Fig. 1. Silencing of KDM4B but not KDM4A/KDM4C inhibits the production of IL-8.

a Generation of KDM4A-, KDM4B-, and KDM4C-knockdown AGS cells. Cells were infected with lentivirus using a control shRNA (pLKO) and two independent short-hairpin constructs to generate shKDM4A (sh4A#1 and sh4A#2), shKDM4B (sh4B#1 and sh4B#2), and shKDM4C (sh4C#1 and sh4C#2), respectively. Depletion of KDM4A, KDM4B, or KDM4C was confirmed by western blotting analysis. β-Actin was the internal control. b IL-8 release was measured from the supernatants of non-infected or H. pylori-infected cells by ELISA. Data represent the mean ± standard deviation (SD) from three independent experiments. c Images of cytokine arrays for the detection of the relative levels of cytokines from supernatants of pLKO and sh4B#1 cells, respectively. Cells were non-infected (−Hp) or infected with H. pylori (+ Hp) at an moi of 50 for 6 h. d The relative fold of IL-8, CXCL1, and CCL5 was measured and shown as a ratio of pLKO (−Hp) levels from (c). *p < 0.05; **p < 0.01