Four-octyl itaconate improves osteoarthritis by enhancing autophagy in chondrocytes via PI3K/AKT/mTOR signalling pathway inhibition.

Osteoarthritis (OA) is a highly prevalent and chronic disorder that is associated with a substantial social and economic burden. Itaconate, as an important regulator of cellular inflammation, is a metabolite synthesised by an enzyme encoded by immune-responsive gene 1. However, there are few studys regarding the effects of itaconate on OA. Here, we show the effect of the cell-permeable itaconate derivative 4-octyl itaconate (OI) on OA. OI attenuates the chondrocyte apoptosis induced by interleukin 1β (IL-1β) in vitro, indicating that OI protect chondrocytes against apoptosis. Moreover, OI ameliorates the chondrocyte autophagy inhibition induced by IL-1β via the inhibition of PI3K/AKT/mTOR signalling pathway. Finally, OI enhances autophagy and reduces cartilage degradation in a rat model of OA established by destabilization of medial meniscus (DMM). In summary, our findings reveal that OI is involved in regulating the progression of OA. The above results shed light on the treatment of OA.