Carbon nanodot aqueous binding phase-based diffusive gradients in thin films device for measurement of dissolved copper and lead species in the aquatic environment.

A reliable method for the determination of dissolved Cu2+ and Pb2+ species in water via a diffusive gradient in thin films (DGT) device using water-soluble carbon nanodots (CD) as the binding agent was developed (CD-DGT). The uptake of dissolved Cu2+ and Pb2+ species by CD-DGT increased linearly with a deployment time of over 120 h, while the uptake of Ca2+, Mg2+, Cd2+, Zn2+, Ni2+, and Co2+ by CD-DGT has no significant linear accumulation during the same deployment time. The concentrations of the dissolved Cu2+ and Pb2+ species measured using CD-DGT are in good agreement with the element concentrations spiked directly in a tested synthesis solution. The performance of CD-DGT for the determination of dissolved Cu2+ and Pb2+ species is found to be independent of ionic strength in the range of 0.001-0.05 mol L-1 and in the pH range from 5 to 8. The presence of fulvic acid and tannic acid has no significant influence on the uptake of dissolved Cu2+ and Pb2+ species by CD-DGT under the tested conditions. In different water samples, good agreement was observed between the dissolved Cu2+ and Pb2+ concentrations measured by CD-DGT, and diffusive equilibration in the thin film devices was found. Based on the results obtained, CD-DGT enables the selective and quantitative determination of dissolved Cu2+ and Pb2+ species in water.

Essential role of miR-200c in regulating self-renewal of breast cancer stem cells and their counterparts of mammary epithelium.

BACKGROUND: Breast cancer stem cells (BCSCs) have been reported as the origin of breast cancer and the radical cause of drug resistance, relapse and metastasis in breast cancer. BCSCs could be derived from mutated mammary epithelial stem cells (MaSCs). Therefore, comparing the molecular differences between BCSCs and MaSCs may clarify the mechanism underlying breast carcinogenesis and the targets for gene therapy. Specifically, the distinct miRNome data of BCSCs and MaSCs need to be analyzed to find out the key miRNAs and reveal their roles in regulating the stemness of BCSCs. METHODS: MUC1(-)ESA(+) cells were isolated from normal mammary epithelial cell line MCF-10A by fluorescence-activated cell sorting (FACS) and tested for stemness by clonogenic assay and multi-potential differentiation experiments. The miRNA profiles of MaSCs, BCSCs and breast cancer MCF-7 cells were compared to obtain the candidate miRNAs that may regulate breast tumorigenesis. An miRNA consecutively upregulated from MaSCs to BCSCs to MCF-7 cells, miR-200c, was chosen to determine its role in regulating the stemness of BCSCs and MaSCs in vitro and in vivo. Based on bioinformatics, the targets of miR-200c were validated by dual-luciferase report system, western blot and rescue experiments. RESULTS: In a 2-D clonogenic assay, MUC1(-)ESA(+) cells gave rise to multiple morphological colonies, including luminal colonies, myoepithelial colonies and mixed colonies. The clonogenic potential of MUC1(-)ESA(+) (61.5 ± 3.87 %) was significantly higher than that of non-stem MCF-10A cells (53.5 ± 3.42 %) (P < 0.05). In a 3-D matrigel culture, MUC1(-)ESA(+) cells grew into mammospheres with duct-like structures. A total of 12 miRNAs of interest were identified, 8 of which were upregulated and 4 downregulated in BCSCs compared with MaSCs. In gain- and lost-of-function assays, miR-200c was sufficient to inhibit the self-renewal of BCSCs and MaSCs in vitro and the growth of BCSCs in vivo. Furthermore, miR-200c negatively regulated programmed cell death 10 (PDCD10) in BCSCs and MaSCs. PDCD10 could rescue the tumorigenesis inhibited by miR-200c in BCSCs. DISCUSSION: Accumulating evidence shows that there is a milignant transformation from MaSCs into BCSCs. The underlying mechanism remains unclear. In present study, miRNA profiles between MaSCs and BCSCs were obtained. Then miRNA-200c, downregulated in both MaSCs and BCSCs, were verified as anti-oncogene, and played essential role in regulating self-renewal of both kinds of stem-like cells. These findings reveal a novel insights of breast tumorigenesis. CONCLUSIONS: PDCD10 is a target gene of miR-200c and also a possible mechanism by which miR-200c plays a role in regulating the stemness of BCSCs and MaSCs.

[Intensive insulin treatment protected the cardiac myocytes against apoptosis in severely scalded rats].

OBJECTIVE: To investigate the effect of intensive insulin treatment, in the protection of myocardiocytes against apoptosis in severely scalded rats and its underlying mechanism. METHODS: Eighteen Sprague-Dawley (SD) rats were randomly divided into three groups (6/each) to receive: sham surgery, burn damage (on the back of the animals, degreeIII, to 30% of total body surface area), and burn damage+intensive insulin treatment. Tissue samples were collected from the left ventricle 6 hours after infliction of the burn damage for the examination of myocardial cell apoptosis [by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining] and the expression of apoptosis-related molecules caspase-3, Bax, and Bcl-2 (by immuno-histochemistry and Western blotting). RESULTS: In comparison with the animals in sham treated group, the myocardiocyte apoptosis rate in animals in burn damage only group increased significantly [(13.1 ± 3.4)% vs. (0.6 ± 0.4)%, P < 0.01]. The expression of caspase-3 and Bax both significantly increased while the level of Bcl-2 expression significantly decreased (immuno-histochemistry caspase-3: 13.72 ± 4.13 vs. 1.36 ± 0.95, Bax: 29.64 ± 5.42 vs. 2.24 ± 1.04, Bcl-2: 3.39 ± 1.52 vs. 8.01 ± 2.56; Western blotting caspase-3: 5.72 ± 2.13 vs. 1, Bax: 4.64 ± 1.42 vs. 1, Bcl-2: 0.69 ± 0.42 vs. 1, all P < 0.01). The animals received intensive insulin treatment showed significantly less myocardiocyte apoptosis [(6.7 ± 1.8)% vs. (13.1 ± 3.4)%, P < 0.01], significantly lower expression in caspase-3, Bax, and significantly higher level of Bcl-2 expression as compared to the animals in burn damage only group (immuno-histochemistry caspase-3: 8.88 ± 3.36 vs. 13.72 ± 4.13, Bax: 14.43 ± 3.69 vs. 29.64 ± 5.42, Bcl-2: 8.61 ± 3.72 vs. 3.39 ± 1.52; Western blotting caspase-3: 2.18 ± 0.86 vs. 5.72 ± 2.13, Bax: 2.87 ± 1.35 vs. 4.64 ± 1.42, Bcl-2: 3.57 ± 1.70 vs. 0.69 ± 0.42, P < 0.05 or P < 0.01). CONCLUSION: Intensive insulin therapy may protect myocardiocytes against apoptosis in severely burned animals through the regulation of the expression of apoptosis-related molecules caspase-3, Bax and Bcl-2.