bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of eating a high fat diet on sensitivity of female rats to ethanol
Authors: Galindo Kayla I. , Castillon Alex Serna , Serafine Katherine M. 
Published: April 2020

Eating a diet that is high in fat or sugar can impact dopaminergic systems, the same pathways targeted by drugs of abuse. Rats eating a high fat laboratory chow are more sensitive to the behavioral effects of drugs of abuse, including cocaine and methamphetamine. However, it is not known if eating a high fat diet also enhances sensitivity of rats to alcohol. To address this gap in knowledge two experiments were conducted. In Experiment 1, 24 female Sprague‐Dawley rats eating either standard (18% kcal from fat) or high fat (60% kcal from fat) chow for 5 weeks were trained to drink ethanol solution. Training consisted of a daily 4‐hour session for 28 days. Following training, during the test phase, two bottles were presented (one containing 8% w/v ethanol and one containing water) while animals had continuous access to food. In Experiment 2, the development of locomotor sensitization to once weekly cumulative doses of 15% ethanol (0.5–2.0 g/kg; i.p.) was studied in 16 female Sprague Dawley rats eating the same types of chow used in Experiment 1 (high fat or standard). In Experiment 1, rats eating high fat chow consumed more milliliters of ethanol on average daily than rats eating standard chow; however, when accounting for body weight, this difference was no longer apparent. Experiment 2 is ongoing; however, based on previous work with psychomotor stimulants, it is anticipated that rats eating high fat chow will be more sensitive to ethanol‐induced locomotor sensitization. These results provide additional information related to the growing obesity epidemic and its potential relationship substance use disorder. Future directions will investigate the impact of diet on sensitivity of male rats to ethanol, in order to examine potential sex differences.Support or Funding InformationDisclosures: The authors have no conflicts to declare. The present study was supported by the National Institute on Drug Abuse (R25‐DA033613).
Neuropeptide Y Inputs to Neurons in the Dorsomedial Hypothalamus Tonically Inhibit Brown Adipose Tissue (BAT) Sympathetic Nerve Activity (SNA) via NPY Y1 Receptors
Authors: Madden Christopher J. 
Published: April 2020

Hypothalamic Neuropeptide Y (NPY) has been implicated in metabolic homeostasis. For example, NPY acts in the paraventricular nucleus of the hypothalamus to decrease BAT SNA. NPY neurons within the dorsomedial hypothalamus (DMH) have also been implicated in energy balance, however the role of NPY inputs to BAT regulatory neurons in the DMH has not been assessed. The present study tested the hypothesis that neurons in the DMH receive a NPY‐containing input that contributes to the regulation of BAT SNA via activation of NPY Y1 receptors. First, administration of a retrograde tracer (cholera toxin B) into the raphe pallidus area (RPa) and immunohistochemistry for NPY demonstrated that CtB‐labeled (RPa‐projecting) DMH neurons receive close appositions from NPY‐positive fibers. In addition, bilateral nanoninjections of the NPY Y1 receptor antagonist BIBO3304 (2mM, 60nl) into the DMH increased BAT SNA +424±110% baseline, TBAT (+2.2±0.5 °C) and expired CO2 (+1.2±0.1%). In conclusion, NPY inputs to neurons in the DMH tonically inhibit BAT SNA and BAT thermogenesis via activation of NPY Y1 receptors.Support or Funding InformationNIH DK112198
What Is the Mechanism Underlying Pressure‐induced Chronotropy in Collecting Lymphatic Vessels?
Authors: Davis Michael J. , Li Min , Jaggar Jonathan H. , Zawieja Scott C. 
Published: April 2020

The rhythmic contractions of lymphatic smooth muscle (LSM) cells enable lymph propulsion against adverse pressure gradients. These contractions are initiated by LSM action potentials (APs), generated by an ionic pacemaker, whose rate is sensitive to the transmural pressure difference. We recently showed that SM‐specific deletion of the Ca2+‐activated Cl− channel, anoctamin1 (Ano1), reduced the basal AP firing rate of mouse inguinal‐axillary lymphatic (IALs) vessels to ~25% of normal and abrogated pressure‐induced chronotopy. However, IALs are efferent vessels that show only a modest (2‐fold) increase in contraction frequency over the presumed physiological pressure range 0.5 – 8 cmH2O. In contrast, popliteal afferent lymphatics (PLs) exhibit an 8‐fold increase in chronotropy from 0.5 – 5 cmH2O and SM‐specific deletion of Ano1 attenuates but does not abolish their pressure‐induced chronotropy. Here we asked: 1) what other ionic mechanisms participate in pressure‐induced chronotropy of PLs? 2) what accounts for the residual, pressure‐independent pacemaking in IALs and PLs after Ano1 deletion?To address these questions we measured the frequency‐pressure relationship (F‐P) of cannulated, pressurized PLs from control mice and mice deficient in key mechanosensitive and second‐messenger‐gated ion channels implicated in arterial pressure sensing. SM‐specific deletion of the mechanosensitive cation channel Piezo1 had no significant effect on F‐P. Global deletion of the osmosensitive cation channel TRPV4, or the DAG‐gated cation channels TRPC3 or TRPC6, or both, had no significant effect on F‐P. TRPM4−/− mice were not available, but the selective TRPM4 inhibitors, CBA and NBA, had minimal effects on F‐P. SM‐specific deletion of the cation channel TRPP1 (Pkd2) had no significant effect on F‐P. Deletion of T‐type Ca2+ channels Cav3.1 and/or Cav3.2 (previously implicated in lymphatic pacemaking), had no significant effect on F‐P. However, SM‐specific deletion of IP3R1, the only IP3R isoform expressed in mouse LSM, produced a phenotype similar to Ano1 deletion: a reduction in basal frequency and blunting of the F‐P relationship, suggesting a pressure‐induced IP3 generation downstream from mechanosensitive G‐protein(s). We then tested the prominent arterial SM mechanosensitive GPCR, AT1R. The inverse agonist losartan had no effect on F‐P nor did global knock out of AT1bR, the only isoform expressed in mouse LSM. In conclusion, our results point to a GPCR mechanosensing mechanism, independent of AT1R, that generates IP3 in a pressure‐sensitive manner to activate Ano1 and regulate the cycling rate of the ionic pacemaker in lymphatic smooth muscle.Support or Funding InformationNIH‐HL‐122578
Breathing and Respiratory Muscle Function in Senescent Wild‐type and Ts65Dn Male Mice
Authors: Sheekh-Nuur Muno M. , Rodd Maeghan C. , Receno Candace N. , Burns David P. , DeRuisseau Keith C. , Cunningham Caitlin M. , DeRuisseau Lara R. 
Published: April 2020

Down Syndrome (DS) results from trisomy 21 and is the most common cause of mental retardation in the US. People with DS display reduced muscle tone and cardiorespiratory complications that may contribute to breathing disturbances. Ts65Dn (Ts) mice, a model of DS, exhibit increased apnea frequency at 3 months of age (7±9 vs. 36±28; wild‐type (WT) vs. Ts) that persists at 6 (19± 7 vs. 77±58) and 12 months (5±6 vs. 64±77; p<0.001 for age, strain, and age by strain). People with DS have increased life expectancy and it is unknown how breathing changes across the lifespan in this population. We tested the hypothesis that ~20‐month‐old Ts mice would have altered ventilation compared to age‐matched WT mice. To test this hypothesis, unrestrained barometric plethysmography was used to quantify breathing frequency (breaths/min), tidal volume (VT; mL), VT/inspiratory time (VT/Ti; mL/sec), minute ventilation (VE; mL/min) and ventilatory equivalent for CO2 (VE/VCO2) in 18 to 22‐month‐old male WT (n=12) and Ts (n=13) mice. Data Sciences International Ponemah software was used to analyze flow tracings during exposure to air (20.93% O2, balanced N2). Data are expressed as mean±S.D., WT vs. Ts. A main effect of strain was uncovered using MANOVA (p=0.033). Breathing frequency (171±33 vs. 136±41 breaths/min; p=0.025) and VE (74.6±25.7 vs. 50.3±15.5 mL/min; p=0.010) approached the a priori cutoff (Bonferroni correction, p<0.01). VT (0.439±0.112 vs. 0.377±0.075 mL/breath; p=0.123) and the ratio of VE/VCO2 (45.5 ±22.0 vs. 42.4±19.8; p=0.715) were not different. VT/Ti (3.65±1.03 vs. 2.49±0.759 mL/sec; p=0.004) was reduced in Ts vs. WT, which suggests Ts mice have a reduced ventilatory drive. Since people with DS demonstrate evidence of muscle weakness, we examined diaphragm (DIA) and sternohyoid (SH; representative pharyngeal dilator) muscle function in WT (DIA n=10, SH n=9) and Ts (DIA n=7, SH n=7) mice. Twitch (2.2±1.1 vs 2.3±1.0 N/cm2; p=0.835) and tetanic (11.2±7.3 vs. 11.6±4.8 N/cm2; p=0.900) force, and the force frequency‐relationship (p=.766) for SH muscle were equivalent between groups. Similarly, no differences were observed for DIA twitch (6.0±2.7 vs. 5.2±2.1 N/cm2; p=0.438) and tetanic (20.7±6.0 vs. 19.9±2.8 N/cm2; p=0.758) force, or the force‐frequency relationship (p=0.339). Diaphragm function was preserved in aged Ts mice which is in line with similar VT between groups. These data reveal the increased propensity for apnea in Ts mice is independent of upper airway muscle weakness and may alternatively be of neural origin. Current studies are examining motor control of the upper airway in Ts mice.Support or Funding InformationThis work was funded by 1R15HD076379 (LRD), 3R15HD076379 (LRD). Additional support was granted by the Le Moyne College McDevitt Center Undergraduate Research Fellowship in Natural Science (MS‐N, MR), and the Le Moyne College Biological Sciences Department.
CHARACTERIZING THE LEPTIN‐INDUCED ACTIVATION OF PRE‐SYMPATHETIC CARDIOVASCULAR AND METABOLIC‐RELATED HYPOTHALAMIC NEURONS IN MICE
Authors: Hillard Kynlee Jo , Lindsey Stacia Jayce , Fraley Stephanie Kate , Peterson Jonathan Micheal , Zahner Matthew Ralph 
Published: April 2020

Obesity has risen 75% in the United States since 1980 and an estimated 80 million American adults are considered obese. Obesity activates the sympathetic nervous system and is associated with neurogenic hypertension. Leptin is an obesity‐related neuropeptide released from fat cells which reduces appetite and increases metabolism. Leptin activates metabolic and cardiovascular responsive pre‐sympathetic neurons within the hypothalamus. Although leptin increases metabolism and curbs appetite, it is also reported to increase blood pressure and heart rate. Considering that the common goal of obesity treatments is to diminish the cardiovascular‐related co‐morbidities increases in blood pressure and heart rate are unacceptable side effects for any potential treatment. Thus, a better understanding of the role hypothalamic sites involved in obesity‐related hypertension is necessary for the development of successful treatments. In this study, we tested the hypothesis that leptin activates pre‐sympathetic hypothalamic neurons that control either metabolic (raphe pallidus‐projecting) or cardiovascular activity (RVLM, rostroventrolateral medulla‐projecting). First, to identify leptin receptor expressing neurons we created a line of transgenic reporter mice using the cre‐lox recombination system to express tdTomato under the control of the leptin (ObRb) receptor gene. Then, to determine if exogenous leptin treatment activates pre‐sympathetic metabolic or cardiovascular‐related hypothalamic neurons we performed neuroanatomical tracer studies in these mice. Metabolically‐related neurons were identified by microinjection (50 nl) of green FluoSpheres™ (505/515) into the raphe nucleus and cardiovascular‐related neurons were identified by microinjection (50 nl) of magenta FluoSpheres™ (660/680) into the rostroventrolateral medulla (RVLM). We then treated these mice with an acute dose of leptin (25 μg/mouse IP) and then performed fluorescence immunohistochemical labelling to identify leptin‐induced neuronal activation of cFos, a marker of neuronal activation. Using this approach we identified both a population of RVLM‐projecting and a population of raphe‐projecting leptin expressing neurons. These data provide additional information to suggest that the leptin‐induced increases in cardiovascular and metabolic activity is mediated in part by activation of pre‐sympathetic hypothalamic neurons.Support or Funding InformationETSU RDC 19‐030 (Zahner MR) NHLBI R15 HL145645‐01 (Zahner MR)
Nuclear Phosphoinositide 3‐kinase delta (PIK3CD) Increases with Conditional Deletion of Hepatocellular Integrin Linked Kinase
Authors: Martucci Nicole Jenna , Cotner Mary-Clare , Bhushan Bharat , Mars Wendy M. , Michalopoulos George K. 
Published: April 2020

IntroductionThe extracellular matrix (ECM) is important for survival, differentiation, and normal functioning of cells within the liver; integrins are key signaling receptors in this process. Previous data from our lab has shown that with hepatocyte specific knockout of integrin linked kinase (ILK KO), there is hepatocyte proliferation, increased matrix deposition, unorganized biliary cell/ductal proliferation, and possible transdifferentiation of hepatocytes to cholangiocytes; this led us to investigate the signaling pathways downstream of hILK KO that might be responsible for the observed phenotype, and we uncovered a potential central role for Phosphoinositide 3‐kinase (PI3K) delta (PIK3CD), a variant of PI3K that is considered to be leukocyte specific.MethodsMice with germ‐line loss of hepatocellular ILK were generated by crossing double floxed ILK mice (ILKfl/fl) with mice expressing cre recombinase under an afp enhancer‐albumin promoter (Cre+/−) to obtain ILKfl/fl:Cre+/− (ILK KO) and ILKfl/fl:Cre−/− (WT). Data array analyses were performed on livers from 7‐ and 14‐week old chronic ILK KO and WT mice. RNAs of interest were identified and then further examined by western blot analyses, immunohistochemical staining, and induction of acute loss of ILK using AAV8 cre in ILKfl/fl mice.ResultsExamination of the 7‐week RNA array analysis suggested a central role for PIK3CD in the observed hILK phenotype. Unexpectedly, using immunohistochemistry we detected prominent staining of PIK3CD protein in ILK KO hepatocytes. The presence of PIK3CD was verified in cultures of wild type hepatocytes where inhibition of PIK3CD resulted in a decrease in both pAKT (a downstream target) and Cyclin D1. Western blot analyses of whole livers also uncovered a size variant that is only observed in isolated nuclei. Additionally, at 7 days after the acute removal of ILK, we can observe staining for the cholangiocyte specific marker, CK19, in hepatocytes as well as strong PIK3CD staining in regions with spontaneous duct formation.ConclusionOur RNA and protein data from ILK KO mice have 1) revealed PIK3CD, a leukocyte specific protein, to be hepatocellular 2) shown that a size variant of PIK3CD exists in the nuclei of hepatocytes and 3) uncovered a potential relationship between PIK3CD in hepatocytes and their transdifferentiation to biliary cells. Currently, we are using an in vitro model of trans‐differentiation in an attempt to further explore these preliminary findings.Support or Funding InformationCATER NIH T32 EB001026.
Targeting estrogen non‐genomic signaling in a three‐dimensional (3D) in vitro model of inflammatory breast cancer
Authors: Negrón Dalissa , Peterson Esther 
Published: April 2020

Inflammatory Breast Cancer (IBC) is the most aggressive form of breast cancer with a low overall 5‐year survival rate of ~30–60%. To this date the molecular signature associated with IBC is not completely characterized, which lead to a lack of effective targeted therapeutics, especially for those patients that account for the 20–40% of triple‐negative (TNBC) IBC cases. Several studies established that molecular signature of IBC shows important differences from the other breast cancer subtypes, such as overexpression of ErbB receptors, RhoC GTPase and Cox‐2, E‐cadherin aberrant expression, and loss of WISP3 among others. However, these molecular alterations do not explain completely the aggressive and rapid IBC phenotype. Recently, several studies have shown that estrogen can exert non‐genomic effects in triple‐negative IBC and other TNBCs, mediated by the expression of alternate estrogen receptors, including ERα36 and GPR30. Estrogen non‐genomic signaling refers to the rapid action of these alternate estrogen receptors that upon estrogen binding activates protein‐kinase cascades in the cytoplasm. We hypothesize that estrogen can elicit a specific non‐genomic signaling cascade that promotes the acquisition of aggressive oncogenic phenotypes in IBC and that targeting this pathway can be an effective anticancer therapy for IBC. To test this hypothesis, we are going to use pharmacological inhibition of ERα36 and GPR30 using antagonists against these receptors alone or in combination with EGFR inhibition. In parallel, we are going to use siRNA to down‐regulate the expression of these receptors. The first approach is to determine if inhibiting estrogen nongenomic signaling by targeting the alternate receptors affect cell proliferation in a 3D colony formation assay using Matrigel. Preliminary observations showed that cells treated with E2 develop larger colonies (increase proliferation) when compared to vehicle control. Inhibiting GPR30 alone have a slight reduction in cell proliferation compared to E2, but when combined with an EGFR inhibitor (Gefitinib) showed a synergistic effect by decreasing proliferation further that by Gefitinib alone. Ongoing experiments include the effects of Icaritin (modulator of ERα36) and the siRNA experiments to test the effects in cell proliferation, migration and invasion. This study will provide the foundation for further characterization of the role estrogen non‐genomic signaling in the progression of IBC and to test its potential as a therapeutic target.Support or Funding InformationSupport by RISE Program Grant number: 5R25GM061151‐18
How to be a Giant: Hypermetric Scaling of the Leg in Cockroaches and Scarab Beetles Suggests Oxygen Transport to the Legs Limits Maximal Insect Size
Authors: Harrison Jon F. , Wagner Julian M. , Aivazian Vahan , Duell Meghan E. , Klok C. Jaco , Weed Michael , Munoz Elyse , Fezzaa Kamel , Socha John Jacob , VandenBrooks John M. 
Published: April 2020

Understanding the causes and consequences of the evolution of large or small body size remains one of the important challenges of evolutionary biology. Insects have an unusual respiratory system, transporting oxygen in the gas phase via air‐filled tracheae. The possession of this unique system has been hypothesized to limit insect size, but how the morphology of the tracheal system changes as insects vary in size is still poorly known. Based on comparisons with vertebrates, we expect either geometric isometry in scaling (as found in lungs) or hypometric scaling (as found in vertebrate capillaries), with the latter matching the hypometric scaling of metabolic rate found for most animals. We tested these expectations by measuring the 3D morphology of tracheal systems of ten species each of cockroaches and scarab beetles. In both groups, body mass varied by more than an order of magnitude across species, which included some of the largest extant species of insect. Cockroaches were imaged at Argonne National Laboratory using synchrotron x‐ray microcomputed tomography (SR‐μCT), and scarab beetles were imaged at Virginia Tech using tabletop μCT. We measured the fraction of body volume occupied by the tracheal system for the major body compartments. In general, the tracheal system scaled isometrically in the head, thorax, and abdomen. However, within the legs, tracheal volume scaled strongly hypermetrically, resulting from an increase in number (in roaches) and size (in scarabs) of tracheae and/or air sacs. These data strongly suggest that evolution of larger species of insects requires increased relative investment in the tracheal system of the legs to overcome the challenges of long‐distance transport to muscles and nerves located in these long, blind‐ended structures, limiting the maximal size of insects.Support or Funding InformationSupported by NSF IOS 1122157 and IOS 1558052.
Inhibition of Sodium Glucose Cotransporter‐2 Improves Cardiac Efficiency During Regional Myocardial Ischemia Independent of Sodium/Hydrogen Exchanger‐1
Authors: Baker Hana , Tune Johnathan , Mather Kieren , Blaettner Bianca , Clark Hannah , Kowala Mark , Fliegel Larry , Goodwill Adam 
Published: April 2020

Recent clinical outcome studies demonstrate that inhibitors of the type 2 sodium glucose cotransporters (SGLT2i) significantly reduce major adverse cardiovascular events and heart failure outcomes in type 2 diabetes mellitus. The mechanisms underlying these clinical benefits remain to be elucidated. We tested the hypothesis that SGLT2i improves cardiac function and efficiency during acute, regional ischemia/reperfusion injury via inhibition of cardiac sodium/hydrogen exchanger‐1 (NHE‐1). Lean swine (~50 kg) were anesthetized, a thoracotomy was performed, and perivascular flow transducers were placed around the left anterior descending and circumflex coronary arteries. A pressure‐volume catheter was then inserted into the left ventricle. Swine received a 15–30 min (0.05–0.1 mL/min) infusion of vehicle (DMSO), the SGLT2i canagliflozin (30 μM), or the NHE‐1 inhibitor (NHE‐1i) cariporide (1 μM) immediately prior to a 60 min occlusion of the left circumflex artery followed by a 2‐hour reperfusion period. Mean arterial pressure decreased from ~91 ± 3 mmHg at baseline to ~62 ± 3 mmHg following 60 min of myocardial ischemia in control, canagliflozin and cariporide treated swine. Heart rate averaged ~78 beats/min at baseline and throughout the ischemic period, however, SGLT2i significantly increased heart rate during reperfusion compared to control and NHE‐1i treated swine. SGLT2i was associated with a significant increase in left ventricular end diastolic volume (P = 0.02) that corresponded with a significant increase in stroke volume (P = 0.03) and cardiac efficiency (P < 0.001) relative to control animals. End diastolic volume, stroke volume, and efficiency were not significantly affected by ischemia/reperfusion injury in either the control or NHE‐1i treated animals. Additional fluorometric assays of antiport‐deficient Chinese hamster ovary (AP‐1) cells transfected with wild‐type NHE‐1 showed dose‐dependent inhibition of NHE‐1 activity by cariporide (IC50 = 0.11 mM), while canagliflozin had minimal effect on overall activity. This investigation demonstrates that SGLT2i improves cardiac function and efficiency during acute, regional ischemia in healthy swine. However, these data argue against an important role of NHE‐1 inhibition in mediating the beneficial cardiac effects of SGLT2i.Support or Funding InformationEli Lilly and Company