Lack of association of rare functional variants in TSC1/TSC2 genes with autism spectrum disorder / Samira BAHL in Molecular Autism, (March 2013)  

Public ISBD [article]  inMolecular Autism > (March 2013) . - 11 p. Titre : Lack of association of rare functional variants in TSC1/TSC2 genes with autism spectrum disorder Type de document : Texte imprimé et/ou numérique Auteurs : Samira BAHL, Auteur ; Colby CHIANG, Auteur ; Roberta L. BEAUCHAMP, Auteur ; Benjamin NEALE, Auteur ; Mark J. DALY, Auteur ; James GUSELLA, Auteur ; Michael E. TALKOWSKI, Auteur ; Vijaya RAMESH, Auteur Année de publication : 2013 Article en page(s) : 11 p. Langues : Anglais (eng) Mots-clés : Autism spectrum disorder  Tuberous sclerosis complex  Mammalian target of rapamycin  Next-generation sequencing  Rare variants Index. décimale : PER Périodiques Résumé : BACKGROUND:Autism spectrum disorder (ASD) is reported in 30 to 60% of patients with tuberous sclerosis complex (TSC) but shared genetic mechanisms that exist between TSC-associated ASD and idiopathic ASD have yet to be determined. Through the small G-protein Rheb, the TSC proteins, hamartin and tuberin, negatively regulate mammalian target of rapamycin complex 1 (mTORC1) signaling. It is well established that mTORC1 plays a pivotal role in neuronal translation and connectivity, so dysregulation of mTORC1 signaling could be a common feature in many ASDs. Pam, an E3 ubiquitin ligase, binds to TSC proteins and regulates mTORC1 signaling in the CNS, and the FBXO45-Pam ubiquitin ligase complex plays an essential role in neurodevelopment by regulating synapse formation and growth. Since mounting evidence has established autism as a disorder of the synapses, we tested whether rare genetic variants in TSC1, TSC2, MYCBP2, RHEB and FBXO45, genes that regulate mTORC1 signaling and/or play a role in synapse development and function, contribute to the pathogenesis of idiopathic ASD.METHODS:Exons and splice junctions of TSC1, TSC2, MYCBP2, RHEB and FBXO45 were resequenced for 300 ASD trios from the Simons Simplex Collection (SSC) using a pooled PCR amplification and next-generation sequencing strategy, targeted to the discovery of deleterious coding variation. These detected, potentially functional, variants were confirmed by Sanger sequencing of the individual samples comprising the pools in which they were identified.RESULTS:We identified a total of 23 missense variants in MYCBP2, TSC1 and TSC2. These variants exhibited a near equal distribution between the proband and parental pools, with no statistical excess in ASD cases (P 0.05). All proband variants were inherited. No putative deleterious variants were confirmed in RHEB and FBXO45. Three intronic variants, identified as potential splice defects in MYCBP2 did not show aberrant splicing upon RNA assay. Overall, we did not find an over-representation of ASD causal variants in the genes studied to support them as contributors to autism susceptibility.CONCLUSIONS:We did not observe an enrichment of rare functional variants in TSC1 and TSC2 genes in our sample set of 300 trios. En ligne : http://dx.doi.org/10.1186/2040-2392-4-5 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=202 [article] Lack of association of rare functional variants in TSC1/TSC2 genes with autism spectrum disorder [Texte imprimé et/ou numérique] / Samira BAHL, Auteur ; Colby CHIANG, Auteur ; Roberta L. BEAUCHAMP, Auteur ; Benjamin NEALE, Auteur ; Mark J. DALY, Auteur ; James GUSELLA, Auteur ; Michael E. TALKOWSKI, Auteur ; Vijaya RAMESH, Auteur . - 2013 . - 11 p. Langues : Anglais (eng) in Molecular Autism > (March 2013) . - 11 p. Mots-clés : Autism spectrum disorder  Tuberous sclerosis complex  Mammalian target of rapamycin  Next-generation sequencing  Rare variants Index. décimale : PER Périodiques Résumé : BACKGROUND:Autism spectrum disorder (ASD) is reported in 30 to 60% of patients with tuberous sclerosis complex (TSC) but shared genetic mechanisms that exist between TSC-associated ASD and idiopathic ASD have yet to be determined. Through the small G-protein Rheb, the TSC proteins, hamartin and tuberin, negatively regulate mammalian target of rapamycin complex 1 (mTORC1) signaling. It is well established that mTORC1 plays a pivotal role in neuronal translation and connectivity, so dysregulation of mTORC1 signaling could be a common feature in many ASDs. Pam, an E3 ubiquitin ligase, binds to TSC proteins and regulates mTORC1 signaling in the CNS, and the FBXO45-Pam ubiquitin ligase complex plays an essential role in neurodevelopment by regulating synapse formation and growth. Since mounting evidence has established autism as a disorder of the synapses, we tested whether rare genetic variants in TSC1, TSC2, MYCBP2, RHEB and FBXO45, genes that regulate mTORC1 signaling and/or play a role in synapse development and function, contribute to the pathogenesis of idiopathic ASD.METHODS:Exons and splice junctions of TSC1, TSC2, MYCBP2, RHEB and FBXO45 were resequenced for 300 ASD trios from the Simons Simplex Collection (SSC) using a pooled PCR amplification and next-generation sequencing strategy, targeted to the discovery of deleterious coding variation. These detected, potentially functional, variants were confirmed by Sanger sequencing of the individual samples comprising the pools in which they were identified.RESULTS:We identified a total of 23 missense variants in MYCBP2, TSC1 and TSC2. These variants exhibited a near equal distribution between the proband and parental pools, with no statistical excess in ASD cases (P 0.05). All proband variants were inherited. No putative deleterious variants were confirmed in RHEB and FBXO45. Three intronic variants, identified as potential splice defects in MYCBP2 did not show aberrant splicing upon RNA assay. Overall, we did not find an over-representation of ASD causal variants in the genes studied to support them as contributors to autism susceptibility.CONCLUSIONS:We did not observe an enrichment of rare functional variants in TSC1 and TSC2 genes in our sample set of 300 trios. En ligne : http://dx.doi.org/10.1186/2040-2392-4-5 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=202

Prevalence and phenotypic impact of rare potentially damaging variants in autism spectrum disorder / B. MAHJANI in Molecular Autism, 12 (2021)  

Public ISBD [article]  inMolecular Autism > 12 (2021) . - 65 p. Titre : Prevalence and phenotypic impact of rare potentially damaging variants in autism spectrum disorder Type de document : Texte imprimé et/ou numérique Auteurs : B. MAHJANI, Auteur ; S. DE RUBEIS, Auteur ; C. GUSTAVSSON MAHJANI, Auteur ; M. MULHERN, Auteur ; X. XU, Auteur ; L. KLEI, Auteur ; F. K. SATTERSTROM, Auteur ; J. FU, Auteur ; Michael E. TALKOWSKI, Auteur ; A. REICHENBERG, Auteur ; S. SANDIN, Auteur ; C. M. HULTMAN, Auteur ; D. E. GRICE, Auteur ; K. ROEDER, Auteur ; B. DEVLIN, Auteur ; Joseph D. BUXBAUM, Auteur Article en page(s) : 65 p. Langues : Anglais (eng) Mots-clés : Autism spectrum disorder  Copy number variant  Intellectual disability  Pages  Single nucleotide variant  Whole exome sequencing  that they have no competing interests. Index. décimale : PER Périodiques Résumé : BACKGROUND: The Autism Sequencing Consortium identified 102 high-confidence autism spectrum disorder (ASD) genes, showing that individuals with ASD and with potentially damaging single nucleotide variation (pdSNV) in these genes had lower cognitive levels and delayed age at walking, when compared to ASD participants without pdSNV. Here, we made use of a Swedish sample of individuals with ASD (called PAGES, for Population-Based Autism Genetics & Environment Study) to evaluate the frequency of pdSNV and their impact on medical and psychiatric phenotypes, using an epidemiological frame and universal health reporting. We then combine findings with those for potentially damaging copy number variation (pdCNV). METHODS: SNV and CNV calls were generated from whole-exome sequencing and chromosome microarray data, respectively. Birth and medical register data were used to collect phenotypes. RESULTS: Of 808 individuals assessed by sequencing, 69 (9%) had pdSNV in the 102 ASC genes, and 144 (18%) had pdSNV in the 102 ASC genes or in a larger set of curated neurodevelopmental genes (from the Deciphering Developmental Disorders study, the gene2phenotype database, and the Radboud University gene lists). Three or more individuals had pdSNV in GRIN2B, POGZ, SATB1, DYNC1H1, SCN8A, or CREBBP. In comparison, out of the 996 individuals from whom CNV were called, 105 (11%) carried one or more pdCNV, including four or more individuals with CNV in the recurrent 15q11q13, 22q11.2, and 16p11.2 loci. Carriers of pdSNV were more likely to have intellectual disability (ID) and epilepsy, while carriers of pdCNV showed increased rates of congenital anomalies and scholastic skill disorders. Carriers of either pdSNV or pdCNV were more likely to have ID, scholastic skill disorders, and epilepsy. LIMITATIONS: The cohort only included individuals with autistic disorder, the more severe form of ASD, and phenotypes are defined from medical registers. Not all genes studied are definitively ASD genes, and we did not have de novo information to aid in classification. CONCLUSIONS: In this epidemiological sample, rare pdSNV were more common than pdCNV and the combined yield of potentially damaging variation was substantial at 27%. The results provide compelling rationale for the use of high-throughout sequencing as part of routine clinical workup for ASD and support the development of precision medicine in ASD. En ligne : http://dx.doi.org/10.1186/s13229-021-00465-3 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=459 [article] Prevalence and phenotypic impact of rare potentially damaging variants in autism spectrum disorder [Texte imprimé et/ou numérique] / B. MAHJANI, Auteur ; S. DE RUBEIS, Auteur ; C. GUSTAVSSON MAHJANI, Auteur ; M. MULHERN, Auteur ; X. XU, Auteur ; L. KLEI, Auteur ; F. K. SATTERSTROM, Auteur ; J. FU, Auteur ; Michael E. TALKOWSKI, Auteur ; A. REICHENBERG, Auteur ; S. SANDIN, Auteur ; C. M. HULTMAN, Auteur ; D. E. GRICE, Auteur ; K. ROEDER, Auteur ; B. DEVLIN, Auteur ; Joseph D. BUXBAUM, Auteur . - 65 p. Langues : Anglais (eng) in Molecular Autism > 12 (2021) . - 65 p. Mots-clés : Autism spectrum disorder  Copy number variant  Intellectual disability  Pages  Single nucleotide variant  Whole exome sequencing  that they have no competing interests. Index. décimale : PER Périodiques Résumé : BACKGROUND: The Autism Sequencing Consortium identified 102 high-confidence autism spectrum disorder (ASD) genes, showing that individuals with ASD and with potentially damaging single nucleotide variation (pdSNV) in these genes had lower cognitive levels and delayed age at walking, when compared to ASD participants without pdSNV. Here, we made use of a Swedish sample of individuals with ASD (called PAGES, for Population-Based Autism Genetics & Environment Study) to evaluate the frequency of pdSNV and their impact on medical and psychiatric phenotypes, using an epidemiological frame and universal health reporting. We then combine findings with those for potentially damaging copy number variation (pdCNV). METHODS: SNV and CNV calls were generated from whole-exome sequencing and chromosome microarray data, respectively. Birth and medical register data were used to collect phenotypes. RESULTS: Of 808 individuals assessed by sequencing, 69 (9%) had pdSNV in the 102 ASC genes, and 144 (18%) had pdSNV in the 102 ASC genes or in a larger set of curated neurodevelopmental genes (from the Deciphering Developmental Disorders study, the gene2phenotype database, and the Radboud University gene lists). Three or more individuals had pdSNV in GRIN2B, POGZ, SATB1, DYNC1H1, SCN8A, or CREBBP. In comparison, out of the 996 individuals from whom CNV were called, 105 (11%) carried one or more pdCNV, including four or more individuals with CNV in the recurrent 15q11q13, 22q11.2, and 16p11.2 loci. Carriers of pdSNV were more likely to have intellectual disability (ID) and epilepsy, while carriers of pdCNV showed increased rates of congenital anomalies and scholastic skill disorders. Carriers of either pdSNV or pdCNV were more likely to have ID, scholastic skill disorders, and epilepsy. LIMITATIONS: The cohort only included individuals with autistic disorder, the more severe form of ASD, and phenotypes are defined from medical registers. Not all genes studied are definitively ASD genes, and we did not have de novo information to aid in classification. CONCLUSIONS: In this epidemiological sample, rare pdSNV were more common than pdCNV and the combined yield of potentially damaging variation was substantial at 27%. The results provide compelling rationale for the use of high-throughout sequencing as part of routine clinical workup for ASD and support the development of precision medicine in ASD. En ligne : http://dx.doi.org/10.1186/s13229-021-00465-3 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=459

Transcriptional consequences of MBD5 disruption in mouse brain and CRISPR-derived neurons / Catarina M. SEABRA in Molecular Autism, 11 (2020)  

Public ISBD [article]  inMolecular Autism > 11 (2020) . - 45 p. Titre : Transcriptional consequences of MBD5 disruption in mouse brain and CRISPR-derived neurons Type de document : Texte imprimé et/ou numérique Auteurs : Catarina M. SEABRA, Auteur ; Tatsiana ANEICHYK, Auteur ; Serkan ERDIN, Auteur ; Derek J. C. TAI, Auteur ; Celine E. F. DE ESCH, Auteur ; Parisa RAZAZ, Auteur ; Yu AN, Auteur ; Poornima MANAVALAN, Auteur ; Ashok RAGAVENDRAN, Auteur ; Alexei STORTCHEVOI, Auteur ; Clemer ABAD, Auteur ; Juan I. YOUNG, Auteur ; Patricia MACIEL, Auteur ; Michael E. TALKOWSKI, Auteur ; James F. GUSELLA, Auteur Article en page(s) : 45 p. Langues : Anglais (eng) Mots-clés : Autism spectrum disorder  Crispr  Mbd5  Mouse  Ndd  Neurons  Transcriptomics Index. décimale : PER Périodiques Résumé : BACKGROUND: MBD5, encoding the methyl-CpG-binding domain 5 protein, has been proposed as a necessary and sufficient driver of the 2q23.1 microdeletion syndrome. De novo missense and protein-truncating variants from exome sequencing studies have directly implicated MBD5 in the etiology of autism spectrum disorder (ASD) and related neurodevelopmental disorders (NDDs). However, little is known concerning the specific function(s) of MBD5. METHODS: To gain insight into the complex interactions associated with alteration of MBD5 in individuals with ASD and related NDDs, we explored the transcriptional landscape of MBD5 haploinsufficiency across multiple mouse brain regions of a heterozygous hypomorphic Mbd5(+/GT) mouse model, and compared these results to CRISPR-mediated mutations of MBD5 in human iPSC-derived neuronal models. RESULTS: Gene expression analyses across three brain regions from Mbd5(+/GT) mice showed subtle transcriptional changes, with cortex displaying the most widespread changes following Mbd5 reduction, indicating context-dependent effects. Comparison with MBD5 reduction in human neuronal cells reinforced the context-dependence of gene expression changes due to MBD5 deficiency. Gene co-expression network analyses revealed gene clusters that were associated with reduced MBD5 expression and enriched for terms related to ciliary function. LIMITATIONS: These analyses included a limited number of mouse brain regions and neuronal models, and the effects of the gene knockdown are subtle. As such, these results will not reflect the full extent of MBD5 disruption across human brain regions during early neurodevelopment in ASD, or capture the diverse spectrum of cell-type-specific changes associated with MBD5 alterations. CONCLUSIONS: Our study points to modest and context-dependent transcriptional consequences of Mbd5 disruption in the brain. It also suggests a possible link between MBD5 and perturbations in ciliary function, which is an established pathogenic mechanism in developmental disorders and syndromes. En ligne : http://dx.doi.org/10.1186/s13229-020-00354-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=427 [article] Transcriptional consequences of MBD5 disruption in mouse brain and CRISPR-derived neurons [Texte imprimé et/ou numérique] / Catarina M. SEABRA, Auteur ; Tatsiana ANEICHYK, Auteur ; Serkan ERDIN, Auteur ; Derek J. C. TAI, Auteur ; Celine E. F. DE ESCH, Auteur ; Parisa RAZAZ, Auteur ; Yu AN, Auteur ; Poornima MANAVALAN, Auteur ; Ashok RAGAVENDRAN, Auteur ; Alexei STORTCHEVOI, Auteur ; Clemer ABAD, Auteur ; Juan I. YOUNG, Auteur ; Patricia MACIEL, Auteur ; Michael E. TALKOWSKI, Auteur ; James F. GUSELLA, Auteur . - 45 p. Langues : Anglais (eng) in Molecular Autism > 11 (2020) . - 45 p. Mots-clés : Autism spectrum disorder  Crispr  Mbd5  Mouse  Ndd  Neurons  Transcriptomics Index. décimale : PER Périodiques Résumé : BACKGROUND: MBD5, encoding the methyl-CpG-binding domain 5 protein, has been proposed as a necessary and sufficient driver of the 2q23.1 microdeletion syndrome. De novo missense and protein-truncating variants from exome sequencing studies have directly implicated MBD5 in the etiology of autism spectrum disorder (ASD) and related neurodevelopmental disorders (NDDs). However, little is known concerning the specific function(s) of MBD5. METHODS: To gain insight into the complex interactions associated with alteration of MBD5 in individuals with ASD and related NDDs, we explored the transcriptional landscape of MBD5 haploinsufficiency across multiple mouse brain regions of a heterozygous hypomorphic Mbd5(+/GT) mouse model, and compared these results to CRISPR-mediated mutations of MBD5 in human iPSC-derived neuronal models. RESULTS: Gene expression analyses across three brain regions from Mbd5(+/GT) mice showed subtle transcriptional changes, with cortex displaying the most widespread changes following Mbd5 reduction, indicating context-dependent effects. Comparison with MBD5 reduction in human neuronal cells reinforced the context-dependence of gene expression changes due to MBD5 deficiency. Gene co-expression network analyses revealed gene clusters that were associated with reduced MBD5 expression and enriched for terms related to ciliary function. LIMITATIONS: These analyses included a limited number of mouse brain regions and neuronal models, and the effects of the gene knockdown are subtle. As such, these results will not reflect the full extent of MBD5 disruption across human brain regions during early neurodevelopment in ASD, or capture the diverse spectrum of cell-type-specific changes associated with MBD5 alterations. CONCLUSIONS: Our study points to modest and context-dependent transcriptional consequences of Mbd5 disruption in the brain. It also suggests a possible link between MBD5 and perturbations in ciliary function, which is an established pathogenic mechanism in developmental disorders and syndromes. En ligne : http://dx.doi.org/10.1186/s13229-020-00354-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=427

TSC patient-derived isogenic neural progenitor cells reveal altered early neurodevelopmental phenotypes and rapamycin-induced MNK-eIF4E signaling / Pauline MARTIN in Molecular Autism, 11 (2020)  

Public ISBD [article]  inMolecular Autism > 11 (2020) . - 2 p. Titre : TSC patient-derived isogenic neural progenitor cells reveal altered early neurodevelopmental phenotypes and rapamycin-induced MNK-eIF4E signaling Type de document : Texte imprimé et/ou numérique Auteurs : Pauline MARTIN, Auteur ; Vilas WAGH, Auteur ; Surya A. REIS, Auteur ; Serkan ERDIN, Auteur ; Roberta L. BEAUCHAMP, Auteur ; Ghalib SHAIKH, Auteur ; Michael E. TALKOWSKI, Auteur ; Elizabeth THIELE, Auteur ; Steven D. SHERIDAN, Auteur ; Stephen J. HAGGARTY, Auteur ; Vijaya RAMESH, Auteur Article en page(s) : 2 p. Langues : Anglais (eng) Mots-clés : CRISPR/Cas9  Disease modeling  Early neurodevelopment  Induced pluripotent stem cells  mek-erk1/2  MNK1/2-eIF4E  Neural progenitor cells  tsc1  Tuberous sclerosis complex  mTORC1  Therapeutics, Psy Therapeutics, and Souvien Therapeutics, none of who were involved  in this study. SDS is a scientific advisor for Outermost Therapeutics, Inc., which  played no part in the present study. The other authors declare no competing  interests. Index. décimale : PER Périodiques Résumé : BACKGROUND: Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder with frequent occurrence of epilepsy, autism spectrum disorder (ASD), intellectual disability (ID), and tumors in multiple organs. The aberrant activation of mTORC1 in TSC has led to treatment with mTORC1 inhibitor rapamycin as a lifelong therapy for tumors, but TSC-associated neurocognitive manifestations remain unaffected by rapamycin. METHODS: Here, we generated patient-specific, induced pluripotent stem cells (iPSCs) from a TSC patient with a heterozygous, germline, nonsense mutation in exon 15 of TSC1 and established an isogenic set of heterozygous (Het), null and corrected wildtype (Corr-WT) iPSCs using CRISPR/Cas9-mediated gene editing. We differentiated these iPSCs into neural progenitor cells (NPCs) and examined neurodevelopmental phenotypes, signaling and changes in gene expression by RNA-seq. RESULTS: Differentiated NPCs revealed enlarged cell size in TSC1-Het and Null NPCs, consistent with mTORC1 activation. TSC1-Het and Null NPCs also revealed enhanced proliferation and altered neurite outgrowth in a genotype-dependent manner, which was not reversed by rapamycin. Transcriptome analyses of TSC1-NPCs revealed differentially expressed genes that display a genotype-dependent linear response, i.e., genes upregulated/downregulated in Het were further increased/decreased in Null. In particular, genes linked to ASD, epilepsy, and ID were significantly upregulated or downregulated warranting further investigation. In TSC1-Het and Null NPCs, we also observed basal activation of ERK1/2, which was further activated upon rapamycin treatment. Rapamycin also increased MNK1/2-eIF4E signaling in TSC1-deficient NPCs. CONCLUSION: MEK-ERK and MNK-eIF4E pathways regulate protein translation, and our results suggest that aberrant translation distinct in TSC1/2-deficient NPCs could play a role in neurodevelopmental defects. Our data showing upregulation of these signaling pathways by rapamycin support a strategy to combine a MEK or a MNK inhibitor with rapamycin that may be superior for TSC-associated CNS defects. Importantly, our generation of isogenic sets of NPCs from TSC patients provides a valuable platform for translatome and large-scale drug screening studies. Overall, our studies further support the notion that early developmental events such as NPC proliferation and initial process formation, such as neurite number and length that occur prior to neuronal differentiation, represent primary events in neurogenesis critical to disease pathogenesis of neurodevelopmental disorders such as ASD. En ligne : http://dx.doi.org/10.1186/s13229-019-0311-3 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=427 [article] TSC patient-derived isogenic neural progenitor cells reveal altered early neurodevelopmental phenotypes and rapamycin-induced MNK-eIF4E signaling [Texte imprimé et/ou numérique] / Pauline MARTIN, Auteur ; Vilas WAGH, Auteur ; Surya A. REIS, Auteur ; Serkan ERDIN, Auteur ; Roberta L. BEAUCHAMP, Auteur ; Ghalib SHAIKH, Auteur ; Michael E. TALKOWSKI, Auteur ; Elizabeth THIELE, Auteur ; Steven D. SHERIDAN, Auteur ; Stephen J. HAGGARTY, Auteur ; Vijaya RAMESH, Auteur . - 2 p. Langues : Anglais (eng) in Molecular Autism > 11 (2020) . - 2 p. Mots-clés : CRISPR/Cas9  Disease modeling  Early neurodevelopment  Induced pluripotent stem cells  mek-erk1/2  MNK1/2-eIF4E  Neural progenitor cells  tsc1  Tuberous sclerosis complex  mTORC1  Therapeutics, Psy Therapeutics, and Souvien Therapeutics, none of who were involved  in this study. SDS is a scientific advisor for Outermost Therapeutics, Inc., which  played no part in the present study. The other authors declare no competing  interests. Index. décimale : PER Périodiques Résumé : BACKGROUND: Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder with frequent occurrence of epilepsy, autism spectrum disorder (ASD), intellectual disability (ID), and tumors in multiple organs. The aberrant activation of mTORC1 in TSC has led to treatment with mTORC1 inhibitor rapamycin as a lifelong therapy for tumors, but TSC-associated neurocognitive manifestations remain unaffected by rapamycin. METHODS: Here, we generated patient-specific, induced pluripotent stem cells (iPSCs) from a TSC patient with a heterozygous, germline, nonsense mutation in exon 15 of TSC1 and established an isogenic set of heterozygous (Het), null and corrected wildtype (Corr-WT) iPSCs using CRISPR/Cas9-mediated gene editing. We differentiated these iPSCs into neural progenitor cells (NPCs) and examined neurodevelopmental phenotypes, signaling and changes in gene expression by RNA-seq. RESULTS: Differentiated NPCs revealed enlarged cell size in TSC1-Het and Null NPCs, consistent with mTORC1 activation. TSC1-Het and Null NPCs also revealed enhanced proliferation and altered neurite outgrowth in a genotype-dependent manner, which was not reversed by rapamycin. Transcriptome analyses of TSC1-NPCs revealed differentially expressed genes that display a genotype-dependent linear response, i.e., genes upregulated/downregulated in Het were further increased/decreased in Null. In particular, genes linked to ASD, epilepsy, and ID were significantly upregulated or downregulated warranting further investigation. In TSC1-Het and Null NPCs, we also observed basal activation of ERK1/2, which was further activated upon rapamycin treatment. Rapamycin also increased MNK1/2-eIF4E signaling in TSC1-deficient NPCs. CONCLUSION: MEK-ERK and MNK-eIF4E pathways regulate protein translation, and our results suggest that aberrant translation distinct in TSC1/2-deficient NPCs could play a role in neurodevelopmental defects. Our data showing upregulation of these signaling pathways by rapamycin support a strategy to combine a MEK or a MNK inhibitor with rapamycin that may be superior for TSC-associated CNS defects. Importantly, our generation of isogenic sets of NPCs from TSC patients provides a valuable platform for translatome and large-scale drug screening studies. Overall, our studies further support the notion that early developmental events such as NPC proliferation and initial process formation, such as neurite number and length that occur prior to neuronal differentiation, represent primary events in neurogenesis critical to disease pathogenesis of neurodevelopmental disorders such as ASD. En ligne : http://dx.doi.org/10.1186/s13229-019-0311-3 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=427

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