RESUMEN
The activation of plasminogen plays a crucial role in various extracellular proteolytic events (fibrinolysis, cell migration, ovulation and involution of the mammary gland). In the present study we describe the isolation of the 5' proximal and distal promoter regions of ovine PLAU (urokinase plasminogen activator, u-PA) and SERPIN1 (plasminogen activator inhibitor 1, PAI-1) genes for the first time in ruminants. Analysis of the 5.645kb 5'-flanking region of u-PA revealed a putative TATA-less promoter. In contrast the isolated 2.787kb 5'-flanking region of PAI-1 included a TATA-box. It should be noted that both genes lack the initiator motif around the transcription start site. The two genes share a number of transcription factor binding sites, namely Nuclear Factor-kappa B, Stimulating Protein 1 and Activating protein 1, suggesting co-expression of the two genes. Moreover, additional, not shared, transcription factor binding sites were identified in u-PA and PAI-1. More important of these are the cis-regulatory elements for plasminogen activator inhibitor 2 located in the distal promoter region of u-PA, suggesting an involvement of the other specific inhibitor in the regulation of ovine u-PA gene expression, and the three stress response elements sites present in the proximal and distal promoter of PAI-1. Different genomic fragments of the two 5' flanking regions were directionally cloned into a suitable reporter vector upstream of a promoter-less luciferase gene. Transient transfection into bovine mammary epithelial (BME-UV) cells demonstrated that the regions of -384/+27 and -382/+22 for the u-PA and PAI-1genes, respectively, potentially function as core promoter regions.
Asunto(s)
Inhibidor 1 de Activador Plasminogénico/genética , Regiones Promotoras Genéticas , Ovinos/genética , Activador de Plasminógeno de Tipo Uroquinasa/genética , Animales , Secuencia de Bases , Bovinos , Línea Celular , Clonación Molecular , Femenino , Glándulas Mamarias Animales/metabolismo , Datos de Secuencia Molecular , FN-kappa B/metabolismo , TATA Box/genética , Factor de Transcripción AP-1/metabolismo , Sitio de Iniciación de la TranscripciónAsunto(s)
Células Epiteliales/fisiología , Glándulas Mamarias Animales/fisiología , Ocratoxinas/toxicidad , Animales , Carcinógenos/toxicidad , Bovinos , Células Cultivadas/efectos de los fármacos , Células Cultivadas/fisiología , Células Epiteliales/efectos de los fármacos , Femenino , Glándulas Mamarias Animales/efectos de los fármacos , alfa-Tocoferol/farmacologíaRESUMEN
Over the years, numerous studies have investigated the mechanisms controlling nutrient availability and metabolism in the mammary gland and how dietary interventions can influence these processes. The development of in vivo and in vitro systems made it possible to explore the trafficking and metabolic fate of nutrients and how these are influenced by hormones. To improve the quality and safety of milk products, attention has focused on improving animal health in general and mammary gland health in particular and also on enhancing the milk content of natural bioactive milk components that promote the health of human neonates and adults. In the past, attempts to probe the relationship among nutrition, animal health, and animal products were limited to administering single dietary components and investigating their biochemical and metabolic effects. Today, we have genomics, proteomics, and related technologies that allow us to pursue more holistic investigational strategies. These new technologies are providing new insights into interactions among nutrition, lactation, and product quality. The aim of this paper is to review advances in nutritional support of mammary gland function and health as presented in 14 yr of Biology of Lactation in Farm Animals (BOLFA) meetings.
