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1.
J Cell Biochem ; 113(7): 2383-96, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22573555

RESUMEN

Cytotrophoblast (CT) cell fusion into a syncytiotrophoblast is obligatory for placentation and mediated by the human endogenous retrovirus (HERV)-W envelope gene Syncytin-1. Abnormal placentation is associated with preeclampsia (PE), HELLP and intrauterine growth restriction (IUGR). In placentogenesis, the MAP-kinase p38α regulates PPARγ/RXRα signaling and target genes, like leptin, resistin, ABCG2, and hCG. The aim of this study was to analyze PPARγ/RXRα signaling and target gene regulation using primary CT cultures, the trophoblastic cell line BeWo and placental tissues from patients with normal and abnormal placentation. CT from four different human control placentae and BeWo cells demonstrated that Syncytin-1, other signaling members and CT cell fusions were regulated with PPARγ/RXRα activators troglitazone and 9-cis retinoic acid, via protein kinase A and p38α inhibition. Significant discordant regulations between CTs and BeWo were found. Two PPARγ/RXRα-response-elements from upstream regulatory elements and the 5'LTR of HERV-W were confirmed with DNA-protein binding assays using nuclear extracts and recombinant PPARγ/RXRα proteins. These promoter elements were validated with luciferase assays in the presence of PPARγ/RXRα modulators. Furthermore, troglitazone or 9-cis retinoic acid treatment of siRNA-PPARγ and siRNA-RXRα transfected BeWo cells proved the requirement of these proteins for Syncytin-1 regulation. Thirty primary abnormal placentae from PE, HELLP and IUGR patients compared to 10 controls showed significant deregulation of leptin RNA and protein, p38α, phospho-p38α, PPARγ, ABCG2, INSL4 and Syncytin-1. Our study characterized PPARγ/RXRα signaling in human CT and cell fusions identifying Syncytin-1 as a new target gene. Based on these results, a disturbed PPARγ/RXRα pathway could contribute to pathological human pregnancies.


Asunto(s)
Productos del Gen env/metabolismo , PPAR gamma/metabolismo , Placentación/fisiología , Proteínas Gestacionales/metabolismo , Receptor alfa X Retinoide/metabolismo , Alitretinoína , Fusión Celular , Línea Celular , Cromanos/farmacología , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Retrovirus Endógenos/genética , Femenino , Retardo del Crecimiento Fetal/metabolismo , Retardo del Crecimiento Fetal/patología , Regulación de la Expresión Génica , Síndrome HELLP/metabolismo , Síndrome HELLP/patología , Humanos , Proteína Quinasa 14 Activada por Mitógenos/antagonistas & inhibidores , PPAR gamma/genética , Placenta/metabolismo , Preeclampsia/metabolismo , Preeclampsia/patología , Embarazo , Interferencia de ARN , ARN Interferente Pequeño , Elementos de Respuesta/genética , Receptor alfa X Retinoide/genética , Transducción de Señal , Tiazolidinedionas/farmacología , Tretinoina/farmacología , Troglitazona , Trofoblastos/metabolismo
2.
J Mol Med (Berl) ; 85(1): 23-38, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17066266

RESUMEN

Endometrial carcinomas (EnCa) predominantly represent a steroid hormone-driven tumor initiated from prestages. The human endogenous retrovirus HERV-W envelope gene Syncytin-1 was significantly increased at the mRNA and protein levels in EnCa and prestages compared to controls. Steroid hormone treatment of primary EnCa cells and cell lines induced Syncytin-1 due to a new HERV-W estrogen response element and resulted in increased proliferation. Activation of the cAMP-pathway also resulted in Syncytin-1 upregulation, but in contrast to proliferation, classic cell-cell fusions similar to placental syncytiotrophoblasts occurred. Cell-cell fusions were also histologically identified in endometrioid EnCa tumors in vivo. Clonogenic soft agar experiments showed that Syncytin-1 is also involved in anchorage-independent colony growth as well as in colony fusions depending on steroid hormones or cAMP-activation. The posttranscriptional silencing of Syncytin-1 gene expression and a concomitant functional block of induced cell proliferation and cell-cell fusion with siRNAs proved the essential role of Syncytin-1 in these cellular processes. TGF-beta1 and TGF-beta3 were identified as main regulative factors, due to the finding that steroid hormone inducible TGF-beta1 and TGF-beta3 inhibited cell-cell fusion, whereas antibody-mediated TGF-beta neutralization induced cell-cell fusions. These results showed that induced TGF-beta could override Syncytin-1-mediated cell-cell fusions. Interactions between Syncytin-1 and TGF-beta may contribute to the etiology of EnCa progression and also help to clarify the regulation of cell-cell fusions occurring in development and in other syncytial cell tumors.


Asunto(s)
Proliferación Celular , Neoplasias Endometriales/patología , Productos del Gen env/metabolismo , Proteínas Gestacionales/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Adulto , Anciano , Anciano de 80 o más Años , Apoptosis , Northern Blotting , Southern Blotting , Western Blotting , Fusión Celular , Neoplasias Endometriales/metabolismo , Femenino , Perfilación de la Expresión Génica , Productos del Gen env/antagonistas & inhibidores , Productos del Gen env/genética , Silenciador del Gen/fisiología , Humanos , Immunoblotting , Persona de Mediana Edad , Proteínas Gestacionales/antagonistas & inhibidores , Proteínas Gestacionales/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Células Tumorales Cultivadas/efectos de los fármacos
3.
JPEN J Parenter Enteral Nutr ; 26(5): 305-9, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12216711

RESUMEN

BACKGROUND: For infusion therapy, polyvinylchloride (PVC)-infusion lines are commonly used. In this study, we examined the temperature dependency and the dynamics of extraction in the time course of infusion. METHODS: PVC-infusion lines used on the newborn ICU were perfused with a typical 24-hour fat infusion. We collected the perfused solution and measured the concentration of DEHP. This procedure was carried out at 27 degrees C and 33 degrees C. In another experiment, we examined the extraction rate in the time course of a 24-hour infusion. The infusion was collected every 4 hours. RESULTS: We discovered that extraction of DEHP depends highly on the surrounding temperature. Whereas at 27 degrees C, the extraction of DEHP was 422.78 microg/mL, the leaching reached 540.78 microg/mL at 33 degrees C under otherwise identical conditions. This is important because the temperature on a newborn ICU is between 31 and 37 degrees C in an incubator. In the other experiment, we found out that the extraction rate rose from 25.44 microg/mL in the first 4 hours to 478.1 microg/mL after 24 hours. CONCLUSIONS: The result of this study is that the actual daily load of DEHP for a 2-kg newborn is 30% higher than measured before. The rate of extraction is dependent on the time of contact between solution and tubing. If PVC-infusion systems are used, solutions should be as cold as possible, and infusion time should be as short as possible.


Asunto(s)
Dietilhexil Ftalato/análisis , Emulsiones Grasas Intravenosas/química , Cloruro de Polivinilo/química , Temperatura , Estabilidad de Medicamentos , Humanos , Recién Nacido , Bombas de Infusión , Unidades de Cuidado Intensivo Neonatal , Cinética
4.
J Mol Med (Berl) ; 88(11): 1143-56, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20664994

RESUMEN

One leading cause of perinatal morbidity and mortality is intrauterine growth restriction (IUGR). Several causes for IUGR have been proposed involving cytotrophoblast dysfunction. Envelope genes of the human endogenous retrovirus (HERV)-W (Syncytin-1), -FRD (Syncytin-2), and -P(b) have fusogenic properties, whereas envelope genes of HERV-R, -V1, and -V2 have putative placental functions. All six HERV envelope genes and three known cellular receptors were analyzed for expression in human control and IUGR placentae (n = 38) and in cultured cytotrophoblasts from control and IUGR (n = 8) placentae. All envelope genes demonstrated downregulation in IUGR compared to control placentae tissues, which were confirmed with cultured cytotrophoblasts. Examination of the Syncytin-1 and Syncytin-2 receptors ASCT-1/-2 and MFSD2 showed that MFSD2 was significantly expressed lower in IUGR than in control placentae and cytotrophoblasts. A reduction of Syncytin-1 protein expression was confirmed for IUGR placentae with immunoblotting and paraffin tissue sections. Embedded placental IUGR tissues showed an overall disorganized syncytiotrophoblast layer with fewer nuclei. Cytotrophoblasts from IUGR placentae demonstrated a lower cell fusion index and nuclei per syncytiotrophoblast in vitro. Fusogenic and non-fusogenic envelope genes are dysregulated in IUGR placentae and may contribute to the etiology of growth restriction in utero.


Asunto(s)
Diferenciación Celular/fisiología , Fusión Celular , Retrovirus Endógenos/genética , Retardo del Crecimiento Fetal , Genes env , Placenta , Peso al Nacer , Células Cultivadas , Femenino , Feto/anatomía & histología , Feto/patología , Feto/fisiología , Productos del Gen env/genética , Productos del Gen env/metabolismo , Humanos , Tamaño de los Órganos , Placenta/citología , Placenta/fisiología , Embarazo , Proteínas Gestacionales/genética , Proteínas Gestacionales/metabolismo , Trofoblastos/citología , Trofoblastos/metabolismo
5.
Mol Reprod Dev ; 75(1): 175-83, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17546632

RESUMEN

Preeclampsia (PE), Hemolysis Elevated Liver Enzymes and Low Platelets (HELLP)-syndrome, and intrauterine growth restriction (IUGR) are associated with abnormal placentation. In early pregnancy, placental cytotrophoblasts fuse and form multinuclear syncytiotrophoblasts. The envelope gene of the human endogenous retrovirus-W, Syncytin, is a key factor for mediating cell-cell fusion of cytotrophoblasts. This study investigated clinical parameters of PE and HELLP-associated IUGR and analyzed the cell-cell fusion index and beta-human chorionic gonadotropin (beta-hCG) secretion of cytotrophoblasts isolated and cultured from placentas of these patients. In addition, we performed absolute quantitation of Syncytin and determined the apoptosis rate in both cultured cytotrophoblasts and placental tissues. Cultured cytotrophoblasts from PE and HELLP-associated IUGR correlated with a pronounced lower cell-cell fusion index, 1.8- and 3.6-fold; less nuclei per syncytiotrophoblast, 1.4- and 2.0-fold; a significantly decreased beta-hCG secretion, 4.3- and 17.2-fold and a reduction of Syncytin gene expression, 8.1 (P = 0.019) and 222.7-fold (P = 0.011) compared with controls, respectively. In contrast, a significantly 2.3-fold higher apoptosis rate was observed in cultured PE/IUGR cytotrophoblasts (P = 0.043). Importantly, Syncytin gene expression in primary placental tissues of PE/IUGR was 5.4-fold lower (P = 0.047) and in HELLP/IUGR 10.6-fold lower (P = 0.019) along with a 1.8- and 1.9-fold significant increase in the apoptosis rate compared with controls, respectively. Low Syncytin expression in both cultured cytotrophoblasts and primary tissues from pathological placentas supports an intrinsic placenta-specific deregulation of cell-cell fusion in the formation of syncytiotrophoblasts leading to increased apoptosis. These processes could contribute to the development and severity of PE and HELLP-associated IUGR.


Asunto(s)
Retardo del Crecimiento Fetal/etiología , Productos del Gen env/deficiencia , Síndrome HELLP/patología , Placenta/patología , Preeclampsia/patología , Proteínas Gestacionales/deficiencia , Trofoblastos/patología , Adulto , Apoptosis , Fusión Celular , Células Cultivadas , Gonadotropina Coriónica Humana de Subunidad beta/genética , Gonadotropina Coriónica Humana de Subunidad beta/metabolismo , Femenino , Retardo del Crecimiento Fetal/metabolismo , Expresión Génica , Productos del Gen env/genética , Síndrome HELLP/metabolismo , Humanos , Placenta/metabolismo , Preeclampsia/metabolismo , Embarazo , Proteínas Gestacionales/genética , Trofoblastos/metabolismo
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