A brain proteomic investigation of rapamycin effects in the Tsc1(+/-) mouse model / H. WESSELING in Molecular Autism, 8 (2017)  

Public ISBD [article]  inMolecular Autism > 8 (2017) . - 41p. Titre : A brain proteomic investigation of rapamycin effects in the Tsc1(+/-) mouse model Type de document : Texte imprimé et/ou numérique Auteurs : H. WESSELING, Auteur ; Y. ELGERSMA, Auteur ; S. BAHN, Auteur Article en page(s) : 41p. Langues : Anglais (eng) Mots-clés : Animal model  Proteomics  Rapamycin  Srm  Tuberous sclerosis Index. décimale : PER Périodiques Résumé : BACKGROUND: Tuberous sclerosis complex (TSC) is a rare monogenic disorder characterized by benign tumors in multiple organs as well as a high prevalence of epilepsy, intellectual disability and autism. TSC is caused by inactivating mutations in the TSC1 or TSC2 genes. Heterozygocity induces hyperactivation of mTOR which can be inhibited by mTOR inhibitors, such as rapamycin, which have proven efficacy in the treatment of TSC-associated symptoms. The aim of the present study was (1) to identify molecular changes associated with social and cognitive deficits in the brain tissue of Tsc1(+/-) mice and (2) to investigate the molecular effects of rapamycin treatment, which has been shown to ameliorate genotype-related behavioural deficits. METHODS: Molecular alterations in the frontal cortex and hippocampus of Tsc1(+/-) and control mice, with or without rapamycin treatment, were investigated. A quantitative mass spectrometry-based shotgun proteomic approach (LC-MS(E)) was employed as an unbiased method to detect changes in protein levels. Changes identified in the initial profiling stage were validated using selected reaction monitoring (SRM). Protein Set Enrichment Analysis was employed to identify dysregulated pathways. RESULTS: LC-MS(E) analysis of Tsc1(+/-) mice and controls (n = 30) identified 51 proteins changed in frontal cortex and 108 in the hippocampus. Bioinformatic analysis combined with targeted proteomic validation revealed several dysregulated molecular pathways. Using targeted assays, proteomic alterations in the hippocampus validated the pathways "myelination", "dendrite," and "oxidative stress", an upregulation of ribosomal proteins and the mTOR kinase. LC-MS(E) analysis was also employed on Tsc1(+/-) and wildtype mice (n = 34) treated with rapamycin or vehicle. Rapamycin treatment exerted a stronger proteomic effect in Tsc1(+/-) mice with significant changes (mainly decreased expression) in 231 and 106 proteins, respectively. The cellular pathways "oxidative stress" and "apoptosis" were found to be affected in Tsc1(+/-) mice and the cellular compartments "myelin sheet" and "neurofilaments" were affected by rapamycin treatment. Thirty-three proteins which were altered in Tsc1(+/-) mice were normalized following rapamycin treatment, amongst them oxidative stress related proteins, myelin-specific and ribosomal proteins. CONCLUSIONS: Molecular changes in the Tsc1(+/-) mouse brain were more prominent in the hippocampus compared to the frontal cortex. Pathways linked to myelination and oxidative stress response were prominently affected and, at least in part, normalized following rapamycin treatment. The results could aid in the identification of novel drug targets for the treatment of cognitive, social and psychiatric symptoms in autism spectrum disorders. Similar pathways have also been implicated in other psychiatric and neurodegenerative disorders and could imply similar disease processes. Thus, the potential efficacy of mTOR inhibitors warrants further investigation not only for autism spectrum disorders but also for other neuropsychiatric and neurodegenerative diseases. En ligne : http://dx.doi.org/10.1186/s13229-017-0151-y Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=331 [article] A brain proteomic investigation of rapamycin effects in the Tsc1(+/-) mouse model [Texte imprimé et/ou numérique] / H. WESSELING, Auteur ; Y. ELGERSMA, Auteur ; S. BAHN, Auteur . - 41p. Langues : Anglais (eng) in Molecular Autism > 8 (2017) . - 41p. Mots-clés : Animal model  Proteomics  Rapamycin  Srm  Tuberous sclerosis Index. décimale : PER Périodiques Résumé : BACKGROUND: Tuberous sclerosis complex (TSC) is a rare monogenic disorder characterized by benign tumors in multiple organs as well as a high prevalence of epilepsy, intellectual disability and autism. TSC is caused by inactivating mutations in the TSC1 or TSC2 genes. Heterozygocity induces hyperactivation of mTOR which can be inhibited by mTOR inhibitors, such as rapamycin, which have proven efficacy in the treatment of TSC-associated symptoms. The aim of the present study was (1) to identify molecular changes associated with social and cognitive deficits in the brain tissue of Tsc1(+/-) mice and (2) to investigate the molecular effects of rapamycin treatment, which has been shown to ameliorate genotype-related behavioural deficits. METHODS: Molecular alterations in the frontal cortex and hippocampus of Tsc1(+/-) and control mice, with or without rapamycin treatment, were investigated. A quantitative mass spectrometry-based shotgun proteomic approach (LC-MS(E)) was employed as an unbiased method to detect changes in protein levels. Changes identified in the initial profiling stage were validated using selected reaction monitoring (SRM). Protein Set Enrichment Analysis was employed to identify dysregulated pathways. RESULTS: LC-MS(E) analysis of Tsc1(+/-) mice and controls (n = 30) identified 51 proteins changed in frontal cortex and 108 in the hippocampus. Bioinformatic analysis combined with targeted proteomic validation revealed several dysregulated molecular pathways. Using targeted assays, proteomic alterations in the hippocampus validated the pathways "myelination", "dendrite," and "oxidative stress", an upregulation of ribosomal proteins and the mTOR kinase. LC-MS(E) analysis was also employed on Tsc1(+/-) and wildtype mice (n = 34) treated with rapamycin or vehicle. Rapamycin treatment exerted a stronger proteomic effect in Tsc1(+/-) mice with significant changes (mainly decreased expression) in 231 and 106 proteins, respectively. The cellular pathways "oxidative stress" and "apoptosis" were found to be affected in Tsc1(+/-) mice and the cellular compartments "myelin sheet" and "neurofilaments" were affected by rapamycin treatment. Thirty-three proteins which were altered in Tsc1(+/-) mice were normalized following rapamycin treatment, amongst them oxidative stress related proteins, myelin-specific and ribosomal proteins. CONCLUSIONS: Molecular changes in the Tsc1(+/-) mouse brain were more prominent in the hippocampus compared to the frontal cortex. Pathways linked to myelination and oxidative stress response were prominently affected and, at least in part, normalized following rapamycin treatment. The results could aid in the identification of novel drug targets for the treatment of cognitive, social and psychiatric symptoms in autism spectrum disorders. Similar pathways have also been implicated in other psychiatric and neurodegenerative disorders and could imply similar disease processes. Thus, the potential efficacy of mTOR inhibitors warrants further investigation not only for autism spectrum disorders but also for other neuropsychiatric and neurodegenerative diseases. En ligne : http://dx.doi.org/10.1186/s13229-017-0151-y Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=331

Synaptic vesicle dynamic changes in a model of fragile X / Jantine A.C. BROEK in Molecular Autism, 7 (2016)  

Public ISBD [article]  inMolecular Autism > 7 (2016) . - 17p. Titre : Synaptic vesicle dynamic changes in a model of fragile X Type de document : Texte imprimé et/ou numérique Auteurs : Jantine A.C. BROEK, Auteur ; Z. LIN, Auteur ; H. M. DE GRUITER, Auteur ; H. VAN 'T SPIJKER, Auteur ; E. D. HAASDIJK, Auteur ; David COX, Auteur ; S. OZCAN, Auteur ; G. W. A. VAN CAPPELLEN, Auteur ; A. B. HOUTSMULLER, Auteur ; R. WILLEMSEN, Auteur ; C. I. DE ZEEUW, Auteur ; S. BAHN, Auteur Article en page(s) : 17p. Langues : Anglais (eng) Mots-clés : Animals  Animals, Congenic  Cells, Cultured  Cerebellum/pathology/physiopathology  Fluorescent Dyes  Fragile X Mental Retardation Protein/genetics/physiology  Fragile X Syndrome/genetics/metabolism/physiopathology  Hippocampus/pathology/physiopathology  Intravital Microscopy  Male  Mass Spectrometry/methods  Mice  Mice, Inbred C57BL  Mice, Knockout  Mice, Neurologic Mutants  Microscopy, Electron  Models, Animal  Nerve Tissue Proteins/analysis  Presynaptic Terminals/secretion  Proteome  Purkinje Cells/physiology/ultrastructure  Pyridinium Compounds  Quaternary Ammonium Compounds  Signal Transduction  Synaptic Transmission  Synaptic Vesicles/metabolism  Synaptosomes/metabolism  Electron microscopy  Fragile X syndrome (FXS)  Mass spectrometry (MS)  Quantitative live-cell imaging Index. décimale : PER Périodiques Résumé : BACKGROUND: Fragile X syndrome (FXS) is a single-gene disorder that is the most common heritable cause of intellectual disability and the most frequent monogenic cause of autism spectrum disorders (ASD). FXS is caused by an expansion of trinucleotide repeats in the promoter region of the fragile X mental retardation gene (Fmr1). This leads to a lack of fragile X mental retardation protein (FMRP), which regulates translation of a wide range of messenger RNAs (mRNAs). The extent of expression level alterations of synaptic proteins affected by FMRP loss and their consequences on synaptic dynamics in FXS has not been fully investigated. METHODS: Here, we used an Fmr1 knockout (KO) mouse model to investigate the molecular mechanisms underlying FXS by monitoring protein expression changes using shotgun label-free liquid-chromatography mass spectrometry (LC-MS(E)) in brain tissue and synaptosome fractions. FXS-associated candidate proteins were validated using selected reaction monitoring (SRM) in synaptosome fractions for targeted protein quantification. Furthermore, functional alterations in synaptic release and dynamics were evaluated using live-cell imaging, and interpretation of synaptic dynamics differences was investigated using electron microscopy. RESULTS: Key findings relate to altered levels of proteins involved in GABA-signalling, especially in the cerebellum. Further exploration using microscopy studies found reduced synaptic vesicle unloading of hippocampal neurons and increased vesicle unloading in cerebellar neurons, which suggests a general decrease of synaptic transmission. CONCLUSIONS: Our findings suggest that FMRP is a regulator of synaptic vesicle dynamics, which supports the role of FMRP in presynaptic functions. Taken together, these studies provide novel insights into the molecular changes associated with FXS. En ligne : http://dx.doi.org/10.1186/s13229-016-0080-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=328 [article] Synaptic vesicle dynamic changes in a model of fragile X [Texte imprimé et/ou numérique] / Jantine A.C. BROEK, Auteur ; Z. LIN, Auteur ; H. M. DE GRUITER, Auteur ; H. VAN 'T SPIJKER, Auteur ; E. D. HAASDIJK, Auteur ; David COX, Auteur ; S. OZCAN, Auteur ; G. W. A. VAN CAPPELLEN, Auteur ; A. B. HOUTSMULLER, Auteur ; R. WILLEMSEN, Auteur ; C. I. DE ZEEUW, Auteur ; S. BAHN, Auteur . - 17p. Langues : Anglais (eng) in Molecular Autism > 7 (2016) . - 17p. Mots-clés : Animals  Animals, Congenic  Cells, Cultured  Cerebellum/pathology/physiopathology  Fluorescent Dyes  Fragile X Mental Retardation Protein/genetics/physiology  Fragile X Syndrome/genetics/metabolism/physiopathology  Hippocampus/pathology/physiopathology  Intravital Microscopy  Male  Mass Spectrometry/methods  Mice  Mice, Inbred C57BL  Mice, Knockout  Mice, Neurologic Mutants  Microscopy, Electron  Models, Animal  Nerve Tissue Proteins/analysis  Presynaptic Terminals/secretion  Proteome  Purkinje Cells/physiology/ultrastructure  Pyridinium Compounds  Quaternary Ammonium Compounds  Signal Transduction  Synaptic Transmission  Synaptic Vesicles/metabolism  Synaptosomes/metabolism  Electron microscopy  Fragile X syndrome (FXS)  Mass spectrometry (MS)  Quantitative live-cell imaging Index. décimale : PER Périodiques Résumé : BACKGROUND: Fragile X syndrome (FXS) is a single-gene disorder that is the most common heritable cause of intellectual disability and the most frequent monogenic cause of autism spectrum disorders (ASD). FXS is caused by an expansion of trinucleotide repeats in the promoter region of the fragile X mental retardation gene (Fmr1). This leads to a lack of fragile X mental retardation protein (FMRP), which regulates translation of a wide range of messenger RNAs (mRNAs). The extent of expression level alterations of synaptic proteins affected by FMRP loss and their consequences on synaptic dynamics in FXS has not been fully investigated. METHODS: Here, we used an Fmr1 knockout (KO) mouse model to investigate the molecular mechanisms underlying FXS by monitoring protein expression changes using shotgun label-free liquid-chromatography mass spectrometry (LC-MS(E)) in brain tissue and synaptosome fractions. FXS-associated candidate proteins were validated using selected reaction monitoring (SRM) in synaptosome fractions for targeted protein quantification. Furthermore, functional alterations in synaptic release and dynamics were evaluated using live-cell imaging, and interpretation of synaptic dynamics differences was investigated using electron microscopy. RESULTS: Key findings relate to altered levels of proteins involved in GABA-signalling, especially in the cerebellum. Further exploration using microscopy studies found reduced synaptic vesicle unloading of hippocampal neurons and increased vesicle unloading in cerebellar neurons, which suggests a general decrease of synaptic transmission. CONCLUSIONS: Our findings suggest that FMRP is a regulator of synaptic vesicle dynamics, which supports the role of FMRP in presynaptic functions. Taken together, these studies provide novel insights into the molecular changes associated with FXS. En ligne : http://dx.doi.org/10.1186/s13229-016-0080-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=328

---

1 (1 - 2 / 2)