Calcitonin inhibits osteoclast formation in mouse haematopoetic cells independently of transcriptional regulation by receptor activator of NF-{kappa}B and c-Fms.

• The effects of calcitonin (CT) on osteoclast formation and gene expression have been studied in cultured mouse spleen cells and mouse bone marrow macrophages (BMMs). CT inhibited the formation of multinucleated osteoclasts and resorption pits in spleen cell cultures and BMM as well as in CD115(+) CD3(-) CD45R(-)sorted BMM cultures, incubated in the presence of macrophage colony-stimulating factor and receptor activator of NF-kappaB ligand (RANKL). No effect on apoptosis by CT was observed. CT did not affect the mRNA expressions of RANK and c-Fms, or the mRNA expressions of a wide variety of transcription factors and genes important for osteoclast differentiation and activity. CT induced inhibition of tartrate-resistant acid phosphatase (TRAP), positive multinucleated osteoclast formation was not associated with any decrease of total TRAP activity, resulting in a large number of TRAP(+) mononucleated cells in CT-treated cultures. CT did not affect the mRNA expression of dendritic cell-specific transmembrane protein, d2 isoform of vacuolar (H(+)) ATPase v(o) domain, a disintegrin and metalloproteinase domain 8 (ADAM8), ADAM12, DNAX-activating protein or Fc receptor common gamma chain suggested to be involved in fusion of mononucleated osteoclast progenitor cells. The inhibitory effect by CT was mimicked not only by compounds activating cAMP and protein kinase A (PKA) but also by a cAMP analogue activating the exchange protein directly activated by cAMP (Epac) pathway. It is concluded that CT, through cAMP/PKA/Epac cascades, inhibits osteoclast formation and that this effect is not associated with decreased transcription of genes known to be important for osteoclast progenitor cell differentiation, fusion or function.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Odontologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Dentistry (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Fysiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Physiology (hsv//eng)

Keyword

Acid Phosphatase

metabolism

Animals

Bone Marrow Cells

cytology

metabolism

Calcitonin

pharmacology

Cell Differentiation

drug effects

genetics

Cells

Cultured

Cyclic AMP

metabolism

Cyclic AMP-Dependent Protein Kinases

metabolism

Guanine Nucleotide Exchange Factors

metabolism

Hematopoietic Stem Cells

cytology

Isoenzymes

metabolism

Macrophages

cytology

metabolism

Mice

Mice

Inbred Strains

Osteoclasts

cytology

RNA

Messenger

metabolism

Receptor Activator of Nuclear Factor-kappa B

genetics

physiology

Receptor

Macrophage Colony-Stimulating Factor

genetics

physiology

Spleen

cytology

metabolism

Transcription Factors

genetics

Transcription

Genetic

physiology

Publication and Content Type

ref (subject category)

art (subject category)