An osteoclast (from the Greek words for "bone" and "broken") is a type of bone cell that removes bone tissue by removing the bone's mineralized matrix. This process is known as bone resorption. Osteoclasts and osteoblasts are instrumental in controlling the amount of bone tissue. Osteoblasts form bone; osteoclasts resorb bone. Osteoclasts are formed by the fusion of cells of the monocyte-macrophage cell line. Osteoclasts are characterized by high expression of tartrate resistant acid phosphatase (TRAP) and cathepsin K.
acid ATPase
constitutes a unique form in the family of
tartrate-resistant acid phosphatases and may thus have the
potential as a marker for osteoclast ontogeny and function.
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Calcitonin (CT) receptor (CTR)
a specific marker of the differentiated
osteoclast that is regulated by calcitonin.
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a marker of osteoclast heterogeneity in
osteopetrotic rodents.
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Carboxyterminal Telopeptide of Type 1 Collagen (1CTP)
a marker of osteoclastic bone resorption.
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Cathepsin K
a member of the papain superfamily of
cysteine proteases and plays a pivotal role in osteoclast-mediated
bone resorption.
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a novel cysteine protease previously reported
to be restricted in its expression to osteoclasts.
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predominantly expressed in osteoclasts and is
closely related to cathepsins L.
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CKBB (creatine kinase BB)
predominantly found in brain and is not
normally detected in the blood.
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Creatine kinase-BB in mammalian osteopetrosis
is related to osteoclastic number and size, where it probably
reflects the differentiation and maturation of inactive bone
resorbing cells.
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DAMP (acidotrophic amine
3-(2,4-dinitroanillino)-3'-amino-N-methyldipropylamine)
A low pH marker for visualization of acidic
compartments in cultured osteoclasts.
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ED1
The antibody ED1 stains monocytes,
macrophages and osteoclast in the bone marrow and in the newly
formed fracture callus.
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the combined use of TRAP and ED1 can be used
to identify OC and their precursors in vivo.
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characterizes rat osteoclasts, monocytes, and
macrophages.
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Kat1-antigen (Kat1-Ag)
a reliable immunological marker for
identifying osteoclast precursors of rats: detection of
subpopulations among precursors and initiation of
osteoclastogenesis.
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P1CP (procollagen carboxyterminal propeptide)
an indicator of osteoblastic bone formation.
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RANK
a cell surface marker of human osteoclast
precursors in peripheral blood, bone marrow, and giant cell
tumors of bone.
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Tartrate-resistant acid ATPase
a cytochemical marker for osteoclasts.
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TRAP (tartrate-resistant acid phosphatase)
an important cytochemical marker of
osteoclasts.
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a marker of osteoclast function.
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TRAcP activity alone is not a reliable marker
for osteoclasts in bone marrow cultures.
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Vacuolar-Type Proton Pump (E11)
osteoclast differentiation marker.
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Vitronectin Receptor (VR, VNR)
fully differentiated osteoclast marker.
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Rat osteoclast precursors in vivo express a
vitronectin receptor and a chloride-bicarbonate exchanger.
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Other Osteoclast Markers
calcitonin receptor binding is a
morphological and functional marker of osteoclasts that can be
used in assessing the pathophysiology of disorders of bone
remodeling.
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histochemical demonstration of TR-AP versus
TS-AP on GMA-embedded bone sections by means of a pre-incubation
method can be used as an identification marker of (pre)osteoclasts.
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Osteoclasts derive from hematopoietic stem
cells according to marker, giant lysosomes of beige mice.
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Giant lysosomes, a cytoplasmic marker in
osteoclasts of beige mice.
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Alkaline phosphatase expression during
monocyte differentiation. Overlapping markers as a link between
monocytic cells, dendritic cells, osteoclasts and osteoblasts.
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