Papers by María Soledad Jaureguiberry
American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 2002
The existence of endothelin binding sites on the catecholaminergic neurons of the hypothalamus su... more The existence of endothelin binding sites on the catecholaminergic neurons of the hypothalamus suggests that endothelins (ETs) participate in the regulation of noradrenergic transmission modulating various hypothalamic-controlled processes such as blood pressure, cardiovascular activity, etc. The effects of ET-1 and ET-3 on the neuronal release of norepinephrine (NE) as well as the receptors and intracellular pathway involved were studied in the rat anterior hypothalamus. ET-1 (10 nM) and ET-3 (10 nM) diminished neuronal NE release and the effect blocked by the selective ET type B receptor antagonist BQ-788 (100 nM). Nω-nitro-l-arginine methyl ester (10 μM), methylene blue (10 μM), and KT5823 (2 μM), inhibitors of nitric oxide synthase activity, guanylate cyclase, and protein kinase G, respectively, prevented the inhibitory effects of both ETs on neuronal NE release. In addition, both ETs increased nitric oxide synthase activity. Furthermore, 100 μM picrotoxin, a GABAA-receptor anta...
Environmental Toxicology and Chemistry, 2019
The Pampa Húmeda region in Argentina is characterized by soybean, wheat, and maize production, wi... more The Pampa Húmeda region in Argentina is characterized by soybean, wheat, and maize production, with intensive application of agrochemicals such as herbicides and insecticides. We used a joint probabilistic approach to analyze the probabilities for environmental chlorpyrifos concentrations measured in the Pampa Húmeda to exceed acute or chronic hazardous concentration for 5% of the species (HC5) values estimated from species sensitivity distributions for aquatic species. Chlorpyrifos concentrations in water ranged from 0.0005 to 10.8 µg/L, with a median of 0.013 µg/L. The HC5 limits were 0.0637 µg/L for acute and 0.0007 µg/L for chronic effects. The probabilities for chlorpyrifos environmental concentrations to exceed the HC5 values ranged from 35% (acute effects) to 96% (chronic effects). Water quality criteria (WQC) for the protection of aquatic life were also frequently exceeded (by 48-87%) for both acute and chronic effects. Together with published threshold limit values from mesocosm studies, these data suggest that macroinvertebrate communities can be severely affected by the reported environmental concentrations of chlorpyrifos. Indeed, changes in the macroinvertebrate assemblage in the Pampa Húmeda have been correlated with chlorpyrifos levels in sediments. Nevertheless, the actual impact needs to be ascertained by assessing the recovery rate of macroinvertebrate populations in this region. Considering the HC5 for chronic effects and the threshold limits for macroinvertebrate community level effects, we propose 0.7 ng/L as a new WQC to effectively protect aquatic life from long-term exposure to chlorpyrifos.
Tercera Epoca, Oct 1, 2011
Journal of Membrane Biology, 2010
An excess of intracellular free Cholesterol (Chol) is cytotoxic, and its homeostasis is crucial f... more An excess of intracellular free Cholesterol (Chol) is cytotoxic, and its homeostasis is crucial for cell viability. Apolipoprotein A-I (apoA-I) is a highly efficient Chol acceptor as it activates complex cellular pathways that tend to mobilize and export Chol from cellular depots. Here we hypothesize that membrane composition and/or organization is strongly involved in Chol homeostasis. To test this hypothesis, we constructed a cell line over expressing Stearoyl CoA desaturase (SCD-cells), which modifies plasma membrane (PM) composition by the enrichment of monounsaturated fatty,acids and determined this effect on membrane properties, cell viability and cholesterol homeostasis. PM in SCD-cells has a higher phospholipids/sphingomyelin ratio and is slightly enriched in Chol. These cells showed an increase in the cholesteryl esters/free Chol ratio, they were more resistant to Chol toxicity and in addition, they exported more caveolin than Control cells. The data suggest that cell functionality is preserved by regulating membrane fluidity and Chol exportation and storage.
Acta Biochimica et Biophysica Sinica, 2014
Experimental evidence has suggested that plasma membrane (PM)-associated signaling and hence cell... more Experimental evidence has suggested that plasma membrane (PM)-associated signaling and hence cell metabolism and viability depend on lipid composition and organization. The aim of the present work is to develop a cell model to study the endogenous polyunsaturated fatty acids (PUFAs) effect on PM properties and analyze its influence on cholesterol (Chol) homeostasis. We have previously shown that by using a cell line over-expressing stearoyl-CoA-desaturase, membrane composition and organization coordinate cellular pathways involved in Chol efflux and cell viability by different mechanisms. Now, we expanded our studies to a cell model overexpressing both D5 and D6 desaturases, which resulted in a permanently higher PUFA content in PM. Furthermore, this cell line showed increased PM fluidity, Chol storage, and mitochondrial activity. In addition, human apolipoprotein A-I-mediated Chol removal was less efficient in these cells than in the corresponding control. Taken together, our results suggested that the cell functionality is preserved by regulating PM organization and Chol exportation and homeostasis.
Peptides, 2004
We have previously reported that endothelin 1 and 3 (ET-1, ET-3) through the ET B receptor decrea... more We have previously reported that endothelin 1 and 3 (ET-1, ET-3) through the ET B receptor decrease norepinephrine release in the anterior hypothalamus and activate the nitric oxide (NO) pathway. In the present work we sought to establish the receptors and intracellular mechanisms underlying the increase in nitric oxide synthase (NOS) activity stimulated by ET-1 and ET-3 in the rat anterior hypothalamus. Results showed that ETs-stimulated NOS activity was inhibited by a selective ET B antagonist (BQ-788), but not by a selective ET A antagonist (BQ-610). In addition, NOS activity was not altered in the presence of an ET A agonist (sarafotoxin 6b), but it was enhanced in the presence of a ET B agonist (IRL-1620). Both N-nitro-l-arginine methyl ester (NOS inhibitor), and 7-nitroindazole (neuronal NOS inhibitor) diminished ETs-stimulated NOS activity. The stimulatory effect of ETs on NOS activity was inhibited in the presence of PLC, PKC, PKA and CaMK-II inhibitors (U-73122, GF-109203X, H-89 and KN-62, respectively), and the IP 3 receptor selective antagonist, 2-APB. Our results showed that both ET-1 and ET-3 modulate neuronal NOS activity through the ET B receptor in the rat anterior hypothalamus involving the participation of the PLC-PKC/IP 3 pathway as well as PKA and CaMK-II.
PLoS ONE, 2011
Amyloidoses constitute a group of diseases in which soluble proteins aggregate and deposit extrac... more Amyloidoses constitute a group of diseases in which soluble proteins aggregate and deposit extracellularly in tissues. Nonhereditary apolipoprotein A-I (apoA-I) amyloid is characterized by deposits of nonvariant protein in atherosclerotic arteries. Despite being common, little is known about the pathogenesis and significance of apoA-I deposition. In this work we investigated by fluorescence and biochemical approaches the impact of a cellular microenvironment associated with chronic inflammation on the folding and pro-amyloidogenic processing of apoA-I. Results showed that mildly acidic pH promotes misfolding, aggregation, and increased binding of apoA-I to extracellular matrix elements, thus favoring protein deposition as amyloid like-complexes. In addition, activated neutrophils and oxidative/proteolytic cleavage of the protein give rise to pro amyloidogenic products. We conclude that, even though apoA-I is not inherently amyloidogenic, it may produce non hereditary amyloidosis as a consequence of the pro-inflammatory microenvironment associated to atherogenesis.
2 other HighWire hosted articles: This article has been cited by [PDF] [Full Text] , August 1, 20... more 2 other HighWire hosted articles: This article has been cited by [PDF] [Full Text] , August 1, 2003; 285 (2): R298-R301. Am J Physiol Regulatory Integrative Comp Physiol J. P. Granger Endothelin [PDF] [Full Text] [Abstract] , June 1, 2006; 290 (6): R1515-R1523. Am J Physiol Regulatory Integrative Comp Physiol preoptic area of rats Interleukin-1 mediates endothelin-1-induced fever and prostaglandin production in the including high-resolution figures, can be found at: Updated information and services http://ajpregu.physiology.org/cgi/content/full/283/3/R615 can be found at: and Comparative Physiology American Journal of Physiology -Regulatory, Integrative about Additional material and information http://www.the-aps.org/publications/ajpregu
We have previously reported that endothelin 1 and 3 (ET-1, ET-3) through the ET B receptor decrea... more We have previously reported that endothelin 1 and 3 (ET-1, ET-3) through the ET B receptor decrease norepinephrine release in the anterior hypothalamus and activate the nitric oxide (NO) pathway. In the present work we sought to establish the receptors and intracellular mechanisms underlying the increase in nitric oxide synthase (NOS) activity stimulated by ET-1 and ET-3 in the rat anterior hypothalamus. Results showed that ETs-stimulated NOS activity was inhibited by a selective ET B antagonist (BQ-788), but not by a selective ET A antagonist (BQ-610). In addition, NOS activity was not altered in the presence of an ET A agonist (sarafotoxin 6b), but it was enhanced in the presence of a ET B agonist (IRL-1620). Both N -nitro-l-arginine methyl ester (NOS inhibitor), and 7-nitroindazole (neuronal NOS inhibitor) diminished ETs-stimulated NOS activity. The stimulatory effect of ETs on NOS activity was inhibited in the presence of PLC, PKC, PKA and CaMK-II inhibitors (U-73122, GF-109203X, H-89 and KN-62, respectively), and the IP 3 receptor selective antagonist, 2-APB. Our results showed that both ET-1 and ET-3 modulate neuronal NOS activity through the ET B receptor in the rat anterior hypothalamus involving the participation of the PLC-PKC/IP 3 pathway as well as PKA and CaMK-II.
An excess of intracellular free Cholesterol (Chol) is cytotoxic, and its homeostasis is crucial f... more An excess of intracellular free Cholesterol (Chol) is cytotoxic, and its homeostasis is crucial for cell viability. Apolipoprotein A-I (apoA-I) is a highly efficient Chol acceptor as it activates complex cellular pathways that tend to mobilize and export Chol from cellular depots. Here we hypothesize that membrane composition and/or organization is strongly involved in Chol homeostasis. To test this hypothesis, we constructed a cell line over expressing Stearoyl CoA desaturase (SCD-cells), which modifies plasma membrane (PM) composition by the enrichment of monounsaturated fatty,acids and determined this effect on membrane properties, cell viability and cholesterol homeostasis. PM in SCD-cells has a higher phospholipids/sphingomyelin ratio and is slightly enriched in Chol. These cells showed an increase in the cholesteryl esters/free Chol ratio, they were more resistant to Chol toxicity and in addition, they exported more caveolin than Control cells. The data suggest that cell functionality is preserved by regulating membrane fluidity and Chol exportation and storage.
Experimental evidence has suggested that plasma membrane (PM)-associated signaling and hence cell... more Experimental evidence has suggested that plasma membrane (PM)-associated signaling and hence cell metabolism and viability depend on lipid composition and organization. The aim of the present work is to develop a cell model to study the endogenous polyunsaturated fatty acids (PUFAs) effect on PM properties and analyze its influence on cholesterol (Chol) homeostasis. We have previously shown that by using a cell line over-expressing stearoyl-CoA-desaturase, membrane composition and organization coordinate cellular pathways involved in Chol efflux and cell viability by different mechanisms. Now, we expanded our studies to a cell model over-expressing both D5 and D6 desaturases, which resulted in a permanently higher PUFA content in PM. Furthermore, this cell line showed increased PM fluidity, Chol storage, and mitochondrial activity. In addition, human apolipoprotein A-I-mediated Chol removal was less efficient in these cells than in the corresponding control. Taken together, our results suggested that the cell functionality is preserved by regulating PM organization and Chol exportation and homeostasis.
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Papers by María Soledad Jaureguiberry