miR-506-loaded gelatin nanospheres target PENK and inactivate the ERK/Fos signaling pathway to suppress triple-negative breast cancer aggressiveness.

Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer. Some microRNAs (miRNAs) were abnormally expressed in TNBC, and they are closely related to the occurrence and progression of TNBC. Here, we found that miR-506 was significantly downregulated in TNBC and relatively lower miR-506 expression predicted a poorer prognosis. Moreover, we found that miR-506 could inhibit MDA-MB-231 cell viability, colony formation, migration, and invasion, and suppress the ERK/Fos oncogenic signaling pathway through upregulating its direct target protein proenkephalin (PENK). Therefore, miR-506 was proposed as a nucleic acid drug for TNBC therapy. However, miRNA is unstable in vivo, which limiting its application as a therapeutic drug via conventional oral or injected therapies. Here, a gelatin nanosphere (GN) delivery system was applied for the first time to load exogenous miRNA. Exogenous miR-506 mimic was loaded on GNs and injected into the in situ TNBC animal model, and the miR-506 could achieve sustained and controlled release. The results confirmed that overexpression of miR-506 and PENK in vivo through loading on GNs inhibited in situ triple-negative breast tumor growth and metastasis significantly in the xenograft model. Moreover, we indicated that the ERK/Fos signaling pathway was intensively inactivated after overexpression of miR-506 and PENK both in vitro and in vivo, which was further validated by the ERK1/2-specific inhibitor SCH772984. In conclusion, this study demonstrates that miR-506-loaded GNs have great potential in anti-TNBC aggressiveness therapy.

Mineralization initiation of MC3T3-E1 preosteoblast is suppressed under simulated microgravity condition.

Microgravity decreases the differentiation of osteoblast. However, as this process is multistage and complex, the mechanism by which microgravity inhibits osteoblast differentiation is still unclear. We have previously found that 24 h acute treatment of simulated microgravity (SM) with a random positioning machine (RPM) significantly inhibited the differentiation of preosteoblasts and have explored whether osteoblasts show different response to microgravity condition at other stages, such as the mineralizing-stage. Murine MC3T3-E1 preosteoblasts induced for osteogenic differentiation for seven days were cultured either under normal gravity or SM conditions for 24 h. SM treatment significantly suppressed mineralized nodule formation. Alkaline phosphatase (ALP) activity was dramatically decreased, and the expression of ALP gene was downregulated. Expression of well-known markers and regulators for osteoblasts differentiation, including osteocalcin (OC), type I collagen α1 (Col Iα1), dentin matrix protein 1 (DMP1) and runt-related transcription factor 2 (Runx2), were downregulated. Western blot analysis showed that the phosphorylated extracellular signal-regulated kinase (p-ERK) level was lower under SM condition. Thus, the initiation of osteoblast mineralization is suppressed by SM condition, and the suppression may be through the regulation of ALP activity and the osteogenic gene expression. ERK signaling might be involved in this process. These results are relevant to the decrease of osteoblast maturation and bone formation under microgravity condition.

Pharmacokinetics of sulfamonomethoxine in tongue sole (Cynoglossus semilaevis) after intravenous and oral administration.

The pharmacokinetic profiles of sulfamonomethoxine (SMM) were investigated in flatfish tongue soles in the present study. After a single injection of SMM (40 mg/kg BW) to caudal vein of tongue sole at 20 °C, plasma drug concentration versus time data were best fitted to a three-compartment model, characterized with 0.2, 5.7, and 80.4 h for the half-life (t 1/2) of fast distribution, slow distribution, and elimination, respectively. The apparent volume of distribution was 0.1 L/kg, and the body clearance was 0.03 L/h/kg. After oral administration of SMM (200 mg/kg BW) to tongue soles at 20 °C, plasma drug concentrations were best fitted to a two-compartment model, of which the mean half-life of absorption (t 1/2ka) and elimination (t 1/2ß ) were 1.7 and 95.7 h, respectively. The maximal absorption concentration (C max) was estimated as 58 mg/L at 2.5 h, and the mean systemic bioavailability (F) was 39.5 % in tongue soles after oral administration.

[Model systems for bacterial biofilm research].

Contrast to planktonic cells, biofilms are complex communities of microorganisms that develop on biotic or abiotic surfaces. Most of bacteria can form biofilms under proper conditions. Once biofilm form, the inner bacteria cells often exhibit reduced antibiotic susceptibility than their free-floating counterparts, so conventional methods of killing bacteria, such as antibiotics and disinfections are often ineffective with them. Biofilms may cause huge economic loss in equipment damage, product contamination, energy losses and medical infections. Therefore, bacterial biofilm is evolving as a focal problem and an active area of research. As a relatively new area, the progress of biofilm science depends on the development of a satisfactory set of methods. But the classic methods to study planktonic bacteria cannot fulfill the biofilm research, one for which there are few widely accepted methodological standards. Even though biofilms are complicated physical-chemical-biological systems, experience demonstrates that accessible research methods are feasible. In this paper, the theories, principles, merits and limitations of some methods currently used in bacterial biofilm researches, involving artificial biofilm forming and biofilm measurement, were discussed.

[Eco-hydrological impacts of Three Gorges Reservoir's operation on three outfalls of Chingjiang River]. / 三峡水库运行对长江荆南三口水文和生态的影响.

Based on the measured daily flow prototype sequence of five hydrologic stations in the three outfalls of Chingjiang River from 1990 to 2014, its hydrological characteristics and its changing trend was analyzed by using the Mann-Kendall statistical test and the cumulative anomaly method, while the effect of the operation of the Three Gorges on the variation of the 33 indexes of ecological hydrology was also analyzed by the index system of ecological hydrology and range of variability approach. The results showed an obvious decreasing trend in annual mean discharge with the confidence degree of 95% with a decrease rate of 19% during 1990-2014. The jump point appeared in 2003, with the annual mean discharge being 1981.1 m3·s-1 before 2003 but 1603.25 m3·s-1 after. There was an obvious increase in monthly mean discharge from January to April (the degree of deviation was 1.58, 1.86, 0.83 and 0.62 respectively), an obvious increase in the late May and the early June, a slight decrease in July and August (the degree of deviation was -0.12 and -0.10 respectively), and a significant decrease in October (the degree of deviation was -0.40). There was a great change in annual minimum flows while a slight change in most of the annual maximum flows and a moderate decrease in 1-day and 3-day maximum flow. It also had a great change in duration and frequency of the low-flow pulse and slight change in high-flow pulse.

[Purification and characterization of alginate lyase from marine bacterium Vibrio sp. QY101].

Extracellular alginate lyase secreted by Vibrio sp. QY101, which was isolated from brown algae, was purified to homogeneity by a combination of ammonium sulfate precipitation, DEAE-Sepharose Fast Flow anion-exchange chromatography and Superdex 75 gel filtration chromatography. Its molecular mass was 39 kD as determined by SDS-PAGE analysis. The enzyme had an optimal temperature of 30 degrees for its activity, and was most active at pH 7.5. The thermal and pH stability were 0-30 degrees, and pH 6.5-8.5, respectively. The enzyme activity was stimulated by 0.5 mol/L NaCl, 1.0 mmol/L Ca(2+) or 5.0 mmol/L (Mn(2+), and inhibited by 5.0 mmol/L Ni(2+), 1.0 mmol/L Fe2+) or 1.0 mmol/L EDTA. Preliminary analysis on substrate specificity showed that this alginate lyase had activity on both poly-alpha 1,4-L-guluronate and poly-beta1,4-D-mannuronate substrates.

Cloning, sequence analysis and expression of gene alyVI encoding alginate lyase from marine bacterium Vibrio sp. QY101.

The gene (alyVI) encoding an alginate lyase of marine bacterium Vibrio sp. QY101, which was isolated from a decaying thallus of Laminaria, was cloned using a strategy of combined degenerate PCR and long range-inverse PCR (LR-IPCR), then sequenced and expressed in Escherichia coli. Gene alyVI was composed of a 1014 bp open reading frame (ORF) encoding 338 amino acid residues. The calculated molecular mass of alyVI product is 38.4 kDa, but a signal peptide is cleaved off, leaving a mature protein of 34 kDa. AlyVI was purified from culture supernatants to electrophoretic homogeneity using affinity chromatography. AlyVI was most active at pH 7.5 and 40 degrees C in the presence of 1 mM ZnCl2. A nine-amino-acid consensus region (YXRESLREM), which was only found in polyguluronate lyases, was also observed in the amino-terminal region of AlyVI. However, AlyVI could degrade both M block and G block. These results indicate that a novel alginate lyase-encoding gene has been cloned.

[Relationships between urbanization and water resource utilization in Dongting Lake District of South-central China].

By using analytic hierarchy process and entropy method, the evaluation index system and the response relationship model of comprehensive development level of urbanization and comprehensive development and utilization potential of water resources in Dongting Lake District were constructed, with the key affecting factors, their change characteristics, and response characteristics from 2001 to 2010 analyzed. During the study period, the Dongting Lake District was undergoing a rapid development of urbanization, and at a scale expansion stage. The economic and social development level was lagged behind the population and area increase, and the quality and efficiency of urbanization were still needed to be improved. With the advance of urbanization, the water consumption increased yearly, and the water resources utilization efficiency and management level improved steadily. However, the background condition of water resources and their development and utilization level were more affected by hydrological environment rather than urbanization. To a certain extent, the development of urbanization in 2001, 2002, 2005, 2006, 2007, 2009 was slowed down by the shortage of water resources. At present, Dongting Lake region was confronted with the dual task of improving the level and quality of urbanization, and hence, it would be necessary to reform the traditional epitaxial expansion of urbanization and to enhance the water resource support capability.

Large gradient high magnetic fields affect osteoblast ultrastructure and function by disrupting collagen I or fibronectin/αß1 integrin.

The superconducting magnet generates a field and field gradient product that can levitate diamagnetic materials. In this study a specially designed superconducting magnet with a large gradient high magnetic field (LG-HMF), which can provide three apparent gravity levels (µ-g, 1-g, and 2-g), was used to simulate a space-like gravity environment. The effects of LG-HMF on the ultrastructure and function of osteoblast-like cells (MG-63 and MC3T3-E1) and the underlying mechanism were investigated by transmission electromicroscopy (TEM), MTT, and cell western (ICW) assays. Under LG-HMF significant morphologic changes in osteoblast-like cells occurred, including expansion of endoplasmic reticulum and mitochondria, an increased number of lysosomes, distorted microvilli, and aggregates of actin filaments. Compared to controls, cell viability and alkaline phosphatase (ALP) secretion were significantly increased, and collagen I (col I), fibronectin (FN), vinculin, integrin α3, αv, and ß1 expression were changed under LG-HMF conditions. In conclusion, LG-HMF affects osteoblast ultrastructure, cell viability, and ALP secretion, and the changes caused by LG-HMF may be related to disrupting col I or FN/αß1 integrin.

[Effects of Three Gorges Reservoir impoundment on the wetland ecosystem service value of Dongting Lake, South-central China].

Based on the field investigation and measurement, and by using the monetary method, this paper estimated the wetland ecosystem service value of Dongting Lake before and after the impoundment of Three Gorges Reservoir (in 1996 and 2010, respectively). After the impoundment, the total ecosystem service value increased from 156.69x10(8) yuan in 1996 to 177.11x10(8) yuan in 2010. The main services value in 1996 was in the order of flood storage and regulation > water storage and supply > air regulation > scientific research and education, while that in 2010 was leisure tourism > shipping transportation > air regulation > water storage and supply. In the total service value of the wetland ecosystem, the direct value associated with water decreased from 110. 85x10(8) in 1996 to 27.47x10(8) in 2010, with a decrement of 75.2%. Though the proportion of the direct value in the production and supply of material products had somewhat increase, the indirect value in ecological environment regulation and maintenance and in culture and society still maintained at about 80% of the total value. In addition to climate factors, the impoundment of Three Gorges Reservoir and the reduction of water and sediment from Yangtze River to the Lake were the crucial reasons leading to the changes of the wetland ecosystem service value of Dongting Lake.

[Roles of autocrine soluble fibronectin on the maintenance of cell shape of osteosarcoma MG-63 cells].

AIM: To investigate the roles of autocrine soluble FN of MG-63 cells in cell shape maintaining. METHODS: Human osteosarcoma MG-63 cells (1 × 10(4); cells/cm(2);) were routinely cultured in MEM medium+10% fetal bovine serum (FBS) for 24 h and then the medium was replaced by fresh medium(the group without autocrine soluble FN), conditional medium of collected after 24 h of MG-63 cells (the group containing autocrine soluble FN ) and fresh medium with 20 microg/mL FN( the group with plasma FN) after 24 h, and the cell morphology was observed using phase contrast microscope; The concentrations of soluble FN in fresh and conditional medium were detected; Microfilament and insoluble FN changes of MG-63 cells were investigated. RESULTS: The concentration of soluble FN in conditional medium is much higher than that in the fresh medium (P<0.01). Fresh medium will result in the cell shape changing from spindle to round for 0.5 h. The cell began to spread for 1 h, and the cell shape recovered for 2 h; Conditioned medium has no significant effects on cell shape. Addition of FN (20 mg/L) to fresh medium could inhibit the cell shape change induced by fresh medium. Microfilament and insoluble FN were disorganized by fresh medium. CONCLUSION: These results indicated that autocrine soluble FN of osteosarcoma MG-63 cells may be involved in cell shape maintaining.