NF-κB Decoy Oligodeoxynucleotide Enhanced Osteogenesis in Mesenchymal Stem Cells Exposed to Polyethylene Particle

Abstract

Excessive generation of wear particles after total joint replacement may lead to local inflammation and periprosthetic osteolysis. Modulation of the key transcription factor NF-kB in immune cells could potentially mitigate the osteolytic process. We previously showed that local delivery of ultrahigh-molecular-weight polyethylene (UHMWPE) particles recruited osteoprogenitor cells and reduced osteolysis. However, the biological effects of modulating the NF-kB signaling pathway on osteoprogenitor/mesenchymal stem cells (MSCs) remain unclear. Here we showed that decoy oligodeoxynucleotide (ODN) increased cell viability when primary murine MSCs were exposed to UHMWPE particles, but had no effects on cellular apoptosis. Decoy ODN increased transforming growth factor-beta 1 (TGF-b1) and osteoprotegerin (OPG) in MSCs exposed to UHMWPE particles. Mechanistic studies showed that decoy ODN upregulated OPG expression through a TGFb1-dependent pathway. By measuring the alkaline phosphatase activity, osteocalcin levels, Runx2 and osteopontin expression, and performing a bone mineralization assay, we found that decoy ODN increased MSC osteogenic ability when the cells were exposed to UHMWPE particles. Furthermore, the cellular response to decoy ODN and UHMWPE particles with regard to cell phenotype, cell viability, and osteogenic ability was confirmed using primary human MSCs. Our results suggest that modulation of wear particle-induced inflammation by NF-kB decoy ODN had no adverse effects on MSCs and may potentially further mitigate periprosthetic osteolysis by protecting MSC viability and osteogenic ability.

NF‐κB decoy oligodeoxynucleotide inhibits wear particle‐induced inflammation in a murine calvarial model

“…Recently, NF- κ B decoy ODN was shown to increase TGF- β 1 and OPG in MSCs exposed to PE particles, and up-regulate OPG expression through a TGF- β 1 dependent pathway. 23 …”

Inflammation, fracture and bone repair

“…However, treatment of aseptic and septic loosening of orthopaedic and dental implants may benefit from considering the role of the immune system [166–168]. For example, blockade of pro-inflammatory mediators such as PGE2 [169], pro-inflammatory cytokines [170], or recruitment of monocyte/macrophage cells by interfering with CCL2/CCR2 axis [171, 172], or inactivation of the pro-inflammatory transcription factor NF-κB [173, 174] has been investigated. Another approach is centered on the modulation of macrophage phenotype from inactivated M0 or pro-inflammatory M1 macrophages toward the pro-remodeling M2 macrophages by using polarizing cytokines [175–177].…”

NF-κB decoy oligodeoxynucleotide mitigates wear particle-associated bone loss in the murine continuous infusion model

“…The activated macrophages secrete many pro-inflammatory cytokines and chemokines and attract the infiltration of more immune cells and osteoclast progenitors [6, 7]. Exposure of mesenchymal stem cells (MSCs) to wear particles interferes with cell viability and osteogenesis through an NF-κB dependent pathway [8]. Together, this suggests the great potential of NF-κB as a therapeutic target to mitigate wear particle-associated bone loss.…”

“…Modulation of NF-κB activity has been applied to immune-related diseases in clinical trials [10]. Our recent studies have demonstrated that application of NF-κB decoy oligodeoxynucleotide (ODN), a synthesized duplex DNA that suppresses NF-κB activity through competitive binding [11], has promising effects to mitigate periprosthetic osteolysis using in vitro and in vivo models [8, 12, 13]. In primary mouse macrophages and the human macrophage cell line THP1, NF-κB decoy ODN simultaneously suppressed the secretion of multiple pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6, etc.)…”

“…)when cells were exposed to ultra-high molecular weight polyethylene (UHMWPE) particles [12]. In primary mouse and human mesenchymal stem cells (MSCs), NF-κB decoy ODN protected cell viability and osteogenic differentiation ability when exposed to UHMWPE particles [8]. In addition, the ratio of receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) secreted by MSCs was also reduced by the decoy ODN, which may suppress osteoclast activation through paracrine regulation [14].…”