The Experts below are selected from a list of 27768 Experts worldwide ranked by ideXlab platform
Lorella M T Canzoniero - One of the best experts on this subject based on the ideXlab platform.
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the neurotoxicant pcb 95 by increasing the neuronal Transcriptional repressor rest down regulates caspase 8 and increases ripk1 ripk3 and mlkl expression determining necroptotic neuronal death
Biochemical Pharmacology, 2017Co-Authors: Natascia Guida, Giusy Laudati, Angelo Serani, Paolo Montuori, Luigi Mascolo, Lorella M T Canzoniero, Gianfranco Di Renzo, Pasquale MolinaroAbstract:Abstract Our previous study showed that the environmental neurotoxicant non-dioxin-like polychlorinated biphenyl (PCB)-95 increases RE1-silencing Transcription Factor (REST) expression, which is related to necrosis, but not apoptosis, of neurons. Meanwhile, necroptosis is a type of a programmed necrosis that is positively regulated by receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like (MLKL) and negatively regulated by caspase-8. Here we evaluated whether necroptosis contributes to PCB-95-induced neuronal death through REST up-regulation. Our results demonstrated that in cortical neurons PCB-95 increased RIPK1, RIPK3, and MLKL expression and decreased caspase-8 at the gene and protein level. Furthermore, the RIPK1 inhibitor necrostatin-1 or siRNA-mediated RIPK1, RIPK3 and MLKL expression knockdown significantly reduced PCB-95-induced neuronal death. Intriguingly, PCB-95-induced increases in RIPK1, RIPK3, MLKL expression and decreases in caspase-8 expression were reversed by knockdown of REST expression with a REST-specific siRNA (siREST). Notably, in silico analysis of the rat genome identified a REST consensus sequence in the caspase-8 gene promoter (Casp8-RE1), but not the RIPK1, RIPK3 and MLKL promoters. Interestingly, in PCB-95-treated neurons, REST binding to the Casp8-RE1 sequence increased in parallel with a reduction in its promoter activity, whereas under the same experimental conditions, transfection of siREST or mutation of the Casp8-RE1 sequence blocked PCB-95-induced caspase-8 reduction. Since RIPK1, RIPK3 and MLKL rat genes showed no putative REST binding site, we assessed whether the Transcription Factor cAMP Responsive Element Binding Protein (CREB), which has a consensus sequence in all three genes, affected neuronal death. In neurons treated with PCB-95, CREB protein expression decreased in parallel with a reduction in binding to the RIPK1, RIPK3 and MLKL gene promoter sequence. Furthermore, CREB overexpression was associated with reduced promoter activity of the RIPK1, RIPK3 and MLKL genes. Collectively, these results indicate that PCB-95 was associated with REST-induced necroptotic cell death by increasing RIPK1, RIPK3 and MLKL expression and reducing caspase-8 levels. In addition, since REST is involved in several neurological disorders, therapies that block REST-induced necroptosis could be a new strategy to revert the neurodetrimental effects associated to its overexpression.
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the neurotoxicant pcb 95 by increasing the neuronal Transcriptional repressor rest down regulates caspase 8 and increases ripk1 ripk3 and mlkl expression determining necroptotic neuronal death
Biochemical Pharmacology, 2017Co-Authors: Natascia Guida, Giusy Laudati, Angelo Serani, Paolo Montuori, Luigi Mascolo, Lorella M T Canzoniero, Gianfranco Di Renzo, Pasquale MolinaroAbstract:Abstract Our previous study showed that the environmental neurotoxicant non-dioxin-like polychlorinated biphenyl (PCB)-95 increases RE1-silencing Transcription Factor (REST) expression, which is related to necrosis, but not apoptosis, of neurons. Meanwhile, necroptosis is a type of a programmed necrosis that is positively regulated by receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like (MLKL) and negatively regulated by caspase-8. Here we evaluated whether necroptosis contributes to PCB-95-induced neuronal death through REST up-regulation. Our results demonstrated that in cortical neurons PCB-95 increased RIPK1, RIPK3, and MLKL expression and decreased caspase-8 at the gene and protein level. Furthermore, the RIPK1 inhibitor necrostatin-1 or siRNA-mediated RIPK1, RIPK3 and MLKL expression knockdown significantly reduced PCB-95-induced neuronal death. Intriguingly, PCB-95-induced increases in RIPK1, RIPK3, MLKL expression and decreases in caspase-8 expression were reversed by knockdown of REST expression with a REST-specific siRNA (siREST). Notably, in silico analysis of the rat genome identified a REST consensus sequence in the caspase-8 gene promoter (Casp8-RE1), but not the RIPK1, RIPK3 and MLKL promoters. Interestingly, in PCB-95-treated neurons, REST binding to the Casp8-RE1 sequence increased in parallel with a reduction in its promoter activity, whereas under the same experimental conditions, transfection of siREST or mutation of the Casp8-RE1 sequence blocked PCB-95-induced caspase-8 reduction. Since RIPK1, RIPK3 and MLKL rat genes showed no putative REST binding site, we assessed whether the Transcription Factor cAMP Responsive Element Binding Protein (CREB), which has a consensus sequence in all three genes, affected neuronal death. In neurons treated with PCB-95, CREB protein expression decreased in parallel with a reduction in binding to the RIPK1, RIPK3 and MLKL gene promoter sequence. Furthermore, CREB overexpression was associated with reduced promoter activity of the RIPK1, RIPK3 and MLKL genes. Collectively, these results indicate that PCB-95 was associated with REST-induced necroptotic cell death by increasing RIPK1, RIPK3 and MLKL expression and reducing caspase-8 levels. In addition, since REST is involved in several neurological disorders, therapies that block REST-induced necroptosis could be a new strategy to revert the neurodetrimental effects associated to its overexpression.
Giusy Laudati - One of the best experts on this subject based on the ideXlab platform.
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the neurotoxicant pcb 95 by increasing the neuronal Transcriptional repressor rest down regulates caspase 8 and increases ripk1 ripk3 and mlkl expression determining necroptotic neuronal death
Biochemical Pharmacology, 2017Co-Authors: Natascia Guida, Giusy Laudati, Angelo Serani, Paolo Montuori, Luigi Mascolo, Lorella M T Canzoniero, Gianfranco Di Renzo, Pasquale MolinaroAbstract:Abstract Our previous study showed that the environmental neurotoxicant non-dioxin-like polychlorinated biphenyl (PCB)-95 increases RE1-silencing Transcription Factor (REST) expression, which is related to necrosis, but not apoptosis, of neurons. Meanwhile, necroptosis is a type of a programmed necrosis that is positively regulated by receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like (MLKL) and negatively regulated by caspase-8. Here we evaluated whether necroptosis contributes to PCB-95-induced neuronal death through REST up-regulation. Our results demonstrated that in cortical neurons PCB-95 increased RIPK1, RIPK3, and MLKL expression and decreased caspase-8 at the gene and protein level. Furthermore, the RIPK1 inhibitor necrostatin-1 or siRNA-mediated RIPK1, RIPK3 and MLKL expression knockdown significantly reduced PCB-95-induced neuronal death. Intriguingly, PCB-95-induced increases in RIPK1, RIPK3, MLKL expression and decreases in caspase-8 expression were reversed by knockdown of REST expression with a REST-specific siRNA (siREST). Notably, in silico analysis of the rat genome identified a REST consensus sequence in the caspase-8 gene promoter (Casp8-RE1), but not the RIPK1, RIPK3 and MLKL promoters. Interestingly, in PCB-95-treated neurons, REST binding to the Casp8-RE1 sequence increased in parallel with a reduction in its promoter activity, whereas under the same experimental conditions, transfection of siREST or mutation of the Casp8-RE1 sequence blocked PCB-95-induced caspase-8 reduction. Since RIPK1, RIPK3 and MLKL rat genes showed no putative REST binding site, we assessed whether the Transcription Factor cAMP Responsive Element Binding Protein (CREB), which has a consensus sequence in all three genes, affected neuronal death. In neurons treated with PCB-95, CREB protein expression decreased in parallel with a reduction in binding to the RIPK1, RIPK3 and MLKL gene promoter sequence. Furthermore, CREB overexpression was associated with reduced promoter activity of the RIPK1, RIPK3 and MLKL genes. Collectively, these results indicate that PCB-95 was associated with REST-induced necroptotic cell death by increasing RIPK1, RIPK3 and MLKL expression and reducing caspase-8 levels. In addition, since REST is involved in several neurological disorders, therapies that block REST-induced necroptosis could be a new strategy to revert the neurodetrimental effects associated to its overexpression.
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the neurotoxicant pcb 95 by increasing the neuronal Transcriptional repressor rest down regulates caspase 8 and increases ripk1 ripk3 and mlkl expression determining necroptotic neuronal death
Biochemical Pharmacology, 2017Co-Authors: Natascia Guida, Giusy Laudati, Angelo Serani, Paolo Montuori, Luigi Mascolo, Lorella M T Canzoniero, Gianfranco Di Renzo, Pasquale MolinaroAbstract:Abstract Our previous study showed that the environmental neurotoxicant non-dioxin-like polychlorinated biphenyl (PCB)-95 increases RE1-silencing Transcription Factor (REST) expression, which is related to necrosis, but not apoptosis, of neurons. Meanwhile, necroptosis is a type of a programmed necrosis that is positively regulated by receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like (MLKL) and negatively regulated by caspase-8. Here we evaluated whether necroptosis contributes to PCB-95-induced neuronal death through REST up-regulation. Our results demonstrated that in cortical neurons PCB-95 increased RIPK1, RIPK3, and MLKL expression and decreased caspase-8 at the gene and protein level. Furthermore, the RIPK1 inhibitor necrostatin-1 or siRNA-mediated RIPK1, RIPK3 and MLKL expression knockdown significantly reduced PCB-95-induced neuronal death. Intriguingly, PCB-95-induced increases in RIPK1, RIPK3, MLKL expression and decreases in caspase-8 expression were reversed by knockdown of REST expression with a REST-specific siRNA (siREST). Notably, in silico analysis of the rat genome identified a REST consensus sequence in the caspase-8 gene promoter (Casp8-RE1), but not the RIPK1, RIPK3 and MLKL promoters. Interestingly, in PCB-95-treated neurons, REST binding to the Casp8-RE1 sequence increased in parallel with a reduction in its promoter activity, whereas under the same experimental conditions, transfection of siREST or mutation of the Casp8-RE1 sequence blocked PCB-95-induced caspase-8 reduction. Since RIPK1, RIPK3 and MLKL rat genes showed no putative REST binding site, we assessed whether the Transcription Factor cAMP Responsive Element Binding Protein (CREB), which has a consensus sequence in all three genes, affected neuronal death. In neurons treated with PCB-95, CREB protein expression decreased in parallel with a reduction in binding to the RIPK1, RIPK3 and MLKL gene promoter sequence. Furthermore, CREB overexpression was associated with reduced promoter activity of the RIPK1, RIPK3 and MLKL genes. Collectively, these results indicate that PCB-95 was associated with REST-induced necroptotic cell death by increasing RIPK1, RIPK3 and MLKL expression and reducing caspase-8 levels. In addition, since REST is involved in several neurological disorders, therapies that block REST-induced necroptosis could be a new strategy to revert the neurodetrimental effects associated to its overexpression.
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sp3 rest hdac1 hdac2 complex represses and sp1 hif 1 p300 complex activates ncx1 gene Transcription in brain ischemia and in ischemic brain preconditioning by epigenetic mechanism
The Journal of Neuroscience, 2015Co-Authors: Natascia Guida, Giusy Laudati, Luigi Formisano, Valeria Valsecchi, Maria Cantile, Ornella Cuomo, Antonio Vinciguerra, Giuseppe Pignataro, Rossana SirabellaAbstract:The Na+-Ca2+ exchanger 1 (NCX1) is reduced in stroke by the RE1-silencing Transcription Factor (REST), whereas it is increased in ischemic brain preconditioning (PC) by hypoxia-inducible Factor 1 (HIF-1). Because ncx1 brain promoter (ncx1-Br) has five putative consensus sequences, named Sp1A–E, for the specificity protein (Sp) family of Transcription Factors (Sp1–4), we investigated the role of this family in regulating ncx1 Transcription in rat cortical neurons. Here we found that Sp1 is a Transcriptional activator, whereas Sp3 is a Transcriptional repressor of ncx1, and that both bind ncx1-Br in a sequence-specific manner, modulating ncx1 Transcription through the Sp1 sites C–E. Furthermore, by transient middle cerebral artery occlusion (tMCAO) in rats, the Transcriptional repressors Sp3 and REST colocalized with the two histone-deacetylases (HDACs) HDAC1 and HDAC2 on the ncx1-Br, with a consequent hypoacetylation. Contrarily, in PC+tMCAO the Transcriptional activators Sp1 and HIF-1 colocalized with histone acetyltransferase p300 on ncx1-Br with a consequent hyperacetylation. In addition, in neurons silenced with siRNA of NCX1 and subjected to oxygen and glucose deprivation (OGD) (3 h) plus reoxygenation (RX) (24 h), the neuroprotection of Class I HDAC inhibitor MS-275 was counteracted, whereas in neurons overexpressing NCX1 and subjected to ischemic preconditioning (PC+OGD/RX), the neurotoxic effect of p300 inhibitor C646 was prevented. Collectively, these results demonstrate that NCX1 expression is regulated by the Sp3/REST/HDAC1/HDAC2 complex in tMCAO and by the Sp1/HIF-1/p300 complex in PC+tMCAO and that epigenetic intervention, by modulating the acetylation of ncx1-Br, may be a strategy for the development of innovative therapeutic intervention in stroke.
Natascia Guida - One of the best experts on this subject based on the ideXlab platform.
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the neurotoxicant pcb 95 by increasing the neuronal Transcriptional repressor rest down regulates caspase 8 and increases ripk1 ripk3 and mlkl expression determining necroptotic neuronal death
Biochemical Pharmacology, 2017Co-Authors: Natascia Guida, Giusy Laudati, Angelo Serani, Paolo Montuori, Luigi Mascolo, Lorella M T Canzoniero, Gianfranco Di Renzo, Pasquale MolinaroAbstract:Abstract Our previous study showed that the environmental neurotoxicant non-dioxin-like polychlorinated biphenyl (PCB)-95 increases RE1-silencing Transcription Factor (REST) expression, which is related to necrosis, but not apoptosis, of neurons. Meanwhile, necroptosis is a type of a programmed necrosis that is positively regulated by receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like (MLKL) and negatively regulated by caspase-8. Here we evaluated whether necroptosis contributes to PCB-95-induced neuronal death through REST up-regulation. Our results demonstrated that in cortical neurons PCB-95 increased RIPK1, RIPK3, and MLKL expression and decreased caspase-8 at the gene and protein level. Furthermore, the RIPK1 inhibitor necrostatin-1 or siRNA-mediated RIPK1, RIPK3 and MLKL expression knockdown significantly reduced PCB-95-induced neuronal death. Intriguingly, PCB-95-induced increases in RIPK1, RIPK3, MLKL expression and decreases in caspase-8 expression were reversed by knockdown of REST expression with a REST-specific siRNA (siREST). Notably, in silico analysis of the rat genome identified a REST consensus sequence in the caspase-8 gene promoter (Casp8-RE1), but not the RIPK1, RIPK3 and MLKL promoters. Interestingly, in PCB-95-treated neurons, REST binding to the Casp8-RE1 sequence increased in parallel with a reduction in its promoter activity, whereas under the same experimental conditions, transfection of siREST or mutation of the Casp8-RE1 sequence blocked PCB-95-induced caspase-8 reduction. Since RIPK1, RIPK3 and MLKL rat genes showed no putative REST binding site, we assessed whether the Transcription Factor cAMP Responsive Element Binding Protein (CREB), which has a consensus sequence in all three genes, affected neuronal death. In neurons treated with PCB-95, CREB protein expression decreased in parallel with a reduction in binding to the RIPK1, RIPK3 and MLKL gene promoter sequence. Furthermore, CREB overexpression was associated with reduced promoter activity of the RIPK1, RIPK3 and MLKL genes. Collectively, these results indicate that PCB-95 was associated with REST-induced necroptotic cell death by increasing RIPK1, RIPK3 and MLKL expression and reducing caspase-8 levels. In addition, since REST is involved in several neurological disorders, therapies that block REST-induced necroptosis could be a new strategy to revert the neurodetrimental effects associated to its overexpression.
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the neurotoxicant pcb 95 by increasing the neuronal Transcriptional repressor rest down regulates caspase 8 and increases ripk1 ripk3 and mlkl expression determining necroptotic neuronal death
Biochemical Pharmacology, 2017Co-Authors: Natascia Guida, Giusy Laudati, Angelo Serani, Paolo Montuori, Luigi Mascolo, Lorella M T Canzoniero, Gianfranco Di Renzo, Pasquale MolinaroAbstract:Abstract Our previous study showed that the environmental neurotoxicant non-dioxin-like polychlorinated biphenyl (PCB)-95 increases RE1-silencing Transcription Factor (REST) expression, which is related to necrosis, but not apoptosis, of neurons. Meanwhile, necroptosis is a type of a programmed necrosis that is positively regulated by receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like (MLKL) and negatively regulated by caspase-8. Here we evaluated whether necroptosis contributes to PCB-95-induced neuronal death through REST up-regulation. Our results demonstrated that in cortical neurons PCB-95 increased RIPK1, RIPK3, and MLKL expression and decreased caspase-8 at the gene and protein level. Furthermore, the RIPK1 inhibitor necrostatin-1 or siRNA-mediated RIPK1, RIPK3 and MLKL expression knockdown significantly reduced PCB-95-induced neuronal death. Intriguingly, PCB-95-induced increases in RIPK1, RIPK3, MLKL expression and decreases in caspase-8 expression were reversed by knockdown of REST expression with a REST-specific siRNA (siREST). Notably, in silico analysis of the rat genome identified a REST consensus sequence in the caspase-8 gene promoter (Casp8-RE1), but not the RIPK1, RIPK3 and MLKL promoters. Interestingly, in PCB-95-treated neurons, REST binding to the Casp8-RE1 sequence increased in parallel with a reduction in its promoter activity, whereas under the same experimental conditions, transfection of siREST or mutation of the Casp8-RE1 sequence blocked PCB-95-induced caspase-8 reduction. Since RIPK1, RIPK3 and MLKL rat genes showed no putative REST binding site, we assessed whether the Transcription Factor cAMP Responsive Element Binding Protein (CREB), which has a consensus sequence in all three genes, affected neuronal death. In neurons treated with PCB-95, CREB protein expression decreased in parallel with a reduction in binding to the RIPK1, RIPK3 and MLKL gene promoter sequence. Furthermore, CREB overexpression was associated with reduced promoter activity of the RIPK1, RIPK3 and MLKL genes. Collectively, these results indicate that PCB-95 was associated with REST-induced necroptotic cell death by increasing RIPK1, RIPK3 and MLKL expression and reducing caspase-8 levels. In addition, since REST is involved in several neurological disorders, therapies that block REST-induced necroptosis could be a new strategy to revert the neurodetrimental effects associated to its overexpression.
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sp3 rest hdac1 hdac2 complex represses and sp1 hif 1 p300 complex activates ncx1 gene Transcription in brain ischemia and in ischemic brain preconditioning by epigenetic mechanism
The Journal of Neuroscience, 2015Co-Authors: Natascia Guida, Giusy Laudati, Luigi Formisano, Valeria Valsecchi, Maria Cantile, Ornella Cuomo, Antonio Vinciguerra, Giuseppe Pignataro, Rossana SirabellaAbstract:The Na+-Ca2+ exchanger 1 (NCX1) is reduced in stroke by the RE1-silencing Transcription Factor (REST), whereas it is increased in ischemic brain preconditioning (PC) by hypoxia-inducible Factor 1 (HIF-1). Because ncx1 brain promoter (ncx1-Br) has five putative consensus sequences, named Sp1A–E, for the specificity protein (Sp) family of Transcription Factors (Sp1–4), we investigated the role of this family in regulating ncx1 Transcription in rat cortical neurons. Here we found that Sp1 is a Transcriptional activator, whereas Sp3 is a Transcriptional repressor of ncx1, and that both bind ncx1-Br in a sequence-specific manner, modulating ncx1 Transcription through the Sp1 sites C–E. Furthermore, by transient middle cerebral artery occlusion (tMCAO) in rats, the Transcriptional repressors Sp3 and REST colocalized with the two histone-deacetylases (HDACs) HDAC1 and HDAC2 on the ncx1-Br, with a consequent hypoacetylation. Contrarily, in PC+tMCAO the Transcriptional activators Sp1 and HIF-1 colocalized with histone acetyltransferase p300 on ncx1-Br with a consequent hyperacetylation. In addition, in neurons silenced with siRNA of NCX1 and subjected to oxygen and glucose deprivation (OGD) (3 h) plus reoxygenation (RX) (24 h), the neuroprotection of Class I HDAC inhibitor MS-275 was counteracted, whereas in neurons overexpressing NCX1 and subjected to ischemic preconditioning (PC+OGD/RX), the neurotoxic effect of p300 inhibitor C646 was prevented. Collectively, these results demonstrate that NCX1 expression is regulated by the Sp3/REST/HDAC1/HDAC2 complex in tMCAO and by the Sp1/HIF-1/p300 complex in PC+tMCAO and that epigenetic intervention, by modulating the acetylation of ncx1-Br, may be a strategy for the development of innovative therapeutic intervention in stroke.
Fabio Benfenati - One of the best experts on this subject based on the ideXlab platform.
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specificity protein 1 sp1 dependent activation of the synapsin i gene syn1 is modulated by re1 silencing Transcription Factor rest and 5 cytosine phosphoguanine cpg methylation
Journal of Biological Chemistry, 2013Co-Authors: Francesco Paonessa, Shahrzad Latifi, Helena Scarongella, Fabrizia Cesca, Fabio BenfenatiAbstract:Abstract The development and function of the nervous system are directly dependent on a well defined pattern of gene expression. Indeed, perturbation of Transcriptional activity or epigenetic modifications of chromatin can dramatically influence neuronal phenotypes. The phosphoprotein synapsin I (Syn I) plays a crucial role during axonogenesis and synaptogenesis as well as in synaptic transmission and plasticity of mature neurons. Abnormalities in SYN1 gene expression have been linked to important neuropsychiatric disorders, such as epilepsy and autism. SYN1 gene Transcription is suppressed in non-neural tissues by the RE1-silencing Transcription Factor (REST); however, the molecular mechanisms that allow the constitutive expression of this genetic region in neurons have not been clarified yet. Herein we demonstrate that a conserved region of human and mouse SYN1 promoters contains cis-sites for the Transcriptional activator Sp1 in close proximity to REST binding motifs. Through a series of functional assays, we demonstrate a physical interaction of Sp1 on the SYN1 promoter and show that REST directly inhibits Sp1-mediated Transcription, resulting in SYN1 down-regulation. Upon differentiation of neuroblastoma Neuro2a cells, we observe a decrease in endogenous REST and a higher stability of Sp1 on target GC boxes, resulting in an increase of SYN1 Transcription. Moreover, methylation of Sp1 cis-sites in the SYN1 promoter region could provide an additional level of Transcriptional regulation. Our results introduce Sp1 as a fundamental activator of basal SYN1 gene expression, whose activity is modulated by the neural master regulator REST and CpG methylation.
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specificity protein 1 sp1 dependent activation of the synapsin i gene syn1 is modulated by re1 silencing Transcription Factor rest and 5 cytosine phosphoguanine cpg methylation
Journal of Biological Chemistry, 2013Co-Authors: Francesco Paonessa, Shahrzad Latifi, Helena Scarongella, Fabrizia Cesca, Fabio BenfenatiAbstract:The development and function of the nervous system are directly dependent on a well defined pattern of gene expression. Indeed, perturbation of Transcriptional activity or epigenetic modifications of chromatin can dramatically influence neuronal phenotypes. The phosphoprotein synapsin I (Syn I) plays a crucial role during axonogenesis and synaptogenesis as well as in synaptic transmission and plasticity of mature neurons. Abnormalities in SYN1 gene expression have been linked to important neuropsychiatric disorders, such as epilepsy and autism. SYN1 gene Transcription is suppressed in non-neural tissues by the RE1-silencing Transcription Factor (REST); however, the molecular mechanisms that allow the constitutive expression of this genetic region in neurons have not been clarified yet. Herein we demonstrate that a conserved region of human and mouse SYN1 promoters contains cis-sites for the Transcriptional activator Sp1 in close proximity to REST binding motifs. Through a series of functional assays, we demonstrate a physical interaction of Sp1 on the SYN1 promoter and show that REST directly inhibits Sp1-mediated Transcription, resulting in SYN1 down-regulation. Upon differentiation of neuroblastoma Neuro2a cells, we observe a decrease in endogenous REST and a higher stability of Sp1 on target GC boxes, resulting in an increase of SYN1 Transcription. Moreover, methylation of Sp1 cis-sites in the SYN1 promoter region could provide an additional level of Transcriptional regulation. Our results introduce Sp1 as a fundamental activator of basal SYN1 gene expression, whose activity is modulated by the neural master regulator REST and CpG methylation. Background: Syn I plays a key role at presynaptic terminals. Results: Sp1 binds to the SYN1 promoter, activating its Transcription. Conclusion: Sp1 is a novel regulator of SYN1 Transcription, whose activity is inhibited by REST and CpG methylation. Significance: Elucidating the mechanisms underlying basal activation of neuron-specific genes is fundamental to understand brain pathologies, where Transcription is often dysregulated.
Angelo Serani - One of the best experts on this subject based on the ideXlab platform.
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the neurotoxicant pcb 95 by increasing the neuronal Transcriptional repressor rest down regulates caspase 8 and increases ripk1 ripk3 and mlkl expression determining necroptotic neuronal death
Biochemical Pharmacology, 2017Co-Authors: Natascia Guida, Giusy Laudati, Angelo Serani, Paolo Montuori, Luigi Mascolo, Lorella M T Canzoniero, Gianfranco Di Renzo, Pasquale MolinaroAbstract:Abstract Our previous study showed that the environmental neurotoxicant non-dioxin-like polychlorinated biphenyl (PCB)-95 increases RE1-silencing Transcription Factor (REST) expression, which is related to necrosis, but not apoptosis, of neurons. Meanwhile, necroptosis is a type of a programmed necrosis that is positively regulated by receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like (MLKL) and negatively regulated by caspase-8. Here we evaluated whether necroptosis contributes to PCB-95-induced neuronal death through REST up-regulation. Our results demonstrated that in cortical neurons PCB-95 increased RIPK1, RIPK3, and MLKL expression and decreased caspase-8 at the gene and protein level. Furthermore, the RIPK1 inhibitor necrostatin-1 or siRNA-mediated RIPK1, RIPK3 and MLKL expression knockdown significantly reduced PCB-95-induced neuronal death. Intriguingly, PCB-95-induced increases in RIPK1, RIPK3, MLKL expression and decreases in caspase-8 expression were reversed by knockdown of REST expression with a REST-specific siRNA (siREST). Notably, in silico analysis of the rat genome identified a REST consensus sequence in the caspase-8 gene promoter (Casp8-RE1), but not the RIPK1, RIPK3 and MLKL promoters. Interestingly, in PCB-95-treated neurons, REST binding to the Casp8-RE1 sequence increased in parallel with a reduction in its promoter activity, whereas under the same experimental conditions, transfection of siREST or mutation of the Casp8-RE1 sequence blocked PCB-95-induced caspase-8 reduction. Since RIPK1, RIPK3 and MLKL rat genes showed no putative REST binding site, we assessed whether the Transcription Factor cAMP Responsive Element Binding Protein (CREB), which has a consensus sequence in all three genes, affected neuronal death. In neurons treated with PCB-95, CREB protein expression decreased in parallel with a reduction in binding to the RIPK1, RIPK3 and MLKL gene promoter sequence. Furthermore, CREB overexpression was associated with reduced promoter activity of the RIPK1, RIPK3 and MLKL genes. Collectively, these results indicate that PCB-95 was associated with REST-induced necroptotic cell death by increasing RIPK1, RIPK3 and MLKL expression and reducing caspase-8 levels. In addition, since REST is involved in several neurological disorders, therapies that block REST-induced necroptosis could be a new strategy to revert the neurodetrimental effects associated to its overexpression.
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the neurotoxicant pcb 95 by increasing the neuronal Transcriptional repressor rest down regulates caspase 8 and increases ripk1 ripk3 and mlkl expression determining necroptotic neuronal death
Biochemical Pharmacology, 2017Co-Authors: Natascia Guida, Giusy Laudati, Angelo Serani, Paolo Montuori, Luigi Mascolo, Lorella M T Canzoniero, Gianfranco Di Renzo, Pasquale MolinaroAbstract:Abstract Our previous study showed that the environmental neurotoxicant non-dioxin-like polychlorinated biphenyl (PCB)-95 increases RE1-silencing Transcription Factor (REST) expression, which is related to necrosis, but not apoptosis, of neurons. Meanwhile, necroptosis is a type of a programmed necrosis that is positively regulated by receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like (MLKL) and negatively regulated by caspase-8. Here we evaluated whether necroptosis contributes to PCB-95-induced neuronal death through REST up-regulation. Our results demonstrated that in cortical neurons PCB-95 increased RIPK1, RIPK3, and MLKL expression and decreased caspase-8 at the gene and protein level. Furthermore, the RIPK1 inhibitor necrostatin-1 or siRNA-mediated RIPK1, RIPK3 and MLKL expression knockdown significantly reduced PCB-95-induced neuronal death. Intriguingly, PCB-95-induced increases in RIPK1, RIPK3, MLKL expression and decreases in caspase-8 expression were reversed by knockdown of REST expression with a REST-specific siRNA (siREST). Notably, in silico analysis of the rat genome identified a REST consensus sequence in the caspase-8 gene promoter (Casp8-RE1), but not the RIPK1, RIPK3 and MLKL promoters. Interestingly, in PCB-95-treated neurons, REST binding to the Casp8-RE1 sequence increased in parallel with a reduction in its promoter activity, whereas under the same experimental conditions, transfection of siREST or mutation of the Casp8-RE1 sequence blocked PCB-95-induced caspase-8 reduction. Since RIPK1, RIPK3 and MLKL rat genes showed no putative REST binding site, we assessed whether the Transcription Factor cAMP Responsive Element Binding Protein (CREB), which has a consensus sequence in all three genes, affected neuronal death. In neurons treated with PCB-95, CREB protein expression decreased in parallel with a reduction in binding to the RIPK1, RIPK3 and MLKL gene promoter sequence. Furthermore, CREB overexpression was associated with reduced promoter activity of the RIPK1, RIPK3 and MLKL genes. Collectively, these results indicate that PCB-95 was associated with REST-induced necroptotic cell death by increasing RIPK1, RIPK3 and MLKL expression and reducing caspase-8 levels. In addition, since REST is involved in several neurological disorders, therapies that block REST-induced necroptosis could be a new strategy to revert the neurodetrimental effects associated to its overexpression.
