Consulta: creatorFacets:"NÚÑEZ,MARCO T"
Registros recuperados: 5
Data/hora: 12/06/2024 10:01:57

Iron and glutathione at the crossroad of redox metabolism in neurons
Provedor de dados: Biological Research
Autores: ARACENA,PAULA; AGUIRRE,PABLA; MUÑOZ,PABLO; NÚÑEZ,MARCO T.
Neurons, as non-dividing cells, encounter a myriad of stressful conditions throughout their lifespan. In particular, there is increasing evidence that iron progressively accumulates in the brain with age and that iron-induced oxidative stress is the cause of several forms of neurodegeneration. Here, we review recent evidence that gives support to the following notions: 1) neuronal iron accumulation leads to oxidative stress and cell death; 2) neuronal survival to iron accumulation associates with decreased expression of the iron import transporter DMT1 and increased expression of the efflux transporter IREG1; and 3) the adaptive process of neurons towards iron-induced oxidative stress includes a marked increase in both the expression of the catalytic...
Tipo: Journal article
Palavras-chave: Neurons; Iron metabolism; Iron accumulation; Oxidative stress; Glutathione metabolism; Neurodegeneration.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000100017

Inhibition of iron and copper uptake by iron, copper and zinc
Provedor de dados: Biological Research
Autores: ARREDONDO,MIGUEL; MARTÍNEZ,RONNY; NÚÑEZ,MARCO T; RUZ,MANUEL; OLIVARES,MANUEL.
Interactions of micronutrients can affect absorption and bioavailability of other nutrients by a number of mechanisms. In aqueous solutions, and at higher uptake levels, competition between elements with similar chemical characteristics and uptake process can take place. The consequences of these interactions may depend on the relative concentrations of the nutrients. In this work, we measure the effects of increasing concentrations of iron, zinc, and copper on iron and copper uptake in Caco-2 cells. Intracellular Fe or Cu levels were affected by incubating with increased concentrations of metals. However, when the cells already had different intracellular metal concentration, the uptake of Fe or Cu was nor affected. In competition studies, we showed that...
Tipo: Journal article
Palavras-chave: Competition; Interaction; Metals; Uptake.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000100011

Effect of iron on the activation of the MAPK/ERK pathway in PC12 neuroblastoma cells
Provedor de dados: Biological Research
Autores: MUÑOZ,PABLO; ZAVALA,GABRIELA; CASTILLO,KAREN; AGUIRRE,PABLA; HIDALGO,CECILIA; NÚÑEZ,MARCO T.
Recent evidence suggests that reactive oxygen species function as second messenger molecules in normal physiological processes. For example, activation of N-Methyl-D-Aspartate receptor results in the production of ROS, which appears to be critical for synaptic plasticity, one of the cellular mechanisms that underlie learning and memory. In this work, we studied the effect of iron in the activation of MAPK/ERK pathway and on Ca2+ signaling in neuronal PC12 cells. We found that iron-dependent generation of hydroxyl radicals is likely to modulate Ca2+ signaling through RyR calcium channel activation, which, in turn, activates the MAPK/ERK pathway. These findings underline the relevance of iron in normal neuronal function.
Tipo: Journal article
Palavras-chave: NMDA receptor; Calcium; Iron; Oxidative stress; MAPK/ERK; Hippocampal slices; Long-term potentiation.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000100021

Hereditary hemochromatosis: An opportunity for gene therapy
Provedor de dados: Biological Research
Autores: EZQUER,FERNANDO; NÚÑEZ,MARCO T; ROJAS,ALEJANDRO; ASENJO,JUAN; ISRAEL,YEDY.
Levels of body iron should be tightly controlled to prevent the formation of oxygen radicals, lipoperoxidation, genotoxicity, and the production of cytotoxic cytokines, which result in damage to a number of organs. Enterocytes in the intestinal villae are involved in the apical uptake of iron from the intestinal lumen; iron is further exported from the cells into the circulation. The apical divalent metal transporter-1 (DMT1) transports ferrous iron from the lumen into the cells, while the basolateral transporter ferroportin extrudes iron from the enterocytes into the circulation. Patients with hereditary hemochromatosis display an accelerated transepithelial uptake of iron, which leads to body iron accumulation that results in cirrhosis, hepatocellular...
Tipo: Journal article
Palavras-chave: Iron; Intestine; Hemochromatosis; Gene therapy; HFE; DMT1; Cirrhosis.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000100014

Regulation of transepithelial transport of iron by hepcidin
Provedor de dados: Biological Research
Autores: MENA,NATALIA P; ESPARZA,ANDRÉS L; NÚÑEZ,MARCO T.
Hepcidin (Hepc) is a 25 amino acid cationic peptide with broad antibacterial and antifungal actions. A likely role for Hepc in iron metabolism was suggested by the observation that mice having disruption of the gene encoding the transcription factor USF2 failed to produce Hepc mRNA and developed spontaneous visceral iron overload. Lately, Hepc has been considered the "stores regulator," a putative factor that signals the iron content of the body to intestinal cells. In this work, we characterized the effect of Hepc produced by hepatoma cells on iron absorption by intestinal cells. To that end, human Hepc cDNA was cloned and overexpressed in HepG2 cells and conditioned media from Hepc-overexpressing cells was used to study the effects of Hepc on intestinal...
Tipo: Journal article
Palavras-chave: Hepcidin; Iron absorption; DMT1; Caco-2 cells.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000100022