Activation of NF-κB 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. TNFalpha plays a pivotal role in the pathogenesis of this process. The molecular mechanisms leading to the development of periprosthetic inflammation with upregulated TNFalpha expression in monocytic cells in response to different wear particles have yet to be defined. In this study we evaluated the effects of polyethylene- and TiAlV-particles on activation of NF-kappaB signalling pathways and TNFalpha 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. TNFalpha release was analyzed in culture supernatant by ELISA. NF-kappaB activation was examined by electrophoretic mobility shift assay (EMSA), and NF-kappaB target promoter activities including transactivation of the TNFalpha 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 TiAlV-particles induced a significant activation of both NF-kappaB and TNFalpha promoters at 180 min. A significant TNFalpha 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-kappaB and TNFalpha promoters, and TNFalpha secretion into the supernatant was strongly induced. These results provide evidence that induction of the NF-kappaB signal transduction pathway in macrophages plays a major role in initiating and mediating the inflammatory response leading to periprosthetic osteolysis.

Suppression of wear-particle-induced pro-inflammatory cytokine and chemokine production in macrophages via NF-κB decoy oligodeoxynucleotide: A preliminary report

“…Our current studies using PMA stimulated THP-1 cells which were exposed to UHMWPE particles moderately increased TNF-α expression, and is consistent with a previous study with a similar dose (∼1 × 10 9 particles/ml) of polyethylene particles [36]. …”

“…Previous studies using titanium wear particles and differentiated THP-1 cells have shown variable results [35, 36], which may be due to the type and dose of particles and cell differentiation strategy. Our current studies using PMA stimulated THP-1 cells which were exposed to UHMWPE particles moderately increased TNF-α expression, and is consistent with a previous study with a similar dose (∼1 × 10 9 particles/ml) of polyethylene particles [36].…”

Chronic inflammation in biomaterial-induced periprosthetic osteolysis: NF-κB as a therapeutic target

“…In another study, macrophages of the THP-1 cell line were exposed to particles of polyethylene- and titanium alloy, which resulted in significant activation of both NF-κB and TNF-α promoters and TNF-α release in a dose dependent manner. [83]. …”

Myricetin prevents titanium particle-induced osteolysis in vivo and inhibits RANKL-induced osteoclastogenesis in vitro

“…However, we did investigate the inhibition of pro-inflammatory cytokines secretion in vitro. Secondly, UHMWPE is more important to today's joint replacement surgeons because significantly more polyethylene particles (70-90%) appear in tissues around metal-on-polyethylene prostheses [56,57]. However, though metal particles are relatively fewer in the tissue, they are also an important factor contributing to osteolysis [58][59][60].…”