Estudio inmunocitoquímico y molecular de cultivo primario de tejido molar / Immunocytochemical and molecular studies with primary cultures of molar tissue

Introducción. La enfermedad trofoblástica gestacional comprende un conjunto de patologías caracterizadas por crecimiento e invasión anómalos del trofoblasto. Las bases moleculares de esta patología son desconocidas, en parte por la dificultad para disponer de modelos biológicos adecuados. Se plantea que el sistema de factores de crecimiento similares a la insulina puede tener un papel fundamental en el desarrollo de la enfermedad. Objetivo. Caracterizar cultivos primarios de placentas de primer trimestre provenientes de pacientes con mola hidatidiforme completa y aborto espontáneo no molar mediante morfología, inmunocitoquímica y expresión diferencial de algunos genes del sistema de factores de crecimiento similares a la insulina. Materiales y métodos. Se empleó inmunocitoquímica para determinar células trofoblásticas y detección por transcripción reversa y reacción en cadena de la polimerasa de genes del sistema de factores de crecimiento similares a la insulina asociados al tipo celular. Resultados. La morfología evidenció heterogeneidad de los cultivos, incluidas células mesenquimales, trofoblásticas y de decidua. El contenido de células de trofoblasto con citoqueratina-7 (marcador específico) estuvo entre 16 y 37 por ciento. La expresión de genes corroboró la presencia de trofoblasto por medio del ARNm del factor II de crecimiento similar a la insulina, en tanto que los transcritos de la hormona de crecimiento variante evidenciaron la presencia de sincitiotrofoblasto. El factor I de crecimiento similar a la insulina y la proteína de unión tipo 1 se relacionaron con células mesenquimales y de decidua. Se observó una mayor expresión del factor II de crecimiento similar a la insulina en tejidos molares en comparación con aborto no molar. Conclusiones. Los resultados mostraron la utilidad de combinar tres metodologías, morfología, inmunocitoquímica y expresión de genes, como herramientas para la caracterización y seguimiento de cultivos placentarios a partir....

Introduction. Gestational trophoblastic disease includes a group of pathologies characterized by abnormal trophoblast growth and invasion. The molecular bases of the disease are largely unknown, due in part to the lack of appropriate biological models. The insulin-like growth factor (IGF) system plays a fundamental role in the growth and development of many tissues and is involved in the progression of several diseases. Objectives. Primary cell cultures derived from first trimester placenta were characterized from patients with complete hydatidiform mole and spontaneous non molar abortion by immunocytochemical and molecular methods. Materials and Methods. The immunocytochemical method used specific markers for trophoblastic cells, whereas RT-PCR was used to identify insulin-like growth factor gene expression. Results. Histochemical staining with hematoxilin-eosin revealed that the cultures contained heterogeneous cell types, including trophoblast and endometrial decidual cells. The ratio of trophoblast cells in the cultures varied between 16% and 37%, as detected by cytokeratine-7 as the specific trophoblast marker. Gene expression analysis corroborated the presence of trophoblasts by detecting insulin-like growth factor II mRNA, whereas GH-V transcripts were correlated with the presence of syncitiotrophoblasts. Insulin-like growth factor I and insulin-like growth factor binding protein 1 mRNAs were related to mesenchyimal and decidual cells, respectively. Higher insulin-like growth factor II expression levels were found in molar tissues in comparison with non-molar abortions. Conclusion. By combining three methodologies—morphology, immunocytochemistry and gene expression, characterization and follow-up of placenta cultures from abnormal tissues is found to facilitate diagnosis.

Serum IGF-I and IGFBP-3 levels in pregnant adolescents in an economically depressed community

The growth hormone (GH) insulin-like growth factor-I (IGF-I) axis is believed to play a role in growth during postnatal and fetal life and is regulated by nutrition. However, very few studies have examined the effects of malnutrition on the regulation of the GH/IGF-I axis in human pregnancy during adolescence. In this study we compared the serum IGF-I and IGFBP-3 levels in a group (n=62) of pregnant adolescents in their second trimester of pregnancy and living in a poor area in the city of Bogotá, with those of a group (n=36) of non-pregnant adolescents from the same area. As reference, a group (n=20) of non-pregnant adolescents from a middle-class district in the same city was utilized. It was observed that the non-pregnant adolescents from the poor area were all below the 3rd percentile and showed significantly (p<0.05) reduced height and weight in comparison with subjects from middle-class area, suggesting growth retardation in this group of subjects. Serum IGF-I and IGFBP-3 levels were significantly (p<0.0001) reduced, in comparison with subjects from the middle-class area, although there was no evidence of delay of puberty based on Tanner stage of sexual development and only subjects at Tanner 5 were included in this study. When the serum concentrations of IGF-I and IGFB-3 in the population of pregnant adolescents were investigated, no differences were found with those observed in the non-pregnant adolescents from the poor district, which means that pregnancy was not accompanied by the elevation in IGF-I levels observed in normal pregnancies. In conclusion, the low circulating IGF-I levels observed in pregnant adolescents could mirror abnormalities on the normal physiology of the GH/IGF-I axis, whose effects on fetal growth are not completely understood