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1.
Development ; 151(10)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38655654

RESUMO

Foxg1 masters telencephalic development via a pleiotropic control over its progression. Expressed within the central nervous system (CNS), L1 retrotransposons are implicated in progression of its histogenesis and tuning of its genomic plasticity. Foxg1 represses gene transcription, and L1 elements share putative Foxg1-binding motifs, suggesting the former might limit telencephalic expression (and activity) of the latter. We tested such a prediction, in vivo as well as in engineered primary neural cultures, using loss- and gain-of-function approaches. We found that Foxg1-dependent, transcriptional L1 repression specifically occurs in neopallial neuronogenic progenitors and post-mitotic neurons, where it is supported by specific changes in the L1 epigenetic landscape. Unexpectedly, we discovered that Foxg1 physically interacts with L1-mRNA and positively regulates neonatal neopallium L1-DNA content, antagonizing the retrotranscription-suppressing activity exerted by Mov10 and Ddx39a helicases. To the best of our knowledge, Foxg1 represents the first CNS patterning gene acting as a bimodal retrotransposon modulator, limiting transcription of L1 elements and promoting their amplification, within a specific domain of the developing mouse brain.


Assuntos
Fatores de Transcrição Forkhead , Regulação da Expressão Gênica no Desenvolvimento , Neocórtex , Proteínas do Tecido Nervoso , RNA Mensageiro , Animais , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Forkhead/genética , Camundongos , Neocórtex/metabolismo , Neocórtex/embriologia , Neocórtex/crescimento & desenvolvimento , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , Retroelementos/genética , DNA/metabolismo , DNA/genética , Neurônios/metabolismo
2.
Cereb Cortex ; 33(6): 3107-3123, 2023 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35818636

RESUMO

Sizes of neuronal, astroglial and oligodendroglial complements forming the neonatal cerebral cortex largely depend on rates at which pallial stem cells give rise to lineage-committed progenitors and the latter ones progress to mature cell types. Here, we investigated the spatial articulation of pallial stem cells' (SCs) commitment to astrogenesis as well as the progression of committed astroglial progenitors (APs) to differentiated astrocytes, by clonal and kinetic profiling of pallial precursors. We found that caudal-medial (CM) SCs are more prone to astrogenesis than rostro-lateral (RL) ones, while RL-committed APs are more keen to proliferate than CM ones. Next, we assessed the control of these phenomena by 2 key transcription factor genes mastering regionalization of the early cortical primordium, Emx2 and Foxg1, via lentiviral somatic transgenesis, epistasis assays, and ad hoc rescue assays. We demonstrated that preferential CM SCs progression to astrogenesis is promoted by Emx2, mainly via Couptf1, Nfia, and Sox9 upregulation, while Foxg1 antagonizes such progression to some extent, likely via repression of Zbtb20. Finally, we showed that Foxg1 and Emx2 may be implicated-asymmetrically and antithetically-in shaping distinctive proliferative/differentiative behaviors displayed by APs in hippocampus and neocortex.


Assuntos
Neocórtex , Neurogênese , Humanos , Recém-Nascido , Astrócitos/metabolismo , Astrócitos/fisiologia , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Fator I de Transcrição COUP/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Hipocampo/metabolismo , Hipocampo/fisiologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Neocórtex/metabolismo , Neurogênese/genética , Neurogênese/fisiologia , Neurônios/metabolismo , Neurônios/fisiologia , Oligodendroglia/metabolismo , Oligodendroglia/fisiologia
3.
Int J Mol Sci ; 23(3)2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35163265

RESUMO

FOXG1 is an ancient transcription factor gene mastering telencephalic development. A number of distinct structural FOXG1 mutations lead to the "FOXG1 syndrome", a complex and heterogeneous neuropathological entity, for which no cure is presently available. Reconstruction of primary neurodevelopmental/physiological anomalies evoked by these mutations is an obvious pre-requisite for future, precision therapy of such syndrome. Here, as a proof-of-principle, we functionally scored three FOXG1 neuropathogenic alleles, FOXG1G224S, FOXG1W308X, and FOXG1N232S, against their healthy counterpart. Specifically, we delivered transgenes encoding for them to dedicated preparations of murine pallial precursors and quantified their impact on selected neurodevelopmental and physiological processes mastered by Foxg1: pallial stem cell fate choice, proliferation of neural committed progenitors, neuronal architecture, neuronal activity, and their molecular correlates. Briefly, we found that FOXG1G224S and FOXG1W308X generally performed as a gain- and a loss-of-function-allele, respectively, while FOXG1N232S acted as a mild loss-of-function-allele or phenocopied FOXG1WT. These results provide valuable hints about processes misregulated in patients heterozygous for these mutations, to be re-addressed more stringently in patient iPSC-derivative neuro-organoids. Moreover, they suggest that murine pallial cultures may be employed for fast multidimensional profiling of novel, human neuropathogenic FOXG1 alleles, namely a step propedeutic to timely delivery of therapeutic precision treatments.


Assuntos
Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas do Tecido Nervoso/genética , Transtornos do Neurodesenvolvimento/genética , Alelos , Animais , Encéfalo/metabolismo , Córtex Cerebral/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Expressão Gênica/genética , Frequência do Gene/genética , Humanos , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Neurogênese , Neurônios/metabolismo , Cultura Primária de Células , Estudo de Prova de Conceito
4.
Cereb Cortex ; 30(9): 5147-5165, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32383447

RESUMO

Foxg1 is an ancient transcription factor gene orchestrating a number of neurodevelopmental processes taking place in the rostral brain. In this study, we investigated its impact on neocortical activity. We found that mice overexpressing Foxg1 in neocortical pyramidal cells displayed an electroencephalography (EEG) with increased spike frequency and were more prone to kainic acid (KA)-induced seizures. Consistently, primary cultures of neocortical neurons gain-of-function for Foxg1 were hyperactive and hypersynchronized. That reflected an unbalanced expression of key genes encoding for ion channels, gamma aminobutyric acid and glutamate receptors, and was likely exacerbated by a pronounced interneuron depletion. We also detected a transient Foxg1 upregulation ignited in turn by neuronal activity and mediated by immediate early genes. Based on this, we propose that even small changes of Foxg1 levels may result in a profound impact on pyramidal cell activity, an issue relevant to neuronal physiology and neurological aberrancies associated to FOXG1 copy number variations.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Neocórtex/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Células Piramidais/metabolismo , Animais , Variações do Número de Cópias de DNA , Eletroencefalografia , Fatores de Transcrição Forkhead/genética , Camundongos , Proteínas do Tecido Nervoso/genética , Convulsões/genética , Convulsões/metabolismo , Regulação para Cima
5.
Nucleic Acids Res ; 47(20): 10728-10743, 2019 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-31584077

RESUMO

Friedreich's ataxia (FRDA) is an untreatable disorder with neuro- and cardio-degenerative progression. This monogenic disease is caused by the hyper-expansion of naturally occurring GAA repeats in the first intron of the FXN gene, encoding for frataxin, a protein implicated in the biogenesis of iron-sulfur clusters. As the genetic defect interferes with FXN transcription, FRDA patients express a normal frataxin protein but at insufficient levels. Thus, current therapeutic strategies are mostly aimed to restore physiological FXN expression. We have previously described SINEUPs, natural and synthetic antisense long non-coding RNAs, which promote translation of partially overlapping mRNAs through the activity of an embedded SINEB2 domain. Here, by in vitro screening, we have identified a number of SINEUPs targeting human FXN mRNA and capable to up-regulate frataxin protein to physiological amounts acting at the post-transcriptional level. Furthermore, FXN-specific SINEUPs promote the recovery of disease-associated mitochondrial aconitase defects in FRDA-derived cells. In summary, we provide evidence that SINEUPs may be the first gene-specific therapeutic approach to activate FXN translation in FRDA and, more broadly, a novel scalable platform to develop new RNA-based therapies for haploinsufficient diseases.


Assuntos
Ataxia de Friedreich/genética , Regulação da Expressão Gênica , Proteínas de Ligação ao Ferro/genética , Modelos Biológicos , RNA não Traduzido/metabolismo , Aconitato Hidratase/metabolismo , Linhagem Celular , Fibroblastos/metabolismo , Humanos , Linfócitos/metabolismo , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA não Traduzido/genética , Frataxina
6.
Cereb Cortex ; 29(3): 1006-1019, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29385539

RESUMO

The architecture of neocortical projection neurons is subject of a complex gene control. Here we demonstrated that Foxg1, a transcription factor gene which patterns the early rostral brain and sets the pace of telencephalic neuronogenesis, specifically stimulates dendrite elongation. This phenomenon occurs in vivo like in vitro, and it is detectable even upon moderate changes of Foxg1 expression levels. We found that Foxg1 acts by stimulating Hes1, which in turn upregulates pCreb1, a well-known pro-dendritogenic effector, and downregulates Syt and Ndr1, namely two established antagonizers of dendrite elongation. Moreover, Foxg1-driven pCreb1 upregulation requires PKA and AKT, and correlates with reduced PP1 and PP2A phosphatase activity. These findings contribute to clarify normal neurodevelopmental and activity-related regulation of neuritogenesis. They further suggest that an abnormal sizing of the dendritic tree of neocortical projection neurons may occur in West and Rett syndrome patients with anomalous FOXG1 allele dosages and contribute to their neurolopathological profiles.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Dendritos/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Neocórtex/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Células Piramidais/metabolismo , Fatores de Transcrição HES-1/metabolismo , Animais , Células Cultivadas , Regulação para Baixo , Feminino , Regulação da Expressão Gênica , Masculino , Camundongos , Fosforilação , Transdução de Sinais , Regulação para Cima
7.
Cereb Cortex ; 29(12): 4903-4918, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-30821834

RESUMO

Neocortical astrogenesis follows neuronogenesis and precedes oligogenesis. Among key factors dictating its temporal articulation, there are progression rates of pallial stem cells (SCs) towards astroglial lineages as well as activation rates of astrocyte differentiation programs in response to extrinsic gliogenic cues. In this study, we showed that high Foxg1 SC expression antagonizes astrocyte generation, while stimulating SC self-renewal and committing SCs to neuronogenesis. We found that mechanisms underlying this activity are mainly cell autonomous and highly pleiotropic. They include a concerted downregulation of 4 key effectors channeling neural SCs to astroglial fates, as well as defective activation of core molecular machineries implementing astroglial differentiation programs. Next, we found that SC Foxg1 levels specifically decline during the neuronogenic-to-gliogenic transition, pointing to a pivotal Foxg1 role in temporal modulation of astrogenesis. Finally, we showed that Foxg1 inhibits astrogenesis from human neocortical precursors, suggesting that this is an evolutionarily ancient trait.


Assuntos
Astrócitos/citologia , Fatores de Transcrição Forkhead/metabolismo , Neocórtex/embriologia , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/citologia , Neurogênese/fisiologia , Animais , Astrócitos/metabolismo , Diferenciação Celular/fisiologia , Humanos , Camundongos , Neocórtex/metabolismo , Células-Tronco Neurais/metabolismo
8.
J Neurosci ; 38(42): 9105-9121, 2018 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-30143575

RESUMO

Specification of dorsoventral regional identity in progenitors of the developing telencephalon is a first pivotal step in the development of the cerebral cortex and basal ganglia. Previously, we demonstrated that the two zinc finger doublesex and mab-3 related (Dmrt) genes, Dmrt5 (Dmrta2) and Dmrt3, which are coexpressed in high caudomedial to low rostrolateral gradients in the cerebral cortical primordium, are separately needed for normal formation of the cortical hem, hippocampus, and caudomedial neocortex. We have now addressed the role of Dmrt3 and Dmrt5 in controlling dorsoventral division of the telencephalon in mice of either sex by comparing the phenotypes of single knock-out (KO) with double KO embryos and by misexpressing Dmrt5 in the ventral telencephalon. We find that DMRT3 and DMRT5 act as critical regulators of progenitor cell dorsoventral identity by repressing ventralizing regulators. Early ventral fate transcriptional regulators expressed in the dorsal lateral ganglionic eminence, such as Gsx2, are upregulated in the dorsal telencephalon of Dmrt3;Dmrt5 double KO embryos and downregulated when ventral telencephalic progenitors express ectopic Dmrt5 Conditional overexpression of Dmrt5 throughout the telencephalon produces gene expression and structural defects that are highly consistent with reduced GSX2 activity. Further, Emx2;Dmrt5 double KO embryos show a phenotype similar to Dmrt3;Dmrt5 double KO embryos, and both DMRT3, DMRT5 and the homeobox transcription factor EMX2 bind to a ventral telencephalon-specific enhancer in the Gsx2 locus. Together, our findings uncover cooperative functions of DMRT3, DMRT5, and EMX2 in dividing dorsal from ventral in the telencephalon.SIGNIFICANCE STATEMENT We identified the DMRT3 and DMRT5 zinc finger transcription factors as novel regulators of dorsoventral patterning in the telencephalon. Our data indicate that they have overlapping functions and compensate for one another. The double, but not the single, knock-out produces a dorsal telencephalon that is ventralized, and olfactory bulb tissue takes over most remaining cortex. Conversely, overexpressing Dmrt5 throughout the telencephalon causes expanded expression of dorsal gene determinants and smaller olfactory bulbs. Furthermore, we show that the homeobox transcription factor EMX2 that is coexpressed with DMRT3 and DMRT5 in cortical progenitors cooperates with them to maintain dorsoventral patterning in the telencephalon. Our study suggests that DMRT3/5 function with EMX2 in positioning the pallial-subpallial boundary by antagonizing the ventral homeobox transcription factor GSX2.


Assuntos
Proteínas de Homeodomínio/fisiologia , Células-Tronco Neurais/fisiologia , Neurônios/fisiologia , Telencéfalo/embriologia , Fatores de Transcrição/fisiologia , Animais , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células-Tronco Neurais/metabolismo , Neurônios/metabolismo , Telencéfalo/metabolismo , Fatores de Transcrição/genética
9.
Nucleic Acids Res ; 43(16): 7850-64, 2015 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-26152305

RESUMO

To promote expression of endogenous genes ad libitum, we developed a novel, programmable transcription factor prototype. Kept together via an MS2 coat protein/RNA interface, it includes a fixed, polypeptidic transactivating domain and a variable RNA domain that recognizes the desired gene. Thanks to this device, we specifically upregulated five genes, in cell lines and primary cultures of murine pallial precursors. Gene upregulation was small, however sufficient to robustly inhibit neuronal differentiation. The transactivator interacted with target gene chromatin via its RNA cofactor. Its activity was restricted to cells in which the target gene is normally transcribed. Our device might be useful for specific applications. However for this purpose, it will require an improvement of its transactivation power as well as a better characterization of its target specificity and mechanism of action.


Assuntos
RNA/metabolismo , Transativadores/química , Ativação Transcricional , Animais , Encéfalo/metabolismo , Células Cultivadas , Células HEK293 , Humanos , Camundongos , Células-Tronco Neurais/metabolismo , Estrutura Terciária de Proteína , RNA/química , Transativadores/metabolismo , Regulação para Cima
10.
Adv Exp Med Biol ; 983: 23-39, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28639189

RESUMO

Small activating RNAs (saRNAs), targeting endogenous genes and stimulating their transcription, are a promising tool for implementing a variety of neurotherapeutic strategies. Among these there is the stimulation of select histogenetic subroutines for purposes of cell-based brain repair, as well as the therapeutic treatment of gene expression deficits underlying severe neurological disorders.We employed RNA activation (RNAa) to transactivate the Emx2 transcription factor gene in embryonic cortico-cerebral precursor cells. This led to enhanced self-renewal, delayed differentiation, and reduced death of neuronally committed precursors, resulting in a remarkable expansion of the neuronogenic precursors pool. These results are of paramount interest for purposes of gene-promoted brain repair. As such, RNAa makes therapeutic stimulation of neuronogenesis via Emx2 overexpression a feasible goal, preventing the drawbacks of exogenous gene copies introduction.Moreover, we employed RNAa to achieve a gentle transactivation of the Foxg1 transcription factor gene, specifically in cortico-cerebral cells. This manipulation led to an appreciable biological outcome, while complying with endogenous gene tuning linked to early central nervous system regionalization and late activity of neocortical projection neurons. Foxg1-activating miRNAs stimulated RNApolII recruitment, possibly via Ago1. One of them worked promisingly in vivo. As such, RNAa can be a valuable approach for therapeutic treatment of the FOXG1-haploinsufficiency-linked variant of the Rett syndrome. Remarkably, hemizygosity for specific genes and polygenic chromosomal segments underlies a huge number of neuropathological entities for which no cure is presently available. Based on the results reported above, RNAa might be a simple and scalable approach for fixing this class of problems.


Assuntos
Haploinsuficiência , Neurogênese , Pequeno RNA não Traduzido/genética , Ativação Transcricional , Diferenciação Celular , Fatores de Transcrição Forkhead/genética , Humanos , Proteínas do Tecido Nervoso/genética , Síndrome de Rett
11.
Glia ; 63(3): 412-22, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25327963

RESUMO

Generation of astrocytes within the developing cerebral cortex is a tightly regulated process, initiating at low level in the middle of neuronogenesis and peaking up after its completion. Astrocytic outputs depend on two primary factors: progression of multipotent precursors toward the astroglial lineage and sizing of the astrogenic proliferating pool. The aim of this study was to investigate the role of the Emx2 homeobox gene in the latter process. We addressed this issue by combined gain- and loss-of-function methods, in vivo as well as in primary cultures of cortico-cerebral precursors. We found that Emx2 overexpression in cortico-cerebral stem cells shrinked the proliferating astrogenic pool, resulting in a severe reduction of the astroglial outcome. We showed that this was caused by EgfR and Fgf9 downregulation and that both phenomena originated from exaggerated Bmp signaling and Sox2 repression. Finally, we provided evidence that in vivo temporal progression of Emx2 levels in cortico-cerebral multipotent precursors contributes to confine the bulk of astrogenesis to postnatal life. Emx2 regulation of astrogenesis adds to a number of earlier developmental processes mastered by this gene. It points to Emx2 as a new promising tool for controlling reactive astrogliosis and optimizing cell-based designs for brain repair.


Assuntos
Astrócitos/fisiologia , Diferenciação Celular/fisiologia , Receptores ErbB/metabolismo , Fator 9 de Crescimento de Fibroblastos/metabolismo , Proteínas de Homeodomínio/metabolismo , Células-Tronco Neurais/fisiologia , Fatores de Transcrição/metabolismo , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Células Cultivadas , Córtex Cerebral/crescimento & desenvolvimento , Córtex Cerebral/fisiologia , Proteínas de Homeodomínio/genética , Camundongos , Camundongos Transgênicos , RNA Mensageiro/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética
12.
Cereb Cortex ; 23(11): 2552-67, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22923088

RESUMO

Regional patterning of the cerebral cortex is initiated by morphogens secreted by patterning centers that establish graded expression of transcription factors within cortical progenitors. Here, we show that Dmrt5 is expressed in cortical progenitors in a high-caudomedial to low-rostrolateral gradient. In its absence, the cortex is strongly reduced and exhibits severe abnormalities, including agenesis of the hippocampus and choroid plexus and defects in commissural and thalamocortical tracts. Loss of Dmrt5 results in decreased Wnt and Bmp in one of the major telencephalic patterning centers, the dorsomedial telencephalon, and in a reduction of Cajal-Retzius cells. Expression of the dorsal midline signaling center-dependent transcription factors is downregulated, including Emx2, which promotes caudomedial fates, while the rostral determinant Pax6, which is inhibited by midline signals, is upregulated. Consistently, Dmrt5(-/-) brains exhibit patterning defects with a dramatic reduction of the caudomedial cortex. Dmrt5 is increased upon the activation of Wnt signaling and downregulated in Gli3(xt/xt) mutants. We conclude that Dmrt5 is a novel Wnt-dependent transcription factor required for early cortical development and that it may regulate initial cortical patterning by promoting dorsal midline signaling center formation and thereby helping to establish the graded expression of the other transcription regulators of cortical identity.


Assuntos
Córtex Cerebral/embriologia , Fatores de Transcrição/metabolismo , Animais , Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Córtex Cerebral/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fatores de Transcrição/genética , Proteínas Wnt/metabolismo
13.
Mol Cell Neurosci ; 57: 42-53, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24128663

RESUMO

In this study, we assayed the capability of four genes implicated in embryonic specification of the cortico-cerebral field, Foxg1, Pax6, Emx2 and Lhx2, to reprogramme mouse embryonic fibroblasts towards neural identities. Lentivirus-mediated, TetON-dependent overexpression of Pax6 and Foxg1 transgenes specifically activated the neural stem cell (NSC) reporter Sox1-EGFP in a substantial fraction of engineered cells. The efficiency of this process was enhanced up to ten times by simultaneous inactivation of Trp53 and co-administration of a specific drug mix inhibiting HDACs, H3K27-HMTase and H3K4m2-demethylase. Remarkably, a fraction of the reprogrammed population expressed other NSC markers and retained its new identity, even after switching off the reprogramming transgenes. When transferred into a pro-differentiative environment, Pax6/Foxg1-overexpressing cells activated the neuronal marker Tau-EGFP. Frequency of Tau-EGFP positive cells was almost doubled upon delayed delivery of Emx2 and Lhx2 transgenes. A further improvement of the neuron-like cell output was achieved by inhibition of the BMP and TGFß pathways. Tau-EGFP positive cells were able to generate action potentials upon injection of depolarizing current pulses, further indicating their neuron-like phenotype.


Assuntos
Reprogramação Celular , Fibroblastos/citologia , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Neurais/citologia , Neurogênese , Animais , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Encéfalo/citologia , Encéfalo/embriologia , Encéfalo/metabolismo , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Fibroblastos/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteínas com Homeodomínio LIM/genética , Proteínas com Homeodomínio LIM/metabolismo , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/metabolismo , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteínas tau/genética , Proteínas tau/metabolismo
14.
Am J Pathol ; 180(3): 1121-1135, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22234171

RESUMO

Protein synthesis is a tightly regulated, energy-consuming process. The control of mRNA translation into protein is fundamentally important for the fine-tuning of gene expression; additionally, precise translational control plays a critical role in many cellular processes, including development, cellular growth, proliferation, differentiation, synaptic plasticity, memory, and learning. Eukaryotic translation initiation factor 4h (Eif4h) encodes a protein involved in the process of protein synthesis, at the level of initiation phase. Its human homolog, WBSCR1, maps on 7q11.23, inside the 1.6 Mb region that is commonly deleted in patients affected by the Williams-Beuren syndrome, which is a complex neurodevelopmental disorder characterized by cardiovascular defects, cerebral dysplasias and a peculiar cognitive-behavioral profile. In this study, we generated knockout mice deficient in Eif4h. These mice displayed growth retardation with a significant reduction of body weight that began from the first week of postnatal development. Neuroanatomical profiling results generated by magnetic resonance imaging analysis revealed a smaller brain volume in null mice compared with controls as well as altered brain morphology, where anterior and posterior brain regions were differentially affected. The inactivation of Eif4h also led to a reduction in both the number and complexity of neurons. Behavioral studies revealed severe impairments of fear-related associative learning and memory formation. These alterations suggest that Eif4h might contribute to certain deficits associated with Williams-Beuren syndrome.


Assuntos
Fatores de Iniciação em Eucariotos/deficiência , Fatores de Iniciação em Eucariotos/genética , Transtornos do Crescimento/genética , Deficiências da Aprendizagem/genética , Transtornos da Memória/genética , Síndrome de Williams/genética , Animais , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Condicionamento Psicológico/fisiologia , Fatores de Iniciação em Eucariotos/metabolismo , Comportamento Exploratório/fisiologia , Medo , Feminino , Deleção de Genes , Heterozigoto , Masculino , Camundongos , Camundongos Knockout , Fadiga Muscular/genética , Mutagênese Insercional , Tamanho do Órgão , Desempenho Psicomotor/fisiologia , RNA Mensageiro/metabolismo , Síndrome de Williams/psicologia
15.
Stem Cells ; 28(7): 1206-18, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20506244

RESUMO

Neural stem cells (NSCs) give rise to all cell types forming the cortex: neurons, astrocytes, and oligodendrocytes. The transition from the former to the latter ones takes place via lineage-restricted progenitors in a highly regulated way. This process is mastered by large sets of genes, among which some implicated in central nervous system pattern formation. The aim of this study was to disentangle the kinetic and histogenetic roles exerted by two of these genes, Emx2 and Foxg1, in cortico-cerebral precursors. For this purpose, we set up a new integrated in vitro assay design. Embryonic cortical progenitors were transduced with lentiviral vectors driving overexpression of Emx2 and Foxg1 in NSCs and neuronal progenitors. Cells belonging to different neuronogenic and gliogenic compartments were labeled by spectrally distinguishable fluoroproteins driven by cell type-specific promoters and by cell type-specific antibodies and were scored via multiplex cytofluorometry and immunocytofluorescence. A detailed picture of Emx2 and Foxg1 activities in cortico-cerebral histogenesis resulted from this study. Unexpectedly, we found that both genes inhibit gliogenesis and promote neuronogenesis, through distinct mechanisms, and Foxg1 also dramatically stimulates neurite outgrowth. Remarkably, such activities, alone or combined, may be exploited to ameliorate the neuronal output obtainable from neural cultures, for purposes of cell-based brain repair.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Proteínas de Homeodomínio/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurogênese , Neuroglia/metabolismo , Neurônios/metabolismo , Células-Tronco/metabolismo , Fatores de Transcrição/metabolismo , Animais , Diferenciação Celular , Crescimento Celular , Células Cultivadas , Feminino , Fatores de Transcrição Forkhead/genética , Proteínas de Homeodomínio/genética , Camundongos , Proteínas do Tecido Nervoso/genética , Neuroglia/citologia , Neurônios/citologia , Células-Tronco/citologia , Fatores de Transcrição/genética
16.
Cell Rep ; 36(11): 109694, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34525372

RESUMO

Chromatin organization plays a crucial role in tissue homeostasis. Heterochromatin relaxation and consequent unscheduled mobilization of transposable elements (TEs) are emerging as key contributors of aging and aging-related pathologies, including Alzheimer's disease (AD) and cancer. However, the mechanisms governing heterochromatin maintenance or its relaxation in pathological conditions remain poorly understood. Here we show that PIN1, the only phosphorylation-specific cis/trans prolyl isomerase, whose loss is associated with premature aging and AD, is essential to preserve heterochromatin. We demonstrate that this PIN1 function is conserved from Drosophila to humans and prevents TE mobilization-dependent neurodegeneration and cognitive defects. Mechanistically, PIN1 maintains nuclear type-B Lamin structure and anchoring function for heterochromatin protein 1α (HP1α). This mechanism prevents nuclear envelope alterations and heterochromatin relaxation under mechanical stress, which is a key contributor to aging-related pathologies.


Assuntos
Proteínas de Drosophila/metabolismo , Heterocromatina/metabolismo , Lamina Tipo B/metabolismo , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Peptidilprolil Isomerase/metabolismo , Estresse Mecânico , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Células Cultivadas , Homólogo 5 da Proteína Cromobox/genética , Homólogo 5 da Proteína Cromobox/metabolismo , Elementos de DNA Transponíveis/genética , Drosophila/metabolismo , Proteínas de Drosophila/antagonistas & inibidores , Proteínas de Drosophila/genética , Humanos , Lamina Tipo B/química , Camundongos , Camundongos Endogâmicos C57BL , Peptidilprolil Isomerase de Interação com NIMA/antagonistas & inibidores , Peptidilprolil Isomerase de Interação com NIMA/genética , Neocórtex/citologia , Neocórtex/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Membrana Nuclear/química , Peptidilprolil Isomerase/antagonistas & inibidores , Peptidilprolil Isomerase/genética , Fosforilação , Interferência de RNA , RNA Interferente Pequeno/metabolismo
17.
RNA Biol ; 7(5): 528-33, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20523124

RESUMO

miRNAs are essential post-transcriptional modulators affecting cell identity and fate, with a central role in cellular and developmental processes. The brain-enriched neuronal specific miRNAs-124 has been identified as a promoter of neuronogenesis in various conditions, in vitro and in vivo, with a potential role in regulating also activities of post-mitotic neurons, such as synaptic plasticity and memory formation. In this point of view, we recapitulate the main experimental findings substantiating the positive correlation between miR-124 expression and neuronogenesis progression. Then, we describe the impact of miR-124 on the molecular network driving the profound changes which take place in differentiating neuronal cells. Finally, we consider the possibility of a post-transcriptional modulation of miR-124 biogenesis, which may finely regulate--in turn--the activities of miR-124 in neural precursor cells.


Assuntos
MicroRNAs/metabolismo , Neurogênese , Neurônios/citologia , Animais , Humanos , MicroRNAs/genética , Neurônios/metabolismo , Processamento Pós-Transcricional do RNA
18.
J Vis Exp ; (147)2019 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-31132045

RESUMO

Gene control of neuronal cytoarchitecture is currently the subject of intensive investigation. Described here is a simple method developed to study in vivo gene control of neocortical projection neuron morphology. This method is based on (1) in vitro lentiviral engineering of neuronal precursors as "test" and "control" cells, (2) their co-transplantation into wild-type brains, and (3) paired morphometric evaluation of their neuronal derivatives. Specifically, E12.5 pallial precursors from panneuronal, genetically labeled donors, are employed for this purpose. They are engineered to take advantage of selected promoters and tetON/OFF technology, and they are free-hand transplanted into neonatal lateral ventricles. Later, upon immunofluorescence profiling of recipient brains, silhouettes of transplanted neurons are fed into NeurphologyJ open source software, their morphometric parameters are extracted, and average length and branching index are calculated. Compared to other methods, this one offers three main advantages: it permits achieving of fine control of transgene expression at affordable costs, it only requires basic surgical skills, and it provides statistically reliable results upon analysis of a limited number of animals. Because of its design, however, it is not adequate to address non cell-autonomous control of neuroarchitecture. Moreover, it should be preferably used to investigate neurite morphology control after completion of neuronal migration. In its present formulation, this method is exquisitely tuned to investigate gene control of glutamatergic neocortical neuron architecture. Taking advantage of transgenic lines expressing EGFP in other specific neural cell types, it can be re-purposed to address gene control of their architecture.


Assuntos
Ventrículos Cerebrais/citologia , Células-Tronco Neurais/transplante , Animais , Diferenciação Celular/genética , Movimento Celular , Feminino , Masculino , Camundongos , Neuritos , Neurônios/fisiologia , Engenharia Tecidual
19.
Nat Neurosci ; 5(8): 737-45, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12118260

RESUMO

The molecular mechanisms that activate morphogenesis of cerebral cortex are currently the subject of intensive experimental analysis. Transcription factor genes of the homeobox, basic helix-loop-helix (bHLH) and zinc-finger families have recently been shown to have essential roles in this process. However, the actual selector genes activating corticogenesis have not yet been identified. Here we show that high-level expression of at least one functional allele of either of the homeobox genes Emx2 or Pax6 in the dorsal telencephalon is necessary and sufficient to stably activate morphogenesis of cerebral cortex and to repress that of adjacent structures, such as striatum.


Assuntos
Gânglios da Base/anormalidades , Córtex Cerebral/anormalidades , Proteínas de Homeodomínio/metabolismo , Malformações do Sistema Nervoso/embriologia , Alelos , Animais , Antígenos de Diferenciação/biossíntese , Antígenos de Diferenciação/genética , Gânglios da Base/metabolismo , Gânglios da Base/patologia , Diferenciação Celular , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Regulação para Baixo , Proteínas do Olho , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/genética , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Camundongos Knockout , Camundongos Mutantes , Morfogênese , Malformações do Sistema Nervoso/metabolismo , Malformações do Sistema Nervoso/patologia , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Proteínas Repressoras , Células-Tronco/citologia , Fatores de Transcrição
20.
Prog Neurobiol ; 155: 194-211, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27887908

RESUMO

The post-genomic era has unveiled the existence of a large repertory of non-coding RNAs and repetitive elements that play a fundamental role in cellular homeostasis and dysfunction. These may represent unprecedented opportunities to modify gene expression at the right time in the correct space in vivo, providing an almost unlimited reservoir of new potential pharmacological agents. Hijacking their mode of actions, the druggable genome can be extended to regulatory RNAs and DNA elements in a scalable fashion. Here, we discuss the state-of-the-art of nucleic acid-based drugs to treat neurodegenerative diseases. Beneficial effects can be obtained by inhibiting (Yin) and increasing (Yang) gene expression, depending on the disease and the drug target. Together with the description of the current use of inhibitory RNAs (small inhibitory RNAs and antisense oligonucleotides) in animal models and clinical trials, we discuss the molecular basis and applications of new classes of activatory RNAs at transcriptional (RNAa) and translational (SINEUP) levels.


Assuntos
Encéfalo/efeitos dos fármacos , Doenças Neurodegenerativas/tratamento farmacológico , Ácidos Nucleicos/farmacologia , Animais , Humanos
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