Project description:Abnormal trinucleotide expansions cause rare disorders that compromise quality of life and, in some cases, life span. In particular, the expansions of the CGG-repeats stretch at the 5'-UTR of the Fragile X Mental Retardation 1 (FMR1) gene have pleiotropic effects that lead to a variety of Fragile X-associated syndromes: the neurodevelopmental Fragile X syndrome (FXS) in children, the late-onset neurodegenerative disorder Fragile X-associated tremor-ataxia syndrome (FXTAS) that mainly affects adult men, the Fragile X-associated primary ovarian insufficiency (FXPOI) in adult women, and a variety of psychiatric and affective disorders that are under the term of Fragile X-associated neuropsychiatric disorders (FXAND). There have been intensive attempts to identify reliable peripheral biomarkers to assess disease progression and onset of specific pathological traits. We profiled the miRNAs content of plasma from premutation carriers and controls. Understanding the association between molecular pathogenesis and biomarkers dynamics will improve effective prognosis and clinical management of CGG-expansion carriers
Project description:Fragile X premutation carriers (fXPC) of the CGG expansion in the 5M-bM-^@M-^Y-UTR of the fragile X mental retardation 1 (FMR1) gene are at high risk of Fragile X Tremor/Ataxia Syndrome (FXTAS), and females might undergo Premature Ovarian Failure (POF1). We have evaluated the peripheral blood gene expression profiles of fXPC and detected a strong deregulation of genes enriched in FXTAS-relevant biological pathways, including inflammation, and neuronal homeostasis and survival. More than 30% of differentially expressed correspond to long non-coding RNAs (lncRNAs). Several deregulated genes (CASP3, DFFA, APP, AKT1, COX6C, COX7B, SOD1, RNF10, HDAC5, ATXN7, ATXN3 and EAP1) were validated in brain samples of a mouse model of FXTAS and in neuronal cells expressing the expanded FMR1 5M-bM-^@M-^Y-UTR. One of the validated genes is the early at menopause 1 (EAP1) gene. We confirmed the EAP1 deregulation both in male and female fXPC. Down-regulation was stronger in female fXPC with POF1 compared with female fXPC without POF1. Increased levels of FMR1 mRNA were detected in all brain areas of the CGG-KI mouse model. EAP1 was significantly downregulated in the brainstem and cerebellum of the KI mouse, suggesting that EAP1 levels in certain brain areas could contribute to POF in this model. All together, these results suggest that gene expression profiling in blood of fXPC reflects changes in the brain transcriptome that may underlie neuropathological aspects in FXTAS and of POF. In the study presented here, we have 5 control samples plus one biological replicate and 9 patients with CGG expansions in the 5'UTR of the FMR1 gene (being premutation carriers)
Project description:Fragile X premutation carriers (fXPC) of the CGG expansion in the 5M-bM-^@M-^Y-UTR of the fragile X mental retardation 1 (FMR1) gene are at high risk of Fragile X Tremor/Ataxia Syndrome (FXTAS), and females might undergo Premature Ovarian Failure (POF1). We have evaluated the peripheral blood gene expression profiles of fXPC and detected a strong deregulation of genes enriched in FXTAS-relevant biological pathways, including inflammation, and neuronal homeostasis and survival. More than 30% of differentially expressed correspond to long non-coding RNAs (lncRNAs). Several deregulated genes (CASP3, DFFA, APP, AKT1, COX6C, COX7B, SOD1, RNF10, HDAC5, ATXN7, ATXN3 and EAP1) were validated in brain samples of a mouse model of FXTAS and in neuronal cells expressing the expanded FMR1 5M-bM-^@M-^Y-UTR. One of the validated genes is the early at menopause 1 (EAP1) gene. We confirmed the EAP1 deregulation both in male and female fXPC. Down-regulation was stronger in female fXPC with POF1 compared with female fXPC without POF1. Increased levels of FMR1 mRNA were detected in all brain areas of the CGG-KI mouse model. EAP1 was significantly downregulated in the brainstem and cerebellum of the KI mouse, suggesting that EAP1 levels in certain brain areas could contribute to POF in this model. All together, these results suggest that gene expression profiling in blood of fXPC reflects changes in the brain transcriptome that may underlie neuropathological aspects in FXTAS and of POF. In the study presented here, we have 6 biological replicats for the Mock conditions, 6 biological replicates for the expression of the wild type FMR1 5'UTR, 6 biological replicates for the expression of the mutant FMR1 5'UTR and 6 biological replicates for the overexpression of the muatnt FMR1 5'UTR.
Project description:Fragile X premutation carriers (fXPC) of the CGG expansion in the 5’-UTR of the fragile X mental retardation 1 (FMR1) gene are at high risk of Fragile X Tremor/Ataxia Syndrome (FXTAS), and females might undergo Premature Ovarian Failure (POF1). We have evaluated the peripheral blood gene expression profiles of fXPC and detected a strong deregulation of genes enriched in FXTAS-relevant biological pathways, including inflammation, and neuronal homeostasis and survival. More than 30% of differentially expressed correspond to long non-coding RNAs (lncRNAs). Several deregulated genes (CASP3, DFFA, APP, AKT1, COX6C, COX7B, SOD1, RNF10, HDAC5, ATXN7, ATXN3 and EAP1) were validated in brain samples of a mouse model of FXTAS and in neuronal cells expressing the expanded FMR1 5’-UTR. One of the validated genes is the early at menopause 1 (EAP1) gene. We confirmed the EAP1 deregulation both in male and female fXPC. Down-regulation was stronger in female fXPC with POF1 compared with female fXPC without POF1. Increased levels of FMR1 mRNA were detected in all brain areas of the CGG-KI mouse model. EAP1 was significantly downregulated in the brainstem and cerebellum of the KI mouse, suggesting that EAP1 levels in certain brain areas could contribute to POF in this model. All together, these results suggest that gene expression profiling in blood of fXPC reflects changes in the brain transcriptome that may underlie neuropathological aspects in FXTAS and of POF.
Project description:Fragile X premutation carriers (fXPC) of the CGG expansion in the 5’-UTR of the fragile X mental retardation 1 (FMR1) gene are at high risk of Fragile X Tremor/Ataxia Syndrome (FXTAS), and females might undergo Premature Ovarian Failure (POF1). We have evaluated the peripheral blood gene expression profiles of fXPC and detected a strong deregulation of genes enriched in FXTAS-relevant biological pathways, including inflammation, and neuronal homeostasis and survival. More than 30% of differentially expressed correspond to long non-coding RNAs (lncRNAs). Several deregulated genes (CASP3, DFFA, APP, AKT1, COX6C, COX7B, SOD1, RNF10, HDAC5, ATXN7, ATXN3 and EAP1) were validated in brain samples of a mouse model of FXTAS and in neuronal cells expressing the expanded FMR1 5’-UTR. One of the validated genes is the early at menopause 1 (EAP1) gene. We confirmed the EAP1 deregulation both in male and female fXPC. Down-regulation was stronger in female fXPC with POF1 compared with female fXPC without POF1. Increased levels of FMR1 mRNA were detected in all brain areas of the CGG-KI mouse model. EAP1 was significantly downregulated in the brainstem and cerebellum of the KI mouse, suggesting that EAP1 levels in certain brain areas could contribute to POF in this model. All together, these results suggest that gene expression profiling in blood of fXPC reflects changes in the brain transcriptome that may underlie neuropathological aspects in FXTAS and of POF.
Project description:Fragile-X Syndrome (FXS) is a multi-organ disease leading to mental retardation, macro-orchidism in males, and premature ovarian insufficiency in female carriers. FXS is also a prominent monogenic disease associated with autism spectrum disorders (ASD). FXS is typically caused by the loss of FRAGILE X-MENTAL RETARDATION 1 (FMR1) expression, which encodes for the RNA-binding protein (RBP), FMR1 (or FMRP). We report the discovery of the RNA recognition elements (RREs), binding sites, and mRNA targets for wild-type and I304N mutant FMRP isoforms as well as its paralogs, FXR1 and FXR2. RRE frequency, ratio, and distribution determine target mRNA association with FMRP. Among highly-enriched targets, we identified many genes involved in ASD and demonstrate that FMRP can affect their protein levels in cell culture, mice, and human brain. Unexpectedly, we discovered that these targets are also dysregulated in Fmr1-/- mouse ovaries, showing signs of premature follicular overdevelopment. These results indicate that FMRP targets shared signaling pathways across different cellular contexts. As it is become increasingly appreciated that signaling pathways are important to FXS and ASD, our results here provide an invaluable molecular guide towards the pursuit of novel therapeutic targets for these devastating neurological disorders. The mRNA profile of RNA recovered from FLAG-antibody immunoprecipitated FMRP was compared to the mRNA profile of the starting lysate material.
Project description:Aberrant alternative splicing of mRNAs results in dysregulated gene expression in multiple neurological disorders. Here we show that hundreds of mRNAs are incorrectly expressed and spliced in white blood cells and brain tissue of individuals with fragile X syndrome (FXS). Surprisingly, the FMR1 (Fragile X Messenger Ribonucleoprotein 1) gene is transcribed in >70% of the FXS tissues. In all FMR1 expressing FXS tissues, FMR1 RNA itself is mis-spliced in a CGG expansion-dependent manner to generate the little-known FMR1-217 RNA isoform, which is comprised of FMR1 exon 1 and a pseudo-exon in intron 1. FMR1-217 is also expressed in FXS premutation carrier-derived skin fibroblasts and brain tissue. We show that in cells aberrantly expressing mis-spliced FMR1, antisense oligonucleotide (ASO) treatment reduces FMR1-217, rescues full-length FMR1 RNA, and restores FMRP (Fragile X Messenger RibonucleoProtein) to normal levels. Notably, FMR1 gene reactivation in transcriptionally silent FXS cells using 5-aza-2′-deoxycytidine (5-AzadC), which prevents DNA methylation, increases FMR1-217 RNA levels but not FMRP. ASO treatment of cells prior to 5-AzadC application rescues full-length FMR1 expression and restores FMRP. These findings indicate that mis-regulated RNA processing events in blood could serve as potent biomarkers for FXS and that in those individuals expressing FMR1-217, ASO treatment may offer a new therapeutic approach to mitigate the disorder.
Project description:Aberrant alternative splicing of mRNAs results in dysregulated gene expression in multiple neurological disorders. Here we show that hundreds of mRNAs are incorrectly expressed and spliced in white blood cells and brain tissue of individuals with fragile X syndrome (FXS). Surprisingly, the FMR1 (Fragile X Messenger Ribonucleoprotein 1) gene is transcribed in >70% of the FXS tissues. In all FMR1 expressing FXS tissues, FMR1 RNA itself is mis-spliced in a CGG expansion-dependent manner to generate the little-known FMR1-217 RNA isoform, which is comprised of FMR1 exon 1 and a pseudo-exon in intron 1. FMR1-217 is also expressed in FXS premutation carrier-derived skin fibroblasts and brain tissue. We show that in cells aberrantly expressing mis-spliced FMR1, antisense oligonucleotide (ASO) treatment reduces FMR1-217, rescues full-length FMR1 RNA, and restores FMRP (Fragile X Messenger RibonucleoProtein) to normal levels. Notably, FMR1 gene reactivation in transcriptionally silent FXS cells using 5-aza-2′-deoxycytidine (5-AzadC), which prevents DNA methylation, increases FMR1-217 RNA levels but not FMRP. ASO treatment of cells prior to 5-AzadC application rescues full-length FMR1 expression and restores FMRP. These findings indicate that mis-regulated RNA processing events in blood could serve as potent biomarkers for FXS and that in those individuals expressing FMR1-217, ASO treatment may offer a new therapeutic approach to mitigate the disorder.
Project description:Fragile-X Syndrome (FXS) is a multi-organ disease leading to mental retardation, macro-orchidism in males, and premature ovarian insufficiency in female carriers. FXS is also a prominent monogenic disease associated with autism spectrum disorders (ASD). FXS is typically caused by the loss of FRAGILE X-MENTAL RETARDATION 1 (FMR1) expression, which encodes for the RNA-binding protein (RBP), FMR1 (or FMRP). We report the discovery of the RNA recognition elements (RREs), binding sites, and mRNA targets for wild-type and I304N mutant FMRP isoforms as well as its paralogs, FXR1 and FXR2. RRE frequency, ratio, and distribution determine target mRNA association with FMRP. Among highly-enriched targets, we identified many genes involved in ASD and demonstrate that FMRP can affect their protein levels in cell culture, mice, and human brain. Unexpectedly, we discovered that these targets are also dysregulated in Fmr1-/- mouse ovaries, showing signs of premature follicular overdevelopment. These results indicate that FMRP targets shared signaling pathways across different cellular contexts. As it is become increasingly appreciated that signaling pathways are important to FXS and ASD, our results here provide an invaluable molecular guide towards the pursuit of novel therapeutic targets for these devastating neurological disorders. PAR-CLIP profiling for wild-type and I304N mutant FMRP isoforms as well as paralogs, FXR1 and FXR2.