|
Year |
2007 |
|---|---|
|
Question Number |
210 |
|
Category |
Orthopaedic Science |
Question
Osteoclastogenesis, a key feature of particle-induced osteolysis, can be inhibited by
1- Tumor necrosis factor alpha (TNFa)
2- Osteoprotegrin
3- IL-2
4- IL-6
5- Receptor activator for NF-Kappa (RANK)-ligand
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Answer (click for answer)
Preferred Answer: 2 – Osteoprotegrin.
IL-6 is a stimulator of osteoclast formation and resorption, it may be an osteoblast mediated signal. TNFa is a potent stimulator of osteoclast progenitor proliferation, fusion, and activation of osteoclastic bone resporption. IL-2 is involved in the lymphocyte limb of the immune system. RANKL is produced by osteoblasts and some tumor cells to induce osteoclast gene expression in precursor cells and activate bone resorptive functions in mature osteoclasts. It may be one of the signals that allow tumor cell-mediated stimulation of bone resorption. Osteoprotegrin is a subtle decoy receptor for RANKL, thereby preventing RANKL interaction with its receptor and inhibiting bone resporption.
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