bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arf6 Heterozygosity Results in Impaired Glucose Tolerance Due to Abberant Hepatic Gluconeogenesis
Authors: Dutson Tavia , Islam Md Torikul , Cai Jinjin , Sun Zhonglou , Fang Daniel , Donato Anthony J. , Zhu Weiquan , Lesniewski Lisa A. 
Published: April 2020

Adenosine diphosphate (ADP) ribosylation factor 6 (Arf6) is a small GTPase that plays a critical role in numerous cellular processes including proliferation and membrane trafficking. Arf6 has been found to be dysregulated in diseases such as diabetic retinopathy and tumor metastasis. Furthermore, genetic insufficiency or pharmacological inhibition of Arf6 is protective in the aforementioned diseases, suggesting that Arf6 may be a potential therapeutic target. Here, we assessed the metabolic consequences of a reduction in Arf6 expression by performing glucose (GTT: 2 g/kg, ip), insulin (ITT: 1 U/kg, ip) and pyruvate (PTT: 2 g/kg, ip) tolerance tests in 3–4 mo old whole body Arf6 heterozygote (Arf6+/−) and wildtype (Arf6+/+) littermate control mice. Both protein and gene expression of Arf6 in the liver were 40–50% lower (p<0.05) in Arf6+/− mice compared to Arf6+/+. Body mass was higher in normal chow fed Arf6+/− compared to Arf6+/+ mice (30.3±0.9 vs 36.4±2.0 g, p<0.05). Blood glucose at 15, 30, and 60 min after injection during the GTT were 20–30% higher in Arf6+/− mice compared to Arf6+/+ (each p<0.05). Likewise, the area under the GTT time response curve was ~15% higher in Arf6+/− compared to Arf6+/+ (p<0.05), indicating impaired glucose metabolism. To examine the underlying cause of this glucose intolerance, we performed an ITT and assessed insulin‐stimulated suppression of plasma free fatty acids 15, and 30 min after insulin injection. We found no groups differences between the ITT time response curves (p>0.05) and no difference in the percent decrease in plasma FFAs from fasted between Arf6+/− and Arf6+/+ mice (~50% vs ~50% p>0.05). Likewise, fasted and glucose‐stimulated (2g/kg, ip) serum insulin were not different between the groups (2.44±0.58 vs 1.73±0.28, fasted; 4.54±1.74 vs 4.03±1.68 insulin stimulated; both p>0.05), suggesting that reductions in Arf6 expression do not impact pancreatic beta cell insulin secretion. Collectively, these measures suggest that neither peripheral insulin resistance nor impaired pancreatic beta cell function underlie glucose intolerance in Arf6+/− mice. To determine the contribution of hepatic gluconeogenesis to the observed glucose intolerance in the Arf6+/− mice, we performed a PTT and found that Arf6+/− mice exhibited a 15–25% increase in blood glucose over time compared to Arf6+/+ mice (p<0.05), suggesting a role for elevated hepatic gluconeogenesis. Taken together, this study demonstrates that Arf6 heterozygosity impairs glucose metabolism that is associated with aberrant hepatic gluconeogenesis but is independent of peripheral insulin resistance or pancreatic beta cell dysfunction.Support or Funding InformationNIA R01 AG048366, R01 AG050238 and K02 AG045339, R01 AG060395 and US Department of Veterans Affairs I01 BX002151, I01 BX004492.
The Iron‐responsive, Uropathogenic E.coli Exometabolome Is Dominated by Multiple Enterobactin‐derived Catechols
Authors: Zou Zongsen , Robinson John , Steinberg Lindsey , Henderson Jeffrey P. 
Published: April 2020

Uropathogenic E. coli possess numerous iron‐responsive genes that are transcriptionally upregulated during human and experimental cystitis. These gene products are involved in diverse functions, including transporters and biosynthesis of specialized metabolites with virulence‐associated functions. Here, we sought to identify iron‐responsive exometabolites in experimental cultures of the model uropathogenic E. coli strain UTI89. Using comparative metabolomics, we detected multiple iron‐regulated products related to the siderophore enterobactin. In addition to observing the canonical siderophores enterobactin and salmochelin, we also detected siderophore structurally related, lower molecular weight metabolites of unknown origins. We considered that these low molecular weight products may derive from premature release from the biosynthetic complex (anabolic products) or from degradation of the full siderophore (catabolic products). In siderophore import‐deficient UTI89ΔtonB, low molecular weight catechols were substantially attenuated, in particular for the glucosylated derivatives, which favors a catabolic source of low molecular weight catechols resulting from import and incomplete hydrolysis of ferric enterobactin and salmochelin. When siderophore biosynthetic mutants were cultured with purified enterobactin, enterobactin was consumed while low molecular weight catechol products were not generated. And isotope‐labelling experiments suggest that complete enterobactin hydrolysis products may be recycled by bacteria within the cells for subsequent rounds of enterobactin biosynthesis. The results then raise a new hypothesis of glucosylation resulting in different enterobactin and salmochelin catabolisms, which is currently being investigated. The secreted exometabolome of uropathogenic E. coli includes not only siderophores but siderophore‐related products that arise from transport, hydrolytic, and recycling pathways that may relate to these organisms’ pathogenic potential.Support or Funding InformationAcknowledgements:This work was supported by a CDC Prevention Epicenters Program Grant CU54CK000162 and National Institutes of Health R01DK099534 and R01DK111930 to JPH.
The Development of Novel Therapeutics Against Schistosomiasis
Authors: Alwan Sevan Najm , Jr Rolando Trevino , Romero Claudia Moreno , Taylor Alexander B. , Rhodes Jayce , Tidwell Michael , Becker Stanton F. , LoVerde Donald T. 
Published: April 2020

Human schistosomiasis is a neglected tropical disease caused by parasitic worms. It affects over 250 million people globally. Most human infections are caused by S. mansoni, S. haematobium, and S. japonicum. Currently there is only one method of treatment for human schistosomiasis, the drug praziquantel. Constant selection pressure has caused a serious concern for a rise in resistance to praziquantel leading to the necessity for additional pharmaceuticals, with a distinctly different mechanism of action, to be used in combination therapy with praziquantel.Previous treatment of Schistosoma mansoni included the use of oxamniquine (OXA), a prodrug that is enzymatically activated by a Sulfotransferase, an enzyme produced by S. mansoni (SmSULT). Although sulfotransferases are produced by S. haematobium and S. japonicum, OXA is not effective against these two species. By using information from the crystal structure of SmSULT bound to OXA, 250 OXA derivatives were designed and tested in vitro against the adult parasites. We were able to identify effective derivatives that kill Schistosoma mansoni (85%), S. haematobium (40%) and S. japonicum (83%). Recently, we identified CIDD‐149830 as an effective derivative that can kill all three schistosome species (100%) within 7 days in vitro. In vivo studies results show a significant reduction in the number of harvested worms from infected animals after treating them with CIDD‐149830.In this study, we re‐engineered and tested 42 derivatives based on the structure of CIDD‐149830 and we were able to identify CIDD‐0150610 as a very powerful derivative that kills 100 % of Schistosoma mansoni overnight in vitro.Support or Funding InformationR01 AI115691
Therapeutic Effects of Magnesium Biotinate on Propionic Acid‐Induced Autistic Features in Rats
Authors: Sylla Sarah , Komorowski James , Ojalvo Sara Perez , Orhan Cemal , Tuzcu Mehmet , Sahin Nurhan , Bozoglan Merve Yılmaz , Sahin Kazim 
Published: April 2020

ObjectiveThis study investigated the therapeutic effects of magnesium biotinate (MgB) on propionic acid (PPA)‐induced autistic features in rats.BackgroundBiotin is involved in energy metabolism and various immune and nerve functions. MgB is a novel biotin complex that has enhanced absorption. Compared to D‐Biotin, MgB has superior tissue uptake and anti‐inflammatory effects. Biotin deficiency can result in neurological abnormalities. Low levels of biotin have been found in individuals with neurodevelopmental disorders such as autism spectrum disorder.Design/MethodsThirty‐five male Wistar rats (3 weeks old) were randomized into the following five groups; 1: Control (received saline), 2: PPA alone, 3: PPA + 10 mg human equivalent dose (HED) MgB, 4: PPA + 100 mg HED MgB, 5: PPA + 500 mg HED MgB. PPA treated rats were administered 500 mg/kg BW/day of PPA by subcutaneous injection for 5 days to induce autistic features. Treatment groups then received MgB for two weeks via oral gavage following PPA treatment. Neurobehavioral tests were performed on the seventh and eighth days. Serum and tissue samples were then collected for analysis.ResultsThe neuronal loss and degeneration observed in the hippocampal CA1 region and cerebellum of PPA‐exposed rats were improved by treatment with MgB. Brain levels of oxidative stress and inflammatory markers were lower in all MgB groups compared to PPA alone (p<0.05). Brain levels of antioxidant markers were higher in the 100 and 500 mg HED MgB groups compared to PPA alone (p<0.05). These effects were most significant in the 500 mg HED MgB group. Sociability and social preference scores were greater in the 100 and 500 mg HED MgB treatment groups compared to PPA alone (p<0.05). The 500 mg HED MgB dose improved social preference score to the extent that it did not differ from normal controls.ConclusionsTreatment with MgB significantly reduced brain toxicity and improved autistic features induced by PPA.Support or Funding InformationThis study was conducted at Firat University and funded by JDS Therapeutics, LLC.
Investigation of the pro‐inflammatory effects of biomass exposure on RAW264.7 macrophages
Authors: Williams A’Kayla , Jones Shannon 
Published: April 2020

Biomass smoke is a common component of indoor air pollution that affects millions of people worldwide. Indoor air pollution has been demonstrated to induce inappropriate activation of the immune system and pro‐inflammatory responses. In some underdeveloped regions of the world, individuals are especially susceptible to the negative health effects associated with biomass smoke exposure and indoor air pollution. In many cases, which citizens’ homes do not have the proper air filtration, are they are therefore disproportionately affected by indoor air pollution exposure. Individuals chronically exposed to indoor air pollution often suffer from recurring upper respiratory infections and exacerbated asthma. The mechanisms that lead to these negative health outcomes are mostly unknown, but are thought to be mediated by activated cells of the innate immune system. The purpose of this research was to examine the impacts of woodsmoke on macrophages, a key mediator of innate immunity. RAW 264.7 macrophages were challenged with woodsmoke to and assessed for pro‐inflammatory responses. We hypothesized that an increasing concentration of woodsmoke would be damaging to the macrophages and would result in higher levels of cytokine production and release in nitric oxide. Multiple assays were performed to measure cytotoxicity, cytokine production and nitric oxide release. Some of the cytokines that were measured include MIP‐2 and TNF‐alpha, both of which are upregulated during inflammatory responses in macrophages. The LDH assay was used to assess the cytotoxicity of woodsmoke in treated macrophages. Our results thus far demonstrate, the following exposure to wood smoke, the release of MIP‐2 and TNF‐alpha was significantly increased following wood smoke exposure. Furthermore, the wood smoke exposure induced minimal amounts of cellular toxicity.Support or Funding InformationUniversity of Richmond’s Integrated and Inclusive Science Program
The role of miR‐146a‐5p on insulin signaling and inflammation in adipose tissue of longliving Ames dwarf mice.
Authors: De Carvalho Nunes Allancer Divino , Yu Lin , Lahde Collin , Noureddine Sarah , Saccon Tatiana , Schneider Augusto , Masternak Michal 
Published: April 2020

MicroRNAs have been shown to be potent regulators of various biological processes. Multiple miRNAs are regulated during aging in several tissues from mice. Previous studies have indicated the MicroRNA 146a‐5p (miR‐146a) is increased during aging in the circulation, in a wide variety of tissues and different models of replicative aging. Importantly, this miRNA is also associated with cellular senescence, metabolic syndrome and inflammation. Thus, the aim of this study was to determine the mechanistic role of miR‐146a in insulin sensitivity and inflammation in visceral fat tissue in vivo. For this we used Long‐living Ames dwarf (df/df) and normal (N) female mice were subjected to five intraperitoneal injections of a miR‐146a mimetic (miR‐146a‐m) with two day intervals between each injection. Before the treatment, mice were randomly divide into five experimental groups: normal mice control, normal mice miR‐146a‐m 4 mg/kg, df/df control, df/df miR‐146a‐m 4mg/kg and df/df miR‐146a‐m 8 mg/kg. Overall, RT‐PCR analysis indicated that in vivo treatment with miR‐146‐m increased the expression level of miR‐146a in visceral fat tissue in both N and df/df mice. Importantly, in df/df the treatment with miR‐146a‐m 8 mg/kg significantly increased P16 gene expression, a known senescence marker, and reduced adiponectin, IRS2 and AKT1 gene expression. Moreover, the analysis of PI3K, IRS1, PPAR&#x01B4; and PPARα gene expression in visceral fat showed a trend towards downregulation in response to treatment with miR‐146a‐m at 8 mg/kg. In summary, this study showed that miR‐146a regulated the expression genes related to insulin sensitivity in visceral fat tissue in long‐living df/df mice as compared to normal mice. Additionally, our data suggest that miR‐146a might suppress insulin sensitivity and stimulate inflammation through suppression of adiponectin levels.Support or Funding InformationThis research study is supported by National Institutes of Health (NIH) (R15AG059190, R03AG059846 and R56AG061414)
Renal hemodynamics and metabolism improve following a second Exertional Heat Stroke
Authors: Kolb Alexander Louis , Geddis Alyssa , Reynoso Mainaliz , Ward Jermaine , Dineen Shauna , Leon Lisa 
Published: April 2020

Exertional Heat Stroke (EHS) occurs with rapid onset during strenuous exertion and results in hospitalization that is often associated with renal and hepatic injury. EHS may increase susceptibility to a subsequent EHS collapse if organ injury has not completely resolved prior to the second heat exposure. We investigated renal filtration and mitochondrial oxidative phosphorylation (OP) changes in radiotelemetered C57BL/6J mice that were forced to run in a heat chamber (37.5°C) until collapse (core temperature ~42.7°C). Mice were exposed to one (EHS) or two EHS events separated by 1 (EHS1), 3 (EHS3) or 7 (EHS7) days of recovery. Samples were collected 30 min, 3h, 1, or 7d after the first or second EHS exposure. Blood urea nitrogen (BUN; Abaxis VetScan analyzer) and a Mitochondrial Function Assay MitoPlate (Biolog) were used to assess renal filtration and OP changes, respectively. EHS1 mice experienced significantly greater thermal load (area under the heat curve) and dehydration compared to EHS, EHS3 and EHS7 mice (p<0.001), but hypothermia depth during recovery was significant less pronounced than the other groups (~35°C vs. 32°C, respectively; p<0.01). EHS1 mice showed 103% and 95% BUN decrease at 30 min and 3h of recovery compared with EHS, EHS3, and EHS7 groups, respectively (ANOVA, p<0.001). Analysis of OP kinetics revealed that the following Citric Acid Cycle enzymes increased: Pyruvate Dehydrogenase (78%), Citrate Synthase (77%), Isocitrate Dehydrogenase (66%), Aconotase (59%) Alpha‐Ketoglutarate Dehydrogenase (50%), Succinate Dehydrogenase (18%), Fumurase (37%), and Malate Dehydrogenase (50%) 3h following EHS1, EHS3 or EHS7 (p<0.05). All values were compared and normalized to naive control animals. The core temperature data indicate that EHS mice were partially acclimated prior to the second exposure on day 1 and this was sufficient to improve thermal tolerance (time in the heat before collapse) and reduce the severe sequelae during recovery. The minimal BUN changes EHS1 mice may be a consequence of increased glomerular filtration promoting normal renal hemodynamics. However, the kidney of EHS3 mice appeared to recover prior to the second exposure such that renal function was no longer adversely affected. The potential mechanism of these changes may be attributed to citric acid cycle kinetics of the renal mitochondria. These are the first data to indicate that partial heat acclimation in mice is sufficient to protect them against renal injury following a second heat exposure and this response has a 3d decay rate.Support or Funding InformationThe views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government. This abstract has been approved for public release with unlimited distribution.
Bone blood flow regulation in humans
Authors: Draghici Adina E. , Solinsky Ryan E. , Taylor J. Andrew 
Published: April 2020

Bone is a highly vascularized organ with an extensive network of arteries, arterioles, and capillaries that is critical for bone development, maintenance, and repair. Despite the importance of bone circulation to bone health, the regulation of blood flow to bone is not well understood in humans. One of the potential factors controlling bone blood flow is the sympathetic nervous system, bone vasculature being innervated by a rich network of sympathetic nerves. While no human studies have been conducted, animal data suggests that sympathetic activation reduces bone blood flow. If this were not the case, bone vasculature would respond simply as a passive pressure system. Therefore, we characterized bone blood flow regulation in health young individuals (N=12 (8M; 4F), 23±0.7 years) in response to isometric handgrip to fatigue (IHE). Sustained IHE is a profound pressor stimulus, resulting in active vasoconstriction in the nonactive leg and progressive increases in blood pressure. During IHE at 30% of maximal voluntary contraction, we measured blood pressure, whole leg blood flow (via Doppler ultrasound), and tibial blood perfusion (via near infrared spectroscopy). Tibial blood perfusion was determined as changes from resting baseline in oxygenated and deoxygenated hemoglobin content. Data is presented as mean change from resting baseline ± standard error. To account for different IHE time courses, all variables were normalized to 100% duration and averaged across individuals. Blood pressure increased progressively to end of IHE (at 10%: 5.46 ± 1.30 mmHg; at 100%: 48.0 ± 4.32 mmHg). Whole leg blood flow decreased progressively throughout IHE, suggesting active sympathetic vasoconstriction in the leg (at 10%: −0.70 ± 0.28 cm/s; at 100%: −2.26 ± 0.50 cm/s). Similarly, tibial oxygenated hemoglobin decreased progressively throughout the test (at 10%: −0.21 ± 0.31 μM; at 100%: −1.19 ± 1.12 μM) whereas tibial deoxygenated hemoglobin did not change significantly throughout IHE (at 10%: 0.06 ± 0.07 μM; at 100%: −0.4 ± 0.32 μM). This indicates that arterial flow (oxygenated hemoglobin) declined while bone metabolism (deoxygenated hemoglobin) remained unchanged in response to IHE. It should be noted that the decline in oxygenated hemoglobin was slower and lesser than that in whole leg blood flow. This data suggests that sympathetic activity is involved in controlling bone circulation, but vasoconstrictor responses is not as fast or as robust in bone as it is in the whole leg.Support or Funding InformationParalyzed Veterans of America (AED)
Water Networks and Allosteric Scaffolds ‐ What Does Water Have to do with Protein Dynamics?
Authors: Taverner Keith , Prosser Robert Scott 
Published: April 2020

The thermophilic enzyme Fluoroacetate Dehalogenase (FAcD) has been well characterized by crystallography and NMR. FAcD (RPA1163) is a homodimer alpha/beta hydrolase that breaks down haloacetates (including fluoroacetate, iodoacetate, and chloroacetate) into glycolate and a halogen ion. FAcD achieves this by half‐of‐sites activity, where the homodimer adopts a rare asymmetric state that is primed to capture substrate which must then diffuse along an 11 Å cavity before engaging the active site and adopting the Michaelis intermediate. This triggers release of ~30 bound water molecules, thereby entropically favouring the forward reaction. FAcD is thus an ideal model system to pursue paradigm shifting questions regarding allostery, interprotomer communication, and the role of hydrogen bonded water networks in catalysis ‐ all from an ensemble perspective. Here we examine how deuterium water (D2O) changes the dynamic and allosteric mechanisms of this system. Compared to water, D2O results in an increase in viscosity and has stronger hydrogen bonds. Through 19F NMR kinetic experiments we determine that despite the higher viscosity enzyme activity is increased in the D2O environment. Additionally, 19F NMR experiments reveal increased dynamics in D2O. This provides key insight into discrete hydrogen‐bonded water networks that are key to stabilization of allosteric processes associated with the reaction coordinate.Support or Funding InformationNatural Sciences and Engineering Research Council (NSERC)
Using HMGB1 Protein as a Surrogate Marker for Lung Cancer in High‐Risk Populations
Authors: Cole Breanna , Jeffords Eric , Simmons Glenn E. 
Published: April 2020

Lung cancer is the leading cause of cancer‐related death, independent of gender or ethnicity, with a 5‐year overall survival of 17.1%. Although screening protocols for early detection exist, lung cancer is often diagnosed at an advanced stage. This is due, in part, to many patients experiencing barriers to healthcare access which contribute to delays in diagnosis. Supra‐normal biosynthesis of saturated (SFA) and unsaturated fatty (UFA) acids is a hallmark of cancer. In fact, several lines of evidence demonstrate that increased lipid desaturation by stearoyl‐CoA desaturase (SCD1) promotes lung cancer growth. We hypothesize that increased intracellular UFA, such as oleate (OA), promotes cancer cell growth by reducing cancer associated inflammation. To test this hypothesis we evaluated the effect of OA and inhibition of OA synthesis on proinflammatory High Mobility Group Box Protein 1 (HMGB1). Decreasing OA synthesis reduced intracellular HMGB1 expression, but increased its release from cells. Given our data, alterations in OA levels appear to have a substantial effect on localization of HMGB1. Further work is necessary to define the connections between SCD1, OA and HMGB1 release in lung cancer cells. This knowledge will provide insight into how fat regulates cancer development.Support or Funding InformationThe University of Minnesota School of Medicine New Faculty Start up and College of Saint Scholastica McNair Scholars Program.