Amigo2 expression levels correlate with cell death. Healthy, OA and RA synoviocytes were preexposed to a combination of IL-17A and TNF-α overnight before addition of a low dose of the proapoptotic agent Cd (A,B,D). Amigo2 expression was then evaluated 6 h after Cd addition by quantitative real-time PCR and is expressed as fold changes compared to healthy synoviocytes exposed to vehicle (A). Cell death was determined by cell cycle analysis after a week (B). To evaluate the effect of HMGB1 on cell death, RA synoviocytes were preexposed to a combination of IL-17A and TNF-α in the presence or not of HMGB1 followed by Cd addition. Cell death was quantified by cell cycle analysis after a week and is represented as fold changes compared to cells treated with Cd and cytokines (C). Similarly to Amigo2, Bcl2 expression was evaluated by quantitative real-time PCR and is expressed as fold changes compared to healthy synoviocytes exposed to vehicle (D). Data are the mean of at least three independent experiments ± SEM. Cyt, cytokines; H, HMGB1. #Comparison with control situation, *comparison with cytokine treated cells, §comparison between cell types. *,#P ≤ 0.05, **,§§P ≤ 0.01, ***,###,§§§P ≤ 0.001.