Figure 4.

Distinct effects of myosin IIA or IIB knockdown on H₂O₂-induced morphological changes and apoptosis in PC12 cells. PC12 cells were transfected with siRNAs against myosin IIA (#1 siMyh9), myosin IIB (#1 siMyh10), or NC sequence as described in experimental procedures. (A) Representative phase-contrast micrographs of transfected PC12 cells treated or untreated with H₂O₂. Bar, 10 μm. (B) PC12 cells with membrane blebs were counted and the percentage of these cells with respect to the total cell population was calculated. Body area (C) and neurite length (D) was measured using the ImageJ software. The results were represented as percentage of control. (E) Viability of transfected cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. (F) The number of PC12 cells transfected with siRNAs targeting at myosin IIA or IIB was counted in the bright-field images. (G) Decreased cell viability was calculated by subtracting viability of H₂O₂-treated cells from control cells. (H) Caspase-3 activity was measured by caspase-3 activity assay kit. Values were represented as mean ± SD from three independent experiments (^#P < 0.05, ^##P < 0.01).