Figure 7: CIRP-induced ER stress is TLR4-dependent.

Lung levels of (A) BiP, (B) pIRE1α, and (C) sXBP1 proteins were significantly elevated in healthy WT mice treated with rmCIRP (*P < 0.05), confirming that CIRP induces ER stress. Lung levels of (D) BiP, (E) pIRE1α, and (F) sXBP1 proteins, however, were not increased in healthy TLR4 KO mice treated with rmCIRP (NS, not significant), indicating that ER stress induction by CIRP requires TLR4. Western blotting of homogenates from lungs collected 20 h after rmCIRP intravenous administration. The dotted lines on the WB reflect the groups shown in the histogram below. Data are expressed as mean ± SEM. Sample sizes: WT, vehicle = 3, rmCIRP = 5; TLR4 KO, vehicle = 2, rmCIRP = 2.