Activation of NF-KB signalling and TNFα-expression in THP-1 macrophages by TiAlV- and polyethylene-wear particles

Abstract

Wear particles are believed to induce periprosthetic inflammation which contributes to periprosthetic osteolysis. TNFu plays a pivotal role in the pathogenesis of this process. The molecular mechanisms leading to the development of periprosthetic inflammation with upregulated TNFa expression in monocytic cells in response to different wear particles have yet to be defined. 1n:this study we evaluated the effects of polyethylene-and TiAIV-particles on activation of NF-KB signalling pathways and TNFa biosynthesis and release in monocytic cells with respect to periprosthetic osteoclastogenesis. THP-1 monocytic cells were differentiated to macrophage-like cells and exposed to LPS-detoxified polyethylene and prosthesis-derived TiAlV-particles. TNFa release was analyzed in culture supernatant by ELISA. NF-KB activation was examined by electrophoretic mobility shift assay (EMSA), and NF-KB target promoter activities including transactivation of the TNFa promoter were determined by luciferase reporter gene assays. Differentiated THP-1 macrophages were exposed to increasing numbers of particles for 0, 60, 180 and 360 min. Both, polyethylene-and TiAIV-particles induced a significant activation of both NF-KB and TNFa promoters at 180 min. A significant TNFu release was detected after 360 min exposure to polyethylene-and TiAlV-particles in a dose dependent manner. In comparison, LPS induced a much greater activation of NF-KB and TNFa promoters, and TNFa secretion into the supernatant was strongly induced. These results provide evidence that induction of the NF-KB signal transduction pathway in macrophages plays a major role in initiating and mediating the inflammatory response leading to periprosthetic osteolysis.

Alumina ceramic particles, in comparison with titanium particles, hardly affect the expression of RANK‐, TNF‐α‐, and OPG‐mRNA in the THP‐1 human monocytic cell line

“…Immediately after this activation, the cells were incubated with the particles in a rotational device with the risk that the cells would still be influenced by these mediators, which are capable of affecting RANKL and OPG expression 17, 18. However, some authors are of the opinion that macrophages entering periprosthetic tissue might already be activated and that the way in which Baumann et al19 stimulated their cells could simulate physiological conditions. Some modifications have been made in our study.…”

Calcitonin Gene-Related Peptide Modulates the Production of Pro-Inflammatory Cytokines Associated with Periprosthetic Osteolysis by THP-1 Macrophage-Like Cells

“…LPS was reconstituted in DPBS and stored at -20°C until use. During the experiments, LPS was administered to macrophage-like cells at a final concentration of 1 µg/ml [43]. …”

Periprosthetic osteolysis: genetics, mechanisms and potential therapeutic interventions

“…Baumann and colleagues, 15 using the human monocytic leukemic cell line (THP-1) showed both PE and prosthesis-derived titanium aluminum vanadium (TiAlV) particles induced a significant release of TNF-α after 6 hours of exposure (17-fold for TiAlV and 15-fold for PE, all p < 0.05) and a significant upregulation of RANK mRNA (3.5-fold increase for TiAlV p = 0.040 and 3-fold increase for PE, p = 0.040). They found that OPG mRNA expression was transiently upregulated after exposure to PE and TiAlV particles.…”