Proteome analysis of sorbitol fermentation specific protein in Vibrio cholerae by 2-DE and MS

Vibrio cholerae can be differentiated into epidemic and non-epidemic strains by sorbitol fermentation speed, but little research has been done on its mechanisms. In this study, we investigated differential protein expression of the two strains in response to sorbitol metabolism. V. cholerae strains were cultured in media with and without sorbitol, respectively. Proteins were separated by 2-DE, and those that showed different expression in the two media were identified by MALDI-TOF MS. Fifteen proteins in epidemic strains and 11 proteins in non-epidemic strains showed a different expression in sorbitol medium. Among them, 4 proteins were common to epidemic and non-epidemic strains. Gene sequence analysis showed that some mutations occurred in these proteins between the two strains. Potential functions of these proteins included sugar uptake, amino acid uptake, electron transport, sulfate and thiosulfate transport.     

The diversity of mycorrhizal fungi in Japanese Cephalanthera species

The diversity of mycorrhizal fungi among four Japanese Cephalanthera (Orchidaceae) species was examined at a total of seven sites, based on sequence variation in nuclear ribosomal DNA. This is the first report to detect mycorrhizal fungi in C. subaphylla. Two patterns of mycorrhizal associations were confirmed from our results. C. falcata has lower fungal specificity, associating with Russulaceae, Sebacinales and Thelephoraceae. By contrast, the three Cephalanthera species C. erecta, C. subaphylla, and C. longifolia were associated mainly with Thelephoraceae fungi. There is no large difference found in mycobionts between green and albino individuals of C. falcata and no distinct preference of Japanese Cephalanthera species for a specific fungal group of Thelephoraceae.     

Aerobic exercise training reduces plasma endothelin-1 concentration in older women.

Endothelial function deteriorates with aging. On the other hand, exercise training improves the function of vascular endothelial cells. Endothelin-1 (ET-1), which is produced by vascular endothelial cells, has potent constrictor and proliferative activity in vascular smooth muscle cells and, therefore, has been implicated in regulation of vascular tonus and progression of atherosclerosis. We previously reported significantly higher plasma ET-1 concentration in middle-aged than in young humans, and recently we showed that plasma ET-1 concentration was significantly decreased by aerobic exercise training in healthy young humans. We hypothesized that plasma ET-1 concentration increases with age, even in healthy adults, and that lifestyle modification (i.e., exercise) can reduce plasma ET-1 concentration in previously sedentary older adults. We measured plasma ET-1 concentration in healthy young women (21-28 yr old), healthy middle-aged women (31-47 yr old), and healthy older women (61-69 yr old). The plasma level of ET-1 significantly increased with aging (1.02 +/- 0.08, 1.33 +/- 0.11, and 2.90 +/- 0.20 pg/ml in young, middle-aged, and older women, respectively). Thus plasma ET-1 concentration was markedly higher in healthy older women than in healthy young or middle-aged women (by approximately 3- and 2-fold, respectively). In healthy older women, we also measured plasma ET-1 concentration after 3 mo of aerobic exercise (cycling on a leg ergometer at 80% of ventilatory threshold for 30 min, 5 days/wk). Regular exercise significantly decreased plasma ET-1 concentration in the healthy older women (2.22 +/- 0.16 pg/ml, P < 0.01) and also significantly reduced their blood pressure. The present study suggests that regular aerobic-endurance exercise reduces plasma ET-1 concentration in older humans, and this reduction in plasma ET-1 concentration may have beneficial effects on the cardiovascular system (i.e., prevention of progression of hypertension and/or atherosclerosis by endogenous ET-1).     

Na+/Mg2+ transporter acts as a Mg2+ buffering mechanism in PC12 cells

Mg(2+) buffering mechanisms in PC12 cells were demonstrated with particular focus on the role of the Na(+)/Mg(2+) transporter by using a newly developed Mg(2+) indicator, KMG-20, and also a Na(+) indicator, Sodium Green. Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), a protonophore, induced a transient increase in the intracellular Mg(2+) concentration ([Mg(2+)](i)). The rate of decrease of [Mg(2+)](i) was slower in a Na(+)-free extracellular medium, suggesting the coupling of Na(+) influx and Mg(2+) efflux. Na(+) influxes were different for normal and imipramine- (a putative inhibitor of the Na(+)/Mg(2+) transporter) containing solutions. FCCP induced a rapid increase in [Na(+)](i) in the normal solution, while the increase was gradual in the imipramine-containing solution. The rate of decrease of [Mg(2+)](i) in the imipramine-containing solution was also slower than that in the normal solution. From these results, we show that the main buffering mechanism for excess Mg(2+) depends on the Na(+)/Mg(2+) transporter in PC12 cells.     

Pretreatment of corn stover by aqueous ammonia

Corn stover was pretreated with aqueous ammonia in a flow-through column reactor, a process termed ammonia recycled percolation (ARP). This method was highly effective in delignifying of the biomass, reducing the lignin content by 70-85%. Most lignin removal occurred within the first 20 min of the process. Lignin removal by ARP was further confirmed by FTIR analysis and lignin staining. The ARP process solubilized 40-60% of the hemicellulose but left the cellulose intact. The solubilized carbohydrate existed in oligomeric form. Carbohydrate decomposition during the pretreatment was insignificant. Corn stover treated for 90 min exhibited enzymatic digestibility of 99% with 60 FPU/g of glucan enzyme loading, and 92.5% with 10 FPU/g of glucan. The digestibility of ARP treated corn stover was substantially higher than that of alpha-cellulose. The enzymatic digestibility was related with the removal of lignin and hemicellulose, perhaps due to increased surface area and porosity. The SEM pictures indicated that the biomass structure was deformed and its fibers exposed by the pretreatment. The crystallinity index increased with pretreatment reflecting removal of the amorphous portion of biomass. The crystalline structure of the cellulose in the biomass, however, was not changed by the ARP treatment.     

Photo-induced activation of cytochrome P450/reductase fusion enzyme coupled with spinach chloroplasts

Summary Photoactivation of cytochrome P450 monooxygenase was studied using a combination of spinach chloroplasts and yeast microsomes containing rat P4501A1/yeast reductase fusion enzyme. Under illumination, in the reaction mixture, NADP was reduced, transferring electrons to the P450/reductase fusion enzyme to convert 7-ethoxycoumarin to 7-hydroxycoumarin.     

小钻‘白城杨2号’小孢子发生及花粉大小变异

利用醋酸洋红染色压片技术,以温室水培小钻‘白城杨2号’(Populus×xiaozhuanica W.Y.Hsu et Liangcv.‘Baicheng-2’)为材料,对其小孢子发生过程中染色体行为及花粉大小变异进行研究。结果表明:(1)‘白城杨2号’小孢子母细胞减数分裂过程中染色体行为存在一定比例的异常现象,包括终变期单价体、中期Ⅰ染色体提前分离、后期Ⅰ和Ⅱ落后染色体和染色体桥、末期Ⅰ和Ⅱ微核、中期Ⅱ纺锤体定位异常以及胞质分裂异常等,这些异常现象的发生与‘白城杨2号’杂种起源有密切关系。(2)‘白城杨2号’小孢子母细胞减数分裂过程中核仁数目存在动态变化,末期Ⅰ和Ⅱ的子核中最多可看到8个小核仁,可能与杨属树种的多倍体起源有关,其染色体组中可能包含8对具核仁组织者区的染色体。(3)‘白城杨2号’产生空瘪花粉率为3.67%,饱满花粉直径在21.3～52.2μm之间,频率分布总体呈近似高斯分布,0.69%的花粉直径超过37μm,表明其可能产生少量未减数的2n花粉。     

Involvement of ZEB1 and E-cadherin in the invasion of lung squamous cell carcinoma

This study intended to investigate the expression of the ZEB1 and E-cadherin proteins in lung squamous cell carcinoma (LSCC) tissues and to examine the clinicopathological correlation between protein levels and LSCC. RT-PCR and Western blot were used to examine the expression of ZEB1 and E-cadherin mRNAs and proteins in LSCC tissues as well as in adjacent normal tissues, and then analyze the relationship between the clinicopathological characteristics and the expression changes of ZEB1 and E-cadherin mRNAs in LSCC. In addition, RNAi was used to knockdown the expression of the ZEB1 gene in Human HCC827 cells; subsequently, changes in the invasive ability of the resultant cells were studied. The positive rates of ZEB1 and E-cadherin mRNAs in LSCC tissues were 69.2 and 38.5 %, respectively. They differed significantly from the corresponding positive rates in the adjacent normal lung tissues (15.4 and 80.8 %, p < 0.05). There was a negative correlation between the protein levels of ZEB1 and E-cadherin in LSCC tissues (r = -0.714, p < 0.001); in addition, it was found that ZEB1 protein expression in LSCC tissues was significantly higher than that in the neighboring normal lung tissues (p < 0.05), and its expression was also significantly higher in patients with lymph node metastases and distant metastases compared to those patients without metastatic disease (p < 0.05). On the contrary, E-cadherin expression was significantly lower in LSCC tissues than that in the neighboring normal tissue (p < 0.05). It was lower in patients with lymph node metastasis and distant metastasis compared to patients without metastatic disease (p < 0.05). However, the expression of ZEB1 and E-cadherin was independent of gender, age, tumor size, or tumor differentiation level (p > 0.05). Transfection of ZEB1 siRNA into HCC827 cells significantly reduced the ZEB1 protein level (p < 0.01) and significantly elevated E-cadherin levels (p < 0.01). Moreover, significantly less ZEB1 siRNA-transfected cells migrated through Transwell chambers in the LSCC tissue than that in the control groups (untransfected or transfected with control siRNA, p < 0.01). The expression of the ZEB1 gene in LSCC tissues is downregulated with the expression of E-cadherin. On the other hand, the expression of siRNA against ZEB1 promotes E-cadherin expression and suppresses the invasive ability conferred by E-cadherin. In conclusion, our data suggested that overexpression of the ZEB1 gene is possibly associated with the occurrence, development, invasion of LSCC.