Project description:Dendritic-cell (DC) maturation involves substantial remodeling of their gene-expression program. Most research has focused on inducible gene-expression networks promoting the acquisition of new functions, such as cytokine production and enhanced T-cell-stimulatory capacity. In contrast, mechanisms that modulate DC-function by inducing gene silencing remain poorly understood. Here we describe a novel primary epigenetic-silencing response that makes major contributions to the DC-maturation process. The repressed genes function in pivotal processes - including antigen-presentation, extracellular-signal detection, signal-transduction and lipid-mediator biosynthesis - underscoring the central contribution of the silencing mechanism to rapid reshaping of DC-function. Interestingly, promoters of the repressed genes exhibit a surprisingly high frequency of PU.1-occupied sites, suggesting a novel role for this transcription factor in marking genes poised for inducible repression Analysis of PU.1 binding sites in mo-DC
Project description:Dendritic-cell (DC) maturation involves substantial remodeling of their gene-expression program. Most research has focused on inducible gene-expression networks promoting the acquisition of new functions, such as cytokine production and enhanced T-cell-stimulatory capacity. In contrast, mechanisms that modulate DC-function by inducing gene silencing remain poorly understood. Here we describe a novel primary epigenetic-silencing response that makes major contributions to the DC-maturation process. The repressed genes function in pivotal processes - including antigen-presentation, extracellular-signal detection, signal-transduction and lipid-mediator biosynthesis - underscoring the central contribution of the silencing mechanism to rapid reshaping of DC-function. Interestingly, promoters of the repressed genes exhibit a surprisingly high frequency of PU.1-occupied sites, suggesting a novel role for this transcription factor in marking genes poised for inducible repression
Project description:Dendritic-cell (DC) maturation involves substantial remodeling of their gene-expression program. Most research has focused on inducible gene-expression networks promoting the acquisition of new functions, such as cytokine production and enhanced T-cell-stimulatory capacity. In contrast, mechanisms that modulate DC-function by inducing gene silencing remain poorly understood. Here we describe a novel primary epigenetic-silencing response that makes major contributions to the DC-maturation process. The repressed genes function in pivotal processes - including antigen-presentation, extracellular-signal detection, signal-transduction and lipid-mediator biosynthesis - underscoring the central contribution of the silencing mechanism to rapid reshaping of DC-function. Interestingly, promoters of the repressed genes exhibit a surprisingly high frequency of PU.1-occupied sites, suggesting a novel role for this transcription factor in marking genes poised for inducible repression
Project description:Dendritic-cell (DC) maturation involves substantial remodeling of their gene-expression program. Most research has focused on inducible gene-expression networks promoting the acquisition of new functions, such as cytokine production and enhanced T-cell-stimulatory capacity. In contrast, mechanisms that modulate DC-function by inducing gene silencing remain poorly understood. Here we describe a novel primary epigenetic-silencing response that makes major contributions to the DC-maturation process. The repressed genes function in pivotal processes - including antigen-presentation, extracellular-signal detection, signal-transduction and lipid-mediator biosynthesis - underscoring the central contribution of the silencing mechanism to rapid reshaping of DC-function. Interestingly, promoters of the repressed genes exhibit a surprisingly high frequency of PU.1-occupied sites, suggesting a novel role for this transcription factor in marking genes poised for inducible repression
Project description:<p>Small cell carcinoma of the ovary-hypercalcemic type (SCCOHT) is a rare and aggressive form of ovarian cancer afflicting young women at a median age of 24 years. SCCOHTs are characterized by loss of protein expression of SWI/SNF chromatin remodeling ATPases SMARCA4 and SMARCA2 through mutation and epigenetic silencing, respectively. This study aims to establish gene expression profiles of this cancer through RNA-Seq of four pathologically confirmed cases of SCCOHT tumors.</p>
Project description:Fragile X syndrome (FXS) is a disease of pathologic epigenetic silencing induced by RNA. In FXS, an expanded CGG-repeat tract in the FMR1 gene induces epigenetic silencing during embryogenesis. FMR1 silencing can be reversed with 5-aza-deoxyctidine (5-aza-dC), a nonspecific epigenetic reactivator; however, continuous administration of 5-aza-dC is problematic due to its toxicity. We describe an approach to restore FMR1 expression in FXS neurons by transient treatment with 5-aza-dC, followed by treatment with 2HE-5NMe, which binds the CGG-repeat expansion in the FMR1 mRNA and blocks the resilencing of the FMR1 gene after withdrawal of 5-aza-dC. Genome-wide profiling of histone marks shows that 2HE-5Nme maintains FMR1 in a reactivated state. FMR1 reactivation in neurons results in re-expression of FMRP and reversal of FXS-associated dendritic spine defects. These results demonstrate that an RNA-binding small molecule can achieve gene-specific epigenetic control, and provide an approach for restoration of FMRP in FXS neurons.
Project description:Fragile X syndrome (FXS) is a disease of pathologic epigenetic silencing induced by RNA. In FXS, an expanded CGG-repeat tract in the FMR1 gene induces epigenetic silencing during embryogenesis. FMR1 silencing can be reversed with 5-aza-deoxyctidine (5-aza-dC), a nonspecific epigenetic reactivator; however, continuous administration of 5-aza-dC is problematic due to its toxicity. We describe an approach to restore FMR1 expression in FXS neurons by transient treatment with 5-aza-dC, followed by treatment with 2HE-5NMe, which binds the CGG-repeat expansion in the FMR1 mRNA and blocks the resilencing of the FMR1 gene after withdrawal of 5-aza-dC. Genome-wide profiling of histone marks shows that 2HE-5Nme maintains FMR1 in a reactivated state. FMR1 reactivation in neurons results in re-expression of FMRP and reversal of FXS-associated dendritic spine defects. These results demonstrate that an RNA-binding small molecule can achieve gene-specific epigenetic control, and provide an approach for restoration of FMRP in FXS neurons.