Fig. 2

UTMD-induced autophagosome accumulation in IR-exposed glioblastoma cells. a, b GL261 and U251 cells were treated with UTMD-L (ultrasonic intensity of 1.2 W/cm² combined with 100 μl/ml MBs) or UTMD-H (ultrasonic intensity of 1.2 W/cm² combined with 200 μl/ml MBs) at a duty cycle of 10% for 60 s. Then, the cells were exposed to IR (2 Gy), and 24 h later, the level of LC3B2 was detected by Western blotting analysis and the indicated protein was quantified. c GL261 cells were transfected with a plasmid expressing GFP-LC3B. After 24 h, the cells were pretreated with UTMD (ultrasonic intensity of 1.2 W/cm² combined with 200 μl/ml MBs at a duty cycle of 10% for 60 s). Then, the cells were exposed to IR (2 Gy) and incubated for an additional 24 h. Following fixation, the cells were immediately visualized by confocal microscopy, and the number of GFP-LC3B dots in each cell was counted. d GL261 cells were pretreated with UTMD (ultrasonic intensity of 1.2 W/cm² combined with 200 μl/ml MBs at a duty cycle of 10% for 60 s). Then, the cells were exposed to IR (2 Gy) and incubated for another 24 h. Autophagosomes were detected by transmission electron microscopy. Arrows indicate the autophagosomes. Values are expressed as the mean ± SD (n = 3). *P < 0.05 vs. the vehicle-treated control group; ^#P < 0.05, ^##P < 0.01 vs. IR group. IR ionizing radiation, UTMD ultrasound-triggered microbubble destruction, LC3B light chain 3 beta, ACTB β-actin, GFP green fluorescent protein, MBs microbubbles, SD standard deviation, a.u. arbitrary units