Dose-dependent effects of lanthanum chloride on wear particle-induced aseptic inflammation in a murine air-pouch model

To investigate the effects of local injection of different doses of lanthanum chloride (LaCl3) on aseptic inflammation in mice stimulated by wear particles from artificial joints, the particles were prepared by vacuum ball mill in vitro and air-pouch models were performed with 45 male BALB/c mice that were randomly divided into blank control group, wear particle group and wear particle + LaCl3 (0.1, 0.9 and 8.1 μmol) group. All animals were sacrificed and tissue specimens were harvested 7 days after treatment. Hematoxylin and eosin (H&E) staining, enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR) and western blot were applied to observe inflammatory reaction and detect the expression of pro-inflammatory cytokines (TNF-α, IL-1β) and nuclear factor-κB (NF-κB) in mRNA and protein levels in air-pouch membrances. The results showed that wear particles could stimulate aseptic inflammation in vivo effectively; 0.9 μmol LaCl3 could significantly inhibit wear particle-induced gene and protein expression of pro-inflammatory cytokines and NF-κB (P>0.05); 0.1 and 8.1 μmol LaCl3 did not exert an inflammation-inhibiting effect and even caused adverse effects at 8.1 μmol. In conclusion, LaCl3 played a protective role against wear particle-induced aseptic inflammation dose-dependently, which was involved in NF-κB related signaling pathways.