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Opioid use disorder (OUD) is a neuropsychological disease that has a devastating impact on public health. Substantial individual differences in vulnerability exist, the neurobiological substrates of which remain unclear. To address this question, we investigated genome-wide gene transcription (RNA-seq) and chromatin accessibility (ATAC-seq) in the medial prefrontal cortex (mPFC) of male and female rats exhibiting differential vulnerability in behavioral paradigms modeling different phases of OUD: Withdrawal-Induced Anhedonia (WIA), Demand, and Reinstatement. Ingenuity Pathway Analysis (IPA) of RNA-seq revealed greater changes in canonical pathways in Resilient (vs. Saline) rats in comparison to Vulnerable (vs. Saline) rats across 3 paradigms, suggesting brain adaptations that might contribute to resilience to OUD across its trajectory. Analyses of gene networks and upstream regulators implicated processes involved in oligodendrocyte maturation and myelination in WIA, neuroinflammation in Demand, and metabolism in Reinstatement. Motif analysis of ATAC-seq showed changes in chromatin accessibility to a small set of transcription factor (TF) binding sites as a function either of opioid exposure (i.e., morphine versus saline) generally or of individual vulnerability specifically. Some of these were shared across the 3 paradigms and others were unique to each. In conclusion, we have identified changes in biological pathways, TFs, and their binding motifs that vary with paradigm and OUD vulnerability. These findings point to the involvement of distinct transcriptional and epigenetic mechanisms in response to opioid exposure, vulnerability to OUD, and different stages of the disorder.
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Methylene blue (MB) has been shown to reduce mortality and morbidity in vasoplegic patients after cardiac surgery. Though MB is considered to be safe, extravasation of MB leading to cutaneous toxicity has been reported. In this study, we sought to characterize MB-induced cutaneous toxicity and investigate the underlying mechanisms. To induce MB-induced cutaneous toxicity, we injected 64 adult male Sprague-Dawley rates with 200 µL saline (vehicle) or 1%, 0.1%, or 0.01% MB in the plantar hind paws. Paw swelling, skin histologic changes, and heat and mechanical hyperalgesia were measured. Injection of 1%, but not 0.1% or 0.01% MB, produced significant paw swelling compared to saline. Injection of 1% MB produced heat hyperalgesia but not mechanical hyperalgesia. Pain behaviors were unchanged following injections of 0.1% or 0.01% MB. Global transcriptomic analysis by RNAseq identified 117 differentially expressed genes (111 upregulated, 6 downregulated). Ingenuity Pathway Analysis showed an increased quantity of leukocytes, increased lipids, and decreased apoptosis of myeloid cells and phagocytes with activation of IL-1ß and Fos as the two major regulatory hubs. qPCR showed a 16-fold increase in IL-6 mRNA. Thus, using a novel rat model of MB-induced cutaneous toxicity, we show that infiltration of 1% MB into cutaneous tissue causes a dose-dependent pro-inflammatory response, highlighting potential roles of IL-6, IL-1ß, and Fos. Thus, anesthesiologists should administer dilute MB intravenously through peripheral venous catheters. Higher concentrations of MB (1%) should be administered through a central venous catheter to minimize the risk of cutaneous toxicity.
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Modelos Animales de Enfermedad , Hiperalgesia , Inflamación , Azul de Metileno , Ratas Sprague-Dawley , Piel , Animales , Masculino , Azul de Metileno/farmacología , Azul de Metileno/administración & dosificación , Hiperalgesia/patología , Hiperalgesia/inducido químicamente , Inflamación/patología , Inflamación/inducido químicamente , Piel/efectos de los fármacos , Piel/patología , Relación Dosis-Respuesta a Droga , Calor , Ratas , Interleucina-1beta/metabolismo , Interleucina-1beta/genéticaRESUMEN
Over 79 % of 6.3 billion tonnes of plastics produced from 1950 to 2015 have been disposed in landfills or found their way to the oceans, where they will reside for up to hundreds of years before being decomposed bringing upon significant dangers to our health and ecosystems. Plastic photoreforming offers an appealing alternative by using solar energy and water to transform plastic waste into value-added chemical commodities, while simultaneously producing green hydrogen via the hydrogen evolution reaction. This review aims to provide an overview of the underlying principles of emerging plastic photoreforming technologies, highlight the challenges associated with experimental protocols and performance assessments, discuss recent global breakthroughs on the photoreforming of plastics, and propose perspectives for future research. A critical assessment of current plastic photoreforming studies shows a lack of standardised conditions, hindering comparison amongst photocatalyst performance. Guidelines to establish a more accurate evaluation of materials and systems are proposed, with the aim to facilitate the translation of promising fundamental discovery in photocatalysts design.
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Neonatal encephalopathy (NE) impairs white matter development and results in long-term neurodevelopmental deficits. Leveraging prior findings of altered neuronal proteins carried by brain-derived extracellular vesicles (EVs) that are marked by a neural-specific cell surface glycoprotein Contactin-2 (CNTN2) in NE infants, the present study aimed to determine the correlation between brain and circulating CNTN2+-EVs and whether NE alters circulating CNTN2+-EV levels in mice. Brain tissue and plasma were collected from postnatal day (P)7, 10, 11, 15 mice to determine the baseline CNTN2 correlation between these two compartments (n = 4-7/time point/sex). NE was induced in P10 pups. Brain and plasma samples were collected at 1, 3, 6, 24, and 120 h (n = 4-8/time point/sex). CNTN2 from brain tissue and plasma EVs were quantified using ELISA. ANOVA and linear regression analyses were used to evaluate changes and correlations between brain and plasma CNTN2+-EVs. In baseline experiments, CNTN2 in brain tissue and plasma EVs peaked at P10 with no sex-difference. Brain and plasma CNTN2+-EV showed a positive correlation across early postnatal ages. NE pups showed an elevated CNTN2 in brain tissue and EVs at 1 h and only in brain tissue at 24 h. NE also abolished the positive plasma-brain correlation. The findings establish a link for central CNTN2 and its release into circulation during early postnatal life. The immediate elevation and release of CNTN2 following NE highlight a potential molecular response shortly after a brain injurious event. Our findings further support the utility of circulating brain-derived EVs as a possible bioindicator of NE.
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Animales Recién Nacidos , Encéfalo , Contactina 2 , Vesículas Extracelulares , Hipoxia-Isquemia Encefálica , Animales , Vesículas Extracelulares/metabolismo , Hipoxia-Isquemia Encefálica/metabolismo , Hipoxia-Isquemia Encefálica/patología , Encéfalo/metabolismo , Femenino , Masculino , Ratones , Contactina 2/metabolismo , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: Iron deficiency (ID) during the fetal-neonatal period results in long-term neurodevelopmental impairments associated with pervasive hippocampal gene dysregulation. Prenatal choline supplementation partially normalizes these effects, suggesting an interaction between iron and choline in hippocampal transcriptome regulation. To understand the regulatory mechanisms, we investigated epigenetic marks of genes with altered chromatin accessibility (ATAC-seq) or poised to be repressed (H3K9me3 ChIP-seq) in iron-repleted adult rats having experienced fetal-neonatal ID exposure with or without prenatal choline supplementation. RESULTS: Fetal-neonatal ID was induced by limiting maternal iron intake from gestational day (G) 2 through postnatal day (P) 7. Half of the pregnant dams were given supplemental choline (5.0 g/kg) from G11-18. This resulted in 4 groups at P65 (Iron-sufficient [IS], Formerly Iron-deficient [FID], IS with choline [ISch], and FID with choline [FIDch]). Hippocampi were collected from P65 iron-repleted male offspring and analyzed for chromatin accessibility and H3K9me3 enrichment. 22% and 24% of differentially transcribed genes in FID- and FIDch-groups, respectively, exhibited significant differences in chromatin accessibility, whereas 1.7% and 13% exhibited significant differences in H3K9me3 enrichment. These changes mapped onto gene networks regulating synaptic plasticity, neuroinflammation, and reward circuits. Motif analysis of differentially modified genomic sites revealed significantly stronger choline effects than early-life ID and identified multiple epigenetically modified transcription factor binding sites. CONCLUSIONS: This study reveals genome-wide, stable epigenetic changes and epigenetically modifiable gene networks associated with specific chromatin marks in the hippocampus, and lays a foundation to further elucidate iron-dependent epigenetic mechanisms that underlie the long-term effects of fetal-neonatal ID, choline, and their interactions.
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Deficiencias de Hierro , Hierro , Embarazo , Femenino , Animales , Ratas , Masculino , Hierro/metabolismo , Cromatina/genética , Cromatina/metabolismo , Animales Recién Nacidos , Ratas Sprague-Dawley , Epigénesis Genética , Colina/farmacología , Colina/metabolismo , HipocampoRESUMEN
Background: Addressing child disruptive behavior in low and middle-income countries (LMICs) is challenging. Therapist-facilitated, multisession, brief, online group parent training offers hope for mitigating this issue. However, trials, particularly in Asia, are limited. Objective: This study primarily assessed the effectiveness of Brief Behavior Parent Training Vietnam (BBPTV) in reducing child disruptive behavior. Method: This study was a randomized controlled trial involving 109 Vietnamese parents (mean age = 34.1, 96 % were mothers) of preschool children displaying ongoing disruptive behaviors. Interventions included the BBPTV group (n = 56) receiving a therapist-facilitated, four-session program conducted through online group meetings and the care-as-usual (CAU) group (n = 53) having a 15 min individual online consultation. Primary outcomes, assessed online at two and six months postintervention, encompassed the intensity and frequency of children's disruptive problems. Secondary outcomes involved parenting practices, coercive interactions, marital conflicts, parenting self-efficacy, and parental mental health. Results: In contrast to CAU, the BBPTV group showed lower child disruptive intensity, reduced parent-child coercive interactions, and diminished marital conflicts, with a higher score in involving parenting two months post-intervention. Six months postintervention, BBPTV also exhibited significantly lower scores in child disruptive intensity and problems, harsh parenting, and coercive processes compared to CAU. Conclusions: The therapist-facilitated, four-session, internet-delivered group parent intervention resulted in superior and sustained improvements in child disruptive behavior, parenting practices, and parent-child coercive interaction compared to usual care, highlighting the potential for online BBPT to extend mental health care in Vietnam and other LMICs.
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BACKGROUND: Developmental iron deficiency (ID) is associated with long-term cognitive and affective behavioral impairments in humans. Preclinical studies have shown that developmental ID has short- and long-term effects on gene regulation. Prenatal choline supplementation partially rescues early-life ID-induced cognitive deficits in adult male rats. OBJECTIVES: To identify acute and long-term changes in biological processes regulated by developmental ID and modifiable by choline. METHODS: This study compares the hippocampal transcriptomes of postnatal day (P) 15 iron-deficient (acute) and P65 formerly ID (persistent) rats with or without prenatal choline treatment. Pregnant rats were fed an ID (4 mg/kg Fe) or iron-sufficient (IS) (200 mg/kg Fe) diet from gestational day (G) 2 to P7 with or without choline supplementation (5 g/kg choline) from G11 to G18. Hippocampi were collected from P15 or P65 offspring and analyzed for gene expression by RNA sequencing. RESULTS: Developmental ID-induced changes suggested modified activity of oxidative phosphorylation and fatty acid metabolism. Prenatal choline supplementation induced robust changes in gene expression, particularly in iron-deficient animals, where it partially mitigated the early-life ID-dysregulated genes. Choline supplementation also altered the hippocampal transcriptome in the IS rats, with indications for both beneficial and adverse effects. CONCLUSIONS: This study provided global assessments of gene expression regulated by iron and choline. Our new findings highlight genes responding to iron or choline treatments, including a potentially novel choline-regulated transporter (IPO7), with shared effects on neuroinflammation in the male rat hippocampus.
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Deficiencias de Hierro , Efectos Tardíos de la Exposición Prenatal , Embarazo , Humanos , Femenino , Ratas , Animales , Masculino , Hierro/metabolismo , Transcriptoma , Colina , Animales Recién Nacidos , Ratas Sprague-Dawley , Vitaminas/farmacología , Hipocampo/metabolismoRESUMEN
Active nematics are dense systems of rodlike particles that consume energy to drive motion at the level of the individual particles. They exist in natural systems like biological tissues and artificial materials such as suspensions of self-propelled colloidal particles or synthetic microswimmers. Active nematics have attracted significant attention in recent years due to their spectacular nonequilibrium collective spatiotemporal dynamics, which may enable applications in fields such as robotics, drug delivery, and materials science. The director field, which measures the direction and degree of alignment of the local nematic orientation, is a crucial characteristic of active nematics and is essential for studying topological defects. However, determining the director field is a significant challenge in many experimental systems. Although director fields can be derived from images of active nematics using traditional imaging processing methods, the accuracy of such methods is highly sensitive to the settings of the algorithms. These settings must be tuned from image to image due to experimental noise, intrinsic noise of the imaging technology, and perturbations caused by changes in experimental conditions. This sensitivity currently limits automatic analysis of active nematics. To address this, we developed a machine learning model for extracting reliable director fields from raw experimental images, which enables accurate analysis of topological defects. Application of the algorithm to experimental data demonstrates that the approach is robust and highly generalizable to experimental settings that are different from those in the training data. It could be a promising tool for investigating active nematics and may be generalized to other active matter systems.
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Coupling the hydrogen evolution reaction with plastic waste photoreforming provides a synergistic path for simultaneous production of green hydrogen and recycling of post-consumer products, two major enablers for establishment of a circular economy. Graphitic carbon nitride (g-C3 N4 ) is a promising photocatalyst due to its suitable optoelectronic and physicochemical properties, and inexpensive fabrication. Herein, a mechanistic investigation of the structure-activity relationship of g-C3 N4 for poly(ethylene terephthalate) (PET) photoreforming is reported by carefully controlling its fabrication from a subset of earth-abundant precursors, such as dicyandiamide, melamine, urea, and thiourea. These findings reveal that melamine-derived g-C3 N4 with 3 wt.% Pt has significantly higher performance than alternative derivations, achieving a maximum hydrogen evolution rate of 7.33 mmolH2 gcat -1 h-1 , and simultaneously photoconverting PET into valuable organic products including formate, glyoxal, and acetate, with excellent stability for over 30 h of continuous production. This is attributed to the higher crystallinity and associated chemical resistance of melamine-derived g-C3 N4 , playing a major role in stabilization of its morphology and surface properties. These new insights on the role of precursors and structural properties in dictating the photoactivity of g-C3 N4 set the foundation for the further development of photocatalytic processes for combined green hydrogen production and plastic waste reforming.
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PURPOSE: To determine the retinal transcriptomic differences underlying the oxygen-induced retinopathy phenotypes between Sprague Dawley rat pups from two commonly used commercial vendors. This will allow us to discover genes and pathways that may be related to differences in disease severity in similarly aged premature babies and suggest possible new treatment approaches. METHODS: We analyzed retinal vascular morphometry and transcriptomes from Sprague Dawley rat pups from Charles River Laboratories and Envigo (previously Harlan). Room air control and oxygen-induced retinopathy groups were compared. Oxygen-induced retinopathy was induced with the rat 50/10 model. RESULTS: Pups from Charles River Laboratories developed a more severe oxygen-induced retinopathy phenotype, with 3.6-fold larger percent avascular area at P15 and twofold larger % neovascular area at P20 than pups from Envigo. Changes in retinal transcriptomes of rat pups from both vendors were substantial at baseline and in response to oxygen-induced retinopathy. Baseline differences centered on activated pathways of neuronal development in Charles River Laboratories pups. In response to oxygen-induced retinopathy, during the neovascular phase, retinas from Charles River Laboratories pups exhibited activation of pathways regulating necrosis, neuroinflammation, and interferon signaling, supporting the observed increase of neovascularization. Conversely, retinas from Envigo pups showed decreased necrosis and increased focal adhesion kinase signaling, supporting more normal vascular development. Comparing oxygen-induced retinopathy transcriptomes at P15 to those at P20, canonical pathways such as phosphate and tensin homolog, interferon, and coordinated lysosomal expression and regulation element signaling were identified, highlighting potential novel mechanistic targets for future research. CONCLUSION: Transcriptomic profiles differ substantially between rat pup retinas from Charles River Laboratories and Envigo at baseline and in response to oxygen-induced retinopathy, providing insight into vascular morphologic differences. Comparing transcriptomes identified new pathways for further research in oxygen-induced retinopathy pathogenesis and increased scientific rigor of this model.
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Neovascularización Retiniana , Retinopatía de la Prematuridad , Ratas , Animales , Oxígeno/toxicidad , Ratas Sprague-Dawley , Retinopatía de la Prematuridad/inducido químicamente , Retinopatía de la Prematuridad/genética , Transcriptoma , Neovascularización Retiniana/genética , Neovascularización Retiniana/patología , Animales Recién Nacidos , Necrosis/complicaciones , Necrosis/patología , Interferones , Modelos Animales de Enfermedad , Vasos Retinianos/patologíaRESUMEN
Nanoscale heterojunction networks are increasingly regarded as promising functional materials for a variety of optoelectronic and photocatalytic devices. Despite their superior charge-carrier separation efficiency, a major challenge remains in the optimization of their surface properties, with surface defects playing a major role in charge trapping and recombination. Here, we report the effective engineering of the photocatalytic properties of nanoscale heterojunction networks via deep ultraviolet photoactivation throughout their cross-section. For the first time, in-depth XPS analysis of very thick (â¼10 µm) NixOy-ZnO films reveals localized p-n nanoheterojunctions with tunable oxygen vacancies (Vo) originating from both NixOy and ZnO nanocrystals. Optimizing the amount of oxygen vacancies leads to a 30-fold increase in the photochemoresistive response of these networks, enabling the detection of representative analyte concentrations down to 2 and 20 ppb at an optimal temperature of 150 °C and room temperature, respectively. Density functional theory calculations reveal that this performance enhancement is presumably due to an 80% increase in the analyte adsorption energy. This flexible nanofabrication approach in conjunction with straightforward vacancy control via photoactivation provides an effective strategy for engineering the photocatalytic activity of porous metal oxide semiconductor networks with applications in chemical sensors, photodetectors, and photoelectrochemical cells.
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Transgenic expression of proteins in plants is central to research and biotechnology, and, often, it is desirable to obtain this expression without altering the nuclear or plastid genomes. Thus, expression vectors based on plant viruses that infect multiple cells are useful; furthermore, they are also advantageous for studies of the life cycle of the virus itself. Here, we report the development of an expression vector based on a Turnip vein-clearing virus (TVCV), a tobamovirus known to easily infect two model plants, Nicotiana benthamiana, and Arabidopsis thaliana. Avoiding restriction digestion, we utilized a restriction-ligation-independent cloning approach to construct an infectious cDNA clone of TVCV from the viral RNA and then to convert this clone to a gene expression vector adapted for Gateway-based recombination cloning for transgene insertion. The functionality of the resulting vector, designated pTVCV-DEST, was validated by the expression of an autofluorescent reporter transgene following agroinoculation of the target plant.
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Implementation of proton-exchange membrane water electrolyzers for large-scale sustainable hydrogen production requires the replacement of scarce noble-metal anode electrocatalysts with low-cost alternatives. However, such earth-abundant materials often exhibit inadequate stability and/or catalytic activity at low pH, especially at high rates of the anodic oxygen evolution reaction (OER). Here, the authors explore the influence of a dielectric nanoscale-thin oxide layer, namely Al2 O3 , SiO2 , TiO2 , SnO2 , and HfO2 , prepared by atomic layer deposition, on the stability and catalytic activity of low-cost and active but insufficiently stable Co3 O4 anodes. It is demonstrated that the ALD layers improve both the stability and activity of Co3 O4 following the order of HfO2 > SnO2 > TiO2 > Al2 O3 , SiO2 . An optimal HfO2 layer thickness of 12 nm enhances the Co3 O4 anode durability by more than threefold, achieving over 42 h of continuous electrolysis at 10 mA cm-2 in 1 m H2 SO4 electrolyte. Density functional theory is used to investigate the superior performance of HfO2 , revealing a major role of the HfO2 |Co3 O4 interlayer forces in the stabilization mechanism. These insights offer a potential strategy to engineer earth-abundant materials for low-pH OER catalysts with improved performance from earth-abundant materials for efficient hydrogen production.
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Unlocking the potential of the hydrogen economy is dependent on achieving green hydrogen (H2 ) production at competitive costs. Engineering highly active and durable catalysts for both oxygen and hydrogen evolution reactions (OER and HER) from earth-abundant elements is key to decreasing costs of electrolysis, a carbon-free route for H2 production. Here, a scalable strategy to prepare doped cobalt oxide (Co3 O4 ) electrocatalysts with ultralow loading, disclosing the role of tungsten (W), molybdenum (Mo), and antimony (Sb) dopants in enhancing OER/HER activity in alkaline conditions, is reported. In situ Raman and X-ray absorption spectroscopies, and electrochemical measurements demonstrate that the dopants do not alter the reaction mechanisms but increase the bulk conductivity and density of redox active sites. As a result, the W-doped Co3 O4 electrode requires ≈390 and ≈560 mV overpotentials to reach ±10 and ±100 mA cm-2 for OER and HER, respectively, over long-term electrolysis. Furthermore, optimal Mo-doping leads to the highest OER and HER activities of 8524 and 634 A g-1 at overpotentials of 0.67 and 0.45 V, respectively. These novel insights provide directions for the effective engineering of Co3 O4 as a low-cost material for green hydrogen electrocatalysis at large scales.
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BACKGROUND: Fetal-neonatal iron deficiency (ID) causes long-term neurocognitive and affective dysfunctions. Clinical and preclinical studies have shown that early-life ID produces sex-specific effects. However, little is known about the molecular mechanisms underlying these early-life ID-induced sex-specific effects on neural gene regulation. OBJECTIVE: To illustrate sex-specific transcriptome alterations in adult rat hippocampus induced by fetal-neonatal ID and prenatal choline treatment. METHODS: Pregnant rats were fed an iron-deficient (4 mg/kg Fe) or iron-sufficient (200 mg/kg Fe) diet from gestational day (G) 2 to postnatal day (P) 7 with or without choline supplementation (5 g/kg choline) from G11-18. Hippocampi were collected from P65 offspring of both sexes and analyzed for changes in gene expression. RESULTS: Both early-life ID and choline treatment induced transcriptional changes in adult female and male rat hippocampi. Both sexes showed ID-induced alterations in gene networks leading to enhanced neuroinflammation. In females, ID-induced changes indicated enhanced activity of oxidative phosphorylation and fatty acid metabolism, which were contrary to the ID effects in males. Prenatal choline supplementation induced the most robust changes in gene expression, particularly in iron-deficient animals where it partially rescued ID-induced dysregulation. Choline supplementation also altered hippocampal transcriptome in iron-sufficient rats with indications for both beneficial and adverse effects. CONCLUSIONS: This study provided unbiased global assessments of gene expression regulated by iron and choline in a sex-specific manner, with greater effects in female than male rats. Our new findings highlight potential sex-specific gene networks regulated by iron and choline for further investigation.
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Deficiencias de Hierro , Efectos Tardíos de la Exposición Prenatal , Embarazo , Humanos , Animales , Ratas , Masculino , Femenino , Colina/farmacología , Colina/metabolismo , Transcriptoma , Animales Recién Nacidos , Ratas Sprague-Dawley , Hierro/metabolismo , Vitaminas/farmacología , Hipocampo/metabolismo , Efectos Tardíos de la Exposición Prenatal/metabolismoRESUMEN
Histone ubiquitylation/deubiquitylation plays a major role in the epigenetic regulation of gene expression. In plants, OTLD1, a member of the ovarian tumor (OTU) deubiquitinase family, deubiquitylates histone 2B and represses the expression of genes involved in growth, cell expansion, and hormone signaling. OTLD1 lacks the intrinsic ability to bind DNA. How OTLD1, as well as most other known plant histone deubiquitinases, recognizes its target genes remains unknown. Here, we show that Arabidopsis transcription factor LSH10, a member of the ALOG protein family, interacts with OTLD1 in living plant cells. Loss-of-function LSH10 mutations relieve the OTLD1-promoted transcriptional repression of the target genes, resulting in their elevated expression, whereas recovery of the LSH10 function results in down-regulated transcription of the same genes. We show that LSH10 associates with the target gene chromatin as well as with DNA sequences in the promoter regions of the target genes. Furthermore, without LSH10, the degree of H2B monoubiquitylation in the target promoter chromatin increases. Hence, our data suggest that OTLD1-LSH10 acts as a co-repressor complex potentially representing a general mechanism for the specific function of plant histone deubiquitinases at their target chromatin.
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Proteínas de Arabidopsis , Arabidopsis , Proteasas de Cisteína , Histonas/genética , Histonas/metabolismo , Arabidopsis/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Epigénesis Genética , Cromatina/genética , Cromatina/metabolismo , Regulación de la Expresión Génica , Enzimas Desubicuitinizantes/genética , Enzimas Desubicuitinizantes/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteasas de Cisteína/genética , Proteasas de Cisteína/metabolismoRESUMEN
BACKGROUND AND PURPOSE: CaV1.2 channels contribute to action potential upstroke in pacemaker cells, plateau potential in working myocytes, and initiate excitation-contraction coupling. Understanding drug action on CaV1.2 channels may inform potential impact on cardiac function. However, literature shows large degrees of variability between CaV1.2 pharmacology generated by different laboratories, casting doubt regarding the utility of these data to predict or interpret clinical outcomes. This study examined experimental factors that may impact CaV1.2 pharmacology. EXPERIMENTAL APPROACH: Whole cell recordings were made on CaV1.2 overexpression cells. Current was evoked using a "step-step-ramp" waveform that elicited a step and a ramp current. Experimental factors examined were: 1) near physiological vs. room temperature for recording, 2) drug inhibition of the step vs. the ramp current, and 3) Ca2+ vs. Ba2+ as the charge carrier. Eight drugs were studied. KEY RESULTS: CaV1.2 current exhibited prominent rundown, exquisite temperature sensitivity, and required a high degree of series resistance compensation to optimize voltage control. Temperature-dependent effects were examined for verapamil and methadone. Verapamil's block potency shifted by up to 4X between room to near physiological temperature. Methadone exhibited facilitatory and inhibitory effects at near physiological temperature, and only inhibitory effect at room temperature. Most drugs inhibited the ramp current more potently than the step current-a preference enhanced when Ba2+ was the charge carrier. The slopes of the concentration-inhibition relationships for many drugs were shallow, temperature-dependent, and differed between the step and the ramp current. CONCLUSIONS AND IMPLICATIONS: All experimental factors examined affected CaV1.2 pharmacology. In addition, whole cell CaV1.2 current characteristics-rundown, temperature sensitivity, and impact of series resistance-are also factors that can impact pharmacology. Drug effects on CaV1.2 channels appear more complex than simple pore block mechanism. Normalizing laboratory-specific approaches is key to improve inter-laboratory data reproducibility. Releasing original electrophysiology records is essential to promote transparency and enable the independent evaluation of data quality.
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Canales de Calcio Tipo L , Excipientes , Canales de Calcio Tipo L/fisiología , Temperatura , Reproducibilidad de los Resultados , Verapamilo/farmacología , MetadonaRESUMEN
BACKGROUND: Renal hypoperfusion is one of the most common causes of acute kidney injury (AKI), especially in shock and perioperative patients. An optimal blood pressure (BP) target to prevent AKI remains undetermined. We conducted a systematic review and meta-analysis of available randomized clinical trial (RCT) results to address this knowledge gap. METHODS: From inception to May 13, 2022, we searched Ovid Medline, EMBASE, Cochrane Library, SCOPUS, clinicaltrials.gov, and WHO ICTRP for RCTs comparing higher BP target versus normotension in hemodynamically unstable patients (shock, post-cardiac arrest, or surgery patients). The outcomes of interest were post-intervention AKI rate and renal replacement therapy (RRT) rate. Two investigators independently screened the citations and reviewed the full texts for eligible studies according to a predefined form. RESULTS: Twelve trials were included, enrolling a total of 5759 participants, with shock, non-cardiac, and cardiac surgery patients accounting for 3282 (57.0%), 1687 (29.3%) and 790 (13.7%) patients, respectively. Compared to lower mean arterial blood pressure (MAP) targets that served as normotension, targeting higher MAP had no significant effect on AKI rates in shock (RR [95% CI] = 1.10 [0.93, 1.29]), in cardiac-surgery (RR [95% CI] = 0.87 [0.73, 1.03]) and non-cardiac surgery patients (RR [95% CI] = 1.25 [0.98, 1.60]) using random-effects meta-analyses. In shock patients with premorbid hypertension, however, targeting MAP above 70 mmHg resulted in significantly lower RRT risks, RR [95%CI] = 1.20 [1.03, 1.41], p < 0.05. CONCLUSIONS: Targeting a higher MAP in shock or perioperative patients may not be superior to normotension, except in shock patients with premorbid hypertension. Further studies are needed to assess the effects of a high MAP target to preventing AKI in hypertensive patients across common settings of hemodynamic instability. Trial registration This systematic review has been registered on PROSPERO ( CRD42021286203 ) on November 19, 2021, prior to data extraction and analysis.
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Lesión Renal Aguda , Hipertensión , Humanos , Presión Sanguínea , Ensayos Clínicos Controlados Aleatorios como Asunto , Terapia de Reemplazo Renal/métodos , Lesión Renal Aguda/prevención & controlRESUMEN
Functional compensation in response to gene dysfunction is a fascinating phenomenon that allows mutated viruses to regain the capabilities of their wild-type parental strains. In this study, we isolated mutants of tobacco mosaic virus capable of CP-independent systemic movement. These gain-of-function mutants lacked the 16 C-terminal amino acids of the movement protein (MP). Whereas this deletion did not affect the cell-to-cell movement of MP, it dramatically enhanced the viral genomic RNA levels and MP accumulation within the infected cells and altered the subcellular localization of MP from exclusively plasmodesmata (PD) to both PD and plasma membrane. The adapted defective virus suppressed the expression of the ethylene pathway and phloem-associated resistance factors in the inoculated leaves. These findings demonstrate the potential for plant viral MPs to gain a new function that allows viral genomes to move systemically in the absence of the natural viral factor that mediates this spread.
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Epigenetic regulation of gene expression is commonly affected by histone modifying enzymes (HMEs) that generate heterochromatic or euchromatic histone marks for transcriptional repression or activation, respectively. HMEs are recruited to their target chromatin by transcription factors (TFs). Thus, detecting and characterizing direct interactions between HMEs and TFs are critical for understanding their function and specificity better. These studies would be more biologically relevant if performed in vivo within living tissues. Here, a protocol is described for visualizing interactions in plant leaves between a plant histone deubiquitinase and a plant transcription factor using fluorescence resonance energy transfer (FRET), which allows the detection of complexes between protein molecules that are within <10 nm from each other. Two variations of the FRET technique are presented: SE-FRET (sensitized emission) and AB-FRET (acceptor bleaching), in which the energy is transferred non-radiatively from the donor to the acceptor or emitted radiatively by the donor upon photobleaching of the acceptor. Both SE-FRET and AB-FRET approaches can be adapted easily to discover other interactions between other proteins in planta.