Abstract:This study is aimed to determine whether autophagy occurred aftor SDT, and to investigate its relationship with apoptosis. S180 cells were examined after SDT induction with ultrasound at a frequency of 1.1MHz and a power of 3W with the presence of 1 μg/ml protoporphyrin Ⅸ. MTT assay was used to evaluated cell viability, DAPI staining was employed to examine the nuclear damage during apoptosis, the fluorescent dye rhodamine 123 was used to detect the mitochondrial membrane potential(MMP), western blot was applied to assess the processing of LC3Ⅰto LC3Ⅱ and acriding orange staining was used to identify the formation of acidic vesicle organelles (AVOs). Following SDT treatment, the cell viability was 593% and the apoptotic features such as chromatin condensation and MMP loss (MFI=971.28) were prominent, autophagy was indentified by the increased LC3II expression. The relationship between autophagy and apoptosis was studied by applying pharmacological inhibition of autophagy or apoptosis. Data indicated that autophagy (1 h) occurred earlier than apoptosis (8 h). The autophagy inhibitors either 3methyladenine(3MA)or bafilomycin A1(Ba A1)led to increased dissipation of mitochondrial membrane potential. DAPI staining further confirmed that autophagy inhibitors enhanced SDT induced cell apoptosis. This article illustrated autophagy participated in SDT caused S180 cell death, and autophagy special inhibitors promoted cellular apoptotic response to SDT.
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