bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth regulation bringing modularity to morphogenesis of complex three-dimensional exoskeletons
Authors: Ito Hiroshi C. , Uchiumi Yu 
Published: May 2024

AbstractDiverse three-dimensional morphologies of arthropods’ appendages, including beetle horns, are formed through the non-uniform growth of epidermis. Prior to moulting, epidermal tissue peels off from the old cuticle and grows non-uniformly to shape protruding appendages, which are often branching, curving, or twisting, from the planar epidermis. This non-uniform growth is possibly regulated by the distribution of morphogens on the epidermal cell sheet. Previous studies have identified molecules and signalling pathways related to such morphogenesis; however, how local regulation of cell sheet growth can transform planar epidermis globally into complex three-dimensional structures, such as beetle horns, remains unclear. To reveal the relationship between epidermal growth regulation and generated structures, this study theoretically examined how various shapes can be generated from planar epidermis under a deductive growth model that corresponds morphogen distributions to non-uniform growth on tissue. The results show that the heterochronic expression of multiple morphogens can flexibly fuse multiple simple shapes to generate various structures emulating complex appendages of beetles. These findings indicate that morphogenesis through such a mechanism may have developmental stability and modularity, providing insights into the evolution of the diverse morphology of arthropods.
Physical confinement selectively favours bacterial growth based on cell shape
Authors: Sreepadmanabh M , Ganesh Meenakshi , Sanjenbam Pratibha , Kurzthaler Christina , Agashe Deepa , Bhattacharjee Tapomoy 
Published: May 2024

AbstractHow are bacterial communities altered by changes in their microenvironment? Evidence from homogeneous liquid or flat plate cultures implicates biochemical cues — such as variation in nutrient composition1,2, response to chemoattractants and toxins3,4, and inter-species signalling5,6— as the primary modes of bacterial interaction with their microenvironment. However, these systems fail to capture the effect of physical confinement on bacteria in their natural habitats. Bacterial niches like the pores of soil, mucus, and infected tissues are disordered microenvironments with material properties defined by their internal pore sizes and shear moduli7–11. Here, using three-dimensional matrices that match the viscoelastic properties of gut mucus, we test how altering the physical properties of their microenvironment influences bacterial growth under confinement. We find that low aspect-ratio bacteria form compact, spherical colonies under confinement while high aspect-ratio bacteria push their progenies further outwards to create elongated colonies with a higher surface area, enabling increased access to nutrients. As a result, the population level growth of high aspect-ratio bacteria is more robust to increased physical confinement compared to that of low aspect-ratio bacteria. Thus, our results capture experimental evidence showing that physical constraints can play a selective role in bacterial growth based on cell shape.
Chronic ethanol exposure produces long-lasting, subregion-specific physiological adaptations in RMTg-projecting mPFC neurons
Authors: Przybysz Kathryn R , Shillinglaw Joel E , Wheeler Shannon R , Glover Elizabeth J 
Published: May 2024

AbstractChronic ethanol exposure produces neuroadaptations in the medial prefrontal cortex (mPFC) which facilitate the maladaptive behaviors interfering with recovery from alcohol use disorder. Despite evidence that different cortico-subcortical projections play distinct roles in behavior, few studies have examined the physiological effects of chronic ethanol at the circuit level. The rostromedial tegmental nucleus (RMTg) is a GABAergic midbrain region involved in aversive signaling and is functionally altered by chronic ethanol exposure. Our recent work identified a dense input from the mPFC to the RMTg, yet the effects of chronic ethanol exposure on this circuitry is unknown. In the current study, we examined physiological changes after chronic ethanol exposure in prelimbic (PL) and infralimbic (IL) mPFC neurons projecting to the RMTg. Adult male Long-Evans rats were injected with fluorescent retrobeads into the RMTg and rendered dependent using a 14-day chronic intermittent ethanol (CIE) vapor exposure paradigm. Whole-cell patch-clamp electrophysiological recordings were performed in fluorescently-labeled (RMTg-projecting) and -unlabeled (projection-undefined) layer 5 pyramidal neurons 7-10 days following ethanol exposure. CIE significantly increased intrinsic excitability as well as excitatory and inhibitory synaptic drive in RMTg-projecting IL neurons. In contrast, no lasting changes in excitability were observed in RMTg-projecting PL neurons, although a CIE-induced reduction in excitability was observed in projection-undefined PL neurons. CIE also increased excitatory synaptic drive in RMTg-projecting PL neurons. These data uncover novel subregion- and circuit-specific neuroadaptations in the mPFC following chronic ethanol exposure and reveal that the IL mPFC-RMTg projection is uniquely vulnerable to long-lasting effects of chronic ethanol.
Targeting SCD triggers lipotoxicity of cancer cells and enhances anti-tumor immunity in breast cancer brain metastasis mouse models
Authors: Sammarco Alessandro , Guerra Giorgia , Eyme Katharina M. , Kennewick Kelly , Qiao Yu , Hokayem Joelle El , Williams Kevin J. , Su Baolong , Zappulli Valentina , Bensinger Steven J. , Badr Christian E. 
Published: May 2024

AbstractBreast cancer brain metastases (BCBM) are a significant cause of mortality and are incurable. Thus, identifying BCBM targets that reduce morbidity and mortality is critical. BCBM upregulate Stearoyl-CoA Desaturase (SCD), an enzyme that catalyzes the synthesis of monounsaturated fatty acids, suggesting a potential metabolic vulnerability of BCBM. In this study, we tested the effect of a brain-penetrant clinical-stage inhibitor of SCD (SCDi), on breast cancer cells and mouse models of BCBM. Lipidomics, qPCR, and western blot were used to study the in vitro effects of SCDi. Single-cell RNA sequencing was used to explore the effects of SCDi on cancer and immune cells in a BCBM mouse model. Pharmacological inhibition of SCD markedly reshaped the lipidome of breast cancer cells and resulted in endoplasmic reticulum stress, DNA damage, loss of DNA damage repair, and cytotoxicity. Importantly, SCDi alone or combined with a PARP inhibitor prolonged the survival of BCBM-bearing mice. When tested in a syngeneic mouse model of BCBM, scRNAseq revealed that pharmacological inhibition of SCD enhanced antigen presentation by dendritic cells, was associated with a higher interferon signaling, increased the infiltration of cytotoxic T cells, and decreased the proportion of exhausted T cells and regulatory T cells in the tumor microenvironment (TME). Additionally, pharmacological inhibition of SCD decreased engagement of immunosuppressive pathways, including the PD-1:PD-L1/PD-L2 and PVR/TIGIT axes. These findings suggest that SCD inhibition could be an effective strategy to intrinsically reduce tumor growth and reprogram anti-tumor immunity in the brain microenvironment to treat BCBM.
Lipid availability influences ferroptosis sensitivity in cancer cells by regulating polyunsaturated fatty acid trafficking
Authors: Sokol Kelly H. , Lee Cameron J. , Rogers Thomas J. , Waldhart Althea , Ellis Abigail E. , Madireddy Sahithi , Daniels Samuel R. , Ye Xinyu , Olesnavich Mary , Johnson Amy , Furness Benjamin R. , Sheldon Ryan D. , Lien Evan C. 
Published: May 2024

ABSTRACTFerroptosis is a form of cell death caused by lipid peroxidation that is emerging as a target for cancer therapy, highlighting the need to identify factors that govern ferroptosis susceptibility. Lipid peroxidation occurs primarily on phospholipids containing polyunsaturated fatty acids (PUFAs). Here, we show that even though extracellular lipid limitation reduces cellular PUFA levels, lipid-starved cancer cells are paradoxically more sensitive to ferroptosis. Using mass spectrometry-based lipidomics with stable isotope fatty acid labeling, we show that lipid limitation induces a fatty acid trafficking pathway in which PUFAs are liberated from triglycerides to synthesize highly unsaturated PUFAs such as arachidonic acid and adrenic acid. These PUFAs then accumulate in phospholipids, particularly ether phospholipids, to promote ferroptosis sensitivity. Therefore, PUFA levels within cancer cells do not necessarily correlate with ferroptosis susceptibility. Rather, how cancer cells respond to extracellular lipid levels by trafficking PUFAs into proper phospholipid pools dictates their sensitivity to ferroptosis.
Temperature-dependent intracellular crystallization of firefly luciferase in mammalian cells is suppressed by D-luciferin and stabilizing inhibitors
Authors: Hasegawa Haruki 
Published: May 2024

AbstractFirefly luciferase (Fluc) fromPhotinus pyralisis one of the most widely used reporter proteins in biomedical research. Despite its widespread use, Fluc’s protein phase transition behaviors and phase separation characteristics have not received much attention. Current research uncovers Fluc’s intrinsic property to phase separate in mammalian cells upon a simple cell culture temperature change. Specifically, Fluc spontaneously produced needle-shaped crystal-like inclusion bodies upon temperature shift to the hypothermic temperatures ranging from 25°C to 31°C. The crystal-like inclusion bodies were not associated with or surrounded by membranous organelles and were likely built from the cytosolic pool of Fluc. Furthermore, the crystal-like inclusion formation was suppressed when cells were cultured in the presence of D-luciferin and its synthetic analog, as well as the benzothiazole family of so-called stabilizing inhibitors. These two classes of compounds inhibited intracellular Fluc crystallization by different modes of action as they had contrasting effects on steady-state luciferase protein accumulation levels. This study suggests that, under substrate insufficient conditions, the excess Fluc phase separates into a crystal-like state that can modulate intracellular soluble enzyme availability and protein turnover rate.
Stigma among Ebola Disease Survivors in Mubende and Kassanda districts, Central Uganda, 2022
Authors: Zalwango Gorreti Marie , Paige Sarah , Migisha Richard , Nakafeero Simbwa Brenda , Nsubuga Edirisa Junior , Asio Alice , Kabami Zainah , Zalwango Jane Frances , Kawungezi Peter Chris , Wanyana Mercy Wendy , King Patrick , Naiga Hellen Nelly , Agaba Brian , Zavuga Robert , Earle-Richardson Giulia , Kwesiga Benon , Bulage Lilian , Kadobera Daniel , Ario Alex Riolexus , Harris Julie R. 
Published: May 2024

AbstractBackgroundEbola disease survivors often experience stigma in multiple forms, including felt (perceived) stigma, enacted (action-based) stigma, and structural (institutional) stigma. On September 20, 2022, Uganda declared a Sudan Virus Disease (SVD, caused bySudan ebolavirus) outbreak after a patient with confirmed Sudan virus (SUDV) infection was identified in Mubende District. The outbreak led to 142 confirmed and 22 probable cases over the next two months. We examined the types of stigma experienced by survivors and their household members and its effect on their well-being.MethodsWe conducted a qualitative study during January 2023 in Mubende and Kassanda Districts. We conducted in-depth and key informant interviews with ten SVD survivors, ten household members of SVD survivors, and ten key informants (district officials and health workers in the affected communities). Interviews were recorded, translated, transcribed, and analyzed thematically.ResultsSurvivors reported experiencing isolation and rejection by community members and loss of work. They reported being denied purchases at shops or having their money collected in a basket and disinfected (enacted stigma), which led to self-isolation (felt stigma). Educational institutions denied admission to some students from affected homes, while parents of children in some affected families stopped sending children to school due to verbal abuse from students and teachers (structural stigma). Prolonged SVD symptoms and additional attention to survivors from responders (including home visits by health workers, public distribution of support items, and conspicuous transport from home to the survivor’s clinic) were perceived as aggravating both felt and enacted stigma. Even after the outbreak had been declared over, survivors felt that they were still considered a threat to the community.ConclusionSurvivors experienced felt stigma, enacted stigma, and structural stigma. Strengthening community engagement to counteract stigma, rethinking response activities that aggravate stigma, management of long-term SVD symptoms for survivors, integrated response interventions by partners, private distribution of support items, and increasing awareness and sensitization through video messages could reduce stigma among persons affected in future similar outbreaks.
A 20-year experience with initial and repeated electro- and echocardiographic screening in youth, athletes, and adults revealing high number of abnormalities
Authors: Bates Sharon , Movahed Mohammad Reza 
Published: May 2024

AbstractBackgroundTo further analyze the impacts, findings, and modalities of multiple cardiac screenings to answer the question – are multiple screens necessary in youth?MethodsOver 20 years, the Anthony Bates Foundation (ABF) has offered free and low-cost cardiac screenings to youth and their families nationwide. The volunteer force has provided blood pressure, and ultrasound tests to participants throughout the 20 years. After year 7, electrocardiograms were added to the screening.ResultsOver the 20 years, ABF abnormal findings held steady between 10 - 13%, with Potential Life-Threatening (PLT) findings at 2.5%. The participants that have experienced multiple screening tests on average would repeat within 2.5 years, have abnormal findings at 31.84%, PLT at 11.43%, and total echocardiography-related abnormal findings at 16.82%. The variance between male and female attendance by age is also noted during the review of ABF repeat screened data. Male attendance was at 59.65% and female 40.35%. The abnormality rate of males for the first visit was 10.9% followed by the second visit of 18.80%. The abnormality rate of females for the first visit was 12.22% followed by the second visit of 17.09%. A detailed analysis of abnormal findings is presented in this manuscript.ConclusionsCardiac screening involving multiple repeated screenings appears to be effective in detecting increasing numbers of abnormal findings that can be lifesaving.
Noninvasive time-lapse 3D subcellular analysis of embryo development for machine learning-enabled prediction of blastocyst formation
Authors: Lee Chungha , Kim Geon , Shin Taeseop , Lee Sangho , Kim Jae Young , Choi Kyoung Hee , Do Jieun , Park Jaehyeong , Do Jaephil , Kim Ji Hyang , Park YongKeun 
Published: May 2024

AbstractIn developmental biology and in vitro fertilization (IVF), image-based assessment of embryos is pivotal. Traditional methods in clinical IVF have been constrained to 2D morpho-kinetic profiling and manual selection, hindered by the absence of noninvasive techniques for quantitative 3D imaging over extended durations. Here, we overcome these limitations by employing low-coherence holotomography to monitor mouse preimplantation embryo development from the 2-cell stage to the expanded blastocyst. This approach enables the generation of 3D refractive index tomograms of unlabeled embryos, facilitating the observation of subcellular developmental dynamics. We investigated the 3D spatiotemporal profiles of embryo development, identifying key morpho-kinetic parameters that distinguish between embryos with differing developmental outcomes—specifically, Grade A embryos that successfully progressed to expanded blastocysts within 72 hours, and Grade C embryos that did not. Using machine learning, we demonstrate the 3D morpho-kinetic parameters can offer a noninvasive, quantitative framework for predicting embryos with high developmental potential.
Drosophilalarvae demonstrate associative learning and memory in response to thermal conditioning
Authors: Polizos Nikolaos T. , Dancausse Stephanie , Rios Consuelo , Klein Mason 
Published: May 2024

AbstractOrganisms have evolved the ability to detect, process, and respond to many different surrounding stimuli in order to successfully navigate their environments. Sensory experiences can also be stored and referenced in the form of memory. TheDrosophilalarva is a simple model organism that can store associative memories during classical conditioning, and is well-suited for studying learning and memory at a fundamental level. Much progress has been made in understanding larval learning behavior and the associated neural circuitry for olfactory conditioning, but other sensory systems are relatively unexplored. Here, we investigate memory formation in larvae treated with a temperature-based associative conditioning protocol, pairing normally neutral temperatures with appetitive (fructose, FRU) or aversive (salt, NaCl) stimuli. Associative memory is tested using thermal gradient geometries, and we quantify navigation strength towards or away from conditioned temperatures. We find that larvae demonstrate short-term associative learning. They navigate towards warmer or colder temperatures paired with FRU, and away from warmer temperatures paired with NaCl. These results, especially when combined with future investigations of thermal memory circuitry in larvae, should provide broader insight into how sensory stimuli are encoded and retrieved in insects and more complex systems.
Impaired yolk sac NAD metabolism disrupts murine embryogenesis with relevance to human birth defects
Authors: Bozon Kayleigh , Cuny Hartmut , Sheng Delicia Z. , Martin Ella M. M. A. , Sipka Alena , Young Paul , Humphreys David T. , Dunwoodie Sally L. 
Published: May 2024

AbstractCongenital malformations can originate from numerous genetic or non-genetic factors but in most cases the causes are unknown. Genetic disruption of nicotinamide adenine dinucleotide (NAD)de novosynthesis causes multiple malformations, collectively termed Congenital NAD Deficiency Disorder (CNDD), highlighting the necessity of this pathway during embryogenesis. Previous work in mice shows that NAD deficiency perturbs embryonic development specifically when organs are forming. While the pathway is predominantly active in the liver postnatally, the site of activity prior to and during organogenesis is unknown.Here, we used a mouse model of human CNDD and assessed pathway functionality in embryonic livers and extraembryonic tissues via gene expression, enzyme activity and metabolic analyses. We found that the extra-embryonic visceral yolk sac endoderm exclusively synthesises NADde novoduring early organogenesis before the embryonic liver takes over this function. Under CNDD-inducing conditions, visceral yolk sacs had reduced NAD levels and altered NAD-related metabolic profiles, affecting embryo metabolism. Expression of requisite pathway genes is conserved in the equivalent yolk sac cell type in humans.Our findings show that visceral yolk sac-mediated NADde novosynthesis activity is essential for mouse embryogenesis and its perturbation causes CNDD. As mouse and human yolk sacs are functionally homologous, our data improve the understanding of human congenital malformation causation.
Daily Acute Intermittent Hypoxia Elicits Age & Sex-Dependent Changes in Molecules Regulating Phrenic Motor Plasticity
Authors: Nair Jayakrishnan , Marciante Alexendria B. , Lurk Carter , Kelly Mia N. , Mitchell Gordon S. 
Published: May 2024

ABSTRACTAcute intermittent hypoxia (AIH) elicits a form of respiratory motor plasticity known as phrenic long-term facilitation (LTF). Repetitive daily AIH (dAIH) exposure enhances phrenic LTF, demonstrating a form of metaplasticity. Two additional factors impacting phrenic LTF are age and sex. For example, moderate AIH-induced phrenic LTF decreases with age in males, but increases in middle-aged females. However, little is known concerning cellular mechanisms of dAIH effects or age-dependent sexual dimorphism in phrenic LTF. Moderate AIH elicits distinct signaling cascades within phrenic motor neurons initiated by 5HT2 receptors (Q pathway)versusadenosine 2A or 5HT7 receptors (S pathway), respectively. The Q and S pathways interactviamutual crosstalk inhibition, a powerful regulator of phrenic LTF. To test the hypothesis that dAIH, age and sex effects on phrenic LTF are associated with differential expression of molecules known to regulate the Q and S pathways, we assessed mRNA of key regulatory molecules in ventral cervical homogenates from spinal segments containing the phrenic motor nucleus from young (3 month) and middle-aged (12 month) male and female Sprague-Dawley rats. Since CNS estrogen levels impact molecules regulating the Q and/or S pathways, mRNA was correlated with serum estradiol. Rats (n=8/group) were exposed to sham (21% O2) or dAIH (15, 1 min episodes of 10.5% inspired O2per day) for 14 days, and sacrificed 24 hours post-dAIH. mRNA for molecules known to regulate phrenic LTF were assessedviaRT PCR, including: brain derived neurotrophic factor (Bdnf); serotonin 2A (Htr2a); 2B (Htr2b); and (Htr7) receptors; adenosine 2a (Adora2a) receptors; exchange protein activated by cAMP (Epac1); p38 MAP kinase [Mapk14(α) &Mapk11(β)]; PKA catalytic subunit (Prkaa1); PKA regulatory subunit (Prkar1a); fractalkine (Cx3cl1); phosphodiesterase type 4 (Pde4b); NAPDH–gp91 (Cybb) and p47 (ncf1); and the PKCδ isoform (Prkcd). Significantly higherPde4b,Adora2a, andPrkcdmRNA were found in young and middle-aged femalesversusage-matched males;Epac1was elevated, but only in young females (p<0.001).Ncf1was increased in middle-aged versus young adult rats of both sexes (p<0.01).Ncf1, Cx3cl1,Adora2aandPrkcdmRNA were reduced by dAIH in middle-aged females (p<0.01), but not other groups. Serum estradiol levels positively correlated withEpac1(r2=0.29, p=0.002),Mapk14(r2=0.31, p=0.001),Mapk11(r2=0.20, p=0.014), andPrkar1a(r2=0.20 p=0.013) mRNA. With higher serum estradiol levels, dAIH decreasedMapk14mRNA (slope difference p=0.001). Thus, age, sex and dAIH preconditioning influence molecules known to regulate the Q and S pathways to phrenic motor facilitation. These novel findings advance our understanding of phrenic LTF, and inform translational research concerning the therapeutic potential of dAIH to treat breathing deficits in individuals of different ages or sex.
Spectrograms of Ivory-billed Woodpecker (Campephilus principalis) kent sounds from seven expeditions show 587 Hertz as a pattern
Authors: Williams John D ,   Mission Ivorybill
Published: May 2024

AbstractAlthough the Ivory-billed Woodpecker is widely considered to be extinct, expeditions led by professional ornithologists have acquired visual, video, and audio evidence since 1968, with increases in data since 2000. Audio evidence for “kent” sounds (n=150) were examined for commonality; this was found to be true with a pattern at 587 Hz that suggests a morphological basis. Differences from other species were found on spectrograms. The patterns extend to different states and years and reinforces that the species persists.