Proceedings of The Physiological Society

University of Bristol (2005) J Physiol 567P, PC56

Poster Communications

Genomic and proteomic analysis of the plasticity within the rat hypothalamo-neurohypophyseal system

Gouraud, Sabine Sandra; Hindmarch, Charles C.T; Yao, Song T; Qiu, Jing; Paton, Julian F.R; Murphy, David;

1. DHB-HW-LINE, University of Bristol, Bristol, United Kingdom. 2. Department of Physiology, Bristol Heart Institute , University of Bristol , Bristol, United Kingdom.

The neuropeptide hormone arginine vasopressin (VP) is produced in the magnocellular neurons of the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei and stored in the posterior pituitary (PP). Dehydration evokes an up-regulation of the expression of the VP gene in magnocellular neurons and a massive release of the peptide from the PP in the circulation to promote water conservation at the level of the kidney. In parallel, a functional remodelling of the hypothalamo-neurohypophyseal system (HNS) is observed but not totally understood. To investigate this activity dependent plasticity of the HNS in terms of coordinated action of cellular and gene networks, we have used transcriptomic (microarray) and proteomic (2D fluorescence difference gel electrophoresis combined with MALDI mass spectrometry) approaches to identify mRNAs and proteins that change in abundance in the SON and the PP from rat (humanely killed at the end of the experiments) as a consequence of 3 days of dehydration. Real-time quantitative PCR and semi-quantitative Western-blotting were used to confirm the data. Using these approaches, we have identified the isoformζof the ubiquitous adapter protein family 14-3-3, known to modulate interactions/functions of components involved in cell signalling and cell cycle control, as being up-regulated in the SON by 1.88 (± 0.27, n=4) -fold at the mRNA level and by 3.38 (± 0.93, n=3) -fold at the protein level. At the same time, levels of RNAs encoding members of the NR4A family of orphan nuclear receptor transcription factors, known as products of immediate early genes induced through multiple signal transduction pathways, appear to be coordinately reduced in PP by 4.16-fold for NR4A1 and 3.76-fold for NR4A2.

Where applicable, experiments conform with Society ethical requirements