Research Outputs
Gestational diabetes mellitus is associated with increased pro-migratory activation of vascular endothelial growth factor receptor 2 and reduced expression of vascular endothelial growth factor receptor 1
Placentas from gestational diabetes mellitus (GDM) are often hypervascularized; however, participation of vascular endothelial growth factor (VEGF) and its receptors in this placental adaptation is unclear. We aimed to test whether changes in phosphorylation of tyrosine 951 or tyrosine 1175 (pY951 or pY1175) of the vascular endothelial growth factor receptor 2 (KDR) are associated with the proangiogenic state observed in placentas from GDM. We obtained placental samples from women with normal pregnancies (n = 24) or GDM (n = 18). We measured the relative expression of markers for endothelial cell number (CD31, CD34), VEGF, vascular endothelial growth factor receptor 1 (Flt-1), KDR, pY951 and pY1175 of KDR in placental homogenate. Immunohistochemistry of placental blood vessels were performed using CD34. Proliferation and migration of human umbilical vein endothelial cells (HUVEC) obtained from normal pregnancy and GDM were determined in absence or presence of conditioned medium (CM) harvested from GDM or normoglycemic HUVEC cultures. GDM was associated with more CD31 and CD34 protein compared to normal pregnancy. High number, but reduced area of placental blood vessels was found in GDM. Reduced Flt1 levels (mRNA and protein) are associated with reduced KDR mRNA, but higher KDR protein levels in placentas from GDM. No significant changes in Y951-or Y1175-phosphorylation of KDR in placentas from GDM were found. GDM did not alter proliferation of HUVECs, but enhanced migration. Conditioned medium harvested from GDM HUVEC cultures enhanced KDR protein amount, tube formation capacity and cell migration in HUVEC isolated from normoglycemic pregnancies. The data indicate that GDM is associated with reduced expression of Flt-1 but high pro-migratory activation of KDR reflecting a proangiogenic state in GDM.
Adenosine A(2A) receptor regulates expression of vascular endothelial growth factor in feto-placental endothelium from normal and late-onset pre-eclamptic pregnancies
We aim to investigate whether A2A/nitric oxide-mediated regulation of vascular endothelial growth factor (VEGF) expression is impaired in feto-placental endothelial cells from late-onset pre-eclampsia. Cultures of human umbilical vein endothelial cells (HUVECs) and human placental microvascular endothelial cells (hPMECs) from normal and pre-eclamptic pregnancies were used. Assays by using small interference RNA (siRNA) for A2A were performed, and transfected cells were used for estimation of messenger RNA (mRNA) levels of VEGF, as well as for cell proliferation and angiogenesis in vitro. CGS-21680 (A2A agonist, 24 h) increases HUVEC and hPMEC proliferation in a dose response manner. Furthermore, similar to CGS-21680, the nitric oxide donor, S-nitroso-N-acetyl-penicillamine oxide (SNAP), increased cell proliferation in a dose response manner (logEC50 10−9.2 M). In hPMEC, CGS-21680 increased VEGF protein levels in both normal (∼1.5-fold) and pre-eclamptic pregnancies (∼1.2-fold), an effect blocked by the A2A antagonist, ZM-241385 (10−5 M) and the inhibitor of NO synthase, N ω-nitro-L-arginine methyl ester hydrochloride (L-NAME). Subsequently, SNAP partially recovered cell proliferation and in vitro angiogenesis capacity of cells from normal pregnancies exposed to siRNA for A2A. CGS-21680 also increased (∼1.5-fold) the level of VEGF mRNA in HUVEC from normal pregnancies, but not in pre-eclampsia. Additionally, transfection with siRNA for A2A decrease (∼30 %) the level of mRNA for VEGF in normal pregnancy compared to untransfected cells, an effect partially reversed by co-incubation with SNAP. The A2A-NO-VEGF pathway is present in endothelium from microcirculation and macrocirculation in both normal and pre-eclamptic pregnancies. However, NO signaling pathway seems to be impaired in HUVEC from pre-eclampsia.
Alteraciones en el discurso narrativo en hijos de madres con preeclampsia
Antecedentes y objetivo: Evidencias epidemiológicas han mostrado que la descendencia de mujeres que tuvieron preeclampsia (hipertensión del embarazo) tienen mayor riesgo a desarrollar enfermedades cardiovasculares y alteraciones neurocognitivas, incluyendo en esta última categorÃa alteraciones del lenguaje. Sin embargo, el análisis de las alteraciones del lenguaje en niños nacidos de embarazos con preeclampsia es limitado, por lo tanto, el presente estudio tiene como objetivo investigar el lenguaje oral en hijos de madres con preeclampsia. Método: Se realiza un estudio transversal, previamente aprobado por el Comité Ético CientÃfico del Hospital ClÃnico Herminda Martin de Chillán, Chile. A partir de un universo objetivo de 56 niños, se concretó el análisis en 17 menores, los cuales, a su vez, fueron subdivididos en: cuatro niños nacidos de embarazos normales y tres nacidos de embarazos preeclámpticos en edad preescolar; cinco niños nacidos de embarazos normales y cinco de embarazos preeclámpticos en edad escolar. Se evaluaron de manera general (cribado) los distintos niveles del lenguaje y el discurso narrativo utilizando una adaptación de los test disponibles en la literatura. Resultados: El puntaje total en la evaluación del lenguaje no mostró diferencias estadÃsticamente significativas en los niños de edad preescolar o escolar de ambos grupos de embarazos. Sin embargo, en la evaluación más detallada del discurso narrativo, tanto en su vertiente expresiva como comprensiva, se detectaron diferencias puntuales que se traducen en que un menor porcentaje de niños hijos de madres con preeclampsia en etapa preescolar no logran comprender o expresar parte del mensaje entregado (final de un cuento) en relación con sus respectivos controles por edad. Conclusiones: Los resultados indican que los niños hijos de madres con preeclampsia podrÃan tener una disminución de la comprensión y expresión del discurso narrativo en la edad preescolar. Sugerimos que la preeclampsia ocasionarÃa una reducción de la capacidad verbal oral en la descendencia.