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Effects of Deletion of ER? in Osteoblast-Lineage Cells on Bone Mass and Adaptation to Mechanical Loading Differ in Female and Male Mice.

ABSTRACT: Estrogen receptor alpha (ER?) has been implicated in bone's response to mechanical loading in both males and females. ER? in osteoblast lineage cells is important for determining bone mass, but results depend on animal sex and the cellular stage at which ER? is deleted. We demonstrated previously that when ER? is deleted from mature osteoblasts and osteocytes in mixed-background female mice, bone mass and strength are decreased. However, few studies exist examining the skeletal response to loading in bone cell-specific ER?KO mice. Therefore, we crossed ER? floxed (ER?(fl/fl)) and osteocalcin-Cre (OC-Cre) mice to generate animals lacking ER? in mature osteoblasts and osteocytes (pOC-ER?KO) and littermate controls (LC). At 10 weeks of age, the left tibia was loaded in vivo for 2 weeks. We analyzed bone mass through micro-CT, bone formation rate by dynamic histomorphometry, bone strength from mechanical testing, and osteoblast and osteoclast activity by serum chemistry and immunohistochemistry. ER? in mature osteoblasts differentially regulated bone mass in males and females. Compared with LC, female pOC-ER?KO mice had decreased cortical and cancellous bone mass, whereas male pOC-ER?KO mice had equal or greater bone mass than LC. Bone mass results correlated with decreased compressive strength in pOC-ER?KO female L(5) vertebrae and with increased maximum moment in pOC-ER?KO male femora. Female pOC-ER?KO mice responded more to mechanical loading, whereas the response of pOC-ER?KO male animals was similar to their littermate controls.

SUBMITTER: Melville KM

PROVIDER: S-EPMC4506717 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature

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Effects of Deletion of ERα in Osteoblast-Lineage Cells on Bone Mass and Adaptation to Mechanical Loading Differ in Female and Male Mice.

Melville Katherine M KM Kelly Natalie H NH Surita Gina G Buchalter Daniel B DB Schimenti John C JC Main Russell P RP Ross F Patrick FP van der Meulen Marjolein C H MC

Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research 20150522 8

Estrogen receptor alpha (ERα) has been implicated in bone's response to mechanical loading in both males and females. ERα in osteoblast lineage cells is important for determining bone mass, but results depend on animal sex and the cellular stage at which ERα is deleted. We demonstrated previously that when ERα is deleted from mature osteoblasts and osteocytes in mixed-background female mice, bone mass and strength are decreased. However, few studies exist examining the skeletal response to loadi ...[more]

PMID: 25707500

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Dataset Information

Effects of Deletion of ER? in Osteoblast-Lineage Cells on Bone Mass and Adaptation to Mechanical Loading Differ in Female and Male Mice.

Publications

Effects of Deletion of ERα in Osteoblast-Lineage Cells on Bone Mass and Adaptation to Mechanical Loading Differ in Female and Male Mice.

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