bluuebunny/crossref_metadata_2025 huggingface dataset:
Vascular inflammation with eosinophils after the use of n-butyl cyanoacrylate liquid embolic system
Authors: Quinn John C , Mittal Neelesh , Baisre Ada , Cho Eun-Sook , Sharer Leroy R , Gandhi Chirag , Prestigiacomo Charles J
Published: December 2010

Objective and importance

Currently, n-butyl cyanoacrylate (n-BCA) is one of the most widely used liquid embolic agents in the treatment of intracranial arteriovenous malformations (AVMs). The cases of three patients are reported who underwent endovascular embolization with n-BCA, followed by resection in two and post-embolization hemorrhage with emergent evacuation in one, with histologic demonstration of an eosinophilic vasculitis found in resected AVM specimens. This is probably the first report of this tissue reaction, which may have theoretically serious clinical implications.

Clinical presentation

In this series, three patients (2 women, 1 man) presented with intracranial AVMs (Spetzler–Martin I–III) with the lesions located in the frontal lobe in two of the patients and in the parietal lobe in one. All patients presented with headache, and one also had new-onset seizures.

Intervention

All patients underwent embolization with n-BCA before a planned, staged surgical resection of the embolized AVMs. One patient had four embolizations over a 5-month period, one had three embolizations over 3 months complicated by hemorrhage after embolization requiring emergent evacuation of the hematoma, and the third patient had a single embolization. In all three patients, surgical and autopsy specimens showed an inflammatory response within the embolized vasculature with a prominent eosinophilic infiltrate.

Conclusion

The eosinophilic vasculitis seen in the pathology specimens may represent a previously undocumented hypersensitivity reaction following exposure to n-BCA, with the potential for adverse sequelae, including increased risk of hemorrhage as was seen in one of our patients.
Role of connexins in microvascular dysfunction during inflammation
Authors: Tyml Karel
Published: December 2010

In arterioles, a locally initiated diameter change can propagate rapidly along the vessel length (arteriolar conducted response), thus contributing to arteriolar hemodynamic resistance. The response is underpinned by electrical coupling along the arteriolar endothelial layer. Connexins (Cx; constituents of gap junctions) are required for this coupling. This review addresses the effect of acute systemic inflammation (sepsis) on arteriolar conduction and interendothelial electrical coupling. Lipopolysaccharide (LPS; an initiating factor in sepsis) and polymicrobial sepsis (24 h model) attenuate conducted vasoconstriction in mice. In cultured microvascular endothelial cells harvested from rat and mouse skeletal muscle, LPS reduces both conducted hyperpolarization–depolarization along capillary-like structures and electrical coupling along confluent cell monolayers. LPS also tyrosine-phosphorylates Cx43 and serine-dephosphorylates Cx40. Since LPS-reduced coupling is Cx40- but not Cx43-dependent, only Cx40 dephosphorylation may be consequential. Nitric oxide (NO) overproduction is critical in advanced sepsis, since the removal of this overproduction prevents the attenuated conduction. Consistently, (i) exogenous NO in cultured cells reduces coupling in a Cx37-dependent manner, and (ii) the septic microvasculature in vivo shows no Cx40 phenotype. A complex role emerges for endothelial connexins in sepsis. Initially, LPS may reduce interendothelial coupling and arteriolar conduction by targeting Cx40, whereas NO overproduction in advanced sepsis reduces coupling and conduction by targeting Cx37 instead.
Cytotoxic activity of nemorosone in human MCF-7 breast cancer cells
Authors: Popolo Ada , Piccinelli Anna Lisa , Morello Silvana , Sorrentino Rosalinda , Osmany Cuesta Rubio , Rastrelli Luca , Aldo Pinto
Published: December 2010

Estrogen receptor (ER) antagonists have been widely used for breast cancer treatment; however, patients have increasingly shown resistance and sensitivity to the high toxicity of these drugs, and identification of novel targeted therapies is therefore required. To determine whether nemorosone, a polycyclic polyisoprenylated benzophenone isolated from floral resins of Clusia rosea Jacq. and Cuban propolis samples, exerts anticancer effects on human breast cancer cells, estrogen receptor positive (ERα+) MCF-7 and estrogen receptor negative (ERα–) MDA-MB-231 and LNCaP cells were used. Cells were treated with nemorosone alone or in association with 17β-estradiol (E2) or an ER antagonist, ICI 182,780, a selective ER downregulator that completely abrogates estrogen-sensitive gene transcription. Nemorosone inhibited the cell viability of ERα+ but not of ERα– cells. In MCF-7, nemorosone induced inhibition of cell growth by blocking the cell cycle in the G0/G1phase. Moreover, the expression of pERK1/2 and pAkt, considered to be hallmarks of the nongenomic estrogen signalling pathway, were reduced in MCF-7 cells treated with nemorosone. All these effects were enhanced by ICI 182,780. However, nemorosone was not able to interfere with E2-induced Ca2+release. These findings suggest that nemorosone may have therapeutic application in the treatment of breast cancer because of its activity on ERα.
Feeding blueberry diets inhibits angiotensin II-converting enzyme (ACE) activity in spontaneously hypertensive stroke-prone rats
Authors: Wiseman Waylon , Egan Jennifer M. , Slemmer Jennifer E. , Shaughnessy Kevin S. , Ballem Katherine , Gottschall-Pass Katherine T. , Sweeney Marva I.
Published: December 2010

Feeding flavonoid-rich blueberries to spontaneously hypertensive stroke-prone rats (SHRSP) lowers blood pressure. To determine whether this is due to inhibition of angiotensin-converting enzyme (ACE) activity, as seen with other flavanoid-rich foods, we fed blueberries to SHRSP and normotensive rats and analyzed ACE activity in blood and tissues. After 2 weeks on a control diet, the hypertensive rats showed 56% higher levels of ACE activity in blood as compared with the normotensive rats (p < 0.05). Feeding a 3% blueberry diet for 2 weeks lowered ACE activity in the SHRSP (p < 0.05) but not the normotensive rats. ACE activity in plasma of SHRSP was no longer elevated at weeks 4 and 6, but blueberry feeding inhibited ACE in SHRSP after 6 weeks. Blueberry diets had no effect on ACE activity in lung, testis, kidney, or aorta. Our results suggest that dietary blueberries may be effective in managing early stages of hypertension, partially due to an inhibition of soluble ACE activity.
Coagulation activation in an experimental pneumonia model in malnourished mice
Authors: Zelaya Hortensia , Haro Cecilia , Laiño Jonathan , Alvarez Susana , Agüero Graciela
Published: December 2010

Malnutrition induces a decrease in immunity that affects the ability of the organism to deal with an infectious challenge. The clotting system is considered a branch of immunity and its activation is important in the pathogenesis of an infectious disease. This work was conducted to determine coagulation modifications in malnourished hosts before and during infection. Weaned mice were malnourished via a protein-free diet. Well-nourished control mice (WNC) consumed a balanced conventional diet. Malnourished mice (MN) and WNC were challenged intranasally with Streptococcus pneumoniae . Blood, bronchoalveolar lavages (BAL), and lung samples were taken at different times post infection. The results were that MN showed altered hemostatic tests and fibrin(ogen) deposits in the lung. Thus, an increase in thrombin–antithrombin complexes (TATc) in plasma and BAL was observed. In the MN group, infection induced a rise in TATc in plasma and BAL and increased plasma fibrinogen and fibrin(ogen) deposits in the lung. A decrease in activated protein C and antithrombin in BAL and an early decrease followed by an increase in plasma Factor VIII were also observed. Thus, malnourishment induced a procoagulant state increased by infection. This is the first work that presents results of an exhaustive study of coagulation in malnourished hosts before and during an infection.
The role of estrogen and progesterone, administered alone and in combination, in modulating cytokine concentration following traumatic brain injury
Authors: Khaksari Mohammad , Soltani Zahra , Shahrokhi Nader , Moshtaghi Gholamreza , Asadikaram Gholamreza
Published: December 2010

Cytokines play an important role in the pathophysiology of traumatic brain injury (TBI). This study was designed to determine the effects of administering progesterone (P) and estrogen (E), alone and in combination, on brain water content, blood–brain barrier (BBB) disturbance, and brain level of cytokines following diffuse TBI. Ovariectomized rats were divided into 9 groups, treated with vehicle, E1, E2, P1, P2, E1+P1, E1+P2, E2+P1, and E2+P2. Levels of BBB disruption (5 h), cytokines, and water content (24 h) were evaluated after TBI induced by the Marmarou method. Physiological (E1 and P1) and pharmacological (E2 and P2) doses of estrogen and progesterone were administered 30 min after TBI. Water content in the E1+P2-treated group was higher than in the E1-treated group. The inhibitory effect of E2 on water content was reduced by adding progesterone. The inhibitory effect of E1 and E2 on Evans blue content was reduced by treatment with E1+P1 and E2+P2, respectively. The brain level of IL-1β was reduced in E1 and E2, after TBI. In the E2+P2-treated group, this level was higher than in the E2-treated group. The brain level of TGF-β was also elevated by the administration of progesterone and estrogen alone, and reduced when the hormones were administered in combination. In conclusion, a combined administration of progesterone and estrogen inhibited the decreasing effects of administration of progesterone and estrogen alone on water content and BBB disruption that mediated to change the proinflammatory cytokines.
Cree antidiabetic plant extracts display mechanism-based inactivation of CYP3A4
Authors: Tam Teresa W. , Liu Rui , Arnason John T. , Krantis Anthony , Staines William A. , Haddad Pierre S. , Foster Brian C.
Published: December 2010

Seventeen Cree antidiabetic medicinal plants were studied to determine their potential to inhibit cytochrome P450 3A4 (CYP3A4) through mechanism-based inactivation (MBI). The ethanolic extracts of the medicinal plants were studied for their inhibition of CYP3A4 using the substrates testosterone and dibenzylfluorescein (DBF) in high pressure liquid chromatography (HPLC) and microtiter fluorometric assays, respectively. Using testosterone as a substrate, extracts of Alnus incana , Sarracenia purpurea , and Lycopodium clavatum were identified as potent CYP3A4 MBIs, while those from Abies balsamea , Picea mariana , Pinus banksiana , Rhododendron tomentosum , Kalmia angustifolia , and Picea glauca were identified as less potent inactivators. Not unexpectedly, the other substrate, DBF, showed a different profile of inhibition. Only A. balsamea was identified as a CYP3A4 MBI using DBF. Abies balsamea displayed both NADPH- and time-dependence of CYP3A4 inhibition using both substrates. Overall, several of the medicinal plants may markedly deplete CYP3A4 through MBI and, consequently, decrease the metabolism of CYP3A4 substrates including numerous medications used by diabetics.
Role of large-conductance Ca2+-activated K+ channels in adenosine A1 receptor-mediated pharmacological postconditioning in H9c2 cells
Authors: Fretwell Laurice , Dickenson John M.
Published: December 2010

Ischaemic postconditioning is a phenomenon whereby short periods of ischaemia applied during the start of reperfusion protect the myocardium from the damaging consequences of reperfusion. As such, pharmacological-induced postconditioning represents an attractive therapeutic strategy for reducing reperfusion injury during cardiac surgery and following myocardial infarction. The primary aim of this study was to determine the role of large-conductance Ca2+-activated potassium channels (BKCa channels) in adenosine A1 receptor-induced pharmacological postconditioning in the rat embryonic cardiomyoblast-derived cell line H9c2. H9c2 cells were exposed to 6 h hypoxia (0.5% O2) followed by 18 h reoxygenation (H/R) after which cell viability was assessed by monitoring lactate dehydrogenase (LDH) release and caspase-3 activation. The adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA; 100 nmol/L) or the BKCa channel opener NS1619 (10 µmol/L) were added for 30 min at the start of reoxygenation following 6 h hypoxic exposure. Where appropriate, cells were treated (15 min) before pharmacological postconditioning with the BKCa channel blockers paxilline (1 µmol/L) or iberiotoxin (100 nmol/L). Pharmacological postconditioning with CPA or NS1619 significantly reduced H/R-induced LDH release. Treatment with paxilline or iberiotoxin attenuated adenosine A1 receptor and NS1619-induced pharmacological postconditioning. These results have shown for the first time that BKCa channels are involved in adenosine A1 receptor-induced pharmacological postconditioning in a cell model system.
Long-term swimming exercise does not modulate the Akt-dependent endothelial nitric oxide synthase phosphorylation in healthy mice
Authors: Pellegrin Maxime , Miguet-Alfonsi Carole , Berthelot Alain , Mazzolai Lucia , Laurant Pascal
Published: December 2010

Molecular mechanisms by which exercise exerts cardiovascular benefits are poorly understood. Exercise-induced increase of endothelial NO synthase (eNOS) phosphorylation through the protein kinase Akt has been shown to be a key mechanism underlying the beneficial effect of exercise in coronary artery disease patients. We examined whether this protective pathway might also be activated in long-term-exercised healthy mice. C57BL/6 wild-type mice swam for 24 weeks. A group of sedentary animals were used as controls. Aortic levels of total protein kinase Akt (protein kinase B), phosphorylated Akt at ser473 (p-Akt), total eNOS, phosphorylated eNOS at Ser1177 (p-eNOS), and PECAM-1 (platelet endothelial cell adhesion molecule-1) were assessed by Western blotting. Protein expressions of Akt, p-Akt, eNOS, p-eNOS, and PECAM-1 were not modulated by 24 weeks of exercise. The Akt-dependent eNOS phosphorylation did not seem to be a primary molecular adaptation in response to long-term exercise in healthy mice.
NORMAL ELEMENTS OF COMPLETED GROUP ALGEBRAS OVER SLn(ℤp)
Authors: WEI FENG , BIAN DA
Published: December 2010

By a purely computational approach we prove that each nonzero normal element of a completed group algebra over the special linear group SL n(ℤp) is a unit.
COXETER COVERS OF THE CLASSICAL COXETER GROUPS
Authors: AMRAM MEIRAV , SHWARTZ ROBERT , TEICHER MINA
Published: December 2010

Let C(T) be a generalized Coxeter group, which has a natural map onto one of the classical Coxeter groups, either Bn or Dn. Let CY(T) be a natural quotient of C(T), and if C(T) is simply-laced (which means all the relations between the generators has order 2 or 3), CY(T) is a generalized Coxeter group, too. Let At,n be a group which contains t Abelian groups generated by n elements. The main result in this paper is that CY(T) is isomorphic to At,n ⋊ Bn or At,n ⋊ Dn, depends on whether the signed graph T contains loops or not, or in other words C(T) is simply-laced or not, and t is the number of the cycles in T. This result extends the results of Rowen, Teicher and Vishne to generalized Coxeter groups which have a natural map onto one of the classical Coxeter groups.
THE MINADEPT CLUSTERING APPROACH FOR DISCOVERING REFERENCE PROCESS MODELS OUT OF PROCESS VARIANTS
Authors: LI CHEN , REICHERT MANFRED , WOMBACHER ANDREAS
Published: December 2010

During the last years a new generation of adaptive Process-Aware Information Systems (PAIS) has emerged, which enables dynamic process changes at runtime, while preserving PAIS robustness and consistency. Such adaptive PAIS allow authorized users to add new process activities, to delete existing activities, or to change pre-defined activity sequences during runtime. Both this runtime flexibility and process configurations at build-time, lead to a large number of process variants being derived from the same process model, but slightly differing in structure due to the applied changes. Generally, process variants are expensive to configure and difficult to maintain. This paper presents selected results from our MinAdept project. In particular, we provide a clustering algorithm that fosters learning from past process changes by mining a collection of process variants. As mining result we obtain a process model for which average distance to the process variant models becomes minimal. By adopting this process model as reference model in the PAIS, need for future process configuration and adaptation decreases. We have validated our clustering algorithm by means of a case study as well as comprehensive simulations. Altogether, our vision is to enable full process lifecycle support in adaptive PAIS.
STRATEGIES FOR REDUCING INTER-DOMAIN PRESENCE TRAFFIC: AN ANALYTICAL STUDY
Authors: BELTRAN VICTORIA , PARADELLS JOSEP
Published: December 2010

Presence information was the key enabler to the great success of instant messaging applications. First, this information was limited to simple binary states such as online, offline or busy. However, this is, currently, evolving towards a much more generic, flexible concept to include all context that allows users or applications to adapt and control communications in a more efficient and personalized manner. Presence paves the way for the deployment of advanced communication services and is therefore a key component in the Next-Generation Networks (NGNs). These networks aim to unify fixed and mobile networks in order to provide users with global connectivity to always-on multimedia services. The main barrier to the implantation of next-generation presence-based services is the great amount of traffic involved in the distribution of presence information across domains. We study two strategies described in IETF drafts and one novel solution for reducing inter-domain presence traffic. We present the analytical formulas that calculate the traffic for the three strategies. Building on the analytical results, we analyze the factors that have impact on these strategies and study the suitability of each one under different conditions.
EMBEDDED HYPERSURFACES WITH CONSTANT mTH MEAN CURVATURE IN A UNIT SPHERE
Authors: WEI GUOXIN , CHENG QING-MING , LI HAIZHONG
Published: December 2010

In this paper, we study n-dimensional hypersurfaces with constant mth mean curvature in a unit sphere Sn+1(1) and construct many compact nontrivial embedded hypersurfaces with constant mth mean curvature Hm > 0 in Sn+1(1), for 1 ≤ m ≤ n-1. Moreover, if the 2nd mean curvature H2 takes value between [Formula: see text] and [Formula: see text] for any integer k ≥ 2 and n ≥ 3, then there exists an n-dimensional compact nontrivial embedded hypersurface with constant H2 (i.e. constant scalar curvature) in Sn+1(1); If the 4th mean curvature H4 takes value between [Formula: see text] and [Formula: see text] for any integer k ≥ 3 and n ≥ 5, then there exists an n-dimensional compact nontrivial embedded hypersurface with constant H4 in Sn+1(1).
SPECTRAL ESTIMATES FOR A NONHOMOGENEOUS DIFFERENCE PROBLEM
Authors: KRISTÁLY ALEXANDRU , MIHĂILESCU MIHAI , RĂDULESCU VICENŢIU , TERSIAN STEPAN
Published: December 2010

We study an eigenvalue problem in the framework of difference equations. We show that there exist two positive constants λ0and λ1verifying λ0≤ λ1such that any λ ∈ (0, λ0) is not an eigenvalue of the problem, while any λ ∈ [λ1, ∞) is an eigenvalue of the problem. Some estimates for λ0and λ1are also given.
INTEGRAL SOLUTIONS TO A CLASS OF NONLOCAL EVOLUTION EQUATIONS
Authors: GARCÍA-FALSET JESÚS , REICH SIMEON
Published: December 2010

We study the existence of integral solutions to a class of nonlinear evolution equations of the form [Formula: see text] where A : D(A) ⊆ X → 2X is an m-accretive operator on a Banach space X, and f : [0, T] × X → X and [Formula: see text] are given functions. We obtain sufficient conditions for this problem to have a unique integral solution.
Amino acids stimulate cholecystokinin release through the Ca2+-sensing receptor
Authors: Wang Yu , Chandra Rashmi , Samsa Leigh Ann , Gooch Barry , Fee Brian E. , Cook J. Michael , Vigna Steven R. , Grant Augustus O. , Liddle Rodger A.
Published: December 2010

Cholecystokinin (CCK) is produced by discrete endocrine cells in the proximal small intestine and is released following the ingestion of food. CCK is the primary hormone responsible for gallbladder contraction and has potent effects on pancreatic secretion, gastric emptying, and satiety. In addition to fats, digested proteins and aromatic amino acids are major stimulants of CCK release. However, the cellular mechanism by which amino acids affect CCK secretion is unknown. The Ca2+-sensing receptor (CaSR) that was originally identified on parathyroid cells is not only sensitive to extracellular Ca2+but is activated by extracellular aromatic amino acids. It has been postulated that this receptor may be involved in gastrointestinal hormone secretion. Using transgenic mice expressing a CCK promoter driven/enhanced green fluorescent protein (GFP) transgene, we have been able to identify and purify viable intestinal CCK cells. Intestinal mucosal CCK cells were enriched >200-fold by fluorescence-activated cell sorting. These cells were then used for real-time PCR identification of CaSR. Immunohistochemical staining with an antibody specific for CaSR confirmed colocalization of CaSR to CCK cells. In isolated CCK cells loaded with a Ca2+-sensitive dye, the amino acids phenylalanine and tryptophan, but not nonaromatic amino acids, caused an increase in intracellular Ca2+([Ca2+]i). The increase in [Ca2+]iwas blocked by the CaSR inhibitor Calhex 231. Phenylalanine and tryptophan stimulated CCK release from intestinal CCK cells, and this stimulation was also blocked by CaSR inhibition. Electrophysiological recordings from isolated CCK-GFP cells revealed these cells to possess a predominant outwardly rectifying potassium current. Administration of phenylalanine inhibited basal K+channel activity and caused CCK cell depolarization, consistent with changes necessary for hormone secretion. These findings indicate that amino acids have a direct effect on CCK cells to stimulate CCK release by activating CaSR and suggest that CaSR is the physiological mechanism through which amino acids regulate CCK secretion.
Sorting mouse jejunal epithelial cells with CD24 yields a population with characteristics of intestinal stem cells
Authors: von Furstenberg Richard J. , Gulati Ajay S. , Baxi Anand , Doherty Jason M. , Stappenbeck Thaddeus S. , Gracz Adam D. , Magness Scott T. , Henning Susan J.
Published: December 2010

Intestinal stem cells (ISCs) have been studied for more than three decades; however, their isolation has remained a challenge. We hypothesized that, just as for stem cells of other tissues, one or more membrane markers would allow positive selection of ISCs by antibody-based sorting. To explore this hypothesis, microarray data of putative ISC fractions generated by side population sorting and laser capture microdissection were subjected to bioinformatic analysis to identify common membrane antigens. The microarray comparison suggested CD24 as a candidate surface marker, and immunohistochemistry showed expression of CD24 in epithelial cells of crypt bases. Flow cytometry of jejunal epithelial preparations revealed a CD24+CD45−fraction comprising ∼1% of the cells. Analysis with epithelial cell adhesion molecule and CD31 confirmed that the cell preparations were epithelial and without endothelial contamination. Cycling cells identified by prior injection with 5-ethynyl-2′-deoxyuridine were found predominantly in the CD24losubfraction. Transcript analysis by real-time RT-PCR showed this subfraction to be enriched in the ISC markers leucine-rich-repeat-containing G-protein-coupled receptor 5 (40-fold) and Bmi1 (5-fold), but also enriched in lysozyme (10-fold). Flow cytometry with anti-lysozyme antibodies demonstrated that Paneth cells comprise ∼30% of the CD24losubfraction. Additional flow analyses with leucine-rich-repeat-containing G-protein-coupled receptor 5-enhanced green fluorescent protein (EGFP) epithelium demonstrated colocalization of EGFPhiand CD24lo. In contrast, CD24 cells were negative for the quiescent ISC marker doublecortin and CaM kinase-like-1. Culture of CD24locells in Matrigel generated organoid structures, which included all four epithelial lineages, thus giving functional evidence for the presence of ISCs. We conclude that the CD24lofraction of jejunal epithelium is highly enriched with cycling ISCs. This isolation method should be useful to many investigators in the field to advance both the basic understanding of ISC biology and the therapeutic applications of ISCs.
PDZK1 binding and serine phosphorylation regulate subcellular trafficking of organic anion transport protein 1a1
Authors: Choi Jo H. , Murray John W. , Wolkoff Allan W.
Published: December 2010

Although perturbation of organic anion transport protein (oatp) cell surface expression can result in drug toxicity, little is known regarding mechanisms regulating its subcellular distribution. Many members of the oatp family, including oatp1a1, have a COOH-terminal PDZ consensus binding motif that interacts with PDZK1, while serines upstream of this site (S634 and S635) can be phosphorylated. Using oatp1a1 as a prototypical member of the oatp family, we prepared plasmids in which these serines were mutated to glutamic acid [E634E635 (oatp1a1EE), phosphomimetic] or alanine [A634A635 (oatp1a1AA), nonphosphorylatable]. Distribution of oatp1a1AAand oatp1a1EEwas largely intracellular in transfected human embryonic kidney (HEK) 293T cells. Cotransfection with a plasmid encoding PDZK1 revealed that oatp1a1AAwas now expressed largely on the cell surface, while oatp1a1EEremained intracellular. To quantify these changes, studies were performed in HuH7 cells stably transfected with these oatp1a1 plasmids. These cells endogenously express PDZK1. Surface biotinylation at 4°C followed by shift to 37°C showed that oatp1a1EEinternalizes quickly compared with oatp1a1AA. To examine a physiological role for phosphorylation in oatp1a1 subcellular distribution, studies were performed in rat hepatocytes exposed to extracellular ATP, a condition that stimulates serine phosphorylation of oatp1a1 via activity of a purinergic receptor. Internalization of oatp1a1 under these conditions was rapid. Thus, although PDZK1 binding is required for optimal cell surface expression of oatp1a1, phosphorylation provides a mechanism for fast regulation of the distribution of oatp1a1 between the cell surface and intracellular vesicular pools. Identification of the proteins and motor molecules that mediate these trafficking events represents an important area for future study.
Association of PDZ-containing protein PDZD11 with the human sodium-dependent multivitamin transporter
Authors: Nabokina Svetlana M. , Subramanian Veedamali S. , Said Hamid M.
Published: December 2010

Intestinal absorption of biotin is mediated via the sodium-dependent multivitamin transporter (SMVT). Studies from our laboratory and others have characterized different aspects of the human SMVT (hSMVT), but nothing is currently known about protein(s) that may interact with hSMVT and affect its physiology/biology. In this study, a PDZ-containing protein PDZD11 was identified as an interacting partner with hSMVT using yeast two-hybrid screen of a human intestinal cDNA library. The interaction between hSMVT and PDZD11 was confirmed by in vitro GST-pull-down assay and in vivo in a mammalian cell environment by a two-hybrid luciferase and coimmunoprecipitation assays. Furthermore, confocal imaging of live human intestinal epithelial HuTu-80 cells expressing hSMVT-GFP and DsRed-PDZD11 demonstrated colocalization of these two proteins. We also examined the functional consequence of the interaction between hSMVT and PDZD11 in HuTu-80 cells and observed significant induction in [3H]biotin uptake upon coexpression of hSMVT and PDZD11. In contrast, knocking down of PDZD11 with gene-specific small interfering RNA led to a significant decrease in biotin uptake; biotinylation assay showed this to be associated with a marked decrease in level of expression of hSMVT at the cell membrane. By truncation approach, we also demonstrated that the PDZ binding domain that is located in the COOH-terminal tail of hSMVT polypeptide is involved in the interaction with PDZD11. These results demonstrate for the first time that PDZD11 is an interacting partner with hSMVT in intestinal epithelial cells and that this interaction affects hSMVT function and cell biology.
Catechin treatment improves cerebrovascular flow-mediated dilation and learning abilities in atherosclerotic mice
Authors: Drouin Annick , Bolduc Virginie , Thorin-Trescases Nathalie , Bélanger Élisabeth , Fernandes Priscilla , Baraghis Edward , Lesage Frédéric , Gillis Marc-Antoine , Villeneuve Louis , Hamel Edith , Ferland Guylaine , Thorin Eric
Published: December 2010

Severe dyslipidemia and the associated oxidative stress could accelerate the age-related decline in cerebrovascular endothelial function and cerebral blood flow (CBF), leading to neuronal loss and impaired learning abilities. We hypothesized that a chronic treatment with the polyphenol catechin would prevent endothelial dysfunction, maintain CBF responses, and protect learning abilities in atherosclerotic (ATX) mice. We treated ATX (C57Bl/6-LDLR−/−hApoB+/+; 3 mo old) mice with catechin (30 mg·kg−1·day−1) for 3 mo, and C57Bl/6 [wild type (WT), 3 and 6 mo old] mice were used as controls. ACh- and flow-mediated dilations (FMD) were recorded in pressurized cerebral arteries. Basal CBF and increases in CBF induced by whisker stimulation were measured by optical coherence tomography and Doppler, respectively. Learning capacities were evaluated with the Morris water maze test. Compared with 6-mo-old WT mice, cerebral arteries from 6-mo-old ATX mice displayed a higher myogenic tone, lower responses to ACh and FMD, and were insensitive to NOS inhibition ( P < 0.05), suggesting endothelial dysfunction. Basal and increases in CBF were lower in 6-mo-old ATX than WT mice ( P < 0.05). A decline in the learning capabilities was also observed in ATX mice ( P < 0.05). Catechin 1) reduced cerebral superoxide staining ( P < 0.05) in ATX mice, 2) restored endothelial function by reducing myogenic tone, improving ACh- and FMD and restoring the sensitivity to nitric oxide synthase inhibition ( P < 0.05), 3) increased the changes in CBF during stimulation but not basal CBF, and 4) prevented the decline in learning abilities ( P < 0.05). In conclusion, catechin treatment of ATX mice prevents cerebrovascular dysfunctions and the associated decline in learning capacities.
Mechanisms of novel cardioprotective functions of CCN2/CTGF in myocardial ischemia-reperfusion injury
Authors: Ahmed M. Shakil , Gravning Jørgen , Martinov Vladimir N. , von Lueder Thomas G. , Edvardsen Thor , Czibik Gabor , Moe Ingvild T. , Vinge Leif E. , Øie Erik , Valen Guro , Attramadal Håvard
Published: December 2010

CCN2/connective tissue growth factor (CTGF), a CCN family matricellular protein repressed in healthy hearts after birth, is induced in heart failure of various etiologies. Multiple cellular and biological functions have been assigned to CCN2/CTGF depending on cellular context. However, the functions and mechanisms of action of CCN2/CTGF in the heart as well as its roles in cardiac physiology and pathophysiology remain unknown. Transgenic mice with cardiac-restricted overexpression of CTGF (Tg-CTGF) were generated and compared with nontransgenic littermate control (NLC) mice. Tg-CTGF mice displayed slightly lower cardiac mass and inconspicuous increase of myocardial collagen compared with NLC mice but no evidence of contractile dysfunction. Analysis of the myocardial transcriptome by DNA microarray revealed activation of several distinct gene programs in Tg-CTGF hearts involved in cardioprotection and growth inhibition. Indeed, Tg-CTGF mice subjected to ischemia-reperfusion injury by in situ transient occlusion of the left anterior descending coronary artery in vivo displayed reduced vulnerability with markedly diminished infarct size. These findings were recapitulated in isolated hearts perfused with recombinant human (h)CTGF before the ischemia-reperfusion procedure. Consistently, Tg-CTGF hearts, as well as isolated adult cardiac myocytes exposed to recombinant hCTGF, displayed enhanced phosphorylation and activity of the Akt/p70S6 kinase/GSK-3β salvage kinase pathway and induction of several genes with reported cardioprotective functions. Inhibition of Akt activities also prevented the cardioprotective phenotype of hearts from Tg-CTGF mice. This report provides novel evidence that CTGF confers cardioprotection by salvage phosphokinase signaling leading to inhibition of GSK-3β activities, activation of phospho-SMAD2, and reprogramming of gene expression.
Endogenous HMGB1 contributes to ischemia-reperfusion-induced myocardial apoptosis by potentiating the effect of TNF-α/JNK
Authors: Xu Hu , Yao Yongwei , Su Zhaoliang , Yang Yunbo , Kao Raymond , Martin Claudio M. , Rui Tao
Published: December 2010

High-mobility group box 1 (HMGB1) is a nuclear protein that has been implicated in the myocardial inflammation and injury induced by ischemia-reperfusion (I/R). The purpose of the present study was to assess the role of HMGB1 in myocardial apoptosis induced by I/R. In vivo, myocardial I/R induced an increase in myocardial HMGB1 expression and apoptosis. Inhibition of HMGB1 (A-box) ameliorated the I/R-induced myocardial apoptosis. In vitro, isolated cardiac myocytes were challenged with anoxia-reoxygenation (A/R; in vitro correlate to I/R). A/R-challenged myocytes also generated HMGB1 and underwent apoptosis. Inhibition of HMGB1 attenuated the A/R-induced myocyte apoptosis. Exogenous HMGB1 had no effect on myocyte apoptosis. However, inhibition of HMGB1 attenuated myocyte TNF-α production after the A/R was challenged; surprisingly, HMGB1 itself did not induce myocyte TNF-α production. Exogenous TNF-α induced a moderate proapoptotic effect on the myocytes, an effect substantially potentiated by coadministration of HMGB1. It is generally accepted that apoptosis induced by TNF-α is regulated by the balance of activation of c-Jun NH2-terminal kinase (JNK) and NF-κB. Indeed, in the present study, TNF-α increased the phosphorylation status of JNK and p65, a subunit of NF-κB; HMGB1 greatly potentiated TNF-α-induced JNK phosphorylation. Furthermore, inhibition of JNK (SP-600125) prevented the myocyte apoptosis induced by a TNF-α/HMGB1 cocktail. Finally, A/R increased HMGB1 production in both wild-type and toll-like receptor 4-deficient myocytes; however, deficiency in toll-like receptor 4 diminished A/R-induced myocyte apoptosis, TNF-α, and JNK activation. Our results indicate that myocyte-derived HMGB1 and TNF-α work in concert to promote I/R-induced myocardial apoptosis through JNK activation.
Moderate exercise training provides left ventricular tolerance to acute pressure overload
Authors: Moreira-Gonçalves Daniel , Henriques-Coelho Tiago , Fonseca Hélder , Ferreira Rita Maria , Amado Francisco , Leite-Moreira Adelino , Duarte José Alberto
Published: December 2010

The present study evaluated the impact of moderate exercise training on the cardiac tolerance to acute pressure overload. Male Wistar rats were randomly submitted to exercise training or sedentary lifestyle for 14 wk. At the end of this period, the animals were anaesthetized, mechanically ventilated, and submitted to hemodynamic evaluation with biventricular tip pressure manometers. Acute pressure overload was induced by banding the descending aorta to induce a 60% increase of peak systolic left ventricular pressure during 120 min. This resulted in the following experimental groups: 1) sedentary without banding (SED + Sham), 2) sedentary with banding (SED + Band), and 3) exercise trained with banding (EX + Band). In response to aortic banding, SED + Band animals could not sustain the 60% increase of peak systolic pressure for 120 min, even with additional narrowing of the banding. This was accompanied by a reduction of dP/d tmax and dP/d tmin and a prolongation of the time constant tau, indicating impaired systolic and diastolic function. This impairment was not observed in EX + Band ( P < 0.05 vs. SED + Band). Additionally, compared with SED + Band, EX + Band presented less myocardial damage, exhibited attenuated protein expression of active caspase-3 and NF-κB ( P < 0.016), and showed less protein carbonylation and nitration ( P < 0.05). These findings support our hypothesis that exercise training has a protective role in the modulation of the early cardiac response to pressure overload.
Serotonin transporter interacts with the PDGFβ receptor in PDGF-BB-induced signaling and mitogenesis in pulmonary artery smooth muscle cells
Authors: Ren Wenying , Watts Stephanie W. , Fanburg Barry L.
Published: December 2010

The serotonin transporter (SERT) and the platelet-derived growth factor receptor (PDGFR) have been implicated in both clinical and experimental pulmonary hypertension (PH) and the facilitation of pulmonary artery smooth muscle cell (PASMC) growth. To gain a better understanding of the possible relationship of these two cell surface molecules we have explored interactions between SERT and PDGFR. We have previously demonstrated that SERT transactivates PDGFRβ in serotonin-stimulated PASMC proliferation. We now provide evidence for a role for SERT in PDGF-BB signaling and PASMC proliferation by using pharmacological inhibitors, genetic ablation, and construct overexpression of SERT. The results show that four tested SERT blockers dose dependently inhibit PDGF-stimulated human and bovine PASMC proliferation with comparable efficacy to that of PDGFR inhibitors, whereas 5-HT1B or 5-HT2A receptor inhibitors had no effect. Combinations of the SERT and PDGFR inhibitors led to synergistic/additive inhibition. Similarly, PDGF-induced PASMC proliferation was attenuated by small interfering RNA downregulation of SERT. Inhibition of SERT in PASMCs attenuated PDGF-induced phosphorylation of PDGFRβ, Akt, and p38 but not Erk. Overexpression of SERT in HEK293 cells led to enhanced Akt phosphorylation by PDGF, which was blunted by a SERT PDZ motif mutant, indicating the mechanistic need for the PDZ motif of SERT in PDGF signaling. Furthermore, coimmunoprecipitation experiments showed that SERT and PDGFRβ become physically associated upon PDGF stimulation. In total, the data show for the first time an important interactive relationship between SERT and the PDGFRβ in the production of PASMC proliferation triggered by PDGF that may be important in PH.
Genomic predictors of the maximal O2 uptake response to standardized exercise training programs
Authors: Bouchard Claude , Sarzynski Mark A. , Rice Treva K. , Kraus William E. , Church Timothy S. , Sung Yun Ju , Rao D. C. , Rankinen Tuomo
Published: December 2010

Low cardiorespiratory fitness is a powerful predictor of morbidity and cardiovascular mortality. In 473 sedentary adults, all whites, from 99 families of the Health, Risk Factors, Exercise Training, and Genetics (HERITAGE) Family Study, the heritability of gains in maximal O2 uptake (V̇o2max) after exposure to a standardized 20-wk exercise program was estimated at 47%. A genome-wide association study based on 324,611 single-nucleotide polymorphisms (SNPs) was undertaken to identify SNPs associated with improvements in V̇o2max Based on single-SNP analysis, 39 SNPs were associated with the gains with P < 1.5 × 10−4. Stepwise multiple regression analysis of the 39 SNPs identified a panel of 21 SNPs that accounted for 49% of the variance in V̇o2max trainability. Subjects who carried ≤9 favorable alleles at these 21 SNPs improved their V̇o2max by 221 ml/min, whereas those who carried ≥19 of these alleles gained, on average, 604 ml/min. The strongest association was with rs6552828, located in the acyl-CoA synthase long-chain member 1 ( ACSL1) gene, which accounted by itself for ∼6% of the training response of V̇o2max. The genes nearest to the SNPs that were the strongest predictors were PR domain-containing 1 with ZNF domain ( PRDM1); glutamate receptor, ionotropic, N-methyl-d-aspartate 3A ( GRIN3A); K+ channel, voltage gated, subfamily H, member 8 ( KCNH8); and zinc finger protein of the cerebellum 4 ( ZIC4). The association with the SNP nearest to ZIC4 was replicated in 40- to 65-yr-old, sedentary, overweight, and dyslipidemic subjects trained in Studies of a Targeted Risk Reduction Intervention Through Defined Exercise (STRRIDE; n = 183). Two SNPs were replicated in sedentary obese white women exercise trained in the Dose Response to Exercise (DREW) study ( n = 112): rs1956197 near dishevelled associated activator of morphogenesis 1 ( DAAM1) and rs17117533 in the vicinity of necdin ( NDN). The association of SNPs rs884736 in the calmodulin-binding transcription activator 1 ( CAMTA1) locus and rs17581162 ∼68 kb upstream from regulator of G protein signaling 18 ( RGS18) with the gains in V̇o2max in HERITAGE whites were replicated in HERITAGE blacks ( n = 247). These genomic predictors of the response of V̇o2max to regular exercise provide new targets for the study of the biology of fitness and its adaptation to regular exercise. Large-scale replication studies are warranted.
Motor unit recruitment when neuromuscular electrical stimulation is applied over a nerve trunk compared with a muscle belly: triceps surae
Authors: Bergquist A. J. , Clair J. M. , Collins D. F.
Published: December 2010

Neuromuscular electrical stimulation (NMES) can be delivered over a nerve trunk or muscle belly and can generate contractions by activating motor (peripheral pathway) and sensory (central pathway) axons. In the present experiments, we compared the peripheral and central contributions to plantar flexion contractions evoked by stimulation over the tibial nerve vs. the triceps surae muscles. Generating contractions through central pathways follows Henneman's size principle, whereby low-threshold motor units are activated first, and this may have advantages for rehabilitation. Statistical analyses were performed on data from trials in which NMES was delivered to evoke 10–30% maximum voluntary torque 2–3 s into the stimulation (Time1). Two patterns of stimulation were delivered: 1) 20 Hz for 8 s; and 2) 20–100-20 Hz for 3–2-3 s. Torque and soleus electromyography were quantified at the beginning (Time1) and end (Time2; 6–7 s into the stimulation) of each stimulation train. H reflexes (central pathway) and M waves (peripheral pathway) were quantified. Motor unit activity that was not time-locked to each stimulation pulse as an M wave or H reflex (“asynchronous” activity) was also quantified as a second measure of central recruitment. Torque was not different for stimulation over the nerve or the muscle. In contrast, M waves were approximately five to six times smaller, and H reflexes were approximately two to three times larger during NMES over the nerve vs. the muscle. Asynchronous activity increased by 50% over time, regardless of the stimulation location or pattern, and was largest during NMES over the muscle belly. Compared with NMES over the triceps surae muscles, NMES over the tibial nerve produced contractions with a relatively greater central contribution, and this may help reduce muscle atrophy and fatigue when NMES is used for rehabilitation.
Effects of inhaled nitric oxide at rest and during exercise in idiopathic pulmonary fibrosis
Authors: Blanco Isabel , Ribas Jesús , Xaubet Antoni , Gómez Federico P. , Roca Josep , Rodriguez-Roisin Robert , Barberà Joan A.
Published: December 2010

Patients with idiopathic pulmonary fibrosis (IPF) usually develop hypoxemia and pulmonary hypertension when exercising. To what extent endothelium-derived vasodilating agents modify these changes is unknown. The study was aimed to investigate in patients with IPF whether exercise induces changes in plasma levels of endothelium-derived signaling mediators, and to assess the acute effects of inhaled nitric oxide (NO) on pulmonary hemodynamics and gas exchange, at rest and during exercise. We evaluated seven patients with IPF (6 men/1 woman; 57 ± 11 yr; forced vital capacity, 60 ± 13% predicted; carbon monoxide diffusing capacity, 52 ± 10% predicted). Levels of endothelin, 6-keto-prostaglandin-F1α, thromboxane B2, and nitrates were measured at rest and during submaximal exercise. Pulmonary hemodynamics and gas exchange, including ventilation-perfusion relationships, were assessed breathing ambient air and 40 ppm NO, both at rest and during submaximal exercise. The concentration of thromboxane B2increased during exercise ( P = 0.046), whereas levels of other mediators did not change. The change in 6-keto-prostaglandin-F1αcorrelated with that of mean pulmonary arterial pressure ( r = 0.94; P < 0.005). Inhaled NO reduced mean pulmonary arterial pressure at rest (−4.6 ± 2.1 mmHg) and during exercise (−11.7 ± 7.1 mmHg) ( P = 0.001 and P = 0.004, respectively), without altering arterial oxygenation or ventilation-perfusion distributions in any of the study conditions. Alveolar-to-capillary oxygen diffusion limitation, which accounted for the decrease of arterial Po2during exercise, was not modified by NO administration. We conclude that, in IPF, some endothelium-derived signaling molecules may modulate the development of pulmonary hypertension during exercise, and that the administration of inhaled NO reduces pulmonary vascular resistance without disturbing gas exchange.
Complex systems in pulmonary medicine: a systems biology approach to lung disease
Authors: Kaminsky David A. , Irvin Charles G. , Sterk Peter J.
Published: December 2010

The lung is a highly complex organ that can only be understood by integrating the many aspects of its structure and function into a comprehensive view. Such a view is provided by a systems biology approach, whereby the many layers of complexity, from the molecular genetic, to the cellular, to the tissue, to the whole organ, and finally to the whole body, are synthesized into a working model of understanding. The systems biology approach therefore relies on the expertise of many disciplines, including genomics, proteomics, metabolomics, physiomics, and, ultimately, clinical medicine. The overall structure and functioning of the lung cannot be predicted from studying any one of these systems in isolation, and so this approach highlights the importance of emergence as the fundamental feature of systems biology. In this paper, we will provide an overview of a systems biology approach to lung disease by briefly reviewing the advances made at many of these levels, with special emphasis on recent work done in the realm of pulmonary physiology and the analysis of clinical phenotypes.