Notice of RetractionApoptosis Induced by Actinomycin D in Spodoptera litura Cells and the Effect of Two Insect Hemolymph on Apoptosis
Actinomycin D induced apoptosis in cells of the Lepidopteran Spodoptera litura cell. By 24h after a actinomycin D treatment, the observation of the microscope and DAPI staining revealed that the cells showed classical morphological characteristics of apoptosis such as plasma bleeding, nuclear fragmentation, and apoptotic bodies. An oligomeric DNA ladder was observed in SL-1 cells treated with 200ng/mL or higher concentration of actinomycin D. Flow cytometric analysis revealed apoptotic behavior of 10.4%, 15.6%, 36.4% and 74.8% in cells treated with 50ng/mL, 100ng/mL,200ng/mL and 500ng/mL actinomycin D by 24 hr after treatment. With the increase of actinomycin D concentration, the rates of cells undergoing apoptosis gradually increased in a concentration-dependent manner. Apoptosis induced by actinomycin D in SL-1 cells was significantly inhibited when cells were cultured in medium containing either Spodoptera exigua hemolymph or Helicoverpa armigera hemolymph. Effect of apoptosis-inhibition enhanced with the increase of hemolymph concentration. Flow cytometric analysis showed that the percentages of apoptosis were 32.9 ± 0.5% 15.7 ± 0.7% and 8.9 ± 0.4% respectively when cells grown in medium containing 1% 3% and 5% Spodoptera exigua hemolymph and the percentages of apoptosis were 36.9 ± 0.5% 20.3 ± 0.7% and 17.0±1.0% when the cells grown in medium containing 1 %, 3% and 5% Helicoverpa armigera hemolymph, respectively. The activity of caspase-3-like in cells cultured in medium containing insect hemolymph markedly decreased. The inhibitory effect of Spodoptera exigua hemolymph on apoptosis was stronger than that of Helicoverpa armigera hemolymph.