Figure 5. MEG3 knockdown induces autophagy.

(a) Knockdown in THP-1 using a specific siRNA resulted in significantly (unpaired t test, P < 0.0001) decreased cellular MEG3 levels compared with nonsense-transfected control(n c). Experiments were repeated at least 3 times. (b) MEG3 knockdown resulted in significantly (unpaired t test, P < 0.001) increased LC3A/B punctae compared with nonsense transfected controls (n c). Box plots show at least three biological replicates. (c) MEG3 knockdown had no effect on LC3B transcriptional levels. (d) MEG3 knockdown triggered autophagy as demonstrated by increased LC3A/B conversion in both infected and non infected macrophages. mTOR activation was determined by evaluating p70-S6K phosphorylation. GAPDH is shown first as respective loading reference. (e) After knockdown LC3A/B punctae were co-localised with intracellular BCG d) MEG3 knockdown significantly decreased intracellular BCG numbers as determined by quantification of fluorescence signals as well as CFU (unpaired t test, P < 0.05).