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1.
Cell ; 167(7): 1762-1773.e12, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27984726

RESUMO

Overlapping genes pose an evolutionary dilemma as one DNA sequence evolves under the selection pressures of multiple proteins. Here, we perform systematic statistical and mutational analyses of the overlapping HIV-1 genes tat and rev and engineer exhaustive libraries of non-overlapped viruses to perform deep mutational scanning of each gene independently. We find a "segregated" organization in which overlapped sites encode functional residues of one gene or the other, but never both. Furthermore, this organization eliminates unfit genotypes, providing a fitness advantage to the population. Our comprehensive analysis reveals the extraordinary manner in which HIV minimizes the constraint of overlapping genes and repurposes that constraint to its own advantage. Thus, overlaps are not just consequences of evolutionary constraints, but rather can provide population fitness advantages.


Assuntos
Evolução Biológica , HIV-1/genética , Produtos do Gene tat do Vírus da Imunodeficiência Humana/genética , Entropia , Aptidão Genética , Infecções por HIV/virologia , Humanos , Mutação , Fases de Leitura Aberta , Produtos do Gene rev do Vírus da Imunodeficiência Humana/genética
2.
J Cell Sci ; 137(1)2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38059420

RESUMO

The Rac1-WAVE-Arp2/3 pathway pushes the plasma membrane by polymerizing branched actin, thereby powering membrane protrusions that mediate cell migration. Here, using knockdown (KD) or knockout (KO), we combine the inactivation of the Arp2/3 inhibitory protein arpin, the Arp2/3 subunit ARPC1A and the WAVE complex subunit CYFIP2, all of which enhance the polymerization of cortical branched actin. Inactivation of the three negative regulators of cortical branched actin increases migration persistence of human breast MCF10A cells and of endodermal cells in the zebrafish embryo, significantly more than any single or double inactivation. In the triple KO cells, but not in triple KD cells, the 'super-migrator' phenotype was associated with a heterogenous downregulation of vimentin (VIM) expression and a lack of coordination in collective behaviors, such as wound healing and acinus morphogenesis. Re-expression of vimentin in triple KO cells largely restored normal persistence of single cell migration, suggesting that vimentin downregulation contributes to the maintenance of the super-migrator phenotype in triple KO cells. Constant excessive production of branched actin at the cell cortex thus commits cells into a motile state through changes in gene expression.


Assuntos
Actinas , Peixe-Zebra , Animais , Humanos , Actinas/metabolismo , Vimentina/genética , Vimentina/metabolismo , Peixe-Zebra/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Movimento Celular/fisiologia , Proteínas de Transporte/metabolismo
3.
Nucleic Acids Res ; 52(10): 5928-5949, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38412259

RESUMO

A GGGGCC (G4C2) hexanucleotide repeat expansion in C9ORF72 causes amyotrophic lateral sclerosis and frontotemporal dementia (C9ALS/FTD), while a CGG trinucleotide repeat expansion in FMR1 leads to the neurodegenerative disorder Fragile X-associated tremor/ataxia syndrome (FXTAS). These GC-rich repeats form RNA secondary structures that support repeat-associated non-AUG (RAN) translation of toxic proteins that contribute to disease pathogenesis. Here we assessed whether these same repeats might trigger stalling and interfere with translational elongation. We find that depletion of ribosome-associated quality control (RQC) factors NEMF, LTN1 and ANKZF1 markedly boost RAN translation product accumulation from both G4C2 and CGG repeats while overexpression of these factors reduces RAN production in both reporter assays and C9ALS/FTD patient iPSC-derived neurons. We also detected partially made products from both G4C2 and CGG repeats whose abundance increased with RQC factor depletion. Repeat RNA sequence, rather than amino acid content, is central to the impact of RQC factor depletion on RAN translation-suggesting a role for RNA secondary structure in these processes. Together, these findings suggest that ribosomal stalling and RQC pathway activation during RAN translation inhibits the generation of toxic RAN products. We propose augmenting RQC activity as a therapeutic strategy in GC-rich repeat expansion disorders.


Assuntos
Esclerose Lateral Amiotrófica , Proteína C9orf72 , Demência Frontotemporal , Biossíntese de Proteínas , Proteínas Ribossômicas , Expansão das Repetições de Trinucleotídeos , Humanos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Ataxia , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Expansão das Repetições de DNA/genética , Proteína do X Frágil da Deficiência Intelectual/genética , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Síndrome do Cromossomo X Frágil/genética , Síndrome do Cromossomo X Frágil/metabolismo , Demência Frontotemporal/genética , Demência Frontotemporal/metabolismo , Sequência Rica em GC , Células HEK293 , Células-Tronco Pluripotentes Induzidas/metabolismo , Neurônios/metabolismo , Ribossomos/metabolismo , Ribossomos/genética , Tremor , Expansão das Repetições de Trinucleotídeos/genética , Proteínas Ribossômicas/metabolismo
4.
Development ; 149(4)2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35029679

RESUMO

To investigate the role of mechanical constraints in morphogenesis and development, we have developed a pipeline of techniques based on incompressible elastic sensors. These techniques combine the advantages of incompressible liquid droplets, which have been used as precise in situ shear stress sensors, and of elastic compressible beads, which are easier to tune and to use. Droplets of a polydimethylsiloxane mix, made fluorescent through specific covalent binding to a rhodamin dye, are produced by a microfluidics device. The elastomer rigidity after polymerization is adjusted to the tissue rigidity. Its mechanical properties are carefully calibrated in situ, for a sensor embedded in a cell aggregate submitted to uniaxial compression. The local shear stress tensor is retrieved from the sensor shape, accurately reconstructed through an active contour method. In vitro, within cell aggregates, and in vivo, in the prechordal plate of the zebrafish embryo during gastrulation, our pipeline of techniques demonstrates its efficiency to directly measure the three dimensional shear stress repartition within a tissue.


Assuntos
Embrião não Mamífero/citologia , Imageamento Tridimensional/métodos , Resistência ao Cisalhamento , Animais , Agregação Celular , Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Linhagem Celular Tumoral , Embrião não Mamífero/metabolismo , Camundongos , Microscopia de Fluorescência por Excitação Multifotônica , Peixe-Zebra
5.
Glia ; 72(2): 300-321, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37937831

RESUMO

Neuropsychiatric complications including depression and cognitive decline develop in the years after traumatic brain injury (TBI), negatively affecting quality of life. Microglial and type 1 interferon (IFN-I) responses are associated with the transition from acute to chronic neuroinflammation after diffuse TBI in mice. Thus, the purpose of this study was to determine if impaired neuronal homeostasis and increased IFN-I responses intersected after TBI to cause cognitive impairment. Here, the RNA profile of neurons and microglia after TBI (single nucleus RNA-sequencing) with or without microglia depletion (CSF1R antagonist) was assessed 7 dpi. There was a TBI-dependent suppression of cortical neuronal homeostasis with reductions in CREB signaling, synaptogenesis, and synaptic migration and increases in RhoGDI and PTEN signaling (Ingenuity Pathway Analysis). Microglial depletion reversed 50% of TBI-induced gene changes in cortical neurons depending on subtype. Moreover, the microglial RNA signature 7 dpi was associated with increased stimulator of interferon genes (STING) activation and IFN-I responses. Therefore, we sought to reduce IFN-I signaling after TBI using STING knockout mice and a STING antagonist, chloroquine (CQ). TBI-associated cognitive deficits in novel object location and recognition (NOL/NOR) tasks at 7 and 30 dpi were STING dependent. In addition, TBI-induced STING expression, microglial morphological restructuring, inflammatory (Tnf, Cd68, Ccl2) and IFN-related (Irf3, Irf7, Ifi27) gene expression in the cortex were attenuated in STINGKO mice. CQ also reversed TBI-induced cognitive deficits and reduced TBI-induced inflammatory (Tnf, Cd68, Ccl2) and IFN (Irf7, Sting) cortical gene expression. Collectively, reducing IFN-I signaling after TBI with STING-dependent interventions attenuated the prolonged microglial activation and cognitive impairment.


Assuntos
Lesões Encefálicas Traumáticas , Interferon Tipo I , Camundongos , Animais , Interferon Tipo I/metabolismo , Microglia/metabolismo , Qualidade de Vida , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/metabolismo , Cognição , Neurônios/metabolismo , RNA/metabolismo , Camundongos Endogâmicos C57BL
6.
BMC Genomics ; 25(1): 199, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38378469

RESUMO

BACKGROUND: Abiotic stresses in plants include all the environmental conditions that significantly reduce yields, like drought and heat. One of the most significant effects they exert at the cellular level is the accumulation of reactive oxygen species, which cause extensive damage. Plants possess two mechanisms to counter these molecules, i.e. detoxifying enzymes and non-enzymatic antioxidants, which include many classes of specialized metabolites. Sunflower, the fourth global oilseed, is considered moderately drought resistant. Abiotic stress tolerance in this crop has been studied using many approaches, but the control of specialized metabolites in this context remains poorly understood. Here, we performed the first genome-wide association study using abiotic stress-related specialized metabolites as molecular phenotypes in sunflower. After analyzing leaf specialized metabolites of 450 hybrids using liquid chromatography-mass spectrometry, we selected a subset of these compounds based on their association with previously known abiotic stress-related quantitative trait loci. Eventually, we characterized these molecules and their associated genes. RESULTS: We putatively annotated 30 compounds which co-localized with abiotic stress-related quantitative trait loci and which were associated to seven most likely candidate genes. A large proportion of these compounds were potential antioxidants, which was in agreement with the role of specialized metabolites in abiotic stresses. The seven associated most likely candidate genes, instead, mainly belonged to cytochromes P450 and glycosyltransferases, two large superfamilies which catalyze greatly diverse reactions and create a wide variety of chemical modifications. This was consistent with the high plasticity of specialized metabolism in plants. CONCLUSIONS: This is the first characterization of the genetic control of abiotic stress-related specialized metabolites in sunflower. By providing hints concerning the importance of antioxidant molecules in this biological context, and by highlighting some of the potential molecular mechanisms underlying their biosynthesis, it could pave the way for novel applications in breeding. Although further analyses will be required to better understand this topic, studying how antioxidants contribute to the tolerance to abiotic stresses in sunflower appears as a promising area of research.


Assuntos
Helianthus , Helianthus/genética , Helianthus/metabolismo , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Estresse Fisiológico/genética , Plantas/genética , Antioxidantes/metabolismo , Regulação da Expressão Gênica de Plantas
7.
Biophys J ; 122(17): 3506-3515, 2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37528581

RESUMO

E-cadherin plays a central role in cell-cell adhesion. The ectodomains of wild-type cadherins form a crystalline-like two-dimensional lattice in cell-cell interfaces mediated by both trans (apposed cell) and cis (same cell) interactions. In addition to these extracellular forces, adhesive strength is further regulated by cytosolic phenomena involving α and ß catenin-mediated interactions between cadherin and the actin cytoskeleton. Cell-cell adhesion can be further strengthened under tension through mechanisms that have not been definitively characterized in molecular detail. Here we quantitatively determine the role of the cadherin ectodomain in mechanosensing. To this end, we devise an E-cadherin-coated emulsion system, in which droplet surface tension is balanced by protein binding strength to give rise to stable areas of adhesion. To reach the honeycomb/cohesive limit, an initial emulsion compression by centrifugation facilitates E-cadherin trans binding, whereas a high protein surface concentration enables the cis-enhanced stabilization of the interface. We observe an abrupt concentration dependence on recruitment into adhesions of constant crystalline density, reminiscent of a first-order phase transition. Removing the lateral cis interaction with a "cis mutant" shifts this transition to higher surface densities leading to denser, yet weaker adhesions. In both proteins, the stabilization of progressively larger areas of deformation is consistent with single-molecule experiments that show a force-dependent lifetime enhancement in the cadherin ectodomain, which may be attributed to the "X-dimer" bond.


Assuntos
Biomimética , Caderinas , Emulsões , Caderinas/metabolismo , Adesão Celular , Ligação Proteica
8.
Bioinformatics ; 38(17): 4127-4134, 2022 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-35792837

RESUMO

MOTIVATION: Inferring gene regulatory networks in non-independent genetically related panels is a methodological challenge. This hampers evolutionary and biological studies using heterozygote individuals such as in wild sunflower populations or cultivated hybrids. RESULTS: First, we simulated 100 datasets of gene expressions and polymorphisms, displaying the same gene expression distributions, heterozygosities and heritabilities as in our dataset including 173 genes and 353 genotypes measured in sunflower hybrids. Secondly, we performed a meta-analysis based on six inference methods [least absolute shrinkage and selection operator (Lasso), Random Forests, Bayesian Networks, Markov Random Fields, Ordinary Least Square and fast inference of networks from directed regulation (Findr)] and selected the minimal density networks for better accuracy with 64 edges connecting 79 genes and 0.35 area under precision and recall (AUPR) score on average. We identified that triangles and mutual edges are prone to errors in the inferred networks. Applied on classical datasets without heterozygotes, our strategy produced a 0.65 AUPR score for one dataset of the DREAM5 Systems Genetics Challenge. Finally, we applied our method to an experimental dataset from sunflower hybrids. We successfully inferred a network composed of 105 genes connected by 106 putative regulations with a major connected component. AVAILABILITY AND IMPLEMENTATION: Our inference methodology dedicated to genomic and transcriptomic data is available at https://forgemia.inra.fr/sunrise/inference_methods. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Redes Reguladoras de Genes , Transcriptoma , Humanos , Heterozigoto , Teorema de Bayes , Genômica , Algoritmos
9.
Ann Vasc Surg ; 95: 262-270, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37121337

RESUMO

BACKGROUND: Failure to rescue (FtR), or inpatient death following complication, is a publicly reported hospital quality measure. Previous work has demonstrated significant variation in the proportion of frail patients across hospitals. However, frailty is not incorporated into risk-adjustment algorithms for hospital quality comparisons and risk adjustment is made by comorbidity scores. Our aim was to assess the impact of frailty on FtR quality measurement and as a means of risk adjustment. METHODS: Patients undergoing open or endovascular aneurysm repair or lower extremity bypass in the Vascular Quality Initiative (VQI) at centers performing ≥ 25 vascular procedures annually (2003-2019) were included. Multivariable logistic regression evaluated in-hospital death using scaled hierarchical modeling clustering at the center level. Center FtR observed/expected ratios were compared with expected values adjusted for either standard comorbidity profiles or frailty as measured by the VQI Risk Analysis Index. Centers were divided into quartiles using VQI-linked American Hospital Association data to describe the hospital characteristics of centers whose ranks changed. RESULTS: A total of 63,143 patients (213 centers) were included; 1,630 patients (2.58%) were classified as FtR. After accounting for center-level variability, frailty was associated with FtR [scaled odds ratio 1.9 (1.8-2.0), P < 0.001]. The comorbidity-centric and frailty-based models performed similarly in predicting FtR with C-statistics of 0.85 (0.84-0.86) and 0.82 (0.82-0.84), respectively. Overall changes in ranking based on observed/expected ratios were not statistically significant (P = 0.48). High and low performing centers had similar ranking using comorbidity-centric and frailty-based methods; however, centers in the middle of the performance spectrum saw more variability in ranking alterations. Forty nine (23%) of hospitals improved their ranking by five or more positions when using frailty versus comorbidity risk adjustment. The centers in Quartile 4, those who performed the highest number of vascular procedures annually, experience on average a significant improvement in hospital ranking when frailty was used for risk adjustment, whereas centers performing the fewest number of vascular procedures and the lowest proportion of vascular surgery cases annually (Quartile 1) saw a significant worsening of ranking position (all P < 0.05). However, total number of surgical procedures annually, total hospital beds, for-profit status, and teaching hospital status were not significantly associated with changes in rank. CONCLUSIONS: A simple frailty-adjusted model has similar predictive abilities as a comorbidity-focused model for predicting a common quality metric that influences reimbursement. In addition to distilling the risk-adjustment algorithm to a few variables, frailty can be assessed preoperatively to develop quality improvement efforts for rescuing frail patients. Centers treating a greater proportion of frail patients and those who perform higher volumes of vascular surgery benefit from a risk adjustment strategy based on frailty.


Assuntos
Aneurisma da Aorta Abdominal , Implante de Prótese Vascular , Procedimentos Endovasculares , Fragilidade , Estados Unidos/epidemiologia , Humanos , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Fragilidade/complicações , Aneurisma da Aorta Abdominal/cirurgia , Mortalidade Hospitalar , Procedimentos Endovasculares/efeitos adversos , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento , Implante de Prótese Vascular/efeitos adversos , Hospitais , Comorbidade , Estudos Retrospectivos , Fatores de Risco
10.
Int J Mol Sci ; 24(11)2023 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-37298305

RESUMO

Cultivated sunflower (Helianthus annuus L.) exhibits numerous phenotypic and transcriptomic responses to drought. However, the ways in which these responses vary with differences in drought timing and severity are insufficiently understood. We used phenotypic and transcriptomic data to evaluate the response of sunflower to drought scenarios of different timing and severity in a common garden experiment. Using a semi-automated outdoor high-throughput phenotyping platform, we grew six oilseed sunflower lines under control and drought conditions. Our results reveal that similar transcriptomic responses can have disparate phenotypic effects when triggered at different developmental time points. Leaf transcriptomic responses, however, share similarities despite timing and severity differences (e.g., 523 differentially expressed genes (DEGs) were shared across all treatments), though increased severity elicited greater differences in expression, particularly during vegetative growth. Across treatments, DEGs were highly enriched for genes related to photosynthesis and plastid maintenance. A co-expression analysis identified a single module (M8) enriched in all drought stress treatments. Genes related to drought, temperature, proline biosynthesis, and other stress responses were overrepresented in this module. In contrast to transcriptomic responses, phenotypic responses were largely divergent between early and late drought. Early-stressed sunflowers responded to drought with reduced overall growth, but became highly water-acquisitive during recovery irrigation, resulting in overcompensation (higher aboveground biomass and leaf area) and a greater overall shift in phenotypic correlations, whereas late-stressed sunflowers were smaller and more water use-efficient. Taken together, these results suggest that drought stress at an earlier growth stage elicits a change in development that enables greater uptake and transpiration of water during recovery, resulting in higher growth rates despite similar initial transcriptomic responses.


Assuntos
Helianthus , Helianthus/metabolismo , Transcriptoma , Secas , Fenótipo , Água/metabolismo
11.
Theor Appl Genet ; 135(11): 4049-4063, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35294575

RESUMO

KEY MESSAGE: Crop simulation helps to analyze environmental impacts on crops and provides year-independent context information. This information is of major importance when deciding which cultivar to choose at sowing time. Plant breeding programs design new crop cultivars which, while developed for distinct populations of environments, are nevertheless grown over large areas during their time in the market. Over its cultivation area, the crop is exposed to highly diverse stress patterns caused by climatic uncertainty and multiple management options, which often leads to decreased expected crop performance. In this study, we aim to assess how finer spatial management of genetic resources could reduce the yield variance explained by genotype × environment interactions in a set of cropping environments and ultimately improve the efficiency and stability of crop production. We used modeling and simulation to predict the crop performance resulting from the interaction between cultivar growth and development, climate and soil conditions, and management practices. We designed a computational experiment that evaluated the performance of a collection of commercial sunflower cultivars in a realistic population of cropping conditions in France, built from extensive agricultural surveys. Distinct farming locations sharing similar simulated abiotic stress patterns were clustered together to specify environment types. We then used optimization methods to search for cultivars × environments combinations leading to increased yield expectations. Results showed that a single cultivar choice adapted to the most frequent environment-type in the population is a robust strategy. However, the relevance of cultivar recommendations to specific locations was gradually increasing with the knowledge of pedo-climatic conditions. We argue that this approach while being operational on current genetic material could act synergistically with plant breeding as more diverse material could enable access to cultivars with distinctive traits, more adapted to specific conditions.


Assuntos
Helianthus , Helianthus/genética , França
12.
Brain ; 144(11): 3461-3476, 2021 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-34115105

RESUMO

TDP-43 nuclear depletion and concurrent cytoplasmic accumulation in vulnerable neurons is a hallmark feature of progressive neurodegenerative proteinopathies such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Cellular stress signalling and stress granule dynamics are now recognized to play a role in ALS/FTD pathogenesis. Defective stress granule assembly is associated with increased cellular vulnerability and death. Ras-GAP SH3-domain-binding protein 1 (G3BP1) is a critical stress granule assembly factor. Here, we define that TDP-43 stabilizes G3BP1 transcripts via direct binding of a highly conserved cis regulatory element within the 3' untranslated region. Moreover, we show in vitro and in vivo that nuclear TDP-43 depletion is sufficient to reduce G3BP1 protein levels. Finally, we establish that G3BP1 transcripts are reduced in ALS/FTD patient neurons bearing TDP-43 cytoplasmic inclusions/nuclear depletion. Thus, our data indicate that, in ALS/FTD, there is a compromised stress granule response in disease-affected neurons due to impaired G3BP1 mRNA stability caused by TDP-43 nuclear depletion. These data implicate TDP-43 and G3BP1 loss of function as contributors to disease.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , DNA Helicases/metabolismo , Proteínas de Ligação a DNA/metabolismo , Demência Frontotemporal/metabolismo , Neurônios/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Esclerose Lateral Amiotrófica/patologia , Células Cultivadas , Demência Frontotemporal/patologia , Humanos , Neurônios/patologia , RNA Mensageiro
13.
J Neurosci ; 40(2): 311-326, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31767679

RESUMO

During mammalian development, gonadotropin-releasing-hormone-1 neurons (GnRH-1ns) migrate from the developing vomeronasal organ (VNO) into the brain asserting control of pubertal onset and fertility. Recent data suggest that correct development of the olfactory ensheathing cells (OEC) is imperative for normal GnRH-1 neuronal migration. However, the full ensemble of molecular pathways that regulate OEC development remains to be fully deciphered. Loss-of-function of the transcription factor Gli3 is known to disrupt olfactory development, however, if Gli3 plays a role in GnRH-1 neuronal development is unclear. By analyzing Gli3 extra-toe mutants (Gli3Xt/Xt), we found that Gli3 loss-of-function compromises the onset of achaete-scute family bHLH transcription factor 1 (Ascl-1)+ vomeronasal progenitors and the formation of OEC in the nasal mucosa. Surprisingly, GnRH-1 neurogenesis was intact in Gli3Xt/Xt mice but they displayed significant defects in GnRH-1 neuronal migration. In contrast, Ascl-1null mutants showed reduced neurogenesis for both vomeronasal and GnRH-1ns but less severe defects in OEC development. These observations suggest that Gli3 is critical for OEC development in the nasal mucosa and subsequent GnRH-1 neuronal migration. However, the nonoverlapping phenotypes between Ascl-1 and Gli3 mutants indicate that Ascl-1, while crucial for GnRH-1 neurogenesis, is not required for normal OEC development. Because Kallmann syndrome (KS) is characterized by abnormal GnRH-1ns migration, we examined whole-exome sequencing data from KS subjects. We identified and validated a GLI3 loss-of-function variant in a KS individual. These findings provide new insights into GnRH-1 and OECs development and demonstrate that human GLI3 mutations contribute to KS etiology.SIGNIFICANCE STATEMENT The transcription factor Gli3 is necessary for correct development of the olfactory system. However, if Gli3 plays a role in controlling GnRH-1 neuronal development has not been addressed. We found that Gli3 loss-of-function compromises the onset of Ascl-1+ vomeronasal progenitors, formation of olfactory ensheathing cells in the nasal mucosa, and impairs GnRH-1 neuronal migration to the brain. By analyzing Ascl-1null mutants we dissociated the neurogenic defects observed in Gli3 mutants from lack of olfactory ensheathing cells in the nasal mucosa, moreover, we discovered that Ascl-1 is necessary for GnRH-1 ontogeny. Analyzing human whole-exome sequencing data, we identified a GLI3 loss-of-function variant in a KS individual. Our data suggest that GLI3 is a candidate gene contributing to KS etiology.


Assuntos
Síndrome de Kallmann/genética , Neurogênese/fisiologia , Neuroglia/fisiologia , Neurônios/fisiologia , Órgão Vomeronasal/fisiologia , Proteína Gli3 com Dedos de Zinco/metabolismo , Animais , Movimento Celular/fisiologia , Feminino , Hormônio Liberador de Gonadotropina/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Bulbo Olfatório/crescimento & desenvolvimento , Mucosa Olfatória/metabolismo , Precursores de Proteínas/metabolismo , Proteína Gli3 com Dedos de Zinco/genética
14.
Mol Pharmacol ; 100(2): 66-81, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34011569

RESUMO

Termination of antidepressant therapy often has negative consequences. Although symptoms of antidepressant withdrawal are widely recognized, the molecular processes that underlie them are not well characterized. We show that certain aspects of Gα s signaling remain suppressed after antidepressant withdrawal, even after others have reverted to baseline. Antidepressant treatment causes translocation of Gα s protein from lipid rafts to nonraft membrane regions. This results in augmented Gα s signaling, including facilitated activation of adenylyl cyclase and increased cAMP accumulation. Using CC6 or SK-N-SH cells and a lipid raft-localized cAMP sensor, we show that Gα s signaling is reduced in lipid rafts, even while signaling is enhanced elsewhere in the cell. These signaling changes mirror the changes in Gα s localization observed after antidepressant treatment. Furthermore, we show that suppression of Gα s signaling in lipid rafts persists at least 24 hours after cessation of antidepressant treatment. Gα s localization was quantified after membrane isolation and sequential detergent extraction. We show that suppression of lipid raft Gα s signaling persists for an extended time period after antidepressant withdrawal, whereas increased nonraft membrane Gα s signaling reverts partially or fully upon cessation of antidepressant treatment. Translocation of Gα s out of lipid rafts is also persistent. These events may reflect cellular adaptations to antidepressant treatment that contribute to antidepressant discontinuation syndromes and may aid in the discovery of new treatments and strategies to mitigate the symptoms of depression and antidepressant withdrawal. SIGNIFICANCE STATEMENT: This work explores, for the first time, the effects of antidepressants on Gα s signaling after drug withdrawal. This provides novel insight into the cellular and molecular processes affected by antidepressant drugs and their persistence after discontinuation of treatment.


Assuntos
Antidepressivos/farmacologia , Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Microdomínios da Membrana/metabolismo , Animais , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Microdomínios da Membrana/efeitos dos fármacos , Ratos , Transdução de Sinais/efeitos dos fármacos
15.
BMC Genomics ; 22(1): 893, 2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34906091

RESUMO

BACKGROUND: Leaf senescence delay impacts positively in grain yield by maintaining the photosynthetic area during the reproductive stage and during grain filling. Therefore a comprehensive understanding of the gene families associated with leaf senescence is essential. NAC transcription factors (TF) form a large plant-specific gene family involved in regulating development, senescence, and responses to biotic and abiotic stresses. The main goal of this work was to identify sunflower NAC TF (HaNAC) and their association with senescence, studying their orthologous to understand possible functional relationships between genes of different species. RESULTS: To clarify the orthologous relationships, we used an in-depth comparative study of four divergent taxa, in dicots and monocots, with completely sequenced genomes (Arabidopsis thaliana, Vitis vinifera, Musa acuminata and Oryza sativa). These orthologous groups provide a curated resource for large scale protein sequence annotation of NAC TF. From the 151 HaNAC genes detected in the latest version of the sunflower genome, 50 genes were associated with senescence traits. These genes showed significant differential expression in two contrasting lines according to an RNAseq assay. An assessment of overexpressing the Arabidopsis line for HaNAC001 (a gene of the same orthologous group of Arabidopsis thaliana ORE1) revealed that this line displayed a significantly higher number of senescent leaves and a pronounced change in development rate. CONCLUSIONS: This finding suggests HaNAC001 as an interesting candidate to explore the molecular regulation of senescence in sunflower.


Assuntos
Helianthus , Proteínas de Plantas , Senescência Vegetal , Fatores de Transcrição , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Helianthus/genética , Helianthus/metabolismo , Filogenia , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Senescência Vegetal/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
J Surg Res ; 266: 69-76, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33984733

RESUMO

INTRODUCTION: Prior work suggests women surgical role models attract more female medical students into surgical training. We investigate recent trends of women in surgical society leadership and national conference moderator and plenary speaker roles. METHODS: Gender distribution was surveyed at 15 major surgical societies and 14 conferences from 2014 to 2018 using publicly reported data. Roles were categorized as leadership (executive council), moderator, or plenary speaker. Data were cross-checked from online profiles and by contacting societies. Logistic regression with Huber-White clustering by society was utilized to evaluate proportions of women in each role over time and determine associations between the proportion of women in executive leadership, and scientific session moderators and plenary speakers. RESULTS: The proportion of leadership positions held by women increased slightly from 2014 to 2018 (20.6%-26.6%, P = 0.23), as did the proportion of moderators (26.2%-30.6%, P = 0.027) and plenary speakers (26.2%-30.9%, P = 0.058). The proportion of women in each role varied significantly across societies (all P < 0.001): leaders (range 0.0%-52.0%), moderators (12.5%-58.8%), and plenary speakers (11.3%-60.0%). Three patterns of change were observed: eight societies (53.3%) demonstrated increases in representation of women over time, four societies (26.6%) showed stable moderate-to-good gender balance, and three societies (20.0%) had consistent underrepresentation of women. CONCLUSION: There is significant variability in the representation of women at the leadership level of national surgical societies and participating at national surgical conferences as moderators and plenary speakers. Over the past 5 years some societies have achieved advances in gender equity, but many societies still have substantial room for improvement.


Assuntos
Congressos como Assunto/organização & administração , Equidade de Gênero , Liderança , Médicas/organização & administração , Sexismo/tendências , Sociedades Médicas/organização & administração , Especialidades Cirúrgicas/organização & administração , Congressos como Assunto/tendências , Feminino , Humanos , Modelos Logísticos , Masculino , Médicas/tendências , Sociedades Médicas/tendências , Especialidades Cirúrgicas/tendências , Estados Unidos
17.
BMC Musculoskelet Disord ; 22(1): 282, 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33731070

RESUMO

BACKGROUND: The strength and size of core muscles, including the abdominal muscles, are crucial to proper function in most activities. Therefore, it is important to reliably assess these characteristics. Our primary objective was to determine if the length, thickness and cross-sectional area of the transversus abdominis (TrA) can be visualized independently from the internal and external abdominal oblique muscles using extended field of view ultrasound imaging at rest and with contraction and to establish its intra- and inter-tester reliability. METHODS: Twenty-six individuals were recruited to participate in the study (20 F, 6 M), average age 24.0 years (SD 9.4), height 170.7 cm (SD 8.6) and weight 63.9 kg (SD 9.0). From this total number of participants, two groups of 16 randomly selected participants were assessed to determine intra- and inter-tester reliability respectively. Extended field of view ultrasound images were obtained at three vertebral levels during rest and contraction in the side lying position for both the right and left sides of the trunk. RESULTS: Excellent intra-tester and inter-tester reliability was seen (ICC range of 0.972 to 0.984). The overall average percent standard error of the measurement for all measurements and locations was approximately 4%. The overall average minimal difference for the thickness measurement for the resting and contraction conditions combined were as follows: intratester 0.056 (0.014) cm and intertester 0.054 (0.017) cm, for area intratester 0.287 (0.086) cm2 and intertester 0.289 (0.101) cm2 and for length intratester 0.519 (0.097) cm and intertester 0.507 (0.085) cm. CONCLUSIONS: Extended field of view ultrasound imaging is an effective method of reliably capturing clear images of the TrA during rest and contraction. It provides an efficient mechanism for the analysis of muscle morphology by being able to measure the cross-sectional area, thickness, and length on one image. This methodology is recommended for studies investigating TrA function and training.


Assuntos
Músculos Abdominais , Contração Muscular , Músculos Abdominais/diagnóstico por imagem , Adulto , Humanos , Reprodutibilidade dos Testes , Tronco , Ultrassonografia , Adulto Jovem
18.
Entropy (Basel) ; 23(12)2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34945915

RESUMO

We introduce an index based on information theory to quantify the stationarity of a stochastic process. The index compares on the one hand the information contained in the increment at the time scale τ of the process at time t with, on the other hand, the extra information in the variable at time t that is not present at time t-τ. By varying the scale τ, the index can explore a full range of scales. We thus obtain a multi-scale quantity that is not restricted to the first two moments of the density distribution, nor to the covariance, but that probes the complete dependences in the process. This index indeed provides a measure of the regularity of the process at a given scale. Not only is this index able to indicate whether a realization of the process is stationary, but its evolution across scales also indicates how rough and non-stationary it is. We show how the index behaves for various synthetic processes proposed to model fluid turbulence, as well as on experimental fluid turbulence measurements.

19.
Mol Psychiatry ; 24(12): 1833-1843, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-29895894

RESUMO

Ketamine produces rapid and robust antidepressant effects in depressed patients within hours of administration, often when traditional antidepressant compounds have failed to alleviate symptoms. We hypothesized that ketamine would translocate Gαs from lipid rafts to non-raft microdomains, similarly to other antidepressants but with a distinct, abbreviated treatment duration. C6 glioma cells were treated with 10 µM ketamine for 15 min, which translocated Gαs from lipid raft domains to non-raft domains. Other NMDA antagonist did not translocate Gαs from lipid raft to non-raft domains. The ketamine-induced Gαs plasma membrane redistribution allows increased functional coupling of Gαs and adenylyl cyclase to increase intracellular cyclic adenosine monophosphate (cAMP). Moreover, increased intracellular cAMP increased phosphorylation of cAMP response element-binding protein (CREB), which, in turn, increased BDNF expression. The ketamine-induced increase in intracellular cAMP persisted after knocking out the NMDA receptor indicating an NMDA receptor-independent effect. Furthermore, 10 µM of the ketamine metabolite (2R,6R)-hydroxynorketamine (HNK) also induced Gαs redistribution and increased cAMP. These results reveal a novel antidepressant mechanism mediated by acute ketamine treatment that may contribute to ketamine's powerful antidepressant effect. They also suggest that the translocation of Gαs from lipid rafts is a reliable hallmark of antidepressant action that might be exploited for diagnosis or drug development.


Assuntos
Ketamina/farmacologia , Receptores de N-Metil-D-Aspartato/metabolismo , Antidepressivos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular , AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Depressão/tratamento farmacológico , Glioma/metabolismo , Humanos , Microdomínios da Membrana/efeitos dos fármacos
20.
J Surg Res ; 248: 38-44, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31841735

RESUMO

BACKGROUND: Endovascular abdominal aortic aneurysm repair (EVAR) allows us to intervene on patients otherwise considered poor candidates for open repair. Despite its importance in determining operative approach, no comparison has been made between the subjective "eyeball test" and an objective measurement of preoperative frailty for EVAR patients. MATERIALS AND METHODS: Patients undergoing elective EVAR were identified in the Vascular Quality Initiative (VQI) database (2003-2017). Patients were classified "unfit" based on a surgeon-reported variable. Frailty was defined using the VQI-derived Risk Analysis Index, which includes sex, age, BMI, renal failure, congestive heart failure, dyspnea, preoperative ambulation, and functional status. The association between fitness and/or frailty and adverse outcomes was determined by logistic regression. RESULTS: A total of 11,694 patients undergoing elective EVAR were included of which only 18.1% were "unfit," whereas 34.6% were "frail" and overall 43.6% "unfit or frail." Patients deemed "unfit" or "frail" had significantly increased odds of mortality, complications, and nonhome discharge (P < 0.001), and both frailty and unfitness generated negative predictive values for these outcomes greater than 93%. In adjusted logistic regression, the addition of objective frailty significantly improved model performance in predicting nonhome discharge (C-statistic 0.65 versus 0.71, P < 0.001) and complications (0.59 versus 0.61, P = 0.01), but similarly predicted mortality (0.74 versus 0.73, P = 0.99). CONCLUSIONS: Preoperative frailty assessment provides a useful objective measure of risk stratification as an adjunct to a physician's clinical intuition. The addition of frailty expands the pool of high-risk patients who are more likely to experience adverse postoperative events after elective EVAR and may benefit from uniquely tailored perioperative interventions.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Procedimentos Endovasculares/mortalidade , Fragilidade/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , América do Norte/epidemiologia , Estudos Retrospectivos , Medição de Risco
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