Figure 6: Pharmacological inhibition of the PKM2 pathway protects septic mice.

(a,b) p-EIF2AK2, EIF2AK2 and caspase-1 activity were assayed in isolated PMs from mice during endotoxemia or polymicrobial sepsis in the absence or presence of shikonin (8 mg kg⁻¹) or C16 (50 μg kg⁻¹). In addition, the protein levels of p-EIF2AK2 and EIF2AK2 were assayed in PMs from mice with vehicle (no LPS) injection or sham operated for CLP. (c) Mice (n=20 mice per group) were injected with a single dose of C16 (8 mg kg⁻¹), followed 30 min later by an infusion of endotoxin (LPS, 5 mg kg⁻¹, intraperitoneally), and were then re-treated with C16 12 and 24 h later. The Kaplan–Meyer method was used to compare differences in survival rates between groups (*P<0.05). (d,e) In parallel experiments, serum levels of IL-1β and HMGB1 at indicated time points were measured (n=3 animals per group, *P<0.05, t test). (f) CLP was used to induce intraabdominal sepsis in mice (n=20 group per group). Repeated administration of C16 (50 μg kg⁻¹) at 24, 48 and 72 h after CLP significantly increased survival compared with vehicle group (*P<0.05), as measured by Kaplan–Meyer test. (g,h) In parallel, the serum levels of IL-1β and HMGB1 at indicated time points were measured using ELISA (n=3 animals per group, *P<0.05, t-test). All quantification data expressed as means±s.e.m of three independent experiments. Western blot data are representative of two animals per group.