Paola Llanos

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Human placental syncytiotrophoblast is the main barrier for materno-fetal exchange. Analysis of transplacental transport involves the study of ion channels in both the maternal-facing microvillous membrane (MVM) and the fetal-facing basal membrane (BM). Difficulties in having access to intact placenta with conventional electrophysiological methods favour(More)
Chloride transport involving conductive pathways participates in numerous epithelial functions, such as membrane voltage maintenance, solute transport and cell volume regulation. Evidence points to involvement of transepithelial chloride transport in such functions in placental syncytiotrophoblast. A molecular candidate for physiologic conductive chloride(More)
Puroindoline-a (PIN-a) and alpha1-purothionin (alpha1-PTH), isolated from wheat endosperm of Triticum aestivum sp., have been suggested to play a role in plant defence mechanisms against phytopathogenic organisms. We investigated their ability to form pores when incorporated into giant liposomes using the patch-clamp technique. PIN-a formed cationic(More)
Insulin signaling includes generation of low levels of H2O2; however, its origin and contribution to insulin-stimulated glucose transport are unknown. We tested the impact of H2O2 on insulin-dependent glucose transport and GLUT4 translocation in skeletal muscle cells. H2O2 increased the translocation of GLUT4 with an exofacial Myc-epitope tag between the(More)
Insulin stimulates glucose uptake in adult skeletal muscle by promoting the translocation of GLUT4 glucose transporters to the transverse tubule (T-tubule) membranes, which have particularly high cholesterol levels. We investigated whether T-tubule cholesterol content affects insulin-induced glucose transport. Feeding mice a high-fat diet (HFD) for 8 wk(More)
Cholesterol and caveolin are integral membrane components that modulate the function/location of many cellular proteins. Skeletal muscle fibers, which have unusually high cholesterol levels in transverse tubules, express the caveolin-3 isoform but its association with transverse tubules remains contentious. Cholesterol removal impairs excitation-contraction(More)
Non-selective cation channels have been identified in the plasma membranes of many different cells. Previous research using fluorescent techniques has demonstrated the presence of cation conductances in membranes from human trophoblast. The purpose of this work was to explore, by electrophysiological methods, a non-selective cation channel in apical(More)
α-Linolenic (ALA) and linoleic (LA) acids are precursors of long chain polyunsaturated fatty acids (LCPUFAs), FAs with important biochemical and physiological functions. In this process, desaturation reactions catalyzed by Δ5- and Δ6-desaturase play a major role, enzymes that are subjected to hormonal and dietary regulation. The aim of this study was to(More)
Insulin resistance is defined as a reduced ability of insulin to stimulate glucose utilization. C57BL/6 mice fed with a high-fat diet (HFD) are a model of insulin resistance. In skeletal muscle, hydrogen peroxide (H2O2) produced by NADPH oxidase 2 (NOX2) is involved in signaling pathways triggered by insulin. We evaluated oxidative status in skeletal muscle(More)
Glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells requires an increase in intracellular free Ca2+ concentration ([Ca2+]). Glucose uptake into β-cells promotes Ca2+ influx and reactive oxygen species (ROS) generation. In other cell types, Ca2+ and ROS jointly induce Ca2+ release mediated by ryanodine receptor (RyR) channels. Therefore, we(More)