title: Bone marrow ablation demonstrates that estrogen plays an important role in osteogenesis and bone turnover via an antioxidative mechanism.
abstract: To assess the effect of estrogen deficiency on osteogenesis and bone turnover in vivo, 8-week-old mice were sham-operated or bilaterally ovariectomized (OVX), and after 8 weeks, mechanical bone marrow ablation (BMX) was performed and newly formed bone tissue was analyzed from 6 days to 2 weeks after BMX. Our results demonstrated that OVX mice following BMX displayed 2 reversed phase changes, one phase observed at 6 and 8 days after BMX delayed osteogenesis accompanied by a delay in osteoclastogenesis, and the other phase observed at 12 and 14 days after BMX increased osteoblastic activity and osteoclastic activity. Furthermore, we asked whether impaired osteogenesis caused by estrogen deficiency was associated with increased oxidative stress, and oxidative stress parameters were examined in bone tissue from sham-operated and OVX mice and OVX mice were administrated with antioxidant N-acetyl-l-cysteine (NAC) or vehicle after BMX. Results demonstrated that estrogen deficiency induced oxidative stress in mouse bone tissue with reduced antioxidase levels and activity, whereas NAC administration almost rescued the abnormalities in osteogenesis and bone turnover caused by OVX. Results from this study indicate that estrogen deficiency resulted in primarily impaired osteogenesis and subsequently accelerated bone turnover by increasing oxidative stress and oxidative stress promises to be an effective target in the process of treatment of postmenopausal osteoporosis.
authors.affiliation: The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China.
authors.forename: Chunmin
authors.initials: C
authors.lastname: Shi
authors.affiliation: The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.affiliation: The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China.
authors.forename: Quanquan
authors.initials: Q
authors.lastname: Yan
authors.affiliation: The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.affiliation: The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China. Electronic address: dsmiao@njmu.edu.cn.
authors.forename: Dengshun
authors.initials: D
authors.lastname: Miao
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001853:Bone Marrow / Q000187:drug effects / Q000601:surgery; D016723:Bone Remodeling / Q000187:drug effects / Q000502:physiology*; D001862:Bone Resorption / Q000378:metabolism; D004195:Disease Models, Animal; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D015663:Osteoporosis, Postmenopausal / Q000503:physiopathology; D010052:Ovariectomy; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000975:Antioxidants; D004967:Estrogens
keywords: Bone marrow ablation; Bone turnover; Estrogen; Osteogenesis; Oxidative stress