OBJECTIVE: Adenovirus expressing small interfering RNA (siRNA)-targeting BMPR-IB was locally administered into the air pouch of mice to improve bone resorption induced by ultra-high molecular weight polyethylene (UHMWPE) particles. METHOD: Air pouches were established on the back of BALB/c mice, followed by the surgical introduction of a section of calvaria from a syngeneic mouse donor. The bone-implanted pouches were stimulated with the UHMWPE suspension. UHMWPE-containing mice were divided into three study groups to receive injections of adenovirus expressing BMPR-IB siRNA (BMPR-IB group), adenovirus expressing missense siRNA, and virus-free culture medium (control group) into the pouches, respectively. The tissues were harvested at 14 days after the treatment for molecular and histological analyses. RESULTS: Adenovirus-mediated BMPR-IB siRNA treatment significantly improved UHMWPE particle-induced bone resorption, reduced TRAP and RANK gene and protein expression levels, and diminished the number of TRAP-positive cells. Furthermore, the BMPR-IB siRNA inhibited osteoclast differentiation by targeting osteoblast for the induction of osteoprotegerin formation and downregulation of receptor for activation of nuclear factor-κB ligand production. CONCLUSIONS: This study suggested that loss of bone morphogenetic protein signaling by BMPR-IB siRNA directs osteoblasts to decrease bone destruction in part by downregulating osteoclastogenesis through the receptor for activation of nuclear factor-κB ligand-osteoprotegerin pathway. Local administration of adenovirus expressing siRNA-targeting BMPR-IB may be a feasible and effective therapeutic candidate to treat or prevent wear debris-associated osteolysis.
OBJECTIVE: Adenovirus expressing small interfering RNA (siRNA)-targeting BMPR-IB was locally administered into the air pouch of mice to improve bone resorption induced by ultra-high molecular weight polyethylene (UHMWPE) particles. METHOD: Air pouches were established on the back of BALB/c mice, followed by the surgical introduction of a section of calvaria from a syngeneic mousedonor. The bone-implanted pouches were stimulated with the UHMWPE suspension. UHMWPE-containing mice were divided into three study groups to receive injections of adenovirus expressing BMPR-IB siRNA (BMPR-IB group), adenovirus expressing missense siRNA, and virus-free culture medium (control group) into the pouches, respectively. The tissues were harvested at 14 days after the treatment for molecular and histological analyses. RESULTS: Adenovirus-mediated BMPR-IB siRNA treatment significantly improved UHMWPE particle-induced bone resorption, reduced TRAP and RANK gene and protein expression levels, and diminished the number of TRAP-positive cells. Furthermore, the BMPR-IB siRNA inhibited osteoclast differentiation by targeting osteoblast for the induction of osteoprotegerin formation and downregulation of receptor for activation of nuclear factor-κB ligand production. CONCLUSIONS: This study suggested that loss of bone morphogenetic protein signaling by BMPR-IB siRNA directs osteoblasts to decrease bone destruction in part by downregulating osteoclastogenesis through the receptor for activation of nuclear factor-κB ligand-osteoprotegerin pathway. Local administration of adenovirus expressing siRNA-targeting BMPR-IB may be a feasible and effective therapeutic candidate to treat or prevent wear debris-associated osteolysis.