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1.
Front Chem ; 12: 1396123, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38725653

RESUMEN

Tetraphenylethene-based ligands with lowered symmetry are promising building blocks for the construction of novel luminescent metal-organic frameworks (MOFs). However, few examples have been reported, and predicting the ligand conformation and the dimensionality of the resulting MOF remains challenging. In order to uncover how synthetic conditions and accessible ligand conformations may affect the resulting MOF structure, four new MOF structures were synthesized under solvothermal conditions using the meta-coordinated tetraphenylethene-based ligand m-ETTC and paddlewheel SBUs composed of Co(II), Cu(II), and Zn(II). WSU-10 (WSU = Washington State University) is formed with either Zn or Cu comprising stacked psuedo-2D layers. The dimensionality of WSU-10 can be intentionally increased through the addition of pyrazine as a pillar ligand into the synthesis, forming the 3D structure WSU-11. The third structure, WSU-20, is formed by the combination of Zn or Co with m-ETTC and is intrinsically 3D without the use of a pillar ligand; interestingly, this is the result of a distortion in the paddlewheel SBU. Finally, Cu was also found to form a new structure (WSU-12), which displays an m-ETTC conformation unique from that found in the other isolated MOFs. Structural features are compared across the series and a mechanistic relationship between WSU-10 and -20 is proposed, providing insight into the factors that can encourage the generation of frameworks with increased dimensionality.

2.
Clin Psychol Rev ; 111: 102446, 2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-38796946

RESUMEN

Cognitive behavioral therapies have been identified as evidence-based treatments for anxiety-related disorders. However, data supporting the effectiveness of these treatments have been largely collected from participants with majoritized identities, potentially limiting the extent to which they can be considered "evidence-based" for clients from minoritized groups. The current review examined sociodemographic representation and quality of sociodemographic reporting in randomized controlled trials for anxiety-related disorders in the U.S. between 1993 and 2023. We conducted a systematic literature review of U.S.-based randomized controlled trials of cognitive behavioral therapies for anxiety-related disorders, extracted data on sociodemographic variables, and rated quality of reporting. Data from 55 eligible studies (N = 4492) indicated that white and female identities were overrepresented relative to the U.S. population, with variables like disability status, sexual orientation, and religious identification consistently ignored. In addition, quality of reporting was generally poor (mean = 3.6 out of 10), with many studies failing to account for demographic variables in their analyses or description of study limitations. Publication year, sample size, and NIH funding status did not significantly predict gender representation (% women), ethnoracial representation (% white), or quality of reporting. These findings underscore the importance of critically evaluating to whom "evidence-based" treatments apply and increasing diversity of clinical samples, to ensure that evidence-based treatments are inclusive. Recommendations for future research, clinical implications, and limitations are discussed.

3.
Appl Ergon ; 118: 104279, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38565008

RESUMEN

Previous research has shown there are particular patterns of license plate designs that are easier to recall. Missouri license plate patterns (AB1-C2D) somewhat diverge from what research suggests works best for recall. The current study examined whether incorporating color into license plates would improve recall, and also whether awareness or explanation of license plate formats would affect recall accuracy. Across two experiments, participants viewed license plate stimuli with and without color and attempted to recall them. The hypothesis was that incorporating color would improve recall, but the hypothesis was not supported. Results also did not show that prior exposure or explanation of formats affected accuracy. Future research should explore additional ways to improve license plate designs that would be easy to implement. Such improvements to license plate design would be useful because efforts to improve the public's awareness of formats would be expensive and likely ineffective.


Asunto(s)
Color , Recuerdo Mental , Humanos , Masculino , Femenino , Adulto , Adulto Joven , Concesión de Licencias , Concienciación , Conducción de Automóvil/psicología , Adolescente
4.
Dalton Trans ; 53(12): 5495-5506, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38415508

RESUMEN

Metal-organic frameworks (MOF) are a subclass of porous framework materials that have been used for a wide variety of applications in sensing, catalysis, and remediation. Among these myriad applications is their remarkable ability to capture substances in a variety of environments ranging from benign to extreme. Among the most common and problematic substances found throughout the world's oceans and water supplies is [UO2]2+, a common mobile ion of uranium, which is found both naturally and as a result of anthropogenic activities, leading to problematic environmental contamination. While some MOFs possess high capability for the uptake of [UO2]2+, many more of the thousands of MOFs and their modifications that have been produced over the years have yet to be studied for their ability to uptake [UO2]2+. However, studying the thousands of MOFs and their modifications presents an incredibly difficult task. As such, a way to narrow down the numbers seems imperative. Herein, we evaluate the binding behaviors as well as identify the specific binding sites of [UO2]2+ incorporated into six different Zr MOFs to elucidate specific features that improve [UO2]2+ uptake. In doing so, we also present a method for the determination and verification of these binding sites by Anomalous wide-angle X-ray scattering, X-ray fluorescence, and X-ray absorption spectroscopy. This research not only presents a way for future research into the uptake of [UO2]2+ into MOFs to be conducted but also a means to evaluate MOFs more generally for the uptake of other compounds to be applied for environmental remediation and improvement of ecosystems globally.

5.
bioRxiv ; 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38352333

RESUMEN

Respiratory syncytial virus (RSV) is a common cause of respiratory infections, causing significant morbidity and mortality, especially in young children. Why RSV infection in children is more severe as compared to healthy adults is not fully understood. In the present study, we infect both pediatric and adult human nose organoid-air liquid interface (HNO-ALIs) cell lines with two contemporary RSV isolates and demonstrate how they differ in virus replication, induction of the epithelial cytokine response, cell injury, and remodeling. Pediatric HNO-ALIs were more susceptible to early RSV replication, elicited a greater overall cytokine response, demonstrated enhanced mucous production, and manifested greater cellular damage compared to their adult counterparts. Adult HNO-ALIs displayed enhanced mucus production and robust cytokine response that was well controlled by superior regulatory cytokine response and possibly resulted in lower cellular damage than in pediatric lines. Taken together, our data suggest substantial differences in how pediatric and adult upper respiratory tract epithelium responds to RSV infection. These differences in epithelial cellular response can lead to poor mucociliary clearance and predispose infants to a worse respiratory outcome of RSV infection.

6.
iScience ; 27(2): 108786, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38322999

RESUMEN

Micro-supercapacitors (MSCs) stand out in the field of micro energy storage devices due to their high power density, long cycle life, and environmental friendliness. The key to improving the electrochemical performance of MSCs is the selection of appropriate electrode materials. To date, both the composition and structure of electrode materials in MSCs have become a hot research topic, and it is urgent to compose a review to highlight the most important research achievements, major challenges, opportunities, and encouraging perspectives in this field. In this review, research background of MSCs is first reviewed followed by their working principles, structural classifications, and physiochemical and electrochemical characterization techniques. Next, various materials and preparation methods are summarized, and the relationship between the MSC performance and structure and composition of materials are discussed in depth. Finally, this review provides a comprehensive suggestion on accelerating the development of electrode materials to facilitate the commercialization of MSCs.

7.
Adv Mater ; 36(16): e2310599, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38300795

RESUMEN

Intractable infected microenvironments caused by drug-resistant bacteria stalls the normal course of wound healing. Sono-piezodynamic therapy (SPT) is harnessed to combat pathogenic bacteria, but the superabundant reactive oxygen species (ROS) generated during SPT inevitably provoke severe inflammatory response, hindering tissue regeneration. Consequently, an intelligent nanocatalytic membrane composed of poly(lactic-co-glycolic acid) (PLGA) and black phosphorus /V2C MXene bio-heterojunctions (2D2-bioHJs) is devised. Under ultrasonication, 2D2-bioHJs effectively eliminate drug-resistant bacteria by disrupting metabolism and electron transport chain (ETC). When ultrasonication ceases, they enable the elimination of SPT-generated ROS. The 2D2-bioHJs act as a "lever" that effectively achieves a balance between ROS generation and annihilation, delivering both antibacterial and anti-inflammatory properties to the engineered membrane. More importantly, in vivo assays corroborate that the nanocatalytic membranes transform the stalled chronic wound environment into a regenerative one by eradicating the bacterial population, dampening the NF-κB inflammatory pathway and promoting angiogenesis. As envisaged, this work demonstrates a novel tactic to arm membranes with programmed antibacterial and anti-inflammatory effects to remedy refractory infected wounds from drug-fast bacteria.


Asunto(s)
Infecciones Bacterianas , Infección de Heridas , Humanos , Especies Reactivas de Oxígeno , Cinética , Antibacterianos , Antiinflamatorios , Hidrogeles
8.
Nanoscale Horiz ; 9(4): 620-626, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38315153

RESUMEN

The alloying of two-dimensional (2D) transition metal dichalcogenides (TMDs) is an established route to produce robust semiconductors with continuously tunable optoelectronic properties. However, typically reported methods for fabricating alloyed 2D TMD nanosheets are not suitable for the inexpensive, scalable production of large-area (m2) devices. Herein we describe a general method to afford large quantities of compositionally-tunable 2D TMD nanosheets using commercially available powders and liquid-phase exfoliation. Beginning with Mo(1-x)WxS2 nanosheets, we demonstrate tunable optoelectronic properties as a function of composition. We extend this method to produce Mo0.5W0.5Se2 MoSSe, WSSe, and quaternary Mo0.5W0.5SSe nanosheets. High-resolution scanning transmission electron microscopy (STEM) imaging confirms the atomic arrangement of the nanosheets, while an array of spectroscopic techniques is used to characterize the chemical and optoelectronic properties. This transversal method represents an important step towards upscaling tailored TMD nanosheets with a broad range of tunable optoelectronic properties for large-area devices.

9.
J Phys Chem Lett ; 15(4): 933-939, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38241729

RESUMEN

Alkaline water electrolysis is a sustainable way to produce green hydrogen using renewable electricity. Even though the rates of the cathodic hydrogen evolution reaction (HER) are 2-3 orders of magnitude less under alkaline conditions than under acidic conditions, the possibility of using non-precious metal catalysts makes alkaline HER appealing. We identify a novel and facile route for substantially improving HER performance via the use of commercially available NiTi shape memory alloys, which upon heating undergo a phase transformation from the monoclinic martensite to the cubic austenite structure. While the room-temperature performance is modest, austenitic NiTi outperforms Pt (which is the state-of-the-art HER electrocatalyst) in terms of current density by ≤50% at 80 °C. Surface ensembles presented by the austenite phase are computed with density functional theory to bind hydrogen more weakly than either metallic Ni or Ti and to have binding energies ideally suited for HER.

10.
Child Abuse Negl ; 149: 106650, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38281406

RESUMEN

BACKGROUND: In cases of child sexual abuse (CSA), a supportive non-offending caregiver (NOC) is important for the child's overall well-being and adjustment. NOC support is also predictive of CSA cases moving forward to prosecution. Limited research has studied CSA case factors in relation to NOC supportive behaviors across numerous support dimensions. OBJECTIVE: We investigated what case details predicted four different dimensions of caregiver support. PARTICIPANTS AND SETTINGS: In this secondary analysis, a sample of 500 CSA cases from four prosecutors' offices in one New England state from 2009 to 2013 were randomly selected and reviewed. METHOD: This study used regression analysis to test 13 case characteristics (e.g., disclosure of abuse, NOC's relationship to perpetrator) as predictors of NOC support dimensions: belief of victim, support of prosecution, protection of victim, and whether a child protective services neglect report was filed against the caregiver. RESULTS: When the perpetrator was their romantic partner, the NOC was less likely to protect and believe the child victim, yet more likely to support prosecution. NOCs were more likely to demonstrate belief when the child disclosed to them first. CONCLUSION: Our findings reveal the importance of the key case factors that are predictive of NOC support. This is the first study to examine these many case factors in relation to these four dimensions of support. Knowledge of these predictors can play an important role in better understanding the complexity of NOC support predictors and facilitating interventions designed to enhance such support.


Asunto(s)
Abuso Sexual Infantil , Maltrato a los Niños , Niño , Humanos , Cuidadores , Revelación , Análisis de Regresión
11.
Cancer Cell Int ; 24(1): 11, 2024 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-38184584

RESUMEN

Protein phosphatase 2A (PP2A) is a serine/threonine phosphatase integral to the regulation of many cellular processes. Due to the deregulation of PP2A in cancer, many of these processes are turned toward promoting tumor progression. Considerable research has been undertaken to discover molecules capable of modulating PP2A activity in cancer. Because PP2A is capable of immense substrate specificity across many cellular processes, the therapeutic targeting of PP2A in cancer can be completed through either enzyme inhibitors or activators. PP2A modulators likewise tend to be effective in drug-resistant cancers and work synergistically with other known cancer therapeutics. In this review, we will discuss the patterns of PP2A deregulation in cancer, and its known downstream signaling pathways important for cancer regulation, along with many activators and inhibitors of PP2A known to inhibit cancer progression.

12.
Adv Mater ; 36(9): e2305277, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37526952

RESUMEN

Nanomaterial-mediated ferroptosis has garnered considerable interest in the antibacterial field, as it invokes the disequilibrium of ion homeostasis and boosts lipid peroxidation in extra- and intracellular bacteria. However, current ferroptosis-associated antibacterial strategies indiscriminately pose damage to healthy cells, ultimately compromising their biocompatibility. To address this daunting issue, this work has designed a precise ferroptosis bio-heterojunction (F-bio-HJ) consisting of Fe2 O3 , Ti3 C2 -MXene, and glucose oxidase (GOx) to induce extra-intracellular bacteria-targeted ferroptosis for infected diabetic cutaneous regeneration. Fe2 O3 /Ti3 C2 -MXene@GOx (FMG) catalytically generates a considerable amount of ROS which assaults the membrane of extracellular bacteria, facilitating the permeation of synchronously generated Fe2+ /Fe3+ into bacteria under near-infrared (NIR) irradiation, causing planktonic bacterial death via ferroptosis, Fe2+ overload, and lipid peroxidation. Additionally, FMG facilitates intracellular bacterial ferroptosis by transporting Fe2+ into intracellular bacteria via inward ferroportin (FPN). With GOx consuming glucose, FMG creates hunger protection which helps macrophages escape cell ferroptosis by activating the adenosine 5'-monophosphate (AMP) activated protein kinase (AMPK) pathway. In vivo results authenticate that FMG boosts diabetic infectious cutaneous regeneration without triggering ferroptosis in normal cells. As envisaged, the proposed tactic provides a promising approach to combat intractable infections by precisely terminating extra-intracellular infection via steerable ferroptosis, thereby markedly elevating the biocompatibility of therapeutic ferroptosis-mediated strategies.


Asunto(s)
Diabetes Mellitus , Ferroptosis , Nitritos , Elementos de Transición , Citoprotección , Hambre , Antibacterianos/farmacología , Glucosa Oxidasa
13.
Small ; 20(4): e2304119, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37759420

RESUMEN

Although antibiotic is still the main choice for antibacteria both in hospital and community, phototherapy has become a possibly one of the alternative approaches in the treatment of microbe-associated infections nowadays because of its considerable potential in effective eradication of pathogenic bacteria. However, overwhelming reactive oxygen species (ROS) generated from phototherapy inevitably provoke an inflammatory response, complicating the healing process. To address this outstanding issue, a MXene-decorated nanofibrious is devised that not only yield localized heat but also elevate ROS levels under near-infrared laser exposure ascribed to the synergistic photothermal/photodynamic effect, for potent bacterial inactivation. After being further loaded with aspirin, the nanofibrous membranes exhibit benign cytocompatibility, boosting cell growth and suppressing the (nuclear factor kappa-B ( NF-κB) signaling pathways through RNA sequencing analysis, indicating an excellent anti-inflammatory effect. Interestingly, in vivo investigations also corroborate that the nanofibrous membranes accelerate infectious cutaneous regeneration by efficiently killing pathogenic bacteria, promoting collagen deposition, boosting angiogenesis, and dampening inflammatory reaction via steering NF-κB pathway. As envisaged, this work furnishes a decorated nanofibrous membrane with programmed antibacterial and anti-inflammatory effects for remedy of refractory bacteria-invaded wound regeneration.


Asunto(s)
FN-kappa B , Nanofibras , Nitritos , Elementos de Transición , FN-kappa B/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Cicatrización de Heridas , Antiinflamatorios/farmacología , Antibacterianos/farmacología
14.
ChemSusChem ; 17(2): e202300969, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-37792861

RESUMEN

Commercialization of photoelectrochemical (PEC) water-splitting devices requires the development of large-area, low-cost photoanodes with high efficiency and photostability. Herein, we address these challenges by using scalable fabrication techniques and porous transport layer (PTLs) electrode supports. We demonstrate the deposition of W-doped BiVO4 on Ti PTLs using successive-ionic-layer-adsorption-and-reaction methods followed by boron treatment and chemical bath deposition of NiFeOOH co-catalyst. The use of PTLs that facilitate efficient mass and charge transfer allowed the scaling of the photoanodes (100 cm2 ) while maintaining ~90 % of the performance obtained with 1 cm2 photoanodes for oxygen evolution reaction, that is, 2.10 mA cm-2 at 1.23 V vs. RHE. This is the highest reported performance to date. Integration with a polycrystalline Si PV cell leads to bias-free water splitting with a stable photocurrent of 208 mA for 6 h and 2.2 % solar-to-hydrogen efficiency. Our findings highlight the importance of photoelectrode design towards scalable PEC device development.

15.
Adv Sci (Weinh) ; 11(3): e2304874, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37939293

RESUMEN

Since the initial discovery of Ti3 C2 a decade ago, there has been a significant surge of interest in 2D MXenes and MXene-based composites. This can be attributed to the remarkable intrinsic properties exhibited by MXenes, including metallic conductivity, abundant functional groups, unique layered microstructure, and the ability to control interlayer spacing. These properties contribute to the exceptional electrical and mechanical performance of MXenes, rendering them highly suitable for implementation as candidate materials in flexible and wearable energy storage devices. Recently, a substantial number of novel research has been dedicated to exploring MXene-based flexible materials with diverse functionalities and specifically designed structures, aiming to enhance the efficiency of energy storage systems. In this review, a comprehensive overview of the synthesis and fabrication strategies employed in the development of these diverse MXene-based materials is provided. Furthermore, an in-depth analysis of the energy storage applications exhibited by these innovative flexible materials, encompassing supercapacitors, Li-ion batteries, Li-S batteries, and other potential avenues, is conducted. In addition to presenting the current state of the field, the challenges encountered in the implementation of MXene-based flexible materials are also highlighted and insights are provided into future research directions and prospects.

16.
Cancer Discov ; 14(2): 274-289, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-37982575

RESUMEN

Fulvestrant is used to treat patients with hormone receptor-positive advanced breast cancer, but acquired resistance is poorly understood. PlasmaMATCH Cohort A (NCT03182634) investigated the activity of fulvestrant in patients with activating ESR1 mutations in circulating tumor DNA (ctDNA). Baseline ESR1 mutations Y537S are associated with poor outcomes and Y537C with good outcomes. Sequencing of baseline and EOT ctDNA samples (n = 69) revealed 3/69 (4%) patients acquired novel ESR1 F404 mutations (F404L, F404I, and F404V), in cis with activating mutations. In silico modeling revealed that ESR1 F404 contributes to fulvestrant binding to estrogen receptor-alpha (ERα) through a pi-stacking bond, with mutations disrupting this bond. In vitro analysis demonstrated that single F404L, E380Q, and D538G models were less sensitive to fulvestrant, whereas compound mutations D538G + F404L and E380Q + F404L were resistant. Several oral ERα degraders were active against compound mutant models. We have identified a resistance mechanism specific to fulvestrant that can be targeted by treatments in clinical development. SIGNIFICANCE: Novel F404 ESR1 mutations may be acquired to cause overt resistance to fulvestrant when combined with preexisting activating ESR1 mutations. Novel combinations of mutations in the ER ligand binding domain may cause drug-specific resistance, emphasizing the potential of similar drug-specific mutations to impact the efficacy of oral ER degraders in development. This article is featured in Selected Articles from This Issue, p. 201.


Asunto(s)
Neoplasias de la Mama , ADN Tumoral Circulante , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Fulvestrant/farmacología , Fulvestrant/uso terapéutico , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , ADN Tumoral Circulante/genética , Mutación
17.
J Interpers Violence ; 39(9-10): 2238-2260, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38158733

RESUMEN

Adults' ability to accurately evaluate children's statements can have far-reaching consequences within the legal system. This study examined the evaluations of police officers ("experts") and laypersons ("nonexperts") when presented with videotaped interviews of children aged 3 and 5 years who provided either true or false reports or denials. Participants were drawn from several counties in the eastern United States. Children's interview statements fell within four statement types: accurate reports, false reports, accurate denials, and false denials. Both groups of participants displayed overbelief in false denials. Several control variables predicted accuracy, including children's age and children's race. A significant interaction emerged: Experts (vs. nonexperts) had greater odds of being accurate when judging false reports (vs. false denials). These findings highlight the challenges adults face when distinguishing between various types of children's statements. The results have important implications for legal contexts, emphasizing that fact finders need to be mindful of the risks associated with both overaccepting false denials and accepting false reports.


Asunto(s)
Memoria , Policia , Niño , Adulto , Humanos , Estados Unidos
18.
ACS Appl Mater Interfaces ; 15(47): 54702-54710, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-37963227

RESUMEN

Efficient management of radionuclides that are released from various processes in the nuclear fuel cycle is of significant importance. Among these nuclides, radioactive iodine (mainly 129I and 131I) is a major concern due to the risk it poses to the environment and to human health; thus, the development of materials that can capture and safely store radioactive iodine is crucial. Herein, a novel silver-thione-functionalized zeolitic imidazole framework (ZIF) was synthesized via postsynthetic modification and assessed for its iodine uptake capabilities alongside the parent ZIF-8 and intermediate materials. A solvent-assisted ligand exchange procedure was used to replace the 2-methylimidazole linkers in ZIF-8 with 2-mercaptoimidazole, forming intermediate compound ZIF-8 = S, which was reacted with AgNO3 to yield the ZIF-8 = S-Ag+ composite for iodine uptake. Despite possessing the lowest BET surface area of the derivatives, the Ag-functionalized material demonstrated superior I2 adsorption in terms of both maximum capacity (550 g I2/mol) and rapid kinetics (50% loading achieved in 5 h, saturation in 50 h) compared to that of our pristine ZIF-8, which reached 450 g I2/mol after 150 h and 50% loading in 25 h. This improvement is attributed to the presence of the Ag+ ions, which provide a strong chemical driving force to form a stable Ag-I species. The results of this study contribute to a broader understanding of the strategies that can be employed to engineer adsorbents with robust iodine uptake behavior.

19.
Steroids ; 200: 109313, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37758052

RESUMEN

In this short review we discuss the current view of how the estrogen receptor (ER), a pivotal member of the nuclear receptor superfamily of transcription factors, regulates gene transcription at the single cell and allele level, focusing on in vitro cell line models. We discuss central topics and new trends in molecular biology including phenotypic heterogeneity, single cell sequencing, nuclear phase separated condensates, single cell imaging, and image analysis methods, with particular focus on the methodologies and results that have been reported in the last few years using microscopy-based techniques. These observations augment the results from biochemical assays that lead to a much more complex and dynamic view of how ER, and arguably most transcription factors, act to regulate gene transcription.


Asunto(s)
Regulación de la Expresión Génica , Receptores de Estrógenos , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Alelos , Factores de Transcripción/metabolismo , Transcripción Genética , Receptor alfa de Estrógeno/metabolismo
20.
bioRxiv ; 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37693572

RESUMEN

Single molecule fluorescence in situ hybridization (smFISH) can be used to visualize transcriptional activation at the single allele level. We and others have applied this approach to better understand the mechanisms of activation by steroid nuclear receptors. However, there is limited understanding of the interconnection between the activation of target gene alleles inside the same nucleus and within large cell populations. Using the GREB1 gene as an early estrogen receptor (ER) response target, we applied smFISH to track E2-activated GREB1 allelic transcription over early time points to evaluate potential dependencies between alleles within the same nucleus. We compared two types of experiments where we altered the initial status of GREB1 basal transcription by treating cells with and without the elongation inhibitor flavopiridol (FV). E2 stimulation changed the frequencies of active GREB1 alleles in the cell population independently of FV pre-treatment. In FV treated cells, the response time to hormone was delayed, albeit still reaching at 90 minutes the same levels as in cells not treated by FV. We show that the joint frequencies of GREB1 activated alleles observed at the cell population level imply significant dependency between pairs of alleles within the same nucleus. We identify probabilistic models of joint alleles activations by applying a principle of maximum entropy. For pairs of alleles, we have then quantified statistical dependency by computing their mutual information. We have then introduced a stochastic model compatible with allelic statistical dependencies, and we have fitted this model to our data by intensive simulations. This provided estimates of the average lifetime for degradation of GREB1 introns and of the mean time between two successive transcription rounds. Our approach informs on how to extract information on single allele regulation by ER from within a large population of cells, and should be applicable to many other genes. AUTHOR SUMMARY: After application of a gene transcription stimulus, in this case the hormone 17 ß -estradiol, on large populations of cells over a short time period, we focused on quantifying and modeling the frequencies of GREB1 single allele activations. We have established an experimental and computational pipeline to analyze large numbers of high resolution smFISH images to detect and monitor active GREB1 alleles, that can be translatable to any target gene of interest. A key result is that, at the population level, activation of individual GREB1 alleles within the same nucleus do exhibit statistically significant dependencies which we quantify by the mutual information between activation states of pairs of alleles. After noticing that frequencies of joint alleles activations observed over our large cell populations evolve smoothly in time, we have defined a population level stochastic model which we fit to the observed time course of GREB1 activation frequencies. This provided coherent estimates of the mean time between rounds of GREB1 transcription and the mean lifetime of nascent mRNAs. Our algorithmic approach and experimental methods are applicable to many other genes.

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