Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2003-9-3
pubmed:abstractText
Estrogen has protective effects on the skeleton via its inhibition of bone resorption. Mechanisms for these effects and the selectivity to the estrogen receptor alpha (ER alpha) or ER beta are unclear. The purpose of our study was to determine the impact of the ER alpha on skeletal metabolism using murine models with targeted disruption of the ER alpha and beta. Mice generated by homologous recombination and Cre/loxP technology yielding a deletion of the ER alpha exon 3 were evaluated and also crossed with mice with a disruption of the exon 3 of the ER beta to result in double ER alpha and ER beta knockout mice. Skeletal analysis of long bone length and width, radiographs, dual X-ray absorptiometry, bone histomorphometry, micro computerized tomography, biomechanical analysis, serum biochemistry, and osteoblast differentiation were evaluated. Male ER alpha knockout mice had the most dramatic phenotype consisting of reduced bone mineral density (BMD), and bone mineral content (BMC) of femurs at 10 and 16 weeks and 8-9 months of age. Female ER alpha knockout mice also had reduced density of long bones but to a lesser degree than male mice. The reduction of trabecular and cortical bone in male ER alpha knockout mice was statistically significant. Male double ER alpha and ER beta knockouts had similar reductions in bone density versus the single ER alpha knockout mice suggesting that the ER alpha is more protective than the ER beta in bone. In vitro analysis revealed no differences in osteoblast differentiation or mineralized nodule formation among cells from ER alpha genotypes. These data suggest that estrogens are important in skeletal metabolism in males; the ER alpha plays an important role in estrogen protective effects; osteoblast differentiation is not altered with loss of the ER alpha; and compensatory mechanisms are present in the absence of the ER alpha and/or another receptor for estrogen exists that mediates further effects of estrogen on the skeleton.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0300-8207
pubmed:author
pubmed:issnType
Print
pubmed:volume
44 Suppl 1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
250-63
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:12952206-Absorptiometry, Photon, pubmed-meshheading:12952206-Animals, pubmed-meshheading:12952206-Bone Density, pubmed-meshheading:12952206-Bone Diseases, Metabolic, pubmed-meshheading:12952206-Bone and Bones, pubmed-meshheading:12952206-Calcification, Physiologic, pubmed-meshheading:12952206-Disease Models, Animal, pubmed-meshheading:12952206-Estrogen Receptor alpha, pubmed-meshheading:12952206-Estrogen Receptor beta, pubmed-meshheading:12952206-Female, pubmed-meshheading:12952206-Femur, pubmed-meshheading:12952206-Male, pubmed-meshheading:12952206-Mice, pubmed-meshheading:12952206-Mice, Knockout, pubmed-meshheading:12952206-Mice, Transgenic, pubmed-meshheading:12952206-Osteoblasts, pubmed-meshheading:12952206-Receptors, Estrogen, pubmed-meshheading:12952206-Sex Factors, pubmed-meshheading:12952206-Tibia
pubmed:year
2003
pubmed:articleTitle
Transgenic models of metabolic bone disease: impact of estrogen receptor deficiency on skeletal metabolism.
pubmed:affiliation
Department of Periodontics, University of Michigan, Ann Arbor, Michigan, USA. mccauley@umich.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't