bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological and Pharmacological Profiling of Pentosan Polysulfate (PPS) in Comparison to Heparin and its Relative Neutralization by Protamine Sulfate
Authors: Venkitasubramony Vishnu , Polisky Anna , Siddiqui Fakiha , Kouta Ahmed , Fareed Jawed , Hoppensteadt Debra , Iqbal Omer , Laddu Atul , Jeske Walter 
Published: April 2020

BackgroundPentosan Polysulfate has traditionally been used to treat patients with Interstitial Cystitis and more recently osteoarthritis, cancer, HIV and prion disease. Such widespread clinical application of PPS and the active search for new effective alternatives to traditional heparin compels a comprehensive investigation of the effect of PPS batches on anticoagulation in comparison to Heparin. The purpose of this study is to create a comprehensive profile and comparison of new PPS batches (L‐15, L‐19, L20 and Ba), old PPS batch (PPS Ba), and Heparin. Furthermore, the feasibility of protamine sulfate as a neutralizing agent to reverse the anticoagulant effects of PPS is investigated.Materials and MethodsVarious batches of PPS at 1 mg/ml were prepared in saline. For whole blood clotting profile, thromboelastography (TEG) was carried from 2.5 – 5.0 ug/ml and activated clotting time (ACT) at 25ug/mL. Clotting profile in whole blood, retrieved plasma and supplementation in normal human pooled plasma (NHP) were carried out at 100 – 0.0 ug/ml by using anticoagulant assays. Amydolytic methods were used to measure anti‐Xa/ IIa effects. Thrombin generation inhibition studies (TGA) were carried out in NHP from 100 ‐ 0.0 ug/ml. Heparin supplementation and protamine sulfate neutralization in NHP from 10 ‐0 ug/mL were compared to PPS batches in a logarithmic scale.ResultsAll drugs produced a concentration dependent effect. Similar effects in anticoagulation assays were noted except anti‐Xa assay. In TEG, significant viscoelastic changes were observed at 5ug/mL. Prolongation of ACT was observed at 25ug/mL. No significant differences were noted in between batches of PPS in TEG and ACT studies. In TGA, concentration dependent but no significant difference in between the batches were noted. Neutralization of protamine sulfate was observed up to 12.5 ug/mL in anticoagulant assays and marginal effect on anti‐protease assays. Lastly, logarithmic comparison of the protamine sulfate neutralization indicated that protamine sulfate is a weaker neutralizing agent of PPS compared to heparin.ConclusionThese studies suggest that multiple batches of PPS have a similar anticoagulant profile. In comparison to heparin, PPS presents itself as a 10‐fold weaker anticoagulant alternative for use in a variety of clinical applications. Neutralization of PPS at low concentrations by protamine sulfate in anticoagulant assays warrants further investigation on an effective neutralizing concentration for clinical use.
The Genome‐wide Landscape of Oxidative Base Damage in Hypoxia; Potential Role in Metabolic Reprogramming in Chronic Lung Disease
Authors: Daly Grant , Houserova Dominika , Francis Christopher Michael , Andrews Joel , Langley Raymond J. , Pastukh Viktor M. , Bass Hank W. , Borchert Glen M. , Gillespie Mark N. 
Published: April 2020

Hypoxia, a common attribute of many lung diseases, causes an adaptive response characterized by glycolytic reprogramming, which is initiated in part by the master transcriptional regulator, Hif‐1, accumulating in response to reactive oxygen species (ROS) generated as second messengers in hypoxic signaling. ROS produced in hypoxia also appear to engage a DNA damage and repair pathway in promoter regulatory elements that impacts core events in transcription (Pastukh, et al., 2015). Because the genome‐wide disposition of base damage in hypoxia could provide clues about mechanisms of persistent metabolic reprogramming in the lung, we executed a proof‐of‐concept study to define the landscape of the common base oxidation product 8‐oxoguanine (8‐oxoG) in the genomes of normoxic and acutely hypoxic human umbilical vein endothelial cells (HUVECs), focusing on localization of base damage within genes comprising the hypoxic transcriptome. Using ChIP‐seq analysis to delineate sequences harboring 8‐oxoG, we found that base damage was enriched in multiple regulatory regions, including those defined by transcription factor binding motifs and epigenetic marks. Of particular interest, base damage in these regions occurred in distinctly different genes in normoxic and hypoxic cells. SIM super‐resolution immunofluorescence microscopy revealed prominent base damage in facultative heterochromatin residing in close proximity to chromatin‐free channels that appeared to be in direct communication with the nuclear membrane. A comparison of sequences demarcated by 8‐oxoG ChIP‐seq signals to the RNA‐seq‐defined hypoxic transcriptome revealed that base damage was prominent in genes occupying regulatory nodes in pathways controlling the metabolic response to hypoxia as well as other key adaptive pathways. Finally, after noting that sequences harboring 8‐oxoG displayed elevated variant densities, we discovered that a high proportion of these variants were likely mutational artifacts since they were corrected by enzymatic excision of damaged bases in template DNA prior to PCR‐based sequencing library preparation. Collectively, these findings suggest that hypoxia fundamentally alters the genomic landscape of 8‐oxoG in HUVECs, causing accumulation or dissipation of the base oxidation product in non‐coding regulatory regions in differentially‐transcribed genes. The presence of base damage‐associated mutational artifacts supports the concept that the DNA damage and repair pathway engaged during hypoxic transcriptional signaling could impose a mutagenic threat leading to formation of permanent and currently uncharacterized somatic variants with the potential to drive persistent metabolic dysregulation in hypoxia‐related lung diseases.Support or Funding InformationNIH
Nix induced mitochondrial fission and mitophagy inhibits myocyte insulin signaling through mTOR and p70S6 kinase
Authors: Gordon Joseph W. , da Silva Rosa Simone Cristina , Field Jared T. , Martens Matthew D. , West Adrian R. , Aliani Michel , Dolinsky Vernon W. 
Published: April 2020

Lipotoxicity is a form of cellular stress caused by the accumulation of lipids resulting in mitochondrial dysfunction and insulin resistance in muscle. Previously, we demonstrated that the mitophagy receptor Nix is responsive to lipotoxicity and accumulates in response to diacylglycerols induced by high‐fat (HF) feeding. In addition, previous studies have implicated autophagy and mitophagy in muscle insulin sensitivity. To provide a better understanding of these observations, we undertook gene expression array and shot‐gun metabolomics studies in soleus muscle from rodents on an HF diet. Interestingly, we observed a modest reduction in several autophagy‐related genes including Beclin‐1, ATG3, and ‐5. Moreover, we observed alterations in the fatty acyl composition of cardiolipins and phosphatidic acids. Given the previously reported roles of these phospholipids and Nix in mitochondrial dynamics, we investigated aberrant mitochondrial fission and turn‐over as a mechanism of myocyte insulin resistance. In a series of gain‐of‐function and loss‐of‐function experiments in rodent and human myotubes, we demonstrate that Nix accumulation triggers mitochondrial depolarization, fragmentation, calcium‐dependent activation of DRP1, and mitophagy. In addition, Nix‐induced mitochondrial fission leads to myotube insulin resistance through activation of mTOR‐p70S6 kinase and inhibition of IRS1, which is contingent on phosphatidic acids and Rheb1. These findings provide insight into the role of Nix‐induced mitophagy and myocyte insulin resistance during an overfed state when overall autophagy‐related gene expression is reduced.Support or Funding InformationFunded by Research Manitoba, the Children’s Hospital Research Institute of Manitoba, and the Diabetes Research Envisioned and Accomplish in Manitoba (DREAM) theme.
Negative Modulation of α4β2* Nicotinic Acetylcholine Receptors During Postnatal Maturation of the Mouse Prefrontal Cortex
Authors: Hewitson Elizabeth M. , Bailey Craig D. C. 
Published: April 2020

Acetylcholine (ACh) signalling within the medial prefrontal cortex (mPFC) is important for the normal development and function of prefrontal cognitive networks. Layer VI of the mPFC is highly populated with pyramidal neurons that express the α4β2* subtype of nicotinic acetylcholine receptor (nAChR), and the activation of these receptors by ACh is central to its function in this region. These receptors can be negatively modulated through several forms of inhibition. For example, nicotine potently desensitizes nAChRs to ACh activation, while the endogenous progesterone‐derived neurosteroid 3α‐hydroxy‐5α‐prenan‐20‐one (allopregnanolone; ALLO) inhibits nAChR activation by ACh through a presumed negative allosteric modulation. Both forms of inhibition mediated by nicotine and ALLO have been demonstrated for α4β2* nAChRs located on mPFC layer VI neurons in young postnatal mice. However, the relative strength for both forms of inhibition in mature mice, compared with the young postnatal age, is not clear. In addition, the mechanism of action for ALLO inhibition of α4β2* nAChRs is not well understood. Using whole‐cell electrophysiology, we measured the ability of both nicotine (300 nM) and ALLO (10 μM) to inhibit 1 mM ACh activation of α4β2* nAChRs located on mPFC layer VI neurons from male and female CD1‐strain mice at postnatal day (P)15‐20 (young postnatal age) and P80‐120 (adulthood). For nicotine, nAChR desensitization was greater at P15‐20 than at P80‐120, and this result was driven by an effect of postnatal age in male mice only. Conversely, ALLO inhibited nAChR function to a similar degree at both P15‐20 and P80‐120. Ongoing ACh binding experiments aim to determine the mechanism of action for ALLO inhibition of these receptors at both ages. Results from this study confirm that the endogenous neurosteroid ALLO inhibits mPFC α4β2* nAChRs in adulthood as it does in young postnatal life. Developmental changes to the magnitude of nicotine desensitization but not ALLO inhibition suggests that different factors regulate each type of negative modulation at α4β2* nAChRs, and that these factors are differentially altered during postnatal maturation of the mPFC.Support or Funding InformationNatural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant 2019‐04989 to CDCB
Effect of an individualized food‐based nutritional intervention on serum vitamin A, E, and carotenoids concentrations in recently diagnosed breast cancer patients
Authors: Prado Jessica Avila , Salcido-Sauceda Diana G. , Limon Miro Ana T. , Pacheco Moreno Bertha I. , Garcia Humberto Astiazaran , Teros Veronica Lopez 
Published: April 2020

Breast cancer (BC) is the most common type of neoplasm among Mexican women. The antineoplastic treatment can affect the patient’s nutritional status; especially micronutrients, such as retinol, carotenoids and α‐tocopherol. The objective was to evaluate the effect of a food‐based individualized nutrition intervention on the retinol, carotenoid and α‐tocopherol serum concentrations of recently diagnosed BC patients, at baseline and 6mo after the intervention. This is a pretest‐posttest study in women with a recent diagnosis of invasive ductal/lobular carcinoma of the breast (clinical stage I–III). The individualized nutrition intervention was developed upon the nutritional assessment of participating women; adjusting the dietary plan on their total energy expenditure, and following the WCRF/AICR guidelines, adapting 1.5 g/kg/d of protein intake, 5–9 servings of fruits and vegetables and a caloric restriction (500–1000 kcal/d) when applicable (BMI ≥25 kg/m2). Baseline and final measurements include anthropometry, body composition by dual x‐ray absorptiometry, 24‐hour dietary recall, and the assessment of retinol, carotenoids and α‐tocopherol serum concentrations. Nineteen women between 33 and 68 years completed the intervention. At the time of diagnosis, 74% of the women were overweight or obese, and serum retinol was <1.05 μmol/L in 42% (n=8). After the 6‐month nutritional intervention, BC patients decreased an average of 2.67 kg of body weight (p <0.001), and lost ~2 kg of body fat (p<0.01). After the intervention, serum retinol increased +0.83 μmol/L (p<0.001) and α‐tocopherol increased +1.89 μmol/L (p<0.02) increased, which was positively correlated with a dietary increase of these micronutrients (p<0.05). No difference was found for provitamin A carotenoids or xantophils (β‐carotene, α‐carotene, β‐cryptoxanthin, lutein, zeaxanthin and lycopene) (p>0.05). The implementation of an individualized nutritional intervention before and during antineoplastic treatment prevents the nutritional deterioration of BC patients. This trial was registered at clinicaltrials.gov as NCT03625635.Support or Funding InformationJAP and ATLM, received a fellowship from the National Research Council (CONACyT).
Sex‐selective Effects of MCH Antagonism on Metabolic Hormones
Authors: Gilman Lee , Beaver Jasmin N. , Vasquez Erin , Bowman Melodi A. , Vitela Melissa , Daws Lynette C. 
Published: April 2020

Melanin‐concentrating hormone (MCH) is a neuroactive peptide that influences eating and emotional behaviors, as well as insulin sensitivity and adiposity. The vast majority of MCH research has focused only on males. Further, how endogenous levels of MCH parallel metabolic and behavioral measures over time, or are affected by diet, has not previously been investigated. We evaluated how endogenous MCH changes, as a function of sex, in adult rats as they consumed either a control diet alone, or a control diet supplemented with a high fat/high sugar (i.e., “Western”) diet. During the final week of this 8 week dietary manipulation period, rats received daily injections of the MCH receptor 1 antagonist GW803430 (3 mg/kg) or vehicle (1 mL/kg). Weekly blood sampling for the duration of the diet manipulation allowed for measurement of circulating MCH, insulin, leptin, and glucose levels. Surprisingly, we noted that GW803430 significantly reduced endogenous MCH levels only in males consuming control diet. Endogenous insulin levels were also dramatically lowered in males receiving GW803430, independent of diet condition. Though female rats did not exhibit these hormonal changes in response to drug, they did exhibit diet‐ and drug‐specific emotional behavior responses in the forced swim test that mapped on to endogenous MCH levels. Ongoing analyses are examining leptin levels, food consumption, and hepatic steatosis in relation to endogenous MCH. To our knowledge, these are the first investigations into how MCH receptor 1 antagonism affects circulating metabolic hormones, and into how this drug affects emotional behavior in females. To confirm involvement of the MCH receptor 1 in these sex‐selective hormonal reductions and behavioral effects, future experiments will employ a different MCH receptor 1 antagonist.Support or Funding InformationThis work was supported by a Morrison Trust grant to LCD, a NARSAD Young Investigator Award from the Brain & Behavior Research Foundation and Vital Projects Fund, Inc. to TLG, and National Institutes of Health grants 1R01 MH106978 and R21 DA046044 to LCD.
Exposure to Environmental Pollutant Benzo[a]pyrene Exacerbates Skin Inflammation in a Mouse Psoriatic Model
Authors: Klein Joshua Alan , Singh Satyendra K. , Goswami Dinesh G. , Braucher Leah N. , Wright Holly N. , Noland Erica L. , Agarwal Rajesh , Tewari-Singh Neera 
Published: April 2020

A rapid increase in the global prevalence of skin inflammatory diseases like psoriasis cannot be attributed to genetics alone. Environmental factors including major ubiquitous organic pollutants like polycyclic aromatic hydrocarbons (PAHs) could contribute to their pathophysiology. Benzo[a]pyrene (BaP) is one of the PAH that is generated mainly from cigarette smoke, wood‐burning, automobile exhaust etc. The molecular mechanisms that lead to inflammatory skin diseases following exposure to BaP are not well elucidated, though there are suggestions that these responses could be mediated by aryl hydrocarbon receptor (AhR), a xenobiotic sensor. To investigate the effect of BaP exposure on skin inflammation in a mouse psoriatic model, the dorsal skin of naïve C57BL/6 mice was shaved (48h prior to exposure) and exposed to 62.5mg of 5% imiquimod (IMQ) cream once daily for five days. For assessing the initiation or exacerbation of psoriasis from exposure to BaP, mice were exposed 64μg BaP in 50μl acetone for five days before IMQ application [BaP+IMQ] or for five days together with the IMQ [(BaP+IMQ)] application. Following the analysis and scoring of clinical lesions, mice were sacrificed, and skin sections were analyzed for inflammation‐related histopathological and molecular changes. BaP exposure together with IMQ exacerbated IMQ‐induced psoriatic inflammatory lesions including the skin bi‐fold thickness, epidermal and dermal thickness, hyperkeratosis, dermal fibrosis, neutrophil infiltration, neutrophil degeneration and mast cell degranulation. Molecular analysis on the skin samples to further elucidate the effect BaP on IMQ‐induced inflammatory markers such as neutrophil infiltration, macrophages, inflammatory cytokines that could exacerbate psoriasis is being carried out. In other studies, defining the role of AhR in BaP‐induced biological, molecular, and metabolic alterations in mouse skin, concomitant treatment with AhR antagonist CH‐223191 was given before BaP+IMQ treatment. The antagonist treatment before the (BaP+IMQ) treatment abrogated the BaP‐caused increase in epidermal and dermal thickness in psoriatic mice. The effect of the AhR inhibitor on other biological and molecular psoriatic parameters that are exacerbated on exposure to BaP are also being analyzed to decipher the role of AhR in BaP‐induced and/or exacerbation in inflammatory skin diseases like psoriasis.Support or Funding InformationSkaggs Scholars Program Grant, University of Colorado Denver and Start‐up Fund to Neera Tewari‐Singh, Michigan State University
Mechano‐therapy using high loads enhances regrowth of skeletal muscle in young, but induces muscle damage in old rats.
Authors: Hettinger Zachary R. , Confides Amy L. , Hamagata Kyoko , Butterfield Tim A. , Dupont-Versteegden Esther E. 
Published: April 2020

IntroductionOlder adults have an impaired ability to recover from skeletal muscle atrophy compared to young, predisposing them to loss of independence and poor quality of life. We have previously shown that mechano‐therapy in the form of cyclic, compressive loading (CCL) enhances regrowth of atrophied skeletal muscle in young adult rats, but not in old. Our preliminary data show that passive, transverse stiffness of muscles from old rats is elevated compared to young, potentially blunting the mechanical stimulus and subsequent growth response. In the current study, we hypothesized that an increased CCL load proportional to the higher tissue stiffness in old rats would enhance skeletal muscle regrowth when compared to atrophied muscles of old rats subjected to a lower load of CCL or ambulation alone.MethodsYoung (10 months; N = 6) and old (30 months; N = 6) adult male F344/Brown Norway rats underwent 14 days of hind limb suspension before being randomly assigned to one of the following: reloading for 7 days without CCL (RE); reloading with 4.5 N CCL (RE + CCL, 4.5 N); or reloading with 7.6 N CCL (RE + CCL, 7.6 N). Starting on day 0, four bouts of CCL were administered to the right gastrocnemius using a custom designed device capable of applying a precise load, with 48 hrs between bouts. Gastrocnemius muscle sections were analyzed for muscle fiber cross‐sectional area (CSA), satellite cell abundance (Pax7+/fiber), embryonic myosin heavy chain expression (eMyHC+/fiber) and centro‐nucleation using immunohistochemistry.ResultsMuscle fiber CSA was load dependent in young adult rats, but had no effect at either load in old rats. When compared to muscles from RE rats, 4.5 N CCL had no effect on satellite cell abundance regardless of age; however, satellite cell abundance was higher in both young and old adult muscle after 7.6 N CCL compared to RE with old rats having 2‐fold higher levels compared to RE. Regardless of load, CCL was not associated with differences in eMyHC expression or centrally located nuclei in young adult rat muscle, while muscles receiving 7.6 N CCL in old rats had a higher number of centrally located nuclei and were ~16‐fold higher in eMyHC+ fibers compared to RE.ConclusionsThese results show that CCL induces a load dependent anabolic response in young adult animals during muscle mass recovery following disuse, but has no regrowth effect on muscles from old animals at either load. Furthermore, using a higher CCL load, scaled for elevated transverse stiffness in aged muscle, induces damage in muscle of old but not young rats.Support or Funding InformationThis research was supported by NIH grant RO1AT009268 and R21AG042699.
Protracted Effects of Ketamine Require Immediate Kappa Opioid Receptor Activation and Long‐Lasting Desensitization
Authors: Jacobson Moriah L. , Simmons Sarah C. , Wulf Hildegard A. , Cheng Huaiyan , Feng Ying-Hong , Nugent Fereshteh S. , Browne Caroline A. , Lucki Irwin 
Published: April 2020

Ketamine produces rapid and sustained antidepressant activity, but its mechanism of action remains uncertain. Williams & colleagues (2018) reported that naltrexone pretreatment attenuated ketamine’s effects in treatment resistant depressed patients. Naltrexone antagonizes both kappa (KOR) and mu opioid receptors (MORs). We hypothesized that ketamine requires acute KOR activation, leading to long‐lasting suppression of KOR signaling to exert its antidepressant effects. The following series of experiments demonstrated: 1) exposure to ketamine produces internalization of KORs; 2) the behavioral effects of ketamine in mice were prevented by prior KOR blockade; and 3) ketamine pretreatment prevented behavioral and physiological responses caused by subsequent KOR activation.KOR internalization was tested in HEK293 cells transfected with yPET‐OPRK1 plasmids following ketamine stimulation (2 μM). Approximately 30% of KORs were internalized, which was comparable to the internalization achieved with the endogenous KOR agonist dynorphin (40 μM). To demonstrate that activation of KORs by ketamine contributes to its protracted behavioral profile, C57BL/6J mice (8–12 weeks) were pretreated with naltrexone (1 mg/kg) or the selective KOR antagonist LY2444296 (3 mg/kg) 30 minutes prior to ketamine (10 mg/kg) and were tested in the forced swim test 24 h later. Reductions in immobility scores by ketamine were blocked by naltrexone and LY2444296 pretreatment, confirming the importance of KORs in initiating ketamine’s long‐lasting effects.Next, the physiological impact of ketamine on KOR activity was examined ex vivo in the lateral habenula (LHb), a reward‐related brain region. Bath application of the KOR agonist U50,488 (10 μM) robustly increased the number of action potentials in response to depolarization. The increase in LHb neuronal excitability was absent when ketamine (10 mg/kg) was administered to mice 24 h previously. In parallel, U50,488 (10 or 20 mg/kg) induced behavioral deficits on nest building, prepulse inhibition and antinociception on the hot plate were effectively prevented by ketamine (10 or 20 mg/kg) given 24 h earlier. Finally, LY2444296 (3 mg/kg) administered 30 min prior to ketamine (10 mg/kg) prevented ketamine‐induced suppression of U50,488‐induced alterations on nesting behavior 24 h later. This established that KOR occupation prior to ketamine prevented the initiation of ketamine’s long‐lasting behavioral effects.Collectively, these studies provide evidence supporting the hypothesis that activation of KORs by acute ketamine administration leads to enduring reductions of KOR signaling, which may contribute to the protracted clinical antidepressant effects of ketamine.Support or Funding InformationThis work was funded by US Public Health Service (USPHS) grant R01 MH105623.