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Estrogen responsiveness of bone formation in vitro and altered bone phenotype in aged estrogen receptor-alpha-deficient male and female mice

Parikka, V; Peng, ZQ; Hentunen, T; Risteli, J; Elo, T; Vaananen, HK and Härkönen, Pirkko LU (2005) In European Journal of Endocrinology 152(2). p.301-314
Abstract
Objective: Although the beneficial effects of estrogen on bone are well known, the roles of estrogen receptors (ERs) in mediating these effects are not fully understood. Methods: To study the effects of long-term ERalpha deficiency, bone phenotype was studied in aged ERalpha knockout (ERKO) mice. In addition, ERKO osteoclasts and osteoblasts were cultured in vitro. Design and results: Histomorphometric analysis showed that the trabecular bone volume and thickness were significantly increased and the rate of bone formation enhanced in both male and female ERKO mice in comparison to the witd-type animals. In ERKO males, however, the bones were thinner and their maximal bending strengths decreased. Consistent with previous reports, the bones... (More)
Objective: Although the beneficial effects of estrogen on bone are well known, the roles of estrogen receptors (ERs) in mediating these effects are not fully understood. Methods: To study the effects of long-term ERalpha deficiency, bone phenotype was studied in aged ERalpha knockout (ERKO) mice. In addition, ERKO osteoclasts and osteoblasts were cultured in vitro. Design and results: Histomorphometric analysis showed that the trabecular bone volume and thickness were significantly increased and the rate of bone formation enhanced in both male and female ERKO mice in comparison to the witd-type animals. In ERKO males, however, the bones were thinner and their maximal bending strengths decreased. Consistent with previous reports, the bones of knockout mice, especially of female mice, were shorter than those of wild-type mice. In addition, the growth plates were totally absent in the tibiae of aged ERKO females, whereas the growth plate cartilages were detectable in wild-type females as well as in all the males. Analysis of cultured bone marrow cells from 10- to 12-week-old mice demonstrated that 17beta-estradiol could stimulate osteoblastic differentiation of bone marrow cells derived from ERKO mice relatively to the same extent as those derived from wild-type mice. This was demonstrated by increases in synthesis of type I collagen, activity of alkaline phosphatase and accumulation of calcium in cultures. Total protein content was, however, reduced in ERKO osteoblast cultures. Conclusions: These results show altered bone phenotype in ERKO mice and demonstrate the stimulatory effect of estrogen on ostcoblasts even in the absence of full-length ERalpha. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
European Journal of Endocrinology
volume
152
issue
2
pages
301 - 314
publisher
Society of the European Journal of Endocrinology
external identifiers
  • pmid:15745940
  • wos:000227283600020
  • scopus:14644422263
ISSN
1479-683X
DOI
10.1530/eje.1.01832
language
English
LU publication?
yes
id
3df1e7e2-4507-4af1-9f45-cd15eb8de554 (old id 251988)
date added to LUP
2007-08-10 16:10:01
date last changed
2017-08-27 04:13:01
@article{3df1e7e2-4507-4af1-9f45-cd15eb8de554,
  abstract     = {Objective: Although the beneficial effects of estrogen on bone are well known, the roles of estrogen receptors (ERs) in mediating these effects are not fully understood. Methods: To study the effects of long-term ERalpha deficiency, bone phenotype was studied in aged ERalpha knockout (ERKO) mice. In addition, ERKO osteoclasts and osteoblasts were cultured in vitro. Design and results: Histomorphometric analysis showed that the trabecular bone volume and thickness were significantly increased and the rate of bone formation enhanced in both male and female ERKO mice in comparison to the witd-type animals. In ERKO males, however, the bones were thinner and their maximal bending strengths decreased. Consistent with previous reports, the bones of knockout mice, especially of female mice, were shorter than those of wild-type mice. In addition, the growth plates were totally absent in the tibiae of aged ERKO females, whereas the growth plate cartilages were detectable in wild-type females as well as in all the males. Analysis of cultured bone marrow cells from 10- to 12-week-old mice demonstrated that 17beta-estradiol could stimulate osteoblastic differentiation of bone marrow cells derived from ERKO mice relatively to the same extent as those derived from wild-type mice. This was demonstrated by increases in synthesis of type I collagen, activity of alkaline phosphatase and accumulation of calcium in cultures. Total protein content was, however, reduced in ERKO osteoblast cultures. Conclusions: These results show altered bone phenotype in ERKO mice and demonstrate the stimulatory effect of estrogen on ostcoblasts even in the absence of full-length ERalpha.},
  author       = {Parikka, V and Peng, ZQ and Hentunen, T and Risteli, J and Elo, T and Vaananen, HK and Härkönen, Pirkko},
  issn         = {1479-683X},
  language     = {eng},
  number       = {2},
  pages        = {301--314},
  publisher    = {Society of the European Journal of Endocrinology},
  series       = {European Journal of Endocrinology},
  title        = {Estrogen responsiveness of bone formation in vitro and altered bone phenotype in aged estrogen receptor-alpha-deficient male and female mice},
  url          = {http://dx.doi.org/10.1530/eje.1.01832},
  volume       = {152},
  year         = {2005},
}