Adenoviral-mediated over-expression of Brn2 in the rat paraventricular nucleus: No effect on vasopressin or corticotrophin releasing factor RNA levels

Liang Fong Wong, David Murphy*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

7 Citations (Scopus)

Abstract

We have used an over-expression strategy to test the hypothesis that the Class III POU transcription factor Brn2 is rate limiting in the control of the level of expression of the vasopressin (VP) gene in the paraventricular nucleus of the rat hypothalamus. Knockout studies in mice have suggested that Brn2 may contribute to the control of the level of VP gene expression in the adult hypothalamus. However, we show here that in heterologous cell lines, Brn2 transactivates neither the proximal promoter of the rat VP gene, nor a novel reporter construct consisting of the rat VP structural gene and 3 and 2 kbp of upstream and downstream flanking sequences. We hypothesised that this maybe due either to the lack of cis-acting elements within the confines of the reporter vectors used, or to the absence in heterologous cells, of factors required for Brn2 activity. As no cell lines exist that correspond to VP neurons, we devised an adenoviral vector delivery strategy that enabled efficient over-expression of Brn2 in the paraventricular nucleus of the intact rat. Localised over-expression of Brn2 had no effect on VP hnRNA levels. Neither did we detect corticotrophin releasing factor (CRF) mRNA up-regulation by Brn2 over-expression in vivo. This was unexpected as Brn2 transactivates the proximal CRF promoter in vitro. Whilst Brn2 is required for the development of the hypothalamic structures that express VP and CRF, these data suggest that this transcription factor is not required, or is not rate limiting, for expression in the adult.

Original languageEnglish
Pages (from-to)165-175
Number of pages11
JournalMolecular and Cellular Endocrinology
Volume200
Issue number1-2
DOIs
Publication statusPublished - 28 Feb 2003

Keywords

  • Adenoviral vector
  • Brn2
  • Corticotrophin releasing factor
  • Overexpression
  • Paraventricular nucleus
  • Vasopressin

Fingerprint Dive into the research topics of 'Adenoviral-mediated over-expression of Brn2 in the rat paraventricular nucleus: No effect on vasopressin or corticotrophin releasing factor RNA levels'. Together they form a unique fingerprint.

Cite this