RESUMEN
Embryo implantation and development are critically dependent upon the spatial and temporal regulation of angiogenesis and localized vascular permeability. A key mediator of these effects is the endothelial cell mitogen vascular endothelial growth factor (VEGF). VEGF has been shown to promote endometrial vascular permeability, fetal vasculogenesis and placental, fetal and maternal angiogenesis. However, the mechanism through which this regulation occurs in the placenta is poorly understood. This study was conducted to determine if the pro-angiogenic cytokines, TNF-alpha and TGF-beta1, affect VEGF expression in human first trimester trophoblasts. Culture of a first trimester trophoblast cell line (HTR-8/SVneo), in the presence of either TNF-alpha or TGF-beta1, resulted in the expression of significant levels of VEGF in culture. The trophoblast cell line also showed a time-dependent and a dose-dependent increase in VEGF mRNA levels when cultured in the presence of either TNF-alpha or TGF-beta1. These results suggest that both TNF-alpha and TGF-beta1 may regulate the production of VEGF in early gestational trophoblasts and may therefore serve to modulate placental vascular permeability and angiogenesis that are necessary for embryo implantation and placentation.
Asunto(s)
Factores de Crecimiento Endotelial/genética , Linfocinas/genética , ARN Mensajero/biosíntesis , Trofoblastos/metabolismo , Adulto , Northern Blotting , Línea Celular Transformada , Ensayo de Inmunoadsorción Enzimática , Femenino , Regulación de la Expresión Génica , Humanos , Sondas de Oligonucleótidos/química , Embarazo , Primer Trimestre del Embarazo , ARN/análisis , Factor de Crecimiento Transformador beta/farmacología , Trofoblastos/citología , Trofoblastos/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacología , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial VascularRESUMEN
To suppress background hybridization due to repetitive sequence elements, competitor Alu containing clones were isolated from a subclone library of human cosmid clone hP3.1. Pre-annealing of the probe-with this competitor increased the signal well above background. In comparison, the addition of the competitor directly to both the prehybridization and hybridization solution was more effective in reducing background. This dramatically increased the signal to noise ratio of the specific hybridization event. Application to fluorescent in situ hybridization (FISH) is readily apparent.
Asunto(s)
Hibridación de Ácido Nucleico/métodos , Secuencias Repetitivas de Ácidos Nucleicos , Unión Competitiva , Clonación Molecular , HumanosRESUMEN
Swine were divided into four groups of 11 animals at 40 kg body wt. Swine within a group were given a single porcine somatotropin (pST) injection (200 micrograms/kg) or buffer at 0800. Blood, liver (L), latissimus dorsi (LD), semitendinosus (STS), vastus lateralis (VL), dorsal subcutaneous (SQ), and perirenal (PR) adipose tissues were sampled at 0, 1, 2, 4, 8, 12, 16, and 24 h postinjection. Blood urea nitrogen was depressed by 16 h. Insulin was elevated by approximately 350% at 8 h. Lipogenic enzyme activities in adipose tissues were not affected by pST treatment. Insulin-like growth factor I (IGF-I) mRNA levels increased rapidly in SQ, PR, and L to a single pST administration, whereas they increased only slightly in VL. IGF-I mRNA concentrations in LD and STS were unaffected by pST treatment. IGF-I protein content of tissues changed little during the first 24 h postinjection. These data suggest that individual tissues differ in timing and degree of response to pST. Conflicting results reported after pST treatment could, in part, be due to tissue selection for sampling or sample timing.