Fig. 6: OMV-induced mitophagy reduces generation of mitochondrial ROS to enhance intracellular survival.
From: Gonococcal OMV-delivered PorB induces epithelial cell mitophagy
a Live-cell microscopy showing that OMVs transiently induce generation of mitochondrial ROS in HeLa cells. Scale bar, 5 μm. Data are mean ± s.d.; n = 50 cells, two-way ANOVA with posthoc Bonferroni test, P < 10−15 for all reported values. b Live-cell microscopy showing that inhibition of mitophagy with Mdivi-1 prolongs mitochondrial generation of ROS in OMV-stimulated HeLa cells. Data are mean ± s.d.; n = 50 cells, two-way ANOVA with posthoc Bonferroni test, Vehicle-Mdivi-1: P < 10−15 for 3 and 6 h. c Inhibition of mitophagy with Mdivi-1 reduces gonococcal intracellular survival in gentamicin protection assays, while activation of mitophagy with CCCP or scavenging of mitochondrial ROS with mito-TEMPO enhances intracellular survival. Data are mean ± s.d.; n = 4, two-way ANOVA with posthoc Bonferroni test, Vehicle-mito-TEMPO at 3 h: P = 4 × 10−11, Vehicle-CCCP at 6 h: P = 1 × 10−14, Vehicle-mito-TEMPO at 6 h: P < 10−15. d Prior stimulation of HeLa cells with gonococcal WT OMVs to induce mitophagy enhances gonococcal intracellular survival in gentamicin protection assays, while OMVs from gonococcal mutants expressing PorB from N. mucosa or PorB K117Q/K171Q are unable to enhance intracellular survival. Data are mean ± s.d.; n = 4, two-way ANOVA with posthoc Bonferroni test. e Prior stimulation of Mdivi-1-pretreated HeLa cells with gonococcal OMVs reduces gonococcal intracellular survival in gentamicin protection assays. Data are mean ± s.d.; n = 4, two-way ANOVA with posthoc Bonferroni test, OMVs-OMVs+Mdivi-1 at 2 h: P = 9 × 10−11, Vehicle-OMVs+Mdivi1 at 4 h: P = 2 × 10−7, OMVs-OMVs+Mdivi-1 at 4 h: P < 10−15. f Live-cell microscopy of gonococcal-challenged HeLa cells showing reduced generation of mitochondrial ROS for the ΔvacJ mutant and enhanced generation of mitochondrial ROS for N. gonorrhoeae expressing PorB from N. mucosa or PorB K117Q/K171Q. Data are mean ± s.d.; n = 50 cells, two-way ANOVA with posthoc Bonferroni test, WT- ΔvacJ at cell associated: P < 10−15, WT-ΔvacJ at 3 h: P = 1 × 10−13, WT-N.m. PorB at 3 h: P < 10−15, WT-PorB K117Q/K171Q at 3 h: P < 10−15, WT-N.m. PorB at 6 h: P = 4 × 10−12, WT-PorB K117Q/K171Q at 6 h: P = 6 × 10−14. g Gonococcal mutants expressing PorB from N. mucosa or PorB K117Q/K171Q show reduced intracellular survival in gentamicin protection assays. Data are mean ± s.d.; n = 4, two-way ANOVA with posthoc Bonferroni test. Cells in a, b, f are from 3 independent experiments. Data in c–e, g are log-normalized CFU per well from 4 independent experiments, with fold-changes in survival compared with the Vehicle or Mock provided within the bars. Source data are provided as a Source Data file.
