Fig. 4.

Inhibition of the ROS/ERK pathway is responsible for autophagy-mediated apoptosis of MSCs. a shNC-MSCs (shNC) and shBec1-MSCs (shBecn1) stimulated with tumor necrosis factor alpha (TNF-α; 20 ng/ml) plus interferon gamma (IFN-γ; 50 ng/ml) or combined with PD98059 or N-acetyl cysteine (NAC) before stimulation with TNF-α for 24 hours. b Naive MSCs were treated with 3-methyladenine (3-Ma; 10 mM) for 12 hours, then stimulated with TNF-α (50 ng/ml) plus IFN-γ (50 ng/ml) or combined with PD98059 or NAC before TNF-α stimulation for 24 hours. Cells were stained with annexin V/prodium iodide (PI) for apoptosis assay. Representative graphs from three independent experiments are shown