bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Neuroprotective Effects of Estrogen in an Alzheimer’s Disease Hypothalamic Cell Line
Authors: Hindieh Jennifer Grace , Persaud Nikita , Cooperstein Deborah , Chakraborty Tandra R. , Chakraborty Sanjoy 
Published: April 2020

Alzheimer’s Disease (AD), is a neurodegenerative disease affecting memory and cognition, eventually leading to dementia. Two of the most notable hallmarks of AD are the aggregation and depositing of beta‐amyloid fibrils as extracellular plaques as well as the intracellular accumulation of Tau as neurofibrillary tangles in the brain. Research suggests a possible neuroprotective role of the female sex hormone estrogen in neurodegenerative diseases, including AD. Using established AD cell line SH‐SY5Y as a control and N38 hypothalamic cells as an experimental cell line, AD will be modeled in vitro by incubating with synthetic, oligomerized beta‐amyloid, and subsequently, treating the culture with estrogen to observe its efficacy as a neuroprotective reagent. A western blot assay will be used to confirm the presence of total tau, before and after treatment. We hypothesize that cells treated with Aβ42 will express larger amounts of total Tau in contrast to cells treated with both estrogen and amyloid. Preliminary results confirm the presence of Tau in SH‐SY5Y and N38 cell line. Tau‐46 was used as the primary antibody, GAM‐HRP as a secondary antibody, with GADPH used as a control. Supplemental bioassays, MTT and LDH, were performed to determine cell viability, cytotoxicity, and proliferation. Preliminary results in MTT with N38 cells showed that Aβ42 reduced mitochondrial activity within 24hrs. These results also indicated estrogens’ neuroprotective capabilities within hypothalamic cells by counteracting the negative effect of Aβ42. Through analysis of both quantitative and qualitative data, there will be further clarification of the possible neuroprotective nature of estrogen with regards to beta amyloid plaque toxicity.Support or Funding InformationAdelphi University & New York City College of Technology
Exploring the Structural Stability and Assembly Mechanism of Hydrophobin Proteins
Authors: Vergunst Kathleen , Langelaan David N. 
Published: April 2020

Hydrophobins are small, globular proteins with amphiphilic character that are produced and secreted by filamentous fungi. At hydrophobic‐hydrophilic interfaces they self‐assemble into durable amyloid‐containing structures, called rodlets, which create protective, water repellent coatings for fungal spores. Current models of hydrophobin self‐assembly predict that hydrophobin monomers undergo a conformational change at a hydrophobic‐hydrophilic interface and integrate into a growing rodlet, however the mechanistic details of rodlet assembly are unknown. To investigate the assembly mechanism of hydrophobins, we carried out stability studies with SC16, a hydrophobin isolated from Schizophyllum commune. SC16 was recombinantly expressed using E. coli and purified by immobilized Ni2+ affinity chromatography. NMR spectroscopy was used to determine that the structure of SC16 was minimally perturbed by denaturing (8 M urea) or reducing (2 mM DTT) conditions. Gel filtration chromatography indicated that in solution SC16 exists as a tetramer, suggesting that rodlet assembly does not initiate from hydrophobin monomers. Mutant forms of SC16 are being employed to determine the sequences and conformational changes required for rodlet assembly, with gel filtration chromatography used to determine the multimeric state, thioflavin T assays to quantify amyloid formation, and electron microscopy to visualize rodlet formation. X‐ray crystallography is being used to further characterize the tetrameric structure of SC16. Determining which hydrophobin sequences are responsible for self‐assembly will allow the rational modification of hydrophobins to add new functionalities or influence their self‐assembly.Support or Funding InformationNSERC, Dalhousie University Faculty of Medicine, Nova Scotia Research Foundation, BioActives CREATE
Sympathetic Preganglionic Neurons (SPNs): a Promising Target to Regain Cardiorespiratory Control in Spinal Cord Injured (SCI) Patients
Authors: Lopes Luana Tenorio , Barioni Nicole Orsi , Yang Hannah , Wilson Richard 
Published: April 2020

BackgroundThe consequences of spinal cord injuries (SCI) are massive and become more severe with higher levels of injury. Lesions located on cervical portions, specifically between C1‐C3 cause an interruption of the descending bulbospinal pathways. These pathways include a key component of the neural control of respiration, linking the brainstem breathing rhythm generator with phrenic motor neurons that activate the diaphragm. Disruption to these pathways result in respiratory muscle paresis and/or paralysis, requiring mechanical ventilation. Respiratory complications, such as pneumonia and atelectasis complicate the process of weaning patients from ventilators, contributing to patient mortality. Previous data collected in the Wilson lab demonstrated that sympathetic preganglionic neurons (SPNs) located at the thoracic spinal cord have remarkable oxygen and pressure‐sensitive capabilities. Here, we hypothesized that SPNs can stimulate phrenic motor neurons independent of the brainstem.AimTo study the novel direct influence of SPNs on the phrenic motor nucleus.MethodsAn in situ artificially‐perfused cervico‐thoracic rat spinal cord preparation was used to record phrenic and splanchnic nerve activity while having the cervical and thoracic spinal cord separately perfused. This approach allowed us to selectively expose the thoracic segment to acute hypoxia (30 Torr; 10 min) in order to observe if cardiorespiratory responses elicited by the SPN’s could stimulate phrenic motor neurons located at the cervical spinal cord. Additionally, we recorded the electromyography activity from the diaphragm during hypoxia and ischemia (0 mmHg; 10 min).ResultsThe results demonstrated that stimulation of the SPNs with hypoxia evoked phrenic nerve and diaphragm activity. This indicates that even without inputs from the brainstem, SPNs are responsive to hypoxia and ischemia and might have capability to stimulate phrenic motor neurons.ConclusionThe implications of these findings point to the thoracic SPNs as a unique and promising target to regain cardiorespiratory control in SCI patients. Further pharmacological investigations may reveal effective treatment strategies to improve life quality and reduce mortality of SCI patients.Support or Funding InformationAlberta Innovates Health Solutions (LL), Eyes High (NB), NSERC (HY), Canadian Institute of Health Research (RW).
Cannabidiol Induces Apoptosis and Perturbs Mitochondrial Function in both Human and Canine Glioma Cells
Authors: Gross Chase , Ramirez Dominique , Dickinson Peter , Gustafson Daniel , McGrath Stephanie 
Published: April 2020

The use of cannabidiol (CBD), the major non‐psychoactive compound derived from cannabis, as a nutraceutical in both human and veterinary medicine has increased steadily within the past ten years despite a lack of scientific evidence for its effectiveness. Of the cornucopia of ailments that CBD supposedly treats, epilepsy, pain, and cancer remain prominent areas of interest to scientists and the general public. In the world of cancer research, several publications have demonstrated that CBD is cytotoxic against breast, endometrial, glial, and blood cancers, and in all cases it appears that CBD triggers apoptosis through a cannabinoid receptor independent process. A recent publication suggests CBD causes cell death in leukemia cells via calcium dependent mitochondrial membrane disruption, leading to activation of intrinsic apoptosis. Other receptors, such as TRPV1, and pathways, such as autophagy, have been implicated in CBD‐induced cell death but the molecular details remain elusive. Because of their remarkable similarities, from a comparative oncology perspective, canine and human gliomas are of particular interest. Regardless of species, gliomas are aggressive tumors that are notoriously challenging to treat, given their resistance to multimodal treatment, thus creating a need for more effective therapeutics. We sought to characterize the mechanism of CBD‐induced cell death in both human and canine glioma cells. We show that CBD by itself is cytotoxic, anti‐proliferative, and anti‐migratory but at concentrations which may not be pharmacologically attainable. Using resazurin and the IncuCyte live cell imaging platform, we show that metabolic‐based assays artificially increase cell line sensitivity to CBD compared to the IncuCyte, suggesting that non‐cytotoxic concentrations of CBD perturb mitochondrial function. Furthermore, we show that CBD treatment results in the formation of large cellular structures whose existence are RIPK3‐dependent. After treatment with a variety of cell death inhibitors, we demonstrate that CBD‐induced cell death occurs via apoptosis; a classically necroptotic protein, RIPK3, also appears to be involved. Lastly, by combining CBD with the autophagy inhibitor hydroxychloroquine (HCQ) we show that sensitivity to CBD increases with HCQ treatment in canine cells, which suggests involvement of the autophagy pathway for mediating CBD‐induced cell death. These data demonstrate that human and canine glioma cells respond similarly to CBD, indicate a non‐canonical function of RIPK3, and support the involvement of autophagy in CBD‐induced cell death.Support or Funding InformationSupport provided by Extract Labs in Boulder, Colorado.
The Role of Sulfide in Reticulophagy through the Regulation of ATG18a by Persulfidation
Authors: Aroca Angeles , Bassham Diane C. 
Published: April 2020

Autophagy is a major catabolic process in eukaryotic cells to degrade dysfunctional or unnecessary cellular components. It has conserved functions in development, cellular homeostasis, and stress responses from yeast to plants and mammals. Autophagy is implicated in cancer, liver disease, neurodegeneration, cardiac disease, pathogen infection, among other pathological symptoms in mammals, but in plants, it is critically important in the plant life, including seedling establishment, plant development, stress resistance, metabolism and reproduction. Autophagy also contributes to intracellular homeostasis in cells by selectively degrading aggregated proteins, damaged mitochondria, ribosomes, toxic macromolecules, excess peroxisomes, and pathogens to prevent toxicity. This selective autophagy is mediated by the binding of adaptor proteins, which link a cargo targeted for degradation to the autophagosome machinery. An increasing number of targets for selective autophagy under different stress conditions have emerged in recent years, but the underlying mechanisms of their regulation are still so far unknown. Hydrogen sulfide (H2S) is an endogenously generated gaseous signaling molecule, which has been recently implicated in autophagy regulation in both plants and mammals through persulfidation of specific targets. In previous works, it has been suggested that persulfidation may be the molecular mechanism through which sulfide regulates autophagy in plant cells. ATG18a is a core autophagy component that is required for bulk autophagy and is required for reticulophagy during ER stress and RNA interference (RNAi)‐ATG18a transgenic plants showed an autophagy‐defective phenotype. Thus, persulfidation of ATG18a may regulate ER stress–induced autophagy in Arabidopsis, in a similar way as other posttranslational modifications (PTMs) regulate the ability of the ATG proteins to interact with a number of autophagic regulators. In this research, we have revealed the role of sulfide in ER stress as a negative regulator of autophagy in plants. We demonstrate that persulfidation in ATG18a is sulfide‐concentration‐dependent using a dimedone switch method with Cy5 as reporting molecule for persulfide groups. We also show that sulfide regulates ATG18a phospholipid‐binding activity by reversible persulfidation in a specific residue. Our findings demonstrate that sulfide significantly activates AtATG18a binding capacity to specific phospholipids in a reversible manner.Support or Funding InformationThis project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska‐Curie Individual Fellowship grant agreement No 834120.
Ca2+ Sensitivity of Limb Muscle Fibers in Young and Older Adults
Authors: Teigen Laura E. , Sundberg Christopher W. , Kelly Lauren J. , Hunter Sandra K. , Fitts Robert H. 
Published: April 2020

Age‐induced declines in skeletal muscle contractile function have been attributed to multiple cellular factors, including a loss of peak force (PO), decreased Ca2+ sensitivity, and reduced shortening velocity (VO). However, changes in these cellular properties with aging remain unresolved, especially in older women, and the effect of submaximal Ca2+ on contractile function is unknown. Thus, we compared contractile properties of muscle fibers from 19 young (24±3 years; 11 women) and 21 older adults (77±7 years; 7 women) under maximal and submaximal Ca2+ and assessed the abundance of three proteins thought to influence Ca2+ sensitivity. Fast fibers showed marked atrophy with aging in both men (young=8,599 μm2; old=5,404 μm2) and women (young=4,909 μm2; old=3,174 μm2) that corresponded with a decreased absolute PO in men (young=1.48 mN; old=0.92 mN) and women (young=0.85 mN; old=0.60 mN). There were no differences in fast fiber size‐specific PO, indicating the age‐related decline in force was explained by differences in fiber size. Except for fiber size and absolute PO, no age or sex differences were observed in Ca2+ sensitivity, rate of force development (ktr), or VO. Submaximal Ca2+ depressed ktr and VO, but the effects were not altered by age in either sex. Contrary to rodent studies, regulatory light chain (RLC) and myosin binding protein‐C abundance and RLC phosphorylation were unaltered by age or sex. These data suggest the age‐induced decline in whole‐muscle contractile function is primarily due to the atrophy of fast fibers and that caution is warranted when extending results from rodent studies to humans.Support or Funding InformationNational Institute on Aging grant (R01AG048262) to Robert Fitts and Sandra Hunter and an American Heart Association postdoctoral fellowship (19POST34380411) to Christopher Sundberg
What makes a good learning community?
Authors: Shaw Hannah , Richardson Kirsty 
Published: April 2020

National Higher Education satisfaction surveys have recently introduced questions related to whether students feel part of a ‘learning community’. However, there are many ways to define a ‘learning community’ and limited understanding regarding the students’ perception of this term. Questionnaires assessing student satisfaction, their perception of a learning community, what factors may affect their learning experience, the sense of belonging and perceived competence for
learning scales were distributed to first, second and final year Bioscience students (n = 1500). Through qualitative and quantitative analysis, the results will highlight the breadth of what students think a learning community is, and whether there is a difference between cohort satisfaction when studying different subjects, and why this difference may exist. It will also demonstrate whether students with a greater sense of belonging and perceived competence for learning have a higher satisfaction rating and the factors affecting these scores. The results may be used to further understand the student perspective, manage their expectations and drive curriculum change to improve their sense of belonging and satisfaction in the learning community.Ethical approval has been granted by the Cardiff School of Biosciences Ethics Review Committee
A Computational Model of Upper Thoracic High‐Frequency Spinal Cord Stimulation to Optimize Inspiratory Muscle Activation
Authors: Zander Hans , Kowalski Krzysztof E. , DiMarco Anthony F. , Lempka Scott F. 
Published: April 2020

BackgroundHigh‐frequency spinal cord stimulation (HFSCS) has been previously shown to elicit physiological activation of the diaphragm and inspiratory intercostal muscles via spinal cord pathways in canines. It was previously hypothesized that during upper thoracic HF‐SCS, the phrenic motoneuron pools are activated via spinal pathways located in the ventro‐lateral funiculus (VLF).ObjectiveThe aim of the present study was to develop a computational model of ventral HFSCS to optimize stimulation parameters and electrode configurations for activation of the inspiratory muscles.MethodsWe created a computer model of an anatomically‐accurate finite element model (FEM) of the canine spinal cord and surrounding anatomy, along with an implanted HFSCS electrode array. From this FEM, we calculated extracellular voltages generated by SCS and applied them to multicompartment cable models of axons within the VLF. Model analysis compared activation thresholds for several unique electrode designs, configurations, and electrode placements in order to optimize activation of these VLF fibers to maximize inspiratory muscle activation.ResultsFor initial model parameterization, we performed experimental measurements testing various electrode configurations and designs. We then used our computer model to evaluate several additional stimulation configurations (e.g. monopolar, bipolar) on VLF fiber selectivity. We then evaluated the effect of wider or narrow lateral lead spacing, contact spacing, and contact size. Finally, we considered several SCS waveform settings, such as rectangular waveforms and ramped waveforms, to potentially generate muscle activation more similar to natural inspiration.ConclusionsWe used our model to optimize electrode configurations, placements and novel stimulation waveforms of HFSCS to target fibers within the VLF. In particular, we found that wider lateral spacing between percutaneous electrodes better targets VLF fibers as opposed to the narrower spacing initially tested. We also show that ramped stimulation slowly recruits VLF fibers over time, which could improve naturalistic inspiratory muscle activation. In future work, we will perform experimental measurements in an animal model of HFSCS to confirm the ability of these optimized electrode designs and waveform parameters to better recreate normal inspiration.DisclosureDr. DiMarco is a founder of and has a significant financial interest in Synapse BioMedical, a manufacturer of diaphragm pacing systems and holds patents for spinal cord stimulation to restore cough and respiration (5,678,535; 5,911,218; 5,999,855; 8,751,004). Drs. DiMarco and Kowalski hold the U.S. patents for technology related to the content of this manuscript: Respiratory Muscle Activation by Spinal Cord Stimulation (8,352,036).Support or Funding InformationThis work is supported by NIH‐NINDS (R01NS064157).
Morphological and molecular changes at dendritic spines orchestrate neuronal shifts in functional identity during monocular deprivation
Authors: Zepeda Jose , Ip Jacque , Tsimring Katya , Yun Dae Hee , Ku Taeyun , Chung Kwanghun , Sur Mriganka 
Published: April 2020

Experience‐dependent plasticity refers to the brain’s ability to sculpt and remodel its circuits in an experience‐dependent manner. In the binocular visual cortex, where inputs from both eyes converge onto single neurons, the relative responsiveness of a neuron to input from one eye can shift when that eye is deprived of input. Ocular dominance plasticity (ODP) is a well‐established model for experience‐dependent plasticity, and it is triggered by monocular deprivation (MD) by suturing an eyelid. This shift is classically measured by calculating the ocular dominance index (ODI), a measure of responsiveness to either eye. The cellular and molecular mechanisms for this reorganization during ODP are not well understood. We hypothesize that morphological and molecular changes at dendritic spines (synapses) allow for functional reprogramming of neurons. To test this, we introduced a plasmid into binocular neurons via single‐cell electroporation that encodes for the calcium sensor GCaMP6s, together with a structural marker mRuby2. Using two‐photon microscopy, spines were imaged in vivo in awake mice to determine their ODIs. We then imaged at later time points during MD to measure how spine size and their responsiveness was affected. Finally, the same neurons were visualized using magnified analysis of proteome (MAP), which evenly expanded tissue by 4X to closely examine scaffolding and transmission‐related proteins at the postsynaptic density. Preliminary data suggests that a combination of extensive spine loss and potentiation of few specific spines allows for shifts in responsiveness. In addition to synaptic plasticity being important for learning and memory in adulthood, many autism spectrum disorders (ASDs) have been associated with mutations in synaptic proteins. Investigation of the molecular mechanisms behind changes in synaptic morphology are therefore important to better understand the mechanisms of learning and memory, as well as these disorders.Support or Funding InformationThis research was supported by:IMSD R25GM076321 (JZ)NIH grants EY007023 and EY028219 (MS).
Differentiation of 3T3‐L1 adipocytes with arachidonic acid increases inflammatory markers
Authors: Beck Jordan , Caldari Cristina 
Published: April 2020

Adipose tissue is responsible for insulating internal organs, storing energy for times of negative energy balance, and secreting adipokines into circulation. The major cell types found in adipose tissue include undifferentiated adipocytes (pre‐adipocytes), adipocytes, and adipose tissue macrophages macrophages (ATMs). Adipocytes and ATMs are the major sources of adipokines, adipose tissue cytokines with functions ranging from inflammatory mediators to metabolic regulators. Polyunsaturated fatty acids (PUFAs) have been shown to affect the differentiation and lipid droplet formation in 3T3‐L1 adipocytes, but few studies have examined their effects on inflammatory adipokine production from these cells. Adipocyte differentiation, which is marked by lipid droplet (triacylglycerol; TAG) accumulation, is regulated by various transcription activators, including a splice variant of the nuclear receptor PPAR□. PUFAs are major regulators of PPAR□. For example, the n‐3 PUFA EPA has been shown to have an effect on lipid droplet size through effects on lipid catabolism, as well as mediate reductions in pro‐inflammatory adipokine secretion in favor of anti‐inflammatory secretions. The objectives of this experiment were to determine the effects of n‐3 and ‐6 PUFAs on TAG lipolysis, as measured by free fatty acid (FFA) release, and inflammatory cytokine production, as measured by interleukin (IL)‐6 and macrophage inflammatory protein (MIP)‐1α production. In order to examine these effects, the 3T3‐L1 cells were differentiated in media with 100μM of PUFA treatment (α‐linoleic acid [LA], arachidonic acid [ARA], and EPA), followed by a 6 h, 1μg/mL of lipopolysaccharide (LPS) challenge. Fully differentiated 3T3‐L1 adipocytes under these treatments did not release FFA in quantifiable amounts. The LPS+ARA treatment resulted in significantly higher levels of MIP‐1□ (26.3±2.5 pg/ml) and IL‐6 (146.13±17.0 pg/ml) in conditioned media, compared to control (MIP‐1□:0.55±2.5; IL‐6:0.23±17.0), LPS (MIP‐1□:0.06±2.5; IL‐6:16.5±17.0), and LPS+LA (MIP‐1□:7.5±2.5; IL‐6:27.0±17.0). Cells treated with LPS+EPA released similar amounts of MIP‐1□ (14.9±2.5) but significantly lower amounts of IL‐6 (20.3±17.0) compared to LPS+ARA‐treated cells. These data suggest that differentiating 3T3‐L1 adipocytes in the presence of the n‐6 PUFA ARA results in increased release of LPS‐stimulated IL‐6 and MIP‐1□. These results indicate a role of this n‐6 fatty acid on adipocyte‐derived inflammation.Support or Funding InformationLaurie Bukovac Hodgson & David Hodgson Endowed Fund, as well as the Denison Summer Science Research Supply Fund