Browsing by Author "Escudero, C."

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    Adenosine mediates transforming growth factor-beta 1 release in kidney glomeruli of diabetic rats
    (WILEY, 2009) Roa, H.; Gajardo, C.; Troncoso, E.; Fuentealba, V.; Escudero, C.; Yanez, A.; Sobrevia, L.; Pastor Anglada, M.; Quezada, C.; San Martin, R.
    Up regulation of the transforming growth factor-beta 1 (TGF-beta 1) axis has been recognized as a pathogenic event for progression of glomerulosclerosis in diabetic nephropathy. We demonstrate that glomeruli isolated from diabetic rats accumulate up to sixfold more extracellular adenosine than normal rats. Both decreased nucleoside uptake activity by the equilibrative nucleoside transporter 1 and increased AMP hydrolysis contribute to raise extracellular adenosine. Ex vivo assays indicate that activation of the low affinity adenosine A(2B) receptor subtype (A(2B)AR) mediates TGF-beta 1 release from glomeruli of diabetic rats, a pathogenic event that could support progression of glomerulopathy when the bioavailability of adenosine is increased. (C) 2009 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
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    Human equilibrative nucleoside transporters 1 and 2 may be differentially modulated by A(2B) adenosine receptors in placenta microvascular endothelial cells from pre-eclampsia
    (W B SAUNDERS CO LTD, 2008) Escudero, C.; Casanello, P.; Sobrevia, L.
    Pre-eclampsia is associated with elevated maternal blood pressure and proteinuria, altered fetal growth, and increased plasma adenosine concentration in the mother and the fetus. Human equilibrative nucleoside transporters 1 (hENT1) and hENT2 are crucial to maintain physiological plasma levels of adenosine, thus modulating its several biological effects through adenosine receptor activation. However, it is unknown whether hENTs and adenosine receptors are expressed in human placental microvascular endothelium (hPMEC). To assay whether the increased fetal plasma adenosine concentration in pre-eclampsia results from altered hENT-mediated transport, and the potential involvement of adenosine receptors in this phenomenon, we investigated hENTs and A(2A) and A(2B) adenosine receptors expression and function in hPMEC. Cells were isolated and Cultured from normal pregnancies (n = 17) or Pre-eclampsia with adequate-for-gestational age fetuses (n = 7). hENT1, hENT2, A(2A) and A(2B) adenosine receptors were expressed and functional in hPMEC. Extracelhilar adenosine concentration was higher (4-fold) in pre-eclampsia versus normal pregnancies. hPMEC from pre-eclampsia exhibit increased total ;transport (hENT1 + hENT2), and maximal velocity (V-max) for hENT2- (2-fold), but reduced V-max for hENT1-mediated adenosine transport (75%), with no changes in apparent K-m. hENT2 expression was increased (4.5-fold), but hENT1 protein abundance was reduced (80%) in pre-eclampsia. Equally, A2A expression was reduced (50-80%) in pre-eclampsia. CGS-21680 (A(2A) agonist) did not alter hENTs expression or activity, but ZM-241385 (A(2A) antagonist) blocked pre-eclampsia effects and increased hENT1-mechated transport in normal pregnancies. Thus, A(2B) adenosine receptors may differentially modulate hENTs in hPMEC, which could be a mechanism attempting to re-establish physiological extracellular adenosine levels in pre-eclampsia. (C) 2008 Elsevier Ltd. All rights reserved.
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    Increased placental angiogenesis in late and early onset pre-eclampsia is associated with differential activation of vascular endothelial growth factor receptor 2
    (W B SAUNDERS CO LTD, 2014) Escudero, C.; Celis, C.; Saez, T.; San Martin, S.; Valenzuela, F. J.; Aguayo, C.; Bertoglia, P.; Roberts, J. M.; Acurio, J.
    Introduction: Placentas from both early-onset (EOPE) and late-onset pre-eclampsia (LOPE) exhibit signs of underperfusion, which in turn, may be associated with altered angiogenesis. Tyrosine 951 (Y951) and Y1175 phosphorylation of the vascular endothelial growth factor receptor 2 (VEGFR2) induced by VEGF triggers the angiogenesis process. Endothelial markers such as CD31 and CD34 have been used for estimating angiogenic processes in several tissues, including placenta. We asked whether vascular density in placental villi was related to Y951/Y1175 phosphorylation of VEGFR2 in LOPE or EOPE.
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    Insulin Induces Relaxation and Decreases Hydrogen Peroxide-Induced Vasoconstriction in Human Placental Vascular Bed in a Mechanism Mediated by Calcium-Activated Potassium Channels and L-Arginine/Nitric Oxide Pathways
    (2016) Cabrera, L.; Saavedra Zamora, Álvaro Andrés; Rojas, S.; Cid, M.; Valenzuela, C.; Gallegos, D.; Careaga, P.; Basualto, E.; Haensgen, A.; Pena, E.; Rivas, C.; Vera, J.; Gallardo, V.; Zuniga, L.; Escudero, C.; Sobrevía Luarte, Luis Alberto; Wareing, M.; Gonzalez, M.
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    The activity of IKCa and BKCa channels contributes to insulin-mediated NO synthesis and vascular tone regulation in human umbilical vein
    (2020) Rojas, S.; Basualto, E.; Valdivia, L.; Vallejos, N.; Ceballos, K.; Peña, E.; Rivas, C.; Nualart, F.; Guzmán Gutiérrez, E.; Sobrevía Luarte, Luis Alberto; Escudero, C.; Toledo, F.; Cid, M.; González, M.