Osteoprotegerin Induces Apoptosis of Osteoclasts and Osteoclast Precursor Cells via the Fas/Fas Ligand Pathway.

ABSTRACT: Osteoprotegerin (OPG) is known to inhibit differentiation and activation of osteoclasts (OCs) by functioning as a decoy receptor blocking interactions between RANK and RANKL. However, the exact role of OPG in the survival/apoptosis of OCs remains unclear. OPG caused increased rates of apoptosis of both OCs and osteoclast precursor cells (OPCs). The expression of Fas and activated caspase-8 was increased by both 20 ng/mL and 40 ng/mL of OPG, but was markedly decreased at 80 ng/mL. Interestingly, we noted that while levels of Fas ligand (FasL) increased with increasing doses of OPG, the soluble form of FasL in the supernatant decreased. The results of a co-immunoprecipitation assay suggested that the decrease of sFasL might be caused by the binding of OPG. This would block the inhibition of

SUBMITTER: Liu W 

PROVIDER: S-EPMC4646684 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature