A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Estrogen responsiveness of bone formation in vitro and altered bone phenotype in aged estrogen receptor-alpha-deficient male and female mice
Tekijät: Parikka V, Peng Z, Hentunen T, Risteli J, Elo T, Väänänen HK, Härkönen P
Julkaisuvuosi: 2005
Journal: European Journal of Endocrinology
Tietokannassa oleva lehden nimi: European journal of endocrinology
Lehden akronyymi: Eur J Endocrinol
Vuosikerta: 152
Numero: 2
Aloitussivu: 301
Lopetussivu: 14
Sivujen määrä: 14
ISSN: 0804-4643
DOI: https://doi.org/10.1530/eje.1.01832
Tiivistelmä
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.\nTo study the effects of long-term ER alpha deficiency, bone phenotype was studied in aged ER alpha knockout (ERKO) mice. In addition, ERKO osteoclasts and osteoblasts were cultured in vitro.\nHistomorphometric 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 wild-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 17 beta-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.\nThese results show altered bone phenotype in ERKO mice and demonstrate the stimulatory effect of estrogen on osteoblasts even in the absence of full-length ER alpha.\nOBJECTIVE\nMETHODS\nDESIGN AND RESULTS\nCONCLUSIONS
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.\nTo study the effects of long-term ER alpha deficiency, bone phenotype was studied in aged ER alpha knockout (ERKO) mice. In addition, ERKO osteoclasts and osteoblasts were cultured in vitro.\nHistomorphometric 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 wild-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 17 beta-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.\nThese results show altered bone phenotype in ERKO mice and demonstrate the stimulatory effect of estrogen on osteoblasts even in the absence of full-length ER alpha.\nOBJECTIVE\nMETHODS\nDESIGN AND RESULTS\nCONCLUSIONS
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