Fig 2: Irisin inhibits caspase-1-mediated pyroptosis by regulating the HSP90/NLRP3 signaling pathway. The grouping of mice and cells is the same as in Fig. 5. (A and B) After drug treatment, proteins were extracted from (A) lung tissue and (B) MH-S cells and subjected to western blotting to determine the expression levels of NLRP3, HSP90, GSDMD, caspase-1, cleaved caspase-1 and IL-1ß proteins. (C-N) Relative quantitative analysis of protein expression. The data are expressed as the mean ± SD.*P<0.05 vs. Con group; #P<0.05 vs. LPS group; &P<0.05 vs. LPS + IR group; ns, not significant vs. LPS + IR group. LPS, lipopolysaccharide; Con, control; NLRP3, nucleotide-binding and oligomerization domain-like receptor protein 3; HSP90, heat shock protein 90; GSDMD, gasdermin D; IL, interleukin; M, MCC950; IR, irisin; 17, 17-AAG (17-N-allylamino-17-demethoxygeldanamycin).

Fig 3: RT-qPCR analysis of (A and E) NLRP3, (B and F) HSP90, (C and G) GSDMD, and (D and H) Caspase-1 mRNA expression in vivo (n=6, A-D) and in vivo (n=3, E-H). The data are expressed as the mean ± SD.*P<0.05 vs. Con group; #P<0.05 vs. LPS group; &P<0.05 vs. LPS + IR group; ns, not significant vs. LPS + IR group. LPS, lipopolysaccharide; Con, control; M, MCC950; IR, irisin; 17, 17-AAG (17-N-allylamino-17-demethoxygeldanamycin); GSDMD, gasdermin D; NLRP3, nucleotide-binding and oligomerization domain-like receptor protein 3; HSP90, heat shock protein 90.

Fig 4: Irisin attenuates the LPS-induced inflammatory response. Mice were randomly assigned to the control, LPS (2 mg/kg), LPS + IR (LPS 2 mg/kg, irisin 0.5 mg/kg), and LPS + MCC950 (LPS 2 mg/kg, MCC950 50 mg/kg) groups (n=6). MH-S cells (n=3) were co-treated with IR (200 ng/ml) or 17-AAG (100 ng/ml) and LPS (10 µg/ml) for 4 h. Western blotting was used to measure NLRP3 and HSP90 protein expression. (A) Total number of cells, (B) proteins, and (C) neutrophils in the specimens of BALF. (D-I) Irisin inhibited the activation of the NLRP3 inflammasome and the expression of HSP90 in mice and MH-S cells. The data are expressed as the mean ± SD. *P<0.05 vs. Con group; #P<0.05 vs. LPS group; &P<0.05 vs. LPS + IR group; ns, not significant vs. LPS + IR group. LPS, lipopolysaccharide; BALF, bronchoalveolar lavage fluid; Con, control; NLRP3, nucleotide-binding and oligomerization domain-like receptor protein 3; HSP90, heat shock protein 90; 17-AAG, 17-N-allylamino-17-demethoxygeldanamycin.