NLRs guard metabolism to coordinate pattern- and effector-triggered immunity.

Pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) in plants enable them to respond to pathogens by activating the production of defence metabolites that orchestrate immune responses1-4. How the production of defence metabolites is promoted by immune receptors and coordinated with broad-spectrum resistance remains elusive. Here we identify the deubiquitinase PICI1 as an immunity hub for PTI and ETI in rice (Oryza sativa). PICI1 deubiquitinates and stabilizes methionine synthetases to activate methionine-mediated immunity principally through biosynthesis of the phytohormone ethylene. PICI1 is targeted for degradation by blast fungal effectors, including AvrPi9, to dampen PTI. Nucleotide-binding domain, leucine-rich-repeat-containing receptors (NLRs) in the plant immune system, such as PigmR, protect PICI1 from effector-mediated degradation to reboot the methionine-ethylene cascade. Natural variation in the PICI1 gene contributes to divergence in basal blast resistance between the rice subspecies indica and japonica. Thus, NLRs govern an arms race with effectors, using a competitive mode that hinges on a critical defence metabolic pathway to synchronize PTI with ETI and ensure broad-spectrum resistance.

RRM Transcription Factors Interact with NLRs and Regulate Broad-Spectrum Blast Resistance in Rice.

Nucleotide-binding site leucine-rich repeat (NLR) receptors perceive pathogen effectors and trigger plant immunity. However, the mechanisms underlying NLR-triggered defense responses remain obscure. The recently discovered Pigm locus in rice encodes a cluster of NLRs, including PigmR, which confers broad-spectrum resistance to blast fungus. Here, we identify PIBP1 (PigmR-INTERACTING and BLAST RESISTANCE PROTEIN 1), an RRM (RNA-recognition motif) protein that specifically interacts with PigmR and other similar NLRs to trigger blast resistance. PigmR-promoted nuclear accumulation of PIBP1 ensures full blast resistance. We find that PIBP1 and a homolog, Os06 g02240, bind DNA and function as unconventional transcription factors at the promoters of the defense genes OsWAK14 and OsPAL1, activating their expression. Knockout of PIBP1 and Os06 g02240 greatly attenuated blast resistance. Collectively, our study discovers previously unappreciated RRM transcription factors that directly interact with NLRs to activate plant defense, establishing a direct link between transcriptional activation of immune responses with NLR-mediated pathogen perception.

Proteomic analysis reveals the protective role of exogenous hydrogen sulfide against salt stress in rice seedlings.

Hydrogen sulfide (H2S) is an important gaseous signal molecule which participates in various abiotic stress responses. However, the underlying mechanism of H2S associated salt tolerance remains elusive. In this study, sodium hydrosulfide (NaHS, donor of H2S) was used to investigate the protective role of H2S against salt stress at the biochemical and proteomic levels. Antioxidant activity and differentially expressed proteins (DEPs) of rice seedlings treated by NaCl or/and exogenous H2S were investigated by the methods of biochemical approaches and comparative proteomic analysis. The protein-protein interaction (PPI) analysis was used for understanding the interaction networks of stress responsive proteins. In addition, relative mRNA levels of eight selected identified DEPs were analyzed by quantitative real-time PCR. The result showed that H2S alleviated oxidative damage caused by salt stress in rice seedling. The activities of some antioxidant enzymes and glutathione metabolism were mediated by H2S under salt stress. Proteomics analyses demonstrated that NaHS regulated antioxidant related proteins abundances and affected related enzyme activities under salt stress. Proteins related to light reaction system (PsbQ domain protein, plastocyanin oxidoreductase iron-sulfur protein), Calvin cycle (phosphoglycerate kinase, sedoheptulose-1,7-bisphosphatase precursor, ribulose-1,5-bisphosphate carboxylase/oxygenase) and chlorophyll biosynthesis (glutamate-1-semialdehyde 2,1-aminomutase, coproporphyrinogen III oxidase) are important for NaHS against salt stress. ATP synthesis related proteins, malate dehydrogenase and 2, 3-bisphosphoglycerate-independent phosphoglycerate mutase were up-regulated by NaHS under salt stress. Protein metabolism related proteins and cell structure related proteins were recovered or up-regulated by NaHS under salt stress. The PPI analysis further unraveled a complicated regulation network among above biological processes to enhance the tolerance of rice seedling to salt stress under H2S treatment. Overall, our results demonstrated that H2S takes protective roles in salt tolerance by mitigating oxidative stress, recovering photosynthetic capacity, improving primary and energy metabolism, strengthening protein metabolism and consolidating cell structure in rice seedlings.

[Clinical efficacy and mechanism of total glucosides from white paeony for radioactive liver damage].

To discuss the effects of total glucosides from white paeony on preventing and treating radioactive liver damage, and explore its possible mechanisms. Thirty-six patients with primary hepatic carcinoma from 105th Hospital of Chinese PLA were treated with 3-dimensional conformal radiotherapy and randomly divided into simple irradiation group, total glucosides from white paeony group, and control group. The levels of AST, ALT, HA, LN, PCⅢ, CIV and TGF-ß1 in serum of various groups were determined by using ELISA method. As compared with the simple irradiation group and control group, total glucosides from white paeony could obviously decrease the levels of AST, ALT, HA, LN, PCⅢ, CIV and TGF-ß1(P<0.05, P<0.01). The results showed that the total glucosides from white paeony could effectively prevent and treat radioactive liver damage, and its mechanism might be associated with decreasing the levels of TGF-ß1, and inhibiting the synthesis of collagen synthesis.

Comparative proteomics reveal the impact of OmcA/MtrC deletion on Shewanella oneidensis MR-1 in response to hexavalent chromium exposure.

Hexavalent chromium [Cr(VI)] is a priority pollutant causing serious environmental issues. Microbial reduction provides an alternative strategy for Cr(VI) remediation. The dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1, was employed to study Cr(VI) reduction and toxicity in this work. To understand the effect of membrane cytochromes on Cr(VI) response, a comparative protein profile analysis from S. oneidensis MR-1 wild type and its mutant of deleting OmcA and MtrC (△omcA/mtrC) was conducted using two-dimensional electrophoresis (2-DE) technology. The 2-DE patterns were compared, and the proteins with abundant changes of up to twofold in the Cr(VI) treatment were detected. Using mass spectrometry, 38 and 45 differentially abundant proteins were identified in the wild type and the mutant, respectively. Among them, 25 proteins were shared by the two strains. The biological functions of these identified proteins were analyzed. Results showed that Cr(VI) exposure decreased the abundance of proteins involved in transcription, translation, pyruvate metabolism, energy production, and function of cellular membrane in both strains. There were also significant differences in protein expressions between the two strains under Cr(VI) treatment. Our results suggest that OmcA/MtrC deletion might result in the Cr(VI) toxicity to outer membrane and decrease assimilation of lactate, vitamin B12, and cystine. When carbohydrate metabolism was inhibited by Cr(VI), leucine and sulfur metabolism may act as the important compensatory mechanisms in the mutant. Furthermore, the mutant may regulate electron transfer in the inner membrane and periplasm to compensate for the deletion of OmcA and MtrC in Cr(VI) reduction.

The OsSGS3-tasiRNA-OsARF3 module orchestrates abiotic-biotic stress response trade-off in rice.

Recurrent heat stress and pathogen invasion seriously threaten crop production, and abiotic stress often antagonizes biotic stress response against pathogens. However, the molecular mechanisms of trade-offs between thermotolerance and defense remain obscure. Here, we identify a rice thermo-sensitive mutant that displays a defect in floret development under high temperature with a mutation in SUPPRESSOR OF GENE SILENCING 3a (OsSGS3a). OsSGS3a interacts with its homolog OsSGS3b and modulates the biogenesis of trans-acting small interfering RNA (tasiRNA) targeting AUXIN RESPONSE FACTORS (ARFs). We find that OsSGS3a/b positively, while OsARF3a/b and OsARF3la/lb negatively modulate thermotolerance. Moreover, OsSGS3a negatively, while OsARF3a/b and OsARF3la/lb positively regulate disease resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo) and the fungal pathogen Magnaporthe oryzae (M. oryzae). Taken together, our study uncovers a previously unknown trade-off mechanism that regulates distinct immunity and thermotolerance through the OsSGS3-tasiRNA-OsARF3 module, highlighting the regulation of abiotic-biotic stress response trade-off in plants.

Exogenous hydrogen sulfide mediates Na+ and K+ fluxes of salt gland in salt-secreting mangrove plant Avicennia marina.

Hydrogen sulfide (H2S), is a crucial biological player in plants. Here, we primarily explored the interaction between sodium hydrosulfide (NaHS, a H2S donor) and the fluxes of Na+ and K+ from the salt glands of mangrove species Avicennia marina (Forsk.) Vierh. with non-invasive micro-test technology (NMT) and quantitative real-time PCR (qRT-PCR) approaches under salinity treatments. The results showed that under 400-mM NaCl treatment, the addition of 200-µM NaHS markedly increased the quantity of salt crystals in the adaxial epidermis of A. marina leaves, accompanied by an increase in the K+/Na+ ratio. Meanwhile, the endogenous content of H2S was dramatically elevated in this process. The NMT result revealed that the Na+ efflux was increased from salt glands, whereas K+ efflux was decreased with NaHS application. On the contrary, the effects of NaHS were reversed by H2S scavenger hypotaurine (HT), and DL-propargylglycine (PAG), an inhibitor of cystathionine-γ-lyase (CES, a H2S synthase). Moreover, enzymic assay revealed that NaHS increased the activities of plasma membrane and tonoplast H+-ATPase. qRT-PCR analysis revealed that NaHS significantly increased the genes transcript levels of tonoplast Na+/H+ antiporter (NHX1), plasma membrane Na+/H+ antiporter (SOS1), plasma membrane H+-ATPase (AHA1) and tonoplast H+-ATPase subunit c (VHA-c1), while suppressed above-mentioned gene expressions by the application of HT and PAG. Overall, H2S promotes Na+ secretion from the salt glands of A. marina by up-regulating the plasma membrane and tonoplast Na+/H+ antiporter and H+-ATPase.

Early Immunoparalysis Was Associated with Poor Prognosis in Elderly Patients with Sepsis: Secondary Analysis of the ETASS Study.

PURPOSE: Although immune dysfunction has been investigated in adult septic patients, early immune status remains unclear. In this study, our primary aim was to assess early immune status in adult patients with sepsis stratified by age and its relevance to hospital mortality. PATIENTS AND METHODS: A post hoc analysis of a multicenter, randomized controlled trial was conducted; 273 patients whose immune status was evaluated within 48 hours after onset of sepsis were enrolled. Early immune status was evaluated by the percentage of monocyte human leukocyte antigen-DR (mHLA-DR) in total monocytes within 48 hours after onset of sepsis and it was classified as immunoparalysis (mHLA-DR ≤30%) or non-immunoparalysis (>30%). Three logistic regression models were conducted to explore the associations between early immunoparalysis and hospital mortality. We also developed two sensitivity analyses to find out whether the definition of early immune status (24 hours vs 48 hours after onset of sepsis) and immunotherapy affect the primary outcome. RESULTS: Of the 181 elderly (≥60yrs) and 92 non-elderly (<60yrs) septic patients, 71 (39.2%) and 25 (27.2%) died in hospital, respectively. The percentage of early immunoparalysis in the elderly was twice of that in the non-elderly patients (32% vs 16%, p=0.006). For the elderly, hospital mortality was higher in the immunoparalysis ones than the non-immunoparalysis ones (53.4% vs 32.5%, p=0.009). But there was no significant difference in hospital mortality between immunoparalysis non-elderly patients and non-immunoparalysis non-elderly ones (33.5% vs 26.0%, p=0.541). By means of logistic regression models, we found that early immunoparalysis was independently associated with increased hospital mortality in elderly, but not in non-elderly patients. Sensitivity analysis further confirmed the definition of early immune status and immunotherapy did not affect the outcomes. CONCLUSION: The elderly were more susceptible to early immunoparalysis after onset of sepsis. Early immunoparalysis was independently associated with poor prognosis in elderly, but not in non-elderly patients.

Elevated nitrogen metabolism and nitric oxide production are involved in Arabidopsis resistance to acid rain.

Acid rain (AR) can induce great damages to plants and could be classified into different types according to the different SO42-/NO3- ratio. However, the mechanism of plants' responding to different types of AR has not been elucidated clearly. Here, we found that nitric-rich simulated AR (N-SiAR) induced less leaves injury as lower necrosis percentage, better physiological parameters and reduced oxidative damage in the leaves of N-SiAR treated Arabidopsis thaliana compared with sulfate and nitrate mixed (SN-SiAR) or sulfuric-rich (S-SiAR) simulated AR treated ones. Of these three types of SiAR, N-SiAR treated Arabidopsis maintained the highest of nitrogen (N) content, nitrate reductase (NR) and nitrite reductase (NiR) activity as well as N metabolism related genes expression level. Nitric oxide (NO) content showed that N-SiAR treated seedlings had a higher NO level compared to SN-SiAR or S-SiAR treated ones. A series of NO production and elimination related reagents and three NO production-related mutants were used to further confirm the role of NO in regulating acid rain resistance in N-SiAR treated Arabidopsis seedlings. Taken together, we concluded that an elevated N metabolism and enhanced NO production are involved in the tolerance to different types of AR in Arabidopsis.

Effect on extrapulmonary sepsis-induced acute lung injury by hemoperfusion with neutral microporous resin column.

The aim of this study was to investigate the effect of neutral microporous resin hemoperfusion on oxygenation improvement, removal of inflammatory cytokines in plasma and bronchoalveolar lavage, and mortality in acute lung injury induced by extrapulmonary sepsis. Forty-six patients with acute lung injury induced by extrapulmonary sepsis were randomized to HA type hemoperfusion treatment (N=25) or standard therapy (N=21). Those undergoing hemoperfusion treatment received HA330 hemoperfusion. We measured the plasma and bronchoalveolar lavage concentrations of TNF-α and IL-1, and the following parameters were compared between the control group and the hemoperfusion group on days 0, 3 and 7: lung injury measurements (arterial oxygen tension/fractional inspired oxygen ratio, lung injury score, chest X-ray score); interstitial edema of lung (extravascular lung water). Duration of mechanical ventilation, hospital, 28-day, and intensive care unit mortality were also observed. Patients treated with HA hemoperfusion showed a significant removal of plasma and bronchoalveolar lavage TNF-α and IL-1 over time while in the study. Patients in the HA group also demonstrated not only significant improvement of PaO2 /FiO2 , but also decreased Lung Injury Score and chest X-ray score at days 3 and 7. Furthermore, the measurements of the arterial oxygen tension/fractional inspired oxygen ratio, lung injury score and extravascular lung water (EVLWI) significantly correlated with and the concentration of cytokines in the plasma (all P<0.05). The HA hemoperfusion treatment group had a significant reduction in duration of mechanical ventilation, length of intensive care unit stay, and intensive care unit mortality. Significant removal of inflammatory cytokines from circulation and lung by hemoperfusion treatment using the HA type cartridge may contribute to the improvement of lung injury and intensive care unit outcome in extrapulmonary septic patients.

Dexmedetomidine versus midazolam for the sedation of patients with non-invasive ventilation failure.

OBJECTIVE: To compare the efficacy and safety of sedation with dexmedetomidine vs. midazolam for patients with acute cardiogenic pulmonary edema and hypoxemia during the treatment of non-invasive ventilation (NIV). METHODS: The intensive care unit (ICU) patients treated in our hospital between March 2008 and August 2011 who had acute pulmonary edema and hyoxemia in NIV failure due to patient refusal to continue the NIV sessions (due to discomfort) were enrolled in this study. The patients were divided into two groups by the random numerical table method. They were treated with either midazolam (29 cases) or dexmedetomidine (33 cases). The patients were sedated (Ramsay scale 2-3) by a continuous perfusion of midazolam or dexmedetomidine during the NIV session. Cardiorespiratory and ventilatory parameters, the results of the blood gas analysis, and adverse events were prospectively recorded. The main outcome measure was the percentage of endotracheal intubation during NIV. Secondary endpoints included the duration of non-invasive mechanical ventilation, length of ICU stay, and adverse events. RESULTS: In both groups of patients, the expected sedative scores were obtained. The cardiorespiratory symptoms and signs (oxygenation index, pH value, and respiratory rate) were significantly improved in both groups. In the dexmedetomidine-treated group, the patients had a further decreased percentage of failure of NIV requiring endotracheal intubation (ETI) and a more prolonged mean time to ETI (p=0.042, p=0.024). Furthermore, when compared with the group treated with midazolam, the overall duration of mechanical ventilation and the duration of ICU hospitalization in the group treated with dexmedetomidine were markedly decreased, and weaning from mechanical ventilation was easier (p=0.010, p=0.042). Despite the fact that more dexmedetomidine-treated patients developed bradycardia (18.2% vs. 0, p=0.016), no patients required an intervention or interruption of study drug infusion. Conversely, the incidence of respiratory infections and vomiting was lower in the dexmedetomidine-treated patients (p=0.026, p=0.010). CONCLUSION: Dexmedetomidine led to a more desired level of awaking sedation, shortened the duration of mechanical ventilation and the length of the ICU stay, and further reduced the prevalence of nosocomial infection for NIV sedation in patients with acute cardiogenic pulmonary edema. It appears to provide several advantages and safe control compared with the γ-amino butyric acid (GABA) agonist midazolam.

Removal of humoral mediators and the effect on the survival of septic patients by hemoperfusion with neutral microporous resin column.

The aim of this study is to evaluate the impact of neutral microporous resin hemoperfusion on hemodynamic improvement, removal of inflammatory cytokines, and mortality in critical care patients with severe sepsis. Forty-four patients with severe sepsis or septic shock were randomized to HA type hemoperfusion treatment (N=24) or standard therapy (N=20). Those undergoing hemoperfusion treatment received HA330 hemoperfusion. We measured the plasma concentrations of IL-6 and IL-8 at the start of every hemoperfusion treatment, and the following parameters were compared between the control group and the hemoperfusion group on days 3, 7, and 14: hemodynamics (cardiac index, systemic vascular resistance index, heart rate, and mean arterial pressure); change of hematology and coagulation function; organ function; and the sequential organ failure assessment (SOFA) score. Hospital, 28-day, and ICU mortality were also observed. Patients treated with HA hemoperfusion showed a significant removal of plasma IL-6 and IL-8 over time while in the study. Patients in the HA group also demonstrated significant increases in cardiac index, systemic vascular resistant index, fast withdrawal of vasoactive agents and decreases in heart rate compared with the controls at days 3 and 7. Although there was no significant difference between the groups in organ dysfunction as assessed by SOFA scores from day 0 (baseline) to day 7, significant improvement can be demonstrated in the hemoperfusion group at day 14. There was no significant difference between the groups in 28-day mortality, hospital mortality, or length of hospital stay, but ICU mortality and the length of ICU stay in the HA group were markedly reduced. Hemoperfusion treatment using the HA type cartridge in sepsis is safe and it may improve organ dysfunction, ICU mortality, and shorten the length of ICU stay. Clinical significant removal of inflammatory cytokines such as IL-6 and IL-8 from circulation by hemoperfusion may contribute to improving a patient's outcome in an ICU.

[Comparison of target controlled propofol infusion and sevoflurane inhalational anesthesia in laparoscopic cholecystectomy].

OBJECTIVE: To compare the effects of propofol target controlled infusion (TCI) and sevoflurane inhalational anesthesia on the hemodynamics and postoperative recovery in patients undergoing laparoscopic cholecystectomy. METHODS: Sixty ASA IorII patients scheduled for laparoscopic cholecystectomy were randomized into propofol TCI group (group P) and sevoflurane inhalational anesthesia group (group S). In group P, TCI propofol was maintained after intubation until incision closure with the target concentration at 3 microg/ml. In group S, sevoflurane (end-tidal concentration of 2%) was maintained with oxygen flow rate of 2 L/min until incision closure. Fentanyl and vecuronium were intravenously infused according to the depth of anesthesia during the operation. MAP and HR were measured before anesthesia (T(1)), immediately after intubation (T(2)), at skin incision (T(3)), 10 min after pneumoperitoneum (T(4)) and immediately after completion of the operation (T(5)) respectively. Awake time, postoperative nausea and vomiting of the patients were observed after operation. RESULTS: There was significant difference in MAP and HR at T(4) between the two groups (P<0.05), but not at T(1), T(2), T(3) and T(5) (P>0.05). No significant difference was also found in the awake time between the two groups (P>0.05). The incidence of PONV, however, was significantly lower in group P than in group S (P<0.05). CONCLUSION: Propofol TCI and sevoflurane inhalational anesthesia are all effective in inducing good anesthetic effect, maintaining hemodynamic stability and ensuring rapid recovery, but propofol TCI causes lower incidence of PONV in operations such as laparoscopic cholecystectomy.