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

Abstract

Wear particles induce periprosthetic inflammation and osteolysis through activation of nuclear factor kappa B (NF-κB), which up-regulates the downstream target gene expression for proinflammatory cytokines in macrophages. It was hypothesized that direct suppression of NF-κB activity in the early phases of this disorder could be a therapeutic strategy for preventing the inflammatory response to wear particles, potentially mitigating osteolysis. NF-κB activity can be suppressed via competitive binding with double stranded NF-κB decoy oligodeoxynucleotides (ODNs) that blocks this transcription factor from binding to the promoter regions of targeted genes. In this murine calvarial study, clinically relevant polyethylene particles (PEs) with/without ODN were subcutaneously injected over the calvarial bone. In the presence of PE particles, macrophages migrated to the inflammatory site and induced tumor necrosis factor alpha (TNF-α) and receptor activator of nuclear factor kappa B ligand (RANKL) expression, resulting in an increase in the number of osteoclasts. Local injections of ODN mitigated the expression of TNF-α, RANKL, and induced the expression of two anti-inflammatory, antiresorptive cytokines: interleukin-1 receptor antagonist and osteoprotegerin. Local intervention with NF-κB decoy ODN in early cases of particle-induced inflammation in which the prosthesis is still salvageable may potentially preserve periprosthetic bone stock.

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

“…The numbers of infiltrated macrophages and activated osteoclasts were reduced by decoy ODN treatment, but there were no significant effects on osteoblast differentiation. Together with our previous in vitro and in vivo studies [8, 12, 13], we demonstrated that NF-κB is a highly potential therapeutic target for peri-prosthetic osteolysis.…”

“…CD11b+ cells were manually counted under a fluorescence microscope (Axio Observer 3.1, Zeiss, Oberkochen, Germany) in 3 randomly selected fields of view. Osteoblasts and osteoclasts were determined as previously described [13]. In brief, osteoblasts were identified by anti-alkaline phosphatase (ALP) antibody (R&D, Minneapolis, MN) with the use of Avidin-biotin complex (Vector Laboratories) immunohistochemistry.…”

“…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.)…”

“…NF-κB decoy ODN was also shown to increase bone mineral density in mouse calvaria exposed to a single application of UHMWPE particles [13]. Furthermore, macrophage infiltration and osteoclast activation were decreased in the mice treated with the decoy ODN.…”

Decreased osteogenesis in mesenchymal stem cells derived from the aged mouse is associated with enhanced NF‐κB activity

“…MSCs can modulate osteoclast activation through paracrine regulation . The expression of RANKL and OPG is highly correlated with NF‐κB activity in MSCs . To investigate whether increased NF‐κB activity in aged MSCs is associated with impaired paracrine regulation, we examined RANKL and OPG mRNA expression in the MSCs in growth or osteogenic media (Days 1, 3, 7, 10, 14, 17, and 21).…”