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1.
Mol Cell ; 83(2): 186-202.e11, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36669479

RESUMO

PGC-1α is well established as a metazoan transcriptional coactivator of cellular adaptation in response to stress. However, the mechanisms by which PGC-1α activates gene transcription are incompletely understood. Here, we report that PGC-1α serves as a scaffold protein that physically and functionally connects the DNA-binding protein estrogen-related receptor α (ERRα), cap-binding protein 80 (CBP80), and Mediator to overcome promoter-proximal pausing of RNAPII and transcriptionally activate stress-response genes. We show that PGC-1α promotes pausing release in a two-arm mechanism (1) by recruiting the positive transcription elongation factor b (P-TEFb) and (2) by outcompeting the premature transcription termination complex Integrator. Using mice homozygous for five amino acid changes in the CBP80-binding motif (CBM) of PGC-1α that destroy CBM function, we show that efficient differentiation of primary myoblasts to myofibers and timely skeletal muscle regeneration after injury require PGC-1α binding to CBP80. Our findings reveal how PGC-1α activates stress-response gene transcription in a previously unanticipated pre-mRNA quality-control pathway.


Assuntos
Precursores de RNA , Fatores de Transcrição , Animais , Camundongos , Proteínas de Ligação a DNA/genética , Músculo Esquelético/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Regiões Promotoras Genéticas , Proteínas de Ligação ao Cap de RNA/genética , RNA Polimerase II/metabolismo , Precursores de RNA/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica
2.
Nature ; 628(8007): 408-415, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38480883

RESUMO

During development, inflammation or tissue injury, macrophages may successively engulf and process multiple apoptotic corpses via efferocytosis to achieve tissue homeostasis1. How macrophages may rapidly adapt their transcription to achieve continuous corpse uptake is incompletely understood. Transcriptional pause/release is an evolutionarily conserved mechanism, in which RNA polymerase (Pol) II initiates transcription for 20-60 nucleotides, is paused for minutes to hours and is then released to make full-length mRNA2. Here we show that macrophages, within minutes of corpse encounter, use transcriptional pause/release to unleash a rapid transcriptional response. For human and mouse macrophages, the Pol II pause/release was required for continuous efferocytosis in vitro and in vivo. Interestingly, blocking Pol II pause/release did not impede Fc receptor-mediated phagocytosis, yeast uptake or bacterial phagocytosis. Integration of data from three genomic approaches-precision nuclear run-on sequencing, RNA sequencing, and assay for transposase-accessible chromatin using sequencing (ATAC-seq)-on efferocytic macrophages at different time points revealed that Pol II pause/release controls expression of select transcription factors and downstream target genes. Mechanistic studies on transcription factor EGR3, prominently regulated by pause/release, uncovered EGR3-related reprogramming of other macrophage genes involved in cytoskeleton and corpse processing. Using lysosomal probes and a new genetic fluorescent reporter, we identify a role for pause/release in phagosome acidification during efferocytosis. Furthermore, microglia from egr3-deficient zebrafish embryos displayed reduced phagocytosis of apoptotic neurons and fewer maturing phagosomes, supporting defective corpse processing. Collectively, these data indicate that macrophages use Pol II pause/release as a mechanism to rapidly alter their transcriptional programs for efficient processing of the ingested apoptotic corpses and for successive efferocytosis.


Assuntos
Eferocitose , Macrófagos , RNA Polimerase II , Elongação da Transcrição Genética , Animais , Humanos , Masculino , Camundongos , Apoptose , Citoesqueleto/metabolismo , Proteína 3 de Resposta de Crescimento Precoce/deficiência , Proteína 3 de Resposta de Crescimento Precoce/genética , Eferocitose/genética , Concentração de Íons de Hidrogênio , Macrófagos/imunologia , Macrófagos/metabolismo , Neurônios/metabolismo , Fagossomos/metabolismo , RNA Polimerase II/metabolismo , Fatores de Transcrição/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Fatores de Tempo
3.
Mol Cell ; 82(6): 1156-1168.e7, 2022 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-35219383

RESUMO

N6-methyladenosine (m6A) methylation is co-transcriptionally deposited on mRNA, but a possible role of m6A on transcription remains poorly understood. Here, we demonstrate that the METTL3/METTL14/WTAP m6A methyltransferase complex (MTC) is localized to many promoters and enhancers and deposits the m6A modification on nascent transcripts, including pre-mRNAs, promoter upstream transcripts (PROMPTs), and enhancer RNAs. PRO-seq analyses demonstrate that nascent RNAs originating from both promoters and enhancers are significantly decreased in the METTL3-depleted cells. Furthermore, genes targeted by the Integrator complex for premature termination are depleted of METTL3, suggesting a potential antagonistic relationship between METTL3 and Integrator. Consistently, we found the Integrator complex component INTS11 elevated at promoters and enhancers upon loss of MTC or nuclear m6A binders. Taken together, our findings suggest that MTC-mediated m6A modification protects nascent RNAs from Integrator-mediated termination and promotes productive transcription, thus unraveling an unexpected layer of gene regulation imposed by RNA m6A modification.


Assuntos
Cromatina , Metiltransferases , Cromatina/genética , Metilação , Metiltransferases/genética , Metiltransferases/metabolismo , RNA/genética , RNA/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
4.
Blood ; 139(13): 2024-2037, 2022 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-34936696

RESUMO

Immunomodulatory (IMiD) agents like lenalidomide and pomalidomide induce the recruitment of IKZF1 and other targets to the CRL4CRBN E3 ubiquitin ligase, resulting in their ubiquitination and degradation. These agents are highly active in B-cell lymphomas and a subset of myeloid diseases but have compromised effects in T-cell lymphomas (TCLs). Here, we show that 2 factors determine resistance to IMiDs among TCLs. First, limited CRBN expression reduces IMiD activity in TCLs but can be overcome by newer-generation degrader CC-92480. Using mass spectrometry, we show that CC-92480 selectively degrades IKZF1 and ZFP91 in TCL cells with greater potency than pomalidomide. As a result, CC-92480 is highly active against multiple TCL subtypes and showed greater efficacy than pomalidomide across 4 in vivo TCL models. Second, we demonstrate that ZFP91 functions as a bona fide transcription factor that coregulates cell survival with IKZF1 in IMiD-resistant TCLs. By activating keynote genes from WNT, NF-kB, and MAP kinase signaling, ZFP91 directly promotes resistance to IKZF1 loss. Moreover, lenalidomide-sensitive TCLs can acquire stable resistance via ZFP91 rewiring, which involves casein kinase 2-mediated c-Jun inactivation. Overall, these findings identify a critical transcription factor network within TCLs and provide clinical proof of concept for the novel therapy using next-generation degraders.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Fator de Transcrição Ikaros , Fatores Imunológicos/farmacologia , Linfoma de Células T , Mieloma Múltiplo , Ubiquitina-Proteína Ligases , Humanos , Fator de Transcrição Ikaros/metabolismo , Lenalidomida/farmacologia , Linfoma de Células T/tratamento farmacológico , Mieloma Múltiplo/tratamento farmacológico , Talidomida/análogos & derivados , Talidomida/farmacologia , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
5.
Nature ; 542(7639): 43-48, 2017 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-28099418

RESUMO

Interleukin-17 (IL-17) is a major pro-inflammatory cytokine: it mediates responses to pathogens or tissue damage, and drives autoimmune diseases. Little is known about its role in the nervous system. Here we show that IL-17 has neuromodulator-like properties in Caenorhabditis elegans. IL-17 can act directly on neurons to alter their response properties and contribution to behaviour. Using unbiased genetic screens, we delineate an IL-17 signalling pathway and show that it acts in the RMG hub interneurons. Disrupting IL-17 signalling reduces RMG responsiveness to input from oxygen sensors, and renders sustained escape from 21% oxygen transient and contingent on additional stimuli. Over-activating IL-17 receptors abnormally heightens responses to 21% oxygen in RMG neurons and whole animals. IL-17 deficiency can be bypassed by optogenetic stimulation of RMG. Inducing IL-17 expression in adults can rescue mutant defects within 6 h. These findings reveal a non-immunological role of IL-17 modulating circuit function and behaviour.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/citologia , Caenorhabditis elegans/fisiologia , Interleucina-17/metabolismo , Sensação/fisiologia , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Caenorhabditis elegans/efeitos dos fármacos , Células HEK293 , Humanos , Interneurônios/efeitos dos fármacos , Interneurônios/metabolismo , Oxigênio/metabolismo , Oxigênio/farmacologia , Receptores de Interleucina-17/metabolismo , Sensação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
6.
Angew Chem Int Ed Engl ; 54(51): 15570-3, 2015 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-26527364

RESUMO

Information-bearing nucleic acids display universal 3'-5' linkages, but regioisomeric 2'-5' linkages occur sporadically in non-enzymatic RNA synthesis and may have aided prebiotic RNA replication. Herein we report on the enzymatic synthesis of both DNA and RNA with site-specific 2'-5' linkages by an engineered polymerase using 3'-deoxy- or 3'-O-methyl-NTPs as substrates. We also report the reverse transcription of the resulting modified nucleic acids back to 3'-5' linked DNA with good fidelity. This enables a fast and simple method for "structural mutagenesis" by the position-selective incorporation of 2'-5' linkages, whereby nucleic acid structure and function may be probed through local distortion by regioisomeric linkages while maintaining the wild-type base sequence as we demonstrate for the 10-23 RNA endonuclease DNAzyme.


Assuntos
Enzimas/química , Ácidos Nucleicos/síntese química , Cromatografia Líquida de Alta Pressão
7.
Nat Commun ; 15(1): 848, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38287033

RESUMO

Male germ cell development requires precise regulation of gene activity in a cell-type and stage-specific manner, with perturbations in gene expression during spermatogenesis associated with infertility. Here, we use steady-state, nascent and single-cell RNA sequencing strategies to comprehensively characterize gene expression across male germ cell populations, to dissect the mechanisms of gene control and provide new insights towards therapy. We discover a requirement for pausing of RNA Polymerase II (Pol II) at the earliest stages of sperm differentiation to establish the landscape of gene activity across development. Accordingly, genetic knockout of the Pol II pause-inducing factor NELF in immature germ cells blocks differentiation to spermatids. Further, we uncover unanticipated roles for Pol II pausing in the regulation of meiosis during spermatogenesis, with the presence of paused Pol II associated with double-strand break (DSB) formation, and disruption of meiotic gene expression and DSB repair in germ cells lacking NELF.


Assuntos
RNA Polimerase II , Sêmen , Masculino , Humanos , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Sêmen/metabolismo , Meiose/genética , Espermatogênese/genética , Expressão Gênica
8.
bioRxiv ; 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37215034

RESUMO

Male germ cell development requires precise regulation of gene activity in a cell-type and stage-specific manner, with perturbations in gene expression during spermatogenesis associated with infertility. Here, we use steady-state, nascent and single-cell RNA sequencing strategies to comprehensively characterize gene expression across male germ cell populations, to dissect the mechanisms of gene control and provide new insights towards therapy. We discover a requirement for pausing of RNA Polymerase II (Pol II) at the earliest stages of sperm differentiation to establish the landscape of gene activity across development. Accordingly, genetic knockout of the Pol II pause-inducing factor NELF in immature germ cells blocks differentiation to mature spermatids. Further, we uncover unanticipated roles for Pol II pausing in the regulation of meiosis during spermatogenesis, with the presence of paused Pol II associated with double strand break formation by SPO11, and disruption of SPO11 expression in germ cells lacking NELF.

9.
Sci Transl Med ; 15(714): eadi7244, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37729434

RESUMO

Gene fusions involving tumor protein p63 gene (TP63) occur in multiple T and B cell lymphomas and portend a dismal prognosis for patients. The function and mechanisms of TP63 fusions remain unclear, and there is no target therapy for patients with lymphoma harboring TP63 fusions. Here, we show that TP63 fusions act as bona fide oncogenes and are essential for fusion-positive lymphomas. Transgenic mice expressing TBL1XR1::TP63, the most common TP63 fusion, develop diverse lymphomas that recapitulate multiple human T and B cell lymphomas. Here, we identify that TP63 fusions coordinate the recruitment of two epigenetic modifying complexes, the nuclear receptor corepressor (NCoR)-histone deacetylase 3 (HDAC3) by the N-terminal TP63 fusion partner and the lysine methyltransferase 2D (KMT2D) by the C-terminal TP63 component, which are both required for fusion-dependent survival. TBL1XR1::TP63 localization at enhancers drives a unique cell state that involves up-regulation of MYC and the polycomb repressor complex 2 (PRC2) components EED and EZH2. Inhibiting EZH2 with the therapeutic agent valemetostat is highly effective at treating transgenic lymphoma murine models, xenografts, and patient-derived xenografts harboring TP63 fusions. One patient with TP63-rearranged lymphoma showed a rapid response to valemetostat treatment. In summary, TP63 fusions link partner components that, together, coordinate multiple epigenetic complexes, resulting in therapeutic vulnerability to EZH2 inhibition.


Assuntos
Núcleo Celular , Oncogenes , Humanos , Animais , Camundongos , Ativação Transcricional , Proteínas Correpressoras , Modelos Animais de Doenças , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Fatores de Transcrição , Proteínas Supressoras de Tumor
10.
Dev Cell ; 56(7): 1014-1029.e7, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33735618

RESUMO

Negative elongation factor (NELF) is a critical transcriptional regulator that stabilizes paused RNA polymerase to permit rapid gene expression changes in response to environmental cues. Although NELF is essential for embryonic development, its role in adult stem cells remains unclear. In this study, through a muscle-stem-cell-specific deletion, we showed that NELF is required for efficient muscle regeneration and stem cell pool replenishment. In mechanistic studies using PRO-seq, single-cell trajectory analyses and myofiber cultures revealed that NELF works at a specific stage of regeneration whereby it modulates p53 signaling to permit massive expansion of muscle progenitors. Strikingly, transplantation experiments indicated that these progenitors are also necessary for stem cell pool repopulation, implying that they are able to return to quiescence. Thus, we identified a critical role for NELF in the expansion of muscle progenitors in response to injury and revealed that progenitors returning to quiescence are major contributors to the stem cell pool repopulation.


Assuntos
Músculo Esquelético/fisiologia , Células Satélites de Músculo Esquelético/fisiologia , Fatores de Transcrição/fisiologia , Animais , Diferenciação Celular , Células Cultivadas , Proteínas do Olho/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Desenvolvimento Muscular , Fatores de Crescimento Neural/metabolismo , Regeneração/genética , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/metabolismo , Células Satélites de Músculo Esquelético/transplante , Serpinas/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , Transcriptoma , Proteína Supressora de Tumor p53/metabolismo
11.
Neuron ; 105(1): 106-121.e10, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31757604

RESUMO

The extent to which behavior is shaped by experience varies between individuals. Genetic differences contribute to this variation, but the neural mechanisms are not understood. Here, we dissect natural variation in the behavioral flexibility of two Caenorhabditis elegans wild strains. In one strain, a memory of exposure to 21% O2 suppresses CO2-evoked locomotory arousal; in the other, CO2 evokes arousal regardless of previous O2 experience. We map that variation to a polymorphic dendritic scaffold protein, ARCP-1, expressed in sensory neurons. ARCP-1 binds the Ca2+-dependent phosphodiesterase PDE-1 and co-localizes PDE-1 with molecular sensors for CO2 at dendritic ends. Reducing ARCP-1 or PDE-1 activity promotes CO2 escape by altering neuropeptide expression in the BAG CO2 sensors. Variation in ARCP-1 alters behavioral plasticity in multiple paradigms. Our findings are reminiscent of genetic accommodation, an evolutionary process by which phenotypic flexibility in response to environmental variation is reset by genetic change.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Dendritos/metabolismo , Plasticidade Neuronal/fisiologia , Neuropeptídeos/biossíntese , Transdução de Sinais/fisiologia , Animais , Animais Geneticamente Modificados , Nível de Alerta/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Dióxido de Carbono/farmacologia , Feminino , Individualidade , Diester Fosfórico Hidrolases/metabolismo , Polimorfismo Genético , Células Receptoras Sensoriais/metabolismo , Especificidade da Espécie
12.
Nat Commun ; 11(1): 2099, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32350248

RESUMO

Besides pro-inflammatory roles, the ancient cytokine interleukin-17 (IL-17) modulates neural circuit function. We investigate IL-17 signaling in neurons, and the extent it can alter organismal phenotypes. We combine immunoprecipitation and mass spectrometry to biochemically characterize endogenous signaling complexes that function downstream of IL-17 receptors in C. elegans neurons. We identify the paracaspase MALT-1 as a critical output of the pathway. MALT1 mediates signaling from many immune receptors in mammals, but was not previously implicated in IL-17 signaling or nervous system function. C. elegans MALT-1 forms a complex with homologs of Act1 and IRAK and appears to function both as a scaffold and a protease. MALT-1 is expressed broadly in the C. elegans nervous system, and neuronal IL-17-MALT-1 signaling regulates multiple phenotypes, including escape behavior, associative learning, immunity and longevity. Our data suggest MALT1 has an ancient role modulating neural circuit function downstream of IL-17 to remodel physiology and behavior.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/imunologia , Caenorhabditis elegans/fisiologia , Imunidade , Interleucina-17/metabolismo , Longevidade , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/metabolismo , Neurônios/metabolismo , Animais , Comportamento Animal , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Fluorescência Verde/metabolismo , Imunidade/efeitos dos fármacos , Interneurônios/efeitos dos fármacos , Interneurônios/fisiologia , Longevidade/efeitos dos fármacos , Modelos Biológicos , Neurônios/efeitos dos fármacos , Oxigênio/farmacologia , Transdução de Sinais/efeitos dos fármacos , Frações Subcelulares/metabolismo , Transgenes
13.
Genome Biol ; 21(1): 73, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32293513

RESUMO

The three-dimensional conformation of a genome can be profiled using Hi-C, a technique that combines chromatin conformation capture with high-throughput sequencing. However, structural variations often yield features that can be mistaken for chromosomal interactions. Here, we describe a computational method HiNT (Hi-C for copy Number variation and Translocation detection), which detects copy number variations and interchromosomal translocations within Hi-C data with breakpoints at single base-pair resolution. We demonstrate that HiNT outperforms existing methods on both simulated and real data. We also show that Hi-C can supplement whole-genome sequencing in structure variant detection by locating breakpoints in repetitive regions.


Assuntos
Variações do Número de Cópias de DNA , Genômica/métodos , Translocação Genética , Pontos de Quebra do Cromossomo , Sequenciamento de Nucleotídeos em Larga Escala , Sequências Repetitivas de Ácido Nucleico , Análise de Sequência de DNA , Sequenciamento Completo do Genoma
14.
Cell Rep ; 28(9): 2331-2344.e8, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31461650

RESUMO

Cancer is often seen as a disease of mutations and chromosomal abnormalities. However, some cancers, including pediatric rhabdoid tumors (RTs), lack recurrent alterations targetable by current drugs and need alternative, informed therapeutic options. To nominate potential targets, we performed a high-throughput small-molecule screen complemented by a genome-scale CRISPR-Cas9 gene-knockout screen in a large number of RT and control cell lines. These approaches converged to reveal several receptor tyrosine kinases (RTKs) as therapeutic targets, with RTK inhibition effective in suppressing RT cell growth in vitro and against a xenograft model in vivo. RT cell lines highly express and activate (phosphorylate) different RTKs, creating dependency without mutation or amplification. Downstream of RTK signaling, we identified PTPN11, encoding the pro-growth signaling protein SHP2, as a shared dependency across all RT cell lines. This study demonstrates that large-scale perturbational screening can uncover vulnerabilities in cancers with "quiet" genomes.


Assuntos
Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 11/antagonistas & inibidores , Tumor Rabdoide/genética , Animais , Antineoplásicos/uso terapêutico , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Nus , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Tumor Rabdoide/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/farmacologia
15.
Nat Neurosci ; 18(10): 1501-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26368943

RESUMO

Cognitive inhibitory control, the ability to rapidly suppress responses inappropriate for the context, is essential for flexible and adaptive behavior. Although most studies on inhibitory control have focused on the fronto-basal-ganglia circuit, we found that rapid behavioral stopping is enabled by neuronal inhibition in the basal forebrain (BF). In rats performing the stop signal task, putative noncholinergic BF neurons with phasic bursting responses to the go signal were nearly completely inhibited by the stop signal. The onset of BF neuronal inhibition was tightly coupled with and temporally preceded the latency to stop, the stop signal reaction time. Artificial inhibition of BF activity in the absence of the stop signal was sufficient to reproduce rapid behavioral stopping. These results reveal a previously unknown subcortical mechanism of rapid inhibitory control by the BF, which provides bidirectional control over the speed of response generation and inhibition.


Assuntos
Prosencéfalo Basal/fisiologia , Comportamento Animal/fisiologia , Inibição Psicológica , Inibição Neural/fisiologia , Animais , Eletrodos Implantados , Masculino , Ratos , Ratos Long-Evans , Fatores de Tempo
16.
Elife ; 42015 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-25760081

RESUMO

Brains organize behavior and physiology to optimize the response to threats or opportunities. We dissect how 21% O2, an indicator of surface exposure, reprograms C. elegans' global state, inducing sustained locomotory arousal and altering expression of neuropeptides, metabolic enzymes, and other non-neural genes. The URX O2-sensing neurons drive arousal at 21% O2 by tonically activating the RMG interneurons. Stimulating RMG is sufficient to switch behavioral state. Ablating the ASH, ADL, or ASK sensory neurons connected to RMG by gap junctions does not disrupt arousal. However, disrupting cation currents in these neurons curtails RMG neurosecretion and arousal. RMG signals high O2 by peptidergic secretion. Neuropeptide reporters reveal neural circuit state, as neurosecretion stimulates neuropeptide expression. Neural imaging in unrestrained animals shows that URX and RMG encode O2 concentration rather than behavior, while the activity of downstream interneurons such as AVB and AIY reflect both O2 levels and the behavior being executed.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Interneurônios/efeitos dos fármacos , Rede Nervosa/efeitos dos fármacos , Oxigênio/farmacologia , Células Receptoras Sensoriais/efeitos dos fármacos , Animais , Animais Geneticamente Modificados , Nível de Alerta/genética , Comportamento Animal , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Cálcio/metabolismo , Junções Comunicantes/efeitos dos fármacos , Junções Comunicantes/metabolismo , Regulação da Expressão Gênica , Interneurônios/citologia , Interneurônios/metabolismo , Transporte de Íons , Locomoção/genética , Rede Nervosa/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Canais de Potássio/genética , Canais de Potássio/metabolismo , Receptores de Neuropeptídeo Y/genética , Receptores de Neuropeptídeo Y/metabolismo , Células Receptoras Sensoriais/citologia , Células Receptoras Sensoriais/metabolismo , Transdução de Sinais , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/metabolismo
17.
Front Neurosci ; 8: 104, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24847204

RESUMO

Inhibiting actions inappropriate for the behavioral context, or inhibitory control, is essential for survival and involves both reactively stopping the current prepared action and proactively adjusting behavioral tendencies to increase future performance. A powerful paradigm widely used in basic and clinical research to study inhibitory control is the stop signal task (SST). Recent years have seen a surging interest in translating the SST to rodents to study the neural mechanisms underlying inhibitory control. However, significant differences in task designs and behavioral strategies between rodent and primate studies have made it difficult to directly compare the two literatures. In this study, we developed a rodent-appropriate SST and characterized both reactive and proactive control in rats. For reactive inhibitory control, we found that, unlike in primates, incorrect stop trials in rodents result from two independent types of errors: an initial failure-to-stop error or, after successful stopping, a subsequent failure-to-wait error. Conflating failure-to-stop and failure-to-wait errors systematically overestimates the covert latency of reactive inhibition, the stop signal reaction time (SSRT). To correctly estimate SSRT, we developed and validated a new method that provides an unbiased SSRT estimate independent of the ability to wait. For proactive inhibitory control, we found that rodents adjust both their reaction time and the ability to stop following failure-to-wait errors and successful stop trials, but not after failure-to-stop errors. Together, these results establish a valid rodent model that utilizes proactive and reactive inhibitory control strategies similar to primates, and highlight the importance of dissociating initial stopping from subsequent waiting in studying mechanisms of inhibitory control using rodents.

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