Fig. 1.

Proinflammatory cytokines regulate transglutaminase 2 (TG2) expression in human cell lines. Expression of TG2 was determined by quantitative real time polymerase chain reaction (RT–PCR) in five different human cell lines: intestinal epithelial cell lines Caco-2 and HT29, lung epithelial cell lines A549 and Calu-6 and the monocytic cell line human acute monocytic leukaemia cell line (THP-1) (lower panel of the chart) stimulated for 24 h with proinflammatory cytokines: tumour necrosis factor (TNF)-α (10 ng/ml), interferon (IFN)-γ (200 UI/ml), interleukin (IL)-1 (10 ng/ml), IL-6 (10 ng/ml) and IL-15 (20 ng/ml). Results were normalized against β-actin and relative TG2 mRNA levels were referred to the non-stimulated control (value = 1). Data represent means ± standard error of the mean (n = 3). The Mann–Whitney U-test was performed: *P < 0·05; **P < 0·01.