the phenotype. A lack of PR-Set7 activity resulted not only in depletion of H4K20me1 but also in reduced levels of the H4K20me2/3 marks catalyzed by the Suv4-20h1/h2 enzymes, implying that H4K20me1 may be essential for the function of these enzymes to ensure the dimethylated and trimethylated states. Embryonic stem cells that were inducibly deleted for PR-Set7 passed through an initial G(2)/M phase, but the progeny were defective at the subsequent S and G(2)/M phases, exhibiting a delay in their cell cycle, accumulation at G(2)/M, massive DNA damage, and improper mitotic chromosome condensation. Cell cycle analysis after synchronization indicated that the defects were a consequence of decreased H4K20me1 due to the absence of PR-Set7. Most importantly, the lack of H4K20me1 also resulted in defects in chromosome condensation in interphase nuclei. These results demonstrate the critical role of H4K20 monomethylation in mammals in a developmental context.
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tails of intrigue phosphorylation of rna polymerase ii mediates histone methylation
Cell, 2003Co-Authors: Michael Hampsey, Danny ReinbergAbstract:Histone lysine methylation plays a key role in the organization of chromatin structure and the regulation of gene expression. Recent studies demonstrated that the yeast Set1 and Set2 histone methyltransferases are recruited to mRNA coding regions by the PAF transcription elongation complex in a manner dependent upon the phosphorylation state of the carboxy-terminal domain of RNA polymerase II. These studies define an unexpected link between transcription elongation and histone methylation.
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set9 a novel histone h3 methyltransferase that facilitates transcription by precluding histone tail modifications required for heterochromatin formation
Genes & Development, 2002Co-Authors: Kenichi Nishioka, Sergei Chuikov, Kavitha Sarma, Hediye Erdjumentbromage, David C Allis, Paul Tempst, Danny ReinbergAbstract:A novel histone methyltransferase, termed Set9, was isolated from human cells. Set9 contains a SET domain, but lacks the pre- and post-SET domains. Set9 methylates specifically lysine 4 (K4) of histone H3 (H3-K4) and potentiates transcription activation. The histone H3 tail interacts specifically with the histone deacetylase NuRD complex. Methylation of histone H3-K4 by Set9 precludes the association of NuRD with the H3 tail. Moreover, methylation of H3-K4 impairs Suv39h1-mediated methylation at K9 of H3 (H3-K9). The interplay between the Set9 and Suv39h1 histone methyltransferases is specific, as the methylation of H3-K9 by the histone methyltransferase G9a was not affected by Set9 methylation of H3-K4. Our studies suggest that Set9-mediated methylation of H3-K4 functions in transcription activation by competing with histone deacetylases and by precluding H3-K9 methylation by Suv39h1. Our results suggest that the methylation of histone tails can have distinct effects on transcription, depending on its chromosomal location, the combination of posttranslational modifications, and the enzyme (or protein complex) involved in the particular modification.
Takao Masaki - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of the H3K4 methyltransferase SET7/9 ameliorates peritoneal fibrosis
PloS one, 2018Co-Authors: Ryo Tamura, Shigehiro Doi, Ayumu Nakashima, Kensuke Sasaki, Toshinori Ueno, Kazuya Maeda, Takao MasakiAbstract:Transforming growth factor-β1 (TGF-β1) is a major mediator of peritoneal fibrosis and reportedly affects expression of the H3K4 methyltransferase, SET7/9. SET7/9-induced H3K4 mono-methylation (H3K4me1) critically activates transcription of fibrosis-related genes. In this study, we examined the effect of SET7/9 inhibition on peritoneal fibrosis in mice and in human peritoneal mesothelial cells (HPMCs). We also examined SET7/9 expression in nonadherent cells isolated from the effluent of peritoneal dialysis (PD) patients. Murine peritoneal fibrosis was induced by intraperitoneal injection of methylglyoxal (MGO) into male C57/BL6 mice over 21 days. Sinefungin, a SET7/9 inhibitor, was administered subcutaneously just before MGO injection (10 mg/kg). SET7/9 expression was elevated in both MGO-injected mice and nonadherent cells isolated from the effluent of PD patients. SET7/9 expression was positively correlated with dialysate/plasma ratio of creatinine in PD patients. Sinefungin was shown immunohistochemically to suppress expression of mesenchymal cells and collagen deposition, accompanied by decreased H3K4me1 levels. Peritoneal equilibration tests showed that sinefungin attenuated the urea nitrogen transport rate from plasma and the glucose absorption rate from the dialysate. In vitro, sinefungin suppressed TGF-β1-induced expression of fibrotic markers and inhibited H3K4me1. These findings suggest that inhibiting the H3K4 methyltransferase SET7/9 ameliorates peritoneal fibrosis.
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inhibition of the h3k4 methyltransferase set7 9 ameliorates peritoneal fibrosis
PLOS ONE, 2018Co-Authors: Ryo Tamura, Shigehiro Doi, Ayumu Nakashima, Kensuke Sasaki, Toshinori Ueno, Kazuya Maeda, Takao MasakiAbstract:Transforming growth factor-β1 (TGF-β1) is a major mediator of peritoneal fibrosis and reportedly affects expression of the H3K4 methyltransferase, SET7/9. SET7/9-induced H3K4 mono-methylation (H3K4me1) critically activates transcription of fibrosis-related genes. In this study, we examined the effect of SET7/9 inhibition on peritoneal fibrosis in mice and in human peritoneal mesothelial cells (HPMCs). We also examined SET7/9 expression in nonadherent cells isolated from the effluent of peritoneal dialysis (PD) patients. Murine peritoneal fibrosis was induced by intraperitoneal injection of methylglyoxal (MGO) into male C57/BL6 mice over 21 days. Sinefungin, a SET7/9 inhibitor, was administered subcutaneously just before MGO injection (10 mg/kg). SET7/9 expression was elevated in both MGO-injected mice and nonadherent cells isolated from the effluent of PD patients. SET7/9 expression was positively correlated with dialysate/plasma ratio of creatinine in PD patients. Sinefungin was shown immunohistochemically to suppress expression of mesenchymal cells and collagen deposition, accompanied by decreased H3K4me1 levels. Peritoneal equilibration tests showed that sinefungin attenuated the urea nitrogen transport rate from plasma and the glucose absorption rate from the dialysate. In vitro, sinefungin suppressed TGF-β1-induced expression of fibrotic markers and inhibited H3K4me1. These findings suggest that inhibiting the H3K4 methyltransferase SET7/9 ameliorates peritoneal fibrosis.
Olivier J Becherel - One of the best experts on this subject based on the ideXlab platform.
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disruption of spermatogenesis and infertility in ataxia with oculomotor apraxia type 2 aoa2
The Cerebellum, 2019Co-Authors: Olivier J Becherel, Scott I Zeitlin, Hayden Homer, Brent L. Fogel, Hemamali Samaratunga, Jessica Greaney, Martin F. LavinAbstract:Ataxia with oculomotor apraxia type 2 (AOA2) is a rare autosomal recessive cerebellar ataxia characterized by onset between 10 and 20 years of age and a range of neurological features that include progressive cerebellar atrophy, axonal sensorimotor neuropathy, oculomotor apraxia in a majority of patients, and elevated serum alpha-fetoprotein (AFP). AOA2 is caused by mutation of the SETX gene which encodes senataxin, a DNA/RNA helicase involved in transcription regulation, RNA processing, and DNA maintenance. Disruption of senataxin in rodents led to defective spermatogenesis and sterility in males uncovering a key role for senataxin in male germ cell survival. Here, we report the first clinical and cellular evidence of impaired spermatogenesis in AOA2 patients. We assessed sperm production in three AOA2 patients and testicular pathology in one patient and compared the findings to those of SETX-knockout mice. Sperm production was impaired in all patients assessed (3/3, 100%). Analyses of testicular biopsies from an AOA2 patient recapitulate features of the histology seen in SETX-knockout mice, strongly suggesting an underlying mechanism centering on DNA-damage-mediated germ cell apoptosis. These findings support a role for senataxin in human reproductive function and highlight a novel clinical feature of AOA2 that extends the extra-neurological roles of senataxin. This raises an important reproductive counseling issue for clinicians, and fertility specialists should be aware of SETX mutations as a possible diagnosis in young male patients presenting with oligospermia or azoospermia since infertility may presage the later onset of neurological manifestations in some individuals.
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a new model to study neurodegeneration in ataxia oculomotor apraxia type 2
Human Molecular Genetics, 2015Co-Authors: Olivier J Becherel, Sam P Nayler, Brent L. Fogel, Ernst J Wolvetang, Chiara Criscuolo, Giuseppe Michele, Giovanni Coppola, Martin F. LavinAbstract:Ataxia oculomotor apraxia type 2 (AOA2) is a rare autosomal recessive cerebellar ataxia. Recent evidence suggests that the protein defective in this syndrome, senataxin (SETX), functions in RNA processing to protect the integrity of the genome. To date, only patient-derived lymphoblastoid cells, fibroblasts and SETX knockdown cells were available to investigate AOA2. Recent disruption of the SETX gene in mice did not lead to neurobehavioral defects or neurodegeneration, making it difficult to study the etiology of AOA2. To develop a more relevant neuronal model to study neurodegeneration in AOA2, we derived neural progenitors from a patient with AOA2 and a control by induced pluripotent stem cell (iPSC) reprogramming of fibroblasts. AOA2 iPSC and neural progenitors exhibit increased levels of oxidative damage, DNA double-strand breaks, increased DNA damage-induced cell death and R-loop accumulation. Genome-wide expression and weighted gene co-expression network analysis in these neural progenitors identified both previously reported and novel affected genes and cellular pathways associated with senataxin dysfunction and the pathophysiology of AOA2, providing further insight into the role of senataxin in regulating gene expression on a genome-wide scale. These data show that iPSCs can be generated from patients with the autosomal recessive ataxia, AOA2, differentiated into neurons, and that both cell types recapitulate the AOA2 cellular phenotype. This represents a novel and appropriate model system to investigate neurodegeneration in this syndrome.
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mutation of senataxin alters disease specific transcriptional networks in patients with ataxia with oculomotor apraxia type 2 p2 126
Neurology, 2015Co-Authors: Brent L. Fogel, Amanda Wahnich, Xizhe Wang, Francesca Fike, Leslie Chen, Olivier J Becherel, Chiara Criscuolo, Giuseppe Michele, Alessandro Filla, Abigail CollinsAbstract:Objective: To assess the functional role of senataxin in cerebellar and motor neuron disease pathogenesis through altered regulation of gene expression. Background: 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). Design/Methods: Genome-wide transcriptional microarray and RNA-sequencing was used to examine the effect of senataxin mutation on gene expression in cell lines and peripheral blood from AOA2 patients, transfected human cell lines, and SETX knockout mice. Results: 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. Conclusions: 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. Disclosure: Dr. Fogel has received personal compensation for activities with the American Physician Institute for Advanced Professional Studies. Dr. Fogel has received personal compensation in an editorial capacity for Neurologic Clinics. Dr. Cho has nothing to disclose. Dr. Wahnich has nothing to disclose. Dr. Gao has nothing to disclose. Dr. Becherel has nothing to disclose. Dr. Wang has nothing to disclose. Dr. Fike has nothing to disclose. Dr. Chen has nothing to disclose. Dr. Criscuolo has nothing to disclose. Dr. De Michele has nothing to disclose. Dr. Filla has nothing to disclose. Dr. Collins has nothing to disclose. Dr. Hahn has nothing to disclose. Dr. Gatti has nothing to disclose. Dr. Konopka has nothing to disclose. Dr. Perlman has received research support from Santhera Pharmaceuticals. Dr. Lavin has nothing to disclose. Dr. Geschwind has received personal compensation for activities with SynapDX, Allen Brain Institute, and Vanderbilt Kennedy Center. Dr. Coppola has nothing to disclose.
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mutation of senataxin alters disease specific transcriptional networks in patients with ataxia with oculomotor apraxia type 2
Human Molecular Genetics, 2014Co-Authors: Brent L. Fogel, Amanda Wahnich, Xizhe Wang, Francesca Fike, Leslie Chen, Olivier J Becherel, Chiara Criscuolo, Giuseppe Michele, Alessandro Filla, Abigail CollinsAbstract: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.
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senataxin defective in ataxia oculomotor apraxia type 2 is involved in the defense against oxidative dna damage
Journal of Cell Biology, 2007Co-Authors: Rick G Woods, Natalie Rundle, Magtouf Gatei, Olivier J Becherel, Amila Suraweera, Chiara Criscuolo, Jun Nakamura, Philip Chen, Alessandro FillaAbstract:Adefective response to DNA damage is observed in several human autosomal recessive ataxias with oculomotor apraxia, including ataxia-telangiectasia. We report that senataxin, defective in ataxia oculomotor apraxia (AOA) type 2, is a nuclear protein involved in the DNA damage response. AOA2 cells are sensitive to H2O2, camptothecin, and mitomycin C, but not to ionizing radiation, and sensitivity was rescued with full-length SETX cDNA. AOA2 cells exhibited constitutive oxidative DNA damage and enhanced chromosomal instability in response to H2O2. Rejoining of H2O2-induced DNA double-strand breaks (DSBs) was significantly reduced in AOA2 cells compared to controls, and there was no evidence for a defect in DNA single-strand break repair. This defect in DSB repair was corrected by full-length SETX cDNA. These results provide evidence that an additional member of the autosomal recessive AOA is also characterized by a defective response to DNA damage, which may contribute to the neurodegeneration seen in this syndrome.
Ryo Tamura - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of the H3K4 methyltransferase SET7/9 ameliorates peritoneal fibrosis
PloS one, 2018Co-Authors: Ryo Tamura, Shigehiro Doi, Ayumu Nakashima, Kensuke Sasaki, Toshinori Ueno, Kazuya Maeda, Takao MasakiAbstract:Transforming growth factor-β1 (TGF-β1) is a major mediator of peritoneal fibrosis and reportedly affects expression of the H3K4 methyltransferase, SET7/9. SET7/9-induced H3K4 mono-methylation (H3K4me1) critically activates transcription of fibrosis-related genes. In this study, we examined the effect of SET7/9 inhibition on peritoneal fibrosis in mice and in human peritoneal mesothelial cells (HPMCs). We also examined SET7/9 expression in nonadherent cells isolated from the effluent of peritoneal dialysis (PD) patients. Murine peritoneal fibrosis was induced by intraperitoneal injection of methylglyoxal (MGO) into male C57/BL6 mice over 21 days. Sinefungin, a SET7/9 inhibitor, was administered subcutaneously just before MGO injection (10 mg/kg). SET7/9 expression was elevated in both MGO-injected mice and nonadherent cells isolated from the effluent of PD patients. SET7/9 expression was positively correlated with dialysate/plasma ratio of creatinine in PD patients. Sinefungin was shown immunohistochemically to suppress expression of mesenchymal cells and collagen deposition, accompanied by decreased H3K4me1 levels. Peritoneal equilibration tests showed that sinefungin attenuated the urea nitrogen transport rate from plasma and the glucose absorption rate from the dialysate. In vitro, sinefungin suppressed TGF-β1-induced expression of fibrotic markers and inhibited H3K4me1. These findings suggest that inhibiting the H3K4 methyltransferase SET7/9 ameliorates peritoneal fibrosis.
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inhibition of the h3k4 methyltransferase set7 9 ameliorates peritoneal fibrosis
PLOS ONE, 2018Co-Authors: Ryo Tamura, Shigehiro Doi, Ayumu Nakashima, Kensuke Sasaki, Toshinori Ueno, Kazuya Maeda, Takao MasakiAbstract:Transforming growth factor-β1 (TGF-β1) is a major mediator of peritoneal fibrosis and reportedly affects expression of the H3K4 methyltransferase, SET7/9. SET7/9-induced H3K4 mono-methylation (H3K4me1) critically activates transcription of fibrosis-related genes. In this study, we examined the effect of SET7/9 inhibition on peritoneal fibrosis in mice and in human peritoneal mesothelial cells (HPMCs). We also examined SET7/9 expression in nonadherent cells isolated from the effluent of peritoneal dialysis (PD) patients. Murine peritoneal fibrosis was induced by intraperitoneal injection of methylglyoxal (MGO) into male C57/BL6 mice over 21 days. Sinefungin, a SET7/9 inhibitor, was administered subcutaneously just before MGO injection (10 mg/kg). SET7/9 expression was elevated in both MGO-injected mice and nonadherent cells isolated from the effluent of PD patients. SET7/9 expression was positively correlated with dialysate/plasma ratio of creatinine in PD patients. Sinefungin was shown immunohistochemically to suppress expression of mesenchymal cells and collagen deposition, accompanied by decreased H3K4me1 levels. Peritoneal equilibration tests showed that sinefungin attenuated the urea nitrogen transport rate from plasma and the glucose absorption rate from the dialysate. In vitro, sinefungin suppressed TGF-β1-induced expression of fibrotic markers and inhibited H3K4me1. These findings suggest that inhibiting the H3K4 methyltransferase SET7/9 ameliorates peritoneal fibrosis.
Chiara Criscuolo - One of the best experts on this subject based on the ideXlab platform.
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a new model to study neurodegeneration in ataxia oculomotor apraxia type 2
Human Molecular Genetics, 2015Co-Authors: Olivier J Becherel, Sam P Nayler, Brent L. Fogel, Ernst J Wolvetang, Chiara Criscuolo, Giuseppe Michele, Giovanni Coppola, Martin F. LavinAbstract:Ataxia oculomotor apraxia type 2 (AOA2) is a rare autosomal recessive cerebellar ataxia. Recent evidence suggests that the protein defective in this syndrome, senataxin (SETX), functions in RNA processing to protect the integrity of the genome. To date, only patient-derived lymphoblastoid cells, fibroblasts and SETX knockdown cells were available to investigate AOA2. Recent disruption of the SETX gene in mice did not lead to neurobehavioral defects or neurodegeneration, making it difficult to study the etiology of AOA2. To develop a more relevant neuronal model to study neurodegeneration in AOA2, we derived neural progenitors from a patient with AOA2 and a control by induced pluripotent stem cell (iPSC) reprogramming of fibroblasts. AOA2 iPSC and neural progenitors exhibit increased levels of oxidative damage, DNA double-strand breaks, increased DNA damage-induced cell death and R-loop accumulation. Genome-wide expression and weighted gene co-expression network analysis in these neural progenitors identified both previously reported and novel affected genes and cellular pathways associated with senataxin dysfunction and the pathophysiology of AOA2, providing further insight into the role of senataxin in regulating gene expression on a genome-wide scale. These data show that iPSCs can be generated from patients with the autosomal recessive ataxia, AOA2, differentiated into neurons, and that both cell types recapitulate the AOA2 cellular phenotype. This represents a novel and appropriate model system to investigate neurodegeneration in this syndrome.
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mutation of senataxin alters disease specific transcriptional networks in patients with ataxia with oculomotor apraxia type 2 p2 126
Neurology, 2015Co-Authors: Brent L. Fogel, Amanda Wahnich, Xizhe Wang, Francesca Fike, Leslie Chen, Olivier J Becherel, Chiara Criscuolo, Giuseppe Michele, Alessandro Filla, Abigail CollinsAbstract:Objective: To assess the functional role of senataxin in cerebellar and motor neuron disease pathogenesis through altered regulation of gene expression. Background: 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). Design/Methods: Genome-wide transcriptional microarray and RNA-sequencing was used to examine the effect of senataxin mutation on gene expression in cell lines and peripheral blood from AOA2 patients, transfected human cell lines, and SETX knockout mice. Results: 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. Conclusions: 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. Disclosure: Dr. Fogel has received personal compensation for activities with the American Physician Institute for Advanced Professional Studies. Dr. Fogel has received personal compensation in an editorial capacity for Neurologic Clinics. Dr. Cho has nothing to disclose. Dr. Wahnich has nothing to disclose. Dr. Gao has nothing to disclose. Dr. Becherel has nothing to disclose. Dr. Wang has nothing to disclose. Dr. Fike has nothing to disclose. Dr. Chen has nothing to disclose. Dr. Criscuolo has nothing to disclose. Dr. De Michele has nothing to disclose. Dr. Filla has nothing to disclose. Dr. Collins has nothing to disclose. Dr. Hahn has nothing to disclose. Dr. Gatti has nothing to disclose. Dr. Konopka has nothing to disclose. Dr. Perlman has received research support from Santhera Pharmaceuticals. Dr. Lavin has nothing to disclose. Dr. Geschwind has received personal compensation for activities with SynapDX, Allen Brain Institute, and Vanderbilt Kennedy Center. Dr. Coppola has nothing to disclose.
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mutation of senataxin alters disease specific transcriptional networks in patients with ataxia with oculomotor apraxia type 2
Human Molecular Genetics, 2014Co-Authors: Brent L. Fogel, Amanda Wahnich, Xizhe Wang, Francesca Fike, Leslie Chen, Olivier J Becherel, Chiara Criscuolo, Giuseppe Michele, Alessandro Filla, Abigail CollinsAbstract: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.
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senataxin defective in ataxia oculomotor apraxia type 2 is involved in the defense against oxidative dna damage
Journal of Cell Biology, 2007Co-Authors: Rick G Woods, Natalie Rundle, Magtouf Gatei, Olivier J Becherel, Amila Suraweera, Chiara Criscuolo, Jun Nakamura, Philip Chen, Alessandro FillaAbstract:Adefective response to DNA damage is observed in several human autosomal recessive ataxias with oculomotor apraxia, including ataxia-telangiectasia. We report that senataxin, defective in ataxia oculomotor apraxia (AOA) type 2, is a nuclear protein involved in the DNA damage response. AOA2 cells are sensitive to H2O2, camptothecin, and mitomycin C, but not to ionizing radiation, and sensitivity was rescued with full-length SETX cDNA. AOA2 cells exhibited constitutive oxidative DNA damage and enhanced chromosomal instability in response to H2O2. Rejoining of H2O2-induced DNA double-strand breaks (DSBs) was significantly reduced in AOA2 cells compared to controls, and there was no evidence for a defect in DNA single-strand break repair. This defect in DSB repair was corrected by full-length SETX cDNA. These results provide evidence that an additional member of the autosomal recessive AOA is also characterized by a defective response to DNA damage, which may contribute to the neurodegeneration seen in this syndrome.
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ataxia with oculomotor apraxia type 2 a clinical pathologic and genetic study
Neurology, 2006Co-Authors: Chiara Criscuolo, Luciana Chessa, Gaetano S Grieco, Francesco Sacca, S Giandomenico, M. Piane, F Barbieri, Pietro Mancini, Giuseppe Michele, Sandro BanfiAbstract:Background: Ataxia with oculomotor apraxia type 2 (AOA2) is characterized by onset between age 10 and 22 years, cerebellar atrophy, peripheral neuropathy, oculomotor apraxia (OMA), and elevated serum alpha-fetoprotein (AFP) levels. Recessive mutations in SETX have been described in AOA2 patients. Objective: To describe the clinical features of AOA2 and to identify the SETX mutations in 10 patients from four Italian families. Methods: The patients underwent clinical examination, routine laboratory tests, nerve conduction studies, sural nerve biopsy, and brain MRI. All were screened for SETX mutations. Results: All the patients had cerebellar features, including limb and truncal ataxia, and slurred speech. OMA was observed in two patients, extrapyramidal symptoms in two, and mental impairment in three. High serum AFP levels, motor and sensory axonal neuropathy, and marked cerebellar atrophy on MRI were detected in all the patients who underwent these examinations. Sural nerve biopsy revealed a severe depletion of large myelinated fibers in one patient, and both large and small myelinated fibers in another. Postmortem findings are also reported in one of the patients. Four different homozygous SETX mutations were found (a large-scale deletion, a missense change, a single-base deletion, and a splice-site mutation). Conclusions: The clinical phenotype of oculomotor apraxia type 2 is fairly homogeneous, showing only subtle intrafamilial variability. OMA is an inconstant finding. The identification of new mutations expands the array of SETX variants, and the finding of a missense change outside the helicase domain suggests the existence of at least one more functional region in the N-terminus of senataxin.
