bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maresin 1: a Novel Macrophage Derived Endogenous Proresolving Inhibitor of Primary Tumor Growth and Metastasis
Authors: Lehner Kristen , Sulciner Megan , Ramon Sesquile , Mudge Dayna , Huang Sui , Serhan Charles , Panigrahy Dipak 
Published: June 2021

BackgroundChemotherapy and radiation reduce tumor burden by killing tumor cells, but as a consequence, create tumor cell debris. The debris of dead cancer cells acts as a source of tumor‐stimulation, via inflammation, on the few surviving cells contributing to tumor relapse. Thus chemotherapy may be a doubled‐edged sword. Maresin 1 (MaR1), a key mediator of inflammation resolution, is biosynthesized by human macrophages from endogenous docosahexaenoic acid. We hypothesize that maresins represent a novel modality in cancer treatment by inhibiting tumor growth and metastasis by enhancing endogenous clearance of tumor debris by macrophage phagocytosis.ResultsFlow cytometry confirmed chemotherapy and targeted therapy (tamoxifen)‐induced apoptotic tumor cell debris. MaR1 stimulated macrophage phagocytosis of chemotherapy‐induced cell debris (e.g. breast carcinoma and melanoma) by 123% to 206%. Systemic administration of MaR1 inhibits primary tumor growth by promoting the resolution of inflammation without toxicity. ConclusionsWe demonstrate for the first time that maresins inhibit primary tumor growth and metastasis via the stimulation of macrophage phagocytosis of chemotherapy‐induced tumor cell debris. Thus, the MaR1 pathway or the enhancement of endogenous resolution processes, offers an entirely novel approach for clearing tumor cells debris induced by conventional cancer therapy.
Comparative Studies on the Molecular and Functional Profile of Sheep Mucosal Derived Enoxaparin
Authors: Abro Schuharazad , Iqbal Omer , Kahn Daniel , Syed Daneyal , Hoppensteadt Debra , Yao Yiming , Jin Yong Sheng , Fareed Jawed 
Published: June 2021

Enoxaparin is a Low Molecular weight heparin which is derived from Porcine mucosal tissues. Enoxaparins derived from Bovine and Sheep Mucosal heparin have become available. This study compared 3 sheep enoxaparin preparations with varying amounts of anhydromanno contents with branded enoxaparin in routinely carried out biological assays.Enoxaparins of sheep origin were obtained from Ronssi Pharmaceuticals China, Branded enoxaparin was obtained commercially. Normal human plasma was supplemented with each of these agents individually to obtained final concentrations of 0‐10ug/mL to profile the anticoagulant and anti‐protease activities. Protamine neutralization studies were carried out. HIT antibody mediated platelet aggregation studies were also carried out.The molecular profile of the individual sheep enoxaprins irrespective of the anhydromanno component was comparable to branded enoxaparins (4.1‐4.3kDA vs 4.2kDA). In the global tests such as the aPTT, Heptest and Thrombin time both the branded and sheep heparin provide comparable results. Similarly in the protamine neutralization comparable neutralization profiles were noted in different tests. In the Anti‐xa assay the relative potency for the sheep enoxaparin (98‐104U/mg) compare to branded (99U/mg). In the HIT studies all agents exhibited comparable responses.These results indicate that the sheep mucosal heparin derived enoxaparin exhibit comparable molecular profile and biological activities in the laboratory assays. Based on these studies it is concluded the sheep mucosal heparin is comparable to porcine mucosal heparin derived enoxaparin.
Effects of Isoflurane on Dopamine Synaptic Vesicle Exocytosis
Authors: Bonvicino Christina , Zhou Zhenyu , Hemmings Hugh 
Published: June 2021

Although volatile anesthetics are extensively used in clinical medicine and animal research, their exact mechanism of action is not completely understood. Previous results from our laboratory show that isoflurane, a commonly used volatile anesthetic, attenuates synaptic transmission by differentially inhibiting synaptic vesicle exocytosis. Most research has been focused on glutamatergic and GABAergic neurons, while little is known of other types of neurons. Dopaminergic neurons play important roles in cognition, attention, reward, and movement, and have been implicated in emergence from anesthesia. Here we test the hypothesis that isoflurane inhibits synaptic dopamine release. Live‐cell imaging of cultured rat dopaminergic neurons were used to study action potential‐evoked exocytosis and Ca2+ influx measured by using optical methods. Neurons were transfected with a pH‐sensitive variant of GFP (pHluorin) fused to the luminal domain of the vesicular monoamine transporter (vMAT) to monitor exocytosis, or were treated with the cell permeant calcium indicator Fluo‐5F. The roles of specific Na+ and Ca2+ channel subtypes mediating the inhibition of Ca2+ influx and exocytosis are assessed using both pharmacological and genetic approaches for comparison to the effects on other synaptic vesicle phenotypes. Preliminary evidence indicates that clinical concentrations of isoflurane reduce Ca2+ influx and synaptic vesicle exocytosis. The goal of this work is to discern the molecular targets for the inhibitory effects of isoflurane on synaptic vesicle exocytosis and to elucidate additional presynaptic mechanisms of anesthetic action.Research supported by grant GM 58055
Comparison of Opioid Antagonist Modulation of Buprenorphine‐Induced Neurochemical Changes
Authors: Eyerman David , Li Wen‐I , Cunningham Jacobi , Dean Reginald , Deaver Daniel 
Published: June 2021

ObjectiveEvaluate differences in onset and duration of action of µ‐opioid antagonists on buprenorphine (BUP)‐induced elevations of nucleus accumbens shell (NAc‐sh) neurotransmitters.Methods: Studies utilized male Wistar rats (275 ‐ 375g) with microdialysis probes inserted into the NAc‐sh (A/P +1.70; M/L ±0.8; D/V ‐7.8 from bregma). Bioanalytical analyses of dopamine (DA) and its metabolites 3,4‐dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were performed using HPLC‐EC. Data were converted to percent change from baseline and analyzed using a repeated measures two‐way ANOVA and mechanistic pharmacodynamic modeling.Results: BUP (0.1 mg/kg) elevated extracellular concentrations of DA, DOPAC and HVA in the NAc‐sh for approximately 20 hours after subcutaneous administration. Co‐administration of either samidorphan (SAM) or naltrexone (NTX) (0.3 ‐ 3.0 mg/kg) dose dependently attenuated BUP‐induced dopaminergic activity. However, the temporal pattern of this attenuation was different for NTX and SAM. NTX displayed a rapid Kon and Koff resulting in an immediate but short‐lived (~4 hours) attenuation of BUP's effects. SAM displayed a longer Kon and Koff resulting in a protracted but longer‐lasting (~8‐10 hours) attenuation of BUP's effects.ConclusionsDifferences observed between SAM and NTX in onset and duration of action were not predicted by in‐vitro pharmacology or pharmacokinetic profiles. Importantly, the duration of action reported previously in humans for both antagonists is much longer than in rats. These data illustrate the importance of understanding the duration of action when assessing the activity of different opioid antagonists in nonclinical models.
Differential Activity of Decynium‐22 Analogs: Novel Targets for Probing Low‐Affinity/High‐Capacity Biogenic Amine Transporters
Authors: Fraser Rheaclare , Owens W Anthony , Wyatt Naomi , Krause‐Heuer Anwen , Greguric Ivan , Callaghan Paul , Fraser Benjamin , Daws Lynette 
Published: June 2021

We study neurotransmitter clearance by low‐affinity, high‐capacity uptake‐2 transporters. This family includes plasma membrane monoamine transporter (PMAT) and three organic cation transporter isoforms (OCT1‐3). We have shown uptake‐2 transporters limit the effectiveness of the selective serotonin reuptake inhibitor (SSRI) fluvoxamine. Discerning the transporter type(s) involved is restricted by the lack of highly selective ligands. This project examines the pharmacological characteristics of novel uptake‐2 compounds.Activity of ANSTO analogs, structurally based on the non‐selective inhibitor decynium 22 (D22), was tested in human OCT3‐HEK cells. Ligand competitions of [3H]MPP+ uptake were measured in whole, attached cells. Compared to D22, dose‐responses of ANSTO compounds shifted 1‐ or 2 log‐rightward, indicating reduced potency to inhibit OCT3 mediated [3H]MPP+ uptake. ANSTO analogs displayed similar potencies to corticosterone and may have higher selectivity at alternate uptake 2 subtypes.

[3H]MPP+ Uptake Competition in hOCT3‐HEK Cells

COMPOUNDS
IC50 (µM)

ANSTO 301
3.9

ANSTO 302
2.5

ANSTO 303
0.76

ANSTO 304
0.71

ANSTO 305
0.41

ANSTO 306
0.71

ANSTO 307
1.2

Corticosterone
1.3

Decynium 22
0.072

Analyses in PMAT over‐expressing cells are ongoing. Analogs and SSRI competitions will be measured in brain preparations from OCT3 knockout & PMAT knockout mice for physiological comparisons to our findings in cells. These studies will reveal more about the pharmacological profile of these novel compounds for their potential therapeutic application to treat disorders with neurotransmitter dysregulation, such as depression and drug abuse.Supported by NIH MH093320 and NRSA T32DA031115.
Idiosyncratic Drug‐Induced Liver Injury Potential of Zileuton is Detected in Diversity Outbred Mice
Authors: Harrill Alison , Lyn‐cook Lascelles , Gatti Daniel , Luo Shaoke , Churchill Gary 
Published: June 2021

Zileuton is an orally active inhibitor of 5‐lipoxygenase used clinically for maintenance treatment of asthma. While also a promising candidate for other inflammatory diseases involving leukotrienes, such as rheumatoid arthritis and inflammatory bowel disease, enthusiasm for expanding its indications is tempered by rare instances of associated drug‐induced liver injury (DILI). Mechanistic understanding of zileuton DILI is hampered by the rarity of the cases and lack of an animal model. A promising model for rare liver injury is the Diversity Outbred (DO) mouse population, which contains genetic variation that is similar to that found in humans. We hypothesized that zileuton DILI could be mediated by rare genetic alleles that are harbored by sensitive patients and thus used the DO mice as a surrogate model for clinical populations. Female DO mice (N=50/group) were orally administered zileuton (300 mg/kg) or vehicle for seven days. Significant elevations in alanine aminotransferase (ALT) were elicited by zileuton (P<0.05), but not the vehicle. Sensitive and resistant individuals were observed in the zileuton group with ALT elevations ranging from 0.2‐13.6 fold over baseline. Group mean±SEM for the zileuton and vehicle groups were 123.8±10.0 U/L and 32.39±5.4 U/L, respectively. MiR‐122 elevations in plasma confirmed the liver origin of the ALT release (P<0.05). The data provide an important first step to identifying the DO as an animal model for idiosyncratic DILI due to zileuton.This work is supported by the Burroughs Wellcome Fund, Arkansas Biosciences Institute, NIH [TRI UL1TR000039 and T32 GM106999].
Oligomerization of Equilibrative Nucleoside Transporter 1
Authors: Cravetchi Xenia , Vilas Gonzalo , Hammond James 
Published: June 2021

Equilibrative nucleoside transporter 1 (ENT1) is a ubiquitously expressed membrane transporter in mammalian cells responsible for the transmembrane flux of endogenous nucleosides such as adenosine, as well as, chemotherapeutic, anti‐vial, and anti‐parasitic nucleoside analogues. The present study was designed to assess whether ENT1, like many other solute transporters, functions as a dimer or higher order oligomer.Previous functional studies from our laboratory suggested the presence of two populations of ENT1 with differential sensitivities to sulfhydryl reagents at the plasma membrane. Studies of ENT1 photoaffinity labelled membranes revealed multiple molecular mass bands on denaturing gels. Non‐denaturing Blue Native PAGE resulted in a molecular mass of ENT1 of 137 kDa (versus 55kDa monomer) suggesting a higher order oligomer or association with other proteins. Co‐immunoprecipitation studies on HEK293 cells expressing MYC‐ and HA‐hENT1 indicated that hENT1 can oligomerize. This was confirmed by immunofluorescence experiments, which showed a 1.5‐fold increase in colocalization of MYC‐hENT1 and HA‐hENT1 signal when the amount of transfected HA‐hENT1 cDNA was gradually increased while MYC‐hENT1 was kept constant in HEK293 cells. Finally, proximity ligation assays, performed on WT‐hENT1‐PK15 cells transiently transfected with MYC‐hENT1, showed interaction between the two pools of hENT1.These data support the hypothesis that ENT1 exists in the plasma membrane as a dimer, and possibly higher level protein complexes. Further work regarding the identity of the ENT1 complex components as well as the impact of these interactions on the function and inhibitor/substrate association with ENT1 remains to be determined.Supported by the Natural Science and Engineering Research Council of Canada.
High Fructose Consumption Exacerbates Metabolic Alterations Compared to Glucose in Female Rats.
Authors: Sangüesa Gemma , Shaligram Sonali , Akther Farjana , Rahimian Roshanak , Alegret Marta , Laguna Juan 
Published: June 2021

High fructose consumption, especially in soft drinks, has been associated with the development of obesity, diabetes and hypertension. The aim of this study was to investigate the effect of liquid fructose and glucose intake on metabolic parameters related to these pathologies in female rats.Sprague‐Dawley female rats were supplemented with 20% w/v glucose (G) or fructose (F) in drinking water for 8 weeks. Control (C) rats received no sugar. Body weight, food and drink intake and blood pressure (BP) were monitored throughout the experiment, and after the sacrifice, organ weight and plasma analytes for metabolic parameters were measured.Total caloric intake was significantly increased 1.8‐fold and 1.6‐fold in G and F groups vs C, respectively. Moreover, calorie consumption was significantly higher in G vs F group (p<0.01). Systolic BP was significantly increased in both G and F groups. Adiposity and plasma leptin levels were also significantly higher in treated groups vs C. However, total body and liver weights, as well as triglyceride (TG) and insulin levels were significantly increased only in F group. Interestingly, plasma adiponectin levels were increased by 3‐fold only in G group (p<0.001 vs F and C).In conclusion, despite the higher total caloric consumption in G group, F but not G intake increased insulin and TG levels suggesting insulin resistance. The paradoxical increase in adiponectin levels only in G group might be a mechanism of protection from metabolic alterations.Supported by NIDCR and F. Pedro i Pons.
Progression of Cancer Cachexia Alters Muscle Lactate Metabolism In ApcMin/+ Mice
Authors: Brown Lemuel , Brown Jacob , Rosa Megan , Lee David , Perry Richard , Hardee Justin , Carson James , Greene Nicholas , Washington Tyrone 
Published: June 2021

Roughly 100,000 individuals are diagnosed with colorectal cancer a year, 80% of these cases arise from adenomatous polyps. A mutation of the tumor suppressor gene, Adenomatous polyposis coli (Apc) results in multiple intestinal neoplasia (Min), thus the Apc (Min/+) mouse is a common colorectal cancer model. Cancer cells favor a highly glycolytic environment. As such, there is an induction of processes regulating lactate metabolism and lactate shuttling. How colorectal cancer influences skeletal muscle lactate metabolism is uncertain. Purpose: We investigated how muscle lactate metabolism is regulated during the progression of cancer cachexia in Apc (Min/+) mice. Methods: Male Min/+mice (n = 17) were classified by body mass loss: weight stable (WS, 蠄 5%, n = 5), and cachectic (CC, 6‐19%; n = 5). C57BL/6J (B6, n = 6) served as controls. Quadriceps muscle samples were extracted and real‐time PCR was conducted to quantify lactate‐related gene expression. Results: LDH‐A was reduced 47% in the CC mice compared to the WS mice (p < 0.05), while LDH‐B was not changed with cancer cachexia progression (p = 0.09). Monocarboxylate transporter 1 (MCT1) was induced 1.9‐fold in CC mice (p < 0.05) compared to the B6 mice. MCT4 was induced 1.7‐fold and 2.3‐fold in the CC mice compared to B6 and WS mice, respectively. Muscle CD147 was not changed with cancer cachexia progression (p = 0.31).ConclusionThe progression of cachexia in mice with colon cancer alters markers of lactate metabolism that may play a role in muscle wasting associated with cachexia.
Cerebral Blood Flow Velocity Responses to an Acute Cognitive Challenge in Healthy Adults
Authors: Barnes Jill , Harvey Ronee , Malterer Katherine , Johnson Maja , Joyner Michael 
Published: June 2021

Cerebral blood flow velocity responses to hypercapnia are blunted by the cyclooxygenase inhibitor indomethacin (INDO). We hypothesized that INDO would also attenuate middle cerebral artery blood flow velocity (MCAv) responses to an acute cognitive challenge. We evaluated the MCAv responses to an acute cognitive challenge in 20 healthy young (20‐35 yrs) and older (56‐76 yrs) healthy adults, including 10 men and 10 women before and 90 minutes after INDO administration. The cognitive challenge consisted of 2 blocks of the Stroop color word test: easy (3 colors) and difficult (8 colors). Mean arterial pressure (MAP), end‐tidal CO2, and MCAv were monitored throughout the protocol. There were no differences in MAP or end tidal CO2 between trials. Indeed, MCAv was lower during INDO than baseline for both the easy (50±4 vs. 68±4 cm/s; p<0.01) and difficult (49±3 vs. 66±3 cm/s; p<0.001) cognitive challenges. Additionally, there was an Age x Sex interaction for the increase in MCAv during the easy cognitive task, with older men having a greater increase than older women (15±5 vs. ‐1±5%, respectively; p<0.05). This interaction was not statistically significant for the difficult cognitive task or during the INDO trial. In conclusion, similar to hypercapnia, the cyclooxygenase inhibitor INDO blunts cerebral blood flow velocity responses to an acute cognitive challenge.Funded by NIH grant HL 118154
Chronic Hypoxia Modulates Endothelial Influences on Smooth Muscle Phenotype in Fetal Cerebral Arteries
Authors: Hubbell Margaret , Kim Dahlim , Thorpe Richard , Silpanisong Jinjutha , Pearce William 
Published: June 2021

This study explores the hypothesis that chronic hypoxia modulates endothelial regulation of smooth muscle phenotype and function in fetal cerebral arteries. Endothelium denuded and intact middle cerebral arteries harvested from term fetuses from ewes kept at sea level (Normoxic) or 3, 820 m (Hypoxic) altitudes for the last 110 days of gestation were assessed for contractile function and smooth muscle phenotype as quantified by changes in the colocalization of Non‐Muscle (NM) and Smooth Muscle (SM) Myosin Heavy Chain (MHC) with Smooth Muscle alpha‐actin (SM‐αA). Chronic hypoxia reduced maximum myogenic stress, but increased maximum K+‐induced stress. Organ culture of arteries from normoxic animals with VEGF reproduced this increase in K+‐induced stress but only in the presence of an intact endothelium. For NM‐MHC/AA colocalization, an index of synthetic smooth muscle, organ culture for normoxic arteries with VEGF had little effect in the absence of endothelium but in the presence of endothelium enhanced colocalization. This effect of the endothelium on NM‐MHC/AA colocalization was enhanced in hypoxic arteries. For SM‐MHC/AA colocalization, a marker for contractile smooth muscle, organ culture of normoxic arteries with VEGF had little effect in the presence or the absence of endothelium, but in hypoxic arteries endothelium dramatically amplified VEGF‐induced increases in colocalization. These results demonstrate that chronic hypoxia modulates VEGF‐dependent endothelial regulation of smooth muscle phenotype in fetal cerebral arteries.This work was supported by National Institutes of Health Grants HL‐54120, HD‐31266, HL‐64867, and NS‐076945 and the Loma Linda University School of Medicine.
Depressed Sarcoplasmic Reticulum Activity Underlies Ca2+ Dyshomeostasis in A Rat Model of Metabolic Syndrome
Authors: OKATAN ESMA , TUNCAY ERKAN , TURAN Belma 
Published: June 2021

High‐carbohydrate diet‐induced obesity and/or metabolic syndrom (MetS) is recognized as an independent risk factor for dysfunctioning of the heart. Although several mechanisms have been postulated for its identification, no precise mechanism is available yet for the cardiac remodeling and contractile dysfunction under MetS. Therefore, we aimed to investigate the role of sarcoplasmic reticulum (SR) on altered intracellular Ca2+ regulation in cardiomyocytes from MetS male rats, induced with high‐sucrose drinking water during 16‐week period. Basically, electrically‐stimulated Ca2+ transients and L‐type Ca2+‐currents (LTCC) were recorded in ventricular myocytes from MetS rats relative to myocytes from control rats. We also investigated SR‐Ca2+‐ATPase (SERCA) activity as well as phosphorylation levels of cardiac ryanodine receptor (RyR2) family proteins by Western blot analysis. The Ca2+ transients exhibited significantly reduced amplitude (~30%), and prolonged time courses (2‐fold) with no change in LTCC as well as depressed Ca2+ loading of SR (~55%) due to caffeine responses in cardiomyoctes from MetS rats with increased basal Ca2+ compared to aged‐matched control rats. Our data with caffeine responses under 0Na0Ca also demonstrated a depressed SERCA activity in MetS cardiomyocytes which supported further the data on a slowed cytosolic Ca2+ removal associated with a significant decrease in SERCA2‐mediated Ca2+ reuptake. Additionally, the data with tetracaine application assay was supporting a leaky‐RyR2 in cardiomyocytes from MetS group. Moreover, high phosphorylation levels of both RyR2 and phospholamban are supporting a depressed SR activity which underlies Ca2+ dyshomeostasis in MetS rat model.(Supported by TUBITAK‐SBAG‐111S042)
Palmitic Acid Regulation of Cardiac Inotropy and Calcium Handling in Healthy and Angiotensin II‐Induced Hypertensive Rat
Authors: Jin Chun Li , Zhang Yin Hua 
Published: June 2021

Background and aimPalmitic acid (PA) is a predominant metabolic substrate. However, the effect of PA on cardiac contraction and underlying mechanisms in healthy and diseased heart remain unclear. Here, we analyzed PA‐regulation of myocyte contraction in left ventricular (LV) myocytes from sham and angiotensin II (Ang II)‐induced hypertensive rats.ResultsOur results showed that PA (100 μM) increased the amplitude of sarcomere shortening in LV myocytes (field stimulation, 2Hz,IonOptix Corp) from shams but not in hypertension. PA increased intracellular ATP level in shams.In contrast, etomoxir, a selective carnitine palmitoyl transferase I inhibitor, blunted the positive inotropic effect of PA, suggesting that increased beta‐oxidation may be fundamentally importantin PA‐regulation of cardiac inotropy. Mechanistically, PA did not increase the amplitude of Ca2+ transients or the density of peak L‐type Ca2+ current (ICa) or Na+‐Ca2+ exchanger activity, INCX, in either group. Paradoxically, PA did not affect the amplitude of Ca2+ transient or myofilament Ca2+ sensitivity (Myo‐Ca‐Sen) in shams. In hypertension, PA did not affect myocyte contraction or Ca2+ transient amplitude. Reactive oxygen species (ROS) scavenger did not affect PA‐induced increase in LV myocyte contraction in sham or hypertension.PA reduced neuronal nitric oxide synthase (nNOS) production of NO in shams but increased nNOS production of NO in hypertension. Importantly, nNOS inhibition with S‐methyl‐l‐thiocitrulline (SMTC) increased the amplitude of Ca2+ transients and restored PA‐induced cardiac inotropy in hypertension.ConclusionPA increases myocardial ATP production and potentiates LV myocyte contraction in healthy heart. nNOS restricts PA‐dependent cardiac inotropy by modulating Ca2+ handling in hypertension.