Two calcium-dependent protein kinases enhance maize drought tolerance by activating anion channel ZmSLAC1 in guard cells.

Stomatal closure is an important process to prevent water loss in plants response to drought stress, which is finely modulated by ion channels together with their regulators in guard cells, especially the S-type anion channel AtSLAC1 in Arabidopsis. However, the functional characterization and regulation analyses of anion channels in gramineous crops, such as in maize guard cells are still limited. In this study, we identified an S-type anion channel ZmSLAC1 that was preferentially expressed in maize guard cells and involved in stomatal closure under drought stress. We found that two Ca2+ -dependent protein kinases ZmCPK35 and ZmCPK37 were expressed in maize guard cells and localized on the plasma membrane. Lesion of ZmCPK37 resulted in drought-sensitive phenotypes. Mutation of ZmSLAC1 and ZmCPK37 impaired ABA-activated S-type anion currents in maize guard cells, while the S-type anion currents were increased in the guard cells of ZmCPK35- and ZmCPK37-overexpression lines. Electrophysiological characterization in maize guard cells and Xenopus oocytes indicated that ZmCPK35 and ZmCPK37 could activate ZmSLAC1-mediated Cl- and NO3- currents. The maize inbred and hybrid lines overexpressing ZmCPK35 and ZmCPK37 exhibited enhanced tolerance and increased yield under drought conditions. In conclusion, our results demonstrate that ZmSLAC1 plays crucial roles in stomatal closure in maize, whose activity is regulated by ZmCPK35 and ZmCPK37. Elevation of ZmCPK35 and ZmCPK37 expression levels is a feasible way to improve maize drought tolerance as well as reduce yield loss under drought stress.

CALCIUM-DEPENDENT PROTEIN KINASE 32-mediated phosphorylation is essential for the ammonium transport activity of AMT1;1 in Arabidopsis roots.

Protein kinase-mediated phosphorylation modulates the absorption of many nutrients in plants. CALCIUM-DEPENDENT PROTEIN KINASES (CPKs) are key players in plant signaling to translate calcium signals into diverse physiological responses. However, the regulatory role of CPKs in ammonium uptake remains largely unknown. Here, using methylammonium (MeA) toxicity screening, CPK32 was identified as a positive regulator of ammonium uptake in roots. CPK32 specifically interacted with AMMONIUM TRANSPORTER 1;1 (AMT1;1) and phosphorylated AMT1;1 at the non-conserved serine residue Ser450 in the C-terminal domain. Functional analysis in Xenopus oocytes showed that co-expression of CPK32 and AMT1;1 significantly enhanced the AMT1;1-mediated inward ammonium currents. In transgenic plants, the phosphomimic variant AMT1;1S450E, but not the non-phosphorylatable variant AMT1;1S450A, fully complemented the MeA insensitivity and restored high-affinity 15NH4+ uptake in both amt1;1 and cpk32 mutants. Moreover, in the CPK32 knockout background, AMT1;1 lost its ammonium transport activity entirely. These results indicate that CPK32 is a crucial positive regulator of ammonium uptake in roots and the ammonium transport activity of AMT1;1 is dependent on CPK32-mediated phosphorylation.

Silencing lncRNA TUG1 Alleviates LPS-Induced Mouse Hepatocyte Inflammation by Targeting miR-140/TNF.

Hepatitis is a major public health problem that increases the risk of liver cirrhosis and liver cancer. Numerous studies have revealed that long non-coding RNAs (lncRNAs) exert essential function in the inflammatory response of multiple organs. Herein, we aimed to explore the effect of lncRNA TUG1 in LPS-induced hepatocyte inflammation response and further illuminate the underlying mechanisms. Mice were intraperitoneally injected with LPS, and the liver inflammation was evaluated. Microarray showed that lncRNA TUG1 was upregulated in LPS-induced hepatocyte inflammation. qRT-PCR and immunofluorescence assay indicated a significant increase of TUG1 in mice with LPS injection. Functional analysis showed that si-TUG1 inhibited LPS-induced inflammation response in mice liver, inhibited apoptosis level, and protected liver function. Then, we knock down TUG1 in normal human hepatocyte AML12. Consistent with in vivo results, si-TUG1 removed the injury of LPS on AML12 cells. Furthermore, TUG1 acted as a sponge of miR-140, and miR-140 directly targeted TNFα (TNF). MiR-140 or si-TNF remitted the beneficial effects of TUG1 on LPS-induced hepatocyte inflammation response both in vitro and in vivo. Our data revealed that deletion of TUG1 protected against LPS-induced hepatocyte inflammation via regulating miR-140/TNF, which might provide new insight for hepatitis treatment.

Gender impacts on the correlations between nonalcoholic fatty liver disease and hypertension in a Chinese population aged 45-60 y.

No previous study has reported the association between nonalcoholic fatty liver disease (NAFLD) and the risk of hypertension in the Chinese population. Therefore, the aim of this study was to evaluate the relationship between NAFLD and hypertension in a middle-aged Chinese population. The study subject was (a group of) 1006 Chinese adults aged 45-60 y in Shandong Province who participated in the Weifang Nutrition and Health Survey (2014-2015). Hypertension was defined as systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥ 9 0mmHg. NAFLD was defined as the presence of moderate-severe hepatic steatosis (by B-ultrasonic examination), the absence of excessive alcohol use (>20 g/d in men and 10 g/d in women), no use of steatogenic medications within the past six months, no exposure to hepatotoxins, and no history of bariatric surgery. All anthropometric measurements and biochemical data were collected following standard protocols. Multivariate logistic regression analysis was used to identify the association between NAFLD and hypertension with adjustment of potential confounding variables. Body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), fasting glucose, SBP, DBP, triglycerides (TG), serum uric acid (SUA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and the prevalence of hypertension and NAFLD were significantly higher in males than in females (p < 0.05). Females had significantly higher levels of total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C). After adjusting for potential confounders, NAFLD was associated with an increased risk of hypertension in both male and female, with odds ratios (ORs) (95% CI) of 2.152 (1.324-3.498) and 2.133 (1.409-3.229), respectively. CONCLUSIONS: Our findings indicated that NAFLD was significantly associated with the risk of hypertension in males than in females. However, our findings also need to be confirmed in future prospective studies. ABBREVIATIONS: BMI: body mass index; WC: waist circumference; WHR: waist-hip ratio; SBP: systolic blood pressure; DBP: diastolic blood pressure; FG: fasting glucose; TG: triglycerides; TC: total cholesterol; HDL-C: high-density lipoprotein cholesterol; SUA: serum uric acid; NAFLD: nonalcoholic fatty liver disease; LDL-C: low-density lipoprotein cholesterol; OR: odds ratio; CI: confidence interval; ALT: alanine aminotransferase; AST: aspartate aminotransferase.

Protective effects of BAY 73-6691, a selective inhibitor of phosphodiesterase 9, on amyloid-ß peptides-induced oxidative stress in in-vivo and in-vitro models of Alzheimer's disease.

Alzheimer's disease (AD) is accompanied by enhanced oxidative stress and excess free radicals. Phosphodiesterase 9 inhibitors (PDE-9Is) showed memory improving effects in many pharmacological deficit models. However, whether BAY 73-6691 (a selective PDE-9I) may attenuate the oxidative stress during the development of AD is still unclear. For this purpose, primary cultures of SH-SY5Y cells were incubated with 20µM beta-amyloid25-35 (Aß25-35), followed by exposure to different concentrations (50, 100, 150 and 200µg/ml) of BAY 73-6691. Furthermore, the antioxidant effect of BAY 73-6691 was evaluated in mice subjected to intracerebroventricular injection of Aß25-35 (day 0) and treatment with BAY 73-6691 by intraperitoneal injection once daily (days 1-10). Our results elucidated that treatment with BAY 73-6691 attenuated the Aß25-35-induced cytotoxicity and oxidative stress in SH-SY5Y cells. In vivo, BAY 73-6691 protected Aß25-35-induced oxidative damage in hippocampus, associated with the attenuation of impairments in hippocampal neurons. Administration of BAY 73-6691 improved learning and memory in the Morris water maze test, and restored several hippocampal memory-associated proteins. Our study identified a neuroprotective role for BAY 73-6691 against Aß25-35-induced oxidative stress in vivo and in vitro, harboring therapeutic potential for the treatment of AD by alleviating the impairments in spatial memory and hippocampal neurons.

Atorvastatin Treatment for Atrial Fibrillation Reduces Serum High-Sensitivity C-Reactive Protein Levels.

We investigated whether serum hs-CRP levels predict the efficacy of atrial fibrillation (AF) treated with atorvastatin. Bibliographic databases were exhaustively searched for studies relevant to the research topic. Newcastle-Ottawa Scale (NOS) criteria, combined with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS), were applied for study quality assessment. Our meta-analysis identified seven cohort studies (2006~2013), providing information on the change in serum hs-CRP levels in AF patients receiving atorvastatin therapy. After atorvastatin treatment, hs-CRP level in AF patients decreased significantly (SMD = 1.02, 95% CI: 0.58-1.47, P < 0.001). Subgroup analysis by country and hs-CRP detection methods suggested a negative relationship between atorvastatin treatment and hs-CRP levels among Chinese AF patients (SMD = 1.34, 95% CI: 1.00-1.69, P < 0.001) and by using ELISA method (SMD = 1.11, 95% CI: 0.51-1.71, P < 0.001), but not among Turkish population and using INA method (all P > 0.05). Egger's test showed no publication bias (P = 0.450). hs-CRP was clearly lowered in AF patients treated with atorvastatin, which may be helpful in the choice of statin agents for AF treatment. However, longer follow-ups are necessary to assess the clinical value of lowering hs-CRP in the clinical setting of AF treatment outcomes.

Arabidopsis CALCIUM-DEPENDENT PROTEIN KINASE8 and CATALASE3 Function in Abscisic Acid-Mediated Signaling and H2O2 Homeostasis in Stomatal Guard Cells under Drought Stress.

Drought is a major threat to plant growth and crop productivity. Calcium-dependent protein kinases (CDPKs, CPKs) are believed to play important roles in plant responses to drought stress. Here, we report that Arabidopsis thaliana CPK8 functions in abscisic acid (ABA)- and Ca(2+)-mediated plant responses to drought stress. The cpk8 mutant was more sensitive to drought stress than wild-type plants, while the transgenic plants overexpressing CPK8 showed enhanced tolerance to drought stress compared with wild-type plants. ABA-, H2O2-, and Ca(2+)-induced stomatal closing were impaired in cpk8 mutants. Arabidopsis CATALASE3 (CAT3) was identified as a CPK8-interacting protein, confirmed by yeast two-hybrid, coimmunoprecipitation, and bimolecular fluorescence complementation assays. CPK8 can phosphorylate CAT3 at Ser-261 and regulate its activity. Both cpk8 and cat3 plants showed lower catalase activity and higher accumulation of H2O2 compared with wild-type plants. The cat3 mutant displayed a similar drought stress-sensitive phenotype as cpk8 mutant. Moreover, ABA and Ca(2+) inhibition of inward K(+) currents were diminished in guard cells of cpk8 and cat3 mutants. Together, these results demonstrated that CPK8 functions in ABA-mediated stomatal regulation in responses to drought stress through regulation of CAT3 activity.

Protective effects of the p38 MAPK inhibitor SB203580 on NMDA­induced injury in primary cerebral cortical neurons.

The p38 pathway, which is important in mitogen-activated protein kinase (MAPK) family protein signaling, leads to mitochondrial dysfunction and activation of caspase-3. B-cell lymphoma 2 (Bcl­2) family members are involved in the regulation of activities associated with the survival and death of neurons through apoptosis and have important functions in most types of apoptosis. In the present study, the effects of the p38 MAPK inhibitor SB203580 on N-methyl-d-aspartate (NMDA)-induced cerebral cortical neuron apoptosis were observed to further analyze the possible mechanisms of NMDA-induced neuronal death. Cultured primary cortical neurons were randomly divided into five groups: A control group, NMDA group and three SB203580 interventional groups. The lactate dehydrogenase (LDH) and MTT assays were employed to investigate the effects of the drugs on apoptosis. The morphology of apoptotic cells was observed using acridine orange/ethidium bromide (AO/EB) fluorescence staining. The expression levels of phospho­(p)­p38MAPK, Bcl­2 and Bcl-2-associated X (Bax) were assessed by immunohistochemical methods and western blot analysis to investigate the possible underlying protective mechanisms. The cell viability markedly decreased following incubation with NMDA. The protein levels of cell death repressor Bcl-2 and the levels of Bcl-2/Bax were downregulated. The protein levels of p­p38MAPK and cell death promoter Bax increased significantly in cells with NMDA treatment. However, these changes were inhibited by SB203580 treatment, particularly in the high­dose group. Neuronal death induced by NMDA in primary cortical neurons was caused in part by apoptosis, which was mediated through the activation of the p38 signaling pathway by NMDA. SB203580 has neuroprotective effects against NMDA­induced apoptosis.

[Effects of micrometer compound rhizoma coptidis on nuclear factor-kappaB and inflammatory factors in rabbit fed with high lipid diet].

OBJECTIVE: To investigate the effects of the micrometer compound rhizoma coptidis on inflammatory factors and its possible mechanism in rabbit fed with high-lipid food. METHOD: The levels of CRP, IL-1 and TNF-alpha were all determinated by ELISA method. The mRNA and activity of NF-kappaB were determinated by RT-PCR and EMSA, respectively. RESULT: The level of CRP, IL-1 and TNF-alpha were significantly increased by feeding for 16 weeks with high-lipid diet in rabbit. It was significantly increased that the mRNA and the binging activity with DNA of NF-kappaB in thorax aorta of rabbits fed by high-lipid diet, too. The micrometer compound rhizoma coptidis can reverse the effects of high-lipid diet on CRP, IL-1, TNF-alpha and NF-kappaB. CONCLUSION: The micrometer compound rhizoma coptidis can inhibit the expression of inflammatory factor possibly through inhibitting the expression and activity of NF-kappaB.