title: Estrogen and its receptor enhance mechanobiological effects in compressed bone mesenchymal stem cells.
abstract: Mechanical stimulation and estrogen have been proven to be two important factors in promoting mesenchymal stem cell activity, which is closely associated with bone formation, mass maintenance and remodeling. However, the superposition effects of mechanical stimulation and estrogen on stem cells remain unknown. It is also unclear if the estrogen receptor (ER) plays only a key role in estrogen signaling or if it is also involved in the mechanotransduction of stem cells. To investigate the role of estrogen and its receptors in the mechanobiological effects in bone mesenchymal stem cells (BMSCs), isolated mesenchymal stem cells from bone marrow were exposed to mechanical pressure under additional estrogen treatment or ER blockade. Cell proliferation was examined using an MTT assay and alkaline phosphatase (ALP) activity was determined by a modified enzyme kinetic method. Alignment of the cytoskeleton was observed by Coomassie brilliant blue staining and F-actin fluorescent staining. Cellular ultrastructure was observed under transmission electron microscope. Expression of ERα was investigated using Western blot analysis. Results indicated that mechanical pressure promoted cell proliferation, ALP activity, ERα expression and F-actin stress fiber formation. Overall, this effect was enhanced by the addition of estrogen and inhibited by ER blockade. We concluded that pressure stimulated proliferation and differentiation capability via F-actin transduction in BMSCs. The effects were enhanced by the addition of estrogen, and the ER plays an important role in regulating mechanobiological effects and the mechanotransduction processes of BMSCs.
authors.affiliation: Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, Xi'an, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Fa-Ming
authors.initials: FM
authors.lastname: Chen
authors.forename: An-Hui
authors.initials: AH
authors.lastname: Wang
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Lv
authors.forename: Shun
authors.initials: S
authors.lastname: Wu
authors.forename: Rui-Ni
authors.initials: RN
authors.lastname: Zhao
mesh_terms: D000199:Actins / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D004967:Estrogens / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000199:Actins; D004967:Estrogens