bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiac sympathetic denervation prevents sudden cardiac arrest and improves cardiac function by enhancing mitochondrial-antioxidant capacity
Authors: Dey Swati , Joshi Pooja , O’Rourke Brian , Estes Shanea , DeMazumder Deeptankar 
Published: February 2023

ABSTRACTRATIONALESudden cardiac arrest (SCA) and heart failure (HF) are leading causes of death. The underlying mechanisms are incompletely understood, limiting the design of new therapies. Whereas most autonomic modulation therapies have not shown clear benefit in HF patients, growing evidence indicates cardiac sympathetic denervation (CSD) exerts cardioprotective effects. The underlying molecular and cellular mechanisms remain unexplored.OBJECTIVEBased on the hypothesis that mitochondrial reactive oxygen species (mROS) drive the pathogenesis of HF and SCA, we investigated whether CSD prevents SCA and HF by improving mitochondrial antioxidant capacity and redox balance, to correct impaired Ca2+handling and repolarization reserve.METHODS AND RESULTSWe interrogated CSD-specific responses in pressure-overload HF models with spontaneous SCA usingin vivoechocardiographic and electrocardiographic studies andin vitrobiochemical and functional studies including ratiometric measures of mROS, Ca2+and sarcomere dynamics in left ventricular myocytes. Pressure-overloaded HF reduced mitochondrial antioxidant capacity and increased mROS, which impaired β-adrenergic signaling and caused SR Ca2+leak, reducing SR Ca2+and increasing diastolic Ca2+, impaired myofilament contraction and further increased the sympathetic stress response. CSD improved contractile function and mitigated mROS-mediated diastolic Ca2+overload, dispersion of repolarization, triggered activity and SCA by upregulating mitochondrial antioxidant and NADPH-producing enzymes.CONCLUSIONSOur findings support a fundamental role of sympathetic stress-induced downregulation of mROS scavenging enzymes and RyR-leak mediated diastolic Ca2+overload in HF and SCA pathogenesis that are mitigated by CSD. This first report on the molecular and cellular mechanisms of CSD supports its evaluation in additional high-risk patient groups.BRIEF SUMMARYCardiac sympathetic denervation (CSD) confers cardioprotective effects via unclear mechanisms. In a guinea pig model that uniquely mimics human pressure-overload heart failure (HF) with spontaneous sudden cardiac arrest (SCA), we interrogated CSD-specific responses using echocardiographic, electrocardiographic and biochemical measures, and ratiometric measures of mitochondrial reactive oxygen species (mROS), Ca2+and sarcomere dynamics. Consistent with our hypothesis, CSD rescued cardioprotection by upregulating mitochondrial antioxidant and NADPH-producing enzymes, which mitigate mROS-mediated Ca2+derangements, repolarization lability, triggered activity, HF and SCA. Our findings provide the first molecular and cellular mechanistic basis for evaluating CSD therapy in a broader group of high-risk patients.
PlasmodiumARK2-EB1 axis drives the unconventional spindle dynamics, scaffold formation and chromosome segregation of sexual transmission stages
Authors: Zeeshan Mohammad , Rea Edward , Abel Steven , Vukušić Kruno , Markus Robert , Brady Declan , Eze Antonius , Raspa Ravish , Balestra Aurelia , Bottrill Andrew R. , Brochet Mathieu , Guttery David S. , Tolić Iva M. , Holder Anthony A. , Roch Karine G. Le , Tromer Eelco C. , Tewari Rita 
Published: February 2023

AbstractMechanisms of cell division are remarkably diverse, suggesting the underlying molecular networks among eukaryotes differ extensively. The Aurora family of kinases orchestrates the process of chromosome segregation and cytokinesis during cell division through precise spatiotemporal regulation of their catalytic activities by distinct scaffolds.Plasmodiumspp., the causative agents of malaria, are unicellular eukaryotes that have three divergent aurora-related kinases (ARKs) and lack most canonical scaffolds/activators. The parasite uses unconventional modes of chromosome segregation during endomitosis and meiosis in sexual transmission stages within mosquito host. This includes a rapid threefold genome replication from 1N to 8N with successive cycles of closed mitosis, spindle formation and chromosome segregation within eight minutes (termed male gametogony). Kinome studies had previously suggested likely essential functions for all threePlasmodiumARKs during asexual mitotic cycles; however, little is known about their location, function, or their scaffolding molecules during unconventional sexual proliferative stages. Using a combination of super-resolution microscopy, mass spectrometry, and live-cell fluorescence imaging, we set out to investigate the role of the atypical Aurora paralog ARK2 to proliferative sexual stages using rodent malaria modelPlasmodium berghei. We find that ARK2 primarily localises to the spindle apparatus in the vicinity of kinetochores during both mitosis and meiosis. Interactomics and co-localisation studies reveal a unique ARK2 scaffold at the spindle including the microtubule plus end-binding protein EB1, lacking conserved Aurora scaffold proteins. Gene function studies indicate complementary functions of ARK2 and EB1 in driving endomitotic divisions and thereby parasite transmission. Our discovery of a novel Aurora kinase spindle scaffold underlines the emerging flexibility of molecular networks to rewire and drive unconventional mechanisms of chromosome segregation in the malaria parasitePlasmodium.
Protracted morphine withdrawal corresponds with sex-specific alterations to motivated behavior and mesoaccumbal subcircuit dopamine cell plasticity
Authors: Gomez Devan M. , Kahl Taytum , Berrington Emily , Hearing Matthew C. 
Published: February 2023

AbstractBackgroundOpioid use disorder is associated with enduring psychological withdrawal symptoms believed to contribute to drug abuse. Amongst these are shifts in motivational states, wherein pursuit of drug consumption exceeds that of non-drug rewards, reinforcing escalated opioid use and relapse vulnerability. A critical regulator of behavioral reinforcement, the mesoaccumbal dopamine (DA) system is thought to be both necessary and sufficient for opioid motivation. However, previous research into its involvement in opioid withdrawal has been limited to acute vs protracted timepoints, global neuroadaptations vs those in subcircuits, and overwhelmingly focused on males vs females.MethodsEvaluations of effort-based motivated behavior for both sucrose and morphine reward were combined with patch clamp electrophysiological assessments of synaptic plasticity within lateral vs medial DA neurons projecting to the lateral vs medial nucleus accumbens shell during protracted morphine withdrawal in male and female mice. Further effects of mesoaccumbal subcircuit inhibition on motivated behavior for sucrose were also measured.ResultsProtracted morphine withdrawal was found to be associated with elevations in morphine seeking, intake, and motivation compared to saline controls in both sexes. Escalation of intake was paralleled by a male-exclusive reduction in motivation for the non-drug reward, sucrose. Male-exclusive neuroadaptations during protracted withdrawal were also found, with reductions in neuronal excitability and increased inhibitory (GABAAR-dependent) synaptic transmission found in lateral ventral tegmental area (VTA) DA neurons projecting to the lateral nucleus accumbens shell, though not in medial DA projections to the medial shell. Finally, chemogenetic inhibition of the lateral but not medial subcircuit was found to significantly reduce motivated responding for sucrose in male morphine-naïve mice.ConclusionsThese data suggest that protracted opioid withdrawal is associated with a sex-independent increase in opioid consumption and motivation. They also suggest that male-specific reductions in motivation for non-drug reward during protracted withdrawal may be driven by a hypoactive state in a lateral mesoaccumbal DA subcircuit driven in part by increased inhibition of DA cells. These insights may be useful in development of therapies that temper withdrawal-associated psychological states predisposed towards prolonged and escalated opioid intake, a major treatment goal for OUD patients.
The Diagnostic and Triage Accuracy of the GPT-3 Artificial Intelligence Model
Authors: Levine David M , Tuwani Rudraksh , Kompa Benjamin , Varma Amita , Finlayson Samuel G. , Mehrotra Ateev , Beam Andrew 
Published: February 2023

ABSTRACTImportanceArtificial intelligence (AI) applications in health care have been effective in many areas of medicine, but they are often trained for a single task using labeled data, making deployment and generalizability challenging. Whether a general-purpose AI language model can perform diagnosis and triage is unknown.ObjectiveCompare the general-purpose Generative Pre-trained Transformer 3 (GPT-3) AI model’s diagnostic and triage performance to attending physicians and lay adults who use the Internet.DesignWe compared the accuracy of GPT-3’s diagnostic and triage ability for 48 validated case vignettes of both common (e.g., viral illness) and severe (e.g., heart attack) conditions to lay people and practicing physicians. Finally, we examined how well calibrated GPT-3’s confidence was for diagnosis and triage.Setting and ParticipantsThe GPT-3 model, a nationally representative sample of lay people, and practicing physicians.ExposureValidated case vignettes (<60 words; <6thgrade reading level).Main Outcomes and MeasuresCorrect diagnosis, correct triage.ResultsAmong all cases, GPT-3 replied with the correct diagnosis in its top 3 for 88% (95% CI, 75% to 94%) of cases, compared to 54% (95% CI, 53% to 55%) for lay individuals (p<0.001) and 96% (95% CI, 94% to 97%) for physicians (p=0.0354). GPT-3 triaged (71% correct; 95% CI, 57% to 82%) similarly to lay individuals (74%; 95% CI, 73% to 75%; p=0.73); both were significantly worse than physicians (91%; 95% CI, 89% to 93%; p<0.001). As measured by the Brier score, GPT-3 confidence in its top prediction was reasonably well-calibrated for diagnosis (Brier score = 0.18) and triage (Brier score = 0.22).Conclusions and RelevanceA general-purpose AI language model without any content-specific training could perform diagnosis at levels close to, but below physicians and better than lay individuals. The model was performed less well on triage, where its performance was closer to that of lay individuals.
A versatile synaptotagmin-1 nanobody provides perturbation-free live synaptic imaging and low linkage-error in super-resolution microscopy
Authors: Villa Real Karine Queiroz Zetune , Mougios Nikolaos , Rehm Ronja , Sograte-Idrissi Shama , Albert László , Rahimi Amir Mohammad , Maidorn Manuel , Hentze Jannik , Martínez-Carranza Markel , Hosseini Hassan , Saal Kim-Ann , Oleksiievets Nazar , Prigge Matthias , Tsukanov Roman , Stenmark Pål , Fornasiero Eugenio F. , Opazo Felipe 
Published: February 2023

AbstractImaging of living synapses has relied for over two decades on the overexpression of synaptic proteins fused to fluorescent reporters. This strategy changes the stoichiometry of synaptic components and ultimately affects synapse physiology. To overcome these limitations, here we introduce a nanobody that binds the calcium sensor synaptotagmin-1 (NbSyt1). This nanobody functions in living neurons as an intrabody (iNbSyt1) and is minimally invasive, leaving synaptic transmission almost unaffected, as demonstrated by the crystal structure of the NbSyt1 bound to synaptotagmin-1 and by our physiological data. Its single-domain nature enables the generation of protein-based fluorescent reporters, as we showcase here by measuring spatially-localized presynaptic Ca2+with an NbSyt1-jGCaMP8 chimera. Moreover, its small size makes the NbSyt1 ideal for various super-resolution imaging methods. Overall, NbSyt1 is a versatile binder that will enable imaging in cellular and molecular neuroscience at a higher precision than possible in the past, over multiple spatiotemporal scales.
ARHGAP29 is required for keratinocyte proliferation and migration
Authors: Reeb Tanner , Rhea Lindsey , Adelizzi Emily , Garnica Bailey , Dunnwald Elliot , Dunnwald Martine 
Published: February 2023

AbstractBACKGROUNDRhoA GTPase plays critical roles in actin cytoskeletal remodeling required for controlling a diverse range of cellular functions including cell proliferation, cell adhesions, migration and changes in cell shape. RhoA cycles between an active GTP-bound and an inactive GDP-bound form, a process that is regulated by guanine nucleotide exchange factors (GEFs), and GTPase-activating proteins (GAPs). ARHGAP29 is a GAP expressed in keratinocytes of the skin and is decreased in the absence of Interferon Regulator Factor 6, a critical regulator of cell proliferation and migration. However, the role for ARHGAP29 in keratinocyte biology is unknown.RESULTSNovel ARHGAP29 knockdown keratinocyte cell lines were generated using both CRISPR/Cas9 and shRNA technologies. Knockdown cells exhibited significant reduction of ARHGAP29 protein (50-80%) and displayed increased filamentous actin (stress fibers), phospho-myosin light chain (contractility), cell area and population doubling time. Furthermore, we found that ARHGAP29 knockdown keratinocytes displayed significant delays in scratch wound closure in both single cell and collective cell migration conditions. Particularly, our results show a reduction in path lengths, speed, directionality and persistence in keratinocytes with reduced ARHGAP29. The delay in scratch closure was rescued by both adding back ARHGAP29 or adding a ROCK inhibitor to ARHGAP29 knockdown cells.CONCLUSIONSThese data demonstrate that ARHGAP29 is required for keratinocyte morphology, proliferation and migration mediated through the RhoA pathway.
Reduced dimension stimulus decoding and column-based modeling reveal architectural differences of primary somatosensory finger maps between younger and older adults
Authors: Kalyani Avinash , Contier Oliver , Klemm Lisa , Azañon Elena , Schreiber Stefanie , Speck Oliver , Reichert Christoph , Kuehn Esther 
Published: February 2023

AbstractThe primary somatosensory cortex (SI) contains fine-grained tactile representations of the body, arranged in an orderly fashion. Using ultra-high resolution fMRI data to describe such detailed individual topographic maps or to detect group differences is challenging, because group alignment often does not preserve the high spatial detail of the data. Here, we use shared response modeling (SRM), a technique that allows group analyses by mapping individual stimulus-driven responses to a lower dimensional shared feature space, to detect age-related differences in sensory representations between younger and older adults using 7T-fMRI data. Using this method, we show that finger representations are more precise in Brodmann-Area (BA) 3b and BA1 compared to BA2 and motor areas, and that this hierarchical processing is preserved across age groups. By combining SRM with column-based decoding (C-SRM), we further show that the number of columns that optimally describes finger maps in SI is higher in younger compared to older adults in BA1, indicating a greater columnar size in older adults’ SI. Taken together, we conclude that SRM is suitable for finding fine-grained group differences in SI fMRI data at ultra-high-resolution, and we provide first evidence that the columnar architecture of a functional area changes with increasing age.
Homocysteine accelerates hepatocyte autophagy by upregulation of TFEB via DNMT3b-mediated DNA hypomethylation
Authors: Yang Anning , Zeng Wen , Hao Yinju , Zhang Hongwen , Wang Qingqing , Sun Yue , Quan Shangkun , Ding Ning , Yang Xiaoling , Sun Jianmin , Zhang Huiping , Liu Bin , Jiao Yun , Wu Kai , Jiang Yideng 
Published: February 2023

AbstractAutophagy plays a critical role in the physiology and pathophysiology of hepatocytes. High levels of homocysteine (Hcy) promote autophagy in hepatocytes, but the underlying mechanism is still unknown. Here, we investigated the relation between Hcy increased autophagy levels and the expression of nuclear transcription factor EB (TFEB). We demonstrate that Hcy increased autophagy levels is mediated by upregulation of TFEB. Silencing TFEB decreases the autophagy-related protein LC3BII/I and increases p62 expression levels in hepatocytes after exposure to Hcy. Moreover, the effect of Hcy on the expression of TFEB is regulated by hypomethylation of TFEB promoter catalyzed by DNA methyltransferase 3b (DNMT3b). In summary, this study shows that Hcy can activate autophagy by inhibiting DNMT3b-mediated DNA methylation and upregulating TFEB expression. These findings provide another new mechanism for Hcy-induced autophagy in hepatocytes.
Single cell ATAC sequencing identifies sleepy macrophages during reciprocity of cytokines inL.majorinfection
Authors: Khandibharad Shweta , Kharat Komal , Singh Shailza 
Published: February 2023

AbstractHallmark for macrophages is their ability to possess plasticity which enables them to respond to changing microenvironment.Leishmaniatakes use of the phenotypic plasticity of macrophages to create favorable position for intracellular survival and persistent infection through regulatory cytokine like IL10. However, these effector cells can eliminate infection through modulation of critical cytokines such as IL12 and key players involved in its production. Using sophisticated tool of single cell ATAC sequencing we analyzed the regulatory axis of IL10 and IL12 in time dependent manner forL.majorinfection in macrophages. We recognized the cellular heterogeneity post infection with the regulators of IL10 and IL12 and observed a reciprocal relationship between them. Our prominent findings also exposed sleepy macrophages and its role in IL10 and IL12 reciprocity. To summarize, role of NFAT5 was vital in identification of sleepy macrophages which is a transient state where transcription factors controlled the epigenetic remodeling and expression of genes involved in pro-inflammatory cytokine production and recruitment of immune cells.Abstract FigureGraphical abstract summary of single cell ATAC sequencing forL.majorinfected RAW264.7 mouse macrophage cell line. (A) Reciprocal relationship identified in cell populations which is governed through chromatin remodeling. (B) Single cell ATAC pipeline for analysis of dataset (C) Identification of sleepy macrophages which may play potential role in reciprocity.
Glucose deprivation promotes pseudo-hypoxia and de-differentiation in lung adenocarcinoma
Authors: Saggese Pasquale , Pandey Aparamita , Fung Eileen , Hall Abbie , Yanagawa Jane , Rodriguez Erika F. , Grogan Tristan R. , Giurato Giorgio , Nassa Giovanni , Salvati Annamaria , Weisz Alessandro , Dubinett Steven M. , Scafoglio Claudio 
Published: February 2023

ABSTRACTIncreased utilization of glucose is a hallmark of cancer. Several studies are investigating the efficacy of glucose restriction by glucose transporter blockade or glycolysis inhibition. However, the adaptations of cancer cells to glucose restriction are unknown. Here, we report the discovery that glucose restriction in lung adenocarcinoma (LUAD) induces cancer cell de-differentiation, leading to a more aggressive phenotype. Glucose deprivation causes a reduction in alpha-ketoglutarate (αKG), leading to attenuated activity of αKG-dependent histone demethylases and histone hypermethylation. We further show that this de-differentiated phenotype depends on unbalanced EZH2 activity, causing inhibition of prolyl-hydroxylase PHD3 and increased expression of hypoxia inducible factor 1α (HIF1α), triggering epithelial to mesenchymal transition. Finally, we identified an HIF1α-dependent transcriptional signature with prognostic significance in human LUAD. Our studies further current knowledge of the relationship between glucose metabolism and cell differentiation in cancer, characterizing the epigenetic adaptation of cancer cells to glucose deprivation and identifying novel targets to prevent the development of resistance to therapies targeting glucose metabolism.
Intra-ripple frequency accommodation in an inhibitory network model for hippocampal ripple oscillations
Authors: Schieferstein Natalie , Schwalger Tilo , Lindner Benjamin , Kempter Richard 
Published: February 2023

AbstractHippocampal ripple oscillations have been implicated in important cognitive functions such as memory consolidation and planning. Multiple computational models have been proposed to explain the emergence of ripple oscillations, relying either on excitation or inhibition as the main pacemaker. Nevertheless, the generating mechanism of ripples remains unclear. An interesting dynamical feature of experimentally measured ripples, which may advance model selection, is intra-ripple frequency accommodation (IFA): a decay of the instantaneous ripple frequency over the course of a ripple event. So far, only the “bifurcation-based” inhibition-first model, which is based on delayed inhibitory synaptic coupling, has been shown to reproduce IFA. Here we use an analytical mean-field approach and numerical simulations of a leaky integrate-and-fire spiking network to explain the mechanism of IFA. We develop a drift-based approximation for the oscillation dynamics of the population rate and the mean membrane potential of interneurons under strong drive and strong inhibitory coupling. We demonstrate that IFA arises due to a speed-dependent hysteresis effect in the dynamics of the mean membrane potential, when the interneurons receive transient, sharp wave-associated excitation. We thus predict that the IFA asymmetry vanishes in the limit of slowly changing drive, but is otherwise a robust feature of the bifurcation-based inhibition-first ripple model.
Engineering sensory ganglion multicellular system to model tissue nerve ingrowth
Authors: Ma Junxuan , Tognato Riccardo , Eglauf Janick , Grad Sibylle , Alini Mauro , Serra Tiziano 
Published: February 2023

AbstractDiscogenic pain is associated with deep nerve ingrowth in annulus fibrosus tissue (AF) of intervertebral disc (IVD). To model AF nerve ingrowth, primary bovine dorsal root ganglion (DRG) micro-scale tissue units are spatially organized around an AF explant by mild hydrodynamic forces within a collagen matrix. This results in a densely packed multicellular system mimicking the native DRG tissue morphology and a controlled AF-neuron distance. Such a multicellular organization is essential to evolve populational-level cellular functions andin vivo-like morphologies. Pro-inflammatory cytokine-primed AF demonstrates its neurotrophic and neurotropic effects on nociceptor axons. Both effects depend on the AF-neuron distance underpinning the role of recapitulating inter-tissue/organ anatomical proximity when investigating their crosstalk. This is the firstin vitromodel studying AF nerve ingrowth by engineering mature and large animal tissues in a morphologically and physiologically relevant environment. Our new approach can be used to biofabricate multi-tissue/organ models for untangling pathophysiological conditions and develop novel therapies.