Temporomandibular joint
osteoarthritis (TMJ-OA) is a common disease with a high level of
inflammation in the joint micro-environment and cartilage degradation. Anti-
inflammation and cartilage regeneration are the key
therapies for TMJ-OA, but currently, there are no novel medicines or treatments that can control its pathogenic progression.
Strontium ranelate (SrR) is an anti-
osteoporosis drug and is now considered a promising anti-OA drug, but the anti-inflammatory effect of SrR remains to be elucidated. In the present study, the anti-inflammatory effect of SrR in a normal or high IL-1β environment was observed. Cell viability under the treatment of SrR was tested using Cell Counting Kit-8.
Toluidine blue staining, immunofluorescence staining,
hydroxyproline assay, PCR assay and western blotting were used to detect the expression of
collagen (Col)II,
proteoglycans (PG) and
aggrecan as a reflection of extracellular matrix synthesis and MMP-9,13
hydroxyproline was used as an
inflammation indicator. IL-1β of 10 ng/ml was added to the culture medium as
inflammation environment and the tests of those
biomarkers were done again. Then, the changes in β-
catenin were also studied by immunofluorescence staining, PCR assay and western blotting to explore the possible involvement of the Wnt/β-
catenin pathway. The results showed a significant inhibition of MMP-9, MMP-13, β-
catenin and promotion of Col-II, PG and
aggrecan in normal chondrocytes. The presence of IL-1β markedly upregulated the expression of MMP-9, MMP-13 and β-
catenin while suppressing Col-II and PG and SrR partially reversed this trend. In conclusion, SrR decreased
MMPs but promoted Col-II,
aggrecan and PG synthesis in rat chondrocytes with or without the presence of IL-1β and SrR attenuated the IL-1β-induced increase in β-
catenin, thus reducing the inflammatory reaction.