Figure 11.

T. gondii pre-infection prevented AgNP-induced mitochondrial apoptosis by suppressing NOX4-dependent ROS generation in HFF cells. (A) HFF cells were treated with various concentrations of AgNPs for 24 h and protein levels of cleaved caspase-3 and PARP were determined by Western blotting. HFF cells were pre-infected with T. gondii at MOI 5 for 2 h and treated with or without 5 μg/mL AgNPs for 24 h. (B) The protein levels of cleaved caspase-3 and PARP were determined by Western blotting. (C) The cells were loaded with MitoSOX red (5 μM for 30 min) and mitochondrial ROS were detected by flow cytometry. (D) NOX4 mRNA levels were determined by qRT-PCR. HPRT1 served as an internal control. HFF cells were transfected with control siRNA or specific NOX4 siRNAs and treated with 5 μg/mL AgNPs for 24 h. (E) Mitochondrial ROS levels were measured by flow cytometry after MitoSOX staining. **P < 0.01, ***, P < 0.001, as compared to the control or AgNPs-treated group. (F) Protein levels of NOX4 and PARP were assessed by Western blot analysis. α-Tubulin was used as an internal loading control. (G) JC-1 stained cells were observed by confocal imaging.

Abbreviations: AgNPs, silver nanoparticles; ROS, reactive oxygen species; HFF, human foreskin fibroblast; NOX4, NADPH oxidase 4; PARP, poly (ADP‐ribose) polymerase; siRNA, small interfering RNA; JC-1, 5.5′,6,6′-Tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide; DAPI, 4ʹ,6-diamidino-2-phenylindole