Browsing by Author "Farías Jofré, Marcelo Enrique"

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    Ateroesclerosis subclínica y síndrome metabólico en niños
    (2013) Arnáiz Gómez, Pilar; Barja Y., Salesa; Villarroel del Pino, Luis A.; Domínguez, Angélica; Godoy J., Iván; Castillo Valenzuela, Oscar; Farías Jofré, Marcelo Enrique; Mardones, Francisco
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    Differential immunophenotype of circulating monocytes from pregnant women in response to viral ligands
    (2023) Farías Jofré, Marcelo Enrique; Romero, Roberto; Xu, Yi; Levenson, Dustyn; Tao, Li; Kanninen, Tomi; Galaz, Jose; Arenas-Hernandez, Marcia; Liu, Zhenjie; Miller, Derek; Bhatti, Gaurav; Seyerle, Megan; Tarca, Adi L.; Gomez-Lopez, Nardhy
    Background Viral infections during pregnancy can have deleterious effects on mothers and their offspring. Monocytes participate in the maternal host defense against invading viruses; however, whether pregnancy alters monocyte responses is still under investigation. Herein, we undertook a comprehensive in vitro study of peripheral monocytes to characterize the differences in phenotype and interferon release driven by viral ligands between pregnant and non-pregnant women. Methods Peripheral blood was collected from third-trimester pregnant (n = 20) or non-pregnant (n = 20, controls) women. Peripheral blood mononuclear cells were isolated and exposed to R848 (TLR7/TLR8 agonist), Gardiquimod (TLR7 agonist), Poly(I:C) (HMW) VacciGrade™ (TLR3 agonist), Poly(I:C) (HMW) LyoVec™ (RIG-I/MDA-5 agonist), or ODN2216 (TLR9 agonist) for 24 h. Cells and supernatants were collected for monocyte phenotyping and immunoassays to detect specific interferons, respectively. Results The proportions of classical (CD14hiCD16−), intermediate (CD14hiCD16+), non-classical (CD14loCD16+), and CD14loCD16− monocytes were differentially affected between pregnant and non-pregnant women in response to TLR3 stimulation. The proportions of pregnancy-derived monocytes expressing adhesion molecules (Basigin and PSGL-1) or the chemokine receptors CCR5 and CCR2 were diminished in response to TLR7/TLR8 stimulation, while the proportions of CCR5− monocytes were increased. Such differences were found to be primarily driven by TLR8 signaling, rather than TLR7. Moreover, the proportions of monocytes expressing the chemokine receptor CXCR1 were increased during pregnancy in response to poly(I:C) stimulation through TLR3, but not RIG-I/MDA-5. By contrast, pregnancy-specific changes in the monocyte response to TLR9 stimulation were not observed. Notably, the soluble interferon response to viral stimulation by mononuclear cells was not diminished in pregnancy. Conclusions Our data provide insight into the differential responsiveness of pregnancy-derived monocytes to ssRNA and dsRNA, mainly driven by TLR8 and membrane-bound TLR3, which may help to explain the increased susceptibility of pregnant women to adverse outcomes resulting from viral infection as observed during recent and historic pandemics.
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    Hypoxia increases equilibrative nucleoside transporter 2 activity by a transcriptional independent mechanism in human umbilical vein endothelium
    (2006) Torres, A; San Martin, R; Farías Jofré, Marcelo Enrique; Sobrevía Luarte, Luis Alberto; Casanello Toledo, Paola Cecilia
    Low oxygen tension (hypoxia) reduces adenosine transport in several types of mammalian cells. Adenosine transport is mediated by human equilibrative nucleoside transporter 1 (hENT1) and hENT2 in human umbilical vein endothelium (HUVEC), a fetal cell type that grows under 5% O2 (ie. normoxia for this cell type). We studied whether hypoxia alters hENT2 expression and activity in HUVEC. Methods: Cells were cultured (0-24 h) in 5% or 2% O2 (hypoxia), and [3H]adenosine uptake (125 and 500 μM, 4 μCi/ml, 20 s, 37°C) was measured in absence or presence of 100 nM nitrobenzylthioinosine (NBMPR, hENT1 inhibitor). hENT2 mRNA was quantified by real time RT-PCR, and protein abundance was determined by Western blot. SLC29A2 (for hENT2) promoter activity was measured following transfection (electroporation, 320 V, 30 ms) with pGL3 basic plasmid (firefly/renilla luciferase reporter gene) carrying -1477 bp and -587 bp of the promoter sequence. Results: Hypoxia reduced hENT2 mRNA expression (~55%), and promoter activity (~50%), but did not alter hENT2 protein abundance. Adenosine uptake via hENT2 was increased (2-fold) in hypoxia. Conclusions: Adenosine uptake via hENT2 may be modulated by post-translational mechanisms in hypoxia in HUVEC. Supported by FONDECYT 1030781/1030607/7050030. A Torres holds a School of Medicine research fellowship, and M Farías holds a CONICYT-PhD fellowship.
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    Insulin requires normal expression and signaling of insulin receptor A to reverse gestational diabetes-reduced adenosine transport in human umbilical vein endothelium
    (2015) Westermeier, Francisco; Salomón, Carlos; Farías Jofré, Marcelo Enrique; Arroyo, Pablo; Fuenzalida Saavedra, Bárbara; Sáez, Tamara; Salsoso Rodríguez, M. Rocío; Sanhueza, Carlos; Guzmán-Gutierrez, Enrique; Pardo, Fabián; Leiva Mendoza, Andrea Alejandra; Sobrevía Luarte, Luis Alberto
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    Pre-gestational overweight in guinea pig sows induces fetal vascular dysfunction and increased rate of large and small fetuses
    (2016) Krause Leyton, Bernardo; Herrera, E. A.; Díaz López, F. A.; Farías Jofré, Marcelo Enrique; Uauy, Ricardo; Casanello Toledo, Paola Cecilia
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    Preeclampsia associates with RECK-dependent decrease in human trophoblasts migration and invasion
    (2017) Gutiérrez, Jaime; Aedo, Alejandro; Mora, Jacob; Maldonado, Jorge; Salsoso Rodríguez, M. Rocío; Toledo, Fernando; Farías Jofré, Marcelo Enrique; Pardo, Fabián; Leiva Mendoza, Andrea Alejandra; Sobrevía Luarte, Luis Alberto
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    Reduced Insulin Response in Human Umbilical Vein Endothelial Cells from Pregnancies with Maternal Obesity Is Associated with Activation of PERK Branch of Endoplasmic Reticulum Stress Pathway
    (2013) Farías Jofré, Marcelo Enrique; Westermeier Lafuente, Francisco David; Kusanovic Pivcevic, Juan Pedro; Poblete Lizana, José Andrés; Mardones S., Francisco; Sobrevía Luarte, Luis Alberto
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    The transcriptional repression of equilibrative nucleoside transporter 1 by D-glucose rfsponses to transcription factor Sp1 and ZBP-89 in human foetal endothelium
    (2008) Puebla Aracena, Carlos Alberto; Farías Jofré, Marcelo Enrique; Vega Pizarro, José Luis Eduardo; Pastor-Anglada, M.; Casanello Toledo, Paola Cecilia; Sobrevía Luarte, Luis Alberto
    Objectives: Adenosine is a vasodilator in most vascular beds, an effect depending on its extracellular concentration. Uptake of this nucleoside in human umbilical vein endothelial cells (HUVEC) is mainly mediated by human equilibrative nucleoside transporters 1 (hENT1). hENT1 expression and transport activity are reduced in HUVEC exposed to high D-glucose. Since specific mechanisms for these effects of D-glucose are unknown, we examined the role of Sp1 and BP-89 transcription factors on SLC29A1 (for hENT1) promoter activity in response to D-glucose. Methods: HUVEC from normal pregnancies were isolated and exposed (24 h) to 5 mM (normal) or 25 mM (high) D-glucose. Sp1 protein levels were evaluated by western blot in nuclear fractions. Reporter activity of plasmid constructs containing a wild type promoter region of SLC29A1 (-1114 bp to ATG, pGL3-hENT1-1114), or mutations (by PCR) for Sp1 (-815/-801 bp, pGL3-hENT1-1114mutSp1) or ZBP-89 (-992/-969 bp, pGL3-hENT1-1114mutZBP) or both (-1114 bp, pGL3-hENT1-1114mutSp1/ZBP) binding sites were assayed in cells over-expressing Sp1 (using pCGN-Sp1 vector). Results: Nuclear Sp1 abundance was increased, but pGL3-hENT1-1114 transcriptional activity was reduced by high D-glucose. Sp1 over-expression reduced pGL3-hENT1-1114 transcriptional activity in normal or high D-glucose. The effect of high D-glucose or Sp1 over-expression was absent in pGL3-hENT1-1114mutSp1, pGL3-hENT1-1114mutZBP and pGL3-hENT1-1114mutSp1/ZBP cells. Conclusion: A repression of the SLC29A1 promoter activity by Sp1 and ZBP-89 could explain the reduced hENT1 expression and activity exhibited by HUVEC in high extracellular D-glucose. FONDECYT 1070865/1080534/7070249 (Chile), AECI A/5484/06 (Spain). C Puebla andJL Vega hold CONICYT fellowships. M Farías holds CONICYT and PUC-School of Medicine PhD fellowships.