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Distinct Gene Expression of Receptor Activator of Nuclear Factor-Κ B and Rank Ligand in the Inflammatory Response to Variant Morphologies of UHMWPE Particles



W Ren, S Y. Yang, H. W. Fang, Stephen M. Hsu, P H. Wooley


Orthopedic wear debris has been thought to be an important factor associated with aseptic loosening. Our previous studies showed that variant shapes of UHMWPE particles induced diverse cellular and apoptotic responses. This continuing study investigated the gene expression of RANK and RANKL in response to variant shapes of UHMWPE particles in a mouse model of inflammation. Two shapes of UHMWPE particles (globular or elongated) were implanted in the established air pouches on the back of BALB/c mice. Pouches were harvested 7 days after UHMWPE inoculation. Gene levels of RANK, RANKL, TNFa, IL-1b, and cathepsin K were quantified by real time RT-PCR assays. TRAP staining was used to determine osteoclastogenesis. Our data showed that (i) elongated particles generated much higher RANK and RANKL gene expression than globular particles in pouch tissue (p<0.05); (ii) elongated particles provoked a much higher gene levels of both IL-1b and TNFa (p<0.05); (iii) a positive association was found between the gene expression of RANK/RANKL and tissue inflammation status, as well as IL-1b and TNFa gene levels (p<0.01); (iv) elongated particles stimulated higher cathepsin K gene expression in comparison with globular particles (p<0.05). Clusters of TRAP+ cells were observed in pouches located in regions in contact with elongated particles. Our data suggested that the morphology of wear debris might be one of the critical factors in the pathogenesis of aseptic loosening.
No. 26


particles, RANK, RANKL, shape, UHMWPE, wear debris


Ren, W. , Yang, S. , Fang, H. , Hsu, S. and Wooley, P. (2003), Distinct Gene Expression of Receptor Activator of Nuclear Factor-&#922; B and Rank Ligand in the Inflammatory Response to Variant Morphologies of UHMWPE Particles, Biomaterials (Accessed March 1, 2024)
Created October 31, 2003, Updated October 12, 2021