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Sample records for chronic hypoxic mouse

  1. Renal kallikrein in chronic hypoxic rats.

    PubMed

    Chen, C F; Chen, L W; Chien, C T; Wu, M S; Tsai, T J

    1996-09-01

    1. We have studied the role of kallikrein (KK) in the maintenance of renal function in chronic hypoxic rats (high altitude; HA), compared with control rats kept at sea level (SL). Hypoxia was induced by placing female Wistar rats (198-290 g) in an altitude chamber (5500 m) 15 h/day for 4 weeks. Experiments were also conducted to study the interaction of KK with renal nerve activity and endothelin (ET), two parameters previously shown to be altered in this model. 2. It was found that renal cortex tissue KK activity (TKA) was not significantly different in 10 SL and 10 HA rats. However, the urinary KK activity (UKA) was reduced nearly to half (from 35.2 +/- 4.6 to 18.5 +/- 1.7 pkat/min) in HA rats after 4 weeks of chronic hypoxia. 3. Acute renal denervated diuresis was accompanied by a significant increase in UKA (from 9 +/- 2 to 14 +/- 2 pkat/min in HA and denervated HA rats, respectively; P < 0.05) in HA rats. Intrarenal arterial pretreatment of aprotinin reduced the denervated diuresis. 4. Endothelin (600 ng/kg per h) reduced urine flow, sodium and potassium excretion in the ipsilateral kidney in another 10 SL and 10 HA rats. The extent of the drop of these parameters was significantly less in HA rats. Urinary KK activity was correlated significantly with the measured renal functional parameters (r ranging from 0.472 to 0.612) in SL rats, but was insignificant in HA rats (r ranging from 0.032 to 0.192). 5. We have demonstrated that chronic exposure to hypoxia decreases urinary KK excretion and that KK is involved in acute renal denervated diuresis generated in these animals. The present study suggests that KK plays a partial role in the maintenance of renal function in chronic hypoxic rats. PMID:8911720

  2. Hypoxic pulmonary hypertension in chronic lung diseases: novel vasoconstrictor pathways.

    PubMed

    Rowan, Simon C; Keane, Michael P; Gaine, Seán; McLoughlin, Paul

    2016-03-01

    Pulmonary hypertension is a well recognised complication of chronic hypoxic lung diseases, which are among the most common causes of death and disability worldwide. Development of pulmonary hypertension independently predicts reduced life expectancy. In chronic obstructive pulmonary disease, long-term oxygen therapy ameliorates pulmonary hypertension and greatly improves survival, although the correction of alveolar hypoxia and pulmonary hypertension is only partial. Advances in understanding of the regulation of vascular smooth muscle tone show that chronic vasoconstriction plays a more important part in the pathogenesis of hypoxic pulmonary hypertension than previously thought, and that structural vascular changes contribute less. Trials of existing vasodilators show that pulmonary hypertension can be ameliorated and systemic oxygen delivery improved in carefully selected patients, although systemic hypotensive effects limit the doses used. Vasoconstrictor pathways that are selective for the pulmonary circulation can be blocked to reduce hypoxic pulmonary hypertension without causing systemic hypotension, and thus provide potential targets for novel therapeutic strategies. PMID:26895650

  3. Mechanical properties and reactivity of vessels in isolated perfused lungs of chronically hypoxic rats.

    PubMed

    Emery, C J; Bee, D; Barer, G R

    1981-11-01

    1. Chronically hypoxic rats kept in 10% (v/v) O2 for 3--6 weeks, were compared with littermate control rats. Pulmonary vascular resistance, measured from the slope of the pressure-flow relationship in isolated lungs perfused with blood of normal packed cell volume was higher in chronically hypoxic than control rats even during normoxia. 2. Chronically hypoxic rats weighed less than control rats but their pulmonary vascular volume, measured with labelled albumin was similar to control rats. This, together with evidence that the number of precapillary vessels is not reduced, does not suggest a large reduction in the vascular bed in chronic hypoxia. 3. A greater vasodilator action of isoprenaline and adenosine in chronically hypoxic than control lungs suggested a higher normoxic vascular tone. This higher tone was not the sole cause of increased resistance in chronically hypoxic lungs, since maximal vasodilatation did not reduce resistance to control levels. The chief cause was probably encroachment of new muscle on the vascular lumen of small vessels. 4. Pulmonary arterial compliance was reduced in chronically hypoxic lungs. 5. Reactivity of vessels to ventilation hypoxia, over a wide range of oxygen tension, to angiotensin II (ANG II) and to adenosine 5'-triphosphate (ATP) was significantly greater in chronically hypoxic than control lungs, but thresholds to these stimuli were not reduced. PMID:7285503

  4. Effect of alveolar pressure on pulmonary artery pressure in chronically hypoxic rats.

    PubMed

    Wach, R; Emery, C J; Bee, D; Barer, G R

    1987-02-01

    The effect on pulmonary artery pressure of a rise in alveolar pressure differed in chronically hypoxic rats (10% O2 for 3-5 weeks) compared with control rats. Chronically hypoxic rats have newly muscularised walls in arterioles in the alveolar region. Isolated lungs of chronically hypoxic and control rats were perfused with blood under conditions in which alveolar pressure was greater than left atrial pressure during both normoxia and hypoxia. Alveolar pressure was the effective downstream pressure. Pressure-flow lines were measured at low and high alveolar pressure (5 and 15 mmHg). During normoxia pressure-flow lines of chronically hypoxic rats had a steeper slope (higher resistance) and greater extrapolated intercept on the pressure axis (effective downstream pressure) than control rats. In both groups of rats the change from low to high alveolar pressure during normoxia caused an approximately parallel shift in the pressure-flow line similar to the change in alveolar pressure. During hypoxia, which led to an increase in slope and intercept in both groups of rats, the effect of a rise in alveolar pressure differed in chronically hypoxic from control rats. In control rats there was a small parallel shift in the pressure-flow line that was much less than the increase in alveolar pressure; in chronically hypoxic rats there was a large parallel shift in the pressure-flow line that was greater than the increase in alveolar pressure. Thus in chronically hypoxic rats hypoxic vasoconstriction probably occurred mainly in muscular alveolar vessels, whereas in control rats it probably occurred upstream in extra-alveolar vessels. At constant blood flow the relation between pulmonary artery pressure and alveolar pressure was measured while alveolar pressure was reduced from approximately 15 mmHg to zero during both normoxia and hypoxia. In control and chronically hypoxic rats the slope of this line was less than 1. At an alveolar pressure of 2-3 mmHg there was an inflection

  5. Adaptation of the myoglobin knockout mouse to hypoxic stress.

    PubMed

    Schlieper, Georg; Kim, Jie-Hoon; Molojavyi, Andrei; Jacoby, Christoph; Laussmann, Tim; Flögel, Ulrich; Gödecke, Axel; Schrader, Jürgen

    2004-04-01

    Myoglobin knockout (myo-/-) mice were previously reported to show no obvious phenotype but revealed several compensatory mechanisms that include increases in cardiac capillary density, coronary flow, and hemoglobin. The aim of this study was to investigate whether severe hypoxic stress can exhaust these compensatory mechanisms and whether this can be monitored on the gene and protein level. Myo-/- and wild-type (WT) mice we e exposed to hypoxia (10% O(2)) fo 2 wk. Thereafter hemodynamic parameters were investigated by invasive measurement combined with magnetic resonance imaging. Cardiac gene and protein expression were analyzed using cDNA arrays and two-dimensional gel electrophoresis plus mass spectrometry, respectively. Hematocrit levels increased from 44% (WT) and 48% (myo-/-) to 72% in both groups. Similar to WT controls, hypoxic myo-/- animals maintained stable cardiovascular function (mean arterial blood pressure 82.4 mmHg, ejection fraction 72.5%). Cardiac gene expression of hypoxic myo-/- mice differed significantly from WT controls in 17 genes (e.g., keratinocyte lipid binding protein +202%, cytochrome c oxidase Vb +41%). Interestingly, hypoxia inducible factor-1alpha remained unchanged in both groups. Proteome analysis revealed reduced levels of heart fatty acid-binding protein and heat shock protein 27 both in hypoxic myo-/- and WT mice. Our data thus demonstrate that myo-/- mice do not decompensate du ing hypoxic st ess but a e surprisingly well adapted. Changes in ene gy metabolism of fatty acids may contribute to the robustness of myoglobin-deficient mice. PMID:14656764

  6. Blunted Hypoxic Pulmonary Vasoconstriction in Experimental Neonatal Chronic Lung Disease

    PubMed Central

    Rey-Parra, Gloria Juliana; Archer, Stephen L.; Bland, Richard D.; Albertine, Kurt H.; Carlton, David P.; Cho, Soo-Chul; Kirby, Beth; Haromy, Al; Eaton, Farah; Wu, Xichen; Thébaud, Bernard

    2008-01-01

    Rationale: Neonatal chronic lung disease (CLD), caused by prolonged mechanical ventilation (MV) with O2-rich gas, is the most common cause of long-term hospitalization and recurrent respiratory illness in extremely premature infants. Recurrent episodes of hypoxemia and associated ventilator adjustments often lead to worsening CLD. The mechanism that causes these hypoxemic episodes is unknown. Hypoxic pulmonary vasoconstriction (HPV), which is partially controlled by O2-sensitive voltage-gated potassium (Kv) channels, is an important adaptive response to local hypoxia that helps to match perfusion and ventilation in the lung. Objectives: To test the hypothesis that chronic lung injury (CLI) impairs HPV. Methods: We studied preterm lambs that had MV with O2-rich gas for 3 weeks and newborn rats that breathed 95%-O2 for 2 weeks, both of which resulted in airspace enlargement and pulmonary vascular changes consistent with CLD. Measurements and Main Results: HPV was attenuated in preterm lambs with CLI after 2 weeks of MV and in newborn rats with CLI after 2 weeks of hyperoxia. HPV and constriction to the Kv1.x-specific inhibitor, correolide, were preferentially blunted in excised distal pulmonary arteries (dPAs) from hyperoxic rats, whose dPAs exhibited decreased Kv1.5 and Kv2.1 mRNA and K+ current. Intrapulmonary gene transfer of Kv1.5, encoding the ion channel that is thought to trigger HPV, increased O2-sensitive K+ current in cultured smooth muscle cells from rat dPAs, and restored HPV in hyperoxic rats. Conclusions: Reduced expression/activity of O2-sensitive Kv channels in dPAs contributes to blunted HPV observed in neonatal CLD. PMID:18511704

  7. Changes in misonidazole binding with hypoxic fraction in mouse tumors

    SciTech Connect

    Hirst, D.G.; Hazlehurst, J.L.; Brown, J.M.

    1985-07-01

    Binding of misonidazole (MISO) or a derivative to hypoxic cells in tumors has been proposed as a method for identifying tumors, and measuring their level of hypoxia. The author has recently shown that the hypoxic fraction of tumor cells can be altered over a wide range in vivo by acutely changing the hematocrit of the host animal by transfusion. The present study is aimed to investigate the changes in binding by /sup 14/C MISO that accompanied this procedure. Tumor bearing mice were injected with /sup 14/C MISO, irradiated with a single dose of X rays (20 Gy) and their tumor excised and bisected. One half of each tumor was used to determine cell survival in vitro, the other was used for /sup 14/C scintillation counting. As previously described, tumor cell survival was dramatically increased in acutely anemic mice and this was accompanied by an increase in /sup 14/C MISO binding to the tumors. The relationship between clonogenic cell survival and binding was found to be linear on a log-log plot for each of the tumor lines studied, but the slopes of the lines were different in different tumor lines and generally steeper than the value of 1.0 expected for a 1:1 correspondence between cells binding radioactivity and radiobiological resistance.

  8. Effects of chronic normobaric hypoxic and hypercapnic exposure in rats: Prevention of experimental chronic mountain sickness by hypercapnia

    NASA Astrophysics Data System (ADS)

    Lincoln, B.; Bonkovsky, H. L.; Ou, Lo-Chang

    1987-09-01

    A syndrome of experimental chronic mountain sickness can be produced in the Hilltop strain of Sprague-Dawley rats by chronic hypobaric hypoxic exposure. This syndrome is characterized by polycythemia, plasma hemoglobinemia, pulmonary hypertension and right ventricular hypertrophy with eventual failure and death. It has generally been assumed that these changes are caused by chronic hypoxemia, not by hypobaric exposure per se. We have now confirmed this directly by showing that chronic normobaric hypoxic exposure (10.5% O2) produces similar hematologic and hemodynamic changes. Further, the addition of hypercapnic exposure to the hypoxic exposure blunted or prevented the effects of the hypoxic exposure probably by stimulating respiration, thus increasing the rate of oxygen delivery to the cells. Changes in the rate-controlling enzymes of hepatic heme metabolism, 5-aminolevulinate synthase and heme oxygenase, and in cytochrome(s) P-450, the major hepatic hemoprotein(s), were also measured in hypoxic and hypercapnic rats. Hypoxia decreased 5-aminolevulinate synthase and increased cytochrome(s) P-450, probably by increasing the size of a “regulatory” heme pool within hepatocytes. These changes were also prevented by the addition of hypercapnic to hypoxic exposure.

  9. Stiffening of the Extrapulmonary Arteries From Rats in Chronic Hypoxic Pulmonary Hypertension.

    PubMed

    Drexler, E S; Bischoff, J E; Slifka, A J; McCowan, C N; Quinn, T P; Shandas, R; Ivy, D D; Stenmark, K R

    2008-01-01

    Changes in the compliance properties of large blood vessels are critical determinants of ventricular afterload and ultimately dysfunction. Little is known of the mechanical properties of large vessels exhibiting pulmonary hypertension, particularly the trunk and right main artery. We initiated a study to investigate the influence of chronic hypoxic pulmonary hypertension on the mechanical properties of the extrapulmonary arteries of rats. One group of animals was housed at the equivalent of 5000 m elevation for three weeks and the other held at ambient conditions of ~1600 m. The two groups were matched in age and gender. The animals exposed to hypobaric hypoxia exhibited signs of pulmonary hypertension, as evidenced by an increase in the RV/(LV+S) heart weight ratio. The extrapulmonary arteries of the hypoxic animals were also thicker than those of the control population. Histological examination revealed increased thickness of the media and additional deposits of collagen in the adventitia. The mechanical properties of the trunk, and the right and left main pulmonary arteries were assessed; at a representative pressure (7 kPa), the two populations exhibited different quantities of stretch for each section. At higher pressures we noted less deformation among the arteries from hypoxic animals as compared with controls. A four-parameter constitutive model was employed to fit and analyze the data. We conclude that chronic hypoxic pulmonary hypertension is associated with a stiffening of all the extrapulmonary arteries. PMID:27096124

  10. Stiffening of the Extrapulmonary Arteries From Rats in Chronic Hypoxic Pulmonary Hypertension

    PubMed Central

    Drexler, E. S; Bischoff, J. E; Slifka, A. J; McCowan, C. N; Quinn, T. P; Shandas, R; Ivy, D. D; Stenmark, K. R

    2008-01-01

    Changes in the compliance properties of large blood vessels are critical determinants of ventricular afterload and ultimately dysfunction. Little is known of the mechanical properties of large vessels exhibiting pulmonary hypertension, particularly the trunk and right main artery. We initiated a study to investigate the influence of chronic hypoxic pulmonary hypertension on the mechanical properties of the extrapulmonary arteries of rats. One group of animals was housed at the equivalent of 5000 m elevation for three weeks and the other held at ambient conditions of ~1600 m. The two groups were matched in age and gender. The animals exposed to hypobaric hypoxia exhibited signs of pulmonary hypertension, as evidenced by an increase in the RV/(LV+S) heart weight ratio. The extrapulmonary arteries of the hypoxic animals were also thicker than those of the control population. Histological examination revealed increased thickness of the media and additional deposits of collagen in the adventitia. The mechanical properties of the trunk, and the right and left main pulmonary arteries were assessed; at a representative pressure (7 kPa), the two populations exhibited different quantities of stretch for each section. At higher pressures we noted less deformation among the arteries from hypoxic animals as compared with controls. A four-parameter constitutive model was employed to fit and analyze the data. We conclude that chronic hypoxic pulmonary hypertension is associated with a stiffening of all the extrapulmonary arteries. PMID:27096124

  11. Combination of nicotinamide and hyperthermia to eliminate radioresistant chronically and acutely hypoxic tumor cells

    SciTech Connect

    Horsman, M.R.; Chaplin, D.J.; Overgaard, J. )

    1990-12-01

    The interaction among nicotinamide, radiation, and heat was studied in vivo using a C3H mouse mammary carcinoma grown in the feet of CDF1 mice. Response following local tumor treatment was assessed by tumor control and regrowth delay. Nicotinamide (1000 mg/kg i.p.) produced maximal radiosensitization when injected 30 min to 2 h before irradiation (enhancement ratios (ERs), 1.2-1.5). Radiation damage was also increased by heating tumors (43.5 degrees C for 60 min) 4 h after irradiation (ERs = 1.6-2.6). This combined radiation and heat treatment was enhanced by nicotinamide but the effect depended on the assay procedure, such that although a significant increase was observed with the tumor control assay, only a slight increase was seen using regrowth delay as the end point. The development of moist desquamation in normal feet was used to estimate skin damage after irradiation. Nicotinamide and heat both resulted in a small yet significant increase in skin damage (ERs less than 1.2 and 1.1, respectively). A combined treatment resulted in a greater ER of 1.7, but when compared to the tumor response it still gave a therapeutic gain. A histological fluorescent staining technique was used to assess functional tumor vasculature at two periods in time separated by 20 min. Under normal conditions 7.7% of the vessels in this tumor were functional at one time but not the other. This value was reduced to 2.8% after nicotinamide administration. Since these fluctuations in blood flow can result in acute hypoxia we conclude that while heat eliminates chronically hypoxic tumor cells, nicotinamide probably removes the presence of acute hypoxia.

  12. Optimization of isolated perfused/ventilated mouse lung to study hypoxic pulmonary vasoconstriction

    PubMed Central

    Yoo, Hae Young; Zeifman, Amy; Ko, Eun A.; Smith, Kimberly A.; Chen, Jiwang; Machado, Roberto F.; Zhao, You-Yang; Minshall, Richard D.; Yuan, Jason X.-J.

    2013-01-01

    Hypoxic pulmonary vasoconstriction (HPV) is a compensatory physiological mechanism in the lung that optimizes the matching of ventilation to perfusion and thereby maximizes gas exchange. Historically, HPV has been primarily studied in isolated perfused/ventilated lungs; however, the results of these studies have varied greatly due to different experimental conditions and species. Therefore, in the present study, we utilized the mouse isolated perfused/ventilated lung model for investigation of the role of extracellular Ca2+ and caveolin-1 and endothelial nitric oxide synthase expression on HPV. We also compared HPV using different perfusate solutions: Physiological salt solution (PSS) with albumin, Ficoll, rat blood, fetal bovine serum (FBS), or Dulbecco's Modified Eagle Medium (DMEM). After stabilization of the pulmonary arterial pressure (PAP), hypoxic (1% O2) and normoxic (21% O2) gases were applied via a ventilator in five-minute intervals to measure HPV. The addition of albumin or Ficoll with PSS did not induce persistent and strong HPV with or without a pretone agent. DMEM with the inclusion of FBS in the perfusate induced strong HPV in the first hypoxic challenge, but the HPV was neither persistent nor repetitive. PSS with rat blood only induced a small increase in HPV amplitude. Persistent and repetitive HPV occurred with PSS with 20% FBS as perfusate. HPV was significantly decreased by the removal of extracellular Ca2+ along with addition of 1 mM EGTA to chelate residual Ca2+ and voltage-dependent Ca2+ channel blocker (nifedipine 1 μM). PAP was also reactive to contractile stimulation by high K+ depolarization and U46619 (a stable analogue of thromboxane A2). In summary, optimal conditions for measuring HPV were established in the isolated perfused/ventilated mouse lung. Using this method, we further confirmed that HPV is dependent on Ca2+ influx. PMID:24015341

  13. Hypoxic alligator embryos: chronic hypoxia, catecholamine levels and autonomic responses of in ovo alligators.

    PubMed

    Eme, John; Altimiras, Jordi; Hicks, James W; Crossley, Dane A

    2011-11-01

    Hypoxia is a naturally occurring environmental challenge for embryonic reptiles, and this is the first study to investigate the impact of chronic hypoxia on the in ovo development of autonomic cardiovascular regulation and circulating catecholamine levels in a reptile. We measured heart rate (f(H)) and chorioallantoic arterial blood pressure (MAP) in normoxic ('N21') and hypoxic-incubated ('H10'; 10% O(2)) American alligator embryos (Alligator mississippiensis) at 70, 80 and 90% of development. Embryonic alligator responses to adrenergic blockade with propranolol and phentolamine were very similar to previously reported responses of embryonic chicken, and demonstrated that embryonic alligator has α and β-adrenergic tone over the final third of development. However, adrenergic tone originates entirely from circulating catecholamines and is not altered by chronic hypoxic incubation, as neither cholinergic blockade with atropine nor ganglionic blockade with hexamethonium altered baseline cardiovascular variables in N21 or H10 embryos. In addition, both atropine and hexamethonium injection did not alter the generally depressive effects of acute hypoxia - bradycardia and hypotension. However, H10 embryos showed significantly higher levels of noradrenaline and adrenaline at 70% of development, as well as higher noradrenaline at 80% of development, suggesting that circulating catecholamines reach maximal levels earlier in incubation for H10 embryos, compared to N21 embryos. Chronically elevated levels of catecholamines may alter the normal balance between α and β-adrenoreceptors in H10 alligator embryos, causing chronic bradycardia and hypotension of H10 embryos measured in normoxia. PMID:21798363

  14. General Anesthetics Inhibit Erythropoietin Induction under Hypoxic Conditions in the Mouse Brain

    PubMed Central

    Tanaka, Tomoharu; Kai, Shinichi; Koyama, Tomohiro; Daijo, Hiroki; Adachi, Takehiko; Fukuda, Kazuhiko; Hirota, Kiichi

    2011-01-01

    Background Erythropoietin (EPO), originally identified as a hematopoietic growth factor produced in the kidney and fetal liver, is also endogenously expressed in the central nervous system (CNS). EPO in the CNS, mainly produced in astrocytes, is induced under hypoxic conditions in a hypoxia-inducible factor (HIF)-dependent manner and plays a dominant role in neuroprotection and neurogenesis. We investigated the effect of general anesthetics on EPO expression in the mouse brain and primary cultured astrocytes. Methodology/Principal Findings BALB/c mice were exposed to 10% oxygen with isoflurane at various concentrations (0.10–1.0%). Expression of EPO mRNA in the brain was studied, and the effects of sevoflurane, halothane, nitrous oxide, pentobarbital, ketamine, and propofol were investigated. In addition, expression of HIF-2α protein was studied by immunoblotting. Hypoxia-induced EPO mRNA expression in the brain was significantly suppressed by isoflurane in a concentration-dependent manner. A similar effect was confirmed for all other general anesthetics. Hypoxia-inducible expression of HIF-2α protein was also significantly suppressed with isoflurane. In the experiments using primary cultured astrocytes, isoflurane, pentobarbital, and ketamine suppressed hypoxia-inducible expression of HIF-2α protein and EPO mRNA. Conclusions/Significance Taken together, our results indicate that general anesthetics suppress activation of HIF-2 and inhibit hypoxia-induced EPO upregulation in the mouse brain through a direct effect on astrocytes. PMID:22216265

  15. Stretch-activated channels in pulmonary arterial smooth muscle cells from normoxic and chronically hypoxic rats.

    PubMed

    Ducret, Thomas; El Arrouchi, Jalila; Courtois, Arnaud; Quignard, Jean-François; Marthan, Roger; Savineau, Jean-Pierre

    2010-11-01

    Stretch-activated channels (SACs) act as membrane mechanotransducers since they convert physical forces into biological signals and hence into a cell response. Pulmonary arterial smooth muscle cells (PASMCs) are continuously exposed to mechanical stimulations e.g., compression and stretch, that are enhanced under conditions of pulmonary arterial hypertension (PAH). Using the patch-clamp technique (cell-attached configuration) in PASMCs, we showed that applying graded negative pressures (from 0 to -60 mmHg) to the back end of the patch pipette increases occurrence and activity of SACs. The current-voltage relationship (from -80 to +40 mV) was almost linear with a reversal potential of 1 mV and a slope conductance of 34 pS. SACs were inhibited in the presence of GsMTx-4, a specific SACs blocker. Using microspectrofluorimetry (indo-1), we found that hypotonic-induced cell swelling increases intracellular Ca(2+) concentration ([Ca(2+)](i)). This [Ca(2+)](i) increase was markedly inhibited in the absence of external Ca(2+) or in the presence of the following blockers of SACs: gadolinium, streptomycin, and GsMTx-4. Interestingly, in chronically hypoxic rats, an animal model of PAH, SACs were more active and hypotonic-induced calcium response in PASMCs was significantly higher (nearly a two-fold increase). Moreover, unlike in normoxic rats, intrapulmonary artery rings from hypoxic rats mounted in a Mulvany myograph, exhibited a myogenic tone sensitive to SAC blockers. In conclusion, this work demonstrates that SACs in rat PASMCs can be activated by membrane stretch as well as hypotonic stimulation and are responsible for [Ca(2+)](i) increase. The link between SACs activation-induced calcium response and myogenic tone in chronically hypoxic rats suggests that SACs are an important element for the increased pulmonary vascular tone in PAH and that they may represent a molecular target for PAH treatment. PMID:21035852

  16. Intermittent negative pressure ventilation in the treatment of hypoxic hypercapnic coma in chronic respiratory insufficiency.

    PubMed Central

    Corrado, A; De Paola, E; Gorini, M; Messori, A; Bruscoli, G; Nutini, S; Tozzi, D; Ginanni, R

    1996-01-01

    BACKGROUND: In recent years non-invasive ventilatory techniques have been used successfully in the treatment of acute on chronic respiratory failure (ACRF), but careful selection of patients is essential and a comatose state may represent an exclusion criterion. The aim of this retrospective and uncontrolled study was to evaluate whether a non-invasive ventilatory technique such as the iron lung could also be used successfully in patients with hypoxic hypercapnic coma, thus widening the range for application of non-invasive ventilatory techniques. METHODS: A series of 150 consecutive patients with ACRF and hypoxic hypercapnic coma admitted to our respiratory intensive care unit were evaluated retrospectively. The most common underlying condition was chronic obstructive pulmonary disease (79%). On admission a severe hypoxaemia (Pao2 5.81 (3.01) kPa) and hypercapnia (Paco2 14.88 (2.78) kPa) associated with a decompensated acidosis (pH 7.13 (0.13)) were present, the Glasgow coma score ranged from 3 to 8, and the mean APACHE II score was 31.6 (5.3). All patients underwent intermittent negative pressure ventilation with the iron lung. The study end point was based on a dichotomous classification of treatment failure (defined as death or need for endotracheal intubation) versus therapeutic success. RESULTS: There were 45 treatment failures (30%) and 36 deaths (24%). Nine patients (6%) required intubation because of lack of airway control. The median total duration of ventilation was 27 hours per patient (range 2-274). The 105 successfully treated cases recovered consciousness after a median of four hours (range 1-90) of continuous ventilatory treatment and were discharged after 12.1 (9.0) days. CONCLUSIONS: These results show that, in patients with acute on chronic respiratory failure and hypoxic hypercapnic coma, the iron lung resulted in a high rate of success. As this study has the typical limitations of all retrospective and uncontrolled studies, the results need to

  17. BrdU-positive cells in the neonatal mouse hippocampus following hypoxic-ischemic brain injury

    PubMed Central

    Bartley, John; Soltau, Thomas; Wimborne, Hereward; Kim, Sunjun; Martin-Studdard, Angeline; Hess, David; Hill, William; Waller, Jennifer; Carroll, James

    2005-01-01

    Background Mechanisms that affect recovery from fetal and neonatal hypoxic-ischemic (H-I) brain injury have not been fully elucidated. The incidence of intrapartum asphyxia is approximately 2.5%, but the occurrence of adverse clinical outcome is much lower. One of the factors which may account for this relatively good outcome is the process of neurogenesis, which has been described in adult animals. We used a neonatal mouse model to assess new cells in the hippocampus after H-I injury. Results Neonatal mice underwent permanent unilateral carotid ligation on the seventh postnatal day followed by exposure to 8% hypoxia for 75 minutes. The presence of new cells was determined by bromodeoxyuridine (BrdU) incorporation into cells with sacrifice of the animals at intervals. Brain sections were stained for BrdU in combination with neuronal, glial, endothelial and microglial stains. We found a significant increase in BrdU-positive cells in the neonatal mouse hippocampus in the injured area compared to the non-injured area, most prominent in the dentate gyrus (DG) (154.5 ± 59.6 v. 92.9 ± 32.7 at 3 days after injury; 68.9 ± 23.4 v. 52.4 ± 17.1 at 35 days after injury, p < 0.0011). Among the cells which showed differentiation, those which were stained as either microglial or endothelial cells showed a peak increase at three days after the injury in the DG, injured versus non-injured side (30.5 ± 17.8 v. 2.7 ± 2.6, p < 0.0002). As in the adult animal, neurogenesis was significantly increased in the DG with injury (15.0 ± 4.6 v. 5.2 ± 1.6 at 35 days after injury, p < 0.0002), and this increase was subsequent to the appearance of the other dividing cells. Numbers of new oligodendrocytes were significantly higher in the DG on the non-injured side (7.0 ± 24.2 v. 0.1 ± 0.3, p < 0.0002), suggesting that oligodendrocyte synthesis was reduced in the injured hippocampus. Conclusion These findings demonstrate that the neonatal animal responds to brain injury with neurogenesis

  18. Haemodynamic effects of atrial natriuretic peptide in hypoxic chronic obstructive pulmonary disease.

    PubMed Central

    Rogers, T. K.; Sheedy, W.; Waterhouse, J.; Howard, P.; Morice, A. H.

    1994-01-01

    BACKGROUND--Pulmonary artery pressure is elevated in patients with advanced chronic obstructive pulmonary disease (COPD). Release of atrial natriuretic peptide (ANP) is increased in pulmonary hypertension and this hormone may both selectively vasodilate pulmonary vessels and inhibit pulmonary vascular remodelling. The hypothesis that ANP has a physiological role in protection of the pulmonary circulation from pressure overload, and that it may be beneficial in patients with COPD, has been examined. METHODS--Ten patients with hypoxic COPD were infused for 30 minute periods with saline followed by ANP at 0.4, 2, and 10 pmol/kg/min respectively via a pulmonary artery catheter whilst monitoring haemodynamics and oxygenation. RESULTS--Levels of immunoreactive ANP (irANP) increased from a mean (SD) of 23 (15) pmol/l to a maximum of 94 (41) pmol/l. Neither systemic blood pressure, cardiac output nor total systemic vascular resistance showed any correlation with irANP levels. There were negative correlations between levels of ANP and mean pulmonary artery pressure which fell from 28.7 to 25.9 mm Hg, pulmonary artery wedge pressure which fell from 6.5 to 4.6 mmHg, and total pulmonary vascular resistance which fell from 489 to 428 dynes s cm-5. There was a small fall in PaCO2 from 6.2 to 5.9 kPa, whilst venous admixture and oxygen delivery both increased non-significantly. CONCLUSIONS--At these pathophysiological concentrations there was evidence that ANP selectively reduced right ventricular afterload. These data support the hypotheses that increased plasma levels of ANP may be beneficial in hypoxic COPD, and that endogenous ANP may ameliorate pulmonary hypertension in humans. PMID:8202879

  19. Ventilatory effects of substance P-saporin lesions in the nucleus tractus solitarii of chronically hypoxic rats

    PubMed Central

    Fu, Zhenxing; Powell, Frank L.

    2011-01-01

    During ventilatory acclimatization to hypoxia (VAH), time-dependent increases in ventilation lower Pco2 levels, and this persists on return to normoxia. We hypothesized that plasticity in the caudal nucleus tractus solitarii (NTS) contributes to VAH, as the NTS receives the first synapse from the carotid body chemoreceptor afferents and also contains CO2-sensitive neurons. We lesioned cells in the caudal NTS containing the neurokinin-1 receptor by microinjecting the neurotoxin saporin conjugated to substance P and measured ventilatory responses in awake, unrestrained rats 18 days later. Lesions did not affect hypoxic or hypercapnic ventilatory responses in normoxic control rats, in contrast to published reports for similar lesions in other central chemosensitive areas. Also, lesions did not affect the hypercapnic ventilatory response in chronically hypoxic rats (inspired Po2 = 90 Torr for 7 days). These results suggest functional differences between central chemoreceptor sites. However, lesions significantly increased ventilation in normoxia or acute hypoxia in chronically hypoxic rats. Hence, chronic hypoxia increases an inhibitory effect of neurokinin-1 receptor neurons in the NTS on ventilatory drive, indicating that these neurons contribute to plasticity during chronic hypoxia, although such plasticity does not explain VAH. PMID:21593425

  20. Transgenic Mouse Model of Chronic Beryllium Disease

    SciTech Connect

    Gordon, Terry

    2009-05-26

    Animal models provide powerful tools for dissecting dose-response relationships and pathogenic mechanisms and for testing new treatment paradigms. Mechanistic research on beryllium exposure-disease relationships is severely limited by a general inability to develop a sufficient chronic beryllium disease animal model. Discovery of the Human Leukocyte Antigen (HLA) - DPB1Glu69 genetic susceptibility component of chronic beryllium disease permitted the addition of this human beryllium antigen presentation molecule to an animal genome which may permit development of a better animal model for chronic beryllium disease. Using FVB/N inbred mice, Drs. Rubin and Zhu, successfully produced three strains of HLA-DPB1 Glu 69 transgenic mice. Each mouse strain contains a haplotype of the HLA-DPB1 Glu 69 gene that confers a different magnitude of odds ratio (OR) of risk for chronic beryllium disease: HLA-DPB1*0401 (OR = 0.2), HLA-DPB1*0201 (OR = 15), HLA-DPB1*1701 (OR = 240). In addition, Drs. Rubin and Zhu developed transgenic mice with the human CD4 gene to permit better transmission of signals between T cells and antigen presenting cells. This project has maintained the colonies of these transgenic mice and tested the functionality of the human transgenes.

  1. Selective depletion of vascular EC-SOD augments chronic hypoxic pulmonary hypertension

    PubMed Central

    Woods, Crystal; Taylor, Joann M.; Benninger, Richard K. P.; Johnson, Richard D.; Villegas, Leah R.; Stenmark, Kurt R.; Harrison, David G.; Majka, Susan M.; Irwin, David; Farrow, Kathryn N.

    2014-01-01

    Excess superoxide has been implicated in pulmonary hypertension (PH). We previously found lung overexpression of the antioxidant extracellular superoxide dismutase (EC-SOD) attenuates PH and pulmonary artery (PA) remodeling. Although comprising a small fraction of total SOD activity in most tissues, EC-SOD is abundant in arteries. We hypothesize that the selective loss of vascular EC-SOD promotes hypoxia-induced PH through redox-sensitive signaling pathways. EC-SODloxp/loxp × Tgcre/SMMHC mice (SMC EC-SOD KO) received tamoxifen to conditionally deplete smooth muscle cell (SMC)-derived EC-SOD. Mice were exposed to hypobaric hypoxia for 35 days, and PH was assessed by right ventricular systolic pressure measurements and right ventricle hypertrophy. Vascular remodeling was evaluated by morphometric analysis and two-photon microscopy for collagen. We examined cGMP content and soluble guanylate cyclase expression and activity in lung, lung phosphodiesterase 5 (PDE5) expression and activity, and expression of endothelial nitric oxide synthase and GTP cyclohydrolase-1 (GTPCH-1), the rate-limiting enzyme in tetrahydrobiopterin synthesis. Knockout of SMC EC-SOD selectively decreased PA EC-SOD without altering total lung EC-SOD. PH and vascular remodeling induced by chronic hypoxia was augmented in SMC EC-SOD KO. Depletion of SMC EC-SOD did not impact content or activity of lung soluble guanylate cyclase or PDE5, yet it blunted the hypoxia-induced increase in cGMP. Although total eNOS was not altered, active eNOS and GTPCH-1 decreased with hypoxia only in SMC EC-SOD KO. We conclude that the localized loss of PA EC-SOD augments chronic hypoxic PH. In addition to oxidative inactivation of NO, deletion of EC-SOD seems to reduce eNOS activity, further compromising pulmonary vascular function. PMID:25326578

  2. Selective depletion of vascular EC-SOD augments chronic hypoxic pulmonary hypertension.

    PubMed

    Nozik-Grayck, Eva; Woods, Crystal; Taylor, Joann M; Benninger, Richard K P; Johnson, Richard D; Villegas, Leah R; Stenmark, Kurt R; Harrison, David G; Majka, Susan M; Irwin, David; Farrow, Kathryn N

    2014-12-01

    Excess superoxide has been implicated in pulmonary hypertension (PH). We previously found lung overexpression of the antioxidant extracellular superoxide dismutase (EC-SOD) attenuates PH and pulmonary artery (PA) remodeling. Although comprising a small fraction of total SOD activity in most tissues, EC-SOD is abundant in arteries. We hypothesize that the selective loss of vascular EC-SOD promotes hypoxia-induced PH through redox-sensitive signaling pathways. EC-SOD(loxp/loxp) × Tg(cre/SMMHC) mice (SMC EC-SOD KO) received tamoxifen to conditionally deplete smooth muscle cell (SMC)-derived EC-SOD. Mice were exposed to hypobaric hypoxia for 35 days, and PH was assessed by right ventricular systolic pressure measurements and right ventricle hypertrophy. Vascular remodeling was evaluated by morphometric analysis and two-photon microscopy for collagen. We examined cGMP content and soluble guanylate cyclase expression and activity in lung, lung phosphodiesterase 5 (PDE5) expression and activity, and expression of endothelial nitric oxide synthase and GTP cyclohydrolase-1 (GTPCH-1), the rate-limiting enzyme in tetrahydrobiopterin synthesis. Knockout of SMC EC-SOD selectively decreased PA EC-SOD without altering total lung EC-SOD. PH and vascular remodeling induced by chronic hypoxia was augmented in SMC EC-SOD KO. Depletion of SMC EC-SOD did not impact content or activity of lung soluble guanylate cyclase or PDE5, yet it blunted the hypoxia-induced increase in cGMP. Although total eNOS was not altered, active eNOS and GTPCH-1 decreased with hypoxia only in SMC EC-SOD KO. We conclude that the localized loss of PA EC-SOD augments chronic hypoxic PH. In addition to oxidative inactivation of NO, deletion of EC-SOD seems to reduce eNOS activity, further compromising pulmonary vascular function. PMID:25326578

  3. Angiotensin II receptor expression and inhibition in the chronically hypoxic rat lung.

    PubMed Central

    Zhao, L.; al-Tubuly, R.; Sebkhi, A.; Owji, A. A.; Nunez, D. J.; Wilkins, M. R.

    1996-01-01

    1. Angiotensin II (AII) binding density and the effect of chronic AII receptor blockade were examined in the rat model of hypoxia-induced pulmonary hypertension. 2. [125I]-[Sar1,Ile2]AII binding capacity was increased in lung membranes from rats exposed to hypoxia (10% fractional inspired O2) for 7 days compared to normal rats (Bmax 108 +/- 12 vs 77 +/- 3 fmol mg-1 protein; P < 0.05), with no significant change in dissociation constant. Competition with specific AII receptor subtype antagonists demonstrated that AT1 is the predominant subtype in both normal and hypoxic lung. 3. Rats treated intravenously with the AT1 antagonist, GR138950C, 1 mg kg-1 day-1 rather than saline alone during 7 days of exposure to hypoxia developed less pulmonary hypertension (pulmonary arterial pressure: 21.3 +/- 1.7 vs 28.3 +/- 1.1 mmHg; P < 0.05), right ventricular hypertrophy (right/left ventricle weight ratio: 0.35 +/- 0.01 vs 0.45 +/- 0.01; P < 0.05) and pulmonary artery remodelling (abundance of thick-walled pulmonary vessels: 9.6 +/- 1.4% vs 20.1 +/- 0.9%; P < 0.05). 4. The reduction in cardiac hypertrophy and pulmonary remodelling with the AT1 antagonist was greater than that achieved by a dose of sodium nitroprusside (SNP) that produced a comparable attenuation of the rise in pulmonary arterial pressure during hypoxia. 5. The data suggest that AII, via the AT1 receptor, has a role in the early pathogenesis of hypoxia-induced pulmonary hypertension in the rat. PMID:8937726

  4. YM155, a selective survivin inhibitor, reverses chronic hypoxic pulmonary hypertension in rats via upregulating voltage-gated potassium channels.

    PubMed

    Fan, Zaiwen; Liu, Bo; Zhang, Shuai; Liu, Huiguo; Li, Yang; Wang, Dong; Liu, Ying; Li, Jian; Wang, Ning; Liu, Yi; Zhang, Bo

    2015-01-01

    To test the hypothesis that chronic hypoxic pulmonary hypertension (CH-PH) is associated with increased survivin and decreased voltage-gated potassium (KV) channels expression in pulmonary arteries, rats were randomized as: normoxia (N); normoxia + YM155, survivin suppressor (NY); hypoxia (H); hypoxia + YM155 (HY). HY group had significantly reduced pulmonary arterial pressure, right ventricular weight and right ventricular hypertrophy compared with H group. Survivin mRNA and protein were detected in pulmonary arteries of rats with CH-PH, but not rats without CH-PH. YM155 downregulated survivin protein and mRNA. KV channel expression and activity were upregulated after YM155 treatment. Survivin may play a role in the pathogenesis of CH-PH. PMID:25856227

  5. Repair and regeneration of tracheal surface epithelium and submucosal glands in a mouse model of hypoxic-ischemic injury

    PubMed Central

    HEGAB, AHMED E.; NICKERSON, DEREK W.; HA, VI LUAN; DARMAWAN, DAPHNE O.; GOMPERTS, BRIGITTE N.

    2012-01-01

    Background and objective The heterotopic syngeneic tracheal transplant mouse model is an acute hypoxic-ischemic injury model that undergoes complete repair and regeneration. We hypothesized that the repair and regeneration process of the surface epithelium and submucosal glands would occur in a reproducible pattern that could be followed by the expression of specific markers of epithelial cell types. Methods We used the syngeneic heterotopic tracheal transplant model to develop a temporal and spatial map of cellular repair and regeneration by examining the tracheal grafts at post-transplant days 1, 3, 5, 7, 10 and 14. We used pulsed BrdU and immunofluorescent staining to identify and follow proliferating and repairing cell populations. Results We confirmed the reproducibility of the injury and repair in the model and we found a distinct sequence of reappearance of the various stem/ progenitor and differentiated cell populations of the tracheal surface epithelium and submucosal glands. In the initial phase, the basal and duct cells that survived the injury proliferated to re-epithelialize the basement membrane with K5 and K14 expressing cells. Then these cells proliferated further and differentiated to restore the function of the epithelium. During this repair process, TROP-2 marked all repairing submucosal gland tubules and ducts. Non-CCSP-expressing serous cells were found to differentiate 4–5 days before Clara, mucus and ciliated cells. Conclusions Improving our understanding of the reparative process of the airway epithelium will allow us to identify cell-specific mechanisms of repair that could be used as novel therapeutic approaches for abnormal repair leading to airway diseases. PMID:22617027

  6. Effect of chronic undernutrition on body mass and mechanical bone quality under normoxic and altitude hypoxic conditions.

    PubMed

    Lezon, Christian; Bozzini, Clarisa; Agûero Romero, Alan; Pinto, Patricia; Champin, Graciela; Alippi, Rosa M; Boyer, Patricia; Bozzini, Carlos E

    2016-05-01

    Both undernutrition and hypoxia exert a negative influence on both growth pattern and bone mechanical properties in developing rats. The present study explored the effects of chronic food restriction on both variables in growing rats exposed to simulated high-altitude hypoxia. Male rats (n 80) aged 28 d were divided into normoxic (Nx) and hypoxic (Hx) groups. Hx rats were exposed to hypobaric air (380 mmHg) in decompression chambers. At T0, Nx and Hx rats were subdivided into four equal subgroups: normoxic control and hypoxic controls, and normoxic growth-restricted and hypoxic growth-restricted received 80 % of the amount of food consumed freely by their respective controls for a 4-week period. Half of these animals were studied at the end of this period (T4). The remaining rats in each group continued under the same environmental conditions, but food was offered ad libitum to explore the type of catch-up growth during 8 weeks. Structural bone properties (strength and stiffness) were evaluated in the right femur midshaft by the mechanical three-point bending test; geometric properties (length, cross-sectional area, cortical mass, bending cross-sectional moment of inertia) and intrinsic properties of the bone tissue (elastic modulus) were measured or derived from appropriate equations. Bone mineralisation was assessed by ash measurement of the left femur. These data indicate that the growth-retarded effects of diminished food intake, induced either by food restriction or hypoxia-related inhibition of appetite, generated the formation of corresponding smaller bones in which subnormal structural and geometric properties were observed. However, they seemed to be appropriate to the body mass of the animals and suggest, therefore, that the bones were not osteopenic. When food restriction was imposed in Hx rats, the combined effects of both variables were additive, inducing a further reduction of bone mass and bone load-carrying capacity. In all cases, the mechanical

  7. Inhibition of protein kinase G activity protects neonatal mouse respiratory network from hyperthermic and hypoxic stress.

    PubMed

    Armstrong, Gary A B; López-Guerrero, Juan J; Dawson-Scully, Ken; Peña, Fernando; Robertson, R Meldrum

    2010-01-22

    In spite of considerable research attention focused on clarifying the mechanisms by which the mammalian respiratory rhythm is generated, little attention has been given to examining how this neuronal circuit can be protected from heat stress. Hyperthermia has a profound effect on neuronal circuits including the circuit that generates breathing in mammals. As temperature of the brainstem increases, respiratory frequency concomitantly rises. If temperature continues to increase respiratory arrest (apnea) and death can occur. Previous research has implicated protein kinase G (PKG) activity in regulating neuronal thermosensitivity of neuronal circuits in invertebrates. Here we examine if pharmacological manipulation of PKG activity in a brainstem slice preparation could alter the thermosensitivity of the fictive neonatal mouse respiratory rhythm. We report a striking effect following alteration of PKG activity in the brainstem such that slices treated with the PKG inhibitor KT5823 recovered fictive respiratory rhythm generation significantly faster than control slices and slices treated with a PKG activator (8-Br-cGMP). Furthermore, slices treated with 8-Br-cGMP arrested fictive respiration at a significantly lower temperature than all other treatment groups. In a separate set of experiments we examined if altered PKG activity could regulate the response of slices to hypoxia by altering the protective switch to fictive gasping. Slices treated with 8-Br-cGMP did not switch to the fictive gasp-like pattern following exposure to hypoxia whereas slices treated with KT5823 did display fictive gasping. We propose that PKG activity inversely regulates the amount of stress the neonatal mammalian respiratory rhythm can endure. PMID:19945442

  8. Chronic sustained hypoxia-induced redox remodeling causes contractile dysfunction in mouse sternohyoid muscle.

    PubMed

    Lewis, Philip; Sheehan, David; Soares, Renata; Varela Coelho, Ana; O'Halloran, Ken D

    2015-01-01

    Chronic sustained hypoxia (CH) induces structural and functional adaptations in respiratory muscles of animal models, however the underlying molecular mechanisms are unclear. This study explores the putative role of CH-induced redox remodeling in a translational mouse model, with a focus on the sternohyoid-a representative upper airway dilator muscle involved in the control of pharyngeal airway caliber. We hypothesized that exposure to CH induces redox disturbance in mouse sternohyoid muscle in a time-dependent manner affecting metabolic capacity and contractile performance. C57Bl6/J mice were exposed to normoxia or normobaric CH (FiO2 = 0.1) for 1, 3, or 6 weeks. A second cohort of animals was exposed to CH for 6 weeks with and without antioxidant supplementation (tempol or N-acetyl cysteine in the drinking water). Following CH exposure, we performed 2D redox proteomics with mass spectrometry, metabolic enzyme activity assays, and cell-signaling assays. Additionally, we assessed isotonic contractile and endurance properties ex vivo. Temporal changes in protein oxidation and glycolytic enzyme activities were observed. Redox modulation of sternohyoid muscle proteins key to contraction, metabolism and cellular homeostasis was identified. There was no change in redox-sensitive proteasome activity or HIF-1α content, but CH decreased phospho-JNK content independent of antioxidant supplementation. CH was detrimental to sternohyoid force- and power-generating capacity and this was prevented by chronic antioxidant supplementation. We conclude that CH causes upper airway dilator muscle dysfunction due to redox modulation of proteins key to function and homeostasis. Such changes could serve to further disrupt respiratory homeostasis in diseases characterized by CH such as chronic obstructive pulmonary disease. Antioxidants may have potential use as an adjunctive therapy in hypoxic respiratory disease. PMID:25941492

  9. Chronic sustained hypoxia-induced redox remodeling causes contractile dysfunction in mouse sternohyoid muscle

    PubMed Central

    Lewis, Philip; Sheehan, David; Soares, Renata; Varela Coelho, Ana; O'Halloran, Ken D.

    2015-01-01

    Chronic sustained hypoxia (CH) induces structural and functional adaptations in respiratory muscles of animal models, however the underlying molecular mechanisms are unclear. This study explores the putative role of CH-induced redox remodeling in a translational mouse model, with a focus on the sternohyoid—a representative upper airway dilator muscle involved in the control of pharyngeal airway caliber. We hypothesized that exposure to CH induces redox disturbance in mouse sternohyoid muscle in a time-dependent manner affecting metabolic capacity and contractile performance. C57Bl6/J mice were exposed to normoxia or normobaric CH (FiO2 = 0.1) for 1, 3, or 6 weeks. A second cohort of animals was exposed to CH for 6 weeks with and without antioxidant supplementation (tempol or N-acetyl cysteine in the drinking water). Following CH exposure, we performed 2D redox proteomics with mass spectrometry, metabolic enzyme activity assays, and cell-signaling assays. Additionally, we assessed isotonic contractile and endurance properties ex vivo. Temporal changes in protein oxidation and glycolytic enzyme activities were observed. Redox modulation of sternohyoid muscle proteins key to contraction, metabolism and cellular homeostasis was identified. There was no change in redox-sensitive proteasome activity or HIF-1α content, but CH decreased phospho-JNK content independent of antioxidant supplementation. CH was detrimental to sternohyoid force- and power-generating capacity and this was prevented by chronic antioxidant supplementation. We conclude that CH causes upper airway dilator muscle dysfunction due to redox modulation of proteins key to function and homeostasis. Such changes could serve to further disrupt respiratory homeostasis in diseases characterized by CH such as chronic obstructive pulmonary disease. Antioxidants may have potential use as an adjunctive therapy in hypoxic respiratory disease. PMID:25941492

  10. Heme oxygenase-1 dependant pathway contributes to protection by tetramethylpyrazine against chronic hypoxic injury on medulla oblongata in rats.

    PubMed

    Ding, Yan; Hou, Xuefei; Chen, Li; Zhou, Hua; Gong, Yanju; Dai, Liqun; Zheng, Yu

    2016-02-15

    Tetramethylpyrazine (TMP), one of the active ingredients of the Chinese herb Lingusticum Wallichii (Chuan Xiong) has been proved to protect the medulla oblongata from chronic hypoxia injury. However, the underlying mechanism remains unclear. The purpose of this study was to determine whether the protective effects of TMP are associated with the heme oxygenase-1 (HO-1) dependant pathway in adult rats. The morphological changes of neurons in the hypoglossal nucleus (12N), the nucleus ambiguus (Amb), the nucleus tractus solitarius (NTS), and the pre-Bötzinger complex (pre-BötC) were investigated by Nissl staining; the malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were measured to evaluate the anti-oxidant effect; some apoptosis parameters, Bax mRNA and Bcl-2 mRNA, were tested; and the double immunochemistry staining of active caspase-3/NeuN was performed. Meanwhile, the HO-1 protein expression and heme oxygenase (HO) activity were examined. Tin-protoporphyrin (SnPP), a potent inhibitor of HO, was used to further confirm the effect of HO-1. We found that TMP ameliorated the neuron loss in 12N, Amb and NTS, the decrease in SOD activity and the increase in MDA content, the decrease in Bcl-2 mRNA of medulla oblongata (P<0.05), and the increase in percentage of apoptotic neurons in Amb (P<0.05) induced by chronic hypoxia. Co-administration with SnPP abolished the beneficial effects above of TMP to some extent (P<0.05). Moreover, TMP significantly increased HO activity and HO-1 protein expression, which was most likely enhanced in the neurons (P<0.05), and co-administration of SnPP reduced these up-regulated effects (P<0.05). This study demonstrated that HO-1 dependant pathway may be involved in the protective action of TMP against chronic hypoxic damage on medulla oblongata in the rats. PMID:26810525

  11. Color discrimination under chronic hypoxic conditions (simulated climb "Everest-Comex 97").

    PubMed

    Bouquet, C; Gardette, B; Gortan, C; Therme, P; Abraini, J H

    2000-02-01

    Hypoxia is known to alter visual functions. In the present study, the effects of chronic hypobaric hypoxia upon visual color discrimination were studied in 8 subjects participating in a simulated climb from sea level (PO2 = 210 hPa) to 8,848 m (PO2 = 70 hPa) over a 31-day period of confinement in a decompression chamber ('Everst-Comex 97'). During these investigations, the subjects were required to discriminate between colors of different hue in the red, blue, and green ranges. Alterations in color discrimination increased slightly but significantly as altitude increased. Impairments occurred mainly in the red and blue ranges. In addition, our results further indicate that color discrimination would be affected only when a minimum threshold of difference between color stimuli is not present. Methodological and physiological implications are discussed. PMID:10769896

  12. Expression Profiling Reveals Novel Hypoxic Biomarkers in Peripheral Blood of Adult Mice Exposed to Chronic Hypoxia

    PubMed Central

    Zeiger, Ulrike; Khurana, Tejvir S.

    2012-01-01

    Hypoxia induces a myriad of changes including an increase in hematocrit due to erythropoietin (EPO) mediated erythropoiesis. While hypoxia is of importance physiologically and clinically, lacunae exist in our knowledge of the systemic and temporal changes in gene expression occurring in blood during the exposure and recovery from hypoxia. To identify these changes expression profiling was conducted on blood obtained from cohorts of C57Bl-10 wild type mice that were maintained at normoxia (NX), exposed for two weeks to normobaric chronic hypoxia (CH) or two weeks of CH followed by two weeks of normoxic recovery (REC). Using stringent bioinformatic cut-offs (0% FDR, 2 fold change cut-off), 230 genes were identified and separated into four distinct temporal categories. Class I) contained 1 transcript up-regulated in both CH and REC; Class II) contained 202 transcripts up-regulated in CH but down-regulated after REC; Class III) contained 9 transcripts down-regulated both in CH and REC; Class IV) contained 18 transcripts down-regulated after CH exposure but up-regulated after REC. Profiling was independently validated and extended by analyzing expression levels of selected genes as novel biomarkers from our profile (e.g. spectrin alpha-1, ubiquitin domain family-1 and pyrroline-5-carboxylate reductase-1) by performing qPCR at 7 different time points during CH and REC. Our identification and characterization of these genes define transcriptome level changes occurring during chronic hypoxia and normoxic recovery as well as novel blood biomarkers that may be useful in monitoring a variety of physiological and pathological conditions associated with hypoxia. PMID:22629407

  13. Expression profiling reveals novel hypoxic biomarkers in peripheral blood of adult mice exposed to chronic hypoxia.

    PubMed

    Mosqueira, Matias; Willmann, Gabriel; Zeiger, Ulrike; Khurana, Tejvir S

    2012-01-01

    Hypoxia induces a myriad of changes including an increase in hematocrit due to erythropoietin (EPO) mediated erythropoiesis. While hypoxia is of importance physiologically and clinically, lacunae exist in our knowledge of the systemic and temporal changes in gene expression occurring in blood during the exposure and recovery from hypoxia. To identify these changes expression profiling was conducted on blood obtained from cohorts of C57Bl-10 wild type mice that were maintained at normoxia (NX), exposed for two weeks to normobaric chronic hypoxia (CH) or two weeks of CH followed by two weeks of normoxic recovery (REC). Using stringent bioinformatic cut-offs (0% FDR, 2 fold change cut-off), 230 genes were identified and separated into four distinct temporal categories. Class I) contained 1 transcript up-regulated in both CH and REC; Class II) contained 202 transcripts up-regulated in CH but down-regulated after REC; Class III) contained 9 transcripts down-regulated both in CH and REC; Class IV) contained 18 transcripts down-regulated after CH exposure but up-regulated after REC. Profiling was independently validated and extended by analyzing expression levels of selected genes as novel biomarkers from our profile (e.g. spectrin alpha-1, ubiquitin domain family-1 and pyrroline-5-carboxylate reductase-1) by performing qPCR at 7 different time points during CH and REC. Our identification and characterization of these genes define transcriptome level changes occurring during chronic hypoxia and normoxic recovery as well as novel blood biomarkers that may be useful in monitoring a variety of physiological and pathological conditions associated with hypoxia. PMID:22629407

  14. HIF-VEGF pathways are critical for chronic otitis media in Junbo and Jeff mouse mutants.

    PubMed

    Cheeseman, Michael T; Tyrer, Hayley E; Williams, Debbie; Hough, Tertius A; Pathak, Paras; Romero, Maria R; Hilton, Helen; Bali, Sulzhan; Parker, Andrew; Vizor, Lucie; Purnell, Tom; Vowell, Kate; Wells, Sara; Bhutta, Mahmood F; Potter, Paul K; Brown, Steve D M

    2011-10-01

    Otitis media with effusion (OME) is the commonest cause of hearing loss in children, yet the underlying genetic pathways and mechanisms involved are incompletely understood. Ventilation of the middle ear with tympanostomy tubes is the commonest surgical procedure in children and the best treatment for chronic OME, but the mechanism by which they work remains uncertain. As hypoxia is a common feature of inflamed microenvironments, moderation of hypoxia may be a significant contributory mechanism. We have investigated the occurrence of hypoxia and hypoxia-inducible factor (HIF) mediated responses in Junbo and Jeff mouse mutant models, which develop spontaneous chronic otitis media. We found that Jeff and Junbo mice labeled in vivo with pimonidazole showed cellular hypoxia in inflammatory cells in the bulla lumen, and in Junbo the middle ear mucosa was also hypoxic. The bulla fluid inflammatory cell numbers were greater and the upregulation of inflammatory gene networks were more pronounced in Junbo than Jeff. Hif-1α gene expression was elevated in bulla fluid inflammatory cells, and there was upregulation of its target genes including Vegfa in Junbo and Jeff. We therefore investigated the effects in Junbo of small-molecule inhibitors of VEGFR signaling (PTK787, SU-11248, and BAY 43-9006) and destabilizing HIF by inhibiting its chaperone HSP90 with 17-DMAG. We found that both classes of inhibitor significantly reduced hearing loss and the occurrence of bulla fluid and that VEGFR inhibitors moderated angiogenesis and lymphangiogenesis in the inflamed middle ear mucosa. The effectiveness of HSP90 and VEGFR signaling inhibitors in suppressing OM in the Junbo model implicates HIF-mediated VEGF as playing a pivotal role in OM pathogenesis. Our analysis of the Junbo and Jeff mutants highlights the role of hypoxia and HIF-mediated pathways, and we conclude that targeting molecules in HIF-VEGF signaling pathways has therapeutic potential in the treatment of chronic OM. PMID

  15. Understanding Hypoxic Drive and the Release of Hypoxic Vasoconstriction.

    PubMed

    Inkrott, Jon C

    2016-01-01

    Understanding the hypoxic drive and release of hypoxic vasoconstriction in the chronic obstructive pulmonary disease population can be somewhat confusing and misunderstood. Furthermore, the hypoxic drive theory is one in which there really is no scientific evidence to support and yet continues to prosper in every aspect of care in regard to the chronic lung patient, from prehospital all the way to intensive care unit and home care therapy. This subject review will hopefully enhance some understanding of what exactly goes on with these patients and the importance of providing oxygen when it is desperately needed. PMID:27393755

  16. Withdrawal severity after chronic intermittent ethanol in inbred mouse strains

    PubMed Central

    Metten, Pamela; Sorensen, Michelle L.; Cameron, Andy Jade; Yu, Chia-Hua; Crabbe, John C.

    2010-01-01

    Background To study withdrawal, ethanol is usually administered chronically without interruption. However, interest has recurred in models of episodic exposure. Increasing evidence suggests that chronic intermittent exposure to ethanol leads to a sensitization effect in both withdrawal severity and in ethanol consumption. The goal of the present study was to examine mouse inbred strain differences in withdrawal severity following chronic intermittent exposure using the handling induced convulsion as the behavioral endpoint. We also sought to compare the withdrawal responses of inbred strains across acute, chronic continuous, and chronic intermittent exposure regimens. Methods Male mice from 15 standard inbred strains were exposed to ethanol vapor for 16 hours each day for 3 days and removed to an air chamber during the intervening 8 hours. Mice in the control groups were handled the same, except that they were exposed only to air. Daily blood ethanol concentrations were averaged for each mouse to estimate total dose of ethanol experienced. Results Across strains, mice had an average daily blood ethanol concentration (BEC) of 1.45 ± 0.02 mg/ml and we restricted the range of this value to 1.00 to 2.00 mg/ml. To evaluate strain differences, we divided data into two dose groups based on BEC, Low Dose (1.29 ± 0.1 mg/ml) and High Dose (1.71 ± 0.02 mg/ml). After the third inhalation exposure, ethanol- and air-exposed groups were tested hourly for handling-induced convulsions for 10 hr and at hr 24 and 25. Strains differed markedly in the severity of withdrawal (after subtraction of air control values) in both dose groups. Conclusion The chronic intermittent exposure paradigm is sufficient to elicit differential withdrawal responses across nearly all strains. Data from the High Dose groups correlated well with withdrawal data derived from prior acute (single high dose) and chronic continuous (for 72 hrs) ethanol withdrawal studies, supporting the influence of common

  17. Chronic Myeloid Leukemia (CML) Mouse Model in Translational Research.

    PubMed

    Peng, Cong; Li, Shaoguang

    2016-01-01

    Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by increased proliferation of granulocytic cells without the loss of their capability to differentiate. CML is a clonal disease, originated at the level of Hematopoietic Stem Cells with the Philadelphia chromosome resulting from a reciprocal translocation between the chromosomes 9 and 22t(9;22)-(q34;q11). This translocation produces a fusion gene known as BCR-ABL which acquires uncontrolled tyrosine kinase activity, constantly turning on its downstream signaling molecules/pathways, and promoting proliferation of leukemia cell through anti-apoptosis and acquisition of additional mutations. To evaluate the role of each critical downstream signaling molecule of BCR-ABL and test therapeutic drugs in vivo, it is important to use physiological mouse disease models. Here, we describe a mouse model of CML induced by BCR-ABL retrovirus (MSCV-BCR-ABL-GFP; MIG-BCR-ABL) and how to use this model in translational research.Moreover, to expand the application of this retrovirus induced CML model in a lot of conditional knockout mouse strain, we modified this vector to a triple gene coexpression vector in which we can co-express BCR-ABL, GFP, and a third gene which will be tested in different systems. To apply this triple gene system in conditional gene knockout strains, we can validate the CML development in the knockout mice and trace the leukemia cell following the GFP marker. In this protocol, we also describe how we utilize this triple gene system to prove the function of Pten as a tumor suppressor in leukemogenesis. Overall, this triple gene system expands our research spectrum in current conditional gene knockout strains and benefits our CML translational research. PMID:27150093

  18. Pulmonary Macrophages Attenuate Hypoxic Pulmonary Vasoconstriction via β3AR/iNOS Pathway in Rats Exposed to Chronic Intermittent Hypoxia

    PubMed Central

    Nagai, Hisashi; Kuwahira, Ichiro; Schwenke, Daryl O.; Tsuchimochi, Hirotsugu; Nara, Akina; Ogura, Sayoko; Sonobe, Takashi; Inagaki, Tadakatsu; Fujii, Yutaka; Yamaguchi, Rutsuko; Wingenfeld, Lisa; Umetani, Keiji; Shimosawa, Tatsuo; Yoshida, Ken-ichi; Uemura, Koichi; Pearson, James T.; Shirai, Mikiyasu

    2015-01-01

    Chronic intermittent hypoxia (IH) induces activation of the sympathoadrenal system, which plays a pivotal role in attenuating hypoxic pulmonary vasoconstriction (HPV) via central β1-adrenergic receptors (AR) (brain) and peripheral β2AR (pulmonary arteries). Prolonged hypercatecholemia has been shown to upregulate β3AR. However, the relationship between IH and β3AR in the modification of HPV is unknown. It has been observed that chronic stimulation of β3AR upregulates inducible nitric oxide synthase (iNOS) in cardiomyocytes and that IH exposure causes expression of iNOS in RAW264.7 macrophages. iNOS has been shown to have the ability to dilate pulmonary vessels. Hence, we hypothesized that chronic IH activates β3AR/iNOS signaling in pulmonary macrophages, leading to the promotion of NO secretion and attenuated HPV. Sprague-Dawley rats were exposed to IH (3-min periods of 4–21% O2) for 8 h/d for 6 weeks. The urinary catecholamine concentrations of IH rats were high compared with those of controls, indicating activation of the sympathoadrenal system following chronic IH. Interestingly, chronic IH induced the migration of circulating monocytes into the lungs and the predominant increase in the number of pro-inflammatory pulmonary macrophages. In these macrophages, both β3AR and iNOS were upregulated and stimulation of the β3AR/iNOS pathway in vitro caused them to promote NO secretion. Furthermore, in vivo synchrotron radiation microangiography showed that HPV was significantly attenuated in IH rats and the attenuated HPV was fully restored by blockade of β3AR/iNOS pathway or depletion of pulmonary macrophages. These results suggest that circulating monocyte-derived pulmonary macrophages attenuate HPV via activation of β3AR/iNOS signaling in chronic IH. PMID:26132492

  19. Cognitive performance during a simulated climb of Mount Everest: implications for brain function and central adaptive processes under chronic hypoxic stress.

    PubMed

    Abraini, J H; Bouquet, C; Joulia, F; Nicolas, M; Kriem, B

    1998-07-01

    High altitude is characterized by hypoxic environmental conditions and is well known to induce both physiological and psychological disturbances. In the present study, called ”Everest-Comex 97”, the authors investigated the effects of high altitude on the psychosensorimotor and reasoning processes of eight climbers participating in a simulated climb from sea level to 8,848 m over a 31-day period of confinement in a decompression chamber. Tests of visual reaction time, psychomotor ability, and number ordination were used. The climbers’ data were compared with data from a similar laboratory study at sea level in control subjects. Continued testing of the control subjects at sea level clearly led to learning effects and improvement of performance in psychomotor ability and number ordination. In the climbers, similar learning effects occurred up to an altitude of 5,500–6,500 m. With further increases in altitude, the climbers’ psychomotor performance and mental efficiency deteriorated progressively, leading to significant differences in psychomotor ability and mental efficiency between control subjects and climbers (9 and 13% respectively at 8,000 m and 17.5 and 16.5% respectively at 8,848 m). Three days (72 h) after the climbers had returned to sea level, their mental and psychomotor performances were still significantly lower than those of control subjects (by approximately 10%). In contrast, visual reaction time showed no significant changes in either climbers or control subjects. It is suggested that chronic hypoxic stress could alter selectively mental learning processes, i.e. explicit, rather than implicit (stimulus-response learning processes) memory and cortico-limbic rather than basal ganglia-sensorimotor system function. PMID:9683728

  20. Amelioration of ER stress by 4-phenylbutyric acid reduces chronic hypoxia induced cardiac damage and improves hypoxic tolerance through upregulation of HIF-1α.

    PubMed

    Jain, Kanika; Suryakumar, Geetha; Ganju, Lilly; Singh, Shashi Bala

    2016-08-01

    While endoplasmic reticulum (ER) stress has been observed in several human diseases, few studies have reported the involvement of ER stress in chronic hypoxia (CH) induced cardiac damage. Hypoxia, such as that prevalent at high altitude (HA), forms the underlying cause of several maladies including cardiovascular diseases. While the role of hypoxia inducible factor-1 (HIF-1α) in the adaptive responses to hypoxia is known, the role of the unfolded protein response (UPR) is only recently being explored in the HA pathophysiologies. The present study investigates the effect of ER stress modulation on CH mediated injury and the cardioprotective action of 4-phenylbutyric acid (PBA) in enhancing survival response under hypoxia. Here, we observed that exposure of rats, for 1, 7 and 14days CH to a simulated altitude of 7620m, led to cardiac hypertrophy and significant protein oxidation. This induced the activation of UPR signaling mechanisms, mediated by PERK, IRE1α and ATF6. By 14days, there was a marked upregulation of apoptosis, evident in increased CHOP and caspase-3/9 activity. PBA reduced CH induced right ventricular enlargement and apoptosis. Further, in contrast to tunicamycin, PBA considerably enhanced hypoxic tolerance. An elevation in the level of antioxidant enzymes, HIF-1α and its regulated proteins (HO-1, GLUT-1) was observed in the PBA administered animals, along with a concomitant suppression of UPR markers. Our study thus emphasizes upon the attenuation of ER stress by PBA as a mechanism to diminish CH induced cardiac injury and boost hypoxic survival, providing an insight into the novel relationship between the HIF-1α and UPR under hypoxia. PMID:27058435

  1. Impaired gait pattern as a sensitive tool to assess hypoxic brain damage in a novel mouse model of atherosclerotic plaque rupture.

    PubMed

    Roth, Lynn; Van Dam, Debby; Van der Donckt, Carole; Schrijvers, Dorien M; Lemmens, Katrien; Van Brussel, Ilse; De Deyn, Peter P; Martinet, Wim; De Meyer, Guido R Y

    2015-02-01

    Apolipoprotein E deficient (ApoE(-/-)) mice with a heterozygous mutation in the fibrillin-1 gene (Fbn1(C1039G+/-)) show spontaneous atherosclerotic plaque ruptures, disturbances in cerebral flow and sudden death when fed a Western-type diet (WD). The present study focused on motor coordination and spatial learning of ApoE(-/-) Fbn1(C1039G+/-) mice on WD for 20 weeks (n=21). ApoE(-/-) mice on WD (n=24) and ApoE(-/-) Fbn1(C1039G+/-) mice on normal diet (ND, n=21) served as controls. Starting from 10 weeks of diet, coordination was assessed every two weeks by the following tests: gait analysis, stationary beam, wire suspension and accelerating rotarod. The Morris water maze test was performed after 13 weeks of diet to study spatial learning. At the end of the experiment (20 weeks of WD), the mice were sacrificed and the brachiocephalic artery and brain were isolated. From 12 weeks onward, gait analysis of ApoE(-/-) Fbn1(C1039G+/-) mice on WD revealed a progressive increase in track width as compared to ApoE(-/-) mice on WD and ApoE(-/-) Fbn1(C1039G+/-) mice on ND (at 20 weeks: 29.8±0.6 mm vs. 25.8±0.4 mm and 26.0±0.5 mm). Moreover, the stationary beam test showed a decrease in motor coordination of ApoE(-/-) Fbn1(C1039G+/-) mice on WD at 18 and 20 weeks. The wire suspension test and accelerating rotarod could not detect signs of motor impairment. Spatial learning was also not affected. Histological analysis of the brachiocephalic artery showed larger and more stenotic plaques in ApoE(-/-) Fbn1(C1039G+/-) mice on WD. Furthermore, the parietal cortex of ApoE(-/-) Fbn1(C1039G+/-) mice on WD showed pyknotic nuclei as a sign of hypoxia and the percentage of pyknosis correlated with track width. In conclusion, gait analysis may be an efficient method for analyzing hypoxic brain damage in the ApoE(-/-) Fbn1(C1039G+/-) mouse model. This test could be of value to assess the effect of potential anti-atherosclerotic therapies in mice. PMID:25449385

  2. Evidence of hypoxic tolerance in weak upper airway muscle from young mdx mice.

    PubMed

    Burns, David P; O'Halloran, Ken D

    2016-06-01

    Duchenne muscular dystrophy (DMD) is a genetic disease characterised by deficiency in the protein dystrophin. The respiratory system is weakened and patients suffer from sleep disordered breathing and hypoventilation culminating in periods of hypoxaemia. We examined the effects of an acute (6h) hypoxic stress on sternohyoid muscle function (representative pharyngeal dilator). 8 week old male, wild-type (WT; C57BL/10ScSnJ; n=18) and mdx (C57BL/10ScSn-Dmd(mdx)/J; n=16) mice were exposed to sustained hypoxia (FIO2=0.10) or normoxia. Muscle functional properties were examined ex vivo. Additional WT (n=5) and mdx (n=5) sternohyoid muscle was exposed to an anoxic challenge. Sternohyoid dysfunction was observed in mdx mice with significant reductions in force and power. Following exposure to the acute in vivo hypoxic stress, WT sternohyoid muscle showed evidence of functional impairment (reduced force, work and power). Conversely, mdx sternohyoid showed an apparent tolerance to the acute hypoxic stress. This tolerance was not maintained for mdx following a severe hypoxic stress. A dysfunctional upper airway muscle phenotype is present at 8 weeks of age in the mdx mouse, which may have implications for the control of airway patency in DMD. Hypoxic tolerance in mdx respiratory muscle is suggestive of adaptation to chronic hypoxia, which could be present due to respiratory morbidity. We speculate a role for hypoxia in mdx respiratory muscle morbidity. PMID:26691169

  3. A New Mouse Model That Spontaneously Develops Chronic Liver Inflammation and Fibrosis

    PubMed Central

    Fransén-Pettersson, Nina; Duarte, Nadia; Nilsson, Julia; Lundholm, Marie; Mayans, Sofia; Larefalk, Åsa; Hannibal, Tine D.; Hansen, Lisbeth; Schmidt-Christensen, Anja; Ivars, Fredrik; Cardell, Susanna; Palmqvist, Richard; Rozell, Björn

    2016-01-01

    Here we characterize a new animal model that spontaneously develops chronic inflammation and fibrosis in multiple organs, the non-obese diabetic inflammation and fibrosis (N-IF) mouse. In the liver, the N-IF mouse displays inflammation and fibrosis particularly evident around portal tracts and central veins and accompanied with evidence of abnormal intrahepatic bile ducts. The extensive cellular infiltration consists mainly of macrophages, granulocytes, particularly eosinophils, and mast cells. This inflammatory syndrome is mediated by a transgenic population of natural killer T cells (NKT) induced in an immunodeficient NOD genetic background. The disease is transferrable to immunodeficient recipients, while polyclonal T cells from unaffected syngeneic donors can inhibit the disease phenotype. Because of the fibrotic component, early on-set, spontaneous nature and reproducibility, this novel mouse model provides a unique tool to gain further insight into the underlying mechanisms mediating transformation of chronic inflammation into fibrosis and to evaluate intervention protocols for treating conditions of fibrotic disorders. PMID:27441847

  4. Resveratrol Neuroprotection in a Chronic Mouse Model of Multiple Sclerosis

    PubMed Central

    Fonseca-Kelly, Zoe; Nassrallah, Mayssa; Uribe, Jorge; Khan, Reas S.; Dine, Kimberly; Dutt, Mahasweta; Shindler, Kenneth S.

    2012-01-01

    Resveratrol is a naturally occurring polyphenol that activates SIRT1, an NAD-dependent deacetylase. SRT501, a pharmaceutical formulation of resveratrol with enhanced systemic absorption, prevents neuronal loss without suppressing inflammation in mice with relapsing experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis (MS). In contrast, resveratrol has been reported to suppress inflammation in chronic EAE, although neuroprotective effects were not evaluated. The current studies examine potential neuroprotective and immunomodulatory effects of resveratrol in chronic EAE induced by immunization with myelin oligodendroglial glycoprotein peptide in C57/Bl6 mice. Effects of two distinct formulations of resveratrol administered daily orally were compared. Resveratrol delayed the onset of EAE compared to vehicle-treated EAE mice, but did not prevent or alter the phenotype of inflammation in spinal cords or optic nerves. Significant neuroprotective effects were observed, with higher numbers of retinal ganglion cells found in eyes of resveratrol-treated EAE mice with optic nerve inflammation. Results demonstrate that resveratrol prevents neuronal loss in this chronic demyelinating disease model, similar to its effects in relapsing EAE. Differences in immunosuppression compared with prior studies suggest that immunomodulatory effects may be limited and may depend on specific immunization parameters or timing of treatment. Importantly, neuroprotective effects can occur without immunosuppression, suggesting a potential additive benefit of resveratrol in combination with anti-inflammatory therapies for MS. PMID:22654783

  5. Chronic ethanol exposure inhibits distraction osteogenesis in a mouse model: Role of the TNF signaling axis

    SciTech Connect

    Wahl, Elizabeth C.; Aronson, James; Liu, Lichu; Liu, Zhendong; Perrien, Daniel S.; Skinner, Robert A.; Badger, Thomas M.; Ronis, Martin J.J.; Lumpkin, Charles K. . E-mail: lumpkincharlesk@uams.edu

    2007-05-01

    Tumor necrosis factor-alpha (TNF-{alpha}) is an inflammatory cytokine that modulates osteoblastogenesis. In addition, the demonstrated inhibitory effects of chronic ethanol exposure on direct bone formation in rats are hypothetically mediated by TNF-{alpha} signaling. The effects in mice are unreported. Therefore, we hypothesized that in mice (1) administration of a soluble TNF receptor 1 derivative (sTNF-R1) would protect direct bone formation during chronic ethanol exposure, and (2) administration of recombinant mouse TNF-{alpha} (rmTNF-{alpha}) to ethanol naive mice would inhibit direct bone formation. We utilized a unique model of limb lengthening (distraction osteogenesis, DO) combined with liquid diets to measure chronic ethanol's effects on direct bone formation. Chronic ethanol exposure resulted in increased marrow TNF, IL-1, and CYP 2E1 RNA levels in ethanol-treated vs. control mice, while no significant weight differences were noted. Systemic administration of sTNF-R1 during DO (8.0 mg/kg/2 days) to chronic ethanol-exposed mice resulted in enhanced direct bone formation as measured radiologically and histologically. Systemic rmTNF-{alpha} (10 {mu}g/kg/day) administration decreased direct bone formation measures, while no significant weight differences were noted. We conclude that chronic ethanol-associated inhibition of direct bone formation is mediated to a significant extent by the TNF signaling axis in a mouse model.

  6. A Mouse Model for Pathogen-induced Chronic Inflammation at Local and Systemic Sites

    PubMed Central

    Slocum, Connie S.; Weinberg, Ellen O.; Hua, Ning; Gudino, Cynthia V.; Hamilton, James A.; Genco, Caroline A.

    2014-01-01

    Chronic inflammation is a major driver of pathological tissue damage and a unifying characteristic of many chronic diseases in humans including neoplastic, autoimmune, and chronic inflammatory diseases. Emerging evidence implicates pathogen-induced chronic inflammation in the development and progression of chronic diseases with a wide variety of clinical manifestations. Due to the complex and multifactorial etiology of chronic disease, designing experiments for proof of causality and the establishment of mechanistic links is nearly impossible in humans. An advantage of using animal models is that both genetic and environmental factors that may influence the course of a particular disease can be controlled. Thus, designing relevant animal models of infection represents a key step in identifying host and pathogen specific mechanisms that contribute to chronic inflammation. Here we describe a mouse model of pathogen-induced chronic inflammation at local and systemic sites following infection with the oral pathogen Porphyromonas gingivalis, a bacterium closely associated with human periodontal disease. Oral infection of specific-pathogen free mice induces a local inflammatory response resulting in destruction of tooth supporting alveolar bone, a hallmark of periodontal disease. In an established mouse model of atherosclerosis, infection with P. gingivalis accelerates inflammatory plaque deposition within the aortic sinus and innominate artery, accompanied by activation of the vascular endothelium, an increased immune cell infiltrate, and elevated expression of inflammatory mediators within lesions. We detail methodologies for the assessment of inflammation at local and systemic sites. The use of transgenic mice and defined bacterial mutants makes this model particularly suitable for identifying both host and microbial factors involved in the initiation, progression, and outcome of disease. Additionally, the model can be used to screen for novel therapeutic strategies

  7. Chronic brief restraint decreases in vivo binding of benzodiazepine receptor ligand to mouse brain.

    PubMed

    Mosaddeghi, M; Burke, T F; Moerschbaecher, J M

    1993-01-01

    This study examines the effects of chronic brief restraint on in vivo benzodiazepine (BZD) receptor binding in mouse brain. Three groups of mice were used. Mice in group 1 were neither restrained nor injected (ACUTE control). Mice in group 2 were restrained for 5-6 s by grabbing the back skin and holding the subject upside-down at a 45 degrees angle as if to be injected (CHRONIC SHAM control) for 7 d. Mice in group 3 (CHRONIC SALINE) received daily single intraperitoneal (ip) injections of saline (5 mL/kg) for 7 d. On d 8 BZD receptors were labeled in vivo by administration of 3 microCi [3H]flumazenil (ip). The levels of ligand bound in vivo to cerebral cortex (CX), cerebellum (CB), brain stem (BS), striatum (ST), hippocampus (HP), and hypothalamus (HY) were determined. Results indicated that the level of binding was significantly (p < 0.01) lower by 30-50% (depending on the brain region) in saline-injected or sham control groups compared to acute control animals. Furthermore, the values for sham control were similar to the saline-treated group. Our data suggest that exposure to chronic mild restraint produces a decrease in in vivo binding of [3H]flumazenil in mouse brain and supports the hypothesis that chronic mild stress produces a decrease in BZD receptor binding sites. PMID:8385464

  8. Chronic Toxoplasmosis Modulates the Induction of Contact Hypersensitivity by TNCB in Mouse Model

    PubMed Central

    Yang, Zhaoshou; Ahn, Hye-Jin; Nam, Ho-Woo

    2015-01-01

    Mouse models of chronic toxoplasmosis and atopic dermatitis (AD) were combined to clarify the effect of opportunistic Toxoplasma gondii infection on the development of AD. AD was induced as a chronic contact hypersensitivity (CHS) with repeated challenge of 2,4,6-trinitro-1-chlorobenzene (TNCB) on the dorsal skin of mice. TNCB induced skin thickness increases in both normal and toxoplasmic mice. The changing patterns were different from the sigmoidal which saturated at 20 days in normal mice to the convex saturated at 12 days in toxoplasmic mice with the crossing at 18 days. Compared to normal mice, toxoplasmic mice presented CHS more severely in earlier times and then moderately in later times. These data suggest that host immune modification by T. gondii infection enhances CHS in early times of atopic stimulation but soothes the reaction of CHS in later times in mouse model. PMID:26797445

  9. Early microglia activation in a mouse model of chronic glaucoma

    PubMed Central

    Bosco, Alejandra; Steele, Michael R.; Vetter, Monica L.

    2014-01-01

    Changes in microglial cell activation and distribution are associated with neuronal decline in the CNS, particularly under pathological conditions. Activated microglia converge on the initial site of axonal degeneration in human glaucoma, yet, their part in its pathophysiology remains unresolved. To begin with, it is unknown whether microglia activation precedes or is a late consequence of retinal ganglion cell (RGC) neurodegeneration. Here, we address this critical element in DBA/2J (D2) mice, an established model of chronic inherited glaucoma, using as a control the congenic substrain DBA/2J Gpnmb+/SjJ (D2G), which is not affected by glaucoma. We analyzed the spatial distribution and timecourse of microglial changes in the retina, as well as within the proximal optic nerve prior to and throughout ages when neurodegeneration has been reported. Exclusively in D2 mice, we detected early microglia clustering in the inner central retina and unmyelinated optic nerve regions, with microglia activation peaking by 3 months of age. Between 5 and 8 months of age, activated microglia persisted and concentrated in the optic disc, but also localized to the retinal periphery. Collectively, our findings suggest microglia activation is an early alteration in the retina and optic nerve in D2 glaucoma, potentially contributing to disease onset or progression. Ultimately, detection of microglial activation may have value in early disease diagnosis, while modulation of microglial responses may alter disease progression. PMID:21246546

  10. Acute molecular response of mouse hindlimb muscles to chronic stimulation

    PubMed Central

    Jayaraman, R. C.; Bombach, K. L.; Ankrapp, D. P.; Krill-Burger, J. M.; Sciulli, C. M.; Petrosko, P.; Wiseman, R. W.

    2009-01-01

    Stimulation of the mouse hindlimb via the sciatic nerve was performed for a 4-h period to investigate acute muscle gene activation in a model of muscle phenotype conversion. Initial force production (1.6 ± 0.1 g/g body wt) declined 45% within 10 min and was maintained for the remainder of the experiment. Force returned to initial levels upon study completion. An immediate-early growth response was present in the extensor digitorum longus (EDL) muscle (FOS, JUN, activating transcription factor 3, and musculoaponeurotic fibrosarcoma oncogene) with a similar but attenuated pattern in the soleus muscle. Transcript profiles showed decreased fast fiber-specific mRNA (myosin heavy chains 2A and 2B, fast troponins T3 and I, α-tropomyosin, muscle creatine kinase, and parvalbumin) and increased slow transcripts (myosin heavy chain-1β/slow, troponin C slow, and tropomyosin 3y) in the EDL versus soleus muscles. Histological analysis of the EDL revealed glycogen depletion without inflammatory cell infiltration in stimulated versus control muscles, whereas ultrastructural analysis showed no evidence of myofiber damage after stimulation. Multiple fiber type-specific transcription factors (tea domain family member 1, nuclear factor of activated T cells 1, peroxisome proliferator-activated receptor-γ coactivator-1α and -β, circadian locomotor output cycles kaput, and hypoxia-inducible factor-1α) increased in the EDL along with transcription factors characteristic of embryogenesis (Kruppel-like factor 4; SRY box containing 17; transcription factor 15; PBX/knotted 1 homeobox 1; and embryonic lethal, abnormal vision). No established in vivo satellite cell markers or genes activated in our parallel experiments of satellite cell proliferation in vitro (cyclins A2, B2, C, and E1 and MyoD) were differentially increased in the stimulated muscles. These results indicated that the molecular onset of fast to slow phenotype conversion occurred in the EDL within 4 h of stimulation

  11. Pericytes contribute to airway remodeling in a mouse model of chronic allergic asthma.

    PubMed

    Johnson, Jill R; Folestad, Erika; Rowley, Jessica E; Noll, Elisa M; Walker, Simone A; Lloyd, Clare M; Rankin, Sara M; Pietras, Kristian; Eriksson, Ulf; Fuxe, Jonas

    2015-04-01

    Myofibroblast accumulation, subepithelial fibrosis, and vascular remodeling are complicating features of chronic asthma, but the mechanisms are not clear. Platelet-derived growth factors (PDGFs) regulate the fate and function of various mesenchymal cells and have been implicated as mediators of lung fibrosis. However, it is not known whether PDGF-BB signaling via PDGFRβ, which is critical for the recruitment of pericytes to blood vessels, plays a role in airway remodeling in chronic asthma. In the present study, we used a selective PDGFRβ inhibitor (CP-673451) to investigate the role of PDGFRβ signaling in the development of airway remodeling and lung dysfunction in an established mouse model of house dust mite-induced chronic allergic asthma. Unexpectedly, we found that pharmacological inhibition of PDGFRβ signaling in the context of chronic aeroallergen exposure led to exacerbated lung dysfunction and airway smooth muscle thickening. Further studies revealed that the inflammatory response to aeroallergen challenge in mice was associated with decreased PDGF-BB expression and the loss of pericytes from the airway microvasculature. In parallel, cells positive for pericyte markers accumulated in the subepithelial region of chronically inflamed airways. This process was exacerbated in animals treated with CP-673451. The results indicate that perturbed PDGF-BB/PDGFRβ signaling and pericyte accumulation in the airway wall may contribute to airway remodeling in chronic allergic asthma. PMID:25637607

  12. Pericytes contribute to airway remodeling in a mouse model of chronic allergic asthma

    PubMed Central

    Folestad, Erika; Rowley, Jessica E.; Noll, Elisa M.; Walker, Simone A.; Lloyd, Clare M.; Rankin, Sara M.; Pietras, Kristian; Eriksson, Ulf; Fuxe, Jonas

    2015-01-01

    Myofibroblast accumulation, subepithelial fibrosis, and vascular remodeling are complicating features of chronic asthma, but the mechanisms are not clear. Platelet-derived growth factors (PDGFs) regulate the fate and function of various mesenchymal cells and have been implicated as mediators of lung fibrosis. However, it is not known whether PDGF-BB signaling via PDGFRβ, which is critical for the recruitment of pericytes to blood vessels, plays a role in airway remodeling in chronic asthma. In the present study, we used a selective PDGFRβ inhibitor (CP-673451) to investigate the role of PDGFRβ signaling in the development of airway remodeling and lung dysfunction in an established mouse model of house dust mite-induced chronic allergic asthma. Unexpectedly, we found that pharmacological inhibition of PDGFRβ signaling in the context of chronic aeroallergen exposure led to exacerbated lung dysfunction and airway smooth muscle thickening. Further studies revealed that the inflammatory response to aeroallergen challenge in mice was associated with decreased PDGF-BB expression and the loss of pericytes from the airway microvasculature. In parallel, cells positive for pericyte markers accumulated in the subepithelial region of chronically inflamed airways. This process was exacerbated in animals treated with CP-673451. The results indicate that perturbed PDGF-BB/PDGFRβ signaling and pericyte accumulation in the airway wall may contribute to airway remodeling in chronic allergic asthma. PMID:25637607

  13. A reliable method for intracranial electrode implantation and chronic electrical stimulation in the mouse brain

    PubMed Central

    2013-01-01

    Background Electrical stimulation of brain structures has been widely used in rodent models for kindling or modeling deep brain stimulation used clinically. This requires surgical implantation of intracranial electrodes and subsequent chronic stimulation in individual animals for several weeks. Anchoring screws and dental acrylic have long been used to secure implanted intracranial electrodes in rats. However, such an approach is limited when carried out in mouse models as the thin mouse skull may not be strong enough to accommodate the anchoring screws. We describe here a screw-free, glue-based method for implanting bipolar stimulating electrodes in the mouse brain and validate this method in a mouse model of hippocampal electrical kindling. Methods Male C57 black mice (initial ages of 6–8 months) were used in the present experiments. Bipolar electrodes were implanted bilaterally in the hippocampal CA3 area for electrical stimulation and electroencephalographic recordings. The electrodes were secured onto the skull via glue and dental acrylic but without anchoring screws. A daily stimulation protocol was used to induce electrographic discharges and motor seizures. The locations of implanted electrodes were verified by hippocampal electrographic activities and later histological assessments. Results Using the glue-based implantation method, we implanted bilateral bipolar electrodes in 25 mice. Electrographic discharges and motor seizures were successfully induced via hippocampal electrical kindling. Importantly, no animal encountered infection in the implanted area or a loss of implanted electrodes after 4–6 months of repetitive stimulation/recording. Conclusion We suggest that the glue-based, screw-free method is reliable for chronic brain stimulation and high-quality electroencephalographic recordings in mice. The technical aspects described this study may help future studies in mouse models. PMID:23914984

  14. Inducing Chronic Excitotoxicity in the Mouse Spinal Cord to Investigate Lower Motor Neuron Degeneration

    PubMed Central

    Blizzard, Catherine A.; Lee, K. M.; Dickson, Tracey C.

    2016-01-01

    We report the methodology for the chronic delivery of an excitotoxin to the mouse spinal cord via surgically implanted osmotic mini-pumps. Previous studies have investigated the effect of chronic application of excitotoxins in the rat, however there has been little translation of this model to the mouse. Using mice that express yellow fluorescent protein (YFP), motor neuron and neuromuscular junction alterations can be investigate following targeted, long-term (28 days) exposure to the α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor excitotoxin, kainic acid. By targeting the L3-4 region of the lumbar spinal cord, with insertion of an intrathecal catheter into the subarachnoid space at L5, chronic application of the kainic acid results in slow excitotoxic death in the anterior ventral horn, with a significant (P < 0.05) reduction in the number of SMI-32 immunopositive neurons present after 28 days infusion. Use of the Thy1-YFP mice provides unrivaled visualization of the neuromuscular junction and enables the resultant distal degeneration in skeletal muscle to be observed. Both neuromuscular junction retraction at the gastrocnemius muscle and axonal fragmentation in the sciatic nerve were observed after chronic infusion of kainic acid for 28 days. Lower motor neuron, and distal neuromuscular junction, degeneration are pathological hallmarks of the devastating neurodegenerative disease Amyotrophic Lateral Sclerosis (ALS). This mouse model will be advantageous for increasing our understanding of how the pathophysiological phenomena associated with this disease can lead to lower motor neuron loss and distal pathology, as well as providing a robust in vivo platform to test therapeutic interventions directed at excitotoxic mechanisms. PMID:26973454

  15. No evidence for chronic demyelination in spared axons following spinal cord injury in a mouse

    PubMed Central

    Lasiene, Jurate; Shupe, Larry; Perlmutter, Steve; Horner, Philip

    2008-01-01

    The pattern of remyelination after traumatic spinal cord injury remains elusive, with animal and human studies reporting partial to complete demyelination followed by incomplete remyelination. In the present study, we found that spared rubrospinal tract (RST) axons of passage traced with actively transported dextrans and examined caudally to the lesion twelve weeks after mouse spinal cord contusion injury were fully remyelinated. Spared axons exhibited a marginally reduced myelin thickness and significantly shorter internodes. Contactin-associated protein (CASPR) and Kv1.2 channels were used to identify internodes and paranodal protein distribution properties were used as an index of myelin integrity. This is the first time the CNS myelin internode length was measured in a mouse. To better understand the significance of shortened internodes and thinner myelin in spared axons, we modeled conduction properties using McIntyre’s et al. model of myelinated axons. Mathematical modeling predicted a 21% decrease in the conduction velocity of remyelinated RST axons due to shortened internodes. To determine whether demyelination could be present on axons exhibiting a pathological transport system we utilized the retroviral reporter system. Virally delivered GFP unveiled a small population of dystrophic RST axons that persist chronically with evident demyelination or abnormal remyelination. Collectively these data show that lasting demyelination in spared axons is rare and that remyelination of axons of passage occurs in the chronically injured mouse spinal cord. PMID:18400887

  16. Anticonvulsant effects of a triheptanoin diet in two mouse chronic seizure models

    PubMed Central

    Willis, Sarah; Stoll, James; Sweetman, Lawrence; Borges, Karin

    2010-01-01

    We hypothesized that in epileptic brains citric acid cycle intermediate levels may be deficient leading to hyperexcitability. Anaplerosis is the metabolic refilling of deficient metabolites. Our goal was to determine the anticonvulsant effects of feeding triheptanoin, the triglyceride of anaplerotic heptanoate. CF1 mice were fed 0-35% calories from triheptanoin. Body weights and dietary intake were similar in mice fed triheptanoin vs. standard diet. Triheptanoin feeding increased blood propionyl-carnitine levels, signifying its metabolism. 35%, but not 20%, triheptanoin delayed development of corneal kindled seizures. After pilocarpine-induced status epilepticus (SE), triheptanoin feeding increased the pentylenetetrazole tonic seizure threshold during the chronically epileptic stage. Mice in the chronically epileptic stage showed various changes in brain metabolite levels, including a reduction in malate. Triheptanoin feeding largely restored a reduction in propionyl-CoA levels and increased methylmalonyl-CoA levels in SE mice. In summary, triheptanoin was anticonvulsant in two chronic mouse models and increased levels of anaplerotic precursor metabolites in epileptic mouse brains. The mechanisms of triheptanoin's effects and its efficacy in humans suffering from epilepsy remain to be determined. PMID:20691264

  17. Anticonvulsant effects of a triheptanoin diet in two mouse chronic seizure models.

    PubMed

    Willis, Sarah; Stoll, James; Sweetman, Lawrence; Borges, Karin

    2010-12-01

    We hypothesized that in epileptic brains citric acid cycle intermediate levels may be deficient leading to hyperexcitability. Anaplerosis is the metabolic refilling of deficient metabolites. Our goal was to determine the anticonvulsant effects of feeding triheptanoin, the triglyceride of anaplerotic heptanoate. CF1 mice were fed 0-35% calories from triheptanoin. Body weights and dietary intake were similar in mice fed triheptanoin vs. standard diet. Triheptanoin feeding increased blood propionyl-carnitine levels, signifying its metabolism. 35%, but not 20%, triheptanoin delayed development of corneal kindled seizures. After pilocarpine-induced status epilepticus (SE), triheptanoin feeding increased the pentylenetetrazole tonic seizure threshold during the chronically epileptic stage. Mice in the chronically epileptic stage showed various changes in brain metabolite levels, including a reduction in malate. Triheptanoin feeding largely restored a reduction in propionyl-CoA levels and increased methylmalonyl-CoA levels in SE mice. In summary, triheptanoin was anticonvulsant in two chronic mouse models and increased levels of anaplerotic precursor metabolites in epileptic mouse brains. The mechanisms of triheptanoin's effects and its efficacy in humans suffering from epilepsy remain to be determined. PMID:20691264

  18. Transposon mutagenesis identifies genes driving hepatocellular carcinoma in a chronic hepatitis B mouse model

    PubMed Central

    Bard-Chapeau, Emilie A.; Nguyen, Anh-Tuan; Rust, Alistair G.; Sayadi, Ahmed; Lee, Philip; Chua, Belinda Q; New, Lee-Sun; de Jong, Johann; Ward, Jerrold M.; Chin, Christopher KY.; Chew, Valerie; Toh, Han Chong; Abastado, Jean-Pierre; Benoukraf, Touati; Soong, Richie; Bard, Frederic A.; Dupuy, Adam J.; Johnson, Randy L.; Radda, George K.; Chan, Eric CY.; Wessels, Lodewyk FA.; Adams, David J.

    2014-01-01

    The most common risk factor for developing hepatocellular carcinoma (HCC) is chronic infection with hepatitis B virus (HBV). To better understand the evolutionary forces driving HCC we performed a near saturating transposon mutagenesis screen in a mouse HBV model of HCC. This screen identified 21 candidate early stage drivers, and a bewildering number (2860) of candidate later stage drivers, that were enriched for genes mutated, deregulated, or that function in signaling pathways important for human HCC, with a striking 1199 genes linked to cellular metabolic processes. Our study provides a comprehensive overview of the genetic landscape of HCC. PMID:24316982

  19. Effects of dietary creatine supplementation for 8 weeks on neuromuscular coordination and learning in male albino mouse following neonatal hypoxic ischemic insult.

    PubMed

    Iqbal, Shahid; Ali, Muhammad; Akbar, Atif; Iqbal, Furhan

    2015-05-01

    Creatine monohydrate (Cr) is a dietary supplement known to improve cognitive functions and has positive therapeutic results under various clinical conditions. The aim of this study was to determine the effect of 2 % Cr supplementation on learning, memory formation, neuromuscular coordination, exploratory and locomotory in male albino mice following hypoxic ischemic insult. At postnatal day, 10 male albino mice pups were subjected to right common carotid artery ligation followed by 8 % hypoxia for 25 min. On postnatal day 20, male mice were separated from the litter and divided into two groups on the basis of special diet supplementation. One group was supplemented with 2 % Cr in diet while the other group was raised on ordinary rodent chow for 8 weeks. Behavioral observations were made during rota rod, open field and Morris water maze test for both treatments. It was observed that supplementation with 2 % Cr for 8 weeks following neonatal brain damage resulted in enhanced muscular strength, neuromuscular coordination and improved body weight. In Morris water maze test, it was observed that Cr supplementation significantly improved mean swimming speed and mice on 2 % Cr diet covered more distance but the spatial memory was not improved significantly following hypoxia ischemia encephalopathy (HIE). Open field parameters and percentage of infarct volume remained unaffected following Cr supplementation. We concluded that 2 % dietary Cr supplementation has a potential to improve the muscle strength and body weight in male albino mice following (HIE) and should be considered for the treatment of neurological ailments. PMID:25511980

  20. A novel mouse model identifies cooperating mutations and therapeutic targets critical for chronic myeloid leukemia progression

    PubMed Central

    Giotopoulos, George; van der Weyden, Louise; Osaki, Hikari; Rust, Alistair G.; Gallipoli, Paolo; Meduri, Eshwar; Horton, Sarah J.; Chan, Wai-In; Foster, Donna; Prinjha, Rab K.; Pimanda, John E.; Tenen, Daniel G.; Vassiliou, George S.; Koschmieder, Steffen; Adams, David J.

    2015-01-01

    The introduction of highly selective ABL-tyrosine kinase inhibitors (TKIs) has revolutionized therapy for chronic myeloid leukemia (CML). However, TKIs are only efficacious in the chronic phase of the disease and effective therapies for TKI-refractory CML, or after progression to blast crisis (BC), are lacking. Whereas the chronic phase of CML is dependent on BCR-ABL, additional mutations are required for progression to BC. However, the identity of these mutations and the pathways they affect are poorly understood, hampering our ability to identify therapeutic targets and improve outcomes. Here, we describe a novel mouse model that allows identification of mechanisms of BC progression in an unbiased and tractable manner, using transposon-based insertional mutagenesis on the background of chronic phase CML. Our BC model is the first to faithfully recapitulate the phenotype, cellular and molecular biology of human CML progression. We report a heterogeneous and unique pattern of insertions identifying known and novel candidate genes and demonstrate that these pathways drive disease progression and provide potential targets for novel therapeutic strategies. Our model greatly informs the biology of CML progression and provides a potent resource for the development of candidate therapies to improve the dismal outcomes in this highly aggressive disease. PMID:26304963

  1. Otitis media in the Tgif knockout mouse implicates TGFβ signalling in chronic middle ear inflammatory disease

    PubMed Central

    Tateossian, Hilda; Morse, Susan; Parker, Andrew; Mburu, Philomena; Warr, Nick; Acevedo-Arozena, Abraham; Cheeseman, Michael; Wells, Sara; Brown, Steve D.M.

    2013-01-01

    Otitis media with effusion (OME) is the most common cause of hearing loss in children and tympanostomy to alleviate the condition remains the commonest surgical intervention in children in the developed world. Chronic and recurrent forms of OM are known to have a very significant genetic component, however, until recently little was known of the underlying genes involved. The identification of mouse models of chronic OM has indicated a role of transforming growth factor beta (TGFβ) signalling and its impact on responses to hypoxia in the inflamed middle ear. We have, therefore, investigated the role of TGFβ signalling and identified and characterized a new model of chronic OM carrying a mutation in the gene for transforming growth interacting factor 1 (Tgif1). Tgif1 homozygous mutant mice have significantly raised auditory thresholds due to a conductive deafness arising from a chronic effusion starting at around 3 weeks of age. The OM is accompanied by a significant thickening of the middle ear mucosa lining, expansion of mucin-secreting goblet cell populations and raised levels of vascular endothelial growth factor, TNF-α and IL-1β in ear fluids. We also identified downstream effects on TGFβ signalling in middle ear epithelia at the time of development of chronic OM. Both phosphorylated SMAD2 and p21 levels were lowered in the homozygous mutant, demonstrating a suppression of the TGFβ pathway. The identification and characterization of the Tgif mutant supports the role of TGFβ signalling in the development of chronic OM and provides an important candidate gene for genetic studies in the human population. PMID:23459932

  2. Behavioural signs of chronic back pain in the SPARC-null mouse

    PubMed Central

    Millecamps, Magali; Tajerian, Maral; Sage, E. Helene; Stone, Laura S

    2010-01-01

    Study Design SPARC-null mice were examined for behavioural signs of chronic low back and/or radicular pain. Objective To assess SPARC-null mice as a rodent model of chronic low back and/or radicular pain due to degenerative disc disease. Summary of Background Data Degeneration of intervertebral discs is a major cause of chronic low back and radicular pain in humans. Inactivation of the SPARC (Secreted Protein, Acidic and Rich in Cysteine, also known as osteonectin and BM-40) gene in mice results in premature intervertebral disc degeneration. The impact of disc degeneration on behavioural measures of chronic pain has not been evaluated in this model. Methods Cohorts of young and old (3 and 6–12 months, respectively) SPARC-null and wild-type control mice were screened for behavioural indices of low back and/or radiating pain. Sensitivity to mechanical, cold and heat stimuli, locomotor impairment, and movement-evoked hypersensitivity were determined. Animals were challenged with three analgesic agents with different mechanisms: morphine, dexamethasone, and gabapentin. Results SPARC-null mice showed signs of movement-evoked discomfort as early as 3 months of age. Hypersensitivity to cold stimuli on both the lower back and hindpaws developed with increasing age. SPARC-null mice had normal sensitivity to tactile and heat stimuli, and locomotor skills were not impaired. The hypersensitivity to cold was reversed by morphine, but not by dexamethasone or gabapentin. Conclusion SPARC-null mice display behavioural signs consistent with chronic low back and radicular pain that we attribute to intervertebral disc degeneration. We predict that the SPARC-null mouse is a useful model of chronic back pain due to degenerative disc disease. PMID:20714283

  3. Impact of an additional chronic BDNF reduction on learning performance in an Alzheimer mouse model

    PubMed Central

    Psotta, Laura; Rockahr, Carolin; Gruss, Michael; Kirches, Elmar; Braun, Katharina; Lessmann, Volkmar; Bock, Jörg; Endres, Thomas

    2015-01-01

    There is increasing evidence that brain-derived neurotrophic factor (BDNF) plays a crucial role in Alzheimer’s disease (AD) pathology. A number of studies demonstrated that AD patients exhibit reduced BDNF levels in the brain and the blood serum, and in addition, several animal-based studies indicated a potential protective effect of BDNF against Aβ-induced neurotoxicity. In order to further investigate the role of BDNF in the etiology of AD, we created a novel mouse model by crossing a well-established AD mouse model (APP/PS1) with a mouse exhibiting a chronic BDNF deficiency (BDNF+/−). This new triple transgenic mouse model enabled us to further analyze the role of BDNF in AD in vivo. We reasoned that in case BDNF has a protective effect against AD pathology, an AD-like phenotype in our new mouse model should occur earlier and/or in more severity than in the APP/PS1-mice. Indeed, the behavioral analysis revealed that the APP/PS1-BDNF+/−-mice show an earlier onset of learning impairments in a two-way active avoidance task in comparison to APP/PS1- and BDNF+/−-mice. However in the Morris water maze (MWM) test, we could not observe an overall aggrevated impairment in spatial learning and also short-term memory in an object recognition task remained intact in all tested mouse lines. In addition to the behavioral experiments, we analyzed the amyloid plaque pathology in the APP/PS1 and APP/PS1-BDNF+/−-mice and observed a comparable plaque density in the two genotypes. Moreover, our results revealed a higher plaque density in prefrontal cortical compared to hippocampal brain regions. Our data reveal that higher cognitive tasks requiring the recruitment of cortical networks appear to be more severely affected in our new mouse model than learning tasks requiring mainly sub-cortical networks. Furthermore, our observations of an accelerated impairment in active avoidance learning in APP/PS1-BDNF+/−-mice further supports the hypothesis that BDNF deficiency

  4. Renal Impairment with Sublethal Tubular Cell Injury in a Chronic Liver Disease Mouse Model

    PubMed Central

    Ishida, Tokiko; Kotani, Hirokazu; Miyao, Masashi; Kawai, Chihiro; Jemail, Leila; Abiru, Hitoshi; Tamaki, Keiji

    2016-01-01

    The pathogenesis of renal impairment in chronic liver diseases (CLDs) has been primarily studied in the advanced stages of hepatic injury. Meanwhile, the pathology of renal impairment in the early phase of CLDs is poorly understood, and animal models to elucidate its mechanisms are needed. Thus, we investigated whether an existing mouse model of CLD induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) shows renal impairment in the early phase. Renal injury markers, renal histology (including immunohistochemistry for tubular injury markers and transmission electron microscopy), autophagy, and oxidative stress were studied longitudinally in DDC- and standard diet–fed BALB/c mice. Slight but significant renal dysfunction was evident in DDC-fed mice from the early phase. Meanwhile, histological examinations of the kidneys with routine light microscopy did not show definitive morphological findings, and electron microscopic analyses were required to detect limited injuries such as loss of brush border microvilli and mitochondrial deformities. Limited injuries have been recently designated as sublethal tubular cell injury. As humans with renal impairment, either with or without CLD, often show almost normal tubules, sublethal injury has been of particular interest. In this study, the injuries were associated with mitochondrial aberrations and oxidative stress, a possible mechanism for sublethal injury. Intriguingly, two defense mechanisms were associated with this injury that prevent it from progressing to apparent cell death: autophagy and single-cell extrusion with regeneration. Furthermore, the renal impairment of this model progressed to chronic kidney disease with interstitial fibrosis after long-term DDC feeding. These findings indicated that DDC induces renal impairment with sublethal tubular cell injury from the early phase, leading to chronic kidney disease. Importantly, this CLD mouse model could be useful for studying the pathophysiological mechanisms

  5. The Ketogenic Diet Alters the Hypoxic Response and Affects Expression of Proteins Associated with Angiogenesis, Invasive Potential and Vascular Permeability in a Mouse Glioma Model

    PubMed Central

    Woolf, Eric C.; Curley, Kara L.; Liu, Qingwei; Turner, Gregory H.; Charlton, Julie A.; Preul, Mark C.; Scheck, Adrienne C.

    2015-01-01

    Background The successful treatment of malignant gliomas remains a challenge despite the current standard of care, which consists of surgery, radiation and temozolomide. Advances in the survival of brain cancer patients require the design of new therapeutic approaches that take advantage of common phenotypes such as the altered metabolism found in cancer cells. It has therefore been postulated that the high-fat, low-carbohydrate, adequate protein ketogenic diet (KD) may be useful in the treatment of brain tumors. We have demonstrated that the KD enhances survival and potentiates standard therapy in a mouse model of malignant glioma, yet the mechanisms are not fully understood. Methods To explore the effects of the KD on various aspects of tumor growth and progression, we used the immunocompetent, syngeneic GL261-Luc2 mouse model of malignant glioma. Results Tumors from animals maintained on KD showed reduced expression of the hypoxia marker carbonic anhydrase 9, hypoxia inducible factor 1-alpha, and decreased activation of nuclear factor kappa B. Additionally, tumors from animals maintained on KD had reduced tumor microvasculature and decreased expression of vascular endothelial growth factor receptor 2, matrix metalloproteinase-2 and vimentin. Peritumoral edema was significantly reduced in animals fed the KD and protein analyses showed altered expression of zona occludens-1 and aquaporin-4. Conclusions The KD directly or indirectly alters the expression of several proteins involved in malignant progression and may be a useful tool for the treatment of gliomas. PMID:26083629

  6. Limited Effect of Chronic Valproic Acid Treatment in a Mouse Model of Machado-Joseph Disease

    PubMed Central

    Esteves, Sofia; Duarte-Silva, Sara; Naia, Luana; Neves-Carvalho, Andreia; Teixeira-Castro, Andreia; Rego, Ana Cristina; Silva-Fernandes, Anabela; Maciel, Patrícia

    2015-01-01

    Machado-Joseph disease (MJD) is an inherited neurodegenerative disease, caused by a CAG repeat expansion within the coding region of ATXN3 gene, and which currently lacks effective treatment. In this work we tested the therapeutic efficacy of chronic treatment with valproic acid (VPA) (200mg/kg), a compound with known neuroprotection activity, and previously shown to be effective in cell, fly and nematode models of MJD. We show that chronic VPA treatment in the CMVMJD135 mouse model had limited effects in the motor deficits of these mice, seen mostly at late stages in the motor swimming, beam walk, rotarod and spontaneous locomotor activity tests, and did not modify the ATXN3 inclusion load and astrogliosis in affected brain regions. However, VPA chronic treatment was able to increase GRP78 protein levels at 30 weeks of age, one of its known neuroprotective effects, confirming target engagement. In spite of limited results, the use of another dosage of VPA or of VPA in a combined therapy with molecules targeting other pathways, cannot be excluded as potential strategies for MJD therapeutics. PMID:26505994

  7. Macrophage Depletion Attenuates Extracellular Matrix Deposition and Ductular Reaction in a Mouse Model of Chronic Cholangiopathies.

    PubMed

    Best, Jan; Verhulst, Stefaan; Syn, Wing-Kin; Lagaisse, Kimberly; van Hul, Noemi; Heindryckx, Femke; Sowa, Jan-Peter; Peeters, Liesbeth; Van Vlierberghe, Hans; Leclercq, Isabelle A; Canbay, Ali; Dollé, Laurent; van Grunsven, Leo A

    2016-01-01

    Chronic cholangiopathies, such as primary and secondary sclerosing cholangitis, are progressive disease entities, associated with periportal accumulation of inflammatory cells, encompassing monocytes and macrophages, peribiliary extracellular matrix (ECM) deposition and ductular reaction (DR). This study aimed to elucidate the relevance of macrophages in the progression of chronic cholangiopathies through macrophage depletion in a 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) mouse model. One group of mice received a single i.p. injection of Clodronate encapsulated liposomes (CLOLipo) at day 7 of a 14 day DDC treatment, while control animals were co-treated with PBSLipo instead. Mice were sacrificed after 7 or respectively 14 days of treatment for immunohistochemical assessment of macrophage recruitment (F4/80), ECM deposition (Sirius Red, Laminin) and DR (CK19). Macrophage depletion during a 14 day DDC treatment resulted in a significant inhibition of ECM deposition. Porto-lobular migration patterns of laminin-rich ECM and ductular structures were significantly attenuated and a progression of DR was effectively inhibited by macrophage depletion. CLOLipo co-treatment resulted in a confined DR to portal regions without amorphous cell clusters. This study suggests that therapeutic options selectively directed towards macrophages might represent a feasible treatment for chronic cholestatic liver diseases. PMID:27618307

  8. An optimised mouse model of chronic pancreatitis with a combination of ethanol and cerulein

    PubMed Central

    Ahmadi, Abbas; Nikkhoo, Bahram; Mokarizadeh, Aram; Rahmani, Mohammad-Reza; Fakhari, Shohreh; Mohammadi, Mehdi

    2016-01-01

    Introduction Chronic pancreatitis (CP) is an intractable and multi-factorial disorder. Developing appropriate animal models is an essential step in pancreatitis research, and the best ones are those which mimic the human disorder both aetiologically and pathophysiologically. The current study presents an optimised protocol for creating a murine model of CP, which mimics the initial steps of chronic pancreatitis in alcohol chronic pancreatitis and compares it with two other mouse models treated with cerulein or ethanol alone. Material and methods Thirty-two male C57BL/6 mice were randomly selected, divided into four groups, and treated intraperitoneally with saline (10 ml/kg, control group), ethanol (3 g/kg; 30% v/v), cerulein (50 µg/kg), or ethanol + cerulein, for six weeks. Histopathological and immunohistochemical assays for chronic pancreatitis index along with real-time PCR assessments for mRNA levels of inflammatory cytokines and fibrogenic markers were conducted to verify the CP induction. Results The results indicated that CP index (CPI) was significantly increased in ethanol-cerulein mice compared to the saline, ethanol, and cerulein groups (p < 0.001). Interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), transforming growth factor β (TGF-β), α-smooth muscle actin (α-SMA), and myeloperoxidase activity were also significantly greater in both cerulein and ethanol-cerulein groups than in the saline treated animals (p < 0.001). Immunohistochemical analysis revealed enhanced expression of TGF-β and α-SMA in ethanol-cerulein mice compared to the saline group. Conclusions Intraperitoneal (IP) injections of ethanol and cerulein could successfully induce CP in mice. IP injections of ethanol provide higher reproducibility compared to ethanol feeding. The model is simple, non-invasive, reproducible, and time-saving. Since the protocol mimics the initial phases of CP development in alcoholics, it can be used for investigating basic mechanisms and testing

  9. Chronic traumatic encephalopathy in blast-exposed military veterans and a blast neurotrauma mouse model.

    PubMed

    Goldstein, Lee E; Fisher, Andrew M; Tagge, Chad A; Zhang, Xiao-Lei; Velisek, Libor; Sullivan, John A; Upreti, Chirag; Kracht, Jonathan M; Ericsson, Maria; Wojnarowicz, Mark W; Goletiani, Cezar J; Maglakelidze, Giorgi M; Casey, Noel; Moncaster, Juliet A; Minaeva, Olga; Moir, Robert D; Nowinski, Christopher J; Stern, Robert A; Cantu, Robert C; Geiling, James; Blusztajn, Jan K; Wolozin, Benjamin L; Ikezu, Tsuneya; Stein, Thor D; Budson, Andrew E; Kowall, Neil W; Chargin, David; Sharon, Andre; Saman, Sudad; Hall, Garth F; Moss, William C; Cleveland, Robin O; Tanzi, Rudolph E; Stanton, Patric K; McKee, Ann C

    2012-05-16

    Blast exposure is associated with traumatic brain injury (TBI), neuropsychiatric symptoms, and long-term cognitive disability. We examined a case series of postmortem brains from U.S. military veterans exposed to blast and/or concussive injury. We found evidence of chronic traumatic encephalopathy (CTE), a tau protein-linked neurodegenerative disease, that was similar to the CTE neuropathology observed in young amateur American football players and a professional wrestler with histories of concussive injuries. We developed a blast neurotrauma mouse model that recapitulated CTE-linked neuropathology in wild-type C57BL/6 mice 2 weeks after exposure to a single blast. Blast-exposed mice demonstrated phosphorylated tauopathy, myelinated axonopathy, microvasculopathy, chronic neuroinflammation, and neurodegeneration in the absence of macroscopic tissue damage or hemorrhage. Blast exposure induced persistent hippocampal-dependent learning and memory deficits that persisted for at least 1 month and correlated with impaired axonal conduction and defective activity-dependent long-term potentiation of synaptic transmission. Intracerebral pressure recordings demonstrated that shock waves traversed the mouse brain with minimal change and without thoracic contributions. Kinematic analysis revealed blast-induced head oscillation at accelerations sufficient to cause brain injury. Head immobilization during blast exposure prevented blast-induced learning and memory deficits. The contribution of blast wind to injurious head acceleration may be a primary injury mechanism leading to blast-related TBI and CTE. These results identify common pathogenic determinants leading to CTE in blast-exposed military veterans and head-injured athletes and additionally provide mechanistic evidence linking blast exposure to persistent impairments in neurophysiological function, learning, and memory. PMID:22593173

  10. Effects of chronic ethanol consumption on sterol transfer proteins in mouse brain.

    PubMed

    Myers-Payne, S C; Fontaine, R N; Loeffler, A; Pu, L; Rao, A M; Kier, A B; Wood, W G; Schroeder, F

    1996-01-01

    Although lipids are essential to brain function, almost nothing is known of lipid transfer proteins in the brain. Early reports indicates cross-reactivity of brain proteins with antisera against two native liver sterol transfer proteins, sterol carrier protein-2 (SCP-2) and the liver form of fatty acid-binding protein (L-FABP). Herein, polyclonal antibodies raised against the recombinant liver sterol transfer proteins SCP-2 and L-FABP were used to identify the lipid transfer proteins in the brains of alcohol-treated and control mice. L-FABP was not detectable in brain of either control or chronic ethanol-treated mice. In contrast, SCP-2 not only was present, but its level was significantly (p < 0.05) increased 23 and 50%, respectively, in brain homogenates and synaptosomes of mice exposed to alcohol. To determine whether antibodies against the recombinant liver SCP-2 reflected true levels of SCP-2 in brain, the cDNA sequence for brain SCP-2 was isolated from a brain cDNA library. The mouse brain SCP-2 sequence was 99.99% identical to the mouse liver SCP-2 sequence. The translated sequence differed by only one amino acid, and the replacement was conservative. Thus, unlike the fatty acid binding proteins, the SCP-2 moieties of brain and liver are essentially identical. Polyclonal antibodies against acyl-CoA binding protein, a lipid-binding protein that does not bind or transfer sterol, showed that increased levels of brain SCP-2 with chronic ethanol consumption did not represent a general increase in content of all lipid transfer proteins. Changes in the amount of SCP-2 may contribute to membrane tolerance to ethanol. PMID:8522969

  11. Chronic ultraviolet exposure-induced p53 gene alterations in sencar mouse skin carcinogenesis model

    SciTech Connect

    Tong, Ying; Smith, M.A.; Tucker, S.B.

    1997-06-27

    Alterations of the tumor suppressor gene p53 have been found in ultraviolet radiation (UVR) related human skin cancers and in UVR-induced murine skin tumors. However, links between p53 gene alterations and the stages of carcinogenesis induced by UVR have not been clearly defined. We established a chronic UVR exposure-induced Sencar mouse skin carcinogenesis model to determine the frequency of p53 gene alterations in different stages of carcinogenesis, including UV-exposed skin, papillomas, squamous-cell carcinomas (SCCs), and malignant spindle-cell tumors (SCTs). A high incidence of SCCs and SCTs were found in this model. Positive p53 nuclear staining was found in 10137 (27%) of SCCs and 12124 (50%) of SCTs, but was not detected in normal skin or papillomas. DNA was isolated from 40 paraffin-embedded normal skin, UV-exposed skin, and tumor sections. The p53 gene (exons 5 and 6) was amplified from the sections by using nested polymerase chain reaction (PCR). Subsequent single-strand conformation polymorphism (SSCP) assay and sequencing analysis revealed one point mutation in exon 6 (coden 193, C {r_arrow} A transition) from a UV-exposed skin sample, and seven point mutations in exon 5 (codens 146, 158, 150, 165, and 161, three C {r_arrow} T, two C {r_arrow} A, one C {r_arrow} G, and one A {r_arrow} T transition, respectively) from four SCTs, two SCCs and one UV-exposed skin sample. These experimental results demonstrate that alterations in the p53 gene are frequent events in chronic UV exposure-induced SCCs and later stage SCTs in Sencar mouse skin. 40 refs., 5 figs., 1 tab.

  12. Chronic Traumatic Encephalopathy in Blast-Exposed Military Veterans and a Blast Neurotrauma Mouse Model

    PubMed Central

    Goldstein, Lee E.; Fisher, Andrew M.; Tagge, Chad A.; Zhang, Xiao-Lei; Velisek, Libor; Sullivan, John A.; Upreti, Chirag; Kracht, Jonathan M.; Ericsson, Maria; Wojnarowicz, Mark W.; Goletiani, Cezar J.; Maglakelidze, Giorgi M.; Casey, Noel; Moncaster, Juliet A.; Minaeva, Olga; Moir, Robert D.; Nowinski, Christopher J.; Stern, Robert A.; Cantu, Robert C.; Geiling, James; Blusztajn, Jan K.; Wolozin, Benjamin L.; Ikezu, Tsuneya; Stein, Thor D.; Budson, Andrew E.; Kowall, Neil W.; Chargin, David; Sharon, Andre; Saman, Sudad; Hall, Garth F.; Moss, William C.; Cleveland, Robin O.; Tanzi, Rudolph E.; Stanton, Patric K.; McKee, Ann C.

    2013-01-01

    Blast exposure is associated with traumatic brain injury (TBI), neuropsychiatric symptoms, and long-term cognitive disability. We examined a case series of postmortem brains from U.S. military veterans exposed to blast and/or concussive injury. We found evidence of chronic traumatic encephalopathy (CTE), a tau protein–linked neurodegenerative disease, that was similar to the CTE neuropathology observed in young amateur American football players and a professional wrestler with histories of concussive injuries. We developed a blast neurotrauma mouse model that recapitulated CTE-linked neuropathology in wild-type C57BL/6 mice 2 weeks after exposure to a single blast. Blast-exposed mice demonstrated phosphorylated tauopathy, myelinated axonopathy, microvasculopathy, chronic neuroinflammation, and neurodegeneration in the absence of macroscopic tissue damage or hemorrhage. Blast exposure induced persistent hippocampal-dependent learning and memory deficits that persisted for at least 1 month and correlated with impaired axonal conduction and defective activity-dependent long-term potentiation of synaptic transmission. Intracerebral pressure recordings demonstrated that shock waves traversed the mouse brain with minimal change and without thoracic contributions. Kinematic analysis revealed blast-induced head oscillation at accelerations sufficient to cause brain injury. Head immobilization during blast exposure prevented blast-induced learning and memory deficits. The contribution of blast wind to injurious head acceleration may be a primary injury mechanism leading to blast-related TBI and CTE. These results identify common pathogenic determinants leading to CTE in blast-exposed military veterans and head-injured athletes and additionally provide mechanistic evidence linking blast exposure to persistent impairments in neurophysiological function, learning, and memory. PMID:22593173

  13. Chronic Cellular Imaging of Mouse Visual Cortex During Operant Behavior and Passive Viewing

    PubMed Central

    Andermann, Mark L.; Kerlin, A. M.; Reid, R. C.

    2010-01-01

    Nearby neurons in mammalian neocortex demonstrate a great diversity of cell types and connectivity patterns. The importance of this diversity for computation is not understood. While extracellular recording studies in visual cortex have provided a particularly rich description of behavioral modulation of neural activity, new methods are needed to dissect the contribution of specific circuit elements in guiding visual perception. Here, we describe a method for three-dimensional cellular imaging of neural activity in the awake mouse visual cortex during active discrimination and passive viewing of visual stimuli. Head-fixed mice demonstrated robust discrimination for many hundred trials per day after initial task acquisition. To record from multiple neurons during operant behavior with single-trial resolution and minimal artifacts, we built a sensitive microscope for two-photon calcium imaging, capable of rapid tracking of neurons in three dimensions. We demonstrate stable recordings of cellular calcium activity during discrimination behavior across hours, days, and weeks, using both synthetic and genetically encoded calcium indicators. When combined with molecular and genetic technologies in mice (e.g., cell-type specific transgenic labeling), this approach allows the identification of neuronal classes in vivo. Physiological measurements from distinct classes of neighboring neurons will enrich our understanding of the coordinated roles of diverse elements of cortical microcircuits in guiding sensory perception and perceptual learning. Further, our method provides a high-throughput, chronic in vivo assay of behavioral influences on cellular activity that is applicable to a wide range of mouse models of neurologic disease. PMID:20407583

  14. Chronic Hypertension Leads to Neurodegeneration in the TgSwDI Mouse Model of Alzheimer's Disease.

    PubMed

    Kruyer, Anna; Soplop, Nadine; Strickland, Sidney; Norris, Erin H

    2015-07-01

    Numerous epidemiological studies link vascular disorders, such as hypertension, diabetes mellitus, and stroke, with Alzheimer's disease (AD). Hypertension, specifically, is an important modifiable risk factor for late-onset AD. To examine the link between midlife hypertension and the onset of AD later in life, we chemically induced chronic hypertension in the TgSwDI mouse model of AD in early adulthood. Hypertension accelerated cognitive deficits in the Barnes maze test (P<0.05 after 3 months of treatment; P<0.001 after 6 months), microvascular deposition of β-amyloid (P<0.001 after 3 months of treatment; P<0.05 after 6 months), vascular inflammation (P<0.05 in the dentate gyrus and P<0.001 in the dorsal subiculum after 6 months of treatment), blood-brain barrier leakage (P<0.05 after 3 and 6 months of treatment), and pericyte loss (P<0.05 in the dentate gyrus and P<0.01 in the dorsal subiculum after 6 months of treatment) in these mice. In addition, hypertension induced hippocampal neurodegeneration at an early age in this mouse line (43% reduction in the dorsal subiculum; P<0.05), establishing this as a useful research model of AD with mixed vascular and amyloid pathologies. PMID:25941345

  15. New Mouse Models to Investigate the Efficacy of Drug Combinations in Human Chronic Myeloid Leukemia.

    PubMed

    Lin, Hanyang; Woolfson, Adrian; Jiang, Xiaoyan

    2016-01-01

    Chronic myeloid leukemia (CML) comprises a simple and effective paradigm for generating new insights into the cellular origin, pathogenesis, and treatment of many types of human cancer. In particular, mouse models of CML have greatly facilitated the understanding of the underlying molecular mechanisms and pathogenesis of this disease and have led to the identification of new drug targets that in some cases offer the possibility of functional cure. There are currently three established CML mouse models: the BCR-ABL transgenic model, the BCR-ABL retroviral transduction/transplantation model, and the xenotransplant immunodeficient model. Each has its own unique advantages and disadvantages. Depending on the question of interest, some models may be more appropriate than others. In this chapter, we describe a newly developed xenotransplant mouse model to determine the efficacy of novel therapeutic agents, either alone or in combination. The model facilitates the evaluation of the frequency of leukemic stem cells with long-term leukemia-initiating activity, a critical subcellular population that causes disease relapse and progression, through the utilization of primary CD34(+) CML stem/progenitor cells obtained from CML patients at diagnosis and prior to drug treatment. We have also investigated the effectiveness of new combination treatment strategies designed to prevent the development of leukemia in vivo using BCR-ABL (+) blast crisis cells as a model system. These types of in vivo studies are important for the prediction of individual patient responses to drug therapy, and have the potential to facilitate the design of personalized combination therapy strategies. PMID:27581149

  16. Hormetic Effect of Chronic Hypergravity in a Mouse Model of Allergic Asthma and Rhinitis

    NASA Astrophysics Data System (ADS)

    Jang, Tae Young; Jung, Ah-Yeoun; Kim, Young Hyo

    2016-06-01

    We aimed to evaluate the effect of chronic hypergravity in a mouse model of allergic asthma and rhinitis. Forty BALB/c mice were divided as: group A (n = 10, control) sensitized and challenged with saline, group B (n = 10, asthma) challenged by intraperitoneal and intranasal ovalbumin (OVA) to induce allergic asthma and rhinitis, and groups C (n = 10, asthma/rotatory control) and D (n = 10, asthma/hypergravity) exposed to 4 weeks of rotation with normogravity (1G) or hypergravity (5G) during induction of asthma/rhinitis. Group D showed significantly decreased eosinophils, neutrophils, and lymphocytes in their BAL fluid compared with groups B and C (p < 0.05). In real-time polymerase chain reaction using lung homogenate, the expression of IL-1β was significantly upregulated (p < 0.001) and IL-4 and IL-10 significantly downregulated (p < 0.05) in group D. Infiltration of inflammatory cells into lung parenchyma and turbinate, and the thickness of respiratory epithelium was significantly reduced in group D (p < 0.05). The expression of Bcl-2 and heme oxygenase-1 were significantly downregulated, Bax and extracellular dismutase significantly upregulated in Group D. Therefore, chronic hypergravity could have a hormetic effect for allergic asthma and rhinitis via regulation of genes involved in antioxidative and proapoptotic pathways. It is possible that we could use hypergravity machinery for treating allergic respiratory disorders.

  17. Prostatic inflammation induces fibrosis in a mouse model of chronic bacterial infection.

    PubMed

    Wong, Letitia; Hutson, Paul R; Bushman, Wade

    2014-01-01

    Inflammation of the prostate is strongly correlated with development of lower urinary tract symptoms and several studies have implicated prostatic fibrosis in the pathogenesis of bladder outlet obstruction. It has been postulated that inflammation induces prostatic fibrosis but this relationship has never been tested. Here, we characterized the fibrotic response to inflammation in a mouse model of chronic bacterial-induced prostatic inflammation. Transurethral instillation of the uropathogenic E. coli into C3H/HeOuJ male mice induced persistent prostatic inflammation followed by a significant increase in collagen deposition and hydroxyproline content. This fibrotic response to inflammation was accompanied with an increase in collagen synthesis determined by the incorporation of 3H-hydroxyproline and mRNA expression of several collagen remodeling-associated genes, including Col1a1, Col1a2, Col3a1, Mmp2, Mmp9, and Lox. Correlation analysis revealed a positive correlation of inflammation severity with collagen deposition and immunohistochemical staining revealed that CD45+VIM+ fibrocytes were abundant in inflamed prostates at the time point coinciding with increased collagen synthesis. Furthermore, flow cytometric analysis demonstrated an increased percentage of these CD45+VIM+ fibrocytes among collagen type I expressing cells. These data show-for the first time-that chronic prostatic inflammation induces collagen deposition and implicates fibrocytes in the fibrotic process. PMID:24950301

  18. Selenoether oxytocin analogues have analgesic properties in a mouse model of chronic abdominal pain.

    PubMed

    de Araujo, Aline Dantas; Mobli, Mehdi; Castro, Joel; Harrington, Andrea M; Vetter, Irina; Dekan, Zoltan; Muttenthaler, Markus; Wan, JingJing; Lewis, Richard J; King, Glenn F; Brierley, Stuart M; Alewood, Paul F

    2014-01-01

    Poor oral availability and susceptibility to reduction and protease degradation is a major hurdle in peptide drug development. However, drugable receptors in the gut present an attractive niche for peptide therapeutics. Here we demonstrate, in a mouse model of chronic abdominal pain, that oxytocin receptors are significantly upregulated in nociceptors innervating the colon. Correspondingly, we develop chemical strategies to engineer non-reducible and therefore more stable oxytocin analogues. Chemoselective selenide macrocyclization yields stabilized analogues equipotent to native oxytocin. Ultra-high-field nuclear magnetic resonance structural analysis of native oxytocin and the seleno-oxytocin derivatives reveals that oxytocin has a pre-organized structure in solution, in marked contrast to earlier X-ray crystallography studies. Finally, we show that these seleno-oxytocin analogues potently inhibit colonic nociceptors both in vitro and in vivo in mice with chronic visceral hypersensitivity. Our findings have potentially important implications for clinical use of oxytocin analogues and disulphide-rich peptides in general. PMID:24476666

  19. Hormetic Effect of Chronic Hypergravity in a Mouse Model of Allergic Asthma and Rhinitis

    PubMed Central

    Jang, Tae Young; Jung, Ah-Yeoun; Kim, Young Hyo

    2016-01-01

    We aimed to evaluate the effect of chronic hypergravity in a mouse model of allergic asthma and rhinitis. Forty BALB/c mice were divided as: group A (n = 10, control) sensitized and challenged with saline, group B (n = 10, asthma) challenged by intraperitoneal and intranasal ovalbumin (OVA) to induce allergic asthma and rhinitis, and groups C (n = 10, asthma/rotatory control) and D (n = 10, asthma/hypergravity) exposed to 4 weeks of rotation with normogravity (1G) or hypergravity (5G) during induction of asthma/rhinitis. Group D showed significantly decreased eosinophils, neutrophils, and lymphocytes in their BAL fluid compared with groups B and C (p < 0.05). In real-time polymerase chain reaction using lung homogenate, the expression of IL-1β was significantly upregulated (p < 0.001) and IL-4 and IL-10 significantly downregulated (p < 0.05) in group D. Infiltration of inflammatory cells into lung parenchyma and turbinate, and the thickness of respiratory epithelium was significantly reduced in group D (p < 0.05). The expression of Bcl-2 and heme oxygenase-1 were significantly downregulated, Bax and extracellular dismutase significantly upregulated in Group D. Therefore, chronic hypergravity could have a hormetic effect for allergic asthma and rhinitis via regulation of genes involved in antioxidative and proapoptotic pathways. It is possible that we could use hypergravity machinery for treating allergic respiratory disorders. PMID:27251783

  20. Hormetic Effect of Chronic Hypergravity in a Mouse Model of Allergic Asthma and Rhinitis.

    PubMed

    Jang, Tae Young; Jung, Ah-Yeoun; Kim, Young Hyo

    2016-01-01

    We aimed to evaluate the effect of chronic hypergravity in a mouse model of allergic asthma and rhinitis. Forty BALB/c mice were divided as: group A (n = 10, control) sensitized and challenged with saline, group B (n = 10, asthma) challenged by intraperitoneal and intranasal ovalbumin (OVA) to induce allergic asthma and rhinitis, and groups C (n = 10, asthma/rotatory control) and D (n = 10, asthma/hypergravity) exposed to 4 weeks of rotation with normogravity (1G) or hypergravity (5G) during induction of asthma/rhinitis. Group D showed significantly decreased eosinophils, neutrophils, and lymphocytes in their BAL fluid compared with groups B and C (p < 0.05). In real-time polymerase chain reaction using lung homogenate, the expression of IL-1β was significantly upregulated (p < 0.001) and IL-4 and IL-10 significantly downregulated (p < 0.05) in group D. Infiltration of inflammatory cells into lung parenchyma and turbinate, and the thickness of respiratory epithelium was significantly reduced in group D (p < 0.05). The expression of Bcl-2 and heme oxygenase-1 were significantly downregulated, Bax and extracellular dismutase significantly upregulated in Group D. Therefore, chronic hypergravity could have a hormetic effect for allergic asthma and rhinitis via regulation of genes involved in antioxidative and proapoptotic pathways. It is possible that we could use hypergravity machinery for treating allergic respiratory disorders. PMID:27251783

  1. Effects of Chung-Pae Inhalation Therapy on a Mouse Model of Chronic Obstructive Pulmonary Disease

    PubMed Central

    Hwang, Joon-Ho; Lee, Beom-Joon; Jung, Hee Jae; Kim, Kwan-Il; Choi, Jun-Yong; Joo, Myungsoo; Jung, Sung-Ki

    2015-01-01

    Chung-pae (CP) inhalation therapy is a method frequently used in Korea to treat lung disease, especially chronic obstructive pulmonary disease (COPD). This study investigated the effects of CP inhalation on a COPD animal model. C57BL/6 mice received porcine pancreatic elastase (PPE) and lipopolysaccharide (LPS) alternately three times for 3 weeks to induce COPD. Then, CP (5 or 20 mg/kg) was administered every 2 h after the final LPS administration. The effect of CP was evaluated by bronchoalveolar lavage (BAL) fluid analysis, histological analysis of lung tissue, and reverse transcription polymerase chain reaction analysis of mRNA of interleukin- (IL-) 1β, tumor necrosis factor- (TNF-) α, IL-6, and tumor growth factor- (TGF-) β. Intratracheal CP administration reduced the number of leukocytes and neutrophils in BAL fluid, inhibited the histological appearance of lung damage, and decreased the mRNA levels of the proinflammatory cytokines IL-1β, TNF-α, IL-6, and TGF-β. Intratracheal CP administration effectively decreased the chronic inflammation and pathological changes in a PPE- and LPS-induced COPD mouse model. Therefore, we suggest that CP is a promising strategy for COPD. PMID:26539225

  2. Chronic Exposure to Ambient Levels of Urban Particles Affects Mouse Lung Development

    PubMed Central

    Mauad, Thais; Rivero, Dolores Helena Rodriguez Ferreira; de Oliveira, Regiani Carvalho; de Faria Coimbra Lichtenfels, Ana Julia; Guimarães, Eliane Tigre; de Andre, Paulo Afonso; Kasahara, David Itiro; de Siqueira Bueno, Heloisa Maria; Saldiva, Paulo Hilário Nascimento

    2008-01-01

    Rationale: Chronic exposure to air pollution has been associated with adverse effects on children's lung growth. Objectives: We analyzed the effects of chronic exposure to urban levels of particulate matter (PM) on selected phases of mouse lung development. Methods: The exposure occurred in two open-top chambers (filtered and nonfiltered) placed 20 m from a street with heavy traffic in São Paulo, 24 hours/day for 8 months. There was a significant reduction of the levels of PM2.5 inside the filtered chamber (filtered = 2.9 ± 3.0 μg/m3, nonfiltered = 16.8 ± 8.3 μg/m3; P = 0.001). At this exposure site, vehicular sources are the major components of PM2.5 (PM ≤ 2.5μm). Exposure of the parental generation in the two chambers occurred from the 10th to the 120th days of life. After mating and birth of offspring, a crossover of mothers and pups occurred within the chambers, resulting in four groups of pups: nonexposed, prenatal, postnatal, and pre+postnatal. Offspring were killed at the age of 15 (n = 42) and 90 (n = 35) days; lungs were analyzed by morphometry for surface to volume ratio (as an estimator of alveolization). Pressure–volume curves were performed in the older groups, using a 20-ml plethysmograph. Measurements and Main Results: Mice exposed to PM2.5 pre+postnatally presented a smaller surface to volume ratio when compared with nonexposed animals (P = 0.036). The pre+postnatal group presented reduced inspiratory and expiratory volumes at higher levels of transpulmonary pressure (P = 0.001). There were no differences among prenatal and postnatal exposure and nonexposed animals. Conclusions: Our data provide anatomical and functional support to the concept that chronic exposure to urban PM affects lung growth. PMID:18596224

  3. Hypoxic Conditioning as a New Therapeutic Modality

    PubMed Central

    Verges, Samuel; Chacaroun, Samarmar; Godin-Ribuot, Diane; Baillieul, Sébastien

    2015-01-01

    Preconditioning refers to a procedure by which a single noxious stimulus below the threshold of damage is applied to the tissue in order to increase resistance to the same or even different noxious stimuli given above the threshold of damage. Hypoxic preconditioning relies on complex and active defenses that organisms have developed to counter the adverse consequences of oxygen deprivation. The protection it confers against ischemic attack for instance as well as the underlying biological mechanisms have been extensively investigated in animal models. Based on these data, hypoxic conditioning (consisting in recurrent exposure to hypoxia) has been suggested a potential non-pharmacological therapeutic intervention to enhance some physiological functions in individuals in whom acute or chronic pathological events are anticipated or existing. In addition to healthy subjects, some benefits have been reported in patients with cardiovascular and pulmonary diseases as well as in overweight and obese individuals. Hypoxic conditioning consisting in sessions of intermittent exposure to moderate hypoxia repeated over several weeks may induce hematological, vascular, metabolic, and neurological effects. This review addresses the existing evidence regarding the use of hypoxic conditioning as a potential therapeutic modality, and emphasizes on many remaining issues to clarify and future researches to be performed in the field. PMID:26157787

  4. Adenovirus-mediated HIF-1α gene transfer promotes repair of mouse airway allograft microvasculature and attenuates chronic rejection.

    PubMed

    Jiang, Xinguo; Khan, Mohammad A; Tian, Wen; Beilke, Joshua; Natarajan, Ramesh; Kosek, Jon; Yoder, Mervin C; Semenza, Gregg L; Nicolls, Mark R

    2011-06-01

    Chronic rejection, manifested as small airway fibrosis (obliterative bronchiolitis [OB]), is the main obstacle to long-term survival in lung transplantation. Recent studies demonstrate that the airways involved in a lung transplant are relatively hypoxic at baseline and that OB pathogenesis may be linked to ischemia induced by a transient loss of airway microvasculature. Here, we show that HIF-1α mediates airway microvascular repair in a model of orthotopic tracheal transplantation. Grafts with a conditional knockout of Hif1a demonstrated diminished recruitment of recipient-derived Tie2⁺ angiogenic cells to the allograft, impaired repair of damaged microvasculature, accelerated loss of microvascular perfusion, and hastened denudation of epithelial cells. In contrast, graft HIF-1α overexpression induced via an adenoviral vector prolonged airway microvascular perfusion, preserved epithelial integrity, extended the time window for the graft to be rescued from chronic rejection, and attenuated airway fibrotic remodeling. HIF-1α overexpression induced the expression of proangiogenic factors such as Sdf1, Plgf, and Vegf, and promoted the recruitment of vasoreparative Tie2⁺ cells. This study demonstrates that a therapy that enhances vascular integrity during acute rejection may promote graft health and prevent chronic rejection. PMID:21606594

  5. Effect of Chronic Uremia on the Cell Surface Expression of B7 Family Costimulatory Molecules in an HLA-A2 Transgenic Mouse Model of Chronic Kidney Disease

    PubMed Central

    Makidon, Paul E; Smith, Douglas M; Groom, Jeffery V; Cao, Zhengyi; Landers, Jeffery J; Baker, James R

    2015-01-01

    Uremia due to chronic kidney disease (CKD) in humans is associated with immune dysfunction, increased susceptibility to infections, immune-activation–associated inflammation, and poor responses to vaccines. The pathophysiologic basis of these immune defects is hypothesized to be associated with a wide range of immunologic abnormalities, including an inability to sufficiently express the B7 family (B7-1, CD80; B7-2, CD86) of T-cell costimulatory molecules. However, testing the hypothesis that a state of chronic uremia contributes to attenuated expression of CD80 or CD86 has been difficult because few animal models faithfully recapitulate the immune defects observed in human CKD patients. We used a humanized mouse in a model of surgically induced renal failure and secondary chronic uremia to evaluate the effect of uremia on the expression of these markers. In a manner that resembles the changes observed in CKD patients, surgically induced CKD in mice resulted in decreased costimulatory CD86 expression compared with that in sham-operated controls. Immunodeficiency was functionally demonstrated in this mouse model by documenting an attenuated immune response to a cholera-toxin–based hepatitis B vaccine. This model will be useful for investigating the mechanisms involved in chronic uremia-associated immunodeficiency, poor response to vaccination, and problems associated with immunization of CKD patients. PMID:26310460

  6. Chronic maternal morphine alters calbindin D-28k expression pattern in postnatal mouse brain.

    PubMed

    Mithbaokar, Pratibha; Fiorito, Filomena; Della Morte, Rossella; Maharajan, Veeramani; Costagliola, Anna

    2016-01-01

    The distribution pattern of calbindin (CB)-D28k-expressing neurons results to be altered in several brain regions of chronic morphine exposed adult mice. In this study, the influence of chronic maternal exposure to morphine on the distribution pattern of CB-D28k-expressing neurons in the brain of mouse offspring was investigated. Females of CD-1 mice were daily administered with saline or morphine for 7 days before mating, during the whole gestation period, and until 21 day post-partum. Their offspring were sacrificed on postnatal day 18, and the brains were examined by histology using cresyl violet and by immunohistochemistry using a rabbit polyclonal anti-CB-D28k antibody. Histology revealed no significant differences in the distribution pattern and the number of neurons between the offspring forebrain of the control group of mice and the two groups of mice treated with different doses of morphine. However, immunohistochemical analysis revealed that the number of CB-D28k-immunoreactive neurons remarkably decreased in the cingulate cortex, in the layers II-IV of the parietal cortex and in all regions of the hippocampus, while it increased in the layers V-VI of the parietal cortex and in the subicular region of the offspring brain of morphine treated mice. Overall, our findings demonstrate that maternal exposure to morphine alters the pattern of CB-D28k-expressing neuron pattern in specific regions of murine developing brain, in a layer- and dose-dependent way, thus suggesting that these alterations might represent a mechanism by which morphine modifies the functional aspects of developing brain. PMID:26418221

  7. Immune System Modifications Induced in a Mouse Model of Chronic Exposure to (90)Sr.

    PubMed

    Synhaeve, Nicholas; Musilli, Stefania; Stefani, Johanna; Nicolas, Nour; Delissen, Olivia; Dublineau, Isabelle; Bertho, Jean-Marc

    2016-03-01

    Strontium 90 ((90)Sr) remains in the environment long after a major nuclear disaster occurs. As a result, populations living on contaminated land are potentially exposed to daily ingesting of low quantities of (90)Sr. The potential long-term health effects of such chronic contamination are unknown. In this study, we used a mouse model to evaluate the effects of (90)Sr ingestion on the immune system, the animals were chronically exposed to (90)Sr in drinking water at a concentration of 20 kBq/l, for a daily ingestion of 80-100 Bq/day. This resulted in a reduced number of CD19(+) B lymphocytes in the bone marrow and spleen in steady-state conditions. In contrast, the results from a vaccine experiment performed as a functional test of the immune system showed that in response to T-dependent antigens, there was a reduction in IgG specific to tetanus toxin (TT), a balanced Th1/Th2 response inducer antigen, but not to keyhole limpet hemocyanin (KLH), a strong Th2 response inducer antigen. This was accompanied by a reduction in Th1 cells in the spleen, consistent with the observed reduction in specific IgG concentration. The precise mechanisms by which (90)Sr acts on the immune system remain to be elucidated. However, our results suggest that (90)Sr ingestion may be responsible for some of the reported effects of internal contamination on the immune system in civilian populations exposed to the Chernobyl fallout. PMID:26930377

  8. Chronic lymphocytic leukaemia induces an exhausted T cell phenotype in the TCL1 transgenic mouse model.

    PubMed

    Gassner, Franz J; Zaborsky, Nadja; Catakovic, Kemal; Rebhandl, Stefan; Huemer, Michael; Egle, Alexander; Hartmann, Tanja N; Greil, Richard; Geisberger, Roland

    2015-08-01

    Although chronic lymphocytic leukaemia (CLL) is a B cell malignancy, earlier studies have indicated a role of T cells in tumour growth and disease progression. In particular, the functional silencing of antigen-experienced T cells, called T cell exhaustion, has become implicated in immune evasion in CLL. In this study, we tested whether T cell exhaustion is recapitulated in the TCL1(tg) mouse model for CLL. We show that T cells express high levels of the inhibitory exhaustion markers programmed cell death 1 (PDCD1, also termed PD-1) and lymphocyte-activation gene 3 (LAG3), whereas CLL cells express high levels of CD274 (also termed PD-ligand 1). In addition, the fraction of exhausted T cells increases with CLL progression. Finally, we demonstrate that exhausted T cells are reinvigorated towards CLL cytotoxicity by inhibition of PDCD1/CD274 interaction in vivo. These results suggest that T cell exhaustion contributes to CLL pathogenesis and that interference with PDCD1/CD274 signalling holds high potential for therapeutic approaches. PMID:25940792

  9. Chronic lymphocytic leukaemia induces an exhausted T cell phenotype in the TCL1 transgenic mouse model

    PubMed Central

    Gassner, Franz J; Zaborsky, Nadja; Catakovic, Kemal; Rebhandl, Stefan; Huemer, Michael; Egle, Alexander; Hartmann, Tanja N; Greil, Richard; Geisberger, Roland

    2015-01-01

    Although chronic lymphocytic leukaemia (CLL) is a B cell malignancy, earlier studies have indicated a role of T cells in tumour growth and disease progression. In particular, the functional silencing of antigen-experienced T cells, called T cell exhaustion, has become implicated in immune evasion in CLL. In this study, we tested whether T cell exhaustion is recapitulated in the TCL1tg mouse model for CLL. We show that T cells express high levels of the inhibitory exhaustion markers programmed cell death 1 (PDCD1, also termed PD-1) and lymphocyte-activation gene 3 (LAG3), whereas CLL cells express high levels of CD274 (also termed PD-ligand 1). In addition, the fraction of exhausted T cells increases with CLL progression. Finally, we demonstrate that exhausted T cells are reinvigorated towards CLL cytotoxicity by inhibition of PDCD1/CD274 interaction in vivo. These results suggest that T cell exhaustion contributes to CLL pathogenesis and that interference with PDCD1/CD274 signalling holds high potential for therapeutic approaches. PMID:25940792

  10. Alterations in the distal colon innervation in Winnie mouse model of spontaneous chronic colitis.

    PubMed

    Rahman, Ahmed A; Robinson, Ainsley M; Jovanovska, Valentina; Eri, Rajaraman; Nurgali, Kulmira

    2015-12-01

    The gastrointestinal tract is innervated by extrinsic sympathetic, parasympathetic and sensory nerve fibers as well as by intrinsic fibers from the neurons in myenteric and submucosal ganglia embedded into the gastrointestinal wall. Morphological and functional studies of intestinal innervation in animal models are important for understanding the pathophysiology of inflammatory bowel disease (IBD). The recently established Winnie mouse model of spontaneous chronic colitis caused by a point mutation in the Muc2 mucin gene develops inflammation due to a primary epithelial defect. Winnie mice display symptoms of diarrhea, ulcerations and rectal bleeding similar to those in IBD. In this study, we investigated myenteric neurons, noradrenergic, cholinergic and sensory nerve fibers in the distal colon of Winnie (Win/Win) mice compared to C57/BL6 and heterozygote littermates (Win/Wt) using histological and immunohistochemical methods. All Win/Win mice used in this study had inflammation with signs of mucosal damage, goblet cell loss, thickening of muscle and mucosal layers, and increased CD45-immunoreactivity in the distal colon. The density of sensory, cholinergic and noradrenergic fibers innervating the myenteric plexus, muscle and mucosa significantly decreased in the distal colon of Win/Win mice compared to C57/BL6 and Win/Wt mice, while the total number of myenteric neurons as well as subpopulations of cholinergic and nitrergic neurons remained unchanged. In conclusion, changes in the colon morphology and innervation found in Winnie mice have multiple similarities with changes observed in patients with ulcerative colitis. PMID:26227258

  11. Complement protein C3 exacerbates prion disease in a mouse model of chronic wasting disease.

    PubMed

    Michel, Brady; Ferguson, Adam; Johnson, Theodore; Bender, Heather; Meyerett-Reid, Crystal; Wyckoff, A Christy; Pulford, Bruce; Telling, Glenn C; Zabel, Mark D

    2013-12-01

    Accumulating evidence shows a critical role of the complement system in facilitating attachment of prions to both B cells and follicular dendritic cells and assisting in prion replication. Complement activation intensifies disease in prion-infected animals, and elimination of complement components inhibits prion accumulation, replication and pathogenesis. Chronic wasting disease (CWD) is a highly infectious prion disease of captive and free-ranging cervid populations that utilizes the complement system for efficient peripheral prion replication and most likely efficient horizontal transmission. Here we show that complete genetic or transient pharmacological depletion of C3 prolongs incubation times and significantly delays splenic accumulation in a CWD transgenic mouse model. Using a semi-quantitative prion amplification scoring system we show that C3 impacts disease progression in the early stages of disease by slowing the rate of prion accumulation and/or replication. The delayed kinetics in prion replication correlate with delayed disease kinetics in mice deficient in C3. Taken together, these data support a critical role of C3 in peripheral CWD prion pathogenesis. PMID:24038599

  12. Hepatic transcriptomic and metabolic responses of hybrid striped bass (Morone saxatilis×Morone chrysops) to acute and chronic hypoxic insult.

    PubMed

    Beck, Benjamin H; Fuller, S Adam; Li, Chao; Green, Bartholomew W; Zhao, Honggang; Rawles, Steven D; Webster, Carl D; Peatman, Eric

    2016-06-01

    Striped bass (Morone saxatilis), white bass (Morone chrysops), and their hybrid are an important group of fish prized for recreational angling in the United States, and there and abroad as a high-value farmed fish. Regardless of habitat, it is not uncommon for fish of the genus Morone to encounter and cope with conditions of scarce oxygen availability. Previously, we determined that hybrid striped bass reared under conditions of chronic hypoxia exhibited reduced feed intake, lower lipid and nutrient retention, and poor growth. To better understand the molecular mechanisms governing these phenotypes, in the present study, we examined the transcriptomic profiles of hepatic tissue in hybrid striped bass exposed to chronic hypoxia (90days at 25% oxygen saturation) and acute hypoxia (6h at 25% oxygen saturation). Using high-throughput RNA-seq, we found that over 1400 genes were differentially expressed under disparate oxygen conditions, with the vast majority of transcriptional changes occurring in the acute hypoxia treatment. Gene pathway and bioenergetics analyses revealed hypoxia-mediated perturbation of genes and gene networks related to lipid metabolism, cell death, and changes in hepatic mitochondrial content and cellular respiration. This study offers a more comprehensive view of the temporal and tissue-specific transcriptional changes that occur during hypoxia, and reveals new and shared mechanisms of hypoxia tolerance in teleosts. PMID:26851735

  13. Standardized Profiling of The Membrane-Enriched Proteome of Mouse Dorsal Root Ganglia (DRG) Provides Novel Insights Into Chronic Pain.

    PubMed

    Rouwette, Tom; Sondermann, Julia; Avenali, Luca; Gomez-Varela, David; Schmidt, Manuela

    2016-06-01

    Chronic pain is a complex disease with limited treatment options. Several profiling efforts have been employed with the aim to dissect its molecular underpinnings. However, generated results are often inconsistent and nonoverlapping, which is largely because of inherent technical constraints. Emerging data-independent acquisition (DIA)-mass spectrometry (MS) has the potential to provide unbiased, reproducible and quantitative proteome maps - a prerequisite for standardization among experiments. Here, we designed a DIA-based proteomics workflow to profile changes in the abundance of dorsal root ganglia (DRG) proteins in two mouse models of chronic pain, inflammatory and neuropathic. We generated a DRG-specific spectral library containing 3067 DRG proteins, which enables their standardized quantification by means of DIA-MS in any laboratory. Using this resource, we profiled 2526 DRG proteins in each biological replicate of both chronic pain models and respective controls with unprecedented reproducibility. We detected numerous differentially regulated proteins, the majority of which exhibited pain model-specificity. Our approach recapitulates known biology and discovers dozens of proteins that have not been characterized in the somatosensory system before. Functional validation experiments and analysis of mouse pain behaviors demonstrate that indeed meaningful protein alterations were discovered. These results illustrate how the application of DIA-MS can open new avenues to achieve the long-awaited standardization in the molecular dissection of pathologies of the somatosensory system. Therefore, our findings provide a valuable framework to qualitatively extend our understanding of chronic pain and somatosensation. PMID:27103637

  14. Chronic methamphetamine treatment reduces the expression of synaptic plasticity genes and changes their DNA methylation status in the mouse brain.

    PubMed

    Cheng, Min-Chih; Hsu, Shih-Hsin; Chen, Chia-Hsiang

    2015-12-10

    Methamphetamine (METH) is a highly addictive psychostimulant that may cause long-lasting synaptic dysfunction and abnormal gene expression. We aimed to explore the differential expression of synaptic plasticity genes in chronic METH-treated mouse brain. We used the RT(2) Profiler PCR Array and the real-time quantitative PCR to characterize differentially expressed synaptic plasticity genes in the frontal cortex and the hippocampus of chronic METH-treated mice compared with normal saline-treated mice. We further used pyrosequencing to assess DNA methylation changes in the CpG region of the five immediate early genes (IEGs) in chronic METH-treated mouse brain. We detected six downregulated genes in the frontal cortex and the hippocampus of chronic METH-treated mice, including five IEGs (Arc, Egr2, Fos, Klf10, and Nr4a1) and one neuronal receptor gene (Grm1), compared with normal saline-treated group, but only four genes (Arc, Egr2, Fos, and Nr4a1) were confirmed to be different. Furthermore, we found several CpG sites of the Arc and the Fos that had significant changes in DNA methylation status in the frontal cortex of chronic METH-treated mice, while the klf10 and the Nr4a1 that had significant changes in the hippocampus. Our results show that chronic administration of METH may lead to significant downregulation of the IEGs expression in both the frontal cortex and the hippocampus, which may partly account for the molecular mechanism of the action of METH. Furthermore, the changes in DNA methylation status of the IEGs in the brain indicate that an epigenetic mechanism-dependent transcriptional regulation may contribute to METH addiction, which warrants additional study. PMID:26496011

  15. Neuroprotective Effect of Compound Anisodine in a Mouse Model with Chronic Ocular Hypertension

    PubMed Central

    Liu, Wen-Dong; Chen, Lan-Lan; Shen, Ce-Ying; Jiang, Li-Bin

    2015-01-01

    Background: Compound anisodine (CA) is a compound preparation made from hydrobromide anisodine and procaine hydrochloride. The former is an M-choline receptor blocker with the function of regulating the vegetative nervous system, improving microcirculation, and so on. The latter is an antioxidant with the activities of neuroprotection. This study aimed to investigate the potential neuroprotection of CA, which affects the degeneration of the retinal ganglion cells (RGCs) in an animal model with chronic ocular hypertension. Methods: Female C57BL/6J mice (n = 24) were divided randomly into four groups: Normal control group without any treatment (Group A, n = 6); CA control group with feeding the CA solution (Group B, n = 6); microbeads (MBs) control group with injecting MB into the anterior chamber (Group C, n = 6); CA study group with MB injection and with feeding the CA solution (Group D, n = 6). Intraocular pressure (IOP) was measured every 3 days after MB injection. At the 21st day, neurons were retrograde-labeled by Fluoro-Gold (FG). Animals were sacrificed on the 27th day. Retinal flat mounts were stained immunohistologically by β-III-tubulin. FG-retrograde-labeled RGCs, β-III-tubulin-positive RGCs, and β-III-tubulin-positive nerve fibers were quantified. Results: Mice of Groups C and D expressed the incidence of consistent IOP elevation, which is above the IOP level of Group A with the normal one. There is no significant difference in IOP between Groups A and B (P > 0.05). On the 27th day, there were distinct loss in stained RGCs and nerve fibers from Groups C and D compared with Group A (all P < 0.001). The quantity was significantly higher in Group D as compared to Group C (all P < 0.001) but lower than Group A (all P < 0.001). There was no significant difference in the quantity of RGCs and nerve fibers between Groups A and B (all P > 0.05). Conclusions: These findings suggest that CA plays an importantly neuroprotective role on RGCs in a mouse model with

  16. Manganese Superoxide Dismutase Protects Mouse Cortical Neurons From Chronic Intermittent Hypoxia-Mediated Oxidative Damage

    PubMed Central

    Shan, Xiaoyang; Chi, Liying; Ke, Yan; Luo, Chun; Qian, Steven; Gozal, David; Liu, Rugao

    2007-01-01

    Obstructive Sleep Apnea (OSA) syndrome has been recognized as a highly prevalent public health problem and is associated with major neurobehavioral morbidity. Chronic intermittent hypoxia (CIH), a major pathological component of OSA, increases oxidative damage to the brain cortex and decreases neurocognitive function in rodent models resembling human OSA. We employed in vitro and in vivo approaches to identify the specific phases and subcellular compartments in which enhanced reactive oxygen species (ROS) are generated during CIH. In addition, we utilized the cell culture and animal models to analyze the consequences of enhanced production of ROS on cortical neuronal cell damage and neurocognitive dysfunction. In a primary cortical neuron culture system, we demonstrated that the transition phase from hypoxia to normoxia (NOX) during CIH generates more ROS than the transition phase from NOX to hypoxia or hypoxia alone, all of which generate more ROS than NOX. Using selective inhibitors of the major pathways underlying ROS generation in the cell membrane, cytosol, and mitochondria, we showed that the mitochondria are the predominant source of enhanced ROS generation during CIH in mouse cortical neuronal cells. Furthermore, in both cell culture and transgenic mice, we demonstrated that overexpression of MnSOD decreased CIH-mediated cortical neuronal apoptosis, and reduced spatial learning deficits measured with the Morris water maze assay. Together, the data from the in vitro and in vivo experiments indicate that CIH-mediated mitochondrial oxidative stress may play a major role in the neuronal cell loss and neurocognitive dysfunction in OSA. Thus, therapeutic strategies aiming at reducing ROS generation from mitochondria may improve the neurobehavioral morbidity in OSA. PMID:17719231

  17. Restoration of Oligodendrocyte Pools in a Mouse Model of Chronic Cerebral Hypoperfusion

    PubMed Central

    McQueen, Jamie; Reimer, Michell M.; Holland, Philip R.; Manso, Yasmina; McLaughlin, Mark; Fowler, Jill H.; Horsburgh, Karen

    2014-01-01

    Chronic cerebral hypoperfusion, a sustained modest reduction in cerebral blood flow, is associated with damage to myelinated axons and cognitive decline with ageing. Oligodendrocytes (the myelin producing cells) and their precursor cells (OPCs) may be vulnerable to the effects of hypoperfusion and in some forms of injury OPCs have the potential to respond and repair damage by increased proliferation and differentiation. Using a mouse model of cerebral hypoperfusion we have characterised the acute and long term responses of oligodendrocytes and OPCs to hypoperfusion in the corpus callosum. Following 3 days of hypoperfusion, numbers of OPCs and mature oligodendrocytes were significantly decreased compared to controls. However following 1 month of hypoperfusion, the OPC pool was restored and increased numbers of oligodendrocytes were observed. Assessment of proliferation using PCNA showed no significant differences between groups at either time point but showed reduced numbers of proliferating oligodendroglia at 3 days consistent with the loss of OPCs. Cumulative BrdU labelling experiments revealed higher numbers of proliferating cells in hypoperfused animals compared to controls and showed a proportion of these newly generated cells had differentiated into oligodendrocytes in a subset of animals. Expression of GPR17, a receptor important for the regulation of OPC differentiation following injury, was decreased following short term hypoperfusion. Despite changes to oligodendrocyte numbers there were no changes to the myelin sheath as revealed by ultrastructural assessment and fluoromyelin however axon-glial integrity was disrupted after both 3 days and 1 month hypoperfusion. Taken together, our results demonstrate the initial vulnerability of oligodendroglial pools to modest reductions in blood flow and highlight the regenerative capacity of these cells. PMID:24498301

  18. Chronic alcohol intake promotes tumor growth in a diethylnitrosamine-induced hepatocarcinogenesis mouse model through increased Wnt/Beta-catenin signaling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ethanol (EtOH) metabolism is involved in both initiating and promoting mechanisms in hepatocellular carcinoma progression in chronic alcoholics. In this study, we developed a mouse model to test the hypothesis that chronic EtOH consumption promotes tumor growth irrespective of EtOH-related initiati...

  19. Caffeic Acid Inhibits Chronic UVB-Induced Cellular Proliferation Through JAK-STAT3 Signaling in Mouse Skin.

    PubMed

    Agilan, Balupillai; Rajendra Prasad, N; Kanimozhi, Govindasamy; Karthikeyan, Ramasamy; Ganesan, Muthusamy; Mohana, Shanmugam; Velmurugan, Devadasan; Ananthakrishnan, Dhanapalan

    2016-05-01

    Signal transducers and activators of transcription 3 (STAT3) play a critical role in inflammation, proliferation and carcinogenesis. Inhibition of JAK-STAT3 signaling is proved to be a novel target for prevention of UVB-induced skin carcinogenesis. In this study, chronic UVB irradiation (180 mJ cm(-2) ; weekly thrice for 30 weeks) induces the expression of IL-10 and JAK1 that eventually activates the STAT3 which leads to the transcription of proliferative and antiapoptotic markers such as PCNA, Cyclin-D1, Bcl2 and Bcl-xl, respectively. Caffeic acid (CA) inhibits JAK-STAT3 signaling, thereby induces apoptotic cell death by upregulating Bax, Cytochrome-C, Caspase-9 and Caspase-3 expression in mouse skin. Furthermore, TSP-1 is an antiangiogeneic protein, which is involved in the inhibition of angiogenesis and proliferation. Chronic UVB exposure decreased the expression of TSP-1 and pretreatment with CA prevented the UVB-induced loss of TSP-1 in UVB-irradiated mouse skin. Thus, CA offers protection against UVB-induced photocarcinogenesis probably through modulating the JAK-STAT3 in the mouse skin. PMID:27029485

  20. Chronic mild stress facilitates melanoma tumor growth in mouse lines selected for high and low stress-induced analgesia.

    PubMed

    Ragan, Agnieszka R; Lesniak, Anna; Bochynska-Czyz, Marta; Kosson, Anna; Szymanska, Hanna; Pysniak, Kazimiera; Gajewska, Marta; Lipkowski, Andrzej W; Sacharczuk, Mariusz

    2013-09-01

    Both chronic stress conditions and hyperergic reaction to environmental stress are known to enhance cancer susceptibility. We described two mouse lines that displayed high (HA) and low (LA) swim stress-induced analgesia (SSIA) to investigate the relationship between inherited differences in sensitivity to stress and proneness to an increased growth rate of subcutaneously inoculated melanoma. These lines display several genetic and physiological differences, among which distinct sensitivity to mutagens and susceptibility to cancer are especially noticeable. High analgesic mice display high proneness both to stress and a rapid local spread of B16F0 melanoma. However, stress-resistant LA mice do not develop melanoma tumors after inoculation, or if so, tumors regress spontaneously. We found that the chronic mild stress (CMS) procedure leads to enhanced interlinear differences in melanoma susceptibility. Tumors developed faster in stress conditions in both lines. However, LA mice still displayed a tendency for spontaneous regression, and 50% of LA mice did not develop a tumor, even under stressed conditions. Moreover, we showed that chronic stress, but not tumor progression, induces depressive behavior, which may be an important clue in cancer therapy. Our results clearly indicate how the interaction between genetic susceptibility to stress and environmental stress determine the risk and progression of melanoma. To our knowledge, HA/LA mouse lines are the first animal models of distinct melanoma progression mediated by inherited differences in stress reactivity. PMID:23688070

  1. Hypoxic control of metastasis.

    PubMed

    Rankin, Erinn B; Giaccia, Amato J

    2016-04-01

    Metastatic disease is the leading cause of cancer-related deaths and involves critical interactions between tumor cells and the microenvironment. Hypoxia is a potent microenvironmental factor promoting metastatic progression. Clinically, hypoxia and the expression of the hypoxia-inducible transcription factors HIF-1 and HIF-2 are associated with increased distant metastasis and poor survival in a variety of tumor types. Moreover, HIF signaling in malignant cells influences multiple steps within the metastatic cascade. Here we review research focused on elucidating the mechanisms by which the hypoxic tumor microenvironment promotes metastatic progression. These studies have identified potential biomarkers and therapeutic targets regulated by hypoxia that could be incorporated into strategies aimed at preventing and treating metastatic disease. PMID:27124451

  2. [Hypoxic lung failure].

    PubMed

    David, S; Wiesner, O

    2016-04-01

    Hypoxic lung failure is among the major indications for patients' referral to intensive care units either for surveillance or if necessary therapy. There are a vast number of pathophysiological causes of lung failure and the optimal treatment highly depends on the underlying pathology; therefore, no standard algorithm exists. So-called acute respiratory distress syndrome (ARDS) represents a very severe manifestation of hypoxemic lung failure that is of particular relevance for intensivists and is therefore the focus of this review. In addition to fundamental pathophysiology of lung injury, the article also focuses on established and modern treatment strategies. Moreover, we will briefly highlight innovative concepts of ARDS treatment that might become relevant in the future. PMID:27084180

  3. Hypoxic control of metastasis

    PubMed Central

    Rankin, Erinn B.; Giaccia, Amato J.

    2016-01-01

    Metastatic disease is the leading cause of cancer-related deaths and involves critical interactions between tumor cells and the microenvironment. Hypoxia is a potent microenvironmental factor promoting metastatic progression. Clinically, hypoxia and the expression of the hypoxia-inducible transcription factors HIF-1 and HIF-2 are associated with increased distant metastasis and poor survival in a variety of tumor types. Moreover, HIF signaling in malignant cells influences multiple steps within the metastatic cascade. Here we review research focused on elucidating the mechanisms by which the hypoxic tumor microenvironment promotes metastatic progression. These studies have identified potential biomarkers and therapeutic targets regulated by hypoxia that could be incorporated into strategies aimed at preventing and treating metastatic disease. PMID:27124451

  4. Antidepressant-like effects of aqueous extract from Cecropia pachystachya leaves in a mouse model of chronic unpredictable stress.

    PubMed

    Gazal, Marta; Ortmann, Caroline Flach; Martins, Fernanda Amelia; Streck, Emilio Luiz; Quevedo, João; de Campos, Angela Machado; Stefanello, Francieli M; Kaster, Manuella P; Ghisleni, Gabriele; Reginatto, Flávio Henrique; Lencina, Claiton L

    2014-09-01

    Chronic stressful stimuli influence disease susceptibility to depression, cardiovascular, metabolic and neurodegenerative disorders. The present work investigated antidepressant and antioxidant properties of the aqueous extract from Cecropia pachystachya in a mouse model of chronic unpredictable stress (CUS). Our results indicated that acute administration of the aqueous extract (AE) from C. pachystachya (200 and 400mg/kg, p.o.) produced an antidepressant-like effect in the forced swimming test (FST). The chronic treatment with C. pachystachya extract (200mg/kg, p.o., for 14 days) prevented the depressant-like effect but not the anxiogenic effect induced by CUS. In addition to the behavioral modifications, the 14 days of CUS increased lipid peroxidation in the hippocampus (HP) and prefrontal cortex (PFC), decreased total thiol content and glutathione peroxidase activity in the HP. C. pachystachya AE administration during CUS protocol was able to prevent the oxidative damage induced by stress. However, no changes were observed in the activity of the antioxidant enzymes superoxide dismutase and catalase in the above cited brain areas after the stress protocol and treatment. Our results suggest that C. pachystachya prevented both depressive behavior and oxidative damage induced by CUS, supporting its neuroprotective potential against behavioral and biochemical dysfunctions induced by chronic stress. PMID:25108233

  5. Absence of α4 but not β2 integrins restrains development of chronic allergic asthma using mouse genetic models

    PubMed Central

    Banerjee, Ena Ray; Jiang, Yi; Henderson, William R.; Latchman, Yvette; Papayannopoulou, Thalia

    2013-01-01

    Objective Chronic asthma is characterized by ongoing recruitment of inflammatory cells and airway hyperresponsiveness leading to structural airway remodeling. Although α4β1 and β2 integrins regulate leukocyte migration in inflammatory diseases and play decisive roles in acute asthma, their role has not been explored under the chronic asthma setting. To extend our earlier studies with α4Δ/Δ and β2−/− mice, which showed that both a4 and b2 integrins have nonredundant regulatory roles in acute ovalbumin (OVA)-induced asthma, we explored to what extent these molecular pathways control development of structural airway remodeling in chronic asthma. Materials and Methods Control, α4Δ/Δ, and β2−/−mouse groups, sensitized by intraperitoneal OVA as allergen, received intratracheal OVA periodically over days 8 to 55 to induce a chronic asthma phenotype. Post-OVA assessment of inflammation and pulmonary function (airway hyperresponsiveness), together with airway modeling measured by goblet cell metaplasia, collagen content of lung, and transforming growth factor β1 expression in lung homogenates, were evaluated. Results In contrast to control and β2−/− mice, α4Δ/Δ mice failed to develop and maintain the composite chronic asthma phenotype evaluated as mentioned and subepithelial collagen content was comparable to baseline. These data indicate that β2 integrins, although required for inflammatory migration in acute asthma, are dispensable for structural remodeling in chronic asthma. Conclusion α4 integrins appear to have a regulatory role in directing transforming growth factor β-induced collagen deposition and structural alterations in lung architecture likely through interactions of Th2 cells, eosinophils, or mast cells with endothelium, resident airway cells, and/or extracellular matrix. PMID:19463772

  6. Chronic Fluoxetine Induces the Enlargement of Perforant Path-Granule Cell Synapses in the Mouse Dentate Gyrus

    PubMed Central

    Kitahara, Yosuke; Ohta, Keisuke; Hasuo, Hiroshi; Shuto, Takahide; Kuroiwa, Mahomi; Sotogaku, Naoki; Togo, Akinobu; Nakamura, Kei-ichiro; Nishi, Akinori

    2016-01-01

    A selective serotonin reuptake inhibitor is the most commonly prescribed antidepressant for the treatment of major depression. However, the mechanisms underlying the actions of selective serotonin reuptake inhibitors are not fully understood. In the dentate gyrus, chronic fluoxetine treatment induces increased excitability of mature granule cells (GCs) as well as neurogenesis. The major input to the dentate gyrus is the perforant path axons (boutons) from the entorhinal cortex (layer II). Through voltage-sensitive dye imaging, we found that the excitatory neurotransmission of the perforant path synapse onto the GCs in the middle molecular layer of the mouse dentate gyrus (perforant path-GC synapse) is enhanced after chronic fluoxetine treatment (15 mg/kg/day, 14 days). Therefore, we further examined whether chronic fluoxetine treatment affects the morphology of the perforant path-GC synapse, using FIB/SEM (focused ion beam/scanning electron microscopy). A three-dimensional reconstruction of dendritic spines revealed the appearance of extremely large-sized spines after chronic fluoxetine treatment. The large-sized spines had a postsynaptic density with a large volume. However, chronic fluoxetine treatment did not affect spine density. The presynaptic boutons that were in contact with the large-sized spines were large in volume, and the volumes of the mitochondria and synaptic vesicles inside the boutons were correlated with the size of the boutons. Thus, the large-sized perforant path-GC synapse induced by chronic fluoxetine treatment contains synaptic components that correlate with the synapse size and that may be involved in enhanced glutamatergic neurotransmission. PMID:26788851

  7. Chronic Fluoxetine Induces the Enlargement of Perforant Path-Granule Cell Synapses in the Mouse Dentate Gyrus.

    PubMed

    Kitahara, Yosuke; Ohta, Keisuke; Hasuo, Hiroshi; Shuto, Takahide; Kuroiwa, Mahomi; Sotogaku, Naoki; Togo, Akinobu; Nakamura, Kei-ichiro; Nishi, Akinori

    2016-01-01

    A selective serotonin reuptake inhibitor is the most commonly prescribed antidepressant for the treatment of major depression. However, the mechanisms underlying the actions of selective serotonin reuptake inhibitors are not fully understood. In the dentate gyrus, chronic fluoxetine treatment induces increased excitability of mature granule cells (GCs) as well as neurogenesis. The major input to the dentate gyrus is the perforant path axons (boutons) from the entorhinal cortex (layer II). Through voltage-sensitive dye imaging, we found that the excitatory neurotransmission of the perforant path synapse onto the GCs in the middle molecular layer of the mouse dentate gyrus (perforant path-GC synapse) is enhanced after chronic fluoxetine treatment (15 mg/kg/day, 14 days). Therefore, we further examined whether chronic fluoxetine treatment affects the morphology of the perforant path-GC synapse, using FIB/SEM (focused ion beam/scanning electron microscopy). A three-dimensional reconstruction of dendritic spines revealed the appearance of extremely large-sized spines after chronic fluoxetine treatment. The large-sized spines had a postsynaptic density with a large volume. However, chronic fluoxetine treatment did not affect spine density. The presynaptic boutons that were in contact with the large-sized spines were large in volume, and the volumes of the mitochondria and synaptic vesicles inside the boutons were correlated with the size of the boutons. Thus, the large-sized perforant path-GC synapse induced by chronic fluoxetine treatment contains synaptic components that correlate with the synapse size and that may be involved in enhanced glutamatergic neurotransmission. PMID:26788851

  8. Chronic Subordinate Colony Housing Paradigm: A Mouse Model to Characterize the Consequences of Insufficient Glucocorticoid Signaling

    PubMed Central

    Langgartner, Dominik; Füchsl, Andrea M.; Uschold-Schmidt, Nicole; Slattery, David A.; Reber, Stefan O.

    2015-01-01

    Chronic, in particular chronic psychosocial, stress is a burden of modern societies and known to be a risk factor for numerous somatic and affective disorders (in detail referenced below). However, based on the limited existence of appropriate, and clinically relevant, animal models for studying the effects of chronic stress, the detailed behavioral, physiological, neuronal, and immunological mechanisms linking stress and such disorders are insufficiently understood. To date, most chronic stress studies in animals employ intermittent exposure to the same (homotypic) or to different (heterotypic) stressors of varying duration and intensity. Such models are only of limited value, since they do not adequately reflect the chronic and continuous situation that humans typically experience. Furthermore, application of different physical or psychological stimuli renders comparisons to the mainly psychosocial stressors faced by humans, as well as between the different stress studies almost impossible. In contrast, rodent models of chronic psychosocial stress represent situations more akin to those faced by humans and consequently seem to hold more clinical relevance. Our laboratory has developed a model in which mice are exposed to social stress for 19 continuous days, namely the chronic subordinate colony housing (CSC) paradigm, to help bridge this gap. The main aim of the current review article is to provide a detailed summary of the behavioral, physiological, neuronal, and immunological consequences of the CSC paradigm, and wherever possible relate the findings to other stress models and to the human situation. PMID:25755645

  9. VEGF receptors mediate hypoxic remodeling of adult ovine carotid arteries.

    PubMed

    Adeoye, Olayemi O; Bouthors, Vincent; Hubbell, Margaret C; Williams, James M; Pearce, William J

    2014-10-01

    Recent studies suggest that VEGF contributes to hypoxic remodeling of arterial smooth muscle, although hypoxia produces only transient increases in VEGF that return to normoxic levels despite sustained changes in arterial structure and function. To explore how VEGF might contribute to long-term hypoxic vascular remodeling, this study explores the hypothesis that chronic hypoxia produces sustained increases in smooth muscle VEGF receptor density that mediate long-term vascular effects of hypoxia. Carotid arteries from adult sheep maintained at sea level or altitude (3,820 m) for 110 days were harvested and denuded of endothelium. VEGF levels were similar in chronically hypoxic and normoxic arteries, as determined by immunoblotting. In contrast, VEGF receptor levels were significantly increased by 107% (VEGF-R1) and 156% (VEGF-R2) in hypoxic compared with normoxic arteries. In arteries that were organ cultured 24 h with 3 nM VEGF, VEGF replicated effects of hypoxia on abundances of smooth muscle α actin (SMαA), myosin light chain kinase (MLCK), and MLC20 and the effects of hypoxia on colocalization of MLC20 with SMαA, as measured via confocal microscopy. VEGF did not replicate the effects of chronic hypoxia on colocalization of MLCK with SMαA or MLCK with MLC20, suggesting that VEGF's role in hypoxic remodeling is highly protein specific, particularly for contractile protein organization. VEGF effects in organ culture were inhibited by VEGF receptor blockers vatalinib (240 nM) and dasatinib (6.3 nM). These findings support the hypothesis that long-term upregulation of VEGF receptors help mediate sustained effects of hypoxia on the abundance and colocalization of contractile proteins in arterial smooth muscle. PMID:25038104

  10. Hypoxic apnea and gasping.

    PubMed Central

    Guntheroth, W G; Kawabori, I

    1975-01-01

    We have tested the hypothesis that severe lypoxia causes apnea, regardless of the arterial CO2 and pH, and that extreme hypoxia causes gasping. Acute experiments with airway occlusion and with low inspired oxygen (FIo2) were performed on anesthetized adult dogs and monkeys. Arterial oxygen saturation was recorded continuously with fiberoptic oximetry, and Pco2 by an electrode catheter. In addition, blood samples were obtained for Po2, Pco2, and pH. Apnea was induced regularly when the Pao2 fell below 10 torr, whether the Paco2 was high with asphyxia (63 torr) or low (26 torr) with low FIo2. Similarly, the Pao2 at apnea was the same whether the pH was 7.17 with asphyxic hypoxia or 7.46 with hypoxic hypoxia. Gasping occurred at even lower Pao2 (below 5 torr) after 1 or 2 min of apnea. Gasping promptly restored the Pao2 to levels of moderate hypoxia (over 30 torr) which permitted resumption of regular respiration, with gradual elimination of the gasping. Fetal monkeys at term were studied in a similar manner from the moment of cord clamping. Their blood gases with apnea were quite similar to adult values in the narrow range of Pao2 and the wide range of Paco2 and pH. In the fetus, gasping was less immediately effective in improving arterial oxygen, but more persistent than in the adult. Regular respirations would not develop in the absence of oxygen in either the fetus or adult animal. Images PMID:811688

  11. Chronic Intake of Japanese Sake Mediates Radiation-Induced Metabolic Alterations in Mouse Liver

    PubMed Central

    Nakajima, Tetsuo; Vares, Guillaume; Wang, Bing; Nenoi, Mitsuru

    2016-01-01

    Sake is a traditional Japanese alcoholic beverage that is gaining popularity worldwide. Although sake is reported to have beneficial health effects, it is not known whether chronic sake consumption modulates health risks due to radiation exposure or other factors. Here, the effects of chronic administration of sake on radiation-induced metabolic alterations in the livers of mice were evaluated. Sake (junmai-shu) was administered daily to female mice (C3H/He) for one month, and the mice were exposed to fractionated doses of X-rays (0.75 Gy/day) for the last four days of the sake administration period. For comparative analysis, a group of mice were administered 15% (v/v) ethanol in water instead of sake. Metabolites in the liver were analyzed by capillary electrophoresis-time-of-flight mass spectrometry one day following the last exposure to radiation. The metabolite profiles of mice chronically administered sake in combination with radiation showed marked changes in purine, pyrimidine, and glutathione (GSH) metabolism, which were only partially altered by radiation or sake administration alone. Notably, the changes in GSH metabolism were not observed in mice treated with radiation following chronic administration of 15% ethanol in water. Changes in several metabolites, including methionine and valine, were induced by radiation alone, but were not detected in the livers of mice who received chronic administration of sake. In addition, the chronic administration of sake increased the level of serum triglycerides, although radiation exposure suppressed this increase. Taken together, the present findings suggest that chronic sake consumption promotes GSH metabolism and anti-oxidative activities in the liver, and thereby may contribute to minimizing the adverse effects associated with radiation. PMID:26752639

  12. An autoradiographic analysis of cholinergic receptors in mouse brain after chronic nicotine treatment

    SciTech Connect

    Pauly, J.R.; Marks, M.J.; Gross, S.D.; Collins, A.C. )

    1991-09-01

    Quantitative autoradiographic procedures were used to examine the effects of chronic nicotine infusion on the number of central nervous system nicotinic cholinergic receptors. Female DBA mice were implanted with jugular cannulas and infused with saline or various doses of nicotine (0.25, 0.5, 1.0 or 2.0 mg/kg/hr) for 10 days. The animals were then sacrificed and the brains were removed and frozen in isopentane. Cryostat sections were collected and prepared for autoradiographic procedures as previously described. Nicotinic cholinergic receptors were labeled with L-(3H)nicotine or alpha-(125I)bungarotoxin; (3H)quinuclidinyl benzilate was used to measure muscarinic cholinergic receptor binding. Chronic nicotine infusion increased the number of sites labeled by (3H)nicotine in most brain areas. However, the extent of the increase in binding as well as the dose-response curves for the increase were widely different among brain regions. After the highest treatment dose, binding was increased in 67 of 86 regions measured. Septal and thalamic regions were most resistant to change. Nicotinic binding measured by alpha-(125I)bungarotoxin also increased after chronic treatment, but in a less robust fashion. At the highest treatment dose, only 26 of 80 regions were significantly changes. Muscarinic binding was not altered after chronic nicotine treatment. These data suggest that brain regions are not equivalent in the mechanisms that regulate alterations in nicotinic cholinergic receptor binding after chronic nicotine treatment.

  13. SCID mouse models of acute and relapsing chronic Toxoplasma gondii infections.

    PubMed Central

    Johnson, L L

    1992-01-01

    Lymphodeficient scid/scid (SCID) mice died from acute infection with a strain of Toxoplasma gondii that causes chronic infection with mild symptoms in immunocompetent non-SCID mice. However, most SCID mice reconstituted with spleen cells from immunocompetent mice 1 month prior to T. gondii infection survived in good health after a transient period during which they appeared ill. Unreconstituted SCID mice given sulfadiazine in their drinking water from day 10 of Toxoplasma infection onward survived the acute phase of infection and lived for many weeks without overt symptoms. Histological examination revealed Toxoplasma cysts in their brains. However, if sulfadiazine was withdrawn from the drinking water of these chronically infected SCID mice, the mice died within 1 week with large numbers of trophozoites throughout their brains. These findings establish SCID mice as a potentially useful resource with which to study various aspects of immunological control of T. gondii infection during either its acute or chronic phase. Furthermore, the ability to produce chronic infections with avirulent T. gondii in SCID mice and to cause acute relapsing infections at will suggests that SCID mice may be helpful in evaluating potential therapies for acute and chronic T. gondii infections in immunocompromised patients. Images PMID:1500181

  14. Generation of Functional Neutrophils from a Mouse Model of X-Linked Chronic Granulomatous Disorder Using Induced Pluripotent Stem Cells

    PubMed Central

    Mukherjee, Sayandip; Santilli, Giorgia; Blundell, Michael P.; Navarro, Susana; Bueren, Juan A.; Thrasher, Adrian J.

    2011-01-01

    Murine models of human genetic disorders provide a valuable tool for investigating the scope for application of induced pluripotent stem cells (iPSC). Here we present a proof-of-concept study to demonstrate generation of iPSC from a mouse model of X-linked chronic granulomatous disease (X-CGD), and their successful differentiation into haematopoietic progenitors of the myeloid lineage. We further demonstrate that additive gene transfer using lentiviral vectors encoding gp91phox is capable of restoring NADPH-oxidase activity in mature neutrophils derived from X-CGD iPSC. In the longer term, correction of iPSC from human patients with CGD has therapeutic potential not only through generation of transplantable haematopoietic stem cells, but also through production of large numbers of autologous functional neutrophils. PMID:21408614

  15. No exacerbation but impaired anti-viral mechanisms in a rhinovirus-chronic allergic asthma mouse model.

    PubMed

    Rochlitzer, Sabine; Hoymann, Heinz-Gerd; Müller, Meike; Braun, Armin

    2014-01-01

    Severe asthma and viral-induced asthma exacerbations represent a high unmet medical need as no therapy is currently available for these patients. HRV (human rhinovirus) is prominently associated with asthma exacerbations in humans. The aim of the present study was to establish a mouse model of severe asthma with additional rhinovirus infection to investigate the interplay between chronic allergic airway inflammation and acute respiratory viral infection. Balb/c mice were sensitized with HDM (house dust mite) extract (25 μg in 50 μl of saline) by i.n. (intranasal) delivery to the lung over 7 weeks. HRV1B (HRV serotype 1B) inoculation was performed i.n. on the last 3 days. Therapeutic treatment with FP (fluticasone propionate) was performed to assess steroid efficacy. Lung resistance was measured invasively to assess AHR (airway hyper-responsiveness). BAL (bronchoalveolar lavage) differential cell count, cytokines, lung histology and the proliferative and cytokine response of MLN (mediastinal lymph node) cells upon in vitro restimulation were analysed. Chronic HDM application induced a strong Th2-skewed eosinophilic airway inflammation and AHR, which was not exacerbated by superimposed HRV1B infection. Therapeutic steroid intervention in the chronic HDM model reduced BAL eosinophil cell counts, cytokine levels and AHR, while neutrophil numbers were unaffected. Steroid efficacy against inflammatory readouts was maintained during additional HRV1B infection. Animals with chronic allergic airway inflammation exhibited a diminished immune response towards superimposed HRV1B infection compared with HRV1B alone, as induction of the anti-viral and pro-inflammatory cytokines IFN (interferon)-α, IFN-γ and IL (interleukin)-12 were suppressed. Although superimposed HRV1B infection did not provoke asthma exacerbation in this severe model, a deficient anti-viral immune response to HRV1B was present under chronic allergic airway inflammatory conditions. Thus, this model is

  16. A Chronic Longitudinal Characterization of Neurobehavioral and Neuropathological Cognitive Impairment in a Mouse Model of Gulf War Agent Exposure

    PubMed Central

    Zakirova, Zuchra; Crynen, Gogce; Hassan, Samira; Abdullah, Laila; Horne, Lauren; Mathura, Venkatarajan; Crawford, Fiona; Ait-Ghezala, Ghania

    2016-01-01

    Gulf War Illness (GWI) is a chronic multisymptom illness with a central nervous system component that includes memory impairment as well as neurological and musculoskeletal deficits. Previous studies have shown that in the First Persian Gulf War conflict (1990–1991) exposure to Gulf War (GW) agents, such as pyridostigmine bromide (PB) and permethrin (PER), were key contributors to the etiology of GWI. For this study, we used our previously established mouse model of GW agent exposure (10 days PB+PER) and undertook an extensive lifelong neurobehavioral characterization of the mice from 11 days to 22.5 months post exposure in order to address the persistence and chronicity of effects suffered by the current GWI patient population, 24 years post-exposure. Mice were evaluated using a battery of neurobehavioral testing paradigms, including Open Field Test (OFT), Elevated Plus Maze (EPM), Three Chamber Testing, Radial Arm Water Maze (RAWM), and Barnes Maze (BM) Test. We also carried out neuropathological analyses at 22.5 months post exposure to GW agents after the final behavioral testing. Our results demonstrate that PB+PER exposed mice exhibit neurobehavioral deficits beginning at the 13 months post exposure time point and continuing trends through the 22.5 month post exposure time point. Furthermore, neuropathological changes, including an increase in GFAP staining in the cerebral cortices of exposed mice, were noted 22.5 months post exposure. Thus, the persistent neuroinflammation evident in our model presents a platform with which to identify novel biological pathways, correlating with emergent outcomes that may be amenable to therapeutic targeting. Furthermore, in this work we confirmed our previous findings that GW agent exposure causes neuropathological changes, and have presented novel data which demonstrate increased disinhibition, and lack of social preference in PB+PER exposed mice at 13 months after exposure. We also extended upon our previous work to

  17. Chronic serotonin-norepinephrine reuptake transporter inhibition modifies basal respiratory output in adult mouse in vitro and in vivo

    PubMed Central

    Warren, Kelly A.; Solomon, Irene C.

    2012-01-01

    Respiratory disturbances are a common feature of panic disorder and present as breathing irregularity, hyperventilation, and increased sensitivity to carbon dioxide. Common therapeutic interventions, such as tricyclic (TCA) and selective serotonin reuptake inhibitor (SSRI) antidepressants, have been shown to ameliorate not only the psychological components of panic disorder but also the respiratory disturbances. These drugs are also prescribed for generalized anxiety and depressive disorders, neither of which are characterized by respiratory disturbances, and previous studies have demonstrated that TCAs and SSRIs exert effects on basal respiratory activity in animal models without panic disorder symptoms. Whether serotonin-norepinephrine reuptake inhibitors (SNRIs) have similar effects on respiratory activity remains to be determined. Therefore, the current study was designed to investigate the effects of chronic administration of the SNRI antidepressant venlafaxine (VHCL) on basal respiratory output. For these experiments, we recorded phrenic nerve discharge in an in vitro arterially-perfused adult mouse preparation and diaphragm electromyogram (EMG) activity in an in vivo urethane-anesthetized adult mouse preparation. We found that following 28-d VHCL administration, basal respiratory burst frequency was markedly reduced due to an increase in expiratory duration (TE), and the inspiratory duty cycle (TI/Ttot) was significantly shortened. In addition, post-inspiratory and spurious expiratory discharges were seen in vitro. Based on our observations, we suggest that drugs capable of simultaneously blocking both 5-HT and NE reuptake transporters have the potential to influence the respiratory control network in patients using SNRI therapy. PMID:22871263

  18. Enhanced Expression of TREK-1 Is Related with Chronic Constriction Injury of Neuropathic Pain Mouse Model in Dorsal Root Ganglion.

    PubMed

    Han, Hyo Jo; Lee, Seung Wook; Kim, Gyu-Tae; Kim, Eun-Jin; Kwon, Byeonghun; Kang, Dawon; Kim, Hyun Jeong; Seo, Kwang-Suk

    2016-05-01

    Neuropathic pain is a complex state showing increased pain response with dysfunctional inhibitory neurotransmission. The TREK family, one of the two pore domain K⁺ (K2P) channel subgroups were focused among various mechanisms of neuropathic pain. These channels influence neuronal excitability and are thought to be related in mechano/thermosensation. However, only a little is known about the expression and role of TREK-1 and TREK-2, in neuropathic pain. It is performed to know whether TREK-1 and/ or 2 are positively related in dorsal root ganglion (DRG) of a mouse neuropathic pain model, the chronic constriction injury (CCI) model. Following this purpose, Reverse Transcription Polymerase Chain Reaction (RT-PCR) and western blot analyses were performed using mouse DRG of CCI model and compared to the sham surgery group. Immunofluorescence staining of isolectin- B4 (IB4) and TREK were performed. Electrophysiological recordings of single channel currents were analyzed to obtain the information about the channel. Interactions with known TREK activators were tested to confirm the expression. While both TREK-1 and TREK-2 mRNA were significantly overexpressed in DRG of CCI mice, only TREK-1 showed significant increase (~9 fold) in western blot analysis. The TREK-1-like channel recorded in DRG neurons of the CCI mouse showed similar current-voltage relationship and conductance to TREK-1. It was easily activated by low pH solution (pH 6.3), negative pressure, and riluzole. Immunofluorescence images showed the expression of TREK-1 was stronger compared to TREK-2 on IB4 positive neurons. These results suggest that modulation of the TREK-1 channel may have beneficial analgesic effects in neuropathic pain patients. PMID:27133259

  19. Enhanced Expression of TREK-1 Is Related with Chronic Constriction Injury of Neuropathic Pain Mouse Model in Dorsal Root Ganglion

    PubMed Central

    Han, Hyo Jo; Lee, Seung Wook; Kim, Gyu-Tae; Kim, Eun-Jin; Kwon, Byeonghun; Kang, Dawon; Kim, Hyun Jeong; Seo, Kwang-Suk

    2016-01-01

    Neuropathic pain is a complex state showing increased pain response with dysfunctional inhibitory neurotransmission. The TREK family, one of the two pore domain K+ (K2P) channel subgroups were focused among various mechanisms of neuropathic pain. These channels influence neuronal excitability and are thought to be related in mechano/thermosensation. However, only a little is known about the expression and role of TREK-1 and TREK-2, in neuropathic pain. It is performed to know whether TREK-1 and/or 2 are positively related in dorsal root ganglion (DRG) of a mouse neuropathic pain model, the chronic constriction injury (CCI) model. Following this purpose, Reverse Transcription Polymerase Chain Reaction (RT-PCR) and western blot analyses were performed using mouse DRG of CCI model and compared to the sham surgery group. Immunofluorescence staining of isolectin-B4 (IB4) and TREK were performed. Electrophysiological recordings of single channel currents were analyzed to obtain the information about the channel. Interactions with known TREK activators were tested to confirm the expression. While both TREK-1 and TREK-2 mRNA were significantly overexpressed in DRG of CCI mice, only TREK-1 showed significant increase (∼9 fold) in western blot analysis. The TREK-1-like channel recorded in DRG neurons of the CCI mouse showed similar current-voltage relationship and conductance to TREK-1. It was easily activated by low pH solution (pH 6.3), negative pressure, and riluzole. Immunofluorescence images showed the expression of TREK-1 was stronger compared to TREK-2 on IB4 positive neurons. These results suggest that modulation of the TREK-1 channel may have beneficial analgesic effects in neuropathic pain patients. PMID:27133259

  20. Cardiosphere-derived cell sheet primed with hypoxia improves left ventricular function of chronically infarcted heart

    PubMed Central

    Hosoyama, Tohru; Samura, Makoto; Kudo, Tomoaki; Nishimoto, Arata; Ueno, Koji; Murata, Tomoaki; Ohama, Takashi; Sato, Koichi; Mikamo, Akihito; Yoshimura, Koichi; Li, Tao-Sheng; Hamano, Kimikazu

    2015-01-01

    Cardiosphere-derived cells (CDCs) isolated from postnatal heart tissue are a convenient and efficientresource for the treatment of myocardial infarction. However, poor retention of CDCs in infarcted hearts often causes less than ideal therapeutic outcomes. Cell sheet technology has been developed as a means of permitting longer retention of graft cells, and this therapeutic strategy has opened new avenues of cell-based therapy for severe ischemic diseases. However, there is still scope for improvement before this treatment can be routinely applied in clinical settings. In this study, we investigated whether hypoxic preconditioning enhances the therapeutic efficacy of CDC monolayer sheets. To induce hypoxia priming, CDC monolayer sheets were placed in an incubator adjusted to 2% oxygen for 24 hours, and then preconditioned mouse CDC sheets were implanted into the infarcted heart of old myocardial infarction mouse models. Hypoxic preconditioning of CDC sheets remarkably increased the expression of vascular endothelial growth factor through the PI3-kinase/Akt signaling pathway. Implantation of preconditioned CDC sheets improved left ventricular function inchronically infarcted hearts and reduced fibrosis. The therapeutic efficacy of preconditioned CDC sheets was higher than the CDC sheets that were cultured under normaxia condition. These results suggest that hypoxic preconditioning augments the therapeutic angiogenic and anti-fibrotic activity of CDC sheets. A combination of cell sheets and hypoxic preconditioning offers an attractive therapeutic protocol for CDC transplantation into chronically infarcted hearts. PMID:26885271

  1. Cardiosphere-derived cell sheet primed with hypoxia improves left ventricular function of chronically infarcted heart.

    PubMed

    Hosoyama, Tohru; Samura, Makoto; Kudo, Tomoaki; Nishimoto, Arata; Ueno, Koji; Murata, Tomoaki; Ohama, Takashi; Sato, Koichi; Mikamo, Akihito; Yoshimura, Koichi; Li, Tao-Sheng; Hamano, Kimikazu

    2015-01-01

    Cardiosphere-derived cells (CDCs) isolated from postnatal heart tissue are a convenient and efficientresource for the treatment of myocardial infarction. However, poor retention of CDCs in infarcted hearts often causes less than ideal therapeutic outcomes. Cell sheet technology has been developed as a means of permitting longer retention of graft cells, and this therapeutic strategy has opened new avenues of cell-based therapy for severe ischemic diseases. However, there is still scope for improvement before this treatment can be routinely applied in clinical settings. In this study, we investigated whether hypoxic preconditioning enhances the therapeutic efficacy of CDC monolayer sheets. To induce hypoxia priming, CDC monolayer sheets were placed in an incubator adjusted to 2% oxygen for 24 hours, and then preconditioned mouse CDC sheets were implanted into the infarcted heart of old myocardial infarction mouse models. Hypoxic preconditioning of CDC sheets remarkably increased the expression of vascular endothelial growth factor through the PI3-kinase/Akt signaling pathway. Implantation of preconditioned CDC sheets improved left ventricular function inchronically infarcted hearts and reduced fibrosis. The therapeutic efficacy of preconditioned CDC sheets was higher than the CDC sheets that were cultured under normaxia condition. These results suggest that hypoxic preconditioning augments the therapeutic angiogenic and anti-fibrotic activity of CDC sheets. A combination of cell sheets and hypoxic preconditioning offers an attractive therapeutic protocol for CDC transplantation into chronically infarcted hearts. PMID:26885271

  2. Perfusion of nonventilated lung: failure of hypoxic vasoconstriction

    SciTech Connect

    Sostman, H.D.; Neumann, R.D.; Gottschalk, A.; Greenspan, R.H.

    1983-07-01

    Alveolar hypoxia is a well established cause of regional vasoconstriction such that nonventilated segments are not perfused. The paradoxical situation of retained perfusion of nonventilated lung has seldom been discussed. Three clinical examples are illustrated. In each case coexistent chronic obstructive lung disease may have contributed to this unexpected finding by reducing pulmonary vascular capacity such that blood flow diversion from hypoxic segments was not possible.

  3. Hypoxic Pulmonary Vasoconstriction in Humans

    PubMed Central

    Loubani, Mahmoud; Morice, Alyn H.

    2013-01-01

    Hypoxic pulmonary vasoconstriction is the elegant theory put forward more than six decades ago to explain regional variations in perfusion within the lung in certain animal species in response to localised restrictions in oxygenation. Although considerable progress has been made to describe the phenomenon at the macroscopic level and explain it at the microscopic level, we are far from a universal agreement about the process in humans. This review attempts to highlight some of the important evidence bases of hypoxic pulmonary vasoconstriction in humans and the significant gaps in our knowledge that would need bridging. PMID:24024204

  4. Chronic ethanol exposure inhibits distraction osteogenesis in a mouse model: role of the TNF signaling axis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tumor necrosis factor-alpha (TNF-alpha) is an inflammatory cytokine that modulates osteoblastogenesis. In addition, the demonstrated inhibitory effects of chronic ethanol exposure on direct bone formation in rats are hypothetically mediated by TNF-alpha signaling. The effects in mice are unreported....

  5. Astrocytic adaptation during cerebral angiogenesis follows the new vessel formation induced through chronic hypoxia in adult mouse cortex

    NASA Astrophysics Data System (ADS)

    Masamoto, Kazuto; Kanno, Iwao

    2014-03-01

    We examined longitudinal changes of the neuro-glia-vascular unit during cerebral angiogenesis induced through chronic hypoxia in the adult mouse cortex. Tie2-GFP mice in which the vascular endothelial cells expressed green fluorescent proteins (GFP) were exposed to chronic hypoxia, while the spatiotemporal developments of the cortical capillary sprouts and the neighboring astrocytic remodeling were characterized with repeated two-photon microscopy. The capillary sprouts appeared at early phases of the hypoxia adaptation (1-2 weeks), while the morphological changes of the astrocytic soma and processes were not detected in this phase. In the later phases of the hypoxia adaptation (> 2 weeks), the capillary sprouts created a new connection with existing capillaries, and its neighboring astrocytes extended their processes to the newly-formed vessels. The findings show that morphological adaptation of the astrocytes follow the capillary development during the hypoxia adaptation, which indicate that the newly-formed vessels provoke cellular interactions with the neighboring astrocytes to strengthen the functional blood-brain barrier.

  6. Diazepam administration prevents testosterone decrease and lipofuscin accumulation in testis of mouse exposed to chronic noise stress.

    PubMed

    Ruffoli, R; Carpi, A; Giambelluca, M A; Grasso, L; Scavuzzo, M C; Giannessi F, F

    2006-10-01

    Lipofuscin is an autofluorescent and undegradable material, which accumulates in tissues during ageing and under different types of stress. Among these, oxidative stress represents a major trigger for lipofuscin formation. However, prolonged noise exposure is also an effective stressful stimuli. Diazepam may inhibit lipofuscinogenesis in liver and prevent the noise-induced reduction of the steroidogenesis in the adrenal gland. The aim of the study was to ascertain whether chronic noise exposure causes lipofuscin accumulation in mouse testis, and to evaluate the effects of diazepam administration. Eight-week old mice were either exposed for 6 weeks (6 h day(-1)) to white-noise (group A), or received diazepam (3 mg kg(-1), i.p.) before noise exposures (group B), while a further group was used as control (group C). Light fluorescence and transmission electron microscopy revealed lipofuscin in large amounts in the Leydig cells in mice of group A, which concomitantly had low serum testosterone levels; pre-treatment with diazepam occluded both effects. The present study indicates that: (i) chronic noise exposure causes lipofuscin accumulation at the level of the Leydig cells and a decrease in testosterone; (ii) all these effects are suppressed by pre-treatment with diazepam. As the Leydig cells represent the only cellular type of the interstitial testicular tissue having peripheral benzodiazepine receptors, these results could be explained by the capacity of the peripheral benzodiazepine receptors to prevent reactive oxygen species damage and to increase the resistance of these cells to oxidative stress. PMID:16961568

  7. Chronic hemodynamic unloading regulates the morphologic development of newborn mouse hearts transplanted into the ear of isogeneic adult mice.

    PubMed Central

    Rossi, M. A.

    1992-01-01

    The morphologic development of newborn mouse hearts transplanted into the pinna of the ears of isogeneic adult mice was assessed in comparison to in situ ventricular myocardium of recipients. The grafted hearts became vascularized from the auricular artery at the base of the ear, and although these preparations appeared not to be intrinsically innervated, most of them showed grossly visible pulsatile activity. Since they were not subjected to hemodynamic load due to working against a pressure gradient, this technique provided an interesting experimental model for studies on the growth of chronically unloaded tissue. The ultrastructure of the myocardium from neonatal mouse hearts, which were fixed immediately after dissection, revealed no differences in comparison to previously published observations. By 2 months, there was virtually no change in the myocardial cell size as compared with newborn mouse cardiac tissue. The heterotopic hearts showed a mature ultrastructural appearance, with parallel bands of myofibrils alternating with rows of mitochondria and differentiated intercalated discs comparable to in situ myocardium. The interstitial space was widened due to fibrous tissue, with activated fibroblasts and a few mononuclear cells. In contrast, by 6 months after transplantation, the heterotopic myocardium showed a dispersion of the measured cell diameter of myocytes, with atrophy of a certain population of cells and hypertrophy in others; nevertheless, the mean cell diameter was similar to that observed in 2-month grafts. The myocytes showed significant dissociation from each other in fibrous tissue and a cellular infiltrate composed predominantly of mononuclear cells, and greater variability of the parallel arrangement of cells. They often contained myofibrils coursing in different directions rather than in parallel. Normal-sized or predominantly atrophic degenerated myocytes, characterized by a wide variety of ultrastructural alterations, were present. By 12

  8. Effect of Hyssopus officinalis L. on inhibiting airway inflammation and immune regulation in a chronic asthmatic mouse model

    PubMed Central

    MA, XIAOJUAN; MA, XIUMIN; MA, ZHIXING; WANG, JING; SUN, ZHAN; YU, WENYAN; LI, FENGSEN; DING, JIANBING

    2014-01-01

    The Uygur herb, Hyssopus officinalis L., has been demonstrated to affect the levels of a number of cytokines in asthmatic mice, including interleukin-4, -6 and -17 and interferon-γ. In the present study, the effect of Hyssopus officinalis L. on airway immune regulation and airway inflammation was investigated in a mouse model of chronic asthma. A total of 32 BALB/c mice were randomly divided into four groups, which included the normal, chronic asthmatic, dexamethasone treatment and Hyssopus officinalis L.treatment groups. Mice were sensitized and challenged with ovalbumin to establish an asthma model and the ratio of eosinophils (EOS) in the bronchoalveolar lavage fluid (BALF) was determined. In addition, the levels of immunoglobulin (Ig)E and IgG were detected using an enzyme-linked immunosorbent assay. The degree of airway mucus secretion was observed using the periodic acid-Schiff stain method. The results demonstrated that the ratio of EOS in the BALF and the level of serum IgE in the chronic asthmatic and dexamethasone treatment groups increased, while the level of serum IgG decreased, when compared with the normal group. In addition, excessive secretion of airway mucus was observed in these two groups. However, the EOS ratio in the BALF and the levels of serum IgE and IgG in the Hyssopus officinalis L. treatment group were similar to the results observed in the normal group. In conclusion, Hyssopus officinalis L. not only plays an anti-inflammatory role by inhibiting the invasion of EOS and decreasing the levels of IgE, but also affects immune regulation. PMID:25289025

  9. Effect of Hyssopus officinalis L. on inhibiting airway inflammation and immune regulation in a chronic asthmatic mouse model.

    PubMed

    Ma, Xiaojuan; Ma, Xiumin; Ma, Zhixing; Wang, Jing; Sun, Zhan; Yu, Wenyan; Li, Fengsen; Ding, Jianbing

    2014-11-01

    The Uygur herb, Hyssopus officinalis L., has been demonstrated to affect the levels of a number of cytokines in asthmatic mice, including interleukin-4, -6 and -17 and interferon-γ. In the present study, the effect of Hyssopus officinalis L. on airway immune regulation and airway inflammation was investigated in a mouse model of chronic asthma. A total of 32 BALB/c mice were randomly divided into four groups, which included the normal, chronic asthmatic, dexamethasone treatment and Hyssopus officinalis L.treatment groups. Mice were sensitized and challenged with ovalbumin to establish an asthma model and the ratio of eosinophils (EOS) in the bronchoalveolar lavage fluid (BALF) was determined. In addition, the levels of immunoglobulin (Ig)E and IgG were detected using an enzyme-linked immunosorbent assay. The degree of airway mucus secretion was observed using the periodic acid-Schiff stain method. The results demonstrated that the ratio of EOS in the BALF and the level of serum IgE in the chronic asthmatic and dexamethasone treatment groups increased, while the level of serum IgG decreased, when compared with the normal group. In addition, excessive secretion of airway mucus was observed in these two groups. However, the EOS ratio in the BALF and the levels of serum IgE and IgG in the Hyssopus officinalis L. treatment group were similar to the results observed in the normal group. In conclusion, Hyssopus officinalis L. not only plays an anti-inflammatory role by inhibiting the invasion of EOS and decreasing the levels of IgE, but also affects immune regulation. PMID:25289025

  10. Acute mouse and chronic dog toxicity studies of danthron, dioctyl sodium sulfosuccinate, poloxalkol and combinations.

    PubMed

    Case, M T; Smith, J K; Nelson, R A

    Because of an apparent typographic error in a US patent, there has been some confusion as to the acute oral toxicity of danthron and danthron in combination with dioctyl sodium sulfosuccinate (DSS). Acute oral toxicity studies in mice revealed LD50 values of greater than 7 gm/kg for danthron, 2.64 gm/kg for DSS and 3.42 gm/kg for danthron/DSS mixture (1:2 ratio). These results indicate that the lethality of these compounds is in the gm/kg range and not in the mg/kg range. A one year chronic toxicity study of danthron, dioctyl sodium sulfosuccinate, poloxalkol and combinations in dogs failed to reveal any toxic effects. In particular, there was no evidence of hepatotoxicity or of any changes in the myenteric plexuses in the chronically treated dogs. PMID:90594

  11. The development and characterization of two types of chronic responses in irradiated mouse colon

    SciTech Connect

    Followill, D.S.

    1991-01-01

    The hypothesis to be tested is that there are two distinct types of chronic responses in irradiated normal tissues, each resulting from damage to different cell populations in the tissue. The first is a sequela of chronic epithelial depletion in which the tissue's integrity cannot be maintained. The other response is due to cell loss in the connective tissue and/or vascular stroma, i.e. a primary' chronic response. The purpose of this study was to test the hypothesis in the murine colon by first, establishing a model of each chronic response and then, by determining whether the responses differed in timing of expression, histology, and expression of specific collagen types. The model of late damage used was colonic obstructions/strictures induced by a single dose of 27 Gy ( consequential' response) and two equal doses of 14.75 Gy (t = 10 days) ( primary' response). Consequential' lesions appeared as early as 5 weeks after 27 Gy and were characterized by a deep mucosal ulceration and a thickened fibrotic serosa containing excessive accumulations of collagen types I and III. Both types were commingled in the scar at the base of the ulcer. Fibroblasts were synthesizing pro-collagen types I and III mRNA 10 weeks prior to measurable increases in collagen. A significant decrease in the ratio of collagen types I:III was associated with the consequential' response at 4-5 months post-irradiation. The primary' response, on the other hand, did not appear until 40 weeks after the split dose even though the total dose delivered was approximately the same as that for the consequential' response. The primary' response was characterized with an intact mucosa and a thickened fibrotic submucosa which contained excessive amounts of only collagen type I. An increased number of fibroblasts were synthesizing pro-collagen type I mRNA nearly 25 weeks before collage type I levels were increased.

  12. Metabolic profiles in serum of mouse after chronic exposure to drinking water.

    PubMed

    Zhang, Yan; Wu, Bing; Zhang, Xuxiang; Li, Aimin; Cheng, Shupei

    2011-08-01

    The toxicity of Nanjing drinking water on mouse (Mus musculus) was detected by (1)H nuclear magnetic resonance (NMR)-based metabonomic method. Three groups of mice were fed with drinking water (produced by Nanjing BHK Water Plant), 3.8 μg/L benzo(a)pyrene as contrast, and clean water as control, respectively, for 90 days. It was observed that the levels of lactate, alanine, and creatinine in the mice fed with drinking water were increased and that of valine was decreased. The mice of drinking water group were successfully separated from control. The total concentrations of polycyclic aromatic hydrocarbons (PAHs), phthalates (PAEs), and other organic pollutants in the drinking water were 0.23 μg/L, 4.57 μg/L, and 0.34 μg/L, respectively. In this study, Nanjing drinking water was found to induce distinct perturbations of metabolic profiles on mouse including disorders of glucose-alanine cycle, branched-chain amino acid and energy metabolism, and dysfunction of kidney. This study suggests that metabonomic method is feasible and sensitive to evaluate potential toxic effects of drinking water. PMID:21172972

  13. Effects of Thymus vulgaris ethanolic extract on chronic toxoplasmosis in a mouse model.

    PubMed

    Eraky, Maysa Ahmad; El-Fakahany, Amany Farouk; El-Sayed, Nagwa Mostafa; Abou-Ouf, Eman Abdel-Rahman; Yaseen, Doaa Ibrahim

    2016-07-01

    The current work was undertaken to investigate the potential effectiveness of Thymus vulgaris ethanolic extract (TVE) against Toxoplasma gondii infection in chronic experimental toxoplasmosis. To evaluate prophylactic effects, mice received 500 mg/kg TVE for 5 days before they were infected by an avirulent Me49 T. gondii strain. To investigate the therapeutic effects of the extract postinfection, daily treatment with TVE was initiated at 6 weeks postinfection and continued for 10 days. The following groups of animals were used as controls: uninfected/non-treated, infected/non-treated, and infected/treated with a combination of pyrimethamine and sulfadiazine. Brain cyst count and histopathological changes using H&E and Feulgen stains were used to evaluate the efficacy of TVE. The mean number of brain cysts was significantly decreased by 24 % in mice treated prophylactically with TVE. TVE also significantly reduced the mean number of brain cysts when administered to animals already chronically infected with T. gondii. The effect of TVE was comparable to that of treatment with a mixture of sulfadiazine and pyrimethamine (46 and 51 % reduction, respectively). Moreover, considerable amelioration of the pathological lesions in the brain and retina was observed. The results demonstrate the potential efficacy of T. vulgaris as a new natural therapeutic and prophylactic agent for use in the treatment of chronic toxoplasmosis. PMID:27098159

  14. Identification of an IFN-γ/mast cell axis in a mouse model of chronic asthma

    PubMed Central

    Yu, Mang; Eckart, Michael R.; Morgan, Alexander A.; Mukai, Kaori; Butte, Atul J.; Tsai, Mindy; Galli, Stephen J.

    2011-01-01

    Asthma is considered a Th2 cell–associated disorder. Despite this, both the Th1 cell–associated cytokine IFN-γ and airway neutrophilia have been implicated in severe asthma. To investigate the relative contributions of different immune system components to the pathogenesis of asthma, we previously developed a model that exhibits several features of severe asthma in humans, including airway neutrophilia and increased lung IFN-γ. In the present studies, we tested the hypothesis that IFN-γ regulates mast cell function in our model of chronic asthma. Engraftment of mast cell–deficient KitW-sh/W-sh mice, which develop markedly attenuated features of disease, with wild-type mast cells restored disease pathology in this model of chronic asthma. However, disease pathology was not fully restored by engraftment with either IFN-γ receptor 1–null (Ifngr1–/–) or Fcε receptor 1γ–null (Fcer1g–/–) mast cells. Additional analysis, including gene array studies, showed that mast cell expression of IFN-γR contributed to the development of many FcεRIγ-dependent and some FcεRIγ-independent features of disease in our model, including airway hyperresponsiveness, neutrophilic and eosinophilic inflammation, airway remodeling, and lung expression of several cytokines, chemokines, and markers of an alternatively activated macrophage response. These findings identify a previously unsuspected IFN-γ/mast cell axis in the pathology of chronic allergic inflammation of the airways in mice. PMID:21737883

  15. Deficiency in mouse hyaluronidase 2: a new mechanism of chronic thrombotic microangiopathy.

    PubMed

    Onclinx, Cécile; Dogne, Sophie; Jadin, Laurence; Andris, Fabienne; Grandfils, Christian; Jouret, François; Mullier, François; Flamion, Bruno

    2015-08-01

    Hyaluronan is a major component of the extracellular matrix and glycocalyx. Its main somatic degrading enzymes are hyaluronidases 1 and 2, neither of which is active in the bloodstream. We generated hyaluronidase 2-deficient mice. These animals suffer from chronic, mild anemia and thrombocytopenia, in parallel with a 10-fold increase in plasma hyaluronan concentration. In this study we explored the mechanism of these hematologic anomalies. The decreased erythrocyte and platelet counts were attributed to peripheral consumption. The erythrocyte half-life was reduced from 25 to 8 days without signs of premature aging. Hyaluronidase 2-deficient platelets were functional. Major intrinsic defects in erythrocyte membrane or stability, as well as detrimental effects of high hyaluronan levels on erythrocytes, were ruled out in vitro. Normal erythrocytes transfused into hyaluronidase 2-deficient mice were quickly destroyed but neither splenectomy nor anti-C5 administration prevented chronic hemolysis. Schistocytes were present in blood smears from hyaluronidase 2-deficient mice at a level of 1% to 6%, while virtually absent in control mice. Hyaluronidase 2-deficient mice had increased markers of endothelial damage and microvascular fibrin deposition, without renal failure, accumulation of ultra-large multimers of von Willebrand factor, deficiency of A Disintegrin And Metalloproteinase with ThromboSpondin type 1 motifs, member 13 (ADAMTS13), or hypertension. There was no sign of structural damage in hepatic or splenic sinusoids, or in any other microvessels. We conclude that hyaluronidase 2 deficiency induces chronic thrombotic microangiopathy with hemolytic anemia in mice. The link between this uncommon condition and hyaluronidase 2 remains to be explored in humans. PMID:25934767

  16. The influence of chronic nicotine treatment on proteins expressed in the mouse hippocampus and cortex.

    PubMed

    Matsuura, Kenji; Otani, Mieko; Takano, Masaoki; Kadoyama, Keiichi; Matsuyama, Shogo

    2016-06-01

    Chronic treatment with nicotine, the primary psychoactive substance in tobacco smoke, affects central nervous system functions, such as synaptic plasticity. Here, to clarify the effects of chronic nicotine treatment on the higher brain functions, proteomic analysis of the hippocampus and cortex of mice treated for 6 months with nicotine was performed using two-dimensional gel electrophoresis (2-DE) followed by mass spectrometry. There was significant change in the expression of 16 proteins and one phosphoprotein in the hippocampus (increased tubulin β-5, atp5b, MDH1, cytochrome b-c1 complex subunit 1, Hsc70, dynamin, profilin-2, 4-aminobutyrate aminotransferase, mitochondrial isoform 1 precursor, calpain small subunit 1, and vacuolar adenosine triphosphatase subunit B and decreased γ-actin, α-tubulin isotype M-α-2, putative β-actin, tubulin β-2A, NDUFA10, and G6PD) and 24 proteins and two phosphoproteins in the cortex (increased spectrin α chain, non-erythrocytic 1 isoform 1, tubulin β-5, γ-actin, creatine kinase B-type, LDH-B, secernin-1, UCH-L1, 14-3-3 γ, type II peroxiredoxin 1, PEBP-1, and unnamed protein product and decreased tubulin α-1C, α-internexin, γ-enolase, PDHE1-B, DPYL2, vacuolar adenosine triphosphatase subunit A, vacuolar adenosine triphosphatase subunit B, TCTP, NADH dehydrogenase Fe-S protein 1, protein disulfide-isomerase A3, hnRNP H2, γ-actin, atp5b, and unnamed protein product). Additionally, Western blotting validated the changes in dynamin, Hsc70, MDH1, NDUFA10, α-internexin, tubulin β-5 chain, and secernin-1. Thus, these findings indicate that chronic nicotine treatment changes the expression of proteins and phosphoproteins in the hippocampus and cortex. We propose that effect of smoking on higher brain functions could be mediated by alterations in expression levels of these proteins. PMID:26988295

  17. ENDURANCE EXERCISE PROMOTES CARDIORESPIRATORY REHABILITATION WITHOUT NEURORESTORATION IN THE CHRONIC MOUSE MODEL OF PARKINSONISM WITH SEVERE NEURODEGENERATION

    PubMed Central

    Al-Jarrah, Muhammed; Pothakos, Konstantinos; Novikova, Lesya; Smirnova, Irina V.; Kurz, Max J.; Stehno-Bittel, Lisa; Lau, Yuen-Sum

    2007-01-01

    Physical rehabilitation with endurance exercise for patients with Parkinson's disease has not been well established, although some clinical and laboratory reports suggest that exercise may produce neuroprotective effect and restore dopaminergic and motor functions. In this study, we used a chronic mouse model of Parkinsonism, which was induced by injecting male C57BL/6 mice with 10 doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (25 mg/kg) and probenecid (250 mg/kg) over five weeks. This chronic Parkinsonian model displays a severe and persistent loss of nigrostriatal neurons resulting in robust dopamine depletion and locomotor impairment in mice. Following the induction of Parkinsonism, these mice were capable to sustain an exercise training program on a motorized rodent treadmill at a speed of 18 m/min, 0° of inclination, 40 min/day, 5 days/week for 4 weeks. At the end of exercise training, we examined and compared their cardiorespiratory capacity, behavior, and neurochemical changes with that of the probenecid-treated control and sedentary Parkinsonian mice. We found that the resting heart rate after 4 weeks of exercise in the chronic Parkinsonian mice was significantly lower than the rate before exercise, whereas the resting heart rate at the beginning and 4 weeks afterwards in the control or sedentary Parkinsonian mice were unchanged. Exercised Parkinsonian mice also recovered from elevated electrocardiogram R-wave amplitude that was detected in the Parkinsonian mice without exercise for 4 weeks. The values of oxygen consumption, carbon dioxide production, and body heat generation in the exercised Parkinsonian mice before and during the Bruce maximal exercise challenge test were all significantly lower than their sedentary counterparts. Furthermore, the exercised Parkinsonian mice revealed a greater mass in the left ventricle of the heart and an increased level of citrate synthase activity in the skeletal muscles. The amphetamine-induced, dopamine

  18. Chronic liver disease is triggered by taurine transporter knockout in the mouse.

    PubMed

    Warskulat, Ulrich; Borsch, Elena; Reinehr, Roland; Heller-Stilb, Birgit; Mönnighoff, Irmhild; Buchczyk, Darius; Donner, Markus; Flögel, Ulrich; Kappert, Günther; Soboll, Sibylle; Beer, Sandra; Pfeffer, Klaus; Marschall, Hanns-Ulrich; Gabrielsen, Marcus; Amiry-Moghaddam, Mahmood; Ottersen, Ole Petter; Dienes, Hans Peter; Häussinger, Dieter

    2006-03-01

    Taurine is an abundant organic osmolyte with antioxidant and immunomodulatory properties. Its role in the pathogenesis of chronic liver disease is unknown. The liver phenotype was studied in taurine transporter knockout (taut-/-) mice. Hepatic taurine levels were ~21, 15 and 6 mumol/g liver wet weight in adult wild-type, heterozygous (taut+/-) and homozygous (taut-/-) mice, respectively. Immunoelectronmicroscopy revealed an almost complete depletion of taurine in Kupffer and sinusoidal endothelial cells, but not in parenchymal cells of (taut-/-) mice. Compared with wild-type mice, (taut-/-) and (taut+/-) mice developed moderate unspecific hepatitis and liver fibrosis with increased frequency of neoplastic lesions beyond 1 year of age. Liver disease in (taut-/-) mice was characterized by hepatocyte apoptosis, activation of the CD95 system, elevated plasma TNF-alpha levels, hepatic stellate cell and oval cell proliferation, and severe mitochondrial abnormalities in liver parenchymal cells. Mitochondrial dysfunction was suggested by a significantly lower respiratory control ratio in isolated mitochondria from (taut-/-) mice. Taut knockout had no effect on taurine-conjugated bile acids in bile; however, the relative amount of cholate-conjugates acid was decreased at the expense of 7-keto-cholate-conjugates. In conclusion, taurine deficiency due to defective taurine transport triggers chronic liver disease, which may involve mitochondrial dysfunction. PMID:16421246

  19. Chronic imaging of amyloid plaques in the live mouse brain using multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    Bacskai, Brian J.; Kajdasz, Stephen T.; Christie, R. H.; Zipfel, Warren R.; Williams, Rebecca M.; Kasischke, Karl A.; Webb, Watt W.; Hyman, B. T.

    2001-04-01

    Transgenic mice expressing the human Amyloid Precursor Protein (APP) develop amyloid plaques as they age. These plaques resemble those found in the human disease. Multiphoton laser scanning microscopy combined with a novel surgical approach was used to measure amyloid plaque dynamics chronically in the cortex of living transgenic mice. Thioflavine S (thioS) was used as a fluorescent marker of amyloid deposits. Multiphoton excitation allowed visualization of amyloid plaques up to 200 micrometers deep into the brain. The surgical site could be imaged repeatedly without overt damage to the tissue, and individual plaques within this volume could be reliably identified over periods of several days to several months. On average, plaque sizes remained constant over time, supporting a model of rapid deposition, followed by relative stability. Alternative reporters for in vivo histology include thiazine red, and FITC-labeled amyloid-(Beta) peptide. We also present examples of multi-color imaging using Hoechst dyes and FITC-labeled tomato lectin. These approaches allow us to observe cell nuclei or microglia simultaneously with amyloid-(Beta) deposits in vivo. Chronic imaging of a variety of reporters in these transgenic mice should provide insight into the dynamics of amyloid-(Beta) activity in the brain.

  20. Physical activity: benefit or weakness in metabolic adaptations in a mouse model of chronic food restriction?

    PubMed

    Méquinion, Mathieu; Caron, Emilie; Zgheib, Sara; Stievenard, Aliçia; Zizzari, Philippe; Tolle, Virginie; Cortet, Bernard; Lucas, Stéphanie; Prévot, Vincent; Chauveau, Christophe; Viltart, Odile

    2015-02-01

    In restrictive-type anorexia nervosa (AN) patients, physical activity is usually associated with food restriction, but its physiological consequences remain poorly characterized. In female mice, we evaluated the impact of voluntary physical activity with/without chronic food restriction on metabolic and endocrine parameters that might contribute to AN. In this protocol, FRW mice (i.e., food restriction with running wheel) reached a crucial point of body weight loss (especially fat mass) faster than FR mice (i.e., food restriction only). However, in contrast to FR mice, their body weight stabilized, demonstrating a protective effect of a moderate, regular physical activity. Exercise delayed meal initiation and duration. FRW mice displayed food anticipatory activity compared with FR mice, which was strongly diminished with the prolongation of the protocol. The long-term nature of the protocol enabled assessment of bone parameters similar to those observed in AN patients. Both restricted groups adapted their energy metabolism differentially in the short and long term, with less fat oxidation in FRW mice and a preferential use of glucose to compensate for the chronic energy imbalance. Finally, like restrictive AN patients, FRW mice exhibited low leptin levels, high plasma concentrations of corticosterone and ghrelin, and a disruption of the estrous cycle. In conclusion, our model suggests that physical activity has beneficial effects on the adaptation to the severe condition of food restriction despite the absence of any protective effect on lean and bone mass. PMID:25465889

  1. Chronic behavioral stress exaggerates motor deficit and neuroinflammation in the MPTP mouse model of Parkinson's disease

    PubMed Central

    Lauretti, E; Di Meco, A; Merali, S; Praticò, D

    2016-01-01

    Environmental stressor exposure is associated with a variety of age-related diseases including neurodegeneration. Although the initial events of sporadic Parkinson's disease (PD) are not known, consistent evidence supports the hypothesis that the disease results from the combined effect of genetic and environmental risk factors. Among them, behavioral stress has been shown to cause damage and neuronal loss in different areas of the brain, however, its effect on the dopaminergic system and PD pathogenesis remains to be characterized. The C57BL/6 mice underwent chronic restraint/isolation (RI) stress and were then treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), whereas the control mice were treated only with MPTP and the effect on the PD-like phenotype was evaluated. The mice that underwent RI before the administration of MPTP manifested an exaggerated motor deficit and impairment in the acquisition of motor skills, which were associated with a greater loss of neuronal tyrosine hydroxylase and astrocytes activation. By showing that RI influences the onset and progression of the PD-like phenotype, our study underlines the novel pathogenetic role that chronic behavioral stressor has in the disease process by triggering neuroinflammation and degeneration of the nigral dopaminergic system. PMID:26859816

  2. Peripheral nerve injury is accompanied by chronic transcriptome-wide changes in the mouse prefrontal cortex

    PubMed Central

    2013-01-01

    Background Peripheral nerve injury can have long-term consequences including pain-related manifestations, such as hypersensitivity to cutaneous stimuli, as well as affective and cognitive disturbances, suggesting the involvement of supraspinal mechanisms. Changes in brain structure and cortical function associated with many chronic pain conditions have been reported in the prefrontal cortex (PFC). The PFC is implicated in pain-related co-morbidities such as depression, anxiety and impaired emotional decision-making ability. We recently reported that this region is subject to significant epigenetic reprogramming following peripheral nerve injury, and normalization of pain-related structural, functional and epigenetic abnormalities in the PFC are all associated with effective pain reduction. In this study, we used the Spared Nerve Injury (SNI) model of neuropathic pain to test the hypothesis that peripheral nerve injury triggers persistent long-lasting changes in gene expression in the PFC, which alter functional gene networks, thus providing a possible explanation for chronic pain associated behaviors. Results SNI or sham surgery where performed in male CD1 mice at three months of age. Six months after injury, we performed transcriptome-wide sequencing (RNAseq), which revealed 1147 differentially regulated transcripts in the PFC in nerve-injured vs. control mice. Changes in gene expression occurred across a number of functional gene clusters encoding cardinal biological processes as revealed by Ingenuity Pathway Analysis. Significantly altered biological processes included neurological disease, skeletal muscular disorders, behavior, and psychological disorders. Several of the changes detected by RNAseq were validated by RT-QPCR and included transcripts with known roles in chronic pain and/or neuronal plasticity including the NMDA receptor (glutamate receptor, ionotropic, NMDA; grin1), neurite outgrowth (roundabout 3; robo3), gliosis (glial fibrillary acidic protein

  3. microRNA regulation of the embryonic hypoxic response in Caenorhabditis elegans

    PubMed Central

    Kagias, Konstantinos; Pocock, Roger

    2015-01-01

    Layered strategies to combat hypoxia provide flexibility in dynamic oxygen environments. Here we show that multiple miRNAs are required for hypoxic survival responses during C. elegans embryogenesis. Certain miRNAs promote while others antagonize the hypoxic survival response. We found that expression of the mir-35 family is regulated by hypoxia in a HIF-1-independent manner and loss of mir-35–41 weakens hypoxic survival mechanisms in embryos. In addition, correct regulation of the RNA binding protein, SUP-26, a mir-35 family target, is needed for survival in chronic hypoxia. The identification of the full mRNA target repertoire of these miRNAs will reveal the miRNA-regulated network of hypoxic survival mechanisms in C. elegans. PMID:26063315

  4. microRNA regulation of the embryonic hypoxic response in Caenorhabditis elegans.

    PubMed

    Kagias, Konstantinos; Pocock, Roger

    2015-01-01

    Layered strategies to combat hypoxia provide flexibility in dynamic oxygen environments. Here we show that multiple miRNAs are required for hypoxic survival responses during C. elegans embryogenesis. Certain miRNAs promote while others antagonize the hypoxic survival response. We found that expression of the mir-35 family is regulated by hypoxia in a HIF-1-independent manner and loss of mir-35-41 weakens hypoxic survival mechanisms in embryos. In addition, correct regulation of the RNA binding protein, SUP-26, a mir-35 family target, is needed for survival in chronic hypoxia. The identification of the full mRNA target repertoire of these miRNAs will reveal the miRNA-regulated network of hypoxic survival mechanisms in C. elegans. PMID:26063315

  5. Sesamol treatment reduces plasma cholesterol and triacylglycerol levels in mouse models of acute and chronic hyperlipidemia.

    PubMed

    Kumar, Nitesh; Mudgal, Jayesh; Parihar, Vipan K; Nayak, Pawan G; Kutty, N Gopalan; Rao, C Mallikarjuna

    2013-06-01

    The active constituents of Sesamum indicum, sesamin and sesamolin, have already been explored for hypolipidemic action. In this study we have explored the anti-dyslipidemic activity of another active component and metabolite of sesamolin (sesamol), by using acute models of hyperlipidemia viz., a fat tolerance test, a tyloxapol-induced hyperlipidemia model and a chronic model of hyperlipidemia viz., a high-fat diet-induced hyperlipidemia model in Swiss albino mice. Sesamol (100 and 200 mg/kg) significantly (P < 0.05) decreased triacylglycerol absorption in the fat tolerance test by showing a dose-dependent decrease in triacylglycerol levels. The hypolipidemic effect of sesamol at 200 mg/kg was equivalent to 10 mg/kg of orlistat. In the tyloxapol-induced hyperlipidemia model, Sesamol at 200 mg/kg reversed the elevated levels of cholesterol and triacylglycerol compared with the tyloxapol group at 12 and 24 h, which indicates its probable effect on cholesterol synthesis. Chronic hyperlipidemia in mice was produced by feeding a high-diet, a mixture of cholesterol (2 % w/w), cholic acid (1 % w/w) and coconut oil 30 % (v/w) with standard powdered standard animal chow (up to 100 g). Niacin (100 mg/kg) and sesamol (100 mg/kg) significantly (P < 0.05) reduced the elevated body weight compared with the high fat diet control group. Elevated levels of cholesterol and triacylglycerol were significantly (P < 0.05) reversed by the sesamol (50 and 100 mg/kg), implying that it might reduce the absorption and increase the excretion of cholesterol as well. PMID:23504268

  6. Chronic Contractile Dysfunction without Hypertrophy Does Not Provoke a Compensatory Transcriptional Response in Mouse Hearts.

    PubMed

    Matkovich, Scot J; Grubb, David R; McMullen, Julie R; Woodcock, Elizabeth A

    2016-01-01

    Diseased myocardium from humans and experimental animal models shows heightened expression and activity of a specific subtype of phospholipase C (PLC), the splice variant PLCβ1b. Previous studies from our group showed that increasing PLCβ1b expression in adult mouse hearts by viral transduction was sufficient to cause sustained contractile dysfunction of rapid onset, which was maintained indefinitely in the absence of other pathological changes in the myocardium. We hypothesized that impaired contractility alone would be sufficient to induce a compensatory transcriptional response. Unbiased, comprehensive mRNA-sequencing was performed on 6 biological replicates of rAAV6-treated blank, PLCβ1b and PLCβ1a (closely related but inactive splice variant) hearts 8 weeks after injection, when reduced contractility was manifest in PLCβ1b hearts without evidence of induced hypertrophy. Expression of PLCβ1b resulted in expression changes in only 9 genes at FDR<0.1 when compared with control and these genes appeared unrelated to contractility. Importantly, PLCβ1a caused similar mild expression changes to PLCβ1b, despite a complete lack of effect of this isoform on cardiac contractility. We conclude that contractile depression caused by PLCβ1b activation is largely independent of changes in the transcriptome, and thus that lowered contractility is not sufficient in itself to provoke measurable transcriptomic alterations. In addition, our data stress the importance of a stringent control group to filter out transcriptional changes unrelated to cardiac function. PMID:27359099

  7. Chronic Contractile Dysfunction without Hypertrophy Does Not Provoke a Compensatory Transcriptional Response in Mouse Hearts

    PubMed Central

    Grubb, David R.; McMullen, Julie R.; Woodcock, Elizabeth A.

    2016-01-01

    Diseased myocardium from humans and experimental animal models shows heightened expression and activity of a specific subtype of phospholipase C (PLC), the splice variant PLCβ1b. Previous studies from our group showed that increasing PLCβ1b expression in adult mouse hearts by viral transduction was sufficient to cause sustained contractile dysfunction of rapid onset, which was maintained indefinitely in the absence of other pathological changes in the myocardium. We hypothesized that impaired contractility alone would be sufficient to induce a compensatory transcriptional response. Unbiased, comprehensive mRNA-sequencing was performed on 6 biological replicates of rAAV6-treated blank, PLCβ1b and PLCβ1a (closely related but inactive splice variant) hearts 8 weeks after injection, when reduced contractility was manifest in PLCβ1b hearts without evidence of induced hypertrophy. Expression of PLCβ1b resulted in expression changes in only 9 genes at FDR<0.1 when compared with control and these genes appeared unrelated to contractility. Importantly, PLCβ1a caused similar mild expression changes to PLCβ1b, despite a complete lack of effect of this isoform on cardiac contractility. We conclude that contractile depression caused by PLCβ1b activation is largely independent of changes in the transcriptome, and thus that lowered contractility is not sufficient in itself to provoke measurable transcriptomic alterations. In addition, our data stress the importance of a stringent control group to filter out transcriptional changes unrelated to cardiac function. PMID:27359099

  8. Hypoxic turtles keep their cool.

    PubMed

    Madsen, Jesper G; Wang, Tobias; Madsen, Peter T

    2015-01-01

    Several species of freshwater turtles spend the winter submerged in ice-covered lakes in a state of severe metabolic depression. It has been proposed that the hibernating turtles are comatose and entirely unresponsive, which raises the question of how they detect the arrival of spring and whether they respond to sensory information during hibernation. Using evoked potential studies in cold hypoxic turtles exposed to light and vibration, we show that hibernating turtles maintain neural responsiveness to light stimuli during prolonged hypoxia, while responsiveness to vibration is lost. This reveals a state of differential neural shutdown, in different sensory systems in the cold hypoxic turtle brain. In behavioral studies we show that turtles held for 14 days in hibernation increase locomotor activity in response to light or elevated temperatures, but not to vibration or increased oxygen. We conclude that hibernating freshwater turtles are not comatose, but remain vigilant during overwintering in cold hypoxia. PMID:27227001

  9. Hypoxic turtles keep their cool

    PubMed Central

    Madsen, Jesper G; Wang, Tobias; Madsen, Peter T

    2015-01-01

    Several species of freshwater turtles spend the winter submerged in ice-covered lakes in a state of severe metabolic depression. It has been proposed that the hibernating turtles are comatose and entirely unresponsive, which raises the question of how they detect the arrival of spring and whether they respond to sensory information during hibernation. Using evoked potential studies in cold hypoxic turtles exposed to light and vibration, we show that hibernating turtles maintain neural responsiveness to light stimuli during prolonged hypoxia, while responsiveness to vibration is lost. This reveals a state of differential neural shutdown, in different sensory systems in the cold hypoxic turtle brain. In behavioral studies we show that turtles held for 14 days in hibernation increase locomotor activity in response to light or elevated temperatures, but not to vibration or increased oxygen. We conclude that hibernating freshwater turtles are not comatose, but remain vigilant during overwintering in cold hypoxia.

  10. Chronic Microdose Lithium Treatment Prevented Memory Loss and Neurohistopathological Changes in a Transgenic Mouse Model of Alzheimer's Disease.

    PubMed

    Nunes, Marielza Andrade; Schöwe, Natalia Mendes; Monteiro-Silva, Karla Cristina; Baraldi-Tornisielo, Ticiana; Souza, Suzzanna Ingryd Gonçalves; Balthazar, Janaina; Albuquerque, Marilia Silva; Caetano, Ariadiny Lima; Viel, Tania Araujo; Buck, Hudson Sousa

    2015-01-01

    The use of lithium is well established in bipolar disorders and the benefits are being demonstrated in neurodegenerative disorders. Recently, our group showed that treatment with microdose lithium stabilized the cognitive deficits observed in Alzheimer's disease (AD) patients. In order to verify the lithium microdose potential in preventing the disease development, the aim of this work was to verify the effects of chronic treatment with microdose lithium given before and after the appearance of symptoms in a mouse model of a disease similar to AD. Transgenic mice (Cg-Tg(PDGFB-APPSwInd)20Lms/2J) and their non-transgenic litter mate genetic controls were treated with lithium carbonate (0.25mg/Kg/day in drinking water) for 16 or 8 months starting at two and ten months of age, respectively [corrected]. Similar groups were treated with water. At the end of treatments, both lithium treated transgenic groups and non-transgenic mice showed no memory disruption, different from what was observed in the water treated transgenic group. Transgenic mice treated with lithium since two months of age showed decreased number of senile plaques, no neuronal loss in cortex and hippocampus and increased BDNF density in cortex, when compared to non-treated transgenic mice. It is suitable to conclude that these data support the use of microdose lithium in the prevention and treatment of Alzheimer's disease, once the neurohistopathological characteristics of the disease were modified and the memory of transgenic animals was maintained. PMID:26605788

  11. Chronic Microdose Lithium Treatment Prevented Memory Loss and Neurohistopathological Changes in a Transgenic Mouse Model of Alzheimer's Disease

    PubMed Central

    Monteiro-Silva, Karla Cristina; Baraldi-Tornisielo, Ticiana; Souza, Suzzanna Ingryd Gonçalves; Balthazar, Janaina; Albuquerque, Marilia Silva; Caetano, Ariadiny Lima; Viel, Tania Araujo; Buck, Hudson Sousa

    2015-01-01

    The use of lithium is well established in bipolar disorders and the benefits are being demonstrated in neurodegenerative disorders. Recently, our group showed that treatment with microdose lithium stabilized the cognitive deficits observed in Alzheimer’s disease (AD) patients. In order to verify the lithium microdose potential in preventing the disease development, the aim of this work was to verify the effects of chronic treatment with microdose lithium given before and after the appearance of symptoms in a mouse model of a disease similar to AD. Transgenic mice (Cg-Tg(PDGFB-APPSwInd)20Lms/2J) and their non-transgenic litter mate genetic controls were treated with lithium carbonate (1.2 mg/Kg/day in drinking water) for 16 or 8 months starting at two and ten months of age, respectively. Similar groups were treated with water. At the end of treatments, both lithium treated transgenic groups and non-transgenic mice showed no memory disruption, different from what was observed in the water treated transgenic group. Transgenic mice treated with lithium since two months of age showed decreased number of senile plaques, no neuronal loss in cortex and hippocampus and increased BDNF density in cortex, when compared to non-treated transgenic mice. It is suitable to conclude that these data support the use of microdose lithium in the prevention and treatment of Alzheimer’s disease, once the neurohistopathological characteristics of the disease were modified and the memory of transgenic animals was maintained. PMID:26605788

  12. Escin attenuates behavioral impairments, oxidative stress and inflammation in a chronic MPTP/probenecid mouse model of Parkinson's disease.

    PubMed

    Selvakumar, Govindasamy Pushpavathi; Janakiraman, Udaiyappan; Essa, Musthafa Mohamed; Justin Thenmozhi, Arokiasamy; Manivasagam, Thamilarasan

    2014-10-17

    Parkinson's disease (PD) is a progressive neurodegenerative disorder that results mainly due to the death of dopaminergic neurons in the substantia nigra (SN), and subsequently has an effect on one's motor function and coordination. The current investigation explored the neuroprotective potential of escin, a natural triterpene-saponin on chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/probenecid (MPTP/p) induced mouse model of PD. Administration of MPTP led to the depleted striatal dopamine content, impaired patterns of behavior, enhanced oxidative stress and diminished expression of tyrosine hydroxylase (TH), dopamine transporter (DAT) and vesicular monoamine transporter-2 (VMAT-2). The expressions of interleukin-6 and -10, glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor protein-1 (IBA-1), tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) in SN were also enhanced. Oral treatment of escin significantly attenuated MPTP/p induced dopaminergic markers depletion, physiological abnormalities, oxidative stress and inhibit neuroinflammatory cytokine expressions in SN. The result of our study confirmed that escin mediated its protection against experimental PD through its antioxidant and anti-inflammatory properties. PMID:24657313

  13. Chronic lymphocytic leukemia disease progression is accelerated by APRIL-TACI interaction in the TCL1 transgenic mouse model

    PubMed Central

    Lascano, Valeria; Guadagnoli, Marco; Schot, Jan G.; Luijks, Dieuwertje M.; Guikema, Jeroen E. J.; Cameron, Katherine; Hahne, Michael; Pals, Steven; Slinger, Erik; Kipps, Thomas J.; van Oers, Marinus H. J.; Eldering, Eric; Medema, Jan Paul

    2013-01-01

    Although in vitro studies pointed to the tumor necrosis factor family member APRIL (a proliferation-inducing ligand) in mediating survival of chronic lymphocytic leukemia (CLL) cells, clear evidence for a role in leukemogenesis and progression in CLL is lacking. APRIL significantly prolonged in vitro survival of CD5+B220dull leukemic cells derived from the murine Eμ-TCL1-Tg (TCL1-Tg [transgenic]) model for CLL. APRIL-TCL1 double-Tg mice showed a significantly earlier onset of leukemia and disruption of splenic architecture, and survival was significantly reduced. Interestingly, clonal evolution of CD5+B220dull cells (judged by BCR clonality) did not seem to be accelerated by APRIL; both mouse strains were oligoclonal at 4 months. Although APRIL binds different receptors, APRIL-mediated leukemic cell survival depended on tumor necrosis factor receptor superfamily member 13B (TACI) ligation. These findings indicate that APRIL has an important role in CLL and that the APRIL-TACI interaction might be a selective novel therapeutic target for human CLL. PMID:24100449

  14. Chronic Pharmacological mGluR5 Inhibition Prevents Cognitive Impairment and Reduces Pathogenesis in an Alzheimer Disease Mouse Model.

    PubMed

    Hamilton, Alison; Vasefi, Maryam; Vander Tuin, Cheryl; McQuaid, Robyn J; Anisman, Hymie; Ferguson, Stephen S G

    2016-05-31

    Beta-amyloid (Aβ) oligomers contribute to the pathophysiology of Alzheimer disease (AD), and metabotropic glutamate receptor 5 (mGluR5) has been shown to act as a receptor for both Aβ oligomers and cellular prion proteins. Furthermore, the genetic deletion of mGluR5 in an APPswe/PS1ΔE9 mouse model of AD improves cognitive function and reduces Aβ plaques and Aβ oligomer concentrations. Here, we show that chronic administration of the orally bioavailable mGluR5-selective negative allosteric modulator CTEP, which is similar in structure, potency, and selectivity to Basimglurant (RO4917523), which is currently in phase II clinical development for major depressive disorder and fragile X syndrome, reverses cognitive decline in APPswe/PS1ΔE9 mice and reduces Aβ plaque deposition and soluble Aβ oligomer concentrations in both APPswe/PS1ΔE9 and 3xTg-AD male mice. These findings suggest that CTEP or its analogue Basimglutant might potentially be an effective therapeutic for the treatment of AD patients. PMID:27210751

  15. Metabolomic identification of biochemical changes induced by fluoxetine and imipramine in a chronic mild stress mouse model of depression

    NASA Astrophysics Data System (ADS)

    Zhao, Jing; Jung, Yang-Hee; Jang, Choon-Gon; Chun, Kwang-Hoon; Kwon, Sung Won; Lee, Jeongmi

    2015-03-01

    Metabolomics was applied to a C57BL/6N mouse model of chronic unpredictable mild stress (CMS). Such mice were treated with two antidepressants from different categories: fluoxetine and imipramine. Metabolic profiling of the hippocampus was performed using gas chromatography-mass spectrometry analysis on samples prepared under optimized conditions, followed by principal component analysis, partial least squares-discriminant analysis, and pair-wise orthogonal projections to latent structures discriminant analyses. Body weight measurement and behavior tests including an open field test and the forced swimming test were completed with the mice as a measure of the phenotypes of depression and antidepressive effects. As a result, 23 metabolites that had been differentially expressed among the control, CMS, and antidepressant-treated groups demonstrated that amino acid metabolism, energy metabolism, adenosine receptors, and neurotransmitters are commonly perturbed by drug treatment. Potential predictive markers for treatment effect were identified: myo-inositol for fluoxetine and lysine and oleic acid for imipramine. Collectively, the current study provides insights into the molecular mechanisms of the antidepressant effects of two widely used medications.

  16. Metabolomic identification of biochemical changes induced by fluoxetine and imipramine in a chronic mild stress mouse model of depression

    PubMed Central

    Zhao, Jing; Jung, Yang-Hee; Jang, Choon-Gon; Chun, Kwang-Hoon; Kwon, Sung Won; Lee, Jeongmi

    2015-01-01

    Metabolomics was applied to a C57BL/6N mouse model of chronic unpredictable mild stress (CMS). Such mice were treated with two antidepressants from different categories: fluoxetine and imipramine. Metabolic profiling of the hippocampus was performed using gas chromatography-mass spectrometry analysis on samples prepared under optimized conditions, followed by principal component analysis, partial least squares-discriminant analysis, and pair-wise orthogonal projections to latent structures discriminant analyses. Body weight measurement and behavior tests including an open field test and the forced swimming test were completed with the mice as a measure of the phenotypes of depression and antidepressive effects. As a result, 23 metabolites that had been differentially expressed among the control, CMS, and antidepressant-treated groups demonstrated that amino acid metabolism, energy metabolism, adenosine receptors, and neurotransmitters are commonly perturbed by drug treatment. Potential predictive markers for treatment effect were identified: myo-inositol for fluoxetine and lysine and oleic acid for imipramine. Collectively, the current study provides insights into the molecular mechanisms of the antidepressant effects of two widely used medications. PMID:25749400

  17. Chronic behavioral testing after focal ischemia in the mouse: functional recovery and the effects of gender.

    PubMed

    Li, Xiaoling; Blizzard, Kathleen K; Zeng, Zhiyuan; DeVries, A Courtney; Hurn, Patricia D; McCullough, Louise D

    2004-05-01

    Several useful behavioral tests exist for measuring behavioral recovery after ischemia in higher-order animals and rats. With the increasing use of mice in focal stroke research, simple, reliable, and reproducible behavioral testing has become a priority. As neuroprotective agents are tested, long-term outcome must be assessed, especially in studies focused on neuronal plasticity and regeneration after ischemia. Our laboratory and others have previously shown that estrogen (E2) is neuroprotective in rodent stroke paradigms. We examined a battery of behavioral tests in male and female mice subjected to 90 min of middle cerebral artery occlusion (MCAO) to determine the most sensitive tests for detecting sensorimotor dysfunction after stroke, and to determine the functional significance of E2-mediated neuroprotection. Only two tests, the corner test and the cylinder test, were able to differentiate between groups (sham and stroke) after several days of repeated testing. The cylinder test was sensitive to the neuroprotective/neurorestorative effects of E2, but 2 weeks after stroke, the cylinder test was unable to distinguish between sham and stroke animals treated with E2. In contrast, the corner test was able to differentiate stroke and sham animals even 6 weeks after stroke, but did not distinguish animals treated with E2 vs. vehicle. These tests provide a simple, rapid, reliable assessment of sensorimotor dysfunction in the mouse after focal ischemia. Hormonal status influences speed of recovery on cylinder testing in animals of both genders. This suggests that a short battery of tests including the neurological score, cylinder, and corner test may be adequate to rapidly and repeatedly assess sensorimotor dysfunction in mice of both genders. PMID:15081592

  18. Neurovascular changes in acute, sub-acute and chronic mouse models of Parkinson's disease.

    PubMed

    Sarkar, Sumit; Raymick, James; Mann, Dushyant; Bowyer, John F; Hanig, Joseph P; Schmued, Larry C; Paule, Merle G; Chigurupati, Srinivasulu

    2014-02-01

    Although selective neurodegeneration of nigro-striatal dopaminergic neurons is widely accepted as a cause of Parkinson's disease (PD), the role of vascular components in the brain in PD pathology is not well understood. However, the neurodegeneration seen in PD is known to be associated with neuroinflammatory-like changes that can affect or be associated with brain vascular function. Thus, dysfunction of the capillary endothelial cell component of neurovascular units present in the brain may contribute to the damage to dopaminergic neurons that occurs in PD. An animal model of PD employing acute, sub-acute and chronic exposures of mice to methyl-phenyl-tetrahydropyridine (MPTP) was used to determine the extent to which brain vasculature may be damaged in PD. Fluoro-Turquoise gelatin labeling of microvessels and endothelial cells was used to determine the extent of vascular damage produced by MPTP. In addition, tyrosine hydroxylase (TH) and NeuN were employed to detect and quantify dopaminergic neuron damage in the striatum (CPu) and substantia nigra (SNc). Gliosis was evaluated through GFAP immunohistochemistry. MPTP treatment drastically reduced TH immunoreactive neurons in the SNc (20.68 ± 2.83 in acute; 22.98 ± 2.14 in sub-acute; 10.20 ± 2.24 in chronic vs 34.88 ± 2.91 in controls; p<0.001). Similarly, TH immunoreactive terminals were dramatically reduced in the CPu of MPTP treated mice. Additionally, all three MPTP exposures resulted in a decrease in the intensity, length, and number of vessels in both CPu and SNc. Degenerative vascular changes such as endothelial cell 'clusters' were also observed after MPTP suggesting that vasculature damage may be modifying the availability of nutrients and exposing blood cells and/or toxic substances to neurons and glia. In summary, vascular damage and degeneration could be an additional exacerbating factor in the progression of PD, and therapeutics that protect and insure vascular integrity may be novel treatments for

  19. Anti-fatigue effect of Myelophil in a chronic forced exercise mouse model.

    PubMed

    Lee, Jin-Seok; Kim, Hyeong-Geug; Han, Jong-Min; Kim, Young-Ae; Son, Chang-Gue

    2015-10-01

    This study was performed to evaluate the anti-fatigue effects of Myelophil. ICR male mice (10 weeks old) were forced to run for 1 hour, 5 days/week for 4 weeks. Each running session was followed by administration of distilled water, Myelophil (50 or 100 mg/kg), or ascorbic acid (100 mg/kg) 1h later. Equal proportions of Astragali Radix and Salviae Miltiorrhizae Radix were extracted using 30% ethanol, and formulated into Myelophil. To evaluate the anti-fatigue effects of Myelophil, exercise tolerance and forced swimming tests were conducted. Underlying mechanisms, including oxidant-antioxidant balance, inflammatory response, and energy metabolism, were investigated by analyzing skeletal muscle tissues and/or sera. Myelophil significantly increased exercise ability and latency times, and decreased the number of electric shocks and immobility time on exercise tolerance and forced swimming tests compared with control group. Myelophil also significantly ameliorated fatigue-induced alterations in oxidative stress biomarkers, antioxidant enzymes and antioxidant capacity, as measured by multiple assays, including enzyme activity assays and western blotting, as well as alterations in pro- and anti-inflammatory cytokines in skeletal muscle. Furthermore, Myelophil normalized alterations in energy metabolic markers in sera. These findings suggest that Myelophil reduces the effects of chronic fatigue, likely by attenuating oxidative and inflammatory responses and normalizing energy metabolism. Consequently, this study provides evidence for the clinical relevance of Myelophil. PMID:26142828

  20. Persistent at-level thermal hyperalgesia and tactile allodynia accompany chronic neuronal and astrocyte activation in superficial dorsal horn following mouse cervical contusion spinal cord injury.

    PubMed

    Watson, Jaime L; Hala, Tamara J; Putatunda, Rajarshi; Sannie, Daniel; Lepore, Angelo C

    2014-01-01

    In humans, sensory abnormalities, including neuropathic pain, often result from traumatic spinal cord injury (SCI). SCI can induce cellular changes in the CNS, termed central sensitization, that alter excitability of spinal cord neurons, including those in the dorsal horn involved in pain transmission. Persistently elevated levels of neuronal activity, glial activation, and glutamatergic transmission are thought to contribute to the hyperexcitability of these dorsal horn neurons, which can lead to maladaptive circuitry, aberrant pain processing and, ultimately, chronic neuropathic pain. Here we present a mouse model of SCI-induced neuropathic pain that exhibits a persistent pain phenotype accompanied by chronic neuronal hyperexcitability and glial activation in the spinal cord dorsal horn. We generated a unilateral cervical contusion injury at the C5 or C6 level of the adult mouse spinal cord. Following injury, an increase in the number of neurons expressing ΔFosB (a marker of chronic neuronal activation), persistent astrocyte activation and proliferation (as measured by GFAP and Ki67 expression), and a decrease in the expression of the astrocyte glutamate transporter GLT1 are observed in the ipsilateral superficial dorsal horn of cervical spinal cord. These changes have previously been associated with neuronal hyperexcitability and may contribute to altered pain transmission and chronic neuropathic pain. In our model, they are accompanied by robust at-level hyperaglesia in the ipsilateral forepaw and allodynia in both forepaws that are evident within two weeks following injury and persist for at least six weeks. Furthermore, the pain phenotype occurs in the absence of alterations in forelimb grip strength, suggesting that it represents sensory and not motor abnormalities. Given the importance of transgenic mouse technology, this clinically-relevant model provides a resource that can be used to study the molecular mechanisms contributing to neuropathic pain

  1. Antidepressant-like effects of oleoylethanolamide in a mouse model of chronic unpredictable mild stress.

    PubMed

    Jin, Peng; Yu, Hai-Ling; Tian-Lan; Zhang, Feng; Quan, Zhe-Shan

    2015-06-01

    Oleoylethanolamide (OEA) is an endocannabinoid analog that belongs to a family of endogenous acylethanolamides. Increasing evidence suggests that OEA may act as an endogenous neuroprotective factor and participate in the control of mental disorder-related behaviors. In this study, we examined whether OEA is effective against depression and investigated the role of circulating endogenous acylethanolamides during stress. Mice were subjected to 28days of chronic unpredictable mild stress (CUMS), and during the last 21days, treated with oral OEA (1.5-6mg/kg) or 6mg/kg fluoxetine. Sucrose preference and open field test activity were used to evaluate depression-like behaviors during CUMS and after OEA treatment. Weights of the prefrontal cortex and hippocampus were determined, and the adrenal index was measured. Furthermore, changes in serum adrenocorticotropic hormone (ACTH), corticosterone (CORT) and total antioxidant capacity (T-AOC), brain-derived neurotrophic factor (BDNF), and lipid peroxidation product malondialdehyde (MDA) levels, and superoxide dismutase (SOD) activities in the hippocampus and prefrontal cortex were detected. Our findings indicate that OEA normalized sucrose preferences, locomotion distances, rearing frequencies, prefrontal cortex and hippocampal atrophy, and adrenal indices. In addition, OEA reversed the abnormalities of BDNF and MDA levels and SOD activities in the hippocampus and prefrontal cortex, as well as changes in serum levels of ACTH, CORT, and T-AOC. The antidepressant effects of OEA may be related to the regulation of BDNF levels in the hippocampus and prefrontal cortex, antioxidant defenses, and normalizing hyperactivity in the hypothalamic-pituitary-adrenal axis (HPA). PMID:25864425

  2. Natural killer T cells are dispensable in the development of allergen-induced airway hyperresponsiveness, inflammation and remodelling in a mouse model of chronic asthma.

    PubMed

    Koh, Y-I; Shim, J-U; Lee, J-H; Chung, I-J; Min, J-J; Rhee, J H; Lee, H C; Chung, D H; Wi, J-O

    2010-07-01

    Natural killer T (NK T) cells have been shown to play an essential role in the development of allergen-induced airway hyperresponsiveness (AHR) and/or airway inflammation in mouse models of acute asthma. Recently, NK T cells have been reported to be required for the development of AHR in a virus induced chronic asthma model. We investigated whether NK T cells were required for the development of allergen-induced AHR, airway inflammation and airway remodelling in a mouse model of chronic asthma. CD1d-/- mice that lack NK T cells were used for the experiments. In the chronic model, AHR, eosinophilic inflammation, remodelling characteristics including mucus metaplasia, subepithelial fibrosis and increased mass of the airway smooth muscle, T helper type 2 (Th2) immune response and immunoglobulin (Ig)E production were equally increased in both CD1d-/- mice and wild-type mice. However, in the acute model, AHR, eosinophilic inflammation, Th2 immune response and IgE production were significantly decreased in the CD1d-/- mice compared to wild-type. CD1d-dependent NK T cells may not be required for the development of allergen-induced AHR, eosinophilic airway inflammation and airway remodelling in chronic asthma model, although they play a role in the development of AHR and eosinophilic inflammation in acute asthma model. PMID:20456411

  3. Wnt-Responsive Cancer Stem Cells Are Located Close to Distorted Blood Vessels and Not in Hypoxic Regions in a p53-Null Mouse Model of Human Breast Cancer

    PubMed Central

    Landua, John D.; Bu, Wen; Wei, Wei; Li, Fuhai; Wong, Stephen T.C.; Dickinson, Mary E.; Rosen, Jeffrey M.; Lewis, Michael T.

    2014-01-01

    Cancer stem cells (CSCs, or tumor-initiating cells) may be responsible for tumor formation in many types of cancer, including breast cancer. Using high-resolution imaging techniques, we analyzed the relationship between a Wnt-responsive, CSC-enriched population and the tumor vasculature using p53-null mouse mammary tumors transduced with a lentiviral Wnt signaling reporter. Consistent with their localization in the normal mammary gland, Wnt-responsive cells in tumors were enriched in the basal/myoepithelial population and generally located in close proximity to blood vessels. The Wnt-responsive CSCs did not colocalize with the hypoxia-inducible factor 1α-positive cells in these p53-null basal-like tumors. Average vessel diameter and vessel tortuosity were increased in p53-null mouse tumors, as well as in a human tumor xenograft as compared with the normal mammary gland. The combined strategy of monitoring the fluorescently labeled CSCs and vasculature using high-resolution imaging techniques provides a unique opportunity to study the CSC and its surrounding vasculature. PMID:24797826

  4. Wnt-responsive cancer stem cells are located close to distorted blood vessels and not in hypoxic regions in a p53-null mouse model of human breast cancer.

    PubMed

    Vadakkan, Tegy J; Landua, John D; Bu, Wen; Wei, Wei; Li, Fuhai; Wong, Stephen T C; Dickinson, Mary E; Rosen, Jeffrey M; Lewis, Michael T; Zhang, Mei

    2014-07-01

    Cancer stem cells (CSCs, or tumor-initiating cells) may be responsible for tumor formation in many types of cancer, including breast cancer. Using high-resolution imaging techniques, we analyzed the relationship between a Wnt-responsive, CSC-enriched population and the tumor vasculature using p53-null mouse mammary tumors transduced with a lentiviral Wnt signaling reporter. Consistent with their localization in the normal mammary gland, Wnt-responsive cells in tumors were enriched in the basal/myoepithelial population and generally located in close proximity to blood vessels. The Wnt-responsive CSCs did not colocalize with the hypoxia-inducible factor 1α-positive cells in these p53-null basal-like tumors. Average vessel diameter and vessel tortuosity were increased in p53-null mouse tumors, as well as in a human tumor xenograft as compared with the normal mammary gland. The combined strategy of monitoring the fluorescently labeled CSCs and vasculature using high-resolution imaging techniques provides a unique opportunity to study the CSC and its surrounding vasculature. PMID:24797826

  5. Chronic alterations in growth hormone/insulin-like growth factor-I signaling lead to changes in mouse tendon structure.

    PubMed

    Nielsen, R H; Clausen, N M; Schjerling, P; Larsen, J O; Martinussen, T; List, E O; Kopchick, J J; Kjaer, M; Heinemeier, K M

    2014-02-01

    The growth hormone/insulin-like growth factor-I (GH/IGF-I) axis is an important stimulator of collagen synthesis in connective tissue, but the effect of chronically altered GH/IGF-I levels on connective tissue of the muscle-tendon unit is not known. We studied three groups of mice; 1) giant transgenic mice that expressed bovine GH (bGH) and had high circulating levels of GH and IGF-I, 2) dwarf mice with a disrupted GH receptor gene (GHR-/-) leading to GH resistance and low circulating IGF-I, and 3) a wild-type control group (CTRL). We measured the ultra-structure, collagen content and mRNA expression (targets: GAPDH, RPLP0, IGF-IEa, IGF-IR, COL1A1, COL3A1, TGF-β1, TGF-β2, TGF-β3, versican, scleraxis, tenascin C, fibronectin, fibromodulin, decorin) in the Achilles tendon, and the mRNA expression was also measured in calf muscle (same targets as tendon plus IGF-IEb, IGF-IEc). We found that GHR-/- mice had significantly lower collagen fibril volume fraction in Achilles tendon, as well as decreased mRNA expression of IGF-I isoforms and collagen types I and III in muscle compared to CTRL. In contrast, the mRNA expression of IGF-I isoforms and collagens in bGH mice was generally high in both tendon and muscle compared to CTRL. Mean collagen fibril diameter was significantly decreased with both high and low GH/IGF-I signaling, but the GHR-/- mouse tendons were most severely affected with a total loss of the normal bimodal diameter distribution. In conclusion, chronic manipulation of the GH/IGF-I axis influenced both morphology and mRNA levels of selected genes in the muscle-tendon unit of mice. Whereas only moderate structural changes were observed with up-regulation of GH/IGF-I axis, disruption of the GH receptor had pronounced effects upon tendon ultra-structure. PMID:24080228

  6. Development of doxorubicin-induced chronic cardiotoxicity in the B6C3F{sub 1} mouse model

    SciTech Connect

    Desai, Varsha G.; Herman, Eugene H.; Moland, Carrie L.; Branham, William S.; Lewis, Sherry M.; Davis, Kelly J.; George, Nysia I.; Lee, Taewon; Kerr, Susan; Fuscoe, James C.

    2013-01-01

    Serum levels of cardiac troponins serve as biomarkers of myocardial injury. However, troponins are released into the serum only after damage to cardiac tissue has occurred. Here, we report development of a mouse model of doxorubicin (DOX)-induced chronic cardiotoxicity to aid in the identification of predictive biomarkers of early events of cardiac tissue injury. Male B6C3F{sub 1} mice were administered intravenous DOX at 3 mg/kg body weight, or an equivalent volume of saline, once a week for 4, 6, 8, 10, 12, and 14 weeks, resulting in cumulative DOX doses of 12, 18, 24, 30, 36, and 42 mg/kg, respectively. Mice were sacrificed a week following the last dose. A significant reduction in body weight gain was observed in mice following exposure to a weekly DOX dose for 1 week and longer compared to saline-treated controls. DOX treatment also resulted in declines in red blood cell count, hemoglobin level, and hematocrit compared to saline-treated controls after the 2nd weekly dose until the 8th and 9th doses, followed by a modest recovery. All DOX-treated mice had significant elevations in cardiac troponin T concentrations in plasma compared to saline-treated controls, indicating cardiac tissue injury. Also, a dose-related increase in the severity of cardiac lesions was seen in mice exposed to 24 mg/kg DOX and higher cumulative doses. Mice treated with cumulative DOX doses of 30 mg/kg and higher showed a significant decline in heart rate, suggesting drug-induced cardiac dysfunction. Altogether, these findings demonstrate the development of DOX-induced chronic cardiotoxicity in B6C3F{sub 1} mice. -- Highlights: ► 24 mg/kg was a cumulative cardiotoxic dose of doxorubicin in male B6C3F{sub 1} mice. ► Doxorubicin-induced hematological toxicity was in association with splenomegaly. ► Doxorubicin induced severe testicular toxicity in B6C3F{sub 1} male mice.

  7. Bruton’s tyrosine kinase mediated signaling enhances leukemogenesis in a mouse model for chronic lymphocytic leukemia

    PubMed Central

    Kil, Laurens P; de Bruijn, Marjolein JW; van Hulst, Jennifer AC; Langerak, Anton W; Yuvaraj, Saravanan; Hendriks, Rudi W

    2013-01-01

    In chronic lymphocytic leukemia (CLL) signals from the B cell receptor (BCR) play a major role in disease development and progression. In this light, new therapies that specifically target signaling molecules downstream of the BCR continue to be developed. While first studies on the selective small molecule inhibitor of Bruton’s tyrosine kinase (Btk), Ibrutinib (PCI-32765), demonstrated that Btk inhibition sensitizes CLL cells to apoptosis and alters their migratory behavior, these studies however did not address whether Btk-mediated signaling is involved in the process of CLL leukemogenesis. To investigate the requirement of Btk signaling for CLL development, we modulated Btk expression in the IgH.ETμ CLL mouse model, which is based on sporadic expression of the simian oncovirus SV40 T-antigen in mature B cells. To this end, we crossed IgH.ETμ mice on a Btk-deficient background or introduced a human Btk transgene (CD19-hBtk). Here we show that Btk deficiency fully abrogates CLL formation in IgH.ETμ mice, and that leukemias formed in Btk haplo-insufficient mice selectively expressed the wild-type Btk allele on their active X chromosome. Conversely, Btk overexpression accelerated CLL onset, increased mortality, and was associated with selection of non-stereotypical BCRs into CLL clones. Taken together, these data show that Btk expression represents an absolute prerequisite for CLL development and that Btk mediated signaling enhances leukemogenesis in mice. We therefore conclude that in CLL Btk expression levels set the threshold for malignant transformation. PMID:23359016

  8. Dendritic Spine Loss and Chronic White Matter Inflammation in a Mouse Model of Highly Repetitive Head Trauma.

    PubMed

    Winston, Charisse N; Noël, Anastasia; Neustadtl, Aidan; Parsadanian, Maia; Barton, David J; Chellappa, Deepa; Wilkins, Tiffany E; Alikhani, Andrew D; Zapple, David N; Villapol, Sonia; Planel, Emmanuel; Burns, Mark P

    2016-03-01

    Mild traumatic brain injury (mTBI) is an emerging risk for chronic behavioral, cognitive, and neurodegenerative conditions. Athletes absorb several hundred mTBIs each year; however, rodent models of repeat mTBI (rmTBI) are often limited to impacts in the single digits. Herein, we describe the effects of 30 rmTBIs, examining structural and pathological changes in mice up to 365 days after injury. We found that single mTBI causes a brief loss of consciousness and a transient reduction in dendritic spines, reflecting a loss of excitatory synapses. Single mTBI does not cause axonal injury, neuroinflammation, or cell death in the gray or white matter. Thirty rmTBIs with a 1-day interval between each mTBI do not cause dendritic spine loss; however, when the interinjury interval is increased to 7 days, dendritic spine loss is reinstated. Thirty rmTBIs cause white matter pathology characterized by positive silver and Fluoro-Jade B staining, and microglial proliferation and activation. This pathology continues to develop through 60 days, and is still apparent at 365 days, after injury. However, rmTBIs did not increase β-amyloid levels or tau phosphorylation in the 3xTg-AD mouse model of Alzheimer disease. Our data reveal that single mTBI causes a transient loss of synapses, but that rmTBIs habituate to repetitive injury within a short time period. rmTBI causes the development of progressive white matter pathology that continues for months after the final impact. PMID:26857506

  9. The Spectrum of Neurobehavioral Sequelae after Repetitive Mild Traumatic Brain Injury: A Novel Mouse Model of Chronic Traumatic Encephalopathy

    PubMed Central

    Plog, Benjamin A.; Dayawansa, Samantha; Chen, Michael; Dashnaw, Matthew L.; Czerniecka, Katarzyna; Walker, Corey T.; Viterise, Tyler; Hyrien, Ollivier; Iliff, Jeffrey J.; Deane, Rashid; Nedergaard, Maiken; Huang, Jason H.

    2014-01-01

    Abstract There has been an increased focus on the neurological sequelae of repetitive mild traumatic brain injury (TBI), particularly neurodegenerative syndromes, such as chronic traumatic encephalopathy (CTE); however, no animal model exists that captures the behavioral spectrum of this phenomenon. We sought to develop an animal model of CTE. Our novel model is a modification and fusion of two of the most popular models of TBI and allows for controlled closed-head impacts to unanesthetized mice. Two-hundred and eighty 12-week-old mice were divided into control, single mild TBI (mTBI), and repetitive mTBI groups. Repetitive mTBI mice received six concussive impacts daily for 7 days. Behavior was assessed at various time points. Neurological Severity Score (NSS) was computed and vestibulomotor function tested with the wire grip test (WGT). Cognitive function was assessed with the Morris water maze (MWM), anxiety/risk-taking behavior with the elevated plus maze, and depression-like behavior with the forced swim/tail suspension tests. Sleep electroencephalogram/electromyography studies were performed at 1 month. NSS was elevated, compared to controls, in both TBI groups and improved over time. Repetitive mTBI mice demonstrated transient vestibulomotor deficits on WGT. Repetitive mTBI mice also demonstrated deficits in MWM testing. Both mTBI groups demonstrated increased anxiety at 2 weeks, but repetitive mTBI mice developed increased risk-taking behaviors at 1 month that persist at 6 months. Repetitive mTBI mice exhibit depression-like behavior at 1 month. Both groups demonstrate sleep disturbances. We describe the neurological sequelae of repetitive mTBI in a novel mouse model, which resemble several of the neuropsychiatric behaviors observed clinically in patients sustaining repetitive mild head injury. PMID:24766454

  10. Effect of chronic coffee consumption on weight gain and glycaemia in a mouse model of obesity and type 2 diabetes

    PubMed Central

    Rustenbeck, I; Lier-Glaubitz, V; Willenborg, M; Eggert, F; Engelhardt, U; Jörns, A

    2014-01-01

    Objective: Epidemiological evidence shows that chronic coffee consumption in humans is correlated with a lower incidence of type 2 diabetes mellitus. For the experimental exploration of the underlying mechanisms, this effect needs to be replicated in an animal model of type 2 diabetes with a short lifespan. Design: Male C57BL/6 mice consumed regular coffee or water ad libitum and the development of obesity and diabetes caused by high-fat diet (55% lipids, HFD) was observed from week 10 on for 35 weeks in comparison with mice feeding on a defined normal diet (9% lipids, ND). Results: The massive weight gain in HFD mice was dose-dependently retarded (P=0.034), the moderate weight gain in ND mice was abolished (P<0.001) by coffee consumption, probably because of a lower feeding efficiency. The consumption of fluid (water or coffee) was significantly diminished by HFD (P<0.001), resulting in a higher coffee exposure of ND mice. On week 21 intraperitoneal glucose tolerance tests (IPGTT) showed a dose-dependent faster decline of elevated glucose levels in coffee-consuming HFD mice (P=0.016), but not in ND mice. Remarkably, a spontaneous decrease in non-fasting glycaemia occurred after week 21 in all treatment groups (P<0.001). On week 39 the IPGTT showed diminished peak of glucose levels in coffee-consuming HFD mice (P<0.05). HFD mice were hyperinsulinaemic and had significantly (P<0.001) enlarged islets. Coffee consumption did not affect islet size or parameters of beta-cell apoptosis, proliferation and insulin granule content. Conclusion: Coffee consumption retarded weight gain and improved glucose tolerance in a mouse model of type 2 diabetes and corresponding controls. This gives rise to the expectation that further insight into the mechanism of the diabetes-preventive effect of coffee consumption in humans may be gained by this approach. PMID:24979152

  11. Puerarin Induces Mitochondria-Dependent Apoptosis in Hypoxic Human Pulmonary Arterial Smooth Muscle Cells

    PubMed Central

    Chen, Chan; Chen, Chun; Wang, Zhiyi; Wang, Liangxing; Yang, Lehe; Ding, Minjiao; Ding, Cheng; Sun, Yu; Lin, Quan; Huang, Xiaoying; Du, Xiaohong; Zhao, Xiaowei; Wang, Chuangyi

    2012-01-01

    Background Pulmonary vascular medial hypertrophy in hypoxic pulmonary arterial hypertension (PAH) is caused in part by decreased apoptosis in pulmonary artery smooth muscle cells (PASMCs). Puerarin, an isoflavone purified from the Chinese medicinal herb kudzu, ameliorates chronic hypoxic PAH in animal models. Here we investigated the effects of puerarin on apoptosis of hypoxic human PASMCs (HPASMCs), and to determine the possible underlying mechanisms. Methodology/Principal Findings HPASMCs were cultured for 24 h in normoxia or hypoxia (5% O2) conditions with and without puerarin. Cell number and viability were determined with a hemacytometer or a cell counting kit. Apoptosis was detected with a TUNEL test, rhodamine-123 (R-123) fluorescence, a colorimetric assay, western blots, immunohistochemical staining and RT-PCR. Hypoxia inhibited mitochondria-dependent apoptosis and promoted HPASMC growth. In contrast, after puerarin (50 µM or more) intervention, cell growth was inhibited and apoptosis was observed. Puerarin-induced apoptosis in hypoxic HPASMCs was accompanied by reduced mitochondrial membrane potential, cytochrome c release from the mitochondria, caspase-9 activation, and Bcl-2 down-regulation with concurrent Bax up-regulation. Conclusions/Significance Puerarin promoted apoptosis in hypoxic HPASMCs by acting on the mitochondria-dependent pathway. These results suggest a new mechanism of puerarin relevant to the management of clinical hypoxic pulmonary hypertension. PMID:22457823

  12. Hypoxic Adaptation during Development: Relation to Pattern of Neurological Presentation and Cognitive Disability

    ERIC Educational Resources Information Center

    Kirkham, Fenella J.; Datta, Avijit K.

    2006-01-01

    Children with acute hypoxic-ischaemic events (e.g. stroke) and chronic neurological conditions associated with hypoxia frequently present to paediatric neurologists. Failure to adapt to hypoxia may be a common pathophysiological pathway linking a number of other conditions of childhood with cognitive deficit. There is evidence that congenital…

  13. Avian embryos in hypoxic environments.

    PubMed

    León-Velarde, F; Monge-C, C

    2004-08-12

    Avian embryos at high altitude do not benefit of the maternal protection against hypoxia as in mammals. Nevertheless, avian embryos are known to hatch successfully at altitudes between 4,000 and 6,500 m. This review considers some of the processes that bring about the outstanding modifications in the pressure differences between the environment and mitochondria of avian embryos in hypoxic environments. Among species, some maintain normal levels of oxygen consumption ( VO2) have a high oxygen carrying capacity, lower the air cell-arterial pressure difference ( PAO2 - PaO2 ) with a constant pH. Other species decrease VO2, increase only slightly the oxygen carrying capacity, have a higher PAO2 - PaO2 difference than sea-level embryos and lower the PCO2 and pH. High altitude embryos, and those exposed to hypoxia have an accelerated decline of erythrocyte ATP levels during development and an earlier stimulation of 2,3-BPG synthesis. A higher Bohr effect may ensure high tissue PO2 in the presence of the high-affinity hemoglobin. Independently of the strategy used, they serve together to promote suitable rates of development and successful hatching of high altitude birds in hypoxic environments. PMID:15288603

  14. Chronic Anatabine Treatment Reduces Alzheimer’s Disease (AD)-Like Pathology and Improves Socio-Behavioral Deficits in a Transgenic Mouse Model of AD

    PubMed Central

    Verma, Megha; Beaulieu-Abdelahad, David; Ait-Ghezala, Ghania; Li, Rena; Crawford, Fiona; Mullan, Michael; Paris, Daniel

    2015-01-01

    Anatabine is a minor tobacco alkaloid, which is also found in plants of the Solanaceae family and displays a chemical structure similarity with nicotine. We have shown previously that anatabine displays some anti-inflammatory properties and reduces microgliosis and tau phosphorylation in a pure mouse model of tauopathy. We therefore investigated the effects of a chronic oral treatment with anatabine in a transgenic mouse model (Tg PS1/APPswe) of Alzheimer’s disease (AD) which displays pathological Aβ deposits, neuroinflammation and behavioral deficits. In the elevated plus maze, Tg PS1/APPswe mice exhibited hyperactivity and disinhibition compared to wild-type mice. Six and a half months of chronic oral anatabine treatment, suppressed hyperactivity and disinhibition in Tg PS1/APPswe mice compared to Tg PS1/APPswe receiving regular drinking water. Tg PS1/APPswe mice also elicited profound social interaction and social memory deficits, which were both alleviated by the anatabine treatment. We found that anatabine reduces the activation of STAT3 and NFκB in the vicinity of Aβ deposits in Tg PS1/APPswe mice resulting in a reduction of the expression of some of their target genes including Bace1, iNOS and Cox-2. In addition, a significant reduction in microgliosis and pathological deposition of Aβ was observed in the brain of Tg PS1/APPswe mice treated with anatabine. This is the first study to investigate the impact of chronic anatabine treatment on AD-like pathology and behavior in a transgenic mouse model of AD. Overall, our data show that anatabine reduces β-amyloidosis, neuroinflammation and alleviates some behavioral deficits in Tg PS1/APPswe, supporting further exploration of anatabine as a possible disease modifying agent for the treatment of AD. PMID:26010758

  15. [Hypoxic training of high qualification sportsmen].

    PubMed

    Radziievs'kiĭ, P O; Radziievs'ka, M P

    2003-01-01

    Normobaric intermittent hypoxic training (IHT) is an effective method for improving of of the functional respiration system (FRS) state, increase of aerobic productivity, general and special capacity for work in sportsmen of high qualification. The advantage of the use of intermittent hypoxic training during the preparation of high qualification sportsmen is so that hypoxic hypoxia and hypoxia of load influence on the sportsman organism in different time (IHT is doing during the rest, out of the planned sport training without the influence on it). This is a difference with the hypoxic training in mountain conditions where two types of hypoxia influence on the sportsman organism simultaneously and permanently--hypoxia of load and hypoxic hypoxia, and additive destructive action of the both types of hypoxia may be revealed. High efficacy of intermittent hypoxic training in improving of all parts of sportsmen FRS is a result alternating of hypoxic influences and normoxic intervals between them during which the level of plastic processes remains increased, oxygen tension in arterial blood and tissues increases to normoxic values. After IHT course, the state of respiration organs improves, the respiration volume, part of alveolar ventilation in the minute volume of respiration, saturation of arterial blood by oxygen, haemoglobin content in blood--increase as well as increase economy and efficacy of oxygen regimes of organism, general and special (especially important) physical capacity for work increase too. PMID:12918261

  16. CFTR and sphingolipids mediate hypoxic pulmonary vasoconstriction.

    PubMed

    Tabeling, Christoph; Yu, Hanpo; Wang, Liming; Ranke, Hannes; Goldenberg, Neil M; Zabini, Diana; Noe, Elena; Krauszman, Adrienn; Gutbier, Birgitt; Yin, Jun; Schaefer, Michael; Arenz, Christoph; Hocke, Andreas C; Suttorp, Norbert; Proia, Richard L; Witzenrath, Martin; Kuebler, Wolfgang M

    2015-03-31

    Hypoxic pulmonary vasoconstriction (HPV) optimizes pulmonary ventilation-perfusion matching in regional hypoxia, but promotes pulmonary hypertension in global hypoxia. Ventilation-perfusion mismatch is a major cause of hypoxemia in cystic fibrosis. We hypothesized that cystic fibrosis transmembrane conductance regulator (CFTR) may be critical in HPV, potentially by modulating the response to sphingolipids as mediators of HPV. HPV and ventilation-perfusion mismatch were analyzed in isolated mouse lungs or in vivo. Ca(2+) mobilization and transient receptor potential canonical 6 (TRPC6) translocation were studied in human pulmonary (PASMCs) or coronary (CASMCs) artery smooth muscle cells. CFTR inhibition or deficiency diminished HPV and aggravated ventilation-perfusion mismatch. In PASMCs, hypoxia caused CFTR to interact with TRPC6, whereas CFTR inhibition attenuated hypoxia-induced TRPC6 translocation to caveolae and Ca(2+) mobilization. Ca(2+) mobilization by sphingosine-1-phosphate (S1P) was also attenuated by CFTR inhibition in PASMCs, but amplified in CASMCs. Inhibition of neutral sphingomyelinase (nSMase) blocked HPV, whereas exogenous nSMase caused TRPC6 translocation and vasoconstriction that were blocked by CFTR inhibition. nSMase- and hypoxia-induced vasoconstriction, yet not TRPC6 translocation, were blocked by inhibition or deficiency of sphingosine kinase 1 (SphK1) or antagonism of S1P receptors 2 and 4 (S1P2/4). S1P and nSMase had synergistic effects on pulmonary vasoconstriction that involved TRPC6, phospholipase C, and rho kinase. Our findings demonstrate a central role of CFTR and sphingolipids in HPV. Upon hypoxia, nSMase triggers TRPC6 translocation, which requires its interaction with CFTR. Concomitant SphK1-dependent formation of S1P and activation of S1P2/4 result in phospholipase C-mediated TRPC6 and rho kinase activation, which conjointly trigger vasoconstriction. PMID:25829545

  17. CFTR and sphingolipids mediate hypoxic pulmonary vasoconstriction

    PubMed Central

    Tabeling, Christoph; Yu, Hanpo; Wang, Liming; Ranke, Hannes; Goldenberg, Neil M.; Zabini, Diana; Noe, Elena; Krauszman, Adrienn; Gutbier, Birgitt; Yin, Jun; Schaefer, Michael; Arenz, Christoph; Hocke, Andreas C.; Suttorp, Norbert; Proia, Richard L.; Witzenrath, Martin; Kuebler, Wolfgang M.

    2015-01-01

    Hypoxic pulmonary vasoconstriction (HPV) optimizes pulmonary ventilation-perfusion matching in regional hypoxia, but promotes pulmonary hypertension in global hypoxia. Ventilation-perfusion mismatch is a major cause of hypoxemia in cystic fibrosis. We hypothesized that cystic fibrosis transmembrane conductance regulator (CFTR) may be critical in HPV, potentially by modulating the response to sphingolipids as mediators of HPV. HPV and ventilation-perfusion mismatch were analyzed in isolated mouse lungs or in vivo. Ca2+ mobilization and transient receptor potential canonical 6 (TRPC6) translocation were studied in human pulmonary (PASMCs) or coronary (CASMCs) artery smooth muscle cells. CFTR inhibition or deficiency diminished HPV and aggravated ventilation-perfusion mismatch. In PASMCs, hypoxia caused CFTR to interact with TRPC6, whereas CFTR inhibition attenuated hypoxia-induced TRPC6 translocation to caveolae and Ca2+ mobilization. Ca2+ mobilization by sphingosine-1-phosphate (S1P) was also attenuated by CFTR inhibition in PASMCs, but amplified in CASMCs. Inhibition of neutral sphingomyelinase (nSMase) blocked HPV, whereas exogenous nSMase caused TRPC6 translocation and vasoconstriction that were blocked by CFTR inhibition. nSMase- and hypoxia-induced vasoconstriction, yet not TRPC6 translocation, were blocked by inhibition or deficiency of sphingosine kinase 1 (SphK1) or antagonism of S1P receptors 2 and 4 (S1P2/4). S1P and nSMase had synergistic effects on pulmonary vasoconstriction that involved TRPC6, phospholipase C, and rho kinase. Our findings demonstrate a central role of CFTR and sphingolipids in HPV. Upon hypoxia, nSMase triggers TRPC6 translocation, which requires its interaction with CFTR. Concomitant SphK1-dependent formation of S1P and activation of S1P2/4 result in phospholipase C-mediated TRPC6 and rho kinase activation, which conjointly trigger vasoconstriction. PMID:25829545

  18. Thymocytes, Pre-B Cells, and Organ Changes in a Mouse Model of Chronic Ethanol Ingestion—Absence of Subset-Specific Glucocorticoid-Induced Immune Cell Loss

    PubMed Central

    Cook, Robert T.; Schlueter, Annette J.; Coleman, Ruth A.; Tygrett, Lorraine; Ballas, Zuhair K.; Jerrells, Thomas R.; Nashelsky, Marcus B.; Ray, Nancy B.; Haugen, Thomas H.; Waldschmidt, Thomas J.

    2008-01-01

    Background The well-known immune deficiency of the chronic alcoholic dictates the need for a long-term rodent ethanol administration model to evaluate the baseline immunologic effects of chronic ethanol abuse, and investigate the genetic determinants of those effects. Much published work with rodents has shown clearly that acute ethanol administration and short-term ethanol-containing liquid diets both cause elevated corticosterone and can cause significant thymocyte, pre-B cell and peripheral lymphocyte losses. Such losses may mask more subtle alterations in immune homeostasis, and in any case are generally short-lived compared with the span of chronic ethanol abuse. Thus, it is important to have a model in which long-term immune alterations can be studied free of corticosteroid-induced cell losses. Methods We have utilized chronic 20% (w / v) ethanol in water administration to several mouse strains for prolonged periods of time and evaluated serum corticosterone, immunologic stress parameters, and other organ changes by standard methods. Results We now confirm earlier reports that chronic ethanol in water administration to mice does not produce net elevations of corticosterone, although diurnal variation is altered. Importantly, there is neither selective loss of immune cell populations known to be corticosteroid sensitive, CD4+CD8+ thymocytes and pre-B cells, nor are changes observed in the histologic appearance of the thymus. Nonetheless, there are significant chronic ethanol effects in other tissues, including reduced heart weight, mild hepatic steatosis, alterations of gut flora, increased serum peptidoglycan, and as published elsewhere, immune system abnormalities. Conclusions This model of ethanol administration is convenient, sustainable for up to 1 year, demonstrably feasible in several mouse strains, permits good weight gains in most strains, and results in significant changes in a number of organs. The administration method also will permit modeling of

  19. Impaired Bronchoprotection Is Not Induced by Increased Smooth Muscle Mass in Chronic Treatment In Vivo with Formoterol in Asthmatic Mouse Model

    PubMed Central

    Luo, W; Liu, C-T; Yang, Q-H; Yu, Q; Wang, T

    2014-01-01

    ABSTRACT Objective: Inhaling β2-adrenoceptor agonist is first-line asthma treatment, which is used for both acute relief of and prevention of bronchoconstriction. However, chronic use of β-agonists results in impaired bronchoprotection and increasing occurrences of severe asthma exacerbation, even death in clinical practice. The mechanism of β-adrenoceptor hyposensitivity has not been thoroughly elucidated thus far. Bronchial smooth muscle contraction induces airway narrowing and also mediates airway inflammation. Moreover, bronchial smooth muscle mass significantly increases in asthmatics. We aim to establish an asthmatic model that demonstrated that formoterol induced impaired bronchoprotection and to see whether increased smooth muscle mass played a role in it. Methods: We combined routine allergen challenging (seven weeks) with repeated application of formoterol, formoterol plus budesonide or physiological saline in allergen-sensitized BALB/c mouse. The bronchoprotection mediated by β-agonist was measured in five consecutive weeks. Smooth muscle mass was shown by morphometric analysis, and α-actin expression was detected by western blot. Results: The trend of bronchoprotection was wavy in drug interventional groups, which initially increased and then decreased. Chronic treatment with formoterol significantly impaired bronchoprotection. According to the morphometric analysis and α-actin expression, no significant difference was detected in smooth muscle mass in all groups. Conclusion: This experiment successfully established that a chronic asthmatic mouse model, which manifested typical features of asthmatic patients, when treated chronically with formoterol, showed a loss of bronchoprotection. No significant difference was detected in smooth muscle mass in all groups, which implied some subcellular signalling changes may be the key points. PMID:25803396

  20. The Search for New Hypoxic Cell Radiosensitizers

    PubMed Central

    Mansfield, Carl M.; Kimler, Bruce F.; Cheng, C.C.; Abrahams, Iris L.; Podrebarac, Eugene G.; Wittek, Philip J.; Reddy, Eashwer K.

    1980-01-01

    A number of newly synthesized compounds whose chemical structure suggested possible or remotely possible ability to radiosensitize hypoxic mammalian cells were studied in an in-vitro system. Those compounds that were not excluded because of insolubility or extreme cytotoxicity were tested for radiosensitizing ability. The correlation between chemical structure and radiosensitizing ability will be used for the rational design of additional compounds with a high probability of being effective hypoxic cell radiosensitizers. It is hoped that this will contribute to attempts to improve the cure rate of patients with malignant tumors through the use of radiation therapy and hypoxic cell radiosensitizers. PMID:7401185

  1. The Functional Study of a Chinese Herbal Compounded Antidepressant Medicine – Jie Yu Chu Fan Capsule on Chronic Unpredictable Mild Stress Mouse Model

    PubMed Central

    Ding, Lingling; Zhang, Xiaoyu; Guo, Hongliang; Yuan, Junliang; Li, Shujuan; Hu, Wenli; Golden, Teresa; Wu, Ning

    2015-01-01

    Jie Yu Chu Fan capsule (JYCF) is a new compounded Chinese herbal medicine for the treatment of depression. The present study was designed to explore the antidepressant effects and the possible mechanisms of JYCF by using chronic unpredictable mild stress (CUMS) mouse model and comparing results to that of fluoxetine. Behavioral tests including an open field test, sucrose preference test and forced swim test were performed to evaluate the antidepressant effects of JYCF. The concentrations of monoamine neurotransmitters and metabolic products including norepinephrine (NE), 5-hydroxytryptamine (5-HT), dopamine (DA), 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the cerebral cortex and hippocampus of mice were determined by means of high performance liquid chromatography with electrochemical detection (HPLC-EC). The results show that a successful mouse CUMS model was established through 5 weeks of continuous unpredictable stimulation, as indicated by the significant decrease in sucrose preference and locomotor activity and increase in immobility time in the forced swim test. Chronic treatment of JYCF (1.25, 2.5 and 5 g/kg) and fluoxetine (20mg/kg) significantly reversed the CUMS-induced behavioral abnormalities. JYCF (1.25, 2.5 and 5 g/kg) significantly increased NE in CUMS mouse prefrontal cortex (P < 0.01, P < 0.01, P < 0.05 respectively) and 5-HT in hippocampus (P < 0.05). In summary, our findings suggest that JYCF exerts comparable antidepressant-like effects to that of fluoxetine in CUMS mice. Besides, the antidepressant-like effect of JYCF is mediated by the increase of monoaminergic transmitters including 5-HT and NE. PMID:26186537

  2. Potential carcinogenic effects of cigarette smoke and Swedish moist snuff on pancreas: a study using a transgenic mouse model of chronic pancreatitis.

    PubMed

    Song, Zhigang; Bhagat, Govind; Quante, Michael; Baik, Gwang Ho; Marrache, Frederic; Tu, Shui Ping; Zhao, Chun-Mei; Chen, Duan; Dannenberg, Andrew J; Wang, Timothy C

    2010-03-01

    The risk of pancreatic cancer is increased in both Snus (the Swedish variant of oral smokeless tobacco) users and, to a greater extent, in cigarette smokers. Concurrent chronic pancreatitis further increases the risk in cigarette smokers. Little is known about the mechanism by which cigarette smoke or Snus increase the risk of pancreatic cancer in individuals with chronic pancreatitis. This study examined the carcinogenic effects of an aqueous extract of cigarette smoke (tobacco smoke, TS) or Snus in an Elastase-IL-1beta transgenic mouse model of chronic pancreatitis. Both transgenic and wild-type (WT) mice were fed diluted TS water or Snus-containing diet for up to 15 months, and monitored for phenotypic and molecular changes in the pancreas. Both TS- and Snus-treated Elastase-IL-1beta mice, but not WT mice, developed significant pancreatic ductal epithelial flattening and severe glandular atrophy compared with untreated transgenic mice. Ductal epithelial cells displayed a high proliferative index, minimal apoptosis, and induction of COX-2 in the setting of chronic inflammation. Up-regulation of TNF-alpha correlated with the onset of severe glandular atrophy. In comparison with Snus-treated mice, TS-Elastase-IL-1beta mice had an earlier onset and a greater extent of phenotypic changes, which were associated with up-regulation of TNF-alpha and increased expression of IL-6, TGF-beta, and SDF-1. Collectively, these findings provide new insights into the mechanism by which tobacco products are likely to promote carcinogenesis in the setting of chronic pancreatitis. PMID:20065943

  3. Chronic variable stress in fathers alters paternal and social behavior but not pup development in the biparental California mouse (Peromyscus californicus)

    PubMed Central

    Harris, Breanna N.; de Jong, Trynke R.; Yang, Vanessa; Saltzman, Wendy

    2013-01-01

    Stress and chronically elevated glucocorticoid levels have been shown to disrupt parental behavior in mothers; however, almost no studies have investigated corresponding effects in fathers. The present experiment tested the hypothesis that chronic variable stress inhibits paternal behavior and consequently alters pup development in the monogamous, biparental California mouse (Peromyscus californicus). First-time fathers were assigned to one of three experimental groups: chronic variable stress (CVS, n=8), separation control (SC, n=7), or unmanipulated control (UC, n=8). The CVS paradigm (3 stressors per day for 7 days) successfully stressed mice, as evidenced by increased baseline plasma corticosterone concentrations, increased adrenal mass, decreased thymus mass, and a decrease in body mass over time. CVS altered paternal and social behavior of fathers, but major differences were observed only on day 6 of the 7-day paradigm. At that time point, CVS fathers spent less time with their pairmate and pups, and more time autogrooming, as compared to UC fathers; SC fathers spent more time behaving paternally and grooming the female mate than CVS and UC fathers. Thus, CVS blocked the separation-induced increase in social behaviors observed in the SC fathers. Nonetheless, chronic stress in fathers did not appear to alter survival or development of their offspring: pups from the three experimental conditions did not differ in body mass gain over time, in day of eye opening, or in basal or post-stress corticosterone levels. These results demonstrate that chronic stress can transiently disrupt paternal and social behavior in P. californicus fathers, but does not alter pup development or survival under controlled, nonchallenging laboratory conditions. PMID:24157379

  4. In Vivo Acute on Chronic Ethanol Effects in Liver: A Mouse Model Exhibiting Exacerbated Injury, Altered Metabolic and Epigenetic Responses

    PubMed Central

    Shukla, Shivendra D.; Aroor, Annayya R.; Restrepo, Ricardo; Kharbanda, Kusum K.; Ibdah, Jamal A.

    2015-01-01

    Chronic alcoholics who also binge drink (i.e., acute on chronic) are prone to an exacerbated liver injury but its mechanism is not understood. We therefore investigated the in vivo effects of chronic and binge ethanol ingestion and compared to chronic ethanol followed by three repeat binge ethanol on the liver of male C57/BL6 mice fed ethanol in liquid diet (4%) for four weeks followed by binge ethanol (intragastric administration, 3.5 g/kg body weight, three doses, 12h apart). Chronic followed by binge ethanol exacerbated fat accumulation, necrosis, decrease in hepatic SAM and SAM:SAH ratio, increase in adenosine levels, and elevated CYP2E1 levels. Histone H3 lysine acetylation (H3AcK9), dually modified phosphoacetylated histone H3 (H3AcK9/PS10), and phosphorylated H2AX increased after binge whereas phosphorylation of histone H3 ser 10 (H3S10) and H3 ser 28 (H3S28) increased after chronic ethanol-binge. Histone H3 lysine 4 and 9 dimethylation increased with a marked dimethylation in H3K9 in chronic ethanol binge group. Trimethylated histone H3 levels did not change. Nuclear levels of histone acetyl transferase GCN5 and histone deacetylase HDAC3 were elevated whereas phospho-CREB decreased in a distinctive manner. Taken together, acute on chronic ethanol ingestion caused amplification of liver injury and elicited characteristic profiles of histone modifications, metabolic alterations, and changes in nuclear protein levels. These findings demonstrate that chronic ethanol exposure renders liver more susceptible to repeat acute/binge ethanol induced acceleration of alcoholic liver disease. PMID:26610587

  5. Chronic 5-HT4 receptor agonist treatment restores learning and memory deficits in a neuroendocrine mouse model of anxiety/depression.

    PubMed

    Darcet, Flavie; Gardier, Alain M; David, Denis J; Guilloux, Jean-Philippe

    2016-03-11

    Cognitive disturbances are often reported as serious invalidating symptoms in patients suffering from major depression disorders (MDD) and are not fully corrected by classical monoaminergic antidepressant drugs. If the role of 5-HT4 receptor agonists as cognitive enhancers is well established in naïve animals or in animal models of cognitive impairment, their cognitive effects in the context of stress need to be examined. Using a mouse model of anxiety/depression (CORT model), we reported that a chronic 5-HT4 agonist treatment (RS67333, 1.5mg/kg/day) restored chronic corticosterone-induced cognitive deficits, including episodic-like, associative and spatial learning and memory impairments. On the contrary, a chronic monoaminergic antidepressant drug treatment with fluoxetine (18mg/kg/day) only partially restored spatial learning and memory deficits and had no effect in the associative/contextual task. These results suggest differential mechanisms underlying cognitive effects of these drugs. Finally, the present study highlights 5-HT4 receptor stimulation as a promising therapeutic mechanism to alleviate cognitive symptoms related to MDD. PMID:26850572

  6. Novel Roles for Protein Kinase Cδ-dependent Signaling Pathways in Acute Hypoxic Stress-induced Autophagy*S⃞

    PubMed Central

    Chen, Jo-Lin; Lin, Her H.; Kim, Kwang-Jin; Lin, Anning; Forman, Henry J.; Ann, David K.

    2008-01-01

    Macroautophagy, a tightly orchestrated intracellular process for bulk degradation of cytoplasmic proteins or organelles, is believed to be essential for cell survival or death in response to stress conditions. Recent observations indicate that autophagy is an adaptive response in cells subjected to prolonged hypoxia. However, the signaling mechanisms that activate autophagy under acute hypoxic stress are not clearly understood. In this study, we show that acute hypoxic stress by treatment with 1% O2 or desferroxamine, a hypoxia-mimetic agent, of cells renders a rapid induction of LC3-II level changes and green fluorescent protein-LC3 puncta accumulation, hallmarks of autophagic processing, and that this process involves protein kinase Cδ (PKCδ), and occurs prior to the induction of BNIP3 (Bcl-2/adenovirus E1B 19-kDa interacting protein 3). Interestingly, hypoxic stress leads to a rapid and transient activation of JNK in Pa-4 or mouse embryo fibroblast cells. Acute hypoxic stress-induced changes in LC3-II level and JNK activation are attenuated in Pa-4 cells by dominant negative PKCδKD or in mouse embryo fibroblast/PKCδ-null cells. Intriguingly, the requirement of PKCδ is not apparent for starvation-induced autophagy. The importance of PKCδ in hypoxic stress-induced adaptive responses is further supported by our findings that inhibition of PKCδ-facilitated autophagy by 3-methyladenine or Atg5 knock-out renders a greater prevalence of cell death following prolonged desferroxamine treatment, whereas PKCδ- or JNK1-deficient cells exhibit resistance to extended hypoxic exposure. These results uncover dual roles of PKCδ-dependent signaling in the cell fate determination upon hypoxic exposure. PMID:18836180

  7. Deletion of STAT5a/b in Vascular Smooth Muscle Abrogates the Male Bias in Hypoxic Pulmonary Hypertension in Mice: Implications in the Human Disease

    PubMed Central

    Yang, Yang-Ming; Yuan, Huijuan; Edwards, John G; Skayian, Yester; Ochani, Kanta; Miller, Edmund J; Sehgal, Pravin B

    2014-01-01

    Chronic hypoxia typically elicits pulmonary hypertension (PH) in mice with a male-dominant phenotype. There is an opposite-sex bias in human PH, with a higher prevalence in women, but greater survival (the “estrogen paradox”). We investigated the involvement of the STAT5a/b species, previously established to mediate sexual dimorphism in other contexts, in the sex bias in PH. Mice with heterozygous or homozygous deletions of the STAT5a/b locus in vascular smooth muscle cells (SMCs) were generated in crosses between STAT5a/bfl/fl and transgelin (SM22α)-Cre+/+ parents. Wild-type (wt ) males subjected to chronic hypoxia showed significant PH and pulmonary arterial remodeling, with wt females showing minimal changes (a male-dominant phenotype). However, in conditional STAT5+/− or STAT5−/− mice, hypoxic females showed the severest manifestations of PH (a female-dominant phenotype). Immunofluorescence studies on human lung sections showed that obliterative pulmonary arterial lesions in patients with idiopathic pulmonary arterial hypertension (IPAH) or hereditary pulmonary arterial hypertension (HPAH), both male and female, overall had reduced STAT5a/b, reduced PY-STAT5 and reduced endoplasmic reticulum (ER) GTPase atlastin-3 (ATL3). Studies of SMCs and endothelial cell (EC) lines derived from vessels isolated from lungs of male and female IPAH patients and controls revealed instances of coordinate reductions in STAT5a, STAT5b and ATL3 in IPAH-derived cells, including SMCs and ECs from the same patient. Taken together, these data provide the first definitive evidence for a contribution of STAT5a/b to the sex bias in PH in the hypoxic mouse and implicate reduced STAT5 in the pathogenesis of the human disease. PMID:25470773

  8. Acetylcholinesterase activity in regions of mouse brain following acute and chronic treatment with a benzodiazepine inverse agonist.

    PubMed Central

    Appleyard, M. E.; Taylor, S. C.; Little, H. J.

    1990-01-01

    1. Chronic administration of the benzodiazepine inverse agonist FG 7142 has previously been shown to induce seizure activity in mice. In the present study we have investigated the effects of acute and chronic treatment with FG 7142 in mice on the levels of acetylcholinesterase activity in cortex, hippocampus, midbrain and striatum. We have also investigated the effects of acute and chronic stress in the form of handling (vehicle-injection) on acetylcholinesterase levels. 2. A single dose of FG 7142 produced a marked elevation of total acetylcholinesterase activities in the hippocampus and midbrain when compared with vehicle-injected control levels, but the levels were not different from those in unhandled animals. 3. Acute stress, in the form of vehicle-injection produced decreases in cortical and hippocampal soluble acetylcholinesterase activity but FG 7142 had no effect upon these stress-induced changes. 4. Total cortical and hippocampal acetylcholinesterase activities were increased by 56% and 16% respectively in the chronic FG 7142-treated mice that exhibited seizure activity (compared with vehicle-injected controls). 5. Soluble acetylcholinesterase activity in the midbrain was decreased to 82% of control levels only in animals that had undergone FG 7142-induced kindling. Smaller or no changes in acetylcholinesterase activity in the midbrain were observed in chronically FG 7142-treated animals that exhibited no seizure activity. 6. Mice that did not demonstrate seizure activity in response to chronic FG 7142 treatment showed alterations in the soluble acetylcholinesterase activities of the hippocampus and midbrain.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1963800

  9. Essential Contributions of Serotonin Transporter Inhibition to the Acute and Chronic Actions of Fluoxetine and Citalopram in the SERT Met172 Mouse.

    PubMed

    Nackenoff, Alex G; Moussa-Tooks, Alexandra B; McMeekin, Austin M; Veenstra-VanderWeele, Jeremy; Blakely, Randy D

    2016-06-01

    Depression is a common mental illness and a leading cause of disability. The most widely prescribed antidepressant medications are serotonin (5-HT) selective reuptake inhibitors (SSRIs). Although there is much support for 5-HT transporter (SERT) antagonism as a basis of antidepressant efficacy, this evidence is indirect and other targets and mechanisms have been proposed. In order to distinguish SERT-dependent and -independent effects of SSRIs, we developed a knock-in mouse model whereby high-affinity interactions of many antidepressants at SERT have been ablated via knock-in substitution (SERT Met172) without disrupting 5-HT recognition or uptake. Here we utilize the C57BL/6J SERT Met172 model to evaluate SERT dependence for the actions of two widely prescribed SSRIs, fluoxetine and citalopram, in tests sensitive to acute and chronic actions of antidepressants. In the tail suspension and forced swim tests, fluoxetine and citalopram fail to reduce immobility in SERT Met172 mice. In addition, SERT Met172 mice are insensitive to chronic fluoxetine and citalopram administration in the novelty induced hypophagia test (NIH) and fail to exhibit enhanced proliferation or survival of hippocampal stem cells. In both acute and chronic studies, SERT Met172 mice maintained sensitivity to paroxetine, an antidepressant that is unaffected by the Met172 mutation. Together, these studies provide definitive support for an essential role of SERT antagonism in the acute and chronic actions of two commonly used SSRIs in these tests, and reinforce the utility of the SERT Met172 model for isolating SERT/5-HT contributions of drug actions in vivo. PMID:26514584

  10. Redistribution of pulmonary blood flow during hypoxic exercise.

    PubMed

    Kuwahira, I; Moue, Y; Urano, T; Kamiya, U; Iwamoto, T; Ishii, M; Clancy, R L; Gonzalez, N C

    2001-08-01

    Pulmonary blood flow (PBF) distribution was studied at rest and during exercise in rats acclimatized to chronic hypoxia (barometric pressure [PB] 370 Torr for 3 weeks, A rats) and non-acclimatized (NA) littermates. Both A and NA rats exercised in hypoxia (inspired O2 pressure [PIO2] approximately 70 Torr) or in normoxia (PlO2 approximately 145 Torr). PBF distribution was determined using fluorescent-labeled microspheres injected into the right atrium. The lungs were cut into 28 samples to determine relative scatter of specific PBF ([sample fluorescence intensity/sample dry weight)/(total lung fluorescence intensity/total lung dry weight]). Exercise produced redistribution of PBF both in NA and A rats, and this effect was larger in hypoxia than in normoxia, with minimal redistribution occurring during normoxic exercise in NA rats. The pattern of distribution varies considerably among individual animals. As a result of distribution, the previous high flow areas would be overperfused during hypoxic exercise in some rats. The results support the concept that hypoxic pulmonary vasoconstriction is not uniform and suggest that the combination of hypoxia and exercise may lead to overperfusion and capillary leak in some individuals. PMID:11531029

  11. Colocalization of insulin-like growth factor-1 receptor and T type Cav3.2 channel in dorsal root ganglia in chronic inflammatory pain mouse model.

    PubMed

    Lin, Si-Fang; Yu, Xiao-Lu; Wang, Bing; Zhang, Ya-Jun; Sun, Yan-Gang; Liu, Xing-Jun

    2016-07-01

    Insulin-like growth factor-1 (IGF-1) is a neurotrophic factor and plays important roles in the nervous system. Increasing evidence supports that IGF-1 contributes to pain hypersensitivity through its insulin-like growth factor-1 receptor (IGF-1R) by activating IGF-1R/Akt or MAPK signaling pathways, whereas T-type Cav3.2 channel can facilitate and amplify pain signals originating from the sensory periphery. A recent study showed that activated IGF-1R can increase T-type Cav3.2 channel currents and further activate the G protein-dependent PKCα pathway to contribute to inflammatory pain sensitivity. However, the colocalization of IGF-1R and Cav3.2 in mouse dorsal root ganglion (DRG) under chronic inflammatory pain conditions remains elusive. In this study, we investigated changes in the expression of IGF-1R and the Cav3.2 channel, and their colocalization in mouse DRGs in chronic inflammatory pain condition (induced by complete Freund's adjuvant intraplanter injection) using real-time RT-PCR and immunohistochemistry approaches to confirm that Cav3.2 channel can mediate pain facilitation following IGF-1/IGF-1R signaling. We found that IGF-1R was expressed extensively in DRG neurons including small-, medium-, and large-sized neurons, whereas Cav3.2 channel was expressed exclusively in small-sized DRG neurons of naive mice. Expression of Cav3.2, but not IGF-1R, and colocalization of Cav3.2 and IGF-1R were increased in lumbar (L)4-L6 primary sensory neurons in DRGs of mice in chronic inflammatory pain. Moreover, the increased colocalization of IGF-1R and Cav3.2 is exclusively localized in small- and medium-sized primary sensory neurons. Our findings provided morphological evidence that T-type Cav3.2 channel, at least partially, mediates the pain facilitation of IGF-1/IGF-1R signaling in chronic inflammatory pain condition. PMID:27213932

  12. Alterations in Mouse Hypothalamic Adipokine Gene Expression and Leptin Signaling following Chronic Spinal Cord Injury and with Advanced Age

    PubMed Central

    Bigford, Gregory E.; Bracchi-Ricard, Valerie C.; Nash, Mark S.; Bethea, John R.

    2012-01-01

    Chronic spinal cord injury (SCI) results in an accelerated trajectory of several cardiovascular disease (CVD) risk factors and related aging characteristics, however the molecular mechanisms that are activated have not been explored. Adipokines and leptin signaling are known to play a critical role in neuro-endocrine regulation of energy metabolism, and are now implicated in central inflammatory processes associated with CVD. Here, we examine hypothalamic adipokine gene expression and leptin signaling in response to chronic spinal cord injury and with advanced age. We demonstrate significant changes in fasting-induced adipose factor (FIAF), resistin (Rstn), long-form leptin receptor (LepRb) and suppressor of cytokine-3 (SOCS3) gene expression following chronic SCI and with advanced age. LepRb and Jak2/stat3 signaling is significantly decreased and the leptin signaling inhibitor SOCS3 is significantly elevated with chronic SCI and advanced age. In addition, we investigate endoplasmic reticulum (ER) stress and activation of the uncoupled protein response (UPR) as a biological hallmark of leptin resistance. We observe the activation of the ER stress/UPR proteins IRE1, PERK, and eIF2alpha, demonstrating leptin resistance in chronic SCI and with advanced age. These findings provide evidence for adipokine-mediated inflammatory responses and leptin resistance as contributing to neuro-endocrine dysfunction and CVD risk following SCI and with advanced age. Understanding the underlying mechanisms contributing to SCI and age related CVD may provide insight that will help direct specific therapeutic interventions. PMID:22815920

  13. Effects of systemic indomethacin, meclizine, and BW755C on chronic ultraviolet B-induced effects in hairless mouse skin.

    PubMed

    Kochevar, I E; Moran, M; Lyon, N; Flotte, T; Siebert, E; Gange, R W

    1993-02-01

    Chronic exposure of hairless mice to ultraviolet B (UVB) radiation is associated with inflammation as well as an altered macromolecular composition of the dermis. This study was designed to determine whether or not various systemic anti-inflammatory agents inhibit chronic UVB-induced changes in the macromolecular content of the dermis and, if so, whether each agent had the same or different effects. The agents and doses were chosen for their ability to inhibit the changes induced by a single exposure to UVB radiation (increased vasopermeability, neutrophil accumulation, and skin-fold thickness). Indomethacin, a cyclooxygenase inhibitor, and meclizine, an H1 histamine receptor antagonist, were administered from slow-release pellets. BW755C, a combined cyclooxygenase and lipoxygenase inhibitor, was administered intraperitoneally 30 min prior to UVB exposure. Animals were exposed to UVB three times per week for 20-26 weeks or were unirradiated. The elastin, glycosaminoglycan and collagen content of the skin were determined by measuring the desmosine, uronic acid, and hydroxyproline levels, respectively. The amount of each macromolecule per area of skin increased after chronic UVB exposure. The increase in desmosine was inhibited by indomethacin; the increase in hydroxyproline was inhibited by meclizine and BW755C. None of the agents inhibited the uronic acid increase. These results suggest that chronic inflammation contributes to the dermal changes seen in chronically UVB-exposed skin and that different inflammatory mediators are involved in the increases observed in elastin, glycosaminoglycans, and collagen. PMID:8429241

  14. Behavioral Abnormalities in a Mouse Model of Chronic Toxoplasmosis Are Associated with MAG1 Antibody Levels and Cyst Burden.

    PubMed

    Xiao, Jianchun; Li, Ye; Prandovszky, Emese; Kannan, Geetha; Viscidi, Raphael P; Pletnikov, Mikhail V; Yolken, Robert H

    2016-04-01

    There is marked variation in the human response to Toxoplasma gondii infection. Epidemiological studies indicate associations between strain virulence and severity of toxoplasmosis. Animal studies on the pathogenic effect of chronic infection focused on relatively avirulent strains (e.g. type II) because they can easily establish latent infections in mice, defined by the presence of bradyzoite-containing cysts. To provide insight into virulent strain-related severity of human toxoplasmosis, we established a chronic model of the virulent type I strain using outbred mice. We found that type I-exposed mice displayed variable outcomes ranging from aborted to severe infections. According to antibody profiles, we found that most of mice generated antibodies against T. gondii organism but varied greatly in the production of antibodies against matrix antigen MAG1. There was a strong correlation between MAG1 antibody level and brain cyst burden in chronically infected mice (r = 0.82, p = 0.0021). We found that mice with high MAG1 antibody level displayed lower weight, behavioral changes, altered levels of gene expression and immune activation. The most striking change in behavior we discovered was a blunted response to amphetamine-trigged locomotor activity. The extent of most changes was directly correlated with levels of MAG1 antibody. These changes were not found in mice with less cyst burden or mice that were acutely but not chronically infected. Our finding highlights the critical role of cyst burden in a range of disease severity during chronic infection, the predictive value of MAG1 antibody level to brain cyst burden and to changes in behavior or other pathology in chronically infected mice. Our finding may have important implications for understanding the heterogeneous effects of T. gondii infections in human. PMID:27124472

  15. Behavioral Abnormalities in a Mouse Model of Chronic Toxoplasmosis Are Associated with MAG1 Antibody Levels and Cyst Burden

    PubMed Central

    Xiao, Jianchun; Li, Ye; Prandovszky, Emese; Kannan, Geetha; Viscidi, Raphael P.; Pletnikov, Mikhail V.; Yolken, Robert H.

    2016-01-01

    There is marked variation in the human response to Toxoplasma gondii infection. Epidemiological studies indicate associations between strain virulence and severity of toxoplasmosis. Animal studies on the pathogenic effect of chronic infection focused on relatively avirulent strains (e.g. type II) because they can easily establish latent infections in mice, defined by the presence of bradyzoite-containing cysts. To provide insight into virulent strain-related severity of human toxoplasmosis, we established a chronic model of the virulent type I strain using outbred mice. We found that type I-exposed mice displayed variable outcomes ranging from aborted to severe infections. According to antibody profiles, we found that most of mice generated antibodies against T. gondii organism but varied greatly in the production of antibodies against matrix antigen MAG1. There was a strong correlation between MAG1 antibody level and brain cyst burden in chronically infected mice (r = 0.82, p = 0.0021). We found that mice with high MAG1 antibody level displayed lower weight, behavioral changes, altered levels of gene expression and immune activation. The most striking change in behavior we discovered was a blunted response to amphetamine-trigged locomotor activity. The extent of most changes was directly correlated with levels of MAG1 antibody. These changes were not found in mice with less cyst burden or mice that were acutely but not chronically infected. Our finding highlights the critical role of cyst burden in a range of disease severity during chronic infection, the predictive value of MAG1 antibody level to brain cyst burden and to changes in behavior or other pathology in chronically infected mice. Our finding may have important implications for understanding the heterogeneous effects of T. gondii infections in human. PMID:27124472

  16. Protein kinase C α inhibition prevents peritoneal damage in a mouse model of chronic peritoneal exposure to high-glucose dialysate.

    PubMed

    Wang, Le; Balzer, Michael S; Rong, Song; Menne, Jan; von Vietinghoff, Sibylle; Dong, Lei; Gueler, Faikah; Jang, Mi-Sun; Xu, Gang; Timrott, Kai; Tkachuk, Sergey; Hiss, Marcus; Haller, Hermann; Shushakova, Nelli

    2016-06-01

    Chronic exposure to commercial glucose-based peritoneal dialysis fluids during peritoneal dialysis induces peritoneal membrane damage leading to ultrafiltration failure. In this study the role of protein kinase C (PKC) α in peritoneal membrane damage was investigated in a mouse model of peritoneal dialysis. We used 2 different approaches: blockade of biological activity of PKCα by intraperitoneal application of the conventional PKC inhibitor Go6976 in C57BL/6 wild-type mice and PKCα-deficient mice on a 129/Sv genetic background. Daily administration of peritoneal dialysis fluid for 5 weeks induced peritoneal upregulation and activation of PKCα accompanied by epithelial-to-mesenchymal transition of peritoneal mesothelial cells, peritoneal membrane fibrosis, neoangiogenesis, and macrophage and T cell infiltration, paralleled by reduced ultrafiltration capacity. All pathological changes were prevented by PKCα blockade or deficiency. Moreover, treatment with Go6976 and PKCα deficiency resulted in strong reduction of proinflammatory, profibrotic, and proangiogenic mediators. In cell culture experiments, both treatment with Go6976 and PKCα deficiency prevented peritoneal dialysis fluid-induced release of MCP-1 from mouse peritoneal mesothelial cells and ameliorated transforming growth factor-β1-induced epithelial-to-mesenchymal transition and peritoneal dialysis fluid-induced MCP-1 release in human peritoneal mesothelial cells. Thus, PKCα plays a crucial role in the pathophysiology of peritoneal membrane dysfunction induced by peritoneal dialysis fluids, and we suggest that its therapeutic inhibition might be a valuable treatment option for peritoneal dialysis patients. PMID:27142955

  17. TCL1 transgenic mouse model as a tool for the study of therapeutic targets and microenvironment in human B-cell chronic lymphocytic leukemia

    PubMed Central

    Bresin, A; D'Abundo, L; Narducci, M G; Fiorenza, M T; Croce, C M; Negrini, M; Russo, G

    2016-01-01

    Chronic lymphocytic leukemia (CLL) is a B-cell malignancy with a mature phenotype. In spite of its relatively indolent nature, no radical cure is as yet available. CLL is not associated with either a unique cytogenetic or a molecular defect, which might have been a potential therapeutic target. Instead, several factors are involved in disease development, such as environmental signals which interact with genetic abnormalities to promote survival, proliferation and an immune surveillance escape. Among these, PI3-Kinase signal pathway alterations are nowadays considered to be clearly important. The TCL1 gene, an AKT co-activator, is the cause of a mature T-cell leukemia, as well as being highly expressed in all B-CLL. A TCL1 transgenic mouse which reproduces leukemia with a distinct immunophenotype and similar to the course of the human B-CLL was developed several years ago and is widely used by many groups. This is a review of the CLL biology arising from work of many independent investigators who have used TCL1 transgenic mouse model focusing on pathogenetic, microenviroment and therapeutic targets. PMID:26821067

  18. Divergent Inflammatory, Fibrogenic, and Liver Progenitor Cell Dynamics in Two Common Mouse Models of Chronic Liver Injury.

    PubMed

    Köhn-Gaone, Julia; Dwyer, Benjamin J; Grzelak, Candice A; Miller, Gregory; Shackel, Nicholas A; Ramm, Grant A; McCaughan, Geoffrey W; Elsegood, Caryn L; Olynyk, John K; Tirnitz-Parker, Janina E E

    2016-07-01

    Complications of end-stage chronic liver disease signify a major cause of mortality worldwide. Irrespective of the underlying cause, most chronic liver diseases are characterized by hepatocellular necrosis, inflammation, fibrosis, and proliferation of liver progenitor cells or ductular reactions. Vast differences exist between experimental models that mimic these processes, and their identification is fundamental for translational research. We compared two common murine models of chronic liver disease: the choline-deficient, ethionine-supplemented (CDE) diet versus thioacetamide (TAA) supplementation. Markers of liver injury, including serum alanine transaminase levels, apoptosis, hepatic fat loading, and oxidative stress, as well as inflammatory, fibrogenic and liver progenitor cell responses, were assessed at days 3, 7, 14, 21, and 42. This study revealed remarkable differences between the models. It identified periportal injury and fibrosis with an early peak and slow normalization of all parameters in the CDE regimen, whereas TAA-treated mice had pericentral patterns of progressive injury and fibrosis, resulting in a more severe hepatic injury phenotype. This study is the first to resolve two different patterns of injury and fibrosis in the CDE and TAA model and to indisputably identify the fibrosis pattern in the TAA model as driven from the pericentral vein region. Our data provide a valuable foundation for future work using the CDE and TAA regimens to model a variety of human chronic liver diseases. PMID:27181403

  19. Neurotropin attenuates local inflammatory response and inhibits demyelination induced by chronic constriction injury of the mouse sciatic nerve.

    PubMed

    Nishimoto, Shunsuke; Okada, Kiyoshi; Tanaka, Hiroyuki; Okamoto, Michio; Fujisawa, Hiroki; Okada, Tomoyuki; Naiki, Mitsuru; Murase, Tsuyoshi; Yoshikawa, Hideki

    2016-07-01

    Neuropathic pain caused by nerve damage in the central and/or peripheral nervous systems is a refractory disorder and the management of such chronic pain has become a major issue. Neurotropin is a drug widely used in Japan and China to treat chronic pain. Although Neurotropin has been demonstrated to suppress chronic pain through the descending pain inhibitory system, the mechanism of analgesic action in the peripheral nervous system remains to be elucidated. In this study, we investigated the local effects of Neurotropin on peripheral nerve damage in a chronic constriction injury (CCI) model. Neurotropin reduced mRNA expressions of IL-1β, IL-6, and TNF-α in the sciatic nerve 1 day after the injury. Activation of Erk was also inhibited locally in the Neurotropin treatment group. Since Erk activation results in demyelination along with dedifferentiation of Schwann cells, we investigated the expression level of myelin basic protein. Five days after the injury, Neurotropin attenuated the downregulation of myelin basic protein in the sciatic nerve in the CCI model. Local effects of Neurotropin around the injury site may result in discovery of new treatments for not only neuropathic pain but also demyelinating diseases and peripheral nervous system injury. PMID:27233579

  20. A novel mouse model for the study of the inhibitory effects of chronic ethanol exposure on direct bone formation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Excessive alcohol consumption has been reported to interfere with human bone homeostasis and repair in multiple ways. Previous studies have demonstrated that chronic ethanol exposure in the rat via an intragastric dietary delivery system inhibits direct bone formation during distraction osteogenesis...

  1. Up-regulation of nucleotide excision repair in mouse lung and liver following chronic exposure to aflatoxin B{sub 1} and its dependence on p53 genotype

    SciTech Connect

    Mulder, Jeanne E.; Bondy, Genevieve S.; Mehta, Rekha; Massey, Thomas E.

    2014-03-01

    Aflatoxin B{sub 1} (AFB{sub 1}) is biotransformed in vivo into an epoxide metabolite that forms DNA adducts that may induce cancer if not repaired. p53 is a tumor suppressor gene implicated in the regulation of global nucleotide excision repair (NER). Male heterozygous p53 knockout (B6.129-Trp53{sup tm1Brd}N5, Taconic) and wild-type mice were exposed to 0, 0.2 or 1.0 ppm AFB{sub 1} for 26 weeks. NER activity was assessed with an in vitro assay, using AFB{sub 1}-epoxide adducted plasmid DNA as a substrate. For wild-type mice, repair of AFB{sub 1}–N7-Gua adducts was 124% and 96% greater in lung extracts from mice exposed to 0.2 ppm and 1.0 ppm AFB{sub 1} respectively, and 224% greater in liver extracts from mice exposed to 0.2 ppm AFB{sub 1} (p < 0.05). In heterozygous p53 knockout mice, repair of AFB{sub 1}–N7-Gua was only 45% greater in lung extracts from mice exposed to 0.2 ppm AFB{sub 1} (p < 0.05), and no effect was observed in lung extracts from mice treated with 1.0 ppm AFB{sub 1} or in liver extracts from mice treated with either AFB{sub 1} concentration. p53 genotype did not affect basal levels of repair. AFB{sub 1} exposure did not alter repair of AFB{sub 1}-derived formamidopyrimidine adducts in lung or liver extracts of either mouse genotype nor did it affect XPA or XPB protein levels. In summary, chronic exposure to AFB{sub 1} increased NER activity in wild-type mice, and this response was diminished in heterozygous p53 knockout mice, indicating that loss of one allele of p53 limits the ability of NER to be up-regulated in response to DNA damage. - Highlights: • Mice are chronically exposed to low doses of the mycotoxin aflatoxin B{sub 1} (AFB{sub 1}). • The effects of AFB{sub 1} and p53 status on nucleotide excision repair are investigated. • AFB{sub 1} increases nucleotide excision repair in wild type mouse lung and liver. • This increase is attenuated in p53 heterozygous mouse lung and liver. • Results portray the role of p53 in

  2. Angiotensin II prevents hypoxic pulmonary hypertension and vascular changes in rat

    SciTech Connect

    Rabinovitch, M.; Mullen, M.; Rosenberg, H.C.; Maruyama, K.; O'Brodovich, H.; Olley, P.M. )

    1988-03-01

    Angiotensin II, a vasoconstrictor, has been previously demonstrated to produce a secondary vasodilatation due to release of prostaglandins. Because of this effect, the authors investigated whether infusion of exogenous angiotensin II via miniosmopumps in rats during a 1-wk exposure to chronic hypobaric hypoxia might prevent pulmonary hypertension, right ventricular hypertrophy, and vascular changes. They instrumented the rats with indwelling cardiovascular catheters and compared the hemodynamic and structural response in animals given angiotensin II, indomethacin in addition to angiotensin II (to block prostaglandin production), or saline with or without indomethacin. They then determine whether angiotensin II infusion also prevents acute hypoxic pulmonary vasoconstriction. They observed that exogenous angiotensin II infusion abolished the rise in pulmonary artery pressure, the right ventricular hypertrophy, and the vascular changes induced during chronic hypoxia in control saline-infused rats with or without indomethacin. The protective effects of angiotensin II was lost when indomethacin was given to block prostaglandin synthesis. During acute hypoxia, both antiotensin II and prostacyclin infusion similarly prevented the rise in pulmonary artery pressure observed in saline-infused rats and in rats given indomethacin or saralasin in addition to angiotensin II. Thus exogenous angiotensin II infusion prevents chronic hypoxic pulmonary hypertension, associated right ventricular hypertrophy, and vascular changes and blocks acute hypoxic pulmonary hypertension, and this is likely related to its ability to release vasodilator prostaglandins.

  3. Chronic P7C3 treatment restores hippocampal neurogenesis in the Ts65Dn mouse model of Down Syndrome [Corrected].

    PubMed

    Latchney, Sarah E; Jaramillo, Thomas C; Rivera, Phillip D; Eisch, Amelia J; Powell, Craig M

    2015-03-30

    Down syndrome (DS) is the most common genetic cause of intellectual disability and developmental delay. In addition to cognitive dysfunction, DS patients are marked by diminished neurogenesis, a neuropathological feature also found in the Ts65Dn mouse model of DS. Interestingly, manipulations that enhance neurogenesis - like environmental enrichment or pharmacological agents - improve cognition in Ts65Dn mice. P7C3 is a proneurogenic compound that enhances hippocampal neurogenesis, cell survival, and promotes cognition in aged animals. However, this compound has not been tested in the Ts65Dn mouse model of DS. We hypothesized that P7C3 treatment would reverse or ameliorate the neurogenic deficits in Ts65Dn mice. To test this, adult Ts65Dn and age-matched wild-type (WT) mice were administered vehicle or P7C3 twice daily for 3 months. After 3 months, brains were examined for indices of neurogenesis, including quantification of Ki67, DCX, activated caspase-3 (AC3), and surviving BrdU-immunoreactive(+) cells in the granule cell layer (GCL) of the hippocampal dentate gyrus. P7C3 had no effect on total Ki67+, DCX+, AC3+, or surviving BrdU+ cells in WT mice relative to vehicle. GCL volume was also not changed. In keeping with our hypothesis, however, P7C3-treated Ts65Dn mice had a significant increase in total Ki67+, DCX+, and surviving BrdU+ cells relative to vehicle. P7C3 treatment also decreased AC3+ cell number but had no effect on total GCL volume in Ts65Dn mice. Our findings show 3 months of P7C3 is sufficient to restore the neurogenic deficits observed in the Ts65Dn mouse model of DS. PMID:25668489

  4. Chronic levodopa treatment alters expression and function of dopamine D3 receptor in the MPTP/p mouse model of Parkinson's disease.

    PubMed

    Cote, Samantha R; Kuzhikandathil, Eldo V

    2015-01-12

    Chronic treatment with levodopa or antipsychotics results in manifestation of side-effects such as dyskinesia which correlates with changes in expression and function of receptors and signaling proteins. Previous studies have suggested a role for the dopamine D3 receptor in Parkinson's disease (PD) and tardive dyskinesia. Yet the expression and signaling function of D3 receptor in these disorders is not well understood. Here we tested the hypothesis that chronic levodopa treatment alters both expression and function of D3 receptors in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine plus probenecid (MPTP/p) mouse model of PD. drd3-EGFP reporter mice were injected biweekly with saline or MPTP and probenecid for a 5-week period. During the last two weeks of the 5-week period, the mice were administered saline or levodopa twice daily. Locomotor activity was measured during the treatment period. D3 receptor expression was determined by western blot analysis. D3 receptor signaling function was determined at tissue and single cell level by measuring the activation of D3 receptor-mitogen activated protein kinase (MAPK) pathway. The drd3-EGFP mice administered MPTP/p exhibited akinesia/bradykinesia. Expression of D3 receptor protein in the dorsal striatum specifically increased in the MPTP/p-treated mice administered levodopa. In the dorsal striatum of levodopa and MPTP/p-treated drd3-EGFP mice, administration of a D3 receptor-selective dose of agonist, PD128907, failed to activate D3 receptor-MAPK signaling. These results suggest that MPTP-induced lesion and chronic levodopa treatment alters D3 receptor expression and function in the dorsal striatum which could contribute to the development of dyskinesias and other motor side-effects. PMID:25445374

  5. Hypoxic ventilatory drive in dogs during thiopental, ketamine, or pentobarbital anesthesia.

    PubMed

    Hirshman, C A; McCullough, R E; Cohen, P J; Weil, J V

    1975-12-01

    The ventilatory responses to isocapnic hypoxia and hypercapnia were studied in seven chronically tracheostomized dogs awake and during anesthesia with pentobarbital (30 mg/kg, iv), ketamine, or thiopental (10 and 15 mg/kg, respectively, followed by infusion). Isocapnic hypoxic ventilatory drive (HVD) was expressed as the parameter A such that the higher the A, the greater the hypoxic drive. HVD(A) was significantly reduced from 259 +/- 28 (mean +/- SEM) in awake dogs, to 96 +/- 14 after pentobarbital, 161 +/- 27 after thiopental, and 213 +/- 23 after ketamine. Hypercapnic ventilatory drive (HCVD) as measured by S (slope of the VE-PACO2 response curve) was significantly reduced from 1.3 +/- .32 in awake dogs to 0.4 +/- .13 after pentobarbital, 0.5 +/- .12 after thiopental, and 0.6 +/- .11 after ketamine. In addition, hypercapnia-induced augmentation of hypoxic drive was markedly diminished by the two barbiturates but was unaffected by ketamine. Therefore, ketamine at this dose level afforded greater protection during exposure to hypoxia than did barbiturates. (Key words: Ventilation, hypoxic response; Hypoxia, ventilation; Oxygen, ventilatory response; Carbon dioxide, ventilatory response; Anesthetics, intravenous, ketamine; Anesthetics, intravenous, thiopental; Hypnotics, barbiturates, pentobarbital.) PMID:1190538

  6. Important role of PLC-γ1 in hypoxic increase in intracellular calcium in pulmonary arterial smooth muscle cells.

    PubMed

    Yadav, Vishal R; Song, Tengyao; Joseph, Leroy; Mei, Lin; Zheng, Yun-Min; Wang, Yong-Xiao

    2013-02-01

    An increase in intracellular calcium concentration ([Ca(2+)](i)) in pulmonary arterial smooth muscle cells (PASMCs) induces hypoxic cellular responses in the lungs; however, the underlying molecular mechanisms remain incompletely understood. We report, for the first time, that acute hypoxia significantly enhances phospholipase C (PLC) activity in mouse resistance pulmonary arteries (PAs), but not in mesenteric arteries. Western blot analysis and immunofluorescence staining reveal the expression of PLC-γ1 protein in PAs and PASMCs, respectively. The activity of PLC-γ1 is also augmented in PASMCs following hypoxia. Lentiviral shRNA-mediated gene knockdown of mitochondrial complex III Rieske iron-sulfur protein (RISP) to inhibit reactive oxygen species (ROS) production prevents hypoxia from increasing PLC-γ1 activity in PASMCs. Myxothiazol, a mitochondrial complex III inhibitor, reduces the hypoxic response as well. The PLC inhibitor U73122, but not its inactive analog U73433, attenuates the hypoxic vasoconstriction in PAs and hypoxic increase in [Ca(2+)](i) in PASMCs. PLC-γ1 knockdown suppresses its protein expression and the hypoxic increase in [Ca(2+)](i). Hypoxia remarkably increases inositol 1,4,5-trisphosphate (IP(3)) production, which is blocked by U73122. The IP(3) receptor (IP(3)R) antagonist 2-aminoethoxydiphenyl borate (2-APB) or xestospongin-C inhibits the hypoxic increase in [Ca(2+)](i). PLC-γ1 knockdown or U73122 reduces H(2)O(2)-induced increase in [Ca(2+)](i) in PASMCs and contraction in PAs. 2-APB and xestospongin-C produce similar inhibitory effects. In conclusion, our findings provide novel evidence that hypoxia activates PLC-γ1 by increasing RISP-dependent mitochondrial ROS production in the complex III, which causes IP(3) production, IP(3)R opening, and Ca(2+) release, playing an important role in hypoxic Ca(2+) and contractile responses in PASMCs. PMID:23204067

  7. Performance of an active inspired hypoxic guard.

    PubMed

    Ghijselings, Idris E; De Cooman, Sofie; Carette, Rik; Peyton, Philip J; De Wolf, Andre M; Hendrickx, Jan F A

    2016-02-01

    Current hypoxic guards systems fail to maintain the inspired O2 concentration (FIO2) ≥ 21 % across the entire fresh gas flow (FGF) range when a second carrier gas is used (N2O or air). We examined the performance of the Maquet O2 Guard(®), a smart hypoxic guard that increases O2 delivery if an inspired hypoxic mixture is formed. After obtaining IRB approval and informed consent, 12 ASA I-II patients were enrolled. During anesthesia with sevoflurane in O2/air, the O2 Guard(®) was tested by administering O2/air at the following delivered hypoxic guard limits [expressed as (total FGF in L min(-1); FDO2 in %)] for 4 min each: [0.3;67], [0.4;50], [0.6;34], [0.8;25], [1.0;21], [1.2;21], [1.5;21], [2;21], [3;21], and [5;21]. The following data were collected: (1) time from FIO2 = 30 to 20 %; (2) time from FIO2 = 20 % to O2 Guard(®) activation; (3) time from O2 Guard(®) activation to FIO2 = 25 %; (4) FGF and FDO2 used by the O2 Guard. If SpO2 was <90 % for 10 s or longer at any time, the patient was excluded. Three patients were excluded for low SpO2. The incidence of FIO2 < 21 % was 100 % within the 1-2 L min(-1) FGF range. The O2 Guard(®) was activated within 20 s after FIO2 became 20 %, except in one patient where FIO2 oscillated between 20 and 21 %. FDO2 was increased to 60 % and FGF to 1 L min(-1) (the latter only if it was lower than 1 L min(-1) prior to activation of the O2 Guard). FIO2 increased to 25 % within 55 s after O2 Guard activation in all patients. The O2 Guard(®), an active inspired hypoxic guard, rapidly reverses and limits the duration of inspired hypoxic episodes when the delivered hypoxic guard fails to do so. PMID:25757405

  8. Combining hypoxic methods for peak performance.

    PubMed

    Millet, Gregoire P; Roels, B; Schmitt, L; Woorons, X; Richalet, J P

    2010-01-01

    New methods and devices for pursuing performance enhancement through altitude training were developed in Scandinavia and the USA in the early 1990s. At present, several forms of hypoxic training and/or altitude exposure exist: traditional 'live high-train high' (LHTH), contemporary 'live high-train low' (LHTL), intermittent hypoxic exposure during rest (IHE) and intermittent hypoxic exposure during continuous session (IHT). Although substantial differences exist between these methods of hypoxic training and/or exposure, all have the same goal: to induce an improvement in athletic performance at sea level. They are also used for preparation for competition at altitude and/or for the acclimatization of mountaineers. The underlying mechanisms behind the effects of hypoxic training are widely debated. Although the popular view is that altitude training may lead to an increase in haematological capacity, this may not be the main, or the only, factor involved in the improvement of performance. Other central (such as ventilatory, haemodynamic or neural adaptation) or peripheral (such as muscle buffering capacity or economy) factors play an important role. LHTL was shown to be an efficient method. The optimal altitude for living high has been defined as being 2200-2500 m to provide an optimal erythropoietic effect and up to 3100 m for non-haematological parameters. The optimal duration at altitude appears to be 4 weeks for inducing accelerated erythropoiesis whereas <3 weeks (i.e. 18 days) are long enough for beneficial changes in economy, muscle buffering capacity, the hypoxic ventilatory response or Na(+)/K(+)-ATPase activity. One critical point is the daily dose of altitude. A natural altitude of 2500 m for 20-22 h/day (in fact, travelling down to the valley only for training) appears sufficient to increase erythropoiesis and improve sea-level performance. 'Longer is better' as regards haematological changes since additional benefits have been shown as hypoxic exposure

  9. Acute and Chronic Plasma Metabolomic and Liver Transcriptomic Stress Effects in a Mouse Model with Features of Post-Traumatic Stress Disorder

    PubMed Central

    Gautam, Aarti; D’Arpa, Peter; Donohue, Duncan E.; Muhie, Seid; Chakraborty, Nabarun; Luke, Brian T.; Grapov, Dmitry; Carroll, Erica E.; Meyerhoff, James L.; Hammamieh, Rasha; Jett, Marti

    2015-01-01

    Acute responses to intense stressors can give rise to post-traumatic stress disorder (PTSD). PTSD diagnostic criteria include trauma exposure history and self-reported symptoms. Individuals who meet PTSD diagnostic criteria often meet criteria for additional psychiatric diagnoses. Biomarkers promise to contribute to reliable phenotypes of PTSD and comorbidities by linking biological system alterations to behavioral symptoms. Here we have analyzed unbiased plasma metabolomics and other stress effects in a mouse model with behavioral features of PTSD. In this model, C57BL/6 mice are repeatedly exposed to a trained aggressor mouse (albino SJL) using a modified, resident-intruder, social defeat paradigm. Our recent studies using this model found that aggressor-exposed mice exhibited acute stress effects including changed behaviors, body weight gain, increased body temperature, as well as inflammatory and fibrotic histopathologies and transcriptomic changes of heart tissue. Some of these acute stress effects persisted, reminiscent of PTSD. Here we report elevated proteins in plasma that function in inflammation and responses to oxidative stress and damaged tissue at 24 hrs post-stressor. Additionally at this acute time point, transcriptomic analysis indicated liver inflammation. The unbiased metabolomics analysis showed altered metabolites in plasma at 24 hrs that only partially normalized toward control levels after stress-withdrawal for 1.5 or 4 wks. In particular, gut-derived metabolites were altered at 24 hrs post-stressor and remained altered up to 4 wks after stress-withdrawal. Also at the 4 wk time point, hyperlipidemia and suppressed metabolites of amino acids and carbohydrates in plasma coincided with transcriptomic indicators of altered liver metabolism (activated xenobiotic and lipid metabolism). Collectively, these system-wide sequelae to repeated intense stress suggest that the simultaneous perturbed functioning of multiple organ systems (e.g., brain, heart

  10. A mouse model of heart failure with preserved ejection fraction due to chronic infusion of a low subpressor dose of angiotensin II

    PubMed Central

    Regan, Jessica A.; Mauro, Adolfo Gabriele; Carbone, Salvatore; Marchetti, Carlo; Gill, Rabia; Mezzaroma, Eleonora; Valle Raleigh, Juan; Salloum, Fadi N.; Van Tassell, Benjamin W.; Abbate, Antonio

    2015-01-01

    Heart failure (HF) with preserved ejection fraction (HFpEF) is a clinical syndrome of HF symptoms associated with impaired diastolic function. Although it represents ∼50% of patients with HF, the mechanisms of disease are poorly understood, and therapies are generally ineffective in reducing HF progression. Animal models of HFpEF not due to pressure or volume overload are lacking, therefore limiting in-depth understanding of the pathophysiological mechanisms and the development of novel therapies. We hypothesize that a continuous infusion of low-dose angiotensin II (ATII) is sufficient to induce left ventricular (LV) diastolic dysfunction and HFpEF, without increasing blood pressure or inducing LV hypertrophy or dilatation. Osmotic pumps were implanted subcutaneously in 8-wk-old male mice assigned to the ATII (0.2 mg·kg−1·day−1) or volume-matched vehicle (N = 8/group) for 4 wk. We measured systolic and diastolic arterial blood pressures through a tail-cuff transducer, LV dimensions and ejection fraction through echocardiography, and LV relaxation through pulsed-wave Doppler and LV catheterization. Myocardial fibrosis and cardiomyocyte cross-sectional area were measured. ATII infusion had no effects on systemic arterial blood pressure. ATII induced significant impairment in LV diastolic function, as measured by an increase (worsening) in LV isovolumetric relaxation time, myocardial performance index, isovolumetric relaxation time constant, and LV end-diastolic pressure without altering LV dimensions, mass, or ejection fraction. Chronic infusion of low-dose ATII recapitulates the HFpEF phenotype in the mouse, without increasing systemic arterial blood pressure. This mouse model may provide insight into the mechanisms of HFpEF. PMID:26188021

  11. A mouse model of heart failure with preserved ejection fraction due to chronic infusion of a low subpressor dose of angiotensin II.

    PubMed

    Regan, Jessica A; Mauro, Adolfo Gabriele; Carbone, Salvatore; Marchetti, Carlo; Gill, Rabia; Mezzaroma, Eleonora; Valle Raleigh, Juan; Salloum, Fadi N; Van Tassell, Benjamin W; Abbate, Antonio; Toldo, Stefano

    2015-09-01

    Heart failure (HF) with preserved ejection fraction (HFpEF) is a clinical syndrome of HF symptoms associated with impaired diastolic function. Although it represents ∼50% of patients with HF, the mechanisms of disease are poorly understood, and therapies are generally ineffective in reducing HF progression. Animal models of HFpEF not due to pressure or volume overload are lacking, therefore limiting in-depth understanding of the pathophysiological mechanisms and the development of novel therapies. We hypothesize that a continuous infusion of low-dose angiotensin II (ATII) is sufficient to induce left ventricular (LV) diastolic dysfunction and HFpEF, without increasing blood pressure or inducing LV hypertrophy or dilatation. Osmotic pumps were implanted subcutaneously in 8-wk-old male mice assigned to the ATII (0.2 mg·kg(-1)·day(-1)) or volume-matched vehicle (N = 8/group) for 4 wk. We measured systolic and diastolic arterial blood pressures through a tail-cuff transducer, LV dimensions and ejection fraction through echocardiography, and LV relaxation through pulsed-wave Doppler and LV catheterization. Myocardial fibrosis and cardiomyocyte cross-sectional area were measured. ATII infusion had no effects on systemic arterial blood pressure. ATII induced significant impairment in LV diastolic function, as measured by an increase (worsening) in LV isovolumetric relaxation time, myocardial performance index, isovolumetric relaxation time constant, and LV end-diastolic pressure without altering LV dimensions, mass, or ejection fraction. Chronic infusion of low-dose ATII recapitulates the HFpEF phenotype in the mouse, without increasing systemic arterial blood pressure. This mouse model may provide insight into the mechanisms of HFpEF. PMID:26188021

  12. Accelerated tau aggregation, apoptosis and neurological dysfunction caused by chronic oral administration of aluminum in a mouse model of tauopathies.

    PubMed

    Oshima, Etsuko; Ishihara, Takeshi; Yokota, Osamu; Nakashima-Yasuda, Hanae; Nagao, Shigeto; Ikeda, Chikako; Naohara, Jun; Terada, Seishi; Uchitomi, Yosuke

    2013-11-01

    To clarify whether long-term oral ingestion of aluminum (Al) can increase tau aggregation in mammals, we examined the effects of oral Al administration on tau accumulation, apoptosis in the central nervous system (CNS) and motor function using tau transgenic (Tg) mice that show very slowly progressive tau accumulation. Al-treated tau Tg mice had almost twice as many tau-positive inclusions in the spinal cord as tau Tg mice without Al treatment at 12 months of age, a difference that reached statistical significance, and the development of pretangle-like tau aggregates in the brain was also significantly advanced from 9 months. Al exposure did not induce any tau pathology in wild-type (WT) mice. Apoptosis was observed in the hippocampus in Al-treated tau Tg mice, but was virtually absent in the other experimental groups. Motor function as assessed by the tail suspension test was most severely impaired in Al-treated tau Tg mice. Given our results, chronic oral ingestion of Al may more strongly promote tau aggregation, apoptosis and neurological dysfunction if individuals already had a pathological process causing tau aggregation. These findings may also implicate chronic Al neurotoxicity in humans, who frequently have had mild tau pathology from a young age. PMID:23574527

  13. Restoration of Haemoglobin Level Using Hydrodynamic Gene Therapy with Erythropoietin Does Not Alleviate the Disease Progression in an Anaemic Mouse Model for TGFβ1-Induced Chronic Kidney Disease

    PubMed Central

    Pedersen, Lea; Wogensen, Lise; Marcussen, Niels; Cecchi, Claudia R.; Dalsgaard, Trine; Dagnæs-Hansen, Frederik

    2015-01-01

    Erythropoietin, Epo, is a 30.4 kDa glycoprotein hormone produced primarily by the fetal liver and the adult kidney. Epo exerts its haematopoietic effects by stimulating the proliferation and differentiation of erythrocytes with subsequent improved tissue oxygenation. Epo receptors are furthermore expressed in non-haematopoietic tissue and today, Epo is recognised as a cytokine with many pleiotropic effects. We hypothesize that hydrodynamic gene therapy with Epo can restore haemoglobin levels in anaemic transgenic mice and that this will attenuate the extracellular matrix accumulation in the kidneys. The experiment is conducted by hydrodynamic gene transfer of a plasmid encoding murine Epo in a transgenic mouse model that overexpresses TGF-β1 locally in the kidneys. This model develops anaemia due to chronic kidney disease characterised by thickening of the glomerular basement membrane, deposition of mesangial matrix and mild interstitial fibrosis. A group of age matched wildtype littermates are treated accordingly. After a single hydrodynamic administration of plasmid DNA containing murine EPO gene, sustained high haemoglobin levels are observed in both transgenic and wildtype mice from 7.5 ± 0.6 mmol/L to 9.4 ± 1.2 mmol/L and 10.7 ± 0.3 mmol/L to 15.5 ± 0.5 mmol/L, respectively. We did not observe any effects in the thickness of glomerular or tubular basement membrane, on the expression of different collagen types in the kidneys or in kidney function after prolonged treatment with Epo. Thus, Epo treatment in this model of chronic kidney disease normalises haemoglobin levels but has no effect on kidney fibrosis or function. PMID:26046536

  14. Persistent cyclooxygenase-2 inhibition downregulates NF-{kappa}B, resulting in chronic intestinal inflammation in the min/+ mouse model of colon tumorigenesis.

    PubMed

    Carothers, Adelaide M; Davids, Jennifer S; Damas, Beatrice C; Bertagnolli, Monica M

    2010-06-01

    Cyclooxygenase-2 (COX-2) inhibition prevents adenoma formation in humans and mouse models of colon cancer. The selective COX-2 inhibitor celecoxib reduces COX-2 and prostaglandin E(2) (PGE(2)) expression and adenomas in the intestine of Min/+ mice after treatment for several weeks, but prolonged treatment increases PGE(2) production, resulting in drug-resistant tumor formation and transforming growth factor beta (TGFbeta)-dependent intestinal fibrosis. In this study, we examined pathways that regulate COX-2 expression and suppress chronic intestinal inflammation. We show that NF-kappaB signaling was inhibited in the ileum of Min/+ mice receiving long-term treatment with celecoxib. This effect was associated with inhibition of TGFbeta-associated kinase-1 and IkappaB kinase alpha/beta activities and reduced expression of the Toll-like receptor (TLR) 2 and TLR4 that enhance colonic barrier function. Additionally, we observed reduced activities of protein kinases c-Jun NH(2)-terminal kinase 1 and protein kinase A and transcription factor cyclic AMP-responsive element binding protein, regulators of COX-2 expression, which cross-talk with NF-kappaB. In ileum subjected to long-term celecoxib treatment, we noted relatively higher expression of COX-2, vascular endothelial growth factor, and interleukin-1beta in Paneth cells, whereas NF-kappaB and COX-2 were more strongly expressed by an expanded population of stromal myofibroblasts. Our findings argue that celecoxib resistance is an acquired adaptation to changes in the crypt microenvironment that is associated with chronic intestinal inflammation and impaired acute wound-healing responsiveness. PMID:20484034

  15. Chronic Exposure to Androgenic-Anabolic Steroids Exacerbates Axonal Injury and Microgliosis in the CHIMERA Mouse Model of Repetitive Concussion.

    PubMed

    Namjoshi, Dhananjay R; Cheng, Wai Hang; Carr, Michael; Martens, Kris M; Zareyan, Shahab; Wilkinson, Anna; McInnes, Kurt A; Cripton, Peter A; Wellington, Cheryl L

    2016-01-01

    Concussion is a serious health concern. Concussion in athletes is of particular interest with respect to the relationship of concussion exposure to risk of chronic traumatic encephalopathy (CTE), a neurodegenerative condition associated with altered cognitive and psychiatric functions and profound tauopathy. However, much remains to be learned about factors other than cumulative exposure that could influence concussion pathogenesis. Approximately 20% of CTE cases report a history of substance use including androgenic-anabolic steroids (AAS). How acute, chronic, or historical AAS use may affect the vulnerability of the brain to concussion is unknown. We therefore tested whether antecedent AAS exposure in young, male C57Bl/6 mice affects acute behavioral and neuropathological responses to mild traumatic brain injury (TBI) induced with the CHIMERA (Closed Head Impact Model of Engineered Rotational Acceleration) platform. Male C57Bl/6 mice received either vehicle or a cocktail of three AAS (testosterone, nandrolone and 17α-methyltestosterone) from 8-16 weeks of age. At the end of the 7th week of treatment, mice underwent two closed-head TBI or sham procedures spaced 24 h apart using CHIMERA. Post-repetitive TBI (rTBI) behavior was assessed for 7 d followed by tissue collection. AAS treatment induced the expected physiological changes including increased body weight, testicular atrophy, aggression and downregulation of brain 5-HT1B receptor expression. rTBI induced behavioral deficits, widespread axonal injury and white matter microgliosis. While AAS treatment did not worsen post-rTBI behavioral changes, AAS-treated mice exhibited significantly exacerbated axonal injury and microgliosis, indicating that AAS exposure can alter neuronal and innate immune responses to concussive TBI. PMID:26784694

  16. Effects of Chronic Scopolamine Treatment on Cognitive Impairments and Myelin Basic Protein Expression in the Mouse Hippocampus.

    PubMed

    Park, Joon Ha; Choi, Hyun Young; Cho, Jeong-Hwi; Kim, In Hye; Lee, Tae-Kyeong; Lee, Jae-Chul; Won, Moo-Ho; Chen, Bai Hui; Shin, Bich-Na; Ahn, Ji Hyeon; Tae, Hyun-Jin; Choi, Jung Hoon; Chung, Jin-Young; Lee, Choong-Hyun; Cho, Jun Hwi; Kang, Il Jun; Kim, Jong-Dai

    2016-08-01

    Myelin plays an important role in learning and memory, and degradation of myelin is a key feature in the pathogenesis of neurological disorders involving cognitive dysfunction. Myelin basic protein (MBP) is one of the most abundant structural proteins in myelin and is essential for myelin formation and compaction. In this study, we first examined changes in the distribution of MBP-immunoreactive myelinated fibers and MBP levels according to hippocampal subregion in mice following chronic systemic treatment with 1 mg/kg scopolamine (SCO) for 4 weeks. We found that SCO-induced cognitive impairments, as assayed by the water maze and passive avoidance tests, were significantly reduced 1 week after SCO treatment and the impairments were maintained without any hippocampal neuronal loss. MBP-immunoreactive myelinated fibers were easily detected in the stratum radiatum and lacunosum-moleculare of the hippocampus proper (CA1-3 region) and in the molecular and polymorphic layers of the dentate gyrus. The distribution of MBP-immunoreactive myelinated fibers was not altered 1 week after SCO treatment. However, the density of MBP-immunoreactive myelinated fibers was significantly decreased 2 weeks after SCO treatment; thereafter, the density gradually, though not significantly, decreased with time. In addition, the changing pattern of MBP levels in the hippocampus following SCO treatment corresponded to immunohistochemical changes. In brief, this study shows that chronic systemic treatment with SCO induced significant degradation of MBP in the hippocampus without neuronal loss at least 2 weeks after SCO treatment, although cognitive impairments occurred 1 week after SCO treatment. PMID:27343058

  17. The pathophysiology underlying repetitive mild traumatic brain injury in a novel mouse model of chronic traumatic encephalopathy

    PubMed Central

    Petraglia, Anthony L.; Plog, Benjamin A.; Dayawansa, Samantha; Dashnaw, Matthew L.; Czerniecka, Katarzyna; Walker, Corey T.; Chen, Michael; Hyrien, Ollivier; Iliff, Jeffrey J.; Deane, Rashid; Huang, Jason H.; Nedergaard, Maiken

    2014-01-01

    Background: An animal model of chronic traumatic encephalopathy (CTE) is essential for further understanding the pathophysiological link between repetitive head injury and the development of chronic neurodegenerative disease. We previously described a model of repetitive mild traumatic brain injury (mTBI) in mice that encapsulates the neurobehavioral spectrum characteristic of patients with CTE. We aimed to study the pathophysiological mechanisms underlying this animal model. Methods: Our previously described model allows for controlled, closed head impacts to unanesthetized mice. Briefly, 12-week-old mice were divided into three groups: Control, single, and repetitive mTBI. Repetitive mTBI mice received six concussive impacts daily, for 7 days. Mice were then subsequently sacrificed for macro- and micro-histopathologic analysis at 7 days, 1 month, and 6 months after the last TBI received. Brain sections were immunostained for glial fibrillary acidic protein (GFAP) for astrocytes, CD68 for activated microglia, and AT8 for phosphorylated tau protein. Results: Brains from single and repetitive mTBI mice lacked macroscopic tissue damage at all time-points. Single mTBI resulted in an acute rea ctive astrocytosis at 7 days and increased phospho-tau immunoreactivity that was present acutely and at 1 month, but was not persistent at 6 months. Repetitive mTBI resulted in a more marked neuroinflammatory response, with persistent and widespread astrogliosis and microglial activation, as well as significantly elevated phospho-tau immunoreactivity to 6-months. Conclusions: The neuropathological findings in this new model of repetitive mTBI resemble some of the histopathological hallmarks of CTE, including increased astrogliosis, microglial activation, and hyperphosphorylated tau protein accumulation. PMID:25593768

  18. Chronic Exposure to Androgenic-Anabolic Steroids Exacerbates Axonal Injury and Microgliosis in the CHIMERA Mouse Model of Repetitive Concussion

    PubMed Central

    Namjoshi, Dhananjay R.; Cheng, Wai Hang; Carr, Michael; Martens, Kris M.; Zareyan, Shahab; Wilkinson, Anna; McInnes, Kurt A.; Cripton, Peter A.; Wellington, Cheryl L.

    2016-01-01

    Concussion is a serious health concern. Concussion in athletes is of particular interest with respect to the relationship of concussion exposure to risk of chronic traumatic encephalopathy (CTE), a neurodegenerative condition associated with altered cognitive and psychiatric functions and profound tauopathy. However, much remains to be learned about factors other than cumulative exposure that could influence concussion pathogenesis. Approximately 20% of CTE cases report a history of substance use including androgenic-anabolic steroids (AAS). How acute, chronic, or historical AAS use may affect the vulnerability of the brain to concussion is unknown. We therefore tested whether antecedent AAS exposure in young, male C57Bl/6 mice affects acute behavioral and neuropathological responses to mild traumatic brain injury (TBI) induced with the CHIMERA (Closed Head Impact Model of Engineered Rotational Acceleration) platform. Male C57Bl/6 mice received either vehicle or a cocktail of three AAS (testosterone, nandrolone and 17α-methyltestosterone) from 8–16 weeks of age. At the end of the 7th week of treatment, mice underwent two closed-head TBI or sham procedures spaced 24 h apart using CHIMERA. Post-repetitive TBI (rTBI) behavior was assessed for 7 d followed by tissue collection. AAS treatment induced the expected physiological changes including increased body weight, testicular atrophy, aggression and downregulation of brain 5-HT1B receptor expression. rTBI induced behavioral deficits, widespread axonal injury and white matter microgliosis. While AAS treatment did not worsen post-rTBI behavioral changes, AAS-treated mice exhibited significantly exacerbated axonal injury and microgliosis, indicating that AAS exposure can alter neuronal and innate immune responses to concussive TBI. PMID:26784694

  19. Chronic anabolic androgenic steroid exposure alters corticotropin releasing factor expression and anxiety-like behaviors in the female mouse.

    PubMed

    Costine, Beth A; Oberlander, Joseph G; Davis, Matthew C; Penatti, Carlos A A; Porter, Donna M; Leaton, Robert N; Henderson, Leslie P

    2010-11-01

    In the past several decades, the therapeutic use of anabolic androgenic steroids (AAS) has been overshadowed by illicit use of these drugs by elite athletes and a growing number of adolescents to enhance performance and body image. As with adults, AAS use by adolescents is associated with a range of behavioral effects, including increased anxiety and altered responses to stress. It has been suggested that adolescents, especially adolescent females, may be particularly susceptible to the effects of these steroids, but few experiments in animal models have been performed to test this assertion. Here we show that chronic exposure of adolescent female mice to a mixture of three commonly abused AAS (testosterone cypionate, nandrolone decanoate and methandrostenolone; 7.5 mg/kg/day for 5 days) significantly enhanced anxiety-like behavior as assessed by the acoustic startle response (ASR), but did not augment the fear-potentiated startle response (FPS) or alter sensorimotor gating as assessed by prepulse inhibition of the acoustic startle response (PPI). AAS treatment also significantly increased the levels of corticotropin releasing factor (CRF) mRNA and somal-associated CRF immunoreactivity in the central nucleus of the amygdala (CeA), as well as neuropil-associated immunoreactivity in the dorsal aspect of the anterolateral division of the bed nucleus of the stria terminalis (dBnST). AAS treatment did not alter CRF receptor 1 or 2 mRNA in either the CeA or the dBnST; CRF immunoreactivity in the ventral BnST, the paraventricular nucleus (PVN) or the median eminence (ME); or peripheral levels of corticosterone. These results suggest that chronic AAS treatment of adolescent female mice may enhance generalized anxiety, but not sensorimotor gating or learned fear, via a mechanism that involves increased CRF-mediated signaling from CeA neurons projecting to the dBnST. PMID:20537804

  20. Chronic Anabolic Androgenic Steroid Exposure Alters Corticotropin Releasing Factor Expression and Anxiety-Like Behaviors in the Female Mouse

    PubMed Central

    Costine, Beth A; Oberlander, Joseph G; Davis, Matthew C; Penatti, Carlos A A; Porter, Donna M; Leaton, Robert N; Henderson, Leslie P

    2010-01-01

    Summary In the past several decades, the therapeutic use of anabolic androgenic steroids (AAS) has been overshadowed by illicit use of these drugs by elite athletes and a growing number of adolescents to enhance performance and body image. As with adults, AAS use by adolescents is associated with a range of behavioral effects, including increased anxiety and altered responses to stress. It has been suggested that adolescents, especially adolescent females, may be particularly susceptible to the effects of these steroids, but few experiments in animal models have been performed to test this assertion. Here we show that chronic exposure of adolescent female mice to a mixture of three commonly abused AAS (testosterone cypionate, nandrolone decanoate and methandrostenolone; 7.5 mg/kg/day for 5 days) significantly enhanced anxiety-like behavior as assessed by the acoustic startle response (ASR), but did not augment the fear-potentiated startle response (FPS) or alter sensorimotor gating as assessed by prepulse inhibition of the acoustic startle response (PPI). AAS treatment also significantly increased the levels of corticotropin releasing factor (CRF) mRNA and somal-associated CRF immunoreactivity in the central amygdala (CeA), as well as neuropil-associated immunoreactivity in the dorsal aspect of the anterolateral division of the bed nucleus of the stria terminalis (dBnST). AAS treatment did not alter CRF receptor 1 or 2 mRNA in either the CeA or the dBnST; CRF immunoreactivity in the ventral BNST, the paraventricular nucleus (PVN) or the median eminence (ME); or peripheral levels of corticosterone. These results suggest that chronic AAS treatment of adolescent female mice may enhance generalized anxiety, but not sensorimotor gating or learned fear, via a mechanism that involves increased CRF-mediated signaling from CeA neurons projecting to the dBnST. PMID:20537804

  1. Antidepressant-like effects of Sanyuansan in the mouse forced swim test, tail suspension test, and chronic mild stress model.

    PubMed

    Yan, Shuo; You, Zi-Li; Zhao, Qiu-Ying; Peng, Cheng; He, Gang; Gou, Xiao-Jun; Lin, Bin

    2015-12-01

    Natural products have been widely reported as effective therapeutic alternatives for treatment of depression. Sanyuansan is a compound recipe composed of ginseng total saponins, fish oil, and valeriana. The aims of this study were to validate whether Sanyuansan has antidepressant-like effects through acute behavioral tests including the forced swimming test (FST), tail suspension test (TST), locomotor activity test, and chronic mild stress (CMS) mice model of depression. C57BL/6 mice were given oral administration of 30 mg/kg imipramine, Sanyuansan, and saline, respectively. The acute behavioral tests including the TST, FST, and locomotor activity test were done after the administration of drugs for consecutively three times (24 hours, 1 hour, and 0.5 hour prior to the tests). Furthermore, the sucrose preference and the serum corticosterone level of mice in the CMS model were examined. Sanyuansan only at 900 mg/kg markedly reduced immobility time in the TST compared with the saline-treated group of mice. Sanyuansan at doses of 225 mg/kg, 450 mg/kg, and 900 mg/kg significantly reduced immobility time of mice in the FST. Sanyuansan reversed the CMS-induced anhedonia and hyperactivation of the hypothalamus-pituitary-adrenal axis. In addition, our results showed that neither imipramine nor Sanyuansan at any dosage increased spontaneous motor activity. These results suggested that Sanyuansan induced significant antidepressant-like effects in mice in both acute and chronic animal models, which seemed unlikely to be attributed to an increase in locomotor activities of mice, and had no sedative-like effects. PMID:26709221

  2. Chronic increase of urea leads to carbamylated proteins accumulation in tissues in a mouse model of CKD.

    PubMed

    Pietrement, Christine; Gorisse, Laëtitia; Jaisson, Stéphane; Gillery, Philippe

    2013-01-01

    Carbamylation is a general process involved in protein molecular ageing due to the nonenzymatic binding of isocyanic acid, mainly generated by urea dissociation, to free amino groups. In vitro experiments and clinical studies have suggested the potential involvement of carbamylated proteins (CPs) in chronic kidney disease (CKD) complications like atherosclerosis, but their metabolic fate in vivo is still unknown. To address this issue, we evaluated protein carbamylation in the plasma and tissues of control and 75% nephrectomised C57BL/6J mice by LC-MS/MS assay of homocitrulline, the major carbamylation-derived product (CDP). A basal level of carbamylation was evidenced under all conditions, showing that carbamylation is a physiological process of protein modification in vivo. CP plasma concentrations increased in nephrectomized vs. control mice over the 20 weeks of the experiment (e.g. 335 ± 43 vs. 167 ± 19 μmol homocitrulline/mol lysine (p<0.001) 20 weeks after nephrectomy). Simultaneously, CP content increased roughly by two-fold in all tissues throughout the experiment. The progressive accumulation of CPs was specifically noted in long-lived extracellular matrix proteins, especially collagen (e.g. 1264 ± 123 vs. 726 ± 99 μmol homocitrulline/mol lysine (p<0.01) in the skin of nephrectomized vs. control mice after 20 weeks of evolution). These results show that chronic increase of urea, as seen in CKD, increases the carbamylation rate of plasma and tissue proteins. These results may be considered in the perspective of the deleterious effects of CPs demonstrated in vitro and of the correlation evidenced recently between plasma CPs and cardiovascular risk or mortality in CKD patients. PMID:24324801

  3. Lactobacillus rhamnosus CCFM1107 treatment ameliorates alcohol-induced liver injury in a mouse model of chronic alcohol feeding.

    PubMed

    Tian, Fengwei; Chi, Feifei; Wang, Gang; Liu, Xiaoming; Zhang, Qiuxiang; Chen, Yongquan; Zhang, Hao; Chen, Wei

    2015-12-01

    Lactobacillus rhamnosus CCFM1107 was screened for high antioxidative activity from 55 lactobacilli. The present study attempted to explore the protective properties of L. rhamnosus CCFM1107 in alcoholic liver injury. A mouse model was induced by orally feeding alcohol when simultaneously treated with L. rhamnosus CCFM1107, the drug Hu-Gan- Pian (HGP), L. rhamnosus GG (LGG), and L. plantarum CCFM1112 for 3 months. Biochemical analysis was performed for both serum and liver homogenate. Detailed intestinal flora and histological analyses were also carried out. Our results indicated that the administration of L. rhamnosus CCFM1107 significantly inhibited the increase in the levels of serum aminotransferase and endotoxin, as well as the levels of triglyceride (TG) and cholesterol (CHO) in the serum and in the liver. Glutathione (GSH), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were elevated while the levels of malondialdehyde (MDA) were decreased. The enteric dysbiosis caused by alcohol was restored by increasing the numbers of both lactobacilli and bifidobacteria and decreasing the numbers of both enterococci and enterobacter. Histological analysis confirmed the protective effect of L. rhamnosus CCFM1107. Compared with the other lactobacilli and to the drug Hu-Gan-Pian, there is a high chance that L. rhamnosus CCFM1107 provides protective effects on alcoholic liver injury by reducing oxidative stress and restoring the intestinal flora. PMID:26626356

  4. Extensive reproductive disruption, ovarian masculinization and aromatase suppression in Atlantic croaker in the northern Gulf of Mexico hypoxic zone

    PubMed Central

    Thomas, Peter; Rahman, Md. Saydur

    2012-01-01

    The long-term impacts on marine ecosystems of the recent dramatic worldwide increase in the incidence of coastal hypoxia are unknown. Here, we show widespread reproductive disruption in Atlantic croakers collected from hypoxic sites approximately 120 km apart in the extensive northern Gulf of Mexico continental shelf hypoxic zone. Gonadal growth and gamete production were impaired in croakers from hypoxic sites compared with fish from reference normoxic sites east of the Mississippi River Delta. Male germ cells were detected in approximately 19 per cent of croaker ovaries collected in the hypoxic region, but were absent in ovaries from normoxic sites. In addition, the sex ratio was skewed towards males at the hypoxic sites. The masculinization and other reproductive disruptions were associated with declines in neuroendocrine function, as well as ovarian and brain expression of aromatase (the enzyme that converts androgens to oestrogens). A similar incidence of ovarian masculinization and decline in ovarian aromatase expression were observed in croaker after chronic laboratory hypoxia exposure, indicating that ovarian masculinization is a specific hypoxia response and is due to decreased aromatase activity. The results suggest severe reproductive impairment can occur over large coastal regions in marine fish populations exposed to seasonal hypoxia, with potential long-term impacts on population abundance. PMID:21613294

  5. Hypoxic Ischemic Encephalopathy: Pathophysiology and Experimental Treatments

    PubMed Central

    Allen, Kimberly A.; Brandon, Debra H.

    2011-01-01

    Hypoxic ischemic encephalopathy (HIE) is a serious birth complication affecting full term infants: 40–60% of affected infants die by 2 years of age or have severe disabilities. The majority of the underlying pathologic events of HIE are a result of impaired cerebral blood flow and oxygen delivery to the brain with resulting primary and secondary energy failure. In the past, treatment options were limited to supportive medical therapy. Currently, several experimental treatments are being explored in neonates and animal models to ameliorate the effects of secondary energy failure. This review discusses the underlying pathophysiologic effects of a hypoxic-ischemic event and experimental treatment modalities being explored to manage infants with HIE. Further research is needed to better understand if the long-term impact of the experimental treatments and whether the combinations of experimental treatments can improve outcomes in infants with HIE. PMID:21927583

  6. Activation of radiosensitizers by hypoxic cells.

    PubMed Central

    Olive, P. L.; Durand, R. E.

    1978-01-01

    Hypoxic cells can metabolize nitroheterocyclic compounds to produce toxic intermediates capable of affecting the survival of neighbouring oxygenated cells. Mutagenesis experiments with E. coli WP-2 343 (deficient in nitroreductase) indicated that reduction of nitroheterocyclics outside bacteria causes killing and mutations within bacteria, presumably due to the transfer of the "active" specie (s). Using animal tissue slices to reduce nitrofurans, cultured L-929 cells incubated under aerobic conditions were far more sensitive to the toxic and DNA damaging effects of these drugs. Transfer of the active species also occurs in a tissue-like environment in multicell spheroids where the presence of a hypoxic central core served to convert the nitroheterocyclics to intermediates which also damaged the neighbouring oxygenated cells. PMID:354676

  7. A novel dual GLP-1 and GIP incretin receptor agonist is neuroprotective in a mouse model of Parkinson's disease by reducing chronic inflammation in the brain.

    PubMed

    Cao, Lijun; Li, Dongfang; Feng, Peng; Li, Lin; Xue, Guo-Fang; Li, Guanglai; Hölscher, Christian

    2016-04-13

    The incretins glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are growth factors. GLP-1 mimetics are on the market as treatments for type 2 diabetes. Both GLP-1 and GIP mimetics have shown neuroprotective properties in previous studies. In addition, the GLP-1 mimetic exendin-4 has shown protective effects in a clinical trial in Parkinson's disease (PD) patients. Novel GLP-1/GIP dual-agonist peptides have been developed to treat diabetes. Here, we report the neuroprotective effects of a novel dual agonist (DA-JC1) in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. MPTP was injected once daily (20 mg/kg intraperitoneally) for 7 days and the dual agonist was coinjected once daily (50 nmol/kg intraperitoneally). We found that the drug reduced most of the MPTP-induced motor impairments in the rotarod, open-field locomotion, and muscle strength test. The number of tyrosine hydroxylase-positive neurons in the substantia nigra and striatum was reduced by MPTP and increased by DA-JC1. Synapse numbers (synaptophysin expression) were reduced in the substantia nigra and the striatum by MPTP and DA-JC1 reversed this effect. The activation of a chronic inflammation response by MPTP was considerably reduced by the dual agonist (DA) (astroglia and microglia activation). Therefore, dual agonists show promise as a novel treatment of PD. PMID:26918675

  8. The Grey Mouse Lemur Uses Season-Dependent Fat or Protein Sparing Strategies to Face Chronic Food Restriction

    PubMed Central

    Giroud, Sylvain; Perret, Martine; Stein, Peter; Goudable, Joëlle; Aujard, Fabienne; Gilbert, Caroline; Robin, Jean Patrice; Le Maho, Yvon; Zahariev, Alexandre

    2010-01-01

    During moderate calorie restriction (CR) the heterotherm Microcebus murinus is able to maintain a stable energy balance whatever the season, even if only wintering animals enter into torpor. To understand its energy saving strategies to respond to food shortages, we assessed protein and energy metabolisms associated with wintering torpor expression or summering torpor avoidance. We investigated body composition, whole body protein turnover, and daily energy expenditure (DEE), during a graded (40 and 80%) 35-day CR in short-days (winter; SD40 and SD80, respectively) and long-days (summer; LD40 and LD80, respectively) acclimated animals. LD40 animals showed no change in fat mass (FM) but a 12% fat free mass (FFM) reduction. Protein balance being positive after CR, the FFM loss was early and rapid. The 25% DEE reduction, in LD40 group was mainly explained by FFM changes. LD80 animals showed a steady body mass loss and were excluded from the CR trial at day 22, reaching a survival-threatened body mass. No data were available for this group. SD40 animals significantly decreased their FM level by 21%, but maintained FFM. Protein sparing was achieved through a 35 and 39% decrease in protein synthesis and catabolism (protein turnover), respectively, overall maintaining nitrogen balance. The 21% reduction in energy requirement was explained by the 30% nitrogen flux drop but also by torpor as DEE FFM-adjusted remained 13% lower compared to ad-libitum. SD80 animals were unable to maintain energy and nitrogen balances, losing both FM and FFM. Thus summering mouse lemurs equilibrate energy balance by a rapid loss of active metabolic mass without using torpor, whereas wintering animals spare protein and energy through increased torpor expression. Both strategies have direct fitness implication: 1) to maintain activities at a lower body size during the mating season and 2) to preserve an optimal wintering muscle mass and function. PMID:20098678

  9. Sub-Chronic Neuropathological and Biochemical Changes in Mouse Visual System after Repetitive Mild Traumatic Brain Injury.

    PubMed

    Tzekov, Radouil; Dawson, Clint; Orlando, Megan; Mouzon, Benoit; Reed, Jon; Evans, James; Crynen, Gogce; Mullan, Michael; Crawford, Fiona

    2016-01-01

    Repetitive mild traumatic brain injury (r-mTBI) results in neuropathological and biochemical consequences in the human visual system. Using a recently developed mouse model of r-mTBI, with control mice receiving repetitive anesthesia alone (r-sham) we assessed the effects on the retina and optic nerve using histology, immunohistochemistry, proteomic and lipidomic analyses at 3 weeks post injury. Retina tissue was used to determine retinal ganglion cell (RGC) number, while optic nerve tissue was examined for cellularity, myelin content, protein and lipid changes. Increased cellularity and areas of demyelination were clearly detectable in optic nerves in r-mTBI, but not in r-sham. These changes were accompanied by a ~25% decrease in the total number of Brn3a-positive RGCs. Proteomic analysis of the optic nerves demonstrated various changes consistent with a negative effect of r-mTBI on major cellular processes like depolymerization of microtubules, disassembly of filaments and loss of neurons, manifested by decrease of several proteins, including neurofilaments (NEFH, NEFM, NEFL), tubulin (TUBB2A, TUBA4A), microtubule-associated proteins (MAP1A, MAP1B), collagen (COL6A1, COL6A3) and increased expression of other proteins, including heat shock proteins (HSP90B1, HSPB1), APOE and cathepsin D. Lipidomic analysis showed quantitative changes in a number of phospholipid species, including a significant increase in the total amount of lysophosphatidylcholine (LPC), including the molecular species 16:0, a known demyelinating agent. The overall amount of some ether phospholipids, like ether LPC, ether phosphatidylcholine and ether lysophosphatidylethanolamine were also increased, while the majority of individual molecular species of ester phospholipids, like phosphatidylcholine and phosphatidylethanolamine, were decreased. Results from the biochemical analysis correlate well with changes detected by histological and immunohistochemical methods and indicate the involvement of

  10. Sub-Chronic Neuropathological and Biochemical Changes in Mouse Visual System after Repetitive Mild Traumatic Brain Injury

    PubMed Central

    Tzekov, Radouil; Dawson, Clint; Orlando, Megan; Mouzon, Benoit; Reed, Jon; Evans, James; Crynen, Gogce; Mullan, Michael; Crawford, Fiona

    2016-01-01

    Repetitive mild traumatic brain injury (r-mTBI) results in neuropathological and biochemical consequences in the human visual system. Using a recently developed mouse model of r-mTBI, with control mice receiving repetitive anesthesia alone (r-sham) we assessed the effects on the retina and optic nerve using histology, immunohistochemistry, proteomic and lipidomic analyses at 3 weeks post injury. Retina tissue was used to determine retinal ganglion cell (RGC) number, while optic nerve tissue was examined for cellularity, myelin content, protein and lipid changes. Increased cellularity and areas of demyelination were clearly detectable in optic nerves in r-mTBI, but not in r-sham. These changes were accompanied by a ~25% decrease in the total number of Brn3a-positive RGCs. Proteomic analysis of the optic nerves demonstrated various changes consistent with a negative effect of r-mTBI on major cellular processes like depolymerization of microtubules, disassembly of filaments and loss of neurons, manifested by decrease of several proteins, including neurofilaments (NEFH, NEFM, NEFL), tubulin (TUBB2A, TUBA4A), microtubule-associated proteins (MAP1A, MAP1B), collagen (COL6A1, COL6A3) and increased expression of other proteins, including heat shock proteins (HSP90B1, HSPB1), APOE and cathepsin D. Lipidomic analysis showed quantitative changes in a number of phospholipid species, including a significant increase in the total amount of lysophosphatidylcholine (LPC), including the molecular species 16:0, a known demyelinating agent. The overall amount of some ether phospholipids, like ether LPC, ether phosphatidylcholine and ether lysophosphatidylethanolamine were also increased, while the majority of individual molecular species of ester phospholipids, like phosphatidylcholine and phosphatidylethanolamine, were decreased. Results from the biochemical analysis correlate well with changes detected by histological and immunohistochemical methods and indicate the involvement of

  11. Detection of hypoxic cells with the 2-nitroimidazole, EF5, correlates with early redox changes in rat brain after perinatal hypoxia-ischemia.

    PubMed

    Bergeron, M; Evans, S M; Sharp, F R; Koch, C J; Lord, E M; Ferriero, D M

    1999-01-01

    The hypoxia-dependent activation of nitroheterocyclic drugs by cellular nitroreductases leads to the formation of intracellular adducts between the drugs and cellular macromolecules. Because this covalent binding is maximal in the absence of oxygen, detection of bound adducts provides an assay for estimating the degree of cellular hypoxia in vivo. Using a pentafluorintated derivative of etanidazole called EF5, we studied the distribution of EF5 adducts in seven-day-old rats subjected to different treatments which decrease the level of oxygen in the brain. EF5 solution was administered intraperitoneally 30 min prior to each treatment. The effect of acute and chronic hypoxia on EF5 adduct formation (binding) was studied in the brain of newborn rats exposed to global hypoxia (8% O2 for 30, 90 or 150 min) and in the brain of chronically hypoxic rat pups with congenital cardiac defects (Wistar Kyoto). The effect of combined hypoxia-ischemia was investigated in rat pups subjected to right carotid coagulation and concurrent exposure to 8% O2 for 30, 90 or 150 min. Brains were frozen immediately at the end of each treatment. Using a Cy3-conjugated monoclonal mouse antibody (ELK3-51) raised against EF5 adducts, hypoxic cells within brain regions were visualized by fluorescence immunocytochemistry. Brains from controls or vehicle-injected animals showed no EF5 binding. Notably, brains from animals which were chronically hypoxemic as a result of congenital cardiac defects also showed no EF5 binding. A short exposure (30 min) to hypoxia or to combined hypoxia-ischemia resulted in increased background stain and few scattered cells with low-intensity immunostaining. Acute hypoxia exposure of at least 90-150 min, which in this age animal does not result in frank cellular damage, produced patchy areas of low- to moderate-intensity fluorescence scattered throughout the brain. In contrast, 90-150 min of hypoxia-ischemia was associated with intense immunofluorescence in the

  12. Therapeutic and space radiation exposure of mouse brain causes impaired DNA repair response and premature senescence by chronic oxidant production

    PubMed Central

    Suman, Shubhankar; Rodriguez, Olga C.; Winters, Thomas A.; Fornace, Albert J.; Albanese, Chris; Datta, Kamal

    2013-01-01

    Despite recent epidemiological evidences linking radiation exposure and a number of human ailments including cancer, mechanistic understanding of how radiation inflicts long-term changes in cerebral cortex, which regulates important neuronal functions, remains obscure. The current study dissects molecular events relevant to pathology in cerebral cortex of 6 to 8 weeks old female C57BL/6J mice two and twelve months after exposure to a γ radiation dose (2 Gy) commonly employed in fractionated radiotherapy. For a comparative study, effects of 1.6 Gy heavy ion56Fe radiation on cerebral cortex were also investigated, which has implications for space exploration. Radiation exposure was associated with increased chronic oxidative stress, oxidative DNA damage, lipid peroxidation, and apoptosis. These results when considered with decreased cortical thickness, activation of cell-cycle arrest pathway, and inhibition of DNA double strand break repair factors led us to conclude to our knowledge for the first time that radiation caused aging-like pathology in cerebral cortical cells and changes after heavy ion radiation were more pronounced than γ radiation. PMID:23928451

  13. Production of mouse monoclonal antibodies for the analysis of idiotypes in serum of patients with chronic lymphatic leukaemia.

    PubMed

    de Rie, M A; van Heemstra, D J; Huijgens, P C; Zeijlemaker, W P; Out, T A; Melief, C J; von dem Borne, A E

    1988-01-01

    In this report a simple procedure for the production of murine monoclonal antibodies (MoAb) against the idiotype of malignant B cells is described. Mice were immunized with lymphoid cells from patients with B-cell chronic lymphocytic leukaemia (B-CLL). After fusion of the spleen cells, hybridoma supernatants were screened for anti-idiotypic MoAb in ELISA with immunoglobulins obtained from tumour-cell lysates, xenohybridomas and patients' sera. The anti-idiotypic MoAb were used to study tumour cells and serum immunoglobulins (Ig) from four different patients with B-CLL. It was found that the serum IgM and IgD in one patient shared the same idiotype. Evidence is presented that IgG-secreting cell populations are not restricted to lambda-Ig-light chain-expressing B-CLL cells. With the help of anti-idiotype MoAb accurate measurements of total and idiotype-positive serum immunoglobulin levels during chemotherapy were possible. PMID:3257881

  14. A mouse model for chronic lymphocytic leukemia based on expression of the SV40 large T antigen.

    PubMed

    ter Brugge, Petra J; Ta, Van B T; de Bruijn, Marjolein J W; Keijzers, Guido; Maas, Alex; van Gent, Dik C; Hendriks, Rudi W

    2009-07-01

    The simian virus 40 (SV40) T antigen is a potent oncogene able to transform many cell types and has been implicated in leukemia and lymphoma. In this report, we have achieved sporadic SV40 T-antigen expression in mature B cells in mice, by insertion of a SV40 T antigen gene in opposite transcriptional orientation in the immunoglobulin (Ig) heavy (H) chain locus between the D and J(H) segments. SV40 T-antigen expression appeared to result from retention of the targeted germline allele and concomitant antisense transcription of SV40 large T in mature B cells, leading to chronic lymphocytic leukemia (CLL). Although B-cell development was unperturbed in young mice, aging mice showed accumulation of a monoclonal B-cell population in which the targeted IgH allele was in germline configuration and the wild-type IgH allele had a productive V(D)J recombination. These leukemic B cells were IgD(low)CD5(+) and manifested nonrandom usage of V, D, and J segments. V(H) regions were either unmutated, with preferential usage of the VH11 family, or manifested extensive somatic hypermutation. Our findings provide an animal model for B-CLL and show that pathways activated by SV40 T antigen play important roles in the pathogenesis of B-CLL. PMID:19332766

  15. Effect of chronic phenobarbitone administration on liver tumour formation in the C57BL/10J mouse.

    PubMed

    Jones, Huw B; Orton, Terry C; Lake, Brian G

    2009-06-01

    The hepatocarcinogenicity of sodium phenobarbitone (PB) was studied in male and female mice of the low spontaneous liver tumour incidence C57BL/10 J strain. Treatment with 200 and 1000 ppmPB for 1 month increased relative liver weight in both sexes, with 1000 ppmPB also producing a transient increase in replicative DNA synthesis. The treatment of male and female mice with 200 and 1000 ppm (the maximum tolerated dose) PB for 99 weeks resulted in centrilobular hypertrophy and a dose-dependent increase in relative liver weight. Altered hepatic foci were observed in both sexes given 1000 ppm PB. In male mice given 1000 ppm PB significant increases were observed in the incidence of hepatocellular adenoma and carcinoma, to 43% and 10% of the animals examined, respectively. No increase in liver tumours was observed in male mice given 200 ppm PB and in female mice given 200 and 1000 ppm PB. In summary, PB at a dose level which produces liver hypertrophy, a transient stimulation of replicative DNA synthesis and on chronic administration altered hepatic foci, three key events in the established mode of action for PB-induced rodent liver tumour formation, results in a significant increase in liver tumours in male C57BL/10 J mice. PMID:19298838

  16. Chronic hyperglycemia induced via the heterozygous knockout of Pdx1 worsens neuropathological lesion in an Alzheimer mouse model.

    PubMed

    Guo, Chuang; Zhang, Shuai; Li, Jia-Yi; Ding, Chen; Yang, Zhao-Hui; Chai, Rui; Wang, Xu; Wang, Zhan-You

    2016-01-01

    Compelling evidence has indicated that dysregulated glucose metabolism links Alzheimer's disease (AD) and diabetes mellitus (DM) via glucose metabolic products. Nevertheless, because of the lack of appropriate animal models, whether chronic hyperglycemia worsens AD pathologies in vivo remains to be confirmed. Here, we crossed diabetic mice (Pdx1(+/-) mice) with Alzheimer mice (APP/PS1 transgenic mice) to generate Pdx1(+/-)/APP/PS1. We identified robust increases in tau phosphorylation, the loss of the synaptic spine protein, amyloid-β (Aβ) deposition and plaque formation associated with increased microglial and astrocyte activation proliferation, which lead to exacerbated memory and cognition deficits. More importantly, we also observed increased glucose intolerance accompanied by Pdx1 reduction, the formation of advanced glycation end-products (AGEs), and the activation of the receptor for AGEs (RAGE) signaling pathways during AD progression; these changes are thought to contribute to the processing of Aβ precursor proteins and result in increased Aβ generation and decreased Aβ degradation. Protein glycation, increased oxidative stress and inflammation via hyperglycemia are the primary mechanisms involved in the pathophysiology of AD. These results indicate the pathological relationship between these diseases and provide novel insights suggesting that glycemic control may be beneficial for decreasing the incidence of AD in diabetic patients and delaying AD progression. PMID:27406855

  17. Differential Features between Chronic Skin Inflammatory Diseases Revealed in Skin-Humanized Psoriasis and Atopic Dermatitis Mouse Models.

    PubMed

    Carretero, Marta; Guerrero-Aspizua, Sara; Illera, Nuria; Galvez, Victoria; Navarro, Manuel; García-García, Francisco; Dopazo, Joaquin; Jorcano, Jose Luis; Larcher, Fernando; del Rio, Marcela

    2016-01-01

    Psoriasis and atopic dermatitis are chronic and relapsing inflammatory diseases of the skin affecting a large number of patients worldwide. Psoriasis is characterized by a T helper type 1 and/or T helper type 17 immunological response, whereas acute atopic dermatitis lesions exhibit T helper type 2-dominant inflammation. Current single gene and signaling pathways-based models of inflammatory skin diseases are incomplete. Previous work allowed us to model psoriasis in skin-humanized mice through proper combinations of inflammatory cell components and disruption of barrier function. Herein, we describe and characterize an animal model for atopic dermatitis using similar bioengineered-based approaches, by intradermal injection of human T helper type 2 lymphocytes in regenerated human skin after partial removal of stratum corneum. In this work, we have extensively compared this model with the previous and an improved version of the psoriasis model, in which T helper type 1 and/or T helper type 17 lymphocytes replace exogenous cytokines. Comparative expression analyses revealed marked differences in specific epidermal proliferation and differentiation markers and immune-related molecules, including antimicrobial peptides. Likewise, the composition of the dermal inflammatory infiltrate presented important differences. The availability of accurate and reliable animal models for these diseases will contribute to the understanding of the pathogenesis and provide valuable tools for drug development and testing. PMID:26763433

  18. YAP is up-regulated in the bronchial airway smooth muscle of the chronic asthma mouse model.

    PubMed

    Zhou, Jing; Xu, Fei; Yu, Jing Jing; Zhang, Wei

    2015-01-01

    Asthma is characterized by leukocytic infiltration and tissue remodeling with structural changes including subepithelial fibrosis and ASM cells proliferation. The Hippo pathway is a key regulatory point involved in cell proliferation, fibroblasts, and smooth muscle cell differentiation. In order to disclose the relation between asthma and the Hippo pathway, expression of the Yes-associated protein (YAP), a key gene in the Hippo pathway, in the bronchial smooth muscle of chronic asthma model (CAM) was studied. 40 mice were randomly divided into control (wide type) and experimental group to construct CAM using chicken ovalbumin (OVA). Pathological changes of the lung tissues were observed in the CAM mice compared with the control using HE staining method. Immunohistochemistry (IHC) was used to detect if YAP protein is expressed in the lung tissues. The pathological changes of the CAM group showed that a large number of inflammatory cells infiltration including mainly lymphocytes and a small amount of eosinophilic, with the presence of certain airway smooth muscle hyperplasia, was observed in comparison with the control. IHC results showed that the YAP protein was significantly increased compared with the control groups (P < 0.01). This result was further confirmed by quantitative real-time PCR (qPCR) assay which detected the up-regulation of the YAP gene (P < 0.01) and Western blot. In conclusion, the YAP protein was significantly expressed in the bronchial airway tissues of the CAM mice, and could be used as an indicator for asthma. PMID:26617833

  19. Chronic hyperglycemia induced via the heterozygous knockout of Pdx1 worsens neuropathological lesion in an Alzheimer mouse model

    PubMed Central

    Guo, Chuang; Zhang, Shuai; Li, Jia-Yi; Ding, Chen; Yang, Zhao-Hui; Chai, Rui; Wang, Xu; Wang, Zhan-You

    2016-01-01

    Compelling evidence has indicated that dysregulated glucose metabolism links Alzheimer’s disease (AD) and diabetes mellitus (DM) via glucose metabolic products. Nevertheless, because of the lack of appropriate animal models, whether chronic hyperglycemia worsens AD pathologies in vivo remains to be confirmed. Here, we crossed diabetic mice (Pdx1+/− mice) with Alzheimer mice (APP/PS1 transgenic mice) to generate Pdx1+/−/APP/PS1. We identified robust increases in tau phosphorylation, the loss of the synaptic spine protein, amyloid-β (Aβ) deposition and plaque formation associated with increased microglial and astrocyte activation proliferation, which lead to exacerbated memory and cognition deficits. More importantly, we also observed increased glucose intolerance accompanied by Pdx1 reduction, the formation of advanced glycation end-products (AGEs), and the activation of the receptor for AGEs (RAGE) signaling pathways during AD progression; these changes are thought to contribute to the processing of Aβ precursor proteins and result in increased Aβ generation and decreased Aβ degradation. Protein glycation, increased oxidative stress and inflammation via hyperglycemia are the primary mechanisms involved in the pathophysiology of AD. These results indicate the pathological relationship between these diseases and provide novel insights suggesting that glycemic control may be beneficial for decreasing the incidence of AD in diabetic patients and delaying AD progression. PMID:27406855

  20. Promoter Hypomethylation and Expression Is Conserved in Mouse Chronic Lymphocytic Leukemia Induced by Decreased or Inactivated Dnmt3a.

    PubMed

    Haney, Staci L; Upchurch, G Michael; Opavska, Jana; Klinkebiel, David; Hlady, Ryan A; Suresh, Abhinav; Pirruccello, Samuel J; Shukla, Vipul; Lu, Runqing; Costinean, Stefan; Rizzino, Angie; Karpf, Adam R; Joshi, Shantaram; Swanson, Patrick; Opavsky, Rene

    2016-05-10

    DNA methyltransferase 3a (DNMT3A) catalyzes the formation of 5-methyl-cytosine in mammalian genomic DNA, and it is frequently mutated in human hematologic malignancies. Bi-allelic loss of Dnmt3a in mice results in leukemia and lymphoma, including chronic lymphocytic leukemia (CLL). Here, we investigate whether mono-allelic loss of Dnmt3a is sufficient to induce disease. We show that, by 16 months of age, 65% of Dnmt3a(+/-) mice develop a CLL-like disease, and 15% of mice develop non-malignant myeloproliferation. Genome-wide methylation analysis reveals that reduced Dnmt3a levels induce promoter hypomethylation at similar loci in Dnmt3a(+/-) and Dnmt3a(Δ/Δ) CLL, suggesting that promoters are particularly sensitive to Dnmt3a levels. Gene expression analysis identified 26 hypomethylated and overexpressed genes common to both Dnmt3a(+/-) and Dnmt3a(Δ/Δ) CLL as putative oncogenic drivers. Our data provide evidence that Dnmt3a is a haplo-insufficient tumor suppressor in CLL and highlights the importance of deregulated molecular events in disease pathogenesis. PMID:27134162

  1. Promoter hypomethylation and expression is conserved in mouse chronic lymphocytic leukemia induced by decreased or inactivated Dnmt3a

    PubMed Central

    Haney, Staci L.; Upchurch, G. Michael; Opavska, Jana; Klinkebiel, David; Hlady, Ryan A.; Suresh, Abhinav; Pirruccello, Samuel J.; Shukla, Vipul; Lu, Runqing; Costinean, Stefan; Rizzino, Angie; Karpf, Adam R.; Joshi, Shantaram; Swanson, Patrick; Opavsky, Rene

    2016-01-01

    SUMMARY DNA methyltransferase 3a (DNMT3A) catalyzes the formation of 5-methyl-cytosine in mammalian genomic DNA and it is frequently mutated in human hematologic malignancies. Bi-allelic loss of Dnmt3a in mice results in leukemia and lymphoma, including chronic lymphocytic leukemia (CLL). Here we investigate whether mono-allelic loss of Dnmt3a is sufficient to induce disease. We show that by 16 months of age, 65% of Dnmt3a+/− mice develop a CLL-like disease and 15% of mice develop non-malignant myeloproliferation. Genome-wide methylation analysis reveals that reduced Dnmt3a levels induce promoter hypomethylation at similar loci in Dnmt3a+/− and Dnmt3aΔ/Δ CLL, suggesting that promoters are particularly sensitive to Dnmt3a levels. Gene-expression analysis identified 26 hypomethylated and over-expressed genes common to both Dnmt3a+/− and Dnmt3aΔ/Δ CLL as putative oncogenic drivers. Our data provide evidence that Dnmt3a is a haplo-insufficient tumor suppressor in CLL and highlights the importance of deregulated molecular events in disease pathogenesis. PMID:27134162

  2. Chronic hypoxia in pregnancy affects thymus development in Balb/c mouse offspring via IL2 Signaling.

    PubMed

    Zhang, Xiaopeng; Zhou, Xiuwen; Li, Lingjun; Sun, Miao; Gao, Qingqing; Zhang, Pengjie; Tang, Jiaqi; He, Yu; Zhu, Di; Xu, Zhice

    2016-04-01

    Hypoxia during pregnancy can adversely affect development. This study, addressed the impact of prenatal hypoxia on thymus development in the rodent offspring. Pregnant Balb/c mice were exposed to hypoxia or normoxia during pregnancy, and the thymuses of their offspring were tested. Chronic hypoxia during pregnancy resulted in significantly decreased fetal body weight, with an increased thymus-to-body weight ratio. Histological analysis revealed a smaller cortical zone in the thymus of the offspring exposed to hypoxia. A reduction in the cortical T lymphocyte population corresponded to increased mRNA abundance of caspase 3 (Casp3) and decreased expression of the proliferation marker Ki-67 (Mki67). Differences in T lymphocyte sub-populations in the thymus further indicate that thymus development in offspring was retarded or stagnated by prenatal hypoxia. The abundance of IL2 and its receptor was reduced in the thymus following prenatal hypoxia. This was accompanied by an increase in thymus HIF1A and IKKβ and a decrease in phosphorylated NFKB, MAP2K1, and MAPK1/3 compared to control pregnancies. Together, these results implicate deficiencies in IL2-mediated signaling as one source of prenatal-hypoxia-impaired thymus development. PMID:26918321

  3. Therapeutic and space radiation exposure of mouse brain causes impaired DNA repair response and premature senescence by chronic oxidant production.

    PubMed

    Suman, Shubhankar; Rodriguez, Olga C; Winters, Thomas A; Fornace, Albert J; Albanese, Chris; Datta, Kamal

    2013-08-01

    Despite recent epidemiological evidences linking radiation exposure and a number of human ailments including cancer, mechanistic understanding of how radiation inflicts long-term changes in cerebral cortex, which regulates important neuronal functions, remains obscure. The current study dissects molecular events relevant to pathology in cerebral cortex of 6 to 8 weeks old female C57BL/6J mice two and twelve months after exposure to a γ radiation dose (2 Gy) commonly employed in fractionated radiotherapy. For a comparative study, effects of 1.6 Gy heavy ion 56Fe radiation on cerebral cortex were also investigated, which has implications for space exploration. Radiation exposure was associated with increased chronic oxidative stress, oxidative DNA damage, lipid peroxidation, and apoptosis. These results when considered with decreased cortical thickness, activation of cell-cycle arrest pathway, and inhibition of DNA double strand break repair factors led us to conclude to our knowledge for the first time that radiation caused aging-like pathology in cerebral cortical cells and changes after heavy ion radiation were more pronounced than γ radiation. PMID:23928451

  4. Clinical results of hypoxic cell radiosensitisation from hyperbaric oxygen to accelerated radiotherapy, carbogen and nicotinamide.

    PubMed Central

    Saunders, M.; Dische, S.

    1996-01-01

    The 40-year history of hypoxic cell sensitisation can be traced from hyperbaric oxygen to the present clinical studies with carbogen, nicotinamide and accelerated radiotherapy. A meta-analysis by Overgaard (1995) included 10703 cases entered into 83 randomised controlled trials and showed an overall improvement in local tumour control of 4.6% (P = 0.00001) and in survival of 2.8% (P = 0.005). Hyperbaric oxygen gave a 6.6% (P = 0.003) improvement in local control and hypoxic cell sensitisers 3.9% (P = 0.04). Despite this, the only hypoxic cell-sensitising method in routine clinical use is the giving of nimorazole in supraglottic and pharyngeal carcinomas. Acute, as well as chronic hypoxia has been recognised and nicotinamide, the amide derivative of B3 is believed to prevent the former. Thus ARCON (accelerated radiotherapy, carbogen and nicotinamide) has been introduced in the clinic in an effort to overcome tumour proliferation, chronic and acute hypoxia, respectively. The success of future randomised controlled trials would be improved greatly if methods were available to measure the concentration of hypoxic cells in tumours before treatment and thus select those where benefit may be gained. The use of ARCON recognises that tumour cell proliferation is an important cause of failure in addition to hypoxia. However, intrinsic radiosensitivity may also need to be taken into account in the future. Clinical trials aim to improve the therapeutic ratio and thus the study of morbidity is as important as local tumour control. International collaboration is essential if randomised controlled trials are to be carried out within reasonable periods of time. PMID:8763896

  5. Transcriptomic changes in human renal proximal tubular cells revealed under hypoxic conditions by RNA sequencing.

    PubMed

    Yu, Wenmin; Li, Yiping; Wang, Zhi; Liu, Lei; Liu, Jing; Ding, Fengan; Zhang, Xiaoyi; Cheng, Zhengyuan; Chen, Pingsheng; Dou, Jun

    2016-09-01

    Chronic hypoxia often occurs among patients with chronic kidney disease (CKD). Renal proximal tubular cells may be the primary target of a hypoxic insult. However, the underlying transcriptional mechanisms remain undefined. In this study, we revealed the global changes in gene expression in HK‑2 human renal proximal tubular cells under hypoxic and normoxic conditions. We analyzed the transcriptome of HK‑2 cells exposed to hypoxia for 24 h using RNA sequencing. A total of 279 differentially expressed genes was examined, as these genes could potentially explain the differences in HK‑2 cells between hypoxic and normoxic conditions. Moreover, 17 genes were validated by qPCR, and the results were highly concordant with the RNA seqencing results. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to better understand the functions of these differentially expressed genes. The upregulated genes appeared to be significantly enriched in the pathyway of extracellular matrix (ECM)-receptor interaction, and in paticular, the pathway of renal cell carcinoma was upregulated under hypoxic conditions. The downregulated genes were enriched in the signaling pathway related to antigen processing and presentation; however, the pathway of glutathione metabolism was downregulated. Our analysis revealed numerous novel transcripts and alternative splicing events. Simultaneously, we also identified a large number of single nucleotide polymorphisms, which will be a rich resource for future marker development. On the whole, our data indicate that transcriptome analysis provides valuable information for a more in depth understanding of the molecular mechanisms in CKD and renal cell carcinoma. PMID:27432315

  6. Hypoxia affects in vitro proliferation and differentiation of mouse corneal epithelial progenitor cell.

    PubMed

    Dong, Nuo; Qin, Wenjuan; Xue, Yuhua; Li, Cheng; Liu, Zuguo

    2013-08-01

    This study was to investigate the proliferation and differentiation of mouse corneal epithelial progenitor cell in hypoxic airlift culture. Mouse corneal epithelial progenitor cell line progenitor cells were cultured under airlift with normoxic and hypoxic conditions for various durations up to 2 wk. Under normoxic conditions when exposed to air, the hyperproliferation and abnormal epidermal-like differentiation of mouse corneal epithelium was induced, whereas when exposed to air under hypoxic conditions, although we observed augmented proliferation, the abnormal differentiation was inhibited. The mechanism by which hypoxia prevents abnormal differentiation may involve downregulation of Wnt signaling pathways, which were inhibited in cells cultured with hypoxic airlift technique. In conclusion, hypoxia can prevent abnormal differentiation while enhancing the proliferation of corneal epithelial cells by blocking Wnt/β-catenin signaling pathway. PMID:23739874

  7. Protection of Cardiomyocytes from Ischemic/Hypoxic Cell Death via Drbp1 and pMe2GlyDH in Cardio-specific ARC Transgenic Mice*

    PubMed Central

    Pyo, Jong-Ok; Nah, Jihoon; Kim, Hyo-Jin; Chang, Jae-Woong; Song, Young-Wha; Yang, Dong-Kwon; Jo, Dong-Gyu; Kim, Hyung-Ryong; Chae, Han-Jung; Chae, Soo-Wan; Hwang, Seung-Yong; Kim, Seung-Jun; Kim, Hyo-Joon; Cho, Chunghee; Oh, Chang-Gyu; Park, Woo Jin; Jung, Yong-Keun

    2008-01-01

    The ischemic death of cardiomyocytes is associated in heart disease and heart failure. However, the molecular mechanism underlying ischemic cell death is not well defined. To examine the function of apoptosis repressor with a caspase recruitment domain (ARC) in the ischemic/hypoxic damage of cardiomyocytes, we generated cardio-specific ARC transgenic mice using a mouse α-myosin heavy chain promoter. Compared with the control, the hearts of ARC transgenic mice showed a 3-fold overexpression of ARC. Langendoff preparation showed that the hearts isolated from ARC transgenic mice exhibited improved recovery of contractile performance during reperfusion. The cardiomyocytes cultured from neonatal ARC transgenic mice were significantly resistant to hypoxic cell death. Furthermore, the ARC C-terminal calcium-binding domain was as potent to protect cardiomyocytes from hypoxic cell death as ARC. Genome-wide RNA expression profiling uncovered a list of genes whose expression was changed (>2-fold) in ARC transgenic mice. Among them, expressional regulation of developmentally regulated RNA-binding protein 1 (Drbp1) or the dimethylglycine dehydrogenase precursor (pMe2GlyDH) affected hypoxic death of cardiomyocytes. These results suggest that ARC may protect cardiomyocytes from hypoxic cell death by regulating its downstream, Drbp1 and pMe2GlyDH, shedding new insights into the protection of heart from hypoxic damages. PMID:18782777

  8. Targeting lactate-fueled respiration selectively kills hypoxic tumor cells in mice

    PubMed Central

    Sonveaux, Pierre; Végran, Frédérique; Schroeder, Thies; Wergin, Melanie C.; Verrax, Julien; Rabbani, Zahid N.; De Saedeleer, Christophe J.; Kennedy, Kelly M.; Diepart, Caroline; Jordan, Bénédicte F.; Kelley, Michael J.; Gallez, Bernard; Wahl, Miriam L.; Feron, Olivier; Dewhirst, Mark W.

    2008-01-01

    Tumors contain oxygenated and hypoxic regions, so the tumor cell population is heterogeneous. Hypoxic tumor cells primarily use glucose for glycolytic energy production and release lactic acid, creating a lactate gradient that mirrors the oxygen gradient in the tumor. By contrast, oxygenated tumor cells have been thought to primarily use glucose for oxidative energy production. Although lactate is generally considered a waste product, we now show that it is a prominent substrate that fuels the oxidative metabolism of oxygenated tumor cells. There is therefore a symbiosis in which glycolytic and oxidative tumor cells mutually regulate their access to energy metabolites. We identified monocarboxylate transporter 1 (MCT1) as the prominent path for lactate uptake by a human cervix squamous carcinoma cell line that preferentially utilized lactate for oxidative metabolism. Inhibiting MCT1 with α-cyano-4-hydroxycinnamate (CHC) or siRNA in these cells induced a switch from lactate-fueled respiration to glycolysis. A similar switch from lactate-fueled respiration to glycolysis by oxygenated tumor cells in both a mouse model of lung carcinoma and xenotransplanted human colorectal adenocarcinoma cells was observed after administration of CHC. This retarded tumor growth, as the hypoxic/glycolytic tumor cells died from glucose starvation, and rendered the remaining cells sensitive to irradiation. As MCT1 was found to be expressed by an array of primary human tumors, we suggest that MCT1 inhibition has clinical antitumor potential. PMID:19033663

  9. Chronic exposure to simulated space conditions predominantly affects cytoskeleton remodeling and oxidative stress response in mouse fetal fibroblasts.

    PubMed

    Beck, Michaël; Moreels, Marjan; Quintens, Roel; Abou-El-Ardat, Khalil; El-Saghire, Hussein; Tabury, Kevin; Michaux, Arlette; Janssen, Ann; Neefs, Mieke; Van Oostveldt, Patrick; De Vos, Winnok H; Baatout, Sarah

    2014-08-01

    Microgravity and cosmic rays as found in space are difficult to recreate on earth. However, ground-based models exist to simulate space flight experiments. In the present study, an experimental model was utilized to monitor gene expression changes in fetal skin fibroblasts of murine origin. Cells were continuously subjected for 65 h to a low dose (55 mSv) of ionizing radiation (IR), comprising a mixture of high‑linear energy transfer (LET) neutrons and low-LET gamma-rays, and/or simulated microgravity using the random positioning machine (RPM), after which microarrays were performed. The data were analyzed both by gene set enrichment analysis (GSEA) and single gene analysis (SGA). Simulated microgravity affected fetal murine fibroblasts by inducing oxidative stress responsive genes. Three of these genes are targets of the nuclear factor‑erythroid 2 p45-related factor 2 (Nrf2), which may play a role in the cell response to simulated microgravity. In addition, simulated gravity decreased the expression of genes involved in cytoskeleton remodeling, which may have been caused by the downregulation of the serum response factor (SRF), possibly through the Rho signaling pathway. Similarly, chronic exposure to low-dose IR caused the downregulation of genes involved in cytoskeleton remodeling, as well as in cell cycle regulation and DNA damage response pathways. Many of the genes or gene sets that were altered in the individual treatments (RPM or IR) were not altered in the combined treatment (RPM and IR), indicating a complex interaction between RPM and IR. PMID:24859186

  10. Effects of Chronic Sleep Restriction during Early Adolescence on the Adult Pattern of Connectivity of Mouse Secondary Motor Cortex123

    PubMed Central

    Billeh, Yazan N.; Bernard, Amy; de Vivo, Luisa; Honjoh, Sakiko; Mihalas, Stefan; Ng, Lydia; Koch, Christof

    2016-01-01

    Abstract Cortical circuits mature in stages, from early synaptogenesis and synaptic pruning to late synaptic refinement, resulting in the adult anatomical connection matrix. Because the mature matrix is largely fixed, genetic or environmental factors interfering with its establishment can have irreversible effects. Sleep disruption is rarely considered among those factors, and previous studies have focused on very young animals and the acute effects of sleep deprivation on neuronal morphology and cortical plasticity. Adolescence is a sensitive time for brain remodeling, yet whether chronic sleep restriction (CSR) during adolescence has long-term effects on brain connectivity remains unclear. We used viral-mediated axonal labeling and serial two-photon tomography to measure brain-wide projections from secondary motor cortex (MOs), a high-order area with diffuse projections. For each MOs target, we calculated the projection fraction, a combined measure of passing fibers and axonal terminals normalized for the size of each target. We found no homogeneous differences in MOs projection fraction between mice subjected to 5 days of CSR during early adolescence (P25–P30, ≥50% decrease in daily sleep, n=14) and siblings that slept undisturbed (n=14). Machine learning algorithms, however, classified animals at significantly above chance levels, indicating that differences between the two groups exist, but are subtle and heterogeneous. Thus, sleep disruption in early adolescence may affect adult brain connectivity. However, because our method relies on a global measure of projection density and was not previously used to measure connectivity changes due to behavioral manipulations, definitive conclusions on the long-term structural effects of early CSR require additional experiments. PMID:27351022

  11. Effects of Chronic Sleep Restriction during Early Adolescence on the Adult Pattern of Connectivity of Mouse Secondary Motor Cortex.

    PubMed

    Billeh, Yazan N; Rodriguez, Alexander V; Bellesi, Michele; Bernard, Amy; de Vivo, Luisa; Funk, Chadd M; Harris, Julie; Honjoh, Sakiko; Mihalas, Stefan; Ng, Lydia; Koch, Christof; Cirelli, Chiara; Tononi, Giulio

    2016-01-01

    Cortical circuits mature in stages, from early synaptogenesis and synaptic pruning to late synaptic refinement, resulting in the adult anatomical connection matrix. Because the mature matrix is largely fixed, genetic or environmental factors interfering with its establishment can have irreversible effects. Sleep disruption is rarely considered among those factors, and previous studies have focused on very young animals and the acute effects of sleep deprivation on neuronal morphology and cortical plasticity. Adolescence is a sensitive time for brain remodeling, yet whether chronic sleep restriction (CSR) during adolescence has long-term effects on brain connectivity remains unclear. We used viral-mediated axonal labeling and serial two-photon tomography to measure brain-wide projections from secondary motor cortex (MOs), a high-order area with diffuse projections. For each MOs target, we calculated the projection fraction, a combined measure of passing fibers and axonal terminals normalized for the size of each target. We found no homogeneous differences in MOs projection fraction between mice subjected to 5 days of CSR during early adolescence (P25-P30, ≥ 50% decrease in daily sleep, n=14) and siblings that slept undisturbed (n=14). Machine learning algorithms, however, classified animals at significantly above chance levels, indicating that differences between the two groups exist, but are subtle and heterogeneous. Thus, sleep disruption in early adolescence may affect adult brain connectivity. However, because our method relies on a global measure of projection density and was not previously used to measure connectivity changes due to behavioral manipulations, definitive conclusions on the long-term structural effects of early CSR require additional experiments. PMID:27351022

  12. Hypoxic cell turnover in different solid tumor lines

    SciTech Connect

    Ljungkvist, Anna S.E. . E-mail: a.ljungkvist@rther.umcn.nl; Bussink, Johan; Kaanders, Johannes H.A.M.; Rijken, Paulus F.J.W.; Begg, Adrian C.; Raleigh, James A.; Kogel, Albert J. van der

    2005-07-15

    Purpose: Most solid tumors contain hypoxic cells, and the amount of tumor hypoxia has been shown to have a negative impact on the outcome of radiotherapy. The efficacy of combined modality treatments depends both on the sequence and timing of the treatments. Hypoxic cell turnover in tumors may be important for optimal scheduling of combined modality treatments, especially when hypoxic cell targeting is involved. Methods and Materials: Previously we have shown that a double bioreductive hypoxic marker assay could be used to detect changes of tumor hypoxia in relation to the tumor vasculature after carbogen and hydralazine treatments. This assay was used in the current study to establish the turnover rate of hypoxic cells in three different tumor models. The first hypoxic marker, pimonidazole, was administered at variable times before tumor harvest, and the second hypoxic marker, CCI-103F, was injected at a fixed time before harvest. Hypoxic cell turnover was defined as loss of pimonidazole (first marker) relative to CCI-103F (second marker). Results: The half-life of hypoxic cell turnover was 17 h in the murine C38 colon carcinoma line, 23 h and 49 h in the human xenograft lines MEC82 and SCCNij3, respectively. Within 24 h, loss of pimonidazole-stained areas in C38 and MEC82 occurred concurrent with the appearance of pimonidazole positive cell debris in necrotic regions. In C38 and MEC82, most of the hypoxic cells had disappeared after 48 h, whereas in SCCNij3, viable cells that had been labeled with pimonidazole were still observed after 5 days. Conclusions: The present study demonstrates that the double hypoxia marker assay can be used to study changes in both the proportion of hypoxic tumor cells and their lifespan at the same time. The present study shows that large differences in hypoxic cell turnover rates may exist among tumor lines, with half-lives ranging from 17-49 h.

  13. Hypoxia-inducible Factor-dependent Production of Profibrotic Mediators by Hypoxic Hepatocytes

    PubMed Central

    Copple, Bryan L.; Bustamante, Juan J.; Welch, Timothy P.; Kim, Nam Deuk; Moon, Jeon-OK

    2011-01-01

    Background/Aims During the development of liver fibrosis, mediators are produced that stimulate cells in the liver to differentiate into myofibroblasts and to produce collagen. Recent studies demonstrated that the transcription factor, hypoxia-inducible factor-1α (HIF-1α), is critical for upregulation of profibrotic mediators, such as platelet-derived growth factor-A (PDGF-A), PDGF-B, and plasminogen activator inhibitor-1 (PAI-1) in the liver during the development of fibrosis. What remains unknown is the cell type-specific regulation of these genes by HIF-1α in liver cell types. Accordingly, the hypothesis was tested that HIF-1α is activated in hypoxic hepatocytes and regulates production of profibrotic mediators by these cells. Methods In this study, hepatocytes were isolated from the livers of control and HIF-1α or HIF-1β-Deficient mice and exposed to hypoxia. Results Exposure of primary mouse hepatocytes to 1% oxygen stimulated nuclear accumulation of HIF-1α and upregulated PAI-1, vascular endothelial cell growth factor, and the vasoactive peptides adrenomedullin-1 (ADM-1) and ADM-2. In contrast, levels of PDGF-A and PDGF-B mRNAs were unaffected in these cells by hypoxia. Exposure of HIF-1α-Deficient hepatocytes to 1% oxygen only partially prevented upregulation of these genes, suggesting that other hypoxia-regulated transcription factors, such as HIF-2α, may also regulate these genes. In support of this, HIF-2α was activated in hypoxic hepatocytes, and exposure of HIF-1β-Deficient hepatocytes to 1% oxygen completely prevented upregulation PAI-1, VEGF, and ADM-1, suggesting that HIF-2α may also contribute to upregulation of these genes in hypoxic hepatocytes. Conclusions Collectively, our results suggest that HIFs may be important regulators of profibrotic and vasoactive mediators by hypoxic hepatocytes. PMID:19302442

  14. Metabolic adaptation to chronic hypoxia in cardiac mitochondria.

    PubMed

    Heather, Lisa C; Cole, Mark A; Tan, Jun-Jie; Ambrose, Lucy J A; Pope, Simon; Abd-Jamil, Amira H; Carter, Emma E; Dodd, Michael S; Yeoh, Kar Kheng; Schofield, Christopher J; Clarke, Kieran

    2012-05-01

    Chronic hypoxia decreases cardiomyocyte respiration, yet the mitochondrial mechanisms remain largely unknown. We investigated the mitochondrial metabolic pathways and enzymes that were decreased following in vivo hypoxia, and questioned whether hypoxic adaptation was protective for the mitochondria. Wistar rats were housed in hypoxia (7 days acclimatisation and 14 days at 11% oxygen), while control rats were housed in normoxia. Chronic exposure to physiological hypoxia increased haematocrit and cardiac vascular endothelial growth factor, in the absence of weight loss and changes in cardiac mass. In both subsarcolemmal (SSM) and interfibrillar (IFM) mitochondria isolated from hypoxic hearts, state 3 respiration rates with fatty acid were decreased by 17-18%, and with pyruvate were decreased by 29-15%, respectively. State 3 respiration rates with electron transport chain (ETC) substrates were decreased only in hypoxic SSM, not in hypoxic IFM. SSM from hypoxic hearts had decreased activities of ETC complexes I, II and IV, which were associated with decreased reactive oxygen species generation and protection against mitochondrial permeability transition pore (MPTP) opening. In contrast, IFM from hypoxic hearts had decreased activity of the Krebs cycle enzyme, aconitase, which did not modify ROS production or MPTP opening. In conclusion, cardiac mitochondrial respiration was decreased following chronic hypoxia, associated with downregulation of different pathways in the two mitochondrial populations, determined by their subcellular location. Hypoxic adaptation was not deleterious for the mitochondria, in fact, SSM acquired increased protection against oxidative damage under the oxygen-limited conditions. PMID:22538979

  15. Dysfunctional Presynaptic M2 Receptors in the Presence of Chronically High Acetylcholine Levels: Data from the PRiMA Knockout Mouse

    PubMed Central

    Mohr, Franziska; Krejci, Eric; Zimmermann, Martina; Klein, Jochen

    2015-01-01

    The muscarinic M2 receptor (M2R) acts as a negative feedback regulator in central cholinergic systems. Activation of the M2 receptor limits acetylcholine (ACh) release, especially when ACh levels are increased because acetylcholinesterase (AChE) activity is acutely inhibited. Chronically high ACh levels in the extracellular space, however, were reported to down-regulate M2R to various degrees. In the present study, we used the PRiMA knockout mouse which develops severely reduced AChE activity postnatally to investigate ACh release, and we used microdialysis to investigate whether the function of M2R to reduce ACh release in vivo was impaired in adult PRiMA knockout mice. We first show that striatal and hippocampal ACh levels, while strongly increased, still respond to AChE inhibitors. Infusion or injection of oxotremorine, a muscarinic M2 agonist, reduced ACh levels in wild-type mice but did not significantly affect ACh levels in PRiMA knockout mice or in wild-type mice in which ACh levels were artificially increased by infusion of neostigmine. Scopolamine, a muscarinic antagonist, increased ACh levels in wild-type mice receiving neostigmine, but not in wild-type mice or in PRiMA knockout mice. These results demonstrate that M2R are dysfunctional and do not affect ACh levels in PRiMA knockout mice, likely because of down-regulation and/or loss of receptor-effector coupling. Remarkably, this loss of function does not affect cognitive functions in PRiMA knockout mice. Our results are discussed in the context of AChE inhibitor therapy as used in dementia. PMID:26506622

  16. Cognitive recovery by chronic activation of the large-conductance calcium-activated potassium channel in a mouse model of Alzheimer's disease.

    PubMed

    Wang, Li; Kang, Huicong; Li, Yongzhi; Shui, Yuan; Yamamoto, Ryo; Sugai, Tokio; Kato, Nobuo

    2015-05-01

    We previously showed that activity of the large conductance calcium-activated potassium (Big-K; BK) channels is suppressed in 3xTg Alzheimer disease (AD) model mice. However, its behavioral significance is not known. In the present report, ventricular injection of the BK channel activator isopimaric acid (ISO) was conducted to examine whether BK channel activation ameliorates cognition in 3xTg mice. The novel object recognition (NOR) test revealed that chronic injection of ISO improved non-spatial memory in 3xTg mice. In the Morris water maze, the probe test demonstrated an improved spatial memory after ISO injection. Electrophysiological underpinnings of the ISO effect were then examined in slices obtained from the mice after behavior. At hippocampal CA1 synapses, the basic synaptic transmission was abnormally elevated and long-term potentiation (LTP) was partially suppressed in 3xTg mice. These were both recovered by ISO treatment. We then confirmed suppressed BK channel activity in 3xTg mice by measuring the half-width of evoked action potentials. This was also recovered by ISO treatment. We previously showed that the recovery of BK channel activity accompanies reduction of neuronal excitability in pyramidal cells. Here again, pyramidal cell excitability, as assessed by calculating the frequency of evoked spikes, was elevated in the 3xTg mouse and was normalized by ISO. ELISA experiments demonstrated an ISO-induced reduction of Aβ1-42 content in hippocampal tissue in 3xTg mice. The present study thus suggests a potential therapeutic utility of BK channel activators for AD. PMID:25577958

  17. Measuring DNA Damage and Repair in Mouse Splenocytes After Chronic In Vivo Exposure to Very Low Doses of Beta- and Gamma-Radiation.

    PubMed

    Flegal, Matthew; Blimkie, Melinda S; Wyatt, Heather; Bugden, Michelle; Surette, Joel; Klokov, Dmitry

    2015-01-01

    Low dose radiation exposure may produce a variety of biological effects that are different in quantity and quality from the effects produced by high radiation doses. Addressing questions related to environmental, occupational and public health safety in a proper and scientifically justified manner heavily relies on the ability to accurately measure the biological effects of low dose pollutants, such as ionizing radiation and chemical substances. DNA damage and repair are the most important early indicators of health risks due to their potential long term consequences, such as cancer. Here we describe a protocol to study the effect of chronic in vivo exposure to low doses of γ- and β-radiation on DNA damage and repair in mouse spleen cells. Using a commonly accepted marker of DNA double-strand breaks, phosphorylated histone H2AX called γH2AX, we demonstrate how it can be used to evaluate not only the levels of DNA damage, but also changes in the DNA repair capacity potentially produced by low dose in vivo exposures. Flow cytometry allows fast, accurate and reliable measurement of immunofluorescently labeled γH2AX in a large number of samples. DNA double-strand break repair can be evaluated by exposing extracted splenocytes to a challenging dose of 2 Gy to produce a sufficient number of DNA breaks to trigger repair and by measuring the induced (1 hr post-irradiation) and residual DNA damage (24 hrs post-irradiation). Residual DNA damage would be indicative of incomplete repair and the risk of long-term genomic instability and cancer. Combined with other assays and end-points that can easily be measured in such in vivo studies (e.g., chromosomal aberrations, micronuclei frequencies in bone marrow reticulocytes, gene expression, etc.), this approach allows an accurate and contextual evaluation of the biological effects of low level stressors. PMID:26168333

  18. Mouse chronic social stress increases blood and brain kynurenine pathway activity and fear behaviour: Both effects are reversed by inhibition of indoleamine 2,3-dioxygenase.

    PubMed

    Fuertig, René; Azzinnari, Damiano; Bergamini, Giorgio; Cathomas, Flurin; Sigrist, Hannes; Seifritz, Erich; Vavassori, Stefano; Luippold, Andreas; Hengerer, Bastian; Ceci, Angelo; Pryce, Christopher R

    2016-05-01

    Psychosocial stress is a major risk factor for mood and anxiety disorders, in which excessive reactivity to aversive events/stimuli is a major psychopathology. In terms of pathophysiology, immune-inflammation is an important candidate, including high blood and brain levels of metabolites belonging to the kynurenine pathway. Animal models are needed to study causality between psychosocial stress, immune-inflammation and hyper-reactivity to aversive stimuli. The present mouse study investigated effects of psychosocial stress as chronic social defeat (CSD) versus control-handling (CON) on: Pavlovian tone-shock fear conditioning, activation of the kynurenine pathway, and efficacy of a specific inhibitor (IDOInh) of the tryptophan-kynurenine catabolising enzyme indoleamine 2,3-dioxygenase (IDO1), in reversing CSD effects on the kynurenine pathway and fear. CSD led to excessive fear learning and memory, whilst repeated oral escitalopram (antidepressant and anxiolytic) reversed excessive fear memory, indicating predictive validity of the model. CSD led to higher blood levels of TNF-α, IFN-γ, kynurenine (KYN), 3-hydroxykynurenine (3-HK) and kynurenic acid, and higher KYN and 3-HK in amygdala and hippocampus. CSD was without effect on IDO1 gene or protein expression in spleen, ileum and liver, whilst increasing liver TDO2 gene expression. Nonetheless, oral IDOInh reduced blood and brain levels of KYN and 3-HK in CSD mice to CON levels, and we therefore infer that CSD increases IDO1 activity by increasing its post-translational activation. Furthermore, repeated oral IDOInh reversed excessive fear memory in CSD mice to CON levels. IDOInh reversal of CSD-induced hyper-activity in the kynurenine pathway and fear system contributes significantly to the evidence for a causal pathway between psychosocial stress, immune-inflammation and the excessive fearfulness that is a major psychopathology in stress-related neuropsychiatric disorders. PMID:26724575

  19. BL-7010 Demonstrates Specific Binding to Gliadin and Reduces Gluten-Associated Pathology in a Chronic Mouse Model of Gliadin Sensitivity

    PubMed Central

    McCarville, Justin L.; Nisemblat, Yotam; Galipeau, Heather J.; Jury, Jennifer; Tabakman, Rinat; Cohen, Ad; Naftali, Esmira; Neiman, Bela; Halbfinger, Efrat; Murray, Joseph A.; Anbazhagan, Arivarasu N.; Dudeja, Pradeep K.; Varvak, Alexander; Leroux, Jean-Christophe; Verdu, Elena F.

    2014-01-01

    Celiac disease (CD) is an autoimmune disorder in individuals that carry DQ2 or DQ8 MHC class II haplotypes, triggered by the ingestion of gluten. There is no current treatment other than a gluten-free diet (GFD). We have previously shown that the BL-7010 copolymer poly(hydroxyethyl methacrylate-co-styrene sulfonate) (P(HEMA-co-SS)) binds with higher efficiency to gliadin than to other proteins present in the small intestine, ameliorating gliadin-induced pathology in the HLA-HCD4/DQ8 model of gluten sensitivity. The aim of this study was to investigate the efficiency of two batches of BL-7010 to interact with gliadin, essential vitamins and digestive enzymes not previously tested, and to assess the ability of the copolymer to reduce gluten-associated pathology using the NOD-DQ8 mouse model, which exhibits more significant small intestinal damage when challenged with gluten than HCD4/DQ8 mice. In addition, the safety and systemic exposure of BL-7010 was evaluated in vivo (in rats) and in vitro (genetic toxicity studies). In vitro binding data showed that BL-7010 interacted with high affinity with gliadin and that BL-7010 had no interaction with the tested vitamins and digestive enzymes. BL-7010 was effective at preventing gluten-induced decreases in villus-to-crypt ratios, intraepithelial lymphocytosis and alterations in paracellular permeability and putative anion transporter-1 mRNA expression in the small intestine. In rats, BL-7010 was well-tolerated and safe following 14 days of daily repeated administration of 3000 mg/kg. BL-7010 did not exhibit any mutagenic effect in the genetic toxicity studies. Using complementary animal models and chronic gluten exposure the results demonstrate that administration of BL-7010 is effective and safe and that it is able to decrease pathology associated with gliadin sensitization warranting the progression to Phase I trials in humans. PMID:25365555

  20. The Effect of Hypoxic Preconditioning on Induced Schwann Cells under Hypoxic Conditions

    PubMed Central

    Chen, Ou; Wu, Miaomiao; Jiang, Liangfu

    2015-01-01

    Object Our objective was to explore the protective effects of hypoxic preconditioning on induced Schwann cells exposed to an environment with low concentrations of oxygen. It has been observed that hypoxic preconditioning of induced Schwann cells can promote axonal regeneration under low oxygen conditions. Method Rat bone marrow mesenchymal stem cells (MSCs) were differentiated into Schwann cells and divided into a normal oxygen control group, a hypoxia-preconditioning group and a hypoxia group. The ultrastructure of each of these groups of cells was observed by electron microscopy. In addition, flow cytometry was used to measure changes in mitochondrial membrane potential. Annexin V-FITC/PI staining was used to detect apoptosis, and Western blots were used to detect the expression of Bcl-2/Bax. Fluorescence microscopic observations of axonal growth in NG-108 cells under hypoxic conditions were also performed. Results The hypoxia-preconditioning group maintained mitochondrial cell membrane and crista integrity, and these cells exhibited less edema than the hypoxia group. In addition, the cells in the hypoxia-preconditioning group were found to be in early stages of apoptosis, whereas cells from the hypoxia group were in the later stages of apoptosis. The hypoxia-preconditioning group also had higher levels of Bcl-2/Bax expression and longer NG-108 cell axons than were observed in the hypoxia group. Conclusion Hypoxic preconditioning can improve the physiological state of Schwann cells in a severe hypoxia environment and improve the ability to promote neurite outgrowth. PMID:26509259

  1. Dendritic cell reprogramming by the hypoxic environment.

    PubMed

    Bosco, Maria Carla; Varesio, Luigi

    2012-12-01

    Myeloid dendritic cells (DCs) are professional antigen-presenting cells central to the orchestration of innate and acquired immunity and the maintenance of self-tolerance. The local microenvironment contributes to the regulation of DC development and functions, and deregulated DC responses may result in amplification of inflammation, loss of tolerance, or establishment of immune escape mechanisms. DC generation from monocytic precursors recruited at sites of inflammation, tissue damage, or neoplasia occurs under condition of low partial oxygen pressure (pO(2), hypoxia). We reviewed the literature addressing the phenotypic and functional changes triggered by hypoxia in monocyte-derived immature (i) and mature (m) DCs. The discussion will revolve around in vitro studies of gene expression profile, which give a comprehensive representation of the complexity of response of these cells to low pO(2). The gene expression pattern of hypoxic DC will be discussed to address the question of the relationship with a specific maturation stage. We will summarize data relative to the regulation of the chemotactic network, which points to a role for hypoxia in promoting a migratory phenotype in iDCs and a highly proinflammatory state in mDCs. Current knowledge of the strict regulatory control exerted by hypoxia on the expression of immune-related cell surface receptors will also be addressed, with a particular focus on a newly identified marker of hypoxic DCs endowed with proinflammatory properties. Furthermore, we discuss the literature on the transcription mechanisms underlying hypoxia-regulated gene expression in DCs, which support a major role for the HIF/HRE pathway. Finally, recent advances shedding light on the in vivo influence of the local hypoxic microenvironment on DCs infiltrating the inflamed joints of juvenile idiopathic arthritis patients are outlined. PMID:22901977

  2. Germination under Extreme Hypobaric and Hypoxic Environment

    NASA Astrophysics Data System (ADS)

    Hashimoto, Hirofumi

    Is the agriculture on Mars without a pressured greenhouse dome possible? In order to inves-tigate a possibility of plant cultivation for the space agriculture on Mars, germination rate for six species of plant, Jute, Chrysanthemum, Komatsuna, Cucumber, Okra, and Eggplant under extreme hypobaric and hypoxic condition was measured. Oxygen partial pressure was 1kPa which was equal to 1/100 of normal earth atmosphere. Seeds of Jute and Cucumber were able to germinate in six species. In the case of Jute, germination rate under the oxygen partial pressure of 1kPa was very high, 70

  3. Effects of neonatal hypoxic-ischemic episodes on late seizure outcomes in C57 black mice.

    PubMed

    Peng, Jessie; Li, Ran; Arora, Neha; Lau, Marcus; Lim, Stellar; Wu, Chiping; Eubanks, James H; Zhang, Liang

    2015-03-01

    We examined brain injury and seizures in adult C57 black mice (C57/BL6) that underwent neonatal hypoxic-ischemic (HI) episodes. Mouse pups of 7 days-old underwent a ligation of the right common carotid artery and a subsequent hypoxic challenge (8% O2 for 45min). Post-HI mice were implanted with intracranial electrodes at 2-3 months of age, subjected to behavioral/EEG recordings and hippocampal electrical stimulation in next several months and then euthanized for brain histological assessments at ages of 11-12 months. Histological assessment revealed ipsilateral brain infarctions in 9 post-HI animals. Evident motor seizures were found to occur in only 2 animals with histologically identified cystic infarctions but not in the 21 post-HI animals with or without infarctions. In response to the hippocampal stimulation, post-HI animals were less prone than sham controls to evoked motor seizures. We thus suggest that adult C57 black mice may have low propensity of developing epileptic seizures following the neonatal HI episode. Our present observations may be relevant to future investigation of post-HI epileptogenesis in mouse models. PMID:25769378

  4. Nicotinamide mononucleotide adenylyltransferase promotes hypoxic survival by activating the mitochondrial unfolded protein response

    PubMed Central

    Mao, X R; Kaufman, D M; Crowder, C M

    2016-01-01

    Gain-of-function mutations in the mouse nicotinamide mononucleotide adenylyltransferase type 1 (Nmnat1) produce two remarkable phenotypes: protection against traumatic axonal degeneration and reduced hypoxic brain injury. Despite intensive efforts, the mechanism of Nmnat1 cytoprotection remains elusive. To develop a new model to define this mechanism, we heterologously expressed a mouse Nmnat1 non-nuclear-localized gain-of-function mutant gene (m-nonN-Nmnat1) in the nematode Caenorhabditis elegans and show that it provides protection from both hypoxia-induced animal death and taxol-induced axonal pathology. Additionally, we find that m-nonN-Nmnat1 significantly lengthens C. elegans lifespan. Using the hypoxia-protective phenotype in C. elegans, we performed a candidate screen for genetic suppressors of m-nonN-Nmnat1 cytoprotection. Loss of function in two genes, haf-1 and dve-1, encoding mitochondrial unfolded protein response (mitoUPR) factors were identified as suppressors. M-nonN-Nmnat1 induced a transcriptional reporter of the mitoUPR gene hsp-6 and provided protection from the mitochondrial proteostasis toxin ethidium bromide. M-nonN-Nmnat1 was also protective against axonal degeneration in C. elegans induced by the chemotherapy drug taxol. Taxol markedly reduced basal expression of a mitoUPR reporter; the expression was restored by m-nonN-Nmnat1. Taken together, these data implicate the mitoUPR as a mechanism whereby Nmnat1 protects from hypoxic and axonal injury. PMID:26913604

  5. The role of classical transient receptor potential channels in the regulation of hypoxic pulmonary vasoconstriction.

    PubMed

    Fuchs, B; Dietrich, A; Gudermann, T; Kalwa, H; Grimminger, F; Weissmann, N

    2010-01-01

    Hypoxic pulmonary vasoconstriction (HPV) is an essential mechanism of the lung matching blood perfusion to ventilation during local alveolar hypoxia. HPV thus optimizes pulmonary gas exchange. In contrast chronic and generalized hypoxia leads to pulmonary vascular remodeling with subsequent pulmonary hypertension and right heart hypertrophy. Among other non-selective cation channels, the family of classical transient receptor potential channels (TRPC) has been shown to be expressed in pulmonary arterial smooth muscle cells. Among this family, TRPC6 is essential for the regulation of acute HPV in mice. Against this background, in this chapter we give an overview about the TRPC family and their role in HPV. PMID:20204731

  6. Metabolic plasticity in CLL: adaptation to the hypoxic niche

    PubMed Central

    Koczula, K M; Ludwig, C; Hayden, R; Cronin, L; Pratt, G; Parry, H; Tennant, D; Drayson, M; Bunce, C M; Khanim, F L; Günther, U L

    2016-01-01

    Metabolic transformation in cancer is increasingly well understood. However, little is known about the metabolic responses of cancer cells that permit their survival in different microenvironments. We have used a nuclear magnetic resonance based approach to monitor metabolism in living primary chronic lymphoid leukemia (CLL) cells and to interrogate their real-time metabolic responses to hypoxia. Our studies demonstrate considerable metabolic plasticity in CLL cells. Despite being in oxygenated blood, circulating CLL cells are primed for hypoxia as measured by constitutively low level hypoxia-inducible factor (HIF-1α) activity and modest lactate production from glycolysis. Upon entry to hypoxia we observed rapid upregulation of metabolic rates. CLL cells that had adapted to hypoxia returned to the ‘primed' state when re-oxygenated and again showed the same adaptive response upon secondary exposure to hypoxia. We also observed HIF-1α independent differential utilization of pyruvate in oxygenated and hypoxic conditions. When oxygenated, CLL cells released pyruvate, but in hypoxia imported pyruvate to protect against hypoxia-associated oxidative stress. Finally, we identified a marked association of slower resting glucose and glutamine consumption, and lower alanine and lactate production with Binet A0 stage samples indicating that CLL may be divided into tumors with higher and lower metabolic states that reflect disease stage. PMID:26202928

  7. [STRESS AND INFARCT LIMITING EFFECTS OF EARLY HYPOXIC PRECONDITIONING].

    PubMed

    Lishmanov, Yu B; Maslov, L N; Sementsov, A S; Naryzhnaya, N V; Tsibulnikov, S Yu

    2015-09-01

    It was established that early hypoxic preconditioning is an adaptive state different from eustress and distress. Hypoxic preconditioning has the cross effects, increasing the tolerance of the heart to ischemia-reperfusion and providing antiulcerogenic effect during immobilization stress. PMID:26672158

  8. Prevention of experimental stroke by hypercapnic-hypoxic preconditioning.

    PubMed

    Yakushev, N N; Bespalov, A G; Kulikov, V P

    2008-09-01

    The effectiveness of hypercapnic hypoxic training in the prevention of acute disturbances in cerebral circulation was studied under experimental conditions. Hypercapnic hypoxic training was followed by a significant decrease in the severity of neurological deficit and locomotor and coordination disorders after cerebral ischemic injury. PMID:19240841

  9. Hypoxic adipocytes pattern early heterotopic bone formation.

    PubMed

    Olmsted-Davis, Elizabeth; Gannon, Francis H; Ozen, Mustafa; Ittmann, Michael M; Gugala, Zbigniew; Hipp, John A; Moran, Kevin M; Fouletier-Dilling, Christine M; Schumara-Martin, Shannon; Lindsey, Ronald W; Heggeness, Michael H; Brenner, Malcolm K; Davis, Alan R

    2007-02-01

    The factors contributing to heterotopic ossification, the formation of bone in abnormal soft-tissue locations, are beginning to emerge, but little is known about microenvironmental conditions promoting this often devastating disease. Using a murine model in which endochondral bone formation is triggered in muscle by bone morphogenetic protein 2 (BMP2), we studied changes near the site of injection of BMP2-expressing cells. As early as 24 hours later, brown adipocytes began accumulating in the lesional area. These cells stained positively for pimonidazole and therefore generated hypoxic stress within the target tissue, a prerequisite for the differentiation of stem cells to chondrocytes and subsequent heterotopic bone formation. We propose that aberrant expression of BMPs in soft tissue stimulates production of brown adipocytes, which drive the early steps of heterotopic endochondral ossification by lowering oxygen tension in adjacent tissue, creating the correct environment for chondrogenesis. Results in misty gray lean mutant mice not producing brown fat suggest that white adipocytes convert into fat-oxidizing cells when brown adipocytes are unavailable, providing a compensatory mechanism for generation of a hypoxic microenvironment. Manipulation of the transcriptional control of adipocyte fate in local soft-tissue environments may offer a means to prevent or treat development of bone in extraskeletal sites. PMID:17255330

  10. Hypoxic guard systems do not prevent rapid hypoxic inspired mixture formation.

    PubMed

    De Cooman, Sofie; Schollaert, Caroline; Hendrickx, Jan F A; Peyton, Philip J; Van Zundert, Tom; De Wolf, Andre M

    2015-08-01

    Because a case report and theoretical mass balances suggested that hypoxic guard systems may not prevent the formation of hypoxic inspired mixtures (FIO2 ≤ 21 %) over the clinically used fresh gas flow (FGF) range, we measured FIO2 over a wide range of hypoxic guard limits for O2/N2O and O2/air mixtures. After IRB approval, 16 ASA I-II patients received sevoflurane in either O2/N2O (n = 8) or O2/air (n = 8) using a Zeus(®) anesthesia machine in the conventional mode. After using an 8 L/min FGF with FDO2 = 25% for 10 min, the following hypoxic guard limits were tested for 4 min each, expressed as [total FGF in L/min; FDO2 in %]: [0.3;85], [0.4;65], [0.5;50], [0.7;36], [0.85;30], [1.0;25], [1.25;25], [1.5;25], [2;25], [3;25], [5;25], and [8;25]. In between these [FGF;FDO2] combinations, 8 L/min FGF with 25% O2 was used for 4 min to return to the same baseline FIO2 (25%) before the start of the next combination. This sequence was studied once in each patient receiving O2/air (n = 8), but twice in each patient who received O2/N2O (n = 8) to examine the effect of decreasing N2O uptake over time, resulting in three groups: early O2/N2O, late O2/N2O, and O2/air group. The [FGF;FDO2]-FIO2 relationship was examined. The overall [FGF;FDO2]-FIO2 relationship in the three groups was similar. In all 1, 1.25, and 1.5 L/min FGF groups, FIO2 decreased below 21% in all but one patient; this occurred within 1 min in at least one patient. In the 0.7 L/min O2/air group and the 3 L/min late O2/N2O and O2/air groups, FIO2 decreased below 21% in one patient. Current hypoxic guard systems do not reliably prevent a hypoxic FIO2 with O2/N2O and O2/air mixtures, particularly between 0.7 and 3 L/min. PMID:25270987

  11. Acute Hypoxic Test in Patients with Prediabetes.

    PubMed

    Shatylo, Valerii B; Serebrovska, Tatiana V; Gavalko, Anna V; Egorov, Egor; Korkushko, Oleg V

    2016-06-01

    Shatylo, Valerii B., Tetiana V. Serebrovska, Anna V. Gavalko, Egor Egorov, and Oleg V. Korkushko. Acute hypoxic test in patients with prediabetes. High Alt Med Biol. 17:101-107, 2016.-Prediabetes is a state of impaired carbohydrate metabolism when not all of the symptoms required to label a person as diabetic are present, but blood glucose is higher than in healthy subjects. Recent evidence suggests that intermittent hypoxia training (IHT) might provide a cost-effective strategy for improving metabolic functioning. One of the most important aspects of the successful IHT application is individualized approach to hypoxic dose and regimen prescription. To establish the relationships between indices of carbohydrate metabolism and individual resistance to hypoxia, the acute hypoxic test (AHT, breathing gas mixture with 12% O2 during 20 minutes) was performed in 33 healthy volunteers (mean age, 63.0, range, 44-76; fasting plasma glucose (FPG) less than 5.6 mmol/L and 2 hours postoral glucose tolerance test (OGTT) glycemia less than 7.8 mmol/L) and 30 patients with impaired glucose metabolism (mean age, 65.5, range, 44-75; FPG from 5.6 to 6.9 mmol/L and 2 hours post-OGTT glycemia from 7.8 to 11 mmol/L). Negative correlation was found between the SaO2 level at 20th minute AHT and FPG (r = -0.83; p < 0.01) and insulin (r = -0.27; p < 0.05), as well as 2 hours post-OGTT glucose and insulin levels (r = -0.75 and -0.40, respectively). Longer recovery time and less effective functioning of respiratory and cardiovascular systems were also registered in patients with prediabetes showing that their cardiovascular resilience is impaired compared to normoglycemic controls. These patterns of relationship must be considered when assigning the individual modes of IHT. PMID:27213550

  12. The ion channel transient receptor potential melastatin-2 does not play a role in inflammatory mouse models of chronic obstructive pulmonary diseases

    PubMed Central

    2012-01-01

    Background There is strong evidence that oxidative stress is associated with the pathogenesis of chronic obstructive pulmonary disease (COPD). The transient receptor potential melastatin-2 (TRPM2) is an oxidative stress sensing channel that is expressed in a number of inflammatory cells and therefore it has been suggested that inhibition of TRPM2 could lead to a beneficial effect in COPD patients. In this study, we have investigated the role of TRPM2 in a variety of mouse models of oxidative stress and COPD using TRPM2-deficent mice. Methods Mice were exposed to ozone (3 ppm for 4 h) or lipopolysaccharide (LPS, 0.3 mg/kg, intranasaly). In another model, mice were exposed to tobacco smoke (750 μg/l total wet particulate matter) for 30 min twice a day on three consecutive days. For the exacerbation model, the smoke exposure on the morning of day 3 animals was replaced with intranasal administration of LPS (0.3 mg/kg). Animals were killed 3 and 24 h after the challenge (ozone and LPS model) or 18 h after the last tobacco smoke exposure. In vitro neutrophil chemotaxis and monocyte activation were also studied using cells isolated from wild type and TRPM2-deficient animals. Statistical significance for the in vivo data (P < 0.05) was determined using analysis of variance with Kruskal-Wallis and Dunns multiple comparison test. Results In all models studied, no difference in the bronchoalveolar lavage inflammation could be evidenced when comparing wild type and TRPM2-deficient mice. In addition, no difference could be seen in the lung inflammation as assessed by the measurement of various cytokines/chemokines. Similarly in various in vitro cellular activation assays using isolated neutrophils and monocytes no significant differences could be observed when comparing wild type and TRPM2-deficient mice. Discussion We have shown, in all the models tested, no difference in the development of airway inflammation or cell activation between TRPM2-deficient mice and their wild

  13. Hepatocytes Determine the Hypoxic Microenvironment and Radiosensitivity of Colorectal Cancer Cells Through Production of Nitric Oxide That Targets Mitochondrial Respiration

    SciTech Connect

    Jiang, Heng; Verovski, Valeri N.; Leonard, Wim; Law, Ka Lun; Vermeersch, Marieke; Storme, Guy; Van den Berge, Dirk; Gevaert, Thierry; Sermeus, Alexandra; De Ridder, Mark

    2013-03-01

    Purpose: To determine whether host hepatocytes may reverse hypoxic radioresistance through nitric oxide (NO)-induced oxygen sparing, in a model relevant to colorectal cancer (CRC) liver metastases. Methods and Materials: Hepatocytes and a panel of CRC cells were incubated in a tissue-mimetic coculture system with diffusion-limited oxygenation, and oxygen levels were monitored by an oxygen-sensing fluorescence probe. To activate endogenous NO production, cocultures were exposed to a cytokine mixture, and the expression of inducible nitric oxide synthase was analyzed by reverse transcription–polymerase chain reaction, Western blotting, and NO/nitrite production. The mitochondrial targets of NO were examined by enzymatic activity. To assess hypoxic radioresponse, cocultures were irradiated and reseeded for colonies. Results: Resting hepatocytes consumed 10-40 times more oxygen than mouse CT26 and human DLD-1, HT29, HCT116, and SW480 CRC cells, and thus seemed to be the major effectors of hypoxic conditioning. As a result, hepatocytes caused uniform radioprotection of tumor cells at a 1:1 ratio. Conversely, NO-producing hepatocytes radiosensitized all CRC cell lines more than 1.5-fold, similar to the effect of selective mitochondrial inhibitors. The radiosensitizing effect was associated with a respiratory self-arrest of hepatocytes at the level of aconitase and complex II, which resulted in profound reoxygenation of tumor cells through oxygen sparing. Nitric oxide–producing hepatocytes were at least 10 times more active than NO-producing macrophages to reverse hypoxia-induced radioresistance. Conclusions: Hepatocytes were the major determinants of the hypoxic microenvironment and radioresponse of CRC cells in our model of metabolic hypoxia. We provide evidence that reoxygenation and radiosensitization of hypoxic CRC cells can be achieved through oxygen sparing induced by endogenous NO production in host hepatocytes.

  14. The impact of hypofractionation on simultaneous dose-boosting to hypoxic tumor subvolumes

    SciTech Connect

    Ruggieri, Ruggero; Nahum, Alan E.

    2006-11-15

    In a previous study, the dependence of the therapeutic ratio on the number of fractions (n), including both acute and chronic hypoxia, was investigated for homogeneously irradiated tumors. The present study further develops the model to include simultaneous dose-boosting to the hypoxic tumour subvolumes. The acutely hypoxic (ah) tumor subvolume was partitioned into a large number (10{sup 2}-10{sup 3}) of oxygenation subvolumes, modelled through rectangular pO{sub 2}(t) waves all with the same frequency and fractional time spent below the hypoxic threshold, but with randomly distributed phases. Three quite different assumptions were considered for the effect of prolonged hypoxia on the radiosensitivity ({alpha}) of the chronically hypoxic (ch) clonogens, ranging from equal radiosensitivity to that of the ah-cells to an even greater radiosensitivity than that of the well-oxygenated (ox) cells. The linear-quadratic model, including tumor repopulation, intertumor {alpha}-heterogeneity, and dependence of the oxygen enhancement ratio on the dose per fraction, was adopted for tumor control probability (TCP) computation. To include a consideration of therapeutic ratio, lung irradiation was considered and the mean normalized total lung dose (NTD{sub L}) was used as a risk indicator. For those 1(fr/d){center_dot}5(d/w) schedules yielding 50% TCP with homogeneous irradiation (our reference benchmark), we estimated the gain in TCP and the corresponding NTD{sub L} from dose boosting only the ch-subvolume, both the ah- and the ch-subvolumes, or 50% of the pretreatment tumor volume without specific targeting to tumor hypoxia. For two of the three assumptions for the radiosensitivity of the ch-clonogens, dose-boosting the ch-subvolume was associated with a substantial gain in TCP, and with a trend including minima in NTD{sub L}, for severely hypofractionated schedules only, whereas when dose-boosting both the ah- and the ch-subvolumes a substantial gain in TCP was always obtained

  15. Targeting hypoxic response for cancer therapy

    PubMed Central

    Paolicchi, Elisa; Gemignani, Federica; Krstic-Demonacos, Marija; Dedhar, Shoukat; Mutti, Luciano; Landi, Stefano

    2016-01-01

    Hypoxic tumor microenvironment (HTM) is considered to promote metabolic changes, oncogene activation and epithelial mesenchymal transition, and resistance to chemo- and radio-therapy, all of which are hallmarks of aggressive tumor behavior. Cancer cells within the HTM acquire phenotypic properties that allow them to overcome the lack of energy and nutrients supply within this niche. These phenotypic properties include activation of genes regulating glycolysis, glucose transport, acidosis regulators, angiogenesis, all of which are orchestrated through the activation of the transcription factor, HIF1A, which is an independent marker of poor prognosis. Moreover, during the adaptation to a HTM cancer cells undergo deep changes in mitochondrial functions such as “Warburg effect” and the “reverse Warburg effect”. This review aims to provide an overview of the characteristics of the HTM, with particular focus on novel therapeutic strategies currently in clinical trials, targeting the adaptive response to hypoxia of cancer cells. PMID:26859576

  16. Neuroprotective Strategies after Neonatal Hypoxic Ischemic Encephalopathy

    PubMed Central

    Dixon, Brandon J.; Reis, Cesar; Ho, Wing Mann; Tang, Jiping; Zhang, John H.

    2015-01-01

    Neonatal hypoxic ischemic encephalopathy (HIE) is a devastating disease that primarily causes neuronal and white matter injury and is among the leading cause of death among infants. Currently there are no well-established treatments; thus, it is important to understand the pathophysiology of the disease and elucidate complications that are creating a gap between basic science and clinical translation. In the development of neuroprotective strategies and translation of experimental results in HIE, there are many limitations and challenges to master based on an appropriate study design, drug delivery properties, dosage, and use in neonates. We will identify understudied targets after HIE, as well as neuroprotective molecules that bring hope to future treatments such as melatonin, topiramate, xenon, interferon-beta, stem cell transplantation. This review will also discuss some of the most recent trials being conducted in the clinical setting and evaluate what directions are needed in the future. PMID:26389893

  17. Neuroprotective Strategies after Neonatal Hypoxic Ischemic Encephalopathy.

    PubMed

    Dixon, Brandon J; Reis, Cesar; Ho, Wing Mann; Tang, Jiping; Zhang, John H

    2015-01-01

    Neonatal hypoxic ischemic encephalopathy (HIE) is a devastating disease that primarily causes neuronal and white matter injury and is among the leading cause of death among infants. Currently there are no well-established treatments; thus, it is important to understand the pathophysiology of the disease and elucidate complications that are creating a gap between basic science and clinical translation. In the development of neuroprotective strategies and translation of experimental results in HIE, there are many limitations and challenges to master based on an appropriate study design, drug delivery properties, dosage, and use in neonates. We will identify understudied targets after HIE, as well as neuroprotective molecules that bring hope to future treatments such as melatonin, topiramate, xenon, interferon-beta, stem cell transplantation. This review will also discuss some of the most recent trials being conducted in the clinical setting and evaluate what directions are needed in the future. PMID:26389893

  18. Neuroimaging in Neonatal Hypoxic Ischemic Encephalopathy.

    PubMed

    Krishnan, Pradeep; Shroff, Manohar

    2016-09-01

    Magnetic resonance (MR) imaging is emerging as one of the most important tools in identifying the etiology of neonatal encephalopathy as well as in predicting long-term outcomes. This makes it imperative to have a broader understanding of normal myelination of the neonatal brain on MR imaging and to be familiar with the spectrum of imaging features in ischemic and non-ischemic neonatal encephalopathy. Hypoxic ischemic injury (HIE) is one of the most common causes of neonatal encephalopathy and imaging appearances are influenced by factors such as the stage of maturation of the neonatal brain and severity as well as duration of ischemic insult. Other common causes of neonatal encephalopathy include infectious diseases, congenital disorders and inborn errors of metabolism. PMID:26909496

  19. Chronic hypoxia selectively enhances L- and T-type voltage-dependent Ca2+ channel activity in pulmonary artery by upregulating Cav1.2 and Cav3.2.

    PubMed

    Wan, Jun; Yamamura, Aya; Zimnicka, Adriana M; Voiriot, Guillaume; Smith, Kimberly A; Tang, Haiyang; Ayon, Ramon J; Choudhury, Moumita S R; Ko, Eun A; Wang, Jun; Wang, Chen; Makino, Ayako; Yuan, Jason X-J

    2013-07-15

    Hypoxia-induced pulmonary hypertension (HPH) is characterized by sustained pulmonary vasoconstriction and vascular remodeling, both of which are mediated by pulmonary artery smooth muscle cell (PASMC) contraction and proliferation, respectively. An increase in cytosolic Ca²⁺ concentration ([Ca²⁺]cyt) is a major trigger for pulmonary vasoconstriction and an important stimulus for cell proliferation in PASMCs. Ca²⁺ influx through voltage-dependent Ca²⁺ channels (VDCC) is an important pathway for the regulation of [Ca²⁺]cyt. The potential role for L- and T-type VDCC in the development of HPH is still unclear. Using a hypoxic-induced pulmonary hypertension mouse model, we undertook this study to identify if VDCC in pulmonary artery (PA) are functionally upregulated and determine which type of VDCC are altered in HPH. Mice subjected to chronic hypoxia developed pulmonary hypertension within 4 wk, and high-K⁺- and U-46619-induced contraction of PA was greater in chronic hypoxic mice than that in normoxic control mice. Additionally, we demonstrate that high-K⁺- and U-46619-induced Ca²⁺ influx in PASMC is significantly increased in the hypoxic group. The VDCC activator, Bay K8864, induced greater contraction of the PA of hypoxic mice than in that of normoxic mice in isometric force measurements. L-type and T-type VDCC blockers significantly attenuated absolute contraction of the PA in hypoxic mice. Chronic hypoxia did not increase high-K⁺- and U-46619-induced contraction of mesenteric artery (MA). Compared with MA, PA displayed higher expression of calcium channel voltage-dependent L-type α1C-subunit (Cav1.2) and T-type α1H-subunit (Cav3.2) upon exposure to chronic hypoxia. In conclusion, both L-type and T-type VDCC were functionally upregulated in PA, but not MA, in HPH mice, which could result from selectively increased expression of Cav1.2 and Cav3.2. PMID:23686856

  20. Loss of Interleukin-21 Receptor Activation in Hypoxic Endothelial Cells Impairs Perfusion Recovery after Hindlimb Ischemia

    PubMed Central

    Wang, Tao; Cunningham, Alexis; Dokun, Ayotunde O; Hazarika, Surovi; Houston, Kevin; Chen, Lingdan; Lye, R. John; Spolski, Rosanne; Leonard, Warren J.; Annex, Brian H.

    2016-01-01

    Objective Surgical hindlimb ischemia (HLI) in mice has become a valuable preclinical model to study peripheral arterial disease (PAD). We previously identified that the different phenotypical outcomes following HLI across inbred mouse strains is related a region on the short arm of mouse chromosome 7. The gene coding the interleukin-21 receptor (IL-21R) lies at the peak of association in this region. Approach and Results With quantitative RT-PCR, we found that a mouse strain with a greater ability to up-regulate IL-21R following HLI had better perfusion recovery than a strain with no up-regulation after HLI. Immunofluorescent staining of ischemic hind-limb tissue showed IL-21R expression on endothelial cells (EC) from these C57BL/6 mice. An EC-enriched fraction isolated from ischemic hind-limb muscle showed higher Il-21R levels than an EC-enriched fraction from non-ischemic limbs. In-vitro, human umbilical vein EC (HUVEC) showed elevated IL-21R expression after hypoxia and serum starvation. Under these conditions, IL-21 treatment increased cell viability, decreased cell apoptosis, and augmented tube formation. In-vivo, either knockout Il21r or blocking IL-21 signaling by treating with IL-21R-Fc (fusion protein that blocks IL-21 binding to its receptor) in C57BL/6 mice resulted in less perfusion recovery after HLI. Both in-vitro and in-vivo modulation of the IL-21/IL-21R axis under hypoxic conditions resulted in increasedSTAT3 phosphorylation and a subsequent increase in the BCL-2/BAX ratio. Conclusion Our data indicate that IL-21R up-regulation and ligand activation in hypoxic endothelial cells may help perfusion recovery by limiting/preventing apoptosis and/or favoring cell survival and angiogenesis through the STAT3 pathway. PMID:25838422

  1. Involvement of endothelin-1 in hypoxic pulmonary vasoconstriction in the lamb.

    PubMed Central

    Wang, Y; Coe, Y; Toyoda, O; Coceani, F

    1995-01-01

    1. Using isolated pulmonary resistance vessels from mature fetal lamb and chronically instrumented lambs (8-17 days old), we have examined whether hypoxic pulmonary vasoconstriction is sustained by activation of a constrictor mechanism or suppression of a dilator mechanism. 2. Hypoxia contracted both arteries and veins in vitro, and the contraction was greater with the former. After removing the endothelium, arteries responded faster to hypoxia, but the magnitude of the response remained unchanged. 3. Hypoxic arteries, unlike normally oxygenated arteries, did not contract with either indomethacin (2.8 microM) or N omega-nitro-L-arginine methyl ester (L-NAME, 100 microM). The same vessels relaxed with sodium nitroprusside (SNP, 0.001-10 microM) but not with bradykinin (0.1-100 nM). 4. Endothelin-1 (ET-1, 0.01-10 nM) contracted isolated arteries and veins under normoxic and hypoxic conditions. In both vessels, the contraction was fast in onset and subsidence, and was inhibited by the ETA receptor antagonist BQ123 (1 microM). The ET-1 precursor, big ET-1 (100 nM), also contracted arteries and veins, but compared with ET-1 its action was slower in development. Big ET-1 contraction, unlike ET-1 contraction, was curtailed by the inhibitor of the ET-1-converting enzyme, phosphoramidon (50 microM). 5. ET-1 (0.1-10 nM) had no effect on isolated arteries precontracted with a thromboxane A2 (TXA2) analogue (ONO-11113) and treated with BQ123 (10 microM). Under the same conditions, ET-1 relaxed the veins. Accordingly, in the absence of BQ123 treatment, the selective ETB receptor agonist IRL-1620 (0.1-100 nM) relaxed the contracted veins but not the arteries. 6. BQ123 (10 microM) inhibited the constriction of isolated arteries and veins to hypoxia. Likewise, in the conscious lamb a bolus of BQ123 (0.4 mg kg-1, injected into the pulmonary artery) curtailed the rise in pulmonary vascular resistance (Rpa) brought about by alveolar hypoxia without changing significantly systemic

  2. PI3K/Akt contributes to increased expression of Toll-like receptor 4 in macrophages exposed to hypoxic stress

    SciTech Connect

    Kim, So Young; Jeong, Eunshil; Joung, Sun Myung; Lee, Joo Young

    2012-03-16

    Highlights: Black-Right-Pointing-Pointer Hypoxic stress-induced TLR4 expression is mediated by PI3K/Akt in macrophages. Black-Right-Pointing-Pointer PI3K/Akt regulated HIF-1 activation leading to TLR4 expression. Black-Right-Pointing-Pointer p38 mitogen-activated protein kinase was not involved in TLR4 expression by hypoxic stress. Black-Right-Pointing-Pointer Sulforaphane suppressed hypoxia-mediated TLR4 expression by inhibiting PI3K/Akt. -- Abstract: Toll-like receptors (TLRs) play critical roles in triggering immune and inflammatory responses by detecting invading microbial pathogens and endogenous danger signals. Increased expression of TLR4 is implicated in aggravated inflammatory symptoms in ischemic tissue injury and chronic diseases. Results from our previous study showed that TLR4 expression was upregulated by hypoxic stress mediated by hypoxia-inducible factor-1 (HIF-1) at a transcriptional level in macrophages. In this study, we further investigated the upstream signaling pathway that contributed to the increase of TLR4 expression by hypoxic stress. Either treatment with pharmacological inhibitors of PI3K and Akt or knockdown of Akt expression by siRNA blocked the increase of TLR4 mRNA and protein levels in macrophages exposed to hypoxia and CoCl{sub 2}. Phosphorylation of Akt by hypoxic stress preceded nuclear accumulation of HIF-1{alpha}. A PI3K inhibitor (LY294002) attenuated CoCl{sub 2}-induced nuclear accumulation and transcriptional activation of HIF-1{alpha}. In addition, HIF-1{alpha}-mediated upregulation of TLR4 expression was blocked by LY294002. Furthermore, sulforaphane suppressed hypoxia- and CoCl{sub 2}-induced upregulation of TLR4 mRNA and protein by inhibiting PI3K/Akt activation and the subsequent nuclear accumulation and transcriptional activation of HIF-1{alpha}. However, p38 was not involved in HIF-1{alpha} activation and TLR4 expression induced by hypoxic stress in macrophages. Collectively, our results demonstrate that PI3K

  3. Role of the ERK1/2 Signaling Pathway in Osteogenesis of Rat Tendon-Derived Stem Cells in Normoxic and Hypoxic Cultures

    PubMed Central

    Li, Pei; Xu, Yuan; Gan, Yibo; Song, Lei; Zhang, Chengmin; Wang, Liyuan; Zhou, Qiang

    2016-01-01

    Background: Ectopic ossification and increased vascularization are two common phenomena in the chronic tendinopathic tendon. The increased vascularization usually leads to an elevated local oxygen tension which is one of micro-environments that can influence differentiate status of stem cells. Objective: This study aimed to investigate the osteogenesis capacity of rat tendon-derived stem cells TDSCs (rTDSCs) in normoxic and hypoxic cultures, and to study the role of ERK1/2 signaling pathway in this process. Methods: rTDSCs were subjected to osteogenesis inductive culture in hypoxic (3% O2) and normoxic (20% O2) conditions. The inhibitor U0126 was added along with culture medium to determine the role of ERK1/2 signaling pathway. Cell viability, cell proliferation, alizarin red staining, alkaline phosphatase (AKP) activity, gene expression (ALP, osteocalcin, collagen I and RUNX2) and protein expression (p-ERK1/2 and RUNX2) of osteogenic-cultured rTSDCs were analyzed in this study. Results: Hypoxic and normoxic culture had no effects on cell viability of rTDSCs, whereas the proliferation potential of rTDSCs was significantly increased in hypoxic culture. The osteogenesis capacity of rTDSCs in normoxic culture was significantly promoted compared with hypoxic culture, which was reflected by an increased alizarin red staining intensity, an elevated ALP activity, and the up-regulated gene (ALP, osteocalcin, collagen I and RUNX2) or protein (RUNX2) expression of osteogenic makers. However, the osteogenesis capacity of rTDSCs in both hypoxic and normoxic cultures was attenuated by the inhibitor U0126. Conclusion: Normoxic culture promotes osteogenic differentiation of rTDSCs compared with the hypoxic culture, and the ERK1/2 signaling pathway is involved in this process. PMID:27499695

  4. Dietary nitrate increases arginine availability and protects mitochondrial complex I and energetics in the hypoxic rat heart

    PubMed Central

    Ashmore, Tom; Fernandez, Bernadette O; Branco-Price, Cristina; West, James A; Cowburn, Andrew S; Heather, Lisa C; Griffin, Julian L; Johnson, Randall S; Feelisch, Martin; Murray, Andrew J

    2014-01-01

    Hypoxic exposure is associated with impaired cardiac energetics in humans and altered mitochondrial function, with suppressed complex I-supported respiration, in rat heart. This response might limit reactive oxygen species generation, but at the cost of impaired electron transport chain (ETC) activity. Dietary nitrate supplementation improves mitochondrial efficiency and can promote tissue oxygenation by enhancing blood flow. We therefore hypothesised that ETC dysfunction, impaired energetics and oxidative damage in the hearts of rats exposed to chronic hypoxia could be alleviated by sustained administration of a moderate dose of dietary nitrate. Male Wistar rats (n = 40) were given water supplemented with 0.7 mmol l−1 NaCl (as control) or 0.7 mmol l−1 NaNO3, elevating plasma nitrate levels by 80%, and were exposed to 13% O2 (hypoxia) or normoxia (n = 10 per group) for 14 days. Respiration rates, ETC protein levels, mitochondrial density, ATP content and protein carbonylation were measured in cardiac muscle. Complex I respiration rates and protein levels were 33% lower in hypoxic/NaCl rats compared with normoxic/NaCl controls. Protein carbonylation was 65% higher in hearts of hypoxic rats compared with controls, indicating increased oxidative stress, whilst ATP levels were 62% lower. Respiration rates, complex I protein and activity, protein carbonylation and ATP levels were all fully protected in the hearts of nitrate-supplemented hypoxic rats. Both in normoxia and hypoxia, dietary nitrate suppressed cardiac arginase expression and activity and markedly elevated cardiac l-arginine concentrations, unmasking a novel mechanism of action by which nitrate enhances tissue NO bioavailability. Dietary nitrate therefore alleviates metabolic abnormalities in the hypoxic heart, improving myocardial energetics. PMID:25172947

  5. Classical transient receptor potential channel 6 (TRPC6) is essential for hypoxic pulmonary vasoconstriction and alveolar gas exchange

    PubMed Central

    Weissmann, Norbert; Dietrich, Alexander; Fuchs, Beate; Kalwa, Hermann; Ay, Mahmut; Dumitrascu, Rio; Olschewski, Andrea; Storch, Ursula; Mederos y Schnitzler, Michael; Ghofrani, Hossein Ardeschir; Schermuly, Ralph Theo; Pinkenburg, Olaf; Seeger, Werner; Grimminger, Friedrich; Gudermann, Thomas

    2006-01-01

    Regional alveolar hypoxia causes local vasoconstriction in the lung, shifting blood flow from hypoxic to normoxic areas, thereby maintaining gas exchange. This mechanism is known as hypoxic pulmonary vasoconstriction (HPV). Disturbances in HPV can cause life-threatening hypoxemia whereas chronic hypoxia triggers lung vascular remodeling and pulmonary hypertension. The signaling cascade of this vitally important mechanism is still unresolved. Using transient receptor potential channel 6 (TRPC6)-deficient mice, we show that this channel is a key regulator of acute HPV as this regulatory mechanism was absent in TRPC6−/− mice whereas the pulmonary vasoconstrictor response to the thromboxane mimetic U46619 was unchanged. Accordingly, induction of regional hypoventilation resulted in severe arterial hypoxemia in TRPC6−/− but not in WT mice. This effect was mirrored by a lack of hypoxia-induced cation influx and currents in smooth-muscle cells from precapillary pulmonary arteries (PASMC) of TRPC6−/− mice. In both WT and TRPC6−/− PASMC hypoxia caused diacylglycerol (DAG) accumulation. DAG seems to exert its action via TRPC6, as DAG kinase inhibition provoked a cation influx only in WT but not in TRPC6−/− PASMC. Notably, chronic hypoxia-induced pulmonary hypertension was independent of TRPC6 activity. We conclude that TRPC6 plays a unique and indispensable role in acute hypoxic pulmonary vasoconstriction. Manipulation of TRPC6 function may thus offer a therapeutic strategy for the control of pulmonary hemodynamics and gas exchange. PMID:17142322

  6. Adenosine A2B receptor modulates intestinal barrier function under hypoxic and ischemia/reperfusion conditions

    PubMed Central

    Yang, Yang; Qiu, Yuan; Wang, Wensheng; Xiao, Weidong; Liang, Hongyin; Zhang, Chaojun; Yang, Hanwenbo; Teitelbaum, Daniel H; Sun, Li-Hua; Yang, Hua

    2014-01-01

    Background: Intestinal barrier function failure from ischemia/reperfusion (I/R) and acute hypoxia has been implicated as a critical determinant in the predisposition to intestinal inflammation and a number of inflammatory disorders. Here, we identified the role of Adenosine A2B receptor (A2BAR) in the regulation of intestinal barrier function under I/R and acute hypoxic conditions. Methods: C57BL/6J mice were used, and were randomized into three groups: Sham, I/R, IR+PSB1115 (a specific A2BAR antagonist) groups. After surgery, the small bowel was harvested for immunohistochemical staining, RNA and protein content, and intestinal permeability analyses. Using an epithelial cell culture model, we investigated the influence of hypoxia on the epithelial function, and the role of A2BAR in the expressions of tight junction and epithelial permeability. The expressions of Claudin-1, occludin and ZO-1 were detected by RT-PCR and Western-Blot. Epithelial barrier function was assessed with transepithelial resistance (TER). Results and conclusions: The A2BAR antagonist, PSB1115, significantly increased tight junction protein expression after intestinal I/R or acute hypoxia conditions. PSB1115 also attenuated the disrupted distribution of TJ proteins. Furthermore, inhibition of A2BAR attenuated the decrease in TER induced by I/R or acute hypoxic conditions, and maintained intestinal barrier function. Antagonism of A2BAR activity improves intestinal epithelial structure and barrier function in a mouse model of intestinal I/R and a cell model of acute hypoxia. These findings support a potentially destructive role for A2BAR under intestinal I/R and acute hypoxic conditions. PMID:24966910

  7. [Follow-up of newborns with hypoxic-ischaemic encephalopathy].

    PubMed

    Martínez-Biarge, M; Blanco, D; García-Alix, A; Salas, S

    2014-07-01

    Hypothermia treatment for newborn infants with hypoxic-ischemic encephalopathy reduces the number of neonates who die or have permanent neurological deficits. Although this therapy is now standard of care, neonatal hypoxic-ischaemic encephalopathy still has a significant impact on the child's neurodevelopment and quality of life. Infants with hypoxic-ischaemic encephalopathy should be enrolled in multidisciplinary follow-up programs in order to detect impairments, to initiate early intervention, and to provide counselling and support for families. This article describes the main neurodevelopmental outcomes after term neonatal hypoxic-ischaemic encephalopathy. We offer recommendations for follow-up based on the infant's clinical condition and other prognostic indicators, mainly neonatal neuroimaging. Other aspects, such as palliative care and medico-legal issues, are also briefly discussed. PMID:24290154

  8. Long-Term Overexpression of Hsp70 Does Not Protect against Cardiac Dysfunction and Adverse Remodeling in a MURC Transgenic Mouse Model with Chronic Heart Failure and Atrial Fibrillation.

    PubMed

    Bernardo, Bianca C; Sapra, Geeta; Patterson, Natalie L; Cemerlang, Nelly; Kiriazis, Helen; Ueyama, Tomomi; Febbraio, Mark A; McMullen, Julie R

    2015-01-01

    Previous animal studies had shown that increasing heat shock protein 70 (Hsp70) using a transgenic, gene therapy or pharmacological approach provided cardiac protection in models of acute cardiac stress. Furthermore, clinical studies had reported associations between Hsp70 levels and protection against atrial fibrillation (AF). AF is the most common cardiac arrhythmia presenting in cardiology clinics and is associated with increased rates of heart failure and stroke. Improved therapies for AF and heart failure are urgently required. Despite promising observations in animal studies which targeted Hsp70, we recently reported that increasing Hsp70 was unable to attenuate cardiac dysfunction and pathology in a mouse model which develops heart failure and intermittent AF. Given our somewhat unexpected finding and the extensive literature suggesting Hsp70 provides cardiac protection, it was considered important to assess whether Hsp70 could provide protection in another mouse model of heart failure and AF. The aim of the current study was to determine whether increasing Hsp70 could attenuate adverse cardiac remodeling, cardiac dysfunction and episodes of arrhythmia in a mouse model of heart failure and AF due to overexpression of Muscle-Restricted Coiled-Coil (MURC). Cardiac function and pathology were assessed in mice at approximately 12 months of age. We report here, that chronic overexpression of Hsp70 was unable to provide protection against cardiac dysfunction, conduction abnormalities, fibrosis or characteristic molecular markers of the failing heart. In summary, elevated Hsp70 may provide protection in acute cardiac stress settings, but appears insufficient to protect the heart under chronic cardiac disease conditions. PMID:26660322

  9. Long-Term Overexpression of Hsp70 Does Not Protect against Cardiac Dysfunction and Adverse Remodeling in a MURC Transgenic Mouse Model with Chronic Heart Failure and Atrial Fibrillation

    PubMed Central

    Bernardo, Bianca C.; Sapra, Geeta; Patterson, Natalie L.; Cemerlang, Nelly; Kiriazis, Helen; Ueyama, Tomomi; Febbraio, Mark A.; McMullen, Julie R.

    2015-01-01

    Previous animal studies had shown that increasing heat shock protein 70 (Hsp70) using a transgenic, gene therapy or pharmacological approach provided cardiac protection in models of acute cardiac stress. Furthermore, clinical studies had reported associations between Hsp70 levels and protection against atrial fibrillation (AF). AF is the most common cardiac arrhythmia presenting in cardiology clinics and is associated with increased rates of heart failure and stroke. Improved therapies for AF and heart failure are urgently required. Despite promising observations in animal studies which targeted Hsp70, we recently reported that increasing Hsp70 was unable to attenuate cardiac dysfunction and pathology in a mouse model which develops heart failure and intermittent AF. Given our somewhat unexpected finding and the extensive literature suggesting Hsp70 provides cardiac protection, it was considered important to assess whether Hsp70 could provide protection in another mouse model of heart failure and AF. The aim of the current study was to determine whether increasing Hsp70 could attenuate adverse cardiac remodeling, cardiac dysfunction and episodes of arrhythmia in a mouse model of heart failure and AF due to overexpression of Muscle-Restricted Coiled-Coil (MURC). Cardiac function and pathology were assessed in mice at approximately 12 months of age. We report here, that chronic overexpression of Hsp70 was unable to provide protection against cardiac dysfunction, conduction abnormalities, fibrosis or characteristic molecular markers of the failing heart. In summary, elevated Hsp70 may provide protection in acute cardiac stress settings, but appears insufficient to protect the heart under chronic cardiac disease conditions. PMID:26660322

  10. Ageing, chronic alcohol consumption and folate are determinants of genomic DNA methylation, p16 promoter methylation and the expression of p16 in the mouse colon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Elder age and chronic alcohol consumption are important risk factors for the development of colon cancer. Each factor can alter genomic and gene-specific DNA methylation. This study examined the effects of aging and chronic alcohol consumption on genomic and p16-specific methylation, and p16 express...

  11. Aging and chronic alcohol consumption are determinants of p16 gene expression, genomic DNA methylation and p16 promoter methylation in the mouse colon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Elder age and chronic alcohol consumption are important risk factors for the development of colon cancer. Each factor can alter genomic and gene-specific DNA methylation. This study examined the effects of aging and chronic alcohol consumption on genomic and p16-specific methylation, and p16 express...

  12. Hypoxic pulmonary vasoconstriction, carotid body function and erythropoietin production in adult rats perinatally exposed to hyperoxia

    PubMed Central

    Prieto-Lloret, Jesus; Ramirez, Maria; Olea, Elena; Moral-Sanz, Javier; Cogolludo, Angel; Castañeda, Javier; Yubero, Sara; Agapito, Teresa; Gomez-Niño, Angela; Rocher, Asuncion; Rigual, Ricardo; Obeso, Ana; Perez-Vizcaino, Francisco; González, Constancio

    2015-01-01

    Adult mammalians possess three cell systems that are activated by acute bodily hypoxia: pulmonary artery smooth muscle cells (PASMC), carotid body chemoreceptor cells (CBCC) and erythropoietin (EPO)-producing cells. In rats, chronic perinatal hyperoxia causes permanent carotid body (CB) atrophy and functional alterations of surviving CBCC. There are no studies on PASMC or EPO-producing cells. Our aim is to define possible long-lasting functional changes in PASMC or EPO-producing cells (measured as EPO plasma levels) and, further, to analyse CBCC functional alterations. We used 3- to 4-month-old rats born and reared in a normal atmosphere or exposed to perinatal hyperoxia (55–60% O2 for the last 5–6 days of pregnancy and 4 weeks after birth). Perinatal hyperoxia causes an almost complete loss of hypoxic pulmonary vasoconstriction (HPV), which was correlated with lung oxidative status in early postnatal life and prevented by antioxidant supplementation in the diet. O2-sensitivity of K+ currents in the PASMC of hyperoxic animals is normal, indicating that their inhibition is not sufficient to trigger HPV. Perinatal hyperoxia also abrogated responses elicited by hypoxia on catecholamine and cAMP metabolism in the CB. An increase in EPO plasma levels elicited by hypoxia was identical in hyperoxic and control animals, implying a normal functioning of EPO-producing cells. The loss of HPV observed in adult rats and caused by perinatal hyperoxia, comparable to oxygen therapy in premature infants, might represent a previously unrecognized complication of such a medical intervention capable of aggravating medical conditions such as regional pneumonias, atelectases or general anaesthesia in adult life. Key points Adult animals that have been perinatally exposed to oxygen-rich atmospheres (hyperoxia), recalling those used for oxygen therapy in infants, exhibit a loss of hypoxic pulmonary vasoconstriction, whereas vasoconstriction elicited by depolarizing agents is

  13. Hypoxic acidemia, hyperviscosity, and maternal hypertension do not affect the umbilical arterial velocity waveform in fetal sheep.

    PubMed

    Morrow, R J; Adamson, S L; Bull, S B; Ritchie, J W

    1990-10-01

    The effect of hypoxic acidemia, hyperviscosity, and maternal hypertension on the umbilical arterial velocity waveform was studied in 23 chronically catheterized fetal sheep. Fetal hypoxic acidemia induced by lowering the maternal inspired oxygen concentration (n = 7) caused no change in the ratio of systolic/diastolic blood velocity even when fetal arterial pH was as low as 6.8. Fetal blood hyperviscosity (n = 7) induced by exchange transfusion with packed maternal blood cells increased placental vascular resistance by greater than or equal to 50% but had no significant effect on the systolic/diastolic ratio. Similarly, maternal hypertension induced by intravenous infusion of angiotensin II to the ewe (n = 9) did not affect the systolic/diastolic ratio despite a 50% increase in maternal arterial blood pressure. We conclude that umbilical arterial velocity waveform abnormalities observed in growth-restricted human fetuses are probably not a direct result of fetal hypoxemia or hyperviscosity or maternal hypertension. PMID:2220943

  14. Chronic administration of an HDAC inhibitor treats both neurological and systemic Niemann-Pick type C disease in a mouse model.

    PubMed

    Alam, Md Suhail; Getz, Michelle; Haldar, Kasturi

    2016-02-17

    Histone deacetylase inhibitors (HDACi) are approved for treating rare cancers and are of interest as potential therapies for neurodegenerative disorders. We evaluated a triple combination formulation (TCF) comprising the pan-HDACi vorinostat, the caging agent 2-hydroxypropyl-β-cyclodextrin (HPBCD), and polyethylene glycol (PEG) for treating a mouse model (the Npc1(nmf164) mouse) of Niemann-Pick type C (NPC) disease, a difficult-to-treat cerebellar disorder. Vorinostat alone showed activity in cultured primary cells derived from Npc1(nmf164) mice but did not improve animal survival. However, low-dose, once-weekly intraperitoneal injections of the TCF containing vorinostat increased histone acetylation in the mouse brain, preserved neurites and Purkinje cells, delayed symptoms of neurodegeneration, and extended mouse life span from 4 to almost 9 months. We demonstrate that the TCF boosted the ability of HDACi to cross the blood-brain barrier and was not toxic even when used long term. Further, the TCF enabled dose reduction, which has been a major challenge in HDACi therapy. TCF simultaneously treats neurodegenerative and systemic symptoms of Niemann-Pick type C disease in a mouse model. PMID:26888431

  15. Thalamic mediation of hypoxic respiratory depression in lambs.

    PubMed

    Koos, Brian J; Rajaee, Arezoo; Ibe, Basil; Guerra, Catalina; Kruger, Lawrence

    2016-04-01

    Immaturity of respiratory controllers in preterm infants dispose to recurrent apnea and oxygen deprivation. Accompanying reductions in brain oxygen tensions evoke respiratory depression, potentially exacerbating hypoxemia. Central respiratory depression during moderate hypoxia is revealed in the ventilatory decline following initial augmentation. This study determined whether the thalamic parafascicular nuclear (Pf) complex involved in adult nociception and sensorimotor regulation (Bentivoglio M, Balerecia G, Kruger L.Prog Brain Res87: 53-80, 1991) also becomes a postnatal controller of hypoxic ventilatory decline. Respiratory responses to moderate isocapnic hypoxia were studied in conscious lambs. Hypoxic ventilatory decline was compared with peak augmentation. Pf and/or adjacent thalamic structures were destroyed by the neuron-specific toxin ibotenic acid (IB). IB lesions involving the thalamic Pf abolished hypoxic ventilatory decline. Lesions of adjacent thalamic nuclei that spared Pf and control injections of vehicle failed to blunt hypoxic respiratory depression. Our findings reveal that the thalamic Pf region is a critical controller of hypoxic ventilatory depression and thus a key target for exploring molecular concomitants of forebrain pathways regulating hypoxic ventilatory depression in early development. PMID:26818057

  16. Therapeutic attack of hypoxic cells of solid tumors: presidential address.

    PubMed

    Sartorelli, A C

    1988-02-15

    Hypoxic cells of solid tumors are relatively resistant to therapeutic assault. Studies have demonstrated that oxygen-deficient tumor cells exist in an environment conducive to reductive reactions making hypoxic cells particularly sensitive to bioreductive alkylating agents. Mitomycin C, the prototype bioreductive alkylating agent available for clinical use, is capable of preferentially killing oxygen-deficient cells both in vitro and in vivo. This phenomenon is at least in part the result of differences in the uptake and metabolism of mitomycin C by hypoxic and oxygenated tumor cells, with the ultimate critical lesion being the cross-linking of DNA by the mitomycin antibiotic. The combination of mitomycin C with X-irradiation, to attack hypoxic and oxygenated tumor cell populations, respectively, has led to enhanced antitumor effects in mice bearing solid tumor implants and in patients with cancer of the head and neck. More efficacious kill of hypoxic tumor cells may be possible by the use of dicoumarol in combination with mitomycin or by the use of the related antibiotic porfiromycin. The findings support the use of an agent with specificity for hypoxic tumor cells in potentially curative regimens for solid tumors. PMID:3123053

  17. Individual variation in response to simulated hypoxic stress of rats.

    PubMed

    Ghosh, Dishari; Kumar, Rajesh; Pal, Karan

    2012-10-01

    With an aim to categorize the animals exposed to simulated hypobaric hypoxia and to evaluate the hormonal profile responsible for individual variation in response to hypoxic stress, degree of tolerance to hypobaric hypoxia was measured by exposing the animals to a simulated altitude of 10,668 m at 32 degrees C and animals were categorized as low and high tolerant groups based on their gasping time. The hormonal profiles of these groups were evaluated just after exposure to the test. The results showed a distinct individual difference in response to hypoxic tolerance test. There was a significant increase in plasma norepinephrine concentration in high tolerant group than low tolerant rats. After hypoxic tolerance test, total circulating corticosterone (CORT) level also increased but this was not significant in high tolerant rats as compared to low tolerant rats. Corticosteroid binding globulin (CBG) concentration differ significantly between high and low tolerant groups of rats resulting in significant changes in circulating free corticosterone that in turn may be responsible for individual differences in hypoxic gasping time. Significant differences were also observed in prolactin and testosterone levels of both the groups. The results established the method of differentiating the animals according their response to hypoxic tolerance test. These data indicate that multiple components rather than only plasma glucocorticoid of the stress response are providing a basis for individual differences in physiological responses to hypoxic stress. PMID:23214269

  18. The metal-responsive transcription factor-1 contributes to HIF-1 activation during hypoxic stress

    SciTech Connect

    Murphy, Brian J. . E-mail: brian.murphy@sri.com; Sato, Barbara G.; Dalton, Timothy P.; Laderoute, Keith R.

    2005-11-25

    Hypoxia-inducible factor-1 (HIF-1), the major transcriptional regulator of the mammalian cellular response to low oxygen (hypoxia), is embedded within a complex network of signaling pathways. We have been investigating the importance of another stress-responsive transcription factor, MTF-1, for the adaptation of cells to hypoxia. This article reports that MTF-1 plays a central role in hypoxic cells by contributing to HIF-1 activity. Loss of MTF-1 in transformed Mtf1 null mouse embryonic fibroblasts (MEFs) results in an attenuation of nuclear HIF-1{alpha} protein accumulation, HIF-1 transcriptional activity, and expression of an established HIF-1 target gene, glucose transporter-1 (Glut1). Mtf1 null (Mtf1 KO) MEFs also have constitutively higher levels of both glutathione (GSH) and the rate-limiting enzyme involved in GSH synthesis-glutamate cysteine ligase catalytic subunit-than wild type cells. The altered cellular redox state arising from increased GSH may perturb oxygen-sensing mechanisms in hypoxic Mtf1 KO cells and decrease the accumulation of HIF-1{alpha} protein. Together, these novel findings define a role for MTF-1 in the regulation of HIF-1 activity.

  19. Pulmonary hypoxic vasoconstriction: how strong? How fast?

    NASA Technical Reports Server (NTRS)

    Sheehan, D. W.; Klocke, R. A.; Farhi, L. E.

    1992-01-01

    We have developed a minimally invasive technique for studying regional blood flow in conscious sheep, bypassing the complications of open-chest surgery, flow probes and tracer infusion. We quantitate regional perfusion continuously on the basis of regional clearance of methane (methane is produced in the sheep rumen, enters the circulation and is eliminated nearly completely (greater than 95%) in the lung). Tracheal intubation with a dual-lumen catheter isolates the gas exchange of the right apical lobe (RAL; less than 15% of the lung) from that of the remainder of the lung, which serves as a control (CL). We measure RAL and CL methane elimination by entraining expirates in constant flows, sampled continuously for methane. Results obtained with this technique and from regional oxygen uptake are in excellent agreement. We have found that hypoxic vasoconstriction is far more potent and stable during eucapnic hypoxia than during hypocapnic hypoxia. The time course of the vasoconstriction suggests that many of the data in the literature may have been obtained prior to steady state.

  20. The effects of hypoxic bradycardia and extracellular HCO3(-)/CO2 on hypoxic performance in the eel heart.

    PubMed

    Joyce, William; Simonsen, Maj; Gesser, Hans; Wang, Tobias

    2016-02-01

    During hypoxia, fishes exhibit a characteristic hypoxic bradycardia, the functional significance of which remains debated. Here, we investigated the hypothesis that hypoxic bradycardia primarily safeguards cardiac performance. In preparations from the European eel (Anguilla anguilla), a decrease in stimulation frequency from 40 to 15 beats min(-1), which replicates hypoxic bradycardia in vivo, vastly improved cardiac performance during hypoxia in vitro. As eels display dramatic shifts in extracellular HCO3(-)/CO2, we further investigated the effect this has upon hypoxic cardiac performance. Elevations from 10 mmol l(-1) HCO3(-)/1% CO2 to 40 mmol l(-1) HCO3(-)/4% CO2 had few effects on performance; however, further, but still physiologically relevant, increases to 70 mmol l(-1) HCO3(-)/7% CO2 compromised hypoxia tolerance. We revealed a four-way interaction between HCO3(-)/CO2, contraction frequency, hypoxia and performance over time, whereby the benefit of hypoxic bradycardia was most prolonged at 10 mmol l(-1) HCO3(-)/1% CO2. Together, our data suggest that hypoxic bradycardia greatly benefits cardiac performance, but its significance may be context specific. PMID:26596533

  1. Regulation of angiogenin expression and epithelial-mesenchymal transition by HIF-1α signaling in hypoxic retinal pigment epithelial cells.

    PubMed

    Lai, Kairan; Luo, Chenqi; Zhang, Xiaobo; Ye, Panpan; Zhang, Yidong; He, Jiliang; Yao, Ke

    2016-09-01

    Choroidal neovascularization (CNV) is a major cause of vision loss in many retinal diseases. Hypoxia is determined to be a key inducer of CNV and hypoxia-inducible factor-1 (HIF-1) is an important transcription factor. Epithelial-mesenchymal transition (EMT) and the synthesis of proangiogenic cytokines make great contributions to the development of CNV. In the present study, the role of HIF-1α signaling in the regulation of angiogenin (ANG) expression and EMT in hypoxic retinal pigment epithelial cells was investigated. A significant elevation expression of ANG expression level in a mouse model of laser-induced CNV was demonstrated. In a hypoxic model of ARPE-19, an increased expression level of ANG and induction of EMT accompanied with stabilization and nucleus translocation of HIF-1α. Blockage of HIF-1α signaling resulted in inhibition of high expression of ANG and EMT features. The direct interaction between HIF-1α and ANG promoter region was identified by ChIP-qPCR. The association of RNase 4 mRNA level with HIF-1α signaling was also clarified in APRE-19. Moreover, the exogenous ANG translocated into the nucleus, enhanced 45S rRNA transcription, promoted cell proliferation and tube formation in human retinal microvascular endothelial cells. In conclusion, the hypoxic conditions regulate the expression of ANG and EMT via an activation of HIF-1α signaling. It provides molecular evidence for potential therapy strategies of treating CNV. PMID:27259982

  2. A model to simulate the oxygen distribution in hypoxic tumors for different vascular architectures

    SciTech Connect

    Espinoza, Ignacio; Peschke, Peter; Karger, Christian P.

    2013-08-15

    Purpose: As hypoxic cells are more resistant to photon radiation, it is desirable to obtain information about the oxygen distribution in tumors prior to the radiation treatment. Noninvasive techniques are currently not able to provide reliable oxygenation maps with sufficient spatial resolution; therefore mathematical models may help to simulate microvascular architectures and the resulting oxygen distributions in the surrounding tissue. Here, the authors present a new computer model, which uses the vascular fraction of tumor voxels, in principle measurable noninvasively in vivo, as input parameter for simulating realistic PO2 histograms in tumors, assuming certain 3D vascular architectures.Methods: Oxygen distributions were calculated by solving a reaction-diffusion equation in a reference volume using the particle strength exchange method. Different types of vessel architectures as well as different degrees of vascular heterogeneities are considered. Two types of acute hypoxia (ischemic and hypoxemic) occurring additionally to diffusion-limited (chronic) hypoxia were implemented as well.Results: No statistically significant differences were observed when comparing 2D- and 3D-vessel architectures (p > 0.79 in all cases) and highly heterogeneously distributed linear vessels show good agreement, when comparing with published experimental intervessel distance distributions and PO2 histograms. It could be shown that, if information about additional acute hypoxia is available, its contribution to the hypoxic fraction (HF) can be simulated as well. Increases of 128% and 168% in the HF were obtained when representative cases of ischemic and hypoxemic acute hypoxia, respectively, were considered in the simulations.Conclusions: The presented model is able to simulate realistic microscopic oxygen distributions in tumors assuming reasonable vessel architectures and using the vascular fraction as macroscopic input parameter. The model may be used to generate PO2 histograms

  3. KLF5 mediates vascular remodeling via HIF-1α in hypoxic pulmonary hypertension.

    PubMed

    Li, Xiaochen; He, Yuanzhou; Xu, Yongjian; Huang, Xiaomin; Liu, Jin; Xie, Min; Liu, Xiansheng

    2016-02-15

    Hypoxic pulmonary hypertension (HPH) is characterized by active vasoconstriction and profound vascular remodeling. KLF5, a zinc-finger transcription factor, is involved in the excessive proliferation and apoptotic resistance phenotype associated with monocrotaline-induced pulmonary hypertension. However, the molecular mechanisms of KLF5-mediated pathogenesis of HPH are largely undefined. Adult male Sprague-Dawley rats were exposed to normoxia or hypoxia (10% O2) for 4 wk. Hypoxic rats developed pulmonary arterial remodeling and right ventricular hypertrophy with significantly increased right ventricular systolic pressure. The levels of KLF5 and hypoxia-inducible factor-1α (HIF-1α) were upregulated in distal pulmonary arterial smooth muscle from hypoxic rats. The knockdown of KLF5 via short-hairpin RNA attenuated chronic hypoxia-induced hemodynamic and histological changes in rats. The silencing of either KLF5 or HIF-1α prevented hypoxia-induced (5%) proliferation and migration and promoted apoptosis in human pulmonary artery smooth muscle cells. KLF5 was immunoprecipitated with HIF-1α under hypoxia and acted as an upstream regulator of HIF-1α. The cell cycle regulators cyclin B1 and cyclin D1 and apoptosis-related proteins including bax, bcl-2, survivin, caspase-3, and caspase-9, were involved in the regulation of KLF5/HIF-1α-mediated cell survival. This study demonstrated that KLF5 plays a crucial role in hypoxia-induced vascular remodeling in an HIF-1α-dependent manner and provided a better understanding of the pathogenesis of HPH. PMID:26702149

  4. The role of inflammation in hypoxic pulmonary hypertension: from cellular mechanisms to clinical phenotypes

    PubMed Central

    Poth, Jens M.; Fini, Mehdi A.; Olschewski, Andrea; El Kasmi, Karim C.; Stenmark, Kurt R.

    2014-01-01

    Hypoxic pulmonary hypertension (PH) comprises a heterogeneous group of diseases sharing the common feature of chronic hypoxia-induced pulmonary vascular remodeling. The disease is usually characterized by mild to moderate pulmonary vascular remodeling that is largely thought to be reversible compared with the progressive irreversible disease seen in World Health Organization (WHO) group I disease. However, in these patients, the presence of PH significantly worsens morbidity and mortality. In addition, a small subset of patients with hypoxic PH develop “out-of-proportion” severe pulmonary hypertension characterized by pulmonary vascular remodeling that is irreversible and similar to that in WHO group I disease. In all cases of hypoxia-related vascular remodeling and PH, inflammation, particularly persistent inflammation, is thought to play a role. This review focuses on the effects of hypoxia on pulmonary vascular cells and the signaling pathways involved in the initiation and perpetuation of vascular inflammation, especially as they relate to vascular remodeling and transition to chronic irreversible PH. We hypothesize that the combination of hypoxia and local tissue factors/cytokines (“second hit”) antagonizes tissue homeostatic cellular interactions between mesenchymal cells (fibroblasts and/or smooth muscle cells) and macrophages and arrests these cells in an epigenetically locked and permanently activated proremodeling and proinflammatory phenotype. This aberrant cellular cross-talk between mesenchymal cells and macrophages promotes transition to chronic nonresolving inflammation and vascular remodeling, perpetuating PH. A better understanding of these signaling pathways may lead to the development of specific therapeutic targets, as none are currently available for WHO group III disease. PMID:25416383

  5. δ-Tocotrienol treatment is more effective against hypoxic tumor cells than normoxic cells: potential implications for cancer therapy.

    PubMed

    Shibata, Akira; Nakagawa, Kiyotaka; Tsuduki, Tsuyoshi; Miyazawa, Teruo

    2015-08-01

    Tocotrienols, unsaturated forms of vitamin E, inhibit the proliferation of a variety of cancer cells and suppress angiogenesis. However, the mechanisms underlying those effects on cancer cell growth remain unclear especially under hypoxic conditions. In this study, we demonstrated that δ-tocotrienol (δ-T3) could be used as a novel anticancer agent against human colorectal adenocarcinoma (DLD-1) cells under both normoxic and hypoxic conditions. δ-T3 inhibited the growth of DLD-1 cells in a dose-dependent fashion by inducing cell cycle arrest and apoptosis. This effect was more potent under hypoxic than normoxic conditions. The anticancer effect of δ-T3 was achieved by its up-regulation of cyclin-dependent kinase inhibitors (p21 and p27), the activation of caspases and the suppression of phosphorylation of protein kinase B (Akt) at Thr(308) and Ser(473). In in vivo studies, oral administration of rice bran tocotrienol (RBT3, mainly γ-T3) (10 mg/mouse/day) significantly inhibited tumor growth in nude mice. In tumor analyses, RBT3 activated p21, p27, caspase-3 and caspase-9 and decreased Akt phosphorylation. Furthermore, immunostaining revealed that RBT3 decreased the number of cells positive for CD31/platelet endothelial cell adhesion molecule-1 in microvessels in the tumor. Taken together, these data suggest that tocotrienols are potent antitumor agents capable of inducing apoptosis and inhibiting angiogenesis under both hypoxic and normoxic conditions. Tocotrienols could have significant therapeutic potential in the clinical treatment of tumors. PMID:25979648

  6. Tracking Hypoxic Signaling within Encapsulated Cell Aggregates

    PubMed Central

    Skiles, Matthew L.; Sahai, Suchit; Blanchette, James O.

    2011-01-01

    nutrients, notably oxygen, is therefore reduced and limited by diffusion. This reduced oxygen availability may especially impact β-cells whose insulin secretory function is highly dependent on oxygen11-13. Capsule composition and geometry will also impact diffusion rates and lengths for oxygen. Therefore, we also describe a technique for identifying hypoxic cells within our PEG capsules. Infection of the cells with a recombinant adenovirus allows for a fluorescent signal to be produced when intracellular hypoxia-inducible factor (HIF) pathways are activated14. As HIFs are the primary regulators of the transcriptional response to hypoxia, they represent an ideal target marker for detection of hypoxic signaling15. This approach allows for easy and rapid detection of hypoxic cells. Briefly, the adenovirus has the sequence for a red fluorescent protein (Ds Red DR from Clontech) under the control of a hypoxia-responsive element (HRE) trimer. Stabilization of HIF-1 by low oxygen conditions will drive transcription of the fluorescent protein (Figure 1). Additional details on the construction of this virus have been published previously15. The virus is stored in 10% glycerol at -80° C as many 150 μL aliquots in 1.5 mL centrifuge tubes at a concentration of 3.4 x 1010 pfu/mL. Previous studies in our lab have shown that MIN6 cells encapsulated as aggregates maintain their viability throughout 4 weeks of culture in 20% oxygen. MIN6 aggregates cultured at 2 or 1% oxygen showed both signs of necrotic cells (still about 85-90% viable) by staining with ethidium bromide as well as morphological changes relative to cells in 20% oxygen. The smooth spherical shape of the aggregates displayed at 20% was lost and aggregates appeared more like disorganized groups of cells. While the low oxygen stress does not cause a pronounced drop in viability, it is clearly impacting MIN6 aggregation and function as measured by glucose-stimulated insulin secretion15. Western blot analysis of encapsulated

  7. Tracking hypoxic signaling within encapsulated cell aggregates.

    PubMed

    Skiles, Matthew L; Sahai, Suchit; Blanchette, James O

    2011-01-01

    , is therefore reduced and limited by diffusion. This reduced oxygen availability may especially impact β-cells whose insulin secretory function is highly dependent on oxygen. Capsule composition and geometry will also impact diffusion rates and lengths for oxygen. Therefore, we also describe a technique for identifying hypoxic cells within our PEG capsules. Infection of the cells with a recombinant adenovirus allows for a fluorescent signal to be produced when intracellular hypoxia-inducible factor (HIF) pathways are activated. As HIFs are the primary regulators of the transcriptional response to hypoxia, they represent an ideal target marker for detection of hypoxic signaling. This approach allows for easy and rapid detection of hypoxic cells. Briefly, the adenovirus has the sequence for a red fluorescent protein (Ds Red DR from Clontech) under the control of a hypoxia-responsive element (HRE) trimer. Stabilization of HIF-1 by low oxygen conditions will drive transcription of the fluorescent protein (Figure 1). Additional details on the construction of this virus have been published previously. The virus is stored in 10% glycerol at -80° C as many 150 μL aliquots in 1.5 mL centrifuge tubes at a concentration of 3.4 x 10(10) pfu/mL. Previous studies in our lab have shown that MIN6 cells encapsulated as aggregates maintain their viability throughout 4 weeks of culture in 20% oxygen. MIN6 aggregates cultured at 2 or 1% oxygen showed both signs of necrotic cells (still about 85-90% viable) by staining with ethidium bromide as well as morphological changes relative to cells in 20% oxygen. The smooth spherical shape of the aggregates displayed at 20% was lost and aggregates appeared more like disorganized groups of cells. While the low oxygen stress does not cause a pronounced drop in viability, it is clearly impacting MIN6 aggregation and function as measured by glucose-stimulated insulin secretion. Western blot analysis of encapsulated cells in 20% and 1% oxygen also

  8. Chronic oral or intraarticular administration of docosahexaenoic acid reduces nociception and knee edema and improves functional outcomes in a mouse model of Complete Freund’s Adjuvant–induced knee arthritis

    PubMed Central

    2014-01-01

    Introduction Clinical and preclinical studies have shown that supplementation with ω-3 polyunsaturated fatty acids (ω-3 PUFAs) reduce joint destruction and inflammation present in rheumatoid arthritis (RA). However, the effects of individual ω-3 PUFAs on chronic arthritic pain have not been evaluated to date. Thus, our aim in this study was to examine whether purified docosahexaenoic acid (DHA, an ω-3 PUFA) reduces spontaneous pain-related behavior and knee edema and improves functional outcomes in a mouse model of knee arthritis. Methods Unilateral arthritis was induced by multiple injections of Complete Freund’s Adjuvant (CFA) into the right knee joints of male ICR adult mice. Mice that received CFA injections were then chronically treated from day 15 until day 25 post–initial CFA injection with oral DHA (10, 30 and 100 mg/kg daily) or intraarticular DHA (25 and 50 μg/joint twice weekly). Spontaneous flinching of the injected extremity (considered as spontaneous pain-related behavior), vertical rearing and horizontal exploratory activity (considered as functional outcomes) and knee edema were assessed. To determine whether an endogenous opioid mechanism was involved in the therapeutic effect of DHA, naloxone (NLX, an opioid receptor antagonist, 3 mg/kg subcutaneously) was administered in arthritic mice chronically treated with DHA (30 mg/kg by mouth) at day 25 post–CFA injection. Results The intraarticular CFA injections resulted in increasing spontaneous flinching and knee edema of the ipsilateral extremity as well as worsening functional outcomes as time progressed. Chronic administration of DHA, given either orally or intraarticularly, significantly improved horizontal exploratory activity and reduced flinching behavior and knee edema in a dose-dependent manner. Administration of NLX did not reverse the antinociceptive effect of DHA. Conclusions To the best of our knowledge, this report is the first to demonstrate DHA’s antinociceptive and

  9. The effect of PCO2 on hypoxic pulmonary vasoconstriction.

    PubMed

    Noble, W H; Kay, J C; Fisher, J A

    1981-09-01

    Lung areas with a low V/Q ratio cause hypoxaemia. The low alveolar oxygen concentration may cause local hypoxic pulmonary vasoconstriction (HPV) which reduces perfusion, raises the V/Q ratio, and hence reduces the tendency to a low PaO2. By changing PCO2, the HPV response can be altered. We examined this relationship in anaesthetized dogs by using a tracheal divider to separate hypoxic (nitrogen ventilated) from oxygenated (100 per cent oxygen ventilated) lung. Relative perfusion was assessed from total 133Xe exhaled from each lung area after intravenous infusions. When PaCO2 was changed by changing ventilation, we found that an increasing PaCO2 increased HPV and also PaO2. At a PaCO2 of 3.3 kPa, HPV was abolished and PaO2 fell. We also changed PaCO2 by altering PICO2 to one or both lung areas while ventilation remained constant throughout the experiment. Again as PaCO2 increased, HPV and PaCO2 increased. When PaCO2 fell and end tidal carbon dioxide in the hypoxic lung (PETCO2) remained elevated by maintaining PICO2 in the hypoxic lung and removing CO2 from the oxygenated lung) HPV was maintained. Thus it is the alveolar concentration of CO2 in the hypoxic lung which is important in modifying HPV. We conclude that in this model a low PETCO2 (3.3 kPa) in hypoxic lung will reduce HPV, and will result in more severe hypoxaemia. This may have relevance in both anaesthetized and intensive care unit patients when a higher PaO2 may be obtained by increasing hypoxic lung PETCO2. The effect of PETCO2 on PaO2 will be influenced by other variables, but when hypoventilated or hypoxic exist, increasing PETCO2 may reinforce hypoxic pulmonary vasoconstriction and thus may increase PaO2. PMID:6793220

  10. Parasagittal lesions and ulegyria in hypoxic-ischemic encephalopathy: neuroimaging findings and review of the pathogenesis.

    PubMed

    Nikas, Ioannis; Dermentzoglou, Vasiliki; Theofanopoulou, Maria; Theodoropoulos, Vasilios

    2008-01-01

    Hypoxic-ischemic brain injury is a very important neurological problem of the perinatal period and a major cause of chronic disability later in childhood. The subsequent neurological deficits are a variety of motor defects-especially spasticity but also choreoathetosis, dystonia and ataxia, often grouped together as "cerebral palsy," mental retardation, and seizures. The gestational age determines the neuropathology of the brain injury. One of the patterns of hypoxic-ischemic encephalopathy, typically affecting full-term infants, consists of parasagittal lesions and ulegyria. The aim of this study is to describe the magnetic resonance imaging (MRI) features and discuss the "suggested" pathogenetic mechanisms of this pattern, which affects the cortex and the white matter in a mainly parasagittal distribution; in this type of brain injury, the damage usually involves the deeper sulcal portion while sparing the apex, thus resulting in the so-called mushroom gyri characteristic ulegyric pattern. We discuss the MRI findings of parasagittal lesions and ulegyria in the brain examinations of 14 patients with a clinical history of perinatal hypoxia/anoxia presenting with mental retardation, seizures, and cerebral palsy. Differential diagnosis from polymicrogyria is discussed. PMID:18160553

  11. NLP-1: a DNA intercalating hypoxic cell radiosensitizer and cytotoxin

    SciTech Connect

    Panicucci, R.; Heal, R.; Laderoute, K.; Cowan, D.; McClelland, R.A.; Rauth, A.M.

    1989-04-01

    The 2-nitroimidazole linked phenanthridine, NLP-1 (5-(3-(2-nitro-1-imidazoyl)-propyl)-phenanthridinium bromide), was synthesized with the rationale of targeting the nitroimidazole to DNA via the phenanthridine ring. The drug is soluble in aqueous solution (greater than 25 mM) and stable at room temperature. It binds to DNA with a binding constant 1/30 that of ethidium bromide. At a concentration of 0.5 mM, NLP-1 is 8 times more toxic to hypoxic than aerobic cells at 37 degrees C. This concentration is 40 times less than the concentration of misonidazole, a non-intercalating 2-nitroimidazole, required for the same degree of hypoxic cell toxicity. The toxicity of NLP-1 is reduced at least 10-fold at 0 degrees C. Its ability to radiosensitize hypoxic cells is similar to misonidazole at 0 degrees C. Thus the putative targeting of the 2-nitroimidazole, NLP-1, to DNA, via its phenanthridine group, enhances its hypoxic toxicity, but not its radiosensitizing ability under the present test conditions. NLP-1 represents a lead compound for intercalating 2-nitroimidazoles with selective toxicity for hypoxic cells.

  12. Psychological strain: examining the effect of hypoxic bedrest and confinement.

    PubMed

    Stavrou, Nektarios A M; McDonnell, Adam C; Eiken, Ola; Mekjavic, Igor B

    2015-02-01

    The aim was to assess the effect of a 10-day exposure to the environmental stressors anticipated in future lunar habitats on indices of psychological strain. In addition to the reduced gravity of the Moon, future habitats on the Moon will likely maintain a hypobaric hypoxic environment. The hypobaric environment will eliminate the need for long decompression profiles prior to each extra-vehicular activity. We investigated the indices of psychological strain during three 10-day conditions, designed to assess the separate and combined effects of inactivity/unloading and normobaric hypoxia on several physiological systems. Eleven male participants underwent three 10-day campaigns in a randomised manner: 1) normobaric normoxic bed rest (NBR), 2) normobaric hypoxic bed rest (HBR) and 3) normobaric hypoxic ambulatory confinement (HAMB). The most negative psychological profile appeared on day 10 of the HBR and HAMB (hypoxic) conditions. Concomitantly, a decrease in positive emotions was observed from baseline to day 10 of the HBR and NBR conditions. Thus, confinement in a hypoxic environment seems to exert a negative effect on an individual's psychological mood. PMID:25484354

  13. Phosphorescence Monitoring of Hypoxic Microenvironment in Solid-Tumors to Evaluate Chemotherapeutic Effects Using the Hypoxia-Sensitive Iridium (III) Coordination Compound

    PubMed Central

    Shang, Jin; Ma, Jingwen; Wang, Rong; Deng, Lei; Guo, Youmin; Zhong, Fan; Bai, Mingfeng; Zhang, Shaojuan; Wu, Daocheng

    2015-01-01

    Objectives To utilize phosphorescence to monitor hypoxic microenvironment in solid-tumors and investigate cancer chemotherapeutic effects in vivo. Methods A hypoxia-sensitive probe named BTP was used to monitor hypoxic microenvironment in solid-tumors. The low-dose metronomic treatment with cisplatin was used in anti-angiogenetic chemotherapeutic programs. The phosphorescence properties of BTP were detected by a spectrofluorometer. BTP cytotoxicity utilized cell necrosis and apoptosis, which were evaluated by trypan blue dye exclusion and Hoechst33342 plus propidium iodide assays. Tumor-bearing mouse models of colon adenocarcinoma were used for tumor imaging in vivo. Monitoring of the hypoxic microenvironment in tumors was performed with a Maestro 2 fluorescence imaging system. Tumor tissues in each group were harvested regularly and treated with pathological hematoxylin and eosin and immunohistochemical staining to confirm imaging results. Results BTP did not feature obvious cytotoxicity for cells, and tumor growth in low-dose metronomic cisplatin treated mice was significantly inhibited by chemotherapy. Hypoxic levels significantly increased due to cisplatin, as proven by the expression level of related proteins. Phosphorescence intensity in the tumors of mice in the cisplatin group was stronger and showed higher contrast than that in tumors of saline treated mice. Conclusions We develop a useful phosphorescence method to evaluate the chemotherapeutic effects of cisplatin. The proposed method shows potential as a phosphorescence imaging approach for evaluating chemotherapeutic effects in vivo, especially anti-angiogenesis. PMID:25786221

  14. Role of glutamate and serotonin on the hypoxic ventilatory response in high-altitude-adapted plateau Pika.

    PubMed

    Bai, Zhenzhong; Voituron, Nicolas; Wuren, Tana; Jeton, Florine; Jin, Guoen; Marchant, Dominique; Richalet, Jean-Paul; Ge, Ri-Li; Pichon, Aurélien P

    2015-07-01

    The highland "plateau Pika" is considered to be adapted to chronic hypoxia. We hypothesized that glutamate N-methyl-D-aspartate (NMDA) and non-NMDA receptors, nitric oxide (NO) synthase, and serotonin are involved in hypoxic ventilatory response (HVR) in Pikas. We tested the effects of NMDA (memantine) and non-NMDA receptors (DNQX) antagonists, NO synthase inhibitor (L-NAME), and selective serotonin reuptake inhibitors (fluoxetine) on ventilation and HVR in Pikas. Ventilatory parameters were measured before and after drug (or vehicle) injections in conscious Pikas at their natural living altitude (PIO2 86 mmHg) and after a hypoxic challenge (PIO2 57 mmHg, 3 min) to assess the influence of peripheral chemoreceptor on HVR. Minute ventilation (VI) and tidal volume (Vt) increased during hypoxic challenge after vehicle injection, whereas the Ti/Ttot ratio remained unchanged. The increase in VI and Vt observed with vehicle at PIO2-57, when compared with PIO2-86, was inhibited after memantine and fluoxetine injection, whereas the DNQX injection increased HVR. At PIO2-57, L-NAME induced an increase in the Ti/Ttot ratio when compared with vehicle. Therefore, the glutamate through NMDA-R/AMPA receptor bindings and serotonin pathway are implicated at the peripheral chemoreceptor level in HVR in Pikas. However, NO influences the ventilatory pattern of Pikas at their habitual living altitude. PMID:25890014

  15. Enhanced non-eupneic breathing following hypoxic, hypercapnic or hypoxic-hypercapnic gas challenges in conscious mice

    PubMed Central

    Getsy, Paulina M.; Davis, Jesse; Coffee, Gregory A.; May, Walter J.; Palmer, Lisa A.; Strohl, Kingman P.; Lewis, Stephen J.

    2014-01-01

    C57BL6 mice display non-eupneic breathing and spontaneous apneas during wakefulness and sleep as well as markedly disordered breathing following cessation of a hypoxic challenge. We examined whether (1) C57BL6 mice display marked non-eupneic breathing following hypercapnic or hypoxic-hypercapnic challenges, and (2) compared the post-hypoxia changes in non-eupneic breathing of C57BL6 mice to those of B6AF1 (57BL6 dam × A/J sire) and Swiss-Webster mice, which display different ventilatory responses than C57BL6 mice. C57BL6 mice displayed marked increases in respiratory frequency and non-eupneic breathing upon return to room-air after hypoxic (10% O2, 90% N2), hypercapnic (5% CO2, 21% O2, 74% N2) and hypoxic-hypercapnic (10% O2, 5% CO2, 85% N2) challenges. B6AF1 mice displayed less tachypnea and reduced non-eupneic breathing post-hypoxia, whereas Swiss-Webster mice displayed robust tachypnea with minimal increases in non-eupneic breathing post-hypoxia. These studies demonstrate that non-eupneic breathing increases after physiologically-relevant hypoxic-hypercapnic challenge in C57BL6 mice and suggest that further studies with these and B6AF1 and Swiss-Webster mice will help define the genetics of non-eupneic breathing. PMID:25242462

  16. Hypoxic tumor microenvironment: Opportunities to develop targeted therapies.

    PubMed

    Patel, Akhil; Sant, Shilpa

    2016-01-01

    In recent years, there has been great progress in the understanding of tumor biology and its surrounding microenvironment. Solid tumors create regions with low oxygen levels, generally termed as hypoxic regions. These hypoxic areas offer a tremendous opportunity to develop targeted therapies. Hypoxia is not a random by-product of the cellular milieu due to uncontrolled tumor growth; rather it is a constantly evolving participant in overall tumor growth and fate. This article reviews current trends and recent advances in drug therapies and delivery systems targeting hypoxia in the tumor microenvironment. In the first part, we give an account of important physicochemical changes and signaling pathways activated in the hypoxic microenvironment. This is then followed by various treatment strategies including hypoxia-sensitive signaling pathways and approaches to develop hypoxia-targeted drug delivery systems. PMID:27143654

  17. Advancing hypoxic training in team sports: from intermittent hypoxic training to repeated sprint training in hypoxia

    PubMed Central

    Faiss, Raphaël; Girard, Olivier; Millet, Grégoire P

    2013-01-01

    Over the past two decades, intermittent hypoxic training (IHT), that is, a method where athletes live at or near sea level but train under hypoxic conditions, has gained unprecedented popularity. By adding the stress of hypoxia during ‘aerobic’ or ‘anaerobic’ interval training, it is believed that IHT would potentiate greater performance improvements compared to similar training at sea level. A thorough analysis of studies including IHT, however, leads to strikingly poor benefits for sea-level performance improvement, compared to the same training method performed in normoxia. Despite the positive molecular adaptations observed after various IHT modalities, the characteristics of optimal training stimulus in hypoxia are still unclear and their functional translation in terms of whole-body performance enhancement is minimal. To overcome some of the inherent limitations of IHT (lower training stimulus due to hypoxia), recent studies have successfully investigated a new training method based on the repetition of short (<30 s) ‘all-out’ sprints with incomplete recoveries in hypoxia, the so-called repeated sprint training in hypoxia (RSH). The aims of the present review are therefore threefold: first, to summarise the main mechanisms for interval training and repeated sprint training in normoxia. Second, to critically analyse the results of the studies involving high-intensity exercises performed in hypoxia for sea-level performance enhancement by differentiating IHT and RSH. Third, to discuss the potential mechanisms underpinning the effectiveness of those methods, and their inherent limitations, along with the new research avenues surrounding this topic. PMID:24282207

  18. GENE EXPRESSION PROFILING OF MOUSE SKIN AND PAPILLOMAS FOLLOWING CHRONIC EXPOSURE TO MONOMETHYLARSONOUS ACID IN K6/ODC TRANSGENIC MICE

    EPA Science Inventory

    Methylarsonous acid [MMA(III)], a common metabolite of inorganic arsenic metabolism, increases tumor frequency in the skin of K6/ODC transgenic mice following a chronic exposure. To characterize gene expression profiles predictive of MMA(III) exposure and mode of action of carcin...

  19. Exercise-induced oxidative stress and hypoxic exercise recovery.

    PubMed

    Ballmann, Christopher; McGinnis, Graham; Peters, Bridget; Slivka, Dustin; Cuddy, John; Hailes, Walter; Dumke, Charles; Ruby, Brent; Quindry, John

    2014-04-01

    Hypoxia due to altitude diminishes performance and alters exercise oxidative stress responses. While oxidative stress and exercise are well studied, the independent impact of hypoxia on exercise recovery remains unknown. Accordingly, we investigated hypoxic recovery effects on post-exercise oxidative stress. Physically active males (n = 12) performed normoxic cycle ergometer exercise consisting of ten high:low intensity intervals, 20 min at moderate intensity, and 6 h recovery at 975 m (normoxic) or simulated 5,000 m (hypoxic chamber) in a randomized counter-balanced cross-over design. Oxygen saturation was monitored via finger pulse oximetry. Blood plasma obtained pre- (Pre), post- (Post), 2 h post- (2Hr), 4 h post- (4Hr), and 6 h (6Hr) post-exercise was assayed for Ferric Reducing Ability of Plasma (FRAP), Trolox Equivalent Antioxidant Capacity (TEAC), Lipid Hydroperoxides (LOOH), and Protein Carbonyls (PC). Biopsies from the vastus lateralis obtained Pre and 6Hr were analyzed by real-time PCR quantify expression of Heme oxygenase 1 (HMOX1), Superoxide Dismutase 2 (SOD2), and Nuclear factor (euthyroid-derived2)-like factor (NFE2L2). PCs were not altered between trials, but a time effect (13 % Post-2Hr increase, p = 0.044) indicated exercise-induced blood oxidative stress. Plasma LOOH revealed only a time effect (p = 0.041), including a 120 % Post-4Hr increase. TEAC values were elevated in normoxic recovery versus hypoxic recovery. FRAP values were higher 6Hr (p = 0.045) in normoxic versus hypoxic recovery. Exercise elevated gene expression of NFE2L2 (20 % increase, p = 0.001) and SOD2 (42 % increase, p = 0.003), but hypoxic recovery abolished this response. Data indicate that recovery in a hypoxic environment, independent of exercise, may alter exercise adaptations to oxidative stress and metabolism. PMID:24384982

  20. Adenosine receptor antagonist and augmented vasodilation during hypoxic exercise.

    PubMed

    Casey, Darren P; Madery, Brandon D; Pike, Tasha L; Eisenach, John H; Dietz, Niki M; Joyner, Michael J; Wilkins, Brad W

    2009-10-01

    We tested the hypothesis that adenosine contributes to augmented skeletal muscle vasodilation during hypoxic exercise. In separate protocols, subjects performed incremental rhythmic forearm exercise (10% and 20% of maximum) during normoxia and normocapnic hypoxia (80% arterial O2 saturation). In protocol 1 (n = 8), subjects received an intra-arterial administration of saline (control) and aminophylline (adenosine receptor antagonist). In protocol 2 (n = 10), subjects received intra-arterial phentolamine (alpha-adrenoceptor antagonist) and combined phentolamine and aminophylline administration. Forearm vascular conductance (FVC; in ml x min(-1).100 mmHg(-1)) was calculated from forearm blood flow (in ml/min) and blood pressure (in mmHg). In protocol 1, the change in FVC (DeltaFVC; change from normoxic baseline) during hypoxic exercise with saline was 172 +/- 29 and 314 +/- 34 ml x min(-1) x 100 mmHg(-1) (10% and 20%, respectively). Aminophylline administration did not affect DeltaFVC during hypoxic exercise at 10% (190 +/- 29 ml x min(-1)x100 mmHg(-1), P = 0.4) or 20% (287 +/- 48 ml x min(-1) x 100 mmHg(-1), P = 0.3). In protocol 2, DeltaFVC due to hypoxic exercise with phentolamine infusion was 313 +/- 30 and 453 +/- 41 ml x min(-1) x 100 mmHg(-1) (10% and 20% respectively). DeltaFVC was similar at 10% (352 +/- 39 ml min(-1) x 100 mmHg(-1), P = 0.8) and 20% (528 +/- 45 ml x min(-1) x 100 mmHg(-1), P = 0.2) hypoxic exercise with combined phentolamine and aminophylline. In contrast, DeltaFVC to exogenous adenosine was reduced by aminophylline administration in both protocols (P < 0.05 for both). These observations suggest that adenosine receptor activation is not obligatory for the augmented hyperemia during hypoxic exercise in humans. PMID:19661449

  1. Microbial mineralization of dichloroethene and vinyl chloride under hypoxic conditions

    USGS Publications Warehouse

    Bradley, Paul M.; Chapelle, Francis H.

    2011-01-01

    Mineralization of 14C-radiolabled vinyl chloride ([1,2-14C] VC) and cis-dichloroethene ([1,2-14C] cis-DCE) under hypoxic (initial dissolved oxygen (DO) concentrations about 0.1 mg/L) and nominally anoxic (DO minimum detection limit = 0.01 mg/L) was examined in chloroethene-exposed sediments from two groundwater and two surface water sites. The results show significant VC and dichloroethene (DCE) mineralization under hypoxic conditions. All the sample treatments exhibited pseudo-first-order kinetics for DCE and VC mineralization over an extended range of substrate concentrations. First-order rates for VC mineralization were approximately 1 to 2 orders of magnitude higher in hypoxic groundwater sediment treatments and at least three times higher in hypoxic surface water sediment treatments than in the respective anoxic treatments. For VC, oxygen-linked processes accounted for 65 to 85% of mineralization at DO concentrations below 0.1 mg/L, and 14CO2 was the only degradation product observed in VC treatments under hypoxic conditions. Because the lower detection limit for DO concentrations measured in the field is typically 0.1 to 0.5 mg/L, these results indicate that oxygen-linked VC and DCE biodegradation can be significant under field conditions that appear anoxic. Furthermore, because rates of VC mineralization exceeded rates of DCE mineralization under hypoxic conditions, DCE accumulation without concomitant accumulation of VC may not be evidence of a DCE degradative “stall” in chloroethene plumes. Significantly, mineralization of VC above the level that could reasonably be attributed to residual DO contamination was also observed in several nominally anoxic (DO minimum detection limit = 0.01 mg/L) microcosm treatments.

  2. Roles of ASIC3, TRPV1, and NaV1.8 in the transition from acute to chronic pain in a mouse model of fibromyalgia

    PubMed Central

    2014-01-01

    Background Tissue acidosis is effective in causing chronic muscle pain. However, how muscle nociceptors contribute to the transition from acute to chronic pain is largely unknown. Results Here we showed that a single intramuscular acid injection induced a priming effect on muscle nociceptors of mice. The primed muscle nociceptors were plastic and permitted the development of long-lasting chronic hyperalgesia induced by a second acid insult. The plastic changes of muscle nociceptors were modality-specific and required the activation of acid-sensing ion channel 3 (ASIC3) or transient receptor potential cation channel V1 (TRPV1). Activation of ASIC3 was associated with increased activity of tetrodotoxin (TTX)-sensitive voltage-gated sodium channels but not protein kinase Cϵ (PKCϵ) in isolectin B4 (IB4)-negative muscle nociceptors. In contrast, increased activity of TTX-resistant voltage-gated sodium channels with ASIC3 or TRPV1 activation in NaV1.8-positive muscle nociceptors was required for the development of chronic hyperalgesia. Accordingly, compared to wild type mice, NaV1.8-null mice showed briefer acid-induced hyperalgesia (5 days vs. >27 days). Conclusion ASIC3 activation may manifest a new type of nociceptor priming in IB4-negative muscle nociceptors. The activation of ASIC3 and TRPV1 as well as enhanced NaV1.8 activity are essential for the development of long-lasting hyperalgesia in acid-induced, chronic, widespread muscle pain. PMID:24957987

  3. Chemical composition of rainbow trout urine following acute hypoxic stress

    USGS Publications Warehouse

    Hunn, Joseph B.

    1969-01-01

    Rainbow trout (Salmo gairdnerii) were anesthetized with MS-222, catheterized, and introduced into urine collecting chambers. Twenty-four hours after introduction, a 4-hour accumulation of urine was collected to serve as the control. Water flow to the chambers was then discontinued for 30 minutes during which the oxygen content of the water exiting in the chamber dropped from 4.9 to 2.8 mg/l. Following this hypoxic stress fresh water was restored and accumulated urine samples were taken for analysis at 1, 4, and 20 hours post-hypoxic stress. Rainbow trout excrete abnormally high concentrations of Na, K, Mg, Cl, and inorganic PO4 following hypoxia.

  4. Homogentisate 1-2-Dioxygenase Downregulation in the Chronic Persistence of Pseudomonas aeruginosa Australian Epidemic Strain-1 in the CF Lung

    PubMed Central

    Harmer, Christopher J.; Wynn, Matthew; Pinto, Rachel; Cordwell, Stuart; Rose, Barbara R.; Harbour, Colin; Triccas, James A.; Manos, Jim

    2015-01-01

    Some Pseudomonas aeruginosa strains including Australian Epidemic Strain-1 (AES-1 or AUS-01) cause persistent chronic infection in cystic fibrosis (CF) patients, with greater morbidity and mortality. Factors conferring persistence are largely unknown. Previously we analysed the transcriptomes of AES-1 grown in Luria broth, nematode growth medium for Caenorhabditis elegans assay (both aerobic) and artificial sputum medium (mainly hypoxic). Transcriptional comparisons included chronic AES-1 strains against PAO1 and acute AES-1 (AES-1R) against its chronic isogen (AES-1M), isolated 10.5 years apart from a CF patient and not eradicated in the meantime. Prominent amongst genes downregulated in AES-1M in all comparisons was homogentisate-1-2-dioxygenase (hmgA); an oxygen-dependent gene known to be mutationally deactivated in many chronic infection strains of P. aeruginosa. To investigate if hmgA downregulation and deactivation gave similar virulence persistence profiles, a hmgA mutant made in UCBPP-PA14 utilising RedS-recombinase and AES-1M were assessed in the C. elegans virulence assay, and the C57BL/6 mouse for pulmonary colonisation and TNF-α response. In C. elegans, hmgA deactivation resulted in significantly increased PA14 virulence while hmgA downregulation reduced AES-1M virulence. AES-1M was significantly more persistent in mouse lung and showed a significant increase in TNF-α (p<0.0001), sustained even with no detectable bacteria. PA14ΔhmgA did not show increased TNF-α. This study suggests that hmgA may have a role in P. aeruginosa persistence in chronic infection and the results provide a starting point for clarifying the role of hmgA in chronic AES-1. PMID:26252386

  5. Homogentisate 1-2-Dioxygenase Downregulation in the Chronic Persistence of Pseudomonas aeruginosa Australian Epidemic Strain-1 in the CF Lung.

    PubMed

    Harmer, Christopher J; Wynn, Matthew; Pinto, Rachel; Cordwell, Stuart; Rose, Barbara R; Harbour, Colin; Triccas, James A; Manos, Jim

    2015-01-01

    Some Pseudomonas aeruginosa strains including Australian Epidemic Strain-1 (AES-1 or AUS-01) cause persistent chronic infection in cystic fibrosis (CF) patients, with greater morbidity and mortality. Factors conferring persistence are largely unknown. Previously we analysed the transcriptomes of AES-1 grown in Luria broth, nematode growth medium for Caenorhabditis elegans assay (both aerobic) and artificial sputum medium (mainly hypoxic). Transcriptional comparisons included chronic AES-1 strains against PAO1 and acute AES-1 (AES-1R) against its chronic isogen (AES-1M), isolated 10.5 years apart from a CF patient and not eradicated in the meantime. Prominent amongst genes downregulated in AES-1M in all comparisons was homogentisate-1-2-dioxygenase (hmgA); an oxygen-dependent gene known to be mutationally deactivated in many chronic infection strains of P. aeruginosa. To investigate if hmgA downregulation and deactivation gave similar virulence persistence profiles, a hmgA mutant made in UCBPP-PA14 utilising RedS-recombinase and AES-1M were assessed in the C. elegans virulence assay, and the C57BL/6 mouse for pulmonary colonisation and TNF-α response. In C. elegans, hmgA deactivation resulted in significantly increased PA14 virulence while hmgA downregulation reduced AES-1M virulence. AES-1M was significantly more persistent in mouse lung and showed a significant increase in TNF-α (p<0.0001), sustained even with no detectable bacteria. PA14ΔhmgA did not show increased TNF-α. This study suggests that hmgA may have a role in P. aeruginosa persistence in chronic infection and the results provide a starting point for clarifying the role of hmgA in chronic AES-1. PMID:26252386

  6. Notch Activation of Ca(2+) Signaling in the Development of Hypoxic Pulmonary Vasoconstriction and Pulmonary Hypertension.

    PubMed

    Smith, Kimberly A; Voiriot, Guillaume; Tang, Haiyang; Fraidenburg, Dustin R; Song, Shanshan; Yamamura, Hisao; Yamamura, Aya; Guo, Qiang; Wan, Jun; Pohl, Nicole M; Tauseef, Mohammad; Bodmer, Rolf; Ocorr, Karen; Thistlethwaite, Patricia A; Haddad, Gabriel G; Powell, Frank L; Makino, Ayako; Mehta, Dolly; Yuan, Jason X-J

    2015-09-01

    Hypoxic pulmonary vasoconstriction (HPV) is an important physiological response that optimizes the ventilation/perfusion ratio. Chronic hypoxia causes vascular remodeling, which is central to the pathogenesis of hypoxia-induced pulmonary hypertension (HPH). We have previously shown that Notch3 is up-regulated in HPH and that activation of Notch signaling enhances store-operated Ca(2+) entry (SOCE), an important mechanism that contributes to pulmonary arterial smooth muscle cell (PASMC) proliferation and contraction. Here, we investigate the role of Notch signaling in HPV and hypoxia-induced enhancement of SOCE. We examined SOCE in human PASMCs exposed to hypoxia and pulmonary arterial pressure in mice using the isolated perfused/ventilated lung method. Wild-type and canonical transient receptor potential (TRPC) 6(-/-) mice were exposed to chronic hypoxia to induce HPH. Inhibition of Notch signaling with a γ-secretase inhibitor attenuates hypoxia-enhanced SOCE in PASMCs and hypoxia-induced increase in pulmonary arterial pressure. Our results demonstrate that hypoxia activates Notch signaling and up-regulates TRPC6 channels. Additionally, treatment with a Notch ligand can mimic hypoxic responses. Finally, inhibition of TRPC6, either pharmacologically or genetically, attenuates HPV, hypoxia-enhanced SOCE, and the development of HPH. These results demonstrate that hypoxia-induced activation of Notch signaling mediates HPV and the development of HPH via functional activation and up-regulation of TRPC6 channels. Understanding the molecular mechanisms that regulate cytosolic free Ca(2+) concentration and PASMC proliferation is critical to elucidation of the pathogenesis of HPH. Targeting Notch regulation of TRPC6 will be beneficial in the development of novel therapies for pulmonary hypertension associated with hypoxia. PMID:25569851

  7. Dietary palmitate and linoleate oxidations, oxidative stress, and DNA damage differ according to season in mouse lemurs exposed to a chronic food deprivation.

    PubMed

    Giroud, Sylvain; Perret, Martine; Gilbert, Caroline; Zahariev, Alexandre; Goudable, Joëlle; Le Maho, Yvon; Oudart, Hugues; Momken, Iman; Aujard, Fabienne; Blanc, Stéphane

    2009-10-01

    This study investigated the extent to which the increase in torpor expression in the grey mouse lemur, due to graded food restriction, is modulated by a trade-off between a whole body sparing of polyunsaturated dietary fatty acids and the related oxidative stress generated during daily torpor. We measured changes in torpor frequency, total energy expenditure (TEE), linoleate (polyunsaturated fatty acid) and palmitate (saturated fatty acid) oxidation, hexanoyl-lysine (HEL; the product of linoleate peroxidation), and 8-hydroxydeoxyguanosine (8OHdG; a marker of DNA damage). Animals under summer-acclimated long days (LD) or winter-acclimated short days (SD) were exposed to a 40% (LD40 and SD40) and 80% (LD80 and SD80) 35-day calorie restriction (CR). During CR, all groups reduced their body mass, but LD80 animals reached survival-threatened levels at day 22 and were then excluded from the CR trial. Only SD mouse lemurs increased their torpor frequency with CR and displayed a decrease in their TEE adjusted for fat-free mass. After CR, SD40 mouse lemurs shifted the dietary fatty acid oxidation toward palmitate and spared linoleate. Such a shift was not observed in LD animals and during severe CR, during which oxidation of both dietary fatty acids was increased. Concomitantly, HEL increased in both LD40 and SD80 groups, whereas DNA damage was only seen in SD80 food-restricted animals. HEL correlated positively with linoleate oxidation confirming in vivo the substrate/product relationship demonstrated in vitro, and negatively with TEE adjusted for fat-free mass, suggesting higher oxidative stress associated with increased torpor expression. This suggests a seasonal-dependant, cost-benefit trade-off between maximizing torpor propensity and minimizing oxidative stress that is associated with a shift toward sparing of dietary polyunsaturated fatty acids that is dependent upon the expression of a winter phenotype. PMID:19625694

  8. Effect of the sphingosine kinase 1 selective inhibitor, PF-543 on arterial and cardiac remodelling in a hypoxic model of pulmonary arterial hypertension.

    PubMed

    MacRitchie, Neil; Volpert, Giora; Al Washih, Mohammed; Watson, David G; Futerman, Anthony H; Kennedy, Simon; Pyne, Susan; Pyne, Nigel J

    2016-08-01

    Recent studies have demonstrated that the expression of sphingosine kinase 1, the enzyme that catalyses formation of the bioactive lipid, sphingosine 1-phosphate, is increased in lungs from patients with pulmonary arterial hypertension. In addition, Sk1(-/-) mice are protected from hypoxic-induced pulmonary arterial hypertension. Therefore, we assessed the effect of the sphingosine kinase 1 selective inhibitor, PF-543 and a sphingosine kinase 1/ceramide synthase inhibitor, RB-005 on pulmonary and cardiac remodelling in a mouse hypoxic model of pulmonary arterial hypertension. Administration of the potent sphingosine kinase 1 inhibitor, PF-543 in a mouse hypoxic model of pulmonary hypertension had no effect on vascular remodelling but reduced right ventricular hypertrophy. The latter was associated with a significant reduction in cardiomyocyte death. The protection involves a reduction in the expression of p53 (that promotes cardiomyocyte death) and an increase in the expression of anti-oxidant nuclear factor (erythroid-derived 2)-like 2 (Nrf-2). In contrast, RB-005 lacked effects on right ventricular hypertrophy, suggesting that sphingosine kinase 1 inhibition might be nullified by concurrent inhibition of ceramide synthase. Therefore, our findings with PF-543 suggest an important role for sphingosine kinase 1 in the development of hypertrophy in pulmonary arterial hypertension. PMID:27063355

  9. Increased expression of the Vesicular Glutamate Transporter-1 (VGLUT1) in the prefrontal cortex correlates with differential vulnerability to chronic stress in various mouse strains: effects of fluoxetine and MK-801.

    PubMed

    Farley, Séverine; Dumas, Sylvie; El Mestikawy, Salah; Giros, Bruno

    2012-01-01

    Major depression is a chronic psychiatric illness that is highly prevalent and disabling. The available medications are ineffective for many patients suggesting that differents molecular pathways could be specifically altered in the unresponsive patients. Recently, the glutamatergic system has emerged as a target in the research on depression and acute NMDA receptor blockade has been shown to produce strong antidepressant effects. We have studied the adaptations of four mice strains (C57BL/6, DBA/2, C3H and BALB/c) to a chronic unpredictable stress protocol, a widely used model of depression in rodents. BALB/c mice displayed strikingly different behavioral and neurochemical adaptations compared to the other strains tested, suggesting that different molecular pathways are involved in their specific vulnerability. They became hyperactive during the dark period, anhedonic-like and displayed no alterations in the tail suspension test (TST). After chronic stress, only the BALB/c displayed an increased frontocortical VGLUT1 expression which is suggestive of a dysregulation of their prefrontal glutamatergic system, and no BDNF mRNA alteration, although the acute stress modulation of this mRNA is similar to the other strains. Chronic administration of an antagonist of NMDA receptors, MK-801, induced antidepressant-like effects in the TST for stressed BALB/c, but was ineffective for the hyperactivity and anhedonia-like behavior, in contrast to fluoxetine. Chronic MK-801 was totally inactive on the behavior of stressed C57BL/6 mice. MK-801, but not fluoxetine, inhibited the VGLUT1 prefrontal increase in BALB/c. Fluoxetine increased VGLUT1 and BDNF mRNA expression in the hippocampus of the C57BL/6 but not in the BALB/c strain, suggesting a different reactivity in-between strain to both stress and antidepressant. Interestingly enough, the BDNF or VGLUT1 increase is not necessary to reverse the stress induced behavioral alterations in our experimental settings. This observation

  10. Can targeting glutamate receptors with long-term heat acclimation improve outcomes following hypoxic injury?

    PubMed Central

    Ely, Brett R; Brunt, Vienna E; Minson, Christopher T

    2015-01-01

    Long-term heat acclimation appears to improve tolerance to hypoxic insults in various tissues, including brain, providing a promising avenue to improve functional outcomes following cerebrovascular events. Glutamate discharge is implicated in dysfunction following hypoxic stress and thus, targeting glutamate receptors with heat acclimation could improve cognitive outcomes following hypoxic injury. PMID:27227003

  11. Satellite-based empirical models linking river plume dynamics with hypoxic area andvolume

    EPA Science Inventory

    Satellite-based empirical models explaining hypoxic area and volume variation were developed for the seasonally hypoxic (O2 < 2 mg L−1) northern Gulf of Mexico adjacent to the Mississippi River. Annual variations in midsummer hypoxic area and ...

  12. Lactobacillus rhamnosus GG supernatant promotes intestinal barrier function, balances Treg and TH17 cells and ameliorates hepatic injury in a mouse model of chronic-binge alcohol feeding.

    PubMed

    Chen, Rui-Cong; Xu, Lan-Man; Du, Shan-Jie; Huang, Si-Si; Wu, He; Dong, Jia-Jia; Huang, Jian-Rong; Wang, Xiao-Dong; Feng, Wen-Ke; Chen, Yong-Ping

    2016-01-22

    Impaired intestinal barrier function plays a critical role in alcohol-induced hepatic injury, and the subsequent excessive absorbed endotoxin and bacterial translocation activate the immune response that aggravates the liver injury. Lactobacillus rhamnosus GG supernatant (LGG-s) has been suggested to improve intestinal barrier function and alleviate the liver injury induced by chronic and binge alcohol consumption, but the underlying mechanisms are still not clear. In this study, chronic-binge alcohol fed model was used to determine the effects of LGG-s on the prevention of alcoholic liver disease in C57BL/6 mice and investigate underlying mechanisms. Mice were fed Lieber-DeCarli diet containing 5% alcohol for 10 days, and one dose of alcohol was gavaged on Day 11. In one group, LGG-s was supplemented along with alcohol. Control mice were fed isocaloric diet. Nine hours later the mice were sacrificed for analysis. Chronic-binge alcohol exposure induced an elevation in liver enzymes, steatosis and morphology changes, while LGG-s supplementation attenuated these changes. Treatment with LGG-s significantly improved intestinal barrier function reflected by increased mRNA expression of tight junction (TJ) proteins and villus-crypt histology in ileum, and decreased Escherichia coli (E. coli) protein level in liver. Importantly, flow cytometry analysis showed that alcohol reduced Treg cell population while increased TH17 cell population as well as IL-17 secretion, which was reversed by LGG-s administration. In conclusion, our findings indicate that LGG-s is effective in preventing chronic-binge alcohol exposure-induced liver injury and shed a light on the importance of the balance of Treg and TH17 cells in the role of LGG-s application. PMID:26617183

  13. Acute and chronic cocaine differentially alter the subcellular distribution of AMPA GluR1 subunits in region-specific neurons within the mouse ventral tegmental area

    PubMed Central

    Lane, D.A.; Jaferi, A.; Kreek, M.J.; Pickel, V.M.

    2010-01-01

    Cocaine administration increases AMPA GluR1 expression and receptor-mediated activation of the ventral tegmental area (VTA). Functionality is determined, however, by surface availability of these receptors in transmitter- and VTA-region-specific neurons, which may also be affected by cocaine. To test this hypothesis, we used electron microscopic immunolabeling of AMPA GluR1 subunits and tyrosine hydroxylase (TH; the enzyme needed for dopamine synthesis), in the cortical-associated parabrachial (PB) and in the limbic-associated paranigral (PN) VTA of adult male C57BL/6 mice receiving either a single injection (acute) or repeated escalating-doses for 14 days (chronic) of cocaine. Acute cocaine resulted in opposing VTA-region-specific changes in TH-containing dopaminergic dendrites. TH-labeled dendrites within the PB VTA showed increased cytoplasmic GluR1 immunogold particle density consistent with decreased AMPA receptor-mediated glutamatergic transmission. Conversely, TH-labeled dendrites within the PN VTA showed greater surface expression of GluR1 with increases in both synaptic and plasmalemmal GluR1 immunogold density after a single injection of cocaine. These changes diminished in both VTA subregions after chronic cocaine administration. In contrast, non-TH-containing (presumably GABAergic) dendrites showed VTA-region-specific changes only after repeated cocaine administration such that synaptic GluR1 decreased in the PB, but increased in the PN VTA. Taken together, these findings provide ultrastructural evidence suggesting that chronic cocaine not only reverses the respective depression and facilitation of mesocortical (PB) and mesolimbic (PN) dopaminergic neurons elicited by acute cocaine, but also differentially affects synaptic availability of these receptors in non-dopaminergic neurons of each region. These adaptations may contribute to increased cocaine seeking/relapse and decreased reward that is reported with chronic cocaine use. PMID:20553819

  14. Chronic pancreatitis

    MedlinePlus

    Chronic pancreatitis - chronic; Pancreatitis - chronic - discharge; Pancreatic insufficiency - chronic; Acute pancreatitis - chronic ... abuse over many years. Repeated episodes of acute pancreatitis can lead to chronic pancreatitis. Genetics may be ...

  15. Evaluation of the contribution of chronic skin irritation and selected compositional parameters to the tumorigenicity of petroleum middle distillates in mouse skin.

    PubMed

    Freeman, J J; Federici, T M; McKee, R H

    1993-07-28

    Two-year skin carcinogenicity studies were conducted in C3H mice to assess the effects of irritation and selected compositional parameters on the carcinogenic potential of four petroleum liquids. Three samples (lightly refined paraffinic oil, LRPO; lightly hydrodesulfurized specialty oil, LHSO; jet fuel, JF) can be generically classified as middle distillates, i.e. distillation occurs between 350 and 700 degrees F (175-370 degrees C). The fourth sample was a Steam Cracked Gas Oil (SCGO) that distilled within the same range. In studies that assess the effects of irritation on tumorigenicity, LRPO was tested undiluted or was diluted to 50% and 25% in either mineral oil (which eliminated irritation of the skin) or toluene (which did not). Undiluted LRPO elicited tumors in 8% of the mice. Both dilution procedures eliminated tumorigenic potential. Thus, it was possible to maintain a visible level of skin irritation equivalent to that elicited by undiluted LRPO without inducing tumors. SCGO elicited a chronic irritant state grossly equivalent to LRPO but was not tumorigenic. Jet Fuel A (JF) was tested undiluted using both a standard skin painting protocol and an intermittent dosing schedule in which treatment was suspended periodically to allow skin irritation to resolve. The standard treatment protocol of JF resulted in both marked skin irritation and tumors in 44% of the mice. However, using the intermittent schedule, the tumor yield was reduced to 2%. Collectively these data demonstrate that tumor formation is not a necessary sequelae to chronic skin irritation. Conversely, prevention of a marked chronic irritant state was accompanied by decreased tumor yield. These data suggest that the chronic irritant state may be a necessary but not sufficient condition for tumor formation. In studies to assess the effects of compositional parameters, a lightly hydrodesulfurized specialty oil (LHSO) similar to LRPO but refined to have negligible levels of sulfur compounds (3 ppm

  16. Pentoxifylline Alleviates Perinatal Hypoxic-Ischemia-Induced Short-term Memory Impairment by Suppressing Apoptosis in the Hippocampus of Rat Pups

    PubMed Central

    2016-01-01

    Purpose: Perinatal hypoxic-ischemic brain damage is a major cause of acute mortality and chronic neurologic morbidity in infants and children. We investigated the effects of pentoxifylline, a methylxanthine derivative and type-4 phosphodiesterase inhibitor, on short-term memory and apoptotic neuronal cell death in the hippocampus following perinatal hypoxic-ischemia in newborn rats. Methods: We used a step-down avoidance task to evaluate short-term memory and 3ʹ-5ʹ-cyclic adenosine monophosphate (cAMP) assay to detect cAMP levels. We evaluated apoptosis using a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay for evidence of DNA fragmentation, immunohistochemistry for caspase-3 levels, and western blot for Bcl-2 and Bax. Results: Perinatal hypoxic-ischemic injury increased apoptotic cell death in the hippocampus, resulting in impaired short-term memory with decreased cAMP levels. Pentoxifylline treatment improved short-term memory by suppressing apoptotic cell death in the hippocampus with elevated cAMP levels. Conclusions: Pentoxifylline ameliorated perinatal hypoxic-ischemia in rat pups. This alleviating effect could be ascribed to the inhibition apoptosis due to increased cAMP production by pentoxifylline. PMID:27377942

  17. Adaptation of iron requirement to hypoxic conditions at high altitude.

    PubMed

    Gassmann, Max; Muckenthaler, Martina U

    2015-12-15

    Adequate acclimatization time to enable adjustment to hypoxic conditions is one of the most important aspects for mountaineers ascending to high altitude. Accordingly, most reviews emphasize mechanisms that cope with reduced oxygen supply. However, during sojourns to high altitude adjustment to elevated iron demand is equally critical. Thus in this review we focus on the interaction between oxygen and iron homeostasis. We review the role of iron 1) in the oxygen sensing process and erythropoietin (Epo) synthesis, 2) in gene expression control mediated by the hypoxia-inducible factor-2 (HIF-2), and 3) as an oxygen carrier in hemoglobin, myoglobin, and cytochromes. The blood hormone Epo that is abundantly expressed by the kidney under hypoxic conditions stimulates erythropoiesis in the bone marrow, a process requiring high iron levels. To ensure that sufficient iron is provided, Epo-controlled erythroferrone that is expressed in erythroid precursor cells acts in the liver to reduce expression of the iron hormone hepcidin. Consequently, suppression of hepcidin allows for elevated iron release from storage organs and enhanced absorption of dietary iron by enterocytes. As recently observed in sojourners at high altitude, however, iron uptake may be hampered by reduced appetite and gastrointestinal bleeding. Reduced iron availability, as observed in a hypoxic mountaineer, enhances hypoxia-induced pulmonary hypertension and may contribute to other hypoxia-related diseases. Overall, adequate systemic iron availability is an important prerequisite to adjust to high-altitude hypoxia and may have additional implications for disease-related hypoxic conditions. PMID:26183475

  18. MODULATION OF HYPOXIC PULMONARY VASOCONSTRICTION BY ERYTHROCYTIC NITRIC OXIDE

    EPA Science Inventory

    Abstract
    American Heart Association 2001

    Modulation of Hypoxic Pulmonary Vasoconstriction by Erythrocytic NO
    McMahon TJ1, Gow AJ1, Huang YCT4, Stamler JS1,2,3
    Departments of Medicine1 and Biochemistry2, and Howard Hughes Medical Institute3,
    Duke University Med...

  19. Study for Germination Under Extreme Hypobaric and Hypoxic Condition

    NASA Astrophysics Data System (ADS)

    Hashimoto, H.

    2010-04-01

    In order to investigate a possibility of plant cultivation for the space agriculture on Mars, germination rate for six species of plant under extreme hypobaric and hypoxic condition was measured. As a result, seeds of Jute and Cucumber were able to germinate in six species.

  20. Nitrous oxide emissions from the Gulf of Mexico Hypoxic Zone

    EPA Science Inventory

    The production of nitrous oxide (N2O), a potent greenhouse gas, in hypoxic coastal zones remains poorly characterized due to a lack of data, though large nitrogen inputs and deoxygenation typical of these systems create the potential for large N2O emissions. We report the first N...

  1. Perinatal hypoxic-ischemic brain damage: evolution of an animal model.

    PubMed

    Vannucci, Robert C; Vannucci, Susan J

    2005-01-01

    Early research in the Vannucci laboratory prior to 1981 focused largely on brain energy metabolism in the developing rat. At that time, there was no experimental model to study the effects of perinatal hypoxia-ischemia in the rodent, despite the tremendous need to investigate the pathophysiology of perinatal asphyxial brain damage in infants. Accordingly, we developed such a model in the postnatal day 7 rat, using a modification of the Levine preparation in the adult rat. Rat pups underwent unilateral common carotid artery ligation followed by exposure to systemic hypoxia (8% oxygen) at a constant temperature of 37 degrees C. Brain damage, seen histologically, was generally confined to the cerebral hemisphere ipsilateral to the arterial occlusion, and consisted of selective neuronal death or infarction, depending on the duration of the systemic hypoxia. Tissue injury was observed in the cerebral cortex, hippocampus, striatum, and thalamus. Subcortical and periventricular white matter injury was also observed. This model was originally described in the Annals of Neurology in 1981, and during the more than 20 years since that publication numerous investigations utilizing the model have been conducted in our laboratories as well as laboratories around the world. Cerebral blood flow and metabolic correlates have been fully characterized. Physiologic and pharmacologic manipulations have been applied to the model in search of neuroprotective strategies. More recently, molecular biologic alterations during and following the hypoxic-ischemic stress have been ascertained and the model has been adapted to the immature mouse for specific use in genetically altered animals. As predicted in the original article, the model has proven useful for the study of the short- and long-term effects of hypoxic-ischemic brain damage on motor activity, behavior, seizure incidence, and the process of maturation in the brain and other organ systems. PMID:16046840

  2. Chemotherapeutic attack of hypoxic tumor cells by the bioreductive alkylating agent mitomycin C.

    PubMed

    Keyes, S R; Heimbrook, D C; Fracasso, P M; Rockwell, S; Sligar, S G; Sartorelli, A C

    1985-01-01

    Since the cure of solid tumors is limited by the presence of cells with low oxygen contents, we have approached the development of treatment regimens and of new drugs for these tumors by investigating agents which are preferentially bioactivated under hypoxia. Major emphasis has been directed at studying the mode of action of the mitomycin antibiotics, as bioreductive alkylating agents. Using primarily the EMT6 mouse mammary carcinoma as a solid tumor model, we have found that mitomycin C and porfiromycin are preferentially toxic to cells with low oxygen contents. The mitomycin analog BMY-25282 is more toxic to hypoxic cells than are mitomycin C and porfiromycin; however, unlike these antibiotics, BMY-25282 is preferentially toxic to well-oxygenated cells. With these three mitomycins, we have observed a correlation between cytotoxicity to hypoxic cells, the rate of generation of reactive products, and the redox potentials of the drugs. Investigations of the enzymes in EMT6 cells that could possibly activate mitomycin C have revealed that cytochrome P-450 and xanthine oxidase are not present in measurable quantities and therefore are not responsible for activation of mitomycin C. Activities representative of NADPH-cytochrome c reductase and DT-diaphorase are present in these neoplastic cells. Comparison of these enzymatic activities in EMT6, CHO, and V79 cells with the rate of generation of reactive products under hypoxia shows a direct correlation between these two parameters, but there is no quantitative correlation between these two parameters and the amount of cytotoxicity. Use of purified NADPH-cytochrome c reductase and inhibitors of this enzyme demonstrated that NADPH-cytochrome c reductase can activate mitomycin C, but that it is probably not the only enzyme participating in this bioactivation in EMT6 cells. The DT-diaphorase inhibitor dicoumarol was employed to show that this enzyme is not involved in the activation of mitomycin C to a cytotoxic agent

  3. A long-awaited discovery: hypoxia prevents mouse cells from undergoing spontaneous p53-dependent transformation.

    PubMed

    Prockop, Darwin J

    2012-10-01

    A recent publication by Phinney and his associates (1) has presented a discovery for which the field of cell biology has been waiting for more than half a century: a protocol that makes it possible to expand mouse cells in culture without the cells spontaneously transforming. Amazing though it seems, the secret is simply to grow the cells under hypoxic conditions. PMID:22909278

  4. Chronic Pancreatitis and Systemic Inflammatory Response Syndrome Prevent Impact of Chemotherapy with Gemcitabine in a Genetically Engineered Mouse Model of Pancreatic Cancer12

    PubMed Central

    Knoop, Richard F.; Sparn, Moritz; Waldmann, Jens; Plassmeier, Lars; Bartsch, Detlef K.; Lauth, Matthias; Hudemann, Christoph; Fendrich, Volker

    2014-01-01

    BACKGROUND AND AIMS BACKGROUND AND AIMSGemcitabine is the standard therapy for patients with pancreatic cancer with metastatic disease. Patients with metastatic pancreatic cancer presenting with increased values of C-reactive protein do not respond to gemcitabine. So far, no studies have evaluated the correlation between chronic pancreatitis, systemic inflammatory response syndrome, and the loss of chemotherapeutic benefit. METHODS Pdx-1-Cre;LSL-KrasG12D/+;LSL-Trp53R172H/+ mice were assigned into four groups: 1) Sixteen animals received a daily intraperitoneal injection of caerulein from their ninth week of life on. 2) Sixteen mice were additionally given gemcitabine. 3) Twelve animals received gemcitabine only. 4) Saline-treated control group. Furthermore, human Paca44 pancreatic ductal adenocarcinoma cells were seeded and cultured in 0.5% FBS containing growth medium plus/minus 1 μM gemcitabine plus/minus recombinant human interleukin (IL)-6. RESULTS Induced systemic inflammatory response syndrome and a mild chronic pancreatitis diminished the beneficial effects of gemcitabine upon median overall survival. In median, the monogemcitabine group survived 191 days, whereas the caerulein-mono group survived 114, the control group 121, and the caerulein gemcitabine group 127 days (P < .05). In vitro, the induction of STAT3 phosphorylation by recombinant human IL-6 promoted pancreatic ductal adenocarcinoma cell survival during gemcitabine treatment. CONCLUSION We could demonstrate for the first time that an improvement in median overall survival with gemcitabine is significantly abolished by a persistent mild chronic pancreatitis and a systemic inflammatory response syndrome. In particular, the inflammation biomarkers C-reactive protein, IL-6, and IL-1α could indicate the prognostic benefit of gemcitabine chemotherapy and should now be tested in prospective patient-controlled trials. PMID:24953430

  5. Chronic ingestion of cadmium and lead alters the bioavailability of essential and heavy metals, gene expression pathways and genotoxicity in mouse intestine.

    PubMed

    Breton, Jérôme; Le Clère, Kelly; Daniel, Catherine; Sauty, Mathieu; Nakab, Lauren; Chassat, Thierry; Dewulf, Joëlle; Penet, Sylvie; Carnoy, Christophe; Thomas, Patrick; Pot, Bruno; Nesslany, Fabrice; Foligné, Benoît

    2013-10-01

    Chronic ingestion of environmental heavy metals such as lead (Pb) and cadmium (Cd) causes various well-documented pathologies in specific target organs following their intestinal absorption and subsequent accumulation. However, little is known about the direct impact of the non-absorbed heavy metals on the small intestine and the colon homeostasis. The aim of our study was to compare the specific bioaccumulation and retention of Cd and Pb and their effect on the essential metal balance in primary organs, with those occurring specifically in the gastrointestinal tract of mice. Various doses of Cd (5, 20 and 100 mg l(-1)) and Pb (100 and 500 mg l(-1)) chloride salts were provided in drinking water for subchronic to chronic exposures (4, 8 and 12 weeks). In contrast to a clear dose- and time-dependent accumulation in target organs, results showed that intestines are poor accumulators for Cd and Pb. Notwithstanding, changes in gene expression of representative intestinal markers revealed that the transport-, oxidative- and inflammatory status of the gut epithelium of the duodenum, ileum and colon were specifically affected by both heavy metal species. Additionally, in vivo comet assay used to evaluate the impact of heavy metals on DNA damage showed clear genotoxic activities of Cd, on both the upper and distal parts of the gastrointestinal tract. Altogether, these results outline the resilience of the gut which balances the various effects of chronic Cd and Pb in the intestinal mucosa. Collectively, it provides useful information for the risk assessment of heavy metals in gut homeostasis and further disease's susceptibility. PMID:23503628

  6. Real-Time Bioluminescence Imaging of Nitroreductase in Mouse Model.

    PubMed

    Feng, Ping; Zhang, Huateng; Deng, Quankun; Liu, Wei; Yang, Linghui; Li, Guobo; Chen, Guo; Du, Lupei; Ke, Bowen; Li, Minyong

    2016-06-01

    Nitroreductase (NTR) is an endogenous reductase overexpressed in hypoxic tumors; however, its precise detection in living cells and animals remains a considerable challenge. Herein, we developed three reaction-based probes and a related bioluminescence assay for the real-time NTR detection. The high sensitivity and selectivity of probe 3, combined with its remarkable potential of bioluminescence imaging, affords a valuable approach for in vivo imaging of NTR in a tumor model mouse. PMID:27197544

  7. [Establishment of hepatitis B virus (HBV) chronic infection mouse model by in vivo transduction with a recombinant adeno-associated virus 8 carrying 1. 3 copies of HBV genome (rAAN8-1. 3HBV)].

    PubMed

    Dong, Xiao-Yan; Yu, Chi-Jie; Wang, Gang; Tian, Wen-Hong; Lu, Yue; Zhang, Feng-Wei; Wang, Wen; Wang, Yue; Tan, Wen-Jie; Wu, Xiao-Bing

    2010-11-01

    In this report, we developed a HBV infection model in C57BL/6 mouse line by in vivo injection of a recombinant adeno-associated virus 8 vector carrying 1. 3 copies of HBV genome (ayw subtype) (rAAV8-1. 3HBV). We firstly prepared and purified the rAAV8-1. 3HBV and then injected it into three C57BL/6 mice with the dose of 2 x 10e11vg, respectively. HBsAg and HBeAg were assayed in sera collected at different time points post injection. Ten weeks post injection, the three mice were sacrificed and blood and liver tissue were taken for assay. Copies of HBV DNA were detected by real time PCR and the way of HBV DNA replication was identified by PCR. Subsequently, detection of HBV antigen by immunohistochemistry and pathology analysis of liver tissue of mice were performed. The results suggested that expression of HBsAg and HBeAg lasted for at least 10 weeks in mice sera. Among mice injected with rAAV8-1. 3HBV, HBsAg levels were showed an 'increasing-decreasing-increasing' pattern (the lowest level at the 4th week post injection), while HBeAg levels were kept high and relatively stable. HBV DNA copies were 4.2 x 10(3), 3.6 x 10(3), 2.5 x 10(3) copies/mL in sera and 8.0 x 10(6), 5.7 x 10(6), 2.6 x 10(6) copies/g in hepatic tissues of three mice, respectively. We found that the linear 1. 3HBV DNA in the rAAV8-1. 3HBV could self form into circular HBV genome and replicate in livers of HBV transfected mice. HBsAg and HBcAg were both positive in liver tissue of mice injected with rAAV8-1. 3HBV and no obvious pathological characters were found in liver of mice injected with rAAV8-1. 3HBV. In conclusion, we successfully developed a HBV chronic infection model in C57BL/6 mouse line by in vivo transduction with the recombinant virus rAAV8-1. 3HBV, in which HBV genes could be continuously expressed and replicated over 10 weeks, and paved a way for further characterization of the human chronic hepatitis B virus infection and evaluation of vaccine and anti-HBV agents. PMID:21344744

  8. Accumulation of Regulatory T Cells and Chronic Inflammation in the Middle Ear in a Mouse Model of Chronic Otitis Media with Effusion Induced by Combined Eustachian Tube Blockage and Nontypeable Haemophilus influenzae Infection.

    PubMed

    Hirano, Takashi; Kodama, Satoru; Kawano, Toshiaki; Suzuki, Masashi

    2016-01-01

    Nontypeable Haemophilus influenzae (NTHi) is associated with chronic otitis media (COM). In this study, we generated a murine model of COM by using eustachian tube (ET) obstruction and NTHi (10(7) CFU) inoculation into the tympanic bulla, and we investigated the relationship between regulatory T cells (Treg) and chronic inflammation in the middle ear. Middle ear effusions (MEEs) and middle ear mucosae (MEM) were collected at days 3 and 14 and at 1 and 2 months after inoculation. Untreated mice served as controls. MEEs were used for bacterial counts and to measure the concentrations of cytokines. MEM were collected for histological evaluation and flow cytometric analysis. Inflammation of the MEM was prolonged throughout this study, and the incidence of NTHi culture-positive MEE was 38% at 2 months after inoculation. The levels of interleukin-1β (IL-β), tumor necrosis factor alpha, IL-10, and transforming growth factor β were increased in the middle ear for up to 2 months after inoculation. CD4(+) CD25(+) FoxP3(+) Treg accumulated in the middle ear, and the percentage of Treg in the MEM increased for up to 2 months after inoculation. Treg depletion induced a 99.9% reduction of bacterial counts in MEEs and also significantly reduced the ratio of NTHi culture-positive MEE. The levels of these cytokines were also reduced in MEEs. In summary, we developed a murine model of COM, and our findings indicate that Treg confer infectious tolerance to NTHi in the middle ear. PMID:26553466

  9. Accumulation of Regulatory T Cells and Chronic Inflammation in the Middle Ear in a Mouse Model of Chronic Otitis Media with Effusion Induced by Combined Eustachian Tube Blockage and Nontypeable Haemophilus influenzae Infection

    PubMed Central

    Kodama, Satoru; Kawano, Toshiaki

    2015-01-01

    Nontypeable Haemophilus influenzae (NTHi) is associated with chronic otitis media (COM). In this study, we generated a murine model of COM by using eustachian tube (ET) obstruction and NTHi (107 CFU) inoculation into the tympanic bulla, and we investigated the relationship between regulatory T cells (Treg) and chronic inflammation in the middle ear. Middle ear effusions (MEEs) and middle ear mucosae (MEM) were collected at days 3 and 14 and at 1 and 2 months after inoculation. Untreated mice served as controls. MEEs were used for bacterial counts and to measure the concentrations of cytokines. MEM were collected for histological evaluation and flow cytometric analysis. Inflammation of the MEM was prolonged throughout this study, and the incidence of NTHi culture-positive MEE was 38% at 2 months after inoculation. The levels of interleukin-1β (IL-β), tumor necrosis factor alpha, IL-10, and transforming growth factor β were increased in the middle ear for up to 2 months after inoculation. CD4+ CD25+ FoxP3+ Treg accumulated in the middle ear, and the percentage of Treg in the MEM increased for up to 2 months after inoculation. Treg depletion induced a 99.9% reduction of bacterial counts in MEEs and also significantly reduced the ratio of NTHi culture-positive MEE. The levels of these cytokines were also reduced in MEEs. In summary, we developed a murine model of COM, and our findings indicate that Treg confer infectious tolerance to NTHi in the middle ear. PMID:26553466

  10. Acute and chronic stress differentially regulate cyclin-dependent kinase 5 in mouse brain: implications to glucocorticoid actions and major depression

    PubMed Central

    Papadopoulou, A; Siamatras, T; Delgado-Morales, R; Amin, N D; Shukla, V; Zheng, Y-L; Pant, H C; Almeida, O F X; Kino, T

    2015-01-01

    Stress activates the hypothalamic–pituitary–adrenal axis, which in turn increases circulating glucocorticoid concentrations and stimulates the glucocorticoid receptor (GR). Chronically elevated glucocorticoids by repetitive exposure to stress are implicated in major depression and anxiety disorders. Cyclin-dependent kinase 5 (CDK5), a molecule essential for nervous system development, function and pathogenesis of neurodegenerative disorders, can modulate GR activity through phosphorylation. We examined potential contribution of CDK5 to stress response and pathophysiology of major depression. In mice, acute immobilized stress (AS) caused a biphasic effect on CDK5 activity, initially reducing but increasing afterwards in prefrontal cortex (PFC) and hippocampus (HIPPO), whereas chronic unpredictable stress (CS) strongly increased it in these brain areas, indicating that AS and CS differentially regulate this kinase activity in a brain region-specific fashion. GR phosphorylation contemporaneously followed the observed changes of CDK5 activity after AS, thus CDK5 may in part alter GR phosphorylation upon this stress. In the postmortem brains of subjects with major depression, CDK5 activity was elevated in Brodmann's area 25, but not in entire PFC and HIPPO. Messenger RNA expression of glucocorticoid-regulated/stress-related genes showed distinct expression profiles in several brain areas of these stressed mice or depressive subjects in which CDK5-mediated changes in GR phosphorylation may have some regulatory roles. Taken together, these results indicate that CDK5 is an integral component of stress response and major depression with regulatory means specific to different stressors, brain areas and diseases in part through changing phosphorylation of GR. PMID:26057048

  11. Neurobehavioral impairments, generation of oxidative stress and release of pro-apoptotic factors after chronic exposure to sulphur mustard in mouse brain

    SciTech Connect

    Sharma, Deep Raj; Sunkaria, Aditya; Bal, Amanjit; Bhutia, Yangchen D.; Vijayaraghavan, R.; Flora, S.J.S.; Gill, Kiran Dip

    2009-10-15

    Recent global events have focused attention on the potential threat of international and domestic chemical terrorism, as well as the possibility of chemical warfare proliferation. Sulphur mustard (SM) is one of the potent chemical warfare agents (CWA), which initiates a cascade of events that converge on the redox mechanisms common to brain injury. The present study was designed to examine the effects of chronic SM exposure on neurobehavioral impairments, mitochondrial oxidative stress in male Swiss Albino mice and its role in inducing apoptotic neuronal cell death. The animals were divided into four groups (control, low, medium and high dose) of 5 animals each. Exposure to SM was given percutaneously daily for 12 weeks. The results demonstrated impairment in neurobehavioral indices viz. rota rod, passive avoidance and water maze tests in a dose dependent manner. There was a significant increase in lipid peroxidation and protein carbonyl content whereas, decrease in the activity of manganese superoxide dismutase (MnSOD), glutathione reductase and glutathione peroxidase suggesting impaired antioxidant defense system. Immunoblotting of cytochrome c, Bcl-2, Bax and activation of caspase-3 suggest induction of apoptosis in a dose dependent manner. Finally, increased p53 expression suggests that it may target the mitochondrial pathway for inducing apoptosis in response to DNA damage signals. In conclusion, chronic SM exposure may have the potential to generate oxidative stress which may trigger the release of cytochrome c as well as caspase-3 activation in neurons leading to cell death by apoptosis in a dose dependent manner which may in the end be responsible for the disruption of cognitive functions in mice.

  12. Chronic consumption of a western diet induces robust glial activation in aging mice and in a mouse model of Alzheimer’s disease

    PubMed Central

    Graham, Leah C.; Harder, Jeffrey M.; Soto, Ileana; de Vries, Wilhelmine N.; John, Simon W. M.; Howell, Gareth R.

    2016-01-01

    Studies have assessed individual components of a western diet, but no study has assessed the long-term, cumulative effects of a western diet on aging and Alzheimer’s disease (AD). Therefore, we have formulated the first western-style diet that mimics the fat, carbohydrate, protein, vitamin and mineral levels of western diets. This diet was fed to aging C57BL/6J (B6) mice to identify phenotypes that may increase susceptibility to AD, and to APP/PS1 mice, a mouse model of AD, to determine the effects of the diet in AD. Astrocytosis and microglia/monocyte activation were dramatically increased in response to diet and was further increased in APP/PS1 mice fed the western diet. This increase in glial responses was associated with increased plaque burden in the hippocampus. Interestingly, given recent studies highlighting the importance of TREM2 in microglia/monocytes in AD susceptibility and progression, B6 and APP/PS1 mice fed the western diet showed significant increases TREM2+ microglia/monocytes. Therefore, an increase in TREM2+ microglia/monocytes may underlie the increased risk from a western diet to age-related neurodegenerative diseases such as Alzheimer’s disease. This study lays the foundation to fully investigate the impact of a western diet on glial responses in aging and Alzheimer’s disease. PMID:26888450

  13. Chronic exposure to arsenic in drinking water can lead to resistance to antimonial drugs in a mouse model of visceral leishmaniasis.

    PubMed

    Perry, Meghan R; Wyllie, Susan; Raab, Andrea; Feldmann, Joerg; Fairlamb, Alan H

    2013-12-01

    The Indian subcontinent is the only region where arsenic contamination of drinking water coexists with widespread resistance to antimonial drugs that are used to treat the parasitic disease visceral leishmaniasis. We have previously proposed that selection for parasite resistance within visceral leishmaniasis patients who have been exposed to trivalent arsenic results in cross-resistance to the related metalloid antimony, present in the pentavalent state as a complex in drugs such as sodium stibogluconate (Pentostam) and meglumine antimonate (Glucantime). To test this hypothesis, Leishmania donovani was serially passaged in mice exposed to arsenic in drinking water at environmentally relevant levels (10 or 100 ppm). Arsenic accumulation in organs and other tissues was proportional to the level of exposure and similar to that previously reported in human liver biopsies. After five monthly passages in mice exposed to arsenic, isolated parasites were found to be completely refractory to 500 μg · mL(-1) Pentostam compared with the control passage group (38.5 μg · mL(-1)) cultured in vitro in mouse peritoneal macrophages. Reassessment of resistant parasites following further passage for 4 mo in mice without arsenic exposure showed that resistance was stable. Treatment of infected mice with Pentostam confirmed that resistance observed in vitro also occurred in vivo. We conclude that arsenic contamination may have played a significant role in the development of Leishmania antimonial resistance in Bihar because inadequate treatment with antimonial drugs is not exclusive to India, whereas widespread antimonial resistance is. PMID:24167266

  14. Chronic consumption of a western diet induces robust glial activation in aging mice and in a mouse model of Alzheimer's disease.

    PubMed

    Graham, Leah C; Harder, Jeffrey M; Soto, Ileana; de Vries, Wilhelmine N; John, Simon W M; Howell, Gareth R

    2016-01-01

    Studies have assessed individual components of a western diet, but no study has assessed the long-term, cumulative effects of a western diet on aging and Alzheimer's disease (AD). Therefore, we have formulated the first western-style diet that mimics the fat, carbohydrate, protein, vitamin and mineral levels of western diets. This diet was fed to aging C57BL/6J (B6) mice to identify phenotypes that may increase susceptibility to AD, and to APP/PS1 mice, a mouse model of AD, to determine the effects of the diet in AD. Astrocytosis and microglia/monocyte activation were dramatically increased in response to diet and was further increased in APP/PS1 mice fed the western diet. This increase in glial responses was associated with increased plaque burden in the hippocampus. Interestingly, given recent studies highlighting the importance of TREM2 in microglia/monocytes in AD susceptibility and progression, B6 and APP/PS1 mice fed the western diet showed significant increases TREM2+ microglia/monocytes. Therefore, an increase in TREM2+ microglia/monocytes may underlie the increased risk from a western diet to age-related neurodegenerative diseases such as Alzheimer's disease. This study lays the foundation to fully investigate the impact of a western diet on glial responses in aging and Alzheimer's disease. PMID:26888450

  15. Intranasal administration of aTf protects and repairs the neonatal white matter after a cerebral hypoxic-ischemic event.

    PubMed

    Guardia Clausi, Mariano; Paez, Pablo M; Campagnoni, Anthony T; Pasquini, Laura A; Pasquini, Juana M

    2012-10-01

    Our previous studies showed that the intracerebral injection of apotransferrin (aTf) attenuates white matter damage and accelerates the remyelination process in a neonatal rat model of cerebral hypoxia-ischemia (HI) injury. However, the intracerebral injection of aTf might not be practical for clinical treatments. Therefore, the development of less invasive techniques capable of delivering aTf to the central nervous system would clearly aid in its effective clinical use. In this work, we have determined whether intranasal (iN) administration of human aTf provides neuroprotection to the neonatal mouse brain following a cerebral hypoxic-ischemic event. Apotransferrin was infused into the naris of neonatal mice and the HI insult was induced by right common carotid artery ligation followed by exposure to low oxygen concentration. Our results showed that aTf was successfully delivered into the neonatal HI brain and detected in the olfactory bulb, forebrain and posterior brain 30 min after inhalation. This treatment successfully reduced white matter damage, neuronal loss and astrogliosis in different brain regions and enhanced the proliferation and survival of oligodendroglial progenitor cells (OPCs) in the subventricular zone and corpus callosum (CC). Additionally, using an in vitro hypoxic model, we demonstrated that aTf prevents oligodendrocyte progenitor cell death by promoting their differentiation. In summary, these data suggest that iN administration of aTf has the potential to be used for clinical treatment to protect myelin and to induce remyelination in demyelinating hypoxic-ischemic events in the neonatal brain. PMID:22736466

  16. The neuronal control of hypoxic ventilation: erythropoietin and sexual dimorphism.

    PubMed

    Gassmann, Max; Tissot van Patot, Martha; Soliz, Jorge

    2009-10-01

    Using mice, we demonstrated that when oxygen supply is lowered, erythropoietin (Epo), the main regulator of red blood cell production, modulates the ventilatory response by interacting with central (brainstem) and peripheral (carotid bodies) respiratory centers. We showed that enhanced Epo levels in the brainstem increased the hypoxic ventilatory response, and that intracerebroventricular injection of an Epo antagonist (soluble Epo receptor) abolished the ventilatory acclimatization to hypoxia. More recently, we have found that the impact of Epo on ventilation occurs in a sex-dependent manner. Keeping in mind that women are less susceptible to several respiratory sicknesses and syndromes than men, we suggest that Epo plays a key role in sexually-dimorphic hypoxic ventilation. Accordingly, we foresee that Epo has a potential therapeutic use as treatment for hypoxia-associated ventilatory diseases. PMID:19845617

  17. Hypoxic adaptation during development: relation to pattern of neurological presentation and cognitive disability.

    PubMed

    Kirkham, Fenella J; Datta, Avijit K

    2006-07-01

    Children with acute hypoxic-ischaemic events (e.g. stroke) and chronic neurological conditions associated with hypoxia frequently present to paediatric neurologists. Failure to adapt to hypoxia may be a common pathophysiological pathway linking a number of other conditions of childhood with cognitive deficit. There is evidence that congenital cardiac disease, asthma and sleep disordered breathing, for example, are associated with cognitive deficit, but little is known about the mechanism and whether there is any structural change. This review describes what is known about how the brain reacts and adapts to hypoxia, focusing on epilepsy and sickle cell disease (SCD). We prospectively recorded overnight oxyhaemoglobin saturation (SpO2) in 18 children with intractable epilepsy, six of whom were currently or recently in minor status (MS). Children with MS were more likely to have an abnormal sleep study defined as either mean baseline SpO2 <94% or >4 dips of >4% in SpO2/hour (p = .04). In our series of prospectively followed patients with SCD who subsequently developed acute neurological symptoms and signs, mean overnight SpO2 was lower in those with cerebrovascular disease on magnetic resonance angiography (Mann-Whitney, p = .01). Acute, intermittent and chronic hypoxia may have detrimental effects on the brain, the clinical manifestations perhaps depending on rapidity of presentation and prior exposure. PMID:16764614

  18. Chronic unilateral ureteral obstruction in the neonatal mouse delays maturation of both kidneys and leads to late formation of atubular glomeruli

    PubMed Central

    Forbes, Michael S.; Thornhill, Barbara A.; Galarreta, Carolina I.; Minor, Jordan J.; Gordon, Katherine A.

    2013-01-01

    Unilateral ureteral obstruction (UUO) in the adult mouse is the most widely used model of progressive renal disease: the proximal tubule is the nephron segment most severely affected and atubular glomeruli are formed after only 7 days of UUO. To determine the proximal nephron response to UUO in the maturing kidney, neonatal mice were examined 7 to 28 days following complete UUO under general anesthesia. Proximal tubular mass and maturation were determined by staining with Lotus tetragolonobus lectin. Superoxide was localized by nitroblue tetrazolium and collagen by Sirius red. Cell proliferation, cell death, PAX-2, megalin, α-smooth muscle actin (α-SMA), renin, and fibronectin were identified by immunohistochemistry. During the first 14 days of ipsilateral UUO, despite oxidative stress (4-hydroxynonenal staining), glomerulotubular continuity was maintained and mitochondrial superoxide production persisted. However, from 14 to 28 days, papillary growth was impaired and proximal tubules collapsed with increased apoptosis, autophagy, mitochondrial loss, and formation of atubular glomeruli. Fibronectin, α-SMA, and collagen increased in the obstructed kidney. Oxidative stress was present also in the contralateral kidney: renin was decreased, glomerulotubular maturation and papillary growth were delayed, followed by increased cortical and medullary growth. We conclude that neonatal UUO initially delays renal maturation and results in oxidative stress in both kidneys. In contrast to the adult, proximal tubular injury in the neonatal obstructed kidney is delayed at 14 days, followed only later by the formation of atubular glomeruli. Antioxidant therapies directed at proximal tubular mitochondria during early renal maturation may slow progression of congenital obstructive nephropathy. PMID:24107422

  19. Metabolism of Doxorubicin to the Cardiotoxic Metabolite Doxorubicinol Is Increased in a Mouse Model of Chronic Glutathione Deficiency: A Potential Role for Carbonyl Reductase 3

    PubMed Central

    Schaupp, Christopher M.; White, Collin C.; Merrill, Gary F.; Kavanagh, Terrance J.

    2014-01-01

    Doxorubicin is highly effective at inducing DNA double-strand breaks in rapidly dividing cells, which has led to it being a widely used cancer chemotherapeutic. However, clinical administration of doxorubicin is limited by off-target cardiotoxicity, which is thought to be mediated by doxorubicinol, the primary alcohol metabolite of doxorubicin. Carbonyl reductase 1 (CBR1), a well-characterized monomeric enzyme present at high basal levels in the liver, is known to exhibit activity toward doxorubicin. Little is known about a closely related enzyme, carbonyl reductase 3 (CBR3), which is present in the liver at low basal levels but is highly inducible by the transcription factor Nrf2. Genetic polymorphisms in CBR3, but not CBR1, are associated with differential cardiac outcomes in doxorubicin treated pediatric patients. Cbr3 mRNA and CBR3 protein are highly expressed in the livers of Gclm −/− mice (a mouse model of glutathione deficiency) relative to wild type mice. In the present study, we first investigated the ability of CBR3 to metabolize doxorubicin. Incubations of doxorubicin and purified recombinant murine CBR3 (mCBR3) were analyzed for doxorubicinol formation using HPLC, revealing for the first time that doxorubicin is a substrate of mCBR3. Moreover, hepatocytes from Gclm −/− mice produced more doxorubicinol than Gclm +/+ hepatocytes. In addition, differentiated rat myoblasts (C2C12 cells) co-cultured with primary Gclm −/− murine hepatocytes were more sensitive to doxorubicin-induced cytostasis/cytotoxicity than incubations with Gclm +/+ hepatocytes. Our results indicate a potentially important role for CBR3 in doxorubicin-induced cardiotoxicity. Because there is likely to be variability in hepatic CBR3 activity in humans (due to either genetic or epigenetic influences on its expression), these data also suggest that inhibition of CBR3 may provide protection from doxorubicinol cardiotoxicity. PMID:25446851

  20. Accumulation of peribronchial mast cells in a mouse model of ovalbumin allergen induced chronic airway inflammation: modulation by immunostimulatory DNA sequences.

    PubMed

    Ikeda, Reid K; Miller, Marina; Nayar, Jyothi; Walker, Linda; Cho, Jae Youn; McElwain, Kirsti; McElwain, Shauna; Raz, Eyal; Broide, David H

    2003-11-01

    Few peribronchial mast cells are noted either in the lungs of naive mice or in the lungs of OVA-sensitized mice challenged acutely with OVA by inhalation. In this study, we demonstrate that OVA-sensitized mice exposed to repetitive OVA inhalation for 1-6 mo have a significant accumulation of peribronchial mast cells. This accumulation of peribronchial mast cells is associated with increased expression of the Th2 cell-derived mast cell growth factors, including IL-4 and IL-9, but not with the non-Th2 cell-derived mast cell growth factor, stem cell factor. Pretreating mice with immunostimulatory sequences (ISS) of DNA containing a CpG motif significantly inhibited the accumulation of peribronchial mast cells and the expression of IL-4 and IL-9. To determine whether mast cells express Toll-like receptor-9 (TLR-9; the receptor for ISS), TLR-9 expression by mouse bone marrow-derived mast cells (MBMMCs) was assessed by RT-PCR. MBMMCs strongly expressed TLR-9 and bound rhodamine-labeled ISS. However, incubation of MBMMCs with ISS in vitro neither inhibited MBMMC proliferation nor inhibited Ag/IgE-mediated MBMMC degranulation, but they did induce IL-6. Overall these studies demonstrate that mice exposed to repetitive OVA challenge, but not acute OVA challenge, have an accumulation of peribronchial mast cells and express increased levels of mast cell growth factors in the lung. Although mast cells express TLR-9, ISS does not directly inhibit mast cell proliferation in vitro, suggesting that ISS inhibits accumulation of peribronchial mast cells in vivo by indirect mechanism(s), which include inhibiting the lung expression of Th2 cell-derived mast cell growth factors. PMID:14568966

  1. The Galvanotactic Migration of Keratinocytes is Enhanced by Hypoxic Preconditioning

    PubMed Central

    Guo, Xiaowei; Jiang, Xupin; Ren, Xi; Sun, Huanbo; Zhang, Dongxia; Zhang, Qiong; Zhang, Jiaping; Huang, Yuesheng

    2015-01-01

    The endogenous electric field (EF)-directed migration of keratinocytes (galvanotaxis) into wounds is an essential step in wound re-epithelialization. Hypoxia, which occurs immediately after injury, acts as an early stimulus to initiate the healing process; however, the mechanisms for this effect, remain elusive. We show here that the galvanotactic migration of keratinocytes was enhanced by hypoxia preconditioning as a result of the increased directionality rather than the increased motility of keratinocytes. This enhancement was both oxygen tension- and preconditioning time-dependent, with the maximum effects achieved using 2% O2 preconditioning for 6 hours. Hypoxic preconditioning (2% O2, 6 hours) decreased the threshold voltage of galvanotaxis to < 25 mV/mm, whereas this value was between 25 and 50 mV/mm in the normal culture control. In a scratch-wound monolayer assay in which the applied EF was in the default healing direction, hypoxic preconditioning accelerated healing by 1.38-fold compared with the control conditions. Scavenging of the induced ROS by N-acetylcysteine (NAC) abolished the enhanced galvanotaxis and the accelerated healing by hypoxic preconditioning. Our data demonstrate a novel and unsuspected role of hypoxia in supporting keratinocyte galvanotaxis. Enhancing the galvanotactic response of cells might therefore be a clinically attractive approach to induce improved wound healing. PMID:25988491

  2. Low-dose radiation suppresses Pokemon expression under hypoxic conditions.

    PubMed

    Kim, Seung-Whan; Yu, Kweon; Shin, Kee-Sun; Kwon, Kisang; Hwang, Tae-Sik; Kwon, O-Yu

    2014-01-01

    Our previous data demonstrated that CoCl2-induced hypoxia controls endoplasmic reticulum (ER) stress-associated and other intracellular factors. One of them, the transcription factor Pokemon, was differentially regulated by low-dose radiation (LDR). There are limited data regarding how this transcription factor is involved in expression of the unfolded protein response (UPR) under hypoxic conditions. The purpose of this study was to obtain clues on how Pokemon is involved in the UPR. Pokemon was selected as a differentially expressed gene under hypoxic conditions; however, its regulation was clearly repressed by LDR. It was also demonstrated that both expression of ER chaperones and ER stress sensors were affected by hypoxic conditions, and the same results were obtained when cells in which Pokemon was up- or down-regulated were used. The current state of UPR and LDR research associated with the Pokemon pathway offers an important opportunity to understand the oncogenesis, senescence, and differentiation of cells, as well as to facilitate introduction of new therapeutic radiopharmaceuticals. PMID:24772825

  3. Hypoxic-Ischemic Neonatal Encephalopathy: Animal Experiments for Neuroprotective Therapies

    PubMed Central

    Ikenoue, Tsuyomu

    2013-01-01

    Hypoxic-ischemic neonatal encephalopathy and ensuing brain damage is still an important problem in modern perinatal medicine. In this paper, we would like to share some of the results of our recent studies on neuroprotective therapies in animal experiments, as well as some literature reviews. From the basic animal studies, we have now obtained some possible candidates for therapeutic measures against hypoxic-ischemic neonatal encephalopathy. For example, they are hypothermia, rehabilitation, free radical scavenger, neurotrophic factors and growth factors, steroid, calcium channel blocker, vagal stimulation, some anti apoptotic agents, pre- and post conditioning, antioxidants, cell therapy with stem cells, modulators of K(+)-ATP channels, and so on. Whether combination of these therapies may be more beneficial than any single therapy needs to be clarified. Hypoxia-ischemia is a complicated condition, in which the cause, severity, and time-course are different in each case. Likewise, each fetus has its own inherent potentials such as adaptation, preconditioning-tolerance, and intolerance. Therefore, further extensive studies are required to establish an individualized strategy for neuroprotection against perinatal hypoxic-ischemic insult. PMID:23533962

  4. Epigenetic regulation of hypoxic sensing disrupts cardiorespiratory homeostasis

    PubMed Central

    Nanduri, Jayasri; Makarenko, Vladislav; Reddy, Vaddi Damodara; Yuan, Guoxiang; Pawar, Anita; Wang, Ning; Khan, Shakil A.; Zhang, Xin; Kinsman, Brian; Peng, Ying-Jie; Kumar, Ganesh K.; Fox, Aaron P.; Godley, Lucy A.; Semenza, Gregg L.; Prabhakar, Nanduri R.

    2012-01-01

    Recurrent apnea with intermittent hypoxia is a major clinical problem in preterm infants. Recent studies, although limited, showed that adults who were born preterm exhibit increased incidence of sleep-disordered breathing and hypertension, suggesting that apnea of prematurity predisposes to autonomic dysfunction in adulthood. Here, we demonstrate that adult rats that were exposed to intermittent hypoxia as neonates exhibit exaggerated responses to hypoxia by the carotid body and adrenal chromaffin cells, which regulate cardio-respiratory function, resulting in irregular breathing with apneas and hypertension. The enhanced hypoxic sensitivity was associated with elevated oxidative stress, decreased expression of genes encoding antioxidant enzymes, and increased expression of pro-oxidant enzymes. Decreased expression of the Sod2 gene, which encodes the antioxidant enzyme superoxide dismutase 2, was associated with DNA hypermethylation of a single CpG dinucleotide close to the transcription start site. Treating neonatal rats with decitabine, an inhibitor of DNA methylation, during intermittent hypoxia exposure prevented oxidative stress, enhanced hypoxic sensitivity, and autonomic dysfunction. These findings implicate a hitherto uncharacterized role for DNA methylation in mediating neonatal programming of hypoxic sensitivity and the ensuing autonomic dysfunction in adulthood. PMID:22232674

  5. The Syndrome of Delayed Post-Hypoxic Leukoencephalopathy

    PubMed Central

    Shprecher, David; Mehta, Lahar

    2010-01-01

    Delayed post-hypoxic leukoencephalopathy (DPHL) is a demyelinating syndrome characterized by acute onset of neuropsychiatric symptoms days to weeks following apparent recovery from coma after a period of prolonged cerebral hypo-oxygenation. It is diagnosed, after excluding other potential causes of delirium, with a clinical history of carbon monoxide poisoning, narcotic overdose, myocardial infarction, or another global cerebral hypoxic event. The diagnosis can be supported by neuroimaging evidence of diffuse hemispheric demyelination sparing cerebellar and brainstem tracts, or by an elevated cerebrospinal fluid myelin basic protein. Standard or hyperbaric oxygen following CO poisoning may reduce the likelihood of DPHL or other neurologic sequelae. Bed rest and avoidance of stressful procedures for the first 10 days following any prolonged hypoxic event may also lower the risk. Gradual recovery over a 3 to 12 month period is common, but impaired attention or executive function, parkinsonism, or corticospinal tract signs can persist. Stimulants, amantadine or levodopa may be considered for lasting cognitive or parkinsonian symptoms. Anticipation and recognition of DPHL should lead to earlier and more appropriate utilization of health care services. PMID:20166270

  6. Cerebral blood flow autoregulation during intracranial hypertension in hypoxic lambs

    SciTech Connect

    Borel, C.O.; Backofen, J.E.; Koehler, R.C.; Jones, M.D. Jr.; Traystman, R.J. )

    1987-12-01

    The authors tested the hypothesis that hypoxic hypoxia interferes with cerebral blood flow (CBF) autoregulation when intracranial pressure (ICP) is elevated in pentobarbital-anesthetized lambs (3 to 9 days old). Cerebral perfusion pressure (CPP) was lowered stepwise from 73 to 23 mmHg in eight normoxic lambs and from 65 to 31 mmHg in eight other hypoxic lambs by ventricular infusion of artificial cerebrospinal fluid. In normoxic lambs, CBF measured by microspheres labeled with six different radioisotopes was not significantly changed over this range of CPP. In animals made hypoxic, base-line CBF was twice that of normoxic lambs. CBF was unchanged as CPP was reduced to 31 mmHg. Lower levels of CPP were not attained because a pressor response occurred with further elevations of ICP. No regional decrements in blood flow to cortical arterial watershed areas or to more caudal regions, such as cerebellum, brain stem, or thalamus, were detected with elevated ICP. Cerebral O{sub 2} uptake was similar in both groups and did not decrease when CPP was reduced. These results demonstrate that normoxic lambs have a considerable capacity for effective autoregulation of CBF when ICP is elevated. Moreover, cerebral vasodilation in response to a level of hypoxia approximating that normally seen prenatally does not abolish CBF autoregulation when ICP is elevated during the first postnatal week.

  7. Insulin-like Growth Factor I (IGF-I)-induced Chronic Gliosis and Retinal Stress Lead to Neurodegeneration in a Mouse Model of Retinopathy*

    PubMed Central

    Villacampa, Pilar; Ribera, Albert; Motas, Sandra; Ramírez, Laura; García, Miquel; de la Villa, Pedro; Haurigot, Virginia; Bosch, Fatima

    2013-01-01

    Insulin-like growth factor I (IGF-I) exerts multiple effects on different retinal cell types in both physiological and pathological conditions. Despite the growth factor's extensively described neuroprotective actions, transgenic mice with increased intraocular levels of IGF-I showed progressive impairment of electroretinographic amplitudes up to complete loss of response, with loss of photoreceptors and bipolar, ganglion, and amacrine neurons. Neurodegeneration was preceded by the overexpression of genes related to retinal stress, acute-phase response, and gliosis, suggesting that IGF-I altered normal retinal homeostasis. Indeed, gliosis and microgliosis were present from an early age in transgenic mice, before other alterations occurred, and were accompanied by signs of oxidative stress and impaired glutamate recycling. Older mice also showed overproduction of pro-inflammatory cytokines. Our results suggest that, when chronically increased, intraocular IGF-I is responsible for the induction of deleterious cellular processes that can lead to neurodegeneration, and they highlight the importance that this growth factor may have in the pathogenesis of conditions such as ischemic or diabetic retinopathy. PMID:23620587

  8. Hypothalamic Proteomic Analysis Reveals Dysregulation of Glutamate Balance and Energy Metabolism in a Mouse Model of Chronic Mild Stress-Induced Depression.

    PubMed

    Rao, Chenglong; Shi, Haiyang; Zhou, Chanjuan; Zhu, Dan; Zhao, Mingjun; Wang, Ziye; Yang, Yongtao; Chen, Jin; Liao, Li; Tang, Jianyong; Wu, You; Zhou, Jian; Cheng, Ke; Xie, Peng

    2016-09-01

    Hypothalamus-pituitary-adrenal (HPA) axis hyperactivity is observed in many patients suffering from depression. However, the mechanism underlying the dysfunction of the HPA axis is not well understood. Moreover, dysfunction of the hypothalamus, the key brain region of the HPA axis, has not been well-explored. The aim of our study was to examine possible alterations in hypothalamus protein expression in a model of depression using proteomic analysis. In order to achieve this aim, mice were exposed to chronic unpredictable mild stress (CUMS), as the paradigm results in hyperactivity of the HPA axis. Differential protein expression between the hypothalamic proteomes of CUMS and control mice was then assessed through two-dimensional electrophoresis followed by matrix-assisted laser desorption ionization-time of flight-tandem mass spectrometry. Thirty-seven proteins with a threshold of a 1.5-fold change and a p value ≤0.05 were identified as being differentially expressed between CUMS and control mice, and were quantified for bioinformatics analysis. Glycometabolism, citrate cycle (TCA cycle) and oxidation respiratory chain were found to have changed significantly. Glial fibrillary acidic protein and glutamine synthetase were further validated by Western Blot. Our results demonstrated that CUMS mice exhibited a dramatic protein change both in glutamate metabolism and energy mobilization, which may shed some light on the role of the hypothalamus in the pathology of stress-induced depression. PMID:27230881

  9. Micro-heterogeneity of flow in a mouse model of chronic cerebral hypoperfusion revealed by longitudinal Doppler optical coherence tomography and angiography.

    PubMed

    Srinivasan, Vivek J; Yu, Esther; Radhakrishnan, Harsha; Can, Anil; Climov, Mihail; Leahy, Conor; Ayata, Cenk; Eikermann-Haerter, Katharina

    2015-10-01

    Although microvascular dysfunction accompanies cognitive decline in aging, vascular dementia, and Alzheimer's disease, tools to study microvasculature longitudinally in vivo are lacking. Here, we use Doppler optical coherence tomography (OCT) and angiography for noninvasive, longitudinal imaging of mice with chronic cerebral hypoperfusion for up to 1 month. In particular, we optimized the OCT angiography method to selectively image red blood cell (RBC)-perfused capillaries, leading to a novel way of assessing capillary supply heterogeneity in vivo. After bilateral common carotid artery stenosis (BCAS), cortical blood flow measured by Doppler OCT dropped to half of baseline throughout the imaged tissue acutely. Microscopic imaging of the capillary bed with OCT angiography further revealed local heterogeneities in cortical flow supply during hypoperfusion. The number of RBC-perfused capillaries decreased, leading to increased oxygen diffusion distances in the days immediately after BCAS. Linear regression showed that RBC-perfused capillary density declined by 0.3% for a drop in flow of 1 mL/100 g per minute, and decreases in RBC-perfused capillary density as high as 25% were observed. Taken together, these results demonstrate the existence of local supply heterogeneity at the capillary level even at nonischemic global flow levels, and demonstrate a novel imaging method to assess this heterogeneity. PMID:26243708

  10. NKG2D mediates NK cell hyperresponsiveness and influenza-induced pathologies in a mouse model of chronic obstructive pulmonary disease.

    PubMed

    Wortham, Brian W; Eppert, Bryan L; Motz, Greg T; Flury, Jennifer L; Orozco-Levi, Mauricio; Hoebe, Kasper; Panos, Ralph J; Maxfield, Melissa; Glasser, Stephan W; Senft, Albert P; Raulet, David H; Borchers, Michael T

    2012-05-01

    Chronic obstructive pulmonary disease (COPD) is characterized by peribronchial and perivascular inflammation and largely irreversible airflow obstruction. Acute disease exacerbations, due frequently to viral infections, lead to enhanced disease symptoms and contribute to long-term progression of COPD pathology. Previously, we demonstrated that NK cells from cigarette smoke (CS)-exposed mice exhibit enhanced effector functions in response to stimulating cytokines or TLR ligands. In this article, we show that the activating receptor NKG2D is a key mediator for CS-stimulated NK cell hyperresponsiveness, because CS-exposed NKG2D-deficient mice (Klrk1(-/-)) did not exhibit enhanced effector functions as assessed by cytokine responsiveness. NK cell cytotoxicity against MHC class I-deficient targets was not affected in a COPD model. However, NK cells from CS-exposed mice exhibit greater cytotoxic activity toward cells that express the NKG2D ligand RAET1ε. We also demonstrate that NKG2D-deficient mice exhibit diminished airway damage and reduced inflammation in a model of viral COPD exacerbation, which do not affect viral clearance. Furthermore, adoptive transfer of NKG2D(+) NK cells into CS-exposed, influenza-infected NKG2D-deficient mice recapitulated the phenotypes observed in CS-exposed, influenza-infected wild-type mice. Our findings indicate that NKG2D stimulation during long-term CS exposure is a central pathway in the development of NK cell hyperresponsiveness and influenza-mediated exacerbations of COPD. PMID:22467655

  11. Combination of the Pro-Apoptotic TRAIL-Receptor Antibody Mapatumumab With Ionizing Radiation Strongly Increases Long-Term Tumor Control Under Ambient and Hypoxic Conditions

    SciTech Connect

    Marini, Patrizia; Budach, Wilfried; Niyazi, Maximilian; Junginger, Dorothea; Stickl, Stefan; Jendrossek, Verena; Belka, Claus

    2009-09-01

    Purpose: Mapatumumab, an agonistic tumor necrosis factor-related apoptosis inducing ligand-receptor antibody, exerts highly synergistic apoptotic effects in vitro and in short-term growth delay assays when combined with irradiation. Because it remained unclear in how far these effects influence local tumor control, long-term experiments using a colorectal xenograft model were undertaken. Material and Methods: Experiments were performed with irradiation (5 x 3 Gy, d1-5) and mapatumumab (10 mg/kg) in Colo205-xenograft-bearing NMRI (nu/nu) nude mice. Graded top up doses were delivered on the tumor-bearing hind leg under ambient and hypoxic conditions; follow-up was 270 days. Growth delay and local tumor control were end points of the study. Statistical analysis of the experiments included calculation of tumor regrowth and local tumor control. Results: After combined treatment, a pronounced tumor regrowth-delay was observed when compared with irradiation alone. Long-term experiments revealed a highly significant increase in local tumor control for ambient (p = 0.00076) and hypoxic treatment (p = 0.000069). Conclusions: The present data demonstrate for the first time that combination of a pro-apoptotic antibody with irradiation results in evidently reduced tumor regrowth times and subsequently highly increased local tumor control under normoxic and hypoxic conditions in a xenograft mouse model.

  12. Flows and hypoxic blackwater events in managed ephemeral river channels

    NASA Astrophysics Data System (ADS)

    Hladyz, Sally; Watkins, Susanne C.; Whitworth, Kerry L.; Baldwin, Darren S.

    2011-04-01

    SummaryAs pressure increases on the availability of water resources worldwide, especially in the face of climatic change, it is probable that the likelihood of streams undergoing at least some periods of drying will increase in arid and semi-arid regions. This has implications for the ongoing management of waterways in these areas. One area of concern is the potential occurrence of hypoxic blackwater events upon re-instatement of flows in creek and river channels following periods of drying. Hypoxic blackwater events are characterised by high levels of dissolved organic carbon (DOC), the metabolism of which results in low dissolved oxygen (DO) in the water column, which can cause fish and crustacean mortality. Therefore, understanding hypoxic blackwater events is important in order to reduce the potential for fish mortalities and other water quality impacts from both managed and natural flows. In this study, we set out to determine the factors that influenced the occurrence of a hypoxic blackwater event in the Edward-Wakool river system, in southern NSW, Australia during the previous austral summer (2008-2009). Standing stocks of plant litter, emergent macrophytes and river red gum saplings ( Eucalyptus camaldulensis Dehn.), as well as rates of litterfall, were determined in dry and inundated channels. A series of mesocosm experiments were undertaken to determine which carbon source was the greatest contributor to DOC and to DO depletion, and what loadings could result in hypoxia. These experiments were then used to create a simple algorithm relating carbon loading in a dry channel to DOC in the overlying water column following inundation. Results revealed that plant litter was the main contributor to water column DOC and to DO depletion. Litter loadings equal to or greater than 370 g m -2 were found to cause DO in a shallow (20 cm) water column at 20 °C to fall to zero within two days. This loading was approximately half of that found in dry channels in the

  13. Pulmonary administration of 1,25-dihydroxyvitamin D3 to the lungs induces alveolar regeneration in a mouse model of chronic obstructive pulmonary disease.

    PubMed

    Horiguchi, Michiko; Hirokawa, Mai; Abe, Kaori; Kumagai, Harumi; Yamashita, Chikamasa

    2016-07-10

    Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disease with several causes, including smoking, and no curative therapeutic agent is available, particularly for destructive alveolar lesions. In this study, we investigated the differentiation-inducing effect on undifferentiated lung cells (Calu-6) and the alveolar regenerative effect of the active vitamin 1,25-dihydroxy vitamin D3 (VD3) with the ultimate goal of developing a novel curative drug for COPD. First, the differentiation-inducing effect of VD3 on Calu-6 cells was evaluated. Treatment with VD3 increased the proportions of type I alveolar epithelial (AT-I) and type II alveolar epithelial (AT-II) cells constituting alveoli in a concentration- and treatment time-dependent manner, demonstrating the potent differentiation-inducing activity of VD3 on Calu-6 cells. We thus administered VD3 topically to the mice lung using a previously developed intrapulmonary administration via self-inhalation method. To evaluate the alveolus-repairing effect of VD3, we administered VD3 intrapulmonarily to elastase-induced COPD model mice and computed the mean distance between the alveolar walls as an index of the extent of alveolar injury. Results showed significant decreases in the alveolar wall distance in groups of mice that received 0.01, 0.1, and 1μg/kg of intrapulmonary VD3, revealing excellent alveolus-regenerating effect of VD3. Furthermore, we evaluated the effect of VD3 on improving respiratory function using a respiratory function analyzer. Lung elasticity and respiratory competence [forced expiratory volume (FEV) 1 s %] are reduced in COPD, reflecting advanced emphysematous changes. In elastase-induced COPD model mice, although lung elasticity and respiratory competence were reduced, VD3 administered intrapulmonarily twice weekly for 2weeks recovered tissue elastance and forced expiratory volume in 0.05s to the forced vital capacity, which are indicators of lung elasticity and respiratory

  14. Development of a real-time imaging system for hypoxic cell apoptosis

    PubMed Central

    Kagiya, Go; Ogawa, Ryohei; Hyodo, Fuminori; Yamashita, Kei; Nakamura, Mizuki; Ishii, Ayumi; Sejimo, Yukihiko; Tominaga, Shintaro; Murata, Masaharu; Tanaka, Yoshikazu; Hatashita, Masanori

    2016-01-01

    Hypoxic regions within the tumor form due to imbalances between cell proliferation and angiogenesis; specifically, temporary closure or a reduced flow due to abnormal vasculature. They create environments where cancer cells acquire resistance to therapies. Therefore, the development of therapeutic approaches targeting the hypoxic cells is one of the most crucial challenges for cancer regression. Screening potential candidates for effective diagnostic modalities even under a hypoxic environment would be an important first step. In this study, we describe the development of a real-time imaging system to monitor hypoxic cell apoptosis for such screening. The imaging system is composed of a cyclic luciferase (luc) gene under the control of an improved hypoxic-responsive promoter. The cyclic luc gene product works as a caspase-3 (cas-3) monitor as it gains luc activity in response to cas-3 activation. The promoter composed of six hypoxic responsible elements and the CMV IE1 core promoter drives the effective expression of the cyclic luc gene in hypoxic conditions, enhancing hypoxic cell apoptosis visualization. We also confirmed real-time imaging of hypoxic cell apoptosis in the spheroid, which shares properties with the tumor. Thus, this constructed system could be a powerful tool for the development of effective anticancer diagnostic modalities. PMID:26966700

  15. A microfluidic device to study cancer metastasis under chronic and intermittent hypoxia

    PubMed Central

    Acosta, Miguel A.; Huang, Pin-Kang; Grant, Christine S.; Walker, Glenn M.; Gamcsik, Michael P.

    2014-01-01

    Metastatic cancer cells must traverse a microenvironment ranging from extremely hypoxic, within the tumor, to highly oxygenated, within the host's vasculature. Tumor hypoxia can be further characterized by regions of both chronic and intermittent hypoxia. We present the design and characterization of a microfluidic device that can simultaneously mimic the oxygenation conditions observed within the tumor and model the cell migration and intravasation processes. This device can generate spatial oxygen gradients of chronic hypoxia and produce dynamically changing hypoxic microenvironments in long-term culture of cancer cells. PMID:25584114

  16. Angiogenesis in the mouse lung.

    PubMed

    Mitzner, W; Lee, W; Georgakopoulos, D; Wagner, E

    2000-07-01

    When pulmonary arterial blood flow is obstructed in all mammals studied, there is a compensatory growth of the bronchial vasculature. This angiogenesis normally occurs through a proliferation of the systemic circulation to the intraparenchymal airways. It is an important pathophysiological process, not only in pulmonary vascular disease, but also in lung cancer, because the blood flow that supplies primary lung tumors arises from the systemic circulation. In the mouse, however, the systemic blood vessels that supply the trachea and mainstem bronchi do not penetrate into the intraparenchymal airways, as they do in all other larger species. In this study, we attempted to generate a new functional bronchial circulation in the mouse by permanently obstructing 40% of the pulmonary circulation. We quantified the systemic blood flow to the lung with fluorescent microspheres for 3 months after left pulmonary artery ligation. Results demonstrated that a substantial systemic blood flow to the lung that can eventually supply up to 15% of the normal pulmonary flow can be generated beginning 5-6 days after ligation. These new angiogenic vessels do not arise from the extraparenchymal bronchial circulation. Rather they enter the lung directly via a totally new vasculature that develops between the visceral and parietal pleuras, supplied by several intercostal arteries. This unique model of angiogenesis occurs in the absence of any hypoxic stimulus and mimics the vascular source of many lung tumors. PMID:10880380

  17. Increased SUMO-1 expression in response to hypoxia: Interaction with HIF-1α in hypoxic pulmonary hypertension.

    PubMed

    Jiang, Yongliang; Wang, Jing; Tian, Hua; Li, Guang; Zhu, Hao; Liu, Lei; Hu, Ruicheng; Dai, Aiguo

    2015-07-01

    Pulmonary hypertension (PH) develops in 30-70% of chronic obstructive pulmonary disease patients and increases morbidity and mortality. The present study aimed to investigate the regulation of small ubiquitin‑related modifier‑1 (SUMO‑1) expression in response to hypoxia. The experiments were carried out in vitro in rat pulmonary arterial smooth muscle cells (PASMCs) and in vivo using a rat hypoxic PH (HPH) model. A significant increase in SUMO‑1 mRNA and protein levels was observed following hypoxic stimulation in vivo and in vitro. SUMO‑1 is known to interact with various transcription factors, including hypoxia‑inducible factor‑1α (HIF‑1α) in vitro. Notably, the expression of HIF‑1α and its target gene, vascular endothelial growth factor, was increased by hypoxia in HPH. In addition, the present data suggest that SUMO‑1 regulated HIF‑1α in response to hypoxia (gene silencing and overexpression). Finally, the co‑immunoprecipitation assays suggest a direct and specific interaction between SUMO‑1 and HIF‑1α. In conclusion, SUMO‑1 may participate in the modulation of HIF‑1α through sumoylation in HPH. However, further studies are required to confirm this. PMID:25976847

  18. Clinical perspectives for the use of new hypoxic cell sensitizers

    SciTech Connect

    Brown, J.M.

    1982-09-01

    Experience with high pressure oxygen in combination with radiotherapy has shown that, for some tumors at least, the presence of hypoxic cells is a limiting factor in the ability to cure these tumors even with conventional daily fractionation. This suggests that hypoxic cell radiosensitizers, of which misonidazole (MISO) is the prototype drug, may play a role in improving the cure-rate of some tumors when combined with daily fractionation. Even for those tumors for which no improvement is seen when combined with daily fractionation, it is likely that there will be an important role for these sensitizers by using them in combination with regimens of only a few dose fractions. Because of the limiting side effects of neuropathy, a less toxic radiosensitizer than MISO is required to gain the full clinical benefit of these drugs. A possible way of achieving this is to reduce the lipid solubility (lipophilicity) of the compounds while still retaining their electron-affinity. This reduces the concentration of drug in the neural tissues (brain, peripheral nerves) without affecting the tumor concentration. However, if the lipophilicity is too low, the drugs are unable to enter the hypoxic cells and hence lose their radiosensitivity efficiency. It would appear that a lipophilicity given by an octanol:water partition coefficient of approximately 0.04 is optimum (cf. MISO = 0.43) with the 2-nitroimidazole amide SR-2508 the best in this series. Tumor levels of this drug of at least 7-8 times those obtained with MISO should be attainable clinically for no increase in neurotoxicity. Another property of electron-affinic sensitizers shows clinical promise. This is their ability to preferentially sensitize tumors compared to normal tissues to the cytotoxic action of several chemotherapeutic agents.

  19. Sirtuin 6 protects the heart from hypoxic damage

    SciTech Connect

    Maksin-Matveev, Anna; Kanfi, Yariv; Hochhauser, Edith; Isak, Ahuva; Cohen, Haim Y.; Shainberg, Asher

    2015-01-01

    Sirtuin 6 (SIRT6) is a protein associated with prolonged life expectancy. We investigated whether life extension is associated with cardioprotection against hypoxia. The proposed study is to develop approaches to reduce hypoxic damage through the use of the sirtuin pathway and to elucidate the mechanism involved. For that purpose we subjected cardiomyocytes from transgenic mice (TG) with over-expression of SIRT6, to hypoxic stress in cell cultures. We hypothesized that cardiomyocytes from transgenic mice subjected to prolonged hypoxia may release survival factors or fewer damage markers to protect them from hypoxic stress compared with wild type (WT) mice. Lactate dehydrogenase (LDH) and creatine kinase (CK) released to the medium and propidium iodide (PI) binding, were markedly decreased following hypoxia in TG cardiomyocytes. The protective mechanism of SIRT6 over-expression includes the activation of pAMPKα pathway, the increased protein level of B-cell lymphoma 2 (Bcl2), the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), the decrease of reactive oxygen species (ROS) and the reduction in the protein level of phospho-protein kinase B (pAkt) during hypoxia. Together, all these processes impede the necrosis/apoptosis pathways leading to the improved survival of cardiomyocytes following hypoxia, which might explain life extension. - Highlights: • Sirtuin 6 is a protein associated with prolonged life expectancy. • Over-expression of sirtuin 6 protects cardiocytes from hypoxia and oxidative stress. • Over-expression of sirtuin 6 activates the pAMPKα pathway and the Bcl2 expression. • Over-expression of sirtuin 6 decreases ROS formation and pAkt level during hypoxia. • These pathways protect cardiocytes from hypoxia and might explain lifespan extension.

  20. Hypoxic regulation of glycosylation via the N-acetylglucosamine cycle

    PubMed Central

    Shirato, Ken; Nakajima, Kazuki; Korekane, Hiroaki; Takamatsu, Shinji; Gao, Congxiao; Angata, Takashi; Ohtsubo, Kazuaki; Taniguchi, Naoyuki

    2011-01-01

    Glucose is an energy substrate, as well as the primary source of nucleotide sugars, which are utilized as donor substrates in protein glycosylation. Appropriate glycosylation is necessary to maintain the stability of protein, and is also important in the localization and trafficking of proteins. The dysregulation of glycosylation results in the development of a variety of disorders, such as cancer, diabetes mellitus and emphysema. Glycosylation is kinetically regulated by dynamically changing the portfolio of glycosyltransferases, nucleotide sugars, and nucleotide sugar transporters, which together form a part of what is currently referred to as the ”Glycan cycle”. An excess or a deficiency in the expression of glycosyltransferases has been shown to alter the glycosylation pattern, which subsequently leads to the onset, progression and exacerbation of a number of diseases. Furthermore, alterations in intracellular nucleotide sugar levels can also modulate glycosylation patterns. It is observed that pathological hypoxic microenvironments frequently occur in solid cancers and inflammatory foci. Hypoxic conditions dramatically change gene expression profiles, by activating hypoxia-inducible factor-1, which mediates adaptive cellular responses. Hypoxia-induced glycosyltransferases and nucleotide sugar transporters have been shown to modulate glycosylation patterns that are part of the mechanism associated with cancer metastasis. Hypoxia-inducible factor-1 also induces the expression of glucose transporters and various types of glycolytic enzymes, leading to shifts in glucose metabolic patterns. This fact strongly suggests that hypoxic conditions are an important factor in modulating various nucleotide sugar biosynthetic pathways. This review discusses some of the current thinking of how hypoxia alters glucose metabolic fluxes that can modulate cellular glycosylation patterns and consequently modify cellular functions, particularly from the standpoint of the N

  1. Dull Brains, Mountaineers, and Mosso: Hypoxic Words from on High.

    PubMed

    Lankford, Harvey V

    2015-12-01

    Dull and hypoxic brains have been a frequent subject in the medical and mountaineering literature. Deterioration of cognitive and other neurological function occurs at high altitude, with or without high altitude cerebral edema. This historical essay explores a 2014 first-ever English translation of cerebral blood flow studies by nineteenth century physiologist Angelo Mosso. Some of the medical history and physiology of brain function is discussed, but much of the style focuses on quotations from the writings of mountaineers and mountaineering physicians to provide color commentary about dull brains at high altitude. PMID:26356476

  2. Biophysical basis of hypoxic radioprotection by deoxygenated dextran-hemoglobin

    SciTech Connect

    Wong, J.T.; Hill, R.P.

    1986-08-01

    Perfusion with deoxygenated dextran-hemoglobin provides an effective method for inducing hypoxic radioprotection of normal tissues during radiation treatment of tumors. In this study, the dependence of P50, the half-saturation pressure of oxygen binding to dextran-hemoglobin, was analyzed as a function of solution temperature and pH. The variation of attainable radioprotection with P50, and with the amount of collateral blood entering into the perfused region, was calculated. Upon perfusion of canine gracilis muscle with deoxygenated dextran-hemoglobin, a rapid onset of extensive venous hypoxia was observed.

  3. Effect of Intermittent Hypoxic Training Followed by Intermittent Hypoxic Exposure on Aerobic Capacity of Long Distance Runners.

    PubMed

    Nakamoto, Fernanda P; Ivamoto, Rafael K; Andrade, Marilia Dos S; de Lira, Claudio A B; Silva, Bruno M; da Silva, Antonio C

    2016-06-01

    Nakamoto, FP, Ivamoto, RK, Andrade, MS, de Lira, CAB, Silva, BM, and da Silva, AC. Effect of intermittent hypoxic training followed by intermittent hypoxic exposure on aerobic capacity of long distance runners. J Strength Cond Res 30(6): 1708-1720, 2016-Effects of intermittent hypoxic training (IHT) are still controversial and detraining effects remain uninvestigated. Therefore, we investigated (a) whether IHT improves aerobic capacity; (b) whether aerobic detraining occurs post-IHT; and (c) whether intermittent hypoxic exposure (IHE) at rest reduces a possible aerobic detraining post-IHT. Twenty eight runners (21 men/7 women; 36 ± 2 years; maximal oxygen uptake [V[Combining Dot Above]O2max] 55.4 ± 1.3 ml·kg·min) participated in a single-blinded placebo-controlled trial. Twice a week, 1 group performed 6 weeks of IHT (n = 11), followed by 4 weeks of IHE (n = 11) at rest (IHT+IHE group). Another group performed 6 weeks of IHT (n = 10), followed by 4 weeks of normoxic exposure (NE, n = 9) at rest (IHT+NE group). A control group performed 6 weeks of normoxic training (NT, n = 7), followed by 4 weeks of NE (n = 6) at rest (NT+NE group). Hematological and submaximal/maximal aerobic measurements were conducted in normoxia at pretraining, posttraining, and postexposure. Hemoglobin concentration did not change, but lactate threshold and running economy improved in all groups at posttraining (p ≤ 0.05 vs. pretraining). Ventilatory threshold, respiratory compensation point, and V[Combining Dot Above]O2max increased after IHT (IHT+IHE group: 7.3, 5.4, and 9.2%, respectively; IHT+NE group: 10.7, 7.5, and 4.8%; p ≤ 0.05 vs. pretraining), but not after NT (-1.1, -1.0, and -3.8%; p > 0.05 vs. pretraining). Such IHT-induced adaptations were maintained at postexposure (p > 0.05 vs. postexposure). In conclusion, IHT induced further aerobic improvements than NT. These additional IHT adaptations were maintained for 4 weeks post-IHT, regardless of IHE. PMID:26562716

  4. Studies on cerebral protection of digoxin against hypoxic-ischemic brain damage in neonatal rats.

    PubMed

    Peng, Kaiwei; Tan, Danfeng; He, Miao; Guo, Dandan; Huang, Juan; Wang, Xia; Liu, Chentao; Zheng, Xiangrong

    2016-08-17

    Hypoxic-ischemic brain damage (HIBD) is a major cause of neonatal acute deaths and chronic nervous system damage. Our present study was designed to investigate the possible neuroprotective effect of digoxin-induced pharmacological preconditioning after hypoxia-ischemia and underlying mechanisms. Neonatal rats were assigned randomly to control, HIBD, or HIBD+digoxin groups. Pharmacological preconditioning was induced by administration of digoxin 72 h before inducing HIBD by carotid occlusion+hypoxia. Behavioral assays, and neuropathological and apoptotic assessments were performed to examine the effects; the expression of Na/K ATPase was also assessed. Rats in the HIBD group showed deficiencies on the T-maze, radial water maze, and postural reflex tests, whereas the HIBD+digoxin group showed significant improvements on all behavioral tests. The rats treated with digoxin showed recovery of pathological conditions, increased number of neural cells and proliferative cells, and decreased number of apoptotic cells. Meanwhile, an increased expression level of Na/K ATPase was observed after digoxin preconditioning treatment. The preconditioning treatment of digoxin contributed toward an improved functional recovery and exerted a marked neuroprotective effect including promotion of cell proliferation and reduction of apoptosis after HIBD, and the neuroprotective action was likely associated with increased expression of Na/K ATPase. PMID:27362436

  5. The G. L. Brown Prize Lecture. Hypoxic regulation of ion channel function and expression.

    PubMed

    Peers, Chris

    2002-07-01

    Acute hypoxia regulates the activity of specific ion channels in a rapid and reversible manner. Such effects underlie appropriate cellular responses to hypoxia which are designed to initiate cardiorespiratory reflexes and contribute importantly to other tissue responses, all of which are designed to improve tissue O2 supply. These responses include excitation of chemoreceptors as well as pulmonary vasoconstriction and systemic vasodilatation. However, such responses may also contribute to the adverse responses to hypoxia, such as excitotoxicity in the central nervous system. Whilst numerous ion channel types are known to be modulated by acute hypoxia, the nature of the O2 sensor in most tissues remains to be identified. Prolonged (chronic) hypoxia regulates functional expression of ion channels, and so remodels excitability of various cell types. Whilst this may contribute to adaptive responses such as high-altitude acclimatization, such altered channel expression may also contribute to the onset of pathological disorders, including Alzheimer's disease. Indeed, evidence is emerging that production of pathological peptides associated with Alzheimer's disease is increased during prolonged hypoxia. Such effects may account for the known increased incidence of this disease in patients who have previously endured hypoxic episodes, such as congestive heart failure and stroke. Identification of the mechanisms coupling hypoxia to the increased production of these peptides is likely to be of therapeutic benefit. PMID:12392105

  6. Hypoxic Tumor Environments Exhibit Disrupted Collagen I Fibers and Low Macromolecular Transport

    PubMed Central

    Kakkad, Samata M.; Penet, Marie-France; Akhbardeh, Alireza; Pathak, Arvind P.; Solaiyappan, Meiyappan; Raman, Venu; Leibfritz, Dieter; Glunde, Kristine; Bhujwalla, Zaver M.

    2013-01-01

    Hypoxic tumor microenvironments result in an aggressive phenotype and resistance to therapy that lead to tumor progression, recurrence, and metastasis. While poor vascularization and the resultant inadequate drug delivery are known to contribute to drug resistance, the effect of hypoxia on molecular transport through the interstitium, and the role of the extracellular matrix (ECM) in mediating this transport are unexplored. The dense mesh of fibers present in the ECM can especially influence the movement of macromolecules. Collagen 1 (Col1) fibers form a key component of the ECM in breast cancers. Here we characterized the influence of hypoxia on macromolecular transport in tumors, and the role of Col1 fibers in mediating this transport using an MDA-MB-231 breast cancer xenograft model engineered to express red fluorescent protein under hypoxia. Magnetic resonance imaging of macromolecular transport was combined with second harmonic generation microscopy of Col1 fibers. Hypoxic tumor regions displayed significantly decreased Col1 fiber density and volume, as well as significantly lower macromolecular draining and pooling rates, than normoxic regions. Regions adjacent to severely hypoxic areas revealed higher deposition of Col1 fibers and increased macromolecular transport. These data suggest that Col1 fibers may facilitate macromolecular transport in tumors, and their reduction in hypoxic regions may reduce this transport. Decreased macromolecular transport in hypoxic regions may also contribute to poor drug delivery and tumor recurrence in hypoxic regions. High Col1 fiber density observed around hypoxic regions may facilitate the escape of aggressive cancer cells from hypoxic regions. PMID:24349142

  7. Correlation between drug uptake and selective toxicity of porfiromycin to hypoxic EMT6 cells.

    PubMed

    Keyes, S R; Rockwell, S; Sartorelli, A C

    1987-11-01

    Mitomycin C and its methylated analogue porfiromycin (Por) have significant potential as adjuncts to regimens presently used for treating solid tumors because of their preferential toxicity to cells existing in an hypoxic environment. An understanding of the factors producing the differential activity of these drugs under aerobic and hypoxic conditions would facilitate the development of new agents of this class. Previous studies have focused on the enzymes that reductively activate the mitomycins and on the interaction of these drugs with DNA; none of these studies has fully explained the differences in cytotoxicity observed under hypoxic and aerobic conditions. The present investigation demonstrates that the rate of Por uptake is directly correlated with cytotoxicity under both aerobic and hypoxic conditions. Uptake of Por into hypoxic cells is more rapid than into aerobic cells at equal drug concentrations. Hypoxic cells also accumulate drug in concentrations well in excess of those in the extracellular medium; this is apparently a reflection of drug sequestration in these cells. This sequestration of Por, which affects the rate and extent of uptake in hypoxic cells, does not take place in aerobic cells. The failure of aerobic cells to sequester drug is evidenced by the very rapid efflux of Por from these cells upon removal of extracellular Por and by the fact that aerobic cells attain a state of equilibrium between the intracellular and extracellular drug concentrations. The findings demonstrate that differences in the uptake and retention of Por are associated with the preferential toxicity of Por to hypoxic cells. PMID:3664473

  8. Least-cost control of agricultural nutrient contributions to the Gulf of Mexico hypoxic zone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2007, the hypoxic zone in the Gulf of Mexico, measuring 20,720 km**2, was one of the two largest reported since measurement of the zone began in 1985. The extent of the hypoxic zone is related to nitrogen and phosphorous loadings originating on agricultural fields in the upper Midwest. This stud...

  9. Ionic storm in hypoxic/ischemic stress: Can opioid receptors subside it?

    PubMed Central

    Chao, Dongman; Xia, Ying

    2010-01-01

    Neurons in the mammalian central nervous system are extremely vulnerable to oxygen deprivation and blood supply insufficiency. Indeed, hypoxic/ischemic stress triggers multiple pathophysiological changes in the brain, forming the basis of hypoxic/ischemic encephalopathy. One of the initial and crucial events induced by hypoxia/ischemia is the disruption of ionic homeostasis characterized by enhanced K+ efflux and Na+-, Ca2+- and Cl− influx, which causes neuronal injury or even death. Recent data from our laboratory and those of others have shown that activation of opioid receptors, particularly δ-opioid receptors (DOR), is neuroprotective against hypoxic/ischemic insult. This protective mechanism may be one of the key factors that determine neuronal survival under hypoxic/ischemic condition. An important aspect of the DOR-mediated neuroprotection is its action against hypoxic/ischemic disruption of ionic homeostasis. Specially, DOR signal inhibits Na+ influx through the membrane and reduces the increase in intracellular Ca2+, thus decreasing the excessive leakage of intracellular K+. Such protection is dependent on a PKC-dependent and PKA-independent signaling pathway. Furthermore, our novel exploration shows that DOR attenuates hypoxic/ischemic disruption of ionic homeostasis through the inhibitory regulation of Na+ channels. In this review, we will first update current information regarding the process and features of hypoxic/ischemic disruption of ionic homeostasis and then discuss the opioid-mediated regulation of ionic homeostasis, especially in hypoxic/ischemic condition, and the underlying mechanisms. PMID:20036308

  10. Plasticity in the Neonatal Brain following Hypoxic-Ischaemic Injury.

    PubMed

    Rocha-Ferreira, Eridan; Hristova, Mariya

    2016-01-01

    Hypoxic-ischaemic damage to the developing brain is a leading cause of child death, with high mortality and morbidity, including cerebral palsy, epilepsy, and cognitive disabilities. The developmental stage of the brain and the severity of the insult influence the selective regional vulnerability and the subsequent clinical manifestations. The increased susceptibility to hypoxia-ischaemia (HI) of periventricular white matter in preterm infants predisposes the immature brain to motor, cognitive, and sensory deficits, with cognitive impairment associated with earlier gestational age. In term infants HI causes selective damage to sensorimotor cortex, basal ganglia, thalamus, and brain stem. Even though the immature brain is more malleable to external stimuli compared to the adult one, a hypoxic-ischaemic event to the neonate interrupts the shaping of central motor pathways and can affect normal developmental plasticity through altering neurotransmission, changes in cellular signalling, neural connectivity and function, wrong targeted innervation, and interruption of developmental apoptosis. Models of neonatal HI demonstrate three morphologically different types of cell death, that is, apoptosis, necrosis, and autophagy, which crosstalk and can exist as a continuum in the same cell. In the present review we discuss the mechanisms of HI injury to the immature brain and the way they affect plasticity. PMID:27047695

  11. Plasticity in the Neonatal Brain following Hypoxic-Ischaemic Injury

    PubMed Central

    Rocha-Ferreira, Eridan

    2016-01-01

    Hypoxic-ischaemic damage to the developing brain is a leading cause of child death, with high mortality and morbidity, including cerebral palsy, epilepsy, and cognitive disabilities. The developmental stage of the brain and the severity of the insult influence the selective regional vulnerability and the subsequent clinical manifestations. The increased susceptibility to hypoxia-ischaemia (HI) of periventricular white matter in preterm infants predisposes the immature brain to motor, cognitive, and sensory deficits, with cognitive impairment associated with earlier gestational age. In term infants HI causes selective damage to sensorimotor cortex, basal ganglia, thalamus, and brain stem. Even though the immature brain is more malleable to external stimuli compared to the adult one, a hypoxic-ischaemic event to the neonate interrupts the shaping of central motor pathways and can affect normal developmental plasticity through altering neurotransmission, changes in cellular signalling, neural connectivity and function, wrong targeted innervation, and interruption of developmental apoptosis. Models of neonatal HI demonstrate three morphologically different types of cell death, that is, apoptosis, necrosis, and autophagy, which crosstalk and can exist as a continuum in the same cell. In the present review we discuss the mechanisms of HI injury to the immature brain and the way they affect plasticity. PMID:27047695

  12. Harnessing hypoxic adaptation to prevent, treat, and repair stroke.

    PubMed

    Ratan, Rajiv R; Siddiq, Ambreena; Smirnova, Natalya; Karpisheva, Ksenia; Haskew-Layton, Renee; McConoughey, Stephen; Langley, Brett; Estevez, Alvaro; Huerta, Patricio T; Volpe, Bruce; Roy, Sashwati; Sen, Chandan K; Gazaryan, Irina; Cho, Sunghee; Fink, Matthew; LaManna, Joseph

    2007-12-01

    The brain demands oxygen and glucose to fulfill its roles as the master regulator of body functions as diverse as bladder control and creative thinking. Chemical and electrical transmission in the nervous system is rapidly disrupted in stroke as a result of hypoxia and hypoglycemia. Despite being highly evolved in its architecture, the human brain appears to utilize phylogenetically conserved homeostatic strategies to combat hypoxia and ischemia. Specifically, several converging lines of inquiry have demonstrated that the transcription factor hypoxia-inducible factor-1 (HIF1-1) mediates the activation of a large cassette of genes involved in adaptation to hypoxia in surviving neurons after stroke. Accordingly, pharmacological or molecular approaches that engage hypoxic adaptation at the point of one of its sensors (e.g., inhibition of HIF prolyl 4 hydroxylases) leads to profound sparing of brain tissue and enhanced recovery of function. In this review, we discuss the potential mechanisms that could subserve protective and restorative effects of augmenting hypoxic adaptation in the brain. The strategy appears to involve HIF-dependent and HIF-independent pathways and more than 70 genes and proteins activated transcriptionally and post-transcriptionally that can act at cellular, local, and system levels to compensate for oxygen insufficiency. The breadth and depth of this homeostatic program offers a hopeful alternative to the current pessimism towards stroke therapeutics. PMID:18043901

  13. Harnessing hypoxic adaptation to prevent, treat, and repair stroke

    PubMed Central

    Siddiq, Ambreena; Smirnova, Natalya; Karpisheva, Ksenia; Haskew-Layton, Renee; McConoughey, Stephen; Langley, Brett; Estevez, Alvaro; Huerta, Patricio T.; Volpe, Bruce; Roy, Sashwati; Sen, Chandan K.; Gazaryan, Irina; Cho, Sunghee; Fink, Matthew; LaManna, Joseph

    2007-01-01

    The brain demands oxygen and glucose to fulfill its roles as the master regulator of body functions as diverse as bladder control and creative thinking. Chemical and electrical transmission in the nervous system is rapidly disrupted in stroke as a result of hypoxia and hypoglycemia. Despite being highly evolved in its architecture, the human brain appears to utilize phylogenetically conserved homeostatic strategies to combat hypoxia and ischemia. Specifically, several converging lines of inquiry have demonstrated that the transcription factor hypoxia-inducible factor-1 (HIF1-1) mediates the activation of a large cassette of genes involved in adaptation to hypoxia in surviving neurons after stroke. Accordingly, pharmacological or molecular approaches that engage hypoxic adaptation at the point of one of its sensors (e.g., inhibition of HIF prolyl 4 hydroxylases) leads to profound sparing of brain tissue and enhanced recovery of function. In this review, we discuss the potential mechanisms that could subserve protective and restorative effects of augmenting hypoxic adaptation in the brain. The strategy appears to involve HIF-dependent and HIF-independent pathways and more than 70 genes and proteins activated transcriptionally and post-transcriptionally that can act at cellular, local, and system levels to compensate for oxygen insufficiency. The breadth and depth of this homeostatic program offers a hopeful alternative to the current pessimism towards stroke therapeutics. PMID:18043901

  14. Effects of hypoxic preconditioning on synaptic ultrastructure in mice.

    PubMed

    Liu, Yi; Sun, Zhishan; Sun, Shufeng; Duan, Yunxia; Shi, Jingfei; Qi, Zhifeng; Meng, Ran; Sun, Yongxin; Zeng, Xianwei; Chui, Dehua; Ji, Xunming

    2015-01-01

    Hypoxic preconditioning (HPC) elicits resistance to more drastic subsequent insults, which potentially provide neuroprotective therapeutic strategy, but the underlying mechanisms remain to be fully elucidated. Here, we examined the effects of HPC on synaptic ultrastructure in olfactory bulb of mice. Mice underwent up to five cycles of repeated HPC treatments, and hypoxic tolerance was assessed with a standard gasp reflex assay. As expected, HPC induced an increase in tolerance time. To assess synaptic responses, Western blots were used to quantify protein levels of representative markers for glia, neuron, and synapse, and transmission electron microscopy was used to examine synaptic ultrastructure and mitochondrial density. HPC did not significantly alter the protein levels of astroglial marker (GFAP), neuron-specific markers (GAP43, Tuj-1, and OMP), synaptic number markers (synaptophysin and SNAP25) or the percentage of excitatory synapses versus inhibitory synapses. However, HPC significantly affected synaptic curvature and the percentage of synapses with presynaptic mitochondria, which showed concomitant change pattern. These findings demonstrate that HPC is associated with changes in synaptic ultrastructure. PMID:25155519

  15. Stromal cell-derived factor-1 promotes human adipose tissue-derived stem cell survival and chronic wound healing

    PubMed Central

    LI, QIANG; GUO, YANPING; CHEN, FEIFEI; LIU, JING; JIN, PEISHENG

    2016-01-01

    Adipose tissue-derived stem cells (ADSCs) hold great potential for the stem cell-based therapy of cutaneous wound healing. Stromal cell-derived factor-1 (SDF-1) activates CXC chemokine receptor (CXCR)4+ and CXCR7+ cells and plays an important role in wound healing. Increasing evidence suggests a critical role for SDF-1 in cell apoptosis and the survival of mesenchymal stem cells. However, the function of SDF-1 in the apoptosis and wound healing ability of ADSCs is not well understood. The aim of this study was to analyze the effect of SDF-1 on the apoptosis and therapeutic effect of ADSCs in cutaneous chronic wounds in vitro and in vivos. By flow cytometric analysis, it was found that hypoxia and serum free promoted the apoptosis of ADSCs. When pretreated with SDF-1, the apoptosis of ADSCs induced by hypoxia and serum depletion was partly recovered. Furthermore, in vivo experiments established that the post-implantation cell survival and chronic wound healing ability of ADSCs were increased following pretreatment with SDF-1 in a diabetic mouse model of chronic wound healing. To explore the potential mechanism underlying the effect of SDF-1 on ADSC apoptosis, western blot analysis was employed and the results indicate that SDF-1 may protect against cell apoptosis in hypoxic and serum-free conditions through activation of the caspase signaling pathway in ADSCs. This study provides evidence that SDF-1 pretreatment can increase the therapeutic effect of ADSCs in cutaneous chronic wounds in vitro and in vivo. PMID:27347016

  16. Hypoxic stress inhibits multiple aspects of the potato tuber wound response. [Solanum tuberosum L

    SciTech Connect

    Butler, W.; Cook, L.; Vayda, M.E. )

    1990-05-01

    Potato (Solanum tuberosum L.) tubers subjected to wounding under hypoxic stress do not synthesize RNA species that are induced in response to wounding in aerobic conditions. Further, wound-response proteins fail to be synthesized when wounded tubers are transferred to hypoxic conditions although messenger RNAs which encode them persist for many hours after transfer. Hypoxic stress also prevents the incorporation of ({sup 3}H)thymidine by wounded tubers that occurs in aerobic conditions. In contrast, hypoxic tubers accumulate and translate transcripts of genes whose products are involved in anaerobic metabolism whether or not they are wounded. Both the hypoxic response and the aerobic wound response preclude the synthesis of proteins encoded by messenger RNAs which accumulated during the tuberization process and which can be translated in vitro. Finally, wounding elicits the degradation of a subset of these tuberization-associated transcripts. These data indicate a complex and precise regulation of gene expression at several levels of macromolecular synthesis.

  17. Reconstitution activity of hypoxic cultured human cord blood CD34-positive cells in NOG mice

    SciTech Connect

    Shima, Haruko; Takubo, Keiyo; Iwasaki, Hiroko; Yoshihara, Hiroki; Gomei, Yumiko; Hosokawa, Kentaro; Arai, Fumio; Takahashi, Takao; Suda, Toshio

    2009-01-16

    Hematopoietic stem cells (HSCs) reside in hypoxic areas of the bone marrow. However, the role of hypoxia in the maintenance of HSCs has not been fully characterized. We performed xenotransplantation of human cord blood cells cultured in hypoxic or normoxic conditions into adult NOD/SCID/IL-2R{gamma}{sup null} (NOG) mice. Hypoxic culture (1% O{sub 2}) for 6 days efficiently supported the maintenance of HSCs, although cell proliferation was suppressed compared to the normoxic culture. In contrast, hypoxia did not affect in vitro colony-forming ability. Upregulation of a cell cycle inhibitor, p21, was observed in hypoxic culture. Immunohistochemical analysis of recipient bone marrow revealed that engrafted CD34{sup +}CD38{sup -} cord blood HSCs were hypoxic. Taken together, these results demonstrate the significance of hypoxia in the maintenance of quiescent human cord blood HSCs.

  18. Functional and molecular factors associated with TAPSE in hypoxic pulmonary hypertension.

    PubMed

    Crnkovic, Slaven; Schmidt, Albrecht; Egemnazarov, Bakytbek; Wilhelm, Jochen; Marsh, Leigh M; Ghanim, Bahil; Klepetko, Walter; Olschewski, Andrea; Olschewski, Horst; Kwapiszewska, Grazyna

    2016-07-01

    Adaptation of the right ventricle (RV) to increased afterload is crucial for survival in pulmonary hypertension (PH), but it is challenging to assess RV function and identify associated molecular mechanisms. The aim of the current study was to analyze the relationship between invasive and noninvasive parameters of RV morphology and function and associated molecular changes. The response of mice to normobaric hypoxia was assessed by hechocardiography, invasive hemodynamics, and histological and molecular analyses. Plasma levels of possibly novel markers of RV remodeling were measured by ELISA in patients with idiopathic pulmonary arterial hypertension (IPAH) and matched healthy controls. Chronic hypoxia-induced PH was accompanied by significantly decreased tricuspid annular plane systolic excursion (TAPSE) and unchanged RV contractility index and tau. RV hypertrophy was present without an increase in fibrosis. There was no change in α- and β-major histocompatibility class or natriuretic peptides expression. Comparative microarray analysis identified two soluble factors, fibroblast growth factor-5 (FGF5) and interleukin-22 receptor alpha-2 (IL22RA2), as being possibly associated with RV remodeling. We observed significantly higher plasma levels of IL22RA2, but not FGF5, in patients with IPAH. Hypoxic pulmonary hypertension in a stage of RV remodeling with preserved systolic function is associated with decreased pulmonary vascular compliance, mild diastolic RV dysfunction, and significant decrease in TAPSE. Subtle gene expression changes in the RV vs. the left ventricle upon chronic hypoxia suggest that the majority of changes are due to hypoxia and not due to changes in afterload. Increased IL22RA2 levels might represent a novel RV adaptive mechanism. PMID:27106290

  19. Acetazolamide and chronic hypoxia: effects on haemorheology and pulmonary haemodynamics.

    PubMed

    Pichon, Aurélien; Connes, Philippe; Quidu, Patricia; Marchant, Dominique; Brunet, Julien; Levy, Bernard I; Vilar, José; Safeukui, Innocent; Cymbalista, Florence; Maignan, Maxime; Richalet, Jean-Paul; Favret, Fabrice

    2012-12-01

    We tested the effect of acetazolamide on blood mechanical properties and pulmonary vascular resistance (PVR) during chronic hypoxia. Six groups of rats were either treated or not treated with acetazolamide (curative: treated after 10 days of hypoxic exposure; preventive: treated before hypoxic exposure with 40 mg · kg(-1) · day(-1)) and either exposed or not exposed to 3 weeks of hypoxia (at altitude >5,500 m). They were then used to assess the role of acetazolamide on pulmonary artery pressure, cardiac output, blood volume, haematological and haemorheological parameters. Chronic hypoxia increased haematocrit, blood viscosity and PVR, and decreased cardiac output. Acetazolamide treatment in hypoxic rats decreased haematocrit (curative by -10% and preventive by -11%), PVR (curative by -36% and preventive by -49%) and right ventricular hypertrophy (preventive -20%), and increased cardiac output (curative by +60% and preventive by +115%). Blood viscosity was significantly decreased after curative acetazolamide treatment (-16%) and was correlated with PVR (r=0.87, p<0.05), suggesting that blood viscosity could influence pulmonary haemodynamics. The fall in pulmonary vascular hindrance (curative by -27% and preventive by -45%) after treatment suggests that acetazolamide could decrease pulmonary vessels remodelling under chronic hypoxia. The effect of acetazolamide is multifactorial by acting on erythropoiesis, pulmonary circulation, haemorheological properties and cardiac output, and could represent a pertinent treatment of chronic mountain sickness. PMID:22523353

  20. Short intermittent hypoxic exposures augment ventilation but do not alter regional cerebral and muscle oxygenation during hypoxic exercise.

    PubMed

    Debevec, Tadej; Mekjavic, Igor B

    2012-04-30

    This study investigated the effects of four exposures to normobaric hypoxia (SIH group; FIO₂ = 0.120, N=10) or placebo-control normoxia (Control group; FIO₂ = 0.209, N=9) on cardio-respiratory responses to hypoxic exercise. Before and after the exposures all subjects performed a constant power test (CP) to exhaustion in hypoxia FIO₂ = 0.120 at a work load corresponding to 75% of previously determined normoxic VO₂ peak. Arterial oxygen saturation (SPO₂) and minute ventilation (V(E)) were measured continuously. NIRS was used to monitor regional changes in oxygenated, de-oxygenated and total hemoglobin concentrations of the frontal cortex, vastus lateralis and serratus anterior. Although neither group improved CP time, the SIH group exhibited increases in both V(E) (+15%; P<0.05) and SPO₂ (+4%; P<0.05) after intermittent hypoxia. No physiologically significant differences were observed during exercise in vastus lateralis, serratus anterior and cerebral oxygenation between groups and testing periods. These data suggest that normobaric SIH enhances hypoxic exercise V(E) and SPO₂ without affecting regional oxygenation or time to exhaustion. PMID:22406250

  1. β2-Adrenergic Receptor-Dependent Attenuation of Hypoxic Pulmonary Vasoconstriction Prevents Progression of Pulmonary Arterial Hypertension in Intermittent Hypoxic Rats

    PubMed Central

    Nagai, Hisashi; Kuwahira, Ichiro; Schwenke, Daryl O.; Tsuchimochi, Hirotsugu; Nara, Akina; Inagaki, Tadakatsu; Ogura, Sayoko; Fujii, Yutaka; Umetani, Keiji; Shimosawa, Tatsuo; Yoshida, Ken-ichi; Pearson, James T.; Uemura, Koichi; Shirai, Mikiyasu

    2014-01-01

    In sleep apnea syndrome (SAS), intermittent hypoxia (IH) induces repeated episodes of hypoxic pulmonary vasoconstriction (HPV) during sleep, which presumably contribute to pulmonary arterial hypertension (PAH). However, the prevalence of PAH was low and severity is mostly mild in SAS patients, and mild or no right ventricular hypertrophy (RVH) was reported in IH-exposed animals. The question then arises as to why PAH is not a universal finding in SAS if repeated hypoxia of sufficient duration causes cycling HPV. In the present study, rats underwent IH at a rate of 3 min cycles of 4–21% O2 for 8 h/d for 6w. Assessment of diameter changes in small pulmonary arteries in response to acute hypoxia and drugs were performed using synchrotron radiation microangiography on anesthetized rats. In IH-rats, neither PAH nor RVH was observed and HPV was strongly reversed. Nadolol (a hydrophilic β1, 2-blocker) augmented the attenuated HPV to almost the same level as that in N-rats, but atenolol (a hydrophilic β1-blocker) had no effect on the HPV in IH. These β-blockers had almost no effect on the HPV in N-rats. Chronic administration of nadolol during 6 weeks of IH exposure induced PAH and RVH in IH-rats, but did not in N-rats. Meanwhile, atenolol had no effect on morphometric and hemodynamic changes in N and IH-rats. Protein expression of the β1-adrenergic receptor (AR) was down-regulated while that of β2AR was preserved in pulmonary arteries of IH-rats. Phosphorylation of p85 (chief component of phosphoinositide 3-kinase (PI3K)), protein kinase B (Akt), and endothelial nitric oxide synthase (eNOS) were abrogated by chronic administration of nadolol in the lung tissue of IH-rats. We conclude that IH-derived activation of β2AR in the pulmonary arteries attenuates the HPV, thereby preventing progression of IH-induced PAH. This protective effect may depend on the β2AR-Gi mediated PI3K/Akt/eNOS signaling pathway. PMID:25350545

  2. Sympathoadrenal responses to acute and chronic hypoxia in the rat.

    PubMed Central

    Johnson, T S; Young, J B; Landsberg, L

    1983-01-01

    The sympathoadrenal responses to acute and chronic hypoxic exposure at 10.5 and 7.5% oxygen were determined in the rat. Cardiac norepinephrine (NE) turnover was used to assess sympathetic nervous system (SNS) activity, and urinary excretion of epinephrine (E) was measured as an index of adrenal medullary activity. The responses of the adrenal medulla and SNS were distinct and dependent upon the degree and duration of hypoxic exposure. Chronic hypoxia at 10.5% oxygen increased cardiac NE turnover by 130% after 3, 7, and 14 d of hypoxic exposure. Urinary excretion of NE was similarly increased over this time interval, while urinary E excretion was marginally elevated. In contrast, acute exposure to moderate hypoxia at 10.5% oxygen was not associated with an increase in SNS activity; in fact, decreased SNS activity was suggested by diminished cardiac NE turnover and urinary NE excretion over the first 12 h of hypoxic exposure, and by a rebound increase in NE turnover after reexposure to normal oxygen tension. Adrenal medullary activity, on the other hand, increased substantially during acute exposure to moderate hypoxia (2-fold increase in urinary E excretion) and severe hypoxia (greater than 10-fold). In distinction to the lack of effect of acute hypoxic exposure (10.5% oxygen), the SNS was markedly stimulated during the first day of hypoxia exposure at 7.5% oxygen, an increase that was sustained throughout at least 7 d at 7.5% oxygen. These results demonstrate that chronic exposure to moderate and severe hypoxia increases the activity of the SNS and adrenal medulla, the effect being greater in severe hypoxic exposure. The response to acute hypoxic exposure is more complicated; during the first 12 h of exposure at 10.5% oxygen, the SNS is not stimulated and appears to be restrained, while adrenal medullary activity is enhanced. Acute exposure to a more severe degree of hypoxia (7.5% oxygen), however, is associated with stimulation of both the SNS and adrenal medulla

  3. High-resolution photoacoustic tomography of resting-state functional connectivity in the mouse brain

    PubMed Central

    Nasiriavanaki, Mohammadreza; Xia, Jun; Wan, Hanlin; Bauer, Adam Quentin; Culver, Joseph P.; Wang, Lihong V.

    2014-01-01

    The increasing use of mouse models for human brain disease studies presents an emerging need for a new functional imaging modality. Using optical excitation and acoustic detection, we developed a functional connectivity photoacoustic tomography system, which allows noninvasive imaging of resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight functional regions, including the olfactory bulb, limbic, parietal, somatosensory, retrosplenial, visual, motor, and temporal regions, as well as in several subregions. The borders and locations of these regions agreed well with the Paxinos mouse brain atlas. By subjecting the mouse to alternating hyperoxic and hypoxic conditions, strong and weak functional connectivities were observed, respectively. In addition to connectivity images, vascular images were simultaneously acquired. These studies show that functional connectivity photoacoustic tomography is a promising, noninvasive technique for functional imaging of the mouse brain. PMID:24367107

  4. Microfluidic Platform Generates Oxygen Landscapes for Localized Hypoxic Activation

    PubMed Central

    Rexius, Megan L.; Mauleon, Gerardo; Malik, Asrar B.; Rehman, Jalees; Eddington, David T.

    2014-01-01

    An open-well microfluidic platform generates an oxygen landscape using gas-perfused networks which diffuse across a membrane. The device enables real-time analysis of cellular and tissue responses to oxygen tension to define how cells adapt to heterogeneous oxygen conditions found in the physiological setting. We demonstrate that localized hypoxic activation of cells elicited specific metabolic and gene responses in human microvascular endothelial cells and bone marrow-derived mesenchymal stem cells. A robust demonstration of the compatibility of the device with standard laboratory techniques demonstrates the wide utility of the method. This platform is ideally suited to study real-time cell responses and cell-cell interactions within physiologically relevant oxygen landscapes. PMID:25315003

  5. Accumulation of p62 in degenerated spinal cord under chronic mechanical compression

    PubMed Central

    Tanabe, Fumito; Yone, Kazunori; Kawabata, Naoya; Sakakima, Harutoshi; Matsuda, Fumiyo; Ishidou, Yasuhiro; Maeda, Shingo; Abematsu, Masahiko; Komiya, Setsuro

    2011-01-01

    Intracellular accumulation of altered proteins, including p62 and ubiquitinated proteins, is the basis of most neurodegenerative disorders. The relationship among the accumulation of altered proteins, autophagy, and spinal cord dysfunction by cervical spondylotic myelopathy has not been clarified. We examined the expression of p62 and autophagy markers in the chronically compressed spinal cord of tiptoe-walking Yoshimura mice. In addition, we examined the expression and roles of p62 and autophagy in hypoxic neuronal cells. Western blot analysis showed the accumulation of p62, ubiquitinated proteins, and microtubule-associated protein 1 light chain 3 (LC3), an autophagic marker, in the compressed spinal cord. Immunohistochemical examinations showed that p62 accumulated in neurons, axons, astrocytes, and oligodendrocytes. Electron microscopy showed the expression of autophagy markers, including autolysosomes and autophagic vesicles, in the compressed spinal cord. These findings suggest the presence of p62 and autophagy in the degenerated compressed spinal cord. Hypoxic stress increased the expression of p62, ubiquitinated proteins, and LC3-II in neuronal cells. In addition, LC3 turnover assay and GFP-LC3 cleavage assay showed that hypoxic stress increased autophagy flux in neuronal cells. These findings suggest that hypoxic stress induces accumulation of p62 and autophagy in neuronal cells. The forced expression of p62 decreased the number of neuronal cells under hypoxic stress. These findings suggest that p62 accumulation under hypoxic stress promotes neuronal cell death. Treatment with 3-methyladenine, an autophagy inhibitor decreased the number of neuronal cells, whereas lithium chloride, an autophagy inducer increased the number of cells under hypoxic stress. These findings suggest that autophagy promotes neuronal cell survival under hypoxic stress. Our findings suggest that pharmacological inducers of autophagy may be useful for treating cervical spondylotic

  6. Cardiovascular side effects of inhaled salbutamol in hypoxic asthmatic patients

    PubMed Central

    Burggraaf, J; Westendorp, R; Veen, J; Schoemaker, R; Sterk, P; Cohen, A; Blauw, G

    2001-01-01

    BACKGROUND—Beta-2 adrenoceptor agonists have been associated with sudden death in asthma patients but the cause and underlying mechanism are unclear. Animal experiments indicate that the combination of hypoxia and β2 agonists may result in detrimental cardiovascular effects. A study was undertaken to investigate the effect of hypoxia on the systemic vascular effects of salbutamol in patients with asthma who are hypoxic by assessing forearm blood flow (FBF) as a measure of peripheral vasodilatation.
METHODS—Eight men with mild asthma underwent the following treatments: normoxia + placebo (NP), normoxia + salbutamol (NS), hypoxia+ placebo (HP), and hypoxia + salbutamol (HS). The period of mask breathing started at t=0 minutes, lasted for 60 minutes, and at 30 minutes 800 µg salbutamol was inhaled. The experiment was completed 30 minutes after the inhalation (t=60 minutes). For the hypoxia treatment the SpO2 level was 82%. Differences between treatments were sought using factorial ANOVA on percentage change from the pretreatment value.
RESULTS—There were no significant differences in blood pressure and potassium levels between the treatments. After 60 minutes the increase in FBF was 13% (95% CI -12 to 39) more for HP treatment than for NP, 21% (95% CI -5 to 46) more for NS than for NP, and 32% (95% CI 7 to 58) more for HS than for HP (p=0.016). The inhalation of salbutamol during hypoxia resulted in a significant increase in FBF of 45% (95% CI 20 to 71) compared with NP (p=0.001).
CONCLUSION—Patients with asthma who are hypoxic and inhale β2 agonists have serious systemic vascular side effects which may be an additional explanation for the association between asthma treatment and sudden death.

 PMID:11413357

  7. Buyanghuanwu Tang therapy for neonatal rats with hypoxic ischemic encephalopathy

    PubMed Central

    Liu, Xiyao; Min, Yue; Gu, Weiwang; Wang, Yujue; Tian, Yuguang

    2015-01-01

    Background: Neonatal hypoxic-ischemic encephalopathy (HIE) is a clinical syndrome manifested by neurological symptoms in the first days of life in term infants. Purpose: To investigate the therapy effect of Buyanghuanwu Tang (BYHWT), a decoction with 7 herbal ingredients, on neonatal rats with hypoxic ischemic encephalopathy (HIE) and its mechanism. Methods: 50 3-week male Sprague-Dawley rats were divided into normal control group, model group, BYHWT 1d group, BYHWT 3d group and BYHWT 7d group, 10 rats in each group. The HIE model of was established in later 4 groups. The later 3 groups were treated with BYHWT for 1, 3 and 7 days, respectively, and the normal control group and model group were treated with PBS. The Morris water maze test and dynamic 18F-FDG-PET/CT imaging were performed. The changes of hippocampal tissue observed by histopathologic examination, and the expressions of JNK1/JNK2 and TNF-α protein were observed western blotting. Results: Compared with model group, the impaired performance on distance and latency parameters was mitigated in BYHWT 1d group, BYHWT 3d group and BYHWT 7d group (P < 0.01), the FDG uptake was decreased in BYHWT 3d group and BYHWT 7d group, the apoptotic cells and inflammatory cells were significantly decreased in BYHWT 3d group and BYHWT 7d group, and the expressions of JNK1/JNK2 and TNF-α protein were significantly decreased in BYHWT 7d group (P < 0.05). Conclusion: BYHWT can delay the HIE onset and preserve the motor function, primarily by regulating inflammation, apoptosis and inhibition by mediating JNK signaling. PMID:26770451

  8. Role of Mitochondria in Neonatal Hypoxic-Ischemic Brain Injury

    PubMed Central

    Lu, Yujiao; Tucker, Donovan; Dong, Yan; Zhao, Ningjun; Zhuo, Xiaoying; Zhang, Quanguang

    2016-01-01

    Hypoxic-ischemia (HI) causes severe brain injury in neonates. It’s one of the leading causes to neonatal death and pediatric disability, resulting in devastating consequences, emotionally and economically, to their families. A series of events happens in this process, e.g. excitatory transmitter release, extracelluar Ca2+ influxing, mitochondrial dysfunction, energy failure, and neuron death. There are two forms of neuron death after HI insult: necrosis and apoptosis, apoptosis being the more prevalent form. Mitochondria handle a series of oxidative reactions, and yield energy for various cellular activities including the maintainance of membrane potential and preservation of intracellular ionic homeostasis. Therefore mitochondria play a critical role in neonatal neurodegeneration following HI, and mitochondrial dysfunction is the key point in neurodegenerative evolution. Because of this, exploring effective mitochondria-based clinical strategies is crucial. Today the only efficacious clinic treatment is hypothermia. However, due to its complex management, clinical complication and autoimmune decrease, its clinical application is limited. So far, many mitochondria-based strategies have been reported neuroprotective in animal models, which offers promise on neonatal therapy. However, since their clinical effectiveness are still unclear, plenty of studies need to be continued in the future. According to recent reports, two novel strategies have been proposed: methylene blue (MB) and melatonin. Although they are still in primary stage, the underlying mechanisms indicate promising clinical applications. Every neurological therapeutic strategy has its intrinsic deficit and limited efficacy, therefore in the long run, the perfect clinical therapy for hypoxic-ischemic neonatal brain injury will be based on the combination of multiple strategies. PMID:27441209

  9. Oxygen supply maps for hypoxic microenvironment visualization in prostate cancer

    PubMed Central

    Rupp, Niels J.; Schüffler, Peter J.; Zhong, Qing; Falkner, Florian; Rechsteiner, Markus; Rüschoff, Jan H.; Fankhauser, Christian; Drach, Matthias; Largo, Remo; Tremp, Mathias; Poyet, Cedric; Sulser, Tullio; Kristiansen, Glen; Moch, Holger; Buhmann, Joachim; Müntener, Michael; Wild, Peter J.

    2016-01-01

    Background: Intratumoral hypoxia plays an important role with regard to tumor biology and susceptibility to radio- and chemotherapy. For further investigation of hypoxia-related changes, areas of certain hypoxia must be reliably detected within cancer tissues. Pimonidazole, a 2-nitroimindazole, accumulates in hypoxic tissue and can be easily visualized using immunohistochemistry. Materials and Methods: To improve detection of highly hypoxic versus normoxic areas in prostate cancer, immunoreactivity of pimonidazole and a combination of known hypoxia-related proteins was used to create computational oxygen supply maps of prostate cancer. Pimonidazole was intravenously administered before radical prostatectomy in n = 15 patients, using the da Vinci robot-assisted surgical system. Prostatectomy specimens were immediately transferred into buffered formaldehyde, fixed overnight, and completely embedded in paraffin. Pimonidazole accumulation and hypoxia-related protein expression were visualized by immunohistochemistry. Oxygen supply maps were created using the normalized information from pimonidazole and hypoxia-related proteins. Results: Based on pimonidazole staining and other hypoxia.related proteins (osteopontin, hypoxia-inducible factor 1-alpha, and glucose transporter member 1) oxygen supply maps in prostate cancer were created. Overall, oxygen supply maps consisting of information from all hypoxia-related proteins showed high correlation and mutual information to the golden standard of pimonidazole. Here, we describe an improved computer-based ex vivo model for an accurate detection of oxygen supply in human prostate cancer tissue. Conclusions: This platform can be used for precise colocalization of novel candidate hypoxia-related proteins in a representative number of prostate cancer cases, and improve issues of single marker correlations. Furthermore, this study provides a source for further in situ tests and biochemical investigations PMID:26955501

  10. Satellite-based empirical models linking river plume dynamics with hypoxic area and volume

    NASA Astrophysics Data System (ADS)

    Le, Chengfeng; Lehrter, John C.; Hu, Chuanmin; Obenour, Daniel R.

    2016-03-01

    Satellite-based empirical models explaining hypoxic area and volume variation were developed for the seasonally hypoxic (O2 < 2 mg L-1) northern Gulf of Mexico adjacent to the Mississippi River. Annual variations in midsummer hypoxic area and volume were related to Moderate Resolution Imaging Spectroradiometer-derived monthly estimates of river plume area (km2) and average, inner shelf chlorophyll a concentration (Chl a, mg m-3). River plume area in June was negatively related with midsummer hypoxic area (km2) and volume (km3), while July inner shelf Chl a was positively related to hypoxic area and volume. Multiple regression models using river plume area and Chl a as independent variables accounted for most of the variability in hypoxic area (R2 = 0.92) or volume (R2 = 0.89). These models explain more variation in hypoxic area than models using Mississippi River nutrient loads as independent variables. The results here also support a hypothesis that confinement of the river plume to the inner shelf is an important mechanism controlling hypoxia area and volume in this region.

  11. Hydrogen sulfide mediates hypoxic vasoconstriction through a production of mitochondrial ROS in trout gills.

    PubMed

    Skovgaard, Nini; Olson, Kenneth R

    2012-09-01

    Hypoxic pulmonary vasoconstriction (HPV) is an adaptive response that diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to more well-ventilated parts. This response is important for the local matching of blood perfusion to ventilation and improves pulmonary gas exchange efficiency. HPV is an ancient and highly conserved response, expressed in the respiratory organs of all vertebrates, including lungs of mammals, birds, and reptiles; amphibian skin; and fish gills. The mechanism underlying HPV and how cells sense low Po(2) remains elusive. In perfused trout gills (Oncorhynchus mykiss), acute hypoxia, as well as H(2)S, caused an initial and transient constriction of the vasculature. Inhibition of the enzymes cystathionine-β-synthase and cystathionine-γ-lyase, which blocks H(2)S production, abolished the hypoxic response. Individually blocking the four complexes in the electron transport chain abolished both the hypoxic and the H(2)S-mediated constriction. Glutathione, an antioxidant and scavenger of superoxide, attenuated the vasoconstriction in response to hypoxia and H(2)S. Furthermore, diethyldithiocarbamate, an inhibitor of superoxide dismutase, attenuated the hypoxic and H(2)S constriction. This strongly suggests that H(2)S mediates the hypoxic vasoconstriction in trout gills. H(2)S may stimulate the mitochondrial production of superoxide, which is then converted to hydrogen peroxide (H(2)O(2)). Thus, H(2)O(2) may act as the "downstream" signaling molecule in hypoxic vasoconstriction. PMID:22739350

  12. Hypoxic stress-induced changes in ribosomes of maize seedling roots. [Zea mays L

    SciTech Connect

    Bailey-Serres, J.; Freeling, M. )

    1990-11-01

    The hypoxic stress response of Zea mays L. seedling roots involves regulation of gene expression at transcriptional and posttranscriptional levels. We investigated the effect of hypoxia on the translational machinery of seedling roots. The levels of monoribosomes and ribosomal subunits increased dramatically within 1 hour of stress. Prolonged hypoxia resulted in continued accumulation of nontranslating ribosomes, as well as increased levels of small polyribosomes. The return of seedlings to normal aerobic conditions resulted in recovery of normal polyribosome levels. Comparison of ribosomal proteins from control and hypoxic roots revealed differences in quantity and electrophoretic mobility. In vivo labeling of roots with ({sup 35}S)methionine revealed variations in newly synthesized ribosomal proteins. In vivo labeling of roots with ({sup 32}P)orthophosphate revealed a major reduction in the phosphorylation of a 31 kilodalton ribosomal protein in hypoxic stressed roots. In vitro phosphorylation of ribosomal proteins by endogenous kinases was used to probe for differences in ribosome structure and composition. The patterns of in vitro kinased phosphoproteins of ribosomes from control and hypoxic roots were not identical. Variation in phosphoproteins of polyribosomes from control and hypoxic roots, as well as among polyribosomes from hypoxic roots were observed. These results indicate that modification of the translational machinery occurs in response to hypoxic stress.

  13. A scenario and forecast model for Gulf of Mexico hypoxic area and volume

    USGS Publications Warehouse

    Scavia, Donald; Evans, Mary Anne; Obenour, Daniel R.

    2013-01-01

    For almost three decades, the relative size of the hypoxic region on the Louisiana-Texas continental shelf has drawn scientific and policy attention. During that time, both simple and complex models have been used to explore hypoxia dynamics and to provide management guidance relating the size of the hypoxic zone to key drivers. Throughout much of that development, analyses had to accommodate an apparent change in hypoxic sensitivity to loads and often cull observations due to anomalous meteorological conditions. Here, we describe an adaptation of our earlier, simple biophysical model, calibrated to revised hypoxic area estimates and new hypoxic volume estimates through Bayesian estimation. This application eliminates the need to cull observations and provides revised hypoxic extent estimates with uncertainties, corresponding to different nutrient loading reduction scenarios. We compare guidance from this model application, suggesting an approximately 62% nutrient loading reduction is required to reduce Gulf hypoxia to the Action Plan goal of 5,000 km2, to that of previous applications. In addition, we describe for the first time, the corresponding response of hypoxic volume. We also analyze model results to test for increasing system sensitivity to hypoxia formation, but find no strong evidence of such change.

  14. Development of an ultrasound sensitive oxygen carrier for oxygen delivery to hypoxic tissue.

    PubMed

    Eisenbrey, John R; Albala, Lorenzo; Kramer, Michael R; Daroshefski, Nick; Brown, David; Liu, Ji-Bin; Stanczak, Maria; O'Kane, Patrick; Forsberg, Flemming; Wheatley, Margaret A

    2015-01-15

    Radiation therapy is frequently used in the treatment of malignancies, but tumors are often more resistant than the surrounding normal tissue to radiation effects, because the tumor microenvironment is hypoxic. This manuscript details the fabrication and characterization of an ultrasound-sensitive, injectable oxygen microbubble platform (SE61O2) for overcoming tumor hypoxia. SE61O2 was fabricated by first sonicating a mixture of Span 60 and water-soluble vitamin E purged with perfluorocarbon gas. SE61O2 microbubbles were separated from the foam by flotation, then freeze dried under vacuum to remove all perfluorocarbon, and reconstituted with oxygen. Visually, SE61O2 microbubbles were smooth, spherical, with an average diameter of 3.1 μm and were reconstituted to a concentration of 6.5 E7 microbubbles/ml. Oxygen-filled SE61O2 provides 16.9 ± 1.0 dB of enhancement at a dose of 880 μl/l (5.7 E7 microbubbles/l) with a half-life under insonation of approximately 15 min. In in vitro release experiments, 2 ml of SE61O2 (1.3 E8 microbubbles) triggered with ultrasound was found to elevate oxygen partial pressures of 100ml of degassed saline 13.8 mmHg more than untriggered bubbles and 20.6 mmHg more than ultrasound triggered nitrogen-filled bubbles. In preliminary in vivo delivery experiments, triggered SE61O2 resulted in a 30.4 mmHg and 27.4 mmHg increase in oxygen partial pressures in two breast tumor mouse xenografts. PMID:25448552

  15. Hepatic transcriptomic and metabolic responses of hybrid striped bass to acute and chronic hypoxic insult

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Striped bass (Morone saxatilis), white bass (Morone chrysops), and their hybrid are an important group of recreational and farmed species in the United States. Regardless of habitat, it is not uncommon for fish of the genus Morone to encounter and cope with conditions of scarce oxygen availability....

  16. The effect of acute and chronic hypoxia on thoracic gas volume in anaesthetized rats.

    PubMed Central

    Barer, G R; Herget, J; Sloan, P J; Suggett, A J

    1978-01-01

    1. Thoracic gas volume at end expiration (functional residual capacity, FRC) was measured in chronically and acutely hypoxic anaesthetized rats by a plethysmograph method. 2. FRC, measured during air breathing, was 34-62% larger in rats which had been kept in an environmental chamber in 8, 10 or 12% O2 for 3 weeks than in littermate controls. FRC returned to normal after the rats had returned to air for 9 days. There was no constant difference in the pattern of breathing between control and chronically hypoxic rats. 3. Pressure-volume curves measured post mortem showed no difference in the volume of the lung at 25 cm H2O pressure or in the compliance of the lung between chronically hypoxic and control rats. Thus there was no gross mechanical change in the lung to account for the increase in FRC. 4. Acute hypoxia caused by breathing 12% O2 increased FRC in control but not in chronically hypoxic rats. The increase in FRC in control rats was abolished by combined blockade of the vagus nerves and carotid bodies (with procaine) but not by vagal blockade alone. 5. The combined vagal and carotid body blockade reduced FRC significantly in rats which had been in 10% O2 for 3 days but not in those which had been in 10% O2 for 21 days. 6. Lung area measured from radiographs was not reduced by a muscle relaxant in chronically hypoxic rats. Electromyograms from anterior intercostal muscles and the diaphragm showed no electrical activity in expiration in chronically hypoxic rats which might indicate an active muscular basis for their increased FRC. However when FRC was raised by acute hypoxia in control animals there was also no increase in electrical activity in expiration which could have explained their increase in lung volume. 7. We concluded that the increase in FRC during acute hypoxia in control rats was probably due to a reflex from the carotid body. The increase in FRC in chronically hypoxic rats, which was present while they breathed air, may have had an active

  17. A Molecular and Whole Body Insight of the Mechanisms Surrounding Glucose Disposal and Insulin Resistance with Hypoxic Treatment in Skeletal Muscle.

    PubMed

    Mackenzie, R W A; Watt, P

    2016-01-01

    Although the mechanisms are largely unidentified, the chronic or intermittent hypoxic patterns occurring with respiratory diseases, such as chronic pulmonary disease or obstructive sleep apnea (OSA) and obesity, are commonly associated with glucose intolerance. Indeed, hypoxia has been widely implicated in the development of insulin resistance either via the direct action on insulin receptor substrate (IRS) and protein kinase B (PKB/Akt) or indirectly through adipose tissue expansion and systemic inflammation. Yet hypoxia is also known to encourage glucose transport using insulin-dependent mechanisms, largely reliant on the metabolic master switch, 5' AMP-activated protein kinase (AMPK). In addition, hypoxic exposure has been shown to improve glucose control in type 2 diabetics. The literature surrounding hypoxia-induced changes to glycemic control appears to be confusing and conflicting. How is it that the same stress can seemingly cause insulin resistance while increasing glucose uptake? There is little doubt that acute hypoxia increases glucose metabolism in skeletal muscle and does so using the same pathway as muscle contraction. The purpose of this review paper is to provide an insight into the mechanisms underpinning the observed effects and to open up discussions around the conflicting data surrounding hypoxia and glucose control. PMID:27274997

  18. A Molecular and Whole Body Insight of the Mechanisms Surrounding Glucose Disposal and Insulin Resistance with Hypoxic Treatment in Skeletal Muscle

    PubMed Central

    Mackenzie, R. W. A.; Watt, P.

    2016-01-01

    Although the mechanisms are largely unidentified, the chronic or intermittent hypoxic patterns occurring with respiratory diseases, such as chronic pulmonary disease or obstructive sleep apnea (OSA) and obesity, are commonly associated with glucose intolerance. Indeed, hypoxia has been widely implicated in the development of insulin resistance either via the direct action on insulin receptor substrate (IRS) and protein kinase B (PKB/Akt) or indirectly through adipose tissue expansion and systemic inflammation. Yet hypoxia is also known to encourage glucose transport using insulin-dependent mechanisms, largely reliant on the metabolic master switch, 5′ AMP-activated protein kinase (AMPK). In addition, hypoxic exposure has been shown to improve glucose control in type 2 diabetics. The literature surrounding hypoxia-induced changes to glycemic control appears to be confusing and conflicting. How is it that the same stress can seemingly cause insulin resistance while increasing glucose uptake? There is little doubt that acute hypoxia increases glucose metabolism in skeletal muscle and does so using the same pathway as muscle contraction. The purpose of this review paper is to provide an insight into the mechanisms underpinning the observed effects and to open up discussions around the conflicting data surrounding hypoxia and glucose control. PMID:27274997

  19. Involvement of SIRT1 in hypoxic down-regulation of c-Myc and β-catenin and hypoxic preconditioning effect of polyphenols

    SciTech Connect

    Hong, Kyung-Soo; Park, Jun-Ik; Kim, Mi-Ju; Kim, Hak-Bong; Lee, Jae-Won; Dao, Trong Tuan; Oh, Won Keun; Kang, Chi-Dug; Kim, Sun-Hee

    2012-03-01

    SIRT1 has been found to function as a Class III deacetylase that affects the acetylation status of histones and other important cellular nonhistone proteins involved in various cellular pathways including stress responses and apoptosis. In this study, we investigated the role of SIRT1 signaling in the hypoxic down-regulations of c-Myc and β-catenin and hypoxic preconditioning effect of the red wine polyphenols such as piceatannol, myricetin, quercetin and resveratrol. We found that the expression of SIRT1 was significantly increased in hypoxia-exposed or hypoxic preconditioned HepG2 cells, which was closely associated with the up-regulation of HIF-1α and down-regulation of c-Myc and β-catenin expression via deacetylation of these proteins. In addition, blockade of SIRT1 activation using siRNA or amurensin G, a new potent SIRT1 inhibitor, abolished hypoxia-induced HIF-1α expression but increased c-Myc and β-catenin expression. SIRT1 was also found to stabilize HIF-1α protein and destabilize c-Myc, β-catenin and PHD2 under hypoxia. We also found that myricetin, quercetin, piceatannol and resveratrol up-regulated HIF-1α and down-regulated c-Myc, PHD2 and β-catenin expressions via SIRT1 activation, in a manner that mimics hypoxic preconditioning. This study provides new insights of the molecular mechanisms of hypoxic preconditioning and suggests that polyphenolic SIRT1 activators could be used to mimic hypoxic/ischemic preconditioning. -- Graphical abstract: Polyphenols mimicked hypoxic preconditioning by up-regulating HIF-1α and SIRT1 and down-regulating c-Myc, PHD2, and β-catenin. HepG2 cells were pretreated with the indicated doses of myricetin (MYR; A), quercetin (QUR; B), or piceatannol (PIC; C) for 4 h and then exposed to hypoxia for 4 h. Levels of HIF-1α, SIRT1, c-Myc, β-catenin, and PHD2 were determined by western blot analysis. The data are representative of three individual experiments. Highlights: ► SIRT1 expression is increased in hypoxia

  20. Autoradiographic study of tritium-labeled misonidazole in the mouse

    SciTech Connect

    Cobb, L.M.; Nolan, J.

    1989-04-01

    The localization of tritiated misonidazole metabolites in a number of normal tissues in the mouse is reported from autoradiography. The labeled misonidazole was injected at 750 or 75 mg/kg body weight (Rel. Sp. Act. 74 and 740 MBq/mg respectively). The grain count ratio, parenchyma:stroma, for selected tissues was: liver (centrilobular zone) 13; meibomian gland (acini) 68, (duct) 116; esophagus (keratinized layer) 61; enamel organ 17. It is concluded that there are a number of tissues which will accumulate MISO metabolites although they may not all be hypoxic.

  1. Fetal in vivo continuous cardiovascular function during chronic hypoxia.

    PubMed

    Allison, B J; Brain, K L; Niu, Y; Kane, A D; Herrera, E A; Thakor, A S; Botting, K J; Cross, C M; Itani, N; Skeffington, K L; Beck, C; Giussani, D A

    2016-03-01

    Although the fetal cardiovascular defence to acute hypoxia and the physiology underlying it have been established for decades, how the fetal cardiovascular system responds to chronic hypoxia has been comparatively understudied. We designed and created isobaric hypoxic chambers able to maintain pregnant sheep for prolonged periods of gestation under controlled significant (10% O2) hypoxia, yielding fetal mean P(aO2) levels (11.5 ± 0.6 mmHg) similar to those measured in human fetuses of hypoxic pregnancy. We also created a wireless data acquisition system able to record fetal blood flow signals in addition to fetal blood pressure and heart rate from free moving ewes as the hypoxic pregnancy is developing. We determined in vivo longitudinal changes in fetal cardiovascular function including parallel measurement of fetal carotid and femoral blood flow and oxygen and glucose delivery during the last third of gestation. The ratio of oxygen (from 2.7 ± 0.2 to 3.8 ± 0.8; P < 0.05) and of glucose (from 2.3 ± 0.1 to 3.3 ± 0.6; P < 0.05) delivery to the fetal carotid, relative to the fetal femoral circulation, increased during and shortly after the period of chronic hypoxia. In contrast, oxygen and glucose delivery remained unchanged from baseline in normoxic fetuses. Fetal plasma urate concentration increased significantly during chronic hypoxia but not during normoxia (Δ: 4.8 ± 1.6 vs. 0.5 ± 1.4 μmol l(-1), P<0.05). The data support the hypotheses tested and show persisting redistribution of substrate delivery away from peripheral and towards essential circulations in the chronically hypoxic fetus, associated with increases in xanthine oxidase-derived reactive oxygen species. PMID:26926316

  2. Induction of controlled hypoxic pregnancy in large mammalian species.

    PubMed

    Brain, Kirsty L; Allison, Beth J; Niu, Youguo; Cross, Christine M; Itani, Nozomi; Kane, Andrew D; Herrera, Emilio A; Giussani, Dino A

    2015-12-01

    Progress in the study of pregnancy complicated by chronic hypoxia in large mammals has been held back by the inability to measure long-term significant reductions in fetal oxygenation at values similar to those measured in human pregnancy complicated by fetal growth restriction. Here, we introduce a technique for physiological research able to maintain chronically instrumented maternal and fetal sheep for prolonged periods of gestation under significant and controlled isolated chronic hypoxia beyond levels that can be achieved by habitable high altitude. This model of chronic hypoxia permits measurement of materno-fetal blood gases as the challenge is actually occurring. Chronic hypoxia of this magnitude and duration using this model recapitulates the significant asymmetric growth restriction, the pronounced cardiomyopathy, and the loss of endothelial function measured in offspring of high-risk pregnancy in humans, opening a new window of therapeutic research. PMID:26660546

  3. Scalloped hammerhead shark Sphyrna lewini, utilizes deep-water, hypoxic zone in the Gulf of California.

    PubMed

    Jorgensen, S J; Klimley, A P; Muhlia-Melo, A F

    2009-05-01

    A hammerhead shark Sphyrna lewini tracked for 74 days revealed an expansion of the range of vertical distribution for the species to include the extreme hypoxic environment of the oxygen minimum layer in the Gulf of California. PMID:20735666

  4. Novel Genes Critical for Hypoxic Preconditioning in Zebrafish Are Regulators of Insulin and Glucose Metabolism

    PubMed Central

    Manchenkov, Tania; Pasillas, Martina P.; Haddad, Gabriel G.; Imam, Farhad B.

    2015-01-01

    Severe hypoxia is a common cause of major brain, heart, and kidney injury in adults, children, and newborns. However, mild hypoxia can be protective against later, more severe hypoxia exposure via “hypoxic preconditioning,” a phenomenon that is not yet fully understood. Accordingly, we have established and optimized an embryonic zebrafish model to study hypoxic preconditioning. Using a functional genomic approach, we used this zebrafish model to identify and validate five novel hypoxia-protective genes, including irs2, crtc3, and camk2g2, which have been previously implicated in metabolic regulation. These results extend our understanding of the mechanisms of hypoxic preconditioning and affirm the discovery potential of this novel vertebrate hypoxic stress model. PMID:25840431

  5. Nitrite Regulates Hypoxic Vasodilation via Myoglobin–Dependent Nitric Oxide Generation

    PubMed Central

    Totzeck, Matthias; Hendgen-Cotta, Ulrike B.; Luedike, Peter; Berenbrink, Michael; Klare, Johann P.; Steinhoff, Heinz-Juergen; Semmler, Dominik; Shiva, Sruti; Williams, Daryl; Kipar, Anja; Gladwin, Mark T.; Schrader, Juergen; Kelm, Malte; Cossins, Andrew R.; Rassaf, Tienush

    2012-01-01

    Background Hypoxic vasodilation is a physiological response to low oxygen (O2) tension that increases blood supply to match metabolic demands. While this response has been characterized for more than 100 years, the underlying hypoxic sensing and effector signaling mechanisms remain uncertain. We have shown that deoxygenated myoglobin (deoxyMb) in the heart can reduce nitrite to nitric oxide (NO˙) and thereby contribute to cardiomyocyte NO˙ signaling during ischemia. Based on recent observations that Mb is expressed in the vasculature of hypoxia-tolerant fish, we hypothesized that endogenous nitrite may contribute to physiological hypoxic vasodilation via reactions with vascular Mb to form NO˙. Methods and Results We here show that Mb is expressed in vascular smooth muscle and contributes significantly to nitrite-dependent hypoxic vasodilation in vivo and ex vivo. The generation of NO˙ from nitrite reduction by deoxyMb activates canonical soluble guanylate cyclase (sGC)/cyclic guanosine monophosphate (cGMP) signaling pathways. In vivo and ex vivo vasodilation responses, the reduction of nitrite to NO˙ and the subsequent signal transduction mechanisms were all significantly impaired in mice without myoglobin (Mb−/−). Hypoxic vasodilation studies in Mb, endothelial and inducible NO synthase knockout models (eNOS−/−, iNOS−/−) suggest that only Mb contributes to systemic hypoxic vasodilatory responses in mice. Conclusions Endogenous nitrite is a physiological effector of hypoxic vasodilation. Its reduction to NO˙ via the heme globin Mb enhances blood flow and matches O2 supply to increased metabolic demands under hypoxic conditions. PMID:22685116

  6. Some factors affecting the specific toxicity of misonidazole towards hypoxic mammalian cells.

    PubMed Central

    Stratford, I. J.; Gray, P.

    1978-01-01

    The toxic action of misonidazole towards hypoxic mammalian cells has been shown to be a function of serum concentration, with higher serum concentrations enhancing the toxic effect. Added thiols protect cells against misonidazole toxicity. In addition, the action of misonidazole on hypoxic cells labelled with 5-BUdR has been examined. Cells with incroported 5-BUdR are no more sensitive to misonidazole toxicity than are cells without label. PMID:277212

  7. Hemoglobin Effects on Nitric Oxide Mediated Hypoxic Vasodilation.

    PubMed

    Rong, Zimei; Cooper, Chris E

    2016-01-01

    The brain responds to hypoxia with an increase in cerebral blood flow (CBF). However, such an increase is generally believed to start only after the oxygen tension decreases to a certain threshold level. Although many mechanisms (different vasodilator and different generation and metabolism mechanisms of the vasodilator) have been proposed at the molecular level, none of them has gained universal acceptance. Nitric oxide (NO) has been proposed to play a central role in the regulation of oxygen supply since it is a vasodilator whose production and metabolism are both oxygen dependent. We have used a computational model that simulates blood flow and oxygen metabolism in the brain (BRAINSIGNALS) to test mechanism by which NO may elucidate hypoxic vasodilation. The first model proposed that NO was produced by the enzyme nitric oxide synthase (NOS) and metabolized by the mitochondrial enzyme cytochrome c oxidase (CCO). NO production declined with decreasing oxygen concentration given that oxygen is a substrate for nitric oxide synthase (NOS). However, this was balanced by NO metabolism by CCO, which also declined with decreasing oxygen concentration. However, the NOS effect was dominant; the resulting model profiles of hypoxic vasodilation only approximated the experimental curves when an unfeasibly low K m for oxygen for NOS was input into the model. We therefore modified the model such that NO generation was via the nitrite reductase activity of deoxyhemoglobin instead of NOS, whilst keeping the metabolism of NO by CCO the same. NO production increased with decreasing oxygen concentration, leading to an improved reproduction of the experimental CBF versus PaO2 curve. However, the threshold phenomenon was not perfectly reproduced. In this present work, we incorporated a wider variety of oxygen dependent and independent NO production and removal mechanisms. We found that the addition of NO removal via oxidation to nitrate mediated by oxyhemoglobin resulted in the

  8. Hypoxic preconditioning: effect, mechanism and clinical implication (Part 1).

    PubMed

    Lu, Guo-wei; Shao, Guo

    2014-11-01

    Hypoxic preconditioning (HPC) refers to exposure of organisms, systems, organs, tissues or cells to moderate hypoxia/ischemia that is able to result in a resistance to subsequent severe hypoxia/ischemia in tissues and cells. The effects exerted by HPC are well documented. The original local in situ (LiHPC) is now broadened to remote ectopic organs-tissues (ReHPC) and extended crossly to cross pluripotential HPC(CpHPC) induced by a variety of stresses other than hypoxia/ischemia, including cancer, for example. We developed a unique animal model of repetitive autohypoxia in adult mice, and studied systematically on the effects and mechanisms of HPC on the model in our laboratory since the early 1960s. The tolerances to hypoxia and protection from injury increased significantly in this model. The adult mice behave like hypoxia-intolerant mammalian newborns and hypoxia-tolerant adult animals during their exposure to repetitive autohypoxia. The overall energy supply and demand decreased, the microorganization of the brain maintained and the spacial learning and memory ability improved but not impaired, the detrimental neurochemicals such as free radicals down-regulated and the beneficial neurochemicals such as adenosine(ADO) and antihypoxic gene(s)/factor(s) (AHGs/AHFs) up-regulated. Accordingly, we hypothesize that mechanisms for the tolerance/protective effects of HPC are fundamentally depending on energy saving and brain plasticity in particular. It is thought that these two major mechanisms are triggered by exposure to hypoxia/ischemia via oxygen sensing-transduction pathways and HIF-1 initiation cascades. We suggest that HPC is an intrinsic mechanism developed in biological evolution and is a novel potential strategy for fighting against hypoxia-ischemia and other stresses. Motivation of endogenous antihypoxic potential, activation of oxygen sensing--signal transduction systems and supplement of exogenous antihypoxic substances as well as development of HPC

  9. A new HCV mouse model on the block.

    PubMed

    Tawar, Rajiv G; Mailly, Laurent; Baumert, Thomas F

    2014-10-01

    The investigation of virus-induced liver disease and hepatocellular carcinoma needs small animal models modeling hepatitis C virus (HCV) infection and liver disease biology. A recent study published in Cell Research reports a novel mouse model which is permissive for chronic HCV infection and shows chronic liver injury including inflammation, steatosis and fibrosis. PMID:25257465

  10. Screening and identification of a specific peptide for targeting hypoxic hepatoma cells.

    PubMed

    Liu, Yiming; Xia, Xiangwen; Wang, Yong; Li, Xin; Zhou, Guofeng; Liang, Huiming; Feng, Gansheng; Zheng, Chuansheng

    2016-08-01

    The biological behaviors of residual hepatoma cells after transarterial embolization therapy, which exist in a hypoxic or even anaerobic tumor microenvironment, differ from the tumor cells under normoxic conditions. This study aimed to use a phage display peptide library for in vivo and in vitro screening to obtain a peptide which could specifically bind to hypoxic hepatoma cells, allowing further targeted diagnosis and treatment for liver cancer. In this study, hypoxic hepatoma cells HepG2 (targeted cells), and normal liver cells HL-7702 (control cells), were utilized to perform three rounds of in vitro screening using a phage-displayed 7-mer peptide library. In addition, hypoxic HepG2 were subcutaneously injected into nude mice to establish a hepatocarcinoma model, followed by performing three rounds of in vivo screening on the phages identified from the in vitro screening. The products from the screening were further identified using ELISA and immunofluorescence staining on cells and tissues. The results indicated that the P11 positive clone had the highest binding effect with hypoxic hepatoma cells. The sequence of the exogenous insert fragment of P11 positive clone was obtained by sequencing: GSTSFSK. The binding assay indicated that GSTSFSK could specifically bind to hypoxic hepatoma cells and hepatocarcinoma tissues. This 7-mer peptide has the potential to be developed as an useful molecular to the targeting diagnosis and treatment of residual hepatoma cells after transarterial chemoembolization. PMID:27381416

  11. Mouse Models of Rheumatoid Arthritis.

    PubMed

    Caplazi, P; Baca, M; Barck, K; Carano, R A D; DeVoss, J; Lee, W P; Bolon, B; Diehl, L

    2015-09-01

    Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disorder characterized by synovitis that leads to cartilage and bone erosion by invading fibrovascular tissue. Mouse models of RA recapitulate many features of the human disease. Despite the availability of medicines that are highly effective in many patient populations, autoimmune diseases (including RA) remain an area of active biomedical research, and consequently mouse models of RA are still extensively used for mechanistic studies and validation of therapeutic targets. This review aims to integrate morphologic features with model biology and cover the key characteristics of the most commonly used induced and spontaneous mouse models of RA. Induced models emphasized in this review include collagen-induced arthritis and antibody-induced arthritis. Collagen-induced arthritis is an example of an active immunization strategy, whereas antibody- induced arthritis models, such as collagen antibody-induced arthritis and K/BxN antibody transfer arthritis, represent examples of passive immunization strategies. The coverage of spontaneous models in this review is focused on the TNFΔ (ARE) mouse, in which arthritis results from overexpression of TNF-α, a master proinflammatory cytokine that drives disease in many patients. PMID:26063174

  12. Astragalus on the anti-fatigue effect in hypoxic mice

    PubMed Central

    Zhang, Gang; Zhou, Si-Min; Zheng, Shan-Jun; Liu, Fu-Yu; Gao, Yu-Qi

    2015-01-01

    Objective: Astragalus is a traditional Chinese medicine to improve the function of the body. The purpose of this study is to investigate the effect of astragalus on improvement of anti-fatigue capacity in mice under simulated plateau environment. Methods: Male Kunming mice were randomly divided into the following groups: the control group, astragalus treatment groups in low dosage (LD) (1.0 g/kg·d), mid dosage (MD) (3.0 g/kg·d), and high dosage (HD) (30 g/kg·d). The control group were fed under normoxia environment, and hypoxic mice were fed at a stimulated elevation of 5000 meters. After continuous intragastric administration for 10 days, exhaustive swimming experiment was conducted in the anoxic environment. The swimming time, glucose and lactic acid concentration in blood, glycogen contents in liver, SOD and MDA were determined. Results: Compared with the control group, the swimming time of each astragalus treated group was evidently prolonged (P < 0.05), and the area under the blood lactic acid curve was significantly decreased (P < 0.05). In the high and middle dose of astragalus group, liver glycogen was obviously increased. After exhausted swimming, glycogen contents in blood and SOD were significantly increased, while MDA was evidently reduced (P < 0.05). Conclusion: Astragalus can alleviate physical fatigue in mice under simulated plateau environment. It has an obvious anti-fatigue effect and it’s worthy of further study. PMID:26550363

  13. Stem Cell Therapy for Neonatal Hypoxic-Ischemic Encephalopathy

    PubMed Central

    Gonzales-Portillo, Gabriel S.; Reyes, Stephanny; Aguirre, Daniela; Pabon, Mibel M.; Borlongan, Cesar V.

    2014-01-01

    Treatments for neonatal hypoxic-ischemic encephalopathy (HIE) have been limited. The aim of this paper is to offer translational research guidance on stem cell therapy for neonatal HIE by examining clinically relevant animal models, practical stem cell sources, safety and efficacy of endpoint assays, as well as a general understanding of modes of action of this cellular therapy. In order to do so, we discuss the clinical manifestations of HIE, highlighting its overlapping pathologies with stroke and providing insights on the potential of cell therapy currently investigated in stroke, for HIE. To this end, we draw guidance from recommendations outlined in stem cell therapeutics as an emerging paradigm for stroke or STEPS, which have been recently modified to Baby STEPS to cater for the “neonatal” symptoms of HIE. These guidelines recognized that neonatal HIE exhibit distinct disease symptoms from adult stroke in need of an innovative translational approach that facilitates the entry of cell therapy in the clinic. Finally, new information about recent clinical trials and insights into combination therapy are provided with the vision that stem cell therapy may benefit from available treatments, such as hypothermia, already being tested in children diagnosed with HIE. PMID:25161645

  14. Hypoxic regulation of the noncoding genome and NEAT1.

    PubMed

    Choudhry, Hani; Mole, David R

    2016-05-01

    Activation of hypoxia pathways is both associated with and contributes to an aggressive phenotype across multiple types of solid cancers. The regulation of gene transcription by hypoxia-inducible factor (HIF) is a key element in this response. HIF directly upregulates the expression of many hundreds of protein-coding genes, which act to both improve oxygen delivery and to reduce oxygen demand. However, it is now becoming apparent that many classes of noncoding RNAs are also regulated by hypoxia, with several (e.g. micro RNAs, long noncoding RNAs and antisense RNAs) under direct transcriptional regulation by HIF. These hypoxia-regulated, noncoding RNAs may act as effectors of the indirect response to HIF by acting on specific coding transcripts or by affecting generic RNA-processing pathways. In addition, noncoding RNAs may also act as modulators of the HIF pathway, either by integrating other physiological responses or, in the case of HIF-regulated, noncoding RNAs, by providing negative or positive feedback and feedforward loops that affect upstream or downstream components of the HIF cascade. These hypoxia-regulated, noncoding transcripts play important roles in the aggressive hypoxic phenotype observed in cancer. PMID:26590207

  15. North Pacific deglacial hypoxic events linked to abrupt ocean warming.

    PubMed

    Praetorius, S K; Mix, A C; Walczak, M H; Wolhowe, M D; Addison, J A; Prahl, F G

    2015-11-19

    Marine sediments from the North Pacific document two episodes of expansion and strengthening of the subsurface oxygen minimum zone (OMZ) accompanied by seafloor hypoxia during the last deglacial transition. The mechanisms driving this hypoxia remain under debate. We present a new high-resolution alkenone palaeotemperature reconstruction from the Gulf of Alaska that reveals two abrupt warming events of 4-5 degrees Celsius at the onset of the Bølling and Holocene intervals that coincide with sudden shifts to hypoxia at intermediate depths. The presence of diatomaceous laminations and hypoxia-tolerant benthic foraminiferal species, peaks in redox-sensitive trace metals, and enhanced (15)N/(14)N ratio of organic matter, collectively suggest association with high export production. A decrease in (18)O/(16)O values of benthic foraminifera accompanying the most severe deoxygenation event indicates subsurface warming of up to about 2 degrees Celsius. We infer that abrupt warming triggered expansion of the North Pacific OMZ through reduced oxygen solubility and increased marine productivity via physiological effects; following initiation of hypoxia, remobilization of iron from hypoxic sediments could have provided a positive feedback on ocean deoxygenation through increased nutrient utilization and carbon export. Such a biogeochemical amplification process implies high sensitivity of OMZ expansion to warming. PMID:26581293

  16. Experimental models of perinatal hypoxic-ischemic brain damage.

    PubMed

    Vannucci, R C

    1993-01-01

    Animal research has provided important information on the pathogenesis of and neuropathologic responses to perinatal cerebral hypoxia-ischemia. In experimental animals, structural brain damage from hypoxia-ischemia has been produced in immature rats, rabbits, guinea pigs, sheep and monkeys (18, 20, 24, 25, 38). Of the several available animal models, the fetal and newborn rhesus monkey and immature rat have been studied most extensively because of their similarities to humans in respect to the physiology of reproduction and their neuroanatomy at or shortly following birth. Given the frequency of occurrence of human perinatal hypoxic-ischemic brain damage and the multiple, often severe neurologic handicaps which ensue in infants and children, it is not surprising that the above described animal models have been developed. These models have provided the basis for investigations to clarify not only physiologic and biochemical mechanisms of tissue injury but also the efficacy of specific management strategies. Hopefully, such animal research will continue to provide important information regarding how best to prevent or minimize the devastating consequences of perinatal cerebral hypoxia-ischemia. PMID:8311995

  17. Concepts of hypoxic NO signaling in remote ischemic preconditioning

    PubMed Central

    Totzeck, Matthias; Hendgen-Cotta, Ulrike; Rassaf, Tienush

    2015-01-01

    Acute coronary syndromes remain a leading single cause of death worldwide. Therapeutic strategies to treat cardiomyocyte threatening ischemia/reperfusion injury are urgently needed. Remote ischemic preconditioning (rIPC) applied by brief ischemic episodes to heart-distant organs has been tested in several clinical studies, and the major body of evidence points to beneficial effects of rIPC for patients. The underlying signaling, however, remains incompletely understood. This relates particularly to the mechanism by which the protective signal is transferred from the remote site to the target organ. Many pathways have been forwarded but none can explain the protective effects completely. In light of recent experimental studies, we here outline the current knowledge relating to the generation of the protective signal in the remote organ, the signal transfer to the target organ and the transduction of the transferred signal into cardioprotection. The majority of studies favors a humoral factor that activates cardiomyocyte downstream signaling - receptor-dependent and independently. Cellular targets include deleterious calcium (Ca2+) signaling, reactive oxygen species, mitochondrial function and structure, and cellular apoptosis and necrosis. Following an outline of the existing evidence, we will furthermore characterize the existing knowledge and discuss future perspectives with particular emphasis on the interaction between the recently discovered hypoxic nitrite-nitric oxide signaling in rIPC. This refers to the protective role of nitrite, which can be activated endogenously using rIPC and which then contributes to cardioprotection by rIPC. PMID:26516418

  18. Diving bradycardia: a mechanism of defence against hypoxic damage.

    PubMed

    Alboni, Paolo; Alboni, Marco; Gianfranchi, Lorella

    2011-06-01

    A feature of all air-breathing vertebrates, diving bradycardia is triggered by apnoea and accentuated by immersion of the face or whole body in cold water. Very little is known about the afferents of diving bradycardia, whereas the efferent part of the reflex circuit is constituted by the cardiac vagal fibres. Diving bradycardia is associated with vasoconstriction of selected vascular beds and a reduction in cardiac output. The diving response appears to be more pronounced in mammals than in birds. In humans, the bradycardic response to diving varies greatly from person to person; the reduction in heart rate generally ranges from 15 to 40%, but a small proportion of healthy individuals can develop bradycardia below 20 beats/min. During prolonged dives, bradycardia becomes more pronounced because of activation of the peripheral chemoreceptors by a reduction in the arterial partial pressure of oxygen (O2), responsible for slowing of heart rate. The vasoconstriction is associated with a redistribution of the blood flow, which saves O2 for the O2-sensitive organs, such as the heart and brain. The results of several investigations carried out both in animals and in humans show that the diving response has an O2-conserving effect, both during exercise and at rest, thus lengthening the time to the onset of serious hypoxic damage. The diving response can therefore be regarded as an important defence mechanism for the organism. PMID:21330930

  19. Nitrite as regulator of hypoxic signaling in mammalian physiology

    PubMed Central

    van Faassen, Ernst E.; Bahrami, Soheyl; Feelisch, Martin; Hogg, Neil; Kelm, Malte; Kim-Shapiro, Daniel B.; Kozlov, Andrey V.; Li, Haitao; Lundberg, Jon O.; Mason, Ron; Nohl, Hans; Rassaf, Tienush; Samouilov, Alexandre; Slama-Schwok, Anny; Shiva, Sruti; Vanin, Anatoly F.; Weitzberg, Eddie; Zweier, Jay; Gladwin, Mark T.

    2009-01-01

    In this review we consider the physiological effects of endogenous and pharmacological levels of nitrite under conditions of hypoxia. In humans, the nitrite anion has long been considered as metastable intermediate in the oxidation of nitric oxide radicals to the stable metabolite nitrate. This oxidation cascade was thought to be irreversible under physiological conditions. However, a growing body of experimental observations attests that the presence of endogenous nitrite regulates a number of signaling events along the physiological and pathophysiological oxygen gradient. Hypoxic signaling events include vasodilation, modulation of mitochondrial respiration, and cytoprotection following ischemic insult. These phenomena are attributed to the reduction of nitrite anions to nitric oxide if local oxygen levels in tissues decrease. Recent research identified a growing list of enzymatic and non-enzymatic pathways for this endogenous reduction of nitrite. Additional direct signaling events not involving free nitric oxide are proposed. We here discuss the mechanisms and properties of these various pathways and the role played by the local concentration of free oxygen in the affected tissue. PMID:19219851

  20. Kill-painting of hypoxic tumours in charged particle therapy

    PubMed Central

    Tinganelli, Walter; Durante, Marco; Hirayama, Ryoichi; Krämer, Michael; Maier, Andreas; Kraft-Weyrather, Wilma; Furusawa, Yoshiya; Friedrich, Thomas; Scifoni, Emanuele

    2015-01-01

    Solid tumours often present regions with severe oxygen deprivation (hypoxia), which are resistant to both chemotherapy and radiotherapy. Increased radiosensitivity as a function of the oxygen concentration is well described for X-rays. It has also been demonstrated that radioresistance in anoxia is reduced using high-LET radiation rather than conventional X-rays. However, the dependence of the oxygen enhancement ratio (OER) on radiation quality in the regions of intermediate oxygen concentrations, those normally found in tumours, had never been measured and biophysical models were based on extrapolations. Here we present a complete survival dataset of mammalian cells exposed to different ions in oxygen concentration ranging from normoxia (21%) to anoxia (0%). The data were used to generate a model of the dependence of the OER on oxygen concentration and particle energy. The model was implemented in the ion beam treatment planning system to prescribe uniform cell killing across volumes with heterogeneous radiosensitivity. The adaptive treatment plans have been validated in two different accelerator facilities, using a biological phantom where cells can be irradiated simultaneously at three different oxygen concentrations. We thus realized a hypoxia-adapted treatment plan, which will be used for painting by voxel of hypoxic tumours visualized by functional imaging. PMID:26596243

  1. Hypoxic regulation of the noncoding genome and NEAT1

    PubMed Central

    Choudhry, Hani

    2016-01-01

    Activation of hypoxia pathways is both associated with and contributes to an aggressive phenotype across multiple types of solid cancers. The regulation of gene transcription by hypoxia-inducible factor (HIF) is a key element in this response. HIF directly upregulates the expression of many hundreds of protein-coding genes, which act to both improve oxygen delivery and to reduce oxygen demand. However, it is now becoming apparent that many classes of noncoding RNAs are also regulated by hypoxia, with several (e.g. micro RNAs, long noncoding RNAs and antisense RNAs) under direct transcriptional regulation by HIF. These hypoxia-regulated, noncoding RNAs may act as effectors of the indirect response to HIF by acting on specific coding transcripts or by affecting generic RNA-processing pathways. In addition, noncoding RNAs may also act as modulators of the HIF pathway, either by integrating other physiological responses or, in the case of HIF-regulated, noncoding RNAs, by providing negative or positive feedback and feedforward loops that affect upstream or downstream components of the HIF cascade. These hypoxia-regulated, noncoding transcripts play important roles in the aggressive hypoxic phenotype observed in cancer. PMID:26590207

  2. Chronic cholecystitis

    MedlinePlus

    Cholecystitis - chronic ... Most of the time, chronic cholecystitis is caused by repeated attacks of acute (sudden) cholecystitis. Most of these attacks are caused by gallstones in the gallbladder. These ...

  3. Chronic Bronchitis

    MedlinePlus

    Bronchitis is an inflammation of the bronchial tubes, the airways that carry air to your lungs. It ... chest tightness. There are two main types of bronchitis: acute and chronic. Chronic bronchitis is one type ...

  4. Selective Intracellular Delivery of Recombinant Arginine Deiminase (ADI) Using pH-Sensitive Cell Penetrating Peptides To Overcome ADI Resistance in Hypoxic Breast Cancer Cells.

    PubMed

    Yeh, Tzyy-Harn; Chen, Yun-Ru; Chen, Szu-Ying; Shen, Wei-Chiang; Ann, David K; Zaro, Jennica L; Shen, Li-Jiuan

    2016-01-01

    Arginine depletion strategies, such as pegylated recombinant arginine deiminase (ADI-PEG20), offer a promising anticancer treatment. Many tumor cells have suppressed expression of a key enzyme, argininosuccinate synthetase 1 (ASS1), which converts citrulline to arginine. These tumor cells become arginine auxotrophic, as they can no longer synthesize endogenous arginine intracellularly from citrulline, and are therefore sensitive to arginine depletion therapy. However, since ADI-PEG20 only depletes extracellular arginine due to low internalization, ASS1-expressing cells are not susceptible to treatment since they can synthesize arginine