bluuebunny/crossref_metadata_2025 huggingface dataset:
Serpentinites from Cabo Ortegal (Galicia, Spain): a search for correct use as ornamental stones
Authors: Pereira Dolores , Peinado Mercedes , Yenes Mariano , Monterrubio Serafin , Nespereira Jose , Blanco Jose Antonio
Published: April 2010

Different varieties of serpentinites present at Cabo Ortegal were studied. For many years, the ‘Verde Pirineos’ type has been quarried and sold commercially, but its physical characteristics do not fulfil the requirements for its use as an ornamental stone. ‘Piedra de Doelo’ is the local name for a serpentinite that has been quarried and used for many centuries in a large number of historical buildings distributed throughout the area. The preservation status of the rock is very poor and the stone is severely affected by weathering. A third variety, similar to the ‘ophicalcite’ described in the literature, is currently under investigation with a view to studying the possibility of the resumption of serpentinite quarrying. Although serpentinites are commercially known as ‘green marbles’, Galician serpentinites do not fulfil the mineral requirements to be described as such. Study of the characteristics of serpentinites, including their mineralogy, may offer a clue to the correct use of Galician serpentinites.
A legacy of mistreatment: conceptualizing the decay of medieval sandstones in NE Ireland
Authors: McCabe Stephen , Smith Bernard J. , Warke Patricia A.
Published: April 2010

Sandstone is commonly used as a building material in medieval monuments throughout NE Ireland. This paper explores the reasons why, and the ways in which, medieval sandstone monuments decay in the temperate Atlantic maritime environment of the north Antrim coast, using Bonamargy Friary, Ballycastle, as a case study. Monumental stone decay is placed in the context of inheritance and sensitivity to change, that is, the ability or inability of a sandstone to absorb change as a result of the past stress events it has experienced. A consideration of the combined impact of background environmental factors (such as salt accumulation, temperature cycles, frost, chemical alteration, soiling of the surface, changes in surface morphology and biological colonization) and ‘exceptional’ factors (such as lime rendering, fire, climate change, abandonment and conservation intervention) is used to formulate alternative decay pathways of the sandstones identified at the Friary. Discussion focuses on the value of identifying conceptual event sequences such as the cumulative impact of past events, individual and combined, to produce recognizable decay features seen in the present day. The possible impact of future climate change on the decay of medieval sandstone monuments is discussed.
IL-4Rα-responsive smooth muscle cells increase intestinal hypercontractility and contribute to resistance during acute Schistosomiasis
Authors: Marillier Reece G. , Brombacher Tiroyaone M. , Dewals Benjamin , Leeto Mosiuoa , Barkhuizen Mark , Govender Dhirendra , Kellaway Lauriston , Horsnell William G. C. , Brombacher Frank
Published: April 2010

Interleukin-(IL)-4 and IL-13 signal through heterodimeric receptors containing a common IL-4 receptor-α (IL-4Rα) subunit, which is important for protection against helminth infections, including schistosomiasis. Previous studies demonstrated important roles for IL-4Rα-responsive hematopoietic cells, including T cells and macrophages in schistosomiasis. In this study, we examined the role of IL-4Rα responsiveness by nonhematopoietic smooth muscle cells during experimental acute murine schistosomiasis. Comparative Schistosoma mansoni infection studies with smooth muscle cell-specific IL-4Rα-deficient (SM-MHCcreIL-4Rα−/flox) mice, heterozygous control (IL-4Rα−/flox) mice, and global IL-4Rα-deficient (IL-4Rα−/−) mice were conducted. S. mansoni -infected SM-MHCcreIL-4Rα−/floxmice showed increased weight loss and earlier mortalities compared with IL-4Rα−/floxmice, despite comparable TH2/type 2 immune responses. In contrast to highly susceptible IL-4Rα-deficient mice, increased susceptibility in SM-MHCcreIL-4Rα−/floxmice was not accompanied by intestinal tissue damage and subsequent sepsis. However, both susceptible mutant mouse strains failed to efficiently expel eggs, demonstrated by egg reduction in the feces compared with control mice. Reduced egg expulsion was accompanied by impaired IL-4/IL-13-mediated hypercontractile intestinal responses, which was present in the more resistant control mice. Together, we conclude that IL-4Rα responsiveness by smooth muscle cells and subsequent IL-4- and IL-13-mediated hypercontractility are required for host protection during acute schistosomiasis to efficiently expel S. mansoni eggs and to prevent premature mortality.
Peristalsis and fecal pellet propulsion do not require nicotinic, purinergic, 5-HT3, or NK3 receptors in isolated guinea pig distal colon
Authors: Nicholas Sarah , Spencer Nick J.
Published: April 2010

The neuronal mechanism by which distension of the colon triggers peristalsis and the propulsion of colonic contents is incompletely understood. In this study, we used video imaging and spatiotemporal mapping techniques to investigate the neuroneuronal mechanisms underlying peristalsis in isolated guinea pig distal colon. In direct contrast to previous studies, we found that hexamethonium (100 μM–1 mM) or mecamylamine (20 μM) never abolished peristalsis or fecal pellet propulsion, although a temporary blockade of peristalsis was common, giving the impression perhaps that peristalsis was blocked permanently. During the initiation of peristalsis, the intraluminal propulsive force applied to an inserted fecal pellet was significantly reduced by hexamethonium 100 μM, even though, once initiated, the propagation velocity of fecal pellets was never reduced by nicotinic antagonists. In the presence of hexamethonium or mecamylamine, further addition of PPADS (10 μM), ondansetron (1 μM), and SR 142801 (300 nM) had no inhibitory effect on the propagation velocity of fecal pellets. In these preparations, antagonists for nicotinic, purinergic (P2), serotonergic (5-HT3), or tachykinergic (NK3) receptors always abolished responses to the agonists for these receptors, confirming that when peristalsis occurred, nicotinic, P2, 5-HT3, and NK3 receptors were blocked. Tetrodotoxin abolished nonnicotinic peristalsis. In summary, nicotinic transmission contributes to excitatory neuroneuronal transmission underlying peristalsis and fecal pellet propulsion but is not required for peristalsis, nor fecal pellet propulsion, as once thought. These observations could be explained by an excitatory nonnicotinic neuroneuronal pathway that can generate peristalsis and induce normal fecal pellet propagation velocities but does not require nicotinic, P2, 5-HT3, or NK3 receptors.
Activation of transient receptor potential vanilloid subtype 1 increases secretion of the hypofunctional, transplanted submandibular gland
Authors: Zhang Y. , Cong X. , Shi L. , Xiang B. , Li Y. M. , Ding Q. W. , Ding C. , Wu L. L. , Yu G. Y.
Published: April 2010

Hyposecretion occurs in most patients early after submandibular gland autotransplantation for severe keratoconjunctivitis sicca. Endogenous transient receptor potential vanilloid subtype 1 (TRPV1) has been recently demonstrated in rabbit submandibular glands, and activation of TRPV1 by capsaicin increases secretion in isolated glands, but the TRPV1-mediated secretory mechanism remains to be elucidated. The purpose of this study was to verify whether activation of TRPV1 by capsaicin could improve the secretion of transplanted gland and its underlying mechanism. The salivary flow of the transplanted glands was significantly decreased, and the mRNA and protein levels of TRPV1 and aquaporin 5 (AQP5) were downregulated in the transplanted glands. Topical capsaicin cream increased secretion and upregulated levels of TRPV1 and AQP5 in transplanted glands. Moreover, in cultured submandibular gland cells, capsaicin increased the mRNA expression of AQP5 and led to redistribution of AQP5 from the cytoplasm to the plasma membrane via TRPV1 activation. Capsaicin enhanced the phosphorylation of extracellular signal-regulated kinase (ERK). Preincubation of cells with PD98059, an inhibitor of ERK kinase, suppressed the capsaicin-induced mRNA expression of AQP5. In summary, the capsaicin-induced secretory mechanism involved activation of TRPV1 and upregulation of AQP5 in an ERK-dependent manner and promoted the redistribution of AQP5 in submandibular gland cells. Activation of TRPV1 may provide a new therapeutic strategy to improve submandibular gland hypofunction.
Heterochromatin dysregulation in human diseases
Authors: Hahn Matthias , Dambacher Silvia , Schotta Gunnar
Published: April 2010

Heterochromatin is a repressive chromatin state that is characterized by densely packed DNA and low transcriptional activity. Heterochromatin-induced gene silencing is important for mediating developmental transitions, and in addition, it has more global functions in ensuring chromosome segregation and genomic integrity. Here we discuss how altered heterochromatic states can impair normal gene expression patterns, leading to the development of different diseases. Over the last years, therapeutic strategies that aim toward resetting the epigenetic state of dysregulated genes have been tested. However, due to the complexity of epigenetic gene regulation, the “first-generation drugs” that function globally by inhibiting epigenetic machineries might also introduce severe side effects. Thus detailed understanding of how repressive chromatin states are established and maintained at specific loci will be fundamental for the development of more selective epigenetic treatment strategies in the future.
Chronic hypercapnia alters lung matrix composition in mouse pups
Authors: Ryu Julie , Heldt Gregory P. , Nguyen Mary , Gavrialov Orit , Haddad Gabriel G.
Published: April 2010

Rationale: permissive hypercapnia, a stretch-limiting ventilation strategy, often results in high PaCO2. This strategy is associated with reduced morbidity and mortality in premature infants and its benefits have been attributed to diminished barotrauma. However, little is known about the independent effect of high CO2levels during the lung development. Methods: mice were exposed to 8% CO2or room air for 2 wk either from postnatal day 2 through 17 or as adults (∼2 mo of age). Lungs were excised and processed for protein, RNA, histology, and total lung volumes. Results: histologic analysis demonstrated that alveolar walls of CO2-exposed mouse pups were thinner than those of controls and had twice the total lung volume. Molecular analysis revealed that several matrix proteins in the lung were downregulated in mouse pups exposed to hypercapnia. Interstitial collagen type I α1, type III α1, elastin and fibronectin protein, and mRNA levels were less than half of controls while collagen IV α5 was unaffected. This decrease in interstitial collagen could thus account for the thinning of the interstitial matrix and the altered lung biomechanics. Matrix metalloproteinase (MMP)-8, a collagenase that has specificity for collagen types I and III, increased in hypercapnic mouse pups, suggesting increased collagen degradation. Moreover, tissue inhibitor of MMP (TIMP)-1, a potent inhibitor of MMP-8, was significantly decreased. However, unlike pups, adult mice exposed to hypercapnia demonstrated only a mild increase in total lung volumes and did not exhibit similar molecular or histologic changes. Conclusions: although permissive hypercapnia may prevent lung injury from barotrauma, our study revealed that exposure to hypercapnia may be an important factor in lung remodeling and function, especially in early life.
Airway response to emotional stimuli in asthma: the role of the cholinergic pathway
Authors: Ritz Thomas , Kullowatz Antje , Goldman Michael D. , Smith Hans-Jürgen , Kanniess Frank , Dahme Bernhard , Magnussen Helgo
Published: April 2010

In asthma, airways constrict in response to emotion and stress, but underlying mechanisms, potential extrathoracic contributions, and associations with airway pathophysiology have not been elucidated. We therefore investigated the role of the cholinergic pathway in emotion-induced airway responses in patients with asthma and the association of these responses with airway pathophysiology. Patients with asthma ( n = 54) and healthy participants ( n = 25) received either 40 μg ipratropium bromide or a placebo in a double-blind double-dummy cross-over design in two laboratory sessions with experimental emotion induction. Stimuli were preevaluated films and pictures of pleasant, unpleasant, and neutral quality. Respiratory resistance and reactance at 5 and 20 Hz were measured continuously before and during presentations, together with respiration by impedance plethysmography and end-tidal Pco2by capnometry. In addition, measures of airway inflammation (fraction of exhaled nitric oxide), airway hyperreactivity (methacholine challenge), and reversibility of obstruction were obtained. Respiratory resistance at 5 and 20 Hz increased during unpleasant stimuli in asthma patients. This response was blocked by ipratropium bromide and was not substantially associated with asthma severity, airway inflammation, hyperreactivity and reversibility, or pattern of ventilation and Pco2. Under the placebo condition, changes in resistance during unpleasant films were positively correlated with patients’ reports of psychological asthma triggers. In conclusion, airway constriction to unpleasant stimuli in asthma depends on an intact cholinergic pathway, is largely due to the central airways, and is not substantially associated with other indicators of airway pathology. Its link to the perceived psychological triggers in patients’ daily lives suggests a physiological basis for emotion-induced asthma.
Rho kinase activation and ROS production contributes to the cooling enhanced contraction in cutaneous equine digital veins
Authors: Zerpa H. , Berhane Y. , Woodcock H. , Elliott J. , Bailey S. R.
Published: April 2010

A decrease in environmental temperature can directly affect the contractility of cutaneous vasculature, mediated in part by α2-adrenoceptors. Most of the cellular mechanisms underlying the cooling-enhanced contractility to α2-adrenoceptor agonists have been reported in cutaneous arteries but little information is available on cutaneous veins. To investigate the cellular mechanisms associated with the cooling-enhanced contraction to UK-14304 (α2-adrenoceptor agonist), isolated equine digital veins (EDVs) were studied at 30°C and 22°C. The effects of inhibitors were studied on the contractile response to UK-14304 (0.1 μM). The cooling-enhanced responses were inhibited by Rho kinase inhibitors [maximum response to UK-14304 95.2 ± 8% of response to depolarizing Krebs solution (DKS) in control vessels cooled to 22°C, compared with 31.4 ± 6% in the presence of fasudil 1 μM and 75.8 ± 6% with Y-27632 0.1 μM] and the effects of these inhibitors were considerably less at 30°C (control response 56.4 ± 5% of DKS; 34.9 ± 6% with fasudil 1 μM and 50.6 ± 9% with Y-27632 0.1 μM). Furthermore, Western blotting showed that one of the downstream targets for Rho kinase activity, ezrin/radixin/moesin, was phosphorylated after cooling and reduced by fasudil (1 μM) only at 22°C. The activation of protein kinase C contributed to the contractile response, but predominantly at 30°C (maximum response 82.3 ± 9% of DKS for control; 57.7 ± 10% in the presence of chelerythrine 10 μM) with no significant effect at 22°C. The reduction of the response at 22°C by antioxidants, rotenone (14% reduction), and tempol (21% reduction) suggested the contribution of reactive oxygen species (ROS). No evidence was obtained to support the participation of tyrosine kinase. These data demonstrate that Rho kinase activation and the production of ROS contributes to the cooling-enhanced contraction in these cutaneous digital veins.
Respiratory and Mayer wave-related discharge patterns of raphé and pontine neurons change with vagotomy
Authors: Morris K. F. , Nuding S. C. , Segers L. S. , Baekey D. M. , Shannon R. , Lindsey B. G. , Dick T. E.
Published: April 2010

Previous models have attributed changes in respiratory modulation of pontine neurons after vagotomy to a loss of pulmonary stretch receptor “gating” of an efference copy of inspiratory drive. Recently, our group confirmed that pontine neurons change firing patterns and become more respiratory modulated after vagotomy, although average peak and mean firing rates of the sample did not increase (Dick et al., J Physiol 586: 4265–4282, 2008). Because raphé neurons are also elements of the brain stem respiratory network, we tested the hypotheses that after vagotomy raphé neurons have increased respiratory modulation and that alterations in their firing patterns are similar to those seen for pontine neurons during withheld lung inflation. Raphé and pontine neurons were recorded simultaneously before and after vagotomy in decerebrated cats. Before vagotomy, 14% of 95 raphé neurons had increased activity during single respiratory cycles prolonged by withholding lung inflation; 13% exhibited decreased activity. After vagotomy, the average index of respiratory modulation (η2) increased (0.05 ± 0.10 to 0.12 ± 0.18 SD; Student's paired t-test, P < 0.01). Time series and frequency domain analyses identified pontine and raphé neuron firing rate modulations with a 0.1-Hz rhythm coherent with blood pressure Mayer waves. These “Mayer wave-related oscillations” (MWROs) were coupled with central respiratory drive and became synchronized with the central respiratory rhythm after vagotomy (7 of 10 animals). Cross-correlation analysis identified functional connectivity in 52 of 360 pairs of neurons with MWROs. Collectively, the results suggest that a distributed network participates in the generation of MWROs and in the coordination of respiratory and vasomotor rhythms.
Systemic low-dose aspirin and clopidogrel independently attenuate reflex cutaneous vasodilation in middle-aged humans
Authors: Holowatz Lacy A. , Jennings John D. , Lang James A. , Kenney W. Larry
Published: April 2010

Chronic systemic platelet cyclooxygenase (COX) inhibition with low-dose aspirin [acetylsalicylic acid (ASA)] significantly attenuates reflex cutaneous vasodilation in middle-aged humans, whereas acute, localized, nonisoform-specific inhibition of vascular COX with intradermal administration of ketorolac does not alter skin blood flow during hyperthermia. Taken together, these data suggest that platelets may be involved in reflex cutaneous vasodilation, and this response is inhibited with systemic pharmacological platelet inhibition. We hypothesized that, similar to ASA, specific platelet ADP receptor inhibition with clopidogrel would attenuate reflex vasodilation in middle-aged skin. In a double-blind crossover design, 10 subjects (53 ± 2 yr) were instrumented with four microdialysis fibers for localized drug administration and heated to increase body core temperature [oral temperature (Tor)] 1°C during no systemic drug (ND), and after 7 days of systemic ASA (81 mg) and clopidogrel (75 mg) treatment. Skin blood flow (SkBF) was measured using laser-Doppler flowmetry over each site assigned as 1) control, 2) nitric oxide synthase inhibited (NOS-I; 10 mM NG-nitro-l-arginine methyl ester), 3) COX inhibited (COX-I; 10 mM ketorolac), and 4) NOS-I + COX-I. Data were normalized and presented as a percentage of maximal cutaneous vascular conductance (%CVCmax; 28 mM sodium nitroprusside + local heating to 43°C). During ND conditions, SkBF with change (Δ) in Tor = 1.0°C was 56 ± 3% CVCmax. Systemic low-dose ASA and clopidogrel both attenuated reflex vasodilation (ASA: 43 ± 3; clopidogrel: 32 ± 3% CVCmax; both P < 0.001). In all trials, localized COX-I did not alter SkBF during significant hyperthermia (ND: 56 ± 7; ASA: 43 ± 5; clopidogrel: 35 ± 5% CVCmax; all P > 0.05). NOS-I attenuated vasodilation in ND and ASA (ND: 28 ± 6; ASA: 25 ± 4% CVCmax; both P < 0.001), but not with clopidogrel (27 ± 4% CVCmax; P > 0.05). NOS-I + COX-I was not different compared with NOS-I alone in either systemic treatment condition. Both systemic ASA and clopidogrel reduced the time required to increase Tor 1°C (ND: 58 ± 3 vs. ASA: 45 ± 2; clopidogrel: 39 ± 2 min; both P < 0.001). ASA-induced COX and specific platelet ADP receptor inhibition attenuate reflex vasodilation, suggesting platelet involvement in reflex vasodilation through the release of vasodilating factors.
Sleep state dependence of ventilatory long-term facilitation following acute intermittent hypoxia in Lewis rats
Authors: Nakamura A. , Olson E. B. , Terada J. , Wenninger J. M. , Bisgard G. E. , Mitchell G. S.
Published: April 2010

Ventilatory long-term facilitation (vLTF) is a form of respiratory plasticity induced by acute intermittent hypoxia (AIH). Although vLTF has been reported in unanesthetized animals, little is known concerning the effects of vigilance state on vLTF expression. We hypothesized that AIH-induced vLTF is preferentially expressed in sleeping vs. awake male Lewis rats. Vigilance state was assessed in unanesthetized rats with chronically implanted EEG and nuchal EMG electrodes, while tidal volume, frequency, minute ventilation (V̇e), and CO2production were measured via plethysmography, before, during, and after AIH (five 5-min episodes of 10.5% O2separated by 5-min normoxic intervals), acute sustained hypoxia (25 min of 10.5% O2), or a sham protocol without hypoxia. Vigilance state was classified as quiet wakefulness (QW), light and deep non-rapid eye movement (NREM) sleep (l-NREM and d-NREM sleep, respectively), or rapid eye movement sleep. Ventilatory variables were normalized to pretreatment baseline values in the same vigilance state. During d-NREM sleep, vLTF was observed as a progressive increase in V̇e post-AIH (27 ± 5% average, 30–60 min post-AIH). In association, V̇e/V̇co2(36 ± 2%), tidal volume (14 ± 2%), and frequency (7 ± 2%) were increased 30–60 min post-AIH during d-NREM sleep. vLTF was significant but less robust during l-NREM sleep, was minimal during QW, and was not observed following acute sustained hypoxia or sham protocols in any vigilance state. Thus, vLTF is state-dependent and pattern-sensitive in unanesthetized Lewis rats, with the greatest effects during d-NREM sleep. Although the physiological significance of vLTF is not clear, its greatest significance to ventilatory control is most likely during sleep.
Neurotrophin-3 Is a Novel Angiogenic Factor Capable of Therapeutic Neovascularization in a Mouse Model of Limb Ischemia
Authors: Cristofaro Brunella , Stone Oliver A. , Caporali Andrea , Dawbarn David , Ieronimakis Nicholas , Reyes Morayma , Madeddu Paolo , Bates David O. , Emanueli Costanza
Published: April 2010

Objective—

To investigate the novel hypothesis that neurotrophin-3 (NT-3), an established neurotrophic factor that participates in embryonic heart development, promotes blood vessel growth.

Methods and Results—

We evaluated the proangiogenic capacity of recombinant NT-3 in vitro and of
NT-3
gene transfer in vivo (rat mesenteric angiogenesis assay and mouse normoperfused adductor muscle). Then, we studied whether either transgenic or endogenous NT-3 mediates postischemic neovascularization in a mouse model of limb ischemia. In vitro, NT-3 stimulated endothelial cell survival, proliferation, migration, and network formation on the basement membrane matrix Matrigel. In the mesenteric assay, NT-3 increased the number and size of functional vessels, including vessels covered with mural cells. Consistently, NT-3 overexpression increased muscular capillary and arteriolar densities in either the absence or the presence of ischemia and improved postischemic blood flow recovery in mouse hind limbs. NT-3-induced microvascular responses were accompanied by tropomyosin receptor kinase C (an NT-3 high-affinity receptor) phosphorylation and involved the phosphatidylinositol 3-kinase-Akt kinase-endothelial nitric oxide synthase pathway. Finally, endogenous NT-3 was shown to be essential in native postischemic neovascularization, as demonstrated by using a soluble tropomyosin receptor kinase C receptor domain that neutralizes NT-3.

Conclusion—

Our results provide the first insight into the proangiogenic capacity of NT-3 and propose NT-3 as a novel potential agent for the treatment of ischemic disease.
Atherosclerosis in Abdominal Aortic Aneurysms: A Causal Event or a Process Running in Parallel? The Tromsø Study
Authors: Johnsen Stein Harald , Forsdahl Signe Helene , Singh Kulbir , Jacobsen Bjarne Koster
Published: April 2010

Objective—

The pathogenesis of abdominal aortic aneurysm (AAA) formation is poorly understood. We investigated the relationship between carotid, femoral, and coronary atherosclerosis and abdominal aortic diameter, and whether atherosclerosis was a risk marker for AAA.

Methods and Results—

Ultrasound of the right carotid artery, the common femoral artery, and the abdominal aorta was performed in 6446 men and women from a general population. The burden of atherosclerosis was assessed as carotid total plaque area, common femoral lumen diameter, and self-reported coronary heart disease. An AAA was defined as maximal infrarenal aortic diameter ≥30 mm. No dose-response relationship was found between carotid atherosclerosis and abdominal aortic diameter <27 mm. However, significantly more atherosclerosis and coronary heart disease was found in aortic diameter ≥27 mm and in AAAs. The age- and sex-adjusted odds ratio (OR) (95% CI) for AAA in the top total plaque area quintile was 2.3 (1.5 to 3.4), as compared with subjects without plaques. The adjusted OR (95% CI) was 1.7 (1.1 to 2.6). No independent association was found between femoral lumen diameter and AAA.

Conclusion—

The lack of a consistent dose-response relationship between atherosclerosis and abdominal aortic diameter suggests that atherosclerosis may not be a causal event in AAA but develops in parallel with or secondary to aneurismal dilatation.
Glucose-Regulated Protein 78 and Platelet Deposition
Authors: Molins Blanca , Peña Esther , Padro Teresa , Casani Laura , Mendieta Carlos , Badimon Lina
Published: April 2010

Objective—

To investigate the effect of rosuvastatin on platelet deposition under controlled shear rate conditions and to identify new platelet proteins involved in the interaction with the activating substrate.

Methods and Results—

Platelet-vessel wall interaction and thrombosis take place under dynamic conditions involving the interaction of the exposed damaged vascular wall with the circulating blood cells and proteins. Blood was perfused over type I collagen at different wall shear rates, and platelet deposition was measured by confocal microscopy. Perfused effluent blood was collected, platelets were sequentially extracted based on differential protein solubility, and proteins were separated by 2D gel electrophoresis. Blockade of 3-hydroxy-3-methylglutaryl–coenzyme A reductase significantly reduced platelet deposition and modulated the expression pattern of 18 proteins in the platelet subproteome. Among them, an increase in platelet surface 78-kDa glucose-regulated protein (GRP78), a stress-inducible multifunctional endoplasmic reticulum protein, was clearly apparent. Immunoprecipitation of platelet GRP78 revealed its interaction with tissue factor. Moreover, blockade of surface GRP78 resulted in a substantial increase in platelet deposition and tissue factor procoagulant activity and in a decrease in clotting time.

Conclusion—

These findings demonstrate that blockade of 3-hydroxy-3-methylglutaryl–coenzyme A reductase reduces platelet deposition and inhibits GRP78 translocation from the platelet surface after shear and collagen activation. For the first time to our knowledge, this study reports on the presence and functional role of GRP78 in platelets and indicates that GRP78 has additional functions beyond those of a molecular chaperone.
Nerve Growth Factor Promotes Cardiac Repair following Myocardial Infarction
Authors: Meloni Marco , Caporali Andrea , Graiani Gallia , Lagrasta Costanza , Katare Rajesh , Van Linthout Sophie , Spillmann Frank , Campesi Ilaria , Madeddu Paolo , Quaini Federico , Emanueli Costanza
Published: April 2010

Rationale
:

Nerve growth factor (NGF) promotes angiogenesis and cardiomyocyte survival, which are both desirable for postinfarction myocardial healing. Nonetheless, the NGF potential for cardiac repair has never been investigated.

Objective
:

To define expression and localization of NGF and its high-affinity receptor TrkA (tropomyosin-related receptor A) in the human infarcted heart and to investigate the cardiac roles of both endogenous and engineered NGF using a mouse model of myocardial infarction (MI).

Methods and Results
:

Immunostaining for NGF and TrkA was performed on heart samples from humans deceased of MI or unrelated pathologies. To study the post-MI functions of endogenous NGF, a NGF-neutralizing antibody (Ab-NGF) or nonimmune IgG (control) was given to MI mice. To investigate the NGF therapeutic potential, human
NGF
gene or control (empty vector) was delivered to the murine periinfarct myocardium. Results indicate that NGF is present in the infarcted human heart. Both cardiomyocytes and endothelial cells (ECs) possess TrkA, which suggests NGF cardiovascular actions in humans. In MI mice, Ab-NGF abrogated native reparative angiogenesis, increased EC and cardiomyocyte apoptosis and worsened cardiac function. Conversely,
NGF
gene transfer ameliorated EC and cardiomyocyte survival, promoted neovascularization and improved myocardial blood flow and cardiac function. The prosurvival/proangiogenic Akt/Foxo pathway mediated the therapeutic benefits of
NGF
transfer. Moreover,
NGF
overexpression increased stem cell factor (the c-kit receptor ligand) expression, which translated in higher myocardial abundance of c-kit
pos
progenitor cells in
NGF
-engineered hearts.

Conclusions
:

NGF elicits pleiotropic beneficial actions in the post-MI heart. NGF should be considered as a candidate for therapeutic cardiac regeneration.
Opposing Effects of Apolipoprotein M on Catabolism of Apolipoprotein B–Containing Lipoproteins and Atherosclerosis
Authors: Christoffersen Christina , Pedersen Tanja Xenia , Gordts Philip L.S.M. , Roebroek Anton J.M. , Dahlbäck Björn , Nielsen Lars Bo
Published: April 2010

Rationale
:

Plasma apolipoprotein (apo)M is mainly associated with high-density lipoprotein (HDL). HDL-bound apoM is antiatherogenic in vitro. However, plasma apoM is not associated with coronary heart disease in humans, perhaps because of a positive correlation with plasma low-density lipoprotein (LDL).

Objective
:

We explored putative links between apoM and very-low-density (VLDL)/LDL metabolism and the antiatherogenic potential of apoM in vivo.

Methods and Results
:

Plasma apoM was increased ≈2.1 and ≈1.5 fold in mice lacking LDL receptors (
Ldlr
−/−
) and expressing dysfunctional LDL receptor–related protein 1 (
Lrp1
n2/n2
), respectively, but was unaffected in apoE-deficient (
ApoE
−/−
) mice. Thus, pathways controlling catabolism of VLDL and LDL affect plasma apoM. Overexpression (≈10-fold) of human apoM increased (50% to 70%) and apoM deficiency decreased (≈25%) plasma VLDL/LDL cholesterol in
Ldlr
−/−
mice, whereas apoM did not affect plasma VLDL/LDL in mice with intact LDL receptors. Moreover, plasma clearance of apoM-enriched VLDL/LDL was slower than that of control VLDL/LDL in mice lacking functional LDL receptors and LRP1, suggesting that apoM impairs the catabolism of VLDL/LDL that occurs independently of the LDL receptor and LRP1. ApoM overexpression decreased atherosclerosis in
ApoE
−/−
(60%) and cholate/cholesterol-fed wild-type mice (70%). However, in
Ldlr
−/−
mice the antiatherogenic effect of apoM was attenuated by its VLDL/LDL-raising effect.

Conclusion
:

The data suggest that defect LDL receptor function leads to increased plasma apoM concentrations, which in turn, impairs the removal of VLDL/LDL from plasma. This mechanism opposes the otherwise antiatherogenic effect of apoM.
Glycogen Synthase Kinase-3β Regulates Post–Myocardial Infarction Remodeling and Stress-Induced Cardiomyocyte Proliferation In Vivo
Authors: Woulfe Kathleen C. , Gao Erhe , Lal Hind , Harris David , Fan Qian , Vagnozzi Ronald , DeCaul Morgan , Shang Xiying , Patel Satish , Woodgett James R. , Force Thomas , Zhou Jibin
Published: April 2010

Rationale
:

Numerous studies have proposed that glycogen synthase kinase (GSK)-3β is a central regulator of the hypertrophic response of cardiomyocytes. However, all of this work has relied on overexpression of GSK-3β, expression of constitutively active mutants, or small molecule inhibitors with documented off-target effects. Genetic loss of function approaches have not been used in the adult mouse because germ-line deletion of GSK-3β is embryonic-lethal.

Objective
:

This study was designed to define the role played by GSK-3β in pressure overload (PO)-induced hypertrophy and remodeling following myocardial infarction (MI).

Methods and Results
:

We used a mouse model that allows inducible, cardiomyocyte-specific deletion of GSK-3β in the adult knockout. Surprisingly, we find that knockout mice exposed to PO induced by thoracic aortic constriction exhibit a normal hypertrophic response. Thus, in contrast to virtually all prior published studies, GSK-3β appears to play at most a minor role in the hypertrophic response to PO stress. However, GSK-3β does regulate post-MI remodeling because the GSK-3β knockouts had less left ventricular dilatation and better-preserved left ventricular function at up to 8 weeks post-MI despite demonstrating significantly more hypertrophy in the remote myocardium. Deletion of GSK-3β also led to increased cardiomyocyte proliferation following PO and MI.

Conclusions
:

Deletion of GSK-3β protects against post-MI remodeling and promotes stress-induced cardiomyocyte proliferation in the adult heart. These studies suggest that inhibition of GSK-3β could be a strategy to both prevent remodeling and to promote cardiac regeneration in pathological states.
Regulation of Cardiomyocyte Polyploidy and Multinucleation by CyclinG1
Authors: Liu Zhipei , Yue Shijing , Chen Xiaobo , Kubin Thomas , Braun Thomas
Published: April 2010

Rationale
:

Polyploidy and multinucleation are characteristic features of mammalian cardiomyocytes, which develop shortly after birth when most differentiated cardiomyocytes become acytokinetic. Cardiac overload and hypertrophy further increase the degree of polyploidy of cardiomyocytes, suggesting a role in cell type–specific responses to physiological and pathological stimuli.

Objective
:

We sought to study the function of cyclinG1 in the regulation of polyploidy and multinucleation in cardiomyocytes.

Methods and Results
:

We found that expression of cyclinG1, a transcriptional target of p53, coincides with arrest of cardiomyocyte proliferation and onset of polyploidization. Overexpression of cyclinG1 promoted DNA synthesis but inhibited cytokinesis in neonatal cardiomyocytes leading to an enlarged population of binuclear cardiomyocytes. Reciprocally, inactivation of the cyclinG1 gene in mice lowered the degree of polyploidy and multinucleation in cardiomyocytes. Moreover, lack of cyclinG1 prevented the increase of polynucleated cardiomyocytes in response to pressure overload and hypertrophy.

Conclusions
:

CyclinG1 is an important player for the regulation of polyploidy and multinucleation in cardiomyocytes probably by inhibition of apoptosis caused by checkpoint activation.
TRB3 Function in Cardiac Endoplasmic Reticulum Stress
Authors: Avery Joan , Etzion Sharon , DeBosch Brian J. , Jin Xiaohua , Lupu Traian S. , Beitinjaneh Bassel , Grand Jacob , Kovacs Attila , Sambandam Nandakumar , Muslin Anthony J.
Published: April 2010

Rationale
:

Tribbles (TRB)3 is an intracellular pseudokinase that modulates the activity of several signal transduction cascades. TRB3 has been reported to inhibit the activity of Akt protein kinases. TRB3 gene expression is highly regulated in many cell types, and amino acid starvation, hypoxia, or endoplasmic reticulum (ER) stress promotes TRB3 expression in noncardiac cells.

Objective
:

The objective of this work was to examine TRB3 expression and function in cultured cardiac myocytes and in mouse heart.

Methods and Results
:

Agents that induced ER stress increased TRB3 expression in cultured cardiac myocytes while blocking insulin-stimulated Akt activation in these cells. Knockdown of TRB3 in cultured cardiac myocytes reversed the effects of ER stress on insulin signaling. Experimental myocardial infarction led to increased TRB3 expression in murine heart tissue in the infarct border zone suggesting that ER stress may play a role in pathological cardiac remodeling. Transgenic mice with cardiac-specific overexpression of TRB3 were generated and they exhibited normal contractile function but altered cardiac signal transduction and metabolism with reduced cardiac glucose oxidation rates. Transgenic TRB3 mice were also sensitized to infarct expansion and cardiac myocyte apoptosis in the infarct border zone after myocardial infarction.

Conclusions
:

These results demonstrate that TRB3 induction is a significant aspect of the ER stress response in cardiac myocytes and that TRB3 antagonizes cardiac glucose metabolism and cardiac myocyte survival.
Manipulation of Death Pathways in Desmin-Related Cardiomyopathy
Authors: Maloyan Alina , Sayegh Jennifer , Osinska Hanna , Chua Balvin H.L. , Robbins Jeffrey
Published: April 2010

Rationale
:

Transgenic mice with cardiac specific overexpression of mutated αB-crystallin (CryAB
R120G
) display Desmin-related myopathy (DRM) with dilated cardiomyopathy and heart failure. Our previous studies showed the presence of progressive mitochondrial abnormalities and activation of apoptotic cell death in CryAB
R120G
transgenic hearts. However, the role of mitochondrial dysfunction and apoptosis in the overall course of the disease was unclear.

Objective
:

We tested the hypothesis that prevention of apoptosis would ameliorate CryAB
R120G
pathology and decrease morbidity.

Methods and Results
:

We crossed CryAB
R120G
mice to transgenic mice with cardiac specific overexpression of Bcl-2. Sustained Bcl-2 overexpression in CryAB
R120G
hearts prolonged CryAB
R120G
transgenic mice survival by 20%. This was associated with decreased mitochondrial abnormalities, restoration of cardiac function, prevention of cardiac hypertrophy, and attenuation of apoptosis. CryAB
R120G
misfolded protein aggregation was significantly reduced in the double transgenic. However, inhibition of apoptotic signaling resulted in the upregulation of autophagy and alternative death pathways, the net result being increased necrosis.

Conclusion
:

Although Bcl-2 overexpression prolonged life in this DRM model, in the absence of apoptosis, another death pathway was activated.
Lysophosphatidic Acid Receptors LPA1and LPA3Promote CXCL12-Mediated Smooth Muscle Progenitor Cell Recruitment in Neointima Formation
Authors: Subramanian Pallavi , Karshovska Ela , Reinhard Patricia , Megens Remco T.A. , Zhou Zhe , Akhtar Shamima , Schumann Uwe , Li Xiaofeng , van Zandvoort Marc , Ludin Christian , Weber Christian , Schober Andreas
Published: April 2010

Rationale:The chemokine CXCL12 (CXC motif ligand 12) and its receptor CXCR 4 (CXC motif receptor 4) direct the recruitment of smooth muscle progenitor cells (SPCs) in neointima formation after vascular injury. Lysophosphatidic acid (LPA) induces CXCL12 and neointimal accumulation of smooth muscle cells (SMCs) in uninjured arteries. Thus, we hypothesize that LPA may regulate CXCL12-mediated vascular remodelling.

Objectives:We evaluated the role of LPA receptors in initiating CXCL12-dependent vascular repair by SPCs.

Methods and Results:Wire-induced carotid injury was performed in apolipoprotein E−/−mice on western-type diet. LPA receptor expression was studied by immunostaining and quantitative RT-PCR. LPA receptors LPA1and LPA3were detected in the media of uninjured arteries and in the injury-induced neointima. LPA3mRNA was upregulated and LPA1mRNA downregulated at one week after injury. The LPA1/3antagonist Ki16425 inhibited neointima formation by 71% and reduced both relative neointimal SMCs and the macrophage content. Additionally, neointimal hypoxia-inducible factor-1α and CXCL12 expression, the injury-induced peripheral stem cell antigen-1 (Sca-1)+/Lin−SPC mobilization, and the neointimal recruitment of Sca-1+SMCs were inhibited by Ki16425. In wild type mice, LPA20:4 increased CXCL12 and hypoxia-inducible factor-1α expression in carotid arteries as early as 1 day following short-term endoluminal incubation. LPA20:4-induced SPC mobilization and neointima formation were blocked by Ki16425, LPA1- and LPA3-specific small interfering (si)RNA, and the CXCR4 antagonist POL5551. Ki16425 reduced LPA20:4-mediated neointimal recruitment of SPC as demonstrated by 2-photon microscopy in bone marrow chimeric mice after repopulation with SM22-LacZ transgenic, hematopoietic cells. Moreover, POL5551 decreased the neointimal accumulation of CXCR4+SMCs.

Conclusions:LPA1and LPA3promote neointima formation through activation of CXCL12-mediated mobilization and recruitment of SPCs.
Essential Roles of an Intercalated Disc Protein, mXinβ, in Postnatal Heart Growth and Survival
Authors: Wang Qinchuan , Lin Jenny Li-Chun , Reinking Benjamin E. , Feng Han-Zhong , Chan Fu-Chi , Lin Cheng-I. , Jin Jian-Ping , Gustafson-Wagner Elisabeth A. , Scholz Thomas D. , Yang Baoli , Lin Jim Jung-Ching
Published: April 2010

Rationale
:

The Xin repeat–containing proteins mXinα and mXinβ localize to the intercalated disc of mouse heart and are implicated in cardiac development and function. The mXinα directly interacts with β-catenin, p120-catenin, and actin filaments. Ablation of
mXin
α results in adult late-onset cardiomyopathy with conduction defects. An upregulation of the mXinβ in mXinα-deficient hearts suggests a partial compensation.

Objective
:

The essential roles of mXinβ in cardiac development and intercalated disc maturation were investigated.

Methods and Results
:

Ablation of
mXin
β led to abnormal heart shape, ventricular septal defects, severe growth retardation, and postnatal lethality with no upregulation of the mXinα. Postnatal upregulation of mXinβ in wild-type hearts, as well as altered apoptosis and proliferation in
mXin
β-null hearts, suggests that mXinβ is required for postnatal heart remodeling. The
mXin
β-null hearts exhibited a misorganized myocardium as detected by histological and electron microscopic studies and an impaired diastolic function, as suggested by echocardiography and a delay in switching off the slow skeletal troponin I. Loss of mXinβ resulted in the failure of forming mature intercalated discs and the mislocalization of mXinα and N-cadherin. The
mXin
β-null hearts showed upregulation of active Stat3 (signal transducer and activator of transcription 3) and downregulation of the activities of Rac1, insulin-like growth factor 1 receptor, protein kinase B, and extracellular signal-regulated kinases 1 and 2.

Conclusions
:

These findings identify not only an essential role of mXinβ in the intercalated disc maturation but also mechanisms of mXinβ modulating N-cadherin–mediated adhesion signaling and its crosstalk signaling for postnatal heart growth and animal survival.
The Constitutive Function of Native TRPC3 Channels Modulates Vascular Cell Adhesion Molecule-1 Expression in Coronary Endothelial Cells Through Nuclear Factor κB Signaling
Authors: Smedlund Kathryn , Tano Jean-Yves , Vazquez Guillermo
Published: April 2010

Rationale
:

Upregulation of endothelial vascular cell adhesion molecule (VCAM)-1 and the subsequent increase in monocyte recruitment constitute critical events in atherogenesis. We have recently shown that in human coronary artery endothelial cells (HCAECs) regulated expression of VCAM-1 depends, to a significant extent, on expression and function of the Ca
2+
-permeable channel transient receptor potential canonical (TRPC)3, regardless of the ability of the stimulatory signal to induce regulated Ca
2+
influx, leading to the hypothesis that TRPC3 constitutive, rather than regulated function, contributes to the underlying signaling mechanism.

Objective
:

The present studies addressed this important question and gathered mechanistic insight on the signaling coupling constitutive TRPC3 function to VCAM-1 expression.

Methods and Results
:

In HCAECs, maneuvers that prevent Ca
2+
influx or knockdown of TRPC3 markedly reduced tumor necrosis factor (TNF)α-induced VCAM-1 and monocyte adhesion. TNFα also induced TRPC3 expression and TRPC3-mediated constitutive cation influx and currents. Stable (HEK293 cells) or transient (HCAECs) overexpression of TRPC3 enhanced TNFα-induced VCAM-1 compared to wild-type cells. IκBα phosphorylation/degradation was reduced by TRPC3 knockdown and increased by channel overexpression. Inhibition of calmodulin completely prevented nuclear factor κB activation, whereas blocking calmodulin-dependent kinases or NADPH oxidases rendered partial inhibition.

Conclusions
:

Our findings indicate that in HCAECs expression of VCAM-1 and monocyte adhesion depend, to a significant extent, on TRPC3 constitutive function through a signaling mechanism that requires constitutive TRPC3-mediated Ca
2+
influx for proper activation of nuclear factor κB, presumably through Ca
2+
-dependent activation of the calmodulin/calmodulin-dependent kinase axis.
Nox4 is a Novel Inducible Source of Reactive Oxygen Species in Monocytes and Macrophages and Mediates Oxidized Low Density Lipoprotein–Induced Macrophage Death
Authors: Lee Chi Fung , Qiao Mu , Schröder Katrin , Zhao Qingwei , Asmis Reto
Published: April 2010

Rationale
:

The enhanced formation of intracellular reactive oxygen species (ROS) induced by oxidized low-density lipoprotein (OxLDL) promotes macrophage death, a process likely to contribute to the formation of necrotic cores and the progression of atherosclerotic lesions. Yet macrophage deficiency of phagocytic NADPH oxidase (Nox2), the primary source of ROS in macrophages, does not reduce atherosclerotic lesion development in mice. This suggests an as yet unidentified NADPH oxidase may be present in macrophages and responsible for the intracellular ROS formation induced by OxLDL.

Objective
:

The aim of this study was to identify the source of intracellular ROS involved in macrophage death.

Methods and Results
:

Nox4 was expressed in human monocytes and mature macrophages, and was localized to the endoplasmic reticulum and to defined foci within the nucleus. Nox4 colocalized with p22
phox
, and both proteins were upregulated in response to OxLDL stimulation, whereas Nox2/gp91
phox
levels remained unchanged. Induction of Nox4 expression, intracellular ROS formation and macrophage cytotoxicity induced by OxLDL were blocked by MEK1/2 inhibition, but not by inhibitors of p38-MAPK (mitogen-activated protein kinase), JNK (Jun N-terminal kinase), or JAK2 (Janus kinase 2). Small interfering RNA knockdown of Nox4 inhibited both intracellular ROS production and macrophage cytotoxicity induced by OxLDL, whereas Nox4 overexpression enhanced both OxLDL-stimulated ROS formation and macrophage death.

Conclusions
:

Nox4 is a novel source of intracellular ROS in human monocytes and macrophages. Induction of Nox4 by OxLDL is mediated by the MEK1/ERK pathway and required for OxLDL cytotoxicity in human macrophages, implicating monocytic Nox4 in atherogenesis.