Bone marrow mesenchymal/fibroblastic stromal cells induce a distinctive EMT-like phenotype in AML cells

The development of epithelial-to-mesenchymal transition (EMT) like features is emerging as a critical factor involved in the pathogenesis of acute myeloid leukaemia (AML). However, the extracellular signals and the signalling pathways in AML that may regulate EMT remain largely unstudied. We found that the bone marrow (BM) mesenchymal/fibroblastic cell line HS5 induces an EMT-like migratory phenotype in AML cells. AML cells underwent a strong increase of vimentin (VIM) levels that was not mirrored to the same extent by changes of expression of the other EMT core proteins SNAI1 and SNAI2. We validated these particular pattern of co-expression of core-EMT markers in AML cells by performing an in silico analysis using datasets of human tumours. Our data showed that in AML the expression levels of VIM does not completely correlate with the co-expression of core EMT markers observed in epithelial tumours. We also found that vs epithelial tumours, AML cells display a distinct patterns of co-expression of VIM and the actin binding and adhesion regulatory proteins that regulate F-actin dynamics and integrin-mediated adhesions involved in the invasive migration in cells undergoing EMT. We conclude that the BM stroma induces an EMT related pattern of migration in AML cells in a process involving a distinctive regulation of EMT markers and of regulators of cell adhesion and actin dynamics that should be further investigated. Understanding the tumour specific signalling pathways associated with the EMT process may contribute to the development of new tailored therapies for AML as well as in different types of cancers.

Plants' genetic variation approach applied to zinc contamination: secondary metabolites and enzymes of the antioxidant system in Pfaffia glomerata accessions

Zinc (Zn) is a micronutrient, but its excessive concentration can impair plant growth and development. Fertilizers, liming materials, pesticides and fungicides containing Zn have contributed to increase its concentration in agricultural soils. The aim of the present study is to evaluate the effect of Zn excess on the non-enzymatic (anthocyanin and β-ecdysone) and enzymatic (superoxide dismutase-SOD and guaiacol peroxidase-GPX) antioxidant system of two P. glomerata accessions (JB and GD) grown in hydroponic system and soil, under short- and long-term exposure times. Three Zn levels (2, 100 and 200 μM) and two short-term exposure times (7 and 14 d) were tested in the hydroponic experiment. Three Zn levels (2, 100 and 200 mg kg^-1) and two long-term exposure times (34 and 74 d) were tested in the soil experiment. The effects of Zn excess on P. glomerata accessions depended on the growth system and exposure time. Zinc excess in both tested growth systems resulted in significant change in the tissue oxidative process (MDA concentration) in both accessions, as well as broadened the antioxidant system response, which was based on antioxidant enzymes (SOD and GPX) and secondary metabolites (anthocyanins and β-ecdysone). The highest anthocyanin concentration was observed in accession JB, which was grown in hydroponics, but tissue anthocyanin concentration increased in both accessions, regardless of growth medium and exposure time. The β-ecdysone concentration in the roots increased in both accessions, but accession GD was more responsive to Zn excess. There was significant physiological variation in P.glomerata accessions in response to Zn excess.

Improved Yield and Photosynthate Partitioning in AVP1 Expressing Wheat (Triticum aestivum) Plants

A fundamental factor to improve crop productivity involves the optimization of reduced carbon translocation from source to sink tissues. Here, we present data consistent with the positive effect that the expression of the Arabidopsis thaliana H+-PPase (AVP1) has on reduced carbon partitioning and yield increases in wheat. Immunohistochemical localization of H+-PPases (TaVP) in spring wheat Bobwhite L. revealed the presence of this conserved enzyme in wheat vasculature and sink tissues. Of note, immunogold imaging showed a plasma membrane localization of TaVP in sieve element- companion cell complexes of Bobwhite source leaves. These data together with the distribution patterns of a fluorescent tracer and [U14C]-sucrose are consistent with an apoplasmic phloem-loading model in wheat. Interestingly, 14C-labeling experiments provided evidence for enhanced carbon partitioning between shoots and roots, and between flag leaves and milk stage kernels in AVP1 expressing Bobwhite lines. In keeping, there is a significant yield improvement triggered by the expression of AVP1 in these lines. Green house and field grown transgenic wheat expressing AVP1 also produced higher grain yield and number of seeds per plant, and exhibited an increase in root biomass when compared to null segregants. Another agriculturally desirable phenotype showed by AVP1 Bobwhite plants is a robust establishment of seedlings.

Sperm characteristics of wild and captive lebranche mullet Mugil liza (Valenciennes, 1836), subjected to sperm activation in different pH and salinity conditions

In this article we describe basic aspects of the sperm biology of lebranche mullet (Mugil liza) in the wild and in captivity, in particular assessing the effects of salinity (0, 10, 20, 30, 35, 40, 50 and 60 g L^-1) and pH (6, 7, 8, 9 and 10) on sperm motility. Our results indicate that the highest percentage of motility was recorded with salinity 34.6 g L^-1 (95 ± 10%) and the longest motility time was obtained with a salinity of 34.8 g L^-1 (189 ± 15 s). Variations in the salinity between 30 and 35 g L^-1 did not produce any significant alterations in sperm motility; however salinities of 20 and 50 g L^-1 produced a significant loss of sperm motility. The highest percentage of motility was obtained at pH 8.5 (93 ± 12%), and the longest motility period at pH 8.7 (218 ± 13 s), while pH lower than or equal to 7 and equal to 10 both produced a significant loss in sperm motility. A positive correlation was found between pH/salinity and the motility percentage (R² = 0.94 and R² = 0.97) and motility time (R² = 0.86 and R² = 0.98). In seminal and morphometric parameters, statistically significant differences were observed in semen volume, sperm density, plasma membrane integrity and sperm morphometry between the groups studied, showing that the characteristics of the fish have a direct influence on sperm quality. The information generated in this research will be useful for developing biotechnology tools for the effective management of Mugil liza gametes.

Cryopreservation of Atlantic salmon Salmo salar sperm: effects on sperm physiology

The objective of this study was to determine the effect of freezing on the function in Atlantic salmon Salmo salar spermatozoa. The semen was frozen in Cortland's medium + 1.3M dimethyl sulphoxide + 0.3M glucose + 2% bovine serum albumin (final concentration) in a ratio of 1:3 (semen:cryoprotectant) as the treatment (T) and fresh semen as the control (F). Straws of 0·5 ml of sperm suspension were frozen in 4 cm of N2 L. They were thawed in a thermoregulated bath (40° C). After thawing, the percentage of spermatozoa with fragmented DNA [transferase dUTP (deoxyuridine triphosphate) nick-end labelling (TUNEL)], plasma membrane integrity (SYBR-14/PI) and mitochondrial membrane potential (ΔΨMMit, JC-1) were evaluated by flow cytometry and motility was evaluated by optical microscope under stroboscopic light. The fertilization rates of the control and treatment semen were tested at a sperm density of 1·5 × 10(7) spermatozoa oocyte(-1) , by observation of the first cleavages after 16 h incubation at 10° C. In the cryopreserved semen (T), the mean ± s.d. DNA fragmentation was 4·8 ± 2·5%; plasma membrane integrity 75·2 ± 6·3%; mitochondrial membrane potential 51·7 ± 3·6%; motility 58·5 ± 5·3%; curved line velocity (VCL ) 61·2 ± 17·4 µm s(-1) ; average-path velocity (VAP ) 50·1 ± 17·3 µm s(-1) ; straight-line velocity (VSL ) 59·1 ± 18·4 µm s(-1) ; fertilization rate 81·6 ± 1·9%. There were significant differences in the plasma membrane integrity, mitochondrial membrane potential, motility, fertilization rate, VCL , VAP and VSL compared with the controls (P < 0·05). Also the mitochondrial membrane potential correlated with motility, fertilization rate, VCL and VSL (r = 0·75; r = 0·59; r = 0·77 and r = 0·79, respectively; P < 0·05); and the fertilization rate correlated with VCL and VSL (r = 0·59 and r = 0·55, respectively).

Rethinking Rice Preparation for Highly Efficient Removal of Inorganic Arsenic Using Percolating Cooking Water

A novel way of cooking rice to maximize the removal of the carcinogen inorganic arsenic (Asi) is presented here. In conventional rice cooking water and grain are in continuous contact, and it is known that the larger the water:rice cooking ratio, the more Asi removed by cooking, suggesting that the Asi in the grain is mobile in water. Experiments were designed where rice is cooked in a continual stream of percolating near boiling water, either low in Asi, or Asi free. This has the advantage of not only exposing grain to large volumes of cooking water, but also physically removes any Asi leached from the grain into the water receiving vessel. The relationship between cooking water volume and Asi removal in conventional rice cooking was demonstrated for the rice types under study. At a water-to-rice cooking ratio of 12:1, 57±5% of Asi could be removed, average of 6 wholegrain and 6 polished rice samples. Two types of percolating technology were tested, one where the cooking water was recycled through condensing boiling water steam and passing the freshly distilled hot water through the grain in a laboratory setting, and one where tap water was used to cook the rice held in an off-the-shelf coffee percolator in a domestic setting. Both approaches proved highly effective in removing Asi from the cooking rice, with up to 85% of Asi removed from individual rice types. For the recycled water experiment 59±8% and 69±10% of Asi was removed, on average, compared to uncooked rice for polished (n=27) and wholegrain (n=13) rice, respectively. For coffee percolation there was no difference between wholegrain and polished rice, and the effectiveness of Asi removal was 49±7% across 6 wholegrain and 6 polished rice samples. The manuscript explores the potential applications and further optimization of this percolating cooking water, high Asi removal, discovery.

Effect of seminal plasma on Atlantic salmon (Salmo salar) sperm vitrification

This study was designed to test a vitrification method in Atlantic salmon spermatozoa and determine the capacity of seminal plasma (SP) to protect these cells from cryoinjuries. The vitrification medium consisted of a standard buffer for fish spermatozoa (Cortland medium) + 10% DMSO + 2% BSA + 0.13-M sucrose + SP at concentrations of 30% (G30), 40% (G40), or 50% (G50). Fresh sperm was used as a control. To freeze the samples, 30-μL suspensions of spermatozoa from each group were dropped directly into liquid nitrogen. The resulting spheres were placed in cryotubes for storage in liquid nitrogen. The cryotubes with the vitrified spermatozoa were thawed by placing them in a water bath at 37 °C for 45 seconds. After thawing, the following sperm quality parameters were determined by flow cytometry: DNA fragmentation (terminal deoxynucleotidyl transferase dUTP nick end labeling), plasma membrane integrity (SYBR-14/PI, staining technique), and mitochondrial membrane potential (JC-1 staining). An optical microscope was used to assess subjectively sperm motility, whereas fertility was determined by the presence of neurulation using five replicates per treatment in a sample of 30 eggs. Spermatozoa quality variables were preserved best when the highest concentration of SP (50%) was used (DNA fragmentation, 9.2%; plasma membrane integrity, 98.6%; mitochondrial membrane integrity, 47.2%; motility, 44.1%; and fertility, 46.2%).

Effect of Hg, As and Pb on biomass production, photosynthetic rate, nutrients uptake and phytochelatin induction in Pfaffia glomerata

Plantlets of Pfaffia glomerata (Spreng.) were exposed for 28 days to three different metal/metalloid (Hg, Pb and As) with different levels (Hg 1; As 25, 50, 100 and Pb 100 and 400 μM) to analyze the possible phytochelatin initiation and affects on growth and photosynthetic pigments vis-à-vis metal accumulation potential of plants. The plantlets showed significant Hg, As and Pb accumulation in roots (150, 1267.67 and 2129 μg g(-1) DW respectively); however, a low root to shoot metal translocation was observed. It was interesting to note that all tested macronutrient (Mg, K, Ca) was higher in shoots and just opposite in case of micronutrients (Cu, Fe, Zn), was recorded highest in roots. The growth of plantlets (analyzed in terms of length and dry weight) was negatively affected by various metal treatments. In addition, the level of photosynthetic pigments alters significantly in response to all metal/metalloid treatment. In response to all tested metal/metalloids in plants only As induced phytochelatins (PC2, PC3 and PC4) in roots, and in shoots, GSH was observed in all tested metal/metalloids. In conclusion, P. glomerata plantlets could not cooperatively induce phytochelatins under any of Hg and Pb levels.

Bacterial consortium for copper extraction from sulphide ore consisting mainly of chalcopyrite

The mining industry is looking forward for bacterial consortia for economic extraction of copper from low-grade ores. The main objective was to determine an optimal bacterial consortium from several bacterial strains to obtain copper from the leach of chalcopyrite. The major native bacterial species involved in the bioleaching of sulphide ore (Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans and Leptospirillum ferriphilum) were isolated and the assays were performed with individual bacteria and in combination with At. thiooxidans. In conclusion, it was found that the consortium integrated by At. ferrooxidans and At. thiooxidans removed 70% of copper in 35 days from the selected ore, showing significant differences with the other consortia, which removed only 35% of copper in 35 days. To validate the assays was done an escalation in columns, where the bacterial consortium achieved a higher percentage of copper extraction regarding to control.

Effects of lead on the growth, lead accumulation and physiological responses of Pluchea sagittalis

This work aimed to study the process of stress adaptation in root and leaves of different developmental stages (apex, middle and basal regions) of Pluchea sagittalis (Lam.) Cabrera plants grown under exposure to five Pb levels (0, 200, 400, 600 and 1000 μM) for 30 days. Pb concentration and content in roots, stems, and leaves of different developmental stages increased with external Pb level. Consumption of nutrient solution, transpiration ratio, leaf fresh weight, leaf area, and shoot length decreased upon addition of Pb treatments. However, dry weight of shoot parts and roots did not decrease upon addition of Pb treatments. Based on index of tolerance, the roots were much more tolerant to Pb than shoots. δ-aminolevulinic acid dehydratase activity was decreased by Pb treatments, whereas carotenoid and chlorophyll concentrations were not affected. Lipid peroxidation and hydrogen peroxide concentration both in roots and leaves increased with increasing Pb levels. Pb treatments increased ascorbate peroxidase activity in all plant parts, while superoxide dismutase activity increased in leaves and did not change in roots. Catalase activity in leaves from the apex shoot was not affected by Pb, but in other plant parts it was increased. Pb toxicity caused increase in non-protein thiol groups concentration in shoot parts, whereas no significant difference was observed in roots. Both root and shoot ascorbic acid concentration increased with increasing Pb level. Therefore, it seems that Pb stress triggered an efficient defense mechanism against oxidative stress in P. sagittalis but its magnitude was depending on the plant organ and of their physiological status. In addition, these results suggest that P. sagittalis is Pb-tolerant. In conclusion, P. sagittalis is able to accumulate on average 6730 and 550 μg Pb g(-1) dry weight, respectively, in the roots and shoot, a physiological trait which may be exploited for the phytoremediation of contaminated soils and waters.

Aluminum-induced oxidative stress in cucumber

Aluminum (Al) is one of the most abundant elements of the planet and exposure to this metal can cause oxidative stress and lead to various signs of toxicity in plants. Plants are essential organisms for the environment as well as food for humans and animals. The toxic effect of aluminum is the major cause of decreased crop productivity. Thus, the objective of the present study was to analyze the effects of aluminum on the activity of antioxidant enzymes such as catalase (CAT - E.C. 1.11.1.6), superoxide dismutase (SOD - E.C.1.15.1.1) and ascorbate peroxidase (APX - E.C. 1.11.1.11), and on lipid peroxidation, electrolyte leakage percentage (ELP) and chlorophyll and protein oxidation levels in Cucumis sativus L. (cv. Aodai). Seedlings were grown at different concentrations of aluminum ranging from 1 to 2000 microM for 10 days. The increase in ELP and H(2)O(2) production observed in the seedlings may be related to the decreased efficiency of the antioxidant system at higher aluminum concentrations. The antioxidant system was unable to overcome toxicity resulting in negative effects such as lipid peroxidation, protein oxidation and a decrease in the growth of Cucumis seedlings. Aluminum toxicity triggered alterations in the antioxidant and physiological status of growing cucumber seedlings.

Effects of chronic hypobaric hypoxia on testis histology and round spermatid oxidative metabolism

In order to evaluate the effects of the exposition to continuous chronic hypobaric hypoxia (CCHH) and intermittent chronic hypobaric hypoxia (ICHH) on testis histology and on oxidative metabolism of spermatogenic cells (SC), male rats were exposed to a 4600-m simulated altitude (PO2: 89.6 mmHg). After 60 days, ICHH and CCHH groups presented a significant decrease in testicular mass, an increase in interstitial space, a decrease in height of the seminiferous epithelium, depletion of cellular elements, vacuolization in epithelial cells and folding of the basal membrane. Round spermatids from animals exposed to CCHH presented a significant decrease in energy-dependent cell shape changes. Round spermatid mitochondria of CCHH rats seem to be limited in their ability to handle reducing equivalents. These mitochondria also appear to be uncoupled under basal conditions. Round spermatids from CCHH rats evidence large oxygen consumption (QO2) insensitive to inhibition by cyanide, a process that could be partly related to lipoperoxidation. Thus, exposure of male rats to CCHH and ICHH induced evident changes in testicular morphology and loss of spermatogenic cells, in all stages of the spermatogenic cycle. This post-meiotic spermatogenic cell loss in the testis correlated well with metabolic changes in round spermatids that evidenced a strong metabolic stress in these cells.