Takei, H.Pioletti, Dominique P.Kwon, S. Y.Sung, K. L.2006-07-252006-07-252006-07-25200010.1002/1097-4636(200011)52:2<382::AID-JBM19>3.0.CO;2-Vhttps://infoscience.epfl.ch/handle/20.500.14299/23267010951379To clarify the role of tumor necrosis factor (TNF)-alpha on osteoblast functions in the presence of metal particles, two human osteoblast-like cell lines (MG-63 and SaOS-2) were cultured with TNF-alpha in the presence or absence of titanium particles in vitro. A combination of TNF-alpha and titanium particles showed additive effects on inhibition of cell proliferation and alkaline phosphatase production. On the other hand, production of interleukin-6, which is well known to induce osteoclastogenesis and to directly stimulate bone resorption, was additively stimulated by the combination of TNF-alpha and titanium particles. These results suggest that the association of TNF-alpha and titanium particles may play an important role in the pathogenesis of periprosthetic osteolysis through two different pathways: a reduced periprosthetic bone formation due to inhibition of osteoblast proliferation and alkaline phosphatase production, and osteoblast-mediated activation of osteoclastic bone resorption as suggested by the enhancement of interleukin-6 production.*Biocompatible Materials/adverse effectsCell LineHumansInterleukin-6/*biosynthesisOsteoblasts/*drug effects/*metabolismResearch SupportNon-U.S. Gov'tResearch SupportU.S. Gov'tP.H.S.Titanium/*pharmacologyTumor Necrosis Factor-alpha/*pharmacologytext::journal::journal article::research article