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1.
Sci Rep ; 14(1): 8427, 2024 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600145

RESUMO

Impaired physical function contributes to falls, fractures, and mortality among patients undergoing dialysis. Using a metabolomic approach, we identified metabolite alterations and effect size-based composite scores for constructs of impaired gait speed and grip strength. 108 participants incident to dialysis had targeted plasma metabolomics via liquid chromatography-mass spectrometry and physical function assessed (i.e., 4 m walk, handgrip strength). Physical function measures were categorized as above/ below median, with grip utilizing sex-based medians. To develop composite scores, metabolites were identified via Wilcoxon uncorrected p < 0.05 and effect size > 0.40. Receiver operating characteristic analyses tested whether scores differentiated between above/below function groups. Participants were 54% male, 77% Black and 53 ± 14 y with dialysis vintage of 101 ± 50 days. Median (IQR) grip strength was 35.5 (11.1) kg (males) and 20 (8.4) kg (females); median gait speed was 0.82 (0.34) m/s. Of 246 measured metabolites, composite scores were composed of 22 and 12 metabolites for grip strength and gait speed, respectively. Area under the curve for metabolite composite was 0.88 (gait) and 0.911 (grip). Composite scores of physical function performed better than clinical parameters alone in patients on dialysis. These results provide potential pathways for interventions and needed validation in an independent cohort.


Assuntos
Força da Mão , Diálise Renal , Feminino , Humanos , Masculino , Marcha , Caminhada , Velocidade de Caminhada
2.
RSC Med Chem ; 15(3): 1066-1071, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38516600

RESUMO

We have developed a novel chemical handle (PFI-E3H1) and a chemical probe (PFI-7) as ligands for the Gid4 subunit of the human E3 ligase CTLH degradation complex. Through an efficient initial hit-ID campaign, structure-based drug design (SBDD) and leveraging the sizeable Pfizer compound library, we identified a 500 nM ligand for this E3 ligase through file screening alone. Further exploration identified a vector that is tolerant to addition of a linker for future chimeric molecule design. The chemotype was subsequently optimized to sub-100 nM Gid4 binding affinity for a chemical probe. These novel tools, alongside the suitable negative control also identified, should enable the interrogation of this complex human E3 ligase macromolecular assembly.

3.
Am J Physiol Cell Physiol ; 326(2): C348-C361, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38047306

RESUMO

Exercise-like electrical pulse stimulation (EL-EPS) of myotubes mimics many key physiological changes induced by in vivo exercise. Besides enabling intracellular research, EL-EPS allows to study secreted factors, including muscle-specific microRNAs (myomiRs) carried in extracellular vesicles (EVs). These factors can participate in contraction-induced intercellular cross talk and may mediate the health benefits of exercise. However, the current knowledge of these responses, especially under variable nutritional conditions, is limited. We investigated the effects of EL-EPS on C2C12 myotube transcriptome in high- and low-glucose conditions by messenger RNA sequencing, while the expression of EV-carried miRNAs was analyzed by small RNA sequencing and RT-qPCR. We show that higher glucose availability augmented contraction-induced transcriptional changes and that the majority of the differentially expressed genes were upregulated. Furthermore, based on the pathway analyses, processes related to contractility and cytokine/inflammatory responses were upregulated. In addition, we report that EL-EPS increased packing of miR-1-3p into EVs independent of glucose availability. Together our findings suggest that in vitro EL-EPS is a usable tool not only to study contraction-induced intracellular mechanisms but also extracellular responses. The distinct transcriptional changes observed under variable nutritional conditions emphasize the importance of careful consideration of media composition in future exercise-mimicking studies.NEW & NOTEWORTHY The present study examined for the first time the effects of exercise-like electrical pulse stimulation administered under distinct nutritional conditions on 1) the transcriptome of the C2C12 myotubes and 2) their media containing extracellular vesicle-carried microRNAs. We report that higher glucose availability augmented transcriptional responses related especially to contractility and cytokine/inflammatory pathways. Agreeing with in vivo studies, we show that the packing of exercise-responsive miR-1-3p was increased in the extracellular vesicles in response to myotube contractions.


Assuntos
Vesículas Extracelulares , MicroRNAs , MicroRNAs/metabolismo , Contração Muscular/fisiologia , Glucose/farmacologia , Glucose/metabolismo , Transcriptoma , Fibras Musculares Esqueléticas/metabolismo , Citocinas/metabolismo , Vesículas Extracelulares/genética , Vesículas Extracelulares/metabolismo , Estimulação Elétrica
4.
JAMA Cardiol ; 8(11): 1050-1060, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37755728

RESUMO

Importance: Individually, cardiac, renal, and metabolic (CRM) conditions are common and leading causes of death, disability, and health care-associated costs. However, the frequency with which CRM conditions coexist has not been comprehensively characterized to date. Objective: To examine the prevalence and overlap of CRM conditions among US adults currently and over time. Design, Setting, and Participants: To establish prevalence of CRM conditions, nationally representative, serial cross-sectional data included in the January 2015 through March 2020 National Health and Nutrition Examination Survey (NHANES) were evaluated in this cohort study. To assess temporal trends in CRM overlap, NHANES data between 1999-2002 and 2015-2020 were compared. Data on 11 607 nonpregnant US adults (≥20 years) were included. Data analysis occurred between November 10, 2020, and November 23, 2022. Main Outcomes and Measures: Proportion of participants with CRM conditions, overall and stratified by age, defined as cardiovascular disease (CVD), chronic kidney disease (CKD), type 2 diabetes (T2D), or all 3. Results: From 2015 through March 2020, of 11 607 US adults included in the analysis (mean [SE] age, 48.5 [0.4] years; 51.0% women), 26.3% had at least 1 CRM condition, 8.0% had at least 2 CRM conditions, and 1.5% had 3 CRM conditions. Overall, CKD plus T2D was the most common CRM dyad (3.2%), followed by CVD plus T2D (1.7%) and CVD plus CKD (1.6%). Participants with higher CRM comorbidity burden were more likely to be older and male. Among participants aged 65 years or older, 33.6% had 1 CRM condition, 17.1% had 2 CRM conditions, and 5.0% had 3 CRM conditions. Within this subset, CKD plus T2D (7.3%) was most common, followed by CVD plus CKD (6.0%) and CVD plus T2D (3.8%). The CRM comorbidity burden was disproportionately high among participants reporting non-Hispanic Black race or ethnicity, unemployment, low socioeconomic status, and no high school degree. Among participants with 3 CRM conditions, nearly one-third (30.5%) did not report statin use, and only 4.8% and 3.0% used glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors, respectively. Between 1999 and 2020, the proportion of US adults with multiple CRM conditions increased significantly (from 5.3% to 8.0%; P < .001 for trend), as did the proportion having all 3 CRM conditions (0.7% to 1.5%; P < .001 for trend). Conclusions and Relevance: This cohort study found that CRM multimorbidity is increasingly common and undertreated among US adults, highlighting the importance of collaborative and comprehensive management strategies.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Insuficiência Renal Crônica , Adulto , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 2/epidemiologia , Inquéritos Nutricionais , Estudos de Coortes , Prevalência , Estudos Transversais , Doenças Cardiovasculares/epidemiologia , Insuficiência Renal Crônica/epidemiologia
5.
bioRxiv ; 2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36824890

RESUMO

A core challenge of olfactory neuroscience is to understand how neural representations of odor are generated and progressively transformed across different layers of the olfactory circuit into formats that support perception and behavior. The encoding of odor by odorant receptors in the input layer of the olfactory system reflects, at least in part, the chemical relationships between odor compounds. Neural representations of odor in higher order associative olfactory areas, generated by random feedforward networks, are expected to largely preserve these input odor relationships1-3. We evaluated these ideas by examining how odors are represented at different stages of processing in the olfactory circuit of the vinegar fly D. melanogaster. We found that representations of odor in the mushroom body (MB), a third-order associative olfactory area in the fly brain, are indeed structured and invariant across flies. However, the structure of MB representational space diverged significantly from what is expected in a randomly connected network. In addition, odor relationships encoded in the MB were better correlated with a metric of the similarity of their distribution across natural sources compared to their similarity with respect to chemical features, and the converse was true for odor relationships encoded in primary olfactory receptor neurons (ORNs). Comparison of odor coding at primary, secondary, and tertiary layers of the circuit revealed that odors were significantly regrouped with respect to their representational similarity across successive stages of olfactory processing, with the largest changes occurring in the MB. The non-linear reorganization of odor relationships in the MB indicates that unappreciated structure exists in the fly olfactory circuit, and this structure may facilitate the generalization of odors with respect to their co-occurence in natural sources.

6.
mBio ; 14(1): e0266322, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36715540

RESUMO

Numerous studies have described specific metabolites as biomarkers of severe liver diseases, but very few have measured gut microbiota (GM)-produced metabolites in fatty liver disease. We aimed at finding GM signatures and metabolite markers in plasma and feces related to high liver fat content. Based on imaging, we divided study participants into low (<5%, LF, n = 25) and high (>5%, HF, n = 39) liver fat groups. Fecal (LF n = 14, HF n = 25) and plasma (LF n = 11, HF n = 7) metabolomes of subsets of participants were studied using liquid chromatography/high resolution mass spectrometry. The GM were analyzed using 16S rRNA gene sequencing. Additionally, blood clinical variables and diet were studied. Dyslipidemia, higher liver enzymes and insulin resistance characterized the HF group. No major differences in diet were found between the groups. In the GM, the HF group had lower abundance of Bacteroides and Prevotellaceae NK3B31 group than the LF group after adjusting for metformin use or obesity. In feces, the HF group had higher levels of lysine and histidine degradation products, while 6-hydroxybetatestosterone (metabolized by CYP3A4) was low. Higher plasma levels of caffeine and its metabolites in the HF group indicate that the activity of hepatic CYP1A2 was lower than in the LF group. Our results suggest, that low fecal Prevotellaceae NK3B31 and Bacteroides abundance, and increased lysine and histidine degradation may serve as GM biomarkers of high liver fat. Altered plasma caffeine metabolites and lowered testosterone metabolism may specify decreased CYP activities, and their potential utility, as biomarkers of fatty liver disease. IMPORTANCE Because the high prevalence of nonalcoholic fatty liver disease sets diagnostic challenges to health care, identification of new biomarkers of the disease that in the future could have potential utility as diagnostic biomarkers of high liver fat content is important. Our results show that increased amino acid degradation products in the feces may be such biomarkers. In the blood, molecules that indicate defective hepatic metabolic enzyme activities were identified in individuals with high liver fat content.


Assuntos
Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica , Humanos , Lisina/metabolismo , Histidina/metabolismo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Cafeína/metabolismo , Fígado/metabolismo , Biomarcadores , Dieta Hiperlipídica
7.
Future Oncol ; 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36507931

RESUMO

Aim: Evaluate the relative efficacy of oral versus injectable azacitidine (AZA) maintenance therapy in acute myeloid leukemia (AML) after complete remission. Materials & methods: Systematic literature review identified QUAZAR AML-001, HOVON 97 AML, UK NCRI AML16 and QoLESS-AZA-AMLE (sensitivity analysis) trials. Network meta-analysis and matching-adjusted indirect comparisons assessed survival outcomes. Results: In the network meta-analysis, combining the HOVON 97 and UK NCRI trials, oral AZA (QUAZAR) was associated with significantly improved overall survival (OS) versus injectable AZA (hazard ratio: 0.744; 95% credible interval: 0.557-0.998). After matching-adjusted indirect comparisons, to address differences in patient characteristics across trials, OS improvements were maintained with oral versus injectable AZA (hazard ratio: 0.753; credible interval: 0.563-0.998). Conclusion: In AML, maintenance therapy with oral AZA was associated with improved OS versus injectable AZA.


Older people with acute myeloid leukemia (AML) may have remission with or without blood count recovery, after first-line chemotherapy; however, remission is short lived and overall survival is limited (7­12 months). Ongoing treatment (maintenance therapy) after response to initial chemotherapy may prolong remission. Maintenance therapy with azacitidine (AZA) given by injection beneath the skin (subcutaneous) or into a vein (intravenous) can extend disease-free survival compared with no further treatment and best supportive care. However, treatment with intravenous AZA may only extend overall survival in certain patients. ONUREG® is a novel formulation of AZA that can be taken by mouth (orally), remains in the body for longer periods and has the potential for significant clinical benefits compared with intravenous AZA. Presently, there are no studies directly comparing outcomes of maintenance therapy with oral and injectable AZA in older people with AML. In this analysis, we used an indirect treatment comparison method including four clinical trials to explore the survival benefit associated with ONUREG and injectable AZA when used as maintenance therapies after response to initial chemotherapy in older people with AML. Findings showed ONUREG significantly improved overall survival compared with injectable AZA, with an almost 26% reduction in the risk of death. These results suggest that maintenance therapy with ONUREG significantly improves overall survival compared with injectable AZA in older people with AML who may have remission with or without blood count recovery, after first-line chemotherapy.

8.
Vaccine ; 2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36503857

RESUMO

Gains in immunization coverage and delivery of primary health care service have stagnated in recent years. Remaining gaps in service coverage reflect multiple underlying reasons that may be amenable to improved health system design. Immunization systems and other primary health care services can be mutually supportive, for improved service delivery and for strengthening of Universal Health Coverage. Improvements require that dynamic and multi-faceted barriers and risks be addressed. These include workforce availability, quality data systems and use, leadership and management that is innovative, flexible, data driven and responsive to local needs. Concurrently, improvements in procurement, supply chain, logistics and delivery systems, and integrated monitoring of vaccine coverage and epidemiological disease surveillance with laboratory systems, and vaccine safety will be needed to support community engagement and drive prioritized actions and communication. Finally, political will and sustained resource commitment with transparent accountability mechanisms are required. The experience of the impact of COVID-19 pandemic on essential PHC services and the challenges of vaccine roll-out affords an opportunity to apply lessons learned in order to enhance vaccine services integrated with strong primary health care services and universal health coverage across the life course.

9.
JACC Case Rep ; 4(19): 1267-1273, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36406921

RESUMO

We report a patient with severe mitral annular calcification, mitral stenosis/regurgitation, hypertrophic obstructive cardiomyopathy, and subaortic membrane treated with valved left atrium-left ventricle conduit, septal myectomy, and membrane resection. Subsequent thrombosis of the conduit prompted successful valve-in- mitral annular calcification transcatheter mitral valve replacement and laceration of the anterior mitral leaflet to prevent outflow obstruction. (Level of Difficulty: Advanced.).

10.
Curr Biol ; 32(19): 4225-4239.e7, 2022 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-36070776

RESUMO

We describe a novel form of selective crosstalk between specific classes of primary olfactory receptor neurons (ORNs) in the Drosophila antennal lobe. Neurotransmitter release from ORNs is driven by two distinct sources of excitation: direct activity derived from the odorant receptor and stimulus-selective lateral signals originating from stereotypic subsets of other ORNs. Consequently, the level of presynaptic neurotransmitter release from an ORN can be significantly dissociated from its firing rate. Stimulus-selective lateral signaling results in the distributed representation of CO2-a behaviorally important environmental cue that directly excites a single ORN class-in multiple olfactory glomeruli, each with distinct response dynamics. CO2-sensitive glomeruli coupled to behavioral attraction respond preferentially to fast changes in CO2 concentration, whereas those coupled to behavioral aversion more closely follow absolute levels of CO2. Behavioral responses to CO2 also depend on the temporal structure of the stimulus: flies walk upwind to fluctuating, but not sustained, pulses of CO2. Stimulus-selective lateral signaling generalizes to additional odors and glomeruli, revealing a subnetwork of lateral interactions between ORNs that reshapes the spatial and temporal structure of odor representations in a stimulus-specific manner.


Assuntos
Neurônios Receptores Olfatórios , Receptores Odorantes , Animais , Dióxido de Carbono , Drosophila/fisiologia , Neurotransmissores , Odorantes , Condutos Olfatórios/fisiologia , Neurônios Receptores Olfatórios/fisiologia , Receptores Odorantes/fisiologia , Olfato/fisiologia
11.
Mol Genet Metab ; 136(4): 306-314, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35798654

RESUMO

Friedreich Ataxia (FA) is a rare and often fatal autosomal recessive disease in which a mitochondrial protein, frataxin (FXN), is severely reduced in all tissues. With loss of FXN, mitochondrial metabolism is severely disrupted. Multiple therapeutic approaches are in development, but a key limitation is the lack of biomarkers reflecting the activity of FXN in a timely fashion. We predicted this dysregulated metabolism would present a unique metabolite profile in blood of FA patients versus Controls (Con). Plasma from 10 FA and 11 age and sex matched Con subjects was analyzed by targeted mass spectrometry and untargeted NMR. This combined approach yielded quantitative measurements for 540 metabolites and found 59 unique metabolites (55 from MS and 4 from NMR) that were significantly different between cohorts. Correlation-based network analysis revealed several clusters of pathway related metabolites including a cluster associated with one­carbon (1C) metabolism composed of formate, sarcosine, hypoxanthine, and homocysteine. Receiver operator characteristics analyses demonstrated an excellent ability to discriminate between Con and FA with AUC values >0.95. These results are the first reported metabolomic analyses of human patients with FA. The metabolic perturbations, especially those related to 1C metabolism, may serve as a valuable biomarker panel of disease progression and response to therapy. The identification of dysregulated 1C metabolism may also inform the search for new therapeutic targets related to this pathway.


Assuntos
Ataxia de Friedreich , Biomarcadores/metabolismo , Carbono/metabolismo , Carbono/uso terapêutico , Ataxia de Friedreich/tratamento farmacológico , Ataxia de Friedreich/metabolismo , Humanos , Metabolômica , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo
12.
Eur J Nutr ; 61(5): 2357-2364, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35113194

RESUMO

PURPOSE: Some species of fish and seafood are high in trimethylamine N-oxide (TMAO), which accumulates in muscle where it protects against pressure and cold. Trimethylamine (TMA), the metabolic precursor to TMAO, is formed in fish during bacterial spoilage. Fish intake is promoted for its potential cardioprotective effects. However, numerous studies show TMAO has pro-atherothrombotic properties. Here, we determined the effects of fish or seafood consumption on circulating TMAO levels in participants with normal renal function. METHODS: TMAO and omega-3 fatty acid content were quantified across multiple different fish or seafood species by mass spectrometry. Healthy volunteers (n = 50) were recruited for three studies. Participants in the first study consented to 5 consecutive weekly blood draws and provided dietary recall for the 24 h preceding each draw. In the second study, TMAO levels were determined following defined low and high TMAO diets. Finally, participants consumed test meals containing shrimp, tuna, fish sticks, salmon or cod. TMAO levels were quantified by mass spectrometry in blood collected before and after dietary challenge. RESULTS: TMAO + TMA content varied widely across fish and seafood species. Consumption of fish sticks, cod, and to a lesser extent salmon led to significant increases in circulating TMAO levels. Within 1 day, circulating TMAO concentrations in all participants returned to baseline levels. CONCLUSIONS: We conclude that some fish and seafood contain high levels of TMAO, and may induce a transient elevation in TMAO levels in some individuals. Selection of low TMAO content fish is prudent for subjects with elevated TMAO, cardiovascular disease or impaired renal function.


Assuntos
Peixes , Alimentos Marinhos , Animais , Bactérias , Dieta , Ácidos Graxos Ômega-3 , Peixes/microbiologia , Humanos , Espectrometria de Massas , Metilaminas/sangue , Alimentos Marinhos/microbiologia
13.
Front Cell Dev Biol ; 9: 720096, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34621740

RESUMO

Background: Cancer cachexia is a severe metabolic disorder characterized by progressive weight loss along with a dramatic loss in skeletal muscle and adipose tissue. Like cancer, cachexia progresses in stages starting with pre-cachexia to cachexia and finally to refractory cachexia. In the refractory stage, patients are no longer responsive to therapy and management of weight loss is no longer possible. It is therefore critical to detect cachexia as early as possible. In this study we applied a metabolomics approach to search for early biomarkers of cachexia. Methods: Multi-platform metabolomics analyses were applied to the murine Colon-26 (C26) model of cachexia. Tumor bearing mice (n = 5) were sacrificed every other day over the 14-day time course and control mice (n = 5) were sacrificed every fourth day starting at day 2. Linear regression modeling of the data yielded metabolic trajectories that were compared with the trajectories of body weight and skeletal muscle loss to look for early biomarkers of cachexia. Results: Weight loss in the tumor-bearing mice became significant at day 9 as did the loss of tibialis muscle. The loss of muscle in the gastrocnemius and quadriceps was significant at day 7. Reductions in amino acids were among the earliest metabolic biomarkers of cachexia. The earliest change was in methionine at day 4. Significant alterations in acylcarnitines and lipoproteins were also detected several days prior to weight loss. Conclusion: The results of this study demonstrate that metabolic alterations appear well in advance of observable weight loss. The earliest and most significant alterations were found in amino acids and lipoproteins. Validation of these results in other models of cachexia and in clinical studies will pave the way for a clinical diagnostic panel for the early detection of cachexia. Such a panel would provide a tremendous advance in cachectic patient management and in the design of clinical trials for new therapeutic interventions.

14.
ACS Med Chem Lett ; 12(10): 1585-1588, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34676040

RESUMO

The ring strain present in azetidines can lead to undesired stability issues. Herein, we described a series of N-substituted azetidines which undergo an acid-mediated intramolecular ring-opening decomposition via nucleophilic attack of a pendant amide group. Studies were conducted to understand the decomposition mechanism enabling the design of stable analogues.

15.
Metabolomics ; 17(10): 95, 2021 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-34601638

RESUMO

BACKGROUND: Children and young adults with single ventricle (SV) heart disease frequently develop heart failure (HF) that is intractable and difficult to treat. Our understanding of the molecular and biochemical reasons underlying this is imperfect. Thus, there is an urgent need for biomarkers that predict outcome and provide a rational basis for treatment, and advance our understanding of the basis of HF. OBJECTIVE: We sought to determine if a metabolomic approach would provide biochemical signatures of HF in SV children and young adults. If significant, these analytes might serve as biomarkers to predict outcome and inform on the biological mechanism(s) of HF. METHODS: We applied a multi-platform metabolomics approach composed of mass spectrometry (MS) and nuclear magnetic resonance (NMR) which yielded 495 and 26 metabolite measurements respectively. The plasma samples came from a cross-sectional set of young SV subjects, ages 2-19 years with ten control (Con) subjects and 16 SV subjects. Of the SV subjects, nine were diagnosed as congestive HF (SVHF), and 7 were not in HF. Metabolomic data were correlated with clinical status to determine if there was a signature associated with HF. RESULTS: There were no differences in age, height, weight or sex between the 3 cohorts. However, statistical analysis of the metabolomic profiles using ANOVA revealed 44 metabolites with significant differences between cohorts including 41 profiled by MS and 3 by NMR. These metabolites included acylcarnitines, amino acids, and bile acids, which distinguished Con from all SV subjects. Furthermore, metabolite profiles could distinguish between SV and SVHF subjects. CONCLUSION: These are the first data to demonstrate a clear metabolomic signature associated with HF in children and young adults with SV. Larger studies are warranted to determine if these findings are predictive of progression to HF in time to provide intervention.


Assuntos
Insuficiência Cardíaca , Adolescente , Adulto , Biomarcadores , Criança , Pré-Escolar , Estudos Transversais , Insuficiência Cardíaca/diagnóstico , Humanos , Metaboloma , Metabolômica , Adulto Jovem
17.
Metabolism ; 123: 154864, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34400216

RESUMO

BACKGROUND: Skeletal muscle atrophy, whether caused by chronic disease, acute critical illness, disuse or aging, is characterized by tissue-specific decrease in oxidative capacity and broad alterations in metabolism that contribute to functional decline. However, the underlying mechanisms responsible for these metabolic changes are largely unknown. One of the most highly upregulated genes in atrophic muscle is AMP deaminase 3 (AMPD3: AMP → IMP + NH3), which controls the content of intracellular adenine nucleotides (AdN; ATP + ADP + AMP). Given the central role of AdN in signaling mitochondrial gene expression and directly regulating metabolism, we hypothesized that overexpressing AMPD3 in muscle cells would be sufficient to alter their metabolic phenotype similar to that of atrophic muscle. METHODS: AMPD3 and GFP (control) were overexpressed in mouse tibialis anterior (TA) muscles via plasmid electroporation and in C2C12 myotubes using adenovirus vectors. TA muscles were excised one week later, and AdN were quantified by UPLC. In myotubes, targeted measures of AdN, AMPK/PGC-1α/mitochondrial protein synthesis rates, unbiased metabolomics, and transcriptomics by RNA sequencing were measured after 24 h of AMPD3 overexpression. Media metabolites were measured as an indicator of net metabolic flux. At 48 h, the AMPK/PGC-1α/mitochondrial protein synthesis rates, and myotube respiratory function/capacity were measured. RESULTS: TA muscles overexpressing AMPD3 had significantly less ATP than contralateral controls (-25%). In myotubes, increasing AMPD3 expression for 24 h was sufficient to significantly decrease ATP concentrations (-16%), increase IMP, and increase efflux of IMP catabolites into the culture media, without decreasing the ATP/ADP or ATP/AMP ratios. When myotubes were treated with dinitrophenol (mitochondrial uncoupler), AMPD3 overexpression blunted decreases in ATP/ADP and ATP/AMP ratios but exacerbated AdN degradation. As such, pAMPK/AMPK, pACC/ACC, and phosphorylation of AMPK substrates, were unchanged by AMPD3 at this timepoint. AMPD3 significantly altered 191 out of 639 detected intracellular metabolites, but only 30 transcripts, none of which encoded metabolic enzymes. The most altered metabolites were those within purine nucleotide, BCAA, glycolysis, and ceramide metabolic pathways. After 48 h, AMPD3 overexpression significantly reduced pAMPK/AMPK (-24%), phosphorylation of AMPK substrates (-14%), and PGC-1α protein (-22%). Moreover, AMPD3 significantly reduced myotube mitochondrial protein synthesis rates (-55%), basal ATP synthase-dependent (-13%), and maximal uncoupled oxygen consumption (-15%). CONCLUSIONS: Increased expression of AMPD3 significantly decreased mitochondrial protein synthesis rates and broadly altered cellular metabolites in a manner similar to that of atrophic muscle. Importantly, the changes in metabolites occurred prior to reductions in AMPK signaling, gene expression, and mitochondrial protein synthesis, suggesting metabolism is not dependent on reductions in oxidative capacity, but may be consequence of increased AMP deamination. Therefore, AMP deamination in skeletal muscle may be a mechanism that alters the metabolic phenotype of skeletal muscle during atrophy and could be a target to improve muscle function during muscle wasting.


Assuntos
Monofosfato de Adenosina/metabolismo , Músculo Esquelético/metabolismo , Atrofia Muscular , AMP Desaminase/genética , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Desaminação , Camundongos , Fenótipo
18.
Am J Physiol Endocrinol Metab ; 321(2): E229-E245, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34181491

RESUMO

The application of exercise-like electrical pulse simulation (EL-EPS) has become a widely used exercise mimetic in vitro. EL-EPS produces similar physiological responses as in vivo exercise, while less is known about the detailed metabolic effects. Routinely, the C2C12 myotubes are cultured in high-glucose medium (4.5 g/L), which may alter EL-EPS responses. In this study, we evaluate the metabolic effects of EL-EPS under the high- and low-glucose (1.0 g/L) conditions to understand how substrate availability affects the myotube response to EL-EPS. The C2C12 myotube, media, and cell-free media metabolites were analyzed using untargeted nuclear magnetic resonance (NMR)-based metabolomics. Furthermore, translational and metabolic changes and possible exerkine effects were analyzed. EL-EPS enhanced substrate utilization as well as production and secretion of lactate, acetate, 3-hydroxybutyrate, and branched-chain fatty acids (BCFAs). The increase in BCFAs correlated with branched-chain amino acids (BCAAs) and BCFAs were strongly decreased when myotubes were cultured without BCAAs suggesting the action of acyl-CoA thioesterases on BCAA catabolites. Notably, not all EL-EPS responses were augmented by high glucose because EL-EPS increased phosphorylated c-Jun N-terminal kinase and interleukin-6 secretion independent of glucose availability. Administration of acetate and EL-EPS conditioned media on HepG2 hepatocytes had no adverse effects on lipolysis or triacylglycerol content. Our results demonstrate that unlike in cell-free media, the C2C12 myotube and media metabolites were affected by EL-EPS, particularly under high-glucose condition suggesting that media composition should be considered in future EL-EPS studies. Furthermore, acetate and BCFAs were identified as putative exerkines warranting more research.NEW & NOTEWORTHY The present study examined for the first time the metabolome of 1) C2C12 myotubes, 2) their growth media, and 3) cell-free media after exercise-like electrical pulse stimulation under distinct nutritional loads. We report that myotubes grown under high-glucose conditions had greater responsiveness to EL-EPS when compared with lower glucose availability conditions and increased media content of acetate and branched-chain fatty acids suggests they might act as putative exerkines warranting further research.


Assuntos
Estimulação Elétrica , Glucose/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Condicionamento Físico Animal , Aminoácidos de Cadeia Ramificada/metabolismo , Animais , Células Cultivadas , Camundongos
19.
Nutrients ; 13(6)2021 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-34067295

RESUMO

We aimed to identify plasma and urine metabolites altered by the Dietary Approaches to Stop Hypertension (DASH) diet in a post-hoc analysis of a pilot feeding trial. Twenty adult participants with un-medicated hypertension consumed a Control diet for one week followed by 2 weeks of random assignment to either Control or DASH diet. Non-missing fasting plasma (n = 56) and 24-h urine (n = 40) were used to profile metabolites using untargeted gas chromatography/mass spectrometry. Linear models were used to compare metabolite levels between the groups. In urine, 19 identifiable untargeted metabolites differed between groups at p < 0.05. These included a variety of phenolic acids and their microbial metabolites that were higher during the DASH diet, with many at false discovery rate (FDR) adjusted p < 0.2. In plasma, eight identifiable untargeted metabolites were different at p < 0.05, but only gamma-tocopherol was significantly lower on DASH at FDR adjusted p < 0.2. The results provide insights into the mechanisms of benefit of the DASH diet.


Assuntos
Abordagens Dietéticas para Conter a Hipertensão/métodos , Hipertensão/sangue , Hipertensão/urina , Metabolômica/métodos , Adulto , Pressão Sanguínea , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Hipertensão/dietoterapia , Modelos Lineares , Masculino , Metaboloma , Pessoa de Meia-Idade , Projetos Piloto , Resultado do Tratamento
20.
BMJ Glob Health ; 6(6)2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34103326

RESUMO

INTRODUCTION: Uganda's district-level administrative units buttress the public healthcare system. In many districts, however, local capacity is incommensurate with that required to plan and implement quality health interventions. This study investigates how a district management strategy informed by local data and community dialogue influences health services. METHODS: A 3-year randomised controlled trial (RCT) comprised of 16 Ugandan districts tested a management approach, Community and District-management Empowerment for Scale-up (CODES). Eight districts were randomly selected for each of the intervention and comparison areas. The approach relies on a customised set of data-driven diagnostic tools to identify and resolve health system bottlenecks. Using a difference-in-differences approach, the authors performed an intention-to-treat analysis of protective, preventive and curative practices for malaria, pneumonia and diarrhoea among children aged 5 and younger. RESULTS: Intervention districts reported significant net increases in the treatment of malaria (+23%), pneumonia (+19%) and diarrhoea (+13%) and improved stool disposal (+10%). Coverage rates for immunisation and vitamin A consumption saw similar improvements. By engaging communities and district managers in a common quest to solve local bottlenecks, CODES fostered demand for health services. However, limited fiscal space-constrained district managers' ability to implement solutions identified through CODES. CONCLUSION: Data-driven district management interventions can positively impact child health outcomes, with clinically significant improvements in the treatment of malaria, pneumonia and diarrhoea as well as stool disposal. The findings recommend the model's suitability for health systems strengthening in Uganda and other decentralised contexts. TRIAL REGISTRATION NUMBER: ISRCTN15705788.


Assuntos
Serviços de Saúde da Criança , Malária , Criança , Saúde da Criança , Atenção à Saúde , Humanos , Malária/epidemiologia , Malária/prevenção & controle , Uganda/epidemiologia
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