Browsing by Author "Contreras Duarte, Susana de las Mercedes"

Now showing 1 - 13 of 13
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    Adenosine receptors: Modulators of lipid availability that are controlled by lipid levels
    (2017) Leiva Mendoza, Andrea Alejandra; Guzmán Gutiérrez, Enrique; Contreras Duarte, Susana de las Mercedes; Fuenzalida Saavedra, Bárbara; Cantin, Claudette; Carvajal, Lorena; Salsoso Rodríguez, M. Rocío; Gutiérrez, Jaime; Pardo, Fabián; Sobrevía Luarte, Luis Alberto
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    Developmental abnormalities in mouse embryos lacking the HDL receptor SR-BI
    (2013) Santander, Nicolás Guillermo; Contreras Duarte, Susana de las Mercedes; Awad, María Fernanda; Lizama, Carlos; Passalacqua, Isabella; Rigotti Rivera, Attilio; Busso, Dolores
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    Disfuncionalidad antioxidante de las lipoproteínas de alta densidad (HDL) en pacientes diabéticos descompensados
    (2015) Awad, Fernanda; Contreras Duarte, Susana de las Mercedes; Molina, Patricia; Quiñones, Verónica; Serrano, V.; Abbott Cáceres, Eduardo Francisco; Maiz, Alberto; Busso, Dolores; Rigotti Rivera, Attilio
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    Foetoplacental epigenetic changes associated with maternal metabolic dysfunction
    (2018) Kerr, Bredford; Leiva Mendoza, Andrea Alejandra; Farías Jofré, Marcelo Enrique; Contreras Duarte, Susana de las Mercedes; Toledo, Fernando; Stolzenbach, Francisca; Silva, Luis; Sobrevía Luarte, Luis Alberto
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    Glucose increases intracellular free Ca2+ in tanycytes via ATP released through connexin 43 hemichannels
    (Wiley Periodicals, Inc., 2012) Orellana Roca, Juan Andrés; Sáez Pedraza, Pablo José; Cortés-Campos, Christian; Elizondo, Roberto J.; Shoji Sánchez, Kenji Fabricio; Contreras Duarte, Susana de las Mercedes; Figueroa, Vania; Velarde Aliaga, María Victoria; Jiang, Jean X.; Nualart, Francisco; Sáez, Juan Carlos; García, María A.
    The ventromedial hypothalamus is involved in regulating feeding and satiety behavior, and its neurons interact with specialized ependymal-glial cells, termed tanycytes. The latter express glucose-sensing proteins, including glucose transporter 2, glucokinase, and ATP-sensitive K+ (KATP) channels, suggesting their involvement in hypothalamic glucosensing. Here, the transduction mechanism involved in the glucose-induced rise of intracellular free Ca2+ concentration ([Ca2+]i) in cultured beta-tanycytes was examined. Fura-2AM time-lapse fluorescence images revealed that glucose increases the intracellular Ca2+ signal in a concentration-dependent manner. Glucose transportation, primarily via glucose transporters, and metabolism via anaerobic glycolysis increased connexin 43 (Cx43) hemichannel activity, evaluated by ethidium uptake and whole cell patch clamp recordings, through a KATP channel-dependent pathway. Consequently, ATP export to the extracellular milieu was enhanced, resulting in activation of purinergic P2Y1 receptors followed by inositol trisphosphate receptor activation and Ca2+ release from intracellular stores. The present study identifies the mechanism by which glucose increases [Ca2+]i in tanycytes. It also establishes that Cx43 hemichannels can be rapidly activated under physiological conditions by the sequential activation of glucosensing proteins in normal tanycytes
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    Gugulipid causes hypercholesterolemia leading to endothelial dysfunction, increased atherosclerosis, and premature death by ischemic heart disease in male mice.
    (2017) Contreras Duarte, Susana de las Mercedes; Leiva Mendoza, Andrea Alejandra; Amigo, Ludwig; Sepulveda, Esteban; Boric P., Mauricio; Quinones, Veronica; Busso, Dolores; Rigotti Rivera, Attilio
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    Hemichannels in the Neurovascular Unit and White Matter Under Normal and Inflamed Conditions
    (2011) Orellana Roca, Juan Andrés; Figueroa, Xavier; Sánchez Riquelme, Helmuth Alberto; Contreras Duarte, Susana de las Mercedes; Velarde Aliaga, María Victoria; Sáez, Juan Carlos
    In the normal brain, cellular types that compose the neurovascular unit, including neurons, astrocytes and endothelial cells express pannexins and connexins, which are protein subunits of two families that form plasma membrane channels. Most available evidence in mammals indicated that endogenously expressed pannexins only form hemichannels, and connexins form both gap junction channels and hemichannels. While gap junction channels connect the cytoplasm of contacting cells and coordinate electrical and metabolic activities, hemichannels communicate intra- and extracellular compartments and serve as diffusional pathways for ions and small molecules. Here, evidence supporting the functional role of hemichannels in the neurovascular unit and white matter under physiological and pathological conditions are reviewed. A sub-threshold acute pathological threatening condition ( e. g., stroke and brain infection) leads to glial cell activation, which maintains an active defense and restores the normal function of the neurovascular unit. However, if the stimulus is deleterious, microglia and the endothelium become overactivated, both releasing bioactive molecules ( e. g., glutamate, cytokines, prostaglandins and ATP) that increase the activity of astroglial hemichannels, reducing the astrocyte neuroprotective functions, and further reducing neuronal cell viability. Moreover, ATP is known to contribute to myelin degeneration of axons. Consequently, hemichannels might play a relevant role in the excitotoxic response of oligodendrocytes observed in ischemia and encephalomyelitis. Regulated changes in hemichannel permeability in healthy brain cells can have positive consequences in terms of paracrine/autocrine signaling, whereas persistent changes in cells affected by neurological disorders can be detrimental. Therefore, blocking hemichannels expressed by glial cells and/or neurons of the inflamed central nervous system might prevent neurovascular unit dysfunction and neurodegeneration.
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    High density lipoprotein cholesterol and proteome in SR-B1 KO mice: lost in precipitation
    (2018) Contreras Duarte, Susana de las Mercedes; Santander Grez, Nicolás Guillermo; Rigotti Rivera, Attilio; Busso, Dolores; Birner-Gruenberger, Ruth.; Wadsack, Christian.
    Abstract Scavenger receptor class B type 1 (SR-B1) plays an essential role in high density lipoprotein (HDL) metabolism. SR-B1 deficient (SR-B1 KO) mice are prone to atherosclerosis and exhibit abnormally large, cholesterol-rich, dysfunctional HDL. In a recent issue of J Transl Med, Cao et al. described results of proteomics analyses of HDL isolated from wild-type (WT) and SR-B1 KO mice using precipitation of large lipoproteins with polyethylene glycol (PEG). They report abnormalities in SR-B1 KO HDL protein components that correlate with HDL function. In this commentary, we describe and discuss the differences in the results published by Cao et al. and those obtained in a recent study from our laboratory using shotgun proteomics of HDL of SR-B1 KO mice isolated by ultracentrifugation. We propose that different HDL purification procedures used may account for the discrepancies observed. We show that SR-B1 KO HDL purification using either PEG or dextran sulfate precipitation results in enrichment of small HDL subclasses, and may therefore underestimate alterations in lipoprotein composition or function. Compared to HDL obtained by ultracentrifugation, HDL isolated by PEG precipitation show a lower ApoE/ApoA-I proportion and reduced cholesterol content. HDL protein components described by Cao et al. or our laboratory are mostly inconsistent: only 33 HDL proteins were detected in both datasets, whereas a significant number of proteins were only identified by Cao et al. (n = 43) or Contreras-Duarte et al. (n = 26) datasets. The relative abundance of HDL-associated peptide and protein levels in WT vs SR-B1 HDL were also highly different in both datasets. This study indicates that caution must be taken when interpreting results from HDL isolated by chemical precipitation.
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    Interferon-gamma and high glucose-induced opening of Cx43 hemichannels causes endothelial cell dysfunction and damage
    (2020) Sáez, Juan Carlos; Contreras Duarte, Susana de las Mercedes; Labra, V. C.; Santibañez, C. A.; Mellado, L. A.; Inostroza, C. A.; Alvear, T. F.; Retamal, M. A.; Velarde Aliaga, María Victoria; Orellana, J. A.
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    Maternal Dyslipidaemia in Pregnancy with Gestational Diabetes Mellitus: Possible Impact in the Foetoplacental Vascular Function and the Lipoprotein in the Neonatal Circulation.
    (2017) Contreras Duarte, Susana de las Mercedes; Carvajal, L.; Fuenzalida Saavedra, Bárbara; Cantin, C.; Sobrevía Luarte, Luis Alberto; Leiva Mendoza, Andrea Alejandra
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    Maternal supraphysiological hypercholesterolemia associates with endothelial dysfunction of the placental microvasculature
    (2018) Fuenzalida Saavedra, Bárbara; Sobrevia, Bastián; Cantin, Claudette; Carvajal, Lorena; Salsoso Rodríguez, M. Rocío; Gutiérrez, Jaime; Contreras Duarte, Susana de las Mercedes; Sobrevía Luarte, Luis Alberto; Leiva Mendoza, Andrea Alejandra
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    Papel protector de las lipoproteínas de alta densidad en sepsis : aspectos básicos e implicancias clínicas
    (2014) Contreras Duarte, Susana de las Mercedes; Varas Arancibia, Pablo Andrés; Awad, F.; Busso, Dolores; Rigotti Rivera, Attilio
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    Role of extracellular vesicles in glioma progression
    (2018) Quezada, Claudia; Torres, Ángelo; Niechi, Ignacio; Uribe, Daniel; Contreras Duarte, Susana de las Mercedes; Toledo, Fernando; San Martín, Rody; Gutiérrez Pérez, Jaime Agustín; Sobrevía Luarte, Luis Alberto