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1.
J Exp Biol ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38511428

RESUMO

Odorants interact with receptors expressed in specialized olfactory neurons, and neurons of the same class send their axons to distinct glomeruli in the brain. The stereotypic spatial glomerular activity map generates recognition and behavioral response for the odorant. The valence of an odorant changes with concentration, typically becoming aversive at higher concentrations. Interestingly in the Drosophila larvae, the odorant (E)-2-hexenal is aversive at low concentrations and attractive at higher concentrations. We investigate the molecular and neural basis of this phenomenon focusing on how activities of different olfactory neurons conveying opposing effects dictate behaviors. We identify the repellant neuron in the larvae as one expressing the olfactory receptor Or7a, whose activation alone at low concentrations of (E)-2-hexenal elicits an avoidance response in an Or7a dependent manner. We demonstrate that avoidance can be overcome at higher concentrations by activation of additional neurons that are known to be attractive, most notably known activators of Or42a and Or85c. These findings suggest that in the larval stage, the attraction-conveying neurons can overcome the aversion-conveying channels for (E)-2-hexenal.

2.
Ecology ; 105(4): e4274, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38419360

RESUMO

Identification of the key biotic and abiotic drivers within food webs is important for understanding species abundance changes in ecosystems, particularly across ecotones where there may be strong variation in interaction strengths. Using structural equation models (SEMs) and four decades of integrated data from the San Francisco Estuary, we investigated the relative effects of top-down, bottom-up, and environmental drivers on multiple trophic levels of the pelagic food web along an estuarine salinity gradient and at both annual and monthly temporal resolutions. We found that interactions varied across the estuarine gradient and that the detectability of different interactions depended on timescale. For example, for zooplankton and estuarine fishes, bottom-up effects appeared to be stronger in the freshwater upstream regions, while top-down effects were stronger in the brackish downstream regions. Some relationships (e.g., bottom-up effects of phytoplankton on zooplankton) were seen primarily at annual timescales, whereas others (e.g., temperature effects) were only observed at monthly timescales. We also found that the net effect of environmental drivers was similar to or greater than bottom-up and top-down effects for all food web components. These findings can help identify which trophic levels or environmental factors could be targeted by management actions to have the greatest impact on estuarine forage fishes and the spatial and temporal scale at which responses might be observed. More broadly, this study highlights how environmental gradients can structure community interactions and how long-term data sets can be leveraged to generate insights across multiple scales.


Assuntos
Ecossistema , Cadeia Alimentar , Animais , Água Doce , Peixes/fisiologia , Fitoplâncton/fisiologia , Zooplâncton/fisiologia
3.
Elife ; 122024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38411140

RESUMO

Eukaryotes respond to secreted metabolites from the microbiome. However, little is known about the effects of exposure to volatiles emitted by microbes or in the environment that we are exposed to over longer durations. Using Drosophila melanogaster, we evaluated a yeast-emitted volatile, diacetyl, found at high levels around fermenting fruits where they spend long periods of time. Exposure to the diacetyl molecules in headspace alters gene expression in the antenna. In vitro experiments demonstrated that diacetyl and structurally related volatiles inhibited conserved histone deacetylases (HDACs), increased histone-H3K9 acetylation in human cells, and caused changes in gene expression in both Drosophila and mice. Diacetyl crosses the blood-brain barrier and exposure caused modulation of gene expression in the mouse brain, therefore showing potential as a neuro-therapeutic. Using two separate disease models previously known to be responsive to HDAC inhibitors, we evaluated the physiological effects of volatile exposure. Diacetyl exposure halted proliferation of a neuroblastoma cell line in culture. Exposure to diacetyl vapors slowed progression of neurodegeneration in a Drosophila model for Huntington's disease. These changes strongly suggest that certain volatiles in the surroundings can have profound effects on histone acetylation, gene expression, and physiology in animals.


Assuntos
Drosophila melanogaster , Histona Desacetilases , Humanos , Camundongos , Animais , Histona Desacetilases/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Histonas/metabolismo , Odorantes , Diacetil , Inibidores de Histona Desacetilases/farmacologia , Drosophila/genética , Sistema Nervoso/metabolismo , Expressão Gênica , Acetilação
4.
J Gen Intern Med ; 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38332440

RESUMO

BACKGROUND: Bundling is combining individual interventions to meet quality metrics. Bundling offers of cancer screening with screening for social determinants of health (SDOH) may enable health centers to assist patients with social risks and yield efficiencies. OBJECTIVE: To measure effects of bundling fecal immunochemical testing (FIT) and SDOH screening in federally qualified health centers (FQHCs). DESIGN: Clustered stepped-wedge trial. PARTICIPANTS: Four Massachusetts FQHCs randomized to implement bundled FIT-SDOH over 8-week "steps." INTERVENTION: Outreach to 50-75-year-olds overdue for CRC screening to offer FIT with SDOH screening. The implementation strategy used facilitation and training for data monitoring and reporting. MAIN MEASURES: Implementation process descriptions, data from facilitation meetings, and CRC and SDOH screening rates. Rates were compared between implementation and control FQHCs in each "step" by fitting generalized linear mixed-effects models with random intercepts for FQHCs, patients, and "step" by FQHC. KEY RESULTS: FQHCs tailored implementation processes to their infrastructure, workflows, and staffing and prioritized different groups for outreach. Two FQHCs used population health outreach, and two integrated FIT-SDOH within established programs, such as pre-visit planning. Of 34,588 patients overdue for CRC screening, 54% were female; 20% Black, 11% Latino, 10% Asian, and 47% white; 32% had Medicaid, 16% Medicare, 32% private insurance, and 11% uninsured. Odds of CRC screening completion in implementation "steps" compared to controls were higher overall and among groups prioritized for outreach (overall: adjusted odds ratio (aOR) 2.41, p = 0.005; prioritized: aOR 2.88, p = 0.002). Odds of SDOH screening did not differ across "steps." CONCLUSIONS: As healthcare systems are required to conduct more screenings, it is notable that outreach for a long-standing cancer screening requirement increased screening, even when bundled with a newer screening requirement. This outreach was feasible in a real-world safety-net clinical population and may conserve resources, especially compared to more complex or intensive outreach strategies. CLINICAL TRIALS REGISTRATION: NCT04585919.

5.
Acad Radiol ; 31(4): 1643-1654, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38177034

RESUMO

RATIONALE AND OBJECTIVES: The absence of published reference values for multilayer-specific strain measurement using cardiac magnetic resonance (CMR) in young healthy individuals limits its use. This study aimed to establish normal global and layer-specific strain values in healthy children and young adults using a deformable registration algorithm (DRA). MATERIALS AND METHODS: A retrospective study included 131 healthy children and young adults (62 males and 69 females) with a mean age of 16.6 ± 3.9 years. CMR examinations were conducted using 1.5T scanners, and strain analysis was performed using TrufiStrain research prototype software (Siemens Healthineers, Erlangen, Germany). Global and layer-specific strain parameters were extracted from balanced Steady-state free precession cine images. Statistical analyses were conducted to evaluate the impact of demographic variables on strain measurements. RESULTS: The peak global longitudinal strain (LS) was -16.0 ± 3.0%, peak global radial strain (RS) was 29.9 ± 6.3%, and peak global circumferential strain (CS) was -17.0 ± 1.8%. Global LS differed significantly between males and females. Transmural strain analysis showed a consistent pattern of decreasing LS and CS from endocardium to epicardium, while radial strain increased. Basal-to-apical strain distribution exhibited decreasing LS and increasing CS in both global and layer-specific analysis. CONCLUSION: This study uses DRA to provide reference values for global and layer-specific strain in healthy children and young adults. The study highlights the impact of sex and age on LS and body mass index on RS. These insights are vital for future cardiac assessments in children, particularly for early detection of heart diseases.


Assuntos
Inteligência Artificial , Imagem Cinética por Ressonância Magnética , Masculino , Feminino , Criança , Humanos , Adulto Jovem , Adolescente , Adulto , Imagem Cinética por Ressonância Magnética/métodos , Estudos Retrospectivos , Ventrículos do Coração , Imageamento por Ressonância Magnética/métodos , Função Ventricular Esquerda
6.
Acc Chem Res ; 57(3): 386-398, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38252962

RESUMO

ConspectusIntracellular compartmentalization plays a pivotal role in cellular function, with membrane-bound organelles and membrane-less biomolecular "condensates" playing key roles. These condensates, formed through liquid-liquid phase separation (LLPS), enable selective compartmentalization without the barrier of a lipid bilayer, thereby facilitating rapid formation and dissolution in response to stimuli. Intrinsically disordered proteins (IDPs) or proteins with intrinsically disordered regions (IDRs), which are often rich in charged and polar amino acid sequences, scaffold many condensates, often in conjunction with RNA.Comprehending the impact of IDP/IDR sequences on phase separation poses a challenge due to the extensive chemical diversity resulting from the myriad amino acids and post-translational modifications. To tackle this hurdle, one approach has been to investigate LLPS in simplified polypeptide systems, which offer a narrower scope within the chemical space for exploration. This strategy is supported by studies that have demonstrated how IDP function can largely be understood based on general chemical features, such as clusters or patterns of charged amino acids, rather than residue-level effects, and the ways in which these kinds of motifs give rise to an ensemble of conformations.Our laboratory has utilized complex coacervates assembled from oppositely charged polypeptides as a simplified material analogue to the complexity of liquid-liquid phase separated biological condensates. Complex coacervation is an associative LLPS that occurs due to the electrostatic complexation of oppositely charged macro-ions. This process is believed to be driven by the entropic gains resulting from the release of bound counterions and the reorganization of water upon complex formation. Apart from their direct applicability to IDPs, polypeptides also serve as excellent model polymers for investigating molecular interactions due to the wide range of available side-chain functionalities and the capacity to finely regulate their sequence, thus enabling precise control over interactions with guest molecules.Here, we discuss fundamental studies examining how charge patterning, hydrophobicity, chirality, and architecture affect the phase separation of polypeptide-based complex coacervates. These efforts have leveraged a combination of experimental and computational approaches that provide insight into molecular level interactions. We also examine how these parameters affect the ability of complex coacervates to incorporate globular proteins and viruses. These efforts couple directly with our fundamental studies into coacervate formation, as such "guest" molecules should not be considered as experiencing simple encapsulation and are instead active participants in the electrostatic assembly of coacervate materials. Interestingly, we observed trends in the incorporation of proteins and viruses into coacervates formed using different chain length polypeptides that are not well explained by simple electrostatic arguments and may be the result of more complex interactions between globular and polymeric species. Additionally, we describe experimental evidence supporting the potential for complex coacervates to improve the thermal stability of embedded biomolecules, such as viral vaccines.Ultimately, peptide-based coacervates have the potential to help unravel the physics behind biological condensates, while paving the way for innovative methods in compartmentalization, purification, and biomolecule stabilization. These advancements could have implications spanning medicine to biocatalysis.


Assuntos
Proteínas Intrinsicamente Desordenadas , Peptídeos , Humanos , Peptídeos/química , Sequência de Aminoácidos , Organelas/química , RNA/análise , Polímeros/química , Aminoácidos/análise , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/genética , Proteínas Intrinsicamente Desordenadas/metabolismo
7.
Am J Speech Lang Pathol ; 33(2): 1069-1097, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38232176

RESUMO

PURPOSE: This systematic review represents an update to previous reviews of the literature addressing behavioral management of respiratory/phonatory dysfunction in individuals with dysarthria due to neurodegenerative disease. METHOD: Multiple electronic database searches and hand searches of prominent speech-language pathology journals were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards. RESULTS: The search yielded 1,525 articles, from which 88 met inclusion criteria and were reviewed by two blinded co-investigators. A large range of therapeutic approaches have been added to the evidence base since the last review, including expiratory muscle strength training, singing, and computer- and device-driven programs, as well as a variety of treatment modalities, including teletherapy. Evidence for treatment in several different population groups-including cerebellar ataxia, myotonic dystrophy, autosomal recessive spastic ataxia of Charlevoix-Saguenay, Huntington's disease, multiple system atrophy, and Lewy body dementia-were added to the current review. Synthesis of evidence quality provided strong evidence in support of only one behavioral intervention: Lee Silverman Voice Treatment Program (LSVT LOUD) in people with Parkinson's disease. No other treatment approach or population included in this review demonstrated more than limited evidence, reflecting that these approaches/populations require urgent further examination. CONCLUSION: Suggestions about where future research efforts could be significantly strengthened and how clinicians can apply research findings to their practice are provided. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24964473.


Assuntos
Doenças Neurodegenerativas , Doença de Parkinson , Humanos , Doenças Neurodegenerativas/complicações , Doenças Neurodegenerativas/terapia , Disartria/diagnóstico , Disartria/etiologia , Disartria/terapia , Fonoterapia , Treinamento da Voz , Doença de Parkinson/complicações
8.
Acad Radiol ; 31(2): 503-513, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37541826

RESUMO

RATIONALE AND OBJECTIVES: Cardiac magnetic resonance imaging is crucial for diagnosing cardiovascular diseases, but lengthy postprocessing and manual segmentation can lead to observer bias. Deep learning (DL) has been proposed for automated cardiac segmentation; however, its effectiveness is limited by the slice range selection from base to apex. MATERIALS AND METHODS: In this study, we integrated an automated slice range classification step to identify basal to apical short-axis slices before DL-based segmentation. We employed publicly available Multi-Disease, Multi-View & Multi-Center Right Ventricular Segmentation in Cardiac MRI data set with short-axis cine data from 160 training, 40 validation, and 160 testing cases. Three classification and seven segmentation DL models were studied. The top-performing segmentation model was assessed with and without the classification model. Model validation to compare automated and manual segmentation was performed using Dice score and Hausdorff distance and clinical indices (correlation score and Bland-Altman plots). RESULTS: The combined classification (CBAM-integrated 2D-CNN) and segmentation model (2D-UNet with dilated convolution block) demonstrated superior performance, achieving Dice scores of 0.952 for left ventricle (LV), 0.933 for right ventricle (RV), and 0.875 for myocardium, compared to the stand-alone segmentation model (0.949 for LV, 0.925 for RV, and 0.867 for myocardium). Combined classification and segmentation model showed high correlation (0.92-0.99) with manual segmentation for biventricular volumes, ejection fraction, and myocardial mass. The mean absolute difference (2.8-8.3 mL) for clinical parameters between automated and manual segmentation was within the interobserver variability range, indicating comparable performance to manual annotation. CONCLUSION: Integrating an initial automated slice range classification step into the segmentation process improves the performance of DL-based cardiac chamber segmentation.


Assuntos
Aprendizado Profundo , Humanos , Imageamento por Ressonância Magnética , Coração/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Miocárdio/patologia , Imagem Cinética por Ressonância Magnética/métodos
9.
Biomacromolecules ; 25(2): 741-753, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38103178

RESUMO

Encapsulation is a strategy that has been used to facilitate the delivery and increase the stability of proteins and viruses. Here, we investigate the encapsulation of viruses via complex coacervation, which is a liquid-liquid phase separation resulting from the complexation of oppositely charged polymers. In particular, we utilized polypeptide-based coacervates and explored the effects of peptide chemistry, chain length, charge patterning, and hydrophobicity to better understand the effects of the coacervating polypeptides on virus incorporation. Our study utilized two nonenveloped viruses, porcine parvovirus (PPV) and human rhinovirus (HRV). PPV has a higher charge density than HRV, and they both appear to be relatively hydrophobic. These viruses were compared to characterize how the charge, hydrophobicity, and patterning of chemistry on the surface of the virus capsid affects encapsulation. Consistent with the electrostatic nature of complex coacervation, our results suggest that electrostatic effects associated with the net charge of both the virus and polypeptide dominated the potential for incorporating the virus into a coacervate, with clustering of charges also playing a significant role. Additionally, the hydrophobicity of a virus appears to determine the degree to which increasing the hydrophobicity of the coacervating peptides can enhance virus uptake. Nonintuitive trends in uptake were observed with regard to both charge patterning and polypeptide chain length, with these parameters having a significant effect on the range of coacervate compositions over which virus incorporation was observed. These results provide insights into biophysical mechanisms, where sequence effects can control the uptake of proteins or viruses into biological condensates and provide insights for use in formulation strategies.


Assuntos
Peptídeos , Vírus , Humanos , Peptídeos/química , Proteínas/química , Polímeros/química , Vírion
10.
Telemed J E Health ; 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38039352

RESUMO

Background: In December 2021, the Region 1 Disaster Health Response System, the state of Vermont, and the National Emergency Tele-Critical Care Network partnered to provide statewide access to disaster teleconsultations during COVID-19 surge conditions. In this case report, we describe how a disaster teleconsultation system was implemented in Vermont to provide access to temporary tele-critical care consultations during the Omicron COVID-19 surge. Methods: We measured the time from request of service to implementation and calculated descriptive statistics. Results: Seven of Vermont's 14 hospitals requested the service. Despite a technology solution capable of providing services within hours, mean time to service implementation was 27 days (interquartile range 20-41 days). Conclusions: Integration of disaster teleconsultation systems into state and local emergency management plans are needed to bring administrative start-up times in line with technical readiness.

11.
Cerebellum ; 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38032397

RESUMO

Cerebellar ataxias are neurological conditions with a high prevalence of aspiration pneumonia and dysphagia. Recent research shows that sensorimotor cough dysfunction is associated with airway invasion and dysphagia in other neurological conditions and may increase the risk of pneumonia. Therefore, this study aimed to characterize sensorimotor cough function and its relationship with ataxia severity. Thirty-seven participants with cerebellar ataxia completed voluntary and/or reflex cough testing. Ataxia severity was assessed using the Scale for the Assessment and Rating of Ataxia (SARA). Linear multilevel models revealed voluntary cough peak expiratory flow rate (PEFR) estimates of 2.61 L/s and cough expired volume (CEV) estimates of 0.52 L. Reflex PEFR (1.82 L/s) and CEV (0.34 L) estimates were lower than voluntary PEFR and CEV estimates. Variability was higher for reflex PEFR (15.74% coefficient of variation [CoV]) than voluntary PEFR (12.13% CoV). 46% of participants generated at least two, two-cough responses following presentations of reflex cough stimuli. There was a small inverse relationship between ataxia severity and voluntary PEFR (ß = -0.05, 95% CI: -0.09 - -0.01 L) and ataxia severity and voluntary CEV (ß = -0.01, 95% CI: -0.02 - -0.004 L/s). Relationships between reflex cough motor outcomes (PEFR ß = 0.03, 95% CI: -0.007-0.07 L/s; CEV ß = 0.007, 95% CI: -0.004-0.02 L) and ataxia severity were not statistically robust. Results indicate that voluntary and reflex cough sensorimotor dysfunction is present in cerebellar ataxias and that increased severity of ataxia symptoms may impact voluntary cough function.

12.
bioRxiv ; 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37808853

RESUMO

Tissue-specific gene knockout by CRISPR/Cas9 is a powerful approach for characterizing gene functions in animal development. However, this approach has been successfully applied in only a small number of Drosophila tissues. The Drosophila motor nervous system is an excellent model system for studying the biology of neuromuscular junction (NMJ). To expand tissue-specific CRISPR to the Drosophila motor system, here we present a CRISPR-mediated tissue-restricted mutagenesis (CRISPR-TRiM) toolkit for knocking out genes in motoneurons, muscles, and glial cells. We validated the efficacy of this toolkit by knocking out known genes in each tissue, demonstrated its orthogonal use with the Gal4/UAS binary expression system, and showed simultaneous knockout of multiple redundant genes. Using these tools, we discovered an essential role for SNARE pathways in NMJ maintenance. Furthermore, we demonstrate that the canonical ESCRT pathway suppresses NMJ bouton growth by downregulating the retrograde Gbb signaling. Lastly, we found that axon termini of motoneurons rely on ESCRT-mediated intra-axonal membrane trafficking to lease extracellular vesicles at the NMJ.

13.
J Am Coll Radiol ; 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37777077

RESUMO

OBJECTIVES: Few level I trauma, tertiary care, academic centers have a paid, permanent reading room coordinator (RRC) to facilitate image management services during off-hour calls, to minimize interruptions to reading workflow. The purpose of this study is to investigate the effect of an RRC on the efficiency of radiology residents signing preliminary reports for emergency department (ED) and inpatient studies. METHODS: A pre- and postintervention retrospective review was performed, using carestream PACS to retrieve imaging studies read on call during two time periods-July 1 to December 1, 2019 (pre-RRC), and July 1 to December 1, 2021 (post-RRC). Efficiency of residents signing preliminary reports was measured by turnaround time (TAT), defined as the time from when a study was marked complete by a technologist to when a preliminary report was signed by a resident, in PACS. RESULTS: In the above time periods, residents interpreted a total of 64,406 studies on call. For ED studies, the mean TAT was 7.0 min shorter post-RRC, compared with pre-RRC (95% confidence interval [CI]: -7.8 to -6.1, (t = 15.50, degrees of freedom (df) = 31,866, P < .0001). The percentage of ED studies signed within 30 min increased from 57.7% to 65.8%, an increase of 8.1% (95% CI: 7.0% to 9.1%) after employing an RRC (χ2 = 228.11, df = 1, P < .0001). For inpatient studies, the mean TAT was 10.2 min shorter post-RRC (95% CI: -12.3 to -8.0, t = 9.22, df = 25,193, P < .0001). CONCLUSIONS: An RRC increased radiology resident on-call workflow efficiency, facilitating care for patients in both the ED and inpatient setting.

14.
Nat Commun ; 14(1): 4119, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37433773

RESUMO

The accumulation of atypical, cytotoxic 1-deoxysphingolipids (1-dSLs) has been linked to retinal diseases such as diabetic retinopathy and Macular Telangiectasia Type 2. However, the molecular mechanisms by which 1-dSLs induce toxicity in retinal cells remain poorly understood. Here, we integrate bulk and single-nucleus RNA-sequencing to define biological pathways that modulate 1-dSL toxicity in human retinal organoids. Our results demonstrate that 1-dSLs differentially activate signaling arms of the unfolded protein response (UPR) in photoreceptor cells and Müller glia. Using a combination of pharmacologic activators and inhibitors, we show that sustained PERK signaling through the integrated stress response (ISR) and deficiencies in signaling through the protective ATF6 arm of the UPR are implicated in 1-dSL-induced photoreceptor toxicity. Further, we demonstrate that pharmacologic activation of ATF6 mitigates 1-dSL toxicity without impacting PERK/ISR signaling. Collectively, our results identify new opportunities to intervene in 1-dSL linked diseases through targeting different arms of the UPR.


Assuntos
Retinopatia Diabética , Telangiectasia Retiniana , Humanos , Esfingolipídeos , Resposta a Proteínas não Dobradas
15.
Cell Rep ; 42(7): 112775, 2023 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-37436892

RESUMO

Ionotropic glutamate receptors (GluRs) are targets for modulation in Hebbian and homeostatic synaptic plasticity and are remodeled by development, experience, and disease. We have probed the impact of synaptic glutamate levels on the two postsynaptic GluR subtypes at the Drosophila neuromuscular junction, GluRA and GluRB. We first demonstrate that GluRA and GluRB compete to establish postsynaptic receptive fields, and that proper GluR abundance and composition can be orchestrated in the absence of any synaptic glutamate release. However, excess glutamate adaptively tunes postsynaptic GluR abundance, echoing GluR scaling observed in mammalian systems. Furthermore, when GluRA vs. GluRB competition is eliminated, GluRB becomes insensitive to glutamate modulation. In contrast, GluRA is now homeostatically regulated by excess glutamate to maintain stable miniature activity, where Ca2+ permeability through GluRA receptors is required. Thus, excess glutamate, GluR competition, and Ca2+ signaling collaborate to selectively target GluR subtypes for homeostatic regulation at postsynaptic compartments.


Assuntos
Proteínas de Drosophila , Sinapses , Animais , Sinapses/fisiologia , Ácido Glutâmico , Junção Neuromuscular/fisiologia , Drosophila , Plasticidade Neuronal/fisiologia , Mamíferos
16.
Glia ; 71(10): 2372-2382, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37335016

RESUMO

In the retina, microglia are resident immune cells that are essential for development and function. Retinal microglia play a central role in mediating pathological degeneration in diseases such as glaucoma, retinitis pigmentosa, age-related neurodegeneration, ischemic retinopathy, and diabetic retinopathy. Current models of mature human retinal organoids (ROs) derived from iPS cell (hiPSC) do not contain resident microglia integrated into retinal layers. Increasing cellular diversity in ROs by including resident microglia would more accurately represent the native retina and better model diseases in which microglia play a key role. In this study, we develop a new 3D in vitro tissue model of microglia-containing retinal organoids by co-culturing ROs and hiPSC-derived macrophage precursor cells (MPCs). We optimized the parameters for successful integration of MPCs into retinal organoids. We show that while in the ROs, MPCs migrate to the equivalent of the outer plexiform layer where retinal microglia cells reside in healthy retinal tissue. While there, they develop a mature morphology characterized by small cell bodies and long branching processes which is only observed in vivo. During this maturation process these MPCs cycle through an activated phase followed by a stable mature microglial phase as seen by the down regulation of pro-inflammatory cytokines and upregulation of anti-inflammatory cytokines. Finally, we characterized mature ROs with integrated MPCs using RNAseq showing an enrichment of cell-type specific microglia markers. We propose that this co-culture system may be useful for understanding the pathogenesis of retinal diseases involving retinal microglia and for drug discovery directly in human tissue.


Assuntos
Células-Tronco Pluripotentes Induzidas , Doenças Retinianas , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Microglia/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Retina , Doenças Retinianas/patologia , Organoides/patologia , Macrófagos/patologia , Citocinas/metabolismo
17.
Trends Biochem Sci ; 48(9): 746-747, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37344325

RESUMO

Recently a report by Ruan et al. in Nature described how relatively simple random heteropolymers can replicate the properties of biological fluids. These polymers capture the segmental-level interactions between proteins and could enhance folding of membrane proteins, improve stability, and enable DNA sequestration in a chemistry specific manner.


Assuntos
Polímeros , Proteínas , Polímeros/química , Proteínas/química , DNA
19.
J Assist Reprod Genet ; 40(6): 1349-1359, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37133690

RESUMO

PURPOSE: There has been a noted parallel rise in both the use of Assisted Reproductive Technology (ART) to conceive and childhood allergies in the last few decades. The purpose of this study was to investigate the possible association between reproductive and allergy history in parents and allergies in their children. METHODS: This exploratory study used a cross-sectional study design and web-based survey to collect anonymous data on demographics, allergy, and health history from parents and about each of their children under 18 years of age. Children were stratified into two groups by allergy status (yes/no), and associations between each variable and the odds of allergies were tested using univariable and multivariable mixed logistic regression models. RESULTS: Of the 563 children in the study, 237 were reported to have allergies whereas 326 did not. Age, residential community, household income, mode of conception, paternal age at conception, biological parental allergy status, and history of asthma and eczema were significantly associated with allergies in univariable analysis. Multivariable analysis revealed household income ($50 k to $99 k vs ≥ $200 k adj OR = 2.72, 95% CI 1.11, 6.65), biological parental allergies (mother-adj OR 2.74, 95% CI 1.59, 4.72, father-adj OR 2.06, 95% CI 1.24, 3.41) and each additional year of age of children (adj OR 1.17, CI 1.10, 1.24) were significantly associated with odds of allergies in children. CONCLUSION: Although the exploratory nature of this convenience, snowballing sample limited the generalizability of the findings, initial observations warrant further investigation and validation in a larger more diverse population.


Assuntos
Asma , Eczema , Hipersensibilidade , Criança , Feminino , Humanos , Adolescente , Estudos Transversais , Hipersensibilidade/epidemiologia , Asma/epidemiologia , Eczema/epidemiologia , Pais
20.
J Neurosci ; 43(25): 4598-4611, 2023 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-37221096

RESUMO

Neurons exhibit a striking degree of functional diversity, each one tuned to the needs of the circuitry in which it is embedded. A fundamental functional dichotomy occurs in activity patterns, with some neurons firing at a relatively constant "tonic" rate, while others fire in bursts, a "phasic" pattern. Synapses formed by tonic versus phasic neurons are also functionally differentiated, yet the bases of their distinctive properties remain enigmatic. A major challenge toward illuminating the synaptic differences between tonic and phasic neurons is the difficulty in isolating their physiological properties. At the Drosophila neuromuscular junction, most muscle fibers are coinnervated by two motor neurons: the tonic "MN-Ib" and phasic "MN-Is." Here, we used selective expression of a newly developed botulinum neurotoxin transgene to silence tonic or phasic motor neurons in Drosophila larvae of either sex. This approach highlighted major differences in their neurotransmitter release properties, including probability, short-term plasticity, and vesicle pools. Furthermore, Ca2+ imaging demonstrated ∼2-fold greater Ca2+ influx at phasic neuron release sites relative to tonic, along with an enhanced synaptic vesicle coupling. Finally, confocal and super-resolution imaging revealed that phasic neuron release sites are organized in a more compact arrangement, with enhanced stoichiometry of voltage-gated Ca2+ channels relative to other active zone scaffolds. These data suggest that distinctions in active zone nano-architecture and Ca2+ influx collaborate to differentially tune glutamate release at tonic versus phasic synaptic subtypes.SIGNIFICANCE STATEMENT "Tonic" and "phasic" neuronal subtypes, based on differential firing properties, are common across many nervous systems. Using a recently developed approach to selectively silence transmission from one of these two neurons, we reveal specialized synaptic functional and structural properties that distinguish these specialized neurons. This study provides important insights into how input-specific synaptic diversity is achieved, which could have implications for neurologic disorders that involve changes in synaptic function.


Assuntos
Junção Neuromuscular , Sinapses , Animais , Sinapses/fisiologia , Junção Neuromuscular/metabolismo , Vesículas Sinápticas/metabolismo , Neurônios Motores/fisiologia , Drosophila
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