Cytosolic APX2 is a pleiotropic protein involved in H2O2 homeostasis, chloroplast protection, plant architecture and fertility maintenance.

KEY MESSAGE: Rice cytoplasmic APX2 is a pleiotropic protein, densely distributed around chloroplasts. It plays key roles in H2O2 homeostasis and chloroplast protection, and is related to plant architecture and fertility regulation. Ascorbate peroxidases (APXs) catalyze the conversion of H2O2 into H2O. In this report, we systematically investigated the function of cytosolic APX2 using a T-DNA knockout mutant. Loss of OsAPX2 altered rice architecture including shoot height and leaf inclination, resulting in shoot dwarfing, leaf dispersion and fertility decline. Sixty-five differentially expressed proteins were identified in flag leaves of the milk-ripe stage, mainly involved in photosynthesis, glycolysis and TCA cycle, redox homeostasis, and defense. The absence of APX2 severely impacted the stability of chloroplast proteins, and dramatically reduced their expression levels. Subcellular localization showed that APX2 was enriched around each chloroplast to form a high concentration sphere, highlighting chloroplasts as key targets protected by the protein. Accumulation of H2O2 was suppressed in the KO-APX2 mutant, which may benefit from increased CAT activity and functional complementation of APX family members. Unexpectedly, the accumulation of soluble sugar, especially sucrose increased significantly, suggesting that APX2 was involved in regulation of sugar metabolism. Obviously, roles of the cytosolic APX2 are very profound and complex in rice. It can be concluded that the cytosolic APX2 is a pleiotropic protein and an important regulator in ROS homeostasis, chloroplast protection, carbohydrate metabolism as well as plant architecture and fertility maintenance.

Expression of the moss PpLEA4-20 gene in rice enhances membrane protection and client proteins stability.

Green vegetative tissues of the moss Physcomitrella patens possess a powerful ability to tolerate severe drought stress. Proteomics analysis have revealed that a large number of late embryogenesis abundant (LEA) proteins were key players in the drought tolerance of the photosynthetic tissues. PpLEA4-20, a member of the moss LEA protein family, was selected for further function study using an ectopic expression method in rice. Through molecular identification via PCR, southern blotting and TAIL-PCR, we demonstrated that the PpLEA4-20 gene was transformed and inserted into a non-encoded region in chromosome 4 of rice and expressed stably in transgenic rice. Unexpectedly, PpLEA4-20 protein emerged as two high-expressed spots on 2-D gels generated from transgenic rice, suggesting that PpLEA4-20 proteins are complete compatible and might be modified in rice. Both growth and physiological analysis showed that seedlings of transgenic PpLEA4-20 rice displayed altered phenotypes and tolerance to salt. In addition, electrolyte leakage was reduced in transgenic PpLEA4-20 compared to wild type under stress conditions. Anti-aggregation analysis found that the PpLEA4-20 protein expressed in rice remained soluble at high temperature and in addition to some native proteins from transgenic PpLEA4-20 rice. Based on Nano LC MS/MS analysis, we identified several proteins from transgenic PpLEA4-20 rice of increased heat-stability. Our results provide evidence for a role of PpLEA4-20 in salt tolerance and stabilization of client proteins.

[The association between body composition and bone stiffness in patients with stable chronic obstructive pulmonary disease].

OBJECTIVE: To determine the body composition and bone stiffness in patients with stable chronic obstructive pulmonary disease (COPD), and to explore the association between them. METHODS: Ninety-four male COPD patients in stable conditions and 47 healthy smokers were recruited from March 2013 to January 2014.Lung function, body composition and bone stiffness were measured.In COPD patients, the symptoms were assessed by COPD Assessment Test (CAT) and Modified British Medical Research Council (mMRC) respectively, and the acute exacerbation and hospitalization history in the previous 12 months were also recorded. RESULTS: The prevalence of muscle atrophy (FFMI<16 kg/m(2) ) and high risk of bone fracture (T<-1) were 24.5% and 72.3% respectively in stable male COPD patients. The patients with muscle atrophy, had lower FEV1%pred (39.0 ± 15.2) vs (50.1 ± 16.2), frequent acute exacerbations [1.0(0-3.0) vs 0 (0-1.0)] and lower bone stiffness index (75.5 ± 13.3) vs (85.5 ± 15.7), (test values were 2.904, -1.476, 2.728, all P < 0.05). Compared with patients with low risk of bone fracture(T ≥ -1), patients with high risk of bone fracture (T<-1) showed higher mMRC score [2.0(1.0-3.0) vs 1.0(0-2.0)] (Z = -2.297, P < 0.05). The FFMI correlated positively with SI (r = 0.294, P = 0.004) in COPD patients. CONCLUSIONS: Patients with stable COPD presented worse lung function and increased risk of future exacerbations when combined with muscle atrophy and high risk of bone fracture, and the two co-morbidities were correlated and should be assessed.

Evaluation of nutritional value, bioactivity and mineral content of quinoa bran in China and its potential use in the food industry.

Quinoa bran is a by-product during quinoa processing, which is not well used due to its high content of antinutritional factors. The nutritional, antinutritional, antioxidative and mineral content were analyzed in quinoa bran from five producing areas (Hebei, Shanxi, Qinghai, Inner Mongolia and Gansu Province) in China. The results showed that the mean values of protein, starch, fat, fiber, reducing sugar, ash, moisture and energy in quinoa bran were 9.35%, 47.37%, 8.26%, 10.74%, 3.68%, 6.25%, 9.29% and 360.2 kcal/100 g, respectively. Although the protein content in quinoa bran is lower than that in quinoa grain, it is comparable to that in other grains (rice, corn, millet and sorghum) and brans (wheat, oat and rice), so it has the commercial potential to be processed into animal feed or other edible food. The contents of antioxidant flavonoids (460.9 mg/100g) and polyphenols (477.8 mg/100 g) in quinoa bran were higher than those in quinoa grain, suggesting that quinoa bran had better antioxidant capacity. The contents of saponins, tannins and phytic acid in quinoa bran were 18.65, 0.30 and 0.73%, respectively. The content of saponins was nearly one times higher than that in quinoa grain, the contents of tannins and phytic acid, however, were lower than those in quinoa grain. Therefore, the removal of saponins is the key to eliminate the antinutritional properties of quinoa bran. The contents of macroelements (sodium, potassium, calcium, magnesium, phosphorus) and microelements (iron, manganese, copper, zinc, cobalt, molybdenum, selenium, barium) in quinoa bran were generally higher than those in quinoa grain, which was consistent with the results of ash determination. In summary, quinoa bran was found to be a rich source of nutritional and bioactive components and minerals. If the antinutritional problem can be overcome, quinoa bran has great potential for application in the food industry.

Structural characterization and partial properties of dextran produced by Leuconostoc mesenteroides RSG7 from pepino.

Exopolysaccharides (EPSs) produced by lactic acid bacteria possess various bioactivities and potential attractions for scientific exploration and commercial development. An EPS-producing bacterial strain, RSG7, was previously isolated from the pepino and identified as Leuconostoc mesenteroides. Based on the analyses of high-performance size exclusion chromatography, high-performance ion chromatography, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and methylation, the RSG7 EPS was identified as a dextran with a molecular weight of 5.47 × 106 Da and consisted of α-(1→6) glycosidic linkages as backbone and α-(1→2), α-(1→3), α-(1→4), and α-(1→6) glycosidic linkages as side chains. Scanning electron microscopy observed a honeycomb-like porous structure of RSG7 dextran, and this dextran formed aggregations with irregular hill-shaped lumps according to atomic force microscopy analysis. Physical-chemical investigations suggested that RSG7 dextran possessed excellent viscosity at high concentration, low temperature, and high pH; showed a superior emulsifying capacity of tested vegetable oils than that of hydrocarbons; and owned the maximal flocculating activity (10.74 ± 0.23) and flocculating rate (93.46 ± 0.07%) in the suspended solid of activated carbon. In addition, the dextran could coagulate sucrose-supplemented milk and implied potential probiotics in vitro. Together, these results collectively describe a valuable dextran with unique characteristics for exploitation in food applications.

Characteristics of starch from rice seeds modified by T-DNA insertion of ascorbate peroxidase 2.

Starch is the main storage carbohydrate in rice seed. The amylose and amylopectin content differ among varieties. A transgenic rice line was obtained by T-DNA insertion of ascorbate peroxidase 2 (apx2), resulting in decrease of thousand kernel weight. In this study, starches were isolated from apx2 and wild type seeds. Morphology, physical and chemical properties of starch granules were analyzed. The seed micro-surface in apx2 showed distinct textures, compared with that of wild type. The morphology of starch granules in apx2 exhibited irregular shapes, while the wild type starch granules presented regular polyhedral shapes. Additionally, the length and width of starch granules in apx2 were significantly decreased, compared with that of wild type. Further analysis found that apx2 starch showed low crystallinity and high amylose with the methods of X-ray diffraction pattern, iodine binding and blue value analysis, fourier transform infrared (FT-IR) spectrum and thermogravimetric investigation. This study broadened our knowledge of relationship between antioxidant enzyme and rice seed starch formation.

[Airway inflammation and peripheral airway function in asthmatic patients with different control levels].

OBJECTIVE: To observe the airway inflammation and peripheral airway function in asthmatic patients with different control levels, and to investigate whether the airway inflammation profile detected by induced sputum reflects the peripheral airway dysfunction. METHODS: The recruited asthmatic subjects (n = 66) were divided into 3 groups: asthma controlled (8 male and 13 female), asthma partly controlled (12 male and 16 female), asthma uncontrolled (6 male and 11 female). Twenty healthy subjects served as the control group (9 male and 11 female). On the 1(st) day, all the subjects were required to take asthma control test (ACT), and to receive measurement of lung function by oscillometry and spirometry as well as inflammatory cell profile of induced sputum and the concentration of eosinophil cationic protein (ECP). Exhaled nitric oxide (FE(NO)) was measured on the 2(nd) day, and oscillometry methacholine provocation was conducted for patients whose baseline FEV(1) was > or = 70% predicted. The provocation process was terminated when airway resistance was increased by twice of the basic value, or when the methacholine reached the highest concentration. Then airway resistance and lung function were examined after 3 minutes. Finally, airway resistance and lung function were measured again after the subjects had 5 consecutive deep inspirations (DI). Correlation analysis was conducted between ACT scores and inflammatory cells count, ECP concentrations of induced sputum and FE(NO) among different groups. The correlations were also made between the change of peripheral airway resistance triggered by provocation or DI and ACT scores, total eosinophil, ECP level of induced sputum, FE(NO) respectively. RESULTS: The total eosinophil count and ECP level in induced sputum and FE(NO) in asthmatic patients increased with the decline of control level. Negative correlations between ACT scores and total eosinophil count as well as the ECP level were observed (r = -0.43, -0.56, P < 0.01). In the healthy control group, the percentage of increase in peripheral airway resistance (R(5)-R(20)) and central airway resistance (R(20)) did not show significant difference (F = 3.472, P > 0.05) with methacholine provocation, while the percentage of increase in R(5)-R(20) was greater than in R(20) in both controlled and partly controlled asthmatic patients with provocation (F = 18.09 and 14.14, P < 0.01), though the change of R(5)-R(20) showed no correlations with ACT scores, eosinophil count of induced sputum, ECP level and FE(NO). After DI, R(5)-R(20) decreased from (0.13 +/- 0.14) kPa x L(-1) x s(-1) to (0.08 +/- 0.09) kPa x L(-1) x s(-1) (t = 2.84, P < 0.05) in the healthy control group, while R(5)-R(20) increased from (0.24 +/- 0.15) kPa x L(-1) x s(-1) to (0.30 +/- 0.16) kPa x L(-1) x s(-1) in the controlled asthma group, from (0.31 +/- 0.18) kPa x L(-1) x s(-1) to (0.39 +/- 0.17) kPa x L(-1) x s(-1) in the partly controlled asthma group (t = 3.90 and 4.68, P < 0.01, respectively). No correlations were observed between the change of R(5)-R(20) after DI and ACT scores, total eosinophil counts, ECP level as well as FE(NO) (r = -0.07, 0.28, -0.14, 0.14, P > 0.05). CONCLUSIONS: Even in asthma patients with controlled disease, eosinophilic inflammation in the airway was still present, and the eosinophilic inflammation became more severe with the decline of control level. Bronchodilatory effect caused by DI disappeared in asthmatic patients. The inflammation profile detected by induced sputum did not reflect the dysfunction of peripheral airways.

Comparative analysis of ascorbate peroxidases (APXs) from selected plants with a special focus on Oryza sativa employing public databases.

Reactive oxygen species (ROS) are produced by plants. Hydrogen peroxide (H2O2) is one important component of ROS and able to modulate plant growth and development at low level and damage plant cells at high concentrations. Ascorbate peroxidase (APX) shows high affinity towards H2O2 and plays vital roles in H2O2-scavenging. In order to explore the differences of APXs from selected plant species, bioinformatics methods and public databases were used to evaluate the physicochemical properties, conserved motifs, potential modifications and cis-elements in all the APXs, and protein-protein network and expression profiles of rice APXs. The results suggested that APXs in the selected plant species showed high evolutionary conservation and were able to divide into seven groups, group I to VII. Members in the groups contained abundant phosphorylation sites. Interestingly, group I and VII had only PKC site. Additionally, promoters of the APXs contained abundant stress-related cis-elements. APXs in rice plant were able to interact with dehydroascorbate reductase 2. The eight APXs expressed differently in root, leaf, panicle, anther, pistil and seed. Drought, Pi-free, Cd and Xanthomonas oryzae pv. oryzicola B8-12 treatments were able to significantly alter the expression profiles of rice APXs. This study increases our knowledge to further explore functions and mechanisms of APXs and also guides their applications.

The introduction of electromagnetic navigation bronchoscopy for the diagnosis of small pulmonary peripheral lesions in an Asian population.

BACKGROUND: Electromagnetic navigation bronchoscopy (ENB) is emerging as a useful new technique for diagnosing small pulmonary peripheral lesions (SPPLs). However, the accuracy and efficiency of ENB have not been investigated in Asian populations where the differential diagnoses for SPPLs may be different. To analyze this question, this study included patients who received diagnostic ENB followed by surgery for the excision of SPPLs. METHODS: Consecutive patients referred to the Department of Thoracic Surgery, Shanghai Pulmonary Hospital (Tongji University), between May 2014 and April 2015 were recruited. ENB was used to obtain biopsy tissue and make a diagnosis, which was then confirmed by histopathological examination. RESULTS: The ENB was performed on 84 SPPLs of 78 patients in the study, with four patients having more than one SPPL. It successfully reached and biopsied 81 lesions. The average ENB navigation time was 10.8 minutes (range, 0.5-52 minutes). No mortality occurred, with only two complications (one bleeding and one pneumothorax). The mean diameter of the biopsied SPPLs was 19.0 mm (range, 5.0-30.0 mm). The distance from the sensor probe to the focus was 8.0 mm (range, 1-16 mm). ENB diagnosis had identical results with histopathology examination in 81 lesions (37 lung cancer and 41 non-lung cancer). The sensitivity of ENB was 92.9% (78 out of 84 lesions) in this study. CONCLUSIONS: These data suggested that ENB was an accurate and efficient procedure to sample and diagnose SPPLs in the Asian population. It appeared that ENB had a high percentage of successful results in both navigating and aiding in the diagnosis of SPPLs in the Asian population.

Effects of dynamic hyperinflation on exercise capacity and quality of life in stable COPD patients.

BACKGROUND AND AIMS: Dynamic hyperinflation (DH) is an important pathophysiological characteristic of chronic obstructive pulmonary disease (COPD). There is increasing evidence that DH has negative effects on exercise performance and quality of life. The objective of this study was to explore effects of DH on exercise capacity and quality of life in stable COPD patients. METHODS: Fifty-eight COPD patients and 20 matched healthy individuals underwent pulmonary function test, 6-min walk test and symptom-limited cardiopulmonary exercise test (CPET). End-expiratory lung volume/total lung capacity ratio (EELVmax/TLC) at peak exercise of CPET was evaluated, and EELVmax/TLC ≥ 75% was defined as 'severe dynamic hyperinflation (SDH)'. RESULTS: Of the 58 patients studied, 29 (50.0%) presented with SDH (SDH+ group, EELVmax/TLC 79.60 ± 3.60%), having worse maximal exercise capacity reflected by lower peakload, maximal oxygen uptake (VO2 max), maximal carbon dioxide output (VCO2 max) and maximal minute ventilation (VEmax) than did those without SDH (SDH- group, EELVmax/TLC 67.44 ± 6.53%). The EELVmax/TLC ratio at peak exercise had no association with variables of pulmonary function and 6-min walk distance (6MWD), but correlated inversely with peakload, VO2 max, VCO2 max and VEmax (r = -0.300~-0.351, P < 0.05). Although no significant differences were observed, patients with EELVmax/TLC ≥ 75% tended to have higher COPD assessment test score (15.07 ± 6.55 vs 13.28 ± 6.59, P = 0.303). CONCLUSIONS: DH develops variably during exercise and has a greater impact on maximal exercise capacity than 6MWD, even in those with the same extent of pulmonary function impairment at rest.

Correlation of eosinophil counts in induced sputum and fractional concentration of exhaled nitric oxide and lung functions in patients with mild to moderate asthma.

BACKGROUND: The airway inflammation could be assessed by some noninvasive approaches. To investigate the value of eosinophil counts in induced sputum and fractional concentration of exhaled nitric oxide (FENO) for the regimen adjustment in patients with asthma, the correlation was analyzed between the two parameters and lung function parameter (forced expiratory volume in one second (FEV(1))). METHODS: Sixty-five outpatients with mild to moderate non-exacerbation asthma from Beijing Chao-Yang Hospital were enrolled as treatment group. Combined medications of inhaled corticosteroids plus long-acting beta-2 agonist were administered for one year. Lung function parameters, eosinophil counts in induced sputum, concentration of exhaled nitric oxide and the Asthma Control Test scores were recorded, at regular intervals in the follow-up period. Twenty-one healthy volunteers were enrolled as control group and underwent examination of eosinophil counts in induced sputum, lung function and concentration of exhaled nitric oxide. RESULTS: Sixty-three subjects from treatment group completed follow-up period for one year or longer. Mean FEV(1) value of the 63 subjects was (2.75 ± 0.54) L at baseline, (2.97 ± 0.56) L and (3.07 ± 0.52) L at month 3 and month 6, respectively, and maintained as (3.14 ± 0.51) L in the following six months. Mean FENO decreased from (61 ± 25) parts per billion (ppb) at baseline to (32 ± 19) ppb at month 3 (P < 0.05), and continued to decrease to (22 ± 12) ppb at month 6, the difference being significant when compared to both baseline and control group ((13 ± 8) ppb). Mean eosinophil counts decreased to (0.032 ± 0.011) × 10(6)/ml at month 3, which was significantly different from baseline ((0.093 ± 0.023)×10(6)/ml) and the control group ((0.005 ± 0.003)×10(6)/ml (both P < 0.05). The eosinophil counts in induced sputum correlated positively with concentration of FENO in the first six months (all P < 0.05). The concentration of FENO had a significant negative correlation with FEV(1) value (all P < 0.05) in any time point in the follow-up period. The Asthma Control Test scores were 18 ± 5, 19 ± 7, 23 ± 2, 24 ± 1 and 24 ± 1 at months 1, 3, 6, 9 and 12, respectively, which were significantly different from the score at baseline (14 ± 3) (P < 0.05). The most rapid clinical effect was observed at the second month after treatment. CONCLUSION: Eosinophil counts in induced sputum and FENO are sensitive parameters to detect airway inflammation and may be useful in evaluating the efficacy of treatment and adjusting medication regimens.