Inhibition of the PI3K/AKT Pathway Reduces Tumor Necrosis Factor-Alpha Production in the Cellular Response to Wear Particles In Vitro

• Published in: Artificial organs Vol. 37; no. 3; pp. 298 - 307
• Main Authors: Huang, Jian-bin, Ding, Yue, Huang, Dong-sheng, Liang, An-jing, Zeng, Wei-ke, Zeng, Zhan-peng, Qin, Chu-qiang, Barden, Bertram
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.03.2013; Wiley Subscription Services, Inc
• Subjects: Aluminum Oxide - toxicity; Animals; Aseptic loosening; Atoms & subatomic particles; Blotting, Western; Cell Line; Chromones - pharmacology; Class Ia Phosphatidylinositol 3-Kinase - antagonists & inhibitors; Class Ia Phosphatidylinositol 3-Kinase - metabolism; Cytokines; Down-Regulation; Enzyme Activation; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation, Enzymologic; Inflammation Mediators - metabolism; Joint Prosthesis - adverse effects; Joint replacement; Macrophage; Macrophage Activation - drug effects; Macrophages - drug effects; Macrophages - enzymology; Macrophages - immunology; Mice; Morpholines - pharmacology; Particle Size; Phosphatidylinositol 3-Kinase - antagonists & inhibitors; Phosphatidylinositol 3-Kinase - genetics; Phosphatidylinositol 3-Kinase - metabolism; Phosphatidylinositol 3-Kinases - antagonists & inhibitors; Phosphatidylinositol 3-Kinases - metabolism; Phosphorylation; PI3K/AKT; Prosthesis Design; Prosthesis Failure; Protein Kinase Inhibitors - pharmacology; Proto-Oncogene Proteins c-akt - antagonists & inhibitors; Proto-Oncogene Proteins c-akt - genetics; Proto-Oncogene Proteins c-akt - metabolism; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Time Factors; Titanium - toxicity; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - metabolism
• ISSN: 0160-564X; 1525-1594
• DOI: 10.1111/j.1525-1594.2012.01568.x

Joint replacement is the most effective treatment for end‐stage osteoarticular disease. However, macrophage‐mediated aseptic loosening of joint prosthesis severely hampers the clinical effects of joint replacement. Until now, the mechanism by which macrophages regulate the secretion of inflammatory cytokines after particle stimulation is not clear. It is well known that the PI3K/AKT pathway participates in multiple cellular processes, including cell growth, survival, and inflammation. However, whether the PI3K/AKT pathway participates in the proinflammatory response of macrophages after particle stimulation and secondary aseptic loosening is still unknown. In this study, ceramic and titanium particles of different sizes were prepared to stimulate macrophages. LY294002, a specific inhibitor of PI3K, was pretreated prior to particle stimulation. The expression of tumor necrosis factor‐alpha (TNF‐α) and all the subunits of PI3K and AKT were detected by real‐time polymerase chain reaction, enzyme‐linked immunosorbent assay, and Western blot. The result showed that LY294002 could suppress the RNA and protein expression of TNF‐α in RAW264.7 cells after stimulation of different particles. The subunits of PI3K (p110β and p85β), followed by activation of phosphor‐AKT (Ser473), participated in the regulation of activating macrophages by wear particles, ultimately resulting in the secretion of TNF‐α.