Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 63
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Mol Psychiatry ; 27(9): 3885-3897, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35715487

RESUMO

Methamphetamine (METH) is a widely abused psychostimulant, whose hyper-rewarding property is believed to underlie its addictive effect, but the molecular mechanism regulating this effect remains unclear. We previously reported that decreased expression of a novel microRNA (miRNA), novel-m009C, is implicated in the regulation of METH hyperlocomotion. Here, we found that novel-m009C may be homologous to hsa-miR-604. Its expression is consistently downregulated in the nucleus accumbens (NAc) of mice when exposed to METH and cocaine, whereas significant alterations in novel-m009C expression were not observed in the NAc of mice subjected to other rewarding and psychiatric stimuli, such as sucrose, morphine and MK-801. We further found the substantial reduction in novel-m009C expression may be regulated by both dopamine receptor D1 (D1R) and D2 (D2R). Increasing novel-m009C levels in the NAc attenuated METH-induced conditioned place preference (CPP) and hyperlocomotion, whereas inhibiting novel-m009C expression in the NAc enhanced these effects but did not change the preference of mice for a natural reward, i.e., sucrose. These effects may involve targeting of genes important for the synaptic transmission, such as Grin1 (NMDAR subunit 1). Our findings demonstrate an important role for NAc novel-m009C in regulating METH reward, reveal a novel molecular regulator of the actions of METH on brain reward circuitries and provide a new strategy for treating METH addiction based on the modulation of small non-coding RNAs.


Assuntos
Estimulantes do Sistema Nervoso Central , Metanfetamina , MicroRNAs , Animais , Camundongos , Estimulantes do Sistema Nervoso Central/farmacologia , Metanfetamina/farmacologia , MicroRNAs/genética , MicroRNAs/metabolismo , Núcleo Accumbens/metabolismo , Recompensa , Sacarose/farmacologia
2.
Hum Mol Genet ; 28(7): 1100-1116, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30496485

RESUMO

Coiled-coil-helix-coiled-coil-helix domain containing protein 2 (CHCHD2) mutations were linked with autosomal dominant Parkinson's disease (PD) and recently, Alzheimer's disease/frontotemporal dementia. In the current study, we generated isogenic human embryonic stem cell (hESC) lines harboring PD-associated CHCHD2 mutation R145Q or Q126X via clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) method, aiming to unravel pathophysiologic mechanism and seek potential intervention strategy against CHCHD2 mutant-caused defects. By engaging super-resolution microscopy, we identified a physical proximity and similar distribution pattern of CHCHD2 along mitochondria with mitochondrial contact site and cristae organizing system (MICOS), a large protein complex maintaining mitochondria cristae. Isogenic hESCs and differentiated neural progenitor cells (NPCs) harboring CHCHD2 R145Q or Q126X mutation showed impaired mitochondria function, reduced CHCHD2 and MICOS components and exhibited nearly hollow mitochondria with reduced cristae. Furthermore, PD-linked CHCHD2 mutations lost their interaction with coiled-coil-helix-coiled-coil-helix domain containing protein 10 (CHCHD10), while transient knockdown of either CHCHD2 or CHCHD10 reduced MICOS and mitochondria cristae. Importantly, a specific mitochondria-targeted peptide, Elamipretide/MTP-131, now tested in phase 3 clinical trials for mitochondrial diseases, was found to enhance CHCHD2 with MICOS and mitochondria oxidative phosphorylation enzymes in isogenic NPCs harboring heterozygous R145Q, suggesting that Elamipretide is able to attenuate CHCHD2 R145Q-induced mitochondria dysfunction. Taken together, our results suggested CHCHD2-CHCHD10 complex may be a novel therapeutic target for PD and related neurodegenerative disorders, and Elamipretide may benefit CHCHD2 mutation-linked PD.


Assuntos
Doenças Mitocondriais/genética , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/fisiologia , Fatores de Transcrição/genética , Animais , Linhagem Celular , Proteínas de Ligação a DNA , Demência Frontotemporal/metabolismo , Estudos de Associação Genética/métodos , Células-Tronco Embrionárias Humanas/metabolismo , Células-Tronco Embrionárias Humanas/fisiologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Doenças Mitocondriais/metabolismo , Membranas Mitocondriais/metabolismo , Proteínas Mitocondriais/metabolismo , Mutação/genética , Doenças Neurodegenerativas/metabolismo , Oligopeptídeos/farmacologia , Doença de Parkinson/genética , Doença de Parkinson/fisiopatologia , Fatores de Transcrição/fisiologia
3.
Addict Biol ; 26(1): e12881, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32058631

RESUMO

Methamphetamine (METH) -induced behavioral sensitization depends on long-term neuroplasticity in the mesolimbic dopamine system, especially in the nucleus accumbens (NAc). miR-128, a brain enriched miRNA, was found to have abilities in regulating neuronal excitability and formation of fear-extinction memory. Here, we aim to identify the role of miR-128 on METH-induced locomotor sensitization of male mice. We identified a significant increase of miR-128 in the NAc of mice upon repeated-intermittent METH exposure but not acute METH administration. Microinjection of adeno-associated virus (AAV)-miR-128 over-expression and inhibition constructs into the NAc of mice resulted in enhanced METH-induced locomotor sensitization and attenuated effects of METH respectively. Isobaric tags for relative and absolute quantification (iTRAQ) technology and ingenuity pathway analysis (IPA) were carried out to uncover the potential molecular mechanisms underlying miR-128-regulated METH sensitization. Differentially expressed proteins, including 25 potential targets for miR-128 were annotated in regulatory pathways that modulate dendritic spines, synaptic transmission and neuritogenesis. Of which, Arf6, Cpeb3 and Nlgn1, were found to be participating in miR-128-regulated METH sensitization. Consistently, METH-induced abnormal changes of Arf6, Cpeb3 and Nlgn1 in the NAc of mice were also detected by qPCR and validated by western blot analysis. Thus, miR-128 may contribute to METH sensitization through controlling neuroplasticity. Our study suggested miR-128 was an important regulator of METH- induced sensitization and also provided the potential molecular networks of miR-128 in regulating METH-induced sensitization.


Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Metanfetamina/farmacologia , MicroRNAs/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , Núcleo Accumbens/efeitos dos fármacos , Animais , Aprendizagem/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos
4.
Nature ; 509(7501): 503-6, 2014 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-24828044

RESUMO

Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is essential for normal brain growth and cognitive function. Consistent with its importance in the brain, DHA is highly enriched in brain phospholipids. Despite being an abundant fatty acid in brain phospholipids, DHA cannot be de novo synthesized in brain and must be imported across the blood-brain barrier, but mechanisms for DHA uptake in brain have remained enigmatic. Here we identify a member of the major facilitator superfamily--Mfsd2a (previously an orphan transporter)--as the major transporter for DHA uptake into brain. Mfsd2a is found to be expressed exclusively in endothelium of the blood-brain barrier of micro-vessels. Lipidomic analysis indicates that Mfsd2a-deficient (Mfsd2a-knockout) mice show markedly reduced levels of DHA in brain accompanied by neuronal cell loss in hippocampus and cerebellum, as well as cognitive deficits and severe anxiety, and microcephaly. Unexpectedly, cell-based studies indicate that Mfsd2a transports DHA in the form of lysophosphatidylcholine (LPC), but not unesterified fatty acid, in a sodium-dependent manner. Notably, Mfsd2a transports common plasma LPCs carrying long-chain fatty acids such LPC oleate and LPC palmitate, but not LPCs with less than a 14-carbon acyl chain. Moreover, we determine that the phosphor-zwitterionic headgroup of LPC is critical for transport. Importantly, Mfsd2a-knockout mice have markedly reduced uptake of labelled LPC DHA, and other LPCs, from plasma into brain, demonstrating that Mfsd2a is required for brain uptake of DHA. Our findings reveal an unexpected essential physiological role of plasma-derived LPCs in brain growth and function.


Assuntos
Encéfalo/metabolismo , Ácidos Docosa-Hexaenoicos/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Animais , Ansiedade/fisiopatologia , Transporte Biológico , Barreira Hematoencefálica/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Transtornos Cognitivos/patologia , Transtornos Cognitivos/fisiopatologia , Ácidos Docosa-Hexaenoicos/deficiência , Endotélio Vascular/metabolismo , Feminino , Lisofosfatidilcolinas/química , Lisofosfatidilcolinas/metabolismo , Masculino , Proteínas de Membrana Transportadoras/deficiência , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Knockout , Microcefalia/metabolismo , Microcefalia/patologia , Microvasos/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Tamanho do Órgão , Sódio/metabolismo , Simportadores
5.
Cereb Cortex ; 28(4): 1516-1531, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29420702

RESUMO

Radial migration of cortical projection neurons is a prerequisite for shaping a distinct multilayered cerebral cortex during mammalian corticogenesis. Members of Rab GTPases family were reported to regulate radial migration. Here, in vivo conditional knockout or in utero knockdown (KD) of Rab23 in mice neocortex causes aberrant polarity and halted migration of cortical projection neurons. Further investigation of the underlying mechanism reveals down-regulation of N-cadherin in the Rab23-deficient neurons, which is a cell adhesion protein previously known to modulate radial migration. (Shikanai M, Nakajima K, Kawauchi T. 2011. N-cadherin regulates radial glial fiber-dependent migration of cortical locomoting neurons. Commun Integr Biol. 4:326-330.) Interestingly, pharmacological inhibition of extracellular signal-regulated kinases (ERK1/2) also decreases the expression of N-cadherin, implicating an upstream effect of ERK1/2 on N-cadherin and also suggesting a link between Rab23 and ERK1/2. Further biochemical studies show that silencing of Rab23 impedes activation of ERK1/2 via perturbed platelet-derived growth factor-alpha (PDGFRα) signaling. Restoration of the expression of Rab23 or N-cadherin in Rab23-KD neurons could reverse neuron migration defects, indicating that Rab23 modulates migration through N-cadherin. These studies suggest that cortical neuron migration is mediated by a molecular hierarchy downstream of Rab23 via N-cadherin.


Assuntos
Caderinas/metabolismo , Movimento Celular/genética , Córtex Cerebral/citologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Neurônios/fisiologia , Proteínas rab de Ligação ao GTP/metabolismo , Fatores Etários , Animais , Animais Recém-Nascidos , Caderinas/genética , Córtex Cerebral/embriologia , Córtex Cerebral/crescimento & desenvolvimento , Embrião de Mamíferos , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Homeodomínio/metabolismo , Camundongos , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/metabolismo , Nestina/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais/genética , Fatores de Tempo , Fatores de Transcrição/metabolismo , Proteínas rab de Ligação ao GTP/genética
6.
Addict Biol ; 24(3): 498-508, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-29516602

RESUMO

microRNA (miRNA) play important roles in drug addiction and act as a post-transcriptional regulator of gene expression. We previously reported extensive downregulation of miRNAs in the nucleus accumbens (NAc) of methamphetamine (METH)-sensitized mice. However, the regulatory mechanism of this METH-induced downregulation of miRNAs has yet to be elucidated. Thus, we examined METH-induced changes in the expression of miRNAs and their precursors, as well as the expression levels of mRNA and the proteins involved in miRNA biogenesis such as Dicer1 and Ago2, in the nucleus accumbens of METH-induced locomotor sensitized mice. miRNAs and Ago2 were significantly downregulated, while the expression of miRNA precursors remained unchanged or upregulated, which suggests that the downregulation of miRNAs was likely due to a reduction in Ago2-mediated splicing but unlikely to be regulated at the transcription level. Interestingly, the expression level of Dicer1, which is a potential target of METH-induced decreased miRNAs, such as miR-124, miR-212 and miR-29b, was significantly increased. In conclusion, this study indicates that miRNA biogenesis (such as Ago2 and Dicer1) and their miRNA products may have a role in the development of METH addiction.


Assuntos
Proteínas Argonautas/fisiologia , Estimulantes do Sistema Nervoso Central/farmacologia , RNA Helicases DEAD-box/fisiologia , Locomoção/efeitos dos fármacos , Metanfetamina/farmacologia , MicroRNAs/metabolismo , Ribonuclease III/fisiologia , Transtornos Relacionados ao Uso de Anfetaminas/fisiopatologia , Animais , Regulação para Baixo/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Núcleo Accumbens/efeitos dos fármacos
7.
J Biol Chem ; 291(48): 25088-25095, 2016 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-27687730

RESUMO

Proper positioning of neurons is fundamental for brain functions. However, little is known on how adult-born neurons generated in the hilar side of hippocampal dentate gyrus migrate into the granular cell layer. Because class 3 Semaphorins (Sema3) are involved in dendritic growth of these newborn neurons, we examined whether they are essential for cell positioning. We disrupted Sema3 signaling by silencing neuropilin 1 (NRP1) or 2 (NRP2), the main receptors for Sema3A and Sema3F, in neural progenitors of adult mouse dentate gyrus. Silencing of NRP2, but not NRP1, affected cell positioning of adult newborn neurons. Glycogen synthase kinase-3ß (GSK3ß) knockdown phenocopied this NRP2 silencing-mediated cell positioning defect, but did not affect dendritic growth. Furthermore, GSK3ß is activated upon stimulation with Sema3F, and GSK3ß overexpression rescued the cell positioning phenotypes seen in NRP2-deficient neurons. These results point to a new role for NRP2 in the positioning of neurons during adult hippocampal neurogenesis, acting via the GSK3ß signaling pathway.


Assuntos
Giro Denteado/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Neuropilina-2/metabolismo , Transdução de Sinais/fisiologia , Animais , Giro Denteado/citologia , Feminino , Glicogênio Sintase Quinase 3 beta/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurônios/citologia , Semaforina-3A/genética , Semaforina-3A/metabolismo
8.
Stem Cells ; 34(10): 2471-2484, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27299710

RESUMO

In most human somatic cells, the lack of telomerase activity results in progressive telomere shortening during each cell division. Eventually, DNA damage responses triggered by critically short telomeres induce an irreversible cell cycle arrest termed replicative senescence. However, the cellular responses of human pluripotent stem cells to telomere uncapping remain unknown. We generated telomerase knockout human embryonic stem (ES) cells through gene targeting. Telomerase inactivation in ES cells results in progressive telomere shortening. Telomere DNA damage in ES cells and neural progenitor cells induces rapid apoptosis when telomeres are uncapped, in contrast to fibroblast cells that enter a state of replicative senescence. Significantly, telomerase inactivation limits the proliferation capacity of human ES cells without affecting their pluripotency. By targeting telomerase activity, we can functionally separate the two unique properties of human pluripotent stem cells, namely unlimited self-renewal and pluripotency. We show that the potential of ES cells to form teratomas in vivo is dictated by their telomere length. By controlling telomere length of ES cells through telomerase inactivation, we can inhibit teratoma formation and potentially improve the safety of cell therapies involving terminally differentiated cells as well as specific progenitor cells that do not require sustained cellular proliferation in vivo, and thus sustained telomerase activity. Stem Cells 2016;34:2471-2484.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/efeitos adversos , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Embrionárias Humanas/metabolismo , Telômero/metabolismo , Animais , Biomarcadores/metabolismo , Morte Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Etoposídeo/farmacologia , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Engenharia Genética , Genoma Humano , Células-Tronco Embrionárias Humanas/efeitos dos fármacos , Células-Tronco Embrionárias Humanas/transplante , Humanos , Camundongos SCID , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Transplante de Células-Tronco , Telomerase/metabolismo , Encurtamento do Telômero/efeitos dos fármacos , Teratoma/genética , Teratoma/patologia
9.
Stem Cells Transl Med ; 12(8): 510-526, 2023 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-37487111

RESUMO

Neurodegenerative diseases (ND) are an entire spectrum of clinical conditions that affect the central and peripheral nervous system. There is no cure currently, with treatment focusing mainly on slowing down progression or symptomatic relief. Cellular therapies with various cell types from different sources are being conducted as clinical trials for several ND diseases. They include neural, mesenchymal and hemopoietic stem cells, and neural cells derived from embryonic stem cells and induced pluripotent stem cells. In this review, we present the list of cellular therapies for ND comprising 33 trials that used neural stem progenitors, 8 that used differentiated neural cells ,and 109 trials that involved non-neural cells in the 7 ND. Encouraging results have been shown in a few early-phase clinical trials that require further investigations in a randomized setting. However, such definitive trials may not be possible given the relative cost of the trials, and in the setting of rare diseases.


Assuntos
Doenças Neurodegenerativas , Células-Tronco Pluripotentes , Humanos , Doenças Neurodegenerativas/terapia , Transplante de Células-Tronco/métodos , Neurônios/fisiologia , Células-Tronco Embrionárias , Células-Tronco Pluripotentes/fisiologia
10.
Cells ; 12(6)2023 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-36980275

RESUMO

Biophysical parameters such as substrate topography and stiffness have been shown independently to elicit profound effects on neuronal differentiation and maturation from neural progenitor cells (NPCs) yet have not been investigated in combination. Here, the effects of various micrograting and stiffness combinations on neuronal differentiation and maturation were investigated using a polyacrylamide and N-acryloyl-6-aminocaproic acid copolymer (PAA-ACA) hydrogel with tunable stiffness. Whole laminin was conjugated onto the PAA-ACA surface indirectly or directly to facilitate long-term mouse and human NPC-derived neuron attachment. Three micrograting dimensions (2-10 µm) were patterned onto gels with varying stiffness (6.1-110.5 kPa) to evaluate the effects of topography, stiffness, and their interaction. The results demonstrate that the extracellular matrix (ECM)-modified PAA-ACA gels support mouse and human neuronal cell attachment throughout the differentiation and maturation stages (14 and 28 days, respectively). The interaction between topography and stiffness is shown to significantly increase the proportion of ß-tubulin III (TUJ1) positive neurons and microtubule associated protein-2 (MAP2) positive neurite branching and length. Thus, the effects of topography and stiffness cannot be imparted. These results provide a novel platform for neural mechanobiology studies and emphasize the utility of optimizing numerous biophysical cues for improved neuronal yield in vitro.


Assuntos
Hidrogéis , Células-Tronco Neurais , Camundongos , Animais , Humanos , Hidrogéis/farmacologia , Neurônios , Matriz Extracelular , Diferenciação Celular
11.
Comput Biol Med ; 165: 107416, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37660568

RESUMO

In recent years, supervised machine learning models trained on videos of animals with pose estimation data and behavior labels have been used for automated behavior classification. Applications include, for example, automated detection of neurological diseases in animal models. However, we identify two potential problems of such supervised learning approach. First, such models require a large amount of labeled data but the labeling of behaviors frame by frame is a laborious manual process that is not easily scalable. Second, such methods rely on handcrafted features obtained from pose estimation data that are usually designed empirically. In this paper, we propose to overcome these two problems using contrastive learning for self-supervised feature engineering on pose estimation data. Our approach allows the use of unlabeled videos to learn feature representations and reduce the need for handcrafting of higher-level features from pose positions. We show that this approach to feature representation can achieve better classification performance compared to handcrafted features alone, and that the performance improvement is due to contrastive learning on unlabeled data rather than the neural network architecture. The method has the potential to reduce the bottleneck of scarce labeled videos for training and improve performance of supervised behavioral classification models for the study of interaction behaviors in animals.


Assuntos
Trabalho de Parto , Animais , Gravidez , Feminino , Redes Neurais de Computação , Aprendizado de Máquina Supervisionado
12.
Biology (Basel) ; 12(5)2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37237509

RESUMO

Breast cancer is now the most common cancer worldwide, and it is also the main cause of cancer-related death in women. Survival rates for female breast cancer have significantly improved due to early diagnosis and better treatment. Nevertheless, for patients with advanced or metastatic breast cancer, the survival rate is still low, reflecting a need for the development of new therapies. Mechanistic insights into metastatic breast cancer have provided excellent opportunities for developing novel therapeutic strategies. Although high-throughput approaches have identified several therapeutic targets in metastatic disease, some subtypes such as triple-negative breast cancer do not yet have an apparent tumor-specific receptor or pathway to target. Therefore, exploring new druggable targets in metastatic disease is a high clinical priority. In this review, we summarize the emerging intrinsic therapeutic targets for metastatic breast cancer, including cyclin D-dependent kinases CDK4 and CDK6, the PI3K/AKT/mTOR pathway, the insulin/IGF1R pathway, the EGFR/HER family, the JAK/STAT pathway, poly(ADP-ribose) polymerases (PARP), TROP-2, Src kinases, histone modification enzymes, activated growth factor receptors, androgen receptors, breast cancer stem cells, matrix metalloproteinases, and immune checkpoint proteins. We also review the latest development in breast cancer immunotherapy. Drugs that target these molecules/pathways are either already FDA-approved or currently being tested in clinical trials.

13.
Small ; 8(19): 3050-61, 2012 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-22807278

RESUMO

During development and tissue repair, progenitor cells are guided by both biochemical and biophysical cues of their microenvironment, including topographical signals. The topographical cues have been shown to play an important role in controlling the fate of cells. Systematic investigation of topographical structures with different geometries and sizes under the identical experimental conditions on the same chip will enhance the understanding of the role of shape and size in cell-topography interactions. A simple customizable multi-architecture chip (MARC) array is therefore developed to incorporate, on a single chip, distinct topographies of various architectural complexities, including both isotropic and anisotropic features, in nano- to micrometer dimensions, with different aspect ratios and hierarchical structures. Polydimethylsiloxane (PDMS) replicas of MARC are used to investigate the influence of different geometries and sizes in neural differentiation of primary murine neural progenitor cells (mNPCs). Anisotropic gratings (2 µm gratings, 250 nm gratings) and isotropic 1 µm pillars significantly promote differentiation of mNPCs into neurons, as indicated by expression of ß-III-tubulin (59%, 58%, and 58%, respectively, compared to 30% on the control). In contrast, glial differentiation is enhanced on isotropic 2 µm holes and 1 µm pillars. These results illustrate that anisotropic topographies enhance neuronal differentiation while isotropic topographies enhance glial differentiation on the same chip under the same conditions. MARC enables simultaneous cost-effective investigation of multiple topographies, allowing efficient optimization of topographical and biochemical cues to modulate cell differentiation.


Assuntos
Diferenciação Celular , Dispositivos Lab-On-A-Chip , Neurônios/citologia , Células-Tronco/citologia , Animais , Células Cultivadas , Dimetilpolisiloxanos/química , Camundongos , Procedimentos Analíticos em Microchip/métodos , Microscopia Eletrônica de Varredura , Neurônios/metabolismo , Células-Tronco/metabolismo , Propriedades de Superfície
14.
Nature ; 439(7076): 589-93, 2006 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-16341203

RESUMO

Adult neurogenesis, the birth and integration of new neurons from adult neural stem cells, is a striking form of structural plasticity and highlights the regenerative capacity of the adult mammalian brain. Accumulating evidence suggests that neuronal activity regulates adult neurogenesis and that new neurons contribute to specific brain functions. The mechanism that regulates the integration of newly generated neurons into the pre-existing functional circuitry in the adult brain is unknown. Here we show that newborn granule cells in the dentate gyrus of the adult hippocampus are tonically activated by ambient GABA (gamma-aminobutyric acid) before being sequentially innervated by GABA- and glutamate-mediated synaptic inputs. GABA, the major inhibitory neurotransmitter in the adult brain, initially exerts an excitatory action on newborn neurons owing to their high cytoplasmic chloride ion content. Conversion of GABA-induced depolarization (excitation) into hyperpolarization (inhibition) in newborn neurons leads to marked defects in their synapse formation and dendritic development in vivo. Our study identifies an essential role for GABA in the synaptic integration of newly generated neurons in the adult brain, and suggests an unexpected mechanism for activity-dependent regulation of adult neurogenesis, in which newborn neurons may sense neuronal network activity through tonic and phasic GABA activation.


Assuntos
Envelhecimento/fisiologia , Encéfalo/citologia , Encéfalo/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Sinapses/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Dendritos/metabolismo , Giro Denteado/citologia , Giro Denteado/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL
15.
Front Pharmacol ; 13: 940798, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35928279

RESUMO

The deleterious effects of methamphetamine (METH) exposure extend beyond abusers, and may potentially impact the vulnerability of their offspring in developing addictive behaviors. Epigenetic signatures have been implicated in addiction, yet the characteristics to identify prenatal METH abuse to offspring addiction risk remains elusive. Here, we used escalating doses of METH-exposed mouse model in F0 female mice before and during pregnancy to simulate the human pattern of drug abuse and generated METH-induced behavioral sensitization to investigate the addictive behavior in offspring mice. We then utilized whole genome-bisulfite sequencing (WGBS) to investigate the methylation signature of nucleus accumbens (NAc) in male METH-sensitized mice. Interestingly, male but not female offspring exhibited an enhanced response to METH-induced behavioral sensitization. Additionally, the METH-exposed group of male mice underwent a more comprehensive wave of epigenome remodeling over all genomic elements compared with unexposed groups due to drug exposure history. 104,219 DMCs (METH-SAL vs. SAL-SAL) induced by prenatal METH-exposure were positively correlated with that of postnatal METH-exposure (38,570, SAL-METH vs. SAL-SAL). Moreover, 4,983 DMCs induced by pre- and postnatal METH exposure (METH-METH vs. SAL-METH) were negatively correlated with that of postnatal METH exposure, and 371 commonly changed DMCs between the two comparison groups also showed a significantly negative correlation and 86 annotated genes functionally enriched in the pathways of neurodevelopment and addiction. Key annotated genes included Kirrel3, Lrpprc, and Peg3, implicated in neurodevelopmental processes, were down-regulated in METH-METH group mice compared with the SAL-METH group. Taken together, we render novel insights into the epigenetic correlation of drug exposure and provide evidence for epigenetic characteristics that link maternal METH exposure to the intensity of the same drug-induced behavioral sensitization in adult offspring.

16.
Front Digit Health ; 4: 875895, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35899035

RESUMO

The definitive diagnosis of Alzheimer's Disease (AD) without the need for neuropathological confirmation remains a challenge in AD research today, despite efforts to uncover the molecular and biological underpinnings of the disease process. Furthermore, the potential for therapeutic intervention is limited upon the onset of symptoms, providing motivation for studying and treating the AD precursor mild cognitive impairment (MCI), the prodromal stage of AD instead. Applying machine learning classification to transcriptomic data of MCI, AD, and cognitively normal (CN) control patients, we identified differentially expressed genes that serve as biomarkers for the characterization and classification of subjects into MCI or AD groups. Predictive models employing these biomarker genes exhibited good classification performances for CN, MCI, and AD, significantly above random chance. The PI3K-Akt, IL-17, JAK-STAT, TNF, and Ras signaling pathways were also enriched in these biomarker genes, indicating their diagnostic potential and pathophysiological roles in MCI and AD. These findings could aid in the recognition of MCI and AD risk in clinical settings, allow for the tracking of disease progression over time in individuals as part of a therapeutic approach, and provide possible personalized drug targets for early intervention of MCI and AD.

17.
Front Pharmacol ; 12: 708034, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34483916

RESUMO

Dysregulation of microRNA (miRNA) biogenesis is involved in drug addiction. Argonaute2 (Ago2), a specific splicing protein involved in the generation of miRNA, was found to be dysregulated in the nucleus accumbens (NAc) of methamphetamine (METH)-sensitized mice in our previous study. Here, we determined whether Ago2 in the NAc regulates METH sensitization in mice and identified Ago2-dependent miRNAs involved in this process. We found a gradual reduction in Ago2 expression in the NAc following repeated METH use. METH-induced hyperlocomotor activity in mice was strengthened by knocking down NAc neuronal levels of Ago2 but reduced by overexpressing Ago2 in NAc neurons. Surprisingly, miR-3068-5p was upregulated following overexpression of Ago2 and downregulated by silencing Ago2 in the NAc. Knocking down miR-3068-5p, serving as an Ago2-dependent miRNA, strengthened the METH sensitization responses in mice. These findings demonstrated that dysregulated Ago2 in neurons in the NAc is capable of regulating METH sensitization and suggested a potential role of Ago2-dependent miR-3068-5p in METH sensitization.

18.
Front Mol Neurosci ; 14: 762142, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858138

RESUMO

The activation of chloride (Cl-)permeable gamma (γ)-aminobutyric acid type A(GABAA) receptors induces synaptic inhibition in mature and excitation in immature neurons. This developmental "switch" in GABA function controlled by its polarity depends on the postnatal decrease in intraneuronal Cl- concentration mediated by KCC2, a member of cation-chloride cotransporters (CCCs). The serine-threonine kinase WNK3 (With No Lysine [K]), is a potent regulator of all CCCs and is expressed in neurons. Here, we characterized the functions of WNK3 and its role in GABAergic signaling in cultured embryonic day 18 (E18) hippocampal neurons. We observed a decrease in WNK3 expression as neurons mature. Knocking down of WNK3 significantly hyperpolarized EGABA in mature neurons (DIV13-15) but had no effect on immature neurons (DIV6-8). This hyperpolarized EGABA in WNK3-deficient neurons was not due to the total expression of NKCC1 and KCC2, that remained unchanged. However, there was a reduction in phosphorylated KCC2 at the membrane, suggesting an increase in KCC2 chloride export activity. Furthermore, hyperpolarized EGABA observed in WNK3-deficient neurons can be reversed by the KCC2 inhibitor, VU024055, thus indicating that WNK3 acts through KCC2 to influence EGABA . Notably, WNK3 knockdown resulted in morphological changes in mature but not immature neurons. Electrophysiological characterization of WNK3-deficient mature neurons revealed reduced capacitances but increased intrinsic excitability and synaptic excitation. Hence, our study demonstrates that WNK3 maintains the "adult" GABAergic inhibitory tone in neurons and plays a role in the morphological development of neurons and excitability.

19.
Neural Regen Res ; 15(4): 573-585, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31638079

RESUMO

Extracellular matrix (ECM) influences cell differentiation through its structural and biochemical properties. In nervous system, neuronal behavior is influenced by these ECMs structures which are present in a meshwork, fibrous, or tubular forms encompassing specific molecular compositions. In addition to contact guidance, ECM composition and structures also exert its effect on neuronal differentiation. This short report reviewed the native ECM structure and composition in central nervous system and peripheral nervous system, and their impact on neural regeneration and neuronal differentiation. Using topographies, stem cells have been differentiated to neurons. Further, focussing on engineered biomimicking topographies, we highlighted the role of anisotropic topographies in stem cell differentiation to neurons and its recent temporal application for efficient neuronal differentiation.

20.
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA