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Fig. 4 Sirt3-deficient mice are more susceptible to viral infection. (A) Disruption of Sirt3 in mice increased MAVS acetylation in mouse spleen upon VSV infection. Proteins extracted from spleens of Sirt3−/− and Sirt3+/+ littermates injected intraperitoneally with VSV [3 × 107 plaque-forming units (PFU) per mouse] for 24 h (n = 5 per group) were analyzed with the indicated antibodies. MAVS acetylation was detected by anti-Ac-K7-MAVS antibody and the relative acetylation level was quantified. (B) Disruption of Sirt3 in mice increased MAVS acetylation in mouse liver after VSV infection. Proteins extracted from livers of Sirt3−/− and Sirt3+/+ littermates injected intraperitoneally with VSV [3 × 107 PFU per mouse] for 24 h (n = 5 per group) were analyzed with the indicated antibodies. MAVS acetylation was detected by anti-Ac-K7-MAVS antibody and the relative acetylation level was quantified. (C–H) qPCR analysis of Ifnβ (C), Ifnα1 (D), Ifnα4 (E), Cxcl10 (F), Cxcl11 (G), and Ifit1 (H) mRNA in the spleens of Sirt3−/− and Sirt3+/+ mice injected intraperitoneally with VSV (3 × 107 PFU per mouse) or PBS control for 24 h. (I–N) qPCR analysis of Ifnβ (I), Ifnα1 (J), Isg15 (K), Cxcl10 (L), Rig-I (M), and Ifit1 (N) mRNA in the lungs of Sirt3−/− and Sirt3+/+ mice injected intraperitoneally with VSV (3 × 107 PFU per mouse) or PBS control for 24 h. (O–T) qPCR analysis of Ifnβ (O), Ifnα1 (P), Isg15 (Q), Cxcl10 (R), Rig-I (S), and Ifit1 (T) mRNA in the livers of Sirt3−/− and Sirt3+/+ mice injected intraperitoneally with VSV (3 × 107 PFU per mouse) or PBS control for 24 h. (U) Survival (Kaplan–Meier curve) of Sirt3−/− and Sirt3+/+ mice (n = 8) injected intraperitoneally with a high dose of VSV (3 × 107 PFU per mouse) and monitored for 10 d. *P < 0.05, using the log-rank test (Mantel-Cox). (V) ELISA of Ifnβ in serum from the Sirt3−/− (n = 5) and Sirt3+/+ mice (n = 5) injected intraperitoneally with VSV (3 × 107 PFU per mouse) or PBS control for 24 h. (W) Hematoxylin-and-eosin-stained (H&E) images of lung sections from mice in (V). (Scale bar, 50 μm.) (X) Schematic of the working model for two RNA viruses, VSV and EMCV. (Y and Z) qPCR analysis of Ifnβ (Y) and Cxcl10 (Z) mRNA in the spleens of Sirt3−/− and Sirt3+/+ mice injected intraperitoneally with EMCV (1 × 106 PFU per mouse) or PBS control for 24 h. ns, not significant (P > 0.05), *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Data from at least three independent experiments (mean ± SD) (A–T, V, Y, and Z).