The significant effect of chronic intermittent hypoxia on prostaglandin D2 biosynthesis in rat brain.

Obstructive sleep apnea (OSA) is a common disorder characterized by chronic intermittent hypoxia (CIH). Excessive daytime sleepiness (EDS) is one of severe complications frequently associated with OSA. Lipocalin-type prostaglandin synthase (L-PGDS) is potentially responsible for the production of prostaglandin D2 (PGD2) which is an endogenous sleep inducer. To date, whether the content of PGD2 and PGDS is related to intermittent hypoxia has never been reported. The aim of this study was to compare the content of PGD2 and L-PGDS in rats' brains with and without intermittent hypoxia. Adult male Wistar rats (n = 48; 8-10 weeks) were averagely divided into two groups. One was control group, and the other group was exposed to IH (12 h/day for 6 weeks). In each group there are four time-points including 0, 2, 4 and 6 weeks, and six rats were killed and studied at each time-point. At the end of 0, 2, 4 and 6 weeks, the concentrations of PGD2 in brains were measured by LC-MS/MS. In addition, the expressions of L-PGDS protein and mRNA in brains were investigated by western blotting and real-time polymerase chain reaction (RT-PCR), respectively. The results showed the concentrations of PGD2 in CIH rat brains were higher than those in control groups from the second week. At the end of 6 weeks, the concentrations of PGD2 in CIH and control groups were 11.1 and 5.9 ng/g, respectively. The levels of L-PGDS protein and mRNA followed the same trend during the whole 6 weeks. The results will provide a new idea to explore that patients with OSA are always accompanied by excessive daytime sleepiness.

Early Growth Response Protein-1 Involves in Transforming Growth factor-ß1 Induced Epithelial-Mesenchymal Transition and Inhibits Migration of Non-Small-Cell Lung Cancer Cells.

The zinc finger transcription factor EGR1 has a role in controlling synaptic plasticity, wound repair, female reproductive capacity, inflammation, growth control, apoptosis and tumor progression. Recent studies mainly focused on its role in growth control and apoptosis, however, little is known about its role in epithelial-mesenchymal transition (EMT). Here, we aim to explore whether EGR 1 is involved in TGF-ß1-induced EMT in non-small- cell lung cancer cells. Transforming growth factor (TGF)-ß1 was utilized to induce EMT in this study. Western blotting, RT-PCR, and transwell chambers were used to identify phenotype changes. Western blotting was also used to observe changes of the expression of EGR 1. The lentivirus-mediated EGR 1 vector was used to increase EGR1 expression. We investigated the change of migration to evaluate the effect of EGR 1 on non-small-cell lung cancer cells migration by transwell chambers. After stimulating with TGF-ß1, almost all A549 cells and Luca 1 cells (Non-small-cell lung cancer primary cells) changed to mesenchymal phenotype and acquired more migration capabilities. These cells also had lower EGR 1 protein expression. Overexpression of EGR 1 gene with EGR 1 vector could decrease tumor cell migration capabilities significantly after adding TGF-ß1. These data showed an important role of EGR 1 in the EMT of non-small-cell lung cancer cells, as well as migration.

Association between genetic polymorphisms in the ADAM33 gene and asthma risk: a meta-analysis.

The aim of this study was to evaluate the associations between the rs3918396 G>A and rs528557 C>G polymorphisms in the disinterring and metalloproteinase domain 33 (ADAM33) gene and asthma risk. We searched CISCOM, CINAHL, Web of Science, PubMed, Google Scholar, EBSCO, Cochrane Library, and CBM databases from inception through August 1st, 2013 without language restrictions. Meta-analysis was performed using the STATA 12.0 software. Crude odds ratios (ORs) with their 95% confidence intervals (95% CI) were calculated. Thirteen case-control studies were included with a total of 7104 asthma patients and 8172 healthy controls. Our meta-analysis results revealed that ADAM33 rs528557 C>G polymorphism was associated with an increased risk of asthma (all p<0.05). However, we found no correlation between the ADAM33 rs3918396 G>A polymorphism and asthma risk (all p>0.05). Subgroup analysis by ethnicity indicated that the ADAM33 rs528557 C>G polymorphism might be strongly associated with an increased risk of asthma among both Caucasian and Asian populations (All p<0.05). No significant association was found between the ADAM33 rs3918396 G>A polymorphism and the risk of asthma among the studied ethnicities (All p>0.05). The present meta-analysis suggests that the ADAM33 rs528557 C>G polymorphism may contribute to susceptibility to asthma. Thus, the ADAM33 rs528557 C>G polymorphism may be utilized as a biomarker for early diagnosis of asthma.

[Expression of high-level cephalosporinase due to mutation in the AmpC attenuator of a clinical Escherichia coli strain].

OBJECTIVE: To study the resistant phenotype of a clinical strain of Escherichia coli and to explore the effect of its attenuator mutation on AmpC expression. METHODS: A clinical strain of Escherichia coli 20022 (ECO20022) resistant to cefoxitin was isolated clinically. The phenotype was examined by three-dimensional methods, isoelectric focusing (IEF), and microdilution method. The regulator genes of ECO20022 were amplified and sequenced, and the difference between them was analyzed by BLAST method. Then the regulator genes were cloned into pCAT3-basic vector (a promoterless reporter gene vector). Microdilution method was used to detect the minimal inhibitory concentration (MIC) of chloramphenicol and ampicillin to this strain with E. coli ATCC25922 as quality control bacterium. ELISA was used to detect the content of chloramphenicol acetyl transferase (CAT). RESULTS: Compared to the standard E. coli K-12, there were four base substitutions, i.e., 22C-T, 26, 27TA-GT, and 32G-A in the attenuator region of ECO20022. Three-dimensional method showed that this strain was high AmpC-producing. IEF found that it produced three beta-lactamases with the values of PI of 5.4, 8.2, and 9.0 respectively. The beta-lactamase with the PI of 9.0 could be inhibited by cloxacillin but not by clavulanate. The strain was resistant to not only most of third generation cephalosporins, but also to cefepime; however it was still susceptible to carbapenem. The secondary structure of the attenuator RNA of ECO20022 was different from the traditional structure of E. coli K-12. The regulator gene was successfully cloned into pCAT3-basic vector and direct and indirect tests indicated that this regulator gene enhanced the CAT expressing level as much as 10 times that of Escherichia coli K-12. CONCLUSION: AmpC attenuator mutation leads to high AmpC expression in Escherichia coli, resulting in a significant rise of resistance level to beta-lactamase and a great menace to clinical antibiotic therapy.