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1.
Cell ; 185(16): 3025-3040.e6, 2022 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-35882231

RESUMO

Non-allelic recombination between homologous repetitive elements contributes to evolution and human genetic disorders. Here, we combine short- and long-DNA read sequencing of repeat elements with a new bioinformatics pipeline to show that somatic recombination of Alu and L1 elements is widespread in the human genome. Our analysis uncovers tissue-specific non-allelic homologous recombination hallmarks; moreover, we find that centromeres and cancer-associated genes are enriched for retroelements that may act as recombination hotspots. We compare recombination profiles in human-induced pluripotent stem cells and differentiated neurons and find that the neuron-specific recombination of repeat elements accompanies chromatin changes during cell-fate determination. Finally, we report that somatic recombination profiles are altered in Parkinson's and Alzheimer's disease, suggesting a link between retroelement recombination and genomic instability in neurodegeneration. This work highlights a significant contribution of the somatic recombination of repeat elements to genomic diversity in health and disease.


Assuntos
Genoma Humano , Retroelementos , Elementos Alu/genética , Recombinação Homóloga , Humanos , Elementos Nucleotídeos Longos e Dispersos , Sequências Repetitivas de Ácido Nucleico
2.
Am J Hum Genet ; 111(3): 529-543, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38387458

RESUMO

The Rab family of guanosine triphosphatases (GTPases) includes key regulators of intracellular transport and membrane trafficking targeting specific steps in exocytic, endocytic, and recycling pathways. DENND5B (Rab6-interacting Protein 1B-like protein, R6IP1B) is the longest isoform of DENND5, an evolutionarily conserved DENN domain-containing guanine nucleotide exchange factor (GEF) that is highly expressed in the brain. Through exome sequencing and international matchmaking platforms, we identified five de novo variants in DENND5B in a cohort of five unrelated individuals with neurodevelopmental phenotypes featuring cognitive impairment, dysmorphism, abnormal behavior, variable epilepsy, white matter abnormalities, and cortical gyration defects. We used biochemical assays and confocal microscopy to assess the impact of DENND5B variants on protein accumulation and distribution. Then, exploiting fluorescent lipid cargoes coupled to high-content imaging and analysis in living cells, we investigated whether DENND5B variants affected the dynamics of vesicle-mediated intracellular transport of specific cargoes. We further generated an in silico model to investigate the consequences of DENND5B variants on the DENND5B-RAB39A interaction. Biochemical analysis showed decreased protein levels of DENND5B mutants in various cell types. Functional investigation of DENND5B variants revealed defective intracellular vesicle trafficking, with significant impairment of lipid uptake and distribution. Although none of the variants affected the DENND5B-RAB39A interface, all were predicted to disrupt protein folding. Overall, our findings indicate that DENND5B variants perturb intracellular membrane trafficking pathways and cause a complex neurodevelopmental syndrome with variable epilepsy and white matter involvement.


Assuntos
Epilepsia , Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Humanos , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/metabolismo , Encéfalo/metabolismo , Epilepsia/genética , Epilepsia/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Lipídeos , Deficiência Intelectual/genética , Deficiência Intelectual/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo
3.
Chem Rev ; 124(8): 4734-4777, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38579177

RESUMO

This comprehensive Review delves into the chemical principles governing RNA-mediated crowding events, commonly referred to as granules or biological condensates. We explore the pivotal role played by RNA sequence, structure, and chemical modifications in these processes, uncovering their correlation with crowding phenomena under physiological conditions. Additionally, we investigate instances where crowding deviates from its intended function, leading to pathological consequences. By deepening our understanding of the delicate balance that governs molecular crowding driven by RNA and its implications for cellular homeostasis, we aim to shed light on this intriguing area of research. Our exploration extends to the methodologies employed to decipher the composition and structural intricacies of RNA granules, offering a comprehensive overview of the techniques used to characterize them, including relevant computational approaches. Through two detailed examples highlighting the significance of noncoding RNAs, NEAT1 and XIST, in the formation of phase-separated assemblies and their influence on the cellular landscape, we emphasize their crucial role in cellular organization and function. By elucidating the chemical underpinnings of RNA-mediated molecular crowding, investigating the role of modifications, structures, and composition of RNA granules, and exploring both physiological and aberrant phase separation phenomena, this Review provides a multifaceted understanding of the intriguing world of RNA-mediated biological condensates.


Assuntos
RNA , RNA/química , RNA/metabolismo , Humanos , Substâncias Macromoleculares/química , Substâncias Macromoleculares/metabolismo , Animais , Conformação de Ácido Nucleico
4.
Development ; 149(20)2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-35993299

RESUMO

Using the timely re-activation of WNT signalling in neuralizing human induced pluripotent stem cells (hiPSCs), we have produced neural progenitor cells with a gene expression profile typical of human embryonic dentate gyrus (DG) cells. Notably, in addition to continuous WNT signalling, a specific laminin isoform is crucial to prolonging the neural stem state and to extending progenitor cell proliferation for over 200 days in vitro. Laminin 511 is indeed specifically required to support proliferation and to inhibit differentiation of hippocampal progenitor cells for extended time periods when compared with a number of different laminin isoforms assayed. Global gene expression profiles of these cells suggest that a niche of laminin 511 and WNT signalling is sufficient to maintain their capability to undergo typical hippocampal neurogenesis. Moreover, laminin 511 signalling sustains the expression of a set of genes responsible for the maintenance of a hippocampal neurogenic niche. Finally, xenograft of human DG progenitors into the DG of adult immunosuppressed host mice produces efficient integration of neurons that innervate CA3 layer cells spanning the same area of endogenous hippocampal neuron synapses.


Assuntos
Células-Tronco Pluripotentes Induzidas , Laminina , Animais , Diferenciação Celular/genética , Giro Denteado , Hipocampo/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Laminina/metabolismo , Camundongos , Neurogênese/genética , Via de Sinalização Wnt
5.
EMBO Rep ; 24(2): e53801, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36472244

RESUMO

Adult neural progenitor cells (aNPCs) ensure lifelong neurogenesis in the mammalian hippocampus. Proper regulation of aNPC fate has thus important implications for brain plasticity and healthy aging. Piwi proteins and the small noncoding RNAs interacting with them (piRNAs) have been proposed to control memory and anxiety, but the mechanism remains elusive. Here, we show that Piwil2 (Mili) is essential for proper neurogenesis in the postnatal mouse hippocampus. RNA sequencing of aNPCs and their differentiated progeny reveal that Mili and piRNAs are dynamically expressed in neurogenesis. Depletion of Mili and piRNAs in the adult hippocampus impairs aNPC differentiation toward a neural fate, induces senescence, and generates reactive glia. Transcripts modulated upon Mili depletion bear sequences complementary or homologous to piRNAs and include repetitive elements and mRNAs encoding essential proteins for proper neurogenesis. Our results provide evidence of a critical role for Mili in maintaining fitness and proper fate of aNPCs, underpinning a possible involvement of the piRNA pathway in brain plasticity and successful aging.


Assuntos
Proteínas Argonautas , Hipocampo , Neurogênese , Animais , Camundongos , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Senescência Celular/genética , Hipocampo/metabolismo , Mamíferos/genética , Mamíferos/metabolismo , Neurogênese/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
6.
Nucleic Acids Res ; 50(22): 12809-12828, 2022 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-36537238

RESUMO

Disruptive mutations in the chromodomain helicase DNA-binding protein 8 gene (CHD8) have been recurrently associated with autism spectrum disorders (ASDs). Here we investigated how chromatin reacts to CHD8 suppression by analyzing a panel of histone modifications in induced pluripotent stem cell-derived neural progenitors. CHD8 suppression led to significant reduction (47.82%) in histone H3K36me3 peaks at gene bodies, particularly impacting on transcriptional elongation chromatin states. H3K36me3 reduction specifically affects highly expressed, CHD8-bound genes and correlates with altered alternative splicing patterns of 462 genes implicated in 'regulation of RNA splicing' and 'mRNA catabolic process'. Mass spectrometry analysis uncovered a novel interaction between CHD8 and the splicing regulator heterogeneous nuclear ribonucleoprotein L (hnRNPL), providing the first mechanistic insights to explain the CHD8 suppression-derived splicing phenotype, partly implicating SETD2, a H3K36me3 methyltransferase. In summary, our results point toward broad molecular consequences of CHD8 suppression, entailing altered histone deposition/maintenance and RNA processing regulation as important regulatory processes in ASD.


Assuntos
Processamento Alternativo , Caderinas , Histonas , Cromatina , Histonas/metabolismo , Lisina/metabolismo , RNA/metabolismo , Caderinas/genética , Humanos , Células-Tronco Pluripotentes Induzidas , Células-Tronco Neurais , Transtorno do Espectro Autista/genética
7.
Am J Hum Genet ; 107(6): 1129-1148, 2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-33186545

RESUMO

The endosomal sorting complexes required for transport (ESCRTs) are essential for multiple membrane modeling and membrane-independent cellular processes. Here we describe six unrelated individuals with de novo missense variants affecting the ATPase domain of VPS4A, a critical enzyme regulating ESCRT function. Probands had structural brain abnormalities, severe neurodevelopmental delay, cataracts, growth impairment, and anemia. In cultured cells, overexpression of VPS4A mutants caused enlarged endosomal vacuoles resembling those induced by expression of known dominant-negative ATPase-defective forms of VPS4A. Proband-derived fibroblasts had enlarged endosomal structures with abnormal accumulation of the ESCRT protein IST1 on the limiting membrane. VPS4A function was also required for normal endosomal morphology and IST1 localization in iPSC-derived human neurons. Mutations affected other ESCRT-dependent cellular processes, including regulation of centrosome number, primary cilium morphology, nuclear membrane morphology, chromosome segregation, mitotic spindle formation, and cell cycle progression. We thus characterize a distinct multisystem disorder caused by mutations affecting VPS4A and demonstrate that its normal function is required for multiple human developmental and cellular processes.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Mutação de Sentido Incorreto , Transtornos do Neurodesenvolvimento/genética , ATPases Vacuolares Próton-Translocadoras/genética , Alelos , Animais , Encéfalo/anormalidades , Ciclo Celular , Centrossomo/metabolismo , Endossomos/metabolismo , Fibroblastos/metabolismo , Genômica , Células HEK293 , Células HeLa , Humanos , Camundongos , Neurônios/metabolismo , Domínios Proteicos , Transporte Proteico , Fuso Acromático/metabolismo
8.
Bioinformatics ; 38(18): 4430-4433, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35876845

RESUMO

SUMMARY: Transposable elements (TEs) play key roles in crucial biological pathways. Therefore, several tools enabling the quantification of their expression were recently developed. However, many of the existing tools lack the capability to distinguish between the transcription of autonomously expressed TEs and TE fragments embedded in canonical coding/non-coding non-TE transcripts. Consequently, an apparent change in the expression of a given TE may simply reflect the variation in the expression of the transcripts containing TE-derived sequences. To overcome this issue, we have developed TEspeX, a pipeline for the quantification of TE expression at the consensus level. TEspeX uses Illumina RNA-seq short reads to quantify TE expression avoiding counting reads deriving from inactive TE fragments embedded in canonical transcripts. AVAILABILITY AND IMPLEMENTATION: The tool is implemented in python3, distributed under the GNU General Public License (GPL) and available on Github at https://github.com/fansalon/TEspeX (Zenodo URL: https://doi.org/10.5281/zenodo.6800331). SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Elementos de DNA Transponíveis , Sequenciamento de Nucleotídeos em Larga Escala , Consenso , RNA-Seq , Viés
9.
J Chem Inf Model ; 63(21): 6667-6680, 2023 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-37847527

RESUMO

Trace amine-associated receptors (TAARs) were discovered in 2001 as new members of class A G protein-coupled receptors (GPCRs). With the only exception of TAAR1, TAAR members (TAAR2-9, also known as noncanonical olfactory receptors) were originally described exclusively in the olfactory epithelium and believed to mediate the innate perception of volatile amines. However, most noncanonical olfactory receptors are still orphan receptors. Given its recently discovered nonolfactory expression and therapeutic potential, TAAR5 has been the focus of deorphanization campaigns that led to the discovery of a few druglike antagonists. Here, we report four novel TAAR5 antagonists identified through high-throughput screening, which, along with the four ligands published in the literature, constituted our starting point to design a computational strategy for the identification of TAAR5 ligands. We developed a structure-based virtual screening protocol that allowed us to identify three new TAAR5 antagonists with a hit rate of 10%. Despite lacking an experimental structure, we accurately modeled the TAAR5 binding site by integrating comparative sequence- and structure-based analyses of serotonin receptors with homology modeling and side-chain optimization. In summary, we have identified seven new TAAR5 antagonists that could serve as lead candidates for the development of new treatments for depression, anxiety, and neurodegenerative diseases.


Assuntos
Receptores Odorantes , Animais , Camundongos , Receptores Acoplados a Proteínas G/química , Aminas , Sítios de Ligação , Ligantes
10.
BMC Biol ; 20(1): 116, 2022 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-35581640

RESUMO

BACKGROUND: Transposable elements (TEs) widely contribute to the evolution of genomes allowing genomic innovations, generating germinal and somatic heterogeneity, and giving birth to long non-coding RNAs (lncRNAs). These features have been associated to the evolution, functioning, and complexity of the nervous system at such a level that somatic retrotransposition of long interspersed element (LINE) L1 has been proposed to be associated to human cognition. Among invertebrates, octopuses are fascinating animals whose nervous system reaches a high level of complexity achieving sophisticated cognitive abilities. The sequencing of the genome of the Octopus bimaculoides revealed a striking expansion of TEs which were proposed to have contributed to the evolution of its complex nervous system. We recently found a similar expansion also in the genome of Octopus vulgaris. However, a specific search for the existence and the transcription of full-length transpositionally competent TEs has not been performed in this genus. RESULTS: Here, we report the identification of LINE elements competent for retrotransposition in Octopus vulgaris and Octopus bimaculoides and show evidence suggesting that they might be transcribed and determine germline and somatic polymorphisms especially in the brain. Transcription and translation measured for one of these elements resulted in specific signals in neurons belonging to areas associated with behavioral plasticity. We also report the transcription of thousands of lncRNAs and the pervasive inclusion of TE fragments in the transcriptomes of both Octopus species, further testifying the crucial activity of TEs in the evolution of the octopus genomes. CONCLUSIONS: The neural transcriptome of the octopus shows the transcription of thousands of putative lncRNAs and of a full-length LINE element belonging to the RTE class. We speculate that a convergent evolutionary process involving retrotransposons activity in the brain has been important for the evolution of sophisticated cognitive abilities in this genus.


Assuntos
Octopodiformes , RNA Longo não Codificante , Animais , Encéfalo , Elementos de DNA Transponíveis , Feminino , Genoma , Octopodiformes/genética , Gravidez , RNA Longo não Codificante/genética , Retroelementos/genética
11.
Genet Med ; 24(2): 384-397, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34906446

RESUMO

PURPOSE: We aimed to investigate the molecular basis underlying a novel phenotype including hypopituitarism associated with primary ovarian insufficiency. METHODS: We used next-generation sequencing to identify variants in all pedigrees. Expression of Rnpc3/RNPC3 was analyzed by in situ hybridization on murine/human embryonic sections. CRISPR/Cas9 was used to generate mice carrying the p.Leu483Phe pathogenic variant in the conserved murine Rnpc3 RRM2 domain. RESULTS: We described 15 patients from 9 pedigrees with biallelic pathogenic variants in RNPC3, encoding a specific protein component of the minor spliceosome, which is associated with a hypopituitary phenotype, including severe growth hormone (GH) deficiency, hypoprolactinemia, variable thyrotropin (also known as thyroid-stimulating hormone) deficiency, and anterior pituitary hypoplasia. Primary ovarian insufficiency was diagnosed in 8 of 9 affected females, whereas males had normal gonadal function. In addition, 2 affected males displayed normal growth when off GH treatment despite severe biochemical GH deficiency. In both mouse and human embryos, Rnpc3/RNPC3 was expressed in the developing forebrain, including the hypothalamus and Rathke's pouch. Female Rnpc3 mutant mice displayed a reduction in pituitary GH content but with no reproductive impairment in young mice. Male mice exhibited no obvious phenotype. CONCLUSION: Our findings suggest novel insights into the role of RNPC3 in female-specific gonadal function and emphasize a critical role for the minor spliceosome in pituitary and ovarian development and function.


Assuntos
Hipopituitarismo , Insuficiência Ovariana Primária , Animais , Feminino , Humanos , Hipopituitarismo/genética , Masculino , Camundongos , Proteínas Nucleares/genética , Linhagem , Fenótipo , Insuficiência Ovariana Primária/genética , Prolactina/genética , Proteínas de Ligação a RNA/genética
12.
Nucleic Acids Res ; 48(3): 1164-1174, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31889193

RESUMO

Solution nuclear magnetic resonance (NMR) experiments allow RNA dynamics to be determined in an aqueous environment. However, when a limited number of peaks are assigned, it is difficult to obtain structural information. We here show a protocol based on the combination of experimental data (Nuclear Overhauser Effect, NOE) and molecular dynamics simulations with enhanced sampling methods. This protocol allows to (a) obtain a maximum entropy ensemble compatible with NMR restraints and (b) obtain a minimal set of metastable conformations compatible with the experimental data (maximum parsimony). The method is applied to a hairpin of 29 nt from an inverted SINEB2, which is part of the SINEUP family and has been shown to enhance protein translation. A clustering procedure is introduced where the annotation of base-base interactions and glycosidic bond angles is used as a metric. By reweighting the contributions of the clusters, minimal sets of four conformations could be found which are compatible with the experimental data. A motif search on the structural database showed that some identified low-population states are present in experimental structures of other RNA transcripts. The introduced method can be applied to characterize RNA dynamics in systems where a limited amount of NMR information is available.


Assuntos
RNA/química , Análise por Conglomerados , Simulação de Dinâmica Molecular , Ressonância Magnética Nuclear Biomolecular , Conformação de Ácido Nucleico , Motivos de Nucleotídeos
13.
Nucleic Acids Res ; 48(16): 9346-9360, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32697302

RESUMO

Long non-coding RNAs (lncRNAs) are attracting widespread attention for their emerging regulatory, transcriptional, epigenetic, structural and various other functions. Comprehensive transcriptome analysis has revealed that retrotransposon elements (REs) are transcribed and enriched in lncRNA sequences. However, the functions of lncRNAs and the molecular roles of the embedded REs are largely unknown. The secondary and tertiary structures of lncRNAs and their embedded REs are likely to have essential functional roles, but experimental determination and reliable computational prediction of large RNA structures have been extremely challenging. We report here the nuclear magnetic resonance (NMR)-based secondary structure determination of the 167-nt inverted short interspersed nuclear element (SINE) B2, which is embedded in antisense Uchl1 lncRNA and upregulates the translation of sense Uchl1 mRNAs. By using NMR 'fingerprints' as a sensitive probe in the domain survey, we successfully divided the full-length inverted SINE B2 into minimal units made of two discrete structured domains and one dynamic domain without altering their original structures after careful boundary adjustments. This approach allowed us to identify a structured domain in nucleotides 31-119 of the inverted SINE B2. This approach will be applicable to determining the structures of other regulatory lncRNAs.


Assuntos
Conformação de Ácido Nucleico , RNA Longo não Codificante/ultraestrutura , Retroelementos/genética , Elementos Nucleotídeos Curtos e Dispersos/genética , Biologia Computacional , Humanos , Espectroscopia de Ressonância Magnética , RNA Antissenso/genética , RNA Antissenso/ultraestrutura , RNA Longo não Codificante/genética , Transcriptoma/genética , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/ultraestrutura
14.
Nucleic Acids Res ; 48(20): 11626-11644, 2020 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-33130894

RESUMO

SINEUPs are long non-coding RNAs (lncRNAs) that contain a SINE element, and which up-regulate the translation of target mRNA. They have been studied in a wide range of applications, as both biological and therapeutic tools, although the underpinning molecular mechanism is unclear. Here, we focused on the sub-cellular distribution of target mRNAs and SINEUP RNAs, performing co-transfection of expression vectors for these transcripts into human embryonic kidney cells (HEK293T/17), to investigate the network of translational regulation. The results showed that co-localization of target mRNAs and SINEUP RNAs in the cytoplasm was a key phenomenon. We identified PTBP1 and HNRNPK as essential RNA binding proteins. These proteins contributed to SINEUP RNA sub-cellular distribution and to assembly of translational initiation complexes, leading to enhanced target mRNA translation. These findings will promote a better understanding of the mechanisms employed by regulatory RNAs implicated in efficient protein translation.


Assuntos
Ribonucleoproteínas Nucleares Heterogêneas Grupo K/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Iniciação Traducional da Cadeia Peptídica , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , RNA Longo não Codificante/metabolismo , Citoplasma/metabolismo , Proteínas de Fluorescência Verde/análise , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Células HEK293 , Humanos , Proteínas de Ligação a RNA/metabolismo
15.
Int J Mol Sci ; 23(6)2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35328548

RESUMO

Trace amine-associated receptor 5 (TAAR5) is a G protein-coupled receptor that belongs to the TAARs family (TAAR1-TAAR9). TAAR5 is expressed in the olfactory epithelium and is responsible for sensing 3-methylamine (TMA). However, recent studies showed that TAAR5 is also expressed in the limbic brain regions and is involved in the regulation of emotional behaviour and adult neurogenesis, suggesting that TAAR5 antagonism may represent a novel therapeutic strategy for anxiety and depression. We used the AtomNet® model, the first deep learning neural network for structure-based drug discovery, to identify putative TAAR5 ligands and tested them in an in vitro BRET assay. We found two mTAAR5 antagonists with low to submicromolar activity that are able to inhibit the cAMP production induced by TMA. Moreover, these two compounds also inhibited the mTAAR5 downstream signalling, such as the phosphorylation of CREB and ERK. These two hits exhibit drug-like properties and could be used to further develop more potent TAAR5 ligands with putative anxiolytic and antidepressant activity.


Assuntos
Receptores Acoplados a Proteínas G , Transdução de Sinais , Ligantes , Redes Neurais de Computação , Mucosa Olfatória
16.
Clin Immunol ; 231: 108837, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34455097

RESUMO

RAS-associated autoimmune leukoproliferative disease (RALD) is a rare immune dysregulation syndrome caused by somatic gain-of-function mutations of either NRAS or KRAS gene in hematopoietic cells. We describe a 27-year-old patient presenting at 5 months of age with recurrent infections and generalized lymphadenopathy who developed a complex multi-organ autoimmune syndrome with hypogammaglobulinemia, partially controlled with oral steroids, hydroxichloroquine, mofetil mycophenolate and IVIG prophylaxis. Activation of type I interferon pathway was observed in peripheral blood. Since 18 years of age, the patient developed regenerative nodular hyperplasia of the liver evolving into hepatopulmonary syndrome. Whole exome sequencing analysis of the peripheral blood DNA showed the NRAS p.Gly13Asp mutation validated as somatic. Our report highlights the possibility of detecting somatic NRAS gene mutations in patients with inflammatory immune dysregulation and type I interferon activation.


Assuntos
Síndrome Linfoproliferativa Autoimune/genética , Síndrome Linfoproliferativa Autoimune/imunologia , GTP Fosfo-Hidrolases/genética , Interferon Tipo I/imunologia , Hepatopatias/genética , Proteínas de Membrana/genética , Adulto , Síndrome Linfoproliferativa Autoimune/complicações , Humanos , Hepatopatias/imunologia , Mutação
17.
Mol Ther ; 28(2): 642-652, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-31495777

RESUMO

Glial cell-derived neurotrophic factor (GDNF) has a potent action in promoting the survival of dopamine (DA) neurons. Several studies indicate that increasing GDNF levels may be beneficial for the treatment of Parkinson's disease (PD) by reducing neurodegeneration of DA neurons. Despite a plethora of preclinical studies showing GDNF efficacy in PD animal models, its application in humans remains questionable for its poor efficacy and side effects due to its uncontrolled, ectopic expression. Here we took advantage of SINEUPs, a new class of antisense long non-coding RNA, that promote translation of partially overlapping sense protein-coding mRNAs with no effects on their mRNA levels. By synthesizing a SINEUP targeting Gdnf mRNA, we were able to increase endogenous GDNF protein levels by about 2-fold. Adeno-associated virus (AAV)9-mediated delivery in the striatum of wild-type (WT) mice led to an increase of endogenous GDNF protein for at least 6 months and the potentiation of the DA system's functions while showing no side effects. Furthermore, SINEUP-GDNF was able to ameliorate motor deficits and neurodegeneration of DA neurons in a PD neurochemical mouse model. Our data indicate that SINEUP-GDNF could represent a new strategy to increase endogenous GDNF protein levels in a more physiological manner for therapeutic treatments of PD.


Assuntos
Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Neurônios Motores/metabolismo , Doença de Parkinson/genética , Interferência de RNA , RNA não Traduzido/genética , Animais , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Dependovirus/genética , Modelos Animais de Doenças , Neurônios Dopaminérgicos/metabolismo , Regulação da Expressão Gênica , Técnicas de Transferência de Genes , Vetores Genéticos/genética , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Humanos , Imuno-Histoquímica , Camundongos , Neurônios Motores/patologia , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Fenótipo
18.
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
19.
Hum Mutat ; 41(4): 807-824, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31898848

RESUMO

Minisatellites, also called variable number of tandem repeats (VNTRs), are a class of repetitive elements that may affect gene expression at multiple levels and have been correlated to disease. Their identification and role as expression quantitative trait loci (eQTL) have been limited by their absence in comparative genomic hybridization and single nucleotide polymorphisms arrays. By taking advantage of cap analysis of gene expression (CAGE), we describe a new example of a minisatellite hosting a transcription start site (TSS) which expression is dependent on the repeat number. It is located in the third intron of the gene nitrogen permease regulator like protein 3 (NPRL3). NPRL3 is a component of the GAP activity toward rags 1 protein complex that inhibits mammalian target of rapamycin complex 1 (mTORC1) activity and it is found mutated in familial focal cortical dysplasia and familial focal epilepsy. CAGE tags represent an alternative TSS identifying TAGNPRL3 messenger RNAs (mRNAs). TAGNPRL3 is expressed in red blood cells both at mRNA and protein levels, it interacts with its protein partner NPRL2 and its overexpression inhibits cell proliferation. This study provides an example of a minisatellite that is both a TSS and an eQTL as well as identifies a new VNTR that may modify mTORC1 activity.


Assuntos
Proteínas Ativadoras de GTPase/metabolismo , Regulação da Expressão Gênica , Repetições Minissatélites , Sítio de Iniciação de Transcrição , Linhagem Celular , Proteínas Ativadoras de GTPase/genética , Genômica/métodos , Genótipo , Humanos , Íntrons , Família Multigênica , Polimorfismo Genético , Capuzes de RNA , Interferência de RNA , RNA Interferente Pequeno
20.
FASEB J ; 33(12): 13572-13589, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31570000

RESUMO

Transposable elements (TEs) compose about half of the mammalian genome and, as embedded sequences, up to 40% of long noncoding RNA (lncRNA) transcripts. Embedded TEs may represent functional domains within lncRNAs, providing a structured RNA platform for protein interaction. Here we show the interactome profile of the mouse inverted short interspersed nuclear element (SINE) of subfamily B2 (invSINEB2) alone and embedded in antisense (AS) ubiquitin C-terminal hydrolase L1 (Uchl1), an lncRNA that is AS to Uchl1 gene. AS Uchl1 is the representative member of a functional class of AS lncRNAs, named SINEUPs, in which the invSINEB2 acts as effector domain (ED)-enhancing translation of sense protein-coding mRNAs. By using RNA-interacting domainome technology, we identify the IL enhancer-binding factor 3 (ILF3) as a protein partner of AS Uchl1 RNA. We determine that this interaction is mediated by the RNA-binding motif 2 of ILF3 and the invSINEB2. Furthermore, we show that ILF3 is able to bind a free right Arthrobacter luteus (Alu) monomer sequence, the embedded TE acting as ED in human SINEUPs. Bioinformatic analysis of Encyclopedia of DNA Elements-enhanced cross-linking immunoprecipitation data reveals that ILF3 binds transcribed human SINE sequences at transcriptome-wide levels. We then demonstrate that the embedded TEs modulate AS Uchl1 RNA nuclear localization to an extent moderately influenced by ILF3. This work unveils the existence of a specific interaction between embedded TEs and an RNA-binding protein, strengthening the model of TEs as functional modules in lncRNAs.-Fasolo, F., Patrucco, L., Volpe, M., Bon, C., Peano, C., Mignone, F., Carninci, P., Persichetti, F., Santoro, C., Zucchelli, S., Sblattero, D., Sanges, R., Cotella, D., Gustincich, S. The RNA-binding protein ILF3 binds to transposable element sequences in SINEUP lncRNAs.


Assuntos
Elementos de DNA Transponíveis , Proteínas do Fator Nuclear 90/metabolismo , RNA Antissenso/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Ubiquitina Tiolesterase/metabolismo , Animais , Biologia Computacional , Ensaios de Triagem em Larga Escala , Humanos , Camundongos , Proteínas do Fator Nuclear 90/genética , Biossíntese de Proteínas , Domínios e Motivos de Interação entre Proteínas , RNA Longo não Codificante/genética , RNA Mensageiro/genética , Ubiquitina Tiolesterase/genética
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