Enhanced osteoblast proliferation and collagen gene expression by estradiol

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.85.7.2307· OSTI ID:6827888

Ernest, M; Schmid, Ch; Froesch, E R ^[1]

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1. University Hospital of Zurich (Switzerland)

Estrogens play a crucial role in the development of postmenopausal osteoporosis. However, the mechanism by which estrogens exert their effects on bone is unknown. To examine possible direct effects of 17{beta}-estradiol on bone-forming cells, the authors used pure rat osteoblast-like cells in vitro as a model. Osteoblast-like cells prepared from calvaria of newborn rats were cultured serum-free in methylcellulose-containing medium for 21 days. Osteoblast-like cells proliferate selectively into clonally derived cell clusters of spherical morphorlogy. 17{beta}-Estradiol at concentrations of 0.1 nM and 1 nM enhanced osteoblast-like cell proliferation by 41% and 68% above vehicle-treated controls. The biologically inactive stereoisomer 17{alpha}-estradiol (same concentrations) had no effect. Moreover, the antiestrogen tamoxifen abolished the stimulation of osteoblast-like cell proliferation by 17{beta}-estradiol. After 21 days of culture, RNA was prepared and analyzed in a dot-hybridization assay for the abundance of pro{alpha}1(I) collagen mRNA. Steady-state mRNA levels were increased in cultures treated with 17{beta}-estradiol in a dose-dependent manner with maximal stimulation at 1 nM and 10 nM. At the same concentrations, the percentage of synthesized protein (labeled by ({sup 3}H)proline pulse) that was digestible by collagenase was increased, indicating that 17{beta}-estradiol acts as pretranslational levels to enhance synthesis of bone collagen. These data show that the osteoblast is a direct target for 17{beta}-estradiol.

• OSTI ID: 6827888
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 85:7; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550301* -- Cytology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
AZOLES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMISTRY
BONE CELLS
CARBOXYLIC ACIDS
CELL CULTURES
CELL PROLIFERATION
CHEMISTRY
COLLAGEN
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DISEASES
ESTRADIOL
ESTRANES
ESTROGENS
GENE REGULATION
GROWTH
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HORMONES
HYBRIDIZATION
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MAMMALS
NEONATES
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OSTEOPOROSIS
PATHOGENESIS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PROLINE
PROTEINS
PYRROLES
PYRROLIDINES
RADIOISOTOPES
RATS
RODENTS
SCLEROPROTEINS
SKELETAL DISEASES
SOMATIC CELLS
STEROID HORMONES
STEROIDS
TRITIUM COMPOUNDS
VERTEBRATES