bluuebunny/crossref_metadata_2025 huggingface dataset:
The bone morphogenic protein inhibitor, noggin, reduces glycemia and vascular inflammation in db/db mice
Authors: Koga Mitsuhisa , Engberding Niels , Dikalova Anna E. , Chang Kyung Hwa , Seidel-Rogol Bonnie , Long James S. , Lassègue Bernard , Jo Hanjoong , Griendling Kathy K.
Published: June 2013

Vascular diseases frequently accompany diabetes mellitus. Based on the current understanding of atherosclerosis as an inflammatory disorder of the vascular wall, it has been speculated that diabetes may accelerate atherosclerosis by inducing a proinflammatory milieu in the vasculature. ANG II and bone morphogenic proteins (BMPs) have been implicated in vascular inflammation. We evaluated the effect of angiotensin receptor blockade by valsartan and BMP inhibition by noggin on markers of vascular inflammation in a mouse model of diabetes. Noggin had no effect on blood pressure but decreased serum glucose levels, whereas valsartan significantly decreased blood pressure, but not serum glucose. Both inhibitors reduced reactive oxygen species production in the aorta. Additionally, noggin and valsartan diminish gene transcription and protein expression of various inflammatory molecules in the vascular wall. These observations indicate that although both inhibitors block superoxide production and have similar effects on inflammatory gene expression, glycemia and blood pressure may represent a secondary target differentially affected by noggin and valsartan. Our data clearly identify the BMP pathway as a potentially potent therapeutic target in diabetic inflammatory vascular disease.
The Fas/FasL pathway impairs the alveolar fluid clearance in mouse lungs
Authors: Herrero Raquel , Tanino Mishie , Smith Lincoln S. , Kajikawa Osamu , Wong Venus A. , Mongovin Steve , Matute-Bello Gustavo , Martin Thomas R.
Published: June 2013

Alveolar epithelial damage is a critical event that leads to protein-rich edema in acute lung injury (ALI), but the mechanisms leading to epithelial damage are not completely understood. Cell death by necrosis and apoptosis occurs in alveolar epithelial cells in the lungs of patients with ALI. Fas activation induces apoptosis of alveolar epithelial cells, but its role in the formation of lung edema is unclear. The main goal of this study was to determine whether activation of the Fas/Fas ligand pathway in the lungs could alter the function of the lung epithelium, and the mechanisms involved. The results show that Fas activation alters the alveolar barrier integrity and impairs the ability of the lung alveolar epithelium to reabsorb fluid from the air spaces. This result was dependent on the presence of a normal Fas receptor and was not affected by inflammation induced by Fas activation. Alteration of the fluid transport properties of the alveolar epithelium was partially restored by β-adrenergic stimulation. Fas activation also caused apoptosis of alveolar endothelial cells, but this effect was less pronounced than the effect on the alveolar epithelium. Thus, activation of the Fas pathway impairs alveolar epithelial function in mouse lungs by mechanisms involving caspase-dependent apoptosis, suggesting that targeting apoptotic pathways could reduce the formation of lung edema in ALI.
Agonists of MAS oncogene and angiotensin II type 2 receptors attenuate cardiopulmonary disease in rats with neonatal hyperoxia-induced lung injury
Authors: Wagenaar Gerry T. M. , Laghmani El Houari , Fidder Melissa , Sengers Rozemarijn M. A. , de Visser Yvonne P. , de Vries Louwe , Rink Rick , Roks Anton J. M. , Folkerts Gert , Walther Frans J.
Published: June 2013

Stimulation of MAS oncogene receptor (MAS) or angiotensin (Ang) receptor type 2 (AT2) may be novel therapeutic options for neonatal chronic lung disease (CLD) by counterbalancing the adverse effects of the potent vasoconstrictor angiotensin II, consisting of arterial hypertension (PAH)-induced right ventricular hypertrophy (RVH) and pulmonary inflammation. We determined the cardiopulmonary effects in neonatal rats with CLD of daily treatment during continuous exposure to 100% oxygen for 10 days with specific ligands for MAS [cyclic Ang-(1-7); 10–50 μg·kg−1·day−1] and AT2 [dKcAng-(1-7); 5–20 μg·kg−1·day−1]. Parameters investigated included lung and heart histopathology, fibrin deposition, vascular leakage, and differential mRNA expression in the lungs of key genes involved in the renin-angiotensin system, inflammation, coagulation, and alveolar development. We investigated the role of nitric oxide synthase inhibition with Nω-nitro-l-arginine methyl ester (25 mg·kg−1·day−1) during AT2 agonist treatment. Prophylactic treatment with agonists for MAS or AT2 for 10 days diminished cardiopulmonary injury by reducing alveolar septum thickness and medial wall thickness of small arterioles and preventing RVH. Both agonists attenuated the pulmonary influx of inflammatory cells, including macrophages (via AT2) and neutrophils (via MAS) but did not reduce alveolar enlargement and vascular alveolar leakage. The AT2 agonist attenuated hyperoxia-induced fibrin deposition. In conclusion, stimulation of MAS or AT2 attenuates cardiopulmonary injury by reducing pulmonary inflammation and preventing PAH-induced RVH but does not affect alveolar and vascular development in neonatal rats with experimental CLD. The beneficial effects of AT2 activation on experimental CLD were mediated via a NOS-independent mechanism.
Wt1-expressing progenitors contribute to multiple tissues in the developing lung
Authors: Cano Elena , Carmona Rita , Muñoz-Chápuli Ramón
Published: June 2013

Lungs develop from paired endodermal outgrowths surrounded by a mesodermal mesenchyme. Part of this mesenchyme arises from epithelial-mesenchymal transition of the mesothelium that lines the pulmonary buds. Previous studies have shown that this mesothelium-derived mesenchyme contributes to the smooth muscle of the pulmonary vessels, but its significance for lung morphogenesis and its developmental fate are still little known. We have studied this issue using the transgenic mouse model mWt1/IRES/GFP-Cre (Wt1cre) crossed with the Rosa26R-EYFP reporter mouse. In the developing lungs, Wt1, the Wilms' tumor suppressor gene, is specifically expressed in the embryonic mesothelium. In the embryos obtained from the crossbreeding, the Wt1-expressing cell lineage produces the yellow fluorescent protein (YFP), allowing for colocalization with differentiation markers. Wt1cre-YFP cells were very abundant from the origin of the lung buds to postnatal stages, contributing significantly to pulmonary endothelial and smooth muscle cells, bronchial musculature, tracheal and bronchial cartilage, as well as CD34+fibroblast-like interstitial cells. Thus Wt1cre-YFP mesenchymal cells show the very same differentiation potential as the splanchnopleural mesenchyme surrounding the lung buds. FSP1+fibroblast-like cells were always YFP−; they expressed the common leukocyte antigen CD45 and were apparently recruited from circulating progenitors. We have also found defects in pulmonary development in Wt1−/−embryos, which showed abnormally fused lung lobes, round-shaped and reduced pleural cavities, and diaphragmatic hernia. Our results suggest a novel role for the embryonic mesothelium-derived cells in lung morphogenesis and involve the Wilms' tumor suppressor gene in the development of this organ.
Thioredoxin-1 mediates hypoxia-induced pulmonary artery smooth muscle cell proliferation
Authors: Chen Bernadette , Nelin Viktoria E. , Locy Morgan L. , Jin Yi , Tipple Trent E.
Published: June 2013

Pathological pulmonary artery smooth muscle cell (PASMC) proliferation contributes to pulmonary vascular remodeling in pulmonary hypertensive diseases associated with hypoxia. Both the hypoxia-inducible factor (HIF) and phosphatidylinositol 3-kinase (PI3K)/serine/threonine kinase (Akt) pathways have been implicated in hypoxia-induced PASMC proliferation. Thioredoxin-1 (Trx1) is a ubiquitously expressed protein that is involved in redox-dependent signaling via HIF and PI3K-Akt in cancer. The role of Trx1 in PASMC proliferation has not been elucidated. The present studies tested the hypothesis that Trx1 regulates hypoxia-induced PASMC proliferation via HIF and/or PI3K- and Akt-dependent mechanisms. Following exposure to chronic hypoxia, our data indicate that Trx1 activity is increased in adult murine lungs. Furthermore, hypoxia-induced increases in cellular proliferation are correlated with increased Trx1 expression, HIF activation, and Akt activation in cultured human PASMC. Both small-interfering RNA-mediated knockdown and pharmacological Trx1 inhibition attenuated hypoxia-induced PASMC proliferation, HIF activation, and Akt activation. While Trx1 knockdown suppressed hypoxia-induced PI3K-Akt activation in PASMC, PI3K-Akt inhibition prevented hypoxia-induced proliferation but had no effect on hypoxia-induced increases in Trx1 or HIF activation. Thus, our findings indicate that Trx1 contributes to hypoxia-induced PASMC proliferation by modulating HIF activation and subsequent PI3K-Akt activation. These novel data suggest that Trx1 might represent a novel therapeutic target to prevent hypoxic PASMC proliferation.
Comparison of single- or multifrequency bioelectrical impedance analysis and spectroscopy for assessment of appendicular skeletal muscle in the elderly
Authors: Yamada Yosuke , Watanabe Yuya , Ikenaga Masahiro , Yokoyama Keiichi , Yoshida Tsukasa , Morimoto Taketoshi , Kimura Misaka
Published: June 2013

Bioelectrical impedance analysis (BIA) is used to assess skeletal muscle mass, although its application in the elderly has not been fully established. Several BIA modalities are available: single-frequency BIA (SFBIA), multifrequency BIA (MFBIA), and bioelectrical impedance spectroscopy (BIS). The aim of this study was to examine the difference between SFBIA, MFBIA, and BIS for assessment of appendicular skeletal muscle strength in the elderly. A total of 405 elderly (74.2 ± 5.0 yr) individuals were recruited. Grip strength and isometric knee extension strength were measured. Segmental SFBIA, MFBIA, and BIS were measured for the arms and upper legs. Bioelectrical impedance indexes were calculated by squared segment length divided by impedance ( L2/Z). Impedance at 5 and 50 kHz (Z5 and Z50) was used for SFBIA. Impedance of the intracellular component was calculated from MFBIA (Z250-5) and BIS (RICW). Correlation coefficients between knee extension strength and L2/Z5, L2/Z50, L2/RICW, and L2/Z250-5 of the upper legs were 0.661, 0.705, 0.790, and 0.808, respectively ( P < 0.001). Correlation coefficients were significantly greater for MFBIA and BIS than SFBIA. Receiver operating characteristic curves showed that L2/Z250-5 and L2/RICW had significantly larger areas under the curve for the diagnosis of muscle weakness compared with L2/Z5 and L2/Z50. Very similar results were observed for grip strength. Our findings suggest that MFBIA and BIS are better methods than SFBIA for assessing skeletal muscle strength in the elderly.
Electrical stimulation of the hypoglossal nerve: a potential therapy
Authors: Schwartz Alan R. , Smith Philip L. , Oliven Arie
Published: June 2013

Obstructive sleep apnea is characterized by recurrent episodes of pharyngeal collapse, which result from a decrease in pharyngeal dilator muscle tone. The genioglossus is a major pharyngeal dilator that maintains airway patency during sleep. Early studies in animal and humans have demonstrated that electrical stimulation of this muscle reduces pharyngeal collapsibility, increases airflow, and mitigates obstructive sleep apnea. These findings impelled the development of fully implantable hypoglossal nerve stimulating systems (HGNS), for which feasibility trial results are now available. These pilot studies have confirmed that hypoglossal nerve stimulation can prevent pharyngeal collapse without arousing patients from sleep. Potentially, a substantial segment of the patient population with obstructive sleep apnea can be treated with this novel approach. Furthermore, the feasibility trial findings suggest that the therapeutic potential of HGNS can be optimized by selecting patients judiciously, titrating the stimulus intensity optimally, and characterizing the underlying function and anatomy of the pharynx. These strategies are currently being examined in ongoing pivotal trials of HGNS.
Physiological and metabolic responses of late pregnant women to 40 min of steady-state exercise followed by an oral glucose tolerance perturbation
Authors: Mottola Michelle F. , Inglis Stuart , Brun Chantale R. , Hammond Jo-Anne
Published: June 2013

We examined the physiological and metabolic responses of 24 active late pregnant women to 40 min of vigorous (95% ventilatory threshold) steady-state treadmill exercise followed by a metabolic perturbation [oral glucose tolerance test (OGTT), 75 g] after exercise. Heart rate and respiratory measures were taken throughout exercise, and blood samples were collected during exercise and every 30 min during the 2-h OGTT. Values were compared with those for a group of physically active nonpregnant women ( n = 16) in the luteal phase of the menstrual cycle. Although late pregnant women were heavier, they performed the same work rate (182 vs. 208 W, P > 0.05), with the same oxygen pulse, but responded to the exercise with a blunted heart rate and relative oxygen consumption, with less carbon dioxide expired, possibly due to pregnancy-related adaptations in heart efficiency. Resting glucose concentrations were the same between groups, but by 40 min of exercise (3.8 ± 0.1 vs. 4.6 ± 0.1 mmol/l) and into 15 min of recovery (4.3 ± 0.2 vs. 5.0 ± 0.1 mmol/l), glucose concentrations were diminished in late pregnant women ( P ≤ 0.05, respectively). The pregnancy-induced delay of glucose uptake was seen in response to the postexercise OGTT compared with the nonpregnant women, but insulin sensitivity (ISI) remained (7.4 ± 0.9 vs. 9.7 ± 1.4 ISI, P > 0.05, respectively), with the preservation of the sensitivity of lipolysis inhibition of nonesterified free fatty acids to insulin. These adaptations may be fetoprotective, because our research suggests that 40 min of continuous treadmill exercise is well tolerated by physically active pregnant women. No adverse effects on birth outcome (3.53 ± 0.08 kg birth weight; 39.6 ± 0.33 wk gestational age) were observed.
Muscle metabolism and activation heterogeneity by combined31P chemical shift and T2imaging, and pulmonary O2uptake during incremental knee-extensor exercise
Authors: Cannon Daniel T. , Howe Franklyn A. , Whipp Brian J. , Ward Susan A. , McIntyre Dominick J. , Ladroue Christophe , Griffiths John R. , Kemp Graham J. , Rossiter Harry B.
Published: June 2013

The integration of skeletal muscle substrate depletion, metabolite accumulation, and fatigue during large muscle-mass exercise is not well understood. Measurement of intramuscular energy store degradation and metabolite accumulation is confounded by muscle heterogeneity. Therefore, to characterize regional metabolic distribution in the locomotor muscles, we combined31P magnetic resonance spectroscopy, chemical shift imaging, and T2-weighted imaging with pulmonary oxygen uptake during bilateral knee-extension exercise to intolerance. Six men completed incremental tests for the following: 1) unlocalized31P magnetic resonance spectroscopy; and 2) spatial determination of31P metabolism and activation. The relationship of pulmonary oxygen uptake to whole quadriceps phosphocreatine concentration ([PCr]) was inversely linear, and three of four knee-extensor muscles showed activation as assessed by change in T2. The largest changes in [PCr], [inorganic phosphate] ([Pi]) and pH occurred in rectus femoris, but no voxel (72 cm3) showed complete PCr depletion at exercise cessation. The most metabolically active voxel reached 11 ± 9 mM [PCr] (resting, 29 ± 1 mM), 23 ± 11 mM [Pi] (resting, 7 ± 1 mM), and a pH of 6.64 ± 0.29 (resting, 7.08 ± 0.03). However, the distribution of31P metabolites and pH varied widely between voxels, and the intervoxel coefficient of variation increased between rest (∼10%) and exercise intolerance (∼30–60%). Therefore, the limit of tolerance was attained with wide heterogeneity in substrate depletion and fatigue-related metabolite accumulation, with extreme metabolic perturbation isolated to only a small volume of active muscle (<5%). Regional intramuscular disturbances are thus likely an important requisite for exercise intolerance. How these signals integrate to limit muscle power production, while regional “recruitable muscle” energy stores are presumably still available, remains uncertain.
Regional cerebral blood flow in humans at high altitude: gradual ascent and 2 wk at 5,050 m
Authors: Willie C. K. , Smith K. J. , Day T. A. , Ray L. A. , Lewis N. C. S. , Bakker A. , Macleod D. B. , Ainslie P. N.
Published: June 2013

The interindividual variation in ventilatory acclimatization to high altitude is likely reflected in variability in the cerebrovascular responses to high altitude, particularly between brain regions displaying disparate hypoxic sensitivity. We assessed regional differences in cerebral blood flow (CBF) measured with Duplex ultrasound of the left internal carotid and vertebral arteries. End-tidal Pco2, oxyhemoglobin saturation (SpO2), blood pressure, and heart rate were measured during a trekking ascent to, and during the first 2 wk at, 5,050 m. Transcranial color-coded Duplex ultrasound (TCCD) was employed to measure flow and diameter of the middle cerebral artery (MCA). Measures were collected at 344 m (TCCD-baseline), 1,338 m (CBF-baseline), 3,440 m, and 4,371 m. Following arrival to 5,050 m, regional CBF was measured every 12 h during the first 3 days, once at 5–9 days, and once at 12–16 days. Total CBF was calculated as twice the sum of internal carotid and vertebral flow and increased steadily with ascent, reaching a maximum of 842 ± 110 ml/min (+53 ± 7.6% vs. 1,338 m; mean ± SE) at ∼60 h after arrival at 5,050 m. These changes returned to +15 ± 12% after 12–16 days at 5,050 m and were related to changes in SpO2( R2= 0.36; P < 0.0001). TCCD-measured MCA flow paralleled the temporal changes in total CBF. Dilation of the MCA was sustained on days 2 (+12.6 ± 4.6%) and 8 (+12.9 ± 2.9%) after arrival at 5,050 m. We observed no significant differences in regional CBF at any time point. In conclusion, the variability in CBF during ascent and acclimatization is related to ventilatory acclimatization, as reflected in changes in SpO2.
AltitudeOmics: on the consequences of high-altitude acclimatization for the development of fatigue during locomotor exercise in humans
Authors: Amann Markus , Goodall Stuart , Twomey Rosie , Subudhi Andrew W. , Lovering Andrew T. , Roach Robert C.
Published: June 2013

The development of muscle fatigue is oxygen (O2)-delivery sensitive [arterial O2 content (CaO2) × limb blood flow ( QL)]. Locomotor exercise in acute hypoxia (AH) is, compared with sea level (SL), associated with reduced CaO2 and exaggerated inspiratory muscle work (Winsp), which impairs QL, both of which exacerbate fatigue individually by compromising O2 delivery. Since chronic hypoxia (CH) normalizes CaO2 but exacerbates Winsp, we investigated the consequences of a 14-day exposure to high altitude on exercise-induced locomotor muscle fatigue. Eight subjects performed the identical constant-load cycling exercise (138 ± 14 W; 11 ± 1 min) at SL (partial pressure of inspired O2, 147.1 ± 0.5 Torr), in AH (73.8 ± 0.2 Torr), and in CH (75.7 ± 0.1 Torr). Peripheral fatigue was expressed as pre- to postexercise percent reduction in electrically evoked potentiated quadriceps twitch force (ΔQtw,pot). Central fatigue was expressed as the exercise-induced percent decrease in voluntary muscle activation (ΔVA). Resting CaO2 at SL and CH was similar, but CaO2 in AH was lower compared with SL and CH (17.3 ± 0.5, 19.3 ± 0.7, 20.3 ± 1.3 ml O2/dl, respectively). Winsp during exercise increased with acclimatization (SL: 387 ± 36, AH: 503 ± 53, CH: 608 ± 67 cmH2O·s−1·min−1; P < 0.01). Exercise at SL did not induce central or peripheral fatigue. ΔQtw,pot was significant but similar in AH and CH (21 ± 2% and 19 ± 3%; P = 0.24). ΔVA was significant in both hypoxic conditions but smaller in CH vs. AH (4 ± 1% vs. 8 ± 2%; P < 0.05). In conclusion, acclimatization to severe altitude does not attenuate the substantial impact of hypoxia on the development of peripheral fatigue. In contrast, acclimatization attenuates, but does not eliminate, the exacerbation of central fatigue associated with exercise in severe AH.
Combined effects of inspired oxygen, carbon dioxide, and carbon monoxide on oxygen transport and aerobic capacity
Authors: Crocker George H. , Toth Balazs , Jones James H.
Published: June 2013

We hypothesized that breathing hypoxic, hypercapnic, and CO-containing gases together reduces maximal aerobic capacity (V̇o2max) as the sum of each gas' individual effect on V̇o2max. To test this hypothesis, goats breathed combinations of inspired O2fraction (FiO2) of 0.06–0.21 and inspired CO2fraction of 0.00 or 0.05, with and without inspired CO that elevated carboxyhemoglobin fraction (FHbCO) to 0.02–0.45, while running on a treadmill at speeds eliciting V̇o2max. Individually, hypoxia and elevated FHbCOdecreased fractional V̇o2max(FV̇o2max, fraction of a goat's V̇o2maxbreathing air) in linear, dose-dependent manners; hypercapnia did not change V̇o2max. Concomitant hypoxia and elevated FHbCOdecreased V̇o2maxless than the individual gas effects summed, indicating their combined effects on V̇o2maxare attenuated, fitting the following regression: FV̇o2max= 4.24 FiO2+ 0.519 FHbCO− 8.22 (FiO2× FHbCO) + 0.117, ( R2= 0.965, P < 0.001). The FV̇o2maxcorrelated highly with total cardiopulmonary O2delivery, not peripheral diffusing capacity, and with arterial O2concentration (CaO2), not cardiac output. Hypoxia and elevated FHbCOdecreased CaO2by different mechanisms: hypoxia decreased arterial O2saturation (SaO2), whereas elevated FHbCOdecreased O2capacitance {concentration of hemoglobin (Hb) available to bind O2([Hbavail])}. When breathing hypoxic gas (FiO20.12), CaO2did not change with increasing FHbCOup to 0.30 because higher SaO2of Hbavailoffset decreased [Hbavail] due to the following: 1) hyperventilation with hypoxia and/or elevated FHbCO; 2) increased Hb affinity for O2due to both Bohr and direct carboxyhemoglobin effects; and 3) the sigmoid relationship between O2saturation and partial pressure elevating SaO2more with hypoxia than normoxia.
Divide-by-Three Injection-Locked Frequency Dividers with Direct Forcing Signal
Authors: Buonomo Antonio , Lo Schiavo Alessandro
Published: July 2013

Divide-by-three frequency dividers with direct forcing signal are analyzed, and the actual locking mechanism underlying their operation is highlighted. In particular, it is shown that the locking mechanism cannot be explained with the mixing between signals, as commonly made in the literature. An analytical procedure based on the averaging method is developed for solving the equation describing such dividers, and the first approximation to the oscillation in the locked states is predicted. The amplitude and phase of the output voltage in steady state as well as the locking range are derived in terms of the circuit parameters, obtaining useful design guidelines. The derived results are shown to be very close to SPICE simulations for a 0.13 um RF-CMOS process.
Four Hour Temporal Relation of 5-HTP and L-DOPA Induces Inhibitory Responses in Recrudescing Gonad of Indian Palm Squirrel (Funambulus pennantii)
Authors: Jaiwal Ranjana , Chaturvedi C. M.
Published: July 2013

Daily injections of L-dihydroxyphenylalanine (L-DOPA, dopamine precursor) given 4 h after 5-hydroxytryptophan (5-HTP, serotonin precursor) induced inhibitory responses in recrudescing gonad (in the first week of December) of Indian palm squirrel, a seasonally breeding subtropical animal. Other temporal relations (L-DOPA given at 0, 8, 12, 16, and 20 h after 5-HTP administration) did not show any effect on the recrudescing gonad. This inhibitory effect of 4 h was evident under short day length (6 : 18) group but was masked by the increasing day length of nature (NDL, late December onwards) and increased photoperiod of long day group (16 : 8). It is apparent that seasonal testicular recrudescence of Indian palm squirrel during short day length by 4 h relation of 5-HTP and L-DOPA is not a pharmacological effect but actually is an alteration of seasonality in this annually breeding mammal. It seems that endogenous mechanism controlling seasonal testicular recrudescence of Indian palm squirrel is reset by timed daily injections of these neurotransmitter drugs. It is suggested that in spite of different environmental factors (photoperiod, humidity, etc.) used by different species to time their annual reproduction, basic mechanism of seasonality appears to be the same, that is, the temporal synergism of neurotransmitter activity.
Design of a New Virtual Interaction Based PLC Training Using Virtual Sensors and Actuators: System and Its Application
Authors: Kim Yoon Sang , Kim Hak-Man
Published: July 2013

This paper proposes a new virtual interaction based programmable logic controller (PLC) training system using virtual sensors and actuators. The proposed system is composed of four components including virtual sensors (for interacting between user and input devices), virtual actuators (for manipulating and controlling device or equipment), virtual PLC (for programming and generating command), and virtual networks (for interfacing the interactions and transferring the data between all the components). The proposed system is applied to a real training program of the university's training center to examine the applicability and feasibility, and the results are analyzed and discussed.
Partial Characterization of Immunoglobulin CμGene of Water Buffalo (Bubalus bubalis) Predicts Distinct Structural Features of C1q-Binding Site in Cμ3 Domain
Authors: Saini Surinder S. , Maiti N. K. , Kaushik Azad K.
Published: July 2013

Partial characterization of immunoglobulin Cµgene of water buffalo (Bubalus bubalis) revealed high amino acid sequence identity with Cµof cattle (94.28%) and sheep (91.71%). Four amino acid replacements (Met-301, Val-310, Asn-331, and Thr-432) in Cµ2, Cµ3, and Cµ4 of buffalo IgM are distinct, however. Unlike cattle, a codon deletion (GTG encoding valine at position 507 in cattle) and an insertion (GGC encoding glycine at position 532) occur in buffalo Cµ4. Three N-linked glycosylation (Asn-X-Thr/Ser) sites (one at position 325–327 in Cµ2; two at positions 372–374 and 394–396 in Cµ3) differentiate buffalo IgM from cattle and sheep. Similar to cattle, buffalo IgM has fewer prolines in Cµ2, which acts as hinge, which restricts Fab arm flexibility. Increased structural flexibility of the C1q-binding site in Cµ3 compensates for the rigid buffalo Cµ2 domain. Secondary structure of C1q-binding site is distinct in buffalo and cattle IgM where long alpha-helical structure is predominant that may be relevant to complement fixation function. Conserved protein motif “Thr-Cys-Thr-Val-Ala-His” provides protein signatures of C1q-binding region of ruminant species. The distinct structural features of C1q-binding site of buffalo and cattle IgM seem to be of functional significance and, therefore, useful in designing antibody based therapeutics.
One‐Step Synthesis and Characterization of Silica Nano‐/Submicron Spheres by Catalyst‐Assisted Pyrolysis of a Preceramic Polymer
Authors: Gao Feng , Peng Zhijian , Fu Xiuli
Published: July 2013

Silica nanospheres have attracted tremendous interest due to their importance in extensive applications. However, the direct large‐scale fabrication of silica nanospheres with controlled morphology and high purity remains a significant challenge. In this work, silica nano‐/submicron spheres were successfully synthesized by a simple method through pyrolysis of an amorphous polysilazane preceramic powder with catalyst FeCl2. The synthesized spheres possess well‐designed shape with diameter of 600–800 nm and high purity. The surfaces of the spheres are smooth and clean without any flaws. Besides, the spheres are identified as amorphous silica, and their growth mechanism was also proposed.
Optimisation of Ionic Models to Fit Tissue Action Potentials: Application to 3D Atrial Modelling
Authors: Al Abed Amr , Guo Tianruo , Lovell Nigel H. , Dokos Socrates
Published: July 2013

A 3D model of atrial electrical activity has been developed with spatially heterogeneous electrophysiological properties. The atrial geometry, reconstructed from the male Visible Human dataset, included gross anatomical features such as the central and peripheral sinoatrial node (SAN), intra-atrial connections, pulmonary veins, inferior and superior vena cava, and the coronary sinus. Membrane potentials of myocytes from spontaneously active or electrically pacedin vitrorabbit cardiac tissue preparations were recorded using intracellular glass microelectrodes. Action potentials of central and peripheral SAN, right and left atrial, and pulmonary vein myocytes were each fitted using a generic ionic model having three phenomenological ionic current components: one time-dependent inward, one time-dependent outward, and one leakage current. To bridge the gap between the single-cell ionic models and the gross electrical behaviour of the 3D whole-atrial model, a simplified 2D tissue disc with heterogeneous regions was optimised to arrive at parameters for each cell type under electrotonic load. Parameters were then incorporated into the 3D atrial model, which as a result exhibited a spontaneously active SAN able to rhythmically excite the atria. The tissue-based optimisation of ionic models and the modelling process outlined are generic and applicable to image-based computer reconstruction and simulation of excitable tissue.
Critical Tumor Suppressor Function Mediated by Epithelial Mig-6 in Endometrial Cancer
Authors: Kim Tae Hoon , Lee Dong-Kee , Cho Sung-Nam , Orvis Grant D. , Behringer Richard R. , Lydon John P. , Ku Bon Jeong , McCampbell Adrienne S. , Broaddus Russell R. , Jeong Jae-Wook
Published: June 2013

Endometrial cancer is preceded by endometrial hyperplasia, unopposed estrogen exposure, and genetic alterations, but the precise causes of endometrial cancer remain uncertain. Mig-6, mainly known as a negative regulator of the EGF receptor, is an important mediator of progesterone signaling in the uterus, where it mediates tumor suppression by modulating endometrial stromal–epithelial communications. In this study, we investigated the function of Mig-6 in the uterine epithelium using a tissue-specific gene knockout strategy, in which floxed Mig-6 (Mig-6f/f) mice were crossed to Wnt7a-Cre mice (Wnt7acre+Mig-6f/f). Wnt7acre+Mig-6f/f mice developed endometrial hyperplasia and estrogen-dependent endometrial cancer, exhibiting increased proliferation in epithelial cells as well as apoptosis in subepithelial stromal cells. We documented increased expression of NOTCH1 and BIRC3 in epithelial cells of Wnt7acre+Mig-6f/f mice and decreased expression of the progesterone receptor (PR) in stromal cells. Progesterone therapy controls endometrial growth and prevents endometrial cancer, but the effectiveness of progesterone as a treatment for women with endometrial cancer is less clear. We noted that the hyperplasic phenotype of Wnt7acre+Mig-6f/f mice was prevented by progesterone treatment, whereas this treatment had no effect in PRcre/+Mig-6f/f mice where Mig-6 was deleted in both the epithelial and stromal compartments of the uterus. In contrast, activation of progesterone signaling in the stroma regulated proliferation and apoptosis in the epithelium via suppression of ERα signaling. In summary, our results establish that epithelial Mig-6 functions as a critical tumor suppressor that mediates the ability of progesterone to prevent the development of endometrial cancer. Cancer Res; 73(16); 5090–9. ©2013 AACR.
AC1MMYR2, an Inhibitor of Dicer-Mediated Biogenesis of Oncomir miR-21, Reverses Epithelial–Mesenchymal Transition and Suppresses Tumor Growth and Progression
Authors: Shi Zhendong , Zhang Junxia , Qian Xiaomin , Han Lei , Zhang Kailiang , Chen Luyue , Liu Jilong , Ren Yu , Yang Ming , Zhang Anling , Pu Peiyu , Kang Chunsheng
Published: June 2013

The extensive involvement of miRNAs in cancer pathobiology has opened avenues for drug development based on oncomir inhibition. Dicer is the core enzyme in miRNA processing that cleaves the terminal loop of precursor microRNAs (pre-miRNAs) to generate mature miRNA duplexes. Using the three-dimensional structure of the Dicer binding site on the pre-miR-21 oncomir, we conducted an in silico high-throughput screen for small molecules that block miR-21 maturation. By this method, we identified a specific small-molecule inhibitor of miR-21, termed AC1MMYR2, which blocked the ability of Dicer to process pre-miR-21 to mature miR-21. AC1MMYR2 upregulated expression of PTEN, PDCD4, and RECK and reversed epithelial–mesenchymal transition via the induction of E-cadherin expression and the downregulation of mesenchymal markers, thereby suppressing proliferation, survival, and invasion in glioblastoma, breast cancer, and gastric cancer cells. As a single agent in vivo, AC1MMYR2 repressed tumor growth, invasiveness, and metastasis, increasing overall host survival with no observable tissue cytotoxicity in orthotopic models. Our results offer a novel, high-throughput method to screen for small-molecule inhibitors of miRNA maturation, presenting AC1MMYR2 as a broadly useful candidate antitumor drug. Cancer Res; 73(17); 5519–31. ©2013 AACR.
PPARδ Induces Estrogen Receptor-Positive Mammary Neoplasia through an Inflammatory and Metabolic Phenotype Linked to mTOR Activation
Authors: Yuan Hongyan , Lu Jin , Xiao Junfeng , Upadhyay Geeta , Umans Rachel , Kallakury Bhaskar , Yin Yuhzi , Fant Michael E. , Kopelovich Levy , Glazer Robert I.
Published: June 2013

The peroxisome proliferator-activated receptor-δ (PPARδ) regulates a multitude of physiological processes associated with glucose and lipid metabolism, inflammation, and proliferation. One or more of these processes are potential risk factors for the ability of PPARδ agonists to promote tumorigenesis in the mammary gland. In this study, we describe a new transgenic mouse model in which activation of PPARδ in the mammary epithelium by endogenous or synthetic ligands resulted in progressive histopathologic changes that culminated in the appearance of estrogen receptor- and progesterone receptor-positive and ErbB2-negative infiltrating ductal carcinomas. Multiparous mice presented with mammary carcinomas after a latency of 12 months, and administration of the PPARδ ligand GW501516 reduced tumor latency to 5 months. Histopathologic changes occurred concurrently with an increase in an inflammatory, invasive, metabolic, and proliferative gene signature, including expression of the trophoblast gene, Plac1, beginning 1 week after GW501516 treatment, and remained elevated throughout tumorigenesis. The appearance of malignant changes correlated with a pronounced increase in phosphatidylcholine and lysophosphatidic acid metabolites, which coincided with activation of Akt and mTOR signaling that were attenuated by treatment with the mTOR inhibitor everolimus. Our findings are the first to show a direct role of PPARδ in the pathogenesis of mammary tumorigenesis, and suggest a rationale for therapeutic approaches to prevent and treat this disease. Cancer Res; 73(14); 4349–61. ©2013 AACR.
Targeting ERBB Receptors Shifts Their Partners and Triggers Persistent ERK Signaling through a Novel ERBB/EFNB1 Complex
Authors: Vermeer Paola D. , Colbert Paul L. , Wieking Bryant G. , Vermeer Daniel W. , Lee John H.
Published: June 2013

Most squamous cell carcinomas of the head and neck (HNSCC) overexpress ERBB1/EGFR, but EGF receptor (EGFR)-targeted therapies have yielded disappointing clinical results in treatment of this cancer. Here, we describe a novel interaction between EGFR and the ligand EphrinB1 (EFNB1), and we show that EFNB1 phosphorylation and downstream signaling persists in the presence of cetuximab. Mechanistically, cetuximab drives a shift in EGFR dimerization partners within the signaling complex, suggesting that targeted drugs may trigger partner rearrangements that allow persistent pathway activation. EFNB1 attenuation slowed tumor growth and increased survival in a murine model of HNSCC, suggesting a substantial contribution of EFNB1 signaling to HNSCC development. Together, our findings suggest that EFNB1 is part of the EGFR signaling complex and may mediate drug resistance in HNSCC as well as other solid tumors. Cancer Res; 73(18); 5787–97. ©2013 AACR.
Clinical Significance and Prognostic Value of microRNA Expression Signatures in Hepatocellular Carcinoma
Authors: Wei Rongrong , Huang Guo-Liang , Zhang Mei-Yin , Li Bin-Kui , Zhang Hui-Zhong , Shi Ming , Chen Xiao-Qian , Huang Long , Zhou Qing-Ming , Jia Wei-Hua , Zheng X.F. Steven , Yuan Yun-Fei , Wang Hui-Yun
Published: June 2013

Purpose: MicroRNAs (miRNAs) play important roles in the development and progression of cancer. The aim of this study is to identify miRNA expression signatures in hepatocellular carcinoma and delineate their clinical significance for hepatocellular carcinoma.

Experimental Design: Patients with hepatocellular carcinoma, undergoing hepatectomy were randomly divided into training set (60 patients) and test set (50 patients). Other 56 patients were used as an independent cohort. The miRNA expression levels were detected by microarray and verified by quantitative real-time reverse transcription-PCR (qRT-PCR).

Results: A 30-miRNA signature consisting of 10 downregulated and 20 upregulated miRNAs was established for distinguishing hepatocellular carcinoma from noncancerous liver tissues in the training set with 99.2% accuracy. The classification accuracies of this signature were 97% and 90% in the test set and independent cohort, respectively. The expression level of four miRNAs in the 30-miRNA signature was verified by qRT-PCR in the training set. Twenty miRNAs were then selected to construct prognostic signature in the training set. Of the 20 miRNAs, six were risk factors and 14 were protective factors. A formula based on the 20 miRNAs was built to compute prognostic index. Kaplan–Meier analysis showed that patients with a higher prognostic index had a significantly lower survival than those with a low index. This was verified in the test and independent sets. Multivariate analysis indicated that the 20-miRNA signature was an independent prognostic predictor.

Conclusions: The 30- and 20-miRNA signatures identified in this study should provide new molecular approaches for diagnosis and prognosis of patients with hepatocellular carcinoma and clues for elucidating molecular mechanism of hepatocarcinogenesis. Clin Cancer Res; 19(17); 4780–91. ©2013 AACR.
Vemurafenib Synergizes with Nutlin-3 to Deplete Survivin and Suppresses Melanoma Viability and Tumor Growth
Authors: Ji Zhenyu , Kumar Raj , Taylor Michael , Rajadurai Anpuchchelvi , Marzuka-Alcalá Alexander , Chen Y. Erin , Njauw Ching-Ni Jenny , Flaherty Keith , Jönsson Göran , Tsao Hensin
Published: June 2013

Purpose: For patients with advanced melanoma, primary and secondary resistance to selective BRAF inhibition remains one of the most critically compelling challenges. One rationale argues that novel biologically informed strategies are needed to maximally cripple melanoma cells up front before compensatory mechanisms emerge. As p53 is uncommonly mutated in melanoma, restoration of its function represents an attractive adjunct to selective BRAF inhibition.

Experimental Design: Thirty-seven BRAF(V600E)-mutated melanoma lines were subjected to synergy studies in vitro using a combination of vemurafenib and nutlin-3 (Nt-3). In addition, cellular responses and in vivo efficacy were also determined. We also analyzed changes in the levels of canonical apoptotic/survival factors in response to vemurafenib.

Results: Dual targeting of BRAF(V600E) and Hdm2 with vemurafenib and Nt-3, respectively, synergistically induced apoptosis and suppressed melanoma viability in vitro and tumor growth in vivo. Suppression of p53 in melanoma cells abrogated Nt-3′s effects fully and vemurafenib's effects partially. A survey of canonical survival factors revealed that both vemurafenib and Nt-3 independently attenuated levels of the antiapoptotic protein, survivin. Genetic depletion of survivin reproduces the cytotoxic effects of the combination strategy.

Conclusion: These results show preclinical feasibility for overcoming primary vemurafenib resistance by restoring p53 function. Moreover, it identifies survivin as one downstream mediator of the observed synergism and a potential secondary target. Clin Cancer Res; 19(16); 4383–91. ©2013 AACR.
Towards Sustained Silencing of HER2/neu in Cancer By Epigenetic Editing
Authors: Falahi Fahimeh , Huisman Christian , Kazemier Hinke G. , van der Vlies Pieter , Kok Klaas , Hospers Geke A.P. , Rots Marianne G.
Published: June 2013

The human epidermal growth factor receptor-2 (HER2/neu/ERBB2) is overexpressed in several cancer types. Although therapies targeting the HER2/neu protein result in inhibition of cell proliferation, the anticancer effect might be further optimized by limiting HER2/neu expression at the DNA level. Towards this aim, epigenetic editing was performed to suppress HER2/neu expression by inducing epigenetic silencing marks on the HER2/neu promoter.HER2/neu expression and HER2/neu promoter epigenetic modification status were determined in a panel of ovarian and breast cancer cell lines. HER2/neu-overexpressing cancer cells were transduced to express a zinc finger protein (ZFP), targeting the HER2/neugene, fused to histone methyltransferases (G9a, SUV39-H1)/super KRAB domain (SKD). Epigenetic assessment of the HER2/neu promoter showed that HER2/neu-ZFP fused to G9a efficiently induced the intended silencing histone methylation mark (H3K9me2). Importantly, H3K9me2 induction was associated with a dramatic downregulation of HER2/neu expression in HER2/neu- overexpressing cells. Downregulation by SKD, traditionally considered transient in nature, was associated with removal of the histone acetylation mark (H3ac). The downregulation of HER2/neu by induced H3K9 methylation and/or reduced H3 acetylation was sufficient to effectively inhibit cellular metabolic activity and clonogenicity. Furthermore, genome-wide analysis indicated preferential binding of the ZFP to its target sequence. These results not only show that H3K9 methylation can be induced but also that this epigenetic mark was instructive in promoting downregulation of HER2/neu expression.

Implications: Epigenetic editing provides a novel (synergistic) approach to modulate expression of oncogenes. Mol Cancer Res; 11(9); 1029–39. ©2013 AACR.
PTP1B Contributes to Calreticulin-Induced Metastatic Phenotypes in Esophageal Squamous Cell Carcinoma
Authors: Wang Xiao-Min , Shang Li , Zhang Yu , Hao Jia-Jie , Shi Feng , Luo Wei , Zhang Tong-Tong , Wang Bo-Shi , Yang Yang , Liu Zhi-Hua , Zhan Qi-Min , Wang Ming-Rong
Published: June 2013

Calreticulin (CRT) is a Ca2+-binding chaperone protein that alters cellular Ca2+-homeostasis in the endoplasmic reticulum (ER). Previously it was shown that CRT was overexpressed in esophageal squamous cell carcinoma (ESCC), and elevated CRT expression promoted the migration and invasion of ESCC cells. In the present study, the mechanisms underlying the role of CRT in esophageal carcinoma progression were investigated. Critically, depletion of CRT or protein-tyrosine phosphatase 1B (PTP1B) reduced ESCC cell migration and metastasis to the lung, whereas restoration of PTP1B protein levels rescued cell migration in CRT-silenced cells. Knockdown of CRT decreased PTP1B protein expression by reducing phosphorylation at the Y694 site of STAT5A, whereas knockdown of PTP1B reduced ERK1/2 phosphorylation at T204. Immunohistochemical analysis of CRT and PTP1B expression in ESCC patient tissues was strongly correlated. Importantly, PTP1B expression was associated with poor survival in patients with CRT overexpression. Overall, these data indicate a novel signaling pathway connecting CRT, STAT5A, PTP1B, and ERK1/2 in the regulation of ESCC cell migration.

Implications: These findings suggest that PTP1B is a downstream effector of CRT signaling, promotes tumor progression, and can potentially be used as a new drug target for ESCC. Mol Cancer Res; 11(9); 986–94. ©2013 AACR.
Molecular Classification of Prostate Cancer Progression: Foundation for Marker-Driven Treatment of Prostate Cancer
Authors: Logothetis Christopher J. , Gallick Gary E. , Maity Sankar N. , Kim Jeri , Aparicio Ana , Efstathiou Eleni , Lin Sue-Hwa
Published: June 2013

Recently, many therapeutic agents for prostate cancer have been approved that target the androgen receptor and/or the prostate tumor microenvironment. Each of these therapies has modestly increased patient survival. A better understanding of when in the course of prostate cancer progression specific therapies should be applied, and of what biomarkers would indicate when resistance arises, would almost certainly improve survival due to these therapies. Thus, applying the armamentarium of therapeutic agents in the right sequences in the right combination at the right time is a major goal in prostate cancer treatment. For this to occur, an understanding of prostate cancer evolution during progression is required. In this review, we discuss the current understanding of prostate cancer progression, but challenge the prevailing view by proposing a new model of prostate cancer progression, with the goal of improving biologic classification and treatment strategies. We use this model to discuss how integrating clinical and basic understanding of prostate cancer will lead to better implementation of molecularly targeted therapeutics and improve patient survival.

Significance: Rapid development of drugs with efficacy against prostate cancer now makes it possible to consider applying these agents with curative intent in men with currently incurable cancers. However, when to apply these new drugs, as well as those under development, to obtain the best outcomes is a challenge that must be addressed. To meet this challenge, better classification of the disease based on the underlying molecular mechanisms of progression will facilitate the implementation of current and emerging therapies. Cancer Discov; 3(8); 849–61. ©2013 AACR.
The Role of Innate Immunity in Promoting SaeR/S-Mediated Virulence in Staphylococcus aureus
Authors: Zurek Oliwia W. , Nygaard Tyler K. , Watkins Robert L. , Pallister Kyler B. , Torres Victor J. , Horswill Alexander R. , Voyich Jovanka M.
Published: July 2013

The ability of Staphylococcus aureus to infect tissues is dependent on precise control of virulence through gene-regulatory systems. While the SaeR/S two-component system has been shown to be a major regulator of S. aureus virulence, the influence of the host environment on SaeR/S-regulated genes (saeR/S targets) remains incompletely defined. Using QuantiGene 2.0 transcriptional assays, we examined expression of genes with the SaeR binding site in USA300 exposed to human and mouse neutrophils and host-derived peptides and during subcutaneous skin infection. We found that only some of the saeR/S targets, as opposed to the entire SaeR/S virulon, were activated within 5 and 10 min of interacting with human neutrophils as well as α-defensin. Furthermore, mouse neutrophils promoted transcription of saeR/S targets despite lacking α-defensin, and the murine skin environment elicited a distinctive expression profile of saeR/S targets. These findings indicate that saeR/S-mediated transcription is unique to and dependent on specific host stimuli. By using isogenic USA300ΔsaeR/S and USA300Δagr knockout strains, we also determined that SaeR/S is the major regulator of virulence factors, while Agr, a quorum-sensing two-component system, has moderate influence on transcription of the saeR/S targets under the tested physiological conditions.