Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 588
Filtrar
1.
Genes Dev ; 31(20): 2067-2084, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-29138276

RESUMO

There is limited knowledge about the metabolic reprogramming induced by cancer therapies and how this contributes to therapeutic resistance. Here we show that although inhibition of PI3K-AKT-mTOR signaling markedly decreased glycolysis and restrained tumor growth, these signaling and metabolic restrictions triggered autophagy, which supplied the metabolites required for the maintenance of mitochondrial respiration and redox homeostasis. Specifically, we found that survival of cancer cells was critically dependent on phospholipase A2 (PLA2) to mobilize lysophospholipids and free fatty acids to sustain fatty acid oxidation and oxidative phosphorylation. Consistent with this, we observed significantly increased lipid droplets, with subsequent mobilization to mitochondria. These changes were abrogated in cells deficient for the essential autophagy gene ATG5 Accordingly, inhibition of PLA2 significantly decreased lipid droplets, decreased oxidative phosphorylation, and increased apoptosis. Together, these results describe how treatment-induced autophagy provides nutrients for cancer cell survival and identifies novel cotreatment strategies to override this survival advantage.


Assuntos
Antineoplásicos/farmacologia , Neoplasias/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose , Autofagia , Benzamidas/farmacologia , Linhagem Celular Tumoral , Respiração Celular/efeitos dos fármacos , Sobrevivência Celular , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Gotículas Lipídicas/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neoplasias/enzimologia , Neoplasias/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Fosfolipase A2/farmacologia , Fosfolipídeos/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirimidinas/farmacologia , Células Tumorais Cultivadas
2.
Physiol Genomics ; 56(3): 276-282, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38189116

RESUMO

Preeclampsia is a hypertensive disorder of pregnancy that affects ∼2%-5% of all pregnancies, contributes to 4 of the top 10 causes of pregnancy-related deaths, and remains a long-term risk factor for cardiometabolic diseases. Yet, little is still known about the molecular mechanisms that lead to this disease. There is evidence that some cases have a genetic cause. However, it is well appreciated that harmful factors in the environment, such as poor nutrition, stress, and toxins, may lead to epigenetics changes that can contribute to this disease. DNA methylation is one of the epigenetic modifications known to be fairly stable and impact gene expression. Using DNA from buccal swabs, we analyzed global DNA methylation among three groups of individuals: mothers who experienced 1) early-stage preeclampsia (<32 wk), 2) late-stage preeclampsia (>37 wk), or 3) no complications during their pregnancies, as well as the children from these three groups. We found significant differentially methylated regions (DMRs) between mothers who experienced preeclampsia compared with those with no complications adjacent or within genes that are important for placentation, embryonic development, cell adhesion, and inflammation (e.g., the cadherin pathway). A significant portion of DMR genes showed expression in tissues relevant to preeclampsia (i.e., the brain, heart, kidney, uterus, ovaries, and placenta). As this study was performed on DNA extracted from cheek swabs, this opens the way to future studies in different tissues, aimed at identifying possible biomarkers of risk and early detection, developing targeted interventions, and reducing the progression of this life-threatening disease.NEW & NOTEWORTHY Preeclampsia is a life-threatening hypertensive disorder, affecting 2%-5% of pregnancies, that remains poorly understood. This study analyzed DNA methylation from buccal swabs from mothers who experienced early and late-stage preeclampsia and those with uncomplicated pregnancies, along with their children. Differentially methylated regions were found near and within genes crucial for placental function, embryonic development, and inflammation. Many of these genes are expressed in preeclampsia-related tissues, offering hope for future biomarker development for this condition.


Assuntos
Hipertensão , Pré-Eclâmpsia , Criança , Gravidez , Feminino , Humanos , Placenta/metabolismo , Pré-Eclâmpsia/diagnóstico , Epigenoma , Metilação de DNA/genética , Hipertensão/genética , Biomarcadores/metabolismo , Inflamação/genética , DNA
3.
Clin Sci (Lond) ; 138(3): 117-134, 2024 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-38261523

RESUMO

In preterm neonates unable to obtain sufficient oral nutrition, intravenous lipid emulsion is life-saving. The contribution of post-conceptional level of maturation to pathology that some neonates experience is difficult to untangle from the global pathophysiology of premature birth. In the present study, we determined fetal physiological responses to intravenous lipid emulsion. Fetal sheep were given intravenous Intralipid 20® (n = 4 females, 7 males) or Lactated Ringer's Solution (n = 7 females, 4 males) between 125 ± 1 and 133 ± 1 d of gestation (term = 147 d). Manufacturer's recommendation for premature human infants was followed: 0.5-1 g/kg/d initial rate, increased by 0.5-1 to 3 g/kg/d. Hemodynamic parameters and arterial blood chemistry were measured, and organs were studied postmortem. Red blood cell lipidomics were analyzed by LC-MS. Intravenous Intralipid did not alter hemodynamic or most blood parameters. Compared with controls, Intralipid infusion increased final day plasma protein (P=0.004; 3.5 ± 0.3 vs. 3.9 ± 0.2 g/dL), albumin (P = 0.031; 2.2 ± 0.1 vs. 2.4 ± 0.2 g/dL), and bilirubin (P<0.001; conjugated: 0.2 ± 0.1 vs. 0.6 ± 0.2 mg/dL; unconjugated: 0.2 ± 0.1 vs. 1.1 ± 0.4 mg/dL). Circulating IGF-1 decreased following Intralipid infusion (P<0.001; 66 ± 24 vs. 46 ± 24 ng/mL). Compared with control Oil Red O liver stains (median score 0), Intralipid-infused fetuses scored 108 (P=0.0009). Lipidomic analysis revealed uptake and processing of infused lipids into red blood cells, increasing abundance of saturated fatty acids. The near-term fetal sheep tolerates intravenous lipid emulsion well, although lipid accumulates in the liver. Increased levels of unconjugated bilirubin may reflect increased red blood cell turnover or impaired placental clearance. Whether Intralipid is less well tolerated earlier in gestation remains to be determined.


Assuntos
Emulsões Gordurosas Intravenosas , Placenta , Recém-Nascido , Lactente , Masculino , Humanos , Feminino , Animais , Gravidez , Ovinos , Recém-Nascido Prematuro , Bilirrubina , Feto
4.
J Acoust Soc Am ; 155(2): 962-970, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38341729

RESUMO

Separating crowd responses from raw acoustic signals at sporting events is challenging because recordings contain complex combinations of acoustic sources, including crowd noise, music, individual voices, and public address (PA) systems. This paper presents a data-driven decomposition of recordings of 30 collegiate sporting events. The decomposition uses machine-learning methods to find three principal spectral shapes that separate various acoustic sources. First, the distributions of recorded one-half-second equivalent continuous sound levels from men's and women's basketball and volleyball games are analyzed with regard to crowd size and venue. Using 24 one-third-octave bands between 50 Hz and 10 kHz, spectrograms from each type of game are then analyzed. Based on principal component analysis, 87.5% of the spectral variation in the signals can be represented with three principal components, regardless of sport, venue, or crowd composition. Using the resulting three-dimensional component coefficient representation, a Gaussian mixture model clustering analysis finds nine different clusters. These clusters separate audibly distinct signals and represent various combinations of acoustic sources, including crowd noise, music, individual voices, and the PA system.

5.
J Acoust Soc Am ; 155(6): 3889-3899, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38888390

RESUMO

During NASA X-59 quiet supersonic aircraft community response tests, low-boom recordings will contain contaminating noise from instrumentation and ambient acoustical sources. This noise can inflate sonic boom perception metrics by several decibels. This paper discusses the development and comparison of robust lowpass filtering techniques for removing contaminating noise effects from low-boom recordings. The two filters are a time-domain Butterworth-magnitude filter and a frequency-domain Brick Wall filter. Both filters successfully reduce noise contamination in metric calculations for simulated data with real-world contaminating noise and demonstrate comparable performance to a modified ISO 11204 correction. The Brick Wall filter's success indicates that further attempts to match boom spectrum high-frequency roll-off beyond the contaminating noise floor are unnecessary and have marginal improvements on final metric calculations. Additionally, the Butterworth filter removes statistical correlation between ambient and boom levels for a real-world flight campaign, adding evidence that these techniques also work on other boom shapes. Overall, both filters can produce accurate metric calculations with only a few hundred hertz of positive signal-to-noise ratio. This work describes methods for accurate metric calculations in the presence of moderate noise contamination that should benefit X-59 and future low-boom supersonic aircraft testing.

6.
J Physiol ; 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37128962

RESUMO

Contraction of cardiomyocytes is initiated at subcellular elements called dyads, where L-type Ca2+ channels in t-tubules are located within close proximity to ryanodine receptors in the sarcoplasmic reticulum. While evidence from small rodents indicates that dyads are assembled gradually in the developing heart, it is unclear how this process occurs in large mammals. We presently examined dyadic formation in fetal and newborn sheep (Ovis aries), and the regulation of this process by fetal cardiac workload. By employing advanced imaging methods, we demonstrated that t-tubule growth and dyadic assembly proceed gradually during fetal sheep development, from 93 days of gestational age until birth (147 days). This process parallels progressive increases in fetal systolic blood pressure, and includes step-wise colocalization of L-type Ca2+ channels and the Na+ /Ca2+ exchanger with ryanodine receptors. These proteins are upregulated together with the dyadic anchor junctophilin-2 during development, alongside changes in the expression of amphiphysin-2 (BIN1) and its partner proteins myotubularin and dynamin-2. Increasing fetal systolic load by infusing plasma or occluding the post-ductal aorta accelerated t-tubule growth. Conversely, reducing fetal systolic load with infusion of enalaprilat, an angiotensin converting enzyme inhibitor, blunted t-tubule formation. Interestingly, altered t-tubule densities did not relate to changes in dyadic junctions, or marked changes in the expression of dyadic regulatory proteins, indicating that distinct signals are responsible for maturation of the sarcoplasmic reticulum. In conclusion, augmenting blood pressure and workload during normal fetal development critically promotes t-tubule growth, while additional signals contribute to dyadic assembly. KEY POINTS: T-tubule growth and dyadic assembly proceed gradually in cardiomyocytes during fetal sheep development, from 93 days of gestational age until the post-natal stage. Increasing fetal systolic load by infusing plasma or occluding the post-ductal aorta accelerated t-tubule growth and hypertrophy. In contrast, reducing fetal systolic load by enalaprilat infusion slowed t-tubule development and decreased cardiomyocyte size. Load-dependent modulation of t-tubule maturation was linked to altered expression patterns of the t-tubule regulatory proteins junctophilin-2 and amphiphysin-2 (BIN1) and its protein partners. Altered t-tubule densities did not influence dyadic formation, indicating that distinct signals are responsible for maturation of the sarcoplasmic reticulum.

7.
Physiol Rev ; 96(4): 1509-65, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27604528

RESUMO

Epidemiological evidence links an individual's susceptibility to chronic disease in adult life to events during their intrauterine phase of development. Biologically this should not be unexpected, for organ systems are at their most plastic when progenitor cells are proliferating and differentiating. Influences operating at this time can permanently affect their structure and functional capacity, and the activity of enzyme systems and endocrine axes. It is now appreciated that such effects lay the foundations for a diverse array of diseases that become manifest many years later, often in response to secondary environmental stressors. Fetal development is underpinned by the placenta, the organ that forms the interface between the fetus and its mother. All nutrients and oxygen reaching the fetus must pass through this organ. The placenta also has major endocrine functions, orchestrating maternal adaptations to pregnancy and mobilizing resources for fetal use. In addition, it acts as a selective barrier, creating a protective milieu by minimizing exposure of the fetus to maternal hormones, such as glucocorticoids, xenobiotics, pathogens, and parasites. The placenta shows a remarkable capacity to adapt to adverse environmental cues and lessen their impact on the fetus. However, if placental function is impaired, or its capacity to adapt is exceeded, then fetal development may be compromised. Here, we explore the complex relationships between the placental phenotype and developmental programming of chronic disease in the offspring. Ensuring optimal placentation offers a new approach to the prevention of disorders such as cardiovascular disease, diabetes, and obesity, which are reaching epidemic proportions.


Assuntos
Doença Crônica , Desenvolvimento Fetal/fisiologia , Troca Materno-Fetal/fisiologia , Placenta/fisiologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Animais , Feminino , Humanos , Placentação/fisiologia , Gravidez
8.
Am J Physiol Regul Integr Comp Physiol ; 325(6): R809-R819, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37867472

RESUMO

At birth, the fetus experiences a dramatic change in environment that is accompanied by a shift in myocardial fuel preference from lactate and glucose in fetal life to fatty acid oxidation after birth. We hypothesized that fatty acid metabolic machinery would mature during fetal life in preparation for this extreme metabolic transformation at birth. We quantified the pre- (94-day and 135-day gestation, term ∼147 days) and postnatal (5 ± 4 days postnatal) gene expression and protein levels for fatty acid transporters and enzymes in hearts from a precocial species, the sheep. Gene expression of fatty acid translocase (CD36), acyl-CoA synthetase long-chain 1 (ACSL1), carnitine palmitoyltransferase 1 (CPT1), hydroxy-acyl dehydrogenase (HADH), acetyl-CoA acetyltransferase (ACAT1), isocitrate dehydrogenase (IDH), and glycerol phosphate acyltransferase (GPAT) progressively increased through the perinatal period, whereas several genes [fatty acid transport protein 6 (FATP6), acyl-CoA synthetase long chain 3 (ACSL3), long-chain acyl-CoA dehydrogenase (LCAD), very long-chain acyl-CoA dehydrogenase (VLCAD), pyruvate dehydrogenase kinase (PDK4), phosphatidic acid phosphatase (PAP), and diacylglycerol acyltransferase (DGAT)] were stable in fetal hearts and had high expression after birth. Protein expression of CD36 and ACSL1 progressively increased throughout the perinatal period, whereas protein expression of carnitine palmitoyltransferase 1a (fetal isoform) (CPT1a) decreased and carnitine palmitoyltransferase 1b (adult isoform) (CPT1b) remained constitutively expressed. Using fluorescent-tagged long-chain fatty acids (BODIPY-C12), we demonstrated that fetal (125 ± 1 days gestation) cardiomyocytes produce 59% larger lipid droplets (P < 0.05) compared with newborn (8 ± 1 day) cardiomyocytes. These results provide novel insights into the perinatal maturation of cardiac fatty acid metabolism in a precocial species.NEW & NOTEWORTHY This study characterized the previously unknown expression patterns of genes that regulate the metabolism of free fatty acids in the perinatal sheep myocardium. This study shows that the prenatal myocardium prepares for the dramatic switch from carbohydrate metabolism to near complete reliance on free fatty acids postnatally. Fetal and neonatal cardiomyocytes also demonstrate differing lipid storage mechanisms where fetal cardiomyocytes form larger lipid droplets compared with newborn cardiomyocytes.


Assuntos
Carnitina O-Palmitoiltransferase , Ácidos Graxos não Esterificados , Gravidez , Feminino , Animais , Ovinos , Carnitina O-Palmitoiltransferase/metabolismo , Metabolismo dos Lipídeos , Acil-CoA Desidrogenase de Cadeia Longa/metabolismo , Ácidos Graxos/metabolismo , Coração Fetal/metabolismo , Isoformas de Proteínas/metabolismo , Ligases/metabolismo , Oxirredução
9.
Proc Natl Acad Sci U S A ; 117(22): 12452-12463, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32404426

RESUMO

Plastid isoprenoid-derived carotenoids serve essential roles in chloroplast development and photosynthesis. Although nearly all enzymes that participate in the biosynthesis of carotenoids in plants have been identified, the complement of auxiliary proteins that regulate synthesis, transport, sequestration, and degradation of these molecules and their isoprenoid precursors have not been fully described. To identify such proteins that are necessary for the optimal functioning of oxygenic photosynthesis, we screened a large collection of nonphotosynthetic (acetate-requiring) DNA insertional mutants of Chlamydomonas reinhardtii and isolated cpsfl1 The cpsfl1 mutant is extremely light-sensitive and susceptible to photoinhibition and photobleaching. The CPSFL1 gene encodes a CRAL-TRIO hydrophobic ligand-binding (Sec14) domain protein. Proteins containing this domain are limited to eukaryotes, but some may have been retargeted to function in organelles of endosymbiotic origin. The cpsfl1 mutant showed decreased accumulation of plastidial isoprenoid-derived pigments, especially carotenoids, and whole-cell focused ion-beam scanning-electron microscopy revealed a deficiency of carotenoid-rich chloroplast structures (e.g., eyespot and plastoglobules). The low carotenoid content resulted from impaired biosynthesis at a step prior to phytoene, the committed precursor to carotenoids. The CPSFL1 protein bound phytoene and ß-carotene when expressed in Escherichia coli and phosphatidic acid in vitro. We suggest that CPSFL1 is involved in the regulation of phytoene synthesis and carotenoid transport and thereby modulates carotenoid accumulation in the chloroplast.


Assuntos
Carotenoides/metabolismo , Chlamydomonas reinhardtii/crescimento & desenvolvimento , Cloroplastos/metabolismo , Proteínas de Plantas/metabolismo , Chlamydomonas reinhardtii/classificação , Chlamydomonas reinhardtii/genética , Chlamydomonas reinhardtii/metabolismo , Cloroplastos/química , Cloroplastos/genética , Fotossíntese , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Domínios Proteicos
10.
J Acoust Soc Am ; 153(4): 2262, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37092916

RESUMO

The nonlinear evolution of high-amplitude broadband noise is important to the psychoacoustic perception, usually annoyance, of high-speed jet noise. One method to characterize the nonlinear evolution of such noise is to consider a characteristic nonlinear waveform distortion length for the signal. A common length scale for this analysis is the shock formation distance of an initially sinusoidal signal. However, application of this length scale to broadband noise, even with the amplitude and source frequency replaced with characteristic values, may lead to underestimates of the overall nonlinear waveform distortion of the noise as indicated by the skewness of the time derivative of the acoustic pressure (or derivative skewness). This paper provides an alternative length scale derived directly from the evolution of the derivative skewness of Gaussian noise that may be more appropriate when analyzing the nonlinear evolution of broadband noise signals. This Gaussian-based length scale is shown to be a useful metric for its relative consistency and its physical interpretation. Various analytical predictions of the evolution of the derivative skewness for an ensemble of numerical simulations of noise propagation are used to highlight various aspects of this new length scale definition.

11.
J Acoust Soc Am ; 154(5): 2950-2958, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37943738

RESUMO

The National Transportation Noise Map (NTNM) gives time-averaged traffic noise across the continental United States (CONUS) using annual average daily traffic. However, traffic noise varies significantly with time. This paper outlines the development and utility of a traffic volume model which is part of VROOM, the Vehicular Reduced-Order Observation-based model, which, using hourly traffic volume data from thousands of traffic monitoring stations across CONUS, predicts nationwide hourly varying traffic source noise. Fourier analysis finds daily, weekly, and yearly temporal traffic volume cycles at individual traffic monitoring stations. Then, principal component analysis uses denoised Fourier spectra to find the most widespread cyclic traffic patterns. VROOM uses nine principal components to represent hourly traffic characteristics for any location, encapsulating daily, weekly, and yearly variation. The principal component coefficients are predicted across CONUS using location-specific features. Expected traffic volume model sound level errors-obtained by comparing predicted traffic counts to measured traffic counts-and expected NTNM-like errors, are presented. VROOM errors are typically within a couple of decibels, whereas NTNM-like errors are often inaccurate, even exceeding 10 decibels. This work details the first steps towards creation of a temporally and spectrally variable national transportation noise map.

12.
J Acoust Soc Am ; 154(3): 1921-1931, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37756578

RESUMO

The distinctive geometry and structural characteristics of Balinese gamelan gongs lead to the instrument's unique sound and musical style. This work presents high-resolution directivity measurements of two types of gamelan gongs to quantify and better understand their acoustic behavior. The measured instruments' structural modes clearly impact their far-field directivity patterns, with the number of directional lobes corresponding to the associated structural mode shapes. Many of the lowest modes produce dipole-like radiation, with the dipole moment determined by the positions of the nodal and antinodal regions. Higher modes exhibit more complex patterns with multiple lobes often correlated with the location and number of antinodal regions on the gong's edge. Directivity indices correspond to dipole radiation at low frequencies and quadrupole radiation at intermediate and higher frequencies. Symmetry analysis confirms that the gong's rim significantly impacts the resultant directivity.

13.
J Acoust Soc Am ; 154(2): 1168-1178, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37610283

RESUMO

Modeling environmental sound levels over continental scales is difficult due to the variety of geospatial environments. Moreover, current continental-scale models depend upon machine learning and therefore face additional challenges due to limited acoustic training data. In previous work, an ensemble of machine learning models was used to predict environmental sound levels in the contiguous United States using a training set composed of 51 geospatial layers (downselected from 120) and acoustic data from 496 geographic sites from Pedersen, Transtrum, Gee, Lympany, James, and Salton [JASA Express Lett. 1(12), 122401 (2021)]. In this paper, the downselection process, which is based on factors such as data quality and inter-feature correlations, is described in further detail. To investigate additional dimensionality reduction, four different feature selection methods are applied to the 51 layers. Leave-one-out median absolute deviation cross-validation errors suggest that the number of geospatial features can be reduced to 15 without significant degradation of the model's predictive error. However, ensemble predictions demonstrate that feature selection results are sensitive to variations in details of the problem formulation and, therefore, should elicit some skepticism. These results suggest that more sophisticated dimensionality reduction techniques are necessary for problems with limited training data and different training and testing distributions.

14.
J Allergy Clin Immunol ; 149(4): 1437-1444, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34619181

RESUMO

BACKGROUND: Exercise-induced laryngeal obstruction (EILO) causes exertional dyspnea and is important for its effect on quality of life, diagnostic confusion with exercise-induced asthma, and health care resource utilization. There is no validated patient-reported outcome measure specific to EILO. OBJECTIVE: We sought to develop, validate, and define a minimal clinically important difference for a patient-reported outcome measure to be used with adolescents and young adults with EILO. METHODS: A multidisciplinary group created a preliminary measure, modified by a 10-member participant focus group, with 20 items scored along a 5-point Likert scale. A subsequent cohort of participants recruited from a clinic, aged 12 to 21 years, with confirmed EILO by continuous laryngoscopy during exercise testing (1) completed the measure at 3 points in time over 28 days and (2) provided anchoring data in the form of a daily exercise log and categorical self-assessments of clinical improvement. Thirty additional participants without exertional dyspnea served as controls. RESULTS: Two hundred nineteen subjects with mild to severe EILO participated in the exploratory factor analysis, which identified 7 factors within the preliminary outcome measure. After a process of item reduction, a 12-item metric with a total score ranging from 0 to 48 was developed. Mean scores of patients with EILO and healthy controls at baseline were 28.8 ± 7.4 and 4.5 ± 7.4, respectively. A minimal clinically important difference of 6 was determined by comparison of index change with changes in categorical self-assessments of improvement. CONCLUSIONS: This is the first patient-reported outcome measure specifically designed for adolescents and young adults with EILO.


Assuntos
Obstrução das Vias Respiratórias , Asma Induzida por Exercício , Doenças da Laringe , Adolescente , Obstrução das Vias Respiratórias/diagnóstico , Obstrução das Vias Respiratórias/etiologia , Asma Induzida por Exercício/diagnóstico , Dispneia/diagnóstico , Dispneia/etiologia , Exercício Físico , Humanos , Qualidade de Vida , Adulto Jovem
15.
J Physiol ; 600(3): 655-670, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34802149

RESUMO

At birth, the mammalian myocardium switches from using carbohydrates as the primary energy substrate to free fatty acids as the primary fuel. Thus, a compromised switch could jeopardize normal heart function in the neonate. Placental embolization in sheep is a reliable model of intrauterine growth restriction (IUGR). It leads to suppression of both proliferation and terminal differentiation of cardiomyocytes. We hypothesized that the expression of genes regulating cardiac fatty acid metabolism would be similarly suppressed in IUGR, leading to compromised processing of lipids. Following 10 days of umbilicoplacental embolization in fetal sheep, IUGR fetuses had elevated circulating long-chain fatty acylcarnitines compared with controls (C14: CTRL 0.012 ± 0.005 nmol/ml vs. IUGR 0.018 ± 0.005 nmol/ml, P < 0.05; C18: CTRL 0.027 ± 0.009 nmol/mol vs. IUGR 0.043 ± 0.024 nmol/mol, P < 0.05, n = 12 control, n = 12 IUGR) indicative of impaired fatty acid metabolism. Uptake studies using fluorescently tagged BODIPY-C12-saturated free fatty acid in live, isolated cardiomyocytes showed lipid droplet area and number were not different between control and IUGR cells. mRNA levels of sarcolemmal fatty acid transporters (CD36, FATP6), acylation enzymes (ACSL1, ACSL3), mitochondrial transporter (CPT1), ß-oxidation enzymes (LCAD, HADH, ACAT1), tricarboxylic acid cycle enzyme (IDH), esterification enzymes (PAP, DGAT) and regulator of the lipid droplet formation (BSCL2) gene were all suppressed in IUGR myocardium (P < 0.05). However, protein levels for these regulatory genes were not different between groups. This discordance between mRNA and protein levels in the stressed myocardium suggests an adaptive protection of key myocardial enzymes under conditions of placental insufficiency. KEY POINTS: The fetal heart relies on carbohydrates in utero and must be prepared to metabolize fatty acids after birth but the effects of compromised fetal growth on the maturation of this metabolic system are unknown. Plasma fatty acylcarnitines are elevated in intrauterine growth-restricted (IUGR) fetuses compared with control fetuses, indicative of impaired fatty acid metabolism in fetal organs. Fatty acid uptake and storage are not different in IUGR cardiomyocytes compared with controls. mRNA levels of genes regulating fatty acid transporter and metabolic enzymes are suppressed in the IUGR myocardium compared with controls, while protein levels remain unchanged. Mismatches in gene and protein expression, and increased circulating fatty acylcarnitines may have long-term implications for offspring heart metabolism and adult health in IUGR individuals. This requires further investigation.


Assuntos
Retardo do Crescimento Fetal , Placenta , Animais , Carnitina/análogos & derivados , Ácidos Graxos , Feminino , Coração Fetal , Placenta/metabolismo , Gravidez , Ovinos
16.
Mol Microbiol ; 115(5): 930-941, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33434370

RESUMO

Trypanosoma brucei and other African trypanosomes are vector-borne parasites that cause substantial human suffering across sub-Saharan Africa. The T. brucei life cycle is punctuated by numerous developmental stages, each occurring in a specific environmental niche and characterized by a unique morphology, metabolism, surface protein coat, and gene expression profile. The environmental cues and signaling pathways that drive transitions between these stages remain incompletely understood. Recent studies have started to fill this gap in knowledge. Likewise, several new studies have expanded our understanding of parasite movement through specific tissues and the parasite's ability to alter movement in response to external cues. Life cycle stage differentiation and motility are intimately integrated phenomena, as parasites must be at the right place (i.e., within a specific environmental milieu) at the right time (i.e., when they are appropriately staged and preadapted for perceiving and responding to signals) in order to complete their life cycle. In this review, we highlight some of the recent work that has transformed our understanding of signaling events that control parasite differentiation and motility. Increased knowledge of T. brucei environmental sensing and signal transduction advances our understanding of parasite biology and may direct prospective chemotherapeutic and transmission blockade strategies that are critical to eradication efforts.


Assuntos
Trypanosoma brucei brucei/citologia , Trypanosoma brucei brucei/metabolismo , Tripanossomíase Africana/parasitologia , Animais , Diferenciação Celular , Humanos , Estágios do Ciclo de Vida , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Transdução de Sinais , Trypanosoma brucei brucei/genética
17.
FASEB J ; 35(3): e21423, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33605480

RESUMO

The degree that maternal glycemia affects placental metabolism of trophoblast cell types [cytotrophoblast (CTB) and syncytiotrophoblast (SCT)] in pregnant persons with gestational diabetes mellitus (GDM) is unknown. We tested the hypotheses that (a) hyperglycemia suppresses the metabolic rates of CTB and SCT; and (b) low placental metabolic activity from GDM placentas is due to decreased oxygen consumption of CTB. Trophoblast cells isolated from GDM and non-GDM term placentas were cultured for 8-hour (CTB) and following syncytialization at 72-hour (SCT) in 5 mM of glucose or 25 mM of glucose. Oxygen consumption rates, glycolysis, ATP levels, and lipid droplet morphometries were determined in CTB and SCT. In CTB from GDM placentas compared to control CTB: (a) oxidative phosphorylation was decreased by 44% (41.8 vs 74.2 pmol O2 /min/100 ng DNA, P = .002); (b) ATP content was 39% lower (1.1 × 10-7 vs 1.8 × 10-7  nM/ng DNA, P = .046); and (c) lipid droplets were two times larger (31.0 vs 14.4 µm2 /cell, P < .001) and 1.7 times more numerous (13.5 vs 7.9 lipid droplets/cell, P < .001). Hyperglycemia suppressed CTB glycolysis by 55%-60% (mean difference 20.4 [GDM, P = .008] and 15.4 [non-GDM, P = .029] mpH/min/100 ng DNA). GDM SCT was not metabolically different from non-GDM SCT. However, GDM SCT had significantly decreased expression of genes associated with differentiation including hCG, GCM1, and syncytin-1. We conclude that suppressed metabolic activity by the GDM placenta is attributable to metabolic dysfunction of CTB, not SCT. Critical placental hormone expression and secretion are decreased in GDM trophoblasts.


Assuntos
Diabetes Gestacional/metabolismo , Hiperglicemia/metabolismo , Lipídeos , Mitocôndrias/metabolismo , Diferenciação Celular , Feminino , Glucose/metabolismo , Glicólise/fisiologia , Humanos , Fosforilação Oxidativa/efeitos dos fármacos , Consumo de Oxigênio/fisiologia , Placenta/metabolismo , Gravidez , Trofoblastos/metabolismo
18.
Am J Obstet Gynecol ; 226(5): 607-632, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34968458

RESUMO

Most women in the United States do not meet the recommendations for healthful nutrition and weight before and during pregnancy. Women and providers often ask what a healthy diet for a pregnant woman should look like. The message should be "eat better, not more." This can be achieved by basing diet on a variety of nutrient-dense, whole foods, including fruits, vegetables, legumes, whole grains, healthy fats with omega-3 fatty acids that include nuts and seeds, and fish, in place of poorer quality highly processed foods. Such a diet embodies nutritional density and is less likely to be accompanied by excessive energy intake than the standard American diet consisting of increased intakes of processed foods, fatty red meat, and sweetened foods and beverages. Women who report "prudent" or "health-conscious" eating patterns before and/or during pregnancy may have fewer pregnancy complications and adverse child health outcomes. Comprehensive nutritional supplementation (multiple micronutrients plus balanced protein energy) among women with inadequate nutrition has been associated with improved birth outcomes, including decreased rates of low birthweight. A diet that severely restricts any macronutrient class should be avoided, specifically the ketogenic diet that lacks carbohydrates, the Paleo diet because of dairy restriction, and any diet characterized by excess saturated fats. User-friendly tools to facilitate a quick evaluation of dietary patterns with clear guidance on how to address dietary inadequacies and embedded support from trained healthcare providers are urgently needed. Recent evidence has shown that although excessive gestational weight gain predicts adverse perinatal outcomes among women with normal weight, the degree of prepregnancy obesity predicts adverse perinatal outcomes to a greater degree than gestational weight gain among women with obesity. Furthermore, low body mass index and insufficient gestational weight gain are associated with poor perinatal outcomes. Observational data have shown that first-trimester gain is the strongest predictor of adverse outcomes. Interventions beginning in early pregnancy or preconception are needed to prevent downstream complications for mothers and their children. For neonates, human milk provides personalized nutrition and is associated with short- and long-term health benefits for infants and mothers. Eating a healthy diet is a way for lactating mothers to support optimal health for themselves and their infants.


Assuntos
Ganho de Peso na Gestação , Dieta , Feminino , Humanos , Lactação , Masculino , Estado Nutricional , Obesidade , Gravidez , Verduras , Aumento de Peso
19.
Proc Natl Acad Sci U S A ; 116(33): 16631-16640, 2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31358635

RESUMO

Photosystem II (PSII) undergoes frequent photooxidative damage that, if not repaired, impairs photosynthetic activity and growth. How photosynthetic organisms protect vulnerable PSII intermediate complexes during de novo assembly and repair remains poorly understood. Here, we report the genetic and biochemical characterization of chloroplast-located rubredoxin 1 (RBD1), a PSII assembly factor containing a redox-active rubredoxin domain and a single C-terminal transmembrane α-helix (TMH) domain. RBD1 is an integral thylakoid membrane protein that is enriched in stroma lamellae fractions with the rubredoxin domain exposed on the stromal side. RBD1 also interacts with PSII intermediate complexes containing cytochrome b559 Complementation of the Chlamydomonas reinhardtii (hereafter Chlamydomonas) RBD1-deficient 2pac mutant with constructs encoding RBD1 protein truncations and site-directed mutations demonstrated that the TMH domain is essential for de novo PSII assembly, whereas the rubredoxin domain is involved in PSII repair. The rubredoxin domain exhibits a redox midpoint potential of +114 mV and is proficient in 1-electron transfers to a surrogate cytochrome c in vitro. Reduction of oxidized RBD1 is NADPH dependent and can be mediated by ferredoxin-NADP+ reductase (FNR) in vitro. We propose that RBD1 participates, together with the cytochrome b559, in the protection of PSII intermediate complexes from photooxidative damage during de novo assembly and repair. This role of RBD1 is consistent with its evolutionary conservation among photosynthetic organisms and the fact that it is essential in photosynthetic eukaryotes.


Assuntos
Membranas Intracelulares/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Rubredoxinas/metabolismo , Tilacoides/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Chlamydomonas reinhardtii/efeitos dos fármacos , Chlamydomonas reinhardtii/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/ultraestrutura , Ferro/farmacologia , Modelos Biológicos , Oxirredução , Domínios Proteicos , Rubredoxinas/química , Tilacoides/efeitos dos fármacos , Tilacoides/ultraestrutura
20.
J Acoust Soc Am ; 151(2): 752, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35232069

RESUMO

In 1971, the U.S. National Aeronautics and Space Administration (NASA) published a seminal report-NASA SP-8072-which compiled the results of the early supersonic jet noise studies and provided methods to calculate the noise produced from launch vehicles. Fifty years later and despite known limitations, SP-8072 remains the foundation for much of the launch vehicle noise modeling today. This article reviews what has been learned about the physics of noise generation and radiation from free and impinging rocket plumes since the completion of SP-8072. State-of-the-art methods for the mitigation of launch vehicle noise are also reviewed. A discussion of launch vehicle noise modeling, from empirical to numerical and including reduced-order models of supersonic jets, points to promising approaches that can describe rocket noise characteristics not captured by SP-8072.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA