Parathyroid hormone responses of cyclic AMP-, serum- and phorbol ester-responsive reporter genes in osteoblast-like UMR-106 cells

Mol Cell Endocrinol. 1998 Apr 30;139(1-2):89-98. doi: 10.1016/s0303-7207(98)00070-7.

Abstract

Parathyroid hormone (PTH) and PTH-related protein interact with a G protein-coupled receptor linked to the activation of adenylyl cyclase and phospholipase C signaling pathways. Regulation by PTH of the expression of three distinct, stably transfected luciferase reporter genes responsive to cAMP (CRE-luc), serum (SRE-luc) and phorbol ester (TRE-luc) has been studied in rat osteoblast-like UMR-106 cells. Maximal 43-fold induction of CRE-luc expression occurred in response to 100 nM rat (r)PTH(1-34) (EC50=0.44 nM), but SRE-luc and TRE-luc remained unaffected. Maximal 2.8- and 3.4-fold inductions of SRE-luc by 10 ng/ml EGF and 100 nM phorbol ester (PMA) were suppressed with 100 nM rPTH(1-34) (IC50=0.04 and 0.15 nM, respectively). Similarly, 7.3-fold induction of TRE-luc by 100 nM PMA was inhibited to 50% with 100 nM rPTH(1-34) (IC50=0.5 nM). Activation of mitogen-activated protein kinase by EGF and PMA was also suppressed by rPTH(1-34). 1 mM 8-Br-cAMP and 0.1 mM forskolin mimicked all the effects of rPTH(1-34). In conclusion, the regulation of target genes by PTH in osteoblast-like UMR-106 cells is mediated by the activation of the cAMP/protein kinase A signaling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8-Bromo Cyclic Adenosine Monophosphate / pharmacology
  • Animals
  • Base Sequence
  • Blood
  • Cell Line
  • Colforsin / pharmacology
  • Cyclic AMP / pharmacology
  • Cyclic AMP-Dependent Protein Kinases / physiology
  • Epidermal Growth Factor / pharmacology
  • Gene Expression Regulation / physiology*
  • Genes, Reporter / genetics*
  • Luciferases / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Molecular Sequence Data
  • Osteoblasts / cytology
  • Osteoblasts / metabolism*
  • Parathyroid Hormone / pharmacology*
  • Rats
  • Regulatory Sequences, Nucleic Acid / genetics*
  • Signal Transduction / genetics
  • Tetradecanoylphorbol Acetate / pharmacology
  • Transfection

Substances

  • Parathyroid Hormone
  • Colforsin
  • 8-Bromo Cyclic Adenosine Monophosphate
  • Epidermal Growth Factor
  • Cyclic AMP
  • Luciferases
  • Cyclic AMP-Dependent Protein Kinases
  • Mitogen-Activated Protein Kinase 1
  • Tetradecanoylphorbol Acetate