6 recherche sur le mot-clé 'Neurons/metabolism'

Shank3 deficiency elicits autistic-like behaviors by activating p38? in hypothalamic AgRP neurons / Shanshan WU in Molecular Autism, 15 (2024)  

Public ISBD [article]  inMolecular Autism > 15 (2024) . - 14p. Titre : Shank3 deficiency elicits autistic-like behaviors by activating p38? in hypothalamic AgRP neurons Type de document : Texte imprimé et/ou numérique Auteurs : Shanshan WU, Auteur ; Jing WANG, Auteur ; Zicheng ZHANG, Auteur ; Xinchen JIN, Auteur ; Yang XU, Auteur ; Youwen SI, Auteur ; Yixiao LIANG, Auteur ; Yueping GE, Auteur ; Huidong ZHAN, Auteur ; Li PENG, Auteur ; Wenkai BI, Auteur ; Dandan LUO, Auteur ; Mengzhu LI, Auteur ; Bo MENG, Auteur ; Qingbo GUAN, Auteur ; Jiajun ZHAO, Auteur ; Ling GAO, Auteur ; Zhao HE, Auteur Article en page(s) : 14p. Langues : Anglais (eng) Mots-clés : Animals  Mice  Agouti-Related Protein/genetics/metabolism  Arcuate Nucleus of Hypothalamus/metabolism  Autistic Disorder/genetics/metabolism  Hypothalamus/metabolism  Microfilament Proteins/metabolism  Nerve Tissue Proteins/genetics/metabolism  Neurons/metabolism  Mitogen-Activated Protein Kinase 14/metabolism  AgRP  Autism  Shank3  Sociability  Stereotypic behavior  p38? Index. décimale : PER Périodiques Résumé : BACKGROUND: SH3 and multiple ankyrin repeat domains protein 3 (SHANK3) monogenic mutations or deficiency leads to excessive stereotypic behavior and impaired sociability, which frequently occur in autism cases. To date, the underlying mechanisms by which Shank3 mutation or deletion causes autism and the part of the brain in which Shank3 mutation leads to the autistic phenotypes are understudied. The hypothalamus is associated with stereotypic behavior and sociability. p38?, a mediator of inflammatory responses in the brain, has been postulated as a potential gene for certain cases of autism occurrence. However, it is unclear whether hypothalamus and p38? are involved in the development of autism caused by Shank3 mutations or deficiency. METHODS: Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and immunoblotting were used to assess alternated signaling pathways in the hypothalamus of Shank3 knockout (Shank3(-/-)) mice. Home-Cage real-time monitoring test was performed to record stereotypic behavior and three-chamber test was used to monitor the sociability of mice. Adeno-associated viruses 9 (AAV9) were used to express p38? in the arcuate nucleus (ARC) or agouti-related peptide (AgRP) neurons. D176A and F327S mutations expressed constitutively active p38?. T180A and Y182F mutations expressed inactive p38?. RESULTS: We found that Shank3 controls stereotypic behavior and sociability by regulating p38? activity in AgRP neurons. Phosphorylated p38 level in hypothalamus is significantly enhanced in Shank3(-/-) mice. Consistently, overexpression of p38? in ARC or AgRP neurons elicits excessive stereotypic behavior and impairs sociability in wild-type (WT) mice. Notably, activated p38? in AgRP neurons increases stereotypic behavior and impairs sociability. Conversely, inactivated p38? in AgRP neurons significantly ameliorates autistic behaviors of Shank3(-/-) mice. In contrast, activated p38? in pro-opiomelanocortin (POMC) neurons does not affect stereotypic behavior and sociability in mice. LIMITATIONS: We demonstrated that SHANK3 regulates the phosphorylated p38 level in the hypothalamus and inactivated p38? in AgRP neurons significantly ameliorates autistic behaviors of Shank3(-/-) mice. However, we did not clarify the biochemical mechanism of SHANK3 inhibiting p38? in AgRP neurons. CONCLUSIONS: These results demonstrate that the Shank3 deficiency caused autistic-like behaviors by activating p38? signaling in AgRP neurons, suggesting that p38? signaling in AgRP neurons is a potential therapeutic target for Shank3 mutant-related autism. En ligne : https://dx.doi.org/10.1186/s13229-024-00595-4 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=538 [article] Shank3 deficiency elicits autistic-like behaviors by activating p38? in hypothalamic AgRP neurons [Texte imprimé et/ou numérique] / Shanshan WU, Auteur ; Jing WANG, Auteur ; Zicheng ZHANG, Auteur ; Xinchen JIN, Auteur ; Yang XU, Auteur ; Youwen SI, Auteur ; Yixiao LIANG, Auteur ; Yueping GE, Auteur ; Huidong ZHAN, Auteur ; Li PENG, Auteur ; Wenkai BI, Auteur ; Dandan LUO, Auteur ; Mengzhu LI, Auteur ; Bo MENG, Auteur ; Qingbo GUAN, Auteur ; Jiajun ZHAO, Auteur ; Ling GAO, Auteur ; Zhao HE, Auteur . - 14p. Langues : Anglais (eng) in Molecular Autism > 15 (2024) . - 14p. Mots-clés : Animals  Mice  Agouti-Related Protein/genetics/metabolism  Arcuate Nucleus of Hypothalamus/metabolism  Autistic Disorder/genetics/metabolism  Hypothalamus/metabolism  Microfilament Proteins/metabolism  Nerve Tissue Proteins/genetics/metabolism  Neurons/metabolism  Mitogen-Activated Protein Kinase 14/metabolism  AgRP  Autism  Shank3  Sociability  Stereotypic behavior  p38? Index. décimale : PER Périodiques Résumé : BACKGROUND: SH3 and multiple ankyrin repeat domains protein 3 (SHANK3) monogenic mutations or deficiency leads to excessive stereotypic behavior and impaired sociability, which frequently occur in autism cases. To date, the underlying mechanisms by which Shank3 mutation or deletion causes autism and the part of the brain in which Shank3 mutation leads to the autistic phenotypes are understudied. The hypothalamus is associated with stereotypic behavior and sociability. p38?, a mediator of inflammatory responses in the brain, has been postulated as a potential gene for certain cases of autism occurrence. However, it is unclear whether hypothalamus and p38? are involved in the development of autism caused by Shank3 mutations or deficiency. METHODS: Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and immunoblotting were used to assess alternated signaling pathways in the hypothalamus of Shank3 knockout (Shank3(-/-)) mice. Home-Cage real-time monitoring test was performed to record stereotypic behavior and three-chamber test was used to monitor the sociability of mice. Adeno-associated viruses 9 (AAV9) were used to express p38? in the arcuate nucleus (ARC) or agouti-related peptide (AgRP) neurons. D176A and F327S mutations expressed constitutively active p38?. T180A and Y182F mutations expressed inactive p38?. RESULTS: We found that Shank3 controls stereotypic behavior and sociability by regulating p38? activity in AgRP neurons. Phosphorylated p38 level in hypothalamus is significantly enhanced in Shank3(-/-) mice. Consistently, overexpression of p38? in ARC or AgRP neurons elicits excessive stereotypic behavior and impairs sociability in wild-type (WT) mice. Notably, activated p38? in AgRP neurons increases stereotypic behavior and impairs sociability. Conversely, inactivated p38? in AgRP neurons significantly ameliorates autistic behaviors of Shank3(-/-) mice. In contrast, activated p38? in pro-opiomelanocortin (POMC) neurons does not affect stereotypic behavior and sociability in mice. LIMITATIONS: We demonstrated that SHANK3 regulates the phosphorylated p38 level in the hypothalamus and inactivated p38? in AgRP neurons significantly ameliorates autistic behaviors of Shank3(-/-) mice. However, we did not clarify the biochemical mechanism of SHANK3 inhibiting p38? in AgRP neurons. CONCLUSIONS: These results demonstrate that the Shank3 deficiency caused autistic-like behaviors by activating p38? signaling in AgRP neurons, suggesting that p38? signaling in AgRP neurons is a potential therapeutic target for Shank3 mutant-related autism. En ligne : https://dx.doi.org/10.1186/s13229-024-00595-4 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=538

Analysis of neuroanatomical differences in mice with genetically modified serotonin transporters assessed by structural magnetic resonance imaging / J. ELLEGOOD in Molecular Autism, 9 (2018)  

Public ISBD [article]  inMolecular Autism > 9 (2018) . - 24p. Titre : Analysis of neuroanatomical differences in mice with genetically modified serotonin transporters assessed by structural magnetic resonance imaging Type de document : Texte imprimé et/ou numérique Auteurs : J. ELLEGOOD, Auteur ; Y. YEE, Auteur ; T. M. KERR, Auteur ; C. L. MULLER, Auteur ; R. D. BLAKELY, Auteur ; R. M. HENKELMAN, Auteur ; J. VEENSTRA-VANDERWEELE, Auteur ; J. P. LERCH, Auteur Article en page(s) : 24p. Langues : Anglais (eng) Mots-clés : Animals  Brain/diagnostic imaging/metabolism  Female  Magnetic Resonance Imaging  Male  Mice  Mice, Inbred C57BL  Mutation  Neurons/metabolism  Serotonin/metabolism  Serotonin Plasma Membrane Transport Proteins/genetics/metabolism  5-ht  5htt  Brain  Dorsal raphe  Magnetic resonance imaging  Neurodevelopment  Serotonin  Slc6a4 Index. décimale : PER Périodiques Résumé : Background: The serotonin (5-HT) system has long been implicated in autism spectrum disorder (ASD) as indicated by elevated whole blood and platelet 5-HT, altered platelet and brain receptor and transporter binding, and genetic linkage and association findings. Based upon work in genetically modified mice, 5-HT is known to influence several aspects of brain development, but systematic neuroimaging studies have not previously been reported. In particular, the 5-HT transporter (serotonin transporter, SERT; 5-HTT) gene, Slc6a4, has been extensively studied. Methods: Using a 7-T MRI and deformation-based morphometry, we assessed neuroanatomical differences in an Slc6a4 knockout mouse on a C57BL/6 genetic background, along with an Slc6a4 Ala56 knockin mouse on two different genetic backgrounds (129S and C57BL/6). Results: Individually (same sex, same background, same genotype), the only differences found were in the female Slc6a4 knockout mouse; all the others had no significant differences. However, an analysis of variance across the whole study sample revealed a significant effect of Slc6a4 on the amygdala, thalamus, dorsal raphe nucleus, and lateral and frontal cortices. Conclusions: This work shows that an increase or decrease in SERT function has a significant effect on the neuroanatomy in 5-HT relevant regions, particularly the raphe nuclei. Notably, the Slc6a4 Ala56 knockin alone appears to have an insignificant, but suggestive, effect compared to the KO, which is consistent with Slc6a4 function. Despite the small number of 5-HT neurons and their localization to the brainstem, it is clear that 5-HT plays an important role in neuroanatomical organization. En ligne : https://dx.doi.org/10.1186/s13229-018-0210-z Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=371 [article] Analysis of neuroanatomical differences in mice with genetically modified serotonin transporters assessed by structural magnetic resonance imaging [Texte imprimé et/ou numérique] / J. ELLEGOOD, Auteur ; Y. YEE, Auteur ; T. M. KERR, Auteur ; C. L. MULLER, Auteur ; R. D. BLAKELY, Auteur ; R. M. HENKELMAN, Auteur ; J. VEENSTRA-VANDERWEELE, Auteur ; J. P. LERCH, Auteur . - 24p. Langues : Anglais (eng) in Molecular Autism > 9 (2018) . - 24p. Mots-clés : Animals  Brain/diagnostic imaging/metabolism  Female  Magnetic Resonance Imaging  Male  Mice  Mice, Inbred C57BL  Mutation  Neurons/metabolism  Serotonin/metabolism  Serotonin Plasma Membrane Transport Proteins/genetics/metabolism  5-ht  5htt  Brain  Dorsal raphe  Magnetic resonance imaging  Neurodevelopment  Serotonin  Slc6a4 Index. décimale : PER Périodiques Résumé : Background: The serotonin (5-HT) system has long been implicated in autism spectrum disorder (ASD) as indicated by elevated whole blood and platelet 5-HT, altered platelet and brain receptor and transporter binding, and genetic linkage and association findings. Based upon work in genetically modified mice, 5-HT is known to influence several aspects of brain development, but systematic neuroimaging studies have not previously been reported. In particular, the 5-HT transporter (serotonin transporter, SERT; 5-HTT) gene, Slc6a4, has been extensively studied. Methods: Using a 7-T MRI and deformation-based morphometry, we assessed neuroanatomical differences in an Slc6a4 knockout mouse on a C57BL/6 genetic background, along with an Slc6a4 Ala56 knockin mouse on two different genetic backgrounds (129S and C57BL/6). Results: Individually (same sex, same background, same genotype), the only differences found were in the female Slc6a4 knockout mouse; all the others had no significant differences. However, an analysis of variance across the whole study sample revealed a significant effect of Slc6a4 on the amygdala, thalamus, dorsal raphe nucleus, and lateral and frontal cortices. Conclusions: This work shows that an increase or decrease in SERT function has a significant effect on the neuroanatomy in 5-HT relevant regions, particularly the raphe nuclei. Notably, the Slc6a4 Ala56 knockin alone appears to have an insignificant, but suggestive, effect compared to the KO, which is consistent with Slc6a4 function. Despite the small number of 5-HT neurons and their localization to the brainstem, it is clear that 5-HT plays an important role in neuroanatomical organization. En ligne : https://dx.doi.org/10.1186/s13229-018-0210-z Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=371

Convergent depression of activity-dependent bulk endocytosis in rodent models of autism spectrum disorder / Mohammed Sarfaraz NAWAZ ; Peter C KIND ; Michael A COUSIN in Molecular Autism, 16 (2025)  

Public ISBD [article]  inMolecular Autism > 16 (2025) . - 26 Titre : Convergent depression of activity-dependent bulk endocytosis in rodent models of autism spectrum disorder Type de document : Texte imprimé et/ou numérique Auteurs : Mohammed Sarfaraz NAWAZ, Auteur ; Peter C KIND, Auteur ; Michael A COUSIN, Auteur Article en page(s) : 26 Langues : Anglais (eng) Mots-clés : Animals  Endocytosis  Disease Models, Animal  Rats  Synaptic Vesicles/metabolism  Autism Spectrum Disorder/metabolism/physiopathology/genetics/pathology  Neurons/metabolism  Cells, Cultured  Exocytosis  Activity  Autism  Endocytosis  Hippocampus  Presynapse  Rat  Vesicle  performed in accordance with the UK Animal (Scientific Procedures) Act 1986,  under Project and Personal Licence authority and were approved by the Animal  Welfare and Ethical Review Body at the University of Edinburgh (Home Office  project licence - 7008878). Similarly, procedures were conducted in accordance  with protocols approved by the Institutional Animal Ethics Committee of Institute  for Stem Cell Science and Regenerative Medicine, Bangalore. Consent for  publication: Not applicable. Competing interests: Peter Kind is an Associate  Editor for Molecular Autism. Index. décimale : PER Périodiques Résumé : BACKGROUND: The key pathological mechanisms underlying autism spectrum disorder (ASD) remain relatively undetermined, potentially due to the heterogenous nature of the condition. Targeted studies of a series of monogenic ASDs have revealed postsynaptic dysfunction as a central conserved mechanism. Presynaptic dysfunction is emerging as an additional disease locus in neurodevelopmental disorders; however, it is unclear whether this dysfunction drives ASD or is an adaptation to the altered brain microenvironment. METHODS: To differentiate between these two competing scenarios, we performed a high content analysis of key stages of the synaptic vesicle lifecycle in primary neuronal cultures derived from a series of preclinical rat models of monogenic ASD. These five independent models (Nrxn1(+/-), Nlgn3(-/y), Syngap(+/-), Syngap(+/?-GAP), Pten(+/-)) were specifically selected to have perturbations in a diverse palette of genes that were expressed either at the pre- or post-synapse. Synaptic vesicle exocytosis and cargo trafficking were triggered via two discrete trains of activity and monitored using the genetically-encoded reporter synaptophysin-pHluorin. Activity-dependent bulk endocytosis was assessed during intense neuronal activity using the fluid phase marker tetramethylrhodamine-dextran. RESULTS: Both synaptic vesicle fusion events and cargo trafficking were unaffected in all models investigated under all stimulation protocols. However, a key convergent phenotype across neurons derived from all five models was revealed, a depression in activity-dependent bulk endocytosis. LIMITATIONS: The study is exclusively conducted in primary cultures of hippocampal neurons; therefore, the impact on neurons from other brain regions or altered brain microcircuitry was not assessed. No molecular mechanism has been identified for this depression. CONCLUSION: This suggests that depression of activity-dependent bulk endocytosis is a presynaptic homeostatic mechanism to correct for intrinsic dysfunction in ASD neurons. En ligne : https://dx.doi.org/10.1186/s13229-025-00660-6 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=555 [article] Convergent depression of activity-dependent bulk endocytosis in rodent models of autism spectrum disorder [Texte imprimé et/ou numérique] / Mohammed Sarfaraz NAWAZ, Auteur ; Peter C KIND, Auteur ; Michael A COUSIN, Auteur . - 26. Langues : Anglais (eng) in Molecular Autism > 16 (2025) . - 26 Mots-clés : Animals  Endocytosis  Disease Models, Animal  Rats  Synaptic Vesicles/metabolism  Autism Spectrum Disorder/metabolism/physiopathology/genetics/pathology  Neurons/metabolism  Cells, Cultured  Exocytosis  Activity  Autism  Endocytosis  Hippocampus  Presynapse  Rat  Vesicle  performed in accordance with the UK Animal (Scientific Procedures) Act 1986,  under Project and Personal Licence authority and were approved by the Animal  Welfare and Ethical Review Body at the University of Edinburgh (Home Office  project licence - 7008878). Similarly, procedures were conducted in accordance  with protocols approved by the Institutional Animal Ethics Committee of Institute  for Stem Cell Science and Regenerative Medicine, Bangalore. Consent for  publication: Not applicable. Competing interests: Peter Kind is an Associate  Editor for Molecular Autism. Index. décimale : PER Périodiques Résumé : BACKGROUND: The key pathological mechanisms underlying autism spectrum disorder (ASD) remain relatively undetermined, potentially due to the heterogenous nature of the condition. Targeted studies of a series of monogenic ASDs have revealed postsynaptic dysfunction as a central conserved mechanism. Presynaptic dysfunction is emerging as an additional disease locus in neurodevelopmental disorders; however, it is unclear whether this dysfunction drives ASD or is an adaptation to the altered brain microenvironment. METHODS: To differentiate between these two competing scenarios, we performed a high content analysis of key stages of the synaptic vesicle lifecycle in primary neuronal cultures derived from a series of preclinical rat models of monogenic ASD. These five independent models (Nrxn1(+/-), Nlgn3(-/y), Syngap(+/-), Syngap(+/?-GAP), Pten(+/-)) were specifically selected to have perturbations in a diverse palette of genes that were expressed either at the pre- or post-synapse. Synaptic vesicle exocytosis and cargo trafficking were triggered via two discrete trains of activity and monitored using the genetically-encoded reporter synaptophysin-pHluorin. Activity-dependent bulk endocytosis was assessed during intense neuronal activity using the fluid phase marker tetramethylrhodamine-dextran. RESULTS: Both synaptic vesicle fusion events and cargo trafficking were unaffected in all models investigated under all stimulation protocols. However, a key convergent phenotype across neurons derived from all five models was revealed, a depression in activity-dependent bulk endocytosis. LIMITATIONS: The study is exclusively conducted in primary cultures of hippocampal neurons; therefore, the impact on neurons from other brain regions or altered brain microcircuitry was not assessed. No molecular mechanism has been identified for this depression. CONCLUSION: This suggests that depression of activity-dependent bulk endocytosis is a presynaptic homeostatic mechanism to correct for intrinsic dysfunction in ASD neurons. En ligne : https://dx.doi.org/10.1186/s13229-025-00660-6 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=555

Detection of autism spectrum disorder-related pathogenic trio variants by a novel structure-based approach / Sadhna RAO in Molecular Autism, 15 (2024)  

Public ISBD [article]  inMolecular Autism > 15 (2024) . - 12p. Titre : Detection of autism spectrum disorder-related pathogenic trio variants by a novel structure-based approach Type de document : Texte imprimé et/ou numérique Auteurs : Sadhna RAO, Auteur ; Anastasiia SADYBEKOV, Auteur ; David C. DEWITT, Auteur ; Joanna LIPKA, Auteur ; Vsevolod KATRITCH, Auteur ; Bruce E. HERRING, Auteur Article en page(s) : 12p. Langues : Anglais (eng) Mots-clés : Humans  Autism Spectrum Disorder/genetics/metabolism  HEK293 Cells  Intellectual Disability/genetics/metabolism  Mutation  Mutation, Missense  Neurons/metabolism  Autism spectrum disorders  Glutamatergic neurotransmission  Missense mutations  Mutation modeling  Synaptic dysfunction  TRIO-related disorders Index. décimale : PER Périodiques Résumé : BACKGROUND: Glutamatergic synapse dysfunction is believed to underlie the development of Autism Spectrum Disorder (ASD) and Intellectual Disability (ID) in many individuals. However, identification of genetic markers that contribute to synaptic dysfunction in these individuals is notoriously difficult. Based on genomic analysis, structural modeling, and functional data, we recently established the involvement of the TRIO-RAC1 pathway in ASD and ID. Furthermore, we identified a pathological de novo missense mutation hotspot in TRIO's GEF1 domain. ASD/ID-related missense mutations within this domain compromise glutamatergic synapse function and likely contribute to the development of ASD/ID. The number of ASD/ID cases with mutations identified within TRIO's GEF1 domain is increasing. However, tools for accurately predicting whether such mutations are detrimental to protein function are lacking. METHODS: Here we deployed advanced protein structural modeling techniques to predict potential de novo pathogenic and benign mutations within TRIO's GEF1 domain. Mutant TRIO-9 constructs were generated and expressed in CA1 pyramidal neurons of organotypic cultured hippocampal slices. AMPA receptor-mediated postsynaptic currents were examined in these neurons using dual whole-cell patch clamp electrophysiology. We also validated these findings using orthogonal co-immunoprecipitation and fluorescence lifetime imaging (FLIM-FRET) experiments to assay TRIO mutant overexpression effects on TRIO-RAC1 binding and on RAC1 activity in HEK293/T cells. RESULTS: Missense mutations in TRIO's GEF1 domain that were predicted to disrupt TRIO-RAC1 binding or stability were tested experimentally and found to greatly impair TRIO-9's influence on glutamatergic synapse function. In contrast, missense mutations in TRIO's GEF1 domain that were predicted to have minimal effect on TRIO-RAC1 binding or stability did not impair TRIO-9's influence on glutamatergic synapse function in our experimental assays. In orthogonal assays, we find most of the mutations predicted to disrupt binding display loss of function but mutants predicted to disrupt stability do not reflect our results from neuronal electrophysiological data. LIMITATIONS: We present a method to predict missense mutations in TRIO's GEF1 domain that may compromise TRIO function and test for effects in a limited number of assays. Possible limitations arising from the model systems employed here can be addressed in future studies. Our method does not provide evidence for whether these mutations confer ASD/ID risk or the likelihood that such mutations will result in the development of ASD/ID. CONCLUSIONS: Here we show that a combination of structure-based computational predictions and experimental validation can be employed to reliably predict whether missense mutations in the human TRIO gene impede TRIO protein function and compromise TRIO's role in glutamatergic synapse regulation. With the growing accessibility of genome sequencing, the use of such tools in the accurate identification of pathological mutations will be instrumental in diagnostics of ASD/ID. En ligne : https://dx.doi.org/10.1186/s13229-024-00590-9 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=538 [article] Detection of autism spectrum disorder-related pathogenic trio variants by a novel structure-based approach [Texte imprimé et/ou numérique] / Sadhna RAO, Auteur ; Anastasiia SADYBEKOV, Auteur ; David C. DEWITT, Auteur ; Joanna LIPKA, Auteur ; Vsevolod KATRITCH, Auteur ; Bruce E. HERRING, Auteur . - 12p. Langues : Anglais (eng) in Molecular Autism > 15 (2024) . - 12p. Mots-clés : Humans  Autism Spectrum Disorder/genetics/metabolism  HEK293 Cells  Intellectual Disability/genetics/metabolism  Mutation  Mutation, Missense  Neurons/metabolism  Autism spectrum disorders  Glutamatergic neurotransmission  Missense mutations  Mutation modeling  Synaptic dysfunction  TRIO-related disorders Index. décimale : PER Périodiques Résumé : BACKGROUND: Glutamatergic synapse dysfunction is believed to underlie the development of Autism Spectrum Disorder (ASD) and Intellectual Disability (ID) in many individuals. However, identification of genetic markers that contribute to synaptic dysfunction in these individuals is notoriously difficult. Based on genomic analysis, structural modeling, and functional data, we recently established the involvement of the TRIO-RAC1 pathway in ASD and ID. Furthermore, we identified a pathological de novo missense mutation hotspot in TRIO's GEF1 domain. ASD/ID-related missense mutations within this domain compromise glutamatergic synapse function and likely contribute to the development of ASD/ID. The number of ASD/ID cases with mutations identified within TRIO's GEF1 domain is increasing. However, tools for accurately predicting whether such mutations are detrimental to protein function are lacking. METHODS: Here we deployed advanced protein structural modeling techniques to predict potential de novo pathogenic and benign mutations within TRIO's GEF1 domain. Mutant TRIO-9 constructs were generated and expressed in CA1 pyramidal neurons of organotypic cultured hippocampal slices. AMPA receptor-mediated postsynaptic currents were examined in these neurons using dual whole-cell patch clamp electrophysiology. We also validated these findings using orthogonal co-immunoprecipitation and fluorescence lifetime imaging (FLIM-FRET) experiments to assay TRIO mutant overexpression effects on TRIO-RAC1 binding and on RAC1 activity in HEK293/T cells. RESULTS: Missense mutations in TRIO's GEF1 domain that were predicted to disrupt TRIO-RAC1 binding or stability were tested experimentally and found to greatly impair TRIO-9's influence on glutamatergic synapse function. In contrast, missense mutations in TRIO's GEF1 domain that were predicted to have minimal effect on TRIO-RAC1 binding or stability did not impair TRIO-9's influence on glutamatergic synapse function in our experimental assays. In orthogonal assays, we find most of the mutations predicted to disrupt binding display loss of function but mutants predicted to disrupt stability do not reflect our results from neuronal electrophysiological data. LIMITATIONS: We present a method to predict missense mutations in TRIO's GEF1 domain that may compromise TRIO function and test for effects in a limited number of assays. Possible limitations arising from the model systems employed here can be addressed in future studies. Our method does not provide evidence for whether these mutations confer ASD/ID risk or the likelihood that such mutations will result in the development of ASD/ID. CONCLUSIONS: Here we show that a combination of structure-based computational predictions and experimental validation can be employed to reliably predict whether missense mutations in the human TRIO gene impede TRIO protein function and compromise TRIO's role in glutamatergic synapse regulation. With the growing accessibility of genome sequencing, the use of such tools in the accurate identification of pathological mutations will be instrumental in diagnostics of ASD/ID. En ligne : https://dx.doi.org/10.1186/s13229-024-00590-9 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=538

Identifying SETBP1 haploinsufficiency molecular pathways to improve patient diagnosis using induced pluripotent stem cells and neural disease modelling / Nicole C. SHAW in Molecular Autism, 15 (2024)  

Public ISBD [article]  inMolecular Autism > 15 (2024) . - 42p. Titre : Identifying SETBP1 haploinsufficiency molecular pathways to improve patient diagnosis using induced pluripotent stem cells and neural disease modelling Type de document : Texte imprimé et/ou numérique Auteurs : Nicole C. SHAW, Auteur ; Kevin CHEN, Auteur ; Kathryn O. FARLEY, Auteur ; Mitchell HEDGES, Auteur ; Catherine FORBES, Auteur ; Gareth BAYNAM, Auteur ; Timo LASSMANN, Auteur ; Vanessa S. FEAR, Auteur Article en page(s) : 42p. Langues : Anglais (eng) Mots-clés : Induced Pluripotent Stem Cells/metabolism/cytology  Humans  Haploinsufficiency  Cell Differentiation  Carrier Proteins/genetics  Nuclear Proteins/genetics/metabolism  Mutation  GATA2 Transcription Factor/genetics/metabolism  Neurons/metabolism  Neural Stem Cells/metabolism  Wnt Signaling Pathway/genetics  Intellectual Disability/genetics  Phenotype  Crispr  Neural cell modelling  Neurodevelopmental disorders  SETBP1 haploinsufficiency disorder  Variants of unknown significance  iPSC Index. décimale : PER Périodiques Résumé : BACKGROUND: SETBP1 Haploinsufficiency Disorder (SETBP1-HD) is characterised by mild to moderate intellectual disability, speech and language impairment, mild motor developmental delay, behavioural issues, hypotonia, mild facial dysmorphisms, and vision impairment. Despite a clear link between SETBP1 mutations and neurodevelopmental disorders the precise role of SETBP1 in neural development remains elusive. We investigate the functional effects of three SETBP1 genetic variants including two pathogenic mutations p.Glu545Ter and SETBP1 p.Tyr1066Ter, resulting in removal of SKI and/or SET domains, and a point mutation p.Thr1387Met in the SET domain. METHODS: Genetic variants were introduced into induced pluripotent stem cells (iPSCs) and subsequently differentiated into neurons to model the disease. We measured changes in cellular differentiation, SETBP1 protein localisation, and gene expression changes. RESULTS: The data indicated a change in the WNT pathway, RNA polymerase II pathway and identified GATA2 as a central transcription factor in disease perturbation. In addition, the genetic variants altered the expression of gene sets related to neural forebrain development matching characteristics typical of the SETBP1-HD phenotype. LIMITATIONS: The study investigates changes in cellular function in differentiation of iPSC to neural progenitor cells as a human model of SETBP1 HD disorder. Future studies may provide additional information relevant to disease on further neural cell specification, to derive mature neurons, neural forebrain cells, or brain organoids. CONCLUSIONS: We developed a human SETBP1-HD model and identified perturbations to the WNT and POL2RA pathway, genes regulated by GATA2. Strikingly neural cells for both the SETBP1 truncation mutations and the single nucleotide variant displayed a SETBP1-HD-like phenotype. En ligne : https://dx.doi.org/10.1186/s13229-024-00625-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=538 [article] Identifying SETBP1 haploinsufficiency molecular pathways to improve patient diagnosis using induced pluripotent stem cells and neural disease modelling [Texte imprimé et/ou numérique] / Nicole C. SHAW, Auteur ; Kevin CHEN, Auteur ; Kathryn O. FARLEY, Auteur ; Mitchell HEDGES, Auteur ; Catherine FORBES, Auteur ; Gareth BAYNAM, Auteur ; Timo LASSMANN, Auteur ; Vanessa S. FEAR, Auteur . - 42p. Langues : Anglais (eng) in Molecular Autism > 15 (2024) . - 42p. Mots-clés : Induced Pluripotent Stem Cells/metabolism/cytology  Humans  Haploinsufficiency  Cell Differentiation  Carrier Proteins/genetics  Nuclear Proteins/genetics/metabolism  Mutation  GATA2 Transcription Factor/genetics/metabolism  Neurons/metabolism  Neural Stem Cells/metabolism  Wnt Signaling Pathway/genetics  Intellectual Disability/genetics  Phenotype  Crispr  Neural cell modelling  Neurodevelopmental disorders  SETBP1 haploinsufficiency disorder  Variants of unknown significance  iPSC Index. décimale : PER Périodiques Résumé : BACKGROUND: SETBP1 Haploinsufficiency Disorder (SETBP1-HD) is characterised by mild to moderate intellectual disability, speech and language impairment, mild motor developmental delay, behavioural issues, hypotonia, mild facial dysmorphisms, and vision impairment. Despite a clear link between SETBP1 mutations and neurodevelopmental disorders the precise role of SETBP1 in neural development remains elusive. We investigate the functional effects of three SETBP1 genetic variants including two pathogenic mutations p.Glu545Ter and SETBP1 p.Tyr1066Ter, resulting in removal of SKI and/or SET domains, and a point mutation p.Thr1387Met in the SET domain. METHODS: Genetic variants were introduced into induced pluripotent stem cells (iPSCs) and subsequently differentiated into neurons to model the disease. We measured changes in cellular differentiation, SETBP1 protein localisation, and gene expression changes. RESULTS: The data indicated a change in the WNT pathway, RNA polymerase II pathway and identified GATA2 as a central transcription factor in disease perturbation. In addition, the genetic variants altered the expression of gene sets related to neural forebrain development matching characteristics typical of the SETBP1-HD phenotype. LIMITATIONS: The study investigates changes in cellular function in differentiation of iPSC to neural progenitor cells as a human model of SETBP1 HD disorder. Future studies may provide additional information relevant to disease on further neural cell specification, to derive mature neurons, neural forebrain cells, or brain organoids. CONCLUSIONS: We developed a human SETBP1-HD model and identified perturbations to the WNT and POL2RA pathway, genes regulated by GATA2. Strikingly neural cells for both the SETBP1 truncation mutations and the single nucleotide variant displayed a SETBP1-HD-like phenotype. En ligne : https://dx.doi.org/10.1186/s13229-024-00625-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=538

Behavioral decline in Shank3(?ex4-22) mice during early adulthood parallels cerebellar granule cell glutamatergic synaptic changes / James O BEAVERS ; Romana HYDE ; Roseline EWA ; Amber SCHWERTMAN ; Sarahi PORCAYO ; Ben D RICHARDSON in Molecular Autism, 15 (2024)  

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