Fig. 7
Renal injury and ferroptosis aggravated by CARD9 ablation are caused by OXPHOS during disseminated C. tropicalis infection. To create disseminated candidiasis, Card9−/− and WT mice were intravenously infected with C. tropicalis (2×105 CFU per mouse). In the meantime, WT mice were intraperitoneally injected with PBS (Vehicle) or α-KG (500 mg/kg) per day. And Card9−/− mice were treated with PBS (Vehicle) or metformin (200 mg/kg) by oral gavage daily. (A) The mice were monitored daily for survival postinfection (n = 8). (B-H) Mice were euthanized at day 5 (n = 6). Representative photographs of kidney slices stained with hematoxylin and eosin (H&E) and Periodic Acid-Schiff (PAS). Scale bar: 50 µM. And the inflammatory score and fungal burden was also calculated (B). The proportion of MDSCs (CD11b+Gr1+) in kidney, spleen and bone marrow (BM) were determined by flow cytometry (C and D). The levels of serum TREM1, NGAL, BUN and sCr were measured by the corresponding assay kit (E). The protein level of 4HNE in infected kidneys was detected by immunofluorescence. 4HNE shown in red. DAPI (blue) was used to stain the nuclei. Scale bar: 50 µM (F). The relative renal MDA level was measured by MDA Assay Kit (G). The cell death in infected kidneys was determined by TUNEL staining. TUNEL staining shown in green. DAPI (blue) was used to stain the nuclei. Scale bar: 50 µM (H). Data with error bars are expressed as mean ± SEM. Each panel shows at least six independent biological replicates from a typical experiment. Statistical analysis was determined by the log-rank (Mantel-Cox) test (A) and one-way ANOVA with Bonferroni’s multiple comparisons test for post-hoc test (B-G). ns (not significant), P > 0.05; *P < 0.05, **P < 0.01, ***P < 0.001