Effect of Mercury on Membrane Proteins, Anionic Transport and Cell Morphology in Human Erythrocytes.

Mercury (Hg) is a heavy metal widespread in all environmental compartments as one of the most hazardous pollutants. Human exposure to this natural element is detrimental for several cellular types including erythrocytes (RBC) that accumulate Hg mainly bound to the SH groups of different cellular components, including protein cysteine residues. The cellular membrane represents a major target of Hg-induced damage in RBC with loss of physiological phospholipid asymmetry, due to phosphatidylserine (PS) exposure to the external membrane leaflet. To investigate Hg-induced cytotoxicity at the molecular level, the possible interaction of this heavy metal with RBC membrane proteins was investigated. Furthermore, Hg-induced alterations in band 3 protein (B3p) transport function, PS-exposing macrovesicle (MVs) formation and morphological changes were assessed. For this aim, human RBC were treated in vitro with different HgCl <sub>2</sub> concentrations (range 10-40 µM) and the electrophoretic profile of membrane proteins as well as the expression levels of Ankyrin and Flottilin-2 evaluated by SDS-PAGE and Western blot, respectively. The effect of alterations in these proteins on RBC morphology was evaluated by digital holographic microscopy and anionic transport efficiency of B3p was evaluated as sulphate uptake. Finally, PS- bearing MVs were quantified by annexin-V binding using FACS analysis. Findings presented in this paper indicate that RBC exposure to HgCl <sub>2</sub> induces modifications in the electrophoretic profile of membrane protein fraction. Furthermore, our study reveals the Hg induced alterations of specific membrane proteins, such as Ankyrin, a protein essential for membrane-cytoskeleton linkage and Flotillin-2, a major integral protein of RBC lipid rafts, likely responsible for decreased membrane stability and increased fragmentations. Accordingly, under the same experimental conditions, RBC morphological changes and PS-bearing MVs release are observed. Finally, RBC treatment significantly affects the B3p-mediated anionic transport, that we report reduced upon HgCl <sub>2</sub> treatment in a dose dependent manner. Altogether, the findings reported in this paper confirm that RBC are particularly vulnerable to Hg toxic effect and provide new insight in the Hg-induced protein modification in human RBC affecting the complex biological system of cellular membrane. In particular, Hg could induce dismantle of vertical cohesion between the plasma membrane and cytoskeleton as well as destabilization of lateral linkages of functional domains. Consequently, decreased membrane deformability could impair RBC capacity to deal with the shear forces in the circulation increasing membrane fragmentations. Furthermore, findings described in this paper have also significant implication in RBC physiology, particularly related to gas exchanges

Aplicación de índices de calidad de agua en un arroyo pampeano utilizando macroinvertebrados bentónicos como bioindicadores (Gualeguaychú, Entre Ríos, Argentina)

Water quality can be evaluated through a set of physical, chemical and environmental variables that characterize the water body under study. These variables, along with the climate impact,hydrological regime and land use, determine the diversity of organisms. Santa Barbara Stream is a loworder stream and is located in the Gualeguaychú Departament, Entre Ríos, in the Pampean Ecorregion. In order to study the water quality, benthonic macroinvertebrates and physical chemical variables were studied, between March and October 2012. Sixteen orders, 1 suborder and 27 invertebrates families were found. The most abundant families were Cochliopidae, Paleomonidae, Caenidae, and Sphaeriidae. BMWP, IBF, IMRP and IBPamp biotic indices and diversity index of Shannon-Weaver were applied. These showed different results suggesting the need for further studies of water bodies of the Pampas Ecorregion and adjustment of indices for the region. The combined application of different rates indicates that the stream shows signs of seasonal organic pollution associated with land use in the basin.Facultad de Ciencias Naturales y Muse

Aplicación de índices de calidad de agua en un arroyo pampeano utilizando macroinvertebrados bentónicos como bioindicadores (Gualeguaychú, Entre Ríos, Argentina)

Water quality can be evaluated through a set of physical, chemical and environmental variables that characterize the water body under study. These variables, along with the climate impact,hydrological regime and land use, determine the diversity of organisms. Santa Barbara Stream is a loworder stream and is located in the Gualeguaychú Departament, Entre Ríos, in the Pampean Ecorregion. In order to study the water quality, benthonic macroinvertebrates and physical chemical variables were studied, between March and October 2012. Sixteen orders, 1 suborder and 27 invertebrates families were found. The most abundant families were Cochliopidae, Paleomonidae, Caenidae, and Sphaeriidae. BMWP, IBF, IMRP and IBPamp biotic indices and diversity index of Shannon-Weaver were applied. These showed different results suggesting the need for further studies of water bodies of the Pampas Ecorregion and adjustment of indices for the region. The combined application of different rates indicates that the stream shows signs of seasonal organic pollution associated with land use in the basin.Facultad de Ciencias Naturales y Muse

Aplicación de índices de calidad de agua en un arroyo pampeano utilizando macroinvertebrados bentónicos como bioindicadores (Gualeguaychú, Entre Ríos, Argentina)

Water quality can be evaluated through a set of physical, chemical and environmental variables that characterize the water body under study. These variables, along with the climate impact,hydrological regime and land use, determine the diversity of organisms. Santa Barbara Stream is a loworder stream and is located in the Gualeguaychú Departament, Entre Ríos, in the Pampean Ecorregion. In order to study the water quality, benthonic macroinvertebrates and physical chemical variables were studied, between March and October 2012. Sixteen orders, 1 suborder and 27 invertebrates families were found. The most abundant families were Cochliopidae, Paleomonidae, Caenidae, and Sphaeriidae. BMWP, IBF, IMRP and IBPamp biotic indices and diversity index of Shannon-Weaver were applied. These showed different results suggesting the need for further studies of water bodies of the Pampas Ecorregion and adjustment of indices for the region. The combined application of different rates indicates that the stream shows signs of seasonal organic pollution associated with land use in the basin.Facultad de Ciencias Naturales y Muse

Intrahepatic injection of adenovirus reduces inflammation and increases gene transfer and therapeutic effect in mice

Recombinant adenoviruses (Ad) are among the most extensively used vectors for liver gene transfer. One of the major limitations for the clinical application of these vectors is the inflammatory immune response associated with systemic administration of high dose of virus. We evaluated the effect of Ad administration route on the inflammatory immune response and liver transgene expression. We compared direct intrahepatic injection (IH) with the systemic administration via tail vein (IV). IH injection of Ad resulted in a lower inflammatory response and a higher transgene expression. When a relatively low dose of virus was used, IV administration resulted in no detectable protein expression but production of proinflammatory cytokines. In contrast, IH administration induced high levels of transgene expression and no inflammation, although we detected a transient hypertransaminemia, which fully resolved within days. Furthermore, IH injection resulted in a faster protein expression being more intense at the site of injection, whereas IV administration caused slower but diffuse liver expression. IH injection also reduced the spreading of the virus to other organs. Independently of the route, depletion of Kupffer cells significantly enhanced the transduction efficiency of Ad. This effect was stronger when using IV injection, indicating that IH injection partially overcomes Kupffer cell phagocytic activity. Moreover, the antitumor efficacy of high-capacity-Ad encoding murine interleukin-12 (IL-12) was significantly greater when the vector was administered by IH injection than when given IV. In conclusion, IH injection of adenovirus represents a safe and efficient administration route for clinical applications of gene therapy targeting the liver

Overfeeding, Autonomic Regulation and Metabolic Consequences

The autonomic nervous system plays an important role in the regulation of body processes in health and disease. Overfeeding and obesity (a disproportional increase of the fat mass of the body) are often accompanied by alterations in both sympathetic and parasympathetic autonomic functions. The overfeeding-induced changes in autonomic outflow occur with typical symptoms such as adiposity and hyperinsulinemia. There might be a causal relationship between autonomic disturbances and the consequences of overfeeding and obesity. Therefore studies were designed to investigate autonomic functioning in experimentally and genetically hyperphagic rats. Special emphasis was given to the processes that are involved in the regulation of peripheral energy substrate homeostasis. The data revealed that overfeeding is accompanied by increased parasympathetic outflow. Typical indices of vagal activity (such as the cephalic insulin release during food ingestion) were increased in all our rat models for hyperphagia. Overfeeding was also accompanied by increased sympathetic tone, reflected by enhanced baseline plasma norepinephrine (NE) levels in both VMH-lesioned animals and rats rendered obese by hyperalimentation. Plasma levels of NE during exercise were, however, reduced in these two groups of animals. This diminished increase in the exercise-induced NE outflow could be normalized by prior food deprivation. It was concluded from these experiments that overfeeding is associated with increased parasympathetic and sympathetic tone. In models for hyperphagia that display a continuously elevated nutrient intake such as the VMH-lesioned and the overfed rat, this increased sympathetic tone was accompanied by a diminished NE response to exercise. This attenuated outflow of NE was directly related to the size of the fat reserves, indicating that the feedback mechanism from the periphery to the central nervous system is altered in the overfed state.

¿Afecta Microcystina el fototropismo en plantas vasculares?

La exposición de especies vegetales a cianotoxinas podría tener impacto en sus características morfológicas y fisiológicas. Diversos trabajos han relacionado la inhibición de proteínas fosfatasas (PP1 y PP2A) con alteraciones en importantes procesos celulares; también se han reportado alteraciones estructurales en plantas sometidas a estrés osmótico. Asimismo se han logrado caracterizar alteraciones en la respuesta fototrópica de A. thaliana frente a inhibidores de proteínas fosfatasas. Nuestro objetivo fue estudiar los efectos de [D-Leu1]-Microcystina-LR ([D-Leu1]-MC-LR) sobre el desarrollo y función fototrópica de plántulas de Phaseolus vulgaris.Facultad de Ciencias Exacta

¿Afecta Microcystina el fototropismo en plantas vasculares?

La exposición de especies vegetales a cianotoxinas podría tener impacto en sus características morfológicas y fisiológicas. Diversos trabajos han relacionado la inhibición de proteínas fosfatasas (PP1 y PP2A) con alteraciones en importantes procesos celulares; también se han reportado alteraciones estructurales en plantas sometidas a estrés osmótico. Asimismo se han logrado caracterizar alteraciones en la respuesta fototrópica de A. thaliana frente a inhibidores de proteínas fosfatasas. Nuestro objetivo fue estudiar los efectos de [D-Leu1]-Microcystina-LR ([D-Leu1]-MC-LR) sobre el desarrollo y función fototrópica de plántulas de Phaseolus vulgaris.Facultad de Ciencias Exacta