Pathogen attack sequentially confers pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) after sensing of pathogen patterns and effectors by plant immune receptors, respectively. Reactive oxygen species (ROS) play pivotal roles in PTI and ETI as signaling molecules. Nicotiana benthamiana RBOHB, an NADPH oxidase, is responsible for both the transient PTI ROS burst and the robust ETI ROS burst. Here, we show that RBOHB transactivation mediated by MAPK contributes to R3a/AVR3a-triggered ETI (AVR3a-ETI) ROS burst. RBOHB is markedly induced during the ETI and INF1-triggered PTI (INF1-PTI), but not flg22-tiggered PTI (flg22-PTI). We found that the RBOHB promoter contains a functional W-box in the R3a/AVR3a and INF1 signalresponsive cis-element. Ectopic expression of four phospho-mimicking mutants of WRKY transcription factors, which are MAPK substrates, induced RBOHB, and yeast one-hybrid analysis indicated that these mutants bind to the cis-element. Chromatin immunoprecipitation assays indicated direct binding of the WRKY to the cis-element in plants. Silencing of multiple WRKY genes compromised the upregulation of RBOHB, resulting in impairment of AVR3a-ETI and INF1-PTI ROS bursts, but not the flg22-PTI ROS burst. These results suggest that the MAPK-WRKY pathway is required for AVR3a-ETI and INF1-PTI ROS bursts by activation of RBOHB.
In mouse hippocampal CA1 pyramidal neurons, the activity of synaptic small-conductance Ca2+-activated K+ channels type 2 (SK2 channels) provides a negative feedback on N-methyl-d-aspartate receptors (NMDARs), reestablishing Mg2+ block that reduces Ca2+ influx. The well-established role of NMDARs in ischemia-induced excitotoxicity led us to test the neuroprotective effect of modulating SK2 channel activity following cerebral ischemia induced by cardiac arrest and cardiopulmonary resuscitation (CA/CPR). Administration of the SK channel positive modulator, 1-ethyl-benzimidazolinone (1-EBIO), significantly reduced CA1 neuron cell death and improved CA/CPR-induced cognitive outcome. Electrophysiological recordings showed that CA/CPR-induced ischemia caused delayed and sustained reduction of synaptic SK channel activity, and immunoelectron microscopy showed that this is associated with internalization of synaptic SK2 channels, which was prevented by 1-EBIO treatment. These results suggest that increasing SK2 channel activity, or preventing ischemia-induced loss of synaptic SK2 channels, are promising and novel approaches to neuroprotection following cerebral ischemia.
Background Severe ischemia induces renal injury less frequently in women than men. In this study, cardiac arrest and cardiopulmonary resuscitation were used to assess whether estradiol is renoprotective via an estrogen receptor (ER)-dependent mechanism. Materials and Methods Male and female C57BL/6 and ER gene-deleted mice underwent 10 min of cardiac arrest followed by cardiopulmonary resuscitation. Serum chemistries and renal stereology were measured 24 h after arrest. Results Estrogen did not affect mean arterial pressure, regional renal cortical blood flow, and arterial blood gases. Hence, female kidneys were protected (mean ± SEM: blood urea nitrogen, 65 ± 21 vs.149 ± 27 mg/dl, P = 0.04; creatinine, 0.14 ± 0.05 vs. 0.73 ± 0.16 mg/dl, P = 0.01; volume of necrotic tubules, 7 ± 1% vs. 10 ± 0%, P = 0.04). Estrogen also reduced renal injury. In intact females (n = 5), ovariectomized/vehicle-treated (n = 8), and ovariectomized/estrogen-treated (n = 8) animals, blood urea nitrogen was 65 ± 21, 166 ± 28, and 50 ± 14 mg/dl (P = 0.002); creatinine was 0.14 ± 0.05, 0.74 ± 0.26, and 0.23 ± 0.27 mg/dl (P = 0.014); necrotic tubules were 2.5 ± 0.25%, 12.0 ± 1.9%, and 5.0 ± 1.6% (P = 0.004), respectively. In ER-α and ER-β gene-deleted mice and controls estradiol-reduced functional injury (blood urea nitrogen: estradiol 117 ± 71, vehicle 167 ± 56, P = 0.007; creatinine: estradiol 0.5 ± 0.5, vehicle 1.0 ± 0.4, P = 0.013), but the effect of estradiol was not different between ER-α or ER-β gene-deleted mice. Adding ICI 182,780 to estradiol did not alter injury. Conclusions In women, kidneys were protected from cardiac arrest through estrogen. Estradiol-mediated renoprotection was not affected by ER deletion or blockade. Estradiol is renoprotective after cardiac arrest. The results indicate that estradiol renoprotection is ER-α and ER-β independent.
Summary-The P450 eicosanoids epoxyeicosatrienoic acids (EETs) are produced by cytochrome P450 arachidonic acid epoxygenases and metabolized through multiple pathways, including soluble epoxide hydrolase (sEH). Pharmacological inhibition and gene deletion of sEH protect against ischemia/reperfusion injury in brain and heart, and against hypertension-related end-organ damage in kidney. We tested the hypothesis that sEH gene deletion improves survival, recovery of renal function and pathologic ischemic renal damage following transient whole-body ischemia induced by cardiac arrest (CA) and resuscitation. Mice with targeted deletion of sEH (sEH knockout, sEHKO) and C57Bl/6 wild-type control mice were subjected to 10-min CA, followed by cardiopulmonary resuscitation (CPR). Survival in wild-type mice was 93% and 80% at 10 min and 24 h after CA/CPR (n = 15). Unexpectedly, survival in sEHKO mice was significantly lower than WT. Only 56% of sEHKO mice survived for 10 min (n = 15, p = 0.014 compared to WT) and no mice survived for 24 h after CA/CPR (p < 0.0001 versus WT). We conclude that sEH plays an important role in cardiovascular regulation, and that reduced sEH levels or function reduces survival from cardiac arrest.
Male animals exhibit greater neuronal damage following focal cerebral ischemic injury in many experimental injury models, however the mechanism of this is unknown. This study used cardiac arrest and cardiopulmonary resuscitation (CA/CPR) in male mice exposed to physiological vs. pharmacological doses of testosterone and tested the hypothesis that testosterone increases damage following global cerebral ischemia. Analysis of histological damage 72 hrs after resuscitation revealed a complex dose-response curve for testosterone, such that low and high doses of testosterone exacerbated ischemic neuronal damage, while intermediate doses had no effect on neuronal survival. In agreement with these histological observations of neuronal damage, both low and high doses of testosterone increased sensorimotor deficit following CA/CPR compared to vehicle treated animals. Finally, the androgen receptor antagonist flutamide inhibited the increase in neuronal damage and sensorimotor impairment observed in testosterone treated mice. Our data showed that low and supra-physiological levels of testosterone increase neuronal damage following global cerebral ischemia and that blockade of androgen receptors limits this injury. Therefore, this study indicated that testosterone may have a role in determining sex-linked differences in cerebrovascular disease as well as having important health implications in clinical conditions of elevated testosterone.
The Al2O3/InAlN interface formed by atomic layer deposition on a sufficiently thick silicon-doped InAlN layer lattice matched to GaN was investigated electrically. A metal-oxide-semiconductor (MOS) diode fabricated through careful interface formation showed a minimized leakage current and a capacitance-voltage (C-V) characteristic with a capacitance change large enough to evaluate the interface-state density, in the range of 10(12) eV(-1) cm(-2), near the conduction band. However, the MOS diode with careless interface formation resulted in degraded electrical characteristics, which indicated the process dependence of the interface properties. The effects of the acceptor-like interface states on the C-V curves are discussed. (C) 2013 AIP Publishing LLC
We proposed and fabricated multiscale transparent arteriole and capillary vessel models with circular cross sections of 10-500 m using photolithography. The circularities of the fabricated 10, 50, and 500 m diameter microchannels were 84.0%, 61.5%, and 82.3%, respectively. Next, we connected these different models to realize a circulation type blood vessel model simulating arteriole networks. We proposed a novel connection method using an intermediate connector made of wax, which we used to connect these models to make a circulation model. In flow experiments, the fabricated models showed no leakage and circulation models with seamless connections were achieved.
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