Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 676
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
2.
Nat Chem Biol ; 20(3): 365-372, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37828400

RESUMO

Stimulator of interferon genes (STING) is a dimeric transmembrane adapter protein that plays a key role in the human innate immune response to infection and has been therapeutically exploited for its antitumor activity. The activation of STING requires its high-order oligomerization, which could be induced by binding of the endogenous ligand, cGAMP, to the cytosolic ligand-binding domain. Here we report the discovery through functional screens of a class of compounds, named NVS-STGs, that activate human STING. Our cryo-EM structures show that NVS-STG2 induces the high-order oligomerization of human STING by binding to a pocket between the transmembrane domains of the neighboring STING dimers, effectively acting as a molecular glue. Our functional assays showed that NVS-STG2 could elicit potent STING-mediated immune responses in cells and antitumor activities in animal models.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Membrana , Animais , Humanos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Bioensaio , Citosol , Imunidade Inata , Ligantes , Proteínas de Membrana/metabolismo
3.
Cell ; 144(5): 675-88, 2011 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-21376231

RESUMO

Toll-like receptors (TLRs) contribute to host resistance to microbial pathogens and can drive the evolution of virulence mechanisms. We have examined the relationship between host resistance and pathogen virulence using mice with a functional allele of the nramp-1 gene and lacking combinations of TLRs. Mice deficient in both TLR2 and TLR4 were highly susceptible to the intracellular bacterial pathogen Salmonella typhimurium, consistent with reduced innate immune function. However, mice lacking additional TLRs involved in S. typhimurium recognition were less susceptible to infection. In these TLR-deficient cells, bacteria failed to upregulate Salmonella pathogenicity island 2 (SPI-2) genes and did not form a replicative compartment. We demonstrate that TLR signaling enhances the rate of acidification of the Salmonella-containing phagosome, and inhibition of this acidification prevents SPI-2 induction. Our results indicate that S. typhimurium requires cues from the innate immune system to regulate virulence genes necessary for intracellular survival, growth, and systemic infection.


Assuntos
Interações Hospedeiro-Patógeno , Imunidade Inata , Salmonella typhimurium/imunologia , Salmonella typhimurium/patogenicidade , Transdução de Sinais , Receptores Toll-Like/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Linhagem Celular , Humanos , Macrófagos/imunologia , Macrófagos/microbiologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Receptores Toll-Like/imunologia
4.
Mol Cell ; 71(6): 879-881, 2018 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-30241604

RESUMO

Data on the perceptions of scientists suggest a moderate public distrust of scientist's motivations. Bettridge et al. suggest scientist's reluctance to engage the public on controversial ethical issues may be a contributing factor. The authors propose a Scientist's Oath to send a clear message to the public about our ideals.


Assuntos
Pessoal de Laboratório/ética , Códigos de Ética , Ética em Pesquisa , Humanos , Pesquisa , Confiança
5.
Genes Dev ; 32(15-16): 991-992, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30068701

RESUMO

Dysregulation of repetitive elements has been implicated in many cancers and other human diseases; however, the role of repetitive elements remains largely unexplored. In this issue of Genes & Development, Boulay and colleagues (pp. 1008-1019) explore the ability of GGAA repeats to act as alternative enhancers activated by EWS-FLI1 in Ewing sarcoma and contribute to tumorigenesis. Using CRISPR-mediated epigenome editing, repression of EWS-FLI1 targeted microsatellite enhancers halted aberrant gene expression and impaired the growth of Ewing sarcoma xenografts in vivo. The study reveals the regulatory capacity of repetitive elements in cancer and offers insight into therapeutic targets for Ewing sarcoma.


Assuntos
Regulação Neoplásica da Expressão Gênica , Sarcoma de Ewing/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Humanos , Repetições de Microssatélites , Proteínas de Fusão Oncogênica/genética
6.
J Neurosci ; 44(23)2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38637154

RESUMO

Cocaine use disorder is a significant public health issue without an effective pharmacological treatment. Successful treatments are hindered in part by an incomplete understanding of the molecular mechanisms that underlie long-lasting maladaptive plasticity and addiction-like behaviors. Here, we leverage a large RNA sequencing dataset to generate gene coexpression networks across six interconnected regions of the brain's reward circuitry from mice that underwent saline or cocaine self-administration. We identify phosphodiesterase 1b (Pde1b), a Ca2+/calmodulin-dependent enzyme that increases cAMP and cGMP hydrolysis, as a central hub gene within a nucleus accumbens (NAc) gene module that was bioinformatically associated with addiction-like behavior. Chronic cocaine exposure increases Pde1b expression in NAc D2 medium spiny neurons (MSNs) in male but not female mice. Viral-mediated Pde1b overexpression in NAc reduces cocaine self-administration in female rats but increases seeking in both sexes. In female mice, overexpressing Pde1b in D1 MSNs attenuates the locomotor response to cocaine, with the opposite effect in D2 MSNs. Overexpressing Pde1b in D1/D2 MSNs had no effect on the locomotor response to cocaine in male mice. At the electrophysiological level, Pde1b overexpression reduces sEPSC frequency in D1 MSNs and regulates the excitability of NAc MSNs. Lastly, Pde1b overexpression significantly reduced the number of differentially expressed genes (DEGs) in NAc following chronic cocaine, with discordant effects on gene transcription between sexes. Together, we identify novel gene modules across the brain's reward circuitry associated with addiction-like behavior and explore the role of Pde1b in regulating the molecular, cellular, and behavioral responses to cocaine.


Assuntos
Transtornos Relacionados ao Uso de Cocaína , Nucleotídeo Cíclico Fosfodiesterase do Tipo 1 , Redes Reguladoras de Genes , Camundongos Endogâmicos C57BL , Núcleo Accumbens , Caracteres Sexuais , Animais , Masculino , Feminino , Nucleotídeo Cíclico Fosfodiesterase do Tipo 1/genética , Nucleotídeo Cíclico Fosfodiesterase do Tipo 1/metabolismo , Camundongos , Transtornos Relacionados ao Uso de Cocaína/genética , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Redes Reguladoras de Genes/efeitos dos fármacos , Redes Reguladoras de Genes/genética , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Ratos , Cocaína/farmacologia , Recompensa
7.
Development ; 149(7)2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35311995

RESUMO

Embryonic aneuploidy is highly complex, often leading to developmental arrest, implantation failure or spontaneous miscarriage in both natural and assisted reproduction. Despite our knowledge of mitotic mis-segregation in somatic cells, the molecular pathways regulating chromosome fidelity during the error-prone cleavage-stage of mammalian embryogenesis remain largely undefined. Using bovine embryos and live-cell fluorescent imaging, we observed frequent micro-/multi-nucleation of mis-segregated chromosomes in initial mitotic divisions that underwent unilateral inheritance, re-fused with the primary nucleus or formed a chromatin bridge with neighboring cells. A correlation between a lack of syngamy, multipolar divisions and asymmetric genome partitioning was also revealed, and single-cell DNA-seq showed propagation of primarily non-reciprocal mitotic errors. Depletion of the mitotic checkpoint protein BUB1B (also known as BUBR1) resulted in similarly abnormal nuclear structures and cell divisions, as well as chaotic aneuploidy and dysregulation of the kinase-substrate network that mediates mitotic progression, all before zygotic genome activation. This demonstrates that embryonic micronuclei sustain multiple fates, provides an explanation for blastomeres with uniparental origins, and substantiates defective checkpoints and likely other maternally derived factors as major contributors to the karyotypic complexity afflicting mammalian preimplantation development.


Assuntos
Aneuploidia , Blastômeros , Animais , Bovinos , Cromossomos , Desenvolvimento Embrionário/genética , Cariotipagem , Mamíferos/genética , Mitose/genética
8.
Circ Res ; 132(7): 849-863, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-36876496

RESUMO

BACKGROUND: Removal of circulating plasma low-density lipoprotein cholesterol (LDL-C) by the liver relies on efficient endocytosis and intracellular vesicle trafficking. Increasing the availability of hepatic LDL receptors (LDLRs) remains a major clinical target for reducing LDL-C levels. Here, we describe a novel role for RNF130 (ring finger containing protein 130) in regulating plasma membrane availability of LDLR. METHODS: We performed a combination of gain-of-function and loss-of-function experiments to determine the effect of RNF130 on LDL-C and LDLR recycling. We overexpressed RNF130 and a nonfunctional mutant RNF130 in vivo and measured plasma LDL-C and hepatic LDLR protein levels. We performed in vitro ubiquitination assays and immunohistochemical staining to measure levels and cellular distribution of LDLR. We supplement these experiments with 3 separate in vivo models of RNF130 loss-of-function where we disrupted Rnf130 using either ASO (antisense oligonucleotides), germline deletion, or AAV CRISPR (adeno-associated virus clustered regularly interspaced short palindromic repeats) and measured hepatic LDLR and plasma LDL-C. RESULTS: We demonstrate that RNF130 is an E3 ubiquitin ligase that ubiquitinates LDLR resulting in redistribution of the receptor away from the plasma membrane. Overexpression of RNF130 decreases hepatic LDLR and increases plasma LDL-C levels. Further, in vitro ubiquitination assays demonstrate RNF130-dependent regulation of LDLR abundance at the plasma membrane. Finally, in vivo disruption of Rnf130 using ASO, germline deletion, or AAV CRISPR results in increased hepatic LDLR abundance and availability and decreased plasma LDL-C levels. CONCLUSIONS: Our studies identify RNF130 as a novel posttranslational regulator of LDL-C levels via modulation of LDLR availability, thus providing important insight into the complex regulation of hepatic LDLR protein levels.


Assuntos
Fígado , Receptores de LDL , LDL-Colesterol/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismo , Fígado/metabolismo , Proteínas de Transporte/metabolismo , Ubiquitinação , Lipoproteínas LDL/metabolismo
9.
Mol Cell ; 68(6): 1023-1037.e15, 2017 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-29272703

RESUMO

Heterochromatin is integral to cell identity maintenance by impeding the activation of genes for alternate cell fates. Heterochromatic regions are associated with histone 3 lysine 9 trimethylation (H3K9me3) or H3K27me3, but these modifications are also found in euchromatic regions that permit transcription. We discovered that resistance to sonication is a reliable indicator of the heterochromatin state, and we developed a biophysical method (gradient-seq) to discriminate subtypes of H3K9me3 and H3K27me3 domains in sonication-resistant heterochromatin (srHC) versus euchromatin. These classifications are more accurate than the histone marks alone in predicting transcriptional silence and resistance of alternate fate genes to activation during direct cell conversion. Our proteomics of H3K9me3-marked srHC and functional screens revealed diverse proteins, including RBMX and RBMXL1, that impede gene induction during cellular reprogramming. Isolation of srHC with gradient-seq provides a genome-wide map of chromatin structure, elucidating subtypes of repressed domains that are uniquely predictive of diverse other chromatin properties.


Assuntos
Biomarcadores/análise , Reprogramação Celular , Proteínas Cromossômicas não Histona/metabolismo , Genômica/métodos , Heterocromatina/genética , Heterocromatina/metabolismo , Proteômica/métodos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Células Cultivadas , Proteínas Cromossômicas não Histona/genética , Mapeamento Cromossômico , Fibroblastos/citologia , Fibroblastos/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Histonas/genética , Histonas/metabolismo , Humanos
10.
PLoS Genet ; 18(12): e1010548, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36574452

RESUMO

Variation in immune homeostasis, the state in which the immune system is maintained in the absence of stimulation, is highly variable across populations. This variation is attributed to both genetic and environmental factors. However, the identity and function of specific regulators have been difficult to identify in humans. We evaluated homeostatic antibody levels in the serum of the Collaborative Cross (CC) mouse genetic reference population. We found heritable variation in all antibody isotypes and subtypes measured. We identified 4 quantitative trait loci (QTL) associated with 3 IgG subtypes: IgG1, IgG2b, and IgG2c. While 3 of these QTL map to genome regions of known immunological significance (major histocompatibility and immunoglobulin heavy chain locus), Qih1 (associated with variation in IgG1) mapped to a novel locus on Chromosome 18. We further associated this locus with B cell proportions in the spleen and identify Methyl-CpG binding domain protein 1 under this locus as a novel regulator of homeostatic IgG1 levels in the serum and marginal zone B cells (MZB) in the spleen, consistent with a role in MZB differentiation to antibody secreting cells.


Assuntos
Camundongos de Cruzamento Colaborativo , Locos de Características Quantitativas , Camundongos , Humanos , Animais , Locos de Características Quantitativas/genética , Camundongos de Cruzamento Colaborativo/genética , Ativação Linfocitária , Imunoglobulina G/genética , Homeostase/genética , Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética
11.
J Neurosci ; 43(7): 1178-1190, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36623874

RESUMO

The accessory olfactory system (AOS) is critical for the development and expression of social behavior. The first dedicated circuit in the AOS, the accessory olfactory bulb (AOB), exhibits cellular and network plasticity in male and female mice after social experience. In the AOB, interneurons called internal granule cells (IGCs) express the plasticity-associated immediate-early gene Arc following intermale aggression or mating. Here, we sought to better understand how Arc-expressing IGCs shape AOB information processing and social behavior in the context of territorial aggression. We used "ArcTRAP" (Arc-CreERT2) transgenic mice to selectively and permanently label Arc-expressing IGCs following male-male resident-intruder interactions. Using whole-cell patch-clamp electrophysiology, we found that Arc-expressing IGCs display increased intrinsic excitability for several days after a single resident-intruder interaction. Further, we found that Arc-expressing IGCs maintain this increased excitability across repeated resident-intruder interactions, during which resident mice increase or "ramp" their aggression. We tested the hypothesis that Arc-expressing IGCs participate in ramping aggression. Using a combination of ArcTRAP mice and chemogenetics (Cre-dependent hM4D(Gi)-mCherry AAV injections), we found that disruption of Arc-expressing IGC activity during repeated resident-intruder interactions abolishes the ramping aggression exhibited by resident male mice. This work shows that Arc-expressing AOB IGC ensembles are activated by specific chemosensory environments, and play an integral role in the establishment and expression of sex-typical social behavior. These studies identify a population of plastic interneurons in an early chemosensory circuit that display physiological features consistent with simple memory formation, increasing our understanding of central chemosensory processing and mammalian social behavior.SIGNIFICANCE STATEMENT The accessory olfactory system plays a vital role in rodent chemosensory social behavior. We studied experience-dependent plasticity in the accessory olfactory bulb and found that internal granule cells expressing the immediate-early gene Arc after the resident-intruder paradigm increase their excitability for several days. We investigated the roles of these Arc-expressing internal granule cells on chemosensory social behavior by chemogenetically manipulating their excitability during repeated social interactions. We found that inhibiting these cells eliminated intermale aggressive ramping behavior. These studies identify a population of plastic interneurons in an early chemosensory circuit that display physiological features consistent with simple memory formation, increasing our understanding of central chemosensory processing and mammalian social behavior.


Assuntos
Interneurônios , Bulbo Olfatório , Camundongos , Masculino , Feminino , Animais , Bulbo Olfatório/fisiologia , Interneurônios/fisiologia , Neurônios , Comportamento Social , Agressão , Camundongos Transgênicos , Mamíferos
12.
J Virol ; 97(7): e0071523, 2023 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-37310228

RESUMO

Powassan virus (POWV) is an emerging tick-borne flavivirus that causes neuroinvasive diseases, including encephalitis, meningitis, and paralysis. Similar to other neuroinvasive flaviviruses, such as West Nile virus (WNV) and Japanese encephalitis virus (JEV), POWV disease presentation is heterogeneous, and the factors influencing disease outcome are not fully understood. We used Collaborative Cross (CC) mice to assess the impact of host genetic factors on POWV pathogenesis. We infected a panel of Oas1b-null CC lines with POWV and observed a range of susceptibility, indicating that host factors other than the well-characterized flavivirus restriction factor Oas1b modulate POWV pathogenesis in CC mice. Among the Oas1b-null CC lines, we identified multiple highly susceptible lines (0% survival), including CC071 and CC015, and two resistant lines, CC045 and CC057 (>75% survival). The susceptibility phenotypes generally were concordant among neuroinvasive flaviviruses, although we did identify one line, CC006, that was specifically resistant to JEV, suggesting that both pan-flavivirus and virus-specific mechanisms contribute to susceptibility phenotypes in CC mice. We found that POWV replication was restricted in bone marrow-derived macrophages from CC045 and CC057 mice, suggesting that resistance could result from cell-intrinsic restriction of viral replication. Although serum viral loads at 2 days postinfection were equivalent between resistant and susceptible CC lines, clearance of POWV from the serum was significantly enhanced in CC045 mice. Furthermore, CC045 mice had significantly lower viral loads in the brain at 7 days postinfection than did CC071 mice, suggesting that reduced central nervous system (CNS) infection contributes to the resistant phenotype of CC045 mice. IMPORTANCE Neuroinvasive flaviviruses, such as WNV, JEV, and POWV, are transmitted to humans by mosquitoes or ticks and can cause neurologic diseases, such as encephalitis, meningitis, and paralysis, and they can result in death or long-term sequelae. Although potentially severe, neuroinvasive disease is a rare outcome of flavivirus infection. The factors that determine whether someone develops severe disease after a flavivirus infection are not fully understood, but host genetic differences in polymorphic antiviral response genes likely contribute to the outcome of infection. We evaluated a panel of genetically diverse mice and identified lines with distinct outcomes following infection with POWV. We found that resistance to POWV pathogenesis corresponded to reduced viral replication in macrophages, more rapid clearance of virus in peripheral tissues, and reduced viral infection in the brain. These susceptible and resistant mouse lines will provide a system for investigating the pathogenic mechanisms of POWV and identifying polymorphic host genes that contribute to resistance.


Assuntos
Vírus da Encefalite Japonesa (Espécie) , Vírus da Encefalite Transmitidos por Carrapatos , Encefalite , Infecções por Flavivirus , Flavivirus , Vírus do Nilo Ocidental , Humanos , Camundongos , Animais , Flavivirus/genética , Camundongos de Cruzamento Colaborativo , Infecções por Flavivirus/genética , Vírus da Encefalite Transmitidos por Carrapatos/fisiologia , Vírus da Encefalite Japonesa (Espécie)/genética , Suscetibilidade a Doenças , Paralisia , 2',5'-Oligoadenilato Sintetase/genética
13.
Brain Behav Immun ; 122: 137-149, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39098439

RESUMO

Cocaine use disorder is a condition that leads to tremendous morbidity and mortality for which there are currently no FDA-approved pharmacotherapies. Previous research has demonstrated an important role for the resident population of bacteria of the large intestine, collectively dubbed the gut microbiome, in modulating brain and behavior in models of cocaine and other substance use disorders. Importantly, previous work has repeatedly shown that depletion of the gut microbiome leads to increased cocaine taking and seeking behaviors in multiple models. While the precise mechanism of these gut-brain signaling pathways in models of cocaine use is not fully clear, and intriguing possibility is through gut microbiome influences on innate immune system function. In this manuscript we identify the cytokine colony stimulating factor 2 (CSF2) as an immune factor that is increased by cocaine in a gut microbiome dependent manner. Peripherally injected CSF2 crosses the blood-brain barrier into the nucleus accumbens, a brain region central to behavioral responses to cocaine. Treatment with peripheral CSF2 reduces acute and sensitized locomotor responses to cocaine as well as reducing cocaine place preference at high doses. On a molecular level, we find that peripheral injections of CSF2 alter the transcriptional response to both acute and repeated cocaine in the nucleus accumbens. Finally, treatment of microbiome depleted mice with CSF2 reverses the behavioral effects of microbiome depletion on the conditioned place preference assay. Taken together, this work identifies an innate immune factor that represents a novel gut-brain signaling cascade in models of cocaine use and lays the foundations for further translational work targeting this pathway.


Assuntos
Transtornos Relacionados ao Uso de Cocaína , Cocaína , Microbioma Gastrointestinal , Animais , Masculino , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/fisiologia , Cocaína/farmacologia , Cocaína/administração & dosagem , Camundongos , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Transtornos Relacionados ao Uso de Cocaína/microbiologia , Camundongos Endogâmicos C57BL , Núcleo Accumbens/metabolismo , Núcleo Accumbens/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Locomoção/efeitos dos fármacos
14.
Exp Physiol ; 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39323005

RESUMO

Acute mountain sickness (AMS) causes serious illness for many individuals ascending to high altitude (HA), although preventable with appropriate acclimatisation. AMS is a clinical diagnosis, with symptom severity evaluated using the Lake Louise Score (LLS). Reliable methods of predicting which individuals will develop AMS have not been developed. This systematic review evaluates whether a predictive relationship exists between oxygen saturation and subsequent development of AMS. PubMed, PubMed Central, MEDLINE, Semantic Scholar, Cochrane Library, University of Birmingham Library and clinicaltrials.gov databases were systematically searched from inception to 15 June 2023. Human studies involving collection of peripheral blood oxygen saturation ( S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ ) from healthy lowlanders during ascent to HA that evaluated any relationship between S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ and AMS severity were considered for eligibility. Risk of bias was assessed using a modified Newcastle-Ottawa Tool for cohort studies (PROPSPERO CRD42023423542). Seven of 980 total identified studies were ultimately included for data extraction. These studies evaluated S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ and AMS (via LLS) in 1406 individuals during ascent to HA (3952-6300 m). Risk of bias was 'low' for six and 'moderate' for one of the included studies. Ascent profiles and S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ measurement methodology varied widely, as did the statistical methods for AMS prediction. Decreasing oxygen saturation measured with pulse oximetry during ascent shows a positive predictive relationship for individuals who develop AMS. Studies have high heterogeneity in ascent profile and oximetry measurement protocols. Further studies with homogeneous methodology are required to enable statistical analysis for more definitive evaluation of AMS predictability by pulse oximetry.

15.
Exp Physiol ; 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39277825

RESUMO

Acute mountain sickness (AMS) is a well-studied illness defined by clinical features (e.g., headache and nausea), as assessed by the Lake Louise score (LLS). Although obvious in its severe form, early stages of AMS are poorly defined and easily confused with common travel-related conditions. Measurement of hypoxaemia, the cause of AMS, should be helpful, yet to date its utility for identifying AMS susceptibility remains unclear. This study quantified altitude-induced hypoxaemia in individuals during an ascent to 4800 m to determine the utility of nocturnal pulse oximetry measurements for prediction of AMS. Eighteen individuals (36 ± 16 years of age) ascended to 4800 m over 12 days. Symptomology of AMS was assessed each morning via LLS criteria, with participants categorized as either AMS-positive (LLS ≥ 3 with headache) or AMS-negative. Overnight peripheral oxygen saturations (ov- S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_2}}}$ ) were recorded continuously (1 Hz) using portable oximeters. Derivatives of these recordings were compared between AMS-positive and -negative subjects (Mann-Whitney U-test). Exploratory analyses (Pearson's) were conducted to investigate relationships between overnight parameters and AMS severity. Overnight derivatives, including ov- S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_2}}}$ , heart rate/ov- S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_2}}}$ , variance, oxygen desaturation index, hypoxic burden and total sleep time at <80% S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_2}}}$ , all differed significantly between AMS-positive and -negative subjects (all P < 0.01), with cumulative/relative frequency plots highlighting these differences visually. Exploratory analysis revealed that ov- S p O 2 ${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_2}}}$ from 3850 m was correlated with peak LLS at 4800 m (r = 0.58-0.61). The findings highlight the potential for overnight oximetry to predict AMS susceptibility during ascent to high altitude. Further investigation is required to develop, evaluate and optimize predictive models to improve AMS management and prevention.

16.
Gynecol Oncol ; 180: 35-43, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38041901

RESUMO

OBJECTIVE: To define molecular features of ovarian cancer (OC) with germline pathogenic variants (PVs) in non-BRCA homologous recombination (HR) genes and analyze survival compared to BRCA1/2 and wildtype (WT) OC. METHODS: We included patients with OC undergoing tumor-normal sequencing (MSK-IMPACT) from 07/01/2015-12/31/2020, including germline assessment of BRCA1/2 and other HR genes ATM, BARD1, BRIP1, FANCA, FANCC, NBN, PALB2, RAD50, RAD51B, RAD51C, and RAD51D. Biallelic inactivation was assessed within tumors. Progression-free (PFS) and overall survival (OS) were calculated from pathologic diagnosis using the Kaplan-Meier method with left truncation. Whole-exome sequencing (WES) was performed in a subset. RESULTS: Of 882 patients with OC, 56 (6.3%) had germline PVs in non-BRCA HR genes; 95 (11%) had BRCA1-associated OC (58 germline, 37 somatic); and 59 (6.7%) had BRCA2-associated OC (40 germline, 19 somatic). High rates of biallelic alterations were observed among germline PVs in BRIP1 (11/13), PALB2 (3/4), RAD51B (3/4), RAD51C (3/4), and RAD51D (8/10). In cases with WES (27/35), there was higher tumor mutational burden (TMB; median 2.5 [1.1-6.0] vs. 1.2 mut/Mb [0.6-2.6]) and enrichment of HR-deficient (HRD) mutational signatures in tumors associated with germline PALB2 and RAD51B/C/D compared with BRIP1 PVs (p < 0.01). Other features of HRD, including telomeric-allelic imbalance (TAI) and large-scale state transitions (LSTs), were similar. Although there was heterogeneity in PFS/OS by gene group, only BRCA1/2-associated OC had improved survival compared to WT OC (p < 0.01). CONCLUSIONS: OCs associated with germline PVs in non-BRCA HR genes represent a heterogenous group, with PALB2 and RAD51B/C/D associated with an HRD phenotype.


Assuntos
Proteína BRCA1 , Neoplasias Ovarianas , Humanos , Feminino , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias Ovarianas/patologia , Mutação em Linhagem Germinativa , Recombinação Homóloga , Fenótipo , Células Germinativas/patologia , Predisposição Genética para Doença
17.
J Anim Ecol ; 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39340187

RESUMO

Polyphenisms occur when phenotypic plasticity produces morphologically distinct phenotypes from the same genotype. Plasticity is maintained through fitness trade-offs which are conferred to different phenotypes under specific environmental contexts. Predicting the impacts of contemporary climate change on phenotypic plasticity is critical for climate-sensitive animals like amphibians, but elucidating the selective pressures maintaining polyphenisms requires a framework to control for all mechanistic drivers of plasticity. Using a 32-year dataset documenting the larval and adult histories of 717 Arizona tiger salamanders (Ambystoma mavortium nebulosum), we determined how annual variation in climate and density dependence explained the maintenance of two distinct morphs (terrestrial metamorph vs. aquatic paedomorph) in a high-elevation polyphenism. The effects of climate and conspecific density on morph development were evaluated with piecewise structural equation models (SEM) to tease apart the direct and indirect pathways by which these two mechanisms affect phenotypic plasticity. Climate had a direct effect on morph outcome whereby longer growing seasons favoured metamorphic outcomes. Also, climate had indirect effects on morph outcome as mediated through density-dependent effects, such as long overwintering coldspells corresponding to high cannibal densities and light snowpacks corresponding to high larval densities, both of which promoted paedomorphic outcomes. Both climate and density dependence serve as important proxies for growth and resource limitation, which are important underlying drivers of the phenotypic plasticity in animal polyphenisms. Our findings motivate new studies to determine how contemporary climate change will alter the selective pressures maintaining phenotypic plasticity and polyphenisms.

18.
Ann Pharmacother ; 58(9): 877-885, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38247044

RESUMO

BACKGROUND: Phenobarbital may offer advantages over benzodiazepines for severe alcohol withdrawal syndrome (SAWS), but its impact on clinical outcomes has not been fully elucidated. OBJECTIVE: The purpose of this study was to determine the clinical impact of phenobarbital versus benzodiazepines for SAWS. METHODS: This retrospective cohort study compared phenobarbital to benzodiazepines for the management of SAWS for patients admitted to progressive or intensive care units (ICUs) between July 2018 and July 2022. Patients included had a history of delirium tremens (DT) or seizures, Clinical Institute Withdrawal Assessment of Alcohol-Revised (CIWA-Ar) >15, or Prediction of Alcohol Withdrawal Severity Scale (PAWSS) score ≥4. The primary outcome was hospital length of stay (LOS). Secondary outcomes included progressive or ICU LOS, incidence of adjunctive pharmacotherapy, and incidence/duration of mechanical ventilation. RESULTS: The final analysis included 126 phenobarbital and 98 benzodiazepine encounters. Patients treated with phenobarbital had shorter median hospital LOS versus those treated with benzodiazepines (2.8 vs 4.7 days; P < 0.0001); a finding corroborated by multivariable analysis. The phenobarbital group also had shorter median progressive/ICU LOS (0.7 vs 1.3 days; P < 0.0001), and lower incidence of dexmedetomidine (P < 0.0001) and antipsychotic initiation (P < 0.0001). Fewer patients in the phenobarbital group compared to the benzodiazepine group received new mechanical ventilation (P = 0.045), but median duration was similar (1.2 vs 1.6 days; P = 1.00). CONCLUSION AND RELEVANCE: Scheduled phenobarbital was associated with decreased hospital LOS compared to benzodiazepines for SAWS. This was the first study to compare outcomes of fixed-dose, nonoverlapping phenobarbital to benzodiazepines in patients with clearly defined SAWS and details a readily implementable protocol.


Assuntos
Benzodiazepinas , Tempo de Internação , Fenobarbital , Fenobarbital/uso terapêutico , Fenobarbital/administração & dosagem , Humanos , Benzodiazepinas/uso terapêutico , Benzodiazepinas/administração & dosagem , Masculino , Estudos Retrospectivos , Feminino , Pessoa de Meia-Idade , Tempo de Internação/estatística & dados numéricos , Adulto , Delirium por Abstinência Alcoólica/tratamento farmacológico , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Idoso , Unidades de Terapia Intensiva/estatística & dados numéricos , Hipnóticos e Sedativos/uso terapêutico , Hipnóticos e Sedativos/administração & dosagem , Índice de Gravidade de Doença , Estudos de Coortes
19.
Nature ; 559(7714): 356-362, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29973725

RESUMO

Arteries and veins are specified by antagonistic transcriptional programs. However, during development and regeneration, new arteries can arise from pre-existing veins through a poorly understood process of cell fate conversion. Here, using single-cell RNA sequencing and mouse genetics, we show that vein cells of the developing heart undergo an early cell fate switch to create a pre-artery population that subsequently builds coronary arteries. Vein cells underwent a gradual and simultaneous switch from venous to arterial fate before a subset of cells crossed a transcriptional threshold into the pre-artery state. Before the onset of coronary blood flow, pre-artery cells appeared in the immature vessel plexus, expressed mature artery markers, and decreased cell cycling. The vein-specifying transcription factor COUP-TF2 (also known as NR2F2) prevented plexus cells from overcoming the pre-artery threshold by inducing cell cycle genes. Thus, vein-derived coronary arteries are built by pre-artery cells that can differentiate independently of blood flow upon the release of inhibition mediated by COUP-TF2 and cell cycle factors.


Assuntos
Artérias/citologia , Vasos Coronários/citologia , Análise de Célula Única , Células-Tronco/citologia , Células-Tronco/metabolismo , Veias/citologia , Animais , Artérias/metabolismo , Fator II de Transcrição COUP/metabolismo , Ciclo Celular/genética , Diferenciação Celular , Linhagem da Célula , Vasos Coronários/metabolismo , Feminino , Masculino , Camundongos , Análise de Sequência de RNA , Veias/metabolismo
20.
Cereb Cortex ; 33(20): 10634-10648, 2023 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-37642601

RESUMO

Postnatal regulation of dendritic spine formation and refinement in cortical pyramidal neurons is critical for excitatory/inhibitory balance in neocortical networks. Recent studies have identified a selective spine pruning mechanism in the mouse prefrontal cortex mediated by class 3 Semaphorins and the L1 cell adhesion molecules, neuron-glia related cell adhesion molecule, Close Homolog of L1, and L1. L1 cell adhesion molecules bind Ankyrin B, an actin-spectrin adaptor encoded by Ankyrin2, a high-confidence gene for autism spectrum disorder. In a new inducible mouse model (Nex1Cre-ERT2: Ank2flox: RCE), Ankyrin2 deletion in early postnatal pyramidal neurons increased spine density on apical dendrites in prefrontal cortex layer 2/3 of homozygous and heterozygous Ankyrin2-deficient mice. In contrast, Ankyrin2 deletion in adulthood had no effect on spine density. Sema3F-induced spine pruning was impaired in cortical neuron cultures from Ankyrin B-null mice and was rescued by re-expression of the 220 kDa Ankyrin B isoform but not 440 kDa Ankyrin B. Ankyrin B bound to neuron-glia related CAM at a cytoplasmic domain motif (FIGQY1231), and mutation to FIGQH inhibited binding, impairing Sema3F-induced spine pruning in neuronal cultures. Identification of a novel function for Ankyrin B in dendritic spine regulation provides insight into cortical circuit development, as well as potential molecular deficiencies in autism spectrum disorder.


Assuntos
Transtorno do Espectro Autista , Espinhas Dendríticas , Camundongos , Animais , Espinhas Dendríticas/fisiologia , Anquirinas/genética , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Células Piramidais/fisiologia , Córtex Pré-Frontal/metabolismo , Camundongos Knockout
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA