Fig. 2From: Trichomonas vaginalis induces apoptosis via ROS and ER stress response through ER–mitochondria crosstalk in SiHa cellsTrichomonas vaginalis induced mitochondrial apoptosis in SiHa cells. SiHa cells were infected with live T. vaginalis trophozoites at MOI 2 and 5 for 0, 2 or 6 h. a PARP and caspase-3 proteins were assessed using western blotting analysis, and anti-β-actin was used as a loading control. Lanes: Tv only, T. vaginalis parasite protein without SiHa cells; M, protein marker; CTL, untreated control SiHa cells; Tv, SiHa cells infected with live T. vaginalis. b Ratio of apoptosis was measured and analyzed by Annexin V-FITC/PI staining and flow cytometry. Cells that are considered to be viable are both FITC Annexin V and propidium iodide (PI) negative; cells that are necrotic cells are FITC Annexin V negative and PI positive; cells that are in early apoptosis are FITC Annexin V positive and PI negative; and cells that are in late apoptosis or already dead are are both FITC Annexin V and PI positive. Data are presented as the means ± SD, and asterisks indicate significant difference (***P < 0.001) compared to the control group. c SiHa cells were pretreated with various concentrations of an ROS scavenger (NAC) for 2 h, and subsequently infected with T. vaginalis at MOI 5 for 6 h. PARP and cleaved caspase 3 protein levels were assessed by western blotting. d JC-1 staining was observed by confocal fluorescence microscopy. In JC-1-stained cells, red fluorescence is visible in cells with high mitochondrial membrane potential, while green fluorescence of JC-1 monomer is present in cells with low mitochondrial potential. e SiHa cells were pretreated with various concentration of NAC for 2 h and subsequently infected with T. vaginalis at MOI 5 for 6 h. JC-1 staining was observed using confocal fluorescence microscopy. Scale bars: 10 µm. Data shown are representative of three independent experiments with similar results Back to article page