Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
PLoS Biol ; 20(6): e3001684, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35727855

RESUMEN

The ability to detect and respond to acute oxygen (O2) shortages is indispensable to aerobic life. The molecular mechanisms and circuits underlying this capacity are poorly understood. Here, we characterize the behavioral responses of feeding Caenorhabditis elegans to approximately 1% O2. Acute hypoxia triggers a bout of turning maneuvers followed by a persistent switch to rapid forward movement as animals seek to avoid and escape hypoxia. While the behavioral responses to 1% O2 closely resemble those evoked by 21% O2, they have distinct molecular and circuit underpinnings. Disrupting phosphodiesterases (PDEs), specific G proteins, or BBSome function inhibits escape from 1% O2 due to increased cGMP signaling. A primary source of cGMP is GCY-28, the ortholog of the atrial natriuretic peptide (ANP) receptor. cGMP activates the protein kinase G EGL-4 and enhances neuroendocrine secretion to inhibit acute responses to 1% O2. Triggering a rise in cGMP optogenetically in multiple neurons, including AIA interneurons, rapidly and reversibly inhibits escape from 1% O2. Ca2+ imaging reveals that a 7% to 1% O2 stimulus evokes a Ca2+ decrease in several neurons. Defects in mitochondrial complex I (MCI) and mitochondrial complex I (MCIII), which lead to persistently high reactive oxygen species (ROS), abrogate acute hypoxia responses. In particular, repressing the expression of isp-1, which encodes the iron sulfur protein of MCIII, inhibits escape from 1% O2 without affecting responses to 21% O2. Both genetic and pharmacological up-regulation of mitochondrial ROS increase cGMP levels, which contribute to the reduced hypoxia responses. Our results implicate ROS and precise regulation of intracellular cGMP in the modulation of acute responses to hypoxia by C. elegans.


Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animales , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Calcio/metabolismo , GMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de GMP Cíclico/genética , Proteínas Quinasas Dependientes de GMP Cíclico/metabolismo , Hipoxia , Oxígeno/metabolismo , Especies Reactivas de Oxígeno/metabolismo
2.
BMC Infect Dis ; 24(1): 456, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38689220

RESUMEN

BACKGROUND: Both sleep-related breathing disorders (SRBDs) and HIV infection can interfere with normal sleep architecture, and also cause physical and psychological distress. We aimed to understand the differences in the obstructive patterns, sleep architecture, physical and psychological distress when compared between people living with HIV (PLWH) and matched the severity of SRBDs controls. METHODS: A comparative study using matched case-control design was conducted. Men with HIV infection (case group) were enrolled from 2016 to 2019. A control group with HIV seronegative men were matched for SRBDs severity, and were selected from sleep medicine center database for comparison. RESULTS: The mean age of the 108 men (including 54 cases and 54 matched controls) was 33.75 years. Central-apnea index (CI) was higher in the case group rather than matched controls (mean CI, 0.34 vs. 0.17, p = 0.049). PLWH had a lower mean percentage of stage 3 sleep (10.26% vs. 13.94%, p = 0.034) and a higher percentage of rapid eye movement sleep (20.59% vs. 17.85%, p = 0.011) compared to matched controls. Nocturnal enuresis and sleepiness causing traffic accidents were more frequent complaint in PLWH compared to controls. CONCLUSIONS: Early detected SRBDs and subtypes in PLWH to begin treatment for the underlying cause could reduce the risk of sleepiness-related traffic accidents.


Asunto(s)
Infecciones por VIH , Polisomnografía , Síndromes de la Apnea del Sueño , Humanos , Masculino , Estudios de Casos y Controles , Adulto , Infecciones por VIH/complicaciones , Infecciones por VIH/fisiopatología , Síndromes de la Apnea del Sueño/fisiopatología , Síndromes de la Apnea del Sueño/diagnóstico , Persona de Mediana Edad
3.
Sensors (Basel) ; 24(10)2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38793825

RESUMEN

The advancements of Internet of Things (IoT) technologies have enabled the implementation of smart and wearable sensors, which can be employed to provide older adults with affordable and accessible continuous biophysiological status monitoring. The quality of such monitoring data, however, is unsatisfactory due to excessive noise induced by various disturbances, such as motion artifacts. Existing methods take advantage of summary statistics, such as mean or median values, for denoising, without taking into account the biophysiological patterns embedded in data. In this research, a functional data analysis modeling method was proposed to enhance the data quality by learning individual subjects' diurnal heart rate (HR) patterns from historical data, which were further improved by fusing newly collected data. This proposed data-fusion approach was developed based on a Bayesian inference framework. Its effectiveness was demonstrated in an HR analysis from a prospective study involving older adults residing in assisted living or home settings. The results indicate that it is imperative to conduct personalized healthcare by estimating individualized HR patterns. Furthermore, the proposed calibration method provides a more accurate (smaller mean errors) and more precise (smaller error standard deviations) HR estimation than raw HR and conventional methods, such as the mean.


Asunto(s)
Teorema de Bayes , Frecuencia Cardíaca , Dispositivos Electrónicos Vestibles , Humanos , Frecuencia Cardíaca/fisiología , Masculino , Anciano , Femenino , Monitoreo Fisiológico/métodos , Monitoreo Fisiológico/instrumentación , Algoritmos , Estudios Prospectivos
4.
Circulation ; 146(1): 6-17, 2022 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-35656816

RESUMEN

BACKGROUND: The authors compare the effectiveness and safety of endovascular treatment (EVT) versus best medical management (BMM) in strokes attributable to acute basilar artery occlusion (BAO). METHODS: The present analysis was based on the ongoing, prospective, multicenter ATTENTION (Endovascular Treatment for Acute Basilar Artery Occlusion) trial registry in China. Our analytic sample comprised 2134 patients recruited at 48 sites between 2017 and 2021 and included 462 patients who received BMM and 1672 patients who received EVT. We performed an inversed probability of treatment weighting analysis. Qualifying patients had to present within 24 hours of estimated BAO. The primary clinical outcome was favorable functional outcome (modified Rankin Scale score, 0-3) at 90 days. We also performed a sensitivity analysis with the propensity score matching-based and the instrumental variable-based analysis. RESULTS: In our primary analysis using the inversed probability of treatment weighting-based analysis, there was a significantly higher rate of favorable outcome at 90 days among EVT patients compared with BMM-treated patients (adjusted relative risk, 1.42 [95% CI, 1.19-1.65]; absolute risk difference, 11.8% [95% CI, 6.9-16.7]). The mortality was significantly lower (adjusted relative risk, 0.78 [95% CI, 0.69-0.88]; absolute risk difference, -10.3% [95% CI, -15.8 to -4.9]) in patients undergoing EVT. Results were generally consistent across the secondary end points. Similar associations were seen in the propensity score matching-based and instrumental variable-based analysis. CONCLUSIONS: In this real-world study, EVT was associated with significantly better functional outcomes and survival at 90 days. Well-designed randomized studies comparing EVT with BMM in the acute BAO are needed. REGISTRATION: URL: www.chictr.org.cn; Unique identifier: ChiCTR2000041117.


Asunto(s)
Arteriopatías Oclusivas , Procedimientos Endovasculares , Accidente Cerebrovascular , Arteriopatías Oclusivas/terapia , Arteria Basilar , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/métodos , Humanos , Estudios Prospectivos , Sistema de Registros , Trombectomía/métodos , Resultado del Tratamiento
5.
Nature ; 542(7639): 43-48, 2017 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-28099418

RESUMEN

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.


Asunto(s)
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/citología , Caenorhabditis elegans/fisiología , Interleucina-17/metabolismo , Sensación/fisiología , Animales , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Caenorhabditis elegans/efectos de los fármacos , Células HEK293 , Humanos , Interneuronas/efectos de los fármacos , Interneuronas/metabolismo , Oxígeno/metabolismo , Oxígeno/farmacología , Receptores de Interleucina-17/metabolismo , Sensación/efectos de los fármacos , Transducción de Señal/efectos de los fármacos
6.
Hu Li Za Zhi ; 70(1): 60-69, 2023 Feb.
Artículo en Zh | MEDLINE | ID: mdl-36647311

RESUMEN

BACKGROUND: The continuous monitoring of body surface temperature has been proven to help detect potential fever events in hospitalized patients. However, the efficacy of using body surface temperature to detect fever in older adults remains unclear due to the relatively low and slower-to-change body surface temperature in this population. PURPOSE: This study was designed to investigate 1) the relationship between changes in body surface and routine tympanic temperatures, 2) the correlation between body surface temperature measurement frequency and detection of fever, and 3) the factors related to the incidence of fever in hospitalized older adults. METHODS: A prospective study was conducted on 33 hospitalized older adults aged 65 years or older who were suspected to have or diagnosed with an infection in an infectious disease and medical ward at a medical center in southern Taiwan from March to November 2020. Demographic, routine tympanic temperature, and heart rate data were collected by reviewing the participants' medical records. Body surface temperatures were monitored continuously using HEARThermo every 10 seconds until one of the following conditions were met: hospital discharge, no fever for three continuous days, and HEARThermo was removed. Descriptive analysis was used to compare the variations in body surface temperature and routine tympanic temperature measurements. Pearson correlation was used to analyze the correlation between different measurement frequencies and fever events. Finally, mixed effects logistic regression was used to analyze the factors significantly related to fever events. RESULTS: Seven hundred and twenty routine body temperature measurements were taken, with 209 (29.0%) fever events detected in 23 (69.7%) of the participants. The body surface temperatures were more closely correlated with tympanic temperatures during fever events than non-fever events (r = .260, p < .001). More fever events were detected using body surface temperature monitoring frequencies of every 10 seconds and every 1 minute. After controlling for demographic factors, the results of the mixed effect model indicate that body surface temperature and heart rate are significant factors related to fever events in hospitalized older adults (odds ratio, OR: 1.74, p < .001; OR: 1.11, p < .001). CONCLUSIONS / IMPLICATIONS FOR PRACTICE: The continuous monitoring of body surface temperature may improve the detection of fever events in hospitalized older adults. The application of wearable devices and cloud platforms may further facilitate the real-time assessment and care capabilities of nurses, thus reducing their workload and improving care quality.


Asunto(s)
Fiebre , Temperatura Cutánea , Humanos , Anciano , Estudios Prospectivos , Fiebre/diagnóstico , Temperatura Corporal/fisiología , Frecuencia Cardíaca , Termómetros
7.
Anticancer Drugs ; 33(1): e730-e733, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34387589

RESUMEN

EGFR and BRAF V600E mutations are both early driven and usually mutually exclusive. We report the case of a 59-year-old woman diagnosed with advanced lung adenocarcinoma harboring coexisting EGFR exon 18 G719A and BRAF V600E mutations. She experienced a long-term response to oral afatinib, with a progression-free survival rate of 33 months and an overall survival rate of 11 years. Lung adenocarcinoma with synchronous EGFR G719A and BRAF V600E mutations is rare and has not been previously reported. This case highlights the importance of an adequate response to afatinib and provides an optimal therapeutic option for such patients.


Asunto(s)
Adenocarcinoma del Pulmón/tratamiento farmacológico , Afatinib/uso terapéutico , Antineoplásicos/uso terapéutico , Neoplasias Pulmonares/tratamiento farmacológico , Adenocarcinoma del Pulmón/genética , Receptores ErbB/genética , Femenino , Humanos , Neoplasias Pulmonares/genética , Persona de Mediana Edad , Proteínas Proto-Oncogénicas B-raf/genética
8.
BMC Neurol ; 21(1): 237, 2021 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-34167477

RESUMEN

BACKGROUND: Studies have suggested that glycoprotein IIb/IIIa antagonists such as tirofiban are beneficial for patients with acute coronary syndromes. However, it is still uncertain about the efficacy and safety of tirofiban in patients with acute ischemic stroke (AIS). METHODS: In this prospective non-randomized study, 255 AIS patients were recruited from 4 comprehensive stroke centers in China between January, 2017 and May, 2018. Among them,169 patients were treated with aspirin plus clopidogrel and 86 patients were treated with tirofiban. The primary functional outcome was the distribution of the 90 days' modified Rankin Scale (mRS). The safety outcomes included the incidence of intracranial hemorrhage (ICH) at discharge and mortality at 3 months. RESULTS: In the propensity score matched cohort, tirofiban alone was noninferior to the dual antiplatelet with regard to the primary outcome (adjusted common odds ratio, 0.97; 95% confidence interval, 0.46 to 2.04; P = 0.93). Mortality at 90 days was 10% in the dual antiplatelet group and 8% in the tirofiban group (adjusted odds ratio 0.75; 95% CI 0.08 to 7.40, p = 0.81). There was no difference of the ICH rate between two groups (adjusted odds ratio 0.44; 95% CI 0.13 to 1.48, p = 0.18). In the inverse probability of treatment weighting-propensity score-adjusted cohort, similar differences were found for functional and safety outcomes. CONCLUSIONS: Our study suggested that tirofiban use appears to be safe as monotherapy in AIS treatment compared with common dual antiplatelet therapy, however, no improvement in functional outcomes was found. TRIAL REGISTRATION: Chinese clinical trial registry, ChiCTR2000034443 , 05/07/2020. Retrospectively registered.


Asunto(s)
Fibrinolíticos , Accidente Cerebrovascular Isquémico , Tirofibán , Aspirina/administración & dosificación , Aspirina/efectos adversos , Aspirina/uso terapéutico , China , Clopidogrel/administración & dosificación , Clopidogrel/efectos adversos , Clopidogrel/uso terapéutico , Fibrinolíticos/administración & dosificación , Fibrinolíticos/efectos adversos , Fibrinolíticos/uso terapéutico , Humanos , Hemorragias Intracraneales/inducido químicamente , Hemorragias Intracraneales/epidemiología , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Accidente Cerebrovascular Isquémico/mortalidad , Estudios Prospectivos , Tirofibán/administración & dosificación , Tirofibán/efectos adversos , Tirofibán/uso terapéutico
9.
J Clin Pharm Ther ; 46(1): 121-127, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32981056

RESUMEN

WHAT IS KNOWN AND OBJECTIVE: Low-dose ketamine can reduce the minimum alveolar concentration of sevoflurane necessary to block the adrenergic response (MACBAR ) in animals. However, the effects of low-dose ketamine on the sevoflurane MACBAR in patients undergoing laparoscopic surgery are unclear. The aim of this study was to investigate the effects of three different low doses of ketamine on the MACBAR of sevoflurane in patients undergoing laparoscopic cholecystectomy. METHODS: One hundred patients who underwent laparoscopic cholecystectomy were enrolled. After general anaesthesia induction and tracheal intubation, patients received sevoflurane anaesthesia in combination with a loading dose of saline followed by infusion or a loading dose of 0.5 mg/kg ketamine followed by a continuous infusion of 5 (K1 group), 10 (K2 group) and 20 µg/kg/min (K3 group). The target concentration of end-tidal sevoflurane was maintained for at least 20 minutes before carbon dioxide pneumoperitoneum stimulus. The MACBAR of sevoflurane in each group was determined by using an up-and-down sequential allocation technique. RESULTS AND DISCUSSION: Seventy-one patients completed the study. The values of MACBAR for sevoflurane were 5.3% in the K0 , 4.8% in K1 , 3.3% in K2 and 3.2% in K3 groups. The use of ketamine significantly reduced the MACBAR of sevoflurane compared to sevoflurane alone. The K2 and K3 groups showed significantly lower values of MACBAR than that in the K1 group. However, a higher dose of ketamine in the K3 group did not further reduce the sevoflurane MACBAR . The mean arterial blood pressure (MAP) values before pneumoperitoneum in the K2 and the K3 groups were significantly higher compared to those in the K0 and K1 groups. Compared with the values before pneumoperitoneum, the heart rate and MAP after pneumoperitoneum were significantly increased. Overall, the haemodynamics remained stable during the study period in all groups. WHAT IS NEW AND CONCLUSION: A loading dose of 0.5 mg/kg ketamine followed by a continuous infusion of 10.0 µg/kg/min led to a significant decrease in the MACBAR of sevoflurane in patients undergoing laparoscopic cholecystectomy.


Asunto(s)
Analgésicos Opioides/farmacología , Anestesia General , Anestésicos por Inhalación/farmacocinética , Colecistectomía Laparoscópica , Ketamina/farmacología , Sevoflurano/farmacocinética , Adolescente , Adulto , Anciano , Analgésicos Opioides/administración & dosificación , Anestésicos por Inhalación/sangre , Femenino , Hemodinámica , Humanos , Ketamina/administración & dosificación , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sevoflurano/sangre , Adulto Joven
10.
Proc Natl Acad Sci U S A ; 115(29): E6890-E6899, 2018 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-29959203

RESUMEN

Neuropeptides are ubiquitous modulators of behavior and physiology. They are packaged in specialized secretory organelles called dense core vesicles (DCVs) that are released upon neural stimulation. Unlike synaptic vesicles, which can be recycled and refilled close to release sites, DCVs must be replenished by de novo synthesis in the cell body. Here, we dissect DCV cell biology in vivo in a Caenorhabditis elegans sensory neuron whose tonic activity we can control using a natural stimulus. We express fluorescently tagged neuropeptides in the neuron and define parameters that describe their subcellular distribution. We measure these parameters at high and low neural activity in 187 mutants defective in proteins implicated in membrane traffic, neuroendocrine secretion, and neuronal or synaptic activity. Using unsupervised hierarchical clustering methods, we analyze these data and identify 62 groups of genes with similar mutant phenotypes. We explore the function of a subset of these groups. We recapitulate many previous findings, validating our paradigm. We uncover a large battery of proteins involved in recycling DCV membrane proteins, something hitherto poorly explored. We show that the unfolded protein response promotes DCV production, which may contribute to intertissue communication of stress. We also find evidence that different mechanisms of priming and exocytosis may operate at high and low neural activity. Our work provides a defined framework to study DCV biology at different neural activity levels.


Asunto(s)
Caenorhabditis elegans , Mutación , Neuropéptidos , Vesículas Secretoras , Células Receptoras Sensoriales/metabolismo , Vesículas Sinápticas , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Neuropéptidos/genética , Neuropéptidos/metabolismo , Vesículas Secretoras/genética , Vesículas Secretoras/metabolismo , Vesículas Sinápticas/genética , Vesículas Sinápticas/metabolismo
11.
BMC Neurosci ; 18(1): 69, 2017 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-28946859

RESUMEN

BACKGROUND: Alzheimer's disease is characterized by the accumulation of amyloid beta (Aß) and the formation of neurofibrillary tangles. Aß is the main constituent of senile plaques and is largely involved in neuronal death and neuroinflammation. Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) is one of the main transcriptional coactivator and has been related to many fields such as energy metabolism, cardiovascular disease, neurodegenerative disorders, and so on. RESULTS: Treatment with Aß1-42 reduced the expression of PGC-1α in both protein and RNA levels of neuroblastoma N2a cells. Aß1-42 induced a robust activation of cleaved caspase-3 while PGC-1α suppressed this activation and protected N2a cells from Aß-induced cell death. Overexpression of PGC-1α significantly reduced the level of main proinflammatory cytokines. In addition, PGC-1α inhibited the transportation of NF-κB p65 from cytoplasm to nucleus and IκBα degradation induced by Aß1-42. CONCLUSION: Our results have demonstrated that PGC-1α can protect neuroblastoma cells against Aß-induced neuronal death and neuroinflammation. Moreover, this neuroprotective effect of PGC-1α is regulated through NF-κB pathway. Taken together, our work provides evidence that PGC-1α could be beneficial in targeting Aß neurotoxicity.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/farmacología , Muerte Celular/fisiología , PPAR gamma/metabolismo , Enfermedad de Alzheimer/inducido químicamente , Péptidos beta-Amiloides/metabolismo , Animales , Metabolismo Energético/fisiología , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , FN-kappa B/metabolismo , Sustancias Protectoras/farmacología
12.
PLoS Genet ; 10(3): e1004082, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24603482

RESUMEN

Despite the importance of G-protein coupled receptors (GPCRs) their biogenesis is poorly understood. Like vertebrates, C. elegans uses a large family of GPCRs as chemoreceptors. A subset of these receptors, such as ODR-10, requires the odr-4 and odr-8 genes to be appropriately localized to sensory cilia. The odr-4 gene encodes a conserved tail-anchored transmembrane protein; the molecular identity of odr-8 is unknown. Here, we show that odr-8 encodes the C. elegans ortholog of Ufm1-specific protease 2 (UfSP2). UfSPs are cysteine proteases identified biochemically by their ability to liberate the ubiquitin-like modifier Ufm1 from its pro-form and protein conjugates. ODR-8/UfSP2 and ODR-4 are expressed in the same set of twelve chemosensory neurons, and physically interact at the ER membrane. ODR-4 also binds ODR-10, suggesting that an ODR-4/ODR-8 complex promotes GPCR folding, maturation, or export from the ER. The physical interaction between human ODR4 and UfSP2 suggests that this complex's role in GPCR biogenesis may be evolutionarily conserved. Unexpectedly, mutant versions of ODR-8/UfSP2 lacking catalytic residues required for protease activity can rescue all odr-8 mutant phenotypes tested. Moreover, deleting C. elegans ufm-1 does not alter chemoreceptor traffic to cilia, either in wild type or in odr-8 mutants. Thus, UfSP2 proteins have protease- and Ufm1-independent functions in GPCR biogenesis.


Asunto(s)
Proteínas de Caenorhabditis elegans/genética , Cisteína Endopeptidasas/genética , Proteínas/genética , Receptores Acoplados a Proteínas G/genética , Receptores Odorantes/genética , Animales , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Células Quimiorreceptoras/metabolismo , Cilios/genética , Cilios/metabolismo , Cisteína Endopeptidasas/metabolismo , Retículo Endoplásmico/genética , Retículo Endoplásmico/metabolismo , Células HeLa , Humanos , Ratones , Neuronas Receptoras Olfatorias/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores Odorantes/metabolismo , Olfato/genética
14.
Nucleic Acids Res ; 41(11): 5669-78, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23605039

RESUMEN

The conserved pre-mRNA retention and splicing (RES) complex, which in yeast consists of Bud13p, Snu17p and Pml1p, is thought to promote nuclear retention of unspliced pre-mRNAs and enhance splicing of a subset of transcripts. Here, we find that the absence of Bud13p or Snu17p causes greatly reduced levels of the modified nucleoside N(4)-acetylcytidine (ac(4)C) in tRNA and that a lack of Pml1p reduces ac(4)C levels at elevated temperatures. The ac(4)C nucleoside is normally found at position 12 in the tRNA species specific for serine and leucine. We show that the tRNA modification defect in RES-deficient cells is attributable to inefficient splicing of TAN1 pre-mRNA and the effects of reduced Tan1p levels on formation of ac(4)C. Analyses of cis-acting elements in TAN1 pre-mRNA showed that the intron sequence between the 5' splice site and branchpoint is necessary and sufficient to mediate RES dependency. We also show that in RES-deficient cells, the TAN1 pre-mRNA is targeted for degradation by the cytoplasmic nonsense-mediated mRNA decay pathway, indicating that poor nuclear retention may contribute to the tRNA modification defect. Our results demonstrate that TAN1 pre-mRNA processing has an unprecedented requirement for RES factors and that the complex controls the formation of ac(4)C in tRNA.


Asunto(s)
Regulación Fúngica de la Expresión Génica , Empalme del ARN , ARN de Transferencia/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas Portadoras/genética , Citidina/análogos & derivados , Citidina/metabolismo , Eliminación de Gen , Intrones , Mutación , Degradación de ARNm Mediada por Codón sin Sentido , Precursores del ARN/metabolismo , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Ribonucleoproteína Nuclear Pequeña U2/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
15.
Nucleic Acids Res ; 41(20): e193, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24013562

RESUMEN

Cas9 is an RNA-guided double-stranded DNA nuclease that participates in clustered regularly interspaced short palindromic repeats (CRISPR)-mediated adaptive immunity in prokaryotes. CRISPR-Cas9 has recently been used to generate insertion and deletion mutations in Caenorhabditis elegans, but not to create tailored changes (knock-ins). We show that the CRISPR-CRISPR-associated (Cas) system can be adapted for efficient and precise editing of the C. elegans genome. The targeted double-strand breaks generated by CRISPR are substrates for transgene-instructed gene conversion. This allows customized changes in the C. elegans genome by homologous recombination: sequences contained in the repair template (the transgene) are copied by gene conversion into the genome. The possibility to edit the C. elegans genome at selected locations will facilitate the systematic study of gene function in this widely used model organism.


Asunto(s)
Caenorhabditis elegans/genética , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Marcación de Gen/métodos , Reparación del ADN por Recombinación , Animales , Sistemas CRISPR-Cas , Desoxirribonucleasas/metabolismo , Conversión Génica , Ingeniería Genética/métodos , Genoma , Mutagénesis , Transgenes , ARN Pequeño no Traducido
16.
Biochem Biophys Res Commun ; 454(3): 441-5, 2014 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-25450681

RESUMEN

Familial dysautonomia (FD) is a recessive neurodegenerative genetic disease. FD is caused by a mutation in the IKBKAP gene resulting in a splicing defect and reduced levels of full length IKAP protein. IKAP homologues can be found in all eukaryotes and are part of a conserved six subunit protein complex, Elongator complex. Inactivation of any Elongator subunit gene in multicellular organisms cause a wide range of phenotypes, suggesting that Elongator has a pivotal role in several cellular processes. In yeast, there is convincing evidence that the main role of Elongator complex is in formation of modified wobble uridine nucleosides in tRNA and that their absence will influence translational efficiency. To date, no study has explored the possibility that FD patients display defects in formation of modified wobble uridine nucleosides as a consequence of reduced IKAP levels. In this study, we show that brain tissue and fibroblast cell lines from FD patients have reduced levels of the wobble uridine nucleoside 5-methoxycarbonylmethyl-2-thiouridine (mcm(5)s(2)U). Our findings indicate that FD could be caused by inefficient translation due to lower levels of wobble uridine nucleosides.


Asunto(s)
Encéfalo/patología , Disautonomía Familiar/patología , Fibroblastos/patología , ARN de Transferencia/química , Tiouridina/análogos & derivados , Encéfalo/metabolismo , Línea Celular , Disautonomía Familiar/metabolismo , Fibroblastos/metabolismo , Humanos , ARN de Transferencia/metabolismo , Tiouridina/análisis , Tiouridina/metabolismo
17.
PLoS Genet ; 7(9): e1002258, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21912530

RESUMEN

Elongator complex is required for formation of the side chains at position 5 of modified nucleosides 5-carbamoylmethyluridine (ncm5U34), 5-methoxycarbonylmethyluridine (mcm5U34), and 5-methoxycarbonylmethyl-2-thiouridine (mcm5s²U34) at wobble position in tRNA. These modified nucleosides are important for efficient decoding during translation. In a recent publication, Elongator complex was implicated to participate in telomeric gene silencing and DNA damage response by interacting with proliferating cell nuclear antigen (PCNA). Here we show that elevated levels of tRNA(Lys)(s²UUU), tRNA(Gln)(s²UUG), and tRNA(Glu)(s²UUC), which in a wild-type background contain the mcm5s²U nucleoside at position 34, suppress the defects in telomeric gene silencing and DNA damage response observed in the Elongator mutants. We also found that the reported differences in telomeric gene silencing and DNA damage response of various elp3 alleles correlated with the levels of modified nucleosides at U34. Defects in telomeric gene silencing and DNA damage response are also observed in strains with the tuc2Δ mutation, which abolish the formation of the 2-thio group of the mcm5s²U nucleoside in tRNA(Lys)(mcm5s²UUU), tRNA(Gln)(mcm5s²UUG), and tRNA(Glu)(mcm5s²UUC). These observations show that Elongator complex does not directly participate in telomeric gene silencing and DNA damage response, but rather that modified nucleosides at U34 are important for efficient expression of gene products involved in these processes. Consistent with this notion, we found that expression of Sir4, a silent information regulator required for assembly of silent chromatin at telomeres, was decreased in the elp3Δ mutants.


Asunto(s)
ARN de Transferencia de Glutamina/genética , ARN de Transferencia de Ácido Glutámico/genética , ARN de Transferencia de Lisina/genética , ARN de Transferencia/genética , Saccharomyces cerevisiae/genética , Proteínas Reguladoras de Información Silente de Saccharomyces cerevisiae/metabolismo , Cromatina/genética , Cromatina/metabolismo , Daño del ADN/genética , Regulación de la Expresión Génica , Silenciador del Gen , Humanos , Mutación , Antígeno Nuclear de Célula en Proliferación/genética , Antígeno Nuclear de Célula en Proliferación/metabolismo , Biosíntesis de Proteínas , ARN de Transferencia/metabolismo , Proteínas Reguladoras de Información Silente de Saccharomyces cerevisiae/genética , Telómero/genética
18.
Front Public Health ; 12: 1396184, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38983252

RESUMEN

Background: Previous studies have shown social activity is associated with reduced risk of health outcomes. However, among older people (≥65 years) who were socially inactive at baseline, limited study explored whether increased participation in social activity in later life was associated with reduced risk of health outcomes; therefore, using the data from the Chinese Longitudinal Healthy Longevity Survey, the study was performed. Methods: The study outcomes were 10-year all-cause mortality (sample number = 9,984) and 10-year heart diseases (sample number = 7,496). The exposure was the change of social activity frequency. Cox regression analysis was used for data analysis. Results: During the follow-up, there were 6,407 all-cause mortalities and 1,035 heart diseases, respectively. Kaplan-Meier analysis demonstrated that cumulative incidences of all-cause mortality were significantly lower in participants with changes into more frequent social activity (log-rank p < 0.001), while no significant difference was observed for heart diseases (log-rank p = 0.330). Compared with the subgroup who never participated in social activity at baseline, adjusted HRs of all-cause mortality were 0.79 (95% CI: 0.70-0.90, p < 0.001), 0.78 (95% CI: 0.63-0.96, p = 0.019), 0.74 (0.59-0.92, p = 0.006), and 0.70 (95% CI: 0.56-0.88, p = 0.002) for the subgroup of switching to sometimes, the subgroup of switching to once a month, the subgroup of switching to once a week, and the subgroup of switching to everyday, respectively. The corresponding HRs of heart diseases were 0.83 (95% CI: 0.65-1.08, p = 0.170), 0.82 (95% CI: 0.51-1.31, p = 0.412), 0.91 (0.58-1.42, p = 0.675) and 0.75 (95% CI: 0.47-1.20, p = 0.227), respectively. Stratified and sensitivity analyses revealed similar results. Conclusion: Among older people who never participated in social activity, increased participation in social activity in later life was associated with reduced risk of all-cause mortality, but was not associated with reduced risk of heart diseases.


Asunto(s)
Cardiopatías , Humanos , Masculino , Femenino , Anciano , Estudios Longitudinales , China/epidemiología , Cardiopatías/mortalidad , Anciano de 80 o más Años , Longevidad , Participación Social , Factores de Riesgo , Causas de Muerte , Mortalidad , Pueblos del Este de Asia
19.
J Biophotonics ; 17(1): e202300145, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37403428

RESUMEN

Photobiomodulation (PBM) therapy is an innovative treatment for neurological and psychological conditions. Complex IV of the mitochondrial respiratory chain can be stimulated by red light, which increases ATP synthesis. In addition, the ion channels' light absorption causes the release of Ca2+, which activates transcription factors and changes gene expression. Neuronal metabolism is improved by brain PBM therapy, which also promotes synaptogenesis and neurogenesis as well as anti-inflammatory. Its depression-treating potential is attracting attention for other conditions, including Parkinson's disease and dementia. Giving enough dosage for optimum stimulation using the transcranial PBM technique is challenging because of the rapidly increasing attenuation of light transmission in tissue. Different strategies like intranasal and intracranial light delivery systems have been proposed to overcome this restriction. The most recent preclinical and clinical data on the effectiveness of brain PBM therapy are studied in this review article.


Asunto(s)
Terapia por Luz de Baja Intensidad , Terapia por Luz de Baja Intensidad/métodos , Encéfalo , Neuronas , Neurogénesis
20.
Sci Total Environ ; 916: 170133, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38242467

RESUMEN

Flash droughts have gained considerable public attention due to the imminent threats they pose to food security, ecological safety, and human health. Currently, there has been little research exploring the projected changes in flash droughts and their association with compound meteorological extremes (CMEs). In this study, we applied the pentad-mean water deficit index to investigate the characteristics of flash droughts and their association with CMEs based on observational data and downscaled model simulations. Our analysis reveals an increasing trend in flash drought frequency in China based on historical observations and model simulations. Specifically, the proportion of flash drought frequency with a one-pentad onset time showed a consistent upward trend, with the southern parts of China experiencing a high average proportion during the historical period. Furthermore, the onset dates of the first (last) flash droughts during year are projected to shift earlier (later) in a warmer world. Flash droughts become significantly more frequent in the future, with a growth rate approximately 1.3 times higher in the high emission scenario than in the medium emission scenario. The frequency of flash droughts with a one-pentad onset time also exhibits a significant upward trend, indicating that flash droughts will occur more rapidly in the future. CMEs in southern regions of China were found to be more likely to trigger flash droughts in the historical period. The probability of CMEs triggering flash droughts is expected to increase with the magnitude of warming, particularly in the far-future under the high emissions scenario.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA