A secretome profile indicative of oleate-induced proliferation of HepG2 hepatocellular carcinoma cells

Increased fatty acid (FA) is often observed in highly proliferative tumors. FAs have been shown to modulate the secretion of proteins from tumor cells, contributing to tumor survival. However, the secreted factors affected by FA have not been systematically explored. Here, we found that treatment of oleate, a monounsaturated omega-9 FA, promoted the proliferation of HepG2 cells. To examine the secreted factors associated with oleate-induced cell proliferation, we performed a comprehensive secretome profiling of oleate-treated and untreated HepG2 cells. A comparison of the secretomes identified 349 differentially secreted proteins (DSPs; 145 upregulated and 192 downregulated) in oleate-treated samples, compared to untreated samples. The functional enrichment and network analyses of the DSPs revealed that the 145 upregulated secreted proteins by oleate treatment were mainly associated with cell proliferation-related processes, such as lipid metabolism, inflammatory response, and ER stress. Based on the network models of the DSPs, we selected six DSPs (MIF, THBS1, PDIA3, APOA1, FASN, and EEF2) that can represent such processes related to cell proliferation. Thus, our results provided a secretome profile indicative of an oleate-induced proliferation of HepG2 cell

Electrodialytic phosphorus recovery from sewage sludge ash under kinetic control

financial support provided by CENSE-Center for Environmental and Sustainability Research which is financed by national funds from FCT/MEC (UID/AMB/i04085/2013). Villen-Guzman also acknowledges the "Contrato Puente (CI-17-010)" obtained from University of Malaga.A mathematical model for simulating the electrodialytic phosphorus recovery from sewage sludge ash containing heavy metal (Al, Fe, Zn, Cu, Cr, Cd and Ni) is presented. The complex chemical system proposed consists of 46 species including aqueous and solid species. The system setup is modelled as a four compartments: solid, liquid, anode and cathode. In addition to typical phenomena; such as: electromigration of ionic, simple and complex species from the liquid phase to anode and cathode through ionic membranes and diffusion transport; kinetically controlled processes due to non-equilibrium between solid phase and bulk liquid have been incorporated. The simulation results clarify the behavior of heavy metal when an electric current is applied which is essential for the scaling-up of the ED technology.authorsversionpublishe

Effects of the buffering capacity of the soil on the mobilization of heavy metals. Equilibrium and kinetics.

Understanding the possible pH-buffering processes is of maximum importance for risk assessment and remediation feasibility studies of heavy-metal contaminated soils. This paper presents the results about the effect of the buffering capacity of a polluted soil, rich in carbonates, on the pH and on the leaching evolution of its main contaminant (lead) when a weak acid (acetic acid) or a strong one (nitric acid) are slowly added. In both cases, the behavior of lead dissolution could be predicted using available (scientifically verified freeware) models assuming equilibrium between the solid and the aqueous phase. However, the experimental results indicate that the dissolution of calcium and magnesium carbonates is kinetically controlled. These kinetic limitations affect the overall behavior, and should be considered to understand also the response of the metals under local equilibrium. The well-known BCR sequential extraction procedure was used before- and after-treatment, to fractionate the lead concentration in the soil according to its mobility. The BCR results were also in agreement with the predictions of the equilibrium model. This agreement allows new insights about the information that could be derived from the BCR fractionation analysis

Scaling-up the acid-enhanced electrokinetic remediation of a real contaminated soil

Although there is a lot of experimental work published about the use of Electrokinetic Remediation for the removal of toxic metals from soils, very few have reported results for different scales. Scaling- up is a difficult task, since the behavior of each metal is different and is also site-specific. In this paper we present a convenient parameter for the comparison of the energy requirements at different scales. This parameter consists on the definition of a specific-energy for each metal, based on the amount mobilized and the maximum removal expected as determined from the BCR fractionation analysis. The tests, which were carried out with soil columns holding soil samples of 16 g and with soil samples of 2000 g, are giving similar values of this parameter. Our results indicate that this specific-energy depends on the target metal to be recovered, but for each metal is quite similar for the experimental conditions of the two scales essayed. These conditions included that the initial electrical resistivity times the column length were equal for the two scales. A simple mathematical model predicts these results, and that for equal resistivity the specific energy requirement will be proportional to the distance between electrodes. (C) 2015 Elsevier Ltd. All rights reserved

The use of ethylenediaminetetraacetic acid as enhancing agent for the remediation of a lead polluted soil

Result: for Pb extraction experiments from a contaminated soil performed with citric acid and ethylenediaminetetraacetic acid disodium salt (Na(2)EDTA) indicate that Na(2)EDTA is much more efficient. The Pb removal after 5 successive extractions using 24 mL of 0.1 M Na(2)EDTA solutions and 8 g of soil is close to 100%. Other non-toxic metals such as Ca and Mg, that are present in important concentrations in this soil, are also solubilized, but important differences in the behavior of each metal are observed. A local equilibrium model is used for the interpretation of the results of these batch experiments; the experimental and the model results are in a fairly good agreement. From these results it is concluded that Na(2)EDTA presents almost ideal characteristics for its use as enhancing agent for an electrokinetic remediation of the soil. Therefore, experiments were performed, in which the pH value is controlled at both electrode-compartments using Na(2)EDTA at the cathode and NaOH at the anode, aiming to the recovery of PbEDTA(2-) at the anode. Nevertheless, no significant amounts of lead are recovered. The possible negative effects of the electric current over the performance of Na(2)EDTA are studied using a two-compartment cell for electrodialytic remediation with an important electrical current and comparing the results with those obtained under identical conditions without current. It is concluded that the electric current produce no negative effects. Therefore, the cancelling effects of the electromigration and the electroosmotic movement are considered as the most probable explanation for the experimental results. (C) 2015 Elsevier Ltd. All rights reserved

Feasibility Study of the Electrokinetic Remediation of a Mercury-Polluted Soil

This chapter is focused on the study of electroremediation of heavy metals from a real soil. Specifically, the case of the study was a soil from Almaden mining district, with a very high mercury concentration. The risk assessment of heavy metals depends on the mobility and bioavailability and not only on the total concentration. Therefore, this study evaluates the distribution of mercury into different fractions before and after the electrokinetic treatment. The electrokinetic experiments were performed in two operating scales that differ in more than two orders of magnitude. The results for both scales are consistent with the predictions of simple models, so it can be assumed that they are useful for the evaluation of a full-scale implementation. Two enhancing agents were studied in the application of electrokinetic process according to the mercury distribution in BCR fractions (Community Bureau of Reference). First, iodide was applied as complexing agent, and it was found that after treatment the most mobile fraction of mercury increased. Thus, to remove this mobile mercury fraction, electroremediation experiments were done with nitric acid as enhancing agent