Two distinct cellular mechanisms of osteoclast formation and bone resorption in periprosthetic osteolysis

Up to 20% of patients with total joint arthroplasty will develop radiographic evidence of aseptic loosening (AL), which most likely results from an inflammatory response to billions of wear debris shed from the implant. Our previous work has demonstrated that erythromycin (EM), a macrolide antibiotic, inhibits wear debris-induced inflammatory osteoclastogenesis through the reduction of cytokine production and osteoclast differentiation, both of which involve the NF-kB pathway. The aim of the current study was to determine whether EM inhibits wear debris-induced inflammatory osteolysis in a murine osteolysis model. Ultrahigh molecular-weight polyethylene (UHMWPE) debris was introduced into established air pouches on BALB/c mice, followed by implantation of calvaria bone from syngeneic littermates. EM (2 mg/kg/day) was given to mice intraperitoneally 2 days before UHMWPE introduction and maintained until the sacrifice of the mice. Mice with and without EM treatment, as well as control mice injected with saline alone were included in this study. Pouch tissues were collected 14 days after UHMWPE inoculation for molecular and histology analysis. Our findings indicate that: (1) EM reduced UHMWPE-induced tissue inflammation, including the diminished pouch membrane thickness, reduced inflammatory cellular infiltration, and lowered IL-1b and TNF-a expression (mRNA and protein); (2) EM inhibited UHMWPE-induced osteoclastogenesis, with reduced gene activation of RANK, RANKL, and CPK, and diminished RANKL expression in UHMWPE stimulated pouches, and (3) EM markedly reduced the number of TRAP þ cells in pouch tissues, and protected against bone collagen depletion. In conclusion, this study provides the evidence that EM inhibits the UHMWPE particles-induced inflammatory osteolysis in a murine model, and represents a promising therapeutic candidate for the prevention and treatment of AL. ß

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Erythromycin inhibits wear debris‐induced inflammatory osteolysis in a murine model

Ren

Peng

et al. 2005

“…The tissue has a high synthetic activity 1 and may contribute to bone lysis, which was first described in 1977. 2 Wear particles 3,4 trigger the invasion of inflammatory cells into the interface tissue. Some cell populations of the interface tissue release matrix-degrading enzymes 5 and cytokines.…”

Section: Introductionmentioning

confidence: 99%

Interface membrane fibroblasts around aseptically loosened endoprostheses express MMP‐13

Wagner

Gollwitzer

Wernicke

et al. 2007

The objective of this article was to assess whether matrix metalloproteinase-13 (MMP-13) is produced by cells of the peri-implant interface tissues and to further characterize these cells. Tissue specimens were collected from the bone-prosthesis interface at the time of revision surgery of clinically loosened hip and knee arthroplasties (n ¼ 27). Synovial tissues from osteoarthritic patients and young patients with mild joint deformity were used as controls (n ¼ 6). Tissue samples were fixed in 4% PFA, decalcified with EDTA, and embedded in paraffin. Sections (4 mm) were stained with hematoxylin/eosin and for the osteoclastic marker enzyme tartrate resistant acid phosphatase. Monocytes/macrophages were characterized with a monoclonal antibody against CD68 and mRNAs encoding MMP-13 and a 1 collagen I (COL1A1) were detected by in situ hybridization. Cells expressing transcripts encoding MMP-13 were found in 70% of the interface tissues. These cells colocalized with a cell population expressing COL1A1 mRNA, and were fibroblastic in appearance. MMP-13 expressing cells were found in the close vicinity of osteoclasts and multinuclear giant cells. No signals for transcripts encoding MMP-13 were detected in multinuclear giant cells or in osteoclasts. Control tissues were negative for transcripts encoding MMP-13 mRNA. Fibroblasts of the interface from aseptically loosened endoprostheses selectively express MMP-13. By the expression and the release of MMP-13, these fibroblastic cells may contribute to the local degradation of the extracellular matrix and to bone resorption. ß

“…10 However, there is controversy as to whether TNFa can stimulate myeloid osteoclastogenesis by a RANK/RANKL independent mechanism. 11,12 Sabokbar et al 13 found that the addition of TNFa to macrophages isolated from human loosening periprosthetic tissues induced the formation of TRAP þ multinucleated osteoclasts capable of extensive lacunar resorption. TNFa-induced osteoclastogenesis cannot be blocked by the treatment with either osteoprotegerin (OPG) or RANK:Fc IgG (which inhibit RANKL-induced osteoclastogenesis), suggesting this process is distinct from the RANK/RANKL signaling pathway.…”

Section: Introductionmentioning

confidence: 99%

Implant wear induces inflammation, but not osteoclastic bone resorption, in RANK^–/– mice

Ren

Peng

et al. 2006

Signaling of RANK (receptor activator of nuclear factor kappa B) through its ligand RANKL appears critical in osteolysis associated with aseptic loosening (AL). The purpose of this study was to investigate the role of RANK in a murine osteolysis model developed in RANK knockout (RANK À/À ) mice. Ultra high molecular weight polyethylene (UHMWPE) debris was introduced into established air pouches on RANK À/À mice, followed by implantation of calvaria bone from syngeneic littermates. Wild type C57BL/6 (RANK þ/þ ) mice injected with either UHMWPE or saline alone were included in this study. Pouch tissues were collected 14 days after UHMWPE inoculation for molecular and histology analysis. Results showed that UHMWPE stimulation induced strong pouch tissue inflammation in RANK À/À mice, as manifested by inflammatory cellular infiltration, pouch tissue proliferation, and increased gene expression of IL-1b, TNFa, and RANKL. However, the UHMWPE-induced inflammation in RANK À/À mice was not associated with the osteoclastic bone resorption observed in RANK þ/þ mice. In RANK þ/þ mice subjected to UHMWPE stimulation, a large number of TRAP þ cells were found on the implanted bone surface, where active osteoclastic bone resorption was observed. No TRAP þ cells were found in UHMWPE-containing pouch tissues of RANK À/À mice. Consistent with the lack of osteoclastic activity shown by TRAP staining, no significant UHMWPE particle-induced bone resorption was found in RANK À/À mice. A well preserved bone collagen content (Van Gieson staining) and normal plateau surface contour [microcomputed tomography (mCT)] of implanted bone was observed in RANK À/À mice subjected to UHMWPE stimulation. In conclusion, this study provides the evidence that UHMWPE particles induce strong inflammatory responses, but not associated with osteoclastic bone resorption in RANK À/À mice. This indicates that RANK signaling is essential for UHMWPE particle-induced osteoclastic bone resorption, but does not participate in UHMWPE particle-induced inflammatory response. ß