MMP9 and osteoarthritis: However, Bougault et al. [22] suggested that cartilage degeneration does not depend on NLRP3 inflammasome according to the following evidences: (i) osteoarthritis cartilage was not able to produce active IL-1β; (ii) LPS, IL-1α, and TNFα dose-dependently increased MMP-3, MMP-9, and MMP-13 activity in cultured chondrocytes and in NLRP3(−/−) chondrocytes; (iii) these effects of LPS, IL-1α, and TNFα did not change by inhibition of caspase-1 or IL-1β.