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Invadopodia are actin-driven membrane protrusions that show oscillatory assembly and disassembly causing matrix degradation to support invasion and dissemination of cancer cells in vitro and in vivo. Profilin1, an actin and phosphoinositide binding protein, is downregulated in several adenocarcinomas and it is been shown that its depletion enhances invasiveness and motility of breast cancer cells by increasing PI(3,4)P2 levels at the leading edge. In this study, we show for the first time that depletion of profilin1 leads to an increase in the number of mature invadopodia and these assemble and disassemble more rapidly than in control cells. Previous work by Sharma et al. (2013a), has shown that the binding of the protein Tks5 with PI(3,4)P2 confers stability to the invadopodium precursor causing it to mature into a degradation-competent structure. We found that loss of profilin1 expression increases the levels of PI(3,4)P2 at the invadopodium and as a result, enhances recruitment of the interacting adaptor Tks5. The increased PI(3,4)P2-Tks5 interaction accelerates the rate of invadopodium anchorage, maturation, and turnover. Our results indicate that profilin1 acts as a molecular regulator of the levels of PI(3,4)P2 and Tks5 recruitment in invadopodia to control the invasion efficiency of invadopodia.

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Spirotetramat, comercialmente conocido como Movento®, es derivado del ácido tetrámico, empleado en el cultivo de la vid y de algunos vegetales para el control de parásitos chupadores. Los estudios toxicológicos in vivo solo publican una descripción general de su metabolismo. El objetivo de este estudio fue conocer los cambios en el comportamiento, en indicadores bioquímicos séricos e histológicos en ratas Wistar macho. Se realizó los siguientes tratamientos: a) intoxicación aguda con Spirotetramat (BY108330, 15.3%) vía oral con 1⁄4 DL50 (625 mg kg-1) y 1⁄2 DL50 (1250 mg kg-1), y b) control. Se obtuvieron muestras de sangre mediante punción cardíaca los días 1, 3 y 7; las muestras se evaluaron por cambios en indicadores bioquímicos (triglicéridos, colesterol, albúmina, proteína total, actividad de transaminasas, urea y creatinina), y cambios histológicos en hígado, riñón y páncreas. Se presentó la muerte en el 35% de los animales tratados. Se observaron signos de toxicidad como: salivación, ataxia, convulsiones, sangrado nasal y diarrea. El peso corporal y el peso relativo del hígado en promedio fueron constantes, sin diferencias entre tratamientos, ni entre días. El perfil lipídico y las transaminasas presentaron una tendencia al incremento en relación al control. En la evaluación histológica los hepatocitos mostraron degeneración balonoide en el 25% (8 de 32) y colestasis en el 72% (23 de 32) de las ratas intoxicadas, sin embargo en bazo y riñón no se observaron cambios visibles en relación al control (AU)

Spirotetramat, derived from tetramic acid, and commercially known as Movento®, is applied in grapevine orchards and other vegetable for the control of sucking pests. Published in vivo toxicological studies report only a general description of its metabolism. The objective of this study was to detect changes in the behavior, in blood biochemical markers, and in histological liver cells on male Wistar rats treated with spirotetramat. The following treatments were applied: a) acute poisoning with spirotetramat (BY108330, 15.3%) oral route with 1⁄4 DL50 (625 mg kg- 1) and 1⁄2 DL50 (1250 mg kg-1), and b) control. Blood samples were obtained by heart punction on days 1, 3 and 7; the samples were evaluated for changes of biochemical indicators (triglycerides, cholesterol, albumin, total protein, transaminase activity, urea and creatinine), and by histological changes in liver, kidney and pancreas. Death occurred in 35% of the treated animals. Some signs of toxicity were observed: nasal running, diarrhea, salivation, ataxia, convulsions, and bleeding. The average body weight and the liver relative weight were stable during the experiment, without differences between treatments, nor between days. The lipid profile and transaminases showed a clear tendency to increase in relation to the control. In the histological evaluation the hepatocytes showed balloonoide degeneration in 25% (8 of 32) and cholestasis in 72% (23 of 32) of the exposed rats; however, there were not visible changes in spleen and kidney in relation to the control (AU)

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In this work we have investigated the influence of NaCl on the adsorption of the antimicrobial cationic peptide bactenecin in the monolayer of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) at the air-water interface, as a function of NaCl concentrations in the subphase. We show that the effect of the salt concentration on DPPC monolayers is a monotonic decrease of the liquid-condensed-liquid-expanded (LC-LE) coexistence region. By contrast, the effect of the bactenecin adsorption at the DPPC monolayer not only removed the LC-LE coexistence region plateau, but also shifted the DPPC isotherms to higher pressures and increased the compressibility of the DPPC/bactenecin monolayers with respect to the pure DPPC monolayer around the LC phase. Analysis of the domain structure, obtained by Brewster angle and atomic force microscopes, indicates that the salt concentration in the subphase builds an electrostatic barrier, increasing the rigidity of DPPC monolayers and limiting the bactenecin adsorption at the LC-LE phase coexistence.

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We report the effect of N-nitrosodiethylamine (NDA) on the interaction between bovine serum albumin (BSA) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine monolayers (DPPC) at the air-water interface. We prepared aqueous solutions of NDA/BSA complexes maintaining a constant concentration of BSA of 1.49 x 10(-9) M and using NDA concentrations to obtain 2000, 4000, 6000, 12,500, and 25,000 NDA/BSA molar ratios. The hysteresis area and the compressional modulus of the compression-expansion cycles performed at different times were dependent on the NDA concentration. The cycles performed demonstrate the stability of the new phase of DPPC/BSA and DPPC/NDA/BSA monolayers. This was achieved probably because the BSA concentration used was lower than the one needed for BSA to inhibit the return of DPPC molecules to the interface. Results of the compressional modulus at the onset of the new phase, obtained around 17 mN/m, 15 min and 1, 3, 5, and 12 h after DPPC deposition, indicated that the 3.0 x 10(-6) M NDA concentration produced a more rigid film, probably due to the higher alpha-helix content of BSA. AFM images were obtained for DPPC/BSA and two DPPC/NDA/BSA complexes. Our images show that 12,500 NDA/BSA molecules were mostly adsorbed in the liquid condensed phase. However, BSA molecules were distributed more homogeneously.

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Interfacial properties of N-nitrosodiethylamine/bovine serum albumin (NDA/BSA) complexes were investigated at the air-water interface. The interfacial behavior at the chloroform-water interface of the interaction product of phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), dissolved in the chloroform phase, and NDA/BSA complex, in the aqueous phase, were also analyzed by using a drop tensiometer. The secondary structure changes of BSA with different NDA concentrations were monitored by circular dichroism spectroscopy at different pH and the NDA/BSA interaction was probed by fluorescence spectroscopy. Different NDA/BSA mixtures were prepared from 0, 7.5 x 10(-5), 2.2 x 10(-4), 3.7 x 10(-4), 5 x 10(-4), 1.6 x 10(-3), and 3.1 x 10(-3) M NDA solutions in order to afford 0, 300/1, 900/1, 1 500/1, 2 000/1, 6 000/1, and 12 500/1 NDA/BSA molar ratios, respectively, in the aqueous solutions. Increments of BSA alpha-helix contents were obtained up to the 2 000/1 NDA/BSA molar ratio, but at ratios beyond this value, the alpha-helix content practically disappeared. These BSA structure changes produced an increment of the surface pressure at the air-water interface, as the alpha-helix content increased with the concentration of NDA. On the contrary, when alpha-helix content decreased, the surface pressure also appeared lower than the one obtained with pure BSA solutions. The interaction of DPPC with NDA/BSA molecules at the chloroform-water interface produced also a small, but measurable, pressure increment with the addition of NDA molecules. Dynamic light scattering measurements of the molecular sizes of NDA/BSA complex at pH 4.6, 7.1, and 8.4 indicated that the size of extended BSA molecules at pH 4.6 increased in a greater proportion with the increment in NDA concentration than at the other studied pH values. Diffusion coefficients calculated from dynamic surface tension values, using a short-term solution of the general adsorption model of Ward and Tordai, also showed differences with pH and the NDA concentration. Both, the storage and loss dilatational elastic modulus were obtained at the air-water and at the chloroform-water interfaces. The interaction of NDA/BSA with DPPC at the chloroform-water produced a less rigid monolayer than the one obtained with pure DPPC (1 x 10(-5) M), indicating a significant penetration of NDA/BSA molecules at the interface. At short times and pH 4.6, the values of the storage elastic modulus were larger and more sensible to the NDA addition than the ones at pH 7.1 and 8.4, probably due to a gel-like network formation at the air-water interface.

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