Preliminary evidence for impaired estrogen receptor-alpha protein expression in osteoblasts and osteocytes from men with idiopathic osteoporosis

Citation
I. Braidman et al., Preliminary evidence for impaired estrogen receptor-alpha protein expression in osteoblasts and osteocytes from men with idiopathic osteoporosis, BONE, 26(5), 2000, pp. 423-427
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Endocrynology, Metabolism & Nutrition","da verificare
Journal title
BONE
ISSN journal
8756-3282 → ACNP
Volume
26
Issue
5
Year of publication
2000
Pages
423 - 427
Database
ISI
SICI code
8756-3282(200005)26:5<423:PEFIER>2.0.ZU;2-V
Abstract
Although osteoporosis is usually associated with women, 1 in 12 men in the UK have the disease, and a third of these cases are idiopathic, Estrogen is now known to be associated with bone loss in older men, but we found, prev iously, that levels of this hormone were normal in younger cases of male id iopathic osteoporosis (MIO) in the age range 33-61 years. We therefore hypo thesized that their estrogen responses in bone might be defective, through impaired estrogen receptor-alpha (ER)-alpha expression. Consequently, in th e present study, we compared expression of ER-alpha by indirect immunofluor escence, semiquantitative image analysis, and in situ reverse transcription -polymerase chain reaction in bone sections from MIO patients (33-56 years) (N = 7); age-matched control men (N = 7); and, for reference, ovarian ster oid (OS)-replete (N = 7) and OS-deficient women (N = 6), In the control men , 23 +/- 6% (mean +/- SEM) of osteoblasts and 14 +/- 2% of osteocytes expre ssed ER-alpha protein, similar to OS-replete women. Although receptor expre ssion decreased in OS-deficient women, the loss of ER-alpha protein in MIO patients was more severe (1 +/- 0.5% osteocytes, 2 +/- 1% osteoblasts expre ssed receptor); however, ER-alpha messenger RNA (mRNA) was still expressed in controls and MIO patients. Bone loss in these patients may be due to def icient ER-alpha protein expression. (C) 2000 by Elsevier Science Inc. All r ights reserved.