Dexamethasone treatment affects nuclear glucocorticoid receptor and glucocorticoid response element binding activity in liver of rats (Rattus norvegicus) during aging
Abstract
Aging is associated with marked changes in the biochemical processes of many organs. Basal and glucocorticoid induced of liver nuclear glucocorticoid receptor (GR) on the level of protein expression and DNA-binding activity were investigated at different ages (3, 6, 12, 18 and 24 months old) in two groups of rats in: untreated and dexamethasone treated. The results showed a significant decline of GR protein immunopurified from untreated rats of advanced age. In dexamethasone-treated rats, the quantity of GR protein was lower than in controls at all ages. The interactions of liver nuclear proteins with radioactively labelled synthetic oligonucleotide analogue containing consensus GRE sequence were analysed during aging. The results showed that GRE binding activity demonstrated a decrease both in untreated and in dexamethasone treated rats. However, relative to untreated rats, dexamethasone treatment resulted in a significant increase in GRE binding at all ages, except that of three mont...hs old animals. In conclusion, the observed alterations in GR protein expression and its DNA binding activity may play a role in the changes of the cell response to glucocorticoid during aging.
Keywords:
Aging / Dexamethasone / DNA-protein interaction / Glucocorticoid receptor / GRESource:
Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology, 2007, 148, 4, 463-469Publisher:
- Elsevier Science Inc, New York
Projects:
- Interakcije prirodnih proizvoda i njihovih analoga sa proteinima i nukleinskim kiselinama (RS-142026)
- Signalni putevi delovanja steroidnih hormona i uticaj endogenih i egzogenih faktora na modulaciju procesa u ćelijama sisara (RS-143044)
- Identifikacija specifičnih gena za terapiju kancera (RS-143009)
DOI: 10.1016/j.cbpb.2007.07.090
ISSN: 1096-4959
PubMed: 17761446