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1.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299197

RESUMO

In recent years, accumulating evidence has shown that the innate immune complement system is involved in several aspects of normal brain development and in neurodevelopmental disorders, including autism spectrum disorder (ASD). Although abnormal expression of complement components was observed in post-mortem brain samples from individuals with ASD, little is known about the expression patterns of complement molecules in distinct cell types in the developing autistic brain. In the present study, we characterized the mRNA and protein expression profiles of a wide range of complement system components, receptors and regulators in induced pluripotent stem cell (iPSC)-derived neural progenitor cells, neurons and astrocytes of individuals with ASD and neurotypical controls, which constitute in vitro cellular models that recapitulate certain features of both human brain development and ASD pathophysiology. We observed that all the analyzed cell lines constitutively express several key complement molecules. Interestingly, using different quantification strategies, we found that complement C4 mRNA and protein are expressed in significantly lower levels by astrocytes derived from ASD individuals compared to control astrocytes. As astrocytes participate in synapse elimination, and diminished C4 levels have been linked to defective synaptic pruning, our findings may contribute to an increased understanding of the atypically enhanced brain connectivity in ASD.


Assuntos
Astrócitos/patologia , Transtorno do Espectro Autista/patologia , Complemento C4/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Células-Tronco Neurais/patologia , Neurônios/patologia , Astrócitos/metabolismo , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Células Cultivadas , Complemento C4/genética , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Neurais/metabolismo , Plasticidade Neuronal/fisiologia , Neurônios/metabolismo
2.
Hum Mol Genet ; 26(12): 2177-2191, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28334780

RESUMO

Biallelic loss-of-function mutations in the RNA-binding protein EIF4A3 cause Richieri-Costa-Pereira syndrome (RCPS), an autosomal recessive condition mainly characterized by craniofacial and limb malformations. However, the pathogenic cellular mechanisms responsible for this syndrome are entirely unknown. Here, we used two complementary approaches, patient-derived induced pluripotent stem cells (iPSCs) and conditional Eif4a3 mouse models, to demonstrate that defective neural crest cell (NCC) development explains RCPS craniofacial abnormalities. RCPS iNCCs have decreased migratory capacity, a distinct phenotype relative to other craniofacial disorders. Eif4a3 haploinsufficient embryos presented altered mandibular process fusion and micrognathia, thus recapitulating the most penetrant phenotypes of the syndrome. These defects were evident in either ubiquitous or NCC-specific Eif4a3 haploinsufficient animals, demonstrating an autonomous requirement of Eif4a3 in NCCs. Notably, RCPS NCC-derived mesenchymal stem-like cells (nMSCs) showed premature bone differentiation, a phenotype paralleled by premature clavicle ossification in Eif4a3 haploinsufficient embryos. Likewise, nMSCs presented compromised in vitro chondrogenesis, and Meckel's cartilage was underdeveloped in vivo. These findings indicate novel and essential requirements of EIF4A3 for NCC migration and osteochondrogenic differentiation during craniofacial development. Altogether, complementary use of iPSCs and mouse models pinpoint unique cellular mechanisms by which EIF4A3 mutation causes RCPS, and provide a paradigm to study craniofacial disorders.


Assuntos
Pé Torto Equinovaro/genética , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , Deformidades Congênitas da Mão/genética , Síndrome de Pierre Robin/genética , Animais , Osso e Ossos/metabolismo , Região Branquial/metabolismo , Diferenciação Celular/genética , Movimento Celular , Condrogênese/genética , Pé Torto Equinovaro/metabolismo , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/metabolismo , Modelos Animais de Doenças , Deformidades Congênitas da Mão/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Camundongos , Crista Neural/crescimento & desenvolvimento , Crista Neural/metabolismo , Osteogênese/genética , Síndrome de Pierre Robin/metabolismo
3.
Hum Mutat ; 39(10): 1372-1383, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29969175

RESUMO

The Reelin-DAB1 signaling pathway plays a crucial role in regulating neuronal migration and synapse function. Although many rare heterozygous variants in the Reelin gene (RELN) have been identified in patients with autism spectrum disorder (ASD), most variants are still of unknown clinical significance. Also, genetic data suggest that heterozygous variants in RELN alone appear to be insufficient to cause ASD. Here, we describe the identification and functional characterization of rare compound heterozygous missense variants in RELN in a patient with ASD in whom we have previously reported hyperfunctional mTORC1 signaling of yet unknown etiology. Using iPSC-derived neural progenitor cells (NPCs) from this patient, we provide experimental evidence that the identified variants are deleterious and lead to diminished Reelin secretion and impaired Reelin-DAB1 signal transduction. Also, our results suggest that mTORC1 pathway overactivation may function as a second hit event contributing to downregulation of the Reelin-DAB1 cascade in patient-derived NPCs, and that inhibition of mTORC1 by rapamycin attenuates Reelin-DAB1 signaling impairment. Taken together, our findings point to an abnormal interplay between Reelin-DAB1 and mTORC1 networks in nonsyndromic ASD.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Variação Genética , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Transdução de Sinais , Proteínas Adaptadoras de Transdução de Sinal/química , Alelos , Transtorno do Espectro Autista/diagnóstico , Biomarcadores , Estudos de Casos e Controles , Moléculas de Adesão Celular Neuronais/química , Criança , Pré-Escolar , Proteínas da Matriz Extracelular/química , Feminino , Expressão Gênica , Heterozigoto , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Modelos Moleculares , Proteínas do Tecido Nervoso/química , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Conformação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína Reelina , Serina Endopeptidases/química , Relação Estrutura-Atividade , Serina-Treonina Quinases TOR/metabolismo
4.
Hum Mol Genet ; 24(24): 6877-85, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26385635

RESUMO

SPOAN syndrome is a neurodegenerative disorder mainly characterized by spastic paraplegia, optic atrophy and neuropathy (SPOAN). Affected patients are wheelchair bound after 15 years old, with progressive joint contractures and spine deformities. SPOAN patients also have sub normal vision secondary to apparently non-progressive congenital optic atrophy. A potential causative gene was mapped at 11q13 ten years ago. Here we performed next-generation sequencing in SPOAN-derived samples. While whole-exome sequencing failed to identify the causative mutation, whole-genome sequencing allowed to detect a homozygous 216-bp deletion (chr11.hg19:g.66,024,557_66,024,773del) located at the non-coding upstream region of the KLC2 gene. Expression assays performed with patient's fibroblasts and motor neurons derived from SPOAN patients showed KLC2 overexpression. Luciferase assay in constructs with 216-bp deletion confirmed the overexpression of gene reporter, varying from 48 to 74%, as compared with wild-type. Knockdown and overexpression of klc2 in Danio rerio revealed mild to severe curly-tail phenotype, which is suggestive of a neuromuscular disorder. Overexpression of a gene caused by a small deletion in the non-coding region is a novel mechanism, which to the best of our knowledge, was never reported before in a recessive condition. Although the molecular mechanism of KLC2 up-regulation still remains to be uncovered, such example adds to the importance of non-coding regions in human pathology.


Assuntos
Expressão Gênica , Proteínas Associadas aos Microtúbulos/genética , Atrofias Ópticas Hereditárias/genética , Deleção de Sequência , Paraplegia Espástica Hereditária/genética , Animais , Cromossomos Humanos Par 11 , Análise Mutacional de DNA , Neuropatia Hereditária Motora e Sensorial/genética , Humanos , Cinesinas , Síndrome , Peixe-Zebra , Proteínas de Peixe-Zebra/genética
6.
Adv Exp Med Biol ; 976: 137-148, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28508319

RESUMO

Transient receptor potential canonical (TRPC) channels mediate the influx of different types of cations through the cell membrane and are involved in many functions of the organism. Evidences of involvement of TRPC channels in neuronal development suggest that this family of proteins might play a role in certain neurological disorders. As reported, knockout mice for different TRPC channels show alterations in neuronal morphological and functional parameters, with behavioral abnormalities, such as in exploratory and social behaviors. Although mutations in TRPC channels could be related to mental/neurological disorders, there are only a few cases reported in literature, indicating that this correlation should be further explored. Nonetheless, other functional evidences support the implication of these channels in neurological diseases. In this chapter, we summarize the main findings relating TRPC channels to neurological disorders, such as autism spectrum disorders, bipolar disorder, and intellectual disability among others.


Assuntos
Encéfalo/metabolismo , Cálcio/metabolismo , Transtornos Mentais/metabolismo , Canais de Cátion TRPC/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Transtornos Mentais/genética , Camundongos , Camundongos Knockout , Canais de Cátion TRPC/genética
7.
Int J Mol Sci ; 18(3)2017 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-28335463

RESUMO

Whereas autism spectrum disorder (ASD) exhibits striking heterogeneity in genetics and clinical presentation, dysfunction of mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway has been identified as a molecular feature common to several well-characterized syndromes with high prevalence of ASD. Additionally, recent findings have also implicated mTORC1 signaling abnormalities in a subset of nonsyndromic ASD, suggesting that defective mTORC1 pathway may be a potential converging mechanism in ASD pathology across different etiologies. However, the mechanistic evidence for a causal link between aberrant mTORC1 pathway activity and ASD neurobehavioral features varies depending on the ASD form involved. In this review, we first discuss six monogenic ASD-related syndromes, including both classical and potentially novel mTORopathies, highlighting their contribution to our understanding of the neurobiological mechanisms underlying ASD, and then we discuss existing evidence suggesting that aberrant mTORC1 signaling may also play a role in nonsyndromic ASD.


Assuntos
Transtorno do Espectro Autista/genética , Complexos Multiproteicos/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Transtorno do Espectro Autista/metabolismo , Transtorno do Espectro Autista/patologia , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos/genética , Serina-Treonina Quinases TOR/genética
8.
Parkinsonism Relat Disord ; 116: 105847, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37844348

RESUMO

INTRODUCTION: Progressive Supranuclear Palsy (PSP) is a neurodegenerative tauopathy and, to date, the pathophysiological mechanisms in PSP that lead to Tau hyperphosphorylation and neurodegeneration are not clear. In some brain areas, Tau pathology in glial cells appears to precede Tau aggregation in neurons. The development of a model using astrocyte cell lines derived from patients has the potential to identify molecules and pathways that contribute to early events of neurodegeneration. We developed a model of induced pluripotent stem cells (iPSC)-derived astrocytes to investigate the pathophysiology of PSP, particularly early events that might contribute to Tau hyperphosphorylation, applying omics approach to detect differentially expressed genes, metabolites, and proteins, including those from the secretome. METHODS: Skin fibroblasts from PSP patients (without MAPT mutations) and controls were reprogrammed to iPSCs, further differentiated into neuroprogenitor cells (NPCs) and astrocytes. In the 5th passage, astrocytes were harvested for total RNA sequencing. Intracellular and secreted proteins were processed for proteomics experiments. Metabolomics profiling was obtained from supernatants only. RESULTS: We identified hundreds of differentially expressed genes. The main networks were related to cell cycle re-activation in PSP. Several proteins were found exclusively secreted by the PSP group. The cellular processes related to the cell cycle and mitotic proteins, TriC/CCT pathway, and redox signaling were enriched in the secretome of PSP. Moreover, we found distinct sets of metabolites between PSP and controls. CONCLUSION: Our iPSC-derived astrocyte model can provide distinct molecular signatures for PSP patients and it is useful to elucidate the initial stages of PSP pathogenesis.


Assuntos
Células-Tronco Pluripotentes Induzidas , Paralisia Supranuclear Progressiva , Tauopatias , Humanos , Paralisia Supranuclear Progressiva/diagnóstico , Astrócitos/metabolismo , Proteínas tau/genética , Tauopatias/patologia , Neurônios/metabolismo
9.
Am J Med Genet B Neuropsychiatr Genet ; 159B(5): 529-36, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22592906

RESUMO

Here, we describe a female patient with autism spectrum disorder and dysmorphic features that harbors a complex genetic alteration, involving a de novo balanced translocation t(2;X)(q11;q24), a 5q11 segmental trisomy and a maternally inherited isodisomy on chromosome 5. All the possibly damaging genetic effects of such alterations are discussed. In light of recent findings on ASD genetic causes, the hypothesis that all these alterations might be acting in orchestration and contributing to the phenotype is also considered.


Assuntos
Transtornos Globais do Desenvolvimento Infantil/genética , Aberrações Cromossômicas , Cromossomos Humanos/genética , Rearranjo Gênico/genética , Adulto , Criança , Cromossomos Humanos Par 2/genética , Cromossomos Humanos Par 5/genética , Cromossomos Humanos X/genética , Feminino , Estudos de Associação Genética , Humanos , Recém-Nascido , Masculino , Gravidez , Translocação Genética , Trissomia , Dissomia Uniparental/genética
10.
Front Oncol ; 12: 874168, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35756679

RESUMO

Acute myeloid leukemia (AML) is a hematologic malignancy associated with high morbidity and mortality. Here we describe a case of a patient with AML who presented a partial response after utilization of the non-steroidal anti-inflammatory drug nimesulide. The response was characterized by complete clearance of peripheral blood blasts and an 82% decrease of bone marrow blasts associated with myeloblast differentiation. We have then shown that nimesulide induces in vitro cell death and cell cycle arrest in all AML cell lines (HL-60, THP-1, OCI-AML2, and OCI-AML3). Weighted Correlation Network Analysis (WGCNA) of serial whole-transcriptome data of cell lines treated with nimesulide revealed that the sets of genes upregulated after treatment with nimesulide were enriched for genes associated with autophagy and apoptosis, and on the other hand, the sets of downregulated genes were associated with cell cycle and RNA splicing. Serial transcriptome of bone marrow patient sample confirmed the upregulation of genes associated with autophagy after the response to nimesulide. Lastly, we demonstrated that nimesulide potentiates the cytotoxic in vitro effect of several Food and Drug Administration (FDA)-approved chemotherapy drugs used in AML, including cytarabine.

11.
Front Neurosci ; 16: 828646, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35360153

RESUMO

Prenatal exposure to maternal immune activation (MIA) has been suggested to increase the probability of autism spectrum disorder (ASD). Recent evidence from animal studies indicates a key role for interleukin-17a (IL-17a) in promoting MIA-induced behavioral and brain abnormalities reminiscent of ASD. However, it is still unclear how IL-17a acts on the human developing brain and the cell types directly affected by IL-17a signaling. In this study, we used iPSC-derived neural progenitor cells (NPCs) from individuals with ASD of known and unknown genetic cause as well as from neurotypical controls to examine the effects of exogenous IL-17a on NPC proliferation, migration and neuronal differentiation, and whether IL-17a and genetic risk factors for ASD interact exacerbating alterations in NPC function. We observed that ASD and control NPCs endogenously express IL-17a receptor (IL17RA), and that IL-17a/IL17RA activation modulates downstream ERK1/2 and mTORC1 signaling pathways. Exogenous IL-17a did not induce abnormal proliferation and migration of ASD and control NPCs but, on the other hand, it significantly increased the expression of synaptic (Synaptophysin-1, Synapsin-1) and neuronal polarity (MAP2) proteins in these cells. Also, as we observed that ASD and control NPCs exhibited similar responses to exogenous IL-17a, it is possible that a more inflammatory environment containing other immune molecules besides IL-17a may be needed to trigger gene-environment interactions during neurodevelopment. In conclusion, our results suggest that exogenous IL-17a positively regulates the neuronal differentiation of human NPCs, which may disturb normal neuronal and synaptic development and contribute to MIA-related changes in brain function and behavior.

12.
Transl Psychiatry ; 12(1): 234, 2022 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-35668055

RESUMO

Oligogenic inheritance of autism spectrum disorder (ASD) has been supported by several studies. However, little is known about how the risk variants interact and converge on causative neurobiological pathways. We identified in an ASD proband deleterious compound heterozygous missense variants in the Reelin (RELN) gene, and a de novo splicing variant in the Cav3.2 calcium channel (CACNA1H) gene. Here, by using iPSC-derived neural progenitor cells (NPCs) and a heterologous expression system, we show that the variant in Cav3.2 leads to increased calcium influx into cells, which overactivates mTORC1 pathway and, consequently, further exacerbates the impairment of Reelin signaling. Also, we show that Cav3.2/mTORC1 overactivation induces proliferation of NPCs and that both mutant Cav3.2 and Reelin cause abnormal migration of these cells. Finally, analysis of the sequencing data from two ASD cohorts-a Brazilian cohort of 861 samples, 291 with ASD; the MSSNG cohort of 11,181 samples, 5,102 with ASD-revealed that the co-occurrence of risk variants in both alleles of Reelin pathway genes and in one allele of calcium channel genes confer significant liability for ASD. Our results support the notion that genes with co-occurring deleterious variants tend to have interconnected pathways underlying oligogenic forms of ASD.


Assuntos
Transtorno do Espectro Autista , Canais de Cálcio Tipo T , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Canais de Cálcio/genética , Canais de Cálcio Tipo T/genética , Predisposição Genética para Doença , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Herança Multifatorial
13.
Front Cell Neurosci ; 15: 803302, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35095425

RESUMO

Biallelic pathogenic variants in TBCK cause encephaloneuropathy, infantile hypotonia with psychomotor retardation, and characteristic facies 3 (IHPRF3). The molecular mechanisms underlying its neuronal phenotype are largely unexplored. In this study, we reported two sisters, who harbored biallelic variants in TBCK and met diagnostic criteria for IHPRF3. We provided evidence that TBCK may play an important role in the early secretory pathway in neuroprogenitor cells (iNPC) differentiated from induced pluripotent stem cells (iPSC). Lack of functional TBCK protein in iNPC is associated with impaired endoplasmic reticulum-to-Golgi vesicle transport and autophagosome biogenesis, as well as altered cell cycle progression and severe impairment in the capacity of migration. Alteration in these processes, which are crucial for neurogenesis, neuronal migration, and cytoarchitecture organization, may represent an important causative mechanism of both neurodevelopmental and neurodegenerative phenotypes observed in IHPRF3. Whether reduced mechanistic target of rapamycin (mTOR) signaling is secondary to impaired TBCK function over other secretory transport regulators still needs further investigation.

14.
Sci Rep ; 8(1): 11138, 2018 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-30042445

RESUMO

Several lines of indirect evidence, such as mutations or dysregulated expression of genes related to cytoskeleton, have suggested that cytoskeletal dynamics, a process essential for axons and dendrites development, is compromised in autism spectrum disorders (ASD). However, no study has yet examined whether cytoskeleton dynamics is functionally altered in cells from ASD patients. Here we investigated the regulation of actin cytoskeleton dynamics in stem cells from human exfoliated deciduous teeth (SHEDs) of 13 ASD patients and 8 control individuals by inducing actin filament depolymerization and then measuing their reconstruction upon activation of the RhoGTPases Rac, Cdc42 or RhoA. We observed that stem cells from seven ASD individuals (53%) presented altered dymanics of filament reconstruction, including a patient recently studied by our group whose iPSC-derived neuronal cells show shorten and less arborized neurites. We also report potentially pathogenic genetic variants that might be related to the alterations in actin repolymerization dynamics observed in some patient-derived cells. Our results suggest that, at least for a subgroup of ASD patients, the dynamics of actin polymerization is impaired, which might be ultimately leading to neuronal abnormalities.


Assuntos
Citoesqueleto de Actina/química , Actinas/química , Transtorno do Espectro Autista/genética , Neurônios/química , Citoesqueleto de Actina/genética , Actinas/genética , Animais , Transtorno do Espectro Autista/metabolismo , Transtorno do Espectro Autista/patologia , Regulação da Expressão Gênica/genética , Humanos , Células-Tronco Pluripotentes Induzidas/química , Células-Tronco Pluripotentes Induzidas/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Esfoliação de Dente , Proteína cdc42 de Ligação ao GTP/genética , Proteínas rac de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/genética
15.
Nat Commun ; 9(1): 1114, 2018 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-29535311

RESUMO

The original PDF version of this Article contained errors in the spelling of Luiz Carlos Caires-Júnior, Uirá Souto Melo, Bruno Henrique Silva Araujo, Alessandra Soares-Schanoski, Murilo Sena Amaral, Kayque Alves Telles-Silva, Vanessa van der Linden, Helio van der Linden, João Ricardo Mendes de Oliveira, Nivia Maria Rodrigues Arrais, Joanna Goes Castro Meira, Ana Jovina Barreto Bispo, Esper Abrão Cavalheiro, and Robert Andreata-Santos, which were incorrectly given as Luiz Carlos de Caires Jr., UiráSouto Melo, Bruno Silva Henrique Araujo, Alessandra Soares Schanoski, MuriloSena Amaral, Kayque Telles Alves Silva, Vanessa Van der Linden, Helio Van der Linden, João Mendes Ricardo de Oliveira, Nivia Rodrigues Maria Arrais, Joanna Castro Goes Meira, Ana JovinaBarreto Bispo, EsperAbrão Cavalheiro, and Robert Andreata Santos. Furthermore, in both the PDF and HTML versions of the Article, the top panel of Fig. 3e was incorrectly labeled '10608-1' and should have been '10608-4', and financial support from CAPES and DECIT-MS was inadvertently omitted from the Acknowledgements section. These errors have now been corrected in both the PDF and HTML versions of the Article.

16.
Nat Commun ; 9(1): 475, 2018 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-29396410

RESUMO

Congenital Zika syndrome (CZS) causes early brain development impairment by affecting neural progenitor cells (NPCs). Here, we analyze NPCs from three pairs of dizygotic twins discordant for CZS. We compare by RNA-Seq the NPCs derived from CZS-affected and CZS-unaffected twins. Prior to Zika virus (ZIKV) infection the NPCs from CZS babies show a significantly different gene expression signature of mTOR and Wnt pathway regulators, key to a neurodevelopmental program. Following ZIKV in vitro infection, cells from affected individuals have significantly higher ZIKV replication and reduced cell growth. Whole-exome analysis in 18 affected CZS babies as compared to 5 unaffected twins and 609 controls excludes a monogenic model to explain resistance or increased susceptibility to CZS development. Overall, our results indicate that CZS is not a stochastic event and depends on NPC intrinsic susceptibility, possibly related to oligogenic and/or epigenetic mechanisms.


Assuntos
Encéfalo/embriologia , Expressão Gênica , Células-Tronco Neurais/metabolismo , Gêmeos Dizigóticos , Infecção por Zika virus/congênito , Encéfalo/metabolismo , Encéfalo/virologia , Brasil , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Células-Tronco Pluripotentes Induzidas , Lactente , Recém-Nascido , Masculino , Células-Tronco Neurais/virologia , Análise de Sequência de RNA , Serina-Treonina Quinases TOR/genética , Via de Sinalização Wnt/genética , Infecção por Zika virus/genética , Infecção por Zika virus/virologia
17.
Einstein (Sao Paulo) ; 15(2): 233-238, 2017.
Artigo em Inglês, Português | MEDLINE | ID: mdl-28767925

RESUMO

Autism spectrum disorder is a complex and genetically heterogeneous disorder, which has hampered the identification of the etiological factors in each patient and, consequently, the genetic counseling for families at risk. However, in the last decades, the remarkable advances in the knowledge of genetic aspects of autism based on genetic and molecular research, as well as the development of new molecular diagnostic tools, have substantially changed this scenario. Nowadays, it is estimated that using the currently available molecular tests, a potential underlying genetic cause can be identified in nearly 25% of cases. Combined with clinical assessment, prenatal history evaluation and investigation of other physiological aspects, an etiological explanation for the disease can be found for approximately 30 to 40% of patients. Therefore, in view of the current knowledge about the genetic architecture of autism spectrum disorder, which has contributed for a more precise genetic counseling, and of the potential benefits that an etiological investigation can bring to patients and families, molecular genetic investigation has become increasingly important. Here, we discuss the current view of the genetic architecture of autism spectrum disorder, and list the main associated genetic alterations, the available molecular tests and the key aspects for the genetic counseling of these families. RESUMO O transtorno do espectro autista é um distúrbio complexo e geneticamente heterogêneo, o que sempre dificultou a identificação de sua etiologia em cada paciente em particular e, por consequência, o aconselhamento genético das famílias. Porém, nas últimas décadas, o acúmulo crescente de conhecimento oriundo das pesquisas sobre os aspectos genéticos e moleculares desta doença, assim como o desenvolvimento de novas ferramentas de diagnóstico molecular, tem mudado este cenário de forma substancial. Atualmente, estima-se que, por meio de testes moleculares, é possível detectar uma alteração genética potencialmente causal em cerca de 25% dos casos. Considerando-se também a avaliação clínica, a história pré-natal e a investigação de outros aspectos fisiológicos, pode-se atribuir uma etiologia para aproximadamente 30 a 40% dos pacientes. Assim, em vista do conhecimento atual sobre a arquitetura genética do transtorno do espectro autista, que tem tornado o aconselhamento genético cada vez mais preciso, e dos potenciais benefícios que a investigação etiológica pode trazer aos pacientes e familiares, tornam-se cada vez mais importantes os testes genéticos moleculares. Apresentamos aqui uma breve discussão sobre a visão atual da arquitetura genética dos transtornos do espectro autista, listando as principais alterações genéticas associadas, os testes moleculares disponíveis e os principais aspectos a se considerar para o aconselhamento genético destas famílias.


Assuntos
Transtorno do Espectro Autista/genética , Aconselhamento Genético/normas , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/etiologia , Saúde da Família/educação , Aconselhamento Genético/tendências , Humanos , Padrões de Herança/genética , Análise em Microsséries/normas , Guias de Prática Clínica como Assunto
18.
Eur J Hum Genet ; 24(1): 59-65, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25898924

RESUMO

Protein synthesis regulation via mammalian target of rapamycin complex 1 (mTORC1) signaling pathway has key roles in neural development and function, and its dysregulation is involved in neurodevelopmental disorders associated with autism and intellectual disability. mTOR regulates assembly of the translation initiation machinery by interacting with the eukaryotic initiation factor eIF3 complex and by controlling phosphorylation of key translational regulators. Collybistin (CB), a neuron-specific Rho-GEF responsible for X-linked intellectual disability with epilepsy, also interacts with eIF3, and its binding partner gephyrin associates with mTOR. Therefore, we hypothesized that CB also binds mTOR and affects mTORC1 signaling activity in neuronal cells. Here, by using induced pluripotent stem cell-derived neural progenitor cells from a male patient with a deletion of entire CB gene and from control individuals, as well as a heterologous expression system, we describe that CB physically interacts with mTOR and inhibits mTORC1 signaling pathway and protein synthesis. These findings suggest that disinhibited mTORC1 signaling may also contribute to the pathological process in patients with loss-of-function variants in CB.


Assuntos
Transtorno Autístico/genética , Fator de Iniciação 3 em Eucariotos/genética , Deleção de Genes , Deficiência Intelectual/genética , Complexos Multiproteicos/genética , Fatores de Troca de Nucleotídeo Guanina Rho/genética , Serina-Treonina Quinases TOR/genética , Adolescente , Transtorno Autístico/metabolismo , Transtorno Autístico/fisiopatologia , Estudos de Casos e Controles , Fator de Iniciação 3 em Eucariotos/metabolismo , Regulação da Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Células HEK293 , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Deficiência Intelectual/metabolismo , Deficiência Intelectual/fisiopatologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos/metabolismo , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Iniciação Traducional da Cadeia Peptídica , Cultura Primária de Células , Ligação Proteica , Fatores de Troca de Nucleotídeo Guanina Rho/deficiência , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Transfecção
19.
Stem Cells Int ; 2015: 249098, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25802529

RESUMO

Constraints for the application of MSCs for bone reconstruction include restricted self-renewal and limited cell amounts. iPSC technology presents advantages over MSCs, providing homogeneous cellular populations with prolonged self-renewal and higher plasticity. However, it is unknown if the osteogenic potential of iPSCs differs from that of MSCs and if it depends on the iPSCs originating cellular source. Here, we compared the in vitro osteogenesis between stem cells from human deciduous teeth (SHED) and MSC-like cells from iPSCs from SHED (iPS-SHED) and from human dermal fibroblasts (iPS-FIB). MSC-like cells from iPS-SHED and iPS-FIB displayed fibroblast-like morphology, downregulation of pluripotency markers and upregulation of mesenchymal markers. Comparative in vitro osteogenesis analysis showed higher osteogenic potential in MSC-like cells from iPS-SHED followed by MSC-like cells from iPS-FIB and SHED. CD105 expression, reported to be inversely correlated with osteogenic potential in MSCs, did not display this pattern, considering that SHED presented lower CD105 expression. Higher osteogenic potential of MSC-like cells from iPS-SHED may be due to cellular homogeneity and/or to donor tissue epigenetic memory. Our findings strengthen the rationale for the use of iPSCs in bone bioengineering. Unveiling the molecular basis behind these differences is important for a thorough use of iPSCs in clinical scenarios.

20.
PLoS One ; 9(9): e107705, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25255310

RESUMO

Copy number variations (CNVs) are an important cause of ASD and those located at 15q11-q13, 16p11.2 and 22q13 have been reported as the most frequent. These CNVs exhibit variable clinical expressivity and those at 15q11-q13 and 16p11.2 also show incomplete penetrance. In the present work, through multiplex ligation-dependent probe amplification (MLPA) analysis of 531 ethnically admixed ASD-affected Brazilian individuals, we found that the combined prevalence of the 15q11-q13, 16p11.2 and 22q13 CNVs is 2.1% (11/531). Parental origin could be determined in 8 of the affected individuals, and revealed that 4 of the CNVs represent de novo events. Based on CNV prediction analysis from genome-wide SNP arrays, the size of those CNVs ranged from 206 kb to 2.27 Mb and those at 15q11-q13 were limited to the 15q13.3 region. In addition, this analysis also revealed 6 additional CNVs in 5 out of 11 affected individuals. Finally, we observed that the combined prevalence of CNVs at 15q13.3 and 22q13 in ASD-affected individuals with epilepsy (6.4%) was higher than that in ASD-affected individuals without epilepsy (1.3%; p<0.014). Therefore, our data show that the prevalence of CNVs at 15q13.3, 16p11.2 and 22q13 in Brazilian ASD-affected individuals is comparable to that estimated for ASD-affected individuals of pure or predominant European ancestry. Also, it suggests that the likelihood of a greater number of positive MLPA results might be found for the 15q13.3 and 22q13 regions by prioritizing ASD-affected individuals with epilepsy.


Assuntos
Transtornos Globais do Desenvolvimento Infantil/complicações , Transtornos Globais do Desenvolvimento Infantil/genética , Cromossomos Humanos/genética , Variações do Número de Cópias de DNA , Epilepsia/complicações , Adolescente , Sequência de Bases , Brasil , Criança , Cromossomos Humanos Par 15/genética , Cromossomos Humanos Par 16/genética , Cromossomos Humanos Par 22/genética , Feminino , Genômica , Humanos , Masculino , Linhagem , Polimorfismo de Nucleotídeo Único
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