What stimulates osteoclast formation?
Interleukin-7 stimulates osteoclast formation by up-regulating the T-cell production of soluble osteoclastogenic cytokines. Blood.
What causes osteoclast differentiation?
RANKL, produced by osteoblasts and bone matrix cells, is the key cytokine that stimulates osteoclast precursor cells to differentiate into mature osteoclasts (7, 25–27). It binds to RANK on the surfaces of osteoclast precursor cells and mature osteoclasts.
What is osteoclast formation?
Discussion. Osteoclasts are terminally differentiated, multinucleated cells formed by the fusion of mononuclear progenitors of the monocyte/macrophage family. OCL activation results in the degradation of the calcified collagenous bone matrix.
How do osteoclasts resorb bone?
Osteoclasts express and target vacuolar-ATPase to the ruffled border membrane where it pumps protons into resorption lacuna to dissolve hydroxyapatite. Matrix metalloproteinases and cysteine proteinases are important proteolytic enzymes in the degradation of collagenous bone matrix.
What cells differentiate into osteoclasts?
Osteoclasts differentiate from cells of the monocyte/macrophage lineage upon stimulation of two essential factors, the monocyte/macrophage colony stimulating factor (M-CSF) and receptor activation of NF-κB ligand (RANKL).
What would happen if you have overactive osteoclasts?
When Paget’s disease is active in several bones, the overactive osteoclasts can release enough calcium from the bone as they break it down to cause an elevated calcium level in the blood. This rare complication might cause fatigue, weakness, loss of appetite, abdominal pain, or constipation.
What is osteoclast resorption?
Bone resorption is resorption of bone tissue, that is, the process by which osteoclasts break down the tissue in bones and release the minerals, resulting in a transfer of calcium from bone tissue to the blood.
How does resorption of bone occur?
The process of resorption (remodeling) involves the removal of hard bone tissue by osteoclasts followed by the laying down of new bone cells by osteoblasts. Resorption releases calcium and repairs micro-damage to bones from normal wears and tears.
Why do osteoclasts destroy bones?
Calcium and Phosphorus Homeostasis II The area of the osteoclast next to bone forms a “ruffled border” consisting of multiple infoldings of the osteoclast cell membrane. It secretes acid and proteases across the ruffled border, and these dissolve the mineral of bone and destroy the organic matrix (see Figure 9.8. 4).