title: Estrogen receptor alpha genotype confers interindividual variability of response to estrogen and testosterone in mesenchymal-stem-cell-derived osteoblasts.
abstract: Hormone replacement therapy is effectively used to prevent postmenopausal bone loss. Variation in response to the therapy is, however, frequently seen. In addition, the direct effects of sex steroids on isolated human bone marrow stromal cells have been reported to vary depending on the donor, but the biological mechanisms are not understood. The aim of this study was to investigate the effects of 17beta-estradiol (E2) and testosterone in human-bone-marrow-derived mesenchymal stem cell (MSC) cultures from both female and male donors of various ages. The osteoblast differentiation capacity and activity of the MSCs were quantified in vitro by measuring alkaline phosphatase activity and calcium deposition. We show here that also the osteoblast responses of MSCs to sex hormones vary widely depending on the donor. When the results from all donors were analyzed together, treatment with E2 increased calcium deposition significantly by MSCs of both sexes but ALP activity only in the male MSCs. Testosterone had no effect on ALP activity nor calcium deposition in either sex. To further characterize the individual variation, we investigated estrogen receptor alpha PvuII restriction site polymorphism with PCR. Restriction fragment-length polymorphism was assigned as P or non-P, P signifying the absence of the restriction site. Our results indicate that higher basal osteoblast differentiation capacity of MSCs is associated with the presence of the P allele in females, whereas higher response to sex steroids treatment is associated with the non-P allele. These results could help explain the contradictory effects of E2 on osteoblasts in vitro and might also provide new insights to understanding the differences in responses to hormone replacement therapy.
authors.affiliation: Department of Surgery, Clinical Research Center, University of Oulu, FI-90014 Oulun Yliopisto, Finland. Electronic address: haleskel@paju.oulu.fi.
authors.forename: Hannu-Ville
authors.initials: HV
authors.lastname: Leskelä
authors.affiliation: Department of Medical Biochemistry, University of Kuopio, Kuopio, Finland.
authors.forename: Anu
authors.initials: A
authors.lastname: Olkku
authors.affiliation: Department of Surgery, Clinical Research Center, University of Oulu, FI-90014 Oulun Yliopisto, Finland.
authors.forename: Siri
authors.initials: S
authors.lastname: Lehtonen
authors.affiliation: Department of Medical Biochemistry, University of Kuopio, Kuopio, Finland.
authors.forename: Anitta
authors.initials: A
authors.lastname: Mahonen
authors.affiliation: Department of Anatomy and Cell Biology, University of Oulu, Oulu, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Koivunen
authors.affiliation: Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland.
authors.forename: Miia
authors.initials: M
authors.lastname: Turpeinen
authors.affiliation: Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland; Department of Chemistry, University of Oulu, Oulu, Finland.
authors.forename: Jouko
authors.initials: J
authors.lastname: Uusitalo
authors.affiliation: Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland.
authors.forename: Olavi
authors.initials: O
authors.lastname: Pelkonen
authors.affiliation: Hormos Medical Ltd, Turku, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Kangas
authors.affiliation: Department of Medicine, Division of Hematology-Oncology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
authors.forename: Katri
authors.initials: K
authors.lastname: Selander
authors.affiliation: Department of Surgery, Clinical Research Center, University of Oulu, FI-90014 Oulun Yliopisto, Finland.
authors.forename: Petri
authors.initials: P
authors.lastname: Lehenkari
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001141:Aromatase / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D047628:Estrogen Receptor alpha / Q000235:genetics* / Q000378:metabolism; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D008875:Middle Aged; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects; D012150:Polymorphism, Restriction Fragment Length; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D047628:Estrogen Receptor alpha; D004967:Estrogens; D013739:Testosterone; D015067:17-Hydroxysteroid Dehydrogenases; D001141:Aromatase