bluuebunny/crossref_metadata_2025_split huggingface dataset:
ROLE OF TRPV4 CHANNEL SIGNALING IN SHEAR STRESS RESPONSES
Authors: Aria Kevin M. 
Published: April 2020

Shear stress along the vascular intima promotes blood flow and preserves vascular wall structure, providing vital protection against progressive cardiovascular disease. Indeed, obstructive cardiovascular disease states such as atherosclerosis are associated with early shear stress disruption that leads to endothelial dysfunction and vascular remodeling. A key feature of shear stress action is a rapid and sustained increase in dynamic (spatially and temporally) Ca2+ signals within the endothelium, which promotes vasodilation and opposes inflammation. Although specific mechanisms remain unclear, recent studies have implicated mechanosensitive TRPV4 cation channels in shear stress mediated Ca2+ entry. We hypothesize that shear stress‐induced endothelial Ca2+ signals arise from graded recruitment of TRPV4 Ca2+ transients. We performed Ca2+ imaging studies on arteries isolated from wild type and genetically altered TRPV4 knockout mice. Carotid arteries were isolated, opened, and mounted in specialized flow chambers. The chambers were connected to a peristaltic pump and placed on the stage of a microscope adapted for high‐speed confocal imaging (488 nm ex, 510 nm emission; 8 frames/s). Endothelial Ca2+ dynamics were recorded at increasing flow rates (shear stress 0, 12, 52, 75, and 102 dynes/cm2). Image analysis was performed using ImageJ and custom software (LC_Pro) designed to discern distinct profiles of signal frequency, amplitude, duration and spatial spread. Artery segments were also subjected to immunostaining to assess relative expression and distribution of TRPV4 channels. We found that the wild type and TRPV4 knockouts both responded to shear stress. The TRPV4 knockout exhibited a reduced Ca2+ event frequency and shorter event durations compared to wild type controls in response to physiologic elevations in shear stress. Future experiments will focus on expounding upon the flow response, particularly the importance of TRPV4 channels in the time‐course of Ca2+ signal patterning changes under chronic low flow conditions.Support or Funding InformationSponsored by Mark Taylor and David Weber, Ph.D., Department of Physiology/Cell Biology, University of South Alabama College of Medicine, Mobile, AL. Summer Medical Student Research Program
Dysbiosis in hypertension modulates kidney function through TLR4‐mediated gut barrier disruption
Authors: Majumder Suravi , Pushpakumar Sathnur , Sen Utpal 
Published: April 2020

Inflammation is a major mediator in the development and progression of hypertension‐induced chronic kidney disease (CKD). Recent studies demonstrated that altered gut microbiota contributes to blood pressure (BP) dysregulation and kidney dysfunction in hypertension. Both animal and clinical studies in hypertension revealed decreased gut microbial richness and diversity. Further, a plethora of evidence suggests that gut barrier impairment allows bacteria genes and their products to enter circulation and affect physiological function in different organs. Although the relationship between Angiotensin II‐induced (Ang II) hypertension and TLR4‐mediated inflammatory response has been established, the contribution of TLR4 in the gut‐kidney axis to modulate kidney function is unclear. We therefore sought to determine the possible link between TLR4 and the gut‐kidney axis in hypertension‐induced renal injury and dysfunction. Mice with normal TLR4 (C3H/HeOuJ, HeOuJ) and mice lacking functional TLR4 (C3H/HeJ, HeJ) were treated without or with Ang‐II (1000 ng/kg b.w.) for 4 weeks. Increased BP and reduced renal function (GFR) were recorded in HeOuJ mice following Ang II treatment. HeJ mice were partially resistant to Ang II‐induced hypertension. 16S rRNA sequencing analysis of gut microbiome revealed differentially altered microbial richness and diversity in HeOuJ mice compared to HeJ mice during hypertension. Further, HeOuJ mice showed gut barrier disruption to Ang II as indicated by decreased tight junction proteins (ZO‐1, Occludin, Claudin‐1) and increased gut permeability (FITC dextran leakage into the bloodstream) compared to HeJ mice. Increased bacterial component translocation was observed (16S rRNA) in hypertensive HeOuJ kidney compared to other groups. In response to Ang‐II, gut and kidney inflammation (IL1b, IL6, TNFa) was markedly increased in HeOuJ mice but blunted in HeJ mice. Taken together, our data demonstrates that gut dysbiosis during hypertension triggers TLR4 activation and gut barrier disruption leading to renal inflammation and dysfunction and mice lacking normal TLR4 are protected from dysbiosis/TLR4 mediated renal injury.Support or Funding InformationDK116591, DK104653, 15SDG25840013
CTRP3 and Alcoholic Liver Disease in Female Mice
Authors: Root Callie Leah 
Published: April 2020

IntroductionC1q TNF Related Protein 3 (CTRP3), is a cytokine that is primarily secreted from adipose tissue, also known as an adipokine. Our previous research has shown that CTRP3 prevents alcoholic fatty liver disease (ALD) in male mice. However, even when accounting for confounding factors such as absolute and relative alcohol intake females are more sensitive to the effects of ethanol compared to male mice. Therefore, the goal of this project was to determine whether CTRP3 prevented ALD in female mice or determine whether the beneficial effects of CTRP3 are sex specific.MethodsFemale wild type (WT) and CTRP3 transgenic over expressing (Tg) mice were fed an ethanol containing liquid diet (5% v/v) for 6 weeks. Daily weight and food intake measurements were taken and external heat‐pads were placed under a portion of the cage to facilite thermoregulation. Hepatic steatosis was determined by total triglyceride quantification and lipid droplet quantitation in liver sections. Data were analyzed by repeated measures ANOVA, t‐test, or Log‐rank (Mantel‐Cox) test as appropriate.ResultsThere was no difference between WT and Tg mice in food intake or body weight. There was no difference in survival between WT and Tg mice, however, Tg mice trended towards a reduced rate of survival compared with WT mice (78% in WT versus 44% in Tg, p=0.13). Stereological analysis indicated no difference in the percent of lipid liver volume between the two groups (WT 7.2±3.6 vs Tg 5.1±4.1%). This finding was consistent with no difference in total hepatic triglyceride accumulation observed between WT and Tg mice (12.7±4.4 vs. 13.1±6.8 mg triglycerides/gram liver protein).ConclusionCombined these data indicate that unlike previous studies with male mice, CTRP3 is not protective against alcohol‐induced hepatic steatosis. Combined, these data indicate that the adipokines such as CTRP3 contribute to physiology in a sex‐specific manner.
Comparison of academic performance in undergraduate Anatomy and Physiology using in‐person versus asynchronous on‐line laboratory instruction
Authors: Peterson Jonathan M. , Brown Patrick 
Published: April 2020

OBJECTIVETo compare the effectiveness of asynchronous on‐line laboratory instruction with in‐person instruction on learning in undergraduate Anatomy and Physiology.METHODSA retrospective analysis was conducted on student academic performance on the first semester of a 2‐semester Anatomy and Physiology course. All students were enrolled in an asynchronous on‐line Anatomy and Physiology lecture course and had the option of enrolling in either an in‐person or asynchronous on‐line laboratory. Assessment of learning for all students was obtained via course management software. Specific assessments included 3 lecture examinations, 2 laboratory examinations, and 12 specific content quizzes for lecture and laboratory respectively (24 quizzes total). All examinations were proctored, whereas students were not proctored for quizzes and were encouraged to use their textbooks and notes. Student engagement was assessed based on number of independent course log‐ins, number of completed tasks, and total time spent.RESULTSOverall the students who enrolled in the in‐person laboratory instruction had mean examination scores ca. 10% higher than the on‐line laboratory students that was greatly dependent on topic area. Specifically, there was no difference between the two groups in the first lecture exam (regional anatomy, cellular anatomy, and histology), with a 9% difference in the second exam (musculoskeletal system), and a 13% difference in the third lecture exam (Nervous system). There was no difference between the two sets of students in the measures of student engagement or in the lecture quiz scores. There was a 22% decrease in the mean laboratory quiz grade for students enrolled in the on‐line laboratory. There was a 14% and 22% difference in the mean scores for the 2 laboratory exams. Further, the reduction in mean laboratory examination score was still significant when normalized to the student’s individual mean lecture examination score.CONCLUSIONSThe use of asynchronous on‐line laboratory instead of in‐person laboratory instruction can significantly negatively impact student academic performance.Support or Funding InformationNIDDK R15DK114740
Sympathetic Neurotransmitters Decrease Muscle Spindle Afferent Response to Muscle Stretch
Authors: Salazar Alexandra , Harnisch Arthur , Valdespino Steven , Wilkinson Katherine A. 
Published: April 2020

Proprioception is the ability to sense body position and motion in space. The primary proprioceptors are the Group Ia and II muscle spindle afferents that innervate the muscle spindle and comprise the sensory arm of the muscle stretch reflex. In‐vivo animal studies have shown that increased sympathetic outflow decreases dynamic and static stretch sensitivity of muscle spindle afferents. However, the direct effect of sympathetic neurotransmitters on muscle spindle afferent stretch sensitivity is not well understood. We hypothesized that the addition of sympathetic neurotransmitters would cause a decrease in responsiveness of muscle spindle afferents via direct action in the muscle spindle. To test this hypothesis, we used an in‐vitro mouse muscle nerve preparation to record muscle spindle afferent firing rates during stretch. The muscle was stretched once every three minutes to 5% resting length for 4 s. Muscle spindle afferent firing rates were determined during the plateau phase of stretch and compared before and after drug addition. Instantaneous firing frequency during a static muscle stretch was measured at different time intervals: beginning of stretch (0.5 seconds into the hold phase or Initial Static Time (IST)) and end of stretch (3.5 seconds into the hold phase or Final Static Time (FST)). All values are expressed as a percentage of the average of 6 pre‐drug baseline responses (BL) and compared to no drug control mice stretched for the equivalent time. Exposure to 100μM norepinephrine (n=6, IST=54.18% BL, FST=37.70% BL) significantly decreased the response to stretch as compared to no drug control animals (n=12, IST=90.82% BL, FST=91.50% BL; p<0.05 One‐way ANOVA w Tukey’s post‐hoc to control). The addition of epinephrine decreased muscle spindle afferent firing, however only significantly at the lower dose of 30μM (n=6, IST=76.90% BL, FST=73.20% BL; p<0.05). The α1 adrenergic receptor agonist, phenylephrine, was used to test the hypothesis that the decrease seen following norepinephrine was due to binding at the α1 adrenergic receptor. No statistically significant decrease was found following phenylephrine administration, however, the sample size used was small (n=3, IST=96.70% BL, FST=96.98% BL). These results show direct effects of sympathetic neurotransmitters on muscle spindle afferent stretch sensitivity and support the hypothesis that sympathetic innervation of the muscle spindle plays an important role in modulating stretch responsiveness. Future studies will use optogenetic techniques to stimulate the sympathetic neurons to determine whether physiologically relevant release of sympathetic neurotransmitters controls muscle spindle afferent sensitivity.Support or Funding InformationThis work was supported by NIH SC3 GM127195 (KAW) and NIH R25 GM071381 (AS and SV).
Effect of Prenatal Glucocorticoid Exposure on Circadian Rhythm Gene Expression in the Brains of Adult Rat Offspring
Authors: Murray Alyssa , Khurana Sandhya , Lalonde Christine , Tharmalingam Sujeenthar , Nguyen Phong , Tai T.C. 
Published: April 2020

Circadian clocks developed in organisms as a way of estimating the time of day. In mammals, the circadian clock is based on molecular oscillators that operate through transcriptional‐translational feedback loops. While normal circadian signaling relies on a ‘master clock’, in the suprachiasmatic nucleus (SCN), to synchronize peripheral oscillators to environmental light, glucocorticoid receptor (GR) signaling has the ability to reset the phase of peripheral clocks. GR is responsive to cortisol and is central to the regulation of genes involved in stress response, immune regulation and metabolism. Phase shifts allow peripheral clocks to become uncoupled from the master clock. The SCN does not express GR and this ensures it stays tied to the light‐dark cycle. It has been shown that maternal exposure to glucocorticoids (GCs) can lead to modification of hypothalamic‐pituitary‐adrenal (HPA) function and impact stress‐related behaviours via GR activation. While exploring the effects of prenatal GC exposure on rat offspring, our lab previously demonstrated altered circadian rhythm signaling in the adrenal glands using whole transcriptomic profiling. Pregnant WKY rats were given daily subcutaneous injections of 0.1 mg/kg/day DEX (Dexamethasone, a synthetic GC), or a saline vehicle throughout the third semester, and offspring sacrificed at 18 weeks of age for tissue collection. Brain regions were isolated through a micropunch technique and RNA extracted. Results from the current study show that prenatal GC exposure affects circadian rhythm gene expression in the molecular oscillators of the amygdala, hippocampus, prefrontal cortex, paraventricular nucleus as well as the main oscillator in the SCN. Transcripts of circadian rhythm genes in these tissues were measured through RT‐qPCR and demonstrated both sex and tissue specific alteration in expression of circadian genes including Bmal1, Clock, Npas2, as well as the Per and Cry genes. This widespread dysregulation of the circadian rhythm system points to a mechanism whereby the dysfunction seen previously in the adrenal gland arises from a programmed dysregulation of the entire circadian system beginning at the master clock in the SCN.Support or Funding InformationSupported by grants from CIHR and NOSMFA Research Development Fund.
Structural and functional analysis of the role of the chaperonin CCT in mTOR complex assembly
Authors: Willardson Barry M. , Cuellar Jorge , Ludlam Grant , Tensmeyer Nicole C. , Aoba Takuma , Dhavale Madhura , Santiago César , Bueno-Carrasco Teresa , Mann Michael J. , Plimpton Rebecca L. , Makaju Aman , Franklin Sarah 
Published: April 2020

The mechanistic target of rapamycin (mTOR) kinase forms two multi‐protein signaling complexes, mTORC1 and mTORC2, which are master regulators of cell growth, metabolism, survival and autophagy. Two of the subunits of these complexes are mLST8 and Raptor, β‐propeller proteins that stabilize the mTOR kinase and recruit substrates, respectively. Here we report that the eukaryotic chaperonin CCT plays a key role in mTORC assembly and signaling by folding both mLST8 and Raptor. A high resolution (4.0 Å) cryo‐EM structure of the human mLST8‐CCT intermediate isolated directly from cells shows mLST8 in a near‐native state bound to CCT deep within the folding chamber between the two CCT rings, and interacting mainly with the disordered N‐ and C‐termini of specific CCT subunits of both rings. These findings describe a unique function of CCT in mTORC assembly and a distinct binding site in CCT for mLST8, far from those found for similar β‐propeller proteins.Support or Funding InformationThis research was supported by the grant BFU2016‐75984 (AEI/FEDER, EU) and the Madrid Regional Government (grant S2013/MIT2807) to JMV as well as the US National Institutes of Health grant EY012287 to BMW and fellowships from the Brigham Young University Simmons Center for Cancer Research to WGL, NCT, TA and MD.
Endothelial Senescence in Regenerative Lung Growth after Pneumonectomy
Authors: Mammoto Akiko , Hendee Kathryn , Mammoto Tadanori 
Published: April 2020

Impairment of lung regeneration and repair in aging animals contributes to the pathogenesis of aging‐associated diseases, including chronic obstructive pulmonary disease (COPD). Angiogenesis – the formation of new blood capillaries ‐ plays a key role in organ regeneration. We have reported that inhibition of angiogenesis attenuates lung growth after unilateral pneumonectomy (PNX) and that post‐PNX regenerative lung growth is inhibited in aged mice. While accumulation of senescent cells in aged adults is linked to the age‐related decline in regenerative ability, senescent cells also play important roles in injury repair and tissue remodeling. Here we investigate the role of endothelial cell (EC) senescence in regenerative lung growth after PNX in young vs. aged mice. The levels of the senescence marker, p16INK4A and a major angiogenic factor, angiopoietin2 (Ang2) transiently increase in ECs isolated from 2‐months (2M) old post‐PNX mouse lungs compared to those from sham‐operated control mice and decrease at the later stage. The baseline levels of p16INK4A are high in 24M old mouse lung ECs but post‐PNX transient induction of p16INK4A and Ang2 is inhibited in 24M old mouse lung ECs. Depletion of senescent cells from 2M old p16‐3MR mice by treating with ganciclovir suppresses post‐PNX lung growth. When ECs isolated from 2M old post‐PNX mouse lungs are mixed in the gel and implanted on the mouse lungs, vascular network formation is stimulated in the gel, while these effects are inhibited in the gel mixed with 24M old post‐PNX mouse lung ECs. These results suggest that post‐PNX transient induction of EC senescence is required for vascular morphogenesis after PNX. Deregulation of this mechanism may contribute to age‐dependent inhibition of regenerative lung growth. Understanding this mechanism will lead to the development of efficient strategy for aging‐associated lung diseases.Support or Funding InformationNIH R21AG054830, NIH R21AG062893, NIH R01HL142578, AHA 18TPA34170129
Distinct Bacterial Populations Colonizing Plastic Debris in Coastal Waters of Southern California
Authors: Leask Allison , Barral Ana Maria , Simmons Rachel E. 
Published: April 2020

Microbes that attach to plastic form the so‐called plastisphere, a unique ecosystem of microbes that may impact the ocean and its inhabitants. While the microbial populations present on microplastics, tiny fragments resulting of physical and chemical breakdown of plastic debris, have been described in multiple studies, much less is known about the initial stages of bacterial colonization. This project is part of a study to evaluate the presence and diversity of bacteria colonizing floating plastic in coastal waters using metagenomic DNA sequencing and live culture experiments. We particularly focus on colonies isolated from two different sampling locations using different culture media and some of their physiological characteristics.The objective of this research is to identify bacteria colonizing ocean plastic using 16S rDNA barcoding from cultures isolated from exposed plastic. In addition, some physiological characteristics of the bacteria, such as antibiotic production and plastic degradation, is explored in parallel.Three types of floating plastic (High and low density polyethylene and polypropylene) were exposed to beach water at Doheny State Beach (Dana Point, CA) and near the Scripps Institution of Oceanography pier (La Jolla, CA). Samples were collected at different time points, in a range up to 2 months. Colonies were grown on Salt Water Agar (SWA) or Marine Agar, as well as ChromAgar Vibrio (CAV) media and characterized using 16S amplicon sequencing. Fourier Transform Infrared Spectroscopy (FTIR) was used to analyze the breakdown of plastic over time and scanning electron microscopy (SEM) to visualize the biofilms attached to plastic on day 40.No clear pattern of colonization was observed over a month period. With longer incubation times, an increase in unknown/uncultured bacteria species was noted. Antibiotic production was observed in several colonies of the genus Phaeobacter. Signs of chemical breakdown were observed as early as after 21 days of incubation.Support or Funding InformationSupported by NU internal grants as well as the NSF HSI’s new to NSF award #1832545
Halophile Inoculation Significantly Improves Growth of Alfalfa Under Saline Conditions
Authors: Miller Ashley , Knowles Alisa , Nielsen Brent , Hill Jonathon 
Published: April 2020

Saline soils limit crop production, and salinity is increasing in farmland in many parts of the world. A halophilic bacterial species has been isolated from salt‐tolerant plants, and when used as an inoculum stimulates growth of alfalfa in salty soil. The hypothesis is that the microbial inoculant induces gene expression changes in the plant, resulting in the increased growth of the plant in salt. To test this, RNA was isolated from inoculated and uninoculated alfalfa plants grown under saline conditions, with additional controls in the absence of salt. RNAseq analysis of these four treatments led to identification of differentially expressed genes (DEG). Several of these DEGs are being examined in more detail using quantitative reverse‐transcriptase PCR. This will lead to the identification of major plant gene expression changes induced by the bacterial inoculum under saline conditions.Support or Funding InformationOur work is being funded by a grant from the Roger and Victoria Sant Educational Endowment for a Sustainable Environment, a John Topham and Susan Redd Butler BYU Faculty Research Award (The Charles Redd Center for Western Studies), and the Department of Microbiology and Molecular Biology, Brigham Young University.
The Role of Ceramide Synthases Response to the Heavy Metal Cadmium Chloride
Authors: Peck Margaret Eleanor , Staab Trisha , Chan Jason , Moats Alicen G. , Kalil Azia 
Published: April 2020

Cadmium is an extremely toxic heavy metal that is hazardous to human health. In the United States, the primary source of cadmium exposure is in the food supply. Ingestion results in a buildup of cadmium in the body, specifically in the kidneys, which can lead to organ damage and cancer. This toxin has been known to induce stress in organisms by causing an accumulation of reactive oxidative species (ROS). To counter stress, cells respond with a variety of signaling pathways. We are interested in studying the sphingolipid pathway, which is known to mediate stress responses, but its role in defending against cadmium toxicity is unclear. We hypothesized that ceramide synthase, a sphingolipid metabolism enzyme, is required for survival to cadmium stress and decreased accumulation of ROS in animals. To test this, we utilized the model organism Caenorhabditis elegans. Ceramide synthase converts sphingosine to ceramide in the cells. We examined animals with mutations in ceramide synthase (hyl‐2 mutants) by treating worms to acute and chronic cadmium exposure and examining changes in survival, reproduction, and locomotion. We present data showing that cadmium does not affect animal reproduction, but it does affect survival upon exposure. Cadmium exposure resulted in decreased survival, however, and this result was less prominent in organisms possessing hyl‐2/ceramide synthase. We also found that the hyl‐2 gene is vital for oxidative stress response mechanisms. In addition, we present data on the effects of cadmium exposure on gene expression of sphingolipid metabolism enzymes using qPCR. These results are important because stress plays a role in aging, and if we better understand how stress is regulated via sphingolipids, it could become a potential pharmaceutical target to slow the degradative aging process.Support or Funding InformationNIH‐ 2R15AG052933