bluuebunny/crossref_metadata_2025_split huggingface dataset:
Urolithin A, a Product of the Microbiome, Attenuates the Palmitate‐TLR4 Inflammatory Pathway in Renal Tubule Cells
Authors: Chappell Mark , Zhu Xuewei , Pirro Nancy , Tallant Ann , Gallagher Patricia 
Published: April 2020

Obesity is a major risk factor for cardiovascular disease and chronic renal injury. Tubulointerstial inflammation may reflect increased exposure of saturated fatty acids (sFA) to the renal epithelium and activation of the toll‐like receptor 4 (TLR4). Obesity‐induced inflammation may also facilitate gut microbiome dysbiosis and potentially alter the processing of exogenous polyphenolic compounds to metabolites with enhanced protective effects. Indeed, Urolithin A, the primary product of the microbiome metabolism of ellagitanins, promotes gut barrier function and attenuates colonic inflammation. However, the role of Urolithin A to attenuate tubular injury and inflammation has not been assessed. We propose that Urolithin A has anti‐inflammatory actions in rat proximal tubule cells (PTCs) chronically exposed to the sFA palmitate.PTCs (NRK‐52e cells) were exposed to palmitate [200 μM] for a 24 hours in the presence or absence of Urolithin A [50 μM], the TLR4 inhibitor TAK242 [1 μM], the EGFR inhibitor AG1478 [1 μM] and cSRC kinase inhibitor Dasatinib [10 μM] as both EGFR and cSRC may be integral to TLR4 activation. Cytokine expression in the PTCs was quantified by separate ELISAs.Palmitate exposure stimulated the robust release of PAI‐1 6‐fold [4.3 ± 0.3 vs. 24.2 ± 0.4 ng/ml; P<0.001, n=3], CCL2 150‐fold [0.04 ± 0.01 vs. 6.2 ± 0.4 ng/ml; P<0.001, n=3] and CCL5 10‐fold [23.4 ± 0.1 vs. 255 ± 11 pg/ml; P<0.001, n=3]. The TLR4 inhibitor abolished the increase in CCL2 and CCL5, and markedly attenuated PAI‐1 release [70%, P<0.01]. The EGFR inhibitor partially inhibited all three cytokines [40–50%, P<0.01] while the cSRC inhibitor abolished PAI‐1 and partially inhibited CCL5, but failed to inhibit CCL2 release. Urolithin A essentially abolished the increase in PAI‐1 and CCL5, and markedly inhibited CCL2 release to palmitate [70%, P<0.01].We conclude that Urolithin A may be renoprotective in obesity‐induced injury by targeting activation of TLR4 within the renal epithelium to attenuate the cytokine release. Moreover, a deficit in the microbiome‐dependent generation of Urolithin A may potentially promote renal inflammation.Support or Funding InformationChronic Disease Research Fund, AHA Transformative Grant 18TPA34170522; NIH R01HL146818, the Farley Hudson Foundation, the Hypertension & Vascular Research Center
Impact of Maternal Obesogenic Diet on Offspring Bile Acid Homeostasis and Disease Progression in Non‐Alcoholic Fatty Liver Disease is Transmitted to Next Generation by Male Offspring
Authors: Thompson Michael D. , Cowen Jamie , Hinrichs Holly , Derse Alaina , Ferey Jeremie , Moley Kelle , Davidson Nicholas 
Published: April 2020

BackgroundNon‐alcoholic fatty liver disease (NAFLD) affects approximately one‐quarter of the global population, with up to 20–25% developing progressive liver disease. Recent evidence in both humans and animal models show that maternal obesity is a risk factor for the development of NAFLD and progression to NASH. We have shown in a murine model of maternal obesity the offspring develop altered bile acid homeostasis and a varied response to a western diet which is passed by female offspring across generations. In this study we tested the hypothesis that male offspring exposed to maternal obesogenic diet pass an altered bile acid homeostasis phenotype and susceptibility to western diet induced liver disease to their offspring.MethodsFemale C57Bl6 mice were fed chow (CON) or HF/HS diet for 6 weeks to induce obesity and bred with lean males. Male F1 offspring were then bred with lean females to create a paternal second generation (PF2C from maternal CON lineage, PF2H from maternal HF/HS lineage). Tissues were collected from PF2 offspring to measure bile acid pool size and hepatic bile acid species profile. Additional PF2 offspring were fed high trans‐fat, cholesterol, fructose (HTFC) diet for 16 weeks to induce progressive NAFLD. Metabolic and histopathologic analyses were performed.ResultsIn chow fed PF2 offspring from the maternal HF/HS (mHF/HS) lineage, total BA pool size was increased. No change in intrahepatic BA composition was observed. After HTFC diet, PF2H offspring showed decreased liver weight and liver weight to body weight ratio compared to PF2C offspring. PF2H offspring exhibited lower levels of intrahepatic triglyceride and free fatty acids. Conversely, PF2H offspring liver showed increased Sirius red staining.ConclusionsMale offspring exposed to maternal obesogenic diet transmit a phenotype of altered BA homeostasis to their offspring. After exposure to a western diet, PF2H offspring exhibited worse fibrosis despite having less steatosis. Passage of these phenotypes through male offspring would suggest an epigenetic phenomenon as a mechanistic etiology. Future studies will evaluate the mechanism for transmission of maternal obesity driven changes in the liver across generations in the male lineage.
IPMK is Indispensable for Activation of AKT: Redefining PI3kinase pathway
Authors: Guha Prasun 
Published: April 2020

Inositol polyphosphate multikinase (IPMK) can catalyze production of IP5 and PIP3. Deletion of IPMK abolish AKT phosphorylation at both T 308 and Ser 473 residues even when PI3kinase activity of classical PI3kinase is intact. Akt activation requires its membrane localization followed by phosphorylation by PDK1 and mTORC2. We found that classical PI3kinase exclusively mediates AKT localization to the membrane but dispensable for PDK1 membrane localization and activation of mTORC2. IPMK interacts with both PDK1 and mTORC2 complex. Generation of PIP3 by IPMK promotes membrane localization of PDK1 and also activation of mTORC2, however, shows no effect in AKT localization to the membrane. In summary, PIP3 generated by IPMK exclusively controls PDK1 and mTORC2 functioning, however, classical PI3Kinase only controls AKT localization to the membrane.Support or Funding InformationNIH grant 5R01MH018501‐48
Tau Protein in Human Brain Vascular Smooth Muscle
Authors: Seeherman Sarah , Sariipek Nurefsan , Rybka Vladyslava , Shults Nataliia V. , Gychka Sergiy G. , Suzuki Yuichiro 
Published: April 2020

BackgroundIschemic stroke is a leading cause of long‐term disability and death worldwide. Thickening of the vascular wall and the reduction of lumen increase the incidence of ischemic stroke. Thus, therapeutic strategies targeting brain vascular narrowing should reduce the mortality and morbidity associated with ischemic stroke. Vascular smooth muscle cell (SMC) proliferation contributes to the development of vascular narrowing, however, cell signaling mechanisms of brain vascular SMC proliferation has not been defined. Tau is a microtubule‐associated protein indicated in various neurological pathologies, including Alzheimer’s disease. Although Tau protein is known to be expressed in neuronal cells, the role of Tau in brain vasculature is unknown. The present study tested the hypothesis that Tau is expressed in brain vascular SMCs.Methods & ResultsImmunohistochemistry of postmortem brain tissues from human patients died of ischemic stroke demonstrated the expression of Tau protein in the vascular smooth muscle media layer. Western blotting of cell lysates from cultured human brain vascular SMCs revealed the occurrence of a Tau isoform with a molecular weight of ~45 kD that was knocked down by Tau siRNA. Treatment of cells with a potent mitogen of SMCs, platelet‐derived growth factor (PDGF), promoted the phosphorylation of Tau at Thr181, but not, Ser198, Ser199, Ser202, Thr205, Thr212, Ser214, Ser356, Ser404, or Ser422. A Tau protein aggregation inhibitor, methylene blue, inhibited human brain vascular SMC growth.ConclusionsThis is the first demonstration that Tau protein is expressed in any kind of vascular SMCs. Moreover, results showing that PDGF causes the phosphorylation of Tau at a specific amino acid and a Tau aggregation inhibitor suppresses cell growth suggest that Tau may play a role in cell growth signaling in brain vascular SMCs.Support or Funding InformationSupported by NIH
Chronic Intermittent Hypoxia Blunts Phrenic Motor Plasticity: Role of Inflammation
Authors: El-Chami Mohamad , Mitchell Gordon , Gonzalez-Rothi Elisa 
Published: April 2020

Acute intermittent hypoxia (AIH) elicits a form of spinal, respiratory motor plasticity known as phrenic long‐term facilitation (pLTF). Preconditioning with a single day of chronic intermittent hypoxia (8 hours, 2 min hypoxic episodes with 2 min intervals) abolishes AIH‐induced pLTF through a mechanism that requires systemic inflammation and spinal p38 MAP kinase activation (Huxtable et al., 2015). pLTF is restored by high‐dose, systemic administration of the non‐steroidal anti‐inflammatory drug, ketoprofen, or spinal p38 MAP kinase inhibition. Similarly, preconditioning with 7 days of CIH (8 hours per day, 2 min episodes, 2 min intervals) abolishes pLTF, but we observed that phospho‐p38 within phrenic motor neurons is unchanged from control rats (Gonzalez‐Rothi and colleagues, unpublished). Thus, mechanisms whereby 7 days of CIH undermines AIH‐induced pLTF are unclear. Since CIH induces time‐dependent spinal inflammatory gene expression profiles over time (Smith et al., 2013), we hypothesize that prolonged CIH (versus a single day) blunts LTF through an inflammation‐dependent mechanism independent of p‐38MAP kinase. In ongoing experiments, we are evaluating whether anti‐inflammatory drugs restore AIH‐induced pLTF in rats preconditioned with prolonged CIH (7–28 days). Preliminary analyses in rats preconditioned with CIH for 7 days indicate that pLTF is expressed when ketoprofen is given on each day of the CIH exposure (67% baseline), but not when a single ketoprofen dose is given 3 hours prior to assessment of pLTF (−6% baseline). These experiments are the first to explore shifting mechanisms whereby prolonged CIH and associated inflammation undermine phrenic motor plasticity. Such experiments are essential since CIH is a hallmark of sleep apnea, a condition highly prevalent in individuals living with neurological disorders (spinal cord injury, ALS, etc.). It is therefore important to identify and mitigate factors which may undermine the potential for therapeutic interventions (i.e. repetitive AIH) to harness endogenous plasticity and ultimately improve breathing.Support or Funding InformationSupported by: Department of Defense: SCI160123 and NIH R01 HL147554
Exposure to Cigarette Smoke is Linked to Platelet‐Activating Factor Accumulation in Myocardial Tissue
Authors: Kispert Shannon E. , Adney Jacob , Hui Dawn S. , Kennedy Kelsey R. , McHowat Jane 
Published: April 2020

Smoking is a lifestyle risk factor for heart disease and is responsible for one‐third of all cardiovascular deaths. Although many studies have investigated the correlation between smoking and coronary artery disease, there are few studies examining the direct effect of smoking on the myocardium. In this study, we examined the effect of smoking on myocardial accumulation of platelet‐activating factor (PAF), a phospholipid mediator that causes a negative inotropic effect, arrhythmias, apoptosis and is involved in inflammation and atherosclerosis. Ventricular samples from mice exposed up to six months of cigarette smoke (48 min/day, 5 days/week), and human right atrial samples from smokers and nonsmokers scheduled for coronary artery bypass graft surgery were analyzed for biochemical and histochemical changes using activity assays, ELISA, immunoblot, and immunohistochemistry. Mice exposed to cigarette smoke showed a decrease in PAF‐acetylhydrolase (PAF‐AH, the enzyme responsible for PAF metabolism) activity that was significant after 1 month and decreased progressively over the 6 month period (5.8 ± 0.3 to 3.2 ± 0.5 nmol/mg protein/min, p<0.01, n=6). This inhibition in PAF‐AH activity was accompanied by increased myocardial PAF content (0.23 ± 0.04 to 0.35 ± 0.03 at 6 months smoking, p<0.05, n=6). In humans, smoking was associated with an increase in PAF content (3.19 ± 0.28 vs 4.29 ± 0.37 nmol/mg protein, p<0.05, n=18) and inhibition of PAF‐AH activity (30.7 ± 2.0 vs 23.2 ± 1.8 nmol/mg protein/min, p<0.01, n=18) when comparing atrial tissue from never smokers to current smokers. We did not detect a change in phospholipase A2 activity (the enzyme responsible for PAF production) in human or mouse myocardium exposed to cigarette smoke or room air. Thus, we hypothesize that the increase in PAF content in the myocardium is likely a result of smoking‐induced inhibition of PAF‐AH activity. The inhibition of PAF‐AH and subsequent accumulation of PAF in the myocardium of cigarette smokers may play a role in the pathogenesis of heart disease in this population.Support or Funding InformationLottie Caroline Hardy Foundation (to J.McH.)
Eating a high fat diet enhances sensitivity of rats to serotonin syndrome
Authors: Beltran Nina M. , Landavazo Antonio , Blough Bruce E. , Serafine Katherine M. 
Published: April 2020

Eating a high fat diet can lead to obesity, type 2 diabetes, and dysfunction to neurotransmitter systems. For example, eating high fat chow enhances sensitivity of rats to unconditioned behavioral effects (e.g., lower lip retraction) induced by 8‐OH‐DPAT, a serotonin (5‐HT)1A receptor agonist. It is not known if eating high fat chow also impacts sensitivity of rats to other types of 5‐HT receptor agonists, or other behaviors induced by these drugs, collectively referred to as animal models of 5‐HT syndrome (e.g., flat body posture and forepaw treading). Recently, the FDA approved lorcaserin, a 5‐HT2C receptor agonist for the treatment of obesity. Lorcaserin induces some 5‐HT syndrome behaviors in rats including forepaw treading; however, it is not known if diet impacts sensitivity of rats to these lorcaserin‐induced behaviors. Further, previous research suggests that females might be more sensitive to the effects of 5‐HT receptor agonists, and to the effects of eating a high fat diet. To test the hypothesis that eating high fat chow will enhance the sensitivity of rats to the behavioral effects of 5‐HT2C and 5‐HT1A receptor agonists, 16 male and 16 female rats eating high fat chow (60% kcal from fat) or standard chow (17% kcal from fat) were tested once weekly with cumulative doses of 8‐OH‐DPAT (0.01–1.0 mg/kg, s.c.), WAY 163909 (1.0–32.0 mg/kg, i.p.), or lorcaserin (1.0–32.0 mg/kg, i.p.). 8‐OH‐DPAT induced lower lip retraction, flat body posture, and forepaw treading, while WAY 163909 and lorcaserin only induced forepaw treading. Rats eating high fat chow were more sensitive to lower lip retraction (induced by 8‐OH‐DPAT) and forepaw treading (induced by all three serotonergic drugs), as compared to male rats eating standard chow. These experiments are still ongoing; however, preliminary data and previous reports suggest that female rats will be more sensitive than males to diet‐induced enhancements in 5‐HT syndrome behaviors. Future directions will use selective 5‐HT receptor antagonists to examine the specific receptor subtypes mediating these behavioral effects in male and female rats eating different diets.Support or Funding InformationThe authors have no conflicts to disclose. N.M.B. was awarded summer funding through the American Society for Pharmacology and Experimental Therapeutics (ASPET) Summer Undergraduate Research Fellowship (SURF). N.M.B is also supported by the National Institute of General Medical Sciences of the National Institutes of Health (NIH) under R25GM069621.
Inhibition of autophagy in prostate cancer cells stimulates Tau accumulation and aberrant mitotic spindle
Authors: Martellucci Stefano , Clementi Letizia , Colapietro Alessandro , Sabetta Samantha , Mattei Vincenzo , Angelucci Adriano 
Published: April 2020

INTRODUCTIONAutophagy is a self‐degrading adaptation mechanism in which cytoplasmic macromolecules and organelles are delivered to the lysosome for degradation and recycling. In a physiologic context autophagy could be both a cytoprotective driver and a programmed death facilitator. Sustained autophagy has been frequently detected in neoplastic transformation, even though its promoting role in cancer growth is not fully elucidated. In recent years, a significant correlation has emerged between molecular dysfunction leading to Tau protein accumulation and interference with mitosis progression. In our study we investigated the potential association between autophagy and Tau accumulation and its role during cell mitosis.METHODSWe evaluated in vitro the role of autophagy in modulating the expression of Tau protein in prostate cancer cell lines, analyzing morphological and molecular consequences during mitosis.RESULTSTau protein was expressed at low level in prostate cancer lines and western blot analysis showed in these cells the presence of several phosphorylated and oligomeric forms. The pharmacologic inhibition of autophagy by treatment with chloroquine, induced in cancer cells a reduction in proliferation with an increment of number of cells in G2/M phase of cell cycle. In addition, in these cells we observed an accumulation of Tau protein, with an increased expression of both phosphorylated and oligomeric forms. Immunofluorescence analysis of untreated cells revealed that Tau was expressed mainly in dividing cells where it was localized on mitotic spindle. Inhibition of autophagy determined an evident upregulation of Tau signal in dividing cells with a diffuse protein localization in cytoplasm. The accumulation of Tau protein was associated with the presence of aberrant mitotic spindles, with monoastral spindle as major unusual figure.CONCLUSIONSOur data indicate that autophagy could exert a promoting role in cancer growth facilitating degradation of Tau protein and thus blocking the inhibitory effect of accumulated Tau forms on mitosis. Thus, the understanding of molecular mechanisms underlying the homeostatic control of Tau protein degradation during cell mitosis could represent an important goal also in oncology research.
PHARMACOLOGICAL EVALUATION OF BETA‐HYDROXIPHOSPHOCARNITINE IN NO‐ALCOHOLIC ESTEATOHEPATITIS INDUCED IN RATS
Authors: Sánchez-Quevedo Janet , Reyes-Esparza Jorge , Duarte-Vazquez Miguel Angel , Rodriguez-Fragoso Lourdes 
Published: April 2020

ObjectiveTo evaluate the pharmacological effect of Β‐Hydroxyphosphocarnitine (β‐HFC) on non‐alcoholic steatohepatitis induced in rats.IntroductionNon‐alcoholic fatty liver disease (EHGNA) is a disease with high prevalence, usually accompanied by metabolic syndrome. Currently the treatment to EHGNA is pioglitazone. However, it is reported that pioglitazone causes several side effects reason to stop treatment. L‐carnitine has pharmacological effect in the metabolic syndrome, but it is poorly absorbed. The β‐HFC is an analogue of L‐carnitine that has shown effect on metabolic síndrome and maintaining its pharmacological properties.MethodEHGNA was developed in male Wistar rats with a mixed diet based on coconut oil, carbon tetrachloride and high fructose drink. The treatments were as follows: Without treatment, pioglitazone and β‐HFC in healthy groups and with EHGNA. Histological sections of the liver were made and stained with Masson's Trichromic Stain to see collagen fibers and Hematoxylin & Eosin to see hepatocyte morphology. Quantities of liver enzymes Aspartate aminotransferase (AST), alanine aminotransferase (ALT), Gamma glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP) and triglycerides were performed.ResultsIn the histology of the healthy control rats, the hepatocyte architecture is well observed, no liver damage characteristics are observed, for example: fat drops, inflammatory cells, necrosis, apoptosis and hepatocytes in the balloon. Healthy groups administered with pioglitazone and β‐HFC as well as the control show no characteristics of liver damage. Histologies of rats with EHGNA showed the characteristics of liver damage and greater amount of collagen fibers. Rats with steatophepatitis treated with β‐HFC showed reduced hepatocyte damage and fibrosis compared to EHGNA control rats. Liver enzyme levels increased 2.5 times more in the steatohepatitis group compared to those in control rats. Liver enzyme levels showed considerable reduction in those rats with statohepatitis and were treated with β‐HFC, showing values for the enzymes ALT, AST, GGT and ALP 85.79, 101.3, 3.2 and 556.4 U/L, respectively for group with steatohepatitis and 74.34, 77.7, 1.0 and 327 U/L, respectively for the group with steatohepatitis treated with β‐HFC. Triglyceride levels increased in rats with steatohepatitis compared to those in control rats and reduction in levels was observed for those who were treated with β‐HFC showing values of 63.7 (control), 255.1 (steatohepatitis) and 48.4 mg/dL (steatohepatitis + β‐HFC). The same behavior showed liver levels 0.04, 0.14 and 0.04 mg/dL respectively.ConclusionB‐HFC reduced liver damage levels in rats with EHGNA.
Model‐Based Analysis of Lower Thoracic High‐Frequency Spinal Cord Stimulation (HF‐SCS) to Restore Effective Cough
Authors: Zander Hans J. , Kowalski Krzysztof E. , DiMarco Anthony F. , Lempka Scott F. 
Published: April 2020

BackgroundSpinal cord stimulation (SCS, 50 Hz) is a useful method to restore an effective cough in persons with spinal cord injury (SCI). In animal models, dorsal HF‐SCS (~500 Hz) produces similar level of expiratory muscle activation with much lower stimulus amplitudes. Currently, the mechanism of this behavior is unknown.ObjectiveThe aim of the present study was to develop a computational model of lower thoracic SCS to investigate the mechanisms of the expiratory muscle activation via HF‐SCS.MethodsWe created a computer model of an anatomically‐accurate finite element model (FEM) of the lower thoracic (T9) canine spinal cord and surrounding anatomy with an implanted SCS electrode array. This model consisted of two main components: 1) multicompartment cable models of dorsal afferent fibers and 2) ventral motor axons. Model analysis allowed calculation of the extracellular voltages generated during SCS and the corresponding activation thresholds of each fiber type.ResultsIn our simulations, we calculated the activation thresholds for several electrode combinations and stimulation frequencies (50 Hz, 500 Hz). As expected, the activation thresholds of the ventral motor axons were significantly higher than the activation thresholds of dorsal root axons. Therefore, low‐frequency SCS likely functions through the direct activation of ventral motor axons, while high‐frequency SCS operates via recruitment of myelinated afferent fibers at significantly lower stimulation amplitudes. In our simulations, the stimulation frequency did not significantly alter activation thresholds in dorsal or ventral axons.ConclusionsOur results suggest that both high‐ and low‐frequency SCS directly activate dorsal rootlets at low amplitudes (~1 mA); however, the trans‐synaptic spinal circuits responsible for eliciting cough are only effective at higher stimulation frequencies. Consequently, low‐frequency stimulation results in effective cough by bypassing this circuitry entirely to directly activate the ventral motor axons at the cost of requiring higher stimulation amplitudes. In future work, we will perform simulations directly assessing the ability of SCS to engage these spinal circuits. We will compare our model results to experimental measurements in an animal model of SCS to produce cough.DisclosureDr. DiMarco holds two U.S. patents for technology related to the content of this abstract: Method and Apparatus for Electrical Activation of the Expiratory Muscles to Restore Cough (5,999,855) and Bipolar Spinal Cord Stimulation to Activate the Expiratory Muscles to Restore Cough (8,751,004).Support or Funding InformationMerit Review Award I01‐RX‐001488 from the U.S. Department of Veterans Affairs, Rehabilitation Research and Development Service.