bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pansteatitis in the Nile Crocodile: A Glimpse into the Pathophysiology using RNA‐Seq and bioinformatics
Authors: Azeez Odunayo Ibraheem , Myburgh Jan , Sibeko-Matjila Kgomostso , Bosman Ana-Mari , Featherstone Jonathan , Oosthuizen Marinda , Chamunorwa Joseph 
Published: April 2020

Concerted efforts to identify the pathogenesis and mechanism(s) involved in pansteatitis, that was attributed to the recent crocodile die off in the Kruger National Park, South Africa have been in the forefront of investigation in recent time. As part of the efforts, molecular characterization of healthy and pansteatitis adipose tissue was carried out by RNA sequencing (RNA‐Seq) using Next Generation Sequencing (NGS) and de novo assembly of the adipose transcriptome, followed by differential gene expression analysis.Healthy adipose tissue consisting of fifty samples was collected from the subcutaneous, visceral, intermuscular adipose tissues and the abdominal fat body of ten 4 years old juvenile crocodiles from a local crocodile farm in Pretoria, South Africa. Ten pansteatitis samples were collected from visceral and intermuscular adipose tissues of five crocodiles that were dying of pansteatitis.Seventy genes were differentially expressed in pansteatitis. They include genes coding for extracellular matrix (ECM) signaling ligands, inflammatory cytokines and tumour necrosis factor alpha (TNFα) receptors, fatty acid synthase and fatty acid binding proteins, peroxisome proliferator‐activated receptor gamma (PPARγ), nuclear factor and apoptosis signaling ligands, and mitogen activated protein kinase enzymes among others. Majority (88.6%) of the upregulated genes were found to be involved in hypoxia inducible pathways for activation of NFkβ and inflammation, apoptosis, Toll‐like receptor pathway and PPARγ. Bicaudal homologous 2 Drosophila gene (BICD2) associated with spinal and lower extremity muscle atrophy was also upregulated in pansteatitis while Sphingosine‐1‐phosphate phosphatase 2 (SGPP2) involved in Sphingosine‐1‐phosphate metabolism was downregulated. Futhermore, Doublesex –mab‐related transcription factor 1 (DMRT1) responsible for sex gonad development and germ cell differentiation was also downregulated.Thus, from the present study, based on differentially expressed genes in pansteatitis, affected Nile crocodiles might have died partly due to their inability to utilize stored triglycerides as a result of inflammation induced insulin resistance, leading to starvation in the midst of plenty. Affected animals may have also suffered muscular atrophy of the lower extremities and poor fertility.
Comparable Blood Velocity Changes in Middle and Posterior Cerebral Arteries During and Following Acute High‐Intensity Exercise in Young Fit Women
Authors: Labrecque Lawrence , Drapeau Audrey , Rahimaly Kevan , Imhoff Sarah , Billaut François , Brassard Patrice 
Published: April 2020

The influence of high‐intensity exercise training (HIIT) on cerebral blood flow (CBF) regulation remains unclear. HIIT induces surges in mean arterial pressure (MAP), which could be transmitted to the brain, especially early after exercise onset. The aims of this study were to 1) describe regional CBF changes during and following 30 s of high‐intensity exercise and; 2) examine whether dynamic cerebral autoregulation (dCA) is associated with CBF changes. Ten women (age: 26 ± 6 yrs; VO2max: 48.6 ± 3.8 ml×kg×min−1) cycled for 30 s at the workload reached at VO2max followed by 3 min of passive recovery. dCA was characterized using transfer function analysis of forced oscillations induced by repeated squat‐stands (0.05 and 0.10 Hz). Middle (MCAvmean) and posterior cerebral artery mean blood velocities (PCAvmean; transcranial Doppler), MAP (finger photoplethysmography) and end‐tidal carbon dioxide partial pressure (PETCO2; gaz analyzer) were measured. MCAvmean (+19 ± 10%) and PCAvmean (+21 ± 14%) increased early after exercise onset, returning toward baseline values afterwards. MAP increased throughout exercise (p<0.0001). PETCO2 initially decreased by 3 ±2 mmHg (p<0.0001) before returning to baseline values at end‐exercise. During recovery, MCAvmean (+43 ±15%), PCAvmean (+42 ± 15%) and PETCO2 (+11 ± 3 mmHg; p<0.0001) increased. TFA gain was higher in the MCA (p < 0.0001). Other dCA metrics were comparable between arteries and unrelated to exercise‐induced cerebral blood velocity changes. In young fit women, blood velocity changes during and following a 30‐s high‐intensity exercise are comparable between MCA and PCA and unrelated to dCA.Support or Funding InformationL.L. and S.I. are supported by a doctoral training scholarship from the Fonds de recherche du Québec – Santé (FRQS).
Nicotine‐Induced Glomerular Injury is Ameliorated in NLRP3 Gene Knockout Mice
Authors: Puchchakayala Goverdhan , Li Xiang , Koka Saisudha , Boini Krishna M. 
Published: April 2020

Nicotine, a major compound of tobacco and the key component of the vapor inhaled via electronic cigarettes, has been shown to worsen kidney injury in animal models of acute kidney injury, diabetes, subtotal nephrectomy. However, it remains unknown how nicotine‐induced glomerular injury. Hence, the present study tested whether NLRP3 inflammasome mediates the nicotine‐induced glomerular injury. Uninephrectomized Nlrp3 knockout (Nlrp3−/−) and wild type (Nlrp3+/+) mice were fed a normal chow for 5 weeks with or without nicotine treatment to produce glomerular injury. Nicotine treatment significantly increased the colocalization of Nlrp3 (Nod‐like receptor protein 3) with ASC (apoptosis‐associated speck‐like protein) or Caspase‐1 in glomeruli of Nlrp3+/+ mice than in vehicle treated mice. However, such nicotine‐induced increases in colocalization of Nlrp3 with ASC or Caspase‐1 was attenuated in Nlrp3−/− mice. In consistency with decreased inflammasome formation, the caspase‐1 activity and IL‐1β production was significantly attenuated in glomeruli of Nlrp3−/− mice. Morphological examinations showed that nicotine‐induced profound injury in glomeruli of Nlrp3+/+ mice which was markedly attenuated in Nlrp3−/− mice. The decreased glomerular damage index in Nlrp3−/− mice was accompanied by attenuated proteinuria. Immunofluorescence analysis showed that the nicotine treatment significantly decreased the expression of podocin but increased desmin levels in glomeruli from Nlrp3+/+ mice but not in those from Nlrp3−/− mice. Furthermore the nicotine‐induced hypertension was significantly attenuated in Nlrp3−/− mice. In conclusion, these observations disclose a pivotal role of Nlrp3 inflammasomes in mediating the glomerular sclerosis associated with smoking.Support or Funding InformationR01DK104031 and R56HL143809
Chemotherapy Stress Induces Translocation of Mitochondrial Enzymes to the Nucleus and a Nuclear Metabolomic Shift in Cardiomyocytes Derived from Human Induced Pluripotent Stem Cells
Authors: Srivastava Shubhi , Miyamoto Hiroe , Ong SangGing , Rehman Jalees 
Published: April 2020

BackgroundDoxorubicin is a highly effective chemotherapeutic agent which can induce severe cardiomyopathy and heart failure in more than 30% of the patients receiving this treatment. Human iPSC‐derived cardiomyocytes (iPSC‐CMs) can be used to model chemotherapy‐induced cardiotoxicity as well as identify adaptive stress mechanisms. We studied the metabolic responses of iPSC‐CMs to doxorubicin in order to identify mechanisms of metabolic injury as well as metabolic adaptation to stress.Methods and ResultsWe studied iPSC‐CMs following short (6 h) and prolonged (24 h) doxorubicin treatment. We observed that doxorubicin stress induces the translocation of mitochondrial TCA cycle enzymes to the nucleus during the course of treatment with ~15 % of the TCA cycle enzymes translocate to the nucleus in 6 h and 30 % in 24 h (p value <0.0001). The compartment specific metabolomic analysis of the nuclear fraction showed that the enzyme translocation induced a metabolic shift in the nuclear compartment, indicating that the translocated enzymes were metabolically active in the nucleus. Super‐resolution microscopy demonstrated that the translocation of TCA cycle enzymes was mediated by carrier vesicles originating from mitochondria. We observed that the metabolic rewiring in the nucleus alters the nuclear NAD+ levels and therefore fuels the activity of cardioprotective nuclear sirtuins by ~2 fold in 6 h of doxorubicin treatment which further increases to ~2.7 fold in 24 h (p value <0.0001).ConclusionThe recent discovery that mitochondrial TCA cycle enzymes can be found in the nuclei of cells where they generate locally acting nuclear metabolites and modulate the epigenome has raised intriguing possibilities regarding mitochondrial‐nuclear crosstalk during stress. Our findings suggest that mitochondrial enzyme translocation to the nucleus may initiate metabolic adaptation which increases the activity of sirtuin histone deacetylases. In light of the known cardioprotective function of sirtuin activation, stress‐induced mitochondrial enzyme translocation may serve as a potential novel therapeutic target to reduce chemotherapeutic cardiotoxicity.Support or Funding InformationNIH HL 126516
Electronic‐cigarette Vapor Exposure Causes Impaired Left‐Ventricular Relaxation and an Inflammatory Response in Male Adolescent Mice
Authors: Neczypor Evan William , Gorr Matthew W. , Mears Matthew J. , Schweiterman Neill A. , Anaruma Chadi Pellegrini , Grimmer Jacob A. , Muffler Michael D. , Wold Loren E. 
Published: April 2020

ObjectiveElectronic cigarettes (e‐cigs) are the most commonly used tobacco product by teens and young adults. The aim of the present study was to determine the potential effects of e‐cig vapor exposure on cardiac function in adolescent mice.Materials and MethodsFour‐week‐old FVB/NJ male mice were separated into three exposure groups: 1) e‐cig exposure with nicotine (EC(+)) (20.2 mg nicotine/1 mL 50:50 propylene glycol:vegetable glycerin), 2) e‐cig exposure without nicotine (EC(‐)), or 3) filtered air exposure (FA) (HEPA filter), and exposed for three months. A puff profile consisting of one 70‐mL e‐cig vapor puff per minute of exposure was administered for 4 h/day, 5 days/week over the course of three months, and filtered air was administered continuously throughout the 4‐hour periods. Cotinine concentration in the serum of mice from either group was determined using a cotinine ELISA. Echocardiography was used to examine global cardiac function after 1, 2, and 3 months of exposure. Following the exposure period, mice were sacrificed within 24 hours of exposure, and heart tissue and serum was collected. Serum was analyzed for 42 cytokines by Ampersand Bioscience’s Rodent MAP 4.0 service. Left ventricular (LV) cardiac lysates were examined for protein expression via western blot.ResultsThe average cotinine concentration in the serum of the EC(+) mice after three months of exposure was 189 ng/mL, while there was not a detectable concentration of cotinine in the serum of EC(‐) or FA mice. Echocardiography illustrated significant reduction in the E/A ratio for mitral flow in mice exposed to EC(+) as early as two months into exposure. There were no significant alterations in ejection fraction (%EF), fractional shortening (%FS), or posterior wall thickness (PWT). The cytokine panel showed significant increases in the concentrations of MCP‐1, IL‐18, and MIP‐1β in EC(+) compared to FA, and increases in SCF and VEGF for both EC(‐) and EC(+) compared to FA. Cardiac fibrosis was observed via an increase in collagen I levels in LV tissue of EC(+) compared to EC(‐) and FA. Additionally, a decrease in phosphophospholamban and phospho‐troponin I was observed in EC(+) LV tissue, suggesting alterations in calcium cycling and myofilament regulation.ConclusionsE‐cig exposure causes early signs of impaired cardiac relaxation with no observed systolic dysfunction in adolescent male mice. Fibrosis, alterations in calcium cycling, and inflammation may contribute to the observed dysfunction.Support or Funding InformationProject was supported by a grant from the National Institutes of Health (1R01HL139348‐01) to LEW.
Loss of Evolutionarily Acquired Functions of Atp1b4 leads to Increase Energy Expenditure and Protection Against Diet‐Induced Obesity of Adult Mice
Authors: Modyanov Nikolai 
Published: April 2020

Co‐option of vertebrate orthologous ATP1B4 genes in placental mammals radically changed properties of the encoded BetaM‐proteins. These proteins in lower vertebrates are authentic Na, K‐ATPase β‐subunits which in complex with a‐subunits function as ion pumps in the plasma membrane.In placental mammals BetaM proteins gained entirely different properties through structural changes of N‐terminal domains. As a result of these evolutionary alterations, eutherian BetaM completely lost its ancestral role and became the only currently known skeletal and atrial cardiac muscle‐specific protein of the inner nuclear membrane, which is expressed at highest level during perinatal development and is implicated in gene expression regulation.Loss of BetaM the Atp1b4 knockout mouse model results in significantly lower body size and weight, growth retardation and high mortality of neonates. Transcriptome analysis by mRNA sequencing of skeletal muscle from neonatal wild type and knockout littermates revealed broad changes in expression of genes regulating lipid metabolism. These results imply that BetaM plays an essential role during a critical period of perinatal and neonatal development of placental mammals and its damage or malfunction can cause birth and growth defects in humans.Most importantly, Atp1b4 disruption exhibits a somewhat unexpected and profound beneficial effect of on metabolic parameters in adult male mice. BetaM deficient (Atp1b4‐/Y) mice have significantly lower body weight and remarkably low adiposity. They exhibit lower fasting blood glucose, enhanced insulin sensitivity and improved glucose tolerance and are resistant to high‐fat diet‐induced obesity as compared to their wild type littermates. Knockout mice display higher heat production associated with increased food intake, elevated oxygen consumption especially in darkness and higher locomotor activity. Lower respiratory exchange ratio of knockout mice indicates that fat from high‐fat diet is metabolized rather than deposited as storage. These robust changes in mouse metabolic parameters induced by Atp1b4 disruption clearly demonstrate that eutherian BetaM plays the important role in development of pathways regulating metabolism of adult mice.Finally, ablation of the evolutionarily acquired functions of Atp1b4 gene in mice is in fact a simulation of the alternative pathway of mammalian evolution.Support or Funding InformationThis work was supported by College of Medicine and Life Sciences, Center for Diabetes and Endocrine Research and Department of Physiology & Pharmacology, University of Toledo
Designing Cell Biosensors to Detect Incremental Glucagon Expression
Authors: Ennis Teresa Annmarie , Kolar Grant R. , Samson Willis K. , Yosten Gina L. C. 
Published: April 2020

Hypoglycemia is a highly prevalent complication for patients with Type 1 Diabetes. Research into alpha cell function and glucagon release has been hampered because current methods used to measure glucagon, such as ELISA, are limited in sensitivity and specificity. In order to uncover the targets and pathways involved in alpha cell dysfunction in type 1 diabetes, we have designed multipurpose glucagon biosensors to detect changes in glucagon release on a cellular level and in real time. To generate the glucagon biosensors, HEK‐293 cells were transfected with a GCGR (RFP‐Tagged) Human Glucagon Receptor vector, along with GCamP6s calcium reporter (GFP). Once transfected, they were maintained and selected for using media consisting of puromycin and G418. This selection allows the cells with the incorporated vectors to be isolated. We previously found that treatment of these cells with recombinant glucagon led to clearly visible increases in GCamP6s (GFP) fluorescence. To better simulate hypoglycemic conditions, immortalized alpha cells were co‐cultured with the glucagon biosensors, and the glucagon response was measured. This system could provide a novel model for evaluating the regulation of glucagon release from alpha cells as well as the dynamics of glucagon release following exposure to hypoglycemic conditions. In future experiments, we will expose the cells to environmental stressors, such as a pro‐inflammatory cytokines, to determine their effects on glucagon release. In summary, the glucagon biosensors can offer enlightening information about sensitivity along with specificity of cellular interactions in real‐time.Support or Funding InformationFunding is supported by the Helmsley Charitable Trust
Cocaine receptor identified as BASP1
Authors: Harraz Maged M. , Malla Adarsha P. , Semenza Evan R. , Shishikura Maria , Kang In Guk , Snowman Adele M. , Cortés Pedro , Song Young Jun , Hwang Yun , Snyder Solomon H. 
Published: April 2020

Cocaine is a behavioral stimulant with substantial abuse potential related to its positively rewarding actions. Definitive molecular mechanisms of action have not been established, though cocaine is known to inhibit the reuptake inactivation of monoamine neurotransmission at high nanomolar to low micromolar concentrations. There is evidence for significantly more potent neurochemical and behavioral actions of cocaine that could not be attributed to the inhibition of monoamine transporters. Thus, evidence for a specific, high affinity cocaine receptor that mediates its behavioral actions has been lacking. In the present study we report high affinity binding of cocaine to the membrane‐associated protein BASP1, which appears to be a pharmacologically relevant cocaine receptor. Utilizing affinity pull‐down, mass spectrometry and ligand binding assays, we establish that BASP1 is a high‐affinity cocaine binding protein (Kd 7 nM). Our data show that knocking down BASP1 in the nucleus accumbens or striatum (pre‐ and post‐synaptic) inhibits behavioral actions of cocaine and reduces [3H]cocaine binding to striatal synaptosomes respectively. Taken together, our data suggest that BASP1 is a high‐affinity receptor for cocaine.Support or Funding Information Fundingthis work was supported by U.S. Public Health Service Grants DA00266 and DA044123 to SHS and a NARSAD Young Investigator Grant (grant # 25360) from the Brain & Behavior Foundation to MMH.
Gap Junction Intercellular Communication and Coronary Microvascular Disease in Type 2 Diabetes
Authors: Cabrera Jody Tori O. , Si Rui , Makino Ayako 
Published: April 2020

Recent reports demonstrate that diabetic patients with coronary microvascular disease (CMD, also known as non‐obstructive coronary artery disease) exhibit higher cardiac mortality than diabetic patients without CMD. However, the molecular mechanisms in which diabetes leads to CMD are not well understood. In this study, we examine the role of gap junction intercellular communication in the development of CMD in diabetes. We used type 2 diabetic (T2D) mice induced by a single injection of low‐dose streptozotocin (75 mg/kg) with a high‐fat diet (60 % kcal). Coronary flow velocity reserve (CFVR) was measured in mice to assess coronary microvascular function and T2D mice showed significant decrease in CFVR compared to control mice, suggesting that T2D mice are suffering from CMD. Mouse coronary endothelial cells (MCECs) isolated from T2D mice and human coronary endothelial cells (HCECs) treated with high‐glucose exhibited the reduction of gap junction activity compared to their controls. Gap junction is composed of connexins (Cxs) and coronary endothelial cells express Cx37, Cx40, Cx43, and Cx45. Among those Cxs, Cx40 mRNA level was significantly decreased in MCECs isolated from T2D mice. Furthermore, Cx40 protein levels were significantly decreased in MCECs from inducible T2D mice, MCECs from spontaneous T2D mice (Tallyho mice), and HCECs from T2D patients compared to those controls. Cx40 knockout mice exhibited lower CFVR which was accompanied by decreased capillary density in the left ventricle (LV), when compared to the wild‐type mice. The potential causes of decreased capillary density include attenuated endothelial migration/proliferation and increased endothelial apoptosis. In ex vivo, high‐glucose treatment impaired capillary network formation in HCECs and Cx40 overexpression restored the level of capillary network in high‐glucose treated HCECs. We also found that Cx40 overexpression in T2D mice increased capillary density in the LV and CFVR. These data suggest that the downregulation of Cx40 decreases capillary density in the heart and leads to CMD in diabetes. Therefore, Cx40 overexpression in ECs could be the potential therapy for CMD in diabetic patients.Support or Funding InformationThis work was supported by grants from the National Heart, Lung, and Blood Institute of the National Institutes of Health (HL142214 and HL146764 to A. Makino).
Genome‐wide Screening Uncovers Transforming Growth Factor‐β3 as Regulator of Glycosaminoglycan Assembly
Authors: Rother Sandra , Weiss Ryan J. , Esko Jeffrey D. 
Published: April 2020

Heparan sulfate (HS) and chondroitin sulfate (CS) are glycosaminoglycans covalently linked to proteoglycans (PG) present on all cell surfaces and in the extracellular matrix. They play a complex role in carcinogenesis as they are important for extracellular matrix remodeling as well as cell‐cell and cell‐matrix interactions. These processes are altered during malignancy, when tumor cells invade and systemically spread in different tissues. We have developed a genome wide screening method using CRISPR‐Cas9 gene targeting to identify novel genes involved in glycosaminoglycan metabolism. The approach utilizes agents that bind specifically to cell surface HS. One of the top hits was transforming growth factor‐β3 (TGF‐β3), a growth factor that controls multiple genes with tumor‐suppressing and tumor‐promoting effects. Cell surface levels of PG were evaluated in A375 melanoma cells after treatment with soluble TGF‐β1 or TGF‐β3 in the presence or absence of a TGF‐β type I receptor inhibitor (SB‐431542) using specific agents that bind to glycosaminoglycans, including mAbs 10E4 or CS56, guanidinylated neomycin and fibroblast growth factor‐2 (FGF2). Both TGF‐β isoforms stimulated cell surface HSPG and CSPG expression, that was blocked by SB‐431542. Inactivation of TGF‐β3 expression by CRISPR/Cas9 had the opposite effect. These findings show that TGF‐β3 is a newly identified regulatory factor of PG assembly in melanoma cells and that tonic expression of TGF‐β3 regulates PG production in a cell autonomous manner. Further exploration how TGF‐β affects disorders associated with altered PG formation in cancer might lead to innovative solutions to alter tumor cell growth and metastasis.Support or Funding InformationWe acknowledge financial support by the DFG (research fellowship, project number 420160411) and the NIH (fellowship award, K12HL141956).