Endocrine Abstracts

Glucocorticoids (Gcs) act via the intracellular glucocorticoid receptor (GR) to regulate cellular homeostasis. GR is a ligand-activated transcription factor which mediates effects within the nucleus or cytoplasm to regulate genomic or non-genomic events. Localisation of the GR to a specific cellular compartment is therefore an important determinant of the cellular response to Gcs.Live cell imaging of GR trafficking in cells transfected with fluorophore-t...

Circulating levels of prolactin are subject to acute and long-term regulation by many factors including oestrogen and dopamine. We have studied the regulation of prolactin promoter activity in living pituitary cells using transgenic Fischer rats in which reporter gene expression is regulated by the human prolactin gene locus (hPRL-d2EGFP). We have previously identified pulsatile prolactin transcription patterns in living lactotroph cells in fetal tissue, that became stabilised...

Alternative promoters control many genes including prolactin (PRL), which in man is expressed at extra-pituitary sites controlled by an alternative promoter located 5.8 Kbp upstream of the pituitary transcription start site. Previous studies using short promoter fragments may be misleading, as the human hPRL genomic locus has many conserved far-upstream regions. To study the function of the alternative promoter, we engineered a bacterial artificial chromosome (BAC) expressing ...

Pituitary development, in particular the differentiation of anterior pituitary endocrine cells, remains to be fully understood, and may have implications for adult pituitary plasticity and hyperplasia. We have used prolactin-reporter transgenic rats to characterise prolactin transcription during the appearance of newly formed lactotroph cells during fetal development.Transgenic rats with the firefly luciferase reporter gene inserted into exon 1b of a 160...

Mammalian genes display pulsatile transcription dynamics with bursts of expression occurring with variable duration and frequency. Using the human prolactin gene as a model of tissue specific gene regulation, we have characterised the transcription dynamics of this gene in cell lines, primary cells and pituitary tissue slices. Our data indicate that the tissue environment may have an important influence on cellular transcription activity. Cultures of cells from enzymatically d...

Prolactin (PRL) is a peptide hormone produced by the anterior pituitary gland and it is commonly known for its lactogenic and mammotrophic effects. In humans and primates, prolactin is also expressed in extra-pituitary sites where it is associated with numerous biological functions, but its spectrum of expression varies in different species.Hyperprolactinemia-induced osteoporosis is believed to be mediated by hypogonadism, but the expression of the prola...