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CONTEXT: There are limited comparative studies between one anastomosis gastric bypass (OAGB) versus Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on body composition and musculoskeletal health. OBJECTIVE: To compare changes in body composition, areal bone mineral density (aBMD), muscle strength, and physical function in the first year following OAGB, RYGB and SG within a UK-based healthcare setting. METHODS: This is a secondary analysis of the BARI-LIFESTYLE trial in 119 adults (77% women; mean±SD, age: 45.9±10.3 years; BMI: 43.6±5.5 kg/m2) who underwent OAGB (n=19), RYGB (n=39) and SG (n=61). Body composition and aBMD by dual energy x-ray absorptiometry, handgrip strength, sit-to-stand (STS) test and 6-minute walking test (6MWT) were assessed pre-surgery and at 12 months post-surgery. RESULTS: OAGB, RYGB, and SG exhibited similar reductions in body weight, body fat and lean mass (within-group comparisons, p<0.001). All surgery types were associated with reductions in aBMD at the total hip, femoral neck, and lumbar spine, which were more pronounced after OAGB and RYGB compared to SG (all p<0.03), though no difference between OAGB and RYGB. Despite reductions in absolute handgrip strength, relative handgrip strength, STS test and 6MWT improved post-surgery (all p<0.02), with no differences by surgical procedure. CONCLUSION: OAGB, RYGB, and SG resulted in comparable weight loss, changes in body composition and improvements in relative muscle strength and physical function. OAGB and RYGB, compared with SG, led to greater BMD reductions at clinically relevant sites. Future long-term studies should explore whether these BMD reductions translate into a greater fracture risk.
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BACKGROUND AND AIMS: High tissue sodium accumulation and intermuscular adipose tissue (IMAT) are associated with aging, type 2 diabetes, and chronic kidney disease. In this study, we aim to investigate whether high lower-extremity tissue sodium accumulation relates to IMAT quantity and whether systemic inflammatory mediators and adipocytokines contribute to such association. METHODS: Tissue sodium content and IMAT accumulation (percentage of IMAT area to muscle area) were measured in 83 healthy individuals using sodium imaging (23Na-MRI) and proton (1H-MRI) imaging of the calf. Insulin sensitivity was assessed by glucose disposal rate (GDR) measured with the hyperinsulinemic-euglycemic clamp. RESULTS: Median (interquartile range) muscle and skin sodium contents were 16.6 (14.9, 19.0) and 12.6 (10.9, 16.7) mmol/L, respectively. Median IMAT was 3.69 (2.80, 5.37) %. In models adjusted for age, sex, BMI, GDR, adiponectin, and high-sensitivity C-reactive protein, increasing tissue sodium content was significantly associated with higher IMAT quantity (p = 0.018 and 0.032 for muscle and skin tissue sodium, respectively). In subgroup analysis stratified by sex, skin sodium was significantly associated with IMAT only among men. In interaction analysis, the association between skin sodium and IMAT was greater with increasing levels of high-sensitivity C-reactive protein and interleukin-6 (p for interaction = 0.022 and 0.006, respectively). CONCLUSIONS: Leg muscle and skin sodium are associated with IMAT quantity among healthy individuals. The relationship between skin sodium and IMAT may be mediated by systemic inflammation.
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Tejido Adiposo , Músculo Esquelético , Sodio , Humanos , Masculino , Femenino , Tejido Adiposo/metabolismo , Tejido Adiposo/diagnóstico por imagen , Adulto , Sodio/metabolismo , Músculo Esquelético/metabolismo , Persona de Mediana Edad , Piel/metabolismo , Resistencia a la Insulina , Imagen por Resonancia Magnética/métodosRESUMEN
The realization of soft robotic devices with life-like properties requires the engineering of smart, active materials that can respond to environmental cues in similar ways as living cells or organisms. Cell-free expression systems provide an approach for embedding dynamic molecular control into such materials that avoids many of the complexities associated with genuinely living systems. Here, we present a strategy to integrate cell-free protein synthesis within agarose-based hydrogels that can be spatially organized and supplied by a synthetic vasculature. We first utilize an indirect printing approach with a commercial bioprinter and Pluronic F-127 as a fugitive ink to define fluidic channel structures within the hydrogels. We then investigate the impact of the gel matrix on the expression of proteins in E. coli cell-extract, which is found to depend on the gel density and the dilution of the expression system. When supplying the vascularized hydrogels with reactants, larger components such as DNA plasmids are confined to the channels or immobilized in the gels while nanoscale reaction components can diffusively spread within the gel. Using a single supply channel, we demonstrate different spatial protein concentration profiles emerging from different cell-free gene circuits comprising production, gene activation, and negative feedback. Variation of the channel design allows the creation of specific concentration profiles such as a long-term stable gradient or the homogeneous supply of a hydrogel with proteins.
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Bioimpresión , Sistema Libre de Células , Escherichia coli , Hidrogeles , Hidrogeles/química , Escherichia coli/genética , Escherichia coli/metabolismo , Bioimpresión/métodos , Poloxámero/química , Plásmidos/genética , Redes Reguladoras de Genes , Expresión Génica/genética , Sefarosa/química , Biología Sintética/métodosRESUMEN
Cell-free protein expression (CFE) systems have emerged as a critical platform for synthetic biology research. The vectors for protein expression in CFE systems mainly rely on double-stranded DNA and single-stranded RNA for transcription and translation processing. Here, we introduce a programmable vector - circular single-stranded DNA (CssDNA), which is shown to be processed by DNA and RNA polymerases for gene expression in a yeast-based CFE system. CssDNA is already widely employed in DNA nanotechnology due to its addressability and programmability. To apply above methods in the context of synthetic biology, CssDNA can not only be engineered for gene regulation via the different pathways of sense CssDNA and antisense CssDNA, but also be constructed into several gene regulatory logic gates in CFE systems. Our findings advance the understanding of how CssDNA can be utilized in gene expression and gene regulation, and thus enrich the synthetic biology toolbox.
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Sistema Libre de Células , ADN Circular , ADN de Cadena Simple , Vectores Genéticos , Saccharomyces cerevisiae , Biología Sintética , ADN de Cadena Simple/metabolismo , ADN de Cadena Simple/genética , Biología Sintética/métodos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , ADN Circular/genética , ADN Circular/metabolismo , Vectores Genéticos/metabolismo , Vectores Genéticos/genética , Regulación de la Expresión Génica , ARN Polimerasas Dirigidas por ADN/metabolismo , ARN Polimerasas Dirigidas por ADN/genéticaRESUMEN
BACKGROUND: Sodium-glucose cotransporter 2 inhibitors are believed to improve cardiac outcomes due to their osmotic diuretic potential. OBJECTIVES: The goal of this study was to test the hypothesis that vasopressin-driven urine concentration overrides the osmotic diuretic effect of glucosuria induced by dapagliflozin treatment. METHODS: DAPA-Shuttle1 (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment) was a single-center, double-blind, randomized, placebo-controlled trial, in which patients with chronic heart failure NYHA functional classes I/II and reduced ejection fraction were randomly assigned to receive dapagliflozin 10 mg daily or placebo (1:1) for 4 weeks. The primary endpoint was change from baseline in urine osmolyte concentration. Secondary endpoints included changes in copeptin levels and solute free water clearance. RESULTS: Thirty-three randomized, sodium-glucose cotransporter 2 inhibitor-naïve participants completed the study, 29 of whom (placebo: n = 14; dapagliflozin: n = 15) provided accurate 24-hour urine collections (mean age 59 ± 14 years; left ventricular ejection fraction 31% ± 9%). Dapagliflozin treatment led to an isolated increase in urine glucose excretion by 3.3 mmol/kg/d (95% CI: 2.51-4.04; P < 0.0001) within 48 hours (early) which persisted after 4 weeks (late; 2.7 mmol/kg/d [95% CI: 1.98-3.51]; P < 0.0001). Dapagliflozin treatment increased serum copeptin early (5.5 pmol/L [95% CI: 0.45-10.5]; P < 0.05) and late (7.8 pmol/L [95% CI: 2.77-12.81]; P < 0.01), leading to proportional reductions in free water clearance (early: -9.1 mL/kg/d [95% CI: -14 to -4.12; P < 0.001]; late: -11.0 mL/kg/d [95% CI: -15.94 to -6.07; P < 0.0001]) and elevated urine concentrations (late: 134 mmol/L [95% CI: 39.28-229.12]; P < 0.01). Therefore, urine volume did not significantly increase with dapagliflozin (mean difference early: 2.8 mL/kg/d [95% CI: -1.97 to 7.48; P = 0.25]; mean difference late: 0.9 mL/kg/d [95% CI: -3.83 to 5.62]; P = 0.70). CONCLUSIONS: Physiological-adaptive water conservation eliminated the expected osmotic diuretic potential of dapagliflozin and thereby prevented a glucose-driven increase in urine volume of approximately 10 mL/kg/d · 75 kg = 750 mL/kg/d. (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment [DAPA-Shuttle1]; NCT04080518).
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Compuestos de Bencidrilo , Conservación de los Recursos Hídricos , Diuresis , Glucósidos , Insuficiencia Cardíaca , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Anciano , Humanos , Persona de Mediana Edad , Diuréticos Osmóticos/farmacología , Diuréticos Osmóticos/uso terapéutico , Transportador 2 de Sodio-Glucosa , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Volumen Sistólico , Función Ventricular Izquierda , AguaRESUMEN
Molecular devices that have an anisotropic periodic potential landscape can be operated as Brownian motors. When the potential landscape is cyclically switched with an external force, such devices can harness random Brownian fluctuations to generate a directed motion. Recently, directed Brownian motor-like rotatory movement was demonstrated with an electrically switched DNA origami rotor with designed ratchet-like obstacles. Here, we demonstrate that the intrinsic anisotropy of DNA origami rotors is also sufficient to result in motor movement. We show that for low amplitudes of an external switching field, such devices operate as Brownian motors, while at higher amplitudes, they behave deterministically as overdamped electrical motors. We characterize the amplitude and frequency dependence of the movements, showing that after an initial steep rise, the angular speed peaks and drops for excessive driving amplitudes and frequencies. The rotor movement can be well described by a simple stochastic model of the system.
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ADN , ADN/química , Anisotropía , Movimiento (Física)RESUMEN
INTRODUCTION: Obesity increases the risk of morbidity and mortality. A major driver has been the increased availability of ultra-processed food (UPF), now the main UK dietary energy source. The UK Eatwell Guide (EWG) provides public guidance for a healthy balanced diet but offers no UPF guidance. Whether a healthy diet can largely consist of UPFs is unclear. No study has assessed whether the health impact of adhering to dietary guidelines depends on food processing. Furthermore, our study will assess the impact of a 6-month behavioural support programme aimed at reducing UPF intake in people with overweight/obesity and high UPF intakes. METHODS AND ANALYSIS: UPDATE is a 2×2 cross-over randomised controlled trial with a 6-month behavioural intervention. Fifty-five adults aged ≥18, with overweight/obesity (≥25 to <40 kg/m2), and ≥50% of habitual energy intake from UPFs will receive an 8-week UPF diet and an 8-week minimally processed food (MPF) diet delivered to their home, both following EWG recommendations, in a random order, with a 4-week washout period. All food/drink will be provided. Participants will then receive 6 months of behavioural support to reduce UPF intake. The primary outcome is the difference in weight change between UPF and MPF diets from baseline to week 8. Secondary outcomes include changes in diet, waist circumference, body composition, heart rate, blood pressure, cardiometabolic risk factors, appetite regulation, sleep quality, physical activity levels, physical function/strength, well-being and aspects of behaviour change/eating behaviour at 8 weeks between UPF/MPF diets, and at 6-month follow-up. Quantitative assessment of changes in brain MRI functional resting-state connectivity between UPF/MPF diets, and qualitative analysis of the behavioural intervention for feasibility and acceptability will be undertaken. ETHICS AND DISSEMINATION: Sheffield Research Ethics Committee approved the trial (22/YH/0281). Peer-reviewed journals, conferences, PhD thesis and lay media will report results. TRIAL REGISTRATION NUMBER: NCT05627570.
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Obesidad , Sobrepeso , Adulto , Humanos , Dieta , Ingestión de Energía , Reino Unido , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
BACKGROUND: Small arteries exhibit resting tone, a partially contracted state that maintains arterial blood pressure. In arterial smooth muscle cells, potassium channels control contraction and relaxation. Perivascular adipose tissue (PVAT) has been shown to exert anticontractile effects on the blood vessels. However, the mechanisms by which PVAT signals small arteries, and their relevance remain largely unknown. We aimed to uncover key molecular components in adipose-vascular coupling. METHODS: A wide spectrum of genetic mouse models targeting Kcnq3, Kcnq4, and Kcnq5 genes (Kcnq3-/-, Kcnq4-/-, Kcnq5-/-, Kcnq5dn/dn, Kcnq4-/-/Kcnq5dn/dn, and Kcnq4-/-/Kcnq5-/-), telemetry blood pressure measurements, targeted lipidomics, RNA-Seq profiling, wire-myography, patch-clamp, and sharp-electrode membrane potential measurements was used. RESULTS: We show that PVAT causes smooth muscle cell KV7.5 family of voltage-gated potassium (K+) channels to hyperpolarize the membrane potential. This effect relaxes small arteries and regulates blood pressure. Oxygenation of polyunsaturated fats generates oxylipins, a superclass of lipid mediators. We identified numerous oxylipins released by PVAT, which potentiate vasodilatory action in small arteries by opening smooth muscle cell KV7.5 family of voltage-gated potassium (K+) channels. CONCLUSIONS: Our results reveal a key molecular function of the KV7.5 family of voltage-gated potassium (K+) channels in the adipose-vascular coupling, translating PVAT signals, particularly oxylipins, to the central physiological function of vasoregulation. This novel pathway opens new therapeutic perspectives.
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Oxilipinas , Vasodilatación , Animales , Ratones , Tejido Adiposo , Canales de Potasio KCNQ/genética , Canales de Potasio KCNQ/metabolismo , Oxilipinas/metabolismo , Potasio/metabolismoRESUMEN
Brachydactyly type E (BDE), shortened metacarpals, metatarsals, cone-shaped epiphyses, and short stature commonly occurs as a sole phenotype. Parathyroid hormone-like protein (PTHrP) has been shown to be responsible in all forms to date, either directly or indirectly. We used linkage and then whole genome sequencing in a small pedigree, to elucidate BDE and identified a truncated disintegrin-and-metalloproteinase-19 (ADAM19) allele in all affected family members, but not in nonaffected persons. Since we had shown earlier that the extracellular domain of the parathyroid hormone receptor (PTHR1) is subject to an unidentified metalloproteinase cleavage, we tested the hypothesis that ADAM19 is a sheddase for PTHR1. WT ADAM19 cleaved PTHR1, while mutated ADAM-19 did not. We mapped the cleavage site that we verified with mass spectrometry between amino acids 64-65. ADAM-19 cleavage increased Gq and decreased Gs activation. Moreover, perturbed PTHR1 cleavage by ADAM19 increased ß-arrestin2 recruitment, while cAMP accumulation was not altered. We suggest that ADAM19 serves as a regulatory element for PTHR1 and could be responsible for BDE. This sheddase may affect other PTHrP or PTH-related functions.
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Braquidactilia , Proteína Relacionada con la Hormona Paratiroidea , Humanos , Proteína Relacionada con la Hormona Paratiroidea/genética , Braquidactilia/genética , Receptor de Hormona Paratiroídea Tipo 1/genética , Receptor de Hormona Paratiroídea Tipo 1/metabolismo , Metaloproteasas , Proteínas ADAMRESUMEN
The formation and dissociation of duplexes or higher order structures from nucleic acid strands is a fundamental process with widespread applications in biochemistry and nanotechnology. Here, we introduce a simple experimental system-a diffusiophoretic trap-for the non-equilibrium self-assembly of nucleic acid structures that uses an electrolyte gradient as the driving force. DNA strands can be concentrated up to hundredfold by a diffusiophoretic trapping force that is caused by the electric field generated by the electrolyte gradient. We present a simple equation for the field to guide selection of appropriate trapping electrolytes. Experiments with carboxylated silica particles demonstrate that the diffusiophoretic force is long-ranged, extending over hundreds of micrometers. As an application, we explore the reversible self-assembly of branched DNA nanostructures in the trap into a macroscopic gel. The structures assemble in the presence of an electrolyte gradient, and disassemble upon its removal, representing a prototypical adaptive response to a macroscopic non-equilibrium state.
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AIM: To place the consequences of calcineurin inhibition in a cardiovascular context. METHODS: Literature review coupled with personal encounters. RESULTS: Calcineurin is a calcium-binding and calmodulin-binding protein that is conserved across evolution from yeast to mammals. The enzyme functions as a calcium-dependent, calmodulin-stimulated protein phosphatase. Its role in regulating physiology has largely been elucidated by observing calcineurin inhibition. Calcineurin inhibition transformed organ transplantation from an experiment into a therapy and made much of general immunotherapy possible. The function of this phosphatase and how its inhibition leads to toxicity concern us to this date. Initial research from patients and animal models implicated a panoply of factors contributing to hypertension and vasculopathy. Subsequently, the role of calcineurin in regulating the effective fluid volume, sodium reabsorption, and potassium and hydrogen ion excretion was elucidated by investigating calcineurin inhibition. Understanding the regulatory effects of calcineurin on endothelial and vascular smooth muscle cell function has also made substantial progress. However, precisely how the increase in systemic vascular resistance arises requires further mechanistic research. CONCLUSION: Calcineurin inhibition continues to save lives; however, options to counteract the negative effects of calcineurin inhibition should be vigorously pursued.
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Calcineurina , Sistema Cardiovascular , Animales , Humanos , Calcineurina/metabolismo , Calcio/metabolismo , Proteínas de Unión a Calmodulina , Sistema Cardiovascular/metabolismo , Mamíferos , Resistencia VascularRESUMEN
The isolated perfused kidney is a classic ex vivo preparation for studying renal physiology in general and vascular function. Here, we present a protocol for assessing myogenic tone in isolated mouse kidneys as well as vasodilatory and vasoconstrictive responses, expressed as perfusion pressure. We describe steps for pre-operative preparation, kidney and renal artery isolation, and connection of renal artery with glass cannula. We then detail how to measure pressure changes in perfused kidneys and the myogenic tone. For complete details on the use and execution of this protocol, please refer to Cui et al.1.
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Riñón , Vasoconstricción , Ratones , Animales , Presión Sanguínea/fisiología , PerfusiónRESUMEN
Salt sensitivity concerns blood pressure alterations after a change in salt intake (sodium chloride). The heart is a pump, and vessels are tubes; sodium can affect both. A high salt intake increases cardiac output, promotes vascular dysfunction and capillary rarefaction, and chronically leads to increased systemic vascular resistance. More recent findings suggest that sodium also acts as an important second messenger regulating energy metabolism and cellular functions. Besides endothelial cells and fibroblasts, sodium also affects innate and adaptive immunometabolism, immune cell function, and influences certain microbes and microbiota-derived metabolites. We propose the idea that the definition of salt sensitivity should be expanded beyond high blood pressure to cellular and molecular salt sensitivity.
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Hipertensión , Sodio , Humanos , Sodio/metabolismo , Cloruro de Sodio Dietético/efectos adversos , Cloruro de Sodio Dietético/metabolismo , Células Endoteliales/metabolismo , Cloruro de Sodio , Presión Sanguínea/fisiologíaRESUMEN
DNA nanotechnology has enabled the creation of supramolecular machines, whose shape and function are inspired from traditional mechanical engineering as well as from biological examples. As DNA inherently is a highly charged biopolymer, the external application of electric fields provides a versatile, computer-programmable way to control the movement of DNA-based machines. However, the details of the electrohydrodynamic interactions underlying the electrical manipulation of these machines are complex, as the influence of their intrinsic charge, the surrounding cloud of counterions, and the effect of electrokinetic fluid flow have to be taken into account. In this work, we identify the relevant effects involved in this actuation mechanism by determining the electric response of an established DNA-based nanorobotic arm to varying design and operation parameters. Borrowing an approach from single-molecule biophysics, we determined the electrical torque exerted on the nanorobotic arms by analyzing their thermal fluctuations when oriented in an electric field. We analyze the influence of various experimental and design parameters on the "actuatability" of the nanostructures and optimize the generated torque according to these parameters. Our findings give insight into the physical processes involved in the actuation mechanism and provide general guidelines that aid in designing and efficiently operating electrically driven nanorobotic devices made from DNA.
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ADN , Nanoestructuras , ADN/química , Nanoestructuras/química , Nanotecnología , TorqueRESUMEN
PURPOSE: Remission of type 2 diabetes (T2D) can be achieved by many, but not all, people following bariatric/metabolic surgery. The mechanisms underlying T2D remission remain incompletely understood. This observational study aimed to identify novel weight-loss independent clinical, metabolic and genetic factors that associate with T2D remission using comprehensive phenotyping. MATERIALS AND METHODS: Ten patients without T2D remission (non-remitters) were matched to 10 patients with T2D remission (remitters) for age, sex, type of surgery, body weight, BMI, post-operative weight loss, duration from surgery and duration of T2D. Detailed body composition assessed using magnetic resonance imaging, gut hormones, serum metabolomics, insulin sensitivity, and genetic risk scores for T2D and anthropometric traits were assessed. RESULTS: Remitters had significantly greater ß-cell function and circulating acyl ghrelin levels, but lower visceral adipose tissue (VAT): subcutaneous adipose tissue (SAT) ratio than non-remitters. Branched-chain amino acids (BCAAs) and VLDL particle size were the most discriminant metabolites between groups. A significant positive correlation between, VAT area, VAT:SAT ratio and circulating levels of BCAAs was observed, whereas a significant negative correlation between BCAAs and ß-cell function was revealed. CONCLUSION: We highlight a potentially novel relationship between VAT and BCAAs, which may play a role in glucoregulatory control. Improvement in ß-cell function, and the role ghrelin plays in its recovery, is likely another key factor influencing T2D remission post-surgery. These findings suggest that adjunctive approaches that target VAT loss and restoration of BCAA metabolism might achieve higher rates of long-term T2D remission post-surgery.
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Cirugía Bariátrica , Diabetes Mellitus Tipo 2 , Obesidad Mórbida , Humanos , Ghrelina , Obesidad Mórbida/cirugía , Resultado del Tratamiento , Pérdida de Peso , BiomarcadoresRESUMEN
The good old days were not good, at least in terms of treating patients with type 2 diabetes. In the 1960s, the development of a radioimmunoassay for insulin permitted determination of the distinguishing features of type 1 and type 2 diabetes. The latter was treated with sulfonylureas and then phenformin, although the mechanisms of action at the time were unknown. The University Group Diabetes Program was a randomized controlled trial experienced by my medical generation, and the results were dramatic, both medically and legally. Next came the thiazolidinediones. All compounds were associated with weight gain and any end point benefits were uncertain. Nevertheless, basic science explained how glucose is sensed and even found a home for sulfonylureas in some patients. Next came the boom in renin-angiotensin-aldosterone system blockade, sacred ground for many, albeit the benefits were less than astounding. Other wonder drugs came and went. Over the decades, great strides were made in defining the pathology of diabetic renal disease, which is appropriate because the condition has become a primary cause of end-stage renal failure. Nonetheless, recent advances have turned around a depressing situation and are reasons for optimism. We now have compounds that actually could help patients with type 2 diabetes. One hundred years after insulin's introduction, it is high time.
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Diabetes Mellitus Tipo 2 , Nefropatías Diabéticas , Insulinas , Fallo Renal Crónico , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/tratamiento farmacológico , Sistema Renina-Angiotensina , Fallo Renal Crónico/complicaciones , Insulinas/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Synthetic gene networks in mammalian cells are currently limited to either protein-based transcription factors or RNA-based regulators. Here, we demonstrate a regulatory approach based on circular single-stranded DNA (Css DNA), which can be used as an efficient expression vector with switchable activity, enabling gene regulation in mammalian cells. The Css DNA is transformed into its double-stranded form via DNA replication and used as vectors encoding a variety of different proteins in a wide range of cell lines as well as in mice. The rich repository of DNA nanotechnology allows to use sort single-stranded DNA effectors to fold Css DNA into DNA nanostructures of different complexity, leading the gene expression to programmable inhibition and subsequently re-activation via toehold-mediated strand displacement. The regulatory strategy from Css DNA can thus expand the molecular toolbox for the realization of synthetic regulatory networks with potential applications in genetic diagnosis and gene therapy.
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ADN de Cadena Simple , ADN , Animales , Ratones , ADN de Cadena Simple/genética , ADN/metabolismo , Replicación del ADN , Proteínas de Unión al ADN/metabolismo , Expresión Génica , Mamíferos/genéticaRESUMEN
Second-order electrokinetic flow around colloidal particles caused by concentration polarization electro-osmosis (CPEO) can result in a phoretic motion of asymmetric particle dimers in a homogeneous AC electrical field, which we refer to as concentration polarization electro-phoresis (CPEP). To demonstrate this actuation mechanism, we created particle dimers from micron-sized silica spheres with sizes 1.0 µm and 2.1 µm by connecting them with DNA linker molecules. The dimers can be steered along arbitrarily chosen paths within a 2D plane by controlling the orientation of the AC electric field in a fluidic chamber with the joystick of a gamepad. Further utilizing induced dipole-dipole interactions, we demonstrate that particle dimers can be used to controllably pick up monomeric particles and release them at any desired position, and also to assemble several particles into groups. Systematic experiments exploring the dependence of the dimer migration speed on the electric field strength, frequency, and buffer composition align with the theoretical framework of CPEO and provide parameter ranges for the operation of our microrobots. Furthermore, experiments with a variety of asymmetric particles, such as fragmented ceramic, borosilicate glass, acrylic glass, agarose gel, and ground coffee particles, as well as yeast cells, demonstrate that CPEP is a generic phenomenon that can be expected for all charged dielectric particles.
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BACKGROUND: Oxylipins, the oxidative metabolites of polyunsaturated fatty acids (PUFAs), serve as key mediators of oxidative stress, inflammatory responses, and vasoactive reactions in vivo. Our previous work has established that hemodialysis affects both long chain fatty acids (LCFAs) and oxylipins in plasma and erythrocytes to varying degrees, which may be responsible for excess cardiovascular complications in end-stage renal disease. In this study, we aimed to determine changes in blood oxylipins during cardiopulmonary bypass (CPB) in patients undergoing cardiac surgery to identify novel biomarkers and potential metabolites of CPB-related complications. We tested the hypothesis that CPB would differentially affect plasma oxylipins and erythrocytes oxylipins. METHODS: We conducted a prospective observational study of 12 patients undergoing elective cardiac surgery with expected CPB procedure. We collected venous and arterial blood samples before CPB, 15 and 45 min after the start of CPB, and 60 min after the end of CPB, respectively. Oxylipins profiling in plasma and erythrocytes was achieved using targeted HPLC-MS mass spectrometry. RESULTS: Our results revealed that most venous plasma diols and hydroxy- oxylipins decreased after CPB initiation, with a continuous decline until the termination of CPB. Nevertheless, no statistically significant alterations were detected in erythrocytes oxylipins at all time points. CONCLUSIONS: CPB decreases numerous diols and hydroxy oxylipins in blood plasma, whereas no changes in erythrocytes oxylipins are observed during this procedure in patients undergoing cardiac surgery. As lipid mediators primarily responsive to CPB, plasma diols and hydroxy oxylipins may serve as potential key biomarkers for CPB-related complications.