RESUMEN
The TFE3 and MITF master transcription factors maintain metabolic homeostasis by regulating lysosomal, melanocytic, and autophagy genes. Previous studies posited that their cytosolic retention by 14-3-3, mediated by the Rag GTPases-mTORC1, was key for suppressing transcriptional activity in the presence of nutrients. Here, we demonstrate using mammalian cells that regulated protein stability plays a fundamental role in their control. Amino acids promote the recruitment of TFE3 and MITF to the lysosomal surface via the Rag GTPases, activating an evolutionarily conserved phospho-degron and leading to ubiquitination by CUL1ß-TrCP and degradation. Elucidation of the minimal functional degron revealed a conserved alpha-helix required for interaction with RagA, illuminating the molecular basis for a severe neurodevelopmental syndrome caused by missense mutations in TFE3 within the RagA-TFE3 interface. Additionally, the phospho-degron is recurrently lost in TFE3 genomic translocations that cause kidney cancer. Therefore, two divergent pathologies converge on the loss of protein stability regulation by nutrients.
Asunto(s)
Aminoácidos , Factor de Transcripción Asociado a Microftalmía , Animales , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Factor de Transcripción Asociado a Microftalmía/genética , Factor de Transcripción Asociado a Microftalmía/metabolismo , Aminoácidos/metabolismo , Nutrientes , Estabilidad Proteica , Lisosomas/genética , Lisosomas/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Mamíferos/metabolismoRESUMEN
Diet greatly influences gene expression and physiology. In mammals, elucidating the effects and mechanisms of individual nutrients is challenging due to the complexity of both the animal and its diet. Here, we used an interspecies systems biology approach with Caenorhabditis elegans and two of its bacterial diets, Escherichia coli and Comamonas aquatica, to identify metabolites that affect the animal's gene expression and physiology. We identify vitamin B12 as the major dilutable metabolite provided by Comamonas aq. that regulates gene expression, accelerates development, and reduces fertility but does not affect lifespan. We find that vitamin B12 has a dual role in the animal: it affects development and fertility via the methionine/S-Adenosylmethionine (SAM) cycle and breaks down the short-chain fatty acid propionic acid, preventing its toxic buildup. Our interspecies systems biology approach provides a paradigm for understanding complex interactions between diet and physiology.
Asunto(s)
Betaproteobacteria/metabolismo , Caenorhabditis elegans/fisiología , Escherichia coli/metabolismo , Regulación de la Expresión Génica , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/crecimiento & desarrollo , Dieta , Redes y Vías Metabólicas , Metionina/metabolismo , Datos de Secuencia Molecular , Propionatos/metabolismo , S-Adenosilmetionina/metabolismo , Transcriptoma , Vitamina B 12/metabolismoRESUMEN
Focal copy-number amplification is an oncogenic event. Although recent studies have revealed the complex structure1-3 and the evolutionary trajectories4 of oncogene amplicons, their origin remains poorly understood. Here we show that focal amplifications in breast cancer frequently derive from a mechanism-which we term translocation-bridge amplification-involving inter-chromosomal translocations that lead to dicentric chromosome bridge formation and breakage. In 780 breast cancer genomes, we observe that focal amplifications are frequently connected to each other by inter-chromosomal translocations at their boundaries. Subsequent analysis indicates the following model: the oncogene neighbourhood is translocated in G1 creating a dicentric chromosome, the dicentric chromosome is replicated, and as dicentric sister chromosomes segregate during mitosis, a chromosome bridge is formed and then broken, with fragments often being circularized in extrachromosomal DNAs. This model explains the amplifications of key oncogenes, including ERBB2 and CCND1. Recurrent amplification boundaries and rearrangement hotspots correlate with oestrogen receptor binding in breast cancer cells. Experimentally, oestrogen treatment induces DNA double-strand breaks in the oestrogen receptor target regions that are repaired by translocations, suggesting a role of oestrogen in generating the initial translocations. A pan-cancer analysis reveals tissue-specific biases in mechanisms initiating focal amplifications, with the breakage-fusion-bridge cycle prevalent in some and the translocation-bridge amplification in others, probably owing to the different timing of DNA break repair. Our results identify a common mode of oncogene amplification and propose oestrogen as its mechanistic origin in breast cancer.
Asunto(s)
Neoplasias de la Mama , Receptor alfa de Estrógeno , Amplificación de Genes , Oncogenes , Translocación Genética , Femenino , Humanos , Neoplasias de la Mama/genética , Receptor alfa de Estrógeno/metabolismo , Estrógenos/metabolismo , Oncogenes/genética , Translocación Genética/genética , Genoma Humano/genética , Roturas del ADN de Doble Cadena , Especificidad de ÓrganosRESUMEN
Understanding the genetic control of human embryonic stem cell function is foundational for developmental biology and regenerative medicine. Here we describe an integrated genome-scale loss- and gain-of-function screening approach to identify genetic networks governing embryonic stem cell proliferation and differentiation into the three germ layers. We identified a deep link between pluripotency maintenance and survival by showing that genetic alterations that cause pluripotency dissolution simultaneously increase apoptosis resistance. We discovered that the chromatin-modifying complex SAGA and in particular its subunit TADA2B are central regulators of pluripotency, survival, growth, and lineage specification. Joint analysis of all screens revealed that genetic alterations that broadly inhibit differentiation across multiple germ layers drive proliferation and survival under pluripotency-maintaining conditions and coincide with known cancer drivers. Our results show the power of integrated multilayer genetic screening for the robust mapping of complex genetic networks.
Asunto(s)
Células Madre Embrionarias Humanas , Diferenciación Celular/genética , Células Madre Embrionarias , Mutación con Ganancia de Función , Estratos Germinativos , HumanosRESUMEN
Dietary composition has major effects on physiology. Here, we show that developmental rate, reproduction, and lifespan are altered in C. elegans fed Comamonas DA1877 relative to those fed a standard E. coli OP50 diet. We identify a set of genes that change in expression in response to this diet and use the promoter of one of these (acdh-1) as a dietary sensor. Remarkably, the effects on transcription and development occur even when Comamonas DA1877 is diluted with another diet, suggesting that Comamonas DA1877 generates a signal that is sensed by the nematode. Surprisingly, the developmental effect is independent from TOR and insulin signaling. Rather, Comamonas DA1877 affects cyclic gene expression during molting, likely through the nuclear hormone receptor NHR-23. Altogether, our findings indicate that different bacteria elicit various responses via distinct mechanisms, which has implications for diseases such as obesity and the interactions between the human microbiome and intestinal cells.
Asunto(s)
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiología , Insulina/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Acil-CoA Deshidrogenasa/metabolismo , Animales , Betaproteobacteria , Caenorhabditis elegans/metabolismo , Dieta , Escherichia coli , Expresión Génica , Longevidad , Muda , Receptores Citoplasmáticos y Nucleares/metabolismo , Inanición , TranscriptomaRESUMEN
Expression profiles are tailored according to dietary input. However, the networks that control dietary responses remain largely uncharacterized. Here, we combine forward and reverse genetic screens to delineate a network of 184 genes that affect the C. elegans dietary response to Comamonas DA1877 bacteria. We find that perturbation of a mitochondrial network composed of enzymes involved in amino acid metabolism and the TCA cycle affects the dietary response. In humans, mutations in the corresponding genes cause inborn diseases of amino acid metabolism, most of which are treated by dietary intervention. We identify several transcription factors (TFs) that mediate the changes in gene expression upon metabolic network perturbations. Altogether, our findings unveil a transcriptional response system that is poised to sense dietary cues and metabolic imbalances, illustrating extensive communication between metabolic networks in the mitochondria and gene regulatory networks in the nucleus.
Asunto(s)
Caenorhabditis elegans/metabolismo , Redes Reguladoras de Genes , Redes y Vías Metabólicas , Acil-CoA Deshidrogenasa/metabolismo , Animales , Betaproteobacteria , Proteínas de Caenorhabditis elegans/metabolismo , Dieta , Escherichia coli , Humanos , Insulina/metabolismo , Errores Innatos del Metabolismo , Mitocondrias/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Interferencia de ARN , Transducción de Señal , Factores de Transcripción/metabolismoRESUMEN
Tyrosine sulfation is a post-translational modification (PTM) that modulates function by mediating key protein-protein interactions. One of the early proteins shown to possess this PTM was hirudin, produced in the salivary glands of the medicinal leech Hirudo medicinalis, whereby tyrosine sulfation led to a â¼10-fold improvement in α-thrombin inhibitory activity. Outside of this pioneering discovery, the involvement of tyrosine sulfation in modulating the activity of salivary proteins from other hematophagous organisms was unknown. We hypothesized that the intrinsic instability of the tyrosine sulfate functionality, particularly under the acidic conditions used to isolate and analyze peptides and proteins, has led to poor detection during the isolation and/or expression of these molecules.Herein, we summarize our efforts to interrogate the functional role of tyrosine sulfation in the thrombin inhibitory and anticoagulant activity of salivary peptides and proteins from a range of different blood feeding organisms, including leeches, ticks, mosquitoes, and flies. Specifically, we have harnessed synthetic chemistry to efficiently generate homogeneously sulfated peptides and proteins for detailed structure-function studies both in vitro and in vivo.Our studies began with the leech protein hirudin P6 (from Hirudinaria manillensis), which is both sulfated on tyrosine and O-glycosylated at a nearby threonine residue. Synthetically, this was achieved through solid-phase peptide synthesis (SPPS) with a late-stage on-resin sulfation, followed by native chemical ligation and a folding step to generate six differentially modified variants of hirudin P6 to assess the functional interplay between O-glycosylation and tyrosine sulfation. A one-pot, kinetically controlled ligation of three peptide fragments was used to assemble homogeneously sulfoforms of madanin-1 and chimadanin from the tick Haemaphysalis longicornis. Dual tyrosine sulfation at two distinct sites was shown to increase the thrombin inhibitory activity by up to 3 orders of magnitude through a novel interaction with exosite II of thrombin. The diselenide-selenoester ligation developed by our lab provided us with a means to rapidly assemble a library of different sulfated tick anticoagulant proteins: the andersonins, hyalomins, madanin-like proteins, and hemeathrins, thus enabling the generation of key structure-activity data on this family of proteins. We have also confirmed the presence of tyrosine sulfation in the anticoagulant proteins of Anopheles mosquitoes (anophelins) and the Tsetse fly (TTI) via insect expression and mass spectrometric analysis. These molecules were subsequently synthesized and assessed for thrombin inhibitory and anticoagulant activity. Activity was significantly improved by the addition of tyrosine sulfate modifications and led to molecules with potent antithrombotic activity in an in vivo murine thrombosis model.The Account concludes with our most recent work on the design of trivalent hybrids that tandemly occupy the active site and both exosites (I and II) of α-thrombin, with a TTI-anophelin hybrid (Ki = 20 fM against α-thrombin) being one of the most potent protease inhibitors and anticoagulants ever generated. Taken together, this Account highlights the importance of the tyrosine sulfate post-translational modification within salivary proteins from blood feeding organisms for enhancing anticoagulant activity. This work lays the foundation for exploiting native or engineered variants as therapeutic leads for thrombotic disorders in the future.
Asunto(s)
Anticoagulantes , Trombina , Animales , Ratones , Anticoagulantes/farmacología , Secuencia de Aminoácidos , Trombina/metabolismo , Hirudinas/farmacología , Hirudinas/química , Hirudinas/metabolismo , Tirosina/química , Proteínas y Péptidos SalivalesRESUMEN
Skeletal muscle dysfunction is common in chronic kidney disease (CKD). Of interest is the concept of "muscle quality," of which measures include ultrasound-derived echo intensity (EI). Alternative parameters of muscle texture, for example, gray level of co-occurrence matrix (GCLM), are available and may circumvent limitations in EI. The validity of EI is limited in humans, particularly in chronic diseases. This study aimed to investigate the associations between ultrasound-derived parameters of muscle texture with MRI. Images of the thigh were acquired using a 3 Tesla MRI scanner. Quantification of muscle (contractile), fat (non-contractile), and miscellaneous (connective tissue, fascia) components were estimated. Anatomical rectus femoris cross-sectional area was measured using B-mode 2D ultrasonography. To assess muscle texture, first (i.e., EI)- and second (i.e., GLCM)-order statistical analyses were performed. Fourteen participants with CKD were included (age: 58.0 ± 11.9 years, 50% male, eGFR: 27.0 ± 7.4 ml/min/1.73m2, 55% Stage 4). Higher EI was associated with lower muscle % (quadriceps: ß = -.568, p = .034; hamstrings: ß = -.644, p = .010). Higher EI was associated with a higher fat % in the hamstrings (ß = -.626, p = .017). A higher angular second moment from GLCM analysis was associated with greater muscle % (ß = .570, p = .033) and lower fat % (ß = -.534, p = .049). A higher inverse difference moment was associated with greater muscle % (ß = .610, p = .021 and lower fat % (ß = -.599, p = .024). This is the first study to investigate the associations between ultrasound-derived parameters of muscle texture with MRI. Our preliminary findings suggest ultrasound-derived texture analysis provides a novel indicator of reduced skeletal muscle % and thus increased intramuscular fat.
Asunto(s)
Imagen por Resonancia Magnética , Músculo Esquelético , Insuficiencia Renal Crónica , Ultrasonografía , Humanos , Masculino , Insuficiencia Renal Crónica/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Persona de Mediana Edad , Femenino , Ultrasonografía/métodos , Músculo Esquelético/diagnóstico por imagen , Anciano , Reproducibilidad de los ResultadosRESUMEN
Collaboration within mental health centres and with municipalities in Western European healthcare has presented challenges due to structural and cultural disparities. The Danish healthcare system faces obstacles that impact mental healthcare services, particularly in cross-sectorial cooperation. Our aim was to investigate healthcare professionals' experiences of recovery-oriented collaboration within a mental healthcare setting across hospitals and municipalities to gather a deeper understanding of this issue. Twenty-four employees were purposively sampled from mental health centres in Copenhagen and focus group interviews were conducted to explore their perceptions of working together. Inductive content analysis was used to analyse the data and identify themes and categories. The participants emphasised challenges in communication and coordination to improve collaboration within across the two sectors. This study can contribute to a greater understanding of collaboration between mental health centres and municipalities. It aims to inspire improvements in communication, coordination, and the optimisation of mental health service delivery across sectors.
Asunto(s)
Personal de Salud , Salud Mental , Humanos , Ciudades , Personal de Salud/psicología , Investigación Cualitativa , Actitud del Personal de SaludRESUMEN
AIM: This scoping review aims to synthesize findings from fourteen selected articles to provide a comprehensive understanding of patient participation in mental healthcare. METHOD: The review analyzed articles employing various qualitative methodologies, including interviews and observations, to explore patient and healthcare professional perspectives. Articles were selected based on their relevance to the topic of patient participation in mental health care. RESULTS: The analysis revealed diverse perspectives on patient participation. Patients' preferences varied, with some preferring shared decision-making while others preferred minimal involvement. Barriers to shared decision-making included fear of judgment and substance misuse concerns. Strategies to manage disagreements and foster trusting relationships were identified. Challenges in implementing patient and public involvement in mental health services were noted, including stigma and inadequate professional training. Interprofessional collaboration was deemed fundamental, although fragmented care pathways and communication breakdowns persisted. Structural conditions and professional expectations significantly influenced patient participation, with a paternalistic approach perpetuating power imbalances. CONCLUSION: Despite challenges, the findings underscored the importance of empowering patients in treatment decision-making, promoting collaborative relationships, and addressing barriers to enhance patient-centered care in mental health settings. Insights from this review contribute to the discourse on patient-centered care, emphasizing the need for holistic approaches prioritizing patient dignity and well-being.
Asunto(s)
Servicios de Salud Mental , Participación del Paciente , Humanos , Participación del Paciente/psicología , Servicios de Salud Mental/organización & administración , Atención Dirigida al Paciente , Actitud del Personal de Salud , Trastornos Mentales/terapia , Trastornos Mentales/psicología , Toma de Decisiones Conjunta , Personal de Salud/psicología , Relaciones Profesional-PacienteRESUMEN
Metabolic networks are extensively regulated to facilitate tissue-specific metabolic programs and robustly maintain homeostasis in response to dietary changes. Homeostatic metabolic regulation is achieved through metabolite sensing coupled to feedback regulation of metabolic enzyme activity or expression. With a wealth of transcriptomic, proteomic, and metabolomic data available for different cell types across various conditions, we are challenged with understanding global metabolic network regulation and the resulting metabolic outputs. Stoichiometric metabolic network modeling integrated with "omics" data has addressed this challenge by generating nonintuitive, testable hypotheses about metabolic flux rewiring. Model organism studies have also yielded novel insight into metabolic networks. This review covers three topics: the feedback loops inherent in metabolic regulatory networks, metabolic network modeling, and interspecies studies utilizing Caenorhabditis elegans and various bacterial diets that have revealed novel metabolic paradigms.
Asunto(s)
Caenorhabditis elegans/metabolismo , Redes y Vías Metabólicas , Modelos Biológicos , Modelos Teóricos , Animales , Caenorhabditis elegans/genética , Enzimas/genética , Enzimas/metabolismo , Retroalimentación Fisiológica , Regulación de la Expresión Génica , Genómica/métodos , Homeostasis , Humanos , Neoplasias/metabolismoRESUMEN
OBJECTIVE: To estimate the independent and combined effects of in utero exposures on birth outcomes in a rural population. STUDY DESIGN: The study used population-level data (2020-2022) from a state-wide surveillance tool (Working in Appalachia to identify at-risk infants, Critical congenital heart disease, and Hearing loss) in West Virginia. Outcomes included low birth weight, preterm birth, small for gestational age, and birth weight in grams. Exposure included a composite variable with 8 levels of 3 exposure (opioids, stimulants, and cannabis) categories. Analyses were adjusted for sociodemographic covariates using multiple logistic and linear regression analyses. RESULTS: Of the 34â412 singleton live births, 1 in 8 newborns (12.2%) had in utero exposure(s) to opioids, stimulants, and/or cannabis, 11.5% were preterm, 7.9% had low birthweight, 9.6% were small for gestational age, and mean birth weight was 3249 ± 563.6 g. Preterm birth was associated with stimulant alone exposure (aOR, 1.40; 95% CI, 1.03-1.89) and stimulant and cannabis concurrent exposure (aOR, 1.69; 95% CI, 1.16, 2.47). Low birthweight was associated with opioids alone (aOR, 1.34; 95% CI, 1.10, 1.63), cannabis alone (aOR, 1.31; 95% CI, 1.13 to -1.52), opioid and cannabis (aOR, 1.61; 95% CI, 1.12 to -2.31), and opioids, stimulants, and cannabis concurrent exposures (aOR, 2.27; 95% CI, 1.43-3.61). Five exposure categories were associated with lower birth weights (adjusted mean difference range. -72 to -211 g). Small for gestational age was associated with opioids alone (aOR, 1.48; 95% CI, 1.24-1.78), cannabis alone (aOR, 1.49; 95% CI, 1.31-1.69), and opioids and cannabis concurrent exposures (aOR, 1.91; 95% CI, 1.36-2.67). CONCLUSIONS: We showed complex associations between in utero substance exposures, preterm birth, birth weight, and sociodemographic factors in a rural population. The results may inform policy efforts to improve maternal and child health in socioeconomically disadvantaged and underserved rural populations.
Asunto(s)
Cannabis , Nacimiento Prematuro , Lactante , Femenino , Niño , Recién Nacido , Humanos , Nacimiento Prematuro/epidemiología , Peso al Nacer , Estudios de Cohortes , Analgésicos Opioides/efectos adversos , Recién Nacido de Bajo Peso , Cannabis/efectos adversosRESUMEN
BACKGROUND: People with chronic kidney disease (CKD) experience skeletal muscle wasting, reduced levels of physical function and performance, and chronic systemic inflammation. While it is known that a relationship exists between inflammation and muscle wasting, the association between inflammation and physical function or performance in CKD has not been well studied. Exercise has anti-inflammatory effects, but little is known regarding the effect of moderate intensity exercise. This study aimed to (i) compare systemic and intramuscular inflammation between CKD stage G3b-5 and non-CKD controls; (ii) establish whether a relationship exists between physical performance, exercise capacity and inflammation in CKD; (iii) determine changes in systemic and intramuscular inflammation following 12 weeks of exercise; and (iv) investigate whether improving inflammatory status via training contributes to improvements in physical performance and muscle mass. METHODS: This is a secondary analysis of previously collected data. CKD patients stages G3b-5 (n = 84, n = 43 males) and non-CKD controls (n = 26, n = 17 males) underwent tests of physical performance, exercise capacity, muscle strength and muscle size. In addition, a subgroup of CKD participants underwent 12 weeks of exercise training, randomized to aerobic (AE, n = 21) or combined (CE, n = 20) training. Plasma and intramuscular inflammation and myostatin were measured at rest and following exercise. RESULTS: Tumour necrosis factor-α was negatively associated with lower $^{^{^{.}}}{\rm V}$O2Peak (P = 0.01), Rectus femoris-cross sectional area (P = 0.002) and incremental shuttle walk test performance (P < 0.001). Interleukin-6 was negatively associated with sit-to-stand 60 performances (P = 0.006) and hand grip strength (P = 0.001). Unaccustomed exercise created an intramuscular inflammatory response that was attenuated following 12 weeks of training. Exercise training did not reduce systemic inflammation, but AE training did significantly reduce mature myostatin levels (P = 0.02). Changes in inflammation were not associated with changes in physical performance. CONCLUSIONS: Systemic inflammation may contribute to reduced physical function in CKD. Twelve weeks of exercise training was unable to reduce the level of chronic systemic inflammation in these patients, but did reduce plasma myostatin concentrations. Further research is required to further investigate this.
Asunto(s)
Fallo Renal Crónico , Insuficiencia Renal Crónica , Ejercicio Físico , Terapia por Ejercicio , Femenino , Fuerza de la Mano , Humanos , Inflamación/complicaciones , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Masculino , Atrofia Muscular/complicaciones , Miostatina , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/terapiaRESUMEN
OBJECTIVE: To provide an overview of systems available for peripheral arterial disease (PAD) screening, together with respective accuracies and a clinical evaluation to identify a system suitable for use in a community screening programme. METHODS: A systematic review of the diagnostic accuracy of six ankle brachial pressure index (ABPI) and toe brachial pressure index (TBPI) devices deemed to be portable, which were Conformité Européenne (CE) marked, and were automated or semi-automated was carried out compared with gold standard handheld Doppler and duplex ultrasound. The devices were MESI-ABPI-MD, Huntleigh Dopplex Ability, Huntleigh ABPI and TBPI systems, Systoe TBPI system, and BlueDop. Seven databases (MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Register of Controlled Trials (CENTRAL), and Cumulative Index to Nursing and Allied Health Literature (CINAHL)) were searched, and 11 studies were identified as eligible for review. This was followed by hands on clinical evaluation by abdominal aortic aneurysm (AAA) screening staff (n = 39). During this, devices were demonstrated to staff which they then tested on volunteers and gave feedback using pre-designed questionnaires on their suitability for use in a screening programme. Finally, accuracy data and staff preferences were combined during a consensus conference that was held between study and screening staff to determine the most appropriate device to use in a community screening programme. RESULTS: Generally, the evaluated systems have a moderate level of sensitivity and a high level of specificity: Dopplex ability sensitivity 20% - 70%, specificity 86% - 96%; MESI sensitivity 57% - 74%, specificity 85% - 99%; BlueDop sensitivity 95%, specificity 89%; and Systoe sensitivity 71%, specificity 77%. Clinical evaluation by screening staff identified a preference for the MESI system. The consensus conference concluded that the MESI device was a good candidate for use in a community PAD screening programme. CONCLUSION: The MESI system is a good candidate to consider for community PAD screening.
Asunto(s)
Tobillo , Enfermedad Arterial Periférica , Humanos , Índice Tobillo Braquial , Enfermedad Arterial Periférica/diagnóstico , Dedos del PieRESUMEN
BACKGROUND: Many people living with chronic kidney disease (CKD) are iron deficient, even though they may not be anaemic. The Iron and Muscle study aims to evaluate whether iron supplementation reduces symptoms of fatigue, improves muscle metabolism, and leads to enhanced exercise capacity and physical function. We report here the trial design and baseline characteristics. METHODS: This is a prospective, double-blind multicentre randomised controlled trial (RCT) including 75 non-dialysis stage 3-4 CKD patients with iron deficiency but without anaemia. Patients were randomly (1:1) assigned to either: i) intravenous iron therapy, or ii) placebo, with concurrent recruitment of eight CKD non-iron deficient participants and six healthy volunteers. The primary outcome of the study is the six-minute walk test (6MWT) distance between baseline and four-weeks. An additional exercise training programme for patients in both groups was initiated and completed between 4 and 12 weeks, to determine the effect of iron repletion compared to placebo treatment in the context of patients undertaking an exercise programme. Additional secondary outcomes include fatigue, physical function, muscle strength, muscle metabolism, quality of life, resting blood pressure, clinical chemistry, safety and harms associated with the iron therapy intervention and the exercise training intervention, and hospitalisations. All outcomes were conducted at baseline, 4, and 12 weeks, with a nested qualitative study, to investigate the experience of living with iron deficiency and intervention acceptability. The cohort have been recruited and baseline assessments undertaken. RESULTS: Seventy-five individuals were recruited. 44% of the randomised cohort were male, the mean (SD) age was 58 (14) years, and 56% were White. Body mass index was 31 (7) kg/m2; serum ferritin was 59 (45) µg/L, transferrin saturation was 22 (10) %, and haemoglobin was 125 (12) g/L at randomisation for the whole group. Estimated glomerular filtration rate was 35 (12) mL/min/1.73 m2 and the baseline 6MWT distance was 429 (174) m. CONCLUSION: The results from this study will address a substantial knowledge gap in the effects of intravenous iron therapy, and offer potential clinical treatment options, to improve exercise capacity, physical function, fatigue, and muscle metabolism, for non-dialysis patients with CKD who are iron-deficient but not anaemic. It will also offer insight into the potential novel effects of an 8-week exercise training programme. TRIAL REGISTRATION: EudraCT: 2018-000,144-25 Registered 28/01/2019.
Asunto(s)
Anemia , Deficiencias de Hierro , Insuficiencia Renal Crónica , Suplementos Dietéticos , Método Doble Ciego , Tolerancia al Ejercicio , Fatiga , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/tratamiento farmacológico , Resultado del TratamientoRESUMEN
Large mandibular defects are clinically challenging to reconstruct due to the complex anatomy of the jaw and the limited availability of appropriate tissue for repair. We envision leveraging current advances in fabrication and biomaterials to create implantable devices that generate bone within the patients themselves suitable for their own specific anatomical pathology. The in vivo bioreactor strategy facilitates the generation of large autologous vascularized bony tissue of customized geometry without the addition of exogenous growth factors or cells. To translate this technology, we investigated its success in reconstructing a mandibular defect of physiologically relevant size in sheep. We fabricated and implanted 3D-printed in vivo bioreactors against rib periosteum and utilized biomaterial-based space maintenance to preserve the native anatomical mandibular structure in the defect site before reconstruction. Nine weeks after bioreactor implantation, the ovine mandibles were repaired with the autologous bony tissue generated from the in vivo bioreactors. We evaluated tissues generated in bioreactors by radiographic, histological, mechanical, and biomolecular assays and repaired mandibles by radiographic and histological assays. Biomaterial-aided mandibular reconstruction was successful in a large superior marginal defect in five of six (83%) sheep. Given that these studies utilized clinically available biomaterials, such as bone cement and ceramic particles, this strategy is designed for rapid human translation to improve outcomes in patients with large mandibular defects.
Asunto(s)
Sustitutos de Huesos , Mandíbula , Traumatismos Mandibulares , Periostio , Impresión Tridimensional , Ingeniería de Tejidos , Animales , Reactores Biológicos , Femenino , Mandíbula/metabolismo , Mandíbula/patología , Traumatismos Mandibulares/metabolismo , Traumatismos Mandibulares/patología , Traumatismos Mandibulares/terapia , Periostio/metabolismo , Periostio/patología , OvinosRESUMEN
Hematophagous organisms produce a suite of salivary proteins which interact with the host's coagulation machinery to facilitate the acquisition and digestion of a bloodmeal. Many of these biomolecules inhibit the central blood-clotting serine proteinase thrombin that is also the target of several clinically approved anticoagulants. Here a bioinformatics approach is used to identify seven tick proteins with putative thrombin inhibitory activity that we predict to be posttranslationally sulfated at two conserved tyrosine residues. To corroborate the biological role of these molecules and investigate the effects of amino acid sequence and sulfation modifications on thrombin inhibition and anticoagulant activity, a library of 34 homogeneously sulfated protein variants were rapidly assembled using one-pot diselenide-selenoester ligation (DSL)-deselenization chemistry. Downstream functional characterization validated the thrombin-directed activity of all target molecules and revealed that posttranslational sulfation of specific tyrosine residues crucially modulates potency. Importantly, access to this homogeneously modified protein library not only enabled the determination of key structure-activity relationships and the identification of potent anticoagulant leads, but also revealed subtleties in the mechanism of thrombin inhibition, between and within the families, that would be impossible to predict from the amino acid sequence alone. The synthetic platform described here therefore serves as a highly valuable tool for the generation and thorough characterization of libraries of related peptide and/or protein molecules (with or without modifications) for the identification of lead candidates for medicinal chemistry programs.
Asunto(s)
Anticoagulantes/química , Proteínas de Insectos/química , Proteínas y Péptidos Salivales/química , Trombina/química , Secuencia de Aminoácidos/genética , Coagulación Sanguínea/genética , Biología Computacional , Biblioteca de Genes , Humanos , Proteínas de Insectos/genética , Procesamiento Proteico-Postraduccional/genética , Proteínas y Péptidos Salivales/genética , Relación Estructura-Actividad , Trombina/antagonistas & inhibidores , Trombina/genética , Tirosina/químicaRESUMEN
In chronic kidney disease (CKD), handgrip strength (HGS) is recommended as a surrogate measure of protein-energy status and functional status. However, it is not routinely used because of inconsistencies such as the optimal timing of the HGS measurement and unclear guidance regarding technique. We aimed to determine the extent of variation in the protocols and methods of HGS assessment. We aimed to identify clinical and epidemiological studies conducted on CKD that reported on the use of HGS as an outcome. A systematic literature search identified n = 129 studies with a total participant population of n = 35,192. We identified large variations in all aspects of the methodology including body and arm position, repetitions, rest time, timing, familiarization, and how scores were calculated. The heterogeneous methodologies used reinforce the need to standardize HGS measurement. After reviewing previously employed methodology in the literature, we propose a comprehensive HGS assessment protocol for use in CKD.
Asunto(s)
Fuerza de la Mano , Insuficiencia Renal Crónica , Estudios Epidemiológicos , Humanos , Insuficiencia Renal Crónica/epidemiologíaRESUMEN
Mental health 'recovery narratives' are increasingly used within teaching, learning and practice environments. The mainstreaming of their use has been critiqued by scholars and activists as a co-option of lived experience for organisational purposes. But how people report their experiences of telling their stories has not been investigated at scale. We present accounts from 71 people with lived experience of multiple inequalities of telling their stories in formal and informal settings. A reflexive thematic analysis was conducted within a critical constructivist approach. Our overarching finding was that questions of power were central to all accounts. Four themes were identified: (1) Challenging the status quo; (2) Risky consequences; (3) Producing 'acceptable' stories; (4) Untellable stories. We discuss how the concept of narrative power foregrounds inequalities in settings within which recovery stories are invited and co-constructed, and conclude that power imbalances complicate the seemingly benign act of telling stories of lived experience.