Isoorientin Decreases Cell Migration via Decreasing Functional Activity and Molecular Expression of Proton-Linked Monocarboxylate Transporters in Human Lung Cancer Cells.

Aggressive tumor cells mainly rely on glycolysis, and further release vast amounts of lactate and protons by monocarboxylate transporter (MCT), which causes a higher intracellular pH (pHi) and acidic extracellular pH. Isoorientin, a principle flavonoid compound extracted from several plant species, shows various pharmacological activities. However, effects of isoorientin on anticancer and MCT await to explore in human lung cancer cells. Human lung cancer tissues were obtained from cancer patients undergoing surgery, while the human lung adenocarcinoma cells (A549) were bought commercially. Change of pHi was detected by microspectrofluorometry method with a pH-sensitive fluorescent dye, BCECF. MTT and wound-healing assay were used to detect the cell viability and migration, respectively. Western blot techniques and immunocytochemistry staining were used to detect the protein expression. Our results indicated that the expression of MCTs1/4 and CD147 were upregulated significantly in human lung tissues. In experiments of A549 cells, under HEPES-buffer, the resting pHi was 7.47, and isoorientin (1-300µM) inhibited functional activity of MCT concentration-dependently (up to -42%). Pretreatment with isoorientin (3-100µM) for 24h, MCT activity and cell migration were significantly inhibited (-25% and -40%, respectively), while the cell viability was not affected. Moreover, the expression of MCTs1/4, CD147, and matrix metalloproteinase (MMP) 2/9 were significantly down regulated. In summary, MCTs1/4 and CD147 are significantly upregulated in human lung adenocarcinoma tissues, and isoorientin inhibits cells-migration by inhibiting activity/expression of MCTs1/4 and MMPs2/9 in human lung cancer cells. These novel findings suggest that isoorientin could be a promising pharmacological agent for lung cancer.

Nicorandil prevents doxorubicin-induced human umbilical vein endothelial cell apoptosis.

Nicorandil is an adenosine triphosphate-sensitive potassium channel opener with additional antioxidant properties. Doxorubicin (DOX) is an anticancer drug that exerts oxidation-mediated adverse cardiovascular effects. This study examined the effects of nicorandil on DOX-induced cytotoxicity in human umbilical vein endothelial cells (HUVECs) and underlying intracellular signaling mechanisms. Cultured HUVECs were pretreated with nicorandil (0.1, 0.3, 1, 3, and 10 µM) for 12 h and then treated with DOX (1 µM) for 24 h. Cell viability and cytotoxicity were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays, respectively. Cell apoptosis was examined using a caspase-3 activity assay, and DNA fragmentation was detected through TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) staining. Western blot analysis was conducted to determine the related protein expression. DOX markedly increased reactive oxygen species production, p53 expression, caspase-3 activity, cleaved caspase-3 levels, and TUNEL-positive cell numbers but reduced Bcl-2 expression and intracellular antioxidant enzyme levels; these effects were effectively antagonized through nicorandil (3 µM, 12 h) pretreatment, which resulted in HUVECs being protected from DOX-induced apoptosis. Activating transcription factor 3 (ATF3), a stress-induced transcription factor, was induced by nicorandil (3 µM). Furthermore, nicorandil (3 µM) enhanced nuclear factor erythroid 2-related factor 2 (Nrf2) translocation and heme oxygenase-1 (HO-1) expression. ATF3 short interfering RNA significantly attenuated nicorandil-mediated Nrf2 translocation, HO-1 expression, and inhibitory effects on DOX-stimulated reactive oxygen species production and cell apoptosis. In summary, nicorandil may protect HUVECs from DOX-induced apoptosis, in part through ATF3-mediated Nrf2/HO-1 signaling pathways, which potentially protect the vessels from severe DOX toxicity.

Corrigendum to "Cafestol Inhibits Cyclic-Strain-Induced Interleukin-8, Intercellular Adhesion Molecule-1, and Monocyte Chemoattractant Protein-1 Production in Vascular Endothelial Cells".

[This corrects the article DOI: 10.1155/2018/7861518.].

Tanshinone IIA Inhibits High Glucose-Induced Collagen Synthesis via Nuclear Factor Erythroid 2-Related Factor 2 in Cardiac Fibroblasts.

BACKGROUND/AIMS: Diabetes is associated with increased incidence of myocardial dysfunction, which is partly characterized by interstitial and perivascular fibrosis. Cardiac fibroblasts have been identified as an important participant in the development of cardiac fibrosis. Exposure of cultured cardiac fibroblasts to high glucose resulted in increased collagen synthesis. Tanshinone IIA can alleviate the ventricular fibrosis that develops in a number of different experimental conditions. However, whether tanshinone IIA can prevent high glucose-induced collagen synthesis in cardiac fibroblasts remains unknown. The aim of this study was to evaluate the effects of tanshinone IIA on high glucose-induced collagen synthesis in cardiac fibroblasts. METHODS: Rat cardiac fibroblasts were cultured in high glucose (25 mM) media in the absence or presence of tanshinone IIA and the changes in collagen synthesis, transforming growth factor-ß1 (TGF-ß1) production and related signaling molecules were assessed by 3H-proline incorporation, quantitative polymerase chain reaction, enzyme linked immunosorbent assay, and Western blotting. RESULTS: The results indicate cardiac fibroblasts exposed to high glucose condition show increased cell proliferation and collagen synthesis and these effects were abolished by tanshinone IIA treatment. Furthermore, the inhibitory effect of tanshinone IIA on high glucose induced cell proliferation and collagen synthesis may be associated with its activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) and the inhibition of TGF-ß1 production and Smad2/3 phosphorylation. CONCLUSION: In summary, our results highlights the critical role tanshinone IIA plays as an antioxidant in attenuating high glucose-mediated collagen synthesis through inhibiting TGF-ß1/Smad signaling in cardiac fibroblasts which provide a mechanistic basis for the clinical application of tanshinone IIA in the treating diabetic-related cardiac fibrosis.

Cafestol Inhibits Cyclic-Strain-Induced Interleukin-8, Intercellular Adhesion Molecule-1, and Monocyte Chemoattractant Protein-1 Production in Vascular Endothelial Cells.

Moderate coffee consumption is inversely associated with cardiovascular disease mortality; however, mechanisms underlying this causal effect remain unclear. Cafestol, a diterpene found in coffee, has various properties, including an anti-inflammatory property. This study investigated the effect of cafestol on cyclic-strain-induced inflammatory molecule secretion in vascular endothelial cells. Cells were cultured under static or cyclic strain conditions, and the secretion of inflammatory molecules was determined using enzyme-linked immunosorbent assay. The effects of cafestol on mitogen-activated protein kinases (MAPK), heme oxygenase-1 (HO-1), and sirtuin 1 (Sirt1) signaling pathways were examined using Western blotting and specific inhibitors. Cafestol attenuated cyclic-strain-stimulated intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein- (MCP-) 1, and interleukin- (IL-) 8 secretion. Cafestol inhibited the cyclic-strain-induced phosphorylation of extracellular signal-regulated kinase and p38 MAPK. By contrast, cafestol upregulated cyclic-strain-induced HO-1 and Sirt1 expression. The addition of zinc protoporphyrin IX, sirtinol, or Sirt1 silencing (transfected with Sirt1 siRNA) significantly attenuated cafestol-mediated modulatory effects on cyclic-strain-stimulated ICAM-1, MCP-1, and IL-8 secretion. This is the first study to report that cafestol inhibited cyclic-strain-induced inflammatory molecule secretion, possibly through the activation of HO-1 and Sirt1 in endothelial cells. The results provide valuable insights into molecular pathways that may contribute to the effects of cafestol.

Cafestol, a coffee diterpene, inhibits urotensin II-induced interleukin-8 expression in human umbilical vein endothelial cells.

Cafestol, a diterpene molecule found in the berries of Coffea arabica L. (Rubiaceae), has been shown to exercise anti-angiogenic and anti-tumorigenic effects. However, cafestol's cellular mechanism has yet to be fully investigated. We previously demonstrated that urotensin II enhanced interleukin-8 secretion by endothelial cells, thereby increasing endothelial cell proliferation. Urotensin II may also participate in angiogenesis and tumor infiltration by macrophages. However, the effects of cafestol on urotensin II-induced interleukin-8 expression and cellular proliferation have not been determined. Here, we showed that pretreatment with cafestol inhibited urotensin II-stimulated endothelial cell proliferation. Further experiments demonstrated that cafestol increased translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and expression of enhanced heme oxygenase-1. Moreover, cafestol inhibited expression of urotensin II-induced interleukin-8. Cafestol's inhibitory effects on interleukin-8 expression and cellular proliferation induced by urotensin II were significantly abrogated by heme oxygenase-1 silencing, suggesting it may be involved in mediating the effects of cafestol. This study reports that cafestol inhibits urotensin II-induced interleukin-8 expression and cell proliferation via Nrf2/heme oxygenase-1-dependent mechanism in endothelial cells. These findings provide novel insight into the signaling pathways that may be important in mediating the effects of cafestol.

Lipopolysaccharide pretreatment increases protease-activated receptor-2 expression and monocyte chemoattractant protein-1 secretion in vascular endothelial cells.

BACKGROUND: This study investigated whether lipopolysaccharide (LPS) increase protease-activated receptor-2 (PAR-2) expression and enhance the association between PAR-2 expression and chemokine production in human vascular endothelial cells (ECs). METHODS: The morphology of ECs was observed through microphotography in cultured human umbilical vein ECs (EA. hy926 cells) treated with various LPS concentrations (0, 0.25, 0.5, 1, and 2 µg/mL) for 24 h, and cell viability was assessed using the MTT assay. Intracellular calcium imaging was performed to assess agonist (trypsin)-induced PAR-2 activity. Western blotting was used to explore the LPS-mediated signal transduction pathway and the expression of PAR-2 and adhesion molecule monocyte chemoattractant protein-1 (MCP-1) in ECs. RESULTS: Trypsin stimulation increased intracellular calcium release in ECs. The calcium influx was augmented in cells pretreated with a high LPS concentration (1 µg/mL). After 24 h treatment of LPS, no changes in ECs viability or morphology were observed. Western blotting revealed that LPS increased PAR-2 expression and enhanced trypsin-induced extracellular signal-regulated kinase (ERK)/p38 phosphorylation and MCP-1 secretion. However, pretreatment with selective ERK (PD98059), p38 mitogen-activated protein kinase (MAPK) (SB203580) inhibitors, and the selective PAR-2 antagonist (FSLLRY-NH2) blocked the effects of LPS-activated PAR-2 on MCP-1 secretion. CONCLUSIONS: Our findings provide the first evidence that the bacterial endotoxin LPS potentiates calcium mobilization and ERK/p38 MAPK pathway activation and leads to the secretion of the pro-inflammatory chemokine MCP-1 by inducing PAR-2 expression and its associated activity in vascular ECs. Therefore, PAR-2 exerts vascular inflammatory effects and plays an important role in bacterial infection-induced pathological responses.

Nicorandil Inhibits Cyclic Strain-Induced Interleukin-8 Expression in Human Umbilical Vein Endothelial Cells.

BACKGROUND: Nicorandil, a mitochondrial adenosine triphosphate-sensitive potassium (mitoKATP) channel opener, exerts protective effects on the cardiovascular system. This study examined the effect of nicorandil on cyclic strain-induced interleukin-8 (IL-8) expression in human umbilical vein endothelial cells (HUVECs). METHODS: Cultured HUVECs were exposed to cyclic strain in the presence or absence of nicorandil (1-10 µmol/l); we then analyzed IL-8 expression. We also assessed the effects of nicorandil on heme oxygenase-1 (HO-1) expression and cyclic strain-modulated IL-8 expression after HO-1 silencing in HUVECs. SUMMARY: HUVECs exposed to cyclic strain showed increased IL-8 messenger RNA expression and protein secretion. Nicorandil (1-10 µmol/l) inhibited cyclic strain-induced IL-8 expression, whereas 5-hydroxydecanoate (100 µmol/l), a selective inhibitor of the mitoKATP channel, completely reversed the inhibitory effects of nicorandil on cyclic strain-induced IL-8 expression. We demonstrated that nicorandil increased HO-1 expression in HUVECs. In addition, cobalt protoporphyrin (10 µmol/l), an inducer of HO-1 expression, mimicked the effects of nicorandil and inhibited IL-8 expression under cyclic strain, whereas zinc protoporphyrin IX (10 µmol/l), an inhibitor of HO-1 expression, antagonized the effect of nicorandil. HO-1 silencing significantly abrogated the inhibitory effects of nicorandil on cyclic strain-induced IL-8 expression, suggesting that HO-1 plays a role in the mechanism of action of nicorandil. KEY MESSAGES: This study is the first to report that nicorandil inhibits cyclic strain-induced IL-8 expression through the induction of HO-1 expression in HUVECs. This finding provides valuable new insight into the molecular pathways contributing to the vasoprotective effects of nicorandil.

Tanshinone IIA Induces Heme Oxygenase 1 Expression and Inhibits Cyclic Strain-Induced Interleukin 8 Expression in Vascular Endothelial Cells.

Tanshinone IIA is the main effective component of Salvia miltiorrhiza, known as "Danshen," which has been used in many therapeutic remedies in traditional Chinese medicine. However, the direct effects of tanshinone IIA on vascular endothelial cells have not yet been fully described. In the present study, we demonstrated that tanshinone IIA increased heme oxygenase-1 (HO-1) expression in human umbilical vein endothelial cells. Western blot analyses and experiments with specific inhibitors indicated tanshinone IIA enhanced HO-1 expression through the activation of phosphoinositide 3-kinase (PI3K)/Akt and the subsequent induction of nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation. In addition, tanshinone IIA inhibited cyclic strain induced interleukin-8 (IL-8) expression. HO-1 silencing significantly abrogated the repressive effects of tanshinone IIA on strain-induced IL-8 expression, which suggests HO-1 has a role in mediating the effects of tanshinone IIA. This study reports for the first time that tanshinone IIA inhibits cyclic strain-induced IL-8 expression via the induction of HO-1 in endothelial cells, providing valuable new insight into the molecular pathways that may contribute to the effects of tanshinone IIA.

Inhibition of voltage-gated Na+ channels by hinokiol in neuronal cells.

BACKGROUND: Hinokiol is a naturally occurring diterpenoid compound isolated from plants such as Taiwania cryptomerioides. Anti-oxidation, anti-cancer, and anti-inflammation effects of this compound have been reported. It is not yet known if hinokiol affects neurons or neuronal ion channel activities. We reported here that hinokiol inhibited voltage-gated Na(+) channels (VGSC) in neuronal cells and we characterized the mechanisms of block. METHODS: The effects of hinokiol on Na(+) channels were examined using the voltage-clamp (whole-cell mode) technique. RESULTS: VGSC was blocked by hinokiol in a concentration-dependent and state-dependent manner in neuroblastoma N2A cells: IC(50) are 11.3 and 37.4µM in holding potentials of -70 and -100 mV, respectively. In the presence of hinokiol there was a 13-mV left shift in steady-state inactivation curves; however, activation gating was not altered. VGSC inhibition by hinokiol did not require channel opening and was thus considered to be closed-channel block. In the presence of hinokiol, since the degree of block did not enhance with stimulation frequency, block by hinokiol thus did not exhibit use-dependence. Recovery from channel inactivation was not significantly affected in the presence of hinokiol. In addition, hinokiol also inhibited VGSC of differentiated neuronal NG108-15 cells and rat hippocampal CA1 neurons. CONCLUSION: Our results therefore suggest hinokiol inhibited VGSC in a closed-channel block manner and such inhibition involved intensification of channel inactivation.

Lycopene inhibits cyclic strain-induced endothelin-1 expression through the suppression of reactive oxygen species generation and induction of heme oxygenase-1 in human umbilical vein endothelial cells.

Lycopene is the most potent active antioxidant among the major carotenoids, and its use has been associated with a reduced risk for cardiovascular disease (CVD). Endothelin-1 (ET-1) is a powerful vasopressor synthesized by endothelial cells and plays a crucial role in the pathophysiology of CVD. However, the direct effects of lycopene on vascular endothelial cells have not been fully described. This study investigated the effects of lycopene on cyclic strain-induced ET-1 gene expression in human umbilical vein endothelial cells (HUVECs) and identified the signal transduction pathways that are involved in this process. Cultured HUVECs were exposed to cyclic strain (20% in length, 1 Hz) in the presence or absence of lycopene. Lycopene inhibited strain-induced ET-1 expression through the suppression of reactive oxygen species (ROS) generation through attenuation of p22(phox) mRNA expression and NAD(P)H oxidase activity. Furthermore, lycopene inhibited strain-induced ET-1 secretion by reducing ROS-mediated extrace-llular signal-regulated kinase (ERK) phosphorylation. Conversely, lycopene treatment enhanced heme oxygenase-1 (HO-1) gene expression through the activation of phosphoinositide 3-kinase (PI3K)/Akt pathway, followed by induction of the nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation; in addition, HO-1 silencing partially inhibited the repressive effects of lycopene on strain-induced ET-1 expression. In summary, our study showed, for the first time, that lycopene inhibits cyclic strain-induced ET-1 gene expression through the suppression of ROS generation and induction of HO-1 in HUVECs. Therefore, this study provides new valuable insight into the molecular pathways that may contribute to the proposed beneficial effects of lycopene on the cardiovascular system.

Functional characterization of intracellular pH regulators responsible for acid extrusion in human radial artery smooth muscle cells.

Intracellular pH (pHi) is a critical factor influencing many important cellular functions. Acid extrusion carriers such as an Na⁺/H⁺ exchanger (NHE) Na⁺/HCO3⁻ cotransporter (NBC) and monocarboxylate transporters (MCT) can be activated when cells are in an acidic condition (pHi < 7.1). Human radial artery smooth muscle cells (HRASMC) is an important conduit in coronary artery bypass graft surgery. However, such far, the pHi regulators have not been characterized in HRASMCs. We therefore investigated the mechanism of pHi recovery from intracellular acidosis and alkalosis, induced by NH4Cl-prepulse and Na-acetate-prepulse, respectively, using intracellular 2',7'-bis(2-carboxethyl)-5(6)- carboxy-fluorescein (BCECF)-fluorescence in HRASMCs. Cultured HRASMCs were derived from the segments of human radial artery that were obtained from patients undergoing bypass grafting. The resting pHi is 7.22 ± 0.03 and 7.17 ± 0.02 for HEPES- (nominally HCO3⁻-free) and CO2/HCO3⁻- buffered solution, respectively. In HEPES-buffered solution, a pHi recovery from induced intracellular acidosis could be blocked completely by 30 µM HOE 694 (3-methylsulfonyl-4-piperidinobenzoyl, guanidine hydrochloride) a specific NHE inhibitor, or by removing [Na⁺]0. In 3% CO2/HCO3⁻-buffered solution, HOE 694 slowed the pHi recovery from the induced intracellular acidosis only, while adding together with DIDS (a specific NBC inhibitor) or removal of [Na⁺]0 entirely inhibited the acid extrusion. Moreover, α-cyano-4-hydroxycinnamate (CHC; a specific blocker of MCT) blocked the lactate-induced pHi changes. In conclusion, we demonstrate, for the first time, that 3 different pHi regulators responsible for acid extruding, i.e. NHE and NBC, and MCT, are functionally co-existed in cultured HRASMCs.

Lycopene Inhibits Urotensin-II-Induced Cardiomyocyte Hypertrophy in Neonatal Rat Cardiomyocytes.

This study investigated how lycopene affected urotensin-II- (U-II-) induced cardiomyocyte hypertrophy and the possible implicated mechanisms. Neonatal rat cardiomyocytes were exposed to U-II (1 nM) either exclusively or following 6 h of lycopene pretreatment (1-10 µ M). The lycopene (3-10 µ M) pretreatment significantly inhibited the U-II-induced cardiomyocyte hypertrophy, decreased the production of U-II-induced reactive oxygen species (ROS), and reduced the level of NAD(P)H oxidase-4 expression. Lycopene further inhibited the U-II-induced phosphorylation of the redox-sensitive extracellular signal-regulated kinases. Moreover, lycopene treatment prevented the increase in the phosphorylation of serine-threonine kinase Akt and glycogen synthase kinase-3beta (GSK-3 ß ) caused by U-II without affecting the protein levels of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN). However, lycopene increased the PTEN activity level, suggesting that lycopene prevents ROS-induced PTEN inactivation. These findings imply that lycopene yields antihypertrophic effects that can prevent the activation of the Akt/GSK-3 ß hypertrophic pathway by modulating PTEN inactivation through U-II treatment. Thus, the data indicate that lycopene prevented U-II-induced cardiomyocyte hypertrophy through a mechanism involving the inhibition of redox signaling. These findings provide novel data regarding the molecular mechanisms by which lycopene regulates cardiomyocyte hypertrophy.

Protection of differentiated neuronal NG108-15 cells from P2X7 receptor-mediated toxicity by taurine.

BACKGROUND: Strong P2X7 receptor (P2X7R) activation causes Ca(2+) overload and consequent cell death. We previously showed that depletion of Ca(2+) stores and endoplasmic reticulum (ER) stress in differentiated NG108-15 neuronal cells contributed to P2X7R-mediated cytotoxicity. In this work, we assessed whether taurine (2-aminoethanesulfonic acid) could prevent this P2X7R-mediated cytotoxicity in this neuronal cell line. METHODS: Cytotoxicity markers were assessed by MTT assay and Western blotting. Cytosolic Ca(2+) and mitochondrial Ca(2+) concentrations were measured microfluorimetrically using fura-2 and rhod-2, respectively. Intracellular reactive oxygen species (ROS) production was assayed by the indicator 2',7'-dichlorodihydrofluorescein diacetate. RESULTS: Selective P2X7R agonist BzATP treatment causes neuronal cell death by causing cytosolic Ca(2+) overload, depletion of Ca(2+) stores, endoplasmic reticulum (ER) stress, and caspase-3 activation (cleaved caspase 3). Remarkably, taurine (10mM) pretreatment could prevent P2X7R-mediated neuronal cell death by blocking BzATP-mediated ER stress as determined by phosphorylated eukaryotic translation initiation factor 2α (peIF2α) and C/EBP-homologous protein (CHOP). However, taurine did not block BzATP-induced Ca(2+) overload and depletion of ER Ca(2+) stores. Interestingly, P2X7R activation did not result in mitochondrial Ca(2+) overload, nor did it affect mitochondrial membrane potential. BzATP-induced generation of intracellular reactive oxygen species (ROS) was prevented by taurine. CONCLUSIONS: The neuroprotective effect by taurine is attributed to the suppression of P2X7R-mediated ER stress and ROS formation.

MicroRNA-328 inhibits renal tubular cell epithelial-to-mesenchymal transition by targeting the CD44 in pressure-induced renal fibrosis.

Epithelial-mesenchymal transition (EMT) occurs in stressed tubular epithelial cells, contributing to renal fibrosis. Initial mechanisms promoting EMT are unknown. Pressure force is an important mechanism contributing to the induction and progression of renal fibrogenesis in ureteric obstruction. In our study of cultured rat renal tubular cells (NRK-52E) under 60 mmHg of pressure, we found that the epithelial marker E-cadherin decreased and mesenchymal markers, e.g., α-smooth muscle actin, fibronectin and Snail, increased. Pressure also induced the expression of connective tissue growth factor and transforming growth factor-ß. MicroRNA array assays showed that pressure reduced miR-328 at the initial stage of pressurization. We identified a potential target sequence of miR-328 in rat CD44 3'-untranslated regions. In contrast with the miR-328 expression, CD44 expression was up-regulated at the initial pressurization stage. We also found that miR-328 expression decreased and CD44 increased in ureteric obstruction kidneys in the animal study. CD44 siRNA transfection significantly increased E-cadherin expression and inhibited pressure-induced EMT. Both hyaluronan binding peptide pep-1 and osteopontin neutralizing antibody inhibited pressure-induced EMT. Our results suggest that miR-328-mediated CD44 transient upregulation is an important trigger of the pressure-induced EMT in renal fibrosis.

Influenza vaccination reduces hospitalization for acute coronary syndrome in elderly patients with chronic obstructive pulmonary disease: a population-based cohort study.

BACKGROUND: Elderly patients with chronic obstructive pulmonary disease (COPD) are at a higher risk of hospitalization for cardiovascular complications, especially during respiratory infections. Previous studies showed that vaccination for influenza may reduce the risk of recurrent major cardiovascular events in patients with acute coronary syndrome (ACS). The purpose of this study was to evaluate the hypothesis that influenza vaccination could reduce hospitalizations for ACS in elderly patients with COPD. METHOD: Using the Taiwan Longitudinal Health Insurance Database 1996-2008, this cohort study comprised elderly patients (≥ 55 years old) with a recorded diagnosis of COPD (n=7722) between January 1, 2000 and December 31, 2007. Each patient was followed until the end of 2007. A propensity score was derived by using a logistic regression model to reduce vaccine therapy selection bias. The hazard ratio (HR) and 95% confidence interval (CI) for the association between the influenza vaccination and the occurrence of first hospitalization for ACS in elderly COPD patients was examined by Cox proportional hazards regression analysis. In addition, we categorized the patients into four groups according to vaccination status (unvaccinated, total number of vaccinations: 1, 2-3, and ≥ 4). RESULTS: We found that elderly patients with COPD receiving influenza vaccination had a lower risk of hospitalization for ACS (adjusted HR=0.46, 95% CI (0.39-0.55), p < 0.001). We observed similar protective effects in both sexes and all age groups (55-64, 65-74, ≥ 75) regardless of influenza seasonality. When the patients were stratified according to the total number of vaccinations, the adjusted HRs for hospitalization because of ACS were 0.48 (0.38-0.62) and 0.20 (0.14-0.28) for patients who received 2-3 and ≥ 4 vaccinations during the follow-up period. CONCLUSION: Our data showed that there was a lower risk of ACS hospitalization in elderly patients with COPD receiving annual influenza vaccination.

Antiarrhythmic effects of dehydroevodiamine in isolated human myocardium and cardiomyocytes.

ETHNOPHARMACOLOGICAL RELEVANCE: Dehydroevodiamine alkaloid (DeHE), a bioactive component of the Chinese herbal medicine Wu-Chu-Yu (Evodiae frutus), exerted antiarrhythmic effect in guinea-pig ventricular myocytes. We further characterize the electromechanical effects of DeHE in the human atrial and ventricular tissues obtained from hearts of patients undergoing corrective cardiac surgery or heart transplantation. MATERIALS AND METHODS: The transmembrane potentials of human myocardia were recorded with a traditional microelectrode technique while sarcolemmal Na(+) and Ca(2+) currents in single human cardiomyocytes were measured by a whole-cell patch-clamp technique. The intracellular pH (pHi) and Na(+)-H(+) exchanger (NHE) activity were determined using BCECF-fluorescence in human atria. RESULTS: In human atria, DeHE (0.1-0.3 µM) depressed upstroke velocity, amplitude of action potential, and contractile force, both in slow and fast response action potential. Moreover, the similar depressant effects of DeHE were found in human ventricular myocardium. Both in isolated human atrial and ventricular myocytes, DeHE (0.1-1 µM) reversibly, concentration-dependently decreased the Na(+) and Ca(2+)currents. Moreover, DeHE (0.1 and 0.3 µM) suppressed delayed afterdepolarizations and aftercontractions, induced by epinephrine and high [Ca(2+)]o in atria. In human ventricular myocardium, the strophanthidin-induced triggered activities were attenuated by pretreating DeHE (0.3 µM). The resting pHi and NHE activity were also significantly increased by DeHE (0.1-0.3 µM). CONCLUSIONS: We concluded for the first time that, in the human hearts, DeHE could antagonize triggered arrhythmias induced by cardiotonic agents through a general reduction of the Na(+) and Ca(2+) inward currents, while increase of resting pHi and NHE activity.

Intracellular Acid-extruding regulators and the effect of lipopolysaccharide in cultured human renal artery smooth muscle cells.

Homeostasis of the intracellular pH (pHi) in mammalian cells plays a pivotal role in maintaining cell function. Thus far, the housekeeping Na(+)-H(+) exchanger (NHE) and the Na(+)-HCO3(-) co-transporter (NBC) have been confirmed in many mammalian cells as major acid extruders. However, the role of acid-extruding regulators in human renal artery smooth muscle cells (HRASMCs) remains unclear. It has been demonstrated that lipopolysaccharide (LPS)-induced vascular occlusion is associated with the apoptosis, activating calpain and increased [Ca(2+)]i that are related to NHE1 activity in endothelia cells. This study determines the acid-extruding mechanisms and the effect of LPS on the resting pHi and active acid extruders in cultured HRASMCs. The mechanism of pHi recovery from intracellular acidosis (induced by NH4Cl-prepulse) is determined using BCECF-fluorescence in cultured HRASMCs. It is seen that (a) the resting pHi is 7.19 ± 0.03 and 7.10 ± 0.02 for HEPES- and CO2/HCO3(-)- buffered solution, respectively; (b) apart from the housekeeping NHE1, another Na(+)-coupled HCO3(-) transporter i.e. NBC, functionally co-exists to achieve acid-equivalent extrusion; (c) three different isoforms of NBC: NBCn1 (SLC4A7; electroneutral), NBCe1 (SLC4A4; electrogenic) and NBCe2 (SLC4A5), are detected in protein/mRNA level; and (d) pHi and NHE protein expression/activity are significantly increased by LPS, in both a dose- and time- dependent manner, but NBCs protein expression is not. In conclusion, it is demonstrated, for the first time, that four pHi acid-extruding regulators: NHE1, NBCn1, NBCe1 and NBCe2, co-exist in cultured HRASMCs. LPS also increases cellular growth, pHi and NHE in a dose- and time-dependent manner.

Urotensin II induces interleukin 8 expression in human umbilical vein endothelial cells.

BACKGROUND: Urotensin II (U-II), an 11-amino acid peptide, exerts a wide range of actions in cardiovascular systems. Interleukin-8 (IL-8) is secreted by endothelial cells, thereby enhancing endothelial cell survival, proliferation, and angiogenesis. However, the interrelationship between U-II and IL-8 as well as the detailed intracellular mechanism of U-II in vascular endothelial cells remain unclear. The aim of this study was to investigate the effect of U-II on IL-8 expression and to explore its intracellular mechanism in human umbilical vein endothelial cells. METHODS/PRINCIPAL FINDINGS: Primary human umbilical vein endothelial cells were used. Expression of IL-8 was determined by real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and luciferase reporter assay. Western blot analyses and experiments with specific inhibitors were performed to reveal the downstream signaling pathways as concerned. U-II increased the mRNA/protein levels of IL-8 in human umbilical vein endothelial cells. The U-II effects were significantly inhibited by its receptor antagonist [Orn(5)]-URP. Western blot analyses and experiments with specific inhibitors indicated the involvement of phosphorylation of p38 mitogen-activated protein kinase and extracellular signal-regulated kinase in U-II-induced IL-8 expression. Luciferase reporter assay further revealed that U-II induces the transcriptional activity of IL-8. The site-directed mutagenesis indicated that the mutation of AP-1 and NF-kB binding sites reduced U-II-increased IL-8 promoter activities. Proliferation of human umbilical vein endothelial cells induced by U-II could be inhibited significantly by IL-8 RNA interference. CONCLUSION/SIGNIFICANCE: The results show that U-II induces IL-8 expression in human umbilical vein endothelial cells via p38 mitogen-activated protein kinase and extracellular signal-regulated kinase signaling pathways and IL-8 is involved in the U-II-induced proliferation of human umbilical vein endothelial cells.