Regulation of pituitary gene expression by adrenalectomy

ABSTRACT: Overproduction of adrenal hormones causes obesity and hypertension, whereas adrenalectomy (ADX) leads to weight loss and hypotension. The pituitary gland is a major target organ for the adrenal hormones. To identify potential mediators for the effect of ADX on pituitary system regulating weight loss and hypotension, we investigated the effect of ADX on pituitary gene expression using serial analysis of gene expression (SAGE). The numbers of analyzed SAGE tag were 126688 tags for intact mice (n = 51) and 59482 tags for ADX mice (n = 12), which corresponded to 45151 and 21790 distinct tag species, respectively. Thirty-three pituitary genes were differentially expressed between intact and ADX mice. Three genes encoding for pro-opiomelanocortin have been upregulated by ADX. The ADX has induced the gene expression of growth hormone while downregulating an expressed sequence tag similar to (EST) growth hormone. The ADX reduced the expression of genes involved in mitochondrial oxidative phosphorylation, such as NADH dehydrogenase 3 and cytochrome c oxidase 3, whereas neuromedin B gene were dramatically induced. In addition, the ADX increased the expression levels of other three genes involved in hormone release (response to metastatic cancers 1), extracellular matrix (matrix gamma-carboxyglutamate gla protein), and cation transport (solute carrier family member 17). Moreover, one functionally-uncharacterized and 20 novel transcripts were significantly modulated by ADX. Thus the current study has revealed the alterations in the pituitary gene expression that may play key roles in the mechanisms of ADX-induced weight loss and hypotension. Keywords: adrenalectomy, serial analysis of gene expression Rodents and pituitary gland sampling. Male C57BL6 mice were obtained from Charles River Laboratories (St. Constant, QC, Canada), at 12-14 weeks of age. Mice were housed in an air-conditioned room (19-25?) with controlled lighting from 07:15 to 19:15 h and were given free access to food (Lab Rodent Diet No. 5002) and water. One week prior to sampling of pituitary gland, adrenalectomy was performed in mice of ADX groups (n = 12). The ADX mice received sodium chloride (0.9g/dl) in their drinking water after the surgery. All mice were killed between 08:30 and 12:30 by decapitation under isoflurane anesthesia. Brain was removed from the skull and the pituitary gland was immediately dissected. The pituitary gland was immediately frozen in liquid nitrogen, pooled together for each group, and stored at -80? until RNA extraction.

ORGANISM(S): Mus musculus

SUBMITTER: Yuichiro Nishida 

PROVIDER: E-GEOD-5879 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress