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The objectives of the present study were to investigate the effect of ANG-(1-7) on the development of cardiac hypertrophy and to identify the intracellular mechanism underlying this action of ANG-(1-7). Blood pressure and heart rate were recorded using radiotelemetry before and after chronic subcutaneous infusion of control (PBS), ANG II, ANG-(1-7), or ANG II + ANG-(1-7) for 4 wk in normotensive rats. Chronic administration of ANG-(1-7) did not affect either basal blood pressure or the ANG II-induced elevation in blood pressure. However, ANG-(1-7) significantly attenuated ANG II-induced cardiac hypertrophy and perivascular fibrosis in these rats. These effects of ANG-(1-7) were confirmed in cultured cardiomyocytes, in which ANG-(1-7) significantly attenuated ANG II-induced increases in cell size. This protective effect of ANG-(1-7) was significantly attenuated by pretreatment with A779 (a Mas receptor antagonist) or Mito-TEMPO (a mitochondria-targeting superoxide scavenger) as well as blockade of Sirt3 (a deacetylation-acting protein) by viral vector-mediated overexpression of sirtuin (Sirt)3 short hairpin (sh)RNA. Western blot analysis demonstrated that treatment with ANG-(1-7) dramatically increased Sirt3 expression. In addition, ANG-(1-7) attenuated the ANG II-induced increase in mitochondrial ROS generation, an effect that was abolished by A779 or Sirt3 shRNA. Moreover, ANG-(1-7) increased FoxO3a deacetylation and SOD2 expression, and these effects were blocked by Sirt3 shRNA. In summary, the protective effects of ANG-(1-7) on ANG II-induced cardiac hypertrophy and increased mitochondrial ROS production are mediated by elevated SOD2 expression via stimulation of Sirt3-dependent deacetylation of FoxO3a in cardiomyocytes. Thus, activation of the ANG-(1-7)/Sirt3 signaling pathway could be a novel therapeutic strategy in the management of cardiac hypertrophy and associated complications. Chronic subcutaneous ANG-(1-7) has no effect on ANG II-induced elevations in blood pressure but significantly attenuates ANG II-induced cardiac hypertrophy and fibrosis by a mitochondrial ROS-dependent mechanism. This protective effect of ANG-(1-7) against the action of ANG II action is mediated by stimulation of sirtuin-3-mediated deacetylation of FoxO3a, which triggers SOD2 expression.

CD34(+) stem/progenitor cells have been identified as a promising cell population for the autologous cell-based therapies in patients with cardiovascular disease. The counter-regulatory axes of renin angiotensin system, angiotensin converting enzyme (ACE)/Ang II/angiotensin type 1 (AT1) receptor and ACE2/Ang-(1-7)/Mas receptor, play an important role in the cardiovascular repair. This study evaluated the expression and vascular repair-relevant functions of these two pathways in human CD34(+) cells. CD34(+) cells were isolated from peripheral blood mononuclear cells (MNCs), obtained from healthy volunteers. Expression of ACE, ACE2, AT1, and angiotensin type 2 and Mas receptors were determined. Effects of Ang II, Ang-(1-7), Norleu(3)-Ang-(1-7), and ACE2 activators, xanthenone (XNT) and diminazene aceturate (DIZE) on proliferation, migration, and adhesion of CD34(+) cells were evaluated. ACE2 and Mas were relatively highly expressed in CD34(+) cells compared with MNCs. Ang-(1-7) or its analog, Norleu(3)-Ang-(1-7), stimulated proliferation of CD34(+) cells that was associated with decrease in phosphatase and tensin homologue deleted on chromosome 10 levels and was inhibited by triciribin, an AKT inhibitor. Migration of CD34(+) cells was enhanced by Ang-(1-7) or Norleu(3)-Ang-(1-7) that was decreased by a Rho-kinase inhibitor, Y-27632. In the presence of Ang II, XNT or DIZE enhanced proliferation and migration that were blocked by DX-600, an ACE2 inhibitor. Treatment of MNCs with Ang II, before the isolation of CD34(+) cells, attenuated the proliferation and migration to stromal derived factor-1α. This attenuation was reversed by apocynin, an NADPH oxidase inhibitor. Adhesion of MNCs or CD34(+) cells to fibronectin was enhanced by Ang II and was unaffected by Ang-(1-7). This study suggests that ACE2/Ang-(1-7)/Mas pathway stimulates functions of CD34(+) cells that are cardiovascular protective, whereas Ang II attenuates these functions by acting on MNCs. These findings imply that activation of ACE2/Ang-(1-7)/Mas axis is a promising approach for enhancing reparative outcomes of cell-based therapies.

The synthesized derivative Ru(bpy)(3) covalently linked CNTs hybrid shows good electrochemical activity and ca. 17 times higher luminescence quantum efficiency than the adsorbed derivative Ru(bpy)(3). The Ru-CNTs based ECL sensor exhibits high stability toward determination of TPA with a detection limit as low as 8.75 pM.

Apelin-13 causes vasoconstriction by acting directly on APJ receptors in vascular smooth muscle (VSM) cells; however, the ionic mechanisms underlying this action at the cellular level remain unclear. Large-conductance Ca2+-activated K+ (BKCa) channels in VSM cells are critical regulators of membrane potential and vascular tone. In the present study, we examined the effect of apelin-13 on BKCa channel activity in VSM cells, freshly isolated from rat middle cerebral arteries. In whole-cell patch clamp mode, apelin-13 (0.001-1 μM) caused concentration-dependent inhibition of BKCa in VSM cells. Apelin-13 (0.1 µM) significantly decreased BKCa current density from 71.25±8.14 pA/pF to 44.52±7.10 pA/pF (n=14 cells, P<0.05). This inhibitory effect of apelin-13 was confirmed by single channel recording in cell-attached patches, in which extracellular application of apelin-13 (0.1 µM) decreased the open-state probability (NPo) of BKCa channels in freshly isolated VSM cells. However, in inside-out patches, extracellular application of apelin-13 (0.1µM) did not alter the NPo of BKCa channels, suggesting that the inhibitory effect of apelin-13 on BKCa is not mediated by a direct action on BKCa. In whole cell patches, pretreatment of VSM cells with LY-294002, a PI3-kinase inhibitor, markedly attenuated the apelin-13-induced decrease in BKCa current density. In addition, treatment of arteries with apelin-13 (0.1 µM) significantly increased the ratio of phosphorylated-Akt/total Akt, indicating that apelin-13 significantly increases PI3-kinase activity. Taken together, the data suggest that apelin-13 inhibits BKCa channel via a PI3-kinase-dependent signaling pathway in cerebral artery VSM cells, which may contribute to its regulatory action in the control of vascular tone.

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Results from experiments on the removal of copper using chemical mechanical polishing ͑CMP͒ by alumina abrasives suspended in deionized water are reported. The experiments were carried out in a benchtop polishing tool using IC1000 perforated pads and SUBA 500 pads. The removal rate was measured over a good range of values of the relative velocity and pressure, and for different values of the abrasive concentration in the slurry. The results support the use of Preston's equation over a limited range of values of the relative velocity and pressure in the case of the IC-1000 pad; however, at larger velocities and pressures, the linear behavior implied in Preston's equation is not observed. At low abrasive concentration, the removal rate increases with increasing concentration, but beyond about 2.5 wt % abrasives, there is little further increase in removal rate. In the case of the SUBA 500 pad, Preston's equation is inadequate for describing the dependence on pressure. It is found that the removal rate is indeed linear with increasing velocity at low to moderate pressures, but is proportional to the square root of pressure and the abrasive concentration.All the experiments were performed using a Struer's LaboPol5-LaboForce3 Polisher. This is a laboratory benchtop system in which the pad, 200 mm in diameter, is mounted on a turntable that can be rotated about its center. The material to be polished, copper, in the form of disks of diameter 23.8 mm, was mounted in a holder that can be pressed against the pad by an applied load. The distance from the center of the pad to that of the disk was 64 mm. The load was varied over a range such that the nominal pressure ͑simply termed pressure hereafter͒ ranged from 0 to 13.3 psi. The disks were held z

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